378 research outputs found

    Phenology and Ripening of Vitis vinifera L. and Vitis labrusca L. Varieties in the Maritime Climate of Samsun in Turkey’s Black Sea Region

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    Heavy rainfall in Turkey’s northern Black Sea Region in spring and autumn, combined with insufficientsunshine during the vegetation period, results in poor ripening of European grape (Vitis vinifera L.)cultivars. Compared to other coastal provinces in the Central and Eastern Black Sea Region, Samsunreceives relatively little rainfall. This study evaluated the adaptation of Vitis vinifera L. and Vitis labruscaL. grapes to Samsun by examining the phenology and ripening characteristics of these cultivars in2010 and 2011 and calculating climatic indices using long-term data for Samsun in order to assess thepotential for viticulture in the area. The following climatic characteristics were identified: annual sunshineduration, 1 836 hours; Branas Heliothermic Index (BHI), 3.0; Hydrothermic Index (HyI), 4 053.7°C mm;Winkler Index (WI growing degree days) 1 832/Region III “Warm”; and Huglin Index (HI) 1 978°C/HI-1“Temperate”. Phenological cycles (budburst to harvest) varied between 120 and 176 days, with TrakyaÄ°lkeren and Yalova Ä°ncisi the most precocious varieties and Favli the latest variety in both years. Heatsummation requirements ranged from 1 210 to 1 844 GDD, with Trakya Ä°lkeren requiring the least andNarince the most heat summation. Total soluble solid (TSS) values ranged from 15.1 °Brix (Trakya Ä°lkeren)to 21.4 °Brix (Labrusca). Although Favli was the last to ripen, the TSS value for this variety was only 17.1%.These findings indicate that, with the exception of Favli, all the varieties examined are capable of maturingunder the climatic conditions in the study area, suggesting that the coastal areas of Samsun province aresuitable for early and mid-season Vitis vinifera L. grape viticulture

    Marginally low mass ratio close binary system V1191 Cyg

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    In this study, we present photometric and spectroscopic variations of the extremely small mass ratio (q≃0.1q\simeq 0.1) late-type contact binary system \astrobj{V1191 Cyg}. The parameters for the hot and cooler companions have been determined as MhM_\textrm{h} = 0.13 (1) M⊙M_{\odot}, McM_\textrm{c} = 1.29 (8) M⊙M_{\odot}, RhR_\textrm{h} = 0.52 (15) R⊙R_{\odot}, RcR_\textrm{c} = 1.31 (18) R⊙R_{\odot}, LhL_\textrm{h} = 0.46 (25) L⊙L_{\odot}, LcL_\textrm{c} = 2.71 (80) L⊙L_{\odot}, the separation of the components is aa= 2.20(8) R⊙R_{\odot} and the distance of the system is estimated as 278(31) pc. Analyses of the times of minima indicates a period increase of dPdt=1.3(1)×10−6\frac{dP}{dt}=1.3(1)\times 10^{-6} days/yr that reveals a very high mass transfer rate of dMdt=2.0(4)×10−7\frac{dM}{dt}=2.0(4)\times 10^{-7}M⊙M_{\odot}/yr from the less massive component to the more massive one. New observations show that the depths of the minima of the light curve have been interchanged.Comment: Accepted for publication in New Astronomy, 16 pages, 2 figures, 4 table

    Close Binary System GO Cyg

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    In this study, we present long term photometric variations of the close binary system \astrobj{GO Cyg}. Modelling of the system shows that the primary is filling Roche lobe and the secondary of the system is almost filling its Roche lobe. The physical parameters of the system are M1=3.0±0.2M⊙M_1 = 3.0\pm0.2 M_{\odot}, M2=1.3±0.1M⊙M_2 = 1.3 \pm 0.1 M_{\odot}, R1=2.50±0.12R⊙R_1 = 2.50\pm 0.12 R_{\odot}, R2=1.75±0.09R⊙R_2 = 1.75 \pm 0.09 R_{\odot}, L1=64±9L⊙L_1 = 64\pm 9 L_{\odot}, L2=4.9±0.7L⊙L_2 = 4.9 \pm 0.7 L_{\odot}, and a=5.5±0.3R⊙a = 5.5 \pm 0.3 R_{\odot}. Our results show that \astrobj{GO Cyg} is the most massive system near contact binary (NCB). Analysis of times of the minima shows a sinusoidal variation with a period of 92.3±0.592.3\pm0.5 years due to a third body whose mass is less than 2.3M⊙M_{\odot}. Finally a period variation rate of −1.4×10−9-1.4\times10^{-9} d/yr has been determined using all available light curves.Comment: Accepted for publication in New Astronomy, 18 pages, 4 figures, 7 table

    Absolute properties of the binary system BB pegasi

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    We present ground-based photometry of the low-temperature contact binary BB Peg. We collected all the times of mid-eclipse available in the literature and combined them with those obtained in this study. Analyses of the data indicate a period increase of (3.0 ± 0.1) × 10-8 days yr -1. This period increase of BB Peg can be interpreted in terms of the mass transfer 2.4 × 10-8 M⊙ yr-1 from the less massive to the more massive component. The physical parameters have been determined as Mc = 1.42M⊙, Mh = 0.53 M⊙, Rc = 1.29 R⊙, Rh, = 0.83 R⊙, Lc = 1.86 L⊙, and L h = 0.94 L⊙ through simultaneous solutions of light and of the radial velocity curves. The orbital parameters of the third body, which orbits the contact system in an eccentric orbit, were obtained from the period variation analysis. The system is compared to the similar binaries in the Hertzsprung-Russell and mass-radius diagrams.Ege University Research Fund and TÜBÄ°TAK National Observator

    Absolute properties of the binary system BB Pegasi

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    We present a ground based photometry of the low-temperature contact binary BB Peg. We collected all times of mid-eclipses available in literature and combined them with those obtained in this study. Analyses of the data indicate a period increase of 3.0(1) x 10^{-8} days/yr. This period increase of BB Peg can be interpreted in terms of the mass transfer 2.4 x 10^{-8} Ms yr^{-1} from the less massive to the more massive component. The physical parameters have been determined as Mc = 1.42 Ms, Mh = 0.53 Ms, Rc = 1.29 Rs, Rh = 0.83 Rs, Lc = 1.86 Ls, and Lh = 0.94 Ls through simultaneous solution of light and of the radial velocity curves. The orbital parameters of the third body, that orbits the contact system in an eccentric orbit, were obtained from the period variation analysis. The system is compared to the similar binaries in the Hertzsprung-Russell and Mass-Radius diagram.Comment: 17 pages, 3 figures, accepted for Astronomical Journa

    Use of social networking in the Middle East: student perspectives in higher education

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    This study aims to determine the benefits, risks, awareness, cultural factors, and sustainability, allied to social networking (SN) use in the higher education (HE) sector in Middle Eastern countries, namely Jordan, Saudi Arabia, and Turkey. Using an online survey, 1180 complete responses were collected and analyzed using the statistical confirmatory factor analysis method. The use of SN in the Middle Eastern HE sector has the capacity to promote and motivate students to acquire professional and personal skills for their studies and future workplace; however, the use of SN by tertiary students is also associated with several risks: isolation, depression, privacy, and security. Furthermore, culture is influenced by using SN use, since some countries shifted from one dimension to another based on Hofstede's cultural framework. The study new findings are based on a sample at a specific point in time within a culture. The study findings encourage academics to include SN in unit activities and assessments to reap the benefits of SN, while taking steps to mitigate any risks that SN poses to students. Although other studies in the Middle East examined the use of Learning Management System and Facebook in, HE as a means of engaging students in discussions and communications, however, this study contributes a better understanding of the benefits and risks, awareness, culture, and sustainability, associated with the use of SN in the HE sector in the Middle East. Finally, the paper concludes with an acknowledgment of the study limitations and suggestions for future research

    Presentation and management of keloid scarring following median sternotomy: a case study

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    <p>Abstract</p> <p>Introduction</p> <p>Keloid scars following median sternotomy are rare and occur more frequently in pigmented skin. Different management strategies have been described with variable success. We present a case of keloid scar formation following cardiac surgery including our management and the final aesthetic result.</p> <p>Case description</p> <p>A 64 year old female of fair complexion underwent mitral valve replacement. The procedure and postoperative recovery were uncomplicated, however, during the following year, thick keloid scars formed over the incision sites. Initial non surgical measures failed to relieve pain and did not offer any tangible aesthetic benefit. Eventually surgical excision was attempted. She presented to our clinic for nine months follow up with significant improvement in pain and aesthetic result.</p> <p>Discussion and Evaluation</p> <p>Several theories have attempted to explore the pathophysiology of keloid scar formation. A number of predisposing factors have been documented however none existed in this case. A variety of invasive and non invasive approaches have been described but significant differences in success rates and methodology of investigations still precludes a standardized management protocol.</p> <p>Conclusions</p> <p>In this case study a rare presentation of keloid scar has been presented. The variety of methods used to improve pain and aesthetic result demonstrates the propensity of keloid scars to recur and the therapeutic challenges that surgeons have to face in their quest for a satisfactory patient outcome.</p

    Leading order analysis of neutrino induced dimuon events in the CHORUS experiment

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    We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with EÎŒ1,EÎŒ2>5E_{\mu 1},E_{\mu 2} > 5 GeV and Q2>3Q^2 > 3 GeV2^2 collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a value of the ratio of the strange to non-strange sea in the nucleon of Îș=0.33±0.05±0.05\kappa = 0.33 \pm 0.05 \pm 0.05, improving the results obtained in similar analyses by previous experiments.Comment: Submitted to Nuclear Physics

    Associated Charm Production in Neutrino-Nucleus Interactions

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    In this paper a search for associated charm production both in neutral and charged current Îœ\nu-nucleus interactions is presented. The improvement of automatic scanning systems in the {CHORUS} experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130,000 Îœ\nu interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18±\pm0.05. The relative rate of the associated charm cross-section in deep inelastic Îœ\nu interactions, σ(ccˉΜ)/σNCDIS=(3.62−2.42+2.95(stat)±0.54(syst))×10−3\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}= (3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3} has been measured. One event with two charm decays has been observed in charged-current ΜΌ\nu_\mu interactions with an estimated background of 0.18±\pm0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be σ(ccˉΌ−)/σCC<9.69×10−4\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} < 9.69 \times 10^{-4}.Comment: 10 pages, 4 figure
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