47 research outputs found

    Design and Optimization of a High Gain Multiband Patch Antenna for Millimeter Wave Application

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    This paper presents an enhanced Quadri-band microstrip patch antenna, using defective slots in the ground plane, designed to operate in the millimeter wave band, formulated using cavity model and simulated by an EM-simulator, based on finite element method: HFSSv15 (High Frequency Structure Simulator). The proposed antenna incorporates two symmetric patterns of “U” shaped slots with an “I” shaped slot engraved in the middle of the ground plane. The resulting antenna has four frequency bands; the first resonant frequency is located in the Ka band, at about 27Ghz, the second at nearly 35Ghz, the third at 41Ghz and the last one at 51GHz. Those resonant frequencies could be shifted by tuning the slots dimensions introduced if the ground plane of the proposed antenna .

    Phytochemical study and antibacterial activity of different extracts of Pistacia lentiscus L collected from Dahra Region West of Algeria

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    The purpose of this study was to investigate the phytochemical proprieties, antioxidant and antibacterial activities of different extracts of Pistacia lentiscus on two pathogenic bacteria. The concentration of total phenols was analyzed using Folin-Ciocalteu’s method. Exracts of plant were evaluated for their antimicrobial activities against Staphylococcus aureus and Esherichia coli using the agar disk diffusion method and the minimal inhibitory concentration. The phytochemical study revealed the presence of major bioactive chemical constituents in different extracts of P. lentiscus (flavonoids, alkaloids, saponins, tannins, terpenoids, glycosides and steroids). Results showed that this plant has antioxydant activity and high quantity of total phenols and flavonoids. Antibacterial activity of the aerial parts of P. lentiscus against tested bacteria has shown that Gram-negative strains were more resistant compared to the Gram- positive ones. We can conclude that Pistacia lentiscus from Dahra region under investigation can be a potential source of useful drugs.Keywords: Pistacia lentiscus; Phytochemicals; total phenol; Flavonoids; Antibacterial activit

    Cone Penetration Testing For Field Density Prediction

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    This paper summarizes an experimental program for developing a pilot procedure to check and predict field densities of compacted soils using static cone penetration tests. Three sandy soils were tested. The testing program included both laboratory and field tests. On the basis of laboratory tests, density prediction curves were developed while field results were used to find a correlation to predict densities on the basis of measured penetration resistances. The results are rather encouraging and promising. It is anticipated that the presented methodology would be very effective for compaction quality control in large areas of sandy soils because it is fast, simple and causes minimum disturbance to the compacted soil

    Using sterile insect technique against Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), in Yazd province, Iran

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    Carob moth, Ectomyelois ceratoniae (Zeller) (Lep.: Pyralidae), is the most important pest of pomegranate fruit in Iran where the cryptic activity of its larva makes the application of insecticides practically impossible. In this research, we evaluated the viability of the sterile insect technique against the carob moth in two isolated regions in Yazd province (Aqda and Mehriz). The mass rearing of the pest was performed in clean rooms on artificial diet under environmental conditions, 29±1 ºC and 75±5 %RH applying 165 Gy gamma ray as sterilizing doze. The sterile insects were released periodically in Aqda orchards (45 hectares) and in Chah Sheida (12 hectares) in Mehriz between March and November 2015. The infestation rate of carob moth in Aqda and Mehriz significantly reduced, in both target regions and control areas, by 12.27% and 44.02%, as well as 12.06% and 50.11%, for Aqda and Mehriz, respectively. It was concluded that periodical release of sterile carob moths can effectively lower the density of pest population and its economic loss on the harvest

    The Vascular Vegetation Populating the Flora in Building Materials of Historic Monuments Cities of the West Central Region of Morocco

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    6 páginas, 3 figuras y 1 tablaIn the concern of the preservation of the main historic monuments of the cities of Rabat and Sale (Morocco), a botanical study was conducted in 2009. The prospecting of these monuments allowed raising an inventory of the flora populating their building materials, and it has proved that this flora is rich and diversified. Indeed, it consists of 171 adventitious species distributed in 46 botanical families. The most represented families are Asteraceae, Poaceae, Fabaceae, Caryophyllaceae, Geraniaceae, Brassicaceae and Lamiaceae. They supply, to them only 49.7% of the specific size. The annual therophytes and the dicotyledon are dominant with respectively 66.7% and 84.7% of the specific size. Nevertheless, the presence of more than 20 species of trees and perennials constitutes a serious danger for bulwarks walls, especially by the phenomenon of fissuring by the action of the huge roots of these vegetables. These vegetables fitting into are placed on joints or cracks fissures have a chemical action on stones by acids that they release, and also a mechanical action by the growth of roots inside cracks fissures. They remain one of these are one of the important biological factors of the degradation of historic monuments. It is to note that the bulwarks walls of the site of Chella (Roman ruins) present more floral diversity than the other canvassed monuments (91 species) that are 53% of the total size.Peer reviewe

    REMOVAL OF COPPER IONS USING ALIQUAT 336/TBP BASED SUPPORTED LIQUID MEMBRANE

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    The sorption of copper (II) present in an aqueous media using a supported liquid membrane (SLM) by chloride tri-N-octylmethylammonium (Aliquat 336) and Tri-n-butylphosphate (TBP) from molar ratio 1:1, with polytetrafluoroethylene (PTFE) as a membrane support was studied. The effects of various parameters as initial pH, KSCN concentration and ammonium acetate concentration on the extraction yield were carried out. By a calculation program using CHEAQS V. L20.1, the determination of the percentages of the present species before and after extraction were given, in aqueous medium and on the membrane to be able to determine the relation between the nature of the extracted species and the extraction yield. The 23 factorial design achieve the best conditions of recovery procedure. The recovery of copper (II) is almost quantitative (94 %), in one step
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