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Quantification and Qualification Analysis of the Heat Waves Using Heat Wave Norm in the Region of Bechar (Algeria) during the Period 1951-2010

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Atmospheric and Climate Sciences 2020年第3期10卷 273-279页

作者： miloud Oubadi Ahmed Hamou Fantina Tidim Laboratory of Environmental and Materials Sciences Faculty of Exact & Applied Sciences Oran University 1-Ahmed Ben Bella Oran Algeria Scientific and Technical Research Center on Arid Regions Biskra Algeria Department of Geography Faculty of Letters University of Porto Porto Portugal Charles Darwin University Darwin Australia

This study presents a new non-parametric measure of heat waves called heat wave norm (HWN), which allows quantifying and qualifying the magnitude of the summer heat wave events in the Bechar region located northwest of the Algerian Sahara over the period 1951-2010. The index, based on the analysis of daily maximum and minimum temperatures by adding them, integrated two dimensions at the same time: the duration and the excess heat. The results show an increase in the intensity and frequency of extreme events. More specifically, from the 1980s, it is possible to observe the propagation of extreme and very extreme and super extreme heat waves in recent decades with maximum presence during the period 1990-2010. In general, it can be said that the trend of excessive warming is clearly displayed in the Algerian Sahara, generally classified as a hot region.

关键词： Algerian Sahara Bechar Excess Heat Duration Heat Wave HWN

Elaboration and Characterization of AuCl Semiconductor Nanocrystals Embedded in KCL Single Crystals

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Journal of Modern Physics 2012年第7期3卷 534-537页

作者： Fouzia Zehani miloud Sebais Hanane Zaioune Laboratoire de Cristallographie (LC). Université de Mentouri-Constantine. Wilaya de Constantine. ALGERIA Laboratoire d'Etude des Matériaux (LEM). département de physique. facultés des sciences exactes et des sciences de la nature et de la vie. Université de Jijel. BP 98 Ouled Aissa. Wilaya de Jijel. ALGERIA

In this work, we investigated the structural and the optical properties of AuCl semiconductor nanocrystals embedded in KCl single crystals. The AuCl nanocrystals were obtained by doping the KCl crystalline matrix with gold using the Czochralski method. The X-ray diffraction showed the formation of the AuCl nanocrystals in KCl with a tetragonal structure. The average radius of the AuCl nanocrystals is estimated using the Scherrer formula. The photoluminescence spectra presented a band emission situated at 580 nm leading to the formation of the AuCl nanocrystals within KCl.

关键词： AuCl Semiconductor Nanocrystals X-Ray Diffraction Photoluminescence

Performance Optimization of Diesel Generators Using Permanent Magnet Synchronous Generator with Rotating Stator

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Energy and Power Engineering 2019年第7期11卷 259-282页

作者： Mohammadjavad Mobarra Mohamad Issa miloud Rezkallah Adrian Ilinca Wind Energy Research Laboratory (WERL) Université du Québec à Rimouski Rimouski Canada Electrical Engineering Department Ecole de Technologie Supérieure (ETS) Montréal Canada

One of the solutions to reduce fuel consumption of diesel generators (DG) is to adapt the rotational speed to mechanical torque of the crankshaft. When load power decreases, a reduction in both mechanical torque and rotational speed of the diesel engine will maintain the combustion efficiency near the levels of the nominal regime. Accordingly, the generator itself should operate at a variable speed which normally requires power electronics converters. In this paper, we are exploring a new generator concept that uses a stator rotating in opposite direction to the rotor such as the relative velocity between the two components remains constant when diesel engine slows down. The stator itself is driven by a compensator synchronous motor (CM) such as the relative velocity of the rotor is constant, eliminating as such sophisticated power electronics. The model developed for the synchronous machine with a rotating stator is based on Park’s transformation. This new concept was modelled using MATLAB software. Experimental analysis has been conducted using a 500-kW diesel GENSET equipped with a permanent magnet synchronous generator (PMSG). The numerical and experimental results are in good agreement and demonstrate that fuel consumption is reduced with a rotating-mode stator for PMSG during low electrical loads.

关键词： Diesel Generator Park Transformation Rotating Stator Fuel Optimization Rotating Reference Frame

Safflower Evaluation under Contrasted Environment Conditions and Selection of Promising Genotypes

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Journal of Agricultural Science and Technology(B) 2014年第4期4卷 299-311页

作者： Lamyae Zraibi miloud Kajeiou Hana Serghini Caid Abdelghani Nabloussi Laboratory of Plants and Microorganisms Biology Biology Department Faculty of Sciences University of Mohamed PremierOujda 60000 Morocco Research Unit of Plant Breeding and Plant Genetic Resources Conservation National Institute for Agricultural Research CRRAof Meknes Meknes 50000 Morocco

Development of stable crops cultivars adapted to environmental constraints is very important for food security. Safflower, an oilseed crop which tolerates environmental abiotic stresses, is suitable for marginal lands relatively dry and deprived from fertilizer inputs or irrigation. A set of Moroccan and introduced cultivars as well as international accessions were conducted at Oujda （Eastern of Morocco） during 2009-2010 for late and conventional sowing under two water regimes, in a field experiment using a completely randomized design, with three replications. The objective was to evaluate the effect of genotype and contrasting environment on safflower behavior and to select genotypes with large adaptation to the contrasted environmental conditions. Morphological, physiological and agronomic traits, as well as the stress susceptibility index （SSI）, were recorded in this study. Results showed significant effect of genotype, year （sowing time）, water regime and their interaction on most of the studied parameters. Late sowing and drought affected negatively all the parameters except seed oil which lightly increased under drought stress. Number of heads per plant （NHP） had the strongest association with seed yield under both drought and non-drought conditions, and hence could be taken as selection criterion for safflower seed yield improvement. Five accessions showed the highest overall mean seed yield （~ 1,000 kg/ha） and four accessions exhibited the highest overall mean seed oil content （〉 310 g/kg）. For late sowing, the accessions P1262421 and PI537604 produced the highest seed yield （〉 800 kg/ha） and the highest seed oil content （〉 290 g/kg）. For conventional sowing, the accessions PI250076 and PI250523 were the most performant, with a seed yield 〉 1,300 kg/ha and a seed oil content 〉 330 g/kg. Based on their mean productivity across environments, their SSI and their MDA, P1271073 and P1250076 could be selected and used as promising germplasm in safflower breeding

关键词： Safflower contrasted environments NHP seed yield oil content selection promising genotypes.

Identification and Physiological Properties of Bifidobacterium Strains Isolated from Different Origin

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Journal of Food Science and Engineering 2013年第4期3卷 196-206页

作者： Fatima Mahmoudi Hadadji miloud Guessas Bettache Kihal Mebrouk Laboratory of Applied Microbiology Department of Biology Faculty of Science University of Oran El-menaouer BP 1524Es-Senia Oran 31100 Algeria

Bifidobacteria play an important role in maintaining human health, and suppress harmful bacteria by controlling the pH of the large intestine. About 14 strains of the Bifidobacteria have been isolated from the faeces of infants nursed exclusively from the maternal milk （their ages less than 5 months） from commercial French yoghurt （active bifidus] and from milk （celia bifidus） on MRS medium （containing 0.05% cysteine-HC1, with nalidixic acid 2 mg rel）. A total of six strain are strict anaerobic and gram-positive Bifidobacteria, identified as, B. longum （60% of the samples） was the most frequently found species, followed by B. bifidum （21.0%）, B. breve （19%）. These strains were evaluated for potential use as probiotics based on their adhesion to intestinal epithelial cells, resistance towards acidic （resistance to low pH） and bile conditions, pH values ranging from 6.5 to 7, however, these strains are sensitive to the pH 8, Bifidobacterium are mesophiles with optimal growth at 36℃ to 41℃. All isolates studied have a fast growth in glucose.

关键词： Probiotic Bifidobacterium acidity survival growth isolate

Numerical Simulation of Heat Exchanger＇s Length＇s Effect in a Thermoacoustic Engine

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Journal of Physical Science and Application 2015年第1期5卷 61-65页

作者： Mohamed Zouhir Dar Ramdane miloud Abidat Mohamed Hamel Institute of Maintenance and Industrial Security University of Oran BP1524 El M'Naouer Oran 31000 Algerie Applied Mechanics Laboratory USTO-MB BP 1505 Oran El M'Naouer Oran 31000 Algerie

A numerical study of a standing-wave thermoacoustic engine is presented. The aim of this work is to study the effect of increasing the heat exchangers length on the acoustic power. The analysis of the flow and the prediction of the heat transfer are performed by solving the non linear unsteady Navier-Stocks equations using the finite volume method implemented in -ANSYS CFX- CFD code. The results show an increase in the limit cycle acoustic pressure and power as well as the specific work per cycle with the increase of heat exchangers length.

关键词： Thermoacoustic engine CFD heat exchanger acoustic pressure.

Characterization and Technological Properties of Bifidobacterium Strains Isolated from Breast-fed Infants

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Journal of Food Science and Engineering 2012年第10期2卷 576-582页

作者： Bahloul Halima Auras Hadadji miloud Guessas bettache Saidi Noureddine Kihal mebrouk Laboratory of Applied Microbiology Department of Biology Faculty of Science University of Oran El-menaouer BP 1524Es-SeniaOran 31100 Algeria

Bifidobacteria represent the largest group of human intestinal bacteria. They have an important place in human health and represent the dominant group microflora of the newbom breast-fed. Following the behavior of strains of Bifidobacteria isolated from the breast-fed infants and from saline rehydration solution was considered in order to develop therapeutic fermented milk. Samples from newborn infants aged 10 months, or from a saline rehydration solution （Celia/Develop ORS） containing Bifidobacteria sold was used and isolated strains belonged to breve and longum species. Those strains showed preferences to neutral pH. They are mesophilic and tolerate high temperatures （42 ℃）. Glucose was commonly carbohydrate used in selective media for Bifidobacteria. Production of titratable acidity and therefore lowering the pH varies from one strain to another.

关键词： Ecology Bifidobacterium antibiotic resistance kinetics of growth acidity.

Experimental Plans Method to Formulate a Resin Concrete

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Journal of Civil Engineering and Architecture 2012年第10期6卷 1376-1383页

作者： miloud Beddar Zinedine Boudaoud Mohamed Aziz Chikouche Halima Saadia M'hammedi Faculty of Technology Civil Engineering Department M'sila University M'sila 28000 Algeria Civil Engineering Department Oum Elbouaghi University OumElbouaghi 04000 Algeria

This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin （thermosetting resin） was used with two types of mineral fillers （dune sand and crushed sand）, and with the addition of a marble powder to ensure the continuity of the particle size mixing granular. The lack of the methods for developing this kind of composite materials, had led us to perform an initial experimental approach to define the experimental field, that is to say determine the mass proportions of the various compounds of mixture of our study. In the second approach, we have established and implemented fully experimental plans with three factors namely： factor （1）： sand, factor （2）： resin, factor （3）： marble powder. Test results being the density of polymer concrete and the mechanical resistances. Finally, multi-parameters regression allowed us to determine predictive mathematical models for the different responses of the study. Tests results showed that at three days we got a tensile strength of about 16 MPa with a resin concrete density of 1.9 g/cm3. This shows the advantages of this material.

关键词： Concrete polyester resin experimental plans method mechanical resistance

Effects of Cellulose Fiber Content on Mechanical and Electrical Properties of Polyurethane Based Composites

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材料科学与工程（中英文A版） 2013年第6期3卷 398-406页

作者： Aomar Hadjadj Fouad Malek El miloud Maafi Lan Tighzert Omar Jbara Jean-Luc Dellis Laboratory of Materials Science & Engineering (EA 4695) University of Reims Reims 51687 France Laboratory of Organic Macromolecular Chemistry and Natural Products (URAC 25) Faculty of Sciences Mohamed 1st University Oujda 60000 Morocco Laboratory of Condensed Matter Physics (EA 2081) University of Picardie Jules Vernes Amiens 80039 France