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Investigation of thermal energy storage capacities of phase change material embedded different bio-based materials converted into biochar
No full textIn recent years, latent heat thermal energy storage systems have emerged as a significant technique for addressing the variable nature of renewable energy sources, balancing energy demand, and enhancing energy efficiency. Additionally, phase change materials (PCMs) with high latent energy storage capabilities have become increasingly popular as the preferred materials for thermal energy storage applications. This study investigates the effects of using composite materials with phase change materials embedded in biochar pores through microencapsulation on improvements in latent energy storage capacity. To achieve this, various organic materials, including hazelnut shells, peanut shell, pine cone, and poplar sawdust, were converted into composite biochar through pyrolysis, thereby enhancing their porosity. The results obtained are given in comparison with the results of composite materials with phase change materials encapsulated in the pores of the raw material. The latent heats of the composites impregnated with phase change material (PCM) in their pores were compared to identify the most suitable composite biochar material. The best performance improvements in energy storage capacities compared to the raw material results were found to be 134.8% and 147.6% for RT-28/Peanut shell biochar and RT-28/Pine cone biochar composites, respectively. On the other hand, the highest energy storage capacity for both raw material and biochar was measured as 50.18 J g-1 and 75.1 J/g for poplar sawdust, respectively. The results indicated that poplar sawdust was the most appropriate base material
Optimal Design and Analysis of the Cooled Turbine Blade in Gas Turbines with CFD
No full textIn this study, the effects of the structural geometries of the channels used for cooling blades in the heated regions of the gas turbine exposed to high temperature were investigated. It is aimed to cool the gas turbine blade using 10 different types of ribbed channels by simulation method. Roof, inverted roof, slope and wedge ribs with standard and stepped arrangements developed for improving thermal performance in a rectangular cooling duct with a 4:1 ratio aspect were studied. Square type rib, the basic geometry is designed to make thermal comparisons. Details of turbulent flow and numerical calculations were made using of the standard k-epsilon turbulence model by means of the Computational Fluid Dynamics (CFD) method. The heat transfer in ribbed walls was examined in four different Reynolds numbers, 10000, 20000, 40000 and 80000 according to the channel input cross section. As a result of the calculations, the temperature changes of the turbine blade depending on Re number, the heat transfer improvement occurring in the internal channels inside the blade and the overall thermal performance were compared. The different types of rib evaluated in the study were compared with the standard-square rib; higher Nu number was obtained in stepped-wedge rib, stepped-roof rib, stepped-slope rib and stepped- inverted roof rib, respectively. It has been observed that a stepped-wedge rib can improve overall thermal performance and is promising for internal turbine blade cooling applications. The best operating range of all models was found to be between Re=40000 and Re=80000. The highest PEC results were obtained in the stepped-wedge rib model. This is 3.37% higher than the closest performing stepped-inverted roof rib model with 5.04 at Re=8000
Prognostic Biomarkers in Isocitrate Dehydrogenase Wild-Type Glioblastoma: A Focus on B7-H3
No full textBackground: Isocitrate dehydrogenase (IDH) wild-type (wt) glioblastoma is an aggressive malignancy associated with poor clinical outcomes, marked by high heterogeneity and resistance to treatment. This study aims to investigate the prognostic significance of B7-H3 expression in IDH wt glioblastoma and its potential association with clinical outcomes, including overall survival (OS) and progression-free survival (PFS). Additionally, the relationship between B7-H3 and PD-L1 expression was explored. Methods: A retrospective cohort of 86 IDH wt glioblastoma patients, all of whom underwent surgery, radiotherapy, and temozolomide treatment, was analyzed. B7-H3 expression was quantified using an immunoreactivity score (IRS), classifying samples as low (IRS 4). PD-L1 expression was evaluated based on tumor and immune cell staining, with >5% positivity indicating significant expression. Results: High B7-H3 expression was significantly associated with poorer OS and PFS. Co-expression of B7-H3 and PD-L1 was prevalent, particularly among younger male patients with unifocal tumors; however, PD-L1 expression did not show a significant correlation with clinical outcomes. Conclusions: B7-H3 appears to be a promising prognostic biomarker in IDH wt glioblastoma and may serve as a target for developing combination therapies, integrating B7-H3-targeting treatments with immune checkpoint inhibitors. Further prospective studies are necessary to validate these findings and to explore potential therapeutic strategies
Selection of a Facility Location for a Cosmetics Company by Integrated F-LBWA and I-RAWEC Methods
No full textThe first step of a company's achievement in upcoming periods starts with the decision of correct investment location. It is also essential to consider scientific approaches in this context. Within the scope of this fundamental principle, this study aimed to determine the most feasible investment location among 47 African countries for a leading cosmetics company operating in T & uuml;rkiye. The indicators outlined in the World Bank's Doing Business reports are used for the first time in this research within the context of investment location selection studies that employ quantitative decision-making methods. The weighting of 10 main criteria and 44 sub-criteria in the report is performed by Fuzzy Level Based Weight Assessment (F-LBWA) method. The priority ordering of 47 African countries is determined using the Improved-Ranking Alternatives with Weights of Criterion (I-RAWEC) method, which is derived by implementing an improvement to the normalization stage of Ranking Alternatives with Weights of Criterion (RAWEC) approach. Moreover, in order to confirm the validity of the proposed method, a sensitivity analysis is conducted, which examines the impact of a gradual change in criterion weights on the order of the alternatives. The findings of this study present a novel approach to assessing potential investment opportunities in Africa for the cosmetics industry and offer a significant starting point for future investment decisions and research endeavors
Metaverse Perception Scale Development and Validation
No full textThe metaverse, perceived as the next phase of the Internet, promises to transcend mere upgrades by integrating transformative technologies such as artificial intelligence, virtual reality, and blockchain, which form the foundations of its structure. However, the absence of a standardized scale to assess perceptions of the metaverse poses a considerable limitation to studies in social science on this topic. This study developed a measurement tool that can be used in social science investigations to address this gap. Working with experts in the field, we created a pool of items encompassing six dimensions and 67 items. Exploratory factor analysis examined the data collected from 209 participants, and the confirmatory factor analysis assessed data from 247 participants. The proposed scale comprises 25 statements and six dimensions: (i) anxiety, (ii) education, (iii) entertainment, (iv) psychosocial effect, (v) knowledge-sharing, and (vi) business
Experimental and theoretical insights to enhanced inhibition of copper corrosion in a typical pickling environment by polyethylene oxide-b-polypropylene oxide copolymer-based hybrid inhibitor
No full textCopper holds significant industrial and commercial significance due to its favourable characteristics finding extensive application in the manufacturing of electronic components, interconnects, wires, pipelines, water supply systems, and heat exchangers. Nevertheless, Cu materials are vulnerable to corrosion, especially in hostile environments containing chloride ions. Although Cu deterioration can be managed through the use of corrosion inhibitors, finding compounds that are non-toxic, available, and effective against copper corrosion is a difficult task which is the reason research on the identification of corrosion inhibitors is still ongoing. In this work, polyethylene oxide-block-polypropylene oxide (PEO-b-PPO) copolymer is explored as an inhibitor for Cu in a 5 wt% HCl solution. Gravimetric and electrochemical techniques in conjunction with surface analysis methods are employed. Computational calculations using the generalized gradient approximation with the Double Numerical Plus Polarization basis set have been performed. The effect of KI addition on the performance of PEO-bPPO is also investigated. The results disclose that the PEO-b-PPO/KI hybrid is an excellent inhibitor. An inhibition efficiency of 90.84% is achievable with 15 mu M PEO-b-PPO/3 mM KI after 48 h of immersion at 50 degrees C. The calculated synergism parameter is 2.49 and indicates a strong synergism. The surface analysis results validate the deposition of a densely PEO-b-PPO/ KI protective layer on the Cu surface. The computational calculations reveal that the PEO-b-PPO copolymer interacts strongly with the Cu surface to form a protective layer. The interaction energy for PEO-b-PPO/Cu(111) is -1.12 eV and indicates enabling electronic properties of the polymer for improved interaction with copper atoms.Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, University of Nottingham Ningbo China, Ningbo, China [I01240100007]; UNNC New Researchers Grant [NRG2023100001]This work was supported by the Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, University of Nottingham Ningbo China, Ningbo, China [Grant No. I01240100007] , and the UNNC New Researchers Grant [Grant No. NRG2023100001]
Impact of Ohmic Heating and Ultrasound Pretreatments on Oil Absorption and Other Quality Parameters of Fried Potato [2]
No full textIn this study, the effect of pretreatments ((hot water blanching (HWB), ultrasound (US) and ohmic heating (OH)) on reducing the oil absorption of potato during frying and the changes in the quality parameters of the product ((total polyphenol (TP), in vitro digestion, total flavonoid (TF), antioxidant capacity (AC), chlorogenic acid (CA), textural and sensorial properties)) were investigated. The pretreatments applied significantly affected oil absorption and quality parameters of fried potato. The oil content of fried potatoes ranged from 26.06 to 32.01% depending on the pretreatment. OH-pretreated potato had the highest content of TP (41.27 mg GAE/100 g dry matter-DM), TF (32.89 mg RE/100 g DM) and CA (1.72 mg/100 g DM). However, there was no significant difference between the pretreatments in terms of bioaccessibility of polyphenols at the end of digestion. Also, AC value of fried potato pretreated by OH (124.13 mmol AAE/100 g DM) was higher compared to that of fresh potato (83.91 mmol AAE/100 g DM), but other two pretreatments caused a decrease in AC. The highest hardness was observed in HWB-treated potato strips. OH-treated potato had the best color parameters. Sensory data indicated that US-pretreated potato had the highest sensory scores followed by OH- and HWB-pretreated ones, respectively. Consequently, based on the above comprehensive quality evaluation, it can be suggested that OH pretreatment is a better choice for preparing deep fried potato. © The Author(s) 2024.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAKBursa Uludağ Üniversitesi, BUÜ, (FKO-2020–169)Bursa Uludağ Üniversitesi, BU
Evaluation of the clinical characteristics, laboratory parameters, and antibiotic treatment in patients diagnosed with tularemia
No full textIntroduction: This retrospective, cross-sectional, multi-center study aimed to evaluate the impact of laboratory results and treatments on the treatment response in patients diagnosed with tularemia. Methods: The study included 190 adult patients diagnosed with tularemia between November 2023 and June 2024. Results: 67.9 % were female, mean age was 45.8 +/- 14.9 years. The most frequently detected symptoms were sore throat (74.2 %), fatigue (71.6 %), and neck swelling (56.3 %). The most common form of tularemia was oropharyngeal (82.6 %) and glandular (14.2 %). The most used monotherapy was ciprofloxacin (80.5 %, n = 136), and combination therapy was streptomycin-ciprofloxacin (81.0 %, n = 17). Treatment failure was observed in 29 patients (15.2 %). No difference was found between patients who responded and didn't respond to treatment regarding laboratory parameters. Lymph node drainage or excision was performed in 47 patients (23 %). Suppurative lymphadenitis, abscess, necrosis, and conglomerate lymphadenopathy were more common in the lymph node drainage group. Reactive lymph nodes were more common in the group without lymph node drainage. There was no difference between the two groups regarding laboratory parameters of patients with and without lymph node drainage. The duration of antibiotic treatment was longer in patients who underwent lymph node drainage than in those who didn't. Conclusion: Radiological evaluation of lymph nodes upon hospital admission, in addition to antibiotic therapy during treatment, may help predict which patients are more likely to require surgical drainage. Laboratory parameters may not provide significant benefits in predicting the need for lymph node drainage and long-term treatment did not affect the treatment response
Microalgae to Biofuel: Cutting-Edge Harvesting and Extraction Methods for Sustainable Energy Solution
No full textThe increasing price and demand for fossil fuels are driven by their depletion, greenhouse gas emissions, and industrial air pollution. As a result, the search for renewable alternatives has gained serious attention. Microalgae provide a sustainable alternative for biofuel production, offering high growth rates, significant oil yields and productivity, nontoxic nature, higher photosynthesis efficiencies, and the ability to thrive on nonarable land. Chlorella vulgaris and Scenedesmus dimorphus strains were chosen for this study to develop effective harvesting and oil extraction methods for sustainable energy. Three types of harvesting methods are used to optimize slurry yields, viz. flocculation, high-speed refrigerated centrifugation, and microfiltration. Moreover, two oil extraction methods were considered to enhance efficiency: Soxhlet extraction and the direct boiling method. The centrifugation method provides the fastest harvesting rate and highest slurry yields, followed by membrane separation, while flocculation, though slower, is more cost-effective and easier to perform. The direct boiling method optimizes the oil extraction process by effectively rupturing microalgae cell walls. Chlorella vulgaris shows a slurry recovery efficiency of 0.76 g per liter of media by centrifuge, consisting of 12%–40% oil content in overall weight; 12.7% of the oil was extracted using Soxhlet extraction, and 18.7% was extracted using the direct boiling method. On the other hand, Scenedesmus dimorphus shows better slurry recovery efficiency of 0.81 g per liter media by centrifuge, consisting of 22%–51% oil content in overall weight, and there is 23.8% oil extracted by using soxhlet extraction and 26.4% for every 10 g of the sample by direct boiling method compared to Chlorella vulgaris. Future research should focus on cost-effective harvesting and oil extraction methods for microalgae like Chlorella vulgaris and Scenedesmus dimorphus to reduce production costs, maximize biofuel yields, and tackle the global energy crisis. © 2025 The Author(s). Energy Science & Engineering published by Society of Chemical Industry and John Wiley & Sons Ltd
Development of new methods for monitoring patulin contamination in fruit and juice and their analytical applicability
No full textBu çalışma meyve ve meyve sularında patulin bulaşmasının izlenmesi için yeni yöntemlerin geliştirilmesi ve bunların analitik uygulanabilirliğini araştırmak amacı ile yapılmıştır. Numunelerin sıvı-sıvı ekstraksiyon yöntemi kullanılarak zenginleştirilmesi sonrası patulin tayini için yöntem geliştirilmiştir. Patulin analizi için yaş meyvelerden Cimin üzümü, İncaz eriği, şeftali, kuru meyvelerden ise kayısı, erik ve üzüm ile Cimin üzümünden üretilen farklı yıllara ait iki şaraptan elde edilen numuneler kullanılmıştır. Çalışmada patulin analizinde, Kuadrupol-Uçuş Zamanlı Sıvı Kromatografisi-Kütle Spektrometresi (Q-TOF LC-MS), Yüksek Performanslı Sıvı Kromatografisi (HPLC) ve Ultraviyole-Görünür bölge (UV-VIS) spektrofotometresinden yararlanılmıştır. Bütün deneysel çalışmalara geçilmeden önce analiz dalga boyu, tampon pH'sı, tampon hacmi, patulin hacmi ve boyar madde hacmi gibi optimum koşullar belirlenmiştir. Deneysel koşulların optimizasyonu sonrası, UV-VIS için; 0.5-25 μg L-1 doğrusal çalışma aralığında 85 katlık iyileştirme faktörüne ulaşılmıştır. Yöntemin gözlenebilme (3σ/m) ve tayin (10σ/m) sınırları sırasıyla 0.19 ve 0.65 μg L−1 olarak belirlenmiştir. Kesinliğin bir ölçütü olarak bağıl standart sapma (%BSS), %2.01-3.56 aralığında bulunmuştur.This study was conducted with the aim of developing new methods for monitoring patulin contamination in fruits and fruit juices and their analytical applicability. A method has been developed for patulin determination after enrichment of samples using the liquid-liquid extraction method. For patulin analysis, samples of fresh fruits such as Cimin grape, İncaz plum, and peach; and dried fruits such as apricot, plum, peach, and grape; and two wines produced from Cimin grape in different years were used. High Performance Liquid Chromatography (HPLC), Ultraviolet-Visible (UV-VIS) Spectroscopy, and Quadrupole Time-Of-Flight Liquid Chromatography-Mass Spectrometer (Q-TOF LC-MS) analyses were used in the study. Optimum conditions were determined before proceeding with all experimental studies. Before starting all experimental studies, optimum conditions such as analysis wavelength, buffer pH, buffer volume, patulin volume, and dye volume were determined. After the optimization of experimental conditions, for UV-VIS, an 85 fold improvement factor was achieved in the linear operating range of 0.5-25 μg L-1. The observability (3σ/m) and detection (10σ/m) limits of the method were determined as 0.19 and 0.65 μg L−1, respectively. Relative standard deviation (%BSS) as a measure of precision was found to be in the range of 2.01-3.56%