Gebze Institute of Technology
Gebze, Turkey

Gebze Institute of Technology ) is one of two institutes of technology founded in Turkey. It is a university for undergraduate and graduate studies and research activities located in a specifically selected area in Gebze, one of the most industrialized regions of the Marmara Region. Wikipedia.

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Agency: European Commission | Branch: FP7 | Program: MC-IAPP | Phase: FP7-PEOPLE-2013-IAPP | Award Amount: 921.57K | Year: 2014

This project combines sector-leading partners from clean energy projects to achieve allied goals. The project fosters cooperation between SOFC technologists, ceramic manufacturers and fuel cell academicians, to establish new ceramic fuel cell manufacturing capability in Europe for sustainable home energy solutions. It will validate the technical, social and commercial prospects of specific fuel cell products. The strategic long-term vision for the partners is to innovate and commercialise low-cost SOFCs for household energy generation, based on patented designs, integrated systems and prototypes developed in other EC, UK and TR projects. We envisage CHP systems will replace household boilers in a transition towards a hydrogen economy, and very early prototypes are already being ordered at very high cost (e.g. Eon and CFCL; This NewGenSOFC proposal builds on a previous IAPP project (RAPITSOFCs; 2006-8 in Turkey), and runs in parallel with several large collaborative FCH JU projects begun in Europe in 2011 to build prototypes based on microtubular solid oxide fuel cell (mSOFC) technology. The overall aim of this project is to achieve low-cost engineering solutions for SOFC technology with collaboration between a ceramic fuel cell producer SME (Adelan), a giant ceramics manufacturer OEM (Kale), and academic researchers (Gebze Higher Institute of Technology and the University of Birmingham). We believe this project creates unique scientific, engineering and commercial synergies between European Partners with complementary skill-sets. It is critical to securing the European supply chain of ceramic SOFC, diversifying supply from expensive and inferior suppliers. To support a growth industry, we will support international research training opportunities for young scientists to develop their careers in this field, and establish new MSc level programmes, online resources and outreach events.

Erbil H.Y.,Gebze Institute of Technology
Surface Science Reports | Year: 2014

A sessile drop is an isolated drop which has been deposited on a solid substrate where the wetted area is limited by the three-phase contact line and characterized by contact angle, contact radius and drop height. Although, wetting has been studied using contact angles of drops on solids for more than 200 years, the question remains unanswered: Is wetting of a rough and chemically heterogeneous surface controlled by the interactions within the solid/liquid contact area beneath the droplet or only at the three-phase contact line? After the publications of Pease in 1945, Extrand in 1997, 2003 and Gao and McCarthy in 2007 and 2009, it was proposed that advancing, receding contact angles, and contact angle hysteresis of rough and chemically heterogeneous surfaces are determined by interactions of the liquid and the solid at the three-phase contact line alone and the interfacial area within the contact perimeter is irrelevant. As a consequence of this statement, the well-known Wenzel (1934) and Cassie (1945) equations which were derived using the contact area approach are proposed to be invalid and should be abandoned. A hot debate started in the field of surface science after 2007, between the three-phase contact line and interfacial contact area approach defenders. This paper presents a review of the published articles on contact angles and summarizes the views of the both sides. After presenting a brief history of the contact angles and their measurement methods, we discussed the basic contact angle theory and applications of contact angles on the characterization of flat, rough and micropatterned superhydrophobic surfaces. The weak and strong sides of both three-phase contact line and contact area approaches were discussed in detail and some practical conclusions were drawn. © 2014 Elsevier Ltd. All rights reserved.

In the context of transboundary issues, this paper introduces a composite water resources allocation approach that integrates both game theory and Pareto frontier concepts over the case of the Euphrates and Tigris Rivers. The proposed approach searches for an acceptable and viable solution set over the Pareto Frontier Surface via game theory based rationality constraints. For this purpose, the used base model is the Euphrates and Tigris River Basin Model, which is a linear programming model maximizing net economic benefits while optimally allocating scarce water resources in the basin. Results indicate that game theory based strategies and associated constraints provide a determinative backbone for an efficient and effective use of generated Pareto Frontier Surfaces. Additionally, estimated marginal values imply that the upstream countries have upper hand positions regarding their geographic and climatic contexts. After all the generation schemes, it appears that Turkey is the critical partner for inclusion into any form of coalition in the Euphrates and Tigris River Basin. © 2012 Elsevier B.V.

Erbil H.Y.,Gebze Institute of Technology
Advances in Colloid and Interface Science | Year: 2012

A sessile drop is an isolated drop which has been deposited on a solid substrate where the wetted area is limited by a contact line and characterized by contact angle, contact radius and drop height. Diffusion-controlled evaporation of a sessile drop in an ambient gas is an important topic of interest because it plays a crucial role in many scientific applications such as controlling the deposition of particles on solid surfaces, in ink-jet printing, spraying of pesticides, micro/nano material fabrication, thin film coatings, biochemical assays, drop wise cooling, deposition of DNA/RNA micro-arrays, and manufacture of novel optical and electronic materials in the last decades. This paper presents a review of the published articles for a period of approximately 120 years related to the evaporation of both sessile drops and nearly spherical droplets suspended from thin fibers. After presenting a brief history of the subject, we discuss the basic theory comprising evaporation of micrometer and millimeter sized spherical drops, self cooling on the drop surface and evaporation rate of sessile drops on solids. The effects of drop cooling, resultant lateral evaporative flux and Marangoni flows on evaporation rate are also discussed. This review also has some special topics such as drop evaporation on superhydrophobic surfaces, determination of the receding contact angle from drop evaporation, substrate thermal conductivity effect on drop evaporation and the rate evaporation of water in liquid marbles. © 2011 Elsevier B.V. All rights reserved.

The effects of evaporation temperature on properties and filtration performances of polysulfone membrane were investigated with a series of experiments. Membranes were fabricated by phase inversion process at five different evaporation temperatures (25 ± 0.4, 35 ± 0.6, 45 ± 0.5, 55 ± 0.5 and 65 ± 0.6 °C). The resulted membranes were characterized by water permeability, MWCO (molecular weight cut-off), AFM, porosity, contact angle and SEM analyses and tested for filtration performances by using a model dye solution (reactive orange 16-RO16) and a real dye-bath textile wastewater. The pore size and density onto the membrane surface become smaller and the surface roughness, porosity, permeability and MWCO values of membranes considerably decreased with the increasing of evaporation temperature. At the pretreatment filtration experiments, the flux values of membranes decreased largely with the increase of the evaporation temperature while the removal efficiencies for color, COD and conductivity parameters increased. At the membrane fouling analysis, the flux reduction ratios (FRR), the filtration (Rt) and fouling (Rf) resistances and the reusable performances of membrane changed directly proportional with roughness, porosity and pore size characteristics of membranes. At the nanofiltration step (NF-270 membrane), the moderate color, chemical oxygen demand (COD) and conductivity removal were showed at permeate of PS-65 membrane (the membrane fabricated at 65 ± 0.6 °C). © 2013 Elsevier B.V.

Bayrakdar H.,Gebze Institute of Technology
Journal of Magnetism and Magnetic Materials | Year: 2011

We have investigated the electromagnetic (EM) characteristics of Co xMn1-xFe2O4 spinel ferrite (where x=0.0, 0.5 and 1.0) nanoparticles (NPs)/paraffin nanocomposite material at 820 GHz. CoxMn1-xFe2O4 NPs have been synthesized by cetyltrimethylammonium assisted hydrothermal route using NaOH. A variation in complex dielectric permittivity and magnetic permeability at room temperature with frequency in the range 820 GHz has been studied. Particles showed phase purity and crystallinity in powder X-ray diffraction (XRD) analysis. At the same time, CoxMn1-xFe2O 4 NPs demonstrated a spinel cubic structure from XRD results. A reflection loss of -46.60 dB was found at 10.5 GHz for an absorber thickness of 2 mm. CoxMn1-xFe2O4 may be attractive candidates for EM wave absorption materials. © 2011 Elsevier B.V.

Melikoglu M.,Gebze Institute of Technology
Renewable and Sustainable Energy Reviews | Year: 2014

Shale gas revolution that took place in the United States at the beginning of the 21st century has still been shaping our global fossil fuel market. In 2012, the U.S. has surpassed Russia in natural gas production for the first time since 1982. At the same year, annual average U.S. Henry hub natural gas spot price decreased to $2.75 per million BTU, which was $8.69 per million BTU in 2005. In 2013, proved shale gas reserves of the world is estimated at nearly 2.7 trillion cubic metres (tcm) and unproved resources at staggering 203.9 tcm. As a result, there is a global rush to develop most of this resource as possible. However, shale gas is no miracle fuel. It has been suggested that its effects on the environment could be worse than conventional natural gas. Fugitive methane emissions, groundwater pollution, and increased seismicity are amongst the most important potential environmental side effects. There is also concern about the accuracy of resource potential estimations due to lack of data and specifically designed shale gas reservoir models. Nonetheless, the analysis in this study clearly showed that without developing global shale gas resources we have to consume 66% of our proved natural gas reserves to supply the demand till 2040. This would make most of the world natural gas importers, and rules of economy dictate that limited supply and increasing demand would skyrocket natural gas prices. Therefore, shale gas resource development is not an option but a must for the continuance of our global energy market and economy. © 2014 Elsevier Ltd.

Kavut S.,Gebze Institute of Technology
Information Sciences | Year: 2012

We give an efficient exhaustive search strategy to enumerate 6 × 6 bijective rotation-symmetric S-boxes (RSSBs) having nonlinearity 24, which is found to be the maximum nonlinearity within the class of 6 × 6 bijective RSSBs. It is shown that there are 3072 RSSBs achieving the cryptographic properties of the inverse function over GF(2 6), i.e., nonlinearity 24, differential uniformity 4, and algebraic degree 5, such that among them there are only four which are not affine-equivalent. Among these four RSSBs, we find a non-affine transformation under which the cryptographic properties of the inverse function are invariant. Then, we define the generalized classes of k-RSSBs as the polynomials of GF(2 n) with coefficients in GF(2 k), where k divides n. Moreover, motivated by the fact that RSSBs are symmetric under a special permutation, we classify all possible permutations up to the linear equivalence of S-boxes that are symmetric under them. © 2012 Elsevier Inc. All rights reserved.

Ozcelik B.,Gebze Institute of Technology
International Communications in Heat and Mass Transfer | Year: 2011

This study optimized effect of injection parameters and weld line on the mechanical properties of polypropylene (PP) moldings. The mold with an insert was designed to create weld line in the experimental specimen. Melt temperature, packing pressure and injection pressure were investigated to study their effects on the mechanical strength of specimens with/without weld lines. Taguchi's L9 (33) orthogonal array design was employed for the experimental plan. Mechanical properties such as maximum tensile load, extension at break and charpy impact strength (notched) of the specimens were measured. Signal to noise ratio for mechanical properties of PP using Taguchi method was calculated and effect of the injection parameters and weld line on mechanical properties was determined using the analysis of variance (ANOVA). Linear models were also created by using regression analysis. The most important parameter affecting the maximum tensile load and the extension at break (for specimen without/with weld line) was injection pressure and melt temperature, and for charpy impact strength (notched) (without/with weld line) was melt temperature and injection pressure, respectively. © 2011 Elsevier Ltd.

Akyol A.,Gebze Institute of Technology
Desalination | Year: 2012

Treatability of paint manufacturing wastewater (PMW) by electrocoagulation (EC) process was investigated. Effects of operating parameters for the EC process such as electrode type (Al or Fe), initial pH (2-10), current density (5-80A/m 2) and operating time (0-50min) were evaluated for optimum operating conditions. The highest removal efficiencies for COD and TOC in PMW were obtained with 93% and 88% for Fe and 94% and 89% for Al electrodes at the optimum conditions (35A/m 2, 15min and pH 6.95). Operating costs for removal of PMW at the optimum conditions were calculated for Fe and Al electrodes as 0.187€/m 3 and 0.129€/m 3. Toxicity test was carried out to obtain information about toxic effect of the raw and treated wastewaters at optimum operating conditions. The samples measured by respirometric method contained hardly toxicities. Performance of Al electrode was better than that of Fe electrode in terms of removal efficiency and operating cost. © 2011 Elsevier B.V.

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