Materials Science and Engineering / Malzeme Bilimi ve Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4719
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Article Citation - WoS: 20Citation - Scopus: 22Fabrication and Properties of Novel Porous Ceramic Membrane Supports From the (sig) Diatomite and Alumina Mixtures(Elsevier, 2022) Aouadja, Faycal; Bouzerara, Ferhat; Güvenç, Çetin Meriç; Demir, Mustafa M.In this paper, the manufacturing of macro-porous tubular ceramic supports for membranes is described. The novel supports are fabricated from natural diatomite and alumina raw materials using the extrusion method. The structure was analyzed by X-ray diffraction (XRD) and mercury porosimetry techniques; the presence of possible defects was investigated by scanning electron microscopy (SEM). The permeability has been measured from water flux in standard experiments. Experimental results show that the open porosity, the average pore size (APS), the pore size distribution, the strength, and the permeability of sintered supports, have been found to depend, mainly on the concentration of alumina (Al2O3) additive. Supports prepared with the addition of 10 wt.% of alumina and sintered at 1200 degrees C, can be considered as the most optimized; they have a porosity ratio of about 46%, an APS is around 7.7 mu m, a flexural strength value of about 28 MPa, and water permeability of around 15 m(3)h(-1) m(-2) bar(-1). Such materials could be of great interest in the supports fabrication for membrane application, for instance, water filtration. (C) 2021 SECV. Published by Elsevier Espana, S.L.U.Article Citation - WoS: 49Citation - Scopus: 52Advances in Electrospun Fiber-Based Flexible Nanogenerators for Wearable Applications(Wiley-VCH Verlag, 2021) Arıca, Tuğçe Aybüke; Isık, Tuğba; Güner, Tuğrul; Horzum, Nesrin; Demir, Mustafa M.In today's digital age, the need and interest in personal and portable electronics shows a dramatic growth trend in daily life parallel to the developments in sensors technologies and the internet. Wearable electronics that can be attached to clothing, accessories, and the human body are one of the most promising subfields. The energy requirement for the devices considering the reduction in device sizes and the necessity of being flexible and light, the existing batteries are insufficient and nanogenerators have been recognized a suitable energy source in the last decade. The mechanical energy created by the daily activities of the human body is an accessible and natural energy source for nanogenerators. Fiber-structured functional materials contribute to the increase in energy efficiency due to their effective surface to volume ratio while providing the necessary compatibility and comfort for the movements in daily life with its flexibility and lightness. Among the potential solutions, electrospinning stands out as a promising technique that can meet these requirements, allowing for simple, versatile, and continuous fabrication. Herein, wearable electronics and their future potential, electrospinning, and its place in energy applications are overviewed. Moreover, piezoelectric, triboelectric, and hybrid nanogenerators fabricated or associated with electrospun fibrous materials are presented.Article Citation - WoS: 5Citation - Scopus: 7Effect of High Salinity and Temperature on Water-Volcanic Rock Interaction(Springer, 2021) Gören, Ayşegül Yağmur; Gören, Ayşegül Yağmur; Topçu, Gökhan; Demir, Mustafa Muammer; Demir, Mustafa M.; Baba, Alper; Baba, AlperIn order to understand the processes occurring in natural hydrothermal systems, it was carried out a series of water-volcanic rock interaction studies in the laboratory and an intermediate volcanic rock samples from geothermal production wells in Tuzla geothermal field (TGF) in western Turkey. A high-pressure autoclave was used to conduct water-rock interaction experiments under similar conditions of the field. Rainwater and seawater were treated with volcanic rocks at 140 degrees C (reservoir temperature) and 4.5 bar pressure. The change in the ionic content of the resulting fluids was examined in terms of the type of volcanic rocks and mineral saturation index. The results indicate that talc and diopside minerals in geothermal systems may cause scaling at high temperatures depending on the geothermal fluid and pH.
