Betonarme binaların deprem performanslarının deprem geçirmiş binalarla ilişkilendirilerek belirlenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Son yıllarda meydana gelen depremlerde oluşan hasarın ve ekonomik kayıpların çok büyük miktarda olması Deprem Mühendisliği'nde Performansa Dayalı Tasarım ve Değerlendirmenin önemini bir kez daha gözler önüne sermiştir.Bu çalışmada ?17 Ağustos 1999 depreminde meydana gelen yapısal hasarlar daha önceden belirlenebilir miydi?? sorusunun cevabı aranmıştır. Bu amaçla 17 Ağustos 1999 Depremi'nde, farklı hasar durumundaki iki yapı sisteminin Doğrusal Elastik Olmayan Hesap Yöntemi ?Eşdeğer Deprem Yükü Yöntemi? ile performans değerlendirmesi yapılmıştır. Sonuçların gerçekle uyumu irdelenmiştir.Yapılan çalışmalar sonucunda depremde hasar almayan yapı sisteminin performansı gerçekle uyum sağlamıştır. Ancak depremde göçmüş olan yapı sisteminin performansı, gerçek durumundan daha iyi düzeyde çıkmıştır. Çalışma, depremde farklı performans gösteren çok sayıda binalarla genişletildiği takdirde, Yönetmeliğe yeni giren yöntemlerin kalibre edilmesinde önemli rol oynayacaktır.Anahtar kelimeler: Doğrusal Elastik Olmayan Yöntem, Artımsal Statik İtme Analizi, Artımsal Eşdeğer Deprem Yükü Yöntemi, Performans DeğerlendirmesiIn recent years, earthquakes which caused important damages and much economic lost, again have showed that performance based design and evaluation is very important in Earthquake Engineering.In this study, the answer of the question, ?Could the damageability of structures during the August 17th, 1999 Marmara Earthquake, be determined or estimated before earthquake using the Performance Based Design Methods.?? was investigated. To answer this question, two reinforced concrete structures, which prone to 17 August 1999 Marmara Earthquake and showed different performance levels are studied by using nonlinear static procedures. The calculated results were compared with the performance observed after the Earthquake.Result of this studies showed that, undamaged structure?s performance was the same with real performance level. But collapsed down structure?s performance level was better than real performance level. This study will have an important role in the comparison of new methods in Earthquake Regulation if it is amplified with different structures that are in different performance levels in earthquake.Key words: Nonlinear Elastic Method, Incremental Static Pushover Analysis, Incrimental Equivalent Earthquake Load Method, Performance Evaluatio

Cost Benefit Analysis Of The Structures Designed For Alternative Seismic Hazard Levels

In this study, multiple performance objectives under the various earthquake hazard levels are investigated. In case of well defined earthquake hazard, as an alternative of classical earthquake resistant design principles, it is possible to design structures at different performances depending on structure's initial cost and economic life. In this study, costs of the structure with different performance levels are discussed.Current study is carried out on the reinforced concrete structures that are designed and analyzed for various seismic hazard levels. The aim is to determine, if the risk is released, whether the economic losses can be acceptable or not. In the study, cost of reinforced concrete ductile frames and dual systems that are designed for various seismic performances, are also compared for the economical aspects.To that end, in the first step 3, 5 and 8 storey frames and dual systems of several structures at Life Safety and Immediate Occupancy performance levels was designed for the earthquake hazards of 2% and 10% probability of exceedance in 50 years. The study reveals that if both direct and indirect effects of earthquake such as retrofitting costs, cost of temporary moving, temporary accommodation costs, cost of demolition and reconstructing the building, cost of damage to household goods and business disruption, social disturbance, are be taken into consideration, initial design performance level can be accepted as Immediate Occupancy performance level rather than Life Safety performance which is proposed current earthquake codes. The cost due to injuries and cost due to loss of lives are not included

Alternative instrumentation schemes for the structural identification of the reinforced concrete field test structure by ambient vibration measurements

The outcomes of the ambient vibration measurements carried out to evaluate the dynamic characteristics of the reinforced concrete field test structure were presented. The test building was designed according to Turkish Seismic Code and constructed for this research study at the field laboratory in Sakarya University. The first aim is to conduct ambient vibration tests on a full-scale field test structure to measure its modal properties for the cross-validation of a finite element model of the test structure. The second aim is to optimize the instrumentation schemes from cost and quality of data point of view. Six tri-axial accelerometers were situated in different configurations on the test structure. For every configuration ambient vibrations were recorded to measure the dynamic characteristics of the test structure. For the system identification with ambient vibration signals Enhanced Frequency Domain Decomposition (EFDD) method was used. A satisfactory match between theoretical and experimental modal parameters was deduced for certain instrumentation scheme

Borç Çeşitliliği Firma Performansını Nasıl Etkiler?

Bu çalışmada, Borsa İstanbul’da işlem gören finansal olmayan şirketlerin 2010-2022 yıllık verilerine dayanarak, borç çeşitliliği ile finansal performans arasındaki ilişki genelleştirilmiş momentler yöntemi ile analiz edilmiştir. Literatürdeki çalışmaların çoğu firmaların borç yapılarının homojen olduğunu varsaymaktadır; ancak genel olarak firmalar farklı borç türlerini kullanarak borçlanırlar. Sermaye yapısının önemli bir finansal performans belirleyicisi olduğu ampirik çalışmalar ile kanıtlandığından, borç çeşitliliği ve finansal performans arasındaki ilişki araştırmaya değer bulunmuştur.Çalışmanın bağımlı değişkeni olan finansal performans, ROA ve Tobin's Q ile ölçülmüştür. Borç çeşitliliğine ek olarak, firma büyüklüğü, likidite, maddi duran varlık oranı, faiz karşılama gücü ve temettü politikası analize kontrol değişkenleri olarak dahil edilmiştir. Bu çalışmanın sonuçları, borç çeşitliliğinin hem ROA'yı hem de Tobin's Q'yu olumlu etkilediğini, ancak etkinin Tobin's Q'da daha yüksek olduğunu ortaya koymaktadır. Sonuçlar, piyasanın çeşitlendirilmiş borç yapısını birden fazla borç veren olması durumunda borçlunun daha etkin izlenmesi sebebiyle daha az vekalet sorunu ile ilişkilendirdiği sonucuna varılabilir.The manuscript analyzes the relation between debt heterogeneity and financial performance for non-financial Turkish listed firms from 2010 – 2022 by employing the generalized method of moments. The majority of the studies in the finance literature assume a homogeneous debt structure; however, firms generally raise debt in different forms. This issue deserves attention where capital structure is found to be a significant financial performance determinant.Financial performance, the dependent variable, is proxied by ROA and Tobin’s Q. In addition to debt heterogeneity, firm size, liquidity, tangibility, interest coverage, and dividend policy are included in the analysis as control variables. The empirical results of this study put forth that debt heterogeneity positively affects both ROA and Tobin’s Q; however, the effect is higher on Tobin’s Q. The results can be concluded that the market may associate diversified debt structures with lower agency conflict since different creditors perform more efficient monitoring.&nbsp;</p

Interfacial layer thickness dependent electrical characteristics of Au/(Zn-doped PVA)/

Au/(Zn-doped PVA)/n-4H-SiC metal/polymer/semiconductor (MPS) structures with different interfacial layer thickness values (50, 150, 500 nm) were fabricated and their electrical characteristics were compared. Their electrical parameters (i.e. reverse-bias saturation current (Io), ideality factor (n), zero-bias barrier height (BH) (Φbo), series and shunt resistances (Rs, Rsh)) were calculated from the forward bias current–voltage (IF–VF) data whereas other parameters (i.e. Fermi energy level (EF), BH (Фb) and donor concentration (Nd)) were calculated from the linear part of C−2–V characteristics at room temperature. Obtained results confirmed that the values of n, Φbo, Rs and Rsh increase with increasing interlayer thickness, and linear correlation between n and Φbo was observed. The high values of n for three structures can be ascribed to the presence of an interlayer, surface states (Nss) and barrier inhomogeneities. The energy density distribution profile of Nss was obtained from the IF–VF data by taking into account voltage-dependent effective BH (Фe) and n for each structure. The Ri vs V plot for these structures was obtained using both Ohm's law and Nicollian–Brews method. All these experimental results show that the interfacial layer and its thickness play an important role in main electric parameters of these structures

Determination of Aflatoxin Contents of Some Chips and Snacks with Peanut by Post-Column UV Derivatization System

International audienc

Effect of disinfection processes and anthropogenic pollutants on comparative formation of trihalomethanes and N-nitrosodimethylamine

Gurel, Melike/0000-0002-2130-2062; Orak, Nur H./0000-0002-3830-9260; Ates, Esra Genceli/0000-0003-3190-2202; Aydin, Egemen/0000-0003-3619-9712; Pehlivanoglu-Mantas, Elif/0000-0003-1335-365XWOS: 000475910400013Chloramination and chlorination contribute to the formation of N-nitrosodimethylamine and trihalomethanes, respectively, both of which are defined as disinfection by-products. To be able to select the most appropriate water treatment scheme, it is important to comparatively evaluate the formation of both of these disinfection by-products during the application of different disinfection methods. In this study, chlorination, chloramination and stepwise chloramination methods have been applied to surface water samples that have been spiked with known N-nitrosodimethylamine precursors. Experimental results showed that ranitidine can be an effective N-nitrosodimethylamine precursor in distilled water, when chloraminated with high concentrations (140mg/L) for a long time (10days), resulting in approximately 450ng/L of N-nitrosodimethylamine. However, neither dimethylamine nor ranitidine leads to significant trihalomethanes or N-nitrosodimethylamine formation in lake water when chloramination is conducted with low concentration (2mg/L) for 2h. These results suggest that N-nitrosodimethylamine concentration measured in the effluent of the drinking water treatment plant may underestimate the N-nitrosodimethylamine concentration that will reach the consumers since chloramination reactions will continue in the distribution system. On the other hand, when only N-nitrosodimethylamine formation potential is used, it will overestimate the N-nitrosodimethylamine that might form in the distribution system due to high disinfectant concentration, high contact time and adjusted pH values used in the N-nitrosodimethylamine formation potential test.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108Y311]; ITU Research Fund ProjectIstanbul Technical University [34981]This work was funded by the Scientific and Technological Research Council of Turkey (TUBITAK, Project # 108Y311) and ITU Research Fund Project # 34981