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 künye2021Scopus SJRQ1İkinci Katil [The Second Murderer]: A Turkish Adaptation of Shakespeare's Scottish Play, Macbeth
Öğütcü, Murat
Serhat Yiğit’s İkinci Katil (2017) is a Turkish adaptation of Shakespeare’s Macbeth. Reminiscent of Tom Stoppard’s Rosencrantz and Guildenstern are Dead (1966), it focuses on minor characters and their otherwise disregarded and peripheral microcosms. However, different from the post-modern self-reflexivity of Stoppard’s play, Yiğit uses an Aristotelian model in his play. Through its concentration on hitherto insignificant minor characters, non-self-reflexive intertextuality, and non-Brechtian acting, İkinci Katil departs both from conventional Shakespearean tragedies and conventionalised avant-garde post-Shakespearean interpretations of these tragedies. The construction of the stage and scenery allows to construct and to deconstruct the play and the source text’s interplay of textual allusions by setting the story of Macbeth to the periphery and the story of the Second Murderer, Warden, to the centre of the action. Therefore, this article will analyse Yiğit’s İkinci Katil and illustrate how the play borrows, adapts and transforms Shakespeare’s Macbeth.
AtıfScopus2WoS1OpenAlex3
İncele - MakaleYalnız künye2021Scopus SJRQ1Assessment of Seismic Behavior Factor of Code-Designed Steel–Concrete Composite Buildings
Etli, Serkan; Güneyisi, Esra Mete
In this study, the seismic behavior factor of steel–concrete composite buildings was examined. For this purpose, 5-, 10-, 15- and 20-story composite moment-resisting frame (CMRF) buildings having concrete-filled steel tube columns and composite beams were designed at medium ductility (DCM) and high ductility (DCH) levels as per the regulations of Eurocode 8. Examined DCM structures were designed for a PGA of 0.2 g while DCH structures were designed for a PGA of 0.4 g. SeismoStruct software was utilized in the design and performance assessment of the case study structures. Nonlinear static pushover and incremental dynamic analyses were used. In the pushover analysis, the uniform and triangular load distributions were adopted while 12 earthquake ground motions were employed in the dynamic analysis. The effect of ductility levels and number of stories on the seismic behavior of CMRFs was studied using the results of the nonlinear analysis. To this, the variation in the lateral response, global yielding value, code-based behavior factor and component, and dynamic behavior factor were presented for CMRF structures with DCM and DCH. It was observed that the behavior factor of all CMRFs exhibited well above the design assumptions, especially DCM class CMRFs.
AtıfScopus16WoS11OpenAlex34İncele - MakaleYalnız künye2021Scopus SJRQ2Effect of graphene reinforcement on hybrid bioceramic coating deposited on the produced porous Ti64 alloys
Aslan, N.; Aksakal, B.
Porous-Ti64 alloys (P-Ti64), produced at various porosities by hot-pressing technique with the help of Mg spacer, were coated by hybrid-Graphene Oxide (rGO) reinforced-hydroxyapatite (HAp), using the sol–gel method. The synthesized rGO powder was used in reinforcing HAp by the Modified Hummers method having 30 µm particle size and nano (nm) scale layer thickness. Hybrid coatings were executed on Ti64 substrates in four different groups as single-HAp, HAp reinforced with 0.5 wt%, 1.0 wt% and 1.5 wt% rGO for three different porosities (41, 52, and 64%) were characterized by FT-IR, Raman, XRD and SEM. The average 21 µm coating film thicknesses were obtained and desirably, the only superficial pores of the substrates were closed by coating material rather than the inner connected open pores. It was also shown that 0.5 wt% and 1.0 wt% rGO reinforcements into HAp prevented crack formation on the Ti64 surfaces, whereas 1.5 wt% rGo reinforcement and single-HAp coatings caused. The highest adhesion strength values were achieved at low porosities (41–52%) and of 0.5–1.0 wt% rGO reinforcements through the adhesion tests.
AtıfScopus14WoS12OpenAlex20İncele - DüzeltmeYalnız künye2021Scopus SJRQ1Corrigendum to “Influence of partial sodium replacement on proximate composition, physical and sensory quality of marinated anchovy (Engraulis encrasicolus)” [LWT 137 (2021) (February 2021) 110476] (LWT (2021) 137, (S002364382031464X), (10.1016/j.lwt.2020.110476))
Erol, Nida Demirtas; Erdem, Ömer Alper; Cakli, Sukran
The authors regret Arzu Burcu Yavuz who is one of the authors of our article requested to withdraw her name from our article titled “Influence of Partial Sodium Replacement on Proximate Composition, Physical and Sensory Quality of Marinated Anchovy (Engraulis encrasicolus).” As the other authors of the article, we agree with this request and have removed Dr. Burcu from this article. The updated authorship is as listed above. The authors would like to apologise for any inconvenience caused.
AtıfScopus1İncele - MakaleYalnız künye2021Scopus SJRQ2High temperature effect on quasi-static and low velocity impact behaviors of advanced composite materials
Karakuzu, Ramazan; Djele, Akim; Dogan, Akar
In this study, the effect of ambient temperatures on the punch shear and low-velocity impact behavior of S2 glass fabric and carbon-kevlar hybrid fabric reinforced epoxy composites was investigated. The quasi-static tests (QST) were performed by using a Universal Shimadzu Tensile Testing Machine with various crosshead speeds. Low-velocity impact (LVI) tests were also carried out by using the CEAST Fractovis Plus impact test machine at different impact energies. Flat-nose impactors with a cylindrical punch diameter of 12.70 mm were mounted to the test machines. Both tests have been carried out at various temperatures. After the experiments, the load-displacement, the absorbed energy-impact energy/crosshead speed and punch shear strength graphs are plotted. From the obtained results it can be said that, in penetration cases of low-velocity impact and quasi-static tests, absorbed energy and punch shear strength values show similar behavior for hybrid carbon-kevlar/epoxy at each temperature except for 80 °C while these values are different from each other for S2 glass/epoxy at all temperatures.
AtıfScopus16WoS14OpenAlex14İncele - MakaleYalnız künye2021Scopus SJRQ1Problem- based learning in live online classes: Learning achievement, problem-solving skill, communication skill, and interaction
Aslan, Alper
The purpose of the study is to investigate the effect of first aid training in live online classes using the problem-based learning approach on students' learning achievement, problem-solving skills, communication skill, and interaction. The pre-test and post-test quasi-experimental design with a control group was used in the quantitative dimension of the study. The study group was conducted with forty-five university students. While live online classes in the experimental group were carried out via the PBL approach, live online classes in the control group were traditionally carried out via teacher-based methods without any intervention. Zoom application was used in both groups during live online classes. Group work in the experimental group was conducted using breakout rooms. The process of data collection and the experimental procedure of the study was completed in six weeks. Within the scope of the study, courses took three 40 min periods every week. The Learning Achievement Test, the Perceived Problem-solving Skills Scale, the Communication Skills Scale, and the Online Course Interaction Level Determination Scale were used for data collection tools. The results of study show that students who attended live online classes using PBL had higher levels of learning achievement, problem-solving skills and live online class interaction than students who attended live online classes using teacher-based methods. No significant difference between the communication skills of the groups was observed.
AtıfScopus143WoS76OpenAlex229İncele - MakaleYalnız künye2021Scopus SJRQ2Examination of contact problem between functionally graded punch and functionally graded layer resting on elastic plane
Polat, Alper
In this study, continuous contact problem in the functionally graded (FG) layer loaded with a FG flat punch resting on the elastic semi-infinite plane was analyzed by the finite element method (FEM). It was assumed that the shear modulus and density of the layer and punch varied according to exponentially throughout their depth. FG layer's weight was included to the problem and additionally all surfaces were considered as frictionless. Analysis of FG materials was performed with a special macro which was added to the ANSYS program. Firstly, the shear modulus of the punch was considered to be very rigid and the results of initial separation load (λcr) and distance (xcr) were compared with the analytical solution. Afterwards, results obtained from the contact analysis made according to the inhomogeneity parameters (β, γ) between FG punch-FG layer which had been unprecedented in the literature were discussed. As a result, FG punch's stress values at the punch edges where stress accumulations occurred were found to be smaller than the rigid punch. The security of the structure, longer life of the material and ease of production are directly related to the reduction of the stress values. The results obtained in this study are important in this respect. Also this work is the first study that investigates the effect of FG punch on the FG layer.
AtıfScopus8WoS10OpenAlex2İncele - MakaleYalnız künye2021Scopus SJRQ2Cellular responses of spirlin Alburnoides bipunctatus spermatozoa exposed to Bisphenol A: Biochemical response and sperm quality alterations evaluation
Kocabaş, Mehmet; Kutluyer, Filiz; Çakir Sahilli, Yeliz; Aksu, Önder
Plastics are one of the global environmental problems owing to their highest production. Bisphenol A (BPA) is used in the manufacturing of plastics including polycarbonate, polyvinyl chloride and resins. In particular, aquatic ecosystems are adversely affected by the occurrence of micropollutants. In addition, BPA as a typical endocrine-disrupting chemical (EDC) seriously influences androgenic activity and reproduction of aquatic organisms, particularly fish as non-target organism. In toxicological assays, sperm cells can be used as a potential tool for reliable and practical assessment. For these reasons, sperm cells were exposed to lower concentrations (0 µg/L, 0.5 µg/L, 1.25 µg/L, 2.5 µg/L and 5 µg/L) of BPA and the study focused on BPA-induced oxidative stress. The enzymatic [glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD)] activities and lipid peroxidation (MDA) were analyzed in spermatozoa. The study findings showed that the activities of SOD and GSH-Px were significantly decreased by BPA but lipid peroxidation (MDA) and CAT acticity increased. Notably, the percentage and duration of motile sperm cells decreased. Collectively, spermatozoa clearly showed the sensitivity even at extremely low concentrations. This is first report to assess the impact of BPA on sperm cells of spirlin Alburnoides bipunctatus.
AtıfScopus6WoS6OpenAlex5İncele - MakaleYalnız künye2021Scopus SJRQ1Performance of marble powder on cementitious composites including waste steel chips as an additive
Gülmez, Nihan
The reuse of industrial waste materials in cement-based composites contributed to preventing increasing environmental problems and reducing production costs. This article examined the effectiveness of using recycled steel chips (Ast) from metal industry waste and waste marble powder (BMP) instead of cement and the possibility of obtaining eco-efficient specimen. While steel chips included in mortars as additives decreased workability, marble powder increased it. An increment in the level of substitution of steel chips resulted in a subsequent increase in water absorption percentages and apparent porosities of mortars. Maximum flexural strength was obtained in 2% steel chips-10% marble powder in waste system.
AtıfScopus16WoS15OpenAlex21İncele - MakaleYalnız künye2021Scopus SJRQ2Determination of Optimum Process Conditions by Central Composite Design Method and Examination of Leaching Kinetics of Smithsonite Ore Using Nitric Acid Solution
Tanaydın, Mehmet Kayra; Bakıcı Tanaydın, Zümra; Demirkıran, Nizamettin
The leaching behavior of Tunceli smithsonite ore in nitric acid was evaluated in two study steps including optimization of leaching process and kinetics modeling. The individual and synergistic effects of effective parameters such as nitric acid concentration, solid-to-liquid ratio, stirring speed, and temperature on the dissolution rate of zinc were investigated using central composite design. Four factors including temperature (30–50 °C), nitric acid concentration (0.2–0.5 mol/L), stirring speed (350–600 rpm), and solid-to-liquid ratio (0.004–0.01 g/L) were investigated. The dissolution percent of zinc (97%) was obtained in 120 min of leaching time: acid concentration 0.5 mol/L, temperature 50 °C, stirring speed 500 rpm, and solid–liquid ratio 2/500 g/mL at the optimum conditions obtained using the central composite design. The dissolution kinetics of smithsonite was examined according to heterogenous models and it was found that the dissolution rate was controlled by ash layer diffusion process. It was found that the leaching rate increased with increasing temperature, stirring speed, and acid concentration as well as decrescent particle size and solid/liquid ratio. The trial data were analyzed by statistical and graphical methods and the activation energy of this leaching process was determined to be 28.63 kJ·mol−1. Graphical Abstract: [Figure not available: see fulltext.].
AtıfScopus9WoS9OpenAlex10İncele - MakaleYalnız künye2021Scopus SJRQ1Relationship of knowledge about and attitudes towards violence with recognition of violence against women among health staff in pre-hospital emergency medical services
Gümüşsoy, Süreyya; Dönmez, Sevgül; Ekşi, Ali; Dal, Nursel Alp
Background: Domestic violence, specifically, violence against women, is prevalent in all segments of society regardless of social class, ethnicity, culture or country. In other words, domestic violence is a global concern. Aim: The study aims to investigate the relationship between the attitude and knowledge of the health staff in pre-hospital emergency medical services about violence against women and their recognition of such form of violence. Methods: This descriptive study was conducted on 1023 paramedics and emergency medicine technicians who work in the pre-hospital emergency health setting and are members of the Paramedic and Pre-hospital Emergency Medicine Association. The Attitudes towards Violence against Women Scale (ATVAWS) and Health Staff's Recognition of Signs of Violence against Women Scale (HPRSVAWS) were used for data collection. Results: The mean scores for the ATVAWS and HPRSVAWS were 46.68 ± 6.92 and 20.31 ± 3.23, respectively. Of the participants, 48.5% had been subjected to violence, 43.93% had been subjected to violence perpetrated by their mothers, 41.53% had been exposed to physical violence and 4.2% remain exposed to domestic violence. Participants who had been exposed and those who remain exposed to domestic violence produced high scores in ATVAWS, which indicates an improvement in the traditional approach (less opposing view) to violence. High scores in the ATVAWS for (a) those who were exposed to violence in their workplaces, (b) who had never attended to actual or suspected cases of violence against women in their professional life, (c) who had attended to seven or more cases of violence against women, (d) who were less competent in physically examining actual or suspected cases of violence and (e) who had not been trained on violence against women, which indicates an increase in the traditional approach to violence. Conclusion: The study found that health staff in emergency health stations better recognised the signs of violence against women as their attitudes towards violence were less similar to the traditional approach. That is, they mostly held non-violent views. The characteristics, attitudes, perceptions and values of health professionals were considered important factors in addressing violence.
AtıfScopus7WoS4OpenAlex10
İncele - MakaleYalnız künye2021Scopus SJRQ1Crack failure in hydrodynamically lubricated bearings: A case study hydraulic turbine
Taşgın, Yahya; Kahraman, Gökhan
This study investigates the trunnion crack of a 50 MW hydraulic turbine in the generator guide bearing. The crack area has been examined metallographically and the fixing method for the the trunnion crack has been explained. Result of the study shows that the reason for the formation of the bearing trunnion crack can be the thermal stresses that occur during the mounting of the bearing trunnion to the turbine shaft and the material fatigue that occurs during the operation of the hydraulic turbine.
AtıfScopus9WoS7OpenAlex9İncele - MakaleYalnız künye2021Scopus SJRQ3Investigation of the effect of baffle cut on heat transfer and pressure drop in shell-and-tube heat exchangers using CFD
Işık, Erdem; Tuğan, Volkan
The shell-and-tube heat exchanger (STHE) is one of the most widely used types of heat exchangers in industry. For this reason, studies conducted to improve the performance of STHEs are of great importance. In this study, a single-shell- and double-tube-pass STHE was designed, and a three-dimensional and steady-state flow analysis of this heat exchanger was conducted using the CFD method. The purpose of the analysis was to investigate the effect of baffle cut and mass flow rate of the fluid on the shell side on heat transfer and pressure drop by using the ANSYS Fluent, which is a type of computational fluid dynamics (CFD) software. For this aim, oil and water are used as working fluids in the shell and tubes of the STHE, respectively. Four different mass flow rates (0.6 kg/s, 0.8 kg/s, 1.0 kg/s, and 1.2 kg/s) are used for the fluid in the shell. In the analysis, three different STHEs with baffle cuts of 20%, 30%, and 40% are compared. According to the results of the CFD analysis, baffle cut plays an important role in heat transfer and pressure drop. The highest heat transfer per pressure drop was achieved for the STHE with 40% baffle cut and the lowest was achieved for the STHE with 20% baffle cut.
AtıfScopus13WoS8OpenAlex11İncele - Kitap BölümüYalnız künye2021Fine–kinney-based occupational risk assessment using fuzzy best and worst method (f-bwm) and fuzzy mairca
Gul, Muhammet; Mete, Suleyman; Serin, Faruk; Celik, Erkan
The best-worst method (BWM) proposed by Rezaei (Omega 53:49–57, [1]) is an MCDM method used to achieve the weights of the criteria by making fewer pairwise comparisons and using more consistent decision matrices. In this chapter, instead of crisp numbers, triangular fuzzy numbers that reflect the uncertainty well in real-world problems are used in integration with the BWM method (Guo and Zhao in Knowl Based Syst 121:23–31, [2]) in determining factor weights. Using the fuzzy best and worst method (F-BWM), a model based on Fine–Kinney occupational health and safety risk assessment method was developed for the first time in the literature. Three parameters of Fine–Kinney method are weighted by the mathematical models of F-BWM. Then, the risks are prioritized by fuzzy multi-attribute ideal real comparative analysis (F-MAIRCA). A case study was conducted to demonstrate the feasibility of the approach, and besides this case study, a comparative study was also conducted to test the validity of the proposed approach. This approach led to the conclusion that Fine–Kinney’s method, BWM, MAIRCA, and triangular fuzzy sets make the risk decision-making process more dynamic, taking into account the benefits of these methods individually or in integration.
AtıfScopus11OpenAlex12İncele - MakaleYalnız künye2021Scopus SJRQ2Synthesis and in silico studies of Novel Ru(II) complexes of Schiff base derivatives of 3-[(4-amino-5-thioxo-1,2,4-triazole-3-yl)methyl]-2(3H)-benzoxazolone compounds as potent Glutathione S-transferase and Cholinesterases Inhibitor
Adiguzel, Ragip; Türkan, Fikret; Yildiko, Ümit; Aras, Abdülmelik; Evren, Enes; Onkol, Tijen
Novel Ru(II) complexes of Shiff base derivatives of 3-[(4-amino-5-thioxo-1,2,4-triazole-3-yl)methyl]-2(3H)-benzoxazolone were synthesized. The ligands (1a-e) were confirmed by IR, 1H NMR, and 13C NMR spectra (only 1b and 1c). Structures of the synthesized Ru(II) complexes (2a-e) were illuminated by elemental analysis, IR, 1H NMR, 13C NMR, and mass spectra. As the biological studies, the inhibitory potency of the ligands and the novel synthesized complexes were evaluated against the glutathione S-transferase (GST), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in vitro conditions. Ki values in the range of 26.87-47.63 µM for AChE, 23.51-42.81 µM for BChE, and 33.14-51.73 µM for GST, respectively. The free binding energy of most active inhibitors against AChE, BChE, and GST enzymes were detected as -10.183 kcal/mol, -9.111 kcal/mol, and -6.097 kcal/mol, respectively. All compounds docked were observed to bind in the active site of the enzymes with similar binding orientation and binding interactions with the surrounding amino acids.
AtıfScopus31OpenAlex34İncele - MakaleYalnız künye2021Scopus SJRQ2Characterization of Various Carbon-Based Polypropylene Nanocomposites
Kaya, Ozge; Buran, Dincer; Akkurt, Nevzat; Yapici, Kerim; Sarac, Mehmet Fahri
Pure and three types of carbon additives including graphite, graphene, and multi-walled carbon nanotube added into polypropylene (PP) composites as a vibration damping component and sound insulator material in the automotive sector were investigated by using vibrational damping, dynamic mechanical analysis (DMA), tensile, hardness and acoustic behavior tests. According to the obtained results, porosity and distribution of carbon in the polymer matrix are key parameters on the composite parameters causing its reduction of tensile strength and its brittle behavior. Moreover, it seems that 0.01 wt.% graphene and 1 wt.% graphite added PP composites show the highest impact damping properties and also increase the storage and loss modulus of the composite while decreasing the glass transition temperature. The loss factor obtained from DMA and vibration damping test indicated the damping capacity in the interphase of carbon added PP composites depends only on the load applied and not sensitivity upon the natural frequency of the composite system. Depending on the morphological differentiation, graphene added PP composites decrease the sound transmission loss while the 0.1 wt.% MWCNT added PP composites increase sound transmission loss which makes it an alternative vibration damping component.
AtıfScopus6WoS6İncele - MakaleYalnız künye2021Scopus SJRQ2Investigation of Tie Bars Axial Force Demands in Composite Plate Shear Walls—Concrete Filled
Polat, Erkan; Kenarangi, Hadi; Bruneau, Michel
Tie bars axial force demands due to concrete dilation and prying action were investigated through numerical studies. In the first part of this study, the Karagozian and Case Concrete model, which proved to provide reasonable in-plane flexural cyclic inelastic wall response while accounting for concrete dilation effect, was used to investigate the variation of confinement inside the infill concrete, the distribution of passive confining pressures at the steel–concrete interface, and the resulting tie bar axial force demands. Finite element analyses involving C-PSW/CF having different tie spacings, wall depths, and wall thicknesses were performed. In the second part of this study, the influence of plate local buckling on tie bar axial force demand was investigated and explained by prying action. A separate finite element study was performed to investigate the significance of prying action and equations were developed from free-body diagrams. The results showed the significance of the passive confining pressures due to concrete dilation, and prying action due to local plate buckling, on imparting axial forces in tie bars. Neither of these behavior are currently considered as design parameters for tie bars. The numerical analyses and results presented here are intended to provide useful insights and direction for the design and instrumentation of future C-PSW/CF experiments by the broader research community.
AtıfScopus9WoS8OpenAlex8İncele - Kitap BölümüYalnız künye2021Economic and social impacts of COVID-19 on European tourism
Kazar, Gorkemli; Kazar, Altug; Akpinar, Tuba
European tourism has been largely disrupted by the pandemic throughout 2020. In this study, the economic and social effects of COVID-19 on the tourism sector of European countries were examined. To understand the extent of the pandemic on European tourism, policies followed by countries, physical tourism flows of the accommodation sector, tourism employment, and turnover rates were considered. The study showed that the European tourism sector, especially after the second half of 2020, was hit socially and economically by the devastating effects of the pandemic. In addition, the study revealed the necessity for radical regulations within the sector in the post-pandemic period.
- MakaleYayıncıda açık erişim2021Scopus SJRQ2Investigation of antioxidant properties of chamomile consumed as herbal tea
Karaaslan Ayhan, Nagihan
Common chamomile is consumed as herbal tea due to its antioxidant properties and biological activities in daily life. In this study, antioxidant activities and total phenolic contents of white and yellow chamomiles were investigated in terms of extraction methods and solvent types. In all extraction methods used for extraction of both chamomiles, the best antioxidant activity and total phenolic results were obtained with water extracts. Also, the best yield was found with sonication-assisted stirring for both chamomile extracts obtained using three extraction solvents. DPPH and ABTS radical scavenging activities obtained by sonication-assisted stirring for water extracts were 10.886 ± 0.244 mg TEAC/g and 8.702 ± 0.567 mg TEAC/g for white chamomile, and 11.709 ± 0.693 mg TEAC/g and 11.139 ± 0.514 mg TEAC/g for yellow chamomile. The total phenolic contents were determined as 3.863 ± 0.325 mg GAE/g for white chamomile and 5.225 ± 0.417 mg GAE/g for yellow chamomile. Novelty impact statement: In this study, the antioxidant properties of white and yellow chamomile were examined in detail in terms of different extraction methods and solvent types. Sonication-assisted stirring and water were determined to be the best extraction method and solvent for both chamomiles. According to the results, it can be stated that chamomile has higher antioxidant properties than white chamomile under the best extraction conditions.
AtıfScopus9WoS9OpenAlex8İncele - MakaleYalnız künye2021Scopus SJRQ2Recovery of Cu(II) by Acorga M5640 After Leaching of Malachite Ore in Perchloric Acid Solutions
Demirkıran, Nizamettin; Tanaydın, Mehmet Kayra
Abstract: In the present study, the recovery of Cu2+ from the resulting actual leach solution after the leaching of malachite ore in perchloric acid solutions was examined by applying the solvent extraction method. The organic phase was prepared using Acorga M5640 and kerosene. The effects of the initial pH of solution, extractant concentration, Cu2+ concentration, temperature, and stirring speed on the extraction process were investigated. It was determined that the extraction yield increased with an increase in the extractant concentration, initial pH of aqueous solution, stirring speed, and temperature, and with a decrease in the concentration of Cu2+. To prevent or minimize Zn2+ transfer to the organic phase and to ensure maximum Cu2+ extraction from the aqueous phase, the optimal values for the initial pH of the aqueous phase, initial concentration of Cu2+, extractant concentration, temperature, and stirring speed were selected to be 1, 0.152 g/L, 4% (v/v), 25 °C, and 400 rpm, respectively. The stoichiometry and mechanism of the extraction process were determined applying the equilibrium slope method. The changes in the Gibbs free energy, enthalpy, and entropy were determined. The changes in these thermodynamic parameters were calculated to be − 3.87 kJ/mol, 64.67 kJ/mol, and 0.23 kJ/(mol K), respectively. Graphical Abstract: The extraction percentage of Cu2+ increases substantially when the initial pH of the leach solution increases from 0.1 to 1. The further increase in the initial pH above 1 does not create an increase in the extraction extent of Cu2+. When the initial pH of the leach solution is higher than 1, the amount of Zn2+ transferred from the aqueous phase to the organic phase increases significantly.[Figure not available: see fulltext.].
AtıfScopus7WoS5OpenAlex9İncele