5,092 research outputs found

    The use of high resolution graphite furnace molecular absorption spectrometry (HR -MAS) for total fluorine determination in extractable organofluorines (EOF)

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    Acknowledgment A.A. would like to thank the Ministry of Education and University of Jeddah in Saudi Arabia through the Cultural Bureau of Saudi Arabia, London for their financial support during the study period. A.O. wishes to thank the Royal Society of Chemistry Analytical Trust Fund for funding. M.S. would like to thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq for the financial support. L.S., J.B. and J.F. thank Formas for financial support (Grant number 2013–00794).Peer reviewedPostprin

    Analysis of Phosphate Salts Mixtures by a Simple Visual Alkalimetric Titration

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    This article discusses the issue of determining the composition of mixtures of sodium and/or potassium monobasic, dibasic and tribasic phosphate salts with the purpose of addressing, in an educational environment, intriguing features of Acid-Base chemistry. Within this context, a laboratory experiment, based on the alkalimetric titration of solutions obtained by dissolving the mixtures in an excess of strong acid, is presented and its significance is fully examined. This experiment can smoothly be integrated within first-year undergraduate general chemistry/analytical chemistry laboratory, but might as well be interpreted as a virtual experiment for classroom discussion

    Guiding the Development of Efficient and Durable Electrodes for Electrochemical Energy Conversion Applications through Advanced Ion Beam Analysis

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    Surface-sensitive ion beam techniques, such as Secondary Ion Mass Spectrometry (SIMS) and Low-Energy Ion Scattering (LEIS), are making significant contributions to further our understanding of the materials’ performance and the degradation processes that occur under operating conditions. In this contribution, we explore how recent instrumental developments and analytical approaches have boosted the application of these powerful techniques for the characterization of surfaces and interfaces in energy conversion and storage devices.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Collaboration in Iranian Scientific Publications

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    This study looks at international collaboration in Iranian scientific publications through the ISI Science Citation IndexÂź (SCI) for the years 1995-1999, inclusive. These results are compared to and contrasted with the earlier findings for the periods covering 1985-1994 (Osareh & Wilson 2000). The results of Iran's increasing productivity over a 15-year period are presented. Iran doubled its output in the first two five-year periods and increased 2.8-fold from the second to the third five-year period. The rise in Iran's scientific publication output is due mainly to factors such as the ending of the war, better economic conditions, recent changes in the Iranian government's policy, basic changes in the political environment brought about by the Reformers, expansion of the Iranian presses for national publications, and the recent return of a large number of students trained overseas through government scholarships. External changes also account for the increased productivity, e.g., the acceptance of three Iranian source journals by the SCI, increased access to international databases through the Internet and better electronic communication facilities for international collaboration. One of the most important and significant factors that caused this dramatic rise seems to be the government's research policies in the last few years. Since 1999, the Iran Science, Research and Technology Ministry, has encouraged researchers to publish their non-Farsi language articles in highly ranked international scientific journals, for example, by giving prizes to researchers who publish their articles in ISI-ranked journals

    Sensitive detection of methane at 3.3 ÎŒm using an integrating sphere and interband cascade laser

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    Detection of methane at 3.3ÎŒm using a DFB Interband Cascade Laser and gold coated integrating sphere is performed. A 10cm diameter sphere with effective path length of 54.5cm was adapted for use as a gas cell. A comparison between this system and one using a 25cm path length single-pass gas cell is made using direct TDLS and methane concentrations between 0 and 1000 ppm. Initial investigations suggest a limit of detection of 1.0ppm for the integrating sphere and 2.2ppm for the single pass gas cell. The system has potential applications in challenging or industrial environments subject to high levels of vibration

    Analytical Chemistry in Food Science

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    Analytical chemistry presents a traditional and important tool in food science. Its development grew out of governmental food control to verify food composition and wholesomeness. In modern food chemistry, analytical methods are applied to study food constituents, additives and contaminants and their interactions and reactions during processing and storage. Research activities of the Food Chemistry group at ETH comprise investigations on carbohydrates and on chiral flavour compounds. Experimental work in food technology relies on simple analytical methods that are suitable for large series of processing trials. Such methods are used by the Food Technology group to optimize lipid stability of heat sterilized meat and hot-air roasted nuts. Analytical chemistry is taught at ETH in lectures and laboratory courses to all food science majors

    Synthesis of chitosan-based resins modified with tris(2-aminoethyl)amine moiety and its application to collection/concentration and determination of trace mercury by inductively coupled plasma atomic emission spectrometry

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    A novel chitosan-based chelating resin modified with tris(2-aminoethyl)amine moiety (CCTS-TAA) was synthesized. and its characteristics in the collection/concentration of mercury was examined. The synthesized resin showed good adsorption toward mercury in a wide pH range, and the adsorbed mercury can be easily eluted by using 2 M HNO3 without any addition of complexing agent. The resin was then packed in a mini-column and the mini-column was installed on a computer-controlled automated-pretreatment (Auto-Pret) system coupled with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for on-line mercury collection and determination at trace level.</p

    Flow injection determination of readily assimilable nitrogen compounds during vinification

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    A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements
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