Development of X-ray fluorescence technique for the uranium determination in Mongolian coal, coal ash, and phosphate ore

The results of the determination of uranium in Mongolian brown coal, coal ash, phosphate rock, and technological samples by X-ray fluorescence (XRF) spectrometry are presented. Technological samples were produced from phosphates by chemical treatment. Powder geological samples and Certified Reference Materials (CRMs) were pressed as tablets. For chosen conditions of the sample preparation procedure analytical figures of merit were carefully studied, as exemplified by the rock and uranium ore Reference Materials. The variance of the total uncertainty is 2 % for uranium in the analyzed samples, and one is 7 % in the rock CRMs. The estimated values of the uranium detection limit for the CRMs are within the interval from 1 to 3 ppm. For the correction of the matrix effects the background standard method was used. Values of the uranium contents in the studied samples vary within the interval from 3.0 to 35.0 ppm. The comparison of the wavelength dispersive (WD) XRF results with the energy dispersive (ED) XRF results and the neutron activation analysis (NAA) was performed. It is demonstrated that the WDXRF have satisfactorily agreed with the EDXRF results and the NAA within the limits of the uncertainty. It is shown that the values of the relative discrepancies between the WDXRF and EDXRF results are in the range of 2.0-18.0 %, and between the WDXRF and the NAA results are in the range of 2.0-20.0 %. These values are less than 30 %, yielding the third category of the precision of the mineral raw material analysis

Characterization of Roman glass tesserae from the Coriglia excavation site (Italy) via energy-dispersive X-ray fluorescence spectrometry and Raman spectroscopy

The combined use of handheld energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and micro-energy-dispersive X-ray fluorescence spectrometry permitted the characterization of Roman glass tesserae excavation from the Coriglia (Italy) archeological site. Analyses of ten different glass colors were conducted as spot analyses on intact samples and as both spot analyses and line scans on select cross-sectioned samples. The elemental and molecular information gained from these spectral measurements allowed for the qualitative chemical characterization of the bulk glass, decolorants, opacifiers, and coloring agents. The use of an antimony opacifier in many of the samples supports the late Imperial phasing as determined through numismatic, fresco, ceramics, and architectural evidence. And dealinization of the exterior glass layers caused by the burial environment was confirmed

Importation of Obsidian at Cerro Palenque, Honduras: Results of an Analysis by EDXRF

The results of source analysis by EDXRF of obsidian artifacts from the Mesoamerican site of Cerro Palenque in Honduras are reported and changes over time discussed. Sources of obsidian include Ixtepeque, El Chayal, Jalapa, San Martin Jilotepeque, and San Barolome in Guatemala. Some Pachuca obsidian from Mexico was also found. Honduran sources include La Esperanza and La Union. The implications of the obsidian sources are discussed in the context of changes at Cerro Palenque over time as it becomes the largest settlement in the lower Ulua Valley (Sula Valley) in the ninth century AD

Surface and interface study of pulsed-laser-deposited off-stoichiometric NiMnSb thin films on Si(100) substrate

We report a detailed study of surface and interface properties of pulsed-laser deposited NiMnSb films on Si (100) substrate as a function of film thickness. As the thickness of films is reduced below 35 nm formation of a porous layer is observed. Porosity in this layer increases with decrease in NiMnSb film thickness. These morphological changes of the ultra thin films are reflected in the interesting transport and magnetic properties of these films. On the other hand, there are no influences of compositional in-homogeneity and surface/interface roughness on the magnetic and transport properties of the films.Comment: 13 pages, 7 figures, Submitted to Phys. Rev.

An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples

Growth and Yield of Tomato Applied with Silicon Supplements with Varying Material Structures

The effect of varying material structure of silicon (Si) supplements on the growth and yield performance of tomato was investigated. The experimental design consisted of three Si sources (nanosilica, microsilica and sodium silicate) at 5 g/L Si concentration. Among the treatments, nanosilica posted the highest increase in tomato plants\u2019 height increment, fresh weights and dry weights of all plant organs, Si concentrations, and yield. Tomato plants grown with nanosilica had increased height increment and fresh weights of roots, stems and leaves by 23%, 48%, 9% and 22%, respectively. Likewise, dry weight contents among individual organs of plants treated with nanosilica showed 40% and 34% significant increase in roots and stems, respectively. Only nanosilica significantly increased the average fruit yield of tomato by 35% as affected by the 23% increase in the average number of fruits per plant. hence, among the treatments investigated, Si supplementation using nanosilica powder is the most effective in improving the growth characteristics and yield of tomato. Si in root samples supplemented with nanosilica was 72%, 105% and 152% larger as compared to microsilica, sodium silicate and control samples, respectively, which led to the conclusion that the nanostructured scale of silicon supplement contribute to the effective uptake of silicon in the tomato plants, thereby improving growth and yield

Tapada da Ajuda (Lisbon, Portugal) bronze age pin

A pin made of a copper-based alloy, found at Tapada da Ajuda (Lisbon, Portugal), a site dated to the beginning of the Late Bronze Age, was analyzed by X-ray fluorescence (XRF) spectroscopy and examined by microscopy. The results of this study and the unusual manufacturing technique of the pin are presented and discussed in this paper. Typology and production technique of this object seem to indicate a Central European origininfo:eu-repo/semantics/publishedVersio

Effects of Nanosilica Powder from Rice Hull Ash on Seed Germination of Tomato (Lycopersicon esculentum)

open5noNanosilica powders were synthesized from rice hull ash (RHA) and their effects on seed germination of tomato plants were investigated. Synthesized nanosilica powder was subjected to various characterization studies for identification of the size, structure, morphology and elemental composition. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) results showed that the nanoparticles were in agglomerated form with an average diameter of 46.5 nm and 40 nm, respectively. X-ray diffractometry (XRD) indicated that nanosilica powder is amorphous in nature. The nanosilica powder was also characterized as having a purity of 98.33% using EDXRF spectroscopy and having a surface area 172.19 m2 g-1 using the Brunauer-Emmett-Teller (BET) method. The study showed that nanosilica powder significantly improved germination parameters such as germination percentage, germination index, vigor index, mean germination time and average shoot length of tomato but not fresh weight and dry weight. The best results were found at 5gL-1 nanosilica powder. The increase over untreated control seeds was 22% for germination percentage, 47% for germination index, 92% for vigor index and 55% for average shoot length with the addition of 5 gL-1 nanosilica powder. Nanosilica powder-mediated improvement of seed germination in tomato suggests a potential application of nanosilica powder in seed germination of the plant. The study can serve as theoretical basis for further agricultural applications of nanosilica powder.openMaria Morissa Lu, Diana Marie De Silva, Engelbert Peralta, Alvin . Fajardo, Milagros PeraltaMaria Morissa, Lu; DE SILVA, DIANA MARIE; Engelbert, Peralta; Fajardo, Alvin.; Milagros, Peralt