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Solving queue problems in a campus dining service with discrete event simulation
No full textWaiting in long queues is a common experience. Prolonged waiting times inevitably result in the formation of queues. While queues are a natural part of service systems, excessive waiting times can reduce customer satisfaction. Campus dining service (CDS) facilities are particularly susceptible to queuing issues when their capacity is insufficient. Long wait times can negatively affect customer experience, making effective queue management essential. To enhance operational efficiency and improve the dining experience, appropriate measures should be implemented to reduce congestion. In this research, a discrete event simulation model of a CDS was developed and analyzed. The study aims to devise low-cost solutions for queue problems through scenario-based analysis. Hypotheses were derived from existing literature and adapted to the specific characteristics of the system under study. Various scenarios were tested to assess the effectiveness of different queue management strategies. The results indicate that capacity reallocation strategies are the most effective in mitigating long queues and improving overall system performance. The findings provide practical recommendations for optimizing CDS operations, offering insights that can be applied to similar service environments facing queuing challenges
Neonatal multisystem inflammatory syndrome (mis-n) associated with prenatal maternal sars-cov-2: A single-center experience
No full textObjectivesNeonatal Multisystem Inflammatory Syndrome (MIS-N) is believed to result either from the transplacental transfer of maternal SARS-CoV-2 antibodies or from a delayed hyperinflammatory response triggered by the neonate's own immune reaction to SARS-CoV-2 infection. In this study we aim to explore the clinical presentation, laboratory findings, and current approaches to the diagnosis and management of MIS-N in neonates.Material and MethodA total of 15 infants with MIS-N followed in Bursa Uludag University Neonatal Intensive Care Unit between January 2022 and January 2023 were included in this retrospective study.ResultsEight mothers had a history of COVID-19 disease during pregnancy. All of neonates had cardiac involvement (supraventricular tachycardia, persistant sinusal bradycardia or AV block) and 10 infants had respiratory failure. All infants had elevated inflammatory biomarkers and received steroids or/and IVIG. Two infants died.ConclusionThe common presentation of MIS-N included cardiac aritmia and respiratory failure. Newborns with MIS-N may be at higher risk for adverse outcomes. Early diagnosis and treatment are important in these patients
A highly selective carbazole-based D-π-D-A fluorescence turn-off sensor for Fe3+ detection in aqueous media
No full textIn this study, N-hexyl-6-(4-methoxyphenyl)carbazole-3-carbaldehyde with donor-it-donor-acceptor (D-it-D-A) structure was designated as a probe N and its fluorescence sensor properties were investigated against 30 different analytes. Probe N in DMSO gave a structureless emission band with a maximum at 470 nm and a high photoluminescence quantum yield (80 %). In going from non-polar to polar solvents, the emission maximum of probe N red-shifted by 72 nm and Stokes shifts observed between absorption and emission spectra was 71 nm (3689 cm-1). It was found that the emission maximum of probe N at 470 nm was more significantly quenched by Fe3+ than by Fe2+ among the analytes studied. Probe N showed high selectivity and high sensitivity with a 0.8 nM limit of detection (LOD) against Fe3+ in the presence of competing analytes. The LOD value is the lowest value reported so far for the detection of Fe3+. Job's plot indicated a 2:1 ratio between probe N and Fe3+. 1H NMR and FT-IR provided further evidence that probe N complexed Fe3+ via the non-bonding electrons on the oxygen atoms of the aldehyde and methoxy groups. In practical applications, probe N successfully detected Fe3+. These results revealed that probe N could be an effective turn-off fluorescence sensor in the determination of Fe3+ in liquid environments
Türkiye’deki görme engelli ikiz müzisyenlerin öz kimlik gelişimi, öz saygı oluşumu ve psikolojik esenlikleri: Kerim-Selim Altınok örneği
No full textSelf-identity development is an umbrella concept that covers various theoretical themes. Self-esteem, on the other hand, reflects an individual’s overall evaluation of their feelings and ‘worth’. This manuscript aims to explore the identity development and self-esteem formation of Kerim Altınok (KA) and Selim Altınok (SA). The twin brothers are well-known and celebrated blind musicians in Türkiye. In Türkiye and elsewhere, blind people tend to experience significant life difficulties, and suffer from low self-esteem and dented self-identity. We used qualitative methods to conduct this study. Utilizing semi-structured questionnaire, we carried out in-depth-interviews with the twin brothers. Specifically, we focused on how the participants have constructed the notions of ‘Me’ and ‘I’, and successfully developed strong self-identity and high self-esteem. The first interview took place at a local restaurant in a leafy suburb of Istanbul in 2019. We conducted the rest of the interviews online because of the coronavirus pandemic outbreak in 2020-2021. We transcribed the interviews, and the data were subjected to thematic analysis. Our findings suggest that Kerim and Selim developed high self-esteem and strong self-identity over the decades despite becoming blind at a young age. They encountered and overcame major life challenges from childhood to adult life. Their life narratives are remarkable and there is a real opportunity to learn from their lived experience, and how they have developed strong self-identity and high self-esteem despite living with a primary disability.Öz kimlik gelişimi, çeşitli teorik temaları kapsayan bir şemsiye kavramdır. Öz saygı ise bireyin duygularının ve 'değerinin' genel değerlendirmesini yansıtır. Bu makale, Kerim Altınok (KA) ve Selim Altınok'un (SA) kimlik gelişimini ve öz saygı oluşumunu incelemeyi amaçlamaktadır. İkiz kardeşler, Türkiye'de tanınmış ve ünlü kör müzisyenlerdir. Türkiye'de ve diğer yerlerde, kör insanlar önemli yaşam zorlukları yaşama eğilimindedirler ve düşük öz saygı ve zedelenmiş öz kimlikten muzdariptirler. Bu çalışmayı yürütmek için nitel yöntemler kullandık. Yarı yapılandırılmış anketler kullanarak ikiz kardeşlerle derinlemesine görüşmeler gerçekleştirdik. Özellikle, katılımcıların ‘Bana’ ve ‘Ben’ kavramlarını nasıl oluşturduklarına ve güçlü bir öz kimlik ve yüksek öz saygıyı nasıl başarıyla geliştirdiklerine odaklandık. İlk görüşme, 2019'da İstanbul’un bir semtindeki yerel bir restoranda gerçekleşti. 2020-2021'deki koronavirüs salgını nedeniyle görüşmelerin geri kalanını çevrimiçi olarak gerçekleştirdik. Görüşmeleri yazıya çevirdik ve veriler tematik analize tabi tutuldu. Bulgularımız, Kerim ve Selim’in genç yaşta kör olmalarına rağmen, yıllar içinde yüksek öz saygı ve güçlü bir öz kimlik geliştirdiklerini göstermektedir. Çocukluktan yetişkinliğe kadar büyük yaşam zorluklarıyla karşılaşmış ve bunların üstesinden gelmişlerdir. Hayat hikayeleri dikkat çekicidir ve yaşanmış deneyimlerinden, birincil bir engelle yaşamalarına ragmen, nasıl güçlü bir öz kimlik ve yüksek öz saygı geliştirdikleri konusunda gerçek bir öğrenme fırsatı vardır
Characteristics of pain in patients with nmosd and mogad: Impact on mental health, sleep and quality of life
No full textNeuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein-associated disease (MOGAD) are autoimmune disorders frequently accompanied by chronic, often neuropathic, pain, which significantly impacts the quality of life, sleep, and mental health. This study evaluated the incidence and characteristics of neuropathic pain in 106 patients with NMOSD or MOGAD and assessed its effects on mental health, sleep quality, and overall quality of life. Using clinical evaluation and MRI findings to localize lesions, pain classification revealed that chronic pain was more common in NMOSD patients (78.4%) than in MOGAD patients (52.7%), with a significant impact on both groups. Patients with MOGAD who experienced neuropathic pain reported notably poorer sleep quality and higher anxiety and depression levels. Pain severity was strongly associated with spinal cord lesion length and thoracic location, particularly in MOGAD patients. Current treatments provide insufficient pain relief, highlighting the need for more effective management strategies. This study emphasized that neuropathic pain substantially diminishes both physical and mental well-being in NMOSD and MOGAD patients, highlighting the importance of personalized pain management approaches to improve quality of life and mental health in these populations
The experimental investigation of thermal and electrical properties of battery module used in electric vehicles
No full textBu tez kapsamında, 73 Ah kapasiteli kese tipi NMC kimyasına sahip lityum-iyon hücrelerden oluşturulmuş 6S3P elektrikli araç bataryası modülünün elektriksel ve çevresel faktörler değiştirilerek hem şarj hem de deşarj yönünde ısıl özellikleri incelenmiştir. Bu inceleme için farklı C-rate değerleri ve soğutma sıvısının sıcaklığı üzerinde değişiklikler yapılarak soğutma plakasının en etkili ve optimal soğutma performansı saptanmıştır. Yapılan deneyler kapsamında, akım değerleri sabit tutulup soğutma sıvısının sıcaklığını düşürdükçe (25°C, 15°C ve 5°C) batarya modülünün ulaştığı maksimum sıcaklık değeri azalmıştır ve soğutma sıvısının sıcaklık değeri sabit tutulup akım değeri azaltıldıkça (1.3 C-rate ve 0.8 C-rate) batarya modülünün ulaştığı maksimum sıcaklık değeri azalmıştır. Düşük C-rate değerleri ve düşük soğutma sıvısı sıcaklığı, batarya modülünün ısınmasını en performanslı şekilde engellemiştir. Ancak batarya modülünün istenilen sıcaklıkta tutabilmek için soğutmaya sağlanan fayda, harcanan enerji ve hücreler arası sıcaklık farkı dikkate alınarak soğutucu sıvı sıcaklığı optimize edilerek bu değer 5°C yerine 15°C olarak belirlenmiştir. Bu deneyler için 3D metal yazıcı kullanılarak ve eklemeli imalat yöntemi ile soğutucu plaka tasarımı ve prototip imalatı gerçekleştirildi. Bu kapsamda literatür incelendiğinde 3D metal yazıcı kullanılarak modül seviyesi soğutma analizleri için az sayıda deneysel çalışma bulunmaktadır. Batarya modülü içerisindeki hücrelerin merkezlerine ısıl çiftler yerleştirildi. Ölçümler yapabilmek adına termal kabin, DC güç ünitesi ve veri toplayıcı kullanıldı. Özetle birçok disiplinin bir arada bulunduğu ve farklı test ve ölçüm cihazlarının kullanıldığı deneysel temelli çalışma olmasından dolayı, bu tez ile elektrikli araç batarya tasarımlarına, ilgili diğer tezlere ve makalelere referans olacaktır.Within the scope of this thesis, the thermal properties of the 6S3P electric vehicle battery module, which is made of lithium-ion cells with a capacity of 73 Ah and pouch type NMC chemistry, were examined in both charging and discharging directions by changing the electrical and environmental factors. For this examination, the most effective and optimal cooling performance of the cooling plate was determined by making changes to different C-rate values and the temperature of the cooling liquid. Within the scope of the experiments, the maximum temperature value reached by the battery module decreased as the current values were kept constant and the temperature of the cooling liquid was reduced (25°C, 15°C and 5°C), and the maximum temperature value reached by the battery module decreased as the temperature value of the cooling liquid was kept constant and the current value was reduced (1.3 C-rate and 0.8 C-rate). Low C-rate values and low cooling liquid temperature prevented the heating of the battery module in the most efficient way. However, in order to keep the battery module at the desired temperature, the cooling liquid temperature was optimized by considering the benefit provided to cooling, the energy consumed and the temperature difference between the cells, and this value was determined as 15°C instead of 5°C. For these experiments, a cooling plate design and prototype manufacturing were carried out using a 3D metal printer and additive manufacturing method. In this context, when the literature is examined, there are few experimental studies for module level cooling analyses using a 3D metal printer. Thermocouples were placed at the centers of the cells in the battery module. Thermal cabin, DC power unit and data collector were used to make measurements. In summary, since it is an experimental based study where many disciplines come together and different test and measurement devices are used, this thesis will be a reference for other theses and articles related to electric vehicle battery designs
Master-slave architecture enhanced and improved gbo tuned cascaded pi-pdn controller for speed regulation of dc motors
No full textThis study introduces a novel master-slave architecture featuring an improved gradient-based optimizer (ImGBO) to effectively tune a cascaded proportional-integral (PI) and proportional-derivative with filter (PDN) controller specifically for DC motor speed regulation. The core novelty of this work lies in enhancing the traditional GBO algorithm by integrating an experience-based perturbed learning mechanism and an adaptive local search strategy, significantly enhancing its ability to balance exploration and exploitation during optimization. The proposed ImGBO-based cascaded PI-PDN controller is comprehensively evaluated against traditional GBO, recent metaheuristics and advanced proportional-integral-derivative (PID) and fractional-order PID (FOPID) controllers. Significant improvements were observed, with the proposed method demonstrating exceptionally short rise (0.0089 s) and settling times (0.0140 s), no overshoot, and minimal steady-state error (0.0017%). Stability analysis via pole placement and Bode plots affirmed the robust and stable operation of the controller, exhibiting a phase margin of 71.6640 degrees and infinite gain margin. These results strongly support the suitability and effectiveness of the ImGBO-based approach for precision-critical DC motor control applications
Impact of high pressure processing on the in vitro bioaccessibility of polyphenols in sour cherry (prunus cerasus l.) juice
No full textAs the demand for minimally processed food products with fresh-like characteristics continues to grow, nonthermal techniques are becoming increasingly popular. Fruit juices, due to their significant health benefits, are excellent candidates for nonthermal treatments aimed at preserving maximum nutritional value. Sour cherry (Prunus cerasus L.) juice (SCJ) is particularly rich in polyphenols, especially anthocyanins. This study comparatively assessed the impact of high-pressure processing (HPP) (300-400-500 MPa/5-10-20 min) on the content and in vitro bioaccessibility of total phenolics (TPC), flavonoids (TFC), monomeric anthocyanins (TMAC), antioxidant capacity (TAC), and individual polyphenolic compounds in SCJ. The findings revealed that both thermal pasteurization and HPP treatments significantly enhanced polyphenol bioaccessibility in SCJ compared to untreated samples. Thermal treatment resulted in the highest bioaccessibility levels for TMAC (82%), TAC (120%), and individual polyphenolic compounds (86%). HPP-treated samples exhibited greater TFC bioaccessibility (60-82%) than thermally pasteurized SCJ (51%), with samples processed at 500 MPa showing improved bioaccessibility across most phenolic fractions due to enhanced cell permeability and mass transfer. However, HPP generally reduced TAC bioaccessibility (60-78%) compared to the control (83%), except under high-pressure conditions (500 MPa for 20 min), highlighting the complex interplay between processing parameters and polyphenol stability
Classification and generation of soliton waves via convolutional neural networks
No full textThis study investigates the generation, identification, and classification of soliton waves by employing deep learning methods, specifically focusing on eliminating the uncertainty and inefficiency inherent in traditional trial-and-error approaches. Initially, an extensive dataset comprising sine, square, triangular, and soliton waveforms is created using a specialized experimental setup including a nonlinear transmission line (NLTL), a signal generator, and an oscilloscope. To enhance the robustness and generalization of the deep learning models, data augmentation techniques such as flipping, rotating, scaling, and cropping are applied. Among 20 evaluated pre-trained convolutional neural network architectures, DenseNet169 exhibited the highest accuracy and is selected for comprehensive training, validation, and testing. Results demonstrated the efficacy of DenseNet169, achieving a training accuracy of 0.988, validation accuracy of 1.000, and test accuracy of 0.984. This high level of performance underscores the potential of deep learning approaches to automate and optimize soliton wave identification and generation processes reliably
Third-order differential subordination and superordination results for p-valent analytic function involving fractional derivative operator
No full textWe introduce a concept that generalizes the fractional calculus (differentiation and integration) in the complex domain using the Mellin transform. Special cases that lead to the well-known classical forms are discussed. A real-case example, along with a corresponding plot, is provided for illustration. The fractional derivative mentioned above is utilized to present applications to the differential subordination results of Antonino and Miller, as well as the differential superordination results of Tang et al. for -valent analytic functions, ultimately leading to sandwich-type results. Finally, we highlight the potential application of this topic in fluid mechanics