158 research outputs found
Advanced Technologies and the Future of Medicine and Surgery
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
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
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
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
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
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
Energy recovery modeling of pressure-retarded osmosis systems with membrane modules compatible with high salinity draw streams
DETEKSI GLUKOSA DALAM URIN ORANGUTAN SUMATERA (PONGO ABELII) MENGGUNAKAN STRIPTEST SEMIKUANTITATIF DI TAMAN HEWAN PEMATANG SIANTAR
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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