Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 5Citation - Scopus: 5Selective Leaching of a Mixed Nickel-Cobalt Hydroxide Precipitate in Sulphuric Acid Solution With Potassium Permanganate as Oxidant(Taylor & Francis inc, 2020-10-12) Hussaini, Shokrullah; Ichlas, Zela Tanlega; Top, Soner; Kursunoglu, Sait; Kaya, MuammerSelective leaching of a mixed nickel-cobalt hydroxide precipitate was investigated using potassium permanganate as oxidant in sulfuric acid solution. 94.9% Ni, 50% Co and 0.6% Mn were dissolved under the following conditions: sulfuric acid concentration of 0.75 M, potassium permanganate of 5 g/L, temperature of 30 degrees C, leaching duration of 60 min, solid-to-liquid ratio of 1/10, and stirring speed of 400rpm. The pregnant leach solution was subjected to a solvent extraction process. 98% Co and 99% Mn were extracted at pH 4.84 with 30% (v/v) Cyanex 272, leaving essentially all nickel in the raffinate. Based on the experimental results, a flowsheet is proposed.Article Citation - WoS: 34Citation - Scopus: 41Revisiting the Relationship Between Natural Gas Consumption and Economic Growth in Turkey(Taylor & Francis inc, 2015-01-12) Dogan, E.The objective of this study is to re-analyze the relationship between natural gas consumption (NGC) and economic growth (GR) for Turkey in a multivariate framework by including capital and labor as additional variables because several papers suggest that a bivariate model can suffer from omitted-variables bias. As compared to the findings of Isik (2010), who previously investigated the short-and long-run relationships between GR and NGC using a bivariate model, we find that the magnitude of the coefficient estimate of NGC become substantially smaller in the long-run and the sign of short-run estimate of NGC shift to negative after accounting for capital and labor as well. In addition to that covered by Isik (2010), we investigate the direction of causality between GR and NGC using the vector error correction model Granger causality approach, and reveal the evidence of feedback hypothesis for Turkey.Article Citation - WoS: 1Citation - Scopus: 1Parabolic and Cubic Acceleration Time Integration Schemes for Nonlinear Structural Dynamics Problems Using the Method of Weighted Residuals(Taylor & Francis inc, 2016-01-20) Cilsalar, H.; Aydin, K.Two algorithms are proposed for direct time integration of an equation of motion of structural dynamics problems. The performance of the proposed methods is examined by evaluating stability, order of accuracy, numerical dissipation, and algorithmic damping. The results show that critical time for instability of the proposed algorithms is larger than those of conditionally stable methods. The numerical dissipation is shown to be explicitly less than other methods. Furthermore, the proposed algorithms are non-dissipative in the low-frequency range and have favorable damping in mid-and high-frequency regimes. Three examples are carried out to evaluate the feasibility and effectiveness of the proposed algorithms.Article Citation - WoS: 7Citation - Scopus: 9Immunomagnetic Separation of B Type Acute Lymphoblastic Leukemia Cells from Bone Marrow With Flow Cytometry Validation and Microfluidic Chip Measurements(Taylor & Francis inc, 2020-10-22) Icoz, Kutay; Eken, Ahmet; Cinar, Suzan; Murat, Aysegul; Ozcan, Servet; Unal, Ekrem; Deniz, GunnurIn order to detect the blast cells from bone marrow of patients, one strategy is to first isolate the cells using immunomagnetic beads. The aim of this study was to report the experimental results of the immunomagnetic separation efficiency of the blast cells from bone marrow of pediatric leukemia patients. To test the efficiency of immunomagnetic separation, flow cytometry measurements at critical steps were performed. We here reported 94.5% capture efficiency for CD10 nano beads. Patients samples were also analyzed with a microfluidic chip to test the feasibility for further developments.Article Citation - WoS: 78Citation - Scopus: 83How Renewable Energy Consumption and Natural Resource Abundance Impact Environmental Degradation? New Findings and Policy Implications From Quantile Approach(Taylor & Francis inc, 2021-02-17) Altinoz, Buket; Dogan, EyupThe EKC literature has ignored the importance of natural resources on environmental degradation. Thus, this paper aims to investigate the impact of renewable energy consumption and the abundance of natural resources on CO2 emissions for a panel of 82 countries by using quantile regressions. Empirical results show that renewable energy consumption reduces CO2 emissions and its effect increases in higher quantiles. The impact on carbon emissions of natural resource abundance is negative at lower quantiles but positive at medium and higher quantiles. Also, the validity of the EKC hypothesis is confirmed for all quantiles, and an increase in trade openness and urbanization increases environmental degradation in lower and middle quantile levels; however, these determinants have negative impacts on carbon emissions at higher quantiles. Policy implications related to this outcome are further discussed in the study.Article Citation - WoS: 6Citation - Scopus: 7Exploring the Binding Capacity of Lactic Acid Bacteria Derived Bacteriocins Against RBD of SARS-CoV Omicron Variant by Molecular Simulations(Taylor & Francis inc, 2023-01-02) Erol, Ismail; Kotil, Seyfullah Enes; Ortakci, Fatih; Durdagi, SerdarThe changes in the SARS-CoV-2 genome have resulted in the emergence of new variants. Some of the variants have been classified as variants of concern (VOC). These strains have higher transmission rate and improved fitness. One of the prevalent were the Omicron variant. Unlike previous VOCs, the Omicron possesses fifteen mutations on the spike protein's receptor binding domain (RBD). The modifications of spike protein's key amino acid residues facilitate the virus' binding capability against ACE2, resulting in an increase in the infectiousness of Omicron variant. Consequently, investigating the prevention and treatment of the Omicron variant is crucial. In the present study, we aim to explore the binding capacity of twenty-two bacteriocins derived from Lactic Acid Bacteria (LAB) against the Omicron variant by using protein-peptidedocking and molecular dynamics (MD) simulations. The Omicron variant RBD was prepared by introducing fifteen mutations using PyMol. The protein-peptide complexes were obtained using HADDOCK v2.4 docking webserver. Top scoring complexes obtained from HADDOCK webserver were retrieved and submitted to the PRODIGY server for the prediction of binding energies. RBD-bacteriocin complexes were subjected to MD simulations. We discovered promising peptide-based therapeutic candidates for the inhibition of Omicron variant for example Salivaricin B, Pediocin PA 1, Plantaricin W, Lactococcin mmfii and Enterocin A. The lead bacteriocins, except Enterocin A, are biosynthesized by food-grade lactic acid bacteria. Our study puts forth a preliminary information regarding potential utilization of food-grade LAB-derived bacteriocins, particularly Salivaricin B and Pediocin PA 1, for Covid-19 treatment and prophylaxis.Communicated by Ramaswamy H. SarmaArticle Citation - WoS: 4Citation - Scopus: 2Development of High-Performance Nanostructured Aluminum and Its Constitutive Modeling(Taylor & Francis inc, 2023-10-11) Deka, Surja; Mozafari, Farzin; Mallick, Ashis; Thamburaja, Prakash; Gupta, ManojA new technique, an in-situ hot-extrusion-based synthesizing process, is proposed to develop high-performance nanocrystalline aluminum (nc-Al) with an optimally tuned strength-to-ductility ratio suitable for various technologically relevant applications. Comprehensive investigations are conducted by characterizing mechanical and microstructural properties to realize the influence of various synthesizing variables on the properties of the bulk nc-Al. Furthermore, a continuum-scale constitutive modeling approach is proposed based on dominant microstructural mechanisms of plastic deformation and implemented into a finite element solver using a user-defined material interface. It is shown that the proposed theory can provide a versatile platform to predict the nanocrystalline aluminum mechanical response quite well.Article Citation - WoS: 6Citation - Scopus: 6Concentration Study of a Specularite Ore via Shaking Table, Reverse Flotation, and Microwave-Assisted Magnetic Separation(Taylor & Francis inc, 2022-11-03) Al-Dhubaibi, Ammar Mahdi Ahmed; Vapur, Huseyin; Top, Soner; Sivrikaya, OsmanDespite the difficulties in pelletizing specularite-type refractory iron ores, the utilization of these resources is indispensable for the steel industry due to the increasing need for iron. This study investigated Fe recovery from a refractory iron ore using gravity separation, reverse flotation, and two-stage magnetic separation. Tilt angle and particle size had a significant effect on the grade and recovery of concentrates in shaking table tests. Gravity concentration at optimum conditions resulted in an iron concentrate with 64.47% Fe grade and 90.73% Fe recovery. In the reverse flotation tests, the frother and depressant substantially affected the Fe grade of concentrates while the collector influenced the Fe recovery. A 90% Fe recovery with 64.69% Fe grade was obtained within optimum flotation conditions. The Fe grades were raised to >67.5% in products after the first magnetic separation. The tailings of the first magnetic separation were subjected to the second magnetic separation after microwave-assisted roasting to increase the magnetic susceptibility. In the second magnetic separation, a concentrate containing 66.06% Fe was separated from the microwave-roasted non-magnetic material with 82.23% Fe recovery. To the best of our knowledge, the microwave-roasting method has been applied to a specularite-type refractory iron ore for the first time.Article Citation - WoS: 12Citation - Scopus: 14Combination of the Simple Additive (SAW) Approach and Mixture Design to Determine Optimum Cocoa Combination of the Hot Chocolate Beverage(Taylor & Francis inc, 2015-04) Dogan, Mahmut; Aktar, Tugba; Toker, Omer Said; Tatlisu, Nevruz BernaPhysicochemical (pH, brix, and color), sensory (color, taste, odor, mouthfeeling, consistency, bitter flavor, and general acceptability), and rheological properties of the hot chocolate beverages including different cocoa combinations were investigated in the present study. Cocoa type significantly affected all of the properties. Simple additive weighting approach was applied to obtain one score from seven different sensory parameters and simple additive weighting score was used in mixture design to determine optimum cocoa type or cocoa combination. Ostwald de Waele model described the flow behavior of the hot chocolate beverage samples with R-2 values ranged between 0.818 and 0.999. The consistency coefficient (K) and apparent viscosity at shear rate 50 s(-1) (eta(50)) were significantly affected by cocoa type found in the formulation of the beverage. The mixture design approach was performed in order to determine variation of the responses (physicochemical, sensory, and rheological parameters) as a function of cocoa concentration. Simple additive weighting scores were satisfactorily described by established equation as a function of cocoa concentration to be used in the formulation of the hot chocolate beverage (R-2 = 0.8645).Article Citation - WoS: 6Citation - Scopus: 6Arsenic Removal From Aqueous Solutions by Ultrafiltration Assisted With Polyacrylamide: An Application of Response Surface Methodology(Taylor & Francis inc, 2015-10) Varol, Bekir; Uzal, NigmetThe present work deals with removal of arsenic from aqueous solutions by ultrafiltration assisted with polyacrylamide as an environmental friendly complexing polymer. The system performance was evaluated in relation to quality of permeate in terms of operating variables as feed concentration of arsenic ions (C-o, gL(-1)), ratio of polymer to arsenic (r, w/w), and pH of feed solution. The effect of the operating variables and maximum arsenic removal efficiency was determined by adopting design of experiments and response surface methodology under different conditions for this polymer. The experimental data were analyzed with a second order polynomial model validated by statistical analysis. Based on the response model developed, the maximum removal efficiency, close to 100%, of arsenic ions has been obtained at optimum operating parameters as C-o: 150 gL(-1), r: 2, and pH 10.