Sakarya University of Applied Sciences AXSIS
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Production of ZnAlO semiconducting materials for thermoelectric generators in potential aerospace applications
No full textThe primary objective of this research is to synthesize and develop n-type ZnAlO semiconducting thermoelectric materials for application in thermoelectric generators within the aerospace sector. ZnAlO powders were synthesized utilizing the sol-gel method. The pH and turbidity of the prepared solutions were measured using a pH meter and a turbidimeter, respectively. After drying at 200 degrees C for 9 h to eliminate moisture and volatile substances, the dried powders were subsequently calcined at 600 degrees C for 4 h in an air atmosphere, resulting in the formation of ZnAlO materials. These powders were then compacted into pellets and underwent thermal treatment at 1350 degrees C for 36 h to produce bulk n-type semiconductor samples. Thermal, structural, microstructural, and thermoelectric characterization of the synthesized materials was conducted employing DTA-TG, XRD, XPS, SEM, and thermoelectric measurement devices. The study concludes that the synthesized n-type semiconducting ceramic materials exhibit properties conducive to efficient thermoelectric generator production
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 (1.33x10(-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
Zircoborate glass-ceramic composite reinforced with aluminum oxynitride: Microstructural evolution, physical properties, and charged radiation attenuation analysis
No full textThis study used the powder metallurgy method to create aluminum oxynitride (AlON)-reinforced zircoborate glass-ceramic composites. The solid-phase reaction method was used to synthesize AlON powder, which was then added to Zr-based glass-ceramic in different amounts (0, 4, and 8 % by weight) to make it stronger and harder. The prepared materials were characterized for their structural, physical, and radiation shielding properties. The density of GZr8 (AlON-free) had a value of 2.9 g/cm3 , and the sintered glass-ceramic density with 4 % wt. AlON reinforcement (GZr8Al4) reached 3.05 g/cm3 . The highest density of 3.11 g/cm3 was obtained for the GZr8Al8 sample with 8 % AlON wt. The Vickers hardness for GZr8, GZr8Al4, and GZr8Al8 was measured to be 4.89, 5.94, and 6.33 GPa, respectively. The AlON-reinforced GZr8 samples had fast neutron (FN) removal cross-sections of 0.0796 cm− 1 and 0.0824 cm− 1 for AlON content of 4 and 8 wt%, respectively. Generally, the coherent scattering cross-section (σcoh), incoherent scattering cross-section (σinc), and absorption cross-section (σabs) of thermal neutrons (TNs) increase from 0.047856 cm− 1 , 0.02072 cm− 1 , and 0.01498 cm− 1 , respectively for GZr8 to 0.53124 cm− 1 , 0.02074 cm− 1 , and 0.01795 cm− 1 , for GZr8Al8. AlON was proven to improve the ability of the Zrbased glass-ceramics to attenuate FNs and TNs. Stopping powers of electrons, protons, alpha particles and carbon ions increase with the AlON content of the materials. Comparatively, the range of charged radiation in AlON-rich samples is lower. The inclusion of AlON in the matrix of the Zr-based glass-ceramics makes it more efficient at absorbing charged radiation and can be used in ion beam or hadron therapy, ion beam analysis, or other charged radiation environments as an absorber
Integrated Process Planning, Scheduling, and Due-Date Assignment
No full textTraditionally, the three most important manufacturing functions are process planning, scheduling, and due-date assignment, which are handled sequentially and separately.This book integrates these manufacturing processes and functions to increase global performance along with manufacturing and production cost savings. Integrated Process Planning, Scheduling, and Due-Date Assignment combines the most important manufacturing functions to use manufacturing resources better, reduce production costs, and eliminate bottlenecks with increased production efficiency. The book covers how the integration will help eliminate scheduling conflicts and how to adapt to irregular shop floor disturbances. It also explains how other elements, such as tardiness and earliness, are penalized and how prioritizing helps improve weight performance function. This book will draw the interest of professionals, students, and academicians in process planning, scheduling, and due-date assignment. It could also be supplemental material for manufacturing courses in industrial engineering and manufacturing engineering departments. © 2024 Halil İbrahim Demir, Abdullah Hulusi Kökçam, Caner Erden
KIYI UZUNLUĞUNUN DİĞER DENİZ GÜCÜ UNSURLARI İLE İLİŞKİSİ: KUZEY ATLANTİK ANLAŞMASI ÖRGÜTÜ (NATO) ÜLKELERİ ANALİZİ
No full textBu çalışmada deniz gücü unsurları niteliğindeki kıyı uzunluğu ile savaş gemisi sayısı, ticari gemi sayısı, liman sayısı, su ürünleri ihracat gelirleri ve gemi inşa sektörü ihracat gelirleri arasında bir ilişki olup olmadığı araştırılmıştır. Bu çerçevede, denize kıyısı olan 26 adet NATO ülkesinin belirtilen deniz gücü unsurlarına yönelik verileri toplanmış ve Spearman korelasyonu ile analiz edilmiştir. Gerçekleştirilen analizde kıyı uzunluğu ile belirtilen diğer deniz gücü unsurları arasında çeşitli korelasyon skorlarında, pozitif yönde ve anlamlı ilişkiler tespit edilmiştir. Çalışma sonucunda coğrafi deniz gücü unsurları ile askeri ve ekonomik deniz gücü unsurlarının birbirleriyle ilişkili olduğu ve toplam deniz gücü kapasitesinin gelişimi için bu unsurların bir bütün olarak geliştirilmesi gerekliliği ortaya koyulmuştur
Detailed Investigation of Plasticized PMMA Dielectric for Improved Performance of Organic Field-Effect Transistors
No full textIn this study, organic field-effect transistors (OFETs) were fabricated using plasticized poly(methyl methacrylate) (PMMA) as the gate dielectric and copper phthalocyanine (CuPc) as the active layer. Propylene carbonate (PC) was used as a plasticizer material. The dielectric properties of the plasticized PMMA were investigated in detail and the OFET parameters were examined. The effective capacitance (C-i) of plasticized PMMA was measured as similar to 500 nF cm(-2) (at 100 Hz), which is almost 70 times higher than that of pure PMMA. This increase in effective capacitance led to significant improvements in various key parameters of the fabricated OFETs. High hole field-effect mobility values (0.81 cm(2) V-1 s(-1)), low threshold voltages (similar to +/- 0.1 V), and low operating voltages (0 to +/- 0.8 V) were achieved by using the plasticized PMMA dielectric. The temperature dependence of the fabricated OFETs was also investigated, and the activation energy of CuPc was estimated as 29.3 meV. The plasticized OFETs demonstrated excellent stability over 3600 measurement cycles carried out in an ambient atmosphere. This demonstrated stability of the fabricated OFETs reinforces the practical feasibility of this material combination strategy, positioning it as a key advancement in the field of solution-processable gate dielectrics
Effects of plyometric trainings applied with the principle of progressive and unprogressive volume-based overload on physical performance on young male football players
No full textBu çalışma genç erkek futbolcularda aşamalı ve aşamasız hacim temelli aşırı yük prensibiyle uygulanan pliometrik antrenmanların fiziksel performansına etkisini inceleneceği amacıyla yapılmıştır. Araştırmanın katılımcı grubu Rize ilinin Pazar ilçesindeki futbol kulübünden ve daha önce veya şu anda düzenli kuvvet veya pliometrik antrenman yapmamış yirmi dört genç (10-11 yaş arası) erkek futbolcu bu çalışma için gönüllü oldu. 24 erkek, kontrol grubu (n= 8, KG), aşamalı pliometrik grup (n= 8, APG) ve aşamasız pliometrik grup (n= 8, ASPG) olmak üzere tesadüfi yönteme göre üç homojen gruba ayrılmıştır. Genel özellikleri ise, (Ortalama ± Standart Sapma), kontrol grubunda yaş: 10.2 ± 0.35 yıl, beden ağırlığı: 31.38 ± 2.61 kg, boy: 138.2 ± 5.20 cm, zirve boy uzaması: 13.93 ± 0.43 yıl,olgunluk yaşı: -3.81 ± 0.34 yıl şeklinde. Aşamalı pliometrik grubunda yaş: 10.25 ± 0.46 yıl, beden ağırlığı: 39.38 ± 2.61 kg, boy: 143.6 ± 2.26 cm, zirve boy uzaması: 13.96 ± 0.39 yıl, olgunluk yaşı:-3.71 ± 0.33 yıl şeklinde. Aşamasız pliometrik grubunda yaş: 10.5 ± 0.53 yıl, beden ağırlığı: 35.37 ± 9.57 kg, boy: 139.0 ± 7.01 cm, zirve boy uzaması: 14.11 ± 0.33 yıl, olgunluk yaşı: -3.61 ± 0.86 yıl şeklinde dağılmıştır. Çalışma toplam 6 haftada gerçekleştirilmiştir. 6 hafta boyunca 24 ayrı egzersiz uygulanmış ve yüklenmenin şiddeti, süresi ve tekrar sayısı gruplara yapılacak olan deneylere göre değişiklik göstermiştir. Aşamalı ve aşamasız gerçekleştirilen pliometrik antrenmanların etkilerinin belirlenmesi için ön ve son testler gerçekleştirilmiştir. Bu testler 3 günde gerçekleştirilmiştir. Birinci gün; dikey sıçrama testi, ileriye sıçrama testi ve 20 cm drop sıçrama testi, İkinci gün; ayrı ayrı olarak 5,10,15 ve 20 metre sürat testi ve üçüncü gün yön değiştirme testi ve yo-yo dayanıklılık testi gerçekleştirilmiştir. Dayanıklılık testi haricindeki tüm testler 3 kez tekrarlanmış ve analiz için en iyi değer kullanılmıştır. Tüm İstatistiksel analizler, anlamlılık seviyesi p < 0.05 olarak ayarlanarak IBM SPSS Statistics 22.0 (SPSS, Inc., Chicago, IL) kullanılarak yapıldı. Sonuç olarak, Futbolcuların 6 hafta boyunca yaptıkları çalışmalar sonucunda aşamalı pliometrik antrenman grubunda dominant bacak ileri sıçrama, nondominant bacak ileri sıçrama, drop jump testlerinde aşamasız pliometrik grubuna ve kontrol grubuna göre anlamlı faklılığa(p<0.05) düzeyinde rastlanmıştır. Çift bacak ileri sıçrama, 5,10,15,20 metre sprint, illinois test ve yo-yo r1 intermittent testindeki verilerde de artış olmuş olmasına rağmen (p<0.05) düzeyinde aşamalı pliometrik grubun aşamasız pliometrik grup ve kontrol grubu açısından anlamlı farklılık bulunmamıştır. Anahtar Kelimeler: Pliometrik Antrenman, Aşamalı ve Aşamasız Yüklenme, Sprint, Sıçrama, Dayanıklılık, Çeviklik
Health Effects of Tai Chi Qigong Practices and Its Reflections on Nursing Practices: Systematic Review
No full textThis systematic review was conducted to examine the effects of Tai Chi Qigong (TCQi) practices on health and their reflections on nursing practices. A systematic review of randomized controlled trials for TCQi included quantitative English-language studies from 2012 to 2021 using 7 electronic databases (PubMed, CINAHL, Ebrary, Elsevier, Science Direct, Google Scholar, and Scopus). Seven studies were selected to review the effects of TCQi exercise applied by nurses in the presence of symptoms that worsen the general health status of individuals or develop secondary to chronic diseases: sleep disturbance, depression, fatigue symptoms, deterioration in the quality of life, worsening of self-care behaviors, and stress symptoms. Evidence on the use of the TCQi practices is limited, and the proof of its preferability over other integrative methods in care practices by nurses is not at the desired level. Therefore, this systematic review emphasizes further research on the risks and benefits of TCQi practices as with other integrative methods, so that TCQi practices, which are easier to apply than other mind-body practices, can be preferred by nurses. Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved
Automated classification of choroidal neovascularization, diabetic macular edema, and drusen from retinal OCT images using vision transformers: a comparative study
No full textClassifying retinal diseases is a complex problem because the early problematic areas of retinal disorders are quite small and conservative. In recent years, Transformer architectures have been successfully applied to solve various retinal related health problems. Age-related macular degeneration (AMD) and diabetic macular edema (DME), two prevalent retinal diseases, can cause partial or total blindness. Diseases therefore require an early and accurate detection. In this study, we proposed Vision Transformer (ViT), Tokens-To-Token Vision Transformer (T2T-ViT) and Mobile Vision Transformer (Mobile-ViT) algorithms to detect choroidal neovascularization (CNV), drusen, and diabetic macular edema (DME), and normal using optical coherence tomography (OCT) images. The predictive accuracies of ViT, T2T-ViT and Mobile-ViT achieved on the dataset for the classification of OCT images are 95.14%, 96.07% and 99.17% respectively. Experimental results obtained from ViT approaches showed that Mobile-ViT have superior performance with regard to classification accuracy in comparison with the others. Overall, it has been observed that ViT architectures have the capacity to classify with high accuracy in the diagnosis of retinal diseases. © The Author(s) 2024
Kazakistan'ın Gastronomi Turizmi Potansiyeli: Swot Analizi Üzerine Bir Araştırma
No full textThis study aims to determine the gastronomy tourism potential of Kazakhstan and to evaluate its strengths, weaknesses, opportunities, and threats within the scope of gastronomy tourism. The universe of the study consists of tourism stakeholders serving in Kazakhstan. Data were collected from 15 participants operating in various tourism enterprises in the Almaty region using the interview technique. As a result of the study, when considering alternative types of tourism, it has been observed that Kazakhstan has significant potential for gastronomy tourism. It has been determined that the strengths of Kazakhstan's gastronomy tourism should be efficiently exploited, improvements should be made to address weaknesses, effective actions should be developed to capitalize on opportunities, and measures should be taken to mitigate threats. Suggestions are presented to use Kazakhstan's strengths identified in the SWOT analysis more effectively and efficiently, addressing its weaknesses, and transforming its threats into opportunities