bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of Recrystallization Texture Formation in Cold Rolled Iron Sheets with X-Ray Diffraction Techniques
Authors: Matsuo M. , Hayami S. , Nagashima S. 
Published: March 2019

AbstractThe possibility that primary recrystallization textures are influenced by local inhomogeneities of deformation induced in the regions of grain boundaries has been confirmed by comparing the cold rolling and the annealing textures of polycrystalline pure irons which were different in the grain size prior to cold rolling. Analyses were made for the effects of deformation on crystals, namely storage of lattice strain and orientation spread, with application of X-ray diffraction techniques, in order to elucidate the role of in homogeneities of deformation on recrystallization texture formation. Apparent correspondence was found between the orientation dependence of stored strain energy and the textural change on recrystallization. This is a scribed to oriented nucleation in high energy blocks, in the case of originally large-grain material in which the effects of inhomogeneities of deformation are small. But discrepancies arise on this basis in originally small - grain material in which the effects of inhomogeneities of deformation are thought to be considerable. The discrepancy is inferred to arise as an effect of local inhomogeneities of deformation, from the change in the trend of rotational orientation spreads from, a stable orientation and the extent of development of potential nuclei of recrystallization at high energy blocks in the orientation spreads. The change is considered to give rise to the variation in amount of microstrain distribution, which is expressed in recovery characteristics of lattice strains and in the dependence of microstrains on the column length as analyzed by following the procedure of Warren-Averbach.
Binding of Aliphatic Dihydroxy Compounds to Collagen with X-ray Diffraction Evidence for the Vander Waals Bond
Authors: Shaw E. H. 
Published: March 2019

AbstractPrevious work presented by the author at these conferences has been summarized by G.N. Ramachandran in “Treatise on Collagen I , 177-8”. Epitactic crystallization of amides and diols in the collagen lattice of formalinized rat tail tendon, with equatorial expansion of the collagen lattice, was used to visualize the core diameter of each coil in the triple spiral at 7A and the vertical repeat of the hydrogen-bonding unit at 5.2A. Expansion of the non - formalinized collagen lattice has been observed as high as 20.1A when 1, 4-trans-(bisamino-methyl) - cyclo-hexane was inserted between the hexagonal array of protein spirals in the collagen lattice, the length of the inserted molecule being 13A. With dimensions based on Fisher - Hirschfelder - Taylor atomic models, with maximum extension of the dihydroxy compounds, the a. parameter of the expanded collagen would be expected to increase from 16.5A in the case of glycol to 20.6A in the case of 1, 5 - pentanediol, but actually the parameter decreases from 18.3A in the case of glycol to 16.2A in the case of 1, 5 - pentanediol. The larger figure in the case of glycol is explained by its hydrogen bonded dimerization. 1,3 propanediol fits in to the collagen lattice as its extended form. In the case of the other compounds, the chains are folded and fit together with Vander Waals bonding, and produce progressively smaller parameters for the a axis in collagen. In this nonaqueous equilibrium the non - formalinized collagen core diameter averages 7.7A ±0.2 and the spacing of hydrogen bond contacts along the collagen fiber axis is 4.8 ±0.2A.
Simultaneous Determination of I0 and I for X-ray Absorption Spectroscopy Using a Monitored Beam Technique*
Authors: Hurst C. V. , Glen G. L. 
Published: March 2019

AbstractIn x-ray absorption spectroscopy, the accurate determination of the incident intensity (I0) has long been a difficult problem. Several techniques have been used to collect I0 data, but none have simultaneously obtained both I0 and I (transmitted intensity after absorption). The new technique described herein permits simultaneous determination of I0 and I utilizing a dual detector monitoring of the x-ray beam. With the sample removed, an intensity relationship between the two detectors, arranged in tandem, can be obtained. Knowing this relationship permits determination of I0 in the second detector during an experiment. The effects of voltage, current, and gas flow variations on this relationship are discussed, and an experiment is described where an absorption spectrum is obtained over an emission peak of the x-ray tube target material. The results of the experiment using two methods of obtaining I0 are compared.
Structural Analysis of X-ray Diffraction Peaks of Thin Film Gallium Arsenide
Authors: Charlson E. J. , Hu D. H. , Farukhi M. R. 
Published: March 2019

AbstractA least-squares polynomial approximation of the Warren-Averbach Fourier coefficients line broadening analysis has shown flash-evaporated GaAs films to be characterized by De(lll) ≤ 400 Å and >εL2<½ ⋍ 0.002. Though twinning is the dominant faulting mechanism, a considerable amount of single and double deformation stacking faults are also present. Growth under a partial pressure of arsenic and tin has enhanced crystallite size by a factor of four.
Molecular X-ray Spectra of Sulfur and Chlorine Bearing Substances
Authors: Andermann G. , Whitehead H. C. 
Published: March 2019

AbstractThe interpretation and use of x-ray photon spectra of substances containing second row elements has utilized a number of theoretical models. These models may be divided into three basic categories, namely, the isolated atom model, various molecular models, and a number of solid state models, it is the purpose of this paper to examine critically the validity and limitations of molecular models for interpreting published x-ray photon spectra and spectra obtained by this group on chlorine and sulfur bearing substances.Chlorine and sulfur bearing substances were chosen for at least three important reasons. First, a great deal of published experimental data already exists on the Kα, Kβ, and L2, 3 transitions of these substances. Second, motivated in part by the long standing controversy concerning possible 3d orbital participation in the bonding of second row elements, there are extensive quantum mechanical calculations for ions containing sulfur and chlorine via simple molecular orbital concepts. Thirdj the availability of accurate photoelectron spectroscopic data on these substances now permits a detailed quantitative comparison of x-ray photon transitions with quantum mechanical calculations.Detailed evaluation along these lines indicates that for many substances the theoretically calculated energy values are frequently within a few electron volts (or less) of the experimentally observed energies. This study, therefore, tends to substantiate a viewpoint suggested by some recently; namely, that for many substances the starting point in interpreting most of the basic features of soft x-ray spectra should be based upon molecular bonding approaches.
New Features and Advanced Applications of Siroquant: A Personal Computer XRD Full Profile Quantitative Analysis Software Package
Authors: Taylor J.C. , Clapp R.A. 
Published: March 2019

AbstractSIROQUANT is a suite of personal ccmputer programs which runs on an IBM-compatible 386 or 486 personal computer, and gives phase quantification of mineral samples hy Rietveld refinement using the full XRD profile. Eight phases can be quantified in a mineral with the 640 K RAM version and 11 in the EM version.New features have been added since the original description was written (J.C. Taylor, Powder Diffraction, 6, 2, 1991) including calculations of amorphous percentages using spiked samples, particle size calculations, use of “measured” as well as calculated patterns as standards, pre-programmed refinement “Stages” with different variables in each stage, and improved menus.Some advanced applications of the system using these new features are described.
Effect of Powder Sample Granularity on Fluorescent Intensity and on Thermal Parameters in X-Ray Diffraction Rietveld Analysis
Authors: Sparks C. J. , Kumar R. , Specht E. D. , Zschack P. , Ice G. E. , Shiraishi T. , Hisatsune K. 
Published: March 2019

AbstractThe effect of sample granularity on diffracted x-ray intensity was evaluated by measuring the 2θ dependence of x-ray fluorescence from various samples. Measurements were made in the symmetric geometry on samples ranging from single crystals to highly absorbing coarse powders. A characteristic shape for the absorption correction was observed. A demonstration of the sensitivity of Rietveld refined site occupation parameters is made on CuAu and Cu50Au44Ni6 alloys refined with and without granularity corrections. These alloys provide a good example of the effect of granularity due to their large linear x-ray absorption coefficients. Sample granularity and refined thermal parameters obtained from the Rietveld analysis were found to be correlated. Without a granularity correction, the refined thermal parameters are too low and can actually become negative in an attempt to compensate for granularity, A general shape for granularity correction can be included in refinement procedures. If no granularity correction is included, data should be restricted to above 30° 2θ, and thermal parameters should be ignored unless extreme precautions are taken to produce <5 (μm particles and high packing densities.
X-Ray Reflection, A New Tool for Investigating Layered Structures and Interfaces
Authors: Lengeler Bruno 
Published: March 2019

AbstractAt grazing incidence all X-ray techniques become surface sensitive. Far below the angle of total reflection the X-rays penetrate only 20 to 70 Å into condensed matter. X-ray reflectivity measurements give the density and the thickness of layers on substrates and the roughness of external and internal interfaces. The diffuse scattering in the vicinity of the specular reflection gives, besides the interface roughness, also the height-height correlation of the surface. From the angular dependence of the fluorescence intensity, emitted as a consequence of X-ray absorption, the depth profile of the absorbing species can be deduced. Artificial periodic multilayers give rise to Bragg reflexes and to standing X-ray wave fields, the angular dependence of which give the distribution of atomic species in the periodic stack. A number of examples illustrate the possibilities of the technique.
Defining Residual Stresses in Thin Film Structures
Authors: Noyan I. C. 
Published: March 2019

AbstractResidual stresses are found in the majority of multilayer thin film structures used in modem technology. The measurement and modeling of such stress fields and the elucidation of their effects on structural reliability and device operation has been a “growth area” in the literature, with contributions from authors in various scientific and engineering disciplines.In this paper a review of the definitions of the residual stresses used by the authors in the various disciplines is presented and the mechanisms by which residual stresses may form in thin film systems is discussed.
X-Ray Study on the Fatigue Fracture Surface of Austempered Ductile Cast Iron
Authors: Kishi Yoichi , Hirose Yukio , Yajima Zenjiro , Tanaka Keisuke 
Published: March 2019

Austempered ductile cast iron (ADI) lias microstructures that consist of martensite and of retained austenite. ADI has very toughness compared with cast iron heat-treated differently. The retained austenite near fracture surfaces transforms to martensite when fracture occurs.In the present study, X-ray fraetography is applied to fatigue fracture surfaces of ADI. The fatigue tests were carried out on compact tension (CT) specimens. The volume fraction of retained austenite was measured quantitatively and the line broadening of X-ray diffraction profiles was measured on and beneath fatigue fracture surfaces. The depth of the plastic zone left on fracture surfaces was evaluated from line broadening. The results are discussed on the basis of fracture mechanics.
A Study on the Misalignment of a Soller-Slit Pack in a Parallel-Beam Geometry Diffractometer
Authors: Depero L.E. , Zocchi M. , Bonzi P. 
Published: March 2019

AbstractThe dependence of a peak diffraction angle on the positioning of the diffracted-beam Soller-slit pack was observed and studied by discussing the determining factors. In particular, the misalignment angle between the Soller pack and the counter axis is recognized as a key factor and experiments were performed for giving a quantitative basis to this statement. An important consequence of the results of these experiments and related profile analysis is the suggestion of designing parallel-beam diffractometers with the possibility of checking and changing the position of the diffracted-beam Soller-slit packs in order to optimize the performance of the instrument.
The Structure of Nanocrystalline Iron and Tungsten Powders Prepared by High-Energy Ball Milling
Authors: Wagner C.N.J. , Yang E. , Boldrick M.S. 
Published: March 2019

AbstractNanocrystalline powders of Fe and W were prepared by mechanical working in a highenergy Spex 8000 mixer/mill. The diffraction patterns were recorded with Co Kα radiation and the line profiles were subjected to a Fourier analysis. The size 〈D〉 of the coherently diffracting domains (x-ray particle size) and the root-mean square strains 〈ε2L〉1/2 were determined with the Warren-Averbach method. In addition, the integral breadths were evaluated and corrected for instrumental broadening assuming Cauchy line profiles. In order to separate particle size and strains, the corrected breadths β(s) = βcosθ/λ were plotted as a function of s = 2sinθ/λ, i.e., β(s) =(1/D) + 2ε s, where D = 〈D2/〈D〉 and ε is a strain averaged over the domain size D.X-ray fluorescence analysis indicated that the W powders contained an iron and chromium contamination due to the abrasion of the stainless steel balls reaching a value of 24 at% Fe+Cr after 20h of milling. Since W is elastically isotropic, all available (hkl) reflections can be used in the Warren-Averbach and line breaddi analyses. After 20 h of milling, the W powder exhibited a particle size 〈D〉 = 35 Å and a strain 〈ε2〉1/2 = 0.52% at L = 30 Å. The integral breadths yielded the particle size D1 = 70 Å and the strain ε = 0.38%. in the case of Fe powder, also milled for 20 h, the (110) - (220) pair of reflections was used to calculate the particle size and strains. The Fourier analysis yielded the values 〈D〉 = 105 Å and 〈ε2〉1/2 = 0.59% at L = 30 Å. The corresponding integral breadth values are D1 = 280 Å and ε1 = 0.7%. The sum of the particle size Fourier coefficients is equal to the integral breadth particle size D1 = 125 Å, which is very close to value 〈D〉 = 105 Å indicating that the particle or domain sizes have a very narrow size distribution.
The On-Stream X-Ray Analysis of Slurries for Process Control
Authors: Engelbrecht Johann P. , de Villiers Johan P.R. , de Bruyn Stefan W. 
Published: March 2019

AbstractAn integrated XRD-XRF system for the on-stream analysis of slurries was configured to the requirements of industry for process control. The slurry-handling system includes a multiplexer, header tank, de-aerator and a windowless sample presenter. The XRD part of the system is composed of a molybdenum anode X-ray tube, a pyrolytic graphite primarybeam monochromator, a vertical fixed-geometry goniometer, and a simultaneous detector system. The X-ray beam is transmitted through the slurry curtain so that the diffracted intensities are measured in the forward diffracted mode. The energy-dispersive XRF spectrometer measures the reflected fluorescence intensities. Examples and data from the onstream XRD analysis of fluorspar and apatite are presented. Mention is made of the application of an integrated XRD-XRF system in the heavy-minerals and base-metal industries.
Phase Microidentification from Selected Area Electron Diffraction (SAED) and Energy Dispersive Spectroscopy (EDS) Data
Authors: Macicek Josef 
Published: March 2019

AbstractTwo-dimensional geometry information contained in SAED spot patterns augmented with EDS elemental data is employed in a computerized phase identification of microcrystalline particles. The initial chemistry screening of a laboratory managed database using the 'bitmap' concept is followed by a geometry search/match treating of the spot patterns as planar sections through the reciprocal lattice of a candidate phase. The identification is selective, fast, and yields to a complete automatization,
Performance Of Room-Temperature X-Ray Detectors Made From Mercuric Iodide (HgI2) Platelets
Authors: Barton J. B. , Dabrowski A. J. , Iwanczyk J. S. , Kusmiss J. H. , Ricker G. , Vallerga J. , Warren A. , Squillante M. R. , Lis S. , Entine G. 
Published: March 2019

AbstractCurrent developments in the recently introduced method of HgI2 crystal platelet growth by polymer assisted vapor transport are described. Crystal parameters are evaluated by making electrical measurements on x-ray detectors fabricated from HgI2 platelets, Selection for detector fabrication is on the basis of size and apparent crystalline perfection. Detectors have been fabricated with active areas averaging 2 to 3 mm2 and thicknesses ranging from 20 to 400 µm. Values of electron mobility and mobility-lifetime product measured for HgI2 platelet material are among the highest ever observed for HgI2.The combination of low leakage current and good electron transport makes HgI2 platelets suitable for room-temperature x-ray spectrometry. An energy resolution of 370 eV (FWHM) for the 5.9 KeV Mn Kα line has been obtained, and representative low-energy x-ray fluorescence spectra are presented.
IDENT - A Versatile Microfile-Based System for Fast Interactive XRPD Phase Analysis
Authors: Jobst Barbara A. , Göbel Herbert E. 
Published: March 2019

AbstractA minicomputer program system for phase Identifications in x-ray powder diffraction is described. The routines written in FORTRAN comprise the users’ special purpose standard-file management (creation of microfiles from the complete JCPDS-data base or own standards, as well as utility routines for corrections, supplements and bookkeeping) and the measured data processing, including raw data acceptance, data reduction by two selectable peak-search routines (trendoriented or 2nd derivative) and an exhaustive search/match procedure through selected microfiles. The data reduction and analysis programs have manifold graphical displays allowing manual interference. In one run up to five phases can be matched. The weight portion of every phase is estimated, using I/I (corundum)- values, Hie whole analysis (in automatic operation) consumes about 1 or 2 minutes of the processor time on a pdp 11/34 minicomputer. This matches well to the data collection times accessible for fast powder diffraction systems /I/.
A Guinier Diffractometer with a Scanning Position Sensitive Detector
Authors: Göbel Herbert E. 
Published: March 2019

AbstractA strictly focussing Guinier diffractometer using a linear position-sensitive proportional counter (PSPC) to detect the diffracted x-rays is described. The data collection time for a complete pattern can so be reduced to minutes Instead of hours as it used to be in conventional film- or counter-Guinier systems. The PSPC collects all diffracted x-rays over several degrees of 2 Theta in parallel and composes the full pattern by a continuous scan over the whole 2 Theta range. This principle was described in Adv. In X-Ray Anal. Vol. 22, 255 ff and 24, 123 ff. for Bragg-Brentano diffractometers.
Space Shuttle Main Engine Hydrogen Pump Impeller Residual Stress Measurements Using Pars (Portable Apparatus for Measurement of Residual Stress)
Authors: Pardue E. B. S. , Mathis M. V. , Hendricks R. W. , Stangeland E. M. 
Published: March 2019

X-ray residual stress analysis was performed on four space shuttle hydrogen pump impellers made from Ti-5Al-2,5Sn alloy. Five locations on the outer rim, near the vanes, were measured on each impeller, identified as #1, #2,#3, and #4. Impellers #1 and #4 were test-fired impellers, impeller #2 was a new impeller that had been spin tested, and impeller #3 was a new impeller that had not teen spin tested. The measurement locations on these impellers corresponded to areas of critical stress importance. The purpose of the measurements was to compare the stresses at these locations as a function of impeller processing variables. A description of the Impellers, the test parameters and procedures, stress analysis results, and a technical discussion of these results are presented in this report.A description of the Impellers, the test parameters and procedures, stress analysis results, and a technical discussion of these results are presented in this report.
Fourier- Filtering Techniques for the Analysis of High- Resolution Pulsed Neutron Powder Diffraction Data
Authors: Richardson James W. , Faber John 
Published: March 2019

AbstractRietveld profile refinements using high-resolution pulsed neutron povder diffraction data, collected at IPNS, often reveal broad intensity contributions from sources other than the crystalline materials being studied. Such non-crystalline intensity hampers standard Rietveld refinement, and its removal and/or identification is imperative for successful refinement of the crystalline structure. A Fourier-filtering technique allows removal of the non-crystalline scattering contributions to the overall scattering pattern and yields information about the noncrystalline material. In particular, Fourier transformation of residual intensities not accounted for by the Rietveld procedure results in a real-space correlation function similar to a radial distribution function (RDF). From the inverse Fourier transform of the correlation function a Fourier-filtered fit to the diffuse scattering is obtained. This mathematical technique was applied to data for crystalline quartz, amorphous silica, and to a simulated diffraction pattern for a mixture of the two phases.
Neutron Powder Diffraction Applications at the University of Missouri Research Reactor
Authors: Yelon W. B. , Ross F. K. , Berliner R. 
Published: March 2019

AbstractA neutron powder diffractometer at the University of Missouri Research Reactor (MURR) uses a linear position sensitive detector (PSD) which has increased both resolution and data acquisition rates. Rietveld analysis works as well with this system as with more conventional single and multi- Soller slit detector systems. This analysis has been successfully applied to problems involving more than 75 parameters and 1200 reflections and a future instrument upgrade should allow analyses which involve 100-150 parameters. A special advantage of the PSD instrument is that it needs only small (1-2 gm) samples to achieve high statistical accuracy.
Quantitative X-Ray Diffraction Analysis of Calcium Sulfates and Quartz in Wet-Process Phosphoric Acid Filter Cakes
Authors: Waerstad Kjell R. 
Published: March 2019

AbstractA quantitative X-ray diffraction method has been developed for rapid determination of the crystalline phases present in by-product filter cakes from wet-process phosphoric acid manufacture. A new technique to reduce preferred orientation of the crystallites by removing the top layer of the X-ray samples with adhesive tape is described, statistical analysis of synthetic sample mixtures of CaS04.2H2O, CaSO4 · 0.5H20, CaSo4, and α-Si02 indicates that the calcium sulfate phases present in typical filter cakes can be determined with an accuracy of about 3% at the 95% confidence level; quartz can be determined at about 14%. The method has been applied to the analysis of 10 filter-cake samples from an experimental hemihydrate plant. The results are in good agreement with data from X-ray fluorescence and chemical analyses