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Plazma Ark Yöntemiyle Kaynaklanan 304 Serisi Çeliklerin Dayanım Performansı
No full textÖstenitik paslanmaz çelik, üstün mekanik ve korozyon performansına sahiptir ve birçok sektörde kullanılır. Kaynak, paslanmaz çelik yapıların üretiminde yaygın olarak kullanılan bir yöntemdir. Plazma transfer ark kaynağı, tungsten elektrotlar arasındaki elektrik arkı ile yapılan bir tekniktir. Bu araştırmada, AISI 304 plakalar plazma kaynağı kullanılarak kaynaklanmıştır. Birleşme arayüzeyi, taramalı elektron mikroskobu, optik mikroskop, enerji dağılımlı spektroskopi ve X-Ray diffraction ile analiz edilmiştir. Numunelerin mukavemet özellikleri, çekme testi ile değerlendirilmiştir. Numunelerin kırılma yüzeyleri SEM ile incelenmiştir. PTA yöntemi, AISI 304 plaka birleşme arayüzeyinde tam penetrasyon sağlamıştır. Kaydedilen dikiş genişlikleri S1 için 6 mm, S2 için 6,5 mm ve S3 için 7 mm'dir. Numuneler düşük ısı girdisi altında 336 MPa, orta ısı girdisi altında 360 MPa ve yüksek ısı girdisi altında 374 MPa mukavemet sergilemiştir. Tüm birleşimler iyi dayanım göstermiştir.Austenitic stainless steel is employed in various industrial sectors with its excellent mechanical and corrosion performance. Welding is a commonly used method in the production of stainless-steel structures. Plasma transferred arc welding (PTAW) is a technique in which an electric arc is fabricated and maintained between tungsten electrodes. In this research, AISI 304 plates were welded using plasma welding. The joint interface was analyzed through energy dispersive spectroscopy and optical microscopy. The strength properties of the samples were assessed via tensile testing. The fracture surfaces of samples were studied by SEM. The PTA method achieved complete penetration in AISI 304 plate joint. All joints showed good strength
Türkiye Yüzyılı Maarif Modelince Hazırlanan Sosyal Bilgiler 5. Sınıf Ders Kitabında Kadın
No full textTL-GWO: Fine-tuned transfer learning with grey wolf optimizer for accurate fundus image-based eye disease classification
No full textThis study introduces an automated diagnostic framework that detects diabetic retinopathy, glaucoma, and healthy retinas in color fundus images. It leverages several transfer learning (TL) backbones—DenseNet121, ResNet50, ResNet101V2, InceptionResNetV2, and Xception—augmented with additional dense layers, whose architecture and key training hyperparameters are optimized by the Grey Wolf Optimizer (GWO). To enhance image quality and improve feature visibility, Contrast Limited Adaptive Histogram Equalization (CLAHE) is applied during preprocessing, followed by data augmentation techniques such as rotations, shifts, and flips to reduce overfitting. The proposed framework systematically searches the hyperparameter space for optimal configurations, including layer depth, neuron count, activation functions, learning rate, and optimizers, eliminating the limitations of manual tuning. Experimental evaluations on the Eye Disease Image Dataset reveal that integrating GWO-driven optimization with TL significantly improves model generalization and robustness. ResNet101V2 achieved the highest performance with 89.32 % accuracy and an F1-score of 89.37 %, outperforming all other architectures across every evaluation metric. These findings demonstrate the potential of combining advanced TL strategies with metaheuristic optimization to develop reliable and scalable computer-aided diagnostic systems for ophthalmic disease detection
Relationship of Plasma Cell Infiltration Rates with 18F-FDG PET/CT Data and Hematological Parameters in Multiple Myeloma Multipl Myelomda Plazma Hücre İnfiltrasyon Oranlarının ve Hematolojik Parametrelerin 18F-FDG PET/CT Verileri Arasındaki İlişki
No full textObjectives: This study aimed to evaluate the relationship between the degree of bone marrow involvement, hematological parameters, and 18 F-fluorodeoxyglucose (18F-FDG)-positron emission tomography/computed tomography (PET/CT) data in patients diagnosed with multiple myeloma. Methods: A total of 71 patients [19 females, 52 males, mean age 67 (36-83) years] who were diagnosed with multiple myeloma between 2014 and 2021, had not received any treatment yet, and underwent 18F-FDG-PET/CT for staging were included in the study. Results: No significant correlation was observed between bone marrow standardized uptake value (SUV)max and plasma cell infiltration (p=0.07). However, we found that patients with visually increased bone marrow counts also had higher plasma cell infiltration rates (p=0.037). No significant correlation was found between plasma cell infiltration rates and bone marrow SUVmax and systemic inflammatory index (SII) (p=0.187 and p=0.446, respectively). However, there was a significant correlation between the SUVmax of lytic lesions showing increased18F-FDG uptake in bone and SII (p=0.025, r=0.330). Conclusion: We believe that 18F-FDG PET/CT may be an advantage over bone marrow biopsy in the diagnosis and evaluation of multiple myeloma recurrence and may prevent repeated bone marrow biopsies
Synthesis of Thiazole-methylsulfonyl Derivatives, X-ray Study, and Investigation of Their Carbonic Anhydrase Activities: In Vitro and In Silico Potentials
No full textThis study focused on the design, synthesis, chemical characterization, and potential inhibitory study of thiazole-methylsulfonyl derivatives against carbonic anhydrase enzymes. The synthesized compounds, with the characteristics of both the thiazole ring and methyl sulfonyl group, were synthesized through a two-step scheme, and their structures were confirmed through NMR spectroscopy and HRMS. Additionally, the structure of compound 2b was elucidated by an X-ray study. An enzyme inhibition assay was performed to assess their biological activity against carbonic anhydrases, and the compounds showed promising results against carbonic anhydrases I and II, highlighting their potential for specificity and targeted therapy. The effects of these molecules on in vitro enzyme activities were investigated by spectrophotometric methods. For this purpose, the concentrations (IC50 values) of compounds that inhibited the biological activities of carbonic anhydrase isoenzymes (hCA I and hCA II) by 50% were calculated. The IC50 values were found between 39.38-198.04 μM (AAZ IC50 = 18.11 μM) for hCA I and 39.16-86.64 μM (AAZ IC50 = 20.65 μM). Molecular docking studies have shown that compounds 2a and 2h exhibit stable interaction networks with targeted enzymes. The combinations of both studies, enzyme inhibition assay and molecular docking studies, thus enlighten the significance of these compounds for further optimization for pharmacological profiling and for developing therapeutic agents against carbonic anhydrase. Moreover, the study provides insight for future research on the synthesis of heterocyclic compounds against carbonic anhydrase for therapeutic applications
The relationship between the child's problematic media use and the parental reading belief and smartphone addiction.
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