Garip Genc

Finishing processes such as dyeing, washing, drying, and shaping applied during fabric production may distort the textile structure, leading to angular deviations between warp and weft yarns. Weft straightening machines (WSMs) are employed in industrial production lines to monitor and correct these deviations; however, existing systems often exhibit limited robustness and accuracy under high-speed operating conditions. Undetected small angular errors may therefore evolve into irreversible structural defects, particularly during drying and finishing stages. In this study, a deep learning–based weft skew detection approach is proposed for real-time angle estimation in industrial WSMs using an oriented bounding box (OBB)-based object detection framework. The YOLOv8-OBB architecture is adopted due to its ability to jointly estimate object localization and rotation with high computational efficiency, making it suitable for real-time industrial applications. The model is trained and evaluated on images of five fabric types processed at production speeds ranging from 10 to 130 m/min. Experimental results demonstrate that the proposed method achieves mAP@0.5 values between 85% and 91%, enabling accurate and reliable detection of warp and weft orientations. The findings indicate that the proposed approach provides an effective and scalable solution for real-time quality control and angle-based correction in textile finishing lines.

This study presents a numerical investigation of the influence of channel geometry on electrohydrodynamic (EHD) processes governing particle transport in electrostatic precipitators (ESPs). A conventional rectangular channel is compared with concave configurations using a coupled multi-physics model that accounts for gas flow, electric field distribution, ion transport, and particle migration across a wide particle-size range. The results show that geometric modification significantly alters ion transport and charge distribution within the ESP channel. Compared with the rectangular configuration, the concave profile enhances ion penetration and particle charging, leading to improved collection efficiency across the entire particle-size range. The improvement is particularly pronounced near the minimum-efficiency region for submicron particles. Specifically, near 0.1 μm, the collection efficiency increases from approximately 30% in the rectangular channel to approximately 50% for the higher-contraction concave configuration, representing an improvement of nearly 20 percentage points. A comparison with a Venturi-like contraction further shows that abrupt geometric contraction produces localized space-charge accumulation and reduces the effective charging region. In contrast, smooth concave shaping promotes a more distributed electrostatic interaction region, resulting in improved particle collection performance.

This study presents a comprehensive investigation into the structural design and mechanical performance of carbon fiber-reinforced pressure vessels, which have become increasingly prominent in high performance engineering sectors due to their outstanding strength to weight ratio. The research primarily explores the effects of varying composite winding angles - specifically 30°, 45°, and 75°- along with different layer thickness configurations on the vessels’ structural behaviour. These variables were examined through finite element analysis in terms of stress distribution, deformation response, and failure susceptibility under internal loading conditions. The von Mises stress analysis indicated that the configuration with a 75° winding angle exhibits the lowest stress concentration among all tested cases. This suggests that the 75° angle is the most structurally favourable, contributing to enhanced mechanical safety and durability. To further evaluate the failure behaviour, the study employed the Tsai-Hill, Tsai-Wu, and Maximum Stress failure criteria. These established composite failure theories were utilized to determine the optimal set of design parameters that would minimize the likelihood of structural failure. Moreover, the investigation extended to a comparative analysis of titanium and composite layer thickness combinations. The results revealed that layer thickness significantly influences not only the stress levels but also the displacement characteristics of the structure. Accordingly, the study proposes optimized thickness configurations that improve structural performance while maintaining safety margins. In conclusion, the findings confirm that carbon fiber-reinforced pressure vessels offer considerable advantages over traditional metal vessels, particularly in applications where weight reduction and mechanical efficiency are critical. The insights derived from this study contribute valuable knowledge toward the design of advanced, lightweight, and structurally reliable composite pressure vessels.

Nowadays, aviation and space applications are technologies that are becoming increasingly important. It is essential that these technologies are highly energy efficient and can be applied effectively. The central systems of an aircraft can be listed as navigation and communication, power control systems, flight control systems, and collision avoidance systems. Hydraulic energy is required for the flight control systems, one of the central systems of the aircraft. In an aircraft, hydraulic systems can generally be used in flight control (such as ailerons, horizontal elevators, high-lift gear), landing gear (such as brakes, steering, and landing gear bending), door and stair systems (such as cabin and cargo doors, ramps), and main power (such as propeller brakes, reverse engine operation). Cylinders (actuators), the final element of power transmission in hydraulic systems, are among the most important movement elements. Hydraulic cylinders are elements that convert hydraulic energy into mechanical energy linearly. Hydraulic cylinders are usually made of steel, aluminum alloy, or titanium alloys in aviation. Hydraulic cylinders are heavy due to the high working pressure conditions they provide. This makes it challenging to use in aircraft. A heavy cylinder can also limit the desired mobility in the system to be limited, causing excessive fuel consumption, shortening the aircraft's mission time, and reducing the range. For these reasons, it has been observed that there is a tendency towards composite materials in aviation and space applications. This study evaluates that a hydraulic cylinder is optimized with appropriate calculations and design and made of composite material and titanium alloy. The strength values of the cylinder formed with carbon fiber wrapped on the titanium alloy cylinder tube at two different angles were compared with the finite element method. Two different windings were made with angles of 75/90/-75/90 and 45/90/-45/90 using the finite element method. As a result of the comparison, it was determined that the 75/90/-75/90 winding had approximately 25% higher strength value than the 45/90/-45/90 winding.

Küresel bazda enerji talebi, sanayileşmenin gelişmesi ve elektronik cihazların hızlarının artması ve boyutlarının küçülmesiyle yoğun bir şekilde artmaktadır. Dünya enerji payına bakıldığında binalar için harcanan ısı enerjisinin en yüksek orana sahip olduğu görülmektedir. Bu bağlamda ısı enerjisinde sağlanabilecek tasarruflar küresel enerji sorununa katkı sağlayacaktır. Öte yandan bu tasarruf metotların/malzemelerin çevre dostu ve yeşil kaynaklı olması karşı karşıya kaldığımız çevresel sorunların sebebiyle elzemdir. Bu çalışmada, potansiyel ısı yalıtım malzemesi olarak değerlendirilen kabak lifi, Jüt lifi ve bu liflerin hibritleştirilmesi (kabak+jüt) yöntemiyle elde edilen biyokompozit malzemelerin ısı iletim katsayıları üç farklı sıcaklık değerinde belirlenmiştir. Bitkisel lifler takviye elemanı olarak kullanılmış olup matris olarak epoksi kullanılmıştır. Bu bağlamda biyokompozit malzeme numuneleri için testler gerçekleştirilmiş ve mevcut piyasada kullanılan ısı yalıtım malzemeleri ile karşılaştırılmıştır. Sonuçlar literatürdeki bilgiler ışığında tartışılmış ve öneriler sunulmuştur.

Hidrojen enerjisi dizel tren setlerinin yol açtığı hava kirliliği, gürültü kirliliği gibi dezavantajları ortadan kaldırdığı gibi elektrikli tren setlerinin ihtiyaç duyduğu pahalı elektrifikasyon alt yapısı ve görüntü kirliliğinin de olumsuz etkilerini ortadan kaldırmaktadır. Bu olumlu özelliklere karşı hidrojenin yüksek basınç altında depolanması gerekmektedir. Bu çalışmada hidrojenin alternatif bir enerji kaynağı olarak demiryolu araçlarında kullanılması ve hidrojen tüplerinin yüksek hızlı darbeye karşı dirençleri sonlu elemanlar yöntemi ile incelenmiştir. Bu amaçla yüksek iç basıncı olan ve olmayan Karbon Fiberle Güçlendirilmiş Plastik (CFRP) kompozit tüp üzerine darbe yüklemesinin etkisi FEM simülasyonu ile araştırılmıştır. Alüminyum silindirli ve karbon fiber ile sarılmış kompozit tüp 3 boyutlu model kullanılarak simüle edilmiştir. MARC-Mentat ticari kodu, hesaplama aracı olarak seçilmiştir. Silindirin geometrisi, Mentat ön-son arayüz yazılımı kullanılarak oluşturulmuştur. Alüminyum 6061T astar ve TORAY T 700SC + Epoksi kompozit katmanların malzeme özellikleri sırasıyla izotropik ve ortografik olarak simülasyonlara dâhil edilmiştir. Tüpün kubbe bölgesi simülasyonlara dâhil edilmemiştir. Simülasyonun modeli, başka bir araştırmacı tarafından yapılan gerçek deney dikkate alınarak oluşturulmuştur. Simülasyonların sonuçları, çarpma tertibatı hasarı altındaki bazı bölgelerin, genellikle inanılan gerilim deformasyonundan ziyade sıkıştırma gerilmelerine maruz kalacağını göstermektedir.