CHARACTERIZATION OF COMMERCIALLY AVAILABLE ALKALI RESISTANT GLASS FIBER FOR CONCRETE REINFORCEMENT AND CHEMICAL DURABILITY COMPARISON WITH SrO-Mn2O3-Fe2O3-MgO-ZrO2-SiO2 (SMFMZS) SYSTEM GLASSES

According to the relevant literature, the utilization of different kind of glass fibers in concrete introduces positive effect on the mechanical behavior, especially toughness. There are many glassfibers available to reinforce concretes. Glass fiber composition is so important because it may change the properties such as strength, elastic modulus and alkali resistance. Its most important property to be used in concrete is the alkali resistance. Some glasses of SrO–MgO–ZrO2–SiO2 (SMZS) quaternary system, such as 26SrO, 20MgO, 14ZrO2, 40SiO2 (Zrn glass), have been found to be highly alkali resistant thanks to their high ZrO2 and MgO contents. Previous researches on these glasses with MnO and/or Fe2O3 partially replacing SrO have been made with the aim of improving the chemical resistance and decreasing the production cost.The main target of the present study, first of all, was to characterize commercially available alkali resistant glass fiber for concrete reinforcement and then to compare its alkali durability with those of the SrO-Mn2O3-Fe2O3-MgO-ZrO2-SiO2 (SMFMZS) system glasses. For such purposes, XRF, Tg-DTA, alkali resistance tests and SEM analysis conducted with EDX were employed. According tothe alkali endurance test results it was revealed that some of the SMFMZS system glass powders are 10 times resistant to alkali environments than the commercial glass fibers used in this study.Therefore, they can be considered as alternative filling materials on the evolution of chemically resistant concrete structures

Hydrophobic Modification of Glass Surface by Using Sol-Gel Synthesized Glass Powder as A Surface Roughness Promoter

In this study, it was aimed to form a hierarchical surface by using glass powders in the coating solution which was applied to glass surfaces for reducing the surface energy. Glass powders (GP) were synthesized by sol gel method at room temperature in the presence of ammonium hydroxide as an alkali catalyst and ethanol water mixture as solvent. Glass powders were used as additives in the chemical modification material to form rough surfaces for obtaining hydrophobic property on the borosilicate substrates. Two solutions were prepared by using different silane types and three different amounts of glass powders were added to each. Substrates were coated with the prepared coating suspension. The coated samples were heat treated for curing of silane matrix at 110°C for an hour and then washed. The morphology and the size of the particles were visualized by scanning electron microscopy. Water contact angle measurements were carried out to determine the contact angle values and consequent hydrophobic features. 3 different powder ratios were used. Water contact angle values increased by the increasing powder ratio. Water contact angle values were reached to 115° from 20°

Evaluation of silver content and antibacterial activities of silver loaded fiber/cotton blended textile fabrics

The aims of this work were to analyze the antibacterial activity and laundering durability of the silver loaded cellulosic fiber/cotton blended antibacterial textile fabrics, to quantify the silver content present in fabrics, and to examine the relationship between the antibacterial activity and silver content. For this aims knitting fabrics consisting of SeaCell® Active, which is the cellulosic fiber incorporated with seaweed and silver ions, and cotton fibers blended with five different ratios were produced. All fabric samples bleached and washed 60 times. The antibacterial efficiency was evaluated according to AATCC 100-1999 method after each ten laundry cycles. Silver content of the fabrics were determined by atomic absorption spectroscopy (AAS). Fiber and fabric surfaces were investigated using Scanning Electron Microscopy (SEM) and by X-Ray Photoelectron Spectroscopy (XPS) views. Antibacterial tests showed that good antibacterial activity can be achieved after several washings even with 3% of SeaCell ® Active fibers in blended fabrics. Significant correlation was found between silver content and bacterial reduction

KARBONDİOKSİT TUTUCU OLARAK KULLANILAN KARBON NANOTÜPLER İÇİN EN UYGUN MODİFİKASYON TÜRÜNÜN BELİRLENMESİ

İklim değişikliğinin en önemli sebeplerinden birisi olan karbondioksit (CO2) emisyonlarının birincil kaynağı, enerji üretiminde kullanılan fosil yakıtlardır. Yanma sonrası oluşan CO2 emisyonlarını azaltmak için, adsorpsiyon prosesinin ve bu proseste özellikle karbon bazlı adsorbanların kullanımının oldukça etkili olduğu kanıtlanmıştır. Bunlardan birisi olan karbon nanotüplerin, adsorpsiyon kapasitesini artırmak için farklı modifikasyonları kullanılmaktadır. Ancak, en uygun modifikasyon türüne karar verirken sadece adsorpsiyon kapasitesi yeterli olmamakta, pek çok teknik kriterin yanında maliyetler de gündeme gelmektedir. Bu nedenle bu çalışmada, çok duvarlı karbon nanotüplerin polietilenimin (PEI), tetraetilenpentamin (TEPA), 3-aminopropiltrieoksilan (APTS) ve pürin takviyeli PEI olmak üzere dört farklı modifikasyonu ele alınmış ve en uygun modifikasyon türünü belirlemek için de çok kriterli karar verme (MCDM) teknikleri kullanılmıştır. Ele alınan kriterler (ön işlem maliyeti, modifikasyon malzemesi maliyeti, enerji ihtiyacı, adsorpsiyon kapasitesi, toplam döngü, adsorpsiyon kapasitesinin düşmesi, desorpsiyon sıcaklığı ve desorpsiyon süresi) SMART (Simple Multi-Attribute Rating Technique) ve CRITIC (Criteria Importance Through Intercritera Correlation) yöntemleri ile ağırlıklandırılmıştır. Modifikasyon alternatifleri, her iki yöntemden elde edilen ağırlıklandırma sonuçlarıyla COPRAS (Complex Proportional Assessment) yöntemi kullanılarak karşılaştırılmıştır. Çalışma sonucunda, dört farklı karbon nanotüp modifikasyonu içinden en uygun seçeneğin pürin takviyeli PEI olduğu belirlenmiştir

The Effect of Pulsatile and Non-Pulsatile Extra Corporeal Perfusion on Cerebral Oxygen Saturation in Cardiopulmonary Bypass Patients (Flow Type On Cerebral Oxygenatıon)

Aim:The flow type generated by a heart-lung machine is important in cardiopulmonary bypass. The use of pulsatile flow versus non-pulsatile flow during cardiopulmonary bypass has been a controversy among clinicians. We compared the effect of non-pulsatile and pulsatile flow during cardiopulmonary bypass on cerebral oxygenation.Materials and Methods:We conducted a retrospective study of 50 adult patients who underwent coronary artery bypass graft surgery at our university hospital, with near infrared spectroscopy used to compare differences in cerebral oxygenation between the pulsatile and non-pulsatile flow type.Results:There was no difference between the effect of pulsatile and non-pulsatile flow on the saturation of hemoglobin (SpO2), nor on the partial pressure of oxygen (pO2) and carbon dioxide (pCO2). The near infrared spectroscopy results were not different between the two flow types.Conclusion:There was no effect of the flow type generated by a heart-lung machine (pulsatile or non-pulsatile) on cerebral oxygenation in adult patients

Which treatment should we choose for tubo-ovarian abscesses? Results of an 8-year clinical training in a tertiary center

Objectives: Tubo-ovarian abscess (TOA) is inflammation of the pelvic organs, mainly originating from the lower genital tract and intestinal tract. Treatment options include antibiotic therapy, surgical drainage, and radiologically guided (interventional) drainage. In our study, we aimed to evaluate the treatment method to be chosen and thus to manage patients with tuba ovarian abscesses (TOAs) most accurately. Material and methods: This is a retrospective cohort study, and patients who applied to a tertiary center diagnosed with tuba ovarian abscess (TOA) were included. TOA size (cm), pre-treatment C-reactive protein (CRP) value, pre-treatment white blood cell (WBC) value, previous operation type, postoperative complication, and antibiotics used were screened. Results: 305 patients were included in the study, and medical treatment was applied to 140 patients, organ-sparing surgical drainage to 50 patients, and surgical treatment to 115 patients. TOA dimensions measured at the time of diagnosis were significantly lower in patients for whom only medical treatment was sufficient. Pre-treatment CRP levels, WBC levels, and length of stay were significantly lower in patients for whom only medical treatment was sufficient. There was no significant difference between the pre-and post-procedure CRP difference, antibiotics, and hospitalization time. Conclusions: Preferring minimally invasive treatment in cases requiring invasive treatment reduces the frequency of complications. Treatment of tuba ovarian abscesses (TOA) with minimally invasive methods will be more beneficial in terms of patient morbidity

Spor Bilimleri Fakültesi öğrencilerinin egzersize yönelik davranış düzenleme durumları ile akademik öz yeterlik algıları arasındaki ilişki

Purpose: This study aims to determine the relationship between students' exercise-oriented behavior regulation and their academic self-efficacy perceptions. Method: In study, the screening model was used to determine the relationship between exercise-oriented behavior regulation and academic self-efficacy perception. The data were obtained by Behavioral Regulations in Exercise Scale-2 and Academic Competence Scale. The questionnaires were applied to 238 people in total. Independent Sample t-Test and One Way Analysis of Variance (LSD), basic and Canonical correlation analysis were used in the analysis of the data obtained in the study. Results: As a result of the analysis, it was noted that there is a relationship between social status and internal regulation and unmotivation. In addition, it was found that there is a positive significant relationship between cognitive practices and internal regulation, unmotivation. In this section, it was also found that there is a positive relationship between technical skills and unmotivation. On other hand, it has been observed that there is a relationship between academic self-efficacy and behavior regulation.Amaç: Bu araştırmada, spor bilimleri fakültesi öğrencilerinin egzersize yönelik davranış düzenleme durumlarıyla, akademik öz-yeterlik algıları arasındaki ilişkinin belirlenmesi amaçlanmaktadır. Yöntem: Bu araştırmada, egzersize yönelik davranış düzenleme durumu ile akademik özyeterlik algısı arasındaki ilişkinin tespiti noktasında tarama modeline başvurulmuştur. Veriler Egzersizde Davranışsal Düzenlemeler Ölçeği-2 ve Akademik Yeterlik Ölçeği ile elde edilmiştir. Çalışmaya toplamda 238 spor bilimleri fakültesi öğrencisi katılmıştır. Elde edilen verilere, bağımsız örneklem t-testi, tek tönlü varyans analizi (lsd), basit ve kanonik korelasyon analizleri uygulanmıştır. Bulgular: Yapılan çözümleme sonucunda, sosyal statü ile içsel düzenleme ile güdülenmeme ve bilişsel uygulamalar ile içsel düzenleme ve güdülenmeme arasında istatistiksel açıdan anlamlı bir ilişki olduğu görülmüştür. Ayrıca, teknik beceriler ile güdülenmeme arasında ilişkinin anlamlı olduğu tespit edilmiştir. Diğer taraftan akademik öz yeterlik düzeyi ile davranış düzenleme durumları arasında anlamlı bir ilişki olduğu belirlenmiştir

Environmental Performance of Electricity Generation Based on Resources: A Life Cycle Assessment Case Study in Turkey

The aim of this paper was to determine how to change the environmental performance of electricity generation depending on the resources and their shares, in order to support decision-makers. Additionally, this paper presents an application of life cycle assessment (LCA) methodology to determine the environmental burdens of electricity generation in Turkey. Electricity generation data in Turkey for the years 2012 and 2023 were used as a case study. The functional unit for electricity generation was 1 kWh. The LCA calculations were carried out using CML-IA (v3.00) data and the results were interpreted with respect to Monte Carlo simulation analysis (with the Monte Carlo function built in SimaPro 8.0.1 software). The results demonstrated that the fossil fuel consumption not only contributes to global warming, but it also has effects on the elemental basis of abiotic depletion due to raw material consumption for plant infrastructure. Additionally, it was observed that the increasing proportion of wind power in the electricity mix would also increase certain life cycle impacts (such as the elemental basis of abiotic depletion, human ecotoxicity, and terrestrial ecotoxicity) in Turkey’s geography compared to increasing the share of other renewable energy sources, such as hydropower, geothermal, as well as solar