Atılım Academic Archive (Atılım University)
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Identification of Shallow Trap Centers in Inse Single Crystals and Investigation of Their Distribution: a Thermally Stimulated Current Spectroscopy
No full textIsik, Mehmet/0000-0003-2119-8266Identification of trap centers in semiconductors takes great importance for improving the performance of electronic and optoelectronic devices. In the present study, we employed the thermally stimulated current (TSC) method within a temperature range of 10-280 K to explore trap centers in InSe crystal-a material with promising applications in next-generation devices. Our findings revealed the existence of two distinct hole trap centers within the InSe crystal lattice located at 0.06 and 0.14 eV. Through the leveraging the T-stop method, we offered trap distribution parameters of revealed centers. The results obtained from the experimental methodology employed to investigate the distribution of trap centers indicated that one of the peaks extended between 0.06 and 0.13 eV, while the other spanned from 0.14 to 0.31 eV. Notably, our research uncovers a remarkable variation in trap density, spanning one order of magnitude, for every 10 and 88 meV of energy variation. The results of our research present the characteristics of shallow trap centers in InSe, providing important information for the design and optimization of InSe-based optoelectronic devices.Science Citation Index Expande
Complete Characterization of a Class of Permutation Trinomials in Characteristic Five
Get PDFIn this paper, we address an open problem posed by Bai and Xia in [2]. We study polynomials of the form f(x)=x4q+1+λ1x5q+λ2xq+4 over the finite field F5k, which are not quasi-multiplicative equivalent to any of the known permutation polynomials in the literature. We find necessary and sufficient conditions on λ1,λ2∈F5k so that f(x) is a permutation monomial, binomial, or trinomial of F52k. © The Author(s) 2024.TÜİTAK; European Commission, EC; Fundacja na rzecz Nauki Polskiej, FNP; Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTA
The US Role in the Rise of China: From Partnership to Threat
No full textAmerika Birleşik Devletleri ve Çin Halk Cumhuriyeti ilişkileri resmi olarak 1972 yılında başlamıştır. Gelişen ikili ilişkiler sonucunda uluslararası arenada tarihi şekillendirecek birçok farklı hipotezi de içinde barındırmaktadır. ÇHC'nin kurulmasıyla beraber ülkenin büyüyen ekonomisi, küresel bir güç olan ABD için bir tehdit unsuruydu. ABD'nin Asya bölgesi üzerine artan ilgisi ÇHC ile kimi zaman iyi ilişkilerin gelişimi için adımlar atılsa da, neticede krizleri de beraberinde getirmiştir. İki farklı ideolojik yapıya sahip ÇHC ve ABD 1972 yılından itibaren yapılan diplomatik adımlar, ekonomik işbirlikleri ve ticaretle günümüzün süper güçleri konumuna gelebilmişlerdir. Bu araştırmanın asıl amacı ise, Çin'in Amerika için neden ve nasıl bir tehdit haline geldiğidir. Çalışmanın birinci bölümünde, 1972-1990 arası yaşanan diplomatik ilişkiler, askeri destek ve ekonomik ilişkilerden oluşmaktadır. İkinci bölüm ise,1990-2010 arası Asya-Pasifik dönemini (Obama Asia Pivot politikaları). Üçüncü bölüm ise, 2010'dan günümüze kadar olan ABD'nin Asya politikalarından bahsedilirken ABD'nin liderlerinin kararlarının dış politikada Asya için nasıl şekillendiğini anlatan ana bölümden oluşmaktadır.As one of the important powers of the 21st century, the PRC has become a rising actor in the global system with its increasing political, military, and economic power. The United States played a major role in the rise of the PRC as of 1972. Having gained international recognition with US support, the PRC later integrated into the free market economy with US incentives. However, the PRC's rapid rise has deeply affected its relations with the United States, shifting them from cooperation to strategic competition. The authoritarian structure of the PRC, which has a structure that is very different from the American system based on democratic and liberal values, has reinforced the differences and distrust between the two countries.
The subject of the thesis is to analyze the political, military, and economic relations between the US and the PRC between 1970 and 2023, and how the bilateral relations transformed from a partnership to a perception of threat. While the normalization period began with the formalization of relations between 1970 and 1990, the years between 1990 and 2010 were years of acceleration in political, military, and economic relations. However, with the rise of the PRC in the post-2010 period, increasing competition with the US came to the fore. Political, military, and economic literature on US-PRC relations in both Turkish and English is quite limited. For this reason, the aim of the study is to contribute to the limited literature by examining in detail the political, military, and economic dynamics in US-PRC relations.
As a matter of fact, in order to better analyze US-PRC relations, it is important to examine them from a historical perspective. The argument of the study is that the process of progress from partnership to threat in US-PRC relations cannot be explained only by the historical background, therefore it is of great importance to analyze bilateral relations with political, military, and economic data. For this reason, the main sections of the thesis were divided into three periods between 1970-2023 and examined from a political, military, and economic perspective
Historical Environmental Kuznets Curve for the Usa and the Uk: Cyclical Environmental Kuznets Curve Evidence
No full textOmay, Tolga/0000-0003-0263-2258; Yildirim, Julide/0000-0002-4739-6028Human activities, including population growth, industrialization, and urbanization, have increasingly impacted the environment. Despite the benefits of economic growth to individual welfare, its negative environmental consequences necessitate a thorough assessment. The environmental Kuznets curve (EKC), positing an inverted U-shaped relationship between income per capita and environmental degradation, has been extensively studied since its proposition by Grossman and Krueger (Environmental impacts of a North American free trade agreement, National Bureau of Economic Research working paper, 1991. https://doi.org/10.3386/w3914). However, empirical evidence on the validity and shape of the EKC varies due to methodological differences, country-specific dynamics, and other factors. Examining the historical growth paths of individual countries helps explain the mixed findings in empirical EKC research. Long-term data allow researchers to determine the EKC's shape and turning points, aiding policymakers in devising appropriate environmental policies for each economic growth cycle within the framework of global environmental governance. Accordingly, this study contributes to the literature by taking a historical perspective on the EKC, focusing specifically on the United States and the United Kingdom. Drawing on data spanning from 1850, we employ advanced econometric techniques, including fractional frequency flexible Fourier form Dickey-Fuller-type unit root tests and structural breaks unit root tests, to overcome limitations of traditional linearized EKC estimations. Moreover, the classical polynomial regression approach is employed to model the long-term cycles based on the scatterplot inspection of per capita carbon dioxide (CO2) and per capita GNP series. Contrary to conventional expectations, our empirical findings do not support the existence of a clear inverted U-shaped EKC relationship between CO2 emissions and economic growth for either country. Instead, our analysis reveals the presence of multiple regimes, indicating a cyclical pattern where economic growth affects environmental quality with varying severity over time. Furthermore, we demonstrate proper modeling techniques for the EKC, highlighting the importance of identification and misspecification tests. Our study identifies cyclical EKC patterns for both the UK and the USA, with the UK exhibiting two cycles and the USA exhibiting three, shaped by varying economic, social, and technological contexts. By revealing the nuances of the economic growth-environmental degradation nexus for these early developer countries, our study provides valuable insights for policymakers seeking to devise evidence-based and environmentally sustainable growth policies within the framework of global environmental governance. These findings underscore the importance of considering historical context and structural changes when analyzing the EKC, providing valuable insights for policymakers aiming to design adaptive and sustainable economic growth strategies.Science Citation Index Expande
Hemoroid Lastik Band Ligasyonu Komplikasyonlarının Yönetimi: Masif Rektal Kanama
No full textAmaç: Çalışmanın amacı, hemoroidal hastalıkta cerrahi dışı tedavi seçeneklerinden biri olan lastik band ligasyonunu (RBL) ve buna bağlı gelişen komplikasyonları irdelemektir. Morbiditesi nedeniyle önem arz eden masif rektal kanama komplikasyonunun yönetimini sunmaktır. Gereç ve Yöntem: Evre 1-2 ve 3 internal hemoroidal hastalık nedeniyle 2018-2022 yılları arasında kliniğimizde RBL yapılan 564 hasta retrospektif olarak irdelenmiştir. Gebelik durumu, geçirilmiş anorektal cerrahi, kronik karaciğer hastalığı ve antikoagülan kullanımı nedeniyle 72 hasta çalışma dışında bırakılmıştır. Hastaların 492’si çalışmaya dahil edilmiştir. Tüm hastalara proktoloji ünitesinde detaylı anorektal muayene, 50 yaş üstündekilere ise kolonoskopik değerlendirme yapılmıştır. Hastaların demografik özellikleri, gelişen komplikasyonlar (minör/majör) ve uygulanan band ligasyon sayısı standardize edilmiş formlara kayıt edildi. Bulgular: Hastaların ortalama yaşı 33,4±11 (18-65) yıl olup, 385’i (%78,3) erkek, 107’si (%21,7) kadındı. Hastaların 39’una (%8) tek kadran, 448 hastaya (%91) iki kadran ve 5 hastaya üç kadran RBL uygulandı. RBL sonrası minör komplikasyonlar (anal ağrı, vazovagal semptomlar, minör rektal kanama, üriner retansiyon) yirmi hastada (%4) gelişirken, hastaların 4’ünde (%0,8) masif rektal kanama meydana gelmiştir. Masif rektal kanama gelişen hastaların hepsi acil şartlarda hospitalize edildi ve operasyona alındı. Bu hastaların birine 3 ünite, üç hastaya ise 4 ünite eritrosit transfüzyonu yapıldı. Sonuç: Hemoroidal band ligasyonu, hemoroidal hastalık tedavisinde güvenli ve etkili bir yöntemdir. Ancak hayatı tehdit edecek ciddi kanamalara yol açabileceği göz önünde bulundurulmalıdır
The Socio-Economic Impact of the Covid-19 Pandemic on Syrian Refugees in Turkey
No full textMemisoglu, Fulya/0000-0001-8113-813XKILINC, TUNA/0000-0001-8736-7750; MEMISOGLU, FULYA/0000-0001-8113-813XMEMISOGLU, FULYA/0000-0001-8113-813X; KILINC, TUNA/0000-0001-8736-7750Building upon empirical research, this study examines the socio-economic impact of the Covid-19 pandemic on Syrian refugees in Turkey by analyzing its implications on employment, livelihood opportunities, and social cohesion. More specifically, it focuses on the experiences of Syrian refugees to examine the ways in which they exert their agency to cope with the structural constraints when faced with 'multiple crises' in host countries, intersecting with the dynamics of a 'normalized refugee crisis'. Our findings from fieldwork conducted in the top six refugee-hosting cities reveal that loss of jobs, limited access to decent work, increased dependency on external financial assistance, and social exclusion have been some of the most acute effects of the pandemic on refugees. Meanwhile, the perceived effects that refugees have on the host community's welfare trigger problems that impede social cohesion. All in all, the study intends to highlight the far-reaching effects of the pandemic beyond its direct health implications by addressing the structural vulnerability of refugees and the importance of providing an enabling environment for socio-economic self-reliance.Japan International Cooperation Agency (JICA)The authors would like to thank Japan International Cooperation Agency (JICA) for funding the research project "Survey for Syrian refugees under Covid-19 Pandemic" on which this paper is based.Acknowledgement The authors would like to thank Japan International Cooperation Agency (JICA) for funding the research project "Survey for Syrian refugees under Covid-19 Pandemic" on which this paper is based.Acknowledgement The authors would like to thank Japan International Cooperation Agency (JICA) for funding the research project "Survey for Syrian refugees under Covid-19 Pandemic" on which this paper is based.Social Science Citation Inde
Aptamer decorated PDA@magnetic silica microparticles for bacteria purification
No full textKavruk, Murat/0000-0001-5331-7253; Dursun, Ali Dogan/0000-0001-9056-0025; KIBAR, Gunes/0000-0002-2586-6770One significant constraint in the advancement of biosensors is the signal-to-noise ratio, which is adversely affected by the presence of interfering factors such as blood in the sample matrix. In the present investigation, a specific aptamer binding was chosen for its affinity, while exhibiting no binding affinity towards non-target bacterial cells. This selective binding property was leveraged to facilitate the production of magnetic microparticles decorated with aptamers. A novel assay was developed to effectively isolate S. pneumoniae from PBS or directly from blood samples using an aptamer with an affinity constant of 72.8 nM. The capture experiments demonstrated efficiencies up to 87% and 66% are achievable for isolating spiked S. pneumoniae in 1 mL PBS and blood samples, respectively.Trkiye Bilimsel ve Teknolojik Arascedil;timath;rma KurumuNo Statement Availabl
İnsansız Hava Araçları (İHA) Mürettebat Performansı ve Emniyetin Artırılması: Teknoloji ve İnovasyon Yönetimi Perspektifi
No full textİnsansız hava araçlarının (İHA) çeşitli sektörlere entegrasyonu, operasyonel verimliliği, emniyeti ve görev başarısını sağlamak için insan faktörlerinin optimize edilmesinin önemini vurgulamaktadır. Bu çalışma, İHA operasyonlarında insan faktörleri üzerine yapılan literatürün kapsamlı bir bibliyometrik analizini sunmakta ve bilişsel iş yükü, durumsal farkındalık, karar verme, ergonomik tasarım ve insan-makine etkileşimi konularına odaklanmaktadır. Analiz, 2000-2023 yılları arasındaki yayınları kapsayacak şekilde Web of Science kullanılarak gerçekleştirilmiştir. Ana bulgular arasında, son on yılda araştırma çıktılarında önemli bir artış olduğu, İHA teknolojisi ve insan faktörlerine olan artan ilgi ve yatırımı vurgulayan sonuçlar yer almaktadır. Rosenstein (2006), Patterson (2010), Reason (1990), Wiegmann (2001) ve Shappell (2007) gibi etkili yazarlar ile Beijing University of Posts and Telecommunications, Southeast University China, Xidian University, ve Nanjing University of Aeronautics and Astronautics gibi kurumlar, bu alanda lider olarak ortaya çıkmış ve ergonomik tasarım ve karar verme süreçlerinde ilerlemelere katkıda bulunmuşlardır. Özellikle, İHA operatörlerinin uzun vadeli bilişsel iş yükü etkilerini ele alan kapsamlı çalışmaların ve İHA operasyon ortamlarına özel olarak uyarlanmış standart ergonomik kılavuzların geliştirilmesinin eksikliği dikkat çekicidir. Gelişmiş insan-makine etkileşimi teknolojilerinin entegrasyonu halen yeterince araştırılmamış olup, bu alanda daha fazla araştırmaya ihtiyaç olduğunu göstermektedir. Bu boşlukları vurgulayan analiz, mevcut araştırma dinamiklerini anlayışlı bir şekilde sunarak İHA operatörleri, düzenleyiciler ve politika yapıcılar için değerli çıkarımlar sağlamaktadır. Bu bulgular, alanın ilerlemesi ve İHA operasyonlarında ekip performansı ve güvenliği artırmaya yönelik gelecekteki araştırma girişimlerine rehberlik etmek açısından önemlidir
Multi-Axial Ultrasonic Vibration-Assisted Machining of Inconel 718 Using Al2O3-CuO Hybrid Nanofluid MQL
No full textLotfi, Bahram/0000-0002-3027-3734;Inconel 718 is a widely used superalloy in the aerospace industry, owing to its exceptional creep and corrosion resistance, as well as its ability to retain strength at elevated temperatures. However, its machinability presents challenges due to its low thermal conductivity and high work hardening rate during conventional machining, resulting in inadequate surface quality. To address this issue, a recent technique known as Ultrasonic Vibration-Assisted Machining (UVAM) has emerged. UVAM involves applying high-frequency, low-amplitude vibrations to the cutting tool or workpiece. Additionally, Minimum Quantity Lubrication (MQL) has been considered as an alternative cooling technique to enhance machining performance. Optimizing the performance of UVAM can be achieved by employing various vibration axes. Additionally, the effectiveness of MQL can be enhanced through the utilization of nanofluids. This study investigates the combined application of multi-axis UVAM and Al2O3-CuO added Hybrid Nanofluid MQL (HNMQL) during the milling of Inconel 718. The evaluation parameters include surface roughness, topography, burr formations, and cutting forces. The results demonstrate that the simultaneous use of multi-axis UVAM and HNMQL significantly improves the machining performance of Inconel 718. This combination leads to better surface quality and overall process efficiency, offering promising prospects for the aerospace industry and other applications involving difficult-to-cut materials. (c) 2024 The Authors. Published by Elsevier B.V.Scientific and Technological Research Council of Turkey (TUBITAK) [222M381]This research was funded by The Scientific and Technological Research Council of Turkey (TUBITAK), grant number 222M381. The authors would like to express their gratitude to Belgin Oil Company for providing the MQL oil
SPACES AND PLACES OF MODERNITY AND THE MODERN ARTIST IN OĞUZ ATAY’S “RAILROAD STORYTELLERS - A DREAM”
No full textThis paper examines Atay’s “Railroad Storytellers - A Dream” in terms of Atay’s modernist experimentation in his depiction of space and spatiality, emphasising his contribution to Turkish literature as a pioneer modernist author. Oğuz Atay’s distinctive and innovative style, which forms his affinities with the early Western modernists such as James Joyce and Virginia Woolf, establishes his significant place as a pioneer modernist author in Turkish literature in the 1970s. The concept of ‘house/ home’ by Gaston Bachelard in The Poetics of Space (1957, 2014) is instrumental for me as it pertains to the predicament of three storytellers as artists in the nameless and remote railroad station. The narrator of the story and his fellow storytellers gradually sink into disconnection, confusion, misery and poverty in an environment that represents the cold and unwelcoming face of technological modernisation symbolised by the space of the train station. The narrator’s quest for finding a ‘home’ to connect him to his readers and where he could exist as an artist comes to life in his attempt to write a letter to his readers, telling them he is still ‘here’ and asking them where they are. No matter how blighted that effort is since the narrator has no address to send the letters to, the endings for Atay’s story imply a need for connection with his readers expressed in the impossible meeting of the ‘here’ with the ‘where’ in spite or because of the estrangement and alienation of the artist/author in the modern world. Hence, the possibility of space as a ‘home’ for the author/narrator dwindles in the not forthcoming answer to the letter that will never reach its destination. Copyright © 2024 N. Berrin Aksoy