Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(17)
- İspirli, Hümeyra(8)
- Bulut, Ayhan(7)
- Şahin, Engin(7)
- Esmer, Yusuf(6)
- Tekce, Emre(6)
- Yilmaz, Mustafa Tahsin(6)
- Alım, Bünyamin(5)
- Arslaner, Ayla(5)
- Battal, Fetullah(5)
- Bayraktar, B.(5)
- Sayyed, M.I.(5)
- Aksakal, Vecihi(4)
- Ayata, Ümit(4)
- Bayraktar, Bülent(4)
- Bayram, Ozkan(4)
- Bayram, Sinan(4)
- Ecem Bayram, Nesrin(4)
- Gerçek, Yusuf Can(4)
- Gıdık, Betül(4)
- Kaya, Metin(4)
- Mercan, Emin(4)
- Sever, Mehmet(4)
- Takma, Çiğdem(4)
- Taylan, Osman(4)
- Tekce, E.(4)
- Yilmaz, Fatih(4)
- Özdemir, Akın(4)
- Öztürk, Mesut(4)
- Akpolat, Hacer(3)
- Ayazoglu, Rabil(3)
- Birinci, Ahmet(3)
- Dayı, Özkan(3)
- Erbayrak, Engin(3)
- Eygu, Hakan(3)
- Göktaş, Bora(3)
- Gökçe, H.S.(3)
- Gülhan, Ünal(3)
- Güzel, Ferdi(3)
- Kara, Adnan(3)
Yayınlar
- MakaleAçık Erişim2020Scopus SJRQ2Effect of the addition of essential fatty acid mixture to the drinking water of the heat stress broilers on adipokine (Apelin, BDNF) response, histopathologic findings in liver and intestines, and some blood parameters
Bayraktar, Bülent; Tekce, Emre; Aksakal, Vecihi; Gül, Mehmet; Takma, Çiğdem; Bayraktar, Sevil; Bayraktar, Fatma Gülten; Eser, Gizem
The purpose of this study was to examine the effect of adding an essential fatty acid mixture (EOM; Eucalyptus globulus Labill, thymus vulgaris, Cymbopogon nardus, and Syzygium aromaticum) to the drinking water in the heat stress broilers on the adipokine (Apelin, BDNF) response, the histopathologic changes in liver and intestines, and some biochemical parameters. This study lasted for a total of 42days, including the physical exercise period (7days) and the fattening period (35days). A total of 400 Ross 308 male broilers (1-d-old) were randomly divided into 8 groups (50 animals per group), each of which was exposed to various conditions of temperature (C: 22°C and SC: 36°C) and treatment dose (C, 250, 500 and 750mL/1000 L). Each group was divided into 5 subgroups, each comprising 10 animals. In the stress-free groups, whereas the Apelin level linearly decreased, the BDNF level linearly increased. In histopathology, the liver tissue was found to be normal in all groups whereas the duodenum villi length was found to increase in the group of 750mL/1000 L. No statistically significant difference was found between the stressed groups and the non-stressed groups in terms of VLDL, Glucose, Total bilirubin, ALT, and TG (p >.05). While Apelin level increased in the stressed groups, the BDNF level increased in the group of 250mL/1000 L. In the histopathological examination, a small amount of coagulation necrosis was detected in hepatocyte, a diffuse hydropic degeneration was observed in hepatocytes, and finally a dilatation and hyperaemia were seen in sinusoid in the groups of EOM-500mL/1000 L and EOM-750 m/1000 L compared to the control group. Whereas there was no difference between the group of EOM-250mL/1000 L and the control group in terms of duodenum villa length, there was a significant decrease in other groups (p <.00). In conclusion, this study showed that adding 250mL/1000 L of EOM to the drinking water had a positive effect on the serum levels of Apelin and p-BDNF in the groups exposed to stress (p <.05).HIGHLIGHTS Heat stress results in serious annual economic losses in the poultry industry. Essential oil fatty mix acids have positive effects on poultry health. Apelin and BDNF may be a protective factor against deleterious consequences of chronic exposition to heat stress.
AtıfScopus12WoS9OpenAlex10
İncele - MakaleAçık Erişim2020Scopus SJRQ2Phy-X / PSD: Development of a user friendly online software for calculation of parameters relevant to radiation shielding and dosimetry
Şakar, Erdem; Özpolat, Özgür Fırat; Alım, Bünyamin; Sayyed, M.I.; Kurudirek, Murat
A user friendly online Photon Shielding and Dosimetry (PSD) software available at https://phy-x.net/PSD has been developed for calculation of parameters relevant to shielding and dosimetry. These parameters include linear and mass attenuation coefficients (LAC, MAC), half and tenth value layers (HVL, TVL), mean free path (MFP), effective atomic number and electron density (Zeff, Neff), effective conductivity (Ceff) energy absorption and exposure buildup factors (EABF, EBF). The software can generate data on shielding parameters in the continuous energy region (1 keV-100 GeV). Also, some well-known radioactive sources (22Na, 55Fe, 60Co, 109Cd, 131I, 133Ba, 137Cs, 152Eu and 241Am) along with their energies and some characteristic (K-shell) X-ray energies of Cu, Rb, Mo, Ag, Ba and Tb elements are available in the software and can be selected by the user. Thus, one can obtain the shielding parameters at photon energies available for the predefined energies. Moreover, another parameter relevant to shielding i.e. the fast neutron removal cross section (FNRCS) can be calculated for a compound or a mixture using this software. The software is freely available online after having registered to the Phy-X platform.
AtıfScopus2019WoS1977OpenAlex2133İncele - MakaleAçık Erişim2020Scopus SJRQ3Examination of the metaphors of classroom and social sciences teacher candidates related to the concept of direction
Kuzey, Memet; Değ Irmenci, Yavuz
The aim of this research is to demonstrate the perception of the direction concept of the prospective teachers in the departments of classroom education and social sciences education through metaphors. For this purpose, the research was conducted in 2018-2019 academic year with a total of 174 teacher candidates studying in social sciences teaching and elementary education departments of the faculty of education of a state university in Turkey. One of the approaches to qualitative research, the phenomenology (phenomenology) design, was used in the study. The views and thoughts of the working group on the concept examined "the concept of direction... like/is similar to because... "collected by interview form consisting of his statement. Content analysis technique was used in the analysis of data. According to the findings of the study, participants developed a total of 81 valid metaphors for the concept of direction. These metaphors have been collected under 11 different categories. As a result of the study, the most preferred metaphors for the direction concept of the participants were the words Sun, Pole Star, Road, Compass, book and clock.
- MakaleAçık Erişim2020Optimization of exopolysaccharide production of Lactobacillus brevis E25 using RSM and characterization
Ermis, Ertan; Poyraz, Ecem; Dertli, Enes; Yilmaz, Mustafa Tahsin
Response surface methodology was used to determine the exopolysaccharide production of Lactobacillus brevis E25. The effects of three variables, temperature (30, 36 and 42 °C), incubation time (18, 33 and 48 h) and initial pH of growth medium (4.5, 5.5, and 6.5) were studied. Under optimum growth conditions, the amount of exopolysaccharide derived from Lactobacillus brevis E25 ranged from 10 to 35 gL-1. The size of EPS molecules ranged from 105 to 107 Da. Infra red spectrum analysis showed characteristics absorption peaks indicating the presence of-OH, C=O and C-H groups. Furthermore, only glucose was detected as monosaccharide in exopolysaccharide structure, revealing that the structure of exopolysaccharide is a homopolymeric glucan type. Based on the differential scanning calorimeter thermograms, exopolysaccharide’s melting temperature was observed around 116 °C.
AtıfScopus18OpenAlex18
İncele - MakaleYalnız künye2020Scopus SJRQ4Production of enantiopure chiral aryl heteroaryl carbinols using whole‐cell Lactobacillus paracasei biotransformation
Şahin, Engin
Aryl and heteroaryl chiral carbinols are useful precursors in the synthesis of drugs. Lactobacillus paracasei BD87E6, which is obtained from a cereal based fermented beverage, was investigated as whole cell biocatalyst for the bioreduction of different ketones (including aromatic, hetero-aromatic and fused bicyclic ketone) into chiral carbinols, which can be used as a pharmaceutical intermediate. The study shows that bioreduction of aryl, heteroaryl and fused bicyclic ketone (1–5) to their corresponding chiral carbinols (1a–5a) in excellent enantioselectivity (>99%) with high yields. This study gave the first example for an enantiopure production of (S)-6-chlorochroman-4-ol (3a), which has many antioxidant activity, by a biological method. For asymmetric bioreduction of other prochiral ketones, these results open way to use of L. paracasei BD87E6 as biocatalysts. Also, the present process shows a hopeful and alternative green synthesis for the production of enantiopure carbinols in a mild, inexpensive and environmentally friendly process.
AtıfScopus21WoS18OpenAlex20İncele - MakaleYalnız künye2020Scopus SJRQ2Operational Matrix by Hermite Polynomials for Solving Nonlinear Riccati Differential Equations
Kosunalp, Hatice Yalman; G¨ulsu, Mustafa
This paper studies the potential to ensure a numerical solution of nonlinear Riccati differential equations with an effective method, namely operational matrix which is derived by Hermite polynomials with the sense of Caputo derivative. In order to solve the Riccati dif- ferential equations, the complete problem is simplified with the oper- ational matrix obtained. To achieve this goal, the proposed approach converts the fractional differential equations (FDEs) into a set of alge- braic equations. We then construct a matrix with the algebraic equa- tions and extra equations extracted from initial conditions. Therefore, we achieve the solution by solving these algebraic equations given in a matrix sense. In order to show the efficiency of the proposed idea, we show a number of illustrative examples in which the results confirm the applicability of the suggested approach.
AtıfScopus2İncele - Kitap BölümüYalnız künye2020The Relationship of financial development and export; the case of Turkey: A literature review
Sayar, Ramazan
During the global financial crisis in 2008, the world trade experienced a large and severe collapse. Between 2008 and 2009, world exports and exports in Turkey decreased by 16% and 22%, respectively. The recent research has shown that the slowdown in global demand and tight financing conditions are the main factors behind this drop in exports. Auboin (2009) has stated that the 10%-15% decline in international trade after the global financial crisis may be due to the decline in commercial finance. In addition, the decline in commercial finance is particularly important for developing countries that have many sectors dependent on external financing. This study examines the reasons of the decline in exports in the world especially in Turkey during global financial crisis and assesses whether the financing constraints have contributed to this collapse.This study considered as a literature review consists of theoretical framework of the relationship between export and export financing. In order to show whether there is an effect of financing in international trade, firstly, research on the financial models is included in the classical models of international trade that show the dependence of international trading companies to financing. Secondly it has been utilized studies that analyzing of empirical evaluations of the effects of the external trade firms' dependence on external financing.
- MakaleAçık Erişim2020Scopus SJRQ2A visual application for teaching pipe flow optimization in engineering curricula
Türkkan, Yusuf Alptekin; Eryılmaz Türkkan, Gökçen; Yılmaz, Hamid
The main purpose of this study is to investigate the importance of programming in the learning and understanding of water distribution networks. This paper presents the implementation of a programming language C# for applications for teaching water distribution networks calculations at both undergraduate and graduate levels. A user's guide is also prepared for the software which includes the theory of hydraulic and optimization calculations. There are many ways to design water distribution networks. Hardy Cross method is very often used for optimization of networks. Thus, Hardy Cross optimization method was preferred in this study. It is a perfect study to implement as an educational tool at undergraduate and graduate levels of education.
AtıfScopus12WoS10OpenAlex12İncele - MakaleYalnız künye2020Scopus SJRQ1Thin films derived from Zn(Al)O mixed metal oxides nanoparticles dispersed in polyethylene glycol: Structural, morphological and optical properties
El Hassani, Kaoutar; Bayram, Ozkan; Anouar, Abdellah; Mavi, Ahmet
In this study, Zn(Al)O thin films were produced using colloidal solution of Zn(Al)O nanoparticles dispersed in polyethylene glycol (PEG). Zn(Al)O mixed metal oxides were obtained by a simple pyrolysis of Zn–Al containing layered double hydroxide materials with different Al content. Survey of textural analysis of Zn(Al)O mixed oxides displayed characteristic peaks of ZnO structure. The calculated ratios of lattice parameters c/a were found to be 1.61 and 1.60 for 3-ZAO and 5-ZAO, respectively. The optical transmittance of the prepared thin films was not significantly affected by the increase in Al content; however, this increase changed the optical band gap from 3.27 eV to 3.33 eV. ZAO thin films, which are both cost-effective with good optical properties, have the potential to be an alternative to those used in many optical devices lately.
AtıfScopus4WoS3OpenAlex4İncele - MakaleAçık Erişim2020Scopus SJRQ3Teacher opinions about children's awareness of zero-waste and recycling in the pre-school education years
Bulut, Ayhan
The aim of this study is to encourage the development of pre-school teachers by raising their awareness about zero-waste and recycling activities. The need for this research is linked to the lack of prominence about the concept of zero-waste in pre-school programs in Turkey, and also the limited inclusion of opportunities for pre-school students to learn about recycling strategies. This research uses a qualitative design and adopts a case-study approach. The study group was purposefully sampled using criterion-sampling. Interviews were conducted with forty pre-school education teachers who volunteered to support the research, had at least five years experience, and had received training about zero-waste and recycling activities. The interviews with pre-school education teachers were conducted once and took approximately fifty minutes. Content analysis and descriptive analysis approaches were employed. The research findings were based on each interview question, and tables were created under five headings. Research findings indicate that most of the pre-school education teachers stated the children's awareness about zero-waste and recycling was insufficient during the pre-school education years. Teachers have stated that awareness about zero-waste and recycling can be enriched through the inclusion of specific content and the use of visual materials in pre-school education programs. Additionally, pre-school education teachers emphasized that using an educational game will make the learning process about zero-waste and recycling strategies more enjoyable and will also be the most suitable method in terms of the children's age and levels of development. On the other hand, teachers have stated that in order to raise children's awareness about zero-waste and recycling, there should be further studies conducted about how such awareness will contribute to the social and emotional development of children as well as studies about how children can learn-by-doing.
AtıfScopus17OpenAlex19İncele - MakaleYalnız künye2020Scopus SJRQ2Reading comprehension, Mathematics self-efficacy perception, and Mathematics attitude as correlates of students’ non-routine Mathematics problem-solving skills in Turkey
Öztürk, Mesut; Akkan, Yaşar; Kaplan, Abdullah
Literature that investigates the factors affecting problem-solving evaluates the cognitive and affective components, such as reading comprehension, metacognition, Mathematics anxiety, Mathematics attitude and Mathematics self-efficacy. Recently, studies have shown that Mathematics attitude and Mathematics self-efficacy as affective factors, and reading comprehension as a cognitive factor could play a crucial role in the problem-solving of middle school students. This study investigated the influence of reading comprehension skill, Mathematics self-efficacy perception and Mathematics attitude on non-routine Mathematics problem-solving skills. It is hypothesized that non-routine problem-solving skills are related to reading comprehension skills, Mathematics self-efficacy perception and Mathematics attitudes. To achieve this aim, a reading comprehension skill test, a Mathematics self-efficacy perception scale, a Mathematics attitude scale and a non-routine problem-solving skill test were applied. The instruments were completed by 362 middle school students. A correlation analysis was used to determine the relationship of variables on non-routine problem-solving skills, and the predictive effects of the predictor variables on non-routine Mathematics problem-solving skills were examined by hierarchical regression analysis. The analysis also showed that for middle-school students’ non-routine Mathematics problem-solving skills, all related factors–reading comprehension, Mathematics self-efficacy perception and Mathematics attitude were significant. Reading comprehension skills and Mathematics self-efficacy perception significantly predicted problem-solving skills, and both predictors explained a total of 22% of the total variance.
AtıfScopus55WoS30OpenAlex116İncele - MakaleAçık Erişim2020Scopus SJRQ2Experimental investigation of radiation shielding performances of some important AISI-coded stainless steels: Part I
Alım, Bünyamin; Şakar, E.; Baltakesmez, Ali; Han, İbrahim; Sayyed, M.I.; Demir, Lütfü
The investigation of radiation shielding performances of AISI-302, 304, 321 and 430 stainless steels which have wide range of application because of their superior mechanical properties, temperature and corrosion resistances was aimed in this study. In accordance with this purpose, photon-shielding parameters of these stainless steels were calculated both experimentally and theoretically. These parameters calculated are linear attenuation coefficient, mass attenuation coefficient, mean free path, half-value layer, quarter-value layer, tenth-value layer, total atomic cross-section, total electronic cross-section, effective atomic number, effective electron number and effective conductivity. They were experimentally measured at twenty-three different energies in the range 22 keV and 1333 keV. The photon energies were obtained from seven different radioactive sources (22Na, 60Co, 241Am, 109Cd, 137Cs, 152Eu and 133Ba). The Si(Li) and NaI(Tl) detectors were separately used taking into account of energy-efficient regions to counting process at narrow-beam transmission geometry. In addition, all these parameters were computed at the 15 keV‒15 MeV wide energy range, theoretically. In order to make a satisfying assessment about radiation shielding capabilities of AISI 302, 304, 321 and 430 alloys, all calculations were also made for ordinary, steel-scrap and steel-magnetite concretes (Fe-based steel concretes) that are most commonly used as shielding material in many nuclear applications. According to the results obtained, it was observed that the radiation shielding performances of AISI 300 austenitic stainless steel series with containing Ni are superior to that of both AISI 430 ferritic stainless steel and examined concretes.
AtıfScopus52WoS46OpenAlex57İncele - MakaleAçık Erişim2020Scopus SJRQ2Investigation of the solution for discontinuous contact problem between a functionally graded (FG) layer and homogeneous half-space
Öner, Erdal; Birinci, Ahmet
In this study, the discontinuous contact problem between a functionally graded (FG) layer, which is loaded symmetrically with point load P through a rigid block, and a homogeneous half-space was solved using the theory of elasticity and integral transform techniques. The shear modulus and density of the layer addressed in the problem vary with an exponential function along with its height. The half-space is homogeneous, and no binder exists on the contact surface containing the FG layer. In the solution, the body force of the FG layer was considered, whereas that of the homogeneous half-space was neglected. The Poisson’s ratios of both the FG layer and homogeneous half-space were assumed to remain constant. Additionally, all the surfaces addressed in the problem were assumed to be frictionless. Using the theory of elasticity and integral transform techniques, the discontinuous contact problem was reduced to two integral equations, wherein the contact stress under the rigid block and the slope of the separation, which occurred at the interface of the FG layer and homogeneous half-space, are unknown. These integral equations were solved numerically for the flat condition of the rigid block profile using the Gauss–Chebyshev integration formula. Consequently, the stress distributions, start–end points of the separation region, and separation displacements between the FG layer and homogeneous half-space were obtained for various dimensionless quantities.
AtıfScopus24WoS25OpenAlex23İncele - MakaleYalnız künye2020Scopus SJRQ2Recovery of unburned carbonaceous matter (UCM) from sugar mill bottom ash
Katircioglu-Bayel, Diler; Serencam, Hüseyin; Uçurum, Metin
Millions of tons of coal fly and bottom ash are produced each year in many countries including Turkey. Coal combustion which is the main source of energy in sugar mill and many other industries produce massive quantities of waste. The present study aims to separate the unburned carbonaceous matter (UCM) from the bottom ash of Bor, Nigde-Turkey sugar plant has been studied using the mechanical flotation technique. For this purpose, the performances of three classical oils were investigated and then chemical parameters such as sodium silicate (Na2SiO3), collector (fuel-oil) and frother (pine-oil) were systematically examined by using Yates’ statistical technique. A product with 41.58% combustible grade at 87.44% recovery was obtained at 0 g/t sodium silicate, 7464 g/t fuel-oil, 888 g/t pine-oil, 15% pulp density, 1200 rpm impeller speed and natural pH. The results obtained from the experiments indicated that it was possible to enrich the bottom ash by using conventional flotation.
- MakaleYalnız künye2020Scopus SJRQ1Comparison of phenol removal with ozonation in jet loop reactor and bubble column
Barlak, Melahat Semin; Degermenci, Nejdet; Cengiz, Ibrahim; Ucun Özel, Handan; Yildiz, Ergun
This study aimed to remove phenol with ozonation in a jet loop reactor (JLR) and a bubble column (BC). In the first stage of the study, the mass transfer properties of JLR were determined and superiority over BC reactors were shown, and in the second stage, these reactors were used in phenol removal studies. At the same conditions, the volumetric mass transfer coefficient of JLR was 0.540 min-1, while this value was determined as 0.246 min-1 in the BC reactor. In phenol removal, the effects of initial phenol concentration, ozone dosage and pH on phenol and chemical oxygen demand (COD) removal were determined for both JLR and BC. While the pseudo-first rate constant for phenol removal in JLR at 221 mg/min ozone dosage was 0.1756 min-1, this value was only calculated as 0.1157 min-1 in the BC reactor. As a result, it has been shown that JLRs can achieve higher ozone gas transfer with lower energy consumption and perform more effective phenol and COD removal than BC reactors, especially at low pH and high ozone dosages.
AtıfScopus40WoS36OpenAlex39İncele - MakaleYalnız künye2020Scopus SJRQ3A dynamic segregation test method for heavyweight concrete: Density variation method
Süleyman Gökçe, H.; Andiç-Çakir, Ö.
Several segregation evaluation methods have been developed for concrete; however, none of them have been specially focused on heavyweight concrete, which has more of a tendency toward segregation because of differences in density of paste matrix to heavy aggregate. Thus, for heavyweight concrete, the segregation may be determined by measuring the difference density in a vertical direction. In this study, a simple reliable method, i.e., the density variation method, that considers the variation in vertical layers of the concrete is modeled to assess dynamic segregation of heavyweight concrete. In addition, 35 heavyweight concrete mixtures with high consistency were designed with various mixing parameters, and the results were compared with the model findings. The suggested test method was also compared with a conventional method (column segregation test by wet-sieving), and an equivalent segregation limit was determined. A strong linear relation (R2: 0.86) was found between the density variation method and column segregation test, and a segregation coefficient limit for segregation of heavyweight concrete is recommended as 1.7 %.
AtıfScopus7WoS6OpenAlex6İncele - MakaleYalnız künye2020Scopus SJRQ3First green synthesis of (R)-2-methyl-1-phenylpropan-1-ol using whole-cell Lactobacillus paracasei BD101 biotransformation
Şahin, Engin
Green chemistry includes a novel process in the production of drugs precursors and biological active molecules using biocatalysts, so reducing the threats for human sanitary and ecological pollutions. Asymmetric bioreduction of prochiral ketones by biocatalysts is one of the best prevalent used methods in synthetic organic chemistry due to the production of enantiopure chiral carbinols. This study emphasizes the application biocatalyst L paracasei BD101 for enantioselective bioreduction of 2-methyl-1-phenylpropan-1-one ketone, which contain branched alkyl chain, to (R)-2-methyl-1-phenylpropan-1-ol ((R)-2) in high yields and excellent enantiomeric excess (>99%). The scale-up production was performed, and 4.61 g of (R)-2 in enantiopure form was synthesized. L paracasei BD101 was proved to be a substantial biocatalyst in asymmetric bioreduction of a ketone which contains a branched alkyl chain. There is not any work in the literature similar to our study. Hence, it is important to work on filling this gap. This study is the first example for an enantiopure synthesis of (R)-2 by a biocatalyst. The new green method was developed for bioreduction of bulky ketones, which contains a branched alkyl chain, and it approves the synthesis of novel chiral carbinols in an easy, cheap, and environmentally friendly condition using L paracasei BD101.
AtıfScopus10WoS9OpenAlex10İncele - MakaleAçık Erişim2020Investigation of Beam Width Shaping of a Ku-band Horn Antenna using a Diffractive Optic Element and an Electromagnetic Wave Absorber
Teber, Ahmet
The feasibility of beam-shaping of a Ku-Band horn as a transmitting (Tx) antenna by mounting two different versions of lenses which are kind of Fresnel Zone Plates (FZP) is studied. The designed and fabricated geometrical structures offer a simpler approach building Fresnel Zone Plates by using an electromagnetic wave absorber and diffractive optic material. The diffractive optic material, paraffin, forms a set of alternating open and opaque annular zones on a flat surface, based on the design principles of Fresnel Zone Plates. An electromagnetic wave absorber covers the top surface of the formed paraffin, but not including the grooves. Thereafter, the Fresnel Zone plates are suitably attached in front of the transmitter horn antenna, located in the far-field region of a receiving antenna. The half-power beam-widths for the horn antenna (unloaded) and with two types of lenses are investigated. The results indicate that Fresnel zone plate structures can play a role suppressing side lobes in H-plane so that the effective radiation is to be significantly concentrated.
AtıfScopus1OpenAlex2İncele - MakaleAçık Erişim2020THERMAL ANALYSIS OF LONGITUDINAL A POROUS FIN WITH TEMPERATURE-DEPENDENT INTERNAL HEAT GENERATION USING THE VARIATION OF PARAMETERS METHOD
Güngör, Osman; Arslantürk, Cihat
. The present study investigates the thermal performance of longitudinal a porous fin with temperature-dependent internal heat generation. The Darcy model is utilized to obtain the differential form of the governing equation that solves the nonlinear temperature distribution equation using the method of variation of parameters. Although this method is applied to solve both linear and nonlinear differential equations, there exist rare applications of this method to solve nonlinear heat transfer problems. In the present study, we applied the method to estimate the thermal analysis of the porous fin exposed to convection. The heat generation is assumed as a function of temperature. The effects of the convection parameter Nc, internal heat generation ε, porosity Sn and generation number G parameter on the dimensionless temperature distribution are discussed in detail. The accuracy of the variation of parameters method is verified through comparison with homotopy perturbation method and the Matlab bvp4c solver (NUM). The results have disclosed that the variation of parameters method can be used as a very effective and practical approach for further studies of the porous medium.
AtıfOpenAlex1İncele - MakaleYalnız künye2020Scopus SJRQ1Characterisation of physicochemical, microbiological, thermal, oxidation properties and fatty acid composition of butter produced from thermosonicated cream
Sert, Durmuş; Mercan, Emin
The effects of thermosonication of cream on physicochemical, microbiological, thermal, oxidation properties and fatty acid composition of butter were determined. Butter samples were produced from cream thermosonicated (TS) for 5, 10, or 15 min and from raw (R) and pasteurised (P) cream as controls. Thermosonication decreased moisture content, water activity, and pH of samples when compared with control groups. Mean particle size (D [3.2]) values of TS samples were lower than the R and P samples. Thermosonication improved spreadability compared with that of butter from pasteurised cream. Oxidative stability (induction time) of TS samples was lower than R, but higher than P. Two melting peaks were determined; in all samples, the Tonset of the first peak ranged from 11.39 to 11.93 °C, and the Tpeak was between 14.01 and 14.14 °C. Thermosonication significantly reduced total bacteria count and can improve spreadability, oxidative stability, and microbial safety of butter samples.
AtıfScopus27WoS22OpenAlex26İncele