Spintronic materials and devices based on antiferromagnetic metals

Directory of Open Access Journals (Sweden)

Y.Y. Wang

2017-04-01

Full Text Available In this paper, we review our recent experimental developments on antiferromagnet (AFM spintronics mainly comprising Mn-based noncollinear AFM metals. IrMn-based tunnel junctions and Hall devices have been investigated to explore the manipulation of AFM moments by magnetic fields, ferromagnetic materials and electric fields. Room-temperature tunneling anisotropic magnetoresistance based on IrMn as well as FeMn has been successfully achieved, and electrical control of the AFM exchange spring is realized by adopting ionic liquid. In addition, promising spin-orbit effects in AFM as well as spin transfer via AFM spin waves reported by different groups have also been reviewed, indicating that the AFM can serve as an efficient spin current source. To explore the crucial role of AFM acting as efficient generators, transmitters, and detectors of spin currents is an emerging topic in the field of magnetism today. AFM metals are now ready to join the rapidly developing fields of basic and applied spintronics, enriching this area of solid-state physics and microelectronics.

A review on organic spintronic materials and devices: II. Magnetoresistance in organic spin valves and spin organic light emitting diodes

Directory of Open Access Journals (Sweden)

Rugang Geng

2016-09-01

Full Text Available In the preceding review paper, Paper I [Journal of Science: Advanced Materials and Devices 1 (2016 128–140], we showed the major experimental and theoretical studies on the first organic spintronic subject, namely organic magnetoresistance (OMAR in organic light emitting diodes (OLEDs. The topic has recently been of renewed interest as a result of a demonstration of the magneto-conductance (MC that exceeds 1000% at room temperature using a certain type of organic compounds and device operating condition. In this report, we will review two additional organic spintronic devices, namely organic spin valves (OSVs where only spin polarized holes exist to cause magnetoresistance (MR, and spin organic light emitting diodes (spin-OLEDs where both spin polarized holes and electrons are injected into the organic emissive layer to form a magneto-electroluminescence (MEL hysteretic loop. First, we outline the major advances in OSV studies for understanding the underlying physics of the spin transport mechanism in organic semiconductors (OSCs and the spin injection/detection at the organic/ferromagnet interface (spinterface. We also highlight some of outstanding challenges in this promising research field. Second, the first successful demonstration of spin-OLEDs is reviewed. We also discuss challenges to achieve the high performance devices. Finally, we suggest an outlook on the future of organic spintronics by using organic single crystals and aligned polymers for the spin transport layer, and a self-assembled monolayer to achieve more controllability for the spinterface.

Spintronics-based computing

CERN Document Server

Prenat, Guillaume

2015-01-01

This book provides a comprehensive introduction to spintronics-based computing for the next generation of ultra-low power/highly reliable logic, which is widely considered a promising candidate to replace conventional, pure CMOS-based logic. It will cover aspects from device to system-level, including magnetic memory cells, device modeling, hybrid circuit structure, design methodology, CAD tools, and technological integration methods. This book is accessible to a variety of readers and little or no background in magnetism and spin electronics are required to understand its content.  The multidisciplinary team of expert authors from circuits, devices, computer architecture, CAD and system design reveal to readers the potential of spintronics nanodevices to reduce power consumption, improve reliability and enable new functionality.  .

Spintronic logic design methodology based on spin Hall effect–driven magnetic tunnel junctions

International Nuclear Information System (INIS)

Kang, Wang; Zhang, Youguang; Zhao, Weisheng; Wang, Zhaohao; Klein, Jacques-Olivier; Lv, Weifeng

2016-01-01

Conventional complementary metal-oxide-semiconductor (CMOS) technology is now approaching its physical scaling limits to enable Moore’s law to continue. Spintronic devices, as one of the potential alternatives, show great promise to replace CMOS technology for next-generation low-power integrated circuits in nanoscale technology nodes. Until now, spintronic memory has been successfully commercialized. However spintronic logic still faces many critical challenges (e.g. direct cascading capability and small operation gain) before it can be practically applied. In this paper, we propose a standard complimentary spintronic logic (CSL) design methodology to form a CMOS-like logic design paradigm. Using the spin Hall effect (SHE)-driven magnetic tunnel junction (MTJ) device as an example, we demonstrate CSL implementation, functionality and performance. This logic family provides a unified design methodology for spintronic logic circuits and partly solves the challenges of direct cascading capability and small operation gain in the previously proposed spintronic logic designs. By solving a modified Landau–Lifshitz–Gilbert equation, the magnetization dynamics in the free layer of the MTJ is theoretically described and a compact electrical model is developed. With this electrical model, numerical simulations have been performed to evaluate the functionality and performance of the proposed CSL design. Simulation results demonstrate that the proposed CSL design paradigm is rather promising for low-power logic computing. (paper)

Focused issue on antiferromagnetic spintronics: An overview (Part of a collection of reviews on antiferromagnetic spintronics)

KAUST Repository

Jungwirth, T.

2017-05-30

This focused issue attempts to provide a comprehensive introduction into the field of antiferromagnetic spintronics. Apart from the brief overview below, it features five review articles. The intention is to cover in a coherent and complementary way key physical aspects of the antiferromagnetic spintronics research. These range from microelectronic memory devices and optical manipulation and detection of antiferromagnetic spins, to the fundamentals of antiferromagnetic dynamics in uniform or spin-textured systems, and to the interplay of antiferromagnetic spintronics with topological phenomena. The antiferromagnetic ordering can take a number of forms including fully compensated collinear, non-collinear, and non-coplanar magnetic lattices, compensated and uncompensated ferrimagnets, or metamagnetic materials hosting an antiferromagnetic to ferromagnetic phase transition. Apart from the variety of distinct magnetic crystal structures, the focused issue also encompasses spintronic phenomena and devices studied in antiferromagnet/ferromagnet heterostructures and in synthetic antiferromagnets.

Focused issue on antiferromagnetic spintronics: An overview (Part of a collection of reviews on antiferromagnetic spintronics)

KAUST Repository

Jungwirth, T.; Sinova, J.; Manchon, Aurelien; Marti, X.; Wunderlich, J.; Felser, C.

2017-01-01

This focused issue attempts to provide a comprehensive introduction into the field of antiferromagnetic spintronics. Apart from the brief overview below, it features five review articles. The intention is to cover in a coherent and complementary way key physical aspects of the antiferromagnetic spintronics research. These range from microelectronic memory devices and optical manipulation and detection of antiferromagnetic spins, to the fundamentals of antiferromagnetic dynamics in uniform or spin-textured systems, and to the interplay of antiferromagnetic spintronics with topological phenomena. The antiferromagnetic ordering can take a number of forms including fully compensated collinear, non-collinear, and non-coplanar magnetic lattices, compensated and uncompensated ferrimagnets, or metamagnetic materials hosting an antiferromagnetic to ferromagnetic phase transition. Apart from the variety of distinct magnetic crystal structures, the focused issue also encompasses spintronic phenomena and devices studied in antiferromagnet/ferromagnet heterostructures and in synthetic antiferromagnets.

Emerging materials and devices in spintronic integrated circuits for energy-smart mobile computing and connectivity

International Nuclear Information System (INIS)

Kang, S.H.; Lee, K.

2013-01-01

A spintronic integrated circuit (IC) is made of a combination of a semiconductor IC and a dense array of nanometer-scale magnetic tunnel junctions. This emerging field is of growing scientific and engineering interest, owing to its potential to bring disruptive device innovation to the world of electronics. This technology is currently being pursued not only for scalable non-volatile spin-transfer-torque magnetoresistive random access memory, but also for various forms of non-volatile logic (Spin-Logic). This paper reviews recent advances in spintronic IC. Key discoveries and breakthroughs in materials and devices are highlighted in light of the broader perspective of their application in low-energy mobile computing and connectivity systems, which have emerged as leading drivers for the prevailing electronics ecosystem

Low intrinsic carrier density LSMO/Alq3/AlOx/Co organic spintronic devices

Science.gov (United States)

Riminucci, Alberto; Graziosi, Patrizio; Calbucci, Marco; Cecchini, Raimondo; Prezioso, Mirko; Borgatti, Francesco; Bergenti, Ilaria; Dediu, Valentin Alek

2018-04-01

The understanding of spin injection and transport in organic spintronic devices is still incomplete, with some experiments showing magnetoresistance and others not detecting it. We have investigated the transport properties of a large number of tris-(8-hydroxyquinoline)aluminum-based organic spintronic devices with an electrical resistance greater than 5 MΩ that did not show magnetoresistance. Their transport properties could be described satisfactorily by known models for organic semiconductors. At high voltages (>2 V), the results followed the model of space charge limited current with a Poole-Frenkel mobility. At low voltages (˜0.1 V), that are those at which the spin valve behavior is usually observed, the charge transport was modelled by nearest neighbor hopping in intra-gap impurity levels, with a charge carrier density of n0 = (1.44 ± 0.21) × 1015 cm-3 at room temperature. Such a low carrier density can explain why no magnetoresistance was observed.

Spintronics

International Nuclear Information System (INIS)

Grundler, Dirk

2003-01-01

Devices that exploit the spin of the electron promise to revolutionize microelectronics once polarized electrons can be injected efficiently into semiconductors at room temperature. Later this year physicists will be celebrating the centenary of Paul Dirac's birth. One of the most influential scientists of the 20th century, Dirac combined quantum mechanics and special relativity to explain the strange magnetic or 'spin' properties of the electron. What Dirac could not have foreseen, however, is how the spin of the electron could change the field of microelectronics. Indeed, the spin of the electron has attracted renewed interest recently because it promises a wide variety of new devices that combine logic, storage and sensor applications. Moreover, these 'Spintronics' devices might lead to quantum computers and quantum communication based on electronic solid-state devices, thus changing the perspective of information technology in the 21st century. Since the 1970s conventional electronic microprocessors have operated by shuttling packets of electronic charge along ever-smaller semiconductor channels. Although this trend will continue for the next few years, experts predict that silicon technology is beginning to approach fundamental limits. By 2008, for example, the width of the 'gate electrodes' in a silicon microprocessor will be just 45 nano metres across, which will place severe demands on the materials and manufacturing techniques used in the semiconductor industry. Indeed, the cost of implementing a new production line for such devices is predicted to reach $33bn. Although successors to silicon technology have been discussed, most of them rely on a complete set of new materials, new handling and processing techniques, and altered circuit design, among other developments. These new technologies include single-electron transistors and molecular-electronic devices based on organic materials or carbon nanotubes (see Carbon nanotubes roll on Physics World June

Handbook of spintronics

CERN Document Server

Awschalom, David; Nitta, Junsaku

2016-01-01

This large reference work addresses a broad range of topics covering various aspects of spintronics science and technology, ranging from fundamental physics through materials properties and processing to established and emerging device technology and applications.  It comprises a collection of chapters from a large international team of leading researchers across academia and industry, providing readers with an up-to-date and comprehensive review of this dynamic field of research.   The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including the theory of giant magnetoresistance and an introduction to spin quantum computing.  Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrid materials including Heusler compounds, magnetic semiconductors, molecular spintronic materials, carbon nanotubes and graphene.  A separate section describes the various methods used in the char...

Optimization of Materials and Interfaces for Spintronic Devices

Science.gov (United States)

Clark, Billy

In recent years' Spintronic devices have drawn a significant amount of research attention. This interest comes in large part from their ability to enable interesting and new technology such as Spin Torque Transfer Random Access Memory or improve existing technology such as High Signal Read Heads for Hard Disk Drives. For the former we worked on optimizing and improving magnetic tunnel junctions by optimizing their thermal stability by using Ta insertion layers in the free layer. We further tried to simplify the design of the MTJ stack by attempting to replace the Co/Pd multilayer with CoPd alloy. In this dissertation, we detail its development and examine the switching characteristics. Lastly we look at a highly spin polarized material, Fe2MnGe, for optimizing Hard Drive Disk read heads.

The role of ion-implantation in the realization of spintronic devices in diamond

Energy Technology Data Exchange (ETDEWEB)

Kalish, Rafi, E-mail: kalish@si-sun1.technion.ac.il [Physics Department and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

2012-02-01

The application of single photons emitted by specific quantum systems is promising for quantum computers, cryptography and for other future nano-applications. These heavily rely on ion implantation both for selective single ion implantations as well as for the introduction of controlled damage with specific properties. Of particular promise is the negatively charged nitrogen-vacancy (NV{sup -}) defect center in diamond. This center has many desirable luminescence properties required for spintronic devices operational at room temperature, including a long relaxation time of the color center, emission of photons in the visible and the fact that it is produced in diamond, a material with outstanding mechanical and optical properties. This center is usually realized by nitrogen and/or vacancy producing ion implantations into diamond which, following annealing, leads to the formation of the desired NV{sup -} center. The single photons emitted by the decay of this center have to be transported to allow their exploitation. This can be best done by realizing very thin wave guides in single crystal diamond with/or without nano-scale cavities in the same diamond in which NV centers are produced. For this, advantage is taken of the unique property of heavily ion-damaged diamond to be converted, following annealing, to etchable graphite. Thus a free standing submicron thick diamond membrane containing the NV center can be obtained. If desirable, specific photonic crystal structures can be realized in them by the use of FIB. The various ion-implantation schemes used to produce NV centers in diamond, free standing diamond membranes, and photonic crystal structures in them are reviewed. The scientific problems and the technological challenges that have to be solved before actual practical realization of diamond based spintronic devices can be produced are discussed.

Boron nitride nanotubes for spintronics.

Science.gov (United States)

Dhungana, Kamal B; Pati, Ranjit

2014-09-22

With the end of Moore's law in sight, researchers are in search of an alternative approach to manipulate information. Spintronics or spin-based electronics, which uses the spin state of electrons to store, process and communicate information, offers exciting opportunities to sustain the current growth in the information industry. For example, the discovery of the giant magneto resistance (GMR) effect, which provides the foundation behind modern high density data storage devices, is an important success story of spintronics; GMR-based sensors have wide applications, ranging from automotive industry to biology. In recent years, with the tremendous progress in nanotechnology, spintronics has crossed the boundary of conventional, all metallic, solid state multi-layered structures to reach a new frontier, where nanostructures provide a pathway for the spin-carriers. Different materials such as organic and inorganic nanostructures are explored for possible applications in spintronics. In this short review, we focus on the boron nitride nanotube (BNNT), which has recently been explored for possible applications in spintronics. Unlike many organic materials, BNNTs offer higher thermal stability and higher resistance to oxidation. It has been reported that the metal-free fluorinated BNNT exhibits long range ferromagnetic spin ordering, which is stable at a temperature much higher than room temperature. Due to their large band gap, BNNTs are also explored as a tunnel magneto resistance device. In addition, the F-BNNT has recently been predicted as an ideal spin-filter. The purpose of this review is to highlight these recent progresses so that a concerted effort by both experimentalists and theorists can be carried out in the future to realize the true potential of BNNT-based spintronics.

Boron Nitride Nanotubes for Spintronics

Directory of Open Access Journals (Sweden)

Kamal B. Dhungana

2014-09-01

Full Text Available With the end of Moore’s law in sight, researchers are in search of an alternative approach to manipulate information. Spintronics or spin-based electronics, which uses the spin state of electrons to store, process and communicate information, offers exciting opportunities to sustain the current growth in the information industry. For example, the discovery of the giant magneto resistance (GMR effect, which provides the foundation behind modern high density data storage devices, is an important success story of spintronics; GMR-based sensors have wide applications, ranging from automotive industry to biology. In recent years, with the tremendous progress in nanotechnology, spintronics has crossed the boundary of conventional, all metallic, solid state multi-layered structures to reach a new frontier, where nanostructures provide a pathway for the spin-carriers. Different materials such as organic and inorganic nanostructures are explored for possible applications in spintronics. In this short review, we focus on the boron nitride nanotube (BNNT, which has recently been explored for possible applications in spintronics. Unlike many organic materials, BNNTs offer higher thermal stability and higher resistance to oxidation. It has been reported that the metal-free fluorinated BNNT exhibits long range ferromagnetic spin ordering, which is stable at a temperature much higher than room temperature. Due to their large band gap, BNNTs are also explored as a tunnel magneto resistance device. In addition, the F-BNNT has recently been predicted as an ideal spin-filter. The purpose of this review is to highlight these recent progresses so that a concerted effort by both experimentalists and theorists can be carried out in the future to realize the true potential of BNNT-based spintronics.

All-spin logic operations: Memory device and reconfigurable computing

Science.gov (United States)

Patra, Moumita; Maiti, Santanu K.

2018-02-01

Exploiting spin degree of freedom of electron a new proposal is given to characterize spin-based logical operations using a quantum interferometer that can be utilized as a programmable spin logic device (PSLD). The ON and OFF states of both inputs and outputs are described by spin state only, circumventing spin-to-charge conversion at every stage as often used in conventional devices with the inclusion of extra hardware that can eventually diminish the efficiency. All possible logic functions can be engineered from a single device without redesigning the circuit which certainly offers the opportunities of designing new generation spintronic devices. Moreover, we also discuss the utilization of the present model as a memory device and suitable computing operations with proposed experimental setups.

Spintronics with multiferroics

Science.gov (United States)

Béa, H.; Gajek, M.; Bibes, M.; Barthélémy, A.

2008-10-01

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO3 and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO3 allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO3 ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO3 as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO3 electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO3 ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Spintronics with multiferroics

International Nuclear Information System (INIS)

Bea, H; Gajek, M; Bibes, M; Barthelemy, A

2008-01-01

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO 3 and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO 3 allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO 3 ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO 3 as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO 3 electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO 3 ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Spintronics with multiferroics

Energy Technology Data Exchange (ETDEWEB)

Bea, H; Gajek, M; Bibes, M; Barthelemy, A [Unite Mixte de Physique CNRS/Thales, Route departementale 128, F-91767 Palaiseau (France); Universite Paris-Sud, 91405 Orsay (France)], E-mail: agnes.barthelemy@thalesgroup.com

2008-10-29

In this paper, we review the recent research on the functionalization of multiferroics for spintronics applications. We focus more particularly on antiferromagnetic and ferroelectric BiFeO{sub 3} and its integration in several types of architectures. For instance, when used as a tunnel barrier, BiFeO{sub 3} allows the observation of a large tunnel magnetoresistance with Co and (La,Sr)MnO{sub 3} ferromagnetic electrodes. Also, its antiferromagnetic and magnetoelectric properties have been exploited to induce an exchange coupling with a ferromagnet. The mechanisms of such an exchange coupling open ways to electrically control magnetization and possibly the logic state of spintronics devices. We also discuss recent results concerning the use of ferromagnetic and ferroelectric (La,Bi)MnO{sub 3} as an active tunnel barrier in magnetic tunnel junctions with Au and (La,Sr)MnO{sub 3} electrodes. A four-resistance-state device has been obtained, with two states arising from a spin filtering effect due to the ferromagnetic character of the barrier and two resulting from the ferroelectric behavior of the (La,Bi)MnO{sub 3} ultrathin film. These results show that the additional degree of freedom provided by the ferroelectric polarization brings novel functionalities to spintronics, either as a extra order parameter for multiple-state memory elements, or as a handle for gate-controlled magnetic memories.

Spintronics Based on Topological Insulators

Science.gov (United States)

Fan, Yabin; Wang, Kang L.

2016-10-01

Spintronics using topological insulators (TIs) as strong spin-orbit coupling (SOC) materials have emerged and shown rapid progress in the past few years. Different from traditional heavy metals, TIs exhibit very strong SOC and nontrivial topological surface states that originate in the bulk band topology order, which can provide very efficient means to manipulate adjacent magnetic materials when passing a charge current through them. In this paper, we review the recent progress in the TI-based magnetic spintronics research field. In particular, we focus on the spin-orbit torque (SOT)-induced magnetization switching in the magnetic TI structures, spin-torque ferromagnetic resonance (ST-FMR) measurements in the TI/ferromagnet structures, spin pumping and spin injection effects in the TI/magnet structures, as well as the electrical detection of the surface spin-polarized current in TIs. Finally, we discuss the challenges and opportunities in the TI-based spintronics field and its potential applications in ultralow power dissipation spintronic memory and logic devices.

Organic-based magnon spintronics

Science.gov (United States)

Liu, Haoliang; Zhang, Chuang; Malissa, Hans; Groesbeck, Matthew; Kavand, Marzieh; McLaughlin, Ryan; Jamali, Shirin; Hao, Jingjun; Sun, Dali; Davidson, Royce A.; Wojcik, Leonard; Miller, Joel S.; Boehme, Christoph; Vardeny, Z. Valy

2018-03-01

Magnonics concepts utilize spin-wave quanta (magnons) for information transmission, processing and storage. To convert information carried by magnons into an electric signal promises compatibility of magnonic devices with conventional electronic devices, that is, magnon spintronics1. Magnons in inorganic materials have been studied widely with respect to their generation2,3, transport4,5 and detection6. In contrast, resonant spin waves in the room-temperature organic-based ferrimagnet vanadium tetracyanoethylene (V(TCNE)x (x ≈ 2)), were detected only recently7. Herein we report room-temperature coherent magnon generation, transport and detection in films and devices based on V(TCNE)x using three different techniques, which include broadband ferromagnetic resonance (FMR), Brillouin light scattering (BLS) and spin pumping into a Pt adjacent layer. V(TCNE)x can be grown as neat films on a large variety of substrates, and it exhibits extremely low Gilbert damping comparable to that in yttrium iron garnet. Our studies establish an alternative use for organic-based magnets, which, because of their synthetic versatility, may substantially enrich the field of magnon spintronics.

Bipolar spintronics: from spin injection to spin-controlled logic

International Nuclear Information System (INIS)

Zutic, Igor; Fabian, Jaroslav; Erwin, Steven C

2007-01-01

An impressive success of spintronic applications has been typically realized in metal-based structures which utilize magnetoresistive effects for substantial improvements in the performance of computer hard drives and magnetic random access memories. Correspondingly, the theoretical understanding of spin-polarized transport is usually limited to a metallic regime in a linear response, which, while providing a good description for data storage and magnetic memory devices, is not sufficient for signal processing and digital logic. In contrast, much less is known about possible applications of semiconductor-based spintronics and spin-polarized transport in related structures which could utilize strong intrinsic nonlinearities in current-voltage characteristics to implement spin-based logic. Here we discuss the challenges for realizing a particular class of structures in semiconductor spintronics: our proposal for bipolar spintronic devices in which carriers of both polarities (electrons and holes) contribute to spin-charge coupling. We formulate the theoretical framework for bipolar spin-polarized transport, and describe several novel effects in two- and three-terminal structures which arise from the interplay between nonequilibrium spin and equilibrium magnetization

Large resistance change on magnetic tunnel junction based molecular spintronics devices

Science.gov (United States)

Tyagi, Pawan; Friebe, Edward

2018-05-01

Molecular bridges covalently bonded to two ferromagnetic electrodes can transform ferromagnetic materials and produce intriguing spin transport characteristics. This paper discusses the impact of molecule induced strong coupling on the spin transport. To study molecular coupling effect the octametallic molecular cluster (OMC) was bridged between two ferromagnetic electrodes of a magnetic tunnel junction (Ta/Co/NiFe/AlOx/NiFe/Ta) along the exposed side edges. OMCs induced strong inter-ferromagnetic electrode coupling to yield drastic changes in transport properties of the magnetic tunnel junction testbed at the room temperature. These OMCs also transformed the magnetic properties of magnetic tunnel junctions. SQUID and ferromagnetic resonance studies provided insightful data to explain transport studies on the magnetic tunnel junction based molecular spintronics devices.

Spin-filter scanning tunneling microscopy : a novel technique for the analysis of spin polarization on magnetic surfaces and spintronic devices

NARCIS (Netherlands)

Vera Marun, I.J.

2010-01-01

This thesis deals with the development of a versatile technique to measure spin polarization with atomic resolution. A microscopy technique that can measure electronic spin polarization is relevant for characterization of magnetic nanostructures and spintronic devices. Scanning tunneling microscopy

Molecular spintronics using single-molecule magnets

Science.gov (United States)

Bogani, Lapo; Wernsdorfer, Wolfgang

2008-03-01

A revolution in electronics is in view, with the contemporary evolution of the two novel disciplines of spintronics and molecular electronics. A fundamental link between these two fields can be established using molecular magnetic materials and, in particular, single-molecule magnets. Here, we review the first progress in the resulting field, molecular spintronics, which will enable the manipulation of spin and charges in electronic devices containing one or more molecules. We discuss the advantages over more conventional materials, and the potential applications in information storage and processing. We also outline current challenges in the field, and propose convenient schemes to overcome them.

Semiconductor spintronics

CERN Document Server

Xia, Jianbai; Chang, Kai

2012-01-01

Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.

Spintronics

Indian Academy of Sciences (India)

we will deal in an elementary fashion with the principles of spintronics. Introduction. Spintronics is the branch of science dealing with the ac- tive manipulation of spin degrees of freedom in solid state materials. .... polarized material can be done in many ways. The sim- plest way is to apply a transient magnetic field to a para-.

"Magnon Spintronics"

Science.gov (United States)

Yu, Haiming; Xiao, Jiang; Pirro, Philipp

2018-03-01

We are proud to present a collection of 12 cutting-edge research articles on the emerging field "magnon spintronics" investigating the properties of spin waves or magnons towards their potential applications in low-power-consumption information technologies. Magnons (quasiparticles of spin waves) are collective excitations of magnetizations in a magnetic system. The concept for such excitations was first introduced 1930 by Felix Bloch [1] who described ferromagnetism in a lattice. The field of magnon spintronics [2] or magnonics [3] aims at utilizing magnons to realize information processing and storage. The propagation of spin waves is free of charge transport, hence a successful realization of magnonic devices can innately avoid Joule heating induced energy loss in nowadays micro- or nano-electronic devices. Magnonics has made many progresses in recent years, including the demonstration of magnonic logic devices [4]. Towards the aim to generate magnonic devices, it is an essential step to find materials suitable for conveying spin waves. One outstanding candidate is a ferromagnetic insulator yttrium iron garnet (YIG). It offers an out standing low damping which allows the propagation of spin waves over relatively long distances. Experiments on such a thin YIG film with an out-of-plane magnetization have been performed by Chen et al. [5]. They excited so called forward volume mode spin waves and determined the propagating spin wave properties, such as the group velocities. Lohman et al. [6] has successfully imaged the propagating spin waves using time-resolved MOKE microscopy and show agreement with micromagnetic modellings. For very long time, YIG is the most ideal material for spin waves thanks to its ultra-low damping. However, it remains a major challenge integrate YIG on to Silicon substrate. Magnetic Heusler alloys on the other hand, can be easily grown on Si substrate and also shows reasonably good damping properties, which allow spin waves to propagate

A general circuit model for spintronic devices under electric and magnetic fields

KAUST Repository

Alawein, Meshal

2017-10-25

In this work, we present a circuit model of diffusive spintronic devices capable of capturing the effects of both electric and magnetic fields. Starting from a modified version of the well-established drift-diffusion equations, we derive general equivalent circuit models of semiconducting/metallic nonmagnets and metallic ferromagnets. In contrast to other models that are based on steady-state transport equations which might also neglect certain effects such as thermal fluctuations, spin dissipation in the ferromagnets, and spin precession under magnetic fields, our model incorporates most of the important physics and is based on a time-dependent formulation. An application of our model is shown through simulations of a nonlocal spin-valve under the presence of a magnetic field, where we reproduce experimental results of electrical measurements that demonstrate the phenomena of spin precession and dephasing (“Hanle effect”).

Semiconductors put spin in spintronics

International Nuclear Information System (INIS)

Weiss, Dieter

2000-01-01

Electrons and holes, which carry the current in semiconductor devices, are quantum-mechanical objects characterized by a set of quantum numbers - the band index, the wave-vector (which is closely related to the electron or hole velocity) and spin. The spin, however, is one of the strangest properties of particles. In simple terms, we can think of the spin as an internal rotation of the electron, but it has no classical counterpart. The spin is connected to a quantized magnetic moment and hence acts as a microscopic magnet. Thus the electron spin can adopt one of two directions (''up'' or ''down'') in a magnetic field. The spin plays no role in conventional electronics and the current in any semiconductor device is made up of a mixture of electrons with randomly oriented spins. However, a new range of electronic devices that transport the spin of the electrons, in addition to their charge, is being developed. But the biggest obstacle to making practical ''spin electronic'' or ''spintronic'' devices so far has been finding a way of injecting spin-polarized electrons or holes into the semiconductor and then detecting them. Recently a team of physicists from the University of Wuerzburg in Germany, and also a collaboration of researchers from Tohoku University in Japan and the University of California at Santa Barbara, have found a way round these problems using either semi-magnetic or ferromagnetic semiconductors as ''spin aligners'' (R Fiederling et al. 1999 Nature 402 787; Y Ohno et al. 1999 Nature 402 790). In this article the author presents the latest breakthrough in spintronics research. (UK)

Organic spintronics

International Nuclear Information System (INIS)

Naber, W J M; Faez, S; Wiel, W G van der

2007-01-01

We review the emerging field of organic spintronics, where organic materials are applied as a medium to transport and control spin-polarized signals. The contacts for injecting and detecting spins are formed by ferromagnetic metals, oxides, or inorganic semiconductors. First, the basic concepts of spintronics and organic electronics are addressed, and phenomena which are in particular relevant for organic spintronics are highlighted. Experiments using different organic materials, including carbon nanotubes, organic thin films, self-assembled monolayers and single molecules are then reviewed. Observed magnetoresistance points toward successful spin injection and detection, but spurious magnetoresistance effects can easily be confused with spin accumulation. A few studies report long spin relaxation times and lengths, which forms a promising basis for further research. We conclude with discussing outstanding questions and problems. (topical review)

Perspective: Ultrafast magnetism and THz spintronics

Energy Technology Data Exchange (ETDEWEB)

Walowski, Jakob; Münzenberg, Markus [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2016-10-14

This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

Perspective: Ultrafast magnetism and THz spintronics

International Nuclear Information System (INIS)

Walowski, Jakob; Münzenberg, Markus

2016-01-01

This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

Topological insulator materials and nanostructures for future electronics, spintronics and energy conversion

International Nuclear Information System (INIS)

Kantser, Valeriu

2011-01-01

Two fundamental electrons attributes in materials and nanostructures - charge and spin - determine their electronic properties. The processing of information in conventional electronic devices is based only on the charge of the electrons. Spin electronics, or spintronics, uses the spin of electrons, as well as their charge, to process information. Metals, semiconductors and insulators are the basic materials that constitute the components of electronic devices, and these have been transforming all aspects of society for over a century. In contrast, magnetic metals, half-metals, magnetic semiconductors, dilute magnetic semiconductors and magnetic insulators are the materials that will form the basis for spintronic devices. Materials with topological band structure attributes and having a zero-energy band gap surface states are a special class of these materials that exhibit some fascinating and superior electronic properties compared to conventional materials allowing to combine both charge and spin functionalities. This article reviews a range of topological insulator materials and nanostructures with tunable surface states, focusing on nanolayered and nanowire like structures. These materials and nanostructures all have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors.

Spintronics: The molecular way

Science.gov (United States)

Cornia, Andrea; Seneor, Pierre

2017-05-01

Molecular spintronics is an interdisciplinary field at the interface between organic spintronics, molecular magnetism, molecular electronics and quantum computing, which is advancing fast and promises large technological payoffs.

Damping constant measurement and inverse giant magnetoresistance in spintronic devices with Fe4N

Directory of Open Access Journals (Sweden)

Xuan Li

2017-12-01

Full Text Available Fe4N is one of the attractive materials for spintronic devices due to its large spin asymmetric conductance and negative spin polarization at the Fermi level. We have successfully deposited Fe4N thin film with (001 out-of-plane orientation using a DC facing-target-sputtering system. A Fe(001/Ag(001 composite buffer layer is selected to improve the (001 orientation of the Fe4N thin film. The N2 partial pressure during sputtering is optimized to promote the formation of Fe4N phase. Moreover, we have measured the ferromagnetic resonance (FMR of the (001 oriented Fe4N thin film using coplanar waveguides and microwave excitation. The resonant fields are tested under different microwave excitation frequencies, and the experimental results match well with the Kittel formula. The Gilbert damping constant of Fe4N is determined to be α = 0.021±0.02. We have also fabricated and characterized the current-perpendicular-to-plane (CPP giant magnetoresistance (GMR device with Fe4N/Ag/Fe sandwich. Inverse giant magnetoresistance is observed in the CPP GMR device, which suggests that the spin polarization of Fe4N and Fe4N/Ag interface is negative.

Flexible spin-orbit torque devices

Energy Technology Data Exchange (ETDEWEB)

Lee, OukJae; You, Long; Jang, Jaewon; Subramanian, Vivek [Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720 (United States); Salahuddin, Sayeef [Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2015-12-21

We report on state-of-the-art spintronic devices synthesized and fabricated directly on a flexible organic substrate. Large perpendicular magnetic anisotropy was achieved in ultrathin ferromagnetic heterostructures of Pt/Co/MgO sputtered on a non-rigid plastic substrate at room temperature. Subsequently, a full magnetic reversal of the Co was observed by exploiting the spin orbit coupling in Pt that leads to a spin accumulation at the Pt/Co interface when an in-plane current is applied. Quasi-static measurements show the potential for operating these devices at nano-second speeds. Importantly, the behavior of the devices remained unchanged under varying bending conditions (up to a bending radius of ≈ ±20–30 mm). Furthermore, the devices showed robust operation even after application of 10{sup 6} successive pulses, which is likely sufficient for many flexible applications. Thus, this work demonstrates the potential for integrating high performance spintronic devices on flexible substrates, which could lead to many applications ranging from flexible non-volatile magnetic memory to local magnetic resonance imaging.

Flexible spin-orbit torque devices

International Nuclear Information System (INIS)

Lee, OukJae; You, Long; Jang, Jaewon; Subramanian, Vivek; Salahuddin, Sayeef

2015-01-01

We report on state-of-the-art spintronic devices synthesized and fabricated directly on a flexible organic substrate. Large perpendicular magnetic anisotropy was achieved in ultrathin ferromagnetic heterostructures of Pt/Co/MgO sputtered on a non-rigid plastic substrate at room temperature. Subsequently, a full magnetic reversal of the Co was observed by exploiting the spin orbit coupling in Pt that leads to a spin accumulation at the Pt/Co interface when an in-plane current is applied. Quasi-static measurements show the potential for operating these devices at nano-second speeds. Importantly, the behavior of the devices remained unchanged under varying bending conditions (up to a bending radius of ≈ ±20–30 mm). Furthermore, the devices showed robust operation even after application of 10 6 successive pulses, which is likely sufficient for many flexible applications. Thus, this work demonstrates the potential for integrating high performance spintronic devices on flexible substrates, which could lead to many applications ranging from flexible non-volatile magnetic memory to local magnetic resonance imaging

Simulation of a spintronic transistor: A study of its performance

International Nuclear Information System (INIS)

Pela, R.R.; Teles, L.K.

2009-01-01

We study theoretically the magnetic bipolar transistor, and compare its performance with common bipolar transistor. We present not only the simulation results for the characteristic curves, but also other relevant parameters related with its performance, such as: the current amplification factor, the open-loop gain, the hybrid parameters and the cutoff frequency. We noted that the spin-charge coupling introduces new phenomena that enrich the functionality characteristics of the magnetic bipolar transistor. Among other things, it has an adjustable band structure, which may be modified during the device operation; it exhibits the already known spin-voltaic effect. On the other hand, we observed that it is necessary a large g-factor to analyze the influence of the field B over the transistor. Nevertheless, we consider the magnetic bipolar transistor as a promising device for spintronic applications

Superconducting spin switch based on superconductor-ferromagnet nanostructures for spintronics

International Nuclear Information System (INIS)

Kehrle, Jan; Mueller, Claus; Obermeier, Guenter; Schreck, Matthias; Gsell, Stefan; Horn, Siegfried; Tidecks, Reinhard; Zdravkov, Vladimir; Morari, Roman; Sidorencko, Anatoli; Prepelitsa, Andrei; Antropov, Evgenii; Socrovisciiuc, Alexei; Nold, Eberhard; Tagirov, Lenar

2011-01-01

Very rapid developing area, spintronics, needs new devices, based on new physical principles. One of such devices - a superconducting spin-switch, consists of ferromagnetic and superconducting layers, and is based on a new phenomenon - reentrant superconductivity. The tuning of the superconducting and ferromagnetic layers thickness is investigated to optimize superconducting spin-switch effect for Nb/Cu 41 Ni 59 based nanoscale layered systems.

Recent Advance in Organic Spintronics and Magnetic Field Effect

Science.gov (United States)

Valy Vardeny, Z.

2013-03-01

In this talk several important advances in the field of Organic Spintronics and magnetic field effect (MFE) of organic films and optoelectronic devices that have occurred during the past two years from the Utah group will be surveyed and discussed. (i) Organic Spintronics: We demonstrated spin organic light emitting diode (spin-OLED) using two FM injecting electrodes, where the electroluminescence depends on the mutual orientation of the electrode magnetization directions. This development has opened up research studies into organic spin-valves (OSV) in the space-charge limited current regime. (ii) Magnetic field effect: We demonstrated that the photoinduced absorption spectrum in organic films (where current is not involved) show pronounced MFE. This unravels the underlying mechanism of the MFE in organic devices, to be more in agreement with the field of MFE in Biochemistry. (iii) Spin effects in organic optoelectronic devices: We demonstrated that certain spin 1/2 radical additives to donor-acceptor blends substantially enhance the power conversion efficiency of organic photovoltaic (OPV) solar cells. This effect shows that studies of spin response and MFE in OPV devices are promising. In collaboration with T. Nguyen, E. Ehrenfreund, B. Gautam, Y. Zhang and T. Basel. Supported by the DOE grant 04ER46109 ; NSF Grant # DMR-1104495 and MSF-MRSEC program DMR-1121252 [2,3].

Electronic structure and magnetism of new ilmenite compounds for spintronic devices: FeBO{sub 3} (B = Ti, Hf, Zr, Si, Ge, Sn)

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, R.A.P. [Department of Chemistry, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil); Camilo, A. [Department of Physics, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil); Lazaro, S.R. de, E-mail: srlazaro@uepg.br [Department of Chemistry, State University of Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, PR (Brazil)

2015-11-15

First-principles calculations were performed in the framework of Density Functional Theory (DFT) within hybrid functional (B3LYP) to study the electronic structure and magnetic properties of new ilmenite FeBO{sub 3} (B=Ti, Hf, Zr, Si, Ge, Sn) materials. In particular, the magnetic exchange interaction between Fe{sup 2+} layers is dependent on the interlayer distance and it can be controlled by ionic radius of B-site cation. Thus, Fe(Ti, Si, Ge)O{sub 3} are antiferromagnetic materials, while Fe(Zr, Hf, Sn)O{sub 3} are ferromagnetic. We also argue that antiferromagnetic materials and FeZrO{sub 3} are convectional semiconductors, whereas FeHfO{sub 3} and FeSnO{sub 3} exhibit intrinsic half-metallic behavior, making them promising candidates for spintronic devices. - Highlights: • We study electronic structure and magnetism of new FeBO{sub 3} (B=Ti, Hf, Zr, Si, Ge, Sn) ilmenite materials. • We found that magnetic ordering of Fe-based ilmenite materials can be controlled by size of B-site cation. • Fe(Ti, Zr, Si, Ge)O{sub 3} are convectional semiconductors. • FeHfO{sub 3} and FeSnO{sub 3} exhibit intrinsic half-metallic behavior with potential application for spintronic devices.

Integration of spintronic interface for nanomagnetic arrays

Directory of Open Access Journals (Sweden)

Andrew Lyle

2011-12-01

Full Text Available An experimental demonstration utilizing a spintronic input/output (I/O interface for arrays of closely spaced nanomagnets is presented. The free layers of magnetic tunnel junctions (MTJs form dipole coupled nanomagnet arrays which can be applied to different contexts including Magnetic Quantum Cellular Automata (MQCA for logic applications and self-biased devices for field sensing applications. Dipole coupled nanomagnet arrays demonstrate adaptability to a variety of contexts due to the ability for tuning of magnetic response. Spintronics allows individual nanomagnets to be manipulated with spin transfer torque and monitored with magnetoresistance. This facilitates measurement of the magnetic coupling which is important for (yet to be demonstrated data propagation reliability studies. In addition, the same magnetic coupling can be tuned to reduce coercivity for field sensing. Dipole coupled nanomagnet arrays have the potential to be thousands of times more energy efficient than CMOS technology for logic applications, and they also have the potential to form multi-axis field sensors.

Advances in graphene spintronics

Science.gov (United States)

van Wees, Bart

I will give an overview of the status of graphene spintronics, from both scientific as technological perspectives. In the introduction I will show that (single) layer graphene is the ideal host for electronic spins, allowing spin transport by diffusion over distances exceeding 20 micrometers at room temperature. I will show how by the use of carrier drift, induced by charge currents, effective spin relaxation lengths of 90 micrometer can be obtained in graphene encapsulated between boron-nitride layers. This also allows the controlled flow and guiding of spin currents, opening new avenues for spin logic devices based on lateral architectures. By preparing graphene on top of a ferromagnetic insulator (yttrium iron garnet (YIG)) we have shown that we can induce an exchange interaction in the graphene, thus effectively making the graphene magnetic. This allows for new ways to induce and control spin precession for new applications. Finally I will show how, by using two-layer BN tunnel barriers, spins can be injected from a ferromagnet into graphene with a spin polarization which can be tuned continuously from -80% to 40%, using a bias range from -0.3V to 0.3V across the barrier. These unique record values of the spin polarization are not yet understood, but they highlight the potential of Van der Waals stacking of graphene and related 2D materials for spintronics.

Nanomagnetism and spintronics

CERN Document Server

Shinjo, Teruya

2014-01-01

The concise and accessible chapters of Nanomagnetism and Spintronics, Second Edition, cover the most recent research in areas of spin-current generation, spin-calorimetric effect, voltage effects on magnetic properties, spin-injection phenomena, giant magnetoresistance (GMR), and tunnel magnetoresistance (TMR). Spintronics is a cutting-edge area in the field of magnetism that studies the interplay of magnetism and transport phenomena, demonstrating how electrons not only have charge but also spin. This second edition provides the background to understand this novel physical phenomeno

Antiferromagnetic spintronics

KAUST Repository

Baltz, V.

2018-02-15

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and

Antiferromagnetic spintronics

KAUST Repository

Baltz, V.; Manchon, Aurelien; Tsoi, M.; Moriyama, T.; Ono, T.; Tserkovnyak, Y.

2018-01-01

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and

Addressing the challenges of using ferromagnetic electrodes in the magnetic tunnel junction-based molecular spintronics devices

International Nuclear Information System (INIS)

Tyagi, Pawan; Friebe, Edward; Baker, Collin

2015-01-01

Addressing the challenges of using high-Curie temperature ferromagnetic (FM) electrodes is critical for molecular spintronics devices (MSDs) research. Two FM electrodes simultaneously chemically bonded with a thiol-functionalized molecule can produce novel MSDs to exploring new quantum mechanical phenomenon and computer technologies. For developing a commercially viable MSD, it is crucial to developing a device fabrication scheme that carefully considers FM electrodes’ susceptibility to oxidation, chemical etching, and stress-induced deformations during fabrication and usage. This paper studies NiFe, an alloy extensively used in present-day memory devices and high-temperature engineering applications, as a candidate FM electrode for the fabrication of MSDs. Our spectroscopic reflectance studies show that NiFe oxidized aggressively after heating beyond ∼90 °C. The NiFe surfaces, aged for several months or heated for several minutes below ∼90 °C, exhibited remarkable electrochemical activity and were found suitable for chemical bonding with the thiol-functionalized molecular device elements. NiFe also demonstrated excellent etching resistance against commonly used solvents and lithography related chemicals. Additionally, NiFe mitigated the adverse effects of mechanical stress by subsiding the stress-induced deformities. A magnetic tunnel junction-based MSD approach was designed by carefully considering the merits and limitations of NiFe. The device fabrication protocol considers the safe temperature limit to avoiding irreversible surface oxidation, the effect of mechanical stresses, surface roughness, and chemical etching. This paper provides foundational experimental insights in realizing a versatile MSD allowing a wide range of transport and magnetic studies

Multi-parameter optimization of a nanomagnetic system for spintronic applications

International Nuclear Information System (INIS)

Morales Meza, Mishel; Zubieta Rico, Pablo F.; Horley, Paul P.; Sukhov, Alexander; Vieira, Vítor R.

2014-01-01

Magnetic properties of nano-particles feature many interesting physical phenomena that are essentially important for the creation of a new generation of spin-electronic devices. The magnetic stability of the nano-particles can be improved by formation of ordered particle arrays, which should be optimized over several parameters. Here we report successful optimization regarding inter-particle distance and applied field frequency allowing to obtain about three-times reduction of coercivity of a particle array compared to that of a single particle, which opens new perspectives for development of new spintronic devices

Multi-parameter optimization of a nanomagnetic system for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Morales Meza, Mishel [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Zubieta Rico, Pablo F. [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV) Querétaro, Libramiento Norponiente 2000, Fracc. Real de Juriquilla, 76230 Querétaro (Mexico); Horley, Paul P., E-mail: paul.horley@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Sukhov, Alexander [Institut für Physik, Martin-Luther Universität Halle-Wittenberg, 06120 Halle (Saale) (Germany); Vieira, Vítor R. [Centro de Física das Interacções Fundamentais (CFIF), Instituto Superior Técnico, Universidade Técnica de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal)

2014-11-15

Magnetic properties of nano-particles feature many interesting physical phenomena that are essentially important for the creation of a new generation of spin-electronic devices. The magnetic stability of the nano-particles can be improved by formation of ordered particle arrays, which should be optimized over several parameters. Here we report successful optimization regarding inter-particle distance and applied field frequency allowing to obtain about three-times reduction of coercivity of a particle array compared to that of a single particle, which opens new perspectives for development of new spintronic devices.

Perspectives of antiferromagnetic spintronics

Science.gov (United States)

Jungfleisch, Matthias B.; Zhang, Wei; Hoffmann, Axel

2018-04-01

Antiferromagnets are promising for future spintronic applications owing to their advantageous properties: They are magnetically ordered, but neighboring magnetic moments point in opposite directions, which results in zero net magnetization. This means antiferromagnets produce no stray fields and are insensitive to external magnetic field perturbations. Furthermore, they show intrinsic high frequency dynamics, exhibit considerable spin-orbit and magneto-transport effects. Over the past decade, it has been realized that antiferromagnets have more to offer than just being utilized as passive components in exchange bias applications. This development resulted in a paradigm shift, which opens the pathway to novel concepts using antiferromagnets for spin-based technologies and applications. This article gives a broad perspective on antiferromagnetic spintronics. In particular, the manipulation and detection of antiferromagnetic states by spintronics effects, as well as spin transport and dynamics in antiferromagnetic materials will be discussed. We will also outline current challenges and future research directions in this emerging field.

Perspectives of antiferromagnetic spintronics

Energy Technology Data Exchange (ETDEWEB)

Jungfleisch, Matthias B.; Zhang, Wei; Hoffmann, Axel

2018-04-01

Antiferromagnets are promising for future spintronics applications owing to their interesting properties: They are magnetically ordered, but neighboring magnetic moments point in opposite directions which results in zero net magneti- zation. This means antiferromagnets produce no stray fields and are insensitive to external magnetic field perturbations. Furthermore, they show intrinsic high frequency dynamics, exhibit considerable spin-orbit and magneto-transport effects. Over the past decade, it has been realized that antiferromagnets have more to offer than just being utilized as passive components in exchange bias applications. This development resulted in a paradigm shift, which opens the pathway to novel concepts using antiferromagnets for spin-based technologies and applications. This article gives a broad per- spective on antiferromagnetic spintronics. In particular, the manipulation and detection of anitferromagnetic states by spintronics effects, as well as spin transport and dynamics in antiferromagnetic materials will be discussed. We will also outline current challenges and future research directions in this emerging field.

Neuromorphic computing with nanoscale spintronic oscillators.

Science.gov (United States)

Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie

2017-07-26

Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 10 8 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

Giant magnetoresistance in lateral metallic nanostructures for spintronic applications.

Science.gov (United States)

Zahnd, G; Vila, L; Pham, V T; Marty, A; Beigné, C; Vergnaud, C; Attané, J P

2017-08-25

In this letter, we discuss the shift observed in spintronics from the current-perpendicular-to-plane geometry towards lateral geometries, illustrating the new opportunities offered by this configuration. Using CoFe-based all-metallic LSVs, we show that giant magnetoresistance variations of more than 10% can be obtained, competitive with the current-perpendicular-to-plane giant magnetoresistance. We then focus on the interest of being able to tailor freely the geometries. On the one hand, by tailoring the non-magnetic parts, we show that it is possible to enhance the spin signal of giant magnetoresistance structures. On the other hand, we show that tailoring the geometry of lateral structures allows creating a multilevel memory with high spin signals, by controlling the coercivity and shape anisotropy of the magnetic parts. Furthermore, we study a new device in which the magnetization direction of a nanodisk can be detected. We thus show that the ability to control the magnetic properties can be used to take advantage of all the spin degrees of freedom, which are usually occulted in current-perpendicular-to-plane devices. This flexibility of lateral structures relatively to current-perpendicular-to-plane structures is thus found to offer a new playground for the development of spintronic applications.

Antiferromagnetic spintronics

Science.gov (United States)

Baltz, V.; Manchon, A.; Tsoi, M.; Moriyama, T.; Ono, T.; Tserkovnyak, Y.

2018-01-01

Antiferromagnetic materials could represent the future of spintronic applications thanks to the numerous interesting features they combine: they are robust against perturbation due to magnetic fields, produce no stray fields, display ultrafast dynamics, and are capable of generating large magnetotransport effects. Intense research efforts over the past decade have been invested in unraveling spin transport properties in antiferromagnetic materials. Whether spin transport can be used to drive the antiferromagnetic order and how subsequent variations can be detected are some of the thrilling challenges currently being addressed. Antiferromagnetic spintronics started out with studies on spin transfer and has undergone a definite revival in the last few years with the publication of pioneering articles on the use of spin-orbit interactions in antiferromagnets. This paradigm shift offers possibilities for radically new concepts for spin manipulation in electronics. Central to these endeavors are the need for predictive models, relevant disruptive materials, and new experimental designs. This paper reviews the most prominent spintronic effects described based on theoretical and experimental analysis of antiferromagnetic materials. It also details some of the remaining bottlenecks and suggests possible avenues for future research. This review covers both spin-transfer-related effects, such as spin-transfer torque, spin penetration length, domain-wall motion, and "magnetization" dynamics, and spin-orbit related phenomena, such as (tunnel) anisotropic magnetoresistance, spin Hall, and inverse spin galvanic effects. Effects related to spin caloritronics, such as the spin Seebeck effect, are linked to the transport of magnons in antiferromagnets. The propagation of spin waves and spin superfluids in antiferromagnets is also covered.

Heterojunction metal-oxide-metal Au-Fe{sub 3}O{sub 4}-Au single nanowire device for spintronics

Energy Technology Data Exchange (ETDEWEB)

Reddy, K. M., E-mail: mrkongara@boisestate.edu; Punnoose, Alex; Hanna, Charles [Department of Physics, Boise State University, Boise, Idaho 83725 (United States); Padture, Nitin P. [School of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

2015-05-07

In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe{sub 3}O{sub 4} interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current–voltage (I-V) characteristics of a single Au-Fe{sub 3}O{sub 4}-Au nanowire have exhibited Ohmic behavior. Anomalous positive magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe{sub 3}O{sub 4} phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe{sub 3}O{sub 4} and well defined electrode contact metal (Au)–magnetite interface, which helps in attaining high spin polarized current.

A review on organic spintronic materials and devices: I. Magnetic field effect on organic light emitting diodes

Directory of Open Access Journals (Sweden)

Rugang Geng

2016-06-01

Full Text Available Organic spintronics is an emerging and potential platform for future electronics and display due to the intriguing properties of organic semiconductors (OSCs. For the past decade, studies have focused on three types of organic spintronic phenomena: (i magnetic field effect (MFE in organic light emitting diodes (OLEDs, where spin mixing between singlet and triplet polaron pairs (PP can be influenced by an external magnetic field leading to organic magnetoresistive effect (OMAR; (ii magnetoresistance (MR in organic spin valves (OSVs, where spin injection, transport, manipulation, and detection have been demonstrated; and (iii magnetoelectroluminescence (MEL bipolar OSVs or spin-OLEDs, where spin polarized electrons and holes are simultaneously injected into the OSC layer, leading to the dependence of electroluminescence intensity on relative magnetization of the electrodes. In this first of two review papers, we present major experimental results on OMAR studies and current understanding of OMAR using several spin dependent processes in organic semiconductors. During the discussion, we highlight some of the outstanding challenges in this promising research field. Finally, we provide an outlook on the future of organic spintronics.

Special Heusler compounds for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Balke, B.

2007-07-01

This work emphasizes the potential of Heusler compounds in a wide range of spintronic applications. Using electronic structure calculations it is possible to design compounds for specific applications. Examples for GMR and TMR applications, for spin injection into semiconductors, and for spin torque transfer applications will be shown. After a detailed introduction about spintronics and related materials chapter 5 reports about the investigation of new half-metallic compounds where the Fermi energy is tuned in the middle of the gap to result in more stable compounds for GMR and TMR applications. The bulk properties of the quaternary Heusler alloy Co{sub 2}Mn{sub 1-x}Fe{sub x}Si with the Fe concentration ranging from x=0 to 1 are reported and the results suggest that the best candidate for applications may be found at an iron concentration of about 50%. Due to the effect that in the Co{sub 2}Mn{sub 1-x}Fe{sub x}Si series the transition metal carrying the localized moment is exchanged and this might lead to unexpected effects on the magnetic properties if the samples are not completely homogeneous chapter 6 reports about the optimization of the Heusler compounds for GMR and TMR applications. The structural and magnetic properties of the quaternary Heusler alloy Co{sub 2}FeAl{sub 1-x}Si{sub x} with varying Si concentration are reported. From the combination of experimental (better order for high Si content) and theoretical findings (robust gap at x=0.5) it is concluded that a compound with an intermediate Si concentration close to x=0.5-0.7 would be best suited for spintronic applications, especially for GMR and TMR applications. In chapter 7 the detailed investigation of compounds for spin injection into semiconductors is reported. It is shown that the diluted magnetic semiconductors based on CoTiSb with a very low lattice mismatch among each other are interesting materials for spintronics applications like Spin-LEDs or other spin injection devices. Chapter 8 refers

ESPINTRÓNICA, LA ELECTRONICA DEL ESPÍN SPINTRONICS, SPIN ELECTRONICS

KAUST Repository

Monteblanco, Elmer

2017-03-14

Current technology seeks to develop nanoscale devices capable of storing and processing information. These devices would be difficult to make in the area of electronics, which is based on the manipulation of electric charge. However, thanks to advances in experimental and theoretical physics in the field of condensed matter, these devices are already a reality, belonging to the field of what we now call spintronics, which bases its functionality on the control of the electron’s spin, a property that can only be conceived at the quantum level. In this article we review this new perspective, describing giant- and tunneling- magnetoresistance, the spin transfer torque, and their applications such as MRAM memories, nano-oscillators and lateral spin valves.

ESPINTRÓNICA, LA ELECTRONICA DEL ESPÍN SPINTRONICS, SPIN ELECTRONICS

KAUST Repository

Monteblanco, Elmer; Ortiz Pauyac, Christian; Savero, Williams; RojasSanchez, J. Carlos; Schuhl, A.

2017-01-01

Current technology seeks to develop nanoscale devices capable of storing and processing information. These devices would be difficult to make in the area of electronics, which is based on the manipulation of electric charge. However, thanks to advances in experimental and theoretical physics in the field of condensed matter, these devices are already a reality, belonging to the field of what we now call spintronics, which bases its functionality on the control of the electron’s spin, a property that can only be conceived at the quantum level. In this article we review this new perspective, describing giant- and tunneling- magnetoresistance, the spin transfer torque, and their applications such as MRAM memories, nano-oscillators and lateral spin valves.

Spin-chemistry concepts for spintronics scientists

Directory of Open Access Journals (Sweden)

Konstantin L. Ivanov

2017-07-01

Full Text Available Spin chemistry and spintronics developed independently and with different terminology. Until now, the interaction between the two fields has been very limited. In this review, we compile the two “languages” in an effort to enhance communication. We expect that knowledge of spin chemistry will accelerate progress in spintronics.

Quantum computing and spintronics

International Nuclear Information System (INIS)

Kantser, V.

2007-01-01

Tentative to build a computer, which can operate according to the quantum laws, has leaded to concept of quantum computing algorithms and hardware. In this review we highlight recent developments which point the way to quantum computing on the basis solid state nanostructures after some general considerations concerning quantum information science and introducing a set of basic requirements for any quantum computer proposal. One of the major direction of research on the way to quantum computing is to exploit the spin (in addition to the orbital) degree of freedom of the electron, giving birth to the field of spintronics. We address some semiconductor approach based on spin orbit coupling in semiconductor nanostructures. (authors)

Antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Jungwirth, Tomáš; Martí, Xavier; Wadley, P.; Wunderlich, Joerg

2016-01-01

Roč. 11, č. 3 (2016), 231-241 ISSN 1748-3387 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : antiferromagnets * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 38.986, year: 2016

Large-scale fabrication of BN tunnel barriers for graphene spintronics

International Nuclear Information System (INIS)

Fu, Wangyang; Makk, Péter; Maurand, Romain; Bräuninger, Matthias; Schönenberger, Christian

2014-01-01

We have fabricated graphene spin-valve devices utilizing scalable materials made from chemical vapor deposition (CVD). Both the spin-transporting graphene and the tunnel barrier material are CVD-grown. The tunnel barrier is realized by Hexagonal boron nitride, used either as a monolayer or bilayer and placed over the graphene. Spin transport experiments were performed using ferromagnetic contacts deposited onto the barrier. We find that spin injection is still greatly suppressed in devices with a monolayer tunneling barrier due to resistance mismatch. This is, however, not the case for devices with bilayer barriers. For those devices, a spin relaxation time of ∼260 ps intrinsic to the CVD graphene material is deduced. This time scale is comparable to those reported for exfoliated graphene, suggesting that this CVD approach is promising for spintronic applications which require scalable materials

Materials for spintronic: Room temperature ferromagnetism in Zn-Mn-O interfaces

International Nuclear Information System (INIS)

Quesada, A.; Garcia, M.A.; Crespo, P.; Hernando, A.

2006-01-01

In this paper we study the room temperature ferromagnetism reported on Mn-doped ZnO and ascribed to spin polarization of conduction electrons. We experimentally show that the ferromagnetic behaviour is associated to the coexistence of Mn 3+ and Mn +4 in MnO 2 grains where diffusion of Zn promotes the Mn 4+→ Mn 3+ reduction. Potential uses of this material in spintronic devices are analysed

Spintronics and thermoelectrics in exfoliated and epitaxial graphene

NARCIS (Netherlands)

van den Berg, Jan Jasper

2016-01-01

This thesis is about two subjects: graphene spintronics and graphene thermoelectrics. Spintronics is about the creation and manipulation of spin currents. These are electrical currents in which we can control the spin orientation (up or down) of the conduction electrons. The second subject,

Synthesis and characterization of transition-metal-doped zinc oxide nanocrystals for spintronics

Science.gov (United States)

Wang, Xuefeng

Spintronics (spin transport electr onics), in which both spin and charge of carriers are utilized for information processing, is believed to challenge the current microelectronics and to become the next-generation electronics. Nanostructured spintronic materials and their synthetic methodologies are of paramount importance for manufacturing future nanoscale spintronic devices. This thesis aims at studying synthesis, characterization, and magnetism of transition-metal-doped zinc oxide (ZnO) nanocrystals---a diluted magnetic semiconductor (DMS)---for potential applications in future nano-spintronics. A simple bottom-up-based synthetic strategy named a solvothermal technique is introduced as the primary synthetic approach and its crystal growth mechanism is scrutinized. N-type cobalt-doped ZnO-based DMS nanocrystals are employed as a model system, and characterized by a broad spectrum of advanced microscopic and spectroscopic techniques. It is found that the self-orientation growth mechanism, imperfect oriented attachment, is intimately correlated with the high-temperature ferromagnetism via defects. The influence of processing on the magnetic properties, such as compositional variations, reaction conditions, and post-growth treatment, is also studied. In this way, an in-depth understanding of processing-structure-property interrelationships and origins of magnetism in DMS nanocrystals are obtained in light of the theoretical framework of a spin-split impurity band model. In addition, a nanoscale spinodal decomposition phase model is also briefly discussed. Following the similar synthetic route, copper- and manganese-doped ZnO nanocrystals have been synthesized and characterized. They both show high-temperature ferromagnetism in line with the aforementioned theoretical model(s). Moreover, they display interesting exchange biasing phenomena at low temperatures, revealing the complexity of magnetic phases therein. The crystal growth strategy demonstrated in this work

Flexible spintronic devices on Kapton

DEFF Research Database (Denmark)

Bedoya-Pinto, Amilcar; Donolato, Marco; Gobbi, Marco

2014-01-01

Magnetic tunnel junctions and nano-sized domain-wall conduits have been fabricated on the flexible substrate Kapton. Despite the delicate nature of tunneling barriers and zig-zag shaped nanowires, the devices show an outstanding integrity and robustness upon mechanical bending. High values of ben...

Ultrathin Epitaxial Ferromagneticγ-Fe2O3Layer as High Efficiency Spin Filtering Materials for Spintronics Device Based on Semiconductors

KAUST Repository

Li, Peng

2016-06-01

In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin-up and spin-down electrons, which has shown great promise for use in different ferromagnetic materials. However, the low spin-filtering efficiency in some materials can be ascribed partially to the difficulty in fabricating high-quality thin film with high Curie temperature and/or partially to the improper model used to extract the spin-filtering efficiency. In this work, a new technique is successfully developed to fabricate high quality, ferrimagnetic insulating γ-Fe2O3 films as spin filter. To extract the spin-filtering effect of γ-Fe2O3 films more accurately, a new model is proposed based on Fowler–Nordheim tunneling and Zeeman effect to obtain the spin polarization of the tunneling currents. Spin polarization of the tunneled current can be as high as −94.3% at 2 K in γ-Fe2O3 layer with 6.5 nm thick, and the spin polarization decays monotonically with temperature. Although the spin-filter effect is not very high at room temperature, this work demonstrates that spinel ferrites are very promising materials for spin injection into semiconductors at low temperature, which is important for development of novel spintronics devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin

2011-02-19

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Cr-doped III-V nitrides: Potential candidates for spintronics

KAUST Repository

Amin, Bin; Arif, Suneela K.; Ahmad, Iftikhar; Maqbool, Muhammad; Ahmad, Roshan; Goumri-Said, Souraya; Prisbrey, Keith A.

2011-01-01

Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

Theory of superconducting spintronic SIsFS devices

International Nuclear Information System (INIS)

Bakurskiy, S.V.; Klenov, N.V.; Soloviev, I.I.; Kupriyanov, M.Yu.; Bol'ginov, V.V.; Ryazanov, V.V.; Vernik, I.V.; Mukhanov, O.A.; Golubov, A.A.

2013-01-01

Full text: Motivated by recent progress in developments of cryogenic memory compatible with single flux quantum (SFQ) circuits we have performed a theoretical study of magnetic SIsFS Josephson junctions, where 'S' is a bulk superconductor, 's' is a thin superconducting film, 'F' is a metallic ferromagnet and 'I' is an insulator. We calculate the Josephson current as a function of s and F layers thickness, temperature and exchange energy of F film. We outline several modes of operation of these junctions and demonstrate their unique ability to have high I C R N product in the π-state, comparable to that in SIS tunnel junctions commonly used in SFQ circuits. We develop a model describing switching of the Josephson critical current in these devices by external magnetic field. The results are in good agreement with the experimental data for Nb-Al/AlOx-Nb-Pd0:99Fe0:01-Nb junctions. This work is supported by RFBR No. 12-02-90010-Bel a .

Prospects of asymmetrically H-terminated zigzag germanene nanoribbons for spintronic application

Energy Technology Data Exchange (ETDEWEB)

Sharma, Varun, E-mail: varun@iiitm.ac.in [Nanomaterials Research Group, ABV-Indian Institute of Information Technology and Management (IIITM), Gwalior 474015 (India); Srivastava, Pankaj [Nanomaterials Research Group, ABV-Indian Institute of Information Technology and Management (IIITM), Gwalior 474015 (India); Jaiswal, Neeraj K. [Discipline of Physics, Indian Institute of Information Technology, Design & Manufacturing, Jabalpur, Dumna Airport Road, Jabalpur 482005 (India)

2017-02-28

Highlights: • Asymmetric hydrogen termination of Zigzag Germanene Nanoribbons (ZGeNR) is presented with their plausible spintronic device application. • It is revealed that asymmetric terminations are energetically more favourable compared to symmetric terminations. • The magnetic moment analysis depicts that asymmetric ZGeNR have a magnetic ground state with a preferred ferromagnetic (FM) coupling. • Presented doped asymmetric ZGeNR exhibits a half-metallic character which makes them qualify for spin-filtering device. - Abstract: First-principles investigations have been performed to explore the spin based electronic and transport properties of asymmetrically H-terminated zigzag germanene nanoribbons (2H−H ZGeNR). Investigations reveal a significant formation energy difference (ΔE{sub F} = E{sub F(2H-H)} − E{sub F(H-H)} ∼ −0.49 eV), highlighting more energetic stability for asymmetric edge termination compared to symmetric edge termination, irrespective of the ribbon width. Further, magnetic moment analysis and total energy calculations were performed to unveil that these structures have a magnetic ground state with preferred ferromagnetic (FM) coupling. The calculated E-k structures project a unique bipolar semiconducting behaviour for 2H−H ZGeNR which is contrast to H-terminated ZGeNR. Half-metallic transformation has also been revealed via suitable p-type or n-type doping for these structures. Finally, transport calculations were performed to highlight the selective contributions of spin-down (spin-up) electrons in the I–V characteristics of the doped 2H−H ZGeNR, suggesting their vitality for spintronic device applications.

Ferromagnetism in doped or undoped spintronics nanomaterials

Science.gov (United States)

Qiang, You

2010-10-01

Much interest has been sparked by the discovery of ferromagnetism in a range of oxide doped and undoped semiconductors. The development of ferromagnetic oxide semiconductor materials with giant magnetoresistance (GMR) offers many advantages in spintronics devices for future miniaturization of computers. Among them, TM-doped ZnO is an extensively studied n-type wide-band-gap (3.36 eV) semiconductor with a tremendous interest as future mini-computer, blue light emitting, and solar cells. In this talk, Co-doped ZnO and Co-doped Cu2O semiconductor nanoclusters are successfully synthesized by a third generation sputtering-gas-aggregation cluster technique. The Co-doped nanoclusters are ferromagnetic with Curie temperature above room temperature. Both of Co-doped nanoclusters show positive magnetoresistance (PMR) at low temperature, but the amplitude of the PMRs shows an anomalous difference. For similar Co doping concentration at 5 K, PMR is greater than 800% for Co-doped ZnO but only 5% for Co-doped Cu2O nanoclusters. Giant PMR in Co-doped ZnO which is attributed to large Zeeman splitting effect has a linear dependence on applied magnetic field with very high sensitivity, which makes it convenient for the future spintronics applications. The small PMR in Co-doped Cu2O is related to its vanishing density of states at Fermi level. Undoped Zn/ZnO core-shell nanoparticle gives high ferromagnetic properties above room temperature due to the defect induced magnetization at the interface.

Surface spintronics enhanced photo-catalytic hydrogen evolution: Mechanisms, strategies, challenges and future

Science.gov (United States)

Zhang, Wenyan; Gao, Wei; Zhang, Xuqiang; Li, Zhen; Lu, Gongxuan

2018-03-01

Hydrogen is a green energy carrier with high enthalpy and zero environmental pollution emission characteristics. Photocatalytic hydrogen evolution (HER) is a sustainable and promising way to generate hydrogen. Despite of great achievements in photocatalytic HER research, its efficiency is still limited due to undesirable electron transfer loss, high HER over-potential and low stability of some photocatalysts, which lead to their unsatisfied performance in HER and anti-photocorrosion properties. In recent years, many spintronics works have shown their enhancing effects on photo-catalytic HER. For example, it was reported that spin polarized photo-electrons could result in higher photocurrents and HER turn-over frequency (up to 200%) in photocatalytic system. Two strategies have been developed for electron spin polarizing, which resort to heavy atom effect and magnetic induction respectively. Both theoretical and experimental studies show that controlling spin state of OHrad radicals in photocatalytic reaction can not only decrease OER over-potential (even to 0 eV) of water splitting, but improve stability and charge lifetime of photocatalysts. A convenient strategy have been developed for aligning spin state of OHrad by utilizing chiral molecules to spin filter photo-electrons. By chiral-induced spin filtering, electron polarization can approach to 74%, which is significantly larger than some traditional transition metal devices. Those achievements demonstrate bright future of spintronics in enhancing photocatalytic HER, nevertheless, there is little work systematically reviewing and analysis this topic. This review focuses on recent achievements of spintronics in photocatalytic HER study, and systematically summarizes the related mechanisms and important strategies proposed. Besides, the challenges and developing trends of spintronics enhanced photo-catalytic HER research are discussed, expecting to comprehend and explore such interdisciplinary research in

Operation training aid device

International Nuclear Information System (INIS)

Yoshimura, Sadanori.

1994-01-01

The device of the present invention evaluates the propriety of an operation which is conducted optionally by a trainee depending on the state of the plant, analyzes the cause of an operation error and aids the preparation of training policy and teaching materials based on the results of the evaluation and the analysis. Namely, an operation data collection device collects operation data for the plant operation conducted by the trainee and the state of the plant during the operation. Since an operation evaluation device evaluates the plant operation in a short period of time based on the evaluation criteria of an operation evaluation knowledge base, an operation error is never overlooked. Accordingly, uniform and highly reliable operation training at definite evaluation criteria can be obtained. In addition, an error-cause analyzing device and a training policy knowledge base analyze the cause of an error inherent to each of the trainee, and it is recorded systematically independently on every trainees. Since a training policy guide device retrieves and presents an operation error and a cause of the error, there can be prepared a training policy incorporating training with respect to the operation error that each of the trainee tends to commit. (I.S.)

Spintronic microfluidic platform for biomedical and environmental applications

Science.gov (United States)

Cardoso, F. A.; Martins, V. C.; Fonseca, L. P.; Germano, J.; Sousa, L. A.; Piedade, M. S.; Freitas, P. P.

2010-09-01

Faster, more sensitive and easy to operate biosensing devices still are a need at important areas such as biomedical diagnostics, food control and environmental monitoring. Recently, spintronic-devices have emerged as a promising alternative to the existent technologies [1-3]. A number of advantages, namely high sensitivity, easy integration, miniaturization, scalability, robustness and low cost make these devices potentially capable of responding to the existent technological need. In parallel, the field of microfluidics has shown great advances [4]. Microfluidic systems allow the analysis of small sample volumes (from micro- down to pico-liters), often by automate sample processing with the ability to integrate several steps into a single device (analyte amplification, concentration, separation and/or labeling), all in a reduced assay time (minutes to hours) and affordable cost. The merging of these two technologies, magnetoresistive biochips and microfluidics, will enable the development of highly competitive devices. This work reports the integration of a magnetoresistive biochip with a microfluidic system inside a portable and autonomous electronic platform aiming for a fully integrated device. A microfluidic structure fabricated in polydimethylsiloxane with dimensions of W: 0.5mm, H: 0.1mm, L: 10mm, associated to a mechanical system to align and seal the channel by pressure is presented (Fig. 1) [5]. The goal is to perform sample loading and transportation over the chip and simultaneously control the stringency and uniformity of the wash-out process. The biochip output is acquired by an electronic microsystem incorporating the circuitry to control, address and read-out the 30 spin-valve sensors sequentially (Fig. 1) [2]. This platform is being applied to the detection of water-borne microbial pathogens (e.g. Salmonella and Escherichia coli) and genetic diseases diagnosis (e.g. cystic fibrosis) through DNA hybridization assays. Open chamber measurements were

Spintronics of antiferromagnetic systems

International Nuclear Information System (INIS)

Gomonaj, E.V.; Loktev, V.M.

2014-01-01

Spintronics of antiferromagnetics is a new field that has developed in a fascinating research topic in physics of magnetism. Antiferromagnetics, like ferromagnetic materials experience the influence of spin-polarized current, even though they show no macroscopic magnetization. The mechanism of this phenomenon is related to spin-dependent interaction between free and localized electrons-sd-exchange. Due to the peculiarities of antiferromagnetic materials (complicated magnetic structure, essential role of the exchange interactions, lack of macroscopic magnetization) spintronics of antiferromagnets appeals to new theoretical and experimental approaches. The purpose of this review is to systemize and summarize the recent progress in this field. We start with a short introduction into the structure and dynamics of antiferromagnets and proceed with discussion of different microscopic and phenomenological theories for description of current-induced phenomena in ferro-/antiferromagnetic heterostructures. We also consider the problems of the reverse influence of antiferromagnetic ordering on current, and effectiveness of the fully antiferromagnetic spin valve. In addition, we shortly review and interpret the available experimental results.

Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

Energy Technology Data Exchange (ETDEWEB)

Tomasello, R. [Department of Computer Science, Modeling, Electronics and System Science, University of Calabria, Rende (CS) (Italy); Carpentieri, M., E-mail: m.carpentieri@poliba.it [Department of Electrical and Information Engineering, Politecnico of Bari, via E. Orabona 4, I-70125 Bari (Italy); Finocchio, G. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy)

2013-12-16

This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed.

Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

International Nuclear Information System (INIS)

Tomasello, R.; Carpentieri, M.; Finocchio, G.

2013-01-01

This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed

Electric field-induced magnetoresistance in spin-valve/piezoelectric multiferroic laminates for low-power spintronics

International Nuclear Information System (INIS)

Huong Giang, D.T.; Thuc, V.N.; Duc, N.H.

2012-01-01

Electric field-induced magnetic anisotropy has been realized in the spin-valve-based {Ni 80 Fe 20 /Cu/Fe 50 Co 50 /IrMn}/piezoelectric multiferroic laminates. In this system, electric-field control of magnetization is accomplished by strain mediated magnetoelectric coupling. Practically, the magnetization in the magnetostrictive FeCo layer of the spin-valve structure rotates under an effective compressive stress caused by the inverse piezoelectric effect in external electrical fields. This phenomenon is evidenced by the magnetization and magnetoresistance changes under the electrical field applied across the piezoelectric layer. The result shows great potential for advanced low-power spintronic devices. - Highlights: ► Investigate electric field-induced magnetic anisotropy in spin-valve/piezoelectric. ► Magnetization, magnetoresistance changes under electric field across piezoelectric. ► Magnetization in magnetostrictive FeCo-layer rotates under a compressive stress. ► This advance shows great implications for low-power electronics and spintronics.

Prospect for antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Martí, Xavier; Fina, I.; Jungwirth, Tomáš

2015-01-01

Roč. 51, č. 4 (2015), s. 2900104 ISSN 0018-9464 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : spintronics * antiferromagnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.277, year: 2015

Operation control device under radiation exposure

International Nuclear Information System (INIS)

Kimura, Kiichi; Murakami, Toichi.

1994-01-01

The device of the present invention performs smooth progress of operation by remote control for a plurality of operations in periodical inspections in controlled areas of a nuclear power plant, thereby reducing the operator's exposure dose. Namely, the device monitors the progressing state of the operation by displaying the progress of operation on a CRT of a centralized control device present in a low dose area remote from an operation field through an ITV camera disposed in the vicinity of the operation field. Further, operation sequence and operation instruction procedures previously inputted in the device are indicated to the operation field through an operation instruction outputting device (field CRT) in accordance with the progress of the operation steps. On the other hand, the operation progress can be aided by inputting information from the operation field such as start or completion of the operation steps. Further, the device of the present invention can monitor the change of operation circumstances and exposure dose of operators based on the information from a radiation dose measuring device disposed in the operation circumstance and to individual operators. (I.S.)

Magnetization Dynamics in Two Novel Current-Driven Spintronic Memory Cell Structures

KAUST Repository

Velazquez-Rizo, Martin

2017-07-01

In this work, two new spintronic memory cell structures are proposed. The first cell uses the diffusion of polarized spins into ferromagnets with perpendicular anisotropy to tilt their magnetization followed by their dipolar coupling to a fixed magnet (Bhowmik et al., 2014). The possibility of setting the magnetization to both stable magnetization states in a controlled manner using a similar concept remains unknown, but the proposed structure poses to be a solution to this difficulty. The second cell proposed takes advantage of the multiple stable magnetic states that exist in ferromagnets with configurational anisotropy and also uses spin torques to manipulate its magnetization. It utilizes a square-shaped ferromagnet whose stable magnetization has preferred directions along the diagonals of the square, giving four stable magnetic states allowing to use the structure as a multi-bit memory cell. Both devices use spin currents generated in heavy metals by the Spin Hall effect present in these materials. Among the advantages of the structures proposed are their inherent non-volatility and the fact that there is no need for applying external magnetic fields during their operation, which drastically improves the energy efficiency of the devices. Computational simulations using the Object Oriented Micromagnetic Framework (OOMMF) software package were performed to study the dynamics of the magnetization process in both structures and predict their behavior. Besides, we fabricated a 4-terminal memory cell with configurational anisotropy similar to the device proposed, and found four stable resistive states on the structure, proving the feasibility of this technology for implementation of high-density, non-volatile memory cells.

The importance of Fe interface states for ferromagnet-semiconductor based spintronic devices

Science.gov (United States)

Chantis, Athanasios

2009-03-01

I present our recent theoretical studies of the bias-controlled spin injection, detection sensitivity and tunneling anisotropic magnetoresistance in ferromagnetic-semiconductor tunnel junctions. Using first-principles electron transport methods we have shown that Fe 3d minority-spin surface (interface) states are responsible for at least two important effects for spin electronics. First, they can produce a sizable Tunneling Anisotropic Magnetoresistance in magnetic tunnel junctions with a single Fe electrode. The effect is driven by a Rashba shift of the resonant surface band when the magnetization changes direction. This can introduce a new class of spintronic devices, namely, Tunneling Magnetoresistance junctions with a single ferromagnetic electrode that can function at room temperatures. Second, in Fe/GaAs(001) magnetic tunnel junctions they produce a strong dependence of the tunneling current spin-polarization on applied electrical bias. A dramatic sign reversal within a voltage range of just a few tenths of an eV is found. This explains the observed sign reversal of spin-polarization in recent experiments of electrical spin injection in Fe/GaAs(001) and related reversal of tunneling magnetoresistcance through vertical Fe/GaAs/Fe trilayers. We also present a theoretical description of electrical spin-detection at a ferromagnet/semiconductor interface. We show that the sensitivity of the spin detector has strong bias dependence which, in the general case, is dramatically different from that of the tunneling current spin-polarization. We show that in realistic ferromagnet/semiconductor junctions this bias dependence can originate from two distinct physical mechanisms: 1) the bias dependence of tunneling current spin-polarization, which is of microscopic origin and depends on the specific properties of the interface, and 2) the macroscopic electron spin transport properties in the semiconductor. Our numerical results show that the magnitude of the voltage signal

Operation planning device

International Nuclear Information System (INIS)

Watanabe, Takashi; Odakawa, Naoto; Erikuchi, Makoto; Okada, Masayuki; Koizumi, Atsuhiko.

1996-01-01

The device of the present invention provides a device suitable for monitoring a reactor core state and operation replanning in terms of reactor operation. Namely, (1) an operation result difference judging means judges that replanning is necessary when the operation results deviates from the operation planning, (2) an operation replanning rule data base storing means stores a deviation key which shows various kinds of states where the results deviate from the planning and a rule for replanning for returning to the operation planning on every deviating key, (3) an operation replanning means forms a new operation planning in accordance with the rule which is retrieved based on the deviation key, (4) an operation planning optimizing rule data base storing means evaluates the reformed planning and stores it on every evaluation item, (5) an operation planning optimization means correct the operation planning data so as to be optimized when the evaluation of the means (4) is less than a reference value, and (6) an operation planning display means edits adaptable operation planning data and the result of the evaluation and displays them. (I.S.)

Concepts of antiferromagnetic spintronics

Czech Academy of Sciences Publication Activity Database

Gomonay, O.; Jungwirth, Tomáš; Sinova, Jairo

2017-01-01

Roč. 11, č. 4 (2017), 1-8, č. článku 1700022. ISSN 1862-6254 R&D Projects: GA MŠk LM2015087; GA ČR GB14-37427G Institutional support: RVO:68378271 Keywords : spintronics * antiferromagnets Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.032, year: 2016

Preparation and characterization of highly L21-ordered full-Heusler alloy Co2FeAl0.5Si0.5 thin films for spintronics device applications

International Nuclear Information System (INIS)

Wang Wenhong; Sukegawa, Hiroaki; Shan Rong; Furubayashi, Takao; Inomata, Koichiro

2008-01-01

We report the investigation of structure and magnetic properties of full-Heusler alloy Co 2 FeAl 0.5 Si 0.5 (CFAS) thin films grown on MgO-buffered MgO (001) substrates through magnetron sputtering. It was found that single-crystal CFAS thin films with high degree of L2 1 ordering and sufficiently flat surface could be obtained after postdeposition annealing. All the films show a distinct uniaxial magnetic anisotropy with the easy axis of magnetization along the in-plane [110] direction. These results indicate that the use of the MgO buffer for CFAS is a promising approach for achieving a higher tunnel magnetoresistance ratio, and thus for spintronics device applications

Ultrathin Epitaxial Ferromagneticγ-Fe2O3Layer as High Efficiency Spin Filtering Materials for Spintronics Device Based on Semiconductors

KAUST Repository

Li, Peng; Xia, Chuan; Zhu, Zhiyong; Wen, Yan; Zhang, Qiang; Alshareef, Husam N.; Zhang, Xixiang

2016-01-01

In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin

Graphene-based spintronic components

OpenAIRE

Zeng, Minggang; Shen, Lei; Su, Haibin; Zhou, Miao; Zhang, Chun; Feng, Yuanping

2010-01-01

A major challenge of spintronics is in generating, controlling and detecting spin-polarized current. Manipulation of spin-polarized current, in particular, is difficult. We demonstrate here, based on calculated transport properties of graphene nanoribbons, that nearly +-100% spin-polarized current can be generated in zigzag graphene nanoribbons (ZGNRs) and tuned by a source-drain voltage in the bipolar spin diode, in addition to magnetic configurations of the electrodes. This unusual transpor...

On the path toward organic spintronics

NARCIS (Netherlands)

Moodera, J.S.; Koopmans, B.; Oppeneer, P.M.

2014-01-01

Organic materials provide a unique platform for exploiting the spin of the electron—a field dubbed organic spintronics. Originally, this was mostly motivated by the notion that because of weak spin-orbit coupling, due to the small mass elements in organics and small hyperfine field coupling, organic

Multi-parameter geometrical scaledown study for energy optimization of MTJ and related spintronics nanodevices

Science.gov (United States)

Farhat, I. A. H.; Alpha, C.; Gale, E.; Atia, D. Y.; Stein, A.; Isakovic, A. F.

The scaledown of magnetic tunnel junctions (MTJ) and related nanoscale spintronics devices poses unique challenges for energy optimization of their performance. We demonstrate the dependence of the switching current on the scaledown variable, while considering the influence of geometric parameters of MTJ, such as the free layer thickness, tfree, lateral size of the MTJ, w, and the anisotropy parameter of the MTJ. At the same time, we point out which values of the saturation magnetization, Ms, and anisotropy field, Hk, can lead to lowering the switching current and overall decrease of the energy needed to operate an MTJ. It is demonstrated that scaledown via decreasing the lateral size of the MTJ, while allowing some other parameters to be unconstrained, can improve energy performance by a measurable factor, shown to be the function of both geometric and physical parameters above. Given the complex interdependencies among both families of parameters, we developed a particle swarm optimization (PSO) algorithm that can simultaneously lower energy of operation and the switching current density. Results we obtained in scaledown study and via PSO optimization are compared to experimental results. Support by Mubadala-SRC 2012-VJ-2335 is acknowledged, as are staff at Cornell-CNF and BNL-CFN.

LSMO - growing opportunities by PLD and applications in spintronics

Energy Technology Data Exchange (ETDEWEB)

Cesaria, M; Caricato, A P; Maruccio, G; Martino, M, E-mail: maura.cesaria@le.infn.it [Physics Department, University of Salento, Via Arnesano, 73100, Lecce (Italy)

2011-04-01

Ferromagnetic materials exhibiting at room temperature combination of good conductivity, magnetic and opto-electronic properties are needed for the development of functional spin-devices. Mixed-valence LSMO is an optimal source of fully spin-polarized carriers and shows a rich physics of magnetic phases and transport mechanisms. Many factors, such as growth temperature, oxygen stoichiometry, temperature-dependent oxygen desorption rate, structural matching between the growing film and substrate, film thickness, and defects, influence the LSMO properties. Stabilization of ferromagnetic and conductive behaviours is linked to structural order. Therefore a growth approach allowing congruent deposition of complex materials under controlled, reproducible and tunable conditions is strongly needed. In this respect pulsed laser deposition reveals a well-suited choice. This review aims to give an overview on LSMO thin film properties, deposition and applications, especially in the emerging organic spintronics.

From Spintronics to CFD/ContractForDifferences

Science.gov (United States)

Maksoed, W. H.

2015-11-01

Involve the CFD/Computational Fluid Dynamics & HCCI/Homogeneous Charge Compression Ignition - Marcine Frackowiak, dissertation, 2009, for CFD/Contract For Differences accompanied by ``One Man's Crusade to Exonerate Hydrogen for Hindenburg Disaster'' of Addison BAIN, APS News, v. 9, n.7 (July 2000) concludes ``ignition of the blaze'' are responsible to those May, 1937 Accidents. Spintronics their selves include active control & manipulation of spin degree of freedom ever denotes: the nano-obelisk of scanning electron microscopy of galliumnitride/GaN nanostructures-Yong-Hon Cho et al.:``Novel Photonic Device using core-shell nanostructures'', SPIE-newsroom,10.1117/2.1201503.005864. Herewith commercial activated carbon/C can be imaged directly using abberation-corrected transmission electron microscopy[PJF Harris et al.: ``Imaging the Atomic Structures of activated C'', J. Phys. Condens. Matt, 20 (2008) in fig b & c- images networks of hexagonal rings can be clearly be seen depicts equal etchings of 340 px Akhenaten, Nefertiti & their childrens. Incredible acknowledgments to Minister of Education & Culture RI 1998-1999 HE. Mr. Prof. Ir. WIRANTO ARISMUNANDAR, MSME.

Nanospintronics: when spintronics meets single electron physics

International Nuclear Information System (INIS)

Seneor, Pierre; Bernand-Mantel, Anne; Petroff, Frederic

2007-01-01

As spintronics goes nano, new phenomena are predicted resulting from the interplay between spin dependent transport and single electron physics. The long term goal of manipulating spins one by one would open a promising path to quantum computing. Towards this end, there is an ever-growing effort to connect spin tanks (i.e. ferromagnetic leads) to smaller and smaller objects in order to study spintronics in reduced dimensions. As the dimensions are reduced, spin dependent transport is predicted to interplay with quantum and/or single electron charging effects. We review experiments and theories on the interplay between Coulomb blockade and spin properties (namely magneto-Coulomb effects) in structures where a single nano-object is connected to ferromagnetic leads. We then discuss briefly future directions in the emerging field of nanospintronics towards quantum dots, carbon nanotubes and single molecule magnets

Comment on The Rise of Semiconductor Spintronics

OpenAIRE

Korenev, Vladimir L.

2009-01-01

I argue that most of the key experiments that have born semiconductor spintronics were done and published earlier than the papers cited in the Nature Physics, 4 S20 (2008) milestone article (http://www.nature.com/milestones/spin, milestone 23).

Effect of external magnetic field on locking range of spintronic feedback nano oscillator

Science.gov (United States)

Singh, Hanuman; Konishi, K.; Bose, A.; Bhuktare, S.; Miwa, S.; Fukushima, A.; Yakushiji, K.; Yuasa, S.; Kubota, H.; Suzuki, Y.; Tulapurkar, A. A.

2018-05-01

In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3) multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.

The first radical-based spintronic memristors: Towards resistive RAMs made of organic magnets

Science.gov (United States)

Goss, Karin; Krist, Florian; Seyfferle, Simon; Hoefel, Udo; Paretzki, Alexa; Dressel, Martin; Bogani, Lapo; Institut Fuer Anorganische Chemie, University of Stuttgart Collaboration; 1. Physikalisches Institut, University of Stuttgart Team

2014-03-01

Using molecules as building blocks for electronic devices offers ample possibilities for new device functionalities due to a chemical tunability much higher than that of standard inorganic materials, and at the same time offers a decrease in the size of the electronic component down to the single-molecule level. Purely organic molecules containing no metallic centers such as organic radicals can serve as an electronic component with magnetic properties due to the unpaired electron in the radical state. Here we present memristive logic units based on organic radicals of the nitronyl-nitroxide kind. Integrating these purely molecular units as a spin coated layer into crossbar arrays, electrically induced unipolar resistive switching is observed with a change in resistance of up to 100%. We introduce a model based on filamentary reorganization of molecules of different oxidation state revealing the importance of the molecular nature for the switching properties. The major role of the oxidation state of these paramagnetic molecules introduces a magnetic field dependence to the device functionality, which goes along with magnetoresistive charactistics observed for the material. These are the first steps towards a spintronic implementation of organic radicals in electronic devices.

Automatic operation device for control rods

International Nuclear Information System (INIS)

Sekimizu, Koichi

1984-01-01

Purpose: To enable automatic operation of control rods based on the reactor operation planning, and particularly, to decrease the operator's load upon start up and shutdown of the reactor. Constitution: Operation plannings, demand for the automatic operation, break point setting value, power and reactor core flow rate change, demand for operation interrupt, demand for restart, demand for forecasting and the like are inputted to an input device, and an overall judging device performs a long-term forecast as far as the break point by a long-term forecasting device based on the operation plannings. The automatic reactor operation or the like is carried out based on the long-term forecasting and the short time forecasting is performed by the change in the reactor core status due to the control rod operation sequence based on the control rod pattern and the operation planning. Then, it is judged if the operation for the intended control rod is possible or not based on the result of the short time forecasting. (Aizawa, K.)

Effect of external magnetic field on locking range of spintronic feedback nano oscillator

Directory of Open Access Journals (Sweden)

Hanuman Singh

2018-05-01

Full Text Available In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3 multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.

Molecular engineering with artificial atoms: designing a material platform for scalable quantum spintronics and photonics

Science.gov (United States)

Doty, Matthew F.; Ma, Xiangyu; Zide, Joshua M. O.; Bryant, Garnett W.

2017-09-01

Self-assembled InAs Quantum Dots (QDs) are often called "artificial atoms" and have long been of interest as components of quantum photonic and spintronic devices. Although there has been substantial progress in demonstrating optical control of both single spins confined to a single QD and entanglement between two separated QDs, the path toward scalable quantum photonic devices based on spins remains challenging. Quantum Dot Molecules, which consist of two closely-spaced InAs QDs, have unique properties that can be engineered with the solid state analog of molecular engineering in which the composition, size, and location of both the QDs and the intervening barrier are controlled during growth. Moreover, applied electric, magnetic, and optical fields can be used to modulate, in situ, both the spin and optical properties of the molecular states. We describe how the unique photonic properties of engineered Quantum Dot Molecules can be leveraged to overcome long-standing challenges to the creation of scalable quantum devices that manipulate single spins via photonics.

Spin-dependent transport and functional design in organic ferromagnetic devices

Directory of Open Access Journals (Sweden)

Guichao Hu

2017-09-01

Full Text Available Organic ferromagnets are intriguing materials in that they combine ferromagnetic and organic properties. Although challenges in their synthesis still remain, the development of organic spintronics has triggered strong interest in high-performance organic ferromagnetic devices. This review first introduces our theory for spin-dependent electron transport through organic ferromagnetic devices, which combines an extended Su–Schrieffer–Heeger model with the Green’s function method. The effects of the intrinsic interactions in the organic ferromagnets, including strong electron–lattice interaction and spin–spin correlation between π-electrons and radicals, are highlighted. Several interesting functional designs of organic ferromagnetic devices are discussed, specifically the concepts of a spin filter, multi-state magnetoresistance, and spin-current rectification. The mechanism of each phenomenon is explained by transmission and orbital analysis. These works show that organic ferromagnets are promising components for spintronic devices that deserve to be designed and examined in future experiments.

ELOPTA: a novel microcontroller-based operant device.

Science.gov (United States)

Hoffman, Adam M; Song, Jianjian; Tuttle, Elaina M

2007-11-01

Operant devices have been used for many years in animal behavior research, yet such devices a regenerally highly specialized and quite expensive. Although commercial models are somewhat adaptable and resilient, they are also extremely expensive and are controlled by difficult to learn proprietary software. As an alternative to commercial devices, we have designed and produced a fully functional, programmable operant device, using a PICmicro microcontroller (Microchip Technology, Inc.). The electronic operant testing apparatus (ELOPTA) is designed to deliver food when a study animal, in this case a bird, successfully depresses the correct sequence of illuminated keys. The device logs each keypress and can detect and log whenever a test animal i spositioned at the device. Data can be easily transferred to a computer and imported into any statistical analysis software. At about 3% the cost of a commercial device, ELOPTA will advance behavioral sciences, including behavioral ecology, animal learning and cognition, and ethology.

Plant operation monitoring method and device therefor

International Nuclear Information System (INIS)

Ando, Tsugio; Matsuki, Tsutomu.

1997-01-01

The present invention provides a method of and a device for monitoring the operation of a nuclear power plant during operation, which improves the safety and reliability of operation without increasing an operator's burden. Namely, a chief in charge orally instruct an operation to an operator upon the operation of a plant constituent equipment. The operator points the equipment and calls the name. Actual operation instruction for the equipment is inputted after confirmation by oral response. The voices of theses series of operation instruction/point-calling/response confirmation are taken into a voice recognition processing device. The processing device discriminates each of the person who calls, and discriminates the content of the calls and objective equipments to be operated. Then, the series of procedures and contents of the operation for the equipments previously disposed in the data base are compared with the order of inputted calls, discriminated contents and the objective equipments to be operated. If they are not agreed with each other, the operation instruction is blocked even if actual operation instructions are inputted. (I.S.)

Quest for high-Curie temperature MnxGe1-x diluted magnetic semiconductors for room-temperature spintronics applications

Science.gov (United States)

Nie, Tianxiao; Tang, Jianshi; Wang, Kang L.

2015-09-01

In this paper, we report the non-equilibrium growth of various Mn-doped Ge dilute magnetic semiconductor nanostructures using molecular-beam epitaxy, including quantum dots, nanodisks and nanowires. Their detailed structural and magnetic properties are characterized. By comparing the results with those in MnxGe1-x thin films, it is affirmed that the use of nanostructures helps eliminate crystalline defects and meanwhile enhance the carrier-mediate ferromagnetism from substantial quantum confinements. Our systematic studies provide a promising platform to build nonvolatile spinFET and other novel spintronic devices based upon dilute magnetic semiconductor nanostructures.

Reactor operation plan preparing device

International Nuclear Information System (INIS)

Sano, Hiroki; Maruyama, Hiromi; Kinoshita, Mitsuo; Fukuzaki, Koji; Banto, Masaru; Fukazawa, Yukihisa.

1993-01-01

The device comprises a means for retrieving a control rod pattern capable of satisfying a thermal limit upon aimed power/minimum flow rate and providing minimum xenon and a control rod pattern maximum xenon. It further comprises a means for selecting a control rod pattern corresponding to a xenon equilibrium condition, and selecting a control rod which provides a greater thermal margin to provide a control rod operation sequence for each of the patterns. Further, the device comprises an outline plan preparing means and a correction means therefor, a simplified sequence table reference means operated along with sequence change, an operation limit region input means, a control rod operation preferential region changing means, a thermal margin evaluation region and an input means. This can automatically prepare the operation plan, decrease the times for preparation of detailed plans by using the outline plan preparing function, thereby enabling to remarkably shorten the time for preparing of an operation plan. (N.H.)

Group IV all-semiconductor spintronics. Materials aspects and optical spin selection rules

Energy Technology Data Exchange (ETDEWEB)

Sircar, Narayan

2012-04-03

In the scope of the present thesis various aspects for the realization of spintronic applications based on group IV semiconductors are discussed. This work comprises a refined material characterization of the magnetic semiconductor GeMn. We furthermore present efforts to utilize this material as spin injector for a Si-based optical spintronic device. Applying transmission electron microscopy and atom probe tomography, we are able to resolve a vertical anisotropy in the self-assembly, leading to the stacking of well-defined clusters in the growth direction. Three-dimensional atom distribution maps confirm that clusters are built from a nonstoichiometric GeMn alloy and exhibit a high-Mn-concentration core with a decreasing Mn concentration toward a shell. An amorphous nature of the cluster cores as well as the crystallinity of the shells, coherent with the surrounding Ge lattice, are revealed in scanning transmission electron microscopy. We localize a strain field surrounding each GeMn cluster by scanning transmission electron microscopy. The importance of strain to the stacking phenomenon of the clusters becomes clear in studies of Ge/GeMn superlattice structures, where a vertical spatial correlation of clusters over 30 nm-thick Ge spacer layers is observed. We present evidence that electrical transport properties of the p-type GeMn thin films fabricated on high-resistivity Ge substrates are severely influenced by parallel conduction through the substrate. It is shown that substrate conduction persists also for wellconducting degenerate p-type reference thin films, giving rise to an effective two-layer conduction scheme. GeMn thin films fabricated on these substrates exhibit only a negligible magnetoresistance effect. Before integrating GeMn in an optical spintronic device, some key aspects important for an understanding of the optical injection and detection of carrier spins in Si and Si-based heterostructures are clarified in the second part of this thesis. In

Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures

International Nuclear Information System (INIS)

Kamalakar, M. Venkata; Dankert, André; Bergsten, Johan; Ive, Tommy; Dash, Saroj P.

2014-01-01

Hexagonal boron nitride (h-BN) is a large bandgap insulating isomorph of graphene, ideal for atomically thin tunnel barrier applications. In this letter, we demonstrate large area chemical vapor deposited (CVD) h-BN as a promising spin tunnel barrier in graphene spin transport devices. In such structures, the ferromagnetic tunnel contacts with h-BN barrier are found to show robust tunneling characteristics over a large scale with resistances in the favorable range for efficient spin injection into graphene. The non-local spin transport and precession experiments reveal spin lifetime ≈500 ps and spin diffusion length ≈1.6 μm in graphene with tunnel spin polarization ≈11% at 100 K. The electrical and spin transport measurements at different injection bias current and gate voltages confirm tunnel spin injection through h-BN barrier. These results open up possibilities for implementation of large area CVD h-BN in spintronic technologies

Spin-Valve Effect in a Ni-C60-Ni Device

National Research Council Canada - National Science Library

He, Haiying; Pandey, Ravindra; Karna, Shashi P

2006-01-01

.... The magnitude of the junction magnetoresistance (JMR) is found to be significantly large for the device, which makes it a promising candidate for realistic applications in molecular spintronics...

Spintronics with metals: Current perpendicular-to-the-plane magneto-transport studies

Science.gov (United States)

Sharma, Amit

In this thesis, we present studies to produce new information about three topics: current perpendicular to the plane magnetoresistance (CPP-MR), spin transfer torque (STT), and antiferromagnetic spintronics. Large values of CPP-MR interface parameters---specific interface resistance (Area times resistance), 2AR*, and scattering asymmetry, gamma---are desirable for the use of CPP-MR in devices. Stimulated by a nanopillar study by the Cornell Group, we first discovered that Py/Al had an unusually large 2AR*, but a small gamma. In the hope of finding metal pairs with large values of both the interface parameters, the Py/Al studies led us to study the following interfaces: (a) F/Al with F: Py (= Ni84Fe16). Co, Fe, Co91Fe9, and (b) F/N: Py/Pd, Fe/V, Fe/Nb and Co/Pt. None of the metal pairs looks better for CPP-MR devices. The Cornell group also found that bracketing Al with thin Cu in Py/Al/Py nanopillars, gave an MR similar to Py/Al/Py rather than to Py/Cu/Py. To try to understand this result, we studied the effect of Cu/Al/Cu spacers on ADeltaR = AR(AP) - AR(P) of Py exchange biased spin valves (EBSVs). Here AR(AP) and AR(P) are the specific resistances in the anti-parallel (AP) and parallel (P) configurations of the F layers. Intriguingly, fixing the Al thickness tAl = 10 nm and varying tCu has no effect on ADeltaR, but fixing tCu = 10 nm and varying t Al significantly affected ADeltaR. These unusual behaviors are probably due to strong Al and Cu intermixing, with probable formation of some fraction of ordered alloys. Recent calculations predicted that 2AR of Al/Ag interfaces would vary substantially with orientation and with alloying. The latter is a special potential problem, because Al and Ag interdiffuse at room temperature. To compare with the calculations, we determined 2AR of sputtered Al/Ag interfaces with (111) orientation. Our estimate agrees with calculations that assume 4 monolayers of interfacial disorder, consistent with modest intermixing. To aid in

Equiatomic quaternary Heusler alloys: A material perspective for spintronic applications

Energy Technology Data Exchange (ETDEWEB)

Bainsla, Lakhan, E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in; Suresh, K. G., E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in [Magnetic Materials Lab, Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India)

2016-09-15

Half-metallic ferromagnetic (HMF) materials show high spin polarization and are therefore interesting to researchers due to their possible applications in spintronic devices. In these materials, while one spin sub band has a finite density of states at the Fermi level, the other sub band has a gap. Because of their high Curie temperature (T{sub C}) and tunable electronic structure, HMF Heusler alloys have a special importance among the HMF materials. Full Heusler alloys with the stoichiometric composition X{sub 2}YZ (where X and Y are the transition metals and Z is a sp element) have the cubic L2{sub 1} structure with four interpenetrating fcc sublattices. When each of these four fcc sublattices is occupied by different atoms (XX′YZ), a quaternary Heusler structure with different structural symmetries (space group F-43m, #216) is obtained. Recently, these equiatomic quaternary Heusler alloys (EQHAs) with 1:1:1:1 stoichiometry have attracted a lot of attention due to their superior magnetic and transport properties. A special class of HMF materials identified recently is known as spin gapless semiconductors (SGS). The difference in this case, compared with HMFs, is that the density of states for one spin band is just zero at the Fermi level, while the other has a gap as in the case of HMFs. Some of the reported SGS materials belong to EQHAs family. This review is dedicated to almost all reported materials belonging to EQHAs family. The electronic structure and hence the physical properties of Heusler alloys strongly depend on the degree of structural order and distribution of the atoms in the crystal lattice. A variety of experimental techniques has been used to probe the structural parameters and degree of order in these alloys. Their magnetic properties have been investigated using the conventional methods, while the spin polarization has been probed by point contact Andreev reflection technique. The experimentally obtained values of saturation magnetization are

Magnon spintronics in non-collinear magnetic insulator/metal heterostructures

NARCIS (Netherlands)

Aqeel, Aisha

2017-01-01

The research presented in this thesis focuses on the growth of complex magnetic materials with unique magnetic properties and experimental investigation of fundamental spintronics phenomena in these magnetic insulators with magnetic orders varying from collinear to noncollinear chiral spin

Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys

DEFF Research Database (Denmark)

Xu, Y. B.; Hassan, S. S. A.; Wong, P. K. J.

2008-01-01

Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on Ga......As(100) and the unit cell of the Fe3O4 was found to be rotated by 45 degrees to match the gallium arsenide GaAs. The films were found to have a bulk-like moment down to 3-4 nm and a low coercivity indicating a high-quality magnetic interface. The magnetization hysteresis loops of the ultrathin films...... are controlled by uniaxial magnetic anisotropy. The dynamic response of the sample shows a heavily damped precessional response to the applied field pulses. In the Heusler alloy system of Co-2 MnGa on GaAs, we found that the magnetic moment was reduced for thicknesses down to 10 nm, which may account...

Rare earth-based quaternary Heusler compounds MCoVZ (M = Lu, Y; Z = Si, Ge with tunable band characteristics for potential spintronic applications

Directory of Open Access Journals (Sweden)

Xiaotian Wang

2017-11-01

Full Text Available Magnetic Heusler compounds (MHCs have recently attracted great attention since these types of material provide novel functionalities in spintronic and magneto-electronic devices. Among the MHCs, some compounds have been predicted to be spin-filter semiconductors [also called magnetic semiconductors (MSs], spin-gapless semiconductors (SGSs or half-metals (HMs. In this work, by means of first-principles calculations, it is demonstrated that rare earth-based equiatomic quaternary Heusler (EQH compounds with the formula MCoVZ (M = Lu, Y; Z = Si, Ge are new spin-filter semiconductors with total magnetic moments of 3 µB. Furthermore, under uniform strain, there are physical transitions from spin-filter semiconductor (MS → SGS → HM for EQH compounds with the formula LuCoVZ, and from HM → SGS → MS → SGS → HM for EQH compounds with the formula YCoVZ. Remarkably, for YCoVZ EQH compounds there are not only diverse physical transitions, but also different types of spin-gapless feature that can be observed with changing lattice constants. The structural stability of these four EQH compounds is also examined from the points of view of formation energy, cohesive energy and mechanical behaviour. This work is likely to inspire consideration of rare earth-based EQH compounds for application in future spintronic and magneto-electronic devices.

Tunneling anisotropic magnetoresistance in C60-based organic spintronic systems

NARCIS (Netherlands)

Wang, Kai; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

2014-01-01

C 60 fullerenes are interesting molecular semiconductors for spintronics since they exhibit weak spin-orbit and hyperfine interactions, which is a prerequisite for long spin lifetimes. We report spin-polarized transport in spin-valve-like structures containing ultrathin (<10 nm) C 60 layers,

Magnetic polyoxometalates: from molecular magnetism to molecular spintronics and quantum computing.

Science.gov (United States)

Clemente-Juan, Juan M; Coronado, Eugenio; Gaita-Ariño, Alejandro

2012-11-21

In this review we discuss the relevance of polyoxometalate (POM) chemistry to provide model objects in molecular magnetism. We present several potential applications in nanomagnetism, in particular, in molecular spintronics and quantum computing.

Introduction to spintronics

CERN Document Server

Bandyopadhyay, Supriyo

2008-01-01

The Early History of Spin Spin The Bohr Planetary Model and Space Quantization The Birth of "Spin" The Stern-Gerlach Experiment The Advent of Spintronics The Quantum Mechanics of Spin Pauli Spin Matrices The Pauli Equation and Spinors More on the Pauli Equation Extending the Pauli Equation - the Dirac Equation The Time Independent Dirac Equation Appendix The Bloch Sphere The Spinor and the "Qubit" The Bloch Sphere Concept Evolution of a Spinor Spin-1/2 Particle in a Constant Magnetic Field: Larmor Precession Preparing to Derive the Rabi Formula The Rabi Formula The Density Matrix The Density Matrix Concept: Case of a Pure State Properties of the Density Matrix Pure Versus Mixed State Concept of the Bloch Ball Time Evolution of the Density Matrix: Case of Mixed State The Relaxation Times T1 and T2 and the Bloch Equations Spin Orbit Interaction Spin Orbit Interaction in a Solid Magneto-Electric Sub-Bands in Quantum Confined Structures in the Presence of Spin-Orbit Interaction Dispersion Relations of Spin Resolv...

Magnetization Dynamics in Two Novel Current-Driven Spintronic Memory Cell Structures

KAUST Repository

Velazquez-Rizo, Martin

2017-01-01

In this work, two new spintronic memory cell structures are proposed. The first cell uses the diffusion of polarized spins into ferromagnets with perpendicular anisotropy to tilt their magnetization followed by their dipolar coupling to a fixed

Training device for nuclear power plant operators

International Nuclear Information System (INIS)

Schoessow, G. J.

1985-01-01

A simulated nuclear energy power plant system with visible internal working components comprising a reactor adapted to contain a liquid with heating elements submerged in the liquid and capable of heating the liquid to an elevated temperature, a steam generator containing water and a heat exchanger means to receive the liquid at an elevated temperature, transform the water to steam, and return the spent liquid to the reactor; a steam turbine receiving high energy steam to drive the turbine and discharging low energy steam to a condenser where the low energy steam is condensed to water which is returned to the steam generator; an electric generator driven by the turbine; indicating means to identify the physical status of the reactor and its contents; and manual and automatic controls to selectively establish normal or abnormal operating conditions in the reactor, steam generator, pressurizer, turbine, electric generator, condenser, and pumps; and to be selectively adjusted to bring the reactor to acceptable operating condition after being placed in an abnormal operation. This device is particularly useful as an education device in demonstrating nuclear reactor operations and in training operating personnel for nuclear reactor systems and also as a device for conducting research on various safety systems to improve the safety of nuclear power plants

Spintronic effects in metallic, semiconductor, metal-oxide and metal-semiconductor heterostructures

Energy Technology Data Exchange (ETDEWEB)

Bratkovsky, A M [Hewlett-Packard Laboratories, 1501 Page Mill Road, MS 1123, Palo Alto, CA 94304 (United States)

2008-02-15

Spintronics is a rapidly growing field focusing on phenomena and related devices essentially dependent on spin transport. Some of them are already an established part of microelectronics. We review recent theoretical and experimental advances in achieving large spin injection efficiency (polarization of current) and accumulated spin polarization. These include tunnel and giant magnetoresistance, spin-torque and spin-orbit effects on electron transport in various heterostructures. We give a microscopic description of spin tunneling through oxide and modified Schottky barriers between a ferromagnet (FM) and a semiconductor (S). It is shown that in such FM-S junctions electrons with a certain spin projection can be efficiently injected into (or extracted from) S, while electrons with the opposite spin can accumulate in S near the interface. The criterion for efficient injection is opposite to a known Rashba criterion, since the barrier should be rather transparent. In degenerate semiconductors, extraction of spin can proceed at low temperatures. We mention a few novel spin-valve ultrafast devices with small dissipated power: a magnetic sensor, a spin transistor, an amplifier, a frequency multiplier, a square-law detector and a source of polarized radiation. We also discuss effects related to spin-orbital interactions, such as the spin Hall effect (SHE) and a recently predicted positive magnetoresistance accompanying SHE. Some esoteric devices such as 'spinFET', interacting spin logic and spin-based quantum computing are discussed and problems with their realization are highlighted. We demonstrate that the so-called 'ferroelectric tunnel junctions' are unlikely to provide additional functionality because in all realistic situations the ferroelectric barrier would be split into domains by the depolarizing field.

Spintronic effects in metallic, semiconductor, metal-oxide and metal-semiconductor heterostructures

International Nuclear Information System (INIS)

Bratkovsky, A M

2008-01-01

Spintronics is a rapidly growing field focusing on phenomena and related devices essentially dependent on spin transport. Some of them are already an established part of microelectronics. We review recent theoretical and experimental advances in achieving large spin injection efficiency (polarization of current) and accumulated spin polarization. These include tunnel and giant magnetoresistance, spin-torque and spin-orbit effects on electron transport in various heterostructures. We give a microscopic description of spin tunneling through oxide and modified Schottky barriers between a ferromagnet (FM) and a semiconductor (S). It is shown that in such FM-S junctions electrons with a certain spin projection can be efficiently injected into (or extracted from) S, while electrons with the opposite spin can accumulate in S near the interface. The criterion for efficient injection is opposite to a known Rashba criterion, since the barrier should be rather transparent. In degenerate semiconductors, extraction of spin can proceed at low temperatures. We mention a few novel spin-valve ultrafast devices with small dissipated power: a magnetic sensor, a spin transistor, an amplifier, a frequency multiplier, a square-law detector and a source of polarized radiation. We also discuss effects related to spin-orbital interactions, such as the spin Hall effect (SHE) and a recently predicted positive magnetoresistance accompanying SHE. Some esoteric devices such as 'spinFET', interacting spin logic and spin-based quantum computing are discussed and problems with their realization are highlighted. We demonstrate that the so-called 'ferroelectric tunnel junctions' are unlikely to provide additional functionality because in all realistic situations the ferroelectric barrier would be split into domains by the depolarizing field

Spintronic effects in metallic, semiconductor, metal oxide and metal semiconductor heterostructures

Science.gov (United States)

Bratkovsky, A. M.

2008-02-01

Spintronics is a rapidly growing field focusing on phenomena and related devices essentially dependent on spin transport. Some of them are already an established part of microelectronics. We review recent theoretical and experimental advances in achieving large spin injection efficiency (polarization of current) and accumulated spin polarization. These include tunnel and giant magnetoresistance, spin-torque and spin-orbit effects on electron transport in various heterostructures. We give a microscopic description of spin tunneling through oxide and modified Schottky barriers between a ferromagnet (FM) and a semiconductor (S). It is shown that in such FM-S junctions electrons with a certain spin projection can be efficiently injected into (or extracted from) S, while electrons with the opposite spin can accumulate in S near the interface. The criterion for efficient injection is opposite to a known Rashba criterion, since the barrier should be rather transparent. In degenerate semiconductors, extraction of spin can proceed at low temperatures. We mention a few novel spin-valve ultrafast devices with small dissipated power: a magnetic sensor, a spin transistor, an amplifier, a frequency multiplier, a square-law detector and a source of polarized radiation. We also discuss effects related to spin-orbital interactions, such as the spin Hall effect (SHE) and a recently predicted positive magnetoresistance accompanying SHE. Some esoteric devices such as 'spinFET', interacting spin logic and spin-based quantum computing are discussed and problems with their realization are highlighted. We demonstrate that the so-called 'ferroelectric tunnel junctions' are unlikely to provide additional functionality because in all realistic situations the ferroelectric barrier would be split into domains by the depolarizing field.

Single atom spintronics

International Nuclear Information System (INIS)

Sullivan, M. R.; Armstrong, J. N.; Hua, S. Z.; Chopra, H. D.

2005-01-01

Full text: Single atom spintronics (SASS) represents the ultimate physical limit in device miniaturization. SASS is characterized by ballistic electron transport, and is a fertile ground for exploring new phenomena. In addition to the 'stationary' (field independent) scattering centers that have a small and fixed contribution to total transmission probability of electron waves, domain walls constitute an additional and enhanced source of scattering in these magnetic quantum point contacts (QPCs), the latter being both field and spin-dependent. Through the measurement of complete hysteresis loops as a function of quantized conductance, we present definitive evidence of enhanced backscattering of electron waves by atomically sharp domain walls in QPCs formed between microfabricated thin films [1]. Since domain walls move in a magnetic field, the magnitude of spin-dependent scattering changes as the QPC is cycled along its hysteresis loop. For example, as shown in the inset in Fig. 1, from zero towards saturation in a given field direction, the resistance varies as the wall is being swept away, whereas the resistance is constant upon returning from saturation towards zero, since in this segment of the hysteresis loop no domain wall is present across the contact. The observed spin-valve like behavior is realized by control over wall width and shape anisotropy. This behavior also unmistakably sets itself apart from any mechanical artifacts; additionally, measurements made on single atom contacts provide an artifact-free environment [2]. Intuitively, it is simpler to organize the observed BMR data according to all possible transitions between different conductance plateaus, as shown by the dotted line in Fig. 1; the solid circles show experimental data for Co, which follows the predicted scheme. Requisite elements for the observation of the effect will be discussed in detail along with a review of state of research in this field. Practically, the challenge lies in making

Room-temperature spintronic effects in Alq3-based hybrid devices

NARCIS (Netherlands)

Dediu, V.; Hueso, L.E.; Bergenti, I; Riminucci, A.; Borgatti, F.; Graziosi, P.; Newby, C.; Casoli, F.; de Jong, Machiel Pieter; Taliani, C.; Zhan, Y.

2008-01-01

We report on efficient spin polarized injection and transport in long 102 nm channels of Alq3 organic semiconductor. We employ vertical spin valve devices with a direct interface between the bottom manganite electrode and Alq3, while the top-electrode geometry consists of an insulating tunnel

Spintronic and transport properties of linear atomic strings of transition metals (Fe, Co, Ni)

Energy Technology Data Exchange (ETDEWEB)

Tyagi, Neha, E-mail: nehatyagi.phy@gmail.com [Department of Applied Physics, Delhi Technological University, New Delhi (India); Jaiswal, Neeraj K. [Discipline of Physics, PDPM-Indian Institute of Information Technology, Design & Manufacturing, Jabalpur (India); Srivastava, Pankaj [Nanomaterials Research Group, ABV-Indian Institute of Information Technology & Management, Gwalior (India)

2016-05-06

In the present work, first-principles investigations have been performed to study the spintronic and transport properties of linear atomic strings of Fe, Co and Ni. The structural stabilities of the considered strings were compared on the basis of binding energies which revealed that all the strings are energetically feasible to be achieved. Further, all the considered strings are found to be ferromagnetic and the observed magnetic moment ranges from 1.38 to 1.71 μ{sub B}. The observed transport properties and high spin polarization points towards their potential for nano interconnects and spintronic applications.

Operation guide device for nuclear power plants

International Nuclear Information System (INIS)

Araki, Tsuneyasu

1982-01-01

Purpose: To enable to maintain the soundness of nuclear fuels and each of equipments by compensating the effect of the xenon density on the reactor core thermal power resulted upon load following operation of a nuclear reactor. Constitution: The device comprises an instrumentation system for measuring the status of the nuclear reactor, a reactor core performance calculator for calculating the reactor core performance based on the output from the instrumentation system, a xenon density calculator for calculating the xenon density based on the output from the performance calculator, a memory unit for storing the output from the reactor core performance calculator and the xenon density calculator and for transferring the stored memory to a nuclear reactor status forecasting device and an alternative load pattern searching device for searching, in cooperation with the memory unit, an alternative load pattern which is within an operation restrictive condition and most closed to a demanded load pattern when a monitor for the deviation from the flowrate distribution detects the deviation from the operation restrictive conditions. (Yoshino, Y.)

EPICS: operating system independent device/driver support

International Nuclear Information System (INIS)

Kraimer, M.R.

2003-01-01

Originally EPICS input/output controllers (IOCs) were only supported on VME-based systems running the vxWorks operating system. Now IOCs are supported on many systems: vxWorks, RTEMS, Solaris, HPUX, Linux, WIN32, and Darwin. A challenge is to provide operating-system-independent device and driver support. This paper presents some techniques for providing such support. EPICS (Experimental Physics and Industrial Control System) is a set of software tools, libraries, and applications developed collaboratively and used worldwide to create distributed, real-time control systems for scientific instruments such as particle accelerators, telescopes, and other large scientific experiments. An important component of all EPICS-based control systems is a collection of input/output controllers (IOCs). An IOC has three primary components: (1) a real-time database; (2) channel access, which provides network access to the database; and (3) device/driver support for interfacing to equipment. This paper describes some projects related to providing device/driver support on non-vxWorks systems. In order to support IOCs on platforms other than vxWorks, operating-system-independent (OSI) application program interfaces (APIs) were defined for threads, semaphores, timers, etc. Providing support for a new platform consists of providing an operating-system-dependent implementation of the OSI APIs.

An open source device for operant licking in rats.

Science.gov (United States)

Longley, Matthew; Willis, Ethan L; Tay, Cindy X; Chen, Hao

2017-01-01

We created an easy-to-use device for operant licking experiments and another device that records environmental variables. Both devices use the Raspberry Pi computer to obtain data from multiple input devices (e.g., radio frequency identification tag readers, touch and motion sensors, environmental sensors) and activate output devices (e.g., LED lights, syringe pumps) as needed. Data gathered from these devices are stored locally on the computer but can be automatically transferred to a remote server via a wireless network. We tested the operant device by training rats to obtain either sucrose or water under the control of a fixed ratio, a variable ratio, or a progressive ratio reinforcement schedule. The lick data demonstrated that the device has sufficient precision and time resolution to record the fast licking behavior of rats. Data from the environment monitoring device also showed reliable measurements. By providing the source code and 3D design under an open source license, we believe these examples will stimulate innovation in behavioral studies. The source code can be found at http://github.com/chen42/openbehavior.

Optically controlled multiple switching operations of DNA biopolymer devices

International Nuclear Information System (INIS)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

2015-01-01

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

Optically controlled multiple switching operations of DNA biopolymer devices

Energy Technology Data Exchange (ETDEWEB)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2015-12-21

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

Prediction of novel interface-driven spintronic effects

International Nuclear Information System (INIS)

Bhattacharjee, Satadeep; Singh, Surendra; Bellaiche, L; Wang, D; Viret, M

2014-01-01

The recently proposed coupling between the angular momentum density and magnetic moment (Raeliarijaona et al 2013 Phys. Rev. Lett. 110 137205) is shown here to result in the prediction of (i) novel spin currents generated by an electrical current and (ii) new electrical currents induced by a spin current in systems possessing specific interfaces between two different materials. Some of these spin (electrical) currents can be reversed near the interface by reversing the applied electrical (spin) current. Similarities and differences between these novel spintronic effects and the well-known spin Hall and inverse spin Hall effects are also discussed. (paper)

Operation aid device upon periodical inspection of nuclear power plant

International Nuclear Information System (INIS)

Fukusaka, Ryoji.

1997-01-01

The present invention provides an operation aid device upon periodical inspection of a nuclear power plant, capable of controlling a plurality of control rods safely at good operation efficiency while maintaining subcritical state. Namely, a fuel exchange computer controls an operation for exchanging fuel assemblies upon periodical inspection. An operation aiding computer aids the exchanging operation of fuel assemblies. A control rod position monitoring device allows withdrawal of one control rod under the condition of establishment of entire control rod insertion signal upon operation of exchanging fuel assemblies. Whether all of the four fuel assemblies around one control rod have been entirely taken out or not is judged based on information on the fuel assembly exchanging operation. When conditions for the judgement for operation aiding computer are established, the all insertion signals for the entire control rods as the condition for the withdrawal of the control rods are bypassed, and operation enable signals for plurality control rods are outputted to a control rod manual operation device. (I.S.)

Spin voltage generation through optical excitation of complementary spin populations

Science.gov (United States)

Bottegoni, Federico; Celebrano, Michele; Bollani, Monica; Biagioni, Paolo; Isella, Giovanni; Ciccacci, Franco; Finazzi, Marco

2014-08-01

By exploiting the spin degree of freedom of carriers inside electronic devices, spintronics has a huge potential for quantum computation and dissipationless interconnects. Pure spin currents in spintronic devices should be driven by a spin voltage generator, able to drive the spin distribution out of equilibrium without inducing charge currents. Ideally, such a generator should operate at room temperature, be highly integrable with existing semiconductor technology, and not interfere with other spintronic building blocks that make use of ferromagnetic materials. Here we demonstrate a device that matches these requirements by realizing the spintronic equivalent of a photovoltaic generator. Whereas a photovoltaic generator spatially separates photoexcited electrons and holes, our device exploits circularly polarized light to produce two spatially well-defined electron populations with opposite in-plane spin projections. This is achieved by modulating the phase and amplitude of the light wavefronts entering a semiconductor (germanium) with a patterned metal overlayer (platinum). The resulting light diffraction pattern features a spatially modulated chirality inside the semiconductor, which locally excites spin-polarized electrons thanks to electric dipole selection rules.

Hydraulic screw fastening devices - design, maintenance, operational experience

International Nuclear Information System (INIS)

Lachner.

1976-01-01

With hydraulic screw fastening devices, pretension values with a maximum deviation of +-2.5% from the rated value can be achieved. This high degree of pretension accuracy is of considerable importance with regard to the safety factor required for the screw connection between reactor vessel head and reactor vessel. The operating rhythm of a nuclear power station with its refuelling art regular intervals makes further demands on the screw fastening device, in particular in connection with the transport of screws and for nuts. The necessary installations extend the screw fastening device into a combination of a high-pressure hydraulic cylinder system with an electrical or pneumoelectrical driving unit and an electrical control unit. Maintenance work is complicated by the large number of identical, highly stressed structural elements in connection with an unfavourable relation operating time/outage time. The problems have been perpetually reduced by close cooperation between the manufacturers and users of screw fastening devices. (orig./AK) [de

30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate...

Anisotropic sensor and memory device with a ferromagnetic tunnel barrier as the only magnetic element.

Science.gov (United States)

Lόpez-Mir, L; Frontera, C; Aramberri, H; Bouzehouane, K; Cisneros-Fernández, J; Bozzo, B; Balcells, L; Martínez, B

2018-01-16

Multiple spin functionalities are probed on Pt/La 2 Co 0.8 Mn 1.2 O 6 /Nb:SrTiO 3 , a device composed by a ferromagnetic insulating barrier sandwiched between non-magnetic electrodes. Uniquely, La 2 Co 0.8 Mn 1.2 O 6 thin films present strong perpendicular magnetic anisotropy of magnetocrystalline origin, property of major interest for spintronics. The junction has an estimated spin-filtering efficiency of 99.7% and tunneling anisotropic magnetoresistance (TAMR) values up to 30% at low temperatures. This remarkable angular dependence of the magnetoresistance is associated with the magnetic anisotropy whose origin lies in the large spin-orbit interaction of Co 2+ which is additionally tuned by the strain of the crystal lattice. Furthermore, we found that the junction can operate as an electrically readable magnetic memory device. The findings of this work demonstrate that a single ferromagnetic insulating barrier with strong magnetocrystalline anisotropy is sufficient for realizing sensor and memory functionalities in a tunneling device based on TAMR.

Proposal for an All-Spin Artificial Neural Network: Emulating Neural and Synaptic Functionalities Through Domain Wall Motion in Ferromagnets.

Science.gov (United States)

Sengupta, Abhronil; Shim, Yong; Roy, Kaushik

2016-12-01

Non-Boolean computing based on emerging post-CMOS technologies can potentially pave the way for low-power neural computing platforms. However, existing work on such emerging neuromorphic architectures have either focused on solely mimicking the neuron, or the synapse functionality. While memristive devices have been proposed to emulate biological synapses, spintronic devices have proved to be efficient at performing the thresholding operation of the neuron at ultra-low currents. In this work, we propose an All-Spin Artificial Neural Network where a single spintronic device acts as the basic building block of the system. The device offers a direct mapping to synapse and neuron functionalities in the brain while inter-layer network communication is accomplished via CMOS transistors. To the best of our knowledge, this is the first demonstration of a neural architecture where a single nanoelectronic device is able to mimic both neurons and synapses. The ultra-low voltage operation of low resistance magneto-metallic neurons enables the low-voltage operation of the array of spintronic synapses, thereby leading to ultra-low power neural architectures. Device-level simulations, calibrated to experimental results, was used to drive the circuit and system level simulations of the neural network for a standard pattern recognition problem. Simulation studies indicate energy savings by  ∼  100× in comparison to a corresponding digital/analog CMOS neuron implementation.

The Spin Torque Lego - from spin torque nano-devices to advanced computing architectures

Science.gov (United States)

Grollier, Julie

2013-03-01

Spin transfer torque (STT), predicted in 1996, and first observed around 2000, brought spintronic devices to the realm of active elements. A whole class of new devices, based on the combined effects of STT for writing and Giant Magneto-Resistance or Tunnel Magneto-Resistance for reading has emerged. The second generation of MRAMs, based on spin torque writing : the STT-RAM, is under industrial development and should be out on the market in three years. But spin torque devices are not limited to binary memories. We will rapidly present how the spin torque effect also allows to implement non-linear nano-oscillators, spin-wave emitters, controlled stochastic devices and microwave nano-detectors. What is extremely interesting is that all these functionalities can be obtained using the same materials, the exact same stack, simply by changing the device geometry and its bias conditions. So these different devices can be seen as Lego bricks, each brick with its own functionality. During this talk, I will show how spin torque can be engineered to build new bricks, such as the Spintronic Memristor, an artificial magnetic nano-synapse. I will then give hints on how to assemble these bricks in order to build novel types of computing architectures, with a special focus on neuromorphic circuits. Financial support by the European Research Council Starting Grant NanoBrain (ERC 2010 Stg 259068) is acknowledged.

The Role of a Mental Model in Learning to Operate a Device.

Science.gov (United States)

Kieras, David E.; Bovair, Susan

1984-01-01

Describes three studies concerned with learning to operate a control panel device and how this learning is affected by understanding a device model that describes its internal mechanism. Results indicate benefits of a device model depend on whether it supports direct inference of exact steps required to operate the device. (Author/MBR)

Towards automated assistance for operating home medical devices.

Science.gov (United States)

Gao, Zan; Detyniecki, Marcin; Chen, Ming-Yu; Wu, Wen; Hauptmann, Alexander G; Wactlar, Howard D

2010-01-01

To detect errors when subjects operate a home medical device, we observe them with multiple cameras. We then perform action recognition with a robust approach to recognize action information based on explicitly encoding motion information. This algorithm detects interest points and encodes not only their local appearance but also explicitly models local motion. Our goal is to recognize individual human actions in the operations of a home medical device to see if the patient has correctly performed the required actions in the prescribed sequence. Using a specific infusion pump as a test case, requiring 22 operation steps from 6 action classes, our best classifier selects high likelihood action estimates from 4 available cameras, to obtain an average class recognition rate of 69%.

System and method of operating toroidal magnetic confinement devices

Science.gov (United States)

Chance, M.S.; Jardin, S.C.; Stix, T.H.; Grimm, R.C.; Manickam, J.; Okabayashi, M.

1984-08-30

This invention pertains to methods and arrangements for attaining high beta values in plasma confinement devices. More specifically, this invention pertains to methods for accessing the second stability region of operation in toroidal magnetic confinement devices.

Oxide thin films for spintronics application growth and characterization

OpenAIRE

Popovici, Nicoleta, 1973-

2009-01-01

Tese de doutoramento, Física (Física), Universidade de Lisboa, Faculdade de Ciências, 2009 During my PhD research I have synthesized thin films of a material known as a diluted magnetic semiconductor (DMS) using the pulsed laser deposition (PLD) technique. This material is envisioned to be of importance in the emerging field of spintronics where both the charge and the spin of the carriers can be combined to yield unique functionalities. It was envisaged that if spin polarized charge carri...

Summer School on Spintronics

CERN Document Server

Wolf, Stuart; Idzerda, Yves

2003-01-01

Stuart Wolf This book originated as a series of lectures that were given as part of a Summer School on Spintronics in the end of August, 1998 at Lake Tahoe, Nevada. It has taken some time to get these lectures in a form suitable for this book and so the process has been an iterative one to provide current information on the topics that are covered. There are some topics that have developed in the intervening years and we have tried to at least alert the readers to them in the Introduction where a rather complete set of references is provided to the current state of the art. The field of magnetism, once thought to be dead or dying, has seen a remarkable rebirth in the last decade and promises to get even more important as we enter the new millennium. This rebirth is due to some very new insight into how the spin degree of freedom of both electrons and nucleons can play a role in a new type of electronics that utilizes the spin in addition to or in place of the charge. For this new field to mature and prosper, ...

A Test Device Module of the Step Motor Driver for HANARO CAR Operation

Energy Technology Data Exchange (ETDEWEB)

Im, Yun-Taek; Doo, Seung-Gyu; Shin, Jin-Won; Kim, Ki-Hyun; Choi, Young-San; Lee, Jung-Hee; Kim, Hyung-Kyoo; Lee, Choong-Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The brand-new control system is reliable and has advantages compared with the old control system, and the installed system covers all functional operations of old system. Nevertheless, packaged RTP systems do not include a step motor or driver, and it is necessary to develop a proper test device to check the step motor and driver without using the RTP system. In particular, the operation of a CAR (Control Absorber Rod) requires many complicated procedures. Occasionally, it takes significant time to prepare for a field test. In this work, a test device module for a step motor diver is shown to emulate a HANARO CAR operation, and the test device system architecture, operational principle, and experiment results are presented. A commercial 8-bit μ-processor is applied to implement the device. A portable test device for HANARO CAR operation is presented. An 8-bit μ-controller is used to emulate a HANARO CAR operation. The digital interface, as well as the functional operation, of the test device module matches that of the currently used driver. This device can be used to check the functional validity of the step motor and driver.

Detection of Special Operations Forces Using Night Vision Devices

Energy Technology Data Exchange (ETDEWEB)

Smith, C.M.

2001-10-22

Night vision devices, such image intensifiers and infrared imagers, are readily available to a host of nations, organizations, and individuals through international commerce. Once the trademark of special operations units, these devices are widely advertised to ''turn night into day''. In truth, they cannot accomplish this formidable task, but they do offer impressive enhancement of vision in limited light scenarios through electronically generated images. Image intensifiers and infrared imagers are both electronic devices for enhancing vision in the dark. However, each is based upon a totally different physical phenomenon. Image intensifiers amplify the available light energy whereas infrared imagers detect the thermal energy radiated from all objects. Because of this, each device operates from energy which is present in a different portion of the electromagnetic spectrum. This leads to differences in the ability of each device to detect and/or identify objects. This report is a compilation of the available information on both state-of-the-art image intensifiers and infrared imagers. Image intensifiers developed in the United States, as well as some foreign made image intensifiers, are discussed. Image intensifiers are categorized according to their spectral response and sensitivity using the nomenclature of GEN I, GEN II, and GEN III. As the first generation of image intensifiers, GEN I, were large and of limited performance, this report will deal with only GEN II and GEN III equipment. Infrared imagers are generally categorized according to their spectral response, sensor materials, and related sensor operating temperature using the nomenclature Medium Wavelength Infrared (MWIR) Cooled and Long Wavelength Infrared (LWIR) Uncooled. MWIR Cooled refers to infrared imagers which operate in the 3 to 5 {micro}m wavelength electromagnetic spectral region and require either mechanical or thermoelectric coolers to keep the sensors operating at 77 K

Monitoring device for reactor operation

International Nuclear Information System (INIS)

Sakagami, Masaharu.

1980-01-01

Purpose: To increase the freedom for the power control due to control rod operation and flow rate control, as well as prevent fuel failures by the provision of a power distribution forecasting device for forecasting the changes in the reactor core power distribution and a device for calculating the fuel performance index and judging to display the calculated values. Constitution: The results for the calculation of the reactor core power distribution from a process computer that processes each of measuring signals of a nuclear power plant are used as inputs to a fuel power history calculator to constitute the power history up to the present time for each of the fuels. The date are inputted to a fuel performance index calculator to calculate the fuel performance index at present time for each of the fuels. Changes in the power distribution are forecast in a forecasting device for reactor power distribution relative to the changes in the control variables of a control variable memory unit and the date are inputted to a fuel power history calculator to forecast the power changes for each of the fuels. The amount of the power changes is inputted to a fuel performance index calculator and a fuel performance indicating and judging device judges and displays if they exceed a predetermined value. (Seki, T.)

Inter-operator and inter-device agreement and reliability of the SEM Scanner.

Science.gov (United States)

Clendenin, Marta; Jaradeh, Kindah; Shamirian, Anasheh; Rhodes, Shannon L

2015-02-01

The SEM Scanner is a medical device designed for use by healthcare providers as part of pressure ulcer prevention programs. The objective of this study was to evaluate the inter-rater and inter-device agreement and reliability of the SEM Scanner. Thirty-one (31) volunteers free of pressure ulcers or broken skin at the sternum, sacrum, and heels were assessed with the SEM Scanner. Each of three operators utilized each of three devices to collect readings from four anatomical sites (sternum, sacrum, left and right heels) on each subject for a total of 108 readings per subject collected over approximately 30 min. For each combination of operator-device-anatomical site, three SEM readings were collected. Inter-operator and inter-device agreement and reliability were estimated. Over the course of this study, more than 3000 SEM Scanner readings were collected. Agreement between operators was good with mean differences ranging from -0.01 to 0.11. Inter-operator and inter-device reliability exceeded 0.80 at all anatomical sites assessed. The results of this study demonstrate the high reliability and good agreement of the SEM Scanner across different operators and different devices. Given the limitations of current methods to prevent and detect pressure ulcers, the SEM Scanner shows promise as an objective, reliable tool for assessing the presence or absence of pressure-induced tissue damage such as pressure ulcers. Copyright © 2015 Bruin Biometrics, LLC. Published by Elsevier Ltd.. All rights reserved.

System and method of operating toroidal magnetic confinement devices

Science.gov (United States)

Chance, Morrell S.; Jardin, Stephen C.; Stix, Thomas H.; Grimm, deceased, Ray C.; Manickam, Janardhan; Okabayashi, Michio

1987-01-01

For toroidal magnetic confinement devices the second region of stability against ballooning modes can be accessed with controlled operation. Under certain modes of operation, the first and second stability regions may be joined together. Accessing the second region of stability is accomplished by forming a bean-shaped plasma and increasing the indentation until a critical value of indentation is reached. A pusher coil, located at the inner-major-radius side of the device, is engaged to form a bean-shaped poloidal cross-section in the plasma.

Piezo Voltage Controlled Planar Hall Effect Devices.

Science.gov (United States)

Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

2016-06-22

The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

Voltage-Controlled Reconfigurable Spin-Wave Nanochannels and Logic Devices

Science.gov (United States)

Rana, Bivas; Otani, YoshiChika

2018-01-01

Propagating spin waves (SWs) promise to be a potential information carrier in future spintronics devices with lower power consumption. Here, we propose reconfigurable nanochannels (NCs) generated by voltage-controlled magnetic anisotropy (VCMA) in an ultrathin ferromagnetic waveguide for SW propagation. Numerical micromagnetic simulations are performed to demonstrate the confinement of magnetostatic forward volumelike spin waves in NCs by VCMA. We demonstrate that the NCs, with a width down to a few tens of a nanometer, can be configured either into a straight or curved structure on an extended SW waveguide. The key advantage is that either a single NC or any combination of a number of NCs can be easily configured by VCMA for simultaneous propagation of SWs either with the same or different wave vectors according to our needs. Furthermore, we demonstrate the logic operation of a voltage-controlled magnonic xnor and universal nand gate and propose a voltage-controlled reconfigurable SW switch for the development of a multiplexer and demultiplexer. We find that the NCs and logic devices can even be functioning in the absence of the external-bias magnetic field. These results are a step towards the development of all-voltage-controlled magnonic devices with an ultralow power consumption.

Operation control device for nuclear power plants

International Nuclear Information System (INIS)

Suto, Osamu.

1982-01-01

Purpose: To render the controlling functions of a central control console more centralized by constituting the operation controls for a nuclear power plant with computer systems having substantially independent functions such as those of plant monitor controls, reactor monitor management and CRT display and decreasing interactions between each of the systems. Constitution: An input/output device for the input of process data for a nuclear power plant and indication data for a plant control console is connected to a plant supervisory and control computer system and a display computer system, the plant supervisory control computer system and a reactor and management computer system are connected with a CRT display control device, a printer and a CRT display input/output device, and the display computer system is connected with the CRT display control device and the CRT display unit on the central control console, whereby process input can be processed and displayed at high speed. (Yoshino, Y.)

The Operation of a Domestic Interface Device for the HANARO Control Rod

International Nuclear Information System (INIS)

Choi, Young San; Kim, Sang Jin; Lee, Jung Hee; Kim, Hyung Kyoo

2010-01-01

The interface device for the HANARO control rod which was supplied by a foreign company put difficulties on reactor operation due to the obsolescence of the products and lukewarm technical support from the manufacturer. The development of the interface device based on domestic technology has been completed in order to solve the problems in this issue and to ensure safe and reliable reactor operation. This paper describes the development process of the domestic interface device conducted which was over 5 years, the field test results, and the reactor operation application results

Topological Material-Based Spin Devices

Science.gov (United States)

Zhang, Minhao; Wang, Xuefeng

Three-dimensional topological insulators have insulating bulk and gapless helical surface states. One of the most fascinating properties of the metallic surface states is the spin-momentum helical locking. The giant current-driven torques on the magnetic layer have been discovered in TI/ferromagnet bilayers originating from the spin-momentum helical locking, enabling the efficient magnetization switching with a low current density. We demonstrated the current-direction dependent on-off state in TIs-based spin valve devices for memory and logic applications. Further, we demonstrated the Bi2Se3 system will go from a topologically nontrivial state to a topologically trivial state when Bi atoms are replaced by lighter In atoms. Here, topologically trivial metal (BixIny)2 Se3 with high mobility also facilitates the realization of its application in multifunctional spintronic devices.

Aerosol can puncture device operational test plan

International Nuclear Information System (INIS)

Leist, K.J.

1994-01-01

Puncturing of aerosol cans is performed in the Waste Receiving and Processing Facility Module 1 (WRAP 1) process as a requirement of the waste disposal acceptance criteria for both transuranic (TRU) waste and low-level waste (LLW). These cans have contained such things as paints, lubricating oils, paint removers, insecticides, and cleaning supplies which were used in radioactive facilities. Due to Westinghouse Hanford Company (WHC) Fire Protection concerns of the baseline system's fire/explosion proof characteristics, a study was undertaken to compare the baseline system's design to commercially available puncturing devices. While the study found no areas which might indicate a risk of fire or explosion, WHC Fire Protection determined that the puncturing system must have a demonstrated record of safe operation. This could be obtained either by testing the baseline design by an independent laboratory, or by substituting a commercially available device. As a result of these efforts, the commercially available Aerosolv can puncturing device was chosen to replace the baseline design. Two concerns were raised with the system. Premature blinding of the coalescing/carbon filter, due to its proximity to the puncture and draining operation; and overpressurization of the collection bottle due to its small volume and by blinding of the filter assembly. As a result of these concerns, testing was deemed necessary. The objective of this report is to outline test procedures for the Aerosolv

Considerations of device and operational flexibility in FER

International Nuclear Information System (INIS)

Sugihara, Masayoshi; Miki, Nobuharu; Nishio, Satoshi; Yamada, Masao; Yamamoto, Shin

1988-01-01

Expected physics uncertainties in DT burning plasma of FER, which may not be removed completely at the start of construction or DT operation, are reviewed. Several possible device and operational flexibility scenarios to cope with these uncertainties are considered. They are (1) Plasma size enlargement scenario, (2) Plasma shape flexibility scenario, (3) Heating/Current drive/Control system flexibility scenario, (4) Impurity control system flexibility scenario and (5) Advanced operation scenario. Feasibility of these flexibility scenarios are examined and shown to be practicable. However, careful assessment of the physics data base is necessary at the start of construction and DT operation to proceed to actually implement these flexibilities in FER. (author)

Particle interaction and displacement damage in silicon devices operated in radiation environments

International Nuclear Information System (INIS)

Leroy, Claude; Rancoita, Pier-Giorgio

2007-01-01

Silicon is used in radiation detectors and electronic devices. Nowadays, these devices achieving submicron technology are parts of integrated circuits of large to very large scale integration (VLSI). Silicon and silicon-based devices are commonly operated in many fields including particle physics experiments, nuclear medicine and space. Some of these fields present adverse radiation environments that may affect the operation of the devices. The particle energy deposition mechanisms by ionization and non-ionization processes are reviewed as well as the radiation-induced damage and its effect on device parameters evolution, depending on particle type, energy and fluence. The temporary or permanent damage inflicted by a single particle (single event effect) to electronic devices or integrated circuits is treated separately from the total ionizing dose (TID) effect for which the accumulated fluence causes degradation and from the displacement damage induced by the non-ionizing energy-loss (NIEL) deposition. Understanding of radiation effects on silicon devices has an impact on their design and allows the prediction of a specific device behaviour when exposed to a radiation field of interest

A Low-Power High-Speed Spintronics-Based Neuromorphic Computing System Using Real Time Tracking Method

DEFF Research Database (Denmark)

Farkhani, Hooman; Tohidi, Mohammad; Farkhani, Sadaf

2018-01-01

In spintronic-based neuromorphic computing systems (NCS), the switching of magnetic moment in a magnetic tunnel junction (MTJ) is used to mimic neuron firing. However, the stochastic switching behavior of the MTJ and process variations effect lead to a significant increase in stimulation time...... of such NCSs. Moreover, current NCSs need an extra phase to read the MTJ state after stimulation which is in contrast with real neuron functionality in human body. In this paper, the read circuit is replaced with a proposed real-time sensing (RTS) circuit. The RTS circuit tracks the MTJ state during...... stimulation phase. As soon as switching happens, the RTS circuit terminates the MTJ current and stimulates the post neuron. Hence, the RTS circuit not only improves the energy consumption and speed, but also makes the operation of NCS similar to real neuron functionality. The simulation results in 65-nm CMOS...

Utilizing an eye tracker device for operator support

NARCIS (Netherlands)

Greef, T.E. de; Lafeber, H.

2007-01-01

At present a number of studies have attempted to embed eye-tracking devices into closed-loop systems to augment the cognitive state of the human operator. It has been demonstrated that the pupil diameter and blinking frequency serve as such indicators. Although these two factors serve cognitive

Verification of electromagnetic effects from wireless devices in operating nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Ye, Song Hae; Kim, Young Sik; Lyou, Ho Sun; Kim, Min Suk [Korea Hydro and Nuclear Power Co. (KHNP), Central Research Institute, Daejeon (Korea, Republic of); Lyou, Joon [Dept. of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)

2015-10-15

Wireless communication technologies, especially smart phones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs) because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smart phones (Wi-Fi standard), Internet Protocol (IP) phones, personal digital assistant (PDA) for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs.

Verification of electromagnetic effects from wireless devices in operating nuclear power plants

Directory of Open Access Journals (Sweden)

Song-Hae Ye

2015-10-01

Full Text Available Wireless communication technologies, especially smartphones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smartphones (Wi-Fi standard, Internet Protocol (IP phones, personal digital assistant (PDA for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs.

Verification of electromagnetic effects from wireless devices in operating nuclear power plants

International Nuclear Information System (INIS)

Ye, Song Hae; Kim, Young Sik; Lyou, Ho Sun; Kim, Min Suk; Lyou, Joon

2015-01-01

Wireless communication technologies, especially smart phones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs) because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smart phones (Wi-Fi standard), Internet Protocol (IP) phones, personal digital assistant (PDA) for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs

Memory operation devices based on light-illumination ambipolar carbon-nanotube thin-film-transistors

International Nuclear Information System (INIS)

Aïssa, B.; Nedil, M.; Kroeger, J.; Haddad, T.; Rosei, F.

2015-01-01

We report the memory operation behavior of a light illumination ambipolar single-walled carbon nanotube thin film field-effect transistors devices. In addition to the high electronic-performance, such an on/off transistor-switching ratio of 10 4 and an on-conductance of 18 μS, these memory devices have shown a high retention time of both hole and electron-trapping modes, reaching 2.8 × 10 4  s at room temperature. The memory characteristics confirm that light illumination and electrical field can act as an independent programming/erasing operation method. This could be a fundamental step toward achieving high performance and stable operating nanoelectronic memory devices

Safety status system for operating room devices.

Science.gov (United States)

Guédon, Annetje C P; Wauben, Linda S G L; Overvelde, Marlies; Blok, Joleen H; van der Elst, Maarten; Dankelman, Jenny; van den Dobbelsteen, John J

2014-01-01

Since the increase of the number of technological aids in the operating room (OR), equipment-related incidents have come to be a common kind of adverse events. This underlines the importance of adequate equipment management to improve the safety in the OR. A system was developed to monitor the safety status (periodic maintenance and registered malfunctions) of OR devices and to facilitate the notification of malfunctions. The objective was to assess whether the system is suitable for use in an busy OR setting and to analyse its effect on the notification of malfunctions. The system checks automatically the safety status of OR devices through constant communication with the technical facility management system, informs the OR staff real-time and facilitates notification of malfunctions. The system was tested for a pilot period of six months in four ORs of a Dutch teaching hospital and 17 users were interviewed on the usability of the system. The users provided positive feedback on the usability. For 86.6% of total time, the localisation of OR devices was accurate. 62 malfunctions of OR devices were reported, an increase of 12 notifications compared to the previous year. The safety status system was suitable for an OR complex, both from a usability and technical point of view, and an increase of reported malfunctions was observed. The system eases monitoring the safety status of equipment and is a promising tool to improve the safety related to OR devices.

Integrated Spintronic Platforms for Biomolecular Recognition Detection

Science.gov (United States)

Martins, V. C.; Cardoso, F. A.; Loureiro, J.; Mercier, M.; Germano, J.; Cardoso, S.; Ferreira, R.; Fonseca, L. P.; Sousa, L.; Piedade, M. S.; Freitas, P. P.

2008-06-01

This paper covers recent developments in magnetoresistive based biochip platforms fabricated at INESC-MN, and their application to the detection and quantification of pathogenic waterborn microorganisms in water samples for human consumption. Such platforms are intended to give response to the increasing concern related to microbial contaminated water sources. The presented results concern the development of biological active DNA chips and protein chips and the demonstration of the detection capability of the present platforms. Two platforms are described, one including spintronic sensors only (spin-valve based or magnetic tunnel junction based), and the other, a fully scalable platform where each probe site consists of a MTJ in series with a thin film diode (TFD). Two microfluidic systems are described, for cell separation and concentration, and finally, the read out and control integrated electronics are described, allowing the realization of bioassays with a portable point of care unit. The present platforms already allow the detection of complementary biomolecular target recognition with 1 pM concentration.

Tailoring spin injection and magnetoresistance in ferromagnet/graphene junctions from first principles

Science.gov (United States)

Lazic, Predrag; Sipahi, Guilherme; Kawakami, Roland; Zutic, Igor

2013-03-01

Recent experimental advances in graphene suggest intriguing opportunities for novel spintronic applications which could significantly exceed the state-of-the art performance of their conventional charge-based counterparts. However, for reliable operation of such spintronic devices it is important to achieve an efficient spin injection and large magnetoresistive effects. We use the first principles calculations to guide the choice of a ferromagnetic region and its relative orientation to optimize the desired effects. We propose structures which could enable uniform spin injection, one of the key factors in implementing scalable spintronic circuits. Supported by NSF-NRI, SRC, ONR, Croatian Ministry of Science, Education, and Sports, and CCR at SUNY UB.

Stability of the superconductive operating mode in high current-density devices

International Nuclear Information System (INIS)

Wipf, S.L.

1979-01-01

The superconductive operating mode represents a thermal equilibrium that can tolerate a certain amount of disturbance before it is lost. The basin of attraction (BOA), in many ways equivalent to a potential well, is a measure of the size of disturbance needed to lift the device from the superconductive into a resistive operating mode. The BOA for a simple geometry is calculated and discussed. Experimental results are reported, showing how the concept is used to gain information on the disturbances occurring in a superconducting device

Towards nanoscale magnetic memory elements : fabrication and properties of sub - 100 nm magnetic tunnel junctions

NARCIS (Netherlands)

Fabrie, C.G.C.H.M.

2008-01-01

The rapidly growing field of spintronics has recently attracted much attention. Spintronics is electronics in which the spin degree of freedom has been added to conventional chargebased electronic devices. A magnetic tunnel junction (MTJ) is an example of a spintronic device. MTJs consist of two

Fabrication of spintronics device by direct synthesis of single-walled carbon nanotubes from ferromagnetic electrodes

Directory of Open Access Journals (Sweden)

Mohd Ambri Mohamed, Nobuhito Inami, Eiji Shikoh, Yoshiyuki Yamamoto, Hidenobu Hori and Akihiko Fujiwara

2008-01-01

Full Text Available We describe an alternative method for realizing a carbon nanotube spin field-effect transistor device by the direct synthesis of single-walled carbon nanotubes (SWNTs on substrates by alcohol catalytic chemical vapor deposition. We observed hysteretic magnetoresistance (MR at low temperatures due to spin-dependent transport. In these devices, the maximum ratio in resistance variation of MR was found to be 1.8%.

Memory operation devices based on light-illumination ambipolar carbon-nanotube thin-film-transistors

Energy Technology Data Exchange (ETDEWEB)

Aïssa, B., E-mail: aissab@emt.inrs.ca [Qatar Environment and Energy Research Institute (QEERI), Qatar Foundation, P.O. Box 5825, Doha (Qatar); Centre Energie, Matériaux et Télécommunications, INRS, 1650, Boulevard Lionel-Boulet Varennes, Quebec J3X 1S2 (Canada); Nedil, M. [Telebec Wireless Underground Communication Laboratory, UQAT, 675, 1ère Avenue, Val d' Or, Quebec J9P 1Y3 (Canada); Kroeger, J. [NanoIntegris & Raymor Nanotech, Raymor Industries Inc., 3765 La Vérendrye, Boisbriand, Quebec J7H 1R8 (Canada); Haddad, T. [Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0B8 (Canada); Rosei, F. [Centre Energie, Matériaux et Télécommunications, INRS, 1650, Boulevard Lionel-Boulet Varennes, Quebec J3X 1S2 (Canada)

2015-09-28

We report the memory operation behavior of a light illumination ambipolar single-walled carbon nanotube thin film field-effect transistors devices. In addition to the high electronic-performance, such an on/off transistor-switching ratio of 10{sup 4} and an on-conductance of 18 μS, these memory devices have shown a high retention time of both hole and electron-trapping modes, reaching 2.8 × 10{sup 4} s at room temperature. The memory characteristics confirm that light illumination and electrical field can act as an independent programming/erasing operation method. This could be a fundamental step toward achieving high performance and stable operating nanoelectronic memory devices.

Operation method and operation control device for emergency core cooling system

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Shoichiro; Takahashi, Toshiyuki; Fujii, Tadashi [Hitachi Ltd., Tokyo (Japan); Mizutani, Akira

1996-05-07

The present invention provides a method of reducing continuous load capacity of an emergency cooling system of a BWR type reactor and a device reducing a rated capacity of an emergency power source facility. Namely, the emergency core cooling system comprises a first cooling system having a plurality of power source systems based on a plurality of emergency power sources and a second cooling system having a remaining heat removing function. In this case, when the first cooling system is operated the manual starting under a predetermined condition that an external power source loss event should occur, a power source division different from the first cooling system shares the operation to operate the secondary cooling system simultaneously. Further, the first cooling system is constituted as a high pressure reactor core water injection system and the second cooling system is constituted as a remaining heat removing system. With such a constitution, a high pressure reactor core water injection system for manual starting and a remaining heat removing system of different power source division can be operated simultaneously before automatic operation of the emergency core cooling system upon loss of external power source of a nuclear power plant. (I.S.)

Mobile Augmented Note-taking to Support Operating Physical Devices

OpenAIRE

Liu , Can; Diehl , Jonathan; Huot , Stéphane; Borchers , Jan

2011-01-01

Mobile Augmented Reality: Design Issues and Opportunities - 1st Workshop on Mobile Augmented Reality, MobileHCI 2011; In this paper we propose an approach to assist operating physical devices with mobile augmented reality techniques. We propose ideas of interaction techniques, which allow users to put self-authored information as notes onto physical objects. We present the design of two example applications aiming at solving problems from different aspects of physical operations.

Progress in Group III nitride semiconductor electronic devices

International Nuclear Information System (INIS)

Hao Yue; Zhang Jinfeng; Shen Bo; Liu Xinyu

2012-01-01

Recently there has been a rapid domestic development in group III nitride semiconductor electronic materials and devices. This paper reviews the important progress in GaN-based wide bandgap microelectronic materials and devices in the Key Program of the National Natural Science Foundation of China, which focuses on the research of the fundamental physical mechanisms of group III nitride semiconductor electronic materials and devices with the aim to enhance the crystal quality and electric performance of GaN-based electronic materials, develop new GaN heterostructures, and eventually achieve high performance GaN microwave power devices. Some remarkable progresses achieved in the program will be introduced, including those in GaN high electron mobility transistors (HEMTs) and metal—oxide—semiconductor high electron mobility transistors (MOSHEMTs) with novel high-k gate insulators, and material growth, defect analysis and material properties of InAlN/GaN heterostructures and HEMT fabrication, and quantum transport and spintronic properties of GaN-based heterostructures, and high-electric-field electron transport properties of GaN material and GaN Gunn devices used in terahertz sources. (invited papers)

Room temperature electrically tunable rectification magnetoresistance in Ge-based Schottky devices.

Science.gov (United States)

Huang, Qi-Kun; Yan, Yi; Zhang, Kun; Li, Huan-Huan; Kang, Shishou; Tian, Yu-Feng

2016-11-23

Electrical control of magnetotransport properties is crucial for device applications in the field of spintronics. In this work, as an extension of our previous observation of rectification magnetoresistance, an innovative technique for electrical control of rectification magnetoresistance has been developed by applying direct current and alternating current simultaneously to the Ge-based Schottky devices, where the rectification magnetoresistance could be remarkably tuned in a wide range. Moreover, the interface and bulk contribution to the magnetotransport properties has been effectively separated based on the rectification magnetoresistance effect. The state-of-the-art electrical manipulation technique could be adapt to other similar heterojunctions, where fascinating rectification magnetoresistance is worthy of expectation.

Mitigating operating room fires: development of a carbon dioxide fire prevention device.

Science.gov (United States)

Culp, William C; Kimbrough, Bradly A; Luna, Sarah; Maguddayao, Aris J

2014-04-01

Operating room fires are sentinel events that present a real danger to surgical patients and occur at least as frequently as wrong-sided surgery. For fire to occur, the 3 points of the fire triad must be present: an oxidizer, an ignition source, and fuel source. The electrosurgical unit (ESU) pencil triggers most operating room fires. Carbon dioxide (CO2) is a gas that prevents ignition and suppresses fire by displacing oxygen. We hypothesize that a device can be created to reduce operating room fires by generating a cone of CO2 around the ESU pencil tip. One such device was created by fabricating a divergent nozzle and connecting it to a CO2 source. This device was then placed over the ESU pencil, allowing the tip to be encased in a cone of CO2 gas. The device was then tested in 21%, 50%, and 100% oxygen environments. The ESU was activated at 50 W cut mode while placing the ESU pencil tip on a laparotomy sponge resting on an aluminum test plate for up to 30 seconds or until the sponge ignited. High-speed videography was used to identify time of ignition. Each test was performed in each oxygen environment 5 times with the device activated (CO2 flow 8 L/min) and with the device deactivated (no CO2 flow-control). In addition, 3-dimensional spatial mapping of CO2 concentrations was performed with a CO2 sampling device. The median ± SD [range] ignition time of the control group in 21% oxygen was 2.9 s ± 0.44 [2.3-3.0], in 50% oxygen 0.58 s ± 0.12 [0.47-0.73], and in 100% oxygen 0.48 s ± 0.50 [0.03-1.27]. Fires were ignited with each control trial (15/15); no fires ignited when the device was used (0/15, P fire prevention device can be created by using a divergent nozzle design through which CO2 passes, creating a cone of fire suppressant. This device as demonstrated in a flammability model effectively reduced the risk of fire. CO2 3-dimensional spatial mapping suggests effective fire reduction at least 1 cm away from the tip of the ESU pencil at 8 L/min CO2 flow

Monopole and topological electron dynamics in adiabatic spintronic and graphene systems

International Nuclear Information System (INIS)

Tan, S.G.; Jalil, M.B.A.; Fujita, T.

2010-01-01

A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin's fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.

GNSS-based operational monitoring devices for forest logging operation chains

Directory of Open Access Journals (Sweden)

Raimondo Gallo

2013-09-01

Full Text Available The first results of a new approach for implementing operational monitoring tool to control the performance of forest mechanisation chains are proposed and discussed. The solution is based on Global Navigation Satellite System (GNSS tools that are the core of a datalogging system that, in combination with a specific inference-engine, is able to analyse process times, work distances, forward speeds, vehicle tracking and number of working cycles in forest operations. As a consequence the operational monitoring control methods could provide an evaluation of the efficiency of the investigated forest operations. The study has monitored the performance of a tower yarder with crane and processor-head, during logging operations. The field surveys consisted on the installation of the GNSS device directly on the forest equipment for monitoring its movements. Simultaneously the field survey considered the integration of the GNSS information with a time study of work elements based on the continuous time methods supported by a time study board. Additionally, where possible, the onboard computer of the forest machine was also used in order to obtain additional information to be integrated to the GNSS data and the time study. All the recorded GNSS data integrated with the work elements study were thus post-processed through GIS analysis. The preliminary overview about the application of this approach on harvesting operations has permitted to assess a good feasibility of the use of GNSS in the relief of operative times in high mechanised forest chains. Results showed an easy and complete identification of the different operative cycles and elementary operations phases, with a maximum difference between the two methodologies of 10.32%. The use of GNSS installed on forest equipment, integrated with the inferenceengine and also with an interface for data communication or data storage, will permit an automatic or semi-automatic operational monitoring, improving

Measurement of Underwater Operational Noise Emitted by Wave and Tidal Stream Energy Devices.

Science.gov (United States)

Lepper, Paul A; Robinson, Stephen P

2016-01-01

The increasing international growth in the development of marine and freshwater wave and tidal energy harvesting systems has been followed by a growing requirement to understand any associated underwater impact. Radiated noise generated during operation is dependent on the device's physical properties, the sound-propagation environment, and the device's operational state. Physical properties may include size, distribution in the water column, and mechanics/hydrodynamics. The sound-propagation environment may be influenced by water depth, bathymetry, sediment type, and water column acoustic properties, and operational state may be influenced by tidal cycle and wave height among others This paper discusses some of the challenges for measurement of noise characteristics from these devices as well as a case study of the measurement of radiated noise from a full-scale wave energy converter.

Fabrication of hybrid molecular devices using multi-layer graphene break junctions

Science.gov (United States)

Island, J. O.; Holovchenko, A.; Koole, M.; Alkemade, P. F. A.; Menelaou, M.; Aliaga-Alcalde, N.; Burzurí, E.; van der Zant, H. S. J.

2014-11-01

We report on the fabrication of hybrid molecular devices employing multi-layer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.

Control and manipulation of antiferromagnetic skyrmions in racetrack

Science.gov (United States)

Xia, Haiyan; Jin, Chendong; Song, Chengkun; Wang, Jinshuai; Wang, Jianbo; Liu, Qingfang

2017-12-01

Controllable manipulations of magnetic skyrmions are essential for next-generation spintronic devices. Here, the duplication and merging of skyrmions, as well as logical AND and OR functions, are designed in antiferromagnetic (AFM) materials with a cusp or smooth Y-junction structures. The operational time are in the dozens of picoseconds, enabling ultrafast information processing. A key factor for the successful operation is the relatively complex Y-junction structures, where domain walls propagate through in a controlled manner, without significant risks of pinning, vanishing or unwanted depinning of existing domain walls, as well as the nucleation of new domain walls. The motions of a multi-bit, namely the motion of an AFM skyrmion-chain in racetrack, are also investigated. Those micromagnetic simulations may contribute to future AFM skyrmion-based spintronic devices, such as nanotrack memory, logic gates and other information processes.

Manipulating spin in organic spintronics : probing the interplay between the electronic and nuclear spins in organic semiconductors

NARCIS (Netherlands)

Bobbert, P.A.

2014-01-01

The growing interest in spin manipulation in the field of spin electronics, or "spintronics," is due to the wealth of exciting possibilities that it offers in areas of magnetic sensing, new types of information storage, low-power electronics, and quantum information processing. Nuclear spin

Organic Light-Emitting Transistors: Materials, Device Configurations, and Operations.

Science.gov (United States)

Zhang, Congcong; Chen, Penglei; Hu, Wenping

2016-03-09

Organic light-emitting transistors (OLETs) represent an emerging class of organic optoelectronic devices, wherein the electrical switching capability of organic field-effect transistors (OFETs) and the light-generation capability of organic light-emitting diodes (OLEDs) are inherently incorporated in a single device. In contrast to conventional OFETs and OLEDs, the planar device geometry and the versatile multifunctional nature of OLETs not only endow them with numerous technological opportunities in the frontier fields of highly integrated organic electronics, but also render them ideal scientific scaffolds to address the fundamental physical events of organic semiconductors and devices. This review article summarizes the recent advancements on OLETs in light of materials, device configurations, operation conditions, etc. Diverse state-of-the-art protocols, including bulk heterojunction, layered heterojunction and laterally arranged heterojunction structures, as well as asymmetric source-drain electrodes, and innovative dielectric layers, which have been developed for the construction of qualified OLETs and for shedding new and deep light on the working principles of OLETs, are highlighted by addressing representative paradigms. This review intends to provide readers with a deeper understanding of the design of future OLETs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spin transport and spin torque in antiferromagnetic devices

Science.gov (United States)

Železný, J.; Wadley, P.; Olejník, K.; Hoffmann, A.; Ohno, H.

2018-03-01

Ferromagnets are key materials for sensing and memory applications. In contrast, antiferromagnets, which represent the more common form of magnetically ordered materials, have found less practical application beyond their use for establishing reference magnetic orientations via exchange bias. This might change in the future due to the recent progress in materials research and discoveries of antiferromagnetic spintronic phenomena suitable for device applications. Experimental demonstration of the electrical switching and detection of the Néel order open a route towards memory devices based on antiferromagnets. Apart from the radiation and magnetic-field hardness, memory cells fabricated from antiferromagnets can be inherently multilevel, which could be used for neuromorphic computing. Switching speeds attainable in antiferromagnets far exceed those of ferromagnetic and semiconductor memory technologies. Here, we review the recent progress in electronic spin-transport and spin-torque phenomena in antiferromagnets that are dominantly of the relativistic quantum-mechanical origin. We discuss their utility in pure antiferromagnetic or hybrid ferromagnetic/antiferromagnetic memory devices.

CT pre-operative planning of a new semi-implantable bone conduction hearing device

Energy Technology Data Exchange (ETDEWEB)

Law, Eric K.C.; Bhatia, Kunwar S.S. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Hong Kong, SAR (China); Tsang, Willis S.S.; Tong, Michael C.F. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Otorhinolaryngology, Head and Neck Surgery, Hong Kong, SAR (China); Shi, Lin [The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Hong Kong, SAR (China); The Chinese University of Hong Kong, Chow Yuk Ho Technology Center for Innovative Medicine, Hong Kong, SAR (China)

2016-06-15

Accommodating a novel semi-implantable bone conduction hearing device within the temporal bone presents challenges for surgical planning. This study describes the utility of CT in pre-operative assessment of such an implant. Retrospective review of pre-operative CT, clinical and surgical records of 16 adults considered for device implantation. Radiological suitability was assessed on CT using 3D simulation software. Antero-posterior (AP) dimensions of the mastoid bone and minimum skull thickness were measured. CT planning results were correlated with operative records. Eight and five candidates were suitable for device placement in the transmastoid and retrosigmoid positions, respectively, and three were radiologically unsuitable. The mean AP diameter of the mastoid cavity was 14.6 mm for the transmastoid group and 4.6 mm for the retrosigmoid group (p < 0.05). Contracted mastoid and/or prior surgery were predisposing factors for unsuitability. Four transmastoid and five retrosigmoid positions required sigmoid sinus/dural depression and/or use of lifts due to insufficient bone capacity. A high proportion of patients being considered have contracted or operated mastoids, which reduces the feasibility of the transmastoid approach. This finding combined with the complex temporal bone geometry illustrates the importance of careful CT evaluation using 3D software for precise device simulation. (orig.)

Operation control device for a nuclear reactor fuel exchanger

International Nuclear Information System (INIS)

Aida, Takashi.

1984-01-01

Purpose: To provide a operation control device for a nuclear reactor fuel exchanger with reduced size and weight capable of optionally meeting the complicated and versatile mode of the operation scope. Constitution: The operation range of a fuel exchanger is finely divided so as to attain the state capable of discriminating between operation-allowable range and operation-inhibitive range, which are stored in a memory circuit. Upon operating the fuel exchanger, the position is detected and a divided range data corresponding to the present position is taken out from the memory circuit so as to determine whether the fuel exchanger is to be run or stopped. Use of reduced size and compact IC circuits (calculation circuit, memory circuit, data latch circuit) and input/output interface circuits or the likes contributes to the size reduction of the exchanger control system to enlarge the floor maintenance space. (Moriyama, K.)

Strong interfacial exchange field in the graphene/EuS heterostructure

NARCIS (Netherlands)

Wei, Peng; Lee, Sunwoo; Lemaitre, Florian; Pinel, Lucas; Cutaia, Davide; Cha, Wujoon; Katmis, Ferhat; Zhu, Yu; Heiman, Donald; Hone, James; Moodera, Jagadeesh S.; Chen, Ching Tzu

2016-01-01

Exploiting 2D materials for spintronic applications can potentially realize next-generation devices featuring low power consumption and quantum operation capability. The magnetic exchange field (MEF) induced by an adjacent magnetic insulator enables efficient control of local spin generation and

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Science.gov (United States)

2010-10-01

... devices operating in the 608-614 MHz band. For a wireless medical telemetry device operating within the... 47 Telecommunication 5 2010-10-01 2010-10-01 false Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band. 95.1119 Section 95.1119 Telecommunication FEDERAL...

Novel spintronics devices for memory and logic: prospects and challenges for room temperature all spin computing

Science.gov (United States)

Wang, Jian-Ping

An energy efficient memory and logic device for the post-CMOS era has been the goal of a variety of research fields. The limits of scaling, which we expect to reach by the year 2025, demand that future advances in computational power will not be realized from ever-shrinking device sizes, but rather by innovative designs and new materials and physics. Magnetoresistive based devices have been a promising candidate for future integrated magnetic computation because of its unique non-volatility and functionalities. The application of perpendicular magnetic anisotropy for potential STT-RAM application was demonstrated and later has been intensively investigated by both academia and industry groups, but there is no clear path way how scaling will eventually work for both memory and logic applications. One of main reasons is that there is no demonstrated material stack candidate that could lead to a scaling scheme down to sub 10 nm. Another challenge for the usage of magnetoresistive based devices for logic application is its available switching speed and writing energy. Although a good progress has been made to demonstrate the fast switching of a thermally stable magnetic tunnel junction (MTJ) down to 165 ps, it is still several times slower than its CMOS counterpart. In this talk, I will review the recent progress by my research group and my C-SPIN colleagues, then discuss the opportunities, challenges and some potential path ways for magnetoresitive based devices for memory and logic applications and their integration for room temperature all spin computing system.

Devices and methods of operation thereof for providing stable flow for centrifugal compressors

Science.gov (United States)

Skoch, Gary J. (Inventor); Stevens, Mark A. (Inventor); Jett, Thomas A. (Inventor)

2008-01-01

Centrifugal compressor flow stabilizing devices and methods of operation thereof are disclosed that act upon the flow field discharging from the impeller of a centrifugal compressor and modify the flow field ahead of the diffuser vanes such that flow conditions contributing to rotating stall and surge are reduced or even eliminated. In some embodiments, shaped rods and methods of operation thereof are disclosed, whereas in other embodiments reverse-tangent air injection devices and methods are disclosed.

Operating Systems for Low-End Devices in the Internet of Things: a Survey

OpenAIRE

Hahm , Oliver; Baccelli , Emmanuel; Petersen , Hauke; Tsiftes , Nicolas

2016-01-01

International audience; The Internet of Things (IoT) is projected to soon interconnect tens of billions of new devices, in large part also connected to the Internet. IoT devices include both high-end devices which can use traditional go-to operating systems (OS) such as Linux, and low-end devices which cannot, due to stringent resource constraints, e.g. very limited memory, computational power, and power supply. However, large-scale IoT software development, deployment, and maintenance requir...

Space weather impact on radio device operation

Directory of Open Access Journals (Sweden)

Berngardt O.I.

2017-09-01

Full Text Available This paper reviews the space weather impact on operation of radio devices. The review is based on recently published papers, books, and strategic scientific plans of space weather investigations. The main attention is paid to ionospheric effects on propagation of radiowaves, basically short ones. Some examples of such effects are based on 2012–2016 ISTP SB RAS EKB radar data: attenuation of ground backscatter signals during solar flares, effects of traveling ionospheric disturbances of different scales in ground backscatter signals, effects of magnetospheric waves in ionospheric scatter signals.

Space weather impact on radio device operation

Science.gov (United States)

Berngardt, Oleg

2017-09-01

This paper reviews the space weather impact on operation of radio devices. The review is based on recently published papers, books, and strategic scientific plans of space weather investigations. The main attention is paid to ionospheric effects on propagation of radiowaves, basically short ones. Some examples of such effects are based on 2012–2016 ISTP SB RAS EKB radar data: attenuation of ground backscatter signals during solar flares, effects of traveling ionospheric disturbances of different scales in ground backscatter signals, effects of magnetospheric waves in ionospheric scatter signals.

Investigation of surge protective devices operation of a wind generator

International Nuclear Information System (INIS)

Dimitrov, D.; Vasileva, M.

2008-01-01

The interest to the investments in a wind energetics increases in the last years. The wind energetics is the fastest developing direction in the energetics in global scale. The wind energy is more attractive because its prices are lower in comparison of the other technologies for generating energy. The right choice of the surge protective devices has the important meaning on building and exploitation of the wind generators. The aim of this paper is investigation of the surge protective devices operation when they are installation to a wind generator. (authors)

Point of Maintenance Ruggedized Operational Device Evaluation and Observation Test Report

National Research Council Canada - National Science Library

Gorman, Megan

2002-01-01

.... The Ruggedized Operational Device Evaluation and Observation (RODEO) test examined hardware packaging, software user interface, and environmental factors associated with the usability of potential Point of Maintenance (POMx) electronic tools...

Closed-loop approach for situation awareness of medical devices and operating room infrastructure

Directory of Open Access Journals (Sweden)

Rockstroh Max

2015-09-01

Full Text Available In recent years, approaches for information and control integration in the digital operating room have emerged. A major step towards an intelligent operating room and a cooperative technical environment would be autonomous adaptation of medical devices and systems to the surgical workflow. The OR staff should be freed from information seeking and maintenance tasks. We propose a closed-loop concept integrating workflow monitoring, processing and (semi-automatic interaction to bridge the gap between OR integration of medical devices and workflow-related information management.

Electron spin for classical information processing: a brief survey of spin-based logic devices, gates and circuits

International Nuclear Information System (INIS)

Bandyopadhyay, Supriyo; Cahay, Marc

2009-01-01

In electronics, information has been traditionally stored, processed and communicated using an electron's charge. This paradigm is increasingly turning out to be energy-inefficient, because movement of charge within an information processing device invariably causes current flow and an associated dissipation. Replacing 'charge' with the 'spin' of an electron to encode information may eliminate much of this dissipation and lead to more energy-efficient 'green electronics'. This realization has spurred significant research in spintronic devices and circuits where spin either directly acts as the physical variable for hosting information or augments the role of charge. In this review article, we discuss and elucidate some of these ideas, and highlight their strengths and weaknesses. Many of them can potentially reduce energy dissipation significantly, but unfortunately are error-prone and unreliable. Moreover, there are serious obstacles to their technological implementation that may be difficult to overcome in the near term. This review addresses three constructs: (1) single devices or binary switches that can be constituents of Boolean logic gates for digital information processing, (2) complete gates that are capable of performing specific Boolean logic operations, and (3) combinational circuits or architectures (equivalent to many gates working in unison) that are capable of performing universal computation. (topical review)

A versatile LabVIEW and field-programmable gate array-based scanning probe microscope for in operando electronic device characterization.

Science.gov (United States)

Berger, Andrew J; Page, Michael R; Jacob, Jan; Young, Justin R; Lewis, Jim; Wenzel, Lothar; Bhallamudi, Vidya P; Johnston-Halperin, Ezekiel; Pelekhov, Denis V; Hammel, P Chris

2014-12-01

Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In operando characterization of such devices by scanning probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanning probe microscope (SPM) which is capable of both standard force imaging (atomic, magnetic, electrostatic) and simultaneous electrical transport measurements. We utilize flexible and inexpensive FPGA (field-programmable gate array) hardware and a custom software framework developed in National Instrument's LabVIEW environment to perform the various aspects of microscope operation and device measurement. The FPGA-based approach enables sensitive, real-time cantilever frequency-shift detection. Using this system, we demonstrate electrostatic force microscopy of an electrically biased graphene field-effect transistor device. The combination of SPM and electrical transport also enables imaging of the transport response to a localized perturbation provided by the scanned cantilever tip. Facilitated by the broad presence of LabVIEW in the experimental sciences and the openness of our software solution, our system permits a wide variety of combined scanning and transport measurements by providing standardized interfaces and flexible access to all aspects of a measurement (input and output signals, and processed data). Our system also enables precise control of timing (synchronization of scanning and transport operations) and implementation of sophisticated feedback protocols, and thus should be broadly interesting and useful to practitioners in the field.

Process automation system for integration and operation of Large Volume Plasma Device

International Nuclear Information System (INIS)

Sugandhi, R.; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

2016-01-01

Highlights: • Analysis and design of process automation system for Large Volume Plasma Device (LVPD). • Data flow modeling for process model development. • Modbus based data communication and interfacing. • Interface software development for subsystem control in LabVIEW. - Abstract: Large Volume Plasma Device (LVPD) has been successfully contributing towards understanding of the plasma turbulence driven by Electron Temperature Gradient (ETG), considered as a major contributor for the plasma loss in the fusion devices. Large size of the device imposes certain difficulties in the operation, such as access of the diagnostics, manual control of subsystems and large number of signals monitoring etc. To achieve integrated operation of the machine, automation is essential for the enhanced performance and operational efficiency. Recently, the machine is undergoing major upgradation for the new physics experiments. The new operation and control system consists of following: (1) PXIe based fast data acquisition system for the equipped diagnostics; (2) Modbus based Process Automation System (PAS) for the subsystem controls and (3) Data Utilization System (DUS) for efficient storage, processing and retrieval of the acquired data. In the ongoing development, data flow model of the machine’s operation has been developed. As a proof of concept, following two subsystems have been successfully integrated: (1) Filament Power Supply (FPS) for the heating of W- filaments based plasma source and (2) Probe Positioning System (PPS) for control of 12 number of linear probe drives for a travel length of 100 cm. The process model of the vacuum production system has been prepared and validated against acquired pressure data. In the next upgrade, all the subsystems of the machine will be integrated in a systematic manner. The automation backbone is based on 4-wire multi-drop serial interface (RS485) using Modbus communication protocol. Software is developed on LabVIEW platform using

Process automation system for integration and operation of Large Volume Plasma Device

Energy Technology Data Exchange (ETDEWEB)

Sugandhi, R., E-mail: ritesh@ipr.res.in; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

2016-11-15

Highlights: • Analysis and design of process automation system for Large Volume Plasma Device (LVPD). • Data flow modeling for process model development. • Modbus based data communication and interfacing. • Interface software development for subsystem control in LabVIEW. - Abstract: Large Volume Plasma Device (LVPD) has been successfully contributing towards understanding of the plasma turbulence driven by Electron Temperature Gradient (ETG), considered as a major contributor for the plasma loss in the fusion devices. Large size of the device imposes certain difficulties in the operation, such as access of the diagnostics, manual control of subsystems and large number of signals monitoring etc. To achieve integrated operation of the machine, automation is essential for the enhanced performance and operational efficiency. Recently, the machine is undergoing major upgradation for the new physics experiments. The new operation and control system consists of following: (1) PXIe based fast data acquisition system for the equipped diagnostics; (2) Modbus based Process Automation System (PAS) for the subsystem controls and (3) Data Utilization System (DUS) for efficient storage, processing and retrieval of the acquired data. In the ongoing development, data flow model of the machine’s operation has been developed. As a proof of concept, following two subsystems have been successfully integrated: (1) Filament Power Supply (FPS) for the heating of W- filaments based plasma source and (2) Probe Positioning System (PPS) for control of 12 number of linear probe drives for a travel length of 100 cm. The process model of the vacuum production system has been prepared and validated against acquired pressure data. In the next upgrade, all the subsystems of the machine will be integrated in a systematic manner. The automation backbone is based on 4-wire multi-drop serial interface (RS485) using Modbus communication protocol. Software is developed on LabVIEW platform using

High and tunable spin current induced by magnetic-electric fields in a single-mode spintronic device

International Nuclear Information System (INIS)

Bala Kumar, S; Jalil, M B A; Tan, S G; Liang, G-C

2009-01-01

We proposed that a viable form of spin current transistor is one to be made from a single-mode device which passes electrons through a series of magnetic-electric barriers built into the device. The barriers assume a wavy spatial profile across the conduction path due to the inevitable broadening of the magnetic fields. Field broadening results in a linearly increasing vector potential across the conduction channel, which increases spin polarization. We have identified that the important factors for generating high spin polarization and conductance modulation are the low source-drain bias, the broadened magnetic fields, and the high number of FM gates within a fixed channel length.

Efficient spin-filtering, magnetoresistance and negative differential resistance effects of a one-dimensional single-molecule magnet Mn(dmit2-based device with graphene nanoribbon electrodes

Directory of Open Access Journals (Sweden)

N. Liu

2017-12-01

Full Text Available We present first-principle spin-dependent quantum transport calculations in a molecular device constructed by one single-molecule magnet Mn(dmit2 and two graphene nanoribbon electrodes. Our results show that the device could generate perfect spin-filtering performance in a certain bias range both in the parallel configuration (PC and the antiparallel configuration (APC. At the same time, a magnetoresistance effect, up to a high value of 103%, can be realized. Moreover, visible negative differential resistance phenomenon is obtained for the spin-up current of the PC. These results suggest that our one-dimensional molecular device is a promising candidate for multi-functional spintronics devices.

Mobile devices in the operating rooms: intended and unintended consequences for nurses’ work

NARCIS (Netherlands)

Sergeeva, A.; Aij, K.H.; van den Hooff, B.J.; Huysman, M.H.

2016-01-01

This article reports the results of a case study of the consequences of mobile device use for the work practices of operating room nurses. The study identifies different patterns of mobile technology use by operating room nurses, including both work-related and non-work-related use. These patterns

Reusable single-port access device shortens operative time and reduces operative costs.

Science.gov (United States)

Shussman, Noam; Kedar, Asaf; Elazary, Ram; Abu Gazala, Mahmoud; Rivkind, Avraham I; Mintz, Yoav

2014-06-01

In recent years, single-port laparoscopy (SPL) has become an attractive approach for performing surgical procedures. The pitfalls of this approach are technical and financial. Financial concerns are due to the increased cost of dedicated devices and prolonged operating room time. Our aim was to calculate the cost of SPL using a reusable port and instruments in order to evaluate the cost difference between this approach to SPL using the available disposable ports and standard laparoscopy. We performed 22 laparoscopic procedures via the SPL approach using a reusable single-port access system and reusable laparoscopic instruments. These included 17 cholecystectomies and five other procedures. Operative time, postoperative length of stay (LOS) and complications were prospectively recorded and were compared with similar data from our SPL database. Student's t test was used for statistical analysis. SPL was successfully performed in all cases. Mean operative time for cholecystectomy was 72 min (range 40-116). Postoperative LOS was not changed from our standard protocols and was 1.1 days for cholecystectomy. The postoperative course was within normal limits for all patients and perioperative morbidity was recorded. Both operative time and length of hospital stay were shorter for the 17 patients who underwent cholecystectomy using a reusable port than for the matched previous 17 SPL cholecystectomies we performed (p cost difference. Operating with a reusable port ended up with an average cost savings of US$388 compared with using disposable ports, and US$240 compared with standard laparoscopy. Single-port laparoscopic surgery is a technically challenging and expensive surgical approach. Financial concerns among others have been advocated against this approach; however, we demonstrate herein that using a reusable port and instruments reduces operative time and overall operative costs, even beyond the cost of standard laparoscopy.

Optical devices for proximity operations study and test report. [intensifying images for visual observation during space transportation system activities

Science.gov (United States)

Smith, R. A.

1979-01-01

Operational and physical requirements were investigated for a low-light-level viewing device to be used as a window-mounted optical sight for crew use in the pointing, navigating, stationkeeping, and docking of space vehicles to support space station operations and the assembly of large structures in space. A suitable prototype, obtained from a commercial vendor, was subjected to limited tests to determine the potential effectiveness of a proximity optical device in spacecraft operations. The constructional features of the device are discussed as well as concepts for its use. Tests results show that a proximity optical device is capable of performing low-light-level viewing services and will enhance manned spacecraft operations.

Energy management in mobile devices with the cinder operating system

KAUST Repository

Roy, Arjun

2011-01-01

We argue that controlling energy allocation is an increasingly useful and important feature for operating systems, especially on mobile devices. We present two new low-level abstractions in the Cinder operating system, reserves and taps, which store and distribute energy for application use. We identify three key properties of control - isolation, delegation, and subdivision - and show how using these abstractions can achieve them. We also show how the architecture of the HiStar information-flow control kernel lends itself well to energy control. We prototype and evaluate Cinder on a popular smartphone, the Android G1. Copyright © 2011 ACM.

Prediction of Operating Characteristics of Electrotechnical Devices using Artificial Neural Networks

Directory of Open Access Journals (Sweden)

PASCA Alexandra

2014-05-01

Full Text Available The paper purpose is to emphasize the possibilities and the advantages to use the artificial intelligence techniques for operating mode prediction of electrotechnical devices. The considered application consists of the analysis of behavior of an inductive proximity sensor at variation of design parameters.

Improvements in or relating to fluid operated devices for moving articles

International Nuclear Information System (INIS)

Rogerson, Victor.

1986-01-01

The patent relates to fluid operated devices for moving articles. The machine may be used in filling a nuclear fuel canister with fuel pellets where there is a tendency for out of squareness of pellets to produce a jam condition readily cleared by a modest force. (U.K.)

Efficient Spin Injection into Semiconductor

International Nuclear Information System (INIS)

Nahid, M.A.I.

2010-06-01

Spintronic research has made tremendous progress nowadays for making future devices obtain extra advantages of low power, and faster and higher scalability compared to present electronic devices. A spintronic device is based on the transport of an electron's spin instead of charge. Efficient spin injection is one of the very important requirements for future spintronic devices. However, the effective spin injection is an exceedingly difficult task. In this paper, the importance of spin injection, basics of spin current and the essential requirements of spin injection are illustrated. The experimental technique of electrical spin injection into semiconductor is also discussed based on the experimental experience. The electrical spin injection can easily be implemented for spin injection into any semiconductor. (author)

Liquid electrolyte positioning along the device channel influences the operation of Organic Electro-Chemical Transistors

KAUST Repository

D'angelo, Pasquale

2014-11-01

In this work, we show the influence of the liquid electrolyte adsorption by porous films made of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), PEDOT:PSS, on the operation of an Organic Electro-Chemical Transistor with an active channel based on these polymeric films. In particular, the effect of film hydration on device performance is evaluated by studying its electrical response as a function of the spatial position between the electrolyte and the channel electrodes. This is done by depositing a PEDOT:PSS film on a super-hydrophobic surface aimed at controlling the electrolyte confinement next to the electrodes. The device response shows that the confinement of ionic liquids near to the drain electrode results in a worsening of the current modulation. This result has been interpreted in the light of studies dealing with the transport of ions in semiconducting polymers, indicating that the electrolyte adsorption by the polymeric film implies the formation of liquid pathways inside its bulk. These pathways, in particular, affect the device response because they are able to assist the drift of ionic species in the electrolyte towards the drain electrode. The effect of electrolyte adsorption on the device operation is confirmed by means of moving-front measurements, and is related to the reproducibility of the device operation curves by measuring repeatedly its electrical response.

Operation guide device

International Nuclear Information System (INIS)

Oohashi, Hideaki.

1982-01-01

Purpose: To enable a reactor operator to perform safety and sure inspection for a reactor and take manual start-up operations for the necessary systems at optimum timing with neither misoperation nor misjudging after the occurrence of reactor accidents. Constitution: If a signal judging circuit judges the generation of an accident signal for a reactor, the circuit issues an output signal to start the time counting operation of a time counter thereby inform the elapse of time after the occurrence of the reactor accident. Further, a time signal generated on every predetermined time from the time counter and a process signal indicating the reactor status are logically judged and, if the conditions for taking manual start-up operations, are satisfied, a start-up instruction signal is generated. An information signal is formed depending on the start-up instruction and the content of the start-up instruction is displayed on every predetermined time by the information signal, whereby the operator can perform the manual start-up operations at the optimum timings. (Moriyama, K.)

47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

Science.gov (United States)

2010-10-01

... wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the critical... 47 Telecommunication 5 2010-10-01 2010-10-01 false Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. 95.1121 Section 95.1121...

40 CFR 63.3546 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.3546 Section 63.3546... device or system of multiple capture devices. The average duct static pressure is the maximum operating... Add-on Controls Option § 63.3546 How do I establish the emission capture system and add-on control...

Optimal Operation and Dispatch of Voltage Regulation Devices Considering High Penetrations of Distributed Photovoltaic Generation

Energy Technology Data Exchange (ETDEWEB)

Mather, Barry A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cho, Gyu-Jung [Sungkyunkwan University; Oh, Yun-Sik [Sungkyunkwan University; Kim, Min-Sung [Sungkyunkwan University; Kim, Ji-Soo [Sungkyunkwan University; Kim, Chul-Hwan [Sungkyunkwan University

2017-06-29

Voltage regulation devices have been traditionally installed and utilized to support distribution voltages. Installations of distributed energy resources (DERs) in distribution systems are rapidly increasing, and many of these generation resources have variable and uncertain power output. These generators can significantly change the voltage profile for a feeder; therefore, in the distribution system planning stage of the optimal operation and dispatch of voltage regulation devices, possible high penetrations of DERs should be considered. In this paper, we model the IEEE 34-bus test feeder, including all essential equipment. An optimization method is adopted to determine the optimal siting and operation of the voltage regulation devices in the presence of distributed solar power generation. Finally, we verify the optimal configuration of the entire system through the optimization and simulation results.

An open-source, programmable pneumatic setup for operation and automated control of single- and multi-layer microfluidic devices

Directory of Open Access Journals (Sweden)

Kara Brower

2018-04-01

Full Text Available Microfluidic technologies have been used across diverse disciplines (e.g. high-throughput biological measurement, fluid physics, laboratory fluid manipulation but widespread adoption has been limited in part due to the lack of openly disseminated resources that enable non-specialist labs to make and operate their own devices. Here, we report the open-source build of a pneumatic setup capable of operating both single and multilayer (Quake-style microfluidic devices with programmable scripting automation. This setup can operate both simple and complex devices with 48 device valve control inputs and 18 sample inputs, with modular design for easy expansion, at a fraction of the cost of similar commercial solutions. We present a detailed step-by-step guide to building the pneumatic instrumentation, as well as instructions for custom device operation using our software, Geppetto, through an easy-to-use GUI for live on-chip valve actuation and a scripting system for experiment automation. We show robust valve actuation with near real-time software feedback and demonstrate use of the setup for high-throughput biochemical measurements on-chip. This open-source setup will enable specialists and novices alike to run microfluidic devices easily in their own laboratories. Keywords: Microfluidics, Pneumatics, Laboratory automation, Biochip, BioMEMs, Biohacking, Fluid handling, Micro total analysis systems (μTAS, Quake-style valves

Gain dynamics of quantum dot devices for dual-state operation

Energy Technology Data Exchange (ETDEWEB)

Kaptan, Y., E-mail: yuecel.kaptan@physik.tu-berlin.de; Herzog, B.; Kolarczik, M.; Owschimikow, N.; Woggon, U. [Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin (Germany); Schmeckebier, H.; Arsenijević, D.; Bimberg, D. [Institut für Festkörperphysik, Technische Universität Berlin, Berlin (Germany); Mikhelashvili, V.; Eisenstein, G. [Technion Institute of Technology, Faculty of Electrical Engineering, Haifa (Israel)

2014-06-30

Ground state gain dynamics of In(Ga)As-quantum dot excited state lasers are investigated via single-color ultrafast pump-probe spectroscopy below and above lasing threshold. Two-color pump-probe experiments are used to localize lasing and non-lasing quantum dots within the inhomogeneously broadened ground state. Single-color results yield similar gain recovery rates of the ground state for lasing and non-lasing quantum dots decreasing from 6 ps to 2 ps with increasing injection current. We find that ground state gain dynamics are influenced solely by the injection current and unaffected by laser operation of the excited state. This independence is promising for dual-state operation schemes in quantum dot based optoelectronic devices.

40 CFR 63.9525 - What are the installation, operation, and maintenance requirements for my weight measurement device?

Science.gov (United States)

2010-07-01

... measurement device? (a) If you use a solvent recovery system, you must install, operate, and maintain a weight... solvent mixer. If the weight measurement device cannot reproduce the value of the calibration weight..., and maintenance requirements for my weight measurement device? 63.9525 Section 63.9525 Protection of...

40 CFR 63.3967 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.3967 Section 63.3967... capture system and add-on control device operating limits during the performance test? During the... the operating limits required by § 63.3892 according to this section, unless you have received...

Challenges for single molecule electronic devices with nanographene and organic molecules. Do single molecules offer potential as elements of electronic devices in the next generation?

Science.gov (United States)

Enoki, Toshiaki; Kiguchi, Manabu

2018-03-01

Interest in utilizing organic molecules to fabricate electronic materials has existed ever since organic (molecular) semiconductors were first discovered in the 1950s. Since then, scientists have devoted serious effort to the creation of various molecule-based electronic systems, such as molecular metals and molecular superconductors. Single-molecule electronics and the associated basic science have emerged over the past two decades and provided hope for the development of highly integrated molecule-based electronic devices in the future (after the Si-based technology era has ended). Here, nanographenes (nano-sized graphene) with atomically precise structures are among the most promising molecules that can be utilized for electronic/spintronic devices. To manipulate single small molecules for an electronic device, a single molecular junction has been developed. It is a powerful tool that allows even small molecules to be utilized. External electric, magnetic, chemical, and mechanical perturbations can change the physical and chemical properties of molecules in a way that is different from bulk materials. Therefore, the various functionalities of molecules, along with changes induced by external perturbations, allows us to create electronic devices that we cannot create using current top-down Si-based technology. Future challenges that involve the incorporation of condensed matter physics, quantum chemistry calculations, organic synthetic chemistry, and electronic device engineering are expected to open a new era in single-molecule device electronic technology.

Spin transport in epitaxial graphene

Science.gov (United States)

Tbd, -

2014-03-01

Spintronics is a paradigm focusing on spin as the information vector in fast and ultra-low-power non volatile devices such as the new STT-MRAM. Beyond its widely distributed application in data storage it aims at providing more complex architectures and a powerful beyond CMOS solution for information processing. The recent discovery of graphene has opened novel exciting opportunities in terms of functionalities and performances for spintronics devices. We will present experimental results allowing us to assess the potential of graphene for spintronics. We will show that unprecedented highly efficient spin information transport can occur in epitaxial graphene leading to large spin signals and macroscopic spin diffusion lengths (~ 100 microns), a key enabler for the advent of envisioned beyond-CMOS spin-based logic architectures. We will also show that how the device behavior is well explained within the framework of the Valet-Fert drift-diffusion equations. Furthermore, we will show that a thin graphene passivation layer can prevent the oxidation of a ferromagnet, enabling its use in novel humide/ambient low-cost processes for spintronics devices, while keeping its highly surface sensitive spin current polarizer/analyzer behavior and adding new enhanced spin filtering property. These different experiments unveil promising uses of graphene for spintronics.

[Intelligent operating room suite : From passive medical devices to the self-thinking cognitive surgical assistant].

Science.gov (United States)

Kenngott, H G; Wagner, M; Preukschas, A A; Müller-Stich, B P

2016-12-01

Modern operating room (OR) suites are mostly digitally connected but until now the primary focus was on the presentation, transfer and distribution of images. Device information and processes within the operating theaters are barely considered. Cognitive assistance systems have triggered a fundamental rethinking in the automotive industry as well as in logistics. In principle, tasks in the OR, some of which are highly repetitive, also have great potential to be supported by automated cognitive assistance via a self-thinking system. This includes the coordination of the entire workflow in the perioperative process in both the operating theater and the whole hospital. With corresponding data from hospital information systems, medical devices and appropriate models of the surgical process, intelligent systems could optimize the workflow in the operating theater in the near future and support the surgeon. Preliminary results on the use of device information and automatically controlled OR suites are already available. Such systems include, for example the guidance of laparoscopic camera systems. Nevertheless, cognitive assistance systems that make use of knowledge about patients, processes and other pieces of information to improve surgical treatment are not yet available in the clinical routine but are urgently needed in order to automatically assist the surgeon in situation-related activities and thus substantially improve patient care.

40 CFR 63.9324 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... capture system and add-on control device operating limits during the performance test? 63.9324 Section 63... Requirements § 63.9324 How do I establish the emission capture system and add-on control device operating... the operating limits required by § 63.9302 according to this section, unless you have received...

Electron-Spin Filters Would Offer Spin Polarization Greater than 1

Science.gov (United States)

Ting, David Z.

2009-01-01

A proposal has been made to develop devices that would generate spin-polarized electron currents characterized by polarization ratios having magnitudes in excess of 1. Heretofore, such devices (denoted, variously, as spin injectors, spin polarizers, and spin filters) have typically offered polarization ratios having magnitudes in the approximate range of 0.01 to 0.1. The proposed devices could be useful as efficient sources of spin-polarized electron currents for research on spintronics and development of practical spintronic devices.

The design and implementation of device operation and management system based on LAMP

International Nuclear Information System (INIS)

Liu Shuzhen; Ma Lanxin; Qi Fazhi

2010-01-01

In order to manage devices with high efficiency and high quality and make it more standardized, more scientific and more modern, we use the platform of LAMP (Linux-Apache-Mysql-PHP) to develop a web-based equipment operation and management system. It uses the Browser/Server mode as the system mode and Mysql as the database to complete the function, such as query, modify, add, delete, batch import, batch export user information and device information, automatic alarm, user reviews and so on. (authors)

Possible fire hazard caused by mismatching electrical chargers with the incorrect device within the operating room.

LENUS (Irish Health Repository)

Hargrove, Martin

2012-02-03

It has come to our attention that numerous devices that need charging adaptors during cardiopulmonary bypass (CPB) have similar charging sockets but different voltage requirements. This has caused one of our devices in the operating theater to overheat and completely shut down when connected to an incorrect higher-voltage charger. The possibility of fire, device destruction, or patient harm in such circumstances is of serious concern.

A versatile nanotechnology to connect individual nano-objects for the fabrication of hybrid single-electron devices

International Nuclear Information System (INIS)

Bernand-Mantel, A; Bouzehouane, K; Seneor, P; Fusil, S; Deranlot, C; Petroff, F; Fert, A; Brenac, A; Notin, L; Morel, R

2010-01-01

We report on the high yield connection of single nano-objects as small as a few nanometres in diameter to separately elaborated metallic electrodes, using a 'table-top' nanotechnology. Single-electron transport measurements validate that transport occurs through a single nano-object. The vertical geometry of the device natively allows an independent choice of materials for each electrode and the nano-object. In addition ferromagnetic materials can be used without encountering oxidation problems. The possibility of elaborating such hybrid nanodevices opens new routes for the democratization of spintronic studies in low dimensions.

[Discussion on Quality Evaluation Method of Medical Device During Life-Cycle in Operation Based on the Analytic Hierarchy Process].

Science.gov (United States)

Zheng, Caixian; Zheng, Kun; Shen, Yunming; Wu, Yunyun

2016-01-01

The content related to the quality during life-cycle in operation of medical device includes daily use, repair volume, preventive maintenance, quality control and adverse event monitoring. In view of this, the article aims at discussion on the quality evaluation method of medical devices during their life cycle in operation based on the Analytic Hierarchy Process (AHP). The presented method is proved to be effective by evaluating patient monitors as example. The method presented in can promote and guide the device quality control work, and it can provide valuable inputs to decisions about purchase of new device.

Silicon spintronics: Progress and challenges

Energy Technology Data Exchange (ETDEWEB)

Sverdlov, Viktor; Selberherr, Siegfried, E-mail: Selberherr@TUWien.ac.at

2015-07-14

Electron spin attracts much attention as an alternative to the electron charge degree of freedom for low-power reprogrammable logic and non-volatile memory applications. Silicon appears to be the perfect material for spin-driven applications. Recent progress and challenges regarding spin-based devices are reviewed. An order of magnitude enhancement of the electron spin lifetime in silicon thin films by shear strain is predicted and its impact on spin transport in SpinFETs is discussed. A relatively weak coupling between spin and effective electric field in silicon allows magnetoresistance modulation at room temperature, however, for long channel lengths. Due to tunneling magnetoresistance and spin transfer torque effects, a much stronger coupling between the spin (magnetization) orientation and charge current is achieved in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS compatible and possesses all properties needed for future universal memory. Designs of spin-based non-volatile MRAM cells are presented. By means of micromagnetic simulations it is demonstrated that a substantial reduction of the switching time can be achieved. Finally, it is shown that any two arbitrary memory cells from an MRAM array can be used to perform a logic operation. Thus, an intrinsic non-volatile logic-in-memory architecture can be realized.

Silicon spintronics: Progress and challenges

International Nuclear Information System (INIS)

Sverdlov, Viktor; Selberherr, Siegfried

2015-01-01

Electron spin attracts much attention as an alternative to the electron charge degree of freedom for low-power reprogrammable logic and non-volatile memory applications. Silicon appears to be the perfect material for spin-driven applications. Recent progress and challenges regarding spin-based devices are reviewed. An order of magnitude enhancement of the electron spin lifetime in silicon thin films by shear strain is predicted and its impact on spin transport in SpinFETs is discussed. A relatively weak coupling between spin and effective electric field in silicon allows magnetoresistance modulation at room temperature, however, for long channel lengths. Due to tunneling magnetoresistance and spin transfer torque effects, a much stronger coupling between the spin (magnetization) orientation and charge current is achieved in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS compatible and possesses all properties needed for future universal memory. Designs of spin-based non-volatile MRAM cells are presented. By means of micromagnetic simulations it is demonstrated that a substantial reduction of the switching time can be achieved. Finally, it is shown that any two arbitrary memory cells from an MRAM array can be used to perform a logic operation. Thus, an intrinsic non-volatile logic-in-memory architecture can be realized

Powering autonomous sensors with miniaturized piezoelectric based energy harvesting devices operating at very low frequency

Science.gov (United States)

Ferin, G.; Bantignies, C.; Le Khanh, H.; Flesch, E.; Nguyen-Dinh, A.

2015-12-01

Harvesting energy from ambient mechanical vibrations is a smart and efficient way to power autonomous sensors and support innovative developments in IoT (Internet of Things), WSN (Wireless Sensor Network) and even implantable medical devices. Beyond the environmental operating conditions, efficiency of such devices is mainly related to energy source properties like the amplitude of vibrations and its spectral contain and some of these applications exhibit a quite low frequency spectrum where harvesting surrounding mechanical energy make sense, typically 5-50Hz for implantable medical devices or 50Hz-150Hz for industrial machines. Harvesting such low frequency vibrations is a challenge since it leads to adapt the resonator geometries to the targeted frequency or to use out-off band indirect harvesting strategies. In this paper we present a piezoelectric based vibrational energy harvesting device (PEH) which could be integrated into a biocompatible package to power implantable sensor or therapeutic medical devices. The presented architecture is a serial bimorph laminated with ultra-thinned (ranging from 15μm to 100μm) outer PZT “skins” that could operate at a “very low frequency”, below 25Hz typically. The core process flow is disclosed and performances highlighted with regards to other low frequency demonstrations.

Powering autonomous sensors with miniaturized piezoelectric based energy harvesting devices operating at very low frequency

International Nuclear Information System (INIS)

Ferin, G; Bantignies, C; Khanh, H Le; Flesch, E; Nguyen-Dinh, A

2015-01-01

Harvesting energy from ambient mechanical vibrations is a smart and efficient way to power autonomous sensors and support innovative developments in IoT (Internet of Things), WSN (Wireless Sensor Network) and even implantable medical devices. Beyond the environmental operating conditions, efficiency of such devices is mainly related to energy source properties like the amplitude of vibrations and its spectral contain and some of these applications exhibit a quite low frequency spectrum where harvesting surrounding mechanical energy make sense, typically 5-50Hz for implantable medical devices or 50Hz-150Hz for industrial machines. Harvesting such low frequency vibrations is a challenge since it leads to adapt the resonator geometries to the targeted frequency or to use out-off band indirect harvesting strategies. In this paper we present a piezoelectric based vibrational energy harvesting device (PEH) which could be integrated into a biocompatible package to power implantable sensor or therapeutic medical devices. The presented architecture is a serial bimorph laminated with ultra-thinned (ranging from 15μm to 100μm) outer PZT “skins” that could operate at a “very low frequency”, below 25Hz typically. The core process flow is disclosed and performances highlighted with regards to other low frequency demonstrations. (paper)

Magnetoresistance Effect in NiFe/BP/NiFe Vertical Spin Valve Devices

Directory of Open Access Journals (Sweden)

Leilei Xu

2017-01-01

Full Text Available Two-dimensional (2D layered materials such as graphene and transition metal dichalcogenides are emerging candidates for spintronic applications. Here, we report magnetoresistance (MR properties of a black phosphorus (BP spin valve devices consisting of thin BP flakes contacted by NiFe ferromagnetic (FM electrodes. The spin valve effect has been observed from room temperature to 4 K, with MR magnitudes of 0.57% at 4 K and 0.23% at 300 K. In addition, the spin valve resistance is found to decrease monotonically as temperature is decreased, indicating that the BP thin film works as a conductive interlayer between the NiFe electrodes.

Temperature dependence of magnetically dead layers in ferromagnetic thin-films

Directory of Open Access Journals (Sweden)

M. Tokaç

2017-11-01

Full Text Available Polarized neutron reflectometry has been used to study interface magnetism and magnetic dead layers in model amorphous CoFeB:Ta alloy thin-film multilayers with Curie temperatures tuned to be below room-temperature. This allows temperature dependent variations in the effective magnetic thickness of the film to be determined at temperatures that are a significant fraction of the Curie temperature, which cannot be achieved in the material systems used for spintronic devices. In addition to variation in the effective magnetic thickness due to compositional grading at the interface with the tantalum capping layer, the key finding is that at the interface between ferromagnetic film and GaAs(001 substrate local interfacial alloying creates an additional magnetic dead-layer. The thickness of this magnetic dead-layer is temperature dependent, which may have significant implications for elevated-temperature operation of hybrid ferromagnetic metal-semiconductor spintronic devices.

40 CFR Table 1 to Subpart Ssss of... - Operating Limits if Using Add-on Control Devices and Capture System

Science.gov (United States)

2010-07-01

... Using Add-on Control Devices and Capture System If you are required to comply with operating limits by... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits if Using Add-on Control Devices and Capture System 1 Table 1 to Subpart SSSS of Part 63 Protection of Environment...

40 CFR Table 1 to Subpart Jjjj of... - Operating Limits if Using Add-On Control Devices and Capture System

Science.gov (United States)

2010-07-01

... Limits if Using Add-On Control Devices and Capture System If you are required to comply with operating... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits if Using Add-On Control Devices and Capture System 1 Table 1 to Subpart JJJJ of Part 63 Protection of Environment...

40 CFR Table 2 to Subpart Oooo of... - Operating Limits if Using Add-On Control Devices and Capture System

Science.gov (United States)

2010-07-01

... OOOO of Part 63—Operating Limits if Using Add-On Control Devices and Capture System If you are required... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits if Using Add-On Control Devices and Capture System 2 Table 2 to Subpart OOOO of Part 63 Protection of Environment...

X-ray analysis of spintronic semiconductor and half metal thin film systems; Roentgenstrukturuntersuchungen an spintronischen Halbleiter- und Halbmetall-Duennschichtsystemen

Energy Technology Data Exchange (ETDEWEB)

Stahl, Andreas

2010-07-01

In this work the structural properties of spintronic semiconductor and halfmetalic thin-film systems were investigated. The layer thicknesses and interface roughnesses of the multi-layer systems were estimated by X-ray reflectivity measurements. The fits were performed using the software Fewlay which uses the Parratt formalism to calculate the reflectivities. The relaxation of the films was analyzed by reciprocal space mapping on preferably highly indexed Bragg reflexes. (orig.)

Preliminary audiologic and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device: A systematic review.

Science.gov (United States)

Bezdjian, Aren; Bruijnzeel, Hanneke; Daniel, Sam J; Grolman, Wilko; Thomeer, Hans G X M

2017-10-01

To delineate the auditory functional improvement and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device. Eligible articles presenting patients implanted with the Sophono™ were identified through a comprehensive search of PubMed and Embase electronic databases. All relevant articles were reviewed to justify inclusion independently by 2 authors. Studies that successfully passed critical appraisal for directness of evidence and risk of bias were included. From a total of 125 articles, 8 studies encompassing 86 patients using 99 implants were selected. Most patients (79.1%) were children. Ear atresia (67.5%) was the most frequently reported indication for Sophono™ implantation. Overall pure tone average auditory improvement was 31.10 (±8.29) decibel. During a mean follow-up time of 12.48 months, 25 patients (29%) presented with post-operative complications from which 3 were deemed as serious implant-related adverse events (3.5%). The Sophono™ transcutaneous bone conduction device shows promising functional improvement, no intra-operative complications and minor post-operative skin related complications. If suitable, the device could be a proposed solution for the rehabilitation of hearing in children meeting eligibility criteria. A wearing schedule must be implemented in order to reduce magnet-related skin complications. Copyright © 2017 Elsevier B.V. All rights reserved.

Energy performance of a micro-cogeneration device during transient and steady-state operation: Experiments and simulations

International Nuclear Information System (INIS)

Rosato, Antonio; Sibilio, Sergio

2013-01-01

Micro-cogeneration is a well-established technology and its deployment has been considered by the European Community as one of the most effective measure to save primary energy and to reduce greenhouse gas emissions. As a consequence, the estimation of the potential impact of micro-cogeneration devices is necessary to design policy and to energetically, ecologically and economically rank these systems among other potential energy saving and CO 2 -reducing measures. Even if transient behaviour can be very important when the engine is frequently started and stopped and allowed to cool-down in between, for the sake of simplicity mainly static and simplified methods are used for assessing the performance of cogeneration devices, completely neglecting the dynamic response of the units themselves. In the first part of this paper a series of experiments is illustrated and discussed in detail in order to highlight and compare the transient and stationary operation of a natural gas fuelled reciprocating internal combustion engine based cogeneration unit with 6.0 kW as nominal electric output and 11.7 kW as nominal thermal output. The measured performance of the cogeneration device is also compared with the performance of the system calculated on the basis of the efficiency values suggested by the manufacturer in order to highlight and quantify the discrepancy between the two approaches in evaluating the unit operation. Finally the experimental data are also compared with those predicted by a simulation model developed within IEA/ECBCS Annex 42 and experimentally calibrated by the authors in order to assess the model reliability for studying and predicting the performance of the system under different operating scenarios. -- Highlights: ► Transient operation of a cogeneration system has been experimentally investigated. ► Steady-state operation of a cogeneration device has been experimentally evaluated. ► Measured data have been compared with those predicted by a

High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

International Nuclear Information System (INIS)

Galanakis, I.

2015-01-01

Half-metallic Co 2 MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co 2 MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co 2 MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co 2 MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices

Process control device

International Nuclear Information System (INIS)

Hayashi, Toshifumi; Kobayashi, Hiroshi.

1994-01-01

A process control device comprises a memory device for memorizing a plant operation target, a plant state or a state of equipments related with each other as control data, a read-only memory device for storing programs, a plant instrumentation control device or other process control devices, an input/output device for performing input/output with an operator, and a processing device which conducts processing in accordance with the program and sends a control demand or a display demand to the input/output device. The program reads out control data relative to a predetermined operation target, compares and verify them with actual values to read out control data to be a practice premise condition which is further to be a practice premise condition if necessary, thereby automatically controlling the plant or requiring or displaying input. Practice presuming conditions for the operation target can be examined succesively in accordance with the program without constituting complicated logical figures and AND/OR graphs. (N.H.)

Operating room fire prevention: creating an electrosurgical unit fire safety device.

Science.gov (United States)

Culp, William C; Kimbrough, Bradly A; Luna, Sarah; Maguddayao, Aris J

2014-08-01

To reduce the incidence of surgical fires. Operating room fires represent a potentially life-threatening hazard and are triggered by the electrosurgical unit (ESU) pencil. Carbon dioxide is a fire suppressant and is a routinely used medical gas. We hypothesize that a shroud of protective carbon dioxide covering the tip of the ESU pencil displaces oxygen, thereby preventing fire ignition. Using 3-dimensional modeling techniques, a polymer sleeve was created and attached to an ESU pencil. This sleeve was connected to a carbon dioxide source and directed the gas through multiple precisely angled ports, generating a cone of fire-suppressive carbon dioxide surrounding the active pencil tip. This device was evaluated in a flammability test chamber containing 21%, 50%, and 100% oxygen with sustained ESU activation. The sleeve was tested with and without carbon dioxide (control) until a fuel was ignited or 30 seconds elapsed. Time to ignition was measured by high-speed videography. Fires were ignited with each control trial (15/15 trials). The control group median ± SD ignition time in 21% oxygen was 3.0 ± 2.4 seconds, in 50% oxygen was 0.1 ± 1.8 seconds, and in 100% oxygen was 0.03 ± 0.1 seconds. No fire was observed when the fire safety device was used in all concentrations of oxygen (0/15 trials; P fire ignition was 76% to 100%. A sleeve creating a cone of protective carbon dioxide gas enshrouding the sparks from an ESU pencil effectively prevents fire in a high-flammability model. Clinical application of this device may reduce the incidence of operating room fires.

Electric-Field-Driven Dual Vacancies Evolution in Ultrathin Nanosheets Realizing Reversible Semiconductor to Half-Metal Transition.

Science.gov (United States)

Lyu, Mengjie; Liu, Youwen; Zhi, Yuduo; Xiao, Chong; Gu, Bingchuan; Hua, Xuemin; Fan, Shaojuan; Lin, Yue; Bai, Wei; Tong, Wei; Zou, Youming; Pan, Bicai; Ye, Bangjiao; Xie, Yi

2015-12-02

Fabricating a flexible room-temperature ferromagnetic resistive-switching random access memory (RRAM) device is of fundamental importance to integrate nonvolatile memory and spintronics both in theory and practice for modern information technology and has the potential to bring about revolutionary new foldable information-storage devices. Here, we show that a relatively low operating voltage (+1.4 V/-1.5 V, the corresponding electric field is around 20,000 V/cm) drives the dual vacancies evolution in ultrathin SnO2 nanosheets at room temperature, which causes the reversible transition between semiconductor and half-metal, accompanyied by an abrupt conductivity change up to 10(3) times, exhibiting room-temperature ferromagnetism in two resistance states. Positron annihilation spectroscopy and electron spin resonance results show that the Sn/O dual vacancies in the ultrathin SnO2 nanosheets evolve to isolated Sn vacancy under electric field, accounting for the switching behavior of SnO2 ultrathin nanosheets; on the other hand, the different defect types correspond to different conduction natures, realizing the transition between semiconductor and half-metal. Our result represents a crucial step to create new a information-storage device realizing the reversible transition between semiconductor and half-metal with flexibility and room-temperature ferromagnetism at low energy consumption. The as-obtained half-metal in the low-resistance state broadens the application of the device in spintronics and the semiconductor to half-metal transition on the basis of defects evolution and also opens up a new avenue for exploring random access memory mechanisms and finding new half-metals for spintronics.

Inter operability of smart field devices on an open field-bus: from laboratory tests to on-site applications

International Nuclear Information System (INIS)

Piguet, M.; Favennec, J.M.

1997-01-01

The paper presents a field trial held in EDF's R and D laboratories concerning smart field instruments (sensors, I/O modules, transmitters) operating on the WorldFIP field-bus. The trial put into operation a supervisory control and data acquisition (SCADA) system on the field-bus with available industrial field devices and software tools. The field trial enables EDF's teams to address the inter-operability issue regarding smart field devices and to prepare the forthcoming step from analog to fully digital measurement technology by evaluating new services and higher performances provided. Possible architectures for process control and on-site testing purposes have been identified. A first application for a flow-measuring rig is under way. It implements a WorldFIP field-bus based DCS with FIP/HART multiplexers, FIP and HART smart devices (sensors and actuators) and a field management system. (authors)

40 CFR 63.4567 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.4567 Section 63.4567... Emission Rate with Add-on Controls Option § 63.4567 How do I establish the emission capture system and add-on control device operating limits during the performance test? During the performance test required...

Magnetic Transport in Spin Antiferromagnets for Spintronics Applications

Directory of Open Access Journals (Sweden)

Mohamed Azzouz

2017-10-01

Full Text Available Had magnetic monopoles been ubiquitous as electrons are, we would probably have had a different form of matter, and power plants based on currents of these magnetic charges would have been a familiar scene of modern technology. Magnetic dipoles do exist, however, and in principle one could wonder if we can use them to generate magnetic currents. In the present work, we address the issue of generating magnetic currents and magnetic thermal currents in electrically-insulating low-dimensional Heisenberg antiferromagnets by invoking the (broken electricity-magnetism duality symmetry. The ground state of these materials is a spin-liquid state that can be described well via the Jordan–Wigner fermions, which permit an easy definition of the magnetic particle and thermal currents. The magnetic and magnetic thermal conductivities are calculated in the present work using the bond–mean field theory. The spin-liquid states in these antiferromagnets are either gapless or gapped liquids of spinless fermions whose flow defines a current just as the one defined for electrons in a Fermi liquid. The driving force for the magnetic current is a magnetic field with a gradient along the magnetic conductor. We predict the generation of a magneto-motive force and realization of magnetic circuits using low-dimensional Heisenberg antiferromagnets. The present work is also about claiming that what the experiments in spintronics attempt to do is trying to treat the magnetic degrees of freedoms on the same footing as the electronic ones.

40 CFR 63.4767 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.4767 Section 63.4767... Rate with Add-on Controls Option § 63.4767 How do I establish the emission capture system and add-on control device operating limits during the performance test? During the performance test required by § 63...

40 CFR 63.4167 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.4167 Section 63.4167... with Add-on Controls Option § 63.4167 How do I establish the emission capture system and add-on control device operating limits during the performance test? During the performance test required by § 63.4160...

PARAMETER DETERMINATION FOR ADDITIONAL OPERATING FORCE MECHANISM IN DEVICE FOR PNEUMO-CENTRIFUGAL MACHINING OF BALL-SHAPED WORKPIECES

Directory of Open Access Journals (Sweden)

A. A. Sukhotsky

2014-01-01

Full Text Available The paper describes development of the methodology for optimization of parameters for an additional operating force mechanism in a device for pneumo-centrifugal machining of glass balls. Specific feature in manufacturing glass balls for micro-optics in accordance with technological process for obtaining ball-shaped workpieces is grinding and polishing of spherical surface in a free state. In this case component billets of future balls are made in the form of cubes and the billets are given preliminary a form of ball with the help of rough grinding. An advanced method for obtaining ball-shaped work-pieces from brittle materials is a pneumocentrifugal machining. This method presupposes an application of two conic rings with abrasive working surfaces which are set coaxially with large diameters to each other and the billets are rolled along these rings. Rotation of the billets is conveyed by means of pressure medium.The present devices for pneumo-centrifugal machining are suitable for obtaining balls up to 6 mm. Machining of the work-pieces with full spherical surfaces and large diameter is non-productive due to impossibility to ensure a sufficient force on the billet in the working zone. For this reason the paper proposes a modified device where an additional force on the machined billet is created by upper working disc that is making a reciprocating motion along an axis of abrasive conic rings. The motion is realized with the help of a cylindrical camshaft mechanism in the form of a ring with a profile working end face and the purpose of present paper is to optimize parameters of the proposed device.The paper presents expressions for calculation of constitutive parameters of the additional operating force mechanism including parameters of loading element motion, main dimensions of the additional operating force mechanism and parameters of a profile element in the additional operating force mechanism.Investigation method is a mathematical

Defective aluminium nitride nanotubes: a new way for spintronics? A density functional study

International Nuclear Information System (INIS)

Simeoni, M; Santucci, S; Picozzi, S; Delley, B

2006-01-01

The structural and electronic properties (in terms of Mulliken charges, density of states and band structures) of pristine and defective (10,0) AlN nanotubes have been calculated within density functional theory. The results show that, in several defective tubes, a spontaneous spin-polarization arises, due to the presence of spin-split flat bands close to the Fermi level, with a strong localization of the corresponding electronic states and of the magnetic moments. The highest positive spin-magnetization (3 μ B per cell) is found for the vacancy in the Al site, while the other magnetic tubes (the vacancy in N, C and O substitutional for N and Al, respectively) show a magnetization of only 1 μ B per cell. The spontaneous magnetization of some defective tubes might open the way to their use for spintronic applications

High spin-polarization in ultrathin Co{sub 2}MnSi/CoPd multilayers

Energy Technology Data Exchange (ETDEWEB)

Galanakis, I., E-mail: galanakis@upatras.gr

2015-03-01

Half-metallic Co{sub 2}MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co{sub 2}MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co{sub 2}MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co{sub 2}MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices.

Rashba and Dresselhaus Couplings in Halide Perovskites: Accomplishments and Opportunities for Spintronics and Spin-Orbitronics.

Science.gov (United States)

Kepenekian, Mikaël; Even, Jacky

2017-07-20

In halide hybrid organic-inorganic perovskites (HOPs), spin-orbit coupling (SOC) presents a well-documented large influence on band structure. However, SOC may also present more exotic effects, such as Rashba and Dresselhaus couplings. In this Perspective, we start by recalling the main features of this effect and what makes HOP materials ideal candidates for the generation and tuning of spin-states. Then, we detail the main spectroscopy techniques able to characterize these effects and their application to HOPs. Finally, we discuss potential applications in spintronics and in spin-orbitronics in those nonmagnetic systems, which would complete the skill set of HOPs and perpetuate their ride on the crest of the wave of popularity started with optoelectronics and photovoltaics.

40 CFR Table 1 to Subpart IIIi of... - Operating Limits for Capture Systems and Add-On Control Devices

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits for Capture Systems... 63—Operating Limits for Capture Systems and Add-On Control Devices If you are required to comply with operating limits by § 63.3093, you must comply with the applicable operating limits in the following table...

Ferromagnets as pure spin current generators and detectors

Science.gov (United States)

Qu, Danru; Miao, Bingfeng; Chien, Chia -Ling; Huang, Ssu -Yen

2015-09-08

Provided is a spintronics device. The spintronics can include a ferromagnetic metal layer, a positive electrode disposed on a first surface portion of the ferromagnetic metal layer, and a negative electrode disposed on a second surface portion of the ferromagnetic metal.

40 CFR Table 4 to Subpart Xxxx of... - Operating Limits for Puncture Sealant Application Control Devices

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Operating Limits for Puncture Sealant Application Control Devices 4 Table 4 to Subpart XXXX of Part 63 Protection of Environment ENVIRONMENTAL... Manufacturing Pt. 63, Subpt. XXXX, Table 4 Table 4 to Subpart XXXX of Part 63—Operating Limits for Puncture...

Power source device for thermonuclear device

International Nuclear Information System (INIS)

Ozaki, Akira.

1992-01-01

The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)

Scanning-SQUID investigation of spin-orbit torque acting on yttrium iron garnet devices

Science.gov (United States)

Rosenberg, Aaron J.; Jermain, Colin L.; Aradhya, Sriharsha V.; Brangham, Jack T.; Nowack, Katja C.; Kirtley, John R.; Yang, Fengyuan; Ralph, Daniel C.; Moler, Kathryn A.

Successful manipulation of electrically insulating magnets, such as yttrium iron garnet, by by current-driven spin-orbit torques could provide a highly efficient platform for spintronic memory. Compared to devices fabricated using magnetic metals, magnetic insulators have the advantage of the ultra-low magnetic damping and the elimination of shunting currents in the magnet that reduce the torque efficiency. Here, we apply current in the spin Hall metal β-Ta to manipulate the magnetic orientation of micron-sized, electrically-insulating yttrium iron garnet devices. We do not observe spin-torque switching even for applied currents well above the critical current expected in a macrospin switching model. This suggests either inefficient transfer of spin torque at our Ta/YIG interface or a breakdown of the macrospin approximation. This work is supported by FAME, one of six centers of STARnet sponsored by MARCO and DARPA. The SQUID microscope and sensors were developed with support from the NSF-sponsored Center NSF-NSEC 0830228, and from NSF IMR-MIP 0957616.

Plant monitoring device

International Nuclear Information System (INIS)

Moriyama, Kunio.

1991-01-01

The monitoring device of the present invention is most suitable to early detection for equipment abnormality, or monitoring of state upon transient conditions such as startup and shutdown of an electric power plant, a large-scaled thermonuclear device and an accelerator plant. That is, in existent moitoring devices, acquired data are stored and the present operation states are monitored in comparison. A plant operation aquisition data reproduction section is disposed to the device. From the past operation conditions stored in the plant operation data aquisition reproducing section, the number of operation cycles that agrees with the present plant operation conditions is sought, to determine the agreed aquired data. Since these aquired data are time sequential data measured based on the standard time determined by the operation sequence, aquired data can be reproduced successively on every sample pitches. With such a constitution, aquired data under the same operation conditions as the present conditions are displayed together with the measured data. Accordingly, accurate monitoring can be conducted from the start-up to the shutdown of the plant. (I.S.)

Spin-current diode with a ferromagnetic semiconductor

International Nuclear Information System (INIS)

Sun, Qing-Feng; Xie, X. C.

2015-01-01

Diode is a key device in electronics: the charge current can flow through the device under a forward bias, while almost no current flows under a reverse bias. Here, we propose a corresponding device in spintronics: the spin-current diode, in which the forward spin current is large but the reversed one is negligible. We show that the lead/ferromagnetic quantum dot/lead system and the lead/ferromagnetic semiconductor/lead junction can work as spin-current diodes. The spin-current diode, a low dissipation device, may have important applications in spintronics, as the conventional charge-current diode does in electronics

Automatic limit switch system for scintillation device and method of operation

International Nuclear Information System (INIS)

Brunnett, C.J.; Ioannou, B.N.

1976-01-01

A scintillation scanner is described having an automatic limit switch system for setting the limits of travel of the radiation detection device which is carried by a scanning boom. The automatic limit switch system incorporates position responsive circuitry for developing a signal representative of the position of the boom, reference signal circuitry for developing a signal representative of a selected limit of travel of the boom, and comparator circuitry for comparng these signals in order to control the operation of a boom drive and indexing mechanism. (author)

Fuel pattern recognition device

International Nuclear Information System (INIS)

Sato, Tomomi.

1995-01-01

The device of the present invention monitors normal fuel exchange upon fuel exchanging operation carried out in a reactor of a nuclear power plant. Namely, a fuel exchanger is movably disposed to the upper portion of the reactor and exchanges fuels. An exclusive computer receives operation signals of the fuel exchanger during operation as inputs, and outputs reactor core fuel pattern information signals to a fuel arrangement diagnosis device. An underwater television camera outputs image signals of a fuel pattern in the reactor core to an image processing device. If there is any change in the image signals for the fuel pattern as a result of the fuel exchange operation of the fuel exchanger, the image processing device outputs the change as image signals to the fuel pattern diagnosis device. The fuel pattern diagnosis device compares the pattern information signals from the exclusive computer with the image signals from the image processing device, to diagnose the result of the fuel exchange operation performed by the fuel exchanger and inform the diagnosis by means of an image display. (I.S.)

Cryogenic operation strategy for the SST-1 device

International Nuclear Information System (INIS)

Tanna, V.L.; Pradhan, S.

2013-01-01

The SST-1 has been operated since 2012 as part of its engineering commissioning and almost 5 experimental campaigns have been successfully completed. Before final assembling, cool-down and current excitation tests for the Toroidal field coils and PF 3 (Upper) coil were demonstrated successfully as part of validation under coils test program. These superconducting coils consist of a cable-in-conduit conductor, (CICC) is cooled by the forced-flow Two-phase flow as well as supercritical helium conditions. During the recent campaigns, hydraulic characteristics of whole superconducting magnets along with the TF case cooling were studied as an integral system. Based on the experimental observations, efforts have been made to cryo stable conditions of the SST-1 superconducting magnets system in order to produce steady state TF magnetic field of 1.5 T at the plasma center. Optimization of Helium plant related processes have been worked out and implemented to realize the successful SST-1 device operation over a week. In order to have long experimental campaign, an intermediate temperature cooling down philosophy has been adopted. The complete superconducting coils flow distribution among their cooling channels and pressure head requirements were studied from the measurements. In this paper, we will highlight the recent cool-down results, flow distribution and temperature uniformity aspects while cooling down the SST-1 magnets system. (author)

Half metallic ferromagnet Pr_0_._9_5Mn_0_._9_3_9O_3 for spin based devices

International Nuclear Information System (INIS)

Santhosh Kumar, B.; Praveen Shankar, N.; Venkateswaran, C.; Manimuthu, P.

2016-01-01

Half Metallic Ferromagnets (HMF) are excellent candidates for spintronics devices due to their unusual 3d and 4s bands. Band theory and first principles calculations strongly predict that Pr based compounds are promising HMF candidates due to their spin hybridisation. Among all Pr based HMF, Pr_0_._9_5Mn_0_._9_3_9O_3 is special because of its pervoskite structure. The different oxidation states of Mn and Pr will enhance the hybridisation of 3d and 4f bands. The present study is experimental effort on the preparation of Pr based compounds

Gender differences in use of hearing protection devices among farm operators

Directory of Open Access Journals (Sweden)

Marjorie C McCullagh

2016-01-01

Full Text Available Purpose: Although farm operators have frequent exposure to hazardous noise and high rates of noise-induced hearing loss, they have low use of hearing protection devices (HPDs. Women represent about one-third of farm operators, and their numbers are climbing. However, among published studies examining use of HPDs in this worker group, none have examined gender-related differences. The purpose of this study was to examine gender-related differences in use of hearing protection and related predictors among farm operators. Materials and Methods: Data previously collected at farm shows and by telephone were analyzed using t-tests and generalized linear model with zero inflated negative binomial (ZINB distribution. Findings: The difference in rate of hearing protector use between men and women farm operators was not significant. There was no difference between men and women in most hearing protector-related attitudes and beliefs. Conclusion: Although men and women farm operators had similar rates of use of hearing protectors when working in high-noise environments, attitudes about HPD use differed. Specifically, interpersonal role modeling was a predictor of HPD use among women, but not for men. This difference suggests that while farm operators of both genders may benefit from interventions designed to reduce barriers to HPD use (e.g., difficulty communicating with co-workers and hearing warning sounds, farm women have unique needs in relation to cognitive-perceptual factors that predict HPD use. Women farm operators may lack role models for use of HPDs (e.g., in peers and advertising, contributing to their less frequent use of protection.

Device-Centric Monitoring for Mobile Device Management

OpenAIRE

Chircop, Luke; Colombo, Christian; Pace, Gordon J.

2016-01-01

The ubiquity of computing devices has led to an increased need to ensure not only that the applications deployed on them are correct with respect to their specifications, but also that the devices are used in an appropriate manner, especially in situations where the device is provided by a party other than the actual user. Much work which has been done on runtime verification for mobile devices and operating systems is mostly application-centric, resulting in global, device-centri...

New tools for C.A.D. of input devices for tele-operation with force feedback

International Nuclear Information System (INIS)

Gosselin, F.

2000-01-01

The performances of a tele-operation system are related to the master arm's ability to emulate the behavior of the remote environment. Ideally, it allows the operator to control the slave arm in a natural way as if that were an extension of its own body. The criteria to be checked for that are known but contradictory. It is thus necessary to make trade-offs on which there is not consensus. Existing input devices are therefore very varied thus more or less adapted to the tasks considered, which is in general checked a posteriori. In this document, we propose an original approach allowing to dimension the master arm a priori according to the use which one wishes to make. For that, we developed two tools: - the first one makes it possible to establish his specifications by taking account of the transmission of information between the operator and the slave arm. By exploiting their respective limitations, one is assured that the master arm will not limit the performances of the system, - the second one allows to design it (kinematics, size, motorization... ) according to the preceding specifications. For that, we use well-known theoretical tools which however are approached here as design tools. This leads to the definition of new concepts which do not appear in the literature. This approach is used to establish the specifications of a master arm for nuclear and offshore tele-operation then to design two input devices answering these specifications. The first has 3 degrees of freedom with force feedback. Its performances are higher than those of the best existing input devices. The second is a mock-up of a 6 degrees of freedom master arm. It uses a new parallel structure that is redundant in actuation and whose performances are remarkable. (author) [fr

k-Space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

OpenAIRE

Lev, L. L.; Maiboroda, I. O.; Husanu, M. -A.; Grichuk, E. S.; Chumakov, N. K.; Ezubchenko, I. S.; Chernykh, I. A.; Wang, X.; Tobler, B.; Schmitt, T.; Zanaveskin, M. L.; Valeyev, V. G.; Strocov, V. N.

2018-01-01

Nanostructures based on buried interfaces and heterostructures are at the heart of modern semiconductor electronics as well as future devices utilizing spintronics, multiferroics, topological effects and other novel operational principles. Knowledge of electronic structure of these systems resolved in electron momentum k delivers unprecedented insights into their physics. Here, we explore 2D electron gas formed in GaN/AlGaN high-electron-mobility transistor (HEMT) heterostructures with an ult...

Equipment abnormality monitoring device

International Nuclear Information System (INIS)

Ando, Yasumasa

1991-01-01

When an operator hears sounds in a plantsite, the operator compares normal sounds of equipment which he previously heard and remembered with sounds he actually hears, to judge if they are normal or abnormal. According to the method, there is a worry that abnormal conditions can not be appropriately judged in a case where the number of objective equipments is increased and in a case that the sounds are changed gradually slightly. Then, the device of the present invention comprises a plurality of monitors for monitoring the operation sound of equipments, a recording/reproducing device for recording and reproducing the signals, a selection device for selecting the reproducing signals among the recorded signals, an acoustic device for converting the signals to sounds, a switching device for switching the signals to be transmitted to the acoustic device between to signals of the monitor and the recording/reproducing signals. The abnormality of the equipments can be determined easily by comparing the sounds representing the operation conditions of equipments for controlling the plant operation and the sounds recorded in their normal conditions. (N.H.)

A controllable spin prism

International Nuclear Information System (INIS)

Hakioglu, T

2009-01-01

Based on Khodas et al (2004 Phys. Rev. Lett. 92 086602), we propose a device acting like a controllable prism for an incident spin. The device is a large quantum well where Rashba and Dresselhaus spin-orbit interactions are present and controlled by the plunger gate potential, the electric field and the barrier height. A totally destructive interference can be manipulated externally between the Rashba and Dresselhaus couplings. The spin-dependent transmission/reflection amplitudes are calculated as the control parameters are changed. The device operates as a spin prism/converter/filter in different regimes and may stimulate research in promising directions in spintronics in analogy with linear optics.

Tuning spin-polarized transport in organic semiconductors

Science.gov (United States)

Mattana, Richard; Galbiati, Marta; Delprat, Sophie; Tatay, Sergio; Deranlot, Cyrile; Seneor, Pierre; Petroff, Frederic

Molecular spintronics is an emerging research field at the frontier between organic chemistry and the spintronics. Compared to traditional inorganic materials molecules are flexible and can be easily tailored by chemical synthesis. Due to their theoretically expected very long spin lifetime, they were first only seen as the ultimate media for spintronics devices. It was recently that new spintronics tailoring could arise from the chemical versatility brought by molecules. The hybridization between a ferromagnet and molecules induces a spin dependent broadening and energy shifting of the molecular orbitals leading to an induced spin polarization on the first molecular layer. This spin dependent hybridization can be used to tailor the spin dependent transport in organic spintronics devices. We have studied vertical Co/Alq3/Co organic spin valves. The negative magnetoresistance observed is the signature of different coupling strengths at the top and bottom interfaces. We have then inserted an inorganic tunnel barrier at the bottom interface in order to suppress the spin-dependent hybridization. In this case we restore a positive magnetoresistance. This demonstrates that at the bottom Co/Alq3 interface a stronger coupling occurs which induces an inversion of the spin polarization.

Electric-Field-Induced Magnetization Reversal in a Ferromagnet-Multiferroic Heterostructure

Science.gov (United States)

Heron, J. T.; Trassin, M.; Ashraf, K.; Gajek, M.; He, Q.; Yang, S. Y.; Nikonov, D. E.; Chu, Y.-H.; Salahuddin, S.; Ramesh, R.

2011-11-01

A reversal of magnetization requiring only the application of an electric field can lead to low-power spintronic devices by eliminating conventional magnetic switching methods. Here we show a nonvolatile, room temperature magnetization reversal determined by an electric field in a ferromagnet-multiferroic system. The effect is reversible and mediated by an interfacial magnetic coupling dictated by the multiferroic. Such electric-field control of a magnetoelectric device demonstrates an avenue for next-generation, low-energy consumption spintronics.

High beta plasma operation in a toroidal plasma producing device

International Nuclear Information System (INIS)

Clarke, J.F.

1978-01-01

A high beta plasma is produced in a plasma producing device of toroidal configuration by ohmic heating and auxiliary heating. The plasma pressure is continuously monitored and used in a control system to program the current in the poloidal field windings. Throughout the heating process, magnetic flux is conserved inside the plasma and the distortion of the flux surfaces drives a current in the plasma. As a consequence, the total current increases and the poloidal field windings are driven with an equal and opposing increasing current. The spatial distribution of the current in the poloidal field windings is determined by the plasma pressure. Plasma equilibrium is maintained thereby, and high temperature, high beta operation results

Structure and properties of quarternary and tetragonal Heusler compounds for spintronics and spin transver torque applications

Energy Technology Data Exchange (ETDEWEB)

Zamani, Vajiheh Alijani

2012-03-07

This work is divided into two parts: part 1 is focused on the prediction of half-metallicity in quaternary Heusler compounds and their potential for spintronic applications and part 2 on the structural properties of Mn{sub 2}-based Heusler alloys and tuning the magnetism of them from soft to hard-magnetic for spin-transfer torque applications. In part 1, three different series of quaternary Heusler compounds are investigated, XX'MnGa (X=Cu, Ni and X'=Fe,Co), CoFeMnZ (Z=Al,Ga,Si,Ge), and Co{sub 2-x}Rh{sub x}MnZ (Z=Ga,Sn,Sb). All of these quaternary compounds except CuCoMnGa are predicted to be half-metallic ferromagnets by ab-initio electronic structure calculations. In the XX'MnGa class of compounds, NiFeMnGa has a low Curie temperature for technological applications but NiCoMnGa with a high spin polarization, magnetic moment, and Curie temperature is an interesting new material for spintronics applications. All CoFeMnZ compounds exhibit a cubic Heusler structur and their magnetic moments are in fair agreement with the Slater-Pauling rule indicating the halfmetallicity and high spin polarization required for spintronics applications. Their high Curie temperatures make them suitable for utilization at room temperature and above. The structural investigation revealed that the crystal structure of all Co{sub 2-x}Rh{sub x}MnZ compounds aside from CoRhMnSn exhibit different types of anti-site disorder. The magnetic moments of the disordered compounds deviate from the Slater-Pauling rule indicating that 100% spin polarization are not realized in CoRhMnGa, CoRhMnSb, and Co{sub 0.5}Rh{sub 1.5}MnSb. Exchange of one Co in Co{sub 2}MnSn by Rh results in the stable, well-ordered compound CoRhMnSn. This exchange of one of the magnetic Co atoms by a non-magnetic Rh atom keeps the magnetic properties and half-metallicity intact. In part 2, two series of Mn{sub 2}-based Heusler alloys are investigated, Mn{sub 3-x}Co{sub x}Ga and Mn{sub 2-x}Rh{sub 1+x}Sn. It has been

Performance evaluation of air cleaning devices of an operating low level radioactive solid waste incinerator

International Nuclear Information System (INIS)

Subramanian, V.; Surya Narayana, D.S.; Sundararajan, A.R.; Satyasai, P.M.; Ahmed, Jaleel

1997-01-01

Particle removal efficiencies of a cyclone separator, baghouse filters and a high efficiency particulate activity (HEPA) filter bank of an incinerator have been determined during the incineration of combustible low level solid radioactive wastes with surface dose of 20 - 50 gy/h. Experimental runs have been carried out to collect the particulates in various aerodynamic size ranges using an eight stage Andersen sampler and a low pressure impactor (LPI) while the incinerator is in operation. The collection efficiencies of the cyclone, baghouse and HEPA filters have been found to be 100 per cent for particles of size greater than 4.7, 2.1 and 1.1 μm respectively. The results of our investigations indicate that the air cleaning devices of the incinerator are working according to their design criteria. The data will be useful in the design and operation of air cleaning devices for toxic gaseous effluents. (author). 3 refs., 2 figs., 1 tab

Multilevel Resistance Switching Memory in La2/3Ba1/3MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (011) Heterostructure by Combined Straintronics-Spintronics.

Science.gov (United States)

Zhou, Weiping; Xiong, Yuanqiang; Zhang, Zhengming; Wang, Dunhui; Tan, Weishi; Cao, Qingqi; Qian, Zhenghong; Du, Youwei

2016-03-02

We demonstrate a memory device with multifield switchable multilevel states at room temperature based on the integration of straintronics and spintronics in a La2/3Ba1/3MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) (011) heterostructure. By precisely controlling the electric field applied on the PMN-PT substrate, multiple nonvolatile resistance states can be generated in La2/3Ba1/3MnO3 films, which can be ascribed to the strain-modulated metal-insulator transition and phase separation of Manganite. Furthermore, because of the strong coupling between spin and charge degrees of freedom, the resistance of the La2/3Ba1/3MnO3 film can be readily modulated by magnetic field over a broad temperature range. Therefore, by combining electroresistance and magnetoresistance effects, multilevel resistance states with excellent retention and endurance properties can be achieved at room temperature with the coactions of electric and magnetic fields. The incorporation of ferroelastic strain and magnetic and resistive properties in memory cells suggests a promising approach for multistate, high-density, and low-power consumption electronic memory devices.

High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

Science.gov (United States)

Neu, R.

2006-04-01

In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures.

High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

International Nuclear Information System (INIS)

Neu, R.

2006-01-01

In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures

Device- and system-independent personal touchless user interface for operating rooms : One personal UI to control all displays in an operating room.

Science.gov (United States)

Ma, Meng; Fallavollita, Pascal; Habert, Séverine; Weidert, Simon; Navab, Nassir

2016-06-01

In the modern day operating room, the surgeon performs surgeries with the support of different medical systems that showcase patient information, physiological data, and medical images. It is generally accepted that numerous interactions must be performed by the surgical team to control the corresponding medical system to retrieve the desired information. Joysticks and physical keys are still present in the operating room due to the disadvantages of mouses, and surgeons often communicate instructions to the surgical team when requiring information from a specific medical system. In this paper, a novel user interface is developed that allows the surgeon to personally perform touchless interaction with the various medical systems, switch effortlessly among them, all of this without modifying the systems' software and hardware. To achieve this, a wearable RGB-D sensor is mounted on the surgeon's head for inside-out tracking of his/her finger with any of the medical systems' displays. Android devices with a special application are connected to the computers on which the medical systems are running, simulating a normal USB mouse and keyboard. When the surgeon performs interaction using pointing gestures, the desired cursor position in the targeted medical system display, and gestures, are transformed into general events and then sent to the corresponding Android device. Finally, the application running on the Android devices generates the corresponding mouse or keyboard events according to the targeted medical system. To simulate an operating room setting, our unique user interface was tested by seven medical participants who performed several interactions with the visualization of CT, MRI, and fluoroscopy images at varying distances from them. Results from the system usability scale and NASA-TLX workload index indicated a strong acceptance of our proposed user interface.

Analysis of operations and cyber security policies for a system of cooperating Flexible Alternating Current Transmission System (FACTS) devices.

Energy Technology Data Exchange (ETDEWEB)

Phillips, Laurence R.; Tejani, Bankim; Margulies, Jonathan; Hills, Jason L.; Richardson, Bryan T.; Baca, Micheal J.; Weiland, Laura

2005-12-01

Flexible Alternating Current Transmission Systems (FACTS) devices are installed on electric power transmission lines to stabilize and regulate power flow. Power lines protected by FACTS devices can increase power flow and better respond to contingencies. The University of Missouri Rolla (UMR) is currently working on a multi-year project to examine the potential use of multiple FACTS devices distributed over a large power system region in a cooperative arrangement in which the FACTS devices work together to optimize and stabilize the regional power system. The report describes operational and security challenges that need to be addressed to employ FACTS devices in this way and recommends references, processes, technologies, and policies to address these challenges.

Understanding Electrically Active Interface Formation on Wide Bandgap Semiconductors through Molecular Beam Epitaxy Using Fe3O 4 for Spintronics as a Base Case

Science.gov (United States)

Hamedani Golshan, Negar

Nanoelectronics, complex heterostructures, and engineered 3D matrix materials are quickly advancing from research possibilities to manufacturing challenges for applications ranging from high-power devices to solar cells to any number of novel multifunctional sensors and controllers. Formation of an abrupt and effective interface is one of the basic requirements for integration of functional materials on different types of semiconductors (from silicon to the wide bandgaps) which can significantly impact the functionality of nanoscale electronic devices. To realize the potential of next-generation electronics, the understanding and control of those initial stages of film layer formation must be understood and translated to a process that can control the initial stages of film deposition. Thin film Fe3O4 has attracted much attention as a material for exploring the potential of spintronics in next-generation information technologies. Synthesis of highly spin-polarized material as spin sources, in combination with wide bandgap semiconductors which have a long spin relaxation time in addition to functionality in high-temperature, high-power, and high-frequency environments, would enhance the performance of today's spintronic devices. Spinel ferrite Fe3O4 has a high Curie temperature of 858 K and it is predicted to possess half-metallic properties, i.e. 100% spin polarization at the Fermi level, which can lead to ultrahigh tunneling magnetoresistance at room temperature. However, these properties have been very difficult to realize in thin film form, and device design strategies require high-quality thin films of Fe3O4. The most common reason reported in literature for the failure of the films to achieve theoretical performance is that the growth techniques used today produce films with antiphase boundaries (APB). These APBs have a strong antiferromagnetic coupling that negatively impact the magnetic and transport properties of epitaxial Fe 3O4 films. Therefore, greater

Transmission electron microscopy assessment of conductive-filament formation in Ni-HfO2-Si resistive-switching operational devices

Science.gov (United States)

Martín, Gemma; González, Mireia B.; Campabadal, Francesca; Peiró, Francesca; Cornet, Albert; Estradé, Sònia

2018-01-01

Resistive random-access memory (ReRAM) devices are currently the object of extensive research to replace flash non-volatile memory. However, elucidation of the conductive-filament formation mechanisms in ReRAM devices at nanoscale is mandatory. In this study, the different states created under real operation conditions of HfO2-based ReRAM devices are characterized through transmission electron microscopy and electron energy-loss spectroscopy. The physical mechanism behind the conductive-filament formation in Ni/HfO2/Si ReRAM devices based on the diffusion of Ni from the electrode to the Si substrate and of Si from the substrate to the electrode through the HfO2 layer is demonstrated.

Control rod driving mechanism of reactor, control device and operation method therefor

International Nuclear Information System (INIS)

Ariyoshi, Masahiko; Matsumoto, Fujio; Matsumoto, Koji; Kinugasa, Kunihiko; Nara, Yoshihiko; Otama, Kiyomaro; Mikami, Takao

1998-01-01

The present invention provides a device for and a method of directly driving control rods of an FBR type reactor linearly by a cylinder type linear motor while having a driving shaft as an electric conductor. Namely, a linear induction motor drives a driving shaft connected with a control rod and vertically moving the control rod by electromagnetic force as an electric conductor. The position of the control rod is detected by a position detector. The driving shaft is hung by a wire by way of an electromagnet which is attachably/detachably held. With such a constitution, the driving shaft connected with the control rod can be vertically moved linearly, stopped or kept. Since they can be driven smoothly at a wide range speed, the responsibility and reliability of the reactor operation can be improved. In addition, since responsibility of the control rod operation is high, scram can be conducted by the linear motor. Since the driving mechanism can be simplified, maintenance and inspection operation can be mitigated. (I.S.)

40 CFR 63.3556 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.3556 Section 63.3556... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure.../outlet Concentration Option § 63.3556 How do I establish the emission capture system and add-on control...

Local DER Driven Grid Support by Coordinated Operation of Devices

International Nuclear Information System (INIS)

Warmer, C.J.; Kamphuis, I.G.

2009-01-01

In the traditional operation of electricity networks the system operator has a number of ancillary services available for preservation of system balance. These services are called upon near real-time, after the planning phase. Ancillary services consist of regulating power, reserve capacity and emergency capacity, each with their own characteristics. Regulating power is deployed via load frequency control. Reserve capacity is used to release regulating power and can be called upon to maintain a balance or to counterbalance or resolve transmission restrictions. Both are traded at the Dutch energy market under an auction model with a single buyer (TenneT). Emergency capacity is rewarded on the basis of accessibility/availability within 15 minutes. In local electricity networks neither planning nor ancillary services exist. Planning is done by aggregation into large customer groups. For ancillary services one relies on the system operation as sketched above. In local electricity networks with a large share of distributed generation the costs of keeping the electricity system reliable and stable will increase further and technical problems may arise. The European SmartGrids initiative responds to these challenges in their strategic research agenda. One of the issues addressed in this agenda is the changing role of the distribution grid in which users get a more active role. One opportunity is the introduction of ancillary-type services at the distribution level, utilizing different types of producing and consuming devices in the local network, in order to make the total system more dependable. Distributed generation has a number of characteristics that are similar to characteristics of consumption. Part of it is intermittent / variable, although to a large extent predictable (PV, wind versus lighting, electronic devices). Another part is task-driven (micro-CHP versus electrical heating). Yet another part is controllable or shiftable in time. And storage can behave both

Diagnostics Development towards Steady State Operation in Fusion Devices

Energy Technology Data Exchange (ETDEWEB)

Burhenn, R.; Baldzuhn, J.; Dreier, H.; Endler, M.; Hartfuss, H.J.; Hildebrandt, D.; Hirsch, M.; Koenig, R.; Kornejev, P.; Krychowiak, M.; Laqua, H.P.; Laux, M.; Oosterbeek, J.W.; Pasch, E.; Schneider, W.; Thomsen, H.; Weller, A.; Werner, A.; Wolf, R.; Zhang, D. [Max-Planck-Institute fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Biel, W. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich GmbH EURATOM Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany)

2011-07-01

The stellarator Wendelstein 7-X (W7-X) is being presently under construction and is already equipped with superconducting coil systems and principally is capable of quasi-continuous operation. However, W7-X is faced with new enhanced technical requirements which have to be met by plasma facing components as well as the diagnostic systems in general. Depending on the available heating power, the continuous heat flux to plasma facing components during long pulse operation might lead to unacceptable local thermal overload and necessitates sufficient but often complicate active cooling precautions. Fusion devices with electron cyclotron frequency heating (ECRH) are concerned with significant stray radiation, depending on the chosen heating scheme and the plasma parameters. The required shielding is often not compatible with optimal UHV-consistent design and high intensity throughput. For machine safety, diagnostics are required which are able to identify enhanced plasma wall interaction on a fast time scale in order to prevent damage in time. For W7-X, video camera systems covering most of the inner wall, fast IR-camera systems with coating-resistant pinhole-optics for the observation of the divertor surface temperature and spectrometers with large spectral survey covering relevant spectral lines of all intrinsic impurities with sufficient spectral resolution and sensitivity are necessary. In combination with energy integrating but spatially resolving diagnostics like bolometers and soft-X cameras slow impurity accumulation phenomena on a time scale much larger than flat-top times typically achieved in short-pulse operation can be identified and a radiative plasma collapse possibly be avoided by counteractive measures. Longer port dimensions due to thermal insulation of the cryogenic coil system and high density operation with strong density gradients necessitate the choice of shorter wavelengths for interferometer laser beams. This complicates the avoidance of fringe

Reliability and efficiency upgrades of power systems operation by implementing intelligent electronic devices with synchrophasor measurement technology support

OpenAIRE

Mokeev Alexey

2017-01-01

This paper reviews issues of reliability and efficiency upgrades of power systems functions by means of a widespread implementation of intelligent electronic devices (IED) in various purposes supporting synchrophasor measurement technology. Thus, such issues as IED’s operational analysis in the conditions of electromagnetic and electromechanical transient processes and synthesis of digital filters that improve static and dynamic responses of these devices play an important role in their devel...

The insertion device magnetic measurement facility: Prototype and operational procedures

International Nuclear Information System (INIS)

Burkel, L.; Dejus, R.; Maines, J.; O'Brien, J.; Vasserman, I.; Pfleuger, J.

1993-03-01

This report is a description of the current status of the magnetic measurement facility and is a basic instructional manual for the operation of the facility and its components. Please refer to the appendices for more detailed information about specific components and procedures. The purpose of the magnetic measurement facility is to take accurate measurements of the magnetic field in the gay of the IDs in order to determine the effect of the ID on the stored particle beam and the emitted radiation. The facility will also play an important role when evaluating new ideas, novel devices, and inhouse prototypes as part of the ongoing research and development program at the APS. The measurements will be performed with both moving search coils and moving Hall probes. The IDs will be evaluated by computer modeling of the emitted radiation for any given (measured) magnetic field map. The quality of the magnetic field will be described in terms of integrated multipoles for the effect on Storage Ring performance and in terms of the derived trajectories for the emitted radiation. Before being installed on the Storage Ring, every device will be measured and characterized to assure that it is compatible with Storage Ring requirements and radiation specifications. The accuracy that the APS needs to achieve for magnetic measurements will be based on these specifications

Device-Centric Monitoring for Mobile Device Management

Directory of Open Access Journals (Sweden)

Luke Chircop

2016-03-01

Full Text Available The ubiquity of computing devices has led to an increased need to ensure not only that the applications deployed on them are correct with respect to their specifications, but also that the devices are used in an appropriate manner, especially in situations where the device is provided by a party other than the actual user. Much work which has been done on runtime verification for mobile devices and operating systems is mostly application-centric, resulting in global, device-centric properties (e.g. the user may not send more than 100 messages per day across all applications being difficult or impossible to verify. In this paper we present a device-centric approach to runtime verify the device behaviour against a device policy with the different applications acting as independent components contributing to the overall behaviour of the device. We also present an implementation for Android devices, and evaluate it on a number of device-centric policies, reporting the empirical results obtained.

Carbon nanotubes for coherent spintronics

DEFF Research Database (Denmark)

Kuemmeth, Ferdinand; Churchill, H O H; Herring, P K

2010-01-01

Carbon nanotubes bridge the molecular and crystalline quantum worlds, and their extraordinary electronic, mechanical and optical properties have attracted enormous attention from a broad scientific community. We review the basic principles of fabricating spin-electronic devices based on individual......, electrically-gated carbon nanotubes, and present experimental efforts to understand their electronic and nuclear spin degrees of freedom, which in the future may enable quantum applications....

Battery-operated, portable, and flexible air microplasma generation device for fabrication of microfluidic paper-based analytical devices on demand.

Science.gov (United States)

Kao, Peng-Kai; Hsu, Cheng-Che

2014-09-02

A portable microplasma generation device (MGD) operated in ambient air is introduced for making a microfluidic paper-based analytical device (μPAD) that serves as a primary healthcare platform. By utilizing a printed circuit board fabrication process, a flexible and lightweight MGD can be fabricated within 30 min with ultra low-cost. This MGD can be driven by a portable power supply (less than two pounds), which can be powered using 12 V-batteries or ac-dc converters. This MGD is used to perform maskless patterning of hydrophilic patterns with sub-millimeter spatial resolution on hydrophobic paper substrates with good pattern transfer fidelity. Using this MGD to fabricate μPADs is demonstrated. With a proper design of the MGD electrode geometry, μPADs with 500-μm-wide flow channels can be fabricated within 1 min and with a cost of less than $USD 0.05/device. We then test the μPADs by performing quantitative colorimetric assay tests and establish a calibration curve for detection of glucose and nitrite. The results show a linear response to a glucose assay for 1-50 mM and a nitrite assay for 0.1-5 mM. The low cost, miniaturized, and portable MGD can be used to fabricate μPADs on demand, which is suitable for in-field diagnostic tests. We believe this concept brings impact to the field of biomedical analysis, environmental monitoring, and food safety survey.

Sharing data between mobile devices, connected vehicles and infrastructure - task 3: concept of operations : technical memorandum -final.

Science.gov (United States)

2016-07-13

This report describes the concept of operation for the use of mobile devices in a connected vehicle environment. Specifically, it identifies the needs, conceptual system, and potential scenarios that serve as the basis for demonstrating both safety a...

Reliability and efficiency upgrades of power systems operation by implementing intelligent electronic devices with synchrophasor measurement technology support

Directory of Open Access Journals (Sweden)

Mokeev Alexey

2017-01-01

Full Text Available This paper reviews issues of reliability and efficiency upgrades of power systems functions by means of a widespread implementation of intelligent electronic devices (IED in various purposes supporting synchrophasor measurement technology. Thus, such issues as IED’s operational analysis in the conditions of electromagnetic and electromechanical transient processes and synthesis of digital filters that improve static and dynamic responses of these devices play an important role in their development.

Nonconformance in electromechanical output relays of microprocessor-based protection devices under actual operating conditions

OpenAIRE

Gurevich, Vladimir

2006-01-01

Microprocessor-based protection relays are gradually driving out traditional electromechanical and even electronic protection devices from virtually all fields of power and electrical engineering. In this paper, one of many problems of microprocessor-based relays is discussed: nonconformance of miniature electromechanical output relays under actual operation conditions: switching inductive loads (with tripping CB coils or lockout relay coils) at 220 VDC, and "dry" switching of some control ci...

Challenges and opportunities with spin-based logic

Science.gov (United States)

Perricone, Robert; Niemier, Michael; Hu, X. Sharon

2017-09-01

In this paper, we provide a short overview of efforts to process information with spin as a state variable. We highlight initial efforts in spintronics where devices concepts such as spinwaves, field coupled nanomagnets, etc. were are considered as vehicles for processing information. We also highlight more recent work where spintronic logic and memory devices are considered in the context of information processing hardware for the internet of things (IoT), and where the ability to constantly "checkpoint" processor state can support computing in environments with unreliable power supplies.

High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

Science.gov (United States)

Galanakis, I.

2015-03-01

Half-metallic Co2MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co2MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co2MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices.

P-type zinc oxide spinels: application to transparent conductors and spintronics

International Nuclear Information System (INIS)

Stoica, Maria; S Lo, Cynthia

2014-01-01

We report on the electronic and optical properties of two theoretically predicted stable spinel compounds of the form ZnB 2 O 4 , where B = Ni or Cu; neither compound has been previously synthesized, so we compare them to the previously studied p-type ZnCo 2 O 4 spinel. These new materials exhibit spin polarization, which is useful for spintronics applications, and broad conductivity maxima near the valence band edge that indicate good p-type dopability. We show that 3d electrons on the octahedrally coordinated Zn atom fall deep within the valence band and do not contribute significantly to the electronic structure near the band edge of the material, while the O 2p and tetrahedrally coordinated B 3d electrons hybridize broadly in the shallow valence states, resulting in increasing curvature (i.e., decreased electron effective mass) of valence bands near the band edge. In particular, ZnCu 2 O 4 exhibits high electrical conductivities in the p-doping region near the valence band edge that, at σ=2×10 4  S cm −1 , are twice the maximum found for ZnCo 2 O 4 , a previously synthesized compound in this class of materials. This material also exhibits ferromagnetism in all of its most stable structures, which makes it a good candidate for further study as a dilute magnetic semiconductor. (paper)

Cost and Information Effectiveness Analysis (CIEA): A Methodology for Evaluating a Training Device Operational Readiness Assessment Capability (DORAC).

Science.gov (United States)

1981-02-01

Report 528 COST AIND I*FO•?JidTH ?i EFFECT•• ES1BS ANALYSIS (CDEA): A METiBLOBU Y FOR EVALUATIN1G A TRAINING DEMCE OPERATMDN1AL MAEA3 ],SE 3SSESS$ iElT ...8217, N. Within a military setting, the uses of training devices in performance evaluation have generally mirrored civilian uses and primarily...Technical Report 528 COST AND INFORMATION EFFECTIVENESS ANALYSIS (CIEA): A METHODOLOGY FOR EVALUATING A TRAINING DEVICE OPERATIONAL READINESS

[Innovation of characteristic medicinal cupping devices].

Science.gov (United States)

Li, Jianping; Zhang, Hui; Yang, Jianmei; Xu, Xinchun; Niu, Yanxia; Cai, Jun

2015-08-01

To compare the differences in the characteristic medicinal cupping therapy between the traditional cupping device and the innovated cupping device. Fifty patients of neck and low back pain were selected. The self-comparison was adopted. The cupping therapy was applied to the acupoints located on the left or right side with the traditional cupping device and the innovated cupping device. The cupping sites were centered at bilateral Quyuan (SI 13) and Dachangshu (BL 25). The cups were retained for 10 min. The traditional cupping device was the glass with smooth border, 100mL. The innovated cupping device was the vacuum-sucking cup. The operative time, medicinal leakage, comfort and cupping marks were observed for the two different cupping devices. The operative time with the innovated medicinal cupping device was shorter obviously compared with the traditional one at Quyuan (SI 13) and Dachangshu (BL 25, both Pcupping device was remarkably improved as compared with the traditional one at the two acupoints (both Pcupping operation (both P>0. 05). The cupping marks with the innovated medicinal cupping device were much deeper than those with the traditional one after cupping therapy. The innovated cupping device is more convenent and comfortable in operation during the characteristic medicinal cupping therapy.

Nanoscale Device Properties of Tellurium-based Chalcogenide Compounds

Science.gov (United States)

Dahal, Bishnu R.

The great progress achieved in miniaturization of microelectronic devices has now reached a distinct bottleneck, as devices are starting to approach the fundamental fabrication and performance limit. Even if a major breakthrough is made in the fabrication process, these scaled down electronic devices will not function properly since the quantum effects can no longer be neglected in the nanoscale regime. Advances in nanotechnology and new materials are driving novel technologies for future device applications. Current microelectronic devices have the smallest feature size, around 10 nm, and the industry is planning to switch away from silicon technology in the near future. The new technology will be fundamentally different. There are several leading technologies based on spintronics, tunneling transistors, and the newly discovered 2-dimensional material systems. All of these technologies are at the research level, and are far from ready for use in making devices in large volumes. This dissertation will focus on a very promising material system, Te-based chalcogenides, which have potential applications in spintronics, thermoelectricity and topological insulators that can lead to low-power-consumption electronics. Very recently it was predicted and experimentally observed that the spin-orbit interaction in certain materials can lead to a new electronic state called topological insulating phase. The topological insulator, like an ordinary insulator, has a bulk energy gap separating the highest occupied electronic band from the lowest empty band. However, the surface states in the case of a three-dimensional or edge states in a two-dimensional topological insulator allow electrons to conduct at the surface, due to the topological character of the bulk wavefunctions. These conducting states are protected by time-reversal symmetry, and cannot be eliminated by defects or chemical passivation. The edge/surface states satisfy Dirac dispersion relations, and hence the physics

Magnetic Fusion Energy Plasma Interactive and High Heat Flux Components: Volume 5, Technical assessment of critical issues in the steady state operation of fusion confinement devices

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

Critical issues for the steady state operation of plasma confinement devices exist in both the physics and technology fields of fusion research. Due to the wide range and number of these issues, this technical assessment has focused on the crucial issues associated with the plasma physics and the plasma interactive components. The document provides information on the problem areas that affect the design and operation of a steady state ETR or ITER type confinement device. It discusses both tokamaks and alternative concepts, and provides a survey of existing and planned confinement machines and laboratory facilities that can address the identified issues. A universal definition of steady state operation is difficult to obtain. From a physics point of view, steady state is generally achieved when the time derivatives approach zero and the operation time greatly exceeds the characteristic time constants of the device. Steady state operation for materials depends on whether thermal stress, creep, fatigue, radiation damage, or power removal are being discussed. For erosion issues, the fluence and availability of the machine for continuous operation are important, assuming that transient events such as disruptions do not limit the component lifetimes. The panel suggests, in general terms, that steady state requires plasma operation from 100 to 1000 seconds and an availability of more than a few percent, which is similar to the expectations for an ETR type device. The assessment of critical issues for steady state operation is divided into four sections: physics issues; technology issues; issues in alternative concepts; and devices and laboratory facilities that can address these problems.

Magnetic Fusion Energy Plasma Interactive and High Heat Flux Components: Volume 5, Technical assessment of critical issues in the steady state operation of fusion confinement devices

International Nuclear Information System (INIS)

1988-01-01

Critical issues for the steady state operation of plasma confinement devices exist in both the physics and technology fields of fusion research. Due to the wide range and number of these issues, this technical assessment has focused on the crucial issues associated with the plasma physics and the plasma interactive components. The document provides information on the problem areas that affect the design and operation of a steady state ETR or ITER type confinement device. It discusses both tokamaks and alternative concepts, and provides a survey of existing and planned confinement machines and laboratory facilities that can address the identified issues. A universal definition of steady state operation is difficult to obtain. From a physics point of view, steady state is generally achieved when the time derivatives approach zero and the operation time greatly exceeds the characteristic time constants of the device. Steady state operation for materials depends on whether thermal stress, creep, fatigue, radiation damage, or power removal are being discussed. For erosion issues, the fluence and availability of the machine for continuous operation are important, assuming that transient events such as disruptions do not limit the component lifetimes. The panel suggests, in general terms, that steady state requires plasma operation from 100 to 1000 seconds and an availability of more than a few percent, which is similar to the expectations for an ETR type device. The assessment of critical issues for steady state operation is divided into four sections: physics issues; technology issues; issues in alternative concepts; and devices and laboratory facilities that can address these problems

Transcatheter closure of post-operative residual ventricular septal defect using a patent ductus arteriosus closure device in an adult: a case report.

Science.gov (United States)

Djer, Mulyadi M; Idris, Nikmah S; Alwi, Idrus; Wijaya, Ika P

2014-07-01

Transcatheter closure of perimembranous and muscular ventricular septal defect (VSD) has been performed widely and it has more advantages compare to surgery. However, transcatheter closure of residual VSD post operation of complex congenital heart disease is still challenging because of the complexity of anatomy and concern about device stability, so the operator should meticulously choose the most appropriate technique and device. We would like to report a case of transcatheter closure of residual VSD post Rastelli operation in a patient with double outlet right ventricle (DORV), sub-aortic VSD, severe infundibulum pulmonary stenosis (PS) and single coronary artery. The patient had undergone operations for four times, but he still had intractable heart failure that did not response to medications. On the first attempt. we closed the VSD using a VSD occluder, unfortunately the device embolized into the descending aorta, but fortunately we was able to snare it out. Then we decided to close the VSD using a patent ductus arteriosus (PDA occluder). On transesophageal echocardiography (TEE) and angiography evaluation, the device position was stable. Post transcatheter VSD closure, the patient clinical condition improved significantly and he could finally be discharged after a long post-surgery hospitalization. Based on this experience we concluded that the transcatheter closure of residual VSD in complex CHD using PDA occluder could be an effective alternative treatment.

Operational amplifiers

CERN Document Server

Dostal, Jiri

1993-01-01

This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

Digital device for synchronous storage

International Nuclear Information System (INIS)

Kobzar', Yu.M.; Kovtun, V.G.; Pashechko, N.I.

1991-01-01

Synchronous storage digital device for IR electron-photon emission spectrometer operating with analogue-to-digital converter F4223 or monocrystal converter K572PV1 is described. The device accomplished deduction of noise-background in each storage cycle. Summation and deduction operational time equals 90 ns, device output code discharge - 20, number of storages -2 23

Compound semiconductor device modelling

CERN Document Server

Miles, Robert

1993-01-01

Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

Guide device

International Nuclear Information System (INIS)

Brammer, C.M. Jr.

1977-01-01

Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures

Nanoscale observations of the operational failure for phase-change-type nonvolatile memory devices using Ge2Sb2Te5 chalcogenide thin films

International Nuclear Information System (INIS)

Yoon, Sung-Min; Choi, Kyu-Jeong; Lee, Nam-Yeal; Lee, Seung-Yun; Park, Young-Sam; Yu, Byoung-Gon

2007-01-01

In this study, a phase-change memory device was fabricated and the origin of device failure mode was examined using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Ge 2 Sb 2 Te 5 (GST) was used as the active phase-change material in the memory device and the active pore size was designed to be 0.5 μm. After the programming signals of more than 2x10 6 cycles were repeatedly applied to the device, the high-resistance memory state (reset) could not be rewritten and the cell resistance was fixed at the low-resistance state (set). Based on TEM and EDS studies, Sb excess and Ge deficiency in the device operating region had a strong effect on device reliability, especially under endurance-demanding conditions. An abnormal segregation and oxidation of Ge also was observed in the region between the device operating and inactive peripheral regions. To guarantee an data endurability of more than 1x10 10 cycles of PRAM, it is very important to develop phase-change materials with more stable compositions and to reduce the current required for programming

Observations on the reliability of COTS-device-based solid state data recorders operating in low-earth orbit

International Nuclear Information System (INIS)

Underwood, C.I.

1999-01-01

This paper presents the results of Surrey Space Centre's experience in using different coding schemes and hardware configurations to protect data and protect data and software stored in COTS-device (Commercial-Off-The-Shelf) based memories on-board operational spacecraft in low Earth orbit. (author)

New spintronic superlattices composed of half-metallic compounds with zinc-blende structure

International Nuclear Information System (INIS)

Fong, C Y; Qian, M C

2004-01-01

The successful growth of zinc-blende half-metallic compounds, namely CrAs and CrSb, in thin film forms offers a new direction to search for novel spintronic materials. By using a well documented first-principles algorithm, the VASP code, we predict the electronic and magnetic properties of superlattices made of these exciting half-metallic materials. Not only are the superlattices constructed with two of the half-metallic compounds (CrAs/MnAs) but also they are modelled to combine with both a III-V (GaAs-MnAs/CrAs/GaAs) and a IV-IV (MnC/SiC) semiconductor. We investigate variable thicknesses for the combinations. For every case, we find the equilibrium lattice constant as well as the lattice constant at which the superlattice exhibits the half-metallic properties. For CrAs/MnAs, the half-metallic properties are presented and the magnetic moments are shown to be the sum of the moments for MnAs and CrAs. The half-metallic properties of GaAs-MnAs/CrAs/GaAs are found to be crucially dependent on the completion of the d-p hybridization. The magnetic properties of MnC/SiC are discussed with respect to the properties of MnC

7. IAEA Technical Meeting on Steady State Operation of Magnetic Fusion Devices - Booklet of abstracts

International Nuclear Information System (INIS)

2015-01-01

This meeting has provided an appropriate forum to discuss current issues covering a wide range of technical topics related to the steady state operation issues and also to encourage forecast of the ITER performances. The technical meeting includes invited and contributed papers. The topics that have been dealt with are: 1) Superconducting devices (ITER, KSTAR, Tore-Supra, HT-7U, EAST, LHD, Wendelstein-7-X,...); 2) Long-pulse operation and advanced tokamak physics; 3) steady state fusion technologies; 4) Long pulse heating and current drive; 5) Particle control and power exhaust, and 6) ITER-related research and development issues. This document gathers the abstracts

Remote operation system for container

International Nuclear Information System (INIS)

Nakahara, Hirotaka; Hayata, Takashi; Kajiyama, Shigeru; Takahashi, Fuminobu

1998-01-01

The present invention provides a remote operation system for conducting operation with operation reaction for the inside of a container filled with water (liquid), such as of inner walls and inner structural materials of a BWR type reactor. Namely, a swimming robot comprises a swimming device swimming in the liquid and an attaching/detaching device for holding/releasing the handling robot. A control device remotely operate the swimming robot and the handling robot by way of a cable. A cable processing device takes up or dispenses the cable. In addition, when the swimming robot grasps the handling robot by the attaching/detaching device, the swimming robot transmits an operation instruction sent from the control device by way of the cable to the handling robot. After the attaching/detaching device of the swimming robot releases the handling robot, the handling robot operates based on the transmitted operation instruction. It is preferable that the handling robot has an adsorptive moving device for moving itself while being adsorbed on the wall surface of the container. (I.S.)

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

Science.gov (United States)

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-21

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

The role of the hole-extraction layer in determining the operational stability of a polycarbazole:fullerene bulk-heterojunction photovoltaic device

Science.gov (United States)

Bovill, E.; Scarratt, N.; Griffin, J.; Yi, H.; Iraqi, A.; Buckley, A. R.; Kingsley, J. W.; Lidzey, D. G.

2015-02-01

We have made a comparative study of the relative operational stability of bulk-heterojunction organic photovoltaic (OPV) devices utilising different hole transport layers (HTLs). OPV devices were fabricated based on a blend of the polymer PCDTBT with the fullerene PC70BM, and incorporated the different HTL materials PEDOT:PSS, MoOx and V2O5. Following 620 h of irradiation by light from a solar simulator, we find that devices using the PEDOT:PSS HTL retained the highest efficiency, having a projected T80 lifetime of 14 500 h.

Collective processing device for spent fuel

International Nuclear Information System (INIS)

Irie, Hiroaki; Taniguchi, Noboru.

1996-01-01

The device of the present invention comprises a sealing vessel, a transporting device for transporting spent fuels to the sealing vessel, a laser beam cutting device for cutting the transported spent fuels, a dissolving device for dissolving the cut spent fuels, and a recovering device for recovering radioactive materials from the spent fuels during processing. Reprocessing treatments comprising each processing of dismantling, shearing and dissolving are conducted in the sealing vessel can ensure a sealing barrier for the radioactive materials (fissionable products and heavy nuclides). Then, since spent fuels can be processed in a state of assemblies, and the spent fuels are easily placed in the sealing vessel, operation efficiency is improved, as well as operation cost is saved. Further, since the spent fuels can be cut by a remote laser beam operation, there can be prevented operator's exposure due to radioactive materials released from the spent fuels during cutting operation. (T.M.)

14 CFR 91.21 - Portable electronic devices.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Portable electronic devices. 91.21 Section... electronic devices. (a) Except as provided in paragraph (b) of this section, no person may operate, nor may any operator or pilot in command of an aircraft allow the operation of, any portable electronic device...

Utilization technique on variable speed device

International Nuclear Information System (INIS)

1989-12-01

This reports of workshop on power technology describes using technique on variable speed device, which deals with alternating current situation and prospect of current variable speed device, technical trend and prospect of electronics, reduce expenses by variable speed device, control technique, measurement technology, high voltage variable speed device, recent trend of inverter technology, low voltage and high voltage variable speed device control device, operating variable speed device in cooling fan, FDF application and defect case of variable speed device, cooling pump application of water variable transformer, inverter application and energy effect of ventilation equipment, application of variable speed device and analysis of the result of operation and study for application of variable speed technology.

40 CFR 63.4966 - How do I establish the emission capture system and add-on control device operating limits during...

Science.gov (United States)

2010-07-01

... system and add-on control device operating limits during the performance test? 63.4966 Section 63.4966... outlet gas temperature is the maximum operating limit for your condenser. (e) Emission capture system... with Add-on Controls Option § 63.4966 How do I establish the emission capture system and add-on control...

Pressurized waterproof case electronic device

KAUST Repository

Berumen, Michael L.

2013-01-31

A pressurized waterproof case for an electronic device is particularly adapted for fluid-tight containment and operation of a touch-screen electronic device or the like therein at some appreciable water depth. In one example, the case may be formed as an enclosure having an open top panel or face covered by a flexible, transparent membrane or the like for the operation of the touchscreen device within the case. A pressurizing system is provided for the case to pressurize the case and the electronic device therein to slightly greater than ambient in order to prevent the external water pressure from bearing against the transparent membrane and pressing it against the touch screen, thereby precluding operation of the touch screen device within the case. The pressurizing system may include a small gas cartridge or may be provided from an external source.

Highly Efficient Spin-Current Operation in a Cu Nano-Ring

Science.gov (United States)

Murphy, Benedict A.; Vick, Andrew J.; Samiepour, Marjan; Hirohata, Atsufumi

2016-11-01

An all-metal lateral spin-valve structure has been fabricated with a medial Copper nano-ring to split the diffusive spin-current path. We have demonstrated significant modulation of the non-local signal by the application of a magnetic field gradient across the nano-ring, which is up to 30% more efficient than the conventional Hanle configuration at room temperature. This was achieved by passing a dc current through a current-carrying bar to provide a locally induced Ampère field. We have shown that in this manner a lateral spin-valve gains an additional functionality in the form of three-terminal gate operation for future spintronic logic.

Electrowetting-based microfluidic operations on rapid-manufactured devices for heat pipe applications

Science.gov (United States)

Hale, Renee S.; Bahadur, Vaibhav

2017-07-01

The heat transport capacity of traditional heat pipes is limited by the capillary pressure generated in the internal wick that pumps condensate to the evaporator. Recently, the authors conceptualized a novel heat pipe architecture, wherein wick-based pumping is replaced by electrowetting (EW)-based pumping of microliter droplets in the adiabatic section. An electrowetting heat pipe (EHP) can overcome the capillary limit to heat transport capacity and enable compact, planar, gravity-insensitive, and ultralow power consumption heat pipes that transport kiloWatt heat loads over extended distances. This work develops a novel technique for rapid, scalable fabrication of EW-based devices and studies critical microfluidic operations underlying the EHP, with the objective of predicting the key performance parameters of the EHP. Devices are fabricated on a printed circuit board (PCB) substrate with mechanically-milled electrodes, and a removable polyimide dielectric film. The first set of experiments uncovers the maximum channel gap (1 mm) for reliable EW-based pumping; this parameter determines the heat transport capacity of the EHP, which scales linearly with the channel gap. The second set of experiments uncovers the maximum channel gap (375 microns) at which EW voltages can successfully split droplets. This is an important consideration which ensures EHP operability in the event of unintentional droplet merging. The third set of experiments demonstrate and study EW-induced droplet generation from an open-to-air reservoir, which mimics the interface between the condenser and adiabatic sections of the EHP. The experimental findings predict that planar, water-based EHPs with a (10 cm by 4 mm) cross section can transport 1.6 kW over extended distances (>1 m), with a thermal resistance of 0.01 K W-1.

Human Factors and Medical Devices

International Nuclear Information System (INIS)

Dick Sawyer

1998-01-01

Medical device hardware- and software-driven user interfaces should be designed to minimize the likelihood of use-related errors and their consequences. The role of design-induced errors in medical device incidents is attracting widespread attention. The U.S. Food and Drug Administration (FDA) is fully cognizant that human factors engineering is critical to the design of safe medical devices, and user interface design is receiving substantial attention by the agency. Companies are paying more attention to the impact of device design, including user instructions, upon the performance of those health professionals and lay users who operate medical devices. Concurrently, the FDA is monitoring human factors issues in its site inspections, premarket device approvals, and postmarket incident evaluations. Overall, the outlook for improved designs and safer device operation is bright

On the temperature dependence of spin pumping in ferromagnet–topological insulator–ferromagnet spin valves

Directory of Open Access Journals (Sweden)

A.A. Baker

Full Text Available Topological insulators (TIs have a large potential for spintronic devices owing to their spin-polarized, counter-propagating surface states. Recently, we have investigated spin pumping in a ferromagnet–TI–ferromagnet structure at room temperature. Here, we present the temperature-dependent measurement of spin pumping down to 10 K, which shows no variation with temperature. Keywords: Topological insulator, Spin pumping, Spintronics, Ferromagnetic resonance

From supramolecular electrochemistry to molecular-level devices

Energy Technology Data Exchange (ETDEWEB)

Credi, Alberto; Ferrer Ribera, Belen; Venturi, Margherita

2004-09-15

Supramolecular (multi-component) systems can perform complex functions which result from the cooperation of actions performed by suitably selected molecular components. Looking at supramolecular systems, from the viewpoint of the functions, shows that the concept of macroscopic device can be extended to molecular level. Nature exploits very complex molecular-level devices to substain life, and, in the last twenty years, the development of supramolecular chemistry has allowed the construction of simple molecular-level devices, that are of interest not only for basic research, but also for the growth of nanoscience and nanotechnology. Molecular-level devices operate via electronic and/or nuclear rearrangements, and like macroscopic devices, they need energy to operate and signals to communicate with the operator. Electrochemistry can provide the answer to this dual requirement, since electrons/holes, besides supplying the energy needed to make a devices work, can also be useful to 'read' the state of the system and thus to control and monitor the operation of the device. In this article, some examples of molecular-level devices investigated in our laboratory will be reviewed.

Is the bipolar vessel sealer device an effective tool in robotic surgery? A retrospective analysis of our experience and a meta-analysis of the literature about different robotic procedures by investigating operative data and post-operative course.

Science.gov (United States)

Ortenzi, Monica; Ghiselli, Roberto; Baldarelli, Maddalena; Cardinali, Luca; Guerrieri, Mario

2018-04-01

The latest robotic bipolar vessel sealing tools have been described to be effective allowing to perform procedures with reduced blood loss and shorter operative times. The aim of this study was to assess the efficacy and reliability of these devices applied in different robotic procedures. All robotic operations, between 2014 and 2016, were performed using the EndoWrist One VesselSealer (EWO, Intuitive Surgical, Sunnyvale, CA), a bipolar fully wristed device. Data, including age, gender, body mass index (BMI), were collected. Robot docking time, intraoperative blood loss, robot malfunctioning and overall operative time were analyzed. A meta-analysis of the literature was carried out to point the attention to three different parameters (mean blood loss, operating time and hospital stay) trying to identify how different coagulation devices may affect them. In 73 robotic procedures, the mean operative time was 118.2 minutes (75-125 minutes). Mean hospital stay was four days (2-10 days). There were two post-operative complications (2.74%). The bipolar vessel sealer offers the efficacy of bipolar diathermy and the advantages of a fully wristed instrument. It does not require any change of instruments for coagulation or involvement of the bedside assistant surgeon. These characteristics lead to a reduction in operative time.

Spacer type mediated tunable spin crossover (SCO) characteristics of pyrene decorated 2,6-bis(pyrazol-1-yl)pyridine (bpp) based Fe(ii) molecular spintronic modules.

Science.gov (United States)

Kumar, Kuppusamy Senthil; Šalitroš, Ivan; Moreno-Pineda, Eufemio; Ruben, Mario

2017-08-14

A simple "isomer-like" variation of the spacer group in a set of Fe(ii) spin crossover (SCO) complexes designed to probe spin state dependence of electrical conductivity in graphene-based molecular spintronic junctions led to the observation of remarkable variations in the thermal- and light-induced magnetic characteristics, paving a simple route for the design of functional SCO complexes with different temperature switching regimes based on a 2,6-bis(pyrazol-1-yl)pyridine ligand skeleton.

Operation and control of an ion-implantation/sputtering storage device for 85Kr

International Nuclear Information System (INIS)

McClanahan, E.D.; Moss, R.W.; Greenwell, E.N.

1986-01-01

The design and operation of a device for implanting 85 Kr in a sputtered Cu-Y alloy for long-term storage tests are described. A total of approx.400 Ci of 85 Kr, in a 4.2% mixture with nonradioactive isotopes, was implanted in three batches at a rate of 6.1 sccm. A triode discharge operating at a pressure of 0.4 Pa with a plasma current of 4.5 A was maintained with a potential of 67 V. The target and substrate potentials were 2400 and 290, respectively, with an ion current density of approx.100 A/m 2 . The discharge and pumping action was started with nonradioactive Kr, then was switched to the radioactive gas until all in the reservoir was consumed, then again was switched to the nonradioactive gas to apply a closeout layer. The control feature used made it possible to empty the 85 Kr reservoir without use of an auxiliary pumping system. 13 refs., 4 figs

DOE-EPSCoR Final Report Period: September 1, 2008- August 31, 2016

Energy Technology Data Exchange (ETDEWEB)

Katiyar, Ram [Univ. of Puerto Rico, Rio Piedras, PR (United States); Gomez, M. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Morell, G. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Fonseca, L. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Ishikawa, Y. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Palai, R. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Thomas, R. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Kumar, A. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Velev, J. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Makarov, V. [Univ. of Puerto Rico, Rio Piedras, PR (United States); Perales, O. [Univ. of Puerto Rico, Mayaguez, PR (United States); Tomar, M. S. [Univ. of Puerto Rico, Mayaguez, PR (United States); Otano, W. [Univ. of Puerto Rico, Cayey, PR (United States)

2016-10-31

In this project, multifunctional nanostructured spintronic and magnetoelectric materials were investigated by experimental and computational efforts for applications in energy efficient electronic systems that integrate functionalities and thus have the potential to enable a new generation of faster responding devices and increased integration densities. The team systematically investigated transition metal (TM)-doped ZnO nanostructures, silicide nanorods, magnetoelectric oxides, and ferroelectric/ferromagnetic heterostructures. In what follows, we report the progress made by researchers during the above period in developing and understanding of 1) Spintronics nanostructures; 2) Resistive switching phenomenon in oxides for memory devices; 3) Magnetoelectric multiferroics; 4) Novel high-k gate oxides for logic devices; 5) Two dimensional (2D) materials; and 6) Theoretical studies in the above fields.

DOE-EPSCoR Final Report Period: September 1, 2008- August 31, 2016

International Nuclear Information System (INIS)

Katiyar, Ram; Gomez, M.; Morell, G.; Fonseca, L.; Ishikawa, Y.; Palai, R.; Thomas, R.; Kumar, A.; Velev, J.; Makarov, V.; Perales, O.; Tomar, M. S.; Otano, W.

2016-01-01

In this project, multifunctional nanostructured spintronic and magnetoelectric materials were investigated by experimental and computational efforts for applications in energy efficient electronic systems that integrate functionalities and thus have the potential to enable a new generation of faster responding devices and increased integration densities. The team systematically investigated transition metal (TM)-doped ZnO nanostructures, silicide nanorods, magnetoelectric oxides, and ferroelectric/ferromagnetic heterostructures. In what follows, we report the progress made by researchers during the above period in developing and understanding of 1) Spintronics nanostructures; 2) Resistive switching phenomenon in oxides for memory devices; 3) Magnetoelectric multiferroics; 4) Novel high-k gate oxides for logic devices; 5) Two dimensional (2D) materials; and 6) Theoretical studies in the above fields.

Reactor core control device

International Nuclear Information System (INIS)

Sano, Hiroki

1998-01-01

The present invention provides a reactor core control device, in which switching from a manual operation to an automatic operation, and the control for the parameter of an automatic operation device are facilitated. Namely, the hysteresis of the control for the operation parameter by an manual operation input means is stored. The hysteresis of the control for the operation parameter is collected. The state of the reactor core simulated by an operation control to which the collected operation parameters are manually inputted is determined as an input of the reactor core state to the automatic input means. The record of operation upon manual operation is stored as a hysteresis of control for the operation parameter, but the hysteresis information is not only the result of manual operation of the operation parameter. This is results of operation conducted by a skilled operator who judge the state of the reactor core to be optimum. Accordingly, it involves information relevant to the reactor core state. Then, it is considered that the optimum automatic operation is not deviated greatly from the manual operation. (I.S.)

Incore inspection and repairing device

International Nuclear Information System (INIS)

Ito, Arata; Kimura, Motohiko

1998-01-01

The present invention provides a device for inspecting and repairing the inside of a reactor container even if it is narrow, with no trouble by using a swimming-type operation robot. Namely, the device of the present invention conducts inspection and repairing operations for the inside of the reactor by introducing a swimming type operation robot into the reactor container. The swimming-type operation robot comprises a robot main body having a propeller, a balancer operably disposed to the robot main body and an inspection and repairing unit attached detachable to the balancer. In the device of the present invention, since the inspection and preparing unit is attached detachably to the swimming robot, a robot which transports tools is formed as a standard product. As a result, the production cost can be reduced, and the reliability of products can be improved. Appropriate operations can be conducted by using best tools. (I.S.)

Partial Device Fingerprints

NARCIS (Netherlands)

Ciere, M.; Hernandez Ganan, C.; van Eeten, M.J.G.

2017-01-01

In computing, remote devices may be identified by means of device fingerprinting, which works by collecting a myriad of clientside attributes such as the device’s browser and operating system version, installed plugins, screen resolution, hardware artifacts, Wi-Fi settings, and anything else

Automatic exchange unit for control rod drive device

International Nuclear Information System (INIS)

Nasu, Seiji; Sasaki, Masayoshi.

1982-01-01

Purpose: To enable automatic reoperation and continuation without external power interruption remedy device at the time of recovering the interrupted power soruce during automatic positioning operation. Constitution: In case of an automatic exchange unit for a control rod drive device of the control type for setting the deviation between the positioning target position and the present position of the device to zero, the position data of the drive device of the positioning target value of the device is automatically read, and an interlock of operation inhibit is applied to a control system until the data reading is completed and automatic operation start or restart conditions are sequentially confirmed. After the confirmation, the interlock is released to start the automatic operation or reoperation. Accordingly, the automatic operation can be safely restarted and continued. (Yoshihara, H.)

EPICS GPIB device support

International Nuclear Information System (INIS)

Winans, J.

1993-01-01

A GPIB device support module is used to provide access to the operating parameters of a GPIB device. GPIB devices may be accessed via National Instruments 1014 cards or via Bitbus Universal Gateways. GPIB devices typically have many parameters, each of which may be thought of in terms of the standard types of database records available in EPICS. It is the job of the device support module designer to decide how the mapping of these parameters will be made to the available record types. Once this mapping is complete, the device support module may be written. The writing of the device support module consists primarily of the construction of a parameter table. This table is used to associate the database record types with the operating parameters of the GPIB instrument. Other aspects of module design include the handling of SRQ events and errors. SRQ events are made available to the device support module if so desired. The processing of an SRQ event is completely up to the designer of the module. They may be ignored, tied to event based record processing, or anything else the designer wishes. Error conditions may be handled in a similar fashion

In-situ inspection of grooves in reactor tube sheet using a remotely operated cast impression taking device

International Nuclear Information System (INIS)

Rajendran, S.; Ramakumar, M.S.

1996-01-01

Utmost importance is given to the in-service inspection of critical components of a reactor to ensure its reliable performance during the reactor operation. This paper describes a cast taking device using cold setting resin to take impression of the grooves being made in the tube sheet for sparger tube installation in pressurised heavy water reactor. (author)

Fuel inspection device

International Nuclear Information System (INIS)

Tsuji, Tadashi.

1990-01-01

The fuel inspection device of the present invention has a feature of obtaining an optimum illumination upon fuel rod interval inspection operation in a fuel pool. That is, an illumination main body used underwater is connected to a cable which is led out on a floor. A light control device is attached to the other end of the cable and an electric power cable is connected to the light control device. A light source (for example, incandescent lamp) is incorporated in the casing of the illumination main body, and a diffusion plate is disposed at the front to provide a plane light source. The light control device has a light control knob capable of remote-controlling the brightness of the light of the illumination main body. In the fuel inspection device thus constituted, halation is scarcely caused on the image screen upon inspection of fuels by a submerged type television camera to facilitate control upon inspection. Accordingly, efficiency of the fuel inspection can be improved to shorten the operation time. (I.S.)

Electric control of antiferromagnets

OpenAIRE

Fina, I.; Marti, X.

2016-01-01

In the past five years, most of the paradigmatic concepts employed in spintronics have been replicated substituting ferromagnets by antiferromagnets in critical parts of the devices. The numerous research efforts directed to manipulate and probe the magnetic moments in antiferromagnets have been gradually established a new and independent field known as antiferromagnetic spintronics. In this paper, we focus on the electrical control and detection of antiferromagnetic moments at a constant tem...

Synchronization and chaos in spin-transfer-torque nano-oscillators coupled via a high-speed operational amplifier

International Nuclear Information System (INIS)

Sanid, C; Murugesh, S

2014-01-01

We propose a system of two coupled spin-torque nano-oscillators (STNOs), one driver and another response, and demonstrate using numerical studies the synchronization of the response system to the frequency of the driver system. To this end we use a high-speed operational amplifier in the form of a voltage follower, which essentially isolates the drive system from the response system. We find the occurrence of 1 : 1 as well as 2 : 1 synchronization in the system, wherein the oscillators show limit cycle dynamics. An increase in power output is noticed when the two oscillators are locked in 1 : 1 synchronization. Moreover in the crossover region between these two synchronization dynamics we show the existence of chaotic dynamics in the slave system. The coupled dynamics under periodic forcing, using a small ac input current in addition to that of the dc part, is also studied. The slave oscillator is seen to retain its qualitative identity in the parameter space in spite of being fed in, at times, a chaotic signal. Such electrically coupled STNOs will be highly useful in fabricating commercial spin-valve oscillators with high power output, when integrated with other spintronic devices. (paper)

Spin injection, transport, and read/write operation in spin-based MOSFET

International Nuclear Information System (INIS)

Saito, Yoshiaki; Marukame, Takao; Inokuchi, Tomoaki; Ishikawa, Mizue; Sugiyama, Hideyuki; Tanamoto, Tetsufumi

2011-01-01

We proposed a novel spin-based MOSFET 'Spin-Transfer-torque-Switching MOSFET (STS-MOSFET)' that offers non-volatile memory and transistor functions with complementary metal-oxide-semiconductor (CMOS) compatibility, high endurance and fast write time using STS. The STS-MOSFETs with Heusler alloy (Co 2 Fe 1 Al 0.5 Si 0.5 ) were prepared and reconfigurability of a novel spintronics-based MOSFET, STS-MOSFET, was successfully realized for the transport properties owing to reduction of the contact resistance in ferromagnetic metal/thin insulator tunnel barrier/Si junctions. The device showed magnetocurrent (MC) and write characteristics with the endurance of over 10 5 cycles. It was also clarified that the read characteristic can be improved in terms of MC ratio, however, is deteriorated in terms of the mobility by choosing connection configurations of the source and the drain in the STS-MOSFETs.

SRV-automatic handling device

International Nuclear Information System (INIS)

Yamada, Koji

1987-01-01

Automatic handling device for the steam relief valves (SRV's) is developed in order to achieve a decrease in exposure of workers, increase in availability factor, improvement in reliability, improvement in safety of operation, and labor saving. A survey is made during a periodical inspection to examine the actual SVR handling operation. An SRV automatic handling device consists of four components: conveyor, armed conveyor, lifting machine, and control/monitoring system. The conveyor is so designed that the existing I-rail installed in the containment vessel can be used without any modification. This is employed for conveying an SRV along the rail. The armed conveyor, designed for a box rail, is used for an SRV installed away from the rail. By using the lifting machine, an SRV installed away from the I-rail is brought to a spot just below the rail so that the SRV can be transferred by the conveyor. The control/monitoring system consists of a control computer, operation panel, TV monitor and annunciator. The SRV handling device is operated by remote control from a control room. A trial equipment is constructed and performance/function testing is carried out using actual SRV's. As a result, is it shown that the SRV handling device requires only two operators to serve satisfactorily. The required time for removal and replacement of one SRV is about 10 minutes. (Nogami, K.)

Device for controlling gas recovery

International Nuclear Information System (INIS)

Ichioka, Atsushi.

1976-01-01

Purpose: To provide a controlling device for UF 6 gas recovery device, which can increase working efficiency and to discriminate normality and abnormality of the recovery device. Constitution: The gas recovery device comprises a plurality of traps, which are connected in series. The UF 6 gas is introduced into the first trap where adsorbing work is taken place to accumulate UF 6 gases, and the UF 6 gases partly flow into the succeeding trap. Even in this trap, when the adsorbing work begins, the succeeding trap is operated in series fashion. In this manner, two traps are continuously operated to recover the gases while performing the steps of adsorbing, waiting and regenerating in that order. The switching operation of the aforesaid steps is accomplished on the basis of concentration of the UF 6 detected between two traps, which are continuously driven. (Kamimura, M.)

Generalized non-Local Resistance Expression and its Application in F/N/F Spintronic Structure with Graphene Channel

Science.gov (United States)

Wei, Huazhou; Fu, Shiwei

We report our work on the spin transport properties in the F/N/F(ferromagnets/normal metal/ferromagnets) spintronic structure from a new theoretical perspective. A significant problem in the field is to explain the inferior measured order of magnitude for spin lifetime. Based on the known non-local resistance formula and the mechanism analysis of spin-flipping within the interfaces between F and N, we analytically derive a broadly applicable new non-local resistance expression and a generalized Hanle curve formula. After employing them in the F/N/F structure under different limits, especially in the case of graphene channel, we find that the fitting from experimental data would yield a longer spin lifetime, which approaches its theoretical predicted value in graphene. The authors acknowledge the financial support by China University of Petroleum-Beijing and the Key Laboratory of Optical Detection Technology for Oil and Gas in this institution.

Electrical detection of spin transport in Si two-dimensional electron gas systems

Science.gov (United States)

Chang, Li-Te; Fischer, Inga Anita; Tang, Jianshi; Wang, Chiu-Yen; Yu, Guoqiang; Fan, Yabin; Murata, Koichi; Nie, Tianxiao; Oehme, Michael; Schulze, Jörg; Wang, Kang L.

2016-09-01

Spin transport in a semiconductor-based two-dimensional electron gas (2DEG) system has been attractive in spintronics for more than ten years. The inherent advantages of high-mobility channel and enhanced spin-orbital interaction promise a long spin diffusion length and efficient spin manipulation, which are essential for the application of spintronics devices. However, the difficulty of making high-quality ferromagnetic (FM) contacts to the buried 2DEG channel in the heterostructure systems limits the potential developments in functional devices. In this paper, we experimentally demonstrate electrical detection of spin transport in a high-mobility 2DEG system using FM Mn-germanosilicide (Mn(Si0.7Ge0.3)x) end contacts, which is the first report of spin injection and detection in a 2DEG confined in a Si/SiGe modulation doped quantum well structure (MODQW). The extracted spin diffusion length and lifetime are l sf = 4.5 μm and {τ }{{s}}=16 {{ns}} at 1.9 K respectively. Our results provide a promising approach for spin injection into 2DEG system in the Si-based MODQW, which may lead to innovative spintronic applications such as spin-based transistor, logic, and memory devices.

Rapid Transition of the Hole Rashba Effect from Strong Field Dependence to Saturation in Semiconductor Nanowires

Science.gov (United States)

Luo, Jun-Wei; Li, Shu-Shen; Zunger, Alex

2017-09-01

The electric field manipulation of the Rashba spin-orbit coupling effects provides a route to electrically control spins, constituting the foundation of the field of semiconductor spintronics. In general, the strength of the Rashba effects depends linearly on the applied electric field and is significant only for heavy-atom materials with large intrinsic spin-orbit interaction under high electric fields. Here, we illustrate in 1D semiconductor nanowires an anomalous field dependence of the hole (but not electron) Rashba effect (HRE). (i) At low fields, the strength of the HRE exhibits a steep increase with the field so that even low fields can be used for device switching. (ii) At higher fields, the HRE undergoes a rapid transition to saturation with a giant strength even for light-atom materials such as Si (exceeding 100 meV Å). (iii) The nanowire-size dependence of the saturation HRE is rather weak for light-atom Si, so size fluctuations would have a limited effect; this is a key requirement for scalability of Rashba-field-based spintronic devices. These three features offer Si nanowires as a promising platform for the realization of scalable complementary metal-oxide-semiconductor compatible spintronic devices.

On-chip synthesis of circularly polarized emission of light with integrated photonic circuits.

Science.gov (United States)

He, Li; Li, Mo

2014-05-01

The helicity of circularly polarized (CP) light plays an important role in the light-matter interaction in magnetic and quantum material systems. Exploiting CP light in integrated photonic circuits could lead to on-chip integration of novel optical helicity-dependent devices for applications ranging from spintronics to quantum optics. In this Letter, we demonstrate a silicon photonic circuit coupled with a 2D grating emitter operating at a telecom wavelength to synthesize vertically emitting, CP light from a quasi-TE waveguide mode. Handedness of the emitted circular polarized light can be thermally controlled with an integrated microheater. The compact device footprint enables a small beam diameter, which is desirable for large-scale integration.

Incore instrument device

International Nuclear Information System (INIS)

Sakima, Naoki

1996-01-01

An incore instrument device has an integrally disposed touch panel having a function of displaying an operation indication method such as for setting of conditions for incore measurement and information processing and results of the incore measurement and a function capable of conducting operation indication such as for setting conditions and information processing for incore measurement relative to a control section upon touching an information position on a displayed information. In addition, an information processing section comprising a man-machine function program formed so as to recognize the content of the operation indication for the incore measurement by touching and let the control section to conduct it is disposed to the outside by way of a communication interface. In addition, a programming device is disposed for forming and rewriting the program of the man-machine function relative to the information processing section. Then, when various indication operations are conducted upon performing incore measurement, a view point can be concentrated to one predetermined point thereby enabling to improve the operationability without danger. In addition, the programming of the man-machine function does not apply unnecessary load to the control section in the incore instrumentation device. (N.H.)

Inspection device in liquid

International Nuclear Information System (INIS)

Nagaoka, Etsuo.

1996-01-01

The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)

Teaching Advanced Operation of an iPod-Based Speech-Generating Device to Two Students with Autism Spectrum Disorders

Science.gov (United States)

Achmadi, Donna; Kagohara, Debora M.; van der Meer, Larah; O'Reilly, Mark F.; Lancioni, Giulio E.; Sutherland, Dean; Lang, Russell; Marschik, Peter B.; Green, Vanessa A.; Sigafoos, Jeff

2012-01-01

We evaluated a program for teaching two adolescents with autism spectrum disorders (ASD) to perform more advanced operations on an iPod-based speech-generating device (SGD). The effects of the teaching program were evaluated in a multiprobe multiple baseline across participants design that included two intervention phases. The first intervention…

A graphene spin diode based on Rashba SOI

International Nuclear Information System (INIS)

Mohammadpour, Hakimeh

2015-01-01

In this paper a graphene-based two-terminal electronic device is modeled for application in spintronics. It is based on a gapped armchair graphene nanoribbon (GNR). The electron transport is considered through a scattering or channel region which is sandwiched between two lateral semi-infinite ferromagnetic leads. The two ferromagnetic leads, being half-metallic, are supposed to be in either parallel or anti-parallel magnetization. Meanwhile, the central channel region is a normal layer under the influence of the Rashba SOI, induced e.g., by the substrate. The device operation is based on modulating the (spin-) current by tuning the strength of the RSOI. The resultant current, being spin-polarized, is controlled by the RSOI in mutual interplay with the channel length. Inverting alternating bias voltage to a fully rectified spin-current is the main achievement of this paper. - Highlights: • Graphene-based electronic device is modeled with ferromagnetic leads. • The device operation is based on modulating the (spin-) current by Rashba SOI. • Inverting alternating bias voltage to rectified spin-current is the main achievement

Studies on capillary tube expansion device used in J-T refrigerators operating with nitrogen-hydrocarbon mixtures

Science.gov (United States)

Harish Kruthiventi, S. S.; Venkatarathnam, G.

2017-10-01

Capillary tube expansion devices are used extensively in small closed cycle J-T refrigerators operating with refrigerant mixtures due to its low cost and the absence of any moving parts. It is possible for J-T refrigerators operating with mixtures that the velocity of refrigerant mixture at capillary tube outlet reaches a value where it equals the speed of sound at certain conditions. The variation of the speed of sound of nitrogen-hydrocarbon mixtures used in J-T refrigerators has been studied in two phase (vapour-liquid) and three-phase (Vapour-liquid-liquid) region as a function of temperature and pressure in this work. Also the conditions under which choking occurs in practical J-T refrigerators is investigated.

Integrated control rod monitoring device

International Nuclear Information System (INIS)

Saito, Katsuhiro

1997-01-01

The present invention provides a device in which an entire control rod driving time measuring device and a control rod position support device in a reactor building and a central control chamber are integrated systematically to save hardwares such as a signal input/output device and signal cables between boards. Namely, (1) functions of the entire control rod driving time measuring device for monitoring control rods which control the reactor power and a control rod position indication device are integrated into one identical system. Then, the entire devices can be made compact by the integration of the functions. (2) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated in a central operation board and a board in the site. Then, the place for the installation of them can be used in common in any of the cases. (3) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated to one identical system to save hardware to be used. Then, signal input/output devices and drift branching panel boards in the site and the central operation board can be saved, and cables for connecting both of the boards is no more necessary. (I.S.)

Repair and managing device in nuclear power plants

International Nuclear Information System (INIS)

Shinzawa, Katsuo.

1982-01-01

Purpose: To moderate the operator's labour by automatically carrying out the managing works for the repair of nuclear power plants. Constitution: Information concerning the content of the repair works inputted from an input device is arranged and analyzed in a calculation device and judged if it is the content for a format work or not. The calculation device has a function of extracting the information regarding the format work content from the memory device and comparing the plant information from the reading device before the repair work and after the recovering work. A printer connected to the output end of the calculation device issues an information regarding the format work content extracted from the memory device, that is, written work procedures and operation inhibition TAG. The content, period, person in charge, purpose, allowed items and the likes for the works are printed on the operation inhibition TAG. After the operation for the equipments, one half of them is charged to the equipment and the other half of them is charged to the reading device and the plant information is sent to the memory device. (Kawakami, Y.)

After-heat removing device

International Nuclear Information System (INIS)

Iwashige, Kengo; Otsuka, Masaya; Yokoyama, Iwao; Yamakawa, Masanori.

1990-01-01

The present invention concerns an after-heat removing device for first reactors. A heat accumulation portion provided in a cooling channel of an after-heat removing device is disposed before a coil-like heat conduction pipe for cooling of the after-heat removing device. During normal reactor operation, the temperature in the heat accumulation portion is near the temperature of the high temperature plenum due to heat conduction and heat transfer from the high temperature plenum. When the reactor is shutdown and the after-heat removing device is started, coolants cooled in the air cooler start circulation. The coolants arriving at the heat accumulation portion deprive heat from the heat accumulation portion and, ion turn, increase their temperature and then reach the cooling coil. Subsequently, the heat calorie possessed in the heat accumulation portion is reduced and the after-heat removing device is started for the operation at a full power. This can reduce the thermal shocks applied to the cooling coil or structures in a reactor vessel upon starting the after-heat removing device. (I.N.)

Towards Flexibility Detection in Device-Level Energy Consumption

DEFF Research Database (Denmark)

Neupane, Bijay; Pedersen, Torben Bach; Thiesson, Bo

2014-01-01

The increasing drive towards green energy has boosted the installation of Renewable Energy Sources (RES). Increasing the share of RES in the power grid requires demand management by flexibility in the consumption. In this paper, we perform a state-of-the-art analysis on the flexibility and operat......The increasing drive towards green energy has boosted the installation of Renewable Energy Sources (RES). Increasing the share of RES in the power grid requires demand management by flexibility in the consumption. In this paper, we perform a state-of-the-art analysis on the flexibility...... and operation patterns of the devices in a set of real households. We propose a number of specific pre-processing steps such as operation stage segmentation, and aberrant operation duration removal to clean device level data. Further, we demonstrate various device operation properties such as hourly and daily...... regularities and patterns and the correlation between operating different devices. Subsequently, we show the existence of detectable time and energy flexibility in device operations. Finally, we provide various results providing a foundation for load- and flexibility-detection and -prediction at the device...

BiFeO3 epitaxial thin films and devices: past, present and future

Science.gov (United States)

Sando, D.; Barthélémy, A.; Bibes, M.

2014-11-01

The celebrated renaissance of the multiferroics family over the past ten years has also been that of its most paradigmatic member, bismuth ferrite (BiFeO3). Known since the 1960s to be a high temperature antiferromagnet and since the 1970s to be ferroelectric, BiFeO3 only had its bulk ferroic properties clarified in the mid-2000s. It is however the fabrication of BiFeO3 thin films and their integration into epitaxial oxide heterostructures that have fully revealed its extraordinarily broad palette of functionalities. Here we review the first decade of research on BiFeO3 films, restricting ourselves to epitaxial structures. We discuss how thickness and epitaxial strain influence not only the unit cell parameters, but also the crystal structure, illustrated for instance by the discovery of the so-called T-like phase of BiFeO3. We then present its ferroelectric and piezoelectric properties and their evolution near morphotropic phase boundaries. Magnetic properties and their modification by thickness and strain effects, as well as optical parameters, are covered. Finally, we highlight various types of devices based on BiFeO3 in electronics, spintronics, and optics, and provide perspectives for the development of further multifunctional devices for information technology and energy harvesting.

Designing Security-Hardened Microkernels For Field Devices

Science.gov (United States)

Hieb, Jeffrey; Graham, James

Distributed control systems (DCSs) play an essential role in the operation of critical infrastructures. Perimeter field devices are important DCS components that measure physical process parameters and perform control actions. Modern field devices are vulnerable to cyber attacks due to their increased adoption of commodity technologies and that fact that control networks are no longer isolated. This paper describes an approach for creating security-hardened field devices using operating system microkernels that isolate vital field device operations from untrusted network-accessible applications. The approach, which is influenced by the MILS and Nizza architectures, is implemented in a prototype field device. Whereas, previous microkernel-based implementations have been plagued by poor inter-process communication (IPC) performance, the prototype exhibits an average IPC overhead for protected device calls of 64.59 μs. The overall performance of field devices is influenced by several factors; nevertheless, the observed IPC overhead is low enough to encourage the continued development of the prototype.

The design, operation and application of a low-cost electronic device for the determination of ion-intensity ratios

International Nuclear Information System (INIS)

Lawson, A.M.; Bulmer, R.J.; Lowe, A.E.; Pickup, J.F.

1977-01-01

A low-cost electronic device to monitor two ions and provide the ratio of their intensities is described. The device operates in two modes, repetitive and accumulative. In the repetitive mode consecutive channels are integrated and their ratios displayed and printed, whereas in the accumulative mode, integrals of ion intensities are summed for a period before ratios are given. The unit has been designed principally for application in quantitative experiments using stable-isotope dilution with mass spectrometry. The precision of the ratios generated are demonstrated using hexachlorobutadiene mass ions and a calibration series of mixtures of phosphate and 18 O-labelled phosphate as internal standard

Device for multi-dimensional γ-γ-coincidence study

International Nuclear Information System (INIS)

Gruzinova, T.M.; Erokhina, K.I.; Kutuzov, V.I.; Lemberg, I.Kh.; Petrov, S.A.; Revenko, V.S.; Senin, A.T.; Chugunov, I.N.; Shishlinov, V.M.

1977-01-01

A device for studying multi-dimensional γ-γ coincidences is described which operates on-line with the BESM-4 computer. The device comprises Ge(Li) detectors, analog-to-digital converters, shaper discriminators and fast amplifiers. To control the device operation as a whole and to elaborate necessary commands, an information distributor has been developed. The following specific features of the device operation are noted: the device may operate both in the regime of recording spectra of direct γ radiation in the block memory of multi-channel analyzer, and in the regime of data transfer to the computer memory; the device performs registration of coincidences; it transfers information to the computer which has a channel of direct access to the memory. The procedure of data processing is considered, the data being recorded on a magnetic tape. Partial spectra obtained are in a good agreement with data obtained elsewhere

Class 1 devices case studies in medical devices design

CERN Document Server

Ogrodnik, Peter J

2014-01-01

The Case Studies in Medical Devices Design series consists of practical, applied case studies relating to medical device design in industry. These titles complement Ogrodnik's Medical Device Design and will assist engineers with applying the theory in practice. The case studies presented directly relate to Class I, Class IIa, Class IIb and Class III medical devices. Designers and companies who wish to extend their knowledge in a specific discipline related to their respective class of operation will find any or all of these titles a great addition to their library. Class 1 Devices is a companion text to Medical Devices Design: Innovation from Concept to Market. The intention of this book, and its sister books in the series, is to support the concepts presented in Medical Devices Design through case studies. In the context of this book the case studies consider Class I (EU) and 510(k) exempt (FDA) . This book covers classifications, the conceptual and embodiment phase, plus design from idea to PDS. These title...

A High Power Boost Converter for PV Systems Operating up to 300 kHz using SiC Devices

DEFF Research Database (Denmark)

Anthon, Alexander; Zhang, Zhe; Andersen, Michael A. E.

2014-01-01

In this paper, a 3kW boost converter for PV applications using SiC devices is introduced. Main focus is to operate the converter over a wide range of switching frequency and to analyze the main loss distributors as well as the efficiency. The switching element is a recently introduced normally...... be operated at full power for a switching frequency of 100 kHz using natural cooling. At 200 kHz the boost converter is capable of operating at full power when forced air cooling is applied having a JFET case temperature of less than 90 C. The case temperature of the JFET increases up to 110 C at a switching...

[Prevention of medical device-related adverse events in hospitals: Specifying the recommendations of the German Coalition for Patient Safety (APS) for users and operators of anaesthesia equipment].

Science.gov (United States)

Bohnet-Joschko, Sabine; Zippel, Claus; Siebert, Hartmut

2015-01-01

The use and organisation of medical technology has an important role to play for patient and user safety in anaesthesia. Specification of the recommendations of the German Coalition for Patient Safety (APS) for users and operators of anaesthesia equipment, explore opportunities and challenges for the safe use and organisation of anaesthesia devices. We conducted a literature search in Medline/PubMed for studies dealing with the APS recommendations for the prevention of medical device-related risks in the context of anaesthesia. In addition, we performed an internet search for reports and recommendations focusing on the use and organisation of medical devices in anaesthesia. Identified studies were grouped and assigned to the recommendations. The division into users and operators was maintained. Instruction and training in anaesthesia machines is sometimes of minor importance. Failure to perform functional testing seems to be a common cause of critical incidents in anaesthesia. There is a potential for reporting to the federal authority. Starting points for the safe operation of anaesthetic devices can be identified, in particular, at the interface of staff, organisation, and (anaesthesia) technology. The APS recommendations provide valuable information on promoting the safe use of medical devices and organisation in anaesthesia. The focus will be on risks relating to the application as well as on principles and materials for the safe operation of anaesthesia equipment. Copyright © 2015. Published by Elsevier GmbH.

Using of explosive technologies for development of a compact current-limiting device for operation on 110 kV class systems

Science.gov (United States)

Shurupov, A. V.; Shurupov, M. A.; Kozlov, A. A.; Kotov, A. V.

2016-11-01

This paper considers the possibility of creating on new physical principles a highspeed current-limiting device (CLD) for the networks with voltage of 110 kV, namely, on the basis of the explosive switching elements. The device is designed to limit the steady short-circuit current to acceptable values for the time does not exceed 3 ms at electric power facilities. The paper presents an analysis of the electrical circuit of CLD. The main features of the scheme are: a new high-speed switching element with high regenerating voltage; fusible switching element that enables to limit the overvoltage after sudden breakage of network of the explosive switch; non-inductive resistor with a high heat capacity and a special reactor with operating time less than 1 s. We analyzed the work of the CLD with help of special software PSPICE, which is based on the equivalent circuit of single-phase short circuit to ground in 110 kV network. Analysis of the equivalent circuit operation CLD shows its efficiency and determines the CLD as a perspective direction of the current-limiting devices of new generation.

Using of explosive technologies for development of a compact current-limiting device for operation on 110 kV class systems

International Nuclear Information System (INIS)

Shurupov, A V; Shurupov, M A; Kozlov, A A; Kotov, A V

2016-01-01

This paper considers the possibility of creating on new physical principles a highspeed current-limiting device (CLD) for the networks with voltage of 110 kV, namely, on the basis of the explosive switching elements. The device is designed to limit the steady short-circuit current to acceptable values for the time does not exceed 3 ms at electric power facilities. The paper presents an analysis of the electrical circuit of CLD. The main features of the scheme are: a new high-speed switching element with high regenerating voltage; fusible switching element that enables to limit the overvoltage after sudden breakage of network of the explosive switch; non-inductive resistor with a high heat capacity and a special reactor with operating time less than 1 s. We analyzed the work of the CLD with help of special software PSPICE, which is based on the equivalent circuit of single-phase short circuit to ground in 110 kV network. Analysis of the equivalent circuit operation CLD shows its efficiency and determines the CLD as a perspective direction of the current-limiting devices of new generation. (paper)

An Overview of Biofield Devices

Science.gov (United States)

Muehsam, David; Chevalier, Gaétan; Barsotti, Tiffany

2015-01-01

Advances in biophysics, biology, functional genomics, neuroscience, psychology, psychoneuroimmunology, and other fields suggest the existence of a subtle system of “biofield” interactions that organize biological processes from the subatomic, atomic, molecular, cellular, and organismic to the interpersonal and cosmic levels. Biofield interactions may bring about regulation of biochemical, cellular, and neurological processes through means related to electromagnetism, quantum fields, and perhaps other means of modulating biological activity and information flow. The biofield paradigm, in contrast to a reductionist, chemistry-centered viewpoint, emphasizes the informational content of biological processes; biofield interactions are thought to operate in part via low-energy or “subtle” processes such as weak, nonthermal electromagnetic fields (EMFs) or processes potentially related to consciousness and nonlocality. Biofield interactions may also operate through or be reflected in more well-understood informational processes found in electroencephalographic (EEG) and electrocardiographic (ECG) data. Recent advances have led to the development of a wide variety of therapeutic and diagnostic biofield devices, defined as physical instruments best understood from the viewpoint of a biofield paradigm. Here, we provide a broad overview of biofield devices, with emphasis on those devices for which solid, peer-reviewed evidence exists. A subset of these devices, such as those based upon EEG- and ECG-based heart rate variability, function via mechanisms that are well understood and are widely employed in clinical settings. Other device modalities, such a gas discharge visualization and biophoton emission, appear to operate through incompletely understood mechanisms and have unclear clinical significance. Device modes of operation include EMF-light, EMF-heat, EMF-nonthermal, electrical current, vibration and sound, physical and mechanical, intentionality and nonlocality

Neutronic design of pulse operation simulating device for in-pile functional test of fusion blanket by MCNP

Energy Technology Data Exchange (ETDEWEB)

Nagao, Yoshiharu; Nakamichi, Masaru; Kawamura, Hiroshi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan)

2000-03-01

The pulse operation of a fusion reactor can be simulated in a fission reactor by controlling the neutron flux entering a test section by using a rotating 'hollow cylinder with window' made of hafnium. The rotating cylinder is installed between the test section and the fixed outer neutron absorber cylinder and is also made of hafnium with an opening in the direction to the core center. For gathering engineering data for the tritium breeding blanket such as characteristics of temperature change, tritium release and recovery, etc., it is desirable that the ratio of minimum to maximum thermal neutron fluxes is greater than 1:10. Design calculations were performed for the test assembly which considered local neutronic effects and the mechanical constraints of the device. From the results of these calculations, the ratio of minimum to maximum thermal neutron flux under irradiation would be about 1:10 using a pulse operation simulating device which has a thickness of 6.5 mm and a 150deg window angle for the rotating hollow cylinder and 5.0 mm in thickness of fixed neutron absorber. (author)

Split ring containment attachment device

International Nuclear Information System (INIS)

Sammel, A.G.

1996-01-01

A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

21 CFR 872.4630 - Dental operating light.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

Coating thickness measuring device

International Nuclear Information System (INIS)

Joffe, B.B.; Sawyer, B.E.; Spongr, J.J.

1984-01-01

A device especially adapted for measuring the thickness of coatings on small, complexly-shaped parts, such as, for example, electronic connectors, electronic contacts, or the like. The device includes a source of beta radiation and a radiation detector whereby backscatter of the radiation from the coated part can be detected and the thickness of the coating ascertained. The radiation source and detector are positioned in overlying relationship to the coated part and a microscope is provided to accurately position the device with respect to the part. Means are provided to control the rate of descent of the radiation source and radiation detector from its suspended position to its operating position and the resulting impact it makes with the coated part to thereby promote uniformity of readings from operator to operator, and also to avoid excessive impact with the part, thereby improving accuracy of measurement and eliminating damage to the parts

Articulating feedstock delivery device

Science.gov (United States)

Jordan, Kevin

2013-11-05

A fully articulable feedstock delivery device that is designed to operate at pressure and temperature extremes. The device incorporates an articulating ball assembly which allows for more accurate delivery of the feedstock to a target location. The device is suitable for a variety of applications including, but not limited to, delivery of feedstock to a high-pressure reaction chamber or process zone.

Smart devices are different

DEFF Research Database (Denmark)

Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav

2015-01-01

research results. This is due to variations in training and test device hardware and their operating system characteristics among others. In this paper, we systematically investigate sensor-, device- and workload-specific heterogeneities using 36 smartphones and smartwatches, consisting of 13 different...... device models from four manufacturers. Furthermore, we conduct experiments with nine users and investigate popular feature representation and classification techniques in HAR research. Our results indicate that on-device sensor and sensor handling heterogeneities impair HAR performances significantly...

Extended device profiles and testing procedures for the approval process of integrated medical devices using the IEEE 11073 communication standard.

Science.gov (United States)

Janß, Armin; Thorn, Johannes; Schmitz, Malte; Mildner, Alexander; Dell'Anna-Pudlik, Jasmin; Leucker, Martin; Radermacher, Klaus

2018-02-23

Nowadays, only closed and proprietary integrated operating room systems (IORS) from big manufacturers are available on the market. Hence, the interconnection of components from third-party vendors is only possible with increased time and costs. In the context of the German Federal Ministry of Education and Research (BMBF)-funded project OR.NET (2012-2016), the open integration of medical devices from different manufacturers was addressed. An integrated operating theater based on the open communication standard IEEE 11073 shall give clinical operators the opportunity to choose medical devices independently of the manufacturer. This approach would be advantageous especially for hospital operators and small- and medium-sized enterprises (SME) of medical devices. Actual standards and concepts regarding technical feasibility and the approval process do not cope with the requirements for a modular integration of medical devices in the operating room (OR), based on an open communication standard. Therefore, innovative approval strategies and corresponding certification and test procedures, which cover actual legal and normative standards, have to be developed in order to support the future risk management and the usability engineering process of open integrated medical devices in the OR. The use of standardized device and service profiles and a three-step testing procedure, including conformity, interoperability and integration tests are described in this paper and shall support the manufacturers to integrate their medical devices without disclosing the medical devices' risk analysis and related confidential expertise or proprietary information.

Control rod position control device

International Nuclear Information System (INIS)

Ubukata, Shinji.

1997-01-01

The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

Resistive switching mechanism of ZnO/ZrO2-stacked resistive random access memory device annealed at 300 °C by sol-gel method with forming-free operation

Science.gov (United States)

Jian, Wen-Yi; You, Hsin-Chiang; Wu, Cheng-Yen

2018-01-01

In this work, we used a sol-gel process to fabricate a ZnO-ZrO2-stacked resistive switching random access memory (ReRAM) device and investigated its switching mechanism. The Gibbs free energy in ZnO, which is higher than that in ZrO2, facilitates the oxidation and reduction reactions of filaments in the ZnO layer. The current-voltage (I-V) characteristics of the device revealed a forming-free operation because of nonlattice oxygen in the oxide layer. In addition, the device can operate under bipolar or unipolar conditions with a reset voltage of 0 to ±2 V, indicating that in this device, Joule heating dominates at reset and the electric field dominates in the set process. Furthermore, the characteristics reveal why the fabricated device exhibits a greater discrete distribution phenomenon for the set voltage than for the reset voltage. These results will enable the fabrication of future ReRAM devices with double-layer oxide structures with improved characteristics.

Safety lock for radiography exposure device

International Nuclear Information System (INIS)

Gaines, T.M.

1982-01-01

A safety lock for securing a radiation source in a radiography exposure device is disclosed. The safety lock prevents the inadvertent extension of the radiation source from the exposure device. The exposure devices are used extensively in industry for nondestructive testing of metal materials for defect. Unnecessary exposure of the radiographer or operator occurs not infrequently due to operator's error in believing that the radiation source is secured in the exposure device when, in fact, it is not. The present invention solves this problem of unnecessary exposure by releasingly trapping the radiation source in the shield of the radiography exposure device each time the source is retracted therein so that it is not inadvertently extended therefrom without the operator resetting the safety lock, thereby releasing the radiation source. Further, the safety lock includes an indicator which indicates when the source is trapped in the exposure device and also when it is untrapped. The safety lock is so designed that it does not prevent the return of the source to the trapped, shielded position in the exposure device. Further the safety lock includes a key means for locking the radiation source in the trapped position. The key means cannot be actuated until said radiation source is in said trapped position to further insure the safety lock cannot be inadvertently locked with the source untrapped and thus still extendable from the exposure device

Control system of fuel transporting device

International Nuclear Information System (INIS)

Yokota, Minoru.

1981-01-01

Purpose: To effectively avoid an obstacle in a fuel transporting device by reading the outputs of absolute position detectors mounted on movable trucks, controlling the movements of the trucks, and thereby smoothly and accurately positioning the fuel transporting device at predetermined position and providing a contact detector thereat. Method: The outputs from absolute position detectors which are mounted on a longitudinally movable truck and a laterally movable truck are input to an input/output control circuit. The input/output control circuit serves to compare, the position a fuel transporting device is to be moved to, with the present position on the basis of said input detection signal and a command signal from an operator console, to calculate the amount of movement to be driven, to produce an operation signal therefor to a control panel, and to drive and control the drive motors which are respectively mounted on the trucks for the fuel transfer device. On the other hand, in case that the transfer device comes into contact with an obstacle, the contact detector will immediately operate to produce a stop command through the control panel to the transporting device, and avoid a collision with the obstacle. (Yoshino, Y.)

Safety by design: effects of operating room floor marking on the position of surgical devices to promote clean air flow compliance and minimise infection risks

NARCIS (Netherlands)

de Korne, Dirk F.; van Wijngaarden, Jeroen D. H.; van Rooij, Jeroen; Wauben, Linda S. G. L.; Hiddema, U. Frans; Klazinga, Niek S.

2012-01-01

To evaluate the use of floor marking on the positioning of surgical devices within the clean air flow in an operating room (OR) to minimise infection risk. Laminar flow clean air systems are important in preventing infection in ORs but, for optimal results, surgical devices must be correctly

Role of Ni2+(d8) ions in electrical, optical and magnetic properties of CdS nanowires for optoelectronic and spintronic applications

Science.gov (United States)

Arshad Kamran, Muhammad

2018-06-01

For the first time, 1D Ni ion doped CdS nanowires (NWs) were synthesized via chemical vapour deposition (CVD). The synthesized Cd0.886Ni0.114S NWs were single crystalline. We have reported here the investigation of optical, electrical and magnetic properties of prepared NWs for optoelectronic and spintronic applications. Successful incorporation of Ni ions in an individual CdS NW has been confirmed through several characterization tools: significantly higher angle and phonon mode shift were observed in the XRD and Raman spectra. SEM-EDX and XPS analysis also confirmed the presence of Ni2+ ions. Room temperature photoluminescence (RT-PL) showed multiple peaks: two emission peaks in the visible region centered at 517.1 nm (green), 579.2 nm (orange), and a broad-band near infra-red (NIR) emission centered at 759.9 nm. The first peak showed 5 nm red shift upon Ni2+ doping, hinting at the formation of exciton magnetic polarons (EMPs), and broad NIR emission was observed in both chlorides and bromides, which was assigned to d‑d transition of Ni ions whose energy levels lying at 749.51 nm (13 342 cm–1) and 750.98 nm (13 316 cm–1) are very close to NIR emission. Orange emission not only remained at same peak position—its PL intensity was also significantly enhanced at 78 K; this was assigned to d‑d transition (3A2g → 1Eg) of Ni2+ ions. It was observed that 11.4% Ni2+ ion doping enhanced the conductivity of our sample around 20 times, and saturation magnetization (Ms) increased from 7.2 × 10‑5 Am2/Kg to 1.17 × 10‑4 Am2/Kg, which shows promise for optoelectronic and spintronic applications.

Testing device for control rod drives

International Nuclear Information System (INIS)

Hayakawa, Toshifumi.

1992-01-01

A testing device for control rod drives comprises a logic measuring means for measuring an output signal from a control rod drive logic generation circuit, a control means for judging the operation state of a control rod and a man machine interface means for outputting the result of the judgement. A driving instruction outputted from the control rod operation device is always monitored by the control means, and if the operation instruction is stopped, a testing signal is outputted to the control rod control device to simulate a control rod operation. In this case, the output signal of the control rod drive logic generation circuit is held in a control rod drive memory means and intaken into a logic analysis means for measurement and an abnormality is judged by the control means. The stopping of the control rod drive instruction is monitored and the operation abnormality of the control rod is judged, to mitigate the burden of an operator. Further, the operation of the control rod drive logic generation circuit can be confirmed even during a nuclear plant operation by holding the control rod drive instruction thereby enabling to improve maintenance efficiency. (N.H.)

Cooling device in thermonuclear device

International Nuclear Information System (INIS)

Honda, Tsutomu.

1988-01-01

Purpose: To prevent loss of cooling effect over the entire torus structure directly after accidental toubles in a cooling device of a thermonuclear device. Constitution: Coolant recycling means of a cooling device comprises two systems, which are alternately connected with in-flow pipeways and exit pipeways of adjacent modules. The modules are cooled by way of the in-flow pipeways and the exist pipeways connected to the respective modules by means of the coolant recycling means corresponding to the respective modules. So long as one of the coolant recycling means is kept operative, since every one other modules of the torus structure is still kept cooled, the heat generated from the module put therebetween, for which the coolant recycling is interrupted, is removed by means of heat conduction or radiation from the module for which the cooling is kept continued. No back-up emergency cooling system is required and it can provide high economic reliability. (Kamimura, M.)

Self-operation type power control device for nuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Kanbe, Mitsuru.

1993-07-23

The device of the present invention operates by sensing the temperature change of a reactor core in all of LMFBR type reactors irrespective of the scale of the reactor core power. That is, a region where liquid poison is filled is disposed at the upper portion and a region where sealed gases are filled is disposed at the lower portion of a pipe having both ends thereof being closed. When the pipe is inserted into the reactor core, the inner diameter of the pipe is determined smaller than a predetermined value so that the boundary between the liquid poison and the sealed gases in the pipe is maintained relative to an assumed maximum acceleration. The sealed gas region is disposed at the reactor core region. If the liquid poison is expanded by the elevation of the reactor core exit temperature, it is moved to the lower gas region, to control the reactor power. Since high reliability can be maintained over a long period of time by this method, it is suitable to FBR reactors disposed in such environments that maintenance can not easily be conducted, such as desserts, isolated islands and undeveloped countries. Further, it is also suitable to ultra small sized nuclear reactors disposed at environments that the direction and the magnitude of gravity are different from those on the ground. (I.S.).

Self-operation type power control device for nuclear reactor

International Nuclear Information System (INIS)

Kanbe, Mitsuru.

1993-01-01

The device of the present invention operates by sensing the temperature change of a reactor core in all of LMFBR type reactors irrespective of the scale of the reactor core power. That is, a region where liquid poison is filled is disposed at the upper portion and a region where sealed gases are filled is disposed at the lower portion of a pipe having both ends thereof being closed. When the pipe is inserted into the reactor core, the inner diameter of the pipe is determined smaller than a predetermined value so that the boundary between the liquid poison and the sealed gases in the pipe is maintained relative to an assumed maximum acceleration. The sealed gas region is disposed at the reactor core region. If the liquid poison is expanded by the elevation of the reactor core exit temperature, it is moved to the lower gas region, to control the reactor power. Since high reliability can be maintained over a long period of time by this method, it is suitable to FBR reactors disposed in such environments that maintenance can not easily be conducted, such as desserts, isolated islands and undeveloped countries. Further, it is also suitable to ultra small sized nuclear reactors disposed at environments that the direction and the magnitude of gravity are different from those on the ground. (I.S.)

Spin injection and transport in semiconductor and metal nanostructures

Science.gov (United States)

Zhu, Lei

In this thesis we investigate spin injection and transport in semiconductor and metal nanostructures. To overcome the limitation imposed by the low efficiency of spin injection and extraction and strict requirements for retention of spin polarization within the semiconductor, novel device structures with additional logic functionality and optimized device performance have been developed. Weak localization/antilocalization measurements and analysis are used to assess the influence of surface treatments on elastic, inelastic and spin-orbit scatterings during the electron transport within the two-dimensional electron layer at the InAs surface. Furthermore, we have used spin-valve and scanned probe microscopy measurements to investigate the influence of sulfur-based surface treatments and electrically insulating barrier layers on spin injection into, and spin transport within, the two-dimensional electron layer at the surface of p-type InAs. We also demonstrate and analyze a three-terminal, all-electrical spintronic switching device, combining charge current cancellation by appropriate device biasing and ballistic electron transport. The device yields a robust, electrically amplified spin-dependent current signal despite modest efficiency in electrical injection of spin-polarized electrons. Detailed analyses provide insight into the advantages of ballistic, as opposed to diffusive, transport in device operation, as well as scalability to smaller dimensions, and allow us to eliminate the possibility of phenomena unrelated to spin transport contributing to the observed device functionality. The influence of the device geometry on magnetoresistance of nanoscale spin-valve structures is also demonstrated and discussed. Shortcomings of the simplified one-dimensional spin diffusion model for spin valve are elucidated, with comparison of the thickness and the spin diffusion length in the nonmagnetic channel as the criterion for validity of the 1D model. Our work contributes

Charging device for an electrostatic accelerator

International Nuclear Information System (INIS)

Pivovar, L.I.; Khurgin, K.M.

1983-01-01

The invention relates to electrostatic accelerators operating in compressed gases and charged by a charge-carrying belt transport device with driving and driven shafts. The aim of the invention is the increase of service life of the device by decreasing deflection of the charge-carrying belt in high-voltage conductor operation at high voltages. Increase of survice life of the device is provided due to the fact that the belt as a whole is more stable and it runs true without slacking shielding rods

Evaluation of a training program for device operators in the Australian Government's Point of Care Testing in General Practice Trial: issues and implications for rural and remote practices.

Science.gov (United States)

Shephard, Mark D; Mazzachi, Beryl C; Watkinson, Les; Shephard, Anne K; Laurence, Caroline; Gialamas, Angela; Bubner, Tanya

2009-01-01

From September 2005 to February 2007 the Australian Government funded the Point of Care Testing (PoCT) in General Practice Trial, a multi-centre, cluster randomised controlled trial to determine the safety, clinical effectiveness, cost-effectiveness and satisfaction of PoCT in General Practice. In total, 53 practices (23 control and 30 intervention) based in urban, rural or remote locations across three states (South Australia [SA], New South Wales [NSW] and Victoria [VIC]) participated in the Trial. Control practices had pathology testing performed by their local laboratory, while intervention practices conducted pathology testing by PoCT. In total, 4968 patients (1958 control and 3010 intervention) participated in the Trial. The point-of-care (PoC) tests performed by intervention practices were: haemoglobin A1c (HbA1c) and urine albumin:creatinine ratio (ACR) on patients with diabetes, total cholesterol, triglyceride and high density lipoprotein (HDL) cholesterol on patients with hyperlipidaemia, and international normalised ratio (INR) on patients on anticoagulant therapy. Three PoCT devices measured these tests: the Siemens DCA 2000 (Siemens HealthCare Diagnostics, Melbourne, VIC, Australia) for HbA1c and urine ACR; Point of Care Diagnostics Cholestech LDX analyser (Point of Care Diagnostics; Sydney, NSW, Australia) for lipids; and the Roche CoaguChek S (Roche Diagnostics; Sydney, NSW, Australia) for INR. Point-of-care testing in the General Practice Trial was underpinned by a quality management framework which included an on-going training and competency program for PoCT device operators. This article describes the design, implementation and results of the training and competency program. An education and training resource package was developed for the Trial consisting of a training manual, a set of A3 laminated posters and a CD ROM. Five initial training workshops were held for intervention practices from each geographic region between August and October 2005

Microwave Plasma Based Single-Step Method for Generation of Carbon Nanostructures

Science.gov (United States)

2013-07-01

Técnico, Technical University of Lisbon, Portugal 2 Mechanical and Aerospace Engeneering , Naval Postgraduate School, Monterey, CA 93943, U.S.A...applications include electronic devices, transparent conductive films, mechanical devices, chemical sensors, spintronic devices. Moreover, it shows enormous...potential as a storage material for energy applications. Graphene of highest quality can be obtained by mechanically exfoliating highly oriented

Radiation emitting devices regulations

International Nuclear Information System (INIS)

1970-01-01

The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

Graphene: from functionalization to devices

Science.gov (United States)

Tejeda, Antonio; Soukiassian, Patrick G.

2014-03-01

The year 2014 marks the first decade of the rise of graphene. Graphene, a single atomic layer of carbon atoms in sp2 bonding configuration having a honeycomb structure, has now become a well-known and well-established material. Among some of its many outstanding fundamental properties, one can mention a very high carrier mobility, a very large spin diffusion length, unsurpassed mechanical properties as graphene is the strongest material ever measured and an exceptional thermal conductivity scaling more than one order of magnitude above that of copper. After the first years of the graphene rush, graphene growth is now well controlled using various methods like epitaxial growth on silicon carbide substrate, chemical vapour deposition (CVD) or plasma techniques on metal, insulator or semiconductor substrates. More applied research is now taking over the initial studies on graphene production. Indeed, graphene is a promising material for many advanced applications such as, but not limited to, electronic, spintronics, sensors, photonics, micro/nano-electromechanical (MEMS/NEMS) systems, super-capacitors or touch-screen technologies. In this context, this Special Issue of the Journal of Physics D: Applied Physics on graphene reviews some of the recent achievements, progress and prospects in this field. It includes a collection of seventeen invited articles covering the current status and future prospects of some selected topics of strong current interest. This Special Issue is organized in four sections. The first section is dedicated to graphene devices, and opens with an article by de Heer et al on an investigation of integrating graphene devices with silicon complementary metal-oxide-semiconductor (CMOS) technology. Then, a study by Svintsov et al proposes a lateral all-graphene tunnel field-effect transistor (FET) with a high on/off current switching ratio. Next, Tsukagoshi et al present how a band-gap opening occurs in a graphene bilayer by using a perpendicular

Development of digital device based work verification system for cooperation between main control room operators and field workers in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Min, E-mail: jewellee@kaeri.re.kr [Korea Atomic Energy Research Institute, 305-353, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Hyun Chul, E-mail: leehc@kaeri.re.kr [Korea Atomic Energy Research Institute, 305-353, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Ha, Jun Su, E-mail: junsu.ha@kustar.ac.ae [Department of Nuclear Engineering, Khalifa University of Science Technology and Research, Abu Dhabi P.O. Box 127788 (United Arab Emirates); Seong, Poong Hyun, E-mail: phseong@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2016-10-15

Highlights: • A digital device-based work verification and cooperation support system was developed. • Requirements were derived by interviewing field operators having experiences with mobile-based work support systems. • The usability of the proposed system was validated by conducting questionnaire surveys. • The proposed system will be useful if the manual or the set of guidelines is well constructed. - Abstract: Digital technologies have been applied in the nuclear field to check task results, monitor events and accidents, and transmit/receive data. The results of using digital devices have proven that these devices can provide high accuracy and convenience for workers, allowing them to obtain obvious positive effects by reducing their workloads. In this study, as one step forward, a digital device-based cooperation support system, the nuclear cooperation support and mobile documentation system (Nu-COSMOS), is proposed to support communication between main control room (MCR) operators and field workers by verifying field workers’ work results in nuclear power plants (NPPs). The proposed system consists of a mobile based information storage system to support field workers by providing various functions to make workers more trusted by MCR operators; also to improve the efficiency of meeting, and a large screen based information sharing system supports meetings by allowing both sides to share one medium. The usability of this system was estimated by interviewing field operators working in nuclear power plants and experts who have experience working as operators. A survey to estimate the usability of the suggested system and the suitability of the functions of the system for field working was conducted for 35 subjects who have experience in field works or with support system development-related research. The usability test was conducted using the system usability scale (SUS), which is widely used in industrial usability evaluation. Using questionnaires

Development of digital device based work verification system for cooperation between main control room operators and field workers in nuclear power plants

International Nuclear Information System (INIS)

Lee, Seung Min; Lee, Hyun Chul; Ha, Jun Su; Seong, Poong Hyun

2016-01-01

Highlights: • A digital device-based work verification and cooperation support system was developed. • Requirements were derived by interviewing field operators having experiences with mobile-based work support systems. • The usability of the proposed system was validated by conducting questionnaire surveys. • The proposed system will be useful if the manual or the set of guidelines is well constructed. - Abstract: Digital technologies have been applied in the nuclear field to check task results, monitor events and accidents, and transmit/receive data. The results of using digital devices have proven that these devices can provide high accuracy and convenience for workers, allowing them to obtain obvious positive effects by reducing their workloads. In this study, as one step forward, a digital device-based cooperation support system, the nuclear cooperation support and mobile documentation system (Nu-COSMOS), is proposed to support communication between main control room (MCR) operators and field workers by verifying field workers’ work results in nuclear power plants (NPPs). The proposed system consists of a mobile based information storage system to support field workers by providing various functions to make workers more trusted by MCR operators; also to improve the efficiency of meeting, and a large screen based information sharing system supports meetings by allowing both sides to share one medium. The usability of this system was estimated by interviewing field operators working in nuclear power plants and experts who have experience working as operators. A survey to estimate the usability of the suggested system and the suitability of the functions of the system for field working was conducted for 35 subjects who have experience in field works or with support system development-related research. The usability test was conducted using the system usability scale (SUS), which is widely used in industrial usability evaluation. Using questionnaires

A 3D CFD Modelling Study of a Diesel Oil Evaporation Device Operating in the Stabilized Cool Flame Regime

Directory of Open Access Journals (Sweden)

Dionysios I. Kolaitis

2010-12-01

Full Text Available Diesel fuel is used in a variety of technological applications due to its high energy density and ease of distribution and storage. Motivated by the need to use novel fuel utilization techniques, such as porous burners and fuel cells, which have to be fed with a gaseous fuel, a Diesel fuel evaporation device, operating in the “Stabilized Cool Flame” (SCF regime, is numerically investigated. In this device, a thermo-chemically stable low-temperature oxidative environment is developed, which produces a well-mixed, heated air-fuel vapour gaseous mixture that can be subsequently fed either to premixed combustion systems or fuel reformer devices for fuel cell applications. In this work, the ANSYS CFX 11.0 CFD code is used to simulate the three-dimensional, turbulent, two-phase, multi-component and reacting flow-field, developed in a SCF evaporation device. An innovative modelling approach, based on the fitting parameter concept, has been developed in order to simulate cool flame reactions. The model, based on physico-chemical reasoning coupled with information from available experimental data, is implemented in the CFD code and is validated by comparing numerical predictions to experimental data obtained from an atmospheric pressure, recirculating flow SCF device. Numerical predictions are compared with temperature measurements, achieving satisfactory levels of agreement. The developed numerical tool can effectively support the theoretical study of the physical and chemical phenomena emerging in practical devices of liquid fuel spray evaporation in a SCF environment, as well as the design optimisation process of such innovative devices.

[Design of SCM inoculation device].

Science.gov (United States)

Qian, Mingli; Xie, Haiyuan

2014-01-01

The first step of bacilli culture is inoculation bacteria on culture medium. Designing a device to increase efficiency of inoculation is significative. The new device is controlled by SCM. The stepper motor can drive the culture medium rotating, accelerating, decelerating, overturn and suspending. The device is high practicability and efficient, let inoculation easy for operator.

Spill-Detector-and-Shutoff Device

Science.gov (United States)

Jarvis, M. R.; Fulton, D. S.

1985-01-01

Overflow in liquid chromatography systems rapidly detected and stopped. Spill-detector-and-shutoff device incorporated into liquid-chromatography system. When liquid from output nozzle spills on liquid sensor, device automatically shuts off pump and releases solenoid to pinch off flow in tube. Device uses common type of alarm circuit reset manually before normal operation resumes.

Post-operative orbital imaging: a focus on implants and prosthetic devices

International Nuclear Information System (INIS)

Adams, Ashok; Mankad, Kshitij; Poitelea, Cornelia; Verity, David H.; Davagnanam, Indran

2014-01-01

Accurate interpretation of orbital imaging in the presence of either orbital implants requires a sound knowledge of both the surgical approach used and the imaging characteristics of the implanted devices themselves. In this article, the radiological appearance of the various devices used in ophthalmology, and their relationship to other orbital structures, is reviewed. In addition, the intended anatomical location, function of these devices, and clinical indications for their use are provided. (orig.)

47 CFR 2.801 - Radiofrequency device defined.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2... MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device defined. As used in this part, a radiofrequency device is any device which in its operation is capable of...

Secure-Network-Coding-Based File Sharing via Device-to-Device Communication

OpenAIRE

Wang, Lei; Wang, Qing

2017-01-01

In order to increase the efficiency and security of file sharing in the next-generation networks, this paper proposes a large scale file sharing scheme based on secure network coding via device-to-device (D2D) communication. In our scheme, when a user needs to share data with others in the same area, the source node and all the intermediate nodes need to perform secure network coding operation before forwarding the received data. This process continues until all the mobile devices in the netw...

α-sealed transfer device and portable plastic film sealers

International Nuclear Information System (INIS)

Fu Zhujun; Shan Ruixia

1990-04-01

An α transfer device which can be operated remotely is presented. The device is able to perform sealed transfer of radioactive articles from a hot cell or shielded glove box to the outside and non-radioactive articles from the outside to a hot cell or shielded glove box by using bag sealing technology. The structure of the transfer device is simple. Its operation is safe and reliable. The sealing performance of the device is very good (for alpha). The use of this transfer device will greatly reduce α contamination of the building and creates a favourable condition for operating radioactive materials in an undivided area. The portable heat sealing device is also a necessary tool in bag sealing technology and α-sealed transfer. Two types of portable plastic film sealers have been developed. Their structure is simple. The operation of the portable plastic film sealers is easy. Their performance is also excellent. Both the α-sealed transfer device and portable plastic film sealers are very useful to the reprocessing plant of nuclear fuel

Scheme for Quantum Computing Immune to Decoherence

Science.gov (United States)

Williams, Colin; Vatan, Farrokh

2008-01-01

A constructive scheme has been devised to enable mapping of any quantum computation into a spintronic circuit in which the computation is encoded in a basis that is, in principle, immune to quantum decoherence. The scheme is implemented by an algorithm that utilizes multiple physical spins to encode each logical bit in such a way that collective errors affecting all the physical spins do not disturb the logical bit. The scheme is expected to be of use to experimenters working on spintronic implementations of quantum logic. Spintronic computing devices use quantum-mechanical spins (typically, electron spins) to encode logical bits. Bits thus encoded (denoted qubits) are potentially susceptible to errors caused by noise and decoherence. The traditional model of quantum computation is based partly on the assumption that each qubit is implemented by use of a single two-state quantum system, such as an electron or other spin-1.2 particle. It can be surprisingly difficult to achieve certain gate operations . most notably, those of arbitrary 1-qubit gates . in spintronic hardware according to this model. However, ironically, certain 2-qubit interactions (in particular, spin-spin exchange interactions) can be achieved relatively easily in spintronic hardware. Therefore, it would be fortunate if it were possible to implement any 1-qubit gate by use of a spin-spin exchange interaction. While such a direct representation is not possible, it is possible to achieve an arbitrary 1-qubit gate indirectly by means of a sequence of four spin-spin exchange interactions, which could be implemented by use of four exchange gates. Accordingly, the present scheme provides for mapping any 1-qubit gate in the logical basis into an equivalent sequence of at most four spin-spin exchange interactions in the physical (encoded) basis. The complexity of the mathematical derivation of the scheme from basic quantum principles precludes a description within this article; it must suffice to report

Pressurized waterproof case for electronic device

KAUST Repository

Berumen, Michael L.

2013-01-31

The pressurized waterproof case for an electronic device is particularly adapted for the waterproof containment and operation of a touch-screen computer or the like therein at some appreciable water depth. The case may be formed as an enclosure having an open top panel or face covered by a flexible, transparent membrane or the like for the operation of the touch-screen device within the case. A pressurizing system is provided for the case to pressurize the case and the electronic device therein to slightly greater than ambient in order to prevent the external water pressure from bearing against the transparent membrane and pressing it against the touch screen, thereby precluding operation of the touch screen device within the case. The pressurizing system may be a small gas cartridge (e.g., CO2), or may be provided from an external source, such as the diver\\'s breathing air. A pressure relief valve is also provided.

FACTS device control strategy using PMU

Directory of Open Access Journals (Sweden)

Mohd Tauseef Khan

2016-09-01

Full Text Available The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

Fundamental investigation of high temperature operation of field effect transistor devices

Science.gov (United States)

Chern, Jehn-Huar

, JFET, pseudomorphic-HEMT, and modulation doped FET (MODFET) devices for high-temperature applications were investigated and addressed in terms of device performance such as transconductance, leakage current density, and current gain. Wide gap materials such as GaN have low carrier generation rate at high temperatures and, hence, high operation temperature capabilities and potential.

Fast, Capacious Disk Memory Device

Science.gov (United States)

Muller, Ronald M.

1990-01-01

Device for recording digital data on, and playing back data from, memory disks has high recording or playback rate and utilizes available recording area more fully. Two disks, each with own reading/writing head, used to record data at same time. Head on disk A operates on one of tracks numbered from outside in; head on disk B operates on track of same number in sequence from inside out. Underlying concept of device applicable to magnetic or optical disks.

Advanced High Voltage Power Device Concepts

CERN Document Server

Baliga, B Jayant

2012-01-01

Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

Rational Design of Two-Dimensional Metallic and Semiconducting Spintronic Materials Based on Ordered Double-Transition-Metal MXenes

KAUST Repository

Dong, Liang

2016-12-30

Two-dimensional (2D) materials that display robust ferromagnetism have been pursued intensively for nanoscale spintronic applications, but suitable candidates have not been identified. Here we present theoretical predictions on the design of ordered double-transition-metal MXene structures to achieve such a goal. On the basis of the analysis of electron filling in transition-metal cations and first-principles simulations, we demonstrate robust ferromagnetism in Ti2MnC2Tx monolayers regardless of the surface terminations (T = O, OH, and F), as well as in Hf2MnC2O2 and Hf2VC2O2 monolayers. The high magnetic moments (3–4 μB/unit cell) and high Curie temperatures (495–1133 K) of these MXenes are superior to those of existing 2D ferromagnetic materials. Furthermore, semimetal-to-semiconductor and ferromagnetic-to-antiferromagnetic phase transitions are predicted to occur in these materials in the presence of small or moderate tensile in-plane strains (0–3%), which can be externally applied mechanically or internally induced by the choice of transition metals.

Reactor control device

International Nuclear Information System (INIS)

Fukami, Haruo; Morimoto, Yoshinori.

1981-01-01

Purpose: To operate a reactor always with safety operation while eliminating the danger of tripping. Constitution: In a reactor control device adapted to detect the process variants of a reactor, control a control rod drive controlling system based on the detected signal to thereby control the driving the control rods, control the reactor power and control the electric power generated from an electric generator by the output from the reactor, detection means is provided for the detection of the electric power from said electric generator, and a compensation device is provided for outputting control rod driving compensation signals to the control rod driving controlling system in accordance with the amount of variation in the detected value. (Seki, T.)

Diagnostic for two-mode variable valve activation device

Science.gov (United States)

Fedewa, Andrew M

2014-01-07

A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

Pressurized waterproof case electronic device

KAUST Repository

Berumen, Michael L.

2013-01-01

A pressurized waterproof case for an electronic device is particularly adapted for fluid-tight containment and operation of a touch-screen electronic device or the like therein at some appreciable water depth. In one example, the case may be formed

SPICE modelling of magnetic tunnel junctions written by spin-transfer torque

Energy Technology Data Exchange (ETDEWEB)

Guo, W; Prenat, G; De Mestier, N; Baraduc, C; Dieny, B [SPINTEC, UMR(8191), INAC, CEA/CNRS/UJF, 17 Av. des Martyrs, 38054 Grenoble Cedex 9 (France); Javerliac, V; El Baraji, M, E-mail: guillaume.prenat@cea.f [CROCUS Technology, 5 Place Robert Schuman, 38025 Grenoble (France)

2010-06-02

Spintronics aims at extending the possibility of conventional electronics by using not only the charge of the electron but also its spin. The resulting spintronic devices, combining the front-end complementary metal oxide semiconductor technology of electronics with a magnetic back-end technology, employ magnetic tunnel junctions (MTJs) as core elements. With the intent of simulating a circuit without fabricating it first, a reliable MTJ electrical model which is applicable to the standard SPICE (Simulation Program with Integrated Circuit Emphasis) simulator is required. Since such a model was lacking so far, we present a MTJ SPICE model whose magnetic state is written by using the spin-transfer torque effect. This model has been developed in the C language and validated on the Cadence Virtuoso Platform with a Spectre simulator. Its operation is similar to that of the standard BSIM (Berkeley Short-channel IGFET Model) SPICE model of the MOS transistor and fully compatible with the SPICE electrical simulator. The simulation results obtained using this model have been found in good accord with those theoretical macrospin calculations and results.

Nanolayers with advanced properties for superconducting nanoelectronics

International Nuclear Information System (INIS)

Prepelita, A.; Zdravkov, V.; Morari, R.; Socrovisciuc, A.; Antropov, E.; Sidorenko, A.

2011-01-01

Full text: Elaborated advanced technology for superconducting spintronics - technological process, based on magnetron sputtering of the metallic films with non-metallic protective layers, yields significant improvement in superconducting properties of thin Nb films and Nb/CuNi nanostructures in comparison with common methods of films deposition. The developed advanced technological process is patented (Patent RM number 175 from 31.03.2010). First experimental observation of the double re-entrant superconductivity in superconductor/ ferromagnetic nanostructures (Nb/Cu 41 Ni 59 bilayers) in dependence on the thickness of the ferromagnetic layer (Published in : A.S. Sidorenko, V.I. Zdravkov, J. Kehrle, R.Morari, E.Antropov, G. Obermeier, S. Gsell, M. Schreck, C. Muller, V.V. Ryazanov, S. Horn, R. Tidecks, L.R. Tagirov. Extinction and recovery of superconductivity by interference in superconductor/ferromagnet bilayers. In: Nanoscale Phenomena . Fundamentals and Applications,Ed. by H.Hahn, A.Sidorenko, I.Tiginyanu, Springer, 2009 p.1-10. Perspectives of applications: design of a new generation of superconducting spintronic devices - high frequency operating superconducting spin-switch for telecommunication and computers. (author)

Torsion based universal MEMS logic device

KAUST Repository

Ilyas, Saad; Carreno, Armando Arpys Arevalo; Bayes, Ernesto; Foulds, Ian G.; Younis, Mohammad I.

2015-01-01

In this work we demonstrate torsion based complementary MEMS logic device, which is capable, of performing INVERTER, AND, NAND, NOR, and OR gates using one physical structure within an operating range of 0-10 volts. It can also perform XOR and XNOR with one access inverter using the same structure with different electrical interconnects. The paper presents modeling, fabrication and experimental calculations of various performance features of the device including lifetime, power consumption and resonance frequency. The fabricated device is 535 μm by 150 μm with a gap of 1.92 μm and a resonant frequency of 6.51 kHz. The device is capable of performing the switching operation with a frequency of 1 kHz.

Torsion based universal MEMS logic device

KAUST Repository

Ilyas, Saad

2015-10-28

In this work we demonstrate torsion based complementary MEMS logic device, which is capable, of performing INVERTER, AND, NAND, NOR, and OR gates using one physical structure within an operating range of 0-10 volts. It can also perform XOR and XNOR with one access inverter using the same structure with different electrical interconnects. The paper presents modeling, fabrication and experimental calculations of various performance features of the device including lifetime, power consumption and resonance frequency. The fabricated device is 535 μm by 150 μm with a gap of 1.92 μm and a resonant frequency of 6.51 kHz. The device is capable of performing the switching operation with a frequency of 1 kHz.

Analysis And Simulation Of Low Profile Planar Inverted - F Antenna Design For WLAN Operation In Portable Devices

Directory of Open Access Journals (Sweden)

Zaw Htet Lwin

2015-08-01

Full Text Available This paper presents a compact planar invertedF antenna PIFA design for WLAN operation in portable devices. The proposed design has size of 8 x 21 mm and provides peak directive gain of 5.78dBi with the peak return loss of -33.89dB and input impedance of 50.28amp8486. It covers a 10dB return loss bandwidth of 410MHz 2.37GHz 2.789GHz. Its VSWR varies from 1.96 to 1.93 within the antenna return loss bandwidth. As the dimension of the proposed antenna is very small the antenna is promising to be embedded within the different portable devices employing WiFi applications. This paper includes the return loss as a function of frequency with varying the different parameters VSWR input resistance radiation pattern and current distribution of the proposed antenna.

Spin-Polarized Hybridization at the interface between different 8-hydroxyquinolates and the Cr(001) surface

Science.gov (United States)

Wang, Jingying; Deloach, Andrew; Dougherty, Daniel B.; Dougherty Lab Team

Organic materials attract a lot of attention due to their promising applications in spintronic devices. It is realized that spin-polarized metal/organic interfacial hybridization plays an important role to improve efficiency of organic spintronic devices. Hybridized interfacial states help to increase spin injection at the interface. Here we report spin-resolved STM measurements of single tris(8-hydroxyquinolinato) aluminum molecules adsorbed on the antiferromagnetic Cr(001). Our observations show a spin-polarized interface state between Alq3 and Cr(001). Tris(8-hydroxyquinolinato) chromium has also been studied and compared with Alq3, which exhibits different spin-polarized hybridization with the Cr(001) surface state than Alq3. We attribute the differences to different character of molecular orbitals in the two different quinolates.

Antiferromagnetic phase of the gapless semiconductor V3Al

Science.gov (United States)

Jamer, M. E.; Assaf, B. A.; Sterbinsky, G. E.; Arena, D.; Lewis, L. H.; Saúl, A. A.; Radtke, G.; Heiman, D.

2015-03-01

Discovering new antiferromagnetic (AF) compounds is at the forefront of developing future spintronic devices without fringing magnetic fields. The AF gapless semiconducting D 03 phase of V3Al was successfully synthesized via arc-melting and annealing. The AF properties were established through synchrotron measurements of the atom-specific magnetic moments, where the magnetic dichroism reveals large and oppositely oriented moments on individual V atoms. Density functional theory calculations confirmed the stability of a type G antiferromagnetism involving only two-thirds of the V atoms, while the remaining V atoms are nonmagnetic. Magnetization, x-ray diffraction, and transport measurements also support the antiferromagnetism. This archetypal gapless semiconductor may be considered as a cornerstone for future spintronic devices containing AF elements.

High heat flux device of thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo.

1994-01-01

The present invention provides an equipments for high heat flux device (divertor) of a thermonuclear device, which absorbs thermal deformation during operation, has a high installation accuracy, and sufficiently withstands for thermal stresses. Namely, a heat sink member is joined to a structural base. Armour tiles are joined on the heat sink member. Cooling pipes are disposed between the heat sink member and the armour tiles. With such a constitution, the heat sink member using a highly heat conductive material having ductility, such as oxygen free copper, the cooling pipes using a material having excellent high temperature resistance and excellent elongation, such as aluminum-dispersed reinforced copper, and the armour tiles are completely joined on the structural base. Therefore, when thermal deformation tends to cause in the high heat flux device such as a divertor, cooling pipes cause no plastic deformation because of their high temperature resistance, but the heat sink member such as a oxygen free copper causes plastic deformation to absorb thermal deformation. As a result, the high heat flux device such as a divertor causes no deformation. (I.S.)

Spintronic Circuits: The Building Blocks of Spin-Based Computation

Directory of Open Access Journals (Sweden)

Roshan Warman

2016-10-01

Full Text Available In the most general situation, binary computation is implemented by means of microscopic logical gates known as transistors. According to Moore’s Law, the size of transistors will half every two years, and as these transistors reach their fundamental size limit, the quantum effects of the electrons passing through the transistors will be observed. Due to the inherent randomness of these quantum fluctuations, the basic binary logic will become uncontrollable. This project describes the basic principle governing quantum spin-based computing devices, which may provide an alternative to the conventional solid-state computing devices and circumvent the technological limitations of the current implementation of binary logic.

A field test of substance use screening devices as part of routine drunk-driving spot detection operating procedures in South Africa.

Science.gov (United States)

Matzopoulos, Richard; Lasarow, Avi; Bowman, Brett

2013-10-01

This pilot study aimed to test four substance use screening devices developed in Germany under local South African conditions and assess their utility for detecting driving under the influence of drugs (DUID) as part of the standard roadblock operations of local law enforcement agencies. The devices were used to screen a sample of motorists in the Gauteng and Western Cape provinces. The motorists were diverted for screening at roadblocks at the discretion of the law enforcement agencies involved, as per their standard operating procedures. Fieldworkers also administered a questionnaire that described the screening procedure, as well as information about vehicles, demographic information about the motorists and their attitudes to the screening process during testing. Motorists tested positive for breath alcohol in 28% of the 261 cases tested. Oral fluid was screened for drugs as per the standard calibrated cut-offs of all four devices. There were 14 cases where the under-influence drivers tested positive for alcohol and drugs simultaneously, but 14% of the 269 drivers drug-screened tested positive for drugs only. After alcohol, amphetamine, methamphetamine and cocaine were the most common drugs of impairment detected. The results suggest that under normal enforcement procedures only 76% of drivers impaired by alcohol and other drugs would have been detected. In more than 70% of cases the tests were administered within 5 min and this is likely to improve with more regular use. It was clear that the pilot screening process meets global testing standards. Although use of the screening devices alone would not serve as a basis for prosecution and provisions would need to be made for the confirmation of results through laboratory testing, rollout of this screening process would improve operational efficiency in at least two ways. Firstly, the accuracy of the tests will substantially decrease confirmatory test loads. Secondly, laboratory drug testing can be restricted to

Ultrathin magnetic structures IV applications of nanomagnetism

CERN Document Server

Heinrich, Bretislav

2004-01-01

The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. Volume III describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. The present volume (IV) deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is de...

Ultrathin magnetic structures III fundamentals of nanomagnetism

CERN Document Server

Bland, JAC

2004-01-01

The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. This volume describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. Volume IV deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be ...

Electrically tunable tunneling rectification magnetoresistance in magnetic tunneling junctions with asymmetric barriers.

Science.gov (United States)

Wang, Jing; Huang, Qikun; Shi, Peng; Zhang, Kun; Tian, Yufeng; Yan, Shishen; Chen, Yanxue; Liu, Guolei; Kang, Shishou; Mei, Liangmo

2017-10-26

The development of multifunctional spintronic devices requires simultaneous control of multiple degrees of freedom of electrons, such as charge, spin and orbit, and especially a new physical functionality can be realized by combining two or more different physical mechanisms in one specific device. Here, we report the realization of novel tunneling rectification magnetoresistance (TRMR), where the charge-related rectification and spin-dependent tunneling magnetoresistance are integrated in Co/CoO-ZnO/Co magnetic tunneling junctions with asymmetric tunneling barriers. Moreover, by simultaneously applying direct current and alternating current to the devices, the TRMR has been remarkably tuned in the range from -300% to 2200% at low temperature. This proof-of-concept investigation provides an unexplored avenue towards electrical and magnetic control of charge and spin, which may apply to other heterojunctions to give rise to more fascinating emergent functionalities for future spintronics applications.

Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

Science.gov (United States)

Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

2015-09-21

Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

Position measuring device

International Nuclear Information System (INIS)

Maeda, Kazuyuki; Takahashi, Shuichi; Maruyama, Mayumi

1998-01-01

The present invention provides a device capable of measuring accurate position and distance easily even at places where operator can not easily access, such as cell facilities for vitrifying radioactive wastes. Referring to a case of the vitrifying cell, an objective equipment settled in the cell is photographed by a photographing device. The image is stored in a position measuring device by way of an image input device. After several years, when the objective equipment is exchanged, a new objective equipment is photographed by a photographing device. The image is also stored in the position measuring device. The position measuring device compares the data of both of the images on the basis of pixel unit. Based on the image of the equipment before the exchange as a reference, extent of the displacement of the installation position of the equipment on the image after the exchange caused by installation error and manufacturing error is determined to decide the position of the equipment after exchange relative to the equipment before exchange. (I.S.)

Functional and operational requirements document : building 1012, Battery and Energy Storage Device Test Facility, Sandia National Laboratories, New Mexico.

Energy Technology Data Exchange (ETDEWEB)

Johns, William H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2013-11-01

This report provides an overview of information, prior studies, and analyses relevant to the development of functional and operational requirements for electrochemical testing of batteries and energy storage devices carried out by Sandia Organization 2546, Advanced Power Sources R&D. Electrochemical operations for this group are scheduled to transition from Sandia Building 894 to a new Building located in Sandia TA-II referred to as Building 1012. This report also provides background on select design considerations and identifies the Safety Goals, Stakeholder Objectives, and Design Objectives required by the Sandia Design Team to develop the Performance Criteria necessary to the design of Building 1012. This document recognizes the Architecture-Engineering (A-E) Team as the primary design entity. Where safety considerations are identified, suggestions are provided to provide context for the corresponding operational requirement(s).

Semiconductor terahertz technology devices and systems at room temperature operation

CERN Document Server

Carpintero, G; Hartnagel, H; Preu, S; Raisanen, A

2015-01-01

Key advances in Semiconductor Terahertz (THz) Technology now promises important new applications enabling scientists and engineers to overcome the challenges of accessing the so-called "terahertz gap".  This pioneering reference explains the fundamental methods and surveys innovative techniques in the generation, detection and processing of THz waves with solid-state devices, as well as illustrating their potential applications in security and telecommunications, among other fields. With contributions from leading experts, Semiconductor Terahertz Technology: Devices and Systems at Room Tempe

Synthesis and characterization of ZnO and Ni doped ZnO nanorods by thermal decomposition method for spintronics application

International Nuclear Information System (INIS)

Saravanan, R.; Santhi, Kalavathy; Sivakumar, N.; Narayanan, V.; Stephen, A.

2012-01-01

Zinc oxide nanorods and diluted magnetic semiconducting Ni doped ZnO nanorods were prepared by thermal decomposition method. This method is simple and cost effective. The decomposition temperature of acetate and formation of oxide were determined by TGA before the actual synthesis process. The X-ray diffraction result indicates the single phase hexagonal structure of zinc oxide. The transmission electron microscopy and scanning electron microscopy images show rod like structure of ZnO and Ni doped ZnO samples with the diameter ∼ 35 nm and the length in few micrometers. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The Ni doped ZnO exhibits room temperature ferromagnetism. This diluted magnetic semiconducting Ni doped ZnO nanorods finds its application in spintronics. - Highlights: ► The method used is very simple and cost effective compared to all other methods for the preparation DMS materials. ► ZnO and Ni doped ZnO nanorods ► Ferromagnetism at room temperature

Four-state ferroelectric spin-valve

Czech Academy of Sciences Publication Activity Database

Quindeau, A.; Fina, I.; Martí, Xavier; Apachitei, G.; Ferrer, P.; Nicklin, C.; Pippel, E.; Hesse, D.; Alexe, M.

2015-01-01

Roč. 5, May (2015), 09749 ISSN 2045-2322 Institutional support: RVO:68378271 Keywords : electronic and spintronic devices * ferroelectrics and multiferroics Subject RIV: BE - Theoretical Physics Impact factor: 5.228, year: 2015

Mobile biometric device (MBD) technology :

Energy Technology Data Exchange (ETDEWEB)

Aldridge, Chris D.

2013-06-01

Mobile biometric devices (MBDs) capable of both enrolling individuals in databases and performing identification checks of subjects in the field are seen as an important capability for military, law enforcement, and homeland security operations. The technology is advancing rapidly. The Department of Homeland Security Science and Technology Directorate through an Interagency Agreement with Sandia sponsored a series of pilot projects to obtain information for the first responder law enforcement community on further identification of requirements for mobile biometric device technology. Working with 62 different jurisdictions, including components of the Department of Homeland Security, Sandia delivered a series of reports on user operation of state-of-the-art mobile biometric devices. These reports included feedback information on MBD usage in both operational and exercise scenarios. The findings and conclusions of the project address both the limitations and possibilities of MBD technology to improve operations. Evidence of these possibilities can be found in the adoption of this technology by many agencies today and the cooperation of several law enforcement agencies in both participating in the pilot efforts and sharing of information about their own experiences in efforts undertaken separately.

Plant state display device

International Nuclear Information System (INIS)

Kadota, Kazuo; Ito, Toshiichiro.

1994-01-01

The device of the present invention conducts information processing suitable for a man to solve a problem in a plant such as a nuclear power plant incorporating a great amount of information, where safety is required and provides information to an operator. Namely, theories and rules with respect to the flow and balanced state of materials and energy upon plant start-up, and a vapor cycle of operation fluids are symbolized and displayed on the display screen of the device. Then, the display of the plant information suitable to the information processing for a man to dissolve problems is provided. Accordingly, a mechanism for analyzing a purpose of the plant is made more definite, thereby enabling to prevent an erroneous judgement of an operator and occurrence of plant troubles. In addition, a simular effect can also be expected when the theories and rules with respect to the flow and the balanced state of materials and energy and thermohydrodynamic behavior of the operation fluids in a state of after-heat removing operation during shutdown of the plant are symbolized and displayed. (I.S.)

New photonic devices for ultrafast pulse processing operating on the basis of the diffraction-dispersion analogy

Energy Technology Data Exchange (ETDEWEB)

Torres-Company, Victor; Minguez-Vega, Gladys; Climent, Vicent; Lands, Jesus [GROC-UJI, Departament de Fisica, Universitat Jaume I, 12080 Castello (Spain); Andres, Pedro [Departament d' Optica, Universitat de Valencia, 46100 Burjassot (Spain)], E-mail: lancis@fca.uji.es

2008-11-01

The space-time analogy is a well-known topic within wave optics that brings together some results from beam diffraction and pulse dispersion. On the above basis, and taking as starting point some classical concepts in Optics, several photonic devices have been proposed during the last few years with application in rapidly evolving fields such as ultrafast (femtosecond) optics or RF and microwave signal processing. In this contribution, we briefly review the above ideas with particular emphasis in the generation of trains of ultrafast pulses from periodic modulation of the phase of a CW laser source. This is the temporal analogue of Fresnel diffraction by a pure phase grating. Finally, we extend the analogy to the partially coherent case, what enables us to design an original technique for wavelength-to-time mapping of the spectrum of a temporally stationary source. Results of laboratory experiments concerning the generation of user-defined radio-frequency waveforms and filtering of microwave signals will be shown. The devices are operated with low-cost incoherent sources.

Remote media vision-based computer input device

Science.gov (United States)

Arabnia, Hamid R.; Chen, Ching-Yi

1991-11-01

In this paper, we introduce a vision-based computer input device which has been built at the University of Georgia. The user of this system gives commands to the computer without touching any physical device. The system receives input through a CCD camera; it is PC- based and is built on top of the DOS operating system. The major components of the input device are: a monitor, an image capturing board, a CCD camera, and some software (developed by use). These are interfaced with a standard PC running under the DOS operating system.

Development of an integrated pointing device driver for the disabled.

Science.gov (United States)

Shih, Ching-Hsiang; Shih, Ching-Tien

2010-01-01

To help people with disabilities such as those with spinal cord injury (SCI) to effectively utilise commercial pointing devices to operate computers. This study proposes a novel method to integrate the functions of commercial pointing devices. Utilising software technology to develop an integrated pointing device driver (IPDD) for a computer operating system. The proposed IPDD has the following benefits: (1) it does not require additional hardware cost or circuit preservations, (2) it supports all standard interfaces of commercial pointing devices, including PS/2, USB and wireless interfaces and (3) it can integrate any number of devices. The IPDD can be selected and combined according to their physical restriction. The IPDD is a novel method of integrating commercial pointing devices. Through IPDD, people with disabilities can choose a suitable combination of commercial pointing devices to achieve full cursor control and optimise operational performance. In contrast with previous studies, the software-based solution does not require additional hardware or circuit preservations, and it can support unlimited devices. In summary, the IPDD has the benefits of flexibility, low cost and high-device compatibility.

Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

KAUST Repository

Cheng, Yingchun; Zhang, Q. Y.; Schwingenschlö gl, Udo

2014-01-01

We demonstrate that valley polarization can be induced and controlled in semiconducting single-layer transition-metal dichalcogenides by magnetic doping, which is important for spintronics, valleytronics, and photonics devices. As an example, we

Operation monitor for plant equipment

International Nuclear Information System (INIS)

Kondo, Tetsufumi; Kanemoto, Shigeru.

1991-01-01

In a nuclear power plant, states of each of equipment in the plant are monitored accurately even under such a operation condition that the power is changed. That is, the fundamental idea is based on a model comparison method. A deviation between an output signal upon normal plant state obtained in a forecasting model device and that of the objective equipment in the plant are compared with a predetermined value. The result of the comparison is inputted to an alarm device to alarm the abnormality of the states of the equipment to an operator. The device of the present invention thus constituted can monitor the abnormality of the operation of equipment accurately even under such a condition that a power level fluctuates. As a result, it can remarkably contribute to mitigate operator's monitoring operation under the condition such as during load following operation. (I.S.)

Control Board Digital Interface Input Devices – Touchscreen, Trackpad, or Mouse?

Energy Technology Data Exchange (ETDEWEB)

Thomas A. Ulrich; Ronald L. Boring; Roger Lew

2015-08-01

The authors collaborated with a power utility to evaluate input devices for use in the human system interface (HSI) for a new digital Turbine Control System (TCS) at a nuclear power plant (NPP) undergoing a TCS upgrade. A standalone dynamic software simulation of the new digital TCS and a mobile kiosk were developed to conduct an input device study to evaluate operator preference and input device effectiveness. The TCS software presented the anticipated HSI for the TCS and mimicked (i.e., simulated) the turbine systems’ responses to operator commands. Twenty-four licensed operators from the two nuclear power units participated in the study. Three input devices were tested: a trackpad, mouse, and touchscreen. The subjective feedback from the survey indicates the operators preferred the touchscreen interface. The operators subjectively rated the touchscreen as the fastest and most comfortable input device given the range of tasks they performed during the study, but also noted a lack of accuracy for selecting small targets. The empirical data suggest the mouse input device provides the most consistent performance for screen navigation and manipulating on screen controls. The trackpad input device was both empirically and subjectively found to be the least effective and least desired input device.

Assembly For Moving a Robotic Device Along Selected Axes

Science.gov (United States)

Nowlin, Brentley Craig (Inventor); Koch, Lisa Danielle (Inventor)

2001-01-01

An assembly for moving a robotic device along selected axes includes a programmable logic controller (PLC) for controlling movement of the device along selected axes to effect movement of the device to a selected disposition. The PLC includes a plurality of single axis motion control modules, and a central processing unit (CPU) in communication with the motion control modules. A human-machine interface is provided for operator selection of configurations of device movements and is in communication with the CPU. A motor drive is in communication with each of the motion control modules and is operable to effect movement of the device along the selected axes to obtain movement of the device to the selected disposition.

Spiking neuron devices consisting of single-flux-quantum circuits

International Nuclear Information System (INIS)

Hirose, Tetsuya; Asai, Tetsuya; Amemiya, Yoshihito

2006-01-01

Single-flux-quantum (SFQ) circuits can be used for making spiking neuron devices, which are useful elements for constructing intelligent, brain-like computers. The device we propose is based on the leaky integrate-and-fire neuron (IFN) model and uses a SFQ pulse as an action signal or a spike of neurons. The operation of the neuron device is confirmed by computer simulator. It can operate with a short delay of 100 ps or less and is the highest-speed neuron device ever reported

Electronic security device

Science.gov (United States)

Eschbach, Eugene A.; LeBlanc, Edward J.; Griffin, Jeffrey W.

1992-01-01

The present invention relates to a security device having a control box (12) containing an electronic system (50) and a communications loop (14) over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system (50) and a detection module (72) capable of registering changes in the voltage and phase of the signal transmitted over the loop.

Electronic security device