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81.
82.
Mariela C. Olguín Viviana O. Salvadori Rodolfo H. Mascheroni Domingo A. Tarzia 《International Journal of Heat and Mass Transfer》2008,51(17-18):4379-4391
The coupled problem of heat and mass transfer during the solidification of high-water content materials like soils, foods, tissues and phase-change materials is developed. Assuming quasi-steady heat conduction in the frozen region, the system leads to a set of coupled ordinary differential equations. The model takes into account the influence of material characteristics and process variables on the advance of the freezing and sublimation fronts, temperature and water vapour profiles and weight loss. It was validated against the analytical solution of the freezing (without surface ice sublimation) of a semi-infinite medium and was extensively used to perform a parametric study. 相似文献
83.
Graphene: Large‐Area Si‐Doped Graphene: Controllable Synthesis and Enhanced Molecular Sensing (Adv. Mater. 45/2014) 下载免费PDF全文
84.
85.
This paper illustrates a simple method for evaluating the energy output of windgenerators of known main characteristics in a site of known wind typology. The method is based on the matching of a model of the WECS with the Weibull model of wind regime. To enter the method the following quantities must be known: Weibull shape parameter and mean wind speed, turbine diameter, hub height, cut-in and nominal wind speeds and nominal power. With these quantities one can enter a diagram that gives the value of the plant utilisation factor for any specific siting. An example shows how to make a choice among several models of small size. 相似文献
86.
Ricardo Dunia Antonio Campo Rodolfo Guzman 《Journal of Petroleum Science and Engineering》2011,78(2):486-496
Pressure and temperature developing profiles for crude oil transportation pipelines are simulated under a diversity of external boundary conditions. MOLCV is used in this research to convert a system of partial differential equations into a system of ordinary first order differential equations in cylindrical coordinates. Momentum and energy balance equations are coupled in crude oil flows because of thermal–physical property variations. Simulation solutions show the effect of boundary conditions in the pressure drop profile, which provide potential model predictive applications to account for weather forecast in crude oil transportation operations. 相似文献
87.
Dario Beruto Rodolfo Botter Alan W. Searcy 《Journal of the American Ceramic Society》1989,72(2):232-235
The H2 O-catalyzed sintering of MgO in temperature gradients between 1303 and 1233 K is compared to sintering of isothermal samples. Both the changes in sample dimensions in planes normal to the temperature gradients and the increases in density for a fixed sintering time are greater than predicted on the assumption that densification in a temperature gradient is a function only of each local temperature in the gradient. Under the conditions used, neither vapor transport nor transport through a liquid phase is important. The results, therefore, support a recent prediction that temperature gradients supplement surface energy changes in driving sintering and related processes not only by vapor transport, as expected from earlier studies, but also by a surface, grainboundary, or bulk diffusion path. 相似文献
88.
U. Len-Silva M.E. Nicho Hailin Hu Rodolfo Cruz-Silva 《Solar Energy Materials & Solar Cells》2007,91(15-16):1444-1448
In this work, we report the morphological and electrochromic properties of electrochemically synthesized polyaniline (PANI) thin films on bare and modified indium–tin oxide (ITO) glass substrates. In the last case, the surface of ITO glass was covered by a self-assembled monolayer of N-phenyl-γ-aminopropyl-trimethoxysilane (PAPTS). Atomic force microscopy images and perfilometry show that smoother and thinner PANI films were grown on PAPTS-modified ITO substrates. PANI-based electrochromic devices (ECDs) were assembled by using a viscous polymeric electrolyte (PE) of LiClO4 and polymethyl methacrylate (PMMA) co-dissolved in a mixture of propylene and ethylene carbonate. The architectural design of the devices was glass/ITO/PANI/PE/ITO/glass. A dual ECD was also prepared by collocating a poly(3-methylthiophene) (P3MT) thin film as a complementary electrochromic element. The effect of the PAPTS-modified ITO substrate is reflected in a higher optical transmittance at bleach state and a little less color change at 550 nm of PANI-based ECDs. 相似文献
89.
In this work we make a first, partial, assessment of the low- to medium-temperature geothermal reserves of Mexico. The assessment covers about 30% of the identified geothermal surface manifestations. For reserve assessment we use the volume method, supplemented by Montecarlo simulations and statistics, in order to quantify the inherent uncertainties. We estimate these reserves as lying between 7.7 × 1016 and 8.6 × 1016 kJ, with 90% confidence. The distribution of most likely reservoir temperatures is in the 60–180 °C range, with a mean of 111 °C. These massive amounts of recoverable energy and the associated temperatures are potentially important for the economic development of the associated geothermal localities. 相似文献
90.
JL Goldberg CL Zanella YM Janssen CR Timblin LA Jimenez P Vacek DJ Taatjes BT Mossman 《Canadian Metallurgical Quarterly》1997,17(3):265-271
We developed in situ dual-fluorescence detection techniques for measuring apoptosis and proliferation simultaneously in single dishes of cells. The deoxyribonucleic acid (DNA)-specific labeling method, terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), first was used in conjunction with a 4',6-diamidino-2-phenylindole (DAPI) counterstain to detect and measure morphologic characteristics of apoptotic rat pleural mesothelial (RPM) cells isolated from Fischer 344 rats and exposed to 300 microM hydrogen peroxide (H2O2). For this purpose, 100 TUNEL-positive nuclei were measured while being viewed with DAPI counterstaining for area, perimeter, longest diameter, and average diameter, using imaging software and an image-collection apparatus. We then exposed cells to a range of concentrations of crocidolite asbestos and putative apoptotic and mitogenic agents. Exposure to crocidolite asbestos (5 microg/cm2) caused a striking dose-dependent apoptotic response at 24 h, 48 h, and 72 h. The nonfibrous crocidolite analogue riebeckite failed to induce apoptosis. At 24 h, tumor necrosis factor-alpha (TNF-alpha) (10 ng/ml) caused an increase in apoptotic nuclei. A second method, utilizing an antibody to 5'-bromodeoxyridine (BrdU) and oxazole yellow homodimer (YOYO), showed a dose-dependent increase in proliferation occurring in cells exposed to asbestos (5 microg/cm2) at 48 h and 72 h. In addition, increased numbers of rat pleural mesothelial (RPM) cells exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA), TNF-alpha, and epidermal growth factor (EGF) exhibited incorporation of BrdU at these time points, although total numbers of cells per unit area were unchanged. Results indicate a dynamic balance between apoptosis and increased DNA synthesis after exposure of mesothelial cells to asbestos. 相似文献