Cleaner Engineering and Technology最新文献

The study investigates the effect of wood ash (WA) on the geotechnical behavior of low-plasticity clay (CL) soil with the aim of improving soil properties while minimizing environmental impact. Various WA ratios (0 %, 8 %, 16 %, 24 %, and 32 % by the dry weight of the soil) were added to the natural soil and then tested for their Atterberg limits, specific gravity, standard compaction, unconfined compression strength (UCS), California bearing ratio (CBR), direct shear strength, consolidation settlement, and permeability. Results showed that a higher WA content increases the plastic limit (PL) and liquid limit (LL). However, the plasticity index (PI), linear shrinkage (LS), specific gravity, free swelling, compression index, and hydraulic conductivity decrease as the WA content increases up to 32 %. Incorporating WA into the CL results in an increasing trend in the optimum moisture content (OMC), while a decreasing trend is observed in the maximum dry density (MDD). The UCS and CBR exhibit remarkable enhancement with the addition of WA up to 24 %; beyond that limit, a subsequent decrease occurs in both parameters. In addition, the enhancement of the subgrade with a WA content of 24 % leads to a reduction in the thickness of the subbase layer by about 46 %. Moreover, a higher content of WA increases cohesion and friction angle significantly. Consequently, the optimal improvement of clay soil can be achieved by incorporating 24 % WA.

In this study, the performance and emissions of a single-cylinder diesel engine were analyzed with the aim of enhancing the lubrication properties of the engine oil. Nano-lubricants were created using CuO₂-TiO₂ with a mean diameter of 40 nm, at weight percentages of 0.25, 0.5, and 0.75 %. These nanoparticles were evenly mixed and distributed in the base oil. The results demonstrated a 2.5 % increase in useful power output, a 2.6 % increase in engine torque, an 11.06 % improvement in engine thermal efficiency, and a 5.34 % reduction in specific fuel consumption. Furthermore, the impact of different percentages of copper nano-oxide and titanium nano-oxide on emissions of measurable pollutants (CO₂, CO, and NOx) was found to be significant. Notably, the addition of CuO₂-TiO₂ nanoparticles at lower levels did not affect the level of NOx emissions. It sounds like the study referring to demonstrate the potential benefits of using nano-lubricants with CuO₂-TiO₂ in a diesel engine. The results indicate improvements in power output, engine torque, thermal efficiency, and fuel consumption, as well as a notable impact on emissions of CO₂, CO, and NOx. This research could have important implications for improving the performance and environmental impact of diesel engines.

In this work, carboxymethyl cellulose-graphene oxide (CMC-GO) nanocomposite was prepared and used as a low-cost adsorbent to remove Pb²⁺ and Cd²⁺ from aqueous solution. CMC-GO was characterized using various techniques such as FTIR, XRD, TGA, zeta potential and SEM with EDX. The optimum pH, adsorbent dose, time, and percentage of removal were found 5.0, 1.0 g/L, 60 min, and 96.3% for Pb²⁺ and 5.5, 1.5 g/L, 60 min, and 82.5% for Cd²⁺, respectively at an initial concentration of 200 ppm. The Freundlich isotherm model and pseudo-second order kinetics were configured properly with experimental data and maximum capacity was found 213.21 mg/g and 134.04 mg/g for Pb²⁺ and Cd²⁺ ions respectively. The positive value of enthalpy (ΔH) and negative values of Gibbs free energy (ΔG) for the Cd²⁺ and Pb²⁺ sorption process indicate endothermic nature of sorption and spontaneous at room temperature. This study revealed that the prepared composite could be cost-effective, efficient and viable adsorbent for the remediation of toxic Pb²⁺ and Cd²⁺ pollution from water bodies as well as wastewater treatment.

The world's demand for water and energy is continuously growing due to population increase. Traditional water systems are driven by energy produced using fossil fuels, which lead to global warming due to rise of greenhouse gas pollution. Global warming is an increasing motivation to integrate renewable energy resources in water systems for different purposes like water pumping, water supply, and water distribution systems. As a result, to have a smart, sustainable and low-cost water system, renewable resources, energy management, and monitoring should be simultaneously implemented. Therefore, this paper provides a comprehensive review of the research conducted on solutions and effects of integrating different types of renewable resources on water systems. As essential tools for secure integration of renewable resource in the water industry, the pivotal role of energy management and intelligent technologies within the water system have been explored. This review confirms the potential of achieving smart and sustainable water systems by simultaneously considering the use of renewable resources, conducting energy management strategies, and smartening the water system; however, further research is essential to improve water system performance and increase the efficiency of the system.

As environmental awareness takes centre stage in business, entrepreneurship research has established a dedicated subfield for sustainability-driven ventures. The growing emphasis on sustainable business practices has led entrepreneurship research to identify entrepreneurship-related sustainability as a critical subfield. However, the inconsistent terminology used, such as “green entrepreneurship,” “ecopreneurship”, and “entrepreneurship” (ENP), reflects the fragmented nature of research in this area. A Systematic Literature Review on entrepreneurship-related sustainability was conducted to address this, focusing on the term “enviropreneurship” and applying PRISMA guidelines for transparency and methodological standardization. A total of 67 research articles published between 2013 and 2022 were analyzed to identify key themes and subthemes. This analysis resulted in a comprehensive definition of ENP and a cohesive research agenda for the future. The findings revealed significant shortcomings in standardized reporting procedures, highlighting the need for greater methodological openness and harmonization. To address this, the widespread adoption of PRISMA principles adapted to the specific needs of ENP research is advocated to enhance rigour, comparability, and reliability in this multidisciplinary field. Categorizing the research articles provided valuable insights into the research direction and specific focus areas, revealing a shift towards practical application and evaluation alongside conceptual exploration and analysis, which is inherent to any research field.

Climate change and sustainable development are interconnected and pressing global challenges requiring urgent attention. Researching the trends in climate change and sustainable development through a bibliometric study is essential for addressing urgent global challenges, identifying gaps in knowledge, informing policy decisions, and promoting collaboration within the academic and research community. This study aims to conduct a bibliometric analysis to investigate the research trends, collaboration network, and thematic evaluation of publications on climate change and sustainable development. 1696 papers from 1992 to 2022 were selected using the PRISMA framework from the Scopus database. We employ Bibliometric R and VOSviewer software to conduct bibliometric analysis. The study found that literature and citations on climate change and sustainable development have grown significantly. The Chinese Academy of Sciences leads in productivity, while the USA, China, and India are the most productive countries. Surprisingly, 44 papers received over 100 citations, while 50% received less than five. Trending topics include COVID-19, urbanisation, attitude, climate change mitigation and adaptation, etc. The evaluation of research themes reveals a shift towards climate change to mitigation, adaptation, and sustainable development goals. The findings serve as a valuable resource for researchers, policymakers, and practitioners, facilitating a deeper understanding of the evolving knowledge of change and sustainable development research and identifying emerging research areas. The shift from a general emphasis on climate change to more specialised themes underscores the necessity for focused examinations within distinct domains, including but not limited to climate change adaptation, mitigation, and the pursuit of sustainable development goals.

The purpose of this study is to assess technical and financial challenges for renewable energy project alternatives with a novel model. Firstly, a set of technical and financial challenges is created by considering the results of the literature evaluation. After that, the weights of these values are computed by Sine Trigonometric Pythagorean Fuzzy (ST-PFN) DEMATEL. The next step includes the ranking of six renewable energy alternatives with interval valued Spherical fuzzy multicriteria analysis with ratio and categorical data (SF MAIRCA) approach. Entropy and ARAS methodology are also considered to make comparative evaluation. Similarly, sensitivity analysis is also conducted for 10 different cases. It is concluded that the analysis results of all methods are the same. Therefore, it is identified that the findings of the proposed model are reliable and coherent. Identification of the most crucial technical and financial challenges of the renewable energy projects is the most important contribution of this manuscript. Furthermore, preferring the sine trigonometric structure in the proposed model will provide superiority to this model in many respects. It is concluded that difficulty in accessing finance for local projects is the most significant challenge for renewable energy investments. Moreover, competitive pricing of renewable sources is another critical issue in this regard. Additionally, it is identified that solar is the most successful renewable energy alternative to overcome technical and financial challenges.

This systematic review critically examines the intersection of digital transformation and circular economy (CE) principles within the built environment. While digitalisation has been shown to enhance efficiency, safety, and sustainability in construction, its role in fostering circularity is less established. This study analyzes literature from 2010 to 2022, focusing on how digital technologies such as open-BIM, digital twins, material passports, blockchain, RFID, and gamification can integrate into and enhance the circular building lifecycle. The findings reveal that while digital tools are pivotal in design and construction phases, their application to existing structures is less straightforward, with challenges including the absence of digital twins for demolished structures, the high costs of retrofit digitalisation, and the predominant focus on environmental benefits over practical implementation. The review also highlights the need for a unified digital transformation strategy and greater cross-industry collaboration. Future research directions are proposed, including the development of localized material banks, the application of RFID in circularity, the scope of Design for Disassembly (DfD) tools, digital inventory of existing buildings, the circularity of Life Cycle Assessment (LCA) databases, and policy implications for promoting circular construction practices.

This paper presents a numerical investigation of the performance of a rectangular storage solar collector with three different absorber plate shapes: smooth, parabolic, and triangular. The research employs three-dimensional, unsteady modeling using COMSOL software version 5.5 to simulate a solar storage collector system in Kufa-Najaf's climatic conditions. Two days in November and July were selected to evaluate the system's performance under various atmospheric conditions. The results showed that the highest water temperature for a no-load condition was 36.2 °C in November and 51.7 °C in July. For a triangular corrugation absorber storage collector under load, the largest temperature difference between the outflow and inflow temperatures was 14.9 °C at 1 p.m. and 11.9 °C at sunset in November, while the maximum temperature difference was 13.4 °C at 4 p.m. in July. The study also found that the total efficiency of the triangular corrugation absorber storage collector was higher than that of the other designs, and generally, the total efficiency under no-load conditions was lower than the load. The present work offers a novel solar storage collector configuration with a parabolic or triangular roughened integrated plate absorber, which enhances heat transfer, promoting energy efficiency and improving outlet water temperature.