Showing papers by "Istanbul Technical University published in 2008"
Potsdam Institute for Climate Impact Research1, Central University of Venezuela2, University of Reading3, Goethe University Frankfurt4, National Autonomous University of Mexico5, National Center for Atmospheric Research6, University of Tokyo7, Istanbul Technical University8, State Hydrological Institute9
TL;DR: The implications of projected climate change for freshwater resources and their management are discussed in this article, where the authors present an analysis of the potential impacts of climate change on freshwater resources in terms of their management.
Abstract: (2008). The implications of projected climate change for freshwater resources and their management. Hydrological Sciences Journal: Vol. 53, No. 1, pp. 3-10.
782 citations
TL;DR: A multifaceted approach has revealed that each processing step induces specific alterations in the metabolic profile, as determined by the different analysis procedures, and that in particular the fruit-breaking step and the removal of seed and skin significantly affect the levels of antioxidants and many other metabolites present in commercial tomato paste.
Abstract: Tomato products and especially concentrated tomato paste are important sources of antioxidants in the Mediterranean diet. Tomato fruit contain well-known antioxidants such as vitamin C, carotenoids, flavonoids, and hydroxycinnamic acids. The industrial processing of this fruit into tomato paste involves several treatments that potentially affect the final profile of antioxidants and other metabolites in the commercial product. Here we have used both biochemical and metabolomic techniques to assess the effect of each separate step in the industrial production chain starting from fresh fruit to the final tomato paste. Material was collected from five independent tomato paste production events spread over two successive years. Samples comprised the intact ripe fruits and semifinished products after fruit-breaking, separation of the pulp from skin and seeds, evaporation, and finally after canning and pasteurization. The effect of each processing step was determined by different types of analysis. First, the total antioxidant capacity and total phenolic content were determined by commonly used spectrophotometric methods. Second, individual antioxidants in the extracts were identified and compared using an HPLC with online antioxidant detection. Third, in each sample the levels of the major individual antioxidants present, i.e., vitamin C, phenolic compounds (such as rutin and chlorogenic acid), tocopherols, and carotenoids, were quantified. Fourth, an untargeted metabolomic approach using LC-QTOF-MS was used to identify those production steps that have the largest impact on the overall metabolic profile in the final paste as compared to the original fruits. This multifaceted approach has revealed that each processing step induces specific alterations in the metabolic profile, as determined by the different analysis procedures, and that in particular the fruit-breaking step and the removal of seed and skin significantly affect the levels of antioxidants and many other metabolites present in commercial tomato paste.
286 citations
TL;DR: In this paper, a study was conducted to fibrillate cellulose from micro to nano scale and evaluate how these microfibers and nanofibrils affected the mechanical and thermal properties of thermoplastic polyurethane.
278 citations
TL;DR: It is proposed that there are two modes by which microtubule severing is orchestrated during axonal branch formation, one based on the local concentration of spastin at branch sites and the other based on local detachment from microtubules of molecules such as tau that regulate the severing properties of P60-katanin.
Abstract: Neurons express two different microtubule-severing proteins, namely P60-katanin and spastin. Here, we performed studies on cultured neurons to ascertain whether these two proteins participate differently in axonal branch formation. P60-katanin is more highly expressed in the neuron, but spastin is more concentrated at sites of branch formation. Overexpression of spastin dramatically enhances the formation of branches, whereas overexpression of P60-katanin does not. The excess spastin results in large numbers of short microtubules, whereas the excess P60-katanin results in short microtubules intermingled with longer microtubules. We hypothesized that these different microtubule-severing patterns may be due to the presence of molecules such as tau on the microtubules that more strongly shield them from being severed by P60-katanin than by spastin. Consistent with this hypothesis, we found that axons depleted of tau show a greater propensity to branch, and that this is true whether or not the axons are also depleted of spastin. We propose that there are two modes by which microtubule severing is orchestrated during axonal branch formation, one based on the local concentration of spastin at branch sites and the other based on local detachment from microtubules of molecules such as tau that regulate the severing properties of P60-katanin.
252 citations
TL;DR: In this paper, a direct generation of electricity from monosaccharides of lignocellulosic biomass was examined using air cathode microbial fuel cells (MFCs).
241 citations
TL;DR: In this article, three types of paraffin waxes suitable for textile applications were encapsulated through complex coacervation of natural and biodegradable polymers, gum arabic-gelatin mixture, in order to investigate their heat storing or releasing capacities, their durability as well as their practicable thermal performances when integrated into woven fabrics by coating.
239 citations
TL;DR: In this paper, the removal of several hormones and antibiotics by nanofiltration membranes was studied in mixed solutions and the effects of solution chemistry, organic matter and salinity were investigated on the rejection of tetracycline's and sulfanamides and selected hormones and their adsorption on membranes.
239 citations
13 Apr 2008
TL;DR: A novel physically-inspired mobility model which is representative of underwater environments is proposed and how the model affects a range-based localization protocol, and its impact on the coverage and connectivity of the network under different deployment scenarios is studied.
Abstract: Underwater mobile acoustic sensor networks are promising tools for the exploration of the oceans. These networks require new robust solutions for fundamental issues such as: localization service for data tagging and networking protocols for communication. All these tasks are closely related with connectivity, coverage and deployment of the network. A realistic mobility model that can capture the physical movement of the sensor nodes with ocean currents gives better understanding on the above problems. In this paper, we propose a novel physically-inspired mobility model which is representative of underwater environments. We study how the model affects a range-based localization protocol, and its impact on the coverage and connectivity of the network under different deployment scenarios.
210 citations
TL;DR: The effects of constraints imposed on FliTrx-selected gold-binding peptide molecular structures upon their quantitative gold- binding affinity are discussed.
Abstract: Despite extensive recent reports on combinatorially selected inorganic-binding peptides and their bionanotechnological utility as synthesizers and molecular linkers, there is still only limited knowledge about the molecular mechanisms of peptide binding to solid surfaces. There is, therefore, much work that needs to be carried out in terms of both the fundamentals of solid-binding kinetics of peptides and the effects of peptide primary and secondary structures on their recognition and binding to solid materials. Here we discuss the effects of constraints imposed on FliTrx-selected gold-binding peptide molecular structures upon their quantitative gold-binding affinity. We first selected two novel gold-binding peptide (AuBP) sequences using a FliTrx random peptide display library. These were, then, synthesized in two different forms: cyclic (c), reproducing the original FliTrx gold-binding sequence as displayed on bacterial cells, and linear (l) dodecapeptide gold-binding sequences. All four gold-binding pe...
204 citations
TL;DR: Evidence is provided that the Ca/P ratio of calcium phosphate is a very important factor that should be considered when selecting nano-to-micron particulate calcium phosphates for various orthopedic applications.
202 citations
TL;DR: In this paper, a combined wavelet-ANN method was proposed to estimate and predict the suspended sediment load in rivers by using measured data were decomposed into wavelet components via discrete wavelet transform, and the new wavelet series was used as input for the ANN model.
TL;DR: In this paper, the authors investigated the pre-treatment alternatives of reverse osmosis and nanofiltration membranes and found the most appropriate treatment combination for the produced water generated from oil production fields in Trakya region.
TL;DR: In this article, the interaction between different conditions, control strategies and heating/cooling loads in office buildings in the four major climatic zones in Turkey was evaluated through building energy simulation program.
TL;DR: In this paper, high molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized, which preserve shape and toughness after thermal curing between 140 and 220 °C.
Abstract: High molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich reaction of 4,4′-isopropylidenediphenol (bisphenol A), formaldehyde, and 2-(2-aminoethoxy)ethanol. Polycondensation of the resulting benzoxazine dietherdiol with adipoyl chloride and terephthaloyl dichloride in the presence of triethyl amine yields the corresponding PEE with the molecular weights of 34.000 Da. The structures of the precursor diol monomer and the resulting PEEs are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H-NMR) analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry (DSC). Flexible free standing transparent films of the PEEs are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 140 and 220 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 414–420, 2008
TL;DR: A novel Extended-Kalman-Filter (EKF)-based estimation technique is developed for the solution of the problem based on the consecutive operation of two EKF algorithms at every time step, demonstrating a significantly increased accuracy in the estimation of Rs and R'r, as well as load torque, flux, and velocity in transient and steady state, when compared with single EKFs.
Abstract: Temperature- and frequency-dependent variations of the rotor (R'r) and stator (Rs) resistances pose a challenge in the accurate estimation of flux and velocity in the sensorless control of induction motors (IMs) over a wide speed range. Solutions have been sought to the problem by signal injection and/or by the use of different algorithms for the different parameters and states of the same motor. In this paper, a novel Extended-Kalman-Filter (EKF)-based estimation technique is developed for the solution of the problem based on the consecutive operation of two EKF algorithms at every time step. The proposed ldquobraidedrdquo EKF technique is experimentally tested under challenging parameter and load variations in a wide speed range, including low speed. The results demonstrate a significantly increased accuracy in the estimation of Rs and R'r, as well as load torque, flux, and velocity in transient and steady state, when compared with single EKFs or other approaches taken to estimate these parameters and states in the sensorless control of IMs. The improved results also motivate the utilization of the new estimation approach in combination with a variety of control methods which depend on accurate knowledge of a high number of parameters and states.
TL;DR: A novel integration of neural networks (NN) and data envelopment analysis for evaluation of suppliers under incomplete information of evaluation criteria is explored.
Abstract: Supplier evaluation and selection are critical decision making processes that require consideration of a variety of attributes. Several studies have been performed for effective evaluation and selection of suppliers by utilizing several techniques such as linear weighting methods, mathematical programming models, statistical methods and AI based techniques. One of the successful evaluation methods proposed for this purpose is data envelopment analysis (DEA), that utilizes techniques of mathematical programming to evaluate the performance of a set of homogeneous decision making units, when multiple inputs and outputs need to be considered. It is often complicated, costly and sometimes impossible to acquire all necessary information from all potential suppliers to attain a reasonable set of similar input and output values which is an essential for DEA. The purpose of this study is to explore a novel integration of neural networks (NN) and data envelopment analysis for evaluation of suppliers under incomplete information of evaluation criteria.
TL;DR: This study examines how young consumers perceive Internet banking in relation to other six banking channels and shows that Internet banking is considered to be efficient for ease of use and access and that the users of Internet banking lack confidence in the security of the web sites of Internet Banking.
TL;DR: In this study, differential transform method (DTM) is applied to both integro-differential and integral equation systems and further expanded with a formulation to treat Fredholm integrals to show capability and robustness.
Abstract: In this study, differential transform method (DTM) is applied to both integro-differential and integral equation systems. The method is further expanded with a formulation to treat Fredholm integrals. If the system considered has a solution in terms of the series expansion of known functions, this powerful method catches the exact solution. So as to show this capability and robustness, some systems of integral and integro-differential equations are solved as numerical examples.
TL;DR: In this article, the authors investigate comparative tribological behaviors of Cu-doped TiN, CrN, and MoN coatings under a wide range of dry sliding conditions.
TL;DR: The hybrid UASB reactor could be a suitable alternative for the treatment of chemical synthesis-based pharmaceutical wastewater and the maximum loading capacity achievable before reactor failure was determined.
TL;DR: Ant colony optimization (ACO) algorithm is proposed to solve flow shop scheduling problem with multi-objectives of makespan, total flow time and total machine idle time and computational results show that proposed algorithm is more effective and better than other methods compared.
TL;DR: In this article, the authors examined the effects of alternative developmental and reward-based antecedents and affective and behavioral consequences of frontline service employee commitment to service quality, and also evaluated the moderating effect of manager commitment on service quality relative to service commitment.
Abstract: Research that examines approaches for improving frontline service employee commitment to service quality is relatively scarce, especially in business-to-business contexts. Using a sample of 310 frontline service employees from the logistics service provider industry, we examine the effects of alternative developmental and reward-based antecedents and affective and behavioral consequences of frontline service employee commitment to service quality. We also evaluate the moderating effect of manager commitment to service quality relative to frontline service employee commitment to service quality. Our findings indicate that managerial coaching has the strongest influence on frontline service employee commitment to service quality. The results also show that frontline service employee commitment to service quality improves job-related outcomes. In addition, manager commitment to service quality relative to frontline service employee commitment to service quality has a moderating influence on the proposed fron...
TL;DR: The Middle Eocene volcano-sedimentary units of Northern Anatolia are confined into a narrow zone trending parallel to the Intra Pontide and Izmir-Ankara-Erzincan sutures, along which the northern branch of the Neotethys Ocean was closed during a period between Late Maastrichtian and Paleocene.
TL;DR: A model was established to predict specific energy requirement of constant cross-section disc cutters in the rock cutting process by using fuzzy logic method based on experience and the database which consists of linear cutting test results that were generated over for many years at the Earth Mechanics Institute of the Colorado School of Mines.
TL;DR: In this paper, the effect of Fenton-treated acid dyes (C.I. Acid Red 183 and C. I. Reactive Blue 4) on aerobic, anoxic and anaerobic processes was investigated.
TL;DR: In this article, the cationic polymerization of cyclohexene oxide (CHO) was achieved by UV irradiation (λ = 350−420 nm) of methylene chloride solutions containing benzoyltrimethylgermane (BTG) and onium salts, such as onium salt.
Abstract: The cationic polymerization of cyclohexene oxide (CHO) was achieved by UV irradiation (λ = 350−420 nm) of methylene chloride solutions containing benzoyltrimethylgermane (BTG) and onium salts, such...
TL;DR: In this paper, geometrical, functional and material properties of the building stock in the northern Marmara Region, particularly around Istanbul, have been investigated and evaluated for use in loss estimation models and other types of statistic- or probability-based studies.
TL;DR: In this paper, the authors provide new isotopic data from the Pontides, which substantiate the presence of a Cadomian basement with latest Proterozoic granitoids but also show the existence of Ordovician intrusives.
TL;DR: In this article, the authors proposed that market orientation and certain employee development practices (service-related training, coaching, and empowerment) influence both employee and organizational performance, and tested these hypotheses using data from 123 large logistics service provider organizations.
TL;DR: Toxicity characteristic leaching procedure (TCLP) results indicated that the produced samples could be taken as non-hazardous materials and Microstructural, physical, chemical and mechanical properties of the produced glass-ceramic samples are better than those of theproduced glass and ceramic samples.