Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(74)
- Akkurt, Nevzat(39)
- Celik, Erkan(35)
- Serdar, Osman(35)
- Güler, Ömer(33)
- Kutlu, Banu(32)
- Paksoy, Mehmet Yavuz(32)
- Yucesan, Melih(31)
- Tekin, H.O.(30)
- Yildirim, Numan(30)
- Yildirim, Nuran Cikcikoglu(30)
- ALMisned, Ghada(28)
- Mete, Suleyman(26)
- Danabas, Durali(20)
- Ince, Muharrem(20)
- Serin, Faruk(20)
- Ates, Mehmet(19)
- Can, Erkan(19)
- Onat, Onur(18)
- Benzer, Fulya(17)
- Kocabaş, Mehmet(17)
- Tanyol, Mehtap(17)
- Kizak, Volkan(16)
- Alataş, Mevlüt(15)
- Aydin, Rahmi(15)
- Kahraman, Gökhan(15)
- Kilic, G.(15)
- Polat, Alper(15)
- Susam, Selim Orhun(15)
- Xu, Qian(15)
- Aslan, Naim(14)
- Guler, Omer(14)
- Gürler, Nedim(14)
- Karatay, Gülnaz(14)
- Utku, Anıl(14)
- Yildirim, N. C.(14)
- Özkul, İskender(14)
- Demirol, Ferhat(13)
- Erguven, Gokhan Onder(13)
- Firat, Erhan(13)
Yayınlar
- MakaleYalnız künye2019Scopus SJRQ2Investigation of selective leaching and kinetics of copper from malachite ore in aqueous perchloric acid solutions
Tanaydın, Mehmet Kayra; Demirkıran, Nizamettin
In this study, the leaching kinetics of malachite in perchloric acid solutions was investigated. The dissolution behaviors of copper, zinc, and iron in the ore matrix were determined at different acid concentrations and reaction temperatures. It was observed that the concentration of perchloric acid had a major effect on the dissolution of copper, zinc, and iron. It was determined that the effect of temperature on the dissolution of these species was not as significant as concentration impact. The results obtained shown that copper in the ore matrix was completely leached while zinc and iron were partially dissolved in perchloric acid solutions. In addition, the effects of the acid concentration, reaction temperature, stirring speed, particle size, and solid-to-liquid ratio on the leaching of malachite were researched. In these experiments, it was observed that the leaching rate of copper increased with increasing solution concentration, stirring speed, and reaction temperature, and with decreasing solid-to-liquid ratio and particle size. A kinetic analysis was performed, and it was found that the rate of leaching reaction obeyed the mixed kinetic control model in the unsteady state. The activation energy of the leaching process was calculated to be 34.69 kJ/mol.
AtıfScopus19WoS16OpenAlex20
İncele - MakaleYalnız künye2019Scopus SJRQ2Risk assessment for clearing and grading process of a natural gas pipeline project: An extended TOPSIS model with Pythagorean fuzzy sets for prioritizing hazards
Oz, Nurdan Ece; Mete, Suleyman; Serin, Faruk; Gul, Muhammet
A natural gas pipeline project is a broad construction system consisting of both offshore and onshore section, which aims to supply the natural gas to one country to another. In such these projects, main focus of the works should cover workplace, environment, health, and safety of workers and employers. To achieve this, a new occupational health and safety (OHS) risk assessment is necessary for reducing the negative effects of emerged risks. In this article, a fuzzy-based risk model is developed for prioritizing primary and residual risk. A two-dimensional (2D) risk matrix method is initially performed and the Pythagorean fuzzy technique for order preference by similarity to ideal solution (PFTOPSIS) method is then used to prioritize previously identified hazards. For the prioritization of primary and residual risks, hazards are assessed against two parameters (probability and severity) of 2D risk matrix. Unlike previous risk assessment studies, PFTOPSIS is applied for the first time. The fuzzy model is applied to a case study for clearing and grading process of a natural gas pipeline project. A sensitivity analysis is also performed on parameter weights in order to validate the model.
AtıfScopus93WoS80OpenAlex97İncele - MakaleYalnız künye2019Scopus SJRQ1A decision-support system based on Pythagorean fuzzy VIKOR for occupational risk assessment of a natural gas pipeline construction
Mete, Suleyman; Serin, Faruk; Oz, Nurdan Ece; Gul, Muhammet
Natural gas pipeline construction projects are major projects between countries that include onshore and offshore sections. Aim of these projects is to supply the natural gas from one place to another. Safety of workplace, environment and employers is also another important argument. In this respect, it is essential to conduct an occupational risk assessment (ORA) study to eliminate the risks that may arise around the pipeline. Application of multi-criteria decision analysis (MCDA) methods for the ORA has shown great increase recently. Also, developing a decision support system (DSS) which is easy to use and capable of extracting results enables decision makers to assess health and safety risks. Therefore, (i) A DSS based on Pythagorean fuzzy VIKOR (PFVIKOR) in ORA literature is developed for the first time; (ii) A case study is employed to risk assessment for trenchless crossings installation by auger boring process of the pipeline project; (iii) A sensitivity analysis is performed in the results of PFVIKOR-based DSS; and (iv) Two additional risk parameters called sensitivity to PPE non-utilization and undetectability are considered in ORA process apart from the classical risk assessment parameters of severity and probability. Developing such a DSS and applying it for risk assessment in a natural gas pipeline construction will contribute stakeholders in the energy industry.
AtıfScopus89WoS67OpenAlex83İncele - MakaleYalnız künye2019Scopus SJRQ2Two remarkable moss species new to Turkey and South-west Asia
Batan, N.; Alataş, M.; Erata, H.; Özdemir, T.
Bryum blindii and Dicranella crispa are reported new to Turkey and South-west Asia following a recent bryological excursion to the Ardahan and Burdur regions of Turkey. Illustrations, geographic distribution and comparisons with morphologically similar taxa are given.
AtıfScopus5WoS5OpenAlex16İncele - MakaleYalnız künye2019Scopus SJRQ2Synthesis, characterization and spectroscopic investigation of N-(2-acetylbenzofuran-3-yl)acrylamide monomer: Molecular structure, HOMO–LUMO study, TD-DFT and MEP analysis
Barim, E.; Akman, F.
In this study, a novel acrylamide monomer was synthesized and characterized by UV-Vis, FT-IR and 1H NMR measurements. The acrylamide monomer namely, N-(2-acetyl-benzofuran-3-yl)acrylamide (NABA), was prepared in two steps. In the first step, 1-(3-aminobenzofuran-2-yl)ethan-1-one was synthesized by the reaction of 1-chloroacetone with 2-hydroxy-benzonitrile under basic conditions. In the second step, the obtained 1-(3-aminobenzofuran-2-yl)ethan-1-one was reacted with acryloyl chloride and triethylamine at 0–5 °C temperature for obtaining NABA monomer. Then, the structural, vibrational, nuclear magnetic resonance and electronic properties for the synthesized monomer were determined by quantum chemical calculations of DFT method. The results were compared with experimental FT-IR, 1H NMR and UV–Vis spectral data. The band gap of HOMO and LUMO show that the NABA monomer is chemically active and has charge transfer within the monomer. Moreover, molecular electrostatic potential (MEP) maps were drawn to identify reactive regions of NABA monomer.
AtıfScopus104OpenAlex107İncele - MakaleYalnız künye2019Scopus SJRQ1Supply-driven rebalancing of disassembly lines: A novel mathematical model approach
Mete, Suleyman; Çil, Zeynel Abidin; Celik, Erkan; Ozceylan, Eren
In recent years, the interest of disassembly line has increased owing to the economic reasons and increase of environmental awareness. The balancing of the disassembly line is one of the factors affecting directly the performance of the process. Companies with a line used effectively can gain many advantages in terms of economic aspect and it facilitates competition the companies with others. Moreover, uncertainties end-of-life products characteristics and quantity of supply/demand causes reassigned of task and altering cycle time. Rebalancing of disassembly line is required in this situation. In this study, a novel mixed integer programming model is proposed. Firstly, disassembly line balance is created, and then according to the given new supply, tasks are reselected and reassigned to the workstations. A real case study is presented. The generated test problems are also analyzed using proposed mathematical model. Through the analysis of rebalancing the existing disassembly line, it has been identified that an existing balance might have been changed to accommodate changes in the desired output rate in order to cope up with the variation of the cycle time.
AtıfScopus31WoS27OpenAlex31İncele - MakaleYalnız künye2019Scopus SJRQ1Investigation ofthe gamma ray shielding parameters of (100-x)[0.5Li2O–0.1B2O3–0.4P2O5]-xTeO2 glasses using Geant4 and FLUKA codes
Aşkın, A.; Sayyed, M.I.; Sharma, Amandeep; Dal, M.; El-Mallawany, R.; Kaçal, M.R.
In the present work, the radiation shielding proeprties of lithium borophosphtellurite glass system with the composition of (100-x) [0.5Li2O-0.1B2O3–0.4P2O5]-xTeO2 (x = 0, 10, 20, 30 and 40 mol%) were reported. The mass attenuation coefficient (μ/ρ) of the selected glass system (LiBPTe0, LiBPTe10, LiBPTe20, LiBPTe30 and LiBPTe40) was calculated at 356 keV, 662 keV, 1173 keV and 1330 keV photon energies by using Geant4 and FLUKA codes and the results were compared to the values obtained theoretically using WinXcom software. The correlation theory has been used to calculate the correlation coefficients (R2) between the results from WinXcom and the both simulations codes (Geant4 and FLUKA) for each sample. Moreover, some other radiation shielding parameters such as effective atomic number, photon transmission, mean free path and half value layer were calculated. The gamma photon transmission results showed that the transmission values of the 356 keV photons are lower than those of energies 662, 1173 and 1330 keV. At 356 keV, the transmission value for LiBPTe0 (at 6 cm thickness) is found to be 0.245 while at the same energy and thickness the transmission value is 0.088 for LiBPTe40. Out of all the glasses considered in present work, LiBPTe40 possesses the highest values of effective atomic number (Zeff). The Zeff values for the present glasses are 8.02, 9.55, 11.16, 12.85 and 14.64 for LiBPTe0, LiBPTe10, LiBPTe20, LiBPTe30 and LiBPTe40 respectively at 356 keV. The mass attenuation coefficient and effetive atomic number results showed that utilization 40% mol of TeO2 significantly improves the gamma ray shielding properties of the selected glass system. The shielding effectiveness of the selected samples was compared with other reference materials namely two radiation shielding glasses and four concretes used in different shielding purposes in terms of the mean free path (MFP) at 356 keV. The results revealed that the MFP of RS-253-G18 is lower than LiBPTe0sample. Moreover, the MFP of ordinary concrete is higher than the MFP of all glasses under examination, thus the investigated tellurite glasses have better attenuation features than the ordinary concrete.
AtıfScopus106OpenAlex107İncele - MakaleYalnız künye2019Scopus SJRQ2Regulation of signaling pathways by β-elemene in cancer progression and metastasis
Qureshi, Muhammad Z.; Attar, Rukset; Romero, Mirna A.; Sabitaliyevich, Uteuliyev Y.; Nurmurzayevich, Sadykov B.; Ozturk, Ozlem; Wakim, Lara H.; Lin, Xiukun; Ozbey, Ulku; Yelekenova, Armida Bakhytbekovna
Entry of β-elemene into various phases of clinical trials advocates its significance as a premium candidate likely to gain access to mainstream medicine. Based on the insights gleaned from decades of research, it seems increasingly transparent that β-elemene has shown significant ability to modulate multiple cell signaling pathways in different cancers. We partition this multicomponent review into how β-elemene strategically modulates various signal transduction cascades. We have individually summarized regulation of tumor necrosis factor related apoptosis-inducing ligand, signal transducers and activators of transcription, transforming growth factor/SMAD, NOTCH, and mammalian target of rapamycin pathways by β-elemene. Last, we will discuss the results of clinical trials of β-elemene and how effectively we can use these findings to stratify patients who can benefit most from β-elemene.
AtıfScopus33OpenAlex33
İncele - MakaleYalnız künye2019Scopus SJRQ2Pollen morphology of three Chrysophthalmum schultz bip. (Asteraceae) species in Turkey
Karlıoǧlu Kılıç, Nurgül; Paksoy, Mehmet Yavuz; Özdemir, Emrah
The pollen morphology of three species of the genus Chrysophthalmum Schultz Bip. (Asteraceae) found in Turkey were studied with light microscope (LM) and scanning electron microscope (SEM). The three species were C. dichotomum Boiss. & Heldr., C. gueneri Aytac & Anderb., and C. montanum (DC.) Boiss. Pollen grains of the Chrysophthalmum species were identified as spheroidal and their apertures were shown to be tricolporate. The polar and equatorial axes, distance between colpus apices, length/width of colpus, length/width of porus, exine thickness, and length/base of spine were measured on the pollen grains. Pollen ornamentation of the three species was identified as echinate in LM and echinate-microperforate in SEM. These studied species were distinguished from each other using Kruskal–Wallis and Dunn’s test. The results indicate that pollen characteristics could be useful for distinguishing the examined species.
AtıfWoS1OpenAlex1İncele - MakaleYalnız künye2019Scopus SJRQ2Gammarus pulex as a Model Organism to Assess the Residual Toxicity of Slaughterhouse Wastewater Treated by Electrocoagulation Process
Yildirim, Nuran Cikcikoglu; Tanyol, Mehtap; Serdar, Osman; Yildirim, Numan
It was assessed the efficiency of the electrocoagulation (EC) in slaughterhouse wastewater (SW) treatment by using antioxidant parameters of Gammarus pulex. The SW was treated by EC. Superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities and malondialdehyde (MDA) levels in G. pulex exposed to pre- and post-treated of the SW during 24 h and 96 h were analysed. Standard methods were applied during the analysing process of the physicochemical quality parameters for both untreated and treated SW. All measured physicochemical parameters were decreased following the treatment process via EC. After the treatment process, it was observed that while SOD activities and MDA levels were decreased, CAT activities were increased and GPx activities did not exhibit any change. In conclusion, the present study demonstrated the abilities of untreated SW to promote oxidative stress in model organism. The SOD, CAT activities and MDA levels in G. pulex revealed that EC process were efficient in the SW treatment.
AtıfScopus10WoS9OpenAlex13İncele - MakaleYalnız künye2019Scopus SJRQ4Evaluation of a new computer method (ANNs) and traditional methods (LWRS and VBGF) in the calculation of some growth parameters of two cyprinid species
Ozcan, Ebru Ifakat; Serdar, Osman
Artificial Neural Networks (ANNs) are a very reliable computer program used in many areas such as growth parameters. The aim of this study to compare the growth estimates of tigris scraper (Capoeta umbla (Heckel, 1843)) and kura barbel (Barbus lacerta (Heckel, 1843) captured from Karasu River (East Anatolia, Turkey) between 2014 and 2016. The age groups were 0-9 for C. umbla and 0-8 for B. lacerta. The estimated parameters of von Bertalanffy growth equations were as L' =51.96 cm, W' 804.16 g, k=0.092 year-1, t0=-1.763 year for C. umbla and L' 32.23 FP, W' 435.87 J, k 0.127\HDU-1, t0-2.489 for B. lacerta. The growth performance index (Y) value was comput-ed as 2.395 for C. umbla and 2.120 for B. lacerta. The length and weight relationships for two fish species were as follows: W=0.0092L3.05 (R²=0.98) and W=0.0095L3.07 (R2=0.98). The growth of these two cyprinid species were isometric growth. A ANNs model is a interdepented system containing many neurons. There are three different layers in a neural network (input, hidden and output layers). Data enters (length/weight, age, sex) at the inputs and passes along the network, by layer, till it reach-es at the outputs (weight/length). MATLAB Ver R2016a (Neural Network Toolbox) was used for ANNs estimatings. MAPE (%) equation was used to compare ANNs and other methods. According to the comparison of the results obtained with MAPE (%), ANNs provide better results than the LWRs and VBGF. The results of this study could give useful insight that ANNs can be evaluated as an alternative for growth prediction.
AtıfScopus9İncele - MakaleYalnız künye2019Scopus SJRQ1Assessment of hydraulic properties of technosols using Beerkan and multiple tension disc infiltration methods
Yilmaz, Deniz; Bouarafa, Sofia; Peyneau, Pierre-Emmanuel; Angulo-Jaramillo, Rafael; Lassabatere, Laurent
The increasing global urban sprawl requires large amounts of materials, putting huge pressure on numerous natural resources. In particular, vast quantities of soils are used to create infrastructures or green spaces associated with new developments. Alternative solutions aimed at alleviating soil consumption are thus being encouraged. Creating urban soils by recycling waste from industrial and construction activities is feasible, but apart from their support function the resulting technosols should also be able to provide some ecosystem services such as the capacity to infiltrate water and filter contaminants. Various methods are routinely used for in situ characterization of the hydraulic behaviour of natural soils, but their ability to assess the hydraulic properties of technosols remains unclear. Indeed, technosols formed from recycled waste differ markedly from natural soil because they often contain a considerable proportion of coarse artefacts that affect their structure. In this study, results obtained by two distinct methods (ponding and tension infiltrometry), associated with two data processing methods (Beerkan estimation soil transfer (BEST) and numerical inversion), on a set of infiltration data measured on experimental plots made of technosols have been compared with each other. Both methods provided similar results and thus proved to be reliable when applied to technosols. Highlights: Reuse of by-products from anthropogenic activities is crucial to alleviate the consumption of natural soil. Hydraulic properties of technosols must be monitored to assess some of the ecosystem services they can provide. BEST and numerical inversion of multiple tension disc infiltration data gave consistent results. Reliability of the hydraulic characterization methods used for technosols deserves further inquiry.
AtıfScopus10WoS10OpenAlex12İncele - MakaleYalnız künye2019Scopus SJRQ2Apigenin as an effective anticancer natural product: Spotlight on TRAIL, WNT/β-catenin, JAK-STAT pathways, and microRNAs
Ozbey, Ulku; Attar, Rukset; Romero, Mirna Azalea; Alhewairini, Saleh S; Afshar, Behnaz; Uteuliev, Yerzhan Sabitaliyevich; Hanna-Wakim, Lara; Ozcelik, Beraat; Farooqi, Ammad Ahmad
Wealth of information gleaned from decades of high-impact research work; scientists have disentangled the complicated web of versatile regulators that underlie cancer development and progression. Use of structural biology approaches and functional genomics have helped us to gain new insights into complex nature of cancer, and it is now clear that genetic/epigenetic mutations, overexpression of oncogenes, inactivation of tumor suppressors, loss of apoptosis, and versatility of protein binding partners have contributory roles in carcinogenesis and metastatic spread. It is becoming progressively more understandable that reprogramming of gene expression during and nontranscriptional changes during cancer development and progression are initiated and controlled by deregulated signal transduction cascades, all of which collectively create an incalculable complexity. Data obtained through preclinical and clinical trials revealed that alterations in the targeted oncogenes and other downstream, and parallel pathways played a central role in the development of resistance against different therapeutics. Phytochemicals have regained limelight, and different natural products are currently being tested for efficacy in preclinical studies. Apigenin, a plant-derived flavonoid has considerable pharmacological value and is reportedly involved in the regulation of different signaling cascades. In this review, we have attempted to summarize rapidly evolving understanding of molecular biologists and pharmacologists about the potential of apigenin in the regulation of deregulated signaling pathways in different cancers. We have emphasized on the regulation of WNT/β-catenin and janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. We also comprehensively discuss how apigenin restored apoptosis in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant cancers. The review also gives a snapshot of microRNAs (miRNAs) that regulate wide-ranging biological processes, and it is now clear that each miRNA can control hundreds of gene targets. Apigenin was noted to upregulate miR-520b and miR-101 in different cancers to inhibit tumor growth. Moreover, apigenin-induced apoptotic rate was significantly higher when used in combination with miR-423-5p inhibitors or miR-138 mimics. Better comprehension of linear and integrated signaling pathways will be helpful in effective therapeutic targeting of deregulated signaling pathways to inhibit/prevent cancer.
AtıfScopus65OpenAlex66İncele - MakaleYalnız künye2019Scopus SJRQ2Experimental investigation of transverse loading on composite panels coated with different gelcoat colors subjected to UV radiation and hygrothermal aging
Dogan, Akar; Arman, Yusuf; Ozdemir, Okan
This study focuses on the effects of hygrothermal and UV radiation aging on the reinforced epoxy composites coated with gelcoat. The aim of this study is to investigate the influence of gelcoat colors on the tensile properties, impact behavior and thermodynamic properties of the composite panels after the aging process has been performed. Two different gelcoat colors were chosen as black and yellow. Unidirectional E-glass fiber fabrics with an areal density 300 g m-2 as reinforcement and epoxy matrix were used. Vacuum-assisted resin infusion molding (VARIM) method was used to manufacture composite panels. The tensile test specimens were prepared according to ASTM standards. Tensile strength of both fiber and transverse directions, the impact perforation threshold, and stroge modulus of the aged samples decreased compared to unaged (virgin) samples. However, the drop in mentioned properties for coated materials is less than for uncoated materials, especially in yellow coated materials. The temperature of hygrothermal conditions significantly affected the perforation threshold. Moreover, the tensile strength in transverse direction in yellow samples decreased approximately 13%, while it decreased 23% in the black coated samples. Impact perforation threshold of unaged (virgin), uncoated, coated with yellow gelcoat and coated with black gelcoat is obtained to be 75, 57, 65 and 61 J, respectively.
AtıfScopus12WoS9OpenAlex11İncele - MakaleYalnız künye2019Scopus SJRQ2Synthesis, physical, structural and shielding properties of newly developed B2O3–ZnO–PbO–Fe2O3 glasses using Geant4 code and WinXCOM program
Rammah, Y.S.; Askin, A.; Abouhaswa, A.S.; El-Agawany, F.I.; Sayyed, M.I.
New zinc lead borate glasses with (50B2O3–10ZnO–(40 − y) PbO)–yFe2O3: 0 ≤ y ≤ 10 wt%) composition were synthesized by the conventional melt-quench technique. The amorphous nature of the glasses was tested by using X-ray diffraction spectroscopy. FTIR spectra for the glasses were recorded in the range of 4000–400 cm−1. Physical properties of the proposed glasses were evaluated. The mass attenuation coefficients (μ/ρ) for the glasses were calculated by the Geant4 simulation toolkit code and XCOM software within the photon energy range 365–2510 keV. Different γ-ray shielding parameters such as half-value layer, tenth value layer, and transmission fraction for the proposed glasses were evaluated using the obtained values of the (μ/ρ). Results reveal that for 1 cm glass thickness, the (50B2O3–10ZnO–30PbO)–10Fe2O3 sample has the highest transmission, due to the lower amount of Pb, and thus poorer shielding capability among the other glass samples. In addition, the probabilities of γ-ray interaction with the studied glasses were investigated.
AtıfScopus62OpenAlex64İncele - Derleme MakaleYalnız künye2019Scopus SJRQ1Designing the airport service with fuzzy QFD based on SERVQUAL integrated with a fuzzy multi-objective decision model
Kayapınar, Sema; Erginel, Nihal
Airport service quality is a crucial issue in the transportation industry. Although many studies focus on service quality and measurement of the airports, only a small number of studies that consider linguistic expression and fuzzy approach exist in the literature. This study aims to propose a new integrated approach to develop airport service quality. An integrated approach involving fuzzy Quality Function Deployment (QFD) based on SERVQUAL is used to measure airport service quality and to determine fuzzy weights of technical design requirements. Firstly, passengers’ needs are prioritised by using the SERVQUAL method and gap scores, then QFD matrix is constructed by defining fuzzy relationships between passengers’ needs and expectations, and technical design requirements under imprecise knowledge. Technical design requirements are weighted by using fuzzy QFD matrix as fuzzy numbers. Finally, a fuzzy multiple objective decision model is proposed to select the significant technical design requirements with two objectives: maximising the total fuzzy weights of technical design requirements and minimising the fuzzy technical difficulty level under a fuzzy budget constraint. A two-phase approach is used to solve the constructed fuzzy multi-objective decision model. The final results indicate four design requirements named as ‘the number of information board’, ‘capacity of wi-fi’, ‘emergency help button and automation’, and ‘the number of the signboard’, which maximise the total fuzzy weights of technical design requirements and minimise the sum of the fuzzy technical difficulty of each design requirements under the fuzzy budget constraint. This study is a real-world application which was implemented at the Anadolu University Airport in Turkey.
AtıfScopus40WoS37OpenAlex47İncele - MakaleYalnız künye2019Scopus SJRQ3Effect of L-Tryptophan on Sperm Quality of Tigris Scraper (Capoeta umbla) (Pisces: Cyprinidae) after Cryopreservation
Kutluyer, F.; Aksu, Ö.; Kocabaş, M.
BACKGROUND: The aromatic amino acid L-tryptophan is a versatile molecule and needed for the biosynthesis of proteins. Due to metabolic functions, it has been widely used in research and clinical trials. OBJECTIVE: The present study aimed to test the usefulness of L-tryptophan as an extender of Tigris scraper (Capoeta umbla) sperm during cryopreservation. MATERIALS AND METHODS: Semen samples were diluted with a ratio of 1:3 (sperm: extender) and base extenders were supplemented with L-tryptophan (0 mM, 0.5 mM, 1 mM, 2 mM and 4 mM). Sperm motility and duration of post-thawed samples were assessed after the cryopreservation process. RESULTS: Our results revealed that motility rate and duration of sperm increased when the cryomedia was supplemented with L-tryptophan. On the other hand, an increase in the concentration of L-tryptophan in the extender caused a significant decrease (p<0.05) in the motility rate of Tigris scraper (C. umbla) sperm. The ideal results were obtained at 1 mM L-tryptophan; however, no motile sperm were shown in any samples when a concentration of 2 mM was used. CONCLUSION: The current study shows the importance of conducting further studies related to long-term storage and reproduction management.
AtıfScopus12WoS12İncele - MakaleYalnız künye2019Scopus SJRQ3Utilizing hydrolyzed powder recyclates as filler in polystyrene; [Verwendung von hydrolisierten Pulverlackrecyclaten als Füllstoff in Polystyrol]
Kismet, Y.; Wagner, M.H.
In the present study, hydrolyzed powder coating wastes were used as filler materials in polystyrene compounds, and the effect on the mechanical properties, melt flow index and density of polystyrene compounds were investigated. Epoxy/polyester, epoxy and polyurethane systems with thermoset structure were used as powder coating recyclates. After separately hydrolyzing these wastes, 5 %, 10 %, 20 % and 30 % by weight were homogeneously mixed with polystyrene, initially mechanically and subsequently with an extruder in the melt at 180 °C. The resulting compounds were cooled and granulated, and by use of an injection molding machine at 180 °C to 200 °C, standard tensile test bars were produced. Tensile strength, bending strength and izod impact strength of the test bars were measured and the variations of the mechanical properties of the polystyrene compounds as a function of the type and amount of filler were examined. In addition, melt flow index and density of the compounds were determined. Furthermore, the bonding mechanism of filler and matrix material was examined by electron microscopy.
AtıfScopus2WoS2OpenAlex3İncele - MakaleYalnız künye2019Scopus SJRQ1Risk evaluation and prevention in hydropower plant operations: A model based on Pythagorean fuzzy AHP
Yucesan, Melih; Kahraman, Gökhan
Hydropower generation facilities are becoming increasingly popular in many parts of the world. One of the main reasons for this situation is that the resource reserves such as coal, petroleum and natural gas, which are called conventional energy sources, decrease day by day and their prices rise. So the efficient operation of hydroelectric power plants has become very important. When these plants are operated, it is possible to cause many hazards, including injury, illness, death, damage to the environment, property and equipment. In this study, it is aimed to perform risk assessment for hydroelectric power plants using Pythagorean fuzzy Analytical hierarchy process (PFAHP) method. The team of experts has identified twenty hazards and their results that could occur in the operation of the hydroelectric power plant. The weights of the hazards were determined by using linguistic expressions. Preventive measures have been taken for the three most important hazards. The results of this study are expected to contribute to the safety of hydropower plants and the prevention of financial losses.
AtıfScopus143WoS123OpenAlex147İncele - MakaleYalnız künye2019Scopus SJRQ1Flow past a hollow cylinder with two spanwise rows of holes
Firat, Erhan; Ozkan, Gokturk M.; Akilli, Huseyin
Abstract: The flow over fixed, hollow, rigid circular cylinders with and without two series of equally spaced holes of equal diameter (0.2 cylinder diameter) along the surface of the cylinder has been studied by means of dye injection flow visualization, particle image velocimetry (PIV), and force measurements. Holes are connecting the front and rear stagnation lines or the upper and lower sides (i.e., they are positioned at ± 90° from the stagnation line) of the cylinder. The center-to-center distance between holes was 7-hole diameter. The experimental data were obtained from water channel and wind tunnel measurements performed at Reynolds numbers of 6900 and 20000, respectively. It was found that cylinder with holes located on the surface at an angle ± 90° from the front stagnation line behaves like a double-chamber synthetic jet actuator when subjected to cross-flow. The interaction of synthetic jet arrays with external flow over the side surfaces instigates the three-dimensional instabilities in the near wake and produces a 14.4% drag reduction compared to the drag of a plain cylinder. It was shown that cylinder with holes located on the surface at angles of 0° and 180° from the front stagnation line also instigates the three-dimensional instabilities in the near wake, but the primary mechanism responsible for drag reduction is self-bleed through downstream holes. This system producing drag reduction was found to have a drag coefficient equal to about 78.9% of that for a plain cylinder. Important flow structures inside and behind the cylinders with holes were also identified. Graphic abstract: [Figure not available: see fulltext.].
AtıfScopus17WoS17OpenAlex16İncele