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Koleksiyondaki öğeler
- EditoryalYalnız künye2024Preface
Bayram, Nesrin Ecem; Kostic, Aleksandar Ž.; Gercek, Yusuf Can
- MakaleAçık Erişim2024Scopus SJRQ2TOTAL PHENOLICS, TANNIN CONTENTS, ANTIOXIDANT PROPERTIES, PROTEIN AND SENSORY ANALYSIS OF Pleurotus ostreatus, Pleurotus citrinopileatus AND Pleurotus djamor CULTIVATED ON DIFFERENT SAWDUSTS
Kılıç, Ceyhun; Gürgen, Ayşenur; Yıldız, Sibel; Can, Zehra; Değirmenci, Atiye
In mushroom cultivation, it is important to be aware of the impact of the growing substrate. This study investigated the cultivation of various oyster mushrooms, including Pleurotus ostreatus, Pleurotus citrinopileatus, and Pleurotus djamor, on different types of wood sawdust. Total phenolic content, condensed tannins, antioxidant activity by ferric reducing antioxidant power assay, protein and sensory evaluations were performed in cultivated oyster mushrooms. Wood sawdust of Fagus orientalis (oriental beech), Alnus glutinosa (alder), Castanea sativa (chestnut), and Juglans regia (walnut) were used as substrate for studied mushroom type, separately. Because champignon (Agaricus bisporus) was the most consumed mushroom, it was used as control sample. Methanolic extracts of dried mushrooms were used to measure bioactive characteristics. Pleurotus ostreatus samples cultivated in Alnus glutinosa (alder) sawdust substrate had the highest antioxidant activity. The lowest antioxidant activity values were found in Pleurotus djamor cultivated in Juglans regia (walnut) wood sawdust substrate. The highest protein content was measured in Agaricus bisporus as 13,84 %. The other highest protein concentration was found in Pleurotus ostreatus cultivated in Alnus glutinosa (alder) sawdust substrate, at 13,75 %. The lowest protein concentration belonged to Pleurotus citrinopileatus cultivated in Fagus orientalis (oriental beech) sawdust substrate as 9,86 %. While Agaricus bisporus and Pleurotus ostreatus had the highest overall appreciation score, Pleurotus citrinopileatus had the lowest. It has been observed that the substrate content has an important impact on chemical and sensory properties of the oyster mushrooms. This study provides knowledge on the chemical and sensory characteristics of three different Pleurotus mushroom species cultivated on different composts.
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İncele - MakaleYalnız künye2023Scopus SJRQ1A New Higher-Order Finite Element for Static Analysis of Two-Directional Functionally Graded Porous Beams
Turan, Muhittin; Adiyaman, Gokhan
A new higher-order finite element for the static analysis of two-directional functionally graded (2D FG) porous beams subjected to various boundary conditions based on parabolic shear deformation theory (PSDT) is presented. The main purpose of this study is to predict the deflections and stresses of 2D FG porous and non-porous beams with the help of the proposed finite element. Since a higher-order finite element with a third order polynomial is used, the deflections and stresses can be accurately and rapidly obtained even for short beams. In addition, the new higher-order element is free of shear locking phenomenon without requiring any shear correction factors. Three types of distribution functions were used for porosity in this study. To the author's knowledge, the sinusoidal uneven distribution function (FGP-3) is presented for the first time. The governing equations are derived by Lagrange’s principle using a parabolic shear deformation theory that considers normal and shear deformations. According to a power-law rule, the material change in the beam volume in both directions is defined. The dimensionless maximum transverse deflections, normal stresses, and shear stresses are obtained for various boundary conditions, gradation exponents (px, pz) in the x- and z-directions, porosity coefficient (e), porosity distribution (FGP-1, FGP-2, FGP-3), and the slenderness (L/h). This study's new higher-order finite element gives results compatible with the literature and it can be used to accurately find the deflections and stresses for the 2D FG non-porous or porous beams subjected to various boundary conditions.
AtıfScopus30WoS28OpenAlex26İncele - BildiriAçık Erişim2024Tangential velocity and water vortex structure behaviour based on cylindrical-shaped basin's design parameters for gravitational vortex power plants
Teber, Ahmet
The gravitational water vortex power plants (GWVPPs) have established in hydropower systems as a capable approach, generating micro-scale environment friendly electricity. In this system, energy is produced as a result of the interaction of water coming from an inlet canal with the turbine by creating a vortex in circular/conical-shaped structures. This interaction is based on an assumption that the water flow rate in a basin coincides with the tangential velocity on the turbine propeller. In this case, it is essential to investigate numerous geometric design parameters of the cylinder basin and their effects on vortex formation with the help of Computational Fluid Dynamics (CFD). Here, based on the CFD principles, the behaviour of various geometrical parameters on the vortex and tangential velocities in the basin are investigated separately with the help of Ansys Fluent, without using any turbine propeller. For a certain inlet flow velocity and head, different tunable geometric parameters for the gravitational water vortex plant with a cylindrical basin are inlet canal length, basin diameter, basin height and outlet diameter, respectively. The objective is to achieve an improved design configuration concerning factors such as tangential velocity, vortex arrangement, and the optimal placement of turbine propellers within this vortex.
AtıfScopus1İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3Solidification analysis for variable thickness aluminum castings: simulation and chill design insights
Yilmaz, Galip; Colak, Murat; Uslu, Emin
Manufacturing high-quality casting parts with complex geometries requires high engineering skill and precision. One essential quality concern is isolated hot spots within the castings, often in thick sections. Each hot spot must be consistently fed or mitigated through directional solidification techniques. The impact of various mold sands and the geometry of chill parts on solidification direction was investigated using specialized casting and general-purpose simulation programs. A parametric optimization method was employed to analyze directional solidification to adjust the geometry of the chill parts. The results indicate that employing diverse mold sands to enhance cooling in the thick sections was a viable strategy for achieving directional solidification in parts where the feeding pathway is obstructed due to changes in cross-section. Furthermore, the study revealed that intricate details in the chill part’s geometry are not critical; however, a minimum volume (or weight) was necessary for adequate directional solidification. Lastly, an easily applicable mathematical model has been developed to determine the required volume of chill parts to ensure successful directional solidification.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ2Cheaper, Wide-Band, Ultra-Thin, and Multi-Purpose Single-Layer Metasurface Polarization Converter Design for C-, X-, and Ku-Band Applications
Kaya, Yunus
This article presents the design of wide-band, ultra-thin, and multi-purpose polarization converter utilizing metasurface for C-, X-, and Ku-band applications. Having a topology on a FR-4 substrate with metasurface metallic patterns on the front and an all-metallic surface finish on the back, the unit cell of converter design has symmetry in the (Formula presented.) plane with unique features of having both linear polarization (LP) and circular polarization (CP) property. While the polarization conversion ratio (PCR) of converter in normal incidence case is more than 90% in three different frequency bands of 6.46–6.78 GHz, 10.52–11.85 GHz, and 16.49–17.37 GHz, it shows linear-to-linear polarization feature and a linear-to-circular polarization feature with left-handed circular polarization (LHCP) for the frequency range between 7.28 and 9.40 GHz and right-handed circular polarization (RHCP) for the frequency range between 13.38 and 15.19 GHz. It is also seen that the converter has a PCR value of around 90% for oblique incidence case with incidence angles up to 45 (Formula presented.). Extensive simulations have been conducted to prove the performance of suggested converter with the aid of a commercially-available simulation platform, called CST Microwave Studio. The advantages of suggested polarization converter are low-cost, wide-band, ultra-thin, and having both LP and CP conversion in C-, X-, and Ku-bands.
AtıfScopus13WoS10OpenAlex15İncele - MakaleAçık Erişim2023Scopus SJRQ2Dynamic response of polypropylene honeycomb/polystyrene foam core sandwich composite panels: Experimental and numerical analysis
Caliskan, Umut; Demirbas, Munise Didem; Erdogan, Omer
In this study, dynamically loaded sandwich panels with two different core materials and face sheets made of aluminum alloys (6061-T6) were investigated experimentally and numerically under low-velocity impact. Polypropylene, PP (C3H6)n honeycomb and extruded polystyrene foam, XPS (C8H8)n were preferred as core material. By using the contact force and kinetic energy changes, which were the impact test results of the sandwich panels, the contact and impact resistance was examined. As a result of the tests, damaged regions and permanent central displacement were determined and energy absorption capabilities were demonstrated for two different structures. The results obtained were compared with the results obtained by the open finite element method. In this study, it was shown that the face-sheet thickness of sandwich panels was an important parameter affecting the impact behavior. The behavior of the core material when the face-sheet loses its rigidity was investigated and it was found that polystyrene foam was more effective in preventing impact damage. However, it was found that using the PP honeycomb or XPS was affected the impact behavior in different points.
AtıfScopus10WoS10OpenAlex12İncele - MakaleAçık Erişim2025Scopus SJRQ2The effect of kinesiophobia on gastrointestinal disorders in patients with lower extremity orthopedic surgery
Gunes, Huseyin; Bulbuloglu, Semra; Saritas, Serdar; Ozdemir, Ahmet
Background: Postoperative kinesiophobia and gastrointestinal (GI) disorders are common and undesirable conditions following orthopedic surgery. Additionally, managing both conditions is crucial for preventing complications and accelerating recovery. The purpose of this study is to investigate the effects of kinesiophobia on GI disorders after lower extremity orthopedic surgery. Method: This study was conducted with a descriptive and cross-sectional design. The sample consisted of a total of n = 299 patients who underwent orthopedic surgery in their lower extremities at the orthopedics and traumatology clinic of a research and training hospital located in Turkey. A personal information form, the Tampa Scale of Kinesiophobia (TSK), and the Gastrointestinal Symptom Rating Scale (GSRS) were used to collect data, and the obtained data were analyzed using descriptive statistics, one-way analysis of variance (ANOVA), paired-samples t-test, and post hoc tests when necessary. Results: While 24.4% of the patients were aged 65–74 years, 51.5% were male. The mean total TSK score of the patients was above average (49.36 ± 8.74), while their mean total GSRS score was below average (31.22 ± 11.7). In our study, as kinesiophobia increased, the frequency of bowel movements decreased, and kinesiophobia explained 19.9% of the variance in GI disorders (p < 0.05). Conclusions: Kinesiophobia is a significant predictor of GI disorders in patients who underwent lower extremity surgery. Returning to normal GI function after surgery is crucial for preventing complications in patients with lower extremity surgery. Uncontrolled kinesiophobia after surgery exacerbates GI disorders. Therefore, early diagnosis and management of both kinesiophobia and GI disorders are necessary for rapid recovery in patients with lower extremity surgery. 2025 Gunes, Bulbuloglu, Saritas and Ozdemir.
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İncele - MakaleAçık Erişim2023Scopus SJRQ2Artificial intelligence literacy teaching in social studies education
Yetişensoy, Okan; Rapoport, Anatoli
The increasing role of artificial intelligence (AI) in daily life has led to the emergence of numerous skill sets associated with AI. AI literacy, which is becoming an important citizenship competence, has become a skill that has gained importance in recent years. It is thought that the aim of social studies to prepare students as active citizens of today and the future has made AI literacy a direct subject of social studies education. However, the literature on the relationship between social studies and AI literacy is still scarce. This study aims to explore the relationship between social studies and AI literacy and to discuss the potential role of social studies in teaching AI literacy. In this direction, the concept of AI is defined, and the teaching of AI literacy in education is examined; the teaching of this literacy within the scope of social studies is discussed, and an example of a hands-on activity-supported lesson plan, which can be used in social studies classes, is presented. This study is important in terms of pointing out the potential role of social studies in AI literacy teaching.
AtıfScopus41OpenAlex57İncele - MakaleYalnız künye2024Scopus SJRQ1The Role of Picturebooks in Supporting the Mathematical Knowledge of Preschool Teacher Candidates
Güven Akdeniz, Dilşad
Is children’s literature only beneficial to children? Or do the benefits of children’s literature also extend to the knowledge and mathematical skills of the teachers who employ it and reflect on it? This study seeks to investigate the role of picturebooks on the mathematical knowledge of preschool teacher candidates. For this purpose, in-depth examinations of how picturebooks can be used in teaching preschool mathematics and children’s literature. As well as the changes in the content knowledge of the teacher candidates, were done by conducting focus group interviews with teacher candidates. This is a qualitative case study consisting of focus group discussions in which high-level knowledge sharing and production can be achieved through interaction and associations. In the research, 11 picturebooks were discussed, and 8 teacher candidates participated in 6 focus group interviews lasting a total of 338 min throughout a 7 week period. The study’s findings have demonstrated that through children’s literature, teacher candidates’ misconceptions about measuring length can be revealed and eliminated without the need for another source, with discussions based on consciously and systematically selected picturebooks. Thus, it can be said that picturebooks act as a catalyst for the studies that aim to enhance the mathematical content knowledge of teacher candidates. The study has also observed that picturebooks can comprehensively address the fundamental concepts of length measurement.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ2Comparative evaluation of different drying techniques for beef meat
Kamiloğlu, Aybike; Elbir, Tuğba; Dölek, Muzaffer; Eşrefoğlu, Emine Sedanur
The study aimed to evaluate the influence of different drying techniques (Convective and microwave drying) on beef meat's drying kinetics and color parameters. While drying rates with convective drying vary between.005 and.009 g water/g dry matter, it varies between.014 and.166 g water/g dry matter for microwave drying. Among the model proposed, for the conditions applied in the microwave and convective drying methods, the Midilli model gave a better fit. The Arrhenius-type equation calculated the activation energies of beef samples. Activation energies were 64.15 and 449.86 kJ/mol for convective and microwave drying, respectively. According to measured L*, a*, and b* values and calculated ΔE, C*, and h° values, convective drying at 80°C provided the closest color characteristics to fresh meat. Practical applications: Beef is a perishable food and storage conditions are very important. It is important to have information about the drying methods to be applied in the preservation of these foods in terms of process control. In this study, microwave drying and convective drying methods were examined and it was shown that microwave drying, which is one of the drying methods, shortens the processing time. However, in the convective drying method, color properties similar to the fresh product are provided. This research can provide theoretical guidance for further processing and preservation.
AtıfScopus7WoS7OpenAlex7İncele - MakaleAçık Erişim2024Scopus SJRQ2Eugenol alleviates the negative effects of experimental periodontitis and regulates adipokine hormones in rats
Sevinç Gül, Sema Nur; Özkal Eminoğlu, Didem; Tekçe, Emre; Bayraktar, Bülent; Güven, Leyla; Dilsiz, Alparslan; Yıldırım, Serkan; Sait, Ahmet
A chronic microbial infection that is mediated by the host's immune system is the cause of periodontal disease. As the world's population grows, phytotherapy is a therapeutic strategy that makes use of a renewable resource that can provide less costly medicines. This study aimed to investigate the therapeutic effects of eugenol administration on periodontitis by examining the effects of eugenol at different doses biochemically, histopathologically, and radiologically in rats with experimental periodontitis. Thirty-two Sprague Dawley male rats were divided into four groups: 1. the healthy control group (CG), 2. The experimental periodontitis group (PG), 3. The experimental periodontitis+10 mg/kg eugenol group (EG10), and 4. the experimental periodontitis+20 mg/kg eugenol group (EG20). Alveolar bone loss was measured using micro-CT imaging. The TNF-α, IL-6, leptin, asprosin, and apelin levels were analyzed in the serum samples of rats. Histological and immunohistochemical analyses were performed. The data were analyzed statistically. The serum TNF-α, IL-6, leptin, asprosin, and apelin levels were found to be statistically significantly lower in the eugenol-applied groups (EG10 and EG20) than in the PG (p < 0.05). There was a statistically significant difference in the TNF-α, IL-6, leptin, asprosin, and apelin levels between the EG10 and EG20 (p < 0.05). In the measurements made using micro-CT imaging, alveolar bone loss was found to be at the lowest FR1 level, and in histopathological analysis, the least inflammation was observed in the EG20. It was concluded that the application of 20 mg/kg eugenol in rats with experimental periodontitis was a safe dose, was beneficial in alleviating bone loss, and had a positive effect on the healing process.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2022Scopus SJRQ2The effect of flours of different immature cereal grains on sourdough and sourdough bread: Microbiological, rheological, textural and sugar profiles
Alkay, Zühal; Yılmaz, Mustafa Tahsin; Can, Aslı Muslu; İspirli, Hümeyra; Dertli, Enes
In this study, the utilization of LAB (Lactiplantibacillus plantarum, Levilactobacillus brevis, Furfurilactobacillus rossiae, Weissella cibaria) cultures with selected flours of different immature cereal grains (wheat, barley, oat and rye) on sourdough and sourdough bread was investigated. In total, 16 different sourdough breads were produced and microbiological, pH, TTA and rheological properties of sourdoughs at 0, 8 and 24 h were determined. At the beginning of the fermentation, while sourdoughs showed elasticity, they showed viscoelastic properties after 24 h of fermentation. The sugar profile of cereal grains at the stage of milk formation and the sugar groups presented in EPSs isolated from sourdoughs were revealed by HPLC analysis. The sugar groups in sourdoughs were glucose, xylose and arabinose, while the sugars in the immature cereal grains were glucose, fructose and mannose. The highest EPS production level (1882.69 ± 8.16) was observed in immature barley flour and Lpb. plantarum containing sourdough and all sourdoughs were found to contain glucan type EPSs. It was observed that the amount of EPS produced by the related species differed significantly under different grain conditions. Besides, it was observed that the sourdough breads produced were harder than the control bread. Novelty Impact Statement: Wheat, barley, oat and rye immature grains and four distinct LAB strains were used during sourdough fermentation. Immature grain type and LAB strain used were determinants for in situ exopolysaccharide (EPS) production. Viscoelastic properties of sourdough and textural properties of sourdough bread were affected by grains and LAB strain utilized.
AtıfScopus5WoS2İncele - MakaleAçık Erişim2023Analysis of occupational health and safety risks in beekeeping with fmea method
Özdemir, Mustafa; Kökhan, Serhan
Contrary to popular belief, beekeeping, which dates back to prehistoric times and is one of the most important plant and animal production branches today, is not an innocent profession in terms of occupational health and safety. In this study, in order to determine the occupational health and safety risk factors in the beekeeping profession, Interviews with beekeepers were conducted in 10 apiaries operating in Bayburt, where especially wandering beekeeping is practiced. In light of the data obtained from the danger hunt applied by the occupational health and safety specialist, ergonomic, physical, biological, and chemical risks were revealed using the FMEA risk analysis method. The effect, probability, and detection values were found for each failure mode, and then Risk Priority Number values were calculated. As a result of the study, for the five basic stages of beekeeping, 15 processes, 39 failure modes, 72 potential effects, and 39 failure causes were determined. Failure modes with a Risk Priority Number value of 100 and above were evaluated as “situations where urgent action and axiom should be taken,” and preventive axioms were proposed for each relevant failure mode. The number of studies on the risk factors in the beekeeping profession is very limited in the literature. For this reason, it is predicted that this study will fill an important gap in the related field and make significant contributions to the literature.
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İncele - MakaleAçık Erişim2024Olive Oil Production Forecasts for a Macro Perspective during 2024–2027
Kurtoğlu, Seval; Uzundumlu, Ahmet Semih; Gövez, Elif
Olive oil, which is part of the Mediterranean diet, is one of the most important foods for a healthy diet. The number of countries that produce these important foods has not increased significantly over the years. However, the number of exporting countries tripled in the same period. This study aimed to predict the countries that will lead olive oil production globally between 2024 and 2027 by using the production data from the period 1961–2023. The data were analyzed using the ARMA model in the statistical program SAS. According to the results for the 10-year period of 1961–1970, there were 25–26 olive-oil-producing countries in the world. Approximately 31.26% of olive oil production was in Italy, 28.32% in Spain, 13.14% in Greece, 7.80% in Turkey, and 5.74% in Portugal. According to the average production for the period 2024–2027, it is estimated that 34 and 35 countries will produce olive oil, with 29.93%, 9.08%, 9.06%, 9.00%, and 8.90% of the world’s production provided by Spain, Greece, Turkey, Morocco, and Italy, respectively. These five countries account for 65.96% of the world’s production level. The estimation results of this study found that there are many exporting countries other than the leading producer countries thus showing that the producer countries do not have a forceful marketing concept, and therefore intermediaries emerge. For this reason, producer countries such as Turkey, Tunisia, and Morocco, which are not very competent in marketing, will have more say in the market by using their resources more effectively and making more effective strategies with an improved production and marketing approach.
AtıfScopus27WoS28OpenAlex30İncele - MakaleAçık Erişim2023Scopus SJRQ4Theoretical Investigation of (E)-1-(2,4-Dichlorophenyl)-3-[4-(morpholin-4-yl)phenyl]prop-2-en-1-one Molecule As a Possible Potential COVID-19 Drug Candidate: Molecular Docking and DFT Calculations
Ekíncíoğlu, Yavuz
Abstract: In this study, a potential new drug to fight against the COVID-19 virus, (E)-1-(2,4-dichlorophen-yl)-3-[4-(morpholin-4-yl)phenyl]prop-2-en-1-one molecule has been investigated via computational assessment and molecular docking approach. From the conformer analysis and optimization, the most stable structure is determined. For this structure, geometrical parameters, Frontier molecular orbitals analysis, chemical reactivity descriptors, nonlinear optical properties, natural bond orbital, mulliken population analysis, molecular electrostatic potential map and thermodynamic properties of molecule were calculated with standard functional at the B3LYP/6-311++G(d,p) method. The geometric parameters (bond lengths and bond angles) are in good agreement with the experimental values available in the literature. The stability, structural and electronic properties obtained for the molecule can be a significant contribution to the future experimental and theoretical studies. The molecular docking mechanisms between the molecule and 7ALI protein points out that the protein-ligand systems are hydrogen bonding, π-stacking, and hydrophobic interactions.
AtıfScopus4WoS4OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ2Antioxidant properties and aldose reductase inhibitory potency of Viscum album L. extracts: experimental and computational insights
Akyüz, Bilal; Şengül, Bülent
This study systematically investigates the antioxidant capacity and inhibitory impact of Viscum album L. plant extracts on the aldose reductase (AR) enzyme through a combined approach of in vitro and in silico methods. Various sections derived from distinct plant parts were examined, revealing potent inhibitory potential. Notably, the methanol extract sourced from the plant’s stem displayed remarkable efficacy with an IC50 value of 0.156 µM. Total phenolic content and antioxidant capacity analyses were conducted, highlighting variations across plant parts and solvent types. Qualitative and quantitative phenolic compound content in the extracts was elucidated by LC-MS/MS analysis, revealing higher levels of quinic acid, fumaric acid, and chlorogenic acid. Molecular docking studies further substantiated the inhibitory roles of key compounds like chlorogenic acid and fumaric acid, elucidating their interactions with specific amino acid residues within the AR enzyme’s active site and shedding light on the underlying mechanisms. Collectively, this study underscores Viscum album L. extracts as promising candidates for aldose reductase modulation. By merging experimental and computational techniques, the study presents a holistic understanding of natural compound interactions, potentially influencing drug development and herbal therapeutics.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2The Toughness of Polypropylene Fiber-Reinforced Foam Concrete under Various Uni- and Tri-Axial Compression Loads
Gökçe, H.S.; Öksüzer, N.; Kamiloğlu, H.A.; Eyüboğlu, M.; Yılmaz, F.
Foam concrete has recently become a key construction material in terms of meeting the special needs of modern engineering applications such as thermal insulation, absorption of static and dynamic loads. In this study, the effect of polypropylene fiber content and various uni- and tri-axial compression loads on the toughness response of polypropylene fiber-reinforced foam concrete was investigated. Up to a certain strain level (0.1 mm/mm), the ultimate compression stress of specimens under uni- and tri-axial loading increased from about 1 MPa to 16 MPa with the increased target densities of foam concrete. There was a strain-hardening capability of low-density foam concrete while the specimens failed by strain-softening in the high-density series. The optimum fiber amounts were found to be 3.9%, 4.6%, and 6.4% for low, medium, and high target densities of foam concrete, respectively. At low-density series, the bubbles were observed to be relatively bigger and mostly merged with each other. A reduction in foam content (vice versa, increasing target density of mixture) and the presence of fiber resulted in smaller pore size and a more homogenous distribution of them in the matrix. In conclusion, the desired pore structure and efficient bridging of fibers in the matrix allowed the production of favorable foam concrete with higher toughness.
AtıfScopus14WoS10OpenAlex14İncele - MakaleYalnız künye2024Scopus SJRQ3Exponential Convex Functions with Respect to s
Kadakal, Mahir
In this paper, we study the concept of exponential convex functions with respect to s and prove Hermite-Hadamard type inequalities for the newly introduced this class of functions. In addition, we get some refinements of the Hermite-Hadamard (HH) inequality for functions whose first derivative in absolute value, raised to a certain power which is greater than one, respectively at least one, is exponential convex with respect to s. Our results coincide with the results obtained previously in special cases.
AtıfScopus1WoS2İncele - MakaleAçık Erişim2025Scopus SJRQ3Effect of Thermal Modification and Picture Varnish Application on Color Change of Scots Pine (Pinus Sylvestris L.) Wood
Peker, Hüseyin; Ayata, Ümit; Ulay, Göksel
Scots pine is one of the important tree species used by the wood processing industry in many countries for both interior and exterior applications. It is well known that thermal treatment alters the color of wood. To protect wood from outdoor environmental conditions, certain chemicals are applied to its surface. These protective chemicals also influence the color of thermally treated wood. In this study, the color-altering effect of picture varnish (refined linseed oil), commonly used as a protective chemical in the field of painting, was investigated on both thermally treated and untreated wood materials. Scots pine (Pinus sylvestris L.) wood samples were subjected to thermal treatment at 212 °C for 2 h. Following this, varnish made from refined linseed oil was applied to some of these samples and some untreated samples, with the remaining untreated samples used as controls. Color and whiteness index (WI*) values were analyzed on the resulting four different materials, and the results were compared. Analysis of variance showed significant effects for the factors of heat treatment, picture varnish application, and their interaction, on WI* (|| and ⊥), a*, L*, ho, b*, and C* values. In the non-heat-treated samples, the application of varnish resulted in reductions in WI* values in both directions and in L* values, while increases were observed in ho, b*, C*, and a* values. Additionally, the application of varnish to the heat-treated samples resulted in an increase in a* values, while reductions were observed in WI* values in both directions, as well as in ho, L*, b*, and C* values. After heat treatment, the ∆E* value for Scots pine wood was calculated as 33.63. For both heat-treated and non-heat-treated samples, varnish application resulted in negative ∆L* values and positive ∆a* values. Additionally, ∆b* and ∆C* values were positive in the non-heat-treated and varnished samples, while they were negative in the heat-treated and varnished samples. The protective picture varnish used in the study significantly altered the color of both thermally treated and untreated wood.
