bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation into repetitive concussion in sport (RECOS): study protocol of a prospective, exploratory, observational cohort study
Authors: Yakoub Kamal M , Davies David J , Su Zhangjie , Bentley Conor , Forcione Mario , Toman Emma , Hammond Douglas , Watson Callum N , Bishop Jon , Cooper Lauren , Barbey Aron K , Sawlani Vijay , Di Pietro Valentina , Grey Michael J , Belli Antonio
Published: July 2019

Introduction

Sport-related concussion management remains a diagnostic dilemma to clinicians in all strata of care, coaching staff and players alike. The lack of objective diagnostic and prognostic biomarkers and over-reliance on subjective clinical assessments carries a significant health risk of undiagnosed concussive episodes and early return to play before full recovery increasing the risk of sustaining additional concussion, and leading to long-term sequelae and/or unfavourable outcome.

Objective

To identify a set of parameters (neuroimaging with neurophysiological, biological and neuropsychological tests) that may support pitch-side and outpatient clinical decision-making in order to objectively diagnose concussion, determine the severity of injury, guide a safe return to play and identify the potential predictors of the long-term sequelae of concussion.

Methods and analysis

An exploratory, observational, prospective, cohort study recruiting between 2017 and 2020. The participants will have a baseline preseason screening (brain imaging, neuropsychological assessments, serum, urine and saliva sampling). If a screened player later suffers a concussion and/or multiple concussions then he/she will be assessed again with the same protocol within 72 hours, and their baseline data will be used as internal control as well as normative data. Inferential statistical analysis will be performed to determine correlations between biological, imaging techniques and neuropsychological assessments.

Ethics and dissemination

This study was approved by the East of England—Essex Research Ethics Committee on 22 September 2017—REC 17/EE/0275; IRAS 216703. The results of this study will be presented at national and international conferences and submitted for publication in peer reviewed journals.

Trial registration number

ISRCTN16974791; Pre-results.
Suicide, other externally caused injuries and cardiovascular death following a cancer diagnosis: study protocol for a nationwide population-based study in Japan (J-SUPPORT 1902)
Authors: Harashima Saki , Fujimori Maiko , Akechi Tatsuo , Matsuda Tomohiro , Saika Kumiko , Hasegawa Takaaki , Inoue Keisuke , Yoshiuchi Kazuhiro , Miyashiro Isao , Uchitomi Yosuke , Matsuoka Yutaka J
Published: July 2019

Introduction

A growing body of literature has demonstrated that cancer patients have a higher risk of suicide and cardiovascular mortality compared with the general population, especially immediately after a cancer diagnosis. Using data from the National Cancer Registry in Japan launched in January 2016, we will conduct the first nationwide population-based study in Japan to compare incidence of death by suicide, other externally caused injuries (ECIs) and cardiovascular disease following a cancer diagnosis with that of the general population in Japan. We will also aim to identify the patient subgroups and time periods associated with particularly high risk.

Methods and analysis

Our study subjects will consist of cancer cases diagnosed between 1 January 2016 and 31 December 2016 in Japan and they will be observed until 31 December 2018. We will calculate standardised mortality ratios (SMRs) and excess absolute risks (EARs) for suicide, other ECIs and cardiovascular death compared with the general population in Japan, after adjustment for sex, age and prefecture. SMRs and EARs will be calculated separately in relation to a number of factors: sex; age at diagnosis; time since cancer diagnosis; prefecture of residence at diagnosis; primary tumour site; behaviour code of tumour; extension of tumour; whether definitive surgery of the primary site was performed; and presence/absence of multiple primary tumours.

Ethics and dissemination

The study protocol was approved by the institutional review board and ethics committee of the National Cancer Center Japan and Nagoya City University Graduate School of Medical Sciences. The findings will be disseminated through peer-reviewed publications and conference presentations.

Trial registration number

UMIN000035118; Pre-results.
Estimating soil erosion intensity in susceptible areas based on a comprehensive stratified sampling system associated with the geographical information system
Authors: Wang Liang-Jie , Zhang Hongda , Qi Fei , Liu Xia , Zhang Qinghong , Zhang Chunqiang , Yuan Li , Yao Xiaoyou
Published: July 2019

An error-free and fast approach for the identification of the area dynamics of soil erosion intensity (SEI) is essential for local governments. In this study, a simple method combination of the vegetation cover, gradient slope, and land use coupling index (vegetation and slope coupling index) model with field sampling unit schemes was explored to estimate the area variations of SEI between the years 1998 and 2009. The obtained results show that the minimum average prediction accuracy (PA) for sampling units was 94% among different land use types, whereas the maximum PA was 98.5%. Although PAs for different land use types showed discrepancies, the trend clearly depicted higher rates of sampling units and lower relative errors. The average fitting accuracies (FAs) of the sampling units were 98.84%, 97.92%, and 97.26%, respectively, based on different proposed strategies, whereas the FAs of the extrapolation results were 94.77%, 87.57%, and 92.41%, respectively. In addition, the extrapolation results were found to be less efficient than the sampling units. However, this is acceptable, considering the field observation workloads and time consumption. Therefore, this study provides a promising scheme for the rapid estimation of the area dynamics of SEI, which will be useful for estimating the SEI in other areas.
Are quantum corrections on horizon scale physically motivated?
Authors: Compère Geoffrey
Published: July 2019

The aim of this paper is to give an overview to nonspecialists of recent arguments from fundamental physics in favor and disfavor of quantum corrections to black hole horizons. I will mainly discuss the black hole information paradox, its possible resolutions and shortly address its relevance or irrelevance to astronomy.
Breakdown of the equivalence between gravitational mass and energy due to quantum effects
Authors: Lebed Andrei G.
Published: July 2019

We review our recent theoretical results about inequivalence between passive and active gravitational masses and energy in the semiclassical variant of general relativity, where the gravitational field is not quantized but matter is quantized. To this end, we consider the simplest quantum body with internal degrees of freedom — a hydrogen atom. We concentrate our attention on the following physical effects, related to electron mass. The first one is the inequivalence between passive gravitational mass and energy at the microscopic level. Indeed, the quantum measurement of gravitational mass can give a result which is different from the expected one, [Formula: see text], where the electron is initially in its ground state; [Formula: see text] is the bare electron mass. The second effect is that the expectation values of both the passive and active gravitational masses of stationary quantum states are equivalent to the expectation value of the energy. The most spectacular effects are the inequivalence of the passive and active gravitational masses and the energy at the macroscopic level for an ensemble of coherent superpositions of stationary quantum states. We show that, for such superpositions, the expectation values of passive and active gravitational masses are not related to the expectation value of energy by Einstein’s famous equation, [Formula: see text]. In this paper, we also improve several drawbacks of the original pioneering works.
Study of Y1Ba2Cu3O7−δ+CuO Nanocomposite as a Resistive Current Limiter
Authors: Ushakov A. V. , Karpov I. V. , Demin V. G. , Shaihadinov A. A. , Demchenko A. I. , Bachurina E. P. , Fedorov L. Yu. , Goncharova E. A.
Published: July 2019

The influence of CuO nanoscale inclusions as the second component of the composites on the transport properties of superconducting polycrystals YBa2Cu3O7 was studied. Samples of YBa2Cu3O[Formula: see text] with different content of CuO nanoparticles were synthesized. The analysis of magnetic properties was carried out within the framework of the extended critical state model. It was found that the addition of 20[Formula: see text]wt.% CuO nanoparticles leads to an increase in the critical current density at [Formula: see text][Formula: see text]K. A further increase to 30[Formula: see text]wt.% reduces the critical current density. The results of the experimental studies of a switching superconducting fault current limiter in AC voltage networks based on high-temperature superconductors (HTSC) of the 2nd generation are given in this work. The testing equipment contains a series-connected HTSC module and a high-speed current switch with a break time of 9[Formula: see text]ms. The high efficiency of the samples made from the YBa2Cu3O[Formula: see text] + CuO nanocomposite material as an active element of a resistive current limiter is shown.
Decision Models to Find a Promising Start-Up Firm with Qualiflex under Probabilistic Linguistic Circumstance
Authors: Tian Xiaoli , Xu Zeshui , Wang Xinxin , Gu Jing , Alsaadi Fawaz E.
Published: July 2019

QUALIFLEX is a flexible method to solve the multi-criteria decision-making problem with a few alternatives. Moreover, the linguistic term is a very general way used by decision makers (DMs) to express their real perceptions. In particular, the probabilistic linguistic information, including the probability of each linguistic term, can simulate the vague perceptions of the DMs well. Therefore, the main contributions of this paper are constructing two novel QUALIFLEX with probabilistic linguistic information. First, based on the classical QUALIFLEX, it has been extended under probabilistic linguistic circumstance. Secondly, it is common for the DMs to have different risk attitudes for gains and losses when making their decisions under uncertainty, which is well explained by prospect theory (PT). Hence, PT has been integrated into the extended QUALIFLEX. Then, in this paper, a prospect QUALIFLEX is proposed as well. The feasibility and validity of the proposed methods have been verified by a numerical example in venture capital. The comparative and simulated analysis shows that the latter method with prospect framework is more appropriate than the former one because of the inherent psychological behaviors of the DMs and its excellent ability in identifying the similar alternatives. Furthermore, the ranking results derived from the prospect QUALIFLEX do not change with the different values of parameters. It reveals that the prospect QUALIFLEX is stable and reliable.
An Interval-Based Approach for Evolutionary Multi-Objective Optimization of Project Portfolios
Authors: Balderas Fausto , Fernandez Eduardo , Gomez-Santillan Claudia , Rangel-Valdez Nelson , Cruz Laura
Published: July 2019

Project portfolio selection is addressed here as a multi-objective optimization problem. This work introduces an interval-based method that takes into consideration imperfect knowledge of the contribution of projects to a portfolio, the project requirements, available resources and preference parameters in the model. The multi-objective optimization problem is solved using an evolutionary algorithm that is adapted to handle intervals. To direct the search toward the region of interest of the Pareto frontier, the preferences of the decision maker (DM) are incorporated using an interval-based outranking approach. This allows to address problems with many objective functions; intransitive preferences and incomparability situations can also be handled using this approach. In terms of analyzing robustness, the DM can obtain different solutions according to his/her level of conservatism. The effectiveness of this proposal was tested both on an example from the related literature and another example of a public project portfolio with nine objective functions and large number of applicant projects.
DO EXCHANGE RATE CHANGES HAVE SYMMETRIC OR ASYMMETRIC EFFECTS ON INTERNATIONAL TRADE INTEGRATION?
Authors: RAJPUT SURESH KUMAR OAD , GHUMRO NIAZ HUSSAIN , ANJUM NADIA
Published: July 2019

This paper investigates whether exchange rate changes have symmetric or asymmetric effects on international trade integration, using quarterly time series data from 1980: Q1 till 2018: Q2. The recent innovation in cointegration techniques allows us to estimate nonlinear effects. We apply both linear autoregressive distributed lags (ARDL) and nonlinear ARDL models. The empirical results indicate that asymmetric relationship exists between exchange rate (REER) and international trade integration (ITI) in the short-run as well as in the long-run, meaning that real effective exchange rate has negative and statistically significant effects on international trade integration. Robustness checks indicate no role of various crisis including GFC on the relationship between ITI and REER, however, regime change has significantly negative impact in short-run and positive in long-run on ITI. The results are important because when we separate currency appreciation from the depreciation, it has the significant and different effects on international trade integration.
Dynamic Characterization in Advanced Manufacturing
Authors: Snyder Robert L. , Chen Bin-Jiang
Published: July 2019

The coming era of reduced defense funding will dramatically alter the way in which advanced materials develop. In the absence of large funding researchers must concentrate on reducing the time that the R&D of a new materia) consumes. One way in which speed may be achieved is via the development of very fast dynamic characterization procedures which can rapidly and intelligently monitor and optimize the formation of a desired microstructure. Another potential advantage to this approach is its ability to characterize the actual amount of material which goes into a final product; permitting a rapid transition from R&D to manufacturing by avoiding the problems associated with scale-up. Example high-temperature dynamic characterization procedures have been applied to the problem of trying to improve the current carrying capacity of the YBa
2
Cu
3
O
7-8 ceramic superconductor by melt-texturing. These procedures have led to a technique for the preparation of specimens with J
c on the order of 10,000 A/cm2.
Diffraction Space Mapping of Heteroepitaxial Layers
Authors: Halliwell Mary
Published: July 2019

The acceptance angle of the detector of a double axis diffractometer is designed such that all of the diffracted beam is recorded for a rocking curve. When this acceptance angle is reduced, as in the triple axis diffractometer, two dimensional diffraction data can be recorded. In the resulting diffraction space maps each diffraction feature has a shape and a position from which the unit cell dimensions of a heteroepitaxial layer can be derived as well as information about relative tilts, curvature, lattice parameter variations and defect densities. Applications of diffraction space mapping using high and low resolution optics are discussed
Interfaces and Strain in InGaAsP/InP Heterostructures Assessed with Dynamical Simulations of High-Resolution X-ray Diffraction Curves
Authors: Vandenberg J. M.
Published: July 2019

The interfacial structure of a lattice-matched InGaAs/InP/(100)InP superlattice with a long period of ∼630Å has been studied by fully dynamical simulations of high-resolution x-ray diffraction curves. This structure exhibits a very symmetrical x-ray pattern enveloping a large number of closely spaced satellite intensities with pronounced maxima and minima. It appears in the dynamical analysis that the position and shape of these maxima and minima is extremely sensitive to the number N of molecular layers and atomic spacing d of the InGaAs and InP layer and in particular the presence of strained interfacial layers. The structural model of strained inrerfaces was also applied to an epitaxial lattice-matched 700Å InP/400Å InGaAsP/(100)InP heterostructure.
High Resolution X-ray Diffractometry and Topography of Float-Zone GaAs Crystals Grown in Microgravity
Authors: Loxley N. , Moore C. D. , Safa M. , Tanner B. K. , Clark G. F. , Herrmann F. M. , Mueller G.
Published: July 2019

High resolution Bragg-case X-ray double and triple axis diffractometry and Laue-case white beam synchrotron X-ray topography experiments have been performed on undoped [001] oriented float-zone GaAs crystals have been grown under microgravity conditions in space on the D2 mission. Near the seed, excellent anomalous transmission was achieved and a clear cellular structure of dislocations observed. The double and triple axis rocking curves were comparable with those from semi-insulating terrestrial material. Following a heater failure, the molten zone height dropped and reciprocal space maps revealed a long ridge of scatter transverse to the diffraction vector direction. This corresponds to the presence of a distribution of sub-grains containing little internal strain. Continued growth resulted in twin formation.
Reciprocal Space Mapping of Epitaxial Materials Using Position-Sensitive X-ray Detection
Authors: Lee S. R. , Doyle B. L. , Drummond T. J. , Medernach J. W. , Schneider P.
Published: July 2019

Reciprocal space mapping can be efficiently carried out using a position-sensitive x-ray detector (PSD) coupled to a traditional double-axis diffractometer. The PSD offers parallel measurement of the total scattering angle of all diffracted x-rays during a single rocking-curve scan. As a result, a two-dimensional reciprocal space map can be made in a very short time similar to that of a one-dimensional rocking-curve scan. Fast, efficient reciprocal space mapping offers numerous routine advantages to the x-ray diffraction analyst. Some of these advantages arc the explicit differentiation of lattice strain from crystal orientation effects in strain-relaxed heteroepitaxial layers; the nondestructive characterization of the size, shape and orientation of nanocrystalline domains in ordered-alloy epilayers; and the ability to measure the average size and shape of voids in porous epilayers. Here, the PSD-based diffractometer is described, and specific examples clearly illustrating the advantages of complete reciprocal space analysis are presented.
Real Time Synchrotron Topography Using a CID Array Camera with Digital Image Acquisition and Processing
Authors: Winter John M. , Green Robert E.
Published: July 2019

Synchrotron white beam transmission topography of GaAs as previously reported by the authors relied on scanning specimen and film synchronously through the incident x-ray beam to record transmission topographic images en film. Sometimes the total dose required for reasonable contrast on film carried with it enough thermal deposition to cause elastic warping of the wafer. To escape these problems, a real time system was assembled. This system included an image intensifier, a solid state camera, a computer board to frame-grab and digitize images, and appropriate image processing software. With this system, a three inch specimen was scanned from edge to edge in one minute. At this scan rate, the incident x-ray beam had to be significantly attenuated to avoid saturating the intensifier output.
Homogeneous Strain Relaxation and Mosaic Spread in InGaAs/GaAs Heterostructures Using Triple Axis Diffractometry
Authors: Goorsky M. S. , Matney K. M. , Chu G. , Goldman R. S. , Kavanagh K. L.
Published: July 2019

We investigated strain relaxation in (001) InGaAs/GaAs structures using both double and triple axis high resolution x-ray diffraction techniques. We determined diat broadening which is observed in double axis scans stews pnmanly from mosaic spread and not from lattice constant variations in the layer, demonstrating that relaxation is uniform along the growth direction. These observations held for layers with both low and high indium content and extents of relaxation. Triple axis measurements showed that the peak broadening was due exclusively to mosaic spread for the low indium content samples and also confirmed earlier double axis measurements that a crystallographic tilt of the epitaxial layer was attributed to substrate miscut. The ability to distinguish the source of peak broadening and crystallographic tilts makes triple axis diffraction a powerful characterization technique for the study of mismatched epitaxial layers.
Fluorine Implantation and Residual Stresses in Polysilicon Films
Authors: Lowry Lyan , Zschack Paul , De Angelis Robert
Published: July 2019

X-ray diffraction techniques were utilized to study the film stress effects in silicon wafers subjected to several processing conditions. The wafer processing matrix consisted of three thicknesses of polysilicon deposited on (100) silicon with a 25 nm layer of Si02. The polysilicon was doped with phosphorous and arsenic after which the samples were implanted with fluorine at 30 KeV at a dose of 6 × 1015 cm2. A synchrotron radiation source at Brookhaven National Laboratory on beamline X-14 was employed to determine the residual stresses in the polysilicon film by a powder diffraction technique ordinarily used on poly crystal line material X-ray rocking curve experiments were employed to determine the stress in the film from measurements of the curvature of the substrate. These two stress measurements allow the estimation of the stress gradient in the intermediate amorphous oxide layer. Correlations are made between the stress gradients, the fluorine distribution in the wafer and the electrical characteristics of the structures.
Determination of Composition and Phase Depth-Profiles in Multilayer and Gradient Solid Solution Photovoltaic Films Using Grazing Incidence X-ray Diffraction
Authors: Ballard B. L. , Zhu X. , Predecki P. K. , Albin D. , Gabor A. , Turtle J. , Noufi R.
Published: July 2019

A method for using grazing incidence x-ray diffraction (GIXD) for profiling composition changes with depth of photovoltaic quality thin films is presented. The average thickness of the first layer in a multi-layer film of CuIn2Se3.5/CuInSe2/Mo and the variation in solid solution composition of a Cu(In1-xGax)Se2 (CIGS) film with depth are solved using this method. The phase volume fraction and the phase composition profiles are developed from peak intensity and d-spacing measurements respectively at a series of fixed incident angles corresponding to a set of increasing 1/e penetration depths, τ. Inverse Laplace and numerical methods are applied to the τ profiles converting them to true depth profiles. Vegard's law is applied to the d-spacing vs z-profile to obtain x in the formula Cu(In1-xGax)Se2. The results show that an ∼1 μm thick layer of CuIn2Se3.5 is present on the surface of the multi-layer film and that the CIGS film consists of a Ga rich surface layer ∼2000 Å thick followed by a gradual decrease in Ga content with increasing depth. This gradient appears to be desirable for producing photovoltaic quality CIGS films.
Computational (ω, φ) X-ray Diffractometry for Single Crystal Analysis
Authors: Dragoi Danut
Published: July 2019

(ω, φ) X-ray Diffraetometry is a method of XRD based on two independent variables, ω–the rotation of the sample around an axis contained in the plane of the sample and normal to the incident beam, and-the rotation of the sample in its own plane. Each crystallographic plane has an φ peak position, i.e. diffracted intensity is a maximum at a particular ω position for a given φ position. The incident X-ray beam is considered to be parallel, (a divergence of 0.1 degrees or less is accepted), very narrow (the width of the beam is not critical, a width of 0.1 mm or less is accepted), and monochromatic. The position of the detector is not a necessary variable in this system. Its open X-ray sensitive area collects the photons from the diffracting planes at different positions on that sensitive area. Using the method, the diffraction angles 2θ of different crystallographic planes can be determined without the need for knowing the position of the detector, which is a large area detector, free of slits between the sample and the area sensitive to the X-ray photons. Consequently the detector can be placed in a favorable position such as close to the sample.

The method can be applied to any crystal symmetry. If the symmetry of the crystal is known then a theoretical ω(φ) curve can be generated and compared with the experimental data. The difference between these two curves can be easily computed and attributed to the crystallographic lattice distortions of the sample.
Synchrotron X-ray Microbeam Characteristics for X-ray Fluorescence Analysis
Authors: Iida A. , Noma T.
Published: July 2019

X-ray fluorescence analysis using a synchrotron x-ray microprobe has become an indispensable technique for non-destructive micro-analysis. One of the most important parameters that characterize the x-ray microbeam system for x-ray fluorescence analysis is the beam size. For practical analysis, however, the photon flux, the energy resolution and the available energy range are also crucial. Three types of x-ray microbeam systems, including monochromatic and continuum excitation systems, were compared with reference to the sensitivity, the minimum detection limit and the applicability to various types of x-ray spectroscopic analysis.
The Study of Some Peculiar Phenomena in Ultra-Soft X-ray Measurements Using Synthetic Multilayer Crystals
Authors: Kobayashi H. , Toda K. , Kohno H. , Arai T. , Wilson R.
Published: July 2019

Several interesting phenomena involving ultra-soft X-rays and synthetic multilayer crystals were studied as a result of the on-going process of improving the Rigaku Mode] 3630 Wafer Analyzer for the measurement of BPSG (1000-2500 Å) and other thin films.1-3 These phenomena can be divided into four categories; “ghost” peaks, diffraction from the substrate, fluorescence from the multilayer and higher order lines from the multilayer. Each of these is a potential snurce nf error in the measurement of ultra-soft X-rays, Fortunately, as will be shown, each can be readily dealt with.
Automated Measurement of Grain Orientations and On-Line Determination of Complete Deformation Systems with a TEM
Authors: Schwarzer R. A. , Zaefferer S.
Published: July 2019

An automated computer technique for the indexing of spot or transmission Kikuchi patterns from any crystal structure has been developed. The patterns are recorded from the fluorescence screen of a PHILIPS EM 430 TEM with an integrating, Peltier cooled CCD camera (PULNIX TM 86QN) through a window from outside by replacing the focusing binocular. The frame-grabber board PCLL2 (SPINDLER & HOYER) has a resolution of 8 bit which corresponds to 256 grey levels. To reduce the high range of image contrastj a circular continuous density filter is positioned directly in front of the camera lens.
Line Profile Analyses of Rhodium Metal Obtained by Decomposition of Rhodium Carbonyl
Authors: Chandra Dhanesh , Mandalia Himanshu , Garner Michael L. , Blakely Mary Kay , Lau K. H.
Published: July 2019

Metal carbonyls are important for chemical vapor deposition (CVD) of metals and alloys and formation of high surface area metallic particles which have potential applications as catalysts. Rhodium carbonyl [Rh6(CO)16] produces high surface area metallic particles whose structure has been reported as monoclinic (I2/a) with lattice dimensions, a=17.00(±0.03)Å, b=9.78(±0.02)Å, c=17.53(±0.03)Å and β=121°45' ± 30' at room temperature. Generally, metal carbonyl crystals dissociate under vacuum as carbonyl gas and decompose to metallic crystals and carbon monoxide at higher temperatures. However, the behavior of rhodium carbonyl crystals is different; they decompose directly to metallic rhodium without the formation of rhodium carbonyl gas in vacuum. Several residual fine grains of rhodium metal are found after the decomposition in vacuum at relatively low temperatures. The metallic samples of rhodium were obtained from vapor pressure experiments using torsion Knudsen-effusion apparatus. X-ray diffraction analyses performed on these grains showed severely broadened Bragg reflections indicative of small particle size and/or lattice microstrain. In this study, a comparison of lattice strains and domain sizes obtained by integral breadth and Fourier methods has been made. In addition a comparison of the lattice strains and domain sizes has been made between the Cauchy, Gaussian, Cauchy-Gaussian and Aqua integral breadth methods.
X-ray Fractography on Fatigue Fractured Surface of Austenitic Stainless Steel
Authors: Yajima Zenjiro , Tokuyama Hideki , Kibayashi Yasuo , Hirose Yukio
Published: July 2019

X-ray diffraction observation of the material internal structure beneath fracture surfaces provide fracture analysis with useful information to investigate the conditions and mechanisms of fracture. X-ray fractography is a generic name given to this technique.

In the present study, X-ray fractography was applied to fatigue fracture surfaces of austenitic stainless steel (AISI 304) which consisted of solution treatment. The fatigue tests were carried out on compact tension (CT) specimens. The plastic strain on the fracture surface was estimated from measuring the line broadening of X-ray diffraction profiles. 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 the line broadening. The results are discussed on the basis of fracture mechanics.
The Influence of Stress Gradient on X-ray Stress Measurement
Authors: Ohtsuka Masaaki , Matsuoka Hideaki , Hirose Yukio , Ishii Hitoshi
Published: July 2019

The various machine parts made of fine ceramics are usually finished by grinding. The X-ray elastic constants in ground ceramics are measured by the X-ray diffraction method, as a result a measurement error can occur. The cause of the error is the stress gradient in the material produced by the grinding. In the case of material in which a stress gradient is present, X-ray stress measurement data show non-linear 2θφψ- sin2
ψ diagrams. Until now, the X-ray stress measurement by the sin2ψ method makes use of effectively linear 2θφψ - sin2
ψ diagrams. In the case of 2θφψ - sin2
ψ diagrams showing non-linear behavior, however, good analysis method are generally not available.
Crystallinity and Unit Cell Variations in Linear High-Density Polyethylene
Authors: Schwartz Kenneth B. , Cheng Jinlong , Reddy Vijay N. , Fone Matilda , Fisher Howard P.
Published: July 2019

The degree of crystallinity and unit cell parameters have been determined using WAXS on a number of compression molded high-density polyethylene (HDPE) plaques processed at widely varying conditions of crystallization and annealing times and temperatures. Changes in unit cell parameters with variations in processing conditions can be explained in terms of increases in lamellar thickness of polyethylene crystals with increasing thermal treatments. Concomitant increases in the degree of crystallinity of these samples can also be explained in terms of lamellar thickening and other changes in polyethylene morphology. Crystallinity determinations using XRD data are also compared with values determined by differential scanning calorimetry (DSC) and solid-state 13C nuclear magnetic resonance (NMR). Comparisons of crystallinity values obtained by these three different techniques can reveal details of the morphology of HDPE including the presence of an interfacial zone in addition to the crystalline and amorphous components of the system.
Generation of Crystallographic Packing Candidates with Fixed Helical Symmetry and Axial Advance: Application to Pi-2 Polyimide
Authors: Waller J. M. , Eby R. K.
Published: July 2019

A normal coordinate approach was used to generate ciystallographic packing candidates of a multitorsional polyimide synthesized from 3,3′,4,4′-benzophenonetetracarboxylic acid (BTDA) and 2,2-dimethyl-l,3-(4-aminophenoxy)propane (DMDA) (PI-2). Candidates were obtained under conditions of fixed axial advance of 24.6 Å per monomer, and imposed 2/1 helical or 1/0 transiational symmetry, consistent with the observed WAXD meridional layer line spacing [1]. The ability of comb in atori ally generated torsional states to adopt the desired geometry was examined. Necessary corrections to die conformational parameter equations originally derived by Kusanagi, et al. [2|, have been made. The procedure described allowed crystallographic conformations satisfying explicit geometric and MM3 intramolecular energy criteria to be generated for a linear multitorsional polyimide prior to the application of crystallographic screening or refinement procedures.
Appllied Crystallography in the Scanning Electron Microscope Using a CCD Detector*
Authors: Goehner R.R. , Michael J.R.
Published: July 2019

The development of a new charge coupled device (CCD)-based detector for the scanning electron microscope (SEM) has allowed high quality backscattered electron Kikuchi patterns (BEKP) suitable for crystallographic analysis to be collected. These BEKPs can be used for crystallographic texture, phase and microstress analysis. This CCD detector system, can also be equipped with a special filter for removing backscattered electrons, which allows us to image low intensity, highly divergent x-ray diffraction (Kossel) patterns. The Kossel patterns are utilized for the accurate measurement of d-spacings suitable foe residual stress and lattice parameter measurements.
The Characterisation of Microtexture by Orientation Mapping
Authors: Schwarzer R.A. , Zaefferer S. , Kunze K.
Published: July 2019

For a complete description of a material's microstructure the morphology as well as the distributions of chemical elements and of crystal lattice orientations must be known. While morphology is a standard issue of electron microscopy, and element distributions can be mapped readily using an EDX appliance, crystal lattice orientations in the bulk surface are accessible in routine work only recently [1, 2]. Backscatter Kikuchi patterns (BKP), also termed electron backscattering patterns (EBSP), are widely used for the determination of individual grain orientations in the surface of bulk polycrystals.
A New Approach in Performing Microdiffraction Analysis
Authors: Winter D. J. , Squires B. A.
Published: July 2019

Microdiffraction is defined as the x-ray diffraction analysis performed on small samples or small areas of large samples. Since smallness is a relative term, micro diffraction is considered the technique of choice when samples are too small for the optics and precision of conventional instrumentation.
Analysis of Heterogeneous Materials with X-Ray Microfujorescence and Microdiffraction
Authors: Carpenter D. A. , Gorin A. , Shor J. T.
Published: July 2019

The chemistry of heterogeneous materials can be understood only after determining the elements composing the material, the ways in which those elements combine, and the distribution of the resulting phases. The techniques of photon-induced x-ray microfluorescence (XRMF) and x-ray microdiffraction (XRMD) offer several advantages over conventional electron- beam methods for determinations of element and phase distributions. Those advantages include minimal specimen preparation, good element sensitivity, air operation, the capability of wide area coverage, and the availability of sophisticated search/match routines for phase identification.
Development of L-Line X-Ray Fluorescence Instrumentation and its Applications to In-Vivo Measurement of Lead in Bone
Authors: Rosen John E.
Published: July 2019

Initially, Wielopolski (Wielopolskiet al. 1981) used x-rays from either a125I or a105Cd source to estimate lead (Pb) in tibial cortical bone in intact legs, post-mortem. This system utilized the Lα and Lβ x-rays of Pb with energies of 10.5 and 12.6 keV, respectively. The minimum detection limit (MDL) was considered to be comparable with existing K-line x-ray fluorescence (KXRF) instruments, namely, 20-30 ppm. The feasibility of partially polarized radiation (Barkla, 1906) was assessed from a125I source on Pb (No3)2(10,000 ppm) dissolved in wa:er. Reduction of the detector total count rate was observed by a factor of two; and reduction in background by the same factor was appaent. This preliminary study suggested that, with improved design, tlie MDL might be lowered by a factor of five (Wielopolskiet al., 1981).
In Vivo X-Ray Fluorescence of Bone Lead in the Study of Human Lead Metabolism: Serum Lead, Whole Blood Lead, Bone Lead, and Cumulative Exposure
Authors: Cake K.M. , Chettle D.R. , Webber C.E. , Gordon C.L. , Bowins R.J. , McNutt R.H. , Vaillancourt C.
Published: July 2019

Traditionally, clinical studies of lead's effect on health have relied on blood lead levels to indicate lead exposure. However, this is unsatisfactory because blood lead levels have a half-life of approximately 5 weeks (Rabinowitz et al., 1976), and thus reflect recent exposure. Over 90% of the lead body burden is in bone, and it is thought to have a long residence time, thus implying that measurements of bone lead reflect cumulative exposure (Barry, 1975). So, measurements of bone lead are useful m understanding the long-term health effects of lead.
In Vivo XRF Measurements of Heavy Elements: Summary of a Workshop
Authors: Garbauskas M. , Hanson A. L. , Kosnet M. , W Ryon R. , Wielopolski L.
Published: July 2019

This is a brief summary of the first workshop of “In Vivo XRF Measurements of Heavy Elements,” at the Denver Conference on Applications of X-Ray Analysis. In vivo x-ray fluorescence has been applied to medical applications since the 1960's, with much of the pioneering work being done in Sweden (1). First measurements were of iodine in the thyroid. Elements from iron to uranium have now been measured, at natural and elevated levels. Elevated levels occur either unintentionally through occupational or environmental exposure, or intentionally through medical administration. Examples of measurements are cadmium in kidney and liver, platinum in kidneys and tumors, mercury in the wrists and skulls of dentists, lead in various near-surface bones, copper in the eye and iron in skin. Nearly all measurements make use of either silicon or germanium detectors; radioisotopes and less frequently x-ray tubes are used for excitation.
3-D Graphing of XRF Matrix Correction Equations
Authors: Klimasara Anthony J.
Published: July 2019

The Lachance-Traill, and Lucas-Tooth-Price matrix correction equations/functions for XRF determined concentrations can be graphically interpreted with the help of three dimensional graphics. Statistically derived Lachance-Traill and Lucas-Tooth-Price matrix correction equations can be represented as follows:

1

where:

Ci -elemental concentration of element “i”

Ij -X-Ray intensity representing element “i”

Ai0 -regression intercept for element “i”

Ai -regression coefficient

Zj -correction term defined below

2

Ai0, Aj , and Zi together represent the results of a multi-dimensional contribution.

li, Ci, and Zi can be represented in three dimensional Cartesian space by X, Y and Z. These three variables are connected by a matrix correction equation that can be graphed as the function Y = F(X, Z), which represents a plane in three dimensional space. It can be seen that each chemical element will deliver a different set of coefficients in the equation of a plane that is called here a calibration plane. The commonly known and used two dimensional calibration plot is a “shadow” of the three dimensional real calibration points. These real (not shadow) points reside on a regression calibration plane in this three dimensional space. Lachance-Traill and Lucas-Tooth-Price matrix correction equations introduce the additional dimension(s) to the two dimensional flat image of uncorrected data. Illustrative examples generated by three dimensional graphics will be presented.
Digital Spectrum Processing of the Characteristic K-Lines of the Lanthanides
Authors: Smolniakov V. I. , Koltoun I. A.
Published: July 2019

For the decomposition of complex multiplets, which consist of the fluorescent K-series of the lanthanides in the energy range from 30 keV to 60 keV, the procedure of digital filtering of the spectrum data was elaborated using the libraries of real-shape lines. This elaboration was applied to the software for energy-dispersive x-ray fluorescent spectrometers based on Si(Li) and HP Ge planar detectors.

Taking into account the fact that the real shape of line is changed under different count rate, the procedure of spectrum processing has the following principle peculiarities:

- three levels of library of real-shape lines, i.e. the level of high content of fluorescent elements, middle and low contents;

- the regulation of parameters of digital filters;

- use of the nonlinear least squares technique;

Also the estimation of quality of this investigation is given.
Distortion of the Peak Shape Due to the Discrete Sampling of X-Ray Spectra
Authors: Stoev Krassimir N. , DIouhy Joseph E.
Published: July 2019

Accurate and precise evaluation of the peak parameters of the recorded X-ray spectra requires the use of the correct peak shape. Usually, it is assumed that the shape of the X-ray peaks is a Voigt function, i.e., convolution of a Lorentzian distribution function of the emitted X-ray lines with a Gaussian response of the spectrometer, with additional terms for description of the tailing. This assumption is not exactly correct, because it employs a probability density function for description of a discrete signal, while, actually, the measurable parameter is the probability, i.e., the integral of the probability density function over the channel width. In trie present work, the distortion in the peak shape caused by the discrete sampling of the X-ray spectrum is studied and the significance of the introduced errors is evaluated. An improved fitting procedure for evaluation of the peak parameters is proposed.
Trace Analysis by TXRF
Authors: Hockett R. S.
Published: July 2019

Total reflection X-Ray FKiorescence (TXRF) originally was developed for trace analysis of small residues but has become a widespread method for measuring trace surface metal contamination on semiconductor substrates. It is estimated that approximately 100 TXRF instruments are in use in the semiconductor industry worldwide, and approximately half that for residue analysis in analytical laboratories. TXRF instrumentation is available today for reaching detection limits of the order of 109 atoms/cm2. This review emphasizes some of the more recent developments in TXRF for trace analysis, in particular with the use of synchrotron x-ray sources (SR-TXRF). There is some promise of reaching 107 atoms/cm2 detection limits for surface analysis of semiconductor substrates.
Accurate Measurement of Trace Elements Using an Innovative Fixed Goniometer for a Simultaneous Spectrometer
Authors: Kansai K. , Toda K. , Kohno H. , Arai T. , Wilson R.
Published: July 2019

Advancements in trace clement analysis require improvements in both the signal-to-noise ratio and accurate background correction. With a sequential spectrometer, one can obtain detection limits of around 0.1 ppm for medium to heavy Z elements. Conditions can be individually optimized for each element, for example, selection of filters, collimators, crystals and background subtraction. The disadvantage is that the analysis time may become “long” if many elements are to be analyzed. This long exposure time can lead to the deterioration of some samples.
Design of an X-Ray Fluorescence Sensor for the Cone Penetrometer
Authors: Elam W.T. , Gilfrich J. Y.
Published: July 2019

The cone penetrometer is a well-established method for exploring soil types whereby a smalldiameter pipe with a hardened cone tip is pushed hydraulically into the ground. The system can be equipped with sensors to detect soil contamination. We have investigated the development of an x-ray fluorescence (XRF) sensor to be deployed via this system.

The principal uncertainties in the application of XRF to metals detection in the cone penetrometer are the detection limits and the accuracy of a sensor built in such a confined geometry. A laboratory mock-up was constructed to investigate the performance of such a sensor. An x-ray tube operated at very low power was coupled to an electrically cooled Si(Li) detector. The x-ray path lengths were kept short and an aperture and incident x-ray filter similar to those appropriate for a penetrometer sensor were used.

Spectra were collected on a series of Standard Reference Material soils from the National Institute of Standards and Technology consisting of soils with various levels of metal contamination. The detection limits were determined for the metals present in the soils and were comparable to the solid waste regulatory limits. Quantitative measurements were compared to the NIST certified values both without matrix correction and using the fundamental parameters correction method. Results were generally within 10% of the certified values.
Quality Aspects in Selecting, Installing and Maintaining an XRF Spectrometer
Authors: Warren Peter L.
Published: July 2019

The influence of Quality in the laboratory is now all pervading. Increasingly there is a climate which requires laboratories of any reasonable standing to be accredited to the appropriate Quality standard. Within ICI, a number of quality initiatives had manifest themselves- such as GLP1 (Good Lab Practice), BS-57502,TSO-90023, or NAMAS4 (National Measurement Accreditation Service). The latter is a UK body whose accreditation is particularly appropriate to research, analytical and contract laboratories.
Specimen Preparation for X-Ray Fluorescence Analysis of Solutions
Authors: Eksperiandova L.E. , Spolnik Z.M. , Blank A.B.
Published: July 2019

Specimens for x-ray fluorescence analysis (XRFA) were prepared by adding dry gelatine (10%) to the analysis solution, homogenizing the mixture and cooling for 20 minutes. Thus, a compact resilient mass could be formed with the required shape and size; the roughness of the surface was determined by the roughness of the surface on which the specimen was formed, much the same as highly polished. Various calibration methods can be applied in the XRFA of a variety of materials if such specimens are used.
Grammatica philosophica: a um passo da forma
Authors: Alonso Júnior Clóvis Luiz
Published: July 2019

Longe de apresentar a validade do pensamento filosófico aplicado ao desenvolvimento do pensamento gramatical, pretendo aqui esboçar a apresentação de teoria que venho esforçando-me para construir e que se pauta por modo inescapavelmente filosófico de olhar para o objeto Língua. Proponho que esse objeto seja constituído, no conjunto de seu tecido lexical e morfossintático, por metáforas de cunho físico-espacial, por sua vez resultantes de procedimento mimético que a Língua, (sempre) em formação, tenha realizado e venha realizando sobre o espaço físico, desdobrando-se as metáforas ― como lhes é próprio ― em cadeias abstrativas. Postulo que a tradição filosófico-gramatical se tenha aproximado ― e apenas aproximado ― da possível verdade que aí venho pretendendo formular: essa tradição teria estado a um passo do que denomino semântica da estrutura, a um passo da forma.
A review of Convolvulus acanthocladus and its allies in Iran
Authors: EZAZI ATEFEH , GHAHREMANINEJAD FARROKH , RANJBAR MASSOUD
Published: July 2019

The morphology and distribution of Convolvulus acanthocladus and its allies are reviewed. The group consists of C. acanthocladus, C. argyracanthus, C. iranicus and C. spinosus and a new species, C. hormodensis Ranjbar & Ezazi (Convolvulaceae), from Hormozgan province, southern Iran, which is described and illustrated. The paper highlights the macro- and micro-morphological differences between the five species and shows the value of trichome characters in distinguishing between species. The paper is illustrated with tables and photographs.