Müfide Banar

This study aims to determine the optimal healthcare waste management methods according to the criteria selected using Multi Criteria Decision Making (MCDM) techniques. In this context, four alternative healthcare waste management methods were included: incineration, microwave irradiation, sterilization and chemical disinfection. Four criteria, including energy recovery, investment cost, emissions and volume reduction, were defined. The defined criteria were weighted using two different methods (AHP (environmental and investor approaches) and CRITIC). In the weighting results, the most important criterion is "emissions", "investment cost” and "energy recovery" for different methods. Four healthcare waste management alternatives were then compared with the AHP, COPRAS and MULTIMOORA methods. The results of AHP, COPRAS, and MULTIMOORA, using the AHP environmental weighting methods; indicate that the best alternative is “Sterilization (A3)”. However, the results of AHP, COPRAS, and MULTIMOORA, using the AHP investor weighting method, show that the best alternatives are “Sterilization (A3)” and “Incineration (A1)”. In the results obtained using the CRITIC weighting methods for AHP, COPRAS and MULTIMOORA; the best alternatives are, in order, “Sterilization (A3),” "Incineration (A1)" and "Microwave Irradiation (A2)". According to the combined ranking, incineration is the first applicable method. The recommended sequence of other methods is microwave irradiation, sterilization, and chemical disinfection.

Türkiye's EU accession process and its extensive trade relations with EU countries accelerated its transition to a circular economy. In this context, significant legal and administrative regulations related to environmental, social and governance (ESG) are being implemented in Türkiye in compliance with EU legislation. However, for the country to sustain its growth in the long term and reach the 2053 net zero emission target, it is necessary to transition to the circular economy model by establishing policies, strategies, a regulatory framework and an institutional platform. Therefore, in this study, it is aimed to make a technical and legal evaluation in order to determine the strategies in Türkiye in the light of international developments. In this context, it examines the growing global importance of sustainability and the circular economy in mitigating environmental risks and achieving Sustainable Development Goals (SDGs). Furthermore, the manuscript explores the concept of corporate sustainability requires the integration of environmental, social, and governance (ESG) factors into business decisions and processes and the significance of sustainability reporting. It discusses various international reporting frameworks and analyzes the current state of corporate sustainability reporting in Türkiye by highlighting the importance of meeting international sustainability reporting standards.

With the growing global demand for efficient energy storage solutions, phase change materials have gained attention due to their high latent heat storage capacity. This study investigates the potential use of bio-oils derived from spent coffee grounds in thermal management applications, particularly in lithium-ion batteries. Spent coffee grounds was subjected to pyrolysis at 550°C and hydrothermal processing at 200°C to obtain bio-oils, which were then incorporated into paraffin wax to form composite PCMs. The structural and thermal properties of these materials were analyzed using FT-IR, DSC and t-history. Results indicate that adding coffee-derived bio-oils to paraffin wax reduces its latent heat moderately, with hydrothermal and pyrolysis bio-oils causing slight decreases while improving the PCM’s responsiveness during rapid thermal fluctuations. Results also indicate that adding coffee-derived bio-oils to paraffin wax reduces its melting point, with the most significant reduction observed at a 3% bio-oil ratio lowering the melting point from 62°C to 38°C in hydrothermal bio-oil PCM composites. This temperature reduction suggests an improvement in the thermal management of Li-ion batteries, helping to mitigate overheating issues and enhance battery safety and lifespan. The findings highlight the potential of waste-derived bio-oils as sustainable additives for next-generation energy storage applications.

Grafen, 2004 yılında grafitten başarılı bir şekilde izole edilmesinden bu yana en ilginç karbon nanomalzemelerden birisi olarak kabul edilmektedir. Karbon-karbon sigma bağı ile birbirine bağlanmış iki eşdeğer alt kafes (sublattice) karbon atomundan oluşan petek çerçevesine sahip atom kalınlığında bir tabaka olan grafen ve grafenin türevleri, olağanüstü fizikokimyasal özellikleri nedeniyle son zamanlarda büyük ilgi görmüş, geleceğin sistemleri ve cihazları için yeni fırsatlar yaratmış ve bu da çok sayıda uygulamada kullanılmak üzere grafen talebinin artmasına neden olmuştur. Doğal kaynakların kullanımı yerine atıklardan grafen ve türevlerinin eldesi hem bu talebi karşılayabilmek hem de atıkların döngüsel ekonomi yaklaşımıyla yönetilmesi açısından önemli bir adımdır. Bu noktadan hareketle, bu derleme makalede grafen ve türevlerinin sentezlenme yöntemleri ve sentezlenmesinde kullanılan atıklar üzerinde durulmuştur.

This research aims at providing more information concerning the performance of public transport means that exist in most underdeveloped countries from an environmental and economic perspective. This study compares autorickshaws, motorcycles, 14-passenger, and 29-passenger minibuses. A cradle-to-grave life cycle assessment (LCA) and a life cycle cost analysis (LCC) for passenger transportation were carried out. The LCA analysis was carried out using the Center of Environmental Science, Leiden University (CML-IA) baseline impact assessment method. A cost model was developed to analyze the purchase, maintenance, and operation costs of passenger transportation. The LCA results reveal that in an informal transport system, lower-capacity vehicles have a better environmental performance per passenger-kilometer than higher passenger-capacity vehicles during off-peak hours. In the LCC analysis, motorcycles were revealed to be the most cost-inefficient alternative. Both LCA and LCC results show that the operational stage owing to fuel consumption has the highest impact on the environment and economy. To decrease the environmental and economic impacts of the transportation system, the first action should be focused on the operational stages of these types of vehicles.

Today, to reduce fossil fuel consumption and to prevent gas emissions that are increasing day by day, vehicles working with electrical energy have started to be produced and developed. The environmental impact of the batteries of electric vehicles, which are increasing in number, is an undeniable fact and is predicted to be a major problem. In this study, three different alternative recycling processes were selected for waste lithium-ion batteries (LIBs), namely pyrometallurgical process, hydrometallurgical process and direct recycling.These processes were compared in terms of their technical, economic, environmental and social aspects using a Multi-Criteria Decision Making (MCDM) approach.. From this point of view, in this study, entropy method which is an objective method was used to weight the criteria and Analytic Network Process (ANP) and TOPSIS methods were used to prioritise the alternatives in order to determine the best process for the recycling of waste LIBs. The alternatives were determined as being pyrometallurgical process, hydrometallurgical process and direct recycling, and these alternatives were evaluated in terms of environmental, economic, technical, and social dimensions. Afterwards, sensitivity analysis was performed. The ranking results showed that direct recycling is the best alternative (with values of 0.68 and 0.8101 for ANP and TOPSIS, respectively). In addition, sensitivity analysis was applied for the robustness of the results. As a result of the sensitivity analysis, direct recycling was found to be the best alternative.

Faz değişim malzemeleri (Phase Change Materials (PCM)), özellikle devamlı ulaşılamayan yenilenebilir enerji kaynaklarını depolayarak ve talep edildiğinde kullanılmasını sağlayarak yenilenebilir ve sürdürülebilir enerji sağlar. PCM’lerin termal enerji depolamada istenilen termodinamik, kinetik, kimyasal ve ekonomik özellikleri bir arada tek başına karşılayamamalarından dolayı farklı nanomalzemeler ile desteklenmektedir. PCM’in özelliklerini geliştirmek için kullanılan nanomalzemelerin seçimi için kritik parametreler mevcut olup, bu çalışmada inorganik nanomalzemelerin önceliklendirilmesi amaçlanmıştır. Bu noktada Çok Kriterli Karar Verme (Multi Criteria Decision Maker (MCDM)) metodolojisi oldukça kullanışlıdır. Bu çalışmada, PCM'lerde kullanılabilecek 5 farklı inorganik nanomalzeme (bakır oksit, aluminyum oksit, gümüş, titanyum oksit ve bor nitrürün) önceliklendirilmesi için Oran Analizine Dayalı Çok Amaçlı Optimizasyon Yöntemi (MULTIMOORA) kullanılmıştır. Erime noktası değişimi, gizli ısı değişimi, termal iletkenlik değişimi, ön işlem gereksinimi, toksisite ve maliyet olmak üzere 6 değerlendirme kriteri belirlenmiştir. Kriter ağırlıkları sırasıyla entropi (objektif yöntem) ve sıralama (subjektif) yöntemleriyle belirlenmiştir. Her iki kriter ağırlıklandırma yöntemine göre de erime noktası değişimi en önemli kriter olarak belirlenmiştir. MULTIMOORA sonuçlarına göre PCM'lere eklenecek en uygun inorganik nanomalzemenin bor nitrür (BN) olduğu görülmüştür.