OpenMETU (Middle East Technical University)
Not a member yet
110280 research outputs found
Sort by
Işığa duyarlı azobenzen yan grubunun kumarinin optik ve kiroptik davranışı üzerindeki etkisi
No full textThe conformation/configuration of the side chain in coumarin derivatives
significantly impacts their features and applications, making them versatile in
various scientific and industrial fields. This versatility can be attributed to their
capacity to modify chemical reactivity, binding interactions, pharmacological
activity, stability, solubility, and material qualities. In this context, the objective of
this study was to investigate the effect of a change in the conformation/configuration
of the azobenzene-containing side chain of coumarin linked to 3 rd and 7th positions.
For this purpose, eight different compounds were synthesized. The fact that
azobenzene derivatives can be irradiated with a specific wavelength of light to
achieve photoisomerization from the trans to the cis form has allowed it to be used
as a convenient and controllable side chain. To investigate the optical and chiroptical
properties of the synthesized materials, we conducted a series of UV-Vis,
fluorescence, and circular dichroism studies in various solvents, complemented by
theoretical studies.Kumarin türevlerindeki yan zincirin konformasyonu/konfigürasyonu; özellikleri ve
uygulamaları üzerinde kapsamlı ve önemli bir etkiye sahiptir. Çeşitli bilimsel ve
endüstriyel alanlardaki çok yönlülükleri; kimyasal reaktiviteyi, bağlanma
etkileşimlerini, farmakolojik aktiviteyi, kararlılığı, çözünürlüğü ve malzeme
niteliklerini değiştirme kapasitelerine dayandırılabilir. Bu kapsamda, kumarinin 3
veya 7 numaralı pozisyonlarına bağlı azobenzen içeren yan zincirinin
konformasyon/konfigürasyon değişikliğinin etkisinin araştırılması amaçlanmıştır.
Bu doğrultuda sekiz adet yeni bileşik sentezlenmiştir. Azobenzen türevlerinin belirli
bir dalga boyundaki ışığa maruziyeti sonucu trans formundan cis formuna
fotoisomerizasyonun sağlanabilir oluşu, onu kullanışlı ve kontrol edilebilir bir yan
zincir olarak kullanmaya olanak sağlamıştır. Bu bağlamda sentezlenmiş olan
maddelerin UV-Vis, floresans ve dairesel dikroizm spektroskopisi çalışmaları
yapılarak optik ve kiroptik özellikleri incelenmiş ve bu incelemeler teorik
çalışmalarla da desteklenmiştir.M.S. - Master of Scienc
Physical Growth and Biological Maturity Status of Young Table Tennis Players
No full textAlthough table tennis is a popular sport played by millions of people regularly and competitively, and the studies devoted to table tennis are increasing, the extent of literature on the growth and maturity status of young table tennis players is not extensive. The present study aimed to assess the growth and maturity status of young medal-winning table tennis players and compare them with non-medal-winning players. A group of 117 competitive players, consisting of 57 males (12.87±1.35 years) and 60 females (12.99±1.24 years), underwent measurements of standing height, sitting height, and body mass. Body mass index (BMI) was calculated by dividing weight (in kilograms) by the square of height (in meters), and growth status was determined using a reference database. Somatic maturity status was estimated using age at peak height velocity (APHV) and maturity offset, calculated by the difference between APHV and chronological age. The results indicated that the mean height, body mass, and BMI percentiles of both genders were higher than the 37thpercentile when compared to normative references. There were no significant differences in terms of growth and maturity status between medal-winning and non-medal-winning players in both genders. The study suggests that coaches might consider closely monitoring the growth and maturity levels of their players and potentially consider adjusting training strategies based on the players' physical characteristics. These findings could contribute valuable insights into talent identification, physical development, and their potential influence on performance in youth table tennis
A GAME THEORY PERSPECTIVE ON STRATEGIC PROFIT DISTRIBUTION IN COMPLEX IT PROJECTS
No full textIn this article, we examine the process of evaluating an Information Technology (IT) project undertaken by three capital-linked companies. Herewith we address one of the main branches and drivers of our modern economies. This scenario highlights a common decision-making issue in the IT industry. To effectively showcase the application of the big boss fuzzy interval games method, we have introduced some simplifications. Our analysis focuses on evaluating the project's attractiveness and devising a fair distribution strategy for the expected profits among the three companies. While the case study is specific to the IT sector, the approach and findings are broadly applicable, providing valuable insights into similar evaluation and profit distribution challenges across various industries and organizational contexts
Advancing Black Sea Research and Innovation to Co-Develop Blue Growth within Resilient Ecosystems
Get PDFStrengthening science-based policy in the Black Sea ;
Vulnerable and unique, the Black Sea’s ecosystem services are under threat from multi-stressors such as pollution and overfishing because of climate and anthropogenic pressures. The overarching aim of the EU-funded BRIDGE-BS project is assessing the current state of the Black Sea ecosystems, their services, and resilience to the multi-stressors, and creating the necessary means to manage these ecosystems sustainably. For that, it will use an interdisciplinary approach based on three nodes: service dynamics, blue growth incubators, and empowered citizens. The project will use pilot study sites at the regional level, with findings contributing to work packages addressing the four pillars of the Black Sea SRIA. This way, BRIDGE-BS strives to achieve a healthy, resilient and productive Black Sea by 2030.Funded under Horizon 2020 Framework Programme, H2020-BG-2020-
Preface for the special issue on February 6, 2023, Kahramanmaraş-Türkiye earthquakes (Mw=7.8 and 7.5): reconnaissance missions and first observations
No full textWhat is in a bag? Doing and becoming subjectivity
No full textThis article explores the ways in which material objects relate to selfhood, by focusing on school bags – a personal item that is close to bodies, expressive but also used. We review scholar work on self with a specific focus that conceptualises self in relation to material objects. This review portrays the self as a unique, dynamic, experiencing subjectivity in terms of either self-awareness or as an agent of social order. Building on this framework we propose a new understanding of self as a doing and therefore becoming subjectivity in order to understand self-order – self towards itself and other selves. We build our argumentation through a field study consisting of exploration of online social media platforms, observation of students’ daily routines, and interviews with 23 high school students. We show that material objects like bags are companions of selfhood; necessary for the accomplishment of daily lives, so arguably enabling the self to live the life it desires, where this companionship extends to constructing self, establishing and maintaining life goals and relationships to other selves, thereby accomplishment of selfhood. It turns out, as we carry bags, bags carry out our very selves
Enhanced Pathogen Control Through Thymol and Carvacrol Nanoemulsions: A Microfluidization Approach
No full textNanoemulsions based on bioactive compounds have a lot of potential as antibacterial agents in the food sector due to high solubility and bioavailability. Current research was designed to investigate the impacts of NE containing thymol and carvacrol on foodborne pathogens. NE were developed by emulsifying thymol and/or carvacrol with Tween 80 using microfluidization technique. The NE were characterized to determine their droplet size distribution, zeta potential, and polydispersity index, stability, viscosity, and morphology of NE by transmission electron microscopy (TEM). The antimicrobial activity of the NE was assessed against specific foodborne pathogens (Salmonella Paratyphi A, Campylobacter jejuni, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis), using agar well diffusion, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. While thymol NE incorporating sunflower oil produced smaller droplet sizes, NE produced spherical droplets that were nanoscale. The NE demonstrated remarkable stability throughout a 60-day period of storage at 4 °C. Carvacrol NE demonstrated the most effective suppression against the pathogenic bacteria tested, with inhibition values greater than 30.00 mm against E. faecalis and C. jejuni. For P. aeruginosa, the MIC value of carvacrol NE was 12.5 mg/mL, while for S. Paratyphi A, E. faecalis, and C. jejuni, it was 50 mg/mL. Apart from C. jejuni and P. aeruginosa, bactericidal concentration was > 100 mg/mL for all bacteria. As a result, carvacrol NE was observed to be more effective as an antimicrobial agent for food preservation and has potential applications in various food products to improve shelf life and safety
A Case Study into Turkish EFL Pre-Service Teachers’ CALL-Mediated Professional Development for Global Citizenship Education Through Inclusive Webquest Task Design
No full textBeing inquiry-oriented and socio-constructivist, web-quests offer multiple experiential project-based learning opportunities for 21st century inquiry-oriented EFL pre-service teachers’ professional development via collaborative knowledge construction and peer scaffolding. As contemporary EFL teachers need to address culturally and linguistically diverse learner profiles, they need to raise their awareness of how to incorporate global citizenship elements into their future teaching contexts and align their curricula accordingly to foster inclusive classroom practices. The current eight-week exploratory case study focused on 19 EFL pre-service teachers’ insights into the impact of a Webquest project integration related to global citizenship education into K-12 curricula on students and the impact of their collaborative Webquest design experience on their professional development in an online elective course called World Englishes and Culture at the foreign language education department of a Turkish state university. The data were collected via online pre-service teacher reflections, and semi-structured interviews and were analysed via thematic analysis. Findings indicated pre-service teachers’ self-reported gains regarding pedagogical and digital competencies regarding the creation of online collaborative, differentiated tasks aligned with global citizenship for diverse learner profiles, as well as their favourable insights into the integration of Webquests into K-12 curricula as a catalyst to foster a global mindset
The Role of Temperamental Characteristics in Growth Rates of Theory of Mind: A Turkish Care Types Study
No full textBackground: Environmental factors and child characteristics play roles in the development of the theory of mind (ToM). Objective: This study investigates the impact of early rearing environment and child temperament on the development of the ToM by evaluating children under the care of social services at three different time points. Methods: This study included 112 children from institutions, 60 from care villages, 62 from group homes, and 51 from foster care. These children were tested at three time points with 8-month intervals. The age range of the children was 23–62 months at the first time point and 40–78 months at the third. Frustration and perceptual sensitivity as child temperamental characteristics were assessed with the Early Child Behavior Questionnaire and the Children’s Behavior Questionnaire, while ToM was evaluated with a ToM task battery. Hierarchical linear modeling was performed to test the growth rate of ToM. Results: A three-way interaction (Frustration × Care Type × Time) revealed that children’s ToM understandings significantly improved over time across most conditions for children with high frustration in both group homes and institutions as well as for children with low frustration in institutions. However, children with low frustration in group homes did not show significant improvement, emphasizing the potential protective role of frustration in institutional settings. Conclusions: This study demonstrates the importance of child characteristics and early rearing environment on the development of the ToM over time
Kompozit Yapılarda İki Yönde Bağlı Global/Lokal Yöntem ile İlerlemeli Katmanlar Arası Yorulma Hasarının Modellenmesi ve Analizi
No full textDelamination and debonding are crucial failure modes in composite helicopter rotor components, demanding an accurate estimation of their growth and extent. A rapid and robust approach for analysing progressive fatigue delamination is essential to assess the propagation of interlaminar flaws.
Existing literature primarily confines progressive failure investigations to coupon scale due to substantial computation times and convergence challenges. The commonly observed strategy to tackle these issues involves utilising the global-local method. While global-local methods are prevalent in progressive damage computations, they are typically limited to static analyses; and the literature lacks global-local methods designed explicitly for progressive fatigue damage modelling.
Consequently, this study introduces a novel procedure for conducting extensive fatigue delamination analyses with a two-way coupling global-local method. This method applies the displacement field derived from the global model to the local model. Subsequently, the global model is updated iteratively based on internal nodal reactions of cohesive elements extracted from the local model.
The study presents the analysis results of the Double Cantilever Beam (DCB) model employing this method. The method gives consistent results with regular analyses and experimental findings. In 3D models with finer local mesh, the current method has a significant computational advantage over regular analyses.
This verified methodology is then applied to an element-level aerospace structure. The method's computational advantage and accuracy are also compared with the regular method, which shows its computational advantage in aerospace finite element analysis applications.Kompozit helikopter rotor yapısallarında, bütünlüğün korunması için delaminasyon (katmanlar arası ayrılma) ve yapışma hasarının ilerlemesinden kaçınılmalıdır. Bu nedenle bu yapılardaki delaminasyona açık bölgelerde hızlı ve doğru bir şekilde katmanlar arası hasar modellemesi yapılmasına ihtiyaç duyulmaktadır.
Ancak uzun hesaplama süreleri ve yakınsama sorunlarıyla karşılaşılması nedeniyle literatürdeki çalışmalar numune ölçeğiyle sınırlıdır. Bu sorunların ortadan kaldırılması için global-lokal yöntemler tercih edilmektedir. Global-lokal yöntemler literatürde yaygın olsa da, bu yöntemin kullanımı statik analizler ile sınırlıdır. Sonuçta literatürde yorulma yükü altında ilerlemeli hasar analizleri konusunda boşluk olduğu görülmektedir.
Bu çalışmada, yeni bir yaklaşımla iki yönde bağlanmış global-lokal yöntemle delaminasyon yorulma analizleri gerçekleştirilmiştir. Bu yöntemde, alt modelleme kullanılarak global modelden elde edilen yer değiştirme dağılımı lokal model sınırlarına uygulanmakta, ve buna ek olarak global model, lokal modelden elde edilen yapışkan eleman iç düğüm reaksiyon kuvvetlerine bağlı olarak güncellenmektedir. İki model birbirine bağlı olduğu için yakınsama sağlanana kadar tekrarlı analiz yapılması gerekmektedir.
Mevcut yöntemin doğrulanması için deneylerle desteklenmiş Çift Dirsekli Kiriş modelleri oluşturulmuş ve bu yöntemle elde edilen sonuçlar alışılagelmiş analiz yöntemleriyle ve deney sonuçlarıyla karşılaştırılmıştır. Bu yöntem, alışılagelmiş analiiz yöntemiyle ve deney verileriyle uyumlu sonuçlar vermiştir. Üç boyutlu analizlerde, özellikle sık ağ örgülü lokal modellerde, hatırı sayılır hesaplama avantajı elde edildiği görülmüştür.
Daha sonra kupon boyutunda doğrulanmış bu yöntem, bir havacılık yapısına uygulanmıştır. Sonuçlar alışılagelmiş yöntem ile karşılaştırılmış, benzer şekilde isabetli sonuçlar elde edildiği ve hesaplama süresinden tasarruf edildiği gösterilmiş, ve mevcut yöntemin havacılık Sonlu Elemanlar Analiz uygulamaları için de avantajlı olduğu sonucuna varılmıştır.Ph.D. - Doctoral ProgramTUSA