Orbits of Six Late-type Active-Chromosphere Binaries

We present spectroscopic orbits for the active stars HD 82159 (GS Leo), HD 89959, BD +39 2587 (a visual companion to HD 112733), HD 138157 (OX Ser), HD 143705, and HD 160934. This paper is a sequel to one published in this journal in 2006, with similar avowed intention, by Galvez et al.. They showed only graphs, and gave no data, and no orbital elements apart from the periods (only two of which were correct) and in some cases the eccentricities. Here we provide full information and reliable orbital elements for all the stars apart from HD 160934, which has not completed a cycle since it was first observed for radial velocity.Comment: 17 pages, 8 figures. Accepted for publication in Astrophysics & Space Scienc

Doğrusal proğramlama metodu ile üretim planlaması: Isparta Mensucat A.Ş.'nde uygulama

Bu tez çalışmasında, doğrusal programlama tekniği kullanılarak üretim planlaması yapılmıştır. Uygulama yeri, Isparta Mensucat İplik Fabrikası Boyahanesi'dir. Araştırma üç bölümden oluşmaktadır. Birinci bölümde; üretim planlamasının tanımı, amacı, önemi, yararları, hazırlanması ve çeşitleri gibi konularla, üretim planlamasının matematiksel yöntemleri incelenmiştir. Bunun yanında, doğrusal programlamanın tanımı, uygulama alanları, genel bir doğrusal programlama modelinin matematiksel ifadesi ile çözüm tekniklerinden, simpleks metodu ve tamsayılı programlama konularına değinilmiştir. İkinci bölümde; iplik fabrikalarında iplik boyama işleminin nasıl yapıldığı anlatılarak iki ayrı model önerisinde bulunulmuştur. Üçüncü bölümde ise; uygulama yeri olan, Isparta Mensucat İplik Fabrikası Boyahanesi'nde önerilen iki model uygulanmış, değerlendirilmesi yapılmıştır.\ud In this thesis working, production planning had been done by using linear programming technique. Application place is, the dye house of Isparta Mensucat Ring Factory. This research contains three chapters. In the first chapter, not only the explanation of production planning, its aim, importance, maintenance, preparation and types of production planning but also mathematical methods of production planning had been researched. In addition, the subjects such as the explanation of linear programming, its uses and application areas, mathematical expression of a general linear programming model; also the solution technique simplex method and integer number programming had been researched. In the second chapter; by explaining how can the dying process done in the ring factories the two different kinds of model had been offered. Finally, in the third chapter; the two kinds of models had been applied at the dye house of Isparta Mensucat Ring Factory and their utilizations had been done

Do the effects of vitamin d supplementation on muscle strength differ according to age?

Introduction: Vitamin D plays an important role in musculoskeletal health and its use improves muscle strength. However, the effect of vitamin D use on muscle strength in women of different ages is yet to be investigated. Therefore, in this study, we aimed to evaluate the effect of vitamin D use on muscle strength in women of different age groups and determine the differences of muscle strength gain between age groups. Materials and Method: Sixty-three women with calcidiol levels<30 ng/mL were randomly assigned and stratified by their age group as follows: Group I (aged 40–49 years), Group II (aged 50–59 years) and Group III (aged 60–69 years). Calcidiol levels, body mass index, fat free mass, percent fat, grip strength, arm curl, chair stand and isokinetic concentric flexor and extensor peak torque and power at 60°•s−1 and 180°•s−1 were assessed at baseline and six months after oral cholecalciferol supplementation. Results: Vitamin D supplementation caused significant improvement in body mass index, arm curl, grip strength and knee flexor and extensor peak torque and power at 60°•s−1 and 180°•s−1 in all groups (p<0.05). Knee flexor power at 60°•s−1 and extensor power at 180°•s−1 were significantly higher in group I than in group III (p<0.025). Conclusion: Muscle strength in response to vitamin D supplementation increased in all age groups, and isokinetic muscle power was the highest in the youngest age group studied. © 2018, Geriatrics Society. All rights reserved

C IV BAL disappearance in a large SDSS QSO sample

Broad absorption lines (BALs) in the spectra of quasi-stellar objects (QSOs) originate from outflowing winds along our line of sight; winds are thought to originate from the inner regions of the QSO accretion disk, close to the central supermassive black hole (SMBH). Winds likely play a role in galaxy evolution and aid the accretion mechanism onto the SMBH. BAL equivalent widths can change on typical timescales from months to years; such variability is generally attributed to changes in the covering factor and/or in the ionization level of the gas. We investigate BAL variability, focusing on BAL disappearance. We analyze multi-epoch spectra of more than 1500 QSOs -the largest sample ever used for such a study- observed by different programs from the Sloan Digital Sky Survey-I/II/III (SDSS), and search for disappearing C IV BALs. The spectra rest-frame time baseline ranges from 0.28 to 4.9 yr; the source redshifts range from 1.68 to 4.27. We detect 73 disappearing BALs in the spectra of 67 sources. This corresponds to 3.9% of disappearing BALs, and 5.1% of our BAL QSOs exhibit at least one disappearing BAL. We estimate the average lifetime of a BAL along our line of sight (~ 80-100 yr), which appears consistent with the accretion disk orbital time at distances where winds are thought to originate. We inspect properties of the disappearing BALs and compare them to the properties of our main sample. We also investigate the existence of a correlation in the variability of multiple troughs in the same spectrum, and find it persistent at large velocity offsets between BAL pairs, suggesting that a mechanism extending on a global scale is necessary to explain the phenomenon. We select a more reliable sample of disappearing BALs following Filiz Ak et al. (2012), where a subset of our sample was analyzed, and compare the findings from the two works, obtaining generally consistent results.Comment: 22 pages, 9 figures. Accepted for publication in A&

X-ray Insights into the Nature of Quasars with Redshifted Broad Absorption Lines

We present $Chandra$ observations of seven broad absorption line (BAL) quasars at $z=0.863$-2.516 with redshifted BAL troughs (RSBALs). Five of our seven targets were detected by $Chandra$ in 4-13 ks exposures with ACIS-S. The $\alpha_{\rm ox}$ values, $\Delta\alpha_{\rm ox}$ values, and spectral energy distributions of our targets demonstrate they are all X-ray weak relative to expectations for non-BAL quasars, and the degree of X-ray weakness is consistent with that of appropriately-matched BAL quasars generally. Furthermore, our five detected targets show evidence for hard X-ray spectral shapes with a stacked effective power-law photon index of $\Gamma_{\rm eff}=0.5^{+0.5}_{-0.4}$. These findings support the presence of heavy X-ray absorption ($N_{\rm H}\approx 2 \times 10^{23}$ cm$^{-2}$) in RSBAL quasars, likely by the shielding gas found to be common in BAL quasars more generally. We use these X-ray measurements to assess models for the nature of RSBAL quasars, finding that a rotationally-dominated outflow model is favored while an infall model also remains plausible with some stipulations. The X-ray data disfavor a binary quasar model for RSBAL quasars in general.Comment: 11 pages, 5 figures, and 3 table

X-ray and multi-epoch optical/UV investigations of BAL to non-BAL quasar transformations

We report on an X-ray and optical/UV study of eight Broad Absorption Line (BAL) to non-BAL transforming quasars at $z\,\approx\,$1.7-2.2 over 0.29-4.95 rest-frame years with at least three spectroscopic epochs for each quasar from the SDSS, BOSS, $Gemini$, and ARC 3.5-m telescopes. New $Chandra$ observations obtained for these objects show their values of $\alpha_{\rm ox}$ and $\Delta{\alpha}_{\rm ox}$, as well as their spectral energy distributions, are consistent with those of non-BAL quasars. Moreover, our targets have X-ray spectral shapes that are, on average, consistent with weakened absorption with an effective power-law photon index of $\Gamma_{\rm eff}\,=\,1.69^{+0.25}_{-0.25}$. The newer $Gemini$ and ARC 3.5-m spectra reveal that the BAL troughs have remained absent since the BOSS observations where the BAL disappearance was discovered. The X-ray and optical/UV results in tandem are consistent with at least the X-ray absorbing material moving out of the line-of-sight, leaving an X-ray unabsorbed non-BAL quasar. The UV absorber might have become more highly ionized (in a shielding-gas scenario) or also moved out of the line-of-sight (in a wind-clumping scenario).Comment: 14 pages, 5 figures, Accepted for publication in MNRA

Variability of Low-ionization Broad Absorption Line Quasars Based on Multi-epoch Spectra from The Sloan Digital Sky Survey

We present absorption variability results for 134 bona fide \mgii\ broad absorption line (BAL) quasars at 0.46~$\lesssim z \lesssim$~2.3 covering days to $\sim$ 10 yr in the rest frame. We use multiple-epoch spectra from the Sloan Digital Sky Survey, which has delivered the largest such BAL-variability sample ever studied. \mgii-BAL identifications and related measurements are compiled and presented in a catalog. We find a remarkable time-dependent asymmetry in EW variation from the sample, such that weakening troughs outnumber strengthening troughs, the first report of such a phenomenon in BAL variability. Our investigations of the sample further reveal that (i) the frequency of BAL variability is significantly lower (typically by a factor of 2) than that from high-ionization BALQSO samples; (ii) \mgii\ BAL absorbers tend to have relatively high optical depths and small covering factors along our line of sight; (iii) there is no significant EW-variability correlation between \mgii\ troughs at different velocities in the same quasar; and (iv) the EW-variability correlation between \mgii\ and \aliii\ BALs is significantly stronger than that between \mgii\ and \civ\ BALs at the same velocities. These observational results can be explained by a combined transverse-motion/ionization-change scenario, where transverse motions likely dominate the strengthening BALs while ionization changes and/or other mechanisms dominate the weakening BALs.Comment: 24 pages, accepted for publication in ApJ

The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability

We report the discovery of rapid variations of a high-velocity CIV broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4sigma) variability in the equivalent width of the broad (~4000 km/s wide) CIV trough on rest-frame timescales as short as 1.20 days (~29 hours), the shortest broad absorption line variability timescale yet reported. The equivalent width varied by ~10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of n_e > 3.9 x 10^5 cm^-3. The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.Comment: 15 pages, 14 figures. Accepted for publication in the Astrophysical Journa

Design of a five-axis ultra-precision micro-milling machine—UltraMill. Part 1: Holistic design approach, design considerations and specifications

High-accuracy three-dimensional miniature components and microstructures are increasingly in demand in the sector of electro-optics, automotive, biotechnology, aerospace and information-technology industries. A rational approach to mechanical micro machining is to develop ultra-precision machines with small footprints. In part 1 of this two-part paper, the-state-of-the-art of ultra-precision machines with micro-machining capability is critically reviewed. The design considerations and specifications of a five-axis ultra-precision micro-milling machine—UltraMill—are discussed. Three prioritised design issues: motion accuracy, dynamic stiffness and thermal stability, formulate the holistic design approach for UltraMill. This approach has been applied to the development of key machine components and their integration so as to achieve high accuracy and nanometer surface finish

The Baryon Oscillation Spectroscopic Survey of SDSS-III

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A