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
- MakaleAçık Erişim2020Scopus SJRQ3Technological 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.
AtıfScopus11WoS7OpenAlex9
İncele - MakaleYalnız künye2020Scopus SJRQ1Impact of glucan type exopolysaccharide (EPS) production on technological characteristics of sourdough bread
İspirli, Hümeyra; Özmen, D.; Yılmaz, Mustafa Tahsin; Sağdıç, O.; Dertli, Enes
In this study, technological role of α-glucan with (α1-3) and (α1-6) glycosidic linkages produced by Lactobacillus reuteri E81 on sourdough rheology and bread texture was investigated. To achieve this, a glucan deficient ΔgtfA mutant was produced by the deletion of the glucansucrase gene from strain E81. By comparison of glucan-positive and glucan-negative strains for rheological properties of sourdough revealed that in situ α-glucan production resulted in higher elasticity in sourdough. However, no additional effect of in situ glucan on textural characteristics of bread was observed although addition of glucan ex situ at 0.09% level significantly decreased bread hardness. Scanning Electron Microscopy (SEM) images of lyophilized sourdoughs confirmed association of glucan and starch granules forming a film like structure in sourdough.
AtıfScopus71WoS58OpenAlex67İncele - MakaleAçık Erişim2020Scopus SJRQ1Gamma ray and neutron shielding characteristics of polypropylene fiber-reinforced heavyweight concrete exposed to high temperatures
Demir, İ.; Gümüş, M.; Gökçe, H.S.
The residual properties of shielding structures need to be redefined after exposure to elevated temperatures due to their probable radiological hazards on biodiversity. In this study, the effect of high temperatures on mechanical, gamma ray and neutron attenuation characteristics was determined for limestone, barite and siderite concrete shields reinforced with polypropylene fiber. The increase in temperature up to 600 °C reduced the ultrasonic pulse velocity and compressive strength values of these shields by 59% and 62%, respectively. A good linear correlation (R2 ≥ 0.97) was found between these values. While the gamma ray linear attenuation coefficients increased by 9% for barite concrete, and reduced by 15% for normal concrete and by 17% for siderite concrete at 600 °C, trivial fluctuations (from −1% to +7%) were observed at 300 °C. The neutron attenuation factors of these shields gradually reduced up to 31% with the increase of temperature. The performance of siderite concrete was found to be slightly better than that of barite concrete in terms of strength and neutron shielding characteristics. With the satisfactory linear attenuation coefficients at all energy levels of gamma rays, barite concrete seems to be the most suitable concrete type under high temperature risks.
AtıfScopus142WoS132OpenAlex150İncele - MakaleAçık Erişim2020Scopus SJRQ1Synthesis and characterisation of alternan-stabilised silver nanoparticles and determination of their antibacterial and antifungal activities against foodborne pathogens and fungi
Yilmaz, Mustafa Tahsin; İspirli, Hümeyra; Taylan, Osman; Dertli, Enes
In this study, alternan isolated from Lactobacillus reuteri E81 was used as the stabilising agent to produce alternan-stabilised silver nanoparticles (AgNPs-Alt) and AgNPs-Alt were characterized and their antibacterial and antifungal activities were tested. The formation and the stability of AgNPs-Alt were determined by UV–vis spectroscopy analysis. SEM and TEM analysis revealed the uniform morphology of AgNPs-Alt with an average size of ~50 nm. The crystalline nature of the AgNPs-Alt was confirmed by XRD analysis. The interactions of alternan functional groups with silver was observed by FTIR analysis and thermal characteristics of AgNPs-Alt were determined by DSC analysis. Finally, the antibacterial and the antifungal activities of AgNPs-Alt were tested and AgNPs-Alt revealed inhibitory effects to pathogenic strains at 0.25 mg ml−1 concentration and this activity was observed to be concentration dependent. For the antifungal activity, a higher level of AgNPs-Alt was required compared to the antibacterial activity.
AtıfScopus35WoS31OpenAlex36İncele - MakaleYalnız künye2020Scopus SJRQ1Natural radioactivity of barite concrete shields containing commonly used supplementary materials
Gökçe, H.S.; Canbaz Öztürk, B.; Çam, N.F.; Andiç-Çakır, Ö.
The recycling of hazardous materials within new composites has a sustainable importance as it contributes on the reduction of high radionuclide concentrations. In this study, the effect of cementitious materials i.e. viscosity modifier, silica fume and fly ash on the 226Ra, 232Th and 40K activity levels of barite concrete shields was researched by using different mixing compositions in terms of binder content, w/b ratio and the amount of supplementary cementitious materials. In comparison to cement, silica fume and fly ash used in the production of concrete shields were found to have significantly higher activity levels of 40K, as well as 226Ra, 232Th and 40K, respectively. The 226Ra, 232Th and 40K activity levels of concrete shields range between 2.2 and 20.7 Bq kg−1; 2.6 and 7.0 Bq kg−1; 51.5 and 89.3 Bq kg−1, respectively. These activity values were found similar or less than those of building materials in the world. These satisfactory results are mostly caused by the barite source which has lower radioactivity levels. The concrete mixture details used in the study caused significant variation in the natural radioactivity of barite concrete shields. The introduction of silica fume which has high 40K activity levels and fly ash with high 226Ra, 232Th and 40K activity levels compared to cement and barite aggregate, significantly increased the radiological hazard parameters, although all results were found to be below the limits recommended by international reports. In conclusion, 226Ra activity levels of the concrete shields were significantly increased (up to 8.4 times) by the variation of mix design parameters used in comparison with concrete mixtures that have the least 226Ra activity level. The 232Th and 40K activity levels were as well increased in relatively less amounts (1.7 and 0.73 times higher, respectively).
AtıfScopus22WoS20OpenAlex23İncele - MakaleAçık Erişim2020Scopus SJRQ2High-throughput phenotyping approach for screening major carotenoids of tomato by handheld raman spectroscopy using chemometric methods
Akpolat, Hacer; Barineau, Mark; Jackson, Keith A.; Akpolat, Mehmet Z.; Francis, David M.; Chen, Yu-Ju; Rodriguez-Saona, Luis E.
Our objective was to develop a rapid technique for the non-invasive profiling and quantification of major tomato carotenoids using handheld Raman spectroscopy combined with pattern recognition techniques. A total of 106 samples with varying carotenoid profiles were provided by the Ohio State University Tomato Breeding and Genetics program and Lipman Family Farms (Naples, FL, USA). Non-destructive measurement from the surface of tomatoes was performed by a handheld Raman spectrometer equipped with a 1064 nm excitation laser, and data analysis was performed using soft independent modelling of class analogy (SIMCA)), artificial neural network (ANN), and partial least squares regression (PLSR) for classification and quantification purposes. High-performance liquid chromatography (HPLC) and UV/visible spectrophotometry were used for profiling and quantification of major carotenoids. Seven groups were identified based on their carotenoid profile, and supervised classification by SIMCA and ANN clustered samples with 93% and 100% accuracy based on a validation test data, respectively. All-trans-lycopene and β-carotene levels were measured with a UV-visible spectrophotometer, and prediction models were developed using PLSR and ANN. Regression models developed with Raman spectra provided excellent prediction performance by ANN (rpre = 0.9, SEP = 1.1 mg/100 g) and PLSR (rpre = 0.87, SEP = 2.4 mg/100 g) for non-invasive determination of all-trans-lycopene in fruits. Although the number of samples were limited for β-carotene quantification, PLSR modeling showed promising results (rcv = 0.99, SECV = 0.28 mg/100 g). Non-destructive evaluation of tomato carotenoids can be useful for tomato breeders as a simple and rapid tool for developing new varieties with novel profiles and for separating orange varieties with distinct carotenoids (high in β-carotene and high in cis-lycopene).
AtıfScopus40WoS32OpenAlex48İncele - 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.
AtıfScopus1WoS1İncele - 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 - Derleme MakaleAçık Erişim2020Scopus SJRQ1Effects of umbelliferone isolated from the Ferulago pauciradiata Boiss. & Heldr. Plant on cecal ligation and puncture-induced sepsis model in rats
Kutlu, Z.; Celik, M.; Bilen, A.; Halıcı, Z.; Yıldırım, S.; Karabulut, S.; Karakaya, S.; Bostanlık, Delimustafaoğlu F.; Aydın, P.
Sepsis is a pathophysiological event involving systemic inflammatory response syndrome, multiple organ failure syndromes, and tissue damage. Overproduction of free radicals as a result of tissue damage during sepsis contributes to cellular toxicity, organ failure, and even mortality. Antioxidants, which scavenge free radicals, play a protective role against various diseases. Previous studies have shown that umbelliferone (UF) has antioxidant and anti-inflammatory effects. Since oxidative stress is naturally associated with sepsis-induced organ dysfunction, the application of antioxidant compounds could potentially illuminate the pathophysiology of sepsis, which does not yet have an effective treatment. The sepsis model induced by cecal ligation and puncture (CLP) was applied to rats. Different doses of UF (10░mg/kg, 20░mg/kg, and 40░mg/kg) on oxidant-antioxidant in septic rats, mRNA of inflammatory mediators such as tumor necrosis factor- α (TNF-α) and interleukin (IL)-1 its effects on expression levels were evaluated in lung, kidney, and liver tissues. When the lung, kidney, and liver tissues of septic rats were compared with those of the control group, it was found that UF administration increased dose-dependent superoxide dismutase activity and glutathione levels and significantly decreased malondialdehyde levels. The effects of UF administration on oxidative parameters were dose-dependent. The 40░mg/kg UF dose showed greater anti-oxidative properties than the 20░mg/kg and 10░mg/kg doses for all the evaluated parameters. Further, the TNF- α mRNA expression of the CLP +40░mg/kg group was reduced to a level comparable to that of the control group. UF has been found to be an effective molecule in reducing oxidative stress by supporting endogenous antioxidants and enhancing the scavenging effects of free radicals. The potent antioxidant property of UF may also be related to the suppression of the cytokine cascade during sepsis. The results suggest that UF administration may represent a new treatment for the prevention of lung, kidney and liver damage caused by septic conditions.
AtıfScopus22WoS21OpenAlex23İncele - 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 - Kitap BölümüAçık Erişim2020Scopus SJRQ4An updated portrait of numerical analyses on spout-fluidized bed incineration systems
Özahi, Emrah; Çutay, Arif; Abuşoğlu, Ayşegül; Tozlu, Alperen; Ivanov, V; Trojanowska, J; Machado, J; Liaposhchenko, O; Zajac, J; Pavlenko, I
Biodegradable wastes are becoming a serious problem in terms of health and ecological balance in parallel with the increasing of local and global populations in recent years. These wastes should be disposed in both efficient and eco-friendly ways. Considering biodegradable wastes as an energy source, it is necessary to be sure that those disposal methods should be focused on energy recovery. However, the existing waste disposal methods have not reached technologically targeted lines yet. It is very important that waste-to-energy recovery systems should have high energy conversion efficiency. Nowadays, there are many current studies based on the methods of wastes incineration. One of the most significant among these systems is fluidized or spout-fluidized bed incineration system. Unfortunately, the targeted points of the technological development of these systems in view of efficient energy recovery have not been reached yet. Existing incineration systems and current studies on this issue are generally concentrated on conventional fluidized bed systems. However, there are few studies of new generation spout-fluidized bed incineration systems which increase homogeneity and prevent waste from adhering to inner wall of a combustor. This study is focused on the conducted numerical studies in this research field. The latest developments and researches on both fluidized and spout-fluidized bed incineration systems will be investigated and discussed. The remarkable results will be pointed out by using the comparison in order to identify the gaps of the scientific literature.
- 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.
AtıfScopus19WoS14OpenAlex24İncele - 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 - 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