排序方式: 共有16条查询结果,搜索用时 0 毫秒
1.
Fouad Boukli HacèneMiloud Tahar Abbés Nachida Kasbadji MerzoukLarbi Loukarfi Hacene Mahmoudi Matheus F.A. Goosen 《Renewable & Sustainable Energy Reviews》2012,16(1):29-36
A mathematical simulation model was developed that can determine the three-dimensional wind velocity field over a complex terrain. The Ténès area in the Valley of Cheliff in Algeria was used as a case study. This region is exposed to south-west circulation that makes it favorable to the use of wind energy. Knowledge of wind fields is crucial for predicting the dispersion of pollutants, for forecasting meteorological weather, for fire spread prediction and in the design and implementation of wind turbines. By means of a mass consistent model, an in-house program was developed to calculate the three-dimensional wind velocity field in the study region. The model was supported by a numerical box in which flow through is allowed for in the upper and lateral boundaries. The bottom boundary through which no flow through occurs was determined by the topographic relief at the surface. From measured wind velocities, observed values were calculated by interpolation-extrapolation. Using an optimization method, the adjusted velocities were obtained from constraints, observed velocities and the continuity equation. The model was verified with wind point data, the relative error did not exceed 6%. 相似文献
2.
A novel design of solar cooker is introduced. The cooker is of box-type equipped with an asymmetric compound parabolic concentrator (CPC) as booster-reflector. It consists of an insulated box equipped with a vertical double glazing cover on a side, and a vertical absorber plate laid out just behind the transparent cover. The booster-reflector is fixed on the glazed side of the box. The absorber plate and the glazing form a vertical channel, open at the top and bottom, and enclosed at the sides. The two openings allow the inside air circulation. A mathematical model of the heat transfer processes involved with this solar cooker, containing a cooking pot loaded with water and deposited on the box floor; was developed and the effects of various parameters, such as solar radiation, load of water and clouds on the dynamic behavior of the cooker are studied. 相似文献
3.
For the study of the phenomenon of the Algerian High Plains turning into a desert, two approaches were used. The first consists of the processing of data measured on the level of weather stations located on the soil and the second by the use of a model allowing the interpolation and the extrapolation of data measured at 700 Hpa towards the soil, taking into account the terrain conditions. The two methods showed that the dominant winds are in the northern and western sectors, suggesting that the wind is not the principal factor in the progress of the sand towards north. 相似文献
4.
5.
Merzouk SA Saker M Reguig KB Soulimane N Merzouk H Guermouche B Berrouiguet AY Hichami A Narce M Khan NA 《Lipids》2008,43(6):485-497
In this work, we assessed the in-vitro effects of eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3) (final concentration, 15 microM) on T cell blastogenesis, interleukin-2 and -4 (IL-2, IL-4) secretion, fatty acid composition and intracellular oxidative status in type I diabetic patients with or without complications. Con A stimulated lymphocyte proliferation, glucose uptake, intracellular reduced glutathione levels and catalase activity were lower in diabetics as compared to controls, regardless to the presence of complications. EPA and DHA diminished T-lymphocyte proliferation and IL-2 production but enhanced IL-4 secretion in both diabetic and control groups. No changes in the levels of reduced glutathione and in the activities of catalase and SOD were observed in control T cells cultured in the presence of EPA and DHA. However, in diabetic patients, addition of n-3 PUFA to culture induced an increase in T cell levels of reduced glutathione and hydroperoxide, and in activities of catalase and SOD. Low levels of arachidonic acid (C20:4n-6) were found in plasma membrane phospholipids of lymphocytes from diabetic patients compared to controls. Incubation of lymphocytes with EPA and DHA was associated with an incorporation of these fatty acids in membrane phospholipids. In conclusion, the beneficial effects of n-3 PUFA on T cell functions in type I diabetes could be attributed to their suppressive action and modulation of cytokine secretion, and to the improvement of intracellular oxidative status. 相似文献
6.
The time course of changes in lipoprotein metabolism of obese offspring of mildly diabetic rats was studied with respect to
serum lipoprotein composition as well as LCAT and tissue lipoprotein lipase (LPL) activities. Mild hyperglycemia in pregnant
rats was induced by intraperitoneal injection of streptozotocin on day 5 of gestation. Control pregnant rats were injected
with citrate buffer. At birth, obese pups had higher serum glucose, insulin, and lipoprotein (VLDL, LDL-HDL1, HDL2–3) levels than control pups. After 1 mon of life, all of these parameters in obese rats became similar to those of controls.
However, LCAT, adipose tissue LPL, and hepatic triacylglycerol lipase activities were high. At 2 mon of age, VLDL-TAG levels
were higher in obese females than in controls. By the age of 3 mon, obese offspring had developed insulin resistance with
hyperglycemia, hyperinsulinemia, and higher serum lipoprotein concentrations. Indeed, qualitative abnormalities of lipoproteins
were seen and were typical of obese and diabetic human beings. Fetal hyperinsulinemia should be considered as a risk factor
for later metabolic diseases, including dyslipoproteinemia. 相似文献
7.
8.
Using electrocoagulation-electroflotation technology to treat synthetic solution and textile wastewater, two case studies 总被引:1,自引:0,他引:1
The purpose of this study was to investigate the effects of the operating parameters, such as pH, initial concentration (Ci), duration of treatment (t), current density (j), interelectrode distance (d) and conductivity (κ) on the treatment of a synthetic wastewater in the batch electrocoagulation (EC)-electroflotation (EF) process. The optimal operating conditions were determined and applied to a textile wastewater. Initially a batch-type EC-EF reactor was operated at various current densities ranging from 11.55 to 91.5 mA/cm2 and various electrode gaps (1, 2 and 3 cm). For solutions with 300 mg/L of silica gel, good turbidity removal (89.6%) was obtained without any coagulant when the current density was 11.55 mA/cm2, and with initial pH at 7.6, conductivity at 2.1 mS/cm: the treatment time was hold for 10 min and the electrode gap was 1 cm. Application of the optimal operating parameters on a textile wastewater showed a high removal efficiency for the following variables: suspended solid (SS) 85.5%, turbidity 76.2%, biological oxygen demand (BOD5) 88.9%, chemical oxygen demand (COD) 79.7%, and color over 93%. 相似文献
9.
Nadia Chekir Djilali Tassalit Ouassila Benhabiles Nachida Kasbadji Merzouk Meriem Ghenna Anes Abdessemed Rachid Issaadi 《International Journal of Hydrogen Energy》2017,42(13):8948-8954
The fixed bed reactor was combined with a solar photoreactor and UV lamp reactor. This hybrid photoreactor used a heterogeneous photocatalysis process (TiO2/UV) as a tertiary treatment for the degradation of tartrazine dye in water. The solar reactor removed almost all organic compounds from the wastewater. Photocatalysis was optimized using a parametric study to improve the influence of different parameters on the degradation efficiency. Color removals when using solar, UV lamp and hybrid reactors present 99%, 30%, and 99%, respectively. Tartrazine removal kinetics followed a pseudo-first order model. The hybrid solar and UV lamp system combination was a feasibility choice for removing both dyes from wastewater. 相似文献
10.