Yazarlar

  • MakaleYayıncıda açık erişim2020
    Bellevalia bayburtensis (Asparagaceae): a new species from northeastern Anatolia, Turkey

    Yildirim, Hasan; Sefali, Abdurrahman

    Bellevalia bayburtensis (Asparagaceae) is described and illustrated as a new species from Bayburt Province in northeastern Anatolia, Turkey. Diagnostic morphological characters, a full description, detailed illustrations, and a distribution map are provided. It is morphologically similar to B. rixii and B. paradoxa, but clearly differs from these species by the leaf shape, the bud and flower colour.

    AtıfScopus6WoS5
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  • MakaleYayıncıda açık erişim2020
    Characterization of pediococcus acidilactici PFC69 and lactococcus lactis PFC77 bacteriocins and their antimicrobial activities in tarhana fermentation

    Kaya, Halil İbrahim; Şimşek, Ömer

    Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.

    AtıfScopus29WoS25
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2020
    An analysis of the role of the social acceptance of University Students' bicycle use in sustainable urban development when epidemics spread

    Saatchian, Vahid; Azimkhani, Amin; Honari, Habib; Türkmen, Mutlu

    The purpose of this study was to investigate the role of the acceptance of university students' bicycle use in sustainable urban development in Iran when epidemics spread. The research method was descriptivecorrelational, and the investigation was carried out as a field study. The statistical population of the study consisted of university students, 254 of whom were selected by a simple random sampling method to participate in the research. The research instrument was a questionnaire based on the Sustainable Development with a reliability coefficient of 0.83; the social acceptance component was based on the theory of planned behaviour with a reliability coefficient of 0.8. As the results of the investigation have demonstrated, the bicycle plays a significant role in the development of the socialization process of people, and there is a positive and significant relationship between social acceptance and sustainable development (p<0.05). Furthermore, 20% of sustainable development change was achieved through the dimensions of social acceptance (planned behaviour theory). Finally, it can be argued that perceived behaviour in social acceptance is most likely to play a significant role in the emergence of sustainable development by external factors such as encouragements and persuasion of the family, important people, friends, acquaintances, and even by the existing norms in society. Subsequently, as people change their mindset when epidemics spread, they can turn all the behaviours they manifest in their leisure time into a culture development movement.

  • MakaleYalnız künye2020
    Bio-catalytic asymmetric synthesis of β-adrenergic receptor blocker precursor: (R)-2-bromo-1-(naphthalen-2-yl)ethanol

    Taşdemir, Volkan; Kalay, Erbay; Dertli, Enes; Şahin, Engin

    Aromatic α-halohydrins, particularly 2-haloethanols as significant precursor of drugs, can easily be converted to chiral β-adrenergic receptor blockers. Eight strains of Lactobacillus curvatus were tested as biocatalysts for asymmetric reduction of 2-bromo-1-(naphthalen-2-yl)ethanone 1 to 2-bromo-1- (naphthalen-2-yl) ethanol 2. The parameters of the bioreduction were optimized using L. curvatus N4, the best biocatalyst found. As a result, (R)-2-bromo-1-(naphthalen-2-yl)ethanol 2, which can be β-adrenergic receptor blocker precursor, was produced for the first time in high yield and enantiomerically pure form using biocatalysts. Moreover, the gram scale synthesis was performed and 7.54 g of (R)-2 was synthesized as enantiopure form (enantiomeric excess >99%) in 48 h. The important advantages of this process are that it produces of (R)-2 for the first time in enantiopure form, in excellent yield and under environmentally friendly and moderate reaction conditions. This system is of the potential to be applied at a commercial scale.

    AtıfScopus2WoS2
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  • MakaleYalnız künye2020
    Current–voltage analyses of Graphene-based structure onto Al2O3/p-Si using various methods

    Efil, Esra; Kaymak, Nuriye; Seven, Elanur; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge; Tataroglu, Adem

    The present study's main purpose is to determine the current-voltage (I–V) performance of Graphene (Gr) based hetero nanostructure produced on Al2O3/p-Si. Graphene synthesis was carried out using the chemical vapor deposition (CVD) technique on Copper (Cu) foils used as a metal catalyst and transferred onto Al2O3/p-Si using the conventional transfer method. The I–V characteristics of this structure were measured in the dark environment, and the electrical properties of the Gr/Si structure were characterized at room temperature. The rectifying ratio (RR) of the structure was found to be about 103 at ± 3 V. The electrical properties of ideality factor (n), series resistance (Rs), and barrier height (Φb) were examined by using the theory of Thermionic Emission (TE), Norde's method, and Cheung's method. The values of Φb, which were calculated using Norde's method, Cheung's method, and the theory of thermionic emission (TE), were found to be 0.69 eV, 0.71 eV, and 0.68 eV, respectively. The ideality factor was found to be approximately 3.89 according to the theory of TE. The values of series resistance were also determined using the Norde's method and Cheung's two different parameters (dV/dln(I) and H(I)) found to be 9.60 kΩ, 9.12 kΩ, and 5.94 kΩ, respectively.

    AtıfScopus25WoS25
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  • MakaleYalnız künye2020
    Phy-X/ZeXTRa: a software for robust calculation of effective atomic numbers for photon, electron, proton, alpha particle, and carbon ion interactions

    Özpolat, Ö.F.; Alım, B.; Şakar, E.; Büyükyıldız, M.; Kurudirek, M.

    The purpose of the present work is robust calculation of effective atomic numbers (Zeffs) for photon, electron, proton, alpha particle and carbon ion interactions through the newly developed software, Phy-X/ZeXTRa (Zeff of materials for X-Type Radiation attenuation). A pool of total mass attenuation and energy absorption coefficients (for photons) and total mass stopping powers (for charged particles) for elements was constructed first. Then, a matrix of interaction cross sections for elements Z = 1–92 was constructed. Finally, effective atomic numbers were calculated for any material by interpolating adjacent cross sections through a linear logarithmic interpolation formula. The results for Zeff for photon interaction were compared with those calculated through Mayneord’s formula, which suggests a single-valued Zeff for any material for low-energy photons for which photoelectric absorption is the dominant interaction process. The single-valued Zeff was found to agree well with that obtained by other methods, in the low-energy region. In addition, Zeff values of various materials of biological interest were compared with those obtained experimentally at 59.54 keV. In general, the agreement between values calculated with Phy-X/ZeXTRa and Auto-Zeff and those measured were satisfactory. A comparison of Zeff values for photon energy absorption calculated with Phy-X/ZeXTRa and literature values for a nucleotide base, adenine, was made, and the relative difference (RD) in Zeff between Phy-X/ZeXTRa and literature values was found to be 2% &#x003C; RD &#x003C; 11%, at low photon energies (1–100 keV), while it was less than 1% at energies higher than 100 keV. Highest Zeff values were observed at low photon energies, where photoelectric absorption dominates photon interaction. For electrons, corresponding RD(%) values in Zeff were found to be in the range 0.4 ≤ RD(%) ≤ 1.7, while for heavy charged particle interactions it was 2.4 ≤ RD(%) ≤ 4.2 for total proton interaction and 0 ≤ RD(%) ≤ 8 for total alpha particle interaction. In view of the importance of Zeff for identifying and differentiating tissues in diagnostic imaging as well as for estimating accurate dose in radiotherapy and particle-beam therapy, Phy-X/ZeXTRa could be used for fast and accurate calculation of Zeff in a wide energy range for both photon and charged particle (electrons, protons, alpha particles and C ions) interactions.

    AtıfScopus88WoS77
    ScopusWeb of SciencePubMedİncele
  • MakaleYayıncıda açık erişim2020
    Investigating the adipokine and cardiac troponin response ın experimental thyroid dysfunction; [Odgovor adipokina i srčanog troponina na eksperimentalno izazvanu disfunkciju štitne žlijezde brojlera]

    Bayraktar, Bülent; Tekce, Emre; Takma, Çiğdem; Bayraktar, Sevil; Kilinç, Ayten A.; Ülker, Ufuk; Kurtdede, Efe

    This study was conducted to investigate adipokine [Apelin and brain-derived neurotrophic factor (BDNF)] and cardiac troponin (cTnI) response that emerged after adding an essential oil mixture (EOM) (Eucalytus glabutus labii, Thymus vulgaris, Cymbopogon nardus, and Syzygium aromaticum) at different rates to the drinking water of broilers in which thyroid dysfunction (hypo-and hyperthyroidism) had been experimentally induced. In the present study, 150 1-day-old Ross-308 male broiler chicks were used. They were divided into five groups, each with 30 animals. The groups were designed to include five subgroups: control (C), hypothyroid, hypothyroid + 250 ppm EOM, hyperthyroid, and hyperthyroid + 250 ppm EOM, with six animals in each group. At the end of the experiment, Apelin, p-BDNF, cTnI, T3, T4, and thyroid-stimulating hormone (TSH) levels were investigated in blood serum samples obtained by cervical dislocation from four randomly selected animals from each subgroup, making 100 animals in total. It was found that EOM administration resulted in a dose-dependent increase in p-BDNF and apelin levels, and a decrease in T4 levels in the experimentally induced hypo-and hyper-thyroidism groups, but did not affect T3 and cTnI levels. Conversely, an increase in TSH level was observed in the hypothyroidism groups, whereas a decrease was observed in groups with hyperthyroidism. This study is the first to examine adipokine (Apelin and BDNF) and cTnI response to EOM administration in thyroid dysfunction.

    AtıfScopus3WoS3
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  • MakaleYalnız künye2020
    Simulation and optimization of gamma-ray linear attenuation coefficients of barite concrete shields

    Şensoy, A.T.; Gökçe, H.S.

    The remarkable increment in radioactivity risks of today's industrial world is required to the efficient design of shielding structures. In the present study, the optimal design parameters of barite concrete shields for providing the highest gamma radiation shielding capability were researched by using a hybrid technique of the Box-Behnken Design based response surface method and Particle Swarm Optimization. Barite aggregate fraction, water-to-cement ratio and cement content of the shields were limited as 0:100 (by weight), 0.30:0.70 (by weight) and 200:600 (kg/m3) in the optimization problem, respectively. The regression equation derived from the regression learning process presented an excellent correlation to define the XCOM linear attenuation coefficients. A nonlinear response surface fitted to the regression equation was used as the validation of the PSO results obtained from MATLAB. The results of this study have shown that the proposed method provides satisfactory predictions for the barite concrete radiation-shielding capability depending on the design parameters. In addition, it was found that the linear attenuation coefficient could be increased by 102% by the design of the best shield according to the poorest mixture.

    AtıfScopus77WoS66
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2020
    A mathematical model and tabu search algorithm for multi-manned assembly line balancing problems with assignment restrictions

    Yilmaz, Hamid; Yilmaz, Mustafa

    A multi-manned assembly line is a set of workstations where task operations can be performed on multiple sides of the line. Such assembly lines are important for large products, such as buses, cars and trucks. In this study, a mathematical model for multi-manned assembly lines with assignment restrictions is proposed. The purpose of the mathematical model is to minimize the total number of workers and open multi-manned workstations along the line for a given cycle time simultaneously under various assignment restrictions. The model provides a more realistic situation for multi-manned assembly line problems. The tabu search algorithm (TSA) is also used to solve the problem. The performances of both methods on well-known data-set problems are analysed. Based on the computational experiments, the performance of the proposed TSA is compared with the mathematical model solutions on various problem instances. The experimental results verify the effectiveness and efficiency of the proposed TSA.

    AtıfScopus33WoS28
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  • MakaleYalnız künye2020
    Examination of analytical and finite element solutions regarding contact of a functionally graded layer

    Yaylacı, Murat; Adıyaman, Gökhan; Öner, Erdal; Birinci, Ahmet

    In this study, the continuous and discontinuous contact problems of functionally graded (FG) layer resting on a rigid foundation were considered. The top of the FG layer was loaded by a distributed load. It was assumed that the shear modulus and the density of the layer varied according to exponential functions along the depth whereas the the Poisson ratio remained constant. The problem first was solved analytically and the results were verified with the ones obtained from finite element (FE) solution. In analytical solution, the stress and displacement components for FG layer were obtained by the help of Fourier integral transform. Critical load expression and integral equation for continuous and discontinuous contact, respectively, using corresponding boundary conditions in each case. The finite element solution of the problem was carried out using ANSYS software program. In continuous contact case, initial separation distance and contact stresses along the contact surface between the FG layer and the rigid foundation were examined. Separation distances and contact stresses were obtained in case of discontinuous contact. The effect of material properties and loading were investigated using both analytical and FE solutions. It was shown that obtained results were compatible with each other.

    AtıfScopus71WoS72
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  • MakaleYalnız künye2020
    Experimental investigation of effects on performance, emissions and combustion parameters of biodiesel–diesel–butanol blends in a direct-injection CI engine

    Örs, İlker; Sarıkoç, Selçuk; Atabani, A.E.; Ünalan, Sebahattin

    This paper aims to asses and conduct a comparative analysis of fuel properties, performance, emissions and combustion characteristics of biodiesel produced from waste cooking oil (B100) as a cheap biodiesel feedstock, along with a binary blend of biodiesel–diesel (B20) and ternary blends of biodiesel–diesel–butanol as substitutions to diesel fuel. Although biodiesel and n-butanol have some negative impacts on engine performance parameters, they generally positively affect exhaust emission parameters compared to euro diesel. B100 caused an average reduction in brake power and exhaust gas temperature of 15.16% and 1.4%, respectively, although it increased brake specific fuel consumption on average by 14.09%, at full throttle under different engine load conditions. B100 decreased CO and HC emissions and smoke opacity by 65.4%, 61.07% and 54.94%, respectively. However, CO2 and NO emissions increased by 22.3% and 23.91%, respectively. Addition of n-butanol decreased some of the fuel thermo-physical properties such as density, viscosity and flash point. The average decreases in brake power when n-butanol was added were 6.17%, 7.49% and 11%, respectively, coupled with increases in specific fuel consumption of 6.25%, 8.96% and 14.29%, respectively. The addition of n-butanol decreased exhaust gas temperatures, CO, HC, NO and smoke emissions.

    AtıfScopus41WoS33
    ScopusWeb of Scienceİncele
  • MakaleYalnız künye2020
    Antiamnesic effects of tofisopam against scopolamine-induced cognitive impairments in rats

    Üçel, Umut İrfan; Can, Özgür Devrim; Demir Özkay, Ümide; Ulupinar, Emel

    In this study, we investigated the potential therapeutic effects of tofisopam, a 2,3-benzodiazepine derivative anxiolytic, on cognitive deficits in rats with scopolamine-induced amnesia. Cognitive performance of the rats was investigated by using the Morris water maze and passive avoidance tests. Changes in motor activity were assessed by using the activity cage and Rota-rod tests and then morphological changes in the hippocampus were assessed via immunohistochemical stainings. The results indicated that scopolamine impaired learning and memory parameters in rats. Worsened cognitive performance, neuronal loss, and decreased hippocampal synaptophysin, Ki-67, and glial fibrillary acidic protein density were observed. Tofisopam administration at a dose of 50 mg/kg for seven days improved the impaired cognitive performance, enhanced the attenuated synaptic transmission in the hippocampus, increased proliferation in subgranular zones, and improved the decrease in astrocytes in amnesic rats. These findings point out the anti-amnesic effects of tofisopam with concomitant improvements in the hippocampal synaptogenesis, neurogenesis, and glial plasticity, for the first time. Presented beneficial effects of tofisopam on cognitive dysfunctions may have a notable clinical value considering the fact that one of the most important side effects of 1,4-benzodiazepines, which are classical anxiolytic drugs, is amnesia. However, these preclinical results need to be confirmed with further clinical studies, first.

    AtıfScopus23WoS20
    ScopusWeb of SciencePubMedİncele
  • MakaleYayıncıda açık erişim2020
    Bioproduction, structure elucidation and in vitro antiproliferative effect of eumelanin pigment from Streptomyces parvus BSB49

    Bayram, Sinan; Dengiz, Cagatay; Gerçek, Yusuf Can; Cetin, Idil; Topcul, Mehmet R.

    In this study, the structure of the purified extracellular eumelanin pigment isolated from Streptomyces spp. was elucidated by detailed analysis via two different spectroscopic techniques (FT-IR and NMR). In vitro antiproliferative effects of eumelanin were evaluated on HeLa cell line. These experiments were carried out with the evaluation of the parameters including cell viability, cell index, and mitotic index. With the cell viability and cell index, IC50 concentration of eumelanin was determined as 10 μM. This result showed that the IC50 concentration of eumelanin decreased the values of cell viability, cell index and mitotic index. These changes are statistically significant (p ' 0.01). The ability of the dissolved eumelanin (250 μg mL−1) to scavenge free radicals was determined via DPPH and ABTS and was shown to be about 87.73% and 75.2%, respectively, compared with standard antioxidants. It was observed that dry weights of eumelanin yield among the selected strains ranged from 160 to 240 mg L−1. The strain with the highest production potential was selected for 16S rDNA sequence analysis and, accordingly, the selected strain BSB49 was identified as Streptomyces parvus and the sequence analysis results were deposited in NCBI under accession number MK894155.

    AtıfScopus47WoS40
    ScopusWeb of SciencePubMedİncele
  • MakaleYayıncıda açık erişim2020
    Optimization of cryoprotectant formulation to enhance the viability of Lactobacillus brevis ED25: Determination of storage stability and acidification kinetics in sourdough

    Gul, Latife Betul; Gul, Osman; Yilmaz, Mustafa Tahsin; Dertli, Enes; Con, Ahmet Hilmi

    In this study, various kinds of cryoprotectant (skim milk, lactose, and sucrose) formulations were tested to enhance the survival of Lactobacillus brevis ED25 after freezing and freeze-drying. A Box–Behnken experimental design was used to optimize cryoprotective medium and the highest cell survival was observed with the 17.28% skim milk, 2.12% lactose, and 10% sucrose cryoprotectant as the optimum condition. The structural and physicochemical characteristics of freeze-dried powder were acceptable for application with regards to particle surface morphology, moisture and water activity (Aw), glass transition temperature (Tg), Fourier transform infrared spectra, X-ray structure, and also storage stability under the refrigeration and room temperature conditions. Accelerated storage test based on Arrhenius equation could be used to predict the freeze-dried bacterial shelf life but only with a certain degree of predictability for long-term storage. The acidification kinetics of fresh and stored culture in sourdough fermentation was also described on the basis of the Gompertz equation. Practical applications: Freezing and storage are crucial factors for the viability and acidification power of starter culture. Therefore, various types and concentrations of cryoprotectants have been used to preserve the microorganisms. L. brevis ED25 has been a good potential for the manufacture of industrial sourdoughs and this research has aimed to investigate long-term protective effects of optimum cryoprotectant formulations on the viability of bacteria and also determine the acidification power in sourdough. The results showed the potential value of freeze-dried L. brevis ED25 culture for commercialization.

    AtıfScopus26WoS18
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  • MakaleYayıncıda açık erişim2020
    Gge biplot analysis in wild (Pisum sativum l. subsp. elatius and subsp. sativum) and cultivated pea (pisum sativum l.) genotypes in northern and southern turkey

    Girgel, U.; Cokkizgin, A.

    This research was carried out in the multiple-environment trials (MET) which one is in Bayburt (40°24'05.7"N 40°08'31.3"E) where the Black Sea geographical region located in the north of Turkey and in the Kahramanmaras (37°35'24.8"N 36°48'49.4"E) where the Mediterranean geographical region located in the south of Turkey in 2016 and 2017 years. In this investigation, 6 registered pea cultivars (Bolero, Jof, Karina, Nihal, Reyna and Utrillo) and 2 wild pea genotypes (Pisum sativum L. subsp. elatius and P. sativum L. subsp. sativum) were used. The variance analysis showed a significant difference among Location (L), genotypes (G), genotypes×locations interaction (GL), genotypes×year interaction (GY), year×location interaction (YL) (all significant at P<0.01 level) and genotype×location×year interaction (GLY) (significant at P<0.05 level) interaction in terms of seed yield. Main effect genotypes (G) is explained 24.42% of total variation. This is followed by 18.78% (L), 17.87% (YL) 7.04% (GL), 4.91% (GY), 2.71% (GLY) and 1.12% (Y), respectively. Graphs were drawn according to the results of GGE biplot analysis and yield data of genotypes were evaluated according to these graphs. In accordance with GGE biplot analysis the seed yield first principal component explained 82.81% of the total variation and second principal component explained 17.19% of the total variation.

    AtıfScopus2WoS2
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  • MakaleYalnız künye2020
    D-optimal experimental design for production models in nonstandard experiments

    Özdemir, Akın

    Robust design is an effective Quality by Design method to reduce product variation by selecting levels of design factors. For a number of situations, a nonstandard design region with linearly limited resources is needed to conduct an experiment. In the literature, little attention has been given to the development of robust design models for the nonstandard design region with a combination of linearly limited resources and a limited number of design points. In this paper, a selection scheme of D-optimal experimental design points is proposed to generate design points using the modified exchange algorithm for the nonstandard design region while specifying linearly limited resources and the limited number of design points. The modified exchange algorithm is able to generate global design points with less time complexity than the improved Fedorov algorithm. In addition, robust design models linking a D-optimal experimental design with quality considerations are proposed in order to obtain optimum settings of design factors for the product. Comparative studies are also presented. Finally, a real-life experimental study shows that the proposed models with the desirability function and the sequential quadratic programming technique achieve greater variance reduction than the traditional counterparts.

    AtıfScopus16WoS15
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  • MakaleYayıncıda açık erişim2020
    The Relationship between Self-Regulation and Proportional Reasoning: The Mediating Role of Reflective Thinking towards Problem Solving

    Öztürk, Mesut

    The present study examines the mediating impact of reflective thinking on problem-solving among seventh-grade students, focusing on the link between self-regulation and proportional reasoning. A relational research model was used to provide the quantitative research design. The prediction model proposed in this study was tested with 279 seventh-grade middle-school students. Data were collected using the 'Reflective thinking towards problem-solving scale', the 'Perceived self-regulation scale' and the 'Proportional reasoning skill test'. Correlation and mediation analyses were performed on the collected data. The results demonstrate that reflective thinking toward problem-solving is significantly related to self-regulation and proportional reasoning. The mediation analysis shows that seventh-grade students' reflective-thinking skills towards problem-solving partially mediate between their self-regulation levels and proportional-reasoning skills.

    AtıfScopus2WoS1
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  • MakaleYayıncıda açık erişim2020
    Structural and technological characterization of ropy exopolysaccharides produced by Lactobacillus plantarum strains isolated from Tarhana

    Zehir Şentürk, Duygu; Dertli, Enes; Erten, Hüseyin; Şimşek, Ömer

    Exopolysaccharide producing starter cultures enable manufacturing “clean labeled” foods with improved textural and nutritional properties. The structural and technological analyses were performed on the ropy exopolysaccharides of six Lactobacillus plantarum. The incubation temperature, time and pH affected the exopolysaccharide production and high exopolysaccharide was produced in the presence of sucrose and maltose. The viscosity of exopolysaccharide was high at acidic conditions except PFC311E that showed viscous at neutral pH. Lactobacillus plantarum strains produced between 120 and 400 mg/L exopolysaccharide in which the highest was observed at L. plantarum PFC311. Exoploysaccharides were degraded over 300 °C except PFC311E that degraded at 295.7 °C. The NMR analyses revealed that the exopolysaccharides were synthesized by α1-6, α1-3 and α1-4 bonds with glucose, galactose and fructose moieties. In conclusion, L. plantarum PFC311 produced ropy exopolysaccharide with different structural, rheological and thermal properties and reveals potential to be used in food industry.

    AtıfScopus42WoS37
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  • MakaleYayıncıda açık erişim2020
    Preservice teachers' metaphors about the concept of space perception

    Kuzey, Mehmet

    The aim of this study is to reveal the metaphors produced by the students of the Faculty of education regarding the concept of space perception. In accordance with this aim, the phenomenon design from qualitative research designs was used. The working group consists of 261 teachers who study in the Departments of Bayburt University Faculty of Education, Turkish, Social Sciences and primary education in the 2018-2019 academic year. "Perception of spatial" in order to determine the metaphors produced by the teacher candidates for the concept of "perception of spatial"... like/is similar to because... "the semi-structured form containing the statement was distributed and they were asked to convey their thoughts. The data obtained at the end of the study were analyzed in accordance with the content analysis. Participants produced a total of 109 valid metaphors for the concept of space perception, and these metaphors were grouped under 10 different categories. As a result of the study, it was determined that half of the teachers associated the concept of space perception directly with the words that contain the meaning of the concept of space.

    AtıfScopus2
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  • MakaleYalnız künye2020
    A research on optimum designs of steel frames including soil effects or semi rigid supports using Jaya algorithm

    Artar, Musa; Daloğlu, Ayşe T.

    The effect of soil foundation plays active role in optimum design of steel space frames when included. However, its influence on design can be calculated after a long iterative procedure. So it requires longer computer time and more computational effort if it is done properly. The main purpose of this study is to investigate how these effects can be calculated in more practical way in a shorter time. The effects of semi-rigid column bases are taken into account in optimum design of steel space frames. This study is carried out by using JAYA algorithm which is a novel and practical method based on a single revision equation. The displacement, stress and geometric size constraints are considered in the optimum design. A computer program is coded in MATLAB to achieve corporation with SAP2000-OAPI (Open Application Programming Interface) for optimum solutions. Four different steel space frames including soil structure interaction taken from literature are investigated according to different semi-rigidly supported models depending on different rotational stiffness values. And the results obtained from analyses are compared with the results available in reference studies. The results of the study show that semi-rigidly supported systems in the range of appropriate rotational stiffness values offer practical solutions in a very short time. And close agreement is obtained with the studies on optimum design of steel space frames including soil effect underneath.

    AtıfScopus8WoS9
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