Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article A Discrete Element Method for Evaluating the Seismic Performance of Concrete Gravity Dam-Reservoir Systems Under Main Shock-Aftershock Events(Tulpar Academic Publishing, 2025) Soysal, B.F.Dams are crucial for water supply, flood prevention, and hydroelectric power generation. Often located in seismically active regions, they are vulnerable to main shock-aftershock (MS-AS) sequences, which can compromise structural integrity and hydraulic safety. Critical aspects of dam response to MS–AS events remain unclear, particularly the required rest time between successive events and threshold AS-to-MS intensity measure ratios that could serve as predictors of additional damage. This study addresses these gaps by analyzing concrete gravity dam–reservoir systems of three heights (50 m, 100 m, and 150 m) using the developed discrete element–based approach coupled with displacement/pressure-based mixed finite elements for the reservoir. Empirical rest time equations were derived from 124 as-recorded ground motions, while seismic performance under varying intensity levels was evaluated using 14 as-recorded MS–AS sequences. Damage was quantified using discrete indices of base crack length, maximum base crack width, and maximum total upstream crack width. Results indicate that AS primarily propagate existing cracks at lower intensities, whereas higher intensities generate new cracks along the upstream face, increasing crack widths by 25–30% on average. The 50 m high dam remained within the mild damage category, while taller dams occasionally reached moderate levels, posing potential seepage risks. Threshold AS-to-MS ratios for four different intensity measures were identified. These findings provide mechanistic insight into crack propagation under MS-AS events, providing practical guidance for post-earthquake dam safety assessment, inspection prioritization, and incorporating sequential seismic effects into design and emergency planning. © 2025 by the Author.Article Designing an Off-Road Working Lamp With Leds(Istanbul Univ, Fac Engineering, 2011) Cil, Celal Zaim; Yakisir, Burcu; Girgin, Burcu YakışırIn this study a working lamp used on the off-road working machines and vehicles is designed by using the LED diodes instead of a halogen bulb. In the design, firstly a LED array is determined and a proper driver circuit that can provide the required optical power is designed, and the working lamp developed is tested under various conditions. The luminous output values of the designed LED working lamp are compared with those of a commercial working lamp, which uses a halogen bulb. It is evaluated that in automotive applications lamps using LEDs could be successfully utilized depending on the optical efficacy of the LED used, the designs of the LED driver and the reflector.Article Citation - Scopus: 4Profesyonel Türk Futbolcularında Travmanın Değerlendirilmesi(Tıp Araştırmaları Derneği, 2011) Yamaner, Faruk; Gümüş, Mustafa; Güler, Dursun; Güllü, Esin; Kartal, AlpaslanAmaç: Dünyada en popüler olan futboldaki yaralanma miktarının azaltılması ve yaralanmaların önlenmesi için oyun pozisyonuna göre yaralanmaların anatomik lokalizasyonu ve yaralanma şekillerinin değerlendirilmesi önemlidir. Bu çalışmanın amacı, Türkiye Birinci ve İkinci Profesyonel Futbol Liglerine devam eden takımlarda oynayan futbolcularında yaralanmaların anatomik lokalizasyonu ve yaralanma şekillerinin değerlendirilmesiydi. Metod: Futbol yaralanmaları 510 futbolcunun katılımıyla ve anket yöntemiyle yapıldı. Bulgular: Farklı oyun pozisyonları için, yıpranmalar %64.5-85.4, kas zorlanmaları %52.-64.5, eklem burkulmaları %19.5-49.3 ve kırıklar %2.5-6.3 idi. Oyun pozisyonuna bakmaksızın alt eksremite yaralanmaları en genel yaralanmalar olarak saptandı (%60.5). Sonuç: Uygun ve yerinde alınan önlemlerle birlikte yaralanma riski ve miktarlarının azaltılması için bu bilgilerden yararlanılması önerilirArticle Citation - WoS: 1Citation - Scopus: 1Scattering of Plane-Waves by an Impedance Half-Plane at the Interface Between Isorefractive Media(Taylor and Francis Ltd., 2018) Basdemir, Husnu DenizThe scattering of plane waves by an impedance half-plane located at the interface of two isorefractive media is investigated. The scattered field, in addition to the diffracted and geometrical optics fields, is analyzed numerically and compared to the scattered field of perfectly conducting half-plane. The effect of the isorefractive media on the scattered field is also examined. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.