نتایج جستجو برای: روش xrf

تعداد نتایج: 372314  

2007
John R. Sieber Elizabeth A. Mackey Anthony F. Marlow Rick Paul Ryan Martin

The value assignment of candidate Standard Reference Material (SRM) 57b Silicon Metal provided an opportunity to develop an alkali reaction procedure as a precursor to borate fusion for the preparation of test specimens from the metal powder for X-ray fluorescence spectrometry (XRF). Suggested for this purpose by Blanchette (Adv. X-Ray Anal., 45, 415, 2002), the alkali reaction uses LiOH·H2O to...

Journal: :Clinical chemistry 2000
T M Ambrose M Al-Lozi M G Scott

The assessment of past chronic lead exposure is difficult. Chronic lead burden is not always correctly assessed using laboratory-based tests that are useful for acute or recent exposures. We describe a case of suspected chronic lead exposure that illustrated the need for improved and possibly noninvasive methods to determine cumulative lead body burden. X-Ray fluorescence (XRF) is discussed as ...

Journal: :Biomarkers : biochemical indicators of exposure, response, and susceptibility to chemicals 2016
Aaron J Specht Yanfen Lin Marc Weisskopf Chonghuai Yan Howard Hu Jian Xu Linda H Nie

Childhood lead (Pb) poisoning remains a global issue, especially in industrial areas. In this study, 115 children with average age 5.7 years were recruited as either patient diagnosed with Pb poisoning or controls at Xinhua Hospital in China. The subjects' bone Pb was measured with a K-shell X-ray fluorescence (KXRF) and a portable X-ray fluorescence (XRF) system. A significant correlation betw...

2014
Marco Leona Pablo S. Londero John R. Lombardi

The identification of organic colorants in works of art has traditionally been one of the most difficult challenges in cultural heritage science. While non-invasive methods such as X-Ray fluorescence spectrometry (XRF), or Raman microscopy are extremely useful for the identification of inorganic pigments, they remain generally unsuitable for the analysis of most organic colorants. The absence o...

Journal: :Environmental research 2001
A C Todd R Buchanan S Carroll E L Moshier D Popovac V Slavkovich J H Graziano

In vivo bone lead measurements with 109Cd-based K-shell X-ray fluorescence (XRF) have been used to assess long-term lead exposure in adults. Tibia lead levels were measured in 210 children (106 boys, 104 girls) of 11-12(1/2) years of age in a lead smelter town and in a control (nonexposed) town. Tibia lead levels, methodological uncertainties, and models of some of the factors influencing them ...

2005
K. Tsuji T. Emoto Y. Matsuoka Y. Miyatake T. Nagamura X. Ding Xin Jie Kou Wai Da Jie

A new micro-XRF instrument was developed in combination with an atomic force microscope (AFM). A small pinhole of 5 or 10 μm was made on the AFM cantilever. The center of the micro X-ray beam generated by a polycapillary X-ray lens was passed through the pinhole. The present experiment demonstrated that the size of the original X-ray beam of 48 μm produced by the polycapillary lens was reduced ...

1998
Xianguan Long Ning Huang Taihua Li Fuqing He Xiufeng Peng

An artificial neural network approach was used for the analysis of low-resolution XRF spectra. Instead of peak analysis and fitting the experimental results to a mathematical function as used by the conventional algorithms, the artificial neural network method takes the spectrum as a whole, comparing its shape with the patterns learned during the training period of the network. This method was ...

2014
Myriam Eveno Elisabeth Ravaud Thomas Calligaro Laurent Pichon Eric Laval

Introduction: Giotto (1266–1337) and his workshop realized c. 1315 the large Crucifix now in the Louvre Museum. The conservation of this masterpiece in 2010–2013 in the C2RMF studios gave the opportunity for a comprehensive investigation of the execution technique through a characterization of the paint layers. The first examinations revealed an original gilding and decoration surrounding the C...

2008
Justin Domke

Conditional Random Fields (CRFs) encounter computational difficulties in the presence of a graph with high treewidth. This paper introduces a new type of model, the Crossover Random Field (XRF), designed to cope with these difficulties. An XRF consists of a sequence of “layers”, each of which is a tractable CRF. Inference of marginals takes place layer by layer, with the marginals from one laye...

2007
I. Lima M. J. Anjos M. L F. Farias D. Rosenthal R. T. Lopes

Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabeculae region. For that purpose, it was used an XRF beam line at the Synchrotr...

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