Infrared photometry of upper main sequence stars in M39

International Nuclear Information System (INIS)

Manteiga, M.; Martinez-Roger, C.; Morales, C.; Sabau, L.

1991-01-01

Infrared photometry of 19 Main sequence stars in the open cluster M39 is presented. Infrared-infrared and optical-infrared colour-colour and colour-magnitude diagrams are presented and compared with mean intrinsic colours for Population I stars. An interstellar reddening of E(B - V) = 0.01 is obtained by analysis of the colour-colour diagrams. Comparison with a set of theoretical isochrones leads to an age estimate for the cluster between 2.4 and 4.8 x 10 8 years

Infrared photometry of upper main sequence stars in M39

Energy Technology Data Exchange (ETDEWEB)

Manteiga, M.; Martinez-Roger, C. (Instituto de Astrofisica de Canarias, Tenerife, (ES)); Morales, C.; Sabau, L. (Instituto de Tecnica Aeroespacial, Madrid, (ES))

1991-03-01

Infrared photometry of 19 Main sequence stars in the open cluster M39 is presented. Infrared-infrared and optical-infrared colour-colour and colour-magnitude diagrams are presented and compared with mean intrinsic colours for Population I stars. An interstellar reddening of E(B - V) = 0.01 is obtained by analysis of the colour-colour diagrams. Comparison with a set of theoretical isochrones leads to an age estimate for the cluster between 2.4 and 4.8 x 10{sup 8} years.

Star Formation in M 33 (HerM33es)

Science.gov (United States)

Kramer, C.; Boquien, M.; Braine, J.; Buchbender, C.; Calzetti, D.; Gratier, P.; Mookerjea, B.; Relaño, M.; Verley, S.

2011-11-01

Within the key project "Herschel M 33 extended survey" (HerM33es), we are studying the physical and chemical processes driving star formation and galactic evolution in the nearby galaxy M 33, combining the study of local conditions affecting individual star formation with properties only becoming apparent on global scales. Here, we present recent results obtained by the HerM33es team. Combining Spitzer and Herschel data ranging from 3.6 μm to 500μm, along with H i, Hα, and GALEX UV data, we have studied the dust at high spatial resolutions of 150 pc, providing estimators of the total infrared (TIR) brightness and of the star formation rate. While the temperature of the warm dust at high brightness is driven by young massive stars, evolved stellar populations appear to drive the temperature of the cold dust. Plane-parallel models of photon dominated regions (PDRs) fail to reproduce fully the [C ii], [O i], and CO maps obtained in a first spectroscopic study of one 2' × 2' subregion of M 33, located on the inner, northern spiral arm and encompassing the H ii region BCLMP 302.

Düzce Yöresinde Su Kullanımı ve Tabansuyu

Directory of Open Access Journals (Sweden)

Selçuk ÖZMEN

2014-06-01

Full Text Available Bu çalışmada, Düzce yöresinde su kullanımı ve tabansuyu durumu irdelenmiştir. Yörede bulanan toplam tarım arazilerinin % 36’sı sulanmakta olup, bu arazilerde ağırlıklı olarak yüzey sulama yöntemi uygulanmaktadır. Yapılan çalışmalar sonucunda; bu yörede sulama ile ilgili daha önce yapılan çalışmaların yetersiz olduğu ve basınçlı sulama tekniklerinin uygulama oranın sadece % 5-10 aralığında değiştiği saptanmıştır. Bununla birlikte, yörenin değişken topografik yapısı nedeniyle kış ve ilkbahar aylarında taban suyunun arttığı gözlenmiştir. Yörede sulama ve tabansuyu kaynaklı tuzluluk problemi olmadığı belirlenmiştir

Mechanism of mRNA-STAR domain interaction: Molecular dynamics simulations of Mammalian Quaking STAR protein.

Science.gov (United States)

Sharma, Monika; Anirudh, C R

2017-10-03

STAR proteins are evolutionary conserved mRNA-binding proteins that post-transcriptionally regulate gene expression at all stages of RNA metabolism. These proteins possess conserved STAR domain that recognizes identical RNA regulatory elements as YUAAY. Recently reported crystal structures show that STAR domain is composed of N-terminal QUA1, K-homology domain (KH) and C-terminal QUA2, and mRNA binding is mediated by KH-QUA2 domain. Here, we present simulation studies done to investigate binding of mRNA to STAR protein, mammalian Quaking protein (QKI). We carried out conventional MD simulations of STAR domain in presence and absence of mRNA, and studied the impact of mRNA on the stability, dynamics and underlying allosteric mechanism of STAR domain. Our unbiased simulations results show that presence of mRNA stabilizes the overall STAR domain by reducing the structural deviations, correlating the 'within-domain' motions, and maintaining the native contacts information. Absence of mRNA not only influenced the essential modes of motion of STAR domain, but also affected the connectivity of networks within STAR domain. We further explored the dissociation of mRNA from STAR domain using umbrella sampling simulations, and the results suggest that mRNA binding to STAR domain occurs in multi-step: first conformational selection of mRNA backbone conformations, followed by induced fit mechanism as nucleobases interact with STAR domain.

Corium Spreading Over Concrete: The Vulcano VE-U7 and VE-U8 Tests

International Nuclear Information System (INIS)

Journeau, Christophe; Boccaccio, Eric; Fouquart, Pascal; Jegou, Claude; Piluso, Pascal

2002-01-01

Two experiments have been performed in the VULCANO facility in which prototypic corium has been spread over concrete. In the VE-U7 test, a mixture representative of what can be expected at the opening of EPR reactor-pit gate has been spread on siliceous concrete and on a reference channel in inert refractory ceramic. The spreading progression was not much affected by the presence of concrete and sparging gases. In the VE-U8 test, a UO 2 -ZrO 2 mixture, prototypic of in-vessel corium, has been spread over a lime-siliceous concrete. Although residual power was not simulated in this experiment, up to 2 cm of concrete have been eroded during the test. Results in terms of spreading behaviour, effects of gases, concrete erosion and thermal attack are presented and discussed. (authors)

RR Lyrae Stars in M4

Science.gov (United States)

Kuehn, Charles A.; Moskalik, Pawel; Drury, Jason A.

2017-10-01

Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomna, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During campaign 2, K2 observed the globular cluster M4, providiing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. In this poster we present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in both observed RRc stars. In 3 RRab stars we have found the Blazhko effect with periods of 16.6d, 22.4d, and 44.5d.

RR Lyrae Stars in M4

Directory of Open Access Journals (Sweden)

Kuehn Charles A

2017-01-01

Full Text Available Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomna, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During campaign 2, K2 observed the globular cluster M4, providiing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. In this poster we present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in both observed RRc stars. In 3 RRab stars we have found the Blazhko effect with periods of 16.6d, 22.4d, and 44.5d.

A SPECTROSCOPIC SURVEY OF MASSIVE STARS IN M31 AND M33

Energy Technology Data Exchange (ETDEWEB)

Massey, Philip; Neugent, Kathryn F.; Smart, Brianna M., E-mail: phil.massey@lowell.edu, E-mail: kneugent@lowell.edu, E-mail: bsmart@astro.wisc.edu [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

2016-09-01

We describe our spectroscopic follow-up to the Local Group Galaxy Survey (LGGS) photometry of M31 and M33. We have obtained new spectroscopy of 1895 stars, allowing us to classify 1496 of them for the first time. Our study has identified many foreground stars, and established membership for hundreds of early- and mid-type supergiants. We have also found nine new candidate luminous blue variables and a previously unrecognized Wolf–Rayet star. We republish the LGGS M31 and M33 catalogs with improved coordinates, and including spectroscopy from the literature and our new results. The spectroscopy in this paper is responsible for the vast majority of the stellar classifications in these two nearby spiral neighbors. The most luminous (and hence massive) of the stars in our sample are early-type B supergiants, as expected; the more massive O stars are more rare and fainter visually, and thus mostly remain unobserved so far. The majority of the unevolved stars in our sample are in the 20–40 M {sub ⊙} range.

ÜRETİM VE HİZMET İŞLETMELERİ AÇISINDAN YÖNETİM VE ORGANİZASYON YAKLAŞIMLARINA TOPLU BİR BAKIŞ (KLASİK-NEOKLASİK-MODERN-NEOMODERN YAKLAŞIMLAR)

OpenAIRE

Türengül, M.

2018-01-01

Globalleşme ile birlikte yönetim ve organizasyon yaklaşımları uygulamada önem kazanmış olup, işletmeler, belirledikleri stratejilere göre ve piyasa (Pazar) koşullarını da göz önünde bulundurarak en uygun yaklaşıma uygulamada yer vermişlerdir. Klasik yaklaşım, neoklasik yaklaşım, modern yaklaşım özelliklede koşulsallık yaklaşımı neo-modern yaklaşım uygulamada yer almıştır.

Stellar model chromospheres. XIII - M dwarf stars

Science.gov (United States)

Giampapa, M. S.; Worden, S. P.; Linsky, J. L.

1982-01-01

Single-component, homogeneous model chromospheres that are consistent with high-resolution profiles of the Ca II K line calibrated in surface flux units for three dMe and 2 dM stars observed at quiescent times are constructed. The models reveal several systematic trends. Large values of the ratio of T(min) to T(eff) are derived, indicating a large amount of nonradiative heating present in the upper photospheres of M dwarf stars. It is also found that the lower chromospheric temperature gradient is similar for all the M dwarf stars. Since for the models here the chromospheric K line emission strength is most sensitive to the total amount of chromospheric material present within the approximate temperature range T(min)-6000 K, increasing the emission strength is not simply due to increasing chromospheric temperature gradients. It is also found that both the electron density and electron temperature at one thermalization length in the K line below the top of the chromospheres are greater in the dMe stars than in the dM stars. The M dwarf models here have microturbulent velocities between 1 and 2 km/sec, which are much smaller than for solar chromosphere models.

The Nature of VeLLOs

Science.gov (United States)

Huard, Tracy L.; Pound, Marc W.; Mundy, Lee; Dunham, Michael

2018-01-01

Very Low Luminosity Objects (VeLLOs) are young stellar sources that are defined by luminosities less than 0.1 solar luminosity and rising mid-infrared spectral energy distributions. But, what exactly are they? Brown dwarfs or low-mass stars in formation? Systems exhibiting low accretion rates? Extremely young objects? We have completed an ALMA survey of 33 candidates in the nearby Serpens, Ophiuchus, and Lupus star-forming molecular clouds. Continuum emission at 1.3 mm, consistent with the presence of an inner envelope and/or disk, was detected toward 17 candidates, with at least 6 of these candidates exhibiting CO outflow emission, suggesting ongoing formation. We will present these observations and results, and discuss their implications concerning the nature of VeLLOs.

VLA observations of dwarf M flare stars and magnetic stars

Science.gov (United States)

Willson, R. F.; Lang, K. R.; Foster, P.

1988-01-01

The VLA has been used to search for 6 cm emission from 16 nearby dwarf M stars, leading to the detection of only one of them - Gliese 735. The dwarf M flare stars AD Leonis and YZ Canis Minoris were also monitored at 6 cm and 20 cm wavelength in order to study variability. Successive oppositely circularly polarized bursts were detected from AD Leo at 6 cm, suggesting the presence of magnetic fields of both magnetic polarities. An impulsive 20-cm burst from YZ CMi preceded slowly varying 6-cm emission. The VLA was also used, unsuccessfully, to search for 6-cm emission from 13 magnetic Ap stars, all of which exhibit kG magnetic fields. Although the Ap magnetic stars have strong dipolar magnetic fields, the failure to detect gyroresonant radiation suggests that these stars do not have hot, dense coronae. The quiescent microwave emission from GL 735 is probably due to nonthermal radiation, since unusually high (H = 50 kG or greater) surface magnetic fields are inferred under the assumption that the 6-cm radiation is the gyroresonant radiation of thermal electrons.

M-dwarf rapid rotators and the detection of relatively young multiple M-star systems

International Nuclear Information System (INIS)

Rappaport, S.; Joss, M.; Sanchis-Ojeda, R.

2014-01-01

We have searched the Kepler light curves of ∼3900 M-star targets for evidence of periodicities that indicate, by means of the effects of starspots, rapid stellar rotation. Several analysis techniques, including Fourier transforms, inspection of folded light curves, 'sonograms', and phase tracking of individual modulation cycles, were applied in order to distinguish the periodicities due to rapid rotation from those due to stellar pulsations, eclipsing binaries, or transiting planets. We find 178 Kepler M-star targets with rotation periods, P rot , of <2 days, and 110 with P rot < 1 day. Some 30 of the 178 systems exhibit two or more independent short periods within the same Kepler photometric aperture, while several have 3 or more short periods. Adaptive optics imaging and modeling of the Kepler pixel response function for a subset of our sample support the conclusion that the targets with multiple periods are highly likely to be relatively young physical binary, triple, and even quadruple M star systems. We explore in detail the one object with four incommensurate periods all less than 1.2 days, and show that two of the periods arise from one of a close pair of stars, while the other two arise from the second star, which itself is probably a visual binary. If most of these M-star systems with multiple periods turn out to be bound M stars, this could prove a valuable way discovering young hierarchical M-star systems; the same approach may also be applicable to G and K stars. The ∼5% occurrence rate of rapid rotation among the ∼3900 M star targets is consistent with spin evolution models that include an initial contraction phase followed by magnetic braking, wherein a typical M star can spend several hundred Myr before spinning down to periods longer than 2 days.

Activity-induced radial velocity variation of M dwarf stars

DEFF Research Database (Denmark)

Andersen, Jan Marie; Korhonen, Heidi Helena

2012-01-01

that can drown out a planetary signature. Cool, low-mass M dwarf stars can be highly active, which can make detection of potentially habitable planets around these stars difficult. We investigate radial velocity variations caused by different activity (spot) patterns on M dwarf stars in order to determine...... the limits of detectability for small planets orbiting active M dwarfs. We report on our progress toward the aim of answering the following questions: What types of spot patterns are realistic for M dwarf stars? What effect will spots have on M dwarf RV measurements? Can jitter from M dwarf spots mimic...... planetary signals? What is the ideal observing wavelength to reduce M dwarf jitter?...

WASP-12b AND HAT-P-8b are members of triple star systems

Energy Technology Data Exchange (ETDEWEB)

Bechter, Eric B.; Crepp, Justin R.; Matthews, Christopher T. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Johnson, John Asher [Department of Planetary Science, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Hinkley, Sasha; Muirhead, Philip S.; Montet, Benjamin T.; Morton, Timothy D. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Howard, Andrew W., E-mail: ebechter@nd.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

2014-06-10

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M {sub ☉} using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

WASP-12b and HAT-P-8b are Members of Triple Star Systems

Science.gov (United States)

Bechter, Eric B.; Crepp, Justin R.; Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Hinkley, Sasha; Muirhead, Philip S.; Johnson, John Asher; Howard, Andrew W.; Montet, Benjamin T.; Matthews, Christopher T.; Morton, Timothy D.

2014-06-01

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M ⊙ using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

WASP-12b AND HAT-P-8b are members of triple star systems

International Nuclear Information System (INIS)

Bechter, Eric B.; Crepp, Justin R.; Matthews, Christopher T.; Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Johnson, John Asher; Hinkley, Sasha; Muirhead, Philip S.; Montet, Benjamin T.; Morton, Timothy D.; Howard, Andrew W.

2014-01-01

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M ☉ using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

THE CLOSE BINARY FRACTION OF DWARF M STARS

International Nuclear Information System (INIS)

Clark, Benjamin M.; Blake, Cullen H.; Knapp, Gillian R.

2012-01-01

We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template-fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs. Typically, the three or four spectra observed for each star are separated in time by less than four hours, but for ∼17% of the stars, the individual observations span more than two days. In these cases we are sensitive to large-amplitude radial velocity variations on timescales comparable to the separation between the observations. We use a control sample of objects having observations taken within a four-hour period to make an empirical estimate of the underlying radial velocity error distribution and simulate our detection efficiency for a wide range of binary star systems. We find the frequency of binaries among the dwarf M stars with a < 0.4 AU to be 3%-4%. Comparison with other samples of binary stars demonstrates that the close binary fraction, like the total binary fraction, is an increasing function of primary mass.

THE CLOSE BINARY FRACTION OF DWARF M STARS

Energy Technology Data Exchange (ETDEWEB)

Clark, Benjamin M. [Penn Manor High School, 100 East Cottage Avenue, Millersville, PA 17551 (United States); Blake, Cullen H.; Knapp, Gillian R. [Princeton University, Department of Astrophysical Sciences, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)

2012-01-10

We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template-fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs. Typically, the three or four spectra observed for each star are separated in time by less than four hours, but for {approx}17% of the stars, the individual observations span more than two days. In these cases we are sensitive to large-amplitude radial velocity variations on timescales comparable to the separation between the observations. We use a control sample of objects having observations taken within a four-hour period to make an empirical estimate of the underlying radial velocity error distribution and simulate our detection efficiency for a wide range of binary star systems. We find the frequency of binaries among the dwarf M stars with a < 0.4 AU to be 3%-4%. Comparison with other samples of binary stars demonstrates that the close binary fraction, like the total binary fraction, is an increasing function of primary mass.

Türkiye’de Yemeklik Tane Baklagiller Üretiminin Sorunları ve Çözüm Önerileri

Directory of Open Access Journals (Sweden)

Aybegün Ton

2014-05-01

Full Text Available Türkiye’de yemeklik tane baklagiller içerisinde ekim alanı ve üretim bakımından ilk sırayı nohut almakta, bunu sırasıyla mercimek, fasulye ve bakla izlemektedir. Türkiye, özellikle nohut ve mercimekte Dünyada en önemli üretici ve ihracatçı ülkeler içerisinde bulunmaktadır. Son yıllarda ise nohut ve mercimek üretimimiz ve ihracatımız bir azalma eğilimi içerisinde bulunmaktadır. Bununla birlikte, birçok yemeklik tane baklagil türlerinin üretimine uygun farklı ekolojik koşulları içeren bölgelerimiz bulunmaktadır. Bu üretim potansiyelimiz değerlendirilmeli, dış pazarların istekleri doğrultusunda, standart irilikte, kaliteli ve yüksek verim potansiyeline sahip çeşitlerimizin üretimine önem verilmelidir. Ayrıca, uygun yetiştirme teknikleri kullanılarak üretim yapılmalı, kıyı bölgelerimizde kışlık nohut yetiştiriciliği, iç bölgelerimizde kışlık mercimek yetiştiriciliği yaygınlaştırılmalı, ekimde ve hasat da makine kullanımına önem verilmeli, hastalık ve zararlılarla yeterli düzeyde mücadele edilerek verimlilik artırılmalıdır. Böylece, Türkiye’de yemeklik tane baklagiller tarımının bugünkünden çok daha fazla yaygınlaştırılması mümkün görülmektedir.

E-Book Technology and Its Use E-Kitap Teknolojisi ve Kullanımı

Directory of Open Access Journals (Sweden)

Fatih Rukancı

2003-06-01

Full Text Available The book industry that showed extraordinary development with the invention of printing machine by Johann Gutenberg during the 1450's is constantly changing along with new telecommunication and information technologies. The most recent evolution in the book and publishing industry is electronic books. E-book technology supported by hardware, software and standart protocols and some of its advantage and disadvantages had produced e-book readers that became unseparable part of our academic and daily life. E-books, in recent years, has became more widespread in the areas of publishing, education and information services and are reaching larger user groups. It is expected that this new technology will change our way of information acquisition and dissemination. This seems unavoidable despite the views of those who argue that e-books cannot be an alternative to printed books. Widespread of e-books will be added a new dimension to technical and user services in information centers. 1450'li yıllarda Johann Gutenberg'in matbca makinesini icat etmesiyle oldukça büyük bir gelişim gösteren kitap endüstrisi, iletişim ve bilgi teknolojilerine paralel olarak sürekli bir değişim içindedir. Bu değişimin son halkasını kitap endüstrisinde ve yayıncılık sektöründe devrimsel bir nitelik taşıyan elektronik kitaplar oluşturmaktadır. Yazılım, donanım, standart ve protokol bileşenlerinden oluşan e-kitap teknolojisi, bir takım avantaj ve dezavantajlarıyla beraber birçok yeni ekitap okuma cihazının akademik ve gündelik yaşantımıza girmesine neden olmuştur. E-kitaplar, günümüzde yayıncılık, eğitim ve bilgi hizmetleri alanlarında gelişme göstermekte, gün geçtikçe artan sayılarıyla daha geniş kullanıcı kitlelerine hitap etmektedir. Basılı kitaplara alternatif olabileceği tartışılmakta olan bu teknolojinin zamanla bilgi edinme ve bilgiyi yayma yöntemlerimizi değiştirmesi kaçınılmazdır. E-kitapların yayg

Systemic effects in naïve mice injected with immunomodulatory lectin ArtinM.

Directory of Open Access Journals (Sweden)

Patrícia Kellen Martins Oliveira Brito

Full Text Available Toll-like receptors (TLR contain N-glycans, which are important glycotargets for plant lectins, to induce immunomodulation. The lectin ArtinM obtained from Artocarpus heterophyllus interacts with TLR2 N-glycans to stimulate IL-12 production by antigen-presenting cells and to drive the immune response toward the Th1 axis, conferring resistance against intracellular pathogens. This immunomodulatory effect was demonstrated by subcutaneously injecting (s.c. ArtinM (0.5 μg in infected mice. In this study, we evaluated the systemic implications of ArtinM administration in naïve BALB/c mice. The mice were s.c. injected twice (7 days interval with ArtinM (0.5, 1.0, 2.5, or 5.0 μg, LPS (positive control, or PBS (negative control and euthanized after three days. None of the ArtinM-injected mice exhibited change in body weight, whereas the relative mass of the heart and lungs diminished in mice injected with the highest ArtinM dose (5.0 μg. Few and discrete inflammatory foci were detected in the heart, lung, and liver of mice receiving ArtinM at doses ≥2.5 μg. Moreover, the highest dose of ArtinM was associated with increased serum levels of creatine kinase MB isoenzyme (CK-MB and globulins as well as an augmented presence of neutrophils in the heart and lung. IL-12, IFN-γ, TNF-α, and IL-10 measurements in the liver, kidney, spleen, heart, and lung homogenates revealed decreased IL-10 level in the heart and lung of mice injected with 5.0 μg ArtinM. We also found an augmented frequency of T helper and B cells in the spleen of all ArtinM-injected naïve mice, whereas the relative expressions of T-bet, GATA-3, and ROR-γt were similar to those in PBS-injected animals. Our study demonstrates that s.c. injection of high doses of ArtinM in naïve mice promotes mild inflammatory lesions and that a low immunomodulatory dose is innocuous to naïve mice.

Systemic effects in naïve mice injected with immunomodulatory lectin ArtinM

Science.gov (United States)

Oliveira Brito, Patrícia Kellen Martins; Gonçalves, Thiago Eleutério; Fernandes, Fabrício Freitas; Miguel, Camila Botelho; Rodrigues, Wellington Francisco; Lazo Chica, Javier Emílio; Roque-Barreira, Maria Cristina

2017-01-01

Toll-like receptors (TLR) contain N-glycans, which are important glycotargets for plant lectins, to induce immunomodulation. The lectin ArtinM obtained from Artocarpus heterophyllus interacts with TLR2 N-glycans to stimulate IL-12 production by antigen-presenting cells and to drive the immune response toward the Th1 axis, conferring resistance against intracellular pathogens. This immunomodulatory effect was demonstrated by subcutaneously injecting (s.c.) ArtinM (0.5 μg) in infected mice. In this study, we evaluated the systemic implications of ArtinM administration in naïve BALB/c mice. The mice were s.c. injected twice (7 days interval) with ArtinM (0.5, 1.0, 2.5, or 5.0 μg), LPS (positive control), or PBS (negative control) and euthanized after three days. None of the ArtinM-injected mice exhibited change in body weight, whereas the relative mass of the heart and lungs diminished in mice injected with the highest ArtinM dose (5.0 μg). Few and discrete inflammatory foci were detected in the heart, lung, and liver of mice receiving ArtinM at doses ≥2.5 μg. Moreover, the highest dose of ArtinM was associated with increased serum levels of creatine kinase MB isoenzyme (CK-MB) and globulins as well as an augmented presence of neutrophils in the heart and lung. IL-12, IFN-γ, TNF-α, and IL-10 measurements in the liver, kidney, spleen, heart, and lung homogenates revealed decreased IL-10 level in the heart and lung of mice injected with 5.0 μg ArtinM. We also found an augmented frequency of T helper and B cells in the spleen of all ArtinM-injected naïve mice, whereas the relative expressions of T-bet, GATA-3, and ROR-γt were similar to those in PBS-injected animals. Our study demonstrates that s.c. injection of high doses of ArtinM in naïve mice promotes mild inflammatory lesions and that a low immunomodulatory dose is innocuous to naïve mice. PMID:29084277

Sazan (Cyprinus carpio Balığı Gastrointestinal Kanal Mukozasındaki CCK-8, Gastrin 1, VIP, Sekretin, Somatostatin-14, Bombesin ve Histamin Peptidlerinin Lokalizasyonu.

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Nurgül Şenol

2015-12-01

Full Text Available Bu çalışmada; Cyprinus carpio (sazan gastrointestinal kanal mukozasının kolesistokinin-8, gastrin 1, vasoaktif intesinal polypeptid, sekretin, somatostatin-14, bombesin ve histamin peptidlerinin lokalizasyon ve dağılımlarının belirlenmesi amaçlanmıştır. Yapılan immunohistokimyasal çalışmalar sonucunda sazan (Cyprinus carpio’ın mide (sazanda genişlemiş ön bağırsak bölgesi ve bağırsak bölümlerinde (ilk, orta ve son bağırsak genel olarak çalışılan tüm peptidlerin farklı yoğunlukta lokalize oldukları tespit edildi

Mikrodenetleyici Denetimli Televizyon Deney Seti Tasarımı ve Gerçekleştirilmesi

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Serdar ÇİÇEK

2009-03-01

Full Text Available Bu çalışmada, teknik ve mesleki eğitim veren fakülteler, yüksekokullar, endüstri meslek liseleri, çıraklık ve yaygın eğitim merkezleri, meslek kursu veren belediyeler ve özel eğitim merkezleri vb. kurumlardaki görüntü sistemleri, televizyon tekniği, televizyon teknik servisliği gibi televizyon sisteminin ve televizyon arıza-onarım-bakım konularının işlendiği derslerde, derslerin pratik uygulama kısmında kullanılmak üzere bir televizyon deney seti tasarlanmış ve gerçekleştirilmiştir. Bu deney seti ile öğrenciler/ kursiyerler derste edindiği teorik bilgiler ışığında televizyon sistemlerini daha iyi kavrayabilecek, televizyon arızalarını bulma becerisini uygulamalı olarak geliştirebilecektir. Deney setine ek olarak televizyon ile bağlantılı bir ölçüm panosu da gerçekleştirilmiştir. Böylece televizyon üzerinde istenen ölçümler rahatça yapılabilmektedir. Geliştirilen deney setinde, kullanıcının birden fazla hatayı aynı anda gerçekleştirerek hata bulma adımlarını geliştirmesi mümkündür.

Ages of M Dwarf Stars from their Alpha Enhancement

Science.gov (United States)

Muirhead, Philip Steven; Veyette, Mark

2018-01-01

M dwarf stars dominate stellar populations, and recent results from NASA's Kepler Mission suggest rocky planets are abundant around M dwarf stars. With so many planets orbiting M dwarfs, exoplanet scientists can now turn to questions about their history and evolution. Unfortunately, measuring fundamental properties of M dwarfs is challenging for a variety of reasons. I will discuss the importance of near-infrared spectroscopy in this effort. With high-resolution near-infrared spectroscopy covering Y to K band, we can measure detailed fundamental properties of low-mass stars. With new techniques to measure stellar alpha and iron abundances, we can begin to measure the most challenging fundamental property of M dwarfs: their age. These efforts are even more exciting in the coming years, when the TESS spacecraft is expected to discover five times as many planets orbiting low-mass stars as Kepler.

Abundance Survey of M and K Dwarf Stars

Energy Technology Data Exchange (ETDEWEB)

Woolf, Vincent M. [Astronomy Department, University of Washington, Seattle, WA 98133 (United States); Wallerstein, George [Astronomy Department, University of Washington, Seattle, WA 98133 (United States)

2005-07-25

We report the measurement of chemical abundances in 35 low-mass main sequence (M and K dwarf) stars. We have measured the abundance of 12 elements in Kapteyn's Star, a nearby halo M subdwarf. The abundances indicate an iron abundance of [Fe/H] = -0.98, which is about 0.5 dex smaller than that measured in the only previous published measurement using atomic absorption lines. We have measured Fe and Ti abundances in 35 M and K dwarfs with -2.39 [Fe/H] +0.21 using atomic absorption lines, mostly in the 8000A <{lambda} < 8850A range. These will be used to calibrate photometric and low-resolution spectrum metallicity indices for low mass dwarfs, which will make metallicity estimates for these stars more certain. We also describe some difficulties encountered which are not normally necessary to consider when studying warmer stars.

Podnikatelský záměr ve venkovském cestovním ruchu

OpenAIRE

Kohoutová, Ivana

2014-01-01

Diplomová práce se zabývá vypracováním podnikatelského záměru ve venkovském cestovním ruchu pro založení rodinného podniku. Tento podnik spojuje poskytování služeb v rámci rodinného venkovského penzionu s vlastní zemědělskou výrobou. Cílem práce je na základě provedených analýz, plánů a zhodnocení rizik, navrhnout podnikatelský plán sloužící jako nástroj pro rozhodování o jeho budoucí realizaci. The master's thesis deals with drawing up a rural tourism business plan for the establishment o...

The first detection on Wolf-Rayet stars in M31

International Nuclear Information System (INIS)

Shara, M.M.; Moffat, A.F.J.

1982-01-01

A search to continuum magnitude B approximately equal to 21.5 (Msub(B) approximately equal to -3) using a narrow band filter at lambda4670A and a wide B-band filter has revealed 21 Wolf-Rayet star candidates in about half the giant Sb galaxy M31. Some weak-line WR stars, particularly WN subtypes, may have escaped detection. These numbers are compatible with the total number of luminous (i.e. massive) stars in M31. Eighteen of twenty confirmed candidate stars in M31 lie in the direction of OB associations in the ring of prominent star formation 5-16 kpc from the center. (Auth.)

On the spatial distribution of the M spectral type stars

International Nuclear Information System (INIS)

Kevanishvili, G.T.

1982-01-01

The distribution of M stars with known radial velocities is studied on the base of the Wilson catalogue data. M stars have turned out to show a trend to clustering. The analysis of distances between these grouping stars as well as of their radial velocities, proper motions and other physical characteristics has allowed to keep 24 such groupings. Data concerning the grouping configurations and different physical characteristics of group stars are given. The stars belonging to one group are mostly giants. As a rule each grouping has one or two emission stars, but sometimes all the stars of a grouping are emission ones. It is possible that these groupings are the physical ones and the stars contained in them are of a common origin

Üzüm Çekirdeği Tozu ve Peynir Altı Suyu Tozunun Tavuk Nugget Kalitesi Üzerine Etkileri

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Ece Cagdas

2015-02-01

Full Text Available Bu çalışma kapsamında; buğday unu, mısır unu, tuz ve kabartma ajanı ile hazırlanan basit kaplama hamuruna değişik oranlarda üzüm çekirdeği tozu (GSP eklenerek kaplanan ve peynir altı suyu tozu çözeltisine (WPS daldırılarak kaplanan tavuk eti parçalarının ön kızartma işleminden sonra nem, protein, yağ ve yüzeyde yapışma miktarları belirlenmiştir. Bunların yanı sıra, doku, taramalı elektron mikroskobu (SEM ve tiyobarbitürik asit (TBA analizleri yapılmıştır. Yapılan çalışma sonucunda GSP miktarı arttıkça nem (%66.20±0.71 – 68.22±0.38, protein (%16.16±1.36 – 19.73±1.40 ve yüzeyde yapışma miktarı (%26.27±0.43 – 36.13±0.71 artış gösterirken yağ miktarında (%8.18±0.17 – 4.78±0.54 azalış meydana gelmiştir. En düşük yağ miktarları WPS’ye daldırılarak hazırlanan örneklerde bulunmuştur. Uygulama yapılan örneklerde ön kızartma işleminden sonra da antioksidan aktivite gözlenmiş ve uygulama yapılan tüm örneklerin TBA değerleri (23.30±1.61 – 27.17±1.12 mg MDA/kg kontrol ile karşılaştırıldığında daha düşük seviyelerde olsa da önemli bir fark belirlenmemiştir (P>0.05. Elde edilen sonuçlara göre kaplama harcı malzemesi olarak GSP kullanımı ve WPS’ye daldırma işlemi kaplama harcının kalitesinin geliştirilmesinde bir potansiyele sahiptir.

İnteraktif ve Web Tabanlı Genetik Algoritma Eğitim Yazılımı

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Ali Hakan IŞIK

2017-04-01

Full Text Available Genetik algoritma optimizasyon problemlerinin çözümünde sıklıkla tercih edilen yapay zeka algoritmalarından biridir. Doğadaki canlıların evrimsel sürecinden esinlenerek geliştirilen genetik algoritma, karmaşık yapısından dolayı anlaşılması zor bir çalışma mekanizmasına sahiptir. Bu zorluğun üstesinden gelebilmek için genetik algoritmanın öğretilmesini destekleyici yazılımlar geliştirilmesi büyük öneme sahiptir. Bu çalışmada, genetik algoritma temellerinin ve çalışma prensiplerinin etkileşimli ve kolay bir şekilde öğretilmesi amacıyla interaktif ve web tabanlı genetik algoritma eğitim yazılımı geliştirilmiştir. Yazılımın ASP.NET MVC platformunda uyumlu (responsive yapıda olması ile literatürde ilk defa farklı tarayıcı boyutlarına sahip masaüstü, dizüstü, tablet ve cep telefonlarından yazılıma erişebilmesi ve kullanılabilmesi sağlanmıştır. Yazılımın sahip olduğu ders içerikleri, uygulamalar ve genetik algoritma arayüzler sayesinde etkili ve verimli bir öğrenme gerçekleşmesine katkı sağlanmıştır. Çalışmada, hiçbir kodlama bilgisi gerekmeden genetik algoritma parametreleri gerçek zamanlı olarak değiştirilebilmekte ve sonuçlar grafiksel çıktılar ile gözlenebilmektedir. Böylece genetik algoritma çalışma mekanizmasının kolay bir şekilde öğrenilmesine olanak sağlanmaktadır. Literatürdeki diğer çalışmalar ile karşılaştırıldığında sunulan çalışma, kolaylık, erişilebilirlik ve görsellik özellikleri ile de yenilik getirmektedir.

Fotometría infrarroja del Reloj de Arena en M8

Science.gov (United States)

Arias, J.; Barbá, R.; Morrell, N.; Rubio, M.

We present sub-arcsecond resolution JHKs imaging of the Hourglass Nebula in Messier 8, obtained with the 2.5-m du Pont telescope at Las Campanas Observatory (LCO), Chile. Near-infrared colors have been measured for numerous infrared sources around the O-type star Herschel 36 (O7 V), the brightest source in the field and main responsible for the nebula ionization. Several of those IR sources are identified as Hα emission stars from narrow-band Hubble Space Telescope images, and some of them display a knotty shape, characteristic of proplyd-like objects. Based on the NIR color-color and color-magnitude diagrams, we also identified dozens of NIR excess sources which %we selected as are prime candidates to be intermediate and low-mass pre-main-sequence stars. Additionally, we present preliminary results of the spectroscopic confirmation of some T Tauri stars among these objects, based on spectra recently obtained with the 6.5-m Magellan telescope at LCO.

8 Meter Advanced Technology Large-Aperture Space Telescope (ATLAST-8m)

Science.gov (United States)

Stahl, H. Philip

2010-01-01

ATLAST-8m (Advanced Technology Large Aperture Space Telescope) is a proposed 8-meter monolithic UV/optical/NIR space observatory (wavelength range 110 to 2500 nm) to be placed in orbit at Sun-Earth L2 by NASA's planned Ares V heavy lift vehicle. Given its very high angular resolution (15 mas @ 500 nm), sensitivity and performance stability, ATLAST-8m is capable of achieving breakthroughs in a broad range of astrophysics including: Is there life elsewhere in the Galaxy? An 8-meter UVOIR observatory has the performance required to detect habitability (H2O, atmospheric column density) and biosignatures (O2, O3, CH4) in terrestrial exoplanet atmospheres, to reveal the underlying physics that drives star formation, and to trace the complex interactions between dark matter, galaxies, and intergalactic medium. The ATLAST Astrophysics Strategic Mission Concept Study developed a detailed point design for an 8-m monolithic observatory including optical design; structural design/analysis including primary mirror support structure, sun shade and secondary mirror support structure; thermal analysis; spacecraft including structure, propulsion, GN&C, avionics, power systems and reaction wheels; mass and power budgets; and system cost. The results of which were submitted by invitation to NRC's 2010 Astronomy & Astrophysics Decadal Survey.

A heating mechanism for the chromospheres of M dwarf stars

Science.gov (United States)

Giampapa, M. S.; Golub, L.; Rosner, R.; Vaiana, G.; Linsky, J. L.; Worden, S. P.

1981-01-01

The atmospheric structure of the dwarf M-stars which is especially important to the general field of stellar chromospheres and coronae was investigated. The M-dwarf stars constitute a class of objects for which the discrepancy between the predictions of the acoustic wave chromospheric/coronal heating hypothesis and the observations is most vivid. It is assumed that they represent a class of stars where alternative atmospheric heating mechanisms, presumably magnetically related, are most clearly manifested. Ascertainment of the validity of a hypothesis to account for the origin of the chromospheric and transition region line emission in M-dwarf stars is proposed.

The Star Formation History in the M31 Bulge

Science.gov (United States)

Dong, Hui; Olsen, Knut; Lauer, Tod; Saha, Abhijit; Li, Zhiyuan; García-Benito, Ruben; Schödel, Rainer

2018-05-01

We present the study of stellar populations in the central 5.5' (˜1.2 kpc) of the M31 bulge by using the optical color magnitude diagram derived from HST ACS WFC/HRC observations. In order to enhance image quality and then obtain deeper photometry, we construct Nyquist-sampled images and use a deconvolution method to detect sources and measure their photometry. We demonstrate that our method performs better than DOLPHOT in the extremely crowded region. The resolved stars in the M31 bulge have been divided into nine annuli and the color magnitude diagram fitting is performed for each of them. We confirm that the majority of stars (>70%) in the M31 bulge are indeed very old (> 5 Gyr) and metal-rich ([Fe/H]˜0.3). At later times, the star formation rate decreased and then experienced a significant rise around 1 Gyr ago, which pervaded the entire M31 bulge. After that, stars formed at less than 500 Myr ago in the central 130" . Through simulation, we find that these intermediate-age stars cannot be the artifacts introduced by the blending effect. Our results suggest that although the majority of the M31 bulge are very old, the secular evolutionary process still continuously builds up the M31 bulge slowly. We compare our star formation history with an older analysis derived from the spectral energy distribution fitting, which suggests that the latter one is still a reasonable tool for the study of stellar populations in remote galaxies.

Uygulamalı Bilimler ve Mühendislik

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Recep BAKIŞ

2012-06-01

Full Text Available Türkiye’de enerji ihtiyacı, ülkenin öz kaynaklarından karşılanamadığı için yurt dışından ithal edilmektedir. Oysa Türkiye’nin zengin yenilenebilir su kaynakları vardır. Bu makalede, Nehil Çayının (Zap suyu alt havzası sahip olduğu hidroelektrik enerji potansiyeli, bu kaynağın efektif kullanımına ve böylece ülkenin enerji açığını kısmen kapatmaya yönelik olarak araştırılmıştır. Araştırma, Coğrafi Bilgi Sistemleri (GIS ve Uzaktan Algılama metotları kullanılarak yapılmıştır. Ön araştırmaya göre, Nehil Çayı havzasında bir adet barajın planlaması yapılmış ve bu barajın olası maliyetleri ve buradan temin edilebilecek yıllık elektrik enerjisi miktarı hesaplanmıştır. Barajın toplam maliyetleri ve kurulu gücü Simahpp yazılımı ile hesaplanmıştır. Simahpp yazılımına göre, Nehil Çayı havzasında planlanan barajın toplam maliyeti ve kurulu gücü, 41,3x106 US$ ve 25,2 MW olarak elde edilmiştir. Yılda üretebileceği elektrik enerjisi miktarı ise 39,8 GWh olarak belirlenmiştir

8. Sınıf İnkılâp Tarihi ve Atatürkçülük Dersinde Gazete Kullanımının Öğrencilerin Bu Derse İlişkin Tutum ve Başarısı’na Etkisi The Use Of Newspaper In 8th Grade Revolution And Kemalism Courses And Its Effects On Students Attitude And Success

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Zafer TANGÜLÜ

2013-07-01

Full Text Available In this study use of newspaper at teaching of History of Revolutions and Kemalism subjects and effect of it student achievement and attitude has been presented. The research was conducted on 8th grade students in Ankara in 2011-2012 school year. In the study control grouped pre-test post-test model which is one of the experimental methods has been employed. In the study, subject of “Turkey After Atatürk: World War II and afterward” which is 8th grade 7th unit of the course History of Revolutions and Kemalism has been taught with the use of newspaper clippings in the experimental group, while traditional instructional methods implemented in the control group. Achievement test has been conducted as pre-test and post-test in both experimental and control groups. It has been observed that at the end of 4 week period that historical newspapers used at the course of Revolution History of Republic of Turkey and Kemalism, students in experimental and control groups developed positive attitudes about the course and implementation of the achievement test has demonstrated that achievements increased in favor of the experimental group. At the end of the study various suggestions are made regarding providing in service training for teachers, preparation and free distribution of materials for in class use of teachers, and providing pre-service teachers with necessary skills and knowledge during their undergraduate education to use newspapers in their instructions. Bu çalışmada İnkılâp Tarihi ve Atatürkçülük konularının öğretiminde gazete kullanımının, öğrencilerin bu derse ilişkin tutum ve başarısına etkisi ortaya konulmaya çalışılmıştır. Araştırma 2011-2012 öğretim yılı bahar döneminde Ankara „da 8. Sınıf öğrencileri üzerinde gerçekleştirilmiştir. Araştırrma da deneysel yöntemlerden kontrol gruplu ön-test ve sontest modeli uygulanmıştır. Araştırma da 8. sınıf İnkılâp Tarihi ve Atat

İRAN VE REJİM İSTİKRARI

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Özgür ÜŞENMEZ

2015-07-01

Full Text Available ÖZ: Bu çalışma, İran rejiminin son yıllarda Orta Doğu'yu sarsan isyanlar ve istikrarsızlıklara-Batı'daki beklentilerin aksine- geçmişten, özellikle 1979'daki devrimden miras kalan sosyal yapı ve politikaların etkisiyle direnebildiğini iddia ediyor. Tunus ve Mısır'daki halk isyanları, temel aktör olan alt sınıflar ve onların neo-liberal ekonomik politikalara muhalefetiyle yayılırken, İran’da devrim sonrası gelişen sosyal devlet mekanizması hala halk ile rejimin tamamen birbirine yabancılaşmasını önlemekte. Ancak son yıllarda ortaya çıkan yeni gerilimler ve İran'ın uyguladığı ekonomi politikaları rejimin krizini derinleştirebilir. Bu nedenledir ki Orta Doğu'yu ve özelde İran'ı anlamak için hegemonik blokların tarihsel değişimini inceleyen ucu açık bir analiz elzemdir. ABSTRACT: This article argues that contrary to the expectations of the Western World, Iranian regime successfully resisted the revolutionary tides of the Arab Spring. Most important determinant of this process for Iran was the legacy of the 1979 revolution and it's associated structures that relatively protects the most vulnerable parts of the population against the wide spread neo-liberal economic policies in the Middle East. So with that feature Iran differs from the Tunisian and the Egyptian examples. In order to understand these features further this essay adapts a historical analysis of changes in hegemonic blocs in Iran since 1979.

The habitability of planets orbiting M-dwarf stars

Science.gov (United States)

Shields, Aomawa L.; Ballard, Sarah; Johnson, John Asher

2016-12-01

The prospects for the habitability of M-dwarf planets have long been debated, due to key differences between the unique stellar and planetary environments around these low-mass stars, as compared to hotter, more luminous Sun-like stars. Over the past decade, significant progress has been made by both space- and ground-based observatories to measure the likelihood of small planets to orbit in the habitable zones of M-dwarf stars. We now know that most M dwarfs are hosts to closely-packed planetary systems characterized by a paucity of Jupiter-mass planets and the presence of multiple rocky planets, with roughly a third of these rocky M-dwarf planets orbiting within the habitable zone, where they have the potential to support liquid water on their surfaces. Theoretical studies have also quantified the effect on climate and habitability of the interaction between the spectral energy distribution of M-dwarf stars and the atmospheres and surfaces of their planets. These and other recent results fill in knowledge gaps that existed at the time of the previous overview papers published nearly a decade ago by Tarter et al. (2007) and Scalo et al. (2007). In this review we provide a comprehensive picture of the current knowledge of M-dwarf planet occurrence and habitability based on work done in this area over the past decade, and summarize future directions planned in this quickly evolving field.

M Stars in the TW Hydra Association: A Chandra Large Program Survey

Science.gov (United States)

Punzi, Kristina; Kastner, Joel; Principe, David; Stelzer, Beate; Gorti, Uma; Pascucci, Illaria; Argiroffi, Costanza

2018-01-01

We have conducted a Cycle 18 Chandra Large Program survey of very cool members of the $\\sim$ 8 Myr-old TW Hydra Association (TWA) to extend our previous study of the potential connections between M star disks and X-rays (Kastner et al. 2016, AJ, 152, 3) to the extreme low-mass end of the stellar initial mass function. The spectral types of our targets extend down to the M/L borderline. Thus we can further investigate the potential connection between the intense X-ray emission from young, low-mass stars and the lifetimes of their circumstellar planet-forming discs, as well as better constrain the age at which coronal activity declines for stellar masses approaching the H-burning limit of $\\sim$ 0.08 M$_{\\odot}$. We present preliminary results from the Cycle 18 survey, including X-ray detection statistics and measurements of relative X-ray luminosities and coronal (X-ray) temperatures for those TWA stars detected by Chandra. This research is supported by SAO/CXC grant GO7-18002A and NASA Astrophysics Data Analysis program grants NNX12AH37G and NNX16AG13G to RIT.

Yeni Ürün Geliştirme Takımlarında Güven ve Takım Öğrenmesi

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Volkan POLAT

2018-01-01

Full Text Available Farklı örgütsel seviyelerde güven ve öğrenme üzerine yapılan çalışmaların yanı sıra, güvenin takım bağlamında bilgi paylaşımı ve edinimi için önemli bir faktör olduğunu bildiren birtakım çalışmalar bulunmaktadır. Ancak bugüne kadar yeni ürün geliştirme takımlarında (new product development – NPD Takım Güveni ve Takım Öğrenmesi ilişkileri hakkında çok az tartışma yapılmıştır. Bu çalışma, Takım Güveninin, çeşitli takım faktörleri (Takım Üyesi Deneyimi, Takım İstikrarı ve Takım Otonomisi ve Takım Öğrenimi arasında arabuluculuk etkisi olup olmadığını incelemeyi amaçlamaktadır.

ERZURUM ŞARTLARINDA DİKİM ZAMANI VE TEPE ALMANIN PATATESTE VERİM VE ÇEŞİTLİ ÖZELLİKLERİNE ETKİSİ /

OpenAIRE

Şenol, Sabahattin

2010-01-01

ÖZETErzurum Ekolojik şartlarında dikim ve tepe alma zamanmm patatesteverime ve diğer bazı agronomik karekterlere etkisini tesbitetmek için bu çalışma yapılmış, erkenci ve geç olgunlaşan 34/962 ve49/962 çeşitler bu denemeye alınmıştır. Neticede, en fazıa verim enerken dikim zamanı olarak tayin ediıen 13 Mayıs tarihinde a.ltlnmış,tepe aımanm· veya sürgün öıdürmenin önemli etkisi g&ou...

An unusual microwave flare with 56 second oscillations on the M dwarf L726-8 A

Science.gov (United States)

Gary, D. E.; Dulk, G. A.; Linsky, J. L.

1982-01-01

Using the VLA, an unusual flare event has been observed on L726-8 A (dM5.5e), the primary star in the M dwarf system containing the prototype flare star UV Cet. This flare had a peak flux of 8 mJy at 6 cm and a corresponding brightness temperature greater than 10 to the 10th K, was almost entirely right-hand circularly polarized, showed large flux variations on the 10 s time resolution of the VLA, and exhibited quasi-periodic oscillations with a period of about 56 + or - 5 s. While periodic flux variations have been detected during solar flares and RS CVn type stellar flares, this is apparently the first detection of periodicity in microwaves from M dwarf stars. It is proposed that the observed radiation was due to maser action, probably an electron maser, and that the energy release mechanism was modulated.

Esnek ve Rijit Yol Üst Yapılarında Gürültü Seviyelerinin Eş Zamanlı Ölçümü ve Analizi

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Hakan Yıldırım

2014-06-01

Full Text Available Beton yollar dünyada yaygın olarak kullanılmasına karşın ülkemizde gelişim gösterememiş, bu nedenle de genel olarak bitümlü sıcak karışım asfalt yollar tercih edilmiştir.Bu çalışmada, Türkiye'de yaygın olarak kullanılan bitümlü sıcak karışım asfalt yollar ve henüz yaygınlaşmamış olan beton yollar arasında gürültü seviyeleri yönünden bir karşılaştırma yapılmıştır. Bunun için Afyonkarahisar-Emirdağ arasında inşa edilmiş 2 km'lik beton yol ile bu yolun devamı olan bitümlü sıcak karışım asfalt yol arasındaki geçiş noktası çalışma koridoru olarak kullanılmıştır.Bu koridordaki beton yol ve bitümlü sıcak karışım asfalt yolun kenarlarına, ses girişimlerini en aza indirecek şekilde, ayrı ayrı gürültü ölçüm cihazı ve kamera düzenekleri yerleştirilmiş, yol yapım malzemesine bağlı olarak değişen gürültü seviyeleri eş zamanlı olarak kaydedilmiş, bulunan değerler analiz edilerek kaplama türleri ile gürültü seviyeleri arasındaki ilişki araştırılmıştır. Bu aşamada, kurulan düzenekler arasındaki mesafe trafik yoğunluğunun ve akış hızının değişimini engellemek için mümkün olduğunca kısa tutulmuştur.Yapılan ölçüm ve analizler sonunda beton yolların bitümlü sıcak karışım asfalt yollara göre ortalama gürültü seviyesinin aynı taşıt kompozisyonu ve trafik hacmi için yaklaşık 4 dB(A daha düşük olduğu ortaya konmuş ve ülkemizde de beton yolların gelişim göstermesi gerektiği vurgulanmıştır.

Bibliometric Analysis of Journal Usage Data and Its Use in Collection Management Dergi Kullanım Verilerinin Bibliyometrik Analizi ve Koleksiyon Yönetiminde Kullanımı

Directory of Open Access Journals (Sweden)

Yaşar Tonta

2008-09-01

Full Text Available The use of a library’s collection should be monitored and the results should be taken into consideration in order to establish an effective and effi cient collection development and collection management policy. This paper analyzes a total of 884,593 document delivery requests submitted to the National Academic Network and Information Center (ULAKBİM to identify a core journals collection, and to fi nd out if there is a relationship between the frequency of use of a journal and its impact factor and half-life (obsolescence. A total of 127 core journals satisfi ed one third of all document delivery requests (both remote and in-house requests. The number of core journals satisfying one third of all requests submitted to the Document Delivery Unit (DDU and Reference Services Reading Room (RDRR desk (in-library use was 184 and 97, respectively, and 87 of which were common. The mean half-life of all journals used in DDU was 10 years while it was 10.3 years for core journals only. The corresponding mean half-life for the same journals calculated on the basis of the number of citations taken from the Journal Citation Reports (2004 was 7.8 years. The mean half-life for all journals used in RDRR was 10 years while it was 7.6 years for core journals only. The corresponding citation-based mean half-life was also 7.6 years. No statistically meaningful relationship was observed between the frequencies of use of core journals and their impact factors. Yet, a low but statistically signifi cant relationship was observed between the use frequencies and total citation counts of RSRR core journals (Pearson’s r = .280, p less .01. Findings indicate that the frequencies of the local use of journals are more important than their impact factors and total citation counts when developing and managing a journals collection. Bir kütüphanenin etkin bir koleksiyon geliştirme ve koleksiyon yönetimi politikasının olabilmesi için, koleksiyonun kullanım

Kayalarda Delme ve Patlama

OpenAIRE

ÖZDOĞAN, Metin

1986-01-01

Bu makalede açık işletmecilikte delme ve patlatma işlemlerinin günümüzdeki kuramsal ve pratik durumu sunulmaktadır. Kayanın mekanik olarak parçalanması bölümünde vurmalı ve dönmeli delme dizgeleri verilmiştir. Kayanın devinik olarak parçalanması başlığı altında ise patlatma incelenmiş ve patlatma işlemini etkileyen etmenler, patlatma kuşakları, yansıma kuramı, krater deneylerine değinilmiştir

The Globular Cluster NGC 6402 (M14). II. Variable Stars

Science.gov (United States)

Contreras Peña, C.; Catelan, M.; Grundahl, F.; Stephens, A. W.; Smith, H. A.

2018-03-01

We present time-series BVI photometry for the Galactic globular cluster NGC 6402 (M14). The data consist of ∼137 images per filter, obtained using the 0.9 and 1.0 m SMARTS telescopes at the Cerro Tololo Inter-American Observatory. The images were obtained during two observing runs in 2006–2007. The image-subtraction package ISIS, along with DAOPHOT II/ALLFRAME, was used to perform crowded-field photometry and search for variable stars. We identified 130 variables, eight of which are new discoveries. The variable star population is comprised of 56 ab-type RR Lyrae stars, 54 c-type RR Lyrae, 6 type II Cepheids, 1 W UMa star, 1 detached eclipsing binary, and 12 long-period variables. We provide Fourier decomposition parameters for the RR Lyrae, and discuss the physical parameters and photometric metallicity derived therefrom. The M14 distance modulus is also discussed, based on different approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive =0.589 {{d}}{{a}}{{y}}{{s}}. This, together with the position of the RR Lyrae stars of both Bailey types in the period–amplitude diagram, suggests an Oosterhoff-intermediate classification for the cluster. Such an intermediate Oosterhoff type is much more commonly found in nearby extragalactic systems, and we critically discuss several other possible indications that may point to an extragalactic origin for this cluster. Based on observations obtained with the 0.9 m and 1 m telescopes at the Cerro Tololo Inter-American Observatory, Chile, operated by the SMARTS consortium.

Üniversite öğrencilerinde madde kullanımı, şiddet ve bazı psikolojik özellikler

Directory of Open Access Journals (Sweden)

Ebru Turhan

2011-06-01

Full Text Available ÖzetAmaç: Madde bağımlılığı günümüzde önemli bir halk sağlığı sorunudur. Bu çalışma, üniversite öğrencilerinde sigara, alkol ve uyuşturucu madde kullanımının yaygınlığını ve bunu etkileyen faktörleri araştırmak amacı ile yapıldı. Yöntem: Kesitsel tipteki bu araştırmada veriler, Hatay Mustafa Kemal Üniversitesi Eğitim Fakültesi, Ziraat Fakültesi ve Reyhanlı Sağlık Meslek Yüksek Okulu öğrencilerinden elde edildi.  Her fakülte ya da yüksek okuldan bir, iki, üç ve dördüncü sınıflardan birer şube seçildi ve sınıflarda ½ sistematik örneklem ile de öğrenciler seçildi. Çalışmaya toplam 396 öğrenci katıldı. Araştırmaya katılmayı kabul edenlere gözlem altında soru kağıdı uygulandı. Bulgular: Katılan öğrencilerin yaş ortalaması 20.9±2.3 ve %55.1’i erkektir.  Yaşam boyu sigara, alkol ve uyuşturucu madde kullanımı sırasıyla %73.2, %56.6 ve %9.6 idi. Erkeklerde sigara, alkol ve uyuşturucu madde kullanımı daha yüksek bulundu. Babasında ve kardeşinde sigara ve alkol kullanımı öyküsü olanlarda sigara ve alkol kullanımı daha yüksek saptandı.  Yakın akrabalarında uyuşturucu madde kullanımı bildirenlerde, uyuşturucu madde kullanımı daha fazla bulundu. Sigara kullananlarda şiddete uğrama ve şiddet uygulama, sigara içmeyenlere göre daha yüksek idi (p<0.001. Hayat boyu şiddete uğrayanların özgüven ve sosyal destek skorları düşük, sürekli kaygı puanları yüksek bulundu (p<0.01. Uçucu madde kullananlarda sürekli kaygı puanı yüksek (p<0.05, sosyal destek puanı düşük idi (p<0.05. Sonuç: Sigara içme, alkol ve uyuşturucu madde kullanımı Hatay’da üniversite öğrencilerinde yaygındır. Bulgularımız uçucu madde kullanımı ile yüksek sürekli kaygı ve düşük sosyal destek arasında ilişki olduğunu desteklemektedir.Anahtar Kelimeler: Madde kullanımı, üniversite öğrencileri, özsaygı, özgüven, kaygı, �

Studying RR Lyrae Stars in M4 with K2

Science.gov (United States)

Kuehn, Charles A.; Drury, Jason; Moskalik, Pawel

2017-01-01

Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomena, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During its campaign 2, K2 observed the globular cluster M4, providing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. We present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in the two observed RRc stars. In three RRab stars we have found the Blazhko effect with periods of 16.6 days, 22.4 days, and 44.5 days.

Demonstrating the Likely Neutron Star Nature of Five M31 Globular Cluster Sources with Swift-NuSTAR Spectroscopy

Science.gov (United States)

Maccarone, Thomas J.; Yukita, Mihoko; Hornschemeier, Ann; Lehmer, Bret D.; Antoniou, Vallia; Ptak, Andrew; Wik, Daniel R.; Zezas, Andreas; Boyd, Padi; Kennea, Jamie;

A reappraisal of the habitability of planets around M dwarf stars.

Science.gov (United States)

Tarter, Jill C; Backus, Peter R; Mancinelli, Rocco L; Aurnou, Jonathan M; Backman, Dana E; Basri, Gibor S; Boss, Alan P; Clarke, Andrew; Deming, Drake; Doyle, Laurance R; Feigelson, Eric D; Freund, Friedmann; Grinspoon, David H; Haberle, Robert M; Hauck, Steven A; Heath, Martin J; Henry, Todd J; Hollingsworth, Jeffery L; Joshi, Manoj M; Kilston, Steven; Liu, Michael C; Meikle, Eric; Reid, I Neill; Rothschild, Lynn J; Scalo, John; Segura, Antigona; Tang, Carol M; Tiedje, James M; Turnbull, Margaret C; Walkowicz, Lucianne M; Weber, Arthur L; Young, Richard E

2007-02-01

Stable, hydrogen-burning, M dwarf stars make up about 75% of all stars in the Galaxy. They are extremely long-lived, and because they are much smaller in mass than the Sun (between 0.5 and 0.08 M(Sun)), their temperature and stellar luminosity are low and peaked in the red. We have re-examined what is known at present about the potential for a terrestrial planet forming within, or migrating into, the classic liquid-surface-water habitable zone close to an M dwarf star. Observations of protoplanetary disks suggest that planet-building materials are common around M dwarfs, but N-body simulations differ in their estimations of the likelihood of potentially habitable, wet planets that reside within their habitable zones, which are only about one-fifth to 1/50th of the width of that for a G star. Particularly in light of the claimed detection of the planets with masses as small as 5.5 and 7.5 M(Earth) orbiting M stars, there seems no reason to exclude the possibility of terrestrial planets. Tidally locked synchronous rotation within the narrow habitable zone does not necessarily lead to atmospheric collapse, and active stellar flaring may not be as much of an evolutionarily disadvantageous factor as has previously been supposed. We conclude that M dwarf stars may indeed be viable hosts for planets on which the origin and evolution of life can occur. A number of planetary processes such as cessation of geothermal activity or thermal and nonthermal atmospheric loss processes may limit the duration of planetary habitability to periods far shorter than the extreme lifetime of the M dwarf star. Nevertheless, it makes sense to include M dwarf stars in programs that seek to find habitable worlds and evidence of life. This paper presents the summary conclusions of an interdisciplinary workshop (http://mstars.seti.org) sponsored by the NASA Astrobiology Institute and convened at the SETI Institute.

Cordia Sebestena Tohumunun ve Tohum Yağının Besinsel Özellikleri ve Potansiyel Değeri (İngilizce

Directory of Open Access Journals (Sweden)

Foluso O. Agunbiade

2015-02-01

Full Text Available Az kullanılan hammaddelerin geliştirilmesinin ivme kazanması ile iyi bilinen tohum ve tohum yağlarına olan aşırı bağımlılıktan ve bunun sonucundaki yüksek maliyetten dolayı geleneksel ve endüstriyel uygulamalar için az bilinen tohum ve tohum yağları türetilmiştir. Bu nedenle Cordia sebestena tohum ve tohum yağının kullanım potansiyeli bakımından besinsel özelliklerinin değerlendirilmesine yönelik bu çalışma yapılmıştır. Tohum yağında literatürde rapor edilen çeşitli analizler kullanılarak yağ asidi profili incelenmiş ve karakterize edilmişken, tohumda ise genel bileşim, mineral bileşenler ve anti-besinsel faktörler araştırılmıştır. Sonuçlar tohumun iyi bir yağ (%40.3 ± 0.8 ve protein (%11.5 ± 0.6 kaynağı olabileceğini göstermektedir. Tohum aynı zamanda Mg, Ca ve Na benzeri bazı makro-elementler ile esansiyel bir mikro-element olan Zn kaynağı olabilir. Anti-besinlerden fitat, tanen ve oksalat içeriği yüksektir ve gıdalarda tohumun kullanımı sakıncalı olabilir. Bu maddeler belki geleneksel gıda işleme yöntemleri ile giderilebilir. Tohum yağının özellikleri onun alkid reçine sentezinde, biyodizel ve sabun üretiminde kullanışlı olabileceğini göstermektedir. Yağ asidi profili toplam yağın %71.1 oranında insan tüketimi için iyi bir yağ asidi olan oleik asiti (C18:1 ağırlıklı olarak bulundurduğunu göstermektedir. Cordia sebestena tohumu ve tohum yağının önemli kullanım alanları olabileceği görülmüştür, ancak tohum yağının aminoasit profili ve anti-besinler üzerine geleneksel işlemlerin etkileri konularında daha fazla çalışmaya ihtiyaç vardır.

[α/Fe] ABUNDANCES OF FOUR OUTER M31 HALO STARS

International Nuclear Information System (INIS)

Vargas, Luis C.; Geha, Marla; Tollerud, Erik J.; Gilbert, Karoline M.; Kirby, Evan N.; Guhathakurta, Puragra

2014-01-01

We present alpha element to iron abundance ratios, [α/Fe], for four stars in the outer stellar halo of the Andromeda Galaxy (M31). The stars were identified as high-likelihood field halo stars by Gilbert et al. and lie at projected distances between 70 and 140 kpc from M31's center. These are the first alpha abundances measured for a halo star in a galaxy beyond the Milky Way. The stars range in metallicity between [Fe/H] = –2.2 and [Fe/H] = –1.4. The sample's average [α/Fe] ratio is +0.20 ± 0.20. The best-fit average value is elevated above solar, which is consistent with rapid chemical enrichment from Type II supernovae. The mean [α/Fe] ratio of our M31 outer halo sample agrees (within the uncertainties) with that of Milky Way inner/outer halo stars that have a comparable range of [Fe/H

Inhomogeneous structure in the chromospheres of dwarf M stars

Science.gov (United States)

Turner, N. J.; Cram, L. E.; Robinson, R. D.

1991-01-01

Linear combinations of observed spectra of the H-alpha and Ca-II resonance and IR lines from the chromospheres of a quiet (Gl 1) and an active (Gl 735) dwarf-M star are compared with the corresponding spectra from a star of intermediate activity (Gl 887). It is shown that the intermediate spectra cannot be explained as a simple juxtaposition of the extreme chromospheric states. It is concluded that the range of observed strengths of chromospheric activity indicators in dwarf-M stars is due, at least in part, to changes in the radial structure of the chromospheric heating function and not to changes in the area filling factor.

MOTION VERIFIED RED STARS (MoVeRS): A CATALOG OF PROPER MOTION SELECTED LOW-MASS STARS FROM WISE, SDSS, AND 2MASS

Energy Technology Data Exchange (ETDEWEB)

Theissen, Christopher A.; West, Andrew A. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Dhital, Saurav, E-mail: ctheisse@bu.edu [Department of Physical Sciences, Embry-Riddle Aeronautical University, 600 South Clyde Morris Blvd., Daytona Beach, FL 32114 (United States)

2016-02-15

We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS Data Release 10 (DR10), Two Micron All-Sky Survey (2MASS) point-source catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r − i, i − z, r − z, z − J, and z − W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2σ uncertainty were included. Our Motion Verified Red Stars catalog is available through SDSS CasJobs and VizieR.

The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3

Science.gov (United States)

Sneden, Christopher; Kraft, Robert P.; Guhathakurta, Puragra; Peterson, Ruth C.; Fulbright, Jon P.

2004-04-01

We report new chemical abundances of 23 bright red giant members of the globular cluster M3, based on high-resolution (R~45,000) spectra obtained with the Keck I telescope. The observations, which involve the use of multislits in the HIRES Keck I spectrograph, are described in detail. Combining these data with a previously reported small sample of M3 giants obtained with the Lick 3 m telescope, we compare metallicities and [X/Fe] ratios for 28 M3 giants with a 35-star sample in the similar-metallicity cluster M13, and with Galactic halo field stars having [Fe/H]=A(Si), we derive little difference in [X/Fe] ratios in the M3, M13, or halo field samples. All three groups exhibit C depletion with advancing evolutionary state beginning at the level of the red giant branch ``bump,'' but the overall depletion of about 0.7-0.9 dex seen in the clusters is larger than that associated with the field stars. The behaviors of O, Na, Mg, and Al are distinctively different among the three stellar samples. Field halo giants and subdwarfs have a positive correlation of Na with Mg, as predicted from explosive or hydrostatic carbon burning in Type II supernova sites. Both M3 and M13 show evidence of high-temperature proton-capture synthesis from the ON, NeNa, and MgAl cycles, while there is no evidence for such synthesis among halo field stars. But the degree of such extreme proton-capture synthesis in M3 is smaller than it is in M13: the M3 giants exhibit only modest deficiencies of O and corresponding enhancements of Na, less extreme overabundances of Al, fewer stars with low Mg and correspondingly high Na, and no indication that O depletions are a function of advancing evolutionary state, as has been claimed for M13. We have also considered NGC 6752, for which Mg isotopic abundances have been reported by Yong et al. Giants in NGC 6752 and M13 satisfy the same anticorrelation of O abundances with the ratio (25Mg+26Mg)/24Mg, which measures the relative contribution of rare to

Big Fish in Small Ponds: massive stars in the low-mass clusters of M83

Energy Technology Data Exchange (ETDEWEB)

Andrews, J. E.; Calzetti, D.; McElwee, Sean [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Chandar, R. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Elmegreen, B. G. [IBM T. J. Watson Research Center, Yorktown Heights, NY 10598 (United States); Kennicutt, R. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Kim, Hwihyun [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Krumholz, Mark R. [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Lee, J. C.; Whitmore, B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); O' Connell, R. W., E-mail: jandrews@astro.umass.edu, E-mail: callzetti@astro.umass.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2014-09-20

We have used multi-wavelength Hubble Space Telescope WFC3 data of the starbursting spiral galaxy M83 in order to measure variations in the upper end of the stellar initial mass function (uIMF) using the production rate of ionizing photons in unresolved clusters with ages ≤ 8 Myr. As in earlier papers on M51 and NGC 4214, the uIMF in M83 is consistent with a universal IMF, and stochastic sampling of the stellar populations in the ∼<10{sup 3} M {sub ☉} clusters are responsible for any deviations in this universality. The ensemble cluster population, as well as individual clusters, also imply that the most massive star in a cluster does not depend on the cluster mass. In fact, we have found that these small clusters seem to have an over-abundance of ionizing photons when compared to an expected universal or truncated IMF. This also suggests that the presence of massive stars in these clusters does not affect the star formation in a destructive way.

Hâkim Tasarım ve Ekşi Sözlük: İnternet’in Dönüşümünü Anlamak

Directory of Open Access Journals (Sweden)

Babacan Taşdemir

2014-02-01

Full Text Available Son yıllarda bir yanda devletler, diğer yanda sermaye kuruluşları, siyasi, idari ve ticari amaçları ile İnternet ortamını gittikçe daha fazla kolonileştirmektedirler. Bu da siyasi ve ticari baskılardan azade bir özgürlük alanı olarak görülen İnternet’e ilişkin toplumsal beklentilere zıt bir durum ortaya çıkarmaktadır. Çalışmamız, İnternet’teki bu dönüşümü üretim gücü ve üretim ilişkileri kavramları üzerinden eleştirel bir gözle değerlendirmeyi önermektedir. Dönüşüm, ‘Teknolojik Değişimin Döngüsel Modeli’ndeki ‘mayalanma dönemi’ ve ‘hâkim tasarım’ kavramlarının sunduğu potansiyelden faydalanılarak açıklanmaya çalışılmaktadır.  Burada ‘mayalanma dönemi’ ile İnternette ifade özgürlüğü açısından daha uygun olan ilk dönemlere, ‘hâkim tasarım’ ile ise yerleşik üretim ve iktidar ilişkilerinin daha fazla nüfuz ettiği yakın döneme gönderme yapılmaktadır. Ekşi Sözlük örneği ile de savlarını destekleyen çalışmamız, üç kategori üzerinden örnek olaylarla Sözlük’ün dönüşümünü değerlendirmektedir: İş çevreleriyle ticari ilişkilere bağlı dönüşüm, İnternet’in düzenlenmesine dair hukuki çerçeve ve kamu otoriteleri ile ilişkilere bağlı olarak geçirilen dönüşüm, Sözlük kullanıcıları ve sahipleri arasındaki örgütsel ilişkinin değişimi dolayımında geçirilen dönüşüm. Sonuç olarak, İnternet’in ‘mayalanma döneminde’, yani görece serbest bir ortamda, Ekşi Sözlük popülaritesini ve saygınlığını, yaratıcı ve muhalif duruş ile karakterize olan bir ifade alanı olarak kazansa da, zaman içinde tamamen kâr merkezli bir işletmeye dönüşmektedir. Böylece bir yandan pazarlama stratejilerinin ana mecralarından biri diğer yandan da politik baskıya tabii sıradan bir forum ve paylaşım sitesi haline gelmektedir. Sözlük’ün gelişimine ilişkin örnek olaylar ele

Geometrik Yapıların İnşasında Pergel ve Çizgecin Kullanımı

OpenAIRE

Erduran, Ayten; Yeşildere, Sibel

2010-01-01

Bu yapıda üç matematik öğretinin pergel ve çizgeçmenin geometrik yapıları süreçleri incelenmektedir. Öğretmenlerin geometri yapı yapımı ve ilgili dersleri video kamera ile kaydedilmiş ve derslerdeki öğretmen-öğrenci-araç üçlüsü arasındaki etkileşim incelenmiştir. Ders Kitaplığı içeren öğretmenlerle görüşmeler yapıldı. Çalışmada üç matematik öğretmeninin pergel ve çizgeci geometrik yapılar yapı mühendisliği. Araştırma pergel ve çizgeçle geometrik yapıların inşasına ezbere bir anlayışla öğretme...

Teknokent’lerde Geliştirilen Yazılım Projelerinin Risk Analizi ve Başarı Düzeyleri

Directory of Open Access Journals (Sweden)

M.Hanefi CALP

2014-08-01

Full Text Available Günlük hayatın hemen her alanında ihtiyaç duyulan yazılım projeleri her geçen gün daha fazla büyümekte ve daha çok önem arz etmektedir. Bununla birlikte, büyüyen bu yazılımlar beraberinde daha karmaşık bir yapıyı doğurmaktadır. Bu bağlamda, sözkonusu yazılım projelerinin analiz ve kontrol süreci, ayrıca başarı düzeyleri merak edilmektedir. Dolayısıyla bu çalışmada, geliştirilen anket formlarında bulunan kontrol listeleri aracılığıyla, Teknokent’lerde geliştirilen yazılım projelerinde karşılaşılan risk faktörlerini belirlemek, analiz etmek ve bu projelerin başarı düzeylerini ortaya koymak amaçlanmıştır. Bu amaçla, gerekli olan veriler toplanmış, yazılım risk faktörleri belirlenmiş ve sözkonusu faktörler analiz edilmiştir. Araştırma kapsamında elde edilen verilerin analizi için betimsel analiz yönteminden yararlanılmış olup, Microsoft Excel 2010 ve IBM SPSS Statistics 21.0 programları kullanılmıştır. Ayrıca, çalışmada analiz sonuçlarına ve geliştirilen yazılımların başarı düzeylerine ayrıntılı bir şekilde yer verilmiştir. Elde edilen sonuçlar içerisinde özellikle; proje süresi, bütçesi, personel sayısı ve hedeflerdeki sapmalara rağmen Teknokent’lerde geliştirilen yazılım projelerinin yaklaşık %95’inin başarıyla sonuçlandırılmış ve müşteriye teslim edilmiş olması dikkat çekmektedir.Anahtar Kelimeler: Yazılım, Risk faktörleri, Risk analizi, Proje başarısı

Yazılım geliştiricilerin kullanıcı deneyimi ve kullanılabilirlik konusundaki farkındalıklarının ve bilgi seviyelerinin belirlenmesi

Directory of Open Access Journals (Sweden)

Yavuz İnal

2016-10-01

Full Text Available Bu çalışma yazılım geliştiricilerinin kullanıcı deneyimi ve kullanılabilirlik konularındaki farkındalıklarının ve bilgi seviyelerinin belirlenmesi amacıyla yapılmıştır. Bunun yanında katılımcıların kullanılabilirlik aktivitelerinin yazılım geliştirme süreçlerine hangi aşamada dâhil edilmesi gereği konusundaki düşünceleri analiz edilmiştir. Çalışmaya 59 yazılım geliştiricisi katılmıştır. Çalışmanın ilk bölümünde veriler anket aracılığıyla toplanmıştır. Çalışmanın ikinci bölümünde ise, katılımcılar arasından gönüllülük esasına göre seçilen bir grup yazılım geliştirici ile ayrıntılı mülakat yapılmış ve konuyla ilgili detaylı bilgi alınmıştır. Çalışmada elde edilen bulgulara göre yazılım geliştiricilerinin önemli bir bölümünün bu konularda herhangi bir eğitim almadıkları belirlenmiştir. Geliştiricilerin çoğunun kendilerini yazılım projesi geliştirme ekibi içerisinde kullanıcı deneyimi ve kullanılabilirlik konularında en az farkındalığa ve bilgiye sahip grup olarak gördükleri belirlenmiştir. Bunun yanında katılımcıların kullanıcı deneyimi ve kullanılabilirlik gibi kavramlara yönelik eksik ya da yanlış bilgi sahibi oldukları görülmüştür.

HAZMAT. III. The UV Evolution of Mid- to Late-M Stars with GALEX

Science.gov (United States)

Schneider, Adam C.; Shkolnik, Evgenya L.

2018-03-01

Low-mass stars are currently the most promising targets for detecting and characterizing habitable planets in the solar neighborhood. However, the ultraviolet (UV) radiation emitted by such stars can erode and modify planetary atmospheres over time, drastically affecting their habitability. Thus, knowledge of the UV evolution of low-mass stars is critical for interpreting the evolutionary history of any orbiting planets. Shkolnik & Barman used photometry from the Galaxy Evolution Explorer (GALEX) to show how UV emission evolves for early-type M stars (>0.35 M ⊙). In this paper, we extend their work to include both a larger sample of low-mass stars with known ages as well as M stars with lower masses. We find clear evidence that mid- and late-type M stars (0.08–0.35 M ⊙) do not follow the same UV evolutionary trend as early-Ms. Lower-mass M stars retain high levels of UV activity up to field ages, with only a factor of 4 decrease on average in GALEX NUV and FUV flux density between young (flux density ratio, which can affect the photochemistry of important planetary biosignatures, is mass- and age-dependent for early-Ms, but remains relatively constant for the mid- and late-type Ms in our sample.

THE FMOS-COSMOS SURVEY OF STAR-FORMING GALAXIES AT z ∼ 1.6. I. Hα-BASED STAR FORMATION RATES AND DUST EXTINCTION

Energy Technology Data Exchange (ETDEWEB)

Kashino, D.; Sugiyama, N. [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya 464-8602 (Japan); Silverman, J. D. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, Kashiwanoha, Kashiwa 277-8583 (Japan); Rodighiero, G. [Dipartimento di Astronomia, Università di Padova, vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Renzini, A. [INAF Osservatorio Astronomico di Padova, vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Arimoto, N. [National Astronomical Observatory of Japan, Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); Daddi, E. [CEA-Saclay, Service d' Astrophysique, F-91191 Gif-sur-Yvette (France); Lilly, S. J.; Carollo, C. M. [Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-strasse 27, 8093 Zürich (Switzerland); Sanders, D. B.; Zahid, H. J.; Chu, J.; Hasinger, G.; Kewley, L. J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Kartaltepe, J. [National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ 85719 (United States); Nagao, T. [The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8302 (Japan); Capak, P. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Ilbert, O. [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Kajisawa, M. [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Koekemoer, A. M., E-mail: daichi@nagoya-u.jp [HST and JWST Instruments/Science Division, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

2013-11-01

We present the first results from a near-IR spectroscopic survey of the COSMOS field, using the Fiber Multi-Object Spectrograph on the Subaru telescope, designed to characterize the star-forming galaxy population at 1.4 < z < 1.7. The high-resolution mode is implemented to detect Hα in emission between 1.6-1.8 μm with f {sub Hα} ∼> 4 × 10{sup –17} erg cm{sup –2} s{sup –1}. Here, we specifically focus on 271 sBzK-selected galaxies that yield a Hα detection thus providing a redshift and emission line luminosity to establish the relation between star formation rate and stellar mass. With further J-band spectroscopy for 89 of these, the level of dust extinction is assessed by measuring the Balmer decrement using co-added spectra. We find that the extinction (0.6 ∼< A {sub Hα} ∼< 2.5) rises with stellar mass and is elevated at high masses compared to low-redshift galaxies. Using this subset of the spectroscopic sample, we further find that the differential extinction between stellar and nebular emission E {sub star}(B – V)/E {sub neb}(B – V) is 0.7-0.8, dissimilar to that typically seen at low redshift. After correcting for extinction, we derive an Hα-based main sequence with a slope (0.81 ± 0.04) and normalization similar to previous studies at these redshifts.

Population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) following an intracoelomic injection or extended immersion.

Science.gov (United States)

Rosenberg, Justin F; Haulena, Martin; Phillips, Brianne E; Harms, Craig A; Lewbart, Gregory A; Lahner, Lesanna L; Papich, Mark G

2016-11-01

OBJECTIVE To determine population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) administered an intracoelomic injection of enrofloxacin (5 mg/kg) or immersed in an enrofloxacin solution (5 mg/L) for 6 hours. ANIMALS 28 sea stars of undetermined age and sex. PROCEDURES The study had 2 phases. Twelve sea stars received an intracoelomic injection of enrofloxacin (5 mg/kg) or were immersed in an enrofloxacin solution (5 mg/L) for 6 hours during the injection and immersion phases, respectively. Two untreated sea stars were housed with the treated animals following enrofloxacin administration during both phases. Water vascular system fluid samples were collected from 4 sea stars and all controls at predetermined times during and after enrofloxacin administration. The enrofloxacin concentration in those samples was determined by high-performance liquid chromatography. For each phase, noncompartmental analysis of naïve averaged pooled samples was used to obtain initial parameter estimates; then, population pharmacokinetic analysis was performed that accounted for the sparse sampling technique used. RESULTS Injection phase data were best fit with a 2-compartment model; elimination half-life, peak concentration, area under the curve, and volume of distribution were 42.8 hours, 18.9 μg/mL, 353.8 μg•h/mL, and 0.25 L/kg, respectively. Immersion phase data were best fit with a 1-compartment model; elimination half-life, peak concentration, and area under the curve were 56 hours, 36.3 μg•h/mL, and 0.39 μg/mL, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the described enrofloxacin administration resulted in water vascular system fluid drug concentrations expected to exceed the minimum inhibitory concentration for many bacterial pathogens.

Hücre siklusu ve kanser

OpenAIRE

Cabadak, Hülya

2008-01-01

Hücre çogalması ve hücre siklusunun ilerlemesi büyümenin kontrolünde rolü olan genlerin ekspresyonu ile baglantılıdır. Ökaryot hücre siklusuM(mitoz) G , S ve G fazlarından olusmaktadır. Bu süreçte hücre uyarımı ve büyüme meydana gelir veya hücre G fazında durmaktadır. Hücre siklusunda G -S geçisinde, G -Mgeçisinde ve metafaz-anafaz geçisinde kontrol noktaları bulunmaktadır. Hücre siklusu siklin bagımlı kinazlar (cdk, katalitik altbirim) ve siklin (cyc, düzenleyici altbirim) tarafı...

BVI photometry of star clusters in M33

International Nuclear Information System (INIS)

Christian, C.A.; Schommer, R.A.

1988-01-01

CCD images of candidate star clusters in M33 were obtained for 13 fields in the B, V, and I bandpasses. The integrated visual colors and magnitudes are used to study the clusters, and evidence for extended giant branches and possibly carbon stars in several of the intermediate-aged clusters is presented. The colors, magnitudes, and positions are used to analyze stellar population of M33 and confirm the existence of massive star clusters with a 0.1-10-Gyr age range. That is, the cluster system of M33 shares some similarities to that of the Magellanic Clouds in that relatively massive clusters are found at all ages. In addition, more than 20 true (i.e., old, massive) globulars are identified. A substantial population of intermediate-color clusters are found, and it is argued that the cluster-formation rate for clusters less than 10 Gyr old may be more continuous in M33 than in the Magellanic Clouds. The chemical evolution of M33 as traced by the clusters suggests that an abundance gradient existed at all ages, in that the outer regions of the disk (i.e., R greater than 10 arcmin or 2 kpc) follow a slow enhancement history similar to the SMC, while the inner regions were enriched more dramatically. 59 references

Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram

Energy Technology Data Exchange (ETDEWEB)

Humphreys, Roberta M.; Davidson, Kris; Hahn, David [Minnesota Institute for Astrophysics, 116 Church St SE, University of Minnesota, Minneapolis, MN 55455 (United States); Martin, John C. [Barber Observatory, University of Illinois, Springfield, IL 62703 (United States); Weis, Kerstin, E-mail: roberta@umn.edu [Astronomical Institute, Ruhr-Universitaet Bochum (Germany)

2017-07-20

We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with the infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.

Surprisingly different star-spot distributions on the near equal-mass equal-rotation-rate stars in the M dwarf binary GJ 65 AB

Science.gov (United States)

Barnes, J. R.; Jeffers, S. V.; Haswell, C. A.; Jones, H. R. A.; Shulyak, D.; Pavlenko, Ya. V.; Jenkins, J. S.

2017-10-01

We aim to understand how stellar parameters such as mass and rotation impact the distribution of star-spots on the stellar surface. To this purpose, we have used Doppler imaging to reconstruct the surface brightness distributions of three fully convective M dwarfs with similar rotation rates. We secured high cadence spectral time series observations of the 5.5 au separation binary GJ 65, comprising GJ 65A (M5.5V, Prot = 0.24 d) and GJ 65B (M6V, Prot = 0.23 d). We also present new observations of GJ 791.2A (M4.5V, Prot = 0.31 d). Observations of each star were made on two nights with UVES, covering a wavelength range from 0.64 - 1.03μm. The time series spectra reveal multiple line distortions that we interpret as cool star-spots and which are persistent on both nights suggesting stability on the time-scale of 3 d. Spots are recovered with resolutions down to 8.3° at the equator. The global spot distributions for GJ 791.2A are similar to observations made a year earlier. Similar high latitude and circumpolar spot structure is seen on GJ 791.2A and GJ 65A. However, they are surprisingly absent on GJ 65B, which instead reveals more extensive, larger, spots concentrated at intermediate latitudes. All three stars show small amplitude latitude-dependent rotation that is consistent with solid body rotation. We compare our measurements of differential rotation with previous Doppler imaging studies and discuss the results in the wider context of other observational estimates and recent theoretical predictions.

Kinematics and M(sub v) calibration of K and M dwarf stars using Hipparcos data

Science.gov (United States)

Upgren, A. R.; Ratnatunga, K. U.; Casertano, S.; Weis, E.

1997-01-01

The luminosities and kinematics of lower main sequence stars in a spectroscopically selected sample covering spectral types K 3 to M 5 are determined using Hipparcos parallaxes and proper motions. The stars separate into two kinematically distinct components, called young disk and old disk components. The young component has velocity dispersion (30, 17, 12) km/s in the U, V and W directions, respectively, and features an asymmetric drift of 8 km/s, a vertex deviation of 10 +/- 3 deg and an absolute magnitude of 10.48 mag at color (R - I)(sub Kron) = 1.0 mag. The respective features of the old component are: (56, 34, 31) km/s, 28 km/s and 0.6 mag at the same color. The slope and intrinsic width of the magnitude calibration of each component are determined. The analysis is used to investigate the possible presence of residual systematic discrepancies of the model with Hipparcos data. There are indications of a possible underestimation of the parallax errors.

Rodinný dům ve svahu

OpenAIRE

Hrubý, Libor

2013-01-01

Bakalářská práce, zabývající se projektovou dokumentací stavební části ve stupni pro provedení stavby na novostavbu samostatně stojícího rodinného domu ve svahu. Objekt je dvoupodlažní, podsklepený. Svislé konstrukce z vápenopískového zdícího systému KM Beta Sendwix. Stropní konstrukce z předpjatých stropních panelů Spiroll. Zastřešení provedeno pultovou vegetační střechou se sklonem 10%, plochou střechou s terasovou úpravou a plochou vegetační střechou. Dispozičně je objekt rozdělen na klido...

The Frequency of Binary Stars in the Globular Cluster M71

Science.gov (United States)

Barden, S. C.; Armandroff, T. E.; Pryor, C. P.

1994-12-01

The frequency of binary stars is a fundamental property of a stellar population. A comparison of the frequency of binaries in globular clusters with those in the field halo and disk populations tests the similarity of star formation in those environments. Binary stars in globular clusters also act as an energy source which ``heats" the cluster through super-elastic encounters with other stars and binaries. Such encounters can not only profoundly affect the dynamical evolution of the cluster, they can disrupt the widely separated binaries and catalyze the formation of exotic objects such as blue stragglers, x-ray binaries, and milli-second pulsars. We have used the KPNO 4-m and the multi-fiber instruments Nessie and Hydra to measure radial velocities at 4 epochs over two years for a sample of 126 stars in the globular cluster M71. Velocity errors are under 1 km s(-1) for the brighter stars and under 2 km s(-1) for the majority of our data set. These velocities will be valuable for studying the kinematics of M71, but here we focus on searching for binaries. The faintest stars are at V=17, or just above the main sequence turnoff. Our sample is thus deeper than any published globular cluster binary search utilizing spectroscopic techniques. By observing smaller stars, we double the number of decades of binary periods sampled compared to previous studies and come within a factor of 4 of the shortest possible periods for turnoff stars. This wider period window has produced the largest known sample of binaries in a globular cluster. Four stars show velocity ranges larger than 20 km s(-1) , nine have ranges larger than 10 km s(-1) , and others are clearly variable. We will compare the radial distribution of these stars to that predicted by theory and derive the main-sequence binary fraction.

THE MASSIVE STAR POPULATION IN M101. I. THE IDENTIFICATION AND SPATIAL DISTRIBUTION OF THE VISUALLY LUMINOUS STARS

International Nuclear Information System (INIS)

Grammer, Skyler; Humphreys, Roberta M.

2013-01-01

An increasing number of non-terminal giant eruptions are being observed by modern supernova and transient surveys. But very little is known about the origin of these giant eruptions and their progenitors, many of which are presumably very massive, evolved stars. Motivated by the small number of progenitors positively associated with these giant eruptions, we have begun a survey of the evolved massive star populations in nearby galaxies. The nearby, nearly face-on, giant spiral M101 is an excellent laboratory for studying a large population of very massive stars. In this paper, we present BVI photometry obtained from archival HST/ACS Wide Field Camera images of M101. We have produced a catalog of luminous stars with photometric errors <10% for V < 24.5 and 50% completeness down to V ∼ 26.5 even in regions of high stellar crowding. Using color and luminosity criteria, we have identified candidate luminous OB-type stars and blue supergiants, yellow supergiants, and red supergiants for future observation. We examine their spatial distributions across the face of M101 and find that the ratio of blue to red supergiants decreases by two orders of magnitude over the radial extent of M101 corresponding to 0.5 dex in metallicity. We discuss the resolved stellar content in the giant star-forming complexes NGC 5458, 5453, 5461, 5451, 5462, and 5449 and discuss their color-magnitude diagrams in conjunction with the spatial distribution of the stars to determine their spatio-temporal formation histories

CARBON STARS IN THE SATELLITES AND HALO OF M31

Energy Technology Data Exchange (ETDEWEB)

Hamren, Katherine; Guhathakurta, Puragra; Rockosi, Constance M.; Smith, Graeme H. [Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Beaton, Rachael L. [The Observatories of the Carnegie Institutions for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Gilbert, Karoline M.; Tollerud, Erik J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Boyer, Martha L. [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Howley, Kirsten, E-mail: khamren@ucolick.org [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States)

2016-09-01

We spectroscopically identify a sample of carbon stars in the satellites and halo of M31 using moderate-resolution optical spectroscopy from the Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo survey. We present the photometric properties of our sample of 41 stars, including their brightness with respect to the tip of the red giant branch (TRGB) and their distributions in various color–color spaces. This analysis reveals a bluer population of carbon stars fainter than the TRGB and a redder population of carbon stars brighter than the TRGB. We then apply principal component analysis to determine the sample’s eigenspectra and eigencoefficients. Correlating the eigencoefficients with various observable properties reveals the spectral features that trace effective temperature and metallicity. Putting the spectroscopic and photometric information together, we find the carbon stars in the satellites and halo of M31 to be minimally impacted by dust and internal dynamics. We also find that while there is evidence to suggest that the sub-TRGB stars are extrinsic in origin, it is also possible that they are are particularly faint members of the asymptotic giant branch.

A PHOTOMETRIC VARIABILITY SURVEY OF FIELD K AND M DWARF STARS WITH HATNet

International Nuclear Information System (INIS)

Hartman, J. D.; Bakos, G. A.; Noyes, R. W.; Sipocz, B.; Pal, A.; Kovacs, G.; Mazeh, T.; Shporer, A.

2011-01-01

Using light curves from the HATNet survey for transiting extrasolar planets we investigate the optical broadband photometric variability of a sample of 27, 560 field K and M dwarfs selected by color and proper motion (V - K ∼> 3.0, μ > 30 mas yr -1 , plus additional cuts in J - H versus H - K S and on the reduced proper motion). We search the light curves for periodic variations and for large-amplitude, long-duration flare events. A total of 2120 stars exhibit potential variability, including 95 stars with eclipses and 60 stars with flares. Based on a visual inspection of these light curves and an automated blending classification, we select 1568 stars, including 78 eclipsing binaries (EBs), as secure variable star detections that are not obvious blends. We estimate that a further ∼26% of these stars may be blends with fainter variables, though most of these blends are likely to be among the hotter stars in our sample. We find that only 38 of the 1568 stars, including five of the EBs, have previously been identified as variables or are blended with previously identified variables. One of the newly identified EBs is 1RXS J154727.5+450803, a known P = 3.55 day, late M-dwarf SB2 system, for which we derive preliminary estimates for the component masses and radii of M 1 = M 2 = 0.258 ± 0.008 M sun and R 1 = R 2 = 0.289 ± 0.007 R sun . The radii of the component stars are larger than theoretical expectations if the system is older than ∼200 Myr. The majority of the variables are heavily spotted BY Dra-type stars for which we determine rotation periods. Using this sample, we investigate the relations between period, color, age, and activity measures, including optical flaring, for K and M dwarfs, finding that many of the well-established relations for F, G, and K dwarfs continue into the M dwarf regime. We find that the fraction of stars that is variable with peak-to-peak amplitudes greater than 0.01 mag increases exponentially with the V - K S color such that

High-Speed Ultracam Colorimetry of the Subdwarf B Star SDSS J171722.08+58055.8

NARCIS (Netherlands)

Aerts, C.C.; Jeffery, C.S.; Dhillon, V.S.; Marsh, T.R.; Groot, P.J.

2006-01-01

We present high-speed multicolour photometry of the faint sub-dwarf B star SDSS J171722.08+58055.8 (m_B=16.7mag), which was recently discovered to be pulsating. The data were obtained during two consecutive nights in 2004 August using the three-channel photometer Ultracam attached to the

THE STAR CLUSTER SYSTEM IN THE NEARBY STARBURST GALAXY M82

International Nuclear Information System (INIS)

Lim, Sungsoon; Lee, Myung Gyoon; Hwang, Narae

2013-01-01

We present a photometric study of star clusters in the nearby starburst galaxy M82 based on the UBVI-, YJ- and H-band Hubble Space Telescope images. We find 1105 star clusters with V 0 ≈ 0.45, and a weaker red population. The luminosity function of the disk clusters shows a power-law distribution with a power-law index α = –2.04 ± 0.03, and the scale height of their distribution is h z = 9.''64 ± 0.''40 (164 ± 7 pc), similar to that of the stellar thin disk of M82. We have derived the ages of ∼630 star clusters using the spectral energy distribution fit method by comparing UBVI(YJ)H-band photometric data with the simple stellar population models. The age distribution of the disk clusters shows that the most dominant cluster population has ages ranging from 100 Myr to 1 Gyr, with a peak at about 500 Myr. This suggests that M82 has undergone a disk-wide star formation about 500 Myr ago, probably through the interaction with M81. The brightest star clusters in the nuclear region are much brighter than those in other regions, indicating that more massive star clusters are formed in the denser environments. On the other hand, the colors of the halo clusters are similar to those of globular clusters in the Milky Way, and their ages are estimated to be older than 1 Gyr. These are probably genuine old globular clusters in M82.

8-12 GHz Radio Observations of Flare Activity On M dwarf CN Leo

Science.gov (United States)

Wofford, Alia; Villadsen, Jackie; Quintana, Elisa; Barclay, Thomas; Thackeray, Beverly

2018-01-01

Red dwarfs are cool stars that make up 70% of all stars. Red dwarfs can be utilized to detect potentially habitable planets but they have particularly strong magnetic activity that can be detrimental to orbiting planets’ atmospheres and habitability. A coronal mass ejection (CME) is an eruption of magnetized plasma from the star that is ejected into the interplanetary medium which can erode a planet’s atmosphere daily. Based on the sun CMEs are expected to produce very bright radio bursts along with optical flares. We are using M dwarf CN Leo, a well studied flare star that was in the K2 campaign field in summer 2017, as a template to understand the relationship between radio and optical flares and the space weather conditions impacting M dwarf planets. Using radio frequencies ranging from 0.22 GHz-12 GHz we search for simultaneous radio bursts and optical flares to infer if CMEs, flares or aurorae are occurring on the star. I will present the 8-12 GHz radio data from eight 1.5-hour observations with simultaneous optical data. CN Leo produced a bright non-thermal radio flare that lasted approximately for a day during two consecutive observations, with a gyrosynchrotron emission mechanism.

EXAMINATION OF TEXTS AT MEB 6, 7 AND 8. GRADE TURKISH COURSE TEXTBOOKS ACCORDING TO VALUE TRANSMISSION MEB 6, 7 VE 8. SINIF TÜRKÇE DERS KİTAPLARINDA YER ALAN METİNLERİN DEĞER İLETİMİ AÇISINDAN İNCELENMESİ

Directory of Open Access Journals (Sweden)

Esra EKİNCİ ÇELİKPAZU

2011-06-01

Full Text Available In our contemporary society which humanistic emotions are corrupting due to increase in technological advances, there is a need for effective value education to train persons who are honest ambitious, hardworking and capable of empathy, who have respect for each other without losing feelings of love and tolerance, who give very importance to science and rationalism. Schools are social institutions which enable the continuity of society by transmission of national and universal values. The course textbooks, which are an indispensable part of education process, have an important role in the transmission of values. Students gain national and universal values through the literary works in course textbooks which are established by benefiting from the richness of mother tongue and its vocabulary. The purpose of this study is to determine which national and universal values are delivered through the reading texts of Primary Education 6th, 7th and 8th grade Turkish textbooks, and to determine how these values are distributed at 6th, 7th and 8th grade Turkish textbooks. This study used document analysis method which is a qualitative research method. The sample of the survey is established of 6th, 7th and 8th grade Turkish textbooks which are published by National Education Ministry (MEB. By examining reading texts in the textbooks according to “Values Assessment Form (VAF”, it is tried to determine which national and universal values are delivered through texts. In this study, it is found that, texts at MEB 6th, 7th and 8th grade Turkish textbooks did not deliver values at the desired level and value transmission is more intense at 6th grade and has been reduced at 7th and 8th grades Teknolojik gelişmelere paralel olarak insanî duyguların köreldiği günümüz toplumlarında, birbirlerine karşı saygı, sevgi ve hoşgörü duygularını kaybetmeden bilimselliğe ve akılcılığa önem veren, empati kurabilen, azimli, çalışkan ve d

Radio-wavelength observations of magnetic fields on active dwarf-M, RS CVN and magnetic stars

Energy Technology Data Exchange (ETDEWEB)

Lang, K.R.

1986-01-01

The dwarf M stars YZ Canis Minoris and AD Leonis exhibit narrow band, slowly varying (hours) microwave emission that cannot be explained by conventional thermal radiation mechanisms. The dwarf M stars AD Leonis and Wolf 424 emit rapid spikes whose high brightness temperatures similarly require a nonthermal radiation process which could result from coherent mechanisms such as an electron-cyclotron maser or coherent-plasma radiation. If the electron-cyclotron maser emits at the second or third harmonic of the gyrofrequency, the coronal magnetic field strength H = 250 or 167 G and constraints on the plasma frequency imply an electron density of 6 x 10/sup 9//cm/sup 3/. Coherent-plasma radiation requires similar values of electron density but much weaker magnetic fields. Radio spikes from AD Leonis and Wolf 424 have rise times tau/sub R/ < 5 ms, indicating a linear size of L < 1.5 x 10/sup 8/ cm, or less than 0.005 of the stellar radius. Although Ap magnetic stars have strong dipole magnetic fields, they exhibit no detectable gyroresonant radiation, suggesting that these stars do not have hot, dense coronae. The binary RS CVn star UX Arietis exhibits variable emission at 6 cm wavelength on time scales ranging from 30 s to more than one hour. The shortest variation implies a linear size much less than that of the halo observed by VLBI techniques, and most probably sizes smaller than those of the component stars. The observed variations might be due to absorption by a thermal plasma located between the stars.

On the Spatially Resolved Star Formation History in M51. I. Hybrid UV+IR Star Formation Laws and IR Emission from Dust Heated by Old Stars

Science.gov (United States)

Eufrasio, R. T.; Lehmer, B. D.; Zezas, A.; Dwek, E.; Arendt, R. G.; Basu-Zych, A.; Wiklind, T.; Yukita, M.; Fragos, T.; Hornschemeier, A. E.; Markwardt, L.; Ptak, A.; Tzanavaris, P.

2017-12-01

We present LIGHTNING, a new spectral energy distribution fitting procedure, capable of quickly and reliably recovering star formation history (SFH) and extinction parameters. The SFH is modeled as discrete steps in time. In this work, we assumed lookback times of 0-10 Myr, 10-100 Myr, 0.1-1 Gyr, 1-5 Gyr, and 5-13.6 Gyr. LIGHTNING consists of a fully vectorized inversion algorithm to determine SFH step intensities and combines this with a grid-based approach to determine three extinction parameters. We apply our procedure to the extensive far-UV-to-far-IR photometric data of M51, convolved to a common spatial resolution and pixel scale, and make the resulting maps publicly available. We recover, for M51a, a peak star formation rate (SFR) between 0.1 and 5 Gyr ago, with much lower star formation activity over the past 100 Myr. For M51b, we find a declining SFR toward the present day. In the outskirt regions of M51a, which includes regions between M51a and M51b, we recover an SFR peak between 0.1 and 1 Gyr ago, which corresponds to the effects of the interaction between M51a and M51b. We utilize our results to (1) illustrate how UV+IR hybrid SFR laws vary across M51 and (2) provide first-order estimates for how the IR luminosity per unit stellar mass varies as a function of the stellar age. From the latter result, we find that IR emission from dust heated by stars is not always associated with young stars and that the IR emission from M51b is primarily powered by stars older than 5 Gyr.

Observations spotted solar type stars in Pleiades

International Nuclear Information System (INIS)

Magnitskij, A.K.

1987-01-01

The september - october 1986 observations discovered periodic light variations in three solar type stars in the Pleiades cluster: Hz 296 (0.8 M Sun ), Hz152(0.91 M Sun ) and Hz739(1.15 M Sun ). Periods and amplitudes are accordingly 2 d and 0 m .11, 4 d .12 and 0 m .07, 2 d .70 and 0 m .05. Considerable light variations of these stars in Pleiades are due to the rotation of spotted stars. Contrast spots of solar type stars likely exist when stars are young and rapidly rotate

Van Otlu Peynirinin Yapılışı ve Mikrobiyolojik, Fiziksel ve Kimyasal Nitelikleri

Directory of Open Access Journals (Sweden)

Ahmet Kurt

2015-02-01

Full Text Available Bu araştırmada 10 adet taze Van Otlu peyniri örneklerine; mikrobiyolojik, fiziksel ve kimyasal analizler uygulanmıştır. Peynir teknolojisinde, sağlık, teknik ve ekonomik yönden önemli olan toplam koliform, süt asidi, lipolitik ve proteolitik mikroorganizmalarla maya ve küflerin sayısal değerleri yanında rutubet, yağ, yağsız kurumadde, kurumaddede yağ, protein, suda eriyen protein, kül, tuz, saf kül, kurumaddede tuz ve % asitlik oranları, peynir örneklerinde ayrı ayrı saptanmıştır. Elde edilen sonuçlara göre peynir yapımı çok dağınık ve ilkel karakter arz etmektedir. Peynirlerin yapımındaki farklı uygulamalar, teknik bilgi ve yöntem noksanlığı yüzünden, gerek mikrobiyolojik analiz ve gerekse fiziksel ve kimyasal analiz sonuçları örnekten örneğe önemli fraklılıklar göstermiştir. Peynir örneklerinde saptanan Koliform organizma sayıları, hem sağlık yönünden hem de peynirlerin olgunlaşmalarında sorunlara neden olabilecek düzeydedir.

Variable Stars in the M31 Dwarf Spheroidal Companion Cassiopeia

Science.gov (United States)

Pritzl, Barton J.; Armandroff, T. E.; Jacoby, G. H.; Da Costa, G. S.

2007-12-01

Dwarf spheroidal galaxies show very diverse star formation histories. For the Galactic dwarf spheroidal galaxies, a correlation exists between Galactocentric distance and the prominence of intermediate-age ( 2 - 10 Gyr) populations. To test whether this correlation exists for the M31 dwarf spheroidal galaxies, we observed the Cassiopeia (And VII) dwarf galaxy, which is one of the most distant M31 dwarf spheroidal galaxies. We will present the results of a variable star search using HST/ACS data, along with a preliminary color-magnitude diagram. From the RR Lyrae stars we can obtain an independent distance and metallicity estimate for the dwarf galaxy. These results will be compared to those found for the other M31 dwarf spheroidal galaxies.This research is supported in part by NASA through grant number GO-11081.11 from the Space Telescope Science Institute.

On the feasibility of studying the exospheres of Earth-like exoplanets by Lyman- α monitoring. Detectability constraints for nearby M stars

Science.gov (United States)

Castro, Ana I. Gómez de; Beitia-Antero, Leire; Ustamujic, Sabina

2018-04-01

Observations of the Earth's exosphere have unveiled an extended envelope of hydrogen reaching further than 10 Earth radii composed of atoms orbiting around the Earth. This large envelope increases significantly the opacity of the Earth to Lyman α (Ly α) photons coming from the Sun, to the point of making feasible the detection of the Earth's transit signature from 1.35 pc if pointing with an 8 meter primary mirror space telescope through a clean line of sight ( N H flux variability. We show that, in spite of the interstellar, heliospheric and astrospheric absorption, the transit signature in M5 V type stars would be detectable with a dedicated Ly α flux monitor implemented in a 4-8 m class space telescope. Such monitoring programs would enable measuring the robustness of planetary atmospheres under heavy space weather conditions like those produced by M-type stars. A 2-m class telescope, such as the World Space Observatory, would suffice to detect an Earth-like planet orbiting around Proxima Centauri, if there was such a planet or nearby M5 type stars.

Hot HB Stars in Globular Clusters: Physical Parameters and Consequences for Theory. VI; The Second Parameter Pair M 3 and M 13

Science.gov (United States)

Moehler, S.; Landsman, W. B.; Sweigart, A. V.; Grundahl, F.

2003-01-01

We present the results of spectroscopic analyses of hot horizontal branch (HB) stars in M 13 and M 3, which form a famous "second parameter" pair. F rom the spectra and Stromgren photometry we derived - for the first time in M 13 - atmospheric parameters (effective temperature and surface gravity). For stars with Stromgren temperatures between 10,000 and 12,000 K we found excellent agreement between the atmospheric parameters derived from Stromgren photometry and those derived from Balmer line profile fits. However, for cooler stars there is a disagreement in the parameters derived by the two methods, for which we have no satisfactory explanation. Stars hotter than 12,000 K show evidence for helium depletion and iron enrichment, both in M 3 and M 13. Accounting for the iron enrichment substantially improves the agreement with canonical evolutionary models, although the derived gravities and masses are still somewhat too low. This remaining discrepancy may be an indication that scaled-solar metal-rich model atmospheres do not adequately represent the highly non-solar abundance ratios found in blue HB stars affected by diffusion. We discuss the effects of an enhancement in the envelope helium abundance on the atmospheric parameters of the blue HB stars, as might be caused by deep mixing on the red giant branch or primordial pollution from an earlier generation of intermediate mass asymptotic giant branch stars. Key words. Stars: atmospheres - Stars: evolution - Stars: horizontal branch - Globular clusters: individual: M 3 - Globular clusters: individual: M 13

Infrared (1.4-4.1μm) spectra of Wolf-Rayet stars

International Nuclear Information System (INIS)

Williams, P.M.

1982-01-01

The spectra of a variety of Wolf-Rayet stars have been observed with approximately 1% spectral resolution in the 1.4-4.1μm region using UKIRT. Strong lines due to ions of helium and carbon are observed and their relative strengths discussed. The He I singlet at 2.058μm is anomalously strong relative to other He I lines in WC stars and is responsible for the difference in the (H-K) colours of WN and WC stars. Emission line corrections to H, K and L magnitudes of different types are discussed. The Sanduleak O VI star ST 3 shows very strong C IV lines like the WC5 stars but not the strong He I. (Auth.)

A GLOBAL STAR-FORMING EPISODE IN M31 2–4 GYR AGO

Energy Technology Data Exchange (ETDEWEB)

Williams, Benjamin F.; Dalcanton, Julianne J.; Weisz, Daniel R.; Lewis, Alexia R., E-mail: ben@astro.washington.edu, E-mail: jd@astro.washington.edu, E-mail: dweisz@astro.washington.edu [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); and others

2015-06-10

We have identified a major global enhancement of star formation in the inner M31 disk that occurred between 2–4 Gyr ago, producing ∼60% of the stellar mass formed in the past 5 Gyr. The presence of this episode in the inner disk was discovered by modeling the optical resolved star color–magnitude diagrams of low extinction regions in the main disk of M31 (3 < R < 20 kpc) as part of the Panchromatic Hubble Andromeda Treasury. This measurement confirms and extends recent measurements of a widespread star formation enhancement of similar age in the outer disk, suggesting that this burst was both massive and global. Following the galaxy-wide burst, the star formation rate of M31 has significantly declined. We briefly discuss possible causes for these features of the M31 evolutionary history, including interactions with M32, M33, and/or a merger.

STELLAR DIAMETERS AND TEMPERATURES. II. MAIN-SEQUENCE K- AND M-STARS

Energy Technology Data Exchange (ETDEWEB)

Boyajian, Tabetha S.; McAlister, Harold A.; Jones, Jeremy; White, Russel; Henry, Todd; Gies, Douglas; Jao, Wei-Chun; Parks, J. Robert [Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106 (United States); Von Braun, Kaspar; Kane, Stephen R.; Ciardi, David [NASA Exoplanet Science Institute, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Van Belle, Gerard [Lowell Observatory, Flagstaff, AZ 86001 (United States); Ten Brummelaar, Theo A.; Schaefer, Gail; Sturmann, Laszlo; Sturmann, Judit [The CHARA Array, Mount Wilson Observatory, Mount Wilson, CA 91023 (United States); Muirhead, Philip S. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Lopez-Morales, Mercedes [Institut de Ciencies de L' Espai (CSIC-IEEC), E-08193 Bellaterra (Spain); Ridgway, Stephen [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726-6732 (United States); Rojas-Ayala, Barbara [Department of Astrophysics, Division of Physical Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); and others

2012-10-01

We present interferometric angular diameter measurements of 21 low-mass, K- and M-dwarfs made with the CHARA Array. This sample is enhanced by adding a collection of radius measurements published in the literature to form a total data set of 33 K-M-dwarfs with diameters measured to better than 5%. We use these data in combination with the Hipparcos parallax and new measurements of the star's bolometric flux to compute absolute luminosities, linear radii, and effective temperatures for the stars. We develop empirical relations for {approx}K0 to M4 main-sequence stars that link the stellar temperature, radius, and luminosity to the observed (B - V), (V - R), (V - I), (V - J), (V - H), and (V - K) broadband color index and stellar metallicity [Fe/H]. These relations are valid for metallicities ranging from [Fe/H] = -0.5 to +0.1 dex and are accurate to {approx}2%, {approx}5%, and {approx}4% for temperature, radius, and luminosity, respectively. Our results show that it is necessary to use metallicity-dependent transformations in order to properly convert colors into stellar temperatures, radii, and luminosities. Alternatively, we find no sensitivity to metallicity on relations we construct to the global properties of a star omitting color information, e.g., temperature-radius and temperature-luminosity. Thus, we are able to empirically quantify to what order the star's observed color index is impacted by the stellar iron abundance. In addition to the empirical relations, we also provide a representative look-up table via stellar spectral classifications using this collection of data. Robust examinations of single star temperatures and radii compared to evolutionary model predictions on the luminosity-temperature and luminosity-radius planes reveal that models overestimate the temperatures of stars with surface temperatures <5000 K by {approx}3%, and underestimate the radii of stars with radii <0.7 R{sub Sun} by {approx}5%. These conclusions additionally

Tidal radii of the globular clusters M 5, M 12, M 13, M 15, M 53, NGC 5053 and NGC 5466 from automated star counts.

Science.gov (United States)

Lehmann, I.; Scholz, R.-D.

1997-04-01

We present new tidal radii for seven Galactic globular clusters using the method of automated star counts on Schmidt plates of the Tautenburg, Palomar and UK telescopes. The plates were fully scanned with the APM system in Cambridge (UK). Special account was given to a reliable background subtraction and the correction of crowding effects in the central cluster region. For the latter we used a new kind of crowding correction based on a statistical approach to the distribution of stellar images and the luminosity function of the cluster stars in the uncrowded area. The star counts were correlated with surface brightness profiles of different authors to obtain complete projected density profiles of the globular clusters. Fitting an empirical density law (King 1962) we derived the following structural parameters: tidal radius r_t_, core radius r_c_ and concentration parameter c. In the cases of NGC 5466, M 5, M 12, M 13 and M 15 we found an indication for a tidal tail around these objects (cf. Grillmair et al. 1995).

The Ca II resonance lines in M dwarf stars without H-alpha emission

Energy Technology Data Exchange (ETDEWEB)

Giampapa, M.S.; Cram, L.E.; Wild, W.J. (National Solar Observatory, Tucson, AZ (USA) Sydney Univ. (Australia) Arizona Univ., Tucson (USA))

1989-10-01

Spectra of the Ca II H and K lines in a sample of 31 M dwarf stars without H-alpha emission are used to calculate chromospheric K line radiative losses, F(k), and to study the joint response of Ca II K and H-alpha to chromospheric heating in dwarf M stars. It is suggested that the poor correlation found in the equivalent width - log F(K) diagram may be due either to radial segregation of the H-alpha and K line forming regions or to lateral inhomogeneities in the chromospheres. The results confirm the existence of dM stars with weak H-alpha absorption and K line emission only slightly weaker than that of the dMe stars, and show that dM stars with weak H-alpha but kinematics and metallicities representative of the young disk population belong to a class characterized by a comparatively high degree of chromospheric activity. 32 refs.

Kuramsal ve İşlevsel Dil Öğretiminde Tiyatronun Rolü ve Önemi

Directory of Open Access Journals (Sweden)

Gıyasettin AYTAŞ

2017-10-01

Full Text Available Tiyatro bir sanat faaliyeti olmanın yanında etkili bir iletişim aracıdır. En eski dönemlerden bu yana, hatta insanlığın varlığından itibaren tiyatrodan ve onun etkililiğinden söz etmek olasıdır. Dil edinim süreçleri ile ilgili görüşler birbirinden farklı olmakla birlikte, dilin kullanımında en temel gösterge iletişim ihtiyacıdır. Bununla birlikte dil aynı zamanda bir temsil göstergesidir. Onun aracılığı ile aidiyet ve mensubiyetler hakkında hüküm verilir. Bireyin sosyal ve siyasal özelliklerinin yanında, karakteristik özelliklerini de kullandığı dil aracılığı ile tespit edebilmekteyiz. Tiyatro bu farklılıkların her birini bir arada sergileyen ve somut bir göstergeye dönüştüren bir araç olarak karşımıza çıkmaktadır. Tiyatro yaşanmışlıkları bir araya getirerek iletişim çeşitliliğini ve zenginliğini ortaya koyar. Hayatın hem var olanını hem de olması gerekenlerini birlikte sunar. Her ne kadar bir durum veya olay sonsuz olarak değerlendirilmesi mümkün değilse de tiyatro bu mümkün olmayana varsayımlar açısından yaklaşır. İnsan davranışlarının bilinçli ve bilinçsiz olmak üzere iki göstergesi bulunmaktadır. Bu iki durumla ilgili iletişim yeterliliklerini ve farklılıklarını tiyatro aracılığı ile birlikte görebiliriz. Güzel sanatların hemen tamamını bir arada ve birlikte içinde barındıran tiyatro, bütün dil aşamaların birlikte ve bir arada sunar. Hem iç hem de dış konuşmanın bütün inceliklerini birlikte sunan ve bu özelliği ile karşılıklı ifade çeşitliliğini tiyatro birlikte sunar. İletişim ve dil ediniminde tiyatronun önemini ve gerekliliğini anlamak ve sorgulamak için tiyatronun işlevsel özelliğinden bütün ayrıntıları ile yararlanmak kaçınılmazdır.

The Productivity of Oxygenic Photosynthesis around Cool, M Dwarf Stars

Science.gov (United States)

Lehmer, Owen R.; Catling, David C.; Parenteau, Mary N.; Hoehler, Tori M.

2018-06-01

In the search for life around cool stars, the presence of atmospheric oxygen is a prominent biosignature, as it may indicate oxygenic photosynthesis (OP) on the planetary surface. On Earth, most oxygenic photosynthesizing organisms (OPOs) use photons between 400 and 750 nm, which have sufficient energy to drive the photosynthetic reaction that generates O2 from H2O and CO2. OPOs around cool stars may evolve similar biological machinery capable of producing oxygen from water. However, in the habitable zones (HZs) of the coolest M dwarf stars, the flux of 400–750 nm photons may be just a few percent that of Earth’s. We show that the reduced flux of 400–750 nm photons around M dwarf stars could result in Earth-like planets being growth limited by light, unlike the terrestrial biosphere, which is limited by nutrient availability. We consider stars with photospheric temperatures between 2300 and 4200 K and show that such light-limited worlds could occur at the outer edge of the HZ around TRAPPIST-1-like stars. We find that even if OP can use photons longer than 750 nm, there would still be insufficient energy to sustain the Earth’s extant biosphere throughout the HZ of the coolest stars. This is because such stars emit largely in the infrared and near-infrared, which provide sufficient energy to make the planet habitable, but limits the energy available for OP. TRAPPIST-1f and g may fall into this category. Biospheres on such planets, potentially limited by photon availability, may generate small biogenic signals, which could be difficult for future observations to detect.

Yazılım test süreci ve TMMi modelinde prısma yaklaşımı uygulaması

OpenAIRE

Serdaroğlu, Doğa

2015-01-01

Bu çalışmanın asıl amacı yazılım test süreci için kullanılan TMMi(Test Maturity Model Integration) ve PRISMA(Practical Risk Based Testing) tekniklerinin anlaşılmasıdır. Tez çalışmasına kısa bir giriş yapıldıktan sonra yazılımda kalite ve yazılımda test olguları gözden geçirilmiştir. Sonrasında PRISMA ile olan ilişkisi sebebiyle ISTQB(International Software Testing Qualifications Board) rehber dokümanı özetlenmiştir. Uygulama olarak web tabanlı yeni geliştirilen bir yazılım üzerinde süre...

The Globular Cluster NGC 6402 (M14). II. Variable Stars

DEFF Research Database (Denmark)

Contreras Peña, C.; Catelan, M.; Grundahl, F.

2018-01-01

approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive =0.589 {{d...

EVIDENCE FOR DELAYED MASSIVE STAR FORMATION IN THE M17 PROTO-OB ASSOCIATION

International Nuclear Information System (INIS)

Povich, Matthew S.; Whitney, Barbara A.

2010-01-01

Through analysis of archival images and photometry from the Spitzer GLIMPSE and MIPSGAL surveys combined with Two Micron All Sky Survey and MSX data, we have identified 488 candidate young stellar objects (YSOs) in the giant molecular cloud M17 SWex, which extends ∼50 pc southwest from the prominent Galactic H II region M17. Our sample includes >200 YSOs with masses >3 M sun that will become B-type stars on the main sequence. Extrapolating over the stellar initial mass function (IMF), we find that M17 SWex contains >1.3 x 10 4 young stars, representing a proto-OB association. The YSO mass function is significantly steeper than the Salpeter IMF, and early O stars are conspicuously absent from M17 SWex. Assuming M17 SWex will form an OB association with a Salpeter IMF, these results reveal the combined effects of (1) more rapid circumstellar disk evolution in more massive YSOs and (2) delayed onset of massive star formation.

A RE-EVALUATION OF THE EVOLVED STARS IN THE GLOBULAR CLUSTER M13

International Nuclear Information System (INIS)

Sandquist, Eric L.; Gordon, Mark; Levine, Daniel; Bolte, Michael

2010-01-01

We have analyzed photometry from space- and ground-based cameras to identify all bright red giant branch (RGB), horizontal branch (HB), and asymptotic giant branch (AGB) stars within 10' of the center of the globular cluster M13. We identify a modest (7%) population of HB stars redder than the primary peak (including RR Lyrae variables at the blue end of the instability strip) that is somewhat more concentrated to the cluster core than the rest of the evolved stars. We find support for the idea that they are noticeably evolved and in the late stages of depleting helium in their cores. This resolves a disagreement between distance moduli derived from the tip of the RGB and from stars in or near the RR Lyrae instability strip. We identified disagreements between HB model sets on whether stars with T eff ∼ eff ∼ eff ∼ 22, 000 K) as previously suggested. These stars are brighter than other stars of similar color (either redder or bluer), and may be examples of 'early hot flashers' that ignite core helium fusion shortly after leaving the RGB. We used ultraviolet photometry to identify hot post-HB stars, and based on their numbers (relative to canonical AGB stars) we estimate the position on the HB where the morphology of the post-HB tracks change to I ∼ 17.3, between the two peaks in the HB distribution. Concerning the possibility of helium enrichment in M13, we revisited the helium-sensitive R ratio, applying a new method for correcting star counts for larger lifetimes of hot HB stars. We find that M13's R ratio is in agreement with theoretical values for primordial helium abundance Y P = 0.245 and inconsistent with a helium enhancement ΔY = 0.04. The brightness of the HB (both in comparison to the end of the canonical HB and to the tip of the RGB) also appears to rule out the idea that the envelopes of the reddest HB stars have been significantly enriched in helium. The absolute colors of the turnoffs of M3 and M13 potentially may be used to look for

Mining the HST Treasury: The ASTRAL Reference Spectra for Evolved M Stars

Science.gov (United States)

Carpenter, K. G.; Ayres, T.; Harper, G.; Kober, G.; Wahlgren, G. M.

2012-01-01

The "Advanced Spectral Library (ASTRAL) Project: Cool Stars" (PI = T. Ayres) is an HST Cycle 18 Treasury Program designed to collect a definitive set of representative, high-resolution (R greater than 100,000) and high signal/noise (S/N greater than 100) UV spectra of eight F-M evolved cool stars. These extremely high-quality STIS UV echelle spectra are available from the HST archive and through the University of Colorado (http://casa.colorado.edu/ayres/ASTRAL/) portal and will enable investigations of a broad range of problems -- stellar, interstellar. and beyond -- for many years. In this current paper, we concentrate on producing a roadrnap to the very rich spectra of the two evolved M stars in the sample, the M3.4 giant Gamma Crucis (GaCrux) and the M2Iab supergiant Alpha Orionis (Betelgeuse) and illustrate the huge increase in coverage and quality that these spectra provide over that previously available from IUE and earlier HST observations. These roadmaps will facilitate the study of the spectra, outer atmospheres, and winds of not only these stars. but also numerous other cool, low-gravity stars and make a very interesting comparison to the already-available atlases of the K2III giant Arcturus.

Bir Katı Atık Bertaraf Tesisi için Otomasyon Sistem Tasarımı ve Uygulaması

Directory of Open Access Journals (Sweden)

Murat AYAZ

2014-09-01

Full Text Available Kontrolsüz atık sahalarında çöp depolanması sonucu koku oluşması, haşere üremesi, başıboş hayvanların beslenme ortamının oluşması, çöplerin etrafa yayılması ve yangın riski gibi sebepler bu tür çöp döküm alanlarının kontrol altına alınmasını gerektirmektedir. Bu durum kontrolsüz depolama sahalarının yerine düzenli (kontrollü depolama sahalarının kullanımını zorunlu kılmaktadır. Gerek ülkemizde gerekse de diğer ülkelerde düzenli depolama sahalarının sayısı gün geçtikçe artış göstermektedir. Düzenli depolama sahaları yapısal olarak geniş bir alan üzerine tesis edilmektedir. Geniş yüzey alanına sahip bu tür tesislerde birimler arası iletişim ve kontrol SCADA (Supervisory Control and Data Acquisition sistemi ile gerçekleştirildiğinde, gerçek zamanlı izleme – kontrol, güvenli çalışma, düşük işletme maliyeti, insan iş gücü gereksiniminin azaltılması ve esneklik gibi birçok avantaj sağlamaktadır. Bu çalışmada yaklaşık 225000 m2 üzerine kurulmuş bir katı atık bertaraf tesisinin tüm ünitelerinin kontrolü ve izlenmesi SCADA otomasyonu kullanılarak gerçekleştirilmiştir. Katı atık bertaraf tesisi trafo ve jeneratörün yer aldığı enerji dağıtım noktası, toplanan katı atıkların miktarının ölçüldüğü kantar noktası, atık suyun biriktirildiği atık su havuzu ve pompa istasyonu, çevre aydınlatması kontrol noktası ve tesis içerisinde yer alan bütün bileşenlerin izlendiği idari bina olmak üzere beş ayrı noktadan oluşmaktadır. Tesisin belirtilen bu beş ayrı noktasında PLC (Programmable Logic Controller kontrol panelleri yer almaktadır. Bu noktalar arası haberleşme 1500 metrelik bir profibus hattı ile gerçekleştirilmektedir. İdari bina ile kantar bölgelerinde sistemin izleme ve kontrolünün gerçekleştirilebileceği SCADA merkezi oluşturulmuştur. Bu endüstriyel tesisin otomasyon sisteminin tasarımı ve

Sosyal Medya ve Bazı Kurumsal Etkileşimler ve Sosyal Medyaya Eleştirel Yaklaşım / Some Corporate Social Media and Interaction and Critical Approach to Social Media

OpenAIRE

Cerrah, Lokman

2016-01-01

Bireylerin birbirleriyle yazılı veya görsel olarak iletişim kurmalarını kolaylaştıran sosyal medya farklı inanç, milliyet ve kültürlere sahip insanların diğerlerini tanımalarına ve aynı zamanda kendilerini sorgulamalarına da yol açmıştır. Dolayısıyla sosyal medya birey ve toplumların değişmesine imkân tanımış bununla beraber toplumlarda ki değişimlerin de anlık olarak göz önüne çıkmasını sağlamıştır. Bu gün artık insanlar sosyal medyayı takip ederek dünyayı tanıma, kendini dünyaya anlatma imk...

PLANETS AROUND LOW-MASS STARS (PALMS). IV. THE OUTER ARCHITECTURE OF M DWARF PLANETARY SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Bowler, Brendan P. [California Institute of Technology, Division of Geological and Planetary Sciences, 1200 East California Boulevard, Pasadena, CA 91101 (United States); Liu, Michael C. [Institute for Astronomy, University of Hawai' i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Shkolnik, Evgenya L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Tamura, Motohide, E-mail: bpbowler@caltech.edu [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2015-01-01

We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (≳1 M {sub Jup}) around 122 newly identified nearby (≲40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M {sub ☉}) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M {sub Jup} at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M {sub Jup}; L0{sub −1}{sup +2}; 120 ± 20 AU), GJ 3629 B (64{sub −23}{sup +30} M {sub Jup}; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M {sub Jup}; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M {sub Jup}; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M {sub Jup} planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M {sub Jup} range like those orbiting HR 8799 and β Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M {sub Jup}) companions

Massive stars and the energy balance of the ISM: I. The imapct of an isolated 60 M star

Science.gov (United States)

Yorke, H. W.; Freyer, T.; Hensler, G.

2002-01-01

We present results of numerical simulations carried out with a 2D radiation hydrodynamics code in order to study the impact of massive stars on their surrounding interstellar medium. This first paper deals with the evolution of the circumstellar gas around an isolated 60 M star.

Star counts in M15 on U, B and V plates

Energy Technology Data Exchange (ETDEWEB)

Calvani, M [Padua Univ. (Italy). Ist. di Astronomia; Nobili, L [Padua Univ. (Italy). Ist. di Fisica; Turolla, R [Scuola Internazionale Superiore di Studi Avanzati, Trieste (Italy)

1980-11-01

We present new counts of stars in M15, using plates in B, V and U. We are able to explore relatively close to the central parts of the cluster (0.1 pc) and we derive the best fitting parameters for the star distribution.

A Hard X-Ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

DEFF Research Database (Denmark)

Yukita, M.; Hornschemeier, A. E.; Lehmer, B. D.

2016-01-01

We present the results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d = 4.6 Mpc). This is the first investigation to spatially resolve the hard (E > 10 keV) X-ray emission of this galaxy. The nuclear region and similar to 20 off-nuclear point sources......, including a previously discovered ultraluminous X-ray source, are detected in our NuSTAR observations. The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most...

Larinks kanserli hastalarda serum CA 72-4, CA 19-9, CEA ve kombine tümör marker seviyelerinin karşılaştırılması ve prognostik değerleri

OpenAIRE

Altaş, Enver; Kızıltunç, Ahmet; Karaşen, R.Murat; Öztürk, Aziz; Sütbeyaz, Yavuz; Gündoğdu, Cemal

2009-01-01

SüleymanDemirel Üniversitesi TIP FAKÜLTESİ DERGİSİ: 1997 Haziran; 4(3) Larinks kanserli hastalarda serum CA 72-4, CA 19-9, CEA ve kombine tümör marker seviyelerinin karşılaştırılması ve prognostik değerleri Enver Altaş Ahmet Kızıltunç R. Murat Karaşen Aziz Öztürk Yavuz Sütbeyaz Cemal Gündoğdu ÖzetLarinks kanserli hastaların tedavi etkinliklerinin takibinde çeşitli klinik ve laboratuvar tetkikleri kullanılmaktadır. Tümör markerleri de bu tetkiklerden birisidir. Ancak, CA 19-9 (Carbohydr...

Kelîle Ve Dimne Hikâyelerinin Yaratımı Ve Aktarımı: Pança Tantra’dan Hümâyûn-Nâme’ye

Directory of Open Access Journals (Sweden)

Tuncay BÜLBÜL

2017-12-01

Full Text Available İnsan topluluklarının birlikteliğini tesis eden unsur şüphesiz ki kültürdür. Kültür, insanların konuşmadan giyime, yeme içme alışkanlıklarından “doğru” “yanlış” algılarına kadar hayatın her aşamasını etkileyen temel unsurdur. İnsan hayatı için bu kadar vazgeçilmez olan kültürün gelecek nesillere aktarılmasında kullanılan en önemli araç sözdür. Bu aracın kültür atmosferi içerisinde oluşturduğu ortam da “sözlü kültür ortamı”dır. Sahip oldukları kültürel unsurları gelecek nesillere aktarma kaygısını taşıyan insanoğlu sözlü kültür ortamını oluşturmuş, bu ortam içerisinde ürettiği/yarattığı ürünlerin farklı formlarla kalıcılığını sağlamıştır. Sözlü kültür ortamında üretilen/yaratılan ürünler yazının gündelik hayatın içine girmesiyle yazıya geçirilmeye başlamışlardır. Yazıya geçirilen sözlü kültür unsurları her ne kadar dinamik yapılarını kaybetse de aktarılma eylemi devam ettiği için yeniden yazıldığı her dönemin ve toplumun izlerini bünyesine katmıştır. Bu durum özellikle başka bir kültür ortamında üretilen ürünlerin farklı kültür coğrafyalarına aktarımı ya da adaptosyonu sırasında çok sık görülmektedir. Çünkü bir ürünü bünyesine katan kültür, ona kaçınılmaz olarak kendinden unsurlar katar. Hint sözlü kültür ortamında üretilen/yaratılan Pança Tantra anlatmaları dünyayı çepeçevre dolaşmış, girdiği her kültür ortamından bünyesine bir şeyler katmıştır. Pança Tantra anlatmalarının özellikle İbnü’l-Mukaffa tarafından tarafından Pehlevîceden Arapçaya tercümesi sırasında önemli değişikliklere uğradığı görülmektedir. İbnü’l-Mukaffa tercüme sırasında anlatmaların orijinalinde bulunmayan yeni bölümler ve yeni hikâyeleri eserine eklemiş, ona yeni bir çehre kazandırmış, hatta bu tercümeden sonra Pança Tantra anlatmalar

Neutron star formation in theoretical supernovae. Low mass stars and white dwarfs

International Nuclear Information System (INIS)

Nomoto, K.

1986-01-01

The presupernova evolution of stars that form semi-degenerate or strongly degenerate O + Ne + Mg cores is discussed. For the 10 to 13 Msub solar stars, behavior of off-center neon flashes is crucial. The 8 to 10 m/sub solar stars do not ignite neon and eventually collapse due to electron captures. Properties of supernova explosions and neutron stars expected from these low mass progenitors are compared with the Crab nebula. The conditions for which neutron stars form from accretion-induced collapse of white dwarfs in clsoe binary systems is also examined

Dünyada Açlık Olgusu ve Çözüm Arayışları

Directory of Open Access Journals (Sweden)

Aziz Ekşi

2015-02-01

Full Text Available Gıda güvencesizliği çağımızın en önemli sorunlarından biridir. Öyle ki dünyada yaşayan 7 insandan 1’i açtır. Daha da kötüsü, gıda üretiminin yeterli olmasına karşılık açlığın yıldan yıla azalmamasıdır. Bunun başlıca nedeni gıda üretimindeki ve tüketimindeki bölgesel farklılıktır. Gelirden aldığı pay daha düşük olduğu için global güneyde açlık daha yaygındır. Fiyat dalgalanmaları ile aç insan sayısı arasında gerçekçi bir ilişki kurulması zordur. Yüksek fiyat kısa vadede yoksulların gıdaya ulaşmasını engellese bile uzun vadede sürdürülebilir çiftçiliğin ve gıda güvencesinin başlıca aracıdır. Açlığın çözümü için önerilen batı yaklaşımı, gıda adaleti, gıda egemenliği, bölgesel oluşum, gıda yardımı gibi yaklaşımların olumlu ve olumsuz yanları vardır. Bu nedenle, bölge, nüfus ve zaman bağlamında yaygın üretim odaklı yeni bir yaklaşım gereklidir.

Hot HB Stars in Globular Clusters - Physical Parameters and Consequences for Theory. VI. The Second Parameter Pair M3 and M13

Science.gov (United States)

Moehler, S.; Landsman, W. B.; Sweigart, A. V.; Grundahl, F.

2002-01-01

We present the results of spectroscopic analyses of hot horizontal branch (HB) stars in M13 and M3, which form a famous second parameter pair. From the spectra we derived - for the first time in M13 - atmospheric parameters (effective temperature and surface gravity) as well as abundances of helium, magnesium, and iron. Consistent with analyses of hot HB stars in other globular clusters we find evidence for helium depletion and iron enrichment in stars hotter than about 12,000 K in both M3 and M13. Accounting for the iron enrichment substantially improves the agreement with canonical evolutionary models, although the derived gravities and masses are still somewhat too low. This remaining discrepancy may be an indication that scaled-solar metal-rich model atmospheres do not adequately represent the highly non-solar abundance ratios found in blue HB stars with radiative levitation. We discuss the effects of an enhancement in the envelope helium abundance on the atmospheric parameters of the blue HB stars, as might be caused by deep mixing on the red giant branch or primordial pollution from an earlier generation of intermediate mass asymptotic giant branch stars.

Diabetik Ayak Sağaltımında Vakum Destekli Kapama (VAC) Metodu ve Debridmanın Birlikte Etkinliği

OpenAIRE

Fırat, Cemal; Aytekin, Ahmet Hamdi; Fırat, Serkan ErbaturCemal; Aytekin, Ahmet Hamdi; Erbatur, Serkan

2015-01-01

Amaç: Diabetik ayak ülserleri periferik nöropati, vasküler yetmezlik ve immün sistem bozukluklarından oluşan kısır döngünün sonucu olup enfeksiyon ve doku kayıplarına neden olmaktadır. Bu yıkıcı süreç cerrahi onarım seçeneklerini oldukça kısıtlamakta ve greftle onarım seçeneğini öne çıkarmaktadır. Greftlerin başarısı enfeksiyondan arındırılmış yeterli granülasyon dokusunun varlığına bağlıdır. Vakum yardımlı yara kapama sistemi (VAC) tedavisi bu iki etkiyi aynı anda sağlamada oldukça etkili ve...

Damlatma ve Yayma Kültürel Sayım Yöntemlerinin Kıyaslanması Üzerine bir Araştırma

Directory of Open Access Journals (Sweden)

A. Kadir Halkman

2015-02-01

Full Text Available Bu çalışmada 6 adet saf laktik asit bakterisinde yayma, damlatma ve en muhtemel sayı yöntemleri ile, 7 adet kaşar peyniri örneğinde yayma ve damlatma yöntemleri ile toplam streptokok, toplam laktobasil, toplam mesofil aerob, maya-küf ve basil sayılmıştır. Saf laktik asit bakterilerinin sayımında EMS yöntemi katı besiyerinde yapılan sayımlara göre çok farklı değerler vermiştir. Laktik asit bakterilerinin sayımında ve kaşar peynirlerinde yapılan mikroorganizma sayımlarında damlatma ve yayma yöntemleri arasında yüksek benzerlik bulunmuştur. Maliyet unsuru dikkate alınarak rutin testlerde damlatma yönteminin yayma yöntemi yerini alması önerilebilir. Bununla beraber damlatma yöntemindeki sakıncaların gözönüne alınması gerekir.

Infrared spectroscopy of four carbon stars with 9.8 micron emission from silicate grains

International Nuclear Information System (INIS)

Lambert, D.L.; Smith, V.V.; Hinkle, K.H.

1990-01-01

High-resolution K band and low resolution 4 micron spectra were obtained for four carbon stars showing IR emission by silicate grains. The results of the analysis of the K band spectra show that they are J-type stars. These results, together with published spectral classifications, show that all known carbon stars with a silicate emission feature are J-type stars. The 4 micron spectra are very similar to the spectra of classical J-type carbon stars, and do not show SiO bands that might come from a M giant companion. A binary model with a luminous M giant companion as a source of the silicate grain is rejected. It is proposed that the silicate grains formed from gas ejecta at or before the He-core flash, and that the flash initiates severe mixing, leading to the star's conversion to a J-type carbon star. The ejecta are stored in an accretion disk around a low mass unevolved companion. If it can be shown that the hypothesized accretion disk is stable and may be heated adequately, this binary model appears to account for these peculiar carbon stars. 41 refs

TÜRK HAZIR GİYİM SANAYİNDE M. PORTER'IN JENERİK STRATEJİLERİNİN KULLANIMI VE FİRMALAR İÇİN STRATEJİ ÖNERİLERİ

OpenAIRE

AKÇAGÜN, Engin; DAL, Vedat

2014-01-01

Bu çalışmanın amacı başarılı hazır giyim firmalarında M. Porter’ın jenerik stratejilerinin kullanımını analiz etmek ve Türk hazır giyim firmalarının uluslararası pazarlarda üstünlük sağlanmaları için strateji önerileri geliştirmektir. Bu amaç doğrultusunda veri toplamak için literatürdeki kaynaklar yoluyla bir anket geliştirilmiştir ve İstanbul Sanayi Odası tarafından her yıl belirlenen İlk ve İkinci 500 Büyük Sanayi Kuruluşu listesinde bulunan hazır giyim firmalarının rekabet stratejileri an...

HATTAT MUSTAFA HALİM ÖZYAZICI ve TUTTUĞU TALEBE KAYIT DEFTERLERİ

OpenAIRE

Berk, süleyman

2015-01-01

ÖZETOsmanlı’dan Cumhuriyet dönemine intikal eden önemli hattatlarımızdan biri de Mustafa HalimÖzyazıcı’dır (1315/1898- 1384/1964). Halim Efendi, hat sanatının zirveye çıktığı dönemde ünlü sanatkârlardanders almıştır. Sanat bakımından, “Kalemi kendine esir etmiş ve yazıyı yenmiş” kudretli hattatlarımızdanbirisidir. Her çeşit yazıda mükemmel eserler vermiştir. Kendisinin klasik anlamda icazetiolmamasına rağmen mezun olduğu Medresetü’l-Hattâtîn’den aldığı diplomada ders aldığı hocalarınınimzası ...

The POINT-AGAPE Survey I: The Variable Stars in M31

CERN Document Server

An Jun Hong; Hewett, P C; Baillon, Paul; Calchi-Novati, S; Carr, B J; Creze, M; Giraud-Héraud, Yannick; Gould, A; Jetzer, P; Kaplan, J; Kerins, E; Paulin-Henriksson, S; Smartt, S J; Stalin, C S; Tsapras, Y; An, Jin H.; Jetzer, Ph.

2004-01-01

The POINT-AGAPE collaboration has been monitoring M31 for three seasons with the Wide Field Camera on the Isaac Newton Telescope. In each season, data are taken for one hour per night for roughly sixty nights during the six months that M31 is visible. The two fields of view straddle the central bulge, northwards and southwards. We have calculated the locations, periods and amplitudes of 35414 variable stars in M31 as a by-product of our microlensing search. The variables are classified according to their period and amplitude of variation. They are classified into population I and II Cepheids, Miras and semi-regular long-period variables. The population I Cepheids are associated with the spiral arms, while the central concentration of the Miras and long-period variables varies noticeably, the stars with brighter (and shorter) variations being much more centrally concentrated. A crucial role in the microlensing experiment is played by the asymmetry signal. It was initially assumed that the variable stars would ...

SPITZER IRS SPECTRA OF LUMINOUS 8 μm SOURCES IN THE LARGE MAGELLANIC CLOUD: TESTING COLOR-BASED CLASSIFICATIONS

International Nuclear Information System (INIS)

Buchanan, Catherine L.; Kastner, Joel H.; Hrivnak, Bruce J.; Sahai, Raghvendra

2009-01-01

We present archival Spitzer Infrared Spectrograph (IRS) spectra of 19 luminous 8 μm selected sources in the Large Magellanic Cloud (LMC). The object classes derived from these spectra and from an additional 24 spectra in the literature are compared with classifications based on Two Micron All Sky Survey (2MASS)/MSX (J, H, K, and 8 μm) colors in order to test the 'JHK8' (Kastner et al.) classification scheme. The IRS spectra confirm the classifications of 22 of the 31 sources that can be classified under the JHK8 system. The spectroscopic classification of 12 objects that were unclassifiable in the JHK8 scheme allow us to characterize regions of the color-color diagrams that previously lacked spectroscopic verification, enabling refinements to the JHK8 classification system. The results of these new classifications are consistent with previous results concerning the identification of the most infrared-luminous objects in the LMC. In particular, while the IRS spectra reveal several new examples of asymptotic giant branch (AGB) stars with O-rich envelopes, such objects are still far outnumbered by carbon stars (C-rich AGB stars). We show that Spitzer IRAC/MIPS color-color diagrams provide improved discrimination between red supergiants and oxygen-rich and carbon-rich AGB stars relative to those based on 2MASS/MSX colors. These diagrams will enable the most luminous IR sources in Local Group galaxies to be classified with high confidence based on their Spitzer colors. Such characterizations of stellar populations will continue to be possible during Spitzer's warm mission through the use of IRAC [3.6]-[4.5] and 2MASS colors.

The close binary frequency of Wolf-Rayet stars as a function of metallicity in M31 and M33

Energy Technology Data Exchange (ETDEWEB)

Neugent, Kathryn F.; Massey, Philip, E-mail: kneugent@lowell.edu, E-mail: phil.massey@lowell.edu [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

2014-07-01

Massive star evolutionary models generally predict the correct ratio of WC-type and WN-type Wolf-Rayet stars at low metallicities, but underestimate the ratio at higher (solar and above) metallicities. One possible explanation for this failure is perhaps single-star models are not sufficient and Roche-lobe overflow in close binaries is necessary to produce the 'extra' WC stars at higher metallicities. However, this would require the frequency of close massive binaries to be metallicity dependent. Here we test this hypothesis by searching for close Wolf-Rayet binaries in the high metallicity environments of M31 and the center of M33 as well as in the lower metallicity environments of the middle and outer regions of M33. After identifying ∼100 Wolf-Rayet binaries based on radial velocity variations, we conclude that the close binary frequency of Wolf-Rayets is not metallicity dependent and thus other factors must be responsible for the overabundance of WC stars at high metallicities. However, our initial identifications and observations of these close binaries have already been put to good use as we are currently observing additional epochs for eventual orbit and mass determinations.

CCD Photometry Using Multiple Comparison Stars

Directory of Open Access Journals (Sweden)

Yonggi Kim

2004-09-01

Full Text Available The accuracy of CCD observations obtained at the Korean 1.8 m telescope has been studied. Seventeen comparison stars in the vicinity of the cataclysmic variable BG CMi have been measured. The ``artificial" star has been used instead of the ``control" star, what made possible to increase accuracy estimates by a factor of 1.3-2.1 times for ``good" and ``cloudy" nights, respectively. The algorithm of iterative determination of accuracy and weights of few comparison stars contributing to the artificial star, has been presented. The accuracy estimates for 13-mag stars are around 0.002 m mag for exposure times of 30 sec.

THE AVERAGE STAR FORMATION HISTORIES OF GALAXIES IN DARK MATTER HALOS FROM z = 0-8

International Nuclear Information System (INIS)

Behroozi, Peter S.; Wechsler, Risa H.; Conroy, Charlie

2013-01-01

We present a robust method to constrain average galaxy star formation rates (SFRs), star formation histories (SFHs), and the intracluster light (ICL) as a function of halo mass. Our results are consistent with observed galaxy stellar mass functions, specific star formation rates (SSFRs), and cosmic star formation rates (CSFRs) from z = 0 to z = 8. We consider the effects of a wide range of uncertainties on our results, including those affecting stellar masses, SFRs, and the halo mass function at the heart of our analysis. As they are relevant to our method, we also present new calibrations of the dark matter halo mass function, halo mass accretion histories, and halo-subhalo merger rates out to z = 8. We also provide new compilations of CSFRs and SSFRs; more recent measurements are now consistent with the buildup of the cosmic stellar mass density at all redshifts. Implications of our work include: halos near 10 12 M ☉ are the most efficient at forming stars at all redshifts, the baryon conversion efficiency of massive halos drops markedly after z ∼ 2.5 (consistent with theories of cold-mode accretion), the ICL for massive galaxies is expected to be significant out to at least z ∼ 1-1.5, and dwarf galaxies at low redshifts have higher stellar mass to halo mass ratios than previous expectations and form later than in most theoretical models. Finally, we provide new fitting formulae for SFHs that are more accurate than the standard declining tau model. Our approach places a wide variety of observations relating to the SFH of galaxies into a self-consistent framework based on the modern understanding of structure formation in ΛCDM. Constraints on the stellar mass-halo mass relationship and SFRs are available for download online.

The Average Star Formation Histories of Galaxies in Dark Matter Halos from z = 0-8

Science.gov (United States)

Behroozi, Peter S.; Wechsler, Risa H.; Conroy, Charlie

2013-06-01

We present a robust method to constrain average galaxy star formation rates (SFRs), star formation histories (SFHs), and the intracluster light (ICL) as a function of halo mass. Our results are consistent with observed galaxy stellar mass functions, specific star formation rates (SSFRs), and cosmic star formation rates (CSFRs) from z = 0 to z = 8. We consider the effects of a wide range of uncertainties on our results, including those affecting stellar masses, SFRs, and the halo mass function at the heart of our analysis. As they are relevant to our method, we also present new calibrations of the dark matter halo mass function, halo mass accretion histories, and halo-subhalo merger rates out to z = 8. We also provide new compilations of CSFRs and SSFRs; more recent measurements are now consistent with the buildup of the cosmic stellar mass density at all redshifts. Implications of our work include: halos near 1012 M ⊙ are the most efficient at forming stars at all redshifts, the baryon conversion efficiency of massive halos drops markedly after z ~ 2.5 (consistent with theories of cold-mode accretion), the ICL for massive galaxies is expected to be significant out to at least z ~ 1-1.5, and dwarf galaxies at low redshifts have higher stellar mass to halo mass ratios than previous expectations and form later than in most theoretical models. Finally, we provide new fitting formulae for SFHs that are more accurate than the standard declining tau model. Our approach places a wide variety of observations relating to the SFH of galaxies into a self-consistent framework based on the modern understanding of structure formation in ΛCDM. Constraints on the stellar mass-halo mass relationship and SFRs are available for download online.

Rizâeddin b. Fahreddin ve Kütüb-i Sitte ve Müellifleri adlı eseri

OpenAIRE

KHAZİEV, Rinat

2015-01-01

Tez bir Girişten ve üç bölümden oluşmaktadır. Girişte tezin içerdiği bilgiler ve hazırlanmasında izlenen yöntem hakkında bilgiler verilmiştir.Tezin birinci bölümünde Rizâeddin b. Fahreddin’in hayatına dair bilgiler sunulmuştur. Onun şahsiyeti, âlimliği, başmuharrirliği ve sosyal faaliyetleri gösterilmiştir. Diğer taraftan da onun hayatı, ilmi tahsili, hocaları ve eserleri ele alınmıştır.Araştırmanın ikinci bölümde Rizâeddin b. Fahreddin’n Hadis ilmine bakışı ve yaklaşımı tahlil edilm...

Tom Stoppard'ın Rosencrantz ve Guildenstern Öldüler Adlı Oyununda Mizah ve Kader

OpenAIRE

Erkan, Ayça Ülker

2016-01-01

Bu çalışmanın amacı karakterlerin kimlik arayışından kaynaklanan fiziksel mizahı tartışmak ve oyundaki ölüm/şans/kader/gerçeklik/yanılsama gibi temaların Rosencrantz ve Guildenstern’nin varoluşçu hayatlarında nasıl işlediğini göstermektir. Mizah, bu trajikomedinin analiz edilmesinde önemli bir rol oynar. Absürd Tiyatro, insanlık durumundaki saçmalığı ifade eder, rasyonel aygıtların kullanımını terk eder, insanın trajik kaybolmuşluk duygusunu yansıtır ve insanlık durumu olan hayat ve ölümle il...

Üst havayolları için mür tentürü, nane yağı ve mentol kombinasyonu içeren bir pastil

OpenAIRE

Öktemer, Tuğba; İpçi, Kağan; Bayar Muluk, Nuray; Cingi, Cemal

2016-01-01

Mür ve boraks içerek tentürler gargara solüsyonu olarak kullanılmaktadır. Mür sakızı, sindirim güçlüğü, ülserler, soğuk algınlığı, öksürük, astım, akciğer konjesyonu, artrit ağrısı ve kanser için de kullanılır. Mür, ağrıya tabi tutulan farelerde, ağrı kesici etkiler göstermiştir. Antiseptik olarak ağız ve boğaz inşamatuar lezyonlarında kullanılır. Boğaz ve ağzın iltihaplı lezyonlara uygulanır ve antispazmodik olarak kanser ve enfeksiyon hastalıklarının tedavisi için kullanılır. Bu yazıda mür ...

Farklı Hayvan Türlerine Ait Karkas Etlerinin ve Mekanik Sıyrılmış Etlerin, Kimyasal Yapılarına ve SDS-PAGE Yardımıyla Saptanan Protein Profillerine Göre Belirlenmesi

Directory of Open Access Journals (Sweden)

Ayça Yaralı

2015-02-01

Full Text Available Bu çalışmada farklı hayvan karkas etleri ve farklı mekanik sıyrılmış etlerinin kimyasal bileşimi, atomik absorbsiyon spektrofotometresi ile mineral madde bileşimi ve SDS­PAGE ile protein bant dizilimi incelenmiştir. Bu yöntemler ile tür ayrımı ve MDM ayrımı yapılmıştır. Özellikle MDM örneklerinin protein, yağ ve kalsiyum içerikleri diğer karkas etlerinden önemli ölçüde farklı olarak bulunmuştur. Karkas örneklerinin sodyum miktarının MDM örnekleriyle karşılaştırıldığında yüksek olduğu gözlenmiştir. Ayrıca, deneye tabi tutulan makro elementler içinde magnezyum içeriğinin düşük değerlerde olduğu gözlenmiştir. SDS­PAGE bant diziliminde myofibriler proteinler ve sarkoplazmik proteinler incelenmiştir. Elektoroforez jellerinin görüntü analizi ve nicel analizi için densitometre cihazı (The Imager BL, Biolab UviTec software kullanılmıştır.

MÜZİKTE İNSAN SESİ ÜRETİM MODELLERİ VE İŞLEME TEKNOLOJİLERİ ÜZERİNE BİR İNCELEME: TINI ÜRETİM MODELLERİNDEN MÜZİKSEL DOĞRULMAYA GEÇİŞ

OpenAIRE

IŞIKHAN, Cihan

2008-01-01

Tarihsel süreçte insan sesinin müzikle olan birleşimi, teknolojik açıdan da aynı çizgide bir gelişim süreci izler. İlk olarak konuşma sesi ve hemen ardından şarkı sesi üretim modelleri yaratılır ve bu modeller, müzikte tını üretim kaynağı olarak kullanılabilir bir serüvenin başlangıcını oluşturur. Ancak, kültürel bir birikim olarak ortaya çıkan toplumsal müzik kültürü ve dolayısıyla müzik, insan sesi üretimi ve işleme sırasında teknolojik olanaklarla birleştiğinde kuralcı bir zemine oturma e...

Ortaokul 5. ve 6. Sınıf Fen Bilimleri Öğretim Programının Kazanım ve İçerik İlişkisinin Değerlendirilmesi

OpenAIRE

Ocak, Gürbüz; Kutlu Kalender, M. Damla

2018-01-01

Bu çalışma Milli Eğitim Bakanlığı tarafından basılmış 5. ve 6. Sınıf Fen Bilimleri ders kitaplarındaki içeriğin, ortaokul 5. ve 6. Sınıf Fen Bilimleri dersi öğretim programındaki kazanımlara uygunluk düzeyini değerlendirmeyi amaçlamıştır. Öncelikle 2015-2016 eğitim öğretim yılı 5. ve 6.sınıf öğretim programındaki kazanımlarla 5.ve 6. sınıf fen bilimleri ders kitaplarındaki içerikler incelenmiştir. Değerlendirme için ölçme aracı olarak kazanım-içerik değerlendirme rubriği hazırlanmıştır. Geliş...

High-resolution spectra of stars in globular clusters. VI - Oxygen-deficient red giant stars in M13

International Nuclear Information System (INIS)

Brown, J.A.; Wallerstein, G.; Oke, J.B.

1991-01-01

From high-resolution, high signal-to-noise spectra, abundances of carbon, nitrogen, and oxygen and the C-12/C-13 ratio for five red giants in M13, including star II-67, which has previously been reported to be deficient in oxygen have been determined. Three of the five stars exhibit substantial oxygen deficiencies; O/Fe values range from +0.5 to less than about 0.3. The sum of the CNO nuclides is the same for all stars, which is interpreted as evidence that mixing of CNO-cycled material into the envelope is the cause of the variations in oxygen abundance. 41 refs

STAR FORMATION RATES AND STELLAR MASSES OF z = 7-8 GALAXIES FROM IRAC OBSERVATIONS OF THE WFC3/IR EARLY RELEASE SCIENCE AND THE HUDF FIELDS

International Nuclear Information System (INIS)

Labbe, I.; Gonzalez, V.; Bouwens, R. J.; Illingworth, G. D.; Magee, D.; Franx, M.; Trenti, M.; Oesch, P. A.; Carollo, C. M.; Van Dokkum, P. G.; Stiavelli, M.; Kriek, M.

2010-01-01

We investigate the Spitzer/IRAC properties of 36 z ∼ 7 z 850 -dropout galaxies and three z ∼ 8 Y 098 galaxies derived from deep/wide-area WFC3/IR data of the Early Release Science, the ultradeep HUDF09, and wide-area NICMOS data. We fit stellar population synthesis models to the spectral energy distributions to derive mean redshifts, stellar masses, and ages. The z ∼ 7 galaxies are best characterized by substantial ages (>100 Myr) and M/L V ∼ 0.2. The main trend with decreasing luminosity is that of bluing of the far-UV slope from β ∼ -2.0 to β ∼ -3.0. This can be explained by decreasing metallicity, except for the lowest luminosity galaxies (0.1L* z =3 ), where low metallicity and smooth star formation histories (SFHs) fail to match the blue far-UV and moderately red H - [3.6] color. Such colors may require episodic SFHs with short periods of activity and quiescence ('on-off' cycles) and/or a contribution from emission lines. The stellar mass of our sample of z ∼ 7 star-forming galaxies correlates with star formation rate (SFR) according to log M* = 8.70(±0.09) + 1.06(±0.10)log SFR, implying that star formation may have commenced at z > 10. No galaxies are found with SFRs much higher or lower than the past averaged SFR suggesting that the typical star formation timescales are probably a substantial fraction of the Hubble time. We report the first IRAC detection of Y 098 -dropout galaxies at z ∼ 8. The average rest-frame U - V ∼ 0.3 (AB) of the three galaxies are similar to faint z ∼ 7 galaxies, implying similar M/L. The stellar mass density to M UV,AB +0.7 -1.0 x 10 6 M sun Mpc -3 , following log ρ*(z) = 10.6(±0.6) - 4.4(±0.7) log(1 + z) [M sun Mpc -3 ] over 3 < z < 8.

Chromospheric and Transition Region Emission Properties of G, K, and M dwarf Exoplanet Host Stars

Science.gov (United States)

France, Kevin; Arulanantham, Nicole; Fossati, Luca; Lanza, A. F.; Linsky, Jeffrey L.; Redfield, Seth; Loyd, Robert; Schneider, Christian

2018-01-01

Exoplanet magnetic fields have proven notoriously hard to detect, despite theoretical predictions of substantial magnetic field strengths on close-in extrasolar giant planets. It has been suggested that stellar and planetary magnetic field interactions can manifest as enhanced stellar activity relative to nominal age-rotation-activity relationships for main sequence stars or enhanced activity on stars hosting short-period massive planets. In a recent study of M and K dwarf exoplanet host stars, we demonstrated a significant correlation between the relative luminosity in high-temperature stellar emission lines (L(ion)/L_Bol) and the “star-planet interaction strength”, M_plan/a_plan. Here, we expand on that work with a survey of G, K, and M dwarf exoplanet host stars obtained in two recent far-ultraviolet spectroscopic programs with the Hubble Space Telescope. We have measured the relative luminosities of stellar lines C II, Si III, Si IV, and N V (formation temperatures from 30,000 – 150,000 K) in a sample of ~60 exoplanet host stars and an additional ~40 dwarf stars without known planets. We present results on star-planet interaction signals as a function of spectral type and line formation temperature, as well as a statistical comparison of stars with and without planets.

Chemical Abundances of Red Giant Stars in the Globular Cluster M107 (NGC 6171)

Science.gov (United States)

O'Connell, Julia E.; Johnson, Christian I.; Pilachowski, Catherine A.; Burks, Geoffrey

2011-10-01

We present chemical abundances of Al and several Fe-Peak and neutron-capture elements for 13 red giant branch stars in the Galactic globular cluster NGC 6171 (M107). The abundances were determined using equivalent width and spectrum synthesis analyses of moderate-resolution ( R ˜ 15,000), moderate signal-to-noise ratio ( ˜ 80) spectra obtained with the WIYN telescope and Hydra multifiber spectrograph. A comparison between photometric and spectroscopic effective temperature estimates seems to indicate that a reddening value of E(B - V) = 0.46 may be more appropriate for this cluster than the more commonly used value of E(B - V) = 0.33. Similarly, we found that a distance modulus of (m - M)V ≈ 13.7 provided reasonable surface gravity estimates for the stars in our sample. Our spectroscopic analysis finds M107 to be moderately metal-poor with = -0.93 and also exhibits a small star-to-star metallicity dispersion (σ = 0.04). These results are consistent with previous photometric and spectroscopic studies. Aluminum appears to be moderately enhanced in all program stars ( = +0.39, σ = 0.11). The relatively small star-to-star scatter in [Al/Fe] differs from the trend found in more metal-poor globular clusters, and is more similar to what is found in clusters with [Fe/H] ≳ -1. The cluster also appears to be moderately r-process-enriched with = +0.32 (σ = 0.17).

Kedi ve Köpeklerde Diabetes Mellitus.

OpenAIRE

ŞİMŞEK, Aynur; İÇEN, Hasan

2008-01-01

Diabetes mellitus polidipsi, poliüri ve polifaji gibi klinik bulgularla karakterize endokrin bir hastalıktır. Bu derlemede, kedi ve köpeklerde yaygın olan hastalığın etiyoloji, patogenezis, kliniklaboratuar bulguları, tanı, ayırıcı tanı ve sağaltımına yönelik bilgilerin verilmesi amaçlanmıştır

Hastanede takipli gebelerin yenidoğan bakımı ile ilgili bilgi düzeyleri ve etkileyen faktörler

OpenAIRE

Önsüz, Muhammet Fatih; Köse, Onur Özlem; Demir, Figen

2014-01-01

AMAÇ: Bu araştırmada bir hastanenin obstetrik polikliniğinde takip edilen gebelerin yenidoğan bakımı konusundaki bilgi düzeylerinin ve etkileyen faktörlerin belirlenmesi amaçlanmıştı. GEREÇ VE YÖNTEMLER: Tanımlayıcı tipteki bu araştırma bir hastanenin Obstetrik Polikliniği’nde takipli ve araştırmaya katılmayı kabul eden 118 gebe ile yürütüldü. Araştırmanın verileri 23 soru ve iki bölümden oluşan anket formunun yüzyüze gözlem altında uygulanması yoluyla toplandı. Verilerin is...

Computing Models of M-type Host Stars and their Panchromatic Spectral Output

Science.gov (United States)

Linsky, Jeffrey; Tilipman, Dennis; France, Kevin

2018-06-01

We have begun a program of computing state-of-the-art model atmospheres from the photospheres to the coronae of M stars that are the host stars of known exoplanets. For each model we are computing the emergent radiation at all wavelengths that are critical for assessingphotochemistry and mass-loss from exoplanet atmospheres. In particular, we are computing the stellar extreme ultraviolet radiation that drives hydrodynamic mass loss from exoplanet atmospheres and is essential for determing whether an exoplanet is habitable. The model atmospheres are computed with the SSRPM radiative transfer/statistical equilibrium code developed by Dr. Juan Fontenla. The code solves for the non-LTE statistical equilibrium populations of 18,538 levels of 52 atomic and ion species and computes the radiation from all species (435,986 spectral lines) and about 20,000,000 spectral lines of 20 diatomic species.The first model computed in this program was for the modestly active M1.5 V star GJ 832 by Fontenla et al. (ApJ 830, 152 (2016)). We will report on a preliminary model for the more active M5 V star GJ 876 and compare this model and its emergent spectrum with GJ 832. In the future, we will compute and intercompare semi-empirical models and spectra for all of the stars observed with the HST MUSCLES Treasury Survey, the Mega-MUSCLES Treasury Survey, and additional stars including Proxima Cen and Trappist-1.This multiyear theory program is supported by a grant from the Space Telescope Science Institute.

The first optical spectra of Wolf-Rayet stars in M101 revealed with Gemini/GMOS

Science.gov (United States)

Pledger, J. L.; Shara, M. M.; Wilde, M.; Crowther, P. A.; Long, K. S.; Zurek, D.; Moffat, A. F. J.

2018-01-01

Deep narrow-band Hubble Space Telescope (HST) imaging of the iconic spiral galaxy M101 has revealed over a thousand new Wolf-Rayet (WR) candidates. We report spectrographic confirmation of 10 He II-emission line sources hosting 15 WR stars. We find WR stars present at both sub- and super-solar metallicities with WC stars favouring more metal-rich regions compared to WN stars. We investigate the association of WR stars with H II regions using archival HST imaging and conclude that the majority of WR stars are in or associated with H II regions. Of the 10 emission lines sources, only one appears to be unassociated with a star-forming region. Our spectroscopic survey provides confidence that our narrow-band photometric candidates are in fact bona fide WR stars, which will allow us to characterize the progenitors of any core-collapse supernovae that erupt in the future in M101.

Massive Stars as Progenitors of Supernovae and GRBs

NARCIS (Netherlands)

Langer, N.; van Marle, A.J.; Poelarends, A.J.T.; Yoon, S.C.

2007-01-01

The evolutionary fate of massive stars in our Milky Way is thought to be reasonably well understood: stars above ˜ 8 M_o produce neutron stars and supernovae, while those above ˜ 20...30 M_o are presumed to form black holes. At metallicities below that of the SMC, however, our knowledge becomes

PHP, SOL ve AJAX teknolojileri kullanarak Hacettepe Üniversitesi biyoloji bölümü herbaryumu için bir sorgulama yazılımının geliştirilmesi

OpenAIRE

Enginer, Erman

2009-01-01

Bu çalısmada Hacettepe Üniversitesi Biyoloji Bölümü Herbaryumu’ndaki (HUB) veriler kullanılarak PHP, SQL ve AJAX teknoljileri ile bir herbaryum sorgulama programı gelistirilmistir. Herbaryumlar özellikle botanik, ekolojik ve eczacılık çalısmaları için bir bilgi kaynagı olusturmaktadır. Bu kaynagın sistemli bir sekilde bilgisayar ortamındaki bir veritabanına aktarımı ile veritabanlarının bize sagladıgı hızlı sorgulama ve düzenli kayıt tutma imkanlarından faydalanabiliriz. ...

The formation and evolution of M33 as revealed by its star clusters

Science.gov (United States)

San Roman, Izaskun

2012-03-01

Numerical simulations based on the Lambda-Cold Dark Matter (Λ-CDM) model predict a scenario consistent with observational evidence in terms of the build-up of Milky Way-like halos. Under this scenario, large disk galaxies derive from the merger and accretion of many smaller subsystems. However, it is less clear how low-mass spiral galaxies fit into this picture. The best way to answer this question is to study the nearest example of a dwarf spiral galaxy, M33. We will use star clusters to understand the structure, kinematics and stellar populations of this galaxy. Star clusters provide a unique and powerful tool for studying the star formation histories of galaxies. In particular, the ages and metallicities of star clusters bear the imprint of the galaxy formation process. We have made use of the star clusters to uncover the formation and evolution of M33. In this dissertation, we have carried out a comprehensive study of the M33 star cluster system, including deep photometry as well as high signal-to-noise spectroscopy. In order to mitigate the significant incompleteness presents in previous catalogs, we have conducted ground-based and space-based photometric surveys of M33 star clusters. Using archival images, we have analyzed 12 fields using the Advanced Camera for Surveys Wide Field Channel onboard the Hubble Space Telescope (ACS/HST) along the major axis of the galaxy. We present integrated photometry and color-magnitude diagrams for 161 star clusters in M33, of which 115 were previously uncataloged. This survey extends the depth of the existing M33 cluster catalogs by ˜ 1 mag. We have expanded our search through a photometric survey in a 1° x 1° area centered on M33 using the MegaCam camera on the 3.6m Canada-France-Hawaii Telescope (CFHT). In this work we discuss the photometric properties of the sample, including color-color diagrams of 599 new candidate stellar clusters, and 204 confirmed clusters. Comparisons with models of simple stellar populations

Yaşam Bilimleri ve Biyoteknoloji

Directory of Open Access Journals (Sweden)

Nalan YILMAZ SARIÖZLÜ

2010-10-01

Full Text Available Eskişehir/Türkiye’deki ılıca sularındaki bakteriyel topluluğun ortaya konulması ve incelenmesi için 7 ılıca su örneği 7 farklı ılıcadan toplanmıştır. Tüm örnekler dört farklı besi ortamına (nutrient agar, su-maya ekstraktı agar, triptik soy agar, nişasta-kazein agar inoküle edilmiştir. 50 °C’de 14 günlük inkübasyondan sonra tüm bakteri kolonilerinin sayımı yapılıp saflaştırılmıştır. Tüm izolatların gram reaksiyonları, katalaz veoksidazözellikleri belirlenmişve BIOLOG, VITEK veotomatikribotiplendirme sisteminde (RiboPrinter incelenmişlerdir. Bu bakterilerin ampisilin, gentamisin, trimetoprim-sülfametoksazol ve tetrasiklin antibiyotiklerine karşı dirençliliği incelenmiştir. Sonuç olarak normal insan florasına ilaveten ısıya dirençli patojenik mikroorganizmalar incelenen alandaki ılıca sularında (43-50 °C belirlenmiştir. Altı genusa ait 10 farklı tür Alysiella filiformis, Bordetella bronchiseptica, B. pertussis, Molexalla caprae, M. caviae, M. cuniculi, M. phenylpyruvica, Roseomonas fauriae, Delftia acidovorans ve Pseudomonas taetrolens olarak tanımlanmıştır

Yaşam Bilimleri ve Biyoteknoloji

Directory of Open Access Journals (Sweden)

Kazım UYSAL

2011-02-01

Full Text Available Yoğun zirai faaliyetlerin yapıldığı Antalya’nın batı sahillerinden yakalanan ekonomik önemi olan bazı deniz balıklarının (Diplodus sargus, Siganus rivulatus, Lithognathus mormyrus, Liza aurata, Chelon labrasus kas, deri ve solungaçlarındaki bakır, çinko, mangan, demir ve magnezyum (Genellikle zirai aktivitelerden kaynaklanırlar biyoakümülasyon seviyeleri araştırılmıştır. Balıkların dokularında incelenen elementlerin minimum ve maksimum seviyeleri (mg kg-1 yaş ağırlık bakır için 0.541.69; çinko için 4.14-407.23; mangan için 0.15-9.17; demir için 3.45-104.49 ve magnezyum için 204.33- 784.30 olarak tespit edilmiştir. İncelenen elementlerin en düşük biyoakümülasyon seviyeleri kas dokularda, en yüksek seviyeler (Bakır hariç ise solungaçlarda tespit edilmiştir. İncelenen türlerin kas dokularındaki bakır ve çinko seviyeleri (Dünya Sağlık Örgütü (WHO, Gıda ve Tarım Örgütü (FAO ve Türk Gıda Kodeksi’nde belirtilen kabul edilebilir maksimum seviyelerden daha düşük, bazı türlerin (D. sargus, S. rivulatus, L. mormyrus and L. aurata derilerinde bulunan çinko seviyeleri ise kabul edilebilir maksimum seviyelerden daha yüksek bulunmuştur

MOLECULAR CLOUDS IN THE TRIFID NEBULA M20: POSSIBLE EVIDENCE FOR A CLOUD-CLOUD COLLISION IN TRIGGERING THE FORMATION OF THE FIRST GENERATION STARS

International Nuclear Information System (INIS)

Torii, K.; Enokiya, R.; Sano, H.; Yoshiike, S.; Hanaoka, N.; Ohama, A.; Furukawa, N.; Dawson, J. R.; Moribe, N.; Oishi, K.; Nakashima, Y.; Okuda, T.; Yamamoto, H.; Kawamura, A.; Mizuno, N.; Onishi, T.; Fukui, Y.; Maezawa, H.; Mizuno, A.

2011-01-01

A large-scale study of the molecular clouds toward the Trifid Nebula, M20, has been made in the J = 2-1 and J = 1-0 transitions of 12 CO and 13 CO. M20 is ionized predominantly by an O7.5 star HD164492. The study has revealed that there are two molecular components at separate velocities peaked toward the center of M20 and that their temperatures-30-50 K as derived by a large velocity gradient analysis-are significantly higher than the 10 K of their surroundings. We identify the two clouds as the parent clouds of the first generation stars in M20. The mass of each cloud is estimated to be ∼10 3 M sun and their separation velocity is ∼8 km s -1 over ∼1-2 pc. We find that the total mass of stars and molecular gas in M20 is less than ∼3.2 x 10 3 M sun , which is too small by an order of magnitude to gravitationally bind the system. We argue that the formation of the first generation stars, including the main ionizing O7.5 star, was triggered by the collision between the two clouds in a short timescale of ∼1 Myr, a second example alongside Westerlund 2, where a super-star cluster may have been formed due to cloud-cloud collision triggering.

M(1,6-HEXANEDİTHİOLNi(CN4 BİLEŞİKLERİNİN KIRMIZIALTI SPEKTROSKOPİSİ İLE İNCELENMESİ (M=Ni, Cd, Co, Mn VE Zn

Directory of Open Access Journals (Sweden)

Zeki KARTAL

2009-02-01

Full Text Available Bu çalışmada, genel formülü M(1,6-HexanedithiolNi(CN4 (M = Ni, Cd, Co, Mn ve Zn olan Hofmann-tipi bileşikler kimyasal yollardan ilk kez elde edildi. Elde edilen bileşiklerin kırmızıaltı spektrumları, 4000 cm-1- 400 cm-1 bölgesinde kaydedildi. Spektrumların incelenmesi, bileşik yapılarının │M-Ni(CN4│∞ polimerik tabakalardan oluştuğunu ve ligand molekülünün, kare düzlemsel yapıdaki metal atomlarına kükürt atomlarından bağlandığını göstermektedir.

Spiral Structure and Global Star Formation Processes in M 51

Science.gov (United States)

Gruendl, Robert A.

1994-12-01

The nearby grand design spiral galaxy, M 51, is an obvious proving ground for studies of spiral structure and large scale star formation processes. New near--infrared observations of M 51 made with COB (Cryogenic Optical Bench) on the Kitt Peak 1.3m allow us to examine the stellar distribution and the young star formation regions as well as probe regions of high extinction such as dust lanes. We also present an analysis of the kinematics of the ionized gas observed with the Maryland--Caltech Imaging Fabry Perot. The color information we derive from the near--infrared bands provides a more accurate tracer of extinction than optical observations. We find that the dust extinction and CO emission in the arms are well correlated. Our kinematic data show unambiguously that these dense gas concentrations are associated with kinematic perturbations. In the inner disk, these perturbations are seen to be consistent with the streaming motions predicted by classical density wave theory. The dust lanes, and presumably the molecular arms, form a narrow ridge that matches these velocity perturbations wherever the viewing angle is appropriate. This interpretation requires that the corotation radius be inward of the outer tidal arms. The outer tidal arms however show streaming velocities of the sign that would be expected interior to the corotation point. This can be reconciled if the outer arms are part of a second spiral pattern, most likely due to the interaction with the companion NGC 5195. The near--infrared observations also show emission from the massive star forming regions. These observations are less affected by extinction than optical observations of H II regions and show clearly that the sites of massive star formation are correlated with but downstream from the concentrations of dense molecular material. This provides clear evidence that the ISM has been organized by the streaming motions which have in turn triggered massive star formation.

MAGNETIC CYCLES IN A DYNAMO SIMULATION OF FULLY CONVECTIVE M-STAR PROXIMA CENTAURI

Energy Technology Data Exchange (ETDEWEB)

Yadav, Rakesh K.; Wolk, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Christensen, Ulrich R. [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Poppenhaeger, Katja, E-mail: rakesh.yadav@cfa.harvard.edu [Astrophysics Research Center, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom)

2016-12-20

The recent discovery of an Earth-like exoplanet around Proxima Centauri has shined a spot light on slowly rotating fully convective M-stars. When such stars rotate rapidly (period ≲20 days), they are known to generate very high levels of activity that is powered by a magnetic field much stronger than the solar magnetic field. Recent theoretical efforts are beginning to understand the dynamo process that generates such strong magnetic fields. However, the observational and theoretical landscape remains relatively uncharted for fully convective M-stars that rotate slowly. Here, we present an anelastic dynamo simulation designed to mimic some of the physical characteristics of Proxima Centauri, a representative case for slowly rotating fully convective M-stars. The rotating convection spontaneously generates differential rotation in the convection zone that drives coherent magnetic cycles where the axisymmetric magnetic field repeatedly changes polarity at all latitudes as time progress. The typical length of the “activity” cycle in the simulation is about nine years, in good agreement with the recently proposed activity cycle length of about seven years for Proxima Centauri. Comparing our results with earlier work, we hypothesis that the dynamo mechanism undergoes a fundamental change in nature as fully convective stars spin down with age.

Bitkisel Ürünlerin ve Gıda Destek Ürünlerinin İçeriklerinin Adli ve Hukuki Boyutu

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Zeynep Türkmen

2014-09-01

Full Text Available Günümüzde alternatif ya da destekleyici tedavi yöntemlerine ve bunlara bağlı olarak bitkisel ürünlere artan bir ilgi söz konusudur. Bu ürünler Gıda, Tarım ve Hayvancılık Bakanlığı’ndan gıda destek maddesi ruhsatı alınarak, “gıda takviyesi” adı altında piyasaya sürülmektedir. Bu tip ürünler ilaç statüsünde olmadığından ruhsatlandırılması ve piyasaya arzı farklılık gösterebilmektedir. Bu ürünlerle ilgili sıklıkla gözlenen sorunlar arasında kontaminasyon, katkı maddeleri, toksisite ve yanlış doz ve etiketlemeden kaynaklı tek tip üretim problemleri sayılabilir. Son zamanlarda söz konusu ürünlere ait zehirlenmeler ve ilaç etkileşimlerinin neden olduğu istenmeyen ve beklenmeyen durumlar gözlemlenmektedir. Bu gözlemler, alternatif ya da destekleyici ürün adı altında piyasaya sunulan bitkisel ürünlerin üretimi, ruhsatlandırılması, satışı ve denetimi konusunda ciddi düzenlemelere ve uygulamalara ihtiyaç olduğunu göstermektedir. Çalışmamızın amacı, laboratuarımıza içerik analizi için yönlendirilen, ikisi bakanlık onayı olmaksızın bitkisel ürün adı altında satılmakta olan, diğeri ise bakanlık onaylı sporcu destek ürünü olmak üzere üç olgudan elde edilen bulgularımızı sunmak ve ilgili olguları Türk Ceza Kanunun hükümlerine göre değerlendirmektir. Anahtar kelimeler: Bitkisel ürünler, Sibutramine, sporda kullanılan destek ürünleri, Cinnarizine, GC-MS.

Gas, dust, stars, star formation, and their evolution in M 33 at giant molecular cloud scales

Science.gov (United States)

Komugi, Shinya; Miura, Rie E.; Kuno, Nario; Tosaki, Tomoka

2018-04-01

We report on a multi-parameter analysis of giant molecular clouds (GMCs) in the nearby spiral galaxy M 33. A catalog of GMCs identifed in 12CO(J = 3-2) was used to compile associated 12CO(J = 1-0), dust, stellar mass, and star formation rate. Each of the 58 GMCs are categorized by their evolutionary stage. Applying the principal component analysis on these parameters, we construct two principal components, PC1 and PC2, which retain 75% of the information from the original data set. PC1 is interpreted as expressing the total interstellar matter content, and PC2 as the total activity of star formation. Young (activity compared to intermediate-age and older clouds. Comparison of average cloud properties in different evolutionary stages imply that GMCs may be heated or grow denser and more massive via aggregation of diffuse material in their first ˜ 10 Myr. The PCA also objectively identified a set of tight relations between ISM and star formation. The ratio of the two CO lines is nearly constant, but weakly modulated by massive star formation. Dust is more strongly correlated with the star formation rate than the CO lines, supporting recent findings that dust may trace molecular gas better than CO. Stellar mass contributes weakly to the star formation rate, reminiscent of an extended form of the Schmidt-Kennicutt relation with the molecular gas term substituted by dust.

StAR Protein Stability in Y1 and Kin-8 Mouse Adrenocortical Cells.

Science.gov (United States)

Clark, Barbara J; Hudson, Elizabeth A

2015-03-04

The steroidogenic acute regulatory protein (STAR) protein expression is required for cholesterol transport into mitochondria to initiate steroidogenesis in the adrenal and gonads. STAR is synthesized as a 37 kDa precursor protein which is targeted to the mitochondria and imported and processed to an intra-mitochondrial 30 kDa protein. Tropic hormone stimulation of the cAMP-dependent protein kinase A (PKA) signaling pathway is the major contributor to the transcriptional and post-transcriptional regulation of STAR synthesis. Many studies have focused on the mechanisms of cAMP-PKA mediated control of STAR synthesis while there are few reports on STAR degradation pathways. The objective of this study was to determine the effect of cAMP-PKA-dependent signaling on STAR protein stability. We have used the cAMP-PKA responsive Y1 mouse adrenocortical cells and the PKA-deficient Kin-8 cells to measure STAR phosphorylation and protein half-life. Western blot analysis and standard radiolabeled pulse-chase experiments were used to determine STAR phosphorylation status and protein half-life, respectively. Our data demonstrate that PKA-dependent STAR phosphorylation does not contribute to 30 kDa STAR protein stability in the mitochondria. We further show that inhibition of the 26S proteasome does not block precursor STAR phosphorylation or steroid production in Y1 cells. These data suggest STAR can maintain function and promote steroidogenesis under conditions of proteasome inhibition.

Demonstrating the likely neutron star nature of five M31 globular cluster sources with Swift-NuSTAR spectroscopy

DEFF Research Database (Denmark)

Maccarone, Thomas J.; Yukita, Mihoko; Hornschemeier, Ann

2016-01-01

of simultaneous Swift and NuSTAR spectra which cover a broader range of energies. These new observations reveal spectral curvature above 6-8 keV that would be hard to detect without the broader energy coverage the NuSTAR data provide relative to Chandra and XMM-Newton. We show that the other three sources...

The dynamics of z = 0.8 Hα-selected star-forming galaxies from KMOS/CF-HiZELS

International Nuclear Information System (INIS)

Sobral, D.; Matthee, J.; Swinbank, A. M.; Stott, J. P.; Bower, R. G.; Smail, Ian; Sharples, R. M.; Best, P.; Geach, J. E.

2013-01-01

We present the spatially resolved Hα dynamics of 16 star-forming galaxies at z ∼ 0.81 using the new KMOS multi-object integral field spectrograph on the ESO Very Large Telescope. These galaxies, selected using 1.18 μm narrowband imaging from the 10 deg 2 CFHT-HiZELS survey of the SA 22 hr field, are found in a ∼4 Mpc overdensity of Hα emitters and likely reside in a group/intermediate environment, but not a cluster. We confirm and identify a rich group of star-forming galaxies at z = 0.813 ± 0.003, with 13 galaxies within 1000 km s –1 of each other, and seven within a diameter of 3 Mpc. All of our galaxies are 'typical' star-forming galaxies at their redshift, 0.8 ± 0.4 SFR z=0.8 ∗ , spanning a range of specific star formation rates (sSFRs) of 0.2-1.1 Gyr –1 and have a median metallicity very close to solar of 12 + log(O/H) = 8.62 ± 0.06. We measure the spatially resolved Hα dynamics of the galaxies in our sample and show that 13 out of 16 galaxies can be described by rotating disks and use the data to derive inclination corrected rotation speeds of 50-275 km s –1 . The fraction of disks within our sample is 75% ± 8%, consistent with previous results based on Hubble Space Telescope morphologies of Hα-selected galaxies at z ∼ 1 and confirming that disks dominate the SFR density at z ∼ 1. Our Hα galaxies are well fitted by the z ∼ 1-2 Tully-Fisher (TF) relation, confirming the evolution seen in the zero point. Apart from having, on average, higher stellar masses and lower sSFRs, our group galaxies at z = 0.81 present the same mass-metallicity and TF relation as z ∼ 1 field galaxies and are all disk galaxies.

Köyyollarının Takibi, Bakım Ve Onarımı İçin Coğrafi Bilgi Sistemi (CBS Esaslı Yönetim Modeli: Denizli Örneği

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Yetiş Şazi Murat

2013-06-01

Full Text Available Coğrafi Bilgi Sistemleri (CBS özellikle gelişmiş ülkelerde her alanda sıklıkla kullanılan bir araç haline gelmişken Türkiye' de, merkezi ve yerel yönetimlerce benimsenmiş olmakla birlikte kamu hizmetlerinde kullanımı ise henüz emekleme aşamasındadır. Denizli İl Özel İdaresi Yol ve Ulaşım Hizmetleri Müdürlüğü bünyesinde il sınırları içindeki sorumluluk ve hizmet alanında bulunan köyyolları envanterinin güncellenmesi, farklı analiz sonuçları üzerinden Müdürlüğün kırsal altyapı hizmetlerine modern ve teknik yöntemlerle yön verilmesi amaçlı CBS destekli bir çalışma ortaya konulmuştur. Strateji Geliştirme Müdürlüğü ile birlikte yürütülen bu çalışmada farklı amaçlar için geliştirilmiş olan katmanlar, topoğrafik haritalar, uydu fotoğrafları vb. araçlardan istifade edilerek köyyolları ile ilgili yürütülen hizmetin doğru ve güncel verilere dayalı olmasına çalışılmıştır. Kamu kaynaklarının etkin kullanılmasını sağlayabilecek hassas ve hızlı analiz sonuçlarına göre köyyolları ulaşımının yeniden planlanması, eksik ve hatalı durumların tespiti ile tam ve bütünleşik bir yönetim sistemi kurulması amaçlı pilot bir proje ortaya konulmaya ve ürün olarak kullanılması yoluna gidilmiştir.

Lactobacillus casei’nin Sağlık Üzerine Etkileri ve Gıda Endüstrisinde Kullanımı

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Vesile Funda Sömer

2015-02-01

Full Text Available Lactobacillus casei suşları çiğ ve fermente süt ürünleri, taze sebzeler, bitkisel fermente ürünler, anne sütü, insan ve diğer sıcakkanlıların sindirim sistemi, toprak ve göl gibi çeşitli ortamlarda yaygın olarak bulunmaktadır. Bu bakteriler yüksek miktarda laktik asit üretimi, ürünlerin lezzet, aroma ve duyusal özelliklerini iyileştirme, düşük pH ve safra tuzuna yüksek tolerans, antimikrobiyel ve antidiyarejenik gibi özellikleri sayesinde gıda endüstrisinde, özellikle fermente süt ürünlerinin üretilmesinde başlatıcı kültür ve probiyotik olarak kullanılmaktadır. L. casei suşlarının kanser tedavi sürecini hızlandırma, bağışıklık sistemini uyarma, kolesterol seviyesini düşürme, çeşitli kronik hastalıklara karşı etki gösterme, patojen mikroorganizmaların gelişmesinin engellenmesi gibi sağlık üzerine pek çok olumlu etkisi belirlenmiştir. Bu derlemede L. casei’nin sağlık üzerindeki olumlu etkileri ve endüstriyel kullanım alanlarına değinilirken, bu konuda yapılan çalışmalardan örnekler verilmektedir.

Surke'nin Bazı Kimyasal ve Mikrobiyolojik Kalite Nitelikleri

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Ufuk Kamber

2015-02-01

Full Text Available Bu çalışma, Hatay ilinde tüketilen ve halk arasında Surke peyniri olarak kabul edilen süt ürününün bazı kimyasal ve mikrobiyolojik özeliklerini ortaya koymak ve Surke' yi tanıtmak amacıyla yapılmıştır. On örnek üzerinde yapılan analizlerde Surke peynirinde ortalama mikrobiyolojik analiz sonuçları sırasıyla toplam aerob mezofil bakteri; 6.5x108 kob/g, laktobasiller 4.4x107kob/g, laktokoklar 2.8x102 kob/g, mikrokok ve stafilokoklar 2.5x102 kob/g, enterobakteriler 3.5x102 kob/g, koliform grubu bakteriler <2.0x102kob/g, ve maya/küf ise 2.7x105 kob/g düzeyinde izole edilmiştir. Kimyasal analiz bulgularına göre ortalama; peynirlerde kuru madde miktarı % 52.8, yağ % 11.0, tuz % 8.1 ve asitlik laktik asit (LA cinsinden % 2.1 olarak saptanmıştır.

AN M DWARF COMPANION TO AN F-TYPE STAR IN A YOUNG MAIN-SEQUENCE BINARY

Energy Technology Data Exchange (ETDEWEB)

Eigmüller, Ph.; Csizmadia, Sz.; Erikson, A.; Fridlund, M.; Pasternacki, Th.; Rauer, H. [Institute of Planetary Research, German Aerospace Center Rutherfordstr. 2, D-12489 Berlin (Germany); Eislöffel, J.; Lehmann, H.; Hartmann, M.; Hatzes, A. [Thüringer Landessternwarte Tautenburg Sternwarte 5, D-07778 Tautenburg (Germany); Tkachenko, A. [Instituut voor Sterrenkunde, KU Leuven Celestijnenlaan 200D, 3001 Leuven (Belgium); Voss, H., E-mail: philipp.eigmueller@dlr.de [Universitat de Barcelona, Department of Astronomy and Meteorology Martí i Franquès, 1, E-08028 Barcelona (Spain)

2016-03-15

Only a few well characterized very low-mass M dwarfs are known today. Our understanding of M dwarfs is vital as these are the most common stars in our solar neighborhood. We aim to characterize the properties of a rare F+dM stellar system for a better understanding of the low-mass end of the Hertzsprung–Russel diagram. We used photometric light curves and radial velocity follow-up measurements to study the binary. Spectroscopic analysis was used in combination with isochrone fitting to characterize the primary star. The primary star is an early F-type main-sequence star with a mass of (1.493 ± 0.073) M{sub ⊙} and a radius of (1.474 ± 0.040) R{sub ⊙}. The companion is an M dwarf with a mass of (0.188 ± 0.014) M{sub ⊙} and a radius of (0.234 ± 0.009) R{sub ⊙}. The orbital period is (1.35121 ± 0.00001) days. The secondary star is among the lowest-mass M dwarfs known to date. The binary has not reached a 1:1 spin–orbit synchronization. This indicates a young main-sequence binary with an age below ∼250 Myr. The mass–radius relation of both components are in agreement with this finding.

Klasifikasi Belimbing Menggunakan Naïve Bayes Berdasarkan Fitur Warna RGB

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Fuzy Yustika Manik

2017-01-01

Full Text Available Post harvest issues on star fruit are produced on a large scale or industry is sorting. Currently, star fruit classified by rind color analysis visually human eye. This method does not effective and inefficient. The research aims to classify the starfruit sweetness level by using image processing techniques. Features extraction used is the value of Red, Green and Blue (RGB to obtain the characteristics of the color image. Then the feature extraction results used to classify the star fruit with Naïve Bayes method. Starfruit image data used 120 consisting of 90 training data and 30 testing data. The results showed the classification accuracy using RGB feature extraction by 80%. The use of RGB as the color feature extraction can not be used entirely as a feature of the image extraction of star fruit.

Yerel E-Katılımın Yeni Aracı Olarak Sosyal Ağlar: Facebook ve Twitter Örneği

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Levent MEMİŞ

2015-04-01

Full Text Available Bu araştırmada, son yıllarda örgütleri ve bireylerin iletişim veya etkileşim sürecine yeni bir hız kazandıran sosyal ağların, daha da özelde Facebook ve Twitter araçlarının, belediye örgütleri ve belediye başkanları düzeyinde, yerel kamusal politikalara katılım bağlamında, “ne düzeyde” ve “nasıl” kullanıldığının ortaya çıkarılmasına çalışılmıştır. Bu kapsamda, kişisel düzeyde 6 belediye başkanının Facebook ve 12 belediye başkanının Twitter; kurumsal düzeyde ise 22 belediyenin Facebook ve yine 22 belediyenin Twitter hesabı araştırma kapsamında niteliksel içerik analizi yöntemiyle incelenmiştir. Çalışmanın genel sonuçlarına göre, kişisel Twitter hesaplarında sorunları ileten/bilgi talep eden etkileşim öne çıkmakla birlikte, hesaplardaki üye sayısı dikkate alındığında sınırlı düzeyde etkileşimin olduğu, daha çok katılımın ilk evresi olarak kabul edilen bilgi aktaran, doğrudan katılımı teşvik etmeyen biçiminde kullanıldığı tespit edilmiştir.

Hacettepe Üniversitesi Bilgi ve Belge Yönetimi Bölümü Tezlerinin Atıf Analizi

OpenAIRE

Umut Al; Güleda Doğan

2013-01-01

Çalışma Hacettepe Üniversitesi Bilgi ve Belge Yönetimi Bölümünde tamamlanan lisansüstü tezleri ve söz konusu tezlerin kaynakçalarındaki atıfları incelemektedir. Araştırma sonucunda elde edilen başlıca bulguları şu şekilde sıralamak olanaklı­dır: Bölümde yılda ortalama dört tez tamamlanmıştır. Tezlerde en sık başvurulan araştırma yöntemi betimlemedir. Tezlerde üniversite kütüphaneleri, halk kütüp­haneleri, okuma alışkanlığı ve kullanıcı araştırmaları konuları öne çıkmaktadır. Nilüfer Tuncer, İ...

Farklı Tüy Dökümü Yöntemlerinin ve Tüy Dökümü Sonrası Karma Yeme Üzüm Posası Katılmasının Performans, Yumurta Kalitesi ve Yumurta Lipid Peroksidasyonuna Etkisi

OpenAIRE

KARA, K.; GÜÇLÜ, B. KOCAOĞLU

2014-01-01

Sunulan çalışma, kekliklerde faringeal ve laringeal bölgenin makroskobik ve mikroskobik özellikleri ile bu bölümlerdeki bezlerin histokimyasal özelliklerini detaylı bir şekilde tanımlamak için planlanmıştır. Çalışmada 5 dişi ve 5 erkek olmak üzere toplam 10 adet erişkin ve sağlıklı kınalı keklik kullanıldı. Eter anastezisi altında dil ile beraber farinks ve larinks total olarak diseke edildi ve dokular rutin histolojik işlemleri takiben parafinde bloklandı. Kınalı keklikte anatomik olarak glo...

FİLMLERLE İLETİŞİM VE YABANCILAŞMA

OpenAIRE

ÖZTÜRK, Serdar

2018-01-01

Yabancılaşma konusu genellikle iktisadi, sosyolojik ve psikoloji boyutlarıyla tartışılmıştır. Oysa bir anlam paylaşımı olarak iletişim, yabancılaşmayla doğrudan ilişkilidir. Buna karşın iletişim ile yabancılaşma ilişkisini, analize filmleri de katarak inceleyen çok az çalışma bulunmaktadır. Bu çalışma, yabancılaşma kavramını tartışarak, yabancılaşmanın iletişim ile ilişkisini incelemektedir. Buna göre insanın kendi ürettiği sembollerine, medyanın üretim bölgesinde üretilen sembollere yabancıl...

HAT-P-49b: a 1.7 M {sub J} planet transiting a bright 1.5 M {sub ☉} F-star

Energy Technology Data Exchange (ETDEWEB)

Bieryla, A.; Latham, D. W.; Buchhave, L. A.; Béky, B.; Falco, E.; Torres, G.; Noyes, R. W.; Berlind, P.; Calkins, M. C.; Esquerdo, G. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Csubry, Z.; Penev, K.; De Val-Borro, M. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Kovács, G. [Konkoly Observatory, Budapest 1121 (Hungary); Boisse, I. [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Lázár, J.; Papp, I., E-mail: abieryla@cfa.harvard.edu, E-mail: gbakos@astro.princeton.edu [Hungarian Astronomical Association (HAA), Budapest 1461 (Hungary); and others

2014-04-01

We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V = 10.3) slightly evolved F-star HD 340099 with a mass of 1.54 M {sub ☉} and a radius of 1.83 R {sub ☉}. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter-McLaughlin follow-up due to the host star's fast rotation, 16 km s{sup –1}. The planetary companion has a period of 2.6915 days, mass of 1.73 M {sub J}, and radius of 1.41 R {sub J}. The planetary characteristics are consistent with that of a classical hot Jupiter but we note that this is the fourth most massive star to host a transiting planet with both M{sub p} and R{sub p} well determined.

YAZILIM TEKRAR KULLANIMI VE NESNEYE YÖNELİK YAKLAŞIM

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Halil ŞENGONCA

1995-02-01

Full Text Available Yazılımın tekrar kullanımı, bir yazılım sisteminin geliştirilmesinde kullanılan bilginin ve ürünlerin, başka bir yazılım sistemi için kullanılmasıdır. Yazılımın tekrar kullanımı için kaynak kod bileşenlerinden oluşan bir kütüphane ve karmaşık sistemlerin bu yapı bloklarından oluşturulması fikri, ilk olarak 1968'te Dough McIlroy tarafından önerilmiştir. Günümüzde programlama dilleri, kullanılan teknikler ve araçlar çok değişmesine rağmen yazılımın tekrar kullanımı yazılım geliştirme maliyetlerini azaltmak ve kaliteyi yükseltmek için hala bir çözüm olarak görülmektedir. Nesneye yönelik programlama, kalıtım, koruma gibi özellikleriyle, kaynak kod bileşenlerinin oluşturulmasını ve kullanımını desteklemektedir. Yine de yazılım tekrar kullanımını bir kuruluş düzeyinde gerçekleştirmek için planlı ve koordineli bir programa gereksinim vardır. Bu makalede, yazılım tekrar kullanımı tanımlanmış ve nesneye yönelik yaklaşım ile yazılım tekrar kullanımını amaçlayan bir yazılım geliştirme süreci tanıtılmıştır. Ayrıca bir kuruluşun yazılım tekrar kullanımını kurumsallaştırma süreci için bir strateji önerilmiştir.

Cabernet Sauvignon ve Merlot Şarapların Resveratrol Düzeyleri ve Ekolojik Koşulların Etkileri

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Belkıs Çaylak Adıgüzel

2015-02-01

Full Text Available Fitoaleksinler bitkilerde patojen enfeksiyonuna bir reaksiyon olarak veya çeşitli biyotik ve abiyotik tetikleyicilerin etkisi sonucu oluşan fenolik madde karakterli, düşük molekül ağırlıklı antimikrobiyal bileşiklerdir. Resveratrol (trans–3,5,4’-trihidroksistilben de bir fitoaleksin olup, asma (Vitis vinifera, yer fıstığı (Arachis hypogaea ve diğer pek çok bitki türünde yaprak veya diğer organlarda yüksek miktarlarda bulunabilmektedir. Resveratrol asmada gövde, sürgün ve yapraklar yanında, özellikle renkli çeşitlerin tane kabuğunda bol miktarda sentezlenebilmekte ve şarap yapımı sırasında şıraya, şıradan da şaraba geçmektedir. Son yıllarda resveratrolün antikanserojen özelliği ve antioksidan karakteri nedeniyle sağlık yararları üzerine yoğun araştırmalar yapılmakta ve günlük diyette alımı önerilmektedir. Bu çalışmada, Ege, Marmara ve Trakya Bölgeleri’nde üretilen kimi bağlardan sağlanan Cabernet sauvignon ve Merlot siyah üzümlerinden üretilmiş şaraplarda bulunan resveratrol miktarları Yüksek Performanslı Sıvı Kromatografisi yöntemi kullanılarak belirlenmiştir. Elde edilen sonuçlar bölgelerin ekolojik koşulları açısından birbirleriyle karşılaştırılmış ve resveratrol miktarı ile bu parametreler arasındaki korelasyon araştırılmıştır. Resveratrol konsantrasyonunun üzüm çeşidi ve bölgelerin iklim şartlarına bağlı olarak farklılıklar gösterebileceği görülmüştür.

Luminosities and temperatures of M dwarf stars from infrared photometry

Science.gov (United States)

Veeder, G. J.

1974-01-01

Bolometric magnitudes for a large number of M type dwarf stars, obtained by broadband infrared photometry at 1.65, 2.2, and 3.5 microns, are reviewed. The data obtained indicate that one parameter is sufficient to describe the blanketing in all of the UBVRI bands for all types of M dwarfs. In general, late M dwarfs seem to have lower effective temperatures than are predicted by theoretical models.

Atmospheric Parameters and Metallicities for 2191 Stars in the Globular Cluster M4

Science.gov (United States)

Malavolta, Luca; Sneden, Christopher; Piotto, Giampaolo; Milone, Antonino P.; Bedin, Luigi R.; Nascimbeni, Valerio

2014-02-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V 14.7, we obtain lang[Fe/H]rang = -1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

Physics Colloquium | 8 April

CERN Document Server

2013-01-01

The echo of the Big Bang as seen by the Planck satellite, Professeur Martin Kunz, département de Physique théorique, Université de Genève. Monday 8 April 2013, 5 pm École de Physique, Auditoire Stueckelberg 24, quai Ernest-Ansermet, 1211 Genève 4 Abstract: On March 21st, ESA’s Planck space telescope released the most detailed map ever created of the cosmic microwave background – the relic radiation from the Big Bang. The map shows the Universe at a time when it was just 380 000 years old, and the tiny fluctuations that it contains represent the seeds of all future structure: the stars and galaxies of today. From this map, we can learn many things, for example that 95% of the "stuff'' in the Universe are different from anything we have encountered on Earth. The new data by the Planck satellite agree quite well with the cosmological standard model, and we will see what this implies for our understa...

Türk Sucuklarında Ticari Starter Kültür Kullanımı Üzerine Araştırmalar II. Duyusal ve Mikrobiyolojik Analizler

Directory of Open Access Journals (Sweden)

Halil Vural

2015-02-01

Full Text Available Bu çalışmada; işletme düzeyinde kontrollü koşullarda Türk sucuğu üretiminde ticari starter kültürlerin kullanımı incelenmiştir. Bu amaçla, starter kültür katılmayan örnek kontrol grubu olarak alınarak, 7 farklı ticari starter kültürle hazırlanan 8 sucuk örneği aynı koşullarda denemeye alınmıştır. Sucuklara üretimin 7 kritik noktasına mezofilik aerobik bakteri, Lactobacillus-Pedicoccus ve patojen olmayan Staphylococcus-Micrococcus sayımı analizleri ile ürün bazında duyusal analizlerle starter kültür katılarak üretilen sucukların kontrol grubuna göre belirgin üstünlük sağladıkları belirlenmiş, kimyasal, mikrobiyolojik ve duyusal analiz bulgularının birlikte değerlendirilmesi; Türk sucuğu özelliklerine en uygun sonuçları Flora Carn SL ve Flora Carn SP starter kültürleri ile yapılan sucukların verdiğini göstermiştir.

Decreased numbers of CD4+ naive and effector memory T cells, and CD8+ naïve T cells, are associated with trichloroethylene exposure

Directory of Open Access Journals (Sweden)

H Dean eHosgood

2012-01-01

Full Text Available Trichloroethylene (TCE is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE’s carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE’s early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4+ T cells, CD8+ T cells, natural killer (NK cells, and B cells were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors and/or lymphocyte survival. To explore which T lymphocyte subsets are affected, we investigated the effect of TCE exposure on the numbers of CD4+ naïve and memory T cells, CD8+ naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4+ and CD8+ naïve T cell counts were about 8% (p = 0.056 and 17% (p = 0.0002 lower, respectively, among exposed workers. CD4+ effector memory T cell counts were decreased by about 20% among TCE exposed workers compared to controls (p = 0.001. The selective targeting of TCE on CD8+ naïve and possibly CD4+ naive T cells, and CD4+ effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure.

Hyperon-mixed neutron stars

International Nuclear Information System (INIS)

Takatsuka, Tatsuyuki

2004-01-01

Hyperon mixing in neutron star matter is investigated by the G-matrix-based effective interaction approach under the attention to use the YN and the YY potentials compatible with hypernuclear data and is shown to occur at densities relevant to neutron star cores, together with discussions to clarify the mechanism of hyperon contamination. It is remarked that developed Y-mixed phase causes a dramatic softening of the neutron star equation of state and leads to the serious problem that the resulting maximum mass M max for neutron star model contradicts the observed neutron star mass (M max obs = 1.44 M Θ ), suggesting the necessity of some extra repulsion'' in hypernuclear system. It is shown that the introduction of three-body repulsion similar to that in nuclear system can resolve the serious situation and under the consistency with observation (M max > M obs ) the threshold densities for Λ and Σ - are pushed to higher density side, from 2ρ 0 to ∼ 4ρ 0 (ρ 0 being the nuclear density). On the basis of a realistic Y-mixed neutron star model, occurrence of Y-superfluidity essential for ''hyperon cooling'' scenario is studied and both of Λ- and Σ - -superfluids are shown to be realized with their critical temperatures 10 8-9 K, meaning that the hyperon cooling'' is a promising candidate for a fast non-standard cooling demanded for some neutron stars with low surface temperature. A comment is given as to the consequence of less attractive ΛΛ interaction suggested by the ''NAGARA event'' ΛΛ 6 He. (author)

Mission hazard assessment for STARS Mission 1 (M1) in the Marshall Islands area

Energy Technology Data Exchange (ETDEWEB)

Outka, D.E.; LaFarge, R.A.

1993-07-01

A mission hazard assessment has been performed for the Strategic Target System Mission 1 (known as STARS M1) for hazards due to potential debris impact in the Marshall Islands area. The work was performed at Sandia National Laboratories as a result of discussion with Kwajalein Missile Range (KMR) safety officers. The STARS M1 rocket will be launched from the Kauai Test Facility (KTF), Hawaii, and deliver two payloads to within the viewing range of sensors located on the Kwajalein Atoll. The purpose of this work has been to estimate upper bounds for expected casualty rates and impact probability or the Marshall Islands areas which adjoin the STARS M1 instantaneous impact point (IIP) trace. This report documents the methodology and results of the analysis.

Okul Müdürlerinin Yönetimle İlgili Görüş ve Uygulamalarının Yönetim Kuramları Bakımından Değerlendirilmesi

OpenAIRE

Yavuz, Mustafa

2009-01-01

Alan yazında yer alan örgüt ve yönetim kuramları yöneticilerinin uygulamaları, görüşleri ve araştırmalar tarafından şekillendirilmiş, ortaya çıkan bu görüş ve uygulamalar da yeni yöneticilerin uygulama ve davranışlarında yol gösterici bir rol üstlenmişlerdir. Okul müdürlerinin yönetim uygulama ve görüşlerinin yönetim kuramları bakımından değerlendirilmesinin önemli olduğu düşünülmektedir. Bu nedenle araştırmanın amacı, okul müdürlerinin yönetim uygulamalarının yönetim kuramları bakımından değ...

A STAR IN THE M31 GIANT STREAM: THE HIGHEST NEGATIVE STELLAR VELOCITY KNOWN

International Nuclear Information System (INIS)

Caldwell, Nelson; Kenyon, Scott J.; Morrison, Heather; Harding, Paul; Schiavon, Ricardo; Rose, James A.

2010-01-01

We report on a single star, B030D, observed as part of a large survey of objects in M31, which has the unusual radial velocity of -780 km s -1 . Based on details of its spectrum, we find that the star is an F supergiant, with a circumstellar shell. The evolutionary status of the star could be one of a post-main-sequence close binary, a symbiotic nova, or less likely, a post-asymptotic giant branch star, which additional observations could help sort out. Membership of the star in the Andromeda Giant Stream can explain its highly negative velocity.

MgB2 Süperiletken Tellerde Alternatif Akım Kaybı ve Akı Perçinleme Mekanizmaları

OpenAIRE

SAFRAN, Serap

2010-01-01

Bu çalışmada çok filamanlı Bi-2223/Ag şerit ve farklı kılıf malzemesine sahip tek ve çok filamanlı MgB₂ teller için alternatif akım (AA) kaybı deneysel olarak ölçüldü.  Bu süperiletkenler için teorik olarak manyetik alan şerit yüzeyine dik olarak uygulandığı zaman AA kayıp hesaplanarak deneysel sonuçlarla karşılaştırıldı. Deneysel verilerle hesaplamalar arasında iyi bir uyum gözlendi. Hesaplamalar için ticari sonlu elemanlar yazılımı (Comsol Multiphysi...

Thermal-orbital coupled tidal heating and habitability of Martian-sized extrasolar planets around M stars

International Nuclear Information System (INIS)

Shoji, D.; Kurita, K.

2014-01-01

M-type stars are good targets in the search for habitable extrasolar planets. Due to their low effective temperatures, the habitable zone of M stars is very close to the stars themselves. For planets that are close to their stars, tidal heating plays an important role in thermal and orbital evolutions, especially when the planet's orbit has a relatively large eccentricity. Although tidal heating interacts with the thermal state and the orbit of the planet, such coupled calculations for extrasolar planets around M stars have not been conducted. We perform coupled calculations using simple structural and orbital models and analyze the thermal state and habitability of a terrestrial planet. Considering this planet to be Martian-sized, the tide heats up and partially melts the mantle, maintaining an equilibrium state if the mass of the star is less than 0.2 times the mass of the Sun and the initial eccentricity of the orbit is more than 0.2. The reduction of heat dissipation due to the melted mantle allows the planet to stay in the habitable zone for more than 10 Gyr even though the orbital distance is small. The surface heat flux at the equilibrium state is between that of Mars and Io. The thermal state of the planet mainly depends on the initial value of the eccentricity and the mass of the star.

Thermal-orbital coupled tidal heating and habitability of Martian-sized extrasolar planets around M stars

Energy Technology Data Exchange (ETDEWEB)

Shoji, D.; Kurita, K. [Earthquake Research Institute, University of Tokyo, Tokyo (Japan)

2014-07-01

M-type stars are good targets in the search for habitable extrasolar planets. Due to their low effective temperatures, the habitable zone of M stars is very close to the stars themselves. For planets that are close to their stars, tidal heating plays an important role in thermal and orbital evolutions, especially when the planet's orbit has a relatively large eccentricity. Although tidal heating interacts with the thermal state and the orbit of the planet, such coupled calculations for extrasolar planets around M stars have not been conducted. We perform coupled calculations using simple structural and orbital models and analyze the thermal state and habitability of a terrestrial planet. Considering this planet to be Martian-sized, the tide heats up and partially melts the mantle, maintaining an equilibrium state if the mass of the star is less than 0.2 times the mass of the Sun and the initial eccentricity of the orbit is more than 0.2. The reduction of heat dissipation due to the melted mantle allows the planet to stay in the habitable zone for more than 10 Gyr even though the orbital distance is small. The surface heat flux at the equilibrium state is between that of Mars and Io. The thermal state of the planet mainly depends on the initial value of the eccentricity and the mass of the star.

Devlet ve Vakıf Üniversiteleri Eğitim Fakültesi Öğrencilerinin Cep Telefonu Kullanım Sıklıklarının ve Marka Tercihlerinin Karşılaştırılması

OpenAIRE

TUTGUN ÜNAL, Aylin; ARSLAN, Ahmet

2013-01-01

Bu araştırmada, devlet ve vakıf üniversiteleri eğitim fakültesi öğrencilerinin cep telefonu kullanım sıklıkları ve marka tercihleri incelenmiştir. Araştırma, İstanbul’da yer alan Marmara Üniversitesi Atatürk Eğitim Fakültesi ve Maltepe Üniversitesi Eğitim Fakültesi’ne devam eden 985 öğrenci ile yürütülmüştür. Verilerin toplanmasında araştırmacılar tarafından geliştirilen “Cep Telefonu Kullanımı Sıklığı ve Marka Tercihi Belirleme Formu” kullanılmıştır. Araştırmada, eğitim fakültesi öğrencileri...

Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

International Nuclear Information System (INIS)

Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio; Sneden, Christopher; Milone, Antonino P.; Bedin, Luigi R.

2014-01-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions

Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

Energy Technology Data Exchange (ETDEWEB)

Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio [Dipartimento di Fisica e Astronomia, Vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Sneden, Christopher [Department of Astronomy and McDonald Observatory, The University of Texas, Austin, TX 78712 (United States); Milone, Antonino P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Bedin, Luigi R., E-mail: luca.malavolta@unipd.it, E-mail: giampaolo.piotto@unipd.it, E-mail: valerio.nascimbeni@unipd.it, E-mail: luigi.bedin@oapd.inaf.it, E-mail: chris@verdi.as.utexas.edu, E-mail: milone@mso.anu.edu.au [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

2014-02-01

We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

Anneden Allah'a: Bağlanma Teorisi ve İslâm'da Allah Tasavvuru

OpenAIRE

HAYTA, Akif

2006-01-01

John Bowlby tarafından geliştirilen bağlanma teorisi, yaşam boyu süren psikolojik bir sosyal ve kişilik gelişim teorisidir. Bağlanma teorisi bebek-çocuk ve bakıcısı arasındaki bağın gelişimi ve bu ilişkinin çeşitli fonksiyonlarının daha sonraki psikolojik gelişim üzerindeki etkilerine odaklanmıştır. Bağlanma teorisi bebek ve çocuk üzerine yapılan çalışmaları önemli derecede etkilemiş ve yığınla araştırmaya konu olmuştur. Aynı zamanda geniş bir alana yayılarak din psikolojisi araştırmalarında ...

Artvin, Rize ve Trabzon’daki Doğal Kaynak Sularında Toplam Alfa, Toplam Beta Aktivite Değerlerinin Belirlenmesi ve Jeoistatistiksel Olarak Modellenmesi

Directory of Open Access Journals (Sweden)

Yaşar Kobya

2014-11-01

Full Text Available Trabzon, Rize ve Artvin yaklaşık 18000km2 alan üzerine kurulmuş ve yaklaşık 2 milyon insanın yaşadığı Türkiye’nin en kuzey doğusunda bulunan üç ildir. Bu üç ilde toplam 20 tane içme suyu kaynağından örnekler alındı ve bunların toplam alfa, toplam beta aktivite değerleri Berthold LB770 marka alfa, beta sayım cihazı kullanılarak belirlendi. Toplam alfa aktivite değerleri 1.7-114.2 Bq/L ve toplam beta aktivite değerleri ise 2.9-90.8 Bq/L aralıklarında ölçüldü. Bulunan bu değerler dünya sağlık örgütü (WHO’nün limit değerleri ve yapılmış diğer benzer çalışmalarla karşılaştırıldı. Elde edilen veriler için klasik istatistik hesaplamalar yapıldı. Ayrıca jeoistatistik analiz yöntemi kullanılarak eş-doz eğrileri oluşturuldu ve harita üzerinde gösterilerek bölge için bir risk haritası oluşturuldu.

KALİTELİ UYKU VE UYKU BOZUKLUKLARI / QUALITY SLEEP AND SLEEP DISORDERS

OpenAIRE

Algın, Demet; Akdağ, Gönül; Erdinç, Oğuz

2018-01-01

Özet: Uyku sağlık ve yaşamımızın iyi bir şekilde devamı için önemli bir role sahiptir. Kaliteli uyku zihinsel sağlığımızı, fiziksel sağlığımızı, hayat kalitemizı korumamıza yardım eder ve güvenliğimiz için gereklidir. Uykunun başlatılması ve sürdürülmesi kortikal ve subkortikal birçok beyin bölgesinin işlevi ile gerçekleşir. Uykunun başlatılmasında öncelikle ön hipotalamustan gelen döngüsel girdiler ve endojen kimyasal uyarılar doğrultusunda hipotalamusta ventrolateral preoptik çekirdeğin rol...

ON THE STAR FORMATION RATES IN MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Lada, Charles J.; Lombardi, Marco; Alves, Joao F.

2010-01-01

In this paper, we investigate the level of star formation activity within nearby molecular clouds. We employ a uniform set of infrared extinction maps to provide accurate assessments of cloud mass and structure and compare these with inventories of young stellar objects within the clouds. We present evidence indicating that both the yield and rate of star formation can vary considerably in local clouds, independent of their mass and size. We find that the surface density structure of such clouds appears to be important in controlling both these factors. In particular, we find that the star formation rate (SFR) in molecular clouds is linearly proportional to the cloud mass (M 0.8 ) above an extinction threshold of A K ∼ 0.8 mag, corresponding to a gas surface density threshold of Σ gas ∼ 116 M sun pc 2 . We argue that this surface density threshold corresponds to a gas volume density threshold which we estimate to be n(H 2 ) ∼ 10 4 cm -3 . Specifically, we find SFR (M sun yr -1 ) = 4.6 ± 2.6 x 10 -8 M 0.8 (M sun ) for the clouds in our sample. This relation between the rate of star formation and the amount of dense gas in molecular clouds appears to be in excellent agreement with previous observations of both galactic and extragalactic star-forming activity. It is likely the underlying physical relationship or empirical law that most directly connects star formation activity with interstellar gas over many spatial scales within and between individual galaxies. These results suggest that the key to obtaining a predictive understanding of the SFRs in molecular clouds and galaxies is to understand those physical factors which give rise to the dense components of these clouds.

The Dushak–Erekdag Survey of roAp Stars

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... The search of roAp stars at Mt. Dushak–Erekdag Observatory was started in 1992 using the 0.8m Odessa telescope equipped with a two-star high-speed photometer. We have observed more than a dozen stars so far and discovered HD 99563 as roAp star while BD+8087 is suspected to have rapid ...

RETIRED A STARS AND THEIR COMPANIONS. III. COMPARING THE MASS-PERIOD DISTRIBUTIONS OF PLANETS AROUND A-TYPE STARS AND SUN-LIKE STARS

International Nuclear Information System (INIS)

Bowler, Brendan P.; Johnson, John Asher; Liu, Michael C.; Marcy, Geoffrey W.; Peek, Kathryn M. G.; Henry, Gregory W.; Fischer, Debra A.; Clubb, Kelsey I.; Reffert, Sabine; Schwab, Christian; Lowe, Thomas B.

2010-01-01

We present an analysis of ∼5 years of Lick Observatory radial velocity measurements targeting a uniform sample of 31 intermediate-mass (IM) subgiants (1.5 ∼ * /M sun ∼ +9 -8 %, which is significantly higher than the 5%-10% frequency observed around solar-mass stars. The median detection threshold for our sample includes minimum masses down to {0.2, 0.3, 0.5, 0.6, 1.3} M Jup within {0.1, 0.3, 0.6, 1.0, 3.0} AU. To compare the properties of planets around IM stars to those around solar-mass stars we synthesize a population of planets based on the parametric relationship dN ∝ M α P β dlnMdlnP, the observed planet frequency, and the detection limits we derived. We find that the values of α and β for planets around solar-type stars from Cumming et al. fail to reproduce the observed properties of planets in our sample at the 4σ level, even when accounting for the different planet occurrence rates. Thus, the properties of planets around A stars are markedly different than those around Sun-like stars, suggesting that only a small (∼50%) increase in stellar mass has a large influence on the formation and orbital evolution of planets.

Metil ve Etil Ester Kullanılan Bir Common-Rail Dizel Motorda Performans, Yanma ve Enjeksiyon Karakteristiklerinin Karşılaştırılması

Directory of Open Access Journals (Sweden)

Ertan ALPTEKİN

2017-02-01

Full Text Available Biyodizel, dünyada kullanımı yaygınlaşan yenilebilir ve alternatif bir dizel yakıtıdır. Biyodizel üretiminde kullanılan alkol büyük önem arz etmekte ve üretilen biyodizelin yakıt özelliklerini doğrudan etkilemektedir. Farklı yakıt özellikleri, dizel motorlarda farklı yakıt enjeksiyon ve yanma karakteristiklerine sebep olabilmektedir. Bu nedenle bu çalışmada, metanol ve etanol kullanılarak üretilen iki farklı ester yakıtı ve saf motorin, common-rail yakıt enjeksiyon sistemine sahip bir dizel motorda üç farklı motor yükü (50 Nm, 100 Nm ve 150 Nm ve 2000 dev/dk sabit motor devrinde deney yakıtı olarak kullanılmıştır. Bu yakıtların performans, yanma ve yakıt enjeksiyon analizi karşılaştırmalı olarak gerçekleştirilmiştir. Deney sonuçlarına göre, etil ve metil ester kullanımıyla özgül yakıt tüketimi (ÖYT motorine kıyasla artış göstermiştir. Etil ve metil ester yakıtlarının silindir içi basıncı ve ısı yayılımı değerleri tüm deney şartlarında motorine kıyasla daha yüksek olmuştur. Yakıt enjeksiyon karakteristikleri, yakıt tipi ve motor yüküne bağlı olarak farklılık göstermiştir.

Radurizasyonun Tavuk Etlerinin Duyusal, Kimyasal ve Mikrobiyolojik Kalitesi Üzerine Etkisi

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Nuray Kolsarıcı

2015-02-01

Full Text Available Araştırmada 1, 2 ve 3 kGy dozunda uygulanan iyonize radyasyonun (Radurizasyon tavuk but ve göğüs etlerinin mikrobiyolojik, kimyasal ve duyusal kalitelerine olan etkisi üzerinde çalışılmıştır. 6-8 haftalık broilerler kesilerek but ve göğüs etlerine parçalandıktan sonra biri açık kontrol olmak üzere 5 gruba ayrılmış ve 4 grup vakum paketlenmiştir. Vakum paketi gruplardan biri vakumlu kontrol olarak ayrılırken, diğer gruplar 1, 2 ve 3 kGy olmak üzere iyonize radyasyona tabi tutulmuştur. 0. günden başlamak üzere 3’er günlük periyotlarla gruplar analize alınmış, toplam mezofilik aerob, toplam psikrofilik aerob, stafilokok ve laktik asit bakterileri ile pH ve TBA değeri belirlenmiştir. Ayrıca örneklerin duyusal özellikleri de panel oluşturularak saptanmıştır. Elde edilen tüm veriler varyans analizi ile değerlendirilmiştir. Araştırma bulgularına göre tavuk but ve göğüs etlerinde radurizasyon sonrası bakteriyel yükte azalma gözlenmiştir. Radurizasyonun toplam mezofilik aerobik ve toplam psikrofilik aerobik bakteriler üzerine olan etkisi stafilokok ve laktik asit bakterilerine kıyasla daha yüksek düzeyde olup, özellikle laktik asit bakterilerinde zayıf kalmıştır. PH ve TBA değerleri açısından radurizasyonun değişiklik yaratmadığı gözlenmiştir. Bununla birlikte 3 kGy ışınlanmış örneklerin raf ömrü 27 gün civarında olurken 2 kGy ışınlı örnekler 24 günde, 1 kGy ışınlı örnekler 18 günde, vakumlu kontroller 15 günde, açık kontroller 9 gün civarında tüketim özelliğini yitirmiştir. Duyusal değerlendirmelerde alınan sonuçlarda ışınlanmış örneklerin renk, görünüş, aroma, gevreklik gibi özellikleri kontrollere göre farklı olmayıp, tüm gruplar pazarlanabilir nitelikte bulunmuşlardır.

Level of helium enhancement among M3's horizontal branch stars

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Valcarce, A. A. R.; Catelan, M.; Alonso-García, J.; Contreras Ramos, R.; Alves, S.

2016-05-01

Context. The color and luminosity distribution of horizontal branch (HB) stars in globular clusters (GCs) are sensitive probes of the original helium abundances of those clusters. In this sense, recently the distributions of HB stars in GC color-magnitude diagrams (CMDs) have been extensively used as indicators of possible variations in the helium content Y among the different generations of stars within individual GCs. However, recent analyses based on visual and near-ultraviolet (UV) CMDs have provided conflicting results. Aims: To clarify the situation, we address the optimum ranges of applicability (in terms of the Teff range covered by the HB stars) for visual and near-UV CMDs, as far as application of this "HB Y test" goes. Methods: We considered both Strömgren and Hubble Space Telescope (HST) bandpasses. In particular, we focus on the F336W filter of the HST, but also discuss several bluer UV bandpasses, such as F160BW, F255W, and F300W. Using the Princeton-Goddard-PUC (PGPUC) code, we computed a large set of zero-age HB (ZAHB) loci and HB evolutionary models for masses ranging from MHB = 0.582 to 0.800 M⊙, assuming an initial helium abundance Y = 0.246, 0.256, and 0.266, with a global metallicity Z = 0.001. The results of these calculations were compared against the observations of M3 (NGC 5272), with special attention on the y vs. (b - y) and F336W vs. (F336W-F555W) CMDs. Results: Our results indicate that, from an evolutionary perspective, the distributions of HB stars in the y vs. (b - y) plane can be a reliable indicator of the He content in cool blue HB (BHB) stars, particularly when a differential comparison between blue and red HB stars is carried out in the range Teff ≲ 8300 K. Conversely, we demonstrate that CMDs using the F336W filter have a much less straightforward interpretation at the cool end of the BHB because the distributions of HB stars in the F336W vs. (F336W-F555W) plane, for instance, are affected by a triple degeneracy effect. In

The UK Infrared Telescope M 33 monitoring project - V. The star formation history across the galactic disc

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Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib G.; Tabatabaei, Fatemeh; Hamedani Golshan, Roya; Rashidi, Maryam

2017-01-01

We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope of the Local Group spiral galaxy M 33 (Triangulum). On the basis of their variability, we have identified stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fifth paper of the series, we construct the birth mass function and hence derive the star formation history across the galactic disc of M 33. The star formation rate has varied between ˜0.010 ± 0.001 (˜0.012 ± 0.007) and 0.060±0.005 (0.052±0.009) M⊙ yr-1 kpc-2 statistically (systematically) in the central square kiloparsec of M 33, comparable with the values derived previously with another camera. The total star formation rate in M 33 within a galactocentric radius of 14 kpc has varied between ˜0.110 ± 0.005 (˜0.174 ± 0.060) and ˜0.560 ± 0.028 (˜0.503 ± 0.100) M⊙ yr-1 statistically (systematically). We find evidence of two epochs during which the star formation rate was enhanced by a factor of a few - one that started ˜6 Gyr ago and lasted ˜3 Gyr and produced ≥71 per cent of the total mass in stars, and one ˜250 Myr ago that lasted ˜200 Myr and formed ≤13 per cent of the mass in stars. Radial star formation history profiles suggest that the inner disc of M 33 was formed in an inside-out formation scenario. The outskirts of the disc are dominated by the old population, which may be the result of dynamical effects over many Gyr. We find correspondence to spiral structure for all stars, but enhanced only for stars younger than ˜100 Myr; this suggests that the spiral arms are transient features and not a part of a global density wave potential.

Frontal-subcortical volumetric deficits in single episode, medication-naïve depressed patients and the effects of 8 weeks fluoxetine treatment: a VBM-DARTEL study.

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Lingtao Kong

Full Text Available BACKGROUND: Convergent studies suggest that morphological abnormalities of frontal-subcortical circuits which involved with emotional and cognitive processing may contribute to the pathophysiology of major depressive disorder (MDD. Antidepressant treatment which has been reported to reverse the functional abnormalities of frontal-subcortical circuits in MDD may have treating effects to related brain morphological abnormalities. In this study, we used voxel-based morphometry method to investigate whole brain structural abnormalities in single episode, medication-naïve MDD patients. Furthermore, we investigated the effects of an 8 weeks pharmacotherapy with fluoxetine. METHODS: 28 single episode, medication-naïve MDD participants and 28 healthy controls (HC acquired the baseline high-resolution structural magnetic resonance imaging (sMRI scan. 24 MDD participants acquired a follow-up sMRI scan after 8 weeks antidepressant treatment. Gray matter volumetric (GMV difference between groups was examined. RESULTS: Medication-naïve MDD had significantly decreased GMV in the right dorsolateral prefrontal cortex and left middle frontal gyrus as well as increased GMV in the left thalamus and right insula compared to HC (P<0.05, corrected. Moreover, treated MDD had significantly increased GMV in the left middle frontal gyrus and right orbitofrontal cortex compared to HC (P<0.05, corrected. No difference on GMV was detected between medication-naïve MDD group and treated MDD group. CONCLUSIONS: This study of single episode, medication-naïve MDD subjects demonstrated structural abnormalities of frontal-subcortical circuitsin the early stage of MDD and the effects of 8 weeks successful antidepressant treatment, suggesting these abnormalities may play an important role in the neuropathophysiology of MDD at its onset.

Reionization of the Milky Way, M31, and their satellites - I. Reionization history and star formation

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Dixon, Keri L.; Iliev, Ilian T.; Gottlöber, Stefan; Yepes, Gustavo; Knebe, Alexander; Libeskind, Noam; Hoffman, Yehuda

2018-06-01

Observations of the Milky Way (MW), M31, and their vicinity, known as the Local Group (LG), can provide clues about the sources of reionization. We present a suite of radiative transfer simulations based on initial conditions provided by the Constrained Local UniversE Simulations (CLUES) project that are designed to recreate the Local Universe, including a realistic MW-M31 pair and a nearby Virgo. Our box size (91 Mpc) is large enough to incorporate the relevant sources of ionizing photons for the LG. We employ a range of source models, mimicking the potential effects of radiative feedback for dark matter haloes between {˜ }10^8 and 10^9 M_{⊙}. Although the LG mostly reionizes in an inside-out fashion, the final 40 per cent of its ionization shows some outside influence. For the LG satellites, we find no evidence that their redshift of reionization is related to the present-day mass of the satellite or the distance from the central galaxy. We find that fewer than 20 per cent of present-day satellites for MW and M31 have undergone any star formation prior to the end of global reionization. Approximately 5 per cent of these satellites could be classified as fossils, meaning the majority of star formation occurred at these early times. The more massive satellites have more cumulative star formation prior to the end of global reionization, but the scatter is significant, especially at the low-mass end. Present-day mass and distance from the central galaxy are poor predictors for the presence of ancient stellar populations in satellite galaxies.

Uygulamalı Bilimler ve Mühendislik

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Recep BAKIŞ

2011-12-01

Full Text Available Bu makalede, sanayi, tarım ve evsel atık sularla yoğun bir şekilde kirletilen Porsuk çayı ve havzasındaki yüzeysel ve yeraltı suyu kirlilik düzeyi araştırılmıştır. Bu amaçla, Porsuk çayı boyunca ve havza içinden 20 istasyon seçilerek, 2 yıl boyunca mevsimsel yüzeysel ve yeraltı su örnekleri alınmıştır. Yüzeysel sularda toplam 18, yeraltı sularında ise toplam 15 parametre analiz edilmiştir. Elde edilen sonuçlar, mevsimsel değişikliklerin sebebine bakılmaksızın, Su Kirliliği Kontrolü Yönetmeliği Kıta İçi Su Kaynakları sınıfları ve uluslar arası standartlarla karşılaştırılmıştır. Porsuk çayı ve havzasındaki hem yüzey suyunun hem de yeraltı suyunun IV. Kalite su sınıfında olduğu tespit edilmiştir

İçme ve sulama sularında bor kirliliği ve bor giderme yöntemleri

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Meltem Bilici Başkan

2014-03-01

Full Text Available Periyodik cetvelin 3A grubunda yer alan bor yüksek iyonlaşma potansiyeline sahip olması nedeniyle yarı metal olarak kabul edilir. Yerkabuğundaki ortalama bor konsantrasyonu 10 mg/kg'dır. Bor doğada Ca, Na ve Mg'un tuzları şeklinde bulunur. Yüksek konsantrasyonlarda ve ekonomik boyutlardaki bor yatakları; borun oksijen ile bağlanmış bileşikleri şeklinde daha çok Türkiye ve ABD'nin kurak, volkanik ve hidrotermal aktivitesi olan bölgelerinde bulunmaktadır. Bor, bitkiler için gerekli bir mikro besin elementi olmanın yanı sıra, gerekli tüm besin elementleri içerisinde, eksiklik belirtilerine neden olan miktarı ile toksik etki yapan miktarı, birbirine çok yakın olan tek elementtir. Bor su ortamında genellikle borik asit ve kısmen de borat tuzları formlarında bulunmaktadır. Pek çok endüstride kullanım alanı bulan bor bileşiklerinin endüstriyel gelişmelere bağlı olarak yüzeysel sularda bulunan konsantrasyonu artış göstermektedir. Yüzeysel sularda bulunan bor aynı zamanda evsel atıksulardan da kaynaklanmaktadır. Türkiye'de içme ve sulama sularını en çok kirleten toksik elementlerin başında bor gelmektedir. Bu nedenle bor giderimi hem insan sağlığı açısından hem de sağlıklı tarım ürünü yetiştirilebilmesi açısından oldukça önemlidir. Sulardan bor giderimi için uygulanan temel yöntemler arasında iyon değişimi, ultrafiltrasyon, ters osmoz ve adsorbsiyon gelmektedir.

Peripheral tissue homing receptor control of naïve, effector, and memory CD8 T cell localization in lymphoid and non-lymphoid tissues.

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Brinkman, C Colin; Peske, J David; Engelhard, Victor Henry

2013-01-01

T cell activation induces homing receptors that bind ligands on peripheral tissue vasculature, programing movement to sites of infection and injury. There are three major types of CD8 effector T cells based on homing receptor expression, which arise in distinct lymphoid organs. Recent publications indicate that naïve, effector, and memory T cell migration is more complex than once thought; while many effectors enter peripheral tissues, some re-enter lymph nodes (LN), and contain central memory precursors. LN re-entry can depend on CD62L or peripheral tissue homing receptors. Memory T cells in LN tend to express the same homing receptors as their forebears, but often are CD62Lneg. Homing receptors also control CD8 T cell tumor entry. Tumor vasculature has low levels of many peripheral tissue homing receptor ligands, but portions of it resemble high endothelial venules (HEV), enabling naïve T cell entry, activation, and subsequent effector activity. This vasculature is associated with positive prognoses in humans, suggesting it may sustain ongoing anti-tumor responses. These findings reveal new roles for homing receptors expressed by naïve, effector, and memory CD8 T cells in controlling entry into lymphoid and non-lymphoid tissues.

The Effects of Exercise on Expression of CYP19 and StAR mRNA in Steroid-Induced Polycystic Ovaries of Female Rats.

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Aghaie, Fatemeh; Khazali, Homayoun; Hedayati, Mehdi; Akbarnejad, Ali

2018-01-01

Polycystic ovarian syndrome (PCOS) is the most frequent female endocrine disorder that affects 5-10% of women. PCOS is characterized by hyperandrogenism, oligo-/anovulation, and polycystic ovaries. The aim of the present research is to evaluate the expression of steroidogenic acute regulatory protein (StAR) and aromatase (CYP19) mRNA in the ovaries of an estradiol valerate (EV)-induced PCOS rat model, and the effect of treadmill and running wheel (voluntary) exercise on these parameters. In this experimental study, we divided adult female Wistar rats that weighed approximately 220 ± 20 g initially into control (n=10) and PCOS (n=30). Subsequently, PCOS group were divided to PCOS, PCOS with treadmill exercise (P-ExT), and PCOS with running wheel exercise (P-ExR) groups (n=10 per group). The expressions of StAR and CYP19 mRNA in the ovaries were determined by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR). Data were analyzed by one-way ANOVA using SPSS software, version 16. The data were assessed at α=0.05. There was significantly lower mRNA expression of CYP19 in the EV-induced PCOS, running wheel and treadmill exercise rats compared to the control group (PStAR in the ovaries of the PCOS group indicated an increasing trend compared to the control group, however this was not statistically significant (P=0.810). We observed that 8 weeks of running wheel and treadmill exercises could not statistically decrease StAR mRNA expression compared to the PCOS group (P=0.632). EV-induced PCOS in rats decreased CYP19 mRNA expression, but had no effect on StAR mRNA expression. We demonstrated that running wheel and moderate treadmill exercise could not modify CYP19 and StAR mRNA expressions. Copyright© by Royan Institute. All rights reserved.

Retired A Stars and Their Companions. III. Comparing the Mass-Period Distributions of Planets Around A-Type Stars and Sun-Like Stars

Science.gov (United States)

Bowler, Brendan P.; Johnson, John Asher; Marcy, Geoffrey W.; Henry, Gregory W.; Peek, Kathryn M. G.; Fischer, Debra A.; Clubb, Kelsey I.; Liu, Michael C.; Reffert, Sabine; Schwab, Christian; Lowe, Thomas B.

2010-01-01

We present an analysis of ~5 years of Lick Observatory radial velocity measurements targeting a uniform sample of 31 intermediate-mass (IM) subgiants (1.5 lsim M */M sunlsim 2.0) with the goal of measuring the occurrence rate of Jovian planets around (evolved) A-type stars and comparing the distributions of their orbital and physical characteristics to those of planets around Sun-like stars. We provide updated orbital solutions incorporating new radial velocity measurements for five known planet-hosting stars in our sample; uncertainties in the fitted parameters are assessed using a Markov-Chain Monte Carlo method. The frequency of Jovian planets interior to 3 AU is 26+9 -8%, which is significantly higher than the 5%-10% frequency observed around solar-mass stars. The median detection threshold for our sample includes minimum masses down to {0.2, 0.3, 0.5, 0.6, 1.3} M Jup within {0.1, 0.3, 0.6, 1.0, 3.0} AU. To compare the properties of planets around IM stars to those around solar-mass stars we synthesize a population of planets based on the parametric relationship dN vprop M α P β dlnMdlnP, the observed planet frequency, and the detection limits we derived. We find that the values of α and β for planets around solar-type stars from Cumming et al. fail to reproduce the observed properties of planets in our sample at the 4σ level, even when accounting for the different planet occurrence rates. Thus, the properties of planets around A stars are markedly different than those around Sun-like stars, suggesting that only a small (~50%) increase in stellar mass has a large influence on the formation and orbital evolution of planets. Based on observations obtained at the Lick Observatory, which is operated by the University of California.

A study of the compact nebulae VV 8 and M3-27

International Nuclear Information System (INIS)

Adams, T.F.

1975-01-01

New photometric observations of the lines and continuum in the compact nebulae VV 8 and M3-27 are presented. The data for VV 8 are very similar to those obtained by O'Dell nearly 10 years ago. Both nebulae have high electron densities and are self-absorbed in Hα. Parameters describing the physical conditions are estimated using the observed Balmer and O iii line strengths. By comparing the observations with suitable models for young planetary nebulae, the abundances of helium, oxygen, and neon are shown to be normal. The N ii lines are stronger than predicted. The continuum in M3-27 is shown to be in good agreement with theory, while the continuum in VV 8 in the visible and infrared is much brighter than predicted. The similarity between the line spectra and inferred properties of the nebulae suggests that the optical continuum in VV 8 is unrelated to the nebula, and may come from a late-type companion in a binary. Serious difficulties remain, however, concerning the absolute magnitude and color of the companion in the binary model. Some implications of Zipoy's shell star model are also examined

The Ultraviolet Radiation Environment around M Dwarf Exoplanet Host Stars

Science.gov (United States)

France, Kevin; Froning, Cynthia S.; Linsky, Jeffrey L.; Roberge, Aki; Stocke, John T.; Tian, Feng; Bushinsky, Rachel; Desert, Jean-Michel; Mauas, Pablo; Mauas, Pablo;

THE ULTRAVIOLET RADIATION ENVIRONMENT AROUND M DWARF EXOPLANET HOST STARS

Energy Technology Data Exchange (ETDEWEB)

France, Kevin; Froning, Cynthia S.; Stocke, John T.; Bushinsky, Rachel [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Roberge, Aki [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Tian, Feng [Center for Earth System Sciences, Tsinghua University, Beijing 100084 (China); Desert, Jean-Michel [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Mauas, Pablo; Vieytes, Mariela [Instituto de Astronomsica del Espacio (CONICET-UBA), C.C. 67 Sucursal 28, 1428 Buenos Aires (Argentina); Walkowicz, Lucianne M., E-mail: kevin.france@colorado.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2013-02-15

The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the ultraviolet spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No 'UV-quiet' M dwarfs are observed. The bright stellar Ly{alpha} emission lines are reconstructed, and we find that the Ly{alpha} line fluxes comprise {approx}37%-75% of the total 1150-3100 A flux from most M dwarfs; {approx}>10{sup 3} times the solar value. We develop an empirical scaling relation between Ly{alpha} and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Ly{alpha}. The intrinsic unreddened flux ratio is F(Ly{alpha})/F(Mg II) = 10 {+-} 3. The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O{sub 2} and O{sub 3}, is shown to be {approx}0.5-3 for all M dwarfs in our sample, >10{sup 3} times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%-500% on 10{sup 2}-10{sup 3} s timescales. This effect should be taken into account in future UV

Van’da Tüketime Sunulan Feta Peynirlerinin Mikrobiyolojik ve Kimyasal Kalitesi

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Enise Akel

2016-11-01

Full Text Available Bu çalışma, Van il merkezinde tüketime sunulan Feta peynirlerinin mikrobiyolojik ve kimyasal kalitesini belirlemek amacıyla yapıldı. Çalışmada 50 adet Feta peyniri materyal olarak kullanıldı. Feta peynirlerinin mikrobiyolojik analizleri sonucunda, ortalama olarak toplam aerob mezofil genel canlı sayısı 5,49 log kob/g, laktik asit bakteri sayısı 5,20 log kob/g, koliform grubu mikroorganizma sayısı 0,78 log kob/g, Escherichia coli sayısı 0,10 log kob/g, mikrokok/stafilokok sayısı 0,58 log kob/g, koagülaz pozitif Staphylococcus aureus sayısı 0,53 log kob/g, Clostridium perfringens sayısı 0,08 log kob/g, enterobakteri sayısı 0,96 log kob/g, maya ve küf sayısı ise 5,18 log kob/g olarak saptandı. Kimyasal analizler sonucunda ise ortalama pH değeri 4,38, titre edilebilir asitlik derecesi %1,41 LA, kuru madde miktarı %41,21, yağ miktarı %18,12, kuru maddede yağ miktarı %44,18, tuz miktarı %8,36 ve kuru maddede tuz miktarı %20,42 olarak tespit edildi. Feta peyniri örneklerinin tamamı titre edilebilir asitlik yönünden standartlara uygun bulundu. Ancak örneklerin %8’i koagülaz pozitif S. aureus, %52’si pH ve %100’ü kuru maddede tuz yönünden standartlara uygun bulunmadı. Sonuç olarak, Feta peynirlerinin mikrobiyolojik ve kimyasal kalitesinin yetersiz olduğu ve bu durumun üretici ve tüketiciler için risk oluşturabileceği kanısına varıldı. Gıda zincirinin tüm aşamalarında temeli GMP olan HACCP sisteminin uygulanması gıda güvenliği, halk sağlığı ve tüketici haklarının korunmasında etkin rol oynayacaktır.

A M2FS Spectroscopic Study of Low-mass Young Stars in Orion OB1

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Kaleida, Catherine C.; Briceno, Cesar; Calvet, Nuria; Mateo, Mario L.; Hernandez, Jesus

2015-01-01

Surveys of pre-main sequence stars in the ~4-10 Myr range provide a window into the decline of the accretion phase of stars and the formation of planets. Nearby star clusters and stellar associations allow for the study of these young stellar populations all the way down to the lowest mass members. One of the best examples of nearby 4-10 Myr old stellar populations is the Orion OB1 association. The CIDA Variability Survey of Orion OB1 (CVSO - Briceño et al. 2001) has used the variability properties of low-mass pre-main-sequence (PMS) stars to identify hundreds of K and M-type stellar members of the Orion OB1 association, a number of them displaying IR-excess emission and thought to be representative of more evolved disk-bearing young stars. Characterizing these young, low-mass objects using spectroscopy is integral to understanding the accretion phase in young stars. We present preliminary results of a spectroscopic survey of candidate and confirmed Orion OB1 low-mass members taken during November 2014 and February 2014 using the Michigan/Magellan Fiber Spectrograph (M2FS), a PI instrument on the Magellan Clay Telescope (PI: M. Matteo). Target fields located in the off-cloud regions of Orion were identified in the CVSO, and observed using the low and high-resolution modes of M2FS. Both low and high-resolution spectra are needed in order to confirm membership and derive masses, ages, kinematics and accretion properties. Initial analysis of these spectra reveal many new K and M-type members of the Orion OB1 association in these low extinction, off-cloud areas. These are the more evolved siblings of the youngest stars still embedded in the molecular clouds, like those in the Orion Nebula Cluster. With membership and spectroscopic indicators of accretion we are building the most comprehensive stellar census of this association, enabling us to derive a robust estimate of the fraction of young stars still accreting at a various ages, a key constraint for the end of

USING Hα MORPHOLOGY AND SURFACE BRIGHTNESS FLUCTUATIONS TO AGE-DATE STAR CLUSTERS IN M83

International Nuclear Information System (INIS)

Whitmore, Bradley C.; Mutchler, Max; Stankiewicz, Matt; Bond, Howard E.; Chandar, Rupali; Kim, Hwihyun; Kaleida, Catherine; Calzetti, Daniela; Saha, Abhijit; O'Connell, Robert; Balick, Bruce; Carollo, Marcella; Disney, Michael J.; Dopita, Michael A.; Frogel, Jay A.; Hall, Donald N. B.; Holtzman, Jon A.; Kimble, Randy A.; McCarthy, Patrick J.; Paresce, Francesco

2011-01-01

We use new WFC3 observations of the nearby grand-design spiral galaxy M83 to develop two independent methods for estimating the ages of young star clusters. The first method uses the physical extent and morphology of Hα emission to estimate the ages of clusters younger than τ ∼ 10 Myr. It is based on the simple premise that the gas in very young (τ V 10 Myr) clusters. A by-product of this study is the identification of 22 'single-star' H II regions in M83, with central stars having ages ∼4 Myr.

The September 2017 M=8.1 Chiapas and M=7.1 Puebla, Mexico, earthquakes: Chain reaction or coincidence?

Science.gov (United States)

Toda, S.; Stein, R. S.

2017-12-01

The M=8.1 and M=7.1 events struck 12 days and 600 km apart, both with an independent probability of occurrence of 0.5% per year, based on the GEAR model [Bird et al., 2015]. Are they related? First, we calculated the static stress imparted by the M=8.1 shock to the fault that ruptured in the M=7.1, and find a tiny push that would favor rupture. But the stress increase (0.2 kPa) is less than the fault would experience from the tidal stresses, and so it should be inconsequential. We next used the México Servicio Sismológico Nacional (UNAM) online catalog to look at the quakes in the month before the M=8.1 and in the 13 days since. We calculate the completeness to be M≥4.0. There are virtually no remote aftershocks from the Chiapas rupture that extend within 250 km of the M=7.1 shock during the first week after the M=8.1. So, if anything, the M=8.1 turned off for a week or more the region that ruptured in the M=7.1. Events started turning on about 2-3 days before the M=7.1, but none of those struck within 40 km of the future M=7.1 mainshock. The seismic surface waves unleashed by great earthquakes envelop the globe in just 160 minutes, and yet triggering of remote large aftershocks during these 2-3 hours is either very rare [Pollitz et al., Nature 2012] or in dispute [Fan & Shearer, 2016 vs. Yue et al., 2017]. So, the waves must trigger tiny shocks that cascade into larger shocks after some delay. Or, perhaps the stresses conveyed by the waves pump pockets of fluids that slowly diffuse into nearby fault zones, lubricating them to the point of failure [Parsons at al., 2017]. In the cases where great earthquakes are indisputably seen to trigger aftershocks at great distances or even globally, they to do so within several days, or a week at most. Since Puebla struck 12 days later, this seems to us too long a period to be explained by dynamic triggering. Even though neither quake on their own is rare, what's the chance of independent M=8.1 and M=7.1 events just 12

Soğukta ve Dondurulmuş Halde Muhafazaları Esnasında Meyve ve Sebzelerin Kalite ve Besleyici Değerlerinde Meydana Gelen Değişiklikler

Directory of Open Access Journals (Sweden)

Osman Cabı

2015-02-01

Full Text Available Kolay bozulabilir gıda maddelerinin daha uzun süre muhafaza edilmeleri amacıyla soğutma yönteminin kullanılmasının geçmişi tarih öncesi zamanlara kadar uzanmaktadır. Adı geçen “muhafaza” veya “korunma” sözcüğü, Weiser ve ark. 1971 tarafından, bir gıda maddesinin fiziksel, kimyasal kalitelerinin ve besleyici özelliklerinin belli bir süre müddetince veya mümkün olduğu kadar uzun bir periyot süresince saklanması şeklinde tanımlanmaktadır. Soğuğun çeşitli uygulamalarıyla muhafaza edilen gıda maddeleri gerek kantite gerekse çeşit ve yapı olarak geçtiğimiz son yıllarda büyük bir artış göstermişlerdir. İki yıl önceki değerlendirmelere göre, dünya kolay bozulabilir gıda maddeleri üretiminin 1 milyar ton olduğu Anquez, M. 1975 ve bu miktarın dörtte birinin (250 milyon ton herhangi bir şekilde işlenmesinde soğuğun kullanıldığı kabul edilmektedir.

Stability of extended scalar diquark stars vis-à-vis soliton stars

Indian Academy of Sciences (India)

Motivated by relatively large values of the maximum mass ( M = 8 : 92 M ⊙ ) and radius ( = 50.7 km) obtained for an extended scalar diquark star within the framework of an effective 4-theory (S K Karn et al [1]) some interesting observations are made with regard to the stability of stellar objects describable in general in ...

Kavunda ebeveyn hat ile melezlerinin bazı tohum ve tohum çıkışı özelliklerinin belirlenmesi

OpenAIRE

TUR, Ayşegül; SEYMEN, Musa; TÜRKMEN, Önder

2018-01-01

Bu çalışma, 2015-2016 yıllarında yürütülmüş ve bitkisel materyal olarak, 13 genotip (SÇ-1: Sel-1-1. SÇ-2: Sel-1-2. SÇ-3: Sel-2. SÇ-4: Sel-3. SÇ-5: Sel-4. SÇ-6: Sel-6-1. SÇ-7: Sel-6-2. SÇ-8: Sel-7. SÇ-9: Sel-8. SÇ-10: Sel-9. SÇ-11: Sel-10. SÇ-12: Sel-11. SÇ-13: Pop. Diyarbakır). 4 ebeveyn hat (EB-1: saf hat-7. EB-2: saf hat-A4. EB-3: saf hat-G22. EB-4: saf hat-136) ve 9 melez (M-1: safhat 7xsafhat-136. M-2: safhat-7xsafhat-A4. M-3: safhat-7xsafhat-G22. M-4: safhat-G22xsafhat-136. M-5: safhat-G...

THE NEAR-ULTRAVIOLET LUMINOSITY FUNCTION OF YOUNG, EARLY M-TYPE DWARF STARS

International Nuclear Information System (INIS)

Ansdell, Megan; Baranec, Christoph; Gaidos, Eric; Mann, Andrew W.; Lépine, Sebastien; James, David; Buccino, Andrea; Mauas, Pablo; Petrucci, Romina; Law, Nicholas M.; Riddle, Reed

2015-01-01

Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magnetohydrodynamic dynamos during stellar youth. Near-ultraviolet (NUV) irradiation can erode and alter the chemistry of planetary atmospheres, and a quantitative description of the evolution of NUV emission from M dwarfs is needed when modeling these effects. We investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lépine and Gaidos catalog of bright M dwarfs with the Galaxy Evolution Explorer (GALEX) catalog of NUV (1771-2831 Å) sources. Of the 4805 sources with GALEX counterparts, 797 have NUV emission significantly (>2.5σ) in excess of an empirical basal level. We inspected these candidate active stars using visible-wavelength spectra, high-resolution adaptive optics imaging, time-series photometry, and literature searches to identify cases where the elevated NUV emission is due to unresolved background sources or stellar companions; we estimated the overall occurrence of these ''false positives'' (FPs) as ∼16%. We constructed an NUV luminosity function that accounted for FPs, detection biases of the source catalogs, and GALEX upper limits. We found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplified age-activity relation defined by a two-parameter power law

THE NEAR-ULTRAVIOLET LUMINOSITY FUNCTION OF YOUNG, EARLY M-TYPE DWARF STARS

Energy Technology Data Exchange (ETDEWEB)

Ansdell, Megan; Baranec, Christoph [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822 (United States); Mann, Andrew W. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Lépine, Sebastien [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302 (United States); James, David [Cerro Tololo Inter-American Observatory, Casilla 603 La Serena (Chile); Buccino, Andrea; Mauas, Pablo; Petrucci, Romina [Instituto de Astronomía y Física del Espacio, C1428EHA Buenos Aires (Argentina); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Riddle, Reed [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

2015-01-01

Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magnetohydrodynamic dynamos during stellar youth. Near-ultraviolet (NUV) irradiation can erode and alter the chemistry of planetary atmospheres, and a quantitative description of the evolution of NUV emission from M dwarfs is needed when modeling these effects. We investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lépine and Gaidos catalog of bright M dwarfs with the Galaxy Evolution Explorer (GALEX) catalog of NUV (1771-2831 Å) sources. Of the 4805 sources with GALEX counterparts, 797 have NUV emission significantly (>2.5σ) in excess of an empirical basal level. We inspected these candidate active stars using visible-wavelength spectra, high-resolution adaptive optics imaging, time-series photometry, and literature searches to identify cases where the elevated NUV emission is due to unresolved background sources or stellar companions; we estimated the overall occurrence of these ''false positives'' (FPs) as ∼16%. We constructed an NUV luminosity function that accounted for FPs, detection biases of the source catalogs, and GALEX upper limits. We found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplified age-activity relation defined by a two-parameter power law.

ISO-SWS spectrophotometry of galactic Wolf-Rayet stars: preliminary results.

NARCIS (Netherlands)

van der Hucht, K. A.; Morris, P. W.; Williams, P. M.; Setia Gunawan, D. Y. A.; Beintema, D. A.; Boxhoorn, D. R.; de Graauw, T.; Heras, A.; Kester, D. J. M.; Lahuis, F.; Leech, K. J.; Roelfsema, P. R.; Salama, A.; Valentijn, E. A.; Vandenbussche, B.

1996-01-01

ISO-SWS spectra of seven late-type galactic Wolf-Rayet stars are discussed. A high resolution spectrum (2.3-29.6μm, λ/{DELTA}λ=~820-1700) of the WC8 star WR11 (γ^2^ Vel) is shown and its Ne abundance is discussed. Medium resolution spectra (λ/{DELTA}λ=~250-600) of the WC8-9 stars WR48a, WR98a,

Optical photometry and spectroscopy for five dwarf M stars

Energy Technology Data Exchange (ETDEWEB)

Doyle, J.G.; Byrne, P.B.; Menzies, J.W.

1986-05-01

A search for flaring and BY Dra (spotted) variations on five M-dwarf stars, Gliese 1, 461, 825, 899 and 908 is reported. The results for Gl 461 and 825 are compared with predictions of activity levels based on the measured quiescent X-ray flux. The chromospheric radiative loss rate in the Ca H and K lines are determined for Gl 461.

ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

Energy Technology Data Exchange (ETDEWEB)

Berger, E.; Zauderer, B. A.; Chary, R.-R.; Laskar, T.; Chornock, R.; Davies, J. E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Stanway, E. R.; Levan, A. J. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Levesque, E. M. [CASA, University of Colorado UCB 389, Boulder, CO 80309 (United States)

2014-12-01

We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F {sub ν}(222 GHz) ≲ 33 μJy and F {sub ν}(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L {sub IR}(8-1000 μm) ≲ 3 × 10{sup 10} L {sub ☉}, corresponding to a limit on the obscured star formation rate of SFR{sub IR}≲5 M {sub ☉} yr{sup –1}. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFR{sub UV} ≲ 1 M {sub ☉} yr{sup –1}. We also place a limit on the host galaxy stellar mass of M {sub *} ≲ 5 × 10{sup 7} M {sub ☉} (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

Süryaniler’in Tarihi ve Sosyolojik Yapısı

OpenAIRE

Ürek, Melki

2014-01-01

Bu makalede, Süryanilerin tarihi süreçleri ve sosyolojik yapıları ele alın-mıştır. Süryaniler yüzyıllar boyunca oldukça kaotik bir cooğrafyada yaşa-mışlarddır. Bu nedenle, dini, politik ve ideolojik açıdan pek çok farklı pa-radigmanın etkisi altında kalmışlardır. Bu olumsuz etki Süryanileri tarihi ve teolojik açıdan hatalı tanımlamalar ve yanlış isimlendirmeler gibi so-runlarla yüz yüze bırakmıştır. Ancak son zamanlarda üretilen akademik ve objektif çalışmalarla, Süryani liderlerin kendilerin...

Late stages of massive star evolution and nucleosynthesis

International Nuclear Information System (INIS)

Nomoto, Ken'ichi; Hashimoto, Masa-aki.

1986-01-01

The evolution of massive stars in the mass range of 8 to 25 M solar mass is reviewed. The effect of electron degeneracy on the gravothermal nature of stars is discussed. Depending on the stellar mass, the stars form three types of cores, namely, non-degenerate, semi-degenerate, and strongly degenerate cores. The evolution for these cases is quite distinct from each other and leads to the three different types of final fate. It is suggested that our helium star model, which is equivalent to a 25 M solar mass star, will form a relatively small mass iron core despite the faster 12 C(α,γ) 16 O reaction. 50 refs., 21 figs

Feminist Sanatta Beden ve Yabancılaşma

OpenAIRE

Alp, Kafiye Özlem

2015-01-01

Feminizm, eril bir toplumda kadının, eşit hak ve özgürlüklere sahip olma gerekçelerine dayalı bir mücadele alanı olarak tanımlanabilir. Feminizmin, kamusal ve özel alanda kadın ayrımcılığına karşı başkaldırısı, insanın kendi emeğine ve kendi bedenine olan yabancılaşmasının bir sonucudur. Bu bakımdan feminizm, tüm tarihi boyunca toplumsal, felsefi, cinsel ve psikanalitik yabancılaşma kavramlarıyla yakın ilgi içinde olmuştur. Feminist sanat pratikleri; feminist kuramlar, toplumsal dinamikler...

Monitoring of local CD8 β-expressing cell populations during Eimeria tenella infection of naïve and immune chickens

DEFF Research Database (Denmark)

Wattrang, Eva; Thebo, Per; Lunden, Anna

2016-01-01

The purpose of this study was to monitor abundance and activation of local CD8β-expressing T-cell populations during Eimeria tenella infections of naïve chickens and chickens immune by previous infections. Chickens were infected with E. tenella up to three times. Caecal T-cell receptor (TCR) γ...

Turist Motivasyonunda Mahalli Kültür ve Etkisi ve Apart Ziyaretlerinde Turist Memnuniyeti

Directory of Open Access Journals (Sweden)

Nguyen Quang VINH

2013-09-01

Full Text Available Bu çalışma, apart turizm hizmet sektöründe stratejik pazarlama kararının tesis edilmesi anlayışını sağlamak için turizm planlamacılarına ve turizmcilere yardım etmeyi amaçlamaktadır. Ampirik analiz için Duonglam Eski Köyü’nün apart hizmetinden faydalanmış 150 uluslararası ziyaretçinin oluşturduğu datalar kullanılmıştır. Turist motivasyonu ve nihai varış noktası sadakatindeki memnuniyet arasındaki hipotezleri test etmek amacıyla regresyon yöntemi benimsenmiştir. Bu çalışma Duonglam köyündeki iklim şartları, nihai varış noktasına ulaşım kolaylığı, konaklama kalitesi, doğal güzellikler ve hijyen şartlarının turist memnuniyeti üzerinde önemli etkileri olduğu sonucunu çıkarmıştır. Diğer taraftan da bu sonuçlar Duonglam Eski Köyü’nün kültürel aktiviteleri ve turizm hizmet sektörü hakkında olumsuz bir kanıyı temsil etmektedir. Ayrıca çalışmada, araştırmanın sınırı ve turizm sektörü çalışanları için elde edilen bulguların sonuçları tartışılmıştır.

The radius of the quiescent neutron star in the globular cluster M13

Science.gov (United States)

Shaw, A. W.; Heinke, C. O.; Steiner, A. W.; Campana, S.; Cohn, H. N.; Ho, W. C. G.; Lugger, P. M.; Servillat, M.

2018-06-01

X-ray spectra of quiescent low-mass X-ray binaries containing neutron stars can be fit with atmosphere models to constrain the mass and the radius. Mass-radius constraints can be used to place limits on the equation of state of dense matter. We perform fits to the X-ray spectrum of a quiescent neutron star in the globular cluster M13, utilizing data from ROSAT, Chandra, and XMM-Newton, and constrain the mass-radius relation. Assuming an atmosphere composed of hydrogen and a 1.4 M⊙ neutron star, we find the radius to be R_NS=12.2^{+1.5}_{-1.1} km, a significant improvement in precision over previous measurements. Incorporating an uncertainty on the distance to M13 relaxes the radius constraints slightly and we find R_NS=12.3^{+1.9}_{-1.7} km (for a 1.4M⊙ neutron star with a hydrogen atmosphere), which is still an improvement in precision over previous measurements, some of which do not consider distance uncertainty. We also discuss how the composition of the atmosphere affects the derived radius, finding that a helium atmosphere implies a significantly larger radius.

Formation of a contact binary star system

International Nuclear Information System (INIS)

Mullen, E.F.F.

1974-01-01

The process of forming a contact binary star system is investigated in the light of current knowledge of the W Ursae Majoris type eclipsing binaries and the current rotational braking theories for contracting stars. A preliminary stage of mass transfer is proposed and studied through the use of a computer program which calculates evolutionary model sequences. The detailed development of both stars is followed in these calculations, and findings regarding the internal structure of the star which is receiving the mass are presented. Relaxation of the mass-gaining star is also studied; for these stars of low mass and essentially zero age, the star eventually settles to a state very similar to a zero-age main sequence star of the new mass. A contact system was formed through these calculations; it exhibits the general properties of a W Ursae Majoris system. The initial masses selected for the calculation were 1.29 M/sub solar mass/ and 0.56 M/sub solar mass/. An initial mass transfer rate of about 10 -10 solar masses per year gradually increased to about 10 -8 solar masses per year. After about 2.5 x 10 7 years, the less massive star filled its Roche lobe and an initial contact system was obtained. The final masses were 1.01359 M/sub solar mass/ and 0.83641 M/sub solar mass/. The internal structure of the secondary component is considerably different from that of a main sequence star of the same mass

Haberleşmenin gizliliğini ihlal ve özel hayatın gizliliğini ihlal suçları(TCK m.132-134)

OpenAIRE

GEÇMEZ, Taner

2014-01-01

İnsanların toplumsal hayatın birer parçası olması, kişiden kişiye farklılık arzetmekle birlikte, diğer kişilerle ilişki içinde bulunmalarını zorunlu kılmaktadır. Bu ilişkiler dolayısıyla kişilerin hayatlarının belli yönlerinin diğer kişiler tarafından öğrenilmesive algılanması kaçınılmaz hâle gelmektedir. Geldiğimiz noktada bilgi ve iletişim teknolojilerinde meydana gelen ve takip edilmesi neredeyse mümkün olmayan gelişmeler, öğrenme ve algılama şeklindeki bu tarz müdahaleleri fazlas...

ÇOCUKLARDA ÖLÜM VE YAS ÜZERİNE BİR İNCELEME

Directory of Open Access Journals (Sweden)

Emre Ürer

2017-12-01

Full Text Available Yas, kişinin bir yakınının ya da sevdiği bir nesnenin kaybına karşı verdiği tepkilerin bütününü içeren düşünce, duygu ve davranış sürecidir. Çocuklarda yas reaksiyonlarının görülüş şekli yaştan ya da çocuğun bilişsel gelişim kapasitesinden bağımsız düşünülemez. Çocukta zamanla ölüm, kayıp kavramları oturmakta, soyut algı geliştikçe de erişkin tipi yas reaksiyonundan söz edilebilmektedir. Çocuklar ölüm ya da kayıp karşısında çok çeşitli tepkiler verir. Erişkinlerde olduğu gibi çocuklarda da yas sürecini komplike eden faktörler bulunmaktadır. Bu faktörler arasında kişi ya da nesnenin kaybediliş şeklinden, kayıp sonrasındaki psikososyal destek sistemlerinin yeterliliği gibi çok çeşitli nedenler sayılabilir. Hayatta kalan ebeveyn ya da bakım verenin yas sürecini sağlıklı geçirmesi çocuğun yas sürecini de doğrudan etkileyecektir. Yas süreci komplike olduğunda ya da aile içi destek sistemlerinde eksiklikler hissedildiğinde, bu konuda çocuk ruh sağlığı profesyonellerinden destek istenmelidir. Bu yazıda çocuklardaki yas kavramını ve ölüm ya da nesne kaybıyla karşılaşan çocuğa nasıl yaklaşılması gerektiği konusunda bilgiler vermeyi amaçladık.

Evolution of S stars in the Magellanic Clouds

International Nuclear Information System (INIS)

Evans, T.L.

1984-01-01

Early S stars occur between M and C stars in the colour magnitude diagrams of intermediate age globular clusters in the Magellanic Clouds. Most have -4.2 >= Msub(bol) >= -4.8 and are probably brighter in younger or more metal rich clusters. The galactic globular cluster NGC 6723 contains two marginal S stars at Msub(bol) approx. -3.3. The rare CS stars have Msub(bol) approx. -6, with no faint examples. (Auth.)

Kontrol Sistemleri dersi için Matlab Builder Ne ve Asp.net tabanlı web laboratuarı tasarımı

Directory of Open Access Journals (Sweden)

Eyüp Sönmez

2016-08-01

Full Text Available Mühendislik alanında sistemleri test etmek için kullanılan yazılımların öğrenilmesi ve uygulanması zaman kaybına ve asıl amaçtan uzaklaşılmasına neden olmaktadır. Bu çalışmada lisans düzeyinde okutulan Kontrol Sistemleri dersi için internet tabanlı bir arayüz tasarlanmıştır. Hazırlanan kullanıcı arayüzü ile kullanıcıların derin matematik ve programlama bilgisine ihtiyaç duymadan, sistemlerin analiz ve kontrolünü yapabilmesi; ayrıca arayüzün web tabanlı tasarlanmasıyla, yöntemin yaygınlaştırılması, zaman kaybını ortadan kaldırarak birden fazla kullanıcının eş zamanlı kullanabilmesi amaçlanmıştır. Web tabanlı arayüz tasarımı için MATLAB Web Figure ile ASP.NET platformu kullanılmıştır. Aynı zamanda arayüzde yapılan işlemlere ait pratik bilgilere de ulaşılabilmektedir. Böylece hem eğitimsel hem de akademik amaçlara uygun bir sanal laboratuar tasarımı gerçekleştirilmiştir.

NuSTAR J033202-2746.8: Direct constraints on the Compton reflection in a heavily obscured quasar at z ≈ 2

Energy Technology Data Exchange (ETDEWEB)

Del Moro, A.; Mullaney, J. R.; Alexander, D. M.; Aird, J. A.; Gandhi, P. [Department of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Comastri, A.; Vignali, C.; Gilli, R. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Bauer, F. E. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Treister, E. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Civano, F. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Ranalli, P. [National Observatory of Athens, Institute of Astronomy, Astrophysics, Space Applications and Remote Sensing, Metaxa and Pavlou St., 15236 Penteli (Greece); Ballantyne, D. R. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Baloković, M. [Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, CA 91125 (United States); Boggs, S. E. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Craig, W. W. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Hailey, C. J., E-mail: agnese.del-moro@durham.ac.uk [Columbia Astrophysics Laboratory, 550 W 120th Street, Columbia University, NY 10027 (United States); and others

2014-05-01

We report Nuclear Spectroscopic Telescope Array (NuSTAR) observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (∼400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably detected by NuSTAR only at E > 8 keV and has a very flat spectral slope in the NuSTAR energy band (Γ=0.55{sub −0.64}{sup +0.62}; 3-30 keV). Combining the NuSTAR data with extremely deep observations by Chandra and XMM-Newton (4 Ms and 3 Ms, respectively), we constrain the broad-band X-ray spectrum of NuSTAR J033202-2746.8, indicating that this source is a heavily obscured quasar (N{sub H}=5.6{sub −0.8}{sup +0.9}×10{sup 23} cm{sup –2}) with luminosity L {sub 10-40} {sub keV} ≈ 6.4 × 10{sup 44} erg s{sup –1}. Although existing optical and near-infrared (near-IR) data, as well as follow-up spectroscopy with the Keck and VLT telescopes, failed to provide a secure redshift identification for NuSTAR J033202-2746.8, we reliably constrain the redshift z = 2.00 ± 0.04 from the X-ray spectral features (primarily from the iron K edge). The NuSTAR spectrum shows a significant reflection component (R=0.55{sub −0.37}{sup +0.44}), which was not constrained by previous analyses of Chandra and XMM-Newton data alone. The measured reflection fraction is higher than the R ∼ 0 typically observed in bright radio-loud quasars such as NuSTAR J033202-2746.8, which has L {sub 1.4} {sub GHz} ≈ 10{sup 27} W Hz{sup –1}. Constraining the spectral shape of active galactic nuclei (AGNs), including bright quasars, is very important for understanding the AGN population, and can have a strong impact on the modeling of the X-ray background. Our results show the importance of NuSTAR in investigating the broad-band spectral properties of quasars out to high redshift.

Tedrici Azalan Sıcaklığın Pimpla turionellae (Hymenoptera: Ichneumonidae’ nın Ömür Uzunluğuna ve Yumurta Verimine Etkileri

Directory of Open Access Journals (Sweden)

Rahile ÖZTÜRK

2017-06-01

Full Text Available Bu çalışmada, laboratuvar şartlarında Galleria mellonella L. (Lepidoptera: Pyralidae puplarında yetiştirilen endoparazitoid Pimpla turionellae L. (Hymenoptera: Ichneumonidae’ nın larval evresine, konak içinde uygulanan tedrici azalan sıcaklığın etkileri araştırılmıştır. Parazitlenen konak pupları sırasıyla 25, 20, 15 ve 10°C’ lerde 3’ er gün, 4°C’ de 2, 3, 4 ve 5’ er gün bekletilmiştir. Uygulamalar sonucunda çıkan bireylerin ergin ömür uzunlukları ve dişilerin yumurta verimi araştırılmıştır. Elde edilen sonuçlara göre, 4°C’ de bekletme süresinin artması ile ömür uzunluğu ve yumurta verimi azalmıştır.

Chemical Analysis of Asymptotic Giant Branch Stars in M62

NARCIS (Netherlands)

Lapenna, E.; Mucciarelli, A.; Ferraro, F. R.; Origlia, L.; Lanzoni, B.; Massari, D.; Dalessandro, E.

2015-01-01

We have collected UVES-FLAMES high-resolution spectra for a sample of 6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the Galactic globular cluster (GC) M62 (NGC 6266). Here we present the detailed abundance analysis of iron, titanium, and light elements (O, Na, Mg, and Al).

Autoimmune vitiligo does not require the ongoing priming of naïve CD8 T cells for disease progression or associated protection against melanoma1

Science.gov (United States)

Byrne, Katelyn T.; Zhang, Peisheng; Steinberg, Shannon M.; Turk, Mary Jo

2014-01-01

Vitiligo is a CD8 T cell-mediated autoimmune disease that has been shown to promote the longevity of memory T cell responses to melanoma. However mechanisms whereby melanocyte/melanoma antigen-specific T cell responses are perpetuated in the context of vitiligo are not well understood. The present studies investigate the possible phenomenon of naïve T cell priming in hosts with melanoma-initiated, self-perpetuating, autoimmune vitiligo. Using naïve pmel (gp10025-33-specific) transgenic CD8 T cells, we demonstrate that autoimmune melanocyte destruction induces naive T cell proliferation in skin-draining lymph nodes, in an antigen-dependent fashion. These pmel T cells upregulate expression of CD44, P-selectin ligand, and granzyme B. However, they do not downregulate CD62L, nor do they acquire the ability to produce IFN-γ, indicating a lack of functional priming. Accordingly, adult thymectomized mice exhibit no reduction in the severity or kinetics of depigmentation or long-lived protection against melanoma, indicating that the continual priming of naïve T cells is not required for vitiligo or its associated anti-tumor immunity. Despite this, depletion of CD4 T cells during the course of vitiligo rescues the priming of naïve pmel T cells that are capable of producing IFN-γ and persisting as memory, suggesting an ongoing and dominant mechanism of suppression by regulatory T cells. This work reveals the complex regulation of self-reactive CD8 T cells in vitiligo, and demonstrates the overall poorly immunogenic nature of this autoimmune disease setting. PMID:24403535

H α AS A LUMINOSITY CLASS DIAGNOSTIC FOR K- AND M-TYPE STARS

International Nuclear Information System (INIS)

Jennings, Jeff; Levesque, Emily M.

2016-01-01

We have identified the H α absorption feature as a new spectroscopic diagnostic of luminosity class in K- and M-type stars. From high-resolution spectra of 19 stars with well-determined physical properties (including effective temperatures and stellar radii), we measured equivalent widths for H α and the Ca ii triplet and examined their dependence on both luminosity class and stellar radius. H α shows a strong relation with both luminosity class and radius that extends down to late M spectral types. This behavior in H α has been predicted as a result of the density-dependent overpopulation of the metastable 2s level in hydrogen, an effect that should become dominant for Balmer line formation in non-LTE conditions. We conclude that this new metallicity-insensitive diagnostic of luminosity class in cool stars could serve as an effective means of discerning between populations such as Milky Way giants and supergiant members of background galaxies.

H α AS A LUMINOSITY CLASS DIAGNOSTIC FOR K- AND M-TYPE STARS

Energy Technology Data Exchange (ETDEWEB)

Jennings, Jeff [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Levesque, Emily M., E-mail: emsque@uw.edu [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)

2016-04-20

We have identified the H α absorption feature as a new spectroscopic diagnostic of luminosity class in K- and M-type stars. From high-resolution spectra of 19 stars with well-determined physical properties (including effective temperatures and stellar radii), we measured equivalent widths for H α and the Ca ii triplet and examined their dependence on both luminosity class and stellar radius. H α shows a strong relation with both luminosity class and radius that extends down to late M spectral types. This behavior in H α has been predicted as a result of the density-dependent overpopulation of the metastable 2s level in hydrogen, an effect that should become dominant for Balmer line formation in non-LTE conditions. We conclude that this new metallicity-insensitive diagnostic of luminosity class in cool stars could serve as an effective means of discerning between populations such as Milky Way giants and supergiant members of background galaxies.

Synthesis and Characterization of Well-Defined Regular Star Polyisoprenes with 3, 4, 6 and 8 Arms

KAUST Repository

Ratkanthwar, Kedar R.; Hadjichristidis, Nikolaos; Pudukulathan, Zubaidha

2013-01-01

Three series of regular well-defined star polyisoprenes (PIs) with 3, 4 and 6 arms (each series: same arm molecular weight) have been synthesized by anionic polymerization high vacuum techniques and chlorosilane chemistry. In addition, three linear PIs with practically the double arm molecular weight of the corresponding series (2-arm star PIs) have been synthesized, as well as one 8-arm star PI. All intermediate (arms) and final (stars) products have been characterized by size exclusion chromatography (SEC), SEC-multi-angle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. The Tg of the star PIs was determined by differential scanning calorimetry. These model polymeric materials are essential for polymer physics and polymer physical chemistry in order to establish the structure/property relationships.

Kültüre alınan salep orkidelerinde yabancı otlarla mücadelede kimyasal ve mekanik yöntemlerin etkinliğinin belirlenmesi

Directory of Open Access Journals (Sweden)

Yrd.Doç.Dr. Salih PARLAK

2016-12-01

Full Text Available Ülkemizde 30’u endemik 170 takson ile temsil edilen salep orkideleri bitki çeşitliliği içerisinde genetik zenginliğimizin önemli bir parçası olması yanı sıra ekonomik ve ticari değeri olan türleri de barındırmaktadır. “Nesli Tehlike Altında Olan Yabani Hayvan ve Bitki Türlerinin Uluslararası Ticaretine İlişkin Sözleşme" (CITIES” kapsamında oldukları halde salep elde etmek üzere her yıl doğadan milyonlarca adet sökülmektedir. Elde edilen salep başta dondurma endüstrisi olmak üzere gıda sektöründe kullanılmaktadır. Ekonomik değeri yüksek bir ürün olmasına rağmen kültüre alma çalışmaları halen devam etmektedir. Yabancı ot kontrolü, kültüre alma çalışmaları sırasında karşılaşılan ve maliyetleri önemli ölçüde arttıran bir etmen olarak karşımıza çıkmaktadır. Bu çalışmada hem mekanik hem de kimyasal mücadele olanakları araştırılmış ve kültür yetiştiriciliğinde ucuz ve etkili bir yöntem tespit edilmeye çalışılmıştır. İzmir’in Menemen ilçesi tarla şartlarında 2010 yılında gerçekleştirilen çalışmada farklı etken maddelere sahip herbisitler kullanılarak kimyasal mücadelenin etkinliği belirlenmeye çalışılmıştır. Bu maksatla 2010 yılı eylül ayının 3. haftasında yapılan yumru ekimlerinden sonra çıkış öncesi önerilen dozda Lenacil (Adol, Bentazon (Basagran, Acetochlor (Cengaver, Aclonifen (Challenge, Pendimethalin (Herbimat, Trifluralin (Treflan ve kontrol olmak üzere yedi işlem üç tekerrürlü olarak uygulanmıştır. Uygulamadan sonra kullanılan etken maddeler kontrole göre metrekaredeki yabancı ot sayısında; Lenacil etkisiz, Bentazon % 54, Trifluralin % 71, Acetochlor % 95, Aclonifen % 97, Pendimethalin % 93 oranında azalttığı belirlenmiştir. Bununla birlikte Trifluralin, Acetochlor ve Aclonifen’in salep bitkilerinin gelişmesini de olumsuz etkilediği gözlenmiş, hem yabancı ot kontrolü, hemde salep

Damla Sulama Koşullarında Aşılı ve Aşısız Karpuzlarda Bitki, Su ve Verim İlişkilerinin İrdelenmesi

Directory of Open Access Journals (Sweden)

Selçuk ÖZMEN

2014-09-01

Full Text Available Bu çalışma, 2006-2008 yılları arasında Çukurova Üniversitesi, Ziraat Fakültesi, Tarımsal Yapılar ve Sulama Bölümü deneme alanında yürütülmüştür. Araştırmada, damla sulama koşullarında aşılı ve aşısız karpuzlarda bitki, su ve verim ilişkileri irdelenmiştir. Denemede; tam sulanan aşılı (Crimson Tide+Jumbo:CTJ ve aşısız (Crimson Tide: CT konuları ele alınmıştır. Sulama suyu, sulama aralıkları arasında oluşan toplam A Sınıfı buharlaşma kabından okunan değerlere göre hesaplanmıştır. Çalışmada, konulara göre, sulama suyu (IW ve bitki su tüketimleri (ET, sırasıyla, 266.2–413.5 mm (12–16 sulama ve 433.1-520.6 mm arasında değişmiş; en yüksek IW ve mevsimlik ET ise, sırasıyla, 413.5 mm ve 520.6 mm ile CTJ konusundan 2006 yılında elde edilmiştir. Karpuz bitkisinde en yüksek ortalama aylık ET, 214.0 mm ile CTJ konusunda Mayıs ayında ölçülmüş; bu ayda ortalama çim kıyas bitki su tüketimi (ETo, 163.1 mm olarak belirlenmiştir. Bitki katsayısı (Kc değerlerinin; deneme yılları için, başlangıç, mevsim ortası ve mevsim sonudönemlerinde, sırasıyla, 0.240.67, 0.87-1.66 ve 0.83-0.93 olarak değiştiği saptanmıştır. Son yılki çalışmada; toplam kök yoğunluğunun aşılı konularda aşısızlara kıyasla % 4 daha fazla; yaprak su potansiyeli (YSP değerlerlerinin -0.20 ile -0.70 MPa arasında değiştiği ve aşılı konuların daha yüksek YSP değerlerine sahip olduğu saptanmıştır. Aşılama ile verim, toplam su kullanma randımanı (TWUE ve su kullanım randımanı (IWUE artarken sulama suyunun ET içerisindeki kullanım oranı (IWc aşısız konularında daha yüksek olduğu belirlenmiştir. En yüksek verim 712.8 kg/ha ile CTJ konusundan 2008 yılından elde edilmiştir

Ages of young star clusters, massive blue stragglers, and the upper mass limit of stars: Analyzing age-dependent stellar mass functions

Energy Technology Data Exchange (ETDEWEB)

Schneider, F. R. N.; Izzard, R. G.; Langer, N.; Stolte, A.; Hußmann, B. [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); De Mink, S. E. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); De Koter, A.; Sana, H. [Astronomical Institute " Anton Pannekoek" , Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands); Gvaramadze, V. V. [Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetskij Pr. 13, Moscow 119992 (Russian Federation); Liermann, A., E-mail: fschneid@astro.uni-bonn.de [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)

2014-01-10

Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M {sub ☉} limit and observations of four stars with initial masses of 165-320 M {sub ☉} in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M {sub ☉} star. Using the stellar population of R136, we revise the upper mass limit to values in the range

Ages of young star clusters, massive blue stragglers, and the upper mass limit of stars: Analyzing age-dependent stellar mass functions

International Nuclear Information System (INIS)

Schneider, F. R. N.; Izzard, R. G.; Langer, N.; Stolte, A.; Hußmann, B.; De Mink, S. E.; Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" data-affiliation=" (Astronomical Institute Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" >De Koter, A.; Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" data-affiliation=" (Astronomical Institute Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam (Netherlands))" >Sana, H.; Gvaramadze, V. V.; Liermann, A.

2014-01-01

Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M ☉ limit and observations of four stars with initial masses of 165-320 M ☉ in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M ☉ star. Using the stellar population of R136, we revise the upper mass limit to values in the range 200-500 M ☉ .

Ages of Young Star Clusters, Massive Blue Stragglers, and the Upper Mass Limit of Stars: Analyzing Age-dependent Stellar Mass Functions

Science.gov (United States)

Schneider, F. R. N.; Izzard, R. G.; de Mink, S. E.; Langer, N.; Stolte, A.; de Koter, A.; Gvaramadze, V. V.; Hußmann, B.; Liermann, A.; Sana, H.

2014-01-01

Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. The latter aspect is important for populations of massive stars as more than 70% of all O stars are expected to interact with a binary companion during their lifetime. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters that can be used to infer their ages and to identify products of binary evolution. We model the observed present-day mass functions of the young Galactic Arches and Quintuplet star clusters using our rapid binary evolution code. We find that the shaping of the mass function by stellar wind mass loss allows us to determine the cluster ages as 3.5 ± 0.7 Myr and 4.8 ± 1.1 Myr, respectively. Exploiting the effects of binary mass exchange on the cluster mass function, we find that the most massive stars in both clusters are rejuvenated products of binary mass transfer, i.e., the massive counterpart of classical blue straggler stars. This resolves the problem of an apparent age spread among the most luminous stars exceeding the expected duration of star formation in these clusters. We perform Monte Carlo simulations to probe stochastic sampling, which support the idea of the most massive stars being rejuvenated binary products. We find that the most massive star is expected to be a binary product after 1.0 ± 0.7 Myr in Arches and after 1.7 ± 1.0 Myr in Quintuplet. Today, the most massive 9 ± 3 stars in Arches and 8 ± 3 in Quintuplet are expected to be such objects. Our findings have strong implications for the stellar upper mass limit and solve the discrepancy between the claimed 150 M ⊙ limit and observations of four stars with initial masses of 165-320 M ⊙ in R136 and of supernova 2007bi, which is thought to be a pair-instability supernova from an initial 250 M ⊙ star. Using the stellar population of R136, we revise the upper mass limit to values in the range 200-500 M ⊙.

Approaches and Views of Teachers and Administrators Related to the Usage of Interactive WhiteBoards and Tablet PCs [Öğretmen ve Yöneticilerin Etkileşimli Tahta ve Tablet Bilgisayar Kullanımına Yönelik Yaklaşımları ve Görüşleri

Directory of Open Access Journals (Sweden)

Gökhan Dağhan

2015-12-01

Full Text Available The aim of the study is to determine approaches of administrators and teachers related to the use of interactive whiteboards and tablet PCs which are distributed in schools within FATİH project. Research was carried out with 32 administrator and 36 teachers who works at FATİH project implementation schools. Seperate forms consisting of different open-ended questions were posed to teachers and administrators. Data was analyzed with content analysis. Administrators indicate that the courses supported by this technology will provide effective learning; courses will be more efficient in a shorter time; motivation, interest and involvement will be affected in a positive direction. Teachers states that technology supported courses will increase the interest of students and develop various skills. According to the statements the most important problem related to the use of these technologies seems to be caused by lack of sufficient educational e-content. Organizing “practical” trainings which aims at gaining ability to create educational e-content for teachers could be solution to sufficient e-content problem. [Bu çalışmanın amacı FATİH projesiyle birlikte okullarda dağıtılan etkileşimli tahta ve tablet bilgisayarlarla ilgili olarak, yöneticilerin ve farklı alanlarda görev yapan öğretmenlerin görüşlerinin ve bu teknolojilerin kullanımlarına yönelik yaklaşımlarının belirlenmesidir. Araştırma FATİH projesinin uygulandığı okullarda görev yapan 32 yönetici ve 36 öğretmenle yürütülmüştür. Öğretmen ve yönetici formu olmak üzere farklı açık uçlu sorulardan oluşan anket katılımcılara yöneltilmiş, veriler içerik analizi ile çözümlenmiştir. Yöneticiler derslerin bu teknolojilerle desteklenerek işlenmesi ile etkili öğrenmelerin sağlanacağını; daha kısa zamanda daha verimli dersler işleneceğini; motivasyon ilgi ve katılımın olumlu yönde etkileneceğini belirtmektedirler. �

Mikrodenetleyici Kontrollü, Termoelektrik Kaynaklı Kablosuz ve Sensörsüz Yüksek Sıcaklık Duyum Devresi

Directory of Open Access Journals (Sweden)

Ahmet KÜÇÜKKÖMÜRLER

2014-07-01

Full Text Available Sürdürülebilir enerjinin her geçen gün daha da önemli bir konu olduğu günümüzde, enerji üretmenin farklı yöntemleri araştırılmakta ve denenmektedir. Bu yöntemlerden bir tanesi de atıl ısıdan elektrik enerjisi üretmektir. Termoelektrik malzeme, iki yüzeyi arasında sıcaklık farkı meydana gelmesi durumunda elektriksel bir gerilim üreten malzemelerdir. Bu çalışmada termoelektrik malzeme ile atıl ısı elektrik enerjisine çevrilerek, RF (Radyo Frekansı alıcı-verici kullanımı ile yüksek sıcaklık kablosuz ve sensörsüz duyum devresi tasarımı gerçekleştirilmiştir. Tasarımı gerçekleştirilen bu devrede TMG-450-0.8-1.0 termoelektrik üreteç, ATX-34 RF verici, ARX-34 radyo frekans alıcı ve 8051 mikrodenetleyicisi kullanılmıştır. Sistem, laboratuar ortamında test edilmiş ve otomotiv alanında kablosuz ve sensörsüz yüksek sıcaklık ölçüm uygulamaları için simülasyon ve deneysel sonuçlar elde edilerek bu sonuçların doğruluğu gösterilmiştir.

A Search for Coronal Emission at the Bottom of the Main-Sequence: Stars and Brown Dwarf Candidates with Spectral Types Later than M7 and the Rotation-Activity Relation

Science.gov (United States)

Stringfellow, Guy

2004-01-01

This program intended to test whether the lowest mass stars at the bottom end of the main sequence and the lower mass brown dwarfs have coronae. If they have coronae, what are the coronal characteristics and what drives them? In the classical dynamo picture, the closed magnetic loop structure is generated near the boundary of the convective envelope and the radiative core. Stars with mass below 0.30 Msun however are fully convective, and the nature of the dynamo responsible for the generation of the coronae in this regime is poorly understood. Previous results from the ROSAT mission (e.g., Fleming et al. 1993, 1995; Schmitt et al. 1995) had confirmed three very important characteristics of M-star coronae: (1) a very high percentage of all M dwarfs have coronae (of order 85% in the local 7 pc sample), (2) those M dwarfs showing high chromospheric activity, such as having the Balmer series in emission or large/numerous optical flaring, indeed exhibit the highest coronal activity, and (3) that the maximum saturation boundary in X-ray luminosity, which amounts to 0.0001-0.001 for Lx/Lbol for the dMe stars, extends down to the current detection limit, through spectral types M7. It was likely that the incompleteness noted for result (1) above was simply a detection limit problem; for more distant sources, the X-ray fainter dM stars will drop below detection thresholds before the more X-ray luminous dMe stars. The latest stars for which direct detection of the corona had been successful were of spectral type dM7 (e.g., VB8, LHS 3003). This program proposed to obtain ROSAT HRI observations for a large number of the coolest known (at that time) stars at the bottom of the main-sequence, which had spectral types of M9 or later. Three stars were approved for observations with ROSAT-HRI totaling 180 ksec. The goal was to obtain X-ray detections or low upper limits for the three approved stars.

The late-M dwarfs

International Nuclear Information System (INIS)

Bessell, M.S.

1991-01-01

Far-red spectra and VRIJHK photometry have been obtained for a sample of late-M dwarfs selected on the basis of large reduced red magnitudes from the LHS Catalog. Half of the stars in the three faintest 1 mag bins are late-M stars, the other red stars are metallic-hydride subdwarfs. Relations between various colors for the late-M dwarfs are investigated. Of all the colors I - K most reliably correlates with spectral type. FeH bands near 9900 A are clearly seen in the spectra of all dwarf stars later than M5. Two stars cooler than VB10, and similar in temperature to LHS2924 have been identified; both have H-alpha in emission and appear variable in magnitude and R - I color; one is a flare star. The other stars are of earlier spectral type and resemble W359 and VB8. The observed MI, I - K main sequence is in good agreement with the IG theoretical main sequence of Stringfellow, and the faintest stars could be about 0.09 solar mass red dwarfs or lower mass brown dwarfs. 65 refs

Probiyotik Mayalar ve Özellikleri

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Hatice Yıldıran

2017-10-01

Full Text Available Probiyotikler tüketicinin sağlığı üzerinde olumlu etkileri olan mikroorganizmalardır. Probiyotik uygulamalarının sağlık üzerine etkileri hakkında yapılmış pekçok araştırma bulunmaktadır. En yaygın kullanılan probiyotik bakteriler; bifidobakteriler ve laktobasiller, laktokoklar ve streptokoklar gibi laktik asit bakterileridir. İnsanlar için probiyotik olarak kullanılan mikroorganizmalar arasında ayrıca mayalar, basiller ve enterokoklar da bulunmaktadır. Probiyotik mayalar son yıllarda bilim insanları için ilgi çekici bir alan olmuştur. Yapılan bazı çalışmalar Saccharomyces cinsine ait türlerin antibakteriyel ve probiyotik özelliklere sahip olabileceklerini göstermiştir. Saccharomyces boulardii yıllardır insanları farklı gastrointestinal rahatsızlıklarından korumak veya hastalıklardan iyileştirmek amacıyla probiyotik olarak kullanılan, patojenik olmayan bir mayadır. S. boulardii özellikle ilaç endüstrisinde genellikle liyofilize formda kullanılmaktadır. Yapılan bu derleme çalışmasında probiyotikler, mayaların probiyotik olma özellikleri ve probiyotik mayaların kullanım alanları hakkında bilgiler verilmiş ve bu alanda yapılan araştırmalardan örnekler sunulmuştur.

Stellar Populations of over 1000 z ∼ 0.8 Galaxies from LEGA-C: Ages and Star Formation Histories from D n 4000 and Hδ

Science.gov (United States)

Wu, Po-Feng; van der Wel, Arjen; Gallazzi, Anna; Bezanson, Rachel; Pacifici, Camilla; Straatman, Caroline; Franx, Marijn; Barišić, Ivana; Bell, Eric F.; Brammer, Gabriel B.; Calhau, Joao; Chauke, Priscilla; van Houdt, Josha; Maseda, Michael V.; Muzzin, Adam; Rix, Hans-Walter; Sobral, David; Spilker, Justin; van de Sande, Jesse; van Dokkum, Pieter; Wild, Vivienne

2018-03-01

Drawing from the LEGA-C data set, we present the spectroscopic view of the stellar population across a large volume- and mass-selected sample of galaxies at large look-back time. We measure the 4000 Å break (D n 4000) and Balmer absorption line strengths (probed by Hδ) from 1019 high-quality spectra of z = 0.6–1.0 galaxies with M * = 2 × 1010 M ⊙ to 3 × 1011 M ⊙. Our analysis serves as a first illustration of the power of high-resolution, high signal-to-noise ratio continuum spectroscopy at intermediate redshifts as a qualitatively new tool to constrain galaxy formation models. The observed D n 4000–EW(Hδ) distribution of our sample overlaps with the distribution traced by present-day galaxies, but z ∼ 0.8 galaxies populate that locus in a fundamentally different manner. While old galaxies dominate the present-day population at all stellar masses >2 × 1010 M ⊙, we see a bimodal D n 4000–EW(Hδ) distribution at z ∼ 0.8, implying a bimodal light-weighted age distribution. The light-weighted age depends strongly on stellar mass, with the most massive galaxies >1 × 1011 M ⊙ being almost all older than 2 Gyr. At the same time, we estimate that galaxies in this high-mass range are only ∼3 Gyr younger than their z ∼ 0.1 counterparts, at odds with purely passive evolution given a difference in look-back time of >5 Gyr; younger galaxies must grow to >1011 M ⊙ in the meantime, or small amounts of young stars must keep the light-weighted ages young. Star-forming galaxies at z ∼ 0.8 have stronger Hδ absorption than present-day galaxies with the same D n 4000, implying larger short-term variations in star formation activity.

NEW X-RAY DETECTIONS OF WNL STARS

International Nuclear Information System (INIS)

Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel; Schmutz, Werner; Sokal, Kimberly R.

2012-01-01

Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (L x ) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v ∞ ). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing L x with wind luminosity L wind = (1/2)M-dot v 2 ∞ , suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

NEW X-RAY DETECTIONS OF WNL STARS

Energy Technology Data Exchange (ETDEWEB)

Skinner, Stephen L. [Center for Astrophysics and Space Astronomy (CASA), University of Colorado, Boulder, CO 80309-0389 (United States); Zhekov, Svetozar A. [Space and Solar-Terrestrial Research Institute, Moskovska str. 6, Sofia-1000 (Bulgaria); Guedel, Manuel [Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Schmutz, Werner [Physikalisch-Meteorologisches Observatorium Davos (PMOD), Dorfstrasse 33, CH-7260 Davos Dorf (Switzerland); Sokal, Kimberly R., E-mail: Stephen.Skinner@colorado.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2012-05-15

Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (L{sub x} ) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v{sub {infinity}}). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing L{sub x} with wind luminosity L{sub wind} = (1/2)M-dot v{sup 2}{sub {infinity}}, suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

VBLUM photometry of RR Lyrae stars in ω Cen and M4

International Nuclear Information System (INIS)

DeBruijn, J.W.; Lub, J.

1987-01-01

Multicolour VBLUW photometry of RR Lyrae stars in the globular clusters M4 and ω Cen is used to derive information on reddening, blanketing, effective temperatures and gravity of these stars. The methods employed in the literature to determine the reddening of globular clusters from the UBV colours of the RR Lyrae stars are in complete agreement with the results from VBLUW photometry. The most important conclusions of the present work are: the close similarity between the RR Lyrae variables in the field and in globular clusters, and the agreement between the reddenings derived for RR Lyrae in the field and in globular clusters. This means that at least one parameter which normally is taken as a free parameter in studying globular cluster colour magnitude diagrams can be constrained very precisely

PERİFERİK KAN KÜLTÜRÜ VE YÖNETİMİ

OpenAIRE

ARDAHAN SEVGİLİ, SEDA; YARDIMCI, FİGEN

2018-01-01

Başlık: PERİFERİK KAN KÜLTÜRÜ VE YÖNETİMİTitle: PERIPHERALBLOOD CULTURE AND MANAGEMENTÖzet: Kandolaşımı enfeksiyonları; enfeksiyona neden olan mikroorganizma ile etkilediğicanlı arasında birçok etkileşim sonucunda meydana gelen ve oldukça karmaşık birsüreçtir. Bundan dolayı kan dolaşımı enfeksiyonlarının erken dönemdetanılanması ve tanısına yönelik tedavisinin başlatılması yaşamsal önemtaşımaktadır. Kan kültürleri; ciddi kan dolaşımı enfeksiyonlarının tanımlanmasıve...

Single-molecule imaging reveals topological isomer-dependent diffusion by 4-armed star and dicyclic 8-shaped polymers

KAUST Repository

Habuchi, Satoshi

2015-04-21

Diffusion dynamics of topological isomers of polymer molecules was investigated at the single-molecule level in a melt state by employing the fluorophore-incorporated 4-armed star and the corresponding doubly-cyclized, 8-shaped poly(THF) chains. While the single-molecule fluorescence imaging experiment revealed that the diffusion of the 4-armed star polymer was described by a single Gaussian distribution, the diffusion of the 8-shaped polymer exhibited a double Gaussian distribution behaviour. We reasoned that the two 8-shaped polymeric isomers have distinct diffusion modes in the melt state, although ensemble-averaged experimental methods cannot detect differences in overall conformational state of the isomers. The single-molecule experiments suggested that one of the 8-shaped polymeric isomer, having the horizontally oriented form, causes an efficient threading with the linear matrix chains which leads to the slower diffusion compared with the corresponding 4-armed star polymer, while the other 8-shaped polymeric isomer, having the vertically oriented form, displayed faster diffusion by the suppression of effective threading with the linear matrix chains due to its contracted chain conformation.

HÜMİK ASİT VE HÜMİK ASİT KAYNAKLARININ ÖNEMİ

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Faruk AY

2014-10-01

Full Text Available İnsanoğlu tarımsal alanda verimi arttırmak ve kaliteli ürün elde etmek için çok eski çağlardan günümüze değin bir çaba içerisindedir. Bu amaca yönelik olarak kimyasal gübre kullanımı uzun zamandan beri başvurulan yöntemlerden biridir. Kimyasal gübreleme ile bitkiler bazı inorganik besin maddelerini bu yolla temin edebilmekte fakat toprağa karıştırılan kimyasal gübreler bitki tarafından yeterince kullanılamamakta, bitki tarafından kullanılmayan kısım yağmur, kar ve sulama suyu vasıtasıyla topraktan uzaklaşıp yer altı kaynak sularına, denizlere, göllere karışarak önemli ekolojik sorunlara neden olmaktadır. Bu nedenle tarımda organik madde kullanımı giderek önem kazanmaktadır. En önemli toprak organik maddelerinden olan hümik asit ve fulvik asidin bitki gelişimi üzerindeki yararlı etkileri yapılan pek çok araştırmayla belirlenmiştir. Bu hümik maddelerin toprağın fiziksel, kimyasal ve mikrobiyolojik özelliklerini, dolayısıyla da bitki gelişimini etkilediği bilinmektedir.Ülkemizin birçok bölgesinde linyit ve turba rezervleri bulunmaktadır. Türkiye’de yaklaşık 8,4 milyar ton linyit rezervi saptanmıştır. Bu tür kömürler genellikle ısınma ve Hidroelektrik Santrallerinde kullanılmaktadır. Ancak bu yöntemlerde kullanılan linyitlerden fazla miktarda verim sağlanamamaktadır. Topraklarımızın kimyasal gübreler sonucu oluşan deformasyonunu ve verimini artırmak için, ülkemizin birçok alanında bulunan özellikle düşük kalorili linyit yataklarının ekonomik açıdan değerlendirilmesi ve ülkemizin topraklarının zenginleştirilmesi için gerekli olan organik gübre (Hümik Asit üretiminde kullanılması daha yararlı olacağı görüşü gittikçe dikkat çekici olmaktadır.Anahtar Kelimeler: Linyit, hümik asit, fülvik asit, organik gübre.

Laktoperoksidaz Sistemin Aktivasyonuyla ve Soğutularak Korunan Sütlerin Mikrobiyolojik Özellikleri

Directory of Open Access Journals (Sweden)

Zerrin Erginkaya

2015-02-01

Full Text Available Araştırmada, 12:8 mg/l ve 24:16 mg/l Tiyosiyanat: Hidrojenperoksit (SCN:H2O2 ilavesi ile laktoperoksidaz sistemi aktive edilen sütler 30°C'de 6 saat süreyle bekletilmişlerdir. Soğutularak 4±1°C'de tutulan, ayrıca kontrol olarak da SCN:H2O2 katılmamış ve 30°C'de tutulan süt örnekleri de aynı süre bekletilmişlerdir. Bekletmenin 0., 3. ve 6. saatlerinde sütün pH değeri, asittik derecesi ve bazı mikroorganizma grubu içeriklerindeki değişimler incelenmiştir. Laktoperoksidaz sisteminin aktivasyonunun, sütlerin toplam aerob mezofil ve psikrotrof bakteri gruplarının, mezofil ve termofil laktik asit bakteri gruplarının, enterobakterlerin ve küf-mayaların gelişimini önemli düzeyde etkilediği görülmüştür (p<0,05. Soğutmanın da toplam aerob psikrotrof bakteriler dışında, incelenen diğer tüm mikroorganizma gruplarını önemli düzeyde etkilediği bulunmuştur. SCN:H2O2 konsantrasyonunun artmasının, sistemin antimikrobiyel etkisini artırdığı belirlenmiştir. Laktoperoksidaz sisteminin aktivasyonunun soğutma kadar etkin olduğu, toplam aerob mezofil ve psikrotrof bakterilerle, enterobakterler üzerinde soğutmadan daha fazla etkili olduğu görülmüştür. Soğutma işlemi ve laktoperoksidaz sisteminin aktivasyonu, sütlerin pH ve asitlik değerleri üzerinde önemli ve yaklaşık aynı düzeyde etkili bulunmuştur (p<0,05.

Dwarf spheroidal satellites of M31. I. Variable stars and stellar populations in Andromeda XIX

Energy Technology Data Exchange (ETDEWEB)

Cusano, Felice; Clementini, Gisella; Garofalo, Alessia; Federici, Luciana, E-mail: felice.cusano@oabo.inaf.it, E-mail: gisella.clementini@oabo.inaf.it, E-mail: luciana.federici@oabo.inaf.it, E-mail: alessia.garofalo@studio.unibo.it [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); and others

2013-12-10

We present B, V time-series photometry of Andromeda XIX (And XIX), the most extended (half-light radius of 6.'2) of Andromeda's dwarf spheroidal companions, which we observed with the Large Binocular Cameras at the Large Binocular Telescope. We surveyed a 23' × 23' area centered on And XIX and present the deepest color-magnitude diagram (CMD) ever obtained for this galaxy, reaching, at V ∼ 26.3 mag, about one magnitude below the horizontal branch (HB). The CMD shows a prominent and slightly widened red giant branch, along with a predominantly red HB, which extends to the blue to significantly populate the classical instability strip. We have identified 39 pulsating variable stars, of which 31 are of RR Lyrae type and 8 are Anomalous Cepheids (ACs). Twelve of the RR Lyrae variables and three of the ACs are located within And XIX's half light radius. The average period of the fundamental mode RR Lyrae stars ((P {sub ab}) = 0.62 days, σ = 0.03 days) and the period-amplitude diagram qualify And XIX as an Oosterhoff-Intermediate system. From the average luminosity of the RR Lyrae stars ((V(RR)) = 25.34 mag, σ = 0.10 mag), we determine a distance modulus of (m – M){sub 0} = 24.52 ± 0.23 mag in a scale where the distance to the Large Magellanic Cloud (LMC) is 18.5 ± 0.1 mag. The ACs follow a well-defined Period-Wesenheit (PW) relation that appears to be in very good agreement with the PW relationship defined by the ACs in the LMC.

DİN KÜLTÜRÜ VE AHLAK BİLGİSİ ÖĞRETMENLERİNİN EĞİTİM ÖĞRETİM YETERLİK ALGILARI

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Mahmut ZENGİN

2013-06-01

Full Text Available Bu araştırmada Sakarya ilinde ilköğretim ve orta öğretim okullarında görev yapmakta olan Din Kültürü ve Ahlak Bilgisi öğretmenlerinin eğitim öğretim yeterlik algılarını belirlemek amaçlanmıştır.Araştırmanın evrenini Sakarya'nın il ve ilçelerindeki 329 Din Kültürü ve Ahlak Bilgisi öğretmeni, örneklemini ise merkez ilçeler dahil 11 ilçedeki 165 DKAB öğretmeni oluşturmaktadır.Araştırma verilerini toplamak için kişisel bilgi anketi ile “Din Kültürü ve Ahlak Bilgisi Öğretmenlerinin Eğitim Öğretim Yeterlikleri Ölçeği” kullanılmıştır. Ölçek, mesleki gelişim, öğrenciyi tanıma, öğrenme ve öğretmen süreci ile ölçme ve değerlendirme olmak üzere 4 boyuttan oluşmaktadır.Dört boyutun açıkladığı toplam varyans % 55,09 olup, ölçeğin KMO değeri ,92, Cronbach's Alpha katsayısı ise ,964'tür. Veriler, Mayıs 2012'de okullara gidilerek ve İlçe Milli Eğitim Müdürlükleri kanalıyla toplanmıştır. Elde edilen veriler SPSS 16.00 programına aktarılmıştır.Araştırma problemlerinin test edilmesinde t-testi ve varyans analizi kullanılmıştır. Çoklu karşılaştırmalarda ise Tukey testinden faydalanılmıştır. Hipotezlerin test edilmesinde 0,05 anlamlılık düzeyi esas alınmıştır. Araştırma bulgularından bazıları şöyledir: öğretmenlerin eğitim öğretim yeterlik algıları cinsiyete göre farklılaşmaktadır. Mezun olunan lisans programı ile yeterlik algıları arasında sadece mesleki gelişim boyutunda anlamlı bir ilişki bulunmakla birlikte DKAB öğretmenliği bölümü mezunu öğretmenlerin yeterlik ortalamalarının daha yüksek olduğu tespit edilmiştir.Öğretmenlerin öğrenim durumları, görev yapılan öğretim kademesi, görev yapılan yerleşim yeri, hizmet içi eğitime katılma durumu ve hizmet içi eğitime katılma sayısı değişkenleri ile yeterlikleri arasında anlamlı bir ilişki bulunamamıştır. Öğretmenlerin DKAB

Cooling of hypernuclear compact stars

Science.gov (United States)

Raduta, Adriana R.; Sedrakian, Armen; Weber, Fridolin

2018-04-01

We study the thermal evolution of hypernuclear compact stars constructed from covariant density functional theory of hypernuclear matter and parametrizations which produce sequences of stars containing two-solar-mass objects. For the input in the simulations, we solve the Bardeen-Cooper-Schrieffer gap equations in the hyperonic sector and obtain the gaps in the spectra of Λ, Ξ0, and Ξ- hyperons. For the models with masses M/M⊙ ≥ 1.5 the neutrino cooling is dominated by hyperonic direct Urca processes in general. In the low-mass stars the (Λp) plus leptons channel is the dominant direct Urca process, whereas for more massive stars the purely hyperonic channels (Σ-Λ) and (Ξ-Λ) are dominant. Hyperonic pairing strongly suppresses the processes on Ξ-s and to a lesser degree on Λs. We find that intermediate-mass 1.5 ≤ M/M⊙ ≤ 1.8 models have surface temperatures which lie within the range inferred from thermally emitting neutron stars, if the hyperonic pairing is taken into account. Most massive models with M/M⊙ ≃ 2 may cool very fast via the direct Urca process through the (Λp) channel because they develop inner cores where the S-wave pairing of Λs and proton is absent.

MAGNETIC FIELD TOPOLOGY IN LOW-MASS STARS: SPECTROPOLARIMETRIC OBSERVATIONS OF M DWARFS

International Nuclear Information System (INIS)

Phan-Bao, Ngoc; Lim, Jeremy; Donati, Jean-Francois; Johns-Krull, Christopher M.; MartIn, Eduardo L.

2009-01-01

The magnetic field topology plays an important role in the understanding of stellar magnetic activity. While it is widely accepted that the dynamo action present in low-mass partially convective stars (e.g., the Sun) results in predominantly toroidal magnetic flux, the field topology in fully convective stars (masses below ∼0.35 M sun ) is still under debate. We report here our mapping of the magnetic field topology of the M4 dwarf G 164-31 (or Gl 490B), which is expected to be fully convective, based on time series data collected from 20 hr of observations spread over three successive nights with the ESPaDOnS spectropolarimeter. Our tomographic imaging technique applied to time series of rotationally modulated circularly polarized profiles reveals an axisymmetric large-scale poloidal magnetic field on the M4 dwarf. We then apply a synthetic spectrum fitting technique for measuring the average magnetic flux on the star. The flux measured in G 164-31 is |Bf| = 3.2 ± 0.4 kG, which is significantly greater than the average value of 0.68 kG determined from the imaging technique. The difference indicates that a significant fraction of the stellar magnetic energy is stored in small-scale structures at the surface of G 164-31. Our Hα emission light curve shows evidence for rotational modulation suggesting the presence of localized structure in the chromosphere of this M dwarf. The radius of the M4 dwarf derived from the rotational period and the projected equatorial velocity is at least 30% larger than that predicted from theoretical models. We argue that this discrepancy is likely primarily due to the young nature of G 164-31 rather than primarily due to magnetic field effects, indicating that age is an important factor which should be considered in the interpretation of this observational result. We also report here our polarimetric observations of five other M dwarfs with spectral types from M0 to M4.5, three of them showing strong Zeeman signatures.

K-band spectroscopic metallicities and temperatures of M-dwarf stars

Directory of Open Access Journals (Sweden)

Rojas-Ayala Bárbara

2013-04-01

Full Text Available I present the metallicity and effective temperature techniques developed for M dwarf stars by Rojas-Ayala et al. (2010, 2012. These techniques are based on absorption features present in the modest resolution K-band spectra (R∼2700 of M dwarfs and have been calibrated using FGK+M dwarf pairs and synthetic atmosphere models. The H2O-K2 index seems to overestimate the effective temperatures of M dwarfs when compared to interferometric measurements. The metallicity distribution of the M dwarf host candidates by the Kepler Mission hints that jovian-size planets form preferentially around solar and super-solar metallicity environments, while small rocky planet host exhibit a wide range of metallicities, just like in their solar-type counterparts.

A phase 3, double-blind, randomized placebo-controlled efficacy and safety study of abiraterone acetate in chemotherapy-naïve patients with mCRPC in China, Malaysia, Thailand and Russia.

Science.gov (United States)

Ye, Dingwei; Huang, Yiran; Zhou, Fangjian; Xie, Keji; Matveev, Vsevolod; Li, Changling; Alexeev, Boris; Tian, Ye; Qiu, Mingxing; Li, Hanzhong; Zhou, Tie; De Porre, Peter; Yu, Margaret; Naini, Vahid; Liang, Hongchuan; Wu, Zhuli; Sun, Yinghao

2017-04-01

This double-blind, placebo-controlled phase 3 study was designed to compare efficacy and safety of abiraterone acetate + prednisone (abiraterone) to prednisone alone in chemotherapy-naïve, asymptomatic or mildly symptomatic metastatic castration-resistant prostate cancer (mCRPC) patients from China, Malaysia, Thailand and Russia. Adult chemotherapy-naïve patients with confirmed prostate adenocarcinoma, Eastern Cooperative Oncology Group (ECOG) performance status (PS) grade 0-1, ongoing androgen deprivation (serum testosterone <50 ng/dL) with prostate specific antigen (PSA) or radiographic progression were randomized to receive abiraterone acetate (1000 mg, QD) + prednisone (5 mg, BID) or placebo + prednisone (5 mg, BID), until disease progression, unacceptable toxicity or consent withdrawal. Primary endpoint was improvements in time to PSA progression (TTPP). Totally, 313 patients were randomized (abiraterone: n  = 157; prednisone: n  = 156); and baseline characteristics were balanced. At clinical cut-off (median follow-up time: 3.9 months), 80% patients received treatment (abiraterone: n  = 138, prednisone: n  = 112). Median time to PSA progression was not reached with abiraterone versus 3.8 months for prednisone, attaining 58% reduction in PSA progression risk (HR = 0.418; p  < 0.0001). Abiraterone-treated patients had higher confirmed PSA response rate (50% vs. 21%; relative odds = 2.4; p  < 0.0001) and were 5 times more likely to achieve radiographic response than prednisone-treated patients (22.9% vs.  4.8%, p  = 0.0369). Median survival was not reached. Most common (≥10% abiraterone vs.  prednisone-treated) adverse events: bone pain (7% vs. 14%), pain in extremity (6% vs. 12%), arthralgia (10% vs. 8%), back pain (7% vs. 11%), and hypertension (15% vs. 14%). Interim analysis confirmed favorable benefit-to-risk ratio of abiraterone in chemotherapy-naïve men with mCRPC, consistent with global study, thus supporting use of

A model to investigate the optimal seeder-to-naïve ratio for successful natural Mycoplasma hyopneumoniae gilt exposure prior to entering the breeding herd.

Science.gov (United States)

Roos, Luiza R; Fano, Eduardo; Homwong, Nitipong; Payne, Brian; Pieters, Maria

2016-02-29

Due to the significance of Mycoplasma hyopneumoniae as a swine respiratory pathogen, acclimation measures are taken into consideration when obtaining replacement gilts from negative sources to be introduced to endemically infected herds. The aim of this study was to evaluate the optimum seeder-to-naïve gilt ratio in a 4-week period for successful natural exposure to M. hyopneumoniae. Sixty gilts were divided in two groups, 21 2-week old seeder gilts were inoculated with M. hyopneumoniae, and 39 aged-matched naïve gilts were exposed to the seeders during a 4-week period. The exposure was set by dividing the gilts into six groups of 10 with different ratios of seeder-to-naïve, from 1:9 until 6 seeders and 4 naïve gilts. Laryngeal swabs, oral fluids and blood samples were collected from all gilts prior to, during and after inoculation and exposure. Infection in seeders was confirmed by development of clinical signs, seroconversion post-inoculation, and detection of M. hyopneumoniae genetic material. Naïve were considered positive after 4 weeks if M. hyopneumoniae was detected on bronchial swab or fixed lung tissue. As result, 33% (3/9) naïve gilts were positive in the 1:9 ratio, 75% (6/8) in 2:8, 28% (2/7) in 3:7, 33% (2/6) in 4:6, 80% (4/5) in 5:5 and 100% (4/4) in the 6:4 ratio. The estimated transmission rate (β) and expected probability of infection (ψ) were 1.28 per pig/week and 0.6, respectively. In this study, six seeders were required in a group of 10 gilts for successful exposure to M. hyopneumoniae in a 4-week exposure period. Copyright © 2016 Elsevier B.V. All rights reserved.

AN INCREASE IN THE MASS OF PLANETARY SYSTEMS AROUND LOWER-MASS STARS

International Nuclear Information System (INIS)

Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

2015-01-01

Trends in the planet population with host star mass provide an avenue to constrain planet formation theories. We derive the planet radius distribution function for Kepler stars of different spectral types, sampling a range in host star masses. We find that M dwarf stars have 3.5 times more small planets (1.0–2.8 R ⨁ ) than main-sequence FGK stars, but two times fewer Neptune-sized and larger (>2.8 R ⨁ ) planets. We find no systematic trend in the planet size distribution between spectral types F, G, and K to explain the increasing occurrence rates. Taking into account the mass–radius relationship and heavy-element mass of observed exoplanets, and assuming those are independent of spectral type, we derive the inventory of the heavy-element mass locked up in exoplanets at short orbits. The overall higher planet occurrence rates around M stars are not consistent with the redistribution of the same mass into more, smaller planets. At the orbital periods and planet radii where Kepler observations are complete for all spectral types, the average heavy-element mass locked up in exoplanets increases roughly inversely with stellar mass from 4 M ⨁ in F stars to 5 M ⨁ in G and K stars to 7 M ⨁ in M stars. This trend stands in stark contrast with observed protoplanetary disk masses that decrease toward lower mass stars, and provides a challenge for current planet formation models. Neither models of in situ formation nor migration of fully formed planets are consistent with these results. Instead, these results are indicative of large-scale inward migration of planetary building blocks—either through type-I migration or radial drift of dust grains—that is more efficient for lower mass stars, but does not result in significantly larger or smaller planets

AN INCREASE IN THE MASS OF PLANETARY SYSTEMS AROUND LOWER-MASS STARS

Energy Technology Data Exchange (ETDEWEB)

Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel, E-mail: mulders@lpl.arizona.edu [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States)

2015-12-01

Trends in the planet population with host star mass provide an avenue to constrain planet formation theories. We derive the planet radius distribution function for Kepler stars of different spectral types, sampling a range in host star masses. We find that M dwarf stars have 3.5 times more small planets (1.0–2.8 R{sub ⨁}) than main-sequence FGK stars, but two times fewer Neptune-sized and larger (>2.8 R{sub ⨁}) planets. We find no systematic trend in the planet size distribution between spectral types F, G, and K to explain the increasing occurrence rates. Taking into account the mass–radius relationship and heavy-element mass of observed exoplanets, and assuming those are independent of spectral type, we derive the inventory of the heavy-element mass locked up in exoplanets at short orbits. The overall higher planet occurrence rates around M stars are not consistent with the redistribution of the same mass into more, smaller planets. At the orbital periods and planet radii where Kepler observations are complete for all spectral types, the average heavy-element mass locked up in exoplanets increases roughly inversely with stellar mass from 4 M{sub ⨁} in F stars to 5 M{sub ⨁} in G and K stars to 7 M{sub ⨁} in M stars. This trend stands in stark contrast with observed protoplanetary disk masses that decrease toward lower mass stars, and provides a challenge for current planet formation models. Neither models of in situ formation nor migration of fully formed planets are consistent with these results. Instead, these results are indicative of large-scale inward migration of planetary building blocks—either through type-I migration or radial drift of dust grains—that is more efficient for lower mass stars, but does not result in significantly larger or smaller planets.

Small scale kinematics of massive star-forming cores

NARCIS (Netherlands)

Wang, Kuo-Song

2013-01-01

Unlike the formation of Solar-type stars, the formation of massive stars (M>8 Msun) is not yet well understood. For Solar-type protostars, the presence of circumstellar or protoplanetary disks which provide a path for mass accretion onto protostars is well established. However, to date only few

Star Formation Rates and Stellar Masses of z = 7-8 Galaxies from IRAC Observations of the WFC3/IR Early Release Science and the HUDF Fields

Science.gov (United States)

Labbé, I.; González, V.; Bouwens, R. J.; Illingworth, G. D.; Franx, M.; Trenti, M.; Oesch, P. A.; van Dokkum, P. G.; Stiavelli, M.; Carollo, C. M.; Kriek, M.; Magee, D.

2010-06-01

We investigate the Spitzer/IRAC properties of 36 z ~ 7 z 850-dropout galaxies and three z ~ 8 Y 098 galaxies derived from deep/wide-area WFC3/IR data of the Early Release Science, the ultradeep HUDF09, and wide-area NICMOS data. We fit stellar population synthesis models to the spectral energy distributions to derive mean redshifts, stellar masses, and ages. The z ~ 7 galaxies are best characterized by substantial ages (>100 Myr) and M/LV ≈ 0.2. The main trend with decreasing luminosity is that of bluing of the far-UV slope from β ~ -2.0 to β ~ -3.0. This can be explained by decreasing metallicity, except for the lowest luminosity galaxies (0.1L* z = 3), where low metallicity and smooth star formation histories (SFHs) fail to match the blue far-UV and moderately red H - [3.6] color. Such colors may require episodic SFHs with short periods of activity and quiescence ("on-off" cycles) and/or a contribution from emission lines. The stellar mass of our sample of z ~ 7 star-forming galaxies correlates with star formation rate (SFR) according to log M* = 8.70(±0.09) + 1.06(±0.10)log SFR, implying that star formation may have commenced at z > 10. No galaxies are found with SFRs much higher or lower than the past averaged SFR suggesting that the typical star formation timescales are probably a substantial fraction of the Hubble time. We report the first IRAC detection of Y 098-dropout galaxies at z ~ 8. The average rest-frame U - V ≈ 0.3 (AB) of the three galaxies are similar to faint z ~ 7 galaxies, implying similar M/L. The stellar mass density to M UV,AB Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11563, 9797. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA through contract 125790 issued by JPL/Caltech. Based on service

ROSAT X-ray luminosity functions of the Hyades dK and dM stars

Science.gov (United States)

Pye, John P.; Hodgkin, Simon T.; Stern, Robert A.; Stauffer, John R.

1994-02-01

Long-duration ROSAT PSPC pointed observations of the Hyades open star cluster are performed. The Hyades dK and XLFs from the present observations are compared with published Einstein dK/dM XLFs. The Hyades dK binaries have significantly higher L(X) than the Hyades dK stars. However, all these binaries have relatively long periods (greater than about 1 yr), and hence the L(X) levels cannot be attributed to the enhanced activity expected in short-period, 'BY Dra-type' systems. It is also shown that the effect cannot be due simply to the summed luminosities of the component stars.

Université de Genève | Particle Physics Colloquium | 30 April

CERN Multimedia

2014-01-01

Astronomical imaging a thousand times sharper than Hubble: optical interferometry with the Cherenkov Telescope Array, Prof. Dainis Dravins, Lund Observatory.   Wednesday 30 April 2014, 11:15 a.m. Science III, Auditoire 1S081 Boulevard d’Yvoy, 1211 Genève 4 Abstract: Much of the progress in astronomy is led by improved imaging. In the optical, one tantalizing threshold will be two-dimensional imaging of stellar surfaces. With typical sizes of a few milliarcseconds, bright stars require interferometry over kilometer-long baselines. Although several concepts for such interferometer complexes on the ground and in space have been proposed, their realization is not imminent. However, the availability of large optical flux collectors (air Cherenkov telescopes, in particular CTA – the Cherenkov Telescope Array – primarily erected for gamma-ray studies) enable a revival of the quantum-optical method of intensity interferometry, once developed for astronomy but re...

Değişik oranlarda kalsiyum karbonat kapsayan topraklarda çinkolu gübrelemenin mısır gelişimi ve antioksidatif enzim aktivitesine etkisi

OpenAIRE

Merken, Özen; Aydın, Mehmet

2008-01-01

Bu çalısmada farklı kireç seviyelerdeki çinko dozlarının mısır bitkisinde besin elementi içerikleri, bazı gelisme parametreleri ve antioksidatif enzim aktiviteleri üzerine etkileri arastırılmıstır. Kireç uygulaması ile bitki boyu, yaprak sayısı, kuru madde verimi, yaprak süperoksit dismutaz aktivitesi, klorofil ve protein çinko, kalsiyum ve magnezyum içerikleri artmıs, buna karsın fosfor, potasyum, demir, çinko ve bakır içerikleri düsmüstür. Çinko uygulaması ile ise bitki boyu, ya...

Hamburgerlerin bazı Fiziksel, Kimyasal ve Mikrobiyolojik Özelliklerine Donmuş Depolama Sıcaklığı ve Depolama Süresinin Etkisi Üzerinde Araştırma

Directory of Open Access Journals (Sweden)

A. Hamdi Ertaş

2015-02-01

Full Text Available Ticari amaçla üretilen hamburgerler, -8 oC ve –26 oC’de 85 gün süre ile depolanmışlar ve depolama sıcaklığının ve süresinin hamburgerlerin bazı fiziksel, kimyasal ve mikrobiyolojik özellikleri üzerine olan etkileri araştırılmıştır. Fiziksel kriterler olarak su tutma kapasitesi (STK, pişirme kaybı (PK ve büzülme derecesi (BD; kimyasal kriterler olarak rutubet, protein, yağ miktarları ile pH değeri ve tiyobarbütirik asit (TBA sayısı; mikrobiyolojik kriterler olarak ise toplam mezofil aerob bakteri (TMAB sayısı, psikrofil bakteri (PB sayısı ve koliform grubu bakteri (KGB sayısı dikkate alınmıştır. Depolama sıcaklığı ve depolama süresinin rutubet, protein, yağ miktarları, STK, PK ve BD üzerine etkisinin olmadığı, pH değeri üzerine p<0.01 düzeyinde etkisinin olduğu, TBA-sayısı üzerine depolama sıcaklığının p<0.01 düzeyinde depolama süresinin p<0.05 düzeyinde etkisi olduğu belirlenmiştir. –8 oC de depolama, hamburgerlerin pH değerlerini ve TBA-sayılarını önemli düzeyde artırırken, -26 oC de depolamada artış daha az düzeyde olmuştur. TMAB, PB ve KGB sayılarına, depolama sıcaklığının ve depolama süresinin etkisi görülmüş (p<0.01; -8 oC’de, depolama süresine bağlı olarak TMAB, PB ve KGB sayılarında sürekli bir artış görülürken –26 oC’de depolamada azalma olmuştur.

İç Anadolu Bölgesinde Yağ Bitkilerinin Mevcut Durumu, Sorunları ve Çözüm Önerileri

Directory of Open Access Journals (Sweden)

Sevgi Çalışkan

2013-12-01

Full Text Available Ülkemizde son yirmi yılda yağ bitkileri ekim alanlarında önemli bir artış olmamasına rağmen, üretim miktarında %52.2 oranında artış gerçekleşmiştir. Ülkemizde ekimi yapılan yağlı tohumlu bitkiler arasında gerek ekim alanı ve gerekse de üretim bakımından ilk sırayı alan ayçiçeği, İç Anadolu Bölgesinin de temel yağ bitkisi olarak ön plana çıkmış ve bunu aspir bitkisi takip etmiştir. Nadas alanları bakımından Türkiye toplamının %59’unu oluşturan İç Anadolu Bölgesinde, nadas alanlarında aspir tarımının yaygınlaştırılması hem bölge çiftçisine hem de ülke ekonomisine büyük kazanç sağlayacaktır.

New Galactic Candidate Luminous Blue Variables and Wolf-Rayet Stars

Science.gov (United States)

Stringfellow, Guy S.; Gvaramadze, Vasilii V.; Beletsky, Yuri; Kniazev, Alexei Y.

2012-04-01

We have undertaken a near-infrared spectral survey of stars associated with compact mid-IR shells recently revealed by the MIPSGAL (24 μm) and GLIMPSE (8 μm) Spitzer surveys, whose morphologies are typical of circumstellar shells produced by massive evolved stars. Through spectral similarity with known Luminous Blue Variable (LBV) and Wolf-Rayet (WR) stars, a large population of candidate LBVs (cLBVs) and a smaller number of new WR stars are being discovered. This significantly increases the Galactic cLBV population and confirms that nebulae are inherent to most (if not all) objects of this class.

Spitzer Observations of M33 & M83 and the Hot Star, Hii Region Connection

Science.gov (United States)

Rubin, R.; Simpson, J.; Colgan, S.; Dufour, R.; Citron, R.; Ray, K.; Erickson, E.; Haas, M.; Pauldrach, A.

2007-05-01

H II regions play a crucial role in the measurement of current interstellar abundances. They also serve as laboratories for atomic physics and provide fundamental data about heavy element abundances that serve to constrain models of galactic chemical evolution. We observed emission lines of [S IV] 10.5, H (7-6) 12.4, [Ne II] 12.8, [Ne III] 15.6, & [S III] 18.7 micron cospatially with the Spitzer Space Telescope using the Infrared Spectrograph (IRS) in short-high mode (SH). Here we concentrate on the galaxy M33 and compare the results with our earlier similar study of M83. In each of these substantially face-on spirals, we observed ˜25 H II regions, covering a full range of galactocentric radii (RG). For most of the M33 H II regions, we were able to measure the H (7-6) line while none were detectable in M83. This limited our M83 study to a determination of the Ne++/Ne+, /, and S3+/S++ abundance ratios vs. RG. Angular brackets denote fractional ionizations. As well as having the addition of fluxes for the H(7-6) line, the M33 H II regions are generally of much higher ionization than those in M83, resulting in larger Ne++/Ne+ and S3+/ S++ abundance ratios. For M33, in addition to what we derived for those nebulae in M83, we are also able to derive Ne/H, S/H and Ne/S vs. RG. Important advantages compared with prior optical studies are: 1) the IR lines have a weak and similar electron temperature (Te) dependence while optical lines vary exponentially with Te and 2) the IR lines suffer far less from interstellar extinction. Additionally, these data may be used as constraints on the ionizing spectral energy distribution for the stars exciting these nebulae by comparing the above ionic ratios with predictions using stellar atmosphere models from several different non-LTE model sets. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407

Doğu-Batı Ayrımı Ekseninde Oryantalizm ve Emperyalizm

Directory of Open Access Journals (Sweden)

Erkan DİKİCİ

2014-11-01

Full Text Available Öz Bu çalışma, Doğu ile Batı arasındaki ilişkiyi incelemek adına Edward Said tarafından 1978 yılında kaleme alınan “Oryantalizm” kitabında ifade edilen oryantalist yaklaşımdan yola çıkarak, Doğu-Batı ayrımına vurgu yapmakta ve bu ayrımın arkasında yatan çıkar ilişkilerini dile getirmeye çalışmaktadır. Söz konusu Doğu-Batı ayrımı ile birlikte oryantalizm ile emperyalizm arasındaki ilişkiye de temas edilmek istenmiştir. Bu ilişkiler zinciri içerisinde dile getirdiğimiz bu ayrım, Batılıların, Batılı olmayan toplumlar üzerindeki emperyalist düşünceleri uygulayabilmek amacıyla, Batılıların kendileri tarafından ortaya çıkartılmıştır. Bu nedenle çalışmanın temel amacı, Batılıların, ötekileştirdiği Batı-dışı toplumlar üzerindeki emellerine ulaşmada oryantalizmi biçilmiş kaftan olarak görmekte olduklarını ve oryantalizmi, emperyalizmin meşrulaştırıcısı olarak düşündüklerini ifade etmektir. Anahtar Kelimeler: Oryantalizm, Doğu-Batı Ayrımı, Emperyalizm, Ötekileştirme. Orientalism and Imperialism within the Concept of East-West Division This study emphasizes the East-West division based upon the orientalist approach stated in the book “Orientalism” written by Edward Said in 1978 to study the relation between the East and the West, and tries to depict the relationships based on self-interest underlying this division. With the aforesaid East and West division, it is also wanted to mention the relation between orientalism and Imperialism. The division that we have mentioned has been posed by the Westerners to carry out their imperialist thoughts over non-western societies. For his reason, the main aim of this study is to express that the westerners see orientalism perfectly suited to reach their goals over non-western societies that they have otherized, and they also think orientalism as the legitimization of imperialism. Keywords: Orientalism, East

Helicobacter pylori eradikasyon tedavisinde 7 ve 14 günlük lansoprazol, amoksisilin, klaritromisin protokolünün karşılaştırılması

OpenAIRE

UYGUN, Ahmet; TÜZÜN, Ahmet; YEŞİLOVA, Zeki; ASLAN, Murat; ATEŞ, Yüksel; POLAT, Zülfikar; ERDİL, Ahmet; BAĞCI, Sait; GÜNHAN, Ömer; GÜLŞEN, Mustafa; DAĞALP, Kemal

2015-01-01

Giriş ve amaç: Günümüzde birinci basamak Helicobacter pylori (Hp) eradikasyon tedavisinde protokollerin süresi ve eradikasyon oranları konusunda tartışmalar sürmektedir. Bu çalışmadaki amacımız; nonülser dispepsili Hp pozitif hastalarda lansoprazol, klaritromisin ve amoksisilin'den oluşan 7 ve 14 günlük tedavi protokollerinin eradikasyon oranları nı karşılaştırmaktır. Gereç ve yöntem: Çalışmaya Hp pozitif nonülser dispepsili 188 hasta (92 kadın, 96 erkek, ortalama yaş 44.8 yıl) alı...

Gemi mühendisliği problemlerinin sayısal çözümü için belirsizlik ve hata analizi

OpenAIRE

Gökçe, Metin; Kınacı, Ömer Kemal

2018-01-01

Referansçalışmalar nümerik metotların doğrulanmasını sağlayan en temel ve yaygınçalışmalardır. S175, Kriso Container Ship (KCS), Duisburg Test Case (DTC) veHamburg Test Case (HTC) gibi referans çalışmaların geometrileri ve deney ölçümdeğerleri literatürde mevcuttur. Bu referans çalışmalardan elde edilen değerleryapılansimülasyonların hata ve belirsizliklerini hesaplama imkanı vermekte vebu sayede simülasyonların gerçeği ne ölçüde yansıttığı; eğer yansıtmıyorsa bununnedenleri hakkında önemli b...

The HR diagram for luminous stars in nearby galaxies

International Nuclear Information System (INIS)

Humphreys, R.M.

1978-01-01

Due to the extreme faintness of stars in other galaxies it is only possible to sample the brightest stars in the nearest galaxies. The observations must then be compared with comparable data for the brightest stars, the supergiants and O-type stars, in the Milky Way. The data for the luminous stars are most complete for the Milky Way and the Large Magellanic Cloud. The luminosities for the stars in our Galaxy are based on their membership in associations and clusters, and consequently are representative of Population I within approximately 3kpc of the Sun. The data for the stars in the LMC with spectral types O to G8 come from published observations, and the M supergiants are from the author's recent observations of red stars in the LMC. This is the first time that the M supergiants have been included in an HR diagram of the Large Cloud. The presence of the red stars is important for any discussion of the evolution of the massive stars. (Auth.)

Aileler, Öğretmenler ve Dil ve Konuşma Terapistlerinin Çocuklardaki Dil ve Konuşma Bozukluklarına Yönelik Tutum ve Bilgilerinin Değerlendirilmesi

Directory of Open Access Journals (Sweden)

Bülent TOĞRAM

2015-12-01

Full Text Available Çocuklardaki iletişim sorunları aile bildirimleri, öğretmen raporları ve dil ve konuşma terapistleri (DKT tarafından yapılan değerlendirmeler ile saptanmaktadır. Dil ve konuşma bozukluklarının önlenmesi ve terapisinde işbirliği içinde bulunmaları gereken bu üçlü grubun konuya ilişkin görüş ve tutumları alanyazında önemli bulunmaktadır. Bu çalışmanın amacı, ebeveynlerin, öğretmenlerin ve DKT’lerin dil ve konuşma bozuklukları alanındaki sorumluluk ve rollerini nasıl algıladıklarını, dil ve konuşma bozukluğu olan çocuğun akademik ve sosyal başarısına yönelik tutumlarını, dil ve konuşma bozukluklarının nedenleri ve terapisine yönelik düşüncelerini betimlemektir. Çalışmaya 37 aile bireyi, 46 öğretmen ve 35 DKT katılmıştır. Anket yoluyla elde edilen veriler her grubun konuya ilişkin bilgisini ortaya koymak için karşılaştırılmıştır. Dil ve konuşma bozukluğu olan çocukların akademik/sosyal başarılarına yönelik tutumlarında diğer katılımcı gruplara göre öğretmenlerin, çocukların terapi gereksinimlerine yönelik tutumlarında ise ailelerin daha kararsız tutumlar geliştirdikleri dikkat çekmektedir.Dil ve konuşma bozukluklarının nedenleri ve terapi eksikliklerine yönelik bilgilerinde grupların öncelikli sıralamalarının farklılaştığı görülmüştür

S-24: Hamstring Tendon Otogrefti ile Ön Çapraz Bağ Rekonstrüksiyonu Sonrasında Modifiye ve Hızlandırılmış Fizyoterapi ve Rehabilitasyon Programının Propriosepsiyon Denge ve Koordinasyon Üzerine Etkileri

Directory of Open Access Journals (Sweden)

İbrahim Babayiğit

2017-03-01

Full Text Available Bu çalışmanın amacı; izole ön çapraz bağ (ÖÇB veya ön çapraz bağ ile birlikte menisküs yaralanması geçiren kişilerin, hamstring tendon otogrefti ile ön çapraz bağ rekonstrüksiyonu sonrasında modifiye ve hızlandırılmış fizyoterapi ve rehabilitasyon programının propriosepsiyon, dinamik denge üzerine etkilerini araştırmaktır. Çalışma artroskopik Hamstring Tendon Otogrefti ile Ön Çapraz Bağ Rekonstrüksiyonu Cerrahisi Geçiren 20 kişi (n=20 K/E: 2/18 ile gerçekleştirilmiştir. Tüm olguların operasyon öncesinde (preop diz propriosepsiyon değerleri gözler açık ve kapalı olarak 15, 30, 45 ve 60 derecede Dijital Gonyometre ile ölçüldü. Operasyon sonrası (postop tüm olgular modifiye, hızlandırılmış fizyoterapi ve rehabilitasyon programına alındı. Operasyon sonrası 3., 6., 12. hafta ve 6. Ay’da propriosepsiyon ölçümleri tekrar edildi.Dinamik denge ölçümleri 3., 6., 12. hafta ve 6. Ay’da horizontal, sağ oblik, sol oblik ve tek ayak denge ölçümleri olarak yapıldı. Fonksiyonel seviyelerini değerlendirmek için Lysholm skoru ve ağrıyı değerlendirmek için VAS (Visual Ağrı Skoru, olguların fonksiyonel performansları durumlarını değerlendirmek için tek ayak atlama, çift ayak atlama ve çapraz atlama testleri uygulandı. Çalışmamızda olguların gözler açık ve kapalı durumda propriosepsiyon (15°, 30°, 45° ve 60° ölçüm sonuçları postoperatif dönemde preoperatif döneme göre 12. Hafta ve 6. Ayda istatistiksel olarak anlamlı düzeyde düzelme göstermiştir (p<0.05. Olgularda 3. haftadan sonra dinamik denge testlerinde önemli gelişme saptanmışır, bu artış istatistiksel olarak da anlamlıdır (p<0.05. 6 Ayda yapılan fonksiyonel performans testlerini etkileyen bağımsız değişkenler çoklu regresyon analizinde araştırılmış, 60° ölçülen propriosepsiyon sonuçları ve sol tarafın tek adım atlama test skoru, sağ tarafta tek adım

Estimates of the atmospheric parameters of M-type stars: a machine-learning perspective

Science.gov (United States)

Sarro, L. M.; Ordieres-Meré, J.; Bello-García, A.; González-Marcos, A.; Solano, E.

2018-05-01

Estimating the atmospheric parameters of M-type stars has been a difficult task due to the lack of simple diagnostics in the stellar spectra. We aim at uncovering good sets of predictive features of stellar atmospheric parameters (Teff, log (g), [M/H]) in spectra of M-type stars. We define two types of potential features (equivalent widths and integrated flux ratios) able to explain the atmospheric physical parameters. We search the space of feature sets using a genetic algorithm that evaluates solutions by their prediction performance in the framework of the BT-Settl library of stellar spectra. Thereafter, we construct eight regression models using different machine-learning techniques and compare their performances with those obtained using the classical χ2 approach and independent component analysis (ICA) coefficients. Finally, we validate the various alternatives using two sets of real spectra from the NASA Infrared Telescope Facility (IRTF) and Dwarf Archives collections. We find that the cross-validation errors are poor measures of the performance of regression models in the context of physical parameter prediction in M-type stars. For R ˜ 2000 spectra with signal-to-noise ratios typical of the IRTF and Dwarf Archives, feature selection with genetic algorithms or alternative techniques produces only marginal advantages with respect to representation spaces that are unconstrained in wavelength (full spectrum or ICA). We make available the atmospheric parameters for the two collections of observed spectra as online material.

Heavy hybrid stars from multi-quark interactions

International Nuclear Information System (INIS)

Benic, Sanjin

2014-01-01

We explore the possibility of obtaining heavy hybrid stars within the framework of the two flavor Nambu-Jona-Lasinio model that includes 8-quark interactions in the scalar and in the vector channel. The main impact of the 8-quark scalar channel is to reduce the onset of quark matter, while the 8-quark vector channel acts to stiffen the equation of state at high densities. Within the parameter space where the 4-quark vector channel is small, and the 8-quark vector channel sizeable, stable stars with masses of 2 M ⊙ and above are found to hold quark matter in their cores. (orig.)

VizieR Online Data Catalog: Abundances of 8 RR Lyrae subclass C variable stars (Govea+, 2014)

Science.gov (United States)

Govea, J.; Gomez, T.; Preston, G. W.; Sneden, C.

2016-02-01

We chose 10 candidate RR Lyrae variable stars of subclass c (RRc) stars for spectroscopic observation. Many of these stars were first identified as RRc variables by the All Sky Automated Survey (ASAS) of Pojmanski 2003 (cat. II/264). The target star list included ASAS 144154-0324.7 and ASAS 204440-2402.7. But our spectroscopic study suggest that these two stars are probably W UMa binaries instead of RR Lyrae stars Our spectra were obtained with the echelle spectrograph of the du Pont 2.5m telescope at the Las Campanas Observatory. Four observing runs during 2009-2010 were partly devoted to this project. The spectrograph was used with the 1.5*4'' entrance slit, which translates to a resolving power of R=λ/Δλ~27000 at the MgI b lines near 5180Å. The total continuous wavelength coverage of the spectra was 3500-9000Å. (6 data files).

GAS SURFACE DENSITY, STAR FORMATION RATE SURFACE DENSITY, AND THE MAXIMUM MASS OF YOUNG STAR CLUSTERS IN A DISK GALAXY. II. THE GRAND-DESIGN GALAXY M51

International Nuclear Information System (INIS)

González-Lópezlira, Rosa A.; Pflamm-Altenburg, Jan; Kroupa, Pavel

2013-01-01

We analyze the relationship between maximum cluster mass and surface densities of total gas (Σ gas ), molecular gas (Σ H 2 ), neutral gas (Σ H I ), and star formation rate (Σ SFR ) in the grand-design galaxy M51, using published gas data and a catalog of masses, ages, and reddenings of more than 1800 star clusters in its disk, of which 223 are above the cluster mass distribution function completeness limit. By comparing the two-dimensional distribution of cluster masses and gas surface densities, we find for clusters older than 25 Myr that M 3rd ∝Σ H I 0.4±0.2 , whereM 3rd is the median of the five most massive clusters. There is no correlation withΣ gas ,Σ H2 , orΣ SFR . For clusters younger than 10 Myr, M 3rd ∝Σ H I 0.6±0.1 and M 3rd ∝Σ gas 0.5±0.2 ; there is no correlation with either Σ H 2 orΣ SFR . The results could hardly be more different from those found for clusters younger than 25 Myr in M33. For the flocculent galaxy M33, there is no correlation between maximum cluster mass and neutral gas, but we have determined M 3rd ∝Σ gas 3.8±0.3 , M 3rd ∝Σ H 2 1.2±0.1 , and M 3rd ∝Σ SFR 0.9±0.1 . For the older sample in M51, the lack of tight correlations is probably due to the combination of strong azimuthal variations in the surface densities of gas and star formation rate, and the cluster ages. These two facts mean that neither the azimuthal average of the surface densities at a given radius nor the surface densities at the present-day location of a stellar cluster represent the true surface densities at the place and time of cluster formation. In the case of the younger sample, even if the clusters have not yet traveled too far from their birth sites, the poor resolution of the radio data compared to the physical sizes of the clusters results in measuredΣ that are likely quite diluted compared to the actual densities relevant for the formation of the clusters.

NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

Energy Technology Data Exchange (ETDEWEB)

Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Mace, Gregory N.; McLean, Ian S. [UCLA Division of Astronomy and Astrophysics, Los Angeles, CA 90095 (United States); Young, Michael D.; Rhode, Katherine L. [Department of Astronomy, Indiana University, Swain West 319, 727 East Third Street, Bloomington, IN 47405 (United States); Davy Kirkpatrick, J., E-mail: kluhman@astro.psu.edu [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-12-01

We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C.; Mace, Gregory N.; McLean, Ian S.; Young, Michael D.; Rhode, Katherine L.; Davy Kirkpatrick, J.

2012-01-01

We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

Gazetecilik Meslek İlkelerinin Uygulanmasını Engelleyen Unsurlar ve Çözüm Önerileri / Obstacles on the Practice of the Ethical Principles in Journalism and Some Solutions

Directory of Open Access Journals (Sweden)

Buşra ERİMLİ

2014-07-01

Full Text Available Makalede gazetecilik meslek etik ilkeleri ele alınmıştır. Etik ilkelerin kapsamı ve sınırları incelenmiştir. Bu çerçevede gazetecilerin meslek ilkelerini uygulamasını engelleyen etmenler araştırılmış ve bunlara ilişkin bazı çözüm önerilerine yer verilmiştir. Makalede gazetecilik meslek etik ilkeleri ele alınmıştır. Etik ilkelerin kapsamı ve sınırları incelenmiştir. Bu çerçevede gazetecilerin meslek ilkelerini uygulamasını engelleyen etmenler araştırılmış ve bunlara ilişkin bazı çözüm önerilerine yer verilmiştir.

KENTSEL VE KOLEKTİF BELLEKTE KIRILMALAR VE KAMUSAL ALANIN DÖNÜŞÜMÜ: GİRNE ŞEHRİ LİMANI ÖRNEĞİ

Directory of Open Access Journals (Sweden)

Ümmü ALTAN BAYRAKTAR

2015-09-01

Full Text Available Özet Günümüzde modernleşme ve kapitalizm etkisinde, maddi, toplumsal ve bireysel yaşam büyük bir hız ve ölçekle değişmektedir. Yaşamlarımızın geçtiği mekanların da aynı hız ve ölçekle değişip dönüşmesi, insanların geçmiş ile bugün arasındaki dinamikleri daha fazla sor- gulamasına neden olmuştur. Bu da bellek ve mekan arasındaki ilişkiyi araştırmayı gündeme getirmiş; diğer çalışmaların yanında, kamusal alan olarak kentin ve kentselliğin sürdürülebil- mesini sağlayan kent merkezlerinin çok katmanlı tarihi dokusunun varlığı, geçirdiği değişim ve dönüşümü anlama çabalarını arttırmıştır. Günümüzde ekonomik rasyonalite mantığıy- la atılan adımlar sonucunda tarihsel-kültürel miras ve tarihsel kentsel dokular yitirilmeye başlanmıştır. Bu değişim ve dönüşüm kentsel ve kolektif bellekte kırılmalar yaşanmasına ve kamusal alanların yaşanan mekanlar olmaktan çıkmasına neden olmuştur. Kıbrıs’ın Girne Şehri’nde yer alan ‘Liman’, tarihsel süreç içerisindeki gelişimi, fiziki ve sosyal özellikleriyle kentsel ve kolektif bellekte varolan kırılmalar ve kamusal alanın dönüşümünde mekan ve iktidar açısından bu çalışma kapsamında ele alınmıştır. Çalışmanın kuramsal alt yapısı Jür- gen Habermas’ın Kamusal Alan ve Maurice Halbwachs’ın Kolektif Bellek kavramı üzerine kurulmaya çalışılmıştır.

NuSTAR J033202-2746.8: direct constraints on the Compton reflection in a heavily obscured quasar at z ≈ 2

DEFF Research Database (Denmark)

Del Moro, A.; Mullaney, J. R.; Alexander, D. M.

2014-01-01

We report Nuclear Spectroscopic Telescope Array (NuSTAR) observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (∼400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably......-2746.8, indicating that this source is a heavily obscured quasar (NH = 5.6+−0.80.9 × 1023 cm−2) with luminosity L10-40 keV ≈ 6.4 × 1044 erg s−1. Although existing optical and near-infrared (near-IR) data, as well as follow-up spectroscopy with the Keck and VLT telescopes, failed to provide a secure redshift......-Newton data alone. The measured reflection fraction is higher than the R∼0 typically observed in bright radio-loud quasars such as NuSTAR J033202-2746.8, which has L1.4 GHz≈1027 W Hz−1. Constraining the spectral shape of active galactic nuclei (AGNs), including bright quasars, is very important...

S-05: Düzenli Fiziksel Aktivitenin Dikkat Eksikliği ve Hiperaktivite Bozukluğu Olan Çocuklardaki Etkisinin Araştırılması

Directory of Open Access Journals (Sweden)

Abdülaziz Türksoylu

2017-03-01

Full Text Available AMAÇ: Düzenli fiziksel aktivitenin 8-12 yaş arası Dikkat Eksikliği ve Hiperaktivite Bozukluğu (DEHB tanısı alan ve en az 6 ay stimülan tedavi kullanan çocuklar üzerindeki etkisinin araştırılması amaçlanmıştır.YÖNTEM: Randomize kontrollü olarak planlanan çalışmaya DEHB tanısı alan, 8-12 yaş arası, 46 erkek çocuk dahil edildi. 23 olgu kontrol grubu, diğer 23 olgu ise düzenli fiziksel aktivite (DFA grubu olmak üzere randomize edildi. Tüm olgulara DuPaul DEHB Değerlendirme Ölçeği, Çocuk için Yaşam Kalitesi Ölçeği (ÇİYKÖ 8-12 yaş grubu Ebeveyn ve Çocuk Formu ve Güçler Güçlükler Anketi (GGA uygulandı. Kontrol grubu 10 hafta boyunca mevcut stimülan tedaviyi almaya devam etti ve herhangi bir ek müdahale yapılmadı. DFA grubuna ise en az 60 dakika süren futbol antrenmanı, haftada 3 gün, 10 hafta boyunca yaptırıldı. DFA grubunda, izlemde 19 olgu düzenli fiziksel aktiviteye devam edebilmiş ve çalışmayı tamamlamıştır. 10 hafta sonunda tüm olgulara DuPaul DEHB Değerlendirme Ölçeği, ÇİYKÖ 8-12 yaş grubu Ebeveyn ve Çocuk Formu ve GGA tekrar uygulandı.BULGULAR: Çalışmamızda DFA grubu ve kontrol grubu yaş ortalamaları, DEHB alt tipleri ve Komorbidite dağılımları birbirine benzerdi. DFA grubunun fiziksel aktivite öncesi ve sonrası testleri karşılaştırıldığında; GGA alt ölçeklerinde duygusal, davranış, dikkat eksikliği ve aşırı hareketlilik, akran ilişkileri ve toplam güçlük puanlarında anlamlı azalma (p0,05.SONUÇ: Çalışma sonuçları, düzenli fiziksel aktivitenin stimülan tedavi alan DEHB tanısı olan çocukların DEHB belirtilerini, hastalığın şiddetini ve davranışsal sorunlarını azalttığını, çocukların yaşam kalitesi üzerine olumlu etkileri olduğunu göstermektedir. DEHB olan çocuklarda, stimülan tedaviye ek olarak düzenli fiziksel aktivitenin yapılması iyileşmeye katkıda bulunabilir.

Van Bölge Eğitim ve Araştırma Hastanesi\\'nde Giardia intestinalis ve Entamoeba histolytica/dispar prevalansı: Dört yıllık izlem

OpenAIRE

Bayram, Yasemin; Parlak, Mehmet; Çıkman, Aytekin

2013-01-01

Amaç: Çalışmada dört yıllık sürede Giardia intestinalis ve Entemoeba histolytica/ Entemoeba dispar saptanma oranı, yıllar göre dağılımı ile yaş grupları ve cinsiyete göre dağılımının retrospektif olarak belirlenmesi amaçlanmış­tır. Gereç ve yöntem: Ocak 2008 ile Aralık 2011 tarihleri arasında laboratuvarımıza gönderilen 9911 dışkı örneği parazitolojik yönden incelenmiştir. Taze dışkı örneklerinde Entamoeba sp., Giardia trofozoit ve kistlerinin mikrosko­bik teşhisi i...

Cevher Hazırlama ve Proses Metalurjisi ile İlgili Anılar 3. BÖLÜM Bakır, Kobalt, Çinko ve Nikel Metalürjisi ve Öğrenim Üzerine Notlar

OpenAIRE

REY, Maurice; KARAHAN, Sabri

1989-01-01

1930 yılından önce Katanga'da bakır ve kobalt üzerine yapılan hidrometalurjik araştırmalar, liç tesislerinden atılan artıklardan seçimli çöktürme yoluyla metal eldesini ve uranyum cevherlerinin hidroklorik asitle liç edilmesini içermektedir. Liége'de, 1932-1939 yılları arasında, çinko elektrolizinde kurşun anodların korozyonu ve eser miktardaki kobaltın etkisi araştırılmış, daha sonra da Yeni Kaledonya'dan getirilen yüksek tenörlü nikel matlarının elektrolitik rafinasyonu incel...

RETIRED A STARS AND THEIR COMPANIONS. VII. 18 NEW JOVIAN PLANETS

International Nuclear Information System (INIS)

Johnson, John Asher; Clanton, Christian; Crepp, Justin R.; Howard, Andrew W.; Marcy, Geoffrey W.; Bowler, Brendan P.; Isaacson, Howard; Henry, Gregory W.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Wright, Jason T.

2011-01-01

We report the detection of 18 Jovian planets discovered as part of our Doppler survey of subgiant stars at Keck Observatory, with follow-up Doppler and photometric observations made at McDonald and Fairborn Observatories, respectively. The host stars have masses 0.927 ≤ M * /M ☉ ≤ 1.95, radii 2.5 ≤ R * /R ☉ ≤ 8.7, and metallicities –0.46 ≤ [Fe/H] ≤+0.30. The planets have minimum masses 0.9 M Jup ≤ M P sin i ∼ Jup and semimajor axes a ≥ 0.76 AU. These detections represent a 50% increase in the number of planets known to orbit stars more massive than 1.5 M ☉ and provide valuable additional information about the properties of planets around stars more massive than the Sun.

VE of construction industry

Energy Technology Data Exchange (ETDEWEB)

NONE

1987-10-15

This book gives descriptions of basic of VE of construction industry including doing away with mannerism, necessity of cost reduction, management method of cost reduction, thinking of idea, target of VE, starting VE activity, technical method of VE of construction industry such as thinking of idea with brainstorming, function trade method, new brainstorming, MM method, morphology analysis and lateral thinking, cases of VE of construction industry.

VE of construction industry

International Nuclear Information System (INIS)

1987-10-01

This book gives descriptions of basic of VE of construction industry including doing away with mannerism, necessity of cost reduction, management method of cost reduction, thinking of idea, target of VE, starting VE activity, technical method of VE of construction industry such as thinking of idea with brainstorming, function trade method, new brainstorming, MM method, morphology analysis and lateral thinking, cases of VE of construction industry.

THE 8 μm PHASE VARIATION OF THE HOT SATURN HD 149026b

International Nuclear Information System (INIS)

Knutson, Heather A.; Charbonneau, David; Cowan, Nicolas B.; Agol, Eric; Fortney, Jonathan J.; Showman, Adam P.; Henry, Gregory W.

2009-01-01

We monitor the star HD 149026 and its Saturn-mass planet at 8.0 μm over slightly more than half an orbit using the Infrared Array Camera on the Spitzer Space Telescope. We find an increase of 0.0227% ± 0.0066% (3.4σ significance) in the combined planet-star flux during this interval. The minimum flux from the planet is 45% ± 19% of the maximum planet flux, corresponding to a difference in brightness temperature of 480 ± 140 K between the two hemispheres. We derive a new secondary eclipse depth of 0.0411% ± 0.0076% in this band, corresponding to a dayside brightness temperature of 1440 ± 150 K. Our new secondary eclipse depth is half that of a previous measurement (3.0σ difference) in this same bandpass by Harrrington et al. We re-fit the Harrrington et al. data and obtain a comparably good fit with a smaller eclipse depth that is consistent with our new value. In contrast to earlier claims, our new eclipse depth suggests that this planet's dayside emission spectrum is relatively cool, with an 8 μm brightness temperature that is less than the maximum planet-wide equilibrium temperature. We measure the interval between the transit and secondary eclipse and find that that the secondary eclipse occurs 20.9 +7.2 -6.5 minutes earlier (2.9σ) than predicted for a circular orbit, a marginally significant result. This corresponds to ecos(ω) = -0.0079 +0.0027 -0.0025 , where e is the planet's orbital eccentricity and ω is the argument of pericenter.

Large-scale Star-formation-driven Outflows at 1 3D-HST Survey

Science.gov (United States)

Lundgren, Britt F.; Brammer, Gabriel; van Dokkum, Pieter; Bezanson, Rachel; Franx, Marijn; Fumagalli, Mattia; Momcheva, Ivelina; Nelson, Erica; Skelton, Rosalind E.; Wake, David; Whitaker, Katherine; da Cunha, Elizabete; Erb, Dawn K.; Fan, Xiaohui; Kriek, Mariska; Labbé, Ivo; Marchesini, Danilo; Patel, Shannon; Rix, Hans Walter; Schmidt, Kasper; van der Wel, Arjen

2012-11-01

We present evidence of large-scale outflows from three low-mass (log(M */M ⊙) ~ 9.75) star-forming (SFR > 4 M ⊙ yr-1) galaxies observed at z = 1.24, z = 1.35, and z = 1.75 in the 3D-HST Survey. Each of these galaxies is located within a projected physical distance of 60 kpc around the sight line to the quasar SDSS J123622.93+621526.6, which exhibits well-separated strong (W λ2796 r >~ 0.8 Å) Mg II absorption systems matching precisely to the redshifts of the three galaxies. We derive the star formation surface densities from the Hα emission in the WFC3 G141 grism observations for the galaxies and find that in each case the star formation surface density well exceeds 0.1 M ⊙ yr-1 kpc-2, the typical threshold for starburst galaxies in the local universe. From a small but complete parallel census of the 0.65 0.8 Å Mg II covering fraction of star-forming galaxies at 1 0.4 Å Mg II absorbing gas around star-forming galaxies may evolve from z ~ 2 to the present, consistent with recent observations of an increasing collimation of star-formation-driven outflows with time from z ~ 3.

A SPITZER MIPS STUDY OF 2.5-2.0 M{sub Sun} STARS IN SCORPIUS-CENTAURUS

Energy Technology Data Exchange (ETDEWEB)

Chen, Christine H.; Bitner, Martin [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Pecaut, Mark; Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Su, Kate Y. L., E-mail: cchen@stsci.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

2012-09-10

We have obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 {mu}m and 70 {mu}m observations of 215 nearby, Hipparcos B- and A-type common proper-motion single and binary systems in the nearest OB association, Scorpius-Centaurus. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 {mu}m B+A-type disk fractions of 17/67 (25{sup +6}{sub -5}%), 36/131 (27{sup +4}{sub -4}%), and 23/95 (24{sup +5}{sub -4}%) for Upper Scorpius ({approx}11 Myr), Upper Centaurus Lupus ({approx}15 Myr), and Lower Centaurus Crux ({approx}17 Myr), respectively, somewhat smaller disk fractions than previously obtained for F- and G-type members. We confirm previous IRAS excess detections and present new discoveries of 51 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from L{sub IR}/L{sub *} = 10{sup -6} to 10{sup -2} and grain temperatures ranging from T{sub gr} = 40 to 300 K. In addition, we confirm that the 24 {mu}m and 70 {mu}m excesses (or fractional infrared luminosities) around B+A-type stars are smaller than those measured toward F+G-type stars and hypothesize that the observed disk property dependence on stellar mass may be the result of a higher stellar companion fraction around B- and A-type stars at 10-200 AU. Finally, we note that the majority of the ScoCen 24 {mu}m excess sources also possess 12 {mu}m excess, indicating that Earth-like planets may be forming via collisions in the terrestrial planet zone at {approx}10-100 Myr.

The resolved star formation history of M51a through successive Bayesian marginalization

Science.gov (United States)

Martínez-García, Eric E.; Bruzual, Gustavo; Magris C., Gladis; González-Lópezlira, Rosa A.

2018-02-01

We have obtained the time and space-resolved star formation history (SFH) of M51a (NGC 5194) by fitting Galaxy Evolution Explorer (GALEX), Sloan Digital Sky Survey and near-infrared pixel-by-pixel photometry to a comprehensive library of stellar population synthesis models drawn from the Synthetic Spectral Atlas of Galaxies (SSAG). We fit for each space-resolved element (pixel) an independent model where the SFH is averaged in 137 age bins, each one 100 Myr wide. We used the Bayesian Successive Priors (BSP) algorithm to mitigate the bias in the present-day spatial mass distribution. We test BSP with different prior probability distribution functions (PDFs); this exercise suggests that the best prior PDF is the one concordant with the spatial distribution of the stellar mass as inferred from the near-infrared images. We also demonstrate that varying the implicit prior PDF of the SFH in SSAG does not affect the results. By summing the contributions to the global star formation rate of each pixel, at each age bin, we have assembled the resolved SFH of the whole galaxy. According to these results, the star formation rate of M51a was exponentially increasing for the first 10 Gyr after the big bang, and then turned into an exponentially decreasing function until the present day. Superimposed, we find a main burst of star formation at t ≈ 11.9 Gyr after the big bang.

HDE 229189 - A variable Ae star in the field of NGC 6910

International Nuclear Information System (INIS)

Halbedel, E.M.

1991-01-01

The star HDE 229189 (BD + 40 4145; in the field, though probably not a member, of the open cluster NGC 6910) has been found to exhibit large photometric changes in V magnitude over relatively short time scales. The total observed range was 0.416 V magnitude. An outburst in 1982 showed an even greater V range (Delta V = 1.66) and concomitant color changes. A coude spectrum of the star taken a week before a minor outburst showed emission at H-alpha but no other unusual lines. The star is likely an A3 (V)e star, an unusual object in itself (since stars as late as A3 seldom show emission at H-α), or else possibly a member of a binary system undergoing mass transfer between the members. 19 refs

Dievar Sıcak İş Takım Çeliğinin Delinmesinde Kesme Parametrelerinin Kesme Kuvvetleri Ve Yüzey Kalitesine Etkisinin Regresyon Analiziyle Modellenmesi

Directory of Open Access Journals (Sweden)

İskender Özkul

2013-01-01

Full Text Available Bu çalışmada sıcak iş takım çeliklerinden Dievar derece çeliği üzerinde çeşitli matkaplar ile delik delme esnasında meydana gelen eksenel kuvvetler, kesme momentleri, yüzey pürüzlülükleri, ölçü tamlığı ve dairesellikten sapma değerleri araştırılmıştır. Deneyler dik işleme tezgâhında soğutma sıvısı ile Ø16 mm çaplarında kaplamasız karbür matkap ve kendinden raybalı TiAlN kaplamalı matkap kullanılarak yapılmıştır. Deneylerde ilerleme hızı 0,16 mm/dev, kesme hızı ise 36, 40, 44, 48 m/dak hızları kullanılmıştır. Çıkan sonuçlar doğrusal regresyon metodu ile modellenmiş ve polinom regresyon eğrisi eşitliği anlamlılık değerleri mukayese edilmiştir. Aynı zamanda varyans analizi yapılarak kesme hızı ve matkap tipinin eksenel ilerleme kuvveti, kesme momenti, yüzey pürüzlülüğü ölçü tamlığı ve dairesellikten sapma değeri sonuçları üzerine etkileri incelenmiştir.

Türkiye’de Hayvan Varlığının Mevcut ve Gelecekteki Durumu; TR83 Bölgesi Açılımı

Directory of Open Access Journals (Sweden)

Gülistan Erdal

2016-08-01

Full Text Available Bu çalışmada Türkiye genelinde ve TR83(Amasya, Çorum, Samsun, Tokat bölgesinde büyükbaş ve küçükbaş hayvan varlığı incelenmiştir. Türkiye ve TR83 bölgesinde bulunan büyükbaş ve küçükbaş hayvan varlığını ait 1996-2014 değerleri kullanılarak trend analizi yapılmış ve 2020 yılı tahmini değerleri belirlenmiştir. Çalışmada 2020 yılına ait yapılan projeksiyonlarda yerli sığır ırkının Türkiye genelinde azalmaya devam edeceği görülmektedir. Buna karşın TR83 bölgesinde yerli sığır ırkının artacağı tahmin edilmiştir. Yine araştırmada incelenen tüm hayvan varlıklarının 2020 yılına kadar geçen zamanda artış kaydedeceği tahmin edilmiştir. Kuşkusuz bu artışta Türkiye de uygulanan hayvancılık destekleme politikalarının etkisi yadsınamaz. Bu anlamda mevcut hayvancılık destekleme politikalarının sektöre katkısının ve etkinliğinin saptanması ve aksayan yönlerinin incelenmesi, daha doğru ve etkin politikaların belirlenmesi açısından önemlidir.

Influence of a stellar wind on the evolution of a star of 30 M/sub sun/

International Nuclear Information System (INIS)

Stothers, R.; Chin, C.

1980-01-01

A coarse grid of theoretical evolutionary tracks has been computed for a star of 30 M/sub sun/, in an attempt to delineate the role of mass loss in the star's evolution during core helium burning. For all of the tracks, Cox-Stewart opacities have been adopted, and the free parameters have included the rate of mass loss, criterion for convection, and initial chemical composition. With the use of the Schwarzschild criterion, the star suffers little mass loss during core helium burning and remains almost to the end, a blue supergiant, well separated from main-sequence stars on the H-R diagram. With the use of the Ledoux criterion, the same consequences are obtained only in the case of a relatively low initial hydrogen or initial metals abundance. Otherwise, the star evolves, first, into a red supergiant, whereupon rapid mass loss must be assumed to take place, if the observed paucity of very bright red supergiants is to be accounted for. The stellar remnant then consists of little more than the original helium core, and may appear, for a time, bluer than equally luminous main-sequence stars, provided that the the initial hydrogen and metals abundances are normal. Thus, a wide variety of possible evolutionary tracks can be obtained for an initial mass of 30 M/sub sun/ with reasonable choices of the free parameters

Elektrikli Otomobil, Küresel Rekabet ve Gelişmeler

OpenAIRE

Yılmaz, Fevzi

2017-01-01

Önceki Bilim, Sanayi ve Teknoloji Bakanı Fikri Işık Mayıs 2016'da verdiği beyanatta yerli otomobil projesiyle Google ve Tesla gibi devlerin rakibi olacağımızı belirtmişti. Bakan Işık o tarihte, “Tüm otomotiv devleri, işbirliği için sırada bekliyor. Sonuçta bizim de elimizde önemli teknolojiler var.” diyerek moral tazelemişti. Sözü edilen Google, araç otomasyonu ve sürücüsüz araç projesi yürütmekte iken, Tesla ise dünyanın en büyük farklı konsept elektrikli araç üreticisidir. Tesla'nın CEO’su ...

The formation of galaxies from pregalactic stars

International Nuclear Information System (INIS)

Jones, Janet

1982-01-01

A knowledge of how and when the first stars formed is vital for our understanding of the formation and early evolution of galaxies. Evidence is given that the first stars were pregalactic: indeed, that at least two generations of stars had formed before galaxies collapsed. A model is presented describing the effects of pregalactic stars on galaxy evolution. The first generation -primordial stars- were massive and few in number. A brief description is given for the formation of such a star. The second generation included stars of all masses and involved widespread star formation. Gas ejected from these stars on timescales of 6 x 10 7 to 6 x 10 8 years induced a qualitative change into the dynamics of collapsing perturbations, leading to a characteristic mass of galaxies of 10 10 - 10 12 M 0 . Variations in the rate of gas ejection were responsible for different morphological structures - elliptical and spirals. A few comments are made on some other implications of the model

The star-formation law at GMC scales in M33, the Triangulum Galaxy

Science.gov (United States)

Williams, Thomas G.; Gear, Walter K.; Smith, Matthew W. L.

2018-06-01

We present a high spatial resolution study, on scales of ˜100pc, of the relationship between star-formation rate (SFR) and gas content within Local Group galaxy M33. Combining deep SCUBA-2 observations with archival GALEX, SDSS, WISE, Spitzer and submillimetre Herschel data, we are able to model the entire SED from UV to sub-mm wavelengths. We calculate the SFR on a pixel-by-pixel basis using the total infrared luminosity, and find a total SFR of 0.17 ± 0.06 {M}_⊙/yr, somewhat lower than our other two measures of SFR - combined FUV and 24μ SFR (0.25^{+0.10}_{-0.07} {M}_⊙/yr) and SED-fitting tool MAGPHYS (0.33^{+0.05}_{-0.06} {M}_⊙/yr). We trace the total gas using a combination of the 21cm HI line for atomic hydrogen, and CO(J=2-1) data for molecular hydrogen. We have also traced the total gas using dust masses. We study the star-formation law in terms of molecular gas, total gas, and gas from dust. We perform an analysis of the star-formation law on a variety of pixel scales, from 25" to 500" (100pc to 2kpc). At kpc scales, we find that a linear Schmidt-type power law index is suitable for molecular gas, but the index appears to be much higher with total gas, and gas from dust. Whilst we find a strong scale dependence on the Schmidt index, the gas depletion timescale is invariant with pixel scale.

DİYABETİK RETİNOPATİ PATOGENEZİ VE TEDAVİSİ

OpenAIRE

KURT, FURKAN; ARIKAN, HURİYE; KARADOĞAN, SÜMEYYE; KARAKUŞ, HELİN; KAĞITLI, ESRA NUR; KILIÇ, RAŞİT

2017-01-01

Tüm dünyadaönlenebilir ve / veya tedavi edilebilir en önemli körlük nedenlerinden biriolan diyabetik retinopati (DR), diabetin en önemli komplikasyonlarındanbiridir. Genel popülasyona göre körlük riski 25 kat daha fazladır. Diyabetikretinopati prevelansı tip 1 diyabetli hastalarda %77 iken, tip 2 diyabetikhastalarda ise % 25 civarındadır. Dünya Sağlık Örgütü verilerine göre dünyagenelindeki tüm körlüklerin %4.8 den DR sorumludur. Diyabetik retinopatipatogenezinin anlaşılmasına yönelik yapılan...

PANCHROMATIC HUBBLE ANDROMEDA TREASURY. XVI. STAR CLUSTER FORMATION EFFICIENCY AND THE CLUSTERED FRACTION OF YOUNG STARS

Energy Technology Data Exchange (ETDEWEB)

Johnson, L. Clifton; Sandstrom, Karin [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Dalcanton, Julianne J.; Beerman, Lori C.; Lewis, Alexia R.; Weisz, Daniel R.; Williams, Benjamin F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Fouesneau, Morgan [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Bell, Eric F. [Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Larsen, Søren S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Skillman, Evan D., E-mail: lcj@ucsd.edu [Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2016-08-10

We use the Panchromatic Hubble Andromeda Treasury survey data set to perform spatially resolved measurements of star cluster formation efficiency (Γ), the fraction of stellar mass formed in long-lived star clusters. We use robust star formation history and cluster parameter constraints, obtained through color–magnitude diagram analysis of resolved stellar populations, to study Andromeda’s cluster and field populations over the last ∼300 Myr. We measure Γ of 4%–8% for young, 10–100 Myr-old populations in M31. We find that cluster formation efficiency varies systematically across the M31 disk, consistent with variations in mid-plane pressure. These Γ measurements expand the range of well-studied galactic environments, providing precise constraints in an H i-dominated, low-intensity star formation environment. Spatially resolved results from M31 are broadly consistent with previous trends observed on galaxy-integrated scales, where Γ increases with increasing star formation rate surface density (Σ{sub SFR}). However, we can explain observed scatter in the relation and attain better agreement between observations and theoretical models if we account for environmental variations in gas depletion time ( τ {sub dep}) when modeling Γ, accounting for the qualitative shift in star formation behavior when transitioning from a H{sub 2}-dominated to a H i-dominated interstellar medium. We also demonstrate that Γ measurements in high Σ{sub SFR} starburst systems are well-explained by τ {sub dep}-dependent fiducial Γ models.

Biyolojik Çeşitlilikte Bitki-Böcek Etkileşimi: Tarım Alanları, Doğal ve Yarı Doğal Habitatlar

Directory of Open Access Journals (Sweden)

Gökhan AYDIN

2014-07-01

Full Text Available Bu çalışmada böcek biyolojik çeşitlilik parametrelerinin karşılaştırılması amacı ile Isparta İli Atabey İlçesi'nde mera, ardıç ormanı, ağaçlandırılmış alan, tıbbi ve aromatik bitkiler bahçesi, kiraz ve elma agro-ekosistemleri seçilmiştir. Böceklerin örneklenmesinde kullanılan çukur tuzak örnekleme yönteminden elde edilen veriler kullanılarak, habitatlar arasında benzerlik, çeşitlilik, dominantlık ve populasyon yoğunluk ilişkileri ölçülmüştür. Buna göre çeşitliliğin ve tür zenginliğinin hesaplanmasında kullanılan Shannon-Wiener, Simpson ve Margalef parametre sonuçları en yüksek 2.382, 0.874 ve 4.091 ile ağaçlandırılmış alanda kaydedilmiştir. Habitatlardaki dominantlığın belirlenmesinde kullanılan Simpson dominantlık indeks değeri en yüksek 0.8004 ile mera habitatında kaydedilmiştir. Shannon ve Simpson populasyon yoğunluk ilişkisi en yüksek 0.7951 ve 0.3953 ile ağaçlandırılmış alanda, en düşük ise 0.2253 ve 0.0961 ile mera habitatında hesaplanmıştır. Seçilen habitatlar arasında tür zenginlikleri karşılaştırıldığında kiraz agro-ekosisteminin 25 tür ile en fazla türü bünyesinde barındıran habitat olduğu belirlenmiştir. Habitatlarda yaşayan böcek türleri göz önüne alınarak değerlendirilen sınıflandırma (cluster analiz sonuçlarına göre en benzer habitatların %58.68 ile seçilen iki agro-ekosistem (kiraz ve elma olduğu, ardıç ormanı habitatının ise diğer tüm habitatlara yalnızca %9.98 oranında benzediği hesaplanmıştır. Sonuç olarak Isparta ili Atabey İlçesi'nde belirlenen agro-ekosistemler ile birlikte seçilen doğal ve yarı-doğal habitatların çeşitlilik açısından birbirlerinden farklı olduğu ve kendilerine özgü böcek türlerini bünyelerinde barındırdıkları ayrıca yıpranan ve tarım alanı olarak kullanılan habitatların böcek populasyon yoğunluk ilişkilerinin yıpranmamış ve do

Université de Genève | Séminaire de physique corpusculaire | 8 May

CERN Multimedia

2013-01-01

The PAMELA mission: more than six years of Cosmic Rays investigation, Dr Francesco Cafagna, Bari University and INFN.   Wednesday 8 May, 11:15 am Science III, Auditoire 1S081 30, quai Ernest-Ansermet, 1211 Genève 4 Abstract: The PAMELA mission major scientific objective is the measurements of Cosmic Rays energy spectra, with special focus on the antiparticles, i.e. antiprotons and positrons, ones. The PAMELA apparatus is a satellite borne magnetic spectrometer and comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, and shower tail catcher scintillator. It has been more than six years that the PAMELA mission is taking data in space, on board of the russian satellite Resurs-DK. Important results have been obtained on the positron and antiproton abundance and spectra. Moreover new results have been obtained on the composition of the charged cosmic radiation that challenge our current und...

Elazığ yöresine ait atık tuğla ve kireç taşı tozunun kendiliğinden yerleşen harcın mühendislik özelliklerine etkisi

Directory of Open Access Journals (Sweden)

Merve Açıkgenç

2013-06-01

Full Text Available Bu çalışmanın amacı, kendiliğinden yerleşen harçta (KYH mineral katkı kullanımının harcın dayanım ve viskozite özelliklerine etkisinin araştırılmasıdır. Kendiliğinden yerleşen beton (KYB, geleneksel betona göre daha az iri agrega içerdiğinden KYB tasarımının temelini harç oluşturur. Bu nedenle bu çalışmada harç kullanmak uygun bulunmuştur. Bunun yanı sıra KYB' da gerekli dayanım, dayanıklılık ve uygun bir işlenebilirlik gibi özellikler, iyi bir beton üretimini kaçınılmaz kılmaktadır. Bu özelliklerin sağlanmasında mineral katkı maddelerinin (Silis dumanı, Uçucu kul, kireçtaşı tozu, yüksek fırın cürufu vb. gerekliliği ve belirli miktarda toz malzemenin sağlanmasının, özellikle KYB' da işlenebilirlik ve kıvam açısından şart olduğu yapılan birçok çalışmada ortaya konulmuştur. Ayrıca, düzensiz bir biçimde çevreye bırakılan atıkların çevre sağlığını tehdit etmesini önlemek ve KYB' da kullanılacak toz maddelere yöresel anlamda yenilerini ekleyerek, böylece hem nakliye maliyetinin hem de kireç taşı ve tuğla tozunun çimento azaltılarak kullanımıyla malzeme maliyetin düşürülmesi amaçlanmıştır. Bu amaçla, çimento yerine ikame yöntemiyle Elazığ Yöresi Kireçtaşı Tozu ve Atık Tuğla Tozu birlikte ve ayrı ayrı kullanılarak, toplamda 23 adet harç karışımı oluşturulmuştur. Bu harçların, işlenebilirlik özelliklerini belirlemek ve kendiliğinden yerleşebilirliklerini incelemek amacıyla, mini çökme-yayılma ve mini V-hunisi deneyleri yapılmış, ayrıca harçların viskoziteleri saptanmıştır. Mekanik özellikler için numunelerin 3, 7, 28 ve 91 günlük periyotlarında üç noktalı eğilme ve basınç deneyi yapılmıştır. Ayrıca numuneler üzerinde kapiler su emme deneyi yapılmış ve daha sonra numunelerin toplam su emme, porozite oranları ve yoğunlukları belirlenmiştir.

LANCHESTER DOĞRUSALLIK KANUNU VE BİR PAZARLAMA UYGULAMASI

OpenAIRE

YARALIOĞLU, KAAN

2001-01-01

Bu çalışmada birebir mücadeleler için geliştirilen Lanchester’ in Doğrusallık Kanunu incelenmiştir. Öncelikle formülasyon ve kullanılabilirlik koşulları tanımlanmış ve bir pazarlama uygulaması gerçekleştirilmiştir.

Türk ve Yabancı Futbol Takımlarının Borsa Performansları Üzerine Bir Uygulama

Directory of Open Access Journals (Sweden)

Feyyaz ZEREN

2013-09-01

Full Text Available Bu çalışmanın amacı hisse senetleri borsada işlem gören yerli ve yabancı toplam 8 futbol takımının kendi liglerinde aldıkları maç sonuçları ile borsa performansları arasında bir ilişki olup olmadığını araştırmaktadır. Türk futbol takımlarını Beşiktaş, Galatasaray, Fenerbahçe ve Trabzonspor; yabancı takımları ise Roma, Borussia Dortmund, Olympique Lyon ve Juventus oluşturmaktadır. Çalışmada bu takımların 2007-2011 sezonlarında oynadıkları maçların sonuçları temel alınmıştır. Bu amaca ulaşmak üzere SPSS 15 programında T Testi uygulaması yapılmıştır. Yapılan analiz sonucunda 8 takım içerisinden aldığı galibiyetler ile borsa performansı arasında anlamlı ilişki tespit edilen tek takım Galatasaray olarak çıkmıştır. Mağlubiyetler ile borsa performansı arasında anlamlı ilişki tespit edilen takımlar ise Fenerbahçe, Juventus, Roma ve Borussia Dortmund takımlarıdır.

Başkent Üniversitesi İstanbul Hastanesi’nde çalışan 20-64 yaş arası yetişkin bireylerde şekerli ve tatlandırıcılı içecek tüketiminin enerji alımı ve obezite üzerine etkisi

OpenAIRE

Terzioğlu, Emel

2015-01-01

Bu çalışma bireylerin şekerli ve tatlandırıcılı içecek tüketiminin enerji alımı ve obezite üzerini etkisini incelemek amacıyla yapılmıştır. Çalışma, Ağustos 2014- Kasım 2014 tarihleri arasında Başkent Üniversitesi İstanbul Hastanesi’nde doktor, hemşire ve diğer sağlık personeli ile hasta danışmanı olarak çalışan, yaşları 16-48 arasında değişen 100 ( 82 kadın, 18 erkek) sağlıklı birey üzerinde yürütülmüştür. Bireylerin kişisel bilgileri, genel sağlık durumları, yaşam tarzı alışkanlıkları ve te...

Sıklık Bakımının Doğal Sarıçam (Pinus sylvestris L. Meşcerelerinde Çap ve Göğüs Yüzeyi Üzerine Etkisi

Directory of Open Access Journals (Sweden)

Ömer ÖNCÜL

2016-07-01

Full Text Available Bu çalışmada, idare süresi sonunda işletme amacına uygun nitelikte ve ekonomik getirisi yüksek meşcereler oluşturabilmek için, sıklık çağındaki doğal sarıçam meşcerelerinde bakım tedbirleri sonucu, hektarda olması gereken göğüs yüzeyi miktarını ve birey sayısını belirlemek amaçlanmıştır. Bu amaçla Sarıkamış ve Ardahan’da belirlenen iki deneme alanında (18-20 yaş aralığında dört işlem (kontrol, zayıf, orta ve kuvvetli müdahale işlemi ve üç tekerrürden oluşan her biri 500 m²’lik toplam 24 parsel oluşturulmuştur. Zayıf müdahale parselinde alandaki toplam göğüs yüzeyinin %10-15’i, orta müdahale parselinde %20-25’i ve kuvvetli müdahale parselinde ise %30-35’i çıkarılmış, kontrol parsellerinde herhangi bir müdahale yapılmamıştır.  Deneme parsellerindeki bireylerde 2010 yılı ilkbaharında başlangıç çap değerleri ölçülmüş ve işlemlere göre müdahale kesimleri yapılarak, 2013 yılı ilkbaharındaki çap değerleri ile karşılaştırılıp her iki müdahale yılı arasındaki gelişim farkı tespitleri yapılmıştır. Elde edilen sonuçlara göre; yapılan sıklık bakımı müdahalelerinin gelişmeye etkisinin olduğu ve bu etkinin çap ve göğüs yüzeyi değerleri açısından en iyi gelişiminin kuvvetli müdahale işleminde gerçekleştiği tespit edilmiştir. Çalışma sonucunda, genel olarak 18-20 yaşlarındaki doğal sarıçam meşcerelerinde sıklık bakımı yapılan alanlarda ilk sıklık bakımı kesimlerinde hektardaki birey sayısının 3000-4000 adet civarında tutulması çap ve göğüs yüzeyi açısından en iyi sonucu vermektedir.Anahtar Kelimeler: Çap, göğüs yüzeyi, sarıçam, sıklık bakımı.

METAL-POOR STARS OBSERVED WITH THE MAGELLAN TELESCOPE. I. CONSTRAINTS ON PROGENITOR MASS AND METALLICITY OF AGB STARS UNDERGOING s-PROCESS NUCLEOSYNTHESIS

Energy Technology Data Exchange (ETDEWEB)

Placco, Vinicius M.; Rossi, Silvia [Departamento de Astronomia-Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Sao Paulo, SP 05508-900 (Brazil); Frebel, Anna [Massachusetts Institute of Technology and Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Beers, Timothy C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Karakas, Amanda I.; Kennedy, Catherine R. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Christlieb, Norbert [Zentrum fuer Astronomie der Universitaet Heidelberg, Landessternwarte, Koenigstuhl 12, D-69117 Heidelberg (Germany); Stancliffe, Richard J. [Argelander-Institut fuer Astronomie der Universitaet Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany)

2013-06-20

We present a comprehensive abundance analysis of two newly discovered carbon-enhanced metal-poor (CEMP) stars. HE 2138-3336 is a s-process-rich star with [Fe/H] = -2.79, and has the highest [Pb/Fe] abundance ratio measured thus far, if non-local thermodynamic equilibrium corrections are included ([Pb/Fe] = +3.84). HE 2258-6358, with [Fe/H] = -2.67, exhibits enrichments in both s- and r-process elements. These stars were selected from a sample of candidate metal-poor stars from the Hamburg/ESO objective-prism survey, and followed up with medium-resolution (R {approx} 2000) spectroscopy with GEMINI/GMOS. We report here on derived abundances (or limits) for a total of 34 elements in each star, based on high-resolution (R {approx} 30, 000) spectroscopy obtained with Magellan-Clay/MIKE. Our results are compared to predictions from new theoretical asymptotic giant branch (AGB) nucleosynthesis models of 1.3 M{sub Sun} with [Fe/H] = -2.5 and -2.8, as well as to a set of AGB models of 1.0 to 6.0 M{sub Sun} at [Fe/H] = -2.3. The agreement with the model predictions suggests that the neutron-capture material in HE 2138-3336 originated from mass transfer from a binary companion star that previously went through the AGB phase, whereas for HE 2258-6358, an additional process has to be taken into account to explain its abundance pattern. We find that a narrow range of progenitor masses (1.0 {<=} M(M{sub Sun }) {<=} 1.3) and metallicities (-2.8 {<=} [Fe/H] {<=}-2.5) yield the best agreement with our observed elemental abundance patterns.

EDEBİYAT MÜZELERİ VE MÜZEDE EDEBİYAT EĞİTİMİ

OpenAIRE

ADIGÜZEL, Ferah BURGUL

2017-01-01

Edebiyat müzeleri, edebiyatın toplumdaki rolünü müze ortamlarında tanıtır, korur ve ileterek etkileşimli bir öğrenme olanağı sunar. Türkiye’de kapsam ve işlev açısından tam anlamıyla edebiyat müzesi olarak adlandırılan bir müze olmamakla birlikte, yazar müze evleri, müze kütüphaneleri ve somut olmayan kültürel miras müzeleri gibi azımsanmayacak sayıda edebiyat ile ilgili müze olduğu görülmektedir. Bu çalışmanın amacı, edebiyat müzesi kavramı doğrultusunda Türkiye’deki edebiyat müzelerini türl...

The VE/CAD synergism

International Nuclear Information System (INIS)

Sperling, R.B.

1993-01-01

Value Engineering (VE) and Computer-Aided Design (CAD) can be used synergistically to reduce costs and improve facilities designs. The cost and schedule impacts of implementing alternative design ideas developed by VE teams can be greatly reduced when the drawings have been produced with interactive CAD systems. To better understand the interrelationship between VE and CAD, the fundamentals of the VE process are explained; and example of a VE proposal is described and the way CAD drawings facilitated its implementation is illustrated

By Draconis Stars

Science.gov (United States)

Bopp, Bernard W.

An optical spectroscopic survey of dK-M stars has resulted in the discovery of several new H-alpha emission objects. Available optical data suggest these stars have a level of chromospheric activity midway between active BY Dra stars and quiet dM's. These "marginal" BY Dra stars are single objects that have rotation velocities slightly higher than that of quiet field stars but below that of active flare/BY Dra objects. The marginal BY Dra stars provide us with a class of objects rotating very near a "trigger velocity" (believed to be 5 km/s) which appears to divide active flare/BY Dra stars from quiet dM's. UV data on Mg II emission fluxes and strength of transition region features such as C IV will serve to fix activity levels in the marginal objects and determine chromosphere and transition-region heating rates. Simultaneous optical magnetic field measures will be used to explore the connection between fieldstrength/filling-factor and atmospheric heating. Comparison of these data with published information on active and quiet dM stars will yield information on the character of the stellar dynamo as it makes a transition from "low" to "high" activity.

Hearily reddened Hg-Mn star HD 29647

International Nuclear Information System (INIS)

Strajzhis, V.; Glagolevskij, Yu.V.; Romanyuk, I.I.; Bychkov, V.D.; AN SSSR, Nizhnij Arkhyz. Spetsial'naya Astrofizicheskaya Observatoriya)

1982-01-01

A heavily reddened HD 29647 (V=8sup(m).4) star is investigated using the 6-meter telescope spectrograms with dispersions 9 and 28 A/mm and photometric observations in the Vilnius seven- color system. Parameters Tsub(e)=15600 K (corresponding spectral type B5) and log g=3.70 from hydrogen lines and Balmer jump were obtained. HD 29647 is a peculiar star of the Hg-Mn type. The radial velocity of the star is+14.1+-1.0 km/s, almost identical with that of the dark Taurus cloud and its T Tauri-type variables. If the star is near the front edge of the dark cloud at the distance of 165 pc and has Esub(B-V)=1.06, its visual absolute magnitude is - 0sup(m).9. Photometric observations permit to suspect a slight varia bility in the U, P, and X colors [ru

Geçmişten Günümüze Edebiyat Ders Planlarında Ve Kitaplarında Yahya Kemal ve Şiirleri From The Past Till Present Day Yahya Kemal And His Poets In Literature Curriculums And Course Books

Directory of Open Access Journals (Sweden)

Tevfik SÜTÇÜ

2013-07-01

prepared within the framework of literature curriculums ofTurkish Language and Literature course. Türk Edebiyatının XX. yüzyılda yetiştirdiği önemli şairlerinden biri Yahya Kemal Beyatlı’dır. Yahya Kemal, yaşadığı dönemin siyasi, sosyal ve tarihî hadiselerinin içinde yer almasının yanında, Türk edebiyatı ile ilgili önemli ve dikkat çekici hassasiyetleri olan bir şairimizdir. Bütün bu özellikleri ile birlikte Yahya Kemal, Türk şairleri arasında meydana getirdiği eserleri ile Türk dilinin güzel şiir örneklerini vermiş bir şahsiyettir. O, şiirlerinde ele aldığı farklı temaların yanında, şiirlerini meydana getirirken kullandığı dil, biçim ve şekil özellikleri ile öne çıkmış ve şairin bu özelliği hemen her dönemin edebiyat araştırmacıları ve eleştirmenleri tarafından kabul ve teslim edilmiştir.Öğretim kurumlarımızda edebiyat derslerinde edebiyatın diğer türleri ile beraber şiirle ilgili estetik beğenilerin geliştirilmesi ve edebiyat bilgilerinin öğretilmesi hedeflenir. Ülkemizde 1924’ten itibaren okullarımızda bütün diğer ders programları ile beraber edebiyat programlarını yeniden düzenleme çalışmaları da başlar. Cumhuriyet döneminde edebiyat öğretimindeki yönelimlerden birisi, edebiyat derslerinde okutulacak metinlerin çağdaş sanatçıların eserlerinden seçilmesi gerektiği yönündedir. Bu itibarla öğrencilere okuduklarından zevk alması ve yaşayan dilin örnekleriyle karşılaştırılması yanında, bazı metinlerden hareketle edebiyattaki tür ve şekil bilgisine ait konuların öğretilmesi, kavratılması ve tanıtılması mümkün olacaktır. Bütün bu özelliklere sahip olan Yahya Kemal’in eserlerinin ve metinlerinin, okul ders kitaplarında hemen her zaman yer alması isabetli bir tercih olmuştur ve olacaktır.Bu makalede, hangi yıllardan itibaren ve hangi dönemlerde Yahya Kemal’in hangi eserlerinin yoğun olarak ders kitaplarında yer ald

ON THE INCONSISTENCY BETWEEN COSMIC STELLAR MASS DENSITY AND STAR FORMATION RATE UP TO z ∼ 8

Energy Technology Data Exchange (ETDEWEB)

Yu, H.; Wang, F. Y., E-mail: fayinwang@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

2016-04-01

In this paper, we test the discrepancy between the stellar mass density (SMD) and instantaneous star formation rate in the redshift range 0 < z < 8 using a large observational data sample. We first compile the measurements of SMDs up to z ∼ 8. Comparing the observed SMDs with the time-integral of instantaneous star formation history (SFH), we find that the observed SMDs are lower than that implied from the SFH at z < 4. We also use the Markov chain Monte Carlo (MCMC) method to derive the best-fitting SFH from the observed SMD data. At 0.5 < z < 6, the observed star formation rate densities are larger than the best-fitting one, especially at z ∼ 2 where they are larger by a factor of about two. However, at lower (z < 0.5) and higher redshifts (z > 6), the derived SFH is consistent with the observations. This is the first time that the discrepancy between the observed SMD and instantaneous star formation rate has been tested up to very high redshift z ≈ 8 using the MCMC method and a varying recycling factor. Several possible reasons for this discrepancy are discussed, such as underestimation of SMD, initial mass function, and evolution of cosmic metallicity.

ON THE INCONSISTENCY BETWEEN COSMIC STELLAR MASS DENSITY AND STAR FORMATION RATE UP TO z ∼ 8

International Nuclear Information System (INIS)

Yu, H.; Wang, F. Y.

2016-01-01

In this paper, we test the discrepancy between the stellar mass density (SMD) and instantaneous star formation rate in the redshift range 0 < z < 8 using a large observational data sample. We first compile the measurements of SMDs up to z ∼ 8. Comparing the observed SMDs with the time-integral of instantaneous star formation history (SFH), we find that the observed SMDs are lower than that implied from the SFH at z < 4. We also use the Markov chain Monte Carlo (MCMC) method to derive the best-fitting SFH from the observed SMD data. At 0.5 < z < 6, the observed star formation rate densities are larger than the best-fitting one, especially at z ∼ 2 where they are larger by a factor of about two. However, at lower (z < 0.5) and higher redshifts (z > 6), the derived SFH is consistent with the observations. This is the first time that the discrepancy between the observed SMD and instantaneous star formation rate has been tested up to very high redshift z ≈ 8 using the MCMC method and a varying recycling factor. Several possible reasons for this discrepancy are discussed, such as underestimation of SMD, initial mass function, and evolution of cosmic metallicity

Gemini Spectra of Star Clusters in the Spiral Galaxy M101

Science.gov (United States)

Simanton-Coogan, Lesley A.; Chandar, Rupali; Miller, Bryan; Whitmore, Bradley C.

2017-12-01

We present low resolution, visible light spectra of 41 star clusters in the spiral galaxy M101, taken with the Gemini/GMOS instrument. We measure Lick indices for each cluster and compare with BaSTI models to estimate their ages and metallicities. We also measure the line-of-sight velocities. We find that 25 of the clusters are fairly young massive clusters (YMCs) with ages of hundreds of millions of years, and 16 appear to be older, globular clusters (GCs). There are at least four GCs with best-fit ages of ≈1–3 Gyr and eight with best-fit ages of ≈5–10 Gyr. The mean metallicity of the YMCs is [Fe/H] ≈ ‑0.1 and for the GCs is [Fe/H] ≈ ‑0.9. We find a near-continuous spread in both age and metallicity for our sample, which may indicate that M101 had a more-or-less continuous history of cluster and star formation. From the kinematics, we find that the YMCs rotate with the H I gas fairly well, while the GCs do not. We cannot definitively say whether the GCs sampled here lie in an inner halo, thick disk, or bulge/psuedobulge component, although given the very small bulge in M101, the last seems unlikely. The kinematics and ages of the YMCs suggest that M101 may have undergone heating of its disk or possibly a continuous merger/accretion history for the galaxy.

The role of the CNO-cycle in M- and C-stars

International Nuclear Information System (INIS)

Irgens-Jensen, S.

1976-01-01

Compositions of red giant atmospheres have been calculated assuming an envelope in which solar abundances have been mixed with CNO-processed material from the interior. Seven cases were studied, the difference between them being the length of time, during which the interior material had been exposed to the CNO-process. The possible atomic and molecular abundaces for each case were calculated as a function of the amount of mixing between envelope and interior material. Four of the cases would be able to evolve into carbon stars if the mixing were extensive enough. The changeover in spectral appearance should be quite quick as the star evolves from type M to type C. We examine a number of molecular ratios which could be used as indicators of such an impending changeover. However, the atomic ratios which result from the mixing are in desagreement with most such ratios which result from the mixing are in disagreement with most such ratios which have been measured up till now in both oxygen and carbon stars. This is probably an indication that CNO-cycled material is not an important contributor to stellar atmospheres. (orig.) [de

ELEVEN NEW HEAVILY REDDENED FIELD WOLF–RAYET STARS

International Nuclear Information System (INIS)

Smith, J. D. T.; Cushing, Michael; Barletta, Anthony; McCarthy, Don; Kulesa, Craig; Van Dyk, Schuyler D.

2012-01-01

We report the results of a medium-narrowband 2 μm line survey covering 5.8 deg 2 near the Galactic plane. We confirm 11 new field Wolf-Rayet stars along three lines of sight probing the inner Galaxy, demonstrating the capability to uncover distant and highly reddened populations of Galactic wind-borne emission-line stars suffering extinction as high as A V ∼ 40 and as distant as 9 kpc down to modest magnitude limits of K s ∼ 12.5. All stars are of subtype WC7-8, with median distance d = 6 kpc and median extinction A K s = 2.5. Over the fields surveyed, the density of Wolf-Rayet stars to limiting magnitude K s ∼ 12.5 was found to be 1.9 deg –2 . We compare this to models which predict their distribution within the Galaxy and find that, even neglecting survey and subtype incompleteness, they consistently underpredict the number of newly discovered stars along the surveyed lines of sight.

Berkeley 51 Kümesinin Temel ve Astrofiziksel Parametrelerinin Belirlenmesi

Directory of Open Access Journals (Sweden)

İnci Akkaya Oralhan

2016-10-01

Full Text Available Galaksimizin birinci çeyreğinde bulunan ve daha önce çok az çalışılmış açık yıldız kümelerinden biri olan Berkeley 51 kümesinin temel astrofiziksel ve yapısal parametreleri CCD UBV(RIC ve 2MASS JHKS verileri kullanılarak elde edilmiştir. Kümeye ait CCD UBV(RIC verileri Meksika’da bulunan San Pedro Martir Ulusal Gözlemevi’nden 84cm’lik teleskop ile alınmıştır. Küme üyeliklerinin belirlenmesinde ise PPMXL kataloğundaki öz hareket verileri kullanılmıştır. Buna küre bu küme için elde edilen limit yarıçap Rlim=2.5 yay dakikası, kızarma E(B-V=0.85±0.05 kadir, E(J-H=0.28±0.02 kadir, uzaklık modülü DM=(m-M0=10.66±0.04 pc, uzaklığı d=1355±27 pc ve logaritmik yaş log(A=9.54±0.03 Myıl olarak bulunmuştur. Küme için ilk kez bulunan metal ve ağır element bolluğu ise sırasıyla [Fe/H]=-0.38 ve Z=0.006 olarak elde edilmiştir.Anahtar kelimeler: Açık yıldız kümeleri-Berkeley 51

Explosion of a low mass neutron star

International Nuclear Information System (INIS)

Blinnikov, S.I.; Imshennik, V.S.; Nadyozhin, D.K.; Novikov, I.D.; Polnarev, A.G.; AN SSSR, Moscow. Fizicheskij Inst.); Perevodchikova, T.V.

1990-01-01

The hydrodynamical disruption of a low mass neutron star is investigated for the case when the stellar mass becomes smaller than the minimum value, M min ≅0.1 M sun . The final phase of the process is shown to proceed explosively, leading to an expansion of all the star, with a kinetic energy of 4.8 MeV per nucleon. The results of calculations are virtually independent of the way in which the neutron star mass goes down below M min (mass exchange in a close binary stellar system, nucleon decay, or some effective mass loss due to a hypothetical decrease of the gravitational constant). The neutron star disruption is followed by a short (0.01-0.1 s) burst of thermal hard X-rays and soft gamma-rays (kT=10-100 keV) with a subsequent much more prolonged tail of radiation induced by decays of long-lived radioactive nuclides. Some fraction of the explosion energy may be emitted in the form of neutrinos. (orig.)

KARE KESİTLİ HELİSEL KANALDA TÜRBÜLANSLI AKIŞTA BASINÇ DÜŞÜŞÜNÜN DENEYSEL VE NÜMERİK ANALİZİ

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Okyar KAYA

2004-02-01

Full Text Available Bu çalışmada 8 x 8 mm kare kesitli, 12 mm hatveli helisel kanalda basınç düşüşü deneysel olarak tespit edilerek benzer sınır şartlarında bilgisayarda nümerik çözüm yapılmıştır. Nümerik çözüm FLUENT ® programı ile SIMPLE çözüm algoritması, PRESTO basınç-hız enterpolasyon yöntemi, RNG k-? türbülans modeli ve Gauss Siedel iterasyon metodu kullanılarak yapılmıştır. Nümerik ve deneysel veriler arasında en fazla % 5 gibi bir fark vardır. Deneysel ve nümerik sonuçlar literatürde yayınlanmış çözümler ile karşılaştırılarak valide edilmiştir.

Membran Distilasyon ve Ozmotik Distilasyon ile Meyve Suyu Konsantrasyonu

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Pelin Onsekizoğlu

2015-02-01

Full Text Available Geleneksel termal evaporasyonla meyve suyu konsantresi üretiminde uygulanan yüksek sıcaklıklar, uçucu aroma maddeleri, vitaminler ve diğer besin öğelerinde kayıplar, pişmiş tat oluşumu, renk bozulması ve insan sağlığı üzerinde olumsuz etkilere neden olmaktadır. Geleneksel uygulamaların yerini almak üzere, hem iyi kalitede hem de güvenilir ürün üretimine olanak tanıyan alternatif konsantrasyon teknolojileri gün geçtikçe önem kazanmaktadır. Bu teknolojiler arasında, membran distilasyon ve ozmotik distilasyon gibi membran uygulamaları meyve sularının oda sıcaklığında veya buna yakın sıcaklıklarda 60-65 ˚Briks ve hatta daha yüksek seviyelere konsantrasyonuna olanak sağlamaları bakımından ön plana çıkmışlardır. Çalışmada, taze ürün karakteristiklerine yakın ürün üretiminde gelecek vadeden bu membran uygulamalarının temel ilkeleri ve meyve suyu sanayinde kullanım potansiyelleri hakkında bilgi verilmiştir.

STAR TREK elab ja õilmitseb / Scott Abel

Index Scriptorium Estoniae

Abel, Scott

2009-01-01

Artikli autor käis Bonnis "Star Treki" (USA, 1966-1969) fännide iga-aastasel kokkutulekul. Artiklis sellest, kuidas kulttussari on mõjutanud inimesi, kultuuri, meediat. Meenutavad näitleja Nichelle Nichols ja teismelisena sarja looja Gene Roddenberry juures vabatahtliku abilisena töötanud Richard Arnold. Sarja algusest, järgprojektidest ("Star Trek : The Next Generation", "Deep Space Nine" jt.) kuni J. J. Abramsi filmini, mis esilinastus 8. mail

FEMİNİST ULUSLARARASI İLİŞKİLER VE ULUSLARARASI İLİŞKİLER ELEŞTİRİSİ: CİNSİYET, DEVLET VE GÜVENLİK

OpenAIRE

DOĞAN, Fazlı; ÖZLÜK, Duygu

2016-01-01

Bu çalışma bir sosyal ve politik teori olarak Feminizm’in Uluslararası İlişkilere (Uİ) girişi ve Feminist Uİ’nin ana akım Uİ teorilerine cinsiyet, devlet ve güvenlik başlıkları üzerinden yönelttiği eleştirileri değerlendirmektedir. Üç ana bölümden oluşan çalışmada öncelikle bir sosyal ve politik teori ve bir hareket olarak feminizmin tarihsel gelişimi kısaca tartışılmıştır. İkinci bölümde feminist hareketlerin uluslararası ilişkilerdeki gelişimi ve bir Uİ teorisi olarak Feminist Uİ’nin genel ...

P-15: U-19 Futbol Takımı Oyuncularının Aerobik Kapasite ve Süratlerinin, Alt Ekstremite İzokinetik Kas Kuvveti ile İlişkilendirilmesi

Directory of Open Access Journals (Sweden)

Gökhan Deliceoğlu

2017-03-01

Full Text Available Araştırmanın amacını U-19 futbol takımı oyuncularının aerobik kapasite ve süratlerinin, alt ekstremite kuvveti ile ilişkilendirilmesi oluşturmaktadır. Araştırmaya U-19 kategorisindeki (Xyaş=18,17±0,53 yıl; Xva=73,16±5,95 kg; Xbu=178,22 ± 5,95 cm 15 futbolcu katıldı. Futbolcuların aerobik kapasiteleri Cosmed K5 © ile, alt ekstremite hamstring (H ve quadriseps (Q kas kuvvetleri ISOMED 2000 © İzokinetik Cihazı ile, sürat değerleri optojump © cihazı ile ölçüldü. Diz fleksör ve ekstansör kaslarının kas kuvveti 60°/sn açısal hızda 5 tekrarla, diz ekstansörlerinin kassal enduransı 180°/sn açısal hızda 30 tekrarla değerlendirildi. Futbolcular bir saat dinlendikten sonra, 10 dakika ısındı ve sonra ortalama hızın elde edilmesi için Optojump ile 30 m sürat testi iki kez uygulandı. Sporcular aerobik kapasitelerinin ölçülmesi için Cosmed K5 cihazı ile Bruce protokolünde koşturuldu. Futbolcuların maxVO2 ve ortalama hız değeri ile baskın ve baskın olmayan taraf diz fleksör ve ekstansör kaslarının kas kuvveti ile diz ekstansörlerinin kassal enduransı arasındaki ilişkinin belirlenmesi için SPSS 17,0’de regresyon analizi yapıldı. Analiz sonuçlarına göre, maxVO2 (X=51,84±7,56 ml/dk/kg ile baskın taraf 60 °/sn açısal hızdaki (Xfle=137,01 ±35,48 Nm; Xeks=239,26 ±57,96 Nm kuvvet değerleri arasında istatistiksel olarak anlamlı bir ilişki görüldü (R=759, R2=,576, p0.05. Futbolculardan elde edilen maxVO2 değerleri ile baskın olmayan taraf 60°/sn açısal hızdaki temel kas kuvveti (Xfle=140,62 ±34,11 Nm; Xeks=253,21 ±71,54 Nm ile 180/sn açısal hızda baskın taraf (X=66,86±8,16 ve baskın olmayan taraf kassal endurans (X=66,43±10,26 değerleri arasında anlamlı bir ilişki görülmedi (p>0.05. Futbolcularda baskın taraf diz fleksör ve ekstensör izokinetik kas kuvvet değerleri ile maxVO2 ve ortalama sürat değerleri arasında anlamlı bir ilişki g

Clinical, immunological and treatment-related factors associated with normalised CD4+/CD8+ T-cell ratio: effect of naïve and memory T-cell subsets.

LENUS (Irish Health Repository)

Tinago, Willard

2014-01-01

Although effective antiretroviral therapy(ART) increases CD4+ T-cell count, responses to ART vary considerably and only a minority of patients normalise their CD4+\\/CD8+ ratio. Although retention of naïve CD4+ T-cells is thought to predict better immune responses, relationships between CD4+ and CD8+ T-cell subsets and CD4+\\/CD8+ ratio have not been well described.

THE COMPACT STAR-FORMING COMPLEX AT THE HEART OF NGC 253

Energy Technology Data Exchange (ETDEWEB)

Davidge, T. J., E-mail: tim.davidge@nrc.ca [Dominion Astrophysical Observatory, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

2016-02-20

We discuss integral field spectra of the compact star-forming complex that is the brightest near-infrared (NIR) source in the central regions of the starburst galaxy NGC 253. The spectra cover the H and K passbands and were recorded with the Gemini NIR Spectrograph during subarcsecond seeing conditions. Absorption features in the spectrum of the star-forming complex are weaker than in the surroundings. An absorption feature is found near 1.78 μm that coincides with the location of a C{sub 2} bandhead. If this feature is due to C{sub 2} then the star-forming complex has been in place for at least a few hundred Myr. Emission lines of Brγ, [Fe ii], and He i 2.06 μm do not track the NIR continuum light. Pockets of star-forming activity that do not have associated concentrations of red supergiants, and so likely have ages <8 Myr, are found along the western edge of the complex, and there is evidence that one such pocket contains a rich population of Wolf–Rayet stars. Unless the star-forming complex is significantly more metal-poor than the surroundings, then a significant fraction of its total mass is in stars with ages <8 Myr. If the present-day star formation rate is maintained then the timescale to double its stellar mass ranges from a few Myr to a few tens of Myr, depending on the contribution made by stars older than ∼8 Myr. If—as suggested by some studies—the star-forming complex is centered on the galaxy’s nucleus, which presumably contains a large population of old and intermediate-age stars, then the nucleus of NGC 253 is currently experiencing a phase of rapid growth in its stellar mass.

Tarım İşletmelerinde Buğday Tohumu Kullanımı ve Sorunları: Burdur ve Isparta İlleri Örneği

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Hülya Gül

2015-09-01

Full Text Available Çalışmanın temel hedefi Isparta-Burdur illerinde buğday üretimindeki tohum kullanım yapısının tespiti ve üretimin geliştirilmesidir. Araştırmada kullanılan birincil veriler, bölgede buğday yetiştiriciliği yapan işletmelerden anket yöntemi ile elde edilmiştir. Buğday yetiştiriciliği yapan 150 işletmeden elde edilen veriler 2011 üretim dönemine aittir. Buğday üretiminde işletme genel ortalamasında işletmecilerin karşılaştığı sorunların başında ürün fiyatının düşük olması, girdi fiyatlarının yüksekliği gelmektedir. İşletmecilerin buğday üretiminin geliştirilmesinin, üretimde kullanılan mazot, ilaç, gübre gibi girdi maliyetlerinin düşürülmesi ile sağlanabileceğini ifade etmişlerdir. Buğday tarımında tohum ilaçlaması bölgede işletmelerin %97,3’ünde yapılmaktadır. Buğday tarımında üretim sonrası buğday ürününün depolama durumu ise görüşülen işletmelerin %52,7’sinde söz konusudur. İşletmelerin %74,7’si yetiştirdiği buğday çeşidini bilmektedir. İşletmelerin %52’sinde de sertifikalı tohum kullanımının olduğu saptanmıştır. Sertifikalı tohum kullanım oranı Isparta ilinde daha yüksektir (%69,3. İstatistikî olarak da iller arasında sertifikalı tohum kullanımında farklılık bulunmaktadır. Bölgede işletmelerin sertifikalı tohum kullanımı konusunda yeterli bilgiye sahip olmadığı saptanmıştır. Dolayısıyla bu konuda yayımcılar tarafından üreticiye bilgi aktarımı gerekmektedir.

VizieR Online Data Catalog: CTIO/DECam photometry of RR Lyrae stars in M5 (Vivas+, 2017)

Science.gov (United States)

Vivas, A. K.; Saha, A.; Olsen, K.; Blum, R.; Olszewski, E. W.; Claver, J.; Valdes, F.; Axelrod, T.; Kaleida, C.; Kunder, A.; Narayan, G.; Matheson, T.; Walker, A.

2017-11-01

Observations were obtained during 2013 (2013 Jun 7-9, and 2013 Jun 21) and 2014 (2014 Mar 7-9) with the Dark Energy Camera (DECam) imager on the 4m Blanco Telescope at Cerro Tololo Inter-American Observatory (CTIO), Chile. Repeated DECam images of a field centered on M5 (R.A.=15:18:33.2, decl.=+02:04:51.7, J2000.0) were obtained using the u,g,r,i, and z filters. The large field of view (FOV) of DECam (2.2°) easily covers the whole globular cluster with only the central CCDs of the camera. A total of 66 RR Lyrae stars and 1 SX Phe were recognized in the field of M5. The individual measurements for the periodic variable stars are provided in Table2. In Table3, we present the list of periodic variable stars. (3 data files).

Lithium abundances and metallicities in stars near the main-sequence turnoff and a giant in M67

International Nuclear Information System (INIS)

Garcia Lopez, R.J.; Rebolo, R.; Beckman, J.E.

1988-01-01

The iron abundance of seven stars near the main-sequence (MS) turnoff and a giant in M67 are spectroscopically derived, and the results are discussed. The resulting mean iron abundance of the turnoff stars is (Fe/H) = 0.04 + or - 0.04. Taken together with previous determinations for younger clusters, this shows that there has been relatively little change of the iron abundance in the solar neighborhood during the last 5 Gyr. Lithium was detected in one unevolved star and marginally in the giant, while in the other MS stars only upper limits were found. The considerable differences in Li abundances for stars with similar surface temperature imply that there is at least one parameter affecting Li depletion apart from stellar mass and metallicity. Nonsimultaneous star formation in the cluster cloud explain the scatter in lithium abundances. 50 references

GAS, STARS, AND STAR FORMATION IN ALFALFA DWARF GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Huang Shan; Haynes, Martha P.; Giovanelli, Riccardo [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Brinchmann, Jarle [Sterrewacht Leiden, Leiden University, NL-2300 RA Leiden (Netherlands); Stierwalt, Sabrina [Spitzer Science Center, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Neff, Susan G., E-mail: shan@astro.cornell.edu, E-mail: haynes@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: jarle@strw.leidenuniv.nl, E-mail: sabrina@ipac.caltech.edu, E-mail: susan.g.neff@nasa.gov [NASA GSFC, Code 665, Observational Cosmology Lab, Greenbelt, MD 20771 (United States)

2012-06-15

We examine the global properties of the stellar and H I components of 229 low H I mass dwarf galaxies extracted from the ALFALFA survey, including a complete sample of 176 galaxies with H I masses <10{sup 7.7} M{sub Sun} and H I line widths <80 km s{sup -1}. Sloan Digital Sky Survey (SDSS) data are combined with photometric properties derived from Galaxy Evolution Explorer to derive stellar masses (M{sub *}) and star formation rates (SFRs) by fitting their UV-optical spectral energy distributions (SEDs). In optical images, many of the ALFALFA dwarfs are faint and of low surface brightness; only 56% of those within the SDSS footprint have a counterpart in the SDSS spectroscopic survey. A large fraction of the dwarfs have high specific star formation rates (SSFRs), and estimates of their SFRs and M{sub *} obtained by SED fitting are systematically smaller than ones derived via standard formulae assuming a constant SFR. The increased dispersion of the SSFR distribution at M{sub *} {approx}< 10{sup 8} M{sub Sun} is driven by a set of dwarf galaxies that have low gas fractions and SSFRs; some of these are dE/dSphs in the Virgo Cluster. The imposition of an upper H I mass limit yields the selection of a sample with lower gas fractions for their M{sub *} than found for the overall ALFALFA population. Many of the ALFALFA dwarfs, particularly the Virgo members, have H I depletion timescales shorter than a Hubble time. An examination of the dwarf galaxies within the full ALFALFA population in the context of global star formation (SF) laws is consistent with the general assumptions that gas-rich galaxies have lower SF efficiencies than do optically selected populations and that H I disks are more extended than stellar ones.

GAS, STARS, AND STAR FORMATION IN ALFALFA DWARF GALAXIES

International Nuclear Information System (INIS)

Huang Shan; Haynes, Martha P.; Giovanelli, Riccardo; Brinchmann, Jarle; Stierwalt, Sabrina; Neff, Susan G.

2012-01-01

We examine the global properties of the stellar and H I components of 229 low H I mass dwarf galaxies extracted from the ALFALFA survey, including a complete sample of 176 galaxies with H I masses 7.7 M ☉ and H I line widths –1 . Sloan Digital Sky Survey (SDSS) data are combined with photometric properties derived from Galaxy Evolution Explorer to derive stellar masses (M * ) and star formation rates (SFRs) by fitting their UV-optical spectral energy distributions (SEDs). In optical images, many of the ALFALFA dwarfs are faint and of low surface brightness; only 56% of those within the SDSS footprint have a counterpart in the SDSS spectroscopic survey. A large fraction of the dwarfs have high specific star formation rates (SSFRs), and estimates of their SFRs and M * obtained by SED fitting are systematically smaller than ones derived via standard formulae assuming a constant SFR. The increased dispersion of the SSFR distribution at M * ∼ 8 M ☉ is driven by a set of dwarf galaxies that have low gas fractions and SSFRs; some of these are dE/dSphs in the Virgo Cluster. The imposition of an upper H I mass limit yields the selection of a sample with lower gas fractions for their M * than found for the overall ALFALFA population. Many of the ALFALFA dwarfs, particularly the Virgo members, have H I depletion timescales shorter than a Hubble time. An examination of the dwarf galaxies within the full ALFALFA population in the context of global star formation (SF) laws is consistent with the general assumptions that gas-rich galaxies have lower SF efficiencies than do optically selected populations and that H I disks are more extended than stellar ones.

Living with a Red Dwarf: A Chandra Archival Study of dM Star Activity and Habitability

Science.gov (United States)

Engle, Scott

2017-09-01

We propose to analyze 6 archival Chandra visits, not pointed at, but serendipitously including 3 dM stars of known age. GJ 669 AB are a common proper motion pair, each are resolved and detected in 3 exposures, and LHS 373 is a much older dM star also detected on 3 exposures. Photometry (by us) of GJ 669 AB began 5 years ago, is ongoing, and has precisely determined rotation rates for both stars and evidence of frequent flaring from GJ 669 B. We will analyze the multiple exposures, derive an accurate mean level of X-ray activity from the targets, and also separate out and individually analyze and model any observed X-ray flares. This proposal will provide highly accurate coronal properties for the targets, but also very useful data for stellar evolution and planetary habitability studies.

ISPARTA İLİ ELELE DERNEĞİ KÜLTÜR EVİNDEKİ EL ÖRGÜSÜ PATİKLER VE ÇORAPLAR

Directory of Open Access Journals (Sweden)

Gulfizar Cayli

2016-10-01

Full Text Available El sanatları, insanoğlunun var oluşundan bu yana gelenek göreneklerinin yanı sıra duygu, düşünce ve yaşadığı yörenin özelliklerini yansıtan, tarihten günümüze taşıdığı en önemli kültür hazinelerinden birisidir. Ayrıca insanların süslenme, iklim ve diğer dış etkenlere karşı korunma gibi ihtiyaçlardan doğan eski bir sanat dalıdır. Bu nedenle de Anadolu’nun pek çok yöresinde, geleneksel el sanatları içerisinde yer alan örmeciliğin bir dalı olan el örücülüğünü rastlamak mümkündür. Günümüzde çorap ve patik örücülüğü makineleşmenin başlamasıyla azalmasına rağmen, Isparta yöresinde kadınlar boş zamanlarını değerlendirmek, iklim şartlarından korunmak, aile ekonomisini katkıda bulunmak ve kız çeyizini sağlamak amacıyla hala devam ettirilmektedir. Bu çalışmada; Isparta İli Elele Derneği Kültür Evinde bulunan 12 adet kadın patiği, 8 adet kadın çorabı, 2 adet erkek çorabı ve 1 adet çocuk çorabı ele alınmıştır. Örgü teknikleri, kullanılan araç–gereçler, renk, motif ve desen özellikleri incelenerek, fotoğraflarla gösterilmiştir. Bu çorap ve patiklerimizi literatüre kazandırmak, sahip çıkmak ve belgelendirmek amaçlanmıştır.

The vast population of Wolf-Rayet and red supergiant stars in M101. I. Motivation and first results

Energy Technology Data Exchange (ETDEWEB)

Shara, Michael M.; Bibby, Joanne L.; Zurek, David [Department of Astrophysics, American Museum of Natural History, Central Park West and 79th Street, New York, NY 10024-5192 (United States); Crowther, Paul A. [Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Moffat, Anthony F. J. [Département de Physique, Université de Montréal, CP 6128 Succ. C-V, Montréal, QC H3C 3J7 (Canada); Drissen, Laurent [Département de Physique, Université Laval, Pavillon Vachon, Quebec City, QC G1K 7P4 (Canada)

2013-12-01

Assembling a catalog of at least 10,000 Wolf-Rayet (W-R) stars is an essential step in proving (or disproving) that these stars are the progenitors of Type Ib and Type Ic supernovae. To this end, we have used the Hubble Space Telescope (HST) to carry out a deep, He II optical narrowband imaging survey of the ScI spiral galaxy M101. Almost the entire galaxy was imaged with the unprecedented depth and resolution that only the HST affords. Differenced with archival broadband images, the narrowband images allow us to detect much of the W-R star population of M101. We describe the extent of the survey and our images, as well as our data reduction procedures. A detailed broadband-narrowband imaging study of a field east of the center of M101, containing the giant star-forming region NGC 5462, demonstrates our completeness limits, how we find W-R candidates, their properties and spatial distribution, and how we rule out most contaminants. We use the broadband images to locate luminous red supergiant (RSG) candidates. The spatial distributions of the W-R and RSG stars near NGC 5462 are strikingly different. W-R stars dominate the complex core, while RSGs dominate the complex halo. Future papers in this series will describe and catalog more than a thousand W-R and RSG candidates that are detectable in our images, as well as spectra of many of those candidates.

Türev piyasaları ve vergilendirilmesi

OpenAIRE

İşler, İsmail; Utku, Mehmet

2015-01-01

Türev piyasaları kavramı, vadeli işlem sözleşmeleri (forward, futures), opsiyon sözleşmeleri, swap sözleşmeleri ve aracı kuruluş varantları işlemlerinin tamamını içermektedir. Bu tür işlemler vadeli işlemlerdir. Vadeli işlemlerin ortak özelliği, ilerideki bir tarihte teslimatı yapılmak üzere herhangi bir malın veya finansal aracın, bugünden alım satımının yapılmasıdır. Bu çalışmada türev araçların tanımları ve vergilendirilmeleri örneklerle açıklanacaktır. The term derivatives market invol...

Characterizing Wolf-Rayet stars in the near- and mid-infrared

Energy Technology Data Exchange (ETDEWEB)

Faherty, Jacqueline K. [Department of Terrestrial Magnetism, Carnegie Institution of Washington 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Shara, Michael M.; Zurek, David; Kanarek, Graham [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Moffat, Anthony F. J., E-mail: jfaherty@dtm.ciw.edu [Departement de Physique, Universite de Montreal, C.P. 6128, Succursale Centre-Ville, Montreal, QC H3C 3J7 (Canada)

2014-05-01

We present refined color-color selection criteria for identifying Wolf-Rayet (WR) stars using available mid-infrared (MIR) photometry from WISE in combination with near-infrared (NIR) photometry from the Two Micron All Sky Survey. Using a sample of spectrally classified objects, we find that WR stars are well distinguished from the field stellar population in the (W1 – W2) versus (J – K{sub s} ) color-color diagram, and further distinguished from other emission line objects such as planetary nebulae, Be, and cataclysmic variable stars using a combination of NIR and MIR color constraints. As proof of concept we applied the color constraints to a photometric sample in the Galactic plane, located WR star candidates, and present five new spectrally confirmed and classified WC (1) and WN (4) stars. Analysis of the 0.8-5.0 μm spectral data for a subset of known, bright WC and WN stars shows that emission lines (primarily He I) extend into the 3.0-5.0 μm spectral region, although their strength is greatly diminished compared to the 0.8-2.5 μm region. The WR population stands out relative to background field stars at NIR and MIR colors due to an excess continuum contribution, likely caused by free-free scattering in dense winds. Mean photometric properties of known WRs are presented and imply that reddened late-type WN and WC sources are easier to detect than earlier-type sources at larger Galactic radii. WISE W3 and W4 images of 10 WR stars show evidence of circumstellar shells linked to mass ejections from strong stellar winds.

Větrné podmínky v České republice ve výšce 10 m nad povrchem II

Czech Academy of Sciences Publication Activity Database

Hanslian, David; Hošek, Jiří; Chládová, Zuzana; Pop, Lukáš

2013-01-01

Roč. 2013, 22. 4. 2013 (2013), s. 1-5 ISSN 1801-4399 Institutional support: RVO:68378289 Keywords : distribution of wind speed * prevailing wind direction * wind map Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use http:// oze .tzb-info.cz/vetrna-energie/9800-vetrne-podminky-v-ceske-republice-ve-vysce-10-m-nad-povrchem-ii

Větrné podmínky v České republice ve výšce 10 m nad povrchem I

Czech Academy of Sciences Publication Activity Database

Hanslian, David; Hošek, Jiří; Chládová, Zuzana; Pop, Lukáš

2013-01-01

Roč. 2013, 15.4.2013 (2013), s. 1-5 ISSN 1801-4399 Institutional support: RVO:68378289 Keywords : Wind map * WAsP model * Czech Republic * PIAP model * VAS method Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use http://oze.tzb-info.cz/vetrna-energie/9770-vetrne-podminky-v-ceske-republice-ve-vysce-10-m-nad-povrchem-i

The CARMENES search for exoplanets around M dwarfs. High-resolution optical and near-infrared spectroscopy of 324 survey stars

Science.gov (United States)

Reiners, A.; Zechmeister, M.; Caballero, J. A.; Ribas, I.; Morales, J. C.; Jeffers, S. V.; Schöfer, P.; Tal-Or, L.; Quirrenbach, A.; Amado, P. J.; Kaminski, A.; Seifert, W.; Abril, M.; Aceituno, J.; Alonso-Floriano, F. J.; Ammler-von Eiff, M.; Antona, R.; Anglada-Escudé, G.; Anwand-Heerwart, H.; Arroyo-Torres, B.; Azzaro, M.; Baroch, D.; Barrado, D.; Bauer, F. F.; Becerril, S.; Béjar, V. J. S.; Benítez, D.; Berdinas˜, Z. M.; Bergond, G.; Blümcke, M.; Brinkmöller, M.; del Burgo, C.; Cano, J.; Cárdenas Vázquez, M. C.; Casal, E.; Cifuentes, C.; Claret, A.; Colomé, J.; Cortés-Contreras, M.; Czesla, S.; Díez-Alonso, E.; Dreizler, S.; Feiz, C.; Fernández, M.; Ferro, I. M.; Fuhrmeister, B.; Galadí-Enríquez, D.; Garcia-Piquer, A.; García Vargas, M. L.; Gesa, L.; Galera, V. Gómez; González Hernández, J. I.; González-Peinado, R.; Grözinger, U.; Grohnert, S.; Guàrdia, J.; Guenther, E. W.; Guijarro, A.; Guindos, E. de; Gutiérrez-Soto, J.; Hagen, H.-J.; Hatzes, A. P.; Hauschildt, P. H.; Hedrosa, R. P.; Helmling, J.; Henning, Th.; Hermelo, I.; Hernández Arabí, R.; Hernández Castaño, L.; Hernández Hernando, F.; Herrero, E.; Huber, A.; Huke, P.; Johnson, E. N.; Juan, E. de; Kim, M.; Klein, R.; Klüter, J.; Klutsch, A.; Kürster, M.; Lafarga, M.; Lamert, A.; Lampón, M.; Lara, L. M.; Laun, W.; Lemke, U.; Lenzen, R.; Launhardt, R.; López del Fresno, M.; López-González, J.; López-Puertas, M.; López Salas, J. F.; López-Santiago, J.; Luque, R.; Magán Madinabeitia, H.; Mall, U.; Mancini, L.; Mandel, H.; Marfil, E.; Marín Molina, J. A.; Maroto Fernández, D.; Martín, E. L.; Martín-Ruiz, S.; Marvin, C. J.; Mathar, R. J.; Mirabet, E.; Montes, D.; Moreno-Raya, M. E.; Moya, A.; Mundt, R.; Nagel, E.; Naranjo, V.; Nortmann, L.; Nowak, G.; Ofir, A.; Oreiro, R.; Pallé, E.; Panduro, J.; Pascual, J.; Passegger, V. M.; Pavlov, A.; Pedraz, S.; Pérez-Calpena, A.; Medialdea, D. Pérez; Perger, M.; Perryman, M. A. C.; Pluto, M.; Rabaza, O.; Ramón, A.; Rebolo, R.; Redondo, P.; Reffert, S.; Reinhart, S.; Rhode, P.; Rix, H.-W.; Rodler, F.; Rodríguez, E.; Rodríguez-López, C.; Rodríguez Trinidad, A.; Rohloff, R.-R.; Rosich, A.; Sadegi, S.; Sánchez-Blanco, E.; Sánchez Carrasco, M. A.; Sánchez-López, A.; Sanz-Forcada, J.; Sarkis, P.; Sarmiento, L. F.; Schäfer, S.; Schmitt, J. H. M. M.; Schiller, J.; Schweitzer, A.; Solano, E.; Stahl, O.; Strachan, J. B. P.; Stürmer, J.; Suárez, J. C.; Tabernero, H. M.; Tala, M.; Trifonov, T.; Tulloch, S. M.; Ulbrich, R. G.; Veredas, G.; Vico Linares, J. I.; Vilardell, F.; Wagner, K.; Winkler, J.; Wolthoff, V.; Xu, W.; Yan, F.; Zapatero Osorio, M. R.

2018-04-01

The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520-1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700-900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s-1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3-4 m s-1.

Domates Salçalarının Mikroflorası ve Depolama Sürecinde Miktarlarındaki Değişiklikler

Directory of Open Access Journals (Sweden)

Fikri Başoğlu

2015-02-01

Full Text Available - Ticari sterilize edilen domates salçasının muhafazası esnasında sterilliği azalmaktadır. 12 aylık muhafaza süresinde sterillik %100’den %15 ve 8’e hatta daha aza düşebilir. - Pastörizasyonda tatbik edilen sıcaklık derecesi (89-93 oC laktik asit bakterileri ile maya ve küflerin yaşamasına imkan vermemektedir. - Domates salçasının kalıntı mikroflorasını umumiyetle spor yapan bakteriler (B. subtilis, B. mesentericus, B. cereus ..... temsil etmektedir. - Domates salçasının kuru maddesi %28-30 veya %38-40 olması B. subtilis ve B. mesentericus’un ölmesine tesir etmemektedir. - Salçanın 10-15 oC ta muhafaza edilmesi termofil mikroorganizmaların çoğalmasına engel olmaktadır. - Salçanın pH’sı yükseltilirse sporlar çabuk gelişmektedir. - Hermetikli kapatmadaki hatalarda laktik asit bakterileri ve mayalar salçayı bozmaktadırlar. - Salçada bulunan bazı sporlu ve sporsuz mikroorganizmaların termal ölüm müddetlerine ortamın pH’sı, organik asitler ve spor konsantrasyonu etki etmektedir.