2,291 research outputs found

    Performance Improvement of QPSK Signal Predetection EGC Diversity Receiver

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    This paper proposes a modification of quadrature phase-shift-keying (QPSK) signal diversity reception with predetection equal gain combiner (EGC). The EGC combining is realized by using the constant modulus algorithm (CMA). Carrier synchronization is performed by the phase locked loop (PLL). Comparative analysis of the modified and ordinary diversity receiver in the presence of carrier frequency offset in the additive white Gaussian noise (AWGN) channel, as well as in Rician fading channel is shown. The proposed diversity receiver allows significant frequency offset compared to the diversity receiver that uses only PLL, and the error probability of the proposed receiver is very close to the error probability of the receiver with only PLL and zero frequency offset. The functionality of the proposed diversity receiver, as well as its properties is experimentally verified on a system based on universal software radio peripheral (USRP) hardware. The performed comparison confirms the expected behavior of the system

    Heavy Quark Radiative Energy Loss - Applications to RHIC

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    Heavy quark energy loss in a hot QCD plasma is computed taking into account the competing effects due to suppression of zeroth order gluon radiation bellow the plasma frequency and the enhancement of gluon radiation due to transition energy loss and medium induced Bremsstrahlung. Heavy quark medium induced radiative energy loss is derived to all orders in opacity, (L/λg)n(L/\lambda_g)^n. Numerical evaluation of the energy loss suggest small suppression of high pp_\perp charm quarks, and therefore provide a possible explanation for the null effects observed by PHENIX in the prompt electron spectrum in Au+AuAu+Au as s=130\sqrt{s}=130 and 200 AGeV.Comment: 4 pages, 4 figures, Contributed to 17th International Conference on Ultra Relativistic Nucleus-Nucleus Collisions (Quark Matter 2004), Oakland, California, 11-17 Jan 200

    Nutrition Specificities of Goat Kids in Suckling Period

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    In this paper the up to date methods and regulation of goat kids feeding as the new normatives and nutrient requirements are presented. In kids feeding remarkable attention has to be made on optimal needs concerning the accurate growth and progress. In order to make the best solution the updated normatives with large number of parameters have to be used. Growing goat kids require energy, protein, vitamins and minerals for optimum growth. Determining quantities of these nutrients needed will make possible to determine how much of grain mix and hay should be used to support maintenance and growth. The nutrient requirements of growing goats show a different trend than those of mature animals. The latest investigation results on protein level recommendation in kids feeding (NRC, 2007) have grown over 45%, while energy needs only infinitesimally more in regard to goat nutrient requirement needs considering the NRC recommendation from 1981. However, it must be remembered that energy requirements are based on minimal activity needed to secure feed and the actual requirement may very. Thus, the needs of energy for growing kids with a body mass of 20 kg is 5.69 MJ ME and 75.6 g in proteins. The first three days after birth are the most critical days in the life of a newborn kid. If the mother rejects the kids, colostrum of kids should be fed three times a day, a total of 2 to 3 pint per day. After three days, the kid diet is based on milk or milk replacer, which is given twice a day and does not exceed three liters per day. Feeding with milk or milk replacer may continue until 8-12 weeks or until the time the kids are weaned and able to consume 0.2 kg grain milk per day. At weaning, for feeding the 30 days old kids we used a mixture concentrate for early suckling kids. By own nutrient compounds this grain mixtures must have better quality than concentrate mixtures used in goat kids feeding. Provide a grain mix (kid starter) containing high levels of protein (16%) and high levels of fiber (11%) as well as good quality hay to encourage rumen development. After weaning up to 6 months, continue feeding with kid starter 0.2 to 0.4 kg/day and plenty of good quality forage and pasture. When the growing kids start to use large amounts of hay or green forage in feeding, they should be given a mixture of concentrate with something simpler composition. Do not feed silage and non-protein nitrogen at this age

    Detailed characterization of the O-linked glycosylation of the neuropilin-1 c/MAM-domain

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    Neuropilins are involved in angiogenesis and neuronal development. The membrane proximal domain of neuropilin-1, called c or MAM domain based on its sequence conservation, has been implicated in neuropilin oligomerization required for its function. The c/MAM domain of human neuropilin-1 has been recombinantly expressed to allow for investigation of its propensity to engage in molecular interactions with other protein or carbohydrate components on a cell surface. We found that the c/MAM domain was heavily O-glycosylated with up to 24 monosaccharide units in the form of disialylated core 1 and core 2 O-glycans. Attachment sites were identified on the chymotryptic c/MAM peptide ETGATEKPTVIDSTIQSEFPTY by electron-transfer dissociation mass spectrometry (ETD-MS/MS). For highly glycosylated species consisting of carbohydrate to about 50 %, useful results could only be obtained upon partial desialylation. ETD-MS/MS revealed a hierarchical order of the initial O-GalNAc addition to the four different glycosylation sites. These findings enable future functional studies about the contribution of the described glycosylations in neuropilin-1 oligomerization and the binding to partner proteins as VEGF or galectin-1. As a spin-off result the sialidase from Clostridium perfringens turned out to discriminate between galactose- and N-acetylgalactosamine-linked sialic acid

    Diagnosing Energy Loss: PHENIX Results on High-pT Hadron Spectra

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    Measurements of inclusive spectra of hadrons at large transverse momentum over a broad range of energy in different collision systems have been performed with the PHENIX experiment at RHIC. The data allow to study the energy and system size dependence of the suppression observed in RAA of high-pT hadrons at sqrt(s_NN)= 200 GeV. Due to the large energy range from sqrt(s_NN)= 22 GeV to 200 GeV, the results can be compared to results from CERN SPS at a similar energy. The large Au+Au dataset from the 2004 run of RHIC also allows to constrain theoretical models that describe the hot and dense matter produced in such collisions. Investigation of particle ratios such as eta/pi0 helps understanding the mechanisms of energy loss.Comment: 4 pages, 6 figures. To appear in the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006), Shanghai, China, November 14-20, 200

    Effects of Imperfect Reference Signal Recovery on Performance of SC and SSC Receivers over Generalized Fading Channels

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    This paper presents the study of the effects of imperfect reference signal recovery on the bit error rate (BER) performance of dual-branch switch-and-stay combining (SSC) and multibranch selection combining (SC) receivers in a generalized - fading channel. The average BER of binary and quaternary phase shift keying (BPSK and QPSK) is derived under the assumption that the reference carrier signal is extracted from the received modulated signal. For SSC receiver the optimal switching threshold (in a minimum BER sense) is numerically evaluated. Hereby we determine and discuss the simultaneous influence of the average signal-to-noise ratio (SNR) per bit, fading severity, product phase-locked loop (PLL) bandwidthbit duration (B_LT_b), switching threshold of SSC and diversity order of SC on BER performance. The influence of B_LT_b in different channel conditions and modulation formats is pointed out. The numerical results are confirmed by computer simulations

    Outage Probability Analysis of Mixed RF-FSO System Influenced by Fisher-Snedecor Fading and Gamma-Gamma Atmospheric Turbulence

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    In this paper, we investigate a dual-hop relaying system, composed of radio frequency (RF) and free-space optical (FSO) link. Decode-and-forward (DF) relay is employed to integrate the first RF link and the second line-of-sight FSO links. The RF channel is assumed to be subject to recently proposed Fisher-Snedecor fading model, which was shown to be convenient for modeling in realistic wireless communication scenarios. The FSO channel is affected by Gamma-Gamma distributed atmospheric turbulence. Expression for the outage probability is derived and utilized to present numerical results. Based on presented results, the effects of various RF and FSO channels parameters on the overall system performance are examined and discussed.Comment: Presented at 2018 26th Telecommunications Forum (TELFOR

    A hybrid metal/semiconductor electron pump for quantum metrology

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    Electron pumps capable of delivering a current higher than 100pA with sufficient accuracy are likely to become the direct mise en pratique of the possible new quantum definition of the ampere. Furthermore, they are essential for closing the quantum metrological triangle experiment which tests for possible corrections to the quantum relations linking e and h, the electron charge and the Planck constant, to voltage, resistance and current. We present here single-island hybrid metal/semiconductor transistor pumps which combine the simplicity and efficiency of Coulomb blockade in metals with the unsurpassed performances of silicon switches. Robust and simple pumping at 650MHz and 0.5K is demonstrated. The pumped current obtained over a voltage bias range of 1.4mV corresponds to a relative deviation of 5e-4 from the calculated value, well within the 1.5e-3 uncertainty of the measurement setup. Multi-charge pumping can be performed. The simple design fully integrated in an industrial CMOS process makes it an ideal candidate for national measurement institutes to realize and share a future quantum ampere

    Paleolinguistics brings more light on the earliest history of the traditional Eurasian pulse crops

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    Traditional pulse crops such as pea, lentil, field bean, bitter vetch, chickpea and common vetch originate from Middle East, Mediterranean and Central Asia^1^. They were a part of human diets in hunter-gatherers communities^2^ and are one of the most ancient cultivated crops^3,4^. Europe has always been rich in languages^5^, with individual families still preserving common vocabularies related to agriculture^6,7^. The evidence on the early pulse history witnessed by the attested roots in diverse Eurasian proto-languages remains insufficiently clarified and its potential for supporting archaeobotanical findings is still non-assessed. Here we show that the paleolinguistic research may contribute to archaeobotany in understanding the role traditional Eurasian pulse crops had in the everyday life of ancient Europeans. It was found that the Proto-Indo-European language^8,9^ had the largest number of roots directly related to pulses, such as *arnk(')- (a leguminous plant), *bhabh- (field bean), *erəgw[h]- (a kernel of leguminous plant; pea), *ghArs- (a leguminous plant), *kek-, *k'ik'- (pea) and *lent- (lentil)^10,11,12^, numerous words subsequently related to pulses^13,14^ and borrowings from one branch to another^15^, confirming their essential place in the nutrition of Proto-Indo-Europeans^16,17,18^. It was also determined that pea was the most important among Proto-Uralic people^19,20,21^, while pea and lentil were the most significant in the agriculture of Proto-Altaic people^22,23,24^. Pea and bean were most common among Caucasians^25,26^, Basques^27,28^ and their hypothetical common forefathers^29^ and bean and lentil among the Afro-Asiatic ancestors of modern Maltese^30^. Our results demonstrate that pulses were common among the ancestors of present European nations and that paleolinguistics and its lexicological and etymological analysis may be useful in better understanding the earliest days of traditional Eurasian crops. We believe our results could be a basis for advanced multidisciplinary approach to the pulse crop domestication, involving plant scientists, archaeobotanists and linguists, and for reconstructing even earlier periods of pulse history

    The effect of inclusion of inlets in dual drainage modelling

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.In coupled sewer and surface flood modelling approaches, the flow process in gullies is often ignored although the overland flow is drained to sewer network via inlets and gullies. Therefore, the flow entering inlets is transferred to the sewer network immediately, which may lead to a different flood estimation than the reality. In this paper, we compared two modelling approach with and without considering the flow processes in gullies in the coupled sewer and surface modelling. Three historical flood events were adopted for model calibration and validation. The results showed that the inclusion of flow process in gullies can further improve the accuracy of urban flood modelling.The research is partially funded by the SINATRA project which is supported by the United Kingdom NERC Flooding from Intense Rainfall programme (grant NE/K008765/1)
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