Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleAçık Erişim2021Scopus SJRQ2
    Production of bread from doughs composed of high-pressure homogenisation treated flour slurries: effects on physicochemical, crumb grain and textural characteristics

    Sert, Durmuş; Mercan, Emin; Tongur, Aymelek; Kara, Ümmügülsüm

    This study aimed to investigate the physicochemical and textural characteristics of bread produced from doughs composed of high-pressure homogenization (HPH) treated flour slurries. For this purpose, bread samples were produced from doughs composed of HPH treated flour slurries at 0 (control), 20, 30, 50, and 70 MPa. HPH treatment resulted in decreased particle size with more uniformity in flour slurries. A monomodal particle size distribution was determined in slurries. HPH obtained higher firmness, consistency, and cohesivity in slurries. In bread samples, HPH increased yellowness and lightness values. The bread samples prepared from HPH treatment had 1.09–1.25 times higher specific volumes than the control sample. HPH treatment provided decreased hardness and increased cohesiveness and springiness values. Image analysis results showed HPH treatment decreased total cell count, whereas increased mean cell area of bread samples. The findings revealed that HPH treatment results in higher quality bread compared to control.

    • SDG 2 · Açlığa Son
    AtıfScopus5WoS5OpenAlex6
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  • MakaleAçık Erişim2021Scopus SJRQ3
    Comparing of the Magnetic Force Parameters of Superconducting Maglev System Using Horizontal and Vertical PMG Geometry in Multi-Surface HTS-PMG Arrangement

    Ozturk, Kemal; Savaskan, Burcu; Abdioglu, Murat; Cansiz, Ahmet; Dilek, Durukan Burak; Karaahmet, Zekeriya

    In this study, a detailed static and dynamic experimental studies were carried out in different cooling heights (CH) by using two different multi-surface HTS-PMG arrangements with horizontal (MS-H) and vertical (MS-V) geometries to determine the optimum magnetic force, static stiffness, dynamic response, and dynamic stiffness parameters of superconducting Maglev system. The maximum levitation force values (in CH = 25 mm) were obtained as 202 N and 84 N, respectively, with horizontal and vertical geometry HTS-PMG arrangements, while the maximum guidance force values (in CH = 5 mm) were obtained as −58 N and −22 N, respectively. Also, the vertical static (in CH = 25 mm) and dynamic stiffness (in CH = 5 mm) values were determined as 33.8 N/mm and 37.8 N/mm, respectively, for MS-H and 12.3 N/mm and 25.1 N/mm, respectively, for MS-V arrangements. The bigger levitation force, guidance force, and both static and dynamic magnetic stiffness values of MS-H arrangement with horizontal geometry than that of MS-V arrangement with vertical geometry indicate that the horizontal HTS-PMG geometry is more suitable for practical Maglev applications in terms of loading capacity and movement stability.

    AtıfScopus5WoS4OpenAlex4
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  • MakaleYalnız künye2020Scopus SJRQ2
    Effects of processing methods and extraction solvents on the chemical content and bioactive properties of propolis

    Ecem Bayram, Nesrin; Gerçek, Yusuf Can; Bayram, Sinan; Toğar, Başak

    The aim of this study was to evaluate the bioactive properties of propolis extract prepared using different solvents and different extraction methods. The extracts were analyzed by gas chromatography–mass spectrometry (GC–MS) and the differences between their antibacterial activities were evaluated by disc diffusion method. At the same time, bioactive properties of different concentrations of propolis extracts were investigated on human umbilical vein endothelial cells (HUVEC). The proliferative effects and cytotoxic effects of the extracts were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) analyzes, respectively. Total antioxidant capacity (TAC) and total oxidative status (TOS) parameters were used in assessing biochemical effects in the HUVEC cell line. The DNA damage was also analyzed by 8-oxo-2-deoxyguanosine (8-OHdG) level as indicators of genotoxicity. As a result of the MTT analysis conducted within the scope of the present study, the extracts tested were sorted as 95% ethanol extract of propolis (PEE95) > ultrasonic ethanol extract of propolis (PUEE) > 50% ethanol extract of propolis (PEE50) > ultrasonic water extract of propolis (PUWE) in terms of the effectiveness of their cell viabilities. It was observed that high concentrations of PEE95 induced LDH release. In addition to this, our findings have shown that PEE50, PUEE and PUWE increased oxidative stress at high concentrations. According to 8-OH-dG analysis, all tested extracts were found to be non-genotoxic. The results obtained from antibacterial activity and minimum inhibition concentration tests showed that PUEE and PEE95 had stronger antibacterial effects than PEE50 and PUWE. All these results indicated that propolis has beneficial effects for human health and therefore it is a valuable product which can be used as a food supplement.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus23WoS22OpenAlex25
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  • MakaleYalnız künye2020Scopus SJRQ2
    Electrical properties of Graphene/Silicon structure with Al2O3 interlayer

    Kaymak, Nuriye; Bayram, Ozkan; Tataroğlu, Adem; Bilge Ocak, Sema; Oz Orhan, Elif

    The electrical properties of the fabricated Al/Gr/Al2O3/p-Si structure have been analyzed using frequency-dependent capacitance/conductance–voltage (C/G–V) measurements. Graphene (Gr) nanosheets were grown on to copper (Cu) catalyst substrate, which has 99.99% purity, by Chemical Vapor Deposition (CVD) technique, and then the Graphene was transferred on Al2O3/p-Si by the standard transfer process. The Graphene structures have been characterized by Raman Spectroscopy and Transmission Electron Microscopy (TEM) analyses, and the results of both analyses confirmed the monolayer/bilayer Graphene nanostructure. The forward and reverse bias G–V and C–V measurements of this structure have been performed in 10 kHz–400 kHz and at 300 K. The frequency dispersion in C and G can be evaluated for interface state density (Dit) and series resistance (Rs) values. The values of Dit and Rs are dependent on frequency and increase with decreasing frequency. The Rs- V graph shows a peak form at all frequencies in the depletion region and vanishes with increasing frequency. The obtained results suggest that the prepared structure can be used in electronic device applications.

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  • MakaleYalnız künye2020Scopus SJRQ2
    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% < RD < 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.

    AtıfScopus88WoS77OpenAlex94
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  • MakaleAçık Erişim2020Scopus SJRQ2
    Graphene/polyaniline nanocomposite as platinum-free counter electrode material for dye-sensitized solar cell: its fabrication and photovoltaic performance

    Bayram, Ozkan; Igman, Erdal; Guney, Harun; Demir, Zeynep; Yurtcan, Mustafa Tolga; Cirak, Cagri; Hasar, Ugur Cem; Simsek, Onder

    In this study, it was aimed to produce graphene/polyaniline nanocomposite thin films as counter electrode materials by PECVD system and to determine the photovoltaic performances of these counter electrodes in dye-sensitized solar cells (DSSCs). Graphene/polyaniline counter electrode (GPCE) material was produced in two different steps. Firstly, a single-layer and multilayer graphene thin films were produced on the fluorine-doped tinoxide (FTO) substrates. Then, polyaniline (PANI) thin films were grown on each graphene thin films using plasma polymerization technique, and eventually the production of the graphene/PANI nanocomposite was completed. The fabricated graphene/PANI nanocomposites were used in place of platinum (Pt)-counter electrode which is widely used in DSSCs and the photovoltaic performance of these counter electrodes was investigated. The DSSCs consisted of titanium dioxide (TiO2) nanotube photoanode, N719 dye, iodolyte liquid electrolyte, and graphene/PANI nanocomposite counter electrode. I–V measurements were carried out in order to calculated photoconversion efficiency (PCE) and it was found that the these efficiency of GPCEs changed between 0.56 and 1.36% according to the number of graphene layers. The photovoltaic performance of DSSC, consisting of TiO2 nanotube photoanode and Pt-counter electrode was 1.1%.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    AtıfScopus33WoS25OpenAlex29
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  • MakaleAçık Erişim2020Scopus SJRQ3
    Technological properties of autochthonous Lactobacillus plantarum strains isolated from sucuk (Turkish dry-fermented sausage)

    Kamiloğlu, Aybike; Kaban, Güzin; Kaya, Mükerrem

    Purpose: Five Lactobacillus strains isolated from sucuk (Turkish dry-fermented sausage) were studied for their genetic and technological properties. Methods: For genotypic identification, strains 16S rRNA gene sequences were used. To determine the antimicrobial activity of strains, seven foodborne pathogens were tested. Strains technological properties were characterized. Results: These strains were identified as Lactobacillus plantarum by 16S rRNA gene sequence analysis and the phylogenetic tree obtained by neighbor-joining method allowed grouping of these strains into three subgroups. L. plantarum strains showed antagonistic activities against Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, and Micrococcus luteus strains. PCR assay, using specific primers, showed the presence of bacteriocin (plantaricin) encoding genes in all L. plantarum strains tested. Antimicrobial metabolite production of these strains started at log phase and reached the maximum level at the end of the stationary phase. Regarding their technological properties, better growth was observed at 25 °C compared with 15 °C and 45 °C. The isolates which grown well within the pH scale pH 4.5–6.5 range additionally showed a decent growth at 6.5% salt concentration. It has been found that strains do not exhibit lipolytic and proteolytic activities nor have lysine, ornithine, and arginine decarboxylase activity. On the other hand, one strain showed weak nitrate reductase activity, and four strains produced acetoin from glucose. In addition, all strains were DL-lactic acid producers. Consequently, L. plantarum strains isolated exhibited some biochemical properties required for a starter culture in sucuk and similar products. Conclusions: All identified strains may be a protective culture in the production of fermented meat products. In particular, L. plantarum S51 was distinguished from other isolates due to the inability to form acetoin from glucose. Further work will be needed to characterize L. plantarum strains as starter culture.

    • SDG 2 · Açlığa Son
    AtıfScopus11WoS7OpenAlex9
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  • MakaleAçık Erişim2020Scopus SJRQ2
    A 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.

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  • MakaleYalnız künye2020Scopus SJRQ2
    Bee 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.

    • SDG 2 · Açlığa Son
    AtıfScopus154WoS143OpenAlex172
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  • MakaleAçık Erişim2019Scopus SJRQ3
    Infinitely many solutions for the stationary fractional p -Kirchhoff problems in RN

    Akkoyunlu, Ebubekir; Ayazoglu, Rabil

    In the present paper, we investigate the existence of multiple solutions for the nonhomogeneous fractional p-Kirchhoff equation M(∬R2N|u(x)-u(y)|p|x-y|N+psdxdy+∫RNV(x)|u|pdx)×((-Δ)psu+V(x)|u|p-2u)=f(x,u)inRN,where (-Δ)ps is the fractional p-Laplacian operator, 0 < s< 1 < p< ∞ with sp< N, M:R0+→R0+ is a nonnegative, continuous and increasing Kirchhoff function, the nonlinearity f: RN× R→ R is a Carathéodory function that obeys some conditions which will be stated later and V∈ C(RN, R+) is a non-negative potential function. We first establish the Bartsch–Pankov–Wang type compact embedding theorem for the fractional Sobolev spaces. Then multiplicity results are obtained by using the variational method, (S+) mapping theory and Krasnoselskii’s genus theory.

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  • MakaleAçık Erişim2018Scopus SJRQ1
    Glucan type exopolysaccharide (EPS) shows prebiotic effect and reduces syneresis in chocolate pudding

    İspirli, Hümeyra; Demirbaş, Fatmanur; Dertli, Enes

    Exopolysaccharides (EPS) of lactic acid bacteria are important biopolymers that can improve the physicochemical properties of food products and act as prebiotics. In this study the physicochemical role and the prebiotic effects of a glucan type EPS with (α1-3) and (α1-6) linkages were assessed in chocolate pudding containing Lactobacillus rhamnosus GG as a probiotic strain. The functions of EPS were determined by developing three different formulations: control, probiotic (Lactobacillus GG) and symbiotic pudding (Lactobacillus GG + EPS) samples. The pH and acidity of the symbiotic pudding sample were higher than the probiotic and the control samples during the 28-day of storage period. Similarly, an important level of increment in Lactobacillus GG levels in symbiotic sample was observed compared to the probiotic sample suggesting the prebiotic role of the α-glucan. Importantly, the syneresis in symbiotic pudding sample reduced significantly compared to other pudding samples which is related with the physicochemical role of glucan type EPS. This study reveals the prebiotic and physicochemical roles of α-glucan type EPS in a chocolate pudding model.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus33WoS28OpenAlex35
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  • Dergi
    Transactions of the Indian Institute of Metals
  • Dergi
    Protein Journal
  • Dergi
    Indian Journal of Microbiology
  • Dergi
    Radiation and Environmental Biophysics
  • Dergi
    International Journal for the Advancement of Counselling
  • Dergi
    Journal of Low Temperature Physics
  • Dergi
    Journal of Vibration Engineering and Technologies
  • Dergi
    Korean Journal of Chemical Engineering
  • Dergi
    Journal of the Australian Ceramic Society