Sakarya University of Applied Sciences AXSIS
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Microstructure and Surface Roughness Connection on Machined Ductile Iron: An Experimental Determination
No full textDuctile iron is useful for a variety of engineering challenges because of its ductility and high strength. Hence, it is an excellent option if machining is required. After milling operations, however, various surface characteristics could be created, and surface roughness could be assessed. On the other hand, machined surface roughness is constrained by production requirements. As a result, the association between surface roughness and machining parameters has been studied in the literature. Studies that focus on the relationship between surface roughness and microstructure in the context of material qualities are also available. In this study, an experimental investigation of a part made of EN-GJS-600-3 material took into account the significance of the interaction between microstructure and surface roughness. In addition to machining parameters, surface roughness, hardness (Brinell Hardness), and microstructure of machined surfaces are taken into consideration. The findings show that surfaces with pearlitic compositions are highly abrasive. Hardness rose along with an increase in the pearlitic phase. The number of spheres and surface roughness follow the same trend
Improving Tuberculosis Diagnosis using Explainable Artificial Intelligence in Medical Imaging
No full textThe integration of artificial intelligence (AI) applications in the healthcare sector is ushering in a significant transformation, particularly in developing more effective strategies for early diagnosis and treatment of contagious diseases like tuberculosis. Tuberculosis, a global public health challenge, demands swift interventions to prevent its spread. While deep learning and image processing techniques show potential in extracting meaningful insights from complex radiological images, their accuracy is often scrutinized due to a lack of explainability. This research navigates the intersection of AI and tuberculosis diagnosis by focusing on explainable artificial intelligence (XAI). A meticulously designed deep learning model for tuberculosis detection is introduced alongside an exploration of XAI to unravel complex decisions. The core belief is that XAI, by elucidating diagnostic decision rationale, enhances the reliability of AI in clinical settings. Emphasizing the pivotal role of XAI in tuberculosis diagnosis, this study aims to impact future research and practical implementations, fostering the adoption of AI-driven disease diagnosis methodologies for global health improvement
How does harvest time affect the major fatty acids and bioactive compounds in hazelnut cultivars (Corylus avellana L.)?
No full textThis study was conducted to investigate the effects of harvest time on the protein, oil, fatty acids and bioactive compounds in hazelnut cultivars (Corylus avellana L. cvs. 'Tombul', 'Palaz', 'Çakildak', 'Okay 28' and 'Allahverdi'). The harvest was carried out at 7 different periods with weekly intervals from 20 July to 31 August. As the harvest time progressed, increases and decreases were detected in protein, oil, fatty acids and bioactive compounds. The highest oil content was measured in the H5 and H6 harvest periods. The highest content was determined in H3 for oleic acid. Higher total phenolics, total flavonoids and antioxidant activity were obtained in the first 3 harvest periods than in the other periods. The present findings revealed that the protein, fatty acids and bioactive compounds in hazelnut cultivars may differ according to the harvest time. The results obtained will provide clearer ideas to both the industry and the producers about the optimum harvest time for the intended use of these cultivars. © 2024 CSIC
Rabbit muscle pyruvate kinase activators: Synthesis, molecular docking and theoretical studies of N-substituted sulfonamide derivatives
No full textPyruvate kinase (PK) activators have potential therapeutic applications in diseases such as sickle cell anemia. In this study, N-Substituted sulfonamide derivatives of 1,4-dihydropyridines were synthesized and evaluated as PK activators in vitro and using molecular docking studies. The compounds were synthesized by reacting dicarbonyl compounds with ammonium acetate, 5-nitrobenzaldehyde, and alumina sulfuric acid (ASA), followed by reduction and sulfonylation. The structures of the compounds were analyzed using spectroscopic techniques. DFT calculations provided insights into the electronic properties. Molecular docking of the compounds into the active site of PK showed favorable binding interactions. ADME evaluation indicated suitable solubility, BBB permeation, and lack of CYP450 inhibition. Overall, this study demonstrates the potential of new hybrid 1,4-dihydropyridine substituted sulfonamides as PK activators for further development. According to AC50 values, the compound (DTSsingle bondFsingle bond7, 0.97 μM) is about 100-fold higher affective than the clinically used sulfonamide compound (AC50 = 90 μM) for PK
Modified Gold Nanoparticles Modulated Fluorescence and Singlet Oxygen Generation of Pheophorbide a as an Effective Platform for Photodynamic Therapy against Staphylococcus aureus
No full textThe paper reports on the synthesis and evaluation of photochemical properties of gold nanorods (Au−NRs) coated with PEG with a thiol (−SH) group or SiO2 and their physical mixtures with pheophorbide a. Also biological activity of these systems was tested in photodynamic therapy directed towards Staphylococcus aureus. The potential additive effect between differently functionalized Au−NRs and the dye pheophorbide a was also studied. The efficiency of singlet oxygen generation varied considerably depending on the type of PEG polymer used for coating NRs and was the highest, of 65%, for the polymer PEG (10k) and the Au−NRs concentration of (1.33×10−11 M). For the other studied PEGs (2k, 5k) and the same concentration of NRs, a decrease in the singlet oxygen generation efficiency was observed. The most effective against Gram-positive bacteria were the mixtures of PEG-coated Au−NRs with pheophorbide a, exposed to irradiation at 405 nm and 660 nm, which provided a >5.8 log reduction in the bacteria growth. However, no strong bactericidal effect was noted in the case of irradiation with 525 nm. © 2024 Wiley-VCH GmbH
Effect of bismuth oxide on radiation shielding and interaction characteristics of polyvinyl alcohol-based polymer: Potential use in medical apron design
No full textThis study evaluated radiation shielding and interaction characteristics of polyvinyl alcohol (PVA) polymer separately doped with 10% and 20% Bi2O3 respectively for medical apron design and shielding special electronic installations. Prepared samples were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The EDS results showed that Carbon (C), Oxygen (O), and bismuth (Bi) elements were the predominant elements present in the prepared samples. The SEM result displaced surface irregularities due to a special bonding matrix between PVA and Bi2O3. Mass attenuation coefficient (MAC), effective atomic number (Zeff), Half value layer (HVL), Mean free path (MFP), Fast neutron removal cross-section (R), Total Mass Stopping Power (TSP), and photon Range (R) of the prepared polymer composites (PV-1Bi and PV-2Bi) were evaluated with XCOM and PHITS computer programs. Results showed that the MAC of the prepared polymer samples was significantly higher than some recently developed composites at 0.662 MeV and 1.25 MeV gamma energy. Therefore, polyvinyl alcohol (PVA) polymer doped with Bi2O3 should be deployed in medical apron design and shielding special electronic installations where flexibility and high adhesion abilities are crucial
The dielectric characteristics of spray deposited α-Si3N4:ZnO thin films: The nitride effect on frequency-dependent capacitance and conductance profiles
No full textThe study focused on the effect of α-Si3N4 doping on the electrical/dielectric properties of ZnO thin films. Both α-Si3N4 doped and additive-free ZnO thin films were coated on p-Si substrates via a spray deposition method to achieve this. The electrical (current density (J)-voltage (V)) and dielectric properties (capacitance (C), conductance (G), dielectric loss (tanδ), reel/imaginary part of dielectric permittivity (ε′ and ε″) and electric modulus (M′ and M″)) were determined for all samples by using dielectric spectroscopy (DS) method. On the other hand, scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS) analysis were performed to evaluate microstructure, X-ray diffraction (XRD) was used to define chemical composition and atomic-force microscopy (AFM) analysis was carried out to characterise the topology of the coating layers. The thickness/surface roughness was obtained as ∼82.5 nm/10.6 nm for undoped and ̴ 99.5 nm/10.4 nm for nitride-doped samples, respectively. The maximum capacitance value (C) was obtained as 275 pF at −3.0V and 200 Hz, and the optimal conductance (G) value was also found as 45 μS around 4.0V and 1 MHz in the nitride-doped sample. The average of α and τ values was calculated as 5.67 × 10−5 s, 0.146 and 4.49 × 10−5 s, 0.081 for nitride-doped and undoped ZnO, respectively. The increase in performance can be attributed to the homogeneous and almost equally-size distribution of the ZnO grain growth which is strongly controlled by α-Si3N4. © 2024 Elsevier Masson SA
Determinants of organizational stress: A research the framework of attribution theory
No full textStress, which has various dimensions, is a reaction that can disrupt the daily routines of living things in terms of physiology and psychology. Organizational stress is a situation that can cause disruption in the joint work of people focused on the same goal. Stress experienced in organizations is considered reasonable up to certain levels. However, an intense stress environment can lead to a number of problems such as poor performance, communication disorders, and desire to leave work. Identifying stress sources and examining their causes in depth is of great importance in preventing intense stress and keeping stress at a reasonable level. Identifying organizational stress sources and their causes will provide strategic convenience for managers and enable businesses to achieve organizational success. This research is aimed to determine the sources of organizational stress and to associate the stress dimensions that stand out as a result of the research with attribution behavior. Within the scope of the research were examined data of 590 hotel employees. Data were analyzed with the SPSS Programme. The dimensions of organizational stress were determined by Explanatory Factor Analysis. As a result of the research, stress originating from the manager and employee relations, which is one of the prominent dimensions of organizational stress, has been associated with external attribution behavior. Stress stemming from organizational structure, which is another prominent dimension, has been associated with internal attribution behavior. For managing the external attribution behavior, it is necessary to provide appropriate working conditions within the enterprise. For managing internal attribution behavior, an effective communication environment should be established
Therapeutic recreation in the elderly: Improving quality of life by improving some selected physical and motor skills with hippotherapy
No full textBu çalışma, yaşlanan nüfusun artan oranları ve yaşlılara yönelik sağlık ve yaşam kalitesini artırma ihtiyacı bağlamında terapötik binicilik ve hippoterapinin önemini vurgulamaktadır. Yaşlı bireylerin fiziksel, motorik ve denge becerilerini geliştirmek ve yaşam kalitesini artırmak amacıyla bu terapi yöntemlerinin etkinliğini daha fazla araştırmak için daha fazla kaynak tahsis edilmesi ve bu alandaki literatürün genişletilmesidir. Ayrıca, bu terapi yöntemlerinin yaşlıların günlük yaşam aktivitelerine katılımını, yeni beceriler öğrenmelerini ve sosyal izolasyonu azaltmalarını teşvik etme potansiyelini göz önünde bulundurarak, bu terapilerin yaşlıların yaşam kalitesini ve bağımsızlığını artırma amacıyla daha yaygın bir şekilde uygulanmasını desteklemekteyiz. Yaşlı bireylere uygulanan fiziksel, motorik ve denge ölçümlerinin hippoterapi ve terapötik binicilik verileri ile yaşam kalitesine etkisinin araştırılması hedeflenmiştir. Çalışmaya İstanbul ve Kocaeli'ndeki faklı Atlı Spor Kulübü, Kocaeli Üniversitesi (KOU) Fizik Tedavi Anabilim Dalı ve Kartepe Atçılık MYO'da 65-85 yaş aralığında 18 yaşlı birey dahil edildi. Bu yaşlı bireylerin 9 kontrol grubu, 9 ise deney grubu olarak değerlendirildi. Yaşlığa bağlı tedavileri devam eden bireylere, fiziksel, motorik ve denge testleriyle birlikte terapötik ve hippoterapi uygulamaları yapılarak yaşlı bireylerin yaşam kalitelerinin etkisi değerlendirildi. Yaşlı bireylerin testlerine uygun olarak Short Form 36 (SF-36) Yaşam Ölçeği, Short Kazt ADL Günlük Yaşam Ölçeği, Berg -Balans Denge Ölçeği, EQ-5D Öz Bildirim Ölçeği ve Time and Go (TUG) testleri yapıldı. Verilerin analizinde eşleştirilmiş gruplar t-testi kullanılmış olup anlamlılık p<.05 olarak kabul edilmiştir. Bu testler sonuçlarında yaşlı bireylere saha çalışmalarında 6 hafta boyunca haftada 3 gün ve 30 veya 45'şer dakikalık atla terapi yaptırılarak fiziksel ve denge becerilerinin yaşam kalitelerinin etkisi olduğu belirlendi. Bu çalışmanın sonuçlarına göre kontrol grubundaki yaşlı bireylerin deney grubundaki yaşlı bireylere göre yaşam kalitelerinin daha düşük olduğu tespit edilmiştir. Bununla birlikte hippoterapi ve terapötik binicilik yapan yaşlı bireylerin yaşam kalitelerinin arttığı yönde etkilemiştir. Sonuç olarak yaşlı bireylerin yaşam kalitelerini arttırmak için düzeli olarak atlarla temas etmeleri ve uygun atlara binmeleri yaşam kalitelerini arttırmada avantaj sağlayacağı yorumu yapılabilir. Anahtar Kelimeler: Yaşlı bireyler, Yaşam Ölçekleri, Terapötik Binicilik, Hippoterapi
Orchard-Based Variations in Oil Content, Fatty Acid Composition, and Bioactive Compounds in ‘Tombul’ and ‘Palaz’ Hazelnut (Corylus avellana L.) Cultivars
No full textBlack Scurf is one of the destructive fungal diseases of potato crops caused by fungus Rhizoctonia solani. Cultural practices and fungicide applications are insufficient in effectively combating the pathogen, while utilizing resistant cultivars has become one of the most economical and effective way to control disease. About ten commercial potato varieties were screened out against the disease by artificially inoculating the plants with R. solani and these potato varieties were grouped based on disease incidence and disease severity. Four varieties (Ronoldo, Rubi, Challenge, and Sadaf) were grouped as resistant, three varieties (SH-5, Sante and Astrex) as moderately susceptible and three varieties (Karoda, Mosica and Simply red) as susceptible with significantly highest disease incidence (P ≤ 0.05). Disease also reduced number and size of tubers, while the disease incidence showed negative (P < 0.001) correlation with chlorophyll and protein contents, and activities of catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) enzymes. It was concluded that a combination of phenotypic and physiological indices could be used to identify black scurf resistance in potatoe