Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(115)
- Kaya, Yunus(50)
- Ayata, Ümit(48)
- Şahin, Engin(48)
- İspirli, Hümeyra(46)
- Bayraktar, Bülent(42)
- Şenay, Volkan(41)
- Can, Zehra(39)
- Özen, Soner(37)
- Bayram, Sinan(35)
- Pat, Suat(35)
- Öztürk, Mesut(35)
- Ecem Bayram, Nesrin(34)
- Esmer, Yusuf(34)
- Battal, Fetullah(33)
- Artar, Musa(32)
- Öner, Erdal(32)
- Korkmaz, Şadan(31)
- Yilmaz, Mustafa Tahsin(31)
- Ertugrul, Mehmet(30)
- Mercan, Emin(30)
- Hasar, Ugur Cem(29)
- Kutlu, Naciye(28)
- Özdemir, Akın(27)
- Kul, Murat(26)
- Cuce, Erdem(25)
- Kamiloğlu, Aybike(25)
- Bayram, Ozkan(24)
- Sefali, Abdurrahman(24)
- Sert, Durmuş(24)
- Çolak, Murat(24)
- Ayazoglu, Rabil(22)
- Gıdık, Betül(22)
- Maden, Sedat(22)
- Ustabulut, Mete Yusuf(22)
- Uçurum, Metin(22)
- Akeren, Zahide(21)
- Dirican, Ebubekir(21)
- Kara, Yakup(21)
- Abdioglu, Murat(20)
Yayınlar
- MakaleAçık Erişim2020Scopus SJRQ1Existence of multiple solutions of Schrödinger-Kirchhoff-type equations involving the p(.) -Laplacian in ℝN
Ayazoglu, Rabil; Akbulut, Sezgin; Akkoyunlu, Ebubekir
In this paper, we prove the existence of multiple solutions for the nonhomogeneous Schrödinger-Kirchhoff-type problem involving the p(.)-Laplacian (Formula presented.) where b≥0 is a constant, N ≥2, Δp(.)u:=div(|∇u|p(.)−2∇u) is the p(.)-Laplacian operator, (Formula presented.) is Lipschitz continuous, (Formula presented.) is a coercive type potential, (Formula presented.) and (Formula presented.) functions verifying suitable conditions. We propose different assumptions on the nonlinear term (Formula presented.) to yield bounded Palais-Smale sequences and then prove that the special sequences we found converge to critical points, respectively. The solutions are obtained by the Mountain Pass Theorem, Ekeland variational principle, and Krasnoselskii genus theory.
AtıfScopus1WoS1
İncele - MakaleYalnız künye2020Scopus SJRQ4Green synthesis of chiral aromatic alcohols with Lactobacillus kefiri P2 as a novel biocatalyst
Baydaş, Yasemin; Dertli, Enes; Şahin, Engin
Biocatalytic reduction is a very important field of research in synthetic organic chemistry. Herein, three different Lactic Acid Bacteria (LAB) strains were evaluated for their bioreduction potential using acetophenone as a model substrate. Among these strains, Lactobacillus kefiri P2 strain was determined as the best asymmetric reduction biocatalyst. Reaction optimization parameters such as reaction time, temperature, agitation speed and pH were systematically optimized using Lactobacillus kefiri P2 strain and model substrate acetophenone. Under these optimized reaction conditions, secondary chiral alcohols were obtained by bioreduction of various prochiral ketones with results up to 99% enantiomeric excess. In addition, the steric and electronic effects of substituents on enantioselectivity and conversion were evaluated. It has been shown that Lactobacillus kefiri P2 biocatalyst was an effective catalyst for asymmetric reduction. This method provides an environmentally friendly method for the synthesis of optically pure alcohols and an alternative approach to chemical catalysts.
AtıfScopus24WoS22OpenAlex22İncele - MakaleAçık Erişim2020Scopus SJRQ2Bioactive Characteristics of Wild Berberis vulgaris and Berberis crataegina Fruits
Eroǧlu, Arzu Yaşar; Çakir, Özlem; Saǧdiç, Mustafa; Dertli, Enes
There is an increasing trend to find novel sources of products with high antioxidant capacity and wild fruits are very good examples for these sources. In this study, fruits of Berberis vulgaris and Berberis crataegina, naturally grown in Bayburt province of Turkey, were tested for their physicochemical features, antioxidant capacities, phenolic compound profiles, and antimicrobial activities. The physicochemical analysis of the fruits revealed that the dry matter content, ash content, pH, and aw values were between 28.47% and 41.61%, 0.65% and 2.13%, 2.44 and 3.25, and 0.996 and 0.97, respectively. The total phenolic content of the fruits was determined by the Folin-Ciocalteu methodology, and for the determination of the antioxidant capacity of the fruits, DPPH, ABTS, and β-carotene bleaching methods were performed and a high level of antioxidant activity was observed. HPLC analysis was applied to identify the phenolic content of the fruits, and gallic acid and chlorogenic acid were found to be the dominant phenolic compounds in Berberis fruits. The water extracts of the Berberis fruits were tested against important foodborne pathogenic bacteria as potential antimicrobials. The extracts inhibited the growth of Bacillus cereus, Salmonella typhimurium, Yersinia enterocolitica, and Staphylococcus aureus at significant rates. This study revealed the potential antioxidant and antimicrobial characteristics of wild-type B. vulgaris and B. crataegina that can be used for different future applications.
AtıfScopus36WoS27OpenAlex26İncele - MakaleAçık Erişim2020Scopus SJRQ2Bifidogenic effect and in vitro immunomodulatory roles of melibiose-derived oligosaccharides produced by the acceptor reaction of glucansucrase E81
İspirli, Hümeyra; Kaya, Yasemin; Dertli, Enes
Glucansucrases are responsible for the production of α-glucans using sucrose as the substrate. Glucansucrases may also produce different oligosaccharides by transferring the glucose moiety from sucrose to a variety carbohydrates acting as acceptor nucleophile. In this study, melibiose-derived oligosaccharides were produced by the glucansucrase from Lactobacillus reuteri E81 expressed without the N-terminal region (GtfA-ΔN). The reaction products were characterized by TLC, LC-MS and NMR analysis and it was found that GtfA-ΔN synthesized melibiose-derived oligosaccharides (DP3 and DP4) by adding glucose units through alpha 1->3 or 1->6 glycosidic bond. The functional characteristics of these melibiose-derived oligosaccharides were determined by testing the immune-modulatory functions in HT-29 cells and testing their growth promoting effects for important probiotic and pathogenic strains. The melibiose-derived oligosaccharides triggered the production of anti-inflammatory cytokine IL-10 and pro-inflammatory cytokine TNF-α depending on their concentrations. Finally, melibiose-derived oligosaccharides showed bifidogenic effect as potential prebiotics.
AtıfScopus15WoS14OpenAlex15İncele - MakaleAçık Erişim2020Scopus SJRQ2Assessment of three mathematical prediction models for forecasting the covid-19 outbreak in Iran and Turkey
Niazkar, Majid; Türkkan, Gökçen Eryılmaz; Niazkar, Hamid Reza; Türkkan, Yusuf Alptekin
COVID-19 pandemic has become a concern of every nation, and it is crucial to apply an estimation model with a favorably-high accuracy to provide an accurate perspective of the situation. In this study, three explicit mathematical prediction models were applied to forecast the COVID-19 outbreak in Iran and Turkey. These models include a recursive-based method, Boltzmann Function-based model and Beesham's prediction model. These models were exploited to analyze the confirmed and death cases of the first 106 and 87 days of the COVID-19 outbreak in Iran and Turkey, respectively. This application indicates that the three models fail to predict the first 10 to 20 days of data, depending on the prediction model. On the other hand, the results obtained for the rest of the data demonstrate that the three prediction models achieve high values for the determination coefficient, whereas they yielded to different average absolute relative errors. Based on the comparison, the recursive-based model performs the best, while it estimated the COVID-19 outbreak in Iran better than that of in Turkey. Impacts of applying or relaxing control measurements like curfew in Turkey and reopening the low-risk businesses in Iran were investigated through the recursive-based model. Finally, the results demonstrate the merit of the recursive-based model in analyzing various scenarios, which may provide suitable information for health politicians and public health decision-makers.
AtıfScopus19WoS14OpenAlex24
İncele - MakaleAçık Erişim2020Scopus SJRQ2A comprehensive study on radiation shielding characteristics of Tin-Silver, Manganin-R, Hastelloy-B, Hastelloy-X and Dilver-P alloys
Alım, Bünyamin
In this study, it is aimed to investigate alloys that can replace lead and its derivatives in terms of radiation shielding. A new alternative shielding material must have optimum properties that should be present in a protective material. For this purpose, this study focused on the determination of the radiation-shielding characteristics of five different alloys named Tin-Silver, Manganin-R, Hastelloy-B, Hastelloy-X and Dilver-P. The photon interaction parameters (µ, µm, λ, X1/2, σT, σe, Zeff, Neff, σeff and RPE) that give significant information about the radiation shielding capacities of the materials were calculated for the alloys in the energy range from 30 to 1333 keV. The narrow-beam transmission geometry was used to determine these parameters accurately and was adjusted such that the error rate is minimized. The present samples were irradiated with photons of nineteen different photon energies emitted from seven different radionuclides (241Am, 133Ba, 109Cd, 152Eu, 22Na, 137Cs and 60Co). Photon intensities were measured by using two different detectors (Si(Li) and NaI(Tl)) for convenient photon energy regions. Then, these parameters were also calculated theoretically using Phy-X/PSD software in order to compare the experimental and theoretical results. Furthermore, the Rinc/total, Zeq, G-P fitting coefficients (a, b, c, d and XK) and exposure build-up factors (β) for the alloys were calculated using Phy-X/PSD software at photon energy range from 0.015 to 15 MeV. In order to make a significant comparison about the shielding capacities of investigated alloys, the µm values obtained for the alloys were compared with corresponding values of Pb metal, RS 253 glass and Cupero-Nickel alloy. Consequently, the descending order of MAC values in the all surveyed energy region was obtained as Tin-Silver > Manganin-R > Hastelloy-B > Hastelloy-X > Dilver-P. In the low energy region, it was found that the all present alloys have better shielding performances than RS 253 glass and Cupero-Nickel alloy. The experimental results also revealed that the Tin-Silver alloy has 25% better shielding performance than Pb metal in the energy range of 30–88 keV. Finally, it was concluded that Manganin-R alloy could be considered as the most ideal shielding material in the entire photon energies studied along with its other superior features (high density (10.22 g cm−3), high melting point (2500–2600 °C), high tensile strength (560–1150 MPa), high modulus of elasticity (320 GPa) and high specific heat (305 J K−1 kg−1) although the Tin-Silver alloy had the highest µm values among the examined alloys.
AtıfScopus57WoS49OpenAlex58İncele - MakaleYalnız künye2020Scopus SJRQ1Optimization of an adapted Kalina cycle to an actual municipal solid waste power plant by using NSGA-II method
Özahi, Emrah; Tozlu, Alperen
In this paper thermodynamic and thermoeconomic analyses and even optimization of a Kalina cycle (KC) which is adapted to an actual solid waste power plant with a 5.66 MW installed capacity are presented as an alternative solution which is utilized to produce additional power from the exhaust gas of the plant. Up to now there is almost no study related with an adapted KC to a typical municipal solid waste power plant, and also no study based on an optimization, thermodynamic and thermoeconomic analyses of such a system together. All these facts show the novelty of this study. Herein the waste heat with a temperature of 566 °C is utilized by the adapted KC. According to the analyses of the first and second law of thermodynamics on the system, it is deduced that the electricity of 954.6 kW can be produced with the exergy efficiency of 24.15%. Furthermore, this power production can be improved by using non-dominated sorting genetic algorithm method (NSGA-II) in MATLAB software program. According to the optimization study, the deviations of the net power output and the total cost rate are found to be +3.62% and −1.47 $/h, respectively for the cycle.
AtıfScopus45WoS36OpenAlex49İncele - MakaleAçık Erişim2020Scopus SJRQ3Determining the optimum model parameters for oligosaccharide production efficiency using response surface integrated particle swarm optimization method: an experimental validation study
Şensoy, Abdullah Tahir; İspirli, Hümeyra; Dertli, Enes
Glucansucrases (GTFs) catalyzes the synthesis of α-glucans from sucrose and oligosaccharides in the presence of an acceptor sugar by transferring glucosyl units to the acceptor molecule with different linkages. The acceptor reactions can be affected by several parameters and this study aimed to determine the optimal reaction parameters for the production of glucansucrase-based oligosaccharides using sucrose and maltose as the donor and acceptor sugars, respectively via a hybrid technique of Response Surface Method (RSM) and Particle Swarm Optimization (PSO). The experimental design was performed using Central Composite Design and the tested parameters were enzyme concentration, acceptor:donor ratio and the reaction period. The optimization studies showed that enzyme concentration was the most effective parameter for the final oligosaccharides yields. The optimal values of the significant parameters determined for enzyme concentration and acceptor:donor ratio were 3.45 U and 0.62, respectively. Even the response surface plots for input parameters verified the PSO results, an experimental validation study was performed for the reverification. The experimental verification results obtained were also consistent with the PSO results. These findings will help our understanding in the role of different parameters for the production of oligosaccharides in the acceptor reactions of GTFs.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2020A meta-analysis of the effect of parental involvement on students’ academic achievement
Erdem, Cahit; Kaya, Metin
This study aims to examine the effect of parental involvement on students’ academic achievement at pre-school, elementary and secondary levels by using the meta-analysis method with respect to home-based and school-based parental involvement strategies. Data consisted of 55 independent research studies in English published between 2010 and 2019, and accessed through ERIC, Academic Search Complete, Science Direct, Wiley Online Library, and PsycNet databases. Findings revealed that the effect of parental involvement on academic achievement was positive but small. Parental expectations had the biggest effect on academic achievement and parental control had a negative and small effect. The mean effect of parental involvement on students’ academic achievement does not differ significantly according to moderator variables of education level, measurement type or measurement area but differs by developmental level of the country. The results are discussed using available related meta-analysis studies in the literature.
AtıfScopus50İncele - MakaleAçık Erişim2020Scopus SJRQ1An integrated neural-fuzzy methodology for characterisation and modelling of exopolysaccharide (EPS) production levels of Leuconostoc mesenteroides DL1
Kabli, Mohammad; Yilmaz, Mustafa Tahsin; Taylan, Osman; Kaya, Yasemin; İspirli, Hümeyra; Basahel, Abdulrahman; Sagdic, Osman; Dertli, Enes
Optimisation of exopolysaccharides (EPS) production in Lactic Acid Bacteria (LAB) is an important task as EPS production can be affected by different parameters. In this respect, this study aimed to characterise the structure of an EPS from Leuconstoc mesenteroides DL1 strain and to optimise the EPS production by determination of the effects of incubation time, sucrose concentration, incubation temperature and initial levan concentration (input parameters) using integrated ANNs (Artificial neural networks) and fuzzy modelling approaches. The characterisation of the EPS monomeric composition by HPLC analysis revealed that EPS DL1 was composed of glucose and fructose. The 1H and 13C NMR spectra of EPS DL1 also confirmed the glucan and fructan production. The effects of the input parameters on glucan and fructan production levels as output parameters by DL1 were optimised using neural network and fuzzy modelling tools. The fuzzy model was developed based on the recognition of basic elements of input-output parameters, and the power of ANNs used for system identification. A structural analysis was carried out to improve the flexibility of fuzzy model, and to design the unknown mappings of the input and output parameters more robustly. The parameters then were fine-tuned by qualitative reasoning to establish the relations of input output parameters using membership functions (MFs) and their intervals determination. A hybrid training algorithm was employed for parameter identification, MFs and their interval determination to obtain the fuzzy model. The model can predict the outcome parameters; glucan and fructan with high accuracy for the predetermined input parameters.
AtıfScopus8WoS7OpenAlex9İncele - MakaleAçık Erişim2020Scopus SJRQ2Evaluation the gamma, charged particle and fast neutron shielding performances of some important AISI-coded stainless steels: Part II
Alım, Bünyamin; Şakar, Erdem; Han, İbrahim; Sayyed, M.I.
This is the second part of a two-part study on the investigation of radiation shielding performances of some important AISI-coded stainless steels (AISI-302, 304, 321 and 430). Part 1 addressed experimental evaluation by means of measured photon-material interaction parameters. In this second part, we focused on the calculation and discussion of other interaction parameters, which are a guide to choice optimum shielding materials in the nuclear processes for the present AISI-coded stainless steels. The present stainless steels have superior mechanical properties, high temperature and corrosion resistances and these properties can make them favorite materials for nuclear applications. For this reason, firstly, the incoherent scattering/total attenuation ratio (Rinc/total) and equivalent atomic number (Zeq) were calculated in the energy region of 0.015–15 MeV. Secondly, the exposure build-up factor (EBF) and energy absorption build-up factor (EABF) were determined to select steels by using Geometric Progression (G-P) fitting method, which have five parameters (a, b, c, d and XK coefficients), up to penetration depth of 40 MFP at energy 0.015–15 MeV. Thirdly, the mass stopping powers (MSPs; dE/ρdx; MeVcm2/g) and ranges (Re, Rp and Rα; μm) for electron, proton and alpha particle interactions were calculated at energy 10 keV-20 MeV. Finally, the fast neutron removal cross-sections (FNRCSs; ∑R; cm−1) were calculated. To be able to make comparison and a satisfying assessment about radiation shielding capabilities of present AISI-coded steels, all parameters were also computed for ordinary (OC), steel-scrap (SS) and steel-magnetite (SM) concretes (Fe-based steel concretes) that are most commonly used as a shielding material in many nuclear applications. The shielding capabilities of the present stainless steels against both gamma and the fast neutron and charged particle radiation were evaluated in the light of the calculated parameters. As a result of the mutual evaluation of the results obtained for the shielding concretes and the examined stainless steels, it was found that present stainless steels had excellent shielding properties compared to shielding concretes in terms of both photon radiation and particle radiation.
AtıfScopus38WoS35İncele - MakaleAçık Erişim2020Scopus SJRQ2Assessment of gamma-ray attenuation features for La+3 co-doped zinc borotellurite glasses
Rammah, Y.S.; Özpolat, Ö.F.; Alım, B.; Şakar, E.; El-Mallawany, R.; El-Agawany, F.I.
In this study, gamma ray and neutrons shielding features were evaluated for La+3 co-doped zinc borotellurite glasses with chemical formula {[(TeO2)0.70(B2O3)0.30]0.7(ZnO)0.30}1-x(La2O3)x: 0.01≤ x ≤ 0.05 mol%. Firstly, the mass and linear attenuation coefficients (MAC, LAC) for glasses were calculated via Photon Shielding and Dosimetry (PSD) software (Phy-X/PSD) in the energy range of 0.015–15 MeV. Depending on MAC and LAC, effective shielding parameters: Half value layer and mean free path (HVL, MFP), effective electron density, atomic number, and conductivity (Neff, Zeff, Ceff), exposure and energy absorption buildup factors (EBF, EABF) have been evaluated. In addition, effective fast neutron removal cross section (FNRCS) for the studied glasses have been calculated. The obtained data were compared with those of some commercial glasses and concrete. Results reveal that HVL for all samples can be arranged in the order TBZL1>TBZL2>TBZL3>TBZL4>TBZL5. The HVL, TVL and MFP values of TBZL5 glass are 2.988 cm, 9.927 cm, and 4.311 cm, respectively. TBZL5 glass has the highest Ceff values and TBZL1 glass has the lowest Ceff values. EBF values change range from 1 to 4 at 1 MFP and from 1-1010 at 40 MFP value. Therefore, it can be among the alternative materials that can be preferred in radiation application areas.
AtıfScopus48WoS47İncele - MakaleYalnız künye2020Scopus SJRQ4Screening for antioxidant capacity, pollen types and phytochemical profile by GC/MS and UHPLC from propolis
Bayram, Nesrin Ecem; Gerçek, Yusuf Can; Öz, Gül Cevahir
Propolis is a resinous mixture collected by honeybees from different parts of plants such as poplars, birches, alders, conifers, pines, palms and willows. This study aims to determine pollen types (by light microscope), chemical compound profile (by GC-MS), fatty acid composition (by GC-MS), total phenolic content (by the Folin-Ciocalteu method), total flavonoid content (by the aluminium chloride method) and antioxidant capacity (by the CUPRAC, ABTS and CERAC methods) of a propolis sample from the western part of Istanbul, Turkey. As a result of microscopic analysis of the sample, pollen types of taxa belonging to 27 plant families were diagnosed. The GC-MS analysis of propolis revealed the presence of 38 phytochemical constituents that may contribute to its quality. Of these compounds, rates of "4H-1-benzopyran-4-one, 2,3-dihydro-5,7-dihydroxy- 2-phenyl-,(S)"were highest. In addition, the concentrations of naringenin, pinocembrin and galangin were determined to be 2.45, 9.92 and 7.06 mg/ml by UHPLC analysis. The extract had significant antioxidant activity in all assays, with values of 282.8±9 mg TE /g in the CUPRAC, 425.7±18 mg TE/g in the CERAC and 186.4±8 mg TE/g in the ABTS assays. Antioxidant capacity of the propolis extract was positively associated with the total phenolic and flavonoid contents of the extract. Moreover, the major fatty acids were C20:1n9 (cis- 11-eicosenoic acid), C22:1 (erucic acid) and C24:1 (nervonic acid). The results show that the propolis used in our study has important potential as an alternative food supplement and for cosmetic and therapeutic medicine and it can be used as an active agent in these areas.
AtıfScopus20WoS18OpenAlex3İncele - MakaleAçık Erişim2020Scopus SJRQ3Synthesis of enantiopure (S)-6-chlorochroman-4-ol using whole-cell Lactobacillus paracasei biotransformation
Şahin, Engin
Chromane, which has a fused cyclic structure, is a significant molecule that can be found in the structure of many important compounds. Lactobacillus paracasei BD101 was demonstrated as whole-cell biocatalyst for the synthesis of (S)-6-chlorochroman-4-ol with immense enantioselectivity. The conditions of asymmetric reduction were optimized one factor by one factor using L paracasei BD101 to achieve enantiomerically pure product and complete conversion. Using these obtained optimization conditions, asymmetric reduction of 6-chlorochroman-4-one was performed under environmentally friendly conditions; 6-chlorochroman-4-one, having a fused cyclic structure as previously noted to be difficult to asymmetric reduction with biocatalysts, was enantiomerically reduced to (S)-6-chlorochroman-4-ol with an enantiomeric excess >99% on a high gram scale. This study is the first example in the literature for the enantiopure synthesis of (S)-6-chlorochroman-4-ol using a biocatalyst. Also notably, the optical purity of (S)-6-chlorochroman-4-ol obtained in this study through asymmetric bioreduction using whole-cell biocatalyst is the highest value in the literature. In this study, (S)-6-chlorochroman-4-ol was produced on a gram scale by an easy, inexpensive, and environmentally friendly method, which has shown the production of valuable chiral precursors for drug synthesis and other industrial applications. This study provides a convenient method for the production of (S)-6-chlorochroman-4-ol, which can meet the industrial green production demand of this chiral secondary alcohol.
AtıfScopus23WoS23OpenAlex24İncele - MakaleAçık Erişim2020Scopus SJRQ1Investigation of ammonia stripping with a hydrodynamic cavitation reactor
Taşdemir, Atila; Cengiz, İbrahim; Yildiz, Ergün; Bayhan, Yalçın Kemal
Ammonia is a commonly used compound in the domestic and industrial fields. If ammonia found in wastewater after use is not treated, even at low concentrations it may cause toxic effects in the receiving environment. In this study, a hydrodynamic cavitation reactor (HDC) was designed with the aim of removing ammonia. The effect of parameters like different cavitation numbers, airflow, temperature and initial concentration on NH3 removal was researched. The potential of hydrodynamic cavitation for removal of volatile gases, like NH3, was assessed with the aid of two film theory mathematical equations. Experimental studies were performed at fixed pH = 11. Under the conditions of 0.12 cavitation number, 25 L/min airflow, 30 °C temperature and 2500 mg/L initial concentration, in 24 h 98.4% NH3 removal efficiency was achieved. With the same experimental conditions without any air, the HDC reactor provided 89.5% NH3 removal at the end of 24 h. The HDC reactor is very effective for the removal of volatile gases from wastewater and it was concluded that even in the absence of aeration, the desired NH3 removal efficiency was provided.
AtıfScopus31WoS27OpenAlex33İncele - MakaleYalnız künye2020Scopus SJRQ2Bee bread and bee pollen of different plant sources: determination of phenolic content, antioxidant activity, fatty acid and element profiles
Mayda, Nazlı; Özkök, Aslı; Ecem Bayram, Nesrin; Gerçek, Yusuf Can; Sorkun, Kadriye
This study aims to determine the plant sources, fatty acid composition, total phenolic-flavonoid content, antioxidant capacity, and elemental profile of bee pollen (BP) and bee bread (BB) samples from the same bee hive in different locations. 31 families and 71 species were determined by pollen analysis of BP and BB samples. Pollen frequencies in BB samples were generally similar or less than in BP. Total phenolic varied from 8.26 ± 0.299 to 43.42 ± 0.779 mg GAE/g, and total flavonoid ranged from 1.81 ± 0.040 to 4.44 ± 0.125 mg QE/g. ABTS and DDPH assays indicated that the samples have good antioxidant activity. Samples showed a protein content ranging from 17.6 to 22.2% while the total fatty acid was between 60.27 and 86.49%. The elemental analysis showed that all samples were rich in essential minerals. As a result, total protein, total fatty acids, moisture content and antioxidant capacity of BB samples were found to be lower than those of BP samples from the same hive. In spite of these data, it is necessary to work with more detailed and more samples to be able to say which bee product (bee pollen or bee bread) has superior properties as functional food.
AtıfScopus154WoS143OpenAlex172İncele - MakaleAçık Erişim2020Scopus SJRQ2‘Tele-education’ in the COVID-19 pandemic process in Turkey: A mental diaspora research specific to Turkish Language Teaching students
Ustabulut, Mete Yusuf; Keskin, Savaş
This study tries to map educational processes that have to be transformed into the extraordinary history of the COVID-19 pandemic and adapt to the ‘new normal’ with a relational and metaphoric approach. In the study, the existing physical and mental conditions of the students who are "scattered/dispersed" geographically due to the mandatory "return home" in the pandemic process are conceptualized with the metaphor of the "diaspora". The study aims to draw attention to student-centered social problems by questioning the functionality of tele-education processes, which are designed to compensate for interrupted educational relationships and make them sustainable again. It is aimed to measure the effects of online consciousness that were deterritorialized by human-computer interaction and computer-mediated communication on student performances and to understand student motivations during the tele-education process. Therefore, a survey was conducted at ten universities in Turkey and reached 150 students through the snowball sampling technique. The results of the study show that the student self-perception of the tele-education process coincides with the diasporic identity and this unusual technology integration that cannot be fully compensated triggers mental diaspora feelings.
AtıfScopus5OpenAlex6TR Dizin2
İncele - MakaleAçık Erişim2020Scopus SJRQ1Effects of churning with different concentrations of ozonated water on particle size, texture, oxidation, melting and microbiological characteristics of butter
Sert, Durmuş; Mercan, Emin
The effects of churning with different concentrations of ozonated water (OW) on fat particle size, texture, oxidation, melting and microbiological characteristics of butter from raw cream were investigated. For this purpose, butter samples were produced by churning with ozonated waters at concentrations of 0 (control), 0.15 (OW-15), 0.20 (OW-20), 0.25 (OW-25) and 0.30 (OW-30) mg L−1. Churning with OW increased the lightness and redness value of samples and decreased yellowness. Firmness value of samples ranged from 126.86 to 347.46 N, with an increase with ozone concentration. Mean fat particle size (D[4.3]) value of samples decreased with higher ozone concentration in churning water. OW reduced the oxidative stability of samples. Microbial reductions by churning with ozonated water ranged from 0.07 to 1.59 log. Microbiological analysis results showed that ozone treatment improved the microbial safety of butter samples produced from raw cream.
AtıfScopus14WoS10OpenAlex15İncele - MakaleAçık Erişim2020Scopus SJRQ2Determination of yield and quality parameters of oil sunflower genotypes grown in Turkey
Gul, Volkan; Coban, Furkan
Sunflower (Helianthus annuus L) has gained importance in the world as a significant oilseed for vegetable oil. The reactions of the same sunflower genotypes to varying ecologies are different, and yield and yield characteristics may vary depending on this. In this study, we were interested in understanding the differential sensitivity of specific sunflower genotypes to different agro-ecological environments in Turkey. A 2-year (2015–2016) study was conducted on a clay-loam soil in a low and high altitude environment to (i) evaluate the genotype × location × year interaction (G×L×Y) for sunflower genotypes, (ii) predict yield components performance and identify high stable sunflower genotypes, and (iii) make genotype-specific management and high performing genotype recommendations within and across agro-ecological regions. The highest yield of seed and oil yield was obtained from the Coral (G1) genotypes, averaging 3558.5 and 1535.6 kg ha-1, respectively in Erzurum and from the 64LC108 (G4) genotypes averaging 2905.7 and 1267.4 kg ha-1, respectively in Samsun ecological conditions. As a result, the determination of the sunflower genotypes suitable for the region will provide the opportunity to obtain high-yield and high quality products because the soil, environment and climatic factors of the region in which they are grown are very useful in determining seed yield and oil content.
AtıfScopus14WoS12OpenAlex15İncele - MakaleAçık Erişim2020Scopus SJRQ1Propagation constant measurements of reflection-asymmetric and nonreciprocal microwave networks from S-parameters without using a reflective standard
Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Gokhan; Ertugrul, Mehmet
We propose a simple method for determination of forward and backward propagation constants of nonreciprocal uniform networks or lines with asymmetric reflections. The wave cascading matrix presentation is used to diagonalize and decompose the line in terms of impedance and amplitude/phase transitions. The proposed method uses scattering parameters of the line/network connection and the thru connection, thus eliminating errors arising from fabrication tolerance and thickness of the second line. Besides, compared with conventional methods which necessitate calibration techniques such as the thru-reflect-line, our method has the advantage that it determines propagation constants without resorting the measurement of any reciprocal reflective standard. Propagation constant measurements of a reciprocal network (different-length X-band waveguide straights) and a nonreciprocal network (microwave phase shifter) were first carried out and then compared with those measured by different methods to validate and monitor the accuracy of our method.
AtıfScopus13WoS12OpenAlex11İncele