bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Design and Performance of the Dual-Function Spectrodiffractometer and Automatic Programmer
Authors: Ashby W. D. , Buhrke V. E. , Patser G. V. 
Published: March 2019

AbstractA new concept in a dual-function diffractometer-spectrometer has been developed. With this new concept, it is unnecessary to disassemble any part of the instrument when changing from diffraction to air-helium spectroscopic applications and vice versa. Therefore, the alignment of the instrument is not disturbed and changeover is accomplished in a matter of seconds.The diffractoraeter is the standard biplane diffractometer, having an angular range of −55 to +164° 20 and a full 360° ω. Without interfering with the entire angular range of the diffractometer, the spectrometer section allows an angular range to 154° 2θ, This uninterrupted freedom of angular motion for both functions is accomplished by the design concept of using different frames of reference for the 0-180° 2θ plane of the diffractometer and the 0-180° 2θ plane of the spectrometer. In one case, the motion of 16 toward higher positive angles is counterclockwise and in the other case, it is clockwise. The frames of reference are displaced by 96°.The helium attachment for low-atomic-mimber elements ensures complete replacement of the air with helium in a flushing time of 15 sec. After changing samples, the helium atmosphere returns to equilibrium within 5 sec.A ten station programmer also has been developed, enabling one to automatically program oscillating scans and stepped scans of diffraction profiles as well as sequential emission analyses. The angular position is programmed in increments of 0.01° and is reproducible within 0.005°.During the sequential mode of operation, 20 is driven to the next position at a rate of 40 deg/min. In addition, stepping increments as small as 1/120° and scanning speeds of ⅛, ¼, ½, 1, and 2 deg/min are available. In all of the above modes of operation, data are collected and printed as a function of preset time, preset count, or angular position.In this paper, typical performance characteristics and applications are presented.
Experimental X-Ray Stress Analysis Procedures for Ultrahigh-Strength Materials
Authors: Woehrle H. R. , Reilly F. P. , Barkley W. J. , Jackman L. A. , Clough W. R. 
Published: March 2019

AbstractQuite recently there has been commercially developed a series of high-alloy steels, on new compositional bases, which possess 3 very desirable combination of unusually high strength, good ductility, and toughness even at comparatively low temperatures. At the same time, research with mechanical working procedures, combined with optimum heat-treat considerations, have produced with several older, more conventional steels, strength levels of high orders of magnitude. Each of the considered materials is capable of yield strengths approaching or exceeding 300,000 psi, corresponding to elastic strains of about 1%.This paper is concerned with the development and evaluation of workable X-ray stress analysis procedures to be employed to measure, with a good degree of accuracy, high elastic strains. The materials selected include maraging steels, ausformed steels, and cold-drawn A.I.S.I. 4340 steels.Of the various possible X-ray techniques which were considered, very satisfactory results were obtained by the use of the two-exposure method. A special fixture was designed and constructed to allow uniaxial straining of test specimens while in the X-ray unit. Imposed strains were measured directly by strain gauges mounted on tbe specimen. Simultaneously, strains were measured by the use of chromium radiation filtered with vanadium foil. The peak resolution obtained was very satisfactory with a peak to background ratio of approximately 4:1 for the {211–121} martensite doublet used to measure the shift in peak location between the normal and oblique exposures. Because of the widths of the peaks involved, it is impossible to precisely specify the angular position of a given peak by inspection of the usual recorded trace. A counting technique, combined with a least-squares curve-fitting procedure involving five points, was very satisfactory for precisely locating positions of maximum intensity, Superior results were obtained when a multiplicative correction factor proposed by Koistinen and Marburger was applied.
An Ultrahigh-Temperature, Single-Crystal Texture Camera Diffractometer*
Authors: Prickett Robert L. 
Published: March 2019

AbstractA single-crystal high-temperature X-ray camera has been built with permissible operating temperatures of 2500°C. The camera is constructed to rest upon a Siemens horizontal diffractometer and may be used with either an external electronic detector or with film. The sample is supported on an externally adjustable goniometer head and is heated from the back by an ion beam. Controlled oscillation allows rotation photographs to be obtained from the sample surface not touched by the ion stream. Temperature is controlled by a thermocouple supporting the sample, the thermocouple being an intrinsic part of the goniometer. As a design limit, zero and first order layer lines with iron Kα. radiation on specimens with lattice parameters of 2.6 Å or larger may be recorded. Copper, cobalt, and molybdenum radiation allow even greater latitude. Types of samples that may be studied include powder (pellet), single crystal, wire, or rod. The camera serves equally well for single-crystal, texture, or powder studies on refractory materials.
Diffraction Maxima Positions in Two Types of Liquid Organosilicon Compounds
Authors: Stammler M. , Bruenner R. , Orcutt D. 
Published: March 2019

AbstractA study of two homologous series of liquid oiganosilicates showed a position change of the diffraction maximum of the halo. The first series consisted of polymeric silicic acid esters of the general formula SinOn-1(OC2H5)2n+2 with the following arrangement, where n = 1,2,3,…For these compounds, an increase of the d-spacings was observed with increasing length of the –Si–O–Si– chain. The d-spacings observed require coiled molecules.The second series consisted of orthoesters of silicic acid with the general formula Si(OR)4, where R is the aliphatic hydrocarbon chain. Here, an increase of the d-spacings was observed with increasing number of carbon atoms in the hydrocarbon chain. The molecules have close to spherical symmetry. The hydrocarbon chains provide a very efficient shielding of the [SiO4] tetrahedra, so that only very little intermolecular interference occurs. A similar relation exists also for the refractive indices of these compounds which increase with increasing length of the –Si–O–Si– chain in Series 1 and with increasing number of carbon atoms in Series 2. A plot of silicon concentration vs. d-values or refractive index shows both minimum values for ethyl orthosilicate.D. B. Nash could show that for silicate glasses, the d-values increased with increasing SiO2 content. For liquid organosilicon compounds, not the silicon content but the size of the molecule (total number of atoms except hydrogen) is responsible for both the change of the d-values and the refractive indices. The size of the “ordered regions” in these liquids is related to the size of the molecules only. The interaction of molecules is minimized by the shielding effect of the organic groups,
Some Instrumental Considerations in the Automatic On-Stream Analysis of Pulps for Elemental Content
Authors: Moffat Walter G. , Carson Robert 
Published: March 2019

AbstractThis paper describes the detailed assembly of an X-ray automatic analyzer for the continuous estimation of elemental contents in flowing pulp streams as applied in a concentrator of the Northern Rhodesian Copperbelt. Arguments are given for the selection of electronic components, the programming of operations, mechanical movements, and other aspects concerned with the consecutive analysis of a number of pulp streams of widely different composition and elemental concentration. Details are given of a method of automatic compensation for pulp density and matrix variations using X-ray absorption.
Some Observations on X-Ray Emission as a Function of Accelerating Voltage in the Microprobe
Authors: Burk D. L. 
Published: March 2019

AbstractData are presented from several systems for which the emitted X-ray intensity goes through a maximum as accelerating voltage is increased. An attempt is made to systematize the data in terms of absorption, wavelength, and atomic number. A very simple model, analyzed graphically, is capable of displaying many of the features of the experimental data.
A Modification of the Scanning X-Ray Topographic Camera (Lang's Method)
Authors: Yoshimatsu Mitsuru , Shibata Atsushi , Kohra Kazutake 
Published: March 2019

AbstractA modification of the scanning X-ray topographic camera, is reported. The specimen and photoplate are traversed back and forth independently in two directions rather than in the same direction as in the case of Lang’s camera. The distortions of the photographs caused by geometrical arrangement can be eliminated through this construction so as to have a one-to-one correspondence. Examples of reflection photographs as well as transmission photographs are shown. Some of them are compared with those taken using Lang’s camera. The dislocation images in the reflection photographs show a good one-to-one correspondence to those in the transmission photographs. The broadening of the dislocation images in the traversing direction is discussed. The present camera is especially useful for the studies of lattice defects in the thick specimens because the reflection photographs can be easily taken.
An X-Ray Diffraction Study of the Phase Transformation Temperature of MnO
Authors: Gazzara Charles P. , Middleton R. M. 
Published: March 2019

AbstractX-Ray diffraction measurements of MnO confirm the hypothesis that the structural temperature and the magnetic transition temperature, or Néel temperature) are the same. The usefulness of X-ray diffraction intensity data of MnO, with respect to an atomic structural refinement problem involving α-Mn powders, is discussed. Lattice constant values of MnO are listed between 100 and 310°K
High-Intensity Rotating Anode X-Ray Tubes
Authors: Taylor A. 
Published: March 2019

AbstractDemountable rotating anode X-ray tubes with a 7½ kW power dissipation have been built for conventional diffraction work with powder cameras and equi-inclination Weissenberg goniometers, and for use with a tetrahedral press for studying crystalline matter at ultra-high pressures. The tubes employ a highly compact cooling and sealing arrangement on the rotating anode which enables four windows to be used with the focal spot close to the specimen. A rotational speed of 1750 rpm with a focal spot size of 10 × 1 mm enables the tubes to be operated at 250–275 mA at 30 kV DC or at 150 mA, 50 kV DC.
A Dual Counter X-Ray Analyzer for the Rapid Quantitative Analysis of Two-Phase Systems
Authors: Sanderson B. S. , MacCardle L. E. 
Published: March 2019

AbstractThe normal procedure for a quantitative measurement of two phases with an X-ray diffractoraeter is to scan or count the intensities of two diffraction peaks and then to calculate the ratio of the two phases using an appropriate equation. This paper will describe an improved method of quantitatively measuring two phases in a sample. The diffractometer, which was constructed by Philips Electronics Instruments, consists of two fixed scintillation counters mounted at the Seeman-Bohlin focusing positions for the two desired diffraction lines. Each counter is preceded by a lithium fluoride curved crystal monochromator. The output from each counter feeds to a separate sealer which can be arranged to gate both sealers at a preselected number of counts. At this point a tape printer prints out the counts for both sealers. These counts are then related to the proportions of each phase present by an appropriate equation. Most of the electronics are solid-state designs. This paper will describe the instrumentation and show how it can be used to measure rapidly and precisely the ratio of anatase to rutile in a titanium dioxide system. The savings in time over the conventional method can be as much as 100 to 1.
Determination of Electron Distribution and Bonding from Soft X-Ray Emission Spectroscopy
Authors: Holliday J. E. 
Published: March 2019

AbstractFrom measurements of the shift in wavelength with chemical combination, it appears there is very little transfer of charge between the metal and nonmetal atoms for the Group-IV transition-metal carbides and diborides. For Group-VI transition-metal carbides and beyond, there appears to be a definite transfer of charge from the carbon to the metal atom. The bonding in the Group-IV transitionmetal carbides is largely co valent, and metallic for the Group-IV transition-metal diborides. A comparison of shapes of emission bands with crystal structure indicates that, in general, NaCl-type structures have symmetrical peaks with narrow bandwidths compared to hexagonal structure, which have asymmetrical peaks, broad bandwidths, and long tails to the bottom of the bands.
X-Ray Techniques in the 1 to 400 Å Range
Authors: Sterk Andrew A. 
Published: March 2019

AbstractX-ray work in the 10 to 400 Å range usually requires, for maximum sensitivity, new methods of X-ray generation, analysis, and detection. A comparative survey includes X-ray generation by fluorescence, electron bombardment, and proton bombardment. Dispersive analysis with crystals and gratings is described. Finally, window less photoelectric multipliers are evaluated as X-ray detectors.Results show that typical efficiences range from 10−4 to 10−2 photons/electron or photons/proton, with the latter value as a practical upper limit. An efficiency of 8.5% has been measured for a KAP crystal covering the wavelength range up to 25 Å, while an original gold-plated grating lias a maximum measured efficiency of 20%. Counter efficiency may range from 1 to 50%, depending on wavelength. Total efficiency for a grating-type spectrometer in the 20 to 400 Å range has been measured to 2 × 105 photons/cm2-count.
On the Primary X-Ray Analyzer
Authors: Kimoto Shizuo , Sato Masayuki , Kamada Hitoshi , Ui Takuzi 
Published: March 2019

AbstractThe primary X-ray analyzer is used for nondestructive spectrochemical analysis of solid specimens. Accelerated electron beams bombard the specimen surface directly and generate primary X-rays which are measured in a vacuum spectrometer. The method of primary X-ray spectroscopy is superior to the fluorescence X-ray spectroscopy because (1) detectable sensitivity for such light elements as magnesium and aluminum is very high, and (2) the correction of the measured value for self-absorption of X-rays by the specimen itself is low. The performance of the instrument and applications are reported.
Applications of X-Ray Analysis to Environmental and Biomedical Studies
Authors: Gilfrich John V. 
Published: March 2019

AbstractRecent developments in x-ray spectroscopy have shown that this technique is a very powerful tool for the analysis of small quantities of material. A distinction must be made here between microanalysis -the analysis for elemental composition of a small total amount of material - and trace analysis - the analysis of bulk material for the presence of certain elements at very low concentrations. By the use of chemical separation, a problem in trace analysis can be converted into a microanalytical situation. A major improvement in trace analysis has been achieved by the use of ion-exchange resin loaded onto filter paper to collect the element(s) of interest from a solution of the original sample. The analysis of these concentrates or of particulate matter filtered out of polluted air or water can be optimized because the total mass of the sample is small and the background due to scattered prirmary radiation can be minimized.Much interest has become manifest recently in the use of solid-state detectors for energy dispersion x-ray analysis of samples of this type. The value of energy dispersion can be demonstrated by improved detection limits for samples containing only a few widely separated elements. However, resolution of state-of-the-art solid-state detectors is not adequate to separate the Kβ of one element from the Kα of the next higher atomic number among the transition metals. Thus the presence of a large number of immediate neighbor elements at widely different concentrations as in pollution samples suggests the need for crystal spectrometers.
Differential Photoionization Cross Section of Neon Subshells for the X-Ray Analysis by Photoelectron Spectrometry
Authors: Wuilleumier François 
Published: March 2019

AbstractThe new x-ray analysis method using photoeleetron spectrometry demands knowledge of differential photoionization cross sections of the subshells of the converter atoms used as intermediary between the x-ray spectrum and the photoelectron spectrum. These differential cross sections were determined for the most appropriate converter, the neon atom, in the energy range from 50 to 3000 eV. The total photoionization cross section was partitioned into contributions that arise from single ionization in the various subshells and from multiple processes. We present in tabular and graphical form: a) 1s, 2s and 2p total subshell cross sections; b) 1s, 2s and 2p differential cross sections at 54.73°; and c) ls, 2s and 2p differential cross sections at 90°. Accuracy is considered to be better than 3%, 7% and 5% at all energies for 1s, 2s and 2p cross sections, respectively.
An Energy Dispersive System for the Analysis of Trace Elements in Human Blood Serum
Authors: Ong P. S. , Lund P. K. , Litton C. E. , Mitchell B. A. 
Published: March 2019

AbstractA computerized systetn, consisting of a fluorescence x-ray source (Philips), an Si (Li) detector (Ortec), and a mini Computer (Xerox) is currentiy in operation at The University of Texas M. D. Anderson Hospital and Tumor Institute, Experimentel Pathology Section, for the analysis of trace elements in biological specimens. The elements of interest are Fe, Cu, and Zn for possible significance in the detection and study of cancer. The detection system is being used for comparatively routine analysis of these elements, which are present in blood serum in the ppM range. With appropriate sample preparation techniques, using 1 ml of serum, the limit of detectability for these elements is estimated to be 100 ppB (1 in 107). Further refinement is possible, and research in this direction continues.
X-Ray Energy Analysis of Particulate Matter on Filter Paper
Authors: Wood Warren G. , Mathiesen James M. , Mgebroff John S. 
Published: March 2019

AbstractThe rapid, quantitative and qualitative analysis of particulates on air filter samples is becoming increasingly important as more air pollution sampling stations are set up throughout the countiy. Although atomic absorption provides a sensitive technique for the analysis of many elements, the disadvantages of complex sample preparation, sample destruction and the necessity to analyze one element at a time make this technique unsuitable for a large volume of samples. X-ray energy spectroscopy when combined with automated sample handling and the latest dedicated data reduction systems provides a technique which enables the analyst to process large numbers of samples and obtain precise quantitative and qualitative data rapidly. This paper will describe the preparation and analysis of typical air filter type samples, and the steps taken to identify the elements in the samples and obtain computerized reduction of the data in μg/cm2, ppm or percent.
X-Ray Spectrometric Determination of Atmospheric Aerosols
Authors: Chessin Henry , McLaren E.H. 
Published: March 2019

AbstractX-ray spectrometric analysis is examined as an analytical tool for elemental determinations of atmospheric aerosols. Contamination levels of the several filters used for collection purposes are examined and the results reported. A calibration technique is described for analysis of several elements in the microgram range based on collection of saturated vapors of aqueous salt solutions. The calibration curves together with an analysis of sensitivity and lower limits of detection are shown. The technique is employed to monitor continuously aerosol content in the atmosphere during passage of a cold front.
Three Dimensional X-Ray Image Synthesis
Authors: Grant David G. 
Published: March 2019

AbstractTomographic systems are able to produce cross sectional planar images of three dimensional volumes because of the relative motion of the source, film and the volume under examination. Analysis shows that the image produced is a result of a three dimensional linear filtering process where the filter characteristics are determined by the scan geometry (3). If, instead of integrating continuously on a single film, a set of N radiographs are recorded, each corresponding to a point along the scan trajectory, then a simple filter can be defined to reconstruct the entire three dimensional structure from this data. In this case, the transfer function exhibits repetitive peaks whose spacing is determined by N and whose width is determined by the total scan length. The number of views required to produce the same “blurring” as the continuous case can then be determined by the Nyquist criteria(3).An optical projection system based on circular geometry for producing three dimensional medical images has been fabricated and tested. The technique can be generalized to any geometry and to all x-ray applications where plane-by-plane examination of a structure would prove beneficial.
Computer Controlled X-Ray Diffraction Measurement of Residual Stress
Authors: Kelly Carol J. , Eichen E. 
Published: March 2019

AbstractThe system to be described includes hardware and software for the on-line computer control of the X-ray diffraction measurement of residual stress. This determination involves accurately measuring the angles at which a back-reflection line is diffracted, first by diffracting planes parallel to the sample surface, and then by planes at an angle (ψ) to the sample surface. The residual stress is calculated from the difference in the two measured diffraetion angles. The procedure executed by the computer consists of locating the peaks, selecting three angles for collection of X-ray counts, correcting the measured counts, fitting the equi-angular intensity measurements to a three-point parabola, calculating the peak angles, calculating the residual stress from the measured angles and typing a report. This automation has eliminated the tedium of the manual X-ray data accumulation and of the residual stress calculation. The online control has also permitted improvements in the technique not practicable with the manually performed measurement of residual stress.
The X-Ray Diffraction Image of a Stacking Fault
Authors: Kato Norio , Usami Katsuhisa , Katagawa Takeshi 
Published: March 2019

AbstractThe spherical wave theory of X-ray Pendellosung fringes in perfect crystals (N. Kato, Acta Cryst, 14: 526, 627, 1961) is extended to the case of crystals including a single stacking fault in an arbitrary way, Kelvin's stationary phase method is used extensively. The stationary phase condition gives us the trajectories of X-ray beams in the crystal. The phase and the amplitude along each trajectory are obtained by straightforward calculation. Based on this crystal wave field, the section patterns in X-ray diffraction topographs are obtained both for the direct and the Braggreflected waves. Characteristic fringe-patterns are expected. Through the image of a fault plane in a single section pattern, the geometrical configuration inside the crystal and the magnitude of the fault vector can be determined. Traverse patterns are also discussed. The fault image based on the plane wave theory (Whelan and Hirsch, Phil. Mag. 2: 1121, 1303, 1957) is also reformulated in the most general Laue case without the use of ad hoc assumptions on the shape of the dispersion surface.