Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(114)
- Kaya, Yunus(48)
- Şahin, Engin(48)
- İspirli, Hümeyra(47)
- Özen, Soner(38)
- Şenay, Volkan(37)
- Pat, Suat(36)
- Kutlu, Naciye(32)
- Artar, Musa(31)
- Can, Zehra(31)
- Korkmaz, Şadan(31)
- Yilmaz, Mustafa Tahsin(31)
- Öner, Erdal(31)
- Bayram, Sinan(30)
- Cuce, Erdem(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Ecem Bayram, Nesrin(28)
- Mercan, Emin(28)
- Ayata, Ümit(27)
- Bayraktar, Bülent(27)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Ayazoglu, Rabil(22)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Bayram, Ozkan(21)
- Kamiloğlu, Aybike(21)
- Dirican, Ebubekir(20)
- Kadakal, Mahir(20)
- Abdioglu, Murat(19)
- Birinci, Ahmet(19)
- Tozlu, Alperen(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Cinar, Mehmet(17)
- Gul, Volkan(16)
- Hasar, Ugur C.(16)
- Kadakal, Huriye(16)
- Kara, Yakup(16)
Yayınlar
- MakaleAçık Erişim2013Scopus SJRQ1Solutions of an anisotropic nonlocal problem involving variable exponent
Avci, Mustafa; Ayazoglu, Rabil A.; Cekic, Bilal
The present paper deals with an anisotropic Kirchhoff problem under homogeneous Dirichlet boundary conditions, set in a bounded smooth domain Ω of ℝN (N ≥ 3). The problem studied is a stationary version of the original Kirchhoff equation, involving the anisotropic p→(.)-Laplacian operator, in the framework of the variable exponent Lebesgue and Sobolev spaces. The question of the existence of weak solutions is treated. Applying the Mountain Pass Theorem of Ambrosetti and Rabinowitz, the existence of a nontrivial weak solution is obtained in the anisotropic variable exponent Sobolev space W01p→(.) (Ω), provided that the positive parameter λ that multiplies the nonlinearity f is small enough.
AtıfScopus13WoS14OpenAlex9
İncele - MakaleYalnız künye2013Scopus SJRQ1An experimental exergetic comparison of four different heat pump systems working at same conditions: As air to air, air to water, water to water and water to air
Çakir, Uǧur; Çomakli, Kemal; Çomakli, Ömer; Karsli, Süleyman
In this study, we designed a multifunctional heat pump system using just one scroll compressor and which can be run in four different modes, namely air to air, air to water, water to water and water to air, in order to make an experimental energetic and exergetic performance comparison. Experimental system consists of two condensers and two evaporators and uses R22 as working fluid. One of the evaporators and condensers uses water and the others use air as heat source/sink. Heating capacities of four heat pump types are equal to each other. It is realized by adjusting the mass flow rate and temperature level of external fluid of condenser. Results show that the heat pump unit which has the maximum COP (coefficient of performance) value is water to air type with 3.94 and followed by water to water type with 3.73, air to air type with 3.54 and air to water type with 3.40. Ranking of four heat pump types with respect to their mean exergy efficiency is as follows; water to air type with 30.23%, air to air type with 30.22%, air to water type with 24.77% and water to water type with 24.01%. Exergy destruction rates of the systems were investigated in this study and the results revealed that the heat pump type which has the maximum exergy destruction is air to air type with 2.93kW. The second highest one is air to water type with 2.84kW. The third highest one is water to air type with 2.64kW and last one is water to water type with 2.55kW. It is understood that the temperature of the evaporator external fluid affects the exergetic efficiency of the system more than the mass flow rate. In contrast to the previous, the dominant parameter which has more important effect on the exergy destruction of the heat pump unit is the mass flow rate of evaporator external fluid.
AtıfScopus55WoS46İncele - MakaleYalnız künye2013Scopus SJRQ2Analysis of trusses by total potential optimization method coupled with harmony search
Toklu, Yusuf Cengiz; Bekdaş, Gebrail; Temur, Rasim
Current methods of analysis of trusses depend on matrix formulations based on equilibrium equations which are in fact derived from energy principles, and compatibility conditions. Recently it has been shown that the minimum energy principle, by itself, in its pure and unmodified form, can well be exploited to analyze structures when coupled with an optimization algorithm, specifically with a meta-heuristic algorithm. The resulting technique that can be called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) has already been applied to analyses of linear and nonlinear plane trusses successfully as coupled with simulated annealing and local search algorithms. In this study the technique is applied to both 2-dimensional and 3-dimensional trusses emphasizing robustness, reliability and accuracy. The trials have shown that the technique is robust in two senses: all runs result in answers, and all answers are acceptable as to the reliability and accuracy within the prescribed limits. It has also been shown that Harmony Search presents itself as an appropriate algorithm for the purpose.
AtıfScopus33WoS26OpenAlex26İncele - MakaleAçık Erişim2013Scopus SJRQ3Existence of solutions for an elliptic equation with nonstandard growth
Avci, M.; Mashiyev, R. Ayazoglu; Cekic, B.
This paper deals with the existence of solutions for some elliptic equations with nonstandard growth under zero Dirichlet boundary condition. Using a direct variational method and the theory of the variable exponent Sobolev spaces, we set some conditions that ensures the existence of nontrivial weak solutions.
AtıfScopus2OpenAlex2İncele - 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 - MakaleYalnız künye2013Scopus SJRQ3Selective Separation, Preconcentration, and Determination of Au (III) Ions in Environmental Samples by Coprecipitation With a 1,2,4-Triazole Derivative
Ozdes, Duygu; Duran, Celal; Serencam, Huseyin; Şahin, Deniz
An effective, simple, lowcost, and accurate separation and preconcentration procedure which has minimal impact on the environment has been developed. It is based on the carrier element-free coprecipitation (CEFC) of Au(III)ions using N-benzyl-2-{[3-methyl-4-(2morpholine-4-ylethyl)-5-oxo-4,5-dihydro-1H-1,2, 4-triazole-1-yl] acetyl)hydrazinecarboxamide (BODAH) as an organic coprecipitant. Determination of the Au(IH) ion levels was performed by flame atomic absorption spectrometry (FAAS). The developed method provided a detection limit of 0.36 μg L-1 and the relative standard deviation for Au(III)ions was found to be 5.1%. Spike tests and certified reference material analyses were performed to validate the method. The developed method was systematically investigated in different sets of experimental parameters that influence the quantitative recovery of the Au(III)ions. Based on these investigations, the optimum conditions for the determination of Au(III) ions at trace levels were established. The coprecipitation method was applied to anodic slime, gold ore, soil, and water samples to determine their Au(III)levels.
AtıfScopus6İncele - MakaleAçık Erişim2013Scopus SJRQ1Damages on reinforced concrete buildings due to consecutive earthquakes in Van
Ates, Sevket; Kahya, Volkan; Yurdakul, Muhammet; Adanur, Suleyman
Consecutive earthquakes occurred on October 23rd, 2011 in Ercis and on November 9th, 2011 in Edremit that are townships located 90. km and 18. km far from Van city in Turkey, respectively. A total of 28,000 buildings were damaged or collapsed in the city center and the surrounding villages after the Ercis earthquake. This number reached 35,000 after the Edremit earthquake. In the area where the earthquakes occurred, almost all the reinforced concrete buildings were affected.This study presents field observations of damages on reinforced concrete buildings due to the consecutive earthquakes that occurred in Van, Turkey. Damages appearing in the buildings may occur due to several reasons such as site effect, poor construction quality, poor concrete strength, poor detailing in beam-column joints, detailing of stronger beam than column, soft stories, weak stories, inadequate reinforcement, short lap splices, incorrect end hook angle, and short columns. Aftershocks also caused progressive damages on the buildings within 17 days after the earthquakes. According to the results of this study, most of the damaged buildings were not designed and constructed according to the Turkish earthquake code, the so-called Specification for Buildings to be built in Seismic Zones.
AtıfScopus84WoS74OpenAlex92İncele - MakaleYalnız künye2013Scopus SJRQ2Synthesis, conformational and spectroscopic characterization of monomeric styrene derivatives having pendant p-substituted benzylic ether groups
Cinar, Mehmet; Ozcan, Levent; Karabacak, Mehmet; Erol, Ibrahim
Three derivatives of styrene monomer, 4-chlorophenyl-4-vinylbenzyl ether (I), 4-methoxyphenyl-4-vinylbenzyl ether (II) and 4-ethylphenyl-4-vinylbenzyl ether (III) were synthesized. The synthesized two novel compounds (I and III) and one with undefined structural features were identified by experimental spectroscopic techniques and density functional approach. The optimized geometrical structure, vibrational and electronic transitions along with chemical shifts of those compounds were presented in this study. The vibrational spectra of investigated compounds were recorded in solid state with FT-IR spectrometry in the range of 4000-400 cm-1. The computational vibrational wavenumbers and also ground state equilibrium conformations were carried out by using density functional method with 6-311++G(d,p) basis set. Assignments of the fundamental vibrational modes were examined on the basis of the measured data and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. Isotropic chemical shift of hydrogen and carbon nuclei were investigated via observed 1H and 13C NMR spectra in deuterated DMSO solution and predicted data applied with gauge-invariant atomic orbitals (GIAOs) method. The UV absorption spectra of monomers were observed in the range of 200-800 nm in ethanol, and time dependent DFT method was used to obtain the electronic properties. A detailed description of spectroscopic behaviors of compound was given based on the comparison of experimental measurements and theoretical computations.
AtıfScopus1WoS1OpenAlex1
İncele - MakaleYalnız künye2013Scopus SJRQ3The effects of reading-writing-application technique and learning together technique on increasing 6th grade students' academic achievement and students' opinions about these techniques
Aksoy, Gokhan; Gurbuz, Fatih
The aim of this study is to identify the effects of Reading-Writing-Application technique, Learning Together technique and Traditional Teaching methods on increasing students' academic achievements in the unit "particular structure of matter" at the science and technology course. In addition, students' written opinions were received from students (RWAG and LTG) about Reading-Writing-Application and Learning Together techniques. This study included 92 students from three different classes at the 6 th grade of a primary school during the 2010-2011 academic year. One of these classes served as the Reading-Writing-Application Group (RWAG), using group Reading-Writing-Application Technique, the second one served as the Learning Together Group (LTG), using the Learning Together technique, and the last one served as the Traditional Teaching Group (TTG), using the Traditional Teaching methods. The main instruments for obtaining data were the Academic Achievement Test (AAT) and Students' Written Opinions (SWO). Academic Achievement Test was applied to the all treatments groups but Students' Written Opinions was only applied RWAG and LTG. The data obtained on instruments were evaluated by using descriptive statistic, one-way variance analysis ANOVA and content analysis according to qualitative approach. It was concluded from the research results that the teaching of the unit "particular structure of matter" via the Reading-Writing-Application technique was more effective in increasing students' academic achievements compared to Learning Together technique and the Traditional Teaching methods. In addition, the written opinions of RWAG students and LTG students showed that the students have some negative opinions about Cooperative Learning Method.
AtıfScopus2İncele - MakaleAçık Erişim2013Scopus SJRQ1Structure and biosynthesis of two exopolysaccharides produced by lactobacillus johnsonii FI9785
Dertli, Enes; Colquhoun, Ian J.; Gunning, A. Patrick; Bongaerts, Roy J.; Le Gall, Gwénaëlle; Bonev, Boyan B.; Mayer, Melinda J.; Narbad, Arjan
Exopolysaccharides were isolated and purified from Lactobacillus johnsonii FI9785, which has previously been shown to act as a competitive exclusion agent to control Clostridium perfringens in poultry. Structural analysis by NMR spectroscopy revealed that L. johnsonii FI9785 can produce two types of exopolysaccharide: EPS-1 is a branched dextran with the unusual feature that every backbone residue is substituted with a 2-linked glucose unit, and EPS-2 was shown to have a repeating unit with the following structure: -6)-α-Glcp-(1-3)-β-Glcp-(1-5)-β-Galf-(1-6)-α-Glcp-(1-4) -β-Gal p-(1-4)-β-Glcp-(1-. Sites on both polysaccharides were partially occupied by substituent groups: 1-phosphoglycerol and O-acetyl groups in EPS-1 and a single O-acetyl group in EPS-2. Analysis of a deletion mutant (δepsE) lacking the putative priming glycosyltransferase gene located within a predicted eps gene cluster revealed that the mutant could produce EPS-1 but not EPS-2, indicating that epsE is essential for the biosynthesis of EPS-2. Atomic force microscopy confirmed the localization of galactose residues on the exterior of wild type cells and their absence in the δepsE mutant. EPS2 was found to adopt a random coil structural conformation. Deletion of the entire 14-kb eps cluster resulted in an acapsular mutant phenotype that was not able to produce either EPS-2 or EPS-1. Alterations in the cell surface properties of the EPS-specific mutants were demonstrated by differences in binding of an anti-wild type L. johnsonii antibody. These findings provide insights into the biosynthesis and structures of novel exopolysaccharides produced by L. johnsonii FI9785, which are likely to play an important role in biofilm formation, protection against harsh environment of the gut, and colonization of the host.
AtıfScopus131WoS120OpenAlex134İncele - MakaleAçık Erişim2013Scopus SJRQ2Experimental research of dynamic instabilities in the presence of coiled wire inserts on two-phase flow
Omeroglu, Gokhan; Comakli, Omer; Karagoz, Sendogan; Sahin, Bayram
The aim of this study is to experimentally investigate the effect of the coiled wire insertions on dynamic instabilities and to compare the results with the smooth tube for forced convection boiling. The experiments were conducted in a circular tube, and water was used as the working fluid. Two different pitch ratios (H / D = 2.77 and 5.55) of coiled wire with circular cross-sections were utilised. The constant heat flux boundary condition was applied to the outer side of the test tube, and the constant exit restriction was used at the tube outlet. The mass flow rate changed from 110 to 20 g/s in order to obtain a detailed idea about the density wave and pressure drop oscillations, and the range of the inlet temperature was 15-35°C. The changes in pressure drop, inlet temperature, amplitude, and the period with mass flow rate are presented. For each configuration, it is seen that density wave and pressure drop oscillations occur at all inlet temperatures. Analyses show that the decrease in the mass flow rate and inlet temperature causes the amplitude and the period of the density wave and the pressure drop oscillations to decrease separately.
AtıfScopus2WoS1OpenAlex4İncele - MakaleYalnız künye2013Scopus SJRQ2Determination of conformational and spectroscopic features of ethyl trans-alfa-cyano-3-indole-acrylate compound: An experimental and quantum chemical study
Cinar, Mehmet; Karabacak, Mehmet
The optimized geometrical structure, vibrational and electronic transitions, chemical shifts and non-linear optical properties of ethyl trans-alfa-cyano-3-indole-acrylate (C14H12N 2O2) compound were presented in this study. The ground state geometrical structure and vibrational wavenumbers were carried out by using density functional (DFT/B3LYP) method with 6-311++G(d,p) as basis set. The vibrational spectra of title compound were recorded in solid state with FT-IR and FT-Raman in the range of 4000-400 cm-1 and 4000-10 cm -1, respectively. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The 1H, 13C and DEPT NMR spectra were recorded in DMSO solution, and gauge-invariant atomic orbitals (GIAO) method was used to predict the isotropic chemical shifts. The UV-Vis absorption spectra of the compound were recorded in the range of 200-800 nm in various solvents of different polarity (acetone, benzene, chlorobenzene, chloroform, DMSO, ethanol, methanol and toluene). Solvent effects were calculated using TD-DFT and CIS method. To investigate the non-linear optical properties, the polarizability, anisotropy of polarizability and molecular first hyperpolarizability were computed. A detailed description of spectroscopic behaviors of compound was given based on the comparison of experimental measurements and theoretical computations.
AtıfScopus12WoS11İncele - MakaleAçık Erişim2013Scopus SJRQ2An experimental and theoretical investigation of Acenaphthene-5-boronic acid: Conformational study, NBO and NLO analysis, molecular structure and FT-IR, FT-Raman, NMR and UV spectra
Karabacak, Mehmet; Sinha, Leena; Prasad, Onkar; Asiri, Abdullah M.; Cinar, Mehmet
The solid state Fourier transform infrared (FT-IR) and FT-Raman spectra of Acenaphthene-5-boronic acid (AN-5-BA), have been recorded in the range 4000-400 cm1 and 4000-10 cm 1, respectively. Density functional theory (DFT), with the B3LYP functional was used for the optimization of the ground state geometry and simulation of the infrared and Raman spectra of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes and the normal modes were assigned by a scaled quantum mechanical (SQM) force field approach. Hydrogen-bonded dimer of AN-5-BA, optimized by counterpoise correction, has also been studied by B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H·O hydrogen bonding have been discussed. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by Gauge-Including Atomic Orbital (GIAO) method. Natural bond orbital (NBO) analysis has been applied to study stability of the molecule arising from charge delocalization. UV spectrum of the title compound was also recorded and the electronic properties, such as frontier orbitals, and band gap energies were measured by TD-DFT approach. The first order hyperpolarizability (β), its components and associated properties such as average polarizability and anisotropy of the polarizability (α and Δα) of AN-5-BA was calculated using the finite-field approach.
AtıfScopus38WoS36OpenAlex33İncele - MakaleAçık Erişim2012The Qur'an Exegesis Culture Andalusia
Sentürk, Mustafa
this article, that we aim to examine the Qur'an exegesis culture in Andalusia, we want to handle the perception of Qur'an exegesis by searching answers for the following questions in general terms: How and when the Qur'an exegesis started in Andalusia? Who were the pioneers of the exegesis in Andalusia? What were the references of the exegesis in Andalusia? Which tafsirs were the exegesis in the region referring to? What was the methodology of exegesis in the region? Which procedure were commentators interested in among the assorted commentary drifts? What were the characteristics of interpretation in the region? Was there any difference in understanding of the Qur'an exegesis in Andalusia by comparison with other Islamic regions? If it was so, what were they? And finally, could Andalus create a school in tafsir in every respect?
AtıfWoS1OpenAlex8İncele - MakaleAçık Erişim2012Mediation in Islamic Jurisprudence
Sen, Yusuf
The conflict resolution is the most fundamental matter that is all legal systems must carry out. People who have problems between themselves find solutions to their issues through the reconcilation, the mediation, the peace/sulh, the arbitration/consolidation and the court of law. In this paper mediation is pointed out as one of the methods of the conflict resolution. Concept analysis regarding to the meditaon is being made and also the comparision between sulh/peace and other conflict resolution methods are being done. In order to provide adequate ground for the mediation, the Quran and the prophet's practices are examined. Morever, the application of the mediation in the contemprary world is discussed. The procces of the mediation and the qualifications that are asked from the mediator are explained. The paper is ended at the conclusion part with the thoughts and the considerations.
AtıfWoS2OpenAlex16İncele - MakaleYalnız künye2012Scopus SJRQ4Expression of cytosolic and noncytosolic carbonic anhydrase enzymes from bovine brain membrane
Demir, Nazan; Demir, Yasar; Coskun, Fatma; Tasgin, Esen
Carbonic anhydrase is an enzyme that takes responsibility in inhalation function but, until today, carbonic anhydrase is not examined if it is present in the bovine brain membrane or not. The enzyme carbonic anhydrase was purified and separately characterized according to the bonding forms in 4 steps such as outer peripheral, cytosolic, inner peripheral and integral. Affinity chromatography was used for purification of the enzyme in all four steps. The affinity column was prepared with sepharose-4B-L-tyrosine-sulphanilamide. Purified carbonic anhydrase was obtained at each step. Enzyme activity was measured by CO2 hydratase activity and esterase activity methods. Optimum pH and optimum temperature were defined for purified enzymes at each step. Morover molecular weight and purity were detected by gel filtration and SDS-PAGE electrophorose. In addition, the enzyme's Km and nmax values were found with the Lineweaver- Burk method. The obtained results are discussed in comparison with other mammalian carbonic anhydrases. Carbonic anhydrase was shown to be exist in bovine brain membrane and this enzyme was optimized.
AtıfScopus1İncele - MakaleYalnız künye2012Scopus SJRQ1Adsorption of phenol from aqueous solution on a low-cost activated carbon produced from tea industry waste: Equilibrium, kinetic, and thermodynamic study
Gundogdu, Ali; Duran, Celal; Senturk, H. Basri; Soylak, Mustafa; Ozdes, Duygu; Serencam, Huseyin; Imamoglu, Mustafa
The ability of activated carbon which was produced by chemical activation using zinc chloride from tea industry wastes (TIWAC) to adsorb phenol molecules from aqueous solution was tested by equilibrium, kinetic, and thermodynamic parameters. Phenol adsorption on TIWAC took place with a high yield at pH values in the range 4 to 8. The optimum contact period was observed as 4.0 h and from the adsorption graphs plotted as a function of time; it was established that phenol adsorption on TIWAC conformed more to a pseudosecond-order kinetic model. Additionally, it was determined that the adsorption rate is controlled by intraparticle diffusion as well as film diffusion. It was established that phenol adsorption on TIWAC can be better defined by the Langmuir adsorption model and its adsorption capacity was 142.9 mg·g-1 from the linear Langmuir equation. Temperature had an adverse effect on adsorption yield, and hence, the adsorption process was exothermic in our case. Moreover, increasing electrolyte concentration in the medium has a positive effect on adsorption yield. From the data obtained, it was concluded that the removal of phenol from aqueous solution by TIWAC produced from tea industry wastes with a very low cost took place with an extremely high performance.
AtıfScopus228WoS212OpenAlex222İncele - MakaleYalnız künye2012Scopus SJRQ2Forced convective two phase flow analysis in a circular tube equipped with twisted tapes
Omeroglu, Gokhan; Comakli, Omer; Karagoz, Sendogan; Manay, Eyuphan
In forced convection boiling systems, it is important to know the dynamic behavior for understanding and predicting the local and global stability of the system. Besides this, the instability phenomenon in the industrial processes in which two phase flow takes part becomes more of an issue. So, the mechanisms of instabilities and the ways of decreasing the stabilities are of interest of the researchers for a long time. In this study, the effects of pitch ratio, inlet temperature and the mass flow rate on two phase flow instabilities in a horizontal circular tube are investigated. The experiments are conducted under constant system pressure, and a constant heat input of 24 kW is applied to the outer surface of the circular test pipe having constant exit restriction. The results of two different pitch ratios are also compared with the smooth tube. For all investigated cases, the results are evaluated in terms of pressure drop type and density wave type oscillations. The time dependent measurements of top wall temperature, bottom wall temperature, inlet pressure and mass flow rate variations are also presented. The boundaries of the oscillations are found for both twisted tape and smooth channel. It is found that the unstable region of the flow extends while the distance between boundaries increases. It is observed that the system is more stable in the case of the lowest pitch ratio, and the increase of the pitch ratio causes system to be less stable. By the decrease of the inlet temperature, the single phase liquid region extends in the test tube and thus the system becomes more stable.
- MakaleYalnız künye2012Scopus SJRQ3The prediction of heat transfer and fluid characteristics for equilateral triangular bodies in tandem arrangement by artificial neural networks
Manay, Eyüphan; Güneş, Sibel; Akçadirci, Esra; Özceyhan, Veysel; Çakir, Ǔur; Çomakli, Ömer
The objective of this study is to investigate the effect of the spacing between equilateral dual triangular bodies symmetrically placed into the channel axis under steady state conditions on heat transfer and fluid characteristics by using artificial neural networks (ANN). The Back Propagation (BP) training algorithm was applied to train the model. The successful application proved that ANN model can be used for predicting the Nusselt number and skin friction coefficient as a convenient and effective method. The distribution of local Nusselt number, skin friction coefficient along the channel wall and overall enhancement ratio of all investigated cases are presented.
AtıfScopus5İncele - MakaleYalnız künye2012Scopus SJRQ1Determination of the effect of volcanic pumice replacement on macro void development for blended cement mortars by computerized tomography
Tekin, Ilker; Birgul, Recep; Aruntas, Huseyin Yilmaz
In this study, the effect of volcanic pumice replacements with different ratios on the macro void development was observed using CT for a period of 100 days. The cured mortar specimens were imaged by X-ray CT on different days of the experiment. Utilizing Hounsfield Unit values as guides, void volumes and ratios were identified and measured by Matlab software. SEM images supported the X-ray CT results. It is shown that X-ray CT analysis is capable of assessing the development of macro voids in the mortar specimens.
AtıfScopus22WoS21OpenAlex20İncele