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This paper investigates a treated fly ash to act as a synthetic zeolite to remediate soils polluted with heavy metals and metalloids (As, Pb, Cu, Zn, Fe, Cd and Mn). Four types of such 'zeolites' were synthesized by hydrothermal treatment of a calcareous fly ash derived from Greek lignite-fired power plants: two with excess of sodium hydroxide in a solid/liquid ratio of 50 g·L^-1, and two with excess of fly ash in a solid/liquid ratio of 100g·L^-1. Soil samples were obtained from a former mining site at Lavrion, Greece. Mobilization and transfer of metals to the retention agents was effected by using HCI aq 1M, with satisfactory results with respect to As, Pb, Cu, Mn and Cd. The great variety of metal complexes in soil was found to be of major importance for the effectiveness of the overall process. The final products were solidified either on their own, or by using additives such as lime and cement.  相似文献   
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This work focuses on the production of glass and glass-ceramics by using industrial wastes or by-products, e.g., two fly ashes from the combustion of lignite, a slag from the production of Fe-Ni and a slag from the making of steel. Vitrification took place at 1 350°-1450℃ and crystallization was achieved by heat treatment at 900, 950 and 1 000℃. The capability of the waste to be vitrified and subsequently devitrified was determined by XRD techniques. The crystalline phase depends greatly on the structure of the by-product and the heat treatment. The final products showed low leachability and good hardness.  相似文献   
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Museum curators and archaeologists use analytical science to provide important information on artworks and objects. For example, scientific techniques provide information on artwork elemental composition, origin and authenticity, and corrosion products, while also finding use in the day-to-day conservation of many historical objects in museums and archaeological sites around the world. In this work two special cases are being discussed. In the first part of our work, physicochemical studies of an icon on a metal substrate were carried out using non-destructive, qualitative analysis of pigments and organic-based binding media, employing various microscopic and analytical techniques, such as Optical Fluorescence Microscopy, XRF, and Gas Chromatography. In the second part of our work, laser cleaning of late Roman coins has been performed using a Q-switched Nd:YAG laser (1064 nm, 6 ns) and a GaAlAs diode laser (780 nm, 90 ps). The corrosion products have been removed, while we observe increased concentrations in Ag, which is the main material of the silver plating found in late Roman coins.  相似文献   
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Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) has been used to determine the mass of a double-stranded 500 base-pair (bp) polymerase chain reaction (PCR) product with an average theoretical mass of the blunt-ended (i.e. unadenylated) species of 308 859.35 Da. The PCR product was generated from the linearized bacteriophage Lambda genome which is a double-stranded template. Utilization of ethanol precipitation in tandem with a rapid microdialysis step to purify and desalt the PCR product was crucial to obtain a precise mass measurement. The PCR product (0.8 pmol/μL) was electrosprayed from a solution containing 75% acetonitrile, 25 mM piperidine, and 25 mM imidazole and was infused at a rate of 200 nL/min. The average molecular mass and the corresponding precision were determined using the charge-states ranging from 172 to 235 net negative charges. The experimental mass and corresponding precision (reported as the 95% confidence interval of the mean) was 309 406 +/- 27 Da (87 ppm). The mass accuracy was compromised due to the fact that the PCR generates multiple products when using Taq polymerase due to the non-template directed 3'-adenylation. This results in a mixture of three PCR products with nearly identical mass (i.e. blunt-ended, mono-adenylated and di-adenylated) with unknown relative abundances that were not resolved in the spectrum. Thus, the experimental mass will be a weighted average of the three species which, under our experimental conditions, reflects a nearly equal concentration of the mono- and di-adenylated species. This report demonstrates that precise mass measurements of PCR products up to 309 kDa (500 bp) can be routinely obtained by ESI-FTICR requiring low femtomole amounts. Copyright 1999 John Wiley & Sons, Ltd.  相似文献   
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The most widely-used inorganic pigments of Byzantine and post-Byzantine hagiography are earth pigments called ochres such as, red and yellow ochres, limonite, goethite, raw and burnt sienna, caput mortuum and hematite. The present experimental work proposes a technique of differentiation that allows one to distinguish among all the different kinds of iron oxides, thereby providing a better understanding of the painting technique used on portable icons and wall paintings. The ratios between the main spectroscopic peaks, attributable to the major components usually present in ochres, were calculated and compared, one against the another, from the spectra obtained through micro-Raman spectroscopy. Elementary composition is also revealed through a scanning electron microscopy (SEM) analysis. The possibility for detailed study on a particular Byzantine ochre palette can thus be performed based on the small differences in its nature and composition. These differences can first be observed and then measured among all of the natural earth pigments, through microRaman and microFTIR spectroscopies.  相似文献   
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This paper describes the investigation of the potential of a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOF) equipped with an atmospheric pressure ionisation interface for quantitative measurements of small molecules separated by reversed phase liquid chromatography. To this end, the detection limits and linear dynamic range in particular were studied in an LC/MS/MS experiment using 3,4-methylenedioxymethamphetamine standards and 3,4-methylenedioxyethylamphetamine for internal standardisation. In a second phase, the experiment was repeated with real biological extracts (whole blood, serum, and vitreous humour). A calibration for 3,4-methylenedioxymethamphetamine and its metabolite 3,4-methylenedioxyamphetamine was prepared in each of these matrices again using 3,4-methylenedioxyethylamphetamine as internal standard. The resulting quantitative data were compared with those obtained by liquid chromatography with fluorescence detection for the same extracts. The Q-TOF results revealed excellent sensitivity and a linear dynamic range of nearly four decades (2-10 000 pg on-column, r(2) = 0.9998, 1/x weighting). Furthermore, all the calibration curves prepared in biological material were superimposable, LC/MS/MS and LC-fluorescence, and the quantitative results for actual samples compared very favourably. It was concluded that the Q-TOF achieves a linear dynamic range for quantitative LC/MS/MS work exceeding that of fluorescence detection and at much better absolute sensitivity. Copyright 1999 John Wiley & Sons, Ltd.  相似文献   
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Steroid determination by immunoassays results in significant interferences and inaccurate results. This study describes the development and validation of a new gas chromatographic-mass spectrometric method for the simultaneous quantification of 17alpha-hydroxyprogesterone (17alphaOHP), testosterone (T), dehydroepiandrosterone (DHEA), androstenedione (Delta4-A), cortisol (F) and pregnenolone (Preg) in serum of neonates. Steroids were extracted and purified from 0.5 mL serum using diethyl ether and Extrelut mini NT1 column. The extracts were derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA)/trimethylsilyl iodide (TMSI)/dithioerythritol (DTE) and the resulting trimethylsilyl derivatives were quantified by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS). The detection limit for all steroids was lower than 0.1 ng/mL. The limit of quantification was 0.1 ng/mL for all steroids except cortisol which was at 0.25 ng/mL. d3-Testosterone and methyltestosterone served as internal standards. Precision for all compounds at the concentrations of 0.5, 1, 5 and 10 ng/mL (n = 10) in fortified steroid-free serum samples ranged from 0.8% to 16.6%. Accuracy was calculated at the concentrations of 0.5, 1, 5 and 10 ng/mL and ranged from -9.2% to 10.6% (n = 10). Linear calibration equations were obtained for all five steroids (0.125-31.25 ng/mL) and for cortisol (0.125-200 ng/mL). Relative recoveries at concentrations 1.0 and 12.5 ng/mL ranged from 70.5% to 97.5%. Absolute recoveries at the same concentrations ranged from 73.2% to 96.6%. Reference intervals were estimated for infants aged from 9 to 40 days. The proposed steroid profile is suitable for routine analysis and provides meaningful data for samples within normal range as well as those with elevated levels.  相似文献   
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This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.  相似文献   
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