Karamanoğlu Mehmetbey University
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3D3A class of parallel mechanisms: Design and performance evaluation
No full textThis paper presents a study of 20 six-degrees-of-freedom (DoF) Generalized Stewart–Gough Platform (GSP) type mechanisms in 3D3A class. These mechanisms are characterized by three distance and three angular constraints between their base platforms (BPs) and moving platforms (MPs). The mechanisms are categorized into two groups based on the geometric shapes of their BPs and MPs. The platform shapes are determined by the types of joints and their connection configurations on the platforms. The platforms are designed with regular polygonal shapes. Two groups are generated according to whether the geometric shapes of the platforms are the same or different. There are 10 types of mechanisms in the first group, where the BP and the MP shapes of each are the same. The second group also includes 10 types of mechanisms, each with two design variations, resulting in 20 designs. Thus, a total of 30 mechanisms are designed. The reachable workspaces and dexterities of these manipulators are computed to assess the impact of design parameters such as the ratio between the BP and MP radii and the rotation of one end of the BP edges. The reachable workspace volume and the Global Conditioning Index (GCI) are selected as the performance metrics. The results of all mechanisms are presented in the paper, with a comparison of the two best mechanisms against the classical 3×3 Stewart Platform. The study shows that the D43A13 type mechanism achieves a large reachable workspace while maintaining a high GCI value. © 2024 Elsevier B.V
Fabrication of hydrophobic waste based-microfibers ıncorporated with green synthesized metal oxides for oil/water separation applications
Get PDFDeveloping affordable, long-lasting, and effective membranes is essential for the treatment of oily wastewater, which has become a substantial problem. In this study, an affordable and environmentally-friendly hydrophobic microfibers were designed. Polystyrene wastes were recycled into a functional hydrophobic microfiber. ZnO, CuO, and CuO-ZnO nanoparticles were synthesized using pine pollen waste via green approach. Thereafter, green synthesized nanoparticles were incorporated into recycled polystyrene to fabricated an efficient microfiber. Fabricated microfibers were characterized via FT-IR and XRD, SEM and SEM–EDS. Water contact angle of the polystyrene nanofibers were increased from 123.5° to 139.1° by metal oxide incorporation. Separation efficiency of the polystyrene microfiber was also improved by addition of green synthesized CuO to 81.84%. Notably, these environmentally-friendly membrane nanocomposites can be used in water–oil separation applications successfully
Evaluation of head posture in patients with temporomandibular joint disorders: a cross-sectional study
Get PDFThis study evaluated head posture in patients with temporomandibular joint disorders and explored the effects of postural changes on clinical parameters. METHODS: In total, 81 individuals diagnosed with temporomandibular joint disorders participated in this cross-sectional prospective study. Demographics, pain status, head posture, and jaw movement data were collected. Head posture was assessed using the Posture Screen Mobile application. RESULTS: Results indicated moderate negative correlations between pain and mouth opening (rho=-0.437, p<0.001) and maximum mouth opening (rho=-0.427, p<0.001). Anterior translation showed weak positive correlations with mouth opening and maximum mouth opening, while right lateral translation exhibited a weak positive correlation with pain (rho=0.264, p=0.017). Posterior angulation showed weak significant correlations with pain, mouth opening, and maximum mouth opening. CONCLUSION: These findings suggest that head posture has a significant influence on temporomandibular joint disorder symptoms. Treatment strategies addressing postural abnormalities may help alleviate symptoms and enhance the quality of life in temporomandibular joint disorder patients
Perovskite quantum dots: Fabrication, degradation, and enhanced performance across solar cells, optoelectronics, and quantum technologies
Get PDFMetal halide perovskites exhibit excellent absorption properties, high carrier mobility, and remarkable charge transfer ability, showcasing significant potential as light harvesters in new-generation photovoltaic and optoelectronic technologies. Their development has seen unprecedented growth since their discovery. Similar to metal halide perovskite developments, perovskite quantum dots (PQDs) have demonstrated significant versatility in terms of shape, dimension, bandgap, and optical properties, making them suitable for the development of optoelectronic devices. This review discusses various fabrication methods of PQDs, delves into their degradation mechanisms, and explores strategies for enhancing their performance with their applications in a variety of technological fields. Their elevated surface-to-volume ratio highlights their importance in increasing solar cell efficiency. PQDs are also essential for increasing the performance of perovskite solar cells, photodetectors, and light-emitting diodes, which makes them indispensable for solid-state lighting applications. PQDs' unique optoelectronic characteristics make them suitable for sophisticated sensing applications, giving them greater capabilities in this field. Furthermore, PQDs' resistive switching behavior makes them a good fit for applications in memory devices. PQDs' vast potential also encompasses the fields of quantum optics and communication, especially for uses like nanolasers and polarized light detectors. Even though stability and environmental concerns remain major obstacles, research efforts are being made to actively address these issues, enabling PQDs to obtain their full potential in device applications. Simply put, understanding PQDs' real potential lies in overcoming obstacles and utilizing their inherent qualities
Hadisin Türkçe ifade ediliş tarihine genel bir bakış
Get PDFThe acceptance of Islam by Turks has social, cultural, scientific and artistic manifestations. In this context, the concept of hadith, with all its sub-elements, being expressed in Turkish and turning into a separate field of literature over time, is the result of an interaction related to linguistic as well as scientific. In recent years, it is observed that the number of old textual analyses such as edition criticism, content analysis, takhrīj etc. has increased in hadith studies in our country. However, it is very difficult to say that the published texts were discussed from the perspective of historical science language. This article draws attention to this deficiency and analyses the process of the expression of the concept of hadith in the Turkish language, focusing particularly on the Ottoman Turkish Period. In other words, it deals with the adventure of the science of Hadith to become a field of Turkish literary based on expression, translation, terminology and literature. For this purpose, the course of development of Turkish language is summarized, thus paving the way for making simultaneous comparisons with the history of the Turkish expression of hadith. The research determines the declaration of the Republic as the end point and excludes oral transmissions. Adhering to the article volume; the analysis of the history of the Turkish expression of hadith will be tried to be made through the main lines determined by theoretical readings. Different types of texts included in the analysis sample will be subjected to probing readings and selected passages with highly representative will be briefly processed by data analysis method. According to the preliminary findings, a total of 7 text types are encountered that provide data for the research. In addition, some parallels are observed between the developmental stages of Turkish and the steps it taken becoming a language of science and the phenomenon of the transformation of hadith into a field of Turkish expression and literature. This study reaches an awareness that the publication of old hadith texts written in Turkish is not only important, but also that new works that will be prepared should now be examined from the perspective of the historical scientific language. It also claims that solutions can be found to some field problems that are still up-to-date by archiving, accessing and scanning of the relevant texts. In addition, this research argues that blending our own literary experience with the richness of ancient language will lead to producing more qualified studies
Telationship between financial development and economic structural reform in Türkiye
No full textEkonomik yapısal reformlar, piyasaların etkin ve verimli işleyişinin önündeki engellerin ortadan kaldırılması ve ülkelerin büyümesine katkı sağlanması amacıyla yerine getirilmesi gereken yükümlülükleri ifade etmektedir. Ekonomik yapısal reformların uygulanabilmesi için çeşitli makroekonomik, sosyal, finansal vb. alanlardaki temel ön koşulların sağlanmış olması gerekmektedir. Bu noktadan hareketle bu çalışmada Türkiye’de finansal gelişme ve ekonomik yapısal reformlar arasındaki ilişki, 2002-2021 dönemi için Fourier-Shin (F-Shin) eş-bütünleşme testi ve dinamik en küçük kareler (DOLS) yöntemi kullanılarak incelenmektedir. Analiz sonuçları, Türkiye’de finansal küreselleşme ile ekonomik yapısal reformlar arasında anlamlı bir ilişkinin olmadığını; gayrisafi sabit sermaye oluşumu ile ekonomik yapısal reformlar arasında negatif, doğrudan yabancı yatırımlar ile ekonomik yapısal reformlar arasında pozitif bir ilişkinin varlığını ortaya koymaktadır
Concurrent training method in footballers; speed and agility
No full textBu çalışmanın amacı, 18 yaş ve üzeri futbolculara uygulanan eş zamanlı antrenman metodunun sürat ve çeviklik üzerine etkisini incelemektir. Çalışmamıza, Konya Amatör Süper Ligi'nde mücadele eden 19 gönüllü futbolcu katılmıştır. Bu çalışma yaş ortalaması 20,42±1,07 yıl olan toplam 19 gönüllü futbolcu üzerinde gerçekleştirilmiştir. Katılımcılar random (rastegele) sistemiyle deney (n=10) ve kontrol (n=9) gruplarına ayrılmıştır. Tüm katılımcılar normal fiziksel özelliklere sahip olup herhangi bir sakatlık geçmişine sahip değildir. Her iki grubada çalışma öncesinde futbol sahasında 20m. sürat, 30m. sürat ve çeviklik ön testler yapılmıştır. Çalışmaya başlamadan önce yapılan testlerde deney grubu sürat (20m) ön test ortalaması 2,88±,09 sn., sürat (30m) ön test ortalaması 3,90±,17 sn., çeviklik ön test ortalaması 9,49±,50 sn. olarak bulunmuştur. Kontrol grubunda ise sürat (20m) ön test ortalaması 2,81±,13 sn., sürat (30m) ön test ortalaması 3,84±,12 sn., çeviklik ön test ortalaması 9,31±,35 sn. olarak belirlenmiştir. Araştırmaya katılan deney ve kontrol grubu sporcularında sürat (20m), sürat (30m) ve çeviklik ön test sonuçlarında istatistiksel olarak anlamlı bir farklılık tespit edilmemiştir (p>0,05). Deney grubu, normal antrenman programına ek olarak 6 haftalık eş zamanlı antrenman programına tabi tutulurken, kontrol grubu yalnızca rutin antrenmanlarına devam etmiştir. Yapılan 6 haftalık çalışma sonrrasında yapılan son testlerde deney grubu sürat (20m) son test ortalaması 2,59±,19, sürat (30m) son test ortalaması 3,49±,19 sn., çeviklik son test ortalaması 8,88±,35 sn. olarak belirlenmiştir. Kontrol grubunda ise sürat (20m) son test ortalaması 2,83±,11sn., sürat (30m) son test ortalaması 3,82±,12 sn., çeviklik son test ortalaması 9,30±,45 sn. olarak ölçülmüştür. Araştırmada bulunan deney ve kontrol grubu sporcularında grup içi karşılaştırmaya bakıldığında eş zamanlı antrenman grubu sporcularının sürat (20m), sürat (30m) ve çeviklik ön test - son test değerlerinde anlamlı farklılık bulunmuştur (p0.05). While the experimental group was subjected to a 6-week simultaneous training program in addition to the normal training program, the control group only continued their routine training. In the post-tests conducted after the 6-week study, the speed (20m) post-test average of the experimental group was determined as 2.59±.19, speed (30m) post-test average was 3.49±.19 sec., and agility post-test average was 8.88±.35 sec. In the control group, the speed (20m) post-test average was measured as 2.83±.11 sec., the speed (30m) post-test average was 3.82±.12 sec., and the agility post-test average was 9.30±.45 sec. When the within-group comparison of the experimental and control group athletes in the research was examined, a significant difference was found in the speed (20m), speed (30m) and agility pre-test - post-test values of the concurrent training group athletes (p<0.05). No significant difference was found in the pre-test - post-test speed (20m), speed (30m) and agility values in the control group athletes. When the post-test results of the experimental and control group athletes in the research were compared, a statistically significant difference was found between the 20 m and 30 m speed tests and agility tests (p<0.05). As a result, it was observed that the simultaneous training method was effective in improving the speed and agility performances of football players during the competition period
Evaluation of civil administration in Turkey within the framework of politics-administration dichotomy
Get PDFTürkiye Cumhuriyeti Anayasası’na göre kamu idaresi merkezden ve yerinden yönetim ilkelerine dayanmaktadır. Merkezi idarenin yönetsel kademesi olan il idaresi 1876 tarihli Kanunu Esasi’den buyana yetki genişliği yöntemiyle yürütülmektedir. İl yönetimin başı olan valiler iktidar aygıtının, başka bir ifadeyle yürütme organının temsilcisi ve siyasi-idari icra vasıtası olarak görev yapmışlardır. 2018 yılında Cumhurbaşkanlığı Hükümeti sistemine geçişle birlikte valiler, yürütme organının idari vasıtası olarak tanımlanmış, siyasi fonksiyonlarına son verilmiştir. Bu çalışmada, valilerin yürütme organının siyasi icra vasıtası olma rollerinin sona erdirilmesinin ne anlama geldiği ve hangi sonuçları doğurduğu ya da doğuracağı tartışılacaktır. Konu irdelenirken, kamu yönetimi disiplinin kurucu paradigması olan siyaset-yönetim dikotomisinden ve bürokrasi kuramının araçlarından yararlanılacaktır.According to the Constitution of the Republic of Turkey, public administration is based on the principles of centralized and decentralized administration. Provincial administration, which is the administrative level of the central administration, has been carried out with the method of deconcentration since the Law of 1876. Prefects, who are the head of the provincial administration, have served as the representative of the power apparatus, in other words, the executive branch, and as the instrument of political-administrative execution. In 2018, with the transition to the Presidential Government System, prefects were defined as the administrative instrument of the executive branch, their political functions were terminated. This study will discuss what the termination of the role of governors as the political executive instrument of the executive branch means and what consequences it has had or will have. While analyzing the issue, the founding paradigm of the public administration discipline, the politics-administration dichotomy and the tools of bureaucracy theory will be utilised
Pay piyasasında etkin piyasalar hipotezinin uzun hafıza modelleri ile analizi
Get PDFThe COVID-19 pandemic has precipitated significant alterations not only in global lifestyles and daily routines but also in investment behaviors. This study aims to test the validity of the efficient markets hypothesis in the indices in Borsa Istanbul during the COVID-19 pandemic and the period when the pandemic effects on the country's economies and individuals continued. The study involves analyzing the stationarity of the return series for these equity indexes using both traditional unit root tests (ADF and PP) and those considering structural breaks (Zivot Andrews). Furthermore, the presence of the EMH was examined through the application of long memory models, employing methods such as Geweke and Porter-Hudak, Modified Log-Periodogram, and Robinson Gaussian Semi-Parametric. The findings reveal that the returns of BIST100, BIST50, BIST30, and BISTTUM indexes are non-stationary, do not exhibit mean reversion following shocks, and lack long memory characteristics. These results suggest that investors' attempts to predict price movements of these indexes may be misleading, indicating that only weak-form efficiency could be argued for these indexes.Covid-19 pandemisi, dünya çapında insanların yaşam tarzları ve günlük rutinler üzerinde olduğu kadar yatırım davranışları üzerinde de önemli değişikliklere neden olmuştur. Bu çalışmanın amacı Covid-19 pandemi dönemi ve sonrasında ülke ekonomileri ve bireyleri üzerinde pandemi etkilerinin devam ettiği dönemde Borsa İstanbul’da yer alan endekslerde etkin piyasalar hipotezinin geçerliliğinin test edilmesidir. Araştırma kapsamında, söz konusu pay senedi endekslerinin getiri serilerinin durağanlık durumu, hem geleneksel (ADF ve PP) hem de yapısal kırılmaları göz önünde bulunduran birim kök testleri (Zivot Andrews) aracılığıyla analiz edilmiştir. Ayrıca, Etkin Piyasa Hipotezinin varlığı, uzun hafıza modeli kullanılarak Geweke ve Porter-Hudak, Modifiye Edilmiş Log-Periodogram ve Robinson Gaussian Yarı Parametrik Yöntemlerle incelenmiştir. Araştırmanın sonuçları, BIST100, BIST50, BIST30 ve BISTTUM endekslerinin getirilerinin durağan olmadığını, şoklardan sonraki ortalamalarına dönüş eğilimi göstermediğini ve uzun hafıza özelliği taşımadığını ortaya koymaktadır. Bu bulgular, yatırımcıların bu endekslerin fiyat hareketlerini tahmin etme çabalarının yanıltıcı olabileceğine ve bu endekslerde zayıf formda etkinlikten bahsedilebileceğine işaret etmektedir
Optimization and prediction of colored pervious concrete properties: Enhancing performance through augmented grey wolf optimizer and artificial neural networks.
No full textBu çalışma, deneysel analiz ve yapay zekâ modellemesinin kombinasyonunu kullanarak renkli ve cam elyaf takviyeli geçirimli betonun (GB) tahminini ve optimizasyonunu araştırmaktadır. Küresel ısınmaya bağlı iklim değişiklikleri dünyanın birçok yerinde ani ve aşırı yağışlara neden olmaktadır. Bu yağışlar sonucu birçok yerleşim yeri sel felaketleri ile karşı karşıya kalmaktadır. Sel felaketlerinin kalıcı etkilerini artıran en önemli faktörlerden biri de şehir kaplamalarının gözeneksiz yapısı nedeniyle geçirimsizliğidir. Bu çalışma GB ile bu sorunları çözmek için yapılmış ve geçirgen beton su hareketlerine izin verecek yeterlilikle birbirine bağlı gözenekler oluşturacak şekilde tasarlanmıştır. Ayrıca bu gözenekli yapı ısıyı emmeyerek ısı adası fenomeninin etkilerini de azaltmaktadır. GB'ler, yağmur suyunun boşluklardan sızarak yer altı suyunun yenilenmesine katkı sağlayacak şekilde tasarlanmıştır. Bu boşluklar içinde nüfuz eden suyun bir kısmını tutarak, takip eden kuruma aşamasında buharlaşarak muhtemelen kaplama sıcaklığını düşürebilir. Bu nedenle ısı adası etkisinin azaltılmasına yardımcı olur. Isı adası etkisine sebep olan bir diğer faktör ise kaplamanın yansıtıcılığı veya albedosudur. Bu faktör güneş emilimi (albedo) ve güneş ışınımının çarpımına dayandığından önemli bir faktördür. GB'lerin yansıtıcılığının veya albedosunun kentsel termal ortam üzerindeki etkisi ve bunun altında yatan mekanizmalar tam olarak anlaşılamamıştır; bu nedenle geçirimli betonun albedosunun tanımlanması önemlidir. Dolayısı ile GB'lerin çeşitli pigmentler ile renklendirilmesi ve albedo değerlerinin ölçülmesi yine bu çalışma kapsamında değerlendirilmiştir. GB'lerin mekanik özelliklerini iyileştirmek amacıyla pigmentlerin yanı sıra cam elyaf kullanımı ve bu cam elyaf takviyeli geçirgen betonun aynı anda artan yansıtıcılıkla kentsel ısı adası etkilerini azaltma, yağmur suyu yönetimini iyileştirme ve yapısal bütünlüğü destekleme potansiyeli temel alınmıştır. Bu çalışma, yapay sinir ağları ve gri kurt optimizasyonu aracılığıyla renkli, cam elyaf takviyeli geçirgen betonun basınç ve eğilme ile aşınma direncini optimize ve tahmin etmeyi amaçlamıştır.This study investigates the prediction and optimization of colored and glass fiber-reinforced permeable concrete using a combination of experimental analysis and artificial intelligence modeling. Climate changes due to global warming are causing sudden and extreme rainfall in many parts of the world. As a result of these rains, many settlements are facing flood disasters. One of the most important factors that increase the permanent effects of flood disasters is the impermeability of urban pavements due to their non-porous structure. This study was conducted to solve these problems with permeable concrete, which is designed to create interconnected pores that are sufficient to allow water movements. Additionally, this porous structure does not absorb heat, thus reducing the effects of the heat island phenomenon. Permeable concrete is designed to allow rainwater to seep through the voids, contributing to the replenishment of groundwater. By retaining some of the water that penetrates these voids, it can potentially reduce the pavement temperature through evaporation during the subsequent drying phase. Therefore, it helps to mitigate the heat island effect. Another factor causing the heat island effect is the reflectivity or albedo of the pavement. This factor is significant as it is based on the product of solar absorption (albedo) and solar radiation. The impact of the reflectivity or albedo of permeable concrete on the urban thermal environment and the underlying mechanisms are not fully understood; therefore, defining the albedo of permeable concrete is important. Consequently, the coloring of permeable concrete with various pigments and the measurement of albedo values are also evaluated within the scope of this study. To improve the mechanical properties of permeable concrete, in addition to pigments, the use of glass fiber and the potential of this glass fiber-reinforced permeable concrete to simultaneously reduce urban heat island effects, improve rainwater management, and support structural integrity are considered. This study aimed to optimize and predict the compressive and flexural strength and abrasion resistance of colored, glass fiber-reinforced permeable concrete through artificial neural networks and grey wolf optimization