990 resultados para 230Th sup unc
Resumo:
Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> and Ni<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5–100 mg/L. The pH of the solutions containing either Cu<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> or Ni<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> was varied over a range of 2–8. The adsorption of Cu<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> and Ni<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">+2sup> on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6 mg/g for Cu<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> and 14.5 mg/g for Ni<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> at 298 K when the initial concentration for both Cu<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> and Ni<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2+sup> was 100 mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2 mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.
Resumo:
Extremely regular self-organized patterns of 90<sup>osup> ferroelastic domains have been reported in freestanding single crystal thin films of ferroelectric BaTiO3. Lukyanchuk et al. [Phys Rev B 79, 144111 (2009)] have recently shown that the domain size as a function of thickness for such free standing films can be well described assuming that the domains are due to stress caused by a surface tension layer that does not undergo the paraelectric–ferroelectric transition. From the starting point of Lukyanchuk’s model, it is shown here that the ‘‘universal’’relationship between domain size and domain wall thickness previously observed in ferroelectrics, ferromagnets and multiferroics is also valid for ferroelastic domains.Further analysis of experimental data also shows that the domain wall thickness can vary considerably (an order of magnitude) from sample to sample even for the same material (BaTiO3), in spite of which the domain size scaling model is still valid, provided that the correct,sample dependent, domain wall thickness is used.
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Highly charged ions have been used to study the sputtering of positive molecular fragments from mercaptoundecanoic acid and dodecanethiol self-assembled monolayers on gold surfaces. The samples were bombarded with Arq+ (42n<sup>+sup>, and Cn+1O2H2n + 1<sup>+sup> from mercaptoundecanoic and H+, CnH2n<sup>+sup>, and Cn+1H2n + 3<sup>+sup> from dodecanethiol. The proton yields were increased with larger charge state q of the highly charged ion (HCI) in both samples, scaling as qgamma, with gamma~5. The charge state dependence is discussed in terms of electron transfer to the HCI. The final yield of protons depends on molecular functional group characteristics, orientation on the surface, and reneutralization phenomena.
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Self-compacting concrete (SCC) flows into place and around obstructions under its own weight to fill the formwork completely and self-compact without any segregation and blocking. Elimination of the need for compaction leads to better quality concrete and substantial improvement of working conditions. This investigation aimed to show possible applicability of genetic programming (GP) to model and formulate the fresh and hardened properties of self-compacting concrete (SCC) containing pulverised fuel ash (PFA) based on experimental data. Twenty-six mixes were made with 0.38 to 0.72 water-to-binder ratio (W/B), 183–317 kg/m<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">3sup> of cement content, 29–261 kg/m<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">3sup> of PFA, and 0 to 1% of superplasticizer, by mass of powder. Parameters of SCC mixes modelled by genetic programming were the slump flow, JRing combined to the Orimet, JRing combined to cone, and the compressive strength at 7, 28 and 90 days. GP is constructed of training and testing data using the experimental results obtained in this study. The results of genetic programming models are compared with experimental results and are found to be quite accurate. GP has showed a strong potential as a feasible tool for modelling the fresh properties and the compressive strength of SCC containing PFA and produced analytical prediction of these properties as a function as the mix ingredients. Results showed that the GP model thus developed is not only capable of accurately predicting the slump flow, JRing combined to the Orimet, JRing combined to cone, and the compressive strength used in the training process, but it can also effectively predict the above properties for new mixes designed within the practical range with the variation of mix ingredients.
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The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the <sup>14sup>C<sup> sup>and calendar timescales as established in 2002. No change was made to the curves from 0-12 cal kBP. The curves were constructed using a Markov chain Monte Carlo (MCMC) implementation of the random walk model used for IntCal04 and Marine04. The new curves were ratified at the 20th International Radiocarbon Conference in June 2009 and are available in the Supplemental Material at www.radiocarbon.org.
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Background & aims: Little is known about energy requirements in brain injured (TBI) patients, despite evidence suggesting adequate nutritional support can improve clinical outcomes. The study aim was to compare predicted energy requirements with measured resting energy expenditure (REE) values, in patients recovering from TBI.
Methods: Indirect calorimetry (IC) was used to measure REE in 45 patients with TBI. Predicted energy requirements were determined using FAO/WHO/UNU and Harris–Benedict (HB) equations. Bland– Altman and regression analysis were used for analysis.
Results: One-hundred and sixty-seven successful measurements were recorded in patients with TBI. At an individual level, both equations predicted REE poorly. The mean of the differences of standardised areas of measured REE and FAO/WHO/UNU was near zero (9 kcal) but the variation in both directions was substantial (range 591 to þ573 kcal). Similarly, the differences of areas of measured REE and HB demonstrated a mean of 1.9 kcal and range 568 to þ571 kcal. Glasgow coma score, patient status, weight and body temperature were signi?cant predictors of measured REE (p < 0.001; R<sup>2=sup> 0.47).
Conclusions: Clinical equations are poor predictors of measured REE in patients with TBI. The variability in REE is substantial. Clinicians should be aware of the limitations of prediction equations when estimating energy requirements in TBI patients.
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Recent R-matrix calculations of electron impact excitation rates in Ar IV are used to calculate the emission-line ratio: ratio diagrams (R1, R2), (R1, R3), and (R1, R4), where K1 = I(4711 Å)/I(4740 Å), R2 = I(7238 Å)/I(4711 + 4740 Å), R3 = I(7263 Å)/I(4711 + 4740 Å), and R4 = I(7171 Å)/I(4711 + 4740 Å), for a range of electron temperatures (Te = 5000-20,000 K) and electron densities (Ne = 10-10<sup>6sup> cm<sup>-3sup>) appropriate to gaseous nebulae. These diagrams should, in principle, allow the simultaneous determination of Te and Ne from measurements of the [Ar IV] lines in a spectrum. Plasma parameters deduced for a sample of planetary nebulae from (R1, R3) and (R1, R4), using observational date obtained with the Hamilton echelle spectrograph on the 3 m Shane Telescope at the Lick Observatory, are found to show excellent internal consistency and to be in generally good agreement with the values of Te and Ne estimated from other line ratios in the echelle spectra. These results provide observational support for the accuracy of the theoretical ratios and, hence, the atomic data adopted in their derivation. In addition, they imply that the 7171 Å line is not as seriously affected by telluric absorption as previously thought. However, the observed values of R2 are mostly larger than the theoretical high-temperature and density limit, which is due to blending of the Ar IV 7237.54 Å line with the strong C II transition at 7236 Å.
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Aims: This review summarizes the currently available literature on the localization and proposed functions of a novel group of cells in the urinary bladder known as interstitial cells or interstitial cells of Cajal (ICC).
Methods: On-line searches of "Pubmed" for bladder, c-Kit, ICC, interstitial cell and myofibroblast were performed to identify relevant studies for the review.
Results: The literature contains substantial data that several sub-populations of ICC are present in the wall of the mammalian urinary bladder. These are located in the lamina propria and within the detrusor with distinctive cell shapes and morphological arrangements. Bladder ICC are identified with transmission electron microscopy or by immunohistochemical labeling using antibodies to the Kit receptor which is an established ICC marker. Lamina propria-ICC form a loose network connected via Cx43 gap junctions and are associated with mucosal nerves. Detrusor ICC track the smooth muscle bundles and make frequent contacts with intramural nerves. Both groups of ICC exhibit spontaneous electrical and Ca<sup>2+sup>-signalling and also respond to application of neurotransmitter substances including ATP and carbachol. There is emerging evidence that the expression of ICC is upregulated in pathophysiological conditions including the overactive bladder.
Conclusions: There is now a convincing body of evidence that specialized ICC are present in the urinary bladder making important associations with other cells that make up the bladder wall and possessing physiological properties consistent with a role of bladder activity modulation. Neurourol. Urodynam. 29: 82–87, 2010. © 2009 Wiley-Liss, Inc.
Resumo:
The induction and rejoining of radiation-induced double-strand breaks (DSBs) in cells of six bladder tumor cell lines (T24, UM-UC3, TCC-SUP, RT112, J82, HT1376) were measured using the neutral comet assay. Radiation dose-response curves (0-60 Gy) showed damage (measured as mean tail moment) for five of the cell lines in the same rank order as cell survival (measured over 0-10 Gy), with the least damage in the most radioresistant cell line. Damage induction correlated well with clonogenic survival at high doses (SF10) for all six cell lines. At the clinically relevant dose of 2 Gy, correlation was good for four cell lines but poor for two (TCC-SUP and T24), The rejoining process had a fast and slow component for all cell lines. The rate of these two components of DNA repair did not correlate with cell survival. However, the time taken to reduce the amount of DNA damage to preirradiated control levels correlated positively with cell survival at 10 Gy but not 2 Gy; radioresistant cells rejoined the induced DSBs to preirradiation control levels more quickly than the radiosensitive cells. Although the results show good correlation between SF10 and DSBs for all six cell lines, the lack of correlation with SF2 for TCC-SUP and T24 cells would suggest that a predictive test should be carried out at the clinically relevant dose. At present the neutral comet assay cannot achieve this. (C) 2000 by Radiation Research Society.
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C17 polyacetylenes are a group of bioactive compounds present in carrots which have recently gained scientific attention due to their cytotoxicity against cancer cells. In common with many bioactive compounds, their levels may be influenced by thermal processes, such as boiling or water immersion. This study investigated the effect of a number of water immersion time/temperature combinations on concentrations of these compounds and attempted to model the changes. Carrot samples were thermally treated by heating in water at temperatures from 50–100 °C and holding times of 2–60 min. Following heating, levels of falcarinol (FaOH), falcarindiol (FaDOH), falcarindiol-3-acetate (FaDOAc) and Hunter colour parameters (L<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">*sup>, a<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">*sup>, b<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">*sup>) were determined. FaOH, FaDOH, FaDOAc levels were significantly reduced at lower temperatures (50–60 °C). In contrast, samples heated at temperatures from 70–100 °C exhibited higher levels of polyacetylenes (p < 0.05) than did raw unprocessed samples. Regression modelling was used to model the effects of temperature and holding time on the levels of the variables measured. Temperature treatment and holding time were found to significantly affect the polyacetylene content of carrot disks. Predicted models were found to be significant (p < 0.05) with high coefficients of determination (R<sup style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2sup>).
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Tuning is a widespread technique to combine, date and interpret multiple fossil proxy archives through aligning supposedly synchronous events between the archives. The approach will be reviewed by discussing a number of literature examples, ranging from peat and tephra layers to orbital tuning and d<sup>18sup>O series from marine and ice deposits. Potential problems will be highlighted such as the dangers of circular reasoning and unrecognised chronological uncertainties, and some solutions suggested. Fossil proxy research could become enhanced if tuning were approached in a more quantitative, reliable and objective way, and especially if individual proxy archives were non-tuned and kept on independent time-scales.
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We treat the question of existence of common hypercyclic vectors for families of continuous linear operators. It is shown that for any continuous linear operator T on a complex Fréchet space X and a set ? ? R+ × C which is not of zero three-dimensional Lebesgue measure, the family {a T + b I : (a, b) ? ?} has no common hypercyclic vectors. This allows to answer negatively questions raised by Godefroy and Shapiro and by Aron. We also prove a sufficient condition for a family of scalar multiples of a given operator on a complex Fréchet space to have a common hypercyclic vector. It allows to show that if D = {z ? C : | z | < 1} and f ? H8 (D) is non-constant, then the family {z Mf{star operator} : b- 1 < | z | < a- 1} has a common hypercyclic vector, where Mf : H2 (D) ? H2 (D), Mf f = f f, a = inf {| f (z) | : z ? D} and b = sup {| f (z) | : | z | ? D}, providing an affirmative answer to a question by Bayart and Grivaux. Finally, extending a result of Costakis and Sambarino, we prove that the family {a Tb : a, b ? C {set minus} {0}} has a common hypercyclic vector, where Tb f (z) = f (z - b) acts on the Fréchet space H (C) of entire functions on one complex variable.
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Racemic (1R*,2R*)-1,2-dihydroxy-[1- <sup>13C 1]propylphosphonic acid and 1-hydroxy-[1- <sup>13sup>C 1]acetone were synthesized and fed to R. huakuii PMY1. Alanine and a mixture of valine and methionine were isolated as their N-acetyl derivatives from the cell hydrolysate by reversed-phase HPLC and analyzed by NMR spectroscopy. It was found that the carbon atoms of the respective carboxyl groups were highly <sup>13sup>C-labeled (up to 65 %). Hydroxyacetone is therefore considered an obligatory intermediate of the biodegradation of fosfomycin by R. huakuii PMY1.sup>
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Two stable nanofluids comprising of mixed valent copper(I,II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(4)mim][OAc], and copper(II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl) phosphonium acetate, [P-88812][OAc], were synthesised in a facile one-pot reaction from solutions of copper(II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using <sup>13sup>C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)2 in 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc], crystals were obtained that revealed the structure of [C2mim][Cu3(OAc)5(OH)2(H2O)]center dot H2O, indicating the formation of copper hydroxo-clusters in the course of the reaction. Synthesised nanostructures were studied using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Physical properties of the prepared IL-nanofluids were examined using IR and UV-VIS spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and densitometry.