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2023-07-01 | Due to the annual increase in CO_2 emissions, climate change continues to progress. In order to achieve the goals set in the Paris Climate Agreement, CO_2 capturing measures are necessary in addition to the reduction in carbon dioxide emissions. This review article describes and discusses the CO_2 capturing methods published in the last 20 years. Processes for absorption, gas–solid reaction, adsorption, cryogenic processes, membrane processes and the capture of carbon dioxide with natural inclusion were examined in more detail. | Review: CO_2 capturing methods of the last two decades | 10.1007/s13762-022-04680-0 |
2023-07-01 | The magnetoresistance of GaP_ x As_1− x ( x = 0.4) whiskers with a doping concentration of silicon in the range from the dielectric side of metal-insulated transition (MIT) (~ 10^17 cm^−3) to its critical concentration ( N _ c ~ 5 × 10^18 cm^−3) at cryogenic temperatures of 4.2–77 K and magnetic field induction of 0–14 T was studied. A negative magnetic resistance (NMR) with a maximum value of 7% was found at a temperature of 4.2 K and a magnetic field of 4.5 T, which is dependent on magnetic field induction and current direction. The NMR absolute value reduces with increasing temperature was observed in the transverse and longitudinal magnetoresistance. The nature of the revealed NMR effect was discussed in the studied samples. A similar effect was observed in InSb whiskers. There are four possible reasons for the NMR effect in the GaP_ x As_1− x and InSb whiskers such as dimensional quantization, the magnetic ordering of electron spins or magnetic ordering due to uncontrolled magnetic dopant introduction and quantum interference of the electron wave function. The GaP_ x As_1− x whisker application as the temperature sensor was proposed due to the studied results of the temperature dependence of their conductivity. | Magnetoresistance of GaPAs and InSb whiskers | 10.1007/s13204-022-02596-2 |
2023-07-01 | Cryogenic cooling is an efficient technology to facilitate the machining process of difficult-to-cut materials. Performing this process with nontoxic biocompatible liquid nitrogen is an eco-friendly operation which has recently received much attention due to its promising advantages. In the present work, a comparative study has been performed on the machining process of Ti6Al4V alloy using dry and cryogenic cooling approaches. So, the effect of machining parameters (cutting speed, feed rate, and depth of cut) is investigated on the process temperature and the surface integrity features such as surface roughness, microhardness, and grain size. The results revealed that the cryogenic technology decreases the cutting region temperature by about 30% which means applying less thermal loads on the machining samples. Also, among the process parameters, the feed rate has the greatest effect and the cutting speed has the least effect on the machining temperature. Based on the results, the cryogenic cooling has a successful effect on improving surface quality. It was also discovered that the cryogenic machining increases microhardness and decreases grain size compared to dry machining. | Cryogenic and Dry Machining of Ti6Al4V Alloy for Evaluation of Microhardness, Thermal Loads, Microstructure, and Surface Quality | 10.1007/s11665-022-07512-x |
2023-06-30 | Cryogenic and ultrasonic-assisted turning have both beneficial effects on the machinability of difficult-to-machine materials, such as titanium alloy Ti-6Al-4V. This research investigates the effect of combining both cryogenic and ultrasonic-assisted machining, to assess the effects on cutting temperature, forces and tool wear. The research utilizes FEM and CFD models to provide a better understanding of the interaction between the mechanisms at work during the machining process—namely the ultrasonic motion of the tool and the cryogenic impingement of the tool. The experimentation is then conducted to prove the effectiveness of combining both methods in reducing the cutting forces and reducing tool wear. The combined process is compared to conventional turning, cryogenic turning and ultrasonic-assisted turning. The CFD and FEM results showed a decrease in tool and chip temperature by 7.26% and 13.86%, respectively, when compared to UAT. The cutting forces in the combined turning show a reduction of 22% when compared to conventional turning. Tool wear is analyzed for the 4 cases. Tool wear caused by adhesion is shown to decrease in the new combined cutting method. This research has scientific as well as potential industrial applications in the machining of difficult-to-machine materials. | Advanced Manufacturing of Titanium Alloy Ti-6Al-4V by Combining Cryogenic Machining and Ultrasonic-Assisted Turning | 10.1007/s11665-023-08430-2 |
2023-06-28 | The research studies of e-beam sustained discharge gas lasers initiated by Nikolai Basov in early 1970s made it possible to develop lasers based on the fundamental transitions of carbon monoxide molecule with high laser power and efficiency. Soon, under his scientific supervision, lasing on first-overtone transitions of CO molecule was obtained. Following these results, about ten years ago a compact slab CO laser excited by a repetitively pulsed capacitive RF discharge and cryogenic cooling of its electrodes, operating without forced pumping of its active medium was for the first time developed at the N.G. Basov Quantum Radiophysics Division of the P.N. Lebedev Physical Institute. At present, the average power of such lasers with active medium volume of ~ 35 cm^3 reaches 40 W on CO molecule fundamental transitions (in the wavelength range of 5.06–5.92 μm) and 6 W on first-overtone transitions (λ = 2.60–3.05 μm). Under Q-switching, those repetitively pulsed lasers allow one to obtain laser emission with a peak power up to 5 kW which made it possible to apply them in experiments on laser radiation frequency conversion in nonlinear crystals into the spectral range of ~ 2–20 μm. | R&D of carbon monoxide lasers at the Lebedev physical institute of the Russian academy of sciences (review) | 10.1007/s11082-023-04922-6 |
2023-06-17 | Nickel-based alloys have great application value in aerospace, biomedical industry, chemical industry, and other fields. However, nickel-based alloys are known to be difficult to process, which will generate a lot of heat and friction during processing, which limits the application range of nickel-based alloys. Therefore, a large amount of cutting fluid needs to be used during processing, and the cutting fluid will cause harm to human health and the environment. In order to solve these problems, scholars proposed to use the minimum quantity lubrication (MQL) to replace the conventional flood cooling lubrication technique. Recently, many papers have proposed to use MQL for lubrication /cooling in the processing of nickel-based alloys. However, few studies have approached this topic comprehensively. To bridge this gap, this study conducts a comprehensive literature review of the progress made in the processing of nickel-based alloys using various MQL methods. It should be noted that these studies are divided into four categories: vegetable oil-based MQL, cryogenic cooling-based MQL, solid lubricant-based MQL, and electrostatic atomization-based MQL. It is crucial to compare the advantages of these cooling and lubricating technologies in machining nickel-based alloys, analyze their experimental results, and assess their impact on machining quality and tool wear. This review reveals that compared to traditional MQL, vegetable oil-based MQL is more energy-saving and environmentally friendly, resulting in approximately 30% improvement in surface quality and a 50% reduction in tool wear. The addition of solid lubricants to vegetable oil further enhances its lubrication performance. Cryogenic cooling-based MQL enables the attainment of finer grains and smaller sawtooth chips. Electrostatic atomization MQL, by altering the atomization process of traditional MQL, produces more uniform droplets, leading to a 42.4% reduction in tool wear and a 47% improvement in machined surface quality. The purpose of this paper is to help researchers identify existing gaps and to enable MQL to improve the processing quality and application range of nickel-based alloys. Finally, the present technical challenges and future research directions are put forward. | Minimum quantity lubrication machining nickel base alloy: a comprehensive review | 10.1007/s00170-023-11721-6 |
2023-06-14 | The microwave quantum correlation as a crucial issue in quantum technology is analyzed and studied. An open quantum system operating at 4.2 K is designed in which InP HEMT as the nonlinear component couples two external oscillators. The quantum theory is applied to analyze the system completely. The Lindblad Master equation is used to analyze the time evolution of the expanded closed system that covers the environmental effects. In the following, the state of the system defined is determined in terms of the ensemble average state using the density matrix; then, the ensemble average of the different operators is calculated. Accordingly, the covariance matrix of the quantum system is derived, and the quantum discord as a key quantity to determine the quantum correlation is calculated. As an interesting point, the results show that InP HEMT mixes two coupling oscillator modes so that the quantum correlation is created at different frequency productions, especially the zero-IF band. Nonetheless, the main point is that one can strongly manipulate the quantum correlation in the zero-IF using circuitry engineering. It is established by increasing the operational frequencies in the quantum system leading to dramatically limiting the thermal noise since the zero-IF band remains unchanged. | Enhancing quantum correlation at zero-IF band by confining the thermally excited photons: InP hemt circuitry effect | 10.1007/s11082-023-04850-5 |
2023-06-01 | The effect of deep cryogenic treatment (DCT) on the electrochemical behavior of Ti–6Al–4V alloy in Hank’s solution was experimentally investigated in the present work. Deep cryogenic treatments at − 196 °C soaking for 24 (DCT-24) and 48 (DCT-48) hours were conducted on the commercial annealed Ti–6Al–4V alloy. The methods of polarization and electrochemical impedance spectroscopy (EIS) were employed to evaluate the electrochemical behavior and corrosion mechanism. Furthermore, atomic force microscopy (AFM) was used to detect the corrosion surface. The results showed that deep cryogenic treatment shifted the corrosion potentials ( E _corr) to the positive direction. The corrosion current densities ( i _corr) of samples treated by DCT-24 and DCT-48 decreased from 153.1 nA·cm^−2 in the untreated (UT) sample to 86.3 nA·cm^−2 and 43.3 nA·cm^−2, respectively. Furthermore, the roughness of corrosion surfaces of samples subjected to DCT was smaller than that of the UT sample, which indeed demonstrated the improvement in corrosion resistance of Ti–6Al–4V alloy in Hank’s solution. The results of EIS test indicated that deep cryogenic treatment had no influence on the corrosion mechanism of Ti–6Al–4V alloy in Hank’s, while enhanced resistance value of outer porous layer R _p, which makes the surface more efficient to prevent the corrosion. The reduction of β-phase particles, improvement in dislocation density and release of residual stress caused by deep cryogenic treatment had great contribution to the improvement in corrosion resistance of Ti–6Al–4V alloy in Hank’s solution. | Electrochemical behavior of Ti–6Al–4V alloy in Hank’s solution subjected to deep cryogenic treatment | 10.1007/s12598-018-1163-2 |
2023-06-01 | The mechanical behavior of VCoNi medium-entropy alloys with five different grain sizes at three different temperatures was investigated. The VCoNi alloys with different grain sizes exhibit a traditional strength–ductility trade-off at 77 K, 194 K and 293 K. Both the yield strength and the uniform elongation of the VCoNi alloys with similar grain size increase with decreasing the deformation temperature from 293 to 77 K. Obvious strain hardening rate recovery characterized by an evident up-turn behavior at stage II is observed in VCoNi alloys with the grain size above 11.1 μm. It is found that the extent of the strain hardening rate recovery increases with increasing grain size or decreasing deformation temperature. This may mainly result from the faster increase in the dislocation multiplication rate caused by the decrease in the dislocation mean free path, the decrease in the absorption of dislocations by grain boundaries and the dynamic recovery from the cross-slip with increasing grain size, as well as the suppressed dynamic recovery at cryogenic temperatures. The critical grain sizes for the occurrence of the recovery of strain hardening rate are determined to be around 9.5 μm, 8.3 μm and 3 μm for alloys deformed at 293 K, 194 K and 77 K, respectively. The basic mechanism for the strain hardening behavior of the VCoNi alloys associated with grain size and deformation temperature is analyzed. | Effects of Grain Size and Cryogenic Temperature on the Strain Hardening Behavior of VCoNi Medium-Entropy Alloys | 10.1007/s40195-023-01520-z |
2023-06-01 | Due to an excellent ratio of high strength and low density, Ti-6Al-4V is suitable for many industrial applications, especially in the aerospace industry. However, Ti-6Al-4V is also characterized by a very low thermal conductivity and high chemical reactivity which is why the titanium alloy is considered to be a hard-to-cut material. Machining Ti-6Al-4V leads to high cutting temperatures, which leads to a rapidly progressing thermo-chemical induced tool wear. To reduce the thermal load and to enhance the cutting performance, suitable cooling strategies are a necessity. A novel, highly efficient cooling approach is to apply sub-zero metalworking fluids (MWF) at liquid state but at supply temperatures well below 0 °C. These sub-zero MWF inhibit high cooling effects due to their low supply temperature in superposition with a beneficial wetting behavior. In this work, the application of a sub-zero cooling strategy is investigated when milling Ti-6Al-4V. The influence of both down milling and up milling is investigated under a systematic variation of the cutting speed and feed per tooth. For comparison, the experiments are also conducted using a cryogenic CO_2 cooling. The performance of both cooling strategies in dependence of the milling process is described on the basis of the occurring forces, the resulting tool wear, and the surface quality achieved. The results show that the sub-zero cooling can successfully improve the machinability of Ti-6Al-4V even at elevated cutting parameters and unfavorable cutting conditions. As a result, sub-zero milling clearly outperforms the cryogenic CO_2 cooling, since less tool wear and an overall lower surface roughness are observed. Consequently, when using a sub-zero cooling strategy, higher metal removal rates, longer tool life, and better surface qualities are achievable. | Sub-zero milling of Ti-6Al-4V—impact of the cutting parameters on the resulting forces, tool wear, and surface quality | 10.1007/s00170-023-11334-z |
2023-06-01 | The EDELWEISS collaboration aims for direct detection of light dark matter using germanium cryogenic detectors with low threshold phonon sensor technologies and efficient charge readout designs. We describe here the development of Ge bolometers equipped with high impedance thermistors based on a Nb_xSi_1−x TES alloy. High aspect ratio spiral designs allow the TES impedance to match with JFET or HEMT front-end amplifiers. We detail the behavior of the superconducting transition properties of these sensors and the detector optimization in terms of sensitivity to a-thermal phonons. We report preliminary results of a 200 g Ge detector that was calibrated using ^71Ge activation by neutrons at the LSM underground laboratory. | High Impedance TES Bolometers for EDELWEISS | 10.1007/s10909-022-02899-2 |
2023-06-01 | Nanoprecipitate-strengthened face-centered cubic high entropy alloys (NSFCC-HEAs) have huge potential for engineering applications due to their outstanding mechanical performance at extremely cryogenic temperatures. In this work, a temperature-dependent yield strength predictive theoretical model of NSFCC-HEAs was established by considering the evolution of main influence mechanisms with temperature, such as lattice friction stress, grain boundary strengthening, and precipitation strengthening. Only requiring some physical parameters at room temperature, the model can achieve good predictions of yield strength of NSFCC-HEAs at different temperatures, especially at extremely cryogenic temperatures, as verified by available experimental results. Furthermore, the contribution evolutions of each mechanism with temperature were quantitively analyzed by using the present model. It revealed theoretically that lattice friction and short-range order strengthening are the main mechanisms determining the temperature dependence of NSFCC-HEAs. In addition, the influences of grain size, precipitate size, and precipitate volume fraction were analyzed. The scope of applicability of the model was discussed. The model can provide a method to help save time and resources by reducing cryogenic temperature testing, and deepening the understanding of the relationship between microstructure and yield strength of NSFCC-HEAs at different temperatures. More importantly, the customized cryogenic-temperature strength of NSFCC-HEAs is expected to be achieved through a priori theoretical prediction by selecting the basic material parameters and the corresponding processing technology. Graphical abstract | Temperature-Dependent Yield Strength of Nanoprecipitate-Strengthened Face-Centered Cubic High Entropy Alloys: Prediction and Analysis | 10.1007/s12540-022-01331-4 |
2023-05-17 | Cryogenic heat treatment is an advanced heat treatment process employed to modify the microstructure of a cutting bit to enhance its properties. This research study aims to investigate the effects of deep cryogenic treatment under different soaking times on the tribological performance of rock cutting bits. Cryogenic treatment was applied for 12-, 18-, 24-, 30-, and 36-h soaking duration, and their corresponding microstructural modifications were identified through SEM and XRD analysis. In accordance with the mechanical properties of deep cryogenic treated WC, the hardness initially strengthened up to 24 h (52.49%). Further increase in cryogenic treatment (36 h) leads to drop in hardness (CT 36: 32.46%). The microstructural observation confirms the conversion of martensitic phase from fcc to hcp-Co phase. The atomic percentage of Co was found to be higher (35.42%) for CT 24 bit as compared to UT bit. The variation in properties is due to the formation of η carbides (Co_3W_3C, Co_6W_6C) and the martensitic transformation of α -Co to ε -Co phase. Wear tests were conducted under dry condition using CT and UT bits. Multi-criteria decision-making optimization has been carried out through the grey fuzzy integrated Taguchi technique to obtain the optimized soaking duration along with load and speed. To predict the value of GFRG, an ANFIS model was developed, which resulted in 94.57% prediction accuracy. The treatment time influences 86.29% of the output responses. According to the results obtained, CT 24 bit exhibited best optimized results as compared to other bits, and hence, 24-h cryogenic holding time can be recommended for rock cutting applications. Graphical Abstract | Microstructural and Tribological Characterization of Cryogenic Treated WC-Co Cutting Bits under Different Holding Times for Rock Cutting Applications | 10.1007/s11665-023-08291-9 |
2023-05-12 | In this study, the behavior of liquid nitrogen jets and dual-like jet impingement of liquid nitrogen discharged from needle injectors were evaluated. Water has also been used to investigate the behavior of liquid jets and jet impingement at low Reynolds numbers. High-speed photography has been used to investigate various patterns formed in this interaction. The velocities of the liquid nitrogen jets varied from 12 to 34 m/s corresponding to Reynolds number from 50,000 to 136,000. By qualitatively comparing the photographs taken from the water jet impingement, the velocity range and Reynolds number corresponding to closed rim, periodic rim, open rim and fully developed sheet models were determined. In this study, the breakup model of liquid nitrogen jet impingement in a test chamber with a pressure of 2 bar and a temperature of 77 K is a fully developed and the surface of jets is completely wavy. The impingement of wavy jets creates impingement waves on the surface of the sheet. As the speed of the jets increases, the dimensions of the liquid sheet become smaller due to the formation of stronger impingement waves and the faster breakup of the liquid sheet. In addition to liquid nitrogen jets, saturated liquid nitrogen jets have also been studied. The impingement of two saturated liquid nitrogen jets with an angle of impingement of 60 degrees and standard atmospheric condition and low injector pressure causes the formation of a two-phase spray sheet in the form of a bell. As the injection pressure increases, the liquid phase in the jet increases and the spray angle of the jet impingement increases. | Experimental study of atomization of liquid nitrogen jet impingement | 10.1007/s40430-023-04217-7 |
2023-05-03 | Carbon fiber–based polymer composites are frequently used in the aerospace industry due to their high specific strength-to-weight ratio and non-corrosive properties; they are extremely sensitive to foreign object impact. At the same time, the cost of carbon fiber was prohibitively expensive. The natural fiber was combined with the carbon fiber to minimize prices. This research aims to investigate the mechanical performance of pineapple leaf/carbon fiber–based hybrid composites in different cryogenic temperature settings (77 K for 20, 40, and 60 min) experienced in their service at extreme attitudes and low earth orbit (LEO) situations. The carbon/PALF blends were created using the vacuum bagging process on a polyester substrate. Such hybrids were laminated in a variety of combinations, including (PCP), (CPC), (PPP), and (CCC), with PALF indicated as P as well as carbon designated as C. Water uptake investigations revealed that the hybridization of all PALF and carbon specimens acquired water significantly at the start of the water uptake experiment and that the proportion of moisture uptake rose with the volume concentration of PALF in the specimens. The (CPC) hybrid composites had the highest mechanical modulus and stiffness when compared to other configurations. Whenever the exterior skin layers of PALF were replaced with carbon fibers in CPC composite structures, the tension, bending, and impact resistance significantly improved by 1.99, 1.98, and 1.94 times higher than pure PPP. According to the findings, the mechanical capabilities of the hybrid composites under cryogenic temperatures were only effective for 40 min. | Experimental investigations of physical and mechanical properties of pineapple leaf/carbon fiber–reinforced unsaturated polyester composites at liquid nitrogen environment | 10.1007/s13399-023-04263-0 |
2023-05-01 | 目 的 在使用引射器的基础上, 低温风洞排气系统利用风机和加热器可进一步降低排气羽流的沉降危害, 但也带来了高能耗. 本文旨在探讨排气出口倾斜角度对低温风洞低温氮气排气过程的影响, 并验证采用倾斜排气出口结构对降低低温风洞排气系统能耗的可行性. 创新点 1. 提出低温风洞倾斜出口排气方式; 2. 建立低温风洞排气塔缩比模型, 并开展倾斜出口排气过程的实验分析. 方 法 1. 根据相似性准则, 建立低温风洞排气塔缩比模型, 并通过实验对比倾斜出口排气过程和传统垂直出口排气过程, 验证倾斜出口排气方式是否可降低羽流沉降危害; 2. 通过实验与模拟对比, 验证低温羽流扩散数值模型的准确性; 3. 通过仿真模拟, 进一步量化研究倾斜出口排气方式的节能潜力. 结 论 1. 相比传统垂直排气方式, 30°或45°倾斜出口的排气方式可有效降低低温羽流的沉降危害; 2. 以0.3 m低温风洞极端排气工况为例, 采用30°或45°倾斜出口, 在无风条件下可节省15.9%的加热能耗; 3. 采用倾斜出口排气方式可以提高排气系统的安全下限. A new structural design for the vent stack with an inclined exit was proposed to reduce the settlement hazard of the cryogenic plume from a cryogenic wind tunnel; it extends the plume trajectory to increase the effective contact space and time for mixing between the plume gas and atmospheric air before the plume settles to the ground, contributing to more efficient energy consumption for heating. Reduced-scale experiments and numerical simulations of plume dispersion based on vertical and 30°- and 45°-inclined exits were conducted to study harm reduction and energy-saving potential. Analyses of the minimum temperature and minimum oxygen concentration of the plume near the ground indicate that the new exhaust design with an inclined exit clearly reduces the settlement hazard. Under windless conditions and without using a fan-ejector system, up to 15.9% of the heating energy used by the burner can be saved by adopting the new design. | Exhaust process of cryogenic nitrogen gas from a cryogenic wind tunnel with an inclined exit | 10.1631/jzus.A2200289 |
2023-05-01 | Abstract Based on the previously developed simplified method for constructing the equation of state for liquid and vapor phases, the thermodynamically consistent analytical equation of state for liquid and gaseous nitrogen in the molecular cryogenic conditions is obtained. While constructing the equation of state, the Mie–Gruneisen form was used as the sum of potential and thermal components for pressure and internal energy. The cold components of pressure and internal energy are described by a potential of the Born–Meyer type. For the thermal components, a simplifying approximation is adopted, which follows from the condition for the constant heat capacity and the dependence of Gruneisen function on the volume. When determining the equation of state for the vapor and liquid phases of nitrogen, the method of minimizing the standard deviation of the experimental and calculated data on isothermal compressibility, including the critical region and the phase equilibrium line, was used. The resulting equation of state for nitrogen makes it possible to study the phenomena associated with the processes of evaporation and condensation of nitrogen when modeling multiphase flows, taking into account interfacial heat and mass transfer under conditions of low pressures and cryogenic temperatures. | Equation of State for Liquid and Gaseous Nitrogen in Cryogenic Temperature Range | 10.1134/S1995080223050116 |
2023-05-01 | High hardness and exceptional machinability characterize the 6061 aluminum alloy. It is also a substance that welds nicely. It is extensively utilized in the railroad, shipbuilding, and aviation industries. This study used the face milling process on cryogenically treated aluminum 6061 alloys with normal and cryogenically treated PVD-AlTiN coated inserts. An orthogonal Taguchi L18 array was utilized to plan the experiment. Three cutting speeds, three different feed rates, and two different cutting inserts with conventional and cryogenic treatment were the cutting parameters employed in the studies. Roughness measurements were made after each experiment. In addition, each experiment was repeated six times, and the wear of the cutting insert was measured. The optimization of wear and roughness parameters employed the Taguchi method. Additionally, wear and roughness variables were co-optimized using Gray Relational Analysis (GRA). Taguchi optimization settings were optimized for the smallest surface roughness; the standard insert had a cutting speed of 250 m/min and a feed rate of 0.15 mm/rev. Optimized wear parameters include non-cryogenically treated (untreated) inserts, 350 m/min cutting speed, and 0.30 mm/rev feed rate. In the optimization using GRA, the non-cryogenically treated insert, 450 m/min cutting speed, and 0.15 mm/rev feed rate are the standard optimum parameters for roughness and wear. In terms of little wear and roughness, non-cryogenically treated inserts fared best, according to Taguchi and GRA findings. | Taguchi and Gray Relational Analysis Optimization of Cutting Parameters during Face Milling of Cryogenic Treated Aluminum 6061 Alloys Using Cryogenic and Non-cryogenic Inserts | 10.1007/s11665-023-08048-4 |
2023-05-01 | The quest for widespread applications especially in extreme environments accentuates the necessity to design materials with robust mechanical and thermodynamic stabilities. Almost all existing materials yield temperature-variant mechanical properties, essentially determined by their different atomic bonding regimes. In general, weak non-covalent interactions are considered to diminish the structural anti-destabilization of covalent crystals despite the toughening effect. Whereas, starting from multiscale theoretical modeling, we herein reveal an anomalous stabilizing effect in cellulose nanocrystals (CNCs) by the cooperation between the non-covalent hydrogen bonds and covalent glucosidic skeleton, namely molecular levers (MLs). It is surprising to find that the hydrogen bonds in MLs behave like covalent bindings under cryogenic conditions, which provide anomalously enhanced strength and toughness for CNCs. Thermodynamic analyses demonstrate that the unique dynamical mechanical behaviors from ambient to deep cryogenic temperatures are synergetic results of the intrinsic temperature dependence veiled in MLs and the overall thermo-induced CNC destabilization/amorphization. As the consequence, the variation trend of mechanical strength exhibits a bilinear temperature dependence with ∼ 77 K as the turning point. Our underlying investigations not only establish the bottom—up interrelations from the hydrogen bonding thermodynamics to the crystal-scale mechanical properties, but also facilitate the potential application of cellulose-based materials at extremely low temperatures such as those in outer space. | Molecular levers enable anomalously enhanced strength and toughness of cellulose nanocrystal at cryogenic temperature | 10.1007/s12274-022-5293-3 |
2023-05-01 | An approach is proposed to increasing the time of storage of cryogenic fluid in a horizontal cylindrical reservoir due to a reduction in the intensity of heat and mass transfer from its outer surface. A mathematical model has been developed for heat and mass transfer processes in cryogenic fluid on the basis of equations of unsteady nonisothermal turbulent motion of incompressible fluid. A k–ε turbulence model is used in the calculations. A comparison of the computational data with experimental findings has shown the adequacy of the proposed model. Based on the mathematical model, a possibility is shown for organizing a cryogenic fluid flow ensuring a reduction in the intensity of transfer of superheated liquid from the boundary layer near the reservoir surface into the zone of evaporation. We proposed a method for mechanical limitation of thermoconvective fluid flow from the reservoir walls to its fluid evaporation surface and a device for implementing this method. This device, unlike similar existing devices, has a small area of contact with the side surface of the reservoir and is invariant with regard to the level of cryogenic fluid in it. A computational experiment showed the efficiency of the proposed approach. Using the example of liquid nitrogen, hydrogen, and oxygen, it has been shown that the said device allows a reduction in the intensity of heating the surface of cryogenic fluid evaporation in the reservoir and an increase in the time of its storage. | Reduction in the Intensity of Heat and Mass Transfer in Cryogenic Fluid in a Horizontal Reservoir | 10.1007/s10891-023-02740-x |
2023-05-01 | Cryogenic CO_2-assisted minimum quantity lubrication milling technology is a green processing technology with broad application prospects. Aiming at the problem of tool wear in the application of cryogenic CO_2-assisted minimum quantity lubrication in difficult-to-machine materials and the influence of relevant parameters on tool wear, this study used coated cemented carbide tools to perform milling experiments under cryogenic CO_2-assisted minimum quantity lubrication technology conditions. The micro-morphology of the tool and chip was observed, and the energy spectrum of the tool chip contact area was analyzed. The results show that reducing CO_2 temperature and increasing the oil flow of minimum quantity lubrication can improve the tool wear. The tool wear mechanisms under cryogenic CO_2-assisted minimum quantity lubrication are mainly abrasive wear, diffusion wear, and oxidation wear. The chip sawtooth degree of the optimal parameter group is more conducive to chip breaking than that of dry-cutting and wet-cutting groups. The temperature of the tool-chip contact area is an important factor affecting tool wear; the higher the temperature, the faster the tool wear. At the same time, it is verified that cryogenic CO_2-assisted minimum quantity lubrication technology can replace cutting fluid in hard-to-machine materials under certain conditions. | Study on tool wear mechanism under cryogenic CO_2-assisted minimum quantity lubrication technology | 10.1007/s00170-023-11122-9 |
2023-05-01 | Abstract Magnetic levitation technologies are studied as an innovative basis for developing contactless systems for delivering cryogenic targets to the laser focus of an ICF facility or future power plant. A necessary element of such systems is a special target carrier made of high-temperature superconductors (HTSC) with high vortex pinning. It is shown experimentally that an HTSC carrier in the form of an outer coating of the target makes it possible to completely eliminate mechanical friction during target acceleration due to its levitation in gradient magnetic fields. The prospects for further development of this direction in the area of creating HTSC nanostructured films and coatings are discussed. | Delivery of an HTSC-Coated Levitated Cryogenic Target | 10.3103/S1068335623050032 |
2023-05-01 | Unlike the traditional air-cooling method, the AZ31B magnesium alloy surface was treated by laser surface melting in a liquid nitrogen cooling environment (LSM-LN). Microstructure, microhardness, and wear resistance tests were conducted to compare the substrate and laser-melted layer obtained in the liquid nitrogen cooling environment (LSM-LN layer). The grain size of the LSM-LN layer was much finer than that of the substrate, approximately 5.2 μm. The β -Mg_17Al_12 in the LSM-LN layer was far less than in the substrate. Under the comprehensive competitive factors of thermodynamics and kinetics, the mixed structure of nanocrystalline and amorphous appeared in some regions of the LSM-LN layer. Thermal stress was attributed to the uneven temperature change of the magnesium alloy in the laser heating and cooling process. Coupled with the magnesium alloy’s mechanical restraint stress, the LSM-LN layer’s dislocation density was greatly increased. Due to more remarkable grain refinement, solid solution strengthening, dislocation strengthening, and the amorphous structure, the microhardness and wear resistance properties of the magnesium alloy treated by LSM-LN were improved. | Microstructure and Wear Resistance of Laser Surface Melting-Treated AZ31B Magnesium Alloy in Cryogenic Medium | 10.1007/s11223-023-00552-1 |
2023-05-01 | A combinatorial high-throughput experiment (HTE) was used to optimize composition and process of nickel-saving cryogenic steel. A gradient temperature heat treatment method with a high linear distribution of heat treatment temperature using customized graphite sleeve direct current heating was used in the combinatorial HTE, which enhanced the richness of the sample library for the single preparation of the 10^2 level component process variables. Cryogenic steel with excellent mechanical properties was optimized using this combinatorial HTE, and the Ni content was reduced from the traditional 9 to 5.6 wt.% by using Mn instead of Ni. The heterogeneous structure architecture strategy and strengthening and toughening mechanism of the harmonic structure induced by intrinsic heat treatment of additive manufacturing were revealed. Taking the composition process optimization of Ni-saving cryogenic steel as an example, the boosting ability of combinatorial HTE in the research and development of new metal materials was proposed. | An optimization of harmonic structure nickel-saving cryogenic steel via combinatorial high-throughput experiment | 10.1007/s42243-023-00945-1 |
2023-05-01 | Abstract The boiling up process of the cryogenic liquid nitrogen jet outflow from a thin nozzle into a vacuum chamber from a high-pressure vessel is studied using the numerical approach that implements the developed two-phase model of a vapor-liquid mixture. The proposed model assumes the one-velocity, one-pressure, two-temperature approximations, takes into account contact heat transfer, non-equilibrium mass-transfer processes of evaporation and condensation with conditions control for the transition of bubble flow into vapor-droplet one. Numerical simulation of the process under consideration is performed in a three-dimensional axisymmetric formulation using the OpenFOAM software. Reliability substantiation of the developed model, its numerical implementation and the obtained solutions is given by its comparing with experimental data. Features of the bubble regime formation in the near zone at the nozzle exit with the transition to a vapor-droplet flow as the distance from the jet mouth increases are studied. | Modeling the Dynamics of a Boiling Liquid Nitrogen Jet under Cryogenic Temperatures | 10.1134/S1995080223050104 |
2023-04-01 | An experiment to investigate the two-phase closed loop thermosyphon (TPCLT) to cooling the compact superconducting magnet has been performed. This study is motivated mainly by our development of cryogenic cooling for a superconducting cyclotron magnet system. In the two-phase closed loop thermosyphon system, the cooling of the cold mass (27 kg copper block) from room temperature to 4 K is achieved in three stages by refilling subsequently the loop with Nitrogen (80 K), Neon (30 K) and Helium (4 K) based on the different boiling point of each of the gases. The cooldown process and efficiency were analyzed and compared with directly conductor cooling method. The results show that the TPCLT cooling method can reduce the liquid helium and shorten the cooling time, so it has a potential to achieve lower energy consumption and higher efficiency for cooling compact a superconducting magnet (the weight large than 100 kg) in practical applications. | Performance of Two-phase Closed Loop Thermosyphon in Cooling Down of Compact Superconducting Magnet | 10.1007/s10909-023-02957-3 |
2023-04-01 | Liquid oxygen and liquid hydrogen are used as oxidizer and fuel, respectively, in cryogenic stage of a typical heavy lift launch vehicle. In order to ensure optimum propellant loading and suppress cavitation in the pump, the propellants have to be stored at subcooled condition and this is achieved by increasing the ullage pressure above the saturation pressure. Also, due to low temperature of cryogenic propellants, significant amount of heat penetrates into the system. These factors contribute to the development of thermal stratification, wherein low-density liquid propellant, driven by buoyancy effects, gets accumulated at the vapor–liquid interface. The thickness of this stratum of liquid increases with time and plays a vital role in mass budgeting of propellants. Multi-species bubbling is one of the destratification techniques used in flight missions. Quantification of stratified mass in cryogenic stage and the estimation of time for destratification at different flow rate of bubbling gas are essential for the optimum loading of bubbling gas. In the present work, experimental studies were conducted with water-GN2 and liquid nitrogen (LN2)-GHe combination to investigate the development and destruction of thermal stratification of liquid in a sub-scale cylindrical tank of 90 L capacity. Tests with water at 305 K were conducted in open tank and heated using an external source. Tests with LN2 at 77 K, 2.8 bar was carried out using enclosed tank. Development of stratified mass was quantified in both cases based on stratified temperature limit, 311 K and 83 K, for water and LN2, respectively, using closely spaced T type thermocouples. Subsequently, destratification was carried out using gaseous nitrogen (GN2) and gaseous helium (GHe) for water and LN2, respectively. Experiments were conducted for bubbling flow rates in the range of 0.1–0.4 g s^−1. The time required for destratification was found to decrease significantly with increase in bubbling rate. 66.6% difference in destratification time is observed between bubbling gas flow rate of 0.1 and 0.4 g s^−1. The results obtained in the study can be used in the design and payload estimation of actual propellant tanks. | Experimental investigation of thermal stratification in cryogenic tank subjected to multi-species bubbling | 10.1007/s10973-022-11912-5 |
2023-04-01 | An epoxy resin is widely used as the matrix of composite structural materials due to its high mechanical properties, good heat resistance, corrosion resistance, and low cure shrinkage. However, an epoxy resin has poor crack resistance due to its inherent brittleness and is generally used together with a toughening agent. In this study, EPTS (epoxy-terminated phenyl tris(dimethylsiloxy)silane) was firstly synthesized via the hydrosilylation reaction of phenyltri(dimethylsiloxy)silane and allyl glycidyl ether in one step. EPTS was then mixed and cured with E51 epoxy resin to obtain a composite epoxy resin. The tensile test of the composite epoxy resin showed that the elongation at break increased to 11.03% at low temperature and 13.15% at room temperature. Dynamic thermomechanical analysis also fully confirmed the significant improvement in toughness. Finally, the toughening mechanism was revealed by Scanning electron microscope. This material has the advantages of simple synthesis process and low cost and shows a wide prospect. | A novel composite epoxy resin toughened by epoxy-terminated phenyl tris(dimethylsiloxy)silane at low temperature | 10.1007/s00289-022-04244-9 |
2023-04-01 | This study aims to investigate the impact of cavitation states on the stability of cryogenic pumps. Steady and unsteady simulations of the internal flow were conducted based on an SST k – ω turbulence model and a modified Zwart cavitation model considering thermodynamic effects. The modified cavitation model was verified using the hydrofoil model and compared with the Hord test results. The results indicate that the variation in pressure at the pump inlet has a significant influence on the cavitation in the pump. The cavitation states and fluid flow directions vary across the different spans in the impeller channel. The smaller the distance from the front cover of the impeller, the more severe is the cavitation, in addition to the appearance of a vortex. The influence of the formation of a longitudinal vortex at the impeller outlet on the pressure fluctuation in the cavitation state was revealed. The rotation of the impeller has negligible influence on the pressure load distribution at the blade inlet. However, it has a higher influence on that of the second half of the blade, particularly when the blade passes through the volute tongue. Cavitation can exacerbate the instability of pump operation. The research results are significant for accurately predicting cavitation performance and improving the anti-cavitation capability of cryogenic pumps. | Impacts of Cavitation on Flow Field Distributions and Pump Stability in Cryogenic Pumps | 10.1007/s10909-023-02944-8 |
2023-04-01 | Superalloys are high-performance advanced materials specifically suitable for industrial applications at high as well as sub-zero temperatures. They are widely used in manufacturing components exposed to harsh working environments for prolonged durations undergoing non-uniform strains. Most superalloys possess a face-centred cubic microstructure, enabling them to exhibit significant creep resistance, corrosion resistance and thermo-mechanical fatigue even at elevated temperatures. However, these properties result in increased heat generation, increased tool wear and poor surface integrity, rendering them difficult-to-machine materials. Initially, dry machining was adopted as a tool for sustainable machining, but a few inherent characteristics, like high heat generation and large cutting forces limit its scope in superalloys machining. Subsequently, flood cooling was introduced to eliminate these problems. However, this strategy had an adverse effect on the environment and worker's health. Thus, the need for an alternate cooling technique complying with sustainable principles becomes essential. This review article focuses on the prerequisites for sustainable machining in general and superalloys machinability in particular. A thorough literature survey has been carried out focusing on the superalloys and their sustainable machining. From the present survey, it can be concluded that sustainable techniques such as minimum quantity lubrication, nanoparticles-based cooling, cryogenic cooling and hybrid cooling; are considered to be the alternate choices for machining superalloys which not only improve the machinability of superalloys but are also economical and eco-friendly. In the end, it can be concluded that such sustainable machining techniques have an ever-growing and ever-lasting scope, specifically in machining high-strength materials like superalloys. Graphical abstract | Applications of sustainable techniques in machinability improvement of superalloys: a comprehensive review | 10.1007/s12008-022-01053-2 |
2023-04-01 | Compacted graphite iron (CGI) is a metal that exhibits remarkable mechanical properties based on the adhesion of graphite and iron particles. CGI has attracted considerable attention from the automobile industry and has been used as a substitute for gray iron. However, CGI is hard to machine because of high strength and toughness. In this study, a cryogenic machining process was applied to CGI, and numerical studies were performed. Cryogenic machining uses liquid nitrogen (LN2) as a coolant, as this improves machinability. In the numerical study, cutting force and temperature were simulated, and machining characteristics were analyzed according to the cutting condition during cryogenic end-milling. The cutting force was predicted using a model of material plastic behavior, and the tool geometry and machining conditions were the input parameters. The contact mechanism between LN2 and the work material was studied, and the cutting temperature was simulated according to the rotation angle of the cutting tool. The numerical modeling was experimentally validated. The simulation and experimental machining data were in good agreement; the maximum and minimum errors were 31.5% and 2.6% for the cutting force and 17.6% and 10.3% for the temperature, respectively. The effects of cryogenic cooling were further studied experimentally. The sprayed LN2 increased the cutting force and decreased the temperature and tool surface friction. The friction decreased slightly with the insignificant influence on cutting force. | Numerical evaluation of the cryogenic cooling effect on compacted graphite iron during end-milling | 10.1007/s00170-023-11055-3 |
2023-04-01 | Abstract This study considers structural drawings and methods for cooling high-voltage terminals (current leads) of superconducting power cables based on high-temperature superconductors. The operation of these terminals cooled by gaseous nitrogen and helium is analyzed using theoretical thermal models that describe the distribution of temperature and heat flow along current leads in ideal and actual heat exchange. The change in the ratio of optimal current densities and specific heat influxes to the source of cold is shown depending on the flow rate and nature of the cooling gas. It has been quantitatively determined that gaseous helium used for cooling the current-conducting members of the terminals produces a more significant effect than nitrogen. | Features of Cooling Current Leads (Terminals) for Power Cables Based on High-Temperature Superconductors | 10.3103/S1068371223040028 |
2023-03-31 | The Volume of Fluid (VOF) method was used to numerically study the configuration characteristics of the vapor region in the cryogenic propellant tank under microgravity in this study. The deformation characteristics of the gas–liquid interface, the bubble motion and coalescence characteristics in the tank were analyzed. The liquid infiltration and liquid infiltration expansion were proposed to evaluate the vapor region deformation characteristics under microgravity, and the stagnation time was proposed to describe the bubble motion characteristics. Results showed that the surface tension drove the liquid to climb along the wall under microgravity. When the filling rate was 95%, the liquid infiltration decreased as the contact angle and the gravity level increased. Under 10^−5 g gravity level, when the contact angle was 5°, the tank with 80% filling rate had the largest increased infiltration area, while the infiltration expansion ratio decreased when the filling rate was less than 65%. The average velocity of the bubble motion increased with the increase of Eötvös number (Eo). When the radius of the bubble located in the center of the tank was less than 100 mm, the bubble had a stagnation period before moving. The stagnation time increased with the decrease of the bubble radius. Multiple bubbles could coalesce to form a large bubble similar to an ellipsoid under microgravity. The results verified the feasibility of the lumped vapor method under microgravity, and the finally stable shape of the vapor region was similar to an ellipsoid. | Numerical Simulation of Vapor Configuration and Bubbles Coalescence in Cryogenic Propellant Tank Under Microgravity | 10.1007/s12217-023-10045-0 |
2023-03-30 | Herein, the effects of quenching, lamellarizing, and tempering (QLT) on reversed austenite and cryogenic toughness of 9Ni steels were investigated in terms of microstructure characterization, internal friction tests, and low temperature impact tests. The results showed that QLT treatment not only refined the grain effectively, but also promoted the formation of reversed austenite, thus obtaining excellent ultra-cryogenic toughness. Furthermore, QLT treatment promoted the redistribution of C, Mn, and Ni elements, so that more stable austenite was retained to room temperature. The phase transformation peak in the internal friction peak confirmed that QLT treatment effectively promoted the formation of reversed austenite, while the Snoek–Kê–Köster peak showed a strong interaction between carbon atoms and dislocations. Due to the synergistic effect of fine grain toughening and TRIP effect, the 9Ni steel treated by QLT appeared more excellent ultra-cryogenic toughness.Please check and confirm the corresponding author mail id is correctly identified.The corresponding author mail id is correct. | Effect of Quenching, Lamellarizing, and Tempering on Reversed Austenite and Cryogenic Toughness of 9Ni Steels | 10.1007/s11665-023-08129-4 |
2023-03-01 | A new technology for replenishing daily nitrogen losses (200 g/day) in the atmosphere of the Russian segment of the International Space Station and for cooling the on-board electronic devices is proposed. This technology can be used to create systems for solid nitrogen storage and for release of gaseous nitrogen to create an atmosphere in the living compartments at space stations and, in the future, at the Lunar Station. | Use of Solid Cryogenic Agents in Space Station Life Support System for Creating Atmosphere Constituents | 10.1007/s10556-023-01193-6 |
2023-03-01 | Abstract The operation of a cryogenic fuel system is considered by means of model calculations corresponding to several flight specifications for a civil aircraft fueled by liquefied natural gas. | Thermal State of Cryogenic Fuel System in Civil Aircraft with Different Flight Patterns | 10.3103/S1068798X23040044 |
2023-03-01 | This paper proposes a combined treatment of secondary aging (T6I4) and deep cryogenic treatment (DCT), which includes initial aging, DCT, and re-aging, to improve the limitations of secondary aging (T6I4) treatment on enhancing the mechanical properties of AA2024. The scanning electron microscopy and transmission electron microscopy (TEM) are used to observe the alloy's microstructure, and hardness measurements, tensile tests, friction and wear tests, intergranular corrosion tests, and electrochemical corrosion tests are used to determine the alloy's properties. On comparison with T6I4, AA2024-T6I4 with DCT for 1 h increases its hardness, tensile strength and wear resistance, as well as its corrosion resistance. A TEM analysis of AA2024-T6I4 with DCT for 1 h reveals uniform distribution of fine matrix precipitates, a small size difference, and discontinuous and fine grain boundary precipitates within the alloy. | Study on Microstructure and Properties of AA2024-T6I4 with Deep Cryogenic Treatment | 10.1007/s12666-022-02764-6 |
2023-03-01 | The effect of heat treatment involving water quenching, cooling of the quenched alloy in liquid nitrogen, a hold in liquid nitrogen, heating in hot mineral oil (thermal shock), and natural or artificial aging on the structure and properties of deformable aluminum alloy D16 is studied. The structure of the alloy is analyzed by optical and transmission electron microscopy and x-ray diffraction analysis. The effect of the heat treatments on the residual microstresses is determined by the method of drilling holes, and the mechanical properties of D16 are determined in tensile tests. | Effect of Cryogenic Treatment and Thermal Shock on Residual Stresses, Structure and Properties of Alloy D16 | 10.1007/s11041-023-00878-2 |
2023-03-01 | Abstract This review considers advances in the field of epoxy adhesives that can work at elevated and negative temperatures. Methods for modifying epoxy adhesives and examples of adhesive materials for operation in a wide temperature range have been considered. | A Review of Modern Adhesive Materials Operating in a Wide Temperature Range. Epoxy Adhesives | 10.1134/S1995421223010069 |
2023-03-01 | The liquid nitrogen (LN2) supplying system, one of the four key systems of the cryogenic wind tunnel (CWT), is an essential guarantee for the precise control, fast and safe regulation of the wind tunnel’s total temperature. Firstly, the technical schemes, advantages and disadvantages of different LN2 supplying systems are discussed and analyzed based on the operation conditions and test requirements of different CWTs. Then, together with the development of the pilot cryogenic transonic wind tunnel (PCTW), the key technologies of the system, including the supplying mode, rapid and accurate regulation of injection pressure, development of large scale cryogenic centrifugal pump, and matching technology between pumps and pipe network, have been summarized and the solutions to the existing issues are given. Finally, a supplying process suitable for large-scale CWT is proposed, which has the ability of independent commissioning, rapid regulation, accurate control of injection pressure and transient response to the wind tunnel’s wide range of working conditions. The breakthrough in LN2 supplying system enables China to construct a CWT for the future competitive high Reynolds number aircraft. | A Review on the Precise Control of the Liquid Nitrogen Supplying System in Transonic Cryogenic Wind Tunnel | 10.1007/s11630-023-1762-6 |
2023-03-01 | This paper studies the improvement in machining performance by implementing a hybrid coolant approach for the machining of difficult-to-machine Inconel 625 superalloy. This study differs from the pre-existing hybrid cooling methods by using a novel modified tool holder for the supply of cryogenic coolant. An external nozzle is also involved as part of the coolant system to provide MQL spray to the cutting zone in hybrid cooling. Turning experiments using MQL, cryogenic cooling with an external nozzle, cryogenic cooling with a modified tool holder and hybrid cryo-MQL cooling were performed at different parameter levels to analyze the machining performance of the proposed new cooling technique. The results show that a maximum reduction of 30.52%, 63.67%, and 43.27% was observed for surface roughness, tool wear, and cutting forces using the hybrid cooling technique. The tool wear types and mechanisms underlying the wear formation when using various techniques for cooling are studied using SEM imaging of tooltips. Also, the chip morphology study was carried out to compare the effects on machinability. | Experimental investigation of hybrid cooling approach using a modified tool holder for turning of Inconel 625 superalloy | 10.1007/s00170-022-10781-4 |
2023-03-01 | The effect of modified atmosphere packaging (MAP) on nutritional stability and quality retention of oyster meat ( Crassostrea virginica ) during frozen storage was investigated. Fresh oyster meat (300 g) was cryogenically frozen, placed in trays, and film sealed in (1) 100% CO_2 (MAP-CO_2), (2) 100% N_2 (MAP-N_2), and (3) 100% air (AIR) followed by 180 days of frozen storage (–20 °C). Oyster meat quality (color, moisture, pH, drip loss, lipid oxidation, and texture) and nutritional stability (amino acid profile and volatile compounds) were evaluated. AIR and MAP-N_2 samples showed similar quality parameters after 180 days. In MAP-CO_2 samples, oysters’ meat pH decreased due to CO_2 absorption, texture increased, and packages collapsed. MAP with CO_2 and N_2 were effective in reducing lipid oxidation. In all samples, the amino acid composition remained stable, and most of the volatile compounds identified came from the degradation of n-3 polyunsaturated fatty acids. Trimethylamine (seafood spoilage indicator) was not identified in any treatment. This study demonstrated that oyster meat in MAP with high nitrogen content maintained its freshness and quality during frozen storage. | Modified Atmosphere Packaging (MAP) on Nutritional Stability and Quality Retention of Oyster Meat (Crassostrea virginica) During Frozen Storage | 10.1007/s41783-022-00145-4 |
2023-03-01 | In the current work, a typical NiCrAlY alloy and two novel amorphous Fe-based alloys were arc-sprayed for the desired application as insulative coatings in cryogenic environments such as for the inner walls of LH2 tanks. For the experiments, nitrogen was used as process gas, while the stand-off distance and number of passes were varied. The deposition efficiency, tensile adhesive strength, hardness, durability under cryogenic conditions, and thermal diffusivity were investigated. Another focus included the visual and chemical characterization of the microstructures and potential changes in these due to the harsh temperature regime. Additionally, the residual stresses within the coatings were measured by the incremental hole drilling method based on electronic speckle pattern interferometry and correlated with the other coating properties. This was done to estimate the influence of the stress state on possible coating delamination in the tanks over a longer period. The results demonstrate coatings with low, but varying porosity and oxide content as well as material-dependent correlations to electrical conductivity. In particular, the amorphous Fe-based coatings reveal homogeneous coating structures and promising properties in terms of insulation capacity for use in various cryogenic applications. | Highly Efficient Thermal Barrier Coatings Based on Arc Spraying of Amorphous Fe-based Alloys and NiCrAlY for Use in LH2 Tanks and Other Cryogenic Environments | 10.1007/s11666-023-01548-8 |
2023-02-12 | Cryogenic treatments represent an innovative technology developed with the aim of improving the performance of metallic alloys. The beneficial effects on steels are well documented in the literature, whereas their influence on other materials, such as aluminum alloys, is still not completely clarified. Even if the scientific literature reports conflicting data and conclusions, the industrial applications of such treatments are constantly growing. In the present experimental work, the mechanical and corrosion properties of a high-performance 7050 aluminum alloy plate were studied after cryogenic treatment at − 196 °C in liquid nitrogen. Tensile tests were performed on heat-treated samples, and intergranular corrosion tests were carried out on prismatic samples, according to ASTM G110-92 standard. The specimens were exposed to the corrosive environment and the effect of intergranular corrosion was measured by quantitative analysis using light-optical microscopy (LOM). Whereas trifling variation was observed in the mechanical resistance and plastic behavior, the corrosion tests showed a benefic effect of the cryogenic treatment. The microstructure was investigated by FEG-SEM analysis, revealing a different distribution of precipitates near the grain boundaries, which was able to reduce the electrochemical potential difference among these regions and the center-grain. | Deep cryogenic treatment of AA7050: tensile response and corrosion susceptibility | 10.1007/s43939-023-00037-7 |
2023-02-01 | Abstract We present experimental results on the loading/unloading working fluid of the cryogenic moderator of a DARIA compact neutron source. A technology for loading liquid nonirradiated mesitylene into a specially designed prototype of the cryogenic moderator chamber and a technology for unloading irradiated mesitylene with a different absorbed dose of ionizing radiation are proposed and experimentally validated. During the experiments, the chamber prototype worked flawlessly in conditions as close as possible to real operating conditions of the cryogenic moderator of a compact neutron source. | Tests of the Prototype Chamber of the Cryogenic Moderator of the DARIA Compact Neutron Source | 10.1134/S1547477123010041 |
2023-02-01 | Continuous quest for lighter yet stronger materials has led to significant research in the field of composites. Modern-day nanocomposites have found widespread applications in diverse engineering sectors, which often require their machining. In this paper, multi-walled carbon nanotubes (MWCNTs) reinforced composites are subjected to drilling operation under cryogenic condition. To investigate the effects of different drilling parameters, like drill type, feed rate and spindle speed on delamination factors at drill entry and exit, circularity error and surface roughness, a three-level full factorial experimental study consisting of 27 experiments is carried out. To determine the optimal combination of drilling parameters, a recently developed multi-criteria decision making tool in the form of combined compromise solution (CoCoSo) method is employed. Five different objective criteria weight allocation techniques, i.e. mean weight method, standard deviation method, entropy method, criteria importance through intercriteria correlation method and method based on the removal effects of criteria are considered in this paper to avoid subjectivity in the decision making process. The optimal drilling parameters derived using the combined applications of CoCoSo and different criteria weight allocation techniques are also compared. Based on the experimental observations, it can be concluded that a TiCN coated drill with 10 mm/min feed rate and 1500 rpm spindle speed would provide the most desired response values during cryogenic drilling of MWCNTs reinforced composites. | CoCoSo method-based optimization of cryogenic drilling on multi-walled carbon nanotubes reinforced composites | 10.1007/s12008-022-00894-1 |
2023-02-01 | Observation window is an important component for visual observation during cryogenic wind tunnel testing. However, the change of temperature and pressure in the wind tunnel may lead to thermal stress and deformation of the observation window, threatening the safety of observation window. On this account, aiming to improve observation window structure, the temperature and stress fields of observation window for continuous transonic cryogenic wind tunnel were investigated by a fluid-solid-thermal coupling finite element method in this work. A numerical calculation model of cryogenic observation window was established based on the designed boundary and initial conditions. A fluid-solid-thermal coupling analysis was carried out to investigate the temperature and stress fields, respectively. Finally, taking the flow rate of nitrogen as the variable and the surface temperature of outer plexiglass as the optimization objective, the heat exchange parameter of the observation window was optimized. The obtained results showed that when the flow rate of nitrogen was 20 m·s^− 1 (the mass flow of nitrogen was equal to 0.00291 kg·s^− 1), the temperature of the outer plexiglass was 289.6 K after 10,800 s, which was 1.3 K higher than the dew point temperature. This can ensure clear observation through the cryogenic observation window. This work provides the guidance and reference for the heating gas consumption of cryogenic wind tunnel. | A Multiple-Field Finite Element Method Analysis of Observation Window for Cryogenic Wind Tunnel | 10.1007/s40799-022-00561-w |
2023-02-01 | The cooling time of cryogenic vaporised Ar shielding/cooling of Ti-6Al-4 V deposits was ~ 10 times faster than that of normal Ar gas shielding/cooling. The columnar β grains in rapid cooling condition were observed to be in the longitudinal direction of the deposits same as that in natural cooling condition. Under the rapid cooling, a narrow heat-affected zone band (~ 70 μm) and a wide vanadium-segregation band was observed, along with a reduced aspect ratio of the α plate, which led to improved isotropic-tensile properties along the deposition and building directions. Rapid cooling condition also retained a significant amount of O and N, which enhanced its hardness and tensile strength. Thus, cryogenic vaporised Ar shielding/cooling can produce Ti-6Al-4 V wire-arc additive manufacturing deposits with better tensile properties compared to normal Ar gas shielding. Graphical abstract | Enhancing Tensile Properties of Wire-Arc Additively Manufactured Ti-6Al-4 V Deposits Via Cryogenic Vaporised Ar Shielding/Cooling | 10.1007/s12540-022-01272-y |
2023-02-01 | In this paper, the detailed photophysical properties of two phosphorescent salts, [Ir(ptpy)_2(4,4′-Cl_2bpy)]PF_6, 1 , and [Ir(4-Clppy)_2(4,4′-Cl_2bpy)]PF_6, 2 , where ptpy = 2-( p -tolyl) pyridinato; 4,4′-Cl_2bpy = 4,4′-dichloro-2,2′-bipyridine, and 4-Clppy = 4-chloro-2-phenylpyridinato) have been studied in CH_2Cl_2 and PS (polystyrene) film at 77–300 K and in PMMA (polymethyl methacrylate) film in the temperature range of 1.5–300 K. The decay curves are monoexponential in the whole range. Temperature versus the decay time plots in PMMA for complexes display two distinct ranges, one at low temperature ( T ≤ 77 K) with Ф _PL ≈ 100% that corresponds to thermal distribution between the triplet substates, and the other at higher temperatures ( T > 77 K) in which the decay time reaches a plateau and the Ф _PL starts to decrease and amounts to Ф _PL = 35% and 60% for complexes 1 and 2 , respectively, at room temperature. Applying the three-level equation in the first part gives the values of τ (I) = 110 μs, τ (II) = 10.5 μs, τ (III) = 342 ns for complex 1 and τ (I) = 142 μs, τ (II) = 11 μs, τ (III) = 353 ns for complex 2 . Obtained zero-field splitting of 105 and 110 cm^−1 of T _1 state of complexes 1 and 2 , respectively, can be assigned to be largely of ^3MLCT character of this state. For the second part ( T > 77 K) with the contribution of the thermally activated decay processes, we add two additional terms in Eq. ( 1 ) to get the decay rate k ( Q ) = 7.2 × 10^6 s^−1, ∆E( Q -I) = 304 cm^−1 for 1 and k ( Q ) = 4.3 × 10^6 s^−1 and ∆E( Q -I) = 638 cm^−1 for 2 which proposed the active role of metal-centered (^3MC) triplet excited states in the non-radiative deactivation pathways. Graphical abstract | Comprehensive investigation of triplet states of red phosphorescent cationic Ir(III) complexes from cryogenic temperature | 10.1007/s13738-022-02680-y |
2023-02-01 | High spatial resolution mass spectrometry imaging has been identified as a key technology needed to improve understanding of the chemical components that influence antibiotic resistance within biofilms, which are communities of micro-organisms that grow attached to a surface. Time-of-flight secondary ion mass spectrometry (ToF–SIMS) offers the unique ability for label-free 3D imaging of organic molecules with sub-micrometer spatial resolution and high sensitivity. Several studies of biofilms have been done with the help of ToF–SIMS, but none of those studies have shown 3D imaging of antibiotics in native-state hydrated biofilms with cell-level resolution. Because ToF–SIMS measurements must be performed in a high-vacuum environment, cryogenic preparation and analysis are necessary to preserve the native biofilm structure and antibiotic spatial distribution during ToF–SIMS measurements. In this study, we have investigated the penetration of the antibiotic ciprofloxacin into Bacillus subtilis biofilms using sub-micrometer resolution 3D imaging cryo-ToF–SIMS. B. subtilis biofilms were exposed to physiologically relevant levels of ciprofloxacin. The treated biofilms were then plunge-frozen in liquid propane and analyzed with ToF–SIMS under cryogenic conditions. Multivariate analysis techniques, including multivariate curve resolution (MCR) and inverse maximum signal factor (iMSF) denoising, were used to aid analysis of the data and facilitate high spatial resolution 3D imaging of the biofilm, providing individually resolved cells and spatially resolved ciprofloxacin intensity at “real world” concentrations. Graphical Abstract | Label-free sub-micrometer 3D imaging of ciprofloxacin in native-state biofilms with cryo-time-of-flight secondary ion mass spectrometry | 10.1007/s00216-022-04496-4 |
2023-02-01 | Carbon-reinforced aluminum laminate (CARALL) structures, by exposure to various aging conditions, were studied to examine the effect of aging on their impact properties. After 40 thermal cycles between 25 and 100 ℃, there was improvement in impact strength of the structures with unidirectional configurations, with maximum improvement of 22.5%. Under isothermal condition (at constant temperature of 100 ℃), a 350 min aging caused 47.7% improvement in the impact strength. By applying cryogenic cycles between − 196 and 25 ℃, in some structures the impact strength improved after 20 cycles, whereas other structures improved after 50 cycles. The most improvement in the impact strength under cryogenic isothermal condition was about 53.5%, obtained after aging for 150 min at − 196 ℃. It was found that fibers pull out, fracturing, and layers delamination are the mechanisms responsible for deterioration of impact strength. Whereas, lateral and longitudinal crack propagation and the plastic deformation of aluminum layers are the energy absorption mechanisms, which can improve the impact strength. Graphical Abstract | Impact properties of carbon fibers-epoxy composite/aluminum laminates: effect of cryogenic and thermal aging | 10.1007/s13726-022-01116-x |
2023-01-18 | Surgical sutures are one of the most widely used medical devices for wound closure. In the meantime, the suture surface and area may be exposed to many microorganisms, and surgical site infections may develop in these environments. Today, giving antimicrobial properties to polymeric sutures has been one of the methods used to prevent these infections. In this study, the absorbable polymeric-based suture (Pegelak®) was homogeneously coated with nano-sized silver particles by the vacuum deposition at the cryogenic temperatures (< 300 K) instead of the commonly used vacuum deposition at high substrate temperatures, and its physical and antibacterial properties were investigated. It was determined from the morphological and tensile strength analysis that some deformations occurred in the Ag-coated suture at 300 K; however, the coating of the suture at 200 K did not significantly affect the morphological and mechanical properties of the suture. According to photocurrent measurement, the plasmon resonance effect of the Ag-nanoparticles-coated suture at 200 K was observed around 450–525 nm. The illumination of the Ag-coated suture at 200 K with light in the plasmon resonance wavelength region increased the Ag^+ release from 3.67 × 10^−3 ppm to 6.65 × 10^−3 ppm. In the microbiological analysis, it was observed that Ag-coated sutures obtained at both 200 K and 300 K showed antibacterial activity against all tested bacteria. | Deposition and characterization of the Ag nanoparticles on absorbable surgical sutures at the cryogenic temperatures | 10.1007/s00339-023-06406-6 |
2023-01-16 | Cobalt-based superalloys are widely used in hot-end components of gas turbines due to their excellent elevated temperature mechanical properties. At present, cobalt-based superalloys are usually machined under cutting fluid, which will seriously pollute the environment and harm human health. Cryogenic cutting technology uses liquid nitrogen, supercritical carbon dioxide, etc. as the cooling medium, which has the advantages of environmental protection and energy conservation. In this paper, the cryogenic mechanical properties of cobalt-based superalloy GH605 were investigated, and then the cutting experiments were conducted under three different cooling and lubrication methods (flood condition, cryogenic minimum quantity lubrication, and liquid nitrogen) to investigate the cryogenic machinability and machining sustainability of GH605. The results show that cryogenic temperature can reduce the plasticity of GH605 but has little effect on the compressive yield strength and compressive strength. Compared with the cutting fluid, the cutting force of liquid nitrogen is reduced by up to 72.2%, the cutting-specific energy is reduced by about 83.9%, and the concentration of particulate matter such as PM_2.5 generated during the processing can be decreased by more than 60%. The surface finish and consistency of cryogenic minimum quantity lubrication are better; the surface roughness is reduced by 0.4 ~ 20.4% at different cutting speeds. When the feed speed is greater than 0.10 mm/r, the work hardening degree decreases by 0.8 ~ 19.7%. Under the two cooling strategies, the chip surface is smooth and flat, chip breaking property is improved, but the machining noise is more than 100 dB. | Investigation of machining property and sustainability performance of cryogenic turning of GH605 superalloy | 10.1007/s00170-023-10816-4 |
2023-01-10 | A first time-resolved pressure-sensitive paint (PSP) test campaign at the European Transonic Wind Tunnel (ETW) was conducted within the research initiative “Unsteady flow and interaction phenomena at High Speed Stall conditions”. One of the objectives of this wind tunnel campaign was to resolve time-series of surface pressure distributions caused by complex 3-D buffet phenomena on a full-span airplane model XRF-1 transport aircraft configuration. At higher angle-of-attack and high Mach number, pressure fluctuations with a frequency of several hundred Hertz are expected to occur on the main wing and the horizontal tail plane (HTP) caused by the buffet effect. To capture the expected buffet phenomena by PSP, the German Aerospace Center developed a time-resolved PSP measurement and data acquisition system as well as a post-processing method for measurements in ETW. The measurements were conducted on the main wing and HTP simultaneously, with a camera frame rate of up to 2 kHz. The transonic buffet phenomena were observed at the flight relevant Reynolds number Re = 12.9 × 10^6 and Re = 25.0 × 10^6. The time-varying surface pressure distribution on the model was successfully captured by PSP. The time-series and spectra of both PSP and pressure transducer data match very well. | Time-resolved pressure-sensitive paint measurements for cryogenic wind tunnel tests | 10.1007/s13272-022-00637-8 |
2023-01-01 | The paper aims to analyze the cryogenic blasting market in Russia and determine the prospects for its development. The authors use general scientific and experimental-theoretical methods. The supply of equipment for cryopreservation is mainly carried out by foreign companies, although the presence of individual Russian enterprises in the market is becoming more active. Cryogenic blasting services are more expensive than conventional cleaning methods. Prices for cryogenic blasters vary widely depending on the brand, design, performance, and specifications. The main competitive advantages of Russian cryogenic blasters are the price and efficiency of equipment operation. Despite the active promotion of cryogenic blasting by interested companies, this technology is becoming increasingly popular and it is likely to be present in the Russian market along with other high-pressure cleaning technologies. Cryogenic blasting is increasingly used in various industries, where the largest market share is occupied by the industrial cleaning segment, which is expected to continue to dominate. This issue is actively discussed in journalistic and industrial circles, but it is insufficiently reflected in science. | Analysis of the Market for Cryogenic Blasting in Russia | 10.1007/978-3-031-29489-1_36 |
2023-01-01 | High Intensity Heavy-ion Accelerator Facility (HIAF) is a new heavy ion accelerator facility in China. HIAF Fragmentation Separator (HFRS) is a fragmentation separator which employs coil dominated superconducting DCT multipoles and superferric dipoles operating at 4.5 K. A 2.5 kW helium refrigerator and a helium distribution system are designed for the operation of all 24 superconducting magnet cryostats, some of which contains more than one magnet. In this paper, we will discuss the key features of the whole cryogenic system include the cooling method, the refrigerator, and the cryogenic distribution system. | Conceptual Design of Cryogenic System for HFRS of HIAF Project | 10.1007/978-981-99-6128-3_40 |
2023-01-01 | Shenzhen Superconducting Soft-X-ray Free Electron Laser (S^3FEL) is located at Shenzhen, China. It is planned to construct a 2.5 GeV CW superconducting radio frequency linear accelerator and four beam lines, aiming at generating X-rays with a high repetition frequency. The accelerator consists of twenty-five 1.3 GHz cryomodules (CM) and two 3.9 GHz cryomodules, of which its SRF cavity need to be operated at 2 K condition. To maintain the 2 K environment, cryogenic distribution system (CDS) is designed to interconnect the CMs and the Cryoplant (CP) and supply cryogens from the CP to the LINAC. This paper presents the preliminary design result and current status of the CDS, which including overall specification and design consideration. In addition, a thermodynamic calculation is performed based on current design result. Those analyses provide sufficient evidence for the performance margin of the CDS design. | Flow Process Analysis of the Cryogenic Distribution System for S^3FEL Project | 10.1007/978-981-99-6128-3_15 |
2023-01-01 | The A1900 fragment separator segment of the continuous wave heavy ion beam linear accelerator at the Facility for Rare Isotope Beams (FRIB) consists of twelve superconducting magnets. In the past, these superconducting magnet cryostats (and associated beamline, cryogenic distribution system) were part of the Coupled Cyclotron Facility (CCF). Reconfiguration of these superconducting magnets for the FRIB fragment separator required re-routing, rebuilding and addition of new cryogenic distribution lines. The re-configured A1900 fragment separator segment cryogenic distribution was designed using the same operational concept used for the FRIB experimental system cryogenic distribution system – which has separate lines for cool-down and 4.5 K operation. This provided flexibility for commissioning, operation, and maintenance of the segment without affecting other loads. These modifications of a legacy system to fit new requirements presented several design challenges which were resolved during the concept design phase. Design, fabrication, and installation of most of the elements of the cryogenic distribution system were carried out in-house at FRIB. This paper presents an overview of the process design, analysis, fabrication, and installation of the re-configured A1900 fragment separator cryogenic distribution system. | Design, Fabrication and Installation of the Cryogenic Distribution System for Re-Configured FRIB A1900 Fragment Separator | 10.1007/978-981-99-6128-3_28 |
2023-01-01 | Many space exploration components require a cryogenic working environment below 200 K. In order to avoid the electromagnetic interference and mechanical vibration of the cryocooler to the detector, an efficient cryogenic heat transfer device is required to realize the transfer from the cryocooler to the payload. Due to their advantages of high heat transfer efficiency, high flexibility, and flexible arrangement, loop heat pipes have become an effective way of cryogenic heat transfer in space. However, researches on cryogenic loop heat pipes (CLHP) are mainly experimental studies in the liquid nitrogen temperature zone, and few studies were carried out for CLHPs in the 150–200 K temperature zone. Therefore, a two-dimensional numerical model was established to calculate the performance of CLHP in different working temperatures. Additionally, an experimental and theoretical research on a 150–200 K CLHP charged with ethylene was carried out in this paper. Tesla valves were used to control the flow direction, the supercritical startup characteristics was experimentally investigated under different heating powers on the secondary evaporator. This work will facilitate the design of cryogenic thermal control for space and ground applications. | A Novel Cryogenic Loop Heat Pipe Structure and Preliminary Proof of the Concept | 10.1007/978-981-99-6128-3_57 |
2023-01-01 | As an important part of the High Intensity heavy-ion Accelerator Facility (HIAF), High energy FRagment Separator (HFRS) consists of a two-stage superconducting magnetic system, the pre-separator and the main-separator, which is cooled down by a helium cryogenic refrigerator. In this work, the helium cryogenic refrigerator is designed and optimized to satisfy the cooling capacity larger than 1kW @4.5 K and 10 kW @ (50 ~ 80 K) at the same time. Furthermore, this helium cryogenic refrigerator is integrated and preliminary tested. 300 ~ 4.5 K cool-down processes of cryogenic heat exchangers are presented. The cooling capacity of this refrigerator system is up to 1468 W @4.5 K in the commissioning, which will be improved in the further investigation. | Design and Preliminary Test of a Helium Cryogenic Refrigerator for the High Energy FRagment Separator of HIAF | 10.1007/978-981-99-6128-3_3 |
2023-01-01 | The thermal insulation performance is a very important parameter for cryogenic vessel reflected by heat leak and evaluated by loss product. The standard stipulates that the heat leak in a cryogenic vessel is the latent heat of loss product considered the loss product is saturated as it flows out of the inner vessel. In fact, the gas in cryogenic vessel is unsaturated and its temperature is higher than the saturation temperature during the loss product test of a cryogenic vessel. Therefore a part of the heat leak is absorbed by the loss product because its temperature increases as flowing through the gas of cryogenic vessel. In response to this problem, the heat transfer process was further studied and analyzed during the loss product test, and the energy equations of the gas and liquid were established to research the heat leak in cryogenic vessels, especially for the increased enthalpy of the loss product. The experiment was completed to verify that the heat leak in a cryogenic vessel includes the increased enthalpy of the loss product besides the latent heat in the test. The results indicate that the increased enthalpy is critical for the heat leak in cryogenic vessels during the loss product test, and its ratio is over 26% with respect to the latent heat as the liquid level ratio is less than 85%. | Study on the Increased Enthalpy of Loss Product on Heat Leak into Cryogenic Vessels | 10.1007/978-981-99-6128-3_66 |
2023-01-01 | The Beijing Electron-Positron Collider II (BEPCII) cryogenic system was officially put into operation in January, 2006, including cooled for two superconducting radio frequency (SRF) cavities, two superconducting (SC) quadrupole magnets, and one detector solenoid magnet. To achieve a higher luminosity at higher energy, the BEPCII upgrade (BEPCII-U) was proposed and approved in June 2021, and the core purpose is to improve the efficiency of collision data acquisition in the high energy range and to increase the colliding beam energy from 2.1 GeV to 2.8 GeV. According to the operation requirements of SRF cavities and SC magnets for BEPCII-U, cooling capacity of BEPCII-U cryogenic plant for SRF cavities is upgraded from the original 500 W to 1 kW at 4.5 K due to the increased number of SRF cavities (4 cavities), and two cryostats with current leads for SC magnets are optimally designed. In this paper, the overview of the preliminary design of the BEPCII upgrade cryogenic system is described. | Preliminary Design of the BEPCII-Upgrade Cryogenic System | 10.1007/978-981-99-6128-3_38 |
2023-01-01 | For space application, it is important to study energy efficiency of the helium Joule-Thomson cryocooler (JTC) under different operating parameters. The operating parameters affect not only the cooling capacity of the JTC, but also the power consumption of the pre-cooler and JT compressors. Based on the actual performance of the precooler and the JT compressors, the influence of the operating parameters on the total power consumption of the JTC is revealed. There exists an optimum secondary precooling temperature and an optimum high-pressure that makes the JTC to achieve the same cooling performance target with the lowest power consumption and highest energy efficiency. Then, with a cooling capacity more than 100 mW as the cooling capacity target, an experimental study of a two-stage pulse tube precooling helium JTC is carried out. With the input power of the precooler is 376 W and the JT compressor unit is 156 W, the JTC can obtain a cooling performance of 110mW @ 4.0 K within 20 h. Meanwhile, a multistage cooling capacity tests of the JTC are also carried out to obtain a cooling capacity of 70 mW @ 4.0 K and 200 mW @ 20 K. | Study of a Two-Stage Pulse Tube Precooling Helium Joule-Thomson Cryocooler | 10.1007/978-981-99-6128-3_88 |
2023-01-01 | Abstract The results of the quantum-mechanical study of the one-step acetone transformation to 1-propen-2-ol in the solid phase under deep space conditions are presented. The study explicitly considers the involvement of additional water molecules in isomerization, which simulates the solid phase conditions within the SCRF//PCM approach. This leads to a decrease in the barrier height of 65.6 kcal/mol corresponding to the gas-phase transition approximately by half. It is shown that its energy is minimum with the involvement of three additional water molecules in the transition state. | Isomerization of Acetone into 1-Propen-2-ol in Interstellar Ices | 10.3103/S1068335623010050 |
2023-01-01 | The volatile organic compounds (VOCs) are important precursors of ozone and PM2.5. VOCs emission reduction plays an important role in carbon emission and environmental protection. For high-value VOCs such as organic solvents, the cryogenic condensation using liquid nitrogen is an effective VOCs recovery method that can satisfy the emission standard with a low refrigeration temperature of −180 ℃ or even lower. In this paper, in order to explore the VOCs condensation and frosting in the heat exchanger for improving the heat transfer efficiency, a set of visualization experimental equipment for VOCs condensation recovery based on liquid nitrogen cooling was designed, established, and tested. Several windows are set on the heat exchanger shell to observe the process of condensation and even frosting inside the heat exchanger and the distribution of liquid film and frost layer. Experiments and analyses were carried out under different working conditions such as the effect of VOCs concentration, gas flowrate, refrigeration temperature, and other influencing factors. | Experimental Study on Condensation Characteristics of Volatile Organic Compounds | 10.1007/978-981-99-6128-3_69 |
2023-01-01 | At present, Ultra-high field MRI system is considered the right way to explore the human brain because of the brain activity would be seen at a resolution of hundreds of micrometers. In 2017, the Chinese government launched an ambitious project to design and manufacture a 14T MRI system to support neuroscience research in future. The superconducting magnets made of Nb_3Sn superconductor and NbTi superconductor is designed to generate a homogeneous field of 14 T with a warm bore of 900 mm. In order to ensure the magnet could be operated safely and stability with a higher temperature margin, the superconducting magnet system include a main coil made of Nb_3Sn superconductor and shielding coils made of NbTi superconductor which will be immersed and cooled by the sub-cooled helium. In this paper, the concept design of the low-temperature structural and the cryogenic system will be introduced. | Conceptual Cooling Design for 14T MRI Superconducting Magnet System | 10.1007/978-981-99-6128-3_134 |
2023-01-01 | For testing tensile properties of materials at cryogenic temperature, it is important to create a cryogenic environment. In this study, a cryogenic system has been designed and established for testing tensile properties of micro-sized materials. A pulse tube cryocooler (PTC) is used as cold source. The temperature of the sample can be controlled and maintained within range from 300 K and 77 K. The volume and weight of the system is only about 0.5 m^3 and 25 kg respectively. First, for testing micro-sized materials, the structure of the system is designed, which consists of the cooling system, the mechanical testing system and the data collection system. And then the heat leakage of the system is calculated and analyzed. According to the optimal result of simulated calculation, the cryocooler with the cooling capacity of 3 W at 77 K was selected as the cold source of the system. Finally, the experiments are performed on testing the cooling performance of this system by the controlling system, including the cooling process of the PTC and the sample chamber. The results show that the lowest temperatures of the cold end are 50 K and 63 K respectively within no-load cooling and mechanical module assembled cooling, which is proved that the system can test tensile properties of the micro-sized sample from 77 K to 300 K. | Cryogenic System Based on a Pulse Tube Cryocooler for Testing Tensile Properties of Micro-Sized Materials | 10.1007/978-981-99-6128-3_138 |
2023-01-01 | The article assessed the feasibility of using the developed physical-mathematical model to calculate the emergency process in a cryogenic double-shell tank for low-tonnage LNG storage and transportation. The model was tested using liquid nitrogen (without insulation in the annular space) and LNG (with powder insulation filling the annular space); the results confirmed the reliability of the proposed method for calculating the transition process parameters in a cryogenic double-shell tank. | Test Results of a Non-Isothermal Cryogenic Double-Shell Reservoir for LNG Storage and Transportation | 10.1007/s10556-023-01170-z |
2023-01-01 | The Dalian Advanced Light Source (DALS), proposed by Dalian Institute of Chemical Physics (DICP), is a linear accelerator based on continuous wave superconducting radio frequency technology aiming to produce high-quality electron beam with repetition rate up to 1 MHz. Before the project is officially implemented, a DALS test facility (DATF) is under construction to qualify the performance of the key components, including the superconducting cavities and the cryomodules. A cryogenic system is designed to provide the cooling capacities for the DATF. The DATF is mainly composed of Horizontal Test Bench (HTB), Vertical Test Cryostat (VTC), Cryogenic Test Bench (CTB) and Injector Test Bench (ITB). The overall objective of cryogenic control system is basically a distributed system to guarantee the control and monitoring of the test facility. The system is mainly composed of Programmable Logic Controllers (PLCs) with local human machine interfaces (HMIs) and the Experimental Physics and Industrial Controls System (EPICS), it contains a total of seven control cabinets that can complete the functions of data acquisition and transmission, regulation/discrete/sequential control, monitoring layer operation, alarm display, data storage and login management of all important equipment. This paper reports on the architecture design and current progress of the control system of the DATF cryogenic system. | Architecture Design of Control System for the DALS Test Facility Cryogenic System | 10.1007/978-981-99-6128-3_130 |
2023-01-01 | The Circular Electron Positron Collider (CEPC), with the low Higgs mass of 125 GeV as a Higgs Factory, has the advantage of a higher luminosity-to-cost ratio and the potential to be upgraded to a proton-proton collider to reach unprecedented high energies and discover new physics. The Technical Design Report (TDR) of CEPC has begun from 2018. This paper focuses on the design and optimization of the CEPC cryogenic system, which are summarized and progressed as follows: (1) For the CEPC superconducting cavity cryogenic system side, the cooling scheme of the superconducting radio frequency (SRF) cryomodules of both the booster and collider has been modified from parallel to series to improve the cavity performance while reducing cost. The design of both cryomodules has been reviewed and improved based on the growing experience of the IHEP cryogenics group. Prototypes for booster and collider have been built in collaboration with the domestic qualified companies and has been tested in the Platform of Advanced Photon Source (PAPS) infrastructure with the aim of further improvements. (2) The new design of the superconducting (SC) magnet cryogenic system, following the progress of a multiple technology strategy under development for the interaction region (IR) magnets, with normal-conducting sextuples. The choice of using large refrigerators for operational stability and cost was appreciated. All in all, further TDR design is going on. Every member needs to work together to greatly push forward the work and complete the TDR design on time. | The Design Consideration and Optimization for the CEPC Cryogenic System | 10.1007/978-981-99-6128-3_5 |
2023-01-01 | The capillary-driven flow in the interior corners is crucial for cryogenic propellant management under microgravity. However, interior corner flow is difficult for cryogenic fluids due to low surface tension. In this study, the capillary-driven flow of liquid nitrogen in an interior corner with microstructure was simulated based on the Volume-of-Fluid method. Flow patterns of the interior corner with and without microchannels were comprehensively studied. The effects of microstructures’ width and depth were studied to reveal their impacts on flow behavior. The results show that the rational design of the microstructures effectively promotes the mass flow rate compared with the pure interior corner. This study provides insights into the flow physics of the interior corner with microstructures and a framework to optimally design related devices. | Computations of Capillary-Driven Cryogenic Flows in the Interior Corner with Microstructures | 10.1007/978-981-99-6128-3_115 |
2023-01-01 | Since the superconducting single-flux-quantum (SFQ) circuit chip is very sensitive to the magnetism, the magnetic shielding becomes important for reducing the interference of the environment magnetic shield on the test. To improve the structural compact and reduce the cost, it is economical to add a cryogenic shield just around the chip in the liquid helium. In order to study the influence of the structure factors on the shielding effectiveness (SE), a simulation model was built to analyze the performance of shields with different structures in a static magnetic field. The factors included the layer number and the open hole size. The combination of the cryogenic permalloy shield and superconducting shield was also discussed based on the calculation. The analysis presented in this study is valuable for the actual design of magnetic shields used for testing SFQ chips in a liquid helium cryostat. | Analysis of the Shielding Effectiveness of Cryogenic Magnetic Shields Used for Testing Superconducting Single-Flux-Quantum Circuit Chips | 10.1007/978-981-99-6128-3_139 |
2023-01-01 | PIRENEA and PIRENEA 2 are experimental setups dedicated to the study of fundamental molecular processes involving species of astrochemical interest. The coupling of a VUV source to PIRENEA has allowed us to study the fragmentation pathways and stability of polycyclic aromatic hydrocarbons (PAHs) containing aliphatic bonds under conditions relevant for astrophysical photodissociation regions. PIRENEA 2 will open the possibility to extend these studies to larger systems such as PAH clusters, and more generally to study gas-nanograin-photon interactions. | Studying the Interaction Between VUV Photons and PAHs in Relevant Astrophysical Conditions | 10.1007/978-3-031-29003-9_27 |
2023-01-01 | In the context of HL-LHC project, the duty of the existing LHC helium refrigerators will face an increase of beam induced heat loads in the arcs. The cryogenic sectors around the LHC Point 4 (P 4), are considered in priority since the respective refrigerators must cover in addition to the superconducting (sc) magnetic system the sc Radio Frequency (SRF) cavities. Initial studies demonstrated that the upgrade of one of the existing two cryoplants at P 4 would prevent adding a third new refrigerator as foreseen in the baseline scenario. Complementary studies demonstrated that only one helium refrigerator delivered in 1993 by Linde Kryotechnik® needed to be upgraded, representing a particular challenge as it had already been modified twice to match the LEP 200 and the LHC project requirements. This paper will present the upgrade of ex-LEP helium refrigerator, located at LHC P 4 with split cold boxes (surface and underground) emphasizing the challenges to obtain the required additional refrigeration capacity equivalent to 2 kW@4.5 K with respect to the existing plant capacity of 16.5 kW@4.5 K. The major action has been to integrate and replace all expansion turbines using new state-of-the-art turbines, while verifying existing equipment manufactured since the nineties. The constraints, singularities of each surface and underground cold boxes and project risks assessment led to different technical solutions for the integration of the new turbines will be described. The performance obtained for the upgraded ex-LEP refrigerator will be presented as well as 18 months of operation facts with cool-down of the corresponding LHC sector and preparation for beams. | Upgrade of the Ex-LEP Helium Refrigerator for HL-LHC at CERN LHC Point 4 | 10.1007/978-981-99-6128-3_7 |
2023-01-01 | In this paper, a set of dry vacuum pumps suitable for superfluid helium cryogenic refrigerator are investigated. Process flow diagram and three-dimension diagram of superfluid helium cryogenic refrigerator is designed. As the core parts of the superfluid helium cryogenic system, the control strategies including one Set-point and Upper & Lower limit, variable frequency regulation and failure protection of the circulating dry vacuum pumps are discussed in details. Helium mass flow rate versus suction pressure and pump motor speed with multi-vacuum pump is tested, respectively. When the suction pressure is 400 mbar the discharge pressure is 1100 mbar, the maximal mass flow rate is up to 39 g/s by multi-vacuum pump (MVP) and variable frequency drive (VFD) of motor from 45 to 65 Hz. This set of dry vacuum pumps can satisfy the boundary conditions of superfluid helium cryogenic system to achieve the cooling capacity of 510.6 W @ 1.97 K, which is originally self-developed in China. | Investigation on Dry Vacuum Pumps Suitable for Superfluid Helium Cryogenic Refrigeration | 10.1007/978-981-99-6128-3_10 |
2023-01-01 | The Indian Space Research Organisation (ISRO) envisaged a launch vehicle to put 4 ton class satellites to Geosynchronous Transfer Orbit (GTO). GTO is Geosynchronous Transfer Orbit of 170 km perigee and 35,975 km apogee, where the satellites are injected. It is further raised to the Geostationary orbit by firing satellite thrusters. The upper stage of this launch vehicle is powered by a cryogenic engine of 200 kN nominal thrust working in gas generator cycle using liquid hydrogen (LH_2) and liquid oxygen (LOX) as propellants. The engine has independent LOX and LH_2 turbopumps, with their turbines operating in series mode. The turbopumps were successfully developed through a series of development tests, which included subsystem level tests for pumps, turbines, bearings and seals with simulated fluids. Subsequently, tests were carried out in the turbopump level with different pump fluids like water, liquid nitrogen, liquid oxygen and liquid hydrogen. Finally, tests were carried out in closed-loop mode (boot-strap) with gas generator and turbopumps operating together. The successful completion of these tests demonstrated the design validity of these turbopumps. Subsequently, turbopumps have undergone flight duration and extended flight duration tests as part of engine. The third development engine was used in the successful flight testing of the launch vehicle in 2017. The efforts towards the development of turbopumps are detailed in this paper. | The Development of Turbopumps for Low-Thrust Cryogenic Rocket Engine | 10.1007/978-981-16-9057-0_16 |
2023-01-01 | Thermoelectric materials are attractive for the reversible conversion between heat and electrical energy. Bulk PbSe_0.9Te_0.1 were prepared by two processes. The electrical conductivity, Seebeck coefficients and thermal conductivity of two samples prepared by different techniques were investigated in the temperature range from 15 K to 300 K. The phase was analyzed by XRD and the microstructure was observed by SEM. The obtained results showed that the unannealed sample exhibited the optimal thermoelectric properties. | Thermoelectric Properties of PbSe_0.9Te_0.1 at Cryogenic Temperature | 10.1007/978-981-99-6128-3_143 |
2023-01-01 | Long-wave infrared detectors operate at 60 K, which needs to be obtained by mechanical cryocooler. To maintain the long-term stable operation of long-wave infrared detectors, a cryogenic system with excellent performance is essential. Thus, research on a 60K cryogenic system based on a single-stage pulse tube cooler is carried out in this paper, and the performance optimization of a single-stage pulse tube cooler and heat transfer link is accomplished by means of theoretical analysis and experimental tests. Eventually, the cryogenic system with a single-stage pulse tube cooler provides a refrigeration capacity of above 5.5 W at 60 K on the cold plate, and measures of heat transfer augmentation and heat leakage suppression are verified. | Studies on a 60K Cryogenic System Based on Single-Stage Pulse Tube Cooler | 10.1007/978-981-99-6128-3_120 |
2023-01-01 | The 1.8 K–300 K sub-atmospheric helium heating device is an important component of 1.8 K cryogenic test platform. The process design of the 1.8 K–300 K sub-atmospheric helium heating device is completed. A three-dimensional model is established, and numerical simulation of flow and heat transfer characteristics is studied by CFD software. Physical properties of helium used in the simulation adopt the interpolation method to call HEPAK, and SST k-ω turbulence model is adopted for simulation. The simulation results show that the outlet temperature of the 1.8 K–300 K sub-atmospheric helium heating device can reach 289.56 K which is close to room temperature when the heating power is 9 kW, and the pressure drop of helium gas is 7.6 Pa which is far less than the maximum pressure drop restriction (50 Pa@6 g/s). The simulation results show that the design of the 1.8 K–300 K sub-atmospheric helium heating device can meet the engineering requirements. | Numerical Simulation of 1.8 K–300 K Sub-Atmospheric Helium Heating Device | 10.1007/978-981-99-6128-3_41 |
2023-01-01 | Cryogenic propellant will play an important role in the future aerospace field because of its superior properties. The zero boil off (ZBO) storage of cryogenic propellant is the key of its long-term on orbit storage. Variable density multilayer insulation material (VDMLI) is one of the effective passive thermal protection technologies for cryogenic propellant storage tanks. The theoretical and experimental study on the thermal performance of VDMLI can provide reliable guarantee for its practical engineering application. A concentric cylindrical calorimeter is designed and built to measure the thermal performance of the VDMLI at low temperature. The effects of cold boundary temperature on the performance of the VDMLI have been analyzed. According to the layer by layer model, the theoretical model of the VDMLI is established to predict the thermal performance of the VDMLI, and it has been verified by experiments. | Experimental and Theoretical Study of Variable Density Multilayer Insulation (VDMLI) at Different Cold Boundary Temperatures | 10.1007/978-981-99-6128-3_62 |
2023-01-01 | At the European Spallation Source (ESS), a 2.0 GeV proton Linear Accelerator (LINAC) is under construction, which contains 43 cryomodules operating at 2 K. The Accelerator Cryoplant (ACCP) will provide helium cooling to the cryomodules in the LINAC at different temperature levels. The cryogenic distribution system (CDS) connects the cryomodules and ACCP by means of valve boxes and cryogenic multi-transfer lines. The ACCP successfully passed the last acceptance tests in September, 2020. In order to test the performance of CDS, an integrated test of ACCP and CDS without cryomodules connected will be performed in 2022. This paper describes two different series of test cases developed for the ACCP-CDS assembly, one to be conducted at 8K feed temperature and over-atmospheric pressure to determine the CDS heat load and the other at 2 K equivalent sub-atmospheric conditions with the cold compressors (CCs) in operation to check their performance with the CDS attached. The new developed control logic, limitations and the interface parameters will be discussed. | Preparation and Preliminary Test on the Integrated Test of the Accelerator Cryoplant and the Cryogenic Distribution System at ESS | 10.1007/978-981-99-6128-3_21 |
2023-01-01 | The insulating material is a crucial part of superconducting magnets and the dielectric mechanisms of insulating materials are still unclear at cryogenic temperatures. Space charge distribution can partially characterize the dielectric properties of materials. Thermally stimulated currents (TSC) method was adopted to analyze space charge distribution in many cases. In this paper, a cryogenic system for measuring space charge characteristics has been established based on the thermally stimulated currents theory. Besides, a measurement and control system was designed. The whole system contained many good traits. Microscopic parameters of charged particles in various materials can be tested in the platform, especially for the measurement of defect state density distribution of insulating dielectrics. A thermal and reliability experiment of the TSC test platform was carried out. The experiment verified the reliability of the whole experimental system. | A Cryogenic System for Measuring the Thermally Stimulated Depolarization Current | 10.1007/978-981-99-6128-3_50 |
2023-01-01 | This paper focuses on the 1kw/4.5K helium refrigerator applied to Central Solenoid Model Coil (CSMC) test magnets under the Comprehensive Research Facility for Fusion Technology (CRAFT). The structure of CSMC and the process of cryogenic distribution system are briefly introduced. It mainly introduces the design of the control system under the CODAC (COntrol, Data Access and Communication) architecture through the analysis of the specific operation conditions required for testing the magnets including of the redundant control network, interlock function, and communication configuration and OPI (Operator Interface), etc. Through structural analysis and research on typical cryogenic applications, the purpose is to standardize cryogenic control logic design and program development, and improve the readability, scalability and maintainability of large-scale programs. System commissioning is scheduled to begin in July 2022. | Helium Cryogenic Control System Design for CSMC Testing in CRAFT | 10.1007/978-981-99-6128-3_132 |
2023-01-01 | Cryogenic pulsating heat pipe (PHP) is a novel heat transfer unit with unique working mechanism. The advantages of high heat transfer efficiency and strong environmental adaptability make them as desirable means for thermal management in cryogenic applications such as cooling superconductors. In this present paper, a nitrogen-based PHP composed of 4 parallel stainless steel tubes was experimentally studied. The PHP was operated in vertical orientation where the evaporator was at the bottom position, and the lengths of the evaporator, condenser and adiabatic section were 50 mm, 50 mm and 100 mm, respectively. The inner diameter of the pipe was 1mm and the outer diameter was 1.59 mm (1/16 inch). Experiments at three fill rates of 50%, 70% and 90% were performed and the heat transfer performance of nitrogen-based PHP was investigated under various working conditions by changing heat loads and fill ratios. | Effect of Fill Ratios on the Heat Transfer Performance of Nitrogen Cryogenic Pulsating Heat Pipe | 10.1007/978-981-99-6128-3_63 |
2023-01-01 | GeV-class proton beam with an average power of several megawatts have many important applications in particle physics towards the intensity frontier, as well as in the advanced energy, and material science. In 2019, China Institute of Atomic Energy (CIAE) proposed an isochronous FFAG conceptual design with capability of producing 2GeV/6MW CW proton beam. The high temperature superconducting magnets are adopted in the 2GeV/6MW FFAG design and are briefly introduced in this paper. The heat loads of superconducting magnets are analyzed by theoretical analysis method. Then, the centralized refrigeration scheme and distributed refrigeration scheme are analyzed and compared by numerical simulation method. Based on that, suggestions for further engineering design are outlined. | Simulation and Analysis of Cryogenic System for FFAG Superconducting Magnets | 10.1007/978-981-99-6128-3_148 |
2023-01-01 | So far, we have focused on fusion in plasmas that are confined by magnetic fields. Those approaches aim to maximize the time interval in which fusion can occur. Other important parameters are plasma temperature and density. Higher temperature makes fusion more likely when nuclei collide, and higher density means that more fusion events can occur in a given volume. But there are trade-offs among those parameters. This chapter looks at an approach that produces much higher temperatures and densities but for a much shorter time. Rather than trying to confine the plasma by a magnetic field, this approach begins with a very cold pellet of solid deuterium and tritium and blasts it with high-energy pulsed lasers or particle beams that implode it, suddenly creating an extremely hot, dense plasma in which fusion events occur rapidly. Without a magnetic field to confine it, the plasma soon blows itself apart, but not before its fusing nuclei produce a powerful pulse of energy. Their natural inertia sends the nuclei inward at first, creating a plasma with very high temperature and density, and keeps them close together long enough for fusion to occur, hence the name inertial confinement fusion (ICF). Of all the programs discussed in this book, the ICF effort is the most closely associated with the United States’ development of thermonuclear weapons. In fact, it developed from a classified 1960s US program to mimic the operation of such a weapon on a laboratory scale. Over the past 60 years, the United States research community has spent tens of billions of dollars on ICF, including developing modular, cost-effective hardware for power plants. In our view, the ICF program can be considered a jewel of the American research community, producing the nation’s best weapons for scientists and laser technology and driving high-performance computing. | Inertial Confinement Fusion | 10.1007/978-3-031-22906-0_8 |
2023-01-01 | Motors with high temperature superconducting windings are often designed to be ‘air-cored’ in order to maximise the magnetic fields that can be developed. In these cases, structural materials are required that are both electrically non-conducting and perform well at cryogenic temperatures. Powder-filled polymers are a class of materials that offers a promising range of physical properties and cryogenic performance. Considering the complex shapes of the structural components of these motors, suitable manufacturing methods need to be explored along with the alternative materials options. Additive manufacturing (AM) methods are flexible and allow for complex shapes to be achieved that can reduce weight and improve functionality. However, data on AM structural materials at cryogenic temperatures are limited, as is knowledge of practical process conditions to achieve desirable performance attributes for these materials. In this study, selected mechanical properties of AM nylon composite materials reinforced with glass and mineral fillers have been measured at a range of temperatures from 77K to 295K. Short-beam dynamic tests, as well as tensile tests have been conducted on test coupons manufactured using selective laser sintering (SLS) machines as well as the process prototyping platform at Auckland University of Technology. The effect of build orientation, filler quantity and fill material have been investigated and insights into the material suitability for cryogenic applications discussed. | Mechanical Characterisation of Additively Processed Filled Nylon Powder Composites Under Cryogenic Conditions | 10.1007/978-981-99-6128-3_140 |
2023-01-01 | A new project called Dalian Advanced Light Source (DALS) is proposed by the Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences (CAS) and is subject to Chinese central government’s approval. To test SRF cavities and accelerator cryomodules, a series of test benches, including horizontal test bench (HTB), vertical test cryostat (VTC), injector test bench (ITB) and cryogenic test bench (CTB), are under construction in Dalian, China. The dedicated test facility cryoplant (TFCP) will provide cooling power for test benches through the test facility distribution box (TFDB). The cooling capacity of the TFCP is 370W@2 K. Amongst those key issues for the entire system, like reliability, efficiency, process arrangement as well as auxiliary design, top priority has been given to the safety relief system. Such a system shall be able to handle emergency scenarios include but not limited to degradation or sudden loss of vacuum, runaway fill, pipe rupture and rapid energy dissipation in cold helium. In this paper, safety relief solutions for DALS test facility cryogenic system have been introduced and evaluated. Sudden loss of vacuum to air will be viewed as the worst case during the sizing phase, to deter the niobium cavities from danger of over-design pressure, there also equips a decompression system for safety relief. | Safety Relief System Design for the DALS Test Facility Cryogenic System | 10.1007/978-981-99-6128-3_6 |
2023-01-01 | The paper studies a new method of honing with preliminary cryogenic treatment that improves the quality of the machined surface of products from low-carbon steels. The relevance of this paper deals with finding new methods and improving the technology of the honing process aimed at maintaining high accuracy in the geometric shape and the required micro-relief of the machined surface. Based on this, the paper is devoted to the study of a new method of honing with preliminary cryogenic treatment, which improves the quality of the processed surface of low-carbon steel products. In the paper, the authors substantiated the effect of hardness, wear resistance, and strength of the machined surface on the surface quality of austenitic and pearlitic steels. In addition, the micro-profile of the surface was studied after machining stainless steel 12X18H10T by the conventional method of honing and honing with preliminary cryogenic treatment was studied. The novelty lies in the proposal of a new method for changing the structure of the workpiece material in order to increase the quality of the surface of a product made of steels 12X18H10T and 09Г2C. The expediency consists in the publication of new scientific regularities in honing with preliminary cryogenic treatment. The paper can be useful both for employees of educational institutions and engineers of research-and-production and service centers. | Studying the Process of Honing with Preliminary Cryogenic Treatment of Products from Low-Carbon Steels | 10.1007/978-3-031-14125-6_92 |
2023-01-01 | Magnetic bearing has been gradually applied to the field of cryogenics because of its advantages. And a large number of literatures has been accumulated in this field. In this paper, the application of magnetic bearing in cryogenics field is analyzed based on Bibliometric Method for the first time, and the knowledge map is drawn by CiteSpace and VOSviewer visualization software. The development of this field is analyzed, and the research hotspots and important research forces in this field are found. The analysis results have important reference value for grasping the future research direction in this field and promoting the wider application of magnetic bearings in the field of cryogenics. | Bibliometric Analysis on the Application of Magnetic Bearing in the Field of Cryogenics | 10.1007/978-981-99-6128-3_45 |
2023-01-01 | In aerospace applications, Iron-Nickel (Fe–Ni) alloys are first choice of structural designers, whenever high strength and low thermal expansion are required for spacecraft subsystems. Fe–Ni alloy have an extraordinarily minimum thermal expansion, and dimensions were nearly invariable even at cryogenic temperatures, popularly it is called Invar. This alloy is used as a structural component in optical payloads and accelerometer in spacecraft systems. For enhancing the thermal conductivity of Fe–Ni alloys, Cobalt and Silver elements were added to alloy. Cobalt added in Invar alloy called as Kovar, whereas if silver is added, then it is called Silvar. Kovar acts as sealing alloys in space applications specific to commutation satellites. This paper highlights on the estimation of thermal properties and chemical constituents of Fe–Ni alloys. Study reveals that, Invar has 64.271% of Fe, 35.15% of Ni and total 0.608% of other constituents. As the temperature increases from −150 to 200 °C, thermal conductivity of Invar increased from the 12.567 to 18.420 W/(m K). Thermal conductivity of Fe–Ni alloy is enhanced up to 21.454 W/(m K) by addition of 17% Cobalt, whereas addition of 32.2% of silver will enhance the thermal conductivity up to 51.084 W/(m K). For Invar, mean coefficient of thermal expansion (CTE) of 1.998 ppm/°C observed for 150 °C to 200 °C temperature range while in case of Kovar and Silvar alloy, mean CTE enhances up to 7.018 ppm/°C and 6.928 ppm/°C, respectively. Current study provides the valuable thermal data at sub-ambient and higher cryogenic temperature for thermal design of systems. | Thermo-chemical Characterisation of Fe–Ni Alloys for Space Applications | 10.1007/978-981-19-4918-0_2 |
2023-01-01 | This chapter is focused on imaging of viruses and viral vectors individually or in the context of cells and tissue. Common preparation techniques performed at room temperature or in cryogenic conditions for electron microscopy are summarized. Additional topics about instrumentation, data processing, correlative light and electron microscopy, selected applications, and future perspectives are included. | Methods and Practical Considerations in Imaging Viral Therapeutics | 10.1007/978-3-031-28489-2_14 |
2023-01-01 | Among the mechanisms aimed at improving the body’s adaptive capacity during acclimatization is ensuring the adequacy of metabolic processes by optimizing the diet. The research provided the basis for the development of recipes for prophylactic products with a targeted effect based on vegetable raw materials (vegetables, cereals, berries, fruits). For their processing we used a modern technology – processing in deep cold conditions (cryogenic processing). Evidence is provided for the preventive effectiveness of multicomponent products capable of improving adaptation mechanisms in extreme weather and climatic conditions. | Non-specific Prevention of Pre-disease States and Diseases When Adapting to a Maritime Climate | 10.1007/978-3-031-30951-9_6 |
2023-01-01 | Liquid nitrogen/tetrafluoromethane (LN $$_2$$ /CF $$_4$$ ) mixture with a wide liquefied temperature range of 50 to 100 K might be a promising coolant for high- $$T_\textrm{c}$$ superconducting (HTS) apparatus. However, certain features have not yet been clarified before further application, particularly the insulation properties regarding the composite insulation system consisting of such a cryogenic mixture and polypropylene laminated paper (PPLP). In this paper, AC and DC breakdown experiments and simulations of LN $$_2$$ /CF $$_4$$ - PPLP composite insulation system are carried out with various molar fractions of each constituent part taken into account using sample cables insulated by the foregoing composite insulation. Results indicate that such a mixture/PPLP composite insulation system possess a superior breakdown strength compared to pure LN $$_2$$ /PPLP system; LN $$_2$$ /CF $$_4$$ can therefore be an advantageous choice for HTS power apparatus. | Breakdown Characteristics of Liquid Nitrogen/Tetrafluoromethane/Polypropylene Laminated Paper Insulation System Utilized for Superconducting Energy Pipeline | 10.1007/978-981-99-6128-3_145 |
2023-01-01 | In this paper, we present an empirical model for the bulk electron mobility in Si as a function of doping and temperature, down to the cryogenic range. With regard to lattice scattering, we have proposed an empirical model for the lattice dilation energy as a function of doping, using the data extracted from experimental results of bulk electron mobility at higher temperatures and low doping levels. We have also developed a new model for the ionized impurity scattering time using a novel approach of combining the scattering cross-section and the carrier velocity into a single variable. Finally, the Matthiessen’s rule was applied in order to obtain the net mobility. The results showed an excellent match with the experimental data reported in the literature over a wide range of temperature (20–400 K). Also, when compared to the results of some other classic models, with respect to the same set of experimental data, our results showed a much superior match, particularly in the cryogenic range. Finally, this model can be integrated easily to any of the empirical surface carrier mobility models for MOSFETs. | An Empirical Model for Bulk Electron Mobility in Si at Cryogenic Temperatures | 10.1007/s12633-022-02035-5 |
2023-01-01 | Cryogenic fluids are widely used in industrial, aerospace, and many other scientific applications and systems. In these systems, proper transport, handling and storage of cryogenic fluids are of great importance. Chill-down of a transfer line is a natural consequence of routine cryogenic fluid transfer. The chill down time has its importance as the primary objective is to quickly cool the line, so as to promote homogeneous liquid transfer and/or to continue an ongoing test. The present work is a computational study of cryogenic transfer line chill down using a numerical code written in Matlab backed up by its experimental validation. The experiments were carried out with liquid Nitrogen (LN_2) as the cryogen through a fluid transfer line made of stainless steel. A lumped system analysis in which the liquid cryogen and its vapour in the pipe are considered to flow as lumps of fluid, is used for the prediction of chilldown time and thermodynamic property variations during the transient process. The numerical results show good agreement with the experimental measurements and the predicted chilldown time is close to the field data. The generated code can be extended to predict the chill down parameters for any cryogenic transfer operation by providing the respective fluid and pipeline material properties, and the geometric measurements, along with necessary boundary conditions (thermal & flow) and ambient conditions. | Experimental and Computational Study of Liquid Nitrogen Transfer Line Chilldown | 10.1007/978-981-19-6970-6_57 |
2023-01-01 | A low-noise high-gain large-bandwidth transimpedance amplifier (TIA) for cryogenic scanning tunneling microscope (CryoSTM) is proposed. The TIA connected with the tip-sample component in CryoSTM is called as CryoSTM-TIA. The CryoSTM-TIA has a transimpedance gain of 10 G $$\Omega $$ Ω , a bandwidth of over 100 kHz, and an equivalent input noise current power spectral density less than 4 $$(\text {fA})^2/\text {Hz}$$ ( fA ) 2 / Hz at 100 kHz. The low inherent noise of the CryoSTM-TIA is due to its special design: (1) its pre-amplifier (Pre-Amp) is made of the low-noise cryogenic high electron mobility transistors; (2) the cascode-type configuration for the Pre-Amp is used to avoid Miller effect to reduce its input capacitance $$C_\text {A}$$ C A ; (3) the capacitance of the cable connected the Pre-Amp input to the tip, i.e., $$C_\text {I}$$ C I , is minimized; (4) thermal noise sources, such as the feedback resistor, are placed in the cryogenic zone. Its high gain and large-bandwidth are realized together, due to the application of the frequency compensation in the feedback loop, the reduced $$C_\text {A}$$ C A , and the minimized $$C_\text {I}$$ C I . This apparatus can be used for fast high-energy-resolution measurements of scanning tunneling spectra for low conductivity materials, especially for measuring their scanning tunneling shot noise spectra. | Low-Noise High-Gain Large-Bandwidth Transimpedance Amplifier with Cascode-Type Preamplifier for Cryogenic STM | 10.1007/s10909-022-02855-0 |
2023-01-01 | Thermodynamic vent system (TVS) is a promising approach for controlling pressure propellants in cryogenic tanks under microgravity conditions. Prior simulations for the pressurization of cryogen in the tank with TVS basically treated the liquid as quasi-static by the venting operation. However, experiments showed that the liquid could be superheated during that period. The present work will present a model for the passive TVS for one-dimensional cryogenic tanks. Flash evaporation correlation is adopted for calculating the phase change between the superheated liquid and the vapor. The predicted pressure by the model that considers flash evaporation agrees with the experimental data better than that without considering the flashing phenomenon. The evaporation rates in the cases at different fill levels are compared based on the model. It is found that the flashing has a significant impact on the cycle period and mass mean loss rate prediction. | Modeling of Pressure Reducing in a Cryogenic Tank by a Thermodynamic Vent System Considering Flashing | 10.1007/978-981-99-6128-3_119 |
2023-01-01 | A numerical framework for the simulation of two-phase cryogenic flows under a wide range of pressure conditions is presented in this work. Sub-critical injection and near-vacuum ambient pressure conditions were assessed by numerical simulations. Two different computational approaches have been employed, namely a pressure-based solver complemented by a bubble-dynamics model, as well as a density-based solver utilising real-fluid tabulated data to describe the fluid’s thermodynamic properties. The required thermodynamic-data table has been derived using the Helmholtz Equation of State (EoS) and the specific modelling approach can be applied to near-vacuum, sub-critical or even supercritical injection pressure conditions. The geometries of two single-hole injectors have been considered for investigating the flow and spray formation of liquid oxygen (LOx) and liquid Nitrogen (LN_2). Both numerical approaches were validated against available experimental data. Overall, the comparison of results to experimentally acquired data demonstrates the suitability of the employed methodologies in describing processes such cryogenic flashing-flow expansion, phase-change and flash-induced spray formation. The density-based tabulated thermodynamics approach in particular, can be considered as a complete numerical framework for treating two-phase cryogenic flows using real-fluid properties, for a wide range of conditions without the need for case-related modifications. | Numerical Modelling of Cryogenic Flows Under Near-Vacuum Pressure Conditions | 10.1007/978-3-031-30936-6_12 |
2023-01-01 | Normalizing is a widely used heat treatment process for steel to induce desired mechanical and microstructural properties. In the present investigation, P91 martensitic steel was subjected to normalizing, followed by deep cryogenic soaking (DCS) using a muffle furnace and liquid nitrogen chamber. The specimens were reheated in the temperature range of 980–1150 °C and held isothermally for 10–135 min to homogenize the temperature. It is further subjected to air cooling at room temperature followed by deep cryogenic cooling at a temperature of − 196 °C for a time of 30 min in liquid nitrogen. The volumetric % of retained austenite (RA) envisages a logarithmic inclination with increasing austenitizing time for both “normalized” and “normalized followed by DCS” samples. It is ascribed to the steady reduction in thermal stability of the reversed austenite which was obtained at the elevated temperature during the austenitizing. However, the trend did not show either a constant (after reaching critical condition) or decreasing nature; therefore, it is suggested that the thermal equilibrium was not achieved. The variation in hardness also envisages a logarithmic inclination. The reduction in carbide stability at elevated austenitizing temperature (AT) and extensive recovery at the larger austenitizing time leads to reducing the hardness during the process. | Effect of Normalizing Followed by Deep Cryogenic Soaking on Mechanical Properties of P91 Martensitic Steel | 10.1007/978-981-99-2921-4_4 |