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Conference Object Citation - WoS: 5Citation - Scopus: 3Evaluation of Efficiencies of Diffuse Allochthonous and Autochthonous Nutrient Input Control in Restoration of a Highly Eutrophic Lake(I W A Publishing, 2002) Muhammetoglu, A; Muhammetoglu, H; Soyupak, SMogan Lake is an important recreational area for Metropolitan Ankara-Turkey. It is a shallow eutrophic lake with a dense growth of macrophytes. The main contributors of nutrients and other pollutants to the lake are the creeks carrying the runoff water from the watershed and upland farming land, in addition to the domestic and industrial wastewater discharges from a nearby town and industries. Hydrodynamic and water quality modeling techniques were used to determine the optimum management schemes for the lake restoration and diffuse pollution control. Management scenarios were devised and tested to control allochthonous and autochthonous nutrient inputs to the lake. Phosphorus and nitrogen load reductions were the main test elements for the control of allochthonous nutrient inputs. The scenario analysis revealed that reduction of phosphorus and nitrogen loads from diffused sources will have a marginal effect on controlling eutrophication if macrophyte growth is left uncontrolled. Scenarios employing macrophyte harvesting and sediment dredging have been evaluated for autochthonous nutrient input control. Sediment dredging alone has been shown to yield the most favorable conditions for water quality improvement in Mogan Lake. Further, control of diffuse pollution was an essential final step to achieve an acceptable long-term sustainable water quality improvement in the lake.Article Citation - WoS: 7Citation - Scopus: 10Efficient Software Review Process for Small and Medium Enterprises(inst Engineering Technology-iet, 2007) Mishra, D.; Mishra, A.A considerable amount of software is produced world-wide by small and medium enterprises (SMEs). These organisations do not have enough resources to implement a rigorous quality plan. It has been established that reviews of various artifacts play a very important role in ensuring the quality of software. Traditional review methods are rigorous and their implementation is cumbersome for SMEs. A new review process which is easy to implement and requires almost no documentation is introduced. It is based on reviewers' efforts to produce high-quality software while minimising the inspection cost. Additionally, people who are conducting this review need not be present at the same place during most phases of the review process. This process has been successfully implemented in a CMM level 3 software development company intending to achieve CMMI level 5 and results are found to be quite encouraging.Article Citation - WoS: 14Citation - Scopus: 14Fuzzy Logic Model To Estimate Seasonal Pseudo Steady State Chlorophyll-A Concentrations in Reservoirs(Springer, 2004) Soyupak, S; Chen, DGA fuzzy logic model is developed to estimate pseudo steady state chlorophyll-a concentrations in a very large and deep dam reservoir, namely Keban Dam Reservoir, which is also highly spatial and temporal variable. The estimation power of the developed fuzzy logic model was tested by comparing its performance with that from the classical multiple regression model. The data include chlorophyll-a concentrations in Keban lake as a response variable, as well as several water quality variables such as PO4 phosphorus, NO3 nitrogen, alkalinity, suspended solids concentration, pH, water temperature, electrical conductivity, dissolved oxygen concentration and Secchi depth as independent environmental variables. Because of the complex nature of the studied water body, as well as non-significant functional relationships among the water quality variables to the chlorophyll-a concentration, an initial analysis is conducted to select the most important variables that can be used in estimating the chlorophyll-a concentrations within the studied water body. Following the outcomes from this initial analysis, the fuzzy logic model is developed to estimate the chlorophyll-a concentrations and the advantages of this new model is demonstrated in model fitting over the traditional multiple regression method.Article Citation - WoS: 10Citation - Scopus: 10Electroinitiated Polymerization of 2-Allylphenol(Springer-verlag, 2000) Cihaner, A; Önal, AMRedox behaviour of 2-allylphenol (2APhOH) was studied by using cyclic voltammetry (CV) and electroinitiated polymerization was conducted at the measured peak potentials. Constant potential electrolysis (CPE) of the monomer was carried out in acetonitrile-sodium perchlorate, solvent-electrolyte couple, at room temperature. Polymerization of the monomer yielded insoluble polymer films on the surface of the electrode together with the low molecular weight polymers in the bulk of the solution. The structural analysis of the polymers were carried by H-1-NMR and FTIR spectroscopy. Molecular weight of the soluble polymer was determined by GPC. Thermal properties of the polymer film and soluble polymer were studied by DSC. The course of electroinitiated polymerization was monitored by in-situ UV-VIS spectroscopy.Conference Object Citation - WoS: 1The Generalized Divergence Theorem and Its Application To Harmonic Maps(Pergamon-elsevier Science Ltd, 2001) García-Río, E; Kupeli, DNA survey of divergence theorems in semi-Riemannian geometry is made. The generalization of a divergence theorem to vector fields along a map is given in semi-Riemannian geometry and an application of it is made in Riemannian geometry to obtain some sufficient conditions for a map to be harmonic.Article Citation - WoS: 1Citation - Scopus: 1Spectroelectrochemical Investigation of the Anodic Oxidation of Dibenzo-18(Elsevier Science Sa, 2004) Cihaner, A; Önal, AMPoly(dibenzo-18-crown-6) (poly-DB18C6) was synthesized by electrochemical oxidation of dibenzo-18-crown-6 (DB18C6) using a mixture of acetonitrile and dichloromethane as the solvent and tetrabutylammonium tetrafluoroborate (TBABF(4)) or tetrabutylammonium hexafluorophosphate (TBAPF(6)) as supporting electrolyte. The anodic polymerization of DB18C6 was investigated using in situ ESR and in situ UV-Vis spectroscopic techniques. Spectroelectrochemical (SPEL), properties and thermal analysis of the resulting polymers have been investigated using UV-Vis spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). (C) 2004 Elsevier B.V. All rights reserved.Publication China-Africa Relations in the 21st Century : Engagement,compromise and Controversy(2009) Uchehara, E.kieranÇin’in Afrika ile ilgili dış politika gündemi, gelişmekte olan ülkeler arasındaki işbirliğini artırma ve yükselen bir süper güç olarak statüsünü gösterme hamlesinin bir parçasını oluşturmaktadır. 2000 Pekin Deklarasyonu ve Çin-Afrika Ekonomik ve Siyasi işbirliği Programı yenilenen ilişkilerin temelini oluşturmaktadır. Çin, Afrika ile tüm karşılıklı ilişki alanlarında Afrika ile farklı ve çeşitli ilişkiler geliştirmiştir. Ancak Çin’in büyüyen sanayisinin ihtiyaç duyduğu Afrika’nın maden ve enerji kaynakları, 21. yüzyılda Çin’in Afrika ile iyi ilişkiler kurmasının ana sebebidir. Çin’in Afrika’daki ticaret ve yatırımındaki hızlı artış, kıtanın kalkınması ile ilgili fırsatlar ve zorlukların yapısına ilişkin ve Batı ile olduğu gibi yeni-sömürgeci tarzı ilişkilerin gelişme ihtimalinin olup olmadığı konusunda akademisyenler ve siyasiler arasındaki uyuşmazlıkları açığa çıkarmıştır. Kısmen ekonomik asimetrilerden kaynaklanan ticari ve yatırım ilişkilerindeki dengesizlik, Çin’in Afrikalı baskıcı yönetimleri kınamaması ve iyi yönetilmeyen ekonomiler; kendisine hizmet eden ve kısa dönem kazanımlardan etkilenen bir dış ekonomik politikayı işaret etmektedir.Article Citation - WoS: 47Citation - Scopus: 68On the Positive Solutions of the System of Rational Difference Equations(Academic Press inc Elsevier Science, 2006) Ozban, Ahmet YasarOur aim in this paper is to investigate the periodic nature of solutions of the system of rational difference equations x(n+1) = 1/y(n-k), y(n+1) = yn/x(n-mYn-m-k), n = 0, 1,..., where k is a nonnegative integer, m is a positive integer and the initial values x(-m), x(-m+1),..., x(0), y(-m-k), y(-m-k+1),..., y(0) are positive real numbers. (c) 2005 Elsevier Inc. All rights reserved.Article Citation - WoS: 28Citation - Scopus: 30A Piezoelectric Micromotor With a Stator of φ=1.6 Mm and l=4 Mm Using Bulk Pzt(inst Pure Applied Physics, 2004) Cagatay, S; Koc, B; Moses, P; Uchino, KThe smallest discrete piezoelectric ultrasonic motor using bulk ceramics was developed. We are proposing basically a two-part motor: stator and rotor. The stator of the present motor consists of a hollow metal brass tube with outer diameter of 1.6 mm, inner diameter of 0.8 mm and length of only 4 mm with 2 PZT plates bonded onto it. Owing to the asymmetrical stator surface, two degenerated orthogonal bending modes were slightly split, resulting in a wobbling motion. Thus, the motor can be driven by a single driving source. The rotor is a spring, which is basically different from previous designs, pressed at both ends to the stator by a pair of ferrules. Consequently, the length of the whole motor assembly was reduced significantly; a final motor length cf only 5 mm was obtained. The working frequency under zero load was approximately 227-233 kHz. Although the size is small, relatively high power was obtained under an optimized load condition: torque of 0.06mNm, maximum power of 3.2 mW with a speed of 118 rad/s, and maximum efficiency of 11% under 48 Vrms at 221 kHz.Article Citation - WoS: 21Citation - Scopus: 21Special Standard Static Space-Times(Pergamon-elsevier Science Ltd, 2004) Dobarro, F; Ünal, BEssentially, some conditions for the Riemannian factor and the warping function of a standard static space-time are obtained in order to guarantee that no nontrivial warping function on the Riemannian factor can make the standard static space-time Einstein. (C) 2004 Elsevier Ltd. All rights reserved.
