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Wood flour/-poly(methyl methacrylate)/capric acid polymer composites as form-stable phase change materials for thermal energy management
No full textThis study focuses on the preparation and characterization of wood flour (WF)/polymethyl methacrylate (PMMA)/capric acid (CA) composite form-stable phase change materials (PCM) prepared by PMMA modification method, with WF selected as the support material. The surface morphology (scanning electron microscopy SEM), chemical structure (Fourier transform infrared spectrometer, FTIR), crystalline structure (X-ray diffraction, XRD), phase change properties (differential scanning calorimeter, DSC), thermal stability (thermogravimetric analysis, TGA) of the prepared WF/PMMA/CA composite form-stable PCMs were investigated. SEM analysis demonstrates that the wood surfaces were coated with CA and PMMA. As the PMMA ratio on the surfaces increased, the amount of leaching decreased. FTIR and XRD results suggested that the structure of the PMMA polymer is also seen in the prepared composite materials. There was no chemical reaction but only physical interactions between WF and CA. The generated WF/PMMA/CA composite PCMs exhibited high latent heats and an appropriate phase change temperature range; in particular, the WF/PMMA/CA (1/1/2)'s highest latent heats throughout the melting and freezing processes were 95.08 J/g and 91.29 J/g, respectively. Using higher proportions of CA provides more energy storage capacity; however, the contribution of PMMA further enhances this effect, strengthening the energy storage performance. Thermal conductivity increased by 63.9 % in WF/PMMA/ CA (1/1/2)
Assessment of climate change impacts and land cover dynamics in the Upper Sakarya Basin, Türkiye using the Collect Earth approach
No full textLong-term monitoring and evaluation of climate change effects in a basin help identify trends, assess ecosystem resilience, and guide adaptive management for sustainable resource use and conservation. The Upper Sakarya Basin (USB), which has the ability to represent semiarid areas of Turkey due to its climate and environmental conditions and land use integrity, was selected as the study area. The study focused on Land Cover and Land Use Transformations, soil moisture, evapotranspiration, Normalized Difference Vegetation Cover (NDVI), Net Primary Production (NPP), water deficit criteria in the basin for a 20-year period (2000-2020) in order to support adaptive management and conservation strategies and to evaluate the effects of climate change on ecosystem dynamics, water balance and vegetation health. As a field monitoring and evaluation method, Collect Earth (CE), which is a sample-based visual interpretation method, was selected because it can better explain the complex structure of land cover types and provides the opportunity to easily access and interpret many graphical data through the GEE code editor. In the context of Land Use, Land-use Change and Forestry (LULUCF), it was observed that the increase in Forestland was due to afforestation activities in Grassland. Although this situation was observed in NDVI observations, it was not evaluated as a net gain area compared to the past situation of Forestland in terms of the ecosystem and the services they provide. It was determined that the conversion to Settlement in the basin was rapid and large in area. As an indicator of vegetation productivity, it was determined that the areas with decreasing trend in NPP were Forestland and Settlement. According to water deficit data, it was determined that water deficit was high in regions where intensive agriculture was carried out in the basin. Evapotranspiration value was continuously increasing for the basin in general, while soil moisture was on a decreasing trend. These findings emphasize the vulnerability of the basin to climate change and emphasize the need for sustainable land and water management strategies. It is recommended that decision makers at the basin scale develop policies based on these findings and evaluate interventions within the framework of a balancing approach against land degradation.Ondokuz Mayimath;s UniversityNot applicable
Investigation of the effect of group cohesion, group atmosphere, transactive memory system, and social interaction space on online cooperative learning attitude
No full textComputer-supported collaborative learning (CSCL) has become increasingly widespread in higher education with the spread of online and hybrid learning applications after the pandemic. Although CSCL is an increasingly used method in education, there are some problems experienced while using this method. One of them is related to the negative attitudes of students toward CSCL. This negative attitude can reduce the effectiveness of CSCL on the learning process and results. This study investigated the effect of group collaboration processes on students' attitudes toward CSCL. The research was carried out on students studying at the education faculty of a state university and taking the information technologies II course with the CSCL method. During an academic term, students carried out their course applications as collaborative learning groups that they formed in line with their wishes using the CSCL method. The research was carried out on 209 students. Path analysis was carried out in the research. As a result of the research, it was seen that group atmosphere, transactive memory system, and social interaction space positively affected the positive attitude towards CSCL. In addition, it is seen that the negative attitude towards social interaction space CSCL has the opposite effect. According to the research findings, it can be said that taking measures to improve the group atmosphere, transactive memory system, and social interaction space in CSCL can positively affect the attitude. In line with the findings obtained from the research, various suggestions were made for researchers and educators for the effective use of CSCL environments
Bartınlı Kadınların Mantosu: Geleneksel Gaba Yazma
No full textÖz: Bartın geleneksel yazmaları, özellikle “gaba yazma" olarak bilinen siyah zemin üzerine büyük çiçekli yazmalarıyla Anadolu baskı yazmacılığında önemli bir yere sahiptir. “Bartınlı kadınların mantosu” olarak ifade edilen “gaba yazma” ilin kültürel kimliğini, kadınların sosyal yaşamını yansıtması bakımından korunması ve gelecek nesillere aktarılması gereken önemli bir kültürel mirastır.Bu çalışma, unutulmaya yüz tutmuş Bartın ağaç baskı sanatı ve ilin yöresel kimliğinin simgesi olan "gaba yazma”nın kültürel bağlamı hakkında bilgiler içermektedir.Bununla birlikte yörenin geçmişte önemli bir el sanatı olan ağaç baskı sanatı ile Bartın yöresine özgü olan geleneksel “gaba yazma”nın geçmişi, günümüzdeki durumu ve geleceği üzerine değerlendirmeler yapılmıştır. Bu çalışma söz konusu kültürel değerlerin korunması ve gelecek nesillere aktarılması için bir çağrı niteliği taşımaktadır. Yörenin önemli kültürel değerlerinden olan Bartın yazması ve geleneksel baskı sanatının Halkbilimi literatürüne kazandırılmasının hedeflendiği bu çalışma; hem yörenin önemli bir kültürel mirasının korunmasına hem de bu alanda yapılan az sayıdaki çalışmaya akademik katkı sağlayacaktır. Makale, literatür taraması ve derlemeler neticesinde oluşturulmuştur. Günümüzde yörede unutulmaya yüz tutmuş el sanatını icra eden bir usta olmadığı için geleneksel ağaç baskı hakkında bilgisi olan en yetkin üç kişiyle derleme yapılmıştır.Bu görüşmelerde geleneksel sanatın teknikleri, kullanılan malzemeler, desenlerin anlamları, ağaç baskı sanatının günümüzdeki durumu ve “gaba yazma”nın kültürel anlamı hakkında bilgi toplanmıştır. Bartın'ın unutulmaya yüz tutmuş iki önemli kültürel değerinin son durumları kayıt altına alınmış olup araştırma sonucunda gelecek nesillere aktarılması yönünde neler yapılabileceği konusunda öneriler içermektedir. Anahtar Kelimeler: Geleneksel El Sanatı, Ağaç Baskı Sanatı, Bartın, Geleneksel “Gaba Yazma”, Motif ve Desen.Öz: Bartın geleneksel yazmaları, özellikle “gaba yazma" olarak bilinen siyah zemin üzerine büyük çiçekli yazmalarıyla Anadolu baskı yazmacılığında önemli bir yere sahiptir. “Bartınlı kadınların mantosu” olarak ifade edilen “gaba yazma” ilin kültürel kimliğini, kadınların sosyal yaşamını yansıtması bakımından korunması ve gelecek nesillere aktarılması gereken önemli bir kültürel mirastır.Bu çalışma, unutulmaya yüz tutmuş Bartın ağaç baskı sanatı ve ilin yöresel kimliğinin simgesi olan "gaba yazma”nın kültürel bağlamı hakkında bilgiler içermektedir.Bununla birlikte yörenin geçmişte önemli bir el sanatı olan ağaç baskı sanatı ile Bartın yöresine özgü olan geleneksel “gaba yazma”nın geçmişi, günümüzdeki durumu ve geleceği üzerine değerlendirmeler yapılmıştır. Bu çalışma söz konusu kültürel değerlerin korunması ve gelecek nesillere aktarılması için bir çağrı niteliği taşımaktadır. Yörenin önemli kültürel değerlerinden olan Bartın yazması ve geleneksel baskı sanatının Halkbilimi literatürüne kazandırılmasının hedeflendiği bu çalışma; hem yörenin önemli bir kültürel mirasının korunmasına hem de bu alanda yapılan az sayıdaki çalışmaya akademik katkı sağlayacaktır. Makale, literatür taraması ve derlemeler neticesinde oluşturulmuştur. Günümüzde yörede unutulmaya yüz tutmuş el sanatını icra eden bir usta olmadığı için geleneksel ağaç baskı hakkında bilgisi olan en yetkin üç kişiyle derleme yapılmıştır.Bu görüşmelerde geleneksel sanatın teknikleri, kullanılan malzemeler, desenlerin anlamları, ağaç baskı sanatının günümüzdeki durumu ve “gaba yazma”nın kültürel anlamı hakkında bilgi toplanmıştır. Bartın'ın unutulmaya yüz tutmuş iki önemli kültürel değerinin son durumları kayıt altına alınmış olup araştırma sonucunda gelecek nesillere aktarılması yönünde neler yapılabileceği konusunda öneriler içermektedir. Anahtar Kelimeler: Geleneksel El Sanatı, Ağaç Baskı Sanatı, Bartın, Geleneksel “Gaba Yazma”, Motif ve Desen
Obtusifolin improves cisplatin-induced hepatonephrotoxicity via the Nrf2/HO-1 signaling pathway
No full textCisplatin (CIS) is a highly effective chemotherapeutic drug, but one of its most serious side effects is hepatonephrotoxicity, which varies based on its dosage and duration of use. Previous studies have reported that obtusifolin (OBS) exhibits several pharmacological effects, including antioxidant and antidiabetic activities. In this study, we investigated the protective effects of OBS against CIS-induced hepatonephrotoxicity. OBS (0.5 and 1 mg/kg, i.p.) was administered to male mice for 10 days, while CIS (20 mg/kg, i.p.) was administered on day 7 to induce hepatonephrotoxicity. The results showed that OBS reduced the CIS-induced elevations in AST, ALT, ALP, BUN, and creatinine levels by approximately 14%, 11%, 9%, 18%, and 14%, respectively. OBS also decreased liver and kidney MDA levels by approximately 31% and 25%, while enhancing liver and kidney GSH, SOD, and CAT levels by 50-36%, 80-70%, and 95-55%, respectively. In association with oxidative stress and the apoptotic process, OBS reduced liver and kidney mRNA expression levels of Nrf2 (by approximately 1.7- and 1.6-fold, respectively), HO-1 (by 1.6- and 1.4-fold, respectively), and Bcl-2 (by 1.6- and 1.4-fold, respectively). Additionally, OBS suppressed the mRNA expression levels of NF-kappa B (by 0.7- and 0.7-fold), TNF-alpha (by 0.6- and 0.6-fold), Bax (by 0.8- and 0.7-fold), and Cas-3 (by 0.7- and 0.7-fold). Protein expression analysis revealed that OBS increased Nrf2 (showing a 1.7- to 1.2-fold) and Bcl-2 levels (by 1.3- to 1.8-fold), and reduced Bax (by 0.7- to 0.8-fold) and caspase-3 (by 0.7- and 0.7-fold) levels altered by CIS treatment. Histopathological examinations confirmed that OBS reduced liver and kidney damage caused by CIS. In conclusion, OBS significantly improved CIS-induced hepatonephrotoxicity by reducing oxidative stress, inflammation, and apoptosis via modulation of the Nrf2/HO-1 pathway. These findings suggest that OBS could be a potential therapeutic agent for mitigating the side effects of chemotherapeutics.Scientific and Techno-logical Research Council of Turkiye (TUBIdot;TAK)Open access funding provided by the Scientific and Techno-logical Research Council of Turkiye (TUB & Idot;TAK)
Investigation of Psychometric Properties of the Turkish Version of the Motivation to Lead Scale on Teachers
No full textLeadership in schools is undergoing a transformation involving all school personnel, especially for teachers. Teachers constitute the basic human resource of both school principals and teacher leadership with their formal and informal leadership roles. However, understanding the emergence of a teacher as a leader and interpreting the motivational processes behind leadership tendencies continues to be an equation with many unknowns in the leadership literature. To identify teachers who are motivated to lead in the field of school leadership; help develop a pool of potential leaders for schools; In order to increase leader effectiveness and organizational performance, it is important to investigate the factors that motivate talented teachers to take leadership roles. For these reasons, in the present study, the psychometric properties of Chan and Drasgow's (2001) "Leadership Motivation Scale" (LEMS), which combines various factors in leadership, on teachers were examined. The study was carried out with teachers working in different school types in Ankara. The psychometric properties of MTLS were primarily examined in terms of content validity and language equivalence. Evidence for the construct validity of the scale was provided by EFA (n: 304), and CFA (n: 500). Research results are “social-normative MTL”; “affective-identity MTL” and, “non-calculative MTL” supported the three-factor structure of MTL. In addition, testing the psychometric properties of MTLS on the teacher group is a first step in the related literature. In this context, it is expected that the research will provide a different perspective to both comparative research in the MTL literature and new research on school leadership. Keywords: Motivation to lead; validity and reliability; individual differences; leadershi
Emerging Synbiotics Consisting of Catechin and Probiotic Bacteria: Exploring Aggregation, Adhesion, Antioxidant, and Anticancer Effects
No full textProbiotic bacteria are microorganisms that confer health benefits on the host, when administered in adequate amounts. Catechin, naturally found in nature and human diet, has strong antioxidant, antibacterial, and anticancer potentials. Phenolic compounds and probiotic bacteria are found together in gastrointestinal tract (GIT), and their potential synbiotic interactions are not fully understood. The present study aims to investigate the probiotic properties effects of catechin on (bacterial growth, auto-aggregation, co-aggregation) on well-known probiotic bacteria Lactobacillus acidophilus LA-5 (LA-5) and Lacticaseibacillus rhamnosus GG (LGG), and in vitro cytotoxic effects of the synbiotic combination of catechin and probiotic bacteria on colon cancer cells Caco-2. Results show that catechin contributed to bacterial growth of LA-5, auto-aggregation of LA-5, co-aggregation of LA-5 with Staphylococcus aureus. Catechin increased the adhesion potential of LA-5 and LGG by 6% and 5%, respectively. In DPPH scavenging activity, LGG grown with catechin exerted 30% more antioxidant potential compared the LGG. Moreover, LA-5 grown in the presence of catechin led to higher cell death of Caco-2 when compared to control while it did not influence the genotoxicity property of LA-5. However, catechin did not promote the cytotoxicity and genotoxicity properties of LGG. In conclusion, catechin enhanced many physiological properties of probiotic bacteria and thus, synbiotic relationship of catechin and probiotics may offer novel insights into the prevention/treatment of colon cancer.Bartin UniversityThe authors acknowledge Chr. Hansen, Turkiye for the probiotic strains
PtCo/g-C3N4 bimetallic catalyst: Boosting hydrogen production in sodium borohydride hydrolysis
No full textDeveloping inexpensive and low-cost heterogeneous catalysts for hydrogen (H-2) release from chemical hydrogen storage materials such as sodium borohydride (NaBH4) is crucial for renewable, sustainable, and clean energy. For this purpose, we prepared an efficient bimetallic Pt0.77Co0.23/g-C3N4 catalyst for hydrogen production from the hydrolysis of NaBH4 and characterized it with advanced spectroscopic techniques, including inductively coupled plasma optical emission spectrometer (ICP-OES), powder X-ray diffraction (P-XRD), scanning electron microscope (SEM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), and X-ray photoelectron spectroscopy (XPS). The H-2 released during the hydrolysis of NaBH4 was monitored through water displacement in a burette. The Pt0.77Co0.23/g-C3N4 catalyst exhibited a remarkable hydrogen generation rate (HGR) of 1373.1 mL min(-1) g(-1) at 298 K during NaBH4 hydrolysis. Additionally, the activation parameters were found to be 35.7 kJ/mol (Ea(#)), 38.9 kJ/mol (Delta H-#), and -119.6 J/molK (Delta S-#). Finally, the catalyst's recyclability performance was observed to retain >87.13 % of its catalytic conversion and >60.87 % of the catalytic activity even after the third recycling cycle
Bartın İlinde İçme/Kullanma Suları Üzerine Ön Çalışma
No full textİçme suları şebeke hatlarındaki problemler, su kalitesini etkileyebilir. Bu nedenle, arıtma tesisi çıkışında elde edilen uygun kalitedeki su, uç noktada kabul edilemeyecek düzeye ulaşabilir. Su kaynaklı mikrobiyal kirlenmenin önüne geçebilmek adına dezenfeksiyon yöntemleri uygulanmaktadır. Klor ile dezenfeksiyon, mikrobiyal kirlenmeyi önlerken su içerisinde bulunan kirleticilerle etkileşime girerek çeşitli problemlere sebep olabilir. Bartın ili hizmet alanı içerisinde yer alan 20 farklı mahalleden, tesadüfi olarak seçilmiş ev, cami, gıda işletmeleri ve sanayi işletmelerinden Mart ve Haziran ayları içerisinde aynı gün su numuneleri alınarak, bulanıklık, renk, toplam çözünmüş katı, serbest ve toplam klor analizleri yapılmıştır. Bulanıklık değeri, 17 noktada TS 266 ve İnsani Tüketim Amaçlı Sular Hakkında Yönetmelik sınır değeri olan 1 NTU değerinden yüksek bulunmuştur. Renk parametreleri incelendiğinde en yüksek renk, 17 PtCo değeri ile Cumhuriyet Mahallesi'nde bulunmuştur. 8 mahallede serbest klor miktarı mevzuat sınır değeri olan 0,2 mg/L değerinden düşüktür. Ayrıca, 4 mahallede serbest klor miktarları 2,8 - 3,48 mg/L aralığında tespit edilmiştir. Sonuçlar incelendiğinde, aynı su dağıtım şebekesinde bulunan farklı noktalardaki ölçüm parametreleri arasında belirgin farklılıklar göze çarpmaktadır. Bunun nedeninin şebeke hatlarındaki bozukluklar olduğu düşünülmektedir. Şebeke hatlarının onarımı ve yenilenmesi yerine klorlama miktarının artırılarak halk sağlığının korunmasının amaçlanması, ancak geçici bir çözüm olacaktır
Türkiye'nin Gözünden Türk-Sovyet İlişkilerinin Gelişiminde Sporun Rolü (1924-1936)
No full textWith its appeal beyond borders, sports have become an important tool used by the governments of various countries to be more effective in international politics. The aim of this study is to reveal how sports is applied in international relations within the framework of Turkish-Soviet relations. The Soviet Union (USSR) was one of the countries with which Türkiye had the most contact in sports during the interwar period. As a result of the regime change, both countries aimed to prove their existence and power to the world. They used sports as a tool, which is one of the important ways to show this. The governments of both countries played an active role in ensuring these sports encounters which contributed to the development of friendly relations between the people of the two countries. © 2025 Elsevier B.V., All rights reserved