bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Two Sample Preparation Methods for Determination of Lead in Composite Dust Wipe Samples
Authors: White Kenneth T. , Dewalt F. Gary , Cox David C. , Schmehl Richard , Friedman Warren , Pinzer Eugene A. 
Published: March 2011

Abstract
Sample preparation methods for four-wipe composite dust wipe samples, used by nine different laboratories accredited under the U.S. Environmental Protection Agency (EPA) National Lead Laboratory Accreditation Program (NLLAP), were evaluated to select two methods most likely to provide the best overall performance among multiple laboratories, based on accuracy, precision and practicality of the methods. The best performing methods involved (1) hot nitric acid/hydrogen peroxide digestion and (2) nitric acid ultrasonication. In a second round of testing, two sets of composite dust wipe samples with known amounts of lead were submitted blind to each of the nine laboratories to be prepared for analysis using these two sample preparation methods. Results showed that both methods are capable of meeting all EPA NLLAP requirements for accuracy (recovery) and precision. The ultrasonication method had superior performance at lower cost.
Standardized Polymer Durometry
Authors: Mix A. W. , Giacomin A. J. 
Published: March 2011

Abstract
Polymer durometry is the measurement of the hardness of plastic and rubber materials using an indentor. Many different hardness scales and indentor geometries have been standardized for durometry. Indentation into a solid is governed by linear elastic mechanics, and this paper relates the Young’s modulus to standardized hardness scale reading. We nondimensionalized these indentation mechanics, to uncover a normalized Young’s modulus, Υ, and the dimensionless hardness, ℋ, and then, a new dimensionless indentor stiffness that we call mechanical indentability, Mi. We use Mi for classifying standardized hardness scales. Our results allow practitioners to determine the Young’s modulus from measured hardness. Further, our results can be used to convert between hardness scales, not only between hardness scales of the same indentor geometry, but also between those of differing geometry.
Adsorption of Oxygen in Laser-Induced Amorphous Silicon
Authors: Liu Yung S. , Chiang S. W. , Bacon F. 
Published: March 2011

ABSTRACTAmorphous silicon has been produced on a single crystalline silicon surface by intense UV laser radiation at 266 nm followed by rapid quenching. In addition, formation of oxide of several tens of nanometers has been observed when irradiation takes place in air or in O2 ambient. Various experimental techniques including Transmission Electron Microscopy (TEM), sputtered Auger Electron Spectroscopy (AES), and differential Fourier-transform IR spectroscopy (FT-IR) have been employed to study adsorption of oxygen during rapid melting and resolidification process. The present results suggest a new processing technique for forming thin oxide film, namely, “Laser-induced oxidation.”
A Simple Optical Pyrometer for in Situ Temperature Measurement During Cw Argon Laser Annealing
Authors: Sedgwick T.O. 
Published: March 2011

ABSTRACTA standard optical disappearing hot wire micropyrometer was modified with a long working distance magnifier to enlarge the laser heated spot so that the maximum temperature of the center of the spot could be observed and measured with some certainty. In situ temperature measurements were made on As ion implanted Si <100> chips using an Argon Ion laser with the beam slightly defocused to a 50–100μm diameter spot on the Si surface. The data curves show a linear function of measured temperature with laser power up until the melting point is reached. By using the Si m.p. as a calibration point, the temperature can be reproducibly measured within a few tens of degrees. Comparisons of actual re-growth rates with those calculated from the well known solid state Si regrowth expression as a function of temperature yields good agreement between measured and calculated temperature.
Device Performance of Laser Annealed Double Heterostructure GaAlAs Materials
Authors: Brett M.J. , Rostworowski J.A. , Parsons R.R. , Springthorpe A.J. , Look C.M. , Dyment J.C. 
Published: March 2011

ABSTRACTWe have laser annealed double heterostructure GaAlAs material with homogeneous ruby laser pulses such that maximum laser light absorption occurs in the active layer. With laser anneal intensities sufficient to melt the active layer, the radiative efficiency of the double heterostructures was reduced by a factor of two. Performance of electroluminescent devices fabricated from annealed material was much worse than performance of devices fabricated from unannealed material.
Effects of Pulsed Laser Irradiation on Thermal Oxides of Silicon
Authors: Lloyd Crosthwait D. , Shah Rajiv R. , Brown George A. , Mays Robert 
Published: March 2011

ABSTRACTThe electrical effects associated with pulsed laser irradiation of thermal oxides of silicon were investigated. Three of the functions performed by thermal oxides are control of field effects, junction passivation and electrical isolation. Representative oxide thicknesses suitable for these applications were studied: ≈ 100 nm; ≈ 500 nm and ≥, 1.0 μm respectively. The oxides were irradiated by a repetitively Q-switched Nd 3+:YAG laser operated at the fundamental frequency. The key laser parameters of energy and power density were varied over a wide range, from no change to the onset of discernible change and irreversible damage. The range of energy densities over which the oxide was not electrically degraded was established for each thickness of the oxide. This range of energy densities is compared to the useful range of energy densities for annealing polysilicon and for activating an implant through an oxide. The electrical data was obtained using a mercury probe and through the analysis of a large number of MOS capacitors formed on the irradiated oxides. Parameters measured include: breakdown voltages, surface state charge densities and flat band voltages.
Characterization Techniques For Laser-Annealed Polysilicon on Insulating Layers
Authors: Schott J. T. , Comer J. J. 
Published: March 2011

ABSTRACTVarious characterization techniques are applied to pulsed and cw laser-annealed polysilicon layers deposited on oxide layers. The results are used to compare these techniques as to the type and completeness of information provided, as well as sample preparation requirements and general ease or difficulty of measurement. The techniques employed include scanning electron microscopy (SEM), electron channeling micrographs and selected area channeling patterns (SACP), reflection (high energy) electron diffraction (RHEED), transmission electron microscopy (TEM) and selected area diffraction (SAD), x-ray diffraction, optical techniques and etching techniques.
Thermally-Assisted Pulsed-Laser Annealing of SOS
Authors: Yamada Masayoshi , Yamazaki Ken-Ichi , Kotani Hisakazu , Yamamoto Keiichi , Abe Kenji 
Published: March 2011

ABSTRACTThermally-assisted pulsed-laser annealing has been performed on ion-implanted silicon-on-sapphire(SOS) by irradiating Q-switched(20 nsec) ruby laser light during thermally heating. Raman scattering measurements have been made to estimate the residual strain of the annealed SOS. It was observed that Raman shift of SOS annealed in the temperature range of 400°C to 500°C was very close to that of single crystal silicon and the depolarization factor(the Raman intensity ratio of allowed z(xy)z to forbidden z(xx)z scattering configuration) was infinite, while Raman shift of SOS annealed at room temperature was shifted down to about 5 cm-1 and the depolarization factor was finite. It was found that the residual strain of SOS was relieved by the thermally-assisted pulsed-laser annealing, but the residual strain of SOS annealed at room temperature was inhomogeneous and attained to 7×10−3. The annealing temperature dependences of the residual strains were not explained well with a strictly thermal melting and recrystallization model in conjunction with the thermal expansion difference between silicon and sapphire, and suggested to need a new model.
Deposition of Zinc Selenide by Atomic Layer Epitaxy for Multilayer X-Ray Optics
Authors: Shurtleff J.K. , Allred D.D. , Perkins R.T. , Thorne J.M. 
Published: March 2011

ABSTRACTThin film deposition techniques currently being used to produce multilayer x-ray optics (MXOs) have difficulty producing smooth, uniform multilayers with d-spacings less than about twelve angstroms. We are investigating atomic layer epitaxy (ALE) as an alternative to these techniques.ALE is a chemical vapor deposition technique which deposits an atomic layer of material during each cycle of the deposition process. The thickness of a film deposited by ALE depends only on the number of cycles. Multilayers deposited by ALE should be smooth and uniform with precise d-spacings which makes ALE an excellent technique for producing multilayer x-ray optics.We have designed and built an ALE system and we have used this system to deposit ZnSe using diethyl zinc and hydrogen selenide.
Spatial Light Modulator Using A CDS Thin Film Photocapacitor
Authors: Reichman Joseph 
Published: March 2011

ABSTRACTA brief summary is given of the characterization of an optically addressed Spatial Light Modulator (SLM) that uses a thin film of CdS as the hhotosensor and a liquid crystal as the electro-optic material. The required ghdark impedance of the CdS thin film is achieved by a depletion region created by surface acceptor states. Analysis of the SLM complex impedance as a function of frequency and illumination indicates that the voltage switching is due to the reduction in impedance with illumination caused by the increased capacitance of the CdS thin film. The impedance measurements as well as photoluminescence data were consistent with an acceptor surface state model accounting for the depletion region of the CdS thin fim. Additionally the SLM is shown to exhibit photoelectrochemical cell characteristics such as dark rectification, and a photocurrent and photovoltage proportional to the illumination intensity. The SLM performance characteristics of good resolution and sensitivity is attributed to the surface state induced depletion region.
U. S. Polycrystalline Thin Film Solar Cells Program
Authors: Ullal Harin S. , Zweibel Kenneth , Mitchell Richard L. 
Published: March 2011

ABSTRACTThe Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R&D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells and modules that meet the U.S. Department of Energy's long-term goals by achieving high efficiencies (15% - 20%), low-cost ($50/M2), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe2 and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The U.S. Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe2and CdTe with subcontracts to start in Spring 1990.
Annealing Behavior of The Photoluminescence Lines in CdTe and Znx Cd1−x Te Single Crystals
Authors: Gonzalez-Hernandez J. , Reyes-Mena A. , Lopez-Cruz Elias , Allred D.D. , Allred Worth P. 
Published: March 2011

ABSTRACTThe main lines in the photoluminescence spectra of Zn1Cd1−xTe single crystals grown by a modified Bridgman method in the compositional range of 0 ≤ X ≤ 0.25 have been identified. All crystals show only near-band-edge emission. To assist in the identification, various samples with different compositions were annealed under a Cd atmosphere. In the pure crystals, the prominent (A°,X) bound exciton line, as well as the doublet at longer wavelengths, disappear after the annealing. In contrast, the treatments do not change significantly the PL spectra of the mixed crystals.
Measurement of Interfacial Fracture Energy
Authors: Rosenfeld L. G. , Ritter J. E. , Lardner T. J. 
Published: March 2011

AbstractThe contact stresses resulting from indentation of a compliant coating on a rigid substrate cause debond cracks to initiate and propagate along the interface. The indentation debonding behavior of four polymer coatings on glass substrates is investigated. A model is developed for calculating interfacial fracture energy based on data of indenter load vs. debond crack size. Based on the experimental observations and the data for the four coating systems, the limitations of the model are discussed.
Spreading of Liquid Droplets on Cylindrical Surfaces: Accurate Determination of Contact Angle.
Authors: Daniel Wagner H. , Wiesel E. , Gallis H. E. 
Published: March 2011

AbstractThe wetting of cylindrical monofilaments by liquid polymers is a problem of much scientific and technological importance. In particular, the characterization of the physicochemical nature of interfaces is a key problem in the field of advanced fibrous composites. The macroscopic regime contact angle, which reflects the energetics of wetting at the solid-liquid interface, is difficult to measure by usual methods in the case of very thin cylindrical fibers.In the present article a numerical method is proposed for the calculation of macroscopic regime contact angles from the shape of a liquid droplet spread onto a cylindrical monofilament. This method, which builds on earlier theoretical treatments by Yamaki and Katayama [1], and Carroll [2], very much improve the accuracy of the contact angle obtained. Experimental results with high-strength carbon, para-aramid, and glass fibers, are presented to demonstrate the high degree of accuracy of the method proposed.
Silicon-Based Coatings on Niobium Metal
Authors: Stupik P. D. , Jervis T. R. , Nastasi M. , Donovan M. M. , Barron A. R. 
Published: March 2011

AbstractSilicon coatings on niobium substrates were subjected to thermal, ion beam and laser mixing, and the effectiveness of the different methods for the synthesis of graded interfaces was compared. The resulting metal/silicon interfaces were characterized by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and Rutherford backscattering (RBS).
Solid State Reactions in Mechanically Deformed Composites in the Ni-Zr and the Ni-Ti Systems
Authors: White B. E. , Patt M. E. , Cotts E. J. 
Published: March 2011

AbstractDifferential scanning calorimetry and x-ray diffraction analysis were utilized to monitor solid state reactions in mechanically deformed Ni/Ti multilayered composites. Solid state reactions at temperatures less than = 650 K result in the formation of a highly disordered phase which is apparently amorphous.The subsequent nucleation and growth at higher temperatures of intermetallic compounds from the amorphous phase is examined. The relatively small thickness of amorphous material (less than 100 Å) which can be grown by solid state reaction in our Ni/Ti samples, combined with the indication that a disordered interface such as that produced by mechanical deformation facilitates these reactions in the Ni-Ti system, may provide some explanation for the relatively high degree of success experienced in the production of amorphous Ni- Ti by means of ball milling. Comparisons are made to results obtained in the Ni-Zr system.
The Effect of Weak Interface on Transverse Properties of a Ceramic Matrix Composite
Authors: Shimansky R. A. , Hahn H. T. , Salamon N. J. 
Published: March 2011

AbstractExperimental studies conducted at the NASA Lewis Research Center on silicon carbide reaction-bonded silicon nitride composite system (SiC/RBSN) led to a significant observation regarding their unidirectional tensile properties. It was found that transverse stiffness and strength were much lower than those predicted from existing analytical models based on good interfacial bonding. Since the composite system was designed to have weakened interfaces to improve toughness, it was believed that these weakened interfaces were responsible for the decrease in transverse properties.To support this claim, a two dimensional finite element analysis was performed for a transverse representative volume element. Specifically, the effect of fiber/matrix displacement compatibility at the interface was studied under both tensile and compressive transverse loadings. Interface debonding was represented active gap elements connecting the fiber and matrix.The analyses show that the transverse tensile strength and stiffness are best predicted when a debonded interface is assumed for the composite. In fact, the measured properties can be predicted by simply replacing the fibers by voids. Thus, the following two conclusions are drawn from the present study: (1) little or no interfacial bonding exists in the SiC/RBSN composite; (2) an elastic analysis can predict the transverse stiffness and strength.
The Influence of Interfacial Modification on Tensile Strength of Gr/Al Composites
Authors: He Cheng , Zhang Guoding , Wu Renjie 
Published: March 2011

AbstractVarying the composition of the matrix alloy was a useful technique for tailoring the interfacial structure of MMC. In this paper, the influence of different interfacial states on the tensile strength of Gr/Al composites were investigated. Three aluminum alloys, pure Al, Al-Ti alloy (Ti oversaturated) and LY12 (an Al-Cu-Mg alloy) were chosen as the matrix materials. The results showed that the composites with Al-Ti matrix had excellent tensile properties, even after heat-treatment at 600°C, while with LY12 matrix exhibited poor properties compared with pure Al matrix. Microanalysis revealed that the interfacial structures of the composites with the above matrices were different. In addition, an initial study of mechanism of these matrix effects on the properties of the composites was also carried out.
Surface Forces and Adhesion Between Dissimilar Materials Measured in Various Environments
Authors: Smith Douglas T. , Horn Roger G. 
Published: March 2011

AbstractThe Israelachvili surface force apparatus has been used extensively over the past decade to make detailed measurements of surface forces and adhesion between very smooth solids in various liquid and vapor environments. Most of those measurements have been made with mica surfaces, but we have recently developed a method of preparing smooth silica surfaces for use in place of the mica. The silica surfaces adhere in dry and humid atmospheres, but do not adhere when immersed in water.The use of a second material not only broadens the scope of the Israelachvili technique, but also enables studies of forces and adhesion between dissimilar materials. In this work, we present the results of measurements of adhesion in air and forces in aqueous solution between two silica surfaces; we also report preliminary results of the adhesion between a mica surface and a silica surface.
An Investigation on Copper Red Glazes from Jingdezhen of the Ming and Qing Dynasties
Authors: Guozhen Li , Zeyong Liu , Yengyi Guo 
Published: March 2011

AbstractCopper red glazes made at the pottery center of Jingdezhen during the Ming and Qing dynasties are one of the most famous and precious porcelain products of China. They were based on earlier technology developed in the Tong-guan kiln in Tang dynasty and on the Ru and Jun wares of the Song dynasty. The earliest copper red glazes appeared as early as the late Yuan dynasty. The dazzlingly beautiful altar red and ruby red products were created at Jingdezhen in the Yongle and Xuande periods of the Ming dynasty. Other copper reds created at Jingdezhen were the Longyao red of the Kangxi period and the imitation Jun, flambe amd others of Yongzhen and Qianlong periods of the Qing dynasty. Chinese copper red glazes have been held in high regard throughout the world, and many have wondered at their complex and sophisticated technology. Through analysis, we unlock some of the technical secrets of these famous wares in order that more people may appreciate the technical excellence underlying the visual appearances of these wares and that these glazes may be replicated better by contemporary ceramic factories in Jingdezhen.Seven examples of Jingdezhen copper red glazes were analyzed by scanning electron microscopy, x-ray diffraction, refiring tests and microprobe analysis to determine the compositions, microstructures and firing temperatures.
Archaeometallurgy: Evidence of a Paradigm Shift?
Authors: Goodway Martha 
Published: March 2011

Abtract:Practitioners of archaeological and historical metallurgy have begun to identify their discipline by a new term: “archaeometallurgy.” Tracing the roots of this discipline shows that up to about 1980 the focus of study was on the technical examination of metal objects and determining site plans of metallurgical installations. Essentially it was a study of ancient metals of interest to historians of art or of technology. The focus then shifted to other materials and their archaeological contexts, processing byproducts such as slag, matte, furnace linings and furnace bottoms, crucibles, molds, cupels and tuyeres which are often more abundant on sites than metal. Thus the field of study has been enlarged beyond metallurgy to an interdisciplinary undertaking of materials science, archaeology, and material culture. Simultaneously with this shift in focus came the application of newly-developed instrumentation which supported a parallel shift in methodology from one emphasizing chemical analysis and microstructure to one of materials charactexrization, emphasising properties and performance.
Fine Metalwork from the Roman Cemetery at Stansted Airport, Essex Tinning and High Tin Alloys
Authors: Northover J. Peter , Brooks Howard , Lister Jan , Lloyd-Morgan Glenys 
Published: March 2011

AbstractThe early Roman cemetery discovered during the construction of London's third airport at Stansted contains the richest Roman burials discovered in Britain this century. The grave goods included a quantity of fine metalwork which forms te subject of this paper. The construction, alloys and finish of the pieces are described and discussed. Tin-plating and niello inlays are identified and described as is the analysis of corroded lead-tin solders and pewter. The manufacture of a high-tin bronze mirror is also discussed.
A Modular Approach to Microwave Applicator Design
Authors: Senise José T. 
Published: March 2011

ABSTRACTWhenever possible, the modular approach to microwave applicator design presents several advantages, both economical and operational, particularly in countries where high-power microwave generators are not manufactured on a commercial scale. In this paper, examples are shown of industrial applicators of simple, modular design, for the processing of liquid and solid materials, coupled to generators built with domestic microwave oven components.
Fiberoptic Sensor for Minimally-Perturbing Measurement of Electric Fields in High Power Microwave Environments
Authors: Sun M. H. , Wickersheim K. A. , Kamal A. , Kolbeck W. R. 
Published: March 2011

SummaryRecently a small, minimally-perturbing, isotropic, and easy-to-use fiberoptic microwave E-field probe has been developed. This probe senses microwave energy by measuring the Joule heating of a susceptor material. It consists of two Luxtron Fluoroptic sensors. One measures the temperature of the susceptor formed as a thin-walled spherical shell, the other measures the temperature of the air around the susceptor so that any ambient temperature change can be subtracted. The differential temperature (δT) obtained between the two sensors is directly related to the microwave E-field strength or the power density corresponding to that field strength at the probe.