Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
4 results
Search Results
Article Citation - WoS: 5Citation - Scopus: 7Robust Multicriteria Sustainability Assessment in Urban Transportation(ASCE-Amer Soc Civil Engineers, 2023-06) Gulcimen, Sedat; Aydogan, Emel Kizilkaya; Uzal, NigmetDeveloping methodologies to facilitate the planning of sustainable transport systems for decision makers (DMs) is becoming more critical. This study proposed a methodological framework for sustainable urban transportation to make decisions during urban transportation's design and planning stages. Urban transportation alternatives were evaluated by sustainability indicators that considered a triple bottom line approach's environmental, economic, and social aspects. To choose the best alternative sustainable transportation scenarios, two multicriteria decision-making (MCDM) methods, for example, a hesitant fuzzy analytical hierarchy process (HF-AHP) and multiple attribute utility model (MAUT), were integrated. First, eight sustainable transportation indicators that considered data availability from the transport sector were selected. The weights of the selected indicators were calculated using an HF-AHP. These indicators included carbon dioxide (CO2) emissions, energy consumption, depletion of nonrenewable resources, operational and maintenance costs, fuel and taxes, the number of fatalities or injuries, and motor vehicles for public transport per 10,000 population. Finally, sensitivity analysis was applied to validate the robustness. Based on HF-AHP results, the number of fatalities or injuries was the most significant among the eight indicators, with a 0.158 normalized weight (N-i). The results of this integrated methodology highlighted that Alternative 11, which was dominated by low-motorized vehicles (low-MVs), was the best sustainable alternative and Alternative 1 was the worst sustainable alternative, which was dominated by high-MVs with 0.69 and 0.27 total utility values, respectively. Low-motorized urban transportation alternatives showed higher sustainable performances than the motorized and high-motorized alternatives. This study proposed a novel and robust methodology for decisions on sustainable urban transportation projects and renovating current urban transportation systems.Article Citation - WoS: 46Citation - Scopus: 52Life Cycle Assessment of Lightweight Concrete Containing Recycled Plastics and Fly Ash(Taylor & Francis Ltd, 2020-06-05) Ersan, Yusuf Cagatay; Gulcimen, Sedat; Imis, Tuba Nur; Saygin, Osman; Uzal, NigmetResearchers put significant effort to decrease the environmental impact of concrete by using industrial by-products as an alternative binder. However, the considerable environmental impact still exists due to the consumption of natural resources as aggregates. Natural aggregates are the most used resources by volume in the construction sector. Therefore, it is necessary to investigate by-products as an alternative to natural aggregates as well. This study presents the environmental impact of lightweight concrete (LWC) produced by replacing natural aggregates with recycled waste plastic (polyethylene) (RWP) and partially replacing Portland cement with Class F fly ash (FA). Life Cycle Assessment (LCA) was performed to compare a conventional LWC, containing pumice as natural aggregate and Portland cement as a binder, with green LWC, containing 30% RWP as pumice replacement and 20% FA as cement replacement. These scenarios were evaluated in terms of global warming potential, abiotic depletion, ozone layer depletion, terrestrial ecotoxicity, photochemical oxidation, acidification and eutrophication. LCA was coupled with mechanical tests at 7 days and 28 days. RWPs were found to be an environment-friendly replacement material for natural lightweight aggregates with an overall decrease in all CML-IA impacts except eutrophication. Tested green mix design also provided sufficient strength for nonstructural applications.Article Citation - WoS: 9Citation - Scopus: 11Evaluation of Diatomite Substitute With Thermal Power Plant Waste Fly Ash in Sustainable Geopolymer Through Life Cycle Assessment(Springer, 2025-02-28) Ilkentapar, Serhan; Orklemez, Ezgi; Durak, Ugur; Gulcimen, Sedat; Bayram, Savas; Uzal, Nigmet; Atis, Cengiz DuranThis research demonstrates the potential of diatomite as a fly ash replacement to improve mechanical properties and environmental sustainability and presents it as a viable alternative for sustainable construction. Additionally, a life cycle assessment (LCA) was conducted on the produced mortars to quantitatively compare their environmental impacts using a cradle-to-gate approach. In mixtures, it was used by replacing the diatomite in the ratios of 1%, 2%, 3%, 4%, and 5% by weight of the fly ash. Workability, unit weight, flexural and compressive strength, abrasion resistance, elevated temperature resistance and microstructure analysis were carried out. The results indicated that replacing 1%, 2%, and 3% diatomite increased the compressive and flexural strength of mortars due to their higher specific surface area. Two percent replacement of diatomite provided the best results. FESEM results of 3% diatomite inclusion showed more intense and compact microstructure of geopolymer. Diatomite inclusion increased the abrasion resistance of geopolymer. Since 2% diatomite replacement was found to be optimum, the LCA results showed that geopolymer mortar with 2% diatomite has 25% lower impacts in terms of global warming potential and 10% lower impacts in terms of terrestrial ecotoxicity than conventional Portland cement mortar.Article Citation - WoS: 6Citation - Scopus: 6Comparative Life Cycle Assessment of Retort Pouch and Aluminum Can for Ready-to Bean Packaging(Springer, 2023-09-12) Gulcimen, Sedat; Ozcan, Ozlem; Cevik, Selin Babacan; Kahraman, Kevser; Uzal, NigmetSince packaging contributes to severe environmental impacts in food production, alternatives of packaging materials that satisfy customer needs while minimizing environmental impacts in a cost-effective manner should be preferred for food product sustainability. This paper compares two different packaging materials (aluminum cans and retort pouches) with a life cycle approach to assess the environmental impacts of ready-to-eat bean packaging. The life cycle assessment (LCA) was used to define and compare the environmental performance of ready-to-eat beans in aluminum cans and retort pouches. The gate-to-gate approach was used in the LCA, with a functional unit of 1 kg of packaged ready-to-eat bean product. Inventory for packaging in retort pouch was created in collaboration with Duru Bulgur Company (Karaman, Turkey) and the data for ready-to-eat beans in the aluminum can were gathered from the literature. The findings show that ready-to-eat beans in retort pouches have lower environmental impacts than ready-to-eat beans in aluminum cans. The packaging and washing processes for both ready-to-eat beans packaged in aluminum cans and retort pouches had the greatest environmental impact. In ready-to-eat beans production, retort pouch provides 87% better environmental performance than aluminum can in terms of global warming (GW). Overall, the results demonstrated that replacing aluminum cans with retort pouches in ready-to-eat bean production can significantly reduce environmental effects in all impact categories. [Graphics] .