Article
Physics, Applied
Yueming Sun, Jianzhao Geng, Rodney A. Badcock, Zhenan Jiang
Summary: The dynamic resistance and voltage of REBCO coated conductors (CCs) under combined AC and DC magnetic fields were studied. The dynamic resistance showed linearity with the applied AC magnetic field and became less dependent on the AC field frequency with increasing DC magnetic field. The dynamic voltage exhibited the same fundamental frequency as the applied AC field under a DC magnetic field, contrasting with the doubling of the frequency observed under pure AC fields.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Justin M. Brooks, Mark D. Ainslie, Rodney A. Badcock, Chris W. Bumby
Summary: This study discusses the phenomenon of dynamic resistance in superconducting cables, specifically focusing on the threshold field for dynamic resistance in cables comprised of N tapes connected in parallel and stacked vertically. The finite element analysis results were compared with calculations using analytical models assuming a critical state, showing a close resemblance between the finite element data and predictions for a single tape rapidly tending towards the slab result as N increases.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
Yueming Sun, Jin Fang, Gennady Sidorov, Rodney A. Badcock, Nicholas J. Long, Zhenan Jiang
Summary: The study measured the dynamic resistance and total loss in a three-tape HTS coated conductor stack under different magnetic field and current conditions, showing that the dynamic loss in the stack is smaller compared to the single tape and is affected by shielding effects.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Instruments & Instrumentation
Kuifeng Wang, Zhi Xu, Xuan Li, Wuxiang Sun, Zhixin Yang, Hu Huang
Summary: This study investigated the impact of changing the angle between the piezoelectric stack and the mover on the performance of piezoelectric actuators. The results showed that the best output performance was obtained at a 0-degree angle.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Applied
Y. Takeda, G. Nishijima, U. Nakai, T. Motoki, J. Shimoyama, H. Kitaguchi
Summary: This study systematically evaluates the angular dependence of resistance and critical current of a Bi-2223 superconducting joint in a closed-loop sample using a joint resistance evaluation system. The results show that the resistance and critical current of the joint depend on the angle of the magnetic field, and exhibit different characteristics in different angle ranges.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Jintao Hu, Jun Ma, Jiabin Yang, Mengyuan Tian, Adil Shah, Ismail Patel, Haigening Wei, Luning Hao, Yavuz Ozturk, Boyang Shen, Tim A. Coombs
Summary: This paper reports a numerical study of a new HTS switch design made of series-connected YBCO stacks. The study aims to understand the characteristics of dynamic resistance and power loss, and their relationships with the amplitude and frequency of the AC magnetic field. The energy conversion efficiency of the HTS switch is also investigated.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Multidisciplinary Sciences
Ali J. Mazaltarim, John J. Bowen, Jay M. Taylor, Stephen A. Morin
Summary: Materials and strategies for dynamic transport of microdroplets are relevant to various applications such as surface fluidics and analytical devices. Advanced techniques based on electrowetting, micropatterns, and gradients have been developed, but challenges remain in dynamic microdroplet transport. This study highlights the fabrication of mechano-tunable microtextured chemical gradients on elastomer films for controlled microdroplet transport. The interplay between driving forces and microtopography enables accurate prediction of conditions for successful transport.
NATURE COMMUNICATIONS
(2021)
Article
Plant Sciences
Renjian Liu, Bingbing Shu, Yuyuan Wang, Bingwei Yu, Yixi Wang, Yuwei Gan, Yonggui Liang, Zhengkun Qiu, Jianguo Yang, Shuangshuang Yan, Bihao Cao
Summary: This study analyzed the effects of high-temperature stress (HTS) on eggplant seedlings, flower organs, and fruits, and identified a thermotolerant eggplant line (E390) and a thermosensitive eggplant line (HM). Physiological indices, chlorophyll fluorescence, and photosynthetic system parameters were analyzed to compare the two lines under HTS. Transcriptome analysis identified 23 candidate genes responding to HTS, and their expression patterns were verified using quantitative real-time RT-PCR. The study suggests that HSP70, MYB44, AFP2, HSFA8, EGY3, HSFA3, and TIFY6B may enhance the heat resistance of eggplant.
ENVIRONMENTAL AND EXPERIMENTAL BOTANY
(2023)
Article
Physics, Applied
Zhuoyan Zhong, Wei Wu, Li Lu, Boyang Shen, Fangliang Dong, Longbiao Wang, Zhiyong Hong, Zhijian Jin
Summary: High-temperature superconducting (HTS) coils used as DC magnets can be operated under significant AC fields, which affects the redistribution of current and the stable magnetic field and voltage of the coil. Experimental results show that the contact resistivity distribution and exposure to AC fields influence the time evolution of the central magnetic field and voltage. The stable field reduction and DC voltage are determined by the local contact resistivity of specific turns and the non-insulated turn-to-turn contact reduces loss induced by dynamic resistance.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Chao Li, Yuying Xing, Beitao Zhao, Hongye Zhang, Ning Li, Ying Xin, Bin Li
Summary: This paper presents a numerical model to study the dynamic resistance of series-connected high temperature superconductor (HTS) stacks. Experimental results show that the proposed model can accurately describe dynamic resistance and investigate how insulation thickness and AC magnetic field frequency impact the dynamic resistance.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Optics
Kanak Datta, Zhengyang Lyu, Zidong Li, Takashi Taniguchi, Kenji Watanabe, Parag B. Deotare
Summary: This study utilizes two-dimensional transition metal dichalcogenides as a platform to investigate the effect of strain on exciton transport at room temperature. By using Rayleigh-type surface acoustic waves, controlled and directional exciton transport under weak coupling regime has been successfully demonstrated. The findings provide important insights into the weak coupling regime between dynamic strain wave and room-temperature excitons, and pave the way for exciting applications of excitonic devices.
Article
Electrochemistry
Wesley Chang, Tongwei Xu, Daniel Steingart
Summary: This study provides quantifiable evidence for the behavior of lithium metal batteries under operating temperature and stack pressure, and explores the possible effects of temperature and pressure on the cell dynamics and chemistry. This will aid in the development of improved lithium metal batteries.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Computer Science, Information Systems
Hyeonji Ha, Daeun Shim, Hyeyin Lee, Dongchul Park
Summary: The research proposes a dynamic hot data identification scheme utilizing workload stack distance approximation, which achieves excellent accuracy and improves performance significantly while reducing computational and space requirements. By judiciously balancing recency and frequency based on workload characteristics, the dynamic scheme outperforms existing approaches.
Article
Thermodynamics
Yao Zhai, Guangtong Ma, Jing Li, Pengbo Zhou, Gang Ren, Yanyu Zhou
Summary: The numerical characterization for the dynamic behavior of DC-carrying HTS coils subjected to alternating magnetic fields is important for design and protection. This paper presents an equivalent modeling approach to study the dynamic behavior. The study shows that the current sharing effect mainly occurs at the outer layers of the coil and gradually spreads to the inner layers with the increase of external field amplitude.
Article
Physics, Applied
Zhuoyan Zhong, Wei Wu, Zhijian Jin
Summary: This study systematically investigates an unexpected dynamic resistance phenomenon in the first cycle of AC fields, which can lead to demagnetization in closed-loop HTS coils and needs to be taken into consideration in the design of HTS applications.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Applied
Xin Zhao, Jin Fang, Zhenan Jiang, Wenjuan Song, Nengwen Liu, Yuan Gao, Xiaohang Li, Fanhui Zeng, Yajun Xia, Rod A. Badcock, Nicholas J. Long, Mike P. Staines, Robert G. Buckley, Xinyu Fang, Yulong Li, Bo Liu, Jinyin Zhang, Wen Han, Li Li, Jin Wang, Peiqing Gao
Summary: This article reports the development progress of a 6.6 MVA high-temperature superconducting traction transformer (HTSTT), which is smaller and lighter than conventional transformers. With the introduction of flux diverters and an optimized winding design, the HTSTT achieved high short-circuit impedance and low AC loss. The insulation structure passed the insulation tests specified in the Chinese standard GB/T 25120-2010. An open cooling system with reduced pressure was developed, resulting in an efficiency above 99% for the HTSTT.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Bartholomew M. M. Ludbrook, Shahna M. M. Haneef, Xiyong Huang, Jofferson Gonzales, Dominic Moseley, Mike Davies, Owen Duke, Erica E. E. Salazar, Rodney A. A. Badcock
Summary: Quasi-continuous arrays of fiber Bragg gratings (FBGs) have great potential for quench protection in superconductors. The number of identical gratings and their reflectivity are important factors determining the sensitivity of the system to local temperature or strain perturbations. By applying strain to a single FBG and mapping the detection sensitivity for a given position relative to the peak reflectance of the FBG array, we demonstrate that the position of the perturbed FBG only matters due to the broadband attenuation of the probe light down the array. Varying the number of gratings in the array allows us to understand the relationship between gratings, reflectivity, and system sensitivity. We highlight the critical role of modeling the spectrum of the FBG array in predicting system performance.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Yue Wu, Jin Fang, Naoyuki Amemiya, Rodney A. Badcock, Nicholas J. Long, Zhenan Jiang
Summary: The presence of iron cores in high temperature superconducting (HTS) coil windings significantly increases AC loss, but this can be reduced by increasing the distance between the iron cores and coil windings.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Jordan Clarke, Bradley Leuw, Sriharsha Venuturumilli, Ben Mallett, Dominic A. Moseley, Chris Bumby, Rodney A. Badcock
Summary: Transformer-rectifier flux pumps offer an elegant solution for generating high currents in superconducting magnets. By utilizing step-down transformers and superconducting switches, these pumps minimize heat-load during magnet charging. Recent studies have shown the feasibility of J(c)(B) switching, a method that reduces critical current through applied DC magnetic fields. This study presents the first conduction-cooled transformer-rectifier driven by J(c)(B) switching, successfully charging a magnet up to its critical current while monitoring component temperatures and exploring the effects of applied current and switch temperature on charging time and maximum current.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Honghai Song, Zhenan Jiang, Wenjuan Song
Summary: This paper focuses on the AC loss issue of high temperature superconductor coils at 20-40 K. It is found that at 20 K or 40 K, the magnet generates 200-400 W AC loss at 5 Hz, which can be cooled by two single stage cryocoolers. The magnet based on 6/2 Roebel cable may allow higher frequency (6-8 Hz) due to its transposition and narrower conductor width.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Grant Lumsden, Sarat Singamneni, Bart Ludbrook, Huub Weijers, Rodney A. Badcock
Summary: The Robinson Research Institute at Victoria University Wellington is constructing superconducting motors to showcase technology pathways for the transport industry, specifically aviation. These motors feature rotor-mounted superconducting field coils and a superconducting stator in an air-core configuration. The study explores the use of additively manufactured polymers with various filler materials as structural support for motor coils, and initial testing has been conducted to assess their performance.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Ben George Koshy, Yueming Sun, Rodney A. Badcock, Benjamin P. P. Mallett, Zhenan Jiang
Summary: In this study, the dynamic resistance and total loss of a 4-mm wide Superpower REBCO coated conductor (CC) under varying perpendicular magnetic fields and temperatures are investigated. The results show that the previously developed equations can be used to predict the dynamic resistance, and finite dynamic loss is observed below the threshold magnetic field due to the emergence of resistance. The total loss decreases with increasing temperature, except for a lift-off observed at around 1 T magnetic field.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Jakub Glowacki, Cameron A. Shellard, Zhenan Jiang
Summary: Magnetohydrodynamic control of diffusive flames can alter combustion in hybrid rocket engines. However, substantial magnetic fields are needed, which cannot be generated by copper electromagnets. This study presents a feasibility analysis of using an HTS magnet for lab-scale technology demonstration.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Swarn S. Kalsi, James G. Storey, Justin M. Brooks, Grant Lumsden, Rodney A. Badcock
Summary: A 100 kW, 4500 RPM synchronous superconducting motor is being developed at the Paihau-Robinson Research Institute. It features superconducting excitation field coils, contactless superconducting dynamo exciter, EM shield, and a unique single-layer winding design. The motor aims to evaluate different technologies and achieve a 3.0 MW machine with superconducting armature and field windings, offering smaller size, lower mass, and higher efficiency compared to permanent magnet motors in the same power range.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Physics, Applied
J. J. Schuyt, O. Duke, D. A. Moseley, B. M. Ludbrook, E. E. Salazar, R. A. Badcock
Summary: This study investigates the effects of gamma irradiation on radiation-induced attenuation (RIA) in photosensitive and radiation-hard fibers at cryogenic temperatures, under different photobleaching conditions. The results show that increasing probe power and using lower wavelength light significantly reduces RIA in both fiber types, with radiation-hard fibers being more resistant. Deconvolution of RIA growth curves reveals that it consists of transient and long-term components related to specific radiation-induced defects in each fiber composition. Ultimately, this study demonstrates effective management of cryogenic RIA in fiber optic sensing systems using radiation-hard fibers and dual-wavelength photobleaching strategies.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Computer Science, Information Systems
Yue Wu, Jin Fang, Naoyuki Amemiya, Rodney A. Badcock, Nicholas J. Long, Zhenan Jiang
Summary: Iron cores are used to enhance the magnetic field in high temperature superconducting power devices, but they increase AC loss in coil windings. To reduce this loss, flux diverters can be applied near the coil windings. Simulation results show that using flux diverters can effectively reduce AC loss in coil assemblies.
Article
Computer Science, Information Systems
Yuan Wang, Jin Fang, Yusuke Sogabe, Rodney A. Badcock, James G. Storey, Zhenan Jiang
Summary: This study numerically investigates the total AC loss and magnetization loss of REBCO tapes under rotating magnetic fields and perpendicular AC standing wave magnetic fields. The results show that the magnetization loss is substantially higher in the perpendicular standing wave compared to the rotating magnetic fields under certain conditions. The study highlights the importance of considering the effects of non-uniform field distribution.
Article
Computer Science, Information Systems
Wenjuan Song, Rodney A. Badcock, Nicholas J. Long, Zhenan Jiang
Summary: To construct large-scale superconducting devices, it is critical to enhance the current carrying capability of superconducting coils. The research found that the AC loss in straight 8/2 TPS and 4/4 ES cables is larger than that in 8/2 Roebel cables. The current in the outer strands of straight 8/2 TPS and 4/4 ES cables is more concentrated, resulting in greater AC loss compared to 8/2 Roebel cables.
