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Unravelling the Spatiotemporal Exciton Dynamics in Electrically Pumped Organic Laser Diodes
No full textOrganic materials offer wide-band emission covering regions of the spectrum unachievable by conventional semiconductors. If electrically pumped lasing could be demonstrated using these materials, many new classes of optical sensors and detectors could be realized leaving a profound impact on society. Devices fabricated from conducting molecules and polymers have already been demonstrated with polaron densities higher than those which theoretically lead to lasing action; however, threshold remains elusive. Herein, a polymer micro-OLED is reported that achieves record room-temperature current densities of 1.5 (Formula presented.), however despite this, it is not high enough to reach lasing threshold. Using a combination of nanosecond spectrographic techniques and detailed simulation, the mechanisms inhibiting lasing action is unraveled. It is shown that although as previously thought singlet-triplet annihilation is important in pushing threshold higher, photon absorption by excited triplets is as (if not more) important in inhibiting lasing action. The complex dynamics of singlets, triplets, and free/excited polarons in these disordered materials are visualized; establishing a pathway to overcome these bottlenecks and realise electrically pumped organic lasing action. © 2025 Elsevier B.V., All rights reserved.Engineering and Physical Sciences Research Council, EPSRC, (EP/V037862/1, EC/RF080422); Engineering and Physical Sciences Research Council, EPSRC; Leverhulme Trust, (RPG‐2024‐009); Leverhulme Trus
Physicochemical Properties, Cooking and Sensory Qualities of Noodles Made from Wild Purslane (Portulaca oleracea L.) Seeds and Aerial Parts
No full textPurslane (Portulaca oleracea L.) is an annual plant that has strong pharmacological properties and high nutritional quality. In this study, the impacts of incorporating leaves, stems, whole plants, and seeds of purslane at 0, 3, 6, 9, and 12% levels on the physicochemical, nutritional, and sensory quality of Turkish egg noodles were investigated. The increasing level of purslane parts from 0% to 12% decreased L* values of noodles. Among the purslane parts, purslane seeds showed the highest a* and the lowest SI values at a 12% usage level. The addition of stem, whole plant, and seed powders at a 12% level revealed similar water uptake and volume increase results in noodles to the control. Compared to the control, the inclusion of a 12% level of the aerial parts (leaves, stems, and whole plants) of purslane increased the cooking loss values of noodles. However, purslane seed powder showed similar cooking loss values in noodles to the control. Besides that, the noodles made from 12% stem powder had a greater cooking loss value than the other samples. The firmness values of noodles containing 12% leaf and stem powders were close to control. However, the use of seed powder at a 12% level resulted in the greatest firmness value in noodles. Noodles fortified with 12% of the aerial parts of purslane had a superior nutritional quality with higher ash, Ca, K, Mg,and total phenolic contents and lower carbohydrate and phytic acid levels and energy values than the control. Among the purslane parts, the inclusion of 12% seed powder showed the highest fat (48.3 g kg-1) and phytic acid (3.81 g kg-1) contents in noodles. Also, the energy value of noodles enriched with 12% seed powder was greater than noodles enriched with 12% aerial parts. Noodles containing 3 and 6% purslane powders showed comparable overall acceptability values to the control. The study showed that purslane parts (especially whole plants, up to 9%) can develop the nutritional quality of cereal-based foods such as noodles with acceptable cooking properties and sensory quality. © 2025 Elsevier B.V., All rights reserved
Rainfall Trends in the Transboundary Euphrates-Tigris River Basin
No full textClimate change and anthropogenic factors have a significant impact on rainfall variability. In this study, the trends of monthly total precipitation in the transboundary Euphrates-Tigris River Basin (ETRB), where these effects are intensely observed, were analyzed by trend analysis methods with various perspectives. After decomposing the monthly total rainfall series (1964-2021) obtained from 18 stations representing 12 months of the year, statistical (Mann-Kendall, Wilcoxon, Onyutha), graphical (Innovative Polygon Trend Analysis, IPTA), Trend Polygon Star Concept, TPSC), sub-trend (Onyutha) and spatial trend analyses were performed. Based on the results, it was observed that rainfall in the basin has significant spatial and temporal variability. A monotonic strong decreasing trend was observed in cold months with high rainfall, while an increasing trend was observed in warm months with low rainfall. Extreme rainfall during the winter months has shifted towards the end of the cold months. Graphical and statistical analysis methods have shown strong consistency in identifying monotonic trends. However, the implementation of various methods provides specific insight (transition, sub-trend, etc.) into the temporal and spatial variability of rainfall. Sub-trend analysis shows that rainfall characteristics in the cold months show a significant change before and after the 1990-2000 period. In warmer months, this variability is significantly affected by local and global driving forces. The central and marginal parts of the ETRB have different rainfall characteristics. During cold months, the monotonic trend (decreasing) is significant in the central part. In warm months, the monotonic trend (increasing) increases its intensity in the eastern parts
Effect of Manufacturing Orientation on Solid Particle Erosion at High Temperatures in Inconel 718 Alloys Produced by SLM Method
No full textThis study investigates durability of turbine blades made from Inconel 718 alloy against solid particle erosion under high-temperature conditions. Solid particle erosion wear tests were conducted in accordance with the ASTM G76 standard to carry out the research activity. Experiments were conducted on Inconel 718 specimens produced via selective laser melting (SLM) at orientations of 0°, 45°, and 90°, and compared with cast specimens. Erosion tests were performed using 375-micron aluminium oxide (Alinf>2/inf>Oinf>3/inf>) particles with impact angles of 30° and 45°, at temperatures of 22 °C, 250 °C, and 500 °C. In the experimental process, the effects of temperature increase and specimen build orientation, an important parameter in metal additive manufacturing, on solid particle erosion wear were investigated. After the tests, the wear of the specimens was measured using a precision balance. In addition, the worn specimen surfaces were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). The results showed that, at room temperature, conventionally manufactured (cast) specimens experienced approximately 0.050 g of weight loss, whereas additively manufactured SLM specimens exhibited lower losses: ~ 0.038 g for horizontally oriented (0°), ~ 0.035 g for inclined (45°), and ~ 0.039 g for vertically oriented (90°) samples. Accordingly, SLM-produced specimens were found to undergo approximately 22–30% less wear compared to cast specimens. With increasing temperature, wear decreased in all specimens. Detailed surface examinations further revealed that 250 °C constitutes a critical temperature for IN718 material. At this temperature, a distinctive erosion damage mechanism, namely particle embedment into the surface, was observed. Moreover, under high-temperature tests, SLM specimens with different orientations exhibited ~ 0.005 to 0.01 g lower wear than their counterparts. Additive manufacturing technologies represent a contemporary innovation, and while studies exist in the literature focusing on processing parameters, there is still a lack of research addressing the erosion wear behavior of additively manufactured components for aerospace applications. In particular, the combined effects of build orientation and elevated temperature on erosion remain underexplored. Therefore, this study helps to clarify this gap in the literature and provides new findings, including the identification of 250 °C as a critical temperature and the demonstration of orientation-dependent erosion behavior in layer-by-layer manufacturing. © 2025 Elsevier B.V., All rights reserved.Konya Teknik Üniversitesi, KTUN, (232210045); Konya Teknik Üniversitesi, KTU
Design and Implementation of Internal Logistics System in a Vehicle-Mounted Crane Manufacturing Company
No full textVehicle Routing Problem (VRP), one of the most important internal logistics problems of the manufacturing sector today, aims to determine the route with the minimum distance for transportation vehicles that meet the demands of the customers. In line with this goal, many studies are being conducted on internal logistics problems, and solution methods are being developed. Within the scope of this thesis, literature review on internal logistics applications has been conducted, and the definition of an internal logistics transportation problem in a real-life crane manufacturing company that can be evaluated within the scope of Stacker Crane Problem has been made. In order to do the solving of the problem, a mathematical model has been created by adding inequalities that provide real-life conditions. At this model, there are basic restrictions in the MTSP, such as visiting each customer only once, the trajectory of the routes starting and ending at the depot and the nodes that each vehicle can go to. In order to provide experimental studies, the 15-days work process in the company was followed, and the work data of three transportation vehicles were obtained. The distances between the nodes of the company and the weights and pallet needs data were obtained. In line with the data received, the optimized routing way of three transport vehicles was carried out using the GAMS/CPLEX package program. As a result of the solution of the mathematical model made by applying it to the company, optimal results were achieved compared to the current situation. According to the results of the study, significant improvements have been made in the internal logistics process of the crane manufacturing company, and operational efficiency has been achieved. As a result of optimization studies carried out using 15-days real internal logistics data, the increasing of the 55.72 % efficiency was achieved in internal logistics operations. Comparisons between the current situation and the optimization study have revealed important information for the improvement of internal logistics processes. This thesis contributes to significant improvements in the internal logistics processes of the company where the application is made by showing the strategic importance of lean production and internal logistics in the crane manufacturing sector.Günümüzde üretim sektörünün en önemli iç lojistik problemlerinden biri olan Araç Rotalama Problemi(ARP), müşterilerin taleplerinin karşılandığı taşıma araçları için minimum mesafedeki rotayı belirlemeyi hedeflemektedir. Bu hedef doğrultusunda iç lojistik problemleri üzerine birçok çalışma yapılmakta ve çözüm yöntemleri geliştirilmektedir. Bu tez kapsamında, iç lojistik uygulamaları ile ilgili literatür taraması yapılmış olup İstifleyici Vinç Problemi kapsamında değerlendirilebilecek, gerçek hayattaki vinç imalatı yapılan bir firmadaki iç lojistik taşıma probleminin tanımı yapılmıştır. Problemin çözümünü yapmak amacıyla gerçek hayattaki şartları sağlayan eşitsizlikler eklenerek bir matematiksel model oluşturulmuştur. Bu modelde her müşteriye sadece bir kez uğranması, rotaların yörüngesinin depoda başlayıp depoda bitmesi ve her aracın gidebildiği düğümler gibi temel kısıtlar vardır. Deneysel çalışmaları sağlamak için, firmadaki 15 günlük iş süreci takip edilerek üç taşıma aracının iş verileri alınmıştır. Firmaya ait düğümler arasındaki mesafeleri ve ağırlıklarla palet ihtiyaçları verileri alınmıştır. Alınan veriler doğrultusunda üç taşıma aracının optimize edilmiş rotalama güzergahı GAMS/CPLEX paket programı kullanılarak gerçekleştirilmiştir. Araştırma sonuçlarına göre, vinç imalatı yapılan işletmenin iç lojistik sürecinde önemli iyileştirmeler sağlanmış ve operasyonel verimlilik elde edilmiştir. 15 günlük gerçek iç lojistik verileri kullanılarak gerçekleştirilen optimizasyon çalışmaları sonucunda iç lojistik operasyonlarında %55,72 oranında verimlilik artışı elde edilmiştir. Mevcut durum ve yapılan optimizasyon çalışması arasındaki karşılaştırmalar, iç lojistik süreçlerinin iyileştirilmesine yönelik önemli bilgiler ortaya çıkarmıştır. Bu tez, vinç imalatı sektöründe yalın üretim ve iç lojistiğin stratejik önemini göstererek uygulamanın yapıldığı işletmenin iç lojistik süreçlerinde önemli iyileştirmeler konusunda katkı sağlamaktadır
Use of Shifting Bottleneck Metaheuristic Algorithm and NZN-Area Method in Priority Assignment in Agile It Teams: A Study on Ambiguous Priority Relationships
No full textAssigning priority in agile IT teams can be particularly challenging when dealing with uncertain priority relationships between Product Backlog Items (PBIs) and findings received within a sprint. The Shifting Bottleneck metaheuristic algorithm is crucial in this context, as it helps identify and address bottlenecks that can move from one part of the process to another, impacting the overall workflow. By focusing on the shifting bottleneck, teams can dynamically adjust their priorities to tackle the most pressing issues first, ensuring a steady pace and continuous delivery of value. The Neutrosophic Z Number Set’s-Area (NZN-Area) method complements this approach by visually identifying which tasks should be prioritized, helping to balance the workload and ensure that high-impact tasks are not overlooked. This method provides a structured approach to prioritize tasks, considering various factors with fuzzy AHP such as urgency, business value, resource availability, external dependency and importance. By integrating the Shifting Bottleneck algorithm with the NZN-Area: Ellipse method for prioritization. Agile IT teams can make more informed and nuanced decisions on task prioritization, addressing the most critical tasks first and maintaining efficiency despite the inherent uncertainties in priority relationships. By using multi-criteria decision-making methods and metaheuristic assignment method in PBI prioritization of agile working teams, an 8.6% improvement was achieved in the completion time of intra-sprint PBIs between the existing method and the proposed method. © 2025 Elsevier B.V., All rights reserved
The Extension over Time of the Formation of Built Environment and Pressure to Change the Plan: A Study of the Case of Bağlıca (Ankara)
No full textPlanning is defined as the process of analyzing the goals and projections and reaching some decisions as a result. The concept of development plan means giving detailed information about the place where development plans will be implemented. Development plans, which affect the physical, social and economic structure of a region, shape the way the area is used, its structural arrangements and environmental factors. In Turkey, development plans of different scales and qualities are approved and implemented by different institutions and organizations. In Turkey, planning and implementation processes are generally considered independently rather than simultaneously. In other words, planning and implementation processes are disconnected from each other. However, in development plan studies, implementation processes are as important as the production of the plan. Therefore, it is necessary to examine the structure that causes the built environment in Turkey not to be formed for a long time, many plan changes over time, disruption of the integrity of the plan and the emergence of social and economic problems arising from these. In this study, the basic principles related to the production and implementation processes of development plans in Turkey are mentioned, the planning and implementation processes in the world are described, and the tools used in the implementation of plans and the holistic formation of the built environment are explained. In addition, the tools and legal regulations used in the past for the holistic formation of the built environment in Turkey, and how they prevented the pressure of plan changes, social and economic problems are mentioned, and the problems in front of the holistic formation of the built environment in Turkey are evaluated. Finally, the hypothesis that the lack of holistic implementation of the built environment increases the pressure for plan changes is discussed by examining the planning-implementation process of the Bağlıca neighborhood in Ankara. As a result of the research and analysis conducted in Bağlıca, the hypothesis that spreading the formation of built environment over time increases the pressure for plan changes has been confirmed.Planlama, belirlenen hedef ve projeksiyonlara yönelik yapılan analizler ve bunun sonucunda da bazı kararlara varma süreci olarak tanımlanmaktadır. İmar planı kavramı ise imar planlarının uygulanacağı yer hakkında ayrıntılı bilgilerin verilmesi demektir. Bir bölgenin fiziki, sosyal ve ekonomik yapısını etkileyen imar planları, alanın kullanım şeklini, yapısal düzenlemelerini ve çevresel faktörlerini şekillendirmektedir. Türkiye'de farklı ölçekteki ve nitelikteki imar planları, farklı kurum ve kuruluşlar tarafından onaylanıp, uygulamaya geçilmektedir. Türkiye'de genellikle, planlama ve uygulama süreçleri birbirleri ile eş zamanlı değil bağımsız olarak değerlendirilmektedir. Bir başka deyişle, plan ve uygulama süreci birbirinden kopuk olarak ilerlemektedir. Ancak, imar planı çalışmalarında planın üretilmesi kadar uygulama süreçleri de önem arz etmektedir. Dolayısıyla Türkiye'de yapılı çevrenin oluşumunun zamana yayılmasına, zaman içerisinde birçok plan değişikliği yapılmasına, planın bütünlüğünün bozulmasına ve bunlardan kaynaklı sosyal ve ekonomik sorunların ortaya çıkmasına neden olan yapının irdelenmesi gerekmektedir. Bu çalışmada, Türkiye'de imar planlarının üretilme ve uygulama süreçlerine ilişkin temel ilkelerden bahsedilerek, Dünya'da planlama ve uygulama süreçlerinin nasıl olduğundan, planların uygulanması ve yapılı çevrenin bütüncül olarak oluşumu sürecinde hangi araçların kullanıldığından bahsedilmiştir. Bununla birlikte, geçmişte Türkiye'de yapılı çevrenin bütüncül olarak oluşturulmasına yönelik kullanılan araçlar ve yasal düzenlemelerin, plan değişikliği baskısını, sosyal ve ekonomik sorunları nasıl önlediğinden bahsedilerek, günümüzde Türkiye'de yapılı çevrenin bütüncül olarak oluşumunun önündeki sorunlar değerlendirilmiştir. Son olarak, yapılı çevrenin bütüncül olarak uygulanmamasının, plan değişiklikleri baskısını artırdığı hipotezi, Ankara-Bağlıca Mahallesi planlama –uygulama süreci irdelenerek tartışılmıştır. Bağlıca özelinde yapılan araştırma ve analizler neticesinde yapılı çevre oluşumunun zamana yayılmasının plan değişikliği baskısını artırdığı hipotezi doğrulanmıştır
Osmaniye Dogruözler Mansion within the Scope of Refunctioning
No full textKentleşme sürecinde yaşanan olumsuzluklar, toplumsal yaşamdaki değişiklikler, sosyo-kültürel ve dış etkenler gibi nedenlerle tarihi yapılar zaman içerisinde özgün işlevleri ile kullanılamamaktadırlar. Koruma bağlamında tarihi yapıların yeniden işlevlendirilerek kullanımı, kentin sahip olduğu kültürel ve mimari değerlerin yaşatılmasında önemli bir uygulamadır. Değerlerin yaşatıldığı bu koruma anlayışı ile yapı yaşamına devam etmekte, aynı zamanda ekonomik ve kültürel açıdan süreklilik sağlanmaktadır. Ancak binalara yeni kullanımlar tanımlanırken yapılacak düzenlemelerde yapının mevcut mekân kurgusu göz önünde bulundurularak, yapıya en az müdahale ile en uygun işlevin verilmesi gerekmektedir. Bu yaklaşım doğrultusunda; çalışmada Osmaniye’nin mimari dokusunu yansıtan ve kentteki koruma çalışmalarının ilklerinden olan “Doğruözler Konağı”nın yeniden işlevlendirme süreci ele alınmıştır. Osmaniye çarşısı içerisinde kalan, konut olma işlevini yitiren yapı, süreç içerisinde satın alma yoluyla Osmaniye Belediyesine geçmiştir. 2015 yılında Osmaniye Belediyesinin misafirlerini ağırlamak için restorasyonu yapılan tarihi bina, kullanılmaması ve bakımı yapılmaması sebebiyle atıl kalmıştır. Konağın, 2022’de yeniden işlevlendirme yöntemi ile “Mutfak Müzesi’ne” dönüşümü planlanmış, revize restorasyon projeleri hazırlanmıştır. Çalışmada Mutfak Müzesi olarak yeniden kullanıma açılması planlanan yapının yeni işlev ile mekânsal açıdan uyumunu ortaya koymak ve yeniden kullanımda işlev seçiminin önemine dikkat çekmek istenmektedir. Bu doğrultuda “Doğruözler Konağı” örneğinden hareketle tarihi yapıların yüklenecek yeni işlevlerle kültür hayatımıza kazandırılması konusuna bir bakış açısı geliştirmek hedeflenmektedir. Bu bağlamda tarihi yapıların yeniden kullanımındaki işleve olan uyumu çevresel ve mimari ölçekte analizlerle “Doğruözler Konağı” üzerinden sorgulanmış ve tarihi yapılara verilecek yeni işlevler için bir altlık oluşturmak amaçlanmıştır
Discrete Wavelet Transform-Based Data Fusion With Resunet Model for Liver Tumor Segmentation
No full textLiver tumors negatively affect vital functions such as digestion and nutrient storage, significantly reducing patients' quality of life. Therefore, early detection and accurate treatment planning are of great importance. This study aims to support physicians by automatically identifying the type and location of tumors, enabling rapid diagnosis and treatment. The segmentation process was carried out using deep learning methods based on artificial intelligence, particularly the U-Net architecture, which is designed for biomedical imaging. U-Net was modified by adding residual blocks, resulting in a deeper architecture called ResUNet. Due to the limited availability of medical data, both normal data fusion and discrete wavelet transform (DWT) methods were applied during the data preprocessing phase. A total of 131 liver tumor images, resized to 120 x 120 pixels, were analyzed. The DWT-based fusion method achieved more successful results, with a dice coefficient of 94.45%. This study demonstrates the effectiveness of artificial intelligence-supported approaches in liver tumor segmentation and suggests that such applications will become more widely used in the medical field in the future
Analysing the Relationship Between Space Quality and Place Attachment in Urban Coasts Using Structural Equation Modelling: The Antalya Konyaaltı Case
No full textThe physical and social characteristics of urban design can influence the degree to which users develop attachment to a place. This study aims to identify spatial quality factors in urban coastal areas, analyse their effects on place attachment and provide a theoretical framework for the design of urban coastal spaces. Conducted in the Antalya-Konyaalt ; imath; urban coastal area, the study identified quality factors through Exploratory and Confirmatory Factor Analyses, thereby developing a valid and reliable measurement tool. Place attachment levels were assessed based on the scale developed by Williams and Vaske (Williams, D. R., ; Vaske, J. J. (2003). The measurement of place attachment: validity and generalizability of a psychometric approach. Forest Science, 49(6), 830-840. https://doi.org/10.1093/forestscience/49.6.830). Survey data were collected from coastal subareas that differ in design characteristics and analysed using ANOVA, regression analysis and structural equation modelling (SEM). The findings indicate that the factors alone are insufficient to explain place attachment; however, the structural model established through SEM reveals these relationships with strong model fit values. While all factors were found to have a positive effect in the regression analysis, SEM results showed that particularly green space quality, vibrancy, safety and ease of movement significantly influence place attachment. The observed negative relationship between green space quality and place attachment suggests that the physical qualities of these spaces alone are not sufficient to foster attachment, especially in the presence of deficiencies in accessibility, continuity and other spatial attributes. As a result, the combined use of different analytical techniques has provided an opportunity to evaluate the phenomenon of place attachment in coastal spaces in a more comprehensive and in-depth manner. This study provides a theoretical foundation for the relationship between coastal spatial quality factors and place attachment, offering a substantial basis for developing design strategies specific to urban coastal contexts