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2022-06-01 | Because of its outstanding strength-to-density ratios, corrosion resistance, and other superior properties, Ti-6Al-2Zr-1Mo-1 V titanium alloy (TA15) is widely employed in aeronautics and astronautics. TA15 is a typical difficult-to-cut material with low heat conductivity, a high cutting temperature, and an easy adhesion characteristic. When machining difficult-to-cut materials, cryogenic machining is an efficient way to lower the cutting temperature. There is, however, few research on machining TA15 under cryogenic cooling conditions. In this study, tensile tests were performed under different low-temperature cooling conditions. By analyzing the changes of material properties under different low temperatures, the machining mechanism of TA15 under cryogenic cooling conditions was revealed. Then, cutting experiments were carried out under three cooling conditions: dry, cutting fluid (wet), and liquid nitrogen internal cooling (cryogenic). The results show that under cryogenic conditions, TA15 can effectively reduce plasticity and adhesion. The cutting experiments also prove that machining TA15 under the cryogenic cooling condition can reduce the surface adhesion, improve the machining quality of the machined surface, and effectively reduce the generation of tool adhesion wear. | Machinability investigations in cryogenic internal cooling turning Ti-6Al-2Zr-1Mo-1 V titanium alloy | 10.1007/s00170-022-09117-z |
2022-06-01 | The recently developed dual-phase (DP) non-equiatomic Fe_50Mn_30Co_10Cr_10 (at.%) high-entropy alloy (HEA) showed much higher strength and ductility compared to the single-phase equiatomic Fe_20Mn_20Ni_20Co_20Cr_20 (at.%) HEA at room temperature. Herein we probe the cryogenic mechanical properties of the non-equiatomic DP-HEA with different grain sizes and compare with the equiatomic single-phase HEA. Our results show that the cryogenic ultimate tensile strengths of the coarse-grained (∼ 200 µm) and fine-grained (∼ 4 µm) DP-HEAs reach up to 1,133 and 1,342 MPa, respectively, which are significantly higher than that of the equiatomic single-phase HEAs with similar grain sizes. Furthermore, the fine-grained DP-HEA shows substantial improvement in both strength and ductility compared to the coarse-grained counterparts at cryogenic temperatures. Microstructural analysis reveals that the enhanced mechanical properties of the DP-HEA at cryogenic temperatures are attributed to a more extensive displacive transformation from the face-centered cubic (FCC) matrix into the hexagonal close-packed (HCP) phase compared to that at room temperature. Specifically, the HCP phase fraction in tensile tested fine-grained DP-HEAs increases from ∼ 39% to ∼ 79% with decreasing temperature from 298 to 77 K. The enhanced transformation behavior is enabled by the reduced stacking fault energy of the material with the decrease of deformation temperatures. The resulting outstanding combination of strength and ductility further suggests that the DP-HEAs are promising candidates as structural materials for cryogenic applications. | Cryogenic mechanical behavior of a TRIP-assisted dual-phase high-entropy alloy | 10.1007/s12274-021-3719-y |
2022-05-14 | Molecular dynamics simulations are performed to investigate the cryogenic nano-cutting of monocrystalline γ-TiAl alloy. Effects of different low-temperature conditions on material properties and surface integrity are systematically investigated, aiming to predict the optimal low-temperature processing conditions of monocrystalline γ-TiAl alloy in the nano-cutting process. The results show that the cohesive energy of monocrystalline γ-TiAl alloy increases at low temperature, but the low temperature is not the necessary condition for forming residual compressive stress on the machined surface. In the stable cutting stage, the heat dissipation rate of the workpiece increases linearly with the increase of the cutting distance, which is consistent with the stability of the Newtonian layer temperature. In addition, the evolution process of the dislocation band in the subsurface damage layer is explained from the atomic perspective. By comparing and analyzing the surface integrity under different cryogenic cutting, the optimal cryogenic cutting temperature is about 173 K. | Effect of cryogenic nano-cutting on surface integrity of the single crystal γ-TiAl alloy via atomic simulation | 10.1007/s00339-022-05640-8 |
2022-05-01 | A novel severe plastic deformation is carried out on a medium Mn advanced high strength steel (AHSS) at both room and cryogenic temperatures which is called surface mechanical impact treatment (SMIT). After characterization, utilizing the design of experiment (DOE) program, it is obtained that how the SMIT parameters including time, voltage, and, shot diameter affect the tensile test results of SMITed samples at room temperature (RT-SMITed). Microhardness profiles of SMITed samples at cryogenic temperature (CT-SMITed) show more increase in microhardness than RT-SMITed ones up to the center of specimens. Additionally, the yield strength of CT-SMITed and RT-SMITed samples increases by 84% and 28% on average, respectively. The formation of mechanical twins, slip bands and, rhombic blocks improve both the microhardness and yield strength of treated samples. The ultimate tensile strength (UTS) of all treated specimens decreases sharply (35% in RT-SMITed and 32% in CT-SMITed samples). According to DOE results, UTS has a negative correlation with voltage and based on fracture surface images, brittle fracture configurations increases with increasing voltage. The reason for this observation could be the precracks formed due to the deformation of detected MnS precipitates and the possibility of the martensite phase cracking during the SMIT process. Graphic Abstract | Effects of a Novel Severe Plastic Deformation Approach on Microstructural and Mechanical Characteristics of a Medium Manganese Advanced High Strength Steel | 10.1007/s12540-021-01007-5 |
2022-05-01 | There is a tremendous increase in the demand for converting biomaterials into high-quality industrially manufactured human body parts, also known as medical implants. Drug delivery systems, bone plates, screws, cranial, and dental devices are the popular examples of these implants - the potential alternatives for human life survival. However, the processing techniques of an engineered implant largely determine its preciseness, surface characteristics, and interactive ability with the adjacent tissue(s) in a particular biological environment. Moreover, the high cost-effective manufacturing of an implant under tight tolerances remains a challenge. In this regard, several subtractive or additive manufacturing techniques are employed to manufacture patient-specific implants, depending primarily on the required biocompatibility, bioactivity, surface integrity, and fatigue strength. The present paper reviews numerous non-degradable and degradable metallic implant biomaterials such as stainless steel (SS), titanium (Ti)-based, cobalt (Co)-based, nickel-titanium (NiTi), and magnesium (Mg)-based alloys, followed by their processing via traditional turning, drilling, and milling including the high-speed multi-axis CNC machining, and non-traditional abrasive water jet machining (AWJM), laser beam machining (LBM), ultrasonic machining (USM), and electric discharge machining (EDM) types of subtractive manufacturing techniques. However, the review further funnels down its primary focus on Mg, NiTi, and Ti-based alloys on the basis of the increasing trend of their implant applications in the last decade due to some of their outstanding properties. In the recent years, the incorporation of cryogenic coolant-assisted traditional subtraction of biomaterials has gained researchers’ attention due to its sustainability, environment-friendly nature, performance, and superior biocompatible and functional outcomes fitting for medical applications. However, some of the latest studies reported that the medical implant manufacturing requirements could be more remarkably met using the non-traditional subtractive manufacturing approaches. Altogether, cryogenic machining among the traditional routes and EDM among the non-traditional means along with their variants, were identified as some of the most effective subtractive manufacturing techniques for achieving the dimensionally accurate and biocompatible metallic medical implants with significantly modified surfaces. | A comprehensive review on metallic implant biomaterials and their subtractive manufacturing | 10.1007/s00170-022-08770-8 |
2022-05-01 | Abstract Based on the analysis of the results of experiments on deuterated fibers, frozen deuterium fibers, and heterogeneous low-density targets, it can be concluded that low-density monodisperse cryogenic targets with a complex microheterogeneous structure are most suitable for the further investigation of emitting Z‑pinches of multiterawatt power. These studies have shown that using the available equipment it is possible to obtain cryogenic targets of hydrogen or its isotopes of the following types: cylindrical “thick” fibers up to 10 cm long and 40 to 300 µm in diameter; “thin” fibers with a length of 5 to 10 cm with a diameter of 30 to 40 µm, and monodisperse cryogenic targets. In general, cryogenic monodisperse targets are a flow of solid monodisperse granules of hydrogen or its isotopes with a diameter of 10 to 100 μm, a velocity of up to 100 m/s, and a frequency of occurrence in the discharge region from 0.01 Hz to 500 kHz. Using outlet nozzles with a large number of outlet holes, it is possible to obtain monodisperse cryogenic targets with a complex microheterogeneous structure, consisting of tens and hundreds of granules. In addition, the flow of granules can be controlled, e.g., by focusing it on the desired spatial point. The relative spread of targets in velocity and size does not exceed 0.1%. The use of cryogenic deuterium targets with a complex microheterogeneous structure makes it possible to increase the deuterium concentration in the target several times compared to other types of targets. A high initial concentration of deuterium and effective ionization of the target material can lead to a significant increase in the neutron yield due to the power-law dependence of the yield on concentration ( Y ~ n ^2). Additional factors that can significantly increase the neutron yield are: the power dependence of the neutron yield on the discharge current and the transition from a deuterium target to a target made from a deuterium–tritium mixture. | Use of Condensed Deuterium and Cryogenic Monodisperse Targets as Loads for Studying Megaampere Z-Pinches | 10.1134/S1063780X22200041 |
2022-05-01 | The magnetocaloric (MC) effect-based solid-state magnetic refrigeration (MR) technology has been recognized as an alternative novel method to the presently commercialized gas compression technology. Searching for suitable candidates with promising MC performances is one of the most urgent tasks. Herein, combined experimental and theoretical investigations on the magnetic properties, magnetic phase transition, and cryogenic MC performances of GdFe_2Si_2 have been performed. An unstable antiferromagnetic (AFM) interaction in the ground state has been confirmed in GdFe_2Si_2. Moreover, a huge reversible cryogenic MC effect and promising MC performances in GdFe_2Si_2 have been observed. The maximum isothermal magnetic entropy change, temperature-averaged entropy change with 2 K lift, and refrigerant capacity for GdFe_2Si_2 were 30.01 J kg^−1 K^−1, 29.37 J kg^−1 K^−1, and 328.45 J kg^−1 at around 8.6 K with the magnetic change of 0–7 T, respectively. Evidently, the values of these MC parameters for the present AFM compound GdFe_2Si_2 are superior to those of most recently reported rare-earth-based MC materials, suggesting the potential application for active cryogenic MR. 基于磁性材料相变过程中伴随的磁热效应而发展起来的磁制冷技术因其绿色环保和高效节能等优点而被广泛关注. 高性能磁制冷工质材料的探索一直是本领域的研究热点也是难点之一. 本文中, 我们通过实验研究结合第一性原理计算, 对GdFe_2Si_2化合物的晶体结构、磁性、磁相变以及低温磁热效应进行了系统研究, 结果表明GdFe_2Si_2化合物基态为反铁磁且具有大的低温可逆磁热效应. 在0–7 T的磁场变化下, 其磁制冷参数包括等温磁熵变最大值和制冷能力分别高达30.01 J kg^−1K^−1和328.45 J kg^−1. 这些磁制冷参数优于大多数目前已报道的同温区高性能稀土基磁制冷材料, 表明反铁磁GdFe_2Si_2化合物在低温磁制冷领域同样具有潜在的应用前景. | Magnetic properties and promising magnetocaloric performances in the antiferromagnetic GdFe_2Si_2 compound | 10.1007/s40843-021-1967-5 |
2022-05-01 | The objective of this research was to investigate the effectiveness of application of liquid nitrogen (LN_2) in turning of Inconel 718 compared to flooded cutting and select suitable LN_2 cutting parameters using response surface methodology (RSM). The results of turning experiments conducted by spraying LN_2 to the cutting area of Inconel 718 bar showed that using either low or high cutting parameters, cutting performance of Inconel 718 under the cryogenic condition was generally worse than the flooded cutting. However, using the medium cutting parameters, the LN_2 cutting performance was as good as that of the flooded cutting both showing a cutting force of 90 N, 60 µm of flank wear and 0.5–0.6 µm of surface roughness ( Ra ). These parameters were further optimized using desirability function of RSM to determine the set of parameters that provided the lowest cutting force, flank wear and Ra values and the highest material removal rate (MRR) under cryogenic cutting. Analysis of variance (ANOVA) performed on the regression models developed showed that cutting speed was the only significant factor on the cutting force. Feed rate was the most influential parameter on the flank wear. Feed rate and depth of cut were significant factors both affecting Ra . Multi-objective optimization showed that a cutting speed of 87 m/min, a feed rate of 0.06 mm/rev and a depth of cut of 0.37 mm constituted the optimum cutting parameters for achieving a cutting force of 78 N, flank wear of 58 µm, Ra of 0.49 µm and the MRR of 1.97 cm^3/min under the cryogenic cutting condition. | Turning of Inconel 718 using liquid nitrogen: multi-objective optimization of cutting parameters using RSM | 10.1007/s00170-022-08906-w |
2022-04-01 | Abstract The cyclic deep cryogenic treatment was proposed to improve both the hardness and corrosion resistance of the high strength 7075 aluminum alloy. The effect of different CDCT times on the exfoliation corrosion and intergranular corrosion of the alloys were observed by scanning electron microscope. The corrosion behaviors of the alloys were monitored by electrochemical techniques. The hardness of the alloy was measured by Vickers hardness tester. Furthermore, the microstructures of the alloys were examined by transmission electron microscope. The results show that the corrosion resistance and hardness are strongly affected by the precipitate state. The discontinuous grain boundary precipitates and the wide precipitate free zones will enhance the corrosion resistance. The fine precipitates distributed evenly in the matrix can increase the hardness. After the CDCT, the corrosion resistance is remarkably improved without sacrificing the hardness. The best combination of the hardness and corrosion resistance is exhibited for the alloy treated with the CDCT twice. Graphic Abstract | Effect of Cyclic Deep Cryogenic Treatment on Corrosion Resistance of 7075 Alloy | 10.1007/s12540-021-00975-y |
2022-04-01 | The ARIEL mission is a space project consisting of a spacecraft with the goal of detecting exoplanets and observing the characteristics of their atmospheres. One of the main sub-systems of the payload is the telescope that must operate under cryogenic conditions to guarantee its adequate performance and the mission success. One of the critical aspects in the development of a space telescope is the stability and the related analyses required to evaluate the degree of deformation of the system under all environmental conditions, with special emphasis on the different and extreme temperature ranges reached during the mission. This assessment involves the close collaboration between three different disciplines: thermal, structural and optical design. This paper describes the work done in the ARIEL project in the field of the structural stability analysis, showing the process to achieve reliable and accurate results. The main novelty of this work is the validation of the structural model to achieve the required level of precision in the displacements fields calculated numerically to provide reliable and accurate deformations that will allow the assessment of the thermoelastic effects on the optical performance of the main telescope. The results of the structural simulations show how the telescope assembly is deformed under the different analysed conditions, which will allow the design of compensation mechanisms to mitigate these effects. | Thermoelastic evaluation of the payload module of the ARIEL mission | 10.1007/s10686-021-09704-0 |
2022-04-01 | The temperature dependences of resistance for the p-type conductivity solid solution silicon–germanium whiskers doped by boron with concentration of 1 × 10^18 cm^−3 were investigated in the temperature range of 4.2–300 K and under the uniaxial compressive strain till − 3 × 10^–3 rel. un. We studied the strain influence, which was caused on a spin–orbit splitting in the valence band spectrum. As an outcome, the spin–orbit splitting energies for both light and heavy holes were discovered based on the k–p method. The strain-induced effects of solid solution Si_0.2Ge_0.8 whiskers were studied at low temperatures. Found giant piezoresistive effect at helium temperature gives opportunity to create the supersensitive strain gages on the basis of silicon–germanium whiskers with doping concentration in the vicinity to the metal–insulator transition. The mechanical sensor operating at helium temperature and deformation range of 5 × 10^–4–1.3 × 10^–3 rel. un. was designed with the sensitive element Si_0.2Ge_0.8 whiskers doped to concentration 1 × 10^18 cm^−3. | Strain-induced splitting in valence band of Si–Ge whiskers | 10.1007/s13204-021-01747-1 |
2022-04-01 | ARIEL, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was selected as the fourth medium-class mission in ESA’s Cosmic Vision program. ARIEL is based on a 1 m class telescope optimized for spectroscopy in the waveband between 1.95 and 7.8 micron and operating in cryogenic conditions. Fabrication of the 1.1 m aluminum primary mirror for the ARIEL telescope requires technological advances in the three areas of substrate thermal stabilization, optical surface polishing and coating. This article describes the qualification of the three procedures that have been set up and tested to demonstrate the readiness level of the technological processes employed. Substrate thermal stabilization is required to avoid deformations of the optical surface during cool down of the telescope to the operating temperature below 50 K. Purpose of the process is to release internal stress in the substrate that can cause such shape deformations. Polishing of large aluminum surfaces to optical quality is notoriously difficult due to softness of the material, and required setup and test of a specific polishing recipe capable of reducing residual surface shape errors while maintaining surface roughness below 10 nm RMS. Finally, optical coating with protected silver must be qualified for environmental stability, particularly at cryogenic temperatures, and uniformity. All processes described in this article have been applied to aluminum samples of up to 150 mm of diameter, leading the way to the planned final test on a full size demonstrator of the ARIEL primary mirror. | Qualification of the thermal stabilization, polishing and coating procedures for the aluminum telescope mirrors of the ARIEL mission | 10.1007/s10686-022-09852-x |
2022-04-01 | The redistribution of C and N atoms during cryogenic treatment is crucial for the microstructure evolution and properties of high nitrogen martensitic steel. Here, the distinct redistribution behavior of C and N atoms in a martensitic stainless steel with 0.3 wt% C and 0.5 wt% N after cryogenic treatment were investigated by the atom probe tomography. Carbon clusters begin to form after cryogenic treatment at − 60 °C and gradually increase with the decrease of cryogenic treatment temperature. While Mo–N and Cr–N pairs are homogeneously distributed in the matrix even after cryogenic treatment at −120 °C, and then form enrichment phenomenon when the cryogenic temperature is deeply lowered to − 190 °C. It is found that the distinct redistributions of C and N atoms are associated with the different interaction energy between substitutional atoms and them. The stronger interaction between Cr, Mo atoms and N delays the segregation of N during the cryogenic treatment. Finally, the mechanical properties results confirmed that the deep lower cryogenic treatment is a promising method to improve the hardness and strength in the high nitrogen martensitic stainless steel. | Redistribution of C and N Atoms in High Nitrogen Martensitic Stainless Steel During Cryogenic Treatment | 10.1007/s40195-021-01265-7 |
2022-03-04 | In the present work, the structure, magnetic properties, and cryogenic magnetocaloric effect of weberite-type oxides Gd_3MO_7 (M = Nb, Sb, and Ta) are reported through powder X-ray diffraction, bulk susceptibility, and heat capacity measurements, as well as scaling law analysis and a mean-field approach. A remarkably large isothermal magnetic entropy change of 354.0 mJ K^−1 cm^−3 is observed for Gd_3SbO_7 under an external field of 9 T at 2.0 K. The relative cooling power is estimated to be 618.9 J kg^−1 (4.8 J cm^−3) for an applied field of 8.9 T, with the largest adiabatic temperature change being 22.4 K at 6.3 K. The magnetocaloric performance of these oxides is quite impressive when compared with the benchmark magnetic refrigerant, gadolinium gallium garnet (Gd_3Ga_5O_12, GGG). Therefore, Gd_3MO_7 (M = Nb, Sb, and Ta) are promising alternatives for cryogenic cooling techniques, especially for the magnetic liquefaction of helium. | Large magnetic entropy change in weberite-type oxides Gd_3MO_7 (M = Nb, Sb, and Ta) | 10.1007/s11433-021-1834-4 |
2022-03-01 | The effects of variable cryogenic temperature on the mechanical and electromechanical properties are implemented for REBCO coated conductor (CC) tapes. A versatile facility was used to provide the successive cooling environment from room temperature (about 293 K) to 5 K with a cryogenic-type extensometer for the strain measurement of the tested samples. At different cryogenic temperatures, the mechanical parameters were measured during the REBCO CC tapes being stretched. The cryogenic temperature dependence of mechanical behavior, including elastic limit, offset yield strength and equivalent elastic modulus of the REBCO CC tapes with two different substrates were captured at different cryogenic levels. In addition, the tensile strain dependence of the critical current ( $${I}_{c}$$ I c ) of REBCO CC tapes with two different substrates at variable cryogenic temperatures was investigated, and the relations between $${I}_{c}$$ I c degradation and mechanical properties were revealed. The experimental results show that all the investigated mechanical parameters exhibit a temperature dependence. A uniaxial strain dependence of $${I}_{c}$$ I c is found under all the test temperatures, and the irreversible strains are between elastic limit and offset yield strains regardless of temperature for both two kinds of test specimens. | Cryogenic Temperature Dependence of Mechanical Properties and Strain Dependence of Critical Current of Commercial REBCO Coated Conductors | 10.1007/s10909-021-02655-y |
2022-03-01 | The integration of machining as a post-processing method for additive manufacturing (AM) can promote the industrialization of AM and enable it to meet the requirements of high-value industries. This integration introduces several challenges for the machining process, which are related to process design and planning. A major aspect that requires investigation is the cooling of the machining process. Effective cooling is a key part of the machining process, especially when hard materials with low machinability are involved, which is the case with parts built by AM. However, oil-based coolants cannot be utilized in the context of hybrid manufacturing because they contaminate the surface of the part that can lead to the introduction of defects in a successive AM process. Cryogenic cooling is a high-performance and sustainable cooling approach that can be employed to overcome this issue, since it provides a clean surface after the machining process. Although cryogenic cooling is a very promising and sustainable alternative for high-performance cooling, most studies only investigate limited benefits that it can provide in the machining process. Therefore, this paper aims to provide a full overview of the effect of cryogenic cooling with liquid nitrogen (LN_2) during milling of Directed Energy Deposited IN718 samples, examining the cutting forces, tool wear, surface roughness and residual stresses on the machined components. The results prove that cryogenic cooling can reduce significantly the cutting forces and tool wear, while its impact on the surface roughness is limited. | A comparative study of dry and cryogenic milling for Directed Energy Deposited IN718 components: effect on process and part quality | 10.1007/s00170-021-08313-7 |
2022-03-01 | This work mainly focuses on the effectiveness of both rake and flank face application of the different metal working fluid (MWF) strategies such as liquid CO_2, minimal quantity lubrication (MQL), and emulsion in face milling of Ti–6Al–4V alloy. Modified CoroMill 600 cutter via internal channels to both rake and flank faces of the inserts with PVD coated inserts were used for the studies. This novel approach of delivery of MWFs has been investigated on effective thermo-mechanical loads; in terms of the evolution of cutting temperature, cutting forces, and residual stresses. The hardness of the machined surfaces and chip microstructure analysis were also conducted to understand more about the mechanical and thermal load effects in machined material and observed parameters. It has been found that the effectiveness of both rake and flank application of the liquid CO_2 machining is a better alternative for the emulsion and MQL strategies. Low thermal deformation of the material, higher magnitude of compressive residual stresses, and lower thermal load throughout the machining cycle have been observed. However, an increase in the mechanical load was observed because of the cold strength hardening of the Ti–6Al–4V workpiece at the liquid CO_2 environment. These effects are negligible at room temperature after machining. Overall results show that the cryogenic machining offers best and lower thermal load effects over MQL and emulsion strategies for both rake and flank applications. | Mechanical and Thermal Load Effects of Novel MWFs Delivery Method in Milling of Ti–6Al–4V | 10.1007/s40684-020-00288-2 |
2022-03-01 | To prevent the spread of SARS-CoV-2 in cold-chain transportation in China, we developed specific cryogenic disinfectants. Carrier tests were performed against SARS-CoV-2 at − 20 °C for the four cryogenic disinfectants developed and qRT-PCR was used to test the virus RNA. Peracetic acid, chlorine disinfectants (two different concentrations), and quaternary ammonium disinfectant with their antifreeze can all inactivate SARS-CoV-2 in 5 min at − 20 °C. However, after 2–3 h of exposure, only chlorine disinfectant could destroy SARS-CoV-2 RNA. The viruses treated with peracetic acid and quaternary disinfectants showed positive Ct values even after 3 h detected with qRT-PCR. The conclusion was that the cold-chain disinfectants we tested could inactivate SARS-CoV-2 quickly and effectively, but only chlorine disinfectants could destroy nucleic acids in 3 h. Our study also illustrated that using qRT-PCR detection of viral nucleic acids to assess disinfection was inappropriate. | Effectiveness of Disinfectants Suitable for Inactivating SARS-CoV-2 at Cold-Chain Temperature | 10.1007/s12560-022-09509-0 |
2022-03-01 | Hydraulic fracturing is a commonly used stimulation method in developing tight sandstone reservoirs. Creation of complex fracture networks to enlarge stimulated reservoir volume plays an increasingly significant role. However, planar fracture patterns are generally generated by water-based fluid fracturing. Besides, the water consumption and environmental burden of water-based fluid fracturing cannot be ignored. To solve the above issues, we investigated the liquid nitrogen (LN_2) fracturing performance on tight sandstone with respect to breakdown pressures and fracture network patterns, and also compared the results with water fracturing in this paper. A comprehensive quantitative analysis was made for the fracture network induced by LN_2 fracturing so as to enhance understandings of the fracturing mechanisms. Based on laboratory fracturing experiments and computed tomography (CT) scanning, we find that the breakdown pressure of LN_2 fracturing can be reduced by 12.4–51.5% compared with water fracturing. Besides, LN_2 fracturing can lead to volumetric fracturing patterns rather than planar fractures compared with water fracturing. The average tortuosity of LN_2 fracturing was increased by 5.9% compared with water fracturing. Furthermore, the major fracture tends to traverse the bedding plane with an angle of around 45–80 degrees under lower horizontal stress difference. This study, for the first time, shows potential benefits of high-pressure LN_2 fracturing in tight sandstone under triaxial in situ stress. It is expected to provide a viable alternative for the efficient development of tight sandstone reservoirs in a clean and waterless way. The performance of liquid nitrogen fracturing on tight sandstone was investigated. A comprehensive quantitative analysis was made for the induced fractures. Liquid nitrogen fracturing can lower fracture initiation pressure as a comparison with water fracturing. Liquid nitrogen fracturing can lead to volumetric fracturing and enhance the stimulated reservoir volume. Major fracture tends to traverse the bedding plane with an angle under a lower horizontal stress difference. | Fracture Initiation and Morphology of Tight Sandstone by Liquid Nitrogen Fracturing | 10.1007/s00603-021-02755-x |
2022-03-01 | Alloys with combined outstanding strength and excellent ductility are highly desirable for many structural applications. However, alloys subjected to deformation at very high strain rates and/or cryogenic temperatures usually suffer from very limited ductility. Here, we demonstrate that a bulk CrCoNi medium-entropy alloy presents exceptional combination of high strength and excellent ductility during deformation at high strain rates over a wide temperature range. Full tensile stress-strain curves at a high strain rate of 2000 s^−1 and temperatures down to 77 K were successfully obtained using an electromagnetic Hopkinson tension bar system attached with a cooling device, revealing high true ultimate tensile strength ( σ _UTS,T) of 1.8 GPa and true strain of ∼54% at σ _UTS,T. These outstanding mechanical properties were mainly attributed to profuse deformation twinning. Both high strain rate and cryogenic temperature promoted deformation twinning. Grain refinement caused by deformation twinning, dislocation slip and dynamic recrystallisation added to work hardening and the excellent tensile strain. 拥有优异的力学强度和拉伸塑性对于结构合金是非常重要的. 然而, 合金在高应变速率或者低温下变形时通常拉伸塑性非常有限. 本 文展示了块体CrCoNi中熵合金在高应变速率和低温下优异的综合拉 伸力学性能. 我们使用一种带冷却装置的电磁霍普金森拉杆装置得到 了在2000 s^−1和77 K下完整的拉伸力学曲线. 结果表明合金在1.8 GPa下 具有超高的拉伸真应力( σ _UTS,T), 在 σ _UTS,T下的拉伸真应变为∼54%. 该合 金优异的力学性能主要归因于大量变形孪晶的启动. 高应变速率和低 温都促使了孪晶的形成. 变形孪晶、滑移、动态再结晶引起的晶粒细 化促进了加工硬化, 从而增加了拉伸塑性. | Exceptional high-strain-rate tensile mechanical properties in a CrCoNi medium-entropy alloy | 10.1007/s40843-021-1798-6 |
2022-02-18 | This study evaluated morphophysiological, and biochemical aspects of seeds of two bromeliad species, Vriesea reitzii and Vriesea philippocoburgii , after the cryopreservation of their capsules. The capsules were grouped according to the initial seeds moisture content, and stored at − 196 ºC (cryopreservation) and 4 ºC (non-cryopreservation). The seeds were then removed from the capsules and evaluated for germination, germination speed index (GSI) and formation of normal seedlings, in addition to a light microscopy analysis and the quantification of free polyamines. V. reitzii seeds with 29% of moisture content resulted in 65% of germination and higher GSI post-cryopreservation (30.4). Seeds with moisture contents of 41% and 55% did not germinate after cryopreservation and presented cellular alterations, such as vacuolation, vacuolar cell death and plasmolysis. V. philippocoburgii cryopreserved seeds presented a high germination rate (97%), not differing from non-cryopreserved seeds (99%). However, the percentage of normal seedlings obtained from cryopreserved seeds (73%) was lower than the percentage obtained from non-cryopreserved seeds (91%). There was an increase in the concentration of putrescine in cryopreserved seeds in the two species studied, probably associated with tolerance to damage resulting from exposure to freezing. Higher concentrations of spermidine and spermine were also found in V. reitzii seeds. Cryopreservation of capsules proved to be a viable alternative. However, it is recommended to desiccate the capsules or collect them at harvest maturation. | Morphophysiology and polyamine content in seeds from cryopreserved capsules of two Vriesea species | 10.1007/s11738-022-03377-8 |
2022-02-14 | This paper describes history and technical evolution of portable devices which use energy-dispersive X-ray fluorescence (EDXRF)-analysis to study works of art. The history starts in 1971, when the first transportable equipment was employed to examine the pigments of Raphael’s painting “La Deposizione” during restoration at the “Istituto Centrale del Restauro” in Rome. Then, paintings of all types were analyzed and metals (bronzes, brasses, gold and silver). The evolution of the exciting source is described (from radioisotopes or big size X-ray tubes, to miniaturized, dedicated X-ray tubes) and of X-ray detectors (from proportional gas counters, to N_2-cooled Si or Ge-detectors, to Peltier cooled HgI_2 and Si-PIN, to Peltier cooled Si-drift). Also, the pulse height analyzers had an important evolution, from a heavy box to a computer card, to very small electronic circuits included in the detector box. The most “modern” portable EDXRF device is currently composed of a small-size X-ray tube, a Si-drift detector, both properly collimated, a portable computer, and dedicated software for the processing of the data. The total weight of such a device is about 2 kg. The last evolution: from analysis of a limited number of points to a complete scanning of the artifact. A mechanics is also required, with a sophisticated software interfacing mechanics to measuring heads. Maps giving the distribution of all analyzed elements in all areas of the painting “La Fornarina” by Raphael could be obtained. Finally, an accurate analysis of the K or L-X rays of the elements present in the paintings allowed to determine the disposition of the pigment in the correct layer. | From Raphael (La Deposizione) to Raphael (La Fornarina): a Circumnavigation Accompanying the Evolution of Energy-Dispersive XRF Devices | 10.1007/s13538-021-01042-y |
2022-02-05 | Key message The immature seeds of Dendrobium nobile acquire resistance to freezing and long-term storage in a cryobank at the age of 6 months after pollination. Abstract Seed maturation of Dendrobium nobile Lindl to establish the optimal stage for long-term storage of immature seeds in liquid nitrogen was studied. Immature seeds can germinate in vitro starting from 3 months after pollination (MAP) but only develop up to the stage of embryo swelling or protocorm without rhizoids. The maximum staining of embryos with vital dyes FDA and TTC occurs at 4 and 5 MAP that corresponds to the release of suspensor beyond the embryo sac. Embryo staining does not correlate with germination capacity and seed viability in cryogenic storage. The immature seeds acquire resistance to drying in airflow and cryostorage at the age of 6 MAP. 11% of seeds germinated after cryogenic storage at 6 MAP, and 81–94% at 7–10 MAP. | Morphophysiology and cryopreservation of seeds of Dendrobium nobile Lindl. (Orchidaceae) at different stages of development | 10.1007/s11738-022-03372-z |
2022-02-01 | Valves are key components of the safety of fluid transportation systems because of induced disturbance and cavitation damage in them. In this study, a 2D model of a cryogenic globe valve with liquid nitrogen (LN_2) as working fluid was established by Fluent, and thermal effects were specially considered in the simulation. The validity of the LN_2 cavitation model was verified by the experimental data of hydrofoil LN_2 cavitation from earlier studies by NASA. Cavitation characteristics of LN_2 in the cryogenic globe valve under three typical working conditions were investigated. The average pressure and pressure pulse at different positions of the wall were further studied to reveal cavitation risks from fatigue and vibration. Results show that with similar valve structure and openings, the pressure pulsation frequencies of LN_2 are lower than those of water, and the shape and location of the cavitation clouds also show significant differences. For LN_2 cavitation, an extended period of valve opening at 66% should be avoided since its pressure pulse peak is the largest compared to openings of 33% and 100%, and reaches 5×10^7 Pa. The opening of 33% should also be monitored because of the large torque caused by the pressure difference between the two sides of the valve baffles. To prevent resonance, a critical state for the valve opening and the connecting pipe length is proposed. These predictions of cryogenic cavitation in the globe valve are helpful for the safe and reliable operation of cryogenic fluid transport systems. 目的 阀内流体空化将对阀门壁面产生冲击,造成气蚀剥蚀和噪音,并影响流体输运系统的安全运行。低温流体和常温流体物性区别大,并且低温流体空化有更为复杂的机理。本文旨在讨论低温截止阀内液氮空化的发展规律,并进一步研究空化对壁面产生的压力冲击,以及如何避免阀门系统发生共振,从而为阀门系统的安全运行提供参考。 创新点 1. 在数值模拟中加入能量方程,并考虑低温流体在空化过程中压力和温度的相互影响;2. 分析在不同阀门开度下液氮空化的发展过程和壁面不同位置受到的压力冲击。 方法 1. 利用Fluent空化模型和Mixture模型,建立低温截止阀空化模型(图3);2. 模拟不同开度下阀内液氮的空化过程(图6~9);3. 分析壁面各监测点的压力变化情况,提取压力幅值和流体脉动频率,并与阀门固有频率比较(图12,13,15和20)。 结论 低温截止阀内液氮空化呈现周期性特征,并且空化周期随阀门的开度增大而减小;2. 最大压力脉冲峰值出现在中等开度(66%);3. 最大振动位移出现在阀体处,且存在临界管长,使得阀门系统的固有频率和流体脉动频率相等。 | Cavitation evolution and damage by liquid nitrogen in a globe valve | 10.1631/jzus.A2100168 |
2022-02-01 | The use of cryogenic coolants as an alternative cooling technique has been applied widely in recent years because of the many problems associated with conventional cutting fluids. No paper has been published to date on the milling of AZ31 magnesium alloy under dipped cryogenic cooling approach. The comprehensive results from the experimental study have practical importance and provide valuable information for industrial production processes. In this study, milling tests were carried out on AZ31B magnesium alloy under various cutting speeds, feed rates, and depths of cut. During milling, the effects of liquid nitrogen on milling forces, chip formation, and surface roughness were examined and a damage analysis was also carried out. This study introduced a novel cryogenic approach in the milling of AZ31B magnesium alloy using a liquid nitrogen bath. A new experimental setup was prepared for performing milling tests with the approach. Based on the experimental results, it was concluded that using the dipped cryogenic approach improved (approximately 2–34%) the surface quality of the workpiece and provided shorter chip formation. In addition to these, in the tests carried out under dry cutting conditions, lower milling forces (approximately 16–88%) were formed compared to the cryogenic conditions. A surface damage analysis was also performed. | An Experimental Investigation on Machinability of AZ31B Magnesium Alloy under Dry and Dipped Cryogenic Approaches | 10.1007/s11665-021-06264-4 |
2022-02-01 | Hole shrinkage is a common phenomenon in drilling difficult-to-cut materials like Ti6Al4V due to their poor thermal properties and high elasticity, which can lead to increase in tool wear and decrease in surface integrity. In this study, an in-depth analysis of hole shrinkage mechanism is carried out through a hybrid modelling approach for both dry and cryogenic cutting conditions. The plastic deformation induced by chip formation and tool-workpiece interaction is treated as equivalent thermomechanical loads, and heat convection conditions are described along tool path in order to perform details in heat transfer process for both cases. Quantitative analysis is presented through numerical simulation and experimental data of temperature and deformation along hole contour to analyze deformation components in order to reveal the hole shrinkage mechanism. Additional interactions between cutting tool and workpiece material are induced by recovery of elastoplastic deformation, and plastic portion is a more devastating factor in tool wear and surface damage induced by hole shrinkage. This study presents an in-depth and fundamental understanding of the hole shrinkage mechanism through a hybrid modelling approach, which can characterize heat transfer process during machining for both dry and cryogenic conditions, and simulation of this fully coupled thermomechanical cutting process with supply of coolants was rarely reported in previous research. The results show that plastic deformation induced hole shrinkage can enhance the interaction between workpiece material and cutting tool, and cryogenic assistance presents a good performance in restricting this kind of phenomenon. The related results could be used to optimize strategies of eliminating hole shrinkage with cryogenic assistance in industrial applications. | A hybrid modelling approach for characterizing hole shrinkage mechanisms in drilling Ti6Al4V under dry and cryogenic conditions | 10.1007/s00170-021-08229-2 |
2022-02-01 | By combining cryo-rolling and post-annealing treatments, the nanostructured NiTi alloy is produced. A differential scanning calorimetry measurement was used to test the effect of the preparation process on phase transformation. The cryo-rolling changes the tensile fracture of NiTi alloy to a ductile manner. Interestingly, the recovered structure exhibits significant strength improvement, while the tensile plasticity is still comparable to that of the coarse-grained structure. This optimized mechanical performance is due to the strengthening effect of refined microstructure and the high work hardening capability rendered by moderate dislocation density. Ball-on-plate reciprocating dry-sliding wear test reveals that the nanostructured NiTi alloy also has enhanced wear resistance, which is primarily ascribed to the high content of residue martensite formed during cryo-rolling. These results provide an effective route to optimize the mechanical and wear properties of NiTi alloys. | Improving the Mechanical and Tribological Properties of NiTi Alloys by Combining Cryo-Rolling and Post-Annealing | 10.1007/s40195-021-01253-x |
2022-02-01 | Abstract — The radiochemical and neutron-physical characteristics of a pelletized cryogenic moderator based on a mesitylene mixture (a mixture in the form of frozen pellets) obtained during its operation at the pulsed fast reactor IBR-2 are presented. It is shown that changes in the properties of the mixture at high absorbed-irradiation doses (~100 MGy) have no significant effect on the spectrum of cold neutrons. The gain in the number of cold neutrons from the surface of a cold moderator in comparison with a water moderator reaches 10 times. There is no deterioration in the neutron flux at the end of the reactor duty cycle. If the technology of continuous modification of the working substance in the cryogenic moderator chamber is successfully developed, the frozen mixture of mesitylene and m -xylene can be recommended for use on powerful pulsed neutron sources. | Some Features of the Operation of Pelletized Cryogenic Mesitylene-Based Moderators at the IBR-2 Pulsed Fast Reactor | 10.1134/S1027451022010037 |
2022-02-01 | In this study, a cryogenic abrasive air jet machining (CAAJM) experimental system is designed and built based on the glass transition characteristics of polydimethylsiloxane (PDMS). Fixed processing parameters are then used to evaluate the effectiveness of machining PDMS by abrasive air jet machining (AAJM) at room and cryogenic temperatures, and the results show that cryogenic could improves the processing quality of PDMS. Furthermore, the potential effects of cryogenic treatment on the mechanical properties and wettability of PDMS were analyzed. The results showed that the mechanical properties was slightly decreased under cryogenic treatment, but the wettability was slightly increased. These resulted will further promote the application of CAAJM in the field of microfluidic analytical system. Based on this, experiments are conducted into how microchannel processing quality is influenced by the scanning speed and the erosion distance, pressure, and angle. The results show that better PDMS microchannels are processed when the erosion distance is 2.5–3.5 μm, the erosion pressure is 0.4 MPa, the erosion angle is 60–75°, and the scanning speed is 0.25 mm/s. | Experimental investigations of machining characteristics on polydimethylsiloxane (PDMS) by cryogenic abrasive air-jet machining | 10.1007/s00170-021-08147-3 |
2022-02-01 | The results obtained are an experimental confirmation of the effect of the cryosurface material on the process of the onset of cryocondensation radiation during the condensation of gases such as nitrous oxide, ethanol, and methanol. It is shown that regardless of the material of the optical system of the surface, whether it is a metal mirror or a mirror covered with a film of the cryocondensates of a dielectric having an intrinsic dipole moment or with a zero-dipole moment while maintaining the thermodynamic parameters and formation conditions, the cryoradiation process will exist in the visible spectral range. This fact is a constructive proof of selection and calculation of low-temperature surfaces in specific conditions of their functioning. | The Effect of the Cryosurface Materials on the Cryoemission Parameters of Some Gases | 10.1007/s10909-021-02648-x |
2022-02-01 | Inconel 718 is famous for its applications in the aerospace industry due to its inherent properties of corrosion resistance, wear resistance, high creep strength, and high hot hardness. Despite the favorable properties, it has poor machinability due to low thermal conductivity and high hot hardness. To limit the influence of high cutting temperature in the cutting zone, application of cutting flood is recommended during the cutting operation. Cryogenic cooling is the recommended method when machining Inconel 718. However, there is very limited literature available when it comes to the numerical finite element modeling of the process. This current study is focused on the machinability analysis of Inconel 718 using numerical approach with experimental validations. Dry and cryogenic cooling methods were compared in terms of associated parameters such as chip compression ratio, shear angle, contact length, cutting forces, and energy consumption for the primary and secondary deformation zones. In addition, parameters related to chip morphology were also investigated under both lubrication methods. Chip formation in cryogenic machining was well captured by the finite element assisted model and found in good agreement with the experimental chip morphology. Both experimental and numerical observations revealed comparatively less chip compression ratio in the cryogenic cooling with larger value of shear plane angle. This results in the smaller tool–chip contact length and better comparative lubrication. | Machinability analysis of dry and liquid nitrogen–based cryogenic cutting of Inconel 718: experimental and FE analysis | 10.1007/s00170-021-08173-1 |
2022-02-01 | Metal Matrix Nano Composites (MMNCs) are progressive alternatives of formal metal materials, are presently accomplishing a growing inclination of research and engineering approaches for challenging operations such as aviation, nuclear power, and automotive for the improved mechanical properties and comparatively light in weight. Machining these MMNC leftovers, however, is a stimulating task as an effect of its mechanical heterogeneity, which primes the product of rapid wear of the tool to worsen the integrity of the surface at the point of machining. This article presents cryogenic Machining (CM), Minimum Quantity Lubrication (MQL) and Dry Machining (DM) of Nano SiC reinforced Al matrix composite and its induced surface integrity characteristics such as surface roughness, burr height and microhardness. The drilling experiments are carried out computer numeric control (CNC) machine considering a carbide drill with dia of 10 mm having a contact point of 90^o, 118^o, and 135^o. The Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDAX), Atomic Force Microscope (AFM), and Vickers microhardness test are used to assess the subsurface deformation and morphology. An evolutionary Non-dominated Sorting Genetic Algorithm - II (NSGA-II) is used for improving the performances such as surface roughness (SR) and burr height (BH) subjected to distinct cooling environments. The results showed that minimal SR and BH are 0.29 μm and 0.23 mm respectively under 500 rpm, 50 mm/min feed, 90^0point angle, and 1% wt of Nano SiC and CM shows reduced depth of plastic deformation in the subsurface of machined composites. The FESEM results show that the better surface finish are found on MMNC surface when machined under CM. | Sustainable Drilling of Nano SiC Reinforced Al Matrix Composites Using MQL and Cryogenic Cooling for Achieving the Better Surface Integrity | 10.1007/s12633-021-00977-w |
2022-02-01 | In this paper, operational principles of a cryogenic memory cell that utilizes high-temperature superconductors (high-T_c) are presented. Such a cell consists of three inductively coupled Josephson junctions coupled via inductors. Design and operational logic of this type of cell were recently introduced and demonstrated for low temperature 4 K environment. The basic memory cell operations (read, write, reset) can be implemented on the same simple circuit and both destructive and non-destructive memory cell operations can be realized. Here, we present the design principles and computational validation of basic memory cell operations (write, read, and reset) for the high-T_c memory cell. Our results for the high-T_c memory cell operations show very good resemblance with the previously presented low-temperature 4 K memory cell operations. | High-T_c Superconducting Memory Cell | 10.1007/s10948-021-06069-5 |
2022-02-01 | Abstract This letter consider arrays of vertically oriented silicon wires obtained by cryogenic dry etching of silicon substrates with a free electron density of n = 10^16 and 10^17 cm^–3, a height of 6 µm, and a diameter of 1.7 and 1.2 µm, respectively. It is shown that gold sputtering makes it possible to form a Schottky diode with an ideality factor of 1.1–1.3 and a barrier height of 0.6–0.7 eV relative to the given parameters of these arrays. It is shown that the experimental capacitance–voltage characteristics of such structures can be analyzed using a model taking into account the contribution to the capacitance from the entire surface of the wires. This made it possible to numerically estimate the density profile of free charge carriers precisely in the wire array, which showed good numerical agreement with the doping level in the original substrates. | Study of Schottky Diodes Based on an Array of Silicon Wires Obtained by Cryogenic Dry Etching | 10.1134/S106378502202002X |
2022-02-01 | Hybrid superconductor-ferromagnet materials have gained huge attention due to their opposite nature of electronic states, bringing up new properties and applications when coupled together. Cryogenic sensors and memories research significantly lag behind their conventional counterparts. Here, we investigated numerically the strain/motion sensing ability of superconductor-ferromagnet bilayer using Ginzburg–Landau equations for superconductivity and Landau-Lifshitz-Gilbert equations for ferromagnetism. Clear segregation of average carrier concentration of the superconductor layer, which defines its conductivity, was observed with various magnitudes of strain (i.e. 0%, 1%, and 5%). The current purge was used to bring the designed sensor to its ground state, whereas the sensor retained the information on the amount of strain for the extended period unless reset (by the current purge) for reuse. This work opens up a new direction for superconductor-ferromagnet bilayer device applications towards strain/motion sensors and/or transducers. | Phase-Field Simulation of Superconductor-Ferromagnet Bilayer-Based Cryogenic Strain Sensor | 10.1007/s10948-021-05959-y |
2022-02-01 | To reveal the causes of infrared absorption in the wavelength region between electronic and lattice absorptions, we measured the temperature dependence of the absorption coefficient of p -type low-resistivity ( $$\sim 10^2~ \Omega \mathrm{cm}$$ ∼ 10 2 Ω cm ) CdZnTe crystals. We measured the absorption coefficients of CdZnTe crystals in four wavelength bands ( $$\lambda =6.45$$ λ = 6.45 , 10.6, 11.6, 15.1 $$~\mu $$ μ m) over the temperature range of $$T=8.6$$ T = 8.6 -300 K with an originally developed system. The CdZnTe absorption coefficient was measured to be $$\alpha =0.3$$ α = 0.3 -0.5 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=300$$ T = 300 K and $$\alpha =0.4$$ α = 0.4 -0.9 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=8.6$$ T = 8.6 K in the investigated wavelength range. With an absorption model based on transitions of free holes and holes trapped at an acceptor level, we conclude that the absorption due to free holes at $$T=150$$ T = 150 -300 K and that due to trapped-holes at $$T<50$$ T < 50 K are dominant absorption causes in CdZnTe. We also discuss a method to predict the CdZnTe absorption coefficient at cryogenic temperature based on the room-temperature resistivity. | Infrared Absorption and Its Sources of CdZnTe at Cryogenic Temperature | 10.1007/s11664-021-09361-1 |
2022-01-07 | In this study, an investigation was conducted on the effect of cryogenic heat treatment on the wear behavior of AZ91 magnesium alloy using pin-on-disc in a dry and isotonic solution (0.9 wt% NaCl) medium. The wear performance was investigated under loads of 1 N, 3 N, and 5 N. The analysis of the variance method was performed to find the relationship between parameters. The results from the experiment showed that the new microstructure of treated AZ91 was composed of less eutectic phase around β phase and the formation of twin phase was noticed compared to untreated AZ91. The wear analysis demonstrated that in dry and wet medium abrasion and adhesion mechanisms were dominant. Although the untreated sample exhibited better wear resistance in the dry medium, the cryogenically treated sample was better in the wet medium when compared to the wear zone. In addition, the pitting corrosion was observed for all samples in the wet medium; the treated sample had encountered severe pitting compared to the untreated sample. Moreover, the specific wear rate of the treated sample was better than the untreated sample at the wet medium. The coefficient of friction (COF) of the untreated sample was between min. 0.32 and max. 0.54 and higher than the treated sample in the dry medium. However, the COF value of the wet medium was less than a dry medium for all samples and was around 0.24. In general, the treated sample performed better wear resistance in wet medium and was limited at dry medium depending on the applied load. | The effect of deep cryogenic treatment on the wear properties of AZ91 magnesium alloy in dry and in 0.9 wt% NaCl medium | 10.1007/s12046-021-01794-y |
2022-01-01 | One of the primary drawbacks limiting the use of superconductive electronics is the lack of a fast and dense memory capable of operating within a cryogenic environment. Recent research suggests the use of cryogenic spin-based memory—magnetic tunnel junctions (MTJ) and spin valves (SV). In this chapter, a sense amplifier topology for a spin-based cryogenic memory cell is proposed and described. The nanocryotron (nTron) device is used as a driver for a spin-based memory element—the cryogenic orthogonal spin transfer (COST) device. A clocked DC-to-SFQ converter is used as a sense amplifier to resolve small differences in the readout current. The sense amplifier produces a variable number of SFQ pulses to represent different analog states by passing or blocking input clock pulses. This clock is derived from the system clock by synchronizing the read pulse to the same clock signal. These output pulses are counted and converted into a binary form. The sense amplifier exploits the specific shape of the nTron output waveform characterized by an L/R time constant to achieve the resolution of low magnetoresistance (MR) memory cells, and is adaptable to different nTron sizes, bias currents, and spin-based devices. The dynamic power dissipation and resolution of the sense amplifier can be adjusted by the frequency of the applied clock signal, allowing the resolution to be reduced for high MR devices. The sense amplifier consists of two Josephson junctions, requiring little area, particularly in comparison to a standard nTron device, and can therefore be connected to each column of the memory array. | Sense Amplifier for Spin-Based Cryogenic Memory Cell | 10.1007/978-3-030-76885-0_10 |
2022-01-01 | In this research work, the stainless steel (SS) used for the fabrication of under-water parts in hydro-power plants was cryo-treated at different ultra-low temperatures, i.e. −80 ℃ and −196 ℃. The influence of such cryo-treatments on the silt erosion performance of SS-316L was investigated by conducting silt erosion tests on a self-fabricated jet model silt erosion trial apparatus. The tests were regulated for distinct operating parameters at two levels. It was found that the cryogenic treatments significantly affect the silt erosion performance of stainless steel samples. Scanning-electron-microscopy (SEM) and optical microscopy (OM) tests were done to examine the microstructural changes resulted after cryo-treatments. SEM results endorse the existence of residual austenite in the untreated steel. However, this residual aust. disappears after such cryo-treatments. XRD diffraction techniques were also used to investigate the various phase changes caused by low-temperature treatments. It was concluded that the samples, cryogenically treated at −196 ℃ exhibits the highest resistance against silt erosion followed by the one treated at −80 ℃. The untreated samples of SS-316L showed the least resistance against silt erosion. This upgradation in wear strength of cryogenically processed samples was further related to the metallurgical changes observed after cryogenic treatment. | Influence of Ultra-low Temperature Treatments on the Slurry Erosion Performance of Stainless Steel-316L | 10.1007/978-981-16-2794-1_109 |
2022-01-01 | Superconductive circuits are introduced in this chapter. Both analog and digital circuits are described, and memory topologies are presented. Among the analog devices, single and two junction SQUIDs are introduced along with characteristic expressions and common applications. Different families of superconductive digital logic, such as voltage level logic, rapid single flux quantum logic, reciprocal quantum logic, and adiabatic quantum flux parametron logic, are described. The basic principles of adiabatic and reversible computing are also reviewed. Finally, different types of cryogenic memory are introduced and the advantages and disadvantages of these memory topologies are discussed. | Superconductive Circuits | 10.1007/978-3-030-76885-0_3 |
2022-01-01 | The problem issues of non-drainage storage of cryogenic fuels in modern modular long-term storage systems are considered. The structure of software for remote monitoring the container and small-scale reservoir equipment for storage and transportation of cryogenic fuel is presented. The relationship of software modules for computational modeling of hydrodynamic and thermodynamic processes during storage of cryogenic fuel in stationary and transport conditions, a module for calculating the holding time of non-drainage storage, and individual data transmission modules installed on cryogenic tanks are disclosed. The composition of the software of operators responsible for remote monitoring of the state of multimodal transport units during transportation and long-term storage at the point of consumption is described. An example of energy-efficient technical solution for increasing the holding time of non-drainage storage of liquefied natural gas during storage and transportation in multimodal transport units are considered. In the autonomous power supply system of the multimodal transport unit under consideration, the conversion of solar energy is used to charge accumulator batteries. The results of calculations of electricity consumption for increasing the holding time up to values of 150–200 days, demanded by consumers of cryogenic fuel, are presented. | Issues of Energy-Efficient Storage of Fuel in Multimodal Transport Units | 10.1007/978-981-16-2814-6_34 |
2022-01-01 | In this chapter, the book is concluded. The advantages and prospective application areas of superconductive circuits are reviewed. The primary challenges to large scale integration of superconductive digital systems are reviewed, and solutions to these issues are summarized. Finally, the primary objectives of this book are also discussed. | Conclusions | 10.1007/978-3-030-76885-0_17 |
2022-01-01 | Multilayer insulation (MLI) is an important thermal protection system which is used in space cryogenic programs as well as on the ground experiments also. For the continuous and reliable functioning of a cryostat, it is desired to have a minimum heat load to the inner wall of the cryostat, and the need of minimum heat load (radiation heat load in particular) can be well fulfilled by using the MLI technique. It is used to reduce the radiation heat load mainly in the cryostats by placing the radiation shields and spacers in the gap between the two walls (hot and cold surfaces) of the cryostat. The present work is focused on investigation of the suitable reflective layer and spacer materials in MLI systems. In our analysis, Perforated Double-aluminized Mylar (DAM) with Dacron, Unperforated DAM with Silk-net, and Perforated DAM with Glass-tissue have been selected for their evaluation as the reflective layer as well as spacer materials in MLI technique. Current work would discuss the effect of layer density to optimize the layer density and the effect of the number of layers on the heat load. Knowing the key parameters of MLI, the heat load generation in spherical as well as cylindrical cryostats has been compared and the different effect of shielding of the cryostat placing a single layer near the inner or near the outer wall of the cryostat. | Quantifying the Performance of Multilayer Insulation Technique for Cryogenic Application | 10.1007/978-981-19-2592-4_21 |
2022-01-01 | The paper summarizes the research results that are achieved in the course of solving pressing challenges in continuous operation of the roadbed on the Berkakit-Tommot-Yakutsk Railway Line, AO Yakutsk Railroad Co. The line runs on the territory with adverse natural climatic and frozen ground conditions as well as complex hydrogeological and engineering conditions that are characteristic for Sakha Yakutia. The solutions are made for maintenance and repair works taking into account increasing loading and influence of global warming. The Guidelines are developed for a perspective application of the target-focused complexes of anti-deformation measures on the roadbed of railroads in Sakha Yakutia when the roadbed is differentiated according to forecasted failures and risks. | Challenging Issues of Long-Term Operated Roadbed on Berkakit-Tommot-Yakutsk Railway Line | 10.1007/978-3-030-96383-5_117 |
2022-01-01 | The precipitation Precipitation process was studied during the isothermal aging Aging of a Fe-12Cr-10Mn-12Ni-5Mo-0.24 N-0.03C steel at temperatures of 700, 800, and 900 °C for times up to 1000 min. The aged specimens were characterized by SEM, XRD analysis, and CVN impact test at –196 °C. Thermo-Calc analysis indicated that the Mo-rich M_6C carbide precedes the precipitation Precipitation of Cr-rich M_2N nitrides in the austenite matrix at aging Aging temperatures lower than 700 °C. The fastest growth kinetics of intragranular takes place at about 800 °C for the M_6C carbide and 850 °C for the M_2N nitride. The CVN impact energy decreases with aging Aging time and temperature. The presence of brittle fracture also increases with aging Aging time and temperature in the tested specimens. The intergranular precipitation Precipitation was the main responsible for the reduction of cryogenic toughness Cryogenic toughness . | Precipitation Process During Isothermal Aging of an Austenitic Stainless Fe-12Cr-10Mn-12Ni-5Mo-0.24 N-0.03C Steel and Its Effect on the Mechanical Properties | 10.1007/978-3-030-92381-5_138 |
2022-01-01 | The operational perspectives of exploitation foreses increasing loads according to the Russian president’s statement to the Federal Assembly, his edict on strategic development of Russian Federation for the period until 2024 (May, the 7^th 2018) and the program Strategies 2030. The challenges that can arise in this connection need their solutions. The paper summarizes the research results that are achieved in the course of solving pressing challenges in continuous operation of the roadbed on the Berkakit-Tommot-Yakutsk Railway Line, AO Yakutsk Railroad Co. The Guidelines help to provide the roadbed stability operation in specific landscape and geocryological areas of the rail road when the above mentioned and some economic factors are taken into account. The freeze-thaw processes are accompanied by uneven heaving and the roadbed subsidence as well as cryogenic processes (icing, frost splitting, etc.). | Solving Stabilization Problems Roadbed on Berkakit-Tommot-Yakutsk Railway Line | 10.1007/978-3-030-96383-5_118 |
2022-01-01 | Gravitational wave astronomy is a new and exciting field but has a long history as well as a bright future. The first detections of gravitational waves were from instruments of the second generation of detectors – the first generation of kilometer-scale ground based detectors operated as planned, but did not conclusively observe gravitational waves. The second-generation detectors (Advanced LIGO and Advanced Virgo) opened the field, and the third-generation detectors will expand our view of the gravitational wave universe to cosmic distances. This chapter will discuss the technological research and development required to build these third-generation detectors. | Research and Development for Third-Generation Gravitational Wave Detectors | 10.1007/978-981-16-4306-4_8 |
2022-01-01 | Major applications of composites are lightweight in aerospace applications and modern fasteners for reducing the weigh purpose, in this concern composites are very difficult for machines due to non-homogeneous and anisotropic environment and it require unique cutting tools. This work is going to investigate a comparative study of various conditions like Dry condition, Wet condition, and Cryogenic condition machining (turning) of UD-GFRP composite round with Polycrystalline diamond tool in the Lathe. The responses which measure the machining quality are: the tool wear, quality of the surface, and forces generated at various stages of inputs given to the machining of UD-GFRP composite. The optimization technique, i.e., Taguchi L9 orthogonal array is used for examinations and finding out the targeted values. The design includes three independent variables at three levels, the proposed process control independent variables are: rate of feed of tool, spindle speed or velocity of cutting, and operation depth tool in the work. The investigation aims to establish the process control by studying the relationship between Dry, wet, and Cryogenic machining condition level of inputs and degree of responses to identify the optimal level of process inputs for acceptable surface quality with minimal tool wear and cutting force condition. | A Comparative Study and Optimization of Parameters of Turning UD-GFRP in Dry, Wet and Cryogenic Condition by Using PCD Tool with Taguchi Method | 10.1007/978-981-16-7787-8_8 |
2022-01-01 | For a specific application, material selection for the production of a product plays a crucial role in the efficiency of the product. It is a multi-criteria decision-making (MCDM) issue to choose the appropriate content, as the selection depends on different criteria that are usually opposed in nature. This paper aims to address the issue of material selection using a combined compromise solution (CoCoSo). This method combined a compromise decision algorithm with an aggregation strategy to obtain a compromise solution. Two illustrative examples related to material selection, i.e., for a cryogenic storage tank and wagon wall material selection, are considered in this paper, and CoCoSo method is applied to rank the available substitute materials to select the best one. | Application of Combined Compromise Solution Method for Material Selection | 10.1007/978-981-16-5371-1_34 |
2022-01-01 | Abstract Though polymer composites are high-strength promising material, their wear damage is a real matter of concern in practical applications. Thus, to improve their wear performance, the polymers and composites are now increasingly being subjected to cryogenic treatment. Thus, an attempt has been made to cryogenically treat fiber and particulate-reinforced PBT composites and evaluate their structural and mechanical properties. In addition to this, as the interface between the filler and matrix material has a decisive effect on composite properties, the interface was also investigated and the change at the interface was monitored and evaluated through theoretical predictions as well. This work concludes that cryogenic treatment is rather effective for improving the mechanical properties of polymer composites, without compromising its structural integrity. The wear performance of the glass fiber-reinforced and wollastonite-reinforced PBT composites enhances by almost 84% and 96%, respectively, when treated at − 185 °C for 8 h. Graphic abstract | Effectiveness of cryogenic treatment on PBT composites: prediction of interfacial interaction parameter and its influence on filler bonding and wear performance | 10.1007/s00289-020-03501-z |
2022-01-01 | Over large areas of the Asian part of Russia, air temperatures remain below 0° C for a long time, leading to the transition of water from a liquid to a solid state and vice versa. Climate warming gradually leads to a decrease in the role of cold in the heat and moisture circulation of these territories. Permafrost degradation occurs in the permafrost zone. In temperate latitudes, seasonal freezing of soil and grounds decreases or completely stops. All this leads to the beginning of environmental degradation. The purpose of this chapter is to assess the cumulative impact of the main cryogenic phenomena and processes on the underground recharge of Russian rivers and processes that form and occur in river basins: In riverbeds, catchments, swamps and wetlands, soils, fractured and loose rocks. The chapter also presents the authors' reflections on the evolution of stable and unstable structures in a «water flow-ice-channel sediments» system (in annual and multi-year cycles) while air temperature decreases, and also lists the main problems, according to the authors, arising in the assessment of natural groundwater resources based on hydrological data under climate change. As a result of the performed calculations, it was established that air temperature plays a significant role in the formation of almost 20% of the total annual river runoff in the temperate and northern latitudes of Russia with stable winters. The ongoing and forecasted increase in winter air temperature over these territories may gradually weaken cryogenic runoff regulation and noticeable changes in the water regime. | Influence of Cryogenic Processes and Phenomena on Minimum Runoff in Russia | 10.1007/978-3-031-12112-8_26 |
2022-01-01 | Abstract Based on the analysis of the sensitivity of mass to the initial change of parameters, an assessment is made of the transition from the traditional layout of a transport category aircraft to the blended wing body scheme followed by the transition to cryogenic fuels. As an example, a passenger airplane for 450–500 passengers with a range of 10,000 km is considered. A comparative analysis of the mass and fuel efficiency of the considered schemes is given. | Application of Integrated Layout for ”Cryogenic“ Transport Category Aircraft | 10.3103/S1068799822010020 |
2022-01-01 | One of the heavy lift launch vehicles being developed by ISRO uses semi-cryogenic stage. Semi-cryogenic stage uses Isrosene as a fuel and liquid oxygen (LOX) as the oxidizer. These propellants will be supplied at a specific flow rates to the rocket engine to develop the required thrust. Sloshing is an important phenomenon to be considered for liquid/cryogenic/semi-cryogenic stages in order to design control system for the launch vehicle. For modeling slosh for control system studies, mathematical parameters such as slosh frequency, slosh mass and its location are required to be evaluated. In addition to these parameters, damping also play a major role in containing the vehicle response due to slosh. In the present study the parameters required for mathematical modeling of slosh for control stability analysis are evaluated using two different FE codes. The requirement of damping and duration envisaged from control stability analysis is met by designing multiple ring baffles using semi-empirical relations. In addition to the above, the achievable damping values for the designed baffle and its effect on slosh parameters are also studied. | Numerical Slosh Studies of Multiple Ring Baffles in a Semi-Cryogenic Fuel Tank | 10.1007/978-981-16-8724-2_30 |
2022-01-01 | Carbon emissions worldwide is an issue of serious concern pertaining to its worrisome effects like global climate change, warming and ozone depletion. The natural and anthropogenic activities like forest fires, fossil fuel burning, respiration, decomposition of flora and fauna, geogenic activities and chemical changes in the rock beds, automotive and industrial exhausts, etc., all lead to an immense amount of CO_2 being produced. CO_2 is a greenhouse gas that traps solar heat and facilitates earth warming up to an extent of 66%. Hence, it is essentially required to reduce carbon emissions and sequester the carbon being produced effectively. Many upcoming and existing technologies are utilized for carbon-capturing such as carbon capture and storage (CCS), carbon sequestration utilizing rocks and hydrates, chemical looping separation, membrane technology, cryogenic carbon capture (CCC), absorption, and adsorption. Each one of these technologies are having its own merits and demerits and carbon capture potential. This review describes these technologies for carbon capture and reducing the carbon emission for the environmental safeguarding and combating the global warming and climate change effects. | Carbon Sequestration and Capturing Technologies—A Review | 10.1007/978-3-030-96554-9_6 |
2022-01-01 | The large-scale cryogenic fluid transfer systems used in various applications are commonly exposed to pressure oscillations caused by fluid transient phenomena. The analysis and experimentation of such system are made easy by developing scale-down models and performing numerous tests. A scaling procedure solely to fluid transient phenomena is developed by non-dimensionalizing the governing equations of fluid transient. The approach for developing scale-down model parameters is formulated using scaling laws and known physical laws. In addition, the method for analyzing the behavior of large-scale system from the scale-down model results is also established. Numerical tests are carried out to vindicate the developed procedure with the data available in the open literature. The methodology is successfully implemented to establish scale-down model for cryogenic systems transferring LOx and LH2. | A Scaling Procedure for Predicting Pressure Fluctuations Caused by Fluid Transient in Cryogenic Systems | 10.1007/978-981-16-6738-1_6 |
2022-01-01 | Fracture micro mechanism of cryogenically treated Cr-V ledeburitic tool steel was studied on fracture toughness testing specimens, by using the scanning electron microscopy and microanalysis. Experimental steel has been processed at different combinations of cryogenic temperatures (from the range −75 to −269 °C) and tempering regimes, producing different microstructures (martensite, retained austenite, carbides), hardness- and fracture toughness values (from the ranges 700–1000 HV and 13–20 MPa × m^1/2, respectively). Conventionally quenched the same steel was considered as a reference. Generally, the obtained fracture surfaces manifest combined low-energetic ductile/cleavage crack propagation mode. The low-energetic ductile mode is associated with the presence of small globular carbides (size < 0.3 μm) that are produced by cryogenic treatments. On the other hand, cleavage mode is more pronounced with increased matrix stiffness, which is caused by the precipitation of nano-scaled transient carbides within the martensite. Also, differences in role of crack propagation between various carbides were determined. These differences are caused by crystallography of these phases as well as by their size. While small globular carbides (cementite) and dominant amount of the eutectic carbides (cubic MC-phase) assist more probably (by 50–60%) in ductile micro mechanism the coarser secondary particles (hexagonal M_7C_3-phase) are much more prone to cleavage cracking. This tendency increases with decreasing steel hardness since the matrix becomes more plastic, and the carbides cannot deform together with the matrix as they are much more brittle. | Fracture Micro Mechanism of Cryogenically Treated Ledeburitic Tool Steel | 10.1007/978-981-16-8810-2_6 |
2022-01-01 | The mycobacteria genus is responsible for numerous infectious diseases that have afflicted the human race since antiquity—tuberculosis and leprosy in particular. An important contributor to their evolutionary success is their unique cell envelope, which constitutes a quasi-impermeable barrier, protecting the microorganism from external threats, antibiotics included. The arabinofuranosyltransferases are a family of enzymes, unique to the Actinobacteria family that mycobacteria genus belongs to, that are critical to building of this cell envelope. In this chapter, we will analyze available structures of members of the mycobacterial arabinofuranosyltransferase, clarify their function, as well as explore the common themes present amongst this family of enzymes, as revealed by recent research. | Structure and Function of Mycobacterial Arabinofuranosyltransferases | 10.1007/978-3-031-00793-4_12 |
2022-01-01 | Cryogenic electron microscopy (cryo-EM) has recently emerged as an optimal technique for the determination of histone methyltransferase-nucleosome complex structures. Histone methyltransferases are a group of enzymes that posttranslationally methylate histone lysine and arginine residues on the nucleosome, providing important epigenetic signals that regulate gene expression. Here we describe a protocol to solve the structure of histone lysine methyltransferase Dot1L bound to a chemically ubiquitylated nucleosome, including complex reconstitution, crosslinking, grid preparation, and data collection and analysis. Throughout, we discuss key steps requiring optimization to allow this protocol to serve as a starting point for the determination of new histone methyltransferase-nucleosome complex structures. | Determination of Histone Methyltransferase Structures in Complex with the Nucleosome by Cryogenic Electron Microscopy | 10.1007/978-1-0716-2481-4_8 |
2022-01-01 | This novel work focuses on turning Inconel 718 alloy using different sustainable lubricating-cooling techniques. Cryogenic machining (Cryo), minimum quantity lubrication (MQL) and nanofluid MQL (NFMQL) were applied and their performances in terms of obtainable surface integrity evaluated in comparison with dry cutting (dry) and wet machining (wet). The surface integrity was analyzed from the aspect of surface roughness, surface morphology and defects, microhardness, microstructure, and chip morphology. The experimental results revealed that Cryo offered overall better performances when compared to dry, wet, MQL and NFMQL strategies: lower surface roughness, fewer surface defects and lower chip compression ratio were observed. Furthermore, increasing the cutting speed led to higher surface roughness and incidence of surface defects for all the applied strategies, except for Cryo. | Surface Integrity Evaluation When Turning Inconel 718 Alloy Using Sustainable Lubricating-Cooling Approaches | 10.1007/s40684-021-00310-1 |
2022-01-01 | Purpose To evaluate the DNA integrity and developmental potential of microwave-dehydrated cat spermatozoa after storage at − 20 °C for different time periods and/or overnight shipping on dry ice. Methods Epididymal spermatozoa from domestic cats were microwave-dehydrated on coverslips after trehalose exposure. Dried samples were either assessed immediately, stored for various duration at − 20 °C, or shipped internationally on dry ice before continued storage. Dry-stored spermatozoa were rehydrated before assessing DNA integrity (TUNEL assays) or developmental potential (injection into in vitro matured oocytes followed by in vitro embryo culture for up to 7 days). Results Percentages of dried-rehydrated spermatozoa with intact DNA was not significantly affected ( P > 0.05) by desiccation and short-term storage (range, 78.9 to 80.0%) but decreased ( P < 0.05) with storage over 5 months (range, 71.0 to 75.2%) compared to fresh controls (92.6 ± 2.2%). After oocyte injection with fresh or dried-rehydrated spermatozoa (regardless of storage time), percentages of activation, pronuclear formation, and embryo development were similar ( P > 0.05). Importantly, spermatozoa shipped internationally also retained the ability to support embryo development up to the morula stage. Conclusion Results demonstrated the possibility to sustain DNA integrity and developmental potential of spermatozoa by dry-preservation, even after long-term storage and long-distance shipment at non-cryogenic temperatures. While further studies are warranted, present results demonstrate that dry preservation can be a reliable approach for simple and cost-effective sperm biobanking or shipment. | Desiccated cat spermatozoa retain DNA integrity and developmental potential after prolonged storage and shipping at non-cryogenic temperatures | 10.1007/s10815-021-02337-4 |
2022-01-01 | Machining is one of the highly important manufacturing processes. The global machining market is currently estimated to be worth $341.91 billion. As per Beroe’s machining industry analysis reports, the global market size is expected to reach $414.24 billion by 2022. So as the market so vast and big and the use of machining is so high in manufacturing industries, therefore, there is a lot of research going on various machining techniques to get more efficient, economical and environment-friendly machining process. One such technique is cryogenic machining in which we replace the traditional machining fluid with cryogenic coolant which is very low temperature coolant as there are several disadvantages of traditional cutting fluids in various domain which has been discussed in the paper briefly. Therefore, in this paper, we will be talking about both of these techniques over various factors such as tool wear, surface roughness and hardness and environmental aspects, and we will find out how application of cryogenics affects these machining factors and final machined product. | A Comparison Study between Conventional and Cryogenic Machining | 10.1007/978-981-16-7282-8_22 |
2022-01-01 | Voltage-gated calcium channels mediate calcium entry into cells in response to membrane depolarization. The high-voltage-activated Ca^2+ channels that have been characterized biochemically are complexes of a pore-forming α1 subunit of ~200–250 kD, a transmembrane, disulfide-linked complex of α2 and δ subunits, an intracellular β subunit, and in some cases a transmembrane γ subunit. The α1 subunits form the transmembrane pore. The α2 and δ subunits are glycoproteins encoded by the same gene and produced by posttranslational proteolytic processing followed by attachment of a lipid anchor. The γ subunits are transmembrane glycoproteins, whereas the β subunits are hydrophilic proteins located on the cytosolic face of the channel. In this chapter, I have reviewed early work that led to identification, purification, and characterization of the protein subunits of calcium channels and presented more recent studies that have given clear insights into the structural basis for calcium channel function from X-ray crystallography and cryoelectron microscopy. | Subunit Architecture and Atomic Structure of Voltage-Gated Ca^2+ Channels | 10.1007/978-3-031-08881-0_2 |
2022-01-01 | In this chapter, superconductive electronics are introduced as a promising beyond-CMOS technology. The history of superconductive electronic circuits is briefly reviewed, highlighting similarities and differences in the development of semiconductor-based electronics. Modern computing systems are often categorized based on the total power consumption. The increasing importance of large scale, stationary computing systems is emphasized. The advantages of superconductive electronics for this important application area are described. Additional application areas, such as space-based electronics and quantum computing, are also introduced. Finally, the outline of the rest of this book is provided in this chapter. | Introduction | 10.1007/978-3-030-76885-0_1 |
2022-01-01 | The suitability of cryogenic vacuum extraction for sampling free water (F-water) extracted from environmental materials (grass and soil) was examined with respect to low-level (~ 1 Bq L^−1) and precise determination of tritium (^3H) concentrations in the extracted water. Tests were conducted using addition-recovery experiments of water containing low ^3H activity concentrations (0.43 ± 0.046 Bq L^−1) added to dried grass or soil. The results revealed that ^3H concentrations in F-water did not significantly differ before and after cryogenic vacuum extraction in both experiments. This suggests that the cryogenic vacuum extraction is useful for sampling F-water to determine ^3H concentration in the water. | Cryogenic vacuum extraction scarcely changes low-level tritium (^3H) concentrations in free water extracted from environmental samples | 10.1007/s10967-021-08074-3 |
2022-01-01 | This chapter focuses on the energy saving and CO_2 mitigation in the industry’s activities in the usage of fossil oil, low-carbon and renewable energy. It covers the topics of CO_2 production, capture and storage in the energy industries. It also discusses CO_2 application in the chemical industries. Ten industrial operation case studies are used in the chapter which have covered different aspects in the CO_2 Generation, CO_2 Capture, Delivery, Storage and Application. The operations are supported with detailed process simulations, and the results are presented for reference by readers. These cases are: Nature gas CO_2 capture via acid gas enrichment—Case study 1; Cascade sour nature gas CO_2 capture—Case study 2; Acid Gas Enrichment and CO_2 Capture—Case Study 3; Syngas CO_2 Capture with single absorber using DEPG solvent—Case study 4; Syngas CO_2 Capture with dual absorber using DEPG solvent—Case study 5; Flue gas CO_2 Capture using DEA solvent—Case study 6; Flue gas CO_2 capture using oxygen instead of combustion air—Case Study 7; CO_2 dehydration and compression—Case study 8; Flue gas CO_2 Capture, compression and dehydration—Case study 9; Flue gas Cryogenic CO_2 Capture—Case Study 10. A newly developed CO_2 Capture Process by Cryogenics is discussed in the chapter. The innovative process will not require a contact liquid. There is no solid formation at the upstream of CO_2-de-sublimation, this eliminates the concern in the sold CO_2 transferring. | CO_2 Capture and Utilization | 10.1007/978-981-19-5295-1_10 |
2022-01-01 | Abstract— A specific group of diverse marsh soils forming on sea coasts in the permafrost zone is proposed to be included into the Russian soil classification system. These soils are affected both by cryogenic and sea processes. At present, there are several regional classifications of marsh soils forming in the European north and Far East of Russia and in northern Europe. We have developed a classification scheme for these soils at four higher taxonomic levels (from soil trunks to soil subtypes) of the Russian soil classification system using the data of soil studies on the accumulative seashores in the eastern sector of Russian Arctic. The studied soils are preliminary named as Thalassosols. According to the proposed scheme, they are categorized within three soil trunks, for which new orders are introduced. The order of initial marsh soils is suggested for the trunk of initial pedogenesis. In the trunk of organogenic soils, marsh soils can be separated at the type level within the newly proposed order of allochthonous organic soils. A new order of marsh soils is also suggested for the trunk of synlithogenic soils. Approaches to further subdivision of marsh soils at the lower (type and subtype) levels of the Russian soil classification system are discussed. A new symbol (؉) is suggested to single out the soil layers and horizons of synlithogenic marsh soils. Specific diagnostic features of the profiles of marsh soils in the permafrost zone are related to the shallow embedding by permafrost and to the activity of cryogenic processes; these soils also have specific features related to soil salinization on seashores against the background of the activity of cryogenesis and soil waterlogging. | Approaches to the Classification of Soils of the Accumulative Seashores of Russian Northeast | 10.1134/S1064229322010057 |
2022-01-01 | Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more sustainable metal cutting fluids and delivery systems, like vegetable oils that are delivered in small aerosol droplets, i.e., via minimum quantity lubrication (MQL). Since the volume of the cutting fluid in MQL is small, the cooling capacity of MQL is not optimal. In order to improve the cooling capacity of the MQL, the spray can be subcooled using liquid nitrogen. This paper investigates subcooled MQL with machining simulations and experiments. The simulations provide complementary information to the experiments, which would be otherwise difficult to obtain, e.g., thermal behavior in the tool-chip contact and residual strains on the workpiece surface. The cBN hard turning simulations and experiments are done for powder-based Cr-Mo-V tool steel, Uddeholm Vanadis 8 using MQL subcooled to −10 °C and regular MQL at room temperature. The cutting forces and tool wear are measured from the experiments that are used as the calibration factor for the simulations. After calibration, the simulations are used to evaluate the thermal effects of the subcooled MQL, and the surface residual strains on the workpiece. The simulations are in good agreement with the experiments in terms of chip morphology and cutting forces. The cutting experiments and simulations show that there is only a small difference between the subcooled MQL and regular MQL regarding the wear behavior, cutting forces, or process temperatures. The simulations predict substantial residual plastic strain on the workpiece surface after machining. The surface deformations are shown to have significant effect on the simulated cutting forces after the initial tool pass, an outcome that has major implications for inverse material modeling. | Evaluation of subcooled MQL in cBN hard turning of powder-based Cr-Mo-V tool steel using simulations and experiments | 10.1007/s00170-021-07901-x |
2022-01-01 | The influence of a new combined technology of material processing - cryogenic laser shock processing (CLSP) on the residual stresses and microhardness that occur in aluminum alloys 2024-T351, is investigated. Parts from this alloy are widely used in agricultural engineering. The residual stresses that occur in the test sample when using various treatment technologies were studied. The results obtained showed that cryogenic treatment (CT) can improve the strengthening effect obtained by classical laser shock processing (LSP). It is shown that the combined processing technology - preliminary 4-h cryogenic treatment (CT) of the test material, and then LSP (the so-called CLSP-4 technology) provides a higher microhardness of the surface, as well as creates stronger fields of compressive residual stresses. It is shown that the surface microhardness and compressive residual stresses of the sample at CLSP-4 were increased by 22.84% and 34.81%, respectively, in comparison with the classical LSP. | Strengthening of Agricultural Machinery Parts by Cryogenic Laser Shock Processing Technology | 10.1007/978-3-031-03877-8_24 |
2022-01-01 | Schappler, Moritz Jahn, Philipp Raatz, Annika Ortmaier, Tobias The combined structural and dimensional synthesis is a tool for finding the robot structure that is suited best for a given task by means of global optimization. The handling task in cryogenic environments gives strong constraints on the robot synthesis, which are translated by an engineering design step into the combined synthesis algorithm. This allows to reduce the effort of the combined synthesis, which provides concepts for alternative robot designs and indications on how to modify the existing design prototype, a linear Delta robot with flexure hinges. Promising design candidates are the 3 P RRU and 3 P RUR, which outperform the linear Delta (3 P UU) regarding necessary actuator force. | Combined Structural and Dimensional Synthesis of a Parallel Robot for Cryogenic Handling Tasks | 10.1007/978-3-030-74032-0_6 |
2022-01-01 | This paper provides a brief overview and results of conducted studies on the increasing wear resistance and durability of heavy-duty machines in different branches of industry. The proposed approach is based on the Deep Cryogenic Treatment (DCT) of parts made of alloy steel. Although this physical phenomenon has been known for ages, it still has contradictory opinions among practitioners and therefore is not widely used. In our studies, technological schedules and corresponding cryogenic equipment were developed and tested. It was shown that DCT is not substitutive but a complementary stage of the standard heat treatment procedures. In distinction from different surface hardening technologies, DCT has a permanent effect on the whole volume of parts. Wear reduction is achieved due to a complete transformation of retained austenite to martensite as well as fine carbides precipitation at the sub-zero temperature range. Additional effects are stress release and hardness homogenisation over the whole large-scale parts subjected to DCT. Particular features of this technology are considered as a time of parts holding at cryogenic temperatures, preferable cooling medium, heating/cooling rates. Recommendations are given for successful DCT implementation in the mining industry depending on steel chemical composition and pre-treatment quenching schedules. | Increasing the Durability of Critical Parts in Heavy-Duty Industrial Machines by Deep Cryogenic Treatment | 10.1007/978-3-030-97822-8_14 |
2022-01-01 | In steels, the conversion of austenite to a harder martensite phase, starts with a well-defined martensite start (Ms) temperature and finishes with martensite finish (Mf) temperatures. When the Mf or even Ms Temperatures are lower than the ambient, the steel may undergo a partial transformation to martensite, while the remaining structure being austenite, christened as retained austenite (RA). Mf is below room temperature in steels containing more than 0.30% C. Significant amounts of retained austenite, may be present, intermingled with martensite at room temperature. Under the influence of mechanical stresses, a gradual transition of RA can take place in material which in turn results in volume change and more importantly affect the dimensional stability of components made out of it. Such kind of instability can lead to catastrophic failure and is not welcomed in space applications. To reduce the retained austenite content, shallow as well as deep cryogenic treatments were proposed on steels in austenite martensite class which is used for space applications. Low temperature treatments were carried along with the conventional heat treatment cycles. Apart from the low temperature, there are many other parameters like socking time, tempering temperature, and time that has a significant influence on the transition of retained austenite to secondary martensite. 07X16H6 steel which belongs to the transition class was subjected to study was given both shallow as well as deep cryogenic treatment at − 80 and − 196 °C respectively. The results revealed that the deep cryogenic treatment was suitable for the complete conversion of RA to ensure the dimensional stability of components. Mechanical characterization also revealed that the tensile strength got enhanced after deep cryogenic whereas, affected the impact resistance. | Effect of Low Temperature Treatments on the Stabilization of Transition Class Steel Used in Satellite Launch Vehicles | 10.1007/978-981-16-7787-8_27 |
2022-01-01 | Precision holes in CFRP/Ti/Al stacks are usually machined with reamers. Machining modes should meet the requirements for each stack layer. Titanium alloy is machined at low cutting speeds at which aluminum alloy machining problems arise (low hole accuracy, high roughness, and tool build-up). The aim of the article is to study the influence of cooling methods, including the cryogenic one, on the surface quality and hole accuracy in a mixed stack containing aluminum alloy layers. The holes were drilled using the Atlas Copco PFD-1500 machine. The MAPAL built-up reamer 14 mm in diameter with carbide inserts was used for cutting. During the experiment, the reaming process was carried out on various stacks without cooling, with air cooling, and with CO_2 cooling. The output data were as follows: deviation from the nominal diameter of the hole in the aluminum alloy, roughness Ra in the aluminum alloy, maximum cutting temperature during reaming, and front surface build-up height after the tool leaves the aluminum alloy layer. Models of the multivariate regression analysis that describe the influence of cooling methods on the quality of holes were built. The use of cooling with liquefied CO_2 improved the hole accuracy for complex multicomponent stacks of metals and composite materials. The surface quality of the holes did not deteriorate. It was similar to the surface quality when cooling with compressed air. | A Study of Cryogenic Cooling When Reaming Holes in CFRP/Ti/Al Stacks | 10.1007/978-3-030-85230-6_77 |
2022-01-01 | Instead of conventional cooling products like oil-based coolants, liquid nitrogen is increasingly used in manufacturing processes for environmental considerations. The main purpose of this study is to examine the impact of deep rolling (DR) under cryogenic cooling on the surface integrity (grain size, phase changes, microhardness and residual stresses) of the AISI 304L metastable austenitic stainless steel. A set of experiments was performed to evaluate the effect of the DR tool depth of penetration (DoP) on the microstructural modifications of the treated material. The enhancement of surface integrity is mainly favored by DR conditions using high depth of penetration. Major findings of this work exhibit that, after cryogenic DR, surface microhardness increases by about 153% at a DoP of 0.16 mm. This is explained mainly by the grain refinement in the near-surface regions and also the formation of 62% volume fraction of strain-induced martensite. It was found that the DR-affected layer thickness increases with the increase of DoP and reaches up to 56 µm. Moreover, high compressive residual stress level of -1181 MPa is introduced at the surface. It was also concluded that the surface integrity modifications strongly depend on the cryogenic DR parameters and particularly the tool DoP, which is investigated in this study. | Deep Rolled Surface Improvement of the AISI 304L Using Cryogenic Cooling | 10.1007/978-3-030-86446-0_32 |
2021-12-31 | Hydrogen, as a space propellant, plays an important role in future space energy systems. However, it is sensitive to heat leakage from the environment because of its low boiling point and small density. Besides, the buoyancy convection is weakened and even completely suppressed in space microgravity environment. When there is heat leakage on the wall of the propellant tank, temperature stratification will be produced around the heat leakage source, resulting in propellant overheating. This will affect the interfacial heat and mass transfer, leading to pressure rise in the tank, and even endanger the structural safety of the system. To prevent tank pressure from rising above its design limits, venting or active pressure control techniques must be implemented. The cryogenic jet mixing is an effective method to suppress temperature stratification. The cryogenic fluid is mixed with the fluid inside the tank through a jet nozzle to reduce the thermal stratification and achieve uniform temperature distribution. In the present study, the temperature stratification phenomenon caused by heat leakage and its destratification via a cryogenic jet under microgravity condition were numerically investigated in the context of a partially liquid-filled large scale model tank. The effects of cryogenic jet mixing on the elimination of temperature stratification were analyzed for different initial filling ratios and mass flow rates. The results show that a higher incident mass flow rate can effectively destroy the temperature stratification inside the tank and promote an inside fluid flow for a given liquid filling ratio. A smaller filling ratio results in a faster growth in both average temperature and average pressure, and a larger amount of mass transfer inside the tank. It is more efficient to implement the cryogenic jet injection in the early stage when the remained propellant is still abundant, or adopt a higher incident mass flow rate to suppress the thermal stratification in the tank. | On the Space Thermal Destratification in a Partially Filled Hydrogen Propellant Tank by Jet Injection | 10.1007/s12217-021-09923-2 |
2021-12-01 | Cutting fluid plays a cooling-lubrication role in the cutting of metal materials. However, the substantial usage of cutting fluid in traditional flood machining seriously pollutes the environment and threatens the health of workers. Environmental machining technologies, such as dry cutting, minimum quantity lubrication (MQL), and cryogenic cooling technology, have been used as substitute for flood machining. However, the insufficient cooling capacity of MQL with normal-temperature compressed gas and the lack of lubricating performance of cryogenic cooling technology limit their industrial application. The technical bottleneck of mechanical—thermal damage of difficult-to-cut materials in aerospace and other fields can be solved by combining cryogenic medium and MQL. The latest progress of cryogenic minimum quantity lubrication (CMQL) technology is reviewed in this paper, and the key scientific issues in the research achievements of CMQL are clarified. First, the application forms and process characteristics of CMQL devices in turning, milling, and grinding are systematically summarized from traditional settings to innovative design. Second, the cooling-lubrication mechanism of CMQL and its influence mechanism on material hardness, cutting force, tool wear, and workpiece surface quality in cutting are extensively revealed. The effects of CMQL are systematically analyzed based on its mechanism and application form. Results show that the application effect of CMQL is better than that of cryogenic technology or MQL alone. Finally, the prospect, which provides basis and support for engineering application and development of CMQL technology, is introduced considering the limitations of CMQL. | Cryogenic minimum quantity lubrication machining: from mechanism to application | 10.1007/s11465-021-0654-2 |
2021-12-01 | In this study, the surface integrity of nickel-titanium (NiTi) shape memory alloys (SMAs) was investigated after face milling processes with cryogenically treated/untreated cemented carbide cutting tools at the conditions of dry cutting and minimum quantity lubrication (MQL) of cutting fluids depending on the changing cutting parameters. The integrity of surface layer of the workpiece material was evaluated according to the mean surface roughness, microstructure and hardness, as well as according to the resultant cutting force and flank wear of inserts. Cutting tests were carried out at three different cutting speeds (20, 35 and 50 m/min), feed rates (0.03, 0.07 and 0.14 mm/tooth) and a constant axial cutting depth (0.7 mm). The influence of these parameters on the surface integrity was extensively investigated. The face milling tests of NiTi SMA at optimal cutting parameters show that the surface integrity enhanced at a cutting speed of 50 m/min and feed rate of 0.03 mm/tooth using boron-added cutting fluid (EG + %5BX) with deep cryogenic heat treated (− 196 °C) CVD coated S40T grade cutting tool. Under MQL conditions, the minimum mean surface roughness (0.278 µm), resultant cutting force (268.2 N) and flank wear (0.18 mm) were obtained due to the high thermal conductivity and lubrication property of EG + %5BX cutting fluid. The highest hardness values (343 HV) were measured at the zone subjected to the highest deformation, while the lowest one (316 HV) was measured at the zone at the least deformation. | Surface Integrity of NiTi Shape Memory Alloy in Milling with Cryogenic Heat Treated Cutting Tools under Different Cutting Conditions | 10.1007/s11665-021-06095-3 |
2021-12-01 | Heat leakage from cryogenic vessels is an important parameter of thermal insulation performance reflected by product loss in the standard method. Current standards require the cryogenic vessel to be full before testing, which wastes a considerable amount of working medium. If product loss is tested at another liquid level, especially at a low liquid level, the working medium can be significantly saved, but the results of the product loss test are inconsistent and do not reflect the thermal insulation performance correctly. In this study, the heat leakage of the test product loss was analyzed, and the energy equations of the gas and liquid in the cryogenic vessels were established. Based on these equations, the heat leakage absorbed by the product loss can be divided into two parts: latent heat and enthalpy rise. However, enthalpy rise is ignored in the standard method; therefore, the product losses are inconsistent at different liquid levels. The heat leakages were then calculated and compensated by the enthalpy rise at different liquid levels. These heat leakage results are consistent and their errors are below 5.0 %. | Method to evaluate heat leakage of vertical cryogenic vessels at different liquid levels | 10.1007/s12206-021-1142-7 |
2021-12-01 | Abstract Cryogenic forming, a new technology used to manufacture aluminum alloy thin-walled parts, has attracted much attention in recent years. This work presents an experimental and theoretical study of 2024-O aluminum alloy sheet forming limit at cryogenic temperatures and provides an effective method for accurate prediction of forming limit curves (FLCs) at cryogenic temperatures. Uniaxial tensile experiments at different temperatures were carried out between 20 °C and − 196 °C to obtain the constitutive equation of the material at cryogenic temperatures. The Marciniak–Kuczynski (M–K) model was used to predict FLCs at cryogenic and room temperatures. The constitutive equation and yield functions are used in the model. The effects of different yield criteria (Mises, Hill-48, Barlat89, Gotoh, and Yld2000-2d) on the prediction results of FLC are analyzed. These prediction results were verified by the Nakazima test, and it was found that the Yld2000-2d yield criterion is the most accurate for FLC prediction. Finally, the M–K model is combined with this criterion to predict the FLC at different temperatures. It was found that the lower the temperature, the higher the FLC curve and the better the sheet formability, and the increase is more obvious at extremely low temperatures. Graphic Abstract | Experimental and Theoretical Investigation on the Forming Limit of 2024-O Aluminum Alloy Sheet at Cryogenic Temperatures | 10.1007/s12540-020-00922-3 |
2021-12-01 | 为有效读出超导纳米线单光子探测器 (SNSPD) 输出信号, 提出一种基于0.13 μm SiGe BiCMOS工艺的低功耗无电感宽带差分超低温放大器. 为解决缺少超低温器件精确模型的问题, 结合并联—并联反馈和电容耦合超低温放大器结构, 通过详细理论分析和仿真, 确定了放大器增益与电路可调设计参数间的关系, 提高了设计和优化的灵活性, 从而实现所需增益. 为实现工作频率范围内端口阻抗平坦特性, 采用RC并联补偿结构, 有效提高了放大器闭环稳定性, 并可抑制放大器过冲问题. 给出室温 (300 K) 和低温 (4.2 K) 下 S 参数和瞬态性能测试结果. 在良好输入输出阻抗匹配下, 该放大器在300 K温度下3 dB带宽为1.13 GHz, 增益为21 dB. 在4.2 K温度下, 该放大器增益可在15~24 dB范围内调节, 其3 dB带宽为120 kHz~1.3 GHz, 功耗仅3.1 mW. 去除芯片外围焊盘, 该超低温放大器芯片核心面积仅为0.073 mm^2. We present a low-power inductorless wideband differential cryogenic amplifier using a 0.13-µm SiGe BiCMOS process for a superconducting nanowire single-photon detector (SNSPD). With a shunt-shunt feedback and capacitive coupling structure, theoretical analysis and simulations were undertaken, highlighting the relationship of the amplifier gain with the tunable design parameters of the circuit. In this way, the design and optimization flexibility can be increased, and a required gain can be achieved even without an accurate cryogenic device model. To realize a flat terminal impedance over the frequency of interest, an RC shunt compensation structure was employed, improving the amplifier’s closed-loop stability and suppressing the amplifier overshoot. The S -parameters and transient performance were measured at room temperature (300 K) and cryogenic temperature (4.2 K). With good input and output matching, the measurement results showed that the amplifier achieved a 21-dB gain with a 3-dB bandwidth of 1.13 GHz at 300 K. At 4.2 K, the gain of the amplifier can be tuned from 15 to 24 dB, achieving a 3-dB bandwidth spanning from 120 kHz to 1.3 GHz and consuming only 3.1 mW. Excluding the chip pads, the amplifier chip core area was only about 0.073 mm^2. | Wideband cryogenic amplifier for a superconducting nanowire single-photon detector | 10.1631/FITEE.2100525 |
2021-12-01 | Abstract This paper examines the effect of planted spruce ( Picea obovata Ledeb.) stands on changes in the morphological characteristics, composition, and properties of cryogenic meadow–chernozem soils that formed in a cryoarid climate under meadow–steppe vegetation in the vicinity of the City of Yakutsk, the central part of the Sakha (Yakutia) Republic. It is shown that the initial morphological profile of the virgin soil (Wca–AUca–ABca–BCA–BCca–Cca) has been transformed over a 45-year exposure period into the profile of a forest humus–calcareous soil (O–OH–AJ–ABca–BCA–BC–Cca). The morphological structure of the virgin soil underwent the following changes: the forest litter (O) and litter–humus (OH) horizons formed; the thickness of the seasonally thawing layer decreased from 123 to 102 cm; and the 10% HCl effervescence depth, which indicates the presence of mobile carbonates (CaCO_3 and MgCO_3) in the soil, increased to 26 cm from the surface. In addition to the morphology, the composition and properties of the humus–calcareous soil have also changed significantly in comparison with the initial meadow–chernozem soil. The pH values of soil–water extracts from the AJ and ABca horizons of the humus–calcareous soil decreased by 1.0–0.7, respectively. The total amount of exchangeable bases (Ca^+2 and Mg^+2) increased in the 0-to 100-cm layer of the forest soil by 1.2 times in comparison with the meadow–steppe soil; the total salt content increased by 1.5 times; and the total N content and organic C content increased by 3.2 and 1.7 times, respectively. Concurrently, the amount of mobile carbonates in the secondary soil decreased by 2.9 times. The magnetic and salt profiles of the studied soils, as well as their salinization degrees and chemistry, have also changed, and the initial cryogenic–exudational water regime has been transformed into a permafrost, periodically-percolative regime due to the change in the vegetation growing on the studied soils. | Changes in the Properties of Cryogenic Meadow–Chernozem Soils in the Central Part of the Sakha Republic under the Influence of Planted Spruce Stands | 10.1134/S1995425521070052 |
2021-12-01 | Electron microscopy (EM) reveals cellular ultrastructure at high definition but faces the challenges of identification of specific subcellular structures and localization of specific macromolecules, whereas fluorescence microscopy (FM) can label and localize specific molecules in cells. Correlative light and electron microscopy (CLEM) combines the advantages of both microscopic techniques. Imaging vitreous hydrated samples at cryogenic temperatures using CLEM enables observations of cellular components of interest and their cellular context in a near-native state. This cryo-CLEM approach is further strengthened by incorporation of superresolution fluorescence microscopy, which can precisely pinpoint targets on electron micrographs. Cryogenic superresolution correlative light and electron microscopy (csCLEM) is an emerging and promising imaging technique that is expected to unveil its full power in ultrastructural studies. The present review describes the logic and principles behind this technique, how the method is implemented, the prospects, and the challenges. | Cryogenic superresolution correlative light and electron microscopy on the frontier of subcellular imaging | 10.1007/s12551-021-00851-4 |
2021-12-01 | Residual stress developed after the quenching of aluminum alloys causes distortion during subsequent machining. The purpose of this study was to reduce the residual stress and improve mechanical properties by using a novel cryogenic treatment in an aluminum alloy, specifically, grade 2A12. The orthogonal test and relevant range analysis method were used to optimize cryogenic treatment parameters for improved distribution of residual stress in 2A12 alloy samples. The changes of microstructure were examined by scanning electron microscopy and transmission electron microscope. It was found that the residual stress in 2A12 alloy could be reduced up to 93%, by optimizing the cryogenic treatment parameters, and the reduction was mainly from grain refinement and uniformly distributed S' precipitates ascribing to the cryogenic treatment. The S' precipitates (Al_2CuMg) were linked to the formation of Cu-Mg co-clusters, which were broadly equiaxed with no internal order. | Optimization of Cryogenic Treatment Parameters for the Minimum Residual Stress | 10.1007/s11665-021-06136-x |
2021-12-01 | 煤矿酸性废水(AMD)被动处理基于自然过程中和废水酸性和去除溶解态金属污染物。在一些情况下,即使没有人类干预,自然过程也可能建立去除酸性废水(AMD)有害成分(如酸度,溶解性铁,铝和锰)的微生物群落。为更好了解这一有益过程如何建立,我们研究了俄亥俄州东部的Huff Run系统,Huff Run的部分河段被人为改道,防止酸性废水(AMD)直接汇入河流。目前,有两个废弃河段接收未处理的煤矿酸性废水(AMD);我们假设增加酸性废水(AMD)在废弃河段驻留时间,可减小酸性废水(AMD)对Huff Run影响。跟踪了两个废弃河段(Farr和Lyons)的水化学和微生物季节性变化。当酸性废水(AMD)穿过河段Farr时,废水铁,铝和锰被部分去除,水呈净碱性,含有丰富的芽孢杆菌和多粘类芽孢杆菌进化型。当废水穿过河段Lyons时,仅溶解性铁被部分去除,由于脂环酸芽孢杆菌作用,沉积物含有丰富进化型,它们能够在酸性条件下使铁(II)氧化沉淀;而铝和锰未被去除。研究结果表明,延长煤矿酸性废水(AMD)在废弃河段内滞留时间可以去除废水金属污染物,而且渠道中发生的非生物和生物反应也受汇入废水化学性质的影响。 Im Bereich der Zyanidhalde der Darasun-Erzmine wurden geo¬chemi¬sche und geophysikalische Untersuchungen durchgeführt. Die Lagerstätte befin¬det sich in einer Permafrostregion. Die Abraumhalden enthalten bis zu 40 Massen-% Pyrit und 5,7 Massen-% Arsenopyrit. Der Zweck der vor-liegenden Untersuchung war die Bestimmung der Zusammensetzung und der Einblick in die Umwandlungsprozesse in den Tailings sowie der Arsen-, Gold-, Silber-, Beryllium und Thallium-Spezies in den Dränage-wässern und im Wasser des Darasun-Flusses vor und nach der Vermischung mit den Ab¬flüssen aus dem Bergbaugebiet. Wenn der Abraum aufgrund des zykli¬schen jahreszeitlich bedingten Zufrierens und Auftauens des Wassers durch den Kontakt mit dem Luft- und gelösten Sauerstoff oxidiert wird, werden drei Gruppen von chemischen Elementen freigesetzt: Typische Erzmetalle und Verunreinigungen (Blei, Kobalt, Nickel, Zink, Cadmium, Eisen, Aluminium, Thallium, Beryllium, Indium), Edelmetalle und Metalloide (Gold, Silber, Kupfer, Arsen, Antimon, Selen) und Übergangsmetalle und -metalloide (Wismut, Zinn, Tellur). Das Dränagewasser hat einen Salzgehalt bis 5 g/L, Sulfationen¬konzen-tation bis 2 g/L und Zyanidkonzentrationen bis 4 g/L. Weiterhin weisen sie hohe Konzentrationen an Gold (bis 130 µg/L), Silber (bis 3,8 µg/L), Arsen (bis 350 µg/L) und Antimon (bis 1.100 µg/L) sowie Verunreinigungen an Thallium, Indium, Beryllium und Wismut auf. Das Dränagewasser gelangt in den Darasun-Fluss. Die dadurch hervorgerufenen hydrochemischen Anomalien sind noch in einer Entfernung von mehreren zehn Kilometern im Unterstrom nachweisbar. Se han realizado investigaciones geoquímicas y geofísicas en una zona del depósito de residuos del proceso de cianuración del mineral de Darasun, que se encuentra en una región de permafrost. Los residuos contienen hasta un 40 % en peso de pirita y un 5,7 % en peso de arsenopirita. El objetivo de este trabajo fue determinar la composición y los mecanismos de transformación de los relaves y las especies de As, Au, Ag, Be y Tl presentes en las aguas de drenaje y en las aguas del río Darasun, antes y después de la mezcla con los flujos tecnogénicos de la zona minera. Cuando los residuos se oxidan con el oxígeno del aire y del agua debido a la repetida congelación y descongelación estacional del agua, se lixivian tres grupos de elementos químicos: los metales típicos de la mena y los elementos de impureza (Pb-Co-Ni-Zn-Cd-Fe-Al-Tl-Be -In), los metales nobles y los metaloides (Au-Ag-Cu-As-Sb-Se), y los metales y metaloides de post-transición (Bi-Sn-Te). Se forman aguas de drenaje con una salinidad de hasta 5 g/L, con concentraciones de iones sulfato de hasta 2 g/L y concentraciones de cianuro de hasta 4 g/L, altas concentraciones de Au (hasta 130 µg/L), Ag (3,8 µg/L), As (hasta 350 µg/L) y Sb (hasta 1100 µg/L) y otros elementos en concentraciones de impureza (Tl, In, Be y Bi). Las aguas de drenaje desembocan en el río Darasun, lo que provoca la formación de anomalías hidroquímicas a una distancia de decenas de kilómetros de los residuos. Geochemical and geophysical investigations were performed in an area of the Darasun ore cyanidation tailings impoundment, which is located in a permafrost region. The tailings contain up to 40 wt% pyrite and 5.7 wt% arsenopyrite. The purpose of this work was to determine the composition and mechanisms of transformation of the tailings and species of As, Au, Ag, Be, and Tl in drainage waters and the Darasun River before and after mixing with technogenic flows from the mining area. When the waste is oxidized because of the repeated seasonal freezing and thawing of water, three groups of chemical elements are leached: typical ore metals and impurity elements (Pb–Co–Ni–Zn–Cd and Fe–Al–Tl–Be–In), noble metals, metalloids (Au–Ag–Cu–As–Sb–Se), and post-transition metals and metalloids (Bi–Sn–Te). Drainage waters with salinities up to 5 g/L form, with concentrations of sulfate ions up to 2 g/L and cyanide up to 4 g/L, high concentrations of Au (up to 130 µg/L), Ag (3.8 µg/L), As (up to 350 µg/L), and Sb (up to 1100 µg/L), and impurity elements (Tl, In, Be, and Bi). The drainage water flows into the Darasun River, resulting in hydrochemical anomalies tens of kilometers downstream. | Cyanides, Arsenic, and Noble Metals in Abandoned Gold Ore Cyanidation Tailings and Surface Waters in a Permafrost Region (Transbaikal Territory, Russia) | 10.1007/s10230-021-00828-5 |
2021-12-01 | Abstract The effect of a new combined technology of cryogenic laser shock processing on the mechanical characteristics of the 2024-T351 aluminum alloy is studied. We study the microhardness and residual stresses occurring in a test sample by using various processing technologies. The results show that cryogenic processing can enhance the effect of hardening achieved by conventional laser shock processing. We show that the combined processing technology consisting of cryogenic treatment of the material for four hours and subsequent conventional laser shock processing yields a higher microhardness of the surface and produces stronger fields of compressive residual stresses. | Features of Using Cryogenic Laser Shock Processing for Hardening of 2024-T351 Aluminum Alloys | 10.3103/S1052618821090119 |
2021-12-01 | The effects of deep rolling parameters, particularly, work speed and cooling conditions (dry and cryogenic) on the surface integrity of AISI 304L machined samples and their further impact on uniform and localized corrosion behavior in chloride environment were experimentally investigated in this work. The electrochemical behavior of machined and deep rolled samples was assessed using cyclic potentiodynamic polarization tests in synthetic seawater. It was found that the corrosion behavior of AISI 304L deep rolled components is related to combined factors: surface roughness, recrystallized grains, strain-induced martensite, microhardness and residual stresses. Findings of this study exhibit that grain refinement generated in the surface layers leads to improved corrosion behavior of deep rolled specimens with regard to machining state. In addition, samples deep rolled at a speed of 25 m/min, without cooling, showed better corrosion resistance than those processed under cryogenic cooling. However, the application of cryogenic deep rolling at speeds of 75 and 120 m/min significantly enhanced the electrochemical behavior of mechanically treated specimens. Despite of high amounts of strain-induced martensite that can deteriorate the electrochemical behavior, it was shown that specimens deep rolled under these conditions, presenting better surface characteristics, depicted an improved corrosion resistance. | Improvement of the corrosion behavior of AISI 304L stainless steel by deep rolling treatment under cryogenic cooling | 10.1007/s00170-021-07744-6 |
2021-12-01 | Abstract— Laser shock wave processing is an innovative technology of material hardening and is considered as an alternative to the well-known shot blasting hardening. The aluminum alloy (2024-T351) is studied. This technology is based on the occurrence of compressive residual stresses in subsurface layers of the processed metal alloys aimed at improvement of their fatigue strength as well as corrosion wear resistance. Since laser pulses generated by high intensive laser facilities cover only a minor area of the surface processed, the processing is carried out by overlapping of laser spots. In order to cover the processed surface completely, scanning is performed according to a zigzag pattern. Such zigzag scanning is the simplest and is easily feasible; however, it has a significant side effect: the residual stresses are characterized by obviously expressed anisotropy. This article is aimed at development of a numerical model allowing us to describe and to explain the influence of the scanning direction on the tensor of residual stresses. As an efficient solution to reduction of the aforementioned anisotropy of residual stresses, it is proposed to scan surfaces in random sequence instead of a conventional zigzag pattern. As the second method to reduce the anisotropy of residual stresses, it is proposed to apply the so-called cryogenic laser shock wave processing. It has been demonstrated that the cryogenic temperature during the cryogenic laser shock wave processing can increase the dislocation density significantly, thus promoting further grain disintegration and improvement of the mechanical properties of the 2024-T351 aluminum alloy, as well as efficient elimination of anisotropy of residual stresses. | Anisotropy of Residual Stresses Occurring upon Laser Shock Processing of the 2024-T351 Aluminum Alloy and Ways to Reduce It | 10.3103/S1052618821080112 |
2021-12-01 | In recent years, composites have attracted a great deal of interest because they lack the limitations of metallic and polymer materials. Although carbon-fiber- reinforced plastics (CFRPs) of the various composites exhibit superior properties, this machining has been challenging because the materials are anisotropic and non-homogeneous. The machining characteristics of CFRPs have been studied for over a decade. Recent studies have used advanced machining techniques to increase productivity and quality. Developments in sensing and computing technologies have been exploited to derive monitoring and diagnostic systems based on artificial intelligence. Although several reviews of CFRP machining have been published, they focused on predictive models or experimental studies on machining mechanisms and characteristics. Here, we review the current state-of-the-art research on advanced technologies and monitoring systems to guide future studies. | Recent Developments and Challenges on Machining of Carbon Fiber Reinforced Polymer Composite Laminates | 10.1007/s12541-021-00596-w |
2021-11-01 | Three process flow diagrams of vacuum insulated cryogenic double-walled LNG storage tanks are analyzed. The aim of the research is to exclude the spillage of liquid to the external environment in case of breaches to the integrity of the inner vessel, allowing an expensive fire protection system to be avoided. It is shown that the most promising scheme involves a double-walled storage tank with a bypass device to retain of the LNG liquid phase in the annular space at leak diameters up to 100 mm. | Process Flow Diagrams of Cryogenic Double-Wall Tanks for LNG Storage | 10.1007/s10556-021-00975-0 |
2021-11-01 | Many geotechnical engineering problems in the cold region, including cracking of pavements, damage to the foundations of structures, and fracture of pipelines are blamed due to the deformation and failure of frozen soils. In this study, cryogenic suction is used as one of the constitutive variables together with the solid-phase stress to model the joint influence of temperature and confining pressure on the constitutive behaviour of frozen soils. A nonlinear relationship is proposed to link cryogenic cohesion with cryogenic suction, to consider the strength increase due to the lowering of temperature. In the space of the solid-phase stress and cryogenic suction, loading-collapse yield surface, subloading surface, and unified hardening parameter are then integrated to produce a novel multisurface constitutive model for frozen soil. The proposed model can predict the mechanical behaviours such as softening/hardening and dilation/compression of frozen soil under various temperatures and stresses. Some special characteristics of frozen soil, including the deformation induced by ice segregation and softening related to pressure melting, can also be well explained by this model. The developed model is validated by using several triaxial compression test results of different frozen soils in the literature. | A multisurface elastoplastic model for frozen soil | 10.1007/s11440-021-01391-7 |
2021-10-01 | In this study, effect of cryogenic heat treatment in polycrystalline Co_38Ni_37Al_17Si_6Sb_2 ferromagnetic shape memory alloy (FSMA) on phase formation phenomenon was investigated. After the homogenization process, the synthesized Co_38Ni_37Al_17Si_6Sb_2 alloy was cooled into liquid nitrogen and kept in liquid nitrogen for different time periods. X-ray difraction method was used to determine lattice parameters and crystallite sizes from the samples obtained. The crystallite size of the Co_38Ni_37Al_17Si_6Sb_2 alloy was calculated using the Debye Scherrer equation. The results show that these alloys were composed of four phases; A1 structure of γ phase, β austenite phase (B2 cubic), body-centered tetragonal L 1_0 martensite and γ ′ (ordered fcc L 1_2) phase. Thermal properties of Co_38Ni_37Al_17Si_6Sb_2 specimens were analyzed by Differential Scanning Calorimetry (DSC). Martensitic transformation temperatures were increased due to the increasing aging time in Liquid Nityrogen. An endothermic peak at ~ 165°C and an exothermic peak at ~ 110°C were observed from DSC results. Scattering Electron Microscope (SEM) and optical microscope experiments were performed to investigate metallographic structures. The findings of the γ , β and L 1_0 phases were confirmed by SEM observations and EDS analysis. As a result of cryogenic heat treatment in the material phase formation phonomenon was discussed. Vickers and Rocwell Hardness methods were determined to find differences of hardness values due to the cryogenic heat treatment time on Co_38Ni_37Al_17Si_6Sb_2 FSMA. The hardness value of the alloy has been found to rise with increasing cryogenic aging time. | Effect of Cryogenic Heat Treatment on Phase Formation in Co_38Ni_37Al_17Si_6Sb_2 Ferromagnetic Shape Memory Alloy | 10.1007/s11665-021-05930-x |
2021-10-01 | Although Inconel 718 is an important material for modern aircraft and aerospace, it is a kind material, which is known to have low machinability. Especially, while these types of materials are machined, high cutting temperatures, BUE on cutting tool, high cutting forces, and work hardening occur. Therefore, in recent years, instead of producing new cutting tools that can withstand these difficult conditions, cryogenic process, which is a heat treatment method to increase the wear resistance and hardness of the cutting tool, has been applied. In this experimental study, feed force, surface roughness, vibration, cutting tool wear, hardness, and abrasive wear values that occurred as a result of milling of Inconel 718 material by means of cryogenically treated and untreated cutting tools were investigated. Three different cutting speeds (35-45-55 m/min) and three different feed rates (0.02-0.03-0.04 mm/tooth) at constant depth of cut (0.2 mm) were used as cutting parameters in the experiments. As a result of the experiments, lower feed forces, surface roughness, vibration, and cutting tool wear were obtained with cryogenically treated cutting tools. As the feed rate and cutting speed were increased, it was seen that surface roughness, vibration, and feed force values increased. At the end of the experiments, it was established that there was a significant relation between vibration and surface roughness. However, there appeared an inverse proportion between abrasive wear and hardness values. While BUE did not occur during cryogenically treated cutting tools, it was observed that BUE occurred in cutting tools which were not cryogenically treated. Also, in this study, the statistical validity of the experimental values was tested with the help of second-order equations and analyses of variance (ANOVA). R ^2 values obtained as 99.14%, 99.76%, and 97.98% for vibration, surface roughness, and feed force values were modeled statistically with the help of second-order equations, respectively. | Milling Inconel 718 workpiece with cryogenically treated and untreated cutting tools | 10.1007/s00170-021-07688-x |
2021-10-01 | Abstract The paper presents the tasks and study technique dedicated to fretting wear of air foil bearings of cryogenic turbomachines under internal and external vibrations as well as fretting wear test unit for air foil bearings. | Fretting Wear of Cryogenic Turbomachine Bearings for Superconductive Power Plants | 10.3103/S1068799821040176 |
2021-10-01 | Abstract Stainless steels with Fe/Cr/Ni ratios of 74/18/8, 71/17/12, and 55/20/25 were produced from elemental powders by high energy mechanical alloying at both room and cryogenic temperatures. The effect of mechanical alloying temperature on martensitic transformation, the reversion of deformation-induced martensite-to-austenite upon annealing, and the influence of cooling rate on the thermal stability of reversed austenite upon cooling to room temperature were investigated in detail by in-situ and ex-situ X-ray diffraction (XRD) experiments, transmission electron microscopy (TEM) and Thermo-Calc simulations. A relative comparison of stainless steels after room temperature mechanical alloying indicated that the low nickel-containing steel underwent an almost complete martensitic transformation. However, martensitic transformation by deformation through mechanical alloying at room temperature would not be possible with increasing nickel contents but was created partially at cryogenic temperature, the degree of which depended on the steel composition. The in-situ XRD studies exhibited that the deformation-induced martensite completely transformed to austenite at elevated temperatures. The complete reverse transformation temperature simulated by Thermo-Calc software was found to be lower than that of the experimentally determined ones. Additionally, the different cooling rates from the reversed austenite demonstrated that the slower cooling increased the thermal stability of reversed austenite at room temperature. Graphic Abstract | Effect of Composition, Mechanical Alloying Temperature and Cooling Rate on Martensitic Transformation and Its Reversion in Mechanically Alloyed Stainless Steels | 10.1007/s12540-020-00866-8 |
2021-10-01 | Abstract The analysis tools for the process of nitrogen aircraft supplying under various modes of flight intensity as a part of realistic scenarios is developed and substantiated by the methods of simulation models. Regression relations are proposed by the least squares to describe the logistic forecasting of the aerodrome nitrogen supply. A volume of backup storage is determined that is capable to meet the airfield requirements and for how long in the case of one air separation plant operation and various average values of departing aircraft. | Logistic Forecasting of Aircraft Nitrogen-Charging Service of Air Units in Peacetime and in Wartime | 10.3103/S1068799821040048 |
2021-09-15 | In the present work, investigation of structural evolution of Cu_33Zr_67 specimen during the cooling process from 2500 down to the 300 K, 200 K, 150 K, 100 K, 50 K, and 10 K has been performed at cooling rate of 5 K/ps using molecular dynamics simulation. The pair distribution function (PDF) reveals that Zr‒Zr pair causes the splitting of the first peak of the Cu_33Zr_67 glass at a lower temperature with an increase in height. Splitting of the first and second peaks supports the presence of the inhomogeneous structure with a statistical average of crystal-like and disordered structural regions in the Cu_33Zr_67 glass. Voronoi cluster analysis indicated that quasi icosahedral clusters such as < 284 > , < 0285 > , and < 0282 > ; mixed-type cluster such as < 0364 > ; and crystal-like clusters such as < 0446 > are responsible for stabilization of glassy phase at 300 K, 200 K, 150 K, 100 K, 50 K, and 10 K. Similarly, the maximum population of the Cu-centered and Zr-centered < 0286 > quasi icosahedral clusters support the stability of the glassy phase over the studied temperature range. Besides, the maximum population of Cu-centered < 0367 > and Zr-centered < 0364 > , < 0367 > , < 0363 > , and < 0365 > mixed-type clusters and Cu-centered < 0448 > and Zr-centered < 0448 > , < 0445 > , < 0446 > , and < 0444 > crystal-like clusters support the possibility of the presence of intermediate phase of CuZr_2 at lower temperatures as observed from PDFs. Mean square displacement (MSD) for the Cu_33Zr_67 glass shows that the diffusion coefficient of Cu and Zr atoms reduces with decreasing temperature from 300 to 10 K. Diversity parameter (d) was found to decrease with decreasing temperature. | Investigation of structural evolution in the Cu–Zr metallic glass at cryogenic temperatures by using molecular dynamics simulations | 10.1007/s00894-021-04886-y |
2021-09-09 | Scaling of concrete due to salt frost attack is an important durability issue in moderate and cold climates. The actual damage mechanism is still not completely understood. Two recent damage theories—the glue spall theory and the cryogenic suction theory—offer plausible, but conflicting explanations for the salt frost scaling mechanism. The present study deals with the cryogenic suction theory, which assumes that freezing concrete can take up unfrozen brine from a partly frozen deicing solution during salt frost attack. According to the model hypothesis, the resulting saturation of the concrete surface layer intensifies the ice formation in this layer and causes salt frost scaling. In this study an experimental technique was developed that makes it possible to quantify to which extent brine uptake can increase ice formation in hardened cement paste (used as a model material for concrete). The experiments were carried out with low temperature differential scanning calorimetry, where specimens were subjected to freeze–thaw cycles while being in contact with NaCl brine. Results showed that the ice content in the specimens increased with subsequent freeze–thaw cycles due to the brine uptake at temperatures below 0 °C. The ability of the hardened cement paste to bind chlorides from the absorbed brine at the same time affected the freezing/melting behavior of the pore solution and the magnitude of the ice content. | Salt frost attack on concrete: the combined effect of cryogenic suction and chloride binding on ice formation | 10.1617/s11527-021-01779-7 |
2021-09-08 | To further improve the performance of accelerators, the first cryogenic normal-conducting RF gun in China was designed and manufactured. As a new and attractive trend, this optimized cryogenic RF gun can generate a low-emittance beam with a short-driven laser pulse because of its promising high gradient on the cathode. In this paper, optimization of the RF design and beam dynamics, including suppression of the peak RF field and elimination of the multipole mode, is presented. In addition, the emittance growth caused by the alignment deviation and RF jitter is discussed. After the gun was manufactured, a cold test was conducted at both room temperature and cryogenic conditions. At room temperature, the field distribution was obtained by the bead pull method. Under cryogenic conditions, the RF properties, such as the coupling coefficient and quality factor, varied with temperature. The test results agreed with the design. In the cryogenic test, vibration measurements were performed. Without vibration isolation, a maximum vibration of 50 $$\mu \text{m}$$ μ m was observed. These cold test results are the basis of the following high-power test. | Design optimization and cold RF test of a 2.6-cell cryogenic RF gun | 10.1007/s41365-021-00925-8 |
2021-09-01 | Abstract In this paper, we consider global trends in the development of vehicles, indicate the main ways to increase the energy efficiency of conversion technology, consider the possibility of introducing high-temperature superconductivity technologies in power plants of air transport, and present the results of experimental and analytical studies of the conducting properties of field–effect transistors when operating in a liquid nitrogen environment. | Prospects for the Application of HTSC Technologies for the Electric-Power Complex of Vehicles | 10.3103/S1068371221090133 |
2021-09-01 | Background The cryogenic control system of BEPCII has been in stable operation for more than 10 years, providing technical support for the generation of cryogenic environments. The core hardware of the cryogenic control system is composed of PLC and VME controller, and the operating software includes PLC commercial software and EPICS. However, some hardware and software are obsolete. Purpose An upgrade prototype of the cryogenic control system is designed and built to study the compatibility contradiction between software and hardware, and ensure the long-term stable operation of cryogenic system. Method Keep the hardware architecture, upgrade the software and hardware modules of PLC and VME respectively, and test the system compatibility. Conclusion The upgrading prototype of the cryogenic control system solves the problem of software and hardware compatibility, and makes it possible to achieve a seamless and smooth upgrade of the cryogenic control system in the future. | Upgrade design and prototype implementation of cryogenic control system in BEPCII | 10.1007/s41605-021-00263-8 |
2021-09-01 | Abstract A method is described that allows one to reduce the critical current and switching power of a short nanowire from a superconducting state to a normal state by embedding a section of a normal metal into the nanowire. This effect results from the local heating of the superconducting wire due to the heat released in the normal metal. An integrated resistor is created from the original NbN using ion irradiation through a mask. The obtained values of switching powers allow designing multilayer logical elements without galvanic coupling for classical cryo-computers. | Creation of Elements from NbN for Logical Devices of Classical Cryo-Computers | 10.1134/S1063783421090109 |