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Investigation of the effect of different MnCr amount on mechanical and microstructural properties of Al-Mg-Si alloys
No full textBu çalışmada, döküm ve homojenizasyon işlemleri sonrasında
yüksek ve düşük MnCr içeriğine sahip Al-Mg-Si alaşımlarının
farklı Mn ve Cr oranlarının mikroyapı ve mekanik özellikler
üzerindeki etkileri incelenmiştir. Çalışma kapsamında, çeşitli Mn
ve Cr oranlarına sahip biyetler dökülmüş ve ardından
homojenizasyon ısıl işlemi uygulanmıştır. Homojenizasyon
işlemi sonrasında üretilen bu alaşımların mikroyapı ve mekanik
özelliklerini değerlendirmek için çekme testi, sertlik ölçümü,
Optik Emisyon Spektrometresi ve Taramalı Elektron Mikroskobu
analizleri yapılmıştır. Mikroyapı analizlerinde, yüksek MnCr
içeriğinin daha homojen ve ince taneli bir yapı sağladığı
gözlemlenmiştir. Homojenizasyon işlemi sonrasında, αAl(Mn,Cr)Si dispersoidlerinin yoğunluğu artmış ve bu
dispersoidler mekanik özelliklerin iyileşmesine katkıda
bulunmuştur. Mekanik test sonuçları yüksek Mn/Cr içeriğine
sahip alaşımların daha yüksek akma ve çekme mukavemeti ile
daha yüksek sertlik değerlerine sahip olduğunu göstermiştir.
Elde edilen sonuçlar Al-Mg-Si alüminyum alaşımlarının
performansını optimize etmek için Mn ve Cr mikroalaşımlarının
önemli olduğunu vurgulamaktadır.In this study, the effects of different Mn and Cr ratios on the
microstructure and mechanical properties of Al-Si-Mg alloys
with high and low MnCr content after casting and
homogenization processes were investigated. Within the scope
of the study, billets with various Mn and Cr ratios were cast and
then homogenization heat treatment was applied. Tensile
testing, hardness measurement, Optical Emission Spectrometry
(OES) and Scanning Electron Microscopy (SEM) analyses were
performed to evaluate the microstructural and mechanical
properties of these alloys produced after homogenization.
Microstructure analysis showed that higher MnCr content
resulted in a more homogeneous and fine-grained structure.
After homogenization, the density of α-Al(Mn,Cr)Si dispersoids
increased and these dispersoids contributed to the
improvement of mechanical properties. Mechanical test results
showed that alloys with higher Mn/Cr content have higher yield
and tensile strengths and higher hardness values. The obtained
results emphasize the importance of Mn and Cr microalloys to
optimize the performance of Al-Mg-Si aluminum alloys
Protective role of pinocembrin in a rat model of intestinal ischemia-reperfusion injury
No full textPurpose: To determine whether pinocembrin (PC) confers protective effects against experimentally induced intestinal ischemiareperfusion (I/R) injury in rats. Methods: Thirty Wistar albino rats were randomly divided into three groups (n = 10 each): sham (underwent laparotomy only); I/R (superior mesenteric artery occlusion for 60 min followed by 60 min reperfusion); and I/R + PC (5 mg/kg PC intraperitoneally before ischemia and again prior to reperfusion). Total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in both plasma and intestinal tissue. Histopathological evaluation was performed using hematoxylin and eosin staining and a modified Chiu scoring system. Results: Although TAC values did not show significant intergroup differences (p > 0.05), TOS and OSI values were significantly lower in the I/R + PC group than in the I/R group (p < 0.05). Histologically, the I/R + PC group displayed noticeably reduced mucosal damage compared to the untreated I/Rgroup. These results suggestthat PCalleviates oxidative stress and improves histological outcomes in intestinal I/R. Conclusion: PC exhibits a protective effect against intestinal I/R injury by decreasing oxidative stress and preserving tissue architecture. Further studies are warranted to optimize PC's dosing, timing, and mechanistic actions for clinical application
Application of filtration in sugar refining
Get PDFThe sugar manufacturing sector, reliant on sugarcane syrup, holds considerable economic and technical importance. Its processes involve purifying, decolorizing, and crystallizing sugarcane juice, traditionally achieved through methods like defecation, sulphation, phosphatation, and carbonation. Achieving a consistently high level of clarity and low color in the juice production process is a challenging endeavor. The challenge becomes significantly more difficult due to variations in the incoming juice properties resulting from differences in cane variety, soil composition, growing conditions, weather fluctuations, and seasonal variations. While conventional methods have served well historically, evolving environmental regulations and the need for enhanced sugar quality at reduced costs demand adaptation. Novel techniques like membrane filtration, particularly promising for its potential to improve clarity and reduce color, are gaining attraction. The sugar industry has had a longstanding interest in using membrane filtration to improve quality and as a pre-treatment for producing value-added products. Membrane filtration offers the potential for improved juice quality, providing clearer juice with reduced viscosity and noticeable color removal. Ultrafiltration of clarified sugarcane juice can be achieved through either spiral wound or flat sheet filtration systems utilizing polymeric membranes, or through tubular filtration systems employing ceramic membranes. This chapter comprehensively assesses the diverse applications of filtration techniques, particularly focusing on membrane technology, within the sugar industry. The aim is to meticulously explore the efficacy and potential of various filtration methods, notably membrane technology, in optimizing processes within the sugar production sector, thereby enhancing quality, reducing environmental impact, and potentially uncovering avenues for innovation and cost efficiency. © 2025 Elsevier Inc. All rights reserved
Cutting force and delamination optimization of nanoparticle-reinforced basalt/epoxy multi-scale composites in dry drilling by Taguchi design
No full textPurposeThe real-time performance requirements of montage components and assembly features of structural parts are among the most critical factors for the utilization of polymer-matrix laminates in the aerospace industry. In this context, the present study provides a comprehensive perspective on the dry drilling optimization of nanographene-added basalt fiber-reinforced epoxy composite laminates, focusing on cutting force and surface delamination damage.Design/methodology/approachThe combined effects of feed rate (FR) (0.10, 0.15 and 0.20 mm/rev), tool diameter (3 and 5 mm) and nanographene ratio (0, 0.3 and 0.7 wt.%) were investigated as input parameters using a specially designed dagger tool for the first time in the literature. Additionally, Taguchi's L18 design was employed to determine the optimal combination of input variables.FindingsThe results indicate that lower feed rates, smaller tool diameters and higher nanoparticle concentrations result in the lowest cutting forces. As for the delamination factor, lower feed rates, larger tool diameters and higher nanoparticle concentrations were identified as the best combination to maintain the structural integrity of the machined surfaces. Only localized minor chips were seen at the best combination. Detected outcomes can be used for future projects that aim to explore the joining strength of mechanical assembly for aircraft laminate structures.Originality/valueAchieving high-performance composite assemblies in aerospace applications (particularly in wing, fuselage and interior components), with sufficient mechanical properties, requires precise optimization of drilling operations to ensure strong joints and high-quality surfaces without delamination defects. This study, specifically focusing on nanoparticle-modified basalt fiber-reinforced laminates for aerospace implementations, is the first to elucidate the combined effects of FR, tool diameter and nanoparticle ratio on thrust force and delamination factor
Expectations of the older people from housing in the context of aging in place: the case of Afyonkarahisar City (Türkiye)
No full textMany countries around the world are witnessing a period of significant demographic changes. As a developing country, T & uuml;rkiye is also experiencing a rapid aging and urbanization process. Changes in T & uuml;rkiye's population structure have caused the country's population to face the phenomenon of aging. According to the United Nations (UN), the ratio of the population aged 65 and over to the total population worldwide has increased from 6% in 1990 to 9.8% in 2022. According to the Turkish Statistical Institute (TurkStat) data, while the older population rate in T & uuml;rkiye is 9.9% in 2022, the older population rate in Afyonkarahisar is 11.8%. This study aims to determine the expectations of individuals aged 65 and over regarding their housing in Afyonkarahisar city center from the perspective of aging in place. It is also one of the few studies that examine the relationship of individuals with the environment and space in the context of urban aging and aging in place. Various hypotheses were formed for the research. To test these hypotheses, a questionnaire was applied to 374 older adults in the sample area determined in the city. In the study, explanatory factor analysis and difference tests were used to examine the factors affecting the housing preferences of older adults. According to the factor analysis results, the dimensions determining the housing expectations of older adults include housing facilities, housing size, housing type, toilet and bathroom use
Influential Educators of the History of Turkish Education through the Evaluations of the Pre-service Teachers: A Profile Study
No full textThe study aimed to examine the leading educators of the History of Turkish Education and their influential characteristics through the evaluations of teachers and to reveal an educator profile on a historical basis. With reference to the qualitative research, a phenomenology design pursuing to understand human experience was used in the study. The study group was determined using criterion sampling related to purposive sampling, consisting of 36 pre-service teachers who took the History of Turkish Education course from the researcher and prepared the reports in accordance with the criteria in the fall semester of the 2022-2023 academic year. The pre-service teachers' reports, including information about the phenomenon that had aimed to be investigated, were used as the data collection tool. The data were analysed through the content analysis method. When the pre-service teachers' evaluations were examined, specific properties of influential educators were identified. They were their personality, educator qualifications, level of recognition, ideas beyond the time, scientific aspects, being well-known and guiding, religious qualifications, political aspects, farsightedness, and being progressive. These properties contributed to presenting an influential educator profile during the historical process
Evaluation of the efficacy of a double-layered and single-layered synthetic scaffold for the treatment of knee osteochondral defects - an experimental study
No full textBackground Osteochondral defect (OCD) regeneration is difficult due to the different properties and repair potentials of bone and cartilage tissues. This study aimed to compare cartilage tissue healing by applying in vitro produced double-layered and single-layered scaffolds to osteochondral defects. Methods Ninety male Wester Albino rats with an age of over twelve weeks and a weight of 300-350 g were included in study. Group A was the control group (isolated OCD), Group B received a cellular double-layered scaffold, Group C received a cell-free double-layered scaffold, Group D received a cellular single-layered scaffold, and Group E received a cell-free single-layered scaffold. Biodegradable double-layered and single-layered scaffolds were obtained using L-lactide-co-glycolide (PLGA) and hydroxyapatite (HA) in the bone layer, PLGA and polyethylene glycol methyl ether methacrylate (PEGMEMA) in the cartilage layer. The resulting tissues were stained with Hematoxylin-Eosin and Masson's Tricrom. Improvement was evaluated at week 4, week 8, and week 12 according to the Modified Mankin and O'Driscol scales. Results The positive impact of scaffold-based cellular applications on morphological field changes was demonstrated. Groups B and C exhibited higher morphological field scores compared to groups D and E. In both scoring systems, group E showed a significant long-term increase. Although the vitality of chondrocyte cells in the scaffolds was confirmed, their desired effects diminished over time. The lowest cell population scores were observed in groups B and D. Although chondrocyte cells demonstrated sustained viability in the double-layered scaffold during the early period, this effect was not observed in the mid and late periods. Conclusions The double-layered scaffold had a limited effect in enhancing osteochondral regeneration. The single-layered scaffold was more effective in enhancing regeneration in the late period. Given the favorable late period outcomes associated with the single-layered scaffold, we propose that further clinical and laboratory studies focus on its long-term results.Afyonkarahisar Health Sciences University Scientific Research Projects CoordinatorshipNot applicable
Synthesis of phenols containing quinazolin-4(3H)-one ring and ınvestigation of their antioxidant activities
No full textBu çalışmada azot içeren altı üyeli heterosiklik bileşiklerin önemli bir bölümünü temsil eden kinazolin-4(3H)-on sınıfına ait dört adet bileşik (1-4) sentezlenmiş ve yapıları NMR (1H ve 13C) ve HRMS spektroskopisi teknikleri kullanılarak karakterize edilmiştir. Uygulama olarak sentezlenen bileşiklerin antioksidan aktiviteleri Fe3+-Fe2+ İndirgeme Kapasitesi, Cu2+-Cu+ İndirgeme Kapasitesi, DPPH (1,1-Difenil 2-pikril hidrazil) Serbest Radikali Süpürme Aktivitesi ve ABTS (2,2-Azino-bis (3-etilbenzo-tiyazolin-6-sülfonik asit) Radikali Süpürme Aktivitesi yöntemleri kullanılarak incelenmiştir. Bileşiklerin antioksidan aktiviteleri standart antioksidanlar olan BHA, BHT, α-Tokoferol ve Trolox’a karşı değerlendirilmiştir. Çalışmadan elde edilen bulgular 2-Metill-3-(2,3,4-trihidroksibenzilidenamino)kinazolin-4(3H)-on (4) bileşiğinin Fe3+-Fe2+ İndirgeme ve Cu2+-Cu+ İndirgeme aktivitesinin sırasıyla 2.163 ve 1.663 absorbans değeriyle bütün standartlardan daha iyi olduğunu göstermiştir. Yine 4 bileşiği IC50: 12.64 µg/mL değeriyle -Tokoferol’den daha güçlü DPPH radikali giderme aktivitesine sahipken IC50: 10.40 µg/mL değeriyle -Tokoferol ile kıyaslanabilir ABTS giderme aktivitesine sahiptir.In this study, four compounds (1-4) belonging to the quinazolin-4(3H)-one class, which represents a significant part of nitrogen-containing six-membered heterocyclic compounds, were synthesized and their structures were characterized using NMR (1H and 13C) and HRMS spectroscopy techniques. As an application, the antioxidant activities of the synthesized compounds were examined using Fe3+-Fe2+ Reduction Capacity, Cu2+-Cu+ Reduction Capacity, DPPH (1,1-Diphenyl 2-picryl hydrazyl) Free Radical Scavenging Activity and ABTS (2,2-Azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) Radical Scavenging Activity methods. The antioxidant activities of the compounds were evaluated against the standard antioxidants BHA, BHT, α-Tocopherol and Trolox. It has been shown that the Fe3+-Fe2+ Reduction and Cu2+-Cu+ Reduction activities of 2-Methyl-3-(2,3,4-trihydroxybenzylideneamino)quinazolin-4(3H)-one (4) are better than all standards with absorbance values of 2.163 and 1.663, respectively. While it has a stronger DPPH radical scavenging activity than α-Tocopherol with the IC50: 10.40 µg/mL value, it has an ABTS scavenging activity comparable to α-Tocopherol with an IC50: 10.40 µg/mL value
Cumhuriyetin İlk Sabahı Kitabının Sosyal Bilgiler Dersi Öğretim Programında Yer Alan Değerler Açısından Değerlendirilmesi
No full textCumhuriyetin İlk Sabahı adlı kitap, Millî Mücadele yılları ve Cumhuriyetin kuruluş hikayesini bir şerbetçi çocuğun gözünden etkileyici bir şekilde ele almaktadır. Kitap, tarihsel derinlik sunmasının yanı sıra, öğrencilerin yaşlarına uygun bir bakış açısı barındırmasıyla değerler eğitimi açısından da önemli bir kaynak olarak öne çıkmaktadır. Bu araştırmanın amacı, Cumhuriyetin İlk Sabahı kitabını Sosyal Bilgiler Dersi Öğretim Programı’nda (2024) yer alan değerler çerçevesinde incelemektir. Araştırmada nitel araştırma yöntemlerinden doküman analizi kullanılmıştır. Şermin Yaşar ve İlber Ortaylı tarafından yazılan, 120 sayfa ve 6 bölümden oluşan, 2023 yılında Kronik Kitap tarafından yayınlanan Cumhuriyetin İlk Sabahı isimli kitap araştırmanın veri kaynağını oluşturmuştur. Araştırma verilerinin analizinde içerik analizi kullanılmış, elde edilen veriler kitap içeriğinden yapılan doğrudan alıntılarla desteklenerek sunulmuştur. Araştırma sonucunda; Cumhuriyet’in İlk Sabahı kitabında en çok vatanseverlik, çalışkanlık ve sorumluluk değerlerine yer verildiği, sevgi, yardımseverlik ve duyarlılık gibi değerlerin de ön plana çıktığı belirlenmiştir. Kitabın, Milli Mücadele dönemi ve Cumhuriyetin kuruluş sürecine uygun bir içerik sunarak çocuklara hem milli hem de evrensel değerler kazandırma açısından önemli bir katkı sağladığı tespit edilmiştir. Araştırmada elde edilen sonuçlara göre, sosyal bilgiler derslerinde değerler eğitimi kapsamında Cumhuriyet’in İlk Sabahı gibi edebi eserlerin kullanımının teşvik edilmesi, öğrencilerin değerleri özümseyebilmeleri için yaratıcı etkinliklerin planlanması ve öğretmenlere bu eserlerin etkili kullanımına yönelik atölye çalışmalarının düzenlenmesi önerilmiştir
Specialty in the Turkish private security sector
No full text21.Yüzyıl’da, mesleklerin gelişmesi ve bu alanlardaki bilgi birikiminin artmasıyla birlikte mikro uzmanlaşma eğilimi ortaya çıkmıştır. Bu tür uzmanlaşmanın sektörler açısından etkinlik, verimlilik ve ekonomik büyüme gibi birçok pozitif sonuçları bulunmaktadır. Türkiye'de ise, özel güvenlik sektörü önemli büyüklüğe erişmesine rağmen sektörel uzmanlık alanları hakkında bilgi bulunmamaktadır. Bu bağlamda araştırma, Türk özel güvenlik sektöründeki uzmanlık alanlarını tespit etmek üzere gerçekleştirilmiştir. Araştırma keşfedici bir tekli durum çalışmasıdır. Araştırma verisi, şirket kurucusu, şirket yöneticisi, kuruluş yetkilisi, güvenlik sorumlusu, uzman eğitici ve özel güvenlik görevlisinden oluşan 3.230 kişiden toplanmıştır. Veri içerik analizine tabi tutulmuş ve elde edilen 41 kodun yedi tema altında toplandığı tespit edilmiştir. Ayrıca araştırmanın geçerliliğini artırmak amacıyla, elde edilen sonuçlar ayrı bir katılımcı grupla paylaşılarak odak grup görüşmesi gerçekleştirilmiştir.In the 21st century, with the development of professions and the increase in knowledge in these areas, the trend towards micro-specialization has emerged. This kind of specialization has many positive results for sectors such as effectiveness, efficiency, and economic growth. In Türkiye, although the private security sector has reached significant growth, there is no information about sectoral specialties. In this context, the research was conducted to determine the specialties in the Turkish private security sector. The research was an exploratory single case study. The research data was collected from 3,230 people, including company founders, company managers, institution officials, security officials, expert trainers, and private security officers. The data was subjected to content analysis, and it was determined that 41 codes were collected under seven themes. In addition, in order to increase the validity of the research, the results were shared with a separate participant group, and a focus group interview was conducted