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Integration Of A Prototype Wireless Communication System With Micro-Electromechanical Temperature And Humidity Sensor For Concrete Pavement Health Monitoring, Shuo Yang, Keyan Shen, Halil Ceylan, Sunghwan Kim, Daji Qiao, Kasthurirangan Gopalakrishnan Jun 2017

Integration Of A Prototype Wireless Communication System With Micro-Electromechanical Temperature And Humidity Sensor For Concrete Pavement Health Monitoring, Shuo Yang, Keyan Shen, Halil Ceylan, Sunghwan Kim, Daji Qiao, Kasthurirangan Gopalakrishnan

Daji Qiao

In recent years, structural health monitoring and management (SHMM) has become a popular approach and is considered essential for achieving well-performing, long-lasting, sustainable transportation infrastructure systems. Key requirements in ideal SHMM of road infrastructure include long-term, continuous, and real-time monitoring of pavement response and performance under various pavement geometry-materials-loading configurations and environmental conditions. With advancements in wireless technologies, integration of wireless communications into sensing device is considered an alternate and superior solution to existing time- and labor-intensive wired sensing systems in meeting the requirements of an ideal SHMM. This study explored the development and integration of a wireless communications sub-system …


Experimental Investigation Of The Velocity Field In Buoyant Diffusion Flames Using Piv And Tpiv Algorithm, Lulu Sun, Xiangyang Zhou, Shankar Mahalingam, David R. Weise Nov 2016

Experimental Investigation Of The Velocity Field In Buoyant Diffusion Flames Using Piv And Tpiv Algorithm, Lulu Sun, Xiangyang Zhou, Shankar Mahalingam, David R. Weise

Lulu Sun

We investigated a simultaneous temporally and spatially resolved 2-D velocity field above a burning circular pan of alcohol using particle image velocimetry (PIV). The results obtained from PIV were used to assess a thermal particle image velocimetry (TPIV) algorithm previously developed to approximate the velocity field using the temperature field, simultaneously captured by an infrared (IR) thermal camera. By tracing “thermal particles,” which were assumed to be virtual particles that corresponded to pixels of temperature values in successive IR images, the TPIV algorithm estimated a larger scale instantaneous velocity field than either a single-point velocity measurement (e.g., LDV) or the …


Mechanical Properties Of Intermetallic Compounds In Electrodeposited Multilayered Thin Film At Small Scale By Nanoindentation May 2015

Mechanical Properties Of Intermetallic Compounds In Electrodeposited Multilayered Thin Film At Small Scale By Nanoindentation

Faculty of Engineering University of Malaya

Mechanical properties of intermetallic compounds (IMCs) which were formed in electrodeposited Cu/Sn and Cu/Ni/Sn multilayered thin film have been investigated. The layers of Cu, Sn and Ni were formed by electrodeposition technique using copper pyrophosphate, tin methanesulfonic and nickel Watts baths, respectively. After synthesis, samples were subjected to high temperature aging at 150 degrees C for 168 h. Two different types of intermetallics Cu3Sn and Cu6Sn5 were formed in Cu/Sn. After adding ultra-thin layer of Ni (70 nm) in between Cu and Sn layers, (Cu, Ni)(6)Sn-5 was formed after aging at similar condition to that of Cu/Sn. Tin whisker growth …


The Tribological And Electrochemical Behavior Of Hvof-Sprayed Cr3c2-Nicr Ceramic Coating On Carbon Steel May 2015

The Tribological And Electrochemical Behavior Of Hvof-Sprayed Cr3c2-Nicr Ceramic Coating On Carbon Steel

Faculty of Engineering University of Malaya

High Velocity Oxygen Fuel (HVOF) is an excellent approach to prepare a good, wear-resistant lamella of Chromium Carbide-Nickel Chrome (Cr3C2-NiCr) on carbon steel for high temperature application. This research investigates the effect of a thin, deposited layer of Cr3C2-NiCr on carbon steel in terms of wear and corrosion properties. The microstructure of the HVOF-sprayed Cr3C2-NiCr coating was characterized at each step by scanning electron microscopy. Wear testing was performed with a pin-on-disk tester. Wear weight loss was examined by applying different loads over a 9048.96 m sliding distance. Experimental results show that the wear resistance of the coated sample reduced …


Changes In Heavy Rainstorm Characteristics With Time And Temperature, Barry A. Palynchuk Phd, Yiping Guo Phd Apr 2015

Changes In Heavy Rainstorm Characteristics With Time And Temperature, Barry A. Palynchuk Phd, Yiping Guo Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research is provided.


Changes In Heavy Rainstorm Characteristics With Time And Temperature - Presentation, Barry A. Palynchuk Phd Apr 2015

Changes In Heavy Rainstorm Characteristics With Time And Temperature - Presentation, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research provided.


Performance Enhancement Of A Flat Plate Solar Collector Using Titanium Dioxide Nanofluid And Polyethylene Glycol Dispersant Mar 2015

Performance Enhancement Of A Flat Plate Solar Collector Using Titanium Dioxide Nanofluid And Polyethylene Glycol Dispersant

Faculty of Engineering University of Malaya

The use of TiO2 water nanofluid as a working fluid for enhancing the performance of a flat plate solar collector has been studied. The volume fraction of the nanoparticles was 0.1% and 0.3% respectively, while the mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min, respectively. Thermo-physical properties and reduced sedimentation for TiO2-nanofluid was obtained using PEG 400 dispersant. The results reveal the impact and importance of each of these parameters. Energy efficiency increased by 76.6% for 0.1% volume fraction and 0.5 kg/min flow rate, whereas the highest exergy efficiency achieved was 16.9% for 0.1% volume fraction …


Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone Mar 2015

Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone

Faculty of Engineering University of Malaya

The aim of this research is to study the properties of natural porous hydroxyapatite developed from bovine bone through a sintering process. Bovine bone samples were prepared and sintered in an air atmosphere at different temperatures ranging from 600 degrees C to 1000 degrees C. The sintered bodies were characterized to determine the phases present, bulk density, Ca/P ratio and Vickers hardness. In addition, the microstructural evolution of the sintered porous bodies was also examined. The results revealed that the thermal stability of the HA matrix was not disrupted and that all of the sintered bodies exhibited phase pure HA. …


Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone Mar 2015

Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone

Faculty of Engineering University of Malaya

The aim of this research is to study the properties of natural porous hydroxyapatite developed from bovine bone through a sintering process. Bovine bone samples were prepared and sintered in an air atmosphere at different temperatures ranging from 600 degrees C to 1000 degrees C. The sintered bodies were characterized to determine the phases present, bulk density, Ca/P ratio and Vickers hardness. In addition, the microstructural evolution of the sintered porous bodies was also examined. The results revealed that the thermal stability of the HA matrix was not disrupted and that all of the sintered bodies exhibited phase pure HA. …


Analysis Of Transient Natural Convection Flow Past An Accelerated Infinite Vertical Plate, Innovative Research Publications Irp India, Kaprawi S. Feb 2015

Analysis Of Transient Natural Convection Flow Past An Accelerated Infinite Vertical Plate, Innovative Research Publications Irp India, Kaprawi S.

Innovative Research Publications IRP India

This work describes a vertical hot plate moves with acceleration and with variation wall temperature. The temperatures of the plate decrease with the increase of velocity of the plate. The temperature and velocity are given by the governing equations. The dimensionless equations of the problem have been solved numerically by the finite difference method. The temperature and the velocity profiles against several parameters like Prandtl Number, Grashoft number and time are presented. The results show that the temperature and velocity profiles are significantly influenced by Prandtl and Grashoft number.


Modeling The Polyphenoloxidase Inactivation Kinetics In Pear, Apple And Strawberry Purees After High Pressure Processing Feb 2015

Modeling The Polyphenoloxidase Inactivation Kinetics In Pear, Apple And Strawberry Purees After High Pressure Processing

Faculty of Engineering University of Malaya

High Pressure Processing of Royal Gala apple, Taylor's Gold pear and Camarosa strawberry purees was carried out to inactivate polyphenoloxidase (PPO). First, 600 MPa enzyme inactivation at room temperature was investigated. After 60 min, strawberry (8% RA, residual activity) and apple (89% RA) PPOs were partially inactivated and pear PPO was not inactivated, demonstrating the high variability in the resistance of different fruits' PPOs. Then, the fruit purees were submitted to 600 MPa combined with mild heat, and the PPO inactivation kinetics was modeled. The pear PPO was found to be resistant even after 60 min 600 MPa-71 degrees C …


Co-Production Of Hydrogen And Carbon Nanofibers From Methane Decomposition Over Zeolite Y Supported Ni Catalysts Jan 2015

Co-Production Of Hydrogen And Carbon Nanofibers From Methane Decomposition Over Zeolite Y Supported Ni Catalysts

Faculty of Engineering University of Malaya

The objective of this paper is to study the influences of different operating conditions on the hydrogen formation and properties of accumulated carbon from methane decomposition using zeolite Y supported 15% and 30% Ni, respectively, at a temperature range between 500 and 650 degrees C in a pilot scale fixed bed reactor. The temperature ramp was showed a significant impact on the thermo-catalytic decomposition (TCD) of methane. An optimum temperature range of 550-600 degrees C were required to attain the maximum amount of methane conversion and revealed that at 550 and 600 degrees C, catalyst showed longer activity for the …


Separation Of The Petroleum System, Ali Ibrahim Neamah Jan 2015

Separation Of The Petroleum System, Ali Ibrahim Neamah

Ali Ibrahim Neamah

This study discusses the overall process of crude oil separation as well as the necessary equipment used in the process. Also discussed and analyzed are potential issues seen in the crude oil extraction process. Reasons why these operation problems may occur are analyzed as well as treatment options for such occurring issues are discussed for employees and students alike. This research is based off of personal involvement at the Nasiriyah Degassing Station located in Dhi Qar, Iraq.


Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang Oct 2014

Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang

Shi Xue Dou

"Topological insulators, a new class of condensed matter having bulk insulating states and gapless metallic surface states, have demonstrated fascinating quantum effects. However, the potential practical applications of the topological insulators are still under exploration worldwide. We demonstrate that nanosheets of a Bi2Te3 topological insulator several quintuple layers thick display giant and linear magnetoresistance. The giant and linear magnetoresistance achieved is as high as over 600% at room temperature, with a trend towards further increase at higher temperatures, as well as being weakly temperature-dependent and linear with the field, without any sign of saturation at measured fields up to 13 …


Enhancement Of Transition Temperature In Fexse0.5te0.5 Film Via Iron Vacancies, J C. Zhuang, Wai K. Yeoh, Xiangyuan Cui, Jung Ho Kim, Dongqi Shi, Z X. Shi, S P. Ringer, Xiaolin Wang, S X. Dou Oct 2014

Enhancement Of Transition Temperature In Fexse0.5te0.5 Film Via Iron Vacancies, J C. Zhuang, Wai K. Yeoh, Xiangyuan Cui, Jung Ho Kim, Dongqi Shi, Z X. Shi, S P. Ringer, Xiaolin Wang, S X. Dou

Shi Xue Dou

The effects of iron deficiency in Fe x Se0.5Te0.5 thin films (0.8 ≤ x ≤ 1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (TC ) up to 21 K was observed in the most Fe deficient film (x = 0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the Fe x Se0.5Te0.5 films. The enhancement of TC shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the …


Ultra-High Performance, High-Temperature Superconducting Wires Via Cost-Effective, Scalable, Co-Evaporation Process, Ho-Sup Kim, Sang-Soo Oh, Hong-Soo Ha, Dojun Youm, Seung-Hyun Moon, Jung Ho Kim, S X. Dou, Yoon-Uk Heo, Sung-Hun Wee, Amit Goyal Oct 2014

Ultra-High Performance, High-Temperature Superconducting Wires Via Cost-Effective, Scalable, Co-Evaporation Process, Ho-Sup Kim, Sang-Soo Oh, Hong-Soo Ha, Dojun Youm, Seung-Hyun Moon, Jung Ho Kim, S X. Dou, Yoon-Uk Heo, Sung-Hun Wee, Amit Goyal

Shi Xue Dou

Long-length, high-temperature superconducting (HTS) wires capable of carrying high critical current, Ic, are required for a wide range of applications. Here, we report extremely high performance HTS wires based on 5 μm thick SmBa2Cu3O7 − δ (SmBCO) single layer films on textured metallic templates. SmBCO layer wires over 20 meters long were deposited by a cost-effective, scalable co-evaporation process using a batch-type drum in a dual chamber. All deposition parameters influencing the composition, phase, and texture of the films were optimized via a unique combinatorial method that is broadly applicable for co-evaporation of other promising complex materials containing several cations. …


Rational Design Of P-Type Thermoelectric Pbte: Temperature Dependent Sodium Solubility, Sima Aminorroaya-Yamini, Teruyuki Ikeda, Aaron Lalonde, Yanzhong Pei, S X. Dou, G. Jeffrey Snyder Mar 2014

Rational Design Of P-Type Thermoelectric Pbte: Temperature Dependent Sodium Solubility, Sima Aminorroaya-Yamini, Teruyuki Ikeda, Aaron Lalonde, Yanzhong Pei, S X. Dou, G. Jeffrey Snyder

Shi Xue Dou

We develop a solid understanding of the termperature-dependent solubility of sodium p-type PbTe, the most efficient thermoelectric material. The maximum solubility of socium telluride (NaTe) in PbTe is measured to be 1.4+0.3 at percent and the heat of solution is evaluated and that addresses fundamental issues regarding the formation of nano-precipitates.


Effects Of Feed And Draw Solution Temperature And Transmembrane Temperature Difference On The Rejection Of Trace Organic Contaminants By Forward Osmosis, Ming Xie, William E. Price, Long D. Nghiem, Menachem Elimelech Oct 2013

Effects Of Feed And Draw Solution Temperature And Transmembrane Temperature Difference On The Rejection Of Trace Organic Contaminants By Forward Osmosis, Ming Xie, William E. Price, Long D. Nghiem, Menachem Elimelech

William E. Price

The effects of feed and draw solution temperature and transmembrane temperature difference on the rejection of 12 trace organic contaminants (TrOCs) by two forward osmosis (FO) membranes were investigated. The membrane structure parameter (S) and the reverse salt (NaCl) flux selectivity (RSFS) were constant over the temperature range of 20-40 1C, suggesting that within this range, the solution temperature did not significantly influence the membrane polymeric structure. Draw solution properties, including diffusivity, viscosity, and osmotic pressure, played an important role in water and reverse salt (NaCl) flux behaviour and TrOC rejection. Pure water and salt (NaCl) permeability coefficients of the …


Impact Of Chemical Cleaning On The Nanofiltration Of Pharmaceutically Active Compounds (Phacs): The Role Of Cleaning Temperature, Alexander Simon, William E. Price, Long D. Nghiem Oct 2013

Impact Of Chemical Cleaning On The Nanofiltration Of Pharmaceutically Active Compounds (Phacs): The Role Of Cleaning Temperature, Alexander Simon, William E. Price, Long D. Nghiem

William E. Price

This study investigated the impact of chemical cleaning on the physicochemical properties of a nanofiltration membrane and its subsequent separation efficiency of inorganic salts and two pharmaceutically active compounds (PhACs), sulfamethoxazole and carbamazepine. Chemical cleaning was simulated by immersing virgin membrane samples in aqueous citric acid, sodium hydroxide (NaOH), ethylenediaminetetraacetic-acid (EDTA) and sodium dodecyl sulphate (SDS) at various temperatures for 18 h. The cleaning temperature did not exert any discernible impact on the surface charge of the NF270 membrane selected in this study. However, high cleaning temperatures were shown to either amplify or reduce the impact of chemical cleaning on …


Temperature Effect On Microstructure And Electromagnetic Performance Of Polycarbosilane And Sugar-Doped Mgb2 Wires, Andrey V. Shcherbakov, Josip Horvat, Olga V. Shcherbakova, Nikolina Novosel, Emil Babic, S. X. Dou Oct 2013

Temperature Effect On Microstructure And Electromagnetic Performance Of Polycarbosilane And Sugar-Doped Mgb2 Wires, Andrey V. Shcherbakov, Josip Horvat, Olga V. Shcherbakova, Nikolina Novosel, Emil Babic, S. X. Dou

Josip Horvat

The effect of processing temperature on structural and superconducting properties of 10 wt.% sugar- and 10 wt.% PCS-doped MgB2 wires is systematically investigated. It is demonstrated that these dopants significantly enhance the electromagnetic performance of Fe-clad MgB2 superconductor and increase its potential for practical application. The enhancement of in-field critical current density (Jc(Ba)) and upper critical field (Bc2) is due to formation of a large amount of lattice defects caused by impurities and C substitution into the MgB2 crystal lattice. High temperature sintering of sugar-doped sample results in as high Bc2 value as 37 T (at 5 K), which correlates …


Cyclic Heating To Inhibit Bacterial Growth In Activated Carbon Point-Of-Use Treatment Devices, Irwin Silverstein, Irvine W. Wei Aug 2013

Cyclic Heating To Inhibit Bacterial Growth In Activated Carbon Point-Of-Use Treatment Devices, Irwin Silverstein, Irvine W. Wei

Irvine W. Wei

The effectiveness of using heat treatment on a cyclic basis as a means of inhibiting bacterial growth in activated carbon point-of-use treatment devices was examined. Heat treated and non-heat treated devices were compared in a controlled experiment with respect to parameters such as standard plate count, total organic carbon, total residual chlorine and head loss. The results of the study indicated that cyclic heat treatment can inhibit bacterial growth on the surface of granular activated carbon without compromising total organic carbon and total residual chlorine removal efficiencies or accelerating head loss. Microbiological testing verified that the control device had become …


Temperature-Dependent Electrical, Elastic And Magnetic Properties Of Solgel Synthesized Bi 0.9ln 0.1feo 3 (Ln=Nd,Sm), J Schiemer, R L Withers, M Carpenter, Y Liu, Jianli Wang, L Noren, Q Li, W Hutchison Jul 2013

Temperature-Dependent Electrical, Elastic And Magnetic Properties Of Solgel Synthesized Bi 0.9ln 0.1feo 3 (Ln=Nd,Sm), J Schiemer, R L Withers, M Carpenter, Y Liu, Jianli Wang, L Noren, Q Li, W Hutchison

Jianli Wang

This report details correlated electrical, mechanical and magnetic behaviour in BiFeO3 ceramics doped with 10% Ln (Ln D Sm, Nd) ions on the Bi, or perovskite A, site and synthesized by a sol-gel method. The ceramics exhibit bulk piezoelectric and ferroelectric properties and clear ferroelectric domain patterns through piezoresponse force microscopy. Resonant ultrasound spectroscopy, dielectric spectroscopy and magnetometry studies show correlated magnetoelectromechanical behaviour and the existence of weak ferromagnetism for both compositions. An anomaly with simultaneous mechanical and magnetic signatures is discovered in both materials near room temperature, while previously reported transitions and anomalies are found to exhibit electro- and/or …


The Effects Of Annealing Temperature On The In-Field Jc And Surface Pinning In Silicone Oil Doped Mgb2 Bulks And Wires, M S. Hossain, A Motaman, O Cicek, H Agil, E Ertekin, A Gencer, Xiaolin Wang, S X. Dou Jun 2013

The Effects Of Annealing Temperature On The In-Field Jc And Surface Pinning In Silicone Oil Doped Mgb2 Bulks And Wires, M S. Hossain, A Motaman, O Cicek, H Agil, E Ertekin, A Gencer, Xiaolin Wang, S X. Dou

Shi Xue Dou

No abstract provided.


Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou Jun 2013

Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou

Shi Xue Dou

Different types of superconductors have been investigated at small magnetic fields (Ba) over wide temperature (T) ranges at different Ba orientations. It has been shown that the temperature dependence of the characteristic field (B*), separating the Ba-independent critical current density (Jc) plateau (single vortex pinning regime) and the region with Jc(Ba) (collective pinning), can be attributed either to the temperature dependence of the magnetic penetration depth for Nb-film and MgB2bulk superconductors, or to thermally activated processes for Bi-based superconductors and YBa2Cu3O7−δ superconducting films. In both cases the vortex pinning influence appears to have a secondary role, affecting the effective vortex …


Reduction Of Superconducting Transition Temperature And Flux Pinning In Al And C Codoped Mgb2 With Insight From First-Principles Calculations, Aihua Li, Xiaolin Wang, S X. Dou, Qiwen Yao, Zhenxiang Cheng, Saeid Soltanian, J M. Yoo, P Munroe Jun 2013

Reduction Of Superconducting Transition Temperature And Flux Pinning In Al And C Codoped Mgb2 With Insight From First-Principles Calculations, Aihua Li, Xiaolin Wang, S X. Dou, Qiwen Yao, Zhenxiang Cheng, Saeid Soltanian, J M. Yoo, P Munroe

Shi Xue Dou

We report for the first time the Al and C codoping effect on the structures and superconductivity in MgB2. It was found that both the lattice parameters and the Tc decreased monotonically with increasing doping level of both Al and C. The Tc dropped to 27.5 and 7 K for x=0.2 and for x =0.4, respectively. The reduction of Tc for the codoping was found to be quicker than for individual Al doping and slower than for individual C doping at the same doping levels. First-principles calculations indicated that the observed decrease in Tc …


Nanoconfinement Of Lithium Borohydride In Cu-Mofs Towards Low Temperature Dehydrogenation, W.W Sun, Shaofeng Li, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu, S. X. Dou, Xuebin Yu Jun 2013

Nanoconfinement Of Lithium Borohydride In Cu-Mofs Towards Low Temperature Dehydrogenation, W.W Sun, Shaofeng Li, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu, S. X. Dou, Xuebin Yu

Shi Xue Dou

Successful synthesis and investigation of a new material that uses copper-metal–organic frameworks (Cu-MOFs) as the template for loading LiBH4 are reported. The nanoconfinement of LiBH4 in the pores of Cu-MOFs results in an interaction between LiBH4 and Cu2+ ions, enabling the LiBH4@Cu- MOFs system to achieve a much lower dehydrogenation temperature than pristine LiBH4.


Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou Jun 2013

Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou

Shi Xue Dou

An elaborately designed bilayer consisting of superconducting YBa2Cu3O7-6 (YBCO) and ferromagnetic La0.67Sr0.33MnO3-6 (LSMO) was prepared on a single crystal LaAlO3 substrate by pulsed laser deposition (PLD), with a view to understanding the mechanism behind the influence of superconductor/ferromagnet proximity on the critical current density, Jc. The present bilayer system shows significant modifications in Jc, as evidenced by the suppressed decay of its temperature dependence, as well as the crossing behavior of the magnetic field dependence of Jc at high temperatures. This indicates that enhanced flux pinning emerges at high temperatures, and it is believed to arise from the special magnetic …


Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang Jun 2013

Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang

Shi Xue Dou

"Topological insulators, a new class of condensed matter having bulk insulating states and gapless metallic surface states, have demonstrated fascinating quantum effects. However, the potential practical applications of the topological insulators are still under exploration worldwide. We demonstrate that nanosheets of a Bi2Te3 topological insulator several quintuple layers thick display giant and linear magnetoresistance. The giant and linear magnetoresistance achieved is as high as over 600% at room temperature, with a trend towards further increase at higher temperatures, as well as being weakly temperature-dependent and linear with the field, without any sign of saturation at measured fields up to 13 …


Dependence Of Magnetoelectric Properties On Sintering Temperature For Nano-Sic-Doped Mgb2/Fe Wires Made By Combined In Situ/Ex Situ Process, Wenxian Li, Rong Zeng, Jiazhao Wang, Y Li, S. X. Dou Jun 2013

Dependence Of Magnetoelectric Properties On Sintering Temperature For Nano-Sic-Doped Mgb2/Fe Wires Made By Combined In Situ/Ex Situ Process, Wenxian Li, Rong Zeng, Jiazhao Wang, Y Li, S. X. Dou

Shi Xue Dou

Very fine nano-SiC particles (nm) were doped into a MgB2 superconductor. The influence of self-field supercurrent on the high-field performance of the nano-SiC-doped MgB2/Fe wires is discussed based on comparison of the critical current densities of the in situ processed nano-SiCdoped MgB2 wires and those of the nano-SiC-doped MgB2/Fe wires processed by the combination of in situ/ex situ methods.


Fluctuation Of Mean Free Path And Transition Temperature Induced Vortex Pinning In (Ba,K)Fe2as2 Superconductors, S R. Ghorbani, Xiaolin Wang, Mahboobeh Shahbazi, S. X. Dou, C T. Lin Jun 2013

Fluctuation Of Mean Free Path And Transition Temperature Induced Vortex Pinning In (Ba,K)Fe2as2 Superconductors, S R. Ghorbani, Xiaolin Wang, Mahboobeh Shahbazi, S. X. Dou, C T. Lin

Shi Xue Dou

The vortex pinning mechanisms of Ba0.72K0.28Fe2As2 single crystal have been studied systematically as a function of temperature and magnetic field. The temperature dependence of the critical current density, Jc(T), was analysed within the collective pinning model at different magnetic fields. It was found that both the dl pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation, and the dTc pinning mechanism, which is associated with spatial fluctuations of the transition temperature, coexist in the Ba0.72K0.28Fe2As2 single crystal in fields smaller than 4 T. Their contributions are strongly temperature and magnetic field dependent. At lower temperature and B