MULTI-PEAK MATCH INTENSITY RATIO METHOD OF QUANTI-TATIVE X-RAY DIFFRACTION PHASE ANALYSIS

A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.

AN INCREMENTAL METHOD OF X-RAY DIFFRACTION QUANTITATIVE PHASE ANALYSIS OF SAMPLESCONTAINING AMORPHOUS MATERIAL

A new method for quantitative X-ray diffraction phase analysis of a powder misture has been developed according to Popovic's doping method. The weight fraction of amorphous material in the analysed sample is obtained. For a multicomponent system in which (n-2) pure phases are added into an n-phase compnent sample and theweight fractions of all n phases can be determined by the method. The test results of confirmation agree well with the theory.

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus,The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

A SOLUTION OF MINIMUM NORM FOR QUANTITATIVE PHASE ANALYSIS BY STANDARDLESS X-RAY DIFFRACTION

A new expression of quantitative phase analysis by standardless X-ray diffraction has been derived using intensity matrix of vector modulus.The criterion of standardless X-ray diffraction analysis was suggested,so as to separate the diffraction pattern of every phase from that of sample.The optimal solution could be obtained by the least squares regression.

THE DEGREE OF CRYSTALLINITY OF MULTICOMPONENT POLYMERS BY X-RAY DIFFRACTION ANALYSIS

Based on the X-ray scattering intensity theory,the correction factors of the degree of crystallinity formulae of the multicomponent polymers have been clearly defined.The formula of degree of erystallinity of the multicomponent polymers was derived in terms of the WAXD theory ahd improved graphic multipeak resolution methods.The results calculated are compatible with the density measurement.

Simulation of X-ray Diffraction Line Broadening Caused by Stress Gradients and Determination of Stress Distribution by Fourier Analysis

Different physical, mechanical and chemical processes, such as： ion implantation, oxidation, nitridation and others create on the surface of materials residual stress state, characterized by high level and strong gradient. X-ray diffraction method widely used for stress measurements has some difficulties in interpretation of experimental data, when the depth of X-ray penetration is compared with thickness of surface layer where inhomogeneous stress distribution is localized. Early it has been shown by authors that diffraction line broadening occurs when analyzed surface is characterized by strong gradient. The interest to study the diffraction line broadening is connected to the possibility of obtaining information about parameters of surface stress distribution. In the present paper the convolution and deconvolution concepts of Fourier analysis were applied to study X ray diffraction line broadening caused by surface stress gradients. Developed methodology allows determining of stress distribution in superficial layers of materials.

Investigation of Changes in the Fine Structure of Graphitizing Carbon Materials during Heat Treatment by X-Ray Diffraction Analysis

The properties of synthetic graphite materials, widely used in advanced fields, are determined by their structure, which is formed in the process of high-temperature (~2500°C) heat treatment. The fine structure of a graphitizing carbon material based on petroleum coke containing 1.3 wt% S at various stages of graphitization was studied by X-ray diffraction analysis. Some of the samples contained the addition of dispersed Fe2O3. It is shown that the heat-treated material in the range 1200°C - 2600°C is heterogeneous, its component composition is determined by the processing temperature and the presence of Fe2O3 additive. The observed dependence of the component composition on the heat treatment temperature suggests that the process of graphitization of the carbon material, apparently, develops through a number of metastable states.

AN EXTERNAL STANDARD METHOD OF QUANTITATIVE PHASE ANALYSIS OF THE SAMPLE CONTAINING AN AMORPHOUS PHASE BY X—RAY DIFFRACTION

A new method of the quantitative phase analysis of the sample containing an amorphous phase or a standardless phase by X-ray diffraction is proposed in the paper. The addtion of a reference phase or some analytical phase to the analyzed sample is not required in this method and the experimental results are satisfactory.

X-ray peak profile analysis of dislocation type,density and crystallite size distribution in cold deformed Pb-Ca-Sn alloys

The density,nature of the dislocations and distribution of the domain sizes in cold-deformed Pb-Ca-Sn solid solution were determined by X-ray diffraction profile analysis.The dislocation densities are of the order of 1010 cm-2.The strain broadening of diffraction profiles was accounted for by dislocation contrast factor.The coherent domain size was determined by the recently developed PM2K software package.Assuming that the domain size distribution is log-normal,the distribution function（median μ and variance σ） was calculated from the size parameters determined from X-ray diffraction profile analysis.

DATA PROCESSING OF UNIVERSAL QUANTITATIVE METHOD IN STANDARDLESS X-RAY PHASE ANALYSIS

Accuracy of coeffcient A_(isp) is related to the reference phase chosen during analysis. The cri- terion of choosing reference phase which may minimize the error of A_(isp) was deduced. The optimum results could be obtained by using the method of least squares if the number of sam- pies for analysis is more than the phase in samples. The procedure presented here is satisfacto- ryfor ordinary phase analysis.

X-Ray Powder Diffraction: Why Not Use CuKβ Radiation?

CuKβ radiation with a wavelength of λ = 1.3923 ? is recommended for crystal structure determination from X-ray powder diffraction using the Rietfeld method. A highly sensitive image plate detector is able to collect enough intensity to record a brilliant X-ray powder pattern in a reasonable time, compared to CuKα1 radiation used today. Especially atomic displacement coefficients could be determined more precisely with the much greater number of reflections recorded. A double-radius Guinier camera attached to a micro-focus rotating anode tube ensures increased brilliance besides high resolution. A simple construction specification is presented to make smart cylindrically bent Ge(111) or Si(111) X-ray monochromators that deliver focused CuKβ radiation. The highly linear response of image plate detectors allows removing of fluorescence radiation simply as background of the pattern. The proposed equipment is a cost-efficient alternative to a liquid gallium-metal-jet X-ray source with maximum power load and a similar wavelength of λ(GaKα1) = 1.34013 ?.

A New Method for Clay Mineral Analysis and Its Application in Geology

X-ray diffraction (XRD) peaks in a low-angle diffraction section of clayminerals, especially those of authigenic origin, have broadening and tailing features in shape.Using the five basic parameters, peak position, peak height, width, shape coefficient and asymmetry,to describe an XRD peak is more accurate, comprehensive and integrated than using only 3 of them,position, height and width. Following the concept of the five basic parameters of an XRD peak, theprogram Decoform proposed in this study provides more information in mineralogical analyses byfitting actual XRD profiles. In combination with the HW-IR plot, Decoform can he systematically andaccurately used in the comprehensive analyses of crystallinity, domain size, lattice strain andquantitative phase. It is also of value for the geological investigations of diagenesis,metamorphism, basin maturity, structural stress field and so on.

Image Analysis in Microbiology: A Review

This review is focused on using computer image analysis as a means of objective and quantitative characterizing optical images of the macroscopic (e.g. microbial colonies) and the microscopic (e.g. single cell) objects in the microbiological research. This is the way of making many visual inspection assays more objective and less time and labor consuming. Also, it can provide new visually inaccessible information on relation between some optical parameters and various biological features of the microbial cul-tures. Of special interest is application of image analysis in fluorescence microscopy as it opens new ways of using fluorescence based methodology for single microbial cell studies. Examples of using image analysis in the studies of both the macroscopic and the microscopic microbiological objects obtained by various imaging techniques are presented and discussed.

Structural Analysis of Eu_2Mn_(2/3)Ta_ 4/3O_7 with a Pyrochlore-Related Structure

Eu 2Mn 2/3Ta 4/3O 7 specimen was synthesized from Eu 2O 3, MnO and Ta 2O 5 in a reducing atmosphere. Structure analysis was carried out by Rietveld method from X-ray diffraction data. The X-ray diffraction profile calculated with monoclinic C2/c model was in a good agreement with the observed X-ray diffraction patterns since several small peaks of super lattice could be also assigned with C2/c symmetry in addition to fundamental reflection peaks. Eu 2Mn 2/3Ta 4/3O 7 has two kinds of distorted (Mn, Ta)O 6 octahedra and HTB layers, which deviates from the regular forms. Europium atoms coordinate to eight or seven oxygen atoms and lead to two kinds of polyhedra, EuO 8 and EuO 7 in this compound.

An experimental inter-comparison of radiotherapic dosimetric delivery to assess X-Ray linear accelerator output characteristics

The dosimetric inter-comparison studies carry pertinent significance to ensure uniform radiation dose delivery for clinical trials. This paper investigates the comparative performance analysis of an X-ray high power linear accelerator per- formed by the International Dosimetry Survey Mission and Institute of Nuclear Medicine ＆ Oncology （INMOL）, Lahore. The measurements were made using cylindrical ionization chambers based on the International Atomic Energy Agency （IAEA） TRS-398 protocol for absorbed dose-to-water dosimetric standards, and the percentage deviation was found to be between 0.5 % - 1%. The dosimetric analysis concerning linear X-ray accelerator output performed by INMOL, Lahore was found to be in good agreement with the results of IAEA Dosimtery Survey Mission.

Leaching behavior of phosphorous compounds from sewage sludge ash based on quantitative X-ray diffraction analysis

Phosphorus(P)is an essential and limited resource.Incineration sewage sludge ash(ISSA)contains a high amount of P,which can be recovered using chemical leaching methods.However,the recovery ratio depends on the speciation of P and the leaching conditions.In this study,hydrochloric acid was used as a leaching agent,and the effects of the hydrochloric acid concentration,leaching time,temperature,and liquid-solid ratio on the P leaching ratio were investigated.Furthermore,the co-leaching of macro-metals Ca,Al,Fe,and Mg was analyzed.The results showed that P leached rapidly within 30 min,where the leaching rate reached more than 80%and then gradually stabilized.The leaching concentrations of Ca and Mg had a significant correlation(correlation coefficient r^(2)>0.90),and both were leached completely.Al and P had similar leaching patterns,where the leaching rates increased initially and then decreased with time at 0.2 mol/L HCl.According to X-ray diffraction analysis and Rietveld refinement,the P in ISSA was mainly present in the forms of Mg_(3)Ca_(3)(PO_(4))_(4) and AlPO_(4).When leached using 0.2 mol/L HCl at 55℃ with a liquid-to-solid ratio of 20 L/kg,the AlPO_(4) and Fe_(3)(H_(2)O)_(3)(PO_(4))_(2) in ISSA dissolved initially and then precipitated on the surface of the solid phase,thereby impeding further P leaching.

SEPARATION OF DIASTEREOISOMERSNEOCLAUSENAMIDE AND ISONEOCLAUSEAMIDE AND X-RAY DIFFRACTION ANALYSIS

Neoclausenamide with lowering effect on the elevated SGPT levels was isolated from leaves of Clausena Lansium (lour) Skeels. Its content in the plant is less than 0.01%. For more intense pharmacological studies, larger amount of

Study on the distribution of residual stresses in linear friction welds of Ti6AI4V

The linear friction welding process of Ti6Al4 V was modeled and computed ,for obtaining the residual stresses. Temperature, stress and strain fields were simulated, based on which, the residual stresses were also cah＇ulated. Simulated resttlts showed that the longitudinal residual stresses were tensile stresses at the bonding interface, and decreased rapidly with the increase of the distance from the bonding interface until turned into compressive stresses. The compressive stresses decreased slowly as the distance increased, and approached to zero finally. The distribution of the transverse residual stresses was similar to that of the longitudinal residual stresses, but showed much smaller values. The residual stresses in one linear friction weld were measured by an X-ray diffrnctometer. The average valwe of errors between computed and measured results was 14. 5 %.

X-RAY RIETVELD STRUCTURE REFINEMENT OF ErNiSb

The crystal structure of compound ErNiSb has been refined by the Rietveld wholepatternfitting method from X-ray powder diffraction data.The compound ErNiSb is cubic, space group F43m and the structure parameters and reliability factors were refined to be a=6.268 3(1), V=246.29^(3), Z=4, D_(x)=9.377 g/cm^3, R_(B)=3.57%, R_(F)=3.64%, R_(p)=6.63%, R_(WP)=8.80%.

Growth, Crystal Structure and Characterization of a New Single Crystal: Lithium Sodium Acid Phthalate (LiNaP), for Third Order Nonlinear Optical Applications

A new alkali metallo-organic single crystal of Lithium Sodium Acid Phthlate (LiNaP) complex has been synthesized from aqueous solution in the equimolar ratio 3:1:2. Transparent and bulk single crystals of dimension 9 × 4 ×2 mm3 have been grown from the conventional slow-cooling technique. The crystal structure of the compound has been solved from single crystal X-ray diffraction. The compound 2[C8H4O3]4-Li3+Na+ crystallizes in triclinic system with a space group of Pī having cell dimensions a = 7.5451(2) ? b = 9.8422(3) ? c = 25.2209(7) ? α = 80.299(2);β = 89.204(2);γ = 82.7770(10). FTIR measurement was carried out fo? LiNaP to study the vibrational structure of the compound. The various functional groups present in the molecule and the role of H-bonds in stabilizing the crystal structure of the compound have been explained. Optical absorption properties were studied for the grown crystal using UV-Vis-NIR spectrum. Thermal measurements were carried out for LiNaP to determine the thermal strength as well as to ascertain the hydrated nature of the crystal. Third order nonliner optical studies have also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results of all studies have been discussed in detail.