WorldWideScience

Sample records for include electronic materials

  1. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  2. Modern electronic materials

    CERN Document Server

    Watkins, John B

    2013-01-01

    Modern Electronic Materials focuses on the development of electronic components. The book first discusses the history of electronic components, including early developments up to 1900, developments up to World War II, post-war developments, and a comparison of present microelectric techniques. The text takes a look at resistive materials. Topics include resistor requirements, basic properties, evaporated film resistors, thick film resistors, and special resistors. The text examines dielectric materials. Considerations include basic properties, evaporated dielectric materials, ceramic dielectri

  3. CONFERENCE SUMMARY: Summary and comment on superconducting analogue electronics research, including materials and fabrication, as presented at ISEC 07

    Science.gov (United States)

    Foley, C. P.

    2007-11-01

    The main theme at ISEC 2007 for superconducting materials, fabrication and analogue electronics was the description of incremental developments, including a few new directions that indicate breakthroughs in this area of research. The work on applications focused on their cost-benefit analysis (in order to improve their appeal), the development of simpler systems, making more of the data collected, improving packaging and being responsive to the power handling requirements for commercial systems. All papers presenting this level of research highlighted the importance of obtaining all the necessary details in order to investigate analogue devices and the effectiveness and commercial viability of their systems. This stage of development is important if we are to achieve the transition of superconducting electronics from the laboratory to commercial use. There were some exciting disruptive breakthroughs reported. These were in the areas of nano-SQUIDs, rotating gradiometers, superconducting scanning tunnelling microscopy (Hayashi et al) and the potential of superconducting photonics using optical interfaces with superconducting vortex flow transistors, for example. The materials research in low (LTS), high (HTS) and medium (MTS) critical temperature superconductors was reported. In LTS, nitrides emerged as important materials for use as new tunnel barriers, either insulating or semiconducting. Papers on BaN, NbN, TaN, GaN and Nb-Si superconducting materials were also presented. The MTS material of MgB2 is still under development (Zhao et al). There were also new research groups from South Africa and Turkey attending the conference. The fabrication research presented covered the areas of critical current Ic spread, which is still an issue in reducing the reproducibility of Josephson junctions, a 150 mm process for Nb/Al-AlOx/Nb and methods to improve barrier layers using both new materials and smooth surfaces at thin film interfaces (Du et al). New methods to make sub

  4. Advances in electronic materials

    CERN Document Server

    Kasper, Erich; Grimmeiss, Hermann G

    2008-01-01

    This special-topic volume, Advances in Electronic Materials, covers various fields of materials research such as silicon, silicon-germanium hetero-structures, high-k materials, III-V semiconductor alloys and organic materials, as well as nano-structures for spintronics and photovoltaics. It begins with a brief summary of the formative years of microelectronics; now the keystone of information technology. The latter remains one of the most important global technologies, and is an extremely complex subject-area. Although electronic materials are primarily associated with computers, the internet

  5. Polymer electronic devices and materials.

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, William Kent; Baca, Paul Martin; Dirk, Shawn M.; Anderson, G. Ronald; Wheeler, David Roger

    2006-01-01

    Polymer electronic devices and materials have vast potential for future microsystems and could have many advantages over conventional inorganic semiconductor based systems, including ease of manufacturing, cost, weight, flexibility, and the ability to integrate a wide variety of functions on a single platform. Starting materials and substrates are relatively inexpensive and amenable to mass manufacturing methods. This project attempted to plant the seeds for a new core competency in polymer electronics at Sandia National Laboratories. As part of this effort a wide variety of polymer components and devices, ranging from simple resistors to infrared sensitive devices, were fabricated and characterized. Ink jet printing capabilities were established. In addition to promising results on prototype devices the project highlighted the directions where future investments must be made to establish a viable polymer electronics competency.

  6. Armor systems including coated core materials

    Science.gov (United States)

    Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  7. Ion beam processing of advanced electronic materials

    International Nuclear Information System (INIS)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases

  8. Ion beam processing of advanced electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  9. Nanostructured electronic and magnetic materials

    Indian Academy of Sciences (India)

    Research and development in nanostructured materials is one of the most intensely studied areas in science. As a result of concerted R & D efforts, nanostructured electronic and magnetic materials have achieved commercial success. Specific examples of novel industrially important nanostructured electronic and magnetic ...

  10. Good Security Practices for Electronic Commerce, Including Electronic Data Interchange

    National Research Council Canada - National Science Library

    Saltman, Roy

    1993-01-01

    Electronic commerce (EC) is the use of documents in electronic form, rather than paper, for carrying out functions of business or government that require interchange of information, obligations, or monetary value between organizations...

  11. Energetic materials research using scanning electron microscopy

    NARCIS (Netherlands)

    Elshout, J.J.M.H. van den; Duvalois, W.; Benedetto, G.L. Di; Bouma, R.H.B.; Heijden, A.E.D.M. van der

    2016-01-01

    A key-technique for the research of energetic materials is scanning electron microscopy. In this paper several examples are given of characterization studies on energetic materials, including a solid composite propellant formulation. Results of the characterization of energetic materials using

  12. Electronics Devices and Materials

    Science.gov (United States)

    2008-03-17

    bonding. The direct bonded wafers will include substrates of silicon, silicon geranium, silicon carbide, gallium arsenide, gallium antimonide and other Il...Acronyms AL ................... Aluminum A LN......... Aluminum Nitride A-Si .................... Silicon AU ..................... Gold CIGS

  13. Noncovalent Interactions in Organic Electronic Materials

    KAUST Repository

    Ravva, Mahesh Kumar

    2017-06-29

    In this chapter, we provide an overview of how noncovalent interactions, determined by the chemical structure of π-conjugated molecules and polymers, govern essential aspects of the electronic, optical, and mechanical characteristics of organic semiconductors. We begin by describing general aspects of materials design, including the wide variety of chemistries exploited to control the electronic and optical properties of these materials. We then discuss explicit examples of how the study of noncovalent interactions can provide deeper chemical insights that can improve the design of new generations of organic electronic materials.

  14. Nanostructured electronic and magnetic materials

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Nanostructured systems are useful in tailoring the magnetic, optical and electronic properties of materials. It is obvious that .... A hysteresis effect is produced and forms a hysteresis loop, this loop is a key tool in the quantitative analysis of ..... below the secondary crystallization temperature, in controlled time. Doing so yields ...

  15. Transmission Electron Microscopy and Diffractometry of Materials

    CERN Document Server

    Fultz, Brent

    2013-01-01

    This book explains concepts of transmission electron microscopy (TEM) and x-ray diffractometry (XRD) that are important for the characterization of materials. The fourth edition adds important new techniques of TEM such as electron tomography, nanobeam diffraction, and geometric phase analysis. A new chapter on neutron scattering completes the trio of x-ray, electron and neutron diffraction. All chapters were updated and revised for clarity. The book explains the fundamentals of how waves and wavefunctions interact with atoms in solids, and the similarities and differences of using x-rays, electrons, or neutrons for diffraction measurements. Diffraction effects of crystalline order, defects, and disorder in materials are explained in detail. Both practical and theoretical issues are covered. The book can be used in an introductory-level or advanced-level course, since sections are identified by difficulty. Each chapter includes a set of problems to illustrate principles, and the extensive Appendix includes la...

  16. Nonlinearity in structural and electronic materials

    International Nuclear Information System (INIS)

    Bishop, A.R.; Beardmore, K.M.; Ben-Naim, E.

    1997-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project strengthens a nonlinear technology base relevant to a variety of problems arising in condensed matter and materials science, and applies this technology to those problems. In this way the controlled synthesis of, and experiments on, novel electronic and structural materials provide an important focus for nonlinear science, while nonlinear techniques help advance the understanding of the scientific principles underlying the control of microstructure and dynamics in complex materials. This research is primarily focused on four topics: (1) materials microstructure: growth and evolution, and porous media; (2) textures in elastic/martensitic materials; (3) electro- and photo-active polymers; and (4) ultrafast photophysics in complex electronic materials. Accomplishments included the following: organization of a ''Nonlinear Materials'' seminar series and international conferences including ''Fracture, Friction and Deformation,'' ''Nonequilibrium Phase Transitions,'' and ''Landscape Paradigms in Physics and Biology''; invited talks at international conference on ''Synthetic Metals,'' ''Quantum Phase Transitions,'' ''1996 CECAM Euroconference,'' and the 1995 Fall Meeting of the Materials Research Society; large-scale simulations and microscopic modeling of nonlinear coherent energy storage at crack tips and sliding interfaces; large-scale simulation and microscopic elasticity theory for precursor microstructure and dynamics at solid-solid diffusionless phase transformations; large-scale simulation of self-assembling organic thin films on inorganic substrates; analysis and simulation of smoothing of rough atomic surfaces; and modeling and analysis of flux pattern formation in equilibrium and nonequilibrium Josephson junction arrays and layered superconductors

  17. Electronic, magnetic, and optical materials

    CERN Document Server

    Fulay, Pradeep

    2013-01-01

    Technological aspects of ferroelectric, piezoelectric and pyroelectric materials are discussed in detail, in a way that should allow the reader to select an optimal material for a particular application. The basics of magnetostatics are described clearly, as are a wide range of magnetic properties of materials … .-Tony Harker, Department of Physics and Astronomy, University College London

  18. High energy electron irradiation of flowable materials

    International Nuclear Information System (INIS)

    Offermann, B.P.

    1975-01-01

    In order to efficiently irradiate a flowable material with high energy electrons, a hollow body is disposed in a container for the material and the material is caused to flow in the form of a thin layer across a surface of the body from or to the interior of the container while the material flowing across the body surface is irradiated. (U.S.)

  19. Physics of electronic materials principles and applications

    CERN Document Server

    Rammer, Jorgen

    2017-01-01

    Adopting a uniquely pedagogical approach, this comprehensive textbook on the quantum mechanics of semiconductor materials and devices focuses on the materials, components and devices themselves whilst incorporating a substantial amount of fundamental physics related to condensed matter theory and quantum mechanics. Written primarily for advanced undergraduate students in physics and engineering, this book can also be used as a supporting text for introductory quantum mechanics courses, and will be of interest to anyone interested in how electronic devices function at a fundamental level. Complete with numerous exercises, and with all the necessary mathematics and physics included in appendices, this book guides the reader seamlessly through the principles of quantum mechanics and the quantum theory of metals and semiconductors, before describing in detail how devices are exploited within electric circuits and in the hardware of computers, for example as amplifiers, switches and transistors. Includes nume...

  20. Electron-trapping polycrystalline materials with negative electron affinity.

    Science.gov (United States)

    McKenna, Keith P; Shluger, Alexander L

    2008-11-01

    The trapping of electrons by grain boundaries in semiconducting and insulating materials is important for a wide range of physical problems, for example, relating to: electroceramic materials with applications as sensors, varistors and fuel cells, reliability issues for solar cell and semiconductor technologies and electromagnetic seismic phenomena in the Earth's crust. Surprisingly, considering their relevance for applications and abundance in the environment, there have been few experimental or theoretical studies of the electron trapping properties of grain boundaries in highly ionic materials such as the alkaline earth metal oxides and alkali halides. Here we demonstrate, by first-principles calculations on MgO, LiF and NaCl, a qualitatively new type of electron trapping at grain boundaries. This trapping is associated with the negative electron affinity of these materials and is unusual as the electron is confined in the empty space inside the dislocation cores.

  1. Environmental testing techniques for electronics and materials

    CERN Document Server

    Dummer, Geoffrey W A; Fry, D W; Higinbotham, W

    2013-01-01

    Environmental Testing Techniques for Electronics and Materials reviews environmental testing techniques for evaluating the performance of electronic equipment, components, and materials. Environmental test planning, test methods, and instrumentation are described, along with the general environmental conditions under which equipment must operate. This book is comprised of 15 chapters and begins by explaining why environmental testing is necessary and describing the environment in which electronics must operate. The next chapter considers how an environmental test plan is designed; the methods

  2. A hydrodynamic model for granular material flows including segregation effects

    Directory of Open Access Journals (Sweden)

    Gilberg Dominik

    2017-01-01

    Full Text Available The simulation of granular flows including segregation effects in large industrial processes using particle methods is accurate, but very time-consuming. To overcome the long computation times a macroscopic model is a natural choice. Therefore, we couple a mixture theory based segregation model to a hydrodynamic model of Navier-Stokes-type, describing the flow behavior of the granular material. The granular flow model is a hybrid model derived from kinetic theory and a soil mechanical approach to cover the regime of fast dilute flow, as well as slow dense flow, where the density of the granular material is close to the maximum packing density. Originally, the segregation model has been formulated by Thornton and Gray for idealized avalanches. It is modified and adapted to be in the preferred form for the coupling. In the final coupled model the segregation process depends on the local state of the granular system. On the other hand, the granular system changes as differently mixed regions of the granular material differ i.e. in the packing density. For the modeling process the focus lies on dry granular material flows of two particle types differing only in size but can be easily extended to arbitrary granular mixtures of different particle size and density. To solve the coupled system a finite volume approach is used. To test the model the rotational mixing of small and large particles in a tumbler is simulated.

  3. A hydrodynamic model for granular material flows including segregation effects

    Science.gov (United States)

    Gilberg, Dominik; Klar, Axel; Steiner, Konrad

    2017-06-01

    The simulation of granular flows including segregation effects in large industrial processes using particle methods is accurate, but very time-consuming. To overcome the long computation times a macroscopic model is a natural choice. Therefore, we couple a mixture theory based segregation model to a hydrodynamic model of Navier-Stokes-type, describing the flow behavior of the granular material. The granular flow model is a hybrid model derived from kinetic theory and a soil mechanical approach to cover the regime of fast dilute flow, as well as slow dense flow, where the density of the granular material is close to the maximum packing density. Originally, the segregation model has been formulated by Thornton and Gray for idealized avalanches. It is modified and adapted to be in the preferred form for the coupling. In the final coupled model the segregation process depends on the local state of the granular system. On the other hand, the granular system changes as differently mixed regions of the granular material differ i.e. in the packing density. For the modeling process the focus lies on dry granular material flows of two particle types differing only in size but can be easily extended to arbitrary granular mixtures of different particle size and density. To solve the coupled system a finite volume approach is used. To test the model the rotational mixing of small and large particles in a tumbler is simulated.

  4. Surfaces and interfaces of electronic materials

    CERN Document Server

    Brillson, Leonard J

    2012-01-01

    An advanced level textbook covering geometric, chemical, and electronic structure of electronic materials, and their applications to devices based on semiconductor surfaces, metal-semiconductor interfaces, and semiconductor heterojunctions. Starting with the fundamentals of electrical measurements on semiconductor interfaces, it then describes the importance of controlling macroscopic electrical properties by atomic-scale techniques. Subsequent chapters present the wide range of surface and interface techniques available to characterize electronic, optical, chemical, and structural propertie

  5. Composite material including nanocrystals and methods of making

    Science.gov (United States)

    Bawendi, Moungi G.; Sundar, Vikram C.

    2010-04-06

    Temperature-sensing compositions can include an inorganic material, such as a semiconductor nanocrystal. The nanocrystal can be a dependable and accurate indicator of temperature. The intensity of emission of the nanocrystal varies with temperature and can be highly sensitive to surface temperature. The nanocrystals can be processed with a binder to form a matrix, which can be varied by altering the chemical nature of the surface of the nanocrystal. A nanocrystal with a compatibilizing outer layer can be incorporated into a coating formulation and retain its temperature sensitive emissive properties.

  6. Transparent oxide electronics from materials to devices

    CERN Document Server

    Martins, Rodrigo; Barquinha, Pedro; Pereira, Luis

    2012-01-01

    Transparent electronics is emerging as one of the most promising technologies for the next generation of electronic products, away from the traditional silicon technology. It is essential for touch display panels, solar cells, LEDs and antistatic coatings. The book describes the concept of transparent electronics, passive and active oxide semiconductors, multicomponent dielectrics and their importance for a new era of novel electronic materials and products. This is followed by a short history of transistors, and how oxides have revolutionized this field. It concludes with a glance at lo

  7. New correlated electron physics from new materials

    International Nuclear Information System (INIS)

    Maple, M.B.; Baumbach, R.E.; Hamlin, J.J.; Zocco, D.A.; Taylor, B.J.; Butch, N.P.; Jeffries, J.R.; Weir, S.T.; Sales, B.C.; Mandrus, D.; McGuire, M.A.; Sefat, A.S.; Jin, R.; Vohra, Y.K.; Chu, J.-H.; Fisher, I.R.

    2009-01-01

    Many important advances in the physics of strongly correlated electron systems have been driven by the development of new materials: for instance the filled skutterudites MT 4 X 12 (M=alkali metal, alkaline earth, lanthanide, or actinide; T=Fe, Ru, or Os; X=P, As, or Sb), certain lanthanide and actinide intermetallic compounds such as URu 2-x Re x Si 2 and CeTIn 5 (T=Co, Rh, or Ir), and layered oxypnictides and related materials. These types of complex multinary d- and f-electron compounds have proven to be a vast reservoir of novel strongly correlated electron ground states and phenomena. In these materials, the occurrence of such a wide range of ground states and phenomena arises from a delicate interplay between competing interactions that can be tuned by partial or complete substitution of one element for another, as well as the application of pressure, and magnetic fields, resulting in rich and complex electronic phase diagrams in the hyperspace of temperature, chemical composition, pressure and magnetic field. It seems clear that this type of 'materials driven physics' will continue to play a central role in the development of the field of strongly correlated electron systems in the future, through the discovery of new materials that exhibit unexpected phenomena and experiments on known materials in an effort to optimize their physical properties and test relevant theories.

  8. Cladding material, tube including such cladding material and methods of forming the same

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2016-03-01

    A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.

  9. Materials and applications of bioresorbable electronics

    Science.gov (United States)

    Huang, Xian

    2018-01-01

    Bioresorbable electronics is a new type of electronics technology that can potentially lead to biodegradable and dissolvable electronic devices to replace current built-to-last circuits predominantly used in implantable devices and consumer electronics. Such devices dissolve in an aqueous environment in time periods from seconds to months, and generate biological safe products. This paper reviews materials, fabrication techniques, and applications of bioresorbable electronics, and aims to inspire more revolutionary bioresorbable systems that can generate broader social and economic impact. Existing challenges and potential solutions in developing bioresorbable electronics have also been presented to arouse more joint research efforts in this field to build systematic technology framework. Project supported by the National Natural Science Foundation of China (No. 61604108) and the Natural Science Foundation of Tianjin (No. 16JCYBJC40600).

  10. Lipid Bilayer Formation on Organic Electronic Materials

    KAUST Repository

    Zhang, Yi

    2018-04-23

    The lipid bilayer is the elemental structure of cell membrane, forming a stable barrier between the interior and exterior of the cell while hosting membrane proteins that enable selective transport of biologically important compounds and cellular recognition. Monitoring the quality and function of lipid bilayers is thus essential and can be performed using electrically active substrates that allow for transduction of signals. Such a promising electronic transducer material is the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) which has provided a plethora of novel bio transducing architectures. The challenge is however in assembling a bilayer on the conducting polymer surface, which is defect-free and has high mobility. Herein, we investigate the fusion of zwitterionic vesicles on a variety of PEDOT:PSS films, but also on an electron transporting, negatively charged organic semiconductor, in order to understand the surface properties that trigger vesicle fusion. The PEDOT:PSS films are prepared from dispersions containing different concentrations of ethylene glycol included as a formulation additive, which gives a handle to modulate surface physicochemical properties without a compromise on the chemical composition. The strong correlation between the polarity of the surface, the fusion of vesicles and the mobility of the resulting bilayer aides extracting design principles for the development of future conducting polymers that will enable the formation of lipid bilayers.

  11. Runaway-electron-materials interaction studies

    International Nuclear Information System (INIS)

    Bolt, H.; Miyahara, A.

    1990-03-01

    During the operation of magnetic fusion devices it has been frequently observed that runaway electrons can cause severe damage to plasma facing components. The energy of the runaway electrons could possibly reach several 100 MeV in a next generation device with an energy content in the plasma in the order of 100 MJ. In this study effects of high energy electron - materials interaction were determined by laboratory experiments using particle beam facilities, i.e. the Electron Linear Accelerator of the Institute of Scientific and Industrial Research of Osaka University and the 10 MW Neutral Beam Injection Test Stand of the National Institute for Fusion Science. The experiments and further analyses lead to a first assessment of the damage thresholds of plasma facing materials and components under runaway electron impact. It was found that metals (stainless steel, molybdenum, tungsten) showed grain growth, crack formation and/or melting already below the threshold for crack initiation on graphite (14-33 MJ/m 2 ). Strong erosion of carbon materials would occur above 100 MJ/m 2 . Damage to metal coolant channels can occur already below an energy deposition of 100 MJ/m 2 . The energy deposited in the metal coolant channels depends on the thickness of the plasma facing carbon material D, with the shielding efficiency S of carbon approximately as S∼D 1.15 . (author) 304 refs. 12 tabs. 59 figs

  12. Materials and mechanics for stretchable electronics.

    Science.gov (United States)

    Rogers, John A; Someya, Takao; Huang, Yonggang

    2010-03-26

    Recent advances in mechanics and materials provide routes to integrated circuits that can offer the electrical properties of conventional, rigid wafer-based technologies but with the ability to be stretched, compressed, twisted, bent, and deformed into arbitrary shapes. Inorganic and organic electronic materials in microstructured and nanostructured forms, intimately integrated with elastomeric substrates, offer particularly attractive characteristics, with realistic pathways to sophisticated embodiments. Here, we review these strategies and describe applications of them in systems ranging from electronic eyeball cameras to deformable light-emitting displays. We conclude with some perspectives on routes to commercialization, new device opportunities, and remaining challenges for research.

  13. Molecular modeling and multiscaling issues for electronic material applications

    CERN Document Server

    Iwamoto, Nancy; Yuen, Matthew; Fan, Haibo

    Volume 1 : Molecular Modeling and Multiscaling Issues for Electronic Material Applications provides a snapshot on the progression of molecular modeling in the electronics industry and how molecular modeling is currently being used to understand material performance to solve relevant issues in this field. This book is intended to introduce the reader to the evolving role of molecular modeling, especially seen through the eyes of the IEEE community involved in material modeling for electronic applications.  Part I presents  the role that quantum mechanics can play in performance prediction, such as properties dependent upon electronic structure, but also shows examples how molecular models may be used in performance diagnostics, especially when chemistry is part of the performance issue.  Part II gives examples of large-scale atomistic methods in material failure and shows several examples of transitioning between grain boundary simulations (on the atomistic level)and large-scale models including an example ...

  14. Electronic Structure of Strongly Correlated Materials

    CERN Document Server

    Anisimov, Vladimir

    2010-01-01

    Electronic structure and physical properties of strongly correlated materials containing elements with partially filled 3d, 4d, 4f and 5f electronic shells is analyzed by Dynamical Mean-Field Theory (DMFT). DMFT is the most universal and effective tool used for the theoretical investigation of electronic states with strong correlation effects. In the present book the basics of the method are given and its application to various material classes is shown. The book is aimed at a broad readership: theoretical physicists and experimentalists studying strongly correlated systems. It also serves as a handbook for students and all those who want to be acquainted with fast developing filed of condensed matter physics.

  15. Surface and Interface Physics of Correlated Electron Materials

    Energy Technology Data Exchange (ETDEWEB)

    Millis, Andrew [Columbia Univ., New York, NY (United States)

    2004-09-01

    The {\\it Surface and Interface Physics of Correlated Electron Materials} research program provided conceptual understanding of and theoretical methodologies for understanding the properties of surfaces and interfaces involving materials exhibiting strong electronic correlations. The issues addressed in this research program are important for basic science, because the behavior of correlated electron superlattices is a crucial challenge to and crucial test of our understanding of the grand-challenge problem of correlated electron physics and are important for our nation's energy future because correlated interfaces offer opportunities for the control of phenomena needed for energy and device applications. Results include new physics insights, development of new methods, and new predictions for materials properties.

  16. Reaction behaviour of reactor materials, including concrete during core meltdown

    International Nuclear Information System (INIS)

    Holleck, H.; Hofmann, P.; Skokan, A.

    1976-01-01

    The problems dealt with in the studies on the material behaviour of core meltdowns are sketched, and an outline is given on the experimental investigations now in progress. These studies aim at establishing a model which is as realistic as possible, and the paper tries to show that knowledge on the reaction behaviour is a basic prerequisite for this. (orig./TK) [de

  17. Thermal and Electrical Properties of Nanocomposites, Including Material Properties

    NARCIS (Netherlands)

    Kochetov, R.

    2012-01-01

    The research described in this thesis is part of a state-funded IOP-EMVT project in cooperation with industrial companies, aiming at the design, assessment and implementation of new, environmental friendly (e.g. oil and SF6 - free) solid dielectric materials. A large disadvantage of solid polymer

  18. Nature-Inspired Structural Materials for Flexible Electronic Devices.

    Science.gov (United States)

    Liu, Yaqing; He, Ke; Chen, Geng; Leow, Wan Ru; Chen, Xiaodong

    2017-10-25

    Exciting advancements have been made in the field of flexible electronic devices in the last two decades and will certainly lead to a revolution in peoples' lives in the future. However, because of the poor sustainability of the active materials in complex stress environments, new requirements have been adopted for the construction of flexible devices. Thus, hierarchical architectures in natural materials, which have developed various environment-adapted structures and materials through natural selection, can serve as guides to solve the limitations of materials and engineering techniques. This review covers the smart designs of structural materials inspired by natural materials and their utility in the construction of flexible devices. First, we summarize structural materials that accommodate mechanical deformations, which is the fundamental requirement for flexible devices to work properly in complex environments. Second, we discuss the functionalities of flexible devices induced by nature-inspired structural materials, including mechanical sensing, energy harvesting, physically interacting, and so on. Finally, we provide a perspective on newly developed structural materials and their potential applications in future flexible devices, as well as frontier strategies for biomimetic functions. These analyses and summaries are valuable for a systematic understanding of structural materials in electronic devices and will serve as inspirations for smart designs in flexible electronics.

  19. Materials and Reliability Handbook for Semiconductor Optical and Electron Devices

    CERN Document Server

    Pearton, Stephen

    2013-01-01

    Materials and Reliability Handbook for Semiconductor Optical and Electron Devices provides comprehensive coverage of reliability procedures and approaches for electron and photonic devices. These include lasers and high speed electronics used in cell phones, satellites, data transmission systems and displays. Lifetime predictions for compound semiconductor devices are notoriously inaccurate due to the absence of standard protocols. Manufacturers have relied on extrapolation back to room temperature of accelerated testing at elevated temperature. This technique fails for scaled, high current density devices. Device failure is driven by electric field or current mechanisms or low activation energy processes that are masked by other mechanisms at high temperature. The Handbook addresses reliability engineering for III-V devices, including materials and electrical characterization, reliability testing, and electronic characterization. These are used to develop new simulation technologies for device operation and ...

  20. Synaptic electronics: materials, devices and applications.

    Science.gov (United States)

    Kuzum, Duygu; Yu, Shimeng; Wong, H-S Philip

    2013-09-27

    In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented.

  1. Electron beam melting of bearing materials

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmied, G.; Schuler, A. (Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Elektrotechnik); Elsinger, G.; Koroschetz, F. (MIBA Gleitlager AG, Laakirchen (Austria)); Tschegg, E.K. (Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik)

    1990-06-01

    This paper reports on a surface treatment method for the bearing materials AlSn6 which permits the use of this material without the overlay usually required. Microstructural refinement is achieved by means of a surface melting technique using an electron beam with successive rapid solidification. Extremely fine tin precipitates are formed in the melted surface layer which lead to significantly better tribological properties of the bearing material. Tests compared the tribological properties for AlSn6 bearings treated by the surface melting technique with those of untreated bearings. Whereas all untreated bearings failed by seizure after only 2 h of testing, 30% of the tested bearings which had been surface melted survived the entire testing program without damage.

  2. Advanced electrical and electronics materials processes and applications

    CERN Document Server

    Gupta, K M

    2015-01-01

    This comprehensive and unique book is intended to cover the vast and fast-growing field of electrical and electronic materials and their engineering in accordance with modern developments.   Basic and pre-requisite information has been included for easy transition to more complex topics. Latest developments in various fields of materials and their sciences/engineering, processing and applications have been included. Latest topics like PLZT, vacuum as insulator, fiber-optics, high temperature superconductors, smart materials, ferromagnetic semiconductors etc. are covered. Illustrations and exa

  3. Ab initio electronic stopping power in materials

    International Nuclear Information System (INIS)

    Shukri, Abdullah-Atef

    2015-01-01

    The average energy loss of an ion per unit path length when it is moving through the matter is named the stopping power. The knowledge of the stopping power is essential for a variety of contemporary applications which depend on the transport of ions in matter, especially ion beam analysis techniques and ion implantation. Most noticeably, the use of proton or heavier ion beams in radiotherapy requires the knowledge of the stopping power. Whereas experimental data are readily available for elemental solids, the data are much more scarce for compounds. The linear response dielectric formalism has been widely used in the past to study the electronic stopping power. In particular, the famous pioneering calculations due to Lindhard evaluate the electronic stopping power of a free electron gas. In this thesis, we develop a fully ab initio scheme based on linear response time-dependent density functional theory to predict the impact parameter averaged quantity named the random electronic stopping power (RESP) of materials without any empirical fitting. The purpose is to be capable of predicting the outcome of experiments without any knowledge of target material besides its crystallographic structure. Our developments have been done within the open source ab initio code named ABINIT, where two approximations are now available: the Random-Phase Approximation (RPA) and the Adiabatic Local Density Approximation (ALDA). Furthermore, a new method named 'extrapolation scheme' have been introduced to overcome the stringent convergence issues we have encountered. These convergence issues have prevented the previous studies in literature from offering a direct comparison to experiment. First of all, we demonstrate the importance of describing the realistic ab initio electronic structure by comparing with the historical Lindhard stopping power evaluation. Whereas the Lindhard stopping power provides a first order description that captures the general features of the

  4. Elements including metals in the atomizer and aerosol of disposable electronic cigarettes and electronic hookahs.

    Directory of Open Access Journals (Sweden)

    Monique Williams

    Full Text Available Our purpose was to quantify 36 inorganic chemical elements in aerosols from disposable electronic cigarettes (ECs and electronic hookahs (EHs, examine the effect of puffing topography on elements in aerosols, and identify the source of the elements.Thirty-six inorganic chemical elements and their concentrations in EC/EH aerosols were determined using inductively coupled plasma optical emission spectroscopy, and their source was identified by analyzing disassembled atomizers using scanning electron microscopy and energy dispersive X-ray spectroscopy.Of 36 elements screened, 35 were detected in EC/EH aerosols, while only 15 were detected in conventional tobacco smoke. Some elements/metals were present in significantly higher concentrations in EC/EH aerosol than in cigarette smoke. Concentrations of particular elements/metals within EC/EH brands were sometimes variable. Aerosols generated at low and high air-flow rates produced the same pattern of elements, although the total element concentration decreased at the higher air flow rate. The relative amount of elements in the first and last 60 puffs was generally different. Silicon was the dominant element in aerosols from all EC/EH brands and in cigarette smoke. The elements appeared to come from the filament (nickel, chromium, thick wire (copper coated with silver, brass clamp (copper, zinc, solder joints (tin, lead, and wick and sheath (silicon, oxygen, calcium, magnesium, aluminum. Lead was identified in the solder and aerosol of two brands of EHs (up to 0.165 μg/10 puffs.These data show that EC/EH aerosols contain a mixture of elements, including heavy metals, with concentrations often significantly higher than in conventional cigarette smoke. While the health effects of inhaling mixtures of heated metals is currently not known, these data will be valuable in future risk assessments involving EC/EH elements/metals.

  5. Elements including metals in the atomizer and aerosol of disposable electronic cigarettes and electronic hookahs.

    Science.gov (United States)

    Williams, Monique; Bozhilov, Krassimir; Ghai, Sanjay; Talbot, Prue

    2017-01-01

    Our purpose was to quantify 36 inorganic chemical elements in aerosols from disposable electronic cigarettes (ECs) and electronic hookahs (EHs), examine the effect of puffing topography on elements in aerosols, and identify the source of the elements. Thirty-six inorganic chemical elements and their concentrations in EC/EH aerosols were determined using inductively coupled plasma optical emission spectroscopy, and their source was identified by analyzing disassembled atomizers using scanning electron microscopy and energy dispersive X-ray spectroscopy. Of 36 elements screened, 35 were detected in EC/EH aerosols, while only 15 were detected in conventional tobacco smoke. Some elements/metals were present in significantly higher concentrations in EC/EH aerosol than in cigarette smoke. Concentrations of particular elements/metals within EC/EH brands were sometimes variable. Aerosols generated at low and high air-flow rates produced the same pattern of elements, although the total element concentration decreased at the higher air flow rate. The relative amount of elements in the first and last 60 puffs was generally different. Silicon was the dominant element in aerosols from all EC/EH brands and in cigarette smoke. The elements appeared to come from the filament (nickel, chromium), thick wire (copper coated with silver), brass clamp (copper, zinc), solder joints (tin, lead), and wick and sheath (silicon, oxygen, calcium, magnesium, aluminum). Lead was identified in the solder and aerosol of two brands of EHs (up to 0.165 μg/10 puffs). These data show that EC/EH aerosols contain a mixture of elements, including heavy metals, with concentrations often significantly higher than in conventional cigarette smoke. While the health effects of inhaling mixtures of heated metals is currently not known, these data will be valuable in future risk assessments involving EC/EH elements/metals.

  6. The 2016 oxide electronic materials and oxide interfaces roadmap

    DEFF Research Database (Denmark)

    Lorenz, M.; Rao, M. S. Ramachandra; Venkatesan, T.

    2016-01-01

    , spintronics, thermoelectrics, piezoelectrics, power harvesting, hydrogen storage and environmental waste management. Synthesis and fabrication of these materials, as well as processing into particular device structures to suit a specific application is still a challenge. Further, characterization......Oxide electronic materials provide a plethora of possible applications and offer ample opportunity for scientists to probe into some of the exciting and intriguing phenomena exhibited by oxide systems and oxide interfaces. In addition to the already diverse spectrum of properties, the nanoscale...... form of oxides provides a new dimension of hitherto unknown phenomena due to the increased surface-to-volume ratio. Oxide electronic materials are becoming increasingly important in a wide range of applications including transparent electronics, optoelectronics, magnetoelectronics, photonics...

  7. 78 FR 34132 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-06-06

    ... INTERNATIONAL TRADE COMMISSION [Docket No 2958] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Correction to Notice of Receipt of Complaint; Solicitation... of complaint entitled Certain Portable Electronic Communications Devices, Including Mobile Phones and...

  8. 78 FR 16865 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Science.gov (United States)

    2013-03-19

    ..., Including Wireless Communication Devices, Portable Music and Data Processing Devices, and Tablet Computers... Samsung Electronics Co., Ltd. of Seoul, Republic of Korea, and Samsung Telecommunications America, LLC of... certain electronic devices, including wireless communication devices, portable music and data processing...

  9. Microwave technology for waste management applications including disposition of electronic circuitry

    International Nuclear Information System (INIS)

    Wicks, G.G.; Clark, D.E.; Schulz, R.L.; Folz, D.C.

    1995-01-01

    Microwave technology is being developed nationally and internationally for a variety of environmental remediation purposes. These efforts include treatment and destruction of a vast array of gaseous, liquid and solid hazardous wastes as well as subsequent immobilization of selected components. Microwave technology provides an important contribution to an arsenal of existing remediation methods that are designed to protect the public and environment from undesirable consequences of hazardous materials. Applications of microwave energy for environmental remediation will be discussed. Emphasized will be a newly developed microwave process designed to treat discarded electronic circuitry and reclaim the precious metals within for reuse

  10. Microwave Technology for Waste Management Applications Including Disposition of Electronic Circuitry

    International Nuclear Information System (INIS)

    Wicks, G.G.; Clark, D.E.; Schulz, R.L.

    1998-01-01

    Advanced microwave technology is being developed nationally and internationally for a variety of waste management and environmental remediation purposes. These efforts include treatment and destruction of a vast array of gaseous, liquid and solid hazardous wastes as well as subsequent immobilization of hazardous components into leach resistant forms. Microwave technology provides an important contribution to an arsenal of existing remediation methods that are designed to protect the public and environment from the undesirable consequences of hazardous materials. One application of special interest is the treatment of discarded electronic circuitry using a new hybrid microwave treatment process and subsequent reclamation of the precious metals within

  11. Transmission electron microscopy and diffractometry of materials

    CERN Document Server

    Fultz, Brent

    2001-01-01

    This book teaches graduate students the concepts of trans- mission electron microscopy (TEM) and x-ray diffractometry (XRD) that are important for the characterization of materi- als. It emphasizes themes common to both techniques, such as scattering from atoms and the formation and analysis of dif- fraction patterns. It also describes unique aspects of each technique, especially imaging and spectroscopy in the TEM. The textbook thoroughly develops both introductory and ad- vanced-level material, using over 400 accompanying illustra- tions. Problems are provided at the end of each chapter to reinforce key concepts. Simple citatioins of rules are avoi- ded as much as possible, and both practical and theoretical issues are explained in detail. The book can be used as both an introductory and advanced-level graduate text since sec- tions/chapters are sorted according to difficulty and grou- ped for use in quarter and semester courses on TEM and XRD.

  12. The 2016 oxide electronic materials and oxide interfaces roadmap

    International Nuclear Information System (INIS)

    Lorenz, M; Grundmann, M; Ramachandra Rao, M S; Mukherjee, J; Priyadarshini, M; Venkatesan, T; Fortunato, E; Barquinha, P; Branquinho, R; Salgueiro, D; Martins, R; Carlos, E; Liu, A; Shan, F K; Boschker, H; DasGupta, N; Rogers, D J; Teherani, F H; Sandana, E V; Bove, P

    2016-01-01

    Oxide electronic materials provide a plethora of possible applications and offer ample opportunity for scientists to probe into some of the exciting and intriguing phenomena exhibited by oxide systems and oxide interfaces. In addition to the already diverse spectrum of properties, the nanoscale form of oxides provides a new dimension of hitherto unknown phenomena due to the increased surface-to-volume ratio. Oxide electronic materials are becoming increasingly important in a wide range of applications including transparent electronics, optoelectronics, magnetoelectronics, photonics, spintronics, thermoelectrics, piezoelectrics, power harvesting, hydrogen storage and environmental waste management. Synthesis and fabrication of these materials, as well as processing into particular device structures to suit a specific application is still a challenge. Further, characterization of these materials to understand the tunability of their properties and the novel properties that evolve due to their nanostructured nature is another facet of the challenge. The research related to the oxide electronic field is at an impressionable stage, and this has motivated us to contribute with a roadmap on ‘oxide electronic materials and oxide interfaces’. This roadmap envisages the potential applications of oxide materials in cutting edge technologies and focuses on the necessary advances required to implement these materials, including both conventional and novel techniques for the synthesis, characterization, processing and fabrication of nanostructured oxides and oxide-based devices. The contents of this roadmap will highlight the functional and correlated properties of oxides in bulk, nano, thin film, multilayer and heterostructure forms, as well as the theoretical considerations behind both present and future applications in many technologically important areas as pointed out by Venkatesan. The contributions in this roadmap span several thematic groups which are represented by

  13. Materials Meets Concepts in Molecule-Based Electronics

    KAUST Repository

    Ortmann, Frank

    2014-10-14

    In this contribution, molecular materials are highlighted as an important topic in the diverse field of condensed matter physics, with focus on their particular electronic and transport properties. A better understanding of their performance in various applications and devices demands for an extension of basic theoretical approaches to describe charge transport in molecular materials, including the accurate description of electron-phonon coupling. Starting with the simplest case of a molecular junction and moving on to larger aggregates of bulk organic semiconductors, charge-transport regimes from ballistic motion to incoherent hopping, which are frequently encountered in molecular systems under respective conditions, are discussed. Transport features of specific materials are described through ab initio material parameters whose determination is addressed. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.

  14. Atomic-resolution transmission electron microscopy of electron beam–sensitive crystalline materials

    KAUST Repository

    Zhang, Daliang

    2018-01-18

    High-resolution imaging of electron beam-sensitive materials is one of the most difficult applications of transmission electron microscopy (TEM). The challenges are manifold, including the acquisition of images with extremely low beam doses, the time-constrained search for crystal zone axes, the precise image alignment, and the accurate determination of the defocus value. We develop a suite of methods to fulfill these requirements and acquire atomic-resolution TEM images of several metal organic frameworks that are generally recognized as highly sensitive to electron beams. The high image resolution allows us to identify individual metal atomic columns, various types of surface termination, and benzene rings in the organic linkers. We also apply our methods to other electron beam–sensitive materials, including the organic-inorganic hybrid perovskite CH3NH3PbBr3.

  15. Atomic-resolution transmission electron microscopy of electron beam–sensitive crystalline materials

    Science.gov (United States)

    Zhang, Daliang; Zhu, Yihan; Liu, Lingmei; Ying, Xiangrong; Hsiung, Chia-En; Sougrat, Rachid; Li, Kun; Han, Yu

    2018-02-01

    High-resolution imaging of electron beam–sensitive materials is one of the most difficult applications of transmission electron microscopy (TEM). The challenges are manifold, including the acquisition of images with extremely low beam doses, the time-constrained search for crystal zone axes, the precise image alignment, and the accurate determination of the defocus value. We develop a suite of methods to fulfill these requirements and acquire atomic-resolution TEM images of several metal organic frameworks that are generally recognized as highly sensitive to electron beams. The high image resolution allows us to identify individual metal atomic columns, various types of surface termination, and benzene rings in the organic linkers. We also apply our methods to other electron beam–sensitive materials, including the organic-inorganic hybrid perovskite CH3NH3PbBr3.

  16. Sustainable Materials Management (SMM) Electronics Challenge

    Science.gov (United States)

    Learn how the SMM Electronics Challenge encourage electronic manufacturers to strive to send 100 percent of the used electronics they collect from the public and retailers to certified electronics refurbishers and recyclers.

  17. Challenges for INAA in studies of materials from advanced material research including rare earth concentrates and carbon based ceramics

    International Nuclear Information System (INIS)

    Bode, P.; Van Meerten, Th.G.

    2000-01-01

    Rare-earth elements are increasingly applied in advanced materials to be used, e.g., in electronic industry, automobile catalysts, or lamps and optical devices. Trace element analysis of these materials might be an interesting niche for NAA because of the intrinsic high accuracy of this technique, and the shortage of matrix matching reference materials with other methods for elemental analysis. The carbon composite materials form another category of advanced materials, where sometimes a very high degree of purity is required. Also for these materials, NAA has favorable analytical characteristics. Examples are given of the use of NAA in the analysis of both categories of materials. (author)

  18. Ordered materials for organic electronics and photonics.

    Science.gov (United States)

    O'Neill, Mary; Kelly, Stephen M

    2011-02-01

    We present a critical review of semiconducting/light emitting, liquid crystalline materials and their use in electronic and photonic devices such as transistors, photovoltaics, OLEDs and lasers. We report that annealing from the mesophase improves the order and packing of organic semiconductors to produce state-of-the-art transistors. We discuss theoretical models which predict how charge transport and light emission is affected by the liquid crystalline phase. Organic photovoltaics and OLEDs require optimization of both charge transport and optical properties and we identify the various trade-offs involved for ordered materials. We report the crosslinking of reactive mesogens to give pixellated full-colour OLEDs and distributed bi-layer photovoltaics. We show how the molecular organization inherent to the mesophase can control the polarization of light-emitting devices and the gain in organic, thin-film lasers and can also provide distributed feedback in chiral nematic mirrorless lasers. We update progress on the surface alignment of liquid crystalline semiconductors to obtain monodomain devices without defects or devices with spatially varying properties. Finally the significance of all of these developments is assessed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Advances in superconducting materials and electronics technologies

    International Nuclear Information System (INIS)

    Palmer, D.N.

    1990-01-01

    Technological barriers blocking the early implementation of ceramic oxide high critical temperature [Tc] and LHe Nb based superconductors are slowly being dismantled. Spearheading these advances are mechanical engineers with diverse specialties and creative interests. As the technology expands, most engineers have recognized the importance of inter-disciplinary cooperation. Cooperation between mechanical engineers and material and system engineers is of particular importance. Recently, several problems previously though to be insurmountable, has been successfully resolved. These accomplishment were aided by interaction with other scientists and practitioners, working in the superconductor research and industrial communities, struggling with similar systems and materials problems. Papers published here and presented at the 1990 ASME Winter Annual Meeting held in Dallas, Texas 25-30 November 1990 can be used as a bellwether to gauge the progress in the development of both ceramic oxide and low temperature Nb superconducting device and system technologies. Topics are focused into two areas: mechanical behavior of high temperature superconductors and thermal and mechanical problems in superconducting electronics

  20. Oxide bipolar electronics: materials, devices and circuits

    Science.gov (United States)

    Grundmann, Marius; Klüpfel, Fabian; Karsthof, Robert; Schlupp, Peter; Schein, Friedrich-Leonhard; Splith, Daniel; Yang, Chang; Bitter, Sofie; von Wenckstern, Holger

    2016-06-01

    We present the history of, and the latest progress in, the field of bipolar oxide thin film devices. As such we consider primarily pn-junctions in which at least one of the materials is a metal oxide semiconductor. A wide range of n-type and p-type oxides has been explored for the formation of such bipolar diodes. Since most oxide semiconductors are unipolar, challenges and opportunities exist with regard to the formation of heterojunction diodes and band lineups. Recently, various approaches have led to devices with high rectification, namely p-type ZnCo2O4 and NiO on n-type ZnO and amorphous zinc-tin-oxide. Subsequent bipolar devices and applications such as photodetectors, solar cells, junction field-effect transistors and integrated circuits like inverters and ring oscillators are discussed. The tremendous progress shows that bipolar oxide electronics has evolved from the exploration of various materials and heterostructures to the demonstration of functioning integrated circuits. Therefore a viable, facile and high performance technology is ready for further exploitation and performance optimization.

  1. Secondary electron interactions in materials with environmental and radiological interest

    International Nuclear Information System (INIS)

    Garcia, G.; Blanco, F.; Pablos, J.L. de; Perez, J.M.; Williart, A.

    2003-01-01

    Important environmental and radiological applications require energy deposition models including the interactions between secondary electrons and the atoms or molecules of the medium. In this work we propose a method to obtain reliable cross-section data to be used in these models by combining total and ionization cross-section measurements with simple calculations of the differential and integral elastic cross-sections. The energy loss spectra obtained in this experiment have been also used to drive stopping power of the considered materials for electrons. Some examples of results for atomic (Xe) and molecular (CF 4 ) targets are presented and discussed in this paper. (author)

  2. 78 FR 48468 - Delphi Corporation, Electronics and Safety Division, Including On-Site Leased Workers From...

    Science.gov (United States)

    2013-08-08

    ..., Electronics and Safety Division, Including On-Site Leased Workers From Securitas, Bartech, Flint Janitorial... Adjustment Assistance on May 20, 2013, applicable to workers of Delphi Corporation, Electronics and Safety... on- site at the Flint, Michigan location of Delphi Corporation, Electronics and Safety Division. The...

  3. Nanocellulose as Material Building Block for Energy and Flexible Electronics

    Science.gov (United States)

    Hu, Liangbing

    2014-03-01

    In this talk, I will discuss the fabrications, properties and device applications of functional nanostructured paper based on nanocellulose. Nanostructures with tunable optical, electrical, ionic and mechanical properties will be discussed. Lab-scale demonstration devices, including low-cost Na-ion batteries, microbial fuel cells, solar cells, transparent transistors, actuators and touch screens will be briefly mentioned. These studies show that nanocellulose is a promising green material for electronics and energy devices.

  4. Generation of complete electronic nuclear medicine reports including static, dynamic and gated images

    International Nuclear Information System (INIS)

    Beretta, M.; Pilon, R.; Mut, F.

    2002-01-01

    Aim: To develop a procedure for the creation of nuclear medicine reports containing static and dynamic images. The reason for implementing this technique is the lack of adequate solutions for an electronic format of nuclear medicine results allowing for rapid transmission via e-mail, specially in the case of dynamic and gated SPECT studies, since functional data is best presented in dynamic mode. Material and Methods: Clinical images were acquired in static, whole body, dynamic and gated mode, corresponding to bone studies, diuretic renogram, radionuclide cystography and gated perfusion SPECT, as well as respective time-activity curves. Image files were imported from a dedicated nuclear medicine computer system (Elscint XPert) to a Windows-based PC through a standard ethernet network with TCP-IP communications protocol, using a software developed by us which permits the conversion from the manufacturer's original format into a bitmap format (.bmp) compatible with commercially available PC software. For cardiac perfusion studies, background was subtracted prior to transferring to reduce the amount of information in the file; this was not done for other type of studies because useful data could be eliminated. Dynamic images were then processed using commercial software to create animated files and stored in .gif format. Static images were re-sized and stored in .jpg format. Original color or gray scale was always preserved. All the graphic material was then merged with a previously prepared report text using HTML format. The report also contained reference diagrams to facilitate interpretation. The whole report was then compressed into a self-extractable file, ready to be sent by electronic mail. Reception of the material was visually checked for data integrity including image quality by two experienced nuclear medicine physicians. Results: The report presented allows for simultaneous visualization of the text, diagrams and images either static, dynamic, gated or

  5. Sustainable Materials Management (SMM) Electronics Challenge Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — On September 22, 2012, EPA launched the SMM Electronics Challenge. The Challenge encourages electronics manufacturers, brand owners and retailers to strive to send...

  6. Electron Microscopy and Image Analysis for Selected Materials

    Science.gov (United States)

    Williams, George

    1999-01-01

    This particular project was completed in collaboration with the metallurgical diagnostics facility. The objective of this research had four major components. First, we required training in the operation of the environmental scanning electron microscope (ESEM) for imaging of selected materials including biological specimens. The types of materials range from cyanobacteria and diatoms to cloth, metals, sand, composites and other materials. Second, to obtain training in surface elemental analysis technology using energy dispersive x-ray (EDX) analysis, and in the preparation of x-ray maps of these same materials. Third, to provide training for the staff of the metallurgical diagnostics and failure analysis team in the area of image processing and image analysis technology using NIH Image software. Finally, we were to assist in the sample preparation, observing, imaging, and elemental analysis for Mr. Richard Hoover, one of NASA MSFC's solar physicists and Marshall's principal scientist for the agency-wide virtual Astrobiology Institute. These materials have been collected from various places around the world including the Fox Tunnel in Alaska, Siberia, Antarctica, ice core samples from near Lake Vostoc, thermal vents in the ocean floor, hot springs and many others. We were successful in our efforts to obtain high quality, high resolution images of various materials including selected biological ones. Surface analyses (EDX) and x-ray maps were easily prepared with this technology. We also discovered and used some applications for NIH Image software in the metallurgical diagnostics facility.

  7. Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials

    Directory of Open Access Journals (Sweden)

    Efstratia N. Sgourou

    2017-06-01

    Full Text Available The technological requirement to optimize materials for energy and electronic materials has led to the use of defect engineering strategies. These strategies take advantage of the impact of composition, disorder, structure, and mechanical strain on the material properties. In the present review, we highlight key strategies presently employed or considered to tune the properties of energy and electronic materials. We consider examples from electronic materials (silicon and germanium, photocatalysis (titanium oxide, solid oxide fuel cells (cerium oxide, and nuclear materials (nanocomposites.

  8. High-resolution electron microscopy of advanced materials

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  9. Advanced materials for thermal management of electronic packaging

    CERN Document Server

    Tong, Xingcun Colin

    2011-01-01

    The need for advanced thermal management materials in electronic packaging has been widely recognized as thermal challenges become barriers to the electronic industry's ability to provide continued improvements in device and system performance. With increased performance requirements for smaller, more capable, and more efficient electronic power devices, systems ranging from active electronically scanned radar arrays to web servers all require components that can dissipate heat efficiently. This requires that the materials have high capability of dissipating heat and maintaining compatibility

  10. Reversible Hydrogen Storage Materials – Structure, Chemistry, and Electronic Structure

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ian M. [University of Wisconsin-Madison; Johnson, Duane D. [Ames Lab., Iowa

    2014-06-21

    To understand the processes involved in the uptake and release of hydrogen from candidate light-weight metal hydride storage systems, a combination of materials characterization techniques and first principle calculation methods have been employed. In addition to conventional microstructural characterization in the transmission electron microscope, which provides projected information about the through thickness microstructure, electron tomography methods were employed to determine the three-dimensional spatial distribution of catalyst species for select systems both before and after dehydrogenation. Catalyst species identification as well as compositional analysis of the storage material before and after hydrogen charging and discharging was performed using a combination of energy dispersive spectroscopy, EDS, and electron energy loss spectroscopy, EELS. The characterization effort was coupled with first-principles, electronic-structure and thermodynamic techniques to predict and assess meta-stable and stable phases, reaction pathways, and thermodynamic and kinetic barriers. Systems studied included:NaAlH4, CaH2/CaB6 and Ca(BH4)2, MgH2/MgB2, Ni-Catalyzed Magnesium Hydride, TiH2-Catalyzed Magnesium Hydride, LiBH4, Aluminum-based systems and Aluminum

  11. Electron Beam Adjustment in PLATO RTS 2 Including the Effect of Air Gaps

    CERN Document Server

    Lopes, M C; Trindade, A; Rodrigues, P; Peralta, L

    2002-01-01

    Background and Purpose: Beam characterization for electron dose calculations in PLATO RTS 2 treatment planning system requires the tuning of two adjustment parameters: sqx (the initial angular spread) and FMCS (a "fudge" multiple Coulomb scattering parameter). This work provides a set of suggestions to optimise electron dose calculations with PLATO, taking into account the effect of air gaps between the electron applicator and the patient skin. Material and Methods: Two adjustment criteria have been followed: one which uses just one input data set corresponding to the standard (null) air gap and another one that takes into account the whole range of clinically used distances between the electron applicator and the patient surface. The adjusted values of sqx were compared with experimental data and GEANT3 Monte Carlo code results. A systematic study has been carried out of the effect of both adjustment parameters on electron dose calculations in water. Comparisons of dose distributions and point dose values ha...

  12. Electronic Structure of Complex Materials: from First-principles study ...

    Indian Academy of Sciences (India)

    Electronic Structure of Complex Materials: from. First-principles study to Materials Modeling. Tanusri Saha-Dasgupta. Dept. of Materials Science & Advanced Materials. Research Unit. S.N. Bose National Centre for Basic Sciences. Salt Lake, Calcutta, INDIA http://www.bose.res.in/∼tanusri/ . – p.1/25 ...

  13. 78 FR 56737 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-09-13

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review an Initial Determination Granting Complainant's Motion To Amend the Complaint and Notice of Investigation...

  14. 78 FR 34669 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Science.gov (United States)

    2013-06-10

    ..., Including Wireless Communication Devices, Portable Music and Data Processing Devices, and Tablet Computers... importing wireless communication devices, portable music and data processing devices, and tablet computers... filed by Samsung Electronics Co., Ltd. of Korea and Samsung Telecommunications America, LLC of...

  15. 77 FR 60720 - Certain Electronic Devices, Including Wireless Commmunication Devices, Portable Music and Data...

    Science.gov (United States)

    2012-10-04

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-794] Certain Electronic Devices, Including Wireless Commmunication Devices, Portable Music and Data Processing Devices, and Tablet Computers... communication devices, portable music and data processing devices, and tablet computers, imported by Apple Inc...

  16. Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

    Science.gov (United States)

    Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

    2013-01-22

    Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

  17. Amorphous electron-accepting materials for organic optoelectronics

    NARCIS (Netherlands)

    Ganesan, P.

    2007-01-01

    The importance of organic materials for use in electronic devices such as OLEDs, OFETs and photovoltaic cells has increased significantly over the past decade. Organic materials have been attractive candidates for such electronic devices because of their compatibility with high-throughput, low-cost

  18. Electron emission from materials at low excitation energies

    International Nuclear Information System (INIS)

    Urma, N.; Kijek, M.; Millar, J.J.

    1996-01-01

    Full text: An experimental system has been designed and developed with the purpose of measuring the total electron emission yield from materials at low energy excitation. In the first instance the reliability of the system was checked by measuring the total electron emission yield for a well defined surface (aluminium 99.45%). The obtained data was in the expected range given by the literature, and consequently the system will be used further for measuring the total electron yield for a range of materials with interest in the instrumentation industry. We intend to measure the total electron emission yield under electron bombardment as a function of incident electron energy up to 1200 eV, angle of incidence, state of the surface and environment to which the surface has been exposed. Dependence of emission on total electron irradiated dose is also of interest. For many practical application of the 'Secondary Electron Emission', the total electron yield is desired to be as large as possible. The above phenomenon has practical applicability in electron multiplier tube and Scanning electron microscopy - when by means of the variation of the yield of the emitted electrons one may produce visible images of small sample areas. The electron multiplier tube, is a device which utilises the above effect to detect and amplify both single particles and low currents streams of charged particles. The majority of electron tubes use electrons with low energy, hundreds of eV. Not a lot has been published in the literature about this regime and also about the emission when the impinging electrons have small energy, up to 1 KeV. The information obtained from the experimental measurements concerning the total electron emission yield is used to asses the investigated materials as a potential electron emitting surfaces or dynodes in an electron multiplier tube

  19. Quantitative Electron Tomography for Nanostructured Materials

    NARCIS (Netherlands)

    Friedrich, H.

    2009-01-01

    The controlled assembly of materials on the nanoscale has been a major focus of research across many scientific disciplines. In the nanometer size range, materials characteristics can be tuned not only by composition but more importantly by size and shape of constituent phases, giving rise to

  20. Scanning electron microscopy of semiconductor materials

    International Nuclear Information System (INIS)

    Bresse, J.F.; Dupuy, M.

    1978-01-01

    The use of scanning electron microscopy in semiconductors opens up a large field of use. The operating modes lending themselves to the study of semiconductors are the induced current, cathodoluminescence and the use of the potential contrast which can also be applied very effectively to the study of the devices (planar in particular). However, a thorough knowledge of the mechanisms of the penetration of electrons, generation and recombination of generated carriers in a semiconductor is necessary in order to attain a better understanding of the operating modes peculiar to semiconductors [fr

  1. Advanced transmission electron microscopy on nanostructured magnetic materials

    OpenAIRE

    Campanini, Marco

    2015-01-01

    This doctoral work is focused on the study of nanostructured magnetic materials by advanced transmission electron microscopy (TEM) techniques, with emphasis on Ni2MnGa shape memory alloy thin films and magnetite nanoparticles for biomedical applications. The combination of high-resolution transmission electron microscopy and electron diffraction to characterize morphology and crystalline structure, with Lorentz microscopy and Electron Holography, permits to achieve a deep insight in the s...

  2. Electron beam recrystallization of amorphous semiconductor materials

    Science.gov (United States)

    Evans, J. C., Jr.

    1968-01-01

    Nucleation and growth of crystalline films of silicon, germanium, and cadmium sulfide on substrates of plastic and glass were investigated. Amorphous films of germanium, silicon, and cadmium sulfide on amorphous substrates of glass and plastic were converted to the crystalline condition by electron bombardment.

  3. Material damage in graphite by run-away electrons

    Energy Technology Data Exchange (ETDEWEB)

    Hoven, H.; Koizlik, K.; Linke, J.; Nickel, H.; Wallura, E.; Kohlhaas, W.

    1989-04-01

    Graphite limiters in the KFA tokamak TEXTOR have been hit by run-away electrons, which ''burned'' craters into the material surface. The craters have been formed by material erosion and/or sublimation and by chipping of thin laminates from the surface and additionally by redeposition of graphitic material. Moreover, thin metallic layers have been detected which may have been redeposited independently from the run-away electron event, and which could be found also outside the run-away electron crater. The redeposited carbon showed primarily two types of structure, namely oriented pyrocarbon and carbon-black-like material. The crater has been investigated by metallography, optical microscopy, secondary electron microscopy combined with energy-dispersive X-ray analysis, and automatic quantitative image analysis. The examined parameters are crater geometry, cracking behaviour and type and structure of redeposited material. (orig.).

  4. Electron holography of Fe-based nanocrystalline magnetic materials (invited)

    International Nuclear Information System (INIS)

    Shindo, Daisuke; Park, Young-Gil; Gao, Youhui; Park, Hyun Soon

    2004-01-01

    Magnetic domain structures of nanocrystalline magnetic materials were extensively investigated by electron holography with a change in temperature or magnetic field applied. In both soft and hard magnetic materials, the distribution of lines of magnetic flux clarified in situ by electron holography was found to correspond well to their magnetic properties. An attempt to produce a strong magnetic field using a sharp needle made of a permanent magnet, whose movement is controlled by piezo drives has been presented. This article demonstrates that the attempt is promising to investigate the magnetization process of hard magnetic materials by electron holography

  5. Holmium hafnate: An emerging electronic device material

    Energy Technology Data Exchange (ETDEWEB)

    Pavunny, Shojan P., E-mail: shojanpp@gmail.com, E-mail: rkatiyar@hpcf.upr.edu; Sharma, Yogesh; Kooriyattil, Sudheendran; Dugu, Sita; Katiyar, Rajesh K.; Katiyar, Ram S., E-mail: shojanpp@gmail.com, E-mail: rkatiyar@hpcf.upr.edu [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States); Scott, James F. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States); Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE (United Kingdom)

    2015-03-16

    We report structural, optical, charge transport, and temperature properties as well as the frequency dependence of the dielectric constant of Ho{sub 2}Hf{sub 2}O{sub 7} (HHO) which make this material desirable as an alternative high-k dielectric for future silicon technology devices. A high dielectric constant of ∼20 and very low dielectric loss of ∼0.1% are temperature and voltage independent at 100 kHz near ambient conditions. The Pt/HHO/Pt capacitor exhibits exceptionally low Schottky emission-based leakage currents. In combination with the large observed bandgap E{sub g} of 5.6 eV, determined by diffuse reflectance spectroscopy, our results reveal fundamental physics and materials science of the HHO metal oxide and its potential application as a high-k dielectric for the next generation of complementary metal-oxide-semiconductor devices.

  6. Systems and Methods for Fabricating Structures Including Metallic Glass-Based Materials Using Low Pressure Casting

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Kennett, Andrew (Inventor)

    2018-01-01

    Systems and methods to fabricate objects including metallic glass-based materials using low-pressure casting techniques are described. In one embodiment, a method of fabricating an object that includes a metallic glass-based material includes: introducing molten alloy into a mold cavity defined by a mold using a low enough pressure such that the molten alloy does not conform to features of the mold cavity that are smaller than 100 microns; and cooling the molten alloy such that it solidifies, the solid including a metallic glass-based material.

  7. In situ and operando transmission electron microscopy of catalytic materials

    DEFF Research Database (Denmark)

    Crozier, Peter A.; Hansen, Thomas Willum

    2015-01-01

    Catalytic nanomaterials play a major role in chemical conversions and energy transformations. Understanding how materials control and regulate surface reactions is a major objective for fundamental research on heterogeneous catalysts. In situ environmental transmission electron microscopy (ETEM...

  8. Electronic processes in non-crystalline materials

    CERN Document Server

    Mott, Nevill Francis

    2012-01-01

    Since the first edition of this highly successful book the field saw many great developments both in experimental and theoretical studies of electrical properties of non-crystalline solids. It became necessary to rewrite nearly the whole book, while the aims of the second edition remained the same: to set out the theoretical concepts, to test them by comparison with experiment for a wide variety of phenomena, and to apply them to non-crystalline materials. Sir Nevill Mott shared the1977 Nobel Prize for Physics, awarded for his research work in this field. The reissue of this book as part of th

  9. Epitaxial graphene: the material for graphene electronics

    Energy Technology Data Exchange (ETDEWEB)

    Sprinkle, M.; Soukiassian, P.; de Heer, W.A.; Berger, C.; Conrad, E.H.; (CEA); (GIT)

    2009-12-10

    The search for an ideal graphene sheet has been a quest driving graphene research. While most research has focused on exfoliated graphene, intrinsic substrate interactions and mechanical disorder have precluded the observation of a number of graphene's expected physical properties in this material. The only graphene candidate that has demonstrated all the essential properties of an ideal sheet is multilayer graphene grown on the SiC(000) surface. Its unique stacking allows nearly all the sheets in the stack to behave like isolated graphene, while the weak graphene-graphene interaction prevents any significant doping or distortion in the band near the Fermi level.

  10. 78 FR 49764 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-08-15

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review n Initial Determination Granting Google, Inc.'s Unopposed Motion To Intervene AGENCY: U.S. International...

  11. 78 FR 72712 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-12-03

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review an Initial Determination Granting Google, Inc.'s Motion To Intervene AGENCY: U.S. International Trade...

  12. 77 FR 70464 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Science.gov (United States)

    2012-11-26

    ..., Including Wireless Communication Devices, Portable Music and Data Processing Devices, and Tablet Computers... Samsung Electronics Co., Ltd. of Korea and Samsung Telecommunications America, LLC of Richardson, Texas... wireless communication devices, portable music and data processing devices, and tablet computers, by reason...

  13. 77 FR 34063 - Certain Electronic Devices, Including Mobile Phones and Tablet Computers, and Components Thereof...

    Science.gov (United States)

    2012-06-08

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-847] Certain Electronic Devices, Including Mobile.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on May 2, 2012, under section 337 of the Tariff Act of 1930...

  14. 75 FR 10502 - In the Matter of Certain Electronic Devices, Including Handheld Wireless Communications Devices...

    Science.gov (United States)

    2010-03-08

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-667; Investigation No. 337-TA-673] In the Matter of Certain Electronic Devices, Including Handheld Wireless Communications Devices; Notice of... Entirety AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that...

  15. 75 FR 448 - In the Matter of: Certain Authentication Systems, Including Software and Handheld Electronic...

    Science.gov (United States)

    2010-01-05

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-697] In the Matter of: Certain Authentication Systems, Including Software and Handheld Electronic Devices; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION: Institution of investigation pursuant to 19 U.S.C. 1337. SUMMARY: Notice...

  16. 77 FR 27078 - Certain Electronic Devices, Including Mobile Phones and Tablet Computers, and Components Thereof...

    Science.gov (United States)

    2012-05-08

    ... INTERNATIONAL TRADE COMMISSION [Docket No. 2896] Certain Electronic Devices, Including Mobile... Comments Relating to the Public Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint...

  17. 78 FR 1247 - Certain Electronic Devices, Including Wireless Communication Devices, Tablet Computers, Media...

    Science.gov (United States)

    2013-01-08

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-862] Certain Electronic Devices, Including...; Institution of Investigation Pursuant to United States Code AGENCY: U.S. International Trade Commission... Trade Commission on November 30, 2012, under section 337 of the Tariff Act of 1930, as amended, 19 U.S.C...

  18. 78 FR 63492 - Certain Electronic Devices, Including Mobile Phones and Tablet Computers, and Components Thereof...

    Science.gov (United States)

    2013-10-24

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-847] Certain Electronic Devices, Including Mobile Phones and Tablet Computers, and Components Thereof; Notice of Request for Statements on the Public Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is...

  19. Quantifying Nanoscale Order in Amorphous Materials via Fluctuation Electron Microscopy

    Science.gov (United States)

    Bogle, Stephanie Nicole

    2009-01-01

    Fluctuation electron microscopy (FEM) has been used to study the nanoscale order in various amorphous materials. The method is explicitly sensitive to 3- and 4-body atomic correlation functions in amorphous materials; this is sufficient to establish the existence of structural order on the nanoscale, even when the radial distribution function…

  20. Nanodiamond composite as a material for cold electron emitters

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, A V; Sominski, G G; Uvarov, A A [St.Petersburg State Polytechnic University, 29 Politchnicheskaya, St.Petersburg, 195251 (Russian Federation); Gordeev, S K; Korchagina, S B [FSUE ' Central Research Institute for Materials' , 8 Paradnaya Street, St.Petersburg, 191014 (Russian Federation)], E-mail: arkhipov@rphf.spbstu.ru

    2008-03-15

    Characteristics of field-induced electron emission were investigated for one of newly designed all-carbon materials - nanodiamond composite (NDC). The composite is comprised by 4-6 nm diamond grains covered with 0.2-1 nm-thick graphite-like shells that merge at grain junctions and determine such properties as mechanical strength and high electric conductivity. Large number of uniformly distributed sp{sup 3}-sp{sup 2} interfaces allowed to expect enhanced electron emission in electric field. Combination of these features makes NDC a promising material for cold electron emitters in various applications. Experimental testing confirmed high efficiency of electron emission from NDC. In comparison with previousely tested forms of nanocarbon, NDC emitters demonstrated better stabily and tolerance to performance conditions. Unusual activation scenarios and thermal dependencies of emission characteristics observed in experiments with NDC can add new background for explanation of facilitated electron emission from nanocarbons with relatively 'smooth' surface morphology.

  1. Contained scanning electron microscope facility for examining radioactive materials

    International Nuclear Information System (INIS)

    Hsu, C.W.

    1986-03-01

    At the Savannah River Laboratory (SRL) radioactive solids are characterized with a scanning electron microscope (SEM) contained in a glove box. The system includes a research-grade Cambridge S-250 SEM, a Tracor Northern TN-5500 x-ray and image analyzer, and a Microspec wavelength-dispersive x-ray analyzer. The containment facility has a glove box train for mounting and coating samples, and for housing the SEM column, x-ray detectors, and vacuum pumps. The control consoles of the instruments are located outside the glove boxes. This facility has been actively used since October 1983 for high alpha-activity materials such as plutonium metal and plutonium oxide powders. Radioactive defense waste glasses and contaminated equipment have also been examined. During this period the facility had no safety-related incidents, and personnel radiation exposures were maintained at less than 100 mrems

  2. Vibrationally resolved electronic spectra including vibrational pre-excitation: Theory and application to VIPER spectroscopy

    Science.gov (United States)

    von Cosel, Jan; Cerezo, Javier; Kern-Michler, Daniela; Neumann, Carsten; van Wilderen, Luuk J. G. W.; Bredenbeck, Jens; Santoro, Fabrizio; Burghardt, Irene

    2017-10-01

    Vibrationally resolved electronic absorption spectra including the effect of vibrational pre-excitation are computed in order to interpret and predict vibronic transitions that are probed in the Vibrationally Promoted Electronic Resonance (VIPER) experiment [L. J. G. W. van Wilderen et al., Angew. Chem., Int. Ed. 53, 2667 (2014)]. To this end, we employ time-independent and time-dependent methods based on the evaluation of Franck-Condon overlap integrals and Fourier transformation of time-domain wavepacket autocorrelation functions, respectively. The time-independent approach uses a generalized version of the FCclasses method [F. Santoro et al., J. Chem. Phys. 126, 084509 (2007)]. In the time-dependent approach, autocorrelation functions are obtained by wavepacket propagation and by the evaluation of analytic expressions, within the harmonic approximation including Duschinsky rotation effects. For several medium-sized polyatomic systems, it is shown that selective pre-excitation of particular vibrational modes leads to a redshift of the low-frequency edge of the electronic absorption spectrum, which is a prerequisite for the VIPER experiment. This effect is typically most pronounced upon excitation of modes that are significantly displaced during the electronic transition, such as ring distortion modes within an aromatic π-system. Theoretical predictions as to which modes show the strongest VIPER effect are found to be in excellent agreement with experiment.

  3. Student decisions about lecture attendance: do electronic course materials matter?

    Science.gov (United States)

    Billings-Gagliardi, Susan; Mazor, Kathleen M

    2007-10-01

    This study explored whether first-year medical students make deliberate decisions about attending nonrequired lectures. If so, it sought to identify factors that influence these decisions, specifically addressing the potential impact of electronic materials. Medical students who completed first-year studies between 2004 and 2006 responded to an open-ended survey question about their own lecture-attendance decisions. Responses were coded to capture major themes. Students' ratings of the electronic materials were also examined. Most respondents made deliberate attendance decisions. Decisions were influenced by previous experiences with the lecturer, predictions of what would occur during the session itself, personal learning preferences, and learning needs at that particular time, with the overriding goal of maximizing learning. Access to electronic materials did not influence students' choices. Fears that the increasing availability of technology-enhanced educational materials has a negative impact on lecture attendance seem unfounded.

  4. Dissolution chemistry and biocompatibility of single-crystalline silicon nanomembranes and associated materials for transient electronics.

    Science.gov (United States)

    Hwang, Suk-Won; Park, Gayoung; Edwards, Chris; Corbin, Elise A; Kang, Seung-Kyun; Cheng, Huanyu; Song, Jun-Kyul; Kim, Jae-Hwan; Yu, Sooyoun; Ng, Joanne; Lee, Jung Eun; Kim, Jiyoung; Yee, Cassian; Bhaduri, Basanta; Su, Yewang; Omennetto, Fiorenzo G; Huang, Yonggang; Bashir, Rashid; Goddard, Lynford; Popescu, Gabriel; Lee, Kyung-Mi; Rogers, John A

    2014-06-24

    Single-crystalline silicon nanomembranes (Si NMs) represent a critically important class of material for high-performance forms of electronics that are capable of complete, controlled dissolution when immersed in water and/or biofluids, sometimes referred to as a type of "transient" electronics. The results reported here include the kinetics of hydrolysis of Si NMs in biofluids and various aqueous solutions through a range of relevant pH values, ionic concentrations and temperatures, and dependence on dopant types and concentrations. In vitro and in vivo investigations of Si NMs and other transient electronic materials demonstrate biocompatibility and bioresorption, thereby suggesting potential for envisioned applications in active, biodegradable electronic implants.

  5. Materials Cartography: Representing and Mining Material Space Using Structural and Electronic Fingerprints

    Science.gov (United States)

    Oses, Corey; Isayev, Olexandr; Fourches, Denis; Muratov, Eugene; Rasch, Kevin; Tropsha, Alexander; Curtarolo, Stefano; CenterMaterials Genomics, Duke University Collaboration; LaboratoryMolecular Modeling, UNC Chapel Hill Collaboration

    2015-03-01

    As the proliferation of high-throughput approaches in materials science is increasing the wealth of data in the field, the gap between accumulated-information and derived-knowledge widens. We address the issue of scientific discovery in materials databases by introducing novel analytical approaches based on structural and electronic materials fingerprints. The framework is employed to (i) query large databases of materials using similarity concepts, (ii) map the connectivity of the materials space (i.e., as a materials cartogram) for rapidly identifying regions with unique organizations/properties, and (iii) develop predictive Quantitative Materials Structure-Property Relationships (QMSPR) models for guiding materials design. In this study, we test these fingerprints by seeking target material properties. As a quantitative example, we model the critical temperatures of known superconductors. Our novel materials fingerprinting and materials cartography approaches contribute to the emerging field of materials informatics by enabling effective computational tools to analyze, visualize, model, and design new materials.

  6. 76 FR 31983 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and...

    Science.gov (United States)

    2011-06-02

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-701] In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and Computers; Notice of Commission... States after importation of certain electronic devices, including mobile phones, portable music players...

  7. Introduction to organic electronic and optoelectronic materials and devices

    CERN Document Server

    Sun, Sam-Shajing

    2008-01-01

    Introduction to Optoelectronic Materials, N. Peyghambarian and M. Fallahi Introduction to Optoelectronic Device Principles, J. Piprek Basic Electronic Structures and Charge Carrier Generation in Organic Optoelectronic Materials, S.-S. Sun Charge Transport in Conducting Polymers, V.N. Prigodin and A.J. Epstein Major Classes of Organic Small Molecules for Electronic and Optoelectronics, X. Meng, W. Zhu, and H. Tian Major Classes of Conjugated Polymers and Synthetic Strategies, Y. Li and J. Hou Low Energy Gap, Conducting, and Transparent Polymers, A. Kumar, Y. Ner, and G.A. Sotzing Conjugated Polymers, Fullerene C60, and Carbon Nanotubes for Optoelectronic Devices, L. Qu, L. Dai, and S.-S. Sun Introduction of Organic Superconducting Materials, H. Mori Molecular Semiconductors for Organic Field-Effect Transistors, A. Facchetti Polymer Field-Effect Transistors, H.G.O. Sandberg Organic Molecular Light-Emitting Materials and Devices, F. So and J. Shi Polymer Light-Emitting Diodes: Devices and Materials, X. Gong and ...

  8. Complex influence of factors of a Space on materials and devices of electronics in the microgravity

    Science.gov (United States)

    Grichshenko, Valentina; Zhantayev, Zhumabek

    In work the new physical model of the processes occurring in materials and devices of electronics by influence of the Cosmic Rays in the conditions of the microgravity is presented. The model describes features of formation of the area of radiation defects (ARD) in electronics materials in the conditions of the microgravity. The mechanism of interaction of ARD with the memory in microgravity conditions reduce to failures of the onboard is considered. Results of failures of memory in Space will be included.

  9. Hybrid (Vlasov-Fluid) simulation of ion-acoustic solitons chain formation including trapped electrons

    Energy Technology Data Exchange (ETDEWEB)

    Behjat, E.; Aminmansoor, F.; Abbasi, H. [Faculty of Energy Engineering and Physics, Amirkabir University of Technology, P. O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

    2015-08-15

    Disintegration of a Gaussian profile into ion-acoustic solitons in the presence of trapped electrons [H. Hakimi Pajouh and H. Abbasi, Phys. Plasmas 15, 082105 (2008)] is revisited. Through a hybrid (Vlasov-Fluid) model, the restrictions associated with the simple modified Korteweg de-Vries (mKdV) model are studied. For instance, the lack of vital information in the phase space associated with the evolution of electron velocity distribution, the perturbative nature of mKdV model which limits it to the weak nonlinear cases, and the special spatio-temporal scaling based on which the mKdV is derived. Remarkable differences between the results of the two models lead us to conclude that the mKdV model can only monitor the general aspects of the dynamics, and the precise picture including the correct spatio-temporal scales and the properties of solitons should be studied within the framework of hybrid model.

  10. STIR: Novel Electronic States by Gating Strongly Correlated Materials

    Science.gov (United States)

    2016-03-01

    TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 15...REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO 8. PERFORMING ORGANIZATION REPORT NUMBER...channel limits induced electron density changes to approximately 1013 cm-2. This is sufficient to gate semiconducting materials, where the electronic

  11. Electronic and Ionic Conductors from Ordered Microporous Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dincă, Mircea [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-10-30

    The proposed work aimed to establish metal-organic frameworks (MOFs) as new classes of high-surface area microporous electronic and ionic conductors. MOFs are crystalline materials with pore sizes ranging from 0.2 to ~ 2 nm (or larger for the latter) defined by inorganic or organic building blocks connected by rigid organic linkers. Myriad applications have been found or proposed for these materials, yet those that require electron transport or conductivity in combination with permanent porosity still lag behind because the vast majority of known frameworks are electrical insulators. Prior to our proposal and subsequent work, there were virtually no studies exploring the possibility of electronic delocalization in these materials. Therefore, our primary goal was to understand and control, at a fundamental level, the electron and ion transport properties of this class of materials, with no specific application proposed, although myriad applications could be envisioned for high surface area conductors. Our goals directly addressed one of the DOE-identified Grand Challenges for Basic Energy Sciences: designing perfect atom- and energy-efficient syntheses of revolutionary new forms of matter with tailored properties. Indeed, the proposed work is entirely synthetic in nature; owing to the molecular nature of the building blocks in MOFs, there is the possibility of unprecedented control over the structure and properties of solid crystalline matter. The goals also tangentially addressed the Grand Challenge of controlling materials processes at the level of electrons: the scope of our program is to create new materials where charges (electrons and/or ions) move according to predefined pathways.

  12. PREFACE: Introduction to Strongly Correlated Electrons in New Materials

    Science.gov (United States)

    Kusmartsev, Feo V.

    2003-09-01

    The discovery of new natural and artificial materials has revolutionized condensed matter physics and our views on the role of correlations between electrons. Novel properties such as high-temperature superconductivity and colossal magnetoresistance discovered in these materials have overturned our conventional representations of condensed matter physics and pushed us to reconsider many well-established concepts. For example, we must treat the Coulomb interaction between electrons far beyond perturbation theory; we must recall long-forgotten ideas of electronic phase separation introduced originally by Nagaev in the 1960s; we must reconsider the role of electron--phonon and electron--magnon interactions, orbital degrees of freedom, the Rashba effect and many other aspects of condensed matter physics that are becoming increasingly important. In many novel materials, such as the two-dimensional electron gas, the energy associated with the Coulomb interaction is typically of the order of (or even larger than) the kinetic energy of electrons or the Fermi energy. Therefore perturbation theory and associated renormalization group methods are not applicable to these situations and we may expect to find a novel state of matter associated with correlation effects. It is worth mentioning the known examples of these states proposed recently, such as marginal Fermi liquids, novel metal--insulator phase transitions in the two-dimensional electron gas associated with new metallic and insulating states, structured liquids, microscopic electronic phase separations, stripes, strings, polarons and others. The discussion of these states is now on the frontier of modern condensed matter physics and is partially covered in this special issue. The demand to treat the Coulomb interaction properly has stimulated a development of many-body theory, which considers correlations as fully as possible. Strong correlations may play an important role in the dynamics of the electronic system. In a

  13. Characterization of chiral mesoporous materials by transmission electron microscopy.

    Science.gov (United States)

    Ohsuna, Tetsu; Liu, Zheng; Che, Shunai; Terasaki, Osamu

    2005-02-01

    By using transmission electron microscopy (TEM), the chirality of novel mesoporous materials has been studied. In addition, a computer simulation that uses a simple structural model was employed. The existence of chiral channels inside a tubelike material was confirmed by the observation of fringes along the length of the tubes. The chiral pitch of the channels was measured from the intermittent period, the chirality (right- or left-handed) was determined from the tilt direction of a tube compared with the direction of incident electrons and the curvature direction of the curved intermitted fringes as viewed in the TEM images.

  14. Nano-structured electron transporting materials for perovskite solar cells

    Science.gov (United States)

    Liu, Hefei; Huang, Ziru; Wei, Shiyuan; Zheng, Lingling; Xiao, Lixin; Gong, Qihuang

    2016-03-01

    Organic-inorganic hybrid perovskite solar cells have been developing rapidly in the past several years, and their power conversion efficiency has reached over 20%, nearing that of polycrystalline silicon solar cells. Because the diffusion length of the hole in perovskites is longer than that of the electron, the performance of the device can be improved by using an electron transporting layer, e.g., TiO2, ZnO and TiO2/Al2O3. Nano-structured electron transporting materials facilitate not only electron collection but also morphology control of the perovskites. The properties, morphology and preparation methods of perovskites are reviewed in the present article. A comprehensive understanding of the relationship between the structure and property will benefit the precise control of the electron transporting process and thus further improve the performance of perovskite solar cells.

  15. Secondary Electron Emission Yields from PEP-II Accelerator Materials

    International Nuclear Information System (INIS)

    Kirby, Robert E.

    2000-01-01

    The PEP-II B-Factory at SLAC operates with aluminum alloy and copper vacuum chambers, having design positron and electron beam currents of 2 and 1 A, respectively. Titanium nitride coating of the aluminum vacuum chamber in the arcs of the positron ring is needed in order to reduce undesirable electron-cloud effects. The total secondary electron emission yield of TiN-coated aluminum alloy has been measured after samples of beam chamber material were exposed to air and again after electron-beam bombardment, as a function of incident electron beam angle and energy. The results may be used to simulate and better understand electron-cloud effects under actual operating conditions. We also present yield measurements for other accelerator materials because new surface effects are expected to arise as beam currents increase. Copper, in particular, is growing in popularity for its good thermal conductivity and self-radiation-shielding properties. The effect of electron bombardment, ''conditioning'', on the yield of TiN and copper is shown

  16. 77 FR 3499 - Sony Electronics, Inc., Including On-Site Leased Workers From Selectremedy Park Ridge, NJ...

    Science.gov (United States)

    2012-01-24

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,501M] Sony Electronics, Inc... Electronics, Inc., SEL Headquarters, including on-site leased workers of SelectRemedy, StaffMark, and Payrolling.com , San Diego, California (TA-W-71,501); Sony Electronics, Inc., including on-site leased...

  17. Evaluation on electrical resistivity of silicon materials after electron ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. This research deals with the study of electron beam melting (EBM) methodology utilized in melt- ing silicon material and subsequently discusses on the effect of oxygen level on electrical resistivity change after EBM process. The oxygen content was reduced from 6.177 to less than 0.0517 ppmw when refining time.

  18. Electron Charged Graphite-based Hydrogen Storage Material

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Chinbay Q. Fan; D Manager

    2012-03-14

    The electron-charge effects have been demonstrated to enhance hydrogen storage capacity using materials which have inherent hydrogen storage capacities. A charge control agent (CCA) or a charge transfer agent (CTA) was applied to the hydrogen storage material to reduce internal discharge between particles in a Sievert volumetric test device. GTI has tested the device under (1) electrostatic charge mode; (2) ultra-capacitor mode; and (3) metal-hydride mode. GTI has also analyzed the charge distribution on storage materials. The charge control agent and charge transfer agent are needed to prevent internal charge leaks so that the hydrogen atoms can stay on the storage material. GTI has analyzed the hydrogen fueling tank structure, which contains an air or liquid heat exchange framework. The cooling structure is needed for hydrogen fueling/releasing. We found that the cooling structure could be used as electron-charged electrodes, which will exhibit a very uniform charge distribution (because the cooling system needs to remove heat uniformly). Therefore, the electron-charge concept does not have any burden of cost and weight for the hydrogen storage tank system. The energy consumption for the electron-charge enhancement method is quite low or omitted for electrostatic mode and ultra-capacitor mode in comparison of other hydrogen storage methods; however, it could be high for the battery mode.

  19. Experience in nuclear materials accountancy, including the use of computers, in the UKAEA

    International Nuclear Information System (INIS)

    Anderson, A.R.; Adamson, A.S.; Good, P.T.; Terrey, D.R.

    1976-01-01

    The UKAEA have operated systems of nuclear materials accountancy in research and development establishments handling large quantities of material for over 20 years. In the course of that time changing requirements for nuclear materials control and increasing quantities of materials have required that accountancy systems be modified and altered to improve either the fundamental system or manpower utilization. The same accountancy principles are applied throughout the Authority but procedures at the different establishments vary according to the nature of their specific requirements; there is much in the cumulative experience of the UKAEA which could prove of value to other organizations concerned with nuclear materials accountancy or safeguards. This paper reviews the present accountancy system in the UKAEA and summarizes its advantages. Details are given of specific experience and solutions which have been found to overcome difficulties or to strengthen previous weak points. Areas discussed include the use of measurements, the establishment of measurement points (which is relevant to the designation of MBAs), the importance of regular physical stock-taking, and the benefits stemming from the existence of a separate accountancy section independent of operational management at large establishments. Some experience of a dual system of accountancy and criticality control is reported, and the present status of computerization of nuclear material accounts is summarized. Important aspects of the relationship between management systems of accountancy and safeguards' requirements are discussed briefly. (author)

  20. Ceramic materials on perovskite-type structure for electronic applications

    International Nuclear Information System (INIS)

    Surowiak, Z.

    2003-01-01

    Ceramic materials exhibiting the perovskite-type structure constitute among others, resource base for many fields of widely understood electronics (i.e., piezoelectronics, accustoelectronics, optoelectronics, computer science, tele- and radioelectronics etc.). Most often they are used for fabrication of different type sensors (detectors), transducers, ferroelectric memories, limiters of the electronic current intensity, etc., and hence they are numbered among so-called intelligent materials. Prototype structure of this group of materials is the structure of the mineral called perovskite (CaTiO 3 ). By means of right choice of the chemical composition of ABO 3 and deforming the regular perovskite structure (m3m) more than 5000 different chemical compounds and solid solutions exhibiting the perovskite-type structure have been fabricated. The concept of perovskite functional ceramics among often things ferroelectric ceramics, pyroelectric ceramics, piezoelectric ceramics, electrostrictive ceramics, posistor ceramics, superconductive ceramics and ferromagnetic ceramics. New possibilities of application of the perovskite-type ceramics are opened by nanotechnology. (author)

  1. New Nuclear Materials Including Non Metallic Fuel Elements. Vol. II. Proceedings of the Conference on New Nuclear Materials Technology, Including Non Metallic Fuel Elements

    International Nuclear Information System (INIS)

    1963-01-01

    One of the major aims of the International Atomic Energy Agency in furthering the peaceful uses of atomic energy is to encourage the development of economical nuclear power. Certainly, one of the more obvious methods of producing economical nuclear power is the development of economical fuels that can be used at high temperatures for long periods of time, and which have sufficient strength and integrity to operate under these conditions without permitting the release of fission products. In addition it is desirable that after irradiation these new fuels be economically reprocessed to reduce further the cost of the fuel cycle. As nuclear power becomes more and more competitive with conventional power the interest in new and more efficient higher-temperature fuels naturally increases rapidly. For these reasons, the Agency organized a Conference on New Nuclear Materials Technology, Including Non-Metallic Fuel Elements, which was held from 1 to 5 July 1963 at the International Hotel, Prague, with the assistance and co-operation of the Government of the Czechoslovak Socialist Republic. A total of 151 scientists attended, from 23 countries and 4 international organizations. The participants heard and discussed more than 60 scientific papers. The Agency wishes to thank the scientists who attended this Conference for their papers and for many spirited discussions that truly mark a successful meeting. The Agency wishes also to record its gratitude for the assistance and generous hospitality accorded the Conference, the participants and the Agency's staff by the Government of the Czechoslovak Socialist Republic and by the people of Prague. The scientific information contained in these Proceedings should help to quicken the pace of progress in the fabrication of new and m ore economical fuels, and it is hoped that these proceedings will be found useful to all workers in this and related fields

  2. First Principles Calculations of Electronic Excitations in 2D Materials

    DEFF Research Database (Denmark)

    Rasmussen, Filip Anselm

    Since the first reported synthesization of graphene ̣- an atomically thin carbon material - in 2004 there has been a surge of research in discovering other novel two-dimensional materials. The reason is clear: two-dimensional materials are thought to be able to lead to new fast and low-power ultra...... mechanics methods. One of these methods, Density Functional Theory (DFT), has been very successful at determining structural properties of 2D materials. It is however well-known that it less accurate when it comes to predicting the energy levels of excited states that are important in order to determine...... of the numerical methods that are efficient for bulk systems become invalid. In this thesis I describe the study of a set of novel 2D materials and establish their electronic and optical properties using DFT and the GW approximation while taking the reduced screening properly into account as well as taking regard...

  3. Three-dimensional free electron laser dispersion relation including betatron oscillations

    International Nuclear Information System (INIS)

    Chin, Y.H.; Kim, K.J.; Xie, M.

    1991-08-01

    We have developed a 3-D FEL theory based upon the Maxwell-Vlasov equations including the effects of the energy spread and emittance of the electron beam, and of betatron oscillations. The radiation field is expressed in terms of the Green's function of the inhomogeneous wave equation and the distribution function of the electron beam. The distribution function is expanded in terms of a set of orthogonal functions determined by the unperturbed particle distribution. The coupled Maxwell-Vlasov equations are then reduced to a matrix equation, from which a dispersion relation for the eigenvalues is derived. In the limit of small betatron oscillation frequency, the present dispersion relation reduces to the well-known cubic equation of the one-dimensional theory in the limit of large beam size, and it gives the correct gain in the limit of small beam size. Comparisons of our numerical results with other approaches show good agreement. We present a handy empirical formula for the FEL gain of a 3-D Gaussian beam, as a function of the scaled parameters, that can be used for a quick estimate of the grain. 5 refs., 2 figs

  4. Electron spin resonance studies of radiation effects. Final report, 1964-1979 (including annual progress reports for 1978 and 1979)

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, M.T.

    1979-07-01

    The discovery of new free radicals, largely in irradiated single crystals of nonmetallic solids, and the determination of the molecular and electronic structures of these paramagnetic species by electron spin resonance (ESR) spectroscopy, have been carried out using a wide variety of organic and inorganic materials. The mechanisms of production of radicals in solids, their motions, and their reactions have been investigated and some applicable general principles deduced. Emphasis has been on aliphatic free radicals from irradiated carboxylic acids and amides and their halogen-substituted derivatives, organometallic radicals and substituted cyclic hydrocarbon radicals; inorganic radicals studied include V centers, hypervalent radicals and electron adducts. Extensive investigations of paramagnetic transition metal complexes, particularly cyanides and fluorides, have been made. In all cases quantum mechanical calculations have been employed as far as possible in interpreting the data. An improved method for analyzing experimental ESR spectra of single crystals has been developed and a number of crystal structures have been determined to supplement the ESR studies. Applications of nuclear quadrupole resonance spectroscopy to the study of structure and bonding in inorganic solids have been made and a method for using nuclear magnetic relaxation data for estimating quadrupole coupling constants in liquids has been developed.

  5. Materials and processing approaches for foundry-compatible transient electronics

    Science.gov (United States)

    Chang, Jan-Kai; Fang, Hui; Bower, Christopher A.; Song, Enming; Yu, Xinge; Rogers, John A.

    2017-07-01

    Foundry-based routes to transient silicon electronic devices have the potential to serve as the manufacturing basis for “green” electronic devices, biodegradable implants, hardware secure data storage systems, and unrecoverable remote devices. This article introduces materials and processing approaches that enable state-of-the-art silicon complementary metal-oxide-semiconductor (CMOS) foundries to be leveraged for high-performance, water-soluble forms of electronics. The key elements are (i) collections of biodegradable electronic materials (e.g., silicon, tungsten, silicon nitride, silicon dioxide) and device architectures that are compatible with manufacturing procedures currently used in the integrated circuit industry, (ii) release schemes and transfer printing methods for integration of multiple ultrathin components formed in this way onto biodegradable polymer substrates, and (iii) planarization and metallization techniques to yield interconnected and fully functional systems. Various CMOS devices and circuit elements created in this fashion and detailed measurements of their electrical characteristics highlight the capabilities. Accelerated dissolution studies in aqueous environments reveal the chemical kinetics associated with the underlying transient behaviors. The results demonstrate the technical feasibility for using foundry-based routes to sophisticated forms of transient electronic devices, with functional capabilities and cost structures that could support diverse applications in the biomedical, military, industrial, and consumer industries.

  6. Analysis of electronic models for solar cells including energy resolved defect densities

    Energy Technology Data Exchange (ETDEWEB)

    Glitzky, Annegret

    2010-07-01

    We introduce an electronic model for solar cells including energy resolved defect densities. The resulting drift-diffusion model corresponds to a generalized van Roosbroeck system with additional source terms coupled with ODEs containing space and energy as parameters for all defect densities. The system has to be considered in heterostructures and with mixed boundary conditions from device simulation. We give a weak formulation of the problem. If the boundary data and the sources are compatible with thermodynamic equilibrium the free energy along solutions decays monotonously. In other cases it may be increasing, but we estimate its growth. We establish boundedness and uniqueness results and prove the existence of a weak solution. This is done by considering a regularized problem, showing its solvability and the boundedness of its solutions independent of the regularization level. (orig.)

  7. Flexible barrier film, method of forming same, and organic electronic device including same

    Science.gov (United States)

    Blizzard, John; Tonge, James Steven; Weidner, William Kenneth

    2013-03-26

    A flexible barrier film has a thickness of from greater than zero to less than 5,000 nanometers and a water vapor transmission rate of no more than 1.times.10.sup.-2 g/m.sup.2/day at 22.degree. C. and 47% relative humidity. The flexible barrier film is formed from a composition, which comprises a multi-functional acrylate. The composition further comprises the reaction product of an alkoxy-functional organometallic compound and an alkoxy-functional organosilicon compound. A method of forming the flexible barrier film includes the steps of disposing the composition on a substrate and curing the composition to form the flexible barrier film. The flexible barrier film may be utilized in organic electronic devices.

  8. 77 FR 18860 - Certain Consumer Electronics, Including Mobile Phones and Tablets; Notice of Receipt of Complaint...

    Science.gov (United States)

    2012-03-28

    ...; Research In Motion Corp. of TX; Samsung Electronics Co., Ltd. of South Korea; Samsung Electronics America, Inc. of NJ; and Samsung Telecommunications America, LLC of TX. Proposed respondents, other interested...

  9. 77 FR 24514 - Certain Consumer Electronics, Including Mobile Phones and Tablets; Institution of Investigation...

    Science.gov (United States)

    2012-04-24

    ..., Taiwan; HTC America, Inc., 13920 SE Eastgate Way, Suite 400, Bellevue, WA 98005; LG Electronics, Inc., LG Twin Towers, 20, Yoido-dong, Youngdungpo-gu, Seoul, 157-721, Republic of Korea; LG Electronics U.S.A., Inc., 1000 Sylvan Ave., Englewood Cliffs, NJ 07632; LG Electronics MobileComm U.S.A., Inc., 10101 Old...

  10. Adhesives technology for electronic applications materials, processing, reliability

    CERN Document Server

    Licari, James J

    2011-01-01

    Adhesives are widely used in the manufacture and assembly of electronic circuits and products. Generally, electronics design engineers and manufacturing engineers are not well versed in adhesives, while adhesion chemists have a limited knowledge of electronics. This book bridges these knowledge gaps and is useful to both groups. The book includes chapters covering types of adhesive, the chemistry on which they are based, and their properties, applications, processes, specifications, and reliability. Coverage of toxicity, environmental impacts and the regulatory framework make this book par

  11. Managing nuclear knowledge: IAEA activities and international coordination. Including resource material full text CD-ROM

    International Nuclear Information System (INIS)

    2005-06-01

    The present CD-ROM summarizes some activities carried out by the Departments of Nuclear Energy and Nuclear Safety and Security in the area of nuclear knowledge management in the period 2003-2005. It comprises, as open resource, most of the relevant documents in full text, including policy level documents, reports, presentation material by Member States and meeting summaries. The collection starts with a reprint of the report to the IAEA General Conference 2004 on Nuclear Knowledge [GOV/2004/56-GC(48)/12] summarizing the developments in nuclear knowledge management since the 47th session of the General Conference in 2003 and covers Managing Nuclear Knowledge including safety issues and Information and Strengthening Education and Training for Capacity Building. It contains an excerpt on Nuclear Knowledge from the General Conference Resolution [GC(48)/RES/13] on Strengthening the Agency's Activities Related to Nuclear Science, Technology and Applications. On the CD-ROM itself, all documents can easily be accessed by clicking on their titles on the subject pages (also printed at the end of this Working Material). Part 1 of the CD-ROM covers the activities in the period 2003-2005 and part 2 presents a resource material full text CD-ROM on Managing Nuclear Knowledge issued in October 2003

  12. Electron Acceptor Materials Engineering in Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Liu, Huan

    2011-07-15

    Lead sulfide colloidal quantum dot (CQD) solar cells with a solar power conversion efficiency of 5.6% are reported. The result is achieved through careful optimization of the titanium dioxide electrode that serves as the electron acceptor. Metal-ion-doped sol-gel-derived titanium dioxide electrodes produce a tunable-bandedge, well-passivated materials platform for CQD solar cell optimization. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Radiation effects on and dose enhancement of electronic materials

    International Nuclear Information System (INIS)

    Srour, J.R.; Long, D.M.

    1984-01-01

    This book describes radiation effects on and dose enhancement factors for electronic materials. Alteration of the electrical properties of solid-state devices and integrated circuits by impinging radiation is well-known. Such changes may cause an electronic subsystem to fail, thus there is currently great interest in devising methods for avoiding radiation-induced degradation. The development of radiation-hardened devices and circuits is an exciting approach to solving this problem for many applications, since it could minimize the need for shielding or other system hardening techniques. Part 1 describes the basic mechanisms of radiation effects on electronic materials, devices, and integrated circuits. Radiation effects in bulk silicon and in silicon devices are treated. Ionizing radiation effects in silicon dioxide films and silicon MOS devices are discussed. Single event phenomena are considered. Key literature references and a bibliography are provided. Part II provides tabulations of dose enhancement factors for electronic devices in x-ray and gamma-ray environments. The data are applicable to a wide range of semiconductor devices and selected types of capacitors. Radiation environments discussed find application in system design and in radiation test facilities

  14. Commentary on guidelines for radiation measurement and treatment of substances including naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Sakurai, Naoyuki; Ishiguro, Hideharu

    2007-01-01

    Study group on safety regulation on research reactors in Ministry of Education, Culture, Sports, Science and Technology (MEXT) reported the guidelines of 'Guidelines on radiation measurement and treatment of naturally occurring radioactive materials (NORM)' on 6 February 2006. RANDEC made the website contents 'Study on use and safety of the substances including uranium or thorium', based on the contract with MEXT to make theirs contents. This paper describes the outline of the website in MEXT homepage, background and contents of NORM guidelines in order to understand easily and visually the NORM guidelines, adding in some flowcharts and figures. (author)

  15. Spatiotemporal Observation of Electron-Impact Dynamics in Photovoltaic Materials Using 4D Electron Microscopy

    KAUST Repository

    Shaheen, Basamat

    2017-05-17

    Understanding light-triggered charge carrier dynamics near photovoltaic-material surfaces and at interfaces has been a key element and one of the major challenges for the development of real-world energy devices. Visualization of such dynamics information can be obtained using the one-of-a-kind methodology of scanning ultrafast electron microscopy (S-UEM). Here, we address the fundamental issue of how the thickness of the absorber layer may significantly affect the charge carrier dynamics on material surfaces. Time-resolved snapshots indicate that the dynamics of charge carriers generated by electron impact in the electron-photon dynamical probing regime is highly sensitive to the thickness of the absorber layer, as demonstrated using CdSe films of different thicknesses as a model system. This finding not only provides the foundation for potential applications of S-UEM to a wide range of devices in the fields of chemical and materials research, but also has impact on the use and interpretation of electron beam-induced current for optimization of photoactive materials in these devices.

  16. Spatiotemporal Observation of Electron-Impact Dynamics in Photovoltaic Materials Using 4D Electron Microscopy.

    Science.gov (United States)

    Shaheen, Basamat S; Sun, Jingya; Yang, Ding-Shyue; Mohammed, Omar F

    2017-06-01

    Understanding light-triggered charge carrier dynamics near photovoltaic-material surfaces and at interfaces has been a key element and one of the major challenges for the development of real-world energy devices. Visualization of such dynamics information can be obtained using the one-of-a-kind methodology of scanning ultrafast electron microscopy (S-UEM). Here, we address the fundamental issue of how the thickness of the absorber layer may significantly affect the charge carrier dynamics on material surfaces. Time-resolved snapshots indicate that the dynamics of charge carriers generated by electron impact in the electron-photon dynamical probing regime is highly sensitive to the thickness of the absorber layer, as demonstrated using CdSe films of different thicknesses as a model system. This finding not only provides the foundation for potential applications of S-UEM to a wide range of devices in the fields of chemical and materials research, but also has impact on the use and interpretation of electron beam-induced current for optimization of photoactive materials in these devices.

  17. Effective atomic numbers and electron density of dosimetric material

    Directory of Open Access Journals (Sweden)

    Kaginelli S

    2009-01-01

    Full Text Available A novel method for determination of mass attenuation coefficient of x-rays employing NaI (Tl detector system and radioactive sources is described.in this paper. A rigid geometry arrangement and gating of the spectrometer at FWHM position and selection of absorber foils are all done following detailed investigation, to minimize the effect of small angle scattering and multiple scattering on the mass attenuation coefficient, m/r, value. Firstly, for standardization purposes the mass attenuation coefficients of elemental foils such as Aluminum, Copper, Molybdenum, Tantalum and Lead are measured and then, this method is utilized for dosimetric interested material (sulfates. The experimental mass attenuation coefficient values are compared with the theoretical values to find good agreement between the theory and experiment within one to two per cent. The effective atomic numbers of the biological substitute material are calculated by sum rule and from the graph. The electron density of dosimetric material is calculated using the effective atomic number. The study has discussed in detail the attenuation coefficient, effective atomic number and electron density of dosimetric material/biological substitutes.

  18. Transmission electron microscopy a textbook for materials science

    CERN Document Server

    Williams, David B

    1996-01-01

    Electron microscopy has revolutionized our understanding the extraordinary intellectual demands required of the mi­ of materials by completing the processing-structure-prop­ croscopist in order to do the job properly: crystallography, erties links down to atomistic levels. It now is even possible diffraction, image contrast, inelastic scattering events, and to tailor the microstructure (and meso structure ) of materials spectroscopy. Remember, these used to be fields in them­ to achieve specific sets of properties; the extraordinary abili­ selves. Today, one has to understand the fundamentals ties of modem transmission electron microscopy-TEM­ of all of these areas before one can hope to tackle signifi­ instruments to provide almost all of the structural, phase, cant problems in materials science. TEM is a technique of and crystallographic data allow us to accomplish this feat. characterizing materials down to the atomic limits. It must Therefore, it is obvious that any curriculum in modem mate­ be use...

  19. Monitoring system including an electronic sensor platform and an interrogation transceiver

    Science.gov (United States)

    Kinzel, Robert L.; Sheets, Larry R.

    2003-09-23

    A wireless monitoring system suitable for a wide range of remote data collection applications. The system includes at least one Electronic Sensor Platform (ESP), an Interrogator Transceiver (IT) and a general purpose host computer. The ESP functions as a remote data collector from a number of digital and analog sensors located therein. The host computer provides for data logging, testing, demonstration, installation checkout, and troubleshooting of the system. The IT transmits signals from one or more ESP's to the host computer to the ESP's. The IT host computer may be powered by a common power supply, and each ESP is individually powered by a battery. This monitoring system has an extremely low power consumption which allows remote operation of the ESP for long periods; provides authenticated message traffic over a wireless network; utilizes state-of-health and tamper sensors to ensure that the ESP is secure and undamaged; has robust housing of the ESP suitable for use in radiation environments; and is low in cost. With one base station (host computer and interrogator transceiver), multiple ESP's may be controlled at a single monitoring site.

  20. Investigation of electronic transport through a ladder-like graphene nanoribbon including random distributed impurities

    Science.gov (United States)

    Esmaili, Esmat; Mardaani, Mohammad; Rabani, Hassan

    2018-01-01

    The electronic transport of a ladder-like graphene nanoribbon which the on-site or hopping energies of a small part of it can be random is modeled by using the Green's function technique within the nearest neighbor tight-binding approach. We employ a unitary transformation in order to convert the Hamiltonian of the nanoribbon to the Hamiltonian of a tight-binding ladder-like network. In this case, the disturbed part of the system includes the second neighbor hopping interactions. While, the converted Hamiltonian of each ideal part is equivalent to the Hamiltonian of two periodic on-site chains. Therefore, we can insert the self-energies of the alternative on-site tight-binding chains to the inverse of the Green's function matrix of the ladder-like part. In this viewpoint, the conductance is constructed from two trans and cis contributions. The results show that increasing the disorder strength causes the increase and decrease of the conductance of the trans and cis contributions, respectively.

  1. Development of nanocomposite polymer materials for electrical and electronic applications

    International Nuclear Information System (INIS)

    Chine, Bruno

    2007-01-01

    Some results and experimental procedures of laboratory are reported in the frame of researches conducted for the development of new nanostructured composite materials. These new materials, which are constituted by an organic phase: the polymer and an inorganic phase: the silicate, are being strongly investigated nowadays so it is expected that they could provide, among other, better electrical insulation properties and flame-delay in electrical and electronic applications. The laboratory experimental work has been developed from two families of polymers, thermoplastics and thermosets and clays silicates providing lamellar type. There are now some preliminary results, such as obtaining thin films of these nanocomposite materials, their complete characterization by X-ray diffraction, scanning microscopy and thermogravimetric analysis, they do well to wait for future research activities. (author) [es

  2. [The innovative dynamic of the mechanics, electronics and materials subsystem].

    Science.gov (United States)

    Maldonado, José; Gadelha, Carlos Augusto Grabois; Costa, Laís Silveira; Vargas, Marco

    2012-12-01

    The mechanics, electronics and materials subsystem, one of the subsystems of the health care productive complex, encompasses different activities, usually clustered in what is called the medical, hospital and dental equipment and materials industry. This is a strategic area for health care, since it represents a continuous source of changes in care practices, and influences the provision of health care services. It has, moreover, potential for promoting the progress of Brazil's system of innovation and for increasing the competitiveness of the industry as a whole, given that it articulates future technologies. Despite the significant growth of this industry in Brazil in recent years, such equipment and materials have been presenting a growing deficit in the balance of trade. This incompatibility between national health care needs and the productive and innovative basis of the industry points to structural fragilities in the system. Using the framework of political economy, the article aims to discuss the development of this industry in Brazil and its challenges.

  3. Combined modality therapy including intraoperative electron irradiation for locally recurrent colorectal cancer.

    Science.gov (United States)

    Haddock, Michael G; Miller, Robert C; Nelson, Heidi; Pemberton, John H; Dozois, Eric J; Alberts, Steven R; Gunderson, Leonard L

    2011-01-01

    To evaluate survival, relapse patterns, and prognostic factors in patients with colorectal cancer relapse treated with curative-intent therapy, including intraoperative electron radiation therapy (IOERT). From April 1981 through January 2008, 607 patients with recurrent colorectal cancer received IOERT as a component of treatment. IOERT was preceded or followed by external radiation (median dose, 45.5 Gy) in 583 patients (96%). Resection was classified as R0 in 227 (37%), R1 in 224 (37%), and R2 in 156 (26%). The median IOERT dose was 15 Gy (range, 7.5-30 Gy). Median overall survival was 36 months. Five- and 10-year survival rates were 30% and 16%, respectively. Survival estimates at 5 years were 46%, 27%, and 16% for R0, R1, and R2 resection, respectively. Multivariate analysis revealed that R0 resection, no prior chemotherapy, and more recent treatment (in the second half of the series) were associated with improved survival. The 3-year cumulative incidence of central, local, and distant relapse was 12%, 23%, and 49%, respectively. Central and local relapse were more common in previously irradiated patients and in those with subtotal resection. Toxicity Grade 3 or higher partially attributable to IOERT was observed in 66 patients (11%). Neuropathy was observed in 94 patients (15%) and was more common with IOERT doses exceeding 12.5 Gy. Long-term survival and disease control was achievable in patients with locally recurrent colorectal cancer. Continued evaluation of curative-intent, combined-modality therapy that includes IOERT is warranted in this high-risk population. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. 78 FR 13895 - Certain Consumer Electronics, Including Mobile Phones and Tablets; Commission Determination Not...

    Science.gov (United States)

    2013-03-01

    ... Motion Ltd. of Ontario, Canada and Research In Motion Corp. of Irving, Texas; Samsung Electronics Co., Ltd of Seoul, Republic of Korea, Samsung Electronics America, Inc. of Ridgefield Park, New Jersey, and Samsung Telecommunications America, L.L.C. of Richardson, Texas as respondents. Id. The Commission's...

  5. Two-dimensional materials based transparent flexible electronics

    Science.gov (United States)

    Yu, Lili; Ha, Sungjae; El-Damak, Dina; McVay, Elaine; Ling, Xi; Chandrakasan, Anantha; Kong, Jing; Palacios, Tomas

    2015-03-01

    Two-dimensional (2D) materials have generated great interest recently as a set of tools for electronics, as these materials can push electronics beyond traditional boundaries. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. These thin, lightweight, bendable, highly rugged and low-power devices may bring dramatic changes in information processing, communications and human-electronic interaction. In this report, for the first time, we demonstrate two complex transparent flexible systems based on molybdenum disulfide (MoS2) grown by chemical vapor method: a transparent active-matrix organic light-emitting diode (AMOLED) display and a MoS2 wireless link for sensor nodes. The 1/2 x 1/2 square inch, 4 x 5 pixels AMOLED structures are built on transparent substrates, containing MoS2 back plane circuit and OLEDs integrated on top of it. The back plane circuit turns on and off the individual pixel with two MoS2 transistors and a capacitor. The device is designed and fabricated based on SPICE simulation to achieve desired DC and transient performance. We have also demonstrated a MoS2 wireless self-powered sensor node. The system consists of as energy harvester, rectifier, sensor node and logic units. AC signals from the environment, such as near-field wireless power transfer, piezoelectric film and RF signal, are harvested, then rectified into DC signal by a MoS2 diode. CIQM, CICS, SRC.

  6. Electronic materials with a wide band gap: recent developments

    Directory of Open Access Journals (Sweden)

    Detlef Klimm

    2014-09-01

    Full Text Available The development of semiconductor electronics is reviewed briefly, beginning with the development of germanium devices (band gap Eg = 0.66 eV after World War II. A tendency towards alternative materials with wider band gaps quickly became apparent, starting with silicon (Eg = 1.12 eV. This improved the signal-to-noise ratio for classical electronic applications. Both semiconductors have a tetrahedral coordination, and by isoelectronic alternative replacement of Ge or Si with carbon or various anions and cations, other semiconductors with wider Eg were obtained. These are transparent to visible light and belong to the group of wide band gap semiconductors. Nowadays, some nitrides, especially GaN and AlN, are the most important materials for optical emission in the ultraviolet and blue regions. Oxide crystals, such as ZnO and β-Ga2O3, offer similarly good electronic properties but still suffer from significant difficulties in obtaining stable and technologically adequate p-type conductivity.

  7. Electron tomography of porous materials and magnetic nanoparticles

    International Nuclear Information System (INIS)

    Uusimäki, T.

    2015-01-01

    Electron tomography, as carried out in a transmission electron microscope is a method to reveal the three dimensional structure of the sample at the nanometer scale. It is based on tilting the sample and recording subsequent images at different projections angles. Using specific reconstruction algorithms the density distribution of the sample can then be reproduced. In this thesis, electron tomography has been implemented for material science specimens and more rigorously to porous media infiltrated with magnetic nanoparticles. The volume and spatial distribution along with the knowledge of the demagnetizing factors were then used within a magnetic Monte Carlo simulation to predict the magnetic response of the nanoparticle assembly. The local curvature of nanoparticles within the template, known to be a critical geometrical parameter influencing material properties, was extracted with two distinctive methods. Furthermore, new capabilities needed for image analysis and processing of the tilt series had to be implemented for improved alignments and segmentation. A new method to align the tilt series without depending on markers was written for obtaining high quality reconstructions. Also a comparison was made between different scanning TEM acquisition modes such as incoherent bright field and high angle annular dark field imaging modes with respect to resolution and contrast changes. (author) [de

  8. Electronic Properties of Low-Dimensional Materials Under Periodic Potential

    Science.gov (United States)

    Jamei, Mehdi

    In the quest for the further miniaturization of electronic devices, numerous fabrication techniques have been developed. The semiconductor industry has been able to manifest miniaturization in highly complex and ultra low-power integrated circuits and devices, transforming almost every aspect of our lives. However, we may have come very close to the end of this trend. While advanced machines and techniques may be able to overcome technological barriers, theoretical and fundamental barriers are inherent to the top-down miniaturization approach and cannot be circumvented. As a result, the need for novel and natural alternatives to replace old materials is valued now more than ever. Fortunately, there exists a large group of materials that essentially has low-dimensional (quasi-one- or quasi-two-dimensional) structures. Graphene, a two-dimensional form of carbon, which has attracted a lot of attention in recent years, is a perfect example of a prime material from this group. Niobium tri-selenide (NbSe3), from a family of trichalcogenides, has a highly anisotropic structure and electrical conductivity. At sufficiently low temperatures, NbSe3 also exhibits two independent "sliding charge density waves"-- an exciting phenomenon, which could be altered by changing the overall size of the material. In NbSe3 (and Blue Bronze K0.3MoO3 which has a similar structure and electrical behavior), the effect of a periodic potential could be seen in creating a charge density wave (CDW) that is incommensurate to the underlying lattice. The required periodic potential is provided by the crystal ions when ordered in a particular way. The consequence is a peculiar non-linear conductivity behavior, as well as a unique narrow-band noise spectrum. Theoretical and experimental studies have concluded that the dynamic properties of resulting CDW are directly related to the crystal impurity density, and other pinning potentials. Therefore, reducing the overall size of the crystal could

  9. Flexible diodes for radio frequency (RF) electronics: a materials perspective

    Science.gov (United States)

    Semple, James; Georgiadou, Dimitra G.; Wyatt-Moon, Gwenhivir; Gelinck, Gerwin; Anthopoulos, Thomas D.

    2017-12-01

    Over the last decade, there has been increasing interest in transferring the research advances in radiofrequency (RF) rectifiers, the quintessential element of the chip in the RF identification (RFID) tags, obtained on rigid substrates onto plastic (flexible) substrates. The growing demand for flexible RFID tags, wireless communications applications and wireless energy harvesting systems that can be produced at a low-cost is a key driver for this technology push. In this topical review, we summarise recent progress and status of flexible RF diodes and rectifying circuits, with specific focus on materials and device processing aspects. To this end, different families of materials (e.g. flexible silicon, metal oxides, organic and carbon nanomaterials), manufacturing processes (e.g. vacuum and solution processing) and device architectures (diodes and transistors) are compared. Although emphasis is placed on performance, functionality, mechanical flexibility and operating stability, the various bottlenecks associated with each technology are also addressed. Finally, we present our outlook on the commercialisation potential and on the positioning of each material class in the RF electronics landscape based on the findings summarised herein. It is beyond doubt that the field of flexible high and ultra-high frequency rectifiers and electronics as a whole will continue to be an active area of research over the coming years.

  10. Flexible diodes for radio frequency (RF) electronics: a materials perspective

    KAUST Repository

    Semple, James

    2017-10-30

    Over the last decade, there has been increasing interest in transferring the research advances in radiofrequency (RF) rectifiers, the quintessential element of the chip in the RF identification (RFID) tags, obtained on rigid substrates onto plastic (flexible) substrates. The growing demand for flexible RFID tags, wireless communications applications and wireless energy harvesting systems that can be produced at a low-cost is a key driver for this technology push. In this topical review, we summarise recent progress and status of flexible RF diodes and rectifying circuits, with specific focus on materials and device processing aspects. To this end, different families of materials (e.g. flexible silicon, metal oxides, organic and carbon nanomaterials), manufacturing processes (e.g. vacuum and solution processing) and device architectures (diodes and transistors) are compared. Although emphasis is placed on performance, functionality, mechanical flexibility and operating stability, the various bottlenecks associated with each technology are also addressed. Finally, we present our outlook on the commercialisation potential and on the positioning of each material class in the RF electronics landscape based on the findings summarised herein. It is beyond doubt that the field of flexible high and ultra-high frequency rectifiers and electronics as a whole will continue to be an active area of research over the coming years.

  11. OCV Hysteresis in Li-Ion Batteries including Two-Phase Transition Materials

    Directory of Open Access Journals (Sweden)

    Michael A. Roscher

    2011-01-01

    Full Text Available The relation between batteries' state of charge (SOC and open-circuit voltage (OCV is a specific feature of electrochemical energy storage devices. Especially NiMH batteries are well known to exhibit OCV hysteresis, and also several kinds of lithium-ion batteries show OCV hysteresis, which can be critical for reliable state estimation issues. Electrode potential hysteresis is known to result from thermodynamical entropic effects, mechanical stress, and microscopic distortions within the active electrode materials which perform a two-phase transition during lithium insertion/extraction. Hence, some Li-ion cells including two-phase transition active materials show pronounced hysteresis referring to their open-circuit voltage. This work points out how macroscopic effects, that is, diffusion limitations, superimpose the latte- mentioned microscopic mechanisms and lead to a shrinkage of OCV hysteresis, if cells are loaded with high current rates. To validate the mentioned interaction, Li-ion cells' state of charge is adjusted to 50% with various current rates, beginning from the fully charged and the discharged state, respectively. As a pronounced difference remains between the OCV after charge and discharge adjustment, obviously the hysteresis vanishes as the target SOC is adjusted with very high current rate.

  12. Process For Controlling Flow Rate Of Viscous Materials Including Use Of Nozzle With Changeable Openings

    Science.gov (United States)

    Ellingson, William A.; Forster, George A.

    1999-11-02

    Apparatus and a method for controlling the flow rate of viscous materials through a nozzle includes an apertured main body and an apertured end cap coupled together and having an elongated, linear flow channel extending the length thereof. An end of the main body is disposed within the end cap and includes a plurality of elongated slots concentrically disposed about and aligned with the flow channel. A generally flat cam plate having a center aperture is disposed between the main body and end cap and is rotatable about the flow channel. A plurality of flow control vane assemblies are concentrically disposed about the flow channel and are coupled to the cam plate. Each vane assembly includes a vane element disposed adjacent the end of the flow channel. Rotation of the cam plate in a first direction causes a corresponding rotation of each of the vane elements for positioning the individual vane elements over the aperture in the end cap blocking flow through the flow channel, while rotation in an opposite direction removes the vane elements from the aperture and positions them about the flow channel in a nested configuration in the full open position, with a continuous range of vane element positions available between the full open and closed positions.

  13. Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science.

    Science.gov (United States)

    Shindo, Daisuke; Tanigaki, Toshiaki; Park, Hyun Soon

    2017-07-01

    Advances and applications of electron holography to the study of electromagnetic fields in various functional materials are presented. In particular, the development of split-illumination electron holography, which introduces a biprism in the illumination system of a holography electron microscope, enables highly accurate observations of electromagnetic fields and the expansion of the observable area. First, the charge distributions on insulating materials were studied by using split-illumination electron holography and including a mask in the illumination system. Second, the three-dimensional spin configurations of skyrmion lattices in a helimagnet were visualized by using a high-voltage holography electron microscope. Third, the pinning of the magnetic flux lines in a high-temperature superconductor YBa 2 Cu 3 O 7-y was analyzed by combining electron holography and scanning ion microscopy. Finally, the dynamic accumulation and collective motions of electrons around insulating biomaterial surfaces were observed by utilizing the amplitude reconstruction processes of electron holography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Simulation tool for optical design of PET detector modules including scintillator material and sensor array

    Energy Technology Data Exchange (ETDEWEB)

    Jatekos, B.; Erdei, G.; Lorincz, E. [Budapest Univ. of Technology and Economics, Dept. of Atomic Physics, Budafoki ut 8, H-1111 Budapest (Hungary)

    2011-07-01

    The appearance of single photon avalanche diodes (SPADs) in the field of PET detector modules made it necessary to apply more complex optical design methods to refine the performance of such assemblies. We developed a combined simulation tool that is capable to model complex detector structures including scintillation material, light guide, light collection optics and sensor, correctly taking into account the statistical behavior of emission of scintillation light and its absorbance in SPADs. As a validation we compared simulation results obtained by our software and another optical design program. Calculations were performed for a simple PET detector arrangement used for testing purposes. According to the results, deviation of center of gravity coordinates between the two simulations is 0.0195 mm, the average ratio of total counts 1.0052. We investigated the error resulting from finite sampling in wavelength space and we found that 20 nm pitch is sufficient for the simulation in case of the given spectral dependencies. (authors)

  15. Electron microscopy of fine-grained extraterrestrial materials

    International Nuclear Information System (INIS)

    Mackinnon, I.D.R.; McKay, D.S.; Isaacs, A.M.; Nace, G.

    1982-01-01

    Electron micrographs are shown of (a) Mighei C2 carbonaceous chondrite (variety of matrix phases present; micro-diffraction patterns of a region showing small, discrete intergrowths of planar serpentine and an ordered mixed-layer material; figures showing examples of textures which may be interpreted in terms of alteration processes, and inclusions); and (b) a typical cosmic dust particle collected by high-flying aircraft in the Earth's stratosphere. The composition and morphology of the samples are discussed and their significance. (U.K.)

  16. Physical methods for studying minerals and solid materials: X-ray, electron and neutron diffraction; scanning and transmission electron microscopy; X-ray, electron and ion spectrometry

    International Nuclear Information System (INIS)

    Eberhart, J.-P.

    1976-01-01

    The following topics are discussed: theoretical aspects of radiation-matter interactions; production and measurement of radiations (X rays, electrons, neutrons); applications of radiation interactions to the study of crystalline materials. The following techniques are presented: X-ray and neutron diffraction, electron microscopy, electron diffraction, X-ray fluorescence analysis, electron probe microanalysis, surface analysis by electron emission spectrometry (ESCA and Auger electrons), scanning electron microscopy, secondary ion emission analysis [fr

  17. Specialists meeting on properties of primary circuit structural materials including environmental effects

    International Nuclear Information System (INIS)

    1977-01-01

    The Specialists Meeting on Properties of Primary Circuit Structural Materials of LMFBRs covered the following topics: overview of materials program in different countries; mechanical properties of materials in air; fracture mechanics studies - component related activities; impact of environmental influences on mechanical properties; relationship of material properties and design methods. The purpose of the meeting was to provide a forum for exchange of information on structural materials behaviour in primary circuit of fast breeder reactors. Special emphasis was placed on environmental effects such as influence of sodium and irradiation on mechanical properties of reactor materials

  18. A multislice theory of electron scattering in crystals including backscattering and inelastic effects.

    Science.gov (United States)

    Spiegelberg, Jakob; Rusz, Ján

    2015-12-01

    In the framework of the slice transition operator technique, a general multislice theory for electron scattering in crystals is developed. To achieve this generalization, we combine the approaches for inelastic scattering derived by Yoshioka [J. Phys. Soc. Jpn. 12, 6 (1957)] and backscattering based on the formalism of Chen and Van Dyck [Ultramicroscopy 70, 29-44 (1997)]. A computational realization of the obtained equations is suggested. The proposed computational scheme is tested on elastic backscattering of electrons, where we consider single backscattering in analogy to the computational scheme proposed by Chen and Van Dyck. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Scanning and Transmission Electron Microscopy of High Temperature Materials

    Science.gov (United States)

    1994-01-01

    Software and hardware updates to further extend the capability of the electron microscope were carried out. A range of materials such as intermetallics, metal-matrix composites, ceramic-matrix composites, ceramics and intermetallic compounds, based on refractory elements were examined under this research. Crystal structure, size, shape and volume fraction distribution of various phases which constitute the microstructures were examined. Deformed materials were studied to understand the effect of interfacial microstructure on the deformation and fracture behavior of these materials. Specimens tested for a range of mechanical property requirements, such as stress rupture, creep, low cycle fatigue, high cycle fatigue, thermomechanical fatigue, etc. were examined. Microstructural and microchemical stability of these materials exposed to simulated operating environments were investigated. The EOIM Shuttle post-flight samples were also examined to understand the influence of low gravity processing on microstructure. In addition, fractographic analyses of Nb-Zr-W, titanium aluminide, molybdenum silicide and silicon carbide samples were carried out. Extensive characterization of sapphire fibers in the fiber-reinforced composites made by powder cloth processing was made. Finally, pressure infiltration casting of metal-matrix composites was carried out.

  20. Thermal expansion model for multiphase electronic packaging materials

    International Nuclear Information System (INIS)

    Allred, B.E.; Warren, W.E.

    1991-01-01

    Control of thermal expansion is often necessary in the design and selection of electronic packages. In some instances, it is desirable to have a coefficient of thermal expansion intermediate between values readily attainable with single or two phase materials. The addition of a third phase in the form of fillers, whiskers, or fibers can be used to attain intermediate expansions. To help design the thermal expansion of multiphase materials for specific applications, a closed form model has been developed that accurately predicts the effective elastic properties of isotropic filled materials and transversely isotropic lamina. Properties of filled matrix materials are used as inputs to the lamina model to obtain the composite elastic properties as a function of the volume fraction of each phase. Hybrid composites with two or more fiber types are easily handled with this model. This paper reports that results for glass, quartz, and Kevlar fibers with beta-eucryptite filled polymer matrices show good agreement with experimental results for X, Y, and Z thermal expansion coefficients

  1. 76 FR 24051 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Mobile Tablets, Portable...

    Science.gov (United States)

    2011-04-29

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-771] In the Matter of Certain Electronic Devices...; Notice of Institution of Investigation AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on...

  2. 78 FR 32689 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-05-31

    ... INTERNATIONAL TRADE COMMISSION [Docket No 2958] Certain Portable Electronic Communications Devices... Relating to the Public Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled...

  3. 75 FR 4583 - In the Matter of: Certain Electronic Devices, Including Mobile Phones, Portable Music Players...

    Science.gov (United States)

    2010-01-28

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-701] In the Matter of: Certain Electronic Devices.... International Trade Commission. ACTION: Institution of investigation pursuant to 19 U.S.C. 1337. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on December...

  4. 78 FR 38361 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Science.gov (United States)

    2013-06-26

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-885] Certain Portable Electronic Communications... States Code AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on May 23, 2013, under section...

  5. Electron density in reasonably real metallic surfaces, including interchange and correlation effects

    International Nuclear Information System (INIS)

    Moraga, L.A.; Martinez, G.

    1981-01-01

    By means of a new method, the electron density in a jellium surface is calculated taking in account interchange and correlation effects; reproducing, in this way, the Lang and Kohn results. The new method is self-consistent but not iterative and hence is possible extend it to the solution of the same problem in more reasonably real metallic surfaces. (L.C.) [pt

  6. Si quantum dots for nano electronics: From materials to applications

    International Nuclear Information System (INIS)

    Lombardo, S.; Spinella, C.; Rimini, E.

    2005-01-01

    This paper reviews the subject of Si quantum dots embedded in dielectric and its application to the realization of non volatile semiconductor memories. In the first part of the paper various approaches for the analysis of the materials through transmission electron microscopy (TEM) are critically discussed. The advantages coming from an innovative application of energy filtered TEM are put in clear evidence. The paper then focuses on the synthesis of the materials: two different methodologies for the realization of the dots, both based on chemical vapor deposition are described in detail, and physical models providing some understanding of the observed phenomenology are reported. We then discuss the application of this nano technology to the realization of the storage nodes in non volatile semiconductor memories. The following sections describe the electrical characteristics found in the test devices and some key aspects are described in terms of quantitative models. The test devices show several performance advantages, indicating that the approach is an excellent candidate for the realization of Flash memories of the nano electronic era

  7. Flexible Organic Electronics in Biology: Materials and Devices.

    Science.gov (United States)

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-09

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Compression of pulsed electron beams for material tests

    Science.gov (United States)

    Metel, Alexander S.

    2018-03-01

    In order to strengthen the surface of machine parts and investigate behavior of their materials exposed to highly dense energy fluxes an electron gun has been developed, which produces the pulsed beams of electrons with the energy up to 300 keV and the current up to 250 A at the pulse width of 100-200 µs. Electrons are extracted into the accelerating gap from the hollow cathode glow discharge plasma through a flat or a spherical grid. The flat grid produces 16-cm-diameter beams with the density of transported per one pulse energy not exceeding 15 J·cm-2, which is not enough even for the surface hardening. The spherical grid enables compression of the beams and regulation of the energy density from 15 J·cm-2 up to 15 kJ·cm-2, thus allowing hardening, pulsed melting of the machine part surface with the further high-speed recrystallization as well as an explosive ablation of the surface layer.

  9. 75 FR 11919 - Qimonda 200 MM Facility, Including On-Site Leased Workers From Tokyo Electron America, Nikon...

    Science.gov (United States)

    2010-03-12

    ... Employment and Training Administration Qimonda 200 MM Facility, Including On-Site Leased Workers From Tokyo... 17, 2009 and December 31, 2009 to include on-site leased workers of Tokyo Electron America, Nikon... as follows: All workers of Qimonda 200MM Facility, including on-site leased workers from Tokyo...

  10. Open literature review of threats including sabotage and theft of fissile material transport in Japan

    International Nuclear Information System (INIS)

    Cochran, John Russell; Furaus, James Phillip; Marincel, Michelle K.

    2005-01-01

    This report is a review of open literature concerning threats including sabotage and theft related to fissile material transport in Japan. It is intended to aid Japanese officials in the development of a design basis threat. This threat includes the external threats of the terrorist, criminal, and extremist, and the insider threats of the disgruntled employee, the employee forced into cooperation via coercion, the psychotic employee, and the criminal employee. Examination of the external terrorist threat considers Japanese demographics, known terrorist groups in Japan, and the international relations of Japan. Demographically, Japan has a relatively homogenous population, both ethnically and religiously. Japan is a relatively peaceful nation, but its history illustrates that it is not immune to terrorism. It has a history of domestic terrorism and the open literature points to the Red Army, Aum Shinrikyo, Chukaku-Ha, and Seikijuku. Japan supports the United States in its war on terrorism and in Iraq, which may make Japan a target for both international and domestic terrorists. Crime appears to remain low in Japan; however sources note that the foreign crime rate is increasing as the number of foreign nationals in the country increases. Antinuclear groups' recent foci have been nuclear reprocessing technology, transportation of MOX fuel, and possible related nuclear proliferation issues. The insider threat is first defined by the threat of the disgruntled employee. This threat can be determined by studying the history of Japan's employment system, where Keiretsu have provided company stability and lifetime employment. Recent economic difficulties and an increase of corporate crime, due to sole reliability on the honor code, have begun to erode employee loyalty

  11. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Stéphane Guichard

    2015-12-01

    Full Text Available This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM. A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented.

  12. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  13. Adhesive flexible barrier film, method of forming same, and organic electronic device including same

    Science.gov (United States)

    Blizzard, John Donald; Weidner, William Kenneth

    2013-02-05

    An adhesive flexible barrier film comprises a substrate and a barrier layer disposed on the substrate. The barrier layer is formed from a barrier composition comprising an organosilicon compound. The adhesive flexible barrier film also comprises an adhesive layer disposed on the barrier layer and formed from an adhesive composition. A method of forming the adhesive flexible barrier film comprises the steps of disposing the barrier composition on the substrate to form the barrier layer, disposing the adhesive composition on the barrier layer to form the adhesive layer, and curing the barrier layer and the adhesive layer. The adhesive flexible barrier film may be utilized in organic electronic devices.

  14. A constitutive model for the superplastic material ALNOVI-1 including leak risk information

    NARCIS (Netherlands)

    Snippe, Corijn H.C.; Snippe, Q.H.C.; Meinders, Vincent T.; Pietzyk, M.; Kusiak, J.; Majta, J.; Hartley, P.; Lin, J.; Mori, K.

    2008-01-01

    For some applications, it is important that a formed sheet of material is completely gas tight, therefore it is beneficial to be able to predict whether a formed sheet will be leak tight for gases or not. Superplastic materials show the ability to attain very high plastic strains before failure.

  15. Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

    Science.gov (United States)

    1988-01-01

    The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

  16. Modeling and simulation of electronic structure, material interface and random doping in nano-electronic devices

    International Nuclear Information System (INIS)

    Chen Duan; Wei Guowei

    2010-01-01

    The miniaturization of nano-scale electronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), has given rise to a pressing demand in the new theoretical understanding and practical tactic for dealing with quantum mechanical effects in integrated circuits. Modeling and simulation of this class of problems have emerged as an important topic in applied and computational mathematics. This work presents mathematical models and computational algorithms for the simulation of nano-scale MOSFETs. We introduce a unified two-scale energy functional to describe the electrons and the continuum electrostatic potential of the nano-electronic device. This framework enables us to put microscopic and macroscopic descriptions in an equal footing at nano-scale. By optimization of the energy functional, we derive consistently coupled Poisson-Kohn-Sham equations. Additionally, layered structures are crucial to the electrostatic and transport properties of nano-transistors. A material interface model is proposed for more accurate description of the electrostatics governed by the Poisson equation. Finally, a new individual dopant model that utilizes the Dirac delta function is proposed to understand the random doping effect in nano-electronic devices. Two mathematical algorithms, the matched interface and boundary (MIB) method and the Dirichlet-to-Neumann mapping (DNM) technique, are introduced to improve the computational efficiency of nano-device simulations. Electronic structures are computed via subband decomposition and the transport properties, such as the I-V curves and electron density, are evaluated via the non-equilibrium Green's functions (NEGF) formalism. Two distinct device configurations, a double-gate MOSFET and a four-gate MOSFET, are considered in our three-dimensional numerical simulations. For these devices, the current fluctuation and voltage threshold lowering effect induced by the discrete dopant model are explored. Numerical convergence

  17. Determining magnetic susceptibilities of everyday materials using an electronic balance

    Science.gov (United States)

    Laumann, Daniel; Heusler, Stefan

    2017-05-01

    The magnetic properties of an object and its interaction with an external magnetic field can be described through the magnetic (volume) susceptibility χV, which divides nearly all kinds of matter into diamagnetic, paramagnetic, and ferromagnetic substances. Quantitative measurements of χV are usually technically sophisticated or require the investigation of substances with high values of χV to reveal meaningful results. Here, we show that both diamagnetic and paramagnetic effects in everyday materials can be measured using only an electronic balance and a neodymium magnet, both of which are within the reach of typical introductory college and high school physics classrooms. The experimental results match related literature values remarkably well.

  18. 75 FR 16514 - Bayer Material Science, LLC, Formally Known as Sheffield Plastics, Including On-Site Leased...

    Science.gov (United States)

    2010-04-01

    ... Employment and Training Administration Bayer Material Science, LLC, Formally Known as Sheffield Plastics... Material Science, LLC, formally known as Sheffield Plastics, including on-site leased workers from... that Bayer Material Science, LLC was formally known as Sheffield Plastics. Some workers separated from...

  19. Thermoelectric material including a multiple transition metal-doped type I clathrate crystal structure

    Science.gov (United States)

    Yang, Jihui [Lakeshore, CA; Shi, Xun [Troy, MI; Bai, Shengqiang [Shanghai, CN; Zhang, Wenqing [Shanghai, CN; Chen, Lidong [Shanghai, CN; Yang, Jiong [Shanghai, CN

    2012-01-17

    A thermoelectric material includes a multiple transition metal-doped type I clathrate crystal structure having the formula A.sub.8TM.sub.y.sub.1.sup.1TM.sub.y.sub.2.sup.2 . . . TM.sub.y.sub.n.sup.nM.sub.zX.sub.46-y.sub.1.sub.-y.sub.2.sub.- . . . -y.sub.n.sub.-z. In the formula, A is selected from the group consisting of barium, strontium, and europium; X is selected from the group consisting of silicon, germanium, and tin; M is selected from the group consisting of aluminum, gallium, and indium; TM.sup.1, TM.sup.2, and TM.sup.n are independently selected from the group consisting of 3d, 4d, and 5d transition metals; and y.sub.1, y.sub.2, y.sub.n and Z are actual compositions of TM.sup.1, TM.sup.2, TM.sup.n, and M, respectively. The actual compositions are based upon nominal compositions derived from the following equation: z=8q.sub.A-|.DELTA.q.sub.1|y.sub.1-|.DELTA.q.sub.2|y.sub.2- . . . -|.DELTA.q.sub.n|y.sub.n, wherein q.sub.A is a charge state of A, and wherein .DELTA.q.sub.1, .DELTA.q.sub.2, .DELTA.q.sub.n are, respectively, the nominal charge state of the first, second, and n-th TM.

  20. Characterization of high Tc materials and devices by electron microscopy

    National Research Council Canada - National Science Library

    Browning, Nigel D; Pennycook, Stephen J

    2000-01-01

    ..., and microanalysis by scanning transmission electron microscopy. Ensuing chapters examine identi®cation of new superconducting compounds, imaging of superconducting properties by lowtemperature scanning electron microscopy, imaging of vortices by electron holography and electronic structure determination by electron energy loss spectro...

  1. Electronic structure and relaxation dynamics in a superconducting topological material.

    Science.gov (United States)

    Neupane, Madhab; Ishida, Yukiaki; Sankar, Raman; Zhu, Jian-Xin; Sanchez, Daniel S; Belopolski, Ilya; Xu, Su-Yang; Alidoust, Nasser; Hosen, M Mofazzel; Shin, Shik; Chou, Fangcheng; Hasan, M Zahid; Durakiewicz, Tomasz

    2016-03-03

    Topological superconductors host new states of quantum matter which show a pairing gap in the bulk and gapless surface states providing a platform to realize Majorana fermions. Recently, alkaline-earth metal Sr intercalated Bi2Se3 has been reported to show superconductivity with a Tc ~ 3 K and a large shielding fraction. Here we report systematic normal state electronic structure studies of Sr0.06Bi2Se3 (Tc ~ 2.5 K) by performing photoemission spectroscopy. Using angle-resolved photoemission spectroscopy (ARPES), we observe a quantum well confined two-dimensional (2D) state coexisting with a topological surface state in Sr0.06Bi2Se3. Furthermore, our time-resolved ARPES reveals the relaxation dynamics showing different decay mechanism between the excited topological surface states and the two-dimensional states. Our experimental observation is understood by considering the intra-band scattering for topological surface states and an additional electron phonon scattering for the 2D states, which is responsible for the superconductivity. Our first-principles calculations agree with the more effective scattering and a shorter lifetime of the 2D states. Our results will be helpful in understanding low temperature superconducting states of these topological materials.

  2. Compositions of graphene materials with metal nanostructures and microstructures and methods of making and using including pressure sensors

    KAUST Repository

    Chen, Ye

    2017-01-26

    Composition comprising at least one graphene material and at least one metal. The metal can be in the form of nanoparticles as well as microflakes, including single crystal microflakes. The metal can be intercalated in the graphene sheets. The composition has high conductivity and flexibility. The composition can be made by a one-pot synthesis in which a graphene material precursor is converted to the graphene material, and the metal precursor is converted to the metal. A reducing solvent or dispersant such as NMP can be used. Devices made from the composition include a pressure sensor which has high sensitivity. Two two- dimension materials can be combined to form a hybrid material.

  3. Discrete Material and Thickness Optimization of laminated composite structures including failure criteria

    DEFF Research Database (Denmark)

    Lund, Erik

    2017-01-01

    This work extends the Discrete Material and Thickness Optimization approach to structural optimization problems where strength considerations in the form of failure criteria are taken into account for laminated composite structures. It takes offset in the density approaches applied for stress...... constrained topology optimization of single-material problems and develops formulations for multi-material topology optimization problems applied for laminated composite structures. The method can be applied for both stress- and strain-based failure criteria. The large number of local constraints is reduced...

  4. Modeling electronic structure and spectroscopy in correlated materials and topological insulators

    Science.gov (United States)

    Wang, Yung Jui

    Current major topics in condensed matter physics mostly focus on the investigation of materials having exotic quantum phases. For instance, Z 2 topological insulators have novel quantum states, which are distinct from ordinary band insulators. Recent developments show that these nontrivial topological phases may provide a platform for creating new types of quasiparticles in real materials, such as Majorana fermions. In correlated systems, high-T c superconducting cuprates are complicated due to the richness of their phase diagram. Surprisingly, the discovery of iron pnictides demonstrates that high-Tc superconductivity related phenomena are not unique to copper oxide compounds. Many people believe that the better the understanding of the electronic structure of cuprates and iron pnictides, the higher chances to unveil the high temperature superconductivity mystery. Despite the fact that silicon is a fundamental element in modern semiconductor electronics technology, the chemical bonding properties of liquid silicon phase still remain a puzzle. A popular approach to investigate electronic structure of complex materials is combining the first principles calculation with an experimental light scattering probe. Particularly, Compton scattering probes the many body electronic ground state in the bulk of materials in terms of electron momentum density projected along a certain scattering direction, and inelastic x-ray scattering measures the dynamic structure factor S(q, o) which contains information about electronic density-density correlations. In this thesis, I study several selected materials based on first principles calculations of their electronic structures, the Compton profiles and the Lindhard susceptibility within the framework of density functional theory. Specifically, I will discuss the prediction of a new type of topological insulators in quaternary chalcogenide compounds of compositions I2-II-IV-VI 4 and in ternary famatinite compounds of compositions I3

  5. Metal and silicate particles including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol.

    Directory of Open Access Journals (Sweden)

    Monique Williams

    Full Text Available Electronic cigarettes (EC deliver aerosol by heating fluid containing nicotine. Cartomizer EC combine the fluid chamber and heating element in a single unit. Because EC do not burn tobacco, they may be safer than conventional cigarettes. Their use is rapidly increasing worldwide with little prior testing of their aerosol.We tested the hypothesis that EC aerosol contains metals derived from various components in EC.Cartomizer contents and aerosols were analyzed using light and electron microscopy, cytotoxicity testing, x-ray microanalysis, particle counting, and inductively coupled plasma optical emission spectrometry.The filament, a nickel-chromium wire, was coupled to a thicker copper wire coated with silver. The silver coating was sometimes missing. Four tin solder joints attached the wires to each other and coupled the copper/silver wire to the air tube and mouthpiece. All cartomizers had evidence of use before packaging (burn spots on the fibers and electrophoretic movement of fluid in the fibers. Fibers in two cartomizers had green deposits that contained copper. Centrifugation of the fibers produced large pellets containing tin. Tin particles and tin whiskers were identified in cartridge fluid and outer fibers. Cartomizer fluid with tin particles was cytotoxic in assays using human pulmonary fibroblasts. The aerosol contained particles >1 µm comprised of tin, silver, iron, nickel, aluminum, and silicate and nanoparticles (<100 nm of tin, chromium and nickel. The concentrations of nine of eleven elements in EC aerosol were higher than or equal to the corresponding concentrations in conventional cigarette smoke. Many of the elements identified in EC aerosol are known to cause respiratory distress and disease.The presence of metal and silicate particles in cartomizer aerosol demonstrates the need for improved quality control in EC design and manufacture and studies on how EC aerosol impacts the health of users and bystanders.

  6. Photon-Electron Interactions in Dirac Quantum Materials

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaodong [Univ. of Washington, Seattle, WA (United States). Dept. of Material Science and Engineering

    2017-11-10

    The objective of this proposal was to explore the fundamental light-matter interactions in a new class of Dirac quantum materials, atomically thin transition metal dichalcogenides (TMDs). Monolayer TMDs are newly discovered two-dimensional semiconductors with direct bandgap. Due to their hexagonal lattice structure, the band edge localizes at corner of Brillouin zone, i.e. “Dirac valleys”. This gives the corresponding electron states a “valley index” (or pseudospin) in addition to the real spin. Remarkably, the valley pseudospins have circularly polarized optical selection rules, providing the first solid state system for dynamic control of the valley degree of freedom. During this award, we have developed a suite of advanced nano-optical spectroscopy tools in the investigation and manipulation of charge, spin, and valley degrees of freedom in monolayer semiconductors. Emerging physical phenomena, such as quantum coherence between valley pseudospins, have been demonstrated for the first time in solids. In addition to monolayers, we have developed a framework in engineering, formulating, and understanding valley pseudospin physics in 2D heterostructures formed by different monolayer semiconductors. We demonstrated long-lived valley-polarized interlayer excitons with valley-dependent many-body interaction effects. These works push the research frontier in understanding the light-matter interactions in atomically-thin quantum materials for protentional transformative energy technologies.

  7. Determination of trace elements in electronic materials by NAA

    International Nuclear Information System (INIS)

    Kobayashi, Kenji

    1986-01-01

    Trace amounts of elements in electronic materials were determined by instrumental neutron activation analysis (INAA), re-activation analysis and substoichiometric radioactivation analysis using gamma-ray spectrometry. Ten elements (Cr, Cu, Fe, Zn, Co, Eu, Ir, Sb, Sc, Tb) in gallium arsenide single crystal were determined by INAA and substoichiometric radioactivation analysis. Trace level of chromium (10 13 atoms/cm 3 ) and zinc (10 14 atoms/cm 3 ) in gallium arsenide single crystal were determined by INAA. The chromium concentrations in horizontal Bridgmangrown semi-insulating gallium arsenide ingot were ranged from 1.2 x 10 16 atoms/cm 3 at seed end to 3.5 x 10 16 atoms/cm 3 at tail end. The trace determinations of iron (10 14 atoms/cm 3 ) and copper (10 14 atoms/cm 3 ) in silicon, gallium arsenide and indium phoshide single crystals were carried out by substoichiometric radioactivation analysis. The reactivation analysis for the multielement determination of indium phosphide single crystal was carried out and nineteen elements were determined simultaneously by gamma-ray spectrometry. Eleven elements (Ag, As, Br, Co, Cr, Fe, K, Mn, Sb, Sc, Zn) in four NIES standard reference materials (Pond Sediment, Chlorella, Mussel and Tea Leaves) and seven elements (Co, Cr, Eu, Fe, Sc, Tb, Yb) in two NBS glasses (SRM-615 and SRM-613) were determined by INAA and substoichiometric radioactivation analysis and the analytical results obtained by the methods were in good agreement with certified values by NIES and NBS. (author)

  8. Method of extruding and packaging a thin sample of reactive material including forming the extrusion die

    International Nuclear Information System (INIS)

    Lewandowski, E.F.; Peterson, L.L.

    1985-01-01

    This invention teaches a method of cutting a narrow slot in an extrusion die with an electrical discharge machine by first drilling spaced holes at the ends of where the slot will be, whereby the oil can flow through the holes and slot to flush the material eroded away as the slot is being cut. The invention further teaches a method of extruding a very thin ribbon of solid highly reactive material such as lithium or sodium through the die in an inert atmosphere of nitrogen, argon or the like as in a glovebox. The invention further teaches a method of stamping out sample discs from the ribbon and of packaging each disc by sandwiching it between two aluminum sheets and cold welding the sheets together along an annular seam beyond the outer periphery of the disc. This provides a sample of high purity reactive material that can have a long shelf life

  9. New electron-ion-plasma equipment for modification of materials and products surface

    International Nuclear Information System (INIS)

    Koval', N.N.

    2013-01-01

    Electron-ion-plasma treatment of materials and products, including surface clearing and activation, formation surface layers with changed chemical and phase structure, increased hardness and corrosion resistance; deposition of various functional coatings, has received a wide distribution in a science and industry. Widespread methods of ion-plasma modification of material and product surfaces are ion etching and activation, ion-plasma nitriding, arc or magnetron deposition of functional coatings, including nanostructured. The combination of above methods of surface modification allows essentially to improve exploitation properties of treated products and to optimize the characteristics of modified surfaces for concrete final requirements. For the purpose of a combination of various methods of ion-plasma treatment in a single work cycle at Institute of High Current Electronics of SB RAS (IHCE SB RAS) specialized technological equipment 'DUET', 'TRIO' and 'QUADRO' and 'KVINTA' have been developed. This equipment allow generating uniform low-temperature gas plasma at pressures of (0.1-1) Pa with concentration of (10 9 -10 11 ) cm -3 in volume of (0.1-1) m 3 . In the installations consistent realization of several various operations of materials and products treatment in a single work cycle is possible. The operations are preliminary heating and degassing, ion clearing, etching and activation of materials and products surface by plasma of arc discharges; chemicothermal treatment (nitriding) for formation of diffusion layer on a surface of treated sample using plasma of nonself-sustained low-pressure arc discharge; deposition of single- or multilayered superhard (≥40 GPa) nanocrystalline coatings on the basis of pure metals or their compounds (nitrides, carbides, carbonitrides) by the arc plasma-assisted method. For realization of the modes all installations are equipped by original sources of gas and metal plasma. Besides, in

  10. Environmental transmission electron microscopy for catalyst materials using a spherical aberration corrector

    International Nuclear Information System (INIS)

    Takeda, Seiji; Kuwauchi, Yasufumi; Yoshida, Hideto

    2015-01-01

    Atomic resolution has been obtained using environmental transmission electron microscopy (ETEM) by installing a spherical aberration corrector (Cs-corrector) on the objective lens. Simultaneously, the technology for controlling the environment around a specimen in ETEM has advanced significantly in the past decade. Quantification methodology has recently been established for deriving relevant experimental data in catalyst materials from substantial and systematic ETEM observation at the atomic scale. With this background, this paper summarizes aspects of the evolutional microscopy technique: necessary conditions for atomic resolution in ETEM; reduction of the scattering of electrons by the medium surrounding a specimen; and an environmental cell for structural imaging of a crystalline specimen. The high spatial resolution of a Cs-corrected ETEM is demonstrated for different observation conditions. After statistical analysis combined with numerical image analysis of ETEM data is briefly described, the recent applications of the Cs-corrected ETEM to catalyst materials are reviewed. For gold nanoparticulate catalysts, the structural information on the reaction sites and adsorption sites are deduced. For Pt nanoparticulate catalysts, ETEM studies elucidate the correlation between the catalytic activity and the morphology of the nanoparticles. These studies also reveal oxidation and reduction on the topmost Pt surface layer at the atomic scale. Finally, current issues and the future perspectives of Cs-corrected ETEM are summarized, including the reproducibility of ETEM observation data, the control of environments, the critical evaluation of electron irradiation effects, the full implementation of transmission electron microscopy technology in ETEM, and the safety issues for an ETEM laboratory. - Highlights: • Advancement of Cs corrected environmental transmission electron microscopy. • Structural determination of catalyst materials in reaction environments.

  11. 78 FR 18457 - Definition of Form I-94 To Include Electronic Format

    Science.gov (United States)

    2013-03-27

    ... alien to turn in the departure portion of the Form I-94 at the time of departure, the definition..., and 286 [USCBP-2013-0011; CBP Dec. No. 13-06] RIN 1651-AA96 Definition of Form I-94 To Include... departure. DHS generally issues the Form I-94 to aliens at the time they lawfully enter the United States...

  12. Ballistic electron channels including weakly protected topological states in delaminated bilayer graphene

    Science.gov (United States)

    Lane, T. L. M.; Andelković, M.; Wallbank, J. R.; Covaci, L.; Peeters, F. M.; Fal'ko, V. I.

    2018-01-01

    We show that delaminations in bilayer graphene (BLG) with electrostatically induced interlayer symmetry can provide one with ballistic channels for electrons with energies inside the electrostatically induced BLG gap. These channels are formed by a combination of valley-polarized evanescent states propagating along the delamination edges (which persist in the presence of a strong magnetic field) and standing waves bouncing between them inside the delaminated region (in a strong magnetic field, these transform into Landau levels in the monolayers). For inverted stackings in BLGs on the left and right of the delamination (AB-2ML-BA or BA-2ML-AB, where 2ML indicates two decoupled monolayers of graphene), the lowest-energy ballistic channels are gapless, have linear dispersion, and appear to be weakly topologically protected. When BLG stackings on both sides of the delamination are the same (AB-2ML-AB or BA-2ML-BA), the lowest-energy ballistic channels are gapped, with a gap ɛg scaling as ɛg∝W-1 with delamination width and ɛg∝δ-1 with the on-layer energy difference in the delaminated part of the structure. Depending on the width, delaminations may also support several "higher-energy" waveguide modes. Our results are based on both the analytical study of the wave matching of Dirac states and tight-binding model calculations, and we analyze in detail the dependence of the delamination spectrum on the electrostatic conditions in the structure, such as the vertical displacement field.

  13. Electronic and Thermal Properties of Puckered Orthorhombic Materials

    Science.gov (United States)

    Fei, Ruixiang

    Puckered orthorhombic crystals, such as black phosphorus and group IV monochalcogenides, are attracting tremendous attention because of their new exotic properties, which are of great interests for fundamental science and novel applications. Unlike those well studied layered hexagonal materials such as graphene and transition metal dichalcogenides, the puckered orthorhombic crystals possess highly asymmetrical in-plane crystal structures. Understanding the unique properties emerginge from their low symmetries is an intriguing and useful process, which gives insight into experimental observation and sheds light on manipulating their properties. In this thesis, we study and predict various properties of orthorhombic materials by using appropriate theoretical techniques such as first-principles calculations, Monte-Carlo simulations, and k · p models. In the first part of the thesis, we deal with the anisotropic electric and thermal properties of a typical puckered orthorhombic crystal, black phosphorus. We first study the electric properties in monolayer and few-layer black phosphorus, where the unique, anisotropic electrical conductance is founded. Furthermore, we find that the anisotropy of the electrical conductance can be rotated by 90° through applying appropriate uniaxial or biaxial strain. Beyond electrical conductance, we, for the first time, predict that the thermal conductance of black phosphorus is also anisotropic and, particularly, the preferred conducting direction is perpendicular to the preferred electrical conducting direction. Within the reasonable estimation regime, the thermoelectric figure of merit (ZT) ultimately reaches 1 at room temperature using only moderate doping. The second part of this thesis focuses on the electronic polarization of non-centrosymmetric puckered materials-group IV monochalcogenide. We propose that monolayer group IV monochalcogenides are a new class of two-dimensional (2D) ferroelectric materials with spontaneous in

  14. Recharacterization of Rhinophis dorsimaculatus Deraniyagala, 1941 (Serpentes: Uropeltidae), including description of new material.

    Science.gov (United States)

    Gower, David J; Wickramasinghe, L J Mendis

    2016-08-29

    The Sri Lankan uropeltid (shieldtail) snake Rhinophis dorsimaculatus Deraniyagala, 1941 was described originally from two specimens that were subsequently lost. The small amount of previously published data and lack of published colour photographs made this one of South Asia's most poorly known snake species, and this resulted in at least one instance of taxonomic misidentification. An additional 10 specimens from a historical collection from the vicinity of the type locality recently came to light. This material is reviewed and documented and the species recharacterized. An additional locality for the species is reported. The newly reported material helps to corroborate the taxonomic validity and distinctiveness of Rhinophis dorsimaculatus. The species is readily distinguished from congeners by having 227 or more ventral scales; a large, dorsally carinate rostral shield; posterior margins of paired anals that are largely separated by the posteriormost ventral scale; and a distinctive colour pattern with bilaterally asymmetrical dark blotches within a broad, pale middorsal stripe and regularly punctate flanks.

  15. Monte Carlo simulation of electron thermalization in scintillator materials: Implications for scintillator nonproportionality

    Science.gov (United States)

    Prange, Micah P.; Xie, YuLong; Campbell, Luke W.; Gao, Fei; Kerisit, Sebastien

    2017-12-01

    The lack of reliable quantitative estimates of the length and time scales associated with hot electron thermalization after a gamma-ray induced energy cascade obscures the interplay of various microscopic processes controlling scintillator performance and hampers the search for improved detector materials. We apply a detailed microscopic kinetic Monte Carlo model of the creation and subsequent thermalization of hot electrons produced by gamma irradiation of six important scintillating crystals to determine the spatial extent of the cloud of excitations produced by gamma rays and the time required for the cloud to thermalize with the host lattice. The main ingredients of the model are ensembles of microscopic track structures produced upon gamma excitation (including the energy distribution of the excited carriers), numerical estimates of electron-phonon scattering rates, and a calculated particle dispersion to relate the speed and energy of excited carriers. All these ingredients are based on first-principles density functional theory calculations of the electronic and phonon band structures of the materials. The details of the Monte Carlo model are presented along with the results for thermalization time and distance distributions. These results are discussed in light of previous work. It is found that among the studied materials, calculated thermalization distances are positively correlated with measured nonproportionality. In the important class of halide scintillators, the particle dispersion is found to be more influential than the largest phonon energy in determining the thermalization distance.

  16. Monte Carlo simulation of electron thermalization in scintillator materials: Implications for scintillator nonproportionality

    Energy Technology Data Exchange (ETDEWEB)

    Prange, Micah P. [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Xie, YuLong [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Campbell, Luke W. [National Security Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Gao, Fei [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA; Kerisit, Sebastien [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA

    2017-12-21

    The lack of reliable quantitative estimates of the length and time scales associated with hot electron thermalization after a gamma-ray induced energy cascade obscures the interplay of various microscopic processes controlling scintillator performance and hampers the search for improved detector materials. We apply a detailed microscopic kinetic Monte Carlo model of the creation and subsequent thermalization of hot electrons produced by gamma irradiation of six important scintillating crystals to determine the spatial extent of the cloud of excitations produced by gamma rays and the time required for the cloud to thermalize with the host lattice. The main ingredients of the model are ensembles of microscopic track structures produced upon gamma excitation (including the energy distribution of the excited carriers), numerical estimates of electron-phonon scattering rates, and a calculated particle dispersion to relate the speed and energy of excited carriers. All these ingredients are based on first-principles density functional theory calculations of the electronic and phonon band structures of the materials. Details of the Monte Carlo model are presented along with results for thermalization time and distance distributions. These results are discussed in light of previous work. It is found that among the studied materials, calculated thermalization distances are positively correlated with measured nonproportionality. In the important class of halide scintillators, the particle dispersion is found to be more influential than the largest phonon energy in determining the thermalization distance.

  17. Results of a Saxitoxin Proficiency Test Including Characterization of Reference Material and Stability Studies

    Directory of Open Access Journals (Sweden)

    Kirsi Harju

    2015-11-01

    Full Text Available A saxitoxin (STX proficiency test (PT was organized as part of the Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk (EQuATox project. The aim of this PT was to provide an evaluation of existing methods and the European laboratories’ capabilities for the analysis of STX and some of its analogues in real samples. Homogenized mussel material and algal cell materials containing paralytic shellfish poisoning (PSP toxins were produced as reference sample matrices. The reference material was characterized using various analytical methods. Acidified algal extract samples at two concentration levels were prepared from a bulk culture of PSP toxins producing dinoflagellate Alexandrium ostenfeldii. The homogeneity and stability of the prepared PT samples were studied and found to be fit-for-purpose. Thereafter, eight STX PT samples were sent to ten participating laboratories from eight countries. The PT offered the participating laboratories the possibility to assess their performance regarding the qualitative and quantitative detection of PSP toxins. Various techniques such as official Association of Official Analytical Chemists (AOAC methods, immunoassays, and liquid chromatography-mass spectrometry were used for sample analyses.

  18. Electronic transport in amorphous phase-change materials

    International Nuclear Information System (INIS)

    Luckas, Jennifer Maria

    2012-01-01

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  19. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  20. Mechanical experiments on the superplastic material ALNOVI-1, including leak information

    Energy Technology Data Exchange (ETDEWEB)

    Snippe, Q.H.C., E-mail: csnippe@nikhef.nl; Meinders, T.

    2011-01-25

    Research highlights: {yields} Mechanical testing of superplastic materials, in particular ALNOVI-1. {yields} Uniaxial tests to show the one-dimensional stress-strain behaviour and the high amount of strain rate sensitivity. {yields} Void volume fractions have been observed. {yields} Free bulge experiments to show the dependence on the backpressure during the forming stage. {yields} Measuring leak tightness of superplastically formed sheets. {yields} Experiments are used in order to develop a constitutive model in a later stage. - Abstract: In subatomic particle physics, unstable particles can be detected with a so-called vertex detector, placed inside a particle accelerator. A detecting unit close to the accelerator bunch of charged particles must be separated from the accelerator vacuum. A thin sheet with a complex 3D shape prevents the detector vacuum from polluting the accelerator vacuum. Therefore, this sheet has to be completely leak tight. However, this can conflict with restrictions concerning maximum sheet thickness of the product. To produce such a complex thin sheet, superplastic forming can be very attractive in cases where a small number of products is needed. In order to predict gas permeability of these formed sheets, many mechanical experiments are necessary, where the gas leak has to be measured. To obtain insight in the mechanical behaviour of the used material, ALNOVI-1, tensile experiments were performed to describe the uniaxial stress-strain behaviour. From these experiments, a high strain rate sensitivity was measured. The flow stress of this material under superplastic conditions was low and the material behaved in an isotropic manner upon large plastic strains. The results of these experiments were used to predict the forming pressure as a function of time in a free bulge experiment, such that a predefined target strain rate will not be exceeded in the material. An extra parameter within these bulging experiments is the application of a

  1. 76 FR 40930 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and...

    Science.gov (United States)

    2011-07-12

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-701] In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and Computers; Notice of Commission... music players, and computers by reason of infringement of various claims of United States Patent Nos. 6...

  2. Model of spur processes in aqueous radiation chemistry including spur overlap and a novel initial hydrated electron distribution

    International Nuclear Information System (INIS)

    Short, D.R.

    1980-01-01

    Results are presented from computer calculations based upon an improved diffusion-kinetic model of the spur which includes a novel initial distribution for the hydrated electron and an approximate mathematical treatment of the overlap of spurs in three dimensions. Experimental data for the decay of the hydrated electron and hydroxyl radical before one in electron-pulse-irradated, solute-free and air-free water are fit wihtin experimental uncertainty by adjustment of the initial spatial distributions of spur intermediates and the average energy deposited in the spur. Using the same values of these parameters, the hydrated electron decay is computed for times from 1 ps 10 μs after the radiatio pulse. The results of such calcuations for various conditions of pulse dose and concentrations of scavengers of individual primary chemical species in the spur are compared with corresponding experimental data obtained predominantly from water and aqueous solutions irradiated with 10 to 15 MeV electron pulses. Very good agreement between calculated and experimental hydrated electron decay in pure water is observed for the entire time range studied when a pulse dose of approximately 7900 rads is modeled, but the calcuated and experimental curves are observed to deviate for times greater than 10 ns nanoseconds when low pulse doses and low scavenger concentrations are considered. It is shown that this deviation is experimental and calculated hydrated electron decay cannot be explained by assuming the presence of a hydrated electron scavenging impurity nor by employing a distribution of nearest neighbor interspur distances to refine the overlap approximation

  3. In situ studies of the electronic and vibrational properties of thin films and novel materials

    Science.gov (United States)

    Fox, Jon Raymond

    The electronic and vibrational properties of several novel materials were investigated in an in situ ultra high vacuum (UHV) environment. The novel materials included thin films of laser-modified fullerenes, believed to be photopolymerized; rubidium fulleride, a fullerene polymer in a slow-cooled phase; the zinc selenide (100) surface which reconstructs into (2 x 1) and c(2 x 2) forms; and silicon nanoparticles which exhibit size-dependent effects. Interference enhanced Raman scattering (IERS) and high resolution electron energy loss spectroscopy (HREELS) in reflection were employed to study the vibrational spectra of the materials. Ultraviolet photoemission spectroscopy (UPS) and electron energy loss spectroscopy (EELS) provided spectral information related to the electronic states of these systems. Ultra-thin layers of silicon were grown by dc magnetron sputtering in ultra high vacuum on amorphous MgO and Ag buffer layers. The average thickness of the layers ranged from monolayer coverage to 200 angstroms. Transmission electron microscopy (TEM) has been used to determine the size and shape of the silicon nanoparticles. Changes in the crystallization process have been studied by interference enhanced Raman scattering (IERS). Marked size dependences in the phonon spectra of amorphous silicon nanoparticles were detected. A relaxation of the k-vector conservation condition occurs in silicon nanocrystals as they decrease in size. The nanocrystal transition between crystalline-like and amorphous-like behavior takes place films with average thickness less than or equal to 10 angstroms. TEM micrographs indicate that the silicon nanoparticles exhibiting this transition have an average number of silicon atoms equal to 700 (+/-200). The electronic spectra as measured by EELS continue to be differentiable even at considerably thinner coverages.

  4. Three Peaks of 2011 Draconid Activity Including that Connected with Pre-1900 Material

    Science.gov (United States)

    Koten, Pavel; Vaubaillon, Jeremie; Tóth, Juraj; Margonis, Anastasios; Ďuriš, František

    2014-08-01

    A Draconid meteor shower outburst was observed from on board two scientific aircraft deployed above Northern Europe on 8th October 2011. The activity profile was measured using a set of photographic and video cameras. The main peak of the activity occurred around 20:15 ± 0:0.5 UT which is consistent with the model prediction as well as with the IMO network visual observations. The corrected hourly rates reached a value of almost 350. The brighter meteors peaked about 15-20 min earlier than the dimmer ones. This difference can be explained by different directions of the ejection of the meteoroids from the parent comet. One of the instruments was even able to detect meteors connected with the material ejected from the parent comet before 1900 and thus confirmed the prediction of the model, although it was based on uncertain pre-1900 cometary data. Another small peak of the activity, which was caused by material ejected during the 1926 perihelion passage of the parent comet, was detected around 21:10 UT. The mass distribution index determined using the narrow field-of-view video camera was 2.0 ± 0.1. This work shows that the observation of meteor outbursts can constrain the orbital elements, outgassing activity and existence of jets at the surface of a comet.

  5. Development of microwave absorbing materials prepared from a polymer binder including Japanese lacquer and epoxy resin

    Science.gov (United States)

    Iwamaru, T.; Katsumata, H.; Uekusa, S.; Ooyagi, H.; Ishimura, T.; Miyakoshi, T.

    Microwave absorption composites were synthesized from a poly urushiol epoxy resin (PUE) mixed with one of microwave absorbing materials; Ni-Zn ferrite, Soot, Black lead, and carbon nano tube (CNT) to investigate their microwave absorption properties. PUE binders were specially made from Japanese lacquer and epoxy resin, where Japanese lacquer has been traditionally used for bond and paint because it has excellent beauty. Japanese lacquer solidifies with oxygen contained in air's moisture, which has difficulty in making composite, but we improved Japanese lacquer's solidification properties by use of epoxy resin. We made 10 mm thickness composite samples and cut them into toroidal shape to measure permittivity, permeability, and reflection loss in frequencies ranging from 50 Hz to 20 GHz. Electric magnetic absorber's composites synthesized from a PUE binders mixed either with Soot or CNT showed significantly higher wave absorption over -27 dB than the others at frequencies around 18 GHz, although Japanese lacquer itself doesn't affect absorption. This means Japanese lacquer can be used as binder materials for microwave absorbers.

  6. Purchase of a Raman and Photoluminescence Imaging System for Characterization of Advanced Electrochemical and Electronic Materials

    Science.gov (United States)

    2016-01-05

    and bulk). The instrument supports advanced interdisciplinary research ( chemistry , materials science, electronics and physics ) in the department... Chemistry /Instrumental Analysis (20-30 undergraduate students per year). (a) Papers published in peer-reviewed journals (N/A for none) Enter List of...material (surface and bulk). The instrument supports advanced interdisciplinary research ( chemistry , materials science, electronics and physics ) in

  7. Electronic and magnetic interactions in high temperature superconducting and high coercivity materials. Final performance report

    International Nuclear Information System (INIS)

    Cooper, B.R.

    1997-01-01

    The issue addressed in the research was how to understand what controls the competition between two types of phase transition (ordering) which may be present in a hybridizing correlated-electron system containing two transition-shell atomic species; and how the variation of behavior observed can be used to understand the mechanisms giving the observed ordered state. This is significant for understanding mechanisms of high-temperature superconductivity and other states of highly correlated electron systems. Thus the research pertains to magnetic effects as related to interactions giving high temperature superconductivity; where the working hypothesis is that the essential feature governing the magnetic and superconducting behavior of copper-oxide-type systems is a cooperative valence fluctuation mechanism involving the copper ions, as mediated through hybridization effects dominated by the oxygen p electrons. (Substitution of praseodymium at the rare earth sites in the 1·2·3 material provides an interesting illustration of this mechanism since experimentally such substitution strongly suppresses and destroys the superconductivity; and, at 100% Pr, gives Pr f-electron magnetic ordering at a temperature above 16K). The research was theoretical and computational and involved use of techniques aimed at correlated-electron systems that can be described within the confines of model hamiltonians such as the Anderson lattice hamiltonian. Specific techniques used included slave boson methodology used to treat modification of electronic structure and the Mori projection operator (memory function) method used to treat magnetic response (dynamic susceptibility)

  8. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    International Nuclear Information System (INIS)

    Farley, David R.

    2010-01-01

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N (ge) 3, with a rotational temperature between the wall and feed gas temperatures. The N = 0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  9. Using Electronic Neutron Generators in Active Interrogation to Detect Shielded Fissionable Material

    Science.gov (United States)

    Chichester, David L.; Seabury, Edward H.

    2009-04-01

    Experiments have been performed at Idaho National Laboratory to study methodology and instrumentation for performing neutron active interrogation die-away analyses for the purpose of detecting shielded fissionable material. Here we report initial work using a portable DT electronic neutron generator with a 3He neutron detector to detect shielded fissionable material including enriched uranium and reactor grade plutonium. Measurements have been taken of bare material as well as of material hidden within a large plywood cube. Results from this work have demonstrated the efficacy of the die-away neutron measurement technique for quickly detecting the presence of special nuclear material hidden within plywood shields by analyzing the time dependent neutron signals in-between neutron generator pulses. Using a DT electronic neutron generator operating at 300 Hz with a yield of approximately 0.36 times 108 neutrons per second, 2.2 kg of enriched uranium hidden within a 61 cm times 61 cm times 71 cm volume of plywood was positively detected with a measurement signal 2-sigma above the passive background within 1 second. Similarly, for a 500 second measurement period a lower detection limit approaching the gram level could be expected with the same simple set-up.

  10. Advances in imaging and electron physics time resolved electron diffraction for chemistry, biology and material science

    CERN Document Server

    Hawkes, Peter W

    2014-01-01

    Advances in Imaging & Electron Physics merges two long-running serials-Advances in Electronics & Electron Physics and Advances in Optical & Electron Microscopy. The series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Contributions from leading authorities Informs and updates on all the latest developments in the field.

  11. Fast three-material modeling with triple arch projection for electronic cleansing in CTC.

    Science.gov (United States)

    Lee, Hyunna; Lee, Jeongjin; Kim, Bohyoung; Kim, Se Hyung; Shin, Yeong-Gil

    2014-07-01

    In this paper, we propose a fast three-material modeling for electronic cleansing (EC) in computed tomographic colonography. Using a triple arch projection, our three-material modeling provides a very quick estimate of the three-material fractions to remove ridge-shaped artifacts at the T-junctions where air, soft-tissue (ST), and tagged residues (TRs) meet simultaneously. In our approach, colonic components including air, TR, the layer between air and TR, the layer between ST and TR (L(ST/TR)), and the T-junction are first segmented. Subsequently, the material fraction of ST for each voxel in L(ST/TR) and the T-junction is determined. Two-material fractions of the voxels in L(ST/TR) are derived based on a two-material transition model. On the other hand, three-material fractions of the voxels in the T-junction are estimated based on our fast three-material modeling with triple arch projection. Finally, the CT density value of each voxel is updated based on our fold-preserving reconstruction model. Experimental results using ten clinical datasets demonstrate that the proposed three-material modeling successfully removed the T-junction artifacts and clearly reconstructed the whole colon surface while preserving the submerged folds well. Furthermore, compared with the previous three-material transition model, the proposed three-material modeling resulted in about a five-fold increase in speed with the better preservation of submerged folds and the similar level of cleansing quality in T-junction regions.

  12. Electronic structures and spectroscopic properties of CdI: MRCI+Q study including spin-orbit coupling

    Science.gov (United States)

    Li, Rui; Zhang, Hua; Liu, Xiaohua; Zhao, Shutao; Liu, Yadong; Yan, Bing

    2018-01-01

    Cadmium iodide (CdI), which is a candidate for laser material in chemical lasing, has attracted considerable scientific interest. While the complete picture for electronic structure of CdI is still unclear, particularly for the interactions of excited states. In this paper, high-level configuration interaction method is applied to compute the low-lying electronic states of the lowest two dissociation limits (Cd(1S) + I(2P) and Cd(3P) + I(2P)). To ensure the accuracy, the Davidson correction, core-valence electronic correlations and spin-orbit coupling effects are also taken into account. The potential energy curves of the 14 Λ-S states and 30 Ω states obtained from those Λ-S states are calculated. On the basis of the computed potential energy curves, the spectroscopic constants of bound and quasibound states are determined, most of which have not been reported in existing studies. The calculated values of spin-orbit coupling matrix elements demonstrate that the B2Σ+1/2 state imposes a strong perturbation on ν‧> 0 vibrational level of C2Π1/2, which can explain the weak spectral intensity of C2Π1/2-X2Σ+1/2 observed in previous experiment. The transition dipole moments as well as the lifetimes are evaluated to predict the transition properties of B2Σ+1/2, C2Π1/2 and 22Π3/2 states.

  13. Electric fields, weighting fields, signals and charge diffusion in detectors including resistive materials

    International Nuclear Information System (INIS)

    Riegler, W.

    2016-01-01

    In this report we discuss static and time dependent electric fields in detector geometries with an arbitrary number of parallel layers of a given permittivity and weak conductivity. We derive the Green's functions i.e. the field of a point charge, as well as the weighting fields for readout pads and readout strips in these geometries. The effect of 'bulk' resistivity on electric fields and signals is investigated. The spreading of charge on thin resistive layers is also discussed in detail, and the conditions for allowing the effect to be described by the diffusion equation is discussed. We apply the results to derive fields and induced signals in Resistive Plate Chambers, MICROMEGAS detectors including resistive layers for charge spreading and discharge protection as well as detectors using resistive charge division readout like the MicroCAT detector. We also discuss in detail how resistive layers affect signal shapes and increase crosstalk between readout electrodes.

  14. Method for contamination control and barrier apparatus with filter for containing waste materials that include dangerous particulate matter

    Science.gov (United States)

    Pinson, Paul A.

    1998-01-01

    A container for hazardous waste materials that includes air or other gas carrying dangerous particulate matter has incorporated in barrier material, preferably in the form of a flexible sheet, one or more filters for the dangerous particulate matter sealably attached to such barrier material. The filter is preferably a HEPA type filter and is preferably chemically bonded to the barrier materials. The filter or filters are preferably flexibly bonded to the barrier material marginally and peripherally of the filter or marginally and peripherally of air or other gas outlet openings in the barrier material, which may be a plastic bag. The filter may be provided with a backing panel of barrier material having an opening or openings for the passage of air or other gas into the filter or filters. Such backing panel is bonded marginally and peripherally thereof to the barrier material or to both it and the filter or filters. A coupling or couplings for deflating and inflating the container may be incorporated. Confining a hazardous waste material in such a container, rapidly deflating the container and disposing of the container, constitutes one aspect of the method of the invention. The chemical bonding procedure for producing the container constitutes another aspect of the method of the invention.

  15. Successful application of Low Voltage Electron Microscopy to practical materials problems

    International Nuclear Information System (INIS)

    Bell, David C.; Mankin, Max; Day, Robert W.; Erdman, Natasha

    2014-01-01

    Low-voltage High-Resolution Electron Microscopy (LVHREM) has several advantages, including increased cross-sections for inelastic and elastic scattering, increased contrast per electron, decreased delocalization effects and reduced knock-on damage. Imaging at differing voltages has shown advantages for imaging materials that are knock-on damage sensitive. We show experimentally that different materials systems benefit from low voltage high-resolution microscopy. There are advantages for imaging single layer materials such as graphene at below the knock-on threshold; we present an example of imaging a graphene sheet at 40 kV. We have also examined mesoporous silica decorated with Pd nanoparticles and carbon black functionalized with Pd/Pt nanoparticles. In these cases we show that the lower voltage imaging maintains the structure of the surrounding matrix during imaging, whereas aberration correction provides the higher resolution for imaging the nanoparticle lattice. Perhaps surprisingly we show that zeolites damage preferentially by ionization effects (radiolysis). The current literature suggests that below incident energies of 40 kV the damage is mainly radiolitic, whereas at incident energies above 200 kV the knock-on damage and material sputtering will be the dominant effect. Our experimental observations support this conclusion and the effects we have observed at 40 kV are not indicative of knock-on damage. Other nanoscale materials such as thin silicon nanowires also benefit from lower voltage imaging. LVHREM imaging provides an excellent option to avoid beam damage to nanowires; our results suggest that LVHREM is suitable for nanowire-biological composites. Our experimental observations serve as a clear demonstration that even at 40 keV accelerating voltage, LVHREM can be used without inducing beam damage to locate dislocations and other crystalline defects, which may have adverse effects on nanowire device performance. Low voltage operation will likely

  16. 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.

  17. e-Biologics: Fabrication of Sustainable Electronics with "Green" Biological Materials.

    Science.gov (United States)

    Lovley, Derek R

    2017-06-27

    The growing ubiquity of electronic devices is increasingly consuming substantial energy and rare resources for materials fabrication, as well as creating expansive volumes of toxic waste. This is not sustainable. Electronic biological materials (e-biologics) that are produced with microbes, or designed with microbial components as the guide for synthesis, are a potential green solution. Some e-biologics can be fabricated from renewable feedstocks with relatively low energy inputs, often while avoiding the harsh chemicals used for synthesizing more traditional electronic materials. Several are completely free of toxic components, can be readily recycled, and offer unique features not found in traditional electronic materials in terms of size, performance, and opportunities for diverse functionalization. An appropriate investment in the concerted multidisciplinary collaborative research required to identify and characterize e-biologics and to engineer materials and devices based on e-biologics could be rewarded with a new "green age" of sustainable electronic materials and devices. Copyright © 2017 Lovley.

  18. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-07-01

    Multi-element analysis of dry biological material by neutron activation analysis has to include radiochemical separation. The evaporation process is described in terms of the half-volume. The pretreatment of the samples and the development of the destruction-evaporation apparatus are described. The successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 are described. Results obtained for standard reference materials are summarized. (G.T.H.)

  19. Nanoscale Structure of Self-Assembling Hybrid Materials of Inorganic and Electronically Active Organic Phases

    Energy Technology Data Exchange (ETDEWEB)

    Sofos, M.; Goswami, D.A. Stone D.K.; Okasinski, J.S.; Jin, H.; Bedzyk, M.J.; Stupp, S.I. (NWU)

    2008-10-06

    Hybrid materials with nanoscale structure that incorporates inorganic and organic phases with electronic properties offer potential in an extensive functional space that includes photovoltaics, light emission, and sensing. This work describes the nanoscale structure of model hybrid materials with phases of silica and electronically active bola-amphiphile assemblies containing either oligo(p-phenylene vinylene) or oligo(thiophene) segments. The hybrid materials studied here were synthesized by evaporation-induced self-assembly and characterized by X-ray scattering techniques. Grazing-incidence X-ray scattering studies of these materials revealed the formation of two-dimensional hexagonally packed cylindrical micelles of the organic molecules with diameters between 3.1 and 3.6 nm and cylindrical axes parallel to the surface. During the self-assembly process at low pH, the cylindrical aggregates of conjugated molecules become surrounded by silica giving rise to a hybrid structure with long-range order. Specular X-ray reflectivity confirmed the long-range periodicity of the hybrid films within a specific range of molar ratios of tetraethyl orthosilicate to cationic amphiphile. We did not observe any long-range ordering in fully organic analogues unless quaternary ammonium groups were replaced by tertiary amines. These observations suggest that charge screening in these biscationic conjugated molecules by the mineral phase is a key factor in the evolution of long range order in the self-assembling hybrids.

  20. Nano-Tomography of Porous Geological Materials Using Focused Ion Beam-Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-10-01

    Full Text Available Tomographic analysis using focused ion beam-scanning electron microscopy (FIB-SEM provides three-dimensional information about solid materials with a resolution of a few nanometres and thus bridges the gap between X-ray and transmission electron microscopic tomography techniques. This contribution serves as an introduction and overview of FIB-SEM tomography applied to porous materials. Using two different porous Earth materials, a diatomite specimen, and an experimentally produced amorphous silica layer on olivine, we discuss the experimental setup of FIB-SEM tomography. We then focus on image processing procedures, including image alignment, correction, and segmentation to finally result in a three-dimensional, quantified pore network representation of the two example materials. To each image processing step we consider potential issues, such as imaging the back of pore walls, and the generation of image artefacts through the application of processing algorithms. We conclude that there is no single image processing recipe; processing steps need to be decided on a case-by-case study.

  1. Writing an Electronic Astronomy Book with Interactive Curricular Material

    Science.gov (United States)

    Thompson, Kristen L.; Belloni, Mario; Christian, Wolfgang

    2015-01-01

    With the rise of tablets, the past few years have seen an increase in the demand for quality electronic textbooks. Unfortunately, most of the current offerings do not exploit the accessibility and interactivity that electronic books can deliver. In this poster, we discuss how we are merging our curriculum development projects (Physlets, Easy Java/JavaScript Simulations, and Open Source Physics) with the EPUB electronic book format to develop an interactive textbook for use in a one-semester introductory astronomy course. The book, Astronomy: An Interactive Introduction, combines the narrative, equations, and images of a traditional astronomy text with new JavaScript simulations.

  2. Electron holography for the study of nanomagnetic materials

    DEFF Research Database (Denmark)

    Thomas, John Meurig; Simpson, Edward T.; Kasama, Takeshi

    2008-01-01

    holography affords deep insight into magnetic phenomena on the nanoscale. Specifically, we describe the unprecedented level of information available regarding the magnetic nature of magnetotactic bacteria, magnetic nanoparticle chains and chiral bracelets, and geochemically relevant phenomena involving......, our Account concludes with examples of some existing enigmas that electron holography, especially when augmented by the related technique of electron tomography, might play an important experimental role in resolving, such as the occurrence of ferromagnetism in nanocrystals of silver within carbon...

  3. Materials Characterization of Electron Beam Melted Ti-6Al-4V

    Science.gov (United States)

    Draper, Susan L.; Lerch, Bradley A.; Telesman, Jack; Martin, Richard E.; Locci, Ivan E.; Garg, Anita; Ring, Andrew J.

    2016-01-01

    An in-depth material characterization of Electron Beam Melted (EBM) Ti-6Al-4V material has been completed on samples fabricated on an ARCAM A2X EBM machine. The specimens were fabricated under eight separate builds with the material divided into two lots for material testing purposes. Hot Isostatic Pressing (HIP) was utilized to close porosity from fabrication and also served as a material heat treatment to obtain the desired microstructure. The changes in the microstructure and chemistry from the powder to pre-HIP and post-HIP material have been analyzed. Several nondestructive evaluation (NDE) techniques were utilized to characterize the samples both before and after HIP. The test matrix included tensile, high cycle fatigue, low cycle fatigue, fracture toughness, and fatigue crack growth at cryogenic, room, and elevated temperatures. The mechanical properties of the EBM Ti-6Al-4V are compared to conventional Ti-6Al-4V in the annealed condition. Fractography was performed to determine failure initiation site. The EBM Ti-6Al-4V had similar or superior mechanical properties compared to conventionally manufactured Ti-6Al-4V.

  4. Shear bond strengths of tooth coating materials including the experimental materials contained various amounts of multi-ion releasing fillers and their effects for preventing dentin demineralization.

    Science.gov (United States)

    Arita, Shoko; Suzuki, Masaya; Kazama-Koide, Miku; Shinkai, Koichi

    2017-10-01

    We examined shear bond strengths (SBSs) of various tooth-coating-materials including the experimental materials to dentin and demineralization resistance of a fractured adhesive surface after the SBS testing. Three resin-type tooth-coating-materials (BC, PRG Barrier Coat; HC, Hybrid Coat II; and SF, Shield force plus) and two glass-ionomer-type tooth-coating-materials (CV, Clinpro XT Varnish; and FJ, Fuji VII) were selected. The experimental PRG Barrier Coat containing 0, 17, and 33 wt% S-PRG filler (BC0, BC17, and BC33, respectively) were developed. Each tooth-coating-material was applied to flattened dentin surfaces of extracted human teeth for SBS testing. After storing in water for 32 days with 4000 thermal cycling, the specimens were subjected to the SBS test. Specimens after SBS testing were subjected to a pH cycling test, and then, demineralization depths were measured using a polarized-light microscope. ANOVA and Tukey's HSD test were used for statistical analysis. The SBS value of FJ and CV was significantly lower than those of other materials except for BC (p coating-materials demonstrated significantly higher SBS for dentin than the glass-ionomer-type tooth-coating-materials; however, they were inferior to the glass ionomer-type tooth-coating-materials in regards to the acid resistance of the fractured adhesion surface.

  5. Secondary Electron Emission Materials for Transmission Dynodes in Novel Photomultipliers: A Review

    Directory of Open Access Journals (Sweden)

    Shu Xia Tao

    2016-12-01

    Full Text Available Secondary electron emission materials are reviewed with the aim of providing guidelines for the future development of novel transmission dynodes. Materials with reflection secondary electron yield higher than three and transmission secondary electron yield higher than one are tabulated for easy reference. Generations of transmission dynodes are listed in the order of the invention time with a special focus on the most recent atomic-layer-deposition synthesized transmission dynodes. Based on the knowledge gained from the survey of secondary election emission materials with high secondary electron yield, an outlook of possible improvements upon the state-of-the-art transmission dynodes is provided.

  6. Mobility and bulk electron-phonon interaction in two-dimensional materials

    DEFF Research Database (Denmark)

    Gunst, Tue; Brandbyge, Mads; Markussen, Troels

    2015-01-01

    -of-plane modes. However, we find that graphene only has a slightly higher mobility compared to silicene. For MoS2 we obtain several orders of magnitude lower mobilities and in agreement with other recent theoretical results. The simulations illustrate the predictive capabilities of the newly implemented......We present calculations of the phonon-limited mobility in intrinsic n-type monolayer graphene, silicene and MoS2. The material properties, including the electron-phonon interaction, are calculated from first principles. Unlike graphene, the carriers in silicene show strong interaction with the out...

  7. "Green" electronics: biodegradable and biocompatible materials and devices for sustainable future.

    Science.gov (United States)

    Irimia-Vladu, Mihai

    2014-01-21

    "Green" electronics represents not only a novel scientific term but also an emerging area of research aimed at identifying compounds of natural origin and establishing economically efficient routes for the production of synthetic materials that have applicability in environmentally safe (biodegradable) and/or biocompatible devices. The ultimate goal of this research is to create paths for the production of human- and environmentally friendly electronics in general and the integration of such electronic circuits with living tissue in particular. Researching into the emerging class of "green" electronics may help fulfill not only the original promise of organic electronics that is to deliver low-cost and energy efficient materials and devices but also achieve unimaginable functionalities for electronics, for example benign integration into life and environment. This Review will highlight recent research advancements in this emerging group of materials and their integration in unconventional organic electronic devices.

  8. Electron-beam-irradiation-induced crystallization of amorphous solid phase change materials

    Science.gov (United States)

    Zhou, Dong; Wu, Liangcai; Wen, Lin; Ma, Liya; Zhang, Xingyao; Li, Yudong; Guo, Qi; Song, Zhitang

    2018-04-01

    The electron-beam-irradiation-induced crystallization of phase change materials in a nano sized area was studied by in situ transmission electron microscopy and selected area electron diffraction. Amorphous phase change materials changed to a polycrystalline state after being irradiated with a 200 kV electron beam for a long time. The results indicate that the crystallization temperature strongly depends on the difference in the heteronuclear bond enthalpy of the phase change materials. The selected area electron diffraction patterns reveal that Ge2Sb2Te5 is a nucleation-dominated material, when Si2Sb2Te3 and Ti0.5Sb2Te3 are growth-dominated materials.

  9. Recent advances in the application of electron tomography to materials chemistry.

    Science.gov (United States)

    Leary, Rowan; Midgley, Paul A; Thomas, John Meurig

    2012-10-16

    Nowadays, tomography plays a central role in pureand applied science, in medicine, and in many branches of engineering and technology. It entails reconstructing the three-dimensional (3D) structure of an object from a tilt series of two-dimensional (2D) images. Its origin goes back to 1917, when Radon showed mathematically how a series of 2D projection images could be converted to the 3D structural one. Tomographic X-ray and positron scanning for 3D medical imaging, with a resolution of ∼1 mm, is now ubiquitous in major hospitals. Electron tomography, a relatively new chemical tool, with a resolution of ∼1 nm, has been recently adopted by materials chemists as an invaluable aid for the 3D study of the morphologies, spatially-discriminating chemical compositions, and defect properties of nanostructured materials. In this Account, we review the advances that have been made in facilitating the recording of the required series of 2D electron microscopic images and the subsequent process of 3D reconstruction of specimens that are vulnerable, to a greater or lesser degree, to electron beam damage. We describe how high-fidelity 3D tomograms may be obtained from relatively few 2D images by incorporating prior structural knowledge into the reconstruction process. In particular, we highlight the vital role of compressed sensing, a recently developed procedure well-known to information theorists that exploits ideas of image compression and "sparsity" (that the important image information can be captured in a reduced data set). We also touch upon another promising approach, "discrete" tomography, which builds into the reconstruction process a prior assumption that the object can be described in discrete terms, such as the number of constituent materials and their expected densities. Other advances made recently that we outline, such as the availability of aberration-corrected electron microscopes, electron wavelength monochromators, and sophisticated specimen goniometers

  10. Complex influence of space environment on materials and electronic devices in the conditions of microgravity

    Science.gov (United States)

    Musabayev, T.; Zhantayev, Zh.; Grichshenko, V.

    2016-09-01

    The paper presents a new physical model describing the processes in materials and electronic devices under the influence of cosmic rays in microgravity. The model identifies specific features of formation of the area of radiation defects (ARD) in the electronic materials in microgravity. The mechanism of interaction between the ARD and memory modules in microgravity causing malfunction and failure of onboard electronics is considered. The results of failure of memory modules under real conditions are presented.

  11. Thermal interface material characterization for cryogenic electronic packaging solutions

    Science.gov (United States)

    Dillon, A.; McCusker, K.; Van Dyke, J.; Isler, B.; Christiansen, M.

    2017-12-01

    As applications of superconducting logic technologies continue to grow, the need for efficient and reliable cryogenic packaging becomes crucial to development and testing. A trade study of materials was done to develop a practical understanding of the properties of interface materials around 4 K. While literature exists for varying interface tests, discrepancies are found in the reported performance of different materials and in the ranges of applied force in which they are optimal. In considering applications extending from top cooling a silicon chip to clamping a heat sink, a range of forces from approximately 44 N to approximately 445 N was chosen for testing different interface materials. For each range of forces a single material was identified to optimize the thermal conductance of the joint. Of the tested interfaces, indium foil clamped at approximately 445 N showed the highest thermal conductance. Results are presented from these characterizations and useful methodologies for efficient testing are defined.

  12. Electron beam accelerator at BARC-BRIT complex - electron beam processing of materials and industrial utilization

    International Nuclear Information System (INIS)

    Khader, S.A.; Patkari, R.K.; Sharma, K.S.S.

    2013-01-01

    During the last decade, the 2MeV/20kW electron beam (EB) accelerator located at BARC-BRIT complex, Vashi has been successfully utilised for non-thermal applications to develop speciality products useful for the industry. Polymer materials are exposed to high energy electrons to induce crosslinking and degradation reactions in a number of industrial products without the use of external chemicals and additives. Various EB crosslinked products viz. PE O-rings, automotive components, automobile tyres, electrical insulations, etc have been found to be much superior in quality compared to those produced conventionally. A process has been developed to enhance colours in the polished diamonds and gem stones using EB irradiation at the facility which has attracted much attention in the Indian diamond industry as a value-addition process. Recycling of polymer waste processed under EB to produce microfine PTFE powder, to reuse in automobile industry etc. has shown good potential for the industrial use. The process feasibility both in terms of economics and technology have been amply demonstrated on a technological scale by installing special conveyors at our facility for irradiating various industrial products. Around 100 km cable insulations, 1.5 million PE O-rings and more than 40000 carats of polished diamonds have been processed in our facility over a period of time on commercial scale. Encouraged with the results, Indian private entrepreneurs have set up dedicated EB machines in some of the most significant industries producing wire and cables, electrical gadgets based on polymer composites, automobile tyres and diamonds. The products are unique in properties and are in some cases, became import substitutes. The industry is now fully geared up to adapt the technology by realising the advantages viz ease in adaptability, convenient, safe and environmental-friendly nature. Encouraged by the process demonstrations, while five EB accelerators were setup and are in operation

  13. Development of High-frequency Soft Magnetic Materials for Power Electronics

    Directory of Open Access Journals (Sweden)

    LIU Jun-chang

    2017-05-01

    Full Text Available The new requirements of high-frequency magnetic properties are put forward for electronic components with the rapid development of power electronics industry and the use of new electromagnetic materials. The properties of magnetic core, which is the key unit of electronic components, determine the performance of electronic components directly. Therefore, it's necessary to study the high-frequency soft magnetic materials. In this paper, the development history of four types of soft magnetic materials was reviewed. The advantages and disadvantages of each kind of soft magnetic materials and future development trends were pointed out. The emphases were placed on the popular soft magnetic composite materials in recent years. The tendency is to develop high-frequency soft magnetic composite materials with the particle size controllable, uniform coating layer on the core and a mass production method from laboratory to industrialization.

  14. Evaluation of Wet Digestion Methods for Quantification of Metal Content in Electronic Scrap Material

    Directory of Open Access Journals (Sweden)

    Subhabrata Das

    2017-11-01

    Full Text Available Recent advances in the electronics sector and the short life-span of electronic products have triggered an exponential increase in the generation of electronic waste (E-waste. Effective recycling of E-waste has thus become a serious solid waste management challenge. E-waste management technologies include pyrometallurgy, hydrometallurgy, and bioleaching. Determining the metal content of an E-waste sample is critical in evaluating the efficiency of a metal recovery method in E-waste recycling. However, E-waste is complex and of diverse origins. The lack of a standard digestion method for E-waste has resulted in difficulty in comparing the efficiencies of different metal recovery processes. In this study, several solid digestion protocols including American Society for Testing and Materials (ASTM-D6357-11, United States Environment Protection Agency Solid Waste (US EPA SW 846 Method 3050b, ultrasound-assisted, and microwave digestion methods were compared to determine the metal content (Ag, Al, Au, Cu, Fe, Ni, Pb, Pd, Sn, and Zn of electronic scrap materials (ESM obtained from two different sources. The highest metal recovery (mg/g of ESM was obtained using ASTM D6357-11 for most of the metals, which remained mainly bound to silicate fractions, while a microwave-assisted digestion protocol (MWD-2 was more effective in solubilizing Al, Pb, and Sn. The study highlights the need for a judicious selection of digestion protocol, and proposes steps for selecting an effective acid digestion method for ESM.

  15. Establishing and Advancing Electronic Nuclear Material Accounting Capabilities: A Canadian Perspective

    International Nuclear Information System (INIS)

    Sample, J.

    2015-01-01

    Under safeguards agreements that the Government of Canada has with the International Atomic Energy Agency (IAEA), and nuclear cooperation agreements with other states, the Canadian Nuclear Safety Commission (CNSC) is required to track the inventory and movement of all safeguarded material. As safeguards programmes evolve, including the implementation of Integrated Safeguards, the scope of the reporting requirements for facilities within Canada has also increased. At the same time, ensuring the secure transmission of the associated data continues to be an overarching factor. The changes that are occurring in the nuclear material accounting (NMA) landscape have necessitated a modernization of Canada's accounting and reporting system, with the objective of creating a more effective and efficient system, while at the same time maintaining the security of prescribed information. After a review of the environment, the CNSC embarked on a project that would encourage facilities to transition away from traditional modes of NMA reporting and adopt an electronic approach. This paper will discuss how the changes to Canada's NMA infrastructure were identified and implemented internally to allow for optimized electronic reporting. Improvements included the development of the regulatory and guidance documents, the overhaul of the reporting forms, the upgrade of the CNSC's NMA database, and the development of an electronic reporting platform that leveraged existing technologies. The paper will also discuss the logistics of engaging stakeholders throughout the process, launching the system and soliciting feedback for future system improvements. Special consideration will be given to the benefits realized by both the CNSC and facilities who have voluntarily embraced electronic reporting. The final objective of this paper will be to identify the challenges that were faced by the CNSC and the nuclear industry as the system changes were implemented and to highlight how

  16. Electron beam disruption simulation of first wall material

    International Nuclear Information System (INIS)

    Quataert, D.; Brossa, F.; Moretto, P.; Rigon, G.

    1984-01-01

    The destructive effect of plasma disruptions on first wall material and limiters has been predicted and models have been made to study their behaviour under intensive pulsed energy deposition. The results presented here give a full description of qualitative and semi-quantitative results obtained for several materials (Mo, stainless steel, Cu, Al, Inconel, etc.) under various experimental conditions. Examples are given of specific defects such as: evaporation, melting, void and crack formation and recrystallization of the underlying material. Methods for the evaluation of deposited energy and beam dimensions are also presented. (author)

  17. Localized Electron Trap Modification as a Result of Space Weather Exposure in Highly Disordered Insulating Materials

    Science.gov (United States)

    2017-03-06

    of Figures and Tables Approved for public release; distribution is unlimited. ii Figure 21 Absorbance spectra of pristine and electron radiation...then the photon may be absorbed . The electron may be an ion-core electron or a free electron in the solid. If the energy of the incoming photon does...color, and, most importantly for these studies, the radiation-induced defects in a material. Fourier transform infrared ( FTIR ) spectroscopy probes

  18. Electron dose distribution due to the material and fabrication of the beam limiting device

    International Nuclear Information System (INIS)

    Chu, S.S.; Choi, K. H.; Lee, D. H.; Choi, B.S.

    1975-01-01

    Electron beams, because of their sharp dose fall off and rapid dose build up, have come to used frequently for radiation therapy, however, have defects that their constriction of isodose curve at depth. These defects of electron beams would be some compensated by electron cones which were made of the most adequate scattering materials according to field sizes and electron energy. We observed the scattering distribution and radiation absorption of various materials; ie.,lead, brass, acyl, steel, aluminium, copper etc, for 8, 10, 12 MeV electron beams. By these data, we designed and made of electron cones which would be delivered the most useful dose distribution in tissue according to electron energy and field sizes. The features of new developmental electron cone would be summarized as follows: 1. Shielding plates,consisted of 1 cm Al, 5 mm Al and 1 cm Acryl, absorbed of 12 MeV electron beam completely and very effective to minimized of bremsstrahlung. 2. Electron cones which their walls were composed of 1 g/cm 2 thickness of transparent materials were convenient to set up and collimate on tumor fields. 3. In small field sizes (10 ∼ 50 cm 2 ),they have favourable dose distribution to use combined wall materials as acryl and Al plates. 4. In medium field sizes (50 ∼ 200 cm 2 ), the dose distributions of electron cones, nothing to do with their composed materials, were relatively satisfactory as 2 ∼ 5% flatness ratio. 5. Designed the cones of 200 cm 2 fields above, it has better dose distribution to make with brass then acryl plates. It was no good to use the lead plate with relatively large bremsstrahlung and materials contained elements to be radioactivated. 7. For increasing of surface dose without energy loss, the 40 ∼ 60 mesh wire netting attached to cone edge are widely used. The materials used in electron cones such as lead, acryl, aluminium, brass etc,. were easy to acquire with reasonable price and tractable.

  19. Hybrid Van Der Waals Materials In Next-Generation Electronics

    Data.gov (United States)

    National Aeronautics and Space Administration — In nature, there exists a class of materials which are inherently two-dimensional (2D). Although they form solid 3D structures, the individual atoms have strong...

  20. Evaluation on electrical resistivity of silicon materials after electron ...

    Indian Academy of Sciences (India)

    Administrator

    3Department of Physics, Balochistan University of Information Technology, Engineering and Management Sciences,. Quetta 87300 ... and the electron beam gun was evacuated to less than. 5.0 × 10–2 and 5.0 × 10–3 ... centre; (c) at the centre; (d) above the centre; (e) at the top and (f) the regions of the cross-section of the.

  1. Exposure of space electronics and materials to ionizing radiation

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C

    1996-01-01

    Describes the methods and sources available for irradiation of space instruments developed at the Department of Automation. Methods for calculations and measurements of fluences and doses are also described. The sources are gamma-rays from iridium-192 and cobalt-60, 30 MeV protons, 10 MeV electrons...

  2. Quantifying the critical thickness of electron hybridization in spintronics materials

    Science.gov (United States)

    Pincelli, T.; Lollobrigida, V.; Borgatti, F.; Regoutz, A.; Gobaut, B.; Schlueter, C.; Lee, T.-L.; Payne, D. J.; Oura, M.; Tamasaku, K.; Petrov, A. Y.; Graziosi, P.; Granozio, F. Miletto; Cavallini, M.; Vinai, G.; Ciprian, R.; Back, C. H.; Rossi, G.; Taguchi, M.; Daimon, H.; van der Laan, G.; Panaccione, G.

    2017-07-01

    In the rapidly growing field of spintronics, simultaneous control of electronic and magnetic properties is essential, and the perspective of building novel phases is directly linked to the control of tuning parameters, for example, thickness and doping. Looking at the relevant effects in interface-driven spintronics, the reduced symmetry at a surface and interface corresponds to a severe modification of the overlap of electron orbitals, that is, to a change of electron hybridization. Here we report a chemically and magnetically sensitive depth-dependent analysis of two paradigmatic systems, namely La1-xSrxMnO3 and (Ga,Mn)As. Supported by cluster calculations, we find a crossover between surface and bulk in the electron hybridization/correlation and we identify a spectroscopic fingerprint of bulk metallic character and ferromagnetism versus depth. The critical thickness and the gradient of hybridization are measured, setting an intrinsic limit of 3 and 10 unit cells from the surface, respectively, for (Ga,Mn)As and La1-xSrxMnO3, for fully restoring bulk properties.

  3. Radiation Effects On Emerging Electronic Materials And Devices

    Science.gov (United States)

    2010-01-17

    Van de Graaff microbeam, the Department of Physics at the University of Jyväskylä (JYFL, in Finland) using a K-130 cyclotron, and the Grand...Conclusion .............................................................................................74 3.26 A Generalized SiGe HBT Single-Event Effects... generated electron-hole pairs as a function of depth (z) and > uniaxial tensile stress

  4. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya

    2016-02-25

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  5. Theoretical Studies on the Electronic Structures and Properties of Complex Ceramic Crystals and Novel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ching, Wai-Yim

    2012-01-14

    This project is a continuation of a long program supported by the Office of Basic Energy Science in the Office of Science of DOE for many years. The final three-year continuation started on November 1, 2005 with additional 1 year extension to October 30, 2009. The project was then granted a two-year No Cost Extension which officially ended on October 30, 2011. This report covers the activities within this six year period with emphasis on the work completed within the last 3 years. A total of 44 papers with acknowledgement to this grant were published or submitted. The overall objectives of this project are as follows. These objectives have been evolved over the six year period: (1) To use the state-of-the-art computational methods to investigate the electronic structures of complex ceramics and other novel crystals. (2) To further investigate the defects, surfaces/interfaces and microstructures in complex materials using large scale modeling. (3) To extend the study on ceramic materials to more complex bioceramic crystals. (4) To initiate the study on soft condensed matters including water and biomolecules. (5) To focus on the spectroscopic studies of different materials especially on the ELNES and XANES spectral calculations and their applications related to experimental techniques. (6) To develop and refine computational methods to be effectively executed on DOE supercomputers. (7) To evaluate mechanical properties of different crystals and those containing defects and relate them to the fundamental electronic structures. (8) To promote and publicize the first-principles OLCAO method developed by the PI (under DOE support for many years) for applications to large complex material systems. (9) To train a new generation of graduate students and postdoctoral fellows in modern computational materials science and condensed matter physics. (10) To establish effective international and domestic collaborations with both experimentalists and theorists in materials

  6. Modeling the interaction of high power ion or electron beams with solid target materials

    International Nuclear Information System (INIS)

    Hassanein, A.M.

    1983-11-01

    Intense energy deposition on first wall materials and other components as a result of plasma disruptions in magnetic fusion devices are expected to cause melting and vaporization of these materials. The exact amount of vaporization losses and melt layer thickness are very important to fusion reactor design and lifetime. Experiments using ion or electron beams to simulate the disruption effects have different environments than the actual disruption conditions in fusion reactors. A model has been developed to accurately simulate the beam-target interactions so that the results from such experiments can be meaningful and useful to reactor design. This model includes a two dimensional solution of the heat conduction equation with moving boundaries. It is found that the vaporization and melting of the sample strongly depends on the characteristics of the beam spatial distribution, beam diameter, and on the power-time variation of the beam

  7. In situ transmission electron microscopy analysis of electron beam induced crystallization of amorphous marks in phase-change materials

    International Nuclear Information System (INIS)

    Kaiser, M.; Pieterson, L. van; Verheijen, M.A.

    2004-01-01

    Crystallization of amorphous data marks in crystalline Ga 15 Sb 85 and Ge,In doped SbTe phase-change material was studied in situ in a Transmission Electron Microscope (TEM). Electron irradiation induced crystallization was obtained at room temperature using a 120 kV beam. In general, electron beam (e - beam) induced crystallization started from the amorphous-crystalline interface and was growth dominated for both materials. A dependence of growth velocity on electron beam intensity and crystal direction was observed. A comparison with laser-crystallized amorphous marks was made. For laser-induced crystallization also crystal growth from the amorphous-crystalline interface was seen. However, differences in morphology between the e - -beam and laser-recrystallized data marks of the GaSb phase-change material were observed. The electron beam erased data marks contained crystals with (extremely) large periodicities found in three dimensions. For the Ge,In doped SbTe phase-change material identical morphologies were observed for the e - -beam and laser-recrystallized data marks. Both methods that induce crystallization displayed a rhombohedral Sb structure, the same structure as the laser-crystallized surroundings

  8. The Structural Characterisation of Risk in the R&D Process of Functional Raw Materials for Electronic Devices

    OpenAIRE

    Chikamori, Yoji; Nasu, Seigo

    2017-01-01

    The electronic materials and electronics device industries remain important to Japan in spite of the general decline of the Japanese electronics industry. There is risk and uncertainty when developing functional materials in the electronics industry. However, studies examining the uncertainty and risk variables in the development of functional materials are scarce. This study examines incremental research and development (R&D) developed for raw functional materials for electronics. Our analys...

  9. Performance and Reliability of Interface Materials for Automotive Power Electronics (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.; DeVoto, D.; Mihalic, M.; Paret, P.

    2013-07-01

    Thermal management and reliability are important because excessive temperature can degrade the performance, life, and reliability of power electronics and electric motors. Advanced thermal management technologies enable keeping temperature within limits; higher power densities; and lower cost materials, configurations and systems. Thermal interface materials, bonded interface materials and the reliability of bonded interfaces are discussed in this presentation.

  10. Strongly correlated electron materials. I. Theory of the quasiparticle structure

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Aguilar, F.; Costa-Quintana, J.; Puig-Puig, L. (Departamento de Fisica, Grupo de Electromagnetismo, Universidad Autonoma de Barcelona, Bellaterra, E-08193 Barcelona (Spain))

    1993-07-01

    In this paper we give a method for analyzing the renormalized electronic structure of the Hubbard systems. The first step is the determination of effective interactions from the random-phase approximation (RPA) and from an extended RPA (ERPA) that introduces vertex effects within the bubble polarization. The second step is the determination of the density of states deduced from the spectral functions. Its analysis leads us to conclude that these systems can exhibit three types of resonances in their electronic structures: the lower-, middle-, and upper-energy resonances. Furthermore, we analyze the conditions for which there is only one type of resonance and the causes that lead to the disappearance of the heavy-fermion state. We finally introduce the RPA and ERPA effective interactions within the strong-coupling theory and we give the conditions for obtaining coupling and superconductivity.

  11. Environmental transmission electron microscopy for catalyst materials using a spherical aberration corrector.

    Science.gov (United States)

    Takeda, Seiji; Kuwauchi, Yasufumi; Yoshida, Hideto

    2015-04-01

    Atomic resolution has been obtained using environmental transmission electron microscopy (ETEM) by installing a spherical aberration corrector (Cs-corrector) on the objective lens. Simultaneously, the technology for controlling the environment around a specimen in ETEM has advanced significantly in the past decade. Quantification methodology has recently been established for deriving relevant experimental data in catalyst materials from substantial and systematic ETEM observation at the atomic scale. With this background, this paper summarizes aspects of the evolutional microscopy technique: necessary conditions for atomic resolution in ETEM; reduction of the scattering of electrons by the medium surrounding a specimen; and an environmental cell for structural imaging of a crystalline specimen. The high spatial resolution of a Cs-corrected ETEM is demonstrated for different observation conditions. After statistical analysis combined with numerical image analysis of ETEM data is briefly described, the recent applications of the Cs-corrected ETEM to catalyst materials are reviewed. For gold nanoparticulate catalysts, the structural information on the reaction sites and adsorption sites are deduced. For Pt nanoparticulate catalysts, ETEM studies elucidate the correlation between the catalytic activity and the morphology of the nanoparticles. These studies also reveal oxidation and reduction on the topmost Pt surface layer at the atomic scale. Finally, current issues and the future perspectives of Cs-corrected ETEM are summarized, including the reproducibility of ETEM observation data, the control of environments, the critical evaluation of electron irradiation effects, the full implementation of transmission electron microscopy technology in ETEM, and the safety issues for an ETEM laboratory. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Evaluation on electrical resistivity of silicon materials after electron ...

    Indian Academy of Sciences (India)

    School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023, PR China; Key Laboratory for Solar Energy Photovoltaic System of Liaoning Province, Dalian 116023, PR China; Department of Physics, Balochistan University of Information Technology, Engineering and Management Sciences ...

  13. Evaluation on electrical resistivity of silicon materials after electron ...

    Indian Academy of Sciences (India)

    It is the result of the evaporation of oxygen during melting process and the segregation of metal impurities during solidification. ... School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023, PR China; Key Laboratory for Solar Energy Photovoltaic System of Liaoning Province, Dalian ...

  14. Combined electronic structure and evolutionary search approach to materials design

    DEFF Research Database (Denmark)

    Johannesson, Gisli Holmar; Bligaard, Thomas; Ruban, Andrei

    2002-01-01

    We show that density functional theory calculations have reached an accuracy and speed making it possible to use them in conjunction with an evolutionary algorithm to search for materials with specific properties. The approach is illustrated by finding the most stable four component alloys out...

  15. X-ray, neutron, and electron scattering. Report of a materials sciences workshop

    International Nuclear Information System (INIS)

    1977-08-01

    The ERDA Workshop on X-ray, Neutron, and Electron Scattering to assess needs and establish priorities for energy-related basic research on materials. The general goals of the Workshop were: (1) to review various energy technologies where x-ray, neutron, and electron scattering techniques might make significant contributions, (2) to identify present and future materials problems in the energy technologies and translate these problems into requirements for basic research by x-ray, neutron, and electron scattering techniques, (3) to recommend research areas utilizing these three scattering techniques that should be supported by the DPR Materials Sciences Program, and (4) to assign priorities to these research areas

  16. Discharge characteristics of dielectric materials examined in mono-, dual-, and spectral energy electron charging environments

    Science.gov (United States)

    Coakley, P.; Treadway, M.; Wild, N.; Kitterer, B.

    1985-01-01

    The effects of midenergy electrons on the charge and discharge characteristics of spacecraft dielectric materials and the data base from which basic discharge models can be formulated is expanded. Thin dielectric materials were exposed to low, mid combined low and mid, and spectral energy electron environments. Three important results are presented: (1) it determined electron environments that lead to dielectric discharges at potentials less negative than -5 kV; (2) two types of discharges were identified that dominate the kinds of discharges seen; and (3) it is shown that, for the thin dielectric materials tested, the worst-case discharges observed in the various environments are similar.

  17. Guide for Operational Configuration Management Program including the adjunct programs of design reconstitution and material condition and aging management

    International Nuclear Information System (INIS)

    1993-11-01

    This standard presents program criteria and implementation guidance for an operational configuration management program for DOE nuclear and non-nuclear facilities in the operational phase. Portions of this standard are also useful for other DOE processes, activities, and programs. This Part 1 contains foreword, glossary, acronyms, bibliography, and Chapter 1 on operational configuration management program principles. Appendices are included on configuration management program interfaces, and background material and concepts for operational configuration management

  18. Electronic structure analyses of BN network materials using high energy-resolution spectroscopy methods based on transmission electron microscopy.

    Science.gov (United States)

    Terauchi, M

    2006-07-01

    Electronic structures of boron-nitride (BN) nanotubes and a BN cone-structure material were studied by using a high energy-resolution electron energy-loss spectroscopy (EELS) microscope. A trial of the whole electronic structure study of hexagonal BN (h-BN), which consists of flat BN honeycomb layers, was conducted by a combination of EELS and X-ray emission spectroscopy (XES) based on transmission electron microscopy (TEM) (TEM-EELS/XES). The pi and pi+sigma plasmon energies of BN nanotubes (BNT) were smaller than those of h-BN. The pi+sigma energy was explained by the surface plasmon excitation. The spectrum of a two-wall BNT of 2.7 nm in diameter showed a new spectral onset at 4 eV. The valence electron excitation spectra obtained from the tip region of the BN cone with an apex angle of 20 degrees showed similar intensity distribution with those of BNTs. The B K-shell electron excitation spectra obtained from the bottom edge region of the BN cone showed additional peak intensity when compared with those of h-BN and BNT. The B K-shell electron excitation spectra and B K-emission spectra of h-BN were compared with a result of a LDA band calculation. It showed that high symmetry points in the band diagram appear as peak and/or shoulder structures in the EELS and XES spectra. Interband transitions appeared in the imaginary part of the dielectric function of h-BN experimentally obtained were assigned in the band diagram. The analysis also presented that the LDA calculation estimated the bandgap energy smaller than the real material by an amount of 2 eV. Those results of TEM-EELS/XES analysis presented that high energy-resolution spectroscopy methods combined with TEM is a promising method to analyze whole electronic structures of nanometer scale materials. Copyright (c) 2006 Wiley-Liss, Inc.

  19. Penetration of an electron beam into material and energy dissipation

    International Nuclear Information System (INIS)

    Kral, V.; Pelzbauer, Z.

    1986-01-01

    The contribution is concerned with penetration of an electron beam having energy between 5 and 25 keV into the polymer and with energy dissipation inside the interaction volume of the polymer. The experimentally observed shape on the interaction volume has been theoretically substantiated, the range has been calculated, and a comparison with Gruen's empirical relation has been carried out. It is shown that with increasing accelerating voltage the centre of the core of the interaction volume is shifted more deeply under the sample surface and the dissipated energy decreases. Extension of the neck of the interaction volume caused by back scattering is discussed. (author)

  20. Electron spectroscopy of carbon materials: experiment and theory

    International Nuclear Information System (INIS)

    El-Barbary, A A; Trasobares, S; Ewels, C P; Stephan, O; Okotrub, A V; Bulusheva, L G; Fall, C J; Heggie, M I

    2006-01-01

    We present a comparative spectroscopic study of carbon as graphite, diamond and C 60 using C1s K-edge electron energy-loss spectroscopy (EELS), X-ray emission spectroscopy, and theoretical modelling. The first principles calculations of these spectra are obtained in the local density approximation using a self-consistent Gaussian basis pseudo-potential method. Calculated spectra show excellent agreement with experiment and are able to discriminate not only between various carbon hybridisations but also local variation in environment. Core-hole effects on the calculated spectra are also investigated. For the first time, the EEL spectrum of carbyne is calculated

  1. Effect of ammonia and electron beam irradiation on lignocelulosic materials

    International Nuclear Information System (INIS)

    Mastro, N.L. del; Gennari, S.M.; Castagnet, A.C.G.

    1986-01-01

    Reports on some of the effects produced on sugarcane bagasse and eucaliptus wood saccharification by combining irradiation and NH 3 treatment. The samples irradiated at 10 5 Gy, 2x10 5 Gy and 5x10 5 Gy with an electron accelerator were treated with anhydrous gaseous ammonia. Cellulase complex from T. reesei was used for hydrolysis assays. Bromatological analysis and 'in vitro' digestibility tests were performed. The combination of EBI and ammonia treatments produced and increase in the saccharification yield, 'in vitro' digestibility and protein content for the two kinds of sample. (Author) [pt

  2. Electron spectroscopy of carbon materials: experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    El-Barbary, A A [University of Sussex, School of Life Sciences, Falmer, Brighton, BN1 9QJ (United Kingdom); University of Ain-Shams, Faculty of Education, Department of Physics, Cairo (Egypt); Trasobares, S [Laboratoire de physique des Solides Batiment 510, Universite Paris Sud 91405, Orsay (France); Departamento de Ciencia de los Materiales Ingenieria Metalurgica Quimica Inorganica, Universidad de Cadiz, Apdo 40 Puerto Real, 11510-Cadiz (Spain); Ewels, C P [University of Sussex, School of Life Sciences, Falmer, Brighton, BN1 9QJ (United Kingdom); Stephan, O [Laboratoire de physique des Solides Batiment 510, Universite Paris Sud 91405, Orsay (France); Okotrub, A V [Nikolaev Institute of Inorganic Chemistry SB RAS, pr. Ak. Lavrentieva 3 (Russian Federation); Bulusheva, L G [Nikolaev Institute of Inorganic Chemistry SB RAS, pr. Ak. Lavrentieva 3 (Russian Federation); Fall, C J [ELCA Informatique SA, Avenue de la Harpe 22-24, CH-1000 Lausanne 13 (Switzerland); Heggie, M I [University of Sussex, School of Life Sciences, Falmer, Brighton, BN1 9QJ (United Kingdom)

    2006-02-22

    We present a comparative spectroscopic study of carbon as graphite, diamond and C{sub 60} using C1s K-edge electron energy-loss spectroscopy (EELS), X-ray emission spectroscopy, and theoretical modelling. The first principles calculations of these spectra are obtained in the local density approximation using a self-consistent Gaussian basis pseudo-potential method. Calculated spectra show excellent agreement with experiment and are able to discriminate not only between various carbon hybridisations but also local variation in environment. Core-hole effects on the calculated spectra are also investigated. For the first time, the EEL spectrum of carbyne is calculated.

  3. Analysis of archaeological materials through Scanning electron microscopy

    International Nuclear Information System (INIS)

    Camacho, A.; Tenorio C, D.; Elizalde, S.; Mandujano, C.; Cassiano, G.

    2005-01-01

    With the purpose to know the uses and the chemical composition of some cultural objects in the pre hispanic epoch this work presents several types of analysis for identifying them by means of the Scanning electron microscopy and its techniques as the Functional analysis of artifacts based on the 'tracks of use' analysis, also the X-ray spectroscopy and the X-ray dispersive energy (EDS) are mentioned, all of them allowing a major approach to the pre hispanic culture in Mexico. (Author)

  4. Dual-mode operation of 2D material-base hot electron transistors

    KAUST Repository

    Lan, Yann-Wen

    2016-09-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  5. PROCESS DEVELOPMENT FOR THE RECOVERY OF CRITICAL MATERIALS FROM ELECTRONIC WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Lister, T. E.; Diaz, L. A.; Clark, G. G.; Keller, P.

    2016-09-01

    As electronic technology continues to evolve there is a growing need to develop processes which recover valuable material from antiquated technology. This need follows from the environmental challenges associated with the availability of raw materials and fast growing generation of electronic waste. Although just present in small quantities in electronic devices, the availability of raw materials, such as rare earths and precious metals, becomes critical for the production of high tech electronic devices and the development of green technologies (i.e. wind turbines, electric motors, and solar panels). Therefore, the proper recycling and processing of increasing volumes of electronic waste present an opportunity to stabilize the market of critical materials, reducing the demand of mined products, and providing a proper disposal and treatment of a hazardous waste stream. This paper will describe development and techno-economic assessment of a comprehensive process for the recovery of value and critical materials from electronic waste. This hydrometallurgical scheme aims to selectively recover different value segments in the materials streams (base metals, precious metals, and rare earths). The economic feasibility for the recovery of rare earths from electronic waste is mostly driven by the efficient recovery of precious metals, such as Au and Pd (ca. 80 % of the total recoverable value). Rare earth elements contained in magnets (speakers, vibrators and hard disk storage) can be recovered as a mixture of rare earths oxides which can later be reduced to the production of new magnets.

  6. Loop-driven graphical unitary group approach to the electron correlation problem, including configuration interaction energy gradients

    International Nuclear Information System (INIS)

    Brooks, B.R.

    1979-09-01

    The Graphical Unitary Group Approach (GUGA) was cast into an extraordinarily powerful form by restructuring the Hamiltonian in terms of loop types. This restructuring allows the adoption of the loop-driven formulation which illuminates vast numbers of previously unappreciated relationships between otherwise distinct Hamiltonian matrix elements. The theoretical/methodological contributions made here include the development of the loop-driven formula generation algorithm, a solution of the upper walk problem used to develop a loop breakdown algorithm, the restriction of configuration space employed to the multireference interacting space, and the restructuring of the Hamiltonian in terms of loop types. Several other developments are presented and discussed. Among these developments are the use of new segment coefficients, improvements in the loop-driven algorithm, implicit generation of loops wholly within the external space adapted within the framework of the loop-driven methodology, and comparisons of the diagonalization tape method to the direct method. It is also shown how it is possible to implement the GUGA method without the time-consuming full (m 5 ) four-index transformation. A particularly promising new direction presented here involves the use of the GUGA methodology to obtain one-electron and two-electron density matrices. Once these are known, analytical gradients (first derivatives) of the CI potential energy are easily obtained. Several test calculations are examined in detail to illustrate the unique features of the method. Also included is a calculation on the asymmetric 2 1 A' state of SO 2 with 23,613 configurations to demonstrate methods for the diagonalization of very large matrices on a minicomputer. 6 figures, 6 tables

  7. High-Purity Semiconducting Single-Walled Carbon Nanotubes: A Key Enabling Material in Emerging Electronics.

    Science.gov (United States)

    Lefebvre, Jacques; Ding, Jianfu; Li, Zhao; Finnie, Paul; Lopinski, Gregory; Malenfant, Patrick R L

    2017-10-17

    Semiconducting single-walled carbon nanotubes (sc-SWCNTs) are emerging as a promising material for high-performance, high-density devices as well as low-cost, large-area macroelectronics produced via additive manufacturing methods such as roll-to-roll printing. Proof-of-concept demonstrations have indicated the potential of sc-SWCNTs for digital electronics, radiofrequency circuits, radiation hard memory, improved sensors, and flexible, stretchable, conformable electronics. Advances toward commercial applications bring numerous opportunities in SWCNT materials development and characterization as well as fabrication processes and printing technologies. Commercialization in electronics will require large quantities of sc-SWCNTs, and the challenge for materials science is the development of scalable synthesis, purification, and enrichment methods. While a few synthesis routes have shown promising results in making near-monochiral SWCNTs, gram quantities are available only for small-diameter sc-SWCNTs, which underperform in transistors. Most synthesis routes yield mixtures of SWCNTs, typically 30% metallic and 70% semiconducting, necessitating the extraction of sc-SWCNTs from their metallic counterparts in high purity using scalable postsynthetic methods. Numerous routes to obtain high-purity sc-SWCNTs from raw soot have been developed, including density-gradient ultracentrifugation, chromatography, aqueous two-phase extraction, and selective DNA or polymer wrapping. By these methods (termed sorting or enrichment), >99% sc-SWCNT content can be achieved. Currently, all of these approaches have drawbacks and limitations with respect to electronics applications, such as excessive dilution, expensive consumables, and high ionic impurity content. Excess amount of dispersant is a common challenge that hinders direct inclusion of sc-SWCNTs into electronic devices. At present, conjugated polymer extraction may represent the most practical route to sc-SWCNTs. By the use of

  8. In Situ Characterization of Nuclear Energy Materials by Synchrotron Radiation and Electron Microscopy

    International Nuclear Information System (INIS)

    Li Meimei

    2015-01-01

    This paper presents the applications of in situ characterization techniques, including transmission electron microscopy (TEM) with in situ ion irradiation and high energy X ray diffraction with simultaneous thermal-mechanical loading, in the study of structural materials in advanced nuclear reactors. A good example cases is given here: a novel experiment of TEM with in situ ion irradiation of Mo thin films by 1 MeV Kr ion irradiation that was designed explicitly to improve and validate a computer model. A rate theory based cluster dynamic model was developed to model the ion irradiation induced damage in the thin film with temporal and spatial dependence of defect distribution. Experimental data were compared in detail with modelling results under exactly matched irradiation conditions. The interplay between experiments and modelling allowed an improved understanding of the physical process during irradiation and the development of an accurate physical model. Another area discussed is that of high energy X ray diffraction measurements of bulk materials under thermal/thermal-mechanical loading. This type of in situ characterization provides information on phase transformation and stability and the effect of microstructural changes on mechanical properties, essential to the development of predictive models of materials’ long term performance in nuclear reactor environments. Currently, an in situ radioactive materials probe is being developed for measuring irradiated materials under temperature and loading conditions. (author)

  9. Noncovalent Intermolecular Interactions in Organic Electronic Materials: Implications for the Molecular Packing vs Electronic Properties of Acenes

    KAUST Repository

    Sutton, Christopher

    2015-10-30

    Noncovalent intermolecular interactions, which can be tuned through the toolbox of synthetic chemistry, determine not only the molecular packing but also the resulting electronic, optical, and mechanical properties of materials derived from π-conjugated molecules, oligomers, and polymers. Here, we provide an overview of the theoretical underpinnings of noncovalent intermolecular interactions and briefly discuss the computational chemistry approaches used to understand the magnitude of these interactions. These methodologies are then exploited to illustrate how noncovalent intermolecular interactions impact important electronic properties-such as the electronic coupling between adjacent molecules, a key parameter for charge-carrier transport-through a comparison between the prototype organic semiconductor pentacene with a series of N-substituted heteropentacenes. Incorporating an understanding of these interactions into the design of organic semiconductors can assist in developing novel materials systems from this fascinating molecular class. © 2015 American Chemical Society.

  10. Basic Mechanisms of Radiation Effects in Electronic Materials and Devices

    Science.gov (United States)

    1987-09-01

    field Is ,𔃽 X 10-4 s. Interface, has been successfully described by a continuous-time-random-walk ( CTRW ) formalism The specific Interslte hopping...curve In figure 16 Is lowing pulsed LINAC electron-beam exposure for 96.5.nm the calculated response based on the CTRW model oxide MOS capacitor at 80... CTRW MODEL Q 194 K(a-=0.25) 181 K 0.75 - 160 K 0 141K 0 124 K Io . 10-8 i0-1 10i- 10.8 10-4 10-3 10-2 10-1 100 101 102 101 10 4 101 10a SCALED TME (Vt

  11. Electron transport system activity of microfouling material: Relationships with biomass parameters

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Tulaskar, A.; Wagh, A.B.

    Microfouling material developed on aluminium panels immersed in surface waters of the Dona Paula Bay, Goa India was analysed for biomass (measured as dry weight, organic crabon, protein and chlorophyll @ia@@) and electron transport system actitity...

  12. Electronic properties of crystalline materials observed in X-ray diffraction

    Science.gov (United States)

    Lovesey, S. W.; Balcar, E.; Knight, K. S.; Fernández Rodríguez, J.

    2005-05-01

    The few electrons in valence states of a material participate in many of its physical properties, including both structural and transport properties. In the diffraction of X-rays, or neutrons, valence electrons can lead to weak Bragg reflections that are extremely sensitive signatures of their charge and magnetic degrees of freedom. In this regard, diffraction instruments supplied with X-rays from a synchrotron source are particularly useful because the brightness, tuneability and polarization of the X-rays are all helpful in making valuable observations. The data obtained from Bragg diffraction can be analyzed on the basis of an atomic model, which has the virtue that it can be used as a common platform for the analysis of X-ray and neutron diffraction and, in addition, the analysis of observations made with X-ray absorption, NMR, EPR, muon and Mössbauer spectroscopies. We present the salient features for the calculation of structure factors based on an atomic model and applied to the analysis of Bragg diffraction by non-magnetic and magnetic materials, with an emphasis on resonant X-ray Bragg diffraction. The presentation contains a new treatment of parity-odd events found in the mixed electric dipole-electric quadrupole channel of scattering. In addition we discuss the complementary observation of dichroic signals, including natural circular and magnetochiral dichroism. The survey of available analytical tools is complemented by a series of worked examples demonstrating the application of the formalism to different materials with different crystal structures and resonant ions: dysprosium borocarbide ( DyB2C2), vanadium sesquioxide (V2O3), gadolinium tetraboride ( GdB4), chromium sesquioxide ( Cr2O3), haematite and perovskite-type manganites.

  13. Electronic properties of crystalline materials observed in X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Lovesey, S.W. [Diamond Light Source Ltd., ISIS Facility, RAL, Oxfordshire OX11 0QX (United Kingdom) and RIKEN Harima Institute, SPring-8, Hyogo 679-5148 (Japan)]. E-mail: s.w.lovesey@rl.ac.uk; Balcar, E. [Vienna University of Technology, Atominstitut, Stadionallee 2, A1020, Vienna (Austria); Knight, K.S. [Diamond Light Source Ltd., ISIS Facility, RAL, Oxfordshire OX11 0QX (United Kingdom); Department of Mineralogy, Natural History Museum, London SW7 5BD (United Kingdom); Fernandez Rodriguez, J. [Departamento de Fisica, Universidad de Oviedo, E-33007 Oviedo (Spain)

    2005-05-01

    The few electrons in valence states of a material participate in many of its physical properties, including both structural and transport properties. In the diffraction of X-rays, or neutrons, valence electrons can lead to weak Bragg reflections that are extremely sensitive signatures of their charge and magnetic degrees of freedom. In this regard, diffraction instruments supplied with X-rays from a synchrotron source are particularly useful because the brightness, tuneability and polarization of the X-rays are all helpful in making valuable observations. The data obtained from Bragg diffraction can be analyzed on the basis of an atomic model, which has the virtue that it can be used as a common platform for the analysis of X-ray and neutron diffraction and, in addition, the analysis of observations made with X-ray absorption, NMR, EPR, muon and Mossbauer spectroscopies. We present the salient features for the calculation of structure factors based on an atomic model and applied to the analysis of Bragg diffraction by non-magnetic and magnetic materials, with an emphasis on resonant X-ray Bragg diffraction. The presentation contains a new treatment of parity-odd events found in the mixed electric dipole-electric quadrupole channel of scattering. In addition we discuss the complementary observation of dichroic signals, including natural circular and magnetochiral dichroism. The survey of available analytical tools is complemented by a series of worked examples demonstrating the application of the formalism to different materials with different crystal structures and resonant ions: dysprosium borocarbide (DyB{sub 2}C{sub 2}), vanadium sesquioxide (V{sub 2}O{sub 3}), gadolinium tetraboride (GdB{sub 4}), chromium sesquioxide (Cr{sub 2}O{sub 3}), haematite and perovskite-type manganites.

  14. [Realistic theories of heavy electron and other strongly correlated materials

    International Nuclear Information System (INIS)

    1993-01-01

    Research on the following topics is summarized: non-perturbative treatments of multi-channel Kondo models, non-perturbative treatments of multi-band models for the quadrupolar fluctuation model of the cuprates, extension of the two-channel Kondo model to other materials and treatment of the infinite-dimensional Hubbard model within the Non-crossing approximation. Data on the specific heat of Y 0.8 U 0.2 Pd 3 and the c-axis susceptibility and specific heat of U in ThRu 2 Si are shown. 5 figs., 84 refs

  15. [Realistic theories of heavy electron and other strongly correlated materials

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    Research on the following topics is summarized: non-perturbative treatments of multi-channel Kondo models, non-perturbative treatments of multi-band models for the quadrupolar fluctuation model of the cuprates, extension of the two-channel Kondo model to other materials and treatment of the infinite-dimensional Hubbard model within the Non-crossing approximation. Data on the specific heat of Y{sub 0.8}U{sub 0.2}Pd{sub 3} and the c-axis susceptibility and specific heat of U in ThRu{sub 2}Si are shown. 5 figs., 84 refs.

  16. Magnetic field effects on runaway electron energy deposition in plasma facing materials and components

    International Nuclear Information System (INIS)

    Niemer, K.A.; Gilligan, J.G.

    1992-01-01

    This paper reports magnetic field effects on runaway electron energy deposition in plasma facing materials and components is investigated using the Integrated TIGER Series. The Integrated TIGER Series is a set of time-independent coupled electron/photon Monte Carlo transport codes which perform photon and electron transport, with or without macroscopic electric and magnetic fields. A three-dimensional computational model of 100 MeV electrons incident on a graphite block was used to simulate runawayelectrons striking a plasma facing component at the edge of a tokamak. Results show that more energy from runaway electrons will be deposited in a material that is in the presence of a magnetic field than in a material that is in the presence of no field. For low angle incident runaway electrons in a strong magnetic field, the majority of the increased energy deposition is near the material surface with a higher energy density. Electrons which would have been reflected with no field, orbit the magnetic field lines and are redeposited in the material surface, resulting in a substantial increase in surface energy deposition. Based on previous studies, the higher energy deposition and energy density will result in higher temperatures which are expected to cause more damage to a plasma facing component

  17. A Theoretical Study of a Novel Single-Electron Refrigerator Fabricated from Semiconductor Materials

    OpenAIRE

    Ikeda, Hiroya; Salleh, Faiz

    2011-01-01

    We propose a novel single-electron refrigerator (SER) that can be fabricated from semiconductor materials such as a silicon-on-insulator wafer. The SER consists of a single-electron box and a single-electron pump (SEP). An equivalent circuit of the SEP refrigerator was derived. Its stability diagram (Coulomb diamond) was theoretically calculated and found to have a distorted honeycomb structure. In addition, a Monte Carlo simulation based on the orthodox theory for the Coulomb blockade phenom...

  18. Applications of Real Space Crystallography in Characterization of Dislocations in Geological Materials in a Scanning Electron Microscope (SEM)

    Science.gov (United States)

    Kaboli, S.; Burnley, P. C.

    2017-12-01

    Imaging and characterization of defects in crystalline materials is of significant importance in various disciplines including geoscience, materials science, and applied physics. Linear defects such as dislocations and planar defects such as twins and stacking faults, strongly influence many of the properties of crystalline materials and also reflect the conditions and degree of deformation. Dislocations have been conventionally imaged in thin foils in a transmission electron microscope (TEM). Since the development of field emission scanning electron microscopes (FE-SEM) with high gun brightness and small spot size, extensive efforts have been dedicated to the imaging and characterization of dislocations in semi-conductors using electron channeling contrast imaging (ECCI) in the SEM. The obvious advantages of using SEM over TEM include easier and non-destructive sample preparation and a large field of view enabling statistical examination of the density and distribution of dislocations and other defects. In this contribution, we extend this technique to geological materials and introduce the Real Space Crystallography methodology for imaging and complete characterization of dislocations based on bend contour contrast obtained by ECCI in FE-SEM. Bend contours map out the distortion in the crystal lattice across a deformed grain. The contrast of dislocations is maximum in the vicinity of bend contours where crystal planes diffract at small and positive deviations from the Bragg positions (as defined by Bragg's law of electron diffraction). Imaging is performed in a commercial FE-SEM equipped with a standard silicon photodiode backscattered (BSE) detector and an electron backscatter diffraction (EBSD) system for crystal orientation measurements. We demonstrate the practice of this technique in characterization of a number of geological materials in particular quartz, forsterite olivine and corundum, experimentally deformed at high pressure-temperature conditions. This

  19. Analysis of quantum ballistic electron transport in ultrasmall silicon devices including space-charge and geometric effects

    Science.gov (United States)

    Laux, S. E.; Kumar, A.; Fischetti, M. V.

    2004-05-01

    A two-dimensional device simulation program which self consistently solves the Schrödinger and Poisson equations with current flow is described in detail. Significant approximations adopted in this work are the absence of scattering and a simple six-valley, parabolic band structure for silicon. A modified version of the quantum transmitting boundary method is used to describe open boundary conditions permitting current flow in device solutions far from equilibrium. The continuous energy spectrum of the system is discretized by temporarily imposing two different forms of closed boundary conditions, resulting in energies which sample the density-of-states and establish the wave function normalization conditions. These standing wave solutions ("normal modes") are decomposed into their traveling wave constituents, each of which represents injection from only one of the open boundary contacts ("traveling eigencomponents"). These current-carrying states are occupied by a drifted Fermi distribution associated with their injecting contact and summed to form the electron density in the device. Holes are neglected in this calculation. The Poisson equation is solved on the same finite element computational mesh as the Schrödinger equation; devices of arbitrary geometry can be modeled. Computational performance of the program including characterization of a "Broyden+Newton" algorithm employed in the iteration for self consistency is described. Device results are presented for a narrow silicon resonant tunneling diode (RTD) and many variants of idealized silicon double-gate field effect transistors (DGFETs). The RTD results show two resonant conduction peaks, each of which demonstrates hysteresis. Three 7.5 nm channel length DGFET structures with identical intrinsic device configurations but differing access geometries (straight, taper and "dog bone") are studied and found to have differing current flows owing to quantum-mechanical reflection in their access regions

  20. Real time monitoring of electronic materials and devices using microbeams

    International Nuclear Information System (INIS)

    Manfredotti, C.

    2002-01-01

    IBIC and IBIL techniques with proton microbeams of diameter of the order of 1 μm and of energy in the interval 2 MeV-6 MeV have been used in different configurations and geometries in order to characterize frontier semiconducting or insulating materials like GaAs and CVD diamond, or more traditional materials like Si, by looking at space distribution of important transport parameters like drift and diffusion lengths. By applying lateral IBIC in GaAs Schottky diodes it had been possible to follow directly the widening of depletion region as a function of bias voltage, while for Si drift/diffusion structures a particular code has been developed in order to measure directly the diffusion length and lifetime of minority carriers. In CVD diamond both IBIC and IBIL measurements have been performed in frontal and lateral geometries. The main results are represented by the correlation between IBIC maps and morphology of the grains, with the conclusion that collection length is limited by the grain dimensions, by the proof of the validity of the linear model, by the clarification of the spatial behaviour of the 'primed' or irradiated state in terms of homogenization and improvement of charge collection length and, finally, by the observation of a quasi-complementarity in space between IBIC and IBIL maps, with the conclusion that in CVD diamond the recombination is mainly radiative. Moreover, concerning nitrogen content, a method has been proposed in order to forecast the detector quality of CVD diamond from IBIL spectra. (author)

  1. Advanced electron microscopy of wide band-gap semiconductor materials

    International Nuclear Information System (INIS)

    Fay, M.W.

    2000-10-01

    The microstructure of GaN layers grown by metal organic vapour phase epitaxy on (0001) sapphire substrates using a novel precursor for deposition of AlN buffer layers has been investigated and compared to layers grown using low temperature GaN buffer layers and state-of-the-art material. It has been shown that the quality of layers grown using the novel precursor is comparable to the state-of-the-art material. TEM analysis has been performed of multiple quantum wells of InGaN grown within GaN epitaxial layers by metal organic vapour phase epitaxy. Elementally sensitive TEM techniques have been used to determine the spatial distribution of In and Ga within these structures. Fluctuations in In sensitive images are observed on the nm-scale. Clear evidence of segregation of In during layer growth has been seen. Models of the In segregation are in good agreement with experimental results. Elementally sensitive techniques have been used to investigate the elemental distributions in TiAl and NiAu contacts to GaN. Annealing of TiAl contacts has been seen to result in the formation of a thin interfacial Ti rich phase, and of N depletion at the surface of the GaN layer to the depth of tens of nm. Annealing NiAu contacts at 700 deg. C was seen to result in the formation of Ga-rich interfacial phases, of both crystalline and amorphous structure. ZnS and ZnCdS layers grown on (001) GaP supplied by the University of Hull have been investigated. ZnS layers were found to contain a high density of inclined stacking faults throughout the layer, originating from the interface with the substrate. Energy sensitive techniques have been used to investigate ZnCdS quantum well structures. The use of a ZnCdS superlattice structure around a ZnCdS quantum well to approximate a reduced barrier was seen to result in less thickness variations than when no barrier was used. (author)

  2. Electroactive materials for organic electronics: preparation strategies, structural aspects and characterization techniques.

    Science.gov (United States)

    Pron, Adam; Gawrys, Pawel; Zagorska, Malgorzata; Djurado, David; Demadrille, Renaud

    2010-07-01

    This critical review discusses specific chemical and physicochemical requirements which must be met for organic compounds to be considered as promising materials for applications in organic electronics. Although emphasis is put on molecules and macromolecules suitable for fabrication of field effect transistors (FETs), a large fraction of the discussed compounds can also be applied in other organic or hybrid (organic-inorganic) electronic devices such as photodiodes, light emitting diodes, photovoltaic cells, etc. It should be of interest to chemists, physicists, material scientists and electrical engineers working in the domain of organic electronics (423 references).

  3. Radiation Damage Studies of Materials and Electronic Devices Using Hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Pellett, David; Baldwin, Andrew; Gallagher, Garratt; Olson, David; Styczinski, Marshall

    2014-05-14

    We have irradiated NdFeB permanent magnet samples from different manufacturers and with differing values of coercivity and remanence using stepped doses of 1 MeV equivalent neutrons up to a fluence of 0:64 1015n=cm2 to evaluate effects on magnetization and B field distributions. The samples with high coercivity, irradiated in open circuit configurations, showed no or minimal effects when compared with unirradiated samples, whereas the lower coercivity magnets suffered significant losses of magnetization and changes in the shapes of their field patterns. One such magnet underwent a fractional magnetization loss of 13.1% after a fluence of 0:59 1015 n=cm2. This demagnetization was not uniform. With increasing fluence, B field scans along the centerlines of the pole faces revealed that the normal component of B decreased more near the midpoint of the scan than near the ends. In addition, a fit to the curve of overall magnetization loss with fluence showed a significant deviation from linearity. The results are discussed in light of other measurements and theory. The high coercivity materials appear suitable for use in accelerator applications subject to irradiation by fast neutrons such as dipoles where the internal demagnetizing field is comparable to or less than that of the open circuit samples tested in this study.

  4. Proceedings, strongly correlated electronic materials: The Los Alamos symposium 1993

    International Nuclear Information System (INIS)

    Bedell, K.S.

    1994-01-01

    The subject included such topics as high temperature superconductors, heavy-fermion insulators and superconductors, the metal-insulator transition, the superconductor-insulator transition and unusual (non-Fermi liquid) normal metallic states. The symposium was structured around 13 invited review talks; with each talk, there were several (about 30) related short presentations and discussion sections (90 pages). The review talks and short papers were processed separately for the data base

  5. Development of new materials from waste electrical and electronic equipment: Characterization and catalytic application.

    Science.gov (United States)

    Souza, J P; Freitas, P E; Almeida, L D; Rosmaninho, M G

    2017-07-01

    Wastes of electrical and electronic equipment (WEEE) represent an important environmental problem, since its composition includes heavy metals and organic compounds used as flame-retardants. Thermal treatments have been considered efficient processes on removal of these compounds, producing carbonaceous structures, which, together with the ceramic components of the WEEE (i.e. silica and alumina), works as support material for the metals. This mixture, associated with the metals present in WEEE, represents promising systems with potential for catalytic application. In this work, WEEE was thermally modified to generate materials that were extensively characterized. Raman spectrum for WEEE after thermal treatment showed two carbon associated bands. SEM images showed a metal nanoparticles distribution over a polymeric and ceramic support. After characterization, WEEE materials were applied in ethanol steam reforming reaction. The system obtained at higher temperature (800°C) exhibited the best activity, since it leads to high conversions (85%), hydrogen yield (30%) and H 2 /CO ratio (3,6) at 750°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Highly Conductive Transparent and Flexible Electrodes Including Double-Stacked Thin Metal Films for Transparent Flexible Electronics.

    Science.gov (United States)

    Han, Jun Hee; Kim, Do-Hong; Jeong, Eun Gyo; Lee, Tae-Woo; Lee, Myung Keun; Park, Jeong Woo; Lee, Hoseung; Choi, Kyung Cheol

    2017-05-17

    To keep pace with the era of transparent and deformable electronics, electrode functions should be improved. In this paper, an innovative structure is suggested to overcome the trade-off between optical and electrical properties that commonly arises with transparent electrodes. The structure of double-stacked metal films showed high conductivity (electronics are expected.

  7. Halide-Dependent Electronic Structure of Organolead Perovskite Materials

    KAUST Repository

    Buin, Andrei

    2015-06-23

    © 2015 American Chemical Society. Organometal halide perovskites have recently attracted tremendous attention both at the experimental and theoretical levels. These materials, in particular methylammonium triiodide, are still limited by poor chemical and structural stability under ambient conditions. Today this represents one of the major challenges for polycrystalline perovskite-based photovoltaic technology. In addition to this, the performance of perovskite-based devices is degraded by deep localized states, or traps. To achieve better-performing devices, it is necessary to understand the nature of these states and the mechanisms that lead to their formation. Here we show that the major sources of deep traps in the different halide systems have different origin and character. Halide vacancies are shallow donors in I-based perovskites, whereas they evolve into a major source of traps in Cl-based perovskites. Lead interstitials, which can form lead dimers, are the dominant source of defects in Br-based perovskites, in line with recent experimental data. As a result, the optimal growth conditions are also different for the distinct halide perovskites: growth should be halide-rich for Br and Cl, and halide-poor for I-based perovskites. We discuss stability in relation to the reaction enthalpies of mixtures of bulk precursors with respect to final perovskite product. Methylammonium lead triiodide is characterized by the lowest reaction enthalpy, explaining its low stability. At the opposite end, the highest stability was found for the methylammonium lead trichloride, also consistent with our experimental findings which show no observable structural variations over an extended period of time.

  8. Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

    Directory of Open Access Journals (Sweden)

    Jacob Maxa

    2017-12-01

    Full Text Available Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

  9. Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

    Science.gov (United States)

    Maxa, Jacob; Novikov, Andrej; Nowottnick, Mathias

    2017-01-01

    Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

  10. Lanthanum Gadolinium Oxide: A New Electronic Device Material for CMOS Logic and Memory Devices

    Directory of Open Access Journals (Sweden)

    Shojan P. Pavunny

    2014-03-01

    Full Text Available A comprehensive study on the ternary dielectric, LaGdO3, synthesized and qualified in our laboratory as a novel high-k dielectric material for logic and memory device applications in terms of its excellent features that include a high linear dielectric constant (k of ~22 and a large energy bandgap of ~5.6 eV, resulting in sufficient electron and hole band offsets of ~2.57 eV and ~1.91 eV, respectively, on silicon, good thermal stability with Si and lower gate leakage current densities within the International Technology Roadmap for Semiconductors (ITRS specified limits at the sub-nanometer electrical functional thickness level, which are desirable for advanced complementary metal-oxide-semiconductor (CMOS, bipolar (Bi and BiCMOS chips applications, is presented in this review article.

  11. Investigation of Electron Transfer-Based Photonic and Electro-Optic Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Bromenshenk, Jerry J; Abbott, Edwin H; Dickensheets, David; Donovan, Richard P; Hobbs, J D; Spangler, Lee; McGuirl, Michele A; Spangler, Charles; Rebane, Aleksander; Rosenburg, Edward; Schmidt, V H; Singel, David J

    2008-03-28

    Montana's state program began its sixth year in 2006. The project's research cluster focused on physical, chemical, and biological materials that exhibit unique electron-transfer properties. Our investigators have filed several patents and have also have established five spin-off businesses (3 MSU, 2 UM) and a research center (MT Tech). In addition, this project involved faculty and students at three campuses (MSU, UM, MT Tech) and has a number of under-represented students, including 10 women and 5 Native Americans. In 2006, there was an added emphasis on exporting seminars and speakers via the Internet from UM to Chief Dull Knife Community College, as well as work with the MT Department of Commerce to better educate our faculty regarding establishing small businesses, licensing and patent issues, and SBIR program opportunities.

  12. A Theoretical Study of a Novel Single-Electron Refrigerator Fabricated from Semiconductor Materials

    Science.gov (United States)

    Ikeda, Hiroya; Salleh, Faiz

    2011-06-01

    We propose a novel single-electron refrigerator (SER) that can be fabricated from semiconductor materials such as a silicon-on-insulator wafer. The SER consists of a single-electron box and a single-electron pump (SEP). An equivalent circuit of the SEP refrigerator was derived. Its stability diagram (Coulomb diamond) was theoretically calculated and found to have a distorted honeycomb structure. In addition, a Monte Carlo simulation based on the orthodox theory for the Coulomb blockade phenomenon predicts successful single-electron extraction and injection.

  13. Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

    Science.gov (United States)

    Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

    2015-09-28

    The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

  14. First-Principles Calculations of Electronic, Optical, and Transport Properties of Materials for Energy Applications

    Science.gov (United States)

    Shi, Guangsha

    Solar electricity is a reliable and environmentally friendly method of sustainable energy production and a realistic alternative to conventional fossil fuels. Moreover, thermoelectric energy conversion is a promising technology for solid-state refrigeration and efficient waste-heat recovery. Predicting and optimizing new photovoltaic and thermoelectric materials composed of Earth-abundant elements that exceed the current state of the art, and understanding how nanoscale structuring and ordering improves their energy conversion efficiency pose a challenge for materials scientists. I approach this challenge by developing and applying predictive high-performance computing methods to guide research and development of new materials for energy-conversion applications. Advances in computer-simulation algorithms and high-performance computing resources promise to speed up the development of new compounds with desirable properties and significantly shorten the time delay between the discovery of new materials and their commercial deployment. I present my calculated results on the extraordinary properties of nanostructured semiconductor materials, including strong visible-light absorbance in nanoporous silicon and few-layer SnSe and GeSe. These findings highlight the capability of nanoscale structuring and ordering to improve the performance of Earth-abundant materials compared to their bulk counterparts for solar-cell applications. I also successfully identified the dominant mechanisms contributing to free-carrier absorption in n-type silicon. My findings help evaluate the impact of the energy loss from this absorption mechanism in doped silicon and are thus important for the design of silicon solar cells. In addition, I calculated the thermoelectric transport properties of p-type SnSe, a bulk material with a record thermoelectric figure of merit. I predicted the optimal temperatures and free-carrier concentrations for thermoelectric energy conversion, as well the

  15. Characterizing deformed ultrafine-grained and nanocrystalline materials using transmission Kikuchi diffraction in a scanning electron microscope

    International Nuclear Information System (INIS)

    Trimby, Patrick W.; Cao, Yang; Chen, Zibin; Han, Shuang; Hemker, Kevin J.; Lian, Jianshe; Liao, Xiaozhou; Rottmann, Paul; Samudrala, Saritha; Sun, Jingli; Wang, Jing Tao; Wheeler, John; Cairney, Julie M.

    2014-01-01

    Graphical abstract: -- Abstract: The recent development of transmission Kikuchi diffraction (TKD) in a scanning electron microscope enables fast, automated orientation mapping of electron transparent samples using standard electron backscatter diffraction (EBSD) hardware. TKD in a scanning electron microscope has significantly better spatial resolution than conventional EBSD, enabling routine characterization of nanocrystalline materials and allowing effective measurement of samples that have undergone severe plastic deformation. Combining TKD with energy dispersive X-ray spectroscopy (EDS) provides complementary chemical information, while a standard forescatter detector system below the EBSD detector can be used to generate dark field and oriented dark field images. Here we illustrate the application of this exciting new approach to a range of deformed, ultrafine grained and nanocrystalline samples, including duplex stainless steel, nanocrystalline copper and highly deformed titanium and nickel–cobalt. The results show that TKD combined with EDS is a highly effective and widely accessible tool for measuring key microstructural parameters at resolutions that are inaccessible using conventional EBSD

  16. X-ray photoemission electron microscopy for the study of semiconductor materials

    International Nuclear Information System (INIS)

    Anders, Simone; Stammler, Thomas; Padmore, Howard A.; Terminello, Louis J.; Jankowski, Alan F.; Stoehr, Joachim; Diaz, Javier; Cossy-Favre, Aline; Singh, Sangeet

    1998-01-01

    Photoemission Electron Microscopy using X-rays (X-PEEM) is a novel combination of two established materials analysis techniques--PEEM using UV light, and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. This combination allows the study of elemental composition and bonding structure of the sample by NEXAFS spectroscopy with a high spatial resolution given by the microscope. A simple, two lens, 10 kV operation voltage PEEM has been used at the Stanford Synchrotron Radiation Laboratory and at the Advanced Light Source (ALS) in Berkeley to study various problems including materials of interest for the semiconductor industry. In the present paper we give a short overview over the method and the instrument which was used, and describe in detail a number of applications. These applications include the study of the different phases of titanium disilicide, various phases of boron nitride, and the analysis of small particles. A brief outlook is given on possible new fields of application of the PEEM technique, and the development of new PEEM instruments

  17. X-ray photoemission electron microscopy for the study of semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S.; Stammler, T.; Padmore, H. [Lawrence Berkeley National Lab., CA (United States). Advanced Light Source Div.; Terminello, L.J.; Jankowski, A.F. [Lawrence Livermore National Lab., CA (United States); Stohr, J. [IBM Almaden Research Center, San Jose, CA (United States); Diaz, J. [Univ. de Oviedo (Spain). Dept. de Fisica; Cossy-Gantner, A. [EMPA, Duebendorf (Germany)

    1998-03-01

    Photoemission Electron Microscopy (PEEM) using X-rays is a novel combination of two established materials analysis techniques--PEEM using UV light, and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. This combination allows the study of elemental composition and bonding structure of the sample by NEXAFS spectroscopy with a high spatial resolution given by the microscope. A simple, two lens, 10 kV operation voltage PEEM has been used at the Stanford Synchrotron Radiation Laboratory and at the Advanced Light Source (ALS) in Berkeley to study various problems including materials of interest for the semiconductor industry. In the present paper the authors give a short overview over the method and the instrument which was used, and describe in detail a number of applications. These applications include the study of the different phases of titanium disilicide, various phases of boron nitride, and the analysis of small particles. A brief outlook is given on possible new fields of application of the PEEM technique, and the development of new PEEM instruments.

  18. X-ray photoemission electron microscopy for the study of semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S.; Stammler, T.; Padmore, H.A. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Terminello, L.J.; Jankowski, A.F. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States); Stoehr, J. [IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Diaz, J. [Departamento de Fisic, Facultad de Ciencias, Universidad de Oviedo, Avda. Calvo Sotelo s/n, Oviedo, 33007 (Spain); Cossy-Favre, A. [EMPA, Duebendorf, Ueberlandstrasse 129, 8600 Duebendorf (Switzerland); Singh, S. [Center for X-ray Lithography, University of Wisconsin-Madison, Stoughton, Wisconsin 53589 (United States)

    1998-11-01

    Photoemission Electron Microscopy using X-rays (X-PEEM) is a novel combination of two established materials analysis techniques{emdash}PEEM using UV light, and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. This combination allows the study of elemental composition and bonding structure of the sample by NEXAFS spectroscopy with a high spatial resolution given by the microscope. A simple, two lens, 10 kV operation voltage PEEM has been used at the Stanford Synchrotron Radiation Laboratory and at the Advanced Light Source (ALS) in Berkeley to study various problems including materials of interest for the semiconductor industry. In the present paper we give a short overview over the method and the instrument which was used, and describe in detail a number of applications. These applications include the study of the different phases of titanium disilicide, various phases of boron nitride, and the analysis of small particles. A brief outlook is given on possible new fields of application of the PEEM technique, and the development of new PEEM instruments. {copyright} {ital 1998 American Institute of Physics.}

  19. Pulsed laser processing of electronic materials in micro/nanoscale

    Science.gov (United States)

    Hwang, David Jen

    2005-08-01

    Time-resolved pump-and-probe side-view imaging has been performed to investigate the energy coupling to the target specimen over a wide range of fluences. Plasmas generated during the laser ablation process are visualized and the decrease of the ablation efficiency in the high fluence regime (>10 J/cm2) is attributed to the strong interaction of the laser pulse with the laser-induced plasmas. The high intensity ultra-short laser pulses also trigger volumetric multi-photon absorption (MPA) processes that can be beneficial in applications such as three-dimensional bulk modification of transparent materials. Femtosecond laser pulses were used to fabricate straight and bent through-channels in the optical glass. Drilling was initiated from the rear surface to preserve consistent absorbing conditions of the laser pulse. Machining in the presence of a liquid solution assisted the debris ejection. Drilling process was further enhanced by introducing ultrasonic waves, thereby increasing the aspect ratio of drilled holes and improving the quality of the holes. In conventional lens focusing schemes, the minimum feature size is determined by the diffraction limit. Finer resolution is accomplished by combining pulsed laser radiation with Near-field Scanning Optical Microscopy (NSOM) probes. Short laser pulses are coupled to a fiber-based NSOM probes in order to ablate thin metal films. A detailed parametric study on the effects of probe aperture size, laser pulse energy, temporal width and environment gas is performed. The significance of lateral thermal diffusion is highlighted and the dependence of the ablation process on the imparted near-field distribution is revealed. As a promising application of laser ablation in nanoscale, laser induced breakdown spectroscopy (LIBS) system has been built up based on NSOM ablation configuration. NSOM-LIBS is demonstrated with nanosecond pulsed laser excitation on Cr sample. Far-field collecting scheme by top objective lens was chosen as

  20. Defect creation by swift heavy ions: materials modifications in the electronic stopping power regime

    International Nuclear Information System (INIS)

    Toulemonde, M.

    1994-01-01

    The material modifications by swift heavy ions in the electronic stopping power regime are puzzling question: How the energy deposited on the electrons can induced material modifications? In order to answer to this question, the modifications induced in non-radiolytic materials are described and compared to the predictions. In first part the main experimental observations is presented taking into account the irradiation parameters. Then it is shown that the initial phases of the material are very important. Amorphous materials, whatever it is a metal, a semiconductor or an insulator, are till now all sensitive to the high electronic excitation induced by the slowing down of a swift heavy ion. All oxide materials, insulators or conductors, are also sensitive even the MgO, one of most famous exceptions. Crystalline metals or semiconductors are intermediate cases: some are insensitive like Cu and Si respectively while Fe and GeS are sensitive. The main feature is the different values of the electronic stopping power threshold of material modifications. The evolution of the damage creation is described showing that the damage morphology seems to be the same whatever the material is amorphous or crystalline. In second part a try of interpretation of the experimental results will be done on the behalf of the two following models: The Coulomb spike and the thermal spike models. It will be shown that there is some agreement with limited predictions made in the framework of the Coulomb spike model. But it appears that the thermal spike model can account for most of the experimental data using only one free parameter: The electron-phonon strength which is a physical characteristic of the irradiated material. (author). 4 figs., 1 tab., 64 refs

  1. Ab initio effective core potentials including relativistic effects and their application to the electronic structure calculations of heavy atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.S.

    1977-11-01

    The effects of the 4f shell of electrons and the relativity of valence electrons are compared. The effect of 4f shell (lanthanide contraction) is estimated from the numerical Hartree-Fock (HF) calculations of pseudo-atoms corresponding to Hf, Re, Au, Hg, Tl, Pb and Bi without 4f electrons and with atomic numbers reduced by 14. The relativistic effect estimated from the numerical Dirac-Hartree-Fock (DHF) calculations of those atoms is comparable in the magnitude with that of the 4f shell of electrons. Both are larger for 6s than for 5d or 6p electrons. The various relativistic effects on valence electrons are discussed in detail to determine the proper level of the approximation for the valence electron calculations of systems with heavy elements. An effective core potential system has been developed for heavy atoms in which relativistic effects are included in the effective potentials.

  2. Development of plant-based resist materials in electron beam lithography

    Science.gov (United States)

    Takei, Satoshi; Oshima, Akihiro; Yanamori, Naomi; Sekiguchi, Atsushi; Kozawa, Takahiro; Tagawa, Seiichi

    2011-04-01

    Electron beam lithography has great potential for future production of nano-imprint templates, light-emitting diodes, solar cell devices, actuators, biosensors, and micro electro mechanical systems (MEMS) where continued success ultimately requires improvements in current processing technologies. Electron beam lithography is promising for advancing multiple electronic applications due to several advantages such as high resolution, deep depth of focus, flexibility in material design, and assumable cost. This study presents progress in the development of a new plant-based resist material (TPU-EBR1) to achieve high exposure sensitivity and lower film thickness shrinkage by electron beam irradiation. Highly efficient crosslinking properties and high quality patterning line images were provided by specific process conditions of 30 keV electron beam lithography. Lower film thickness shrinkage of the newly developed TPU-EBR than that of the referenced acrylate type resist material is one of key to achieve EB patterning. The validity of our approach using the developed TPU-EBR was confirmed experimentally. In addition, this new approach was demonstrated to apply glucose and dextrin derivatives as the eco-friendlier compounds to the resist materials in micro and nano-patterning processes for environmentally-compatible electronic device fabrications.

  3. Decacyclene Trianhydride at Functional Interfaces: An Ideal Electron Acceptor Material for Organic Electronics

    DEFF Research Database (Denmark)

    de Oteyza, Dimas G.; García Lastra, Juan Maria; Toma, Francesca M.

    2016-01-01

    We report the interface energetics of decacyclene trianhydride (DTA) monolayers on top of two distinct model surfaces, namely, Au(111) and Ag(111). On the latter, combined valence band photoemission and X-ray absorption measurements that access the occupied and unoccupied molecular orbitals......, respectively, reveal that electron transfer from substrate to surface sets in. Density functional theory calculations confirm our experimental findings and provide an understanding not only of the photoemission and X-ray absorption spectral features of this promising organic semiconductor but also...

  4. A quasi-static algorithm that includes effects of characteristic time scales for simulating failures in brittle materials

    KAUST Repository

    Liu, Jinxing

    2013-04-24

    When the brittle heterogeneous material is simulated via lattice models, the quasi-static failure depends on the relative magnitudes of Telem, the characteristic releasing time of the internal forces of the broken elements and Tlattice, the characteristic relaxation time of the lattice, both of which are infinitesimal compared with Tload, the characteristic loading period. The load-unload (L-U) method is used for one extreme, Telem << Tlattice, whereas the force-release (F-R) method is used for the other, Telem T lattice. For cases between the above two extremes, we develop a new algorithm by combining the L-U and the F-R trial displacement fields to construct the new trial field. As a result, our algorithm includes both L-U and F-R failure characteristics, which allows us to observe the influence of the ratio of Telem to Tlattice by adjusting their contributions in the trial displacement field. Therefore, the material dependence of the snap-back instabilities is implemented by introducing one snap-back parameter γ. Although in principle catastrophic failures can hardly be predicted accurately without knowing all microstructural information, effects of γ can be captured by numerical simulations conducted on samples with exactly the same microstructure but different γs. Such a same-specimen-based study shows how the lattice behaves along with the changing ratio of the L-U and F-R components. © 2013 The Author(s).

  5. Review of the IAEA nuclear fuel cycle and material section activities connected with nuclear fuel including WWER fuel

    International Nuclear Information System (INIS)

    Sokolov, F.

    2001-01-01

    Program activities on Nuclear Fuel Cycle and Materials cover the areas of: 1) raw materials (B.1.01); 2) fuel performance and technology (B.1.02); 3) pent fuel (B.1.03); 4) fuel cycle issues and information system (B.1.04); 5) support to technical cooperation activities (B.1.05). The IAEA activities in fuel performance and technology in 2001 include organization of the fuel experts meetings and completion of the Co-ordinate Research Projects (CRP). The special attention is given to the advanced post-irradiation examination techniques for water reactor fuel and fuel behavior under transients and LOCA conditions. An international research program on modeling of activity transfer in primary circuit of NPP is finalized in 2001. A new CRP on fuel modeling at extended burnup (FUMEX II) has planed to be carried out during the period 2002-2006. In the area of spent fuel management the implementation of burnup credit (BUC) in spent fuel management systems has motivated to be used in criticality safety applications, based on economic consideration. An overview of spent fuel storage policy accounting new fuel features as higher enrichment and final burnup, usage of MOX fuel and prolongation of the term of spent fuel storage is also given

  6. 'Anomalous electron transport' with 'Giant Current Density' at room temperature observed with nanogranular materials

    International Nuclear Information System (INIS)

    Koops, Hans W.P.

    2013-01-01

    Focused electron beam induced deposition is a novel bottom up nano-structurization technology. An electron beam of high power density is used to generate nano- structures with dimensions > 20 nm, but being composed from amorphous or nanogranular materials with crystals of 2 to 5 nm diameter embedded in a Fullerene matrix. Those compounds are generated in general by secondary or low energy electrons in layers of inorganic, organic, organometallic compounds absorbed to the sample. Those are converted into nanogranular materials by the electron beam following chemical and physical laws, as given by 'Mother Nature'. Metals and amorphous mixtures of chemical compounds from metals are normal resistors, which can carry a current density J 2 . Nanogranular composites like Au/C or Pt/C with metal nanocrystals embedded in a Fullerene matrix have hopping conduction with 0-dimensional Eigen-value characteristics and show 'anomalous electron transport' and can carry 'Giant Current Densities' with values from > 1 MA/cm 2 to 0.1 GA/cm 2 without destruction of the materials. However the area connecting the nanogranular material with a metal with a 3-dimensional electron gas needs to be designed, that the flowing current is reduced to the current density values which the 3-D metal can support without segregation. The basis for a theoretical explanation of the phenomenon can be geometry quantization for Coulomb blockade, of electron surface orbitals around the nanocrystals, hopping conduction, and the limitation of the density of states for phonons in geometry confined non percolated granular materials with strong difference in mass and orientation. Several applications in electronics, signal generators, light sources, detectors, and solar energy harvesting are suggested. (author)

  7. VERB-4D simulations of Earths inner magnetosphere: Ring-current-to-radiation-belt electrons including adiabatic effects in a realistic magnetic field

    Science.gov (United States)

    Kellerman, Adam; Shprits, Yuri; Drozdov, Alexander; Aseeve, Nikita

    2016-04-01

    The Versatile Electron Radiation Belt 4D (VERB-4D) code models the dynamics of ring-current to radiation-belt electrons in Earth's magnetosphere. The code has been developed further to include a realistic magnetic field model, which allows one to model MLT-dependent adiabatic effects, in addition to other processes. Initial results are presented for storm- and non-storm time periods, demonstrating the role which adiabatic variations play on the observed electron dynamics.

  8. Development of high-brightness ultrafast electron microscope for studying nanoscale dynamics associated with strongly correlated materials

    Science.gov (United States)

    Tao, Zhensheng

    Strongly correlated-electron materials are a class of materials that exhibit numerous intriguing emergent phenomena, including metal-to-insulator transition, colossal magnetoresistance, high-temperature superconductivity, etc. These phenomena are beyond the reach of the conventional solid state physics, which is based on the band theory. Instead, strong electron-electron correlations are found to play important roles, which leads to complicated interplay between different degrees of freedoms (charge, lattice, spins...). In this thesis, ultrafast electron diffraction (UED) is used to investigate the photo-induced ultrafast structural dynamics of strongly correlated materials, among which VO2 is taken as an exemplar system, one that reveals the fundamental physics behind photo-induced phase transitions, electron-electron correlation on nanometer scales, and the electron-phonon coupling in this exotic class of materials. The phenomena presented here are expected to have more general significance as they may reflect the physics to which other strongly correlated materials also conform. In polycrystalline VO2 thin films, the structural changes resulting from photoexcitation with femtosecond laser pulses with different wavelengths are observed to lead to non-thermal phase transitions, which require less energy compared to the phase transitions induced by thermal excitation. The details of the structural change are extracted from the UED results revealing stepwise atomic movements after photoexcitation, which suggests the phase transition starts with a dilation of the correlated d electrons. On the other hand, the structural phase transition is found to be decoupled from the metal-to-insulator transition when the sample dimension is reduced to the sub-micrometer scale, which is attributed to the interface charge doping effects from different substrates. A new phase (M3, monoclinic metallic phase) is distinguished, which has not been discussed by the existing theoretical

  9. Simultaneous determination of electron beam profile and material response using self-consistent iterative method

    Science.gov (United States)

    Kandel, Yudhishthir; Denbeaux, Gregory

    2016-08-01

    We develop a novel iterative method to accurately measure electron beam shape (current density distribution) and monotonic material response as a function of position. A common method is to scan an electron beam across a knife edge along many angles to give an approximate measure of the beam profile, however such scans are not easy to obtain in all systems. The present work uses only an electron beam and multiple exposed regions of a thin film of photoresist to measure the complete beam profile for any beam shape, where the material response is characterized externally. This simplifies the setup of new experimental tools. We solve for self-consistent photoresist thickness loss response to dose and the electron beam profile simultaneously by optimizing a novel functional iteratively. We also show the successful implementation of the method in a real world data set corrupted by noise and other experimental variabilities.

  10. Charging and discharging characteristics of dielectric materials exposed to low- and mid-energy electrons

    Science.gov (United States)

    Coakley, P.; Kitterer, B.; Treadaway, M.

    1982-01-01

    Charging and discharging characteristics of dielectric samples exposed to 1-25 keV and 25-100 keV electrons in a laboratory environment are reported. The materials examined comprised OSR, Mylar, Kapton, perforated Kapton, and Alphaquartz, serving as models for materials employed on spacecraft in geosynchronous orbit. The tests were performed in a vacuum chamber with electron guns whose beams were rastered over the entire surface of the planar samples. The specimens were examined in low-impedance-grounded, high-impedance-grounded, and isolated configurations. The worst-case and average peak discharge currents were observed to be independent of the incident electron energy, the time-dependent changes in the worst case discharge peak current were independent of the energy, and predischarge surface potentials are negligibly dependent on incident monoenergetic electrons.

  11. Red phosphorescent organic light-emitting diodes using pyridine based electron transport type triplet host materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Soon Ok [Department of Polymer Science and Engineering, Dankook University, Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Lee, Jun Yeob, E-mail: leej17@dankook.ac.kr [Department of Polymer Science and Engineering, Dankook University, Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of)

    2011-05-16

    Research highlights: {yields} Pyridine based host material for red phosphorescent organic light emitting diode. {yields} Device optimization at low doping concentration of 2%. {yields} Simplified red phosphorescent organic light emitting diodes. - Abstract: Pyridine based electron transport type host materials were developed and their device performances were investigated according to doping concentration. The pyridine substituent was combined with a spirofluorenebenzofluorene core unit and a high quantum efficiency of 13.3% was achieved in red phosphorescent organic light-emitting diodes at a low doping concentration of 2%. A simple red device without any electron transport layer could be fabricated and a simple device without any electron transport layer showed better power efficiency than the standard device with an electron transport layer.

  12. Electronically and ionically conductive porous material and method for manufacture of resin wafers therefrom

    Energy Technology Data Exchange (ETDEWEB)

    Lin, YuPo J [Naperville, IL; Henry, Michael P [Batavia, IL; Snyder, Seth W [Lincolnwood, IL

    2008-11-18

    An electrically and ionically conductive porous material including a thermoplastic binder and one or more of anion exchange moieties or cation exchange moieties or mixtures thereof and/or one or more of a protein capture resin and an electrically conductive material. The thermoplastic binder immobilizes the moieties with respect to each other but does not substantially coat the moieties and forms the electrically conductive porous material. A wafer of the material and a method of making the material and wafer are disclosed.

  13. Electronically and ionically conductive porous material and method for manufacture of resin wafers therefrom

    Science.gov (United States)

    Lin, YuPo J [Naperville, IL; Henry, Michael P [Batavia, IL; Snyder, Seth W [Lincolnwood, IL

    2011-07-12

    An electrically and ionically conductive porous material including a thermoplastic binder and one or more of anion exchange moieties or cation exchange moieties or mixtures thereof and/or one or more of a protein capture resin and an electrically conductive material. The thermoplastic binder immobilizes the moieties with respect to each other but does not substantially coat the moieties and forms the electrically conductive porous material. A wafer of the material and a method of making the material and wafer are disclosed.

  14. Excitation and charge transfer in He+ + H collisions. A molecular approach including two-electron translation factors

    International Nuclear Information System (INIS)

    Errea, L.F.; Mendez, L.; Riera, A.

    1983-01-01

    In a previous paper we have pointed out that the common-translation-factor (CTF) method is the only one which, at present, and within the framework of the molecular model of atomic collisions, can be shown to be both convergent and computationally fast, even for many-electron systems. In this Communication we check that this second statement is correct, presenting, for the first time, a molecular calculation involving two-electron translation factors, for He + + H collisions. A careful study of the sensitivity of the calculated cross sections to the choice of the CTF is performed, and conclusions on that sensitivity are drawn, for several types of processes

  15. Excitation and charge transfer in He/sup +/ + H collisions. A molecular approach including two-electron translation factors

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Mendez, L.; Riera, A.

    1983-06-01

    In a previous paper we have pointed out that the common-translation-factor (CTF) method is the only one which, at present, and within the framework of the molecular model of atomic collisions, can be shown to be both convergent and computationally fast, even for many-electron systems. In this Communication we check that this second statement is correct, presenting, for the first time, a molecular calculation involving two-electron translation factors, for He/sup +/ + H collisions. A careful study of the sensitivity of the calculated cross sections to the choice of the CTF is performed, and conclusions on that sensitivity are drawn, for several types of processes.

  16. Transmission electron microscope interfaced with ion accelerators and its application to materials science

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hiroaki; Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Hojou, Kiichi; Furuno, Shigemi; Tsukamoto, Tetsuo

    1997-03-01

    We have developed the transmission/analytical electron microscope interfaced with two sets of ion accelerators (TEM-Accelerators Facility) at JAERI-Takasaki. The facility is expected to provide quantitative insights into radiation effects, such as damage evolution, irradiation-induced phase transformation and their stability, through in-situ observation and analysis under ion and/or electron irradiation. The TEM-Accelerators Facility and its application to materials research are reviewed. (author)

  17. Analysis of soft magnetic materials by electron backscatter diffraction as a powerful tool

    Science.gov (United States)

    Schuller, David; Hohs, Dominic; Loeffler, Ralf; Bernthaler, Timo; Goll, Dagmar; Schneider, Gerhard

    2018-04-01

    The current work demonstrates that electron backscatter diffraction (EBSD) is a powerful and versatile characterization technique for investigating soft magnetic materials. The properties of soft magnets, e.g., magnetic losses strongly depend on the materials chemical composition and microstructure, including grain size and shape, texture, degree of plastic deformation and elastic strain. In electrical sheet stacks for e-motor applications, the quality of the machined edges/surfaces of each individual sheet is of special interest. Using EBSD, the influence of the punching process on the microstructure at the cutting edge is quantitatively assessed by evaluating the crystallographic misorientation distribution of the deformed grains. Using an industrial punching process, the maximum affected deformation depth is determined to be 200 - 300 μm. In the case of laser cutting, the affected deformation depth is determined to be approximately zero. Reliability and detection limits of the developed EBSD approach are evaluated on non-affected sample regions and model samples containing different indentation test bodies. A second application case is the investigation of the recrystallization process during the annealing step of soft magnetic composites (SMC) toroids produced by powder metallurgy as a function of compaction pressure, annealing parameters and powder particle size. With increasing pressure and temperature, the recrystallized area fraction (e.g., grains with crystallographic misorientations size distributions. Here, large particles with coarse internal grain structures show a favorable recrystallization behavior which results in large bulk permeability of up to 600 - 700 and lower amount of residual misorientations (>3°).

  18. Methods of organization of SCORM-compliant teaching materials in electronic format

    Directory of Open Access Journals (Sweden)

    Jacek Marciniak

    2012-06-01

    Full Text Available This paper presents a method of organizing electronic teaching materials based on their role in the teaching process rather than their technical structure. Our method allows SCORM materials stored as e-learning courses („electronic books” to be subdivided and structured so that content can be used in multiple contexts. As a standard, SCORM defines rules for organizing content, but not how to divide and structure it. Our method uses UCTS nomenclature to divide content, define relationships between content entities, and aggregate those entities into courses. This allows content to be shared in different implementations of SCORM while guaranteeing that usability and consistency are maintained.

  19. Surveillance of selected post-caesarean infections based on electronic registries: validation study including post-discharge infections

    DEFF Research Database (Denmark)

    Leth, R A; Nørgaard, M; Uldbjerg, N

    2010-01-01

    ) within 30 days after caesarean section. We assessed the use of data from various electronic registries to identify patients with post-caesarean UTI and PWI classified according to a reference standard. The standard was based on information from medical records and self-reported data (questionnaire) using...

  20. Studies of novel magnetic materials and interfaces via electronic transport and superconducting spectroscopy

    Science.gov (United States)

    Zhang, Xiaohang

    The exploration of new paradigms for micro- and nanoelectronics has engendered several exciting new research fields including molecular electronics and spintronics. Two essential ingredients of the device structures are materials and interfaces. The overarching theme of this dissertation is the study of the (spin-dependent) electronic states and transport in novel magnetic materials and through molecular interfaces. These experiments are necessary first steps in ascertaining potential utilities in molecular electronic and spintronics applications. More importantly for this thesis, the materials and hybrid device structures provide a fertile ground for studying basic physics of magnetism, magnetotransport, and spin transport. In this dissertation, various techniques of superconducting spectroscopy have been used to investigate the spin-dependent electronic density of states of the thiol/Au molecular interface and the ferromagnetic semimetal EuB6. In addition, a fresh analysis of the electronic transport properties of EuB6 reveals a new type of nonlinear Hall effect intimately related to its magnetic state and culminates in a model that offers excellent quantitative understanding of the data and appears applicable to a wide varieties of magnetic materials. In order to directly probe possible induced magnetism at the thiol-gold interface, spin polarized tunneling measurements were performed on planar tunnel junctions incorporating a molecular monolayer of mercaptohexadecanoic acid [HS(CH2)15COOH] (MHA) between aluminum and gold electrodes. The Zeeman resolved tunneling spectra yield no measurable spin polarization at the thiol-gold interface, contrary to the expectations from the reported induced giant magnetic moments at the interface. On the other hand, variations in the resistance of the fabricated tunnel junctions with changing environmental conditions were consistently observed. A systematic investigation revealed that the effect is directly linked to the

  1. Interest in broadband dielectric spectroscopy to study the electronic transport in materials for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Badot, Jean-Claude, E-mail: jc.badot@chimie-paristech.fr [Institut de Recherche de Chimie Paris, UMR CNRS 8247, Réseau sur le Stockage Electrochimique de l' Energie (RS2E), Chimie Paris Tech, PSL*, 11 rue P. et M. Curie, 75231 Cedex 05 Paris (France); Lestriez, Bernard [Institut des Matériaux Jean Rouxel, UMR CNRS 6502, Université de Nantes, 2 rue de la Houssinière, BP32229, 44322 Nantes (France); Dubrunfaut, Olivier [GeePs | Group of electrical engineering – Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ Paris 06, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette CEDEX, Paris (France)

    2016-11-15

    Highlights: • Broadband dielectric spectroscopy measures the multiscale electronic conductivity from macroscopic to interatomic sizes. • There is an influence of the surface states on the electronic transfer of powdered materials (e.g. thin insulating layer of Li{sub 2}CO{sub 3} on LiNiO{sub 2} and carbon coating on LiFePO{sub 4}). • Electrical relaxations resulting from the interfacial polarizations at the different scales of the carbon black network are evidenced. - Abstract: Broadband dielectric spectroscopy (BDS) is used to measure complex permittivity and conductivity of conducting materials for lithium batteries at frequencies from a few Hz to several GHz with network and impedance analysers. Under the influence of an electric field, there will be charge density fluctuations in the conductor mainly due to electronic transfer. These fluctuations result in dielectric relaxations for frequencies below 100 GHz. The materials are compacted powders in which each element (particles, agglomerates of particles) can have different sizes and morphologies. In the present review, studies are reported on the influence of surface states in LiNiO{sub 2} (ageing and degradation in air) and LiFePO{sub 4} (carbon coating thin layer), and on a composite electrode based on the lithium trivanadate (Li{sub 1.1}V{sub 3}O{sub 8}) active material. The results have shown that the BDS technique is very sensitive to the different scales of materials architectures involved in electronic transport, from interatomic distances to macroscopic sizes.

  2. 500 C Electronic Packaging and Dielectric Materials for High Temperature Applications

    Science.gov (United States)

    Chen, Liang-yu; Neudeck, Philip G.; Spry, David J.; Beheim, Glenn M.; Hunter, Gary W.

    2016-01-01

    High-temperature environment operable sensors and electronics are required for exploring the inner solar planets and distributed control of next generation aeronautical engines. Various silicon carbide (SiC) high temperature sensors, actuators, and electronics have been demonstrated at and above 500C. A compatible packaging system is essential for long-term testing and application of high temperature electronics and sensors. High temperature passive components are also necessary for high temperature electronic systems. This talk will discuss ceramic packaging systems developed for high temperature electronics, and related testing results of SiC circuits at 500C and silicon-on-insulator (SOI) integrated circuits at temperatures beyond commercial limit facilitated by these high temperature packaging technologies. Dielectric materials for high temperature multilayers capacitors will also be discussed. High-temperature environment operable sensors and electronics are required for probing the inner solar planets and distributed control of next generation aeronautical engines. Various silicon carbide (SiC) high temperature sensors, actuators, and electronics have been demonstrated at and above 500C. A compatible packaging system is essential for long-term testing and eventual applications of high temperature electronics and sensors. High temperature passive components are also necessary for high temperature electronic systems. This talk will discuss ceramic packaging systems developed for high electronics and related testing results of SiC circuits at 500C and silicon-on-insulator (SOI) integrated circuits at temperatures beyond commercial limit facilitated by high temperature packaging technologies. Dielectric materials for high temperature multilayers capacitors will also be discussed.

  3. Comprehensive capacitance-voltage analysis including quantum effects for high-k interfaces on germanium and other alternative channel materials

    Science.gov (United States)

    Anwar, Sarkar R. M.

    High mobility alternative channel materials to silicon are critical to the continued scaling of metal oxide semiconductor (MOS) devices. However, before they can be incorporated into advanced devices, some major issues need to be solved. The high mobility materials suffer from lower allowable thermal budgets compared to Si (before desorption and defect formation becomes an issue) and the absence of a good quality native oxide has further increased the interest in the use of high-k dielectrics. However, the high interface state density and high electric fields at these semiconductor/high-k interfaces can significantly impact the capacitance-voltage (C-V) profile, and current C-V modeling software cannot account for these effects. This in turn affects the parameters extracted from the C-V data of the high mobility semiconductor/high-k interface, which are crucial to fully understand the interface properties and expedite process development. To address this issue, we developed a model which takes into account quantum corrections which can be applied to a number of these alternative channel materials including SixGe1-x, Ge, InGaAs, and GaAs. The C-V simulation using this QM correction model is orders of magnitude faster compared to a full band Schrodinger-Poisson solver. The simulated C-V is directly benchmarked to a self consistent Schrodinger-Poisson solution for each bulk semiconductor material, and from the benchmarking process the QM correction parameters are extracted. The full program, C-V Alternative Channel Extraction (CV ACE), incorporates a quantum mechanical correction model, along with the interface state density model, and can extract device parameters such as equivalent oxide thickness (EOT), doping density and flat band voltage (Vfb) as well as the interface state density profile using multiple measurements performed at different frequencies and temperatures, simultaneously. The program was used to analyze experimentally measured C-V profiles and the

  4. Temperature control and calibration issues in the growth, processing and characterization of electronic materials

    Science.gov (United States)

    Wilson, B. A.

    1989-01-01

    The temperature control and calibration issues encountered in the growth, processing, and characterization of electronic materials are summarized. The primary problem area is identified as temperature control during epitaxial materials growth. While qualitative thermal measurements are feasible and reproducibility is often achievable within a given system, absolute calibration is essentially impossible in many cases, precluding the possibility of portability from one system to another. The procedures utilized for thermal measurements during epitaxial growth are described, and their limitations discussed.

  5. Electronic and Vibrational Properties of Low-Dimensional Heterogeneous Systems: Materials and Device Perspectives

    Science.gov (United States)

    Neupane, Mahesh Raj

    heterostructure where two graphene layers are rotated by a relative angle, using molecular dynamic (MD) method. The MD method includes temperature dependent phonon anharmonicity which correctly predicts misorientation angle (θ) dependent low-energy breathing modes, and establishes a correlation between the experimentally observed low frequency Raman modes. Using a similar method, we have also conceptualized a phononic circuit using quasi-2D materials constructed from group IV elements of the periodic table, mainly carbon (C), Germenium (Ge) and Silicon (Si) by modifying the phononic bandgap (PBG). We successfully demonstrated the realization of various phononic interconnects such as nano-scaled phononic resonators, waveguides and switches by simultaneously introducing defects of different types at various locations on the 3C-SiC and 3C-GeSi surfaces. Finally, we have conceptualized a novel low power device called TMDC Excitonic Field Effect Transistor (TExFET), using other 2D materials namely, hexagonal boron nitride (h-BN) and Transition Metal Dichalcogenides (TMDC) by creating a TMDC/h-BN/TMDC heterstructure system. The characteristics of the TExFET device is explored with a combination of the variational principle and the mean field approximation. Our variational principle based calculation of the unscreened interlayer Coulombic forces in the TMDC/h-BN/TMDC system gives us an upper bound exciton gap in the order of 100 meV, mainly due to the isotropic electron and hole effective masses of the TMDC layers. Due to an effective exciton radius in the range of 2 nm, the TExFET could also be a device of choice for maintaining the device scaling trend. Further, when the effect of static screening between the layers is considered during self-consistent calculations, the interaction strength is reduced by ˜ 40% to 60 meV, producing an excitonic gap suitable for low temperature, low power device applications.

  6. Studies of the Response of the Prototype CMS Hadron Calorimeter, Including Magnetic Field Effects, to Pion, Electron, and Muon Beams

    CERN Document Server

    Abramov, V.V.; Akchurin, N.; Atanasov, I.; Baiatian, G.; Ball, A.; Banerjee, S.; de Barbaro, P.; Barnes, V.; Bencze, G.; Bodek, A.; Booke, M.; Budd, H.; Cremaldi, L.; Cushman, P.; Dugad, S.R.; Dimitrov, L.; Dyshkant, A.; Elias, J.; Evdokimov, V.N.; Fong, D.; Freeman, J.; Genchev, V.; Goncharov, P.I.; Green, D.; Gurtu, A.; Hagopian, V.; Iaydjiev, P.; Korneev, Yu.; Krinitsyn, A.; Krishnaswami, G.; Krishnaswamy, M.R.; Kryshkin, V.; Kunori, S.; Laasanen, A.; Lazic, D.; Levchuk, L.; Litov, L.; Mondal, N.K.; Moulik, T.; Narasimham, V.S.; Nemashkalo, A.; Onel, Y.; Petrov, P.; Petukhov, Yu.; Piperov, S.; Popov, V.; Reidy, J.; Ronzhin, A.; Ruchti, R.; Singh, J.B.; Shen, Q.; Sirunyan, A.; Skuja, A.; Skup, E.; Sorokin, P.; Sudhakar, K.; Summers, D.; Szoncso, F.; Tereshenko, S.I.; Timmermans, C.; Tonwar, S.C.; Turchanovich, L.; Tyukov, V.; Volodko, A.; Yukaev, A.; Zaitchenko, A.; Zatserklyaniy, A.; Korneev, Yu.

    2001-01-01

    We report on the response of a prototype CMS hadron calorimeter module to charged particle beams of pions, muons, and electrons with momenta up to 375 GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. The effects of a magnetic field of up to 3 Tesla on the response of the calorimeter to muons, electrons, and pions are presented, and the effects of an upstream lead tungstate crystal electromagnetic calorimeter on the linearity and energy resolution of the combined calorimetric system to hadrons are evaluated. The results are compared with Monte Carlo simulations and are used to optimize the choice of total absorber depth, sampling frequency, and longitudinal readout segmentation.

  7. R-matrix calculations for electron-impact excitation of C(+), N(2+), and O(3+) including fine structure

    Science.gov (United States)

    Luo, D.; Pradhan, A. K.

    1990-01-01

    The new R-matrix package for comprehensive close-coupling calculations for electron scattering with the first three ions in the boron isoelectronic sequence, the astrophysically significant C(+), N(2+), and O(3+), is presented. The collision strengths are calculated in the LS coupling approximation, as well as in pair-coupling scheme, for the transitions among the fine-structure sublevels. Calculations are carried out at a large number of energies in order to study the detailed effects of autoionizing resonances.

  8. Teacher-Made Tactile Science Materials with Critical and Creative Thinking Activities for Learners Including Those with Visual Impairments

    Science.gov (United States)

    Teske, Jolene K.; Gray, Phyllis; Kuhn, Mason A.; Clausen, Courtney K.; Smith, Latisha L.; Alsubia, Sukainah A.; Ghayoorad, Maryam; Rule, Audrey C.; Schneider, Jean Suchsland

    2014-01-01

    Gifted students with visual impairments are twice exceptional learners and may not evidence their advanced science aptitudes without appropriate accommodations for learning science. However, effective tactile science teaching materials may be easily made. Recent research has shown that when tactile materials are used with "all" students…

  9. 18 CFR 341.1 - Electronic filing of tariffs and related materials.

    Science.gov (United States)

    2010-04-01

    ... contents are true to the best knowledge and belief of the signer, and that the signer possesses full power... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Electronic filing of tariffs and related materials. 341.1 Section 341.1 Conservation of Power and Water Resources FEDERAL...

  10. 18 CFR 154.4 - Electronic filing of tariffs and related materials.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Electronic filing of tariffs and related materials. 154.4 Section 154.4 Conservation of Power and Water Resources FEDERAL... the contents are true to the best knowledge and belief of the signer, and that the signer possesses...

  11. Effect of interface of electronics devices constructed with different materials to X-ray

    International Nuclear Information System (INIS)

    Mu Weibing; Chen Panxun

    2003-01-01

    The behavior of X-ray nearby interface which is constructed with different materials is introduced in this paper. And the affect to electronics devices of this behavior is analyzed, the affect factors of four interfaces are calculated by Monte-Carlo method

  12. Method for morphological control and encapsulation of materials for electronics and energy applications

    Science.gov (United States)

    Ivanov, Ilia N.; Simpson, John T.

    2013-06-11

    An electronic device comprises a drawn glass tube having opposing ends, a semiconductive material disposed inside of the drawn glass tube, and a first electrode and a second electrode disposed at the opposing ends of the drawn glass tube. A method of making an electrical device comprises disposing a semiconductive material inside of a glass tube, and drawing the glass tube with the semiconductive material disposed therein to form a drawn glass tube. The method of making an electrical device also comprises disposing a first electrode and a second electrode on the opposing ends of the drawn glass tube to form an electric device.

  13. Analytical Electron Microscopy for Characterization of Fluid or Semi-Solid Multiphase Systems Containing Nanoparticulate Material

    Directory of Open Access Journals (Sweden)

    Nadejda B. Matsko

    2013-02-01

    Full Text Available The analysis of nanomaterials in pharmaceutical or cosmetic preparations is an important aspect both in formulation development and quality control of marketed products. Despite the increased popularity of nanoparticulate compounds especially in dermal preparations such as emulsions, methods and protocols of analysis for the characterization of such systems are scarce. This work combines an original sample preparation procedure along with different methods of analytical electron microscopy for the comprehensive analysis of fluid or semi-solid dermal preparations containing nanoparticulate material. Energy-filtered transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and high resolution imaging were performed on model emulsions and a marketed product to reveal different structural aspects of both the emulsion bulk phase and incorporated nanosized material. An innovative analytical approach for the determination of the physical stability of the emulsion under investigation is presented. Advantages and limitations of the employed analytical imaging techniques are highlighted.

  14. Electron-deficient anthraquinone derivatives as cathodic material for lithium ion batteries

    Science.gov (United States)

    Takeda, Takashi; Taniki, Ryosuke; Masuda, Asuna; Honma, Itaru; Akutagawa, Tomoyuki

    2016-10-01

    We studied the electronic and structural properties of electron-deficient anthraquinone (AQ) derivatives, Me4N4AQ and TCNAQ, and investigated their charge-discharge properties in lithium ion batteries along with those of AQ. Cyclic voltammogram, X-ray structure analysis and theoretical calculations revealed that these three acceptors have different features, such as different electron-accepting properties with different reduction processes and lithium coordination abilities, and different packing arrangements with different intermolecular interactions. These differences greatly affect the charge-discharge properties of lithium ion batteries that use these compounds as cathode materials. Among these compounds, Me4N4AQ showed a high charge/discharge voltage (2.9-2.5 V) with high cyclability (>65% of the theoretical capacity after 30 cycles; no decrease after 15 cycles). These results provide insight into more in-depth design principles for lithium ion batteries using AQ derivatives as cathodic materials.

  15. Molecule@MOF: A New Class of Opto-electronic Materials.

    Energy Technology Data Exchange (ETDEWEB)

    Talin, Albert Alec [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Reese E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Spataru, Dan Catalin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Leonard, Francois Leonard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); He, Yuping [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foster, Michael E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allendorf, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stavila, Vitalie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hopkins, Patrick E. [Univ. of Virginia, Charlottesville, VA (United States)

    2017-09-01

    Metal organic frameworks (MOFs) are extended, nanoporous crystalline compounds consisting of metal ions interconnected by organic ligands. Their synthetic versatility suggest a disruptive class of opto - electronic materials with a high degree of electrical tunability and without the property - degrading disorder of organic conductors. In this project we determined the factors controlling charge and energy transport in MOFs and evaluated their potential for thermoelectric energy conversion. Two strategies for a chieving electronic conductivity in MOFs were explored: 1) using redox active 'guest' molecules introduced into the pores to dope the framework via charge - transfer coupling (Guest@MOF), 2) metal organic graphene analogs (MOGs) with dispersive band structur es arising from strong electronic overlap between the MOG metal ions and its coordinating linker groups. Inkjet deposition methods were developed to facilitate integration of the guest@MOF and MOG materials into practical devices.

  16. Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Includes May 1979 edition and Supplements 1-15.

    Science.gov (United States)

    Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

    Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracts/indexed materials include all levels of government, private concerns, and educational…

  17. Far above bandgap photonics: attosecond dynamics of highly excited electrons in materials

    Science.gov (United States)

    Chen, Cong; Tao, Zhensheng; Carr, Adra; Szilvási, Tibor; Keller, Mark; Mavrikakis, Manos; Murnane, Margaret M.; Kapteyn, Henry C.

    2017-05-01

    Tabletop-scale coherent EUV generated through high-harmonic generation (HHG) produces light in the form of an attosecond pulse train that uniquely combines characteristics of good energy resolution (≍100-300meV) with sub-fs time resolution. This makes HHG an ideal source for studying the fastest dynamics in materials. Furthermore, using angle-resolved photoemission spectroscopy (ARPES), it is possible to extract detailed information about electron dynamics over the entire Brillouin zone. In recently published work, we combined HHG with ARPES to identify a sub-femtosecond excited-state lifetime for the first time. Photoemission occurs as a three-step process: 1) An electron is photoexcited from the valence band to far above the Fermi energy; 2) it transports to the surface, and 3) it overcomes the work function and exits. If the electron is promoted into a highlyexcited unoccupied band in the material (as opposed to a free-electron-like state), we observe the electron emission lifetime to increase in a measurable way—the Ni band 22 eV above the Fermi level has a lifetime of 212+/-30 attoseconds. Furthermore, by comparing photoemission from Cu and Ni, we reveal the influence of attosecond-timescale electron screening vs scattering by the electrons near the fermi surface. This work for the first time demonstrates the relevance of attosecond spectroscopy to the study of intrinsic properties and band structure in materials, as opposed to the strong-field induced dynamics studied extensively to-date.

  18. Theoretical study of the low-lying electronic states of magnesium sulfide cation including spin-orbit interaction

    Science.gov (United States)

    Chen, Peng; Wang, Ning; Li, Song; Chen, Shan-Jun

    2017-11-01

    Highly correlated ab initio calculations have been performed for an accurate determination of electronic structures and spectroscopic features for the low-lying electronic states of the MgS+ cation. The potential energy curves for the four Λ-S states correlating to the lowest dissociation asymptote are studied for the first time. Four Λ-S states split into nine Ω states through the spin-orbit coupling effect. Accurate spectroscopic constants are deduced for all bound states. The spin-orbit couplings and the transition dipole moments, as well as the PECs, are utilized to calculate Franck-Condon factors and radiative lifetimes of the vibrational levels. To verify our computational accuracy, analogous calculations for the ground state of MgS are also carried out, and our derived results are in reasonable agreement with available experimental data. In addition, photoelectron spectrum of MgS has been simulated. The predictive results are anticipated to serve as guidelines for further researches such as assisting laboratorial detections and analyzing observed spectrum.

  19. Electron-pinned defect-dipoles for high-performance colossal permittivity materials.

    Science.gov (United States)

    Hu, Wanbiao; Liu, Yun; Withers, Ray L; Frankcombe, Terry J; Norén, Lasse; Snashall, Amanda; Kitchin, Melanie; Smith, Paul; Gong, Bill; Chen, Hua; Schiemer, Jason; Brink, Frank; Wong-Leung, Jennifer

    2013-09-01

    The immense potential of colossal permittivity (CP) materials for use in modern microelectronics as well as for high-energy-density storage applications has propelled much recent research and development. Despite the discovery of several new classes of CP materials, the development of such materials with the required high performance is still a highly challenging task. Here, we propose a new electron-pinned, defect-dipole route to ideal CP behaviour, where hopping electrons are localized by designated lattice defect states to generate giant defect-dipoles and result in high-performance CP materials. We present a concrete example, (Nb+In) co-doped TiO₂ rutile, that exhibits a largely temperature- and frequency-independent colossal permittivity (> 10(4)) as well as a low dielectric loss (mostly density functional theory modelling suggests that 'triangular' In₂(3+)Vo(••)Ti(3+) and 'diamond' shaped Nb₂(5+)Ti(3+)A(Ti) (A = Ti(3+)/In(3+)/Ti(4+)) defect complexes are strongly correlated, giving rise to large defect-dipole clusters containing highly localized electrons that are together responsible for the excellent CP properties observed in co-doped TiO₂. This combined experimental and theoretical work opens up a promising feasible route to the systematic development of new high-performance CP materials via defect engineering.

  20. When Construction Material Traders Goes Electronic: Analysis of SMEs in Malaysian Construction Industry

    OpenAIRE

    Dzul Fahmi Nordin; Rosmini Omar

    2012-01-01

    This paper analyzed the perception of e-commerce application services by construction material traders in Malaysia. Five attributes were tested: usability, reputation, trust, privacy and familiarity. Study methodology consists of survey questionnaire and statistical analysis that includes reliability analysis, factor analysis, ANOVA and regression analysis. The respondents were construction material traders, including hardware stores in Klang Valley, Kuala Lumpur. Find...

  1. Electronic structure, excitation properties, and chemical transformations of extreme ultra-violet resist materials

    Science.gov (United States)

    Rangan, Sylvie; Bartynski, Robert A.; Narasimhan, Amrit; Brainard, Robert L.

    2017-07-01

    The electronic structure of extreme ultra violet resist materials and of their individual components, two polymers and two photoacid generators (PAGs), is studied using a combination of x-ray and UV photoemission spectroscopies, electron energy loss spectroscopy, and ab-initio techniques. It is shown that simple molecular models can be used to understand the electronic structure of each sample and describe the experimental data. Additionally, effects directly relevant to the photochemical processes are observed: low energy loss processes are observed for the phenolic polymer containing samples that should favor thermalization of electrons; PAG segregation is measured at the surface of the resist films that could lead to surface inhomogeneities; both PAGs are found to be stable upon irradiation in the absence of the polymer, contrasting with a high reactivity that can be followed upon x-ray irradiation of the full resist.

  2. NATO Advanced Research Workshop on Electron Correlation in New Materials and Nanosystems

    CERN Document Server

    Scharnberg, Kurt

    2007-01-01

    The articles collected in this book cover a wide range of materials with extraordinary superconducting and magnetic properties. For many of the materials studied, strong electronic correlations provide a link between these two phenomena which were long thought to be highly antagonistic. Both the progress in our understanding of fundamental physical processes and the advances made towards the development of devices are reported here. The materials studied come in a variety of forms and shapes from bulk to epitaxial films, nano- and heterostructures down to those involving single molecules and double quantum dots. In some cases the structuring serves the study of bulk properties. More often it is the change of these properties with nanostructuring and the properties of different materials in close proximity with each other that are of key interest because of possible application of these materials or heterostructures to quantum computing and spintronics.

  3. Nonlinear Thermo-mechanical Finite Element Analysis of Polymer Foam Cored Sandwich Structures including Geometrical and Material Nonlinearity

    DEFF Research Database (Denmark)

    Palleti, Hara Naga Krishna Teja; Thomsen, Ole Thybo; Taher, Siavash Talebi

    In this paper, polymer foam cored sandwich structures with fibre reinforced composite face sheets subjected to combined mechanical and thermal loads will be analysed using the commercial FE code ABAQUS® incorporating both material and geometrical nonlinearity. Large displacements and rotations...

  4. Differences in Tribological Behaviors upon Switching Fixed and Moving Materials of Tribo-pairs including Metal and Polymer.

    Science.gov (United States)

    Xu, Aijie; Tian, Pengyi; Wen, Shizhu; Guo, Fei; Hu, Yueqiang; Jia, Wenpeng; Dong, Conglin; Tian, Yu

    2017-10-12

    The coefficient of friction (COF) between two materials is usually believed to be an intrinsic property of the materials themselves. In this study, metals of stainless steel (304) and brass (H62), and polymers of polypropylene (PP) and polytetrafluoroethylene (PTFE) were tested on a standard ball-on-three-plates test machine. Significantly different tribological behaviors were observed when fixed and moving materials of tribo-pairs (metal/polymer) were switched. As an example, under the same applied load and rotating speed, the COF (0.49) between a rotating PP ball and three fixed H62 plates was approximately 2.3 times higher than that between switched materials of tribo-pairs. Meanwhile, the COF between H62 and PTFE was relatively stable. The unexpected tribological behaviors were ascribed to the thermal and mechanical properties of tribo-pairs. Theoretical analysis revealed that the differences in the maximum local temperature between switching the fixed and moving materials of tribo-pairs were consistent with the differences in the tested COF. This result indicated the precise prediction of the COF of two materials is complexcity, and that thermal and mechanical properties should be properly considered in designing tribo-pairs, because these properties may significantly affect tribological performance.

  5. A comparative study of materials and storage modes for human teeth in apicoectomy: scanning electron microscopy analysis.

    Science.gov (United States)

    De Conto, F; Ericson Flores, M; Cucco, C; Prates Soares Zerbinati, L; Dedavid, B A; Gerhardt De Oliveira, M

    2014-04-01

    Periradicular surgery is a procedure that includes surgical exposure of the diseased apex, root-end cavity preparation, and retrofilling of the root canal. The aim of this study was to compare the outcomes of periradicular surgery in vitro using different dental materials and storage methods for human teeth specimens. The sample comprised 60 human single-rooted teeth, divided into two groups according to mode of storage (hydrated or non-hydrated); each group was then subdivided by retrofilling material (mineral trioxide aggregate or resin-modified glass ionomer cement). Each specimen was analyzed by digital radiography and scanning electron microscopy (SEM). Quantitative assessment of the gap between the retrofilling material and dentin surface was conducted by observation of apical views (2000x magnification) of four areas of each specimen. The gap between retrofilling material and the internal dentin surface of the root was found to be significantly wider in hydrated teeth (P=0.002). Comparison of the two retrofilling materials showed that, regardless of tooth storage method, use of glass ionomer cement was associated with significantly wider gaps between the filling material and dentin surface (P=0.001). Comparisons of tooth storage mode versus retrofilling material showed a statistical interaction (P=0.009) between these factors. Mineral trioxide aggregate (MTA®) provided the best apical sealing, regardless of storage medium. Resin-modified glass ionomer cement (Vitremer®) was associated with substantially larger mean gap values when used in hydrated teeth.

  6. Integrating Hazardous Materials Characterization and Assessment Tools to Guide Pollution Prevention in Electronic Products and Manufacturing

    Science.gov (United States)

    Lam, Carl

    Due to technology proliferation, the environmental burden attributed to the production, use, and disposal of hazardous materials in electronics have become a worldwide concern. The major theme of this dissertation is to develop and apply hazardous materials assessment tools to systematically guide pollution prevention opportunities in the context of electronic product design, manufacturing and end-of-life waste management. To this extent, a comprehensive review is first provided on describing hazard traits and current assessment methods to evaluate hazardous materials. As a case study at the manufacturing level, life cycle impact assessment (LCIA)-based and risk-based screening methods are used to quantify chemical and geographic environmental impacts in the U.S. printed wiring board (PWB) industry. Results from this industrial assessment clarify priority waste streams and States to most effectively mitigate impact. With further knowledge of PWB manufacturing processes, select alternative chemical processes (e.g., spent copper etchant recovery) and material options (e.g., lead-free etch resist) are discussed. In addition, an investigation on technology transition effects for computers and televisions in the U.S. market is performed by linking dynamic materials flow and environmental assessment models. The analysis forecasts quantities of waste units generated and maps shifts in environmental impact potentials associated with metal composition changes due to product substitutions. This insight is important to understand the timing and waste quantities expected and the emerging toxic elements needed to be addressed as a consequence of technology transition. At the product level, electronic utility meter devices are evaluated to eliminate hazardous materials within product components. Development and application of a component Toxic Potential Indicator (TPI) assessment methodology highlights priority components requiring material alternatives. Alternative

  7. Electronic thermal conductivity of 2-dimensional circular-pore metallic nanoporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Cong-Liang, E-mail: huang198564@gmail.com; Lin, Zi-Zhen; Luo, Dan-Chen; Huang, Zun

    2016-09-07

    The electronic thermal conductivity (ETC) of 2-dimensional circular-pore metallic nanoporous material (MNM) was studied here for its possible applications in thermal cloaks. A simulation method based on the free-electron-gas model was applied here without considering the quantum effects. For the MNM with circular nanopores, there is an appropriate nanopore size for thermal conductivity tuning, while a linear relationship exists for this size between the ETC and the porosity. The appropriate nanopore diameter size will be about one times that of the electron mean free path. The ETC difference along different directions would be less than 10%, which is valuable when estimating possible errors, because the nanoscale-material direction could not be controlled during its application. Like nanoparticles, the ETC increases with increasing pore size (diameter for nanoparticles) while the porosity was fixed, until the pore size reaches about four times that of electron mean free path, at which point the ETC plateaus. The specular coefficient on the surface will significantly impact the ETC, especially for a high-porosity MNM. The ETC can be decreased by 30% with a tuning specular coefficient. - Highlights: • For metallic nanoporous materials, there is an appropriate pore size for thermal conductivity tuning. • ETC increases with increasing pore size until pore size reaches about four times EMFP. • The ETC difference between different directions will be less than 10%. • The ETC can be decreased by 30% with tuning specular coefficient.

  8. 3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy.

    Science.gov (United States)

    Hashimoto, Teruo; Thompson, George E; Zhou, Xiaorong; Withers, Philip J

    2016-04-01

    Mechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. 76 FR 16446 - Delphi Corporation Electronics And Safety Division Including On-Site Leased Workers From Acro...

    Science.gov (United States)

    2011-03-23

    ... firm. The workers are engaged in the production of various types of automobile components, including... Solutions, working on-site at the Kokomo, Indiana location of the subject firm. The intent of the Department...

  10. X-ray optics research for free electron lasers: study of material damage under extreme fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Kuba, Jaroslav E-mail: kuba@llnl.gov; Wootton, Alan; Bionta, R.M.; Shepherd, Ronnie; Fill, E.E.; Ditmire, Todd; Dyer, Gilliss; London, R.A.; Shlyaptsev, V.N.; Dunn, James; Booth, Rex; Bajt, Sasa; Smith, R.F.; Feit, M.D.; Levesque, Rick; McKernan, Mark

    2003-07-11

    Free electron lasers operating in the 0.1-1.5 nm wavelength range have been proposed for the Stanford Linear Accelerator Center (USA) and DESY (Germany). The unprecedented brightness and associated fluence (up to 30 J cm{sup -2}) predicted for pulses <300 fs pose new challenges for optical components. A criterion for optical component design is required, implying an understanding of X-ray--material interactions at these extreme conditions. In our experimental effort, the extreme conditions are simulated by the currently available sources ranging from optical lasers, through X-ray lasers (XRLs) at 14.7 nm down to K-alpha sources ({approx}0.15 nm). In this paper, we present an overview of our research project on X-ray--matter interaction, including both computer modeling and preliminary results from optical laser experiments, the COMET tabletop high brightness ps XRL and a K-alpha experimental campaign carried out at the JanUSP laser facility at the Lawrence Livermore National Laboratory.

  11. X-ray optics research for free electron lasers: study of material damage under extreme fluxes

    International Nuclear Information System (INIS)

    Kuba, Jaroslav; Wootton, Alan; Bionta, R.M.; Shepherd, Ronnie; Fill, E.E.; Ditmire, Todd; Dyer, Gilliss; London, R.A.; Shlyaptsev, V.N.; Dunn, James; Booth, Rex; Bajt, Sasa; Smith, R.F.; Feit, M.D.; Levesque, Rick; McKernan, Mark

    2003-01-01

    Free electron lasers operating in the 0.1-1.5 nm wavelength range have been proposed for the Stanford Linear Accelerator Center (USA) and DESY (Germany). The unprecedented brightness and associated fluence (up to 30 J cm -2 ) predicted for pulses <300 fs pose new challenges for optical components. A criterion for optical component design is required, implying an understanding of X-ray--material interactions at these extreme conditions. In our experimental effort, the extreme conditions are simulated by the currently available sources ranging from optical lasers, through X-ray lasers (XRLs) at 14.7 nm down to K-alpha sources (∼0.15 nm). In this paper, we present an overview of our research project on X-ray--matter interaction, including both computer modeling and preliminary results from optical laser experiments, the COMET tabletop high brightness ps XRL and a K-alpha experimental campaign carried out at the JanUSP laser facility at the Lawrence Livermore National Laboratory

  12. An in-situ analytical scanning and transmission electron microscopy investigation of structure-property relationships in electronic materials

    Science.gov (United States)

    Wagner, Andrew James

    As electronic and mechanical devices are scaled downward in size and upward in complexity, macroscopic principles no longer apply. Synthesis of three-dimensionally confined structures exhibit quantum confinement effects allowing, for example, silicon nanoparticles to luminesce. The reduction in size of classically brittle materials reveals a ductile-to-brittle transition. Such a transition, attributed to a reduction in defects, increases elasticity. In the case of silicon, elastic deformation can improve electronic carrier mobility by over 50%, a vital attribute of modern integrated circuits. The scalability of such principles and the changing atomistic processes which contribute to them presents a vitally important field of research. Beginning with the direct observation of dislocations and lattice planes in the 1950s, the transmission electron microscope has been a powerful tool in materials science. More recently, as nanoscale technologies have proliferated modern life, their unique ability to spatially resolve nano- and atomic-scale structures has become a critical component of materials research and characterization. Signals produced by an incident beam of high-energy electrons enables researchers to both image and chemically analyze materials at the atomic scale. Coherently and elastically-scattered electrons can be collected to produce atomic-scale images of a crystalline sample. New specimen stages have enabled routine investigation of samples heated up to 1000 °C and cooled to liquid nitrogen temperatures. MEMS-based transducers allow for sub-nm scale mechanical testing and ultrathin membranes allow study of liquids and gases. Investigation of a myriad of previously "unseeable" processes can now be observed within the TEM, and sometimes something new is found within the old. High-temperature annealing of pure a Si:H films leads to crystallization of the film. Such films provide higher carrier mobility compared to amorphous films, offering improved

  13. Perovskite Solar Cells with ZnO Electron-Transporting Materials.

    Science.gov (United States)

    Zhang, Peng; Wu, Jiang; Zhang, Ting; Wang, Yafei; Liu, Detao; Chen, Hao; Ji, Long; Liu, Chunhua; Ahmad, Waseem; Chen, Zhi David; Li, Shibin

    2018-01-01

    Perovskite solar cells (PSCs) have developed rapidly over the past few years, and the power conversion efficiency of PSCs has exceeded 20%. Such high performance can be attributed to the unique properties of perovskite materials, such as high absorption over the visible range and long diffusion length. Due to the different diffusion lengths of holes and electrons, electron transporting materials (ETMs) used in PSCs play a critical role in PSCs performance. As an alternative to TiO 2 ETM, ZnO materials have similar physical properties to TiO 2 but with much higher electron mobility. In addition, there are many simple and facile methods to fabricate ZnO nanomaterials with low cost and energy consumption. This review focuses on recent developments in the use of ZnO ETM for PSCs. The fabrication methods of ZnO materials are briefly introduced. The influence of different ZnO ETMs on performance of PSCs is then reviewed. The limitations of ZnO ETM-based PSCs and some solutions to these challenges are also discussed. The review provides a systematic and comprehensive understanding of the influence of different ZnO ETMs on PSCs performance and potentially motivates further development of PSCs by extending the knowledge of ZnO-based PSCs to TiO 2 -based PSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Graphene and Graphene Analogs toward Optical, Electronic, Spintronic, Green-Chemical, Energy-Material, Sensing, and Medical Applications.

    Science.gov (United States)

    Rezapour, M Reza; Myung, Chang Woo; Yun, Jeonghun; Ghassami, Amirreza; Li, Nannan; Yu, Seong Uk; Hajibabaei, Amir; Park, Youngsin; Kim, Kwang S

    2017-07-26

    This spotlight discusses intriguing properties and diverse applications of graphene (Gr) and Gr analogs. Gr has brought us two-dimensional (2D) chemistry with its exotic 2D features of density of states. Yet, some of the 2D or 2D-like features can be seen on surfaces and at interfaces of bulk materials. The substrate on Gr and functionalization of Gr (including metal decoration, intercalation, doping, and hybridization) modify the unique 2D features of Gr. Despite abundant literature on physical properties and well-known applications of Gr, spotlight works based on the conceptual understanding of the 2D physical and chemical nature of Gr toward vast-ranging applications are hardly found. Here we focus on applications of Gr, based on conceptual understanding of 2D phenomena toward 2D chemistry. Thus, 2D features, defects, edges, and substrate effects of Gr are discussed first. Then, to pattern Gr electronic circuits, insight into differentiating conducting and nonconducting regions is introduced. By utilizing the unique ballistic electron transport properties and edge spin states of Gr, Gr nanoribbons (GNRs) are exploited for the design of ultrasensitive molecular sensing electronic devices (including molecular fingerprinting) and spintronic devices. The highly stable nature of Gr can be utilized for protection of corrosive metals, moisture-sensitive perovskite solar cells, and highly environment-susceptible topological insulators (TIs). Gr analogs have become new types of 2D materials having novel features such as half-metals, TIs, and nonlinear optical properties. The key insights into the functionalized Gr hybrid materials lead to the applications for not only energy storage and electrochemical catalysis, green chemistry, and electronic/spintronic devices but also biosensing and medical applications. All these topics are discussed here with the focus on conceptual understanding. Further possible applications of Gr, GNRs, and Gr analogs are also addressed in a

  15. Extended automated separation techniques in destructive neutron activation analysis; application to various biological materials, including human tissues and blood

    International Nuclear Information System (INIS)

    Tjioe, P.S.; Goeij, J.J.M. de; Houtman, J.P.W.

    1976-09-01

    Neutron activation analysis may be performed as a multi-element and low-level technique for many important trace elements in biological materials, provided that post-irradiation chemical separations are applied. This paper describes a chemical separation consisting of automated procedures for destruction, distillation, and anion-chromatography. The system developed enables the determination of 14 trace elements in biological materials, viz. antimony, arsenic, bromine, cadmium, chromium, cobalt, copper, gold, iron, mercury, molybdenum, nickel, selenium, and zinc. The aspects of sample preparation, neutron irradiation, gamma-spectrum evaluation, and blank-value contribution are also discussed

  16. Electronic tongue-based discrimination of Korean rice wines (makgeolli) including prediction of sensory evaluation and instrumental measurements.

    Science.gov (United States)

    Kang, Bo-Sik; Lee, Jang-Eun; Park, Hyun-Jin

    2014-05-15

    A commercial electronic tongue was used to discriminate Korean rice wines (makgeolli) brewed from nine cultivars of rice with different amino acid and fatty acid compositions. The E-tongue was applied to establish prediction models with sensory evaluation or LC-MS/MS by partial least squares regression (PLSR). All makgeollis were classified into three groups by principal components analysis, and the separation pattern was affected by rice qualities and yeast fermentation. Makgeolli taste changed from the complicated comprising sweetness, saltiness, and umami to the uncomplicated, such as bitterness and then, sourness, with a decrease of amino acids and fatty acids in the rice. The quantitative correlation between E-tongue and sensory scores or LC-MS/MS by PLSR demonstrated that E-tongue could well predict most of the sensory attributes with relatively acceptable r(2), except for bitterness, but could not predict most of the chemical compounds responsible for taste attributes, except for ribose, lactate, succinate, and tryptophan. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. 10 CFR 170.31 - Schedule of fees for materials licenses and other regulatory services, including inspections, and...

    Science.gov (United States)

    2010-01-01

    ... production of accelerator-produced radionuclides. Application [Program Code(s): 03210] $6,500 4. Waste.... Users. Application $3,100 Inspections Full Cost C. Evaluation of security plans, route approvals, route... under the reciprocity provisions of 10 CFR 150.20. Application $1,800 17. Master materials licenses of...

  18. Analysis of alternative transportation methods for radioactive materials shipments including the use of special trains for spent fuel and wastes

    International Nuclear Information System (INIS)

    Smith, D.R.; Luna, R.E.; Taylor, J.M.

    1978-01-01

    Two studies were completed which evaluate the environmental impact of radioactive material transport. The first was a generic study which evaluated all radioactive materials and all transportation modes; the second addressed spent fuel and fuel-cycle wastes shipped by truck, rail and barge. A portion of each of those studies dealing with the change in impact resulting from alternative shipping methods is presented in this paper. Alternatives evaluated in each study were mode shifts, operational constraints, and, in generic case, changes in material properties and package capabilities. Data for the analyses were obtained from a shipper survey and from projections of shipments that would occur in an equilibrium fuel cycle supporting one hundred 1000-MW(e) reactors. Population exposures were deduced from point source radiation formulae using separation distances derived for scenarios appropriate to each shipping mode and to each exposed population group. Fourteen alternatives were investigated for the generic impact case. All showed relatively minor changes in the overall radiological impact. Since the radioactive material transport is estimated to be fewer than 3 latent cancer fatalities (LCF) for each shipment year (compared to some 300,000 yearly cancer fatalities or 5000 LCF's calculated for background radiation using the same radiological effects model), a 15% decrease caused by shifting from passenger air to cargo air is a relatively small effect. Eleven alternatives were considered for the fuel cycle/special train study, but only one produced a reduction in total special train baseline LCF's (.047) that was larger than 5%

  19. Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces.

    Science.gov (United States)

    Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon; Yeo, Woon-Hong

    2018-01-24

    Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas.

  20. Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces

    Directory of Open Access Journals (Sweden)

    Robert Herbert

    2018-01-01

    Full Text Available Flexible hybrid electronics (FHE, designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas.

  1. Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces

    Science.gov (United States)

    Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon

    2018-01-01

    Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas. PMID:29364861

  2. Perylene diimide-based materials for organic electronics and optical limiting applications

    Science.gov (United States)

    Hoban, Matty J.

    This dissertation described the investigation of the synthesis and characterization of new perylene diimide (PDI)-based photonic and electronic materials. In the first part of this thesis, PDI-based polynorbornenes, including PDI-grafted homopolymers and block-copolymers (BCPs) were designed, synthesized and characterized as alternative acceptors for fullerene derivatives in organic solar cells. It was found that the PDI pendants on the polymer side-chains affect pi-pi stacking with the neighboring PDIs, which has implications for the use of these materials for organic field-effect transistors (OFETs) and organic photovoltaic devices (OPVs). It should also be noted that the performance of solar cell based on the PDI-grafted polynorbornenes was poor, like most other solar cells using PDI acceptors. One of the major reasons could be the challenge in controlling the molecular alignment of the PDI-based materials, which leads to much lower electron mobilities in films compared to devices with fullerene-based acceptors. One of the PDI-grafted BCPs showed much better OPV performance compared to the other BCPs and respective homepolymer blends, presumably due to favorable morphology. In the second part of this thesis, the photo-induced charge-separation in blends of poly-3-hexyl-thiophene (P3HT) and various PDI derivatives have also been studied. Probing of long-lived photo-generated PDI radical anions and P3HT polarons provided insight on these photo-induced processes, including the relationship between the yields of charge photo-generation and energy difference between the first singlet excited state of P3HT and final charge-separated states. In the third part of this thesis, the use of photo-generated PDI radical-anion absorption was shown to be effective for optical limiting of nanosecond laser pulses between 650--800 nm. In Chapter 5, an effective approach for two-photon absorption (2PA)-induced optical limiting using donor-PDI dyads through which donors and

  3. Four-electron transfer tandem tetracyanoquinodimethane for cathode-active material in lithium secondary battery

    Science.gov (United States)

    Kurimoto, Naoya; Omoda, Ryo; Mizumo, Tomonobu; Ito, Seitaro; Aihara, Yuichi; Itoh, Takahito

    2018-02-01

    Quinoid compounds are important candidates of organic active materials for lithium-ion batteries. However, its high solubility to organic electrolyte solutions and low redox potential are known as their major drawbacks. To circumvent these issues, we have designed and synthesized a tandem-tetracyanoquinonedimethane type cathode-active material, 11,11,12,12,13,13,14,14-octacyano-1,4,5,8-anthradiquinotetramethane (OCNAQ), that has four redox sites per molecule, high redox potential and suppressed solubility to electrolyte solution. Synthesized OCNAQ has been found to have two-step redox reactions by cyclic voltammetry, and each step consists of two-electron reactions. During charge-discharge tests using selected organic cathode-active materials with a lithium metal anode, the cell voltages obtained from OCNAQ are higher than those for 11,11-dicyanoanthraquinone methide (AQM) as expected, due to the strong electron-withdrawing effect of the cyano groups. Unfortunately, even with the use of the organic active material, the issue of dissolution to the electrolyte solution cannot be suppressed completely; however, appropriate choice of the electrolyte solutions, glyme-based electrolyte solutions in this study, give considerable improvement of the cycle retention (98% and 56% at 10 and 100 cycles at 0.5C, respectively). The specific capacity and energy density obtained in this study are 206 mAh g-1 and 554 mWh g-1 with respect to the cathode active material.

  4. In Situ Transmission Electron Microscopy Characterization and Manipulation of Two-Dimensional Layered Materials beyond Graphene.

    Science.gov (United States)

    Luo, Chen; Wang, Chaolun; Wu, Xing; Zhang, Jian; Chu, Junhao

    2017-09-01

    Two-dimensional (2D) ultra-thin materials beyond graphene with rich physical properties and unique layered structures are promising for applications in electronics, chemistry, energy, and bioscience, etc. The interaction mechanisms among the structures, chemical compositions and physical properties of 2D layered materials are critical for fundamental nanosciences and the practical fabrication of next-generation nanodevices. Transmission electron microscopy (TEM), with its high spatial resolution and versatile external fields, is undoubtedly a powerful tool for the static characterization and dynamic manipulation of nanomaterials and nanodevices at the atomic scale. The rapid development of thin-film and precision microelectromechanical systems (MEMS) techniques allows 2D layered materials and nanodevices to be probed and engineered inside TEM under external stimuli such as thermal, electrical, mechanical, liquid/gas environmental, optical, and magnetic fields at the nanoscale. Such advanced technologies leverage the traditional static TEM characterization into an in situ and interactive manipulation of 2D layered materials without sacrificing the resolution or the high vacuum chamber environment, facilitating exploration of the intrinsic structure-property relationship of 2D layered materials. In this Review, the dynamic properties tailored and observed by the most advanced and unprecedented in situ TEM technology are introduced. The challenges in spatial, time and energy resolution are discussed also. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Development of Power Electronics Based Test Platform for Characterization and Testing of Magnetocaloric Materials

    Directory of Open Access Journals (Sweden)

    Deepak Elamalayil Soman

    2015-01-01

    Full Text Available Magnetocaloric effects of various materials are getting more and more interesting for the future, as they can significantly contribute towards improving the efficiency of many energy intensive applications such as refrigeration, heating, and air conditioning. Accurate characterization of magnetocaloric effects, exhibited by various materials, is an important process for further studies and development of the suitable magnetocaloric heating and cooling solutions. The conventional test facilities have plenty of limitations, as they focus only on the thermodynamic side and use magnetic machines with moving bed of magnetocaloric material or magnet. In this work an entirely new approach for characterization of the magnetocaloric materials is presented, with the main focus on a flexible and efficient power electronic based excitation and a completely static test platform. It can generate a periodically varying magnetic field using superposition of an ac and a dc magnetic field. The scale down prototype uses a customized single phase H-bridge inverter with essential protections and an electromagnet load as actuator. The preliminary simulation and experimental results show good agreement and support the usage of the power electronic test platform for characterizing magnetocaloric materials.

  6. Electron microscopic observation of fractures in carbonaceous materials produced by cracking of natural gas

    International Nuclear Information System (INIS)

    Blanchard, R.; Pelissier, J.; Pluchery, M.

    1964-01-01

    Circulating natural gas at 900 deg. C in an agglomerate of crushed graphite powder results in the formation of a compact material with high mechanical properties. Electron microscopic observation of fracture in resilience and compression specimens have been carried on, expecting a correlation between their mechanical properties and micrographic aspects. Fracture proceeds across the graphite grains and through the surrounding pyrocarbon as well. Heat-treated materials exhibit poorer mechanical properties: these changes could not be evidence in the micro-fractographic aspects of pyrocarbon; they may however account for differences in the fracture of the graphite grains. (authors) [fr

  7. Experimental and theoretical studies of picosecond laser interactions with electronic materials-laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Samuel S. [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    Lasers having picosecond and shorter pulse duration are receiving much attention due to their capabilities for direct-write micromachining on many materials with minimal substrate damage. Substantial progress has been made in the understanding of laser ablation processes, particularly the creation of plasmas that often shield the target and reduce the material processing efficiency at nanosecond time scales. However, a considerable challenge that still remains is the understanding of the underlying mechanisms during picosecond laser interactions with electronic solids. In this work we first study picosecond laser-induced electron emission from semiconductor surfaces. A theoretical model was set up based on carrier transport inside the semiconductor material during picosecond laser-semiconductor interactions. We demonstrate that nonequilibrium carrier dynamics plays a significant role for picosecond, as well as short nanosecond, laser induced electron emission from semiconductors. Photoelectric effect is found to be responsible for electron emission at low incident laser fluences, whereas thermionic emission is dominant at higher fluences. We have also performed experimental and theoretical studies on the formation and subsequent evolution of plasmas during laser-metal interactions at the picosecond time scale. Using picosecond time-resolved shadowgrams ahd interferograms, a novel type of plasma is observed, which has an electron density on the order of 1020cm-3.The origin of this picosecond plasma is attributed to gas breakdown, which is caused by laser-induced electron emission fi-om the target surface. After the laser pulse is completed, the longitudinal expansion of the plasma is suppressed. This suppression is found to result from an electric field above the target that prevents, after laser irradiation, fbrther movement of the electrons inside the plasma. Measurements of lateral plasma expansion indicate that the picosecond plasma may absorb

  8. Second crossover energy of insulating materials using stationary electron beam under normal incidence

    Energy Technology Data Exchange (ETDEWEB)

    Rau, E.I. [Institute of Microelectronics Technology of Russian Academy of Science, 142432 Chernogolovka, Moscow District (Russian Federation)], E-mail: rau@phys.msu.ru; Fakhfakh, S. [LaMaCop, Faculte des Sciences, Route Soukra km 3, BP 802, CP 3018 Sfax (Tunisia); Andrianov, M.V.; Evstafeva, E.N. [Institute of Microelectronics Technology of Russian Academy of Science, 142432 Chernogolovka, Moscow District (Russian Federation); Jbara, O. [UTAP/LASSI, EA 3802, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2 (France)], E-mail: omar.jbara@univ-reims.fr; Rondot, S.; Mouze, D. [UTAP/LASSI, EA 3802, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2 (France)

    2008-03-15

    The purpose of this paper is to give some aspects of charging effects on dielectric materials submitted to continuous electron beam irradiation in a scanning electron microscope (SEM). When the dielectric is irradiated continuously, the so-called total yield approach (TYA) used to predict the sign of the charge appeared on electron irradiated insulators fails because the charge accumulated in the dielectric interferes with the electrons emission processes. Based on previous experimental and theoretical works found in the literature, an analysis of the evolution of the electron yield curves {sigma} = f(E{sub 0}) of insulators during irradiation is given. The aim of this work is firstly to determine experimentally the second crossover energy E{sub 2C} under continuous electron irradiation (charging conditions) and secondly to demonstrate that the charge balance occurs at this beam energy and not at E{sub 2} the energy deduced from non-charging conditions (pulse primary electron beam experiments) as commonly asserted. It is however possible to apply the TYA by substituting the critical energy E{sub 2} for E{sub 2C}. The experimental procedure is based on simultaneous time dependent measurements of surface potential, leakage current and displacement current. The study underlines the difference between the landing energy of primary electrons E{sub L} at the steady state and the second crossover energy, E{sub 2C}, for charged samples. Some preliminary results are also obtained concerning the influence of the incident beam density on the energy E{sub 2C}. The samples used for this study are PMMA, polycrystalline silicone dioxide (p-SiO{sub 2}), polycrystalline alumina (p-Al{sub 2}O{sub 3}) and soda lime glass (SLG)

  9. Second crossover energy of insulating materials using stationary electron beam under normal incidence

    International Nuclear Information System (INIS)

    Rau, E.I.; Fakhfakh, S.; Andrianov, M.V.; Evstafeva, E.N.; Jbara, O.; Rondot, S.; Mouze, D.

    2008-01-01

    The purpose of this paper is to give some aspects of charging effects on dielectric materials submitted to continuous electron beam irradiation in a scanning electron microscope (SEM). When the dielectric is irradiated continuously, the so-called total yield approach (TYA) used to predict the sign of the charge appeared on electron irradiated insulators fails because the charge accumulated in the dielectric interferes with the electrons emission processes. Based on previous experimental and theoretical works found in the literature, an analysis of the evolution of the electron yield curves σ = f(E 0 ) of insulators during irradiation is given. The aim of this work is firstly to determine experimentally the second crossover energy E 2C under continuous electron irradiation (charging conditions) and secondly to demonstrate that the charge balance occurs at this beam energy and not at E 2 the energy deduced from non-charging conditions (pulse primary electron beam experiments) as commonly asserted. It is however possible to apply the TYA by substituting the critical energy E 2 for E 2C . The experimental procedure is based on simultaneous time dependent measurements of surface potential, leakage current and displacement current. The study underlines the difference between the landing energy of primary electrons E L at the steady state and the second crossover energy, E 2C , for charged samples. Some preliminary results are also obtained concerning the influence of the incident beam density on the energy E 2C . The samples used for this study are PMMA, polycrystalline silicone dioxide (p-SiO 2 ), polycrystalline alumina (p-Al 2 O 3 ) and soda lime glass (SLG)

  10. Electronic, structural, and optical properties of host materials for inorganic phosphors

    International Nuclear Information System (INIS)

    Alemany, Pere; Moreira, Ibério de P.R.; Castillo, Rodrigo; Llanos, Jaime

    2012-01-01

    Highlights: ► We performed a first-principles DFT study of the electronic structures of several wide band gap insulators (La 2 O 3 , La 2 O 2 S, Y 2 O 3 Y 2 O 2 S, La 2 TeO 6 , and Y 2 TeO 6 ) used as host materials for inorganic phosphors. ► The electronic, structural, and optical properties calculated for these compounds are in good agreement with the available experimental data. ► The electronic structure of the M 2 TeO 6 phases exhibits distinct features that could allow a fine tuning of the optical properties of luminescent materials obtained by doping with rare earth metals. - Abstract: A family of large gap insulators used as host materials for inorganic phosphors (La 2 O 3 , La 2 O 2 S, Y 2 O 3 , Y 2 O 2 S, La 2 TeO 6 , and Y 2 TeO 6 ) have been studied by first-principles DFT based calculations. We have determined electronic, structural, and optical properties for all these compounds both at the LDA and GGA levels obtaining, in general, a good agreement with available experimental data and previous theoretical studies. The electronic structure for the M 2 TeO 6 phases, addressed in this work for the first time, reveals some significant differences with respect to the other compounds, especially in the region of the lower conduction band, where the appearance of a group of four isolated oxygen/tellurium based bands below the main part of the La (Y) centered conduction band is predicted to lead to significant changes in the optical properties of the two tellurium containing compounds with respect to the rest of compounds in the series.

  11. Graphdiyne as Electrode Material: Tuning Electronic State and Surface Chemistry for Improved Electrode Reactivity.

    Science.gov (United States)

    Guo, Shuyue; Yan, Hailong; Wu, Fei; Zhao, Lijun; Yu, Ping; Liu, Huibiao; Li, Yuliang; Mao, Lanqun

    2017-12-05

    Graphdiyne (GDY) is recently synthesized two-dimensional carbon allotrope with hexagonal rings cross-linked by diacetylene through introducing butadiyne linkages (-C≡C-C≡C-) to form 18-C hexagons and is emerging to be fundamentally interesting and particularly useful in various research fields. In this study, we for the first time find that GDY can be used as an electrode material with reactivity tunable by electronic states and surface chemistry of GDY. To demonstrate this, GDY is oxidized into graphdiyne oxide (GDYO) that is then chemically and electrochemically reduced into chemically reduced GDYO (cr-GDYO) and electrochemically reduced GDYO (er-GDYO), respectively. Electrode reactivity of GDY and its derivatives (i.e., GDYO, cr-GDYO, and er-GDYO) is studied with hexaammineruthenium chloride ([Ru(NH 3 ) 6 ]Cl 3 ) and potassium ferricyanide (K 3 Fe(CN) 6 ) as redox probes. We find that electron transfer kinetics of the redox probes employed here at GDYs depends on the density of electronic state (DOS) and the synergetic effects of the surface chemistry as well as the hydrophilicity of the materials, and that the electron transfer kinetics at cr-GDYO and er-GDYO are faster than those at GDY and GDYO, and quite comparable with those at carbon nanotubes and graphene and its derivatives (i.e., GO, cr-GO, and er-GO). These properties, combined with the unique electronic and chemical structures of GDY, essentially enable GDY as a new kind of electrode material for fundamental studies on carbon electrochemistry and various electroanalytical applications.

  12. Electron transport in the two-dimensional channel material - zinc oxide nanoflake

    Science.gov (United States)

    Lai, Jian-Jhong; Jian, Dunliang; Lin, Yen-Fu; Ku, Ming-Ming; Jian, Wen-Bin

    2018-03-01

    ZnO nanoflakes of 3-5 μm in lateral size and 15-20 nm in thickness are synthesized. The nanoflakes are used to make back-gated transistor devices. Electron transport in the ZnO nanoflake channel between source and drain electrodes are investigated. In the beginning, we argue and determine that electrons are in a two-dimensional system. We then apply Mott's two-dimensional variable range hopping model to analyze temperature and electric field dependences of resistivity. The disorder parameter, localization length, hopping distance, and hopping energy of the electron system in ZnO nanoflakes are obtained and, additionally, their temperature behaviors and dependences on room-temperature resistivity are presented. On the other hand, the basic transfer characteristics of the channel material are carried out, as well, and the carrier concentration, the mobility, and the Fermi wavelength of two-dimensional ZnO nanoflakes are estimated.

  13. Advances in Ultrafast Control and Probing of Correlated-Electron Materials

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Simon [Univ. of Oxford (United Kingdom). Clarendon Lab.; Rini, Matteo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dhesi, Sarnjeet S. [Science and Technology Facilities Council (STFC), Harwell Campus, Oxford (United Kingdom). Diamond Light Source, Ltd.; Schoenlein, Robert W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Cavalleri, Andrea [Univ. of Oxford (United Kingdom). Clarendon Lab.; Univ. of Hamburg (Germany). Max Planck Research Dept. for Structural Dynamics

    2011-02-24

    Here in this paper, we present recent results on ultrafast control and probing of strongly correlated-electron materials. We focus on magnetoresistive manganites, applying excitation and probing wavelengths that cover the mid-IR to the soft X-rays. In analogy with near-equilibrium filling and bandwidth control of phase transitions, our approach uses both visible and mid-IR pulses to stimulate the dynamics by exciting either charges across electronic bandgaps or specific vibrational resonances. Lastly, x-rays are used to unambiguously measure the microscopic electronic, orbital, and structural dynamics. Our experiments dissect and separate the nonequilibrium physics of these compounds, revealing the complex interplay and evolution of spin, lattice, charge, and orbital degrees of freedoms in the time domain.

  14. Evaluation of the anti-inflammatory actions of various functional food materials including glucosamine on synovial cells.

    Science.gov (United States)

    Yamagishi, Yoshie; Someya, Akimasa; Imai, Kensuke; Nagao, Junji; Nagaoka, Isao

    2017-08-01

    The anti-inflammatory actions of glucosamine (GlcN) on arthritic disorders involve the suppression of inflammatory mediator production from synovial cells. GlcN has also been reported to inhibit the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. The present study aimed to determine the cooperative and anti‑inflammatory actions of functional food materials and evaluated the production of interleukin (IL)‑8 and phosphorylation of p38 MAPK in IL-1β-activated synovial cells, incubated with the combination of GlcN and various functional food materials containing L‑methionine (Met), undenatured type II collagen (UC‑II), chondroitin sulfate (CS), methylsulfonylmethane (MSM) and agaro-oligosaccharide (AO). The results indicated that Met, UC‑II, CS, MSM and AO slightly or moderately suppressed the IL-1β-stimulated IL‑8 production by human synovial MH7A cells. The same compounds further decreased the IL‑8 level lowered by GlcN. Similarly, they slightly suppressed the phosphorylation level of p38 MAPK and further reduced the phosphorylation level lowered by GlcN. These observations suggest a possibility that these functional food materials exert an anti‑inflammatory action (inhibition of IL‑8 production) in combination with GlcN by cooperatively suppressing the p38 MAPK signaling (phosphorylation).

  15. Synthesis and Sintering Behavior of Cordierite Prepared from Multi-Component Materials Including Alkaline-Earth Minerals

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Suk-In; Kim, Nam-Il; Lee, Sang-Jin [Mokpo National University, Muan (Korea, Republic of)

    2016-10-15

    Cordierite was synthesized using multi-component materials based on a talc-alumina-clay system. The cordierite sintered at 1360 °C showed a high relative density of 98.8% and a low thermal expansion coefficient of 1.59×10{sup -}6/°C. To study the effect of adding alkaline-earth minerals on the cordierite properties, petalite, potash-feldspar, and dicalcium phosphate were added to the synthesized cordierite. In the case of 9 wt% petalite or potash-feldspar addition, the cordierite was more densified; however, the thermal expansion coefficient and the pyroplasticity index were increased. In particular, a 5 μm thick self-glazed coating was formed with the addition of 9 wt% potash-feldspar. In the case of adding dicalcium phosphate, a glass phase was formed at low temperature and gas bubbles formed at high temperature above 1320 ℃. The cordierite synthesized using multi-component materials is expected to be employed as a material for high thermal shock, dense-microstructure flameware.

  16. Investigation of Basic Mechanisms of Radiation Effects in Carbon-Based Electronic Materials

    Science.gov (United States)

    2017-06-01

    Mechanisms of Radiation Effects in Carbon -Based Electronic Materials Distribution Statement A. Approved for public release; distribution is unlimited...MS-6201, FT BELVOIR, VA 22060-6201, IF YOUR ADDRESS IS INCORRECT, IF YOU WISH IT DELETED FROM THE DISTRIBUTION LIST, OR IF THE ADDRESSEE IS NO... DISTRIBUTION / AVAILABILITY STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18

  17. Electron-energy-loss spectral library and its application to materials science

    Energy Technology Data Exchange (ETDEWEB)

    Zaluzec, N.J.

    1983-09-01

    An electron energy loss spectral library can be an invaluable tool in materials research from a fundamental as well as a practical standpoint. Although it will not alleviate all the complications associated with quantification, this type of library can help to elucidate details of spectral profiles previously found intractable. This work was supported by the US Department of Energy. The author also wishes to express his gratitude to the organizing committee for partial financial support provided to attend this meeting.

  18. Materials and optimized designs for human-machine interfaces via epidermal electronics.

    Science.gov (United States)

    Jeong, Jae-Woong; Yeo, Woon-Hong; Akhtar, Aadeel; Norton, James J S; Kwack, Young-Jin; Li, Shuo; Jung, Sung-Young; Su, Yewang; Lee, Woosik; Xia, Jing; Cheng, Huanyu; Huang, Yonggang; Choi, Woon-Seop; Bretl, Timothy; Rogers, John A

    2013-12-17

    Thin, soft, and elastic electronics with physical properties well matched to the epidermis can be conformally and robustly integrated with the skin. Materials and optimized designs for such devices are presented for surface electromyography (sEMG). The findings enable sEMG from wide ranging areas of the body. The measurements have quality sufficient for advanced forms of human-machine interface. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Spin-Orbit Coupling and Novel Electronic States at the Interfaces of Heavy Fermion Materials

    Science.gov (United States)

    2016-02-22

    coupling, global phase diagram REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO 8. PERFORMING...regime in the correlated-electron “ global ” phase diagram of heavy fermion materials and, in addition, paving the way for interactions between the...SECURITY CLASSIFICATION OF: This report summarizes the progress made under the STIR grant. We completed the exploratory phase of a newly developed

  20. Investigation of the Optical and Electronic Properties of Crystalline Organic Materials

    Science.gov (United States)

    1990-06-14

    their crystal structures. Recently, we have measured the dielectric properties of an archetype crystalline organic material --- PTCDA6 , and found... archetype compound PTCDA in order to understand their optical and electronic properties. Crystalline organic semiconductor heterojunctions (HJs) have...Mendez, L.L. Chang, and Esaki, Phys. Rev., B26 1974(1982) 26 y. Shinozuka and M. Matsuura, Phys. Rev., B28, 487 8(1983) 2 7 E.O. Gobel, H. Jung , J

  1. Material discrimination using scattering and stopping of cosmic ray muons and electrons: Differentiating heavier from lighter metals as well as low-atomic weight materials

    Energy Technology Data Exchange (ETDEWEB)

    Blanpied, Gary; Kumar, Sankaran; Dorroh, Dustin; Morgan, Craig; Blanpied, Isabelle; Sossong, Michael; McKenney, Shawn; Nelson, Beth

    2015-06-01

    Reported is a new method to apply cosmic-ray tomography in a manner that can detect and characterize not only dense assemblages of heavy nuclei (like Special Nuclear Materials, SNM) but also assemblages of medium- and light-atomic-mass materials (such as metal parts, conventional explosives, and organic materials). Characterization may enable discrimination between permitted contents in commerce and contraband (explosives, illegal drugs, and the like). Our Multi-Mode Passive Detection System (MMPDS) relies primarily on the muon component of cosmic rays to interrogate Volumes of Interest (VOI). Muons, highly energetic and massive, pass essentially un-scattered through materials of light atomic mass and are only weakly scattered by conventional metals used in industry. Substantial scattering and absorption only occur when muons encounter sufficient thicknesses of heavy elements characteristic of lead and SNM. Electrons are appreciably scattered by light elements and stopped by sufficient thicknesses of materials containing medium-atomic-mass elements (mostly metals). Data include simulations based upon GEANT and measurements in the HMT (Half Muon Tracker) detector in Poway, CA and a package scanner in both Poway and Socorro NM. A key aspect of the present work is development of a useful parameter, designated the “stopping power” of a sample. The low-density regime, comprising organic materials up to aluminum, is characterized using very little scattering but a strong variation in stopping power. The medium-to-high density regime shows a larger variation in scattering than in stopping power. The detection of emitted gamma rays is another useful signature of some materials.

  2. [Theoretical studies of dynamics and correlations in heavy electron materials:]: Progress report, August 15, 1987-August 15, 1988

    International Nuclear Information System (INIS)

    1988-01-01

    This paper discusses progress in heavy electron research and high temperature superconductivity research. Particular topics discussed are: quadrupolar Kondo effect; coherence in the Anderson Lattice; Hall effect in heavy electron systems, suppression of supeconductivity by disorder in strongly correlated electronic materials; and charge transfer mechanisms for high temperature superconductivity

  3. Characterisation of β-tricalcium phosphate-based bone substitute materials by electron paramagnetic resonance spectroscopy

    Science.gov (United States)

    Matković, Ivo; Maltar-Strmečki, Nadica; Babić-Ivančić, Vesna; Dutour Sikirić, Maja; Noethig-Laslo, Vesna

    2012-10-01

    β-TCP based materials are frequently used as dental implants. Due to their resorption in the body and direct contact with tissues, in order to inactivate bacteria, fungal spores and viruses, they are usually sterilized by γ-irradiation. However, the current literature provides little information about effects of the γ-irradiation on the formation and stability of the free radicals in the bone graft materials during and after sterilization procedure. In this work five different bone graft substitution materials, composed of synthetic beta tricalcium phosphate (β-TCP) and hydroxyapatite (HAP) present in the market were characterized by electron paramagnetic resonance (EPR) spectroscopy, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Paramagnetic species Mn2+, Fe3+, trapped H-atoms and CO2- radicals were detected in the biphasic material (60% HAP, 40% β-TCP), while in β-TCP materials only Mn2+ andor trapped hydrogen atoms were detected. EPR analysis revealed the details of the structure of these materials at the atomic level. The results have shown that EPR spectroscopy is a method which can be used to improve the quality control of bone graft materials after syntering, processing and sterilization procedure.

  4. Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

    Directory of Open Access Journals (Sweden)

    Mambo Moyo

    2012-01-01

    Full Text Available Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed.

  5. Optical-electronic system for express analysis of mineral raw materials dressability by color sorting method

    Science.gov (United States)

    Alekhin, Artem A.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Petuhova, Darya B.

    2013-04-01

    Due to the depletion of solid minerals ore reserves and the involvement in the production of the poor and refractory ores a process of continuous appreciation of minerals is going. In present time at the market of enrichment equipment are well represented optical sorters of various firms. All these sorters are essentially different from each other by parameters of productivity, classes of particles sizes for processed raw, nuances of decision algorithm, as well as by color model (RGB, YUV, HSB, etc.) chosen to describe the color of separating mineral samples. At the same time there is no dressability estimation method for mineral raw materials without direct semi-industrial test on the existing type of optical sorter, as well as there is no equipment realizing mentioned dressability estimation method. It should also be note the lack of criteria for choosing of one or another manufacturer (or type) of optical sorter. A direct consequence of this situation is the "opacity" of the color sorting method and the rejection of its potential customers. The proposed solution of mentioned problems is to develop the dressability estimation method, and to create an optical-electronic system for express analysis of mineral raw materials dressability by color sorting method. This paper has the description of structure organization and operating principles of experimental model optical-electronic system for express analysis of mineral raw material. Also in this work are represented comparison results of the proposed optical-electronic system and the real color sorter.

  6. Material dependence of electron inelastic mean free paths at low energies

    International Nuclear Information System (INIS)

    Tanuma, S.; Powell, C.J.; Penn, D.R.

    1990-01-01

    We present and discuss electron inelastic mean free path (IMFP) data for aluminum and gold in the 50--200 eV range. These elements serve as examples of IMFP calculations that have been made for 50--2000 eV electrons in 31 materials (27 elements and 4 compounds). Substantial differences are found in the shapes of the IMFP versus energy curves for Al and Au and these can be understood in terms of the different inelastic scattering mechanisms in the two metals. The minimum IMFP value occurs at 40 eV in aluminum and at 120 eV in gold, a result which is consistent with the trends expected from free-electron IMFP calculations. This result differs, however, from that expected from the Seah and Dench attenuation length formula which shows essentially no material dependence at low energies. We have extended a general formula derived earlier to describe the calculated IMFPs over the 200--2000 eV energy range to give the IMFP dependences on material and energy from 50 to 2000 eV

  7. Modeling the Nonlinear, Strain Rate Dependent Deformation of Shuttle Leading Edge Materials with Hydrostatic Stress Effects Included

    Science.gov (United States)

    Goldberg, Robert K.; Carney, Kelly S.

    2004-01-01

    An analysis method based on a deformation (as opposed to damage) approach has been developed to model the strain rate dependent, nonlinear deformation of woven ceramic matrix composites, such as the Reinforced Carbon Carbon (RCC) material used on the leading edges of the Space Shuttle. In the developed model, the differences in the tension and compression deformation behaviors have also been accounted for. State variable viscoplastic equations originally developed for metals have been modified to analyze the ceramic matrix composites. To account for the tension/compression asymmetry in the material, the effective stress and effective inelastic strain definitions have been modified. The equations have also been modified to account for the fact that in an orthotropic composite the in-plane shear response is independent of the stiffness in the normal directions. The developed equations have been implemented into LS-DYNA through the use of user defined subroutines (UMATs). Several sample qualitative calculations have been conducted, which demonstrate the ability of the model to qualitatively capture the features of the deformation response present in woven ceramic matrix composites.

  8. In situ TEM/SEM electronic/mechanical characterization of nano material with MEMS chip

    International Nuclear Information System (INIS)

    Wang Yuelin; Li Tie; Zhang Xiao; Zeng Hongjiang; Jin Qinhua

    2014-01-01

    Our investigation of in situ observations on electronic and mechanical properties of nano materials using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) with the help of traditional micro-electro-mechanical system (MEMS) technology has been reviewed. Thanks to the stability, continuity and controllability of the loading force from the electrostatic actuator and the sensitivity of the sensor beam, a MEMS tensile testing chip for accurate tensile testing in the nano scale is obtained. Based on the MEMS chips, the scale effect of Young's modulus in silicon has been studied and confirmed directly in a tensile experiment using a transmission electron microscope. Employing the nanomanipulation technology and FIB technology, Cu and SiC nanowires have been integrated into the tensile testing device and their mechanical, electronic properties under different stress have been achieved, simultaneously. All these will aid in better understanding the nano effects and contribute to the designation and application in nano devices. (invited papers)

  9. Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

    Science.gov (United States)

    Friege, Henning

    2012-09-01

    For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

  10. Investigation of the Hydrogen Silsesquioxane (HSQ) Electron Resist as Insulating Material in Phase Change Memory Devices

    Science.gov (United States)

    Zhou, Jiao; Ji, Hongkai; Lan, Tian; Yan, Junbing; Zhou, Wenli; Miao, Xiangshui

    2015-01-01

    Phase change random access memory (PCRAM) affords many advantages over conventional solid-state memories due to its nonvolatility, high speed, and scalability. However, high programming current to amorphize the crystalline phase through the melt-quench process of PCRAM, known as the RESET current, poses a critical challenge and has become the most significant obstacle for its widespread commercialization. In this work, an excellent negative tone resist for high resolution electron beam lithography, hydrogen silsesquioxane (HSQ), has been investigated as the insulating material which locally blocks the contact between the bottom electrode and the phase change material in PCRAM devices. Fabrications of the highly scaled HSQ nanopore arrays (as small as 16 nm) are presented. The insulating properties of the HSQ material are studied, especially under e-beam exposure plus thermal curing. Some other critical issues about the thickness adjustment of HSQ films and the influence of the PCRAM electrode on electron scattering in e-beam lithography are discussed. In addition, the HSQ material was successfully integrated into the PCRAM devices, achieving ultra-low RESET current (sub-100 μA), outstanding on/off ratios (~50), and improved endurance at tens of nanometers.

  11. ELECTRONIC MEDIA LEARNING MATERIALS OF INDIRA GANDHI NATIONAL OPEN UNIVERSITY, INDIA: An Analytical Study

    Directory of Open Access Journals (Sweden)

    Manoj Roy. V.

    2013-10-01

    Full Text Available The establishment of the Indira Gandhi National Open University (IGNOU in 1985 has been a milestone in the growth of higher education in India. A very special feature of the University is that a composite of several instructional methods in practice are aimed at giving effective support to distance learners. Self-instructional print materials are the mainstay of the courseware. Besides this, at the support centres, the learners attend a few face-to-face counselling sessions and get access to audio-video materials stocked in the library. Gyandarshan and Gyanvani, the educational television and radio channels broadcast programmes with academic content. The curriculum-based audio-video programmes developed by the University are supplementary in nature. This blending of traditional printed self-learning materials with electronic courseware is a conscious decision of the University which is intended to enhance the quality and effectiveness of learning. Over the years, audio and video cassettes have made way for digital compact discs. Resultant development in information and communication technology heralded virtual campus initiatives of IGNOU, conspicuous among them being the creation of eGyanKosh, the digital repository of the learning materials of IGNOU. Nevertheless, majority of the academic programmes are not being provided audio video supports. The paper analyses the application of electronic media in IGNOU’s course delivery platform.

  12. Construction of electron accelerator for studying secondary emission in dielectric materials

    International Nuclear Information System (INIS)

    Hessel, R.

    1990-01-01

    An acelerator for the generation of low energy electrons (in the 0.4 to 20 keV range) was constructed. The accelerator is equipped with some devices especially designed for the investigation of the electrical properties of electron-irradiated dielectrics. In this work we have employed it for the study of the secondary electron emission of irradiated polymers. Reference is made to a method proposed by H. von Seggern (IEEE Trans. Nucl. Sci. NS-32, p.1503 (1985)] which was intended for the determination of the electron emission yield especially between the two cross-over points in a single run, here called the dynamical method. We have been able to prove that, contrary to expectation, this method does not give correct results over the entire emission curve. Rather it gives yield values which are too low by 25% in the region where the emission exhibits a maximum, due to the interaction between the electron emission process and the positive surface charge of the dielectric. However the method needs not to be dismissed entirely. As it is, it can be used advantageously for the precise determination of the energy of the second cross-over point. In addition, with the same set up, the method could be improved by replacing the continuous irradiation of the sample by a pulsed irradiation, leading to results essentially the same as those shown in the literature. Finally analysing the process of interaction between the positive charge of the dielectric and the mechanism of electron emission in several situations, we were able: I) to determine the maximum value and the average value of the escape depth of the emitted electrons; II) for a sample with a net positive charge, to show that the positive charge resides very near the surface of incidence; III) for a sample with a net negative charge, to show that the positive charge also resides near the surface while the (prevalent) negative charge resides in the bulk of the material. (author)

  13. Ecofriendly ethanol-developable processes for electron beam lithography using positive-tone dextrin resist material

    Science.gov (United States)

    Takei, Satoshi; Sugino, Naoto; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

    2017-07-01

    From the viewpoints of the utilization of agricultural resources and advanced use of biomass, this study is aimed at expanding the resolution limits of ecofriendly ethanol-developable processes for electron-beam lithography using a positive-tone dextrin resist material with high hydrophilicity on a cellulose-based underlayer. The images of 20-nm-hole and 40-nm-line patterns with an exposure dose of approximately 1800 µC/cm2 were provided by ecofriendly ethanol-developable processes instead of the common development processes using tetramethylammonium hydroxide and organic solvents. The CF4 etching selectivity of the positive-tone dextrin resist material was approximately 10% lower than that of the polymethyl methacrylate used as a reference resist material.

  14. Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

    International Nuclear Information System (INIS)

    Baranwal, R.; Burke, M.G.

    2003-01-01

    Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 (micro)m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large (∼ 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation

  15. Dynamic characterization of carboxymethyl cellulosic nonwoven material in the environmental scanning electron microscope

    International Nuclear Information System (INIS)

    Wei, Q.F.; Wang, X.Q.

    2005-01-01

    Carboxymethyl cellulosic fibers have been increasingly used in health care, agriculture and biomedical areas. The fundamental understanding of the material under different conditions is of importance in these applications. The use of environmental scanning electron microscopy for dynamic characterization of these nonwoven materials under different conditions has been explored in this study. Dynamic tensile testing under different humidity conditions was performed in a Philips XL 30 FEG-ESEM. The relative humidity in the microscope chamber was adjusted from 10% up to 100% by controlling the specimen temperature and the chamber pressure. The tensile testing was carried out on a stage that was placed in the microscope chamber. The studies under dynamic conditions have given new insight into the kinetics of structure formation, rearrangement and breakdown that are important for the processing and product development of these fiber materials

  16. Extreme-ultraviolet and electron beam lithography processing using water developable resist material

    Science.gov (United States)

    Takei, Satoshi

    2017-08-01

    In order to achieve the use of pure water in the developable process of extreme-ultraviolet and electron beam lithography, instead of conventionally used tetramethylammonium hydroxide and organic solvents, a water developable resist material was designed and developed. The water-developable resist material was derived from woody biomass with beta-linked disaccharide unit for environmental affair, safety, easiness of handling, and health of the working people. 80 nm dense line patterning images with exposure dose of 22 μC/cm2 and CF4 etching selectivity of 1.8 with hardmask layer were provided by specific process conditions. The approach of our water-developable resist material will be one of the most promising technologies ready to be investigated into production of medical device applications.

  17. Time-resolved THz studies of carrier dynamics in semiconductors, superconductors, and strongly-correlated electron materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaindl, Robert A.; Averitt, Richard D.

    2006-11-14

    materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials.A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field

  18. Theoretical investigation of five-layer waveguide structure including two left-handed material layers for refractometric applications

    Science.gov (United States)

    Alkanoo, Anas A.; Taya, Sofyan A.

    2018-03-01

    A slab waveguide structure consisting of five layers is studied for optical sensing applications. The five-layer waveguide structure has a guiding dielectric film, two left-handed material (LHM) layers and two dielectric layers as a substrate and a cladding. The dispersion relation and the sensitivity to any change in the index of the analyte layer are derived. The sensitivity is explored with different parameters of the structure. It is found that the sensitivity of the proposed structure can be significantly improved with the increase of the index of the guiding layer and the decrease of the permittivity of the LHM layers. Moreover, it can be also improved with the increase of the thickness of the LHM layers.

  19. End of FY2014 Report - Filter Measurement System for Nuclear Material Storage Canisters (Including Altitude Correction for Filter Pressure Drop)

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reeves, Kirk Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-24

    Two LANL FTS (Filter Test System ) devices for nuclear material storage canisters are fully operational. One is located in PF-4 ( i.e. the TA-55 FTS) while the other is located at the Radiation Protection Division’s Aerosol Engineering Facility ( i.e. the TA-3 FTS). The systems are functionally equivalent , with the TA-3 FTS being the test-bed for new additions and for resolving any issues found in the TA-55 FTS. There is currently one unresolved issue regarding the TA-55 FTS device. The canister lid clamp does not give a leak tight seal when testing the 1 QT (quart) or 2 QT SAVY lids. An adapter plate is being developed that will ensure a correct test configuration when the 1 or 2 QT SAVY lid s are being tested .

  20. A Multiscale Material Testing System for In Situ Optical and Electron Microscopes and Its Application.

    Science.gov (United States)

    Ye, Xuan; Cui, Zhiguo; Fang, Huajun; Li, Xide

    2017-08-04

    We report a novel material testing system (MTS) that uses hierarchical designs for in-situ mechanical characterization of multiscale materials. This MTS is adaptable for use in optical microscopes (OMs) and scanning electron microscopes (SEMs). The system consists of a microscale material testing module (m-MTM) and a nanoscale material testing module (n-MTM). The MTS can measure mechanical properties of materials with characteristic lengths ranging from millimeters to tens of nanometers, while load capacity can vary from several hundred micronewtons to several nanonewtons. The m-MTM is integrated using piezoelectric motors and piezoelectric stacks/tubes to form coarse and fine testing modules, with specimen length from millimeters to several micrometers, and displacement distances of 12 mm with 0.2 µm resolution for coarse level and 8 µm with 1 nm resolution for fine level. The n-MTM is fabricated using microelectromechanical system technology to form active and passive components and realizes material testing for specimen lengths ranging from several hundred micrometers to tens of nanometers. The system's capabilities are demonstrated by in-situ OM and SEM testing of the system's performance and mechanical properties measurements of carbon fibers and metallic microwires. In-situ multiscale deformation tests of Bacillus subtilis filaments are also presented.

  1. Radiation-Induced Graft Polymerization: Gamma Radiation and Electron Beam Technology for Materials Development

    International Nuclear Information System (INIS)

    Madrid, Jordan F.; Cabalar, Patrick Jay; Lopez, Girlie Eunice; Abad, Lucille V.

    2015-01-01

    The formation of functional hybrid materials by attaching polymer chains with advantageous tailored properties to the surface of a base polymer with desirable bulk character is an attractive application of graft copolymerization. Radiation-induced graft polymerization (RIGP) has been a popular approach for surface modification of polymers because of its merits over conventional chemical processes. RIGP, which proceeds primarily via free radical polymerization process, has the advantages such as simplicity, low cost, control over process and adjustment of the materials composition and structure. RIGP can be performed using either electron beam or gamma radiation and it can be applied to both synthetic and natural polymers. These merits make RIGP a popular research topic worldwide. Moreover, the materials synthesized and produced via RIGP has found applications, and were proposed to produce continuous impact, in the fields of medicine, agriculture, pollution remediation, rare earth and valuable metals recovery, fuel cell membrane synthesis and catalysis to name a few. From 2012 our group has performed electron beam and gamma radiation-induced graft polymerization of various monomers onto polymers of natural and synthetic origins (e.g. monomers - glycidyl methacrylate, styrene, acrylonitrile, N,N-dimethylaminoethyl methacrylate; base polymers – polyethylene/polypropylene nonwoven fabric, polypropylene nonwoven fabric pineapple fibers, cellulose nonwoven fabric microcrystalline cellulose). We tested these grafted materials for heavy metals (Pb, Ni, Cu) and organic molecule removal from aqueous solutions and E. coli activity (using reversible addition fragmentation chain transfer RAFT mediated grafting). The results clearly showed the success of materials modified via FIGP in these applications. Currently, we are studying the applications of grafted materials on treatment of waste waters from tanning industry, value addition to abaca nonwoven fabrics cell sheet

  2. Electron beam processing of materials-R and D and industrial utilization

    International Nuclear Information System (INIS)

    Sarma, K.S.S.

    2005-01-01

    The early sixties witnessed the beginning of Electron Beam (EB) processing of materials using high-energy electrons and has emerged as a well established technology, presently being adapted by the industry. The process and the processed materials showed definite and distinct advantages/characteristics over the available conventional methods. Even though the commercial exploitation started initially in polymer modifications for better (and suitable) performance through polymerization, cross-linking, degradation and grafting, the processing fields are now diverged to sterilization of health care, food irradiation, controlled defects in semiconductor devices and semi and/or precious stones, waste water/flue gas treatment etc. The availability of electron accelerators that operate as per the requirement of the industrial needs, easy maintenance, expertise availability etc brought the EB processing industry into a multi dollar business world wide. In USA and Japan there are more than 1200 accelerators currently operative in automobile tire, wire and cable and heat shrinkable industry. Output beam powers exceeding 400 kW with electron energy ranging from few hundred keV up to 10 MeV are made available to the industry. In BARC EB processing started with the 2MeV/20 kW electron accelerator and suitable processing techniques have been developed for applications like polymer cross linking (heat resistant LDPE O-rings, wire and cable insulation), color enhancement in precious stones (diamonds) on industrial scale and polymer curing, grafting, degradation on R and D/pilot scale. The commercial success of the process enabled the private cable industry to set up accelerators at their factories. On research and development front, the accelerator is being utilized to develop new polymer blends for high temperature applications, for solid and liquid waste treatment, polypropylene grafting experiments for uranium extraction from sea water, surface curing etc. This paper gives

  3. ESR dosimeter material properties of phenols compound exposed to radiotherapeutic electron beams

    Science.gov (United States)

    Gallo, Salvatore; Iacoviello, Giuseppina; Bartolotta, Antonio; Dondi, Daniele; Panzeca, Salvatore; Marrale, Maurizio

    2017-09-01

    There is a need for a sensitive dosimeter using Electron Spin Resonance spectroscopy for use in medical applications, since non-destructive read-out and dose archival could be achieved with this method. This work reports a systematic ESR investigation of IRGANOX ® 1076 exposed to clinical electron beams produced by a LINAC used for radiation therapy treatments. Recently, dosimetric features of this material were investigated for irradiation with 60Co γ -photons and neutrons in both pellet and film shape and have been found promising thanks to their high efficiency of radiation-matter energy transfer and radical stability at room temperature. Here the analysis of the dosimetric features of these ESR dosimeters exposed to clinical electron beams at energies of 7, 10 and 14 MeV, is described in terms of dependence on microwave power and modulation amplitude, response on dose, dependence on beam type, detection limits, and signal stability after irradiation. The analysis of the ESR signal as function of absorbed dose highlights that the response of this material is linear in the dose range investigated (1-13 Gy) and is independent of the beam energy. The minimum detectable dose is found to be smaller than 1 Gy. Comparison of electron stopping power values of these dosimeters with those of water and soft tissue highlights equivalence of the response to electron beams in the energy range considered. The signal intensity was monitored for 40 days after irradiation and for all energies considered and it shows negligible variations in the first 500 h after irradiation whereas after 1100 h the signal decay is only of about 4%. In conclusion, it is found that phenolic compounds possess good dosimetric features which make it useful as a sensitive dosimeter for medical applications.

  4. Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope.

    Science.gov (United States)

    Hieckmann, Ellen; Nacke, Markus; Allardt, Matthias; Bodrov, Yury; Chekhonin, Paul; Skrotzki, Werner; Weber, Jörg

    2016-05-28

    Extended defects such as dislocations and grain boundaries have a strong influence on the performance of microelectronic devices and on other applications of semiconductor materials. However, it is still under debate how the defect structure determines the band structure, and therefore, the recombination behavior of electron-hole pairs responsible for the optical and electrical properties of the extended defects. The present paper is a survey of procedures for the spatially resolved investigation of structural and of physical properties of extended defects in semiconductor materials with a scanning electron microscope (SEM). Representative examples are given for crystalline silicon. The luminescence behavior of extended defects can be investigated by cathodoluminescence (CL) measurements. They are particularly valuable because spectrally and spatially resolved information can be obtained simultaneously. For silicon, with an indirect electronic band structure, CL measurements should be carried out at low temperatures down to 5 K due to the low fraction of radiative recombination processes in comparison to non-radiative transitions at room temperature. For the study of the electrical properties of extended defects, the electron beam induced current (EBIC) technique can be applied. The EBIC image reflects the local distribution of defects due to the increased charge-carrier recombination in their vicinity. The procedure for EBIC investigations is described for measurements at room temperature and at low temperatures. Internal strain fields arising from extended defects can be determined quantitatively by cross-correlation electron backscatter diffraction (ccEBSD). This method is challenging because of the necessary preparation of the sample surface and because of the quality of the diffraction patterns which are recorded during the mapping of the sample. The spatial resolution of the three experimental techniques is compared.

  5. Experimental investigation about energy balance of electron emission from materials under electron impacts at low energy: application to silver, graphite and SiO2

    Science.gov (United States)

    Villemant, M.; Sarrailh, P.; Belhaj, M.; Garrigues, L.; Boniface, C.

    2017-12-01

    The energy balance measurement of electron emission at a wall submitted to electron impact at low incident energy is a topic of interest for miscellaneous technological applications. This article points out the experimental protocol, biases corrections and post-process needed to obtain reproducible and quantitative electron emission measurements. The measurements have been performed for incident electrons energy between 5 eV and 105 eV and for three samples materials: silver, graphite and SiO2. These measurements show that wall absorbs more energy at high incident electrons energy and that graphite absorbs more energy than silver, than SiO2. Results are presented for mono-energetic incident electron beam and for a Lambertian energy distribution. Analytical laws fitted from experimental results and applicable for modelling issue are proposed for a Lambertian distribution of incident electrons.

  6. Novel silicone materials for LED packaging and opto-electronics devices

    Science.gov (United States)

    Vanlathem, Eric; Norris, Ann W.; Bahadur, Maneesh; DeGroot, Jon; Yoshitake, Makoto

    2006-04-01

    Silicone based materials have attracted considerable attention from Light Emitting Diode (LED) manufacturers. In LEDs, silicones can function in several roles that include optical lenses, stress relieving encapsulants, mechanical protection and light path materials. The key attributes of silicones that make them attractive materials for high brightness (HB) LEDs include their excellent transparency in the UV-visible region, their non-discoloring behavior and their stable thermo-mechanical properties. The first part of this paper/presentation will describe recent silicone materials development efforts directed towards providing LED manufacturers with silicone materials solutions for LED device fabrication. Injection molding of novel silicone resin based materials will be discussed as a viable route for high throughput LED device manufacturing. For other portions of the light spectrum, specifically at telecom wavelengths, the performances of silicone based materials are also verified and this makes them attractive materials for numerous photonics device applications. The second part of this paper/presentation will describe recent demonstrations of siloxane for use as waveguides for datacom and telecom applications. A Variable Optical Attenuator (VOA) utilizing silicone based waveguides (exploiting dn/dT property) and an Optical Backplane built from silicone waveguides and out-of-plane mirrors built on glass and FR-4 substrates are discussed.

  7. A simple, low-cost conductive composite material for 3D printing of electronic sensors.

    Directory of Open Access Journals (Sweden)

    Simon J Leigh

    Full Text Available 3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes ('rapid prototyping' before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term 'carbomorph' and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes.

  8. A simple, low-cost conductive composite material for 3D printing of electronic sensors.

    Science.gov (United States)

    Leigh, Simon J; Bradley, Robert J; Purssell, Christopher P; Billson, Duncan R; Hutchins, David A

    2012-01-01

    3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes ('rapid prototyping') before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term 'carbomorph' and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes.

  9. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    mission. This workshop built on previous workshops and included three breakout sessions identifying scientific challenges in biology, biogeochemistry, catalysis, and materials science frontier areas of fundamental science that underpin energy and environmental science that would significantly benefit from ultrafast transmission electron microscopy (UTEM). In addition, the current status of time-resolved electron microscopy was examined, and the technologies that will enable future advances in spatio-temporal resolution were identified in a fourth breakout session.

  10. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

    Science.gov (United States)

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing

    2016-08-24

    With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology-a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

  11. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N.; Fang, Zhiqiang; Zhu, J. Y.; Henriksson, Gunnar; Himmel, Michael E.; Hu, Liangbing

    2016-08-24

    With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology--a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The

  12. Electronic and optical properties of strained graphene and other strained 2D materials: a review

    Science.gov (United States)

    Naumis, Gerardo G.; Barraza-Lopez, Salvador; Oliva-Leyva, Maurice; Terrones, Humberto

    2017-09-01

    This review presents the state of the art in strain and ripple-induced effects on the electronic and optical properties of graphene. It starts by providing the crystallographic description of mechanical deformations, as well as the diffraction pattern for different kinds of representative deformation fields. Then, the focus turns to the unique elastic properties of graphene, and to how strain is produced. Thereafter, various theoretical approaches used to study the electronic properties of strained graphene are examined, discussing the advantages of each. These approaches provide a platform to describe exotic properties, such as a fractal spectrum related with quasicrystals, a mixed Dirac-Schrödinger behavior, emergent gravity, topological insulator states, in molecular graphene and other 2D discrete lattices. The physical consequences of strain on the optical properties are reviewed next, with a focus on the Raman spectrum. At the same time, recent advances to tune the optical conductivity of graphene by strain engineering are given, which open new paths in device applications. Finally, a brief review of strain effects in multilayered graphene and other promising 2D materials like silicene and materials based on other group-IV elements, phosphorene, dichalcogenide- and monochalcogenide-monolayers is presented, with a brief discussion of interplays among strain, thermal effects, and illumination in the latter material family.

  13. Thermal management of electronics using phase change material based pin fin heat sinks

    International Nuclear Information System (INIS)

    Baby, R; Balaji, C

    2012-01-01

    This paper reports the results of an experimental study carried out to explore the thermal characteristics of phase change material based heat sinks for electronic equipment cooling. The phase change material (PCM) used in this study is n – eicosane. All heat sinks used in the present study are made of aluminium with dimensions of 80 × 62 mm 2 base with a height of 25 mm. Pin fins acts as the thermal conductivity enhancer (TCE) to improve the distribution of heat more uniformly as the thermal conductivity of the PCM is very low. A total of three different pin fin heat sink geometries with 33, 72 and 120 pin fins filled with phase change materials giving rise to 4%, 9% and 15% volume fractions of the TCE respectively were experimentally investigated. Baseline comparisons are done with a heat sink filled with PCM, without any fin. Studies are conducted for heat sinks on which a uniform heat load is applied at the bottom for the finned and unfinned cases. The effect of pin fins of different volume fractions with power levels ranging from 4 to 8 W corresponding to a heat flux range of 1. 59 to 3.17 kW/m 2 , was explored in this paper. The volume fraction of the PCM (PCM volume / (Total volume – fin volume)) is also varied as 0. 3, 0.6 and 1 to determine the effect of PCM volume on the overall performance of the electronic equipment.

  14. Electronic properties of novel topological quantum materials studied by angle-resolved photoemission spectroscopy (ARPES)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yun [Iowa State Univ., Ames, IA (United States)

    2016-12-17

    The discovery of quantum Hall e ect has motivated the use of topology instead of broken symmetry to classify the states of matter. Quantum spin Hall e ect has been proposed to have a separation of spin currents as an analogue of the charge currents separation in quantum Hall e ect, leading us to the era of topological insulators. Three-dimensional analogue of the Dirac state in graphene has brought us the three-dimensional Dirac states. Materials with three-dimensional Dirac states could potentially be the parent compounds for Weyl semimetals and topological insulators when time-reversal or space inversion symmetry is broken. In addition to the single Dirac point linking the two dispersion cones in the Dirac/Weyl semimetals, Dirac points can form a line in the momentum space, resulting in a topological node line semimetal. These fascinating novel topological quantum materials could provide us platforms for studying the relativistic physics in condensed matter systems and potentially lead to design of new electronic devices that run faster and consume less power than traditional, silicon based transistors. In this thesis, we present the electronic properties of novel topological quantum materials studied by angle-resolved photoemission spectroscopy (ARPES).

  15. Wide-gap layered oxychalcogenide semiconductors: Materials, electronic structures and optoelectronic properties

    International Nuclear Information System (INIS)

    Ueda, Kazushige; Hiramatsu, Hidenori; Hirano, Masahiro; Kamiya, Toshio; Hosono, Hideo

    2006-01-01

    Applying the concept of materials design for transparent conductive oxides to layered oxychalcogenides, several p-type and n-type layered oxychalcogenides were proposed as wide-gap semiconductors and their basic optical and electrical properties were examined. The layered oxychalcogenides are composed of ionic oxide layers and covalent chalcogenide layers, which bring wide-gap and conductive properties to these materials, respectively. The electronic structures of the materials were examined by normal/inverse photoemission spectroscopy and energy band calculations. The results of the examinations suggested that these materials possess unique features more than simple wide-gap semiconductors. Namely, the layered oxychalcogenides are considered to be extremely thin quantum wells composed of the oxide and chalcogenide layers or 2D chalcogenide crystals/molecules embedded in an oxide matrix. Observation of step-like absorption edges, large band gap energy and large exciton binding energy demonstrated these features originating from 2D density of states and quantum size effects in these layered materials

  16. Pure Material Vapor Source by Induction Heating Evaporator for an Electron Cyclotron Resonance Ion Source

    International Nuclear Information System (INIS)

    Matsui, Y.; Watanabe, T.; Satani, T.; Sato, F.; Kato, Y.; Iida, T.; Muramatsu, M.; Kitagawa, A.; Tanaka, K.; Yoshida, Y.

    2008-01-01

    Multiply charged iron ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with the induction coil which is made from bare molybdenum wire and surrounding the pure iron rod. We optimize the shape of induction heating coil and operation of rf power supply. We conduct experiment to investigate reproducibility and stability in the operation and heating efficiency. Induction heating evaporator produces pure material vapor, because materials directly heated by eddy currents have non-contact with insulated materials which are impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10 -4 to 10 -3 Pa. We measure temperature of iron rod and film deposition rate by depositing iron vapor to crystal oscillator. We confirm stability and reproducibility of evaporator enough to conduct experiment in ECR ion source. We can obtain required temperature of iron under maximum power of power supply. We are aiming the evaporator higher melting point material than iron.

  17. [Materiality Analysis of Health Plans Based on Stakeholder Engagement and the Issues Included at ISO 26000:2010].

    Science.gov (United States)

    Moyano Santiago, Miguel Angel; Rivera Lirio, Juana María

    2017-01-18

    Health plans of the Spanish autonomous communities can incorporate sustainable development criteria in its development. There have been no analysis or proposals about development and indicators. The goal is to add a contribution to help build better health plans aimed at sustainable development and help to manage economic, social and environmental impacts of health systems criteria. We used a variation of the RAND/UCLA or modified Delphi technique method. The process consisted of a bibliographical and context matters and issues related to health and social responsibility analysis based on ISO 26000: 2010. A survey by deliberately to a selection of 70 expert members of the identified stakeholders was carried out and a discussion group was held to determine the consensus on the issues addressed in the survey sample. The research was conducted in 2015. From the literature review 33 health issues included in ISO 26000:2010 were obtained. 7 survey proved relevant high consensus, 8 relevance and average consensus and 18 with less relevance and high level of dissent. The expert group excluded 4 of the 18 subjects with less consensus. 29 issues included 33 at work, divided into 7 subjects contained in the guide ISO 26000 of social responsibility, were relevant stakeholders regarding possible inclusion in health plans. Considering the direct relationship published by ISO (International Organization for Standardization) among the issues ISO 26000 and the economic, social and environmental indicators in GRI (Global Reporting Initiative) in its G4 version, a panel with monitoring indicators related to relevant issues were elaborated.

  18. Experimental Route to Scanning Probe Hot Electron Nanoscopy (HENs) Applied to 2D Material

    KAUST Repository

    Giugni, Andrea

    2017-06-09

    This paper presents details on a new experimental apparatus implementing the hot electron nanoscopy (HENs) technique introduced for advanced spectroscopies on structure and chemistry in few molecules and interface problems. A detailed description of the architecture used for the laser excitation of surface plasmons at an atomic force microscope (AFM) tip is provided. The photogenerated current from the tip to the sample is detected during the AFM scan. The technique is applied to innovative semiconductors for applications in electronics: 2D MoS2 single crystal and a p-type SnO layer. Results are supported by complementary scanning Kelvin probe microscopy, traditional conductive AFM, and Raman measurements. New features highlighted by HEN technique reveal details of local complexity in MoS2 and polycrystalline structure of SnO at nanometric scale otherwise undetected. The technique set in this paper is promising for future studies in nanojunctions and innovative multilayered materials, with new insight on interfaces.

  19. An Experimental Evaluation of Electron Beam Welded Thixoformed 7075 Aluminum Alloy Plate Material

    Directory of Open Access Journals (Sweden)

    Ava Azadi Chegeni

    2017-12-01

    Full Text Available Two plates of thixoformed 7075 aluminum alloy were joined using Electron Beam Welding (EBW. A post-welding-heat treatment (PWHT was performed within the semi-solid temperature range of this alloy at three temperatures, 610, 617 and 628 °C, for 3 min. The microstructural evolution and mechanical properties of EB welded plates, as well as the heat-treated specimens, were investigated in the Base Metal (BM, Heat Affected Zone (HAZ, and Fusion Zone (FZ, using optical microscopy, Scanning Electron Microscopy (SEM, EDX (Energy Dispersive X-ray Analysis, and Vickers hardness test. Results indicated that after EBW, the grain size substantially decreased from 67 µm in both BM and HAZ to 7 µm in the FZ, and a hardness increment was observed in the FZ as compared to the BM and HAZ. Furthermore, the PWHT led to grain coarsening throughout the material, along with a further increase in hardness in the FZ.

  20. Human alveolar macrophage responses to air pollution particulates are associated with insoluble components of coarse material, including particulate endotoxin.

    Science.gov (United States)

    Soukup, J M; Becker, S

    2001-02-15

    Inhalation of particulate matter in the ambient air has been shown to cause pulmonary morbidity and exacerbate asthma. Alveolar macrophage (AM) are essential for effective removal of inhaled particles and microbes in the lower airways. While some particles minimally effect AM function others inhibit antimicrobial activity or cause cytokine and growth factor production leading to inflammation and tissue remodeling. This study has investigated the effects of water soluble (s) and insoluble (is) components of Chapel Hill, North Carolina ambient particulate matter in the size ranges 0.1-2.5 microm (PM2.5) and 2.5-10 microm (PM10) diameter, on human AM IL-6, TNFalpha, and MCP-1 cytokine production and host defense mechanisms including phagocytosis and oxidant production. Cytokines were found to be induced by isPM10 to a much higher extent (>50-fold) than sPM10, which in turn stimulated production better than isPM2.5, while sPM2.5 was inactive. Previous studies have indicated that endotoxin (ETOX) is a component of sPM10 responsible for cytokine production. Here, it is shown that inhibition of isPM10-induced cytokine production was partially achieved with polymyxin B and LPS-binding protein (LBP), but not with a metal chelator, implicating ETOX as a cytokine-inducing moiety also in isPM10. In addition to inducing cytokines, exposure to isPM10, but not the other PM fractions, also inhibited phagocytosis and oxidant generation in response to yeast. This inhibition was ETOX independent. The decrease in host defenses may be the result of apoptosis in the AM population, which was also found to be specifically caused by isPM10. These results show that the functional capacity of AM is selectively modulated by insoluble components of coarse PM, including the biocontaminant ETOX.

  1. High-resolution monochromated electron energy-loss spectroscopy of organic photovoltaic materials.

    Science.gov (United States)

    Alexander, Jessica A; Scheltens, Frank J; Drummy, Lawrence F; Durstock, Michael F; Hage, Fredrik S; Ramasse, Quentin M; McComb, David W

    2017-09-01

    Advances in electron monochromator technology are providing opportunities for high energy resolution (10 - 200meV) electron energy-loss spectroscopy (EELS) to be performed in the scanning transmission electron microscope (STEM). The energy-loss near-edge structure in core-loss spectroscopy is often limited by core-hole lifetimes rather than the energy spread of the incident illumination. However, in the valence-loss region, the reduced width of the zero loss peak makes it possible to resolve clearly and unambiguously spectral features at very low energy-losses (photovoltaics (OPVs): poly(3-hexlythiophene) (P3HT), [6,6] phenyl-C 61 butyric acid methyl ester (PCBM), copper phthalocyanine (CuPc), and fullerene (C 60 ). Data was collected on two different monochromated instruments - a Nion UltraSTEM 100 MC 'HERMES' and a FEI Titan 3 60-300 Image-Corrected S/TEM - using energy resolutions (as defined by the zero loss peak full-width at half-maximum) of 35meV and 175meV, respectively. The data was acquired to allow deconvolution of plural scattering, and Kramers-Kronig analysis was utilized to extract the complex dielectric functions. The real and imaginary parts of the complex dielectric functions obtained from the two instruments were compared to evaluate if the enhanced resolution in the Nion provides new opto-electronic information for these organic materials. The differences between the spectra are discussed, and the implications for STEM-EELS studies of advanced materials are considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Electronic, structural, and optical properties of host materials for inorganic phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Alemany, Pere, E-mail: p.alemany@ub.edu [Departament de Quimica Fisica and Institut de Quimica Teorica i Computacional (IQTCUB), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Moreira, Iberio de P.R. [Departament de Quimica Fisica and Institut de Quimica Teorica i Computacional (IQTCUB), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Castillo, Rodrigo [Departamento de Quimica, Universidad Catolica del Norte, Avda. Angamos 0610, Casilla 1280, Antofagasta (Chile); Llanos, Jaime, E-mail: jllanos@ucn.cl [Departamento de Quimica, Universidad Catolica del Norte, Avda. Angamos 0610, Casilla 1280, Antofagasta (Chile)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer We performed a first-principles DFT study of the electronic structures of several wide band gap insulators (La{sub 2}O{sub 3}, La{sub 2}O{sub 2}S, Y{sub 2}O{sub 3} Y{sub 2}O{sub 2}S, La{sub 2}TeO{sub 6}, and Y{sub 2}TeO{sub 6}) used as host materials for inorganic phosphors. Black-Right-Pointing-Pointer The electronic, structural, and optical properties calculated for these compounds are in good agreement with the available experimental data. Black-Right-Pointing-Pointer The electronic structure of the M{sub 2}TeO{sub 6} phases exhibits distinct features that could allow a fine tuning of the optical properties of luminescent materials obtained by doping with rare earth metals. - Abstract: A family of large gap insulators used as host materials for inorganic phosphors (La{sub 2}O{sub 3}, La{sub 2}O{sub 2}S, Y{sub 2}O{sub 3}, Y{sub 2}O{sub 2}S, La{sub 2}TeO{sub 6}, and Y{sub 2}TeO{sub 6}) have been studied by first-principles DFT based calculations. We have determined electronic, structural, and optical properties for all these compounds both at the LDA and GGA levels obtaining, in general, a good agreement with available experimental data and previous theoretical studies. The electronic structure for the M{sub 2}TeO{sub 6} phases, addressed in this work for the first time, reveals some significant differences with respect to the other compounds, especially in the region of the lower conduction band, where the appearance of a group of four isolated oxygen/tellurium based bands below the main part of the La (Y) centered conduction band is predicted to lead to significant changes in the optical properties of the two tellurium containing compounds with respect to the rest of compounds in the series.

  3. Electrochemical gating: A method to tune and monitor the (opto)electronic properties of functional materials

    Energy Technology Data Exchange (ETDEWEB)

    Vanmaekelbergh, D.; Houtepen, A.J.; Kelly, J.J. [Condensed Matter and Interfaces, Debye Institute, Utrecht University, Princetonplein 1, 3508 TA Utrecht (Netherlands)

    2007-12-20

    Electrochemical polarization of a crystalline, polymeric or nanoporous system or a single molecule may change the density of charge carriers in a controlled way, and hence the optical and electrical properties. If the system has two contacts, its electronic conductivity can be measured in situ as a function of the charge carrier density that is varied by the electrochemical potential. This is called electrochemical gating. Such investigations can reveal the nature of the charge carriers (mobile or localized) and the mechanism of electronic conduction. Here, we present a brief review of a number of systems including inorganic crystals, polymers, nanoporous quantum-dot solids, and single molecules for which electrochemical gating was used successfully in the study of the electronic properties. (author)

  4. Oligothiophene-S,S-dioxides as a class of electron-acceptor materials for organic photovoltaics

    International Nuclear Information System (INIS)

    Camaioni, N.; Ridolfi, G.; Fattori, V.; Favaretto, L.; Barbarella, G.

    2004-01-01

    Oligothiophene-S,S-dioxides are proposed as electron acceptors materials in organic blended photovoltaic devices. Photoinduced charge transfer is demonstrated in blends between a regioregular poly(3-hexylthiophene) and the oligomers, via photoluminescence spectroscopy. The enhanced photovoltaic performance exhibited by the blended cells, with respect to that of pristine devices in which the polymer is the active layer, represents further evidence for exciton dissociation. An increase of the power conversion efficiency up to sixty-fold is achieved by blending the polymer with the oligothiophene-S,S-dioxides

  5. Transient cooling of electronics using phase change material (PCM)-based heat sinks

    International Nuclear Information System (INIS)

    Kandasamy, Ravi; Wang Xiangqi; Mujumdar, Arun S.

    2008-01-01

    Use of a phase change material (PCM)-based heat sink in transient thermal management of plastic quad flat package (QFP) electronic devices was investigated experimentally and numerically. Results show that increased power inputs enhance the melting rate as well as the thermal performance of the PCM-based heat sinks until the PCM is fully melted. A three-dimensional computational fluid dynamics model was proposed to simulate the problem and demonstrated good agreement with experimental data. Results indicate the potential for PCM-based heat sinks for use in intermittent-use devices

  6. Evaluation of surgical implantation of electronic tags in European eel and effects of different suture materials

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn; Westerberg, Håkan

    2013-01-01

    Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire....... Antibacterial treatment had no effect on inflammation or healing rates. After 6 months, the tag started to become expelled through the incision in five fish (12%). The internal reaction appeared stronger around the floats, suggesting that the coating material of the floats created a tissue reaction, which...... should be further investigated. Intraperitoneal implantation appears to be a suitable tagging method for European silver eel, and it is recommended to close incisions using permanent monofilament sutures...

  7. Josephson junction electronics: Materials issues and fabrication techniques. Metallurgy, fabrication, and applications

    International Nuclear Information System (INIS)

    Beasley, M.R.

    1981-01-01

    The main body of this chapter is organized as follows. In Section II we review the device principles that underlie the operation of superconducting electronic devices. The emphasis is on defining the most critical and characteristic materials issues and problems. In Section III we discuss the state of the art in the LSI circuit technology being developed for the Josephson computer. The problems associated with thermally-induced stresses in Josephson junctions are discussed in Section IV, and the importance and current understanding of the science of tunneling between superconductors is discussed in Section V. Finally, in Section VI we attempt to look ahead and discuss current work on advanced superconducting materials and devices

  8. Chemistry of green encapsulating molding compounds at interfaces with other materials in electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Scandurra, A.; Zafarana, R.; Tenya, Y.; Pignataro, S

    2004-07-31

    The interface chemistry between encapsulating epoxy phenolic molding compound (EMC) containing phosphorous based organic flame retardant (the so called 'green materials') and copper oxide-hydroxide and aluminum oxide-hydroxide surfaces have been studied in comparison with 'conventional' EMC containing bromine and antimony as flame retardant. These green materials are designed to reduce the presence of toxic elements in the electronic packages and, consequently, in the environment. For the study were used a Scanning Acoustic Microscopy for delamination measurements, a dynamometer for the pull strength measurements and an ESCA spectrometer for chemical analysis of the interface. The general behavior of the green compound in terms of delamination, adhesion, and corrosion is found better or at least comparable than that of the conventional EMC.

  9. Surface modification of polymeric materials using ultra low energy electron beam irradiation

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Shiraki, Fumiya; Fujita, Hajime; Washio, Masakazu

    2011-01-01

    An ultra low energy electron beam (UL-EB) was used to irradiate various polymeric materials such as fluorinated polymers and a polyimide under an oxygen-free atmosphere. After the irradiation of the polyimide, the change in the thermal properties was measured by DSC and TGA. The surface modification of fluorinated polymers was demonstrated by use of styrene grafting by the preirradiation grafting method. By the use of UL-EB irradiation it was possible to facilitate styrene monomer grafting onto the surface of fluorinated polymers without losing their material characteristics. Moreover, in the case of the polyimide (Kapton TM ), which has excellent radiation resistance, the glass transition temperature was improved by about 20 o C by irradiation up to 40 MGy within 1 h.

  10. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    Science.gov (United States)

    Rodríguez-Fernández, Luis

    2010-09-01

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  11. Cellular transport of subretinal material into choroidal and scleral blood vessels: an electron microscopic study.

    Science.gov (United States)

    Peters, S; Kayatz, P; Kociok, N; Heimann, K; Schraermeyer, U

    1999-12-01

    The fate of indigestible material injected into the subretinal space of rats was investigated. The non-toxic dye Monastral Blue (MB), which cannot be digested within the lysosomal compartment, was injected transsclerally into the subretinal space of Long Evans and Wistar rats. After 5 and 12 days respectively the eyes were enucleated and examined by light and electron microscopy. Cryo sections were made of eyes 5 days after MB injection for the application of immunohistochemical techniques using markers for epithelial cells (cytokeratin) and macrophages (ED 1). Retina, choroid and sclera were not altered in their morphology in the circumference of the MB-containing bubble generated by subretinal injection. After both 5 and 12 days no injected material was found extracellularly in the subretinal space. Especially high amounts of MB were found, in particular 5 days after injection, in lysosomes and melanosomes of RPE cells as well as in cells between choroidal melanocytes. Cells containing MB were seen in contact with choroidal and scleral blood vessels. These MB-containing cells in the choroid and in the sclera were positive for macrophage antibodies. Subretinal injection was confirmed as a suitable method for placing fluids into the subretinal space without affecting the morphology of the retina. Subretinal injected material was shown to be incorporated into lysosomes and melanosomes of RPE cells. The injected material was subsequently transported through Bruch's membrane to be finally removed from the eye via choroidal and scleral veins, the process involving macrophages.

  12. Electronic and optical properties of hydrogenated group-IV multilayer materials.

    Science.gov (United States)

    Pontes, Renato Borges; Mançano, Rosana Rabelo; da Silva, Rafael; Cótica, Luiz Fernando; Miwa, Roberto Hiroki; Padilha, José Eduardo

    2018-03-08

    Hydrogenated group-IV layered materials are semiconducting forms of silicene, germanene and stanene. We systematically studied the evolution of the structural, electronic and optical properties of these 2D materials as a function of the number of layers. We verify that the exfoliation energy increases upon the increase of the atomic number (Si → Sn) of the group-IV material. We show that silicane, independent of the number of layers, is an indirect band gap (Γ-M) material. This behavior is different from both germanane and stanane, which are direct band gap (Γ point) semiconductors. The calculated optical spectra show, for all systems, a red shift in the absorption edges and an enhanced absorption of the visible light for the in-plane (α ‖ ) component upon the increase in the number of layers and, also as a function of the increasing atomic number. Our findings also indicate that: (i) (XH 2 ) m (YH 2 ) n vdW heterostructures will always present a type-I band alignment for X = Si and Y = Ge or Sn, whereas (ii) for X = Ge and Y = Sn, the band alignment can be tuned (type-I ↔ type-II) by the number of layers (m,n).

  13. Effects of an applied voltage on direct interspecies electron transfer via conductive materials for methane production.

    Science.gov (United States)

    Lee, Jung-Yeol; Park, Jeong-Hoon; Park, Hee-Deung

    2017-10-01

    Direct interspecies electron transfer (DIET) between exoelectrogenic bacteria and methanogenic archaea via conductive materials is reported as an efficient method to produce methane in anaerobic organic waste digestion. A voltage can be applied to the conductive materials to accelerate the DIET between two groups of microorganisms to produce methane. To evaluate this hypothesis, two sets of anaerobic serum bottles with and without applied voltage were used with a pair of graphite rods as conductive materials to facilitate DIET. Initially, the methane production rate was similar between the two sets of serum bottles, and later the serum bottles with an applied voltage of 0.39V showed a 168% higher methane production rate than serum bottles without an applied voltage. In cyclic voltammograms, the characteristic redox peaks for hydrogen and acetate oxidation were identified in the serum bottles with an applied voltage. In the microbial community analyses, hydrogenotrophic methanogens (e.g. Methanobacterium) were observed to be abundant in serum bottles with an applied voltage, while methanogens utilizing carbon dioxide (e.g., Methanosaeta and Methanosarcina) were dominant in serum bottles without an applied voltage. Taken together, the applied voltage on conductive materials might not be effective to promote DIET in methane production. Instead, it appeared to generate a condition for hydrogenotrophic methanogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Improved Understanding of Space Radiation Effects on Exploration Electronics by Advanced Modeling of Nanoscale Devices and Novel Materials, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA space exploration missions will use nanometer-scale electronic technologies which call for a shift in how radiation effects in such devices and materials...

  15. Radiation processing of polymers with high energy electron beams: novel materials and processes

    International Nuclear Information System (INIS)

    Sarma, K.S.S.; Sabharwal, Sunil

    2002-01-01

    High-energy ionizing radiation available from electron beam (EB) accelerators has the ability to create extremely reactive species like free radicals or ions at room temperature or even at low temperature in any phase and in a variety of substrates without addition of external additives. This unique advantage of high energy has been utilized in the recent years to produce better quality materials in an environment friendly and cost-effective manner. The availability of high power and reliable EB accelerators has provided new tools to modify the materials and/or processes for a variety of applications. At BARC, a 2 MeV, 20 kW electron beam accelerator has been the nucleus of developing industrial applications of radiation processing in India for last 10 years. The focus has been on developing technologies that are of relevance to Indian socio-economic conditions and also provide economic benefits to the industry. In the areas of polymer processing industry, commercial success has already been achieved while for exploring its applications in the areas of food and agriculture and environment, technology demonstration plants are being set up. The current status of the programme, the new developments and future direction of radiation processing technology shall be presented in this paper. (author)

  16. Self-assembled peptide nanotubes as electronic materials: An evaluation from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Akdim, Brahim, E-mail: brahim.akdim.ctr@us.af.mil, E-mail: ruth.pachter@us.af.mil [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., 500 Springfield Pike, Dayton, Ohio 454331 (United States); Pachter, Ruth, E-mail: brahim.akdim.ctr@us.af.mil, E-mail: ruth.pachter@us.af.mil; Naik, Rajesh R. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States)

    2015-05-04

    In this letter, we report on the evaluation of diphenylalanine (FF), dityrosine (YY), and phenylalanine-tryptophan (FW) self-assembled peptide nanotube structures for electronics and photonics applications. Realistic bulk peptide nanotube material models were used in density functional theory calculations to mimic the well-ordered tubular nanostructures. Importantly, validated functionals were applied, specifically by using a London dispersion correction to model intertube interactions and a range-separated hybrid functional for accurate bandgap calculations. Bandgaps were found consistent with available experimental data for FF, and also corroborate the higher conductance reported for FW in comparison to FF peptide nanotubes. Interestingly, the predicted bandgap for the YY tubular nanostructure was found to be slightly higher than that of FW, suggesting higher conductance as well. In addition, the band structure calculations along the high symmetry line of nanotube axis revealed a direct bandgap for FF. The results enhance our understanding of the electronic properties of these material systems and will pave the way into their application in devices.

  17. Constructal design of phase change material enclosures used for cooling electronic devices

    International Nuclear Information System (INIS)

    Kalbasi, Rasool; Salimpour, Mohammad Reza

    2015-01-01

    Recent developments in cooling methods for portable electronic devices have heightened the need for using the large latent heat capacity of phase change materials (PCM). The aim of the present study is to evaluate the thermal characteristics of a PCM-based heat sink with high conductive materials. The solution is acquired as a procession of optimization stages which starts with the elemental area and proceeds toward the first assembly. Every optimization stage is the result of maximizing the safe operation time without allowing the electronics to reach the critical temperature. Primarily, the degrees of freedom and constrains were defined and then by changing the geometrical parameters, the target function which is the maximization of operation time, was optimized. Results show that the melting process in rectangular enclosures with vertical fins attached to the heated bottom surface can be affected by the contact surface between the fin and PCM and the convection of the melted PCM. For a rectangular enclosure with a constant area, it is better to use wider enclosure than the square and thin one. Also results indicate that the ratio of the vertical fin thickness to the horizontal one does not have a considerable effect on performance. By increasing the number of enclosures, the contact surface is raised, but the performance is not necessarily improved. - Highlights: • Thermal characteristics of a finned PCM-based heat sink are studied. • Constructal theory was used to optimize the PCM enclosures. • By increasing the number of enclosures, the performance is not necessarily improved

  18. Study of the material photon and electron background and the liquid argon detector veto efficiency of the CDEX-10 experiment

    Science.gov (United States)

    Su, Jian; Zeng, Zhi; Ma, Hao; Yue, Qian; Cheng, Jian-Ping; Chang, Jian-Ping; Chen, Nan; Chen, Ning; Chen, Qing-Hao; Chen, Yun-Hua; Chuang, Yo-Chun; Deng, Zhi; Du, Qiang; Gong, Hui; Hao, Xi-Qing; He, Qing-Ju; Huang, Han-Xiong; Huang, Teng-Rui; Jiang, Hao; Kang, Ke-Jun; Li, Hau-Bin; Li, Jian-Min; Li, Jin; Li, Jun; Li, Xia; Li, Xin-Ying; Li, Xue-Qian; Li, Yu-Lan; Li, Yuan-Jing; Liao, Heng-Yi; Lin, Fong-Kay; Lin, Shin-Ted; Liu, Shu-Kui; Lü, Lan-Chun; Mao, Shao-Ji; Qin, Jian-Qiang; Ren, Jie; Ren, Jing; Ruan, Xi-Chao; Shen, Man-Bin; Lakhwinder, Singh; Manoj, Kumar Singh; Arun, Kumar Soma; Tang, Chang-Jian; Tseng, Chao-Hsiung; Wang, Ji-Min; Wang, Li; Wang, Qing; Wong Tsz-King, Henry; Wu, Shi-Yong; Wu, Yu-Cheng; Xing, Hao-Yang; Xu, Yin; Xue, Tao; Yang, Li-Tao; Yang, Song-Wei; Yi, Nan; Yu, Chun-Xu; Yu, Hao; Yu, Xun-Zhen; Zeng, Xiong-Hui; Zhang, Lan; Zhang, Yun-Hua; Zhao, Ming-Gang; Zhao, Wei; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Wei-Bin; Zhu, Xue-Zhou; Zhu, Zhong-Hua; CDEX Collaboration

    2015-03-01

    The China Dark Matter Experiment (CDEX) is located at the China Jinping Underground Laboratory (CJPL) and aims to directly detect the weakly interacting massive particles (WIMP) flux with high sensitivity in the low mass region. Here we present a study of the predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within the GEANT4 program. Then the photon and electron background level in the energy region of interest (<10-2events·kg1·day-1·keV-1 (cpkkd)) is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of the CDEX-10 experiment, 0.1cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible. Supported by National Natural Science Foundation of China (11175099, 10935005, 10945002, 11275107, 11105076) and State Key Development Program of Basic Research of China (2010CB833006)

  19. Study of the material photon and electron background and the liquid argon detector veto efficiency of the CDEX-10 experiment

    International Nuclear Information System (INIS)

    Su Jian; Zeng Zhi; Ma Hao

    2015-01-01

    The China Dark Matter Experiment (CDEX) is located at the China Jinping Underground Laboratory (CJPL) and aims to directly detect the weakly interacting massive particles (WIMP) flux with high sensitivity in the low mass region. Here we present a study of the predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within the GEANT4 program. Then the photon and electron background level in the energy region of interest (< 10 -2 events·kg 1 ·day -1 ·keV -1 (cpkkd)) is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of the CDEX-10 experiment, 0.1cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible. (authors)

  20. Structural analysis, electronic properties, and band gaps of a graphene nanoribbon: A new 2D materials

    Science.gov (United States)

    Dass, Devi

    2018-03-01

    Graphene nanoribbon (GNR), a new 2D carbon nanomaterial, has some unique features and special properties that offer a great potential for interconnect, nanoelectronic devices, optoelectronics, and nanophotonics. This paper reports the structural analysis, electronic properties, and band gaps of a GNR considering different chirality combinations obtained using the pz orbital tight binding model. In structural analysis, the analytical expressions for GNRs have been developed and verified using the simulation for the first time. It has been found that the total number of unit cells and carbon atoms within an overall unit cell and molecular structure of a GNR have been changed with the change in their chirality values which are similar to the values calculated using the developed analytical expressions thus validating both the simulation as well as analytical results. Further, the electronic band structures at different chirality values have been shown for the identification of metallic and semiconductor properties of a GNR. It has been concluded that all zigzag edge GNRs are metallic with very small band gaps range whereas all armchair GNRs show both the metallic and semiconductor nature with very small and high band gaps range. Again, the total number of subbands in each electronic band structure is equal to the total number of carbon atoms present in overall unit cell of the corresponding GNR. The semiconductors GNRs can be used as a channel material in field effect transistor suitable for advanced CMOS technology whereas the metallic GNRs could be used for interconnect.

  1. Electronic structure and high thermoelectric properties of a new material Ba3Cu20Te13

    International Nuclear Information System (INIS)

    Yang, Gui; Wu, Jinghe; Zhang, Jing; Ma, Dongwei

    2016-01-01

    The electronic structure and high thermoelectric properties of Ba 3 Cu 20 Te 13 are studied using first principles calculations and the semiclassical Boltzmann theory. The coexistence of ionic and covalent bonding in Ba 3 Cu 20 Te 13 indicates that it is a Zintl phase compound. The calculated band structure shows that the compound is a semiconductor with an indirect band gap ∼0.45 eV, which is an appropriate band for the high thermoelectric performance. The transport calculations based on the electronic structure indicate that it exhibits relatively large Seebeck coefficients, high electrical conductivities, and high power factor. For Ba 3 Cu 20 Te 13 , the n-type doping may achieve a higher thermoelectric performance than that of p-type doping. It is worth noting that the thermoelectric parameters of Ba 3 Cu 20 Te 13 are comparable or larger than that of Ca 5 Al 2 Sb 6 , a typical Zintl compound representative with high thermoelectric performance. - Highlights: • The electronic structure and thermoelectric(TE) properties are firstly studied. • The heavy and light bands near the Fermi level benefit TE properties. • The comparison indicates Ba 3 Cu 20 Te 13 is a potential high TE material.

  2. Mechanically Compliant Electronic Materials for Wearable Photovoltaics and Human-Machine Interfaces

    Science.gov (United States)

    O'Connor, Timothy Francis, III

    Applications of stretchable electronic materials for human-machine interfaces are described herein. Intrinsically stretchable organic conjugated polymers and stretchable electronic composites were used to develop stretchable organic photovoltaics (OPVs), mechanically robust wearable OPVs, and human-machine interfaces for gesture recognition, American Sign Language Translation, haptic control of robots, and touch emulation for virtual reality, augmented reality, and the transmission of touch. The stretchable and wearable OPVs comprise active layers of poly-3-alkylthiophene:phenyl-C61-butyric acid methyl ester (P3AT:PCBM) and transparent conductive electrodes of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and devices could only be fabricated through a deep understanding of the connection between molecular structure and the co-engineering of electronic performance with mechanical resilience. The talk concludes with the use of composite piezoresistive sensors two smart glove prototypes. The first integrates stretchable strain sensors comprising a carbon-elastomer composite, a wearable microcontroller, low energy Bluetooth, and a 6-axis accelerometer/gyroscope to construct a fully functional gesture recognition glove capable of wirelessly translating American Sign Language to text on a cell phone screen. The second creates a system for the haptic control of a 3D printed robot arm, as well as the transmission of touch and temperature information.

  3. Electron Tomography: A Three-Dimensional Analytic Tool for Hard and Soft Materials Research.

    Science.gov (United States)

    Ercius, Peter; Alaidi, Osama; Rames, Matthew J; Ren, Gang

    2015-10-14

    Three-dimensional (3D) structural analysis is essential to understand the relationship between the structure and function of an object. Many analytical techniques, such as X-ray diffraction, neutron spectroscopy, and electron microscopy imaging, are used to provide structural information. Transmission electron microscopy (TEM), one of the most popular analytic tools, has been widely used for structural analysis in both physical and biological sciences for many decades, in which 3D objects are projected into two-dimensional (2D) images. In many cases, 2D-projection images are insufficient to understand the relationship between the 3D structure and the function of nanoscale objects. Electron tomography (ET) is a technique that retrieves 3D structural information from a tilt series of 2D projections, and is gradually becoming a mature technology with sub-nanometer resolution. Distinct methods to overcome sample-based limitations have been separately developed in both physical and biological science, although they share some basic concepts of ET. This review discusses the common basis for 3D characterization, and specifies difficulties and solutions regarding both hard and soft materials research. It is hoped that novel solutions based on current state-of-the-art techniques for advanced applications in hybrid matter systems can be motivated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Radiation effects in nuclear materials: Role of nuclear and electronic energy losses and their synergy

    Energy Technology Data Exchange (ETDEWEB)

    Thomé, Lionel [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS-IN2P3-Université Paris-Sud; Debelle, Aurelien [Universite Paris Sud, Orsay, France; Garrido, Frederico [Universite Paris Sud, Orsay, France; Mylonas, Stamatis [Universite Paris Sud, Orsay, France; Décamps, B. [Universite Paris Sud, Orsay, France; Bachelet, C. [Universite Paris Sud, Orsay, France; Sattonnay, G. [LEMHE/ICMMO, Université Paris-Sud, Bât. Orsay, France; Moll, Sandra [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Pellegrino, S. [French Atomic Energy Commission (CEA); Miro, S. [French Atomic Energy Commission (CEA); Trocellier, P. [French Atomic Energy Commission (CEA); Serruys, Y. [French Atomic Energy Commission (CEA); Velisa, G. [French Atomic Energy Commission (CEA); Grygiel, C. [CNRS, France; Monnet, I. [CIMAP, CEA-CNRS-Université de Caen, France; Toulemonde, Marcel [French Atomic Energy Commission (CEA), French National Centre for Scientific Research (CNRS)-ENSICAE; Simon, P. [CEMHTI, CNRS, France; Jagielski, Jacek [Institute for Electronic Materials Technology; Jozwik-Biala, Iwona [Institute for Electronic Materials Technology; Nowicki, Lech [Soltan Institute for Nuclear Studies, Swierk, Poland; Behar, M. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre,; Weber, William J [ORNL; Zhang, Yanwen [ORNL; Backman, Marie [University of Tennessee, Knoxville (UTK); Nordlund, Kai [University of Helsinki; Djurabekova, Flyura [University of Helsinki

    2013-01-01

    Ceramic oxides and carbides are promising matrices for the immobilization and/or transmutation of nuclear wastes, cladding materials for gas-cooled fission reactors and structural components for fusion reactors. For these applications there is a need of fundamental data concerning the behavior of nuclear ceramics upon irradiation. This article is focused on the presentation of a few remarkable examples regarding ion-beam modifications of nuclear ceramics with an emphasis on the mechanisms leading to damage creation and phase transformations. Results obtained by combining advanced techniques (Rutherford backscattering spectrometry and channeling, X-ray diffraction, transmission electron microscopy, Raman spectroscopy) concern irradiations in a broad energy range (from keV to GeV) with the aim of exploring both nuclear collision (Sn) and electronic excitation (Se) regimes. Finally, the daunting challenge of the demonstration of the existence of synergistic effects between Sn and Se is tackled by discussing the healing due to intense electronic energy deposition (SHIBIEC) and by reporting results recently obtained in dual-beam irradiation (DBI) experiments.

  5. Phosphorene Oxide: Stability and electronic properties of a novel 2D material

    OpenAIRE

    Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

    2014-01-01

    Phosphorene, the monolayer form of the (black) phosphorus, was recently exfoliated from its bulk counterpart. Phosphorene oxide, by analogy to graphene oxide, is expected to have novel chemical and electronic properties, and may provide an alternative route to synthesis of phosphorene. In this letter, we investigate physical and chemical properties of the phosphorene oxide including its formation by the oxygen adsorption on the bare phosphorene. Analysis of the phonon dispersion curves finds ...

  6. Characterization of a quadrant diamond transmission X-ray detector including a precise determination of the mean electron-hole pair creation energy.

    Science.gov (United States)

    Keister, Jeffrey W; Cibik, Levent; Schreiber, Swenja; Krumrey, Michael

    2018-03-01

    Precise monitoring of the incoming photon flux is crucial for many experiments using synchrotron radiation. For photon energies above a few keV, thin semiconductor photodiodes can be operated in transmission for this purpose. Diamond is a particularly attractive material as a result of its low absorption. The responsivity of a state-of-the art diamond quadrant transmission detector has been determined, with relative uncertainties below 1% by direct calibration against an electrical substitution radiometer. From these data and the measured transmittance, the thickness of the involved layers as well as the mean electron-hole pair creation energy were determined, the latter with an unprecedented relative uncertainty of 1%. The linearity and X-ray scattering properties of the device are also described.

  7. Transformational Electronics: Towards Flexible Low-Cost High Mobility Channel Materials

    KAUST Repository

    Nassar, Joanna M.

    2014-05-01

    For the last four decades, Si CMOS technology has been advancing with Moore’s law prediction, working itself down to the sub-20 nm regime. However, fundamental problems and limitations arise with the down-scaling of transistors and thus new innovations needed to be discovered in order to further improve device performance without compromising power consumption and size. Thus, a lot of studies have focused on the development of new CMOS compatible architectures as well as the discovery of new high mobility channel materials that will allow further miniaturization of CMOS transistors and improvement of device performance. Pushing the limits even further, flexible and foldable electronics seem to be the new attractive topic. By being able to make our devices flexible through a CMOS compatible process, one will be able to integrate hundreds of billions of more transistors in a small volumetric space, allowing to increase the performance and speed of our electronics all together with making things thinner, lighter, smaller and even interactive with the human skin. Thus, in this thesis, we introduce for the first time a cost-effective CMOS compatible approach to make high-k/metal gate devices on flexible Germanium (Ge) and Silicon-Germanium (SiGe) platforms. In the first part, we will look at the various approaches in the literature that has been developed to get flexible platforms, as well as we will give a brief overview about epitaxial growth of Si1-xGex films. We will also examine the electrical properties of the Si1-xGex alloys up to Ge (x=1) and discuss how strain affects the band structure diagram, and thus the mobility of the material. We will also review the material growth properties as well as the state-of-the-art results on high mobility metal-oxide semiconductor capacitors (MOSCAPs) using strained SiGe films. Then, we will introduce the flexible process that we have developed, based on a cost-effective “trench-protect-release-reuse” approach, utilizing

  8. Preparation and thermal conductivity enhancement of composite phase change materials for electronic thermal management

    International Nuclear Information System (INIS)

    Wu, Weixiong; Zhang, Guoqing; Ke, Xiufang; Yang, Xiaoqing; Wang, Ziyuan; Liu, Chenzhen

    2015-01-01

    Highlights: • A kind of composite phase change material board (PCMB) is prepared and tested. • PCMB presents a large thermal storage capacity and enhanced thermal conductivity. • PCMB displays much better cooling effect in comparison to natural air cooling. • PCMB presents different cooling characteristics in comparison to ribbed radiator. - Abstract: A kind of phase change material board (PCMB) was prepared for use in the thermal management of electronics, with paraffin and expanded graphite as the phase change material and matrix, respectively. The as-prepared PCMB presented a large thermal storage capacity of 141.74 J/g and enhanced thermal conductivity of 7.654 W/(m K). As a result, PCMB displayed much better cooling effect in comparison to natural air cooling, i.e., much lower heating rate and better uniformity of temperature distribution. On the other hand, compared with ribbed radiator technology, PCMB also presented different cooling characteristics, demonstrating that they were suitable for different practical application

  9. Applications of free-electron lasers to measurements of energy transfer in biopolymers and materials

    Science.gov (United States)

    Edwards, Glenn S.; Johnson, J. B.; Kozub, John A.; Tribble, Jerri A.; Wagner, Katrina

    1992-08-01

    Free-electron lasers (FELs) provide tunable, pulsed radiation in the infrared. Using the FEL as a pump beam, we are investigating the mechanisms for energy transfer between localized vibrational modes and between vibrational modes and lattice or phonon modes. Either a laser-Raman system or a Fourier transform infrared (FTIR) spectrometer will serve as the probe beam, with the attribute of placing the burden of detection on two conventional spectroscopic techniques that circumvent the limited response of infrared detectors. More specifically, the Raman effect inelastically shifts an exciting laser line, typically a visible frequency, by the energy of the vibrational mode; however, the shifted Raman lines also lie in the visible, allowing for detection with highly efficient visible detectors. With regards to FTIR spectroscopy, the multiplex advantage yields a distinct benefit for infrared detector response. Our group is investigating intramolecular and intermolecular energy transfer processes in both biopolymers and more traditional materials. For example, alkali halides contain a number of defect types that effectively transfer energy in an intermolecular process. Similarly, the functioning of biopolymers depends on efficient intramolecular energy transfer. Understanding these mechanisms will enhance our ability to modify biopolymers and materials with applications to biology, medecine, and materials science.

  10. Updating and expanding the library of materials on NASA Spacelink electronic information system

    Science.gov (United States)

    Blake, Jean A.

    1992-01-01

    NASA Spacelink, a proven resource medium, may be accessed over telephone lines or via the Internet by teachers or anyone with a computer or modem. It is a collection of historical and current information on NASA programs and activities. Included in this library is information on a variety of NASA programs, updates on Shuttle status, news releases, aeronautics, space exploration, classroom materials, NASA Educational Services, and computer programs and graphics. The material stored in Spacelink has found widespread use by teachers and others, and is being used to stimulate students, particularly in the area of aerospace science.

  11. Electron irradiation of the material samples of new generation nuclear reactors in the supercritical water convection loop

    International Nuclear Information System (INIS)

    Bakai, A.S.; Boriskin, V.N.; Bratchenko, M.I.; Biller, E.Z.; Bytenko, P.A.; Bocharov, V.A.; Vereshchaka, V.N.; Dovbnya, A.N.; Duldya, S.V.; Gorenko, Yu.V.; Koval'ev, G.G.; Momot, V.A.; Repihov, O.A.; Romanovsky, S.K.; Savchenko, A.N.; Selezn'ev, V.V.; Solodovnikov, V.I.; Titov, V.I.; Torgovkin, A.V.; Handak, V.V.; Shelepko, S.V.; Tcebenko, G.N.

    2013-01-01

    The design of the Supercritical Water Convection Loop with an irradiation chamber is described [1]. The plant makes possible to carry out simulation corrosion tests of potential structural materials for Generation IV reactors with the Supercritical Water-Cooling under irradiation. Specimens in water flow were irradiated in situ by the 10 MeV/10 kW electron beam of the LAE-10 linear accelerator. The high power relativistic electron-gamma irradiation delivers the absorbed doses sufficient for activation of corrosion and oxidation of material-coolant interfaces. The first results of the electron irradiation of Zr and Inconel 690 samples during 500 hours are gave

  12. Effect of magnetic field, pressure and correlated hopping of electrons on conductivity of Mott-Hubbard material

    International Nuclear Information System (INIS)

    Didukh, Leonid; Skorenkyy, Yuriy; Kramar, Oleksandr; Dovhopyaty, Yuriy

    2006-01-01

    We discuss the influence of external magnetic field h and pressure p on a static conductivity of Mott-Hubbard material which is described by model with strong intra-site Coulomb repulsion and correlated hopping of electrons. Green function and energy spectrum are calculated by the use of a variant of projection procedure. The static conductivity σ xx is calculated as a function of electron concentration n, h, p, and temperature T. The correlated hopping is shown to cause the electron-hole asymmetry of transport properties of real materials

  13. Do Authors of Online Electronic Materials for Teaching Mathematics Use Their Potential to Use Non-Stereotypical Cultural Settings?

    Science.gov (United States)

    Moraová, Hana

    2017-01-01

    The paper focuses on the cultural content of online electronic materials developed primarily by Czech in-service teachers of mathematics for smartboards. The author presents an analysis of these materials with a focus on the cultural settings of word problems they contain. The paper builds on a poster presented on ECEL 2015 conference and a paper…

  14. Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing

    Science.gov (United States)

    Held, Christian; Liewald, Mathias; Schleich, Ralf; Sindel, Manfred

    2010-06-01

    The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.

  15. Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing

    International Nuclear Information System (INIS)

    Held, Christian; Liewald, Mathias; Schleich, Ralf; Sindel, Manfred

    2010-01-01

    The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.

  16. Standard practice for determining average grain size using electron backscatter diffraction (EBSD) in fully recrystallized polycrystalline materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice is used to determine grain size from measurements of grain areas from automated electron backscatter diffraction (EBSD) scans of polycrystalline materials. 1.2 The intent of this practice is to standardize operation of an automated EBSD instrument to measure ASTM G directly from crystal orientation. The guidelines and caveats of E112 apply here, but the focus of this standard is on EBSD practice. 1.3 This practice is only applicable to fully recrystallized materials. 1.4 This practice is applicable to any crystalline material which produces EBSD patterns of sufficient quality that a high percentage of the patterns can be reliably indexed using automated indexing software. 1.5 The practice is applicable to any type of grain structure or grain size distribution. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 The values stated in inch-pound units are to be regarded as standard. The values given in parenthe...

  17. Novel Aspects of Materials Processing by Ultrafast Lasers: From Electronic to Biological and Cultural Heritage Applications

    International Nuclear Information System (INIS)

    Fotakis, C; Zorba, V; Stratakis, E; Athanassiou, A; Tzanetakis, P; Zergioti, I; Papagoglou, D G; Sambani, K; Filippidis, G; Farsari, M; Pouli, V; Bounos, G; Georgiou, S

    2007-01-01

    Materials processing by ultrafast lasers offers several distinct possibilities for micro/nano scale applications. This is due to the unique characteristics of the laser-matter interactions involved, when sub-picosecond pulses are employed. Prospects arising will be discussed in the context of surface and in bulk laser induced modifications. In particular, examples of diverse applications including the development and functionalization of laser engineered surfaces, the laser transfer of biomolecules and the functionalization of 3D structures constructed by three-photon stereolithography will be presented. Furthermore, the removal of molecular substrates by ultrafast laser ablation will be discussed with emphasis placed on assessing the photochemical changes induced in the remaining bulk material. The results indicate that in femtosecond laser processing of organic materials, besides the well acknowledged morphological advantages, a second fundamental factor responsible for its success pertains to the selective chemical effects. This is crucial for the laser cleaning of sensitive painted artworks

  18. Preparation and certification of the Polish reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis

    International Nuclear Information System (INIS)

    Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

    1997-01-01

    A new Polish certified reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis has been prepared. Certification of the candidate reference material was based on the world-wide interlaboratory comparison in which 60 laboratories from 18 countries, participated using various analytical methods and techniques. Data evaluation performed by means of the new multifunctional software package -SSQC. Recommended values were assigned for 33 and 'information' values for 10 elements, respectively. The validity of 'certified' values was confirmed for several elements using 'very accurate' methods developed in this Laboratory. (author)

  19. Preparation and certification of the Polish reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

    1997-12-31

    A new Polish certified reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis has been prepared. Certification of the candidate reference material was based on the world-wide interlaboratory comparison in which 60 laboratories from 18 countries, participated using various analytical methods and techniques. Data evaluation performed by means of the new multifunctional software package -SSQC. Recommended values were assigned for 33 and `information` values for 10 elements, respectively. The validity of `certified` values was confirmed for several elements using `very accurate` methods developed in this Laboratory. (author). 47 refs, 28 figs, 12 tabs.

  20. Night time cooling by ventilation or night sky radiation combined with in-room radiant cooling panels including phase change materials

    DEFF Research Database (Denmark)

    Bourdakis, Eleftherios; Olesen, Bjarne W.; Grossule, Fabio

    constructed at the Technical University of Denmark, where the outside PVT panels are connected through a storage tank to in-room radiant ceiling panels. The radiant ceiling panels include phase change material (PCM) and embedded pipes for circulating water. Due to the phase change material it is possible...... depending on the sky clearness. This cooling power was enough to remove the stored heat and regenerate the ceiling panels. The validation simulation model results related to PCM were close to the corresponding results extracted from the experiment, while the results related to the production of cold water...

  1. Bis-aryl substituted dioxaborines as electron-transport materials: a comparative density functional theory investigation with oxadiazoles and siloles

    International Nuclear Information System (INIS)

    Risko, C.; Zojer, E.; Brocorens, P.; Marder, S.R.; Bredas, J.L.

    2005-01-01

    We report on a detailed quantum-chemical comparison of the electronic structures, vertical electron affinities, and intramolecular reorganization energies for bis-aryl substituted dioxaborine, oxadiazole, and silole derivatives. The results indicate that the HOMO and LUMO energies of the substituted compounds can be tuned on the order of 2-3 eV via minor changes in the substitution patterns, with the HOMO and LUMO levels for the dioxaborine derivatives consistently the most energy stabilized. Additionally, large vertical electron affinities and comparable intramolecular reorganization energies confirm that dioxaborine systems are interesting candidates for electron transport materials

  2. Material interface detection based on secondary electron images for focused ion beam machining.

    Science.gov (United States)

    Joe, Hang-Eun; Lee, Won-Sup; Jun, Martin B G; Park, No-Cheol; Min, Byung-Kwon

    2018-01-01

    A method for interface detection is proposed for focused ion beam (FIB) processes of multilayered targets. As multilayers have emerged as promising structures for nanodevices, the FIB machining of multilayers has become a challenging issue. We proposed material interface detection by monitoring secondary electron (SE) images captured during the FIB process. The average of the gray-levels and the skewness coefficient of gray-level histograms of the SE images were evaluated to recognize endpoints for the FIB processes. The FIB process control with the proposed method was demonstrated by fabricating the nanostructures on the multilayered target without thickness information. It was also demonstrated on a curved surface. Grooves with a desired depth into the target and an aperture as an opening window were precisely fabricated by the FIB process control. The proposed strategy of the FIB process can be used for complex substrates such as curved or flexible targets. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Tunable electronic and magnetic properties of two‐dimensional materials and their one‐dimensional derivatives

    Science.gov (United States)

    Zhang, Zhuhua; Liu, Xiaofei; Yu, Jin; Hang, Yang; Li, Yao; Guo, Yufeng; Xu, Ying; Sun, Xu; Zhou, Jianxin

    2016-01-01

    Low‐dimensional materials exhibit many exceptional properties and functionalities which can be efficiently tuned by externally applied force or fields. Here we review the current status of research on tuning the electronic and magnetic properties of low‐dimensional carbon, boron nitride, metal‐dichalcogenides, phosphorene nanomaterials by applied engineering strain, external electric field and interaction with substrates, etc, with particular focus on the progress of computational methods and studies. We highlight the similarities and differences of the property modulation among one‐ and two‐dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities in typical nanostructures are also presented. Finally, prospective and challenges for applying the tunable properties into functional devices are discussed. WIREs Comput Mol Sci 2016, 6:324–350. doi: 10.1002/wcms.1251 For further resources related to this article, please visit the WIREs website. Conflict of interest: The authors have declared no conflicts of interest for this article. PMID:27818710

  4. Recent Progress in First-Principles Methods for Computing the Electronic Structure of Correlated Materials

    Directory of Open Access Journals (Sweden)

    Fredrik Nilsson

    2018-03-01

    Full Text Available Substantial progress has been achieved in the last couple of decades in computing the electronic structure of correlated materials from first principles. This progress has been driven by parallel development in theory and numerical algorithms. Theoretical development in combining ab initio approaches and many-body methods is particularly promising. A crucial role is also played by a systematic method for deriving a low-energy model, which bridges the gap between real and model systems. In this article, an overview is given tracing the development from the LDA+U to the latest progress in combining the G W method and (extended dynamical mean-field theory ( G W +EDMFT. The emphasis is on conceptual and theoretical aspects rather than technical ones.

  5. The erosion and erosion products of tungsten and carbon based materials bombarded by high energy pulse electron beam

    International Nuclear Information System (INIS)

    Liu Xiang; Zhang Fu; Xu Zengyu; Liu Yong; Yoshida, N.; Noda, N.

    2002-01-01

    In this paper, the erosion behaviors and erosion products of tungsten and some carbon based materials, such as graphite, C/C composite and B 4 C/Cu functionally graded material, were investigated by using a pulse electron beam to simulate the vertical displacement events (VDE) process. The authors will focus on the forms and differences of erosion products among these testing materials, and make clear to their erosion mechanisms

  6. Impact of Mismatch Angle on Electronic Transport Across Grain Boundaries and Interfaces in 2D Materials.

    Science.gov (United States)

    Majee, Arnab K; Foss, Cameron J; Aksamija, Zlatan

    2017-11-29

    We study the impact of grain boundaries (GB) and misorientation angles between grains on electronic transport in 2-dimensional materials. Here we have developed a numerical model based on the first-principles electronic bandstructure calculations in conjunction with a method which computes electron transmission coefficients from simultaneous conservation of energy and momentum at the interface to essentially evaluate GB/interface resistance in a Landauer formalism. We find that the resistance across graphene GBs vary over a wide range depending on misorientation angles and type of GBs, starting from 53 Ω μm for low-mismatch angles in twin (symmetric) GBs to about 10 20  Ω μm for 21° mismatch in tilt (asymmetric) GBs. On the other hand, misorientation angles have weak influence on the resistance across MoS 2 GBs, ranging from about 130 Ω μm for low mismatch angles to about 6000 Ω μm for 21°. The interface resistance across graphene-MoS 2 heterojunctions also exhibits a strong dependence on misorientation angles with resistance values ranging from about 100 Ω μm for low-mismatch angles in Class-I (symmetric) interfaces to 10 15  Ω μm for 14° mismatch in Class-II (asymmetric) interfaces. Overall, symmetric homo/heterojunctions exhibit a weak dependence on misorientation angles, while in MoS 2 both symmetric and asymmetric GBs show a gradual dependence on mismatch angles.

  7. Electron beam irradiation to the allogeneic, xenogenic and synthetic bone materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soung Min; Park, Min Woo; Jeong, Hyun Oh [School of Dentistry Seoul National University, Seoul (Korea, Republic of); and others

    2013-07-01

    For the development of the biocompatible bony regeneration materials, allogenic, xenogenic and synthetic bone were irradiated by electron beam to change the basic components and structures. For the efficient electron beam irradiating condition of these allogenic, xenogenic and artificial bone substitutes, the optimal electron beam energy and their individual dose were established, to maximize the bony regeneration capacity. Commercial products of four allogenic bones, such as Accell (ISOTIS OrthogBiologics Co., USA), Allotis (Korea Bone Bank Co., Korea), Oragraft (LifeNet Co., USA), and Orthoblast (Integra Orthobiologics Inc., USA), six xenogenic bones, such as BBP (OscoTec Co., Korea), Bio-cera (OscoTec Co., Korea), Bio-oss (Geistlich Pharma AG, Switzerland), Indu-cera (OscoTec Co., Korea), OCS-B (Nibec Co., Korea), and OCS-H (Nibec Co., Korea), and six synthetic bones, such as BMP (Couellmedi Co., Korea), BoneMedik (Meta Biomed Co., Korea), Bone plus (Megagen Co., Korea), MBCP (Biomatlante Co., France), Osteon (Genoss Co., Korea), and Osteogen (Impladent LTD., USA), were used. We used 1.0 and 2.0 MeV superconduction accelerator, and/or microtrone with different individual 60, 120 kGy irradiation dose. Different dose irradiated specimens were divided 6 portions each, so total 360 groups were prepared. 4 portions were analyzed each by elementary analysis using FE-SEM (Field Emission Scanning Microscopy) and another 2 portions were grafted to the calvarial defect of Sprague-Dawley rat, following histologic, immunohistochemical analysis and TEM study were processed at the 8th and 16th weeks, in vivo. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MEST)

  8. Spin polarized auger electron spectroscopy (SPAES): An element specific local magnetization probe of magnetic materials

    Science.gov (United States)

    Anilturk, Onder S.

    Spin Polarized Auger Electron Spectroscopy (SPAES) is found to have application for investigating fundamental properties as well as element specific local magnetization information on magnetic materials. By using the uniqueness of the UTA-SEMPA tool, one can obtain the surface magnetic domain microstructure and also perform SPAES studies by probing a single domain at the surface. In the current study, knowing the probed domain, spin polarization of electrons from super Coster-Kronig MVV Auger emissions on 3%Si-Fe sheets have been investigated. It is observed that on both sides of 180° domains, separated by a domain wall with an out-of-plane component of magnetization, the spin polarized Auger spectra exhibit similar distributions with high polarization structures, which are consistent with the published data. The element specificity of the system is applied to Gd-Co composite system. Details of 4d core hole initiated Auger transitions showed that the 5d states have enhanced spin polarization, confirming the coupling of moments in the composite system via 5d states of Gd. It is also unambiguously observed that Co magnetic moments are indeed aligned antiparallel to the Gd ones via 4f-5d positive exchange and 3d-5d hybridization.

  9. Structures, Energetics, and Electronic Properties of Layered Materials and Nanotubes of Cadmium Chalcogenides

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jia [ORNL; Huang, Jingsong [ORNL; Sumpter, Bobby G [ORNL; Kent, Paul R [ORNL; Terrones Maldonado, Mauricio [ORNL; Smith, Sean C [ORNL

    2013-01-01

    The attractive optoelectronic properties of conducting polymers depend sensitively upon intra- and inter-polymer chain interactions, and therefore new methods to manipulate these interactions are continually being pursued. Here, we report a study of the isotopic effects of deuterium substitution on the structure, morphology, and optoelectronic properties of regioregular poly(3-hexylthiophene)s (P3HT) with an approach that combines the synthesis of deuterated materials, optoelectronic properties measurements, theoretical simulation, and neutron scattering. Selective substitutions of deuterium on the backbone or side-chains of P3HT result in distinct optoelectronic responses in P3HT/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) photovoltaics. Specifically, the weak non-covalent intermolecular interactions induced by the main-chain deuteration are shown to change the film crystallinity and morphology of P3HT/PCBM blends, and consequently reduce the short circuit current. However, decreased electronic coupling, the formation of a charge transfer state, and increased electron-phonon coupling resulting from side chain deuteration are shown to induce a remarkable reduction in open circuit voltage.

  10. Investigating fold structures of 2D materials by quantitative transmission electron microscopy.

    Science.gov (United States)

    Wang, Zhiwei; Zhang, Zengming; Liu, Wei; Wang, Zhong Lin

    2017-04-01

    We report an approach developed for deriving 3D structural information of 2D membrane folds based on the recently-established quantitative transmission electron microscopy (TEM) in combination with density functional theory (DFT) calculations. Systematic multislice simulations reveal that the membrane folding leads to sufficiently strong electron scattering which enables a precise determination of bending radius. The image contrast depends also on the folding angles of 2D materials due to the variation of projection potentials, which however exerts much smaller effect compared with the bending radii. DFT calculations show that folded edges are typically characteristic of (fractional) nanotubes with the same curvature retained after energy optimization. Owing to the exclusion of Stobbs factor issue, numerical simulations were directly used in comparison with the experimental measurements on an absolute contrast scale, which results in a successful determination of bending radius of folded monolayer MoS 2 films. The method should be applicable to characterizing all 2D membranes with 3D folding features. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Structural predictions for Correlated Electron Materials Using the Functional Dynamical Mean Field Theory Approach

    Science.gov (United States)

    Haule, Kristjan

    2018-04-01

    The Dynamical Mean Field Theory (DMFT) in combination with the band structure methods has been able to address reach physics of correlated materials, such as the fluctuating local moments, spin and orbital fluctuations, atomic multiplet physics and band formation on equal footing. Recently it is getting increasingly recognized that more predictive ab-initio theory of correlated systems needs to also address the feedback effect of the correlated electronic structure on the ionic positions, as the metal-insulator transition is almost always accompanied with considerable structural distortions. We will review recently developed extension of merger between the Density Functional Theory (DFT) and DMFT method, dubbed DFT+ embedded DMFT (DFT+eDMFT), whichsuccessfully addresses this challenge. It is based on the stationary Luttinger-Ward functional to minimize the numerical error, it subtracts the exact double-counting of DFT and DMFT, and implements self-consistent forces on all atoms in the unit cell. In a few examples, we will also show how the method elucidated the important feedback effect of correlations on crystal structure in rare earth nickelates to explain the mechanism of the metal-insulator transition. The method showed that such feedback effect is also essential to understand the dynamic stability of the high-temperature body-centered cubic phase of elemental iron, and in particular it predicted strong enhancement of the electron-phonon coupling over DFT values in FeSe, which was very recently verified by pioneering time-domain experiment.

  12. Design of nano-materials for high performance electronic and sensory applications

    Science.gov (United States)

    Ho, Johnny Chung Yin

    Device scaling has been one of the main driving forces for technology advancement in the semiconductor industry over last few decades. As this scaling continues into the future, serious fundamental and technological issues will arise as a result of the limitations of conventional device fabrication and materials, etc. Among these many challenges, in particular, there is a tremendous need for new processing technologies to control atomic composition in semiconductor structures as well as the application of new nanoscale high electronic mobility channel materials. In this dissertation, new nanoscale doping and nano-materials assembly approaches in electronic and sensor applications will be presented to tackle those challenges. Monolayer doping (MLD) is studied for the controllable, reliable and nanoscale doping of semiconductor materials by taking advantage of the crystalline nature and its self-limiting surface reaction properties. This method relies on the formation of a highly uniform and covalently bonded monolayer of dopant-containing molecules, which allows for deterministic positioning of dopant atoms on semiconductor surfaces. In a subsequent annealing step, the dopant atoms are diffused into the crystal lattice to attain the desired doping profile. Notably, the dopant areal dose can be tuned by utilization of the structural design of the molecular precursor. Combined with conventional spike annealing, the formation of sub-5 nm ultrashallow junctions (USJs) in Si has been achieved with ˜70% of the incorporated dopants being activated. In addition, this doping method is extended to compound semiconductors to enable 5 nm sulfur-doped junctions in indium arsenide, yielding n+/p USJs with the diodes exhibiting rectifying or negative differential resistance (NDR) behavior, depending on the background dopant concentration. Additionally, high-mobility nanomaterials such as indium arsenide nanowires have been characterized in detail, mainly on the intrinsic electron

  13. Sub-nanometre resolution of atomic motion during electronic excitation in phase-change materials.

    Science.gov (United States)

    Mitrofanov, Kirill V; Fons, Paul; Makino, Kotaro; Terashima, Ryo; Shimada, Toru; Kolobov, Alexander V; Tominaga, Junji; Bragaglia, Valeria; Giussani, Alessandro; Calarco, Raffaella; Riechert, Henning; Sato, Takahiro; Katayama, Tetsuo; Ogawa, Kanade; Togashi, Tadashi; Yabashi, Makina; Wall, Simon; Brewe, Dale; Hase, Muneaki

    2016-02-12

    Phase-change materials based on Ge-Sb-Te alloys are widely used in industrial applications such as nonvolatile memories, but reaction pathways for crystalline-to-amorphous phase-change on picosecond timescales remain unknown. Femtosecond laser excitation and an ultrashort x-ray probe is used to show the temporal separation of electronic and thermal effects in a long-lived (>100 ps) transient metastable state of Ge2Sb2Te5 with muted interatomic interaction induced by a weakening of resonant bonding. Due to a specific electronic state, the lattice undergoes a reversible nondestructive modification over a nanoscale region, remaining cold for 4 ps. An independent time-resolved x-ray absorption fine structure experiment confirms the existence of an intermediate state with disordered bonds. This newly unveiled effect allows the utilization of non-thermal ultra-fast pathways enabling artificial manipulation of the switching process, ultimately leading to a redefined speed limit, and improved energy efficiency and reliability of phase-change memory technologies.

  14. Real-Space Imaging of Carrier Dynamics of Materials Surfaces by Second-Generation Four-Dimensional Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya

    2015-09-14

    In the fields of photocatalysis and photovoltaics, ultrafast dynamical processes, including carrier trapping and recombination on material surfaces, are among the key factors that determine the overall energy conversion efficiency. A precise knowledge of these dynamical events on the nanometer (nm) and femtosecond (fs) scales was not accessible until recently. The only way to access such fundamental processes fully is to map the surface dynamics selectively in real space and time. In this study, we establish a second generation of four-dimensional scanning ultrafast electron microscopy (4D S-UEM) and demonstrate the ability to record time-resolved images (snapshots) of material surfaces with 650 fs and ∼5 nm temporal and spatial resolutions, respectively. In this method, the surface of a specimen is excited by a clocking optical pulse and imaged using a pulsed primary electron beam as a probe pulse, generating secondary electrons (SEs), which are emitted from the surface of the specimen in a manner that is sensitive to the local electron/hole density. This method provides direct and controllable information regarding surface dynamics. We clearly demonstrate how the surface morphology, grains, defects, and nanostructured features can significantly impact the overall dynamical processes on the surface of photoactive-materials. In addition, the ability to access two regimes of dynamical probing in a single experiment and the energy loss of SEs in semiconductor-nanoscale materials will also be discussed.

  15. Electron-beam nanosculpting and materials analysis of exfoliated bismuth selenide

    Science.gov (United States)

    Friedensen, Sarah; Parkin, William; Mlack, Jerome; Drndic, Marija

    We report on nanosculpting Bi2Se3 with a highly-focused electron beam in a scanning transmission electron microscope (STEM). Exfoliated Bi2Se3 flakes were transferred onto silicon nitride TEM windows and structures at least 100 nm by 100 nm in size were selected for shaping. Focused ion beam (FIB) cutting was used to carve larger features into the structures and provide preliminary thinning if desired. Then, a STEM probe was used to sculpt more delicate features, including nanowires of approximately 20 nm in width, point contacts, and T-shaped junctions. During STEM cutting, the structures were monitored using energy dispersive X-ray spectroscopy (EDS) mapping, electron diffraction, and high-resolution imaging, and it was found that the crystal structure remains largely intact. This process opens the way for in-situ determination of the effects of size and structure on electrical and thermal properties of Bi2Se3 and fabrication of nanodevices with more elaborate geometries than can be achieved with growth methods alone.

  16. Self-adapting denoising, alignment and reconstruction in electron tomography in materials science

    Energy Technology Data Exchange (ETDEWEB)

    Printemps, Tony, E-mail: tony.printemps@cea.fr [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Mula, Guido [Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria, S.P. 8km 0.700, 09042 Monserrato (Italy); Sette, Daniele; Bleuet, Pierre; Delaye, Vincent; Bernier, Nicolas; Grenier, Adeline; Audoit, Guillaume; Gambacorti, Narciso; Hervé, Lionel [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2016-01-15

    An automatic procedure for electron tomography is presented. This procedure is adapted for specimens that can be fashioned into a needle-shaped sample and has been evaluated on inorganic samples. It consists of self-adapting denoising, automatic and accurate alignment including detection and correction of tilt axis, and 3D reconstruction. We propose the exploitation of a large amount of information of an electron tomography acquisition to achieve robust and automatic mixed Poisson–Gaussian noise parameter estimation and denoising using undecimated wavelet transforms. The alignment is made by mixing three techniques, namely (i) cross-correlations between neighboring projections, (ii) common line algorithm to get a precise shift correction in the direction of the tilt axis and (iii) intermediate reconstructions to precisely determine the tilt axis and shift correction in the direction perpendicular to that axis. Mixing alignment techniques turns out to be very efficient and fast. Significant improvements are highlighted in both simulations and real data reconstructions of porous silicon in high angle annular dark field mode and agglomerated silver nanoparticles in incoherent bright field mode. 3D reconstructions obtained with minimal user-intervention present fewer artefacts and less noise, which permits easier and more reliable segmentation and quantitative analysis. After careful sample preparation and data acquisition, the denoising procedure, alignment and reconstruction can be achieved within an hour for a 3D volume of about a hundred million voxels, which is a step toward a more routine use of electron tomography. - Highlights: • Goal: perform a reliable and user-independent 3D electron tomography reconstruction. • Proposed method: self-adapting denoising and alignment prior to 3D reconstruction. • Noise estimation and denoising are performed using wavelet transform. • Tilt axis determination is done automatically as well as projection alignment.

  17. Effect of electron beam radio sterilization on cyclic olefin copolymers used as pharmaceutical storage materials

    Science.gov (United States)

    Barakat, Hala; Aymes-Chodur, Caroline; Saunier, Johanna; Yagoubi, Najet

    2013-03-01

    The aim of this work was to study the effect of radio-sterilization on cyclo olefin copolymers (COC), that can be used as pharmaceutical storage materials, both on the surface and in the volume of the material, and to investigate the impact of the presence of a lubricant. A cyclo olefin copolymer (TOPAS® 8007) was treated with an electron beam radio-sterilization at different doses ranging from 25 to 150 kGy. Polymer structure and bulk properties were evaluated by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Size Exclusion Chromatography (SEC). A good correlation between those analytical techniques was observed: oxidation products were formed and crosslinking of chains occured. Although these modifications were important, the effect on the thermal properties was weak. The analysis by Reversed Phase High Performance Liquid Chromatography (RP-HPLC) of extraction's solutions of COC after irradiation showed both a remarkable decrease of the extractable amount of polyphenolic antioxidant (Irganox 1010®) initially present in the matrix, and a generation of an important number of degradation products that represent potential migrants for pharmaceutical formulations. Surface modifications were evidenced by both (FTIR/ATR) and contact angle measurements of COC films. An increase in surface polarity of COC after radio-sterilization was observed.

  18. Electronic voting in dental materials education: the impact on students' attitudes and exam performance.

    Science.gov (United States)

    Barbour, Michele E

    2008-09-01

    Dental materials is an integral part of any undergraduate dental curriculum and is most commonly taught in a traditional didactic, lecture-based format. It suffers from the ignominy of being viewed by many as a dry, factual subject with little to excite or engage the student. In this article, the author presents the experimental use of an electronic voting (eVoting) system in an undergraduate dental materials course. The practical and aspirational aspects of its application are described. The objective was to assess the student perception of the experiment and the impact on end-of-course examination results. The eVoting system proved overwhelmingly popular with the students with 95 percent in favor of its use at the beginning of the course and 91 percent at the end. There was, however, no statistically significant impact on the results of the examination at the end of the course, when compared to the previous year's cohort of students for whom eVoting was not used. eVoting encouraged student interaction and engagement and contributed to student satisfaction but was not seen to affect the outcome measurement (end-of-course examination result).

  19. Evaluation of electronic states of implanted materials by molecular orbital calculation

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Kano, Shigeki

    1997-07-01

    In order to understand the effect of implanted atom in ceramics and metals on the sodium corrosion, the electronic structures of un-implanted and implanted materials were calculated using DV-Xα cluster method which was one of molecular orbital calculations. The calculated materials were β-Si 3 N 4 , α-SiC and β-SiC as ceramics, and f.c.c. Fe, b.c.c. Fe and b.c.c. Nb as metals. An Fe, Mo and Hf atom for ceramics, and N atom for metals were selected as implanted atoms. Consequently, it is expected that the corrosion resistance of β-Si 3 N 4 is improved, because the ionic bonding reduced by the implantation. When the implanted atom is occupied at interstitial site in α-SiC and β-SiC, the ionic bonding reduced. Hence, there is a possibility to improve the corrosion resistance of α-SiC and β-SiC. It is clear that Hf is most effective element among implanted atoms in this study. As the covalent bond between N atom and surrounding Fe atoms increased largely in f.c.c. Fe by N implantation, it was expected that the corrosion resistance of f.c.c. Fe improved in liquid sodium. (J.P.N.)

  20. A material flow analysis on current electrical and electronic waste disposal from Hong Kong households.

    Science.gov (United States)

    Lau, Winifred Ka-Yan; Chung, Shan-Shan; Zhang, Chan

    2013-03-01

    A material flow study on five types of household electrical and electronic equipment, namely television, washing machine, air conditioner, refrigerator and personal computer (TWARC) was conducted to assist the Government of Hong Kong to establish an e-waste take-back system. This study is the first systematic attempt on identifying key TWARC waste disposal outlets and trade practices of key parties involved in Hong Kong. Results from two questionnaire surveys, on local households and private e-waste traders, were used to establish the material flow of household TWARC waste. The study revealed that the majority of obsolete TWARC were sold by households to private e-waste collectors and that the current e-waste collection network is efficient and popular with local households. However, about 65,000 tonnes/yr or 80% of household generated TWARC waste are being exported overseas by private e-waste traders, with some believed to be imported into developing countries where crude recycling methods are practiced. Should Hong Kong establish a formal recycling network with tight regulatory control on imports and exports, the potential risks of current e-waste recycling practices on e-waste recycling workers, local residents and the environment can be greatly reduced. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Design of coupled cavity with energy modulated electron cyclotron resonance ion source for materials irradiation research

    Directory of Open Access Journals (Sweden)

    Z. Wang (王智

    2012-05-01

    Full Text Available The surface topography of samples after irradiation with heavy ions, protons, and helium ions based on accelerators is an important issue in the study of materials irradiation. We have coupled the separated function radio frequency quadrupole (SFRFQ electrodes and the traditional RFQ electrodes into a single cavity that can provide a 0.8 MeV helium beam for our materials irradiation project. The higher accelerating efficiency has been verified by the successful commissioning of the prototype SFRFQ cavity. An energy modulated electron cyclotron resonance (ECR ion source can achieve a well-bunched beam by loading a sine wave voltage onto the extracted electrodes. Bunching is achieved without the need for an external bunch cavity, which can substantially reduce the cost of the system and the length of the beam line. The coupled RFQ-SFRFQ with an energy modulated ECR ion source will lead to a more compact accelerator system. The conceptual design of this novel structure is presented in this paper.

  2. From Molecular Meccano to Nano-Functional Materials for Molecular Electronics Applications

    Science.gov (United States)

    Sue, Chi-Hau

    resulting MOF-1001 and MOF-1002, which adopt the primitive cubic structure, are capable of docking paraquat cation guests within the crown ethers inside in a stereoelectronically controlled fashion, a behavior similar to enzymes binding incoming substrates. And MOF-1030, which is synthesized from an exceptionally long [2]catenane organic strut, is a three-dimensional MOF structure with vast openness, allowing MIMs-based prototypical molecular switches to be anchored at precise locations and with uniform relative orientations throughout the framework as a whole. These studies not only represent efficient approaches to the preparation of MOFs with complex functionalities, but also set the stage for the development of next-generation nano-functional materials for molecular electronics applications.

  3. Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

    Directory of Open Access Journals (Sweden)

    Anastasios Stergiou

    2014-09-01

    Full Text Available Graphene research and in particular the topic of chemical functionalization of graphene has exploded in the last decade. The main aim is to increase the solubility and thereby enhance the processability of the material, which is otherwise insoluble and inapplicable for technological applications when stacked in the form of graphite. To this end, initially, graphite was oxidized under harsh conditions to yield exfoliated graphene oxide sheets that are soluble in aqueous media and amenable to chemical modifications due to the presence of carboxylic acid groups at the edges of the lattice. However, it was obvious that the high-defect framework of graphene oxide cannot be readily utilized in applications that are governed by charge-transfer processes, for example, in solar cells. Alternatively, exfoliated graphene has been applied toward the realization of some donor–acceptor hybrid materials with photo- and/or electro-active components. The main body of research regarding obtaining donor–acceptor hybrid materials based on graphene to facilitate charge-transfer phenomena, which is reviewed here, concerns the incorporation of porphyrins and phthalocyanines onto graphene sheets. Through illustrative schemes, the preparation and most importantly the photophysical properties of such graphene-based ensembles will be described. Important parameters, such as the generation of the charge-separated state upon photoexcitation of the organic electron donor, the lifetimes of the charge-separation and charge-recombination as well as the incident-photon-to-current efficiency value for some donor–acceptor graphene-based hybrids, will be discussed.

  4. Distance-including rigorous upper bounds and tight estimates for two-electron integrals over long- and short-range operators

    Science.gov (United States)

    Thompson, Travis H.; Ochsenfeld, Christian

    2017-10-01

    We introduce both rigorous and non-rigorous distance-dependent integral estimates for four-center two-electron integrals derived from a distance-including Schwarz-type inequality. The estimates are even easier to implement than our so far most efficient distance-dependent estimates [S. A. Maurer et al., J. Chem. Phys. 136, 144107 (2012)] and, in addition, do not require well-separated charge-distributions. They are also applicable to a wide range of two-electron operators such as those found in explicitly correlated theories and in short-range hybrid density functionals. For two such operators with exponential distance decay [e-r12 and erfc (0.11 ṡr12 ) /r12], the rigorous bound is shown to be much tighter than the standard Schwarz estimate with virtually no error penalty. The non-rigorous estimate gives results very close to an exact screening for these operators and for the long-range 1/r12 operator, with errors that are completely controllable through the integral screening threshold. In addition, we present an alternative form of our non-rigorous bound that is particularly well-suited for improving the PreLinK method [J. Kussmann and C. Ochsenfeld, J. Chem. Phys. 138, 134114 (2013)] in the context of short-range exchange calculations.

  5. Distance-including rigorous upper bounds and tight estimates for two-electron integrals over long- and short-range operators.

    Science.gov (United States)

    Thompson, Travis H; Ochsenfeld, Christian

    2017-10-14

    We introduce both rigorous and non-rigorous distance-dependent integral estimates for four-center two-electron integrals derived from a distance-including Schwarz-type inequality. The estimates are even easier to implement than our so far most efficient distance-dependent estimates [S. A. Maurer et al., J. Chem. Phys. 136, 144107 (2012)] and, in addition, do not require well-separated charge-distributions. They are also applicable to a wide range of two-electron operators such as those found in explicitly correlated theories and in short-range hybrid density functionals. For two such operators with exponential distance decay [e -r 12 and erfc(0.11⋅r 12 )/r 12 ], the rigorous bound is shown to be much tighter than the standard Schwarz estimate with virtually no error penalty. The non-rigorous estimate gives results very close to an exact screening for these operators and for the long-range 1/r 12 operator, with errors that are completely controllable through the integral screening threshold. In addition, we present an alternative form of our non-rigorous bound that is particularly well-suited for improving the PreLinK method [J. Kussmann and C. Ochsenfeld, J. Chem. Phys. 138, 134114 (2013)] in the context of short-range exchange calculations.

  6. Engineering barrier materials in niobium and niobium nitride Josephson junctions for high-speed superconductor electronics

    Science.gov (United States)

    Kaul, Anupama Bhat

    Superconductor electronics promises some of the highest circuit speeds of any known digital technology. Two classes of superconducting logic families exist: voltage-state logic, and Rapid-Single-Flux-Quantum (RSFQ) logic. The ideal devices for the two logic families are fundamentally different. In this dissertation, we describe alterations in the barrier materials of the respective devices, coupled with process innovations, which lead to junctions that enable higher speed operation. For voltage-state logic, where speeds are limited by junction capacitance, a high-Jc process was developed, where thin AlOx barrier layers were formed in Nb/Al-AlOx/Nb trilayers. Small-area devices of inherently lower capacitance were fabricated, which was made possible by an anodization step, and this obviated complicated planarization techniques. This high-Jc process was used to demonstrate a clocked Josephson amplifier, whose design, simulation and high-speed test results were presented. The circuit was fabricated in a 9.4 kA/cm2 process, and was operational to speeds of at least 10 GHz. It exhibited error rates as low as 5 x 10-12 at 5 GHz, and eye diagram measurements revealed a clear-eye area, even up to 10 GHz. This Josephson amplifier represents the first circuit to be fabricated and successfully tested in a ˜10 kA/cm 2 process, and is of importance for interfacing superconductive circuitry with semiconductor electronics. While the basic device for voltage-state logic is the superconductor/insulator/superconductor (SIS) junction, the ideal device for RSFQ technology is a superconductor/normal-conductor/superconductor (SNS) junction. Since the figure of merit of this device, the IcR n, is directly influenced by the resistivity of the barrier material, high resistivity materials are desired to raise Rn, without significantly reducing Ic. We have proposed and demonstrated a new barrier material TaNx with NbN electrodes for the realization of an all-nitride SNS junction technology

  7. Mitochondrial Iron Accumulation in Parietal and Chief Cells in Iron Pill Gastritis Following Billroth II Gastrectomy: Case Report Including Electron Microscopic Examination.

    Science.gov (United States)

    Shafique, Khurram; Araujo, James L; Veluvolu, Rajesh; Cassai, Nicholas; Desoto-Lapaix, Fidelina; Pincus, Matthew R; Wieczorek, Rosemary L

    2017-05-01

    Iron pill gastritis has been shown to be associated with superficial gastric erosion and deposition of iron in lamina propria and gastric antral glands. However, iron absorption in gastric parietal and chief cells is rare. We present a case of a 62-year-old man with iron deficiency anemia. His past medical history is significant for Billroth II surgery. His medications include ferrous sulphate 325mg. Esophagogastroduodenoscopy showed diffuse circumferential abnormal mucosa at the gastro-jejunal anastomosis. The mucosa was erythematous and violaceous. Biopsy showed reactive gastropathy with iron deposits predominantly in macrophages, parietal cells, and chief cells. These findings were confirmed by iron stain and later by electron micrography of the gastric mucosa that showed iron deposits in mitochondria and cytoplasm of the parietal and chief cells. © 2017 by the Association of Clinical Scientists, Inc.

  8. GGVS. Ordinance on road transport of hazardous materials, including the European agreement on international road transport of hazardous materials (ADR), in their wording. Annexes A and B. Ordinances regarding exceptions from GGVS and from the ordinance on rail transport of hazardous materials, GGVE. Reasons. Selected guidelines. List of materials. 6. rev. and enlarged ed.

    International Nuclear Information System (INIS)

    Ridder, K.

    1990-01-01

    The brochure contains the following texts: (1) Ordinance on road transport of hazardous materials (GGVS), including the European agreement on international road transport of hazardous materials (ADR), as of 1990: Skeleton ordinance, annexes A and B, reasons given for the first version, and for the first amendment in 1988, execution guidelines - RS 002 (guidelines for executing the ordinance on road transport of hazardous materials, with catalogue of penalties), guidelines for drawing up written instructions for the event of accidents - RS 006, guiding principles for the training of vehicle conductors; (2) ordinance regarding exceptions from the ordinance on road transport of hazardous materials; (3) ordinance regarding exceptions from the ordinance on rail transport of hazardous materials; (4) selected guidelines: Technical guidelines TR IBC K 001, TRS 003, TRS 004, TRS 005, TRS 006; (5) listing of materials and objects governed by the ordinance on hazardous materials transport; (6) catalogue of penalties relative to road transport of hazardous materials. (orig./HP) [de

  9. Electron spin resonance investigaton of semiconductor materials for application in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Lihong

    2012-07-01

    In the present work, hydrogenated silicon and its alloys silicon carbide and silicon oxide have been investigated using electron spin resonance (ESR). The microstructure of these materials ranges from highly crystalline to amorphous. The correlation between the paramagnetic defects, microstructure, optical and electrical properties has been discussed. Correspondingly, these properties were characterized by the spin density (N{sub S}), g-value and the lineshape of ESR spectra, Infrared (I{sup IR}{sub C}) and/or Raman crystallinity (I{sup RS}{sub C}) as well as optical absorption and electrical dark conductivity ({sigma}{sub D}). 1. As the light absorber, Si layers essentially should have low defect density and good stability against light exposure. The spin density (N{sub S}) measured by ESR is often used as a measure for the paramagnetic defect density (N{sub D}) in the material. However, ESR sample preparation procedures can potentially cause discrepancy between N{sub S} and N{sub D}. Using Mo-foil, Al-foil and ZnO:Al-covered glass as sacrificial substrates, {mu}c-Si:H and a-Si:H films were deposited by plasma-enhanced chemical vapor deposition (PECVD), and ESR powder samples have been prepared with corresponding procedures. Possible preparation-related metastability and instability effects have been investigated in terms of substrate dependence, HCl-etching and atmosphere exposure. A sequence of 'preparation - annealing - air-exposure - annealing' has been designed to investigate the metastability and instability effects. N{sub S} after post-preparation air exposure is higher than in the annealed states, especially for the highly crystalline {mu}c-Si:H material the discrepancy reached one order of magnitude. Low temperature ESR measurements at 40 K indicated that atmospheric exposure leads to a redistribution of the defect states which in turn influence the evaluated N{sub S}. In annealed conditions the samples tend to have lower N{sub S} presumably due

  10. Toward an accurate quantification in atom probe tomography reconstruction by correlative electron tomography approach on nanoporous materials.

    Science.gov (United States)

    Mouton, Isabelle; Printemps, Tony; Grenier, Adeline; Gambacorti, Narciso; Pinna, Elisa; Tiddia, Mariavitalia; Vacca, Annalisa; Mula, Guido

    2017-11-01

    In this contribution, we propose a protocol for analysis and accurate reconstruction of nanoporous materials by atom probe tomography (APT). The existence of several holes in porous materials makes both the direct APT analysis and reconstruction almost inaccessible. In the past, a solution has been proposed by filling pores with electron beam-induced deposition. Here, we present an alternative solution using an electro-chemical method allowing to fill even small and dense pores, making APT analysis possible. Concerning the 3D reconstruction, the microstructural features observed by electron tomography are used to finely calibrate the APT reconstruction parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. A material flow analysis on current electrical and electronic waste disposal from Hong Kong households

    International Nuclear Information System (INIS)

    Lau, Winifred Ka-Yan; Chung, Shan-Shan; Zhang, Chan

    2013-01-01

    Highlights: ► Most household TWARC waste is sold directly to private e-waste collectors in HK. ► The current e-waste recycling network is popular with HK households. ► About 80% of household generated TWARC is exported overseas each year. ► Over 7000 tonnes/yr of household generated TWARC reach landfills. ► It is necessary to upgrade safety and awareness in HK’s e-waste recycling industry. - Abstract: A material flow study on five types of household electrical and electronic equipment, namely television, washing machine, air conditioner, refrigerator and personal computer (TWARC) was conducted to assist the Government of Hong Kong to establish an e-waste take-back system. This study is the first systematic attempt on identifying key TWARC waste disposal outlets and trade practices of key parties involved in Hong Kong. Results from two questionnaire surveys, on local households and private e-waste traders, were used to establish the material flow of household TWARC waste. The study revealed that the majority of obsolete TWARC were sold by households to private e-waste collectors and that the current e-waste collection network is efficient and popular with local households. However, about 65,000 tonnes/yr or 80% of household generated TWARC waste are being exported overseas by private e-waste traders, with some believed to be imported into developing countries where crude recycling methods are practiced. Should Hong Kong establish a formal recycling network with tight regulatory control on imports and exports, the potential risks of current e-waste recycling practices on e-waste recycling workers, local residents and the environment can be greatly reduced

  12. Dielectric and impedance properties of Bi(Zn2/3V1/3)O3 electronic material

    Science.gov (United States)

    Halder, S.; Parida, K.; Das, S. N.; Pradhan, S. K.; Bhuyan, S.; Choudhary, R. N. P.

    2018-03-01

    A polycrystalline vanadium doped lead free dielectric material of Bi(Zn2/3V1/3)O3 (BZV) has been prepared using a standard high-temperature solid state reaction technique. Its temperature and frequency dependent capacitive, conductive and resistive characteristics are outlined though experimental investigation. The formation of single phase compound of BZV material with orthorhombic crystal symmetry is identified through X-ray diffraction data analysis, and the homogeneous distribution of grains are realized through scanning electron micrograph. The acquaintance of frequency-temperature dependent electrical parameters with the obtained micrograph provides the experimental evidence of contributions of grain as well as grain boundary in its capacitive and resistive characteristics. The negative temperature coefficient of resistance behaviour of the material is revealed from impedance characteristic, and non-Debye type relaxation has been realized from the Nyquist plot. The charge carriers of this electronic compound have both long & short range order that has been validated from the complex modulus and impedance analysis. The prepared electronic material substantiate some important dielectric features which props up the material as promising component for electronic devices.

  13. A contribution to the electron-beam surface-melting process of metallic materials. Numerical simulation and experimental verification

    International Nuclear Information System (INIS)

    Bruckner, A.

    1996-08-01

    For the optimization of the surface melting process it is necessary to make many different experiments. Therefore, the simulation of the surface melting process becomes a major role for the optimization. Most of the simulations, developed for the laser surface melting process, are not usable for the electron-beam surface melting process, because of the different energy input and the possibility of high frequent movement of the electron-beam. In this thesis, a calculation model for electron-beam surface melting is presented. For this numerical simulation a variable volume source is used, which moves in axial direction with the same velocity as the vapor cavity into the material. With this calculation model also the high frequent movement of the electron-beam may be taken into account. The electron-beam diameter is measured with a method of drilling holes with short electron-beam pulses in thin foils. The diameter of the holes depends on the pulse length and reaches a maximal value, which is used for the diameter of the volume source in the calculation. The crack-formation, seen in many treated surfaces, is examined with the Acoustic-Emission Testing. The possibilities of the electron-beam surface melting process are shown with some experiments for different requirements of the treated surfaces, like increasing the hardness, reducing the porosity of a sintered material and the alloying of tin in an aluminium-silicon surface. (author)

  14. 2-mm Band and X-band electron spin resonance and electron spin-echo investigations of some carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Tsvetkov, Y.D.; Dzuba, S.A.; Gulin, V.I. [Institute of Chemical Kinetics and Combustion, Novosibirsk (Russian Federation)

    1993-12-31

    Argonne Premium coal samples were studied by using 2-mm band and X-band continuous-wave electron spin resonance (CW ESR) and X-band electron spin-echo (ESE) spectroscopy. The line widths and g factors (Lande g factor, spectroscopic splitting factor) were determined. The correlation between {Delta}g = g{sub {parallel}} - g{sub {perpendicular}} and the carbon content in coal samples was established. Paramagnetic centers in coals could be attributed to radicals with partial redistribution of spin density from polycyclic {pi}-system to peroxide-type structures. The degree of this redistribution depends on the degree of carbonization. Phase relaxation times, T{sub 2}, for these coals were determined by using ESE spectroscopy. 5 refs., 2 figs., 3 tabs.

  15. The development of learning material using learning goal orientation approach in digital electronics

    Science.gov (United States)

    Puspitaningayu, P.; Anifah, L.; Kholis, N.

    2018-01-01

    Mastery of digital electronics principles is essential for future engineers in the digital era. This article describes the use of simulations in an undergraduate electrical engineering course to promote the adoption of a learning-goal orientation. This study used experimental method. This was done by providing students with a simulation environment which students freely use to experiment with various circuit models. Students were then invited to reflect on how the simulation results compare with results from lab experiments. The module got 82% of positive rating from 28 students and all of them passed in the examination with 81.8 as the average score. Those majority students were motivated by the combination of two learning goals written in the module. Moreover, they also gain the ability to design more complex systems because of their combined experience. Additionally, the module also has been validated and got 83% of reliability. The final product of this research hereafter can be recommended to be used as teaching material.

  16. Treatment of nitrogen oxides by ozone treatment material using activated carbon for electron irradiation facility

    International Nuclear Information System (INIS)

    Mizuhashi, Kiyoshi; Tokunaga, Okihiro; Washino, Masamitsu; Tamura, Naoyuki

    1981-01-01

    Takasaki Radiation Chemistry Research Establishment of Japan Atomic Energy Research Institute experimentally investigated a method of removing a large amount of harmful ozone generated during irradiation, since the high output (3MV, 25mA) electron accelerator (Dynamitron) was completed, and installed an ozone treatment system. This report is described on the investigation of the effect of treating nitrogen oxides generated at the same time as ozone generation, using the ozone treatment system. First, the generated quantities of ozone and nitrogen oxides under the maximum generating conditions for these gases were calculated to be 1,130 l (2.4 kg) for ozone and 565 l (1.16 kg in terms of NO 2 ) for nitrogen oxides, respectively. The outline of the ozone treatment system, experimental procedures, and the results and their examination are described. The conclusion is as follows: Nitrogen oxides generated by irradiation can be treated nearly completely with the ozone treatment system. Most nitrogen oxides generated are adsorbed on the treatment material in the form of nitric acid. This adsorbed nitric acid can easily be leached out with hot water. Nitrogen monoxide and nitrogen dioxide generated by the irradiation of air react with ozone generated at the same time, and are rapidly oxidized to nitric acid under the presence of water. For this reason, the nitrogen oxides contained in the air in the irradiation room cannot be accurately measured with any NO or NO 2 analyzer. (Wakatsuki, Y.)

  17. 3D Magnetic Induction Maps of Nanoscale Materials Revealed by Electron Holographic Tomography.

    Science.gov (United States)

    Wolf, Daniel; Rodriguez, Luis A; Béché, Armand; Javon, Elsa; Serrano, Luis; Magen, Cesar; Gatel, Christophe; Lubk, Axel; Lichte, Hannes; Bals, Sara; Van Tendeloo, Gustaaf; Fernández-Pacheco, Amalio; De Teresa, José M; Snoeck, Etienne

    2015-10-13

    The investigation of three-dimensional (3D) ferromagnetic nanoscale materials constitutes one of the key research areas of the current magnetism roadmap and carries great potential to impact areas such as data storage, sensing, and biomagnetism. The properties of such nanostructures are closely connected with their 3D magnetic nanostructure, making their determination highly valuable. Up to now, quantitative 3D maps providing both the internal magnetic and electric configuration of the same specimen with high spatial resolution are missing. Here, we demonstrate the quantitative 3D reconstruction of the dominant axial component of the magnetic induction and electrostatic potential within a cobalt nanowire (NW) of 100 nm in diameter with spatial resolution below 10 nm by applying electron holographic tomography. The tomogram was obtained using a dedicated TEM sample holder for acquisition, in combination with advanced alignment and tomographic reconstruction routines. The powerful approach presented here is widely applicable to a broad range of 3D magnetic nanostructures and may trigger the progress of novel spintronic nonplanar nanodevices.

  18. ESR (Electronic Spin Resonance Spectroscopy) study of irradiated paper for biomedical material wrapping

    International Nuclear Information System (INIS)

    Huarte, Monica; Rubin de Celis, Emilio; Kairiyama, Eulogia; Zapata, Miguel; Santoro, Natalia; Magnavacca, Cecilia

    2009-01-01

    Ionising radiation treatments are used for sterilization, microbiological decontamination, disinfection, insect disinfestation and food preservation. This ionising radiation generates free radicals (FR) in matter, which can be detected by Electronic Spin Resonance Spectroscopy (ESR). For this work it had analysed different kind of irradiated package papers of syringes, surgical gloves and dressings by ESR. These were irradiated with doses between 20 and 35 kGy of gamma radiation (Cobalt 60). The processed samples were measured in a Bruker ECS 106 spectrometer. The obtained results were: 1-) The irritated samples showed a central peak and two satellites induced by the applied radiation; 2-) The non-irradiated samples did not show the characteristic satellite peaks of the irritated ones; 3-) A linear relationship between the signal heights per unit mass and the applied doses was found; and 4-) The signals were highly stable, with half-time values between 240 and 370 days for 20 and 30 kGy, permitting more than one year of monitoring proceedings. In conclusion, the ESR allows the detection, quantification and time monitoring processes of this kind of irradiated materials. (author) [es

  19. Phase stability and electronic structures of perovskite and organic optoelectronic materials via first-principle calculations

    Science.gov (United States)

    Luo, Heng

    Mixed ionic and electronic conductor oxides, in particular La1- xSrxCo yFe1-yO3-delta (LSCF), have been widely used as the cathode materials in solid oxide fuel cells for high-temperature energy applications. The focus of this thesis is primarily on constructing the instability phase diagram of Sr segregations on LSCF surfaces at the experimentally relevant temperatures and oxygen partial pressures using the first-principles density functional theory (DFT). A generic first-principles free-energy functional is developed to obtain the nonstoichiometric oxygen vacancy concentrations for the bulk and surface phases. These results agree well with the corresponding thermo-gravimetry measurements, and furthermore suggest that the oxygen vacancies are energetically stabilized at surfaces for all temperatures and oxygen partial pressures, while such surface stabilization effects become stronger at higher temperatures and lower oxygen partial pressures. Based on these nonstoichiometric oxygen vacancy predictions, we construct the free-energy phase diagrams of the Sr-segregation reaction as a function of temperature, oxygen partial pressure, and CO 2 partial pressure for both the bulk and surface LSCF phases. Our results suggest that Sr segregations strongly accumulate towards the LSCF surface phase where the oxygen vacancy nonstoichiometries are abundant. Our results also indicate that the Sr segregation reactions are significantly enhanced at high temperatures, low oxygen partial pressures, and high CO2 partial pressures. The computed reaction temperature ranges are consistent with the total reflection X-ray fluorescence (TXRF) measurements.

  20. A novel approach to prepare optically active ion doped luminescent materials via electron beam evaporation into ionic liquids.

    Science.gov (United States)

    Richter, K; Lorbeer, C; Mudring, A-V

    2015-01-04

    A novel approach to prepare luminescent materials via electron-beam evaporation into ionic liquids is presented which even allows doping of host lattices with ions that have a strong size mismatch. To prove this, MgF2 nanoparticles doped with Eu(3+) were fabricated. The obtained nanoparticles featured an unusually high luminescence lifetime and the obtained material showed a high potential for application.