bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single pass major element x‐ray fluorescence analysis of silicate rock samples using a Philips 1212 spectrometer
Authors: Parker R. J. 
Published: May 2005

AbstractA ‘single pass’ method of analysing silicate rocks for their major element composition has been developed using a Philips 1212 x‐ray fluorescence spectrometer. Samples need only be submitted once to the spectrometer and all ten major elements (SiO2, TiO2, Al2O3, Fe2O3T, MnO, MgO, CaO, Na2O, K2O and P2O5) are determined using a Cr x‐ray tube and three analysing crystals, i.e. TIAP, PET and LiF220. The method has been evaluated in terms of the quality of the calibration lines for each element, the precision of replicated analyses and by the analysis of rock standards as unknown samples. The single pass method is rapid, facilitates on‐line data reduction and is capable of producing high quality analytical data.
A new procedure of powdered sample preparation by melting for x‐ray emission spectrometry
Authors: Novosel‐Radović Vj. , Maljković Da. , Dmitrović R. 
Published: May 2005

AbstractA new procedure of powder sample preparation for x‐ray emission analysis by melting has been worked out in detail. The mixture sample‐flux was melted and cooled in graphite crucible. The resulting glass disk was ready for direct measurement. The re‐fused graphite electrode of an electric arc furnace was used as the material for the graphite crucible. The dimension and shape of the crucible bottom were determined on the basis of sample holder dimension and sample behaviour during the cooling step. The reproducibility of Kα line measurement was below 1%. Resistance of the crucible to handling and the influence of graphite on Fe Kα, Ca Kα, SKα, Si Kα and Mg Kα line intensities also were investigated.
Application of x‐ray microprobe technique to clay minerals: Vermiculite
Authors: Patel M. 
Published: May 2005

AbstractThe usual method of polishing the surface of a solid sample for examination using the x‐ray microprobe technique cannot be adopted for clay minerals. A modified method is suggested and its validity is tested using vermiculite mineral. It is observed that precision of quantitative elemental analysis increases significantly according to the present pretreatment procedure; variation from values obtained by wet chemical method is < 1% for SiO2, MgO and Fe2O3 and 2–3% for the rest. However, values obtained with the x‐ray microprobe technique vary enormously from point to point and this non‐uniformity is explained in terms of the structural characteristics of the clay mineral. The variation increases with the rise in temperature of treatment due to structural modifications occurring during heat treatment. The x‐ray microprobe technique has been found to be quite effective in determination of trace elements such as K and Ti.
A new source configuration for trace analysis of small samples by XRF
Authors: Shenberg C. , Boazi M. , Rapaport M. S. 
Published: May 2005

AbstractA new geometry for a radioactive source was developed for the XRF determination of trace elements in the range 0.1–50 μg in samples with diameters from 2–5 mm. The new set‐up was constructed with five 241Am (45mCi each) point sources. The shielding and configuration of the source, as well as the choice of appropriate collimators in the optimal shapes and dimensions, were investigated in detail. The study was carried out to establish the conditions for obtaining maximum sensitivity. The count rates and signal‐to‐background ratios were compared with those obtained with an annular source and showed an improvement of a factor of ∼2 in the signal‐to‐background ratio and of a factor of 2–9 in the peak intensity for the elements studied (29≤ Z ≤ 47).
Determination of brass composition and plating thickness on brass‐plated wire and cord by x‐ray fluorescence spectrometry
Authors: Ponchon J. L. , Bourrain P. , Palsky A. 
Published: May 2005

AbstractThe control of brass composition and plating weight on brass‐plated steel wire and cord used as reinforcement in tyres is generally carried out by atomic absorption spectrometry, or by polarography. These methods require a mineralization of the sample and the analysis time is very long. On account of this, we have studied a direct analytical method on wires based on x‐ray fluorescence spectrometry. The mathematical method we use suppresses the influence of the cord construction and allows to calculate simultaneously the composition and thickness of the brass coating. The analytical performances, i.e. repeatability, accuracy and analysis time, are better than those prevailing with atomic absorption spectrometry or differential pulse polarography. Moreover, by dispensing with mineralization of the sample, XRFS is particularly well‐fitted for a routine control in production.
A study of mathematical models for XRF spectrometry analysis of copper mattes and slags
Authors: Budesinsky Bret W. 
Published: May 2005

AbstractThe Rasberry‐Heinrich method and its three modifications (delta method, expanded square intensity method and double constant method) together with the Tertian and a strictly empirical method were used for the analysis of copper mattes and slags. The expanded square intensity method, which represents a combination of theory and empiricism, gave the most accurate results.
A new method for matrix corrections by radioisotope excited x‐ray fluorescence
Authors: Hallak A. B. , Saleh N. S. 
Published: May 2005

AbstractA method has been investigated which allows calculations of the absorption correction factors in the energy range 1.0–5.0 keV using 55Fe excitation source. From the experimentally‐measured absorption factors between 6.0 and 20.0 keV using 109Cd excitation source, the coefficients at lower energies with the associated absorption jumps are generated through an iterative procedure.
Surface density measurement of pure element thin films by radioisotope x‐ray fluorescence spectroscopy
Authors: Saleh N. S. , Hallak A. B. 
Published: May 2005

AbstractA method for measuring the surface density of pure element thin films using x‐ray fluorescence and coherent scattering of primary radiation has been developed. The accuracy is greatly improved by intensity ratio measurements where the dependence on the accuracy of the fundamental parameters is eliminated.
A mobile installation for energy‐dispersive multi‐element x‐ray fluorescence analysis for application in the field
Authors: Hoffmann P. , Lieser K. H. , Hofmann T. , Sommer R. 
Published: May 2005

AbstractThe construction of a mobile XRF unit is described. It consists of a radionuclide source (109Cd), shielding, a sample exchanger for powdered samples, a semiconductor detector and an electronic measuring and evaluation system. The disadvantage of the supply of liquid nitrogen or liquid air for the semiconductor detector is avoided by use of a mobile unit for the production of liquid air constructed for this purpose. Numerous measurements were carried out at several location within the Federal Republic of Germany.
The stopping‐power correction in proton‐induced x‐ray emission analysis
Authors: Dyson N. A. , Fakhouri Miss H. 
Published: May 2005

AbstractThe thick‐target yield of characteristic x‐rays from a series of gold–silver binary alloys has been determined experimentally (relative to the yield from the pure elements) under proton bombardment, using proton energies of 1. 5, 2. 0 and 2. 5 MeV. The yield per unit concentration of gold or silver varies with alloy composition because of the progressively varying effects of proton stopping power (specific energy loss) and x‐ray self‐absorption in the target materials. Theoretical yields have been calculated using tabulated data for stopping power and x‐ray absorption. When both of these effects are taken into account, agreement with experiment is satisfactory. These results can be made the basis of stopping power and self‐absorption corrections in proton‐induced x‐ray emission analysis.
Fundamental algorithm between concentration and intensity in XRF analysis 1—theory
Authors: Rousseau Richard M. 
Published: May 2005

AbstractA new formalism is proposed to correct with accuracy the matrix effects in x‐ray fluorescence (XRF) analysis. It has been deduced from Sherman's equations and includes a new algorithm between concentration and intensity, theoretically exact, and explicit expressions permitting the calculation of αij and ρij coefficients that correct for absorption and enhancement effects, respectively. In other words, the concept of correction coefficients is established on a solid theoretical basis. In the second part, it will be shown how to adapt this new formalism to practical situations. From an estimate of composition calculated by the Claisse–Quintin algorithm and an appropriate calibration, the new algorithm is used to refine the estimated composition for greater accuracy. This last approach is equivalent to the ‘fundamental parameters’ method but is presented in a simpler version adaptable to any mini‐computer.
Spectral intensity distributions from x‐ray tubes. Calculated versus experimental evaluations
Authors: Tertian R. , Broll N. 
Published: May 2005

AbstractApart from their general importance, an accurate definition of spectral intensity distributions from x‐ray tubes is required to support the development of mathematical matrix correction procedures for x‐ray fluorescence analysis. Since a direct measurement is costly, time consuming and occasionally difficult, and a purely theoretical approach is not suitable for current utilization, a simple, readily adaptable calculation procedure is very desirable. Concerning the continuum or white radiation from the x‐ray tube, such an evaluation was worked out by effecting (1) a modification to Kramers' law and (2) a refinement of the absorption correction regarding the absorption by the target itself. The new equation accounts very closely for the best known, carefully measured and corrected experimental distributions by Brown et al. and Loomis and Keith. Extended experiments are required to ensure systematization, and special steps are needed for the treatment of the characteristic radiation.
Study of some cobalt biomolecular complexes by x‐ray absorption spectroscopy
Authors: Chattopadhyay S. , Sapre V. B. , Mande C. 
Published: May 2005

AbstractThe fine structure in the vicinity of the K absorption edge of cobalt in some cobalt biomolecular complexes has been studied using a bent crystal x‐ray spectrograph of the Cauchois type. The average metal—ligand bond length in these complexes has been determined by applying Levy's theory.
Quantitative analysis of bulk samples without standards by using peak‐to‐background ratios
Authors: Heckel J. , Jugelt P. 
Published: May 2005

AbstractA method is described for the quantitative analysis of bulk specimens without standards by using peak‐to‐local background ratios in energy‐dispersive electron probe microanalysis. Theoretical transport investigations have been used to derive an expression for the absolute determination of (P/B) ratios. Accurate measurement of the background below a peak is carried out without an exact knowledge of the surface geometry of the specimens. The advantages of this method are discussed in comparison with other correction procedures and the efficiency is demonstrated by means of quantitative analysis of nine binary specimens and two steel specimens.
Theoretical evalution of the efficiency of compton scattered radiation method in EDXRF analysis
Authors: Markowicz Andrzej 
Published: May 2005

AbstractA theoretical evaluation of the efficiency of correction for the matrix absorption effect using Compton scattered x‐rays in EDXRF analysis has been carried out for thick samples and for monoenergetic primary radiation. The limitations of this correction method and the procedure for the selection of the optimum excitation energy are presented.
X‐ray fluorescence determination of light rare earth elements, Y and Th, by the fusion technique
Authors: Macháček V. , Weiss D. 
Published: May 2005

AbstractA method for the determination of rare earth elements, Y and Th in raw materials with different matrices is described. The sample is fused with Li2B4O7 and Cr and Mo are added as internal standards. Single elements can be determined in a wide range of concentrations, viz. Ce, Nd, La and Pr from 0.02 to 25% and Sm, Gd, Y, Th and Eu from 0.005 to 1%. The use of the LiF (110) crystal and, possibly, chemical separation, reduces the coincidence of lines to a minimum. Mutual interaction between single elements is prevented by the application of empirical corrections.
Some experience in using the MECA‐10‐44 (XR‐500) x‐ray fluorescence analyser for solving geological problems
Authors: Margolin E. M. , Pronin Yu. I. , Choporov D. Ya. , Shil'nikov A. M. , Komyak N. I. , Goganov D. A. , Serebryakov A. S. , Fed'kov E. A. 
Published: May 2005

AbstractThe excitation conditions have been studied and the accuracy and sensitivity estimated of the MECA‐10‐44 energy‐dispersive x‐ray fluorescence spectrometer, in the determination of contents of 10 major and 25–30 rare and scattered elements in samples of rocks and ores. The use of the instrument for the rapid routine analysis of geological samples for separate groups of elements has been demonstrated; when carrying out combined geochemical investigations, such an instrument represents an essential link in the system of analytical methods applied for complete elemental composition analysis.
Depth profiling of brass by means of PIXE
Authors: Rössiger V. , Lenk M. 
Published: May 2005

AbstractThe PIXE (particle‐induced x‐ray emission) depth profiling technique was applied to brass coatings on steel wire. Applying protons with energies E0 = 100–360 keV from a small electrostatic accelerator, the surface region to a depth of up to about 1 μm can be investigated. Three, or at maximum four, parameters of a suitable model function for the concentration profile were evaluated by analysing the ratio of Cu Kα and Zn Kα experimental x‐ray yields as a function of the primary energy of the particles.
Analyses of barytes by x‐ray fluorescence spectrometry using a fusion method for sample preparation
Authors: Joslin D. , Salt P. D. 
Published: May 2005

AbstractVariation in the composition of commercial sources of barytes (BaSO4) govern its suitability for use in the oilwell drilling industry to control the density of the circulating drilling fluid. A fusion method of sample preparation using GeO2 as a glass‐forming additive has been developed, enabling a 1 part sample to 4.1 parts ‘flux’ composition glass disc to be made for XRF analysis.
Analysis of powders by XRF using the smear technique
Authors: Purdue G. E. , Williams R. W. 
Published: May 2005

AbstractA thin‐film technique has been developed for the quantitative analysis of grindable solids such as combustion chamber and spark‐plug deposits, coal and fuel‐oil ashes, sediments and catalysts. Only 20 mg of sample are required and results are virtually independent of the matrix for all elements of atomic number 11 (Na) and heavier.Detection limits for the 25 elements so far calibrated range betweenf 0.05 and 1.0% by weight. The technique was proved using 22 certified materials, the precision being within 10% relative over much of the calibration ranges.
Least‐squares fits of fundamental parameters for quantitative x‐ray analysis as a function of Z (11 ≤ Z ≤ 83) and E (1 keV ≤ E ≤ 50 keV)
Authors: Poehn Christian , Wernisch Johann , Hanke Wolfgang 
Published: May 2005

AbstractA presentation by useful approximations of fundamental parameters needed for XRF and EPMA is given. The set of fundamental parameters include: critical energy or edge energy, energy of characteristic x‐rays, edge‐jump, fluorescence yield, transition probability, mass absorption coefficient, backscatter coefficient, mean ionisation potential and atomic weight.
Influence of sample thickness, excitation energy and geometry on particle size effects in XRF
Authors: Van Dyck P. , Markowicz A. , Van Grieken R. 
Published: May 2005

AbstractExpressions are presented for calculating the matrix effect and the pure particle size effect in the XRF analysis of particulate samples with a discrete particle size. The equations are based on the absorption‐weighted radiometric diameter concept. Two excitation–detection geometries are considered, with the angles between the sample plane and both the incident and emerging radiation being either 90° (π geometry) or 45° (π/2 geometry). Calculations were made for different sample loadings and exciting radiation energies. The influence of these parameters on the matrix and pure particle size effects is shown. From the results, it is possible to predict the performances of alternative experimental correction procedures for the particle size effect, involving dual measurements at different excitation energies or in different excitation–detection geometries.
X‐ray analysis of nickel‐base alloys with theoretically derived inter‐element correction coefficients
Authors: Griffiths Joyce M. , Webster H. W. M. 
Published: May 2005

AbstractWide‐range calibrations for 16 elements in nickel‐base alloys have been established with theoretical inter‐element correction coefficients. Details of the instrument conditions and line‐overlap corrections are given. A new approach to the specification of the ‘average composition’ used for the calculation of correction coefficients is described. An accuracy superior to that obtained by currently used methods was achieved.
Dependence of the K X‐ray yield on target thickness in the S + Ge collision system
Authors: Bǎdicǎ T. , Ciortea C. , Popescu I. 
Published: May 2005

AbstractMeasurements of the target‐thickness dependence of the target K x‐ray production yields are reported for 1 and 2 MeV/amu Sq+ (q = 6 and 8) ions incident upon thin solid targets of Ge. Target K x‐ray production cross‐sections were extracted in the limit of vanishing target thickness. Comparisons of the data with theoretical estimates based on combinations of direct ionization and electron‐transfer processes are presented.
Application of an x‐ray backscattering method to the analysis of ash from some indian coals
Authors: Narayana D. G. S. , Umamaheswara Rao K. , Venkateswara Rao N. , Satyanarayana G. , Sastry D. L. , Bhargava R. C. , Agarwal S. L. 
Published: May 2005

AbstractAn x‐ray fluorescence technique involving a 30 mCi 238Pu as a source of primary radiation and a two‐channel thin NaI(Tl) crystal spectrometer was developed for the analysis of coal ash samples. The geometry of the source–target–detector assembly is described. The ash content is estimated using an x‐ray backscattering method which includes compensation for iron x‐ray fluorescence. About 120 Indian coal samples were analysed and the results show that the ash content varies from 10 to 40%.
Application of an empirical correction method for the x‐ray fluorescence analysis of copper alloys
Authors: Kovács P. , Kis‐Varga M. 
Published: May 2005

AbstractAn improved energy‐dispersive x‐ray fluorescence analyser has been used in a copper smelting works. An empirical correction program with α parameters according to the Lachance–Traill algorithm has been applied. The concentrations of eight elements in brass, red brass, bronze and albronze have been determined with acceptable accuracies.
XANES study of two bivalent cobalt polymers
Authors: Chattopadhyay S. , Mande C. , Juneja H. D. , Munshi K. N. 
Published: May 2005

AbstractXANES (x‐ray absorption near edge structure) in the vicinity of the K absorption edge of cobalt has been studied for two bivalent cobalt polymers, viz. cobalt(II) azelaic acid bis(phenylhydrazide) and cobalt(II) sebacic acid bis(2,4‐dinitrophenylhydrazide), using a bent crystal x‐ray spectrograph of the Cauchois type. This study helped in the determination of the average bond lengths in the two compounds. The study of the chemical shifts and the edge widths throws some light on the relative covalency in these complexes.
Improved determination of cobalt in steel by x‐ray fluorescence analysis
Authors: Sieber John R. , Pella Peter A. 
Published: May 2005

AbstractA method for improving the determination of cobalt as a minor element in steel specimens is reported. A line overlap correction for the contribution of the Fe Kβ background on the Co Kα peak plus inter‐element matrix corrections is necessary in the determination of Co when standards of varying matrix compositions are used. Co was determined in several NBS SRM steels and values were found that agreed with the certificate values to within 5% relative error in the range 0.005–0.40 wt‐% cobalt.
Effect of relative L‐line intensity ratios on the accuracy of standardless x‐ray microanalysis
Authors: Lábár János L. 
Published: May 2005

AbstractA standardless method for energy‐dispersive x‐ray microanalysis has been implemented. Pure element intensities were calculated from first principles. The spectrum processing and ZAF correction of the unknown spectra were effected by a modified FRAME‐C program. The replacement of the original constant relative L‐line intensities with Z‐dependent new values according to Schreiber and Wims improved the analytical accuracy of the program. The improvement is demonstrated by a better consistency of the measured and calculated L‐line intensities of pure elements and by the reduction of the RMS error from 15.2% to 8.5%, calculated on the basis of 64 analyses of compound standards measuring K and L line intensities.
Precipitation technique to prepare thin‐film standards of lead and zinc for x‐ray fluorescence spectrometry
Authors: Pang Thomas W. S. , D'Onofrio Anthony M. , Lo Francis B. , Arai Douglas K. , Nazar Mark A. 
Published: May 2005

AbstractThin‐film standards of lead and zinc were prepared by precipitating precise amounts of their insoluble salts directly on to polyamide film substrates for the calibration of the x‐ray spectrometer. Samples of different particle deposition characteristics were then prepared and analysed by XRF, atomic‐absorption and inductively coupled plasma atomic‐emission spectrometry. The optimum sizes of thin‐film specimens were selected to be the same as the area of the specimen plane where the average flux of the primary x‐ray beam is fairly uniform. No significant difference in response of the spectrometer to the Zn Kα and Pb Lβ between the samples and the standards were observed. The correlation of the XRF results with those obtained by the other two methods was found to be 1.008±0.029 for lead and 0.995±0.020 for zinc. The amount of metal present ranged from about 5 to 350 μg for lead and from 10 to 600 μg for zinc.
X‐ray fluorescence studies on low‐Z elements of straits chinese porcelains using Fe‐55 and Cd‐109 annular sources
Authors: Yap C. T. 
Published: May 2005

AbstractElemental analysis from Z = 13 (aluminium) to Z = 27 (cobalt) was made on 37 pieces of Straits Chinese porcelains using energy‐dispersive X‐ray fluorescence technique. These porcelains were produced from the beginning of the nineteenth century up to the Republic period (1912–1939) except 4 pieces which were made recently. It was found that manganese, cobalt, potassium and, to a certain extent, iron were correlated in time. All Ch'ing and Republic pieces containing underglazed blue had Mn/Co ratios between 2 and 4 while the modern pieces had Mn/Co ratios of less than 0.07. A plot of the ratio of the intensity of KKα,1 to that of the coherently scattered MnKα from the Fe‐55 source versus the ratio of the intensity of the FeKα,1 to that of the coherently scattered AgKβ from the Cd‐109 source shows that all Ch'ing and Republic pieces cluster together and are quite distinct from the modern pieces. XRF technique therefore provides a simple, fast and, most important of all, non‐destructive method of identifying modern (post World War II) fake reproductions of Straits Chinese porcelains.