158 research outputs found

    Advanced Technologies and the Future of Medicine and Surgery

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    Technology has become a major driver of the future direction of healthcare and surgery. Likewise, the speed of change has accelerated beyond comprehension, with a number of revolutions occurring during a surgeon's career. Being an agent of change or rapidly adapting to change has become the hallmark of the gifted surgeon. The fundamental challenges to a future surgeon are addressed from a technological viewpoint, with emphasis on the impact upon healthcare

    A Jupiter-mass planet around the K0 giant HD 208897

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    For over 10 years, we have carried out a precise radial velocity (RV) survey to find substellar companions around evolved G,K-type stars to extend our knowledge of planet formation and evolution. We performed high precision RV measurements for the giant star HD 208897 using an iodine (I2) absorption cell. The measurements were made at T\"UB\.ITAK National Observatory (TUG, RTT150) and Okayama Astrophysical Observatory (OAO). For the origin of the periodic variation seen in the RV data of the star, we adopted a Keplerian motion caused by an unseen companion. We found that the star hosts a planet with a minimum mass of m2sini=1.40MJ, which is relatively low compared to those of known planets orbiting evolved intermediate-mass stars. The planet is in a nearly circular orbit with a period of P=353 days at about 1 AU distance from the host star. The star is metal rich and located at the early phase of ascent along the red giant branch. The photometric observations of the star at Ankara University Kreiken Observatory (AUKR) and the HIPPARCOS photometry show no sign of variation with periods associated with the RV variation. Neither bisector velocity analysis nor analysis of the Ca II and Halpha lines shows any correlation with the RV measurements

    Astronomical Site Selection for Turkey Using GIS Techniques

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    A site selection of potential observatory locations in Turkey have been carried out by using Multi-Criteria Decision Analysis (MCDA) coupled with Geographical Information Systems (GIS) and satellite imagery which in turn reduced cost and time and increased the accuracy of the final outcome. The layers of cloud cover, digital elevation model, artificial lights, precipitable water vapor, aerosol optical thickness and wind speed were studied in the GIS system. In conclusion of MCDA, the most suitable regions were found to be located in a strip crossing from southwest to northeast including also a diverted region in southeast of Turkey. These regions are thus our prime candidate locations for future on-site testing. In addition to this major outcome, this study has also been applied to locations of major observatories sites. Since no goal is set for \textit{the best}, the results of this study is limited with a list of positions. Therefore, the list has to be further confirmed with on-site tests. A national funding has been awarded to produce a prototype of an on-site test unit (to measure both astronomical and meteorological parameters) which might be used in this list of locations.Comment: 17 pages, 10 figures, accepted by Experimental Astronom

    VW LMi: tightest quadruple system known. Light-time effect and possible secular changes of orbits

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    Tightest known quadruple systems VW LMi consists of contact eclipsing binary with P_12 = 0.477551 days and detached binary with P_34 = 7.93063 days revolving in rather tight, 355.0-days orbit. This paper presents new photometric and spectroscopic observations yielding 69 times of minima and 36 disentangled radial velocities for the component stars. All available radial velocities and minima times are combined to better characterize the orbits and to derive absolute parameters of components. The total mass of the quadruple system was estimated at 4.56 M_sun. The detached, non-eclipsing binary with orbital period P = 7.93 days is found to show apsidal motion with U approximately 80 years. Precession period in this binary, caused by the gravitational perturbation of the contact binary, is estimated to be about 120 years. The wide mutual orbit and orbit of the non-eclipsing pair are found to be close to coplanarity, preventing any changes of the inclination angle of the non-eclipsing orbit and excluding occurrence of the second system of eclipses in future. Possibilities of astrometric solution and direct resolving of the wide, mutual orbit are discussed. Nearby star, HD95606, was found to form loose binary with quadruple system VW LMi.Comment: 4 figures. accepted to MNRAS on July 31, 200

    Physical Parameters of Some Close Binaries: ET Boo, V1123 Tau, V1191 Cyg, V1073 Cyg and V357 Peg

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    With the aim of providing new and up-to-date absolute parameters of some close binary systems, new BVR CCD photometry was carried out at the Ankara University Observatory (AUG) for five eclipsing binaries, ET Boo, V1123 Tau, V1191 Cyg, V1073 Cyg and V357 Peg between April, 2007 and October, 2008. In this paper, we present the orbital solutions for these systems obtained by simultaneous light and radial velocity curve analyses. Extensive orbital solution and absolute parameters for ET Boo system were given for the first time through this study. According to the analyses, ET Boo is a detached binary while the parameters of four remaining systems are consistent with the nature of contact binaries. The evolutionary status of the components of these systems are also discussed by referring to their absolute parameters found in this study.Comment: this accepted paper will be published in New Astronom

    Spectroscopic and Photometric Study of the Contact Binary BO CVn

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    We present the results of the study of the contact binary system BO CVn. We have obtained physical parameters of the components based on combined analysis of new, multi-color light curves and spectroscopic mass ratio. This is the first time the latter has been determined for this object. We derived the contact configuration for the system with a very high filling factor of about 88 percent. We were able to reproduce the observed light curve, namely the flat bottom of the secondary minimum, only if a third light has been added into the list of free parameters. The resulting third light contribution is significant, about 20-24 percent, while the absolute parameters of components are: M1=1.16, M2=0.39, R1=1.62 and R2=1.00 (in solar units). The O-C diagram shows an upward parabola which, under the conservative mass transfer assumption, would correspond to a mass transfer rate of dM/dt = 6.3 \times 10-8M\odot/yr, matter being transferred from the less massive component to the more massive one. No cyclic, short-period variations have been found in the O-C diagram (but longer-term variations remain a possibility)Comment: 16 pages, 5 figures, 5 tables, accepted for publication by New Astronom

    DETEKSI GLUKOSA DALAM URIN ORANGUTAN SUMATERA (PONGO ABELII) MENGGUNAKAN STRIPTEST SEMIKUANTITATIF DI TAMAN HEWAN PEMATANG SIANTAR

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    Penelitian ini bertujuan mengetahui ada tidaknya glukosa dalam uron orangutan sumatera (Pongo abelii) sebagai penunjang diagnosa di Taman Hewan Pematang Siantar, Sumatera Utara. Pengoleksian urin terhadap 4 ekor orangutan sumatera di dalam kandang yang dilakukan pada pagi hari yaitu saat orangutan bangun tidur atau sebelum pemberian pakan orangutan. Pengulangan uji dilakukan 3 kali selama 10 hari pada bulan Januari 2015. Setelah pengoleksian urin kemudian dilakukan pemeriksaan dengan cara mencelupkan stripstest pada 5-10 ml urin selama 30 detik. Analisis data menggunakan metode deskriptif kualitatif dengan hasil bersifat semikuantitatif melalui pembacaan nilai glukosa pada stripstest yang memiliki skala perubahan warna yaitu : negatif, positif 1 (100 mg/dL), positif 2 (250 mg/dL), positif 3 (500 mg/dL), dan positif 4 (1000 mg/dL). Hasil penelitian menunjukkan bahwa dari 4 sampel urin orangutan sumatera tidak terdeteksi adanya glukosa dalam urin
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