Home About us Contact
|
Home About us Contact | ||
|
|
||
Dispersive X-ray Spectrometry (dispersive + x-ray_spectrometry)
Kinds of Dispersive X-ray Spectrometry Selected AbstractsPreparation of shuttle-like Sb2S3 nanorod-bundles via a solvothermal approach under alkaline conditionCRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2010Ling Zhang Abstract Uniform shuttle-like Sb2S3 nanorod-bundles were synthesized via a polyvinylpyrrolidone (PVP) assisted solvothermal approach under alkaline condition, using antimony chloride (SbCl3) and thiourea (CH4N2S, Tu) as the starting materials in ethanol. The phase structure, composition and morphology of the product were characterized by means of X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). XRD and EDS results confirm that the synthesized Sb2S3 nanorod-bundles have an orthorhombic structure and an atomic ratio of 3:2 for S:Sb. TEM and HRTEM results show that the shuttle-like Sb2S3 bundles are composed of nanorods with a size distribution of 20-40 nm and growing along c-axis. Furthermore, experiments under different reaction conditions were carried out and the mechanism for the growth of nanorod-bundles was discussed (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Application of otolith microchemistry to estimate the migratory history of Japanese eel Anguilla japonica on the Sanriku Coast of JapanJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2004A. Kotake Summary The age and migratory history of the Japanese eel, Anguilla japonica Temminck & Schlegel, collected in Miyako Bay along the Sanriku coast of Japan, was examined using the otolith microstructure and analysis of strontium (Sr) and calcium (Ca) concentrations conducted with wavelength dispersive X-ray spectrometry by an electron microprobe. The line analysis of Sr : Ca ratios along the life history transect of each otolith showed a peak (ca. 15,17 × 10,3) which corresponded with the period of their leptocephalus and early glass eel stages in the ocean. The mean Sr : Ca ratios from the elver mark to the otolith edge indicated that there were eels with several general categories of migratory history, including sea eels that never entered freshwater (average Sr : Ca ratios, ,6.0 × 10,3), and others that entered freshwater for brief periods but returned to the estuary or bay. This evidence of the occurrence of sea eels in this northern area indicates that Japanese eels of the Sanriku coast do not necessarily migrate into freshwater rivers during recruitment as do glass eels at the beginning of their growth phase; even those that do enter freshwater may later return to the marine environment. Thus, anguillid eel migrations into freshwater are clearly not an obligatory migratory pathway, but rather a facultative catadromy with seawater or estuarine residents as an ecophenotype. [source] Transfer of metallic debris from the metal surface of an acetabular cup to artificial femoral heads by scraping: Comparison between alumina and cobalt,chrome headsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Chong Bum Chang Abstract We aimed to investigate the transfer of metal to both ceramic (alumina) and metal (cobalt,chrome) heads that were scraped by a titanium alloy surface under different load conditions. The ceramic and metal heads for total hip arthroplasties were scraped by an acetabular metal shell under various loads using a creep tester. Microstructural changes in the scraped area were visualized with a scanning electron microscope, and chemical element changes were assessed using an energy dispersive X-ray spectrometry. Changes in the roughness of the scraped surface were evaluated by a three-dimensional surface profiling system. Metal transfer to the ceramic and metal heads began to be detectable at a 10 kg load, which could be exerted by one-handed force. The surface roughness values significantly increased with increasing test loads in both heads. When the contact force increased, scratching of the head surface occurred in addition to the transfer of metal. The results documented that metallic debris was transferred from the titanium alloy acetabular shell to both ceramic and metal heads by minor scraping. This study suggests that the greatest possible effort should be made to protect femoral heads, regardless of material, from contact with metallic surfaces during total hip arthroplasty. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Microscopic Structure of Opalescent and Nonopalescent PecansJOURNAL OF FOOD SCIENCE, Issue 7 2003L.T. Wakeling ABSTRACT: The ultrastructure of pecans was investigated using light microscopy, environmental scanning electron microscopy, scanning electron microscopy, and transmission electron microscopy. Specific methodology for the sample preparation of pecans for electron microscopy investigations was developed. Electron microscopy of the ultrastructure of opalescent (discoloration of the interior) and nonopalescent kernels revealed that cellular damage was occurring in opalescent kernels. The damage was due to cell wall and membrane rupture, which accounted for the release of oil throughout the kernel. This rupture is due to the lower level of calcium in the cell membranes of opalescent pecans, as shown by energy dispersive X-ray spectrometry, making them more susceptible to damage. [source] The Characterization of Automobile Body Fillers,JOURNAL OF FORENSIC SCIENCES, Issue 1 2008Sara C. McNorton M.S. Abstract:, Body fillers are sometimes encountered with paint evidence from hit-and-run accidents. Little forensic research has been conducted and published on the subject since 1986. The objective of this study was to determine if chemical and physical differences in body fillers from various manufacturers existed and could be identified. Thirty-three samples of light-weight automobile body fillers and spot putties were obtained. The fillers and putties were compared using light microscopy, infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX), and pyrolysis gas chromatography (pyGC). Results from fourier transform infrared spectroscopy analysis placed the samples into five groups and differentiated six samples. Light microscopy placed the samples into one of five color groups. PyGC placed the samples into three groups and differentiated one sample. SEM-EDX placed the samples into four groups and differentiated 13 samples. Using these analysis methods, 19 of the 33 samples could be discriminated. The best discriminatory tool was found to be SEM-EDX. [source] Characterization of pottery from the Republic of Macedonia I: Raman analyses of Byzantine glazed pottery excavated from Prilep and Skopje (12th,14th century)JOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2009Vinka Tanevska Abstract In order to gain some understanding of and to characterize the materials used in Byzantine glazed ceramic finds in the Republic of Macedonia, as well as to obtain information on their manufacturing technology, micro-Raman spectra of 15 representative glazed shards, all dated from 12th to 14th century, were recorded. The elemental composition of the body and glaze of selected shards was obtained by scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDXS). At least 17 different minerals in the ceramic body were identified from the Raman spectra, among which were a variety of feldspars (microcline, albite and sanidine) as well as andradite, apatite and forsterite. According to the identified minerals, locations of the used raw materials in the vicinity of the archaeological sites are proposed. There is a good correlation between the polymerization index derived from the Raman spectra and the lead content obtained from the SEM-EDXS analyses, therefore the firing temperature of the analyzed glazes could be assessed. The SEM-EDXS analyses showed the presence of different coloring agents (Cu, Co, Cr, Sb) as well as opacifying (Sb) and fluxing (Pb) agents in the glaze matrix. The content of P2O5 in the glaze of one of the shards is also discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Structural and mechanical properties of polystyrene nanocomposites with 1D titanate nanostructures prepared by an extrusion processPOLYMER COMPOSITES, Issue 9 2009Polona Umek Polystyrene (PS) nanocomposites with titanate nanotubes and titanate nanoribbons were prepared by an extrusion process at 180°C. Nanocomposites with 1 wt% of nanofillers and pure PS that had also been exposed to the extrusion process were comparatively examined with scanning electron microscopy (SEM), electron dispersive X-ray spectrometry (EDS) mapping, solid state proton nuclear magnetic resonance measurements (1H NMR), tensile tests, and shear creep measurements. SEM images and EDS mapping analysis show that titanate nanoribbons homogeneously distribute at a micrometer length-scale in the PS matrix during the extrusion process. This is not the case for titanate nanotubes, which show a stronger tendency to form clusters. Solid state 1H NMR studies, however, proved that the nanocomposites are inhomogeneous at a nanometric scale where structural components with highly mobile PS molecules coexist with domains of rigid PS molecules. Differences in the 1H spin-lattice relaxation at and above the glass transition temperature Tg = 373 K suggest that nanofillers affect the thermodynamic properties of nanocomposite domains. Only a slight increase in mechanical tensile properties was observed in the case of the nanocomposite containing 1 wt% of titanate nanoribbons (TiNRs) probably reflecting a weak interaction between the polymer matrix and the nanofiller. Nevertheless, our results prove that the use of functionalized TiNRs may, in combination with the extrusion process, represent a very promising starting point for the preparation of TiNR nanocomposites at the industrial level. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] | |||||||||||||