Yayınlar
Koleksiyondaki öğeler
- MakaleYalnız künye2010Scopus SJRQ1Multiobjective optimization of angle-ply laminated plates for maximum buckling load
Topal, Umut; Uzman, Ümit
This paper deals with multiobjective optimization of symmetrically angle-ply square laminated plates subjected to biaxial compressive and uniform thermal loads. The design objective is the maximization of the buckling load for weighted sum of the biaxial compressive and thermal loads. The design variable is the fiber orientations in the layers. The performance index is formulated as the weighted sum of individual objectives in order to obtain optimal solutions of the design problem. The first-order shear deformation theory (FSDT) is used in the mathematical formulation of buckling analysis of laminated plates. The modified feasible direction (MFD) method is used for optimization routine. For this purpose, a program based on FORTRAN is used. Finally, the effect of different weighting factors, number of layers, aspect ratios, load ratios and boundary conditions on the optimal design is investigated.
AtıfScopus24WoS22OpenAlex26
İncele - BildiriYalnız künye2011Ambient and forced vibration tests of a box girder concrete bridge model
Altunisik, A.C.; Bayraktar, A.; Sevim, B.
In this paper, ambient and forced vibration tests of a box girder laboratory con-crete bridge model are described to obtain experimental dynamic characteristics such as natural frequencies, mode shapes and damping ratios. The bridge deck consists of a main span of 3m and two side span of 1.5m each. The total bridge length is 6m and width of bridge is 0.60m. Heights of the bridge column and bridge deck are 0.80m and 0.30m, respectively. In the forced vibration tests, excitation of the bridge model is induced by an impact hammer. The ambient vibration tests are conducted under natural excitation such as wind and small impact effects. The Enhanced Frequency Domain Decomposition method in the frequency domain and the Sto-chastic Subspace Identification method in the time domain are used to extract the dynamic characteristics. At the end of the study, dynamic characteristics obtained from ambient and force vibration tests are compared with each other. It is seen that there is a good agreement be-tween both results and they are nearly closed to each other.
- MakaleAçık Erişim2015Scopus SJRQ3Prediction of pedal cyclists and pedestrian fatalities from total monthly accidents and registered private car numbers
Ghasemlou, Kiarash; Aydin, Metin Mutlu; Yildirim, Mehmet Sinan
Accident prevention is relatively a complex issue considering the effectiveness of the injury prevention technologies as well as more detailed assessment of the complex interactions between the road condition, vehicle and human factor. For many years, highway agencies and vehicle manufacturers showed great efforts to reduce the injuries resulting from the vehicle crashes. Many researchers used a broad range of methods to evaluate the impact of several factors on traffic accidents and injuries. Recent developments lead up to capable for determining the effects of these factors. According to World Health Organization (WHO), cyclists and pedestrians comprise respectively 1.6% and 16.3% in traffic crash fatalities in 2013. Also in Turkey crash fatalities for pedestrian and cyclists are respectively 20.6% and 3% according to Turkish Statistical Institute data in 2013. The relationship between cycling and pedestrian rates and injury rates over time is also unknown. This paper aims to predict the crash severity with the traffic injury data of the Konya City in Turkey by implementing the Artificial Neural Networks (ANN), Regression Trees (RT) and Multiple Linear Regression modelling (MLRM) method.
AtıfScopus10OpenAlex12İncele - MakaleAçık Erişim2013Scopus SJRQ1The nature of transition from adakitic to non-adakitic magmatism in a slab window setting: A synthesis from the eastern Pontides, NE Turkey
Eyuboglu, Yener; Santosh, M.; Dudas, Francis O.; Akaryali, Enver; Chung, Sun-Lin; Akdaǧ, Kemal; Bektaş, Osman
The eastern Pontides orogenic belt provides a window into continental arc magmatism in the Alpine-Himalayan belt. The late Mesozoic-Cenozoic geodynamic evolution of this belt remains controversial. Here we focus on the nature of the transition from the adakitic to non-adakitic magmatism in the Kale area of Gumushane region in NE Turkey where this transition is best preserved. The adakitic lithologies comprise porphyries and hyaloclastites. The porphyries are represented by biotite-rich andesites, hornblende-rich andesite and dacite. The hayaloclastites represent the final stage of adakitic activity and they were generated by eruption/intrusion of adakitic andesitic magma into soft carbonate mud. The non-adakitic lithologies include basaltic-andesitic volcanic and associated pyroclastic rocks. Both rock groups are cutting by basaltic dikes representing the final stage of the Cenozoic magmatism in the study area. We report zircon U-Pb ages of 48.71 ± 0.74 Ma for the adakitic rocks, and 44.68 ± 0.84 Ma for the non-adakitic type, suggesting that there is no significant time gap during the transition from adakitic to non-adakitic magmatism. We evaluate the origin, magma processes and tectonic setting of the magmatism in the southern part of the eastern Pontides orogenic belt. Our results have important bearing on the late Mesozoic-Cenozoic geodynamic evolution of the eastern Mediterranean region.
AtıfScopus77OpenAlex82İncele - MakaleYalnız künye2012Scopus SJRQ2Remote sensing and GIS-based landslide susceptibility mapping using frequency ratio and analytical hierarchy methods in Rize province (NE Turkey)
Reis, S.; Yalcin, A.; Atasoy, M.; Nisanci, R.; Bayrak, T.; Erduran, M.; Sancar, C.; Ekercin, S.
The northeast part of Turkey is prone to landslides because of the climatic conditions, as well as geologic and geomorphologic characteristics of the region. Especially, frequent landslides in the Rize province often result in significant damage to people and property. Therefore, in order to mitigate the damage from landslides and help the planners in selecting suitable locations for implementing development projects, especially in large areas, it is necessary to scientifically assess susceptible areas. In this study, the frequency ratio method and the analytical hierarchy process (AHP) were used to produce susceptibility maps. Especially, AHP gives best results because of allowing better structuring of various components, including both objective and subjective aspects and comparing them by a logical and thorough method, which involves a matrix-based pairwise comparison of the contribution of different factors for landslide. For this purpose, lithology, slope angle, slope aspect, land cover, distance to stream, drainage density, and distance to road were considered as landslide causal factors for the study area. The processing of multi-geodata sets was carried out in a raster GIS environment. Lithology was derived from the geological database and additional field studies; slope angle, slope aspect, distance to stream, distance to road and drainage density were invented from digital elevation models; land cover was produced from remote sensing imagery. In the end of study, the results of the analysis were verified using actual landslide location data. The validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.
AtıfScopus87WoS73OpenAlex100İncele - MakaleYalnız künye2013Scopus SJRQ2Increasing single-lap joint strength by adherend curvature-induced residual stresses
Temiz, Ş.; Akpinar, S.; Aydin, M.D.; Sancaktar, E.
Single-lap joint (SLJ) geometry is the most widely used type of adhesive joint geometry. In this joint, peel stresses occur at the overlap ends due to load eccentricity and the presence of shear-free adhesive termination surfaces. These peel stresses, along with the transverse tensile stresses which occur along the overlap longitudinal axes, and adhesive shear stresses, ultimately cause joint failure. Obviously, reductions in these stresses should result in higher joint strength and increased load capacity. To this end, we exploited elastic spring-back capability of (steel) metal adherends by initially forming curved segments of varying arc lengths and radii at overlap ends. These adherends with curved-end sections were then bonded in single-lap configuration, simply by applying sufficient bonding pressure to elastically flatten the curved segments to result in typically flat overlap sections subsequent to adhesive cure and the removal of bonding pressure. Since the elastic adherend overlap ends tend to revert back to their initial curved form, they exert compressive residual stresses on the adhesive layer in the overlap end regions. We determined that the compressive residual stresses induced in this fashion considerably increased the load capacity of SLJs subjected to tension.
AtıfScopus18WoS18İncele - MakaleAçık Erişim2014Scopus SJRQ2Kinetics, thermodynamics, and equilibrium evaluation of adsorptive removal of methylene blue onto natural illitic clay mineral
Ozdes, Duygu; Duran, Celal; Senturk, Hasan Basri; Avan, Hilal; Bicer, Burcin
The natural illitic clay mineral (NICM) has been used as a low cost and highly effective adsorbent in the removal of a toxic cationic dye, methylene blue (MB), from aqueous solution by a batch adsorption technique. The effects of experimental parameters such as initial pH of the aqueous solution, contact time, initial MB concentration, adsorbent concentration, ionic strength, and temperature were studied in detail upon the adsorption process. The process was found to be independent of initial solution pH and the adequate equilibrium time for the adsorption of MB onto NICM was only 60 m. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models and showed a good fit with both the Langmuir and Freundlich isotherm models. The monolayer adsorption capacity of NICM was found to be 24.87 mg g-1 by using Langmuir isotherm model. The kinetics of the adsorption were tested using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The results showed that the adsorption of MB onto NICM proceeds according to the pseudo-second-order model. Thermodynamic parameters indicated that the present adsorption process was feasible, spontaneous, and endothermic in nature.
AtıfScopus45WoS39OpenAlex51İncele - MakaleAçık Erişim2013Scopus SJRQ2Testing for causality between the foreign direct investment, current account deficit, GDP and total credit: Evidence from G7
Akbas, Yusuf Ekrem; Senturk, Mehmet; Sancar, Canan
In this study, countries were analyzed between 1990 and 2011 in order to determine whether a causal relationship exists among current account deficit, GDP, foreign direct investment, and total credits of G7. Analysis took into account the cross-sectional dependence and was applied to test the causality among the variables form the panel. Firstly, panel unit root tests were used for determining stationary of variables. As a result of the panel unit root tests, it was found that GDP and foreign direct investment have a stationary structure and that total credits and current account deficit contain unit root. In order to see whether there is a long-term relationship among the variables or not, the panel co-integration test was used. As a result of the test, it was concluded that there is a co-integration relationship among the series. The possibility of a causal relationship was analyzed among the variables using the causality test developed by Elena Ivona Dumitrescu and Christophe Hurlin (2012). Results of the analysis showed a unidirectional causal relationship from current account deficit and foreign direct investment to GDP. Bidirectional causality was found between current account deficit and total credits. Finally, a unidirectional relationship was found from foreign direct investment to current account deficit and total credits.
AtıfScopus25WoS26OpenAlex63İncele - MakaleYalnız künye2014Scopus SJRQ1Synthesis of cyclohexane derivatives including Br, Cl, N, O, and S at 1,2,4,5-positions: Selectivity in addition reactions Dedicated to Professor Dr. Metin Balci on the occasion of his 65th anniversary
Kaya, Afşin Ahmet; Menzek, Abdullah; Şahin, Ertan
Brominations of mono addition products of 1,4-cyclohexadiene with 2,4-dinitrobenzenesulfenyl chloride (RSCl) selectively gave 1R(S),2R(S),4R(S), 5R(S)-4,5-dibromo-2-(2,4-dinitrophenylthio)cyclohexyl acetate and 1R(S),2R(S),4R(S),5R(S)-4,5-dibromo-2-chlorocyclohexyl)(2,4-dinitrophenylthio) sulfane. From series reactions 7-oxabicyclo[4.1.0]hept-3-ene with reagents, such as RSCl, NaN3, and H2SO4/Ac2O, six 1,2,4,5-tetrasubstituted cyclohexane derivatives including S, O, N, Cl, and Br were selectively obtained. Formations and structures of the products were discussed.
AtıfScopus6WoS5OpenAlex10İncele - MakaleAçık Erişim2011Scopus SJRQ1In vitro inhibition of α-carbonic anhydrase isozymes by some phenolic compounds
Öztürk Sarikaya, Sevim Beyza; Topal, Fevzi; Şentürk, Murat; Gülin, Ihami; Supuran, Claudiu T.
Carbonic anhydrase inhibitors (CAIs) are a class of pharmaceuticals used as antiglaucoma agents, diuretics, antiepileptics, in the management of mountain sickness, gastric and duodenal ulcers, neurological disorders or osteoporosis. We report here the inhibitory capacities of some phenolic compounds against three human CA isozymes (hCA I, hCA II, and hCA VI) and the gill carbonic anhydrase of the teleost fish Dicentrarchus labrax (European seabass) (dCA). The isozymes showed quite diverse inhibition profiles with these compounds. These data may lead to design novel CAIs with a diverse inhibition mechanism compared to sulfonamide/sulfamate inhibitors.
AtıfScopus179WoS171OpenAlex175
İncele - MakaleAçık Erişim2012Scopus SJRQ1Exergetic evaluation of speed and load effects in spark ignition engines; [Évaluation exergétique des effets de la vitesse et de la charge dans les moteurs à allumage par étincelle]
Sezer, I.; Bilgin, A.
This study investigates the effects of various operating conditions in spark ignition engines via an exergy analysis. A thermodynamic cycle model including compression, combustion and expansion processes was used for investigation. Induction and exhaust processes were computed with a simple approximation method. The principles of the second law were applied to the cycle model to perform the exergy analysis. Exergetic variables, i.e., the exergy transfers with heat and work, irreversibilities, thermomechanical exergy, fuel chemical exergy and total exergy were calculated in the exergy analysis. Variation of the exergetic parameters and the distribution of them into the fuel exergy were determined for various operating conditions, i.e., engine speed and load. The first and second law efficiencies and specific fuel consumption were also computed to reveal the optimum operating conditions. The results show that the exergy transfer with heat decreases and the exergy transfer with exhaust gases increases with increasing engine speed. Engine speed of 3 000 rpm gives the maximum exergy transfer as work, the minimum irreversibility and the best efficiency and fuel consumption. Exergy transfers with heat, work and exhaust and irreversibilities increase with increasing engine load. Additionally, the first and second law efficiencies increase and fuel consumption decreases with increasing engine load, so a high engine load gives the best efficiency and fuel consumption.
AtıfScopus7WoS7OpenAlex9İncele - EditoryalYalnız künye2013Preface
Christiansen, Bryan; Yildiz, Salih; Yildiz, Emel
As technology continues to drive innovation and impact societies across multiple national boundaries and cultures, new approaches towards marketing products must be created and implemented to be successful in an era of hypercompetition. Transcultural Marketing for Incremental & Radical Innovation provides in depth discussion on tactics for improving existing products while inventing completely new products and product categories. This publication will prove to be helpful for scholars, practitioners, and university students who wish to better understand the importance of marketing products and services across different cultures and multiple languages.
AtıfScopus1OpenAlex14İncele - MakaleYalnız künye2013Scopus SJRQ1Assessment of wave energy resource of the Black Sea based on 15-year numerical hindcast data
Akpinar, Adem; Kömürcü, Murat I.hsan
In this study, the existence and variability of wave energy resource potential of the Black Sea based on 15-year hindcast data is described in detail. The hindcasts of wave parameters were carried out by using the third generation wave prediction model (Simulated WAves Nearshore - SWAN), which is one of the most popular numerical wave models and has been widely used for estimating ocean waves. The model was forced with the ECMWF ERA Interim wind fields and applied with a spatial resolution of about 0.0167°. ×. 0.0167° and a model time step of 6. h to resolve efficiently offshore and nearshore wave conditions. The results were presented in the form of charts of the spatial distribution of significant wave height and wave power, on a monthly, seasonal and annual basis. Annual energy was calculated in the study region with the hindcast data set covering 15. years (1995-2009). The areas with the highest wave energy resource were determined and the south west coasts of the Black Sea are suggested as the best site for the installation of a wave farm. It was determined the western parts of the Black Sea (especially the south-west) are exposed to energetic waves more than the eastern parts.
AtıfScopus167WoS155OpenAlex180İncele - MakaleYayıncıda açık erişim2014Scopus SJRQ1Characterization of rosehip (Rosa canina L.) seed and seed oil
Ilyasoǧlu, Huri
In this study, the nutritional composition and phytochemical composition of the rosehip seed, and the fatty acid and sterol compositions of the seed oil were investigated. The rosehip seed contained valuable phytochemicals such as phenolic compounds (2554 μg/g), carotenoids (2.92 μg/g), and ascorbic acid (1798 μg/g). Furthermore, the rosehip-seed oil was rich in polyunsaturated fatty acids, linoleic acid (54.05%), linolenic acid (19.37%), and phytosterols, mainly β-sitosterol (82.1%). The rosehip seed and seed oil were found to have antioxidant activity measured by trolox equivalent antioxidant capacity assay. It can be concluded that the rosehip seed and seed oil may be utilized as a source of phytonutrients.
AtıfScopus106WoS96OpenAlex111İncele - MakaleYalnız künye2012Scopus SJRQ4Statistical correlation between b-value and fractal dimension regarding Turkish epicentre distribution
Öztürk, Serkan
This study was aimed at analysing the relationship between seismic b-value and fractal dimension Dc-value for Turkish epicentres. The earthquake catalogue consisting of 99,737 instrumentally-registered Turkish events was analysed for the period between 1970 and 2011; Turkey was divided into 55 tectonic zones for making a detailed comparison. The b-values were calculated by the maximum likelihood method and the Dc-values were obtained with 95% confidence limits by linear regression. The results showed that higher Dc-values were associated with lower b-values and this could have been an indication of relatively high stress intensity and stronger epicentre clustering in these regions. Orthogonal regression was used to estimate a suitable statistical correlation between two seismotectonic parameters; the Dc = 2.44 - 0.30*b relationship was obtained with a strong negative correlation (r = -0.82) between b-value and Dc-value for Turkish earthquake distribution. This seemed to agree with other regional results obtained for different parts of Turkey and the rest of the world.
AtıfScopus25WoS17İncele - MakaleYalnız künye2011Scopus SJRQ2Total electricity and hydroelectric energy generation in Turkey: Projection and comparison
Akpinar, A.; Kömürcu, M.I.; Özölçer, I.H.; Şenol, A.
The main goal of this study is to forecast total electricity and hydroelectricity energy generation using historical electricity energy production data in order to determine the future level of electricity and hydroelectricity energy generation in Turkey. For this purpose, Turkey's electricity energy sector was reviewed during the period of 1940-2005. The total electricity and hydroelectricity energy generation were then modelled using historical energy generation data as years with regression analysis. Additionally, the portion that hydroelectric energy generation of Turkey has within total electricity energy production and probable meeting capacity of Turkey's hydroelectric potential of its future total demand was determined. According to the results, it is deduced that hydropower energy will have portion of 13.6% within the total electricity energy generation in 2030. In addition, it is concluded that the whole of Turkey's technical and economical hydroelectric energy potential that is equal 129.9 billion kWh will be used in the year of 2102 if the current trend continues.
AtıfScopus6WoS5OpenAlex7İncele - MakaleYalnız künye2011Scopus SJRQ1Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses
Sevim, Bariş; Bayraktar, Alemdar; Can Altunişik, Ahmet
This study determines the water length effects on the modal behavior of a prototype arch dam using Operational and Analytical Modal Analyses. Achievement of this purpose involves construction of a prototype arch dam-reservoir- foundation model under laboratory conditions. In the model, reservoir length was taken to be as much as three times the dam height. To determine the experimental dynamic characteristics of the arch dam using Operational Modal Analysis, ambient vibration tests were implemented for empty reservoir and three different reservoir water lengths. In the ambient vibration tests, the dam was vibrated by natural excitations provided from small impact effects and the response signals were measured using sensitive accelerometers. Operational Modal Analysis software process signals collected from the ambient vibration tests, and Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques estimated modal parameters of the dams. To validate the experimental results, 3D finite element model of the prototype arch dam was modeled by ANSYS software for empty reservoir and three different reservoir water lengths, and dynamic characteristics of each model were determined analytically. At the end of the study, experimentally and analytically identified dynamic characteristics compared to each other. Also, changes on the natural frequencies along to water length are plotted as graphs. Results suggest that reservoir water complicates the modal behavior of the arch dam significantly.
AtıfScopus26WoS22OpenAlex21İncele - MakaleYalnız künye2013Scopus SJRQ1Production of human fat milk analogue containing α-linolenic acid by solvent-free enzymatic interesterification
Ilyasoglu, Huri
Human milk fat (HMF) analogue was synthesized by lipase-catalysed interesterification of tripalmitin with extra virgin olive oil, and flaxseed oil in a solvent-free media. Lipozyme® TL IM, immobilized sn-1,3 specific lipase, was used as biocatalysts. Substrate molar ratio, reaction temperature and reaction time were used to model and to optimize the reaction conditions via response surface methodology. Good quadratic models were obtained for the incorporation of palmitic acid and α-linolenic acid. At the optimal conditions generated from the model, the palmitic acid and α-linolenic acid contents of the product were found to be 25.2g/100g and 15.9g/100g, respectively. The chemical properties (free fatty acid, iodine value, and saponification value), sn-2 positional fatty acid composition, and sterol composition of the final structured lipid (SL) were determined. Furthermore, the oxidative stability of the SL and the SLs with antioxidants (BHT, gallic acid, and rosemary extract) was evaluated. The peroxide and thiobarbituric acid reactive substances (TBARS) values of the SLs showed they had antioxidant activity on the SL. The HMF analogue synthesized in this study may have potential use in infant formulas to provide omega-3 fatty acids (α-linolenic acid).
AtıfScopus18WoS14OpenAlex19İncele - MakaleAçık Erişim2013Scopus SJRQ4Evaluation of protein tyrosine phosphatase activity in patients with acute leukemia
Akdogan, Elif; Cengiz, Sevil; YIlmaz, Mustafa; Sönmez, Mehmet; Durmus, Ahmet; Oval, Ercüment; Omay, Serdar Bedii
Protein tyrosine phosphatases regulate physiological processes including growth, differentiation, metabolism and the cell cycle. Together with tyrosine kinases, they control the phosphorylation state of tyrosine residues of signaling proteins. An increased level of protein phosphorylation results in abnormal proliferation and many cancer types show a mutation or deletion of a protein tyrosine phosphatase gene. In this study we evaluated the protein tyrosine phosphatase activity in acute leukemia patients. Tyrosine phosphatase activity in bone marrow mononuclear cells of acute leukemia patients was measured using a tyrosine phosphatase assay system kit and compared with a control group. We found that tyrosine phosphatase activity in acute leukemia patients was high compared to the controls. According to subgroups of acute leukemia, tyrosine phosphatase activity in the AML-M2 subgroup was high compared to the controls. The effect of increased level of protein tyrosine phosphatase activity on leukemogenesis needs further evaluation. Studies in a large group of patients are needed to emphasize the importance of tyrosine phosphatase activity in acute leukemia patients.
AtıfScopus1WoS1OpenAlex1İncele - BildiriYalnız künye2011Scopus SJRQ4A logic simplification based on expert system application for TBC diagnosis
Sümbül, Harun; Başçiftçi, Fatih
Tuberculosis (TBC), caused by the bacterium My tuberculosis (Mtb), is a growing international health crisis [1]. TBC is one of the main causes of death produced by infectious illness and is responsible for almost 3 millions deaths every year [2]. In this study, a controlled Expert System (ES) have designed to diagnosis of TBC and truth table have created by considering the probabilities of TBC (12 symptom, 212=4096 different cases). According to the probabilities of TBC, 6 different cases have accepted as output values and reduced rule bases have obtained. These output values have been processed by an ES and have tried to diagnosis of TBC with help to ES. We obtained very good results and the results of analyses carried out indicated that controls performed with ES provide less time, less probability, reliable and consistent diagnosis and that are feasible in real life.
AtıfScopus1İncele
