Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(116)
- Şahin, Engin(48)
- Kaya, Yunus(46)
- Özen, Soner(46)
- İspirli, Hümeyra(45)
- Pat, Suat(44)
- Şenay, Volkan(42)
- Korkmaz, Şadan(36)
- Yilmaz, Mustafa Tahsin(33)
- Kutlu, Naciye(32)
- Cuce, Erdem(31)
- Öner, Erdal(31)
- Artar, Musa(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Mercan, Emin(28)
- Bayraktar, Bülent(27)
- Bayram, Sinan(27)
- Can, Zehra(25)
- Ecem Bayram, Nesrin(25)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Ayata, Ümit(21)
- Bayram, Ozkan(21)
- Dirican, Ebubekir(20)
- Abdioglu, Murat(19)
- Ayazoglu, Rabil(19)
- Birinci, Ahmet(19)
- Kamiloğlu, Aybike(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Tozlu, Alperen(18)
- Gul, Volkan(15)
- Hasar, Ugur C.(15)
- Kadakal, Mahir(15)
- Sagdic, Osman(15)
- Ergün, Mustafa(14)
- Kadakal, Huriye(14)
Yayınlar
- Derleme MakaleAçık Erişim2021Scopus SJRQ2Investigation of the Effect of Inoculant and Casting Temperature on Fluidity Properties in the Production of Spheroidal Graphite Cast Iron
Çolak, Murat; Kaya, Sinan
Working with liquid metal makes the casting method very advantageous, but also presents some difficulties. One of the common challenges in the casting process is that the liquid metal may not fill the mold cavity completely. This is mainly due to the contact of the liquid metal with the mold surface in the mold cavity, the high heat transfer coefficient of the mold material, and the undercooling and solidification of the liquid metal during liquid movements. For this reason, the fluidity of the liquid metal is important for robust casting production. The fluidity is affected by many factors such as mold properties, casting temperature, and alloying elements. In this study, it is aimed to investigate the fluidity characteristics of GGG60 alloy. For this purpose, the effects of casting temperature, different inoculants, and different inoculant quantities were used in the new mold design, which has different cross-sectional thicknesses. The distance of the alloy in the cavities was also compared with FlowCast Casting simulation software.
AtıfScopus8WoS8OpenAlex9
İncele - MakaleAçık Erişim2021Scopus SJRQ2Photoluminescence and structural properties of zirconium dioxide thin films produced by RF sputtering technique
Bakacak, Pinar K.; Gur, Emre; Bayram, Ozkan; Tuzemen, Sebahattin; Simsek, Onder
In this study, Zirconium Oxide (ZrO2) thin films were produced by using radio frequency magnetron sputtering method on glass substrate at various pressures. The effects of growth pressure on the characteristics of grown Zirconia nanostructures were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Uv-Visible Spectroscopy and Photoluminescence Spectrometry (PL). XRD analysis showed that peaks of the monoclinic and tetragonal phases were more effective at low growth pressure, but different monoclinic phase peaks were present at increasing growth pressures. The surface morphological properties of the films such as average and maximum roughness, changed significantly with increasing growth pressure, and the maximum peak height first increased to 40 nm and then decreased to 20 nm. The optical transmittance of these thin films was examined in the 450–1100 nm wavelength range, covering both the visible and near-infrared spectral range, and it was found to be approximately 95% at 550 nm wavelength, and the optical band gaps were calculated to be approximately 3.26 eV by PL analyses. Uv-Visible spectroscopy analysis showed that the refractive index of the Zirconia films decreases from 2.09 to 1.79 with increasing wavelength of the incident photon. ZrO2 thin films are considered potential materials for transparent electronic devices because of their high transmittance value.
AtıfScopus5WoS4OpenAlex5İncele - MakaleAçık Erişim2021Scopus SJRQ1Antioxidant, antimicrobial activities and fatty acid compositions of wild berberis spp. by different techniques combined with chemometrics (PCA and HCA)
Gıdık, Betül
Interest in medicinal plants and fruits has increased in recent years due to people beginning to consume natural foods. This study aims to investigate the total phenolic flavonoid content, antiox-idant activity, condensed tannin content, oil content, and fatty acid compositions of five local breeds of Berberis spp. from Bayburt, Turkey, and their antioxidant and antimicrobial activities. The fatty acid composition of samples was performed with gas chromatography-mass spectrometry (GC-MS), and the total fatty acid content of samples was between 6.12% and 8.60%. The main fatty acids in Berberis spp. samples were α-linolenic acid (32.85–37.88%) and linoleic acid (30.98–34.28%) followed by oleic acid (12.85–19.56%). Two antioxidant assays produced similar results, demonstrating that extracts of wild B. vulgaris L. had the highest ferric reducing antioxidant power (FRAP) (621.02 µmol FeSO4.7H2O/g) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) (0.10 SC50 mg/mL) values. According to principal component analysis (PCA), four components were determined. In addition, two main groups were determined according to hierarchical cluster analysis (HCA), and wild and culture of B. vulgaris L. were in different subgroups. This is the first original report about the fatty acid composition and oil content of Berberis spp. grown in Bayburt, Turkey. The obtained results indicate that B. integerrima Bunge and B. vulgaris, which have especially remarkable fatty acid content, antioxidant, and antimicrobial activity, could be potential sources for these properties in different areas of use.
AtıfScopus45WoS41OpenAlex48
İncele - MakaleAçık Erişim2021Scopus SJRQ1Investigation of time-history response of a historical masonry minaret under seismic loads
Yurdakul, Muhammet; Yılmaz, Fatih; Artar, Musa; Can, Ömer; Öner, Erdal; Daloğlu, Ayşe T.
This study presents an investigation of the seismic performance of a historical masonry minaret which was built in the 12th century in Bayburt. The minaret was built as masonry with regional stones and handmade bricks. The most important feature of the minaret is its longitudinally conical geometry. An experimental investigation was made to obtain the mechanical properties of the regional stone used in the historical minaret. A three-dimensional Finite Element Model of the historical minaret was created in SAP2000. Three earthquake ground motions such as Erzincan, Kocaeli-Duzce, and Van-Ercis were used to investigate the seismic performance of the historical minaret. The results show that Erzincan, Kocaeli-Duzce and Van-Ercis earthquakes may cause some damages in the same zone of the minaret body since the tensile stresses occurred due to the earthquakes exceed the limit tensile stress of the masonry brick. The use of the data obtained from the experimental investigation of the Bayburt yellow stone in the analysis is important for the reliability of the results.
AtıfScopus44WoS43OpenAlex44İncele - MakaleAçık Erişim2021Scopus SJRQ1Development of buffalo milk ice-cream by high pressure-homogenisation of mix: Physicochemical, textural and microstructural characterisation
Sert, Durmuş; Mercan, Emin; Kılınç, Mehmet
This study aimed to determine the physicochemical, textural, and microstructural characteristics of buffalo milk ice cream produced from high-pressure homogenisation (HPH) treated ice cream mix. Ice cream mix was subjected to 0 (control), 30, 60, 90, 120, or 150 MPa. HPH increased the firmness and consistency value of mixes, whereas it decreased cohesiveness and index of viscosity values. Also, HPH improved the lightness, redness, and yellowness of the mix. The mean particle size of HPH-treated mix samples was lower than the control, except HPH-150. The hardness of ice cream samples was between 14.30 and 77.81 N, in which HPH increased hardness value with the increasing pressure. The overrun of ice cream samples ranged from 19.93 to 45.15%, and HPH decreased it. HPH significantly improved resistance to melting in the ice cream. Scanning electron microscopy images revealed that HPH reduced the size of air bubbles. HPH at 150 MPa resulted in a foamy structure in the ice cream. HPH can alter the hardness, microstructure, and melting characteristics of buffalo milk ice cream. Products with improved properties may be developed by further modifying the formulation and processing parameters.
AtıfScopus22WoS16OpenAlex20İncele - MakaleAçık Erişim2021Scopus SJRQ1Investigation of mechanical properties of high-performance hybrid fiber concretes adding nanomaterials using with coarse aggregate
Öksüzer, Nurullah; Anil, Özgür; Aldemir, Alper; Şahmaran, Mustafa
High-performance hybrid fiber cement composites have more ductility and higher strength than traditional concrete. This is because crack development is limited due to multiple small cracks are formed instead of a single large crack as the fibers enter the matrix. It is customary to produce these concrete composites with fine aggregates. In this study, concrete composites with coarse aggregates were strived to be produced to gain some feasibility. To this end, different mixtures composed of different aggregate/binder ratios and different fly ash/binder ratios were designed. In order to compare the effectiveness of the combination of different fibers were utilized in these mixtures. The volumetric ratios of fibers (excluding reference samples) were kept constant at a value of 2%. For each mixture, four-point bending and compressive tests were performed. The increase in the aggregate ratio was observed to cause a more ductile flexural behavior in mixtures composed of PVA and steel fibers. In contrast, the ductility was reduced in mixtures with Nylon-mono and steel fibers. In addition, the ductility values were enhanced with the increase in FA/PC ratio. In addition, the possibility to use the cheaper Nylon-mono fibers in hybrid fiber mixtures was proved with optimization of aggregate-binder (A/B) and FA/PC ratios, enabling more feasible high-performance concrete mixtures.
AtıfScopus12WoS9OpenAlex13İncele - MakaleAçık Erişim2021Scopus SJRQ3Effect of Heat Treatment on Shore-D Hardness of Some Wood Species
Esteves, Bruno; Sahin, Sırrı; Ayata, Ümit; Domingos, Idalina; Ferreira, José; Gürleyen, Levent
Hardness is an important wood property for several applications. Typically, it is necessary to use traditional methods, such as a universal test machine, to determine a wood’s hardness value. This work reports the hardness of some wood species before and after heat treatment (ThermoWood method) using the Shore-D hardness method. The Shore-D hardness value of untreated wood ranged between 35.3 for Limba wood and 77.2 for Santos wood. With heat treatment, hardness decreased, and the decrease was greater for samples that underwent harsher treatment (2 h at 212 °C). The decrease of hardness was highest for Sipo wood (14%) and the lowest for Afrormosia wood (2.5%). Analysis of variance tests showed that there was a significant difference between wood species, heat treatment, and the interaction between both variables at the chosen level of significance (P ≤ 0.05). Results showed that Shore-D hardness could be used to measure hardness directly in a production line or in small wood companies without using a universal test machine.
AtıfScopus23WoS17OpenAlex24İncele - MakaleYalnız künye2021Scopus SJRQ3Two-dimensional frictionless contact analysis of an orthotropic layer under gravity
Öner, Erdal
An analytical method for solving the two-dimensional frictionless continuous contact problem of an orthotropic layer pressed by a rigid stamp is presented in this paper. The orthotropic layer lies on a rigid foundation, and plane-strain orthotropy prevails in the layer, which is not bonded to the rigid foundation. An external load was applied to the orthotropic layer through a rigid stamp. The profiles of flat and cylindrical stamps as stamp shapes were handled separately. The orthotropic layer was assumed to be subjected to uniform vertical body forces owing to the effect of gravity. For values of the resultant compressive force P acting on the stamp vertically that were lesser than a critical value, the continuous contact along the orthotropic layer–rigid foundation interface was maintained. By assuming plane-strain conditions, the governing equations corresponding to the mentioned contact problem were extracted separately in the presence and absence of the body force of the orthotropic layer using the theory of elasticity and the Fourier integral transformation technique. Subsequently, the mixed boundary value problem was reduced to a singular integral equation, and the numerical solution of this singular integral equation was obtained by applying the Gauss–Chebyshev integration formulas. Numerical results reveal the effect of the orthotropic material parameters, stamp length (in the case of a flat stamp), stamp radius (in the case of a cylindrical stamp), applied load on the contact stress distributions, contact length, initial separation load and initial separation distance. The results of this study may provide insights for engineers in fields closely related to contact mechanics.
AtıfScopus29WoS29OpenAlex26İncele - MakaleAçık Erişim2021Scopus SJRQ2Magnetic levitation force performance of benzil added bulk MgTi0,06B2 superconductors
Abdioglu, Murat
MgB2 superconductors can be proposed as a good candidate for Maglev systems due to their superior structural and superconducting properties. Besides, magnetic levitation and guidance force properties of these superconductors should be increased for commercial applications of Maglev systems. Therefore, the critical current density and magnetic levitation and guidance force properties of MgTi0.06B2 superconducting samples were investigated in this study, at measurement temperatures of 20 K and 25 K, depending on benzil (C14H10O2) addition in different adding amounts of 0, 1.5, 3, 4.5, 6 and 9 wt%. In addition to benzil, nanometer-sized silver particles were added to the samples in a constant ratio of 2 wt% to enhance the structural properties. The maximum critical current density values increased from 67 kA/cm2 for pure sample to 92 kA/cm2 with benzil adding amount of 3 wt% at T = 20 K, indicating an increment of 37%. In addition, the levitation force in ZFC (zero field cooling) regime and the guidance force in FC (field cooling) regime at 20 K increased at an amount of 46% and 57%, respectively, with 3% benzil addition. It can be said that the suitable amount of benzil addition as a carbon source produces additional pinning centres inside the MgTi0.06B2 and thus structural properties, critical current density and therefore, magnetic levitation properties of the samples are increased.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2021Scopus SJRQ1An investigation of the fatigue performance of adhesively bonded step-lap joints: An experimental and numerical analysis
Gavgali, Esma; Sahin, Resul; Akpinar, Salih
Adhesively bonded joints are used in many engineering applications and are manufactured by joining various materials together. Static and dynamic analysis of adhesively bonded joints is very important in both scientific and sector studies on these joints. In this study, the static and fatigue strengths of single-lap joints (SLJs) and three-step-lap joints (TSLJs) that were subjected to tensile and four-point bending tests were examined experimentally and numerically. Adhesively bonded joints were produced using DP460 toughened type adhesive and AA2024-T3 aluminum alloy was used as the adherent. Fatigue tests were performed at a loading ratio (R) of 0.1 and a frequency of 10 Hz. As a result, applying a step-lap to the overlap area of adhesively bonded joints considerably increased the tensile static and fatigue strength of the joint. For the single-lap joint, both the static tensile and the tensile fatigue lifetime limit value of the three-step-lap joint increased approximately 100%. One of the reasons for that increase was that the moment effect formed in single lap joints due to the eccentric loading is minimized and the other is that a step-lap applied to the overlap area retards the formation of damage. However, static bending and fatigue strength values of TSLJs significantly decreased compared to those of SLJs. In addition, the results of the experimental and numerical analyses were found to be highly compatible with each other.
AtıfScopus29WoS28OpenAlex35İncele - MakaleAçık Erişim2021Scopus SJRQ3The influence of metallostatic pressure, grain refiner, and modification on the critical solid fraction (CSF) of cast A380 alloy
Çolak, Murat; Dispinar, Derya
In this work, porosity formation with regard to the change in the metallostatic pressure was investigated. Different geometry was generated to simulate the effect of pressure on critical solid fraction. A380 alloy was sand cast. Additionally, the effect of grain refiner and modifiers was also investigated. Samples were subjected to X-ray radiography and density measurement to quantify the pore size and distribution.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2021Scopus SJRQ1An embedded mixed method study on teaching algebraic expressions using metacognition-based training
Öztürk, Mesut
That the students are aware of the learning process and know how they learn is important in terms of both controlling their previous learning and building their new learning on the previous ones. This thinking process, which generally requires metacognitive skills, may facilitate the difficulties experienced by the students while passing on from arithmetic to algebraic thinking. This study had two purposes:(1) to examine the effect of the IMPROVE method, a metacognitive training method, on the academic achievement of middle school students regarding algebraic expressions and (2) to examine the teaching process of algebraic expressions with IMPROVE. This study was conducted as an embedded mixed design. Forty-nine sixth grade students participated in the quantitative part of the study, while only six students from the experimental group participated in the qualitative part. The quantitative results of the study showed that there was a significant difference between the students’ total achievement scores regarding algebraic expressions and the achievement scores in the questions requiring high-level thinking skills in favor of the experimental group. It has been found in the comparisons made based on cognitive field levels that there is a statistically significant difference in favor of the group that received metacognition-based education in synthesis level questions. The qualitative results indicated that this teaching method increased students’ interest, contributed to their conceptual learning and improved their various affective characteristics. Also, it has been determined that the students who receive metacognition-based education do enjoy learning with this teaching method and that they think this method should be sustainable for the upcoming lessons.
AtıfScopus15WoS10OpenAlex22İncele - MakaleAçık Erişim2021Scopus SJRQ13D-graphene-laser patterned p-type silicon Schottky diode
Orhan, Elif Oz; Efil, Esra; Bayram, Ozkan; Kaymak, Nuriye; Berberoğlu, Halil; Candemir, Ozun; Pavlov, Ihor; Ocak, Sema Bilge
The influence of the laser patterning (LP) process on the quality of graphene (Gr) film and Schottky diode characteristics was researched in this study. First of all, p-type silicon (Si) was patterned by homemade femtosecond laser source. To compare the resulting effect, non-patterned n-Si and p-Si were used as substrates. To achieve vertically oriented three-dimensional (3D) Gr nanosheets (VGNs) onto the laser patterned p-type Si, non-patterned n-Si, and p-Si substrates, we used Radio-Frequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) technique. Then, Raman analyses for VGNs obtained on patterned and non-patterned p-Si and n-Si substrates were conducted. All results indicate that the Gr obtained on all substrates is vertically oriented. Scanning electron microscopy (SEM) analyses were also performed to obtain information about the morphological properties of the 3D Gr structure. In addition, the influence of the laser patterning at the Gr-Si interface was evaluated by comparing two sets of devices which are junctions of Gr-Laser Patterned Si (Gr-LPSi) and Gr-Insulator-Silicon (Gr-I-Si) at 300 K in the dark medium. D1 device consists of a Gr-LPSi junction that involves RF-PECVD grown Gr on the silicon, whose surface exposed the laser beam for patterning. D2 device consists of a Gr-I-Si junction that involves RF-PECVD grown Gr onto the silicon, whose surface involves a thin native oxide layer (~2 nm). The results show that the laser treatment causes an increment in Schottky barrier height (SBH) and decreases leakage currents under a reverse bias voltage of the diode. Notably, we have seen the influence of the laser patterning process on 3D Gr nano-sheets which is that the entire surface of the substrate has now reformed new structures in the nano-sphere and nano-rose morphology, so we believe that this is the first work that shows these structures in this form.
AtıfScopus14WoS13OpenAlex13İncele - MakaleAçık Erişim2021Scopus SJRQ3Determination of radioprotective and genotoxic properties of sulfamide derivatives
Aygün, Bünyamin; Alaylar, Burak; Aklncloǧlu, Akln; Allm, Bünyamin; Kocaman, Ebu Talip; Karadayl, Mehmet; Abu Al-Sayyed, Mohammed Ibrahim; Aksu, Seyma; Sakar, Erdem; Özpolat, Özgür Flrat
Some potential drug active substances with the ability to reduce the effects of radiation on human tissues and cells were investigated. For this purpose, eight different types of sulfamide derivatives were synthesized and nuclear radiation protection parameters were determined. Neutron radiation reduction parameters such as the half-value layer effective removal cross-sections, mean free path, and the number of particles passing through the sample were determined with GEANT4 code. Additionally, the gamma radiation attenuation parameters of the materials examined were determined using Phy-X/PSD software in the energy area of 0.015-15 MeV. These parameters are the half-value layer, mass attenuation coefficient, mean free path, exposure buildup factor and effective atomic number. Neutron radiation absorption experiments were applied using an 241Am-Be fast neutron source. All results obtained for neutron radiation were compared with paraffin and water. It has been found that the ability of sulfamide derivatives to absorb these radiations is superior to reference materials. To determine whether these derivatives could have adverse effects on human health, their genotoxic potential was determined using the Ames/Salmonella bacterial reversion test. The results showed that these derivatives can be considered genotoxically safe in tests at concentrations up to 5 mM. Thus, it is suggested that the derivative materials examined in this study can be used as active substances for a drug to be made for protection against both neutron and gamma radiation.
AtıfScopus10WoS9OpenAlex11İncele - MakaleYalnız künye2021Scopus SJRQ3Synthesis of silver nanoparticles prepared with a dextran-type exopolysaccharide from Weissella cibaria MED17 with antimicrobial functions
İspirli, Hümeyra; Sagdic, Osman; Dertli, Enes
Microbial polysaccharides can find distinct applications as stabilizer agents including synthesis of nanoparticles. In this study, a dextran-type exopolysaccharide (EPS) was used as the stabilizer agent for the green synthesis of silver nanoparticles (AgNPs-Dex) with antimicrobial characteristics. UV–vis spectroscopy analysis was used to test the formation of AgNPs-Dex. The uniform morphology at around 10 nm size was observed for AgNPs-Dex by TEM analysis and importantly EDX analysis demonstrated the embedment of Ag+ ions within dextran as the stabilizer agent. XRD analysis confirmed the crystalline nature of AgNPs-Dex and FTIR analysis demonstrated the interactions of dextran functional groups with silver. DSC and TGA analysis showed the alteration in the thermal stability of AgNPs-Dex compared to the stabilizer dextran. The antibacterial and antifungal activities of AgNPs-Dex were determined against food originated pathogenic bacteria and fungi and important inhibition levels were observed at 1 mg ml−1 concentration of AgNPs-Dex and this activity was observed to be concentration dependent.
AtıfScopus17WoS13OpenAlex15İncele - MakaleAçık Erişim2021Scopus SJRQ2Production, purification, and characterization of Streptomyces sp. strain MPPS2 extracellular pyomelanin pigment
Bayram, Sinan
Melanins are natural pigments widely distributed in nature from bacteria to humans. These complex, negatively charged, amorphous, high molecular mass natural biopolymers have many different bioactive properties such as antimicrobial, antiviral, antioxidant, liver protective effects, etc. In this study, some chemical and physical properties of the purified extracellular pyomelanin pigment were investigated via XRD (X-ray diffraction), FT-IR (Fourier transform infrared), and 1H NMR (Nuclear magnetic resonance). Additionally, the melanin pigment producer Streptomyces sp. strain MPPS2 was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) and 16S rDNA sequence analysis. 16S rDNA nucleotide sequence analysis result was deposited in NCBI GenBank® under accession number MT825616.
AtıfScopus28WoS22OpenAlex27İncele - MakaleAçık Erişim2021Scopus SJRQ3Tarragon (Artemisia dracunculus l.) could alleviate negative effects of stocking density in laying hens
Kaya, H.; Karaalp, M.; Kaynar, Ö.; Tekçe, E.; Aksakal, A.; Bayram, B.
The study was conducted to determine the effects of stocking density (SD, 5 or 7 layers/cage) and tarragon (Artemisia dracunculus L.) diet supplementation at four levels (0, 1.2, 6 and 12 g/kg feed) on performance, certain egg characteristics, serum, liver, egg yolk and small intestine bacteria parameters in laying hens. The experiment was carried out over a period of 8 weeks, with 192 Lohman Brown commercial hybrids at 50-w-age. The results showed that an increased SD reduced feed intake (FI; p<0.01) and egg production (p<0.05), but had no effect on the weight gain, feed conversion ratio, damaged egg ratio, egg weight and egg quality (p>0.05) parameters. The supplementation of tarragon to the diet reduced the FI and damaged egg ratio (p<0.01), and improved egg production and FCR (p<0.01). While an increased SD reduced serum total antioxidants (p<0.05), it elevated corticosterone (CORT) and total oxidant serum (TOS) (p<0.05). Tarragon was found to enhance total immunoglobulin (p<0.05), but to decreased the CORT and TOS of the serum (p<0.05). An increased SD raised the malondialdehyde (MDA) in the serum (p<0.001), liver (p<0.05) and yolk (p<0.001). Tarragon supplementation reduced MDA of the serum (p<0.05), liver (p<0.001) and yolk (p<0.001). E. coli and total Mesophilic Aerobic Bacteria counts in the small intestine were raised (p<0.001) with increased SD. Tarragon decreased (p<0.05) mesophilic aerobic bacteria. It was thus found that, tarragon supplementation can be considered generally effective in improving performance parameters, alleviating stress-induced negativities, reducing lipid peroxidation, regulating the immune system and controlling some intestinal microorganisms.
AtıfScopus11WoS10OpenAlex10İncele - MakaleAçık Erişim2021Scopus SJRQ3Asymmetric reduction of prochiral aromatic and hetero aromatic ketones using whole-cell of Lactobacillus senmaizukei biocatalyst
Çolak, Nida Sezin; Kalay, Erbay; Şahin, Engin
Asymmetric bioreduction of aromatic and heteroaromatic ketones is an important process in the production of precursors of biologically active molecules. In this study, the bioreduction of aromatic and hetero aromatic prochiral ketones into optically active alcohols was investigated using Lactobacillus senmaizukei as a whole-cell catalyst, since whole-cells are less expensive than pure enzymes. The study indicates enantioselective bioreduction of various substituted aromatic ketones (1–16) to the corresponding (R)-and (S)-chiral secondary alcohols (1a–16a) in low to excellent enantioselectivity (6–94%) with good yields (58–95%). In addition, heteroaromatic prochiral ketones 1-(pyridin-2-yl)ethanone (17) and 1-(furan-2-yl)ethanone (18) were reduced to (R)-17a and (R)-18a in enantiopure form with excellent conversion (>99%) and yields. These findings show that L. senmaizukei is a very important biocatalyst for asymmetric reduction of both 6-membered and 5-member heteroaromatic methyl ketones. This method promising a green synthesis for the synthesis of biologically important secondary chiral alcohols in an environmentally friendly and inexpensive process.
AtıfScopus20WoS20OpenAlex19İncele - MakaleAçık Erişim2021Scopus SJRQ1Development of a Fuzzy Exponentially Weighted Moving Average Control Chart with an α-level Cut for Monitoring a Production Process
Kaplan Göztok, Kader; Uçurum, Metin; Özdemir, Akın
Statistical quality control is a useful approach that applies to statistical techniques for monitoring a production system. These charts are effective to monitor the process under certain conditions. On the other hand, the fuzzy set theory is an appropriate tool to deal with an uncertain situation. This paper is fourfold. First of all, triangular fuzzy numbers with an α-level cut technique are used for each sample. The α-level cut technique is sensitive to satisfy the process requirement. Second, a fuzzy exponentially weighted moving average (FEWMA) control chart is proposed with the α-level cut technique. The proposed FEWMA detects small shifts under uncertain situations while using a unity technique for samples. Third, the fuzzy target-focused process capability index (FCpm) index is proposed to measure the fuzzy process performance. Then, a case study is presented to monitor a pumice block plant using the FEWMA control chart with the α-level cut and measure the process performance with the FCpm index. Comparative studies are also presented. By using the proposed FEWMA control chart with the α-level cut, the accuracy and the flexibility of control specification limits are reported for the case study.
AtıfScopus9WoS8OpenAlex7İncele - MakaleAçık Erişim2021Scopus SJRQ2On global existence and bounds for the blow-up time in a semilinear heat equation involving parametric variable sources
Ayazoglu, Rabil; Akkoyunlu, Ebubekir; Aydin, Tuba Agirman
This paper is concerned with the blow-up of the solutions to a semilinear heat equation with a reaction given by parametric variable sources. Some conditions to parameters and exponents of sources are given to obtain lower–upper bounds for the time of blow-up and some global existence results.
AtıfScopus3WoS2OpenAlex2İncele