Tribological Evaluation of Lead-Free MoS2-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications

Solid lubricants, such as MoS2 have been widely used in the aerospace industry with the primary purpose of reducing the friction and wear of tribological interfaces. MoS2 based solid film lubricants are generally doped with other compounds, which can help overcome some of their limitations related to environmental conditions. For instance, compounds like Sb2O3 and Pb have been traditionally used to improve the endurance life of these lubricants. However, with the recent zest in transferring to eco-friendly lubricants, there is a strong push to eliminate Pb based compounds. The main purpose of this work is to better understand the influence of Pb based compounds on the tribological behavior of MoS2 based solid film lubricants as well as to critically evaluate the performance of Pb free lubrication strategies. More specifically, the baseline ‘non-green’ lubricant was doped with Pb compound and Sb2O3 and the Pb compound in the ‘Green’ alternative lubricant was replaced by more Sb2O3. The wear test was done using a ball-on-disk tribometer for specific loads and for 5000 cycles. Ex-situ analysis was conducted using Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), and micro-Raman to capture the interfacial processes of these lubricants at different loads. Overall, the non-green lubricant performed better in terms of the tribological behavior (i.e., lower friction and wear), which was attributed to the formation of a dense MoS2-based tribo-/transfer-film with the basal planes oriented in the parallel direction to the sliding. The finding on the interfacial phenomena provided critical insights into the development of novel green alternatives that may have the ability to replace Pb based compounds in the future for a sustainable environment.

Monitoring Dynamics of Vegetation Cover with the Integration of OBIA and Random Forest Classifier Using Sentinel-2 Multitemporal Satellite Imagery

The existence of vegetation in an area has an important role to maintain the carrying capacity of the environment and create a comfortable environment as a place to live. In an effort to create a sustainable environment, there are various pressures on vegetation that cause a decrease in vegetation area. Economic activity, population growth and other anthropogenic activities trigger the dynamics of vegetation cover in an area that causes land cover changes from vegetation to non-vegetation. Majalengka Regency as one of the areas with intensive regional physical development in line with the operation of BIJB Kertajati and the Cipali toll road became the study area in this research. This study aims to monitor the dynamics of vegetation cover with the proposed method namely the integration of the OBIA and Random Forest classifier using multi temporal Sentinel-2 satellite imagery. The results show that there is a decrease in the area of vegetation in the research area as much as 4,329.6 hectares to non-vegetation areas in the period 2016-2020. The vegetation area in 2020 is 84,716.07 hectares and non-vegetation area is 35,708 hectares. Thus, there has been a decrease in the percentage of vegetation area from 73.94% in 2016 to 70.35% in 2020, meanwhile for non-vegetation areas there has been an increase from 26.06% in 2016 to 29.65% in 2020.

The Electronic Waste Management Crisis- A Situation Analysis of Zambia

Globally, the technological era has seemingly increased the environmental burden of many Low income countries in the management of electronic waste. An increase in the use of electrical and electronic equipment potentially relates to an increase in e-waste in the environment. Poorly managed ewaste degrades the environment in various ways such as through percolation of toxicants into the soils and leaching into aquatic systems. As Zambia steadily develops, the use of EEEs is a major threat in the increased amounts of e-waste thus placing more demand on environmental institutions as well as wellestablished and sustainable e-waste management systems. Environmental issues are complex and diverse, in this view; waste management is an integral part of a sustainable environment thus making effective electronic waste management categorically fundamental. This study employed a mixed method approach (concurrent nested) to assess the effectiveness of electronic waste management facilities in Lusaka. In this study, the inclusion and exclusion criteria were used so as to select the participants by use of questionnaires and interviews. This study showed that in Zambia, e-waste has not been given the same attention as other waste types. The knowledge base of electrical and electronic equipment users is very shallow as this study indicated that most EEE consumers have little or no knowledge of the toxic components of electronic waste. Further, available environmental institutions do not currently have the capacity to quantify e-waste that is generated in the country. Moreover, the e-waste that is appropriately disposed of is exported to neighboring countries recycling. The study concluded that Zambia lacks the needed expertise and facilities to adequately handle e-waste. However, information obtained from EEE users and e-waste generators clearly indicated that inasmuch as there could be efforts by environmental institutions to manage e-waste, there hasn’t been local authority effort to specifically handle e-waste or rather sensitize the users of EEEs on e-waste issues. The study thus recommended the following; creation of e-waste black market, further Studies, Laws to prohibit dumping of e-waste, Promotion of E-waste education amongst EEE users, Promotion of E-waste education amongst EEE users, Repurpose old devices before purchasing new ones.

Diversity of Gut Methanogens and Functional Enzymes Associated With Methane Metabolism in Smallholder Dairy Cattle

Methane is a greenhouse gas with disastrous consequences when released to intolerable levels. Ruminants produce methane during gut fermentation releasing it through belching and/or flatulence. To better understand the diversity of methanogens and functional enzymes associated with methane metabolism in dairy cows, 48 samples; six rumen and 42 dung contents were collected and analyzed using a shotgun metagenomic approach. The results indicated archaea from 5 phyla, 9 classes, 16 orders, 25 families, 59 genera, and 87 species. Gut sites significantly contributed to the presence and distribution of various methanogens (P<0.01). The class Methanomicrobia was abundant in the rumen samples (~ 39%) and in dung (~44%). The most abundant (~17%) methanogen species identified was Methanocorpusculum labreanum. However, some taxonomic classes were not classified (~ 6% in the rumen and ~4% in the dung). Furthermore, five functional enzymes: Glycine/Serine hydroxy methyltransferase, Formylmethanofuran—tetrahydromethanopterin N-formyltransferase, Formate dehydrogenase, Anaerobic carbon monoxide dehydrogenase and Catalase-peroxidase were associated with methane metabolism. KO0600 module and Enzyme Commissions (1.11.1.6 & 2.1.2.1) were common for dung and rumen fluid’s enzymatic pathways. Functional analysis for the enzymes identified were significant (P<0.05) for 5 metabolism processes. Breeding for tolerable methane emitting dairy cattle for a sustainable environment should be undertaken.

Fostering Civic Engagement in Smart Cities

Smart cities are modern concepts that aim to provide better living conditions to their citizens by creating a sustainable environment. Citizens are the key partners behind the development of a smart city. They have to be aware about the civic duties and responsibilities towards the community. In this chapter, the authors analyze the concept of smart cities and what are the issues and challenges in India for developing a smart city. The authors also examine various civic engagement initiatives by the government of India. The objective of this chapter is to find the role played by public libraries in creating smarter communities and how they will help in promoting civic engagement activities.

Redefining Smart Cities, Urban Energy, and Green Technologies for Sustainable Development

Increasing greenhouse effects and global warming have been threatening the environment. Cities have directed their development strategies towards smart policies aiming to improve the quality of life of their inhabitants through sustainable environment and energy resources. Therefore, it became a very critical strategy to redefine urban energy sources and apply green technologies in all means of city lives for sustainable cities and reaching Sustainable Development Goals. In this chapter, background information for the role of cities in climate change and environmental pollution globally will be explained. Then a theoretical framework for smart cities and their important features focusing on technology innovation, smart governance, energy efficiency, waste management, as well as green buildings, smart grid-smart lighting, and smart mobility will be analyzed. Finally, sustainable development policy suggestions for sustainable plans and programs at the urban level within the current legislative framework will be put forth.