Time filter

Source Type

Ankara, Turkey

The Turkish Academy of science is an autonomous scholarly society acting to promote scientific activities in Turkey. Although it is attached to the office of the Prime Minister and is largely funded by the government, it maintains financial and administrative autonomy. The academy is headquartered in Ankara.In addition to conferring awards and fellowships to distinguished scientists, the academy is also responsible with determining scientific priority areas and proposing policies and needed changes in legislation to the government. The implementation and management of actual research programmes is carried out by The Scientific and Technological Research Council of Turkey .Traditionally, the academy elected its own members, but beginning in November 2011, the Turkish government under the leadership of Recep Tayyip Erdoğan announced that it would take over new appointments, and appointed 100 new members. Accordingly, over 60 of the existing old members of the academy got resigned. Its current president is Ahmet Cevat ACAR who is prestigious professor in business academics and the former vice rector of the Istanbul University. Wikipedia.

Hocaoglu S.M.,TUBITAK - Marmara Research Center | Insel G.,Technical University of Istanbul | Cokgor E.U.,Technical University of Istanbul | Orhon D.,Technical University of Istanbul | Orhon D.,Turkish Academy Of Sciences
Bioresource Technology | Year: 2011

Effect of low dissolved oxygen on simultaneous nitrification and denitrification was evaluated in a membrane bioreactor treating black water. A fully aerobic membrane bioreactor was operated at a sludge age of 60. days under three low dissolved oxygen (DO) levels below 0.5. mg/L. It sustained effective simultaneous nitrification/denitrification for the entire observation period. Nitrification was incomplete due to adverse effects of a number of factors such as low DO level, SMPs inhibition, alkalinity limitation, etc. DO impact was more significant on denitrification: Nitrate was fully removed at low DO level but the removal was gradually reduced as DO was increased to 0.5. mg/L. Nitrogen removal remained optimal within the DO range of 0.15-0.35. mg/L. Experimental results were calibrated and simulated by model evaluation with the same model coefficients. The model defined improved mass transfer with lower affinity coefficients for oxygen and nitrate as compared to conventional activated sludge. © 2010 Elsevier Ltd.

Hocaoglu S.M.,TUBITAK - Marmara Research Center | Insel G.,Technical University of Istanbul | Ubay Cokgor E.,Technical University of Istanbul | Orhon D.,Technical University of Istanbul | Orhon D.,Turkish Academy Of Sciences
Bioresource Technology | Year: 2011

This study evaluated the effect of sludge age on simultaneous nitrification and denitrification in a membrane bioreactor treating black water. A membrane bioreactor with no separate anoxic volume was operated at a sludge age of 20. days under low dissolved oxygen concentration of 0.1-0.2. mg/L. Its performance was compared with the period when the sludge age was adjusted to 60. days. Floc size distribution, apparent viscosity, and nitrogen removal differed significantly, together with different biomass concentrations: nitrification was reduced to 40% while denitrification was almost complete. Modelling indicated that both nitrification and denitrification kinetics varied as a function of the sludge age. Calibrated values of half saturation coefficients were reduced when the sludge age was lowered to 20. days. Model simulation confirmed the validity of variable process kinetics for nitrogen removal, specifically set by the selected sludge age. © 2011 Elsevier Ltd.

This study investigates the low velocity impact properties such as damage thresholds, critical energy thresholds and damage process of laminated composites. Damage thresholds of Hertzian failure and main failure corresponding to woven and unidirectional Glass Fiber Reinforced Polymer laminates in varying thicknesses from 2. mm to 8. mm are determined through impact tests with nominal impact energies of 4, 6, and 8. J/layer. Hertzian failure and main failure thresholds of a composite laminate with a particular thickness remain substantially constant with the nominal and incipient impact energies. Energy profile and normalized energy profile diagrams are used to find out the penetration and perforation thresholds as well as explaining the correlation between the threshold energies and damage process of the laminates. Dissipated energy by a laminate is determined using a second order polynomial regression based on the relationship between energy dissipation and impact energy of data points before penetration. Penetration and perforation energies increase non-linearly with the thickness and thickness dependence is expressed using a power regression. Test results related to damage thresholds, threshold energies and effective damage area reveal that unidirectional laminates possess lower impact damage resistance and hence are more sensitive to impact damage. © 2015 Elsevier Ltd.

Aplak H.S.,Turkish Academy Of Sciences | Sogut M.Z.,Turkish Military Academy
Energy Conversion and Management | Year: 2013

Intensive energy consuming industrial sectors are the most important actors on global climate change which natural habitat and the environment faced. In this study, by the scope of energy management, decision-making process of the industry and the environment are evaluated in a game theoretic approach. Industry and environment are considered as two players which have conflicting objectives and try to find optimal strategies in governing energy policy. According to concept of study, while industry tries to maintain the sustainability of production with the strategies of fossil fuel, renewable energies, energy recovery and nuclear energy usage, environment exhibits reactive approach to ensure its sustainability. In the flow of study, players' strategies are analyzed by using Multi-Criteria Decision Making (MCDM) methods and by calculating performance efficiency values of strategies, game payoff matrix is obtained. Finally, optimal strategies are found for both industry and environment in orienting their energy policy and results are evaluated. According to results of the payoff matrix, the equilibrium point is the cell (2, 1) with the values of 0.5324 and 0.5619. This implies that the environment develops protective reflexes for sustainable nature in case of using renewable energy in industry. © 2013 Elsevier Ltd. All rights reserved.

Eryilmaz S.,Atilim University | Sarikaya K.,Turkish Academy Of Sciences
Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability | Year: 2014

This article is concerned with the reliability analysis of a weighted-k-out-of-n:G system consisting of two types of components. The system is assumed to have n components which are classified into two groups with respect to their weight and reliability, and it is assumed to operate if the total weight of all working components exceeds a prespecified threshold k. The reliability properties of such a system are studied. The optimal values of the number of components in each group are also determined under a minimum required reliability by minimizing the total acquisition cost. © IMechE 2013.

Discover hidden collaborations