Cryogenics最新文献

{"title":"Magnetic properties of Ni-Cu-Zn ferrite nanoparticles at cryogenic temperature probed under Mössbauer and VSM studies","authors":"K.S. Ramakrishna ,&nbsp;Ch. Srinivas ,&nbsp;E. Ranjith Kumar ,&nbsp;T. Pushpagiri ,&nbsp;Sher Singh Meena ,&nbsp;Pramod Bhatt ,&nbsp;D.L. Sastry","doi":"10.1016/j.cryogenics.2025.104040","DOIUrl":"10.1016/j.cryogenics.2025.104040","url":null,"abstract":"<div><div>This article presents a comprehensive analysis of magnetic properties of Ni<em>_x</em>Cu_0.1Zn_0.9−<em>_x</em>Fe₂O₄ (<em>x</em> = 0.5, 0.6, 0.7). Typical variation of bond angles supported the <em>A</em>-<em>B</em> superexchange interaction. The unsaturated magnetization even at higher applied field shows the core–shell interactions of present ferrite nanoparticles. Neel’s sublattice and core–shell models have been adopted to analyze the magnetic behaviour. The saturation magnetization is unevenly varying in both sintered ferrite samples. It was found to be in the range of 15.29–28.04 emu/g. The highest of saturation magnetization (28.04 emu/g) was reported for the ferrite composition Ni_0.7Cu_0.1Zn_0.4Fe₂O₄ sintered at 500 °C. The coercivity seems to be dependent on magnetic anisotropy. The cusp between the field cooled and zero field cooled curves revealed the large distribution of ferrite nanoparticles in different sizes. The blocking temperature increases in both sintered ferrite samples with the substitution of Ni²⁺. The blocking temperature depends on the variation of crystallite size. The appearance of quadruple and hyperfine spectral lines in Mössbauer spectra represent the distribution of ferrite nanoparticles in different sizes. The range of isomer shift (0.194 – 0.463 mm/s) is less than 0.5 mm/s that represents the presence of only high spin Fe³⁺ ions.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104040"},"PeriodicalIF":1.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and simulation study of LN2 active-pressurization in onboard LH2 storage and supply systems","authors":"Hao Qiu,&nbsp;Bifeng Yin,&nbsp;Fei Dong,&nbsp;Xuan Xie,&nbsp;Sheng Xu","doi":"10.1016/j.cryogenics.2025.104042","DOIUrl":"10.1016/j.cryogenics.2025.104042","url":null,"abstract":"<div><div>To prevent insufficient pressure within the onboard LH₂ storage tank during supply, which could lead to significant residual LH₂ that cannot be supplied, the design of the onboard LH₂ storage and supply system needs to consider the active-pressurization method of the LH₂ tank. To investigate whether the active-pressurization method can meet the active-pressurization performance requirements for low-temperature fluids in onboard LH₂ storage tanks, this study uses LN₂ as the working fluid. Experiments on active-pressurization and supply in the onboard LH₂ storage system were conducted, exploring the impact of different LN₂ fill levels on the active-pressurization rate and the pressure stability during the active-pressurization supply process. Based on the parameters of the LH₂ tank, a system simulation model was established. The maximum active-pressurization flow rate of the simulation model was calibrated according to the active-pressurization experimental data, further exploring the active-pressurization storage and supply characteristics of the onboard LH₂ tank. The results indicate that the active-pressurization supply simulation results, calibrated with the active-pressurization flow rate, show good consistency with the experimental data. As the supply flow rate increases, the active-pressurization maintaining pressure slightly decreases. When the liquid level drops too low and transitions to gaseous supply, the pressure inside the tank rapidly declines. At an ambient temperature of −10 °C, the active-pressurization can still offset the pressure drop caused by the supply. However, higher ambient temperatures increase the temperature difference during, leading to a higher evaporation rate inside the tank. The active-pressurization flow rate was corrected by the ratio of the densities and viscosities of LN₂ and LH₂ to investigate the situation of active-pressurization to exceed the critical pressure. When the LH₂ tank is actively pressurized to the critical pressure, there is still a return gas temperature difference close to 170 K, which is much higher than the 0 K of LN₂, thereby promoting the active-pressurization rate. This study explored the active-pressurization capability and influencing factors of onboard LH₂ storage tanks through LN₂ experiments and system simulation methods, providing a foundation for precise control of the active-pressurization supply in onboard LH₂ systems.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104042"},"PeriodicalIF":1.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on catalytic conversion and flow characteristics of ortho-para hydrogen in tubular packed-bed converters at liquid nitrogen temperature","authors":"Kai Wang ,&nbsp;Sheng Xu ,&nbsp;Jinming Zheng ,&nbsp;Shaolong Zhu ,&nbsp;Song Fang ,&nbsp;Hongmei Xiao ,&nbsp;Na Li ,&nbsp;Limin Qiu","doi":"10.1016/j.cryogenics.2025.104041","DOIUrl":"10.1016/j.cryogenics.2025.104041","url":null,"abstract":"<div><div>Ortho-para hydrogen conversion is a critical process in hydrogen liquefaction. However, comprehensive data and correlations on the ortho-para hydrogen conversion and pressure drop within catalyst packed beds across the typical range of Reynolds numbers encountered in converters/heat exchangers are still lacking. This study established an experimental setup to measure the catalytic conversion of ortho-para hydrogen and the associated pressure drop in tubular packed-bed converters in the liquid nitrogen temperature range. The effects of the particle size of iron oxide catalysts (20–80 mesh), space velocity (1.5–22 kg/(m³·s)), and packed-bed porosity (0.27–0.46) on the catalytic conversion of ortho-para hydrogen, along with the pressure drop characteristics, were examined at around 77 K and 2 MPa. A correlation was further developed for estimating the outlet concentration of para hydrogen with given space velocity, which would be useful for determining the catalyst dosage based on the targeted conversation rate in the product. Furthermore, by modifying the coefficients for viscous and inertial resistance on the basis of the Ergun equation, pressure drop correlations for packed-bed catalytic converters with different particle sizes were proposed, with remarkably improved predictive accuracy. This work offers critical prediction correlations for the design of ortho-para hydrogen catalytic converters/heat exchangers.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104041"},"PeriodicalIF":1.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of the thermal expansion of bulk metallic glass in cryogenic temperature with a laser displacement method","authors":"Takashi Hirayama,&nbsp;Sojiro Uemura,&nbsp;Takaaki Morie","doi":"10.1016/j.cryogenics.2025.104037","DOIUrl":"10.1016/j.cryogenics.2025.104037","url":null,"abstract":"<div><div>The thermal expansion of structural components is a very important factor when designing cryogenic equipment such as cryocooler or superconducting equipment. However, conventional thermal expansion measurement systems require calibration of the sensor of the measurement system at cryogenic temperature, making measurement difficult. Therefore, in this study, we developed a new thermal expansion measurement system that can measure thermal expansion more conveniently than conventional measurement systems. Thermal expansion was measured using laser displacement units installed outside the vacuum vessel. Moreover, a conduction cooling system using a 4K-GM cryocooler was adopted for cooling. To confirm the effectiveness of the developed system, the thermal expansion of copper, a well-known material, was measured using this system, and the results were consistent with that of a previous study. The thermal expansion of bulk metallic glass, which is expected to be used in cryogenic environments, was measured using the developed system, and it was found to be -0.23% at cryogenic temperatures, smaller than that of other typical materials such as copper and aluminum.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104037"},"PeriodicalIF":1.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experiments and simulations related to the sudden application of a heat pulse onto a supercritical helium flow","authors":"S. Shoala ,&nbsp;E. Ercolani ,&nbsp;F. Ayela ,&nbsp;J.M. Poncet","doi":"10.1016/j.cryogenics.2025.104029","DOIUrl":"10.1016/j.cryogenics.2025.104029","url":null,"abstract":"<div><div>Vacuum loss is a major accidental scenario in cryogenic facilities that use vacuum for thermal insulation from the surrounding environment. An experimental facility, called HELIOS, has been set up to study vacuum loss around a cryoline in which supercritical helium is flowing. Before carrying out real vacuum loss experiments, a preliminary test campaign was performed using an electrical test section inserted into a cryogenic loop within the HELIOS facility, at the exact location of the future vacuum loss test section. The electrical section is equipped with an electrical heater that was used to simulate the heat pulse that would be experienced by the supercritical helium flow in the event of a real vacuum loss accident. The consequences of the abruptly applied heat pulse have been studied, both in real and simulated conditions. The main objectives of this first experimental campaign are multiple: to assess the design of the HELIOS facility, verify the accuracy of the heat flux measurement methods, and use the results of the experimental test campaigns to improve the qualification of the thermal hydraulic code employed to size the experimental setup. The simulation was based on the thermal–hydraulic code CATHARE 3 and includes two-phases cryogenic flows. Thermal-hydraulic parameters of the supercritical helium flow as pressure, temperature and mass flow rate, have been recorded for several heat loads running from 0.45 kW to 2.5 kW, with durations of up to 2 min. Heat transfer in the supercritical loop and the liquid helium bath, as well as corresponding energy balances, have been calculated. The resulting estimations of the heat applied to the test section correspond with an excellent accuracy to the real thermal loads. For a heat flux of 1.35 kW, the data were also simulated with the CATHARE 3 code. The results of the simulation match the measured and calculated data with high accuracy. This preliminary work and its associated conclusions provide a firm basis for forthcoming experiments, which will be devoted to the study of heat transfer following a real breakdown of the insulating vacuum in the supercritical helium loop.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104029"},"PeriodicalIF":1.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-pressure growth effect on the properties of high-Tc iron-based superconductors: A short review","authors":"Priya Singh,&nbsp;Manasa Manasa,&nbsp;Mohammad Azam,&nbsp;Shiv J. Singh","doi":"10.1016/j.cryogenics.2025.104028","DOIUrl":"10.1016/j.cryogenics.2025.104028","url":null,"abstract":"<div><div>The high-pressure growth technique is a vital approach that facilitates the stabilization of new phases and allows for meticulous control of structural parameters, which significantly impact electronic and magnetic properties. We present a short review of our ongoing investigations into various families of iron-based superconductors (IBS), employing the high-gas pressure and high-temperature synthesis (HP-HTS) method. This technique is capable of producing the gas pressures up to 1.8 GPa and a heating temperature of up to 1700 °C through a three-zone furnace within a cylindrical chamber. Different kinds of IBS samples are prepared using HP-HTS and characterized through various measurements to reach the final conclusions. The results demonstrate that the high-pressure growth technique significantly enhances the properties of IBS, including the transition temperature, critical current density, and pinning force. In addition, the quality of the samples and their density are improved through the intergrain connections. Furthermore, the comprehensive evaluations and investigations prove that a growth pressure of 0.5 GPa is sufficient for producing high-quality IBS bulks under the optimized synthesis conditions.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104028"},"PeriodicalIF":1.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143198157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of two-phase heat transfer coefficients of cryogenic nitrogen in 160-μm and 65-μm microchannels","authors":"Seungwhan Baek ,&nbsp;Ray Radebaugh ,&nbsp;Peter E Bradley","doi":"10.1016/j.cryogenics.2025.104026","DOIUrl":"10.1016/j.cryogenics.2025.104026","url":null,"abstract":"<div><div>In this study, the two-phase microheat transfer characteristics of cryogenic two-phase nitrogen were investigated. This basic information is required for the sequential design of mixed-refrigerant microcryocoolers. The effective heat exchanger must be designed with a hydraulic diameter (<em>D_h</em>) of less than 100 µm. The experimental setup was developed using microchannels with <em>D_h</em> values of 160 µm and 65 µm. The two-phase heat transfer coefficient was evaluated under different qualities (<em>x</em>), mass fluxes (<em>G</em> = 50–150 kg/m²s), and heat fluxes (<em>q’’=</em>5–15 kW/m²). The two-phase heat transfer coefficient values ranged from 5000 to 20000 W/m²K. The measured heat transfer coefficient values were compared with the predicted values from existing heat transfer correlations derived by Liu and Winterton. The mean percentage error (MPE) was as low as 25.6 %. Moreover, the correlation derived by Karayiannis and Mahmoud, which was derived for ambient-temperature applications, was found suitable for predicting previous cryogenic microchannel literature data (<em>D_h</em>: 300–10000 µm). When applying these findings to mixed refrigerants in microchannels, it is crucial to account for the reduced influence of mass flux on nucleate boiling and the dominance of thin-film evaporation under varying heat flux conditions in confined microscale geometries.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"147 ","pages":"Article 104026"},"PeriodicalIF":1.8,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143198158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nusselt number correction for stacked wire mesh considering finite heat capacity below 50 K","authors":"Zhengkun Li ,&nbsp;Xupeng Ding ,&nbsp;Yanyan Chen ,&nbsp;Xiaotao Wang ,&nbsp;Wei Dai","doi":"10.1016/j.cryogenics.2025.104025","DOIUrl":"10.1016/j.cryogenics.2025.104025","url":null,"abstract":"<div><div>In regenerative cooling systems, the heat transfer characteristics of regenerators employing stacked wire mesh are critically important. Numerous experimental and numerical investigations have been conducted to characterize the Nusselt number of regenerators, focusing on room temperature conditions where the solid heat capacity is sufficiently large compared to that of the gas . In this study, the #400 stainless steel mesh is simulated in three dimensions at pore scale to investigate the Nusselt number across various flow conditions, considering both unidirectional and oscillating flow. Under unidirectional flow, the heat transfer characteristics below 77 K are studied. Considering the influence of finite heat capacity of stainless steel, a modified Nusselt number formula applicable to the 50 K to 20 K range is generalized. Subsequently, the heat transfer characteristics under oscillating flow, including different frequencies and pressure ratios, are investigated. The results provide further evidence supporting the similarity of Nusselt numbers between oscillating and unidirectional flow. This study provides a deeper insight into the heat transfer characteristics of wire mesh regenerators at low temperatures. Meanwhile, the forementioned modified coefficient can be used for better regenerator simulations.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"146 ","pages":"Article 104025"},"PeriodicalIF":1.8,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of fibre reinforcement on cryogenic performance of novel epoxy composites for cryogenic applications","authors":"A. Krzak ,&nbsp;A.J. Nowak ,&nbsp;J. Frolec ,&nbsp;T. Králík ,&nbsp;D. Boroński ,&nbsp;M. Kotyk","doi":"10.1016/j.cryogenics.2024.103995","DOIUrl":"10.1016/j.cryogenics.2024.103995","url":null,"abstract":"<div><div>Due to the dynamic development of technology and science, there is an increasing demand for materials combining high mechanical resistance to extreme temperature conditions and suitable thermal properties. Especially the knowledge of heat transfers by conduction and thermal radiation is crucial for the successful design of devices operating at cryogenic temperatures, such as Dewars, cryostats, or space probes. This study aimed to assess important thermal and mechanical properties at cryogenic temperatures for three composite materials made of identical epoxy resin reinforced by carbon, basalt or glass fibres. Apart from loading/unloading cyclic tensile tests conducted at room temperature and in cryogenic environments at 77 K, thermal conductivity and total hemispherical emissivity were obtained in wide temperature ranges from 5 K up to 300 K. The results highlighted the importance of the fibre material and have potential to help with optimal material selection. We found that the initial stiffness of the laminates increased at low temperatures, and the glass composite exhibited the best mechanical properties. On the other hand, the carbon composite showed the lowest but steeply increasing thermal conductivity with increasing temperature. This, together with the lowest emissivity, makes the carbon composite a more favourable option for the lowest temperatures.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"145 ","pages":"Article 103995"},"PeriodicalIF":1.8,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of cryogenic treatment on the mechanical properties of 3D-printed polylactic acid part","authors":"Ayushi Gupta ,&nbsp;Narendra Kumar ,&nbsp;Anish Sachdeva ,&nbsp;Gourav Kumar Sharma ,&nbsp;Manas Kumar ,&nbsp;Ravi Verma","doi":"10.1016/j.cryogenics.2024.104000","DOIUrl":"10.1016/j.cryogenics.2024.104000","url":null,"abstract":"<div><div>The article investigates the effect of cryogenic treatment on the 3-D printed Polylactic Acid (PLA) specimen. It was found that exposure of PLA specimens to the cryogenic temperature (10 K) using a cryocooler led to a 35 % increase in tensile strength in 5 h, with most improvement occurring within the first hour. The cryogenic treatment enhanced the PLA specimen’s strength and ductility due to increased crystallinity and better molecular alignment. It is likely due to the interaction of the cooling medium (helium) used in the cryocooler with the PLA specimens. Towards this, EDS analysis is performed on cryo-treated PLA specimens. The EDS analysis reveals that nickel and iron compounds were detected on the surface of the cryogenic-treated PLA specimen. These findings highlight that cryogenic treatment significantly improves PLA specimen’s mechanical properties and tensile strength. However, challenges arise, including delamination-layer separation caused by internal stresses, and must be addressed. This work will be helpful for researchers working in polymer 3-D printing.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"145 ","pages":"Article 104000"},"PeriodicalIF":1.8,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}