Yayınlar
Koleksiyondaki öğeler
- BildiriAçık Erişim2015Scopus SJRQ3Investigation of an alternative fuel for diesel engines
Keven, A.; Karaali, R.
Internal combustion engines use generally fossil fuel products. World resources of it is limited. Renewable alternative energy sources are getting important solution for energy demand. Hazelnut oil ethyl ester is obtained from raw hazelnut and mixed with diesel oil in certain proportions to use in a four-stroke direct injected single cylinder diesel engine. In this study the effects of the mixture of diesel oil with hazelnut oil ethyl ester on the engine performance and exhaust gas emissions are investigated for the first time in literature. The fuel injection system is regulated to use the mixture in the engine for the investigation. The results show that, the mixture with 25% ethyl ester extracted from hazelnut oil can be used as an alternative fuel without any change or regulation of the diesel engine.
AtıfScopus7WoS3OpenAlex7
İncele - MakaleYalnız künye2015Scopus SJRQ1Effect of equal-channel angular pressing on room temperature superplasticity of quasi-single phase Zn-0.3Al alloy
Demirtas, M.; Purcek, G.; Yanar, H.; Zhang, Z.J.; Zhang, Z.F.
Quasi-single phase (dilute) Zn-0.3Al alloy was subjected to severe plastic deformation via equal-channel angular extrusion/pressing (ECAE/P), and the effects of ECAP on its room temperature (RT) and high strain rate (HSR) superplasticity and deformation mechanism were investigated. Multi-pass ECAP may refine the coarse-grained microstructure into the fine grained (FG) one. The grain size of Zn-matrix phase decreased down to 2.0m after ECAP. Many spherical Al-rich precipitates decomposed and homogeneously distributed inside the matrix phase. They are ultrafine grained (UFG) α-particles with the grain sizes ranging from 50nm to ~200nm. This special microstructure having FG and UFG micro-constituents brought about an improvement in RT superplasticity even at HSRs. While multi-pass ECAP decreased flow stress of the alloy, its elongation to failure increased substantially depending on the initial strain rates. The maximum elongation was 1000% at a low strain rate of 10-4s-1, and 350% elongation was achieved at a high strain rate of 10-2s-1. Grain boundary sliding (GBS) was found to be the main deformation mechanism in region-II as the optimum superplastic region.
AtıfScopus60WoS59OpenAlex55İncele - MakaleAçık Erişim2019Scopus SJRQ3Cognitive analysis of constructing algebraic proof processes: A mixed method research *
Öztürk, Mesut; Kaplan, Abdullah
This study aimed in order to investigate cognitive aspects of the processes of constructing algebraic proofs of pre-service and service secondary math teachers. We used explanatory sequential design from mixed research methods in the study. Secondary math teachers working in the province east of Turkey and pre-service secondary math teacher in this province participated to the study. Quantitative data of the study were collected through a “Proving Diagnostic Test” and qualitative data were gathered from the participants through a think aloud protocol. We used two different activity cards that each of them included one algebraic proof question in the think aloud protocol. Quantitative data were analyzed using descriptive and inferential statistics. Content analysis was applied to qualitative data. The study show that the cognitive skills performed by pre-service and service secondary math teachers emerge five categories: read the proposition of the proof, evaluating the correctness, determining strategies, carry out plans and heuristic shortcuts thinking strategy. Eight categories were identified in the theme (context of) of meta-cognitive skills. These categories are: facilitating the operations, questioning, awareness, planning, strategy determination, controlling, correlating, and analogical reasoning.
AtıfScopus9WoS3OpenAlex18TR Dizin2
İncele - MakaleYalnız künye2018Scopus SJRQ3Melissopalynological analysis for geographical marking of Kars honey; [Kars balının coğrafi İşaretlemesi İçin melissopalinolojik analiz]
Çelemli, Ömür Gençay; Özenirler, Çiğdem; Bayram, Nesrin Ecem; Zare, Golshan; Sorkun, Kadriye
In this research, the melissopalynological analysis of honey samples collected from Kars city located in the East Anatolian Region of Turkey was conducted for geographical marking. Within this context, melissopalynological analyses of 100 honey samples determined by sampling method were collected from eight districts of Kars in Eastern Anatolia Region of Turkey were done, to determine the nectarous source plants of Kars honey. As a result of melisopalynological analyses carried out in 100 honey samples; pollens of the taxa belonging to Apiaceae, Asteraceae, Berberidaceae, Betulaceae, Brassicaceae, Boraginaceae, Campanulaceae, Caryophyllaceae, Chenopodiaceae, Cistaceae, Cyperaceae, Dipsacaceae, Ericaceae, Fabaceae, Iridaceae, Lamiaceae, Liliaceae, Malvaceae, Onagraceae, Papaveraceae, Plantaginaceae, Poaceae, Polygonaceae, Ranunculaceae, Rhamnaceae, Rosaceae, Rubiaceae, Rutaceae, Salicaceae and Scrophulariaceae families were detected at different rates. Almost in all of the honey samples, Lotus corniculatus (in 99 samples), Onobrychis radiata (in 99 samples), Trifolium nigrescens (in 88 samples) from Fabaceae family and pollens of Echium vulgaris (81 samples) and Myosotis lithoospermifolia (15 samples) taxa from the Boraginaceae family, were found in honey samples. Onobrychis radiata pollen was the most intensely observed one among these samples (in dominant, secondary, minor, trace amounts). The total number of pollens (TPN-10) in 10 grams of honey were also detected during the melissopalynological analyses. TPN-10 values minimum: 226, maximum: 481157 and mean: 31678 were detected and the pollen abundance of the honeys are classified as good category. Kars is an important province for beekeeping with floral variety. As a result of this study, the first step of the geographical marking studies of Kars’ honey was completed.
AtıfScopus17İncele - MakaleAçık Erişim2015Scopus SJRQ3Writing and its use as a learning tool from teachers’ perspective: Instrument development and a pilot implementation; [Öğretmen Perspektifinden Yazma ve Yazmanın Öğrenme Amaçlı Kullanımı: Ölçme Envanteri Geliştirme ve Pilot Uygulama]
Ozturk, Bilge; Gunel, Murat
The aim of this study is to develop a measurement instrument to investigate science teachers’ perceptions toward writing and the use of writing as learning strategies in their learning environments. Aligned with the focus of the study, a Likert-type survey was developed through the previously developed international scale adaptation and literature review process. Using quantitative methodology and descriptive research method, the scale was implemented to 131 science teachers working at public schools in Erzurum, Turkey during 2011- 2012 school year. The data was analyzed through descriptive statistics for each item in the survey. The findings of the study revealed that science teachers perceive writing as a learning tool. Indeed, they believe that writing serves as a learning tool both for themselves and for their students. Further results revealed that teachers are aware of the significance of the writing in the development of students’ literacy skills. However, their in-class practices are limited in terms of implementing writing activities as a learning tool.
AtıfScopus2OpenAlex5İncele - MakaleYalnız künye2015Scopus SJRQ3Determination of antigenotoxic effects of four lichen species by using human lymphocytes
Anar, Mustafa; Asian, Ali; Ceker, Selcuk; Kizil, Hamit Emre; Alpsoy, Lokman; Agar, Guleray
In this study, the geno-toxic and antigeno-toxic properties of the total extracts of four lichen species were investigated by using human lymphocytes. We obtained total extracts from R farinacea, X. parietina, U. articulataand U. filipendula lichen species. The results of our studies showed that 5 μM concentrations of AFB1 changed the frequencies of micronucleus (MN) and malondialdehyde (MDA) levels, as well as superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx) activities. When 5,10 and 20 μg/ml concentrations of total extract were added to AFB1, the frequencies of MN and MDA levels were decreased, and SOD, GSH and GPx levels were increased. Consequently, our findings show that four lichen total extracts have strong antigenotoxic properties against aflatoxin Bi.
AtıfScopus3İncele - BildiriAçık Erişim2017Scopus SJRQ3Thermoeconomic analysis and assessment of Gaziantep municipal solid waste power plant
Tozlu, A.; Abuşoǧlu, A.; Özahi, E.
This paper presents a thermoeconomic analysis and assessment of a municipal solid waste power plant system in Gaziantep. The operation of an existing municipal solid waste power plant is described in detail and a thermoeconomical methodology based on exergoeconomic relations and specific exergy costing (SPECO) method is provided to allocate cost flows through subcomponents of the plant. SPECO method is based on a step by step procedure which begins from identification of energy and exergy values of all states defined in the present system through fuel (F) and product (P) approach and ends at the point of establishing related exergy based cost balance equations together with auxiliary equations. The actual exergy efficiency of the solid waste power plant is determined to be 47.84% which shows that 52.16% of the total exergy input to the plant is destroyed. The net electrical power output of the Gaziantep municipal solid waste power plant is 5.655 MW. The total cost rate of the power plant is evaluated as 18.44$/h as a result of thermoeconomic analyses.
AtıfScopus12WoS13OpenAlex16İncele - Derleme MakaleYalnız künye2016Scopus SJRQ1Vacuum glazing for highly insulating windows: Recent developments and future prospects
Cuce, Erdem; Cuce, Pinar Mert
A comprehensive review of vacuum glazing technology from state-of-the-art developments to future prospects has been presented. The review has been conducted in a thematic way in order to allow an easier comparison, discussion and evaluation of the findings. First, a thorough overview of historical development of vacuum glazing has been given. Then, numerous experimental, theoretical, numerical and simulation works on the scope have been evaluated and the characteristic results from the said works have been analyzed. Commercial vacuum glazing products in market have been assessed in terms of several performance parameters such as overall heat transfer coefficient, visible light transmittance, solar heat gain coefficient and cost. Techno-economic and environmental aspects of vacuum glazing technology have also been discussed. It can be concluded from the results that overall heat transfer coefficient of a vacuum glazing can be reduced up to 0.20 W/m2K through optimized integrations with low-e coatings. The incomparable U-value range of vacuum glazing enables significant mitigation in energy consumption levels and greenhouse gas emissions. Retrofitting 25.6 million homes in the UK with vacuum glazing can provide a carbon abatement of about 40 million tonnes a year, which is very promising.
AtıfScopus138WoS117OpenAlex148İncele - MakaleYalnız künye2016Scopus SJRQ1Effect of sugar beet fiber concentrations on rheological properties of meat emulsions and their correlation with texture profile analysis
Ağar, Berrin; Gençcelep, Hüseyin; Saricaoğlu, Furkan Türker; Turhan, Sadettin
The effect of sugar beet fiber (SBF) concentration on the rheological properties of meat emulsions was determined. In addition, texture profile analysis (TPA) of cooked meat emulsions was carried out to find a possible relationship between the dynamic rheological data and TPA parameters. All studied emulsions exhibited non-Newtonian, pseudoplastic behavior since apparent viscosity decreased with increasing shear rate. The Ostwald–de Waele model was successfully used to describe the flow properties of meat emulsions (R2 > 0.913). Emulsion systems were characterized as weak gel-like macromolecular dispersions with storage modulus (G′) much greater than loss modulus (G″). A modified Cox–Merz rule was applied by multiplying angular frequency with shift factors (αSF). Material stiffness parameter (Aα) calculated from complex modulus (G*) increased as SBF concentration increased. Significant correlations among the material stiffness data and TPA parameters were observed. It was concluded that TPA parameters could be predicted by using dynamic shear tests, and hence, this will make possible to save time and cost for meat processors when manufacturing a product with acceptable structural or textural characteristics.
AtıfScopus55WoS48OpenAlex66İncele - BildiriYalnız künye2016Investigation of the thickness effect to impedance analysis results AlGaN acoustic sensor
Özen, Soner; Bilgiç, Eyüp; Gülmez, Gülay; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Mohammadigharehbagh, Reza
In this study, AlGaN acoustic sensors were deposited on aluminum metal substrate by thermionic vacuum arc (TVA) method, for the first time. Impedance analyses of the fabricated acoustic sensors were investigated for the determining of effect of the nano layer thickness. Thickness values are very close to each others. Fabricated sensors have been fabricated from AlGaN deposited on aluminum substrates. Gallium materials are used in many applications for optoelectronic device and semiconductor technology. Thermionic vacuum arc is the deposition technology for the variously materials and applications field. TVA production parameters and some properties of the deposited layers were investigated. TVA is the fast deposition technology for the gallium compounds and doped gallium compounds. Obtained results that AlGaN layer are very promising material for an acoustic sensor but also TVA is proper fast technology for the production.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2017Scopus SJRQ2Mechanism of capsaicin inhibition of aldose reductase activity
Alim, Zuhal; Kilinc, Namık; Sengul, Bulent; Beydemir, Sukru
Aldose reductase (AR) inhibitors play a vital importance as a potential therapeutic and preventive medicine when it comes to hyperglycemia associated diabetic complications. Additionally, capsaicin is used as a food additive and a drug in a number of diverse clinical trials. The aim of this study is to determine the in vitro inhibition behavior of capsaicin on AR enzyme activity, which was obtained from different rat tissues (heart, kidney, liver, and brain). We showed that AR was inhibited by capsaicin in the micromolar range and noncompetitive manner in all of the tissues. Ki values of capsaicin were found to be 8.87, 264, 535, and 597, respectively, in heart AR, kidney AR, liver AR, and brain AR. In conclusion, capsaicin may be an effective molecule when used in low concentrations to prevent diabetic complications associated with the polyol pathway.
AtıfScopus21WoS19OpenAlex24
İncele - MakaleYalnız künye2018Scopus SJRQ1A new method for determination of dynamic stability of self-consolidating concrete: 3-Compartment sieve test
Gökçe, H. Süleyman; Andiç-Çakır, Özge
There are many standard test methods and applications to determine or estimate the workability of fresh concrete mixtures, most of them are focused on highly flowable concrete mixtures. Due to its high flowability, self-consolidating concrete (SCC) is much more vulnerable to segregation compared to conventional concrete mixtures. Thus, researchers have been working on adopting dynamic and static test methods for determination and improvement of segregation stability of those mixtures. In this study, the different segregation test methods presented in the literature were assessed and a novel method, i.e. 3-compartment sieve test, was introduced. The dynamic stability of fresh self-consolidating concrete mixtures was evaluated by the suggested test method after slump-flow and J-Ring tests. In conclusion, the developed new method is recommended for determination of segregation in SCC due to satisfactory concurrency of results with those of visual stability index test (0.67 ≤ R2 ≤ 0.90) and sieve segregation resistance test (0.83 ≤ R2 ≤ 0.90), respectively.
AtıfScopus23WoS19OpenAlex23İncele - MakaleAçık Erişim2017Scopus SJRQ2A new method for titania thin film production: Thermionic vacuum arc method
Şenay, Volkan; Özen, Soner; Pat, Suat; Geçici, Birol; Korkmaz, Şadan
In this research, transparent titania (TiO2) thin films were deposited on a glass microscope slide and on a flexible polyethylene terephthalate (PET) substrate under a high vacuum condition by means of the thermionic vacuum arc (TVA) method in a very short period of time (60 s). Optical properties and surface properties of the coated TiO2 surfaces are related to the structural changes of the coated layers due to ion energies and substrate effect. But obtained results are closely linked to literature values. Our analysis showed that the TVA method is an alternative method for low-temperature coatings and the produced films present important advantages for optical and industrial applications.
AtıfScopus7WoS6OpenAlex7İncele - BildiriYalnız künye2018Threshold effect on particle tracking algorithms
Yücel, Harun; Velu, Sabareesh K. P.
Automated particle tracking algorithms are widely used by soft matter physicists as a research tool to detect and construct the trajectories of micron-sized particles in ffuids. Analyzing these trajectories will uncover the physics of the investigated particles mainly on the type of motion they undergo making them suitable for potential applications. A plethora of methods has been proposed and used for detection and tracking. In this work, we examine the performance of two commonly used tracking algorithms in terms of threshold dependencies in digital video images. One of them is the centroid method (CM), a well-known and used algorithm and the other is radial symmetry method (RSM) which is recently proposed. Here, we generate the synthetic digital video images consisting of randomly placed multiple particles and compare the absolute errors on the particle detection by varying threshold values. Our results suggest that both algorithms show dependence on the threshold value and on comparison RSM algorithm performs better than the CM algorithm when the noise level is zero. Moreover, the measured absolute errors show a strong dependence on threshold values when noise levels are increased (up to 20) especially for the RSM algorithm.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2016Scopus SJRQ1Optical, morphological properties and surface energy of the transparent Li4Ti5O12 (LTO) thin film as anode material for secondary type batteries
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
LTO thin film was deposited for the first time on a glass microscope slide (MS) by RF magnetron sputtering technology. This method has been suitable for preparation of high-quality thin films. The surface properties of the produced film were determined by atomic force microscope (AFM). The surface of the produced film appeared smooth and homogeneous. LTO coated on MS had compact structure and low roughness. A UV-vis spectrophotometer was used to determine intensity of light passing through the samples. Thus, according to the results obtained the produced film was highly transparent. The refractive index of the LTO thin film was presented in a low MSE value by spectroscopic ellipsometry (SE) and it was about 1.5. The optical band gap (Eg) was determined by the Tauc method. The produced LTO thin film exhibited a wide band gap semiconductor property with a band gap energy of about 2.95 eV. Finally, the surface free energy of the LTO thin film was calculated from the contact angle measurements using the Lewis acid-base, OWRK/Fowkes, Wu and Zisman methods.
AtıfScopus24WoS23OpenAlex27İncele - MakaleAçık Erişim2016Scopus SJRQ1Effect of boron-containing additives on rheological properties of asphalt binder
Oruç, Şeref; Yılmaz, Bahadır; Sancak, Kemal
In this study, four novel boron-containing additives were synthesised chemically in the laboratory. The modification was performed by adding the additives, respectively, into asphalt at a certain amount by weight at the same temperature and mixing conditions. The modification mechanism and microstructure of the blends were characterised by Fourier transform infrared spectrometer and scanning electron microscopy. The variation in modified samples in comparison to base asphalt was investigated by performing the penetration, softening point, dynamic shear rheometer, amplitude–frequency–temperature sweeps and rotational viscosity tests. It was observed that the additives increased the softening point, rutting resistance, elastic properties and viscosity of asphalt. The additive synthesised with triazole borate ester octanol-sulphuric acid catalysts gave the most enhancements, relative to base asphalt.
AtıfScopus20WoS17OpenAlex22İncele - MakaleYalnız künye2018Scopus SJRQ3Real-time implementation of self-tuning regulator control technique for coupled tank industrial process system
Ayten, Kagan Koray; Dumlu, Ahmet; Kaleli, Aliriza
This article presents the self-tuning regulator control technique for a coupled tank liquid level system that often used in industry. An autoregressive with exogenous model has been used as the liquid process model with the self-tuning control implementation in order to track the desired tank level trajectories with disturbances and uncertainties of the system dynamics. The designed self-tuning controller has been sensitive to parameter variations of the nonlinear coupled tank system. The parameters of the proposed controller are periodically updated themselves during the process by means of online recursive least square method with the forgetting factor algorithm. In this way, the parameter variations and unwanted disturbances of the system are eliminated in real-time application. In order to demonstrate the efficiency of the self-tuning regulator control technique, the real-time studies have been executed. The obtained experimental results demonstrated that the proposed controller gives the better trajectory tracking performance and smaller magnitude in overshot and undershot than the designed classical proportional–integral and sliding mode controllers.
AtıfScopus11WoS5OpenAlex10İncele - MakaleYalnız künye2015Scopus SJRQ1Simple time-saving method for iron determination based on fluorescence quenching of an azaflavanon-3-ol compound
Başoʇlu, Aysel; Tosun, Gonca; Ocak, Miraç; Alp, Hakan; Yayli, Nurettin; Ocak, Ümmühan
A simple and time-saving spectrofluorometric method developed using an azaflavanon-3-ol compound was used for the determination of iron in various food samples. Nitric acid and hydrogen peroxide were used for digestion of samples in a closed microwave system. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs INCT-MPH-2). Measurements were carried out using a modified standard addition method. The standard addition graph was linear until 21.6 mg/L in the determination of iron(III). Detection and quantification limits were 0.81 and 2.4 mg/L, respectively. Satisfactory accuracy was obtained for spinach, dill, mint, purslane, rocket, red lentils, dry beans, and two iron medicinal tablets. High recoveries were found for streamwater samples fortified at three different concentrations. The method is simple, time-saving, cost-effective, and suitable for the determination of the iron content of foods.
AtıfScopus22WoS19OpenAlex21İncele - MakaleYalnız künye2013Scopus SJRQ2Separation and pre-concentration of palladium(II) from environmental and industrial samples by formation of a derivative of 1,2,4-triazole complex on Amberlite XAD-2010 resin
Serencam, Huseyin; Bulut, Volkan Numan; Tufekci, Mehmet; Gundogdu, Ali; Duran, Celal; Hamza, Sibel; Soylak, Mustafa
A simple separation/pre-concentration method was developed for extraction of Pd(II) in various environmental samples, based on its adsorption of 4-phenyl-5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazole-3-yl)thio]methyl}-4H-1,2,4-triazole-3-thyol (PPTTMET) complex on Amberlite XAD-2010 resin in a mini column. The ligand has high affinity for Pd(II) among many other metals that are taken into consideration. The flame atomic absorption spectrometry is employed to determine the concentration of Pd(II). The optimum working conditions which were determined are as follows: 0.05 mol L-1 HNO3 as working medium, 1.0 mol L-1 HCI in acetone as elution solvent, 0.75 mg of PPTTMET amount and 750 mL of sample volume. The system was independent from the flow rates between 3.1 and 23.1 mL min-1. The Pd(II) adsorption capacity of Amberlite XAD-2010 resin was found to be 12.8 mg g-1 and the enrichment factor was calculated as 375. The method was successfully applied for the determination of Pd(II) in motorway dust samples, anodic sludge, gold ore, industrial electronic waste materials and various water samples.
AtıfScopus17WoS15OpenAlex17İncele - Derleme MakaleYalnız künye2016Scopus SJRQ1Toward multi-functional PV glazing technologies in low/zero carbon buildings: Heat insulation solar glass - Latest developments and future prospects
Cuce, Erdem
Heat insulation solar glass (HISG) is a recently developed multi-functional photovoltaic (PV) glazing technology to mitigate energy consumption of buildings and to provide optimum thermal comfort conditions to occupants. In essence, HISG represents an improved transparent amorphous silicon (a-Si) PV module prepared with several optimized coatings and structures. HISG differs from conventional PV glazing products by having some characteristic features such as thermal insulation, sound absorption, self-cleaning and notable energy saving. In addition, HISG has a 100% UV blocking rate and remarkably low shading coefficient, which provides desired lighting related thermal comfort conditions for indoor environments. HISG is also competitive with conventional double glazed products in market in terms of fabrication cost. In this respect, it is highly expected that HISG has a strong potential to dominate the fenestration market in the near future. In this research, a comprehensive review of HISG technology is presented. Power generation, thermal insulation, energy saving, self-cleaning, acoustic and aesthetic features of HISG are evaluated in detail through the state-of-The-art literature survey. Existing research projects on the scope and future prospects are also addressed within the scope of this study.
AtıfScopus75WoS62OpenAlex84İncele
