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Koleksiyondaki öğeler
- MakaleYayıncıda açık erişim2021Scopus SJRQ3The effect of different microbial fertilizer doses on yield and yield components in coriander (Coriandrum sativum L.)
Gül, Volkan; Öztürk, Erdoğan
Microbial fertilizers containing Bacillus subtilis and Bacillus megaterium isolates are one of the important organic fertilizers, which strengthen the immune system of plants against harmful effects and promote the plant growth by fixing nitrogen from the atmosphere, to obtain better quality products. This study was conducted to determine the effects of different liquid microbial fertilizer doses (0, 500, 1000, 1500, 2000, and 2500 ml 100 L–1) on the yield and yield components of the coriander (Coriandrum sativum L.) grown in Bayburt in 2018 and 2019. The experiment was set up as three replicates in randomized complete block design. The results indicated that there was a considerable variation in the yield and yield components of coriander, and the yield significantly increased as the dose of microbial fertilizer was increased. The maximum essential oil content and seed yield were recorded for the plots grown under the F1 and F3 treatment. It was found that the maximum seed yield was obtained in the F3 treatment (839.0 kg ha–1), and the seed yield decreased in the F4 (754.1 kg ha–1) and F5 (759.9 kg ha–1) treatments. Although the increase in the microbial fertilizer dose increases seed yield, using the fertilizer in optimum dose can be more profitable. Therefore, this study suggests that the fertilizer dose “F3” can improve the productivity of the coriander grown in the areas treated with microbial fertilizer.
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İncele - MakaleAçık Erişim2021Scopus SJRQ2Effect of accelerated ageing on some surface properties of uv-coated hackberry (Celtis australis l.) wood parquet
Ayata, Ümit; Esteves, Bruno; Gürleyen, Levent; Çakicier, Nevzat; Ferreira, J.O.S.É.; Domingos, Idalina; Türk, Mutlu
The importance of UV-curable coatings is currently increasing. In the parquet industry, where UV systems are applied, it is beneficial to investigate new tree species as potential raw materials. This study was carried out to determine the effect of accelerated ageing on some surface properties of hackberry (Celtis australis L.) wood treated with UV system parquet varnish. UV system parquet varnishes were applied to hackberry wood surfaces in three and five layers, according to the requirements of industrial applications. The varnished surfaces were then exposed to UV rays for 252 and 504 h using UVA-340 lamps in a QUV ageing device. Glossiness, colour parameters, pendulum hardness and adhesion strength (pull-off) (MPa) were determined for the coated samples before and after ageing, and the results for the aged and unaged test samples were compared. Analysis of variance showed that the results were significant for all tests. The results for all tests varied by ageing time.
AtıfScopus5WoS4OpenAlex3İncele - MakaleAçık Erişim2020Scopus SJRQ3The analgesic effect of metformin on paclitaxel-induced neuropathic pain model in rats: By considering pathological results
Hacimuftuoglu, Ahmet; Mohammadzadeh, Maryam; Hjoughi, Ali Taghizadehghale; Taspinar, Numan; Togar, Basak; Nalci, Kemal Alp; Okkay, Ufuk; Gundogdu, Betul
Background and Objective: Metformin (MET) has been used as an antidiabetic agent for type II diabetes. At the same time, recent researches have shown that the clinical improvement of MET is useful for nerve damage. In this study, we investigated the analgesic effect of MET in paclitaxel (PAC)-induced neuropathic pain. Materials and Methods: Forty-two adult, female rats, Wistar strain weighing 220 ± 10 g were randomly divided into 5 experimental groups. PAC was intraperitoneally (IP) administered (2.0 mg/kg) for 4 groups every other day (0, 2, 4, and 6 days). By the 30th day, MET (100, 200, and 400 mg/kg) was administered to 4 groups. Before and after treatment, basal pain threshold values were measured with Randall-Selitto analgesiometer test. At the end of experiment, pathological values were measured in selected regions including brain (motor cortex, M1), spinal cord (L4-L5), sciatic nerve, and muscle. Results: According to our results, PAC-induced neuropathic pain reached to highest level at 14th day. Four hundred milligram/kilogram concentration of MET remarkably decreased PAC-induced neuropathic pain. On the other hand, pathologic features have shown that PAC had significant pathological change in the brain and spinal cord while in the peripheral nerves and muscles had not shown any pathological change. Conclusion: The pathological results of the current study for the first time demonstrated that MET beside of its antidiabetic effects reversed neuropathic pain induced by PAC. Consequently, this research can be promising for cancer patients that suffering from neuropathic pain induced by anticancer drugs.
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İncele - MakaleAçık Erişim2022Scopus SJRQ2Precipitation-hardening stainless steels: Potential use radiation shielding materials
Alım, Bünyamin; Özpolat, Özgür Fırat; Şakar, Erdem; Han, İbrahim; Arslan, İbrahim; Singh, V.P.; Demir, Lütfü
In this study, it was focused on the research of new materials with high attenuation efficiency that can be used as radiation shielding material due to the incapability of conventional materials. In accordance with this purpose, the radiation shielding capabilities of four different precipitation-hardening stainless steels (PH-SSs), which are symbolized 15-5PH, 15-7PH, 17-4PH and 17-7PH, were determined both experimentally and theoretically in a wide range of radiation energy. For experimental measurements, two different detectors (Si(Li) and Na(Tl)) and twenty-three different photon energies (from 22.1 to 1332.5 keV) emitted from seven different radionuclides were used in narrow-beam transmission geometry. Phy-X/PSD software were used for theoretical calculations. The theoretically calculated parameters were determined both in the photon energies emitted by the radionuclides used in the experiment and in the continuous energy range of 0.015–15 MeV. Furthermore, in order to make a remarkable assessment of the integration of PH-SSs to nuclear energy applications, the all results obtained have been compared with the corresponding values of Fe-based steel concretes (steel-scrap (SS) and steel-magnetite (SM)), which are widely used as conventional shield materials in nuclear power plants. Moreover, in order to choose the best material to be used in nuclear applications among the PH-SSs, the results were evaluated comparatively in terms of both the characteristics of the materials and the magnitude of the radiation shielding parameters. Consequently, it was concluded that the material with the best radiation shielding performance among the examined PH-SSs was 15-7PH and the radiation shielding performance ranking was generally in the form of 15-7PH ≥ 15-5PH > 17-4PH > 17-7PH > SM > SS. Due to both high attenuation efficiency and superior properties for radiation shielding, it was determined that the PH-SSs can be used as new shielding materials in nuclear applications.
AtıfScopus25WoS25OpenAlex27İncele - MakaleYalnız künye2020Scopus SJRQ2MoO3 reinforced Ultra high molecular weight PE for neutrons shielding applications
Sayyed, M.I.; Abdalsalam, Alyaa H.; Taki, Malaa M.; Mhareb, M.H.A.; Alim, Bünyamin; Baltakesmez, Ali; Şakar, Erdem
Structural, Morphological and neutron attenuation properties of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with molybdenum trioxide composite material obtained by solid state mixing of pellets and powder components via hot pressing have been studied. In this work, Ultra high molecular weight polyethylene and MoO3 has been utilized with different concentration using a hot compression iron mold. The changes in the microstructure of the prepared polymer and its particulate composites were evaluated by SEM. In order to investigate the quantitative of all elements used in these samples, we utilized Energy-dispersive X-ray spectroscopy (EDX) to present the profiles of synthesized samples which show a clear peaks C (carbon), and Mo (Molybdenum). The X-ray diffraction of all samples was examined to study the modification of the phase and lattice for UHMWPE before and after the addition of molybdenum trioxide (MoO3). Raman analysis was utilized to explore the crystallinity, molecular interactions, phase, polymorphy, and chemical structure. This technique is based on non-destructive interaction between light with the chemical bonds inside a material. The Raman spectrum for the current work presented within the range of 150–1600 cm−1. In order to understand the neutron shielding performance for the fabricated UHMWPE with different concentrations of MoO3, 241Am/Be fast neutron source was used to determine the fast neutron radiation equivalent dose rate. The background absorbed dose rate was measured as 0.98 (±0.017) (μSv/h). It was seen that the addition of MoO3 into the UHMWPE enhances the neutron shielding. The dose released from the source was absorbed by 7.71 (±1.3) %, 18.48 (±2.9) %, 22.26 (±2.4) %, 24.07 (±1.8) % and 26.17 (±1.3) % from UHMWPE with 1, 2, 3, 4 and 5% of MoO3 respectively. Additionally, GEANT4 10.02. p01 version was used to calculate total macroscopic cross-sections (TMCS) for the MoO3 doped UHMWPE. According to the results obtained from GEANT4, it was observed that the TMCS values of the UHMWPE increase with increment of the mole fraction of the MoO3 in the structure of UHMWPE examined and that the 5.0% MoO3 sample has the best neutron shielding ability.”
AtıfScopus55WoS54OpenAlex57İncele - MakaleAçık Erişim2022Scopus SJRQ2The Investigation of COD Treatment and Energy Consumption of Urban Wastewater by a Continuous Electrocoagulation System
Dede Sağsöz, Yeşim; Yilmaz, Alper Erdem; Ekmekyapar Torun, Fatma; Kocadağistan, Beyhan; Kul, Sinan
In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 µS cm-1 and chemical oxygen demand of 250 mg L-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.
AtıfScopus6WoS5OpenAlex5İncele - MakaleAçık Erişim2021Scopus SJRQ3Determination of some engineering properties of volcanic tuff using non-destructive method
Can, Ömer
Volcanic tuffs extracted from the quarries of Bayburt province in Turkey are of three different types locally identified as white, yellow and green Bayburt stones. This study was intended to estimate the compressive strength of white, yellow and green Bayburt stones by non-destructive testing methods. For this, non-destructive tests such as the nail penetration test (NPT), Schmidt rebound hammer (SRH) test and ultrasonic pulse velocity (UPV) test were performed. A uniaxial compression test was also performed so as to assess the accuracy of the results obtained from the non-destructive tests. For the NPT, nails manufactured for the gun having 27 and 39 mm length were used. In total, 45 nails were nailed and average the values were taken. Also, uniaxial compressive strength (UCS) and UPV tests were performed on 30 samples in total; furthermore, a total of 60 impacts for the SRH test were performed. The relationship between the results recorded from NPT and UCS, SRH and UPV was determined by regression analysis and comparison. The relative absolute errors between the measured values and the predicted values are below 4% for SRH-NPT comparison and below 9% for UPV-NPT comparison. This method of estimating the compressive strength, by using these non-destructive experiments, was appraised as suitable.
- MakaleYayıncıda açık erişim2020Scopus SJRQ2Comparative analysis of defence response of soybean by seed soaking in gibberellic acid to salinity
Dinler, Burcu Seckin; Gul, Volkan
The present study was conducted to determine the effects of gibberellic acid (GA3) presoaking of soybean (Glycine max L.) seeds on the biomass yield, regulation of reactive oxygen species and some antioxidant enzyme activities in radicle, hypocotyl and cotyledons under salinity. Within this scope, the seeds were subjected to priming with 150 ppm GA3 for 6 h at room temperature. Then, 150 mM NaCl was added in a group and the control was not primed with GA3. The results clearly revealed that salt stress caused a slight induction of biomass yield of radicle and hypocotyl, photosynthetic pigments in cotyledon, reactive oxygen species content in all organs. Moreover, GA3 pretreatment alleviated salt-induced oxidative damage by maintaining superoxide dismutase, ascorbate peroxidase and glutathione reductase enzyme activities in soybean plants. This study firstly elucidates the effects of GA3 priming on the comparative response mechanisms to salinity with different organs of soybean plants.
AtıfScopus3WoS2İncele - MakaleAçık Erişim2020Synthesis of novel polymers containing Schiff base as potential antimutagenic and antimicrobial agents
Nartop, Dilek; Tokmak, Erkan; Özkan, Elvan Hasanoğlu; Kızıl, Hamit Emre; Öğütcü, Hatice; Ağar, Güleray; Allı, Sema
In this research study, two novel polymers including Schiff base were prepared by condensation reaction of polystyrene-A-NH2 with 5-nitro-2-thiophenecarboxaldehyde/or 5-(2-nitrophenyl)-2-furancarboxaldehyde. The synthesized polymers were evaluated using the elemental analysis, infrared spectroscopy (IR), gel permeation chromatography (GPC), thermal gravimetric analysis (TG/DTA). In addition, the antimicrobial and antimutagenic study of the polymers were reported. The antibacterial and antifungal activity were investigated using the diffusion method against pathogenic bacterial strains. PA-TC and PA-FC polymers exhibited the highest antimicrobial activity against the S. typhi H. and P. vulgaris, respectively. PA-FC polymer revealed the highest antifungal activity against C. albicans. The antimutagenic effects were evaluated using the sister chromatid exchange (SCE) and micronucleus (MN) methods against the sodium azide (NaN3) in human lymphocyte cells. The results demonstrated that the PA-FC polymer have strong antimutagenic properties, especially in the concentration of 20 µg/mL.
AtıfScopus10OpenAlex2İncele - MakaleYalnız künye2020Scopus SJRQ2Effects of processing methods and extraction solvents on the chemical content and bioactive properties of propolis
Ecem Bayram, Nesrin; Gerçek, Yusuf Can; Bayram, Sinan; Toğar, Başak
The aim of this study was to evaluate the bioactive properties of propolis extract prepared using different solvents and different extraction methods. The extracts were analyzed by gas chromatography–mass spectrometry (GC–MS) and the differences between their antibacterial activities were evaluated by disc diffusion method. At the same time, bioactive properties of different concentrations of propolis extracts were investigated on human umbilical vein endothelial cells (HUVEC). The proliferative effects and cytotoxic effects of the extracts were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) analyzes, respectively. Total antioxidant capacity (TAC) and total oxidative status (TOS) parameters were used in assessing biochemical effects in the HUVEC cell line. The DNA damage was also analyzed by 8-oxo-2-deoxyguanosine (8-OHdG) level as indicators of genotoxicity. As a result of the MTT analysis conducted within the scope of the present study, the extracts tested were sorted as 95% ethanol extract of propolis (PEE95) > ultrasonic ethanol extract of propolis (PUEE) > 50% ethanol extract of propolis (PEE50) > ultrasonic water extract of propolis (PUWE) in terms of the effectiveness of their cell viabilities. It was observed that high concentrations of PEE95 induced LDH release. In addition to this, our findings have shown that PEE50, PUEE and PUWE increased oxidative stress at high concentrations. According to 8-OH-dG analysis, all tested extracts were found to be non-genotoxic. The results obtained from antibacterial activity and minimum inhibition concentration tests showed that PUEE and PEE95 had stronger antibacterial effects than PEE50 and PUWE. All these results indicated that propolis has beneficial effects for human health and therefore it is a valuable product which can be used as a food supplement.
AtıfScopus23WoS22OpenAlex25İncele - MakaleAçık Erişim2022Scopus SJRQ2What Should Be the Ideal Solvent Percentage and Solvent-Propolis ratio in the Preparation of Ethanolic Propolis Extract?
Kara, Yakup; Can, Zehra; Kolaylı, Sevgi
The biological activity of propolis is mostly due to its polyphenols. Raw propolis is consumed after being extracted in various solvents, ethanol being the most commonly used. However, the ideal percentage and ratio of ethanol for use in the preparation of propolis extracts are uncertain. The aim of this study is to compare the phenolic compositions and antioxidant activities of propolis extracts extracted with different ethanol concentrations and extraction conditions. Two different extraction methods were used, normal and ultrasonic extraction. The propolis extracts were evaluated in terms of total phenolic content, total flavonoid content, ferric reducing/antioxidant power,1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, and phenolic compositions using RP-HPLC–PDA. The propolis extracts with the highest activity were determined beforehand by preparing ethanol–water mixtures at different percentages, ranging from 0 to 99.9%. The most suitable propolis-to-solvent ratio was then determined. The optimum ethanolic percentage varied between 60 and 70%, the ultrasonic extraction process increased the efficiency, and the ideal solvent-propolis ratio (w/v) ranged between 1:5 and 1:10.
AtıfScopus39WoS33İncele - MakaleYalnız künye2021Scopus SJRQ1Orange, red and purple barberries: Effect of in-vitro digestion on antioxidants and ACE inhibitors
Şensu, Eda; Kasapoğlu, Kadriye Nur; Gültekin-Özgüven, Mine; Demircan, Evren; Arslaner, Ayla; Özçelik, Beraat
Bioactive compounds such as phenolics, anthocyanins and carotenoids were investigated in Berberis plant with purple (PB), red (RB) and orange (OB) fruits (barberries). The study was aimed to evaluate the bioaccessibility of the antioxidants and ACE (angiotensin converting enzyme) inhibitory compounds of barberry plants upon their transit through in-vitro digestion. Among barberries, (PB) exhibited the strongest antioxidant activity due to its higher phenolic and flavonoid content. The order of total phenolics and anthocyanins was PB > RB > OB. Chlorogenic acid was the main phenolic compound in all barberries even after in-vitro digestion. All barberries had similar amounts of total carotenoids (4.45 mgβ-carotene/100gDW). After in-vitro digestion, decreasing phenolics, anthocyanins and carotenoids led to a reduced antioxidant activity. Anthocyanins were found the most sensitive compounds in-vitro digestion. In terms of ACE inhibition activity, only RB exhibited ACE inhibition before (73.84%) and after (65.51%) in-vitro digestion. No ACE inhibition activity was detected at all in RB and OB samples. Leaves and branches of Berberis had also over 50% ACE inhibitory activity. To our knowledge, this is the first study on the carotenoids of barberry and the effect of in-vitro digestion on its bioactive compounds and ACE inhibitors.
AtıfScopus30WoS22OpenAlex26İncele - MakaleYalnız künye2022Scopus SJRQ1Seismic behavior assessment of historical Alaeddin Bey Mosque and strengthening suggestions by CFRP fabric and steel plate
Şentürk, İdris; Ergün, Mustafa; Artar, Musa
In this study, the effects of different strengthening methods that can be applied for earthquake-damaged historical masonry structures on structural performance were investigated. For this purpose, the Historical Alaeddin Bey Mosque in the central district of Muş was modeled in three dimensions according to the macromodeling technique using the finite element method in the SAP2000 program. The earthquake performance of the structure was determined by considering the earthquake-acceleration records of Erzincan, Kocaeli, and Van, respectively. The maximum tensile and compressive stresses in all three directions on the structural elements were taken into account as the earthquake behavior parameters of the structure. According to the earthquake analysis made in the time domain, it was determined that the polygonal pulpit of the minaret was at risk of being damaged under the effect of the Erzincan earthquake, and it has been concluded that this region should be strengthened. The damaged area of the minaret was strengthened by the application of CFRP fabric and steel plate materials (together or separately) in five different ways, from inside and outside and at different distance intervals. The conclusions obtained as a result of the earthquake analyses on the reinforced models were examined, and it was explained in detail with the help of tables and graphics that method would be more effective in strengthening such damages.
AtıfScopus40WoS39OpenAlex41İncele - MakaleAçık Erişim2022Scopus SJRQ3Evaluation of four different cogeneration cycles by using some criteria
Karaali, Rabi; Keven, Arzu
The purpose of this article is to evaluate four different gas turbine cogeneration cycles which are basic, absorption cooling, air heating and air fuel heating cogeneration cycles by using the most important six evaluation criteria for different excess air coefficient, different compression rates, and different compressor inlet air temperatures. These six evaluation criteria are electrical heat ratio, exergy efficiency, incremental heat rate, artificial thermal efficiency, fuel energy saving ratio, and specific fuel consumption. It is seen that the air-fuel heating cogeneration cycle is the most efficient among the cycles examined for a certain compressor compression ratio, followed by the air heating, basic, and absorption cooling cycles.
AtıfScopus20WoS18OpenAlex30İncele - MakaleYalnız künye2020Scopus SJRQ1Azo dye-functionalized magnetic Fe3O4/polyacrylic acid nanoadsorbent for removal of lead (II) ions
Sadak, Omer; Hackney, Robert; Sundramoorthy, Ashok K.; Yilmaz, Galip; Gunasekaran, Sundaram
We report the fabrication of a nanoadsorbent for the removal of heavy metals. The nanoadsorbent is comprised of ferric oxide (Fe3O4) magnetic nanoparticles (MNPs) covalently conjugated with polyacrylic acid (PAA) and further functionalized with an azo dye (Congo red, CR) using carbodiimide. This Fe3O4 core and PAA-CR shell system (MNP/PAA-CR) exhibited binding affinity towards various cations (Pb2+, Fe2+, Fe3+, Cd2+, and Cu2+) at room temperature. Using MNP/PAA-CR we studied its heavy metal removal effectiveness and kinetics targeting Pb2+ under various reactions conditions including time and pH. The Pb2+ removal efficiency and adsorption capacity were maximal at pH 6.5 and 45 min of reaction time, and the Pb2+ adsorption kinetics better fit a pseudo second-order model than a first-order model. The adsorption of Pb2+ by MNP/PAA-CR was also investigated by the so-called Langmuir and Freundlich isotherms, and the Langmuir isotherm predicted a maximum absorption of 195.3 mg.g-1. Our results further indicated that MNP/PAA-CR is potentially reusable after desorption of the adsorbed metal with only small decline in adsorption ability over five consecutive cycles of regeneration.
AtıfScopus26OpenAlex17İncele - MakaleAçık Erişim2021Scopus SJRQ1Identification of groundwater potential zones using gis and multi-criteria decision-making techniques: A case study upper coruh river basin (ne Turkey)
Yıldırım, Ümit
In this study, geographic information system (GIS)-based, analytic hierarchy process (AHP) techniques were used to identify groundwater potential zones to provide insight to decisionmakers and local authorities for present and future planning. Ten different geo-environmental factors, such as slope, topographic wetness index, geomorphology, drainage density, lithology, lineament density, rainfall, soil type, soil thickness, and land-use classes were selected as the decision criteria, and related GIS tools were used for creating, analysing and standardising the layers. The final groundwater potential zones map was delineated, using the weighted linear combination (WLC) aggregation method. The map was spatially classified into very high potential, high potential, moderate potential, low potential, and very low potential. The results showed that 21.5% of the basin area is characterised by high to very high groundwater potential. In comparison, the very low to low groundwater potential occupies 57.15%, and the moderate groundwater potential covers 21.4% of the basin area. Finally, the GWPZs map was investigated to validate the model, using discharges and depth to groundwater data related to 22 wells scattered over the basin. The validation results showed that GWPZs classes strongly overlap with the well discharges and groundwater depth located in the given area.
AtıfScopus65WoS52İncele - MakaleYalnız künye2020Existence of solutions for a resonant problem under landesman-lazer type conditions involving more general elliptic operators in divergence form
Ayazoglu, Rabil; Şule Şener, Sidika; Aydın, Tuba Ağırman
The present paper is concerned with the resonant problem −div (a (x, ∇u)) = λ1|u|p −2 u + f (x, u) − g(x) in Ω, where Ω is a bounded domain with smooth boundary in RN (N ≥ 2), p ∈ (1, ∞) and div(a (x, ∇u)) is a general elliptic operators in divergence form. By assuming a Landesman-Lazer type condition and using a variational method based on the Minimum Principle, we show the existence of a weak solution in the Sobolev space W0 1,p (Ω).
- MakaleAçık Erişim2022Scopus SJRQ3Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron
Çolak, M.; Uslu, E.; Teke, Ç.; Şafak, F.; Erol, Ö.; Erol, Y.; Çoban, Y.; Yavuz, M.
Material suppliers typically recommend different additive amounts and applications for foundry practices. Therefore, even in the production of the same standard materials, different results may be obtained from various production processes on different foundry floors. In this study, the liquid metal prepared with the addition of different proportions of a FeSi-based inoculation, which is most commonly used in foundries in the production of a cast iron material with EN-GJL-250 lamellar graphite cast iron, was cast into sand molds prepared with a model designed to provide different solidification times. In this way, the optimization of the inoculation amounts on the casting structure for different solidification times was investigated. In addition, hardness values were determined depending on solidification time in varying amounts of inoculation additions. SolidCast casting simulation software was used to determine the casting model geometry and solidification time. In the scope of the study, sand casting, modeling, microstructure analysis, image analysis, microstructure analysis, and hardness tests techniques were used. When the results are examined, the required amount of inoculation for the optimal structure is optimized for the application procedure depending on the casting module and the solidification time.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ2Free vibration and buckling analysis of functionally graded sandwich beams by Navier's method; [Fonksiyonel derecelendirilmiş sandviç kirişlerin Navier yöntemiyle serbest titreşim ve burkulma analizi]
Turan, Muhittin; Kahya, Volkan
In this study, free vibration and buckling analyses of functionally graded (FGM) sandwich beams is investigated by Navier's method. Displacement field is defined according to the first order shear deformation theory, and the equations of motion are derived by the Lagrange's principle. Volumetric ceramic ratio is defined by a power-law rule. In the analytical solution, different trigonometric series functions are used for each end conditions considered. Two cases of functionally graded sandwich beams are considered: a) Homogeneous ceramic core and FGM faces (Type A), and b) FGM core and homogeneous faces (Type B). Natural frequencies and buckling loads are obtained for different boundary conditions, power-law indices and slenderness. Numerical results are compared with the available literature, and a good agreement are obtained between the results.
AtıfScopus24WoS21OpenAlex16TR Dizin7
İncele - MakaleAçık Erişim2021Scopus SJRQ4The scale of evaluating instruction in pandemic process: Development, validation, and reliability; [Mokymo vertinimo skalė pandemijos procese: Plėtra, pagrįstumas ir patikimumas]
Tutal, Özgür; Kayalı, Bünyami; Yavuz, Mehmet; Hasançebi, Mehmet; Yeşildağ-Hasançebi, Funda
Annotation. The study aims to develop a scale for determining student views on distance instruction, hybrid instruction, and back-to-school process after the pandemic. The study data were obtained from 442 students. EFA and CFA were performed to determine the scale‘s construct validity. Moreover, to decide the data collection tool‘s reliability, item analysis was conducted and internal consistency coefficients were estimated. Based on the results obtained from the validity and reliability analysis of the scale, it can be said that the Scale of Evaluating Instruction in Pandemic Process (SEIPP) is valid and reliable.
AtıfOpenAlex2İncele
