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: 5Citation - Scopus: 6Development of an Optical Tyrosinase Biosensor (tca) for Detection of “parathion-Methyl”(Emerald Group Publishing Ltd., 2019) Polatoğlu, İlker; Çakıcıoğlu Özkan, FehimePurpose: This paper aims to present a novel and cost-effective optical biosensor design by simple preparation method for detection of “parathion-methyl,” which is a model pesticide pose to public health and the environment. Design/methodology/approach: The optical enzyme biosensor (TCA) for detection of pesticide “parathion-methyl” was developed on the basis of immobilization of tyrosinase enzyme on chitosan film by adsorption technique. The analytic performance of TCA was investigated by measuring its activity with Ultraviolet (UV) visible spectrophotometer. Findings: Uniform porous network structure and protonated groups of chitosan film provided a microenvironment for tyrosinase immobilization evident from Fourier transform infrared (FTIR) spectroscopy and Atomic Force Microscopy analysis. TCA has a wide linear detection range (0-1.03 µM) with high correlation coefficient and it can detect the parathion-methyl concentration as low as 159 nM by noncompetitive inhibition kinetics. Using the TCA sensor both for ten times and at least 45 days without a significant loss in its activity are the indicators of its good operational and storage stability. Moreover, TCA can be applicable to tap water, providing a promising tool for pesticides detection. Originality/value: This is the first time to use the in situ analytical technique that can improve the performance of optical enzyme sensor provided to control the pesticide residue better with respect to traditional techniques. The effect of organic solvents on the performance of optical enzyme biosensor was investigated. Inhibition kinetic of the solvents rarely encountered in literature was also studied besides the pH and temperature tolerance of the optical biosensor.Article Citation - WoS: 15Citation - Scopus: 16A Pore Scale Analysis for Determination of Interfacial Convective Heat Transfer Coefficient for Thin Periodic Porousmedia Undermixed Convection(Emerald Group Publishing Ltd., 2017) Çelik, Hasan; Mobedi, Moghtada; Manca, Oronzio; Özkol, ÜnverPurpose - The purpose of this study is to determine interfacial convective heat transfer coefficient numerically, for a porous media consisting of square blocks in inline arrangement under mixed convection heat transfer. Design/methodology/approach - The continuity, momentum and energy equations are solved in dimensionless form for a representative elementary volume of porous media, numerically. The velocity and temperature fields for different values of porosity, Ri and Re numbers are obtained. The study is performed for the range of Ri number from 0.01 to 10, Re number from 100 to 500 and porosity value from 0.51 to 0.96. Based on the obtained results, the value of the interfacial convective heat transfer coefficient is calculated by using volume average method. Findings - It was found that at low porosities (such as 0.51), the interfacial Nusselt number does not considerably change with Ri and Re numbers. However, for porous media with high Ri number and porosity (such as 10 and 0.51, respectively), secondary flows occur in the middle of the channel between rods improving heat transfer between solid and fluid, considerably. It is shown that the available correlations of interfacial heat transfer coefficient suggested for forced convection can be used for mixed convection for the porous media with low porosity (such as 0.51) or for the flow with low Ri number (such as 0.01). Originality/value - To the best of the authors' knowledge, there is no study on determination of interfacial convective heat transfer coefficient for mixed convection in porous media in literature. The present study might be the first study providing an accurate idea on the range of this important parameter, which will be useful particularly for researchers who study on mixed convection heat transfer in porous media, macroscopically.Article Citation - WoS: 36Citation - Scopus: 46Corporate Social Responsibility in Construction Industry: a Comparative Study Between Uk and Turkey(Emerald Group Publishing Ltd., 2016) Ulutaş Duman, Dilek; Giritli, Heyecan; McDermott, PeterPurpose – Corporate social responsibility (CSR) has evolved to an important agenda for many industries and its scope has been widened from the responsible business to strategic decisions. Therefore, the purpose of this paper is to investigate the concept of CSR from the perspective of construction industry by questioning CSR awareness, CSR activities and CSR integration with a comparative case study between UK and Turkey. Design/methodology/approach – Conducting comparative and qualitative research using a case study methodology, this study sets the context for understanding differences in these two countries as to how CSR is perceived and put into practice by selected case firms. Findings – The results revealed that construction companies are aware of the increasing importance of the CSR; however, company scale and the characteristics of the country have great impact on CSR preferences. Despite the differences in the approaches all firms take with regard to CSR domains and CSR types, ethical domain and the social orientation have become prominent for CSR initiatives in both the UK and Turkey. Originality/value – This study provides the empirical evidence for the understanding and integration of the CSR concept in the construction industry; shed light on missing knowledge about CSR integration and serves as a source for further in-depth researches on CSR.Article Citation - WoS: 11Citation - Scopus: 16Trajectory Planning for a Planar Macro-Micro Manipulator of a Laser-Cutting Machine(Emerald Group Publishing Ltd., 2016) Uzunoğlu, Emre; Dede, Mehmet İsmet Can; Kiper, GökhanPurpose-In the industry, there is always a demand to shorten the task completion durations to maximize the efficiency of the operation. This work focuses on making use of a special type of kinematic redundancy, macro-micro manipulation, to minimize the task completion duration. The purpose of this paper is to develop the most convenient trajectory planner to be integrated with industrial computerized numerical control (CNC) systems to resolve kinematic redundancy for task duration minimization. Design/methodology/approach-A special type of kinematic redundancy is devised by using two kinematically different mechanisms that have different advantages, which are named as macro and micro mechanisms. In this case, the control design including the trajectory planning should be devised taking into account the distinct advantages of both mechanisms. A new trajectory planning algorithm is designed and used for the constructed planar laser-cutting machine, and some benchmark pieces are cut. Findings-Offline method has practical limitations for employment in a real case scenario such as assuming infinite jerk limits for each axis motion. This limitation was removed by using an online trajectory generation technique. Experimental test results indicate that the online trajectory planning technique developed for the macro-micro mechanism to shorten the task duration was successful. Practical implications-Although the new trajectory planning algorithm is implemented for a laser-cutting machine, it can also be used for other manufacturing systems that require higher acceleration and accuracy levels than the conventional machines. The new algorithm is compatible with the commercially available CNC systems. Originality/value-In this work, a new approach to reducing the task duration for planar machining operations was introduced by making use of macro-micro manipulation concept. The core novelty of the work is devising trajectory planning algorithms to get the most efficiency in terms of acceleration limits from a macro-micro manipulation while making these algorithms deployable to most of the CNC systems.Article Citation - WoS: 22Citation - Scopus: 28The Impact of Rail Transit Investment on the Residential Property Values in Developing Countries: The Case of Izmir Subway, Turkey(Emerald Group Publishing Ltd., 2006) Çelik, Hüseyin Murat; Yankaya, UğurPurpose The purpose of this paper is to test whether the rail transit investment in Izmir, Turkey has had positive valuation impacts on the surrounding residential properties, and to estimate the value of travel time using relevant parameters. Design/methodology/approach The necessary data were collected via a survey including all real-estate agents in the area. To test the research question, the Hedonic Price Model (HPM) is used as the research technique. The obtained parameters are also used to estimate the value of travel time. Findings The findings of the models has indicated that the proximity to rail stations was valued at $250-300 per meters, and the value of travel per hour was $1.47-1.83 on average. Research limitations/implications These findings should be checked with more consistent database using transaction process, and the mortgage loan rate which was not legislated at the time of study. Practical implications Until a mortgage loan rate is registered in turkey, the estimated parameters can be used in the cost-benefit analysis of rail transit investments in Turkey. Originality/value The theoretical premise that “any improvement in accessibility will be capitalized into the land values” is tested one more time in a developing country case whose urban environment is substantially different from those of the developed world, especially the North American cities. Furthermore, a new methodology using the HPM parameters is also suggested to estimate the value of travel time.