Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(102)
- Güler, Ömer(69)
- Akkurt, Nevzat(68)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(49)
- Celik, Erkan(45)
- Zengin, Gokhan(40)
- Serdar, Osman(39)
- Kocabaş, Mehmet(37)
- Aslan, Naim(31)
- Baskonus, Haci Mehmet(31)
- Bulut, Hasan(31)
- Mete, Suleyman(31)
- Paksoy, Mehmet Yavuz(30)
- Kök, Mediha(27)
- Ince, Muharrem(26)
- Yildirim, Ozal(26)
- Özkul, İskender(26)
- Sulaiman, Tukur Abdulkadir(25)
- Topal, Murat(25)
- Guler, Omer(24)
- Serin, Faruk(23)
- Benzer, Fulya(22)
- Erten, Fusun(22)
- Alataş, Mevlüt(21)
- Güler, Seval Hale(21)
- Baykal, Duygu Sen(20)
- Taşgın, Yahya(20)
- Kutlu, Banu(19)
- Onat, Onur(19)
- Sahin, Kazim(19)
- Tanyol, Mehtap(19)
- Torğut, Gülben(19)
- Yildirim, Numan(19)
- Kahraman, Gökhan(18)
- Orhan, Cemal(18)
- Say, Yakup(18)
- Susam, Selim Orhun(18)
- Utku, Anıl(18)
Yayınlar
- 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.
AtıfScopus9WoS7OpenAlex9
İncele - MakaleAçık Erişim2021Scopus SJRQ3A novel macrofungus for the biosorption of hazardous dye and its reuse potential: Experimental design approach using response surface methodology
Ince, Olcay Kaplan; Alp, Hevidar; Ince, Muharrem; Onal, Ali
In the present study, a novel biosorbent, namely Agaricus campestris, was used for the removal of Methylene Blue (MB) from an aqueous medium. The biosorbent was characterized using fourier-transform infrared spectrometer spectra, scanning electron microscopy-energy dispersive X-ray, and thermogravimetric analysis. The influence of important process parameters including pH (4–7), temperature (25°C–35°C), contact time (15–25 min), and biosorbent amount (40–80 mg) on the uptake of MB solution were also optimized, which significantly affected the removal efficiency of MB. A central composite design (CCD) combined with response surface modeling (RSM) was carried out to maximize MB removal by A. campestris for the adsorption process. A regression model was derived using RSM to predict the responses and analysis of variance (ANOVA), and to check model adequacy lack of fit test was used. The A. campestris adsorption capacity was determined as 24.2 mg g–1. The ANOVA showed a high coefficient of determination (R2 = 0.9987). This study clearly revealed that RSM was one of the most effective and appropriate method for the optimization of operating conditions. The possibility of reusing A. campestris was also investigated and, as a result, it was found quite possible and showed high performance in the recovery of MB.
AtıfScopus2WoS1OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ1Influences of sample shape, voltage gradient, and electrode surface form on the exergoeconomic performance characteristics of ohmic thawing of frozen minced beef
Çokgezme, Ömer Faruk; Döner, Deniz; Çevik, Mutlu; Kemahlıoğlu, Ali Varsın; İçier, Filiz
In the present study, it was aimed to investigate the exergoeconomic performance of ohmic thawing (OT) system during the thawing of frozen minced meat (lean beef). The effects of the sample shape (X: 13 × 4 × 3 cm, Y: 13 × 6 × 2 cm, Z: cylinder with a height of 13 cm and diameter of 3.91 cm), electrode surface form (titanium foil with smooth surface, titanium electrode with needle-type surface and titanium electrode with pyramid-type surface), and voltage gradients (10, 13, and 16 V/cm) were investigated. Lower exergoeconomic values were obtained for the cylindrical shape compared to the rectangular prism. The lowest exergy efficiency value (12.45 ± 0.42), is was obtained for the cylindrical shape at 10 V/cm voltage gradient with titanium foil electrode. The needle-type surface electrodes had higher performance values than other electrodes. The exergoeconomic performance increased as the voltage gradient increased. The lowest unit exergy cost (72.40 ± 2.8) was obtained for rectangular prism shape at 16 V/cm with needle-type electrode. The comprehensive exergoeconomic evaluation in this study exhibited the energy utilization effectiveness and unit exergy cost of OT.
AtıfScopus32WoS28OpenAlex30İncele - MakaleAçık Erişim2021Scopus SJRQ3A MCDM Based on Goal Programming and GIS-Based Risk Assessment for the Evaluation of Educational Locations in Conflict Areas
Hallak, Jamil; Polat, Elifcan Göçmen
Conflict is recognized as a major barrier in socio-economic development. In conflict situations, most sectors such as health, food, shelter and education are adversely affected. The provision of education services to conflict-affected children saves them from becoming a lost generation and contributes to community building. Thus, we conducted this research to investigate the potential of a GIS (Geographic Information Systems) approach and risk assessment based multi-criteria decision making (MCDM) for the allocation of displaced dropped-out children to the most appropriate educational centres, taking into account multiple goals related to cost, distance, risk, etc. A two-stage approach was adopted, utilizing a risk assessment approach, and a location-allocation approach. The risk assessment approach was carried out using GIS and F-AHP (Fuzzy Analytic Hierarchy Process) to determine the risk value of each candidate educational centre in the conflict area. In the location-allocation stage, a mathematical model was developed to allocate all demands to the chosen centres. All presented methods were computationally conducted on real case data provided by direct beneficiaries and stakeholders in the 26 sub-districts in the Idleb governorate, Syria. The computational results demonstrate that the proposed approaches ensure practical and theoretical impacts.
AtıfScopus8WoS5OpenAlex7İncele - MakaleAçık Erişim2021Scopus SJRQ2Fabrication of porous-Ti6Al4V alloy by using hot pressing technique and Mg space holder for hard-tissue biomedical applications
Aslan, N.; Aksakal, B.; Findik, F.
Porous-Ti6Al4V (P-Ti6Al4V) alloys were produced using the hot pressing and spacer methods for hard tissue biomedical applications and in particular, the effects of porosity on the mechanical and morphological properties of the structures were investigated. P-Ti6Al4V structures having the homogeneously distributed porosities at 41.08, 52.37 and 64.10% were fabricated by adding 40, 50 and 60% spherical magnesium (Mg) powder with 350 μm particle sizes in average as spacers and evaporating magnesium via the atmosphere-controlled sintering. The obtained porous structures were characterized by SEM, XRD and EDS. Furthermore, the strength and elastic modulus were evaluated by performing compression tests. Elastic modulus and densities were found to be 40–171 MPa, 2–5 GPa and 1.59–2.61, respectively and these values have been shown to decrease with an increase in porosity. The achieved density and mechanical property values, in particular, elastic modulus are close to human bone and within acceptable ranges for with biomedical application purposes. In addition, it was also found out from the analysis of produced P-Ti6Al4V that macropores were responsible for mechanical anisotropy contributed to formation of homogeneous and inter-connected open pores. [Figure not available: see fulltext.]
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İncele - 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 - MakaleAçık Erişim2021Scopus SJRQ4Presence of Neospora caninum DNA of Wild Birds from Turkey; [Türkiye’deki Vahşi Kuşlarda Neospora caninum DNA’sının Varlığı]
Karakavuk, Muhammet; Can, Hüseyin; Aldemir, Duygu; Döndüren, Ömer; Karakavuk, Tuğba; Karakavuk, Emrah; Özdemir, Hüseyin Gökhan; Muz, Mustafa Necati; Gürüz, Adnan Yüksel; Döşkaya, Mert
Objective: Neospora caninum is a protozoon parasite that has a worldwide distribution and mainly causes abortion in cattle and current serological evidence shows that the disease may be also zoonotic. Wild birds play a role as a reservoir of the disease in nature. The study aimed to determine the prensence of N. caninum in wild birds. Methods: In this study, the presence of neosporosis in wild birds (n=55) including 22 different species found in the western side of Turkey, was investigated by polymerase chain reaction (PCR). In addition, PCR positive samples were confirmed by sequencing, BLAST, and phylogenetic analysis using MEGA7. Results: Obtained results showed that the presence of N. caninum DNA was 5.45% (3/55) in brain-heart homogenates wild birds. The bird species which were found positive for N. caninum were little owl (Athene noctua), common buzzard (Buteo buteo), and little tern (Sternula albifrons). According to phylogenetic analysis and BLAST, all samples were compatible with reference N. caninum isolates. Conclusion: To the best of authors’ knowledge, this is the first study detecting N. caninum in little tern. In future studies, it may be interesting to investigate the prevalence of N. caninum in other wild animals to elucidate the transmission properties.
AtıfScopus3OpenAlex3
İncele - 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 - MakaleAçık Erişim2021Scopus SJRQ3Preliminary investigation on chemical composition and bioactivity of differently obtained extracts from Symphytum aintabicum Hub.- Mor. &Wickens
Zengin, Gokhan; Sinan, Kouadio Ibrahim; Ak, Gunes; Angeloni, Simone; Maggi, Filippo; Caprioli, Giovanni; Kaplan, Alevcan; Çakılcıoğlu, Uğur; Akan, Hasan; Jugreet, Sharmeen
Symphytum species, commonly known as comfrey, hold a long history of folk medicinal uses for healing wounds, bone fractures and other pain resulting from inflammation. However, many species belonging to this genus have not yet been scientifically investigated and hence investigation in this regard is warranted. In the present research, S. aintabicum extracts prepared by different extraction techniques (homogenizer assisted extraction, infusion and maceration) were assayed for their chemosystematic attributes (total phenolic, flavonoid) as well as bioactive compound contents, antioxidant and enzyme inhibition potentials. For instance, the extracts were found to possess phenolic and flavonoid levels ranging from 35.50 to 112.25 mg GAE/g and 2.54–25.12 mg RE/g, respectively. In general, the extracts displayed significant antioxidant activity. However, methanolic and infusion extracts were observed as the most potent radical scavengers and reducing agents, most likely related to their phenolic content. The extracts also showed metal chelating power and total antioxidant capacity in phosphomolybdenum assay. Moreover, while all extracts showed inhibition on amylase, only the methanolic extracts acted as inhibitors of cholinesterases and tyrosinase, most probably due to their relatively higher flavonoid content. The findings also indicated that the extraction method as well as the solvent type used to more or less affect the yield of the bioactive compounds and extracts’ bioactivity reported herein. Hence, as a first report highlighting the in vitro pharmacological properties of S. aintabicum, promising results were revealed from the quantitative chemosystematic analysis of bioactive components present and as sources of antioxidants and enzyme inhibitors against key human illnesses, thus providing scope for potential applications in phytomedicine development.
AtıfScopus15OpenAlex14İncele - 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 - MakaleAçık Erişim2021Scopus SJRQ4Interpolation Of Surfaces With Asymptotic Curves In Euclidean 3-Space
Altın, Mustafa; Üna, İnan; Mofarreh, Fatemah
In this paper, we investigate the interpolation of surfaces which are obtained from an isoasymptotic curve in 3D-Euclidean space. We prove that there exists a unique C0-Hermite surface interpolation related to an isoasymptotic curve under some special conditions on the marching scale functions. Finally, we present some examples and plot their graphs.
- BildiriAçık Erişim2021Deep Neural Network Trained on Surface ECG Improves Diagnostic Accuracy of Prior Myocardial Infarction over Q Wave Analysis
Yildirim, Ozal; Baloglu, Ulas B; Talo, Muhammed; Ganesan, Prasanth; Tung, Jagteshwar S; Kang, Guson; Tooley, James; Alhusseini, Mahmood I.; Baykaner, Tina; Wang, Paul J.
Clinical screening of myocardial infarction is important for preventative treatment and risk stratification in cardiology practice, however current detection by electrocardiogram Q-wave analysis provides only modest accuracy for assessing prior cardiac events. We set out to evaluate the ability of a deep neural network trained on the electrocardiogram to identify patients with clinical history of myocardial infarction. We assessed 608 patients at two academic centers with adjudicated history of myocardial infarction. Surface electrocardiograms were used to train a neural network-based model that classifies patients with and without a history of infarction. Endpoints were assessed by clinical record review and accuracy of the model was compared against the manual assessment of pathologic Q waves. The neural network outperformed the accuracy of pathologic Q waves (62%). In training, the model accuracy converged to >98%. Validation was performed by cross-validation (k=5) with validation accuracy 71 ± 5%. Receiver-operator characteristics analysis resulted in a c-statistic of 0.730. Deep learning of a 12-lead ECG can identify features of prior myocardial injury more accurately than clinical Q-wave analysis and may serve as a valuable clinical screening tool.
AtıfScopus3OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ2Protective Effect of Lutein/Zeaxanthin Isomers in Traumatic Brain Injury in Mice
Gunal, Mehmet Yalcin; Sakul, Ayse Arzu; Caglayan, Ahmet Burak; Erten, Fusun; Kursun, Oznur Ece Durmaz; Kilic, Ertugrul; Sahin, Kazim
Previous studies revealed that oxidative stress and inflammation are the main contributors to secondary injury after traumatic brain injury (TBI). In an earlier study, we reported that lutein/zeaxanthin isomers (L/Zi) exert antioxidative and anti-inflammatory effects by activating the nuclear factor-kappa B (NF-κB) and nuclear factor-erythroid 2-related factor 2 (Nrf2) pathways. However, its precise role and underlying mechanisms were largely unknown after TBI. This study was conducted to investigate the potential mechanism of L/Zi isomers in a TBI model induced by a cold injury model in mice. To investigate the effects of L/Zi, male C57BL/6j mice-induced brain injury using the cold trauma model was allocated into two groups (n = 7): (i) TBI + vehicle group and (ii) TBI + L/Zi group (20 mg/kg BW). Brain samples were collected 24 h later for analyses. L/Zi given immediately after the injury decreased infarct volume and blood–brain barrier (BBB) permeability; L/Zi treatment also significantly reduced proinflammatory cytokines, including interleukin1 beta (IL-1β), interleukin 6 (IL-6), and NF-κB levels and increased growth-associated protein 43 (GAP-43), neural cell adhesion molecule (NCAM), brain-derived neurotrophic factor (BDNF), and Nrf2 levels compared with vehicle control. These data suggest that L/Zi improves mitochondrial function in TBI models, possibly decreasing inflammation and activating the Nrf2 pathway.
AtıfScopus39OpenAlex40İncele - 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 - MakaleYalnız künye2021Scopus SJRQ4Reflection of eating awareness and life engagement of university students on the coronavirus (COVID-19) pandemic
Önen, Cihan; Sandikçi, Muhammed Bahadır
Study Objectives: With the restrictions in the pandemic process and the distance education process, changes have occurred in the diet of students. In such periods, which affect human life in a significant way in terms of public health, nutrition must be managed well. The study was conducted to evaluate the eating awareness of university students during the COVID-19 pandemic period and to examine its relationship with their engagement in life. Methods: The population of the cross-sectional study consists of the students of Munzur University. As a precaution regarding the COVID-19 pandemic, the participants were reached on the internet. Results: Eating awareness was statistically higher in men, married people, those with normal weight, and older students. While the life engagement among university students was high, the mean scores of eating awareness and its sub-components were moderate. Life engagement was significantly higher in sports science students than students in other academic units. There was a weak but significant relationship between eating awareness and engagement in life. Conclusion: Eating awareness of university students during the pandemic is at a moderate level. Students with high eating awareness are attached to life more. The highest life engagement among academic units is among sports science students. There is a need for public health initiatives to increase the awareness of eating among the students, against COVID-19 and possible future pandemics.
AtıfScopus3WoS2OpenAlex3İncele - MakaleYalnız künye2021Scopus SJRQ2Effect of the Mixing Structure Parameters of a Self-reflux Burner on Combustion Characteristics and NOx Emission
Xu, Qian; Shen, Meng; Shi, Kejian; Liu, Zhihui; Akkurt, Nevzat; Xiong, Yaxuan; Liu, Lin; Feng, Junxiao; Wang, Jiulong
To solve the problem of low efficiency of NOx emission reduction in self-reflux burners, this study is based on the concept of coordinated control of self-reflux burner structural and thermal parameters. After completing the structural design and optimization of thermal parameters, we continue to adjust the two key structural parameters: the nozzle axis distance and the length of the cylindrical section, to minimize NOx emissions. These are the two parameters that chiefly affect the mixing of flue gas and fuel gas. The results show that increasing nozzle axis distance can delay the mixing of gas and air and create a more uniform oxygen concentration field for the combustion process. The maximum combustion temperature is reduced from 1973.65 K to 1935.88 K and the volume fraction of NOx in the flue gas is reduced from 188.08×10−6 to 143.47×10−6. However, compared with the nozzle axis distance, the length of the cylindrical section of the burner has little effect on the mixing of the flow field. Under different cylindrical section lengths, the maximum combustion temperature does not change more than 3 K, and the volume fraction of NOx in the flue gas changes within 5×10−6.
AtıfScopus3OpenAlex2İncele