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  • Article
    Citation - WoS: 6
    A Light Bulb in Every House the Istanbul General Electric Factory and American Technology Transfer To Turkey
    (Johns Hopkins Univ Press, 2022) Tunc, Tanfer Emin; Tunc, Gokhan
    In 1946, Turkish entrepreneur Vehbi Koc signed an agreement with the U.S. firm General Electric to build and operate its first light bulb factory in the Near/Middle East, in Istanbul. This private joint venture introduced new manufacturing techniques, business practices, and consumer habits to Turkey, opening channels of postwar technological exchange. Closer examination of the GE-Koc partnership reveals that during the early Cold War, the transfer and embedding of American technologies in Turkey was a politically complicated process of innovation that required constant adaptation. Fraught with unforeseeable obstacles, it also required cautious negotiation with multiple transnational actors. The story of the GE-Koc partnership thus adds a new dimension to historical understandings of the Turkish Cold War experience and the Americanization of the region. It illustrates how transferring a nonmilitary, soft-power, domestic technologythe light bulb-played a significant role in Turkish-American relations and therefore contributes to studies of U.S. Cold War diplomacy through transnational investment in innovation.
  • Article
    DOĞRUSAL OLMAYAN SINIR KOŞULLARINA SAHİP ISI TRANSFERİ PROBLEMLERİNİN SINIR ELEMAN YÖNTEMİ İLE ANALİZİNE YÖNELİK YENİ BİR FORMÜLASYON
    (2019) Baranoğlu, Besim
    Bu çalışmada Fourier denklemi ile ifade edilen ısı transferi problemlerinin bir ya da daha fazla bölgesinde tanımlı doğrusal olmayan sınır koşulları altında çözümüne yönelik sınır eleman yöntemi tabanlı etkili bir sayısal çözüm sunulmaktadır. Çözüm, sınır eleman yöntemi sistem matrislerinin üzerinde yapılan matematiksel işlemler ile bilinmeyenleri sadece doğrusal olmayan sınır bölgesindeki sıcaklık farkı olan indirgenmiş matris denklemleri elde etmektedir. Bu sayede doğrusal olmayan sınır koşullarına dayalı iterasyonlar daha hızlı gerçekleştirilebilmektedir. Doğrusal olmayan sınır koşullarının tanımlı olduğu bölgelerde çözüm elde edildikten sonra tüm sınır çözümü tanımlı bir son-işlem ile gerçekleştirilebilmektedir. Gerçek çözümü elde edilmiş bir örnek kullanılarak elde edilen sonuçlar değerlendirilmiştir.
  • Article
    Alzheimer hastalığında Kallikrein-6, 7 ve potasyum kanal proteinlerinin olası rolü
    (2021) Bulduk, Erkut; Yıldırım, Filiz; Yıldırım, Zuhal
    Amaç: Alzheimer hastalığının (AH) oluşum mekanizması kesin olarak bilinmemekle birlikte AH’dan sorumlu başlıca iki protein, senile plakların yapısındaki beta amiloid ve nörofibriler yumakların yapısındaki tau proteinidir. Hastalığa yol açan en önemli etmenlerden biri çözünür olmayan amiloid çökeltilerin oluşumu, diğeri ise artmış tau fosforillenmesidir. Kallikreinler, nöronal hasar ve işlev kaybı ile belirgin AH’nın etiyolojisinde rol oynayan, serin proteazların bir alt familyasıdır. Kallikrein (KLK)-6 ve KLK-7’nin merkezi sinir sisteminde (MSS) yüksek seviyelerde bulunan yaşa bağlı proteaz olduğu bilinmektedir. Daha once AH’ı gibi nörodejeneratif hastalıklarda yer alan hücre dışı proteinlerin proteolizine karıştığı gösterilmiştir. Bu çalışmada KLK-6 ve KLK-7’nin AH patogenezindeki olası rolünü ve potasyum kanal proteinleri arasındaki ilişkiyi araştırmayı amaçladık. Yöntem: Çalışmaya Polatlı Duatepe Devlet Hastanesinde takip edilen yaşları 65’in üzerinde olan 35 AH ve rutin tarama amacıyla nöroloji polikliniğine başvuran kognitif durumu normal olarak değerlendirilen 35 sağlıklı birey (control grubu) dahil edildi. 12 saat açlığı takiben antekübital venden alınan kan örnekleri 4°C’de 2500xg’de 10 dakika santrifüj edilerek, serum örneklerinde KLK-6 ve KLK-7 ile içeri doğru düzeltici potasyum kanalı (KCNJ3) ve iki gözenekli potasyum kanalı (KCNK9) protein düzeyleri enzim-bağımlı immunosorbent assay (ELISA) ile ölçüldü. Gruplar arasındaki fark T-test ile incelendi. p<0.05 istatistiksel olarak anlamlı kabul edildi. Bulgular: Gruplar arasında yaş ve cinsiyet açısından bir fark saptanmadı (p>0.05). Alzheimer grubu control grubu ile karşılaştırıldığında serum KLK-6 ve KLK-7 düzeyleri anlamlı olarak artarken (p<0.05), KCNJ3 ve KCNK9 protein düzeylerinde bir fark saptanmadı (p>0.05). Sonuç: Beyinde anormal protein katlanmasının ve birikmesinin önüne geçilememesinin AH’ye yol açtığı düşünülmektedir. Bu araştırmanın bulgularına göre KLK- 6 ve KLK-7 düzeyleri ile AH’nın patolojisi arasında bir ilişki saptandı.
  • Conference Object
    Citation - Scopus: 6
    The Use of Semi-Public Spaces as Urban Space and Evaluation in Terms of Urban Space Quality
    (Springer Nature, 2022) Orhan,M.
    The rapid physical change and increase in density of today’s cities lead to changes in urban space usage and habits in urban life. This change negatively affects the description and use of public spaces as socialisation spaces, which are one of the most significant urban components. As a result, city dwellers satisfy their need for public spaces with the use of different urban spaces. Urban life shifts from urban public spaces to semi-public spaces. Semi-public spaces are qualified and accessible spaces that ensure transition between private spaces (buildings) and public spaces. These spaces gain different attributes according to the characteristics (commerce, housing, tourism, etc.) of the urban spaces they coexist within and to the functions and designs of the structures surrounding them. These attributes determine their configuration as integrated or dissociated with the city and thus specify their relationship with the city. This relationship changes ‘city–space–structure–human’ interaction, and this change affects urban quality with the spatial quality of semi-public spaces. The aim of this study is to present how and related to which characteristics the use of semi-public spaces as urban spaces has changed, to detect the effects of this change on the urban environment and to establish the role of semi-public spaces in terms of urban quality. In conclusion, semi-public spaces with different characteristics located in different urban spaces will be examined as regards physical, schematic, functional characteristics and use within the scope of this study. In accordance with the data obtained by comparative analysis method, approaches to facilitate their use as urban spaces and to ensure their integration with the city will be introduced. Accordingly, criteria that semi-public spaces should possess in order to increase and sustain urban space quality will be determined. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Covid-19 Infection in Peritoneal Dialysis Patients: \ra Comparative Outcome Study With Patients on \rhemodialysis and Patients Without Kidney Disease
    (Aves, 2022) Kazancıoğlu, Rümeyza; Ozturk, Savas; Turgutalp, Kenan; Gürsu, Meltem; Arıcı, Mustafa; Oruç, Ayşegül; Ateş, Kenan
    Objectives: There is limited data about coronavirus disease-19 (COVID-19) characteristics and results in peritoneal dialysis \r(PD) patients. This study aimed to investigate the characteristics and outcomes among PD patients and compare them with \rmatched hemodialysis (HD) patients and a control group without kidney disease.\rMethods: We included 18 PD patients and consecutive age- and gender-matched 18 HD and 18 patients without kidney \rdisease (control group) registered into the Turkish Society of Nephrology database including 1301 COVID-19 patients. We \rcompared demographic, clinical, radiological, laboratory data, and outcomes namely intensive care unit (ICU) admission, \rmechanical ventilation, mortality, and composite outcome (death and/or ICU admission).\rResults: ICU admission, mechanical ventilation, and mortality rates in PD patients (27.8%, 22.2%, and 22.2%, respectively) \rand the HD group (16.7%, 11.1%, and 16.7%, respectively) were higher than the control group (11.1%, 11.1%, and 5.6%, \rrespectively), but intergroup comparison did not reveal difference. A total of 11 (20.3%) patients had composite outcome \r(6 PD patients, 3 HD patients, and 2 patients in the control group). In Cox regression analysis, higher age and higher CRP level were related to increased risk of composite outcome. Adjusted rate of composite outcome in PD group was significantly higher than \rthe control group (P = .050). This rate was similar in HD and control groups (P = .30).\rConclusions: Combined in-hospital mortality and/or ICU admission of PD patients with COVID-19 was significantly higher than the control \rpatients. There is a need for careful surveillance of PD patients for infection signs and prompt treatment of COVID-19.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 10
    Nöromüsküler Hastalarda Gövde Kontrolünün Değerlendirilmesi: Gövde Bozukluk Ölçeği’nin Geçerlik ve Güvenirliği
    (Turkish Neurological Soc, 2018) Demir, Yasemin Parlak; Yıldırım, Sibel Aksu
    Amaç: Çalışmamızın amacı Gövde Bozukluk Ölçeği’nin (GBÖ) erişkin nöromüsküler hastalıklarda geçerlik ve güvenirliğini araştırmaktır. Gereç ve Yöntem: Çalışmaya 66 nöromüsküler hastalık tanısı olan birey alındı. Çalışmaya dahil edilen olgulara GBÖ, Manuel Kas Testi (gövde, üst ve alt ekstremite), Motor Fonksiyon Değerlendirme Ölçeği (MFM), Fonksiyonel Bağımsızlık Ölçeği (FIM), Rivermead Mobilite İndeksi (RMI) yapıldı. Bulgular: GBÖ’nün test tekrar test, ICC güvenirlikleri mükemmel bulundu (GBÖ: 0,96 ve 0,98). Cronbach alfa katsayısı 0,82 bulundu. Yapı geçerliği için GBÖ ile MFM (r=0,29), MFM gövde (r=0,31), toplam gövde kas kuvveti (r=0,34), toplam alt ekstremite kas kuvveti (r=0,34, p<0,05), toplam kas kuvveti (gövde, alt ve üst ekstremite) (r=0,52, p<0,05) arasında anlamlı ilişki bulundu. GBÖ uyum geçerliği için FIM (r=0,32, p<0,05) ve RMI (r=0,39, p<0,05) ile ilişkili bulundu. Sonuç: Çalışmanın sonucunda GBÖ’nün erişkin kas hastalıklarında yapı ve uyum geçerliliğinin olduğu ve mükemmel güvenirliğe sahip olduğu bulundu. GBÖ rehabilitasyon kliniklerinde uygulaması kolay ve kısa zaman alan bir ölçektir
  • Article
    Citation - WoS: 7
    Citation - Scopus: 6
    Different Approach To Forming Sustainable Cities: Cittaslow
    (Scibulcom Ltd, 2017) Orhan, M.; Architecture
    Today, many cities can not adapt to 'urban deformation' escalated by globalisation and to the changes that develop accordingly. 'Fast' evolving lifestyles of the people bring a new identity and structure to cities. In the meantime, these lifestyles also deteriorate basic structural identities quite rapidly. While global processes force the whole world to follow a fast lifestyle, they also affect local lives and give rise to the rapid disappearance of urban differences and authenticities. 'Areas of poor quality with no identity and distinct characteristic features' have thus become the biggest problem of cities. Various urban approaches have started to be shown to solve these problems. One of these approaches is 'sustainable cities' that has emerged for a better environment and social life for the communities. Within the scope of this study, 'Cittaslow' is addressed as a different approach to building sustainable cities. Within this context, by ensuring the notion of 'Cittaslow' is clearly understood, urban parameters suggested by 'Cittaslow' within the framework of sustainability as a solution to modern-day urban problems have been determined. This urban movement, which strives for the protection of authenticity against the impact of globalisation, resists and scrutinises fast lifestyle and its effects on cities and the quality of urban life.
  • Article
    Citation - WoS: 8
    Effect of H2o Ratio on Photocatalytic Activity of Sol-Gel Tio2 Powder
    (Ice Publishing, 2013) Agartan, Lutfi; Kapusuz, Derya; Park, Jongee; Ozturk, Abdullah
    Effect of water/tetraethyl orthotitanate molar ratio (R) on the formation and morphology of sol-gel-derived titania powder has been studied. Solutions for R of 3 and 5 have been prepared. Initial viscosity of the solutions and viscosity of the gels prepared by aging the solutions for some time were measured. Results revealed that lower gel viscosities lead to better crystallization of the aerogel. Aerogels were dried at 80 degrees C for 24 h and then calcined at 300 degrees C for 1 h to obtain titania powders. The structural and morphological analyses of the powders were performed using X-ray diffraction and scanning electron microscopic characterization techniques. Titania particles obtained after calcination composed of only anatase phase and were in the size range of 9-50 nm. The photocatalytic activity of the powders was evaluated in terms of the degradation of methylene blue (MB) solution under UV (ultraviolet) illumination. A diffuse reflectance spectroscopy was used for the band gap energy measurements. Results revealed that R had a profound effect on the particle morphology and photocatalytic activity of sol-gel-derived titania powders. The titania powders prepared from the solution for R of 5 degraded 99.47% of MB solution under UV illumination in 90 min.
  • Article
    Citation - WoS: 3
    On Ciric Type φ-Geraghty Contractions
    (Chiang Mai Univ, Fac Science, 2019) Alqahtani, Badr; Fulga, Andreea; Karapinar, Erdal
    In this paper we introduce the notions of phi-Geraghty contractions and Ciric type phi-Geraghty contractions. We also investigate under which conditions such mappings posses a unique fixed point in the framework of complete metric spaces. We consider examples to show the validity of our main results.
  • Review
    Citation - Scopus: 7
    Ion Exchange Membranes for Reverse Electrodialysis (red) Applications - Recent Developments
    (Amirkabir University of Technology - Membrane Processes Research Laboratory, 2021) Eti,M.; Othman,N.H.; Guler,E.; Kabay,N.
    The innovative membrane-based technology called reverse electrodialysis (RED) is capable of producing electrical power from the controlled mixing of two aqueous streams of different salinity. There has been tremendous progress so far in the development of RED process in terms of system development, spacer design, membranes properties and operational conditions optimization. Among those, characteristics of the ion exchange membranes are found to be the critical element affecting the performances of RED process. In this respect, a brief overview of the latest developments in ion exchange membranes were presented in this review, focussing on their properties and performances in RED applications. The recent developments of nanocomposite and ion selective membranes, particularly pore filling ion exchange membranes due to their high performances and inexpensive fabrication cost were also summarized. Shortly, fouling problem for the ion exchange membranes employed in the RED system was mentioned. © 2021 Amirkabir University of Technology - Membrane Processes Research Laboratory. All rights reserved.