WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 1Citation - Scopus: 2Investigation of the Effects of Various Parameters on Wireless Power Transfer Efficiency(Elsevier Gmbh, 2025) Yilmaz, Mert; Cetkin, Erdal; Akca, HakanElectric vehicles have dominated the automotive market, especially in recent years. However, the charging problem that stresses drivers continues. Although conductive charging is an established technology, it still needs to meet user expectations fully. On the other hand, wireless charging technology attracts users' attention with dynamic charging features. Although this technology improves daily, efficiency is not at the desired level. In this study, a wireless power transfer system was designed for electric vehicles, and the factors affecting the charging efficiency were investigated. This system consists of an inverter, a compensation system, and a load. The efficiency of the system according to cable type, air gap, cooling, and pulse-width modulation parameters was observed through 40 experiments, each lasting 20 min. In addition to efficiency, the frequency behavior was also investigated. Experimental results were compared with models designed in MATLAB and ANSYS software. The average errors between the experimental and simulation results are 1.75, 2.03, 1.85, 1.58, and 2.00% for air gaps of 19-20, 55-56, 91-92, 127-128, and 145-146 mm, respectively. Power was transferred wirelessly with a minimum efficiency of 59.25% at a 145 mm air gap and a maximum efficiency of 85.74% at a 56 mm air gap in 300 W tests.Article Citation - WoS: 14Citation - Scopus: 17Cleaner Production of Biohydrogen Using Poplar Leaves: Experimental and Optimization Studies(Elsevier Sci Ltd, 2024) Goren, A. Yagmur; Kenez, Muratcan; Dincer, Ibrahim; Khalvati, AliBiohydrogen (bioH2) is recognized as a potential carbon-neutral energy vector, and developing novel methods has received increasing attention with a prime goal of producing H2 more efficient and cost effective manner. This study aimed to develop a unique reactor to investigate dark fermentative H2 production from poplar biomass using commercially available and inexpensive microorganism cultures. Therefore, six factors of the Box-Behnken design (BBD) were performed to evaluate the individual and combined effects of operational param-eters: acid concentration (2-10%), biomass concentration (2-10 g), initial pH (5-8), temperature (30-40 degrees C), mixing ratio (150-350 rpm), and microorganism concentration (2-6 g) on bioH2 production. Among the oper-ational parameters, the acid concentration was the most effective parameter on bioH2 production. The bioH2 production increased from 11.33 to 18.15 mg/g biomass with increasing acid concentration from 6 to 10%. Moreover, the optimum levels of operational variables were as follows: acid concentration of 9.9%, biomass amount of 2 g, pH of 6.56, temperature of 35 degrees C, mixing ratio of 345 rpm, and microorganism amount of 4.5 g for the highest bioH2 production of 20 mg/g-biomass according to the experimental design. Consequently, the bioH2 production performance of the dark fermentation process showed that bioH2 production from poplar biomass using commercially available microorganisms had a competitive advantage.Article Efficient Design of Nursing Unit Floors(Yıldız Teknik Üniversitesi, 2009) Kazanasmaz, Z. Tugce; Duzgunes, ArdaHospital designs aim to obtain the lowest possible construction, maintenance and operational costs together with patient satisfaction, comfort and privacy. To satisfy these needs, the efficient design of nursing unit areas becomes considerably important. This study was thus conducted to analyze planimetric design efficiency of nursing unit floors by defining certain floor areas and floor area ratios. To test existing nursing unit floors, quantitative assessments were noted in regard to their planimetric efficiency: the utility value of the built floor area, both in terms of its allocation to patient space (served), support (serving) and circulation space and the relative proportions of these. Results were presented in a comparative table. Of the 15 hospital floor plans analyzed, five satisfied minimum space requirements for patient areas, while another five were in the optimum range for circulation areas. Two were defined as the least efficient, having the lowest patient-to-circulation area ratio.