bluuebunny/crossref_metadata_2025_split huggingface dataset:
SPC Analysis of Optimal Strategies for Restandardization of X-ray Fluorescence Analyses
Authors: DeGroot P. B. 
Published: March 2019

AbstractQuantitative XRF analyses almost always depend on measurements of x-ray emission intensities of standards of known composition. The usual approach is a careful initial standardization with multiple standards lhat are checked for accuracy, stability, homogeneity, and internal consistency. This is followed by limited periodic restandardization or recalibration with one or two of the initial standards or a reference sample. The frequency and protocol of these periodic restandardizations tend to be rather arbitrary; for example adjustment on the basis of the average of a triplicate measurement of a standard at the beginning of the work day. There are certainly a large number of other possible restandardization strategies. They range all they way from no restandardization at all, through single or n replicate restandardization measurements before analysis of each group of M unknowns, to cumulative or moving averages, again with variable replicate size, frequency, and now averaging range. This paper examines the outcomes of some of these restandardization strategies applied to synthesized, realistic XRF analysis data which incorporate both abrupt and gradual changes in instrument response. SPC (Statistical Process Control) control charts are shown to be a very useful tool for determining optimum restandardization strategies. Optimal strategies (least scatter in calculated concentrations with fewest standards) which emerged from this study included not restandardizing at all except when indicated by an SPC chart of a reference standard intensity run concurrently with each unknown, and a moving range of 3, with standards run every 5 unknowns, coupled with SPC monitoring of the standards used for this restandardization.
Corrections for the Effect of Scattering on XRF Intensity
Authors: Fernandez J. E. , Molinari V. G. , Sumini M. 
Published: March 2019

AbstractCorrections for scattering on XRF intensity have commonly used integral approaches and isotropic approximations, which give a limited knowledge on this subject. An exact theoretical expression for XRF enhancement due to coherent and incoherent scattering is presented in this paper. It has been obtained as a solution of the Boltzmann transport equation for photons. This equation describes the diffusion of photons in an infinite homogeneous target. Both the excitation and the emission beams have been assumed to be well collimated. The solution accounts for the mixed, scattering and photoelectric interactions. Complete kernels including atomic form factors have been used for both types of scattering. An appropriate kernel has been written for the photoelectric interaction. The correction is computed for several pure elements and is compared with isotropic approximations.
Sample Preparation Optimization for EDXRF Analysis of Portland Cement
Authors: Watson Wayne , Parker Jim , Harding Anthony R. 
Published: March 2019

AbstractVarious sample preparation methods for Energy Dispersive X-ray Fluorescence (EDXRF) analysis of Portland cement were compared in order to evaluate improvement in analytical accuracy and precision. Sample preparation requirements for EDXRF are slightly different than for Wavelength Dispersive X-ray Fluorescence (WDXRF), and the methods commonly used in WDXRF are not optimized for EDXRF. Primarily, the work focuses on techniques for producing a fused sample with the lowest practical concentration of lithium borate flux. Determination of minimum detection limits were made from samples with varying proportions of flux in order to evaluate analytical optimization. Ease and reproducibility of preparation of the sample was also considered.
X-ray Diffractometric Determination of Lattice Misfit Between γ and γ' Phases in Ni-Base Superalloys
Authors: Ohno Katsumi , Harada Hirosi , Yamagata Toshihiro , Yamazaki Michio , Ohsumi Kazumasa 
Published: March 2019

AbstractThe lattice misfits between γ and γ' phases in Ni-base superalloys (single crystal) were accurately determined for filings of specimens by using both a conventional X-ray tube focusing diffractometer(CXRFD) and a synchrotron-radiation parallel beam X-ray diffractometer (SRPXRD). All reflection peaks measured with the CXRFD were in a cluster of overlapping peaks because of the very small differences in the lattice parameters of both phases and the instrumental broadening due to X-ray optics including the spectral distribution of Xray source such as CuKα doublet. The deconvolution method was applied to remove the instrumental broadening from the peaks measured with the CXRFD. The window functions for the deconvolution method were calculated from CuKα doublet reflection of Si standard by a nonlinear least-square method.The instrumental broadening of SRPXRD was much smaller than that of CXRFD since the monochromatic X-rays produced single peak profiles and constant profile shape over a wide 2θ range. A profile fitting with a pseudo-Voigt function was used to determine 2θ angles to 0.0005 deg. for the synchrotron powder data. The peak angle and shape reflected from γ' phases in γ-matrix and those fron electrochemically extracted γ'-phase were significantly different.
Elastic Constants of Alloys Measured with Neutron Diffraction
Authors: Butler B. D. , Murray B. C. , Reichel D. G. , Krawitz A. D. 
Published: March 2019

AbstractElastic constants as a function of crystallographic direction have been measured in polycrystalline alloy samples of 17-4PH stainless steel, Ni-Cr-Fe, and Ti-6%AI-4%V using a neutron diffraction technique. The results compare best with the constant stress model of Reuss. It is demonstrated that measurements of stress can be made sampling the bulk of the material using neutrons with an accuracy comparable to more conventional x-ray methods.
Residual Stresses Near SCC Fracture Surfaces of AISI 4340 Steel
Authors: Yajima Zenjiro , Tsuda Masaaki , Hirose Yukio , Tanaka Keisuke 
Published: March 2019

X-ray diffraction observation of the material beneath the fracture surface provides failure analysists with useful information to judge the mechanical condition of fracture.In the present paper, stress corrosion cracking (SCC) tests were conducted by using the bluntly notched compact tension (CT) specimens of 200°C tempered AISI 4340 steel in a 3.5 NaCl solution etwixonmeat. The distribution of the residual stress beneath the fracture surface near the root of the notch was measured with the X-ray diffraction technique. The effect of the notch root radius on crack nucleation with stress corrosion was discussed on the bases of the results of X-ray observation.
Semi-Quantitative XRD Analysis of Fly Ash Using Rutile as an Internal Standard
Authors: Thedchanamoorthy A. , McCarthy G.J. 
Published: March 2019

AbstractXRD analysis of fly ash was quantitated using the Reference Intensity Ratio (RIR) method and rutile (TiO2) as an internal standard. Rutile RIR's for 15 of the crystalline phases commonly observed in North American fly ash were determined. Error analysis on the various steps in quantitation indicated that precision ranged from ±10% of the amount present for phases that diffract x-rays strongly to ±21% for weakly diffracting phases. Limit of detection in the mostly glassy fly ashes ranged from 0.2% for lime, the most strongly diffracting phase, to 3.5% for weakly diffracting mullite. Accuracy evaluated with a simulated fly ash was within the limits established by precision, but in actual fly ash samples, accuracy will be a function of the match between the crystallinity and composition of the analyte and the analyte standard. Overlaps among peaks of some of the important phases require intensity proportioning; for this reason, the method is best described as semi-quantitative.
Use of Scattered Secondary Target Radiation in EDXRF Analysis: A Fundamental-Parameter Method for Matrix Correction
Authors: O'Reilly Tom , King Bi-Shia W. 
Published: March 2019

AbstractA new fundamental-parameter program has been developed which corrects for light element absorption based on the mean atomic number of the sample. The mean atomic number, in turn, is determined from the Compton/Rayleigh scatter intensity ratio. The program is quite flexible with regard to the number and the type of standards which may be used. The accuracy and precision of the method has been evaluated with several geological and biological standards. The results are in good agreement with those obtained by some other methods (CEMAS, XRF-11).
Advances in High-Resolution Studies of the Chemical Effects in the Molybdenum L Heavy-Ion-Induced X-Ray Satellite Emission (HIXSE) Spectra*
Authors: Rosseel T. M. , Dale J. M. , Hulett L. D. , Pepmiller P. L. , Vane C. R. , Walkiewicz T. A. , Young J. P. 
Published: March 2019

AbstractHigh-resolution measurements of the molybdenum L heavy-ion-induced X-ray satellite emission (HIXSE) spectra of a series of Mo alloys and compounds have been obtained with a new, high-efficiency, high-resolution Bragg crystal spectrometer in the von Hamos geometry. The improved resolution (5 eV at 2.3 keV) is sufficient to reveal the LnMm configuration lines in the Lα and Lβ hypersatellite bands. Both sets of lines exhibit the same trend in the variation of the relative yield distribution with the chemical environment as was observed for KLn lines of lower Z targets. Difference spectra, using elemental molybdenum as a subtrahend, enhance the systematic variation. These results confirm the analysis and conclusions of lower resolution studies. They also indicate a potential for even greater sensitivity to the chemical environment.
An X-Ray Fluorescent Spectrometer for the Measurement of Thin Layered Materials on Silicon Wafers
Authors: Arai Tomoya 
Published: March 2019

The developments in the analysis of low atomic number elements or the measurements of soft and ultrasoft X-rays have been carried out. Using this technology, a measuring method for thinner layered materials has been developed recently. This type of analysis requires a high excitation and wavelength dispersive devices with high reflectivity.On the other side, the film technologies related to electronic and optical devices in the field of semiconductor industry have made a remarkable progress. A variety of layered material thickness in the multilayered structure of LSI is in the range of 100Å and 2μm. It is too thick to be measured by electron methods and too thin to be measured by a regular X-ray method using the X-ray wavelength of 0.2-3Å. Accordingly, it is generally said that the soft and ultrasoft X-ray method should be applied to measure the thickness and composition of layered materials on silicon wafers.
A New High-Temperature Camera for Diffraction Studies Above 2200°C
Authors: Mantler Michael , Ebel Horst 
Published: March 2019

The presented paper describes design and operational characteristics of a new high-temperature camera. The design is developed from the widely used Anton Paar camera, but several of its major disadvantages were eliminated.The specimen is directly mounted on an electrically-heated metal strip. The most important improvement over the original camera is a provision for the compensation of the thermal expansion of the heating strip. Fig. 1 shows a Ta-heater after using it at temperatures above 2000°C without adequate compensation; the specimen, which is mounted at the center of the strip, is considerably displaced during the measurement and large errors occur in the measurement of the reflecting angles.The improved overall design allows temperatures (at the heater) above 3000°C to be reached. The highest temperature measured so far at a tungsten strip was 3350°C, which is only 40° below its melting point.
Use of X-Ray Curved Sensitive Position Detector for Simultaneous Measurement of Several Pole Figures
Authors: Heizmann J.J. , Laruelle C. , Vadon A. 
Published: March 2019

At the moment, the time required to obtain a pole figure is about three hours, and generally several pole figures are needed to make a texture analysis. Therefore the time and the cost of texture measurement are widely increased.Now, new position sensitive X-Ray detectors are appearing, which allow to record at one and the same time the whole 2Θ spectrum, i.e. the beams diffracted by several (hi k1l1) lattice planes. So with this kind of detector, it will be possible to get simultaneously several pole figures.
Correlations Between X-Ray Microstructures and Magnetic Properties of CoCrTa Alloy thin Films
Authors: Huang T. C. 
Published: March 2019

AbstractThin film structures determined by X-ray reflection and transmission diffractometer methods has been used to co rrelate with th e magnetic p roperties of CoCrTa thin films. Well-crystallized CoCrTa alloy particles with strong h.c.p. c-axis preferred oriented normal to the film surfaces were found to be mainly responsible for the perpendicular magnetic anisotropy observed in specimens IL and 8L, whereas poorly crystallized CoCrTa particles in the 150Å thick magnetic layers of a third specimen 33L have led to an observed longitudinal magnetization. Microstrains generated by the crystalline - amorphous interface stresses induced an enhanced perpendicular magnetic anisotropy in specimen 8L. Values of crystallite size D determined from the Warren-Averbach analysis were correlated with the coercivities He. Analysis of the He vs. D curve indicated th a t the critical particle size for a magnetic multi- to single-domain transition was 270± 25Å. The retention in coercivity (Hc=175 Oe) at a small particle size (D=75Å) in specimen 8L suggested that strong interparticle interactions existed among the wellcrystallized CoCrTa particles. A much smaller retention in coercivity (Hc=90 Oe) at D=70Å of specimen 33L indicated the inter particle interactions in poorly crystallized CoCrTa layers were relatively weak.
Defect Structure of Synthetic Diamond and Related Phases
Authors: Badzian Andrzej R. 
Published: March 2019

AbstractThis paper examines the relationship between the lattice defects and crystallization process of synthetic diamonds. Diamonds synthesized by high pressure, high temperature methods as well as diamonds vapor deposited under metastable conditions are considered. High pressure crystals precipitated from Ni or Co solutions contain inclusions of metastable carbides and metal atoms distributed throughout a small fraction of the octahedral holes in the diamond lattice.Diamonds are grown metastabily by a chemical vapor deposition process in which CH4 and H2 are excited by a microwave plasma. Such diamonds are deposited as individual micro-monocrystals or as solid poly crystalline films. The defects in such crystals are related to impurities such as Si and H which produce point defects and tend to nucleate graphite, which can generate planar defects. Nucleation of a diamond phase on β-SiC is also considered, because of the lattice matching between them.Diamond structure is a prototype of a family of related phases such as cubic BN (sphalerite structure) and solid solutions of diamond and cubic BN, Cubic BN-diamond solid solutions (BN)x(C2)1-x,0<x<l are, in turn, a prototype of AIIIBV-CIV phases, of which (GaP)x(Si2)1-x,0<x<l is an example. Substitution of B-N (or Ga-P) by C-C (or Si-Si) atom pairs at lattice sites is characteristic of these solid solutions.
A New Method for Evaluating X-Ray Diffraction Peak Broadening With Engineering Applications
Authors: Kurita Masanori 
Published: March 2019

AbstractA new method is proposed for evaluating rapidly the diffraction peak broadening by using the standard deviation of a Gaussian function approximating the diffraction peak. This value, called the Gaussian curve parameter (GCF), is given byThe use of the GCP permits rapid and nondestructive measurement of plastic strain and hardness of quenched and tempered steels with an automated X-ray stress analyzer using a personal computer. The GCP increases with increasing hardness of quenched and tempered steels. It also increases with increasing plastic strain by stretching. Furthermore, the GCP can be used for rapidly evaluating hardening of quenched steels.
X-Ray Stress Measurement of Ni-Ai System Intermetallic Compounds
Authors: Goto Tokimasa , Tabata Hiroyuki , Hirose Yukio 
Published: March 2019

The microstructures and mechanical properties of Ni-Al system intermetallic compounds used as heat resisting materials have been investigated by many researchers[l,2], but there are few studies applying X-ray stress measurement to these materials[3]. Two problems make it difficult: One is the comparatively coarse grain size, the other is the strong preferred orientation along the direction of the solidification. Therefore, it become possible to evaluate mechanical behavior in these materials, if we can measure the residual stresses correctlv by X-rays.In this paper, Ni-25mol%AI(Ni3Al) made by the arc-melting method was employed. It consists of comparatively coarse grains and has strong preferred orientation along the direction of the solidification.
Controlled-Humidity XRD Analyses: Application to the Study of Smectite Expansion/Contraction
Authors: Chipera Steve J. , Carey J. William , Bish David. L. 
Published: March 2019

Smectites are clay minerals that expand and contract dramatically in response to changes in water vapor pressure. The expansion/contraction behavior of smectite has considerable importance in engineering applications (such as the stability of building foundations and the integrity of clay barriers) and affects hydrologic properties. To understand this behavior we have analyzed several purified, homoionic smectite standards over a wide range of relative humidities using X-ray powder diffraction (XRD) and a new computer-automated humidity-control system.Humidity was controlled by mixing dry N2 with H2O-saturated (“wet”) N2 produced with a gas-washing bubbler held in a constant-temperature bath set at 35°C. Mixing of wet and dry N2 was controlled with automated MKS mass-flow controllers.
Accuracy of Clinical Diagnostic Criteria for Patients With Vascular Ehlers-Danlos Syndrome in a Tertiary Referral Centre
Authors: Henneton Pierrick , Albuisson Juliette , Adham Salma , Legrand Anne , Mazzella Jean Michael , Jeunemaitre Xavier , Frank Michael 
Published: March 2019

Background:
Vascular Ehlers-Danlos syndrome is a rare inherited connective tissue disease secondary to mutations within the COL3A1 gene. The diagnosis of vascular Ehlers-Danlos syndrome is challenging, and patient selection for genetic testing relies on diagnostic criteria, which have never been evaluated.

Methods:
All patients seen at a dedicated tertiary referral center for a suspicion of vascular Ehlers-Danlos syndrome between January 2001 and March 2016 were retrospectively included in a diagnostic accuracy study. Major and minor diagnostic criteria of the Villefranche classification were tested for sensitivity, specificity, positive and negative predictive values, according to results of genetic testing.

Results:
N=519 patients were eligible for analysis dividing into n=384 probands and n=135 relatives. A pathogenic COL3A1 variant was identified in n=165 (31.8%) patients. The Villefranche criteria were met for n=248 patients with a sensitivity of 79% (95% CI, 0.72–0.85) and a negative predictive value of 87% (95% CI, 0.83–0.91). Diagnostic accuracy was highest for symptomatic probands (sensitivity 92%; negative predictive value 95%) with limited specificity (60%). Probands ≤25 years had the worst diagnostic performance. The revised diagnostic Criteria (2017) were less accurate than the Villefranche classification (overall diagnostic odds-ratio, 4.17 versus 7.8; probands diagnostic odds-ratio, 4.04 versus 18.1; and probands ≤25 years diagnostic odds-ratio, 2.36 versus 5.1) mainly due to a lack of sensitivity.

Conclusions:
The Villefranche criteria provide accurate detection of symptomatic probands in specialized practice but have limited specificity. The revised diagnostic criteria for vascular Ehlers-Danlos syndrome have increased specificity, but its overall performance is poorer. The early clinical diagnosis of probands without family history is not addressed by both diagnostic classifications.
Implications of a Climate-Changed Atmosphere on Cool-Climate Viticulture
Authors: Schultze Steven R. , Sabbatini Paolo 
Published: March 2019

AbstractThe impact of anthropogenic global warming on viticulture has been thoroughly studied. However, many of the climate projections are limited by the resolution of the models that cannot resolve mesoscale weather patterns, which heavily influence grape production. In this work, data were gathered from the National Center for Atmospheric Research wherein a high-spatiotemporal-resolution (4 km× 4 km, 1 h) Weather Research and Forecasting (WRF) Model was run from October 2000 to September 2013 over North America using observed data, and again using the atmospheric chemistry of CMIP5 ensemble mean of the RCP8.5 greenhouse gas emission scenario, creating a pseudo–global warming (PGW) model. Such models are capable of resolving the mesoscale influences that most climate models cannot. Contrasting the observed results to the PGW results allows users to compare “what happened” to “what could have happened.” This analysis was applied to four cool-climate viticultural regions in the United States: two in Michigan, one in upstate New York, and one in Oregon. In the PGW run, hours exposed to extreme heat (>32°C) increase by orders of magnitude. Growing season degree-day (GDD) accumulations increase between 783 and 1057 base 10°C in comparing the models, while growing season average temperatures increase between 4.05° and 5.53°C. Precipitation patterns were also studied. The four regions would no longer classify as “cool climate” and would see growing seasons similar to some of the most productive warm-climate wine-producing regions. The authors consider the opportunities and challenges presented by the potential climate shift for cool-climate and warm-climate viticultural regions.
A Global Climatology of Extratropical Transition. Part I: Characteristics across Basins
Authors: Bieli Melanie , Camargo Suzana J. , Sobel Adam H. , Evans Jenni L. , Hall Timothy 
Published: March 2019

AbstractThe authors present a global climatology of tropical cyclones (TCs) that undergo extratropical transition (ET). ET is objectively defined based on a TC’s trajectory through the cyclone phase space (CPS), which is calculated using storm tracks from 1979–2017 best track data and geopotential height fields from reanalysis datasets. Two reanalyses are used and compared for this purpose, the Japanese 55-yr Reanalysis and the ECMWF interim reanalysis. The results are used to study the seasonal and geographical distributions of storms undergoing ET and interbasin differences in the statistics of ET occurrence. About 50% of all TCs in the North Atlantic and the western North Pacific undergo ET. In the Southern Hemisphere, ET fractions range from about 20% in the south Indian Ocean and the Australian region to 45% in the South Pacific. In the majority of ETs, TCs become thermally asymmetric before forming a cold core. However, a substantial fraction of TCs take the reverse pathway, developing a cold core before becoming thermally asymmetric. This pathway is most common in the eastern North Pacific and the North Atlantic. Different ET pathways can be linked to different geographical trajectories and environmental settings. In ETs over warmer sea surface temperatures, TCs tend to lose their thermal symmetry while still maintaining a warm core. Landfalls by TCs undergoing ET occur 3–4 times per year in the North Atlantic and 7–10 times per year in the western North Pacific, while coastal regions in the Australian region are affected once every 1–2 years.