bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Analysis of Dust Samples From Occupational Environments Using Computer-Automated X-Ray Diffraction
Authors: Abell M. T. , Dollberg D. D. , Crable J. V.
Published: March 2019

The goal of the occupational health professions is ”… to assure so far as possible every working man and woman in the Nation safe and healthful working conditions and to preserve our human resources” (Occupational Safety and Health Act, PL91-596). When the health of workers is threatened by chemical agents in the air, occupational health chemistry has a role to play. Analyses of workplace air are performed by the thousands each year by industry and by state and federal agencies. In the federal government, these analyses, as well as occupational health work in general, are performed by three agencies: the National Institute for Occupational Safety and Health (NIOSH, DHHS), which does occupational health research; the Occupational Safety and Health Administration (OSHA, DOL), which enforces safety and health standards in the general workplace; and the Mine Safety and Health Administration (MSHA, DOL), which enforces similar standards in mining operations.
An Approach to the Automation of a Multifunction X-Ray Diffraction Laboratory
Authors: Nunes T. L.
Published: March 2019

A variety of x-ray diffractometers supporting stress measurements, routine phase identification, precision lattice parameter determinations, crystallite size estimates, and high temperature studies have been interfaced to a central minicomputer. The unique attributes of each instrument have been retained while the central minicomputer provides a common control format, data storage area, and analysis program library. Two movable desk top computers provide limited backup for the minicomputer, and serve as test beds for technique development.
Integral Type, Position-Sensitive Proportional Chamber with Multiplexer Readout System for X-Ray Diffraction Experiments
Authors: Mochiki Koh-ichi , Hasegawa Ken-ichi , Sekiguchi Akira , Yoshioka Yasuo
Published: March 2019

Recently intense X-ray sources have been used in diffraction experiments on stress analysis, dynamical structure analysis, and so on. Since in these experiments one-dimensional position-sensitive X-ray detectors are very useful to reduce the measuring time, various kinds of X-ray detectors and processing systems have been developed. These detectors may be divided into two groups, the pulse type and the integral type. The pulse type employing either the charge division method, or the delay line method, processes each signal produced by an incident X-ray photon. To achieve a precise measurement, a sufficient gas gain and a relatively long processing time are needed. Therefore, the maximum counting rate depends on both detector characteristics and a signal processing time. On the other hand, the integral type, such as self-scanning photodiode array detectors (1, 2) periodically processes the charges produced by X-rays in each pixel. The total maximum counting rate of the detector is the sum of the maximum counting rate of each pixel and is higher than that of the pulse type.
On-Stream Analysis of Float Process Slurries by XRF
Authors: Ereiser J. , Frank G. , Guy J.W. , Litchinsky D.
Published: March 2019

An on-stream XRF analysis system for monitoring the concentrations of the elements in float process slurries is described. The system consists of multiple XRF stations monitored by a central computer. The stations utilize high resolution Si(Li) detectors and radioisotope x-ray sources for stability and for good separation of adjacent elements such as Cu and Zn. Results obtained from an on-stream slurry analysis of Copper and Lead Tails and Copper and Lead Concentrates are presented and these are compared to assay lab results.
Applicability of Pixe and XRF to Fast Drill Core Analysis in Air
Authors: Carlsson Lars-Eric , Akselsson K. Roland
Published: March 2019

The properties of particle-induced X-ray emission, PIXE, and secondary target mode X-ray fluorescence, XRF, applied to the analysis of unprepared drill cores in open air have been evaluated. Typical detection limits for elements heavier than Mg have been determined for a PIXE-system with an external 2.55 MeV proton beam and for an XRF-system with Ti, Mo and Tb secondary targets. These two systems were found to have similar detection limits for most elements in a typical geological sample. The heterogeneous composition of drill cores prevents the performance of accurate matrix corrections, though calculations using fundamental parameters show that in the PIXE analysis of elements heavier than Ca, these corrections are much less sensitive to variations in the matrix composition than in the XRF analysis.
Glass and Glass Raw Materials Analysis using a Philips PW1600 Wavelength Dispersive X-Ray Spectrometer
Authors: Jones D. R. , Bowling G. D.
Published: March 2019

The Inorganic Analytical Laboratory of Owens-Corning Fiberglas is routinely using a Philips PW1600 x-ray spectrometer for the analysis of glass and glass raw materials. The spectrometer is equipped with 11 fixed channels, two scanning channels, and an energy dispersive detector. Operation of the spectrometer and data compilation is accomplished using a Digital Equipment Corp. PDP11/34 computer. The x-ray is controlled by an RSX-11M operating system, and the Philips “Alphas” software package is used to process data using the Lucas- Tooth Pyne (LP), Lachance-Traill (LT), or Rasberry-Heinrich (RH) correction models.
Monte Carlo Simulation of Self-Absorption Effects in Elemental XRF Analysis of Atmospheric Particulates Collected on Filters
Authors: Hawthorne A. R. , Gardner R. P. , Dzubay T. G.
Published: March 2019

Monte Carlo simulation is used to determine the effects of selfabsorption for the low energy X-rays of light elements in the size range front 1 to 20 μm. Calculations are performed for a wide angle Fe-55 radioisotope-excited energy dispersive XRF system. Results are obtained for sulfur attenuation in thin layers, long cylinders, and spheres composed of various matrix materials. The enhancement effect is also treated for the transition region between thin and thick layer samples as well as in spheres of various sizes. Results are also comrpared to fixed angle analytical models.
Filter Absorption Correction for X-Ray Fluorescence Analysis of Aerosol Loaded Filters
Authors: Van Grieken R. E. , Adams F. C.
Published: March 2019

In the case of X-ray fluorescence analysis of aerosol loaded filters, the X-ray absorption effect Is due to particulate matter absorption and to filter material absorption. The latter contribution is of a predominant importance in many practical cases. It can be calculated from the ratio of the X-ray intensities measured from the front and back side of the filters. The sandwich geometry obtained by folding the filters in two with the loaded side inwards during the measurement renders the filter material absorption correction much simpler and often more accurate, and offers distinct additional advantages.
Application of the Least-Squares Method to the Analysis of XRF Spectral Intensities from Atmospheric Particulates Collected on Filters
Authors: Arinc F. , Gardner R. P. , Wielopolski L. , Stiles A. R.
Published: March 2019

The least-squares method with complete component library spectra is applied to the quantitative analysis of X-ray fluorescence spectral intensities. An approach is outlined for application to the general case of thick homogeneous samples at high counting rates, A simplified approach can be taken with the more specific case represented, by atmospheric particulates collected on filters. The details and sample results of this approach for this specific case are given for an energy dispersive X-ray fluorescence analyzer. The results indicate that the least-squares method as developed and applied here is valid and should prove generally useful to X-ray analysts.
Absorption Corrections for X-Ray Fluorescence Analysis of Environmental Samples
Authors: Bazan F. , Bonner N. A.
Published: March 2019

The discovery of a very simple and useful relationship between the absorption coefficient of a particular element and the ratio of incoherent to coherent scattering by the sample containing the element is discussed. By measuring the absorption coefficients for a few elements in a few samples, absorption coefficients for many elements in an entire set of similar samples can be obtained.
Automatic Time Sequence Filter Sampling of Aerosols for Rapid Multi-Element Analysis by Proton-Induced X-Ray Emission
Authors: Nelson J.W. , Jensen B. , Desaedeleer G.G. , Akselsson K.R. , Winchester J.W.
Published: March 2019

An automatic time sequence filter sampler has been developed for atmospheric aerosol particle sampling of ambient air and subsequent analysis for elemental composition using the proton, beam of a Van de Graaff accelerator. Some features of the operation of the sampler are given, the retention of particles by the filter material are discussed, examples of the type of data obtained are presented, and some approaches to the numerical analysis of data for environmental interpretation are considered. Lines for further development and improvement in this type of sampler are indicated.
Orientation of Back Reflection Laue Photographs: A Semi-Automated Approach
Authors: Goehner R. P.
Published: March 2019

Computer simulation of back reflection Laue patterns now provides the means to plot Laue patterns for any crystal system in any orientation. This capability makes it possible to determine, rapidly and accurately, the orientation of single crystals and large grains in polycrystalline materials even in cases where little or no symmetry is displayed in the Laue photograph. A set of standard Laue patterns is first simulated to cover the stereographic triangle of the crystal being studied. The Laue photograph obtained from the crystal, or grain, is compared with the set of simulated Laue patterns. The pattern most similar to the photograph is used to determine the (HKL) values of three Laue spots. The (HKL) values of these spots and half their angular separations from the x-ray beam, along with the lattice constants, are used by a computer program to calculate the (HKL) value of the crystallographic plane perpendicular to the x-ray beam. A simulated Laue pattern can now be obtained in exactly the same orientation and it can be drawn directly to the scale of the Laue photograph. Thus the validity of the orientation can be easily verified by direct comparison. The (HKL) value of the crystallographic plane perpendicular to the x-ray beam can also be used to plot a stereographic projection of the crystal poles. Therefore, the complete orientation of the crystal can be determined.
Diffracted Beam Monochromators for Powder Diffractometry
Authors: Proctor E. M. , Furnas T. C. , Loranger W. F.
Published: March 2019

The efficiency and effectiveness of diffracted beam x-ray monochromators used in powder diffractometry have been described in so many ways that much confusion exists regarding their true performance. Although significant improvements in signal to noise ratios are readily achievable, and they offer a solution to the sample fluorescence problem, it is not without sacrifice to total intensity or achievable resolution or both. This paper discusses and describes a series of comparisons between filtered direct beam, LiF and graphite monochromators.

These comparisons include the considerations necessary for the appropriate selection of diffracted beam slit system, the effect of vertical divergence as a function of two theta for singly bent crystals, the effects of a non-uniformity of contribution over the length of the crystal, and the geometry necessary for the singly bent and doubly bent crystals. The total intensity and the resolution of LiF and graphite are discussed, in particular, it is noted that the performance of monochromators with randomly oriented samples is quite different than their performance with samples showing preferred orientation or grain effects.

A new diffracted beam monochromator based on the Rowland focusing geometry is described.
X-Ray Investigation of a 2H-3C Phase-Transformation in Silicon Carbide Single Crystals
Authors: Krishna P. , Marshall R. C.
Published: March 2019

This paper reports the results of a detailed X-ray diffraction study of a new phase-transformation observed in SiC crystals grown by a vapour-liquid-solid mechanism involving the hydrogen-reduction of methyltrichlorosilane. The 10.ℓ reciprocal lattice rows of these crystals, as recorded on X-ray diffraction photographs, reveal sharp reflections corresponding to the hexagonal close-packed 2H (ABAB….) structure and sometimes also corresponding to the cubic close-packed 3C (ABCABC…) structure. These reflections are invariably connected by a diffuse but continuous streak whose intensity is a measure of the random faulting on the basal planes. The crystals were needle shaped and the structure sometimes varied along their length.

Several crystals were annealed in an inert atmosphere at progressively higher temperatures and their 10.ℓ reciprocal lattice row re-examined to determine the annealing behaviour as well as possible structural transformations. For a number of dark green needles having a faulted 2H structure the 2H reflections disappeared around 1400° C and the 10.ℓ reciprocal lattice row revealed only a continuous streak with increased intensity around positions for 3C reflections. On further heating the structure went over to a strongly faulted 3C. Around 1600°C the appearance of a 6H structure became discernible while highly diffuse 30 reflections still persisted. The reversible part of the transformations, if any, could not be observed. Some of the structures were, however, found to be much more stable and did not transform even up to 1650° C.

The above results, in particular the discovery of a 2H-3C phase-transformation around 1400°C, throw fresh light on the thermodynamic stability of the different SiC types. The mechanism of the 2H-3C transformation, the possible influence of faults and impurities and the thermal stability of various SiC structures are discussed on the basis of the experimental results stated above.
Developments in Analytical Diffraction Using Isotopic X-Ray Sources
Authors: Toothacker W. S. , Preuss L. E.
Published: March 2019

Lobov et al., in Leningrad, and workers at this laboratory have been working on the idea of using x rays from radioactive sources for x ray diffraction analysis. The Russians have been using iron-55 produced by the (n, Y) reaction in their work with a small focusing camera which operates in the back reflection region. We have been using iron-55 produced by the (p,n) reaction in conjunction with a small Debye-Scherrer camera. The preliminary work of this laboratory was reported at this conference two years ago. At that time a 13 mCi iron-55 source was used in a two inch diameter Debye-Scherrer camera to obtain x-ray diffraction patterns of LiF. The exposure times were of the order of 120 hours and the reflection from the 200 plane was about 3 degrees wide. Since that time a new and more intense source has been constructed at Oak Ridge National Laboratories. With the new source it was possible to produce LiF diffraction patterns of the same density and resolution as before in a period of less than ten hours.

The above mentioned diffraction patterns were made with the LiF powder placed in a 1.0 mm diameter glass capillary. After reduction of the glass capillary diameter to 0.5 mm and appropriate reduction of the collimator width, we were able to improve the resolution considerably with no accompanying reduction in line density. The LiF patterns obtained in this way required an exposure time of about 20 hours and the width of the reflection from the 200 plane has been reduced to about 1.5 degrees.

Hence we are able to report a reduction in exposure time from 116 hours to 20 hours and an increase in resolution by a factor of two over the data reported here two years ago. Thus the concept of using x rays from an isotope for powder diffraction has changed from a laboratory curiosity into a technique with practical possibilities. Both sources mentioned above were produced by the (p, n) reaction. The 135 mCi source had a specific activity of about 400 Ci/gm. Since iron-55 sources have been made with specific activities of about 1000 Ci/gm, a considerable decrease in exposure time could be accomplished by using such a source. The application to this work of a position sensitive proportional counter as developed by Semmler will also be discussed.
Application of Calculated Intensities for Reflection X-ray Topographs
Authors: Blish R. C.
Published: March 2019

This paper is an effort to quantify such variables as penetration depth, intensity, and defect contrast in reflection X-ray topographs. The analysis includes an appropriate combination of geometrical, polarization, absorption, and scattering factors. Quantitative measurements have been made for a variety of diffracting planes and-wavelengths on Si and Ge. The calculations also fit qualitatively (fluorescent screen intensity} with observations on Zn, ZnO, CdS, GaAs, GaP. Topographs from some or all of these materials will be shown to illustrate how these calculations can predict useful diffraction conditions.
Heavy Ion-Induced Characteristic X-Ray Generation as an Analytical Probe
Authors: Cairns J. A. , Holloway D. F. , Nelson R. S.
Published: March 2019

Increasing attention is currently focused on the generation of characteristic x-ray by proton irradiation. This has the advantage of yielding “clean” x-ray- i. e. free from background brerasstrahlung radiation, from even the lightest elements. The disadvantage is that the yields are naturally much lower than those produced by electrons of the same energy. A recent study has extended characteristic x-ray production to a variety of heavy ions and has shown that the cross- sections for the production of clean x-rays are often higher , by as much as several orders of magnitude, than those produced by protons of the same energy. In addition, there has emerged a further advantage, viz. the ability of specially chosen heavy ions to excite characteristic x-ray from a particular element in a selective manner. Since heavy ions penetrate only a few hundred Angstroms in to most solids, the phenomenon can be used as the basis of a technique for the examination of surface deposits, or to measure depth distributions of impurities. For example, Kr ions can be used t o determine the range distribution of antimony which had been implanted in to silicon at 100 keV. The antimony concentration was determined as a function of ∼ 150 Å steps, and was found to exhibit a maximum concentration of ∼ 1 part in 103of silicon at 450 Å below the surface, falling to zero concentration at ∼2000 Å a depth. In the past, in order to obtain the required degree of sensitivity, such range determinations have relied on radio active tracer techniques.

An entirely new type of proportional counter has been developed during the course of these studies. This instrument, because of its special construction, can be positioned very close to targets in non-dispersive studies, so as to collect the highest possible fraction of emitted x-ray. It incorporates a replaceable anode unit, together with a built- in miniature head amplifier, and exhibits extremely good performance, particularly for ultra-soft x-ray. In addition, rotation of a dial on the end of the counter body allows alteration of the active gas volume during operation, and so permits tuning into x-rays of a particular energy.
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

The 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

Previous 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

In 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

A 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

The 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

SIROQUANT 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

The 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

At 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

Residual 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

The 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

Nanocrystalline 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.
An X-Ray Diffraction Study of Compacted Metal Powders
Authors: Killen P. D. , Raftery N. A. , Hay D.G.
Published: March 2019

In this study electrolytic copper powder and atomised high purity iron powders of various size, fractions were consolidated to comparable densities by two very different processes (quasistatic pressing and dynamic, or shook wave, compaction). The resulting pairs of compacts had densities of approximately 0.96 of the theoretical density. These specimens were analysed by X-ray diffraction in order to determine the effect of particle size on the response to compaction.
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

An 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

Two-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

Current 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.
Techniques for the Preparation of Lithium Tetraborate Fused Single and Multielement Standards
Authors: Mahan Kent I. , Leyden Donald E.
Published: March 2019

Since first introduced by Claisse, twenty-five years ago, borate fusions have been used in XRF analysis of a wide variety of materials because fusion eliminates many of the problems associated with particle size and matrix effects encountered in the analysis of powders. Geological and environmental materials such as rocks, ores, sediments, slags, air-borne particulates, etc., lend themselves nicely to lithium or sodium tetraborate or lithium metaborate fusion because the inherent presence of silica in these materials stabilizes the resultant glass from crystallization.
A Resin-Loaded Paper X-Ray Fluorescence Method for Determining Uranium in Phosphate Materials.
Authors: Haynes Benjamin W. , Zabronsky Jerome , Neylan David L.
Published: March 2019

The assessment of the environmental impact of mining and mineral processing is an important part of the research program of the U.S.D.I. Bureau of Mines. Under the Minerals Environmental Technology program, the Avondale Research Center evaluated the accessory minerals and elements, associated with the mining, beneficiation, and processing of phosphate rock in the central Florida phosphate district. In support of this project, a resinloaded paper (RLP) X-ray fluorescence (XRF) method was developed for determining uranium in these processing and waste materials.
Accurate PIXE Analysis of Thin Samples, Aerosol Loaded Filters and Surface Layers of Thick Samples
Authors: Wätjen U. , Richter F.-W.
Published: March 2019

Particle induced X-ray emission (PIXE) analysis is well established as a multi-element, non-destructive technique to measure the trace element content of thin samples (≤ 1 mg/cm2). The wide range of its analytical applications was shown in numerous reports at the 2nd International PIXE Conference in Lund. For thin sample analysis routinely done at the Marburg PIXE facility, we calibrated our spectrometer empirically at proton energies of 2 and 4 MeV using two separate sets of calibration standards, one purchased from MicroMatter Co., the other prepared by precipitate exchange. Both sets of standards were checked by AAS and CMP. K-shell ionization cross sections, calculated from our measured x-ray yields, agree very well with recent literature values, and will be reported elsewhere.
Energy Dispersive Analysis of Actinides, Lanthanides, and Other Elements in Soil and Sediment Samples
Authors: Laurer G. R. , Furfaro J. , Carlos M. , Lei W. , Ballad R. , Kneip T. J.
Published: March 2019

A model is under development at this laboratory to predict the mobilization of Th from an estimated 20,000 metric ton deposit, in place and weathering as long as 80 million years on the Morro do Ferro, a hill on the Pacos de Caldas plateau in Minas Gerais, Brazil. The significance of this deposit lies in the marked similarities, chemically, between Th and Pu with reference to the problem of Pu waste management from the nuclear fuel cycle. One of the objectives of this program is to determine the elemental composition of the Morro do Ferro soil and its relationship to the mobilization of Th from the deposit. X-ray fluorescence is used for the analysis of Th, U, Ba, La, Ce, Pr, Nd, Sm, Dy, Eu, Gd, Yb, Hf , Fe, Zr, N b , Mo and Pb. This paper describes the XRF system and methodology used for the determinations and presents the results of 72 core, soil and sediment sample analyses for the above 18 elements. Analyses of three United States Geological Survey (USGS) rock standards are also presented.
IDENT - A Versatile Microfile-Based System for Fast Interactive XRPD Phase Analysis
Authors: Jobst Barbara A. , Göbel Herbert E.
Published: March 2019

A 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

A 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

Rietveld 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

A 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

A 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