Energy Technology Data Exchange (ETDEWEB)

Silica microspheres were deposited into two-dimensional periodic arrays and coated with a thin layer of silicon nanocrystals. The luminescence from the silicon nanocrystals coupled into the whispering gallery modes of the spheres, with Q factors that depended on a range of parameters including sphere size, position on the sphere, viewing direction, and thickness of the nanocrystal coating. Scattering from the film-sphere and/or the sphere-substrate contacts resulted in a lower Q for modes that intersect these regions. The highest Q factors obtained in this work were {approx}1500. The results suggest that silica microspheres may be promising candidates for high-Q cavities that incorporate silicon nanocrystals for cavity QED or nonlinear optical effects.

British Library Electronic Table of Contents (United Kingdom)

The dependence of melting temperature T m on the size and shape of an n -dimensional nanocrystal of elementary single-component substance is studied. The nanocrystal has the form of an n-dimensional parallelepiped with a square base. The ratio of the length of side rib to the length of base rib (which is equal to f) defines the form of the system. It is demonstrated that, if the surface pressure is ignored, the value of T m decreases with isomorphic (f = const) decrease in the size of nanocrystal. In so doing, the more the value of form parameter f deviates from unity, the more appreciable the size dependence of T m will be. However, if the surface pressure (?Laplace pressure??) is taken into account in the case of decrease in size, the value of T m may vary significantly. In so doing, if ...

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British Library Electronic Table of Contents (United Kingdom)

Si nanocrystal floating gate MOS capacitors were formed on p-Si (100) wafers by thermal plasma jet (TPJ) annealing of SiO2/SiOx /SiO2/Si(100) stacked structure. The chemical composition of SiOx layer was controlled by changing the SiH4, He, and O2 gas flow ratio during plasma enhanced chemical vapour deposition. The MOS capacitors showed clear hysteresis in capacitance-voltage (CV) characteristics after TPJ annealing. The hysteresis width shows maximum value when initial composition x =1.7, which shows the maximum photoluminescence (PL) intensity. The maximum hysteresis width of 6.8 V was observed with gate voltage swept between 20 and -20 V in x = 1.7 sample. The result means 7.4 x 1012 cm-2 carriers are injected to or emitted from Si nanocrystals. The duration of 1 V shift in flatband vo...

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Semiconductor nanocrystals smaller than the bulk exciton show substantial quantum confinement effects. Recent experiments including Stark effect, resonance Raman, valence band photoemission, and near edge X-ray adsorption will be used to put together a picture of the nanocrystal electronic states.

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Colloidal nanocrystals attract significant interest due to their potential applications in electronic, magnetic, and optical devices. Nanocrystal supercrystals (NCSCs) are particularly appealing for their well ordered structure and homogeneity. The interactions between organic ligands that passivate the inorganic nanocrystal cores critically influence their self-organization into supercrystals, By investigating the mechanical properties of supercrystals, we can directly characterize the particle-particle interactions in a well-defined geometry, and gain insight into both the self-assembly process and the potential applications of nanocrystal supercrystals. Here we report nanoindentation studies of well ordered lead-sulfide (Pbs) nanocrystal supercrystals. Their modulus and hardness were found to be similar to soft polymers at 1.7 GPa and 70 MPa respectively and the fractures ...

Science.gov (United States)

... A few applications, such as magnetic forming and levitation, have exploited the dynamic force pro- ducing capability of eddy currents. ...

International Nuclear Information System (INIS)

We present differential scanning calorimetry (DSC), X-ray diffractometry, in situ Moessbauer spectroscopy (MS), and transmission electron microscopy (TEM) studies in Metglas ribbons subjected to different heat treatments. The temperature evolution of the hyperfine field H_h_f(T) and the Curie temperature (T_c) of the amorphous phase are determined. The magnetic field originally present in the amorphous phase has a 'normal' behavior, in the sense that it can be described by the Weiss molecular field theory. The total angular momentum of the iron atoms turns out to be 5/2 and this implies Fe"3"+ in which the electronic spins are uncoupled. When the samples are maintained near T_c (#approx#673 K), three new magnetic phases are detected in the Moessbauer spectra, indicating an onset of a crystallization process well below the first crystallization temperature (T_X_1), as determined by DSC (#approx#820 K). The magnetic behavior of these phases is also described by universal Brillouin curves ...

Energy Technology Data Exchange (ETDEWEB)

Composite ZnO/Ag nanoparticles have been formed via the photocatalytic reduction of silver nitrate over the ZnO nanocrystals, their optical, electrophysical and photochemical properties have been investigated. Mie theory has been applied to analyze the structure of the absorption spectra of ZnO/Ag nanocomposite. The irradiation effects upon the optical properties of ZnO/Ag nanostructure have been investigated. It has been found that the irradiation of ZnO/Ag nanoparticles results in electrons accumulation by both the semiconductor and the metallic components of the nanocomposite. It has been found that silver nitrate can be photochemically deposited onto the surface of ZnO nanoparticles under the illumination with the visible light in the presence of the sensitizer - methylene blue. Kinetics of the sensitized Ag(I) photoredution has been studied. It has been concluded that the key stage of this process is the electron injection from ...

International Nuclear Information System (INIS)

Various examples of applications of these two techniques are described. A part of them are related to the analysis of adsorbed layers formed during gaz-metal interactions. The others are concerned with the analysis of passive films formed during dry and wet corrosion. Problems related to the calibration of these techniques are discussed.

British Library Electronic Table of Contents (United Kingdom)

Lithium phosphorous oxynitride(Lipon) thin films as a lithium ion conductive electrolyte were prepared by radio frequency reactive sputtering in N2 plasma. The properties of the amorphous Lipon solid electrolyte were investigated as a function of N2 pressure during reactive sputtering. The ionic conductivity and the electrochemical stability of Lipon thin films improved drastically as the N2 pressure decreased. The ionic conductivity closed to 10?6 S cm?1 and obtained a stability window of 1.0?5.0 V with an N2 pressure of 5 mTorr, where the number of nitrogen bonds between the phosphate groups were more than those formed at higher pressure. It was possible to fabricate the Li//LiCoO2 complete thin film battery using this Lipon solid electrolyte, which exhibited excellent discharge characte...

Science.gov (United States)

Elastically deforming thin glass (thickness = 0.13 to 0.80 mm) provides an alternate method of forming a curved glass reflector which can eliminate some of the disadvantages of thicker glass. A concept is described where silvered thin glass is bonded to a steel backing to form a laminate with a reflectance greater than 93%. Subsequent bending of the flat reflector laminate to a concentrating profile produces compressive stresses throughout the glass if the laminate is properly designed. These compressive stresses enhance fracture resistance and the lamination provides protection for the silver. The design of the laminate is outlined for 0.25 and 0.51 mm thickness glass and fabrication procedures are discussed. Thermal/humidity cycling, hail impact, bond strength measurements and reflectance results are presented which demonstrate the performance capabilities of this reflector laminate concept.

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Polymer electrolyte membrane fuel cells (PEMFCs) are energy conversion devices that produce electricity from a supply of fuel, such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter, we demonstrate that, instead of conventional noble metals, such as platinum, chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.

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We give a theoretical design for a locally resonant two-dimensional cylindrical structure involving a pair of C-shaped voids in an elastic medium which we term as double 'C' resonators (DCRs) and imbedded thin stiff bars, that displays the negative refraction effect in the low frequency regime. DCRs are responsible for a low frequency band gap which hybridizes with a tiny gap associated with the presence of the thin bars. Using an asymptotic analysis, typical working frequencies are given in closed form: DCRs behave as Helmholtz resonators modeled by masses connected to clamped walls by springs on either side, while thin bars behave as a periodic bi-atomic chain of masses connected by springs. The discrete models give an accurate description of the location and width of the stop band in the case of the DCR and the first two dispersion bands for the periodic thin ...

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A liquid-fillet is formed in front of a rotor blade in the cylinder of a horizontal agitated thin-film evaporator. Its thickness varies due to the gravity while the blade revolves inside the cylinder. In the critical condition, the amplitude of the oscillation becomes infinite and the phase advances 180 degrees. Prior to the critical condition, the experimental data agrees fairly well with the predictions. Near the critical condition, the amplitutde increases and the phase advances 60 degrees. In other words, the transition to the critical condition occurs continuously. (6 figs, 1 ref)

Energy Technology Data Exchange (ETDEWEB)

Nb{sub 2}O{sub 5} thin films were formed on aluminum foils by a sol-gel process in order to increase the capacitance of the aluminum foils which are used as aluminum electrolytic capacitors. Investigations focussed on the preparation and characterization of the coating solution, the formation of Nb{sub 2}O{sub 5} thin films on aluminum foils, and the heat treatment and anodization of the films. The phase transition and electrical properties, such as capacitance, leakage current, and withstand voltage of the Nb{sub 2}O{sub 5} thin films were also measured. The Nb{sub 2}O{sub 5} thin films annealed at temperatures below 550 degree C were found to be amorphous, but they were crystallized to the orthorhombic phase by annealing at temperatures higher than 580 degree C. The capacitance of the coated samples increased with an increase in the thickness of the formed ...

International Nuclear Information System (INIS)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of ...

Energy Technology Data Exchange (ETDEWEB)

The evolution of strain in the Pd-Si system during the growth of Pd{sub 2}Si thin films on Si (100) substrate has been followed in situ using a double optical beam technique. As was observed for the Pt-Si system, the reaction to form Pd{sub 2}Si yields a compressive intrinsic surface film stress as well as for the silicon-rich suicides as proposed by Angilello et al. [Thin Film Interfaces and Interactions, edited by J. Baglin and J. Poate (The Electrochemical Society, Pennington, NJ, 1980)]. A transmission electron microscopy analysis has revealed grain growth during the formation of Pd{sub 2}Si which cannot account for the compressive film stresses. The formation of silicide at the interfaces rather than the overall change in volume agrees with the sign of the stresses formed. 29 refs., 4 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

A thin film microoxidation test utilizing the concept of the Lubricant Stability Map has been used to study the effect of temperature on deposit formation by lubricants on upper piston locations of low heat rejection engines. The stability maps were established for two formulated lubricants in this study. These two lubricants were also evaluated in a series of engine tests with various piston temperatures. The deposition phenomena observed in the engine tests have been adequately simulated and described by the stability maps. It is concluded that lubricants at upper piston locations are under a thin film condition similar to that achieved by the thin film microoxidation test. The deposit formation trend is determined by the volatility, thermal stability, and oxidative stability of the base stock. Additives have little effect on deposit formation at very high temperatures. A combined consideration of all competing reaction ...

Energy Technology Data Exchange (ETDEWEB)

A lightweight, low permeability liner for graphite epoxy composite compressed gas storage vessels. The liner is composed of polymers that may or may not be coated with a thin layer of a low permeability material, such as silver, gold, or aluminum, deposited on a thin polymeric layer or substrate which is formed into a closed bladder using torispherical or near torispherical end caps, with or without bosses therein, about which a high strength to weight material, such as graphite epoxy composite shell, is formed to withstand the storage pressure forces. The polymeric substrate may be laminated on one or both sides with additional layers of polymeric film. The liner may be formed to a desired configuration using a dissolvable mandrel or by inflation techniques and the edges of the film seamed by heat sealing. The liner may be utilized in most any type of gas storage system, and is ...

Energy Technology Data Exchange (ETDEWEB)

In a slurry explosive, the fine droplets of the aqueous phase are dispersed in a continuous oily phase which comprises a thin film surrounding each droplet, the latter being less than one micron in size. The authors present these commercial explosives in three different forms, indicate their explosive properties and discuss their advantages from the safety viewpoint. They also report on tests undertaken with slurry explosives in quarries possessing different types of rock and using deep vertical shotholes.

International Nuclear Information System (INIS)

Dianionic tridentate, O, N, S Schiff bases derived from salicylaldehyde and 2-mercapto-amines react with Tc(V) gluconate to form radiochemically pure neutral Tc chelates. The existence of lipophilic Tc complexes could be proved by high voltage electrophoresis, thin layer chromatography and octanol/water partition coefficients. (author).

Energy Technology Data Exchange (ETDEWEB)

A) diffuse bilayer, B) spontaneously formed multilayer, and C) vertically homogenous thin films, are fabricated. The photocurrent/voltage performance is compared and it is found that the self-stratified structure (B) yields the highest energy conversion efficiency. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Science.gov (United States)

Magnetic particles have become very promising materials for drug delivery. However, preparation of magnetite particles with high surface area, biocompatibility, strong magnetic response, and suitable particle size still remains a major challenge. In this report, magnetite nanocrystal clusters with high surface areas were fabricated through a solvothermal process by introducing ammonium acetate as a porogen and trisodium citrate as a surface modification agent. The porosity, which was controlled by the reactant concentration, has been investigated in detail. The surface area of the nanocrystal clusters was as high as 141?m(2) g(-1) . Ibuprofen, as a model drug, was entrapped into the magnetite carriers. The interfacial interaction between the carboxylic groups on the drug molecules and the carboxylate groups on the carriers enhanced the loading efficiency. Low cytotoxicity in MCF-7 cell and in vitro constant drug release behavior combined with ...

International Nuclear Information System (INIS)

Low pressure silane plasmas are known for their ability to synthesize silicon nanoparticles via gas phase nucleation. While in the past this particle formation has often been considered from the viewpoint of a contamination problem in semiconductor processing, we here describe a silane low pressure plasma that enables the synthesis of highly oriented, cubic-shaped silicon nanocrystals with a rather monodisperse size distribution. These silicon nanocubes have successfully been used in the manufacture of single nanoparticle vertical transistors. We discuss the advantages of this new paradigm of building nanoelectronic devices. The plasma synthesis process is characterized in more detail than in prior work. The particle nucleation, growth and shape evolution are studied. Results indicate that the process provides two spatially distinct zones: a diffuse plasma for particle growth and a constricted plasma zone for particle annealing. Measurements of the plasma ion ...

International Nuclear Information System (INIS)

Continuous freestanding SiC(Al) films were fabricated by melt spinning the aluminum-containing polycarbosilane (A-PCS) precursor. The results showed that the films contained #beta#-SiC crystals, #alpha#-SiC nano-crystals, C clusters and small amount of Al_4O_4C and Al_4SiC_4. The Al atoms in the films played important roles as both sintering aids and grain growth inhibitor. The PL spectrum showed a wide luminescence band from 320 nm to 440 nm, and the origin of PL centered at 385 nm might be related to the #alpha#-SiC nano-crystals using quantum size effects. The obtained films are expected to have important applications in MEMS for the environment of high temperature and optoelectronic devices.

Science.gov (United States)

Nanosized particles are important because of their unique properties, different from the bulk, which leads to their enhanced catalytic, photocatalytic and electronic properties. This work has dealt with three different nanoparticle systems in the context of three different aspects of nanoparticle properties: (a) photocatalytis (TiO2/metal) system, (b) luminescence (CdSe) (c) alloying (Pt-Ag and Pd-Ag). The initial photocatalytic enhancement obtained by adding noble metal on semiconductor nanoparticles, degrades as fast as in 15 minutes and questions their long-term performance. XANES measurements on such irradiated systems like TiO2/Au, TiO2/Pt, TiO2/Ir indicates a positive oxidation state of these noble metals which renders them as recombination centers for photo-excited electrons and explains the decreased photocurrent. The oxidation is caused by holes. The EXAFS results also indicate a change of the interfacial structure under the effect of UV-irradiation, thus affecting the ...

CERN Document Server

Consider the flow of a thin layer of non-Newtonian fluid over a solid surface. I model the case of a viscosity that depends nonlinearly on the shear-rate; power law fluids are an important example, but the analysis here is for general nonlinear dependence. The modelling allows for large changes in film thickness provided the changes occur over a large enough lateral length scale. Modifying the surface boundary condition for tangential stress forms an accessible base for the analysis where flow with constant shear is a neutral critical mode, in addition to a mode representing conservation of fluid. Perturbatively removing the modification then constructs a model for the coupled dynamics of the fluid depth and the lateral momentum. For example, the results model the dynamics of gravity currents of non-Newtonian fluids even when the flow is not very slow.

Science.gov (United States)

Linearly polarized laser radiation accelerates electrons to very high velocities and these electron form a sheath layer on the rear side of thin targets where preferentially protons are accelerated. When mass-limited targets are used, the lateral transport of the absorbed laser energy is reduced and the accelerating field is enhanced. For targets consisting of two ion species, heavier ions facilitate formation of quasi-monoenergetic bunch of lighter ions. For circularly polarized light, fast electron production is suppressed by the absence of the oscillatory component of the ponderomotive force. Ions are accelerated on the front side by the separation field and very thin foil can be accelerated as one massive quasi-neutral block. As all ion species acquire the same velocity, this acceleration mechanism is preferred for heavier ions.

CERN Document Server

substrate). Within each group of simulations, three lubricant film thicknesses are studied to examine the effect of varying lubricant thickness. Statistical data are collected from each simulation and presented in this work. Via these data, together with the evolution, of atomic and molecular configurations, a very detailed picture of the properties of this thin film interface is presented. In particular, we conclude that perfluoropolyether lubricant forms distinct molecular layers when confined between two substrates, the rate of heat generation under shearing conditions typical of those in a head-disk interface is insufficient for thermal mechanisms to result directly in lubricant degradation, and mechanical stresses attained in the head-disk interface are unlikely to result in any significant degree of lubricant degradation. This thesis examines the tribology of a head-disk interface in an operating hard disk drive via non-equilibrium ...

International Nuclear Information System (INIS)

Concentration profiles of passive films formed on electrolytically anodized niobium and niobium-base alloys are obtained by Auger Electron Spectroscopy with simultaneous ion beam etching. The alloys investigated include 5Zr-Nb, 3Zr-10Ti-Nb, 2.5Zr-2W-Nb, and 1Zr-5Mo-5V-Nb. Experiments demonstrate that AES is among the most fascinating techniques for solving various characterization problems related to the structure and composition of the thin films formed by anodization. Data presented supports evidence that combined anodic and cathodic movements take place during film growth. 11 figures.

Energy Technology Data Exchange (ETDEWEB)

The advent of light metal alloys and advanced materials (polymer, composites, etc.) have brought the possibility of achieving important energy reductions into the full life cycle of these materials, especially in transportation applications. 1 These materials have gained acceptance in the aerospace industry but use of light metal alloys needs to gain wider acceptance in other commercial transportation areas. Among the main reasons for the relatively low use of these materials are the lack of manufacturability, insufficient mechanical properties, and increased material costs due to processing inefficiencies. Considering the enormous potential energy savings associated with the use of light metal alloys and advanced materials in transportation, there is a need to identify R&D opportunities in the fields of materials fabrication and forming aimed at developing materials with high specific mechanical properties combined with energy efficient processes and good ...

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The passive films formed on iron metal, alloys or stainless steel are extremely thin oxides or hydroxides and possess the properties of high chemical stability in the environment. These films show characteristics interested both electrical as well as electrochemical point of view due to the thin thickness of the films. Auger Electron Spectroscopy, X-ray Photoelectron spectroscopy and so on which are the conventional electrochemical measurement methods or the surface analysis methods are used for the analysis and evaluation of these films, however, at present, the application of research technique focusing the superconductor characteristics of the films are tried. Although, the potential modulation reflection spectroscopy method has merits like possibility of in-situ measurement, high precision, possibility of stable analysis even for extremely thin film and so forth, it has also demerits like difficulty ...

Energy Technology Data Exchange (ETDEWEB)

Three kinds of surface modifications were carried out on LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-films to improve the charge and discharge characteristics of LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} positive electrodes. Among them, Zr(OBu){sub 4}/poly(methyl methacrylate) (PMMA)-treated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrodes showed charge and discharge efficiency of 80-84% in the first cycle, which was much higher than that for an untreated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrode (73%). The values of the charge and discharge efficiency were still higher than that for an untreated electrode after the 30th cycle. The charge and discharge curves gave two plateaus at around 4.72 and 4.76 V, which were very similar to those for the untreated electrode. Ac impedance spectroscopy revealed that the surface film resistance should not increase by Zr(OBu){sub 4}/PMMA treatment. XPS measurements suggest that a ...

International Nuclear Information System (INIS)

Plasma-deposited thin films prepared at room temperature, ranging from 46 to 250 A of PdAu on #approx#45-50 A Si-oxide and Si-oxynitride films grown on Si wafers were studied. Grazing incidence X-ray diffraction, X-ray reflectivity, and XPS depth profile techniques were used to characterize the thin films. A reactive interface involving Pd- and Au-silicides is formed, linking the thin film to the Si-oxide and Si-oxynitride films: a small fraction of Pd and Au atoms from PdAu migrate into the Si substrate, first penetrating the oxide layer, and the small fraction of Si atoms from the oxide layer migrate into the PdAu film and form a silicide interlayer consisting of a reactive interface made up of mixtures of Au- and Pd-silicides interspersed within the matrix of PdAu and substrate. The concentration profiles of these silicides have a maximum at the interface with decay on both ...

Energy Technology Data Exchange (ETDEWEB)

Thin passive films formed on highly corrosion-resistant type-312L stainless steel, containing 20 mass% chromium and 6 mass% molybdenum, in 2 mol dm{sup -3} HCl solution at 293 K have been analyzed by glow discharge optical emission spectroscopy (GDOES). The stainless steel does not suffer pitting corrosion even in this aggressive solution, showing a wide passive potential region. The depth profiles obtained clearly show a two-layer structure of the air-formed and passive films: an outer iron-rich layer and an inner layer highly enriched in chromium. Alloy-constituting molybdenum is deficient in the inner layer of the passive films and is enriched in the outer layer, particularly at the active dissolution potential. The molybdenum species in the outer layer may retard the active dissolution of stainless steel, promoting the formation of stable passive films highly enriched in chromium. Chloride ions are present only at the ...

British Library Electronic Table of Contents (United Kingdom)

In the present study, electrically conducting carbon nanofiber (CNF) mats were produced by incorporating tetraethoxy orthosilicate (TEOS) into polyacrylonitrile (PAN) via electrospinning. A simple thermal treatment was applied to the electrospun nanofibers to create ultramicropores that could accommodate a large number of ions were formed on the surface of the CNFs, removing the need for a time-consuming activation step. The Si/CNF composites showed high capacitance and energy/power density values due to the formation of ultramicropores and the introduction of heteroatoms.

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Many organic compounds can be adsorbed onto the interface of a metal and solution to form a thin film that inhibits the corrosion process according to a blocking and/or negative catalytic effect. Using the Langmuir-Blodgett (LB) technique, stearic acid (SA) monolayers were deposited onto the surface of an iron (Fe) electrode to study the inhibition effect and the mechanism of SA in a neutral medium. Molecular orientation and the number of deposited monolayers of SA were shown to have marked effects on inhibition of Fe corrosion. The inhibition mechanism depended mainly on blocking.

International Nuclear Information System (INIS)

The mechanistic aspects of electrochemical reductions of U"V"IO_2(acac)_2dmso(acac=acetylacetonate, dmso=dimethyl sulfoxide) complex with bidentate ligand(acac) in DMSO were investigated by using cyclic voltammetry, normal pulse voltammetry, and spectrophotometer equipped with an optical transparent thin layer electrode cell. It is concluded that the uranyl complexes with bidentate ligands at the equatorial plane form stable U(V) complexes by the electrochemical reduction and that their molar extinction coefficients in the visible region are very small. (J.P.N.).

International Nuclear Information System (INIS)

Evolution of the passive films formed on AISI 304L and duplex stainless steel SAF 2205 in NaOH 0.1 M was investigated using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). Special attention is paid to the effect of Mo in the generation of the films. Results point out to the stabilising effect of the molybdates on the surface of the film, enhancing the formation of a thin layer on the SAF 2205 with a higher Cr/Fe ratio.

International Nuclear Information System (INIS)

In the early 1980s, AECL built a Waste Treatment Centre (WTC) for managing low-level solid and aqueous liquid wastes for converting CANDU wastes. At present, two liquid waste streams are being treated at the WTC. The liquid waste streams are volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis (TRO) membrane technologies. The concentrate produced from the TRO system and the volume-reduced MF backwash solutions are evaporated while simultaneously adding bitumen in a thin-film evaporator. A water-free product of chemical and radiochemical salts and bitumen is removed in 200-L galvanized steel drums for storage. The radiation field of product drums on contact typically has a value of 0.5 to 3 R/h depending upon the feed concentration of radioactivity to the evaporator. The total solids content in the 200-L drum ranges from 25 to 35%. Encapsulated in the bitumen matrix are a ...

International Nuclear Information System (INIS)

By using megaelectronvolt "4He ion backscattering techniques and transmission electron microscopy, the authors have investigated the interactions of ion beams with thin film structures in a number of silicide-forming systems. The mixed layer was found to be an equilibrium compound for near-noble metals and an amorphous phase for refractory metals. Differences in behavior have also been observed in near-noble metal systems. For palladium, the Pd_2Si phase grew with ion dose and remained crystalline up to high dose. For nickel, the compound Ni_2Si was formed initially and became amorphous on prolonged irradiation. All the results indicate the significance of atomic mobility at target temperatures in determining the phase formation and in explaining the sensitivity of the silicides to ion bombardment. (Auth.).

International Nuclear Information System (INIS)

Thin Pt, Pd, Pt_2Si, PtSi, Pd_2Si, Ni, Mo, W, Nb, Ti, V films deposited on Si single crystal were treated by using electron beam pulses of 60 ns duration in the 0.4-4 J/cm"2 energy density range. Irradiation of these structures produces at the same time many phases. Post-thermal annealing of the reacted layer induces the formation of a stable phase, the same obtained by only thermal treatment in a conventional furnace. A linear relationship between the energy density range and the lowest eutectic temperature of the compounds formed has been found. Further SEM observations seem to identify a liquid layer from which the phases are forming by subsequent fast cooling. (author).

CERN Document Server

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their ...

Energy Technology Data Exchange (ETDEWEB)

The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from ...

Science.gov (United States)

PMID:19862292

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

Ultraviolet (UV) upconversion (UC) luminescence in Yb3+/Er3+-codoped yttrium oxide (Y2O3) nanocrystals can be enhanced by orders of magnitude via tridoping further with Li+ ions under diode laser excitation of 970 nm. Sensitized three-photon UC radiations at 390 and 409 nm, corresponding to the 4G11/2?4I15/2 and 4H9/2?4I15/2 of Er3+ ions, respectively, present an enhancement time of about 33 times, which is larger than the 24 times enhancement for the UC green radiation. The UV UC radiation at 320 nm that corresponds to the 2P3/2?4I15/2 of Er3+ ions has also been greatly enhanced. Theoretical calculations interpret that all the observed enhancement times of UV UC radiations arise from the prolonged lifetimes of their intermediate states.

Science.gov (United States)

... Abstract : MANY THIN FILM ACOUSTO-OPTIC INTERACTION EXPERIMENTS FOR ... CONVERTERS, AND FOR FAST SWITCHES HAVE BEEN ...

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This paper introduces recent instances of polymerizers for highly viscous liquid needed in the field of synthetic resin and synthetic fiber. A horizontal twin-shaft type polymerizer has two horizontally rotating shafts with stirring blades of spectacle-shaped type, which are arranged at a 90 [degree] phase difference. As they rotate, they scrape highly viscous liquid sticking to the surface inside the polymerizer and on the rotating shafts. This polymerizer is capable of processing highly viscous liquid up to about 2000 Pa[center dot]s. A lattice-type twisting blade polymerizer is a vertical-type reactor and features a special stirring blade capable of stirring highly viscous liquid up to 5000 Pa[center dot]s This polymerizer has no central rotating shaft so that highly viscous liquid does not stick on it. A sloped blade-type thin-film evaporator has spiral blades in the longitudinal direction of the rotor. Process liquid pushed to the inner wall of the vessel by ...

CERN Document Server

In order to perform a detailed study of the stellar kinematics in the vertical axis of bars, we obtained high signal-to-noise spectra along the major and minor axes of the bars in a sample of 14 face-on galaxies, and used them to determine the line of sight stellar velocity distribution, parameterized as Gauss-Hermite series. With these data, we developed a diagnostic tool that allows one to distinguish between recently formed and evolved bars, as well as estimate their ages, assuming that bars form in vertically thin disks, recognizable by low values for the vertical velocity dispersion sigma_z. Through N-body realizations of bar unstable disk galaxies we could also check the time scales involved in the processes which give bars an important vertical structure. We show that sigma_z in evolved bars is roughly around 100 Km/s, which translates to a height scale of about 1.4 Kpc, giving support to scenarios in which bulges ...

Energy Technology Data Exchange (ETDEWEB)

Feasibility of mushy state forming of magnesium alloys making use of resistance heating was examined. Magnesium alloys, AZ31, AZ61 and AZ91, were taken up as experimental materials and cylindrical billets with a diameter of 15 mm and a height of 20 mm were used for both resistance heating and forming experiments. Input heat control was applied to the billet heating and insertion of thin discs of austenitic stainless steel with a low thermal conductivity between the billet and copper electrodes was attempted in order to improve the efficiency of the billet heating. Results were summarized as follows. (1) Resistance heating by input heat control was successful to heat the billets to their respective mushy state. (2) Insertion of the discs was very helpful in heating the billets and realized the heating in a couple of seconds. (3) The force applied to the electrodes to ensure the electrical contacts being too small, sparks ...

International Nuclear Information System (INIS)

Radioactive "3"1Si was used as a marker to study metal silicide formation. Activity profiles in the silicides were measured by a combination of ion beam sputtering, radioactivity counting and Rutherford backscattering of charged nuclear particles. It was found that the metal is the diffusing species during Co_2Si, Pt_2Si, NiSi and PtSi formation, while silicon diffuses during CrSi_2, TiSi_2 and ZrSi_2 formation. Silicon was also found to be the diffusing species during second phase formation of CoSi from Co_2Si. However, in this case it was established that the silicon diffuses by a grain boundary and/or interstitial mechanism. Both the metal and silicon diffuse during Ni_2Si and Pd_2Si formation. In an attempt to interpret complex radioactivity profiles a computer program, simulating various diffusion mechanisms during both first and second phase silicide formation, was written. A numerical approach was used whereby silicide growth occurs in small increments and the concentration of ...

British Library Electronic Table of Contents (United Kingdom)

Between 1986 and 1990 the eruptive activity of Erebus volcano was monitored by a video camera with on-screen time code and recorded on video tape. Corresponding seismic and acoustic signals were recorded from a network of 6 geophones and 2 infrasonic microphones. Two hundred Strombolian explosions and three lava flows which were erupted from 7 vents were captured on video. In December 1986 the Strombolian eruptions ejected bombs and ash. In November 1987 large bubble-bursting Strombolian eruptions were observed. The bubbles burst when the bubble walls thinned to ?20?cm. Explosions with bomb flight-times up to 14.5?s were accompanied by seismic signals with our local size estimate, ?unified magnitudes?? (mu), up to 2.3. Explosions in pools of lava formed by flows in the Inner Crater were co...

British Library Electronic Table of Contents (United Kingdom)

Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80?keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted d...

British Library Electronic Table of Contents (United Kingdom)

Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, South China Sea, consists of an annular reef rim surrounding a central lagoon. On the atoll rim there are either protuberant ?motu? (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encrustation, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2) on massive colonies of Galaxea fascicularis, (3) on dead Montipor...

International Nuclear Information System (INIS)

Purpose: To enable the solidification of liquid waste containing radioactive substance in a free shape with large volume reduction ratio without a pulverizing step by producing solute in the liquid waste as a slurry in a predetermined organic solvent and forming it into a cake by mechanical exfoliation. Method: Liquid waste containing suitably concentrated radioactive substances is supplied to a centrifugal thin film evaporator together with an organic agent having a higher boiling point than water and a non aqueous solution to evaporate the water content, the solute in the waste is produced as a slurry in the organic solvent, and removed as cake-state solute slightly residued with the organic solvent by the mechanical exfoliation such as centrifugal exfoliation or settling exfoliation from the slurry-state liquid. Accordingly, it can be increased in size as compared with the powder reduced in volume of the radioactive liquid waste, and can be ...

British Library Electronic Table of Contents (United Kingdom)

Asphalt emulsions were evaluated as a means to immobilize radiological contaminants deposited on urban surfaces after a dirty bomb attack. Contaminated surfaces would be sprayed with thin coatings of asphalt emulsion to encapsulate the radioactive particles until the site can be safely remediated. This research investigated applications of an asphalt emulsion (Topein C, Encapco Technologies, LLC, Napa, CA) to treat (zero-valent) iron, lead, and uranium powders on various building material surfaces. Initial studies found that some of the building materials (limestone, concrete, and metal) reacted with the emulsion producing gas bubbles, which formed 0.001 to 1 cm vesicles in the cured asphalt emulsion. These vesicles, however, did not expose the building material surface, and the reaction a...

British Library Electronic Table of Contents (United Kingdom)

This paper deals with surface defects of automobile outer panels, which alter significantly the vehicle quality. Such defects occur during springback, after forming or flanging steps, and are characterized by concave depression of small amplitude over the convex shape of the part. The aim of this work is to reproduce at the laboratory scale a surface defect that occurs after flanging on a geometry similar to a door upper corner. A dedicated device has been designed in order to generate small size surface defects during flanging of metallic thin sheets. The outer surface of the sample was digitalized and the spatial geometry of the defect was evaluated from curvature change along 2D profiles. This study shows that the flanging height does not influence significantly the surface defect geome...

International Nuclear Information System (INIS)

A one-nanometer scale transmission electron microscope electron probe X-ray microanalysis characterization of as-deposited and annealed aluminum--11.5 at.% zirconium multilayer samples in cross-section synthesized by magnetron sputtering is reported on here. Composition line profiles were acquired across Zr layers in as-deposited material and samples isochronally annealed in a differential scanning calorimeter to temperatures of 290 C and 485 C. A spatial resolution of approximately 1.5 to 2.0 nm was achieved in these experiments and will be improved by deconvolution of the instrumental electron probe function from the data. The as-deposited structure consisted of crystalline Al and Zr layers with thin amorphous layers at the Al/Zr interfaces. The amorphous interface layers increased in thickness upon annealing to 290 C. Additionally, at 290 C a metastable cubic alloy forms at the Zr deposited on Al interface. Upon heating to 485 C a multilayer ...

Energy Technology Data Exchange (ETDEWEB)

The molar of guinea pigs was irradiated with /sup 60/Co-..gamma.. ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No uniform relation was obtained between the histological staining of the organic stroma of ...

Science.gov (United States)

A facile solution chemistry is demonstrated to fabricate high-quality polycrystalline strontium ruthenium oxide (SrRuO{sub 3}) thin film electrodes on silicon substrates suppressing the formation of undesired ruthenium oxide (RuO{sub 2}) for the deposition of dielectric and ferroelectric materials like lead lanthanum zirconate titanate (PLZT). The robust, highly crystalline SrRuO{sub 3} film fabrication process does not favor the formation of RuO{sub 2} because of molecular level modification of the precursors possessing analogous melting points, yielding homogeneous films. This chemistry is further understood and complemented by kinetic and thermodynamic analysis of the DTA data under nonisothermal conditions, with which the activation energies to form RuO{sub 2} and SrRuO{sub 3} were calculated to be 156 {+-} 17 and 96 {+-} 10 kJ/mol, respectively. The room-temperature resistivity of the SrRuO{sub 3} film was measured to be 850 {+-} 50 ...

Energy Technology Data Exchange (ETDEWEB)

Surface layers on lithium electrodes formed in several solvents including dimethyl carbonate (DMC), diethyl carbonate (DEC), polyethylene glycol 400 dimethyl ether (PEG400DME), and propylene carbonate (PC) have been studied by Raman spectroscopy. Both DMC and DEC were used singly, and also mixed with either methyl acetate or methyl formate. The Raman spectra showed that passive films formed on the Li surface in different solvents may have different chemical structures, which changed during the charging and discharging processes. A solid film of fullerene C6O, which could be used as a cathode in Li rechargeable batteries, was examined in the PEG400DME solution by both electrochemical and Raman spectroscopy. Cyclic voltammograms (CVs) showed five redox peaks which suggested the formation of C6O(-), C6O(2-), C6O(3-), C6O(4-), and C6O(5-). Raman spectra obtained from thin C6O film indicated that the thin ...

Science.gov (United States)

... After strip- ping off the chloroform, the dibromo ethyl (EDBEB) compounds are separated from the m-BDBEB using a thin film evaporator. ...

Science.gov (United States)

Sputtering of glass coatings on cadmium sulfide thin film solar cells

British Library Electronic Table of Contents (United Kingdom)

The TiO2 hollow microspheres were prepared by microwave-assisted solvothermal treatment without template. The morphology and the phase of TiO2 hollow microspheres were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and BET surface areas. The results show that the particles have hollow structures and the shell was covered by nanocrystals and have higher specific surface area. The possible formation mechanism of hollow TiO2 spherical structures has simply been proposed. The activity was evaluated by the photocatalytic degradation of methyl orange (MO). The results show that the particles having specific surface area show higher photocatalytic activity. It can be attribute to the doped ...

Scientific Electronic Library Online (English)

Abstract in english Structural characterisations using the SAXS technique in a number of nanoheterogeneous materials and liquid solutions are reviewed. The studied systems are protein (lysozyme)/water solutions, colloidal ZnO particles/water sols, nanoporous NiO-based xerogels, hybrid organic-inorganic siloxane-PEG and PPG nanocomposites and PbTe semiconductor nanocrystals embedded in a glass matrix. These investigations also focus on the transformations of time-varying structures and on str (more) uctural changes related to variations in temperature and composition. The reviewed investigations aim at explaining the unusual and often interesting properties of nanostructured materials and solutions. Most of the reported studies were carried out using the SAXS beamline at the National Synchrotron Light Laboratory (LNLS), Campinas, Brazil.

International Nuclear Information System (INIS)

Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. (author)

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

... AT THE INTERFACE, A THIN OXIDE LAYER IS OBSERVED ALONG WITH POSSIBLE PALLADIUM SILICIDES. PALLADIUM ...

Energy Technology Data Exchange (ETDEWEB)

Among the most promising technological alternatives for the development of photovoltaic modules and cells of a low cost, good energetic conversion and feasibility for mass production, polycrystalline silicon thin film solar cells deposited directly on a transparent substrate are currently being considered the best. We have developed in our laboratory a PECVD reactor capable of producing the deposition of amorphous hydrogenated silicon at rates of above 2 nm/seg, allowing a significant production per line on the plant. Discharge gas is silane, to which diborane or phosphine is added so as to form the cell. Basically, work is done on a structure of cell type TCO/n+/p-/p+/M, which has 2 {mu}m of total thickness. Schott AF-37 glass is used as a substrate, for their ability to withstand temperatures of up to 800 C. The amorphous cell is subsequently annealed at gradual temperatures of 100 C to achieve dehydrogenation up to 650-700 C for 12 h until ...

International Nuclear Information System (INIS)

Microstructure and electrical properties of iron oxide Fe_2O_3 thin films prepared by spray pyrolysis method have been experimentally characterized. The effect of substrate temperature as well as deposition time on the structural features (crystallite size and microstrain) and electric resistivity of these films has been investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) characterized the structure study. The results of X-ray diffraction showed that with increasing substrate temperature bias the film structure changed from amorphous to crystalline at the same deposition time. At a substrate temperature of 350 deg. C and low deposition time, #alpha#-Fe_2O_3 appears almost in amorphous form. With rising the substrate temperature and deposition time, the crystallinity was improved. At T_s_u_b>350 deg. C, a well-crystallized rhombohedral phase of #alpha#-Fe_2O_3 was obtained. Single order Voigt profile method has been ...

Energy Technology Data Exchange (ETDEWEB)

The possibilities to electrodeposit thick coatings composed of nanoparticles of Sb and Sb{sub 2}O{sub 3} for use as high-capacity anode materials in Li-ion batteries have been investigated. It is demonstrated that the stability of the coatings depends on their Sb{sub 2}O{sub 3} concentrations as well as microstructure. The electrodeposition reactions in electrolytes with different pH and buffer capacities were studied using chronopotentiometry and electrochemical quartz crystal microbalance measurements. The obtained deposits, which were characterised with XRD and SEM, were also tested as anode materials in Li-ion batteries. The influence of the pH and buffer capacity of the deposition solution on the composition and particle size of the deposits were studied and it is concluded that depositions from a poorly buffered solution of antimony-tartrate give rise to good anode materials due to the inclusion of precipitated Sb{sub 2}O{sub 3} nanoparticles in the Sb coatings. Depositions under ...

Energy Technology Data Exchange (ETDEWEB)

The Ordos Basin of north-central China is well known for vast energy resources. This nonmarine interior basin developed on the North China-Korean platform following the Late Triassic Indochina orogeny and, for a time, contained a large freshwater lake prior to being uplifted into its present form at the close of the Mesozoic. Lower to Middle Jurassic coal occurs in the fluviolacustrine Yan'an Formation along the southern margin of the basin in the Huanglong coalfield. In the northeast part of the field, the formation ranges from 0 to 180 m in thickness and is divided into five fining-upward members, each representing a regressive-transgressive lacustrine cycle. Low-sulfur, high-volatile bituminous coal is complexly distributed in the lowest member of the Yan'an Formation. Deposition of this member was influenced by two tectonic events that controlled coal occurrence. First, regional uplifts were produced by the Late Triassic Indochina orogeny and ...

International Nuclear Information System (INIS)

This paper reports the results of a fine-probe EDS microanalytical study of cellular precipitation in a Cu-Ti binary alloy. Compositional profiles across the solute depleted Cu-rich FCC lamellae and the Cu_4Ti lamellae within isothermally formed cellular colonies were measured in a FEG-TEM from thin-foil specimens prepared by conventional electropolishing and by a technique using a Ga"+ focused ion-beam (FIB). The Cliff-Lorimer ratio method, with an absorption correction, was employed to quantify the compositions. Two FIB samples were prepared with different orientations of the lamellae with respect to the ion-milling direction. The compositional profiles across the Cu-rich FCC lamellae and the Cu_4Ti compound lamellae in both the FIB-prepared samples and the electropolished sample were, within experimental error, numerically equivalent. The composition of the Cu_4Ti compound phase lamellae was very close to the ideal stoichiometric composition ...

Energy Technology Data Exchange (ETDEWEB)

Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na/sub 2/SO/sub 4/ at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250/sup 0/C after fully reductive treatment of the specimen. In air-saturated solution, the peak of active dissolution is not observed. ...

Energy Technology Data Exchange (ETDEWEB)

Technology is being developed for preparing functional materials by synthesizing new functional peptides in which non-natural amino acid needed for the functional manifestation is introduced, and by modifying the surface of a base plate such as silica glass by using such peptides. Activities were conducted in the three areas of (1) creation of functional molecules, (2) materialization technology, and (3) comprehensive investigation and research; the activities were carried out independently and parallelly in the first two areas. In (1), design technique for the structures and functions of peptides was developed, as were conformational control technique, synthesis of peptides having optical/electronic functions, peptide synthesis by an enzyme method, and R and D on introduction of non-natural amino acid into peptides; in (2), element technologies were developed such as substrate forming technique (pattern forming and thin ...

International Nuclear Information System (INIS)

The formation and properties of Pd_2Si formed by focused ion beam implantation of Pd ions into Si is presented in this thesis. An extensive microstructural study using transmission electron microscopy was undertaken and the as-implanted as well as annealed microstructure is shown. Results of other analysis techniques such as Rutherford back scattering and secondary ion mass spectrometry etc. are also presented. Kinetic information on the growth of Pd_2Si obtained by both microstructural and resistance measurements indicates that the activation energy for growth of the silicide is around 0.36 to 0.39 eV. This can be compared with the normally reported value of 1.5 eV for Pd_2Si formed by annealing thin film Pd on Si. The growth of the silicide was found to follow t"1"/"2 kinetics. Microstructural observation of the as-implanted samples showed extensive in-situ formation of Pd_2Di and also surprisingly few defect structures. ...

International Nuclear Information System (INIS)

In the convolution/superposition method of photon beam dose calculations, inhomogeneities are usually handled by using some form of scaling involving the relative electron densities of the inhomogeneities. In this paper the accuracy of density scaling as applied to primary electrons generated in photon interactions is examined. Monte Carlo calculations are compared with density scaling calculations for air and cork slab inhomogeneities. For individual primary photon kernels as well as for photon interactions restricted to a thin layer, the results can differ significantly, by up to 50%, between the two calculations. However, for realistic photon beams where interactions occur throughout the whole irradiated volume, the discrepancies are much less severe. The discrepancies for the kernel calculation are attributed to the scattering characteristics of the electrons and the consequent oversimplified modeling used in the density scaling method. A ...

Energy Technology Data Exchange (ETDEWEB)

In situ fracture studies on thin-film NiTi intermetallic compounds have been carried out in the high-voltage electron microscope at Argonne National Laboratory. Local stress-induced amorphization of regions directly in front of moving crack tips has been observed under tensile loading conditions. The stress-induced amorphization at crack tips exhibits a temperature dependence similar to that of ion-induced amorphization of NiTi. The upper limiting temperature for stress-induced amorphization is the same as that for ion-induced amorphization of crystalline NiTi and for amorphous phase formation during ion-beam mixing of Ni and Ti multilayer specimens. This upper limiting temperature of 600K is also the lowest temperature at which stress-induced amorphous phase crystallizes during isothermal annealing. This isothermal crystallization temperature is nearly 200K less than the kinetic crystallization temperature during heating of unrelaxed NiTi glasses ...

British Library Electronic Table of Contents (United Kingdom)

The nanostructure Ni-doped CdO films have been prepared by sol gel spin coating method. Atomic force microscopy results indicate that the CdO films are formed from the nanoparticles and the grain size is changed with nickel content. X-ray diffraction patterns of the films indicate that the undoped and Ni-doped CdO films have polycrystalline structure with a cubic sodium chloride structure, showing two main characteristic peaks assigned to the (111) and (200) planes. The optical band gap values of undoped and Ni-doped CdO films were determined by optical absorption method. The Eg values of the CdO films were found to be in the range of 2.26?2.60?eV. The Eg values of the CdO films increase with the content of Ni dopant (up to 6% Ni). It is evaluated that the optical band gap and grain size o...

British Library Electronic Table of Contents (United Kingdom)

Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2x the...

Energy Technology Data Exchange (ETDEWEB)

The present invention concerns a negative ion source electrode which can be preferably used in a neutral particle injection device using negative ions for a thermonuclear reactor. Negative ion beams are deflected to the direction opposite to the deflecting direction by magnetic fields by using an electron suppression electrode having electrode holes with the position previously displaced before negative ion beams are accelerated to have a high energy by an accelerator thereby correcting the orbit of the negative ion beams easily. In addition, since the deflection correction electrode having the electrode holes is disposed, a proper voltage is applied to the deflection correction electrode to correct the orbit of the negative ion beams conveniently. Since the deflection correction electrode has a simple structure of a thin flat plate having electrode holes, the orbit of negative ion beams can be corrected efficiently by an extremely simple structure without inducing ...

International Nuclear Information System (INIS)

The manufacture and use of wood/plastic composite (WPC) as an example of wood matrix and wood sawdust/plastic composites (SDP) as an example of plastic matrix are reviewed. The raw material for WPC are mostly vinyl monomers, particularly methyl methacrylate and styrene. The reaction in WPC polymerization is radical polymerization. Researches on the radiation sources mostly resulted in gamma-ray. Electron beam can be applied only to thin products. The future use of WPC may be for furnitures, sporting goods, decorative parts and the like. Vital study on the reduction of manufacturing costs is required, for example, the improvement of reaction and the adoption of continuous process must be considered. The raw materials for SDP are wood sawdust, vinyl monomer (mostly methyl methacrylate) and resins. Electron beam accelerators are the most preferable radiation source because of its high efficiency and safe operation. SDP shows good forming property. ...

Energy Technology Data Exchange (ETDEWEB)

Magnetic imaging in the transmission electron microscope (TEM) has been used to examine submicron elements with the aim of discovering down to what element size complex domain patterns can form. The elements were squares, circles, triangles, and pentagons in the size range 100{endash}500 nm and were made from 36 nm Co films or 8 nm Ni{sub 80}Fe{sub 20} (NiFe) with in-plane magnetization. The magnetic domain structures in these elements were imaged at high resolution using the differential phase contrast imaging mode in a TEM. Nonuniform magnetization structures were seen in the images. Vortices were present at remanence in all shapes of 36-nm-thick Co elements down to 100 nm size and in circular NiFe elements down to 116 nm diameter. Triangular NiFe elements did not have a vortex state at remanence, instead the magnetization curved round within the element but did not achieve complete flux closure. In simulations of square and circular NiFe elements, it was found ...

Energy Technology Data Exchange (ETDEWEB)

An updated review of the state of the art in the development of GaAs solar cells is provided, with emphasis on AlGaAs-GaAs cells suitable for space applications. A set of theoretically derived characteristics is given for this type of solar cell. Comparison of measured performance with theory shows excellent agreement. Data on the effects of radiation damage (high-energy electrons, protons, and neutrons) is also integrated into a form useful for evaluation purposes. Techniques for fabricating (AlGa)As-GaAs solar cells in quantities large enough for practical applications are discussed and are shown to have been demonstrated. The possibility of extending these techniques to the fabrication of very thin low-weight cells for space applications is also considered. Finally, the results obtained to date in the development of GaAs solar cells for applications requiring concentrated sunlight are reviewed, for terrestrial as well as for space ...

Energy Technology Data Exchange (ETDEWEB)

Alkaline fuel cells (AFCs) provide a less corrosive environment and can provide higher electrode reaction kinetics than proton exchange membrane fuel cells (PEMFCs). The alkaline media also allows for the replacement of platinum (Pt) based electrocatalysts with non-Pt electrocatalysts. Studies have shown that palladium (Pd) and silver (Ag) form a homogenous solid solution with a face-centred cubic structure within a large range of temperatures. This study described the results of an oxygen reduction reaction (ORR) on lead-silver (Pd-Ag) alloy electrodes in alkaline media. The reaction was compared with Pd and Ag electrodes. The alloys were synthesized as thin films using a sequential electroless deposition of Pd and Ag on stainless steel discs followed by an annealing procedure in an Ar stream. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize catalyst structure, ...

International Nuclear Information System (INIS)

In this work, the effects of substrate temperature that was changed from 100 to 500 "oC on the structural, chemical and electrical properties of carbon films, prepared by direct current magnetron sputtering technique, on 316L stainless steel as bipolar plate had been investigated. Raman spectroscopy and scanning electron microscopy (SEM) were performed to study the structure and the morphology of the deposited films, respectively. The corrosion resistance and the electrical resistivity were carried out by using corrosion tests and four point-probe technique. The results show that the carbon films change the structure from amorphous to graphite-like by increasing temperatures. At the temperatures higher than 300 "oC, the holes and porosities are formed on the film indicating a decrease of film quality. According to our results, corrosion resistance and electrical properties are depended strongly on the substrate temperature.

DEFF Research Database (Denmark)

Polyacrylonitrile (PAN)-based polymer electrolytes have obtained considerable attention due to their fascinating characteristics such as appreciable ionic conductivity at ambient temperatures and mechanical stability. This study is based on the system PAN-ethylene carbonate (EC)-propylene carbonate (PC)-lithium trifluoromethanesulfonate (LiCF3SO3). The composition 15 mol% PAN-42 mol% EC-36 mol% PC-7 mol% LiCF3SO3 has shown a maximum room temperature conductivity of 1.2 x 10(-3) stop S cm(-1) stop. Also, it was possible to make a thin, transparent film out of that composition. Cells of the form, Li/PAN-EC-PC-LiCF3SO3/polypyrrole (PPy)-alkylsulfonate (AS) were investigated using cyclic voltammetry and continuous charge-discharge tests. When cycled at low scan rates, a higher capacity could be obtained and well-defined peaks were present. The appearance of peaks elucidates the fact that redox reactions occur completely. This well proves the reason ...

Science.gov (United States)

... Casting Explosive forming Forging Electrohydraulic forming Extruding Magnetic forming Rolling Electroforming Drawing Powdered metal forming ...

British Library Electronic Table of Contents (United Kingdom)

Thinning and burning forests established on revegetated mine pits in jarrah (Eucalyptus marginata) forests of south-west Australia is being considered as a management option to accelerate succession in sites with excessive tree densities. To assess the impact of thinning and burning on reptiles and small mammals, we installed trapping grids in eight thinned and burned sites, each paired with untreated controls. Of the eight pairs, four were in rehabilitated sites (planted with nonlocal species) and four were in restored sites (seeded with local species). Thinning and burning had no significant impact on the small mammal community, although Cercatetus concinnus was more abundant in rehabilitated sites. In contrast, thinning and burning significantly increased reptile abundance and species r...

Science.gov (United States)

Thin film solar cells and solar cell testing - photovoltaic cells, radiation damage to cadmium sulfide solar cells, and airplane testing of solar cells

Science.gov (United States)

A thin-film evaporator requires only a short heating time to concentrate a solution since it has a high thermal efficiency and has a small capacity. Thus, the chemical industry often uses this type of evaporator for concentrating materials that are subjec...

Science.gov (United States)

... Accession Number : ADA539462. Title : 6.5 kW, Yb:YAG Ceramic Thin Disk Laser. Descriptive Note : Technical note 1 Jan-1 Dec 2010. ...

Energy Technology Data Exchange (ETDEWEB)

Tidally dominated sections from the Middle Jurassic Beryl Formation of the Beryl Field, Viking Graben (UKCS) were deposited during rapid changes in relative sea level. High density well coverage in this key producing interval has allowed the construction of an integrated high resolution sequence stratigraphic scheme based on sedimentological, ichnofaunal, wireline, biostratigraphic and engineering data. From this database a number of high resolution sequences in the Bajocian-Bathonian Beryl Formation have been identified composed of interbedded sandstones, siltstones and mudstones. These sediments formed tidally-influenced deltas and estuaries deposited in actively subsiding half-grabens during regionally extensive base-level changes. For reservoir management purposes, the formation has been split into 5 units. The thickest interval, Unit 3, is considered here. In the northern part of the Beryl Field, Unit 3 is bounded above and below by regionally extensive, ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this work was to investigate the optical properties of several high T/sub c/ compounds in the form of sputtered films. The measurements are used toward this end: optical absorptance (using a calorimetric technique near 4.2K), which yields (after Kramers-Kronig analysis) the complex dielectric function, and thermoreflectance (which measures the change in reflectance in the optical range when a 1 to 10/sup 0/K temperature wave is applied), performed at two ambient temperatures (80 and 300/sup 0/K), yielding the differential dielectric function. The sputtered films included Nb/sub 3/Ge, Nb/sub 3/Al, V/sub 3/Ga and Nb/sub 3/Ir. It is noted that Nb/sub 3/Ir is not a high T/sub c/ superconductor. The thermoreflectance on the bulk samples V/sub 3/Si, V/sub 3/Ge and single crystal Cr/sub 3/Si were not performed because the samples were not in the form of thin films. The thermomodulation studies are correlated with ...

Energy Technology Data Exchange (ETDEWEB)

In an extended case report, we discuss four cases with masses in the lacrimal fossa representing the most important entities in this region (lymphoma, pleomorphadenoma, inflammatory pseudotumor, and malignant epithelial tumor). The different indications for CT and MRI are explained. For the differential diagnosis of lacrimal gland lesions, the following imaging parameters are important: The shape of the lacrimal gland, the inner structure, the degree of contrast enhancement, and the surrounding bony structures. In the evaluation of the expansion of lacrimal gland lesions, CT in thin slices with multiplanar reconstructions is equal to MRI. However, the contrast-enhancement of lacrimal glands is better evaluated with MRI than with CT. The bony structures are better visualized on CT than on MRI. (orig.) [Deutsch] In einem erweiterten Fallbericht wird ueber die vier grossen Entitaeten bei Traenendruesenraumforderungen berichtet (Lymphom, pleomorphes Adenom, ...

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Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium beneath the passive film. ...

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The Sunniland Limestone (Lower Cretaceous), consisting of carbonate rock and anhydrite, bears the only oil and gas production in southern Florida. Raccoon Point field, Collier County, Florida, is one of 13 fields discovered along the Sunniland producing trend, producing from paleotopographic highs associated with shelfal patch reefs and high-energy bioclastic deposits. Deposition of the Sunniland Limestone, as determined from detailed stratigraphic and microfacies analysis (using core, thin sections, and well logs), occurred in three transgressive-regressive packages or sequences: the lower, middle, and upper Sunniland. Each sequence is further divided into successive shallowing-upward intervals or parasequences. The dolomite reservoirs at Raccoon Point field occur at the top of the middle Sunniland and within the upper Sunniland. They are interpreted as high-energy deposits formed from bioclastic debris and as a network between rudist mounds. ...

Science.gov (United States)

PMID:21671451

Science.gov (United States)

... wherever possible. The primary interface for mechanical modeling is through PATRAN, a ... PATRAN Neutral File. PATRAN ...

CERN Document Server

A simple experiment to observe weak localization in thin Ag films is presented. A clear theoretical signature of weak localization is predicted in mangetoresistive measurements of thin films samples. We present a simple method for making thin Ag film samples, using evaporative deposition, and observing the small magnetoresistive signal, using a resistance bridge technique. Typical results from our students show that Ag films show the predicted behavior for weak localization with spin effects. These effects can be easily observed in a liquid helium dewar.

International Nuclear Information System (INIS)

(1 Feb 1975). Netherlands Rollin, DF Robinson, JE McMaster Univ.,

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This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

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In this work, we describe the fabrication and operating characteristics of GaAs/AlGaAs thin film solar cells processed by the epitaxial liftoff (ELO) technique. This technique allows the transfer of these cells onto glass substrates. The performance of the lifted-off solar cell is demonstrated by means of electrical measurements under both dark and illuminated conditions. We have also optimized the light trapping conditions in this direct-gap material. The results show that good solar absorption is possible in active layers as thin as 0.32 {mu}m. In such a thin solar cell, the open circuit voltage would be enhanced. We believe that the combination of an epitaxial liftoff thin GaAs film, and nano-texturing can lead to record breaking performance. {copyright} {ital 1997 American Institute of Physics.}

Science.gov (United States)

... Report Date : JUL 1961. Pagination or Media Count : 39. Abstract : Open-ende Terms: Electrohydraulic forming, Magnetic forming. ...

Science.gov (United States)

in pulse applications such as magnetic forming. ... In magnetic-forming electric circuitry, the ..... Aspects of Electrohydraulic land Magnetic Forming. ...

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

International Nuclear Information System (INIS)

We revisit our original papers on the burst mode of accretion by incorporating a detailed energy balance equation into a thin-disk model for the formation and evolution of circumstellar disks around low-mass protostars. Our model includes the effect of radiative cooling, viscous and shock heating, and heating due to stellar and background irradiation. Following the collapse from the prestellar phase allows us to model the early embedded phase of disk formation and evolution. During this time, the disk is susceptible to fragmentation, depending upon the properties of the initial prestellar core. Globally, we find that higher initial core angular momentum and mass content favors more fragmentation, but higher levels of background radiation can moderate the tendency to fragment. A higher rate of mass infall onto the disk than that onto the star is a necessary but not a sufficient condition for disk fragmentation. More locally, both the Toomre Q-parameter needs to be ...

International Nuclear Information System (INIS)

Suspension direct current plasma spraying allows achieving finely structured coatings whose thickness is between few tens and few hundreds of micrometres. Drops (200-300 ?m in diameter) or liquid jets are mechanically injected in the plasma jet. With radial injection they are rapidly (a few ?s) fragmented into droplets (a few ?m in diameter). The latter are vaporized (in a few ?s) and the solid particles contained in suspension droplets are accelerated and melted by the plasma jet. As in conventional plasma spraying (CPS), much smaller splats (with diameters between 0.2 and 3 ?m and thicknesses between 30 and 200 nm) are arranged in layers up to form the coating. The low inertia of particles requires spray distances between 40 and 60 mm which induces plasma heat fluxes up to 22 MW m-2 participating in coating densification. Even more than in CPS, the plasma jet fluctuations, particularly for plasmas containing di-atomic gases, perturb drops penetration and ...

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Large depositional oil traps (Priob, Sugmut, etc.) have been discovered in the West Siberian Neocomian. Sequence stratigraphic analysis of well logs and seismic reflection profiles demonstrate that reservoirs of these fields represent sands deposited during lowstand, transgressive and highstand phases of relative sea level cycles. Transgressions and regressions advanced in regional longitudinal and local latitudinal directions. The regional longitudinal pattern is dominated by westward prograding clinoforms formed as the sediment supply exceeded the accommodation space. Local northward and northwestward prograding complexes appear to be controlled by local basin-floor topography. In each systems tract, the coastal zones were landward from the shelf-breaks resulting in dominance of marine facies at each depositional shelf-edge. Lowstand systems tracts are represented on the upper slope by prograding wedges with thin shelfal equivalents or ...

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Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2 x the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the ...

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After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for ...

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Seismic transects in this area show a strongly reflective Moho of generally low relief, which, in the area of modern transects, consists of a thin zone (< 2 km thick) of short reflectors. The upper mantle is transparent and has a P{sub n} of 7.8-8.0 km/s similar to much of the western US. A lower crustal zone, 2-13 km thick, has variable internal reflectivity and a relatively low velocity of 6.6-6.8 km/s. Upper mantle peridotite xenoliths show both ductile and brittle deformational features and have structures and composition affected by magmatic intrusion; intrusions form complex dike systems and extensive zones of grain boundary infiltration in peridotite xenoliths. Whereas melt infiltration preceded and followed ductile deformation, brittle deformation, represented by closely spaced joint systems and faults, followed ductile deformation and is related to the youngest magmatic episodes. Lower crustal xenoliths are dominantly ...

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The objective of the research was to develop a procurement method for small-diameter pulpwood based on chain-flail delimbing-debarking method. The study consisted of four parts: Development of the chain-flail delimbing-debarking method (based on Peterson Pacific DDC 5000 device); Combined chain-flail delimbing and drum-debarking; Processing and procurement of the chain-flail delimbing chips and; Intensifying of the timber debarking in chain-flail delimbing. The project was coordinated by Metsaeteho, and it was carried out as cooperation between Metsaeteho, the Finnish Forest Research Institute (METLA), VTT Energy, Pertti Szepaniak Oy and Enso-Gutzeit Oy. A calculation model, by which it is possible to determine the costs of pulpwood chips and fuel-rawmaterials formed beside the pulpwood chips while using different kinds of procurement methods and chains, was developed for chain-flail delimbing-debarking-chipping method based on utilization of Peterson Pacific ...

International Nuclear Information System (INIS)

Epitaxial CeO_2 buffer layers were fabricated by pulsed laser deposition (PLD) on r-cut sapphire substrates. An atomically flat CeO_2 surface with a high density of nanodots was formed by a self-assembly process. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy investigation showed that the nanodots were CeO_2 other than impurities. YBa_2Cu_3O_7_-_#delta# (YBCO) thin films were then grown on the annealed and the as-grown CeO_2-buffered sapphires by PLD. The transport measurement results showed that the nanodots enhanced the effective pinning potential and significantly increased critical current density (J _c). Especially, YBCO films with an annealed CeO_2 buffer layer showed a high J _c peak when the applied field was directed along the c-axis of YBCO. Cross-section transmission electron microscopy investigation revealed that the J _c peaks in YBCO with annealed CeO_2 buffer layer is caused by c-axis ...

International Nuclear Information System (INIS)

The effect of uniaxial tensile stress on intergranular corrosion (IGC) of AA2024-T3 was studied using the foil penetration technique. Standard ASTM G49 fixed-displacement jigs were modified to allow the use of sheet samples, which were then attached to an electrochemical cell as in the foil penetration setup. The time for IGC to penetrate samples of varying thickness was monitored. This method provides a new approach to bridge the gap between IGC and intergranular stress corrosion cracking (IGSCC). Samples with various orientations relative to the rolling direction were studied in 1.0 M NaCl at controlled anodic potentials. Potentiodynamic polarization measurements indicated that the two breakdown potentials typically observed for AA2024-T3 were lower for stressed samples than for unstressed samples, and the current at a given potential was higher. The penetration rate depended on potential and was higher for stressed samples than for unstressed samples. The primary ...

Energy Technology Data Exchange (ETDEWEB)

The corrosion properties of sputtered molybdenum and molybdenum silicide films in hydrochloric acid (HCl) have been studied by means of potentiodynamic measurements. Contributions from the substrate to the corrosion behaviour was avoided by depositing the films on inert aluminium oxide (Al{sub 2}O{sub 3}). The compositions studied were Mo, MoSi{sub 0.58}, MoSi{sub 1.04}, MoSi{sub 1.4} and MoSi{sub 1.9-2.1}. Characterisation of the samples was made by X-ray diffraction (XRD) and scanning electron microscopy (SEM) before and after corrosion. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) were used to analyse the polarised films. Corrosion of Mo{sub 3}Si was found in the molybdenum-rich samples (MoSi{sub 0.58}) containing the two phases Mo{sub 3}Si and Mo{sub 5}Si{sub 3}. Polarisation curves for these films showed one passivation peak at 228 mV vs. the saturated calomel electrode (SCE). The MoSi{sub 1.9-2.1} films had the best corrosion properties of the ...

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This paper discussed the lithological characteristics of tight gas reservoirs, including the diagenetic characteristics, diagenetic environment and diagenetic sequence. The link between porosity, the sedimentary environment, lithology, diagenesis and basin tectonics was examined in order to determine how tight reservoirs were formed. The study focused on the Changbei gas field located in Yishan Slope of the Ordos Basin in China. The main pay zone reservoir is the Upper Paleozoic Lower Permian Shanxi sandstone which lies at a depth of 2700-2950 m. This low porosity, low permeability tight gas reservoir was deposited in a coal bearing acid environment which controlled the diagenesis sequence. The early carbonate cement was not well developed because the original pore water was acidic with non saturated calcium carbonate. However, compaction has significantly reduced the original pore and pore volume. The acidic environment caused large amounts of secondary quartz ...

International Nuclear Information System (INIS)

Research highlights: The dental implant of titanium could be modified by anodic oxidation. It was found that incorporation of strontium ions into the matrix increase the bone formation. In this study, we try to investigate the effect of corrosion property and bioactivity on coatings containing strontium by anodic oxidation. The results suggest that coatings containing strontium on titanium by anodic oxidation has the potential to show the stability and bioactivity in the clinical use. - Abstract: Pure titanium (Ti) and titanium alloys are considered as bio-inert materials in clinical use. Bioactivity is the ability to induce bone-like apatite on the material surface. The micro-arc oxidation (MAO) technique is an effective method for improving the surface properties of titanium. The aim of this study was to investigate the bioactivity and corrosion behavior of MAO coatings containing strontium, which is beneficial for biological performance. The bioactivity of materials was evaluated ...

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Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material galvanically coupled with a noble intermetallic compound of Zr(Fe{sub 0.66}Cr{sub 0.33}){sub 2} was ...

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The thermal radiation which generated from the patterned Ta/Pt/Ta thin heater achieved a high temperature up to 1010 {sup o}C under applied current of 2.4 A. In order to reduce an electromigration at high current of 2 A, a Ta capping layer was placed on the Pt layer instead of conventional capping layer, such as SiNx and CoWP. Under the thermal radiation at the applied current of 2 A in the Ta/Pt/Ta thin heater, the Ta capping layer enhanced the lifetime of the Pt thin heater up to 5 h. A stamping process for the crystallization of a-Si was performed for 40 samples using the Ta/Pt/Ta thin heater. For all samples, a-Si has been selectively crystallized and Raman peaks were located near 519 cm{sup -} {sup 1}. These results indicated that the thermal radiation of the Ta/Pt/Ta thin heater was maintained constantly due to the Ta capping.

Energy Technology Data Exchange (ETDEWEB)

An experimental study was conducted to determine the effects of ply thickness in composite laminates on thermally induced cracking and changes in the coefficient of thermal expansion (CTE). After a few thermal cycles, laminates with thick-plies cracked, resulting in large changes in CTE. CTE`s of the thin-ply laminates were unaffected by microcracking during the first 500 thermal cycles, whereas, the CTE`s of the thick-ply laminates changed significantly. After about 1500 cycles, microdamage had also reduced the CTE of the thin-ply laminates to a value of about half of their initial value.

International Nuclear Information System (INIS)

A study of the thin gold film growth, during the deposition on glass substrate under UHV conditions at low temperatures, is presented. The complementary methods, the atomic force microscopy and grazing incidence x-ray reflectometry, are used for the research. It is shown that due to variation of the time of deposition from 2 to 50 min different kinds of thin Au films nanostructures are obtained: from discontinuous films consisting of isolated islands, via formation of the chains of islands, up to continuous films. (author)

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We compared the characteristics on thin-section CT images with the histological structure of thirty-four surgically resected peripheral lung lesions 30 mm or less in diameter with a greater than 50% area of GGA on thin-section CT. Pathologically, focal area of GGA corresponded to alveolar replacement growth of tumor or interstitial fibrotic thickening of inflammation. It is considered that determination of the GGA in small peripheral lung lesions on thin-section CT is useful for the diagnosis of early adenocarcinomas. (author)

Science.gov (United States)

Discussion of an electrohydraulic and magnetic forming process

International Science & Technology Center (ISTC)

Experimental and Theoretical Study of the Residual Nuclide Production in 40-2600 MeV Proton-Irradiated Thin Targets of ADS Basic Materials

International Nuclear Information System (INIS)

Short communication. 2 figs.

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The authors report the fabrication and characterization of a low temperature (200--400 C) thin film gas sensor constructed from a MOCVD-grown yttria-stabilized zirconia (YSZ) layer sandwiched between two platinum thin film electrodes. A reproducible gas-sensing response is produced by applying a cyclic voltage which generates voltammograms with gas-specific current peaks and shapes. Growth conditions are optimized for preparing YSZ films having dense microstructures, low leakage currents, and maximum ion conductivities. In particular, the effect of growth temperature on film morphology and texture is discussed and related to the electrical and gas-sensing properties of the thin film sensor device.

UK PubMed Central (United Kingdom)

The results of a histological study of normal osteoid tissue in man, the monkey, the dog, and the rat, using thin microtome sections of plastic-embedded undecalcified bone, are described. Osteoid tissue...Full Text Available

Science.gov (United States)

... 2.2.1 Polymerization of DVB Under Pressure DVB was polymerized at 300*C in thin-walled Pd-Ag capsules at pressures up to 60,000 psi. ...

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... Abstract : Single crystals of Pb(x)Sn(1-x)Te alloy have been grown with o = or thin film evaporator. ...

Science.gov (United States)

... to-continuum X-ray intensity ratio [5]. For ence in the means [7]. In addition, washing samples on thin films, the characteristic X- lymphocytes in NH ...

International Nuclear Information System (INIS)

The main purpose of this work is to evaluate the role of CT in identifying other morphological signs of met static lymph node involvement from non small cell bronchogenic carcinoma. This is done to improve N staging, a critical step in this disease. In fact, since diameter is the only criterion used to distinguish normal form abnormal lymph nodes, mediastinal CT only has 80% diagnostic accuracy. 137 patients with known or suspected lung cancer were examined with Helical CT during early and late arterial phases (2 min. delay, 3 mm thickness, 5 mm inter slice gap) to depict node characteristics. Mediastinal lymph nodes, located according to the American Thoracic Society mapping, were considered normal when they were not visible or, if visible, less than 1 cm in diameter and of homogeneous density; lymph nodes over 1 cm in diameter and homogenous density were considered reactive. A lymph node was considered metastatic when, independent of size, the following signs ...

Energy Technology Data Exchange (ETDEWEB)

TiO{sub 2} is a vital material in several technologies including, photocatalysis, gas sensing, biomaterials and optical coatings. Among the several crystal structures of this oxide, rutile has the highest density and microhardness, the highest index of refraction and the highest temperature stability. The processing of dense polycrystalline materials often includes the addition of a liquid-forming phase at higher temperatures. This technique is known as liquid-phase sintering and has been studied extensively. Rutile boundaries containing an amorphous phase have been used to study boundary migration and grain-boundary grooving. Visible-light (VLM), scanning electron (SEM) and transmission electron microscopy (TEM) in addition to electron-backscatter diffraction (EBSD) and a focused-ion beam (FIB) tool were used to characterize boundary migration in rutile. EBSD analysis was carried out on a Philips XL30 FEG SEM equipped with a DigiView 1612 high-resolution, ...

International Nuclear Information System (INIS)

Surface-sensitive UV photoelectron yield spectroscopy was employed to study electron acceptor levels at surfaces of chalcopyrite structure Cu-In-Se thin films. Surface Fermi level pinning was observed for Cu-rich films. Shallow acceptor levels ascribable to defects Cu_I_n and V_C_u were observed for near-stoichiometric and In-rich films respectively. (orig.).

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Crude N,N-dialkylcarbamoylmethylphosphonates and phosphine oxide extractants, and particularly crude dihexyl N,N-diethylcarbamoylmethylphosphonate and octylphenyl N,N-diisobutylcarbamoyl phosphine oxide, are purified by distilling the crude materials in a thin film evaporator. Preferably, the crude materials are reacted with concentrated hydrochloric acid and then with aqueous sodium hydroxide prior to distillation in the thin film evaporator to hydrolyze impurities contained in them. The purified extractants are useful for extracting actinides and lanthanides from liquid waste streams. (author).

International Nuclear Information System (INIS)

The phenomenological description of the giant magnetoresistance effect as well as discussion of the requirements which must be fulfilled in giant magnetoresistance thin film structures are given in the first part of our review. In the second part the magnetization reversal and giant magnetoresistance effect of antiferromagnetically coupled multilayers, spin Valve and pseudo-spin valve thin film structures are explained. For these structures we also discuss the influence of the structure defects such as surface roughness and pinholes on the giant magnetoresistance effect. (author)

Energy Technology Data Exchange (ETDEWEB)

A simple and continuous model for the on-state current of polysilicon thin-film transistors, suitable for implementation in circuit simulators, is presented. The model includes the potential barrier at the grain boundaries, the channel length modulation and the excess current due to impact ionization. Comparison between measured output characteristics and the model shows excellent agreement over wide range of bias voltages and for devices with different gate lengths.

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline processing by inert gas condensation has the inherent advantages of generating: (1) high surface area nanoclusters, (2) non-stoichiometric oxides, and (3) high dispersions of dopants. This approach is exploited in the synthesis of fluorite-structured catalysts for SO{sub 2} reduction by CO. Nanocrystalline CeO{sub 2{minus}x}, La-doped CeO{sub 2{minus}x}, and Cu-doped CeO{sub 2{minus}x} were produced by magnetron sputtering from a pure or mixed metal target, followed by controlled oxidation of the metallic clusters. The as-prepared doped and undoped nanocrystalline CeO{sub 2{minus}x} materials were found to be excellent catalysts for complete SO{sub 2} conversion to elemental sulfur. Undoped nanocrystalline CeO{sub 2{minus}x} enabled light-off at 460 C, a temperature {approximately} 120 C lower than that over polycrystalline CeO{sub 2}, which is a novel effective catalyst itself. The high catalytic activity of the nanocrystals was associated with ...

Science.gov (United States)

Lunar resource utilization has focused principally on the extraction of oxygen from the lunar regolith. A number of schemes have been proposed for oxygen extraction from Ilmenite and Anorthite. Serendipitously, these schemes have as their by-products (or more directly as their "waste products"), materials needed for the fabrication of thin film silicon solar cells. Thus lunar surface possesses both the elemental components needed for the fabrication of silicon solar cells and a vacuum environment that allows for vacuum deposition of thin film solar cells directly on the surface of the Moon without the need for vacuum chambers. In support of the US space exploration initiative a new architecture for the production of thin film solar cells on directly on the lunar surface is proposed. The paper discusses experimental data on the fabrication and properties of lunar glass substrates, evaporated lunar regolith ...

International Nuclear Information System (INIS)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V_G_S = V_D_S/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated ...

International Nuclear Information System (INIS)

From the results of the In-Service Inspection (ISI) measuring the wall thickness of outlet (hot-leg side) feeder pipes performed at two Canadian nuclear power plants, Point Lepreau and Gentilly-2 in 1995 and 1996, respectively, the wall thinning degradation of feeder pipes at the bend part was found to be much more severe than expected. It has been well known that such wall thinning of feeder pipes is caused by the flow accelerated corrosion (FAC) which is one of the mechanical-chemical degradation mechanisms affecting the integrity of piping systems. For the Wolsung unit 1, the wall thickness measurements have been performed during every overhaul period since 1996. The wall thinning rates at the bends of outlet feeder pipes were assessed to exceed the design value. However, for the Wolsung units 2, 3 and 4, the wall thinning rates of all the outlet feeder pipes were assessed not to exceed it. The ...

Science.gov (United States)

The quasi-static normal indentation of sandwich panels with quasi-isotropic laminated composite skins and honeycomb or foam cores, by spherical indentors, has been investigated using experiments and finite element analysis. The experimental program emphasized the effects of indentor size on the resulting load indentation responses, failure mechanisms in the skin and the core, and the measurement of contact areas between indentor and the target. The sandwich panels were indented up to the initiation of skin fracture and the resulting contact data was used to characterize contact power laws. A non-linear finite element model was developed based on the experimental observations to systematically explore the indentation behavior of diverse sandwich configurations and to investigate the contact pressure distributions. The finite element model was used as an experimental tool in the development of a simple non-dimensional semi-empirical model that was based on the Graeco-Latin-square ...

Science.gov (United States)

No Abstract Available

Science.gov (United States)

PMID:5924644

Science.gov (United States)

PMID:8677780

Science.gov (United States)

the techniques employed at present, some of which, like magnetic forming and hotdrape forming, are in experimental stages. Published October 1965. ...

Science.gov (United States)

... fields, materials can be subjected to energy densities exceeding those realized in high explosives, a fact which forms the basis for magnetic forming ...

Energy Technology Data Exchange (ETDEWEB)

Aqueous solutions of Al/sub 2/(SO/sub 4/)/sub 3/ (1.05 g/100 ml), AlCl/sub 3/ (0.82 g/100 ml) and Ca(OH)/sub 2/ slurry (0.94 g/50 ml) were mixed in various volume ratios and passed through a filter. White cakes left on the filter consisted mainly of ettringite (6CaO.Al/sub 2/O/sub 3/.3SO/sub 3/.32H/sub 2/O). The cakes were then calcined at various temperatures of 300/sup 0/ -- 1000/sup 0/C for 30 and 60 min and pulverized to 80 -- 200 mesh powders. The adsorption capacity of the powders for U(VI) ions dissolved in aqueous solutions was determined by immersing 0.100 g of their powders in 50 ml of the aqueous solution containing 100 ppm of U(VI) ions mainly in the form of (UO/sub 2/(CO/sub 3/)/sub 3/)/sup 4 -/ for 2 hours. The results obtained were summarized as follows. 1) Among the powders prepared, those of the oxide compositions, 2.9CaO.Al/sub 2/O/sub 3/.1.4SO/sub 3/ and 2.5CaO.Al/sub 2/O/sub 3/.1.2SO/sub 3/, all fired at 500/sup 0/C or 600/sup 0/C showed high ...

Energy Technology Data Exchange (ETDEWEB)

As thin films become increasingly popular (for solar cells, LEDs, microelectronics, batteries), quantitative morphological information is needed to predict and optimize the film's electronic, optical and mechanical properties. This quantification can be obtained quickly and easily with X-ray diffraction using an area detector and synchrotron radiation in two simple geometries. In this paper, we describe a methodology for constructing complete pole figures for thin films with fiber texture (isotropic in-plane orientation). We demonstrate this technique on semicrystalline polymer films, self-assembled nanoparticle semiconductor films, and randomly-packed metallic nanoparticle films. This method can be immediately implemented to help understand the relationship between film processing and microstructure, enabling the development of better and less expensive electronic and optoelectronic devices.

British Library Electronic Table of Contents (United Kingdom)

Dopant-free Bi2Ti2O7 thin films with pyrochlore structure and La-doped bismuth titanate thin films have been fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and UV?Vis spectrophotometry in this study. Their photocatalytic activities have been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the highest photocatalytic activity have been found. Moreover, the effects of La-doping on the phase transformation and the photocalalytic activity have been studied. It has been deduced from the experiment result that substituted La3+ ions can act as a stabilizer of Aurivillus phase BLT and a grain?growth inhibitor in BLT thin films.

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The measurement of local heat transfer coefficients is necessary to record the basic phenomena of heat transfer in thin-film apparatuses. For this reason the so-called electrochemical analogy method was developed and used for this application. The electrochemical method implies a specifically composed electrolyte which substitutes the fluid to be evaporated in the thin-film apparatus. Using the redox electrolyte (0,025 kmol/m/sup 3/ K/sub 4/Fe(CN)/sub 6/ resp. k/sub 4/Fe(CN)/sub 6/ and 2nNaOH) the viscosity was, for the first time, thickened until 0.4 Pa s by the help of hydroxyethyl-cellulose.

International Nuclear Information System (INIS)

High-resolution electron microscope observations confirm the presence of small crystallites in thin TbFeCo films protected by Si_3N_4 overcoats. Selected area electron diffraction patterns in top-view projection indicate that the crystals have a face-centered-cubic structure. Microscope analysis reveals grain growth following annealing of these protected thin films at 200 degree C in vacuum, and Kerr measurements yield large reductions in coercivity relative to the room-temperature value. The typical grain size visible in top-view observations increases from about 3 nm in the as-deposited samples to about 30 nm after annealing at 200 degree C for 36 h while the static coercivity, H_c, drops by about 40%. The fcc structure of the crystals is retained after annealing.

International Nuclear Information System (INIS)

Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr_2N and CrN phases was observed when 30% and 40% N_2 were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.

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Silicon thin film with thickness in range 1000-5300 A deposited on rough Cu foil by a radio frequency magnetron sputtering is used as anode materials for Li-ion rechargeable batteries. The SEM, XRD and TEM analysis reveals that the Si thin film has a floccular nano-sized multi-crystalline structure. Li ions insertion/extraction evaluation is performed mainly with constant current charge/discharge cycling and cyclic voltammetry (CV) at room temperature. The cycleability and reversible discharge capacity are found to depend on the film thickness, and thinner films give larger accommodation capacity. A 3120 A Si film provides a reversible specific capacity over 3500 mA hg{sup -1} with excellent cycleability under 0.5 C charge/discharge rate.

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Ion Beam Induced Luminescence (IBIL) and Ion Beam Induced Charge Collection (IBICC) have been applied in the study of the luminescence emission efficiency and investigation of the homogeneity of the luminescence emission in phosphors. The IBIL imaging was performed by using sharply focused ion beams or broad/partially-focused ion beams. The luminescence emission homogeneity in samples was examined to reveal possible distributed crystal-defects that may lead to the inhomogeneity of the luminescence emission in samples.The purpose of the study is to search for suitable luminescent thin films that have high homogeneity of luminescence emission, large IBIL efficiency under heavy ion excitation, and can be placed as a thin layer on the top of microelectronic devices to be analyzed with Ion Photon Emission Microscopy (IPEM). The emission yield was found to be low for organic materials, due to saturation of the light output dependence on the energy ...

Science.gov (United States)

Most palladium thin film based hydrogen gas sensors have response and recovery times that are too long to make them useful in vehicular and stationary gas leak detection applications. In contrast, a palladium-silver thin film based microcantilever (MC) hydrogen gas microsensor is reported herein with near ideal response characteristics for use in these hydrogen economy related applications. Specifically, 3-10 second response and recovery times have been measured for these sensors in contrast to previous sensor response measurements of several to tens of minutes using Pd thin film and MC based sensing techniques. The much reduced response times observed in the present study are attributed to a wet chemical Pd-Ag thin film deposition technique and a gas conditioning protocol that produces a highly nanostructured, porous film that rapidly adsorbs and desorbs H2, allowing rapid equilibration with the H2 ...

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Optical absorptance spectra of A-15 compounds were taken using a calorimetric technique in the range 0.2 eV to 4.0 eV. Thermomodulation spectra were taken on several A-15 sputtered films.

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The possibility to compress and to split laser pulses at their nonlinear optical transmission through semiconductor films was investigated

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Two manufacturing processes have been developed for fabricating PLZT bonded lens assemblies (BLA's) for the USAF EEU-2/P Thermal/Flash Protective Goggle. One process utilizes thin Sylgard spacers which remain in the BLA to establish bond thickness between...

British Library Electronic Table of Contents (United Kingdom)

Ferroelectric thin films such as BST, PZT and PLZT are extensively being studied for the fabrication of DRAMS since they have high dielectric constant. The large and reversible remnant polarization of these materials makes it attractive for nonvolatile ferroelectric RAM application. In this paper we report the characterization of Ba0.7Sr0.3TiO3 (BST) thin films grown by pulsed laser ablation on oxide electrodes. The structural and electrical properties of the fabricated devices were studied. Growth of crystalline BST films was observed on La0.5Sr0.5CoO3 (LSCO) thin film electrodes at relatively low substrate temperature compared to BST grown on PtSi substrates. Electrical characterization was carried out by fabricating PtSi/LSCO/BST/LSCO heterostructures. The leakage current of the heteros...

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During Phase II multi-junction solar cell will be grown on the large grain thin film produced during Phase I on flexible/low cost metal foil substrate. ...

UK PubMed Central (United Kingdom)

The curvature elastic modulus (bending stiffness) of stearoyloleoyl phosphatidylcholine (SOPC) bilayer membrane is determined from membrane tether formation experiments. R. E. Waugh and R. M. Hochmuth...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract Visible blue cathodoluminescence (CL), photoluminescence (PL), x-ray excited optical luminescence (XEOL) and electroluminescence (EL) via Zf free excitonic emission have been obtained from CuBr thin films deposited on glass, Cr coated glass, GaAs and Si substrates. In addition to the Zf emission several peaks corresponding to Cu+ emissions via 3d94s - d10 transitions were observed on the AC EL spectrum at 2.10, 2.7, 3.03, 3.07 and 3.80 eV. X-ray diffraction (XRD) measurements confirmed that the vacuum evaporated CuBr thin films grow preferentially with a (111) orientation irrespective of the substrate. While the AC voltage source was found to have no detrimental effects on CuBr thin films, cathodic deposition of Cu metal via electrolytic decomposition was observed under steady sta...

UK PubMed Central (United Kingdom)

BackgroundPrevious research has demonstrated that exposure to images depicting the thin female ideal has negative effects on some females' levels of body dissatisfaction. Much of...Full Text Available

CERN Document Server

The aim of this work was to study the possibility of producing a fast switching optical thin film device to react to laser radiation in the visible/near infrared region of the spectrum. The switching mechanism was to be thermally driven. A computer program was written to enable the effects of changes of the refractive index of a component of a multilayer thin film stack to be modelled. Attempts to use the phase transition in vanadium dioxide were unsuccessful because, in the spectral region of interest, the 'open-state' absorption was too great. A class of materials known as 'the bronzes' was identified as being potentially useful. Attempts were made to produce thin films of bronze compounds of vanadium, tungsten and molybdenum by the techniques of conventional thermal evaporation and laser ablation for further studies. The former technique appeared to suffer from problems of decomposition of the source material. The latter ...

International Nuclear Information System (INIS)

Certain applications are described of radionuclide X-ray fluorescence analysis in the ore dressing industry, in the manufacture of building materials, in metallurgy, pharmacy, in the chemical, photographic and paper industries, in space exploration, in archeology and for measuring the thicknesses of thin layers of coatings. (ES).

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Depth resolved positron annihilation studies on Pd/Si thin film system have been carried out to investigate silicide phase formation and vacancy defect production induced by thermal annealing. The evolution of defect sensitive S-parameter clearly indicates the presence of divacancy defects across the interface, due to enhanced Si diffusion beyond 870 K consequent to silicide formation. Corroborative glancing incidence X-ray diffraction (GIXRD), Auger electron spectroscopy (AES) and Rutherford backscattering spectrometry (RBS) have elucidated the aspects related to silicide phase formation and Si surface segregation.

International Nuclear Information System (INIS)

Magnetic materials such as yttrium iron garnet (YIG) are of great importance for its magneto-optic properties and for their potential applications in the domain of optical telecommunications. The deposition of thin films of YIG, on quartz or GGG (gadolinium gallium garnet) substrate, was performed using radio frequency non reactive magnetron sputtering, followed by high temperature annealing which is needed to enhance the crystallinity of the layers. Rutherford backscattering spectrometry RBS was used to determine the thickness and stoichiometry of the performed layers in order to investigate correlations between growth conditions and the quality of the final material. RBS measurements showed the influence of the deposition time and the temperature substrate on the film growth and its stoichiometry. (author)

International Nuclear Information System (INIS)

The symposium, Polycrystalline Thin Films - Structure, Texture, Properties, and Applications III, was held at the 1997 Materials Research Society Spring Meeting on March 31--April 4 in San Francisco, California. The topics and investigations were interdisciplinary in nature, and ranged from fundamental to technological. Specifically, the work presented in this volume includes film growth, texture and structural evolution, phase transformation, characterization of grain boundaries and interfaces, stress analysis, and works on polycrystalline Si and SiGe films and devices. Fifty four papers were processed separately for inclusion on the data base.

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The application of medium energy ion scattering in combination with channelling and blocking to the study of the initial stages of palladium silicide formation is discussed. After a brief description of the experimental arrangement and method, the effects on the Rutherford backscattering spectra of depositing small quantities of palladium on clean Si(111) are reported. The uniformity and thermal stability of thin palladium silicide films grown at room temperature were measured. Finally, channelling and blocking results were used to carry out a structural analysis of thin epitaxial Pd/sub 2/Si layers.

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The half-metallic Heusler alloy Ni{sub 2}MnIn is of high interest for use in spin electronics since at the Ni{sub 2}MnIn/InAs interface a spin polarization of 100% is predicted. We prepare high-quality thin films of 20-60nm thickness by co-evaporation and DC magnetron sputtering. Point-contact Andreev reflection spectroscopy yields a spin polarization of up to 54%. By spectral generalized magneto-optical ellipsometry, the dielectric and magneto-optical properties are determined and ferromagnetic behavior below the Curie temperature T{sub C}=318K is proved.

International Nuclear Information System (INIS)

One of the main problems related to optical thin film materials used in high power laser environments is the catastrophic damage caused to them due to laser irradiation. While the influence of ion bombardment on the optical properties of oxide thin films is now a well understood subject, the morphology and crystalline behaviour of these films under ion incidence is not so well studied. Hence, it is of great importance to investigate the effects of ion bombardment during growth on the microstructure and crystalline behaviour of oxide materials.

International Nuclear Information System (INIS)

We discuss the consequence of local duality for elastic scattering, and derive a model-independent equation between structure functions at x ? 1 and elastic electromagnetic form factors. Then the electromagnetic form factors of proton are discussed using the quark-hadron duality theory. We also debate the form factor of proton in a bound state. It may be an effective approach to study the form factor of proton in media.

UK PubMed Central (United Kingdom)

A 24-item short form of the 96-item Developmental Behaviour Checklist was developed to provide a brief measure of Total Behaviour Problem Score for research purposes. The short form Developmental...Full Text Available

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Principle advantages of magnetic forming for part manufacture appear to lie ... to be an area of great potential for the magnetic forming process. We have a ...

UK PubMed Central (United Kingdom)

To express growth-related changes in physiologic or other functions in forms usable for kinetic modeling, we are interested in identifying regular relationships that take the form of simple mathematical...Full Text Available

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Magnetic Forming (10). - Forming of metals (the metal needs only to be an electrical conductor) is achieved without physical contact ...

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Magnetic coil pressure wave generation for magnetic forming

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The production and characterisation of thin films made from molybdenum sulphide, molybdenum selenide, tungsten sulphide and tungsten selenide are described. The electronic properties of the thin films were examined by Hall measurements and by thermal sensors. For the MoSe[sub 2] films, the majority of the samples were n-conducting and p-conduction was only found for a few examples. All the other films (MoS[sub 2], WS[sub 2], WSe[sub 2]) were p-conducting. The electrical transport properties of the thin films are comparable to those of single crystals. With these thin films as absorber materials, it was possible for the first time to produce the polycrystalline solid n-ZnO/p-MoSe[sub 2], n-ZnO/WSe[sub 2], n-ZnO/WS[sub 2]- and n-ITO/WS[sub 2] solar cells. In spite of not yet optimized diode geometry (lateral build-up), a maximum short circuit current of I[sub SC] = 18 mA/cm[sup 2] was achieved for the ...

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Fe{sub x}Zn{sub 1-x} alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K{beta}/K{alpha} x-ray intensity ratios of Zn and Fe in Fe{sub x}Zn{sub 1-x} thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5 keV photons emitted by a 50 mCi {sup 241}Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150 eV at 5.9 keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn-Fe alloys. It was found that the K-shell x-ray intensity ratio changed in Fe{sub x}Zn{sub 1-x} thin films for different values of x. ...

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The long-term stability of pentacene thin-film transistors (TFTs) encapsulated with a transparent SnO{sub 2} thin-film prepared by ion beam-assisted deposition (IBAD) was investigated. After encapsulation process, our organic thin-film transistors (OTFTs) showed somewhat degraded field-effect mobility of 0.5 cm{sup 2}/(V s) that was initially 0.62 cm{sup 2}/(V s), when a buffer layer of thermally evaporated 100 nm SnO{sub 2} film had been deposited prior to IBAD process. However, the mobility was surprisingly sustained up to 1 month and then gradually degraded down to 0.35 cm{sup 2}/(V s) which was still three times higher than that of the OTFT without any encapsulation layer after 100 days in air ambient. The encapsulated OTFTs also exhibited superior on/off current ratio of over 10{sup 5} to that of the unprotected devices ({approx}10{sup 4}) which was reduced from {approx}10{sup 6} before aging. Therefore, the enhanced ...

Science.gov (United States)

Regional cortical thickness was evaluated using CIVET processing of 3D T1-weighted images (i) to compare the variation in cortical thickness between 33 participants with fetal alcohol spectrum disorders (FASD) aged 6-30 years (mean age 12.3 years) versus 33 age/sex/hand-matched controls, and (ii) to examine developmental changes in cortical thickness with age from children to young adults in both groups. Significant cortical thinning was found in the participants with FASD in large areas of the bilateral middle frontal lobe, pre- and post- central areas, lateral and inferior temporal and occipital lobes compared to controls. No significant cortical thickness increases were observed for the FASD group. Cortical thinning with age in a linear model was observed in both groups, but the locations were different for each group. FASD participants showed thinning with age in the left middle frontal, bilateral precentral, bilateral ...

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Various methods for storing hydrogen have been examined in an effort to find ways to store hydrogen in increasingly smaller volumes with decreasing weight of the whole hydrogen storage system. Metal hydrides, in which hydrogen is chemically bound to a metal atom, are considered to be very promising candidates for hydrogen storage because they have high gravimetric and volumetric storage capacities. This study investigated the effect of different magnesium (Mg) and aluminium (Al) ratios on the absorption and desorption properties of thin films. Neutron reflectometry (NR) was used in this study to better understand the absorption and desorption properties of commercially promising hydrogen storage materials. The large negative scattering length of hydrogen atoms changes the reflectivity curve substantially, so that NR can determine the total amount of stored hydrogen as well as the hydrogen distribution along the film normal, with nanometer resolution. In order to ...

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There is a growing interest in using {sup 242m}Am as a nuclear fuel. The advantages of {sup 242m}Am as a nuclear fuel derive from the fact that {sup 242m}Am has the highest thermal fission cross section. The thermal capture cross section is relatively low and the number of neutrons per thermal fission is high. These nuclear properties make it possible to obtain nuclear criticality with ultra-thin fuel elements. The possibility of having ultra-thin fuel elements enables the use of these fission products directly, without the necessity of converting their energy to heat, as is done in conventional reactors. There are three options of using such highly energetic and highly ionized fission products. - Using the fission products themselves for ionic propulsion. - Using the fission products in an MHD generator, in order to obtain electricity directly. - Using the fission products to heat a gas up to a high temperature for propulsion purposes. In this ...

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In this study, WO{sub 3} thin films were grown on glass substrates using an aqueous solution containing tungstate (NH{sub 4}){sub 2}WO{sub 4} as precursor. The substrate temperature incremented from 250 to 500 deg. C, by steps of 50 deg. C. The structural properties were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. Microprobe analyses showed that a balanced stoichiometric composition was obtained for thin films prepared at T{sub s} = 350 and 400 deg. C. The X-ray diffraction analyses showed different structure crystallography in function of the substrate temperature. Moreover, films deposited at 400 deg. C were annealed in air for 2 h at 450 and 500 deg. C, respectively and the structural changes due to heat treatment were studied. Finally, the optical properties of these films were carried out using optical measurements of transmittance T({lambda}) and reflectance R({lambda}) spectra in ...