2,047 research outputs found

    Strangeness production at finite temperature and baryon density in an effective relativistic mean field model

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    We study the strangeness production in hot and dense nuclear medium, by requiring the conservation of the baryon density, electric charge fraction and zero net strangeness. The hadronic equation of state is investigated by means of an effective relativistic mean field model, with the inclusion of the full octet of baryons and kaon mesons. Kaons are considered taking into account of an effective chemical potential depending on the self-consistent interaction between baryons. The obtained results are compared with a minimal coupling scheme, calculated for different values of the anti-kaon optical potential and with non-interacting kaon particles. In this context, we also consider the possible onset of the kaon condensation for a wide range of temperatures and baryon densities.Comment: 13 pages, 6 figure

    On the prediction of turbulent secondary flows

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    The prediction of turbulent secondary flows, with Reynolds stress models, in circular pipes and non-circular ducts is reviewed. Turbulence-driven secondary flows in straight non-circular ducts are considered along with turbulent secondary flows in pipes and ducts that arise from curvature or a system rotation. The physical mechanisms that generate these different kinds of secondary flows are outlined and the level of turbulence closure required to properly compute each type is discussed in detail. Illustrative computations of a variety of different secondary flows obtained from two-equation turbulence models and second-order closures are provided to amplify these points

    A piecewise-linear reduced-order model of squeeze-film damping for deformable structures including large displacement effects

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    This paper presents a reduced-order model for the Reynolds equation for deformable structure and large displacements. It is based on the model established in [11] which is piece-wise linearized using two different methods. The advantages and drawbacks of each method are pointed out. The pull-in time of a microswitch is determined and compared to experimental and other simulation data.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    Dosis de azufre y tiempos de aplicación en el rendimiento y la calidad del aceite de canola cultivada en suelo calcáreo

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    Pakistan has been constantly deficient in its oil seed production and it is very difficult to meet the edible oil requirement of its ever-increasing population. A field experiment was conducted at the Agronomy Research Farm, The University of Agriculture Peshawar, Northern Pakistan during winter (2013–14). Five sulphur levels (15, 30, 45, 60 and 75 kg·ha-1) and times of application (at seedling, bolting and flowering stages) were used for the canola variety Abasin-95. The experiment was laid out in a randomized complete block design replicated four times on a 5 m × 3.2 m plot size. The results showed that the sulphur-applied plots gave the highest seed yield, biological yield, glucosinolate, erucic acid, oil content, protein content, oleic acid and linoleic acid compared to the control plots. Sulphur applied at the rate of 60 kg·ha-1 and applied at the bolting stage increased seed yield, biological yield, oil content, and protein content.Pakistán ha sido constante y crónicamente deficiente en producción de semillas oleaginosas y es muy difícil cumplir con la demanda de aceites comestibles para una población cada vez mayor. Se realizó un experimento de campo en la granja de investigación agronómica de la Universidad de Agricultura Peshawar, en el norte de Pakistán, durante el invierno (2013–14). Los cinco niveles de azufre (15, 30, 45, 60 y 75 kg·ha-1) y su tiempo de aplicación (en las etapas de plántula, floración y floración) se utilizaron para la variedad de canola (Abasin-95). El experimento se realizó en un diseño de bloques completos al azar que se replicó cuatro veces con un tamaño de parcela de 5 m × 3,2 m. Los resultados mostraron que las parcelas aplicadas con azufre dieron el mayor rendimiento de semilla, rendimiento biológico, glucosinolato, ácido erúcico, contenido de aceite, contenido de proteína, ácido oleico y ácido linoleico en comparación con las parcelas de control. El azufre se aplicó en una tasa de 60 kg·ha-1 y se aplicó en la etapa de empernado, incrementando el rendimiento de las semillas, el rendimiento biológico, el contenido de aceite y el contenido de proteínas

    Comparative performance of optical amplifiers: Raman and EDFA

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    The in-line optical signal amplification is often used in optical communication systems to accomplish longer transmission distances and larger capacity. In this proposed paper, the operation of two types of optical amplifiers for 16×10 Gbps wavelength division multiplexing system had been examined by changing transmission distance from 10 to 200 km with a dispersion equals to 16.75 ps/nm/km. The analysis and design of such systems ordinarily includes many signal channels, nonlinear devices, several topologies with many noise sources, is extremely complex and effort-exhaustive. Therefore, theoretical studies with simulation CAD software of systems are become necessity to predict and optimize system performance. The comparison between EDFA and Raman has already explored by many researchers in varying ways in this work and to achieve obove objectives, the OptiSystem software was used to design the proposed fiber optic communications system and to simulate results. Performance for the present system was evaluated for parameters like bit error rate (BER), quality factor (QF), total gain with eye opening factor. It was saw that EDFA provides better results, in the maximal transmission distance 64% better than Raman amplifier, 57.5% for gain and 26.7% for maximum quality factor. As a future study a hybrid amplifier can produce better quality of amplification

    SOME OBSERVATIONS ON FISHES AND THEIR PARASITES OF DARBANDIKHAN LAKE, KURDISTAN REGION IN NORTH IRAQ

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    A total of 255 freshwater fishes, belonging to 17 species, namely: Barbus barbulus, B. grypus, Capoeta trutta, Capoeta umbla, Carasobarbus luteus, Carassius auratus, Chondrostoma regium, Cyprinion macrostomum, Cyprinus carpio, Garra rufa, Hemiculter leucisculus, Hypophthalmichthys molitrix, Luciobarbus esocinus, Squalius lepidus (Family Cyprinidae), Mystus pelusius (Bagridae), Silurus triostegus (Siluridae) and Mastacembelus mastacembelus (Mastacembelidae), were collected from Darbandikhan Lake, southeast of Sulaimani city, Kurdistan region, Iraq, from March 2012 to the end of October 2012. The fishes were examined for ectoparasites and endoparasites. The study revealed the existence of 45 species of parasites including: seven species of protozoans, 29 species of monogeneans, two species of trematodes, one species each of cestode and nematode, two species of acanthocephalans and three species of crustaceans. The present study revealed that Dactylogyrus suchengtaii and D. carassobarbi were the most parasites prevalent (100% and 90.90%, respectively) in the lake, while Scyphidia arctica was scarce (1.44%). The fish C. trutta was highly infected with parasites (nine species), followed by S. lepidus (eight species) and both C. luteus and M. mastacembelus (six species each), while G. rufa and H. molitrix were less infected (one species each). The ciliated protozoan Ichthyophthirius multifiliis was recorded on seven species of fishes with prevalence ranged between 2.89% and 23.52%, followed by the crustacean Lernaea cyprinacea which was recorded on four species of fishes (5% - 27.27%)

    SOME OBSERVATIONS ON FISHES AND THEIR PARASITES OF DARBANDIKHAN LAKE, KURDISTAN REGION IN NORTH IRAQ

    Get PDF
    A total of 255 freshwater fishes, belonging to 17 species, namely: Barbus barbulus, B. grypus, Capoeta trutta, Capoeta umbla, Carasobarbus luteus, Carassius auratus, Chondrostoma regium, Cyprinion macrostomum, Cyprinus carpio, Garra rufa, Hemiculter leucisculus, Hypophthalmichthys molitrix, Luciobarbus esocinus, Squalius lepidus (Family Cyprinidae), Mystus pelusius (Bagridae), Silurus triostegus (Siluridae) and Mastacembelus mastacembelus (Mastacembelidae), were collected from Darbandikhan Lake, southeast of Sulaimani city, Kurdistan region, Iraq, from March 2012 to the end of October 2012. The fishes were examined for ectoparasites and endoparasites. The study revealed the existence of 45 species of parasites including: seven species of protozoans, 29 species of monogeneans, two species of trematodes, one species each of cestode and nematode, two species of acanthocephalans and three species of crustaceans. The present study revealed that Dactylogyrus suchengtaii and D. carassobarbi were the most parasites prevalent (100% and 90.90%, respectively) in the lake, while Scyphidia arctica was scarce (1.44%). The fish C. trutta was highly infected with parasites (nine species), followed by S. lepidus (eight species) and both C. luteus and M. mastacembelus (six species each), while G. rufa and H. molitrix were less infected (one species each). The ciliated protozoan Ichthyophthirius multifiliis was recorded on seven species of fishes with prevalence ranged between 2.89% and 23.52%, followed by the crustacean Lernaea cyprinacea which was recorded on four species of fishes (5% - 27.27%)

    Performance of Spatial Modulation using Measured Real-World Channels

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    In this paper, for the first time real-world channel measurements are used to analyse the performance of spatial modulation (SM), where a full analysis of the average bit error rate performance (ABER) of SM using measured urban correlated and uncorrelated Rayleigh fading channels is provided. The channel measurements are taken from an outdoor urban multiple input multiple output (MIMO) measurement campaign. Moreover, ABER performance results using simulated Rayleigh fading channels are provided and compared with a derived analytical bound for the ABER of SM, and the ABER results for SM using the measured urban channels. The ABER results using the measured urban channels validate the derived analytical bound and the ABER results using the simulated channels. Finally, the ABER of SM is compared with the performance of spatial multiplexing (SMX) using the measured urban channels for small and large scale MIMO. It is shown that SM offers nearly the same or a slightly better performance than SMX for small scale MIMO. However, SM offers large reduction in ABER for large scale MIMO.Comment: IEEE Vehicular Technology Conference Fall 2013 (VTC-Fall 2013), Accepte

    Assessment of biodiversity based on morphological characteristics and RAPD markers among genotypes of wild rose species

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    Conservation and utilization of the native plant resources is essential for long term sustainability of biodiversity. Wild native resources are adapted to specific and diverse environmental conditions and therefore, these adaptive features can be introduced into modern cultivars either through conventional breeding or advanced molecular genetic techniques. Understanding the genetic make up of the wildly growing plant species and of target desirable genes is a prerequisite for this purpose. Five wild rose (Rosa L.) genotypes were collected from different locations in northern hilly areas of Pakistan for this study. Different morphological characteristics and PCR based random amplified polymorphic DNA (RAPD) technique was used to find out the diversity and relationship among the genotypes. On morphological basis, Rosa webbiana collected from Muree and Nathia gali showed maximum (83%) similarity, whereas on DNA pattern basis, Rosa brunonii collected from Bansra gali and Sunny bank showed maximum (72%) similarity, while R. webbiana showed maximum diversity among all the species.Key words: Genetic diversity, morphological differences, random amplified polymorphic DNA (RAPD), Rosa
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