Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1Citation - Scopus: 1Pressureless Joining of Soda Lime Silicate Glass Using Polysilazane-Derived Silica at Near-Room Temperature(Elsevier Sci Ltd, 2025) Karacasulu, Levent; Biesuz, Mattia; Pastorelli, Virginia; Vakifahmetoglu, Cekdar; Sglavo, Vincenzo M.; Ferraris, Monica; Soraru, Gian D.Perhydropolysilazane (PHPS) pre-ceramic polymer was used to join soda lime silicate glass at temperatures below 200 degrees C under pressureless conditions. The results show that: (i) the junction material is largely converted to silica at 100 degrees C and fully converted to glass at 150 degrees C; (ii) the samples treated at room temperature and 100 degrees C show a perfectly dense and clean bond, whereas porosity develops starting from 150 degrees C as a result of the hydrolysis reactions and solvent evaporation; (iii) a maximum tensile bond strength of about 5-6 MPa is obtained after treatments at 100 degrees C. Remarkably, after treatment at 500 degrees C, the junction remains intact. These preliminary findings provide the first successful attempt regarding the use of PHPS as a joining material to produce inorganic and transparent bonds for glass at relatively low temperatures.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: 37Citation - Scopus: 41Processing and Characterization of Geopolymer and Sintered Geopolymer Foams of Waste Glass Powders(Elsevier, 2021) Polat, Dilan; Güden, MustafaGeopolymer foams of fine and coarse waste glass (WG) powders were prepared using an activation solution of NaOH (8 M) and Na2SiO3. The effects of WG powder particle size, solid/liquid ratio (S/L = 1, 1.5, and 2) and Al foaming agent content (2-20 wt%) on the expansion and temperature behavior of the slurries were determined in-situ using a laser sensor and a thermocouple, respectively. The geopolymer foams processed using a coarse WG powder slurry, S/L = 2, and 2 wt% Al, were further sintered at 600, 700, 725, and 750 degrees C. The compression strengths and thermal conductivities of the geopolymer and sintered geopolymer foams were also determined. The slurry expansions continued until about a maximum, and the temperatures of the slurries increased to a maximum, 85-88 degrees C. At the maximum temperature, the slurry evaporation and the resultant increase in the S/L ratio limited the slurry expansion. Increasing the Al content decreased the final density of the foams (238-555 kg m-3), while the coarse powder slurries resulted in lower densities than the fine powder slurries. Three crystal phases, muscovite, sodium aluminum silicate hydrate, and thermonitrite, were determined in the geopolymer foams. The muscovite formation was noted to be favored at high S/L ratios. During sintering, the partial melting of glass particles started after about 700 degrees C, while sintering above this temperature decreased the final density of the foams. The reduced density above 700 degrees C was ascribed to the release of CO2 due to the decomposition of thermonitrite. Both the compressive strength and thermal conductivity of the geopolymer and sintered geopolymer foams increased with increasing foam density. The highest increase in the compressive strength and reduction in the density were seen in the geopolymer foams sintered at 750 degrees C.Book Part Citation - Scopus: 2Influence of Filler Surface Modification on the Properties of Pp Composites(Wiley, 2015) Balköse, DevrimThis chapter reviews the fillers have been grouped as silica, glass, silicates, magnesium hydroxide and eggshell, cellulose and carbon, and their surface modification techniques. It explains the effects of the surface modification of fillers on the properties of composite materials having polypropylene as the matrix. The surface modification of fillers affects the properties of the polypropylene matrix composites in different aspects depending on the types of the filler and the modifications. The polypropylene phase was also functionalized by treating PP with MA or ammines. The properties most affected are the tensile strength, Young modulus, and elongation at break of the composites. If crosslinking occurs between the filler and functionalized PP, the tensile strength increases and elongation at break decreases owing to decrease in mobility. PP crystallite formation at the interface also increases the adhesion between filler and matrix. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 6The Expansion Behavior of Slurries Containing Recycled Glass Powder Carboxymethyl Cellulose, Lime and Aluminum Powder(Elsevier, 2020) Zeren, Doğuş; Şentürk, Ufuk; Güden, MustafaThe rheology and foaming/expansion of the slurries of a waste/recycled glass powder with 50, 55 and 60 wt% of solid (glass powder) were experimentally investigated. The glass powder slurries were foamed using aluminum powder as foaming agent (0.75 wt%) and calcium hydroxide as activator (1 wt%). Sodium carboxymethyl cellulose (CMC) was added to the slurries as a binder with the amounts between 0 and 4 wt%. The expansions of the slurries were measured in-situ using a laser sensor and reported as percent volume expansion. The CMC-addition increased the viscosities of the slurries, particularly the fine size powder slurries. The slurries with the relatively low-viscosity exhibited lower initial expansion rates compared to the slurries with the relatively high-viscosity. The maximum expansions of the slurries increased from 300 to 350%, when the viscosity increased to 5 Pa s and reached a steady value around 400% between 5 and 50 Pa s. The expansions of the slurries could not be achieved above 50 Pa s since they became too thick to be foamed. The foam samples made from the slurries with 55 and 60 wt% of solid and sintered at 700 and 750 degrees C for 30 min had the average densities between 355 and 530 kg m(-3) and the average compressive strengths between 0.2 and 0.5 MPa. Increasing sintering time to 60 min at 750 degrees C increased the average compressive strength from 0.5 to 1.5 MPa for the foam samples made from the slurry with 60 wt% of solid. These proved that both sintering temperature and time were effective in increasing the compressive strengths of the foamed structures. The thermal conductivities of the sintered foam samples with the densities of 355 and 504 kg m(-3) were measured 0.042 and 0.057 W m(-1) K-1, respectively. (C) 2019 Elsevier Ltd. All rights reserved.Article Citation - WoS: 49Citation - Scopus: 52What Will It Take To Adopt Smart Glasses: a Consumer Choice Based Review?(Elsevier Ltd., 2017) Başoğlu, Ahmet Nuri; Ok, Ali Emre; Daim, Tuğrul U.Wearable technologies have become a reality already. Their impact in some fields has already been seen. We explore the factors which are important and help the adoption of these technologies. Specifically we study the adoption factors of smart glasses. Technology adoption process depends on preferences and needs of people who use the systems under study. We explore these phenomenon through two frameworks: Product Characteristics and User Intention Characteristics. The purpose of the first framework is to examine the effects of smart glass design features; Stand-alone device, field of view, interaction, price, and display resolution on user preference through an experimental study and we use conjoint analysis. The second framework explore many more factors such as self-efficacy, anxiety, involvement, risk-task characteristics, enjoyment, usefulness, ease of use, attitude and intention. A web survey supplemented by visual aids was used.Conference Object Citation - WoS: 8Citation - Scopus: 10Exploring Adoption of Smart Glasses: Applications in Medical Industry(Institute of Electrical and Electronics Engineers Inc., 2017) Göken, Müge; Başoğlu, Ahmet Nuri; Dabic, MarinaThis research is a study exploring the utilization of smart glasses by physicians and their adoption to these products in medical industry. Although varied smart glasses were examined in the process by literature review, in whole work M100 was used as a physical product. In this research study, three research methods were applied. These are semi-structured in-depth interview, expert focus group work and experimental study 95 constructs were extracted from literature review and interviews by physicians. Approximately 40 most significant constructs were selected by physicians in the expert focus group work. At the end, 75 physicians answered a survey related with these 40 constructs. Furthermore, these constructs include the most significant design inputs of smart glasses for the expert group. The survey included approximately 50 questions. According to survey and results of multiple regression analyses; it is revealed that compatibility, ease of reminding, speech recognition and ease of use affect usefulness positively. Moreover, ease of learning, ease of medical education, external influence and privacy affect ease of use positively too. In addition, usefulness, ease of use affect attitude and attitude affects intention. To sum up, designers should focus on these design inputs at the first stage of product development process of smart glasses for physicians.Conference Object Citation - WoS: 11Citation - Scopus: 23Exploring the Design Factors of Smart Glasses(Institute of Electrical and Electronics Engineers Inc., 2015) Ok, Ali Emre; Başoğlu, Ahmet NuriAdvances in information technology (IT) have started to focus studies on human computer interaction (HCI) which is an area in computer science embracing cognitive science. In this approach there are various aspects of researches about HCI in order to explore how people design, implement, and use interactive computer systems and how computers affect individuals, organizations, and society. This study represents exploring the adoption factors of smart glasses. Technology adoption process establishes preferences and needs of people who use computers and smart systems. To address this issue, technology adoption is essential for a rapidly changing world where technology has become central to our lives. In that context, user interface (UI) which provides interaction between user and computer, plays significant role for technology adoption process. The purpose of the study is to examine the effects of smart glass design features; Stand-alone device, field of view, interaction, price, and display resolution on user preference through an experimental study by using conjoint analysis. In order to apply this study, an experimental study including a survey was designed. This survey also analyze social characteristics such as self-efficacy, anxiety, involvement, risk-task characteristics, enjoyment, usefulness, ease of use, attitude and intention for user smart glasses interaction.Conference Object Active Eye-Glasses With Local Dimming(Institute of Electrical and Electronics Engineers Inc., 2011) Özvural, Görkem; Gümüştekin, ŞevketThe sense of sight provides the most reliable information about the environment. Although the human eye has a wide dynamic range for brightness adaptation, direct exposure to relatively bright light sources wipes out the total visual perception. The most remarkable example of this situation is driving a car at night, while the other cars are coming from the opposite lane with headlights on. In this work, we have proposed and developed a set of LCD equipped active glasses to solve this light adaptation problem. First, the location of the light sources are determined using an on board camera which is assembled in front of the glasses. After processing image data, the locations of the bright light sources are darkened and the disturbing effect of intense light sources is reduced. © 2011 Chamber of Turkish Electric.Article Citation - WoS: 60Citation - Scopus: 70Foam Glass Processing Using a Polishing Glass Powder Residue(Elsevier Ltd., 2013) Attila, Yiğit; Güden, Mustafa; Taşdemirci, AlperThe foaming behavior of a powder residue/waste of a soda-lime window glass polishing facility was investigated at the temperatures between 700 and 950 °C. The results showed that the foaming of the glass powder started at a characteristic temperature between 670 and 680 °C. The maximum volume expansions of the glass powder and the density of the foams varied between 600% and 750% and 0.206 and 0.378 g cm−3, respectively. The expansion of the studied glass powder residue resulted from the decomposition of the organic compounds on the surfaces of the glass powder particles, derived from an oil-based coolant used in the polishing. The collapse stress of the foams ranged between ∼1 and 4 MPa and the thermal conductivity between 0.048 and 0.079 W K−1 m−1. Both the collapse stress and thermal conductivity increased with increasing the foam density. The foams showed the characteristics of the compression deformation of the open cell brittle foams, which was attributed to the relatively thick cell edges.