1,011 research outputs found

    Microstrip Array Antenna using Series-Corporate Feed for Navigation System

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    In this paper, the proposed antenna consists of a single transmission line for 6-elements microstrip array antenna using Rogers RT5880 substrate material with a dielectric constant (εr) of 2.2 and thickness of 0.787 mm for navigation applications. The array structures of unequal patches placement are proposed with corporate feed line and H-shaped configurations are employed on the substrate and used the microstrip feed line with a corporate feed network excited via 50 Ω with T-junction method to control the feed for each group. 6-elements microstrip array antenna has operated at the resonant frequency of 1.27 GHz was obtained between the frequency from 1.2663 GHz to 1.2734 GHz where the S11-parameters of the structure designed and simulation below than <-10 dB. The analysis shows the antenna gain has increased 72.6% with high directivity as compared to single elements microstrip antenna. The radiation characteristics and other array parameters are evaluated with respect to the application requirements. However, circular polarization has obtained in 6-elements array antenna as the axial ratio is successfully achieved below than -3dB. The antenna efficiency, the current distribution, VSWR, and S11-parameters of the proposed 6-elements CP microstrip array antenna have been presented and discussed in detail. The design methodology and the measurement results have been presented and discussed in this paper

    Irreducible representations of the braid group B3B_3 in dimension 6

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    We use qq-Pascal's triangle to define a family of representations of dimension 6 of the braid group B3B_3 on three strings. Then we give a necessary and sufficient condition for these representations to be irreducible

    B3B_3 block representations of dimension 6 and braid reversions

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    We construct a family of six dimensional block representations of the braid group B3B_3 on three strings. We show that these representations can be used to distinguish braids of knots with 9 and 10 crossings from their reversed braids

    Prevalence and Characterization of Hepatitis B and Hepatitis C Infection among Blood Donors in Erbil

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    Blood transmitting infectious disease still remains a considerable global health problem. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are two of the most commonly transmitted infectious agents. This prospective cross-sectional study was conducted between December, 2017, and February, 2018, at the Directorate of Blood Bank in Erbil Province, Northern Iraq. During that period, a total of 6173 blood donors donated blood; all blood donors were asked a series of questions through a structured questionnaire designed for such purpose. These patients were serologically examined for HBV and HCV. Positive blood samples were further analyzed serologically and confirmed by real-time polymerase chain reaction (RT-PCR). Among 6173 blood donors who were investigated for HBV, 7 (0.11%) and 98 (1.6%) were positive for hepatitis B urface antigen (HBs-Ag) and hepatitis B core Antibody (HBc-Ab), respectively, whereas during screening for HCV, 4 (0.06%) were positive for HCV-Ab. Coinfection (dual infection (HBV and HCV) was positive in 1 patient (0.01%). Among 98 reactive samples, 75.5% were positive for HBs antibody (HBs-Ab), the remaining 24 samples (24.5%) were regarded as occult hepatitis B infection (OBI), since they were positive for HBc-Ab, whereas negative both for HBs-Ag and HBs-Ab. The diagnosis of OBI could be confirmed by RT-PCR in 8 samples, 33% of samples. The overall incidence of HBV and HCV among examined blood donors was 0.5 %, and 0.06%, respectively. Amidst that incidence, 0.39 % were diagnosed as OBI. To prevent viral transmission through blood transfusion is needed to combine a different and sensitive method for HBV detection as well as volve tests that have high sensitivity and specificity for serological markers. Moreover, a molecular tool that is sensitive enough to detect very low copies of viral DNA must also be developed

    Effects of advera® warm mix additive on the rheological properties of unaged and short term aged asphalt binders

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    The performance of asphalt pavement is mainly governed by the properties of the binder. Many asphalt pavement distress are pronounced to be related to the rheological properties of asphalt binder. The oxidation changes the structure and composition of asphalt binder resulting stiffer and brittle of asphalt. This paper described SuperpaveTM binder that was used to characterize the rheological properties of PG64 asphalt binders blended with various Advera® contents subjected to unaged and short term aged. Rotational viscometer (RV) and Dynamic Shear Rheometer (DSR) were conducted to measure binder properties at higher and intermediate temperature respectively. The results indicated that, the addition of Advera® in the asphalt binder exhibited change in binder rheology which influenced rutting parameteryKeywords: Advera®; Aging; Viscosity; Rotational viscometer; Dynamic shear rheometer

    Full Spectroscopic Model and Trihybrid Experimental-Perturbative-Variational Line List for ZrO

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    Zirconium monoxide (ZrO) absorption lines define rare S-type stars and are currently being sought on exoplanets. Successful detection is dependent on an accurate and comprehensive line list, with existing data not ideal for many applications. Specifically, the Plez \etal{} line list is near-complete but has insufficient accuracy for high-resolution cross-correlation, while the Sorensen \& Bernath data has high accuracy but only considers a small number of spectral bands. This article presents a novel spectroscopic model, variational line list and trihybrid line list for the main \ZrO{} isotopologue, as well as isotopologue-extrapolated hybrid line lists for the \isoa{}, \isob{}, \isoc{}, \isod{}~and \isoe{} isotopologues. These were constructed using \DUO{} based on icMRCI-SD/CASSCF~\abinitio{} electronic data calculated using \MOLPRO{}, experimental energies obtained from a previous \Marvel{} data compilation and perturbative energies from Sorensen \& Bernath. The new \ZrO{} \EXOMOL{}-style trihybrid line list, \LLname{}, comprises \noenergies{} energies (\noMaenergies{} experimental) and \notransitions{} transitions up to 30,000~\cm{} (333~nm) between ten low-lying electronic states (\ZrOX{}, \ZrOaa{}, \ZrOA{}, \ZrObb{}, \ZrOB{}, \ZrOC{}, \ZrOdd{}, \ZrOee{}, \ZrOff{} and \ZrOF{}). The inclusion of experimental energy levels in \LLname{} means ZrO will be much easier to detect using high-resolution ground-based telescopes in the 12,500 -- 17,500~\cm{} (571 -- 800~nm) spectral region. The inclusion of variational energy levels means that the ZorrO line list has very high completeness and can accurately model molecular absorption cross-sections even at high temperatures. The \LLname{} data will hopefully facilitate the first detection of ZrO in the atmosphere of a hot Jupiter exoplanet, or alternatively more conclusively exclude its presence
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