bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single-Line Profile Analysis of Superplastically Deformed Aluminium Alloys
Authors: Bowen A. W. 
Published: March 2019

Superplastic deformation involves the controlled processing of materials in order to produce extensive deformation, the longest recorded elongation being nearly 5000%. Components of very complex shape can be formed in this way, thus offering substantial savings over the use of conventional manufacturing routes. Typically, these savings can be 50% in cost (through reduced man-hours required for component manufacture, from improved structural efficiency and from reduced material costs) and 25% in weight (through more efficient use of materials and the reduced requirement for joints and fasteners).The success of the superplastic process will depend, in large part, on achieving an adequate balance between the deformation input and the relief of work hardening by thermally activated relaxation processes. An attempt has therefore been made to establish whether the residual strain in superplastically deformed materials is related to deformation, parameters, and if so, to interpret this strain data in terms of the mechanisms of superplasticity.
Determination of Wear Metals in Oil by X-Ray Spectrometry
Authors: Liu Ya-Wen , Harding A.R. , Leyden D.E. 
Published: March 2019

AbstractTrace elements in oil may be determined by adsorption of the oil sample onto maguesium oxide followed by thermal degradation of the organic material. The resulting powder is easily pressed into a pellet suitable for X-ray spectrometric analysis. The lower limit of detection depends upon the trace impurities in the MgO and is a few parts per million for most elements determined.
Studies of X Rays Induced by Charged Particles
Authors: Duggan Jerome L. , William L. Beck  , Albrecht Larry , Munz Lee , Spaulding James D. 
Published: March 2019

Characteristic x rays have been produced for a variety of samples by bombardment with protons in the energy range from 75 keV to 5 MeV. The experiments were performed with two accelerators. For the low-energy studies (less than 150 keV), a Cockcroft-Walton accelerator was used. The higher-energy studies were done with a 5 MV Van de Graaff. The x rays were measured with high-resolution Si(Li) and Ge(Li) detectors. Yields for the cross section of characteristic K- and L-shell ionizations were measured for titanium, vanadium, chromium, manganeses iron, cobalt, nickel, copper, silver, gold, bismuth, and uranium. The experimental cross-sections have been compared to the theoretical predictions of the Born approximation for an interaction of this type.Trace element analysis by 4-MeV proton bombardment of samples in the 10-12 gm range has also been performed. Some comments with regard to analysis with these sensitivities will be made.
Proposed Flash X-Ray System for X-Ray Diffraction With Submicrosecond Exposure Time
Authors: Charbonnier Francis M. 
Published: March 2019

X-ray diffraction studies have generally used low current, low voltage X-ray tubes (e.g., 50 mA, 50 kV). Consequently, exposure times ranging from seconds to hours have been required, limiting X-ray diffraction techniques to the study of essentially static situations. Using such an X-ray source with a very high speed detector, R. E. Green was able to reduce the exposure time for laue patterns of aluminum crystals to a minimum of 0.003 sec. Nanosecond exposure and pulse timing are required for certain events, e.g., X-ray diffraction study of material under shock compression. Q. Johnson achieved this by using a low voltage, very high current flash X-ray source (approximately 50kV, 50kA, 30 nsec). However, such a system is difficult to build and to synchronize, and is not commercially available.Published X-ray yield data, particularly the recent work of J. W. Motz, indicate that both continuum and characteristic X-ray yields increase rapidly with electron energy, reaching a maximum for an electron energy ranging from 150 keV for titanium to 300 keV for copper to nearly 1 MeV for molybdenum.To take advantage of this property, a 300 kVp, 30 nsec pulse, 5 nsec jitter flash X-ray system has been built which appears to meet the intensity and timing requirements for single pulse laue or Bragg diffraction studies. System design, calculated output and initial tests are represented.
On-Line Process Control Compositional Analysis of Aluminum Films Containing a Low Percentage of Copper
Authors: Glade G. H. , Matthews J. M. , Titcomb F. R. 
Published: March 2019

Aluminum film conducting stripes are widely used for semiconductor device interconnection networks. The addition of a low percentage of copper significantly increases their life. Composition must be controlled to maintain product quality.The paper discusses various methods used to analyze the copper composition in the aluminum films, and adaptation of one of these methods for process control application. A portable instrument designed for field use was adapted for use as an on-line instrument.
Soft X-Ray Valance State Effects in Conductors
Authors: Holliday J. E. 
Published: March 2019

Investigation of the NiLIIIband at various excitation voltages and the use of Ni and Ti thin films in the path of the NiLII,IIIand TiLII,IIIradiation, has shown that with proper electrode geometry and using target voltages of about 4 kv the effect of self absorption on emission edge shift and band shape is negligible for these elements. However, the LII/LIIIintensity ratio of titanium is strongly effected by self absorption, but it is not effected for nickel and iron by self absorption.A survey of several investigators’ soft x-ray band spectra from alloys and conducting compounds showed that the observed band changes were related to the electronegativity difference of the combining elements or the ionic character of the band. Peaks appearing on the low energy side of transition metal bands when combined with 2nd period elements appear to be a cross transition between the 2s or 2p band of the non-metal and inner level of the metal.
A Versatile Vacuum Scahhihg Double Crystal Spectrometer for Soft X-Ray Absorption Edge Studies
Authors: Bhalla A.S. , White E.W. 
Published: March 2019

Studies of the fine structure of absorption edges in the soft x-ray region are becoming increasingly important as a tool for materials characterization. Examples of application includes determination of chemical state of elements, bonding and band structure studies. Intensity and resolving power of the x-ray spectrometer are important experimental considerations. As a rule adjustment of instrumental parameters, such as collimation, to give increased intensity adversely affect resolving power. Optimization of intensity and resolving power must therefore he achieved.A newly designed double crystal spectrometer has been constructed for high-resolution absorption edge studies in the wavelength region of 5Ǻ to 70Ǻ.The entire system is enclosed in a vacuum chamber ion pumped to the 10-7torr range. The second crystal motion is obtained by means of an ULTRADEX 360-sided polygon and sine arm that is automatically step-scanned. The spectrometer functions equally well in the (l, + l) and (l, - l) orientation and as a precise single crystal spectrometer.
Electron Spectroscopy for Studying Chemical Bonding
Authors: Ragnar Nordberg  
Published: March 2019

The results reviewed in this article were obtained by means of the ESCA technique at the Institute of Physics, University of Uppsala, Uppsala, Sweden and at the Department of Physics, Vanderbilt University, Nashville, Tennessee, USA.The ESCA technique is basically the study of induced emission of photo and Auger electrons from a sample irradiated with x-rays. If the incident radiation is monochromatic (e.g. an x-ray emission line) the spectrum of these electrons gives precise information about the energy states of the electrons in the sample. To extract this information, high resolution electron spectroscopy is necessary. Instruments for such spectroscopy have therefore been extensively developed during the last decade.
Correlation of Residual Stress Level and Fatigue Damage in B. C. C. Metals
Authors: Koves G 
Published: March 2019

The development of materials with optimum fatigue characteristics hinges on a better understanding of the fatigue mechanism ( i .e ., fatigue crack nucleation and propagation) under specific loading conditions. A correlation was established between the residual macroscopic stress level--as measured by x-ray diffraction analysis, the fatigue damage in the form of slip-band formation and intensification, and the fatigue life at various applied stress levels of pure iron and low-carbon steel.Residual stresses were measured by an automated diffractometer technique (Fe 211 Kα reflection, Cr radiation) and computer calculation of both macroscopic (line shift) and microscopic (line broadening) stresses . Surface fatigue damage was observed by optical microscopy.
Mass Absorption Coefficient Measurements Using Thin Films
Authors: Lublin P. , Cukor P. , Jaworowski R. J. 
Published: March 2019

For quantitative electron probe analysis, the raw intensity ratios must be corrected to take into account deviations due to absorption, fluoresecnce and electron beam penetration. The major correction is usually the absorption correction, so that for best results, accurate mass absorption coefficients are required. Many tables of absorption coefficients are calculated by interpolation or extrapolation from available measured values, and therefore new measurements are required for increased reliability. The region which requires the most attention for present-day probe analysis is the 2 to 10 Å range.Thin foils of the lighter metals are available for mass absorption coefficient measurements, but heavy metal foils, which must be extremely thin, are not obtainable, A method has been developed to prepare thin films of heavy metals on a suitable substrate by pyrolytic decomposition of metal organic compounds.
Computer searching of the Jcpds powder Diffraction File
Authors: Dismore Faden F. 
Published: March 2019

Jackson Laboratory is using computer searching of the powder diffraction file on an “in-house” IBM 365/65 computer for about 1000 searches per year. This paper will discuss our experiences with the search program.A Philips Automatic Powder Diffractometer (APD), modified to communicate with an XDS Sigma 5 computer collects the data. A program in the Sigma 5 provides both hard copy output and a computer deck of punched cards for input to the JCPDS search program.The JCPDS search program is indispensable for our large volume of samples . The majority of these samples are corrosion products which generally have “broad peaks, and frequently, preferred orientation.
Direct Quantative Determination of Silica by X-ray Diffraction on Pvc Membrane Filters
Authors: Henslee W. W. , Guerra R. E. 
Published: March 2019

Exposure of industrial workers to respirable crystalline silica is receiving considerable attention at present from industrial laboratories and regulatory agencies. Analytical methodology for rapid and accurate determinations of microgram quantities of silica is necessary. The X-ray diffraction method which has been recommended by NIOSH requires lengthy sample preparation.An X-ray diffraction method has been developed for the quantitative analysis of α-quartz directly on polyvinyl chloride filters in the microgram range. The minimum detectable concentration of α-quartz is approximately 2μg/cm2. This represents a sensitivity comparable to that claimed using the Bumsted method. The necessity of ashing the filter and depositing the residue on silver membrane filters, as well as the addition of a standard, is avoided. This minimizes handling and alteration of the sample.
Powder-Pattern: A System of Programs for Processing and Interpreting Powder Diffraction Data
Authors: Pyrros Nikos P. , Hubbard Camden R. 
Published: March 2019

The production of standard x-ray diffraction patterns at NBS imposes special requirements in the data processing of powder patterns. The patterns should be complete and have an overall accuracy of better than 0.01 degree two theta. To ensure completeness all the observable peaks should be indexed. To make certain that the sample is a pure phase, weak peaks have to be identified as well.The indexing of all the peaks implies that the cell constants must be known and there should be a good agreement between all the calculated and observed peak positions. In practice this is achieved by a least-squares refinement of the unit cell parameters. This serves as a test of the assumed unit cell and also as an interpretation of the observed peaks. Finally, an attempt is made to identify the space group. This step also requires the identification of weak peaks. The agreement of a known space group with the observed reflections further confirms the purity of the sample.
Computer-Aided Qualitative X-Ray Powder Diffraction Phase Analysis
Authors: Goehner Raymond P. , Garbauskas Mary F. 
Published: March 2019

AbstractThis paper describes a set of interactive computer programs written in FORTRAN IV and implemented on a POP 11/34 equipped with RLO-2 ten Mbyte discs and an RSX-11M operating system to assist in x-ray diffraction phase analysis. The packing of the data base will be described along with the various interactive programs that access it. The search/match package is designed more as a set of aids for the diffractionist rather than as a single totally automated search/match program, the procedure adapted by many of the xray diffraction (XRD) equipment manufacturers. The approach taken allows the analyst to direct the analysis procedure by utilizing different search/match programs or specifying various options within a given program.
Preparation and Certification of Standard Reference Materials to be Used in the Determination of Retained Austenite in Steels
Authors: Hicho George E. , Eaton Earl E. 
Published: March 2019

In the steel hardening process, steel is heated to a temperature where a face-centered-cubic solid phase called austenite is formed. After a stabilization period, the steel is quenched into a medium which transforms the austenite into a metastable, body-centered-tetragonal solid phase called martensite. On occasion the austenite is not entirely transformed into martensite and some austenite remains. This untransformed (retained) austenite is sometimes detrimental to the finished product, and often there are requirements as to the amount of retained austenite permitted In the finished product.X-ray diffraction procedures (XRD) are normally used to determine the amount of retained austenite and this paper describes the preparation and characterization of the Standard Reference Materials used to calibrate x-ray diffraction units.
Profile Fitting for Quantitative Analysis in X-Ray Powder Diffraction
Authors: Schreiner Walter N. , Jenkins Ron 
Published: March 2019

Quantitative phase analysis by powder diffractometry requires accurate measurement of the integrated intensities of the diffracted, lines. When lines are isolated and on simple backgrounds, count integration techniques work very well. However, when one or more lines overlap the line of interest, or a complex background is present, profile fitting techniques are required in order to eliminate interferences.Profile fitting involves choosing a mathematical model to represent the expected profile shapes. Experience has shown that the profile shapes obtained with a parafocusing powder diffractometer are not easily described and many models have been tried with varying degrees of success. Generally the more free parameters allowed In the model the ‘setter the fits, although, aesthetically one would like to keep the number of free parameters to a minimum.
Direct Determination of Stress in a Thin Film Deposited on a Single-Crystal Substrate from an X-Ray Topographic Image
Authors: Berry Wayne S. 
Published: March 2019

AbstractX-ray topography is one of several methods used by the semiconductor industry to measure stress of thin films deposited on single crystal substrates. A procedure to determine stress values directly from the X-ray topographic image by measuring the separation of the Kα1-Kα2 X-ray peaks is reviewed. Although less sensitive than the single-crystal technique, it has been found applicable to monitor stress levels in films such as CVD silicon nitride on silicon wafers. This technique may also be used to quantify the plastic deformation of wafers that is induced by semiconductor processes.
Energy Resolution Measurements of Mercuric Iodide Detectors Using a Cooled Fet Preamplifier
Authors: Ames Lawrence , Drummond William , Iwanczyk Jan , Dabrowski Andrzej 
Published: March 2019

AbstractThe performance of a room temperature mercuric iodide X-ray detector was investigated as a function of detector bias, amplifier time constant, and detector temperature. A Mn Kα line of 200 eV FWHM was obtained by using low noise electronics developed for Si(Li) detectors, including a cooled input PET. Measurements of the detector's resolution at various X-ray energies result in a Fano factor of 0.20.
Application of XRF to Measure Strontium in Human Bone In Vivo
Authors: Wielopolski L. , Vartsky D. , Yasumura S. , Cohn S.H. 
Published: March 2019

Strontium appears in the earth's crust at a concentration of about 400 ppm and in sea water about 8,1 ppm. Consequently, all living forms have evolved in the presence of this alkaline earth and have incorporated it in their tissues. The exact role of Sr in the human body remains ambiguous (1), even though Sr has been extensively studied with reference to the radiation hazard from 90Sr (2).Metabolic behavior of Sr, in some aspects, is similar to that of Ca (3), but substantial dissimilarities between these two are also well recognized (1,4). It has been suggested that Sr stimulates the formation of bone matrix. At higher concentrations, however, it interferes with calcification mechanism of the bone matrix (5).
Theoretical Calculation of Background in X-Ray Spectrometry for the Determination of Some Heavy Trace Elements
Authors: Gruffat Jean-Jacques 
Published: March 2019

AbstractThe Kulenkampff-Kramers formula giving the spectral distribution of the continuum as a function of wavelength allows a correct calculation of background under the peak. It is only necessary to measure two backgrounds, one on each side of the peak, The true background under the peak is given by multiplying them by adequate coefficients and adding them up. This method has been applied to the determination of low amounts of Ce, La, Ba and Cs in geological samples.
Systematic Computation of Scattering Corrections with the Code Shape
Authors: Fernandez J.E. , Molinari V.G. 
Published: March 2019

AbstractThe recently developed code SHAPE allows the build-up of EDXRF spectra for collimated and monochromatic excitation. In this work the code is applied to investigate the Importance of the scattering corrections to the more intense XRF characteristic lines from low and medium Z elements. Results are given graphically for pure elements from Z=11 (Na) to Z=42 (Mo). Heavier element lines from a multi-component geological sample, where light matrix amplifies the influence of scattering, are studied.
X-Ray Studies of Chromium Nitride (CrxNy) Thin Films Deposited by Reactive Magnetron Sputtering
Authors: Charbonnier M. , Romand M. , Roche A. , Terrat J.P. 
Published: March 2019

AbstractChromium nitride hard coatings have been prepared by a plasma process by varying nitrogen partial pressure. The crystallographic structure of these samples has been investigated by XRD and their chemical composition and stoichiometry by Low Energy Electron Induced x-ray Spectrometry (LEEIXS).
Instrumentation for Total Reflection Fluorescent X-Ray Spectrometry
Authors: Utaka Tadashi , Arai Tomoya 
Published: March 2019

AbstractThis article describes the instrumentation for a total reflection fluorescent x-ray spectrometer. The reflecting intensity and the angular divergence were studied with respect to various kinds of monochromators. Using silicon wafers, the angular divergence effect of the incident beam, surface roughness influences and the smoothing of background x-ray intensity for the improvement of the lower limit of detection were investigated.
A High Resolution Portable XRF HgI2 Spectrometer for Field Screening of Hazardous Metal Wastes
Authors: Bernick M. , Berry P. F. , Voots G. R. , Prince G. , Ashe J. B. , Patel J. , Gupta P. 
Published: March 2019

AbstractThe use of a field portable XRF analyzer incorporating a semiconductor, mercuric iodide, energy dispersive spectrometer is described with emphasis on the benefits of high resolution x-ray detection for rapid screening of hazardous metallic wastes. Results are presented of “in-situ” and “prepared sample” soil measurement for different sites to show the potential of Fundamental Parameter analysis to obtain acceptable quality data with minimum calibration effort, obviating the need for site-specific standards.
The Application of Linear Polarized X-rays After Bragg Reflection for X-ray Fluorescence Analysis
Authors: Wobrauschek Peter , Aiginger Hannes 
Published: March 2019

AbstractPolarized x-rays are used to excite samples of any kind and shape to emit characteristic radiation. In the appropriate geometry, where source-sample-ED detector are in any orthogonal position to each other, the exciting poLarized x-rays will be practically not scattered from sample and substrate into the detector. This reduces the background considerably and hence improves the lower limits of detection. The production of intensive polarized x-rays is done by using a single crystal-where Bragg reflection occurs at an angle 2 θ = 90° instead of amorphous low Z scatterers. The result is a linear polarized and monochromatic beam. The use of curved crystals instead of plane single crystals further increases the intensity of the exciting radiation. The lower limits of detection attainable with the recently constructed compact polarizer device are in the sub ppm range or in absolute amounts around 150 pg for medium Z elements.
High Temperature X-ray Diffraction Studies of the Defluorination Reactions of Chukhrovite, Falphite and Ralstonite
Authors: Wilson Robert L. , Mu Jacob , Bradford James L. 
Published: March 2019

Current commercial processes for the production of wet-process phosphoric acid involve the dissolution of phosphate rock and separation of insoluble solids by filtration. Calcium is removed by the addition of H2SO4, to precipitate CaSO4•2H2O. Other metallic impurities are removed by extraction or precipitation.In a new process. Lower grade phosphate ore can be digested with recycled phosphoric acid. If the raw acid contains a fairly high concentration of Mg, it may be enriched in fluoride ion.
Determination of the Crystal System of a Neodymium-Iron-Boron Alloy by X-ray Diffraction
Authors: Wims Andrew M. , Johnson Jack L. 
Published: March 2019

The MAGNEQUENCH process for making high energy product (> 10 MG•Oe) permanent magnet alloys of Nd2Fe14B has been described. To advance further the commercial application of these alloys, a better understanding of the microstructure and crystallography is required.The crystal system and unit cell parameters can be determined from the angular positions of the x-ray diffraction peaks, provided the data have been collected with a 2θ accuracy error of <0,02°. Computer based methods are available for handling the large number of calculations required. This paper describes the experimental problems encountered and solved during the determination of the cell parameters for this alloy.