Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2015Scopus SJRQ2Optimum design of steel space frames with composite beams using genetic algorithm
Artar, Musa; Daloʇlu, Ayşe T.
This paper presents an optimization process using Genetic Algorithm (GA) for minimum weight by selecting suitable standard sections from a specified list taken from American Institute of Steel Construction (AISC). The stress constraints obeying AISC-LRFD (American Institute of Steel Construction - Load and Resistance Factor Design), lateral displacement constraints being the top and inter-storey drift, mid-span deflection constraints for the beams and geometric constraints are considered for optimum design by using GA that mimics biological processes. Optimum designs for three different space frames taken from the literature are carried out first without considering concrete slab effects in finite element analyses for the constraints above and the results are compared with the ones available in literature. The same optimization procedures are then repeated for the case of space frames with composite (steel and concrete) beams. A program is coded in MATLAB for the optimization processes. Results obtained in the study showed that consideration of the contribution of the concrete on the behavior of the floor beams results with less steel weight and ends up with more economical designs.
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İncele - MakaleYalnız künye2019Scopus SJRQ2Investigation on seismic isolation retrofit of a historical masonry structure
Artar, Musa; Çoban, Keziban; Yurdakul, Muhammet; Can, Ömer; Yilmaz, Fatih; Yildiz, Mehmet B.
In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.
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İncele - MakaleAçık Erişim2018Scopus SJRQ2The assessment of knowledge economy efficienccomparing Turkey with the European Union countries; [Procjena učinkovitosti ekonomije znanja: Usporedba turske s državama Europske Unije]
Ayan, Tuba Yakıcı; Pabuçcu, Hakan
Knowledge economy is an economy that produces, distributes and uses information. Nowadays, investment in quality information rather than capital inputs is becoming more and more important for countries to develop and to be able to compete with each other. The increasing speed in the creation and spreading of knowledge has made it a crucial component in economic development. It is a fact that the countries that make large investments in information factors experience a fast and sustainable growth and are the most dynamic and competitive countries in the world. In this paper, we use context dependent DEA to measure the relative efficiency of the European Union (EU) countries’, including Turkey, knowledge economy policy based on 2016 data. In addition, we implement factor-specific DEA in order to identify achievable targets in short term for each output of countries. Four outputs and three inputs were used in the analysis. The results showed that Germany is clearly ahead of other countries such as France, England, Malta and the Netherlands. Turkey, on the other hand, separates from other countries and is the least efficient one. The reason for this separation is that Turkey produces less output than expected relative to its facilities. Another conclusion of the paper is that the countries’ patent applications and high-tech exports are more inefficient than other knowledge economy outputs.
AtıfScopus2WoS2İncele - MakaleYalnız künye2014Scopus SJRQ2Purification of paraoxonase enzyme from the sera of patients with behcet’s disease and analyzing the effects of the drugs containing imuran (azathioprine), prednisolone (methylprednisolone) and colchium (colchicine)
Demir, Nazan; Nadaroglu, Hayrunnisa; Ozkan, Asuman; Tasgin, Esen; Isik, Ceyhun; Demir, Yasar
In this study, serum samples from 50 patients with the diagnosis of Behcet’s disease and 20 healthy volunteers were analyzed. The study consists of three parts. In the first part, paraoxonase (PON) activities were determined in the serum samples of 50 patients with Behcet’s disease and 20 healthy people. In the second part, equal volumes of serum samples from 50 patients were pooled and PON enzymes were purified by using Sepharose-4B-L-tyrosine tyrosine-1-naphtylamine affinity column. Optimum temperature, optimum pH, Vmax and Km values of the pure enzymes were determined. The same purification procedure was also performed in the serum samples of 20 healthy people. Electrophoretic mobility was observed (via SDS-PAGE) in the PON enzymes that were purified from the serum samples of patients with Behcet’s disease and healthy people. In the third part, in vitro effects of drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of Behcet’s disease were tested on the PON enzymes of the patients with Behcet’s disease and control group. IC50 values and Ki constant values were measured and inhibition types were determined for the drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of the Behcet’s disease and demonstrate in vitro inhibition effects.
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İncele - MakaleYalnız künye2014Scopus SJRQ4Existence and uniqueness of solutions of a nonlocal problem involving the p(x)-Laplacian
Avci, M.; Ayazoglu, R.
The object of this paper is to study a nonlocal problem involving the p(x)-Laplacian where nonlinearities f do not necessarily satisfy the classical conditions, such as Ambrosetti-Rabinowitz condition, but are limited by functions that do satisfy some specific conditions. By using the direct variational approach and the theory of the variable exponent Sobolev spaces, the existence and uniqueness of solutions is obtained.
AtıfScopus1İncele - MakaleAçık Erişim2017Scopus SJRQ1A smart building material for low/zero carbon applications: Heat insulation solar glass-characteristic results from laboratory and in situ tests
Cuce, Erdem; Riffat, Saffa B.
Heat insulation solar glass (HISG) is a recently developed smart building material to minimize energy consumption of building sector. HISG might be presumed to be a conventional photovoltaic glazing product; however, it is completely unique by having some characteristic features such as superior thermal insulation, which is competitive with triple-glazed windows using argon as inert gas, acoustic and thermal comfort, self-cleaning ability owing to TiO2 nano-coating on module surface and extraordinary energy saving potential in both summer and winter. In our previous works, comprehensive experimental and numerical works have been carried out for power generation and thermal insulation performance of HISG under various climatic conditions. Within the scope of this research, optical- and lighting-related performance parameters of this smart building material are evaluated through extensive laboratory and in situ tests. Shading coefficient, visible light intensity, and UV and IR penetration are investigated via the tests conducted in real operating conditions. It is achieved from the results that the shading coefficient of HISG is only 0.136, which yields almost 80% reduction in solar heat gain compared with ordinary glazing. It is also observed from the in situ tests that HISG has a %100 UV and 99% IR blocking rate, which is of vital importance in terms of human health and thermal comfort conditions. Glaring effects are totally resolved via HISG, which is still a challenge for the buildings with conventional glazing products, especially in summer.
AtıfScopus26WoS22OpenAlex13İncele - MakaleAçık Erişim2019Scopus SJRQ3Biodiversity and characterization of gram-positive, catalase-positive cocci isolated from pastırma produced under different curing processes
Fettahoğlu, Kübra; Çinar, Kübra; Kaya, Mükerrem; Kaban, Güzin
The aim of this study was to determine the effects of different curing temperatures (4 °C or 10 °C) and agents (KNO3 or NaNO2) on microbiological and physicochemical properties of pastırma and diversity of gram-positive, catalase-positive cocci (GCC+) and also to investigate some technological properties of the strains. Four different groups of pastırma were produced applying different curing temperatures and agents. After production, GCC+ isolated from pastırma were subjected to phenotypic and genotypic (16S rRNA sequencing) identification. Genotypically characterized strains were evaluated for their technological properties. In all groups, aw and pH were observed to be under 0.90 and over 5.5, respectively. In genotypic identification, 45 isolates were identified as Staphylococcus vitulinus, while other isolates identified were S. equorum (n = 15), S. saprophyticus (n = 15), and S. xylosus (n = 12). All of the strains could grow at different salt concentrations (8% and 15%) and temperatures (4 °C, 10 °C, and 37 °C). Four strains of S. saprophyticus showed strong lipolytic activity while nine strains of S. vitulinus had strong proteolytic activity. This study showed that different curing temperatures and agents are particularly effective on the microflora in pastırma; however, these factors do not cause a high diversity in GCC+ in terms of species.
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İncele - MakaleYalnız künye2019Scopus SJRQ4Comparison of cationic dyes (basic orange 2, basic yellow 2 and basic violet 3) removal from aqueous solution using clay as an adsorbent
Farizoglu, Burhanettin; Fil, Baybars Ali; Sozudogru, Onur; Aladag, Erdinc; Kul, Sinan
The present work aims to investigate the removal of three cationic dyes (Basic Orange 2, Basic Yellow 2 and Basic Violet 3) from aqueous solutions by montmorillonite under various experimental conditions. Cationic dyes were selected Basic Orange 2 (BO2), Basic Yellow 2 (BY2) and Basic Violet 3 (BV3). The effects of pH, initial dye concentration, adsorbent dose, agitation speed and ionic strength, on the removal of dyes were studied. According to the experiments results, it was shown, that maximum removal was achieved in less than 45 min. The results indicate that the montmorillonite can be used as a low cost alternative according to other adsorbents in the removal of dyes from wastewater. The maximum adsorption efficiency levels attained were as follows: 95.849% BO2, 99.562% BY2 and 99.169% BV3 onto montmorillonite at pH: 5.0, 100 mg/L initial dye concentration, 0.75g/L clay dosage, 300 rpm agitation speed, 0 M NaCl ionic strength and 293 K, reaction time of 45 min.
AtıfScopus2İncele - MakaleAçık Erişim2019Scopus SJRQ3A signal timing assignment proposal for urban multi lane signalised roundabouts
Murat, Yetis Sazi; Cakici, Ziya; Tian, Zong
The relationship between the left-turning traffic volume and the storage area at signalised roundabouts is investigated, and a calculation procedure for signal timing is proposed in this paper. The parameters associated with the developing stages of a new expression/ model are also defined. Four different signal timing scenarios are considered. The results show that the proposed formula can be used for the design of signalised roundabouts.
AtıfScopus11WoS7OpenAlex9İncele - MakaleYalnız künye2016Scopus SJRQ3On the boundedness of a B-Riesz potential in the generalized weighted B-Morrey spaces
Ayazoglu, Rabil; Hasanov, Javanshir J.
We consider the generalized shift operator associated with the Laplace-Bessel differential operator Δ B = i=1 n 2 x i 2 +i=1 k γ i x ix i .Δ -B=Σ -i=1ⁿ(∂ ²)/(∂ x-i²) +Σ -i=1^k (γ -i)/(x-i)(∂)/(∂ x-i). The maximal operator M γ M-γ (B-maximal operator) and the Riesz potential I α,γ I-α ,γ (B-Riesz potential), associated with the generalized shift operator are investigated. We prove that the B-maximal operator M γ M-γ and the B-singular integral operator are bounded from the generalized weighted B-Morrey space p,ω 1 ,φ,γ (k,+ n )cal M-p,ω -1,φ ,γ (ℝ-k,+ⁿ) to p,ω 2 ,φ,γ (k,+ n )cal M-p,ω -2,φ ,γ (ℝ-k,+ⁿ) for all 1<p<1 < p < ∞ , φA p,γ (k,+ n )φ ∈ A-p,γ (ℝ-k,+ⁿ) . Furthermore, we prove that the B-Riesz potential I α,γ I-α ,γ , 0<α<n+|γ|0<α <n+|γ | , is bounded from the generalized weighted B-Morrey space p,ω 1 ,φ,γ (k,+ n )cal M-p,ω -1,φ ,γ (ℝ-k,+ⁿ) to q,ω 2 ,φ,γ (k,+ n )cal M-q,ω -2,φ ,γ (ℝ-k,+ⁿ) , where α/(n+|γ|)=1/p-1/qα /(n+|γ |)=1/p-1/q , 1<p<(n+|γ|)/α1<p<(n+|γ |)/α , φA 1+q/p ' ,γ (k,+ n )φ ∈ A-1+q/p^′,γ (ℝ-k,+ⁿ) and 1/p+1/p ' =11/p+1/p^′=1 .
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2018Scopus SJRQ2Effect of different levels of grapeseed (Vitis vinifera) oil addition on physicochemical, microbiological and sensory properties of set-type yoghurt
Mercan, Emİn; Sert, Durmuş; Karakavuk, Emrah; Akın, Nİhat
The aim of this study was to determine the effect of different concentrations of grapeseed oil (GSO) addition (0.5%, 1% and 1.5% w/v) to yoghurt milk on survival of starter bacteria, and physicochemical, textural and sensory properties of set-type yoghurts during the 21 days of storage. Moreover, radical scavenging activity (RSA) and total phenolic content (TPC) of yoghurts were investigated. Yoghurts containing GSO exhibited significantly higher TPC and RSA as compared to control yoghurts. The results obtained from this investigation show that GSO has a potential to be used as a food supplement to improve health-promoting properties of yoghurt.
AtıfScopus17WoS15OpenAlex16İncele - MakaleAçık Erişim2018Scopus SJRQ2Effect of grain refinement and phase composition on room temperature superplasticity and damping capacity of dual-phase Zn-Al alloys
Demirtas, Muhammet; Atli, Kadri C.; Yanar, Harun; Purcek, Gencaga
The effects of grain refinement and phase composition on superplasticity and damping capacity of eutectic Zn-5Al and eutectoid Zn-22Al alloys were investigated. For grain refinement, equal-channel angular pressing (ECAP) was applied to these alloys. ECAP completely eliminated the as-cast lamellar microstructures of both alloys and resulted in ultrafine-grained structures along with room temperature superplasticity. Furthermore, these microstructural changes with ECAP increased the damping capacity of both alloys in the dynamic hysteresis region, where damping arises from viscous sliding of phase/grain boundaries. Dynamic recrystallization at the surface and thermally activated viscous motion of grain/phase boundaries at the subsurface of the samples of both alloys were proposed as the damping mechanisms in the region where the alloys showed combined aspects of static/dynamic hysteresis damping behavior. Although the grain size is larger in Zn-5Al compared to Zn-22Al, it showed higher damping capacity due to the different sliding characteristics of its phase boundaries.
AtıfScopus14WoS11OpenAlex14İncele - MakaleYalnız künye2019Scopus SJRQ1Vertically oriented graphene nano-sheets grown by plasma enhanced chemical vapor deposition technique at low temperature
Bayram, Ozkan; Simsek, Onder
In this study, it was aimed to obtain vertically-oriented graphene nano-sheets (VGNs) on copper foils using CH 4 gas as the precursor material by means of plasma enhanced chemical vapor deposition (PECVD) technique. VGNs were obtained at 50 W, 75 W and 100 W Radio Frequency (RF) powers by this technique and the effect of RF power on the morphological structure of graphene layers was investigated. VGNs were also analyzed by Raman spectroscopy, scanning electron microscopy (SEM) and water contact angle (WCA) measurements. The SEM images showed that the VGNs became more tightly packed with the increase of RF power and thus these coating parameters had a significant effect on the morphological structure. WCA analyzes for VGNs were also performed and it was found that VGNs obtained at 100 W RF power had higher contact angle value than the other RF powers. These VGNs, which have both large surface area and optically transparent, are thought to be materials that have the potential to be used in supercapacitors and solar cells.
AtıfScopus19WoS17OpenAlex19İncele - MakaleYalnız künye2019Scopus SJRQ4Fatty acid composition of sunflower seeds from different locations in the north of Turkey
Gul, Volkan
Because of sunflower is well adapted to the conditions of all region types, it ranks the first in terms of vegetable oil production in our country. The content of fatty acids that determine the quality of sunflower oil is affected by factors such as genotype and environment, especially climate and soil struc-ture. This research examines the oil and fatty acid ratios of sunflower grains grown on a producer basis and presented to the market in 2015 in Samsun (Bafra, Vezirkopru and Havza), Amasya (Merzifon), Corum (Center) and Tokat (Turhal) in the Middle Black Sea Region selected according to the density of oil sunflower to determine the quality of oil. According to the results of the research, average fat ratio was found to be between 41.57% and 45.67%, palmitic and stearic acids, which are basic saturated fatty acids, between 5.65% and 6.44% and from 3.84% and 4.81% linoleic acid (omega 6), linolenic acid (omega 3) and oleic acids (omega 9), which are unsaturated fatty acids, were found between 50.33 and 63.42%, 0.24 and 0.29% and 25.32 and 37.50%, respectively. These results indicate that the sun-flower seeds cultivated in the Amasya-Merzifon re-gion are at the forefront due to their oil quality char- A cteristics.
- MakaleYalnız künye2015Scopus SJRQ1Evaluation of polycyclic aromatic hydrocarbons in Circassian cheese by high-performance liquid chromatography with fluorescence detection
Gul, Osman; Dervisoglu, Muhammet; Mortas, Mustafa; Aydemir, Oguz; Ilhan, Eda; Aksehir, Kubra
Polycyclic aromatic hydrocarbons (PAH) in traditional/industrial smoked and unsmoked Circassian cheeses available in Turkish markets were analysed using solid-phase extraction, followed by high-performance liquid chromatography (HPLC) with fluorescence detection. Mean levels of a total of 9 PAHs in smoked traditional and industrial Circassian cheeses were 19.6 and 6.73μgkg-1, while levels in unsmoked traditional and industrial cheeses were 0.77 and 0.49μgkg-1, respectively. The dominant individual PAHs found were naphthalene and acenaphthene. Benzo[a]pyrene, a marker compound representing carcinogenic PAHs, was found in 90% and 30% of traditional smoked and unsmoked Circassian cheeses, 52% and 24% of industrial smoked and unsmoked cheeses, respectively. Correlation statistical analysis showed that benzo[a]pyrene was a good marker for total 9 PAHs in Circassian cheese samples (rB[a]P/sum of 9 PAHs=0.816, p<0.01) as well as the best marker for 5 carcinogenic PAHs (rB[a]P/carcinogenic PAHs=0.904, p<0.01). Risk assessment conducted using daily intakes of sum of 9 PAH levels found in both traditional and industrial smoked Circassian cheese samples showed high risk compared with unsmoked cheeses.
AtıfScopus22WoS21OpenAlex20İncele - MakaleAçık Erişim2016Scopus SJRQ1Fuzzy multicriteria decision making method based on the improved accuracy function for interval-valued intuitionistic fuzzy sets
Şahin, Rıdvan
A new accuracy function for the theory of interval-valued intuitionistic fuzzy set, which overcomes some difficulties arising in the existing methods for determining rank of interval-valued intuitionistic fuzzy numbers, is proposed by taking into account the hesitancy degree of interval-valued intuitionistic fuzzy sets. By comparing it with several proposed accuracy functions, the necessity and efficiency of our accuracy function are provided by giving related examples. A fuzzy multicriteria decision making method is established to select the best alternative in multicriteria decision making process which is taken as interval-valued intuitionistic fuzzy set of criterion values for alternatives. While aggregating the interval-valued intuitionistic fuzzy information corresponding to each alternative, we utilize the interval-valued intuitionistic fuzzy weighted aggregation operators. Then the accuracy degree of the aggregated interval-valued intuitionistic fuzzy information is computed via the new proposed accuracy function. Thus, we can rank all the alternatives according to the accuracy function and choose the optimal one(s). Finally, an illustrative example is given to demonstrate the practicality and effectiveness of the proposed approach.
AtıfScopus76WoS61OpenAlex83İncele - MakaleYalnız künye2016Scopus SJRQ3The islamic banking and economic growth nexus: A panel VAR analysis for organization of islamic cooperation (OIC) countries
Zirek, Duygu; Celebi, Fusun; Kabir Hassan, M.
In this paper, we investigate the impact of Islamic banking variables on economic growth in a panel setting for 14 member countries of the Organization of Islamic Countries during 1999-2011 period. We examine the short-run effects as well as long-run effects by employing the Panel VAR method. We find a positive and significant relationship between Islamic finance and economic growth. This relationship is robust with regard to several macroeconomic control variables such as capital stock, unemployment, inflation, and government expenditure. We show that an increase in the share of Islamic deposits, assets, and loans in total banking instruments results in an increase in economic growth. The results also show that in the long run, economic growth responds positively to shocks in Islamic instruments, namely Islamic deposits, investments, and size. Shocks in Islamic banking contribute to more than 3% of the forecast error in economic growth in the next 10 year period.
AtıfScopus23İncele - MakaleYalnız künye2018Scopus SJRQ43-D simulation of simultaneous heat and mass transfer of apple
Turkan, B.; Canbolat, A.S.; Etemoglu, A.B.
Drying is a complex process associated with the coupled mechanism of heat and mass transfer which plays an important role in almost all industrial sectors. For this reason, the intensive research on drying is carried on specially based on optimisation of energy and process control. The aim of this study is to present a numerical method for drying processes widely used in food industries to provide enhanced product quality and economically advantages at definite production conditions. The governing equations of drying process in a 3-D rectangular object (e.g. apple slices) are solved numerically to predict the temperature and moisture distributions inside the object. Then, statistical tests of agreement between results are performed by determining the coefficient of regression (R2), chi-square test (2) and standard error of estimate (SEE) values, and it is found that predicted results agree well with the results in literature. Finally, a parametric study is conducted to emphasize the role of parameters on food drying as an important contributor to energy consumption.
AtıfScopus2İncele - MakaleAçık Erişim2018Scopus SJRQ3Qualitative and quantitative structure-activity relationships studies of quercetin derivatives as chemotherapeutic activity
Rouane, Abderrahmane; Tchouar, Noureddine; Kerassa, Aicha; Cinar, Mehmet; Belaidi, Salah
Qualitative and Quantitative structure activity relationship (SAR/QSAR) analysis was applied to eighteen Quercetin derivatives using a combination of various physicochemical, steric, electronic, and structural molecular descriptors. A multiple linear regression (MLR) procedure was used to model the relationships between molecular descriptors and the chemotherapeutic activity of the Quercetin derivatives. The stepwise regression method was used to derive the most significant models as a calibration model for predicting the inhibitory activity of this class of molecules. The best QSAR models were further validated by a leave one out technique as well as by the calculation of statistical parameters for the established theoretical models. High agreement between experimental and predicted inhibitory values, obtained in the validation procedure, indicated the good quality of the derived QSAR models.
AtıfScopus3OpenAlex3İncele - MakaleYalnız künye2019Scopus SJRQ3Response surface methodology as optimization strategy for asymmetric bioreduction of acetophenone using whole cell of Lactobacillus senmaizukei
Çolak, Nida Sezin; Şahin, Engin; Dertli, Enes; Yilmaz, Mustafa Tahsin; Taylan, Osman
Whole cell applications are one of the main methodologies for the bioreduction of prochiral ketones to obtain enantiomerically rich chiral secondary alcohols which are mainly affected by the culture parameters of the whole cell. In this study, whole cell of Lactobacillus senmaizukei as a safe Lactic Acid Bacteria (LAB) was used for the reduction of acetophenone and Response Surface Methodology (RSM) application was used to optimize the culture parameters in terms of temperature, pH, incubation time, and agitation level to obtain the highest enantiomeric excess (ee) and conversion rate. The predicted optimum conditions for the bioreduction with whole cell Lactobacillus senmaizukei were found to be pH of 5.25, temperature of 25 °C, incubation time of 72 hr, and agitation level of 100 rpm. Importantly, the efficiency of the reduction of the acetophenone was significantly affected by the linear and quadratic effects of culture parameters. These findings are important to show the role of culture parameters for the bioreduction reactions and also the efficiency of the RSM technique to optimize these parameters.
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