Yield and fiber quality properties of cotton (Gossypium hirsutum L.) under water stress and non-stress conditions

The primary objective of this study was to determine the effect of water stress and non-stress conditions on cotton yield and fiber quality properties. A two-year field study was carried out at the Southeastern Anatolia Agricultural Research Institute (SAARI), in 2009 and 2010, with the aim of evaluating 12 cotton genotypes for yield and fiber quality properties under irrigated and water stress conditions. The experiment was laid out as a randomized split block design (RSBD) with four replications. Significant differences were observed among genotypes and water treatments for seed cotton yield, fiber yield, ginning percentage and all fiber quality properties except fiber uniformity. Yield differences among genotypes under water stress and non-stress conditions were higher during the first season. In both years, SER-18 and Stoneville 468 cotton genotypes produced higher yield under water stress conditions, while Stoneville 468 produced higher yield under well-irrigated conditions. The results during the two years indicated that seed cotton yield decreased (48.04%) and fiber yield decreased (49.41%), due to water stress. Ginning percentage and fiber quality properties were also negatively affected by water stress treatment. Fiber length, fiber strength, fiber fineness and fiber elongation were decreased, while fiber uniformity was not affected by water stress treatment.Key words: Cotton, yield, fiber quality properties, water stress, non-stress

Monocrystalline silicon carbide nanoelectromechanical systems

SiC is an extremely promising material for nanoelectromechanical systems given its large Young's modulus and robust surface properties. We have patterned nanometer scale electromechanical resonators from single-crystal 3C-SiC layers grown epitaxially upon Si substrates. A surface nanomachining process is described that involves electron beam lithography followed by dry anisotropic and selective electron cyclotron resonance plasma etching steps. Measurements on a representative family of the resulting devices demonstrate that, for a given geometry, nanometer-scale SiC resonators are capable of yielding substantially higher frequencies than GaAs and Si resonators

Türkiye’de Yükseköğretimde Öğrenci Harcama ve Maliyetleri

The purpose of this study is to determine individual (private), public and total unit costs of higher education and their components within three universities in Turkey. The sample of the study has consisted of 3330 first grade undergraduate students of Hacettepe, Cumhuriyet and Erciyes universities in 2007-2008 academic year. The data related to individual expenditures of the students were obtained through the administration of the questionnaire to the students in the sample. The data related to public expenditures and foregone earnings and taxes were obtained from official records. The study revealed that almost all students within the scope of the study have spent a significant amount of money (4.475 TL) for the purpose of university entrance preparations compared to the incomes of the households, and in general, the share of the private cost (8.692 TL) is greater than the share of the public cost (6.647 TL) in annual unit cost (15.339 TL).Bu çalışmanın amacı, Türkiye’deki üç üniversitede bireysel, kamusal ve toplam birim öğrenci maliyetlerini belirlemek ve bu maliyetleri oluşturan bileşenleri ortaya koymaktır. Araştırmanın örneklemini 2007-2008 öğretim yılında Hacettepe, Cumhuriyet ve Erciyes üniversitelerinde öğrenim gören 3330 birinci sınıf öğrencisi oluşturmaktadır. Araştırmanın bireysel harcamalara ilişkin verileri, araştırmacı tarafından geliştirilen anketin örnekleme uygulanması ile elde edilmiştir. Kamusal harcamalara ve vazgeçilen maliyetlere ilişkin veriler yasal ve yönetsel kayıtlardan elde edilmiştir. Araştırma ile (1) araştırma kapsamındaki öğrencilerin neredeyse tamamının üniversiteye hazırlık harcaması yaptığı ve bu harcamaların hanehalkı gelirleriyle karşılaştırıldığında önemli miktarlara (4.475 TL) ulaştığı ve (2) toplam birim öğrenci maliyeti (15.339 TL) içinde, genel olarak bireysel öğrenci maliyetinin (8.692 TL) payının kamusal öğrenci maliyetinden (6.647 TL) daha yüksek olduğu belirlenmiştir

Bazı Sosyoekonomik Etmenlerin Türkiye’de Yükseköğretime Katılım Üzerindeki Etkileri

The purpose of this study is to determine the impact of some socio-economic factors (household income, parents’ education, and parents’ residential status such that of urban or rural) on higher education participation through the comparison of the socio-economic status of the students with the same status of the related population in Turkey. The data of the study were obtained through the administration of a questionnaire to 4910 first year university-level students at Cumhuriyet, Erciyes and Hacettepe universities and a thorough literature review. General results of the study are as follows: (1) Distribution of household income of Turkey and students’ annual disposable income by quintiles are similar and household income is not a direct factor on higher education participation. (2) Educational status of parents is a determining factor in higher education participation. (3) Students whose parents are graduates of higher levels of education and income are over-represented in the programs that are assumed to be prestigious and high income generating. (4) Higher education institutions serve to students coming from urban areas to a great extent (92%).Bu çalışmanın amacı, yükseköğretimden yararlanan öğrencilerin bazı sosyoekonomik özelliklerinin (hanehalkı geliri, anne-babanın eğitim durumu, yerleşim yeri) dağılımı ile Türkiye’deki nüfusun aynı özelliklerinin dağılımının karşılaştırılması yoluyla bu etmenlerin yükseköğretimden yararlanma üzerindeki etkilerini belirlemektir. Araştırmanın verileri Cumhuriyet, Erciyes ve Hacettepe üniversitelerinde öğrenim gören 4910 öğrenciye uygulanan anket ve alanyazın taramasına dayalı olarak elde edilmiştir.Araştırma betimsel bir çalışmadır. Bu çalışmada şu sonuçlara ulaşılmıştır: (1) Gelire göre sıralı %20’lik Türkiye ve üniversite öğrencileri hanehalkı gruplarının yıllık kullanılabilir gelirlerinin yüzdelik dağılımları birbirine benzerdir ve yükseköğretime girişte gelir doğrudan belirleyici etkiye sahip değildir. (2) Yükseköğretimden yararlanmada anne-babanın eğitim düzeyi belirleyici bir etkendir. (3) Daha yüksek gelirli ve eğitimli ailelerin çocukları daha prestijli ve daha yüksek getirisi olduğu varsayılan alanlarda daha yüksek oranda temsil edilmektedirler. (4) Yükseköğretim sistemi çok büyük ölçüde kentsel yerleşim birimlerinden gelen öğrencilere (%92) hizmet etmektedir

Radio-frequency scanning tunnelling microscopy

The scanning tunnelling microscope (STM) relies on localized electron tunnelling between a sharp probe tip and a conducting sample to attain atomic-scale spatial resolution. In the 25-year period since its invention, the STM has helped uncover a wealth of phenomena in diverse physical systems -— ranging from semiconductors to superconductors to atomic and molecular nanosystems. A severe limitation in scanning tunnelling microscopy is the low temporal resolution, originating from the diminished high-frequency response of the tunnel current readout circuitry. Here we overcome this limitation by measuring the reflection from a resonant inductor–capacitor circuit in which the tunnel junction is embedded, and demonstrate electronic bandwidths as high as 10 MHz. This ~100-fold bandwidth improvement on the state of the art translates into fast surface topography as well as delicate measurements in mesoscopic electronics and mechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM have allowed us to perform thermometry at the nanometre scale. Furthermore, we have detected high-frequency mechanical motion with a sensitivity approaching ~15 fm Hz^(-1/2). This sensitivity is on par with the highest available from nanoscale optical and electrical displacement detection techniques, and the radio-frequency STM is expected to be capable of quantum-limited position measurements

Organizational silence behaviors of faculty members, their causes and consequencesÖğretim elemanlarında örgütsel sessizlik davranışı, nedenleri ve sonuçları

Purpose: The purpose of this study is to investigate faculty members’ organizational silence behaviors, the effects of reasons leading to silence, the consequences of silence behaviors and their relationships with some variables of gender and academic titles. Method: The study was conducted as a quantitative descriptive research. The sample of the study is comprised of 554 faculty members. The data of the study were collected through the administration of three questionnaires developed by the researchers to the sample group. In data analysis, descriptive statistics, t-test for independent groups, one-way variance analysis (ANOVA) were employed. Results: The major results of the study are: (1) The faculty members exhibit the silence behavior in three problem areas to a great extent (non-ethical behaviors and practices, administrative functioning and practices and academic structure and functioning) (2) Both the individual factors and factors related to administrative practices are effective over a moderate level in the faculty members’ exhibiting the silence behavior. (3) The faculty members are of the opinions that their organizational silence behaviors result in problems that can considerably affect individual and organizational efficiency. (4) Among all staff, the research assistants show the most silence behavior and observe the consequences of the silence behavior the most. In short, organizational silence is an important managerial proble.Extended English summary is in the end of Full Text PDF (TURKISH) file. ÖzetAmaç: Bu çalışmanın amacı öğretim elemanlarının örgütsel sessizlik davranışına yol açan sorunları, nedenlerini ve sonuçlarını belirlemek ve cinsiyet ve akademik unvan değişkenleri ile ilişkisini incelemektir. Yöntem: Tarama modelinde betimsel bir çalışma olan araştırmanın örneklemini 554 öğretim elemanı oluşturmaktadır. Araştırmanın verileri araştırmacılar tarafından geliştirilen üç ölçeğin örnekleme uygulanmasıyla elde edilmiştir. Araştırma verilerinin çözümlenmesinde betimsel istatistikler, karşılaştırmalarda t-testi ve varyans analizi (ANOVA) kullanılmıştır. Sonuçlar: Araştırmada şu temel sonuçlara ulaşılmıştır: (1) Öğretim elemanları üç sorun alanında (etik olamayan davranış ve uygulamalar, yönetsel işleyiş ve uygulamalar, akademik yapı ve işleyiş) önemli ölçüde sessizlik davranışı göstermektedirler. (2) Öğretim elemanlarının sessizlik davranışı göstermelerinde hem bireysel etmenler hem de yönetsel uygulamalarla ilgili etmenler orta düzeyin üstünde etkili olmaktadır. (3) Öğretim elemanları örgütsel sessizlik davranışlarının bireysel ve kurumsal etkililiği etkileyebilecek sorunlara yol açtığı düşüncesine oldukça yüksek düzeyde sahiptirler. (3) Araştırma görevlileri en fazla sessizlik gösteren ve sonuçlarından en fazla etkilenen akademik unvan grubu olarak görünmektedir. Kısaca örgütsel sessizlik üniversiteler için üstesinden gelmek için çaba gösterilmesi gereken önemli bir yönetsel sorun alandır

Local differences of the position of the mental foramen

The mental foramen has been reported to vary in position in different ethnic groups. Repeated failures during injections and operative procedures involving the mental foramen suggest the presence of local differences in a given population. The aim of the present study was to investigate possible local differences of the mental foramen in Eastern Anatolian individuals in the Turkish population. The present investigation is based on the examination of 70 adult mandibles. The study consisted of three measurements, to include the relations of the mental foramen to the following: 1) the lower teeth; 2) the body of mandible; 3) the mandibular symphysis and posterior border of the ramus of the mandible. The most common position of the foramen was in line with the longitudinal axis of the second premolar tooth (relation IV), at the midpoint of the mandibular body height and at 1/3.5 of the distance from the mandibular symphysis to the posterior border of the ramus. Local differences of the mental foramen may occur in a population. Prior to surgery knowledge of the most common location of the foramen peculiar to a local population may enable effective mental block anaesthesia to be provided. (Folia Morphol 2008; 67: 32-35)

Tunneling through a multigrain system: deducing the sample topology from the nonlinear conductance

We study a current transport through a system of a few grains connected with tunneling links. The exact solution is given for an arbitrarily connected double-grain system with a shared gate in the framework of the orthodox model. The obtained result is generalized for multigrain systems with strongly different tunneling resistances. We analyse the large-scale nonlinear conductance and demonstrate how the sample topology can be unambiguously deduced from the spectroscopy pattern (differential conductance versus gate-bias plot). We present experimental data for a multigrain sample and reconstruct the sample topology. A simple selection rule is formulated to distinguish samples with spectral patterns free from spurious disturbance caused by recharging of some grains nearby. As an example, we demonstrate experimental data with additional peaks in the spectroscopy pattern, which can not be attributed to coupling to additional grains. The described approach can be used to judge the sample topology when it is not guaranteed by fabrication and direct imaging is not possible.Comment: 13 pages (including 8 figures

Discovery of Delta Scuti variables in eclipsing binary systems II.Southern TESS field search

The presence of pulsating stars in eclipsing binary systems (EBs) makes these objects significant since they allow us to investigate the stellar interior structure and evolution. Different types of pulsating stars could be found in EBs such as Delta Scuti variables. Delta Scuti stars in EBs have been known for decades and the increasing number of such systems is important for understanding pulsational structure. Hence, in this study, a research was carried out on the southern TESS field to discover new Delta Scuti stars in EBs. We produced an algorithm to search for detached and semi-detached EBs considering three steps; the orbital period (P$_{orb}$)'s harmonics in the Fourier spectrum, skewness of the light curves, and classification of \textsc{UPSILON} program. If two of these steps classify a system as an EB, the algorithm also identifies it as an EB. The TESS pixel files of targets were also analyzed to see whether the fluxes are contaminated by other systems. No contamination was found. We researched the existence of pulsation through EBs with a visual inspection. To confirm Delta Scuti-type oscillations, the binary variation was removed from the light curve, and residuals were analyzed. Consequently, we identified 42 Delta Scuti candidates in EBs. The P$_{orb}$, $L$, and M$_{V}$ of systems were calculated. Their positions on the H-R diagram and the known orbital-pulsation period relationship were analyzed. We also examined our targets to find if any of them show frequency modulation with the orbital period and discovered one candidate of tidally tilted pulsators.Comment: Published in MNRA

Infrared Studies of the Onset of Conductivity in Ultra-Thin Pb Films

In this paper we report the first experimental measurement of the infrared conductivity of ultra-thin quenched-condensed Pb films. For dc sheet resistances such that $\omega \tau \ll 1$ the ac conductance increases with frequency but is in disagreement with the predictions of weak localization. We attribute this behavior to the effects of an inhomogeneous granular structure of these films, which is manifested at the very small probing scale of infrared measurements. Our data are consistent with predictions of two-dimensional percolation theory.Comment: Submitted to Physical Review Letter