Yazarlar
- Tozlu, Alperen(13)
- Ergün, Mustafa(11)
- Artar, Musa(10)
- Cuce, Erdem(9)
- Cuce, Pinar Mert(8)
- Yurdakul, Muhammet(8)
- Imamoglu, Ilyas Kays(7)
- Esmer, Yusuf(6)
- Isik, Cem(6)
- Ongan, Serdar(6)
- Can, Ömer(5)
- Guclu, Tamer(5)
- Kahveci, Hakan(5)
- Tayfur, Bilal(5)
- Yilmaz, Fatih(5)
- Ates, Sevket(4)
- Guler, Evrim(4)
- Gökçe, H.S.(4)
- Karakus, Murat(4)
- Tapkın, Serkan(4)
- Tercan, Emre(4)
- Çaglar, Hakan(4)
- Özahi, Emrah(4)
- Abdioglu, Murat(3)
- Abusoglu, Aysegul(3)
- Altuntas, Serkan(3)
- Ateş, Şevket(3)
- Ayberkin, Doruk(3)
- Aydin, Rahman(3)
- Cakici, Ziya(3)
- Cakir, Mehmet(3)
- Carbas, Serdar(3)
- Dereli, Turkay(3)
- Engin, Mustafa Alptekin(3)
- Gökçe, H. Süleyman(3)
- Güngör, Okan(3)
- Kiral, Adnan(3)
- Kuziboev, Bekhzod(3)
- Murat, Yetis Sazi(3)
- Okur, Fatih Yesevi(3)
Yayınlar
- MakaleAçık Erişim2025Scopus SJRQ1Design and initial experimental verification of a high-speed electrodynamic levitation measurement system utilizing modular magnetic field sources and aluminium rails
Ozturk, U. Kemal; Mollahasanoglu, Hakki; Abdioglu, Murat; Okumus, Halil Ibrahim; Gedikli, Hasan
This work presents design and development of a modular high-speed electrodynamic levitation (EDL) test system that integrates advanced magnetic field configurations and real-time control capabilities at high operational speeds. The system comprises a rotating aluminium rail and interchangeable magnetic field sources, including permanent magnet array (PMA) and high-temperature superconducting (HTS) bulk, allowing for a variety of experimental configurations. The initial experimental results focused on testing the system through PMA–aluminium rail and HTS–aluminium rail configurations. A key innovation of this system is its modular structure, which allows for easy replacement and reconfiguration of magnetic components and rail geometries. The adaptability of the system enables a thorough investigation of how different magnetic field sources influence magnetic force and dynamic stability at high speeds. Furthermore, the system is fully integrated with a programmable logic controller (PLC) and supervisory control and data acquisition (SCADA) interface, enabling precise real-time monitoring, synchronized control and automatic data acquisition. Experimental results demonstrate the system's capability to measure vertical displacement variations and force fluctuations at different speeds, with resonance effects identified around 145 km/h. The levitation forces of 99 N were measured at a gap of 10 mm, with the PMA at a maximum speed of 283 km/h above an aluminium rail, while it was measured as 16 N with HTS at a vertical gap of 9 mm. This flexible test platform provides a critical foundation for determining the force parameters of the real-scale EDL Maglev technologies and advancing their practical application potential in high-speed transportation.
AtıfScopus3WoS3OpenAlex2
İncele - MakaleYalnız künye2025Scopus SJRQ1Optimized model updating and site-specific seismic assessment of a historical masonry bridge
Tayfur, Bilal
This study comprehensively evaluates an 800-year-old masonry bridge using advanced non-destructive testing techniques, an innovative model update process, and site-specific ground motion analysis. Employing Operational Modal Analysis, Ultrasonic Pulse Velocity, and Schmidt Hammer tests, the research meticulously characterized the structural dynamic properties. The preliminary finite element model was rigorously refined utilizing the Tabu Search optimization algorithm by minimizing discrepancies between numerical and experimental modal parameters. Site-specific earthquake records, carefully selected and prepared in accordance with the Turkish Building Earthquake Code, were applied to conduct detailed time-history analyses across 11 distinct ground motion records. Despite experiencing stresses approaching critical thresholds, the bridge demonstrated remarkable structural integrity. While the findings indicate the bridge’s structural soundness under current seismic hazard analysis criteria, the results notably emphasize that the frequency content similarities between the structure and ground motion are more critical for seismic performance assessment than peak ground acceleration (PGA) values, underscoring the importance of continuous monitoring given the region’s complex tectonic characteristics.
AtıfScopus5WoS3OpenAlex4İncele - MakaleAçık Erişim2025Scopus SJRQ2Advancing perovskite solar cells: Inorganic CCTS hole-transporting material for enhanced efficiency and stability
Sari, Fahriye; Ozel, Sultan Suleyman; Sarilmaz, Adem; Ozel, Faruk; Kus, Mahmut; Ersoz, Mustafa
One of the most effective methods for generating renewable energy is the efficient conversion of photons into electrical energy using environmentally sustainable materials. In recent years, the integration of chalcogenide materials, which exhibit graphene-like semiconducting properties and high charge carrier mobility, into perovskite solar cells (PSCs) has garnered significant attention for enhancing the performance, stability, and eco-friendly nature of these devices. In this study, Cu₂CoSnS₄ (CCTS) nanocrystals were synthesized and utilized as a fully inorganic hole transport layer (HTL) in inverted PSCs. Devices incorporating 6 vol% CCTS achieved a power conversion efficiency (PCE) of 10.07 %, and retained 93 % of their initial efficiency after 720 h under inert storage conditions, without encapsulation. This demonstrates a notable improvement in stability compared to conventional PEDOT: PSS-based devices. The optimized CCTS HTL provided better energy level alignment, reduced moisture ingress, and enhanced charge transport. These findings indicate that CCTS is a promising inorganic HTL candidate for efficient and stable PSCs.
AtıfScopus5WoS5OpenAlex4İncele - BildiriAçık Erişim2025Analysis of Lightning-Induced Electromagnetic Pulses on High Voltage Transmission Lines
Cakil, Turan; Ozen, Sukru; Ates, Kayhan; Cakir, Mehmet
in this study investigates grounding enhancement techniques for power transmission lines, drawing an analogy with electromagnetic shielding methods. If we look at the basic analogy between electromagnetic shielding and grounding, the purpose of shielding is to prevent electromagnetic fields (both electrical and magnetic) from reaching an area or to reduce electromagnetic propagation. Grounding helps maintain signal quality, eliminate static buildup, and ensure the system meets EMC (electromagnetic compatibility) requirements by safely conducting the shield's parasitic potential to the ground. Examples of such structures include single-point grounding or two-point grounding and the use of mesh. The fundamental principle here is to reduce or prevent the interference of parasitic signals into the protected system. The objective is to improve the reliability and efficiency of transmission systems by optimizing grounding performance. Lightning and electromagnetic pulse (LEMP) intensity and current amplitude data obtained from the Turkish State Meteorological Service (TSMS) were used in the analysis. The electrical performance of the line and its resistance to LEMP-induced faults were evaluated through simulations using the Alternative Transients Program - Electromagnetic Transients Program (ATP-EMTP). The Seydişehir-Akseki-Varsak transmission line was selected as a case study. Results show that grounding improvements led to a significant reduction in the number of LEMP-related outages. Guy wires (GWs) enhanced the electromagnetic coupling between phase conductors and improved the dissipation of LEMP currents into the ground, thereby reducing the equivalent ground resistance. Due to the high cost of line surge arresters, the use of low-cost and easily deployable alternatives such as GWs is recommended. Further analysis on 400 kV transmission lines revealed that GW implementation reduced the flashover voltage at insulator terminals by up to 49%. These findings highlight the importance of cost-effective grounding methods in establishing reliable and sustainable power transmission infrastructure.
- MakaleYalnız künye2025Scopus SJRQ3Numerical Investigation of EDS Maglev Systems in Terms of Performance and Cost for Different PMs-Aluminum Rail Arrangements
Mollahasanoglu, Hakki; Abdioglu, Murat; Ozturk, Ufuk Kemal; Okumus, Halil Ibrahim; Coskun, Elvan; Gencer, Ali
Permanent-magnet electro-dynamic suspension (PMs-EDS) maglev systems are shaping the future of modern transport by providing high-speed, energy-efficient, and sustainable transport solutions. In this study, numerical simulations were performed to determine the optimum geometrical parameters of aluminum rail and permanent magnet arrangements for EDS systems. For that, the aluminum rail and permanent magnet combinations were investigated, and then the same simulations were repeated by creating cavities in the aluminum rails for cost efficiency. The highest levitation-to-drag ratio (LDR) was achieved with magnet arrays having a fill factor of 0.4, 20 mm thick aluminum, and an aluminum rail width of 60 mm. Additionally, by creating cavities into the rails, it was calculated that approximately $2.44 million could be saved from the total cost of $17.34 million cost of the 1000 km double-strip aluminum rails, with negligible reduction in the LDR ratio. The findings of this study provide a sustainable and economical transport solution by increasing the cost effectiveness of PMs-EDS maglev systems. The results obtained may pave the way for the development of different types of applications of maglev technology and increase the potential for commercial use of maglev transport systems.
AtıfScopus4WoS5OpenAlex5İncele - MakaleYalnız künye2025Scopus SJRQ2Theoretical and experimental studies on a novel potential barrier control for a vehicle model and piezoelectric smart structure
Uyar, M.
A novel control methodology, inspired by the quantum mechanical phenomenon of particle-wave duality, wherein particles and waves utilize their energy to traverse potential barriers, has been proposed. This control strategy is investigated both numerically and experimentally to mitigate undesirable vibrations in a three-degree-of-freedom vehicle system and a smart beam structure. The mathematical framework for the vehicle system is derived using Lagrange’s equations, while the experimental setup is designed for the smart beam. Disturbance inputs in the form of step and sinusoidal road profiles are introduced into the vehicle model to simulate real-world conditions. For the smart beam, endpoint vibrations are induced as an initial value problem by releasing the beam’s endpoint from a predefined initial displacement. In order to achieve vibration suppression, control signals, parameterized based on system-specific frequency and period characteristics, are applied to both systems. The optimal control parameters are determined by evaluating the vibration damping performance. The findings of this study demonstrate that the proposed control strategy is not only effectively applicable to the experimental validation of the piezoelectric smart structure but also holds significant potential for numerical integration into mechanical systems, such as vehicle dynamics models.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Experimental performance assessment of two-stage thermoelectric system in a closed-cycle drying process
Osta, Muhammet Harun; Yakut, Kenan; Köksal, Hüseyin
Traditional drying systems suffer from several limitations, including high energy consumption, insufficient hygienic control, and the inability to maintain precise temperature regulation. Although alternative drying systems have been developed to address these issues, they often encounter practical challenges due to their complex structures and the need for numerous external components. To overcome these limitations, this study proposes and experimentally evaluates a novel, independently operating, two-stage thermoelectric module (TEM) system integrated into a closed-loop drying setup that eliminates the need for external heating and dehumidification components. The proposed system addresses the efficiency and hygiene problems observed in conventional dryers by simultaneously performing air heating, cooling, and dehumidification functions through compact thermoelectric devices. The drying process consists of two stages: the first involves air pre-conditioning (heating/cooling), while the second is dedicated to dehumidification. The performance of the system has been evaluated based on key metrics such as cooling and heating capacities, the coefficients of performance (COP) for both stages, moisture removal rate (MRR), and moisture removal rate effectiveness (EffMRR). Experimental studies were conducted under input voltages ranging from 3 to 7 V, relative humidity levels between 60 % and 90 %, and varying airflow rates. Under 90 % relative humidity conditions and a 7 V input voltage, the system achieved a maximum moisture removal rate of 13.1 g/h. The first-stage TEM reached a heating capacity of 68.81 W and a cooling capacity of 26.34 W, while the second stage provided 21.17 W of cooling capacity.
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ1The Role of Women's Entrepreneurship, Unemployment, Global Warming, and Technology in Sustainable Development: Evidence From OECD Countries
Isik, Cem; Ongan, Serdar; Günlü, Ebru; Aydin, Rahman; Imamoglu, Ilyas Kays
This study examines the effects of women's entrepreneurship, global warming, technological advancements, and unemployment on the achievement of the sustainable development goals (SDGs) across 38 OECD countries. Using country-specific panel causality methods, the analysis reveals significant asymmetries between developed and developing economies. Women's entrepreneurship (FEM) and technology (TEC) demonstrate stronger positive effects in developing countries such as Mexico, Slovakia, and Costa Rica, supporting SDGs 5 and 9. Global warming (SUR) negatively affects both groups, with notable impacts in Belgium, Mexico, and the UK, emphasizing the urgency of SDG 13. Unemployment (UNM) poses greater threats to sustainable development in emerging economies-particularly in Turkey and Latin American nations-while its influence remains limited in advanced countries. These results underscore the heterogeneous nature of SDG progress and suggest that universal, one-size-fits-all policies may fall short. Instead, national strategies should strengthen gender-inclusive entrepreneurship and innovation, while mitigating climate risks and labor market vulnerabilities. This paper presents a novel, multidimensional econometric framework and offers original insights into how interlinked economic, social, and environmental factors influence sustainability outcomes across diverse national contexts.
AtıfScopus23WoS18OpenAlex21İncele - MakaleAçık Erişim2024İnsansız Hava Araçları ile Orman Yangınlarının Tespitinde Görüntü İşleme ve Yapay Zekâ Tabanlı Otomatik Bir Model
Kökhan, Serhan; Engin, Mustafa Alptekin
Nefes almak için gereksinim duyduğumuz oksijenin büyük bir kısmı, hayatta kalabilmemiz için hayati öneme sahip olan ormanlar tarafından üretilir. Bu yüzden ormanları korumak, içinde yaşadığımız yüzyılın en önemli konu başlıklarından bir tanesidir. Dünyanın farklı coğrafyalarında (ABD, Avustralya vb.) her yıl meydana gelen orman yangınları ciddi ekonomik kayba neden olmakta ve ekosistemi olumsuz olarak etkilemektedir. Ateşin çeşitli renk, şekil ve doku özelliklerine sahip olması orman yangınlarının uzaktan algılanmasını zorlaştırmaktadır. Yapılan bu çalışmada orman yangınlarının tespitinde insansız hava araçları vasıtasıyla tamamen otomatik bir sistem önerilmiştir. Ormanlık arazinin tespitinde uydu görüntüleri üzerine görüntü bölütleme yöntemi kullanılmış, insansız hava aracının tespit edilen bölgeyi en kısa zamanda ve en az görüntü ile kontrol edebilmesi için de küme kaplama yöntemi kullanılmıştır. Daha sonra elde edilen imgeler üretilen yapay zekâya dayalı ateş algılama modeline göre değerlendirilip başlangıç ve ileri aşamadaki yangınlar tespit edilmiş ve konumları elde edilmiştir. Sonuç olarak, yapılan çalışmada yaklaşık %97,51 değerinde doğrulukla yangın tespit eden bir erken uyarı modeli önerilmektedir.
AtıfOpenAlex3
İncele - MakaleAçık Erişim2024L Tipi Matris ve Fine-Kinney Metodları Kullanılarak Erzurum Havalimanı’nın Çevresel Risk Değerlendirmesi
Kul, Sinan; İrdemez, Şahset; Ozdemir, Mustafa; Bedir, Ferdin
Dünya ekonomisinde önemli bir yeri olan havacılık sektörü diğer birçok sektör ile karşılaştırıldığında çok daha yüksek bir büyüme oranına sahiptir. Günümüzde küresel sera gazı emisyonlarının yaklaşık %2'sinin bu sektörden kaynaklandığı ve ilerleyen yıllarda bu emisyonların sektörün büyüme oranları ile paralel olarak artacağı düşünülerek gerekli tedbirlerin vakit kaybetmeden alınması yerinde olacaktır. Havalimanlarının inşaat faaliyetleri süresince ekosistem olumsuz olarak etkilenirken, havalimanı altyapılarının yüksek enerji ihtiyaçları, işletme aşamasında oluşan önemli miktarlardaki atık maddeler, havalimanı operasyonlarından kaynaklanan gürültü emisyonları vb. nedenler yerel halkın refahını önemli ölçüde etkileyebilmektedir. Havalimanlarında yürütülen uygulamaların çevreyi ve yerel halkı etkilediği göz önünde bulundurulduğunda, ekonomik gerekçeleri bahane etmeden havalimanlarının yönetimleri tarafından düzeltici önlemlerin uygulamaya alınması gerekmektedir. Bu çalışmada bahsi geçen çevresel problemler değerlendirilerek, Erzurum Havalimanı’nın işletilmesi sürecinde, risk değerlendirmesi yapılması ve çevresel etkilerinin belirlenmesi amaçlanmaktadır. Çalışmada çevresel risk faktörleri belirlenerek, risklerin çevreye olası etkileri L tipi matris metodu ve Fine-Kinney metodu kullanılarak ortaya konulmaya çalışılmıştır. Bu doğrultuda havalimanı bünyesinde yer alan ofis, mutfak, marangozhane, depo, bakım onarım vb. birimlerde çevresel zararlara sebep olabileceği düşünülen çevresel risk etmenleri değerlendirilmiştir. Havalimanında yapılan değerlendirmeler sonucunda L tipi matris metoduyla 11 adet orta, 243 adet katlanılabilir ve 39 adet önemsiz düzey risk tespit edilmişken, Fine-Kinney metoduyla 7 adet yüksek, 31 adet önemli, 136 olası ve 119 adet önemsiz düzey çevresel risk tespit edilmiştir. Alınacak önlemlerin, havalimanının muhtemel çevresel etkilerini büyük ölçüde düşüreceğini göstermektedir.
AtıfOpenAlex2TR Dizin2İncele - MakaleYalnız künye2024Ekonomide Lokomotif Güç: İktisadi Devlet Teşekkülleri (1940-1945)
Uğur, Uçar
Amaç: Bu çalışmanın amacı, Cumhuriyetin ilk yıllarında Türkiye’nin sanayileşme sürecinde önemli bir yere sahip olan İktisadi Devlet Teşekküllerinin (İDT) kuruluş sürecini, ekonomik bağlamını ve faaliyetlerini sayısal verilerle açıklamak ve bu kuruluşların önemini ortaya çıkarmaktır. Bunlara ek olarak bu teşekküllerin hangi sektörlerde faaliyet gösterdiğini ve bu sektörlerdeki üretim, istihdam ve yatırımlara katkılarını incelemek bir diğer amaçtır. Tasarım/Yöntem: Araştırma ele alınırken öncelikle tarih biliminin birinci el kaynaklarından olan arşiv belgelerinden istifade edilmiştir. Bununla birlikte belirlenen tarihler arasındaki döneme ait veriler ulusal basın taranarak veri toplama işlemi gerçekleştirilmiştir. Son olarak konu ile bağlantılı telif ve tetkik eserlerden istifade edilmiştir. Çalışma, doküman analizi şeklinde yapılmış, elde edilen veriler analiz edilerek metin oluşturulmuştur. Bulgular: İktisadi Devlet Teşekkülleri, 1930’lu yılların başında sermaye, müteşebbis, bilgi ve teknik uzman eksikliği ile alt yapı sorunları gibi sebeplerden dolayı özellikle sanayi alanında devletin ekonomiye müdahale etmesi sonucunda kurulmuşlardır. İDT’ler devletin toplumsal alandaki görevlerinden olan halkın refah seviyesinin artırılması sorumluluğunu yerine getirmek ve bunun gerçekleşmesi için gerekli koşulların oluşmasında önemli bir role sahiptir. Ayrıca bu kurumlar kalkınma dönemindeki Türkiye ekonomisine olumlu ve yapıcı bir etki ile katkıda bulunarak özellikle kalkınmaya ve teknolojik ilerlemeye öncülük etmiştir. Konunun özelinde ise İkinci Dünya Savaşı yıllarında İDT’ler, Türkiye ekonomisinin istikrarını korumada ve savaşın olumsuz etkilerini hafifletmede önemli rol oynamıştır. Sınırlılıklar: Çalışmanın en önemli sınırlılığı belirli bir zaman dilimini (1940-1945) ele almasıdır. Bu sınırlandırılmaya gidilmesinin sebebi ise özellikle Devletçilik politikasının hayata geçirilmesiyle birlikte kurulan ilk İDT’lerin İkinci Dünya Savaşı gibi olağanüstü bir dönemdeki faaliyetlerinin ele alınması düşüncesidir. Özellikle 1945 yılından sonraki süreçte küresel dünyada Devletçilik politikasının benimsenmesinde bir yavaşlama söz konusudur. Bundan dolayı çalışma ele alınırken bu çerçevede bir yol izlenmiştir. Özgünlük/Değer: Çalışmayı özgün kılan en önemli özellik birinci el arşiv kaynaklarının kullanılmasıdır. Bir diğer özgün değer ise konunun tarih bilimi bağlamında ve dönemsel olarak ele alınmasıdır. Daha önce ele alınan çalışmalar genellikle bu kurumların özelleştirmelerini konu edinip iktisat biliminde ele alırken, bu çalışma doğrudan İDT faaliyetlerine değinmektedir.
- MakaleAçık Erişim2024The Relationship Between Public Expenditures and Openness in the MIST Countries
Yıldız, Şaduman
After the Second World War, increases were observed in both public expenditures and openness, and researchers started to investigate the relationship between these two variables. As a result of the investigations, three hypotheses revealing the relationship between public expenditures and openness were developed. These hypotheses are the compensation hypothesis, the efficiency hypothesis, and the deindustrialization hypothesis. According to the compensation hypothesis, there is a positive relationship between openness and public expenditures, and openness increases public expenditures. On the other hand, according to the efficiency hypothesis, there is a negative relationship between public expenditures and openness, and openness reduces public expenditures. Finally, according to the deindustrialization hypothesis, there is no relationship between public expenditures and openness. In the present study, the effect of openness on public expenditures in the MIST (Mexico, Indonesia, South Korea, and Turkey) countries was tested via panel data analysis using annual data for the 1960-2021 period. In this respect, as a result of the LM cointegration test, it was concluded that there was a cointegration relationship between the variables of public expenditures and openness. Afterward, a coefficient estimate was made for the variables with the CUP-FM and BA-OLS tests, and a positive relationship was revealed between the variables of public expenditures and openness. Finally, the result of the Fisher causality test supported the result of the LM cointegration test. Thus, it was concluded that the compensation hypothesis was valid in the MIST countries for the 1960-2021 period.
AtıfOpenAlex1TR Dizin1İncele - MakaleAçık Erişim2024Türkiye'de Ekonomik Kalkınma ve Karayolu Trafiğinde Yaralanma ve Ölümler Arasındaki İlişki: Mekânsal Panel Veri Analizi
Elmalı, Kübra; Pekmezci, Fatih
Günümüzde trafik kazaları dünya genelinde ve Türkiye özelinde büyük bir sorun olarak güncelliğini ve önemini korumaya devam etmektedir. Özellikle artan nüfus ve teknolojik gelişme ile birlikte ele alındığında ülkelerin gelişmişlik oranları ile yaşanan trafik kazaları arasında bir ilişki olduğu düşünülmektedir. Bu doğrultuda çalışmada trafik kazaları ve ekonomik büyüme arasındaki ilişkinin araştırılması amaçlanmış olup komşuluk ilişkilerinin de etkisinin dahil edilerek farklı bir bakış açısıyla bakılması hedeflenmektedir. Mekânsal ekonometri yardımıyla diğer illerin komşuluğunun etkisinin de modele dahil edilerek araştırıldığı çalışmada Türkiye’nin 81 iline ait 2013-2022 dönemi verileri kullanılarak uygulamalar yapılmıştır. Çalışmada bağımlı değişken olarak il düzeyinde trafik kazası sonucu oluşan yaralı sayısı değişkeni alınırken bağımsız değişken olarak ise gelir, araç sayısı oranı ve kaza sayısı oranları modele dahil edilmiştir. Modelde yer alan mekânsal ekonometrik analizler bölge komşuluğu ele alınarak yapılan uygulamalardan oluşmaktadır. Bu doğrultuda mekânsal etkiler üç farklı model altında incelenmiştir. Test sonuçlarına göre; modelde yer alan değişkenlerden gelir değişkeni ve araç oranı değişkeni trafik kazası sonucu oluşan yaralanma ile aynı yönde anlamlı bir ilişki göstermektedir.
AtıfOpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ1Optimum steel frame design through ultimate seismic energy dissipation of double diagonal friction dampers
Carbas, Serdar; Artar, Musa
In this paper, a creative design methodology is exhibited to attain seismic design optimization of steel frames that are equipped with double diagonal braces on which Pall friction dampers (PFDs) are mounted. The PFDs supply highest seismic energy dissipation to a structure for restricting destructive structural responds. Hence, the PFDs provide elastic movement to the steel frames to avoid the damaging consequence of an earthquake. To achieve this, the seismic energy dissipation over PFDs mounted on double diagonal brace members are tried to be maximized in this study. The Kobe earthquake record is used for conducting nonlinear dynamic time-history analyses to acquire structural responses of the steel frames. The Jaya algorithm (JA) that is a gradient- and parameter-free metaheuristic optimization technique is selected as an optimizer. The design algorithm encoded in MATLAB is integrated with SAP2000 structural analysis program through inbuilt open application programming interface (OAPI) functions to achieve simultaneous structural seismic responses. In proposed design methodology, firstly the optimal designs of steel frame structures without implementing double diagonal friction dampers are accomplished under effect of seismic loading exposed to structural design constraints of stress, displacement, drift, and geometric taken from AISC-ASD structural specifications. Then, the double diagonal friction dampers are implemented in the optimally sized frames to determine optimum yield strengths which are frictional slip loads. Hereby, the JA makes certain the dissipated seismic energy as maximum by checking the yield strength between the frame stories. In the end, it is verified that the PFD mounted double diagonal friction dampers provide maximum seismic energy dissipation throughout the steel frame structures for optimal sizing.
AtıfScopus8WoS7OpenAlex5İncele - Kitap BölümüAçık Erişim2024Smart and Sustainable Energy Systems
Guclu, Tamer; Cuce, Pinar Mert; Cuce, Erdem
Today, fossil fuels still have a more important share in energy production. Reducing the share of these resources in energy production is an extremely important issue in order to prevent the environmental effects caused by greenhouse gas emissions. Especially in the last ten years, the transformation into smart and sustainable energy systems has accelerated in order to use energy resources efficiently and to reduce greenhouse gas emissions. Smart energy systems are systems that allow the use of renewable energy sources such as solar, wind, and geothermal instead of a fossil fuel-based large production system. Thanks to these systems, instead of a single large power generation facility, energies produced from renewable sources close to the area of use can be integrated into the system, thus reducing greenhouse gas emissions. In addition, smart energy systems are effective in reducing energy costs, as they make final consumers a part of energy production. In addition, since smart energy systems allow the integration of sectors such as electricity, heating, energy, transportation, and transmission, they provide a sustainable, accessible, economical, clean, and efficient energy supply. In this study, information about smart and sustainable energy systems has been given, advantages and difficulties have been mentioned, and also an economic evaluation has been made.
AtıfScopus2OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ1AC transport loss analysis of HTS stack busbars for all-electric aircraft with harmonics and DC offset considerations
Abdioglu, Murat; Gautam, Gaurav; Zhang, Min; Yuan, Weijia
This paper presents a study of the current carrying capacity and AC loss of high-temperature superconducting (HTS) stacks to be used in busbar applications for all-electric aircraft. A 2D model was developed using COMSOL Multiphysics with a T-A formulation for detailed analysis. The study began by applying a stable 20 kA DC offset current to the HTS stacks to simulate practical operating conditions. Firstly, the behaviour of the critical current was studied under self-field conditions for stacks with different numbers of HTS tapes and spacing. Secondly, AC ripple currents were introduced with DC offsets, and the effects of 3rd and 5th harmonic distortions (HD) were studied. The results show that configurations with 40 tapes and gaps of more than 2 mm are considered suitable for safe current transport under DC conditions. On the other hand, increasing the tape spacing leads to an increase in the safe transport current ripple due to the reduced magnetic field interaction within the stack. In addition, the transport loss decreases as the air gap increases due to the reduction in the self-field, whereas it increases as the number of strips increases. The influence of the 3rd HD on the transport loss is minimal at a ripple current of 1% and slightly noticeable at 2%. However, it becomes more obvious as the ripple current approaches the critical value. Remarkably, even cases with equivalent total HD show significantly higher transport losses when characterised by higher 5th HD than their counterparts with 3rd HD. This comprehensive analysis provides valuable information on the performance characteristics of HTS stacks in all-electric aircraft busbar applications and offers important insights for the development and optimisation of these systems in practical aerospace applications.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ1Enhanced thermal and angular velocity-induced hybrid piezoelectric energy harvesting of smart turbine blades
Uyar, Mehmet
In this study, an approach is proposed to examine hybrid piezoelectric energy harvesting performances from vibrations induced by thermal and angular velocity loads in order to generate energy from the smart turbine blade. In the proposed method, a smart turbine blade is formed by patching the piezoelectric material to the root surface of the turbine blade. A finite element (FE) model of the smart turbine blade is established and then it is validated with a smart blade model in a reference study to test the reliability and accuracy of the FE method. The defined loads are applied to the smart blade to obtain energy from mechanical vibrations induced by thermal and angular velocity loads. Temperature distribution, voltage, and vibration results obtained from energy harvesting analysis under different thermal and angular velocity loads are presented. In order to investigate the energy conversion efficiency of the energy obtained from the system, the energy harvesting circuit is tested in terms of battery discharge times and power output values. The results show that while the maximum energy conversion in the thermally induced smart turbine blade is 11.9 W, a power output of 12.3 W is obtained from the hybrid energy harvesting mechanism under angular velocity and heat flux loads.
AtıfScopus5WoS5OpenAlex3İncele - Kitap BölümüYalnız künye2024A hybrid method for determining the export sector and product for Turkey: Bayesian econometrics and multi-criteria decision analysis
Ozden, Erdemalp; Yaprakli, Sevda
Developing economies need to support strategic sectors that will transform their productive structures to ensure development. Therefore, the ability of these strategic sectors to produce exportable products is essential. This study follows a different path to determine strategically important export sector and products for Turkey, one of the countries struggling with the middle-income trap for a while. This different path is a hybrid method by combining the results of Bayesian econometrics with the analytical hierarchy process (AHP) method, one of the multi-criteria decision making (MCDM) methods. As a result, the export sector that should be prioritized is transportation, and export products are cars and vehicle parts. By applying the hybrid method in this study to other countries, strategic sectors and goods can be determined.
- MakaleAçık Erişim2024Scopus SJRQ1District heating based on exhaust gas produced from end-of-life tires in Erzincan: Thermoeconomic analysis and optimization
Güngör, Osman; Tozlu, Alperen; Arslantürk, Cihat; Özahi, Emrah
This paper presents the thermoeconomic analysis and optimization of the Erzincan Waste Tire Recycling and Power Plant (EWTRPP) in Turkey and its waste heat-based district heating (DH) system. A thermoeconomical method, namely the specific exergy costing (SPECO), is applied to allocate cost flows through subcomponents of an actual existing plant. Besides, the obtained thermoeconomic results are improved by using an optimization method, namely non-dominant sorting genetic algorithm (NSGA-II), considering the temperature of the exhaust gas discharged to the atmosphere (T25), the thermal conductivity value of the insulation material (ki) and pipe roughness value (s). The energy and exergy efficiencies of the existing plant are found to be 27.37% and 35.57%, respectively, considering the data of the actual plant. Moreover, the energy and exergy efficiencies of the waste heat-based DH system are found to be 43.08% and 55.99%, respectively. The total cost rate of the overall system is deduced 13.98 $/hby means of SPECO method. According to the results of the NSGA-II optimization method, the exergy efficiency and total cost rate of the overall system are evaluated as 6.93% and −2.51 $/h, respectively. Furthermore, it is also proposed that 1304 dwellings can be heated owing to the DH system utilizing the existing exhaust gas.
AtıfScopus9WoS8OpenAlex7İncele - MakaleAçık Erişim2024Scopus SJRQ3Analyzing global competitiveness of Turkish air conditioning industry
İzgi, Fatma; Kavacık, Mustafa
The global economy significantly relies on the air conditioning sector, which has been gaining increased importance worldwide and in Türkiye due to the impact of global warming, climate change, and the diminishing energy resources. As a multifaceted industry encompassing air conditioning, heating, installation, insulation, refrigeration and ventilation sector has been adapting to the growing demand for environmentally friendly and energy-efficient solutions. This study analyzes air conditioning industry of Türkiye and its sub-product groups in terms of its ability to compete internationally, spanning from 2001 to 2021. To assess competitiveness, we employed various analytical tools, including Balassa's Revealed Comparative Advantages Index (RCA), Vollrath Indices (RXA, RMP, RTA, RC), Revealed Symmetric Comparative Advantages Index (RSCA), Trade Balance Index (TBI), and Product Mapping method. Notably, there is no research that scrutinize the competitiveness of the Turkish air conditioning industry utilizing the Product Mapping. The study findings emphasize that air conditioning industry of Türkiye has competitiveness. Within the sub-product group, the analysis reveals that Türkiye has competitiveness for 11 products, a near-limit competitiveness for 3 products, and a lack of competitiveness for 10 products.
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