TOBB ETU GCRIS Database
Not a member yet
9778 research outputs found
Sort by
A Review on Recent Advances of Chemical Vapor Deposition Technique for Monolayer Transition Metal Dichalcogenides (mx2: Mo, W; S, Se, Te)
No full textTransition metal dichalcogenide (TMD) monolayers have recently garnered significant attention owing to their favorable electronic and optoelectronic properties. To date, chemical vapor deposition (CVD) growth of molybdenum di-sulfide, -selenide, and -telluride (MoS2, MoSe2, and MoTe2, respectively), and tungsten di-sulfide, -selenide, and -telluride (WS2, WSe2, and WTe2, respectively) has been widely investigated as the most promising two-dimensional (2D) TMDs. However, scalable and controllable growth of high-quality TMD monolayers remains a challenge. This review highlights the advances of CVD technique by focusing on the aspects of growth promoters, surface energy assistance and site selectivity, which are of great significance for the growth of monolayer TMDs. The challenges for high-performance applications are discussed at the end with a brief outlook on future work. © 2022 Elsevier LtdTürkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 118C524, 118E996, 121M601, 20AG001, 20AG025This work was supported by The Scientific and Technological Research Council of Turkey , Research Project Numbers: TÜBİTAK 121M601 , TÜBİTAK 118C524 , TÜBİTAK 118E996 , TÜBİTAK 20AG025 , TÜBİTAK 20AG001
Çarpisma Bölgesi Simülasyonu Yapilarak Parçacik Çarpistiricilarinin Olasi Çarpisma Verimliliginin ve Sürdürülebilirligin Belirlenmesi
No full textThe importance of particle colliders, the first examples of which were established in the 1960s, in high energy physics research is increasing exponentially. Since the 1970s, heavy fermions (c-quark, t-quark, and tau-lepton), intermediate bosons (gluon, W, Z and Higgs boson) predicted by the Standard Model have been discovered by particle colliders. Particle colliders can be divided into three types in terms of colliding particles: lepton, hadron, and lepton-hadron. As for collider types, there are three different options: circular, linear and linac-ring. In terms of high energy physics, the most important parameters of colliders are center of mass energy and luminosity. However, there are many beam parameters that need to be controlled. The most important of these are beam-beam tuneshift for the beam in the ring and disruption in the linac. AloHEP software developed by TOBB ETU YEF group allows to calculate the main parameters of different types and options of colliders. The beam parameters in various publications suggesting a new design of a collider were entered into the AloHEP software, and the basic parameters of the colliders were obtained with analytical and numerical calculations, and it was seen that the values given in some publications were incorrect. In order to prevent this situation, the parameters of the proposed colliders can be entered into the AloHEP software, and their basic parameters can be checked. Therefore more realistic designs can be provided.İlk örnekleri 1960'larda kurulan parçacık çarpıştırıcılarının yüksek enerji fiziği araştırmalarındaki önemi katlanarak artmaktadır. 1970'lerden itibaren Standart Modelin öngördüğü ağır fermiyonlar (c-kuark, t-kuark ve tau-lepton), ara bozonlar (gluon, W, Z ve Higgs bozonu) parçacık çarpıştırıcılar sayesinde keşfedilmiştir. Parçacık çarpıştırıcıları çarpışan parçacıklar açısından üç türe ayrılabilir: lepton, hadron ve lepton-hadron. Çarpıştırıcılara tasarımlarına göre bakıldığında ise dairesel, doğrusal ve linak-halka olmak üzere üç farklı seçenek mevcuttur. Yüksek enerji fiziği açısından çarpıştırıcılarının en önemli parametreleri kütle merkezi enerjisi ve ışınlıktır. Bununla birlikte kontrol altında tutulması gereken çok sayıda demet parametreleri vardır. Bunların en önemlileri halkadaki demet için demet-demet ayar kayması ve linaktaki demet için bozulmadır. TOBB ETÜ YEF grubu tarafından geliştirilen AloHEP yazılımı farklı tip ve türlerdeki çarpıştırıcıların ana parametrelerini hesaplamaya imkân sağlamaktadır. Çarpıştırıcı önerilerinde bulunan çeşitli yayınlardaki demet parametreleri AloHEP yazılımına girilerek analitik ve numerik hesaplamalar ile çarpıştırıcıların temel parametreleri elde edilmiş ve bazı yayınlarda verilen değerlerin yanlış olduğu görülmüştür. Bu durumun önüne geçmek için önerilen çarpıştırıcıların parametreleri öncelikle AloHEP yazılımıyla denenerek temel parametreleri kontrol edilebilir ve böylece daha gerçekçi tasarımların ortaya konulması sağlanabilir
Transfer Learning for Predicting Gene Regulatory Effects of Chemicals
No full text18th International Conference on Artificial Intelligence Applications and Innovations (AIAI) -- JUN 17-20, 2022 -- Hersonissos, GREECEAmong the recent developments in bioinformatics and chemogenomics, various deep learning methods have been the most prevalent [4,5,9]. This resulted in an over-saturation of powerful models that easily pushed the limits of existing datasets. Subsequently, many novel advancements have been done with improvements to the datasets. Amidst these advancements, researchers of Deep Compound Profiler (DeepCOP) [10] set themselves apart with a novel method of introducing new features whilst keeping the deep learning model relatively basic. In this study, we propose to take this novel method one step further by applying transfer learning between cell lines. In order to better evaluate the benefits of transfer learning, we've introduced 2 drug-based data splits. The transfer learning method, as its core, utilizes the learned knowledge of source cell lines to give a head start to target cell lines. Taking advantage of prior knowledge from source cell lines not only boosts existing compounds' effect prediction, but it can also be used as a premonition for the compounds' (explicit to the source), effects on target cell lines before they are tested in real life. Our experiments showed improvements up to 22.81% improvement on area under ROC curve (AUC) on the split closest to a wet lab experiment
Üç İsim Dört Mevsim : Ahmet Hamdi Tanpınar, Mehmet Kaplan, Orhan Okay
No full text[No Abstract Available
Parenteral Methotrexate Is Efficient in the Treatment of Azathioprine Refractory Crohn's Disease
No full textBackground: There is limited data in the literature analyzing the efficacy of methotrexate in Crohn's disease used after thiopurine analogs. We aimed in our study to show the efficacy of methotrexate in Crohn's disease patients who failed to respond to thiopurine treatment. Methods: The study included 29 azathioprine refractory patients with Crohn's disease. Intramuscular methotrexate (25 mg/week) in the induction of remission and intramuscular methotrexate (15 mg/week) in 29 CD patients with a median follow-up time of 13 months was performed. In 15 (51.7%) patients, methotrexate was used in combination with anti-Tumour necrosis factor (TNF) (combination group), while it was used in 14 (48.3%) patients in monotherapy (monotherapy group). Results: The mean Harvey-Bradshaw index score significantly decreased in the follow-up period (Wk0 = 7.6, last visit = 4.5, P .001). Remission and response rates at week 12 were 75.9% and 79.3%, respectively. Maintenance of remission (77.8% vs 37.5%, respectively, P=.1)and response rates (77.8% vs 50%, respectively, P = .3) due to last visit examination were numerically higher in combination group but they were not statistically significant. The cumulative probability of remission maintenance in patients with methotrexate therapy was 72.7%, 33.1%, and 22.0% at 1, 2 ,and 4 years after starting methotrexate, respectively. Conclusion: Our results show that parenteral use of methotrexate is efficacious in inducing and maintaining remission as a step-up agent in azathioprine refractory Crohn's disease patients
Kredi Temerrüt Takası Primi Belirleyicileri: Gelişmiş ve Gelişmekte Olan Ülkeler Üzerine Karşılaştırmalı Analiz
No full textCredit default swap (CDS) premium, which has gained importance since the global financial crisis, is frequently used in financial markets as a credit derivative and is accepted as credit risk indicator of countries. The thesis aims to determine the effect of macroeconomic and financial variables on CDS premiums in developed and developing countries. In the study in which the Driscoll-Kraay Standard Error Estimator of panel data econometrics was applied, the common determining factors of CDS premiums for developed and developing countries were defined as inflation, stock market index and growth rate. In addition to the common factors, unemployment rate and interest rate of government bonds in developed countries and current account deficit in developing countries were found to be statistically significant. According to the analysis results, the model explains the CDS premiums by 65% in developed countries, while it explains 30% in developing countries. This result indicates that the model is more appropriate for explaining risk status of developed countries, whereas the effect of macroeconomic and financial variables is limited in explaining the risk status of developing countries. In addition, it is observed that various country-specific factors such as political uncertainty and risk, apart from macroeconomic and financial variables, impact the determination of risk in developing countries.Küresel finans krizinden itibaren önem kazanan kredi temerrüt takası (CDS) primi, kredi türevi olarak finansal piyasalarda sıklıkla kullanılmaktadır ve ülkelerin kredi risk göstergesi olarak kabul edilmektedir. Bu tezin amacı, gelişmiş ve gelişmekte olan ülkelerde makroekonomik ve finansal değişkenlerin CDS primlerine olan etkisini incelemektir. Panel veri ekonometrisi Driscoll-Kraay Standart Hata Tahmincisinin kullanıldığı çalışmada, gelişmiş ve gelişmekte olan ülkeler için, CDS primlerinin ortak belirleyici faktörleri enflasyon, borsa endeksi ve büyüme oranı olarak belirlenmiştir. CDS primlerinin belirlenmesinde ortak faktörlere ek olarak; gelişmiş ülkelerde işsizlik oranı ve gösterge faiz oranı değişkeni, gelişmekte olan ülkelerde ise cari açık değişkeni istatistiki olarak anlamlı bulunmuştur. Analiz sonuçlarına göre kurulan model gelişmiş ülkelerde CDS primlerini %65 oranında açıklarken gelişmekte olan ülkelerde ise %30 oranında açıklamaktadır. Bu sonuç, modelin gelişmiş ülkelerin risk durumunu açıklamada daha başarılı olduğunu, gelişmekte olan ülkelerin risk durumunu açıklamada ise makroekonomik ve finansal değişkenlerin etkisinin sınırlı olduğunu göstermektedir. Ayrıca, gelişmekte olan ülkelerde riskin belirlenmesinde makroekonomik ve finansal değişkenlerin yanı sıra siyasi belirsizlik ve politik risk gibi ülkelere özgü çeşitli faktörlerin de etkili olduğu görülmektedir
