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51.
Photovoltaic (PV) pumping offers the possibility of supplying water to remote and desert regions for their daily needs. The sizing of the PV pumping systems is a very significant step in order to optimize the power peak of the PV array and to ensure the best choice of the motor, the pump and the inverter. Two mathematical models were proposed in this article to contribute in the studies of PV pumping sizing. These models link directly the operating electrical power to the water flow rate of the pump versus total head. These models are based essentially on the experimentation of pumps on CDER PV pumping test facility. Two pumping systems are tested: the first uses a centrifugal pump and the second uses a positive displacement pump. The results obtained by the models are very satisfactory. Also, the models enabled us to simulate the electrical and hydraulic performances of two tested pumps. The performances are calculated using the measured meteorological data of different sites located in Sahara and coastline regions of Algeria. 相似文献
52.
M Benyoucef V Zuerbig JP Reithmaier T Kroh AW Schell T Aichele O Benson 《Nanoscale research letters》2012,7(1):493
ABSTRACT: The authors report single-photon emission from InGaAs quantum dots grown by droplet epitaxy on (100) GaAs substrates using a solid-source molecular beam epitaxy system at elevated substrate temperatures above 400 [DEGREE SIGN]C without post-growth annealing. High-resolution micro-photoluminescence spectroscopy exhibits sharp excitonic emissions with lifetimes ranging from 0.7 to 1.1 ns. The coherence properties of the emitted photons are investigated by measuring the first-order field correlation function. 相似文献
53.
Kaddour Ziani Marcos Pérez-López Abdeldjallil Mansouri Meghit Boumedienne Khaled Antonio Silva Rodriguez Miloud Slimani 《Food Analytical Methods》2018,11(9):2528-2537
The aim of this study was to determine and to compare the presence of oxytetracycline (OTC) residues in raw and cooked (boiled) meat before and after withdrawal period with the Maximum Residue Limits (MRL) using biological and physicochemical techniques. In animal building of 2000 broiler chickens (Gallus domesticus, breed ISA F15) and under the same conditions, 12 healthy adult chickens were selected and divided in two groups (n?=?6 in each group). The sample was treated by Oxytetracycline® 20% (0.4 g/kg) during 3 days. Juices and muscles tissues were sampled twice for this assay: first, the broiler chickens were slaughtered (n?=?6) 24 h after the third day of treatment. However, the second sampling (n =?6) was performed 24 h after the end of the withdrawal period. For each portions of sample, the juice meat and muscle tissues samples were collected after cooking at 80 °C during 45 min and after freezing/defrosting for the raw meat. Biological methods consisted of using four plates test (FPT) to pre-screening and Premi®Test to screening. Finally, to confirm and to quantify the accurate level of OTC in positive samples, ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) measurements were conducted. The FPT test showed that all samples were positive. While the Premi®Test analysis showed negative results for raw meat tested and positive results for juice of meat cooked in both samples. The obtained results using UHPLC-MS/MS methods confirmed the previously results. Thus, the presence of such toxic substances in our diet constitutes a major health risk for consumers, requiring the establishment of an adequate monitoring system. There is a paucity of official withdrawal periods for veterinary medicinal products in cooking meat; a relationship between the concentrations of residues of antibiotics after waiting period and cooking is not established since meat is always cooked before consumption. 相似文献
54.
Ouis Dalila El Kebir Abdelkader Moulefera Imane Sabantina Lilia Abdelghani Benyoucef 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(3):1092-1102
Journal of Inorganic and Organometallic Polymers and Materials - This study investigated the preparation of new adsorbent based PANI and Kieselguhr (KG). The produced materials were characterized... 相似文献
55.
Universal Access in the Information Society - Advances in mobile technologies and wireless Internet services have accelerated the growth of the mobile app market. To nurture such growth, the... 相似文献