Authors:Fatime Mine BALCI Abstract: Proton transferin H-bonded molecular systems plays a vital role in many research areas such asbiological, technological and atmospherical. The aim of this study is toinvestigate the dynamics of proton transfer along the methanol wires byaddition of NH3 or H2O to the methanol ring at lowtemperatures. On-the-fly molecular dynamics as implemented in the densityfunctional code QUICKSTEP which is part of CP2K package were used in thisstudy. In NH3 containing methanol clusters, the proton is localizedon NH3. On the other hand, the proton is delocalized along themethanol wires containing water molecule. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Kamran Samet; Oğuz Yılmaz, Harun Koçak, Asghar Safarian, Çetin Karataş Abstract: Powderinjection molding (PIM) is a method thatis emerged from the combination of conventional powder metallurgy technique andplastic injection molding. This method, comprises four basic steps including ofpreparation of the feedstock, injecting into the mold,the binder removalprocess and sintering. The binder removal process in PIM effects the ultimatestrength achieved in part after sintering. Also if the debinding time is selectedas higher than optimum level, production cost will increase, obviously. Therefore,determination of loss of mass that occurs during binder removal process issignificant. In this study, tungsten carbide (WC) samples with three differentdiameters (4,3; 9,75 ve 12 mm) and threedifferent lengths (15, 14, ve 11 mm) were produced by PIM method. Then thesesamples were subjected to chemical debinding process at four different time,24, 48, 60 and 72 hours, respectively.Ethanol was used as solvent in the chemical binder removal process, As a resultof experiments, the effects of sample thickness, volume, surface area/volumeratio (Ay / V) and debinding time on weight loss were specified byusing PIM. According to the this study, as the surface area/volume ratio (Ay/ V) is increased the weight loss will increased, while the thickness and volume are increased, weightloss will decreased for the green part of the feedstock. 60 hours is determinedas optimum binder removal parameters for the case of 60°C in ethanol. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Demet AYDIN Abstract: In this study, we introduce the five-parameterdoubly-truncated exponentiated inverse Weibull distribution, where thetruncation points are known, and consider its basic properties. Formulas formoment generating function, characteristic function, mean, variance andkurtosis of the distribution are derived. Estimates of parameters are obtainedusing traditional estimation methods; maximum likelihood, least squares andweighted least squares. Furthermore, in order to give a lower bound for thestandard errors of estimates of parameters, a Fisher information matrix is provided.Finally, a Monte-Carlo simulation study is designed and conducted to evaluatethe performances of obtained estimators of parameters. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Aysun Özkan; Ece Yapıcı, Zerrin Günkaya, Müfide Banar Abstract: Plastics are heavily used in every field of dailylife and industrial production. Most of the plastics used to meet therequirements are converted to waste in a short time, so the amount of plasticwaste is considerably high. Alternative methods of converting these waste intoproduct should be investigated and applied in order to reduce the environmentaland health hazards of some recycled, burned or stored plastics in the currentsituation. From this point of view, this study deals with the use of plasticwaste in the production of carbon nanotube (CNT), a valuable material. Presentdata and application areas related to plastic wastes were evaluated, briefinformation about CNT production was given and the use of plastic types ascarbon source in this process was examined. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Bahar KARAMAN; Yılmaz DERELİ Abstract: Inthe present study, the meshless method based on radial basis functions isapplied for finding the numerical solution of the general Rosenau KdV-RLWequation. Firstly, Crank-Nicolson and forward finite difference methods areused for discretization of the unknown function and its time derivative,respectively. A linearization technique is applied for the approximate solutionof the equation. Secondly, we calculate the numerical values of invariants ofthe motions to examine the fundamental conservative properties of the equation.Also, the error norms are computed to determine the accuracy of the proposedmethod. Linear stability analysis is tested to determine whether the presentmethod is stable or unstable. The scheme gives unconditionally stable. At theend of this paper, obtained results indicate the accuracy and applicability ofthis method. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Edip AVŞAR; İsmail TORÖZ Abstract: Allsurface and ground waters include natural organic matter (NOM). During thedisinfection NOM reacts with chlorine and forms various types of halogenateddisinfection by-products (DBPs). There are lots of study in the literatureabout these possible carcinogenic effects on human. Trihalomethanes (THMs) andhaloacetic acids (HAAs) are the most widely known and most produced DBPs. Butthere lots of different types of DBPs occurred after the disinfection andsometimes absorbable organic halogens (AOX) measurement can be used fordetermining the total amount of DBPs. In this study raw water samples weretaken from Büyükçekmece (BC) and Ömerli (OM) surface water sources in theseasonal basis. At the first stage water quality parameters were analysed andthen samples were chlorinated. After 7 days reaction period THMs, HAAs,haloasetonitrilles (HANs), chloral hydrate (CH), chloropicrin (CP) and AOXmeasurements were conducted and according to these results undefined DBPspercentage of AOX was calculated. In terms of OM and BC raw water undefinedportion of AOX was averagely calculated as 59.4% and 58% respectively. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Aysun Özkan; Zerrin Günkaya, Alp Özdemir, Müfide Banar Abstract: Günümüzde sanayi dünyası, tekil endüstri mantığındanuzaklaşarak birbiriyle daha çok iletişim halinde olan çoğul endüstriyaklaşımına doğru hızla ilerlemektedir. Bu durum, işletmeler arasındakietkileşimin sadece hammadde veya ürün kullanımından ibaret olmadığını, aynızamanda yan ürün ve diğer birçok atık çeşidinin de birer hammadde olabileceğinigöstermektedir. Son yıllarda, hızlıendüstrileşme ile birlikte meydana gelen bu yönelim, öncelikle boru sonuyaklaşımın terkedilmesi ve kirlilik önleme mantığının geliştirilmesiadımlarıyla güçlendirilmiştir. Bu çalışmada, temiz üretim anlayışının sonzamanlarda artan bir gelişim gösteren araçlarından birisi olan endüstriyel simbiyozyaklaşımı irdelenmiş ve bu yaklaşımın temel prensipleri üzerinde durulmuş, Dünyave Türkiye’deki endüstrilerde gerçekleştirilmiş uygulamalar hakkında birdeğerlendirme yapılmıştır. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Sezer SORGUN; Hatice TOPCU Abstract: The kite graph is denoted by Kiten,n-pwhich is obtained by appending a complete graph Kp to a pendantvertex of the path graph Pn-p . In this paper, we present somespectral properties of Laplacian matrix of the kite graph. First we give theLaplacian characteristic polynomial of Kiten,n-p , then we restrictits largest Laplacian eigenvalue depending on the clique number. Also we saythat any connected graph which has the same clique number with Kiten,n-pis isomorphic to the Kiten,n-p under some conditions. PubDate: Mon, 30 Apr 2018 00:00:00 +030

Authors:Abdullah Engin ÇALIK; Hüseyin ŞİRİN Abstract: In this study, inconsistency between experimental and theoreticalhalf-value thickness for the absoption of gamma rays in concrete materials withdifferent chemical properties has been removed with the help of fractionalcalculus. The first order differential equation related to the absorption hasbeen re-defined by using Caputo fractional derivative. The solution of this equationhas been obtained in terms of Mittag-Leffler function. The fractionalcalculations have been done using experimental and theoretical attenuationcoefficients data obtained from gamma ray sources 241Am and 137Cs with59.9 keV and 661 keV, respectively. The obtained results have beeen comparedwith the experimental and standard ones. How the calculated fractionalderivative orders affect the intensity of the gamma ray as it passes throughthe absorbent material has been attempted to determine. PubDate: Sat, 21 Apr 2018 00:00:00 +030