Gerengi H.,Duzce University
Industrial and Engineering Chemistry Research | Year: 2012
The influence of date palm (Phoenix dactylifera L.) (PDL) fruit juice on 7075 type aluminum (AA7075) alloy in 3.5% NaCl solution was investigated by Tafel extrapolarization and electrochemical impedance spectroscopy. It was found that PDL fruit juice acted as a slightly cathodic inhibitor, and inhibition efficiencies increased with the increase of PDL fruit juice concentration. The adsorption of the inhibitor on the metal surface was found to obey the Temkin adsorption isotherm and has a physisorption mechanism. © 2012 American Chemical Society.
Akgul M.,Duzce University
Composites Part B: Engineering | Year: 2013
The main objective of this study was to investigate the possibilities of utilizing stinging nettle (Urtica dioica L.) stalks as a fiber-nettle mixture at various percentages to produce fiberboards for general purposes. Also, we aimed to investigate the possibility of utilizing stinging nettle in panel production, thus helping overcome the raw material shortage that the industry is facing. As wood fiber, pine (Pinus nigra V.), beech (Fagus orientalis L.) and oak (Ouercus robur L.) fiber mixtures (30%, 35% and 35%, respectively) were utilized. In panel production the only variable tested was the addition of nettle stalks at various percentages to the wood fibers. The resultant panels were compared with the panels produced using 100% wood fiber. The results indicated that panels could be produced utilizing nettle stalks up to 40% addition without falling below the properties required in the standards. Higher addition levels diminished the elastic modulus and bending strength below the acceptable level. The observed results indicated that adding nettle stalks to the wood fibers to produce fiberboards at certain percentages would result in panels acceptable to the standards and would be of assistance to the raw material shortage in the Turkish panel industry. © 2012 Elsevier Ltd. All rights reserved.
Gumus M.,Marmara University |
Kasifoglu S.,Duzce University
Biomass and Bioenergy | Year: 2010
In this study, apricot (Prunus armeniaca) seed kernel oil was transesterified with methanol using potassium hydroxide as catalyst to obtain apricot seed kernel oil methyl ester. Neat apricot seed kernel oil methyl ester and its blends with diesel fuel were tested in a compression ignition diesel engine to evaluate performance and emissions. Apricot seed kernel oil methyl ester and its blends can be successfully used in diesel engines without any modification. Lower concentration of apricot seed kernel oil methyl ester in blends gives a better improvement in the engine performance and exhaust emissions. Therefore lower percent of apricot seed kernel oil methyl ester can be used as additive. © 2009 Elsevier Ltd. All rights reserved.
Toklu E.,Duzce University
Renewable Energy | Year: 2013
The necessity of minimizing environmental impacts of energy use, particularly those with potentially worrisome global effects, is perhaps the greatest challenge resulting from the twentieth century's energy advances. The renewable energy technologies of wind, biofuels, solar thermal and photovoltaics are finally showing maturity and the ultimate promise of cost competitiveness. Turkey's demand for energy and electricity is increasing rapidly and heavily dependent on expensive imported fossil energy resources that place a big burden on the economy and environmental pollution is becoming an important concern in the country. With respect to global environmental issues, Turkey's carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. This study shows that there is huge potential for renewable energy in Turkey, especially hydropower, biomass, geothermal, solar and wind. © 2012 Elsevier Ltd.
Samtas G.,Duzce University
International Journal of Advanced Manufacturing Technology | Year: 2014
The traditional devices, used to measure the surface roughness, are very sensitive, and they are obtained by scratching the surface of materials. Therefore, the optic systems are used as alternatives to these devices to avoid the unwanted processes that damage the surface. In this study, face milling process was applied to American Iron and Steel Institute (AISI) 1040 carbon steel and aluminium alloy 5083 materials using the different tools, cutting speeds and depth of cuts. After these processes, surface roughness values were obtained by the surface roughness tester, and the machined surface images were taken using a polarise microscope. The obtained images were converted into binary images, and the images were used as input data to train network using the MATLAB neural network toolbox. For the training networks, log-sigmoid function was selected as transfer function, scaled conjugate gradient (SCG) algorithm was used as training algorithm, and performance of the trained networks was achieved as an average of 99.926 % for aluminium alloy (AA) 5083 aluminium and as an average of 99.932 % for AISI 1040 steel. At the end of the study, a prediction programme for optical surface roughness values using MATLAB m-file and GUI programming was developed. Then, the prediction programme and neural network performance were tested by the trial experiments. After the trial experiments, surface roughness values obtained with stylus technique for the carbon steel and aluminium alloy materials were compared with the developed programme values. When the developed programme values were compared with the experimental results, the results were confirmed each other at a rate of 99.999 %. © Springer-Verlag London 2014.