Şevket Süreyya Aydemir:"Suyun bulanması, galiba yolun yitirilmesi pahasına oldu" demişti

Taha Toros Arşivi, Dosya No: 476-Şevket Süreyya Aydemi

Teachers' attitudes towards and practices of L1 use in EFL classroom

Ankara : The Department of Teaching English as a Foreign Language, Bilkent University, 2014.Thesis (Master's) -- Bilkent University, 2014.Includes bibliographical refences.This study explored teachers’ attitudes towards their use of L1 in language classrooms and their practices in terms of use of L1 both as a communicative and methodological tool. The study was conducted with the participation of 120 teachers teaching at Anadolu University School of Foreign Languages, who were asked to fill a questionnaire survey developed by the researcher. The questionnaire’s focus was on the teachers’ attitudes and practices as a communicative tool and methodological tool. While answering the practices parts, teachers were asked to take the lesson and the level that they were teaching into account. The results of the quantitative analysis revealed that the teachers mostly had negative attitudes towards the use of L1, especially towards its use as a communicative tool; however, the teachers did not believe that L1 had negative effect on L2 acquisition. They were in favor of L1 since they believed that the learners did not have any other opportunity to access the target language. Thus, they believed that they should interact with the learners in TL as much as possible. This study implied that further research is needed to find out the variables which affect the teachers code-choices in more detail and see the picture from the students’ point of view.Tunçay, BaharM.S

Okuyuculara mektup

Taha Toros Arşivi, Dosya No: 476-DarülelhanUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010

The Effect of Zr on LM6 Aluminum Alloy

Bu çalışmada, konvansiyonel döküm yöntemiyle üretilen ve alaşımların mikroyapı ve mekanik özellikleri üzerine farklı miktarlarda Zr (% 0,05 ve 0,15) içeren LM6 alaşımları üzerindeki Zr miktarının etkisi incelenmiştir. Ek olarak, üretilen alaşımlar 200-250 ppm Strontium (Sr) ile modifiye edilmiştir. Mikroyapı analizlerinde optik mikroskop (OM) ve taramalı elektron mikroskobu (SEM / EDS analizi) kullanılmıştır. Farklı miktarlarda zirkonyum ilave edilen ve Sr ile modifiye edilmiş alaşımların sertlik ve gerilme testleri yapılmıştır. Yapılan çalışmalar sonucunda, optik mikroskop (OM) ve taramalı elektron mikroskobu (SEM) görüntülerinde, Al-Si-Fe fazının morfolojisinin Zr ilavesine bağlı olarak değişmiştir. En yüksek yüzde uzama Al12Si alaşımından elde edilirken, stronsiyum tarafından modifiye edilen LM6 alaşımından en yüksek sertlik ve maksimum gerilme dayanımı elde edilmiştir. En yüksek akma dayanımı 0.05 Zr ile alaşımlı olan LM6 alaşımından elde edilmiştir.. Eklenen Zr miktarının, Al12Si alaşımının maksimum çekme dayanımında önemli bir fark göstermediği bulunmuştur.In this study, the effect of Zr amount on LM6 alloys which were produced by conventional casting method and contained different amounts of Zr (0.05% and 0.15) on the microstructure and mechanical properties of the alloys was investigated. In addition, produced alloys were modified with 200-250 ppm Strontium (Sr). optic microscope (OM) and scanning electron microscopy (SEM / EDS analysis) were used for microstructure analysis. The hardness and tensile tests of the alloys which were modified by Sr and alloyed with different amounts of zirconium were performed. As a result of the studies that were done, it was determined in the images of optical microscope (OM) and scanning electron microscope (SEM) that the morphology of Al-Si-Fe phase changed depending on the addition of Zr, and that Al-Si-Fe intermetalics having different amounts of Zr composed. While the highest level of percent elongation was obtained from the Al12Si alloy, the highest level of hardness and maximum tensile strength were obtained from the LM6 alloy modified by strontium. The highest level of yield strength was obtained from LM6 alloy which was alloyed with 0.05 Zr. It was found that the amount of added Zr did not show a significant difference at the maximum tensile strength level of Al12Si alloy

The Effects of Macroeconomic Indicators on Leveraged Forex Volume: Evidence from Turkey

In this study, the effects of macroeconomic indicators on leveraged forex volumes of financial intermediary institutions have been analyzed. The study covers the data for the period 2013Q1-2017Q2 of 16 financial intermediary institutions operating in Turkey. In the study in regards to macroeconomic indicators, BIST 100 Index revenues (BIST), consumer price index (CPI), consumer confidence index (CCI), average rate applied to deposits opened by banks (INT), gold prices (GOLD), money supply (M2), external trade export unit index (EUVI) and unemployment rate (UNEMP) have been used. In the study, the effects of macroeconomic indicators on leveraged forex volume have been examined through panel data analysis. As a result of the panel data analysis, it has been determined that the BIST, M2, EUVI and UNEMP variables have positive significant effects on leveraged forex volume and that the INT variable has negative significant effects on leveraged forex volume. In the study, the effects of CPI, CCI and GOLD variables on leveraged forex volume are statistically insignificant

Microwave Breast Models Through T1-weighted 3-d Mri Data

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013Son yıllarda, meme kanserinin erken teşhisi konusunda mikrodalga görüntüleme alanında yapılan çalışmalar popülerlik kazanmıştır. Bu bağlamda, insan memesinin elektromanyetik sayısal modelleri bu konuda çalışan araştırmacılara, hızlı deneysel analizler yaparak yeni teknolojilerin fizibilitesinin artırılması ve böylece daha iyi görüntüleme tekniklerinin ve aygıtlarının geliştirilmesi konularında yardımcı olmaktadır. Literatürde özel olarak sayısal mikrodalga meme modellerini konu alan bu ilk çalışmada arzu edilen türde bir model üretilebilmesi için 3 ana adım içeren bir yöntem öne sürülmüştür. Bu yöntemin alt adımları kısaca: MRI verisindeki gürültünün homomorfik filtreleme ile giderilmesi, dokuların Gauss Karışım Modeli (GMM) ile segmentasyonu ve elektromanyetik özelliklerin parçalı-doğrusal eşleme fonksiyonları ile eşlenmesi olarak tarif edilebilir. Bu çalışmada, mikrodalga meme görüntülemesi çalışmalarında kullanılmak üzere değişik şekil, ebat ve radyografik yoğunluklarda 3-boyutlu sayısal mikrodalga meme modelleri üretilmesi için etkin ve kendi kendine işleyebilen bir yöntem sunulmuştur. Memenin heterojen yapısının mekânsal bilgisi, memelerinde bir anomaliye rastlanmayan değişik hastaların yüz üstü pozisyonda alınmış T1-ağırlıklı 3-boyutlu MRI verileri kullanılarak elde edilmiştir. Dokulara ait her bir sınıf ile elektromanyetik özellikler arasında tekdüze parçalı kübik Hermitte interpolasyon yöntemi kullanılarak doğrusal olmayan bir ilişki kurulmuştur. İlgili meme dokularının elektromanyetik özellikleri Debye and Cole-Cole dağılım modelleri üzerinden tercih edilen çalışma frekansına göre belirlenmiş, böylece MRI verisindeki her bir voksel değeri uygun bağıl geçirgenlik ve iletkenlik değerleri ile eşlenmiştir. Bağıl geçirgenlik ve iletkenlik dağılımlarına dönüştürülen MRI kesitleri, doğrusal interpolasyon ile 3-boyutlu ve gerçekçi bir yapıya dönüştürülmüştür.Recent years, early detection of breast cancer in the field of electromagnetic imaging has gained high popularity. In this context, computational electromagnetic models of the human breast are used to help researchers develope better techniques and instruments for imaging, increasing the feasibility of new technologies, and doing fast experimental analysis. In this study, an effective and automated methodology for realistic numerical 3-D breast phantom development of different shapes, size and radiographic density in order to be used for different electromagnetic simulation models in microwave breast imaging research is presented. The spatial information of heterogeneity of the breast structure is collected from T1-weighted MRI slices of different patients’ in prone position with normal breast tissue (not malignant or abnormal). Each voxel in MRI data was mapped to the appropriate dielectric properties using several steps. First, bias field appears on each slice in MRI data was estimated and eliminated. After filtering of all slices, voxels belong to adipose and glandular tissues were classified into four categories. Then those tissue categories were related to electromagnetic properties of relative permittivity and conductivity by monotone piecewise polynomial cubic Hermite interpolation. Electromagnetic properties of the breast tissue are expanded to desired frequency using Debye dispersion models. Each voxel intensity value is nonlinearly mapped to the appropriate electromagnetic properties of the corresponding breast tissue. Later, the resultant slices of permittivity and conductivity are linearly interpolated to form a proper 3-D breast structure.Yüksek LisansM.Sc

The Effects of Nanoparticle Reinforcement on the Micromilling Process of A356/Al2O3 Nanocomposites

Abstract Improving scientific knowledge around the manufacturing of nanocomposites is key since their performance spreads across many applications, including those in meso/micro products. Powder metallurgy is a reliable process for producing these materials, but usually, machining postprocessing is required to achieve tight tolerances and quality requirements. When processing these materials, cutting force evolution determines the ability to control the microcutting operation toward the successful surface and part quality generation. This paper investigates cutting force and part quality generation during the micromilling of A356/Al2O3 aluminum nanocomposites produced via powder metallurgy. A set of micromilling experiments were carried out under various process parameters on nanocomposites with different nano-Al2O3 reinforcements (0–12.5 vol.%). The material’s ductility, internal porosity, and lack of interparticle bonding cause the cutting force generation to be irregular when nanoparticle reinforcements were absent or small. Reinforcement ratios higher than 2.5 vol.% strongly affect the cutting process by regularizing the milling force generation but lead to a proportionally increasing average force magnitudes. Hardening due to nano-reinforcement positively affects cutting mechanisms by reducing the plowing tendency of the cutting process, resulting in better surface quality. Therefore, a threshold on the nano-Al2O3 particles’ volumetric loadings enables an optimal design of these composite materials to support their micromachinability