RESUMO
In this study, the effects of nanoparticle addition to internal combustion engines were investigated. Firstly, engine coolant was prepared by mixing nanoparticles with water in different ratios (0%, 0.15%, 0.3%, 0.5% and 0.6%). Nanoparticles were investigated by SEM and XRD techniques. Then, the prepared coolants with different ratios of nanoparticles were tested on the engine at different loads (2.5 kW, 3.8 kW, 6 kW, 9 kW and 10 kW), and their heat transfer performances were investigated. Then, an ANN model was trained using the results, and the optimal TiO2 nanoparticle doped mixing ratio (0.26%) was determined. At the last stage, the techno-economic analysis of the TiO2 added coolant determined with the help of ANN was carried out, and the payback period and cumulative net present value were determined. Unlike other studies, ANN and economic analyses were performed and a contribution to the literature for the use of nanoparticle doped liquids was presented. The results show that the highest improvement in heat transfer performance is in the case of 0.6% nanoparticle addition with 40.8%. According to the ANN study, the highest performance increase is with the addition of 0.26% nanoparticles. The economic analysis made according to the result of the ANN study shows that the payback period will be less than 4 years.
RESUMO
Environmental and social awareness are the key elements of the sustainable tire industry. End-of-life tire (ELT) waste flow is an important environmental problem worldwide since it produces severe air, water, and soil pollution issues. Significant advancements have been made in ELT management in the last few years. As a result, ELTs should not only be regarded as waste but also as a source of environmentally friendly materials. Besides, sound ELT management has vital importance for circular economy and sustainable development. Over the last decade, ELT management has attracted many researchers and practitioners. Unfortunately, a comprehensive review of the ELT management area is still missing. This study presents the first critical review of the whole ELT management area. It aims to present an extensive content analysis overview of state-of-the-art research, provide its critical analysis, highlight major gaps, and propose the most significant research directions. A total of 151 peer-reviewed studies published in the journals between 2010-2020 are collected, analyzed, categorized, and critically reviewed. This review study redounds comprehensive insights, a valuable source of references, and major opportunities for researchers and practitioners interested in not only ELT material flow but also the whole waste management area.
Assuntos
Veículos Automotores , Gerenciamento de Resíduos , Poluição AmbientalRESUMO
As the number of end-of-life vehicles (ELVs) increases rapidly, their management has become one of the most important environmental topics worldwide. This study is conducted to evaluate various alternatives for location selection of an authorized dismantling center (ADC) for ELVs using a multi-criteria decision-making (MCDM) approach. An intuitionistic fuzzy MCDM-based combinative distance-based assessment (CODAS) approach is proposed to aid waste managers and solve their problem. The intuitionistic fuzzy weighted averaging operator is utilized to aggregate individual opinions of decision-makers into a group opinion. The intuitionistic fuzzy Euclidean and Hamming distances are used to calculate the assessment score of alternatives. A real-life case study of Istanbul is provided to illustrate how this novel intuitionistic fuzzy MCDM-based CODAS approach can be used for alternative selection in real-world applications. The comparison with the available state-of-the-art intuitionistic fuzzy set-based MCDM approaches approves the validity and consistency of the proposed intuitionistic fuzzy CODAS approach. The intuitionistic fuzzy CODAS, WASPAS, and TOPSIS approaches generate exactly the same ordering of alternatives for the new ADC in Istanbul. The results show that the intuitionistic fuzzy CODAS approach indicates valid results and is an effective decision-making technique for vagueness and uncertainty nature of linguistic assessments.