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Koleksiyondaki öğeler
- MakaleYalnız künye2022Scopus SJRQ2Applications of innovative polygonal trend analyses to precipitation series of Eastern Black Sea Basin, Turkey
Hırca, Tuğçe; Eryılmaz Türkkan, Gökçen; Niazkar, Majid
Examining historical variations of hydroclimatic variables can provide crucial information about changes of water resources in a water cycle. In this study, the Mann–Kendall (MK) and Innovative Polygon Trend Analysis (IPTA) methods were applied to 56-year precipitation data collected at 8 measuring stations. These stations are located in Eastern Black Sea Basin (EBSB), which has a significant amount of annual precipitation and hydroelectric potential in Turkey. This study has two objectives: (1) investigating possible changes in the monthly precipitation and (2) comparing the results achieved by a classical (MK) and one of the latest trend analysis methods presented in the literature (IPTA). Based on the results, MK achieved no trend for most of months, while it reached an increasing trend for March at most of the stations. Likewise, IPTA determined an increasing trend for March precipitation. However, an increasing/decreasing trend was obtained by IPTA for most of the months and stations. In other words, comparing the trend analysis results obtained by IPTA and MK indicates a significant discrepancy between the numbers of months with detected trends primarily because the former is relatively more sensitive in trend identification. To be more precise, IPTA and MK determined trends in approximately 81.25% and 12.5% of all months, respectively. Furthermore, the former identified quite the same trends in every month which the latter reported a trend. Moreover, the polygon of the mean and standard deviation graphs developed by IPTA provides a year cycle, which brings about useful information for water utility sectors and decision makers of the study area. Finally, the findings of this study contribute to a large amount of research that attempts to explore spatio-temporal variations of hydroclimatic variables around the globe not only to enhance humans’ knowledge about changes in a water cycle but also assess climate change impacts.
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İncele - MakaleAçık Erişim2022Scopus SJRQ3Functional and technological characterization of lactic acid bacteria isolated from Turkish dry-fermented sausage (sucuk)
Kamiloğlu, Aybike
In this study, 10 lactic acid bacteria were isolated from Turkish fermented sausage (sucuk) and identified as 5 Lactobacillusplantarum, 1 Pediococcus acidilactici, 1 Weissella hellenica, 1 Lactobacillus pentosus, and 2 Lactobacillus sakei. PCR screening of genes encoding plantaricin A and pediocin showed the presence of plantaricin A gene in 9 and pediocin gene in 3 of strains. All isolates showed antibacterial and antifungal effect on most of the tested microorganisms. gad gene, encoding glutamic acid decarboxylase enzyme, was detected in all isolates except Weisella hellenica KS-24. Eight of isolates were determined as gamma-amino butyric acid (GABA) producer in the presence of 53 mM mono sodium glutamate (MSG) by HPLC and TLC analysis. DPPH scavenging activity was observed for all isolates. Additionally, isolates were able to produce exopolysaccharide in the presence of sucrose. The best exopolysaccharide (EPS) production was achieved with L.plantarum KS-11 and L.pentosus KS-27. As a result, this study characterized some techno-functional properties of LAB isolates from sucuk. It was concluded that the isolates studied have the potential to be used in obtaining functional products in meat industry, as well as strain selection may be effective in providing the desired properties in the product.
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İncele - MakaleAçık Erişim2022Scopus SJRQ3An Investigation of the Effect of Curing Temperature on the Deformation Characteristics of the Stabilized Soil Layers Treated with Lime and Tuff Wastes with Response Surface Method
Kamiloglu, Hakan Alper; Turan, Huseyin
The shallow spread foundations are one of the widely used foundation types for low-rise, low-cost or commercial buildings. However, it is not possible to use this type of foundation for soils with low bearing capacity or capable of excessive settlements. In these cases, stabilized soil layers overlying insufficient soil may be alternative to the high-cost foundation systems. As the temperature of the soils depends mostly on air temperature for shallow depths, curing conditions of the stabilized soil layers are affected by the air temperature. The effect of curing temperature on the pressure-settlement relation of the layered soil is a gap in the literature. This study investigates the effect of Bayburt tuff on pressure-settlement characteristics of layered soil for various curing temperatures. The specific objectives of this paper are to (1) examine the effect of using the waste tuffs as a stabilization agent in layered soils, (2) evaluate the usability of response surface methodology (RSM) to estimate shear strength parameters (c, ϕ), unconfined compression strength, and secant modulus of the stabilized soil with less experiment, (3) investigate the effect of dimensions of the stabilized soil block (length, with and thickness) on pressure-settlement relations under various curing temperature (T = 3 °C, 13 °C, 23 °C, 33 °C, 43 °C). This study comprises experimental and numerical parts. In the experimental part, strength parameters (c, ϕ) and secant modulus of stabilized soil samples were estimated with response surface methodology for various curing temperatures (3 °C, 23 °C, 43 °C). The effects of curing temperature on shear strength and Bulk’s modulus parameters were determined with the derived RSM model. In the numerical part of the study plate load test was simulated with the derived 2D axisymmetric FE model. The parameters required for the FE analyses were determined with the derived RSM model. As a result of the study, it was seen that it is possible to estimate experimental parameters accurately using the RSM approach with fewer tests. Bayburt tuff and lime mixtures increase the stiffness of the layered soil. The curing temperature has considerable effects on the pressure-settlement relationship up to a certain value. After a certain value increasing curing temperature has no considerable effects on the stiffness of the layered soil.
AtıfScopus3WoS1İncele - MakaleYalnız künye2020Scopus SJRQ2Investigating the Optimum Model Parameters for Casting Process of A356 Alloy: A Cross-validation Using Response Surface Method and Particle Swarm Optimization
Şensoy, Abdullah Tahir; Çolak, Murat; Kaymaz, Irfan; Dispinar, Derya
This study aimed to determine the optimal casting parameters for the maximum fluidity of A356 alloy. Gravity die cast method was used. For this purpose, central composite design (CCD) was performed. The input parameters and their limits for the trial design were selected as pre-heating temperature (100–400 °C), casting temperature (680–760 °C), and cross-sectional thickness (1–10 mm). Using the CCD-based simulation results of the feed distance, a highly correlated full-quadratic regression equation was obtained with the highest R2 (0.99), which then was used as the objective function for the particle swarm optimization (PSO) process. The highest value of the response parameter, flow distance, reached up to 491.19 mm when the input parameters were selected as 400 °C, 760 °C and 10 mm, respectively. The sensitivity analysis has shown that the most effective parameter on the fluidity is the cross-sectional thickness. The response surface method (RSM)-based optimization results have been also validated using the PSO method. Although the higher temperatures have been found to result in better fluidity, there may be some drawbacks to working at higher temperatures such as energy cost and mould life. To determine the optimum input parameters, the RSM model suggested in this study can be modified for any type of casting process. Moreover, especially for a complex-shaped part, the manufacturer can be advised regarding operating conditions such as pre-heating and casting temperatures.
AtıfScopus11WoS9OpenAlex13İncele - MakaleAçık Erişim2022Scopus SJRQ2Pollen morphology of some Veronica species (Plantaginaceae) from Turkey
Varlik, Kader; Armagan, Metin; Bülbül, Ali Savaş
The aim of the present work is to provide an account on the morphological features of pollen of Veronica species in Turkey, as a contribution to future research. Pollen morphology of 20 species of the Veronica were investigated using Light Microscope (LM) and Scanning Electron Microscope (SEM). Different palyno-morphological features including; pollen ornamentation, colpus ornamentation, size of polar and equatorial diameter, P/E ratio, exine thickness, and size of colpus were observed. The study revealed that the pollen grains of the studied Veronica species were in all cases tricolpate, radially symmetrical and isopolar, oblate-spheroidal or prolate spheroidal. The surface pattern of the exine varied from striato-reticulate and striatomicroreticulate to microechinate-perforate, which allows recognition of three homonymous types of pollen grains.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2020Tracking the pre-service teachers’ development of communicative skills and their beliefs towards communicative approach
Kurnaz, Yıldıray; Özbay, Ali Şükrü
Concerns about the purpose of developing communicative skills in English teaching and approaches to overcome these concerns have always had an important place in language teaching. In this context, besides the fact that teachers‟ roles are important, their beliefs about the approach have a profound influence on their professional achievement. In this regard, the aim of the present study was to determine Turkish English as a Foreign Language (EFL) student teachers‟ beliefs about developing their communicative skills with the communicative approach in Turkish context. The data obtained through Pre-Service Teacher Beliefs Questionnaire, in which 445 participants took part, and focus group interviews with 28 participants at several times and places were analysed by quantitative and qualitative data analysis methods respectively. As a result of the analysis, it was found that EFL student teachers generally had positive attitudes towards improving communicative skills of their prospective students with communicative approach; however, it was difficult for this approach to work properly in Turkey and in Turkish education system due to various reasons. In addition, it was found that EFL student teachers' self-efficacy beliefs were correlated with their attitudes towards the approach, and that many sub-factors such as second language proficiency also had an influence on the attitudes. Lastly, these findings were found to be significantly different according to the departments (ELL, ELT) rather than age and gender.
AtıfScopus3OpenAlex4İncele - MakaleAçık Erişim2020Scopus SJRQ3Influence of lactobacillus reuteri on internal organ weight, performance and meat quality of Japanese quail (Coturnixcoturnix japonica) under heat stress; [Einfluss von lactobacillus reuteri auf das gewicht der inneren organe, die leistung und die fleischqualität Japanischer Wachteln (Coturnix coturnix japonica) unter Hitzestress]
Tekce, E.; Bayraktar, B.; Aksakal, V.; Dertli, E.; Kamiloğlu, A.; Çinar Topçu, K.; Kaya, H.; Takma, C.; Yasulergezer, N.
In the present study, the effects of Lactobacillus reuteri E81 (LRE) supplemented at different doses (200, 400 and 600 mg/kg) into the diets on performance, meat quality and internal organ weights of Japanese quail (Coturnixcoturnix japonica) were investigated under heat stress (HS) conditions (37°C). For the experiments, 448 one-day old quails were used. Seven days of training (physical exercise) and a 35-day fattening period were applied. On day 7 of the trial, 8 groups [4 under control temperature of 25°C (CT): control (C), LRE-200, LRE-400 and LRE-600 and 4 under HS: control (HSC), SLRE-200, SLRE-400 and SLRE-600] were formed, each group consisting of four replicates with 14 quail each. At the end of this study, the CT group fed 400 mg/kg LRE showed the best performance results, whereas no effect was found for groups under HS in comparison to the control group (HSC). Samples taken on the 21st and 42nd day revealed that addition of probiotics in the CT and HS groups induced no effect on weight of the internal organs (p > 0.05). Analysis of meat quality on the 21st day showed that LRE caused an increase in pH in both the HS and CT groups. Further, 400-mg/kg LRE supplementation induced an increase in thiobarbituric acid reactive substances (TBARS) in the group under HS. In the CT groups on day 42 no effect of LRE was found on colour parameters or on the TBARS value, except for a decrease in the pH value in the LRE supplemented groups compared with the control. In HS groups a decrease in the L* value and an increase in the TBARS value was found compared to CT groups (p < 0.05), but there was no effect on other colour parameters or pH value. In conclusion, in the present study supplementation of different doses of LRE E81 to quail diets had no effect on performance, internal organ weight or meat quality under HS.
AtıfScopus2WoS2OpenAlex6İncele - MakaleAçık Erişim2021Scopus SJRQ1Existence and multiplicity of solutions for a Schrödinger–Kirchhoff type equation involving the fractional p(. ,.) -Laplacian operator in RN
Ayazoglu, Rabil; Saraç, Yeşim; Şener, S. Şule; Alisoy, Gülizar
In this paper, by using variational approach, Mountain Pass Theorem and Krasnoselskii’s genus theory, we show the existence and multiplicity of solutions for a Schrödinger–Kirchhoff type equation involving the fractional p(. ,.) -Laplacian in fractional Sobolev space with variable exponent. We also establish a Bartsch–Wang type compact embedding theorem for fractional Sobolev space with variable exponent.
AtıfScopus21WoS22OpenAlex22İncele - MakaleYalnız künye2019Scopus SJRQ3Production of enantiomerically enriched chiral carbinols using Weissella paramesenteroides as a novel whole cell biocatalyst
Tozlu, Caner; Şahin, Engin; Serencam, Hüseyin; Dertli, Enes
In this study, four bacterial strains were tested for their ability to reduce acetophenones to its corresponding alcohol. Among these strains Weissella paramesenteroides N7 was found to be the most successful biocatalyst to reduce the ketones to the corresponding alcohols. The reaction conditions were systematically optimized for W. paramesenteroides N7 that resulted in high enantioselectivity and conversion rates for the bioreduction. The scale-up asymmetric reduction of 1-(4-methoxyphenyl) propan-1-one (1r) by W. paramesenteroides N7 gave (R)-1-(4-methoxyphenyl) propan-1-ol (2r) with 94% yield and >99% enantiomeric excess. This is the first report showing the synthesis of (R)-1-(4-methoxyphenyl) propan-1-ol (2r) in enantiopure form using a biocatalyst on a gram scale. The whole cell catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that W. paramesenteroides N7 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest as a promising and alternative green approach.
AtıfScopus12WoS10OpenAlex11İncele - MakaleAçık Erişim2021Scopus SJRQ3Synthesis of alternan-stabilized zinc nanoparticles: morphological, thermal, antioxidant and antimicrobial characterization
Yücel, Nur; İspirli, Hümeyra; Mercan, Emin; Erdoğan, Ümmügülsüm; Dertli, Enes
This study aimed to synthesize zinc nanoparticles with antimicrobial and antioxidant activities using alternan (ZnNPs-Alt) produced by Lactobacillus reuteri E81 as the stabilizing agent. For the characterization of the ZnNPs-Alt, UV–vis spectroscopy, SEM, TEM and EDX analysis, XRD, FTIR and DSC analysis were applied. The functional role of ZnNPs-Alt was tested by determination of their antioxidant activities by DPPH and CUPRAC methodologies and their antibacterial and antifungal activities. Results of this study demonstrated that alternan was utilized as a successful stabilizer to produce crystalline, thermally stabile ZnNPs-Alt with a particle size of ∼ 100 nm. Importantly, strong antioxidant and antimicrobial activities were observed for ZnNPs-Alt in a concentration dependent manner. These findings confirmed the role of alternan as a stabilizing agent for the production of ZnNPs-Alt with functional roles.
AtıfScopus6WoS6OpenAlex8İncele - MakaleAçık Erişim2021Scopus SJRQ1Processing of skim milk powder made using sonicated milk concentrates: A study of physicochemical, functional, powder flow and microbiological characteristics
Sert, Durmuş; Mercan, Emin; Dinkul, Muhsin; Aydemir, Serdar
The impact of sonication treatment (0, 5, 15, 30, and 60 min) of skim milk concentrates on physicochemical, functional, powder flow behaviour, and microbiological properties of milk powders was investigated. Sonication resulted in higher firmness and consistency of concentrates with increasing treatment time. In milk powders, higher L∗ and a∗ values were observed in sonicated samples. D[4,3] parameter of milk powders was between 8.1 and 255.0 μm, and sonication for 60 min decreased this value. Sonication significantly decreased the caking, cohesion, and compaction properties of samples. The flow stability of sonicated samples was higher than that of the control. Sonication can result in improved flow characteristics of milk powders in terms of caking, cohesion, and compaction. These observations could relate to effects of sonication on casein micelle, whey proteins denaturation, whey/whey or casein/whey aggregation. Sonication of milk concentrates was also effective in reducing the microbial counts of milk powders.
AtıfScopus14WoS13OpenAlex13İncele - MakaleAçık Erişim2021Scopus SJRQ3Response of probiotics and yeast added in different doses to rations of anatolian merino lambs on fattening performance, meat quality, duodenum and rumen histology[1]; [Z anadolu merinos kuzularının rasyonlarına farklı dozlarda ilave edilen probiyotiklerin ve mayanın besi performansı, et kalitesi, rumen ve duodenum üzerine yanıtı]
Tekce, Emre; Bayraktar, Bülent; Aksakal, Vecihi; Dertli, Enes; Kamiloğlu, Aybike; Karaalp, Musa; Timurkaan, Sema; Gül, Mehmet
This study investigated the effects of dietary probiotics (Lactobacillus reuteri E81 [LRE], Lactobacillus rhamnosus GG [LRG]), yeast (Saccharomyces cerevisiae S81 [SCS]), and their combined supplementation on fattening performance (BW, DWG, FI, and FCR), meat quality, and rumen and duodenum histology in lambs. The study material comprised ninety 2.5-month-old Anatolian Merino lambs, and the trial was conducted for 70 days. Nine trial groups, each composed of 10 animals, were established. This study demonstrated that, when compared to the control group, the best fattening performance was achieved in the lambs that received 600 ppm of dietary LRE. Neither visceral organ weights nor rumen and duodenum histology was affected in the groups that received the tested feed supplements. Of the meat colour parameters investigated, the L* value was observed to have increased in the groups that were given feed supplements, excluding Groups LRE-600 and SCS-300. It was determined that the probiotic supplements had no effect on the a* and b* colour parameters, but affected the meat pH value. In conclusion, the assessment of the effects of different doses of dietary probiotics, yeast, and probiotic-yeast combinations on performance parameters, visceral organ weights, and meat quality in Anatolian Merino lambs showed that the best results were achieved in the group that received 600 ppm of LRE alone.
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İncele - MakaleAçık Erişim2021Scopus SJRQ2Fatty acid compositions and quality of egg and performance in laying quails fed diet with hesperidin
Özbilgin, Abdullah; Kara, Kanber; Gümüş, Recep; Tekçe, Emre
This study investigates the effects of hesperidin on eggs’ internal and external quality parameters, the fatty acid in egg yolk, and the nutrient content adding different amounts of hesperidin to the quail diets. A total of 150 Japanese quails (Coturnix coturnix japonica) were divided into three groups (0% hesperidin group (n = 5 × 10) (control group; HES0), 0.1% hesperidin group (HES1), and 0.2% hesperidin group (HES2)) with five replicates. It has been found in the analysis that hesperidin did not affect the weight and thickness of the shell from the external quality parameters of the egg (P > 0.05), but in terms of the HES1 and HES2 groups, the weight of the egg increased compared to the HES0 group, while the fracture resistance of the shell decreased (P < 0.05). Eggs’ internal quality parameters have shown that the egg white width (P < 0.05) and the yolk diameter (P < 0.01) increased in the HES1 and HES2 groups, and the length of white decreased (P < 0.05). It has been found that n-6 (linoleic acid) and n-3 (docosahexaenoic acid) fatty acid values increased significantly according to hesperidin dosage (P < 0.05) from the parameters of the composition of fatty acids of the eggs. As a result, it is believed that hesperidin added to the diet has a generally positive effect on the fatty acid composition and internal and external quality parameters of the eggs and would be appropriate to use it as a feed additive.
AtıfScopus8WoS8OpenAlex9İncele - MakaleAçık Erişim2020Scopus SJRQ3Determination of the impact damage threshold point of composite material using fuzzy-base taguchi method
Erbayrak, Seda; Erbayrak, Engin
In this study, the impact damage threshold point of composite materials was determined using the optimum design parameters obtained from the Fuzzy Based Taguchi Method (FBTM). It is known that both Taguchi and Fuzzy methods provide optimization of design parameters yet, in Taguchi method, optimization of design parameters is not sufficient in solving multi response optimization problem. Therefore, Fuzzy Logic system was combined with the Taguchi system for working out the multi-response optimization problem. In this study, the low velocity impact damage analyses were performed in an LS-DYNA 3D explicit finite element program. ASTM D7136/D7136M standard was used during the low velocity impact analyses. In explicit finite element analyses, contact algorithms were executed to observe better damage zone shapes. Furthermore, the control parameters (termination and computation time step) were tuned to provide perfect correlation with the force-energy-time histories. The study concluded that Fuzzy Based Taguchi Method (FBTM) is much more capable of optimizing the design parameters that predict the impact damage threshold point of the composite material.
AtıfScopus11İncele - Kitap BölümüAçık Erişim2022Methods of fabrication of bionanocomposites
Cuce, Pinar Mert; Cuce, Erdem; Guclu, Tamer
Petrochemical-based plastic packaging materials that cannot be biodegradable and remain intact in nature for many years and the continuous proliferation of these materials as waste has become an international problem. As a result of this problem, bionanocomposites produced from biodegradable materials represent a new class of nanosized materials with various uses, from various daily uses to food packaging applications. It consists of a biobased component and at least one-dimensional nanosized particles. It differs from nanocomposites with fundamental differences such as preparation methods, functions, biodegradability, biocompatibility, and obtaining methods. In the presented study, the production methods of bionanocomposites are explained with some examples obtained by these methods. Generally, there are four main production methods: in situ intercalative polymerization, solution intercalation, template synthesis, and melt intercalation. With these methods, bionanocomposites can be produced that are homogeneously dispersed and provide major enhancements in mechanical, thermal and water vapor barrier characteristics compared to base polymers. It is capital to use the appropriate method and to make the correct synthesis according to the base polymer used and the type of nanoparticle added, to obtain a homogeneous and nonagglomerated bionanocomposite synthesis.
AtıfScopus4OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ2MODELLING AND VALIDATION OF EFFECT OF BINDER TYPE ON FEEDING BEHAVIOUR OF SPHEROIDAL GRAPHITE CAST IRON
Çolak, Murat; Şekerden, Mete
In the casting method, it is crucial to properly make the moulding design to produce sound parts. Volumetric change, especially during the solidification of spheroidal graphite cast irons, may show different behaviour compared to steel and aluminium castings. In this study, castings were carried out with single and double feeders with varying casting parameters of green sand and resin mould sand containing different cross-sectional thicknesses. Depending on the chemical composition, mould rigidity and inoculation efficiency, and the importance of the feeder path was evaluated by experimental and modelling techniques. Consequently, it was observed that the risk of shrinkage in resin moulds is less than in green sand castings in the same moulding design. In addition, it has been found that the number of feeders and neck connection is an important parameter in pore formation.
AtıfScopus2OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ2Design and Experimental Studies on Superconducting Maglev Systems with Multisurface HTS-PMG Arrangements
Abdioglu, Murat; Ozturk, Kemal; Ekici, Mehmet; Savaskan, Burcu; Celik, Sukru; Cansiz, Ahmet
In this article, we have designed and constructed a new multisurface (MS) high temperature superconductor (HTS) Maglev measurement system to investigate the enhancement of magnetic force properties of Maglev systems via MS HTS configurations above conventional permanent magnetic guideway (PMG). We have investigated both the static force and stiffness behavior and dynamic response characteristics of these MS HTS-PMG arrangements in different field cooling heights (FCHs). Optimum cooling height is determined as FCH 20-30 for both six- and four-HTS configurations. The maximum levitation force values of HTS-PMG arrangement with six-HTS were obtained bigger than that of four-HTS in the unit cryostat volume of MS arrangement, indicating that the HTSs at the bottom side of the cryostat make contribution to the loading capacity of Maglev systems. In the present article, it is observed that the magnetic flux density of bottom surface in addition to upper surface of the PMG can make a contribution to loading performance, vertical and lateral stability of Maglev systems. It is thought that the designed measurement facility and results of this study will be beneficial to increase the magnetic flux density in the unit volume via MS HTS-PMG arrangements for future design and construction of the HTS Maglev systems.
AtıfScopus16WoS6OpenAlex15İncele - MakaleAçık Erişim2021Scopus SJRQ1Photovoltaic performance of non-covalent functionalized single-layer graphene in dye-sensitized solar cells (DSSCs)
Igman, Erdal; Bayram, Ozkan; Mavi, Ahmet; Hasar, Ugur Cem; Simsek, Onder
In this study, it was aimed to fabricate new effective alternative counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). For this purpose, firstly, single-layer graphene (SLG) thin films were grown by chemical vapor deposition (CVD) method. Then, these films were separately functionalized with 1,8-cineole (ppCin/SLG), D-Limonene (ppLim/SLG) and Thiophene (ppTh/SLG) by plasma polymerization. Number of layers in CVD-grown graphene determined by Raman, transmission electron microscope (TEM) and ultraviolet–visible (UV–Vis) spectroscopy. Chemical structures of plasma polymerised (pp) thin films were investigated by Fourier transform infrared (FTIR) spectroscopy. Photovoltaic parameters of DSSCs were calculated, and electrocatalytic properties of CEs were investigated by electrochemical impedance spectroscopy (EIS). Polymer functionalization greatly enhanced the electrical conductivity and electrocatalytic activity properties of graphene compared to that of SLG. The efficiencies of DSSCs with ppCin/SLG and ppLim/SLG CEs were 1.10% and 1.02%, respectively. As a result, the cell efficiencies of ppCin/SLG and ppLim/SLG could be as alternative materials to platinum (Pt) counter electrode.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2020Scopus SJRQ2Magnetic force and stiffness performances of Maglev system based on multi–surface arrangements with three-seeded bulk YBaCuO superconductors
Ozturk, K.; Abdioglu, M.; Karaahmet, Z.
We have designed a multi–surface HTS (high temperature superconductor with three seeded bulk YBaCuO) Maglev system by increasing the YBaCuO number while decreasing the PM number in HTS–PMG system to enhance the loading capacity and stability of the superconducting Maglev system while reducing the fabrication cost. By this study, a detailed investigation on the magnetic levitation force, guidance force, magnetic stiffness and cost analysis of the multi–surface HTS Maglev system has been carried out for the first time. In this study, it is determined that the multi–surface YBaCuO–PMG arrangements are superior to the single–surface arrangements with respect to the loading capacity and especially the movement stability of Maglev systems together. Additionally, it is seen that the using of the multi–surface YBaCuO–PMG arrangement reduces the fabrication cost of the Maglev systems as 42.0% for 1000 km magnetic rail while increasing of the levitation force efficiency as 43.4% and this emphasizes the advantage of multi–surface arrangements to the classical single–surface ones. The obtained results can contribute to the researchers working on Maglev and have a capability to increase the usage potential of Maglev systems in commercial applications because of both the loading capacity and stability of Maglev systems can be enhanced together with reducing the fabrication cost without any loss in levitation performance.
AtıfScopus19WoS18OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ2Targeting cov-2 spike rbd and ace-2 interaction with flavonoids of anatolian propolis by in silico and in vitro studies in terms of possible covid-19 therapeutics
Güler, Halil İbrahim; Ay Şal, Fulya; Can, Zehra; Kara, Yakup; Yildiz, Oktay; Beldüz, Ali Osman; Çanakçi, Sabriye; Kolayli, Sevgi
Propolis is a multi-functional bee product rich in polyphenols. In this study, the inhibitory effect of Anatolian propolis against SARS-coronavirus-2 (SARS-CoV-2) was investigated in vitro and in silico. Raw and commercial propolis samples were used, and both samples were found to be rich in caffeic acid, p-coumaric acid, ferulic acid, t-cinnamic acid, hesperetin, chrysin, pinocembrin, and caffeic acid phenethyl ester (CAPE) at HPLC-UV analysis. Ethanolic propolis extracts (EPE) were used in the ELISA screening test against the spike S1 protein (SARS-CoV-2): ACE-2 interaction for in vitro study. The binding energy values of these polyphenols to the SARS-CoV-2 spike and ACE-2 protein were calculated separately with a molecular docking study using the AutoDock 4.2.6 program. In addition, the pharmacokinetics and drug-likeness properties of these eight polyphenols were calculated according to the SwissADME tool. The binding energy value of pinocembrin was highest in both receptors, followed by chrysin, CAPE, and hesperetin. Based on the in silico modeling and ADME (absorption, distribution, metabolism, and excretion) behaviors of the eight polyphenols, the compounds exhibited the potential ability to act effectively as novel drugs. The findings of both studies showed that propolis has a high inhibitory potential against the Covid-19 virus. However, further studies are now needed.
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