Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Altuntas, Serkan(4)
- Cokorilo, O(2)
- Gürses, Ahmet(2)
- Karaca, Zeynep(2)
- Kaynak, Selahattin(2)
- Söyüt, Hakan(2)
- Tekin, Ilker(2)
- Yurdagül, Erman(2)
- Çakir, Uǧur(2)
- Çomakli, Kemal(2)
- Özkan, Esra(2)
- Şentürk, Mustafa(2)
- Abdioglu, M.(1)
- Agar, Guleray(1)
- Aksoy, Gokhan(1)
- Akçadirci, Esra(1)
- Alpsoy, Lokman(1)
- Altan, Burhanettin S.(1)
- Anar, Mustafa(1)
- Aruntas, Huseyin Yilmaz(1)
- Ayberkin, Doruk(1)
- Açikyildiz, Metin(1)
- Bakirci, Kadir(1)
- Balaydiin, Halis Türker(1)
- Baslar, Mehmet(1)
- Beydemir, Sükrü(1)
- Beydemir, Şkrü(1)
- Beydemir, Şükrü(1)
- Birgul, Recep(1)
- Birişçi, Salih(1)
- Bolat, S.(1)
- Buzkan, Kemal(1)
- Cansiz, Ahmet(1)
- Ceker, Selcuk(1)
- Ceyhun, Saltuk Buǧrahan(1)
- Comakli, Omer(1)
- Coskun, Fatma(1)
- Coşkun, Kerem(1)
- Demir, Nazan(1)
- Demir, Yasar(1)
Yayınlar
- 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.
AtıfScopus5
İncele - 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.
AtıfScopus22WoS21OpenAlex20
İncele - Derleme MakaleYalnız künye2012Scopus SJRQ1Developing an attitude scale towards using instructional technologies for pre-service teachers
Metin, Mustafa; Kaleli Yilmaz, Gül; Coşkun, Kerem; Birişçi, Salih
The aim of this study is to develop an attitude scale towards using instructional technologies (USIT) for preservice teachers. The research was carried out with 1235 pre-service teachers that 567(45.9%) were freshman; 401 (32.5%) were sophomore; 151 (12.2%) were junior and 116 (9.4%) were senior students at different universities in Turkey. The study consists of five parts including literature review, item pool, experts' opinions, administration of scale and computing the reliability and validity. While constituting the item pool, an interview was carried out with 15 pre-service teachers related to instructional technologies. Among from 55 items which are directly related with the subject of attitude or which are selected from the relevant interviews. 45 of them were edited by expert opinions the five point likert type. The draft scale was administered to 1235 pre-service teachers. As a result of factor analysis, the number of items was reduced to 37. After carring out factor analysis the Cronbach-Alpha internal integrity coefficient of the final version of the scale was found as 0.949. By computing the reliability of USIT, the scale was ready to be used.
AtıfScopus17İncele - MakaleAçık Erişim2012Scopus SJRQ3Changes in carbonic anhydrase activity and gene expression of Hsp70 in rainbow trout (Oncorhynchus mykiss) muscle after exposure to some metals
Söyüt, Hakan; Beydemir, Sükrü; Ceyhun, Saltuk Buǧrahan; Erdoǧan, Orhan; Kaya, Elif Duygu
The effects of some heavy metals Co(II), Cu(II), Zn(II), and Ag(I) on carbonic anhydrase (CA) activity from rainbow trout (RT) muscle were investigated. Moreover, the effects of these metals on the expression of heat shock protein 70 (Hsp70) gene in muscle tissue were examined by real-time quantitative PCR (RT-PCR) in muscle tissue aft er exposure to the metals at the end of 6, 12, 24, and 48 h. CA was purified with a specific activity of 2300 EU mg-1, a yield of 19%, and 1080-fold. The molecular weights (Mw) of subunit and native enzyme were approximately 30 and 31 kDa, respectively. Optimum pH, stable pH, optimum temperature, activation energy (Eα), activation enthalpy (ΔH), and Q10 (the difference in activity of enzyme caused by the increment of 10 oC) value were determined. Apparent Michaelis constant (Km), maximum reaction rate (Vmax), and turnover rate of the enzyme (Kcat) values were 1.29 mM, 0.17 μmol min-1, and 28.8 s-1, respectively. The catalytic efficiency (Kcat/Km) was 22.3. The heavy metals decreased in vitro CA activity. Inhibition mechanisms of the metal ions were noncompetitive, except for the Co(II) ion, which was competitive. The expression of the Hsp70 gene was increased in the presence of the metal ions. The expression level at the end of 48 h was the highest for all of the metals. Consequently, the in vitro inhibition rank order was determined as Co(II) > Zn(II) > Cu(II) > Ag(I). Interestingly, Ag(I) was the most effective metal ion on Hsp70 gene expression.
AtıfScopus9WoS8OpenAlex9İncele - MakaleYalnız künye2012Scopus SJRQ1Multi-criteria decision making methods based weighted SERVQUAL scales to measure perceived service quality in hospitals: A case study from Turkey
Altuntas, Serkan; Dereli, Türkay; Yilmaz, Mustafa Kemal
The main objectives of this study are to: (i) measure hospital service quality by using analytic hierarchy process (AHP) and analytic network process (ANP) as a multi-criteria decision making method to acquire the relationship and the level of the importance among service quality measurement (SERVQUAL) dimension; (ii) find perceived service quality with respect to different hospital classes (A, B and C) in Istanbul, Turkey; (iii) compare AHP- and ANP-based weighted SERVQUAL scales with the unweighted SERVQUAL scale for public hospital service quality in terms of different hospital classes (A-B and C). First, four hospitals are selected randomly for each class and then, a questionnaire based on the SERVQUAL model is conducted for each class to measure perceived service quality with respect to five major criteria, namely tangible, reliability, responsiveness, assurance and empathy, from patients' viewpoints at hospitals. Next, the second questionnaire based on ANP is developed to evaluate the importance of criteria and construct the relations among the criteria. The study sample contains 281 outpatients totally. Three important findings are obtained in this study. First, there is a significant difference among different hospital classes regarding the perceived service quality. Second, according to the patients, the most important service quality dimensions are empathy, the knowledge of employees, sympathetic and reassuring employees, services provided at the time promised to do so, and safe feeling of patients in interactions with hospital employees. Thirdly, the, perceived service quality through the AHP- and ANP-based SERVQUAL scale is higher than that with the unweighted SERVQUAL scale.
AtıfScopus93WoS74OpenAlex100İncele - MakaleYalnız künye2012Scopus SJRQ4Investigation of anti-oxidative and anti-genotoxic effects of Origanum vulgare L. essential oil on human lymphocytes in vitro
Ceker, Selcuk; Agar, Guleray; Nardemir, Gokce; Anar, Mustafa; Kizil, Hamit Emre; Alpsoy, Lokman
Origanum vulgare L. (Lamiaceae) is a flavoring herb widely using around the world. Some preparations and extracts from O. vulgare have been used in Turkish traditional medicine to treat several ailments including digestive disorders and menstrual problems. This study is designed to examine the chemical composition and in vitro antigenotoxic and antioxidant activity of the essential oil of O. vulgare (OVE) from Turkey. The essential oil of O. vulgare was analized by using GC. OVEs that were investigated antagonistic effects against oxidative stress and the genotoxic effects of aflatoksin B1 (AFB1). Anti-genotoxic activity was evaluated by sister chromatid exchanges (SCEs) and micronucleus (MN) tests. In additional to investigating protective role of OVEs against the oxidative stress of AFB1 in vitro, oxidative status was assessed on erythrocytes by measuring following oxidative stress markers like; super oxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA).The total of the 25 identified components are accounted for 96.03 % (GC). Major components of the oil were β-caryophyllene (20.40%), and caryophyllene oxide (34.44%). In the SCE and MN tests, it was observed that OVEs suppressed the mutagenic effects of AFB1. OVEs were observed to modulate the adverse effects of AFB1. The results of this experiment clearly reveal that OVEs have strong anti-oxidative and anti-genotoxic effect. These anti-genotoxic effects of O. vulgare essential oils are probably related to its action on the enzymatic activation system. Anti-oxidative and anti-genotoxic effect may be role of these compounds (β-caryophyllene and caryophyllene oxide).
AtıfScopus14WoS16OpenAlex12İncele - MakaleAçık Erişim2012Scopus SJRQ1Facility layout using weighted association rule-based data mining algorithms: Evaluation with simulation
Altuntas, Serkan; Selim, Hasan
Facility layout has considerable effects on the operational productivity and efficiency of a facility because of its direct effect on material handling costs. The objective of this study is to propose new weighted association rule-based data mining approaches for facility layout problem. Classic association rule-based approaches assume that each item has the same level of significance. On the other hand, in weighted association rule-based approaches, each item is assigned a weight according to its significance with respect to some user defined criteria. In this study, different weighted association rule-based data mining approaches, namely MINWAL(O), MINWAL(W), WARM and BWARM, are applied to facility layout problem. To confirm the viability of the proposed approaches, two case studies are presented. The approaches are compared in terms of general performance criteria for the facility layout problems using simulation. This is the first study that applies weighted association rule-based data mining approaches to facility layout problem. To address the needs in practice, "demand", "part handling factor" and "efficiency of material handling equipment" are used as the weighting criteria. Then, this study differs from the previous works in that it considers the three key location factors together.
AtıfScopus45WoS28OpenAlex43İncele - MakaleAçık Erişim2012Scopus SJRQ2The impact of heavy metals on the activity of carbonic anhydrase from rainbow trout (Oncorhynchus mykiss) kidney
Söyüt, Hakan; Beydemir, Şükrü
Many environmental and health problems have become a consequence of contamination of soil and water by toxic heavy metals and organic pollutants in the present age of technology. Heavy metals play vital roles in enzyme activities and other metabolic events with their bioaccumulative and nonbiodegradable properties among aquatic pollutants. Metal toxicity causes irregular metallothioneins protein synthesis, renal damage, and disruption of bone structure in humans and wildlife. In this study, we investigated in vitro effects of some metals on chemical-targeted carbonic anhydrase (CA) enzyme from rainbow trout kidney. The enzyme was purified with a specific activity of 17,285 EU × mg-1 and 31.7% yield and approximately 1800-fold using simple affinity purification method. Molecular weights of the subunit and native enzyme were estimated as 28.7 kDa and 26.9 kDa via sodium dodecyl sulfate polyacrylamide gel electrophoresis and Sephadex-G 200 column, respectively. Other kinetic properties of the enzyme were determined. Apparent Km, Vmax and kcat values were 0.40 mM, 0.097 μmol min-1 and 15.2 s-1 for p-nitrophenylacetate substrate, respectively. Inhibitory effects of cobalt, zinc, copper, cadmium and silver on CA activity were determined using the esterase method under in vitro conditions. IC50 and Ki values were calculated for metals. Ki values for Co2+, Zn2+, Cu2+, Cd2+ and Ag+ were 0.035, 1.2, 34.8, 103 and 257 from Lineweaver-Burk graphs, respectively. Consequently, in vitro inhibition rank order was determined as Co2+ > Zn2+ > Cu 2+ > Cd2+ > Ag+. The potential inhibitor for CA was found as Co2+ from these results.
AtıfScopus17WoS17OpenAlex17
İncele - BildiriYalnız künye2012Scopus SJRQ3Optimization of process parameters for removal of Cr(VI) by Hypnum cupressiforme using response surface methodology (RSM)
Özkan, Esra; Gürses, Ahmet; Açikyildiz, Metin; Güneş, Kübra
Response surface methodology was applied to optimize the removal of chromium ion by Hypnum cupressiforme from an aqueous solution. Experiments were analyzed using response surface methodology (RSM). The biosorption process was investigated as a function of five independent factors, sorption time, sorption temperature, initial ion concentration, sorbent dosage, and mixing rate. The optimum conditions for the chromium biosorption were found to be 760 min, 313K, 30mg/L, 0.01 mg/100mL, 107 min-1 respectively, for sorption time, sorption temperature, initial ion concentration, sorbent dosage, and mixing rate.
AtıfScopus2İncele - MakaleAçık Erişim2012Scopus SJRQ2Synthesis and carbonic anhydrase inhibitory properties of novel bromophenols including natural products
Balaydiin, Halis Türker; Soyut, Hakan; Ekinci, Deniz; Göksu, Sleyman; Beydemir, Şkrü; Menzek, Abdullah; Şahin, Ertan
(2-Bromo-3,4-dimethoxyphenyl) (3,4-dimethoxyphenyl)methanone (10) and its derivatives with Br, one dibromide and isomeric three tribromides, were synthesized. Demethylation of these compounds afforded a series of new bromophenols. Inhibition of human cytosolic carbonic anhydrase II (hCA II) isozyme by these new bromophenols and naturally occurring 3,4,6-tribromo-5-(2,5- dibromo-3,4-dihydroxybenzyl)benzene-1,2-diol (3), and 5,5′-methylenebis(3, 4,6-tribromo-benzene-1,2-diol) (4) was investigated. The synthesized compounds showed carbonic anhydrase inhibitory capacities with IC 50 values in the range of 0.7372 μM against hCA II. Some bromophenols investigated here showed effective hCA II inhibitory activity and might be used as leads for generating novel carbonic anhydrase inhibitors which are valuable drug candidates for the treatment of glaucoma, epilepsy, gastric and duodenal ulcers, neurological disorders, or osteoporosis.
AtıfScopus42WoS43OpenAlex41İncele - BildiriAçık Erişim2012Scopus SJRQ1The relation of collector and storage tank size in solar heating systems
Çomakli, Kemal; Çakir, Uǧur; Kaya, Mehmet; Bakirci, Kadir
The most popular method to benefit from the solar energy is to use solar water heating systems since it is one of the cheapest way to benefit from the solar energy. The investment cost of a solar water heating system is very low, and the maintenance costs are nearly zero. Using the solar energy for solar water heating (SWH) technology has been greatly improved during the past century. A storage tank is used in many solar water heating systems for the conservation of heat energy or hot water for use when some need it. In addition, domestic hot water consumption is strongly variable in many buildings. It depends on the geographical situation, also on the country customs, and of course on the type of building usage. Above all, it depends on the inhabitants' specific lifestyle. For that reason, to provide the hot water for consumption at the desirable temperature whenever inhabitants require it, there must be a good relevance between the collectors and storage tank. In this paper, the optimum sizes of the collectors and the storage tank are determined to design more economic and efficient solar water heating systems. A program has been developed and validated with the experimental study and environmental data. The environmental data were obtained through a whole year of operation for Erzurum, Turkey.
AtıfScopus103WoS87OpenAlex108İncele - BildiriAçık Erişim2012Scopus SJRQ2An evaluation index system for prediction of technology commercialization of investment projects
Altuntas, Serkan; Dereli, Turkay
Technology commercialization is a hot topic for governments, entrepreneurs, marketers and researchers due to the fact that its measurement is quite important for decision makers to know their possible growth potential in a dynamic and competitive environment. Having a high technology commercialization potential for invested technology is the engine of national development and growth as well. However, the measuring technology commercialization of any investment project is difficult because of the fact that there are some difficult questions, which should be answered exactly. For example, 'how will the technology be marketed in own sector?' 'Which factors are important for considered technology and affect technology commercialization?' 'Which scientific methods should be used for predication of technology commercialization potential properly?' and so on. The purpose of this study is to develop an evaluation index system for predicting the technology commercialization of the investment project. At the beginning of this study, a review of the technology commercialization literature is performed to address the factors which affect technology commercialization. Then, the evaluation index system proposed in this study can be used to prioritize investment projects in terms of their technology commercialization potential. It uses fuzzy multi-criteria decision making (FMCDM) methods and beta distribution to estimate the mean of each factor. Next, a solution approach to find an index value which shows technology commercialization potential is proposed. The proposed approach firstly finds interrelationships among the factors under fuzziness by using the fuzzy decision-making trial and evaluation laboratory (Fuzzy DEMATEL) method. Subsequently, it makes use of the fuzzy Analytic Network Process (Fuzzy ANP) method to determine the weights of factors. The values of all factors are then predicted by experts and assessed by beta distribution to estimate the mean of each factor with respect to the experts' opinion. Finally, a case study is presented to demonstrate the usefulness of the proposed approach.
AtıfScopus25WoS18OpenAlex34İncele - MakaleYalnız künye2012Scopus SJRQ2Reflection and refraction of a harmonic SH wave at the interface of two dissimilar media with microheterogeneity
Altan, Burhanettin S.
Reflection and refraction of harmonic SH-waves from the interface of two dissimilar media with microheterogeneity is studied. The effect of the microheterogeneity on the overall behavior of the media is taken into account by adding higher order displacement gradients in the stress-strain relationship. It is found that a harmonic wave reflects back with the same angle of the incident wave, like in a classical case. However, it is found that the direction of propagation of the refracted wave is dependent on the wave number. It is also shown that the critical angle for which the incident wave cannot be transmitted to the other half plane is dependent on the wave number.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2012Scopus SJRQ3Effect of magnetic flux distribution and magnetic powder addition on the magnetic levitation force of Sm123 superconductors
Abdioglu, M.; Ozturk, K.; Kutuk, S.; Bolat, S.; Yanmaz, E.
Sm123 and Sm211 were prepared by melt-powder-melt-growth and solid-state-reaction techniques, respectively, to have the nominal composition of (Sm123) 0.75 (Sm211) 0.25. After the preparation of this composition, the Fe-B magnetic powder (MP) was added to the composition for 0.000, 0.010, 0.015, 0.025, 0.050 wt.% to investigate the effect of MP addition on the levitation force density (LFD). Additionally, different permanent magnets (PM) were used as magnetic-field source to investigate the effect of magnetic-field gradient on the LFD of MP added superconductors. Our findings indicate that the MP addition acts as a flux pinning centre in the sample and enhances the LFD up to 0.025 wt.% adding amount, and the optimum flux gradient which produces a screening current in the sample occurs when the B/d (magnetic-field intensity/ diameter of PM) ratio is equal to 0.060. These results imply that the experimental data can be useful for fabricating process of superconducting samples with larger MLF values, and designing of superconducting magnets, flywheel energy storage and maglev systems.
AtıfScopus10WoS10OpenAlex10İncele - MakaleYalnız künye2012Scopus SJRQ1A nondestructive testing technique: Nail penetration test
Selcuk, Levent; Gökce, H. Suleyman; Kayabali, Kamil; Simsek, Osman
This study presents a practical nondestructive testing (NDT) method: the nail penetration test (NPT). The major tools of the test technique are a gas nailer with 130 J (95.88 ft-lbf) power, concrete nails, and a gas nailer cell. The study covers three different limestone aggregate types. Six concrete mixtures were prepared from each aggregate type. Five nail shots were performed on each concrete mixture (or grade) and the average value was obtained. The average nail penetration depths were correlated with the compressive strength of concrete. Other NDT techniques, such as the Schmidt rebound hammer (SRH), ultrasonic pulse velocity (UPV), and Windsor probe (WP), were also applied to concrete samples. The measured compressive strength values were compared with those obtained from the empirical relationships using the data from the NPT, SRH, UPV, and WP. It was found that the reliability of the NPT to estimate the compressive strength of concrete is very high. The tool employed in the investigation covers a relatively wide range of compressive strength of concrete. This testing tool is proposed to estimate the compressive strength of in-place concrete.
AtıfScopus15İncele - MakaleAçık Erişim2012Scopus SJRQ3Dynamic and interactive mathematics learning environments: The case of teaching the limit concept
Martinovic, Dragana; Karadag, Zekeriya
This theoretical study is an attempt to explore the potential of the dynamic and interactive mathematics learning environments (DIMLE) in relation to the technological pedagogical content knowledge (TPACK) framework. DIMLE are developed with intent to support learning mathematics through free exploration in a less constrained environment. A typical DIMLE software package has interactivity and dynamism as key affordances; these are especially suitable for enhancing learning and teaching with technology of the essentially dynamic mathematics concepts. Moreover, we propose that DIMLE and their affordances should be studied under the TPACK framework because this framework is explicit in considering technology-supported mathematics learning as a qualitative add-on as contrasted to what would be a simple totalling of technological, pedagogical and mathematical knowledge. As an example, we focus in our discussion on using a DIMLE in order to support learner in development of the limit concept.
AtıfScopus15OpenAlex29İncele - MakaleYalnız künye2012Scopus SJRQ3The use of the internet by pre-service teachers' for educational purposes
Kahraman, Sakip; Yalcin, Sema Altun; Erkol, Mehmet; Kisoglu, Mustafa
The aim of the research is to investigate why students at the Faculty of Education use the Internet. The sample of the study consisted of 348 students (178 female, 170 male) enrolled in the Faculty of Education at Bayburt University in Turkey. The data was collected using a survey which is consisted of seven questions developed by the researchers. The obtained data was statistically analyzed and responses given by students were calculated as frequency (f) and percent (%) values. The findings indicated that students frequently use the Internet for academic purposes, general subjects and communication. Additionally, it was determined that students use the Internet on average a few times per week both for academic purposes and general subjects. It was found that students mostly downloaded text material from the Internet while they were searching a subject. According to the results of the study students prefer to access Turkish web sites more than English web sites for academic purposes. It is held that students use the Internet more than library while they are searching for academic purposes. Furthermore, it is stated that nearly half of students believed that the Internet services can take the place of the libraries. At the same time, majority of the students believed that the internet improves students' achievement.
AtıfScopus2İncele - MakaleAçık Erişim2012Scopus SJRQ1Effect of ultrasound treatment on steady and dynamic shear properties of glucomannan based salep dispersions: Optimization of amplitude level, sonication time and temperature using response surface methodology
Karaman, Safa; Yilmaz, Mustafa Tahsin; Ertugay, Mustafa Fatih; Baslar, Mehmet; Kayacier, Ahmed
The present study investigated effect of different amplitude levels (40, 70 and 100%), sonication temperatures (40, 50 and 60 °C) and exposure times (3, 7 and 11 min) on steady shear properties; apparent viscosity (η), shear stress (σ), consistency coefficient (K), flow behavior index (n) and dynamic shear properties; storage modulus (G′), loss modulus (G″), complex viscosity (η), complex modulus (G) and loss tangent (tan δ) values of glucomannan based salep solution (SS) and salep drink (SD) samples. In addition, the steady and dynamic shear properties were optimized using ridge analysis in terms of amplitude level, sonication temperature and exposure times levels. Increasing amplitude level and sonication time decreased considerably the η, σ, K, G′, G″ and η values of salep dispersions (SS and SD samples). However, sonication temperature did not have a remarkable effect on these properties.
AtıfScopus40WoS36OpenAlex42İncele - BildiriYalnız künye2012Scopus SJRQ1The role of cogeneration systems in sustainability of energy
Çakir, Uǧur; Çomakli, Kemal; Yüksel, Fikret
Cogeneration system (CHP) is one of the ways to save the energy and use the energy efficiently. When compared to separate fossil-fired generation of heat and electricity, CHP may result in a consistent energy conservation (usually ranging from 10% to 30%) while the avoided CO 2 emissions are, as a first approximation, similar to the amount of energy saving. In terms of sustainability, one of the primary considerations is energy efficiency. Sustainable energy is considered as a kind of energy which is renewable and continuous, meaning that the use of such energy can potentially be kept up well into the future without causing harmful repercussions for future generations. In this study, environmental benefits and sustainability aspects of cogeneration systems and importance of those systems to the use of sustainable energy are underlined. To support this idea, first we have referred some scientific studies previously made on cogeneration systems and then we have used our own case study. The case study made on gas engined cogeneration system was applied for a hospital to show the sustainability aspects of cogeneration systems.
AtıfScopus115WoS97OpenAlex135İncele