Yazarlar
- Tanyol, Mehtap(22)
- Yildirim, Numan(17)
- Karataş, Mehmet(14)
- Erguven, Gokhan Onder(13)
- Topal, Murat(13)
- Ince, Muharrem(12)
- Yildirim, Nuran Cikcikoglu(10)
- Kismet, Yilmaz(9)
- Öbek, Erdal(8)
- Arslan Topal, E. Işıl(7)
- Etli, Serkan(7)
- Goksu, Ali(7)
- Gul, Muhammet(7)
- Gülmez, Nihan(7)
- Ogedey, Aysenur(7)
- Uysal, Turan(7)
- Yonten, Vahap(7)
- Gürler, Nedim(6)
- Kaya, Sema Kayapinar(6)
- Sabanci, Serdal(6)
- Serdar, Osman(6)
- Yön, Merve Şahin(6)
- Alp, Hevidar(5)
- Aydoğmuş, Ercan(5)
- Benli, Ahmet(5)
- Cemalgil, Selim(5)
- Erdemoğlu, Murat(5)
- Erust, Ceren(5)
- Ince, Olcay Kaplan(5)
- Oguz, Ensar(5)
- Torğut, Gülben(5)
- Yilmaz, Mehmet(5)
- Yucesan, Melih(5)
- Celik, Erkan(4)
- Demir, Veysel(4)
- Dener, Murat(4)
- Doğan, Akar(4)
- Fırat, Tülay(4)
- Pekdemir, Mustafa Ersin(4)
- Tanaydin, Mehmet Kayra(4)
Yayınlar
- MakaleAçık Erişim2022Characterization and dye adsorption effectiveness of activated carbon synthesized from olive pomace
Deniz, Fatma; Başgöz, Öyküm; Güler, Ömer; Mazmanci, Mehmet Ali
Studies, about products obtained from agricultural wastes, have increased within the scope of zero waste studies. The olive pomace is produced as a result of olive oil production. In the present study, activated carbon was synthesized using the olive pomace taken from the olive pomace processing plant operating with a three-phase process. The synthesized activated carbon characterization was performed using Scanning Electron Microscope (SEM), Fourier-Transform Infrared Spectroscopy (FT-IR), Brunauer – Emmett – Teller (BET), and X-Ray Crystallography (XRD) devices. Olive pomace activated carbon (OPAC) was used for the adsorption of dye from an aqueous solution. The adsorption efficiency of the OPAC was investigated. The initial pH value of dye solution (6–9), the amount of activated carbon (0.5 and 1.0 g/L), and initial dye concentration (600–1200 mg/L) were optimized. Also, adsorption kinetic and isotherm calculations were evaluated. The optimum parameters were found as the original pH value (pH=8) of dye solutions, OPAC amount of 1.0 g/L and the initial concentration of 1000 mg/L. The Langmuir isotherm model and the pseudo-second-order kinetic model were found as the most suitable models. It can be said that the synthesized material can be used at dye removing from wastewater.
AtıfScopus6OpenAlex3
İncele - MakaleAçık Erişim2022Scopus SJRQ3Decolorization of Remazol Brilliant Violet 5R and Brilliant Green dyes by Hypnum cupressiforme using response surface methodology-central composite design methodology: toxicity assessment studies by Daphnia magna
Korkmaz, Volkan; Erguven, Gokhan Onder; Tanyol, Mehtap; Alatas, Mevlut; Yildirim, Numan
This study is the first report that aims to optimize the removal of Remazol Brilliant Violet 5R (RBV 5R) and Brilliant Green (BG) from synthetic solutions using Hypnum cupressiforme samples from Abant Mountains of Bolu (Turkey) as biosorbent and to conduct toxicity evaluation studies of treated wastewater using Daphnia magna. Optimization was performed using central composite design under response surface methodology with the operational factors of dye concentration, H. cupressiforme dose, and process time. The optimal conditions for dye concentration, H. cupres-siforme dose, and process time obtained by the numerical analysis were 19.02 mg/L, 0.18 g/50 mL and 110.59 min for RBV 5R, while these values were 18.57 mg/L, 0.18 g/50 mL and 99.45 min for BG, respectively. At the optimum values, maximum RBV 5R and BG removal were achieved as 99.39% and 99.22%, respectively. The D. magna mortality rates showed that treatment with adsorption were sufficient to remove the complete toxicity of dyes especially for RBV 5R.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleAçık Erişim2022Scopus SJRQ1Evaluation of the mechanical properties and durability of self-compacting alkali-activated mortar made from boron waste and granulated blast furnace slag
Yön, Merve Şahin; Karataş, Mehmet
The production of high-strength alkali-activated mortar and concrete by using waste materials instead of cement in order to reduce the amount of carbon dioxide released to nature in cement production is an important study that attracts the attention of researchers. In this study, self-compacting alkali-activated mortar samples were produced using boron waste (BW) and granulated blast furnace slag (GBFS). Prismatic samples of 40 × 40 × 160 mm and cubes of 50 × 50 × 50 mm were produced, in which 0%, 5%, 10%, 15%, 20%, 25% of BW were used. To achieve self-compacting alkali-activated mortar (SCAAM) slump-flow test method was conducted by per The European Federation of Specialist Construction Chemicals and Concrete Systems (EFNARC) guidelines. The samples prepared using Na2SiO3 (NS)/NaOH (NH) = 3.0 were exposed to oven curing at 60 °C and 100 °C for 3 days. The flexural and compressive strength (CS) values of 3, 28 and 90 days were obtained for the samples whose curing period was completed. According to the mechanical strength results, influence of capillary water absorption, porosity, water absorption and density and freeze-thaw from durability tests were carried out. After experimental tests, Scanning Electron Microscope (SEM) and Energy-dispersive X-ray Spectroscopy (EDS) images were utilized to determine microstructures of the samples. As a result of the study, it was determined that the highest strengths were obtained at the curing temperature of 60 °C. Also, it was seen that mechanical strengths and durability decreased with the increase in the BW ratio in the mixtures.
AtıfScopus31WoS28OpenAlex33İncele - MakaleAçık Erişim2022Scopus SJRQ1Preliminary assessment of health risks associated with consumption of grapevines contaminated with mining effluents in Turkey: Persistent trace elements and critical raw materials
Topal, Murat; Arslan Topal, E.Işıl; Öbek, Erdal
In this study, some persistent trace elements and critical raw materials were investigated in grapevines contaminated with Pb–Zn mining effluents. The persistent trace elements under certain conditions remain without any change in form in the environment over long periods. The critical raw materials are the ones that have economic importance and have the risks associated with their supply. The health risks of persistent trace elements and critical raw materials in the leaves of grapevine that are consumed by humans were determined. The highest persistent trace elements concentrations followed the order of root > stem > leaf for Mn, Cu, Cd, Ni, and Cr while root > leaf > stem for Zn and leaf > root > stem for Pb. The maximum critical raw material concentrations for Co and V followed the order of root > stem > leaf. For Sb and La, these were leaf > root > stem and root > stem > leaf, respectively. The maximum critical raw materials concentrations for W was leaf > stem = root. The total maximum carcinogenic value was 0.146 for Cd while the total minimum carcinogenic value was 0.0054 for Pb. In this study, potential carcinogenic risk values in terms of ingestion of contaminated soil (Cr, Cd, and Ni) and dietary take of grapevine leaves (Ni, Cr, Cd, and Pb) are higher than acceptable levels (1 × 10−4 – 1 × 10−6). Maximum cancer risk on human health was determined as dietary intake of grapevine leaves. When hazard quotient for dietary (HQdie), hazard quotient for ingestion (HQing), and hazard quotient for inhalation (HQinh) values of critical raw materials were examined, the maximum values were observed for children. Also, the highest hazard quotient for dermal (HQder) value was determined for men. The hazard index and total hazard index values were >1 for critical raw materials. As a result, values >1 indicated potential non-carcinogenic human health risk associated with the consumption of grapevines contaminated with mining effluents. Actual region-specific exposure estimates for consumption of grapevines, however, were not evaluated. Integr Environ Assess Manag 2022;18:517–527.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleAçık Erişim2022Scopus SJRQ3Economic analysis of rare earth element processing methods for Mountain Pass ore
Uysal, T.
The increasing demand for rare earth elements (REE) in highly strategic sectors such as hybrid electric vehicles, renewable energy, communication technologies, and the defense industry has made REE production methods important. In recent years, studies on REE have increased rapidly; however there are many studies on REE, there are not enough studies in the literature on the economics of the beneficiation process. RE ores are generally leached after beneficiation by gravity, magnetic and flotation methods. In this study, direct leaching, attrition scrubbing and leaching, and flotation and leaching methods are evaluated economically based on the data for the Mountain Pass (MP) facility. According to the sensitivity analysis performed as a function of capital cost (CAPEX), operating cost (OPEX), and rare earths oxides (REO) recovery, REO recovery has the biggest effect on the process economies. Although the flotation method entails additional investment and operating costs, transportation and operating costs are significantly reduced result of the higher grade and recovery. The flotation method is more profitable, with larger NPV and IRR values and a shorter payback period.
AtıfScopus8WoS8OpenAlex10İncele - MakaleAçık Erişim2022Scopus SJRQ1Medical waste management during coronavirus disease 2019 pandemic at the city level
Polat, E.G.
Coronavirus disease 2019 brings about the economic damage and loss of life. Thus, demand of personal protective equipment continues to increase, consequently an increase in infectious equipment pollution. Most of these wastes threaten the environment and increase the spread of diseases. This paper provides a research hypothesis whether effective medical waste management would prevent the possible impacts of coronavirus disease 2019-related waste issues on environment at the city level. To confirm this hypothesis, installation of waste treatment centre is addressed. Then, by incorporating uncertain waste generation amounts utilizing Jimenez method, a pickup routing is addressed to decide the pickup routes between the waste treatment centre and residential area. This study is first to assign the optimistic, realistic and pessimistic scenarios of the uncertain waste generation using time series analysis method and waste generation formulation. Also, L-type matrix is used to define, assess and prioritize the environmental and operational risks on waste generation formulation and to provide risk reaction strategies. Practicality of these approaches is illustrated in the case of Turkey. The computational results reveal the effectiveness of the integrated method, which ensures practical and theoretical insights controlling the waste generation to prevent virus propagation for health authorities.
AtıfScopus15WoS13OpenAlex19İncele - MakaleYalnız künye2022Scopus SJRQ3The Effect of Using Waste Tire as a Fine Aggregate on Mechanical Properties of Fly Ash-Substituted Self-Compacting Concrete
Cemalgil, Selim
Wasted tyres are commonly used in civil engineering applications for a variety of purposes, including as concrete ingredients. Wasted tires that are mechanically sheared into shreds ranging in size from 25 to 300 mm and intended for use in concrete are called " Waste Shreded Tyre Aggregate" to make a contribution to sustainable waste management. Currently, at this point, the basic philosophy of this study is to investigate the effects of Waste Tire Aggregate (WTA) on the mechanical and durability properties of Self Compacting Concrete (SCC) to provide a contribution to reusing waste tires in the construction industry. WTAs with 5, 10, and 15% volume ratios are substituted for fine aggregate in SCC production. In addition, 15% mixtures with a binder quantity of 550 kg/m3, including 20 and 30% fly ash (FA) were substituted and prepared to be compared with the control concrete. To measure the rheological properties of SCCs, slump flow, V-funnel and L-box tests were performed. Then, the produced concrete samples of different sizes were cured under laboratory conditions for 28 days and then subjected to hardened concrete tests on the 28th, 56th and 90th days. The hardened concrete tests were composed of axial compressive strength, flexural strength, splitting tensile, diagonal tensile, abrasion resistance, modulus of elasticity. Finally, a durability test was performed as chlorine penetration depth. The test results show that WTA positively affects the properties of fresh and hardened SCC. Only, the increase in the substitution rate of WTA in concrete mixtures decreased the hardened state strength of the SCC. However, the addition of WTA to up to 15% of the total fine aggregate volume indicates that it is possible to apply recycled WTA to SCC and successfully satisfy both fresh and hardened SCC specifications.
AtıfScopus4WoS5OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ3Adsorptive removal of nickel ions from wastewater by synthesized a novel biocomposite material and process optimization by response surface methodology
Ince, Muharrem; Ince, Olcay Kaplan; Alp, Hevidar
In the present study, a fixed-bed column study was performed using a novel biocomposite mate-rial, Amanita vaginata immobilized on Amberlite XAD-4 resin, to find out the adsorption behavior of nickel (Ni2+) ions from industrial wastewater. The influence of some important operating conditions including pH (3–7), biocomposite material amount (150–250 mg (XAD-4:Amanita vaginata, 5:1)) influent flow rate (4–8 mL min–1) besides Ni2+ ions initial concentration (20–40 mg L–1) on the uptake of Ni2+ solution were also optimized using a synthetic water solution. A central composite design combined with response surface methodology was utilized to maximize Ni2+ ions removal using A. vaginata immobilized on Amberlite XAD-4 resin as a biocomposite material in a column biosorption process. A mathematical model was derived from the central composite design approach for predicting responses and analysis of variance. Also, for checking model adequacy a lack of fit test was carried out. It was determined that the checked and proposed quadratic model was derived from the experimental design data. The biocomposite material adsorption capacity was calculated as 6.28 mg g–1. A high coefficient of determination (R2 = 0.9887) was presented by analysis of variance. Results confirmed that the amount of adsorbed Ni2+ amount did not change with the increase of the flow rate ratio and dose when the initial concentration of Ni2+ ions increased. The maximum adsorp-tion capacity of biocomposite material was achieved at 6.9 pH, 150.1 mg of biocomposite material amount, 7.8 mL min–1 of solution flow rate, and 39.7 mg L–1 of Ni2+ ions initial concentration. Finally, the developed method was applied to industrial wastewater to determine Ni2+ ions concentrations.
AtıfScopus4WoS4OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ3The use of Phanerochaete chrysosporium as an alternative bioremedia-tion tool of heavy metal, chemical oxygen demand and phosphate from landfill leachate
Yildirim, Numan; Kardas, Elif; Ince, Muharrem
In this study, in order to investigate the bioremediation efficiency of Phanerochaete chrysosporium, chemical oxygen demand (COD) reduction, total phosphate levels and heavy metal (Fe2+, Mn2+, Zn2+ and Cu2+) removal were determined in five different experimental groups (control, X, Y, Z, and T) under static culture conditions containing leachate at different incubation periods (5, 10, and 20 d). At the end of the 20th day of incubation, 84% Mn2+ and Zn2+ removal was achieved in X application group. In the same application group, 90.88% COD reduction was also obtained. The lowest total phosphate value was determined as 2.63 g L–1 in T group compared with control group (5.0 g L–1). Similar improvements have been identified in other application groups in terms of metal removal, total phosphate levels and COD reduction. As a result, the findings obtained from our study show that white rot fungus P. chrysosporium can be used as an alternative biological resource in the studies for improving landfill leachate in terms of metal removal efficacy, COD and total phosphate level reduction capacity.
AtıfScopus3WoS1OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ2Linear programming with fuzzy parameters for inventory routing problem in effective management of personal protective equipment: a case study of corona virus disease 2019
Göçmen, Elifcan
Coronavirus disease 2019 (COVID-19) brings about severe disruptions for human living, economics, and environmental balance. This pandemic has boosted the demand for personal protective equipment (PPE) and thus, medical wastes. Thus, a research hypothesis is stated whether it would be possible to provide more efficient distribution and inventory planning to optimize the PPE availability in a fuzzy environment. To confirm the hypothesis, in addition to addressing a scientific novelty considering integration of linear programming with fuzzy parameters, named as the Jimenez’s method and clustering heuristic methods, the practicality of these approaches is provided on a real case study and generated instances from Turkey. The computational results reveal that clustering the 32% of the hospitals ensures optimum total cost and solution time while feasibility degree changes between 0, 4, and 1 values of the Jimenez are not more effective on the results. Improved cost results reveal the economic importance of the healthcare supply chain management and optimal PPE distribution and inventory planning can break down the disease propagation and reduce the detrimental impacts on human life. The proposed approach, for the first time, ensures practical and theoretical insights of distribution and storage decisions across disciplines, namely, engineering and health-care organization authorities.
AtıfScopus19WoS12OpenAlex19İncele - Kitap BölümüYalnız künye2022A Multi-attribute Decision-Making to Sustainable Construction Material Selection: A Bayesian BWM-SAW Hybrid Model
Alkan, Ramazan; Yucesan, Melih; Gul, Muhammet; Rezaei, J; Brunelli, M; Mohammadi, M
The increase in urbanization and developments in the production industry has led to rapid progress in the construction sector. Many new strategies are developed in the industry to reduce costs and improve building quality. In recent years, the necessity of sustainable construction practices comes to the fore to renew the building stock damaged as a result of natural disasters and reduce the cost concerns that arise in this situation to a reasonable level. Due to limited resources and environmental concerns, researchers and practitioners have begun to develop sustainable building materials. The problem of selecting these materials when constructing a new building is vital. In particular, depending on the sector's rapid growth in Turkey, it is becoming more and more important to select the best sustainable construction material. Therefore, this paper proposes a model to evaluate the most appropriate sustainable construction material via two multi-attribute decision-making (MADM) methods called “Bayesian Best-Worst Method (BWM) and Simple Additive Weighting (SAW)”. Initially, the criteria derived from existing literature were evaluated with the aid of construction sector-based respondents and extra information about the interrelationship between the criteria were determined by credal ranking in Bayesian BWM. Then, via SAW, the most appropriate material was selected among a set of alternatives. Two cases regarding sustainable insulating material selection are considered for the demonstration of the proposed MADM model.
AtıfScopus15WoS14OpenAlex13İncele - MakaleAçık Erişim2022Scopus SJRQ2Health, safety, and environmental failure evaluation by hybridizing fuzzy multi-attribute decision-making methods for maritime scrubber systems
Başhan, Veysi; Yucesan, Melih; Demirel, Hakan; Gul, Muhammet
Many shipping companies have started using scrubbers in their fleet to eliminate sulfur emissions from ships, per IMO (International Maritime Organization) rules. Before and during the scrubbers’ selection, the scrubbers’ operational failures have also started to appear and cause serious concerns. In this study, classified scrubber types are explained and open type, closed type, and hybrid scrubber systems are evaluated. To contribute to this gap in the literature, scrubber failures were identified, five experts with different perspectives were consulted, and the most common and critical malfunctions were evaluated with the fuzzy best–worst method (F-BWM) and fuzzy technique for order preference by similarity to an ideal solution (F-TOPSIS). F-BWM was used to determine the importance weights of the risk parameters used in evaluating failures since it provides fewer comparisons among pairwise comparison–based decision-making methods and a more consistent judgment in the evaluation. F-TOPSIS, on the other hand, was used to determine the final priority scores of the scrubber failures, taking into account the risk parameter weights obtained in the first stage. It has been preferred due to its easy to useness and based on its closeness to the ideal solution and applicability to risk and failure analysis problems. Considering all different systems in general, important issues such as collection efficiency, sulfur emission problem, abrasion, leakages, pump failures, heat exchanger failures, air fan sealing failures, sensors and failures in monitoring the whole system have been investigated. Results show that too high axial velocity for separator and flooded separator, too high solids concentration in recirculation liquid (SF2), piping leakages (SF5), poor quality or inappropriate consumables and chemicals (SF11), and feed circulation pump problems (SF6) are found to be the most important problems among thirteen failures.
AtıfScopus23OpenAlex23İncele - MakaleAçık Erişim2022Scopus SJRQ1Chitosan-graft-poly(N‑tert‑butylacrylamide) Copolymer: Synthesis, Characterization and Optimization of Tetracycline Removal Using RSM
Tanyol, Mehtap; Torğut, Gülben
In the present study, a graft copolymer was synthesized in accordance with the free radical method using N-tertiary butylacrylamide monomer on chitosan, which is an environmentally friendly polymer. The chemical structure and surface morphology of the newly synthesized graft copolymer were determined by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. Moreover, the thermal behavior was analyzed by thermogravimetric analysis. The chitosan-graft-poly(N‑tert‑butylacrylamide) graft copolymer was used as an adsorbent for the rapid removal of tetracycline from aqueous solutions in order to investigate its applicability. Response surface methodology (RSM) was employed for the optimization of the study conditions, namely adsorbent dosage (0.01–0.04 g 100 mL−1), reaction time (10–90 min) and initial tetracycline concentration (10–100 mg 100 mL−1). The effects of these conditions on tetracycline uptake capacity were examined and the results were statistically analyzed. The RSM results showed that the maximum tetracycline uptake capacity of 104.81 mg g−1 was achieved under the following conditions: adsorbent dose of 0.03 mg 100 mL−1, reaction time of 51.12 min and initial tetracycline concentration of 97.99 mg L−1. ANOVA based on central composite design combined with RSM showed a good agreement between the experimental values and quadratic model estimates, thus resulting in a coefficient (R2) of 0.9118 for tetracycline uptake. The kinetics, isotherms, and thermodynamics of adsorption were examined, and results showed that equilibrium data fitted the Freundlich isotherm model, and the adsorption kinetics of tetracycline followed pseudo-second-order model. Thermodynamic parameters like the enthalpy − 10.39 kJ mol−1 (ΔH°), entropy 0.044 kJ mol−1 K−1 (ΔS°) and Gibbs free energy − 23.26 kJ mol−1 (ΔG°) were evaluated and also, ΔG° shows a negative values indicating that the adsorption process was exothermic and spontaneous. The findings demonstrated that the chitosan-graft-poly(N‑tert‑butylacrylamide) copolymer is an effective adsorbent for pharmaceutical wastewater treatment.
AtıfScopus11WoS12OpenAlex11İncele - MakaleAçık Erişim2022Scopus SJRQ1A green algae Cladophora fracta for accumulation of toxic/harmful pollutants causing environmental pollution in mine gallery waters
Topal, M.; Arslan Topal, E.I.; Öbek, E.
In the present study, the bioaccumulation of toxic/harmful pollutants (Fe, Pb, As, Cd, Cr, Ba, and Mn) by Cladophora fracta in mine gallery water was investigated. For this aim, the reactors planted with C. fracta were placed into mine gallery waters. Bioconcentration factor (BCF), metal pollution index (MPI), and accumulation capacity values were determined. According to the obtained results, the highest concentrations of Cr, Mn, Fe, Ba, Pb, Cd, and As were determined as 24.3 ± 1.2, 858 ± 27, 26,290 ± 87, 11.4 ± 0.6, 117.05 ± 5.8, 47.9 ± 1.4, and 2390.3 ± 11 mg/kg, respectively. BCF values were Fe > Pb > As > Cd > Cr > Ba > Mn. The MPI values of toxic/harmful pollutants according to days were determined as day 1 > 5 > 7 > 2 > 6 > 4 > 3, respectively. As a result, it was determined that C. fracta, which was placed in the mine gallery and exposed to the gallery waters, was effective in removing toxic/harmful pollutants. Therefore, C. fracta can be used as an alternative treatment material for the removal of toxic/harmful pollutants in mine gallery waters.
AtıfScopus4WoS3OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ1High-temperature and abrasion resistance of self-compacting mortars incorporating binary and ternary blends of silica fume and slag
Yön, Merve Şahin; Arslan, Furkan; Karatas, Mehmet; Benli, Ahmet
Researchers from all over the world have recently developed an interest in the utilization of waste materials in the concrete industry. Using silica fume (SF) and ground granulated blast furnace slag (S) to manufacture self-compacting mortars (SCMs) could be a step toward sustainable waste management and produce the unique fresh qualities needed for SCMs. This research evaluates the abrasion and high-temperature resistance of SF and S based SCMs. A total of 14 mixtures were designed by partially replacing SF and S with Portland cement (PC) including control, binary and ternary mixtures. Binary mixtures were obtained by replacing cement by SF and S at replacement rates of 5, 10, 15 and 20 % and 10, 20, 30 % by weight respectively. Ternary mixtures were determined at the rates of 5, 10, 15 and 20 % SF and 10 and 20 % S respectively. The flexural strength and compressive strength of SF and S based binary and ternary water curing SCMs samples were determined at the age of 7, 28 and 90 days at room conditions. SCMs specimens were exposed to high temperatures after 90-day water curing. Water absorption, apparent porosity, sorptivity and abrasion resistance of 28-day water cured SCMs samples was also determined. The fresh and rheological properties of SCMs was evaluated by conducting mini-slump flow and viscosity tests. Cost analysis of the SCMs were also performed. The experimental results exhibited that the flowability of SCMs mixes containing SF was reduced with the increasing rate of SF compared to control while the workability of S incorporated SCMs mixes increased with the increase of S in comparison to control mixtures. Late- age of compressive strength above 70 MPa was achieved for 20 % SF incorporated binary mixture and 15 %SF and 10 % S incorporated ternary mixture. The ternary mixture with 15 % SF and 10 % S also exhibited the best abrasion resistance and the lowest sorptivity. Overall, it can be concluded from the mechanical characteristics and abrasion resistance that ternary combination of S with SF content of especially above 10 % and can be used to manufacture self-compacting mortar with a smaller carbon footprint.
AtıfScopus60WoS56OpenAlex62İncele - MakaleYalnız künye2022Scopus SJRQ1Evaluation of an ohmic assisted vacuum evaporation process for orange juice pulp
Sabanci, Serdal; Icier, Filiz
An ohmic assisted vacuum evaporation (OAVE) processes was used to concentrate orange juice from 11.4% total soluble solid content (TSSC) to 42% TSSC by applying 13 V/cm constant voltage gradient at different temperatures. The evaporation temperatures were adjusted to 100 °C, 85 °C, 75 °C and 65 °C by setting absolute system pressures of 101.32 kPa, 58 kPa, 39 kPa and 25 kPa, respectively. The total time for the processes, including heating and evaporation, was 34, 40, 48, and 54 min for 100, 85, 75, and 65 °C, respectively. As the evaporation temperature increased, the applied energy required for phase change decreased while maximum current values increased from 0.6 A at 65 °C to 2.52 A at 100 °C. During any given run, the current value increased as the orange juice pulp heated up, but then decreased after it began to boil, leading to a reduction in the rate of heat generation. Increasing evaporation temperature has a positive effect on evaporation rates, energy efficiency, specific water removal ratio (SWRR), exergy efficiency, and Improvement Potential (IP) (p < 0.05). The reduced energy requirement with higher temperature is partially due to reduced work from the vacuum pump at the higher absolute pressure.
AtıfScopus19WoS11OpenAlex16İncele - MakaleYalnız künye2022Scopus SJRQ2Naphthol green B Removal using a Novel Hydrogel Composite: Thermodynamics, Isotherms, Kinetics and Optimization by RSM
Pıhtılı, Güzin; Tanyol, Mehtap; Birkan, Kubra
In this study, the efficiency of the Poly(4-vinylpyridine-co-acrylamide) doped with EuCl3 {(Poly(4-VP-co-AAM)/EuCl3)} hydrogel synthesized in the laboratory by free radical in-situ polymerization method in removing naphthol green B (NGB) from wastewater was investigated. The structural properties of the adsorbent have been described by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The dependence of NGB adsorption performance on varying such as the amount of adsorbent, initial NGB concentration and contact time were investigated in a batch system. To determine the interaction effects of the selected parameters on the adsorption process and to optimize the adsorption capacity of the process, the central composite design (CCD) in the response surface methodology (RSM) was used. Optimum conditions were found to be 110 mg/L NGB concentration, 0.05 g/100 mL Poly(4-VP-co-AAM)/EuCl3/EuCl3 dosage and 165.81 min contact time. The adsorption capacity and removal efficiency under these conditions were 206.46 mg/g and 92.50 %, respectively. Experimental equilibrium data were in better agreement with the Langmuir isotherm. The kinetic results indicated that the adsorption process can be defined by pseudo-second-order kinetic with internal diffusion as one of the rate-determining steps. The adsorption process was found to be exothermic and spontaneous. Experimental results showed that dye can be successfully removed from wastewaters using Poly(4-VP-co-AAM)/EuCl3 hydrogel as adsorbent.
AtıfScopus5WoS5OpenAlex6İncele - MakaleYalnız künye2022Scopus SJRQ2Performance evaluation of pectin extraction from grapefruit peel powder by ohmic heating
Goksu, Ali; Duran, Gülseven; Çilingir, Seda; Çevik, Mutlu; Sabanci, Serdal
This study is to investigate the performance properties during the extraction of pectin from grapefruit peel powder using ohmic heating. Pectin extraction was carried out under different voltage gradients (7–11 V/cm), different solid: liquid ratios (1:20–1:60), and different holding times (0–180 min) at constant pH and temperature (80°C). The voltage gradient and solid: liquid ratio affected the time to reach the target temperature. The highest energy efficiency value for all voltage gradients and solid: liquid ratios were obtained in the 0 min holding time, and the efficiency value, which changed between 89.47% and 56.02%, was negatively affected by the increase in the holding time. The exergy efficiency was lower than the energy efficiency and decreased due to the increasing holding time and decreasing voltage gradient. Also, the exergy efficiency was found to be between 73.69% and 18.09%. Determining the performance characteristics of the system will make a significant contribution to pilot and industrial-scale system/process applications for the future. Practical application: In this study, pectin was successfully obtained from grapefruit powder using an ohmic heating system. The operating conditions for the obtained pectin include constant pH (pH:1) and temperature (80°C) but various voltage gradients, solid: liquid ratios, and extraction times. It has been observed that voltage gradient and extraction time were effective on energy efficiency. When looking at exergy efficiency, voltage gradient, solid: liquid ratio, and extraction time were effective. It has been observed that the improvement potential (IP) value calculated for the system decreases depending on the increasing voltage gradient. The results obtained in this study are thought to be an important data source for literature, pilot, and industrial-scale production systems. It has been realized that ohmic heating, which is increasingly used, is an alternative technique for pectin production.
AtıfScopus13WoS12OpenAlex16İncele - MakaleAçık Erişim2022Scopus SJRQ1DEEP LEARNING BASED A COMPREHENSIVE ANALYSIS FOR WASTE PREDICTION
Utku, Anıl; Kaya, Sema Kayapinar
In its simplest definition, waste can be defined as any substance that is used, not needed and causes harm to the environment. Waste management covers control activities such as prevention of the formation of waste, reuse, separation according to its characteristics and type, storage, transportation, recycling and disposal. The main purpose of waste management is to leave a livable world to future generations, to create a sustainable environment, to protect natural resources, to save energy and costs, to reduce the rate of pollution and the amount of hazardous waste. In today's world where urbanization and industrialization rates are increasing, waste management is gaining importance. The aim of this study is to utilize waste data from Istanbul, Turkey's largest and fastest growing city, to estimate waste amount using a constructed Long Short-Term Memory (LSTM) based deep learning model. The developed LSTM-based model has been compared in practice with k-Nearest Neighbors (kNN), random forest (RF), Support Vector Machine (SVM), multi-layered perceptron (MLP) and Gated Recurrent Unit (GRU). As a result of the comparative and comprehensive analyzes, the experimental results showed that the developed LSTM-based deep learning method is more successful in the waste prediction problem than the other compared models.
AtıfScopus13OpenAlex13İncele - MakaleYalnız künye2022Scopus SJRQ2Characterization of the mechanical and thermal properties of rape short natural-fiber reinforced thermoplastic composites
Kısmet, Yılmaz; Dogan, Akar
In this study, the effects of filler amounts were studied on the mechanical and thermal properties of high-density polyethylene (HDPE), polystyrene (PS) and polyoxymethylene (POM) polymers reinforced with short rape fibers. HDPE-rape, POM-rape and PS-rape fiber composite materials were prepared with different fiber contents and their tensile, flexural, Izod impact and TGA/DTA properties were examined. When tensile and Izod impact properties were compared, it was observed that an increase in the amount of filling in HDPE-based composites did not cause any significant changes in these peoperties, while they were decreased for POM- and PS-based composites. On the contrary to tensile and impact strengths, when the three-point flexural properties were examined, it was observed that the strength values of all these materials increased with increasing the amount of fillers. However, a pronounced increase was observed in the three-point flexural strength of the HDPE-based composite materials. The flexural strength of 30 wt% rape-reinforced HDPE composite was found to be twice that of the pure HDPE. The results of TGA and DTA analyses revealed that the reinforcement element started to burn before the matrix material and therefore burning was delayed in these thermoplastics. As a result, the mechanical properties of HDPE composite materials improved with rape reinforcement. In this way, by using approximately 30 wt% natural filling material in a polymeric matrix, an environmentally friendly material, as well as, significant advantages in cost can be obtained. Graphic abstract: [Figure not available: see fulltext.].
AtıfScopus25WoS25OpenAlex33İncele
