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排序方式: 共有417条查询结果,搜索用时 15 毫秒
381.
B Spunt I Dupont H Lesieur HJ Liberty D Hunt 《Canadian Metallurgical Quarterly》1998,33(13):2535-2560
This paper reviews research conducted on the link between pathological gambling and substance misuse. We first examine the phenomenon of "pathological gambling," including similarities between pathological gambling and substance misuse, instruments used to measure pathological gambling, and the prevalence of pathological gambling in the United States and internationally. We then examine research on substance misuse among pathological gamblers, pathological gambling among substance misusers, and the treatment of the pathological gambler-substance misuser. We conclude with a discussion of future research needs. 相似文献
382.
M. Van Audenhaege J. Belmejdoub D. Dupont A. Chalvin S. Pezennec Y. Le Gouar F. Garnier-Lambrouin M. Rabiller-Baudry G. Gesan-Guiziou 《Journal of dairy science》2010,93(9):3910-3924
Understanding filtration mechanisms at a molecular level is important for predicting structural and functional properties of globular milk proteins after membrane operations. This stage is thus highly decisive for the further development of membrane separations as an efficient alternative to chromatographic processes for the fractionation of milk proteins. In this study, we proposed an original and complete analytical package for the examination of the putative effect of filtration at both macroscopic and molecular levels. We then investigated the pertinence of this analytical package during ultrafiltration (UF) of globular milk proteins in both dead-end and crossflow modes. Reverse-phase HPLC combined with statistical computing was shown to be relevant for the assessment of even slight physically induced modifications. Adaptations of circular dichroism and solubility measurements, regarding their respective dependence on temperature and pH, were also useful for an accurate evaluation of functional modifications. At last, immunochemistry was proven to be a pertinent tool for the specific detection of modifications affecting a targeted protein, even in mixed solutions. Moreover, results obtained by such methods were shown to be coherent with data obtained from classical techniques such as fluorescence. For β-lactoglobulin, some physically induced modifications were noticed in the permeate because of shear stress inside membrane pores. In the case of α-lactalbumin dead-end UF, permeation was shown to affect protein characteristics because of an increase in the relative calcium content responsible for a conformational transition from the apo-form to the holo-form of the protein. Finally, during crossflow UF with limited transmission of BSA, observations were coherent with a partial aggregation because of the circulation of proteins in the filtration pilot. Such a hypothesis corroborates results previously mentioned in the literature. 相似文献
383.
Emmanuel Lafond Richard Coulette Christine Grand Marie-Hélène Nadal Bruno Dupont François Lepoutre Daniel Balageas Odile Pétillon 《NDT & E International》1998,31(2):85-92
The new laser-based ultrasound model presented in this paper takes into account the layered structures generally encountered in aeronautic materials (painted metals, composites, lapped joints…) which are subjected to impacts, fatigue and corrosion. The structure is supposed to be a plate made of two layers of different materials. The sample presents a cylindrical orthotropy. Validations of the model are performed by comparing the results it provides with experimental measurements using a Nd:YAG pump laser and an interferometric detection. The symmetry of the model allows fast calculation and prediction of the displacements over a long time period. These advantages are used to study the improvement of the laser-ultrasonic generation, by varying the thickness of the first layer in the case of a NDT strippable paint layer covering a metal layer. 相似文献
384.
Ali Moussa Daniel Dupont Daniel Steen Xianyi Zeng 《Color research and application》2009,34(4):274-284
This article studies the influence of the incidence angle of illumination and the textile structure on its coloristic rendering. Three geometric measurements of color (25°a:0°, 45°a:0°, and 75°a:0°) and three different structures (roving, yarn, and woven fabric) were used. The transformations of the reflectance factor spectrum because of the changes of these two parameters were modeled and the evolutions of the colorimetric coordinates associated with these various transformations were thus calculated and analyzed. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 274–284, 2009 相似文献
385.
B. Mei B. De Sutter T. Vander Aa M. Wouters A. Kanstein S. Dupont 《Journal of Signal Processing Systems》2008,51(3):225-243
Architecture for Dynamically Reconfigurable Embedded Systems (ADRES) is a templatized coarse-grained reconfigurable processor
architecture. It targets at embedded applications which demand high-performance, low-power and high-level language programmability.
Compared with typical very long instruction word-based digital signal processor, ADRES can exploit higher parallelism by using
more scalable hardware with support of novel compilation techniques. We developed a complete tool-chain, including compiler,
simulator and HDL generator. This paper describes the design case of a media processor targeting at H.264 decoder and other
video tasks based on the ADRES template. The whole processor design, hardware implementaiton and application mapping are done
in a relative short period. Yet we obtain C-programmed real-time H.264/AVC CIF decoding at 50 MHz. The die size, clock speed
and the power consumption are also very competitive compared with other processors.
相似文献
S. DupontEmail: |
386.
Muriell Gamba Alexandre A.M. Lapis Jairton Dupont 《Advanced Synthesis \u0026amp; Catalysis》2008,350(1):160-164
Pseudomonas cepacia lipase supported in the 1‐n‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid is an alternative “green” method for the production of biodiesel from the alcoholysis of soybean oil. The transesterification reaction catalyzed by this ionic liquid‐supported enzyme can be performed at room temperature, in the presence of water and without the use of organic solvents. It is also compatible with various alcohols (including isoamyl alcohol). The biodiesel is separated by simple decantation and the recovered ionic liquid/enzyme catalytic system can be re‐used at least four times without loss of catalytic activity and selectivity. 相似文献
387.
G. Nagaraju J.P. Shubha K. Manjunath J. Dupont 《International Journal of Hydrogen Energy》2018,43(8):4028-4035
Photocatalytic hydrogen generation is one of the most promising solutions to convert light energy into green chemical energy. In the present work, methoxy ethyl methyl imidazolium methyl sulphonate ionic liquid is used for the synthesis of i-TiO2 nanoparticles via ionothermal method at 120 °C. The obtained products were characterized by various spectroscopic techniques like XRD, FTIR, Raman, UV–visible, DRS, TEM and TG-DSC analysis. XRD pattern confirmed the anatase phase with minor rutile phase having average crystallite size of 5 nm. From the FTIR spectrum, the band appeared at ~547 cm?1 confirmed the Ti–O–Ti stretching and also few bands of ionic liquid. UV–vis spectrum clearly reveals the blue shift due to size effect of TiO2. The spherical surface structure and particle size (15–30 nm) have been studied in detail using TEM images. Finally, the practical applicability of the as synthesized i-TiO2 nanoparticles is shown by using it as a photocatalyst towards the generation of H2 through water splitting reaction and it is found to be 462 μmol h?1g?1. 相似文献
388.
Haisheng Chen Tianfu Zhang Bilin Dou Valerie Dupont Paul Williams Mojtaba Ghadiri Yulong Ding 《International Journal of Hydrogen Energy》2009,34(17):7208
A non-stoichiometric thermodynamic analysis is performed on the adsorption-enhanced steam reforming of glycerol for hydrogen production based on the principle of minimising the Gibbs free energy. The effects of temperature (600–1000 K), pressure (1–4 bar), water to glycerol feed ratio (3:1–12:1), percentage of CO2 adsorption (0–99%) and molar ratio of carrier gas to feed reactants (1:1–5:1) on the reforming reactions and carbon formation are examined. The results show that the use of a CO2 adsorbent enhances glycerol conversion to hydrogen and the maximum number of moles of hydrogen produced per mole of glycerol can be increased from 6 to 7 due to the CO2 adsorption. The analyses suggest that the most favourable temperature for steam–glycerol reforming is between 800 and 850 K in the presence of a CO2 adsorbent, which is about 100 K lower than that for reforming without CO2 adsorption. Although high pressures are favourable for CO2 adsorption, a lower operating pressure gives a higher overall hydrogen conversion. The most favourable water to glycerol feed ratio is found to be 9.0 above which the benefit becomes marginal. Carbon formation could occur at low water to glycerol feed ratios, and the use of a CO2 adsorbent can suppress the formation reaction and substantially reduce the lower limit of the water to glycerol feed ratio for carbon formation. 相似文献
389.
M.P. Stracke M.V. Migliorini E. Lissner H.S. Schrekker J. Dupont R.S. Gonçalves 《Applied Energy》2009
A set of four imidazolium ionic liquids (solid at room temperature) and one imidazolium ionic solid was screened for its potential as electrolytes in manganese dioxide free Leclanché batteries, equipped with a zinc anode and graphite cathode. Electrical impedance spectroscopy allowed to determine the room-temperature ionic solids (RTISs) ionic conductivities, which was the highest for carboxylic acid functionalized RTIS 3 [C2O2MIm][Cl]. The toxic manganese dioxide was substituted by benzoquinone. A systematic ionic conductivity optimization of RTIS 3–benzoquinone–ZnSO4–H2O mixtures at room temperature resulted in the identification of the following conditions for the Leclanché battery studies: 50 mg of a 50:50 RTIS:benzoquinone mixture and 96 mg of water. The chronopotentiometric experiments with a constant current of 5 μA showed a remarkable performance for the RTIS 3 based battery. The potential (1.47 V) and stability is comparable to that of the commercial Rayovac® battery filling (model AA). Furthermore, linear potentiodynamic voltammetry (0.01 V/s) and chronoamperometric analysis at short-circuit conditions (0.0 V) validated the RTIS 3–benzoquinone–water battery as a promising alternative for manganese dioxide free Leclanché batteries. 相似文献
390.
GledisonS. Fonseca EdsonT. Silveira MarcosA. Gelesky Jairton Dupont 《Advanced Synthesis \u0026amp; Catalysis》2005,347(6):847-853
The influence of substituents on rate constants of the hydrogenation of monoalkylbenzenes by transition metal nanoparticles or by classical heterogeneous catalysts can be rationalized in terms of the Taft rule. A series of the initial reaction rate constants obtained from various competitive toluene/benzene and toluene/monoalkylbenzene hydrogenation experiments catalyzed by transition‐metal nanoparticles prepared in the presence of imidazolium ionic liquids or surfactants [Ir(0), Rh(0) and Ru(0)] or by classical heterogeneous catalysts (PtO2, Rh/C, Rh/Al2O3, Ru/C, Ru/Al2O3 and Pd/C) have been correlated with the Taft equation . Satisfactory correlation coefficients (r) (between 0.96 and 0.99) and positive slopes (ρ) between 0.38 and 0.83 have been obtained. The results clearly show that the reaction constants for the alkyl‐substituents can be expressed by steric factors and are independent of any other non‐steric factors. It is suggested that bulky alkylbenzene substituents, for both transition metal nanoparticles and classical heterogeneous hydrogenation reactions, lower the overall hydrogenation rate, implying a more disturbed transition state compared to the initial state of the hydrogenation (in terms of the Horiuti–Polanyi mechanism). This competitive method is suitable for the estimation of the constant selectivity for couples of alkylbenzenes in which the difference in hydrogenation rates are very high and experimentally difficult to measure and also useful for the design of more selective “nano” and classical catalysts for hydrogenation reactions. 相似文献