Yazarlar
- Tanyol, Mehtap(22)
- Yildirim, Numan(17)
- Karataş, Mehmet(14)
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- Topal, Murat(13)
- Ince, Muharrem(12)
- Yildirim, Nuran Cikcikoglu(10)
- Kismet, Yilmaz(9)
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- Etli, Serkan(7)
- Goksu, Ali(7)
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- Gülmez, Nihan(7)
- Ogedey, Aysenur(7)
- Uysal, Turan(7)
- Yonten, Vahap(7)
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- Yön, Merve Şahin(6)
- Alp, Hevidar(5)
- Aydoğmuş, Ercan(5)
- Benli, Ahmet(5)
- Cemalgil, Selim(5)
- Erdemoğlu, Murat(5)
- Erust, Ceren(5)
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- Oguz, Ensar(5)
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- 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 Erişim2025Investigation of the Bioactivity Properties of TiZrCrNb0.3Ta0.07 Medium Entropy Alloy Produced from TNTZ Waste
Say, Yakup; Yayla, Nihal; Güler, Ömer; Güzel, Harun
High entropy alloys (HEAs) and medium entropy alloys (MEAs) have garnered significant attention as alternative materials in various fields due to their superior physical and chemical properties compared to conventional alloys. One of the most promising applications of this innovative material class is in biomaterials. In this study, a bio-medium entropy alloy (BioMEA), TiZrCrNb0.25Ta0.05, was successfully synthesized using non-toxic elements (Ti, Zr, Cr, Nb and Ta) through arc melting of TNTZ alloy waste. The produced BioMEA was comprehensively characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) to analyze its structural and chemical properties. Additionally, the in-vitro degradation, ion release, and bioactivity properties of the alloy were evaluated and compared with those of the conventional TNTZ alloy, with a focus on the effects of heat treatment. The results demonstrated that heat treatment did not cause significant changes in the microstructure of the TiZrCrNb0.25Ta0.05 alloy but led to the formation of intermetallic compounds such as Cr2Zr and Cr2Ta on the surface. Degradation tests revealed an unexpected mass gain across all sample groups after a four-week immersion period due to surface precipitation, surpassing the expected mass loss from degradation. Ion release analyses showed similar behavior between the TiZrCrNb0.25Ta0.05 and TNTZ alloys, with ion release levels in the ppb range, confirming that Ti was released at non-toxic levels. Bioactivity tests identified low lesvels of Ca-P-O deposition on all sample surfaces, with the highest bioactivity observed in the heat-treated TiZrCrNb0.25Ta0.05 sample. Overall, the findings suggest that the TiZrCrNb0.25Ta0.05 alloy has the potential to serve as an alternative biomaterial to the TNTZ alloy, with its bioactivity properties being further enhanced through heat treatment. Further studies are recommended to optimize its bioactivity and evaluate its in-vivo performance for biomedical applications.
- MakaleAçık Erişim2025Effects of Alternative Binder and Aggregate Use on the Compressive Strength of Concrete
Gülmez, Nihan; Pala, Mustafa
The use of industrial wastes in concrete production is of significant importance in reducing environmental impacts and lowering costs. In this study, concrete mixtures were designed by using olivine minerals as a substitute for Portland cement (PC), chromite powder as fine aggregate, and ferrochromium slag as coarse aggregate. The effects of different binder and aggregate ratios on the compressive strength of the concrete were examined after a 7-day curing period. Experimental results showed that mixtures with 5% olivine substitution achieved the highest compressive strength of 22.30 MPa, particularly in mixtures with a cement dosage of 500 kg/m³. This result indicates that the low water/cement ratio and the addition of olivine contribute to increased early-age strength. Furthermore, increasing the chromite powder content to 20% in mixtures with a water/cement ratio of 0.61 led to an 11.7% increase in compressive strength, demonstrating the positive impact of chromite powder on the mechanical performance of the concrete. These findings highlight that cement replacements and aggregate types can significantly affect the mechanical properties of concrete, emphasizing the need for careful selection of both material compositions.
- MakaleAçık Erişim2025Scopus SJRQ1Rejuvenation of Recycled Asphalt Binders with Bio-Oils from Waste Biomass Pyrolysis
Yalcin, Beyza Furtana; Yilmaz, Mehmet; Yalçin, Erkut; Altundogan, Hamdi Soner
This study evaluates the effects of using bio-oil obtained from waste biomass on the physical properties, rheology, fatigue, and rutting of recycled asphalt binder. In addition, the aim of this study is to provide benefits to the environment and the economy by reusing waste materials. The bio-oils produced were produced by the pyrolysis method. B70/100 pure bitumen was chosen as the reference binder for the rejuvenation of the selected RAP binder. To ensure its properties, five different rejuvenators (two commercial + three bio-based rejuvenators) were added to the aged bitumen obtained from recycled asphalt pavement (RAP) at different rates. The produced bio-oils were compared with commercial products. The first goal of the study is to produce rejuvenators from waste materials, and the second is to achieve similar or better results with commercial rejuvenators by producing rejuvenators from waste materials. When the test results are examined, it can be seen that the aged binder was rejuvenated to the desired hardness by adding rejuvenator to it. It is seen that the penetration value of the aged binder increased by the addition of rejuvenator, whereas the softening point and viscosity values decreased.
AtıfWoS1OpenAlex1
İncele - MakaleYalnız künye2025Scopus SJRQ2Impact of green innovation on environmental issues: Findings from BRICS-T countries based on spatial analysis
Han, Ayşegül; Pehlivan, Ceren; Konat, Gökhan; Koncak, Ahmet
This study examines the impact of green innovations on environmental sustainability in BRICS-T countries between 2008 and 2021. Using indicators such as renewable energy consumption, R&D investments, industrial design activities, and carbon emissions, the analysis employs both conventional and spatial panel estimation techniques. The findings reveal that investments in renewable energy play a crucial role in reducing carbon emissions and positively contribute to environmental sustainability. However, the effectiveness of environmental innovation policies and R&D expenditures in mitigating emissions remains limited, particularly in the short term. Additionally, industrial design activities are identified as a significant contributor to rising emissions, highlighting the need for a transition toward more sustainable industrial practices. The study also uncovers spatial dependencies among countries, demonstrating that carbon emissions in one nation can influence those in neighboring countries, emphasizing the necessity of regional cooperation and coordinated environmental policies. Based on these findings, the study provides policy recommendations to enhance the effectiveness of green innovations, stressing the importance of increasing investments in renewable energy, aligning R&D expenditures with environmentally sustainable technologies, and promoting sustainable industrial practices across BRICS-T countries.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleYalnız künye2025Scopus SJRQ2Green synthesis of environmentally friendly Ag/AgCl nanoparticles for use as solid phase extraction materials
Kurnaz Yetim, Nurdan; Hasanoğlu Özkan, Elvan; Aslan, Naim; Koç, Mümin Mehmet; Nartop, Dilek; Özcan, Cemile
Green synthesis is a prominent procedure used to easily and environmentally friendly fabricate nanostructures and nanoparticles (NPs), without complex instrumentation, intricate procedures, and harmful chemicals. This study investigated the green synthesis of silver NPs (AgNPs), with Aronia melanocarpa fruit extract as the reducing agent. Following synthesis optimization, AgNPs were characterized using a range of analytical techniques, including UV–Vis, XRD, SEM-EDX, BET, and TEM analyses. Based on the characterization results, an Ag/AgCl hybrid structure was formed. The Ag/AgCl NPs obtained were utilized as adsorbents to remove Cd(II) and Pb(II) heavy metals. The experimental factors that were optimized included pH (5.5), sample volume (5 mL), eluent type and concentration (2 M HNO3), adsorbent amount (5 mg), and extraction time (30 min). Under optimized conditions, the limits of detection were determined to be 9.6 and 4.8 µg/L for Pb(II) and Cd(II), respectively. These limits were established within a concentration range of 50–3,000 µg/L.
AtıfScopus3WoS3OpenAlex3
İncele - MakaleAçık Erişim2025Scopus SJRQ2Evaluation effect of physicochemical properties of deep eutectic solvents on phenolic compounds extraction yield from Kultik seed
Aydin, Çağlar Mert
The aim of this study is to achieve maximum phenolic component extraction efficiency by using deep eutectic solvent, and to gain higher extraction efficiency than that obtained using conventional solvent from fruit waste, namely Kultik seed (Cucumis melo L.). Six DES (deep eutectic solvent) combination were formed using zinc chloride, ethylene glycerol, lactic acid, choline chloride, sorbitol and glucose. The evaluated DES properties were viscosity, pH, %brix and refractometric index, and their effect on phenolic extraction. Overall, the forming components significantly influence DES properties, indicating importance of choosing proper components in DES formation to receive desired extraction result. There was a correlation between extraction yield and DES properties (brix%, pH and viscosity), showing adjusting these properties are crucial in yield of desired phenolic extraction yield, r > 0.5. Alcohol based DESs had lower viscosity, higher brix% and pH in the range of 3–5. Sugar based DESs had higher viscosity, lower brix% and pH other than the range of 3–5. The highest phenolic extraction efficiency was obtained in extraction using alcohol based DESs as solvent, while the extraction using sugar and carboxylic acid based DESs underperformed. Furthermore, the extractions using some DES types (zinc chloride: ethylene glycerol (149.5 mg GAE 100 g−1), choline chloride: ethylene glycerol (161.5 mg GAE 100 g−1)) achieved better phenolic yield than that obtained using conventional solvents (water (7,6 mg GAE 100 g−1), methanol (80.2 mg GAE 100 g−1), ethanol (138.7 mg GAE 100 g−1)). These results indicate that DESs, as a green solvent, provide excellent alternative to organic solvents for green chemistry, and have a great potential to use in industrial applications involving extraction of bioactive compounds from plant sources.
- MakaleAçık Erişim2025Scopus SJRQ3Optimization of rare earth elements recovery from Kızıldag (Karaman-Türkiye) shale ore using response surface methodology
Uysal, Turan; Ünal, Ceren Erust; Akça, Muhammet Esat; Sis, Hikmet; Erdemoğlu, Murat
In this study, the usability of bauxite-related shale ore, rich in Rare Earth Elements (REEs), to produce REEs, which have high added value and critical importance, was investigated. In this context, Kızıldag (Karaman-Türkiye) shale ore, was prepared for tests through size reduction and sampling processes. HCl leaching was performed at different acid concentrations, leaching times, leaching temperatures, and liquid/solid ratios to determine the optimum leaching conditions for the milled ore. The modeling and optimization parameters related to leaching recovery were investigated using the response surface method (RSM). The results were evaluated using analysis of variance, three-dimensional graphs were drawn, and the accuracy of the models was discussed. Accordingly, optimum values were found, and the REE leaching recovery corresponding to these optimum values was 49.13%. It was concluded that the optimization results were compatible with the experimental results, and the average error rate (6.35%) was low.
AtıfScopus3OpenAlex4İncele - MakaleAçık Erişim2025Scopus SJRQ2Farm-Raised Versus Wild Caught Fish: Which is Better?
Can, Erkan; Özçiçek, Esin; Erol, Nida Demirtaş; Austin, Brian
There has been much discussion about which is better, farmed (= aquaculture) or wild-caught fish (= capture-fisheries), with supporters and opponents of both approaches. On balance, aquaculture should be the better option because of the ability to control all aspects of production. The result is that farmed products are often cheaper than wild-caught equivalents. However, there are negative aspects to aquaculture, including habitat destruction, for example the removal of mangroves for the construction of shrimp farms, the effect of escapees on native fish populations, and the possible negative impact of pollution from organic material, pathogens and antimicrobial compounds. The use of wild-caught “trash” fish as a source of protein and oil for the diets of carnivorous fish species in aquaculture is unsustainable. In contrast with wild-caught fish, there is greater variability in supply because of overfishing, quotas imposed by governments, and the effects of adverse weather. Moreover, fishing in distant waters is expensive and hazardous. Certainly, the quality of the product is more difficult to control because the history of the catch is largely unknown. However, there are concerns about illegal fishing activities, and the capture of undersized specimens which impacts negatively on future stocking levels. For the forseeable future, there will be roles for both aquaculture and capture-fisheries to meet the increasing global demand for aquatic food.
AtıfScopus5WoS5OpenAlex5İncele - Kitap BölümüYalnız künye2025Scopus SJRQ4Examination of Recycled Papers Using an Intuitionistic Fuzzy Set-Based MCDM
Tuğrul, Feride
Multi-criteria decision making (MCDM) methods are used in combination with intuitionistic fuzzy sets offer very favorable results to decision makers. Intuitionistic fuzzy set-based MCDM methods defined in this direction were utilized in many application areas. In this study, recycled papers were examined separately according to Cyan, Magenta and Yellow colors. Paper samples, which passed through a total of 4 recycling stages, were evaluated according to their L, a, and b values. The decision making mechanism established in the study was observed that provides effective results in the fields such as paper quality, print quality, recycling, etc.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluating the high-temperature resistance of self-compacting mortar incorporating waste andesite powder as a mineral admixture
Karataş, Mehmet; Bozcan, Emre; Dener, Murat
Significant amounts of waste material are generated at various stages of andesite stone processing, including mining, cutting, and polishing. Despite this, limited research has been conducted on the potential use of waste andesite powder (WAP) as a mineral admixture. The impact of WAP on the high-temperature resistance of cement-based composites remains largely unexplored. This study aims to evaluate the benefits of incorporating WAP as a partial substitute for Portland cement. Self-compacting mortars (SCMs) with varying WAP replacement rates (5%–30%) were produced and subjected to temperatures of 300°C, 600°C, and 900°C. Additionally, ternary mixtures of WAP and silica fume were produced for comparative analysis. The results showed that SCMs containing up to 10% WAP exhibited higher 90-day compressive strength compared to the control sample. Furthermore, WAP inclusion improved high-temperature resistance, and the use of WAP at higher replacement rates was feasible when combined with mineral admixtures possessing high pozzolanic activity, such as silica fume.
AtıfScopus6WoS3OpenAlex4İncele - MakaleYalnız künye2025Scopus SJRQ2Hydrocolloid materials of fish bone-derived in edible films: can hydroxyapatite be an alternative approach to improving fillet shelf life?
Alak, Gonca; Kuzgun, Nermin Karaton
The valorization of industrial fish waste has gained significant scientific interest due to its integrated benefits such as waste management and resource recovery. The aim of this study is to evaluate the effectiveness of fish bones, which is one of the wastes of aquaculture processing and constitutes approximately 9–15% of the waste generated as a result of the process, as a preservative in the food industry within the scope of green chemistry applications, sustainability and green product targets. In line with this objective, in the first stage, hydroxyapatite (HAP) was obtained from the fish bones, in the second stage, chitosan (Ch)-based coating solutions were enriched with HAP at different levels (0.02, 0.04 and 0.08 g / L) and in the last stage, fillets were coated with this solution and fillet quality parameters were monitored by microbiological, chemical and sensory analyses at certain intervals (0, 3, 6, 9 and 12 days) during 12 days of storage (at + 4 °C). Based on the data obtained during the storage period, the shelf life of control (Chitosan, Ch). chitosan + low HAP (Ch + L-HAP) and chitosan + medium HAP (Ch + M-HAP) fillet groups increased by 50%, 26% and 20%, respectively, compared to chitosan + high HAP (Ch + H-HAP). In the findings obtained, it was determined that the high concentration application (Ch + H-HAP) had a negative effect on all the parameters studied in fillets, and when the data on the last day of storage, especially the microbiological results were taken into consideration, it was determined that the shelf life decreased by 20–50% on average compared to the other concentrations (Ch + L-HAP and Ch + M-HAP) and Ch group and caused serious negativities in sensory parameters. Based on this result, it would be useful to try low and medium levels of this compound in different combinations. These findings indicate that HAP-enriched chitosan coatings have potential as a promising delivery system for the effective and controlled transport of bioactive ingredients in the food industry.
AtıfScopus5WoS5OpenAlex5İncele - MakaleYalnız künye2025Scopus SJRQ2Investigation of Mechanical Properties of Jute and Tea Waste-Reinforced Epoxy Composite Material Produced by Vacuum Assisted Resin Infusion Molding
Dogan, Akar; Mahmat, Aybars; Agar, Salih
Recently, the production of materials obtained from plant sources has been increasing due to their environmentally friendly and sustainable sources. Natural fibers and waste materials offer a remarkable alternative in composite production due to their biodegradability, low cost and renewability. In this study, composite materials were produced using hybrid Jute and industrial tea waste-reinforced epoxy materials by vacuum assisted resin infusion molding. In this context, the reason for using natural and industrial resources such as jute fiber and tea waste is to contribute to both the improvement of mechanical properties and the reduction of environmental impacts. It was observed that tensile and flexural strength decreased as the amount of tea waste increased. Conversely, the energy absorbed during the quasi-static punch shear and Charpy impact tests increased, unlike the tensile and flexural strength. Approximately 50% decrease was observed in the tensile strength of the 60% tea waste reinforced material compared to the pure jute composite material. In Charpy impact and quasi-static punch shear tests, a 5% increase in the energy absorbed in the 60% tea waste reinforced composite materials was obtained.
AtıfScopus2WoS1OpenAlex1İncele - MakaleAçık Erişim2025Municipal Solid Waste Landfill Site Selection: Integrating Multi-Criteria Decision-Making Methods and Mathematical Modelling-A Case Study
Derse, Onur; Polat, Elifcan Göçmen
Increasing solid waste amount arisen from the urbanization and population growth is an inevitable outcome in many countries. Solid waste has become one of the serious environmental problems and peculiar solid waste pathways are required to prevent contamination of environment. The optimal planning of the waste management should comprise the operations such as minimization, collection, landfilling and recycling of the waste. Also, location selection for landfill of municipal solid waste (MSW) is an effective step even essential, due to growing area shortage for waste disposal. In this respect, landfilling of MSW has been addressed in Tunceli, Turkey using an integrated approach. The Fuzzy Analytical Hierarchy Process (Fuzzy-AHP), a multi-criteria decision-making (MCDM) method, is utilized to decide the weights of the environmental, technical, economic, and social criteria regarding uncertainty. Then, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is conducted to rank the alternative landfill districts. Finally, the sub locations of selected district are mathematical modelled regarding transport cost, investment cost and demand with an integer linear programming model. The computational results indicate the proposed method effectiveness with a systematic approach by integrating MCDM and mathematical modelling.
AtıfScopus2OpenAlex3TR Dizin1
İncele - MakaleYalnız künye2025Scopus SJRQ2Chromium removal with walnut shells and oak branches, adsorption studies, and kinetics
Fırat, Tülay
This study investigates the chromium sorption properties of walnut shells (WS) and oak branches (OB), both of which were modified using NaOH and lactic acid treatments. The characterization of these adsorbents was carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), point of zero charge (pHpzc) analysis, and Brunauer–Emmett–Teller (BET) surface area measurements. According to BET results, WS exhibited higher surface area values compared to OB. The pH and pHpzc measurements revealed that acidic functional groups are more prevalent than basic ones on both adsorbents. Batch experiments were conducted to evaluate the chromium ion sorption capacities of WS and OB. To further understand the adsorption mechanism, the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were analyzed, with the Langmuir and Freundlich models being widely recognized for describing adsorption in single-solute systems. The equilibrium data aligned best with the Langmuir isotherm, while the kinetic data were modeled using pseudo-first-order and pseudo-second-order kinetics. The maximum chromium sorption capacity for WS was determined to be 30.51 mg/g. The energy values calculated from the D-R equation for chromium adsorption onto WS and OB were 13.49 kJ/mol and 15.71 kJ/mol, respectively, indicating that the adsorption process is primarily driven by physical adsorption.
AtıfScopus3WoS3OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Monitoring of organic micropollutant behavior and fate in a full-scale conventional biological urban wastewater treatment plant
Demirbilek, D.; İpek, U.; Yetis, U.
Organic micropollutants, found at trace levels in nature, are causing significant concern due to their toxic, carcinogenic, and mutagenic effects. In this study, the fate and removal of organic micropollutants were monitored covering all seasons in an urban wastewater treatment plant in Turkey. The plant influent, effluent, and aeration basin were sampled seven times in the years of 2019–2020; and three surfactants (linear alkylbenzene sulfonate, nonylphenol mono-di-ethoxylate, nonylphenol), polychlorinated biphenyls and polyaromatic hydrocarbons were monitored in this context. The plant was being operated in the endogenous respiration phase during the monitoring period without sludge removal. Results obtained showed that the highest NH3-N removal (41%) of the study period was realized in March when the lowest mixed liquid volatile suspended solids value (380 mg/L) and the lowest sludge age were observed. In this month, the highest organic micropollutants removal efficiency was obtained in relation to the increased metabolic activity. On the other hand, in August, when the highest mixed liquid volatile suspended solids value (1,750 mg/L) was observed, the lowest organic micropollutants removal was recorded, with the lowest NH3-N removal (6%). The removal of linear alkylbenzene sulfonate and nonylphenol mono-di-ethoxylate was high during the period, and microorganisms could metabolize these pollutants efficiently. Polychlorinated biphenyls, polyaromatic hydrocarbons, and nonylphenol were resistant to metabolic degradation, so they were present in high amounts at various stages of the treatment process. Due to the poor plant treatment performance, a high quantity of organic micropollutants was discharged into the receiving environment.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Thermophysical properties and Optimization of modified palm Oil-Amine reinforced biocomposites for lightweight and insulating applications
Şahal, Hakan; Aydoğmuş, Ercan; Arslanoğlu, Hasan
The aim of this study is to investigate various thermophysical properties of modified palm oil-amine (MPOA) reinforced biocomposites to optimize these materials to meet the requirements of lightness and insulation. The effects of MPOA addition to biocomposites on bulk density, surface hardness, thermal conductivity coefficient, and activation energy have been evaluated. In addition, the structural and physical properties of these biocomposites are aimed to determine their potential use as lightweight and thermal insulation materials. The results show that MPOA incorporation significantly affects the bulk density, Shore A hardness, thermal conductivity, and thermal stability of biocomposites. The addition of MPOA provides significant benefits for lightweight biomaterials by reducing bulk density. However, high MPOA content decreases the surface hardness of the biocomposite, and with zirconium silicate (ZrSiO4), this drawback is eliminated and the curing time is reduced. Increasing MPOA ratios also improve the insulation properties of biocomposites by reducing the thermal conductivity coefficient. Thermal decomposition experiment results show that higher MPOA content reduces thermal stability. Scanning electron microscopy (SEM) reveals that high levels of MPOA lead to increased surface porosity and irregularities, negatively affecting surface morphology. An optimal MPOA reinforcement level of 5 wt% provides a balance between desirable properties such as reduced density and improved thermal insulation while minimizing adverse morphological effects. Fourier-transform infrared spectroscopy (FTIR) confirms the presence of epoxy resin and the successful chemical modification of palm oil to create bioepoxy feedstock. MPOA reinforcement offers benefits such as reduced bulk density and improved thermal insulation while addressing challenges in surface morphology, mechanical properties, and thermal stability. The study concludes that biocomposites with 5 wt% MPOA provide optimum stability, making them suitable for applications requiring lightweight and thermally insulating materials without significantly compromising structural integrity. This research, the long-term performance of biocomposites, and future investigations into their potential applications will further expand their practical applicability.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ4EVALUATION OF IMPLEMENTATION STRATEGIES IN THE CONTEXT OF ZERO-WASTE CITY AND CIRCULAR ECONOMY CONCEPT
Derse, Onur; Polat, Elifcan Göçmen
In recent years, there is a growing interest for waste systems in many countries around the world due to inevitable consequences of major environmental concerns. Urbanization, consumption styles, rapid developments of technologies have increased the consumption inevitably brings about the waste generation, which significantly poses risks to the environment. Although most papers have focused on waste management problems, there is a great gap of evaluation of implementation strategies for the zero-waste city and circular economy concepts. The goal “zero-waste” is strategically achieved with enriched engineering methods including all stakeholders to overcome the challenging waste issues. In this context, this study presents a systematic approach of implementing the policies and strategies focused on the most essential dimensions analysis associated with zero-waste and circular economy based on the PESTEL (political, economic, social, technological, environmental, and legal). In the study, Best-Worst Method (BWM) is first provided to evaluate a range of zero-waste implementation strategies which are essential for planners and policymakers. In addition, computational results are compared with the Stepwise Weight Assessment Ratio Analysis (SWARA), and the Fuzzy Analytical Hierarchy Process (F-AHP) methods to validate the results, and the results of the methods were found to be consistent. Environmental, economic and technological dimensions were obtained as the most influential strategies. According to the results of BWM and Fuzzy AHP methods, the four most important sub-strategies are S16 (Implementing a closed loop chain), S13 (Promoting sustainability), S5 (Investing in waste management infrastructure) and S12 (Green energy technologies). It is seen that these strategies are mostly environmental. According to the SWARA method, the most important sub-strategies under the economic dimension are S5, S4 (Providing economic incentives), and S6 (Development of green finance initiatives). The findings should also encourage the practitioners and researchers, as the detailed evaluation of strategies in terms of the zero-waste and circular economy provides a database to transform current cities into zero waste cities.
AtıfScopus3WoS1OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ2Advanced synthesis and comprehensive characterization of nanoparticle-reinforced epoxy-based biocomposites derived from modified palm oil
Şahal, Hakan; Aydoğmuş, Ercan; Canpolat, Erdal; Kaya, Mehmet
In this research, new biocomposites were synthesized by two-step modification of palm oil (MPO). The raw material (MPOSA) was epoxidized in the first step and obtained by reacting with 4,4-diaminodiphenyl sulfone in the second step. Silicon carbide (SiC), MPOSA, bisphenol A diglycidyl ether, and epoxy resin were used to obtain the biocomposites. After this process, necessary physical tests and chemical analyses were performed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyses were used to characterize the biocomposites. The research included measurements of bulk density, Shore D hardness, thermal conductivity, and thermal stability of the biocomposite. The results indicated that MPOSA reinforcement decreased the bulk density of the biocomposite in proportion to the doping level, and Shore D hardness tests revealed a decrease in hardness with the addition of MPOSA. The increase in MPOSA reinforcement also led to a reduction in the thermal conductivity coefficient. In experimental studies, the optimum reinforcement ratio was determined as 1 wt.% nano-SiC, 10 wt.% glass fiber, and 10 wt.% MPOSA. Excessive MPOSA reinforcement adversely affected the matrix structure and pore distribution of the nanocomposite due to aggregation due to increased intermolecular interaction. Thermal decomposition results showed that MPOSA reinforcement reduced the activation energy of the nanocomposite. This study successfully developed an economical, environmentally friendly, and easily processed biocomposite and contributed to the development of functional and sustainable alternatives.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ1The Extraction of Rare-Earth Elements (REEs) from Spent Nickel–Metal Hydride (Ni–MH) Batteries by Bifunctional Ionic Liquids (Bif-ILs): Process Optimization and Kinetics Modeling
Erust, Ceren
The cathode material of nickel–metal hydride (Ni–MH) batteries includes nickel, cobalt, and rare-earth elements (REEs) such as La, Ce, Nd, and Pr, which are among the critical raw materials (CRMs). Ionic liquids as the environmentally friendly approaches are proposed by various investigations for the extraction of critical metals from spent Ni–MH batteries. In this study, three different Bifunctional Ionic Liquids (Bif-ILs) were designed for comparative studies, namely Aliquat 336–Cyanex 272 (AL–CY), Aliquat 336–PC88A (AL–PC), and Aliquat 336–D2EHPA (AL–D2). The extraction results indicated that temperature has a direct effect on the extraction of critical metals in the presence of all Bif-ILs. Among three types of Bif-ILs, AL–D2 has an optimal extraction power (La: 98.8%, Ce: 94.2%, Nd: 99.2%, and Pr: 98.4%) after precipitation of 99.99% of Ni and Co. Furthermore, kinetics modeling is used for reaction mechanisms investigation. Results indicated that the mixed controlled model by shrinking core model (diffusion controlled and chemical reaction controlled) was the best model fitted to all data (coefficient of determination (R2) > 0.90). according to the Arrhenius equation, activation energies for all REEs in the presence of all Bif-ILs are between 13 and 42 kJ/mol that reflects a mixed controlled reaction.
AtıfScopus2OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ1Mechanical, durability and microstructure properties of eco-friendly self-compacting mortars with addition of volcanic scoria, silica fume and boron waste as cement replacement
Şahin Yön, Merve
The objective of this experimental study is to investigate the mechanical and durability performances of self-compacting mortars containing industrial waste and natural stone to develop an environmentally friendly mortar. Binary series of boron waste (B), silica fume (S) and volcanic scoria (V) were formed by substituting up to 95 % by weight with Portland cement, and ternary series were formed by substituting up to 80 % by weight with Portland cement. A total of 14 mixtures and one reference mixture (R) were improved for the purpose of investigating the workability, mechanical strength and durability properties of self-compacting mortar with different binder compositions. Samples of 40x40x160 mm were produced to evaluate mechanical properties and freeze-thaw effect, 100x100x100 mm for abrasion testing and 50x50x50 mm to determine physical properties. Additionally, SEM/EDS and XRD analyses were performed to determine the microstructural characteristics of the mixtures formed. The test results demonstrated that the sole replacement of boron waste with Portland cement resulted in enhanced fluidity. Nonetheless, the 90-day compressive strengths of the S10V20 and B5S10V5 mixtures exhibited increases of 7.47 % and 5.57 %, respectively, relative to the reference, whilst the B15 series saw a 52.5 % reduction, marking the lowest 90-day compressive strength compared to the reference sample. When the freeze-thaw effect was assessed after 136 cycles, the compressive strength diminished by 8.57 %, 13.1 %, 4.13 %, 7.28 %, 6.22 %, 24.77 %, and 48.1 % in the R, B5, V5, V10, V15, B5S10V5, B5S10V10, and B5S10V15 samples, respectively. Among the samples subjected to abrasion tests, a loss of 6.5 per thousand occurred in the mass of the reference sample at the end of 6 minutes, while a loss of 11 per thousand occurred in the binary mixture containing 5 % B, which had the highest abrasion.
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