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Increasing generation to meet the load growth and interconnections between systems to improve reliability and power transfer capability are likely to increase the fault current levels. If the resultant short circuit current exceeds the existing equipment rating, they must either be upgraded or replaced or reconfigure its system to reduce the new available fault current. Both of which are very costly or time escalated process. Hence it is preferred to explore the feasibility of utilization of existing equipment with current limiting devices. Current limiting using passive element like series inductor reduces system stability and load flow. To overcome this problem, the series reactor is made to come into services only for the duration of fault. This paper proposes new methods for fast acting current limiting using Solid State Fault Current Limiters (SSFCL) that employs power electronic switches to overcome the limitation of the passive current limiters. Modeling and simulations of these methods are performed on a typical 400 kV power system using PSCAD/EMTDC. The results of which confirm that the fault level can be effectively reduced. [ABSTRACT FROM AUTHOR]

Highly soluble and violet light emitting 1,4-Bis(benzimidazole-1-yl)benzene (BBI) was investigated theoretically and experimentally. Thin films of BBI compound were prepared using spin coating technique onto glass, quartz and silicon substrate and characterized for their structural and photo-physical properties. UV-Visible absorption studies showed that BBI molecule exhibited absorption in UV region. BBI molecules showed violet emission in solution as well as solid state form. [ABSTRACT FROM AUTHOR]

Starting in January 2017, AMADEUS (www.amadeus-project.eu) is the first project funded by the European Commission to research on a new generation of materials and solid state devices for ultra-high temperature energy storage and conversion. By exploring storage temperatures well beyond 1000 ºC the project aims at breaking the mark of ~ 600ºC rarely exceeded by current state of the art thermal energy storage (TES) systems. AMADEUS Project, through a collaborative research between seven European partners, aims to develop a novel concept of latent heat thermal energy storage (LHTES) systems with unprecedented high energy density. One of the main objectives of the project is to create new PCMs (phase change materials) with latent heat in the range of 1000-2000 kWh/m3, an order of magnitude greater than that of typical salt-based PCMs used in concentrated solar power (CSP), along with developing advanced thermal insulation, PCM casing designs, and novel solid-state heat to power conversion technologies able to operate at temperatures in the range of 1000-2000 ºC. In particular, the project will investigate Silicon-Boron alloys as PCMs and hybrid thermionic-photovoltaic (TIPV) devices for heat-to-power conversion. This paper describes the project R&D activities and the main results that have been attained during the first 6 months of work. This includes the first wettability and solubility analysis of liquid Si-B alloys, the numerical simulation of silicon phase-change and heat loss analysis through thermal insulation cover, as well as the first steps for the realization of the two main AMADEUS proof-ofconcept experiments: the TIPV converter, and the full LHTES device. [ABSTRACT FROM AUTHOR]

This study is a molecular dynamics investigation of phase change phenomena i.e. boiling of thin liquid films subjected to rapid linear heating at the boundary. The purpose of this study is to understand the phase change heat transfer phenomena at nano scale level. In the simulation, a thin film of liquid argon over a platinum surface has been considered. The simulation domain herein is a three-phase system consisting of liquid and vapor argon atoms placed over a platinum wall. Initially the whole system is brought to an equilibrium state at 90 K and then the temperature of the bottom wall is increased to a higher temperature (250K) within a finite time interval. Four different liquid argon film thicknesses have been considered (3 nm, 4 nm, 5 nm and 6 nm) in this study. The boundary heating rate (40x109 K/s) is kept constant in all these cases. Variation in system temperature, pressure, net evaporation number, spatial number density of the argon region with time for different film thickness have been demonstrated and analyzed. The present study indicates that the pattern of phase transition may be significantly different (i.e. evaporation or explosive boiling) depending on the liquid film thickness. Among the four cases considered in the present study, explosive boiling has been observed only for the liquid films of 5nm and 6nm thickness, while for the other cases, evaporation take place. [ABSTRACT FROM AUTHOR]

Cu doped SnS films were successfully fabricated using co-sputtering technique for the first time with the substrate temperature of 400 °C. Cu doping percentage is controlled by varying the dc sputtering voltage from 225V to 325V. The phase formation, surface morphology and optical properties of Cu doped SnS films were studied using X-ray diffraction, confocal Raman spectrometer, atomic force microscope and UV-Vis-NIR spectrophotometer. Structural analysis confirmed the formation of Cu doped SnS films for low dc sputtering voltage while by increasing the sputtering voltage to 325V leads to the semiconductor to metallic transition of the films as evident from optical properties. [ABSTRACT FROM AUTHOR]

The influence of processing parameters in a cast film extrusion process of thin films of isotactic polypropylene homopolymer and random propylene-ethylene copolymer was analyzed. Variation of the chill roll temperature allowed changing the supercooling of the melt and thus the generation of different crystal polymorphs of iPP. Additional focus was placed on the effect of flow induced crystallization via changing the output rate of the line. The crystal structure and morphology of the materials were evaluated and correlated to selected optical and mechanical properties. [ABSTRACT FROM AUTHOR]

The present work report a series of trivalent Europium (Eu3+) doped well crystallized perovskite CaTiO3 phosphors successfully synthesized by chemical co-precipitation method. The crystal structure was confirmed by X-ray diffraction (XRD) which is in good agreement with pure orthorhombic phase with space group Pbnm, and it also indicated that the incorporation of the dopant did not affect the crystal structure. The impact of doping on the photoluminescence performances of the sample has been investigated by emission, excitation, and diffuse reflectance spectra at the room temperature. Photoluminescence spectra of Eu3+ doped CaTiO3 nanophosphor revealed the characteristic emission peak around wavelength 618nm in the visible region upon the excitation of near-UV light at wavelength 397nm due to 5D0 → 7F2 transition in Eu3+. It was further proved that the dipole- dipole interactions results in the concentration quenching of Eu3+ in CaTiO3:Eu3+ nanophosphors. The elemental composition of sample carried out by energy dispersive spectroscopy (EDS). EDS analysis reveals that the Eu3+ doped successfully into host CaTiO3. The experimental result reveals that prepared nanophosphor can be used in the application of solid state lighting devices. [ABSTRACT FROM AUTHOR]

A novel method to prepare orthophosphate LiSrPO4: Eu2+ phosphor for white light-emitting diodes (w-LEDs) is given in this paper. Phosphor was successfully synthesized by Pechini (citrate gel) method which is efficient than conventional high temperature solid state reaction. X-ray powder diffraction (XRD) analysis confirmed the single phase formation of LiSrPO4:Eu2+ with monoclinic crystal structure. Luminescence results showed that the phosphor could be efficiently excited by near UV and exhibited bright blue emission at λem= 420 nm corresponding to 5d- 4f transition of Eu2+. The phosphor exhibits blue emission bands under 350 nm excitation. This mercury-free excitation is useful for solid state lighting and light-emitting diode (LED). Hence it could be useful for solid state lighting and light-emitting diode (LED) application. [ABSTRACT FROM AUTHOR]

We synthesized [LnIII(hfac)3(H2O)(L)] (abbreviated as Ln-L; Ln = Gd, Tb, Eu; L = DTBK (di-t-butyl ketone), BP (benzophenone)), in which the carbonyl oxygen atom was coordinated to the Ln ion center, despite of such bulky substituents. Their crystal structures were determined by means of X-ray diffraction study. Gd-DTBK is completely isomorphous to the di-t-butyl nitroxide derivative and accordingly can be regarded as a model with the ligand spin masked. The ac magnetic susceptibility measurements on Tb-DTBK and -BP showed frequency dependence, characteristic of single-ion magnets. They also displayed photoluminescence in the solid state at room temperature. The quantum yields of the luminescence of Tb-DTBK and -BP (λex = 360 nm) were improved to 57 and 35%, respectively, from that of the starting material [TbIII(hfac)3(H2O)2] (28% atλex = 370 nm). Similarly, the quantum yields for Eu- DTBK and -BP were 8 and 15%, respectively, with λex = 400 nm, while that of the starting material [EuIII(hfac)3(H2O)2] was 4% at λex = 400 nm. [ABSTRACT FROM AUTHOR]

The structural, dielectric and ferroelectric properties of BiFeO3 and BiMnxFe1-xO3 with x = 0.03 samples synthesized by the conventional solid state reaction method has been studied. The XRD pattern clearly shows the suppression of impurity phases with the substitution of Mn at Fe - site. Dielectric properties of the samples in frequency range 4 Hz - 1 MHz has been measured at room temperature. A strong dispersion was observed in the dielectric constant at low frequencies due to Maxwell-Wagner type of interfacial polarization. At higher frequencies, dielectric constant shows frequency independent behavior indicating an intrinsic dielectric response. The BiMn0.03Fe0.97O3 sample exhibit loosy and unsaturated ferroelectric loop at room temperature due to the presence of oxygen vacancies. [ABSTRACT FROM AUTHOR]

Microelectronic industry is driven by the continuous miniaturization process conducing to the introduction of new materials. These materials are subjected to stresses mainly due to thermal mismatch, microstructural changes or process integration which can be in the origin of mechanical reliability issues. To study these phenomena and even electromigration a good mechanical characterization of the materials is needed. This work aims at developing tests to assess fracture or elastoplastic behavior of thin and very thin metallic and polymeric films. The tests developed are based on indentation combined with sample preparation using mostly FIB. Among other techniques, different test geometries for microbeams have been evaluated and quantitative data have been obtained combining experimental results with analytical or numerical models, depending on the material under study. For the particular case of Cu cantilevers, a strong dependence of their plastic behavior on the orientation of the grains close to the fixed end has been detected. Grain orientation has been measured by EBSD and the plastic behavior has been modeled by FEM using an in-house crystal plasticity subroutine. [ABSTRACT FROM AUTHOR]

We outline the various ingredients which have enabled LED-based solid state lighting with remarkable efficiency. The major breakthrough was the appearance of high performance nitride LEDs, despite rather unpromising early materials data. [ABSTRACT FROM AUTHOR]

The recent decade has seen a doubling of the efficiency of thermoelectric converters through the use of nanotechnology. Here we first outline how specific doping impurities in semiconductors, called resonant levels, mimic the effects of nanostructures and give the same benefits in bulk semiconductors. Resonant impurities catalyse the formation of new bands in semiconductors, which can be engineered to tailor the thermopower. The result is an efficiency increase of 50% in BiSb and more in PbTe. Then, we describe a new solid-state heat-to-electricity conversion mechanism, the spin-Seebeck effect, which arises from driving spinpolarized particles out of thermal equilibrium. This generates a spin flux that is converted into a voltage in a non-polarized adjacent material; the effect can be as large as the highest thermoelectric voltages in semiconductors. Nanotechnologies and these new effects add new design variables to the old problem of optimizing the thermoelectric figure of merit, resulting in much improved thermal efficiencies. [ABSTRACT FROM AUTHOR]

Technologies for artificial lighting have made tremendous progress over the centuries. At this point in time, there is virtually no question that solid-state lighting (SSL) will eventually displace its predecessor technologies. A remaining question, however, is what the final efficiency of SSL will be. In this talk, we give a perspective on the future of SSL, with a focus on ultra-high(>70%) efficiencies. We ask, and sketch answers to, three questions. First, what are some of the likely characteristics of ultra-efficient SSL? Second, what are some of the economic benefits of ultraefficient SSL? And, third, what are some of the challenges associated with various possible technological approaches to ultra-efficient SSL? [ABSTRACT FROM AUTHOR]

Over the last ten years, researchers at USD have investigated a series of challenges to the second law of thermodynamics that involve the exploitation of intense vacuum electric fields generated by solid-state diodic contacts [1, 2, 3]. Although theoretical arguments and numerical simulations supported the existence of these fields, experimental verification had been lacking. This article reviews the theoretical basis for these diodic electric fields and details recent laboratory experiments that have verified their location, intensity, and rechargability. [ABSTRACT FROM AUTHOR]

Silicon's intersection with biology is a premise inherent in Moore's prediction. Distinct from biologically inspired molecular logic and storage devices (more Moore) are the integration of solid state electronic devices with the soft condensed state of the body (more than Moore). Developments in biomolecular recognition events per sq. cm parallel those of Moore's Law. However, challenges continue in the area of 'More than Moore'. Two grand challenge problems must be addressed-the biocompatibility of synthetic materials with the myriad of tissue types within the human body and the interfacing of solid state micro- and nano-electronic devices with the electronics of biological systems. Electroconductive hydrogels have been developed as soft, condensed, biomimetic but otherwise inherently electronically conductive materials to address the challenge of interfacing solid state devices with the electronics of the body, which is predominantly ionic. Nano-templated interfaces via the oriented immobilization of single walled carbon nanotubes (SWCNTs) onto metallic electrodes have engendered reagentless, direct electron transfer between biological redox enzymes and solid state electrodes. In addressing these challenges, metrology needs and opportunities are found in such widely diverse areas as single molecule counting and addressing, sustainable power requirements such as the development of implantable biofuel cells for the deployment of implantable biochips, and new manufacturing paradigms to address plura-biology needs on solid state devices. [ABSTRACT FROM AUTHOR]

Constitutive models which describe crystal microplasticity in a continuum framework can be envisaged as average representations of the dynamics of dislocation systems. Thus, their performance needs to be assessed not only by their ability to correctly represent stress-strain characteristics on the specimen scale but also by their ability to correctly represent the evolution of internal stress and strain patterns. In the present comparative study we consider the bending of a free-standing thin film. We compare the results of 3D DDD simulations with those obtained from a simple 1D gradient plasticity model and a more complex dislocation-based continuum model. Both models correctly reproduce the nontrivial strain patterns predicted by DDD for the microbending problem. [ABSTRACT FROM AUTHOR]

We describe progress on an array-based microsensor approach employed for detecting trace levels of toxic industrial chemicals (TICs) in air-based backgrounds with varied levels of humidity, and with occasional introduction of aggressive interferents. Our MEMS microhotplate arrays are populated with multiple chemiresistive sensing materials, and all elements are programmed to go through extensive temperature cycling over repetitive cycles with lengths of approximately 20 s. Under such operation, analytically-rich data streams are produced containing the required information for target recognition. [ABSTRACT FROM AUTHOR]

The integration of magneto-resistive sensors into eddy current probes can significantly expand the capabilities of conventional eddy current nondestructive evaluation techniques. The room temperature solid-state sensors have typical bandwidths in the megahertz range and resolutions of tens of microgauss. The low frequency sensitivity of magneto-resistive sensors has been capitalized upon in previous research to fabricate very low frequency eddy current sensors for deep flaw detection in multilayer conductors. In this work a modified probe design is presented to expand the capabilities of the device. The new probe design incorporates a dual induction source enabling operation from low frequency deep flaw detection to high frequency high resolution near surface material characterization. Applications of the probe for the detection of localized near surface conductivity anomalies are presented. Finite element modeling of the probe is shown to be in good agreement with experimental measurements. [ABSTRACT FROM AUTHOR]

The Integrated Circuits Design Research Laboratory at Southern Illinois University Edwardsville (SIUE) has been collaborating over the past several years with the Nuclear Reactions Group at Washington University (WU) on the development of a family of custom, multi-channel Integrated Circuits (ICs). To date, the collaboration has successfully produced two micro-chips. The first was an analog shaped and peak sensing chip known as HINP16C (Heavy Ion Nuclear Physics-16 Channel). The second chip, christened PSD8C (Pulse Shape Discrimination-8 Channel), was designed to logically complement (in terms of detector types) the HINP16C chip. The HINP16C chip, for use with solid-state detectors, produces sparsified analog pulse trains for both linear (pulse height) and timing (relative to an external reference) signals. A shaper and peak detector are implemented in the linear branch, and a pseudo Constant-Fraction Discriminator (CFD) and Time-to-Voltage Converter (TVC) are implemented in the logic/timing branch. The internal and external gain options make the chip suitable for use in a wide variety of applications. PSD8C greatly simplifies the pulse-processing electronics needed for large arrays of scintillation detectors. As the PSD8C employs user-controlled, multi-region charge integration, particle identification is inherent in the design. Each of the three pulse-height sub-channels consists of a gated integrator with eight programmable charging rates and an externally programmable gate generator that defines the start (with 4 time ranges) and the width (with 4 time ranges) of the gate, relative to an external discriminator signal. Moreover, each channel on the chip also contains a TVC. This paper describes the design, capabilities, and features of the HINP16C and PSD8C ICs along with a description of how the chips are being used. It also discusses modifications and enhancements which have been made to both chips and their associated prototypical systems in order to improve ease of use and increase performance. [ABSTRACT FROM AUTHOR]

In the present paper we demonstrate the use of electron backscatter diffraction (EBSD) for high resolution elastic strain determination. Here, we focus on analysis methods based on determination of small shifts in EBSD pattern with respect to a reference pattern using cross-correlation algorithms. Additionally we highlight the excellent spatial and depth resolution of EBSD and introduce the use of simulated diffraction patterns based on dynamical diffraction theory for sensitivity estimation. Moreover the potential of EBSD for strain analysis of strained thin films with particular emphasis on appropriate target preparation which respect to occurring lattice defects is demonstrated. [ABSTRACT FROM AUTHOR]

The Solid State Devices (SSD) which are increasingly being adopted in today's data storage Systems, have higher capacity and performance but lower reliability, which leads to more frequent rebuilds and to a higher risk. Although SSD is very energy efficient compared to Hard Disk Drives but Bit Error Rate (BER) of an SSD require expensive erase operations between successive writes. Parity based RAID (for Example RAID4,5,6)provides data integrity using parity information and supports losing of any one (RAID4, 5)or two drives(RAID6), but the parity blocks are updated more often than the data blocks due to random access pattern so SSD devices holding more parity receive more writes and consequently age faster. To address this problem, in this paper we propose a Model based System of hybrid disk array architecture in which we plan to use RAID 4(Stripping with Parity) technique and SSD drives as Data drives while any fastest Hard disk drives of same capacity can be used as dedicated parity drives. By this proposed architecture we can open the door to using commodity SSD's past their erasure limit and it can also reduce the need for expensive hardware Error Correction Code (ECC) in the devices. [ABSTRACT FROM AUTHOR]

Epitaxial thin film growth by vapor deposition or molecular beam epitaxy under ultra-high vacuum conditions generally occurs in two stages: (i) nucleation and growth of well-separated islands on the substrate; (ii) subsequent formation of a thicker continuous film with possible kinetic roughening. For homoepitaxial growth, two-dimensional (2D) monolayer islands are formed during submonolayer deposition. Typically, the presence of a step-edge barrier inhibits downward transport and leads to the formation of mounds (multilayer stacks of 2D islands) during multilayer growth. For heteroepitaxial growth, islands formed in the initial stages of deposition sometimes have a 2D monolayer structure. However, they may instead exhibit bilayer or 3D multilayer structure due to, e.g., a high film surface energy, strain, or quantum size effects. Various growth modes are possible for thicker films. Atomistic modeling provides the most detailed picture of film growth. For coherent (defect-free) epitaxial films, lattice-gas modeling analyzed by kinetic Monte Carlo simulation (KMC) is particularly successful in describing film growth on the appropriate time and length scales. For large islands or complex systems, another effective and instructive approach is laterally coarse-grained step-dynamics modeling which tracks only the evolution of step edges in each layer. However, fully coarse-grained 3D continuum modeling for the evolution of a film height function does not yet have predictive capability. Examples are provided for: Ag homoepitaxy on (100), (111) and (110) surfaces; Ag heteroepitaxy on lattice-matched substrates including NiAl(110), NiAl(100), and Fe(100); and Ag heteroepitaxy on 5-fold icosohedral Al-Pd-Mn and 2-fold decagonal Al-Cu-Co quasicrystalline surfaces. [ABSTRACT FROM AUTHOR]

The metalorganic vapor phase epitaxy of semiconductor materials has been developed over the past three decades and has focused on the synthesis of semiconductors and alloys useful in the formation of optoelectronic and high speed electronic devices. These materials are currently binary semiconductors or alloys which have broad miscibility. The extension to alloy systems which are highly immiscible in bulk form requires modification to conventional growth systems preventing the nucleation and growth of multiple compositional phases. The general features of MOVPE as it relates to the growth of complex alloys is developed within the current framework of MOVPE technology. [ABSTRACT FROM AUTHOR]

A phase composition of ∼10 nm thick Fe film placed on the silicon substrate with 200 nm thick SiOx layer after annealing in vacuum and in H2+CH4 was investigated using Conversion Electron Mössbauer spectroscopy (CEMS). CEMS spectra show that the original iron film was formed by Fe3+ phase. This phase is stable after the annealing in vacuum or in H2+CH4 below 500 °C but formation of phases with Fe2+ and Fe0 (γ-Fe and α-Fe) was observed after annealing at 500 °C and higher temperatures. Formation of fayalite (Fe2SiO4) occurred during vacuum annealing at 700 °C. SEM and CEMS study of the sample with grown multi-walled carbon nanotubes shows that the dominating part of iron atoms is present in Fe3C and Fe5C2 carbide phases. Besides their stoichiometric forms, the spectrum components which can be ascribed to the amorphous Fe5-xC2+x carbides, γ-Fe, and Fe3+ were observed. [ABSTRACT FROM AUTHOR]

Thin film Al/(p)Bi2S3 Schottky junctions were prepared by vacuum evaporation under pressure 10-6 Torr. The p-type Bi2S3 thin films with acceptor concentration (3.36-7.33)×1016/cm3 were obtained by evaporating ‘In’ along with Bi2S3 powder and then annealing the films at 453K for 5 hours. Different junction-parameters such as ideality factor, barrier height, effective Richardson’s constant, short-circuit current, etc. were determined from I–V characteristics. The junctions exhibited rectifying I–V characteristics and also photovoltaic effect. Ideality factor was found to decrease with the increase of temperature. Proper doping, annealing, and hydrogenation are necessary to reduce the series resistance so as to achieve high carrier efficiency. More works are being carried out in this direction. [ABSTRACT FROM AUTHOR]

The article focuses on the thermo-analytical investigations on high temperature superconductors of Yttrium Barium Copper Oxide (YBCO) family. The YBCO had been the most investigated high temperature superconductors (HTSC) system till date due to its application potential, low refrigeration cost and easy characteristics. There had been continuous efforts to improve to have a dense microstructure with large grain size and small pore fraction to ensure better intergrain connectivity.

Thick and thin films of trans-polyisoprene (TPI) have been prepared using solution casting method by dissolving TPI in toluene. Thick films of TPI have been used to determine thermal transport properties at different temperatures through Thermal Constant Analyzer (TCA). The results show that thermal conductivity, thermal diffusivity and volumetric heat capacity increase with respect to temperature. Thin films of TPI on the other hand have been utilized for the measurement of mechanical properties such as Young’s modulus, tensile strength and toughness. The effect of temperature on the mechanical properties of thin films of TPI has been investigated using Dynamic Mechanical analyzer (DMA) and it was found that the mechanical properties decrease with increasing temperature. Above said behavior of the thermal transport and mechanical properties as a function of temperatures is attributed to the increase in free volume of molecules in chains with temperature. [ABSTRACT FROM AUTHOR]

A straightforward application of an electron energy analyzer equipped with an image detector to micron-resolved electron spectroscopic studies of organic thin film devices is reported. The electron spectroscopies implemented include synchrotron-based UPS, XPS, and Auger yield NEXAFS. Along the non-energy-dispersion direction of the analyzer, a spatial resolution of ∼40 μm is obtained through the employment of entrance slits, electrostatic lenses and segmented CCD detector. One significant benefit offered by the technique is that the electronic transport and electronic structure of the same micron-sized sample can be directly examined. The example illustrated is a top-contact organic field effect transistor (OFET) fabricated from semiconducting triethylsilylethynyl anthradithiophene and gold electrodes. It is found that an extensive out-diffusion of gold atoms to adjacent conduction channels takes place, presumably due to the inability of soft organic materials in dissipating the excess energy with which gaseous Au atoms possess. [ABSTRACT FROM AUTHOR]

We proposed a new type of undulator based on bulk high-Tc superconductors (HTSC) which consists of a single solenoid and a stacked array of bulk HTSC. The main advantage of this configuration is that a mechanical structure is not required to produce and control the undulator field. In order to perform a proof of principle experiment, we have developed a prototype of bulk HTSC staggered array undulator using 11 pairs of DyBaCuO bulk superconductors and a normal conducting solenoid. Experimental results obtained by using the prototype undulator and numerical results obtained by a loop current model based on the Bean mode for a type-II superconductor were compared. [ABSTRACT FROM AUTHOR]

High-temperature superconductors allow a compact and efficient way to provide high-torque density to rotating machines with excellent operation. A field pole, providing flux density of more than 1.5 T around the armature, was initially designed for an axial-gap type with the flux parallel to the rotor axis. Melt-growth Gd-123 bulks as well as Bi-2223 wire windings have been successfully assembled on the rotor disk. No iron core was used, though being an auxiliary flux control found in most HTS motors. Both bulk and wire types have realized a practical motor operation within a limited output range. For bulks, a 15 kW, 720 rpm, synchronous motor was designed and tested in the group of TUMSAT, Kitano Seiki and University of Fukui. A bulk field pole was cooled down by liquid nitrogen and was magnetized in the motor. To enhance the output power to more than 30 kW, we developed a thermosyphon system using condensed neon. Another field pole with HTS wire for large-scale marine propulsion is also discussed on a 100 kW, 230 rpm tested machine. A closed-cycle condensed neon associated with thermal insulation is also reported. [ABSTRACT FROM AUTHOR]

A guarded-hot-plate apparatus has been developed to measure the thermal conductivity of various spray-on foam insulations (SOFI) at temperatures ranging from 20–300 K. The apparatus is designed to accept 222 mm (8.75″) diameter, 25.4 mm (1″) thick insulation samples, although different thicknesses can be accommodated. The apparatus is cooled with a two stage, pulse tube cryocooler, and the temperature is controlled with thin film etched foil heaters. This system allows thermal conductivity measurements to be made at low delta-T (ΔT<20 K) throughout the temperature range. Platinum and Cernox™ sensors are used to measure the temperature difference across the sample and to monitor other temperatures throughout the apparatus. Multiple thermal guards are employed to confine heat flow axially through the sample. A gas handling system allows testing with different residual gases and pressures. To check for potential systematic errors, a finite element analysis was performed to examine temperature distribution and heat flow in the experimental chamber. [ABSTRACT FROM AUTHOR]

Landau’s work was crucial for the development of the modern theory of phase transitions. He showed that such transitions can be classified by an order parameter, which in the low-temperature phase becomes nonzero. Together with Ginzburg he made this order parameter a spacetime-dependent order field and introduced a local energy functional whose extrema yield field equations and whose fluctuations determine the universal critical behavior of second-oder transitions. In the same spirit, but from a dual point of view, I have developed in the last twenty years a disorder field theory that describes phase transitions via the statistical mechanics of grand-canonical ensembles of vortex lines in superfluids and superconductors, or of defect lines in crystals. The Feynman diagrams of the disorder fields are pictures of the vortex or defect lines. A nonzero ground state expectation value of the disorder field at high temperature signalizes the proliferation of line like excitations in the ordered phase. It was this description of the superconductor that led in 1982 to a first understanding of the order of the superconducting phase transition. Recent experimental progress in the critical regime of high-Tc superconductors will be able to verify the predicted tricritical point of the Ginzburg parameter κ≈0.8/2 where the second-order transition becomes first-order. [ABSTRACT FROM AUTHOR]

This paper is presented the properties of amorphous carbon (a-C) thin films for solar cell application. Amorphous carbon thin films have been deposited on silicon substrate by thermal chemical vapor deposition (thermal-CVD) method at various deposition temperatures. The surface morphology, electrical properties and crystallinity of these films have been studied using Analytical Scanning Electron Microscope (SEM) JEOL JSM-6360LA, Current Voltage (I-V) Measurement (Advantest R6243 DC Voltage Current Source/Monitor Software) and the D5000 Siemen Difractrometer (XRD) respectively . It was found that increasing deposition temperature had the most influence on the a-C thin films properties. In addition the carrier gas flow also showed a secondary impact on the properties of a-C thin films. [ABSTRACT FROM AUTHOR]

Ultra-violet laser direct writing provides a powerful way of creating integrated optical devices. The work reported here describes developments in this field, and particularly the use of two-beam writing to create Bragg gratings in planar integrated format. The work shows how these structures can be used in a wide range of applications, ranging from creation of wide-band couplers, through to extremely sensitive sensor devices. UV direct writing removes many of the constraints normally associated with planar integrated optics. It is a mask-free process that uses direct computer control and it dispenses with the etching steps normally required to make low-loss waveguide devices. The work reported will show how this flexibility of format may be combined with novel substrate structures to allow new device types. [ABSTRACT FROM AUTHOR]

The effects of rf power on the hydrogen bonding and structural order in hydrogenated silicon (Si:H) thin films prepared by plasma enhanced chemical vapor deposition (PECVD) from silane highly diluted with hydrogen have been studied. The radio-frequency, rf power was varied from 20 to 100 W representing power densities of 0.7 to 3.5 mW/cm2 for our home-built rf PECVD system. The structure and hydrogen bonding properties of the films were studied using Fourier transform infrared and micro-Raman scattering spectroscopy. The hydrogenated silicon films showed dominant presence of monohydride bonds indicating homogeneity of the amorphous component of the films. Rf powers of 40 and 60 W produced films with the low hydrogen content and increased concentration of polyhydrides bonds. The crystalline volume fraction decreased with increase in rf power and structural order was enhanced for the films prepared at rf power of 40 and 60 W. [ABSTRACT FROM AUTHOR]

Codoped ZnO thin films were prepared on silicon (111) substrates by cosputtering of aluminium rods and zinc target using DC magnetron sputtering followed by heat treatment at 400° C for 1 hour at different ratios of oxygen and nitrogen gas. Results indicate that gas ratios influenced the film conduction properties, which had the lowest resistivity of 7.985×10-3 cm-3 and highest carrier concentration of 6.89×1021 cm-3. [ABSTRACT FROM AUTHOR]

Surface morphology study of Zinc Oxide (ZnO) thin films by using Thermal Chemical Vapor Deposition (Thermal-CVD) was investigated. The ZnO compound was synthesized from zinc acetate dehydrate which act as a starting material to form the ZnO thin films. It was deposited on as-prepared Nanonstructured Silicon (NSi) with deposition temperature ranging from 400–600° C without catalyst-assisted. The surface morphology of the samples before and after the deposition process was examined by using Analytical Scanning Electron Microscope (SEM). The result shows that the obtained ZnO thin films possess good crystalline structure at deposition temperature of 600° C and the surface morphologies of the ZnO thin films improved greatly with an increase in deposition temperature. XRD was employed to study the evolution of the crystalline orientation using X-Ray Diffractrometer (XRD). [ABSTRACT FROM AUTHOR]

The effects of Lithium triflate salt (LiCF3SO3), on the poly (methyl methacrylate) (PMMA)-based solid polymer electrolytes plasticized with propylene carbonate (PC) solvated in Tetrahydrofuran (THF) have been studied through a.c impedance spectroscopy and infrared spectroscopy. Lithium triflate was incorporated into the predetermined PMMA/PC system that has the highest value of ionic conductivity. In current investigations, four combination systems: Pure PMMA, (PMMA+PC) systems, (PMMA+LiCF3SO3) and (PMMA+PC+LiCF3SO3) systems were prepared using the solution cast method. Solutions were stirred for numerous hours to obtain a homogenous solution before it is poured into the petri dishes under ambient temperature to form the solid electrolyte thin film. The films were then removed from petri discs and transferred into the dessicator for further drying prior to the different tests. From the characterization done through the a.c impedance spectroscopy, the highest room temperature ionic conductivity in the pure PMMA sample, (PMMA+PC) system and (PMMA+LiCF3SO3) system is 2.83×10-12 Scm-1, 4.39×10-11 Scm-1 and 3.93×10-6 Scm-1 respectively. The conductivity for (PMMA+PC+LiCF3SO3) system was obtained with the 30 wt% of lithium triflate, which is 2.48×10-5 Scm-1. Infrared spectroscopy shows that complexation occurred between the polymer and the plasticizer, and the polymer and plasticizer and salt. The interactions have been studied in the C==O band, C[Single_Bond]O[Single_Bond]C band and the O[Single_Bond]CH3 band. [ABSTRACT FROM AUTHOR]

Electrical properties and surface morphology study are investigated for titanium dioxide thin films prepared using sol gel method. Titanium dioxide thin films were deposited on glass and silicon substrates by spin coating technique. The result indicated electrical properties of titanium dioxide thin films were changed with different substrates, annealing temperatures, and glacial acid concentrations. The SEM investigation showed that grain size of titanium oxide increased with higher volume of glacial acetic acid and higher annealing temperature up to 450° C. The results suggest that electrical properties and surface morphology of titanium dioxide could be tailored by using different substrates, modifying glacial acid volume and changing annealing temperatures for electronic devices application. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) films were synthesized by thermal oxidation of metallic zinc films in normal atmosphere at 600° C. The influence of oxidation time ranging from 1 to 3 hr on the structural and optical properties of ZnO films was investigated. The films show polycrystalline structure with c axis preferred orientation. The energy band gap for the prepared films seem to be unaffected by the time duration of the oxidation process and was equal to 3.25±0.02 eV. [ABSTRACT FROM AUTHOR]

In this work, LiMn1.9Fe0.1O4 and LiMn1.5Fe0.5O4 were prepared by sol-gel method according to proper stoichiometric ratio. It is then calcined at 850° C for 24 hours. Characterization studies of final products were done using XRD, FESEM, cyclic voltammetry (CV) and charge—discharge characteristics. Phase composition of the samples were studied from the XRD patterns obtained. For the microstructural studies, FESEM results show an average particle size of the bulk particles. From the charge—discharge characteristics, it showed that these samples exhibited good discharge capacities. [ABSTRACT FROM AUTHOR]

ZnO thin films were fabricated by the sol-gel method using Zn(CH3COO)2.2H2O (zinc acetate) as starting material. A homogenous and stable solution was prepared by dissolving the zinc acetate in a solution of ethanol and ethanolamine. Deposition of ZnO solution on Si substrate was performed by spin-coating technique and annealed at various temperatures from 200° C to 600° C. The surface morphologies and structural properties of the obtained product were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM analysis showed that the surface boundaries of ZnO thin films were decreased with the increasing of annealing temperature. X-ray analysis showed that the crystallinity of ZnO thin films increased with increasing annealing temperature. The effect of annealing temperature of ZnO thin films was studied. [ABSTRACT FROM AUTHOR]

ZnO thin films were deposited onto corning glass substrates by rf magnetron sputtering system using ZnO targets. Films were deposited under rf power of 80 W at various deposition time. The distance between the target and substrate was held at 45 cm. A mixed Ar and O2 gas was introduced into the chamber at 4×10-2 Torr. The structure of the deposited ZnO films was investigated by Scanning electron miscroscopy. The gas sensing properties were evaluated at various operation temperatures by measuring the changes of resistance of the sensor in air and in CO gas respectively using the gas sensing characterization system. The grain size was increased as the film thickness was increased during deposition. The sensor with 233 nm film thickness exhibited the highest sensitivity for CO gas. [ABSTRACT FROM AUTHOR]

This paper correlates nonlinear material properties to nondestructive electronic measurements by using wave analysis techniques (e.g. Perturbation Methods) and incorporating higher-order phenomena. The correlations suggest that nondestructive electronic property measurements and practices can be used to assess thin films, surface layers, and other advanced materials that exhibit modified behaviors based on their space-charged interfacial behavior. [ABSTRACT FROM AUTHOR]

In this investigation, the gas-sensing properties of TiO2 thin layers are enhanced by Ag-doping. The TiO2 layers are prepared by the method of Liquid Phase Deposition (LPD) through a reaction between the metal fluorocomplex and boric acid in aqueous solution. The LPD-TiO2 layers are grown on AT-cut quartz resonators with gold electrodes (4 mm diameter). The prepared samples are divided in two (Ag-Doped TiO2 and un-doped TiO2) groups. The Ag-doped TiO2 thin films are created by vertically dipping in AgNO3 diluted water solution and UV irradiation with nine lamps of 6 W power each and light intensity of 0.35 mW/cm2 at room temperature. The sensing properties of two kinds of layers (Ag-doped TiO2 and un-doped TiO2) to NH3 are being studied by the method of Quartz Crystal Microbalance (QCM). The experiments are implemented at different NH3 concentrations—from 10 to 1000 ppm on a special laboratory set-up in dynamic regime. Comparing the results of measured sorbed mass of both kinds of layers show that the sensitivity of TiO2 is significantly affected by Ag presence. The role of Ag is to generate more active surface for TiO2 sorption. The obtained results show that the system QCM—LPD Ag TiO2 can be successfully applied as sensor element for NH3 registration in environment. [ABSTRACT FROM AUTHOR]

The sensitivity of thin Ge-As-S films to ammonia was investigated by the quartz crystal microbalance (QCM) using 16 MHz AT-cut quartz resonators. Films with appropriate composition are consecutively deposited on each side of the QCM by vacuum thermal evaporation with a rate of 50 Å/s. The previously synthesized Ge-As-S glass was used as source of evaporation. The sorption properties of the as-deposited films as well as irradiated ones were investigated. The films were exposed to a HBO Hg lamp through an IR cut-off filter, for 45 min on each of the QCMs sides. The applied power density of irradiation was 0.12 W/cm2. The sorption properties of Ge-As-S films were investigated in NH3 concentration interval from 10 ppm to 10000 ppm in a specially designed set-up for measurement of QCM mass-loading in dynamic regime. It has been determined that the sorption properties to NH3 are only observed in the irradiated Ge-As-S films. A considerable response to NH3 was detected at concentrations over 250 ppm, where the measured frequency change (ΔF) of QCM is 15 Hz, while at 10000 ppm ΔF reaches value of 173 Hz. Based on the measured frequency-time characteristics (FTCs) of QCM the processes of sorption were studied. The sorption and desorption velocity and absorbed NH3 mass for each of the investigated concentrations were calculated. The obtained results show that thin Ge-As-S films could be used as gas sensor elements for detection of NH3 concentrations higher than 250 ppm. [ABSTRACT FROM AUTHOR]

In recent years, thermoelectricity sees rapidly increasing usages in applications like portable refrigerators, beverage coolers, electronic component coolers etc. when used as Thermoelectric Cooler (TEC), and Thermoelectric Generators (TEG) which make use of the Seebeck effect in semiconductors for the direct conversion of heat into electrical energy and is of particular interest for systems of highest reliability or for waste heat recovery. In this work, we examine the performance of commercially available TEC and TEG. A prototype TEC-refrigerator has been designed, modeled and constructed for in-car applications. Additionally, a TEG was made, in order to measure the gained power and efficiency. Furthermore, a TEG module was tested on a small size car (Toyota Starlet, 1300 cc), in order to measure the gained power and efficiency for various engine loads. With the use of a modeling approach, we evaluated the thermal contact resistances and their influence on the final device efficiency. [ABSTRACT FROM AUTHOR]

MxOy(M:Co, Mn, Nd)-doped SiO2 thin films were prepared by sol-gel method on glass substrates using Si(OC2H5)4 (tetraethylorthosilicate, TEOS,) as starting material. Si(OC2H5)4 was dissolved in ethanol and thus, precursor solution was prepared. Various layers of coatings were obtained at room temperature by sol-gel dip-coating process at a withdrawal speed of 10 cm/min. The coated substrates were exposed to heat treatment at 650° C. Structural and optical properties of the films were examined by UV-VIS (Lamda 2S Spectrophotometer), AFM (Atomic Force Microscopy) and SE (Spectroscopic Ellipsometry) [ABSTRACT FROM AUTHOR]