Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article An Improvement in the Design Process of Sustainable Peak Power Rating Transformer for Solar Utility(Elsevier Sci Ltd, 2025) Yukselen, Emir; Rahimpour, EbrahimThe transformer industry faces critical challenges, such as maintaining reliable production while meeting rising sustainability requirements. This paper introduces a significant advancement in the design and optimization of a transformer dedicated to a photovoltaic power plant, which exhibits a unique loading cycle distinct from standard power and distribution transformers. The main aim is to minimize the carbon footprint by enhancing the design process to improve operational performance, efficiency, and functional reliability. Such upgrades are essential for transitioning to a zero-emission electricity system and developing green energy projects. In this paper, a transformer has been studied using a combination of electrical design and 3D finite element method simulation to evaluate various design parameters. An optimization study has been conducted using an innovative multi-objective genetic algorithm utilizing a cost function that factors in size and material costs to identify the most efficient and cost-effective design solutions. The proposed design method was then validated through thermal model simulations and experimental tests based on the photovoltaic load cycle. A comparison of critical thermal parameters directly affecting the transformer's lifetime and reliability was also drawn. The results were consistent with the expected outcomes, confirming the effectiveness and reliability of the proposed design methodology.Article Citation - WoS: 25Citation - Scopus: 28Soundscape Descriptors in Eighteen Languages: Translation and Validation Through Listening Experiments(Elsevier Sci Ltd, 2024) Aletta, Francesco; Mitchell, Andrew; Oberman, Tin; Kang, Jian; Khelil, Sara; Bouzir, Tallal Abdel Karim; Nguyen, Thu LanThis paper presents the outcomes of the "Soundscape Attributes Translation Project" (SATP), an international initiative addressing the critical research gap in soundscape descriptors translations for cross-cultural studies. Focusing on eighteen languages - namely: Arabic, Chinese, Croatian, Dutch, English, French, German, Greek, Indonesian, Italian, Japanese, Korean, Malay, Portuguese, Spanish, Swedish, Turkish, and Vietnamese - the study employs a four-step procedure to evaluate the reliability and cross-cultural validity of translated soundscape descriptors. The study introduces a three-tier confidence level system (Low, Medium, High) based on "adjusted angles", which are a measure proposed to correct the soundscape circumplex model (i.e., the pleasant-eventful space proposed in the ISO 12913 series) of a given language. Results reveal that most languages successfully maintain the quasi-circumplex structure of the original soundscape model, ensuring robust cross-cultural validity. English, Arabic, Chinese (Mandarin), Croatian, Dutch, German, Greek, Indonesian, Italian, Spanish, Swedish, and Turkish achieve a "High" confidence level. French, Japanese, Korean, Malay, Portuguese, and Vietnamese demonstrate varying confidence levels, highlighting the importance of the preliminary translation. This research significantly contributes to standardized cross-cultural methodologies in soundscape perception research, emphasizing the pivotal role of adjusted angles within the soundscape circumplex model in ensuring the accuracy of dimensions (i.e., attributes) locations. The SATP initiative offers insights into the complex interplay of language and meaning in the perception of environmental sounds, opening avenues for further crosscultural soundscape research.Article Citation - WoS: 19Citation - Scopus: 19Translation of Soundscape Perceptual Attributes From English To Turkish(Elsevier Sci Ltd, 2023) Yorukoglu, P. N. Dokmeci; Bayrak, O. Turker; Coban, N. Akbulut; Osma, U. B. Ercakmak; Aletta, F.; Oberman, T.; Kang, J.; Dökmeci Yörükoğlu, P.N.; Erçakmak Osma, U.B.; Türker Bayrak, Ö.; Akbulut Çoban, N.The International Standard Organization (ISO) published the standard series on soundscape for the identification, data collection and data analysis. However, since all these standards are in English language, the reliable standardized usage in other languages and its applicability is questionable. Thus, this two-staged study aims: i) to determine the Turkish equivalences of the 8 soundscape perceptual attributes that are published in ISO/TS 12913-2:2018 and ISO/TS 12913-3:2019, ii) to analyze if the determined Turkish attributes have concept equivalence to the original ones, and iii) to determine if the translated Turkish scale is reproducible. The first stage involved the translation of the attributes by focus group discussions and finalization by Turkish linguistic experts. As a result, the attributes 'eventful', 'vibrant', 'pleasant', 'calm', 'uneventful', 'monotonous', 'annoying', and 'chaotic' are translated to Turkish as 'hareketli', 'coskulu', 'keyifli', 'sakin', 'duragan', 'tekduze', 'rahatsiz edici', and 'karmasik', respectively. The second stage involves the analysis of reproducibility in terms of inter-rater reliability and conceptual validity. It is found that the Turkish scale is reproducible based on high inter-rater reliability in all attri-butes. Context validity at a conceptual level is analyzed both in terms of the difference between the aver-age scores given to the English attributes and their corresponding Turkish equivalences and the correlation between the English and Turkish scores given to each attribute. The highest difference between the average scores (around 10 points on a slider scale of 0 to 100) is found to be in the translation of 'vibrant' while the lowest correlated one (slightly lower than 0.5) is found in 'chaotic' attribute as in line with literature. Despite this result, when the scores are reduced to 2 dimensions as pleasantness and eventfulness, it is seen that there is a high correlation between the English and Turkish scales. It is considered that the results obtained from this research could act as a base in the future for the establishment of Turkish Standards on soundscape and standardization of the translated and validated Turkish soundscape perceptual attributes and the 'perceived affective quality' scale defined under ISO/TS 12913-2:2018 in English. (c) 2023 Elsevier Ltd. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7Experimental Investigation Into the Effect of Magnetorheological Fluid Damper on Vibration and Chatter in Straight Turning Process(Elsevier Sci Ltd, 2023) Nasab, Vahid Hasan; Akar, Samet; Batako, Andre; Emami, MohsenMagneto-Rheological (MR) dampers have received a great deal of attention in recent years due to the potential of offering semi-active control. MR dampers have been successfully applied in the vibration control of several machining processes. However, the effect of the material of the damper's fluid chamber on its magnetic prop-erties has not been studied much. In this study, an MR damper has been designed to control the chatter vibration of the straight turning operation. The magnetic properties of the MR damper are simulated in the FEM software COMSOL Multiphysics with two types of steel AISI 410 and AISI 1018, and the material with the best perfor-mance for constructing the fluid chamber is determined. Then, the MR damper with an assembly to hold the cutting tool was fabricated and experimentally tested during straight turning operation and its effect on the tool vibration, and work surface roughness was analyzed. From the result, it was observed that the MR damper reduced tool vibration and chatter effectively. The results obtained in this research confirm that the application of the MR damper in the straight-turning process can either suppress the chatter or greatly reduce the frequency amplitude of the chatter. The reduction of the tool's acceleration amplitude with the MR damper was more intense in the condition of chatter suppression and reached up to 89.42 %. Moreover, the MR damper reduced the roughness of the machining surface. This reduction was higher in cases where the chatter was suppressed and it was observed up to 29 %.Article Citation - WoS: 38Citation - Scopus: 40Study of Impulsive Problems Under Mittag-Leffler Power Law(Elsevier Sci Ltd, 2020) Shah, Kamal; Jarad, Fahd; Abdo, Mohammed S.; Abdeljawad, ThabetThis article is fundamentally concerned with deriving the solution formula, existence, and uniqueness of solutions of two types of Cauchy problems for impulsive fractional differential equations involving Atangana-Baleanu-Caputo (ABC) fractional derivative which possesses nonsingular Mittag-Leffler kernel. Our investigation is based on nonlinear functional analysis and some fixed point techniques. Besides, some examples are given delineated to illustrate the effectiveness of our outcome.Article Numerical investigation on the performance of a small scale solar chimney power plant for different geometrical parameters(Elsevier Sci Ltd, 2020) Özgirgin Yapıcı, Ekin; Nsaif, Osama; Aylı, Ece; Yapici, Ekin OzgirginIn recent decades, demand for energy has been significantly increased, and considering environmental impacts and the degrading nature of fossil fuels, clean and emission-free renewable energy production has attracted a great deal of attention. One of the most promising renewable energy sources is solar energy due to low cost and low harmful emissions, and from the 1980s, one of the most beneficial applications of solar energy is the utilization of solar chimney power plants (SCPP). A SCPP is a simple and reliable system that consists of three main components; a solar collector, a chimney (tower) and a turbine to utilize electrical energy. Recently, by the advancement in computer technology, the use of CFD methodology for studying SCPP has become an extensive, robust and powerful technique. In light of the above, in this study, numerical simulations of a SCPP through three-dimensional axisymmetric modeling is performed. A numerical model is created using CFD software, and the results are verified with an experimental study from the literature. After ensuring good agreement with the experiments, chimney's and collector's geometric parameters effects and different configurations effects on SCPP performance, simultaneously and additively is investigated. The study introduces an insight to the performance enhancement methods and finding the best configuration of a SCPP model, which will be the basis of a detailed prototyping process. Based on the numerical results, the best configuration of the SCPP has been found as the diverging chimney which enhances the generated power. The results of the study showed that the chimney height and collector radius increase has a positive effect on the power output and efficiency of the system, but when construction and material costs are also considered, each has an optimal value. The maximum impact on the performance is found to be by the chimney tower radius and the collector height and inclination are found to have optimum values considering performance. According to the obtained results, the best performance for the SCPP was obtained with 3.5 m chimney height, 30 cm tower diameter, 400 cm of collector diameter with 6 cm height and zero inclination angle. By the correct selection of the dominant performance parameter which can be done by correctly interpreting the results of this study, "the best" design of a SCPP real scale prototype considering maximum power requirement can be done. (C) 2020 Elsevier Ltd. All rights reserved.Article Citation - WoS: 21Citation - Scopus: 24Exploration of Dual Solutions for an Enhanced Cross Liquid Flow Past a Moving Wedge Under the Significant Impacts of Activation Energy and Chemical Reaction(Elsevier Sci Ltd, 2020) Zaib, A.; Baleanu, Dumitru; Sheikholeslami, M.; Wakif, Abderrahim; Khan, UmairThe mathematical modeling and numerical simulation are conferred to offer the novel perception of binary chemical reaction with an activation energy aspect on magneto flow comprising Cross liquid inspired by a moving wedge. The influences of Soret and Dufour are also presented. The similarity procedure is utilized to modify the leading PDEs into a non-linear system of ODEs and then analyzed through a significant technique namely bvp4c based on the collocation method. The impacts of varying distinct parameters under the temperature and the velocity distribution are explored and discussed with the support of the graphs. The outcomes indicate that the multiple results are attained for a specific amount of shrinking/stretching constraint. Furthermore, the Weissenberg number reduces the skin factor and speed up the heat and mass transport rate in the lower and upper branch solutions. Also, an assessment of current results with earlier published literature is made in the limiting case.Article Citation - WoS: 24Citation - Scopus: 27Evaluation of Soil-Structure Interaction Effects From System Identification of Structures Subject To Forced Vibration Tests(Elsevier Sci Ltd, 2019) Tileylioglu, Salih; Givens, Michael J.; Mylonakis, George; Stewart, Jonathan P.; Star, Lisa M.We describe procedures to evaluate the dynamic properties of test structures subject to forced vibration testing. We seek modal vibration periods and damping ratios corresponding to the actual flexible-based response of the structure (incorporating the effects of compliance in the soil medium supporting the foundation) and similar attributes for a fixed-base condition in which only the flexibility of the structure is represented. Our approach consists of using suitable input and output time series with conventional parametric system identification procedures, and as such extends previously developed procedures for use with earthquake recordings. We verify the proposed approach and demonstrate its application using data from two test structures supported on shallow foundations that have been used in forced vibration tests and that have recorded earthquakes. The structures were tested with and without braces to modify their stiffness and were deployed at two sites with different soil conditions. We analyze the results to evaluate experimental period lengthening ratios and foundation damping. The results show (1) strong increases in period lengthening and foundation damping with the wave parameter (dimensionless ratio of structure-to-soil stiffness), (2) compatibility between modal properties from forced vibration testing and earthquake excitation, (3) soil nonlinearity increases period lengthening and modifies foundation damping in a manner that can be reasonably captured in predictive models using equivalent-linear soil properties compatible with a proposed shear strain index.Article Citation - WoS: 34Citation - Scopus: 39Wavelet Based Flickering Flame Detector Using Differential Pir Sensors(Elsevier Sci Ltd, 2012) Toreyin, B. Ugur; Soyer, E. Birey; Inac, Ihsan; Gunay, Osman; Kose, Kivanc; Cetin, A. Enis; Erden, FatihA Pyro-electric Infrared (FIR) sensor based flame detection system is proposed using a Markovian decision algorithm. A differential PIR sensor is only sensitive to sudden temperature variations within its viewing range and it produces a time-varying signal. The wavelet transform of the FIR sensor signal is used for feature extraction from sensor signal and wavelet parameters are fed to a set of Markov models corresponding to the flame flicker process of an uncontrolled fire, ordinary activity of human beings and other objects. The final decision is reached based on the model yielding the highest probability among others. Comparative results show that the system can be used for fire detection in large rooms. (c) 2012 Elsevier Ltd. All rights reserved.