Characterization of GZO thin films fabricated by RF magnetron sputtering method and electrical properties of In/GZO/Si/Al diode

WOS: 000492443000014The main focus of this work is the structural and optical characterization of Ga-doped ZnO (GZO) thin film and determination of the device behavior of In/GZO/Si/Al diode. GZO thin films were deposited by RF magnetron sputtering technique from single target. The structural and morphological properties of GZO film were investigated by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) measurements. Optical properties of the film were determined with transmission measurement. Device characterization of In/GZO/Si/Al diode were done with the analysis of temperature dependent current voltage (I-V) measurement. The current conduction mechanism was investigated with the Thermionic Emission (TE) method. The deviation from the pure TE method was observed and this deviation was analyzed under the assumption of Gaussian Distribution (GD) of barrier height (TE emission with GD). The mean standard deviation and zero bias barrier height were calculated as 0.0268 (about %3) and 1.239 eV, respectively. Richardson constant was found to be as 115.42 A/cm(2) K-2 using the modified Richardson plot. In addition, series resistance R-s was obtained using Cheung's function. Finally, the interface state densities D-it were determined by using the forward bias I-V results

Turkish foreign policy in transition

Im letzen Jahrzehnt haben die Partei für Gerechtigkeit und Aufschwung Regierungen (JDP) eine beispiellose hyperaktiv türkische Außenpolitik betrieben, welche die Türkei zum Fokus der Aufmerksamkeit der Welt gebracht hat. Im Westen wurde die Frage "Was ist mit der Türkei passiert” mehrfach von Wissenschaftlern der türkischen Außenpolitik erhoben, von denen einige eine Verschiebung der Achse in der türkischen Außenpolitik gefunden haben. Diese Wissenschaftler behaupteten, dass die türkische Außenpolitik eine Abkehr von der westlichen Welt zum Nahen Osten und Asien erlebt. Doch die Geschichte der türkischen Außenpolitik zeigt, dass es sich nicht um eine neue Entwicklung sondern um eine schon in den 80er Jahren begonnene Transformation der türkischen Außenpolitik handelt. Diese Studie argumentiert, dass der Transformationsprozess relativ früh so um 1980 begann, als die Türkei die Liberalisierung der eigenen Wirtschaft startete, welche die türkische Gesellschaft und die türkische Wirtschaft nach außen geöffnet hat. Seither haben die Identität und Interessen des türkischen Staates einen massiven Transformationsprozess durchlaufen, um sich den tiefgreifenden Veränderungen, die in der Türkei und in der internationalen Arena stattgefunden haben, anzupassen. Zusammen mit der Liberalisierung einiger interner und externer Faktoren, wie der Globalisierung, das Ende des Kalten Krieges, der Aufstieg der JDP, der EU-Beitrittsprozess und die strategische tiefe Doktrin haben eine wichtige Rolle in der Umgestaltung der Identität und Interessen des türkischen Staates. Infolgedessen, hat die türkische Außenpolitik eine Transformation von der „Lockean Culture“, die auf Rivalität und Misstrauen basiert ist, zu „Kantian Culture“, die auf Freundschaft und Zusammenarbeit basiert ist, erlebt. Dieser Übergang wird in den breiteren Kontext der Transformation und Liberalisierung des türkischen Staates und der Gesellschaft in den letzten drei Jahrzehnten analysiert werden. Darüber hinaus wird der Prozess der Europäisierung in der Türkei und deren Auswirkungen auf die türkische Außenpolitikgestaltung ebenfalls untersucht werden. Zusätzlich wird bei der Transformation der türkischen Außenpolitik die Rolle von Ahmet Davutoglu und seinen neuen Außenpolitik Doktrin "strategische Tiefe" ebenfalls analysiert. Letztendlich wird in dieser Studie der holistische Konstruktivismus mit besonderem Schwerpunkt auf die Kultur der Anarchien Theorie der Alexander Wendt´s als theoretischer Rahmen anzuwenden sein, um ein vollständigeres Bild der Außenpolitik der JDP und die Transformation der türkischen Staats- Identität und seiner Außenpolitik in den letzten drei Jahrzehnten zu bieten.The last decade has witnessed an unprecedentedly hyperactive Turkish foreign policy under the Justice and Development Party’s administration, which has brought Turkey to the spotlight of world attention. The question “What is happening to Turkey?” has been raised many times by scholars of Turkish foreign policy in the West, some of whom have found a shift of axis in Turkish foreign policy. They claimed that Turkish foreign policy is turning away from the Western world towards the Middle East and Asia. Yet, given the history of Turkish foreign policy one may claim that it is not a recent development since Turkish foreign policy has been going through a transformation process for quite a long time. This study argues this transformation may be traced back to as early as 1980, when Turkey started the liberalization of the Turkish economy, which opened Turkish society and the Turkish economy to the outside world. Since then, Turkish state identity and interests have been going through a massive transformation process in order to adapt to the profound changes that have taken place in Turkey and in the international arena. Along with liberalization some internal and external factors, such as globalization, the end of the Cold War, the rise of the JDP, the EU membership process and the “strategic depth” doctrine have been also influential in the transformation of the Turkish state’s identity and interests. Consequently, Turkey’s foreign policy making culture has experienced a transformation from a Lockean culture based on rivalry and suspicion to a Kantian culture based on friendship and cooperation. This transition will be analyzed in the wider context of the transformation and liberalization of the Turkish state and society in the last three decades. Furthermore, the process of Europeanization in Turkey and its effects on Turkish foreign policy making will be also examined. Additionally special attention will be paid to the role of Davutoglu’s new foreign policy doctrine, “strategic depth”, in the transformation of Turkish foreign policy. Finally, this study will apply holistic constructivism as a theoretical framework with special emphasis on Alexander Wendt’s culture of anarchies theory in order to provide a fuller picture of the JDP’s foreign policy and the transformation of the Turkish state’s identity and its foreign policy in the last three decades

OPTOELEKTRONİK SENSÖR KULLANARAK NEFESTE BULUNAN SU BUHARI ANALİZİNİN ARAŞTIRILMASI

Bu çalışma kapsamında, biyomedikal uygulamalar için kullanılabilecek olan eksen-dışı kovuk-artırılmış soğurma spektroskopisine dayalı optoelektronik sensör kullanılarak nefeste bulunan su buharı analiz çalışmaları yapılmıştır. İlk önce HITRAN veri tabanı kullanılarak teorik çalışma yapılmış ve su buharı molekülünün algılanması için kullanılabilecek olan soğurma çizgisi tespit edilmiştir. Ardından, bulunan soğurma çizgisi kullanılarak nefesteki su buharı molekülü analiz edilmiştir. Bunun için 1250-1350 nm aralığında dalga boyu taranabilen dış kavite diyot lazer sistemi kullanılmıştır. Lazerden çıkan ışın, 50 cm odak uzaklığına sahip bir mercek ve bir ayna kullanılarak eksen dışı (off axis, OA) düzenekte, kovuk artırılmış soğurma spektroskopi kovuğuna bağdaştırılmıştır. Kovuk, 700 nm ile 1650 nm spektral aralığında çok yüksek geri yansıma katsayısına sahip (% 99.96), 1 m eğrilik yarıçapında ve 2.54 cm çapında iki tane aynadan oluşmaktadır. Bildiğimiz kadarıyla, su moleküllerinin analizi için ilgili spektral alan ilk defa bu çalışmada kullanılmıştır

Removal of Zinc Pollution by Using Some Hyperaccumulator Plants in Sewage Sludge Treated and Untreated Soils

Soil pollution caused by heavy metals has emerged as one of the most significant environmental problems in the world. In such environments, specific plant species are able to grow, adapt and absorb heavy metals. Phytoremediation is an emerging technology in which higher plants are used to reclaim the contaminated environment. In this study, the possibilities of removing the pollution caused by Zn, which is applied to the loamy soil together with and without sewage sludge at increasing levels (0, 75, 150, 300, 600 and 1200 μg g-1), has been researched with certain hyperaccumulator plants such as Brassica juncea, Raphanus sativus and Silene vulgaris grown in Bafra ecological conditions. In order to clean Zn added to the soil at increasing levels with or without sewage sludge by using phytoremediation technology, Silene vulgaris was found to remove the highest amount of Zn in the soil by producing the greatest amount of biomass in the ecological conditions of the region compared to Brassica juncea and Raphanus sativus, and other hyperaccumulator plants grown in the plots. Significant differences were determined in the development of plants and Zn removal between the sludge treated and untreated plots. Water-soluble Zn, which was found at high levels in the cultivation of plants at 600 and 1200 μg g-1 Zn application doses in the sewage sludge treated plots, was determined at lower levels at the end of the harvest of the plants. In the application of increasing levels of Zn with sewage sludge, the lowest organic bound Zn was determined in the plots where Silene vulgaris was grown. The highest exchangeable Zn concentration was determined in soil samples taken after the harvest of the Raphanus sativus plant among the hyperaccumulator plants grown at all Zn application doses in the trials with and without sewage sludge application

Temperature dependence of electrical properties in In/Cu2ZnSnTe4/Si/Ag diodes

WOS: 000458625200001Cu2ZnSnTe4 (CZTTe) thin films with In metal contact were deposited by thermal evaporation on monocrystalline n-type Si wafers with Ag ohmic contact to investigate the device characteristics of an In/CZTTe/Si/Ag diode. The variation in electrical characteristics of the diode was analysed by carrying out current-voltage (I-V) measurements in the temperature range of 220-360 K. The forward bias I-V behaviour was modelled according to the thermionic emission (TE) theory to obtain main diode parameters. In addition, the experimental data were detailed by taking into account the presence of an interfacial layer and possible dominant current transport mechanisms were studied under analysis of ideality factor, n. Strong effects of temperature were observed on zero-bias barrier height (Phi(B0)) and n values due to barrier height inhomogeneity at the interface. The anomaly observed in the analysis of TE was modelled by Gaussian distribution (GD) of barrier heights with 0.844 eV mean barrier height and 0.132 V standard deviation. According to the Tung's theoretical approach, a linear correlation between Phi(B0) and n cannot be satisfied, and thus the modified Richardson plot was used to determine Richardson constant (A*). As a result, A* was calculated approximately as 120.6 A cm(-2) K-2 very close to the theoretical value for n-Si. In addition, the effects of series resistance (R-s) by estimating from Cheng's function and density of surface states (N-ss) by taking the bias dependence of effective barrier height, were discussed

Magnetotransport study on AllnN/(GaN)/AIN/GaN heterostructures

Cataloged from PDF version of article.We report the effect of a thin GaN (2?nm) interlayer on the magnetotransport properties of AlInN/AlN/GaN-based heterostructures. Two samples were prepared (Sample A: AlInN/AlN/GaN and sample B: AlInN/GaN/AlN/GaN). Van der Pauw and Hall measurements were performed in the 1.9300?K temperature range. While the Hall mobilities were similar at room temperature (RT), sample B had nearly twice as large Hall mobility as sample A at the lowest temperature; 679 and 889?cm2/Vs at RT and 1460 and 3082?cm2/Vs at 1.9?K for samples A and B. At 1.910?K, the longitudinal magnetoresistance was measured up to 9?T, in turn revealing Shubnikovde Haas (SdH) oscillations. The carrier concentration, effective mass and quantum mobility of the two-dimensional electron gas (2DEG) were determined from SdH oscillations. At 1.9?K, the 2DEG concentration of sample B was nearly seven times larger than of sample A (1.67 x 10(13)/cm2 vs. 0.24 x 10(13)/cm2). On the contrary, the quantum mobility was changed adversely nearly three times (sample B 2500?cm2/Vs and sample A 970?cm2/Vs). The increase of the 2DEG concentration was attributed to the existence of the GaN interlayer, which has strengthened the spontaneous polarization difference between the AlInN and GaN layers of the heterostructure. Hence, the stronger electric field at the 2DEG region bent the conduction band profile downwards and consequently the quantum mobility decreased due to the increased interface roughness scattering

Novel VLDLR microdeletion identified in two Turkish siblings with pachygyria and pontocerebellar atrophy

Congenital ataxia with cerebellar hypoplasia is a heterogeneous group of disorders that presents with motor disability, hypotonia, incoordination, and impaired motor development. Among these, disequilibrium syndrome describes a constellation of findings including nonprogressive cerebellar ataxia, mental retardation, and cerebellar hypoplasia following an autosomal recessive pattern of inheritance and can be caused by mutations in the Very Low Density Lipoprotein Receptor (VLDLR). Interestingly, while the majority of patients with VLDLassociated cerebellar hypoplasia in the literature use bipedal gait, the previously reported patients of Turkish decent have demonstrated similar neurological sequelae, but rely on quadrupedal gait. We present a consanguinous Turkish family with two siblings with cerebellar atrophy, predominantly frontal pachygyria and ataxic bipedal gait, who were found to have a novel homozygous deletion in the VLDLR gene identified by using high-density single nucleotide polymorphism microarrays for homozygosity mapping and identification of CNVs within these regions. Discovery of disease causing homozygous deletions in the present Turkish family capable of maintaining bipedal movement exemplifies the phenotypic heterogeneity of VLDLRassociated cerebellar hypoplasia and ataxia. © Springer-Verlag 2010

Recurrent Chromosomal Copy Number Alterations in Sporadic Chordomas

The molecular events in chordoma pathogenesis have not been fully delineated, particularly with respect to copy number changes. Understanding copy number alterations in chordoma may reveal critical disease mechanisms that could be exploited for tumor classification and therapy. We report the copy number analysis of 21 sporadic chordomas using array comparative genomic hybridization (CGH). Recurrent copy changes were further evaluated with immunohistochemistry, methylation specific PCR, and quantitative real-time PCR. Similar to previous findings, large copy number losses, involving chromosomes 1p, 3, 4, 9, 10, 13, 14, and 18, were more common than copy number gains. Loss of CDKN2A with or without loss of CDKN2B on 9p21.3 was observed in 16/20 (80%) unique cases of which six (30%) showed homozygous deletions ranging from 76 kilobases to 4.7 megabases. One copy loss of the 10q23.31 region which encodes PTEN was found in 16/20 (80%) cases. Loss of CDKN2A and PTEN expression in the majority of cases was not attributed to promoter methylation. Our sporadic chordoma cases did not show hotspot point mutations in some common cancer gene targets. Moreover, most of these sporadic tumors are not associated with T (brachyury) duplication or amplification. Deficiency of CDKN2A and PTEN expression, although shared across many other different types of tumors, likely represents a key aspect of chordoma pathogenesis. Sporadic chordomas may rely on mechanisms other than copy number gain if they indeed exploit T/ brachyury for proliferation

DNaseI Hypersensitivity and Ultraconservation Reveal Novel, Interdependent Long-Range Enhancers at the Complex Pax6 Cis-Regulatory Region

The PAX6 gene plays a crucial role in development of the eye, brain, olfactory system and endocrine pancreas. Consistent with its pleiotropic role the gene exhibits a complex developmental expression pattern which is subject to strict spatial, temporal and quantitative regulation. Control of expression depends on a large array of cis-elements residing in an extended genomic domain around the coding region of the gene. The minimal essential region required for proper regulation of this complex locus has been defined through analysis of human aniridia-associated breakpoints and YAC transgenic rescue studies of the mouse smalleye mutant. We have carried out a systematic DNase I hypersensitive site (HS) analysis across 200 kb of this critical region of mouse chromosome 2E3 to identify putative regulatory elements. Mapping the identified HSs onto a percent identity plot (PIP) shows many HSs correspond to recognisable genomic features such as evolutionarily conserved sequences, CpG islands and retrotransposon derived repeats. We then focussed on a region previously shown to contain essential long range cis-regulatory information, the Pax6 downstream regulatory region (DRR), allowing comparison of mouse HS data with previous human HS data for this region. Reporter transgenic mice for two of the HS sites, HS5 and HS6, show that they function as tissue specific regulatory elements. In addition we have characterised enhancer activity of an ultra-conserved cis-regulatory region located near Pax6, termed E60. All three cis-elements exhibit multiple spatio-temporal activities in the embryo that overlap between themselves and other elements in the locus. Using a deletion set of YAC reporter transgenic mice we demonstrate functional interdependence of the elements. Finally, we use the HS6 enhancer as a marker for the migration of precerebellar neuro-epithelium cells to the hindbrain precerebellar nuclei along the posterior and anterior extramural streams allowing visualisation of migratory defects in both pathways in Pax6(Sey/Sey) mice

Breakpoint mapping of 13 large parkin deletions/duplications reveals an exon 4 deletion and an exon 7 duplication as founder mutations

Early-onset Parkinson’s disease (EOPD) has been associated with recessive mutations in parkin (PARK2). About half of the mutations found in parkin are genomic rearrangements, i.e., large deletions or duplications. Although many different rearrangements have been found in parkin before, the exact breakpoints involving these rearrangements are rarely mapped. In the present study, the exact breakpoints of 13 different parkin deletions/duplications, detected in 13 patients out of a total screened sample of 116 EOPD patients using Multiple Ligation Probe Amplification (MLPA) analysis, were mapped using real time quantitative polymerase chain reaction (PCR), long-range PCR and sequence analysis. Deletion/duplication-specific PCR tests were developed as a rapid and low cost tool to confirm MLPA results and to test family members or patients with similar parkin deletions/duplications. Besides several different deletions, an exon 3 deletion, an exon 4 deletion and an exon 7 duplication were found in multiple families. Haplotype analysis in four families showed that a common haplotype of 1.2 Mb could be distinguished for the exon 7 duplication and a common haplotype of 6.3 Mb for the deletion of exon 4. These findings suggest common founder effects for distinct large rearrangements in parkin