Asma Köprülerin Analiz Yöntemleri

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada, asma köprülerin deterministik ve stokastik dinamik analizleri; geometrik olarak lineer olmayan davranış dikkate alınarak incelenmektedir. Uygulama olarak Boğaziçi Asma Köprüsü seçilmiştir. Yer hareketi olarak 1971 San Fernando depremi Pacoima Barajı S16E bileşeni ile 1992 Erzincan depremi doğu-batı bileşeni ivme kayıtları kullanılmaktadır. Stokastik analizlerde yer hareketini temsil etmek üzere Clough ve Penzien tarafından düzeltilerek elde edilen filtre edilmiş beyaz gürültü modeli dikkate alınmaktadır. Yer hareketi modeli, mesnetlere etkiyen yer hareketlerinin yansıma ve kırılmalarla değişebilir olmasından kaynaklanan korelasyon etkisini, dalga yayılma etkisini ve zemin özelliklerinin yer hareketine etkisini içermektedir. Analizler sonucunda köprü kuleleri ve tabliyesine ait yerdeğiştirme ve kesit tesirleri elde edilmiştir. Yer tabakasının karmaşık yapısından dolayı, yer hareketlerinin farklı noktalardaki değişiminden doğan etkilerin asma köprüler gibi uzun açıklıklı sistemlerin deterministik ve stokastik analizlerinde dikkate alınması gerektiği vurgulanmaktadır.In this study, deterministic and stochastic dynamic responses of suspension bridges are investigated by considering geometrically nonlinear behavior. Bosporus Suspension Bridge is chosen as an example. S16E component of Pacoima Dam record of 1971 San Fernando earthquake and east-west component of 1992 Erzincan earthquake are used as ground motions. Filtered white noise model modified by Clough and Penzien is considered as a ground motion in the stochastic analyses. The ground motion model includes the effects of incoherence, wave passage, and site response. The bridge towers and deck displacement and internal forces are obtained in the end of the analyses. Because of the complex nature of earth crust, it is emphasized that the multiple support seismic excitations should be taken into account in the deterministic and stochastic analyses of long span structures like suspension bridges

Beden Eğitimi Derslerinde Kullanılan Farklı Öğretim Yöntemlerinin Akademik Öğrenme Zamanına Etkisi

This study aims at seeing the effects of different teaching styles on student behaviours and course content activities and academic learning time in physical education scores. The participants are 30 grade four students at Abant İzzet Baysal University, Department of Teaching Physical Education during 2010–2011 academic year. Forty minute lessons of 30 pre-service teachers using command style (n=10), practice style (n=10) and reciprocal style (n=10) were videotaped and recordings were examined using the “observation form of academic learning time in physical education”. The results of the analysis revealed that significant differences among academic learning time and three different teaching styles were utilized by pre-service teachers in physical education and sport classes. As a result of this study, academic learning time has been concluded in lessons using practice style at most, then the reciprocal style, at least the command style.Bu çalışmanın amacı, beden eğitimi öğretmen adaylarının öğretmen etkililiğini belirlemeye yönelik ders içerikleri ve öğrenci davranışları boyutlarına ait zamanları ve Beden Eğitimi derslerindeki akademik öğrenme zamanlarını belirleyerek, Beden Eğitimi derslerinde kullanılan farklı öğretim yöntemlerinin bu zamanlar üzerine etkisini tespit etmektir. Çalışma grubunu, 2010–2011 öğretim yılında Abant İzzet Baysal Üniversitesi, Beden Eğitimi Öğretmenliği Bölümü’nde öğrenim gören otuz 4. sınıf öğrencisi (öğretmen adayı) oluşturmuştur. Komut yöntemi (n=10), alıştırma yöntemi (n=10) ve eşli çalışma yöntemi (n=10) ile ders işleyen 30 öğretmen adayının 40 dakikalık birer dersi videoya kaydedilmiş ve “Beden Eğitimi’nde akademik öğrenme zamanı gözlem formu” kullanılarak analiz edilmiştir. Yapılan istatistiksel analizler sonucunda Beden Eğitimi’nde akademik öğrenme zamanı boyutlarında gruplar arasında anlamlı farklar bulunmuştur. Bu çalışma sonucunda, akademik öğrenme zamanın en çok alıştırma yönteminde, daha sonra eşli çalışma yönteminde, en az ise komut yöntemiyle işlenen derslerde gerçekleştiği sonucuna ulaşılmıştır

Comparison of HCV core antigen and anti-HCV with HCV RNA results

Background: The measurement of anti-HCV antibodies using immunological methods and the confirmation of viral nuclear acid based on molecular methods is important in diagnosis and follow-up of the HCV infection.Objectives: In this study, we aimed to analyse HCV core Antigen positivity among anti-HCV antibody positive sera to determine the significance of testing of HCV core Ag for the laboratory diagnosis of HCV infection, by considering the correlation between serum HCV core Ag and HCV RNA levels.Methods: 115 patients suspected of having hepatitis C and who were positive for anti-HCV antibody were investigated using chemiluminescent and molecular methods. Anti-HCV antibody, HCV core Ag and HCV RNA levels were detected by the Vitros ECiQ immunodiagnostic system, Architect i2000 system and RT-PCR, respectively.Results: The sensitivity, specificity, positive and negative predictive values and accuracy rate of HCV core Antigen assay were detected as 86.5%(83/96), 100%(19/19), 100%(83/83), 59.4%(19/32), 88.7%(102/115) respectively.Conclusion: HCV core Ag assay could be used for diagnosis of HCV infection as it is easy to perform, cost-effective, has high specificity and positive predictive value. However, it should be kept in mind that it may have lack of sensitivity and negative predictive value.Key Words: HCV, anti-HCV antibody, HCV core Ag, HCV RN

Thoracopagus Conjoined Twins: A Case Report

Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonography at an 11-week gestation, termination of the pregnancy was performed. Conclusion. Making an early diagnosis with ultrasonographic examination gives the parents a chance to elect pregnancy termination

First principles modelling of magnesium titanium hydrides

Mixing Mg with Ti leads to a hydride Mg(x)Ti(1-x)H2 with markedly improved (de)hydrogenation properties for x < 0.8, as compared to MgH2. Optically, thin films of Mg(x)Ti(1-x)H2 have a black appearance, which is remarkable for a hydride material. In this paper we study the structure and stability of Mg(x)Ti(1-x)H2, x= 0-1 by first-principles calculations at the level of density functional theory. We give evidence for a fluorite to rutile phase transition at a critical composition x(c)= 0.8-0.9, which correlates with the experimentally observed sharp decrease in (de)hydrogenation rates at this composition. The densities of states of Mg(x)Ti(1-x)H2 have a peak at the Fermi level, composed of Ti d states. Disorder in the positions of the Ti atoms easily destroys the metallic plasma, however, which suppresses the optical reflection. Interband transitions result in a featureless optical absorption over a large energy range, causing the black appearance of Mg(x)Ti(1-x)H2.Comment: 22 pages, 9 figures, 4 table

ÇOCUKLARIN RESİMLERİNDEKİ AİLEYİ TANILAMA DURUMLARININ DEĞERLENDİRİLMESİ

Çocuklar resim yoluyla bize duygularınıyansıtabilirler ve olaylar hakkındaki his ve düşüncelerini ifade edebilirler. Çocuğun yaptığıresimler onun iç dünyasının aynasıolarak kabul edilmektedir. Bu düşüncelerden yola çıkarak çocuk resmi konusunda pek çok araştırma yapılmıştır. Bu çalışmada; çocuk resminde aile kavramıdeğerlendirilmeye çalışılmıştır. Çalışmaya Türkiye’den Konya İli Meram ve Selçuklu İlçelerinden ilköğretim okullarına devam eden 8-14 yaşarası66 öğrenci ve Almanya’nın Berlin Şehrinde 8-14 yaşarası58 öğrenci olmak üzere toplam 124 öğrenci alınmıştır. Öğrencilere zihinsel boyutu değerlendirmek amacıile Goodenough Harris Adam Çizme Testi uygulanmıştır. Ayrıca öğrencilerden aile kavramınıdeğerlendirmek amacıile birer aile resmi çizmeleri istenmiştir. Çalışmanın sonucunda her iki ülkede yaşayan çocukların cinsiyetine göre resim çizme ve aileyi tanıma durumlarıarasında kızların erkeklerden daha başarılıolduklarıve yaşilerledikçe aileyi tanıma düzeyinin yükseldiği gözlenmiştir. Ayrıca kardeşsayısına göre aileyi tanıma puanlarıfarklılaşmaktadır, okul başarısıyüksek olan öğrencilerin goodenhough harris testinden aldılarıpuan daha yüksek bulunmuştur

Role of free radicals in peptic ulcer and gastritis

Background/aims: It has been suggested that the free radicals are closely related with peptic ulcer disease and gastritis. Although many studies have been undertaken to clarify the role of oxygen-derived free radicals, most of them were carried out in animal models. The aim of this study was to assess the reactive oxygen species activity and the damage in Helicobacter pyloriinfected gastric mucosa in humans. Methods: In a total group of 42, there were fifteen cases of peptic ulcer, 14 cases of gastritis and 12 control subjects. Measurement of gastric mucosal malondialdehyde concentrations, which is the end - product of lipid peroxidation, was used to assess oxidative damage to membranes in patients with peptic ulcer and gastritis. Mucosal reduced glutathione glutathione concentrations were also measured in order to study whether reactive oxygen species generation affects levels of the antioxidant peptide, malondialdehyde and glutathione content was then measured in biopsies taken from the gastric antrum. Results: Tissue levels of glutathione were significantly (p <0.001) and malondialdehyde was higher (p<0.001) in patients with peptic ulcer compared to controls. In patients with gastritis, glutathione was also lower (p<0.001) and malondialdehyde higher (p<0.01). Conclusions: Depletion of gastric mucosal glutathione in cases with H.pylori positive peptic ulcer and gastritis may be caused by accumulation of free radicals that can initiate membrane damage by lipid peroxidation

Bilateral Severe Sterile Inflammation with Hypopyon after Simultaneous Intravitreal Triamcinolone Acetonide and Aflibercept Injection in a Patient with Bilateral Marked Rubeosis Associated with Ocular Ischemic Syndrome

We report the clinical course of a diabetic patient with bilateral cataract and rubeosis in association with ocular ischemic syndrome and initially treated him with simultaneous intravitreal 2 mg aflibercept and 2 mg triamcinolone acetonide injection at the same setting prior to planned cataract surgery and further photocoagulation. However, sterile anterior segment inflammation characterized by hypopyon occurred four days apart in OU. Right eye developed the sterile inflammation at the third postinjection day and the left eye developed the sterile inflammation at the seventh postinjection day (two days after the uneventful cataract surgery with intraocular lens implantation) without any pain or significant redness. Vitreous biopsy taken during the right phacovitrectomy was negative for any microbial contamination. Both eyes were treated successfully with intensive topical prednisolone acetate with a relatively good visual outcome. It is likely that underlying ocular ischemic syndrome might have facilitated the formation of sterile inflammation as blood-aqueous barrier disruption and flare have already been present

Haptic dokunma hisli ve kuvvet geri beslemeli arayüz sistem tasarımı

TÜBİTAK MAG01.07.2008“Haptic” cihaz, kullanıcı ile bilgisayar arasında üç boyutlu veri transferi sağlayan bir cihazdır. Bu cihaz kullanıcıya sanal ortamdaki bir nesneyi görmenin yanında, bu sanal nesneye dokunma olanağı da sağlar. Aynı zamanda bu cihaz ile gerçek bir nesneden veriler alınarak bu verilerin sanal ortamda kullanımı da gerçekleştirilebilir. Günümüzde sanal gerçeklik teknolojisinin gelişimine paralel olarak “haptic” cihazlarının kullanımı, sanayi, eğitim ve tıp alanlarında gittikçe artmaktadır. Bu teknolojinin değişik uygulama alanları, farklı bilim dallarına ait disiplinlerarası çalışmaları gerektirdiğinden, kendi içinde özgün çalışma konularını da yaratmaktadır (“haptic” arayüz tasarımı, serbest modelleme, sanal ortamda ameliyat eğitimi, vb.). Medikal uygulamalarda önemli bir potansiyele sahip bu teknoloji ile daha önceleri el işçiliği ile yapılmak zorunda kalınan karmaşık modifikasyonlar gerçekleştirilebilmektedir (beyin cerrahisinde hata kabul etmeyen, ustalık ve ameliyat öncesi uzun uğraşlar gerektiren operasyonlar). Bu örnek “haptic” cihazlar ile dijital ortamda gerçekleştirilebilecek olan uygulamalardan sadece bir tanesidir. Bu proje kapsamında, bahsedilen uygulama alanlarına yönelik 7 serbestlik dereceli bir “haptic” cihaz tasarlanıp üretilmiş ve cihazın kullanılabilirliğini göstermek için bir arayüz tasarlamıştır. Günümüze kadar tasarlanmış olan bütün “haptic” cihazlar maksimum 6 serbestlik derecesine sahiptirler. Tasarlanan 7 serbestlik dereceli “haptic” cihaz, bugüne kadar üretilmiş aynı uzuv uzunlukları ve eklem değişkenlerine sahip diğer “haptic” cihazlar ile karşılaştırıldığında yaklaşık %20 daha büyük bir çalışma hacmine ve daha esnek bir çalışma kabiliyetine sahiptir. Bu çalışma, Dünya’daki “haptic” cihazların geliştirilmesi ve Türkiye’deki “haptic” cihazların ve uygulama alanlarının yaygınlaşması açısından son derece önemlidir.Haptic devices are used to provide multi-modal data transfer between haptic users and computers in virtual reality applications. They enable humans to take force and tactile feedback from any virtual or remote objects. Haptic devices also facilitate the use of data collected from a real object in the virtual environment. Usage of the haptic devices increase more and more in industrial, educational and medical applications in parallel with development of virtual reality technology. As virtual reality technology requires interdisciplinary study with related to its application areas, it creates a lot of different specific working areas (Haptic interface design, freeform model, surgical operations in virtual environment etc.). Especially, some complex modifications which require hand-working can be performed with the system having great potential in medical applications (Brain surgery without error and operations which require great skill etc.). This is only one of the implementations of haptic devices in digital environment. Aim of this project is to design and manufacture a novel haptic device which serves the mentioned application areas and to improve an interface to implement the device. Most of the haptic devices in literature have maximum 6 DOF. The 7 DOF haptic device designed has about 20% extra working space and more flexible working capability compared to the other haptic devices with the similar link lengths and joint limitations. This project is important in terms of the development of haptic devices in the world as well as spreading of haptic devices and its applications in Turkey

Classification of the Mediterranean lowland to submontane pine forest vegetation

Vegetation SurveyAim: Vegetation types of Mediterranean thermophilous pine forests dominated by Pinus brutia, Pinus halepensis, Pinus pinaster and Pinus pinea were studied in various areas. However, a comprehensive formal vegetation classification of these forests based on a detailed data analysis has never been developed. Our aim is to provide the first broad-scale classification of these pine forests based on a large data set of vegetation plots. Location: Southern Europe, North Africa, Levant, Anatolia, Crimea and the Caucasus. Methods: We prepared a data set of European and Mediterranean pine forest vegetation plots. We selected 7,277 plots dominated by the cold-sensitive Mediterranean pine species Pinus brutia, Pinus halepensis, Pinus pinaster and Pinus pinea. We classified these plots using TWINSPAN, interpreted the ecologically and biogeographically homogeneous TWINSPAN clusters as alliances, and developed an expert system for automatic vegetation classification at the class, order and alliance levels. Results: We described Pinetea halepensis as a new class for the Mediterranean lowland to submontane pine forests, included in the existing Pinetalia halepensis order, and distinguished 12 alliances of native thermophilous pine forests, including four newly described and three informal groups merging supposedly native stands and old-established plantations. The main gradients in species composition reflect elevational vegetation belts and the west–east, and partly north–south, biogeographical differences. Both temperature and precipitation seasonality co-vary with these gradients. Conclusions: We provide the first formal classification at the order and alliance levels for all the Mediterranean thermophilous pine forests based on vegetation-plot data. This classification includes traditional syntaxa, which have been critically revised, and a new class and four new alliances. We also outline a methodological workflow that might be useful for other vegetation classification syntheses. The expert system, which is jointly based on pine dominance and species composition, is a tool for applying this classification in research and nature conservation survey, monitoring and managementinfo:eu-repo/semantics/publishedVersio