31 research outputs found

    A Miniaturized Patch Antenna Designed and Manufactured Using Slot's Technique for RFID UHF Mobile Applications

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    In this research work, a novel compact antenna with rectangular slots is presented for radio frequency identification (RFID) handled applications in the ultrahigh frequency (UHF) band that can be manufactured and integrated into RFID readers without difficult. A prototype demonstrating the aforementioned features was constructed and measured. The proposed antenna is fed by 50-Ω coaxial cable and printed on a 1.6mm thick FR4 substrate which has a small size and occupies a volume of 68×66 ×1.6mm3. The patch, the feed-line and ground plane are made of PEC (Perfect Electric Conductor) with a thickness of 0.035 mm. Measured results indicate that the proposed antenna has a good impedance matching characteristic ranging from 889 to 939MHz, which covers the USA RFID-band (902–928MHz), the Chinese RFID-operating-band (920–924.5MHz), and the Korea and Japan RFID-band (917–923.5MHz). These results were achieved by the insertion of slots in the compact structure of the antenna. The electromagnetic simulators HFSS (High Frequency structure simulator) and CST (Computer Simulation Technology) microwave studio were used for the design, modeling and simulation of the antenna. The focus of the study of our antenna was on the parameters of return loss, bandwidth, Voltage Standing Wave Ratio (VSWR), input impedance and gain

    A Miniature RFID Antenna at UHF Band using Meander-Line Technique

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    This paper displays a new design of a small antenna proposed for radio-frequency identification (RFID) applications in the UHF band (ultra-high frequency). Our antenna is constituted of two rectangular patches linked together with a meander line. Using this technique reduction in antenna size of equal to 62% with respect to the conventional antenna was achieved. The antenna has a simple structure and small antenna size of 60 x 74mm2 or 0.184 λ0 x 0.226 λ0. It has been fabricated on a low-cost FR4 substrate and measured to validate the simulation performances.The measured bandwidth is around 54.4 MHz (889.3 - 943.7 MHz) with reflection coefficient less than 10 dB, which covers all of the American RFID band (902 - 928 MHz), Chinese RFID band (920.5 - 924.5 MHz), Korea Republic and Japan RFID band ( 917 - 923.5 MHz).The design and simulations have been effected by electromagnetic simulators HFSS and CST microwave studio. A good accord is getting between the simulated and measured results. This antenna is intended for the reader of RFID applications

    Geological and Geomorphological study of the original hill at the base of Fourth Dynasty Egyptian monuments. Etude géologique et géomorphologique de la colline originelle à la base des monuments de la quatrième dynastie égyptienne

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    22 pages; 20 figuresRock foundations of the Kephren and Kheops pyramids are examined in comparison with other Fourth Dynasty monuments: the Sphinx, Queen Kentkawes' mastaba and the Abu Rawash pyramid. This study is based on geological and geomorphological observations, visual observation, and photomontages. Results, correlated with those of former studies, demonstrate the existence of natural hills used as substrata in the construction of the two great pyramids. The minimum volume of these hills can be estimated at 12% and 23% respectively of the volumes of the Kephren and Kheops pyramids. The use of worked rock hills appears to be a characteristic of the construction methods under the Fourth Dynasty.Le substratum rocheux des pyramides de Kheops et Khephren est étudié en comparaison avec celui d'autres monuments de la quatrième dynastie de l'ancienne Egypte : le Sphinx, le mastaba de la reine Kentkawes et la pyramide d'Abu Rawash. Cette étude est basée sur des observations géologiques et géomorphologiques, l'observation visuelle et des photomontages, ainsi que des mesures réalisées sur le terrain. Les résultats, corrélés avec ceux d'études antérieures, démontrent l'existence de collines naturelles utilisées comme assises pour la construction des deux grandes pyramides. Le volume minimum de ces collines peut être estimé par rapport au volume total à 12% pour Khephren et 23% pour Kheops. L'utilisation de collines rocheuses pour asseoir la construction d'un monument apparaît être caractéristique des méthodes de construction utilisées sous la quatrième dynastie

    Conception d'antennes spirales rectangulaires pour TAG RFID UHF

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    La radio-identification, le plus souvent désignée par le sigle RFID (de l’anglais radio frequency identification), est une méthode pour mémoriser et récupérer des données à distance en utilisant des marqueurs appelés « radio-étiquettes » (« RFID tag » ou « RFID transponder » en anglais). Cette technologie d’identification peut être utilisée pour identifier les objets, les personnes et les carnivores domestiques. Dans cet article, nous nous intéressons à la conception d’antennes de tags RFID UHF passifs. Nous présentons d'abord le modèle rigoureux, basé sur la théorie de la diffraction par les fils fin. Modèle qui aboutit à une équation intégro-différentielle. La résolution de cette équation se fait par la méthode des moments. Bien que cette méthode soit en très bon accord avec la mesure, elle reste gourmande en temps de calcul et par conséquent ne permet pas d’estimer les paramètres des antennes des TAGs réelles présentant des géométries complexes. Pour cela, nous proposons une approche analytique, permettant de simplifier le calcul des paramètres des antennes spirales pour étiquette RFID sans avoir recours aux méthodes numériques rigoureuses. La validation expérimentale de ces modèles théoriques est réalisée au moyen d’un analyseur de réseaux. La confrontation théorie-expérience nous permet de tirer quelques conclusions intéressantes quant au nombre de boucles de la spirale et au choix du substrat diélectrique

    Microwave Imaging Approach for Breast Cancer Detection Using a Tapered Slot Antenna Loaded with Parasitic Components.

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    In this paper, a wideband antenna is proposed for ultra-wideband microwave imaging applications. The antenna is comprised of a tapered slot ground, a rectangular slotted patch and four star-shaped parasitic components. The added slotted patch is shown to be effective in improving the bandwidth and gain. The proposed antenna system provides a realized gain of 6 dBi, an efficiency of around 80% on the radiation bandwidth, and a wide impedance bandwidth (S11 < -10 dB) of 6.3 GHz (from 3.8 to 10.1 GHz). This supports a true wideband operation. Furthermore, the fidelity factor for face-to-face (FtF) direction is 91.6%, and for side by side (SbS) is 91.2%. This proves the excellent directionality and less signal distortion of the designed antenna. These high figures establish the potential use of the proposed antenna for imaging. A heterogeneous breast phantom with dielectric characteristics identical to actual breast tissue with the presence of tumors was constructed for experimental validation. An antenna array of the proposed antenna element was situated over an artificial breast to collect reflected and transmitted waves for tumor characterization. Finally, an imaging algorithm was used to process the retrieved data to recreate the image in order to detect the undesirable tumor object inside the breast phantom

    Enhancement of plant growth, acclimatization, salt stress tolerance and verticillium wilt disease resistance using plant growth-promoting rhizobacteria (PGPR) associated with plum trees (Prunus domestica)

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    Plants interact with a great variety of microorganisms that inhabit the rhizosphere playing critical roles in several aspects of plant growth and protection against abiotic and biotic diseases. In this study, we performed a screening of bacteria associated with the rhizosphere of Prunus domestica trees to identify bacterial strains with plant growth-promoting activity. Ten strains isolated from the rhizosphere of P. domestica showed multiple in vitro plant growth promoting rhizobacteria (PGPR) activity such as the production of indole acetic acid, hydrogen cyanide, ammonia, solubilization of phosphates and antifungal activity against Verticillium dalhiae and Fusarium oxysporum f.sp. melonis. In planta, they significantly increased the growth (stem length, number of leaflets, leaf area and root weight) and biochemical (nitrate reductase activity, proline and chlorophyll content) parameters of tomato, as well as the rate of seed germination. Two selected strains (Pr7 and Pr8) with higher antagonistic activity against V. dalhiae and F. oxysporum f.sp. melonis protected tomato plants against Verticillium wilt and salt stress. In addition, they enhanced acclimatization of Vitis vinifera cv. Pinot noir and the peach root stock GF305 from in vitro to the greenhouse. 16S rRNA sequencing identified strains Pr7 and Pr8 as Pseudomonas stutzeri and Bacillus toyonensis, respectively. Since these two PGPR inoculants exhibited multiple traits beneficial to the examined host plants, they may be applied in the development of safe, and effective seed treatments as an alternative to chemical fungicides and fertilization but also for successful acclimatization of micropropagated plants.Mohamed Faize was supported by funding from the ‘Ministère de l'Enseignement Supérieur, de la Recherche Scientifique de la Formation des Cadres’ (MERSFC, Morocco) within the framework of ARIMNet2 Projec

    Emissions of sulphur dioxide (SO2) from coal-fired power plants in Serbia and Bosnia-Herzegovina: First attempts of a validation of TROPOMI satellite products with airborne in situ measurements

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    The Western Balkan region is known for emitting alarmingly high sulphur dioxide amounts from coal-fired power plants. Though a number of environmental regulations have been introduced in recent years (e.g. desulphurisation installations, construction of modern power plants), the pollution burden is still much higher than recommended by the authorities. A number of different montoring systems are required to observe the growing pollution situation in the Western Balkan region, partly caused by a high energy demand from outside (e.g. Western Europe)

    El Nacionalsocialismo en el anime

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    Universidad de Sevilla. Grado en Lengua y Literaturas Alemana
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