bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the selection method of solid cold energy storage medium for liquid air energy storage
Authors: Guo Luna , Ji Wei , Gao Zhaozhao , Fan Xiaoyu , Hu Jianying , Chen Liubiao , Wang Junjie
Published: June 2022

Liquid air energy storage (LAES) is a promising large-scale energy storage technology. A packed bed cryogenic regenerator was investigated for cold energy storage in the LAES system. As the thermophysical properties of the filling material directly affects the performance of the regenerator, sensitivity analyses of the specific heat capacity and thermal conductivity were carried out. Results show that the thickness of the thermocline in the packed bed can be reduced by increasing the specific heat capacity and decreasing the thermal conductivity. Furthermore, the synergy effect of the specific heat capacity and thermal conductivity on the system was considered. In the case of simultaneous changes of the two parameters, the selection method of the solid material was proposed innovatively, and the feasibility of the method was verified by theoretical calculation of various materials.
Thermodynamic analysis of the non-ideal cryogenic packed bed regenerator for the liquid air energy storage system
Authors: Guo L , Ji W , Gao Z , Fan X , Hu J , Chen L , Wang J
Published: June 2022

Liquid air energy storage (LAES) is one of the most recent technologies introduced for grid-scale energy storage. The cryogenic regenerator, which can greatly affect the system efficiency, is the key component of the system. A non-ideal packed bed regenerator for the LAES system was investigated. The cold energy loss and the axial heat conduction of the packed bed regenerator exist in the intermittent period between the charging and discharging process, which significantly degrades the system performance. With rock particles used as the cold energy storage medium, the axial temperature distributions of the packed bed regenerator with different initial temperatures and intermittent periods were compared. Also, the cold energy loss with different boundary conditions was analysed. The results show that the intermittent period exacerbates the negative impact of the axial heat conduction on the performance of the packed bed, and the thickness of the thermocline decreases as the inlet temperature of the cold end decreases. Moreover, as the cold energy loss increases, the cold energy storage efficiency of the packed bed decreases significantly.
Technical and economic evaluation of a liquid air energy storage system with air precooling for compressor inlet
Authors: Gao Z , Hu J , Ji W , Guo L , Fan X , Guo J , Chen L , Wang J
Published: June 2022

The intensification of carbon emissions and the energy crisis have made the safe and reliable application of renewable energy in the energy supply system significantly urgent. Liquid air energy storage (LAES) system is an effective means to solve the time and space mismatch between energy supply and demand. The LAES has the advantages of no geographical restrictions, high energy storage density and flexible operation, making it available to integrate with other industrial processes. In traditional LAES, the heat generated in the compression process is used to supplement the heat in the expansion process, and the excess heat is dissipated. In this study, the compressor inlet air is cooled by absorption refrigeration cycle to avoid excess compression heat, which reduces the power consumption of the compressor and improves the efficiency of the system. The sensitivity analysis of the ambient temperature and the compressor stages on the system efficiency is performed. Furthermore, a comparative analysis between the absorption refrigeration cycle driven by the waste heat and the compression refrigeration cycle driven by electricity for air precooling of the compressor inlet was carried out, and the system round-trip efficiency, exergy efficiency and initial investment cost was selected as indicators for system evaluation.
Failure analysis of leaks due to cracks in hydrogen transfer lines of ESS cryogenic moderator
Authors: Tatsumoto H , Lyngh D , Arnold P , Segerup M , Tereszkowski P , Beßler Y
Published: June 2022

The ESS cryogenic Moderator System (CMS) has been designed to slow down the high-energy neutrons by means of two hydrogen moderators (to be increased to four in the future) by using forced flow of subcooled liquid hydrogen with a temperature of 17 K at 1.0 MPa. A liquid hydrogen leak is considered the most severe failure for the CMS. A leak scenario from the transfer line to its vacuum envelope through a crack have been analyzed and the expected results will be presented in this paper. An analysis code has been developed and calculated the pressure and temperature changes in the CMS process line and its vacuum envelope. The effect of the crack sizes is clarified. The consequential temperature changes along the vacuum envelope as well as the pressure drops were calculated. The required size of the safety relief device in the hydrogen transfer line and its vacuum envelope have thereby been determined and implemented.
Design of a hydrogen vent line for ESS cryogenic moderator system
Authors: Tatsumoto H , Lyngh D , Arnold P , Segerup M , Tereszkowski P , Beßler Y
Published: June 2022

The ESS cryogenic moderator system (CMS) circulates subcooled liquid hydrogen at 17 K and 1 MPa to remove nuclear heating at two hydrogen moderators. All the hydrogen will be safely released to the atmosphere on the roof top of the Target building through a hydrogen vent line (HVL) with a total length of 36 m. Two-phase hydrogen would flow through the HVL because the hydrogen expands by isenthalpic process. The HVL has been designed to avoid decreasing the wall penetration temperature below 253 K and to be sized big enough to limit the backpressure below the design pressure. One-dimensional transient thermohydraulic analysis code that can treat two-phase flow heat transport behavior has been developed. A natural convection heat transfer from air to the cold surface is considered. In this work, the wall temperature reductions and the pressure drop along the HVL during release of cryogenic hydrogen are analyzed. The size and thickness of the HVL have been verified based on the analysis results.
43+T Grenoble hybrid magnet: Commissioning tests of the current leads and cryogenic satellite producing the pressurized superfluid He at 1.8 K
Authors: Pugnat P , Barbier R , Berriaud C , Boujet T , Graffin P , Grandclément C , Hervieu B , Jousset J , Juster F P , Molinié F , Pelloux M , Pfister R , Ronayette L , Yildiz E
Published: June 2022

The Grenoble Hybrid magnet is a modular platform using resistive and superconducting technologies to produce various continuous high magnetic field and flux configurations for the scientific community. They range from 43 T in 34 mm diameter with 24 MW electrical power to 9 T in 800 mm diameter when the superconducting coil is used alone. Thanks to the ongoing upgrade of the electrical power installation of LNCMI-Grenoble up to 30 MW and possibly to 36 MW, the possibility to increase the total field up to 45-46 T in the near future is foresee and deeply studied. The key design parameters will be briefly recalled including the specifically developed Nb-Ti/Cu conductor, the large bore outsert superconducting coil, the magnet cryostat with its structure including the eddy-current shield, the cryogenic line for the interconnection with the cryogenic satellite and the fully dedicated 150 l/h He liquefaction plant. All components of the hybrid magnet platform have been built, tested and delivered to LNCMI-Grenoble, where integration and assembly are ongoing. The status of the project will be given with focus to the recent commissioning tests of the cryogenic satellite producing the pressurized superfluid He at 1.8 K as well as to the successful powering tests of the specially developed current leads at ultimate current and under fully degraded cooling conditions simulating the worst-case accidental scenario.
The GTLT cryocooler, a low temperature variant of CryoTel® GT
Authors: Kim Yongsu , Mansfield Doug
Published: June 2022

The CryoTel® GT is an integral Stirling cryocooler with 16 W of lift capacity at 77 K with a nominal input power of 240 W. The GT has been a Sunpower legacy product since it was brought to commercialization in 2005. The contact-free operation of the moving components by using Sunpower’s gas bearings technology results in a long lifetime of the cooler, achieving an MTTF of over 200,000 hrs. Typical no-load temperature of GT is around 36 K. Sunpower used an advanced regenerator to improve the performance and was able to provide cooling lift below 35 K. Although the advanced regenerator effectively improved the cooler performance, overall cryocooler cost went up substantially due to the costly special processes and materials for the regenerator. Looking for a cost-effective alternative, Sunpower applied optimization techniques and developed a regenerator design improving its performance at lower temperature. To reduce the conduction loss of the cold finger, an alternative material for stainless steel was selected. Its material cost is a little higher than stainless and the thermal conductivity is between titanium and stainless. It is weldable into the transition using the same methods and geometry as the current stainless cold finger which is a huge benefit. Sunpower built 6 units and achieved an average no-load temperature of 26.5 K, about 9 K colder no-load temperature than standard GT, at the same input power. This low temperature variant of GT is named as GTLT and we are moving to add the GTLT as a commercial product.
Final design of the cryostat for the high luminosity LHC magnets
Authors: Ramos D , Vande Craen A , Prin H , Leclercq Y , Williams L , Struik M , Barlow G , Riu Martinez O , Wong Luis B , Parma V , Savary F , Todesco E
Published: June 2022

The high luminosity LHC project (HL-LHC) aims at increasing proton collisions by a factor of ten whilst extending physics exploitation until 2035. Its performance will rely on new focusing quadrupoles, beam separation dipoles and corrector magnets with large apertures to be installed on both sides of the ATLAS and CMS experiments. A dedicated cryostat design of about 1 m in diameter was developed for operation of these magnets at 1.9 K, comprising the required cryogenic circuits, interconnects, supports, insulation, and instrumentation systems. Six cryostats with various lengths in the range of 8 to 11 m are required on each side of the interaction points to house the triplet magnets, correctors and the first separation dipole. These cryostats will be linked through flexible interconnects to form a continuous vacuum insulation and cryogenic system of about 60 m in length. The second rearmost separation dipole requires a stand-alone cryostat of 15 m in length but nevertheless features common design principles. We present the design of these cryostats, from a conceptual stage towards the final design. Assembly aspects are also addressed, including a modular approach affording flexibility and simplification of the manufacturing and assembly processes.
A cryostat for a 6 T conduction-cooled, no-insulation multi-pancake HTS solenoid
Authors: Barkas J , Zhai Y , Safabakhsh M
Published: June 2022

There is a growing requirement for high-field (>20 T) magnets capable of continuous operation, driven by the needs of both fundamental research and technological advance, particularly in application to an eventual pilot plant for magnetic confinement fusion. Even with HTS windings, such magnets will still require cryogenic cooling, and liquid helium (LHe) immersion, the typical solution to this problem, adds significantly to the operating expenses of such facilities. This reality makes cryogen-free cooling systems a necessity in future high-field magnet systems. The Princeton Plasma Physics Laboratory (PPPL) is exploring conduction-cooling systems of HTS pancake solenoids for a scanning tunneling microscopy (STM) facility at Princeton University, and potentially also for the central solenoid of the Fusion Nuclear Science Facility (FNSF). To these ends, PPPL is designing a cryostat to evaluate the thermal stability of a 5-6 T, 30 double-pancake (DP) REBCO insert coil of 40 mm ID / 70 mm OD, and smaller prototypes, operated in self-field with conduction cooling provided by a 2-stage GM cryocooler. The current design is expected to achieve 1st and 2nd stage temperatures of 44 K and 4-10 K, respectively, with the resistivity of DP-DP solder joints being the principal source of uncertainty in 2nd stage temperature predictions.
Feasibility study of capacitance based quench detection technique for HTS power transmission cables
Authors: Hassan Harris K. , Sagar Pankaj , Singh Gour Abhay , V Rao V.
Published: June 2022

2nd Generation High Temperature Superconducting (2G HTS) tapes are replacing the conventional Low Temperature Superconducting (LTS) wires in various felds of applied superconductivity, especially in the power transmission applications. Transients in the electrical grid can result in the loss of superconductivity leading to thermal runaway. This phenomenon is known as quench. To avoid catastrophic consequences, timely detection of quench is imperative. However, the HTS materials possess a low Normal Zone Propagation Velocity (NZPV) compared to LTS materials during quench. This property combined with a low electromagnetic shielding makes the conventional voltage tap detection technique unreliable for HTS power transmission cables. A capacitance based quench detection technique is proposed and its feasibility is studied. A variation in the permittivity of the cryogenic fuid and the dielectric can be observed in association with the heat generation during faults. This can be refected as the variation in the measured capacitance between cryostat and cable former. In this study, this capacitance is computed using the FEM model of HTS cable operating at various temperatures along with diferent vapour liquid ratios of cryogen. The results of this work can be extended into experiments for quench detection in HTS power transmission cables.
Cryogenic design of the crab cavity modules for the High Luminosity LHC at CERN
Authors: Brodzinski K , Capatina O , Capelli T , Claudet S , Delprat L
Published: June 2022

The High Luminosity Large Hadron Collider (HL-LHC) upgrade is planned to take place during next long shut down of the LHC, starting in 2025. During this period the matching sections of both ATLAS and CMS experiments will be upgraded to allow for increasing collisions rate and more efficient luminosity production. One of the new element which will be introduced to the layout is the beam deflecting RF system so-called as crab cavities. Eight crab cavities modules, operating in superfluid helium, will be installed in this new machine layout. This paper will focus on the cryogenic design solutions adopted and integrated in the crab cavities cryogenic modules. The concept of the cryogenic modules was created in 2012 and evolved over the years with introduced optimizations of the cryogenic local cooling loops and related safety system. Design aspects of the chosen solutions for the first prototype and LHC compatible solution will be discussed. The thermal behavior results from operation on SPS proton beam from the first prototype module will be developed.
Improvement of Magnet and Cavities cooling at Heavy Ion or Rare Isotopes Accelerators due to Application of sub-cooled Superfluid Helium
Authors: Putselyk S
Published: June 2022

Several modern Heavy Ion or Rare Iosotopes Accelerator uses superconducting (sc) cavities for an acceleration of the beam particles. Operation of sc magnets with higher magnetic fields and improved field gradients also leads to a better beam focusing (also called “beam optics”) and improves the overall accelerator compactness. In many accelerators, like XFEL, SNS, LCLS-II, HIE-ISOLDE, ATLAS, ISAC-II/ARIEL, SPIRAL-2, FLASH, Jlab-FEL/ERL, the operation is limited either by cooling capability of sc cavities or refrigeration capacities. In most of the cases, increasing of refrigerator capacities is a challenging task due to available free space or investments, and, therefore, improvement of cavity cooling due to increasing of a quality factor (Q
0) or heat transfer at cavity surfaces is considered. Application of a sub-cooled superfluid (sf) helium gives several advantages, like higher heat flux densities, longer time for onset of a film boiling regime and shorter recovery time, reduced Kapitza resistances, etc. In the present paper, application of sub-cooled superfluid helium for cooling of cavities with half and quarter-wave resonators, which are typically applied at Heavy Ion and Rare Isotopes Accelerators or sometimes at electron and proton ones, is considered. In order to limit the present discussion, its application to FRIB-style cryomodules is discussed in details.
Flow of Neon-Nitrogen-Hydrocarbon mixture through adiabatic capillary tube at cryogenic temperatures
Authors: Parmar Darshit , Atrey M. D.
Published: June 2022

Capillary tubes are widely used in J-T refrigerators owing to their simplicity, easy operation, and zero maintenance. J-T refrigerators are mainly used for domestic and commercial refrigeration and air conditioning and hence the study on flow through capillary tubes is highly focused on conventional refrigerants at relatively higher temperatures. The present work is an extension of previous work done by the authors and focuses on the flow of refrigerant mixtures consisting of neon, nitrogen, and hydrocarbons at cryogenic temperatures for the capillary tube of a J-T cryocooler. The mass flow rate through the capillary tube is studied experimentally by changing refrigerant mixture composition and inlet temperature to the capillary tube. A mathematical model is developed based on a length feedback loop to predict the mass flow rate through the capillary tubes using the homogenous flow model. The model is found to predict mass flow rate through the capillary tube with an average error of 10 % for almost all the experimental values.
Numerical simulation of sinusoidal corrugated fins and serrated fins performance at low temperature
Authors: Zhu Z G , Wang H , Zhang Q Y , Zou Z Y
Published: June 2022

Due to promoting the disturbance of fluid and high heat transfer performance, sinusoidal wavy fins and serrated fins are used in plate fin heat exchangers (PFHE) for cryogenic system. In order to compare their flow and heat transfer performance difference at low temperature, this article adopts the numerical simulation method to investigate the flow and heat transfer characteristics of normal-temperature and low-temperature helium in corrugated wavy fin and serrated fin channels. The influence of different temperature and Reynolds numbers on the fin performance are analyzed. The results can provide theoretical guidance for the optimal design of cryogenic PFHE.
Friction stir welding of AISI 316LN high strength austenitic stainless steel for cryogenic application
Authors: Aviles Santillana I , Debeux J , Meyer M , Muddamallappa M , Polo Picazo A , Robe H , Rodriguez Castro E , Sgobba S , Weiss KP
Published: June 2022

Friction stir welding (FSW) is a solid state joining process that uses the heat generated by the friction of a rotating tool and the base material to join materials together. Due to the fact that the material is never melted, and that extensive plastic deformation is introduced in the weld seam, a unique set of properties is achieved. The technique has been extensively used to join aluminium and aluminium alloys, but very few developments are reported on high strength austenitic stainless steel, which is the material of choice for many high energy physics and fusion magnets. This paper contains a comprehensive microstructural and mechanical characterization, including at cryogenic temperature, of an 8 mm thick high strength austenitic stainless steel plates. The steel grade is the high alloy version of AISI 316LN (identified as 1.4429 or -X2CrNiMoN17-13-3 according to European standards). Special attention was given to cryogenic elastic – plastic J – integral testing of the weld seam. To the authors’ knowledge, this is the first time fracture toughness at cryogenic temperature on friction stir welded 1.4429 has been measured.
Niobium rod quality and its impact on the production of Nb3Sn strand for the Divertor Tokamak Test Facility toroidal coils
Authors: Smathers D. , Flanigan J. , Kim J. , Sim K.
Published: June 2022

Niobium Tin cable is being used in the high field magnets in the Divertor Tokamak Test Facility under construction by ENEA in Italy. Kiswire Advanced Technology was selected to provide 55 tonnes of high-performance Niobium Tin wire for the 18 Toroidal Field Coils. The conductor design is based on a 0.82mm Nb3Sn strand similar to that provided for the ITER TF coils. H. C. Starck Solutions provided the pure Nb rod and Ta sheet for their conductor design. The enhanced strand requirement has both a minimum current (320 A at 12 Tesla) and maximum hysteresis loss (± 3T cycle 1000mJ/cc) and a Cu/Non-Cu of 1:1. To achieve the current and hysteresis loss reliably, the niobium rod must maintain its shape throughout the drawing process. The n value requirement (>20) is a good indication of niobium filament uniformity while the RRR requirement (>100) is a good indication of tantalum barrier performance. The HCSS rod supplied to KAT provided consistently high Ic (>320A at 12 Tesla), low hysteresis loss and the Ta sheet provided very good RRR values. We report here the consistency of more than 11 tonnes of HCSS Nb rod properties for chemistry, hardness, grain size and wire performance.
Neutron irradiation effect on critical current and critical temperature of Nb3Sn wire
Authors: Nishimura Arata , Hishinuma Yoshimitsu
Published: June 2022

The ITER project is ongoing in France, and it is expected that a lot of high energy neutrons will be generated, and some neutrons will reach to superconducting magnets. To keep the safe and stable operation of the superconducting magnets, the neutron irradiation data must be piled up and the mechanisms of the irradiation effect must be investigated. A 15.5 T superconducting magnet and a variable temperature insert were installed in a radiation control area at Oarai centre in Tohoku University, and the superconducting properties of the irradiated Nb3Sn wires have been evaluated. The critical current was improved once and drastically dropped after irradiation of 1023 n/m2, and the critical temperature degraded monotonically, and the critical magnetic field decreased around 17 T after the irradiation of 1023 n/m2. The mechanism of the irradiation effect was discussed based on a flux pinning concept.
3D Modelling and Validation of the Optimal Pitch in Commercial CORC Cables
Authors: Fareed M. U. , Kapolka M. , Robert B. C. , Clegg M. , Ruiz H. S.
Published: June 2022

Conductor on a rounded core (CORC®) cables with current densities beyond 300 A/mm-2 at 4.2 K, and a capacity to retain around 90 % of critical current after bending to a diameter of 3.5 cm, make them a strong candidate for high field power applications and magnets. In this paper, we present a full 3D-FEM model based upon the so-called H-formulation for commercial CORC® cables manufactured by Advanced Conductor Technologies LLC. The model presented consists of tapes ranging from 1 up to 3 SuperPower 4mm-width tapes in 1 single layer and at multiple pitch angles. By varying the twist pitch, local electromagnetic characteristics such as the current density distribution along the length and width are visualized. Measurements of macroscopical quantities such as AC-losses are disclosed in comparison with available experimental measurements. We particularly focused on the influence of the twist pitch by comparing the efficiency and performance of multiple cables, critically assessing the optimal twist pitch angle.
Influence of cooling temperature on load-carrying performance of a radial HTS magnetic bearing
Authors: Guan Xiang , Zou Yincai , Bian Xing , Shang Jin , Wu Jihao , Li Qing
Published: June 2022

High temperature superconducting (HTS) magnetic bearing can operate in the harsh environment of low temperature and negative pressure with low loss and self-stability. Therefore, it has been gradually applied in flywheel energy storage, cryogenic liquid pump, cold compressor and some other cryogenic rotating machinery. The load-carrying performance of HTS magnetic bearing is affected by the cooling temperature of HTS directly. In this paper, the linear model is used to modify the temperature dependence to evaluate the influence of cooling temperature on load-carrying performance quantitatively, and the results are analyzed and displayed from the aspects of maximum levitation force, levitation stiffness and hysteresis effect. The research results of this paper have practical significance for the design and safe operation of HTS levitation system.
Electrical characterization of a 1200V GaN HEMT at cryogenic temperatures
Authors: Hossain Md Maksudul , Wei Yuqi , Rashid Arman-Ur , Sweeting Rosten , Alan Mantooth H.
Published: June 2022

The cryogenic operation of power converters integrated with the superconducting electric machines can leverage the lower parasitic, lower core material, and insulation requirement to reduce weight and increase power density in aerospace applications. To that end, Gallium Nitride High Electron Mobility Transistor (GaN HEMT) has recently proven to be the most viable option for the cryogenic converter operation. However, the topology selection and optimization are greatly influenced by the current/voltage rating of the power devices. Although series connected HEMTs can increase the blocking voltage, the dynamic voltage imbalance issue stemming from device parameter fluctuations, the larger number of required isolated gate driver makes the need for single high blocking voltage devices more compelling. This is even more pronounced in GaN due to its higher operating frequency which stems from the lower input capacitance. Although 900V cascode GaN HEMTs are now commercially available, single-chip high voltage HEMTs are attractive due to their zero reverse recovery charge, and lower package bonding parasitics. In this paper, a 1200V enhancement-mode GaN HEMT from GaNPower International has been characterized at cryogenic temperature. A 63% decrease has been demonstrated in the on-resistance, Rds(on) from room temperature to -150°C. The threshold voltage shows a 1.2x increase from room temperature to cryogenic temperature (-178°C). The transconductance (Gfs) shows a 1.34x increase for a temperature difference of 175°C. The results translate to a lower conduction loss and a faster switching speed and unfold further possibility of GaN in cryogenic converter applications.
LCLS-II-HE Cryomodule Production Status at Fermilab
Authors: Kaluzny J , Arkan T , Bice D , Blowers J , Checchin M , Grimm C , Hartsell B , Martinello M , Nicol T , Posen S , Premo K
Published: June 2022

The Linac Coherent Light Source (LCLS) is an X-ray science facility at SLAC National Accelerator Laboratory. The LCLS-II project (an upgrade to LCLS) is in its final stages, and the LCLS-II-HE (High Energy) project is another upgrade to the facility enabling higher energy operation. An electron beam is accelerated using superconducting radio frequency (SRF) cavities built into cryomodules. It is planned to build twenty-five modules total for the LCLS-II-HE project. Fourteen of these modules are planned to be assembled and tested at Fermilab. Procurements for production modules have been awarded, and parts are arriving. The design of the LCLS-II-HE modules is similar to the module design used in LCLS-II. The major cryomodule design change from LCLS-II is the nominal gradient required per cavity, increasing from 16 to 21 MV/m. The additional gradient yields additional heat loads. The first LCLS-II-HE cryomodule, referred to as the verification cryomodule (vCM), was assembled using parts from an LCLS-II module with new SRF cavities. The assembly is complete, and this module is currently being tested at Fermilab. The vCM cavities perform well, exceeding the required gradient and quality factor specifications. The first article module assembly is planned to start later in 2021. The status of the production as well as some of the design and assembly changes will be presented.
Microwave Characterization of Gamma Ray Irradiated Thin Film Embedded and Non-embedded Nb Resonators
Authors: Yelamanchili Bhargav , Gupta Vaibhav , Zou Simin , Christiansen Robert , Cichon Max C. , Sellers John A. , Park Minseo , Mahjouri-Samani Masoud , Tuckerman David B. , Hamilton Michael C.
Published: June 2022

Gamma radiation effects on superconducting microwave transmission line structures, which may find use in future radiation challenging environments, such as satellites or accelerators have been investigated. Two versions of weakly coupled through-type Nb microstrip transmission line resonator material stack-ups were explored. In one version, the Nb signal trace was encapsulated with 20 µm of HD-4110 and in the other version the top Nb was not encapsulated. Exposure of the resonators to gamma radiation was performed for 28 days at room temperature in a sealed vacuum chamber using Co-60 as the gamma radiation source. The quality factors of the resonators were extracted at various cryogenic temperatures below the critical temperature of Nb and resonant frequencies up to 20 GHz. A large dose of gamma radiation used in this work showed a small change in the Nb superconducting properties.
Genetically encodable fluorescent protein markers in advanced optical imaging
Authors: Nienhaus Karin , Nienhaus Gerd Ulrich
Published: June 2022

Optical fluorescence microscopy plays a pivotal role in the exploration of biological structure and dynamics, especially on live specimens. Progress in the field relies, on the one hand, on technical advances in imaging and data processing and, on the other hand, on progress in fluorescent marker technologies. Among these, genetically encodable fluorescent proteins (FPs) are invaluable tools, as they allow facile labeling of live cells, tissues or organisms, as these produce the FP markers all by themselves after introduction of a suitable gene. Here we cover FP markers from the GFP family of proteins as well as tetrapyrrole-binding proteins, which further complement the FP toolbox in important ways. A broad range of FP variants have been endowed, by using protein engineering, with photophysical properties that are essential for specific fluorescence microscopy techniques, notably those offering nanoscale image resolution. We briefly introduce various advanced imaging methods and show how they utilize the distinct properties of the FP markers in exciting imaging applications, with the aim to guide researchers toward the design of powerful imaging experiments that are optimally suited to address their biological questions.
Open-top light-sheet imaging of CLEAR emulsion for high-throughput loss-free analysis of massive fluorescent droplets
Authors: Jiang Wen , Chen Longbiao , Wang Jie , Shao Xinyang , Jiang Mengcheng , Chen Zitian , Wang Jianbing , Huang Yanyi , Fei Peng
Published: June 2022

Digital droplet PCR (ddPCR) is classified as the third-generation PCR technology that enables absolute quantitative detection of nucleic acid molecules and has become an increasingly powerful tool for clinic diagnosis. We previously established a CLEAR-dPCR technique based on the combination of CLEAR droplets generated by micro-centrifuge-based microtubule arrays (MiCA) and insitu 3D readout by light-sheet fluorescence imaging. This CLEAR-dPCR technique attains very high readout speed and dynamic range. Meanwhile, it is free from sample loss and contamination, showing its advantages over commercial d-PCR technologies. However, a conventional orthogonal light-sheet imaging setup in CLEAR d-PCR cannot image multiple centrifuge tubes, thereby limiting its widespread application to large-scale, high-speed dd-PCR assays. Herein, we propose an in-parallel 3D dd-PCR readout technique based on an open-top light-sheet microscopy setup. This approach can continuously scan multiple centrifuge tubes which contain CLEAR emulsions with highly diverse concentrations, and thus further boost the scale and throughput of our 3D dd-PCR technique.
Diverse densest ternary sphere packings
Authors: Koshoji Ryotaro , Ozaki Taisuke
Published: June 2022

The exploration of the densest structures of multi-sized hard spheres under periodic boundary conditions is a fundamental problem in mathematics and a wide variety of sciences including materials science. We present our exhaustive computational exploration of the densest ternary sphere packings (DTSPs) for 451 radius ratios and 436 compositions on top of our previous study [Koshoji and Ozaki, Phys. Rev. E 104, 024 101 (2021)]. The unbiased exploration by a random structure searching method discovers diverse 22 putative DTSPs, and thereby 60 putative DTSPs are identified in total including the 38 DTSPs discussed by the previous study. Some of the discovered DTSPs are well-ordered, for example, the medium spheres in the (9-7-3) structure are placed in a straight line with comprising the unit cell, and the DTSP has the

Pm

3

¯

m

symmetry if the structural distortion is corrected. At a considerable number of radius ratios, the highest packing fractions are achieved by the phase separations consisting of only the FCC and/or the putative densest binary sphere packings (DBSPs) for all compositions. The trend is becoming more evident as the small and medium spheres are getting larger, which suggests either the binary packings are actually the densest packings or that the dense ternary packings have unit cells larger than those in this study. On the other hand, the number of the DTSPs increase as the particle size of small spheres gets small. The structural diversity indicates that many unknown DTSPs may hide in a very narrow range of radius ratio where the size of small spheres is smaller due to the competition with respect to the packing fractions of many structural candidates. Finally, we discuss the correspondence of the DTSPs with real crystals based on the space group. Our study suggests that the diverse structures of DTSPs can be effectively used as structural prototypes for searching ternary, quaternary, and quinary crystal structures.
Spectroscopic investigation of tau protein conformational changes by static magnetic field exposure
Authors: Darwish Saqer M , Darwish Imtiaz M
Published: June 2022

Electromagnetic fields taint the molecular environment of proteins and induce changes in the central nervous system. This research applied Fourier transform infrared spectroscopic analysis to investigate the effects of static magnetic fields on tau protein in neurological disorders. It explores the conformational changes of tau protein and highlights its’ potential application as a pathological biomarker for early detection and therapeutic interventions. The results indicate that tau protein is susceptible to magnetic field exposure in the amide B, fingerprint, and amide regions (IV-VI). Changes in peak positions and band intensities were identified and delineated as the outcome effect of magnetic forces on molecular vibrations. Magnetic forces may affect the microtubule structure of the tau protein, leading to protein aggregation. These results indicate the potential application of FTIR spectroscopy for the early detection and classification of degenerative diseases through spectrum analysis. Different magnetic fields can be used as spontaneous therapeutic procedures to induce changes in the molecular environment of proteins.
Taguchi’s design optimization for finishing of plane surface with diamond-based sintered magnetic abrasives
Authors: Gill Jagdeep Singh , Singh Palwinder , Singh Lakhvir
Published: June 2022

The magnetic field-assisted abrasive finishing parameters used in this study were the distance of the workpiece from the magnetic pole (D), amount of sintered magnetic abrasives (A), speed of rotation of the pole (R), grain size of the abrasive particles (S) and feed to the workpiece (F). The surface roughness percentage change (SRPC) and material removal rate (MRR) of the plane surface workpiece of aluminum are the response quantities. An orthogonal L16 array of the Taguchi method was constructed and is used in this study to analyze the influence of finishing parameters on the surface roughness percentage change of the workpiece. The analysis of variance (ANOVA) showed the extent to which finishing parameters are important. The experimental results showed that for SRPC, the best combination of levels for the given control factors is the distance of the workpiece from the magnetic pole (D) = 4 mm, the amount of sintered magnetic abrasive (A) = 16 g, the speed of rotation of the pole (R) = 600 rpm, the grain size of the abrasive particles (S) = 175 μm and the feed rate of the workpiece (F) = 1.5 m min−1. For MRR, the best combination of levels for the given control factors is the distance of the workpiece from the magnetic pole (D) = 4 mm, the amount of sintered magnetic abrasive (A) = 16 g, the speed of rotation of the pole (R) = 400 rpm, the grain size of the abrasive particles (S) = 175 μm and the feed rate of the workpiece (F) = 6.0 m min−1. The surface profiles and microscopic images of polished and unpolished workpieces show that the magnetic field-assisted abrasive finishing process is very effective in finishing aluminum surfaces.
MSRCall: a multi-scale deep neural network to basecall Oxford Nanopore sequences
Authors: Yeh Yang-Ming , Lu Yi-Chang
Published: June 2022

Motivation

MinION, a third-generation sequencer from Oxford Nanopore Technologies, is a portable device that can provide long-nucleotide read data in real-time. It primarily aims to deduce the makeup of nucleotide sequences from the ionic current signals generated when passing DNA/RNA fragments through nanopores charged with a voltage difference. To determine nucleotides from measured signals, a translation process known as basecalling is required. However, compared to NGS basecallers, the calling accuracy of MinION still needs to be improved.

Results

In this work, a simple but powerful neural network architecture called multi-scale recurrent caller (MSRCall) is proposed. MSRCall comprises a multi-scale structure, recurrent layers, a fusion block and a connectionist temporal classification decoder. To better identify both short-and long-range dependencies, the recurrent layer is redesigned to capture various time-scale features with a multi-scale structure. The results show that MSRCall outperforms other basecallers in terms of both read and consensus accuracies.

Availability and implementation

MSRCall is available at: https://github.com/d05943006/MSRCall.

Supplementary information

Supplementary data are available at Bioinformatics online.
Actions of WNT family member 5A to regulate characteristics of development of the bovine preimplantation embryo
Authors: Jeensuk Surawich , Ortega M Sofia , Saleem Muhammad , Hawryluk Briana , Scheffler Tracy L , Hansen Peter J
Published: June 2022

WNT signaling is important for regulation of embryonic development. The most abundant WNT gene expressed in the bovine endometrium during the preimplantation period is WNT5A. One objective was to determine whether WNT5A regulates competence of the bovine preimplantation embryo to become a blastocyst and alters the number of cells in the inner cell mass and trophectoderm. A second objective was to delineate features of the cell-signaling mechanisms involved in WNT5A actions. WNT5A caused a concentration-dependent increase in the proportion of embryos developing to the blastocyst stage and in the number of inner cell mass cells in the resultant blastocysts. A concentration of 200 ng/mL was most effective, and a higher concentration of 400 ng/mL was not stimulatory. Bovine serum albumin in culture reduced the magnitude of effects of WNT5A on development to the blastocyst stage. WNT5A affected expression of 173 genes at the morula stage; all were upregulated by WNT5A. Many of the upregulated genes were associated with cell signaling. Actions of WNT5A on development to the blastocyst stage were suppressed by a Rho-associated coiled-coil kinase (ROCK) signaling inhibitor, suggesting that WNT5A acts through Ras homology gene family member A (RhoA)/ROCK signaling. Other experiments indicated that actions of WNT5A are independent of the canonical β-catenin signaling pathway and RAC1/c-Jun N-terminal kinase (JNK) signaling. This is the first report outlining the actions of WNT5A to alter the development of the mammalian embryo. These findings provide insights into how embryokines regulate maternal–embryonic communication.
Polyfunctional Antigen Specific CD4+ T cell Responses in Patients With Human Immunodeficiency Virus/AIDS and Histoplasmosis Immune Reconstitution Inflammatory Syndrome
Authors: Manion Maura , Boulougoura Afroditi , Naqvi Nuha , Lage Silvia Lucena , Richards Elizabeth , Grivas Christopher , Laidlaw Elizabeth , Kuriakose Safia , Ortega-Villa Ana M , Tadros Saber , Roby Gregg , Rupert Adam , Galindo France , Anderson Megan , Pau Alice , Deepe George , Sheikh Virginia , Sereti Irini
Published: June 2022

In the combination antiretroviral era, there are limited data regarding the pathogenesis of histoplasmosis immune reconstitution inflammatory syndrome (IRIS) in people with human immunodeficiency virus (HIV). We immunologically characterized 10 cases of histoplasmosis, 4 of whom developed histoplasmosis IRIS. CD4+ T cells in histoplasmosis IRIS demonstrated a significant polyfunctional cytokine response to histoplasma antigen.
Increased Mortality Among Persons With Symptomatic Coronavirus Disease 2019 (COVID-19) During the Period of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) B.1.617.2 (Delta Variant) Predominance: Alaska, November 2020–October 2021
Authors: Mooring Eric Q , Newell Katherine , Castrodale Louisa , Tompkins Megan , Frank Morgan , McLaughlin Joseph
Published: June 2022

We compared the mortality risk in Alaska among persons with symptomatic coronavirus disease 2019 (COVID-19) during the period the Delta variant was predominant to the risk among those with symptomatic COVID-19 before Delta predominance. The Delta period was associated with 2.43-fold higher odds of death. Unvaccinated persons were 4.49 times more likely to die than fully vaccinated persons.
Analysing region of attraction of load balancing on complex network
Authors: Zou Mengbang , Guo Weisi
Published: June 2022

Many complex engineering systems network together functional elements to balance demand spikes but suffer from stability issues due to cascades. The research challenge is to prove the stability conditions for any arbitrarily large and dynamic network topology with any complex balancing function. Most current analyses linearize the system around fixed equilibrium solutions. This approach is insufficient for dynamic networks with multiple equilibria, for example, with different initial conditions or perturbations. Region of attraction (ROA) estimation is needed in order to ensure that the desirable equilibria are reached. This is challenging because a networked system of non-linear dynamics requires compression to obtain a tractable ROA analysis. Here, we employ master stability-inspired method to reveal that the extreme eigenvalues of the Laplacian are explicitly linked to the ROA. This novel relationship between the ROA and the largest eigenvalue in turn provides a pathway to augmenting the network structure to improve stability. We demonstrate using a case study on how the network with multiple equilibria can be optimized to ensure stability.
‘To settle a governement without somthing of Monarchy in it’: Bulstrode Whitelocke’s Memoirs and the Reinvention of the Interregnum
Authors: Fitzgibbons Jonathan
Published: June 2022

The memoirs of the parliamentarian lawyer and MP Bulstrode Whitelocke are invaluable as a primary source for historians wishing to understand the political history of the 1640s and 1650s. Yet, despite broad recognition of the contentious nature of this material, surprisingly little has been done to establish the accuracy of Whitelocke’s account or to probe the motives behind the writing of his post-Restoration reflections. By focusing on Whitelocke’s recollections of two famous encounters with Oliver Cromwell in 1651 and 1652, this article demonstrates that there is much in the detail of those accounts that fails to convince in the light of what is known of events and the author’s activities from evidence beyond his memoirs. Rather, it seems that the accounts of these meetings were fabricated in order to obfuscate Whitelocke’s activities during the Interregnum period and to propagate a series of narratives that served the author’s purposes as he sought political rehabilitation after the Restoration of 1660. By failing to recognise the memory games at play in Whitelocke’s work, historians have unwittingly embedded many of those same narratives in their accounts of the period, not least concerning the durability of the regime established in 1649 and Cromwell’s kingly ambitions.
Impact of society and national guidelines on patient selection for lung cancer surgery in the United Kingdom
Authors: Pons Aina , De Sousa Paulo , Proli Chiara , Booth Sarah A , Palmares Abigail , Leung Maria , Alshammari Abdullah , Vlastos Dimitrios , Raubenheimer Hilgardt , Devbhandari Mohan , Patel Anant , Lim Eric
Published: June 2022

OBJECTIVES

We sought to evaluate the impact of different national clinical guidelines (with consistent and conflicting recommendations) on clinician’s practice in the UK.

METHODS

In this cohort study, we analysed data from National Lung Cancer Audit comprising all patients diagnosed with lung cancer between 2008 and 2013 within England and Wales for consistent (British Thoracic Society and National Institute of Clinical Excellence) recommendations for lower/more permissive lung function but opposing stage (N2) selection parameters for surgery.

RESULTS

From 2008 to 2013, data from 167 192 patients with primary lung cancers were included. The proportion of patients undergoing surgery for lung cancer increased from 9.5% to 20.5% in 2013 (P < 0.001) as the number of general thoracic surgeons in the UK increased from 40 to 81 in the corresponding timeframe. Mean forced expiratory volume in 1 s of surgical patients increased from 76% (22) to 81% (22) in 2013 (P < 0.001). Of the patients undergoing surgery, the proportion of patients with N2 disease across the 6-year interval was broadly consistent between 8% and 11% without any evidence of trend (P = 0.125).

CONCLUSIONS

Within 3 years of new clinical guideline recommendations, we did not observe any overall change suggesting greater selection for surgery on lower levels of lung function. When presented with conflicting recommendation, no observable change in selection was noted on surgery for N2 disease. The observed increase in surgical resection rates is more likely due to greater access to surgery (by increasing number of surgeons) rather than any impact of guideline recommendations.