Browsing by Author "Mercan, Elif"

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Open Access
A corpus-based approach to define Turkish soundscapes attributes
(Acoustical Soc Amer Amer Inst Physics, 2023-03) Yılmazer, Semiha; Dalirnaghadeh, Donya; Fasllija, Ela; Alimadhi, Enkela; Şahin, Zekiye; Mercan, Elif
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A principal component model to identify Turkish soundscapes’ affective attributes based on a corpus-driven approach
(Elsevier, 2023-06-30) Yılmazer, Semiha; Fasllija, Ela; Alimadhi, Enkela; Şahin, Zekiye; Mercan, Elif; Dalirnaghadeh, Donya
This study focused on achieving linguistic and culturally appropriate equivalents of Turkish soundscape attributes present in ISO 12913–3 by incorporating a Corpus-Driven Approach (CDA). A two-phase experiment was set up to find Turkish equivalents of affective quality attributes. The first phase consisted of the formation of a Corpus. An online questionnaire was prepared and sent to 196 native Turkish speakers from all around Türkiye to define adjectives. The second phase of the experiment was performed in a listening room. For this purpose, twenty-four binaural sound recordings were collected from seven public spaces. Afterward, forty individuals evaluated the recordings by using the attributes from Phase 1. The perceptual dimensions were obtained from the generated corpus in Turkish based on a rating scale by applying the Principal Component Analysis (PCA). Results indicated a two-dimensional model with two main components, Pleasantness and Eventfulness. Each component is associated with a main orthogonal axis denoted by ‘annoying-comfortable’ and ‘dynamic-uneventful,’ respectively. This circular organization of soundscape attributes is supported by two derived axes, namely ‘chaotic-calm’ and ‘monotonous-enjoyable’, rotated 45°on the same plane. Additionally, by using Spearman's rank correlation coefficient, sixty-four different bipolar adjective pairs were found. The adjective pairs showed that the highest correlations are mainly on the pleasant-unpleasant continuum, namely Component 1 of PCA. The collected data were also analyzed using Agglomerative Hierarchical Cluster analysis with the Ward method in R programming language to cluster the adjectives. The results inferred that there are four top-level categories. From the first to the fourth level, categories consisted of pleasant, uneventful, eventful, and annoying adjectives, respectively. Moreover, the terms grouped on the first cluster found their dichotomous on the fourth cluster, while maintaining the same relationship in the pleasant-unpleasant continuum.
Open Access
The effect of iron on the surface graphitization of silicon carbide
(World Scientific, 2020) Mercan, Elif; Cambaz-Büke, G.
In order to decrease the decomposition temperature of SiC, 12nm Fe thin film is applied on SiC substrates as a catalyst layer using electron beam (e-beam) deposition. To investigate the mechanism of Fe-treated SiC decomposition, local Fe regions are formed through dewetting of the catalyst layer by hydrogen annealing. The results show that Fe decreases the decomposition temperature of SiC effectively and increases the kinetics of the graphitization. Studies showed that depending on the amount of Fe, crumpled and ordered graphene films can be synthesized simultaneously on SiC by using this method.
Open Access
Production of aerogel-modified expanded perlite aggregate and clay (AEP/C) board and investigation of physical and mechanical properties
(2021-08) Mercan, Elif
Expanded perlite aggregate (EPA) is an inorganic insulation material preferred because of its low thermal conductivity. In other respects, it has disadvantages in buildings because of its high moisture retention, sintering in case of fire, and fragility. This study aims to produce a clay-based insulation board by eliminating these disadvantages of EPA with aerogel modification. The sol-gel method was chosen, allowing low-cost aerogel synthesis in a laboratory and permitting the control of parameters throughout the process. The optimum synthesis process was designed by examining the acid and base variables in the process. The recipe obtained at the aerogel synthesis was used to constitute aerogel-modified expanded perlite aggregate (AEP). AEP particles were prepared with clay matrix under determined process conditions, and characterization tests were carried out. According to the results, aerogel modification prevents high-temperature sintering of EPAs. The AEPs and the aerogel-modified expanded perlite aggregate and clay (AEP/C) composites' density remained almost unchanged compared to the EPA and expanded perlite aggregate and clay (EP/C) control samples. Thus, this can be offered that the prepared boards are lightweight and can maintain low thermal conductivity. The results showed that the mechanical strength of the boards was slightly higher than the control samples and the aerogel modification has almost no effect on mechanical strength.
Open Access
Study of physical and mechanical properties of aerogel-modified expanded perlite aggregate and clay (AEP/C) board
(Elsevier, 2022-12-26) Mercan, Elif; Yilmazer, Semiha
The aerogel-modified expanded perlite aggregate and clay (AEP/C) composite boards were produced, and physical and mechanical properties were investigated. The aerogel modification of expanded perlite aggregate was carried out with optimization of the two-step acid-base catalyzed sol–gel method. The perlite shrinkage under high-temperature annealing was prevented by covering perlite surfaces with aerogel modification. The boards with aerogel-modified expanded perlite aggregate (AEP) wrapped by clay matrix were successfully produced. The unit volume mass (UVM) and specific gravity (SG) of AEP/C boards slightly increased to 0.55 ± 0.01 g/cm3 and 2.36 ± 0.01, respectively. On the other hand, produced AEP/C boards’ volume of voids of 36.23 ± 1.05 and water absorption (WA) of 83.91 ± 0.49 % were moderately lower than EPA/C. The mechanical strength of the AEP/C composite boards remained almost unchanged with 0.73 ± 0.04 N/mm2, and the aerogel modification had practically no effect on the mechanical strength of composite boards.