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The increasing environmental concerns and the significant growth of the waste to energy market calls for innovative and flexible technology that can effectively process and convert municipal solid waste into fuels and power at high efficiencies. To ensure the technical and economic feasibility of new technology, a sound understanding of the characteristics of the integrated energy system is essential. In this work, a comprehensive techno-economic analysis of a waste to power and heat plant based on integrated intermediate pyrolysis and CHP (Pyro-CHP) system was performed. The overall plant CHP efficiency was found to be nearly 60% defined as heat and power output compared to feedstock fuel input. By using an established economic evaluation model, the capital investment of a 5 tonne per hour plant was calculated to be £27.64 million and the Levelised Cost of Electricity was £0.063/kWh. This agrees the range of cost given by the UK government. To maximise project viability, technology developers should endeavour to seek ways to reduce the energy production cost. Particular attention should be given to the factors with the greatest influence on the profitability, such as feedstock cost (or gate fee for waste), maintaining plant availability, improving energy productivity and reducing capital cost.

In recent decades, rapid urbanization has resulted in a growing urban population, transformed into regions of exceptional socio-economic value. By removing vegetation and soil, grading the land surface and saturating soil air content, urban developments are more likely to be flooded, which will be further exacerbated by an anticipated increase in the number of intense rainfall events, due to climate change. To date, data collected show that urban pluvial flood events are on the rise for both the UK and China. This paper presents a critical review of existing sustainable approaches to urban flood management, by comparing UK practice with that in China and critically assessing whether lessons can be learnt from the Sponge City initiative. The authors have identified a strategic research plan to ensure that the sponge city initiative can successfully respond to extreme climatic events and tackle pluvial flooding. Hence, this review suggests that future research should focus on (1) the development of a more localized rainfall model for the Chinese climate; (2) the role of retrofit SuDS (Sustainable Drainage Systems) in challenging water environments; (3) the development of a robust SuDS selection tool, ensuring that the most effective devices are installed, based on local factors; and (4) dissemination of current information, and increased understanding of maintenance and whole life-costing, alongside monitoring the success of sponge cities to increase the confidence of decision makers (5) the community engagement and education about sponge cities.

Abstract Background The African continent is known for high entrepreneurial activity, especially in the agricultural sector. Despite this, the continent's economic development is below expectations, due to numerous factors constraining the growth and sustainability of agricultural SMEs. These constraints have been exacerbated by the COVID-19 pandemic. The purpose of this study was to understand the pathways through which the pandemic affected agri-SMEs, with specific focus on assessing the differentiated effects arising from the size of the agri-SME and the gender of the owner-manager. Methods Data was collected from over 100 agri-SMEs, ranging in size from sole proprietorships with one employee to agri-SMEs employing up to 100 people, in six African countries. Mixed methods were used to analyse the data with changes in business operations arising from changing market access, regimented health and safety guidelines and constrained labour supply assessed using visualisations and descriptive statistics. Logistic regression modelling was employed to determine the set of variables contributing to agri-SME business downturn during the COVID-19 pandemic. Results All surveyed agri-SMEs were negatively affected by COVID-19-associated restrictions with the size of the firm and gender of the owner-managers resulting in differentiated impacts. The smallest agri-SMEs, mainly owner-managed by women, were more likely to experience disruptions in marketing their goods and maintaining their labour supply. Larger agri-SMEs made changes to their business operations to comply with government guidelines during the pandemic and made investments to manage their labour supply, thus sustaining their business operations. In addition, logistic regression modelling results show that financing prior to the pandemic, engaging in primary agricultural production, and being further from urban centres significantly influenced the likelihood of a firm incurring business losses. Conclusions These findings necessitate engendered multi-faceted agri-SME support packages that are tailored for smaller-sized agri-SMEs. Any such support package should include support for agri-SMEs to develop sustainable marketing strategies and help them secure flexible financing that considers payment deferrals and debt moratorium during bona fide market shocks such as the COVID-19 pandemic.

In recent years, a ban on short-haul flights for which alternative, more environmentally friendly transportation is available has been on European regulatory agendas, particularly in countries like Germany, with its well-developed high-speed rail (HSR) and a dense network of low-cost, point-to-point airline traffic. This study aims to quantify the potential impact on CO2 emissions of substituting short-haul flights with rail frequencies in 87 German air travel corridors. Using OAG data on passenger bookings and airline schedules for 2019, as well as current rail travel times, we determine the target flights by looking at the actual proportion of connecting passengers per frequency. We estimate a potential reduction in CO2 emissions of between 2.7% and 22%, depending on how strict the flight substitution is. However, the social benefits of those carbon emissions might fall short of the travel time losses experienced by the passengers. Increased investment to improve rail speeds and intermodal accessibility appears necessary before the substitution policies can be implemented.

Poor air quality (PAQ) is a global concern, especially in urban areas, and is often seen as an important element of social sustainability given its negative impact on health and quality of life. However, little research has been undertaken in cities of the developing world to explore how residents perceive poor air quality, its main causes, what control measures should be used to address PAQ and where the main responsibility rests for implementing control measures. The research described in this paper sought to address these points, using a questionnaire-based survey (n = 262) in Nigeria’s federal capital city of Abuja (n = 137) and the state-capital city of Enugu (n = 125). The survey took place during the COVID-19 pandemic (October 2020 to March 2021), and was stratified to ensure representation across a number of demographic groups such as gender, age, education and income. The results were analysed using the Kruskal–Wallis non-parametric test and Hochberg’s post hoc test available in SPSS version 28. The study found that the ranking of perceptual indicators and the main causes of PAQ had much agreement between respondents from both cities and between demographic groups. Smoke, odour and dust particles were perceived to be the most important indicators of PAQ, while the main sources of PAQ were waste and bush burning, vehicle use and power generators. The two most preferred control measures were proper waste management and the avoidance of bush burning. However, there was a significant difference between the two cities in terms of the main organisations responsible for addressing PAQ, with respondents from Abuja citing the federal government, while those from Enugu cited the state government. Interestingly, younger people in Enugu noted that the government should take more responsibility in controlling PAQ than did the older demographic in that city, but this difference was not seen in Abuja. Overall, this study reveals that residents in these two Nigerian cities clearly recognise their exposure to PAQ and it suggests that these perceptual indicators, and views on sources and interventions should be central to designing policies to control this important issue.

Packaging waste production, especially single-use containers, is exerting detrimental effects on terrestrial and aquatic ecosystems, including human health. To internalise the externalities associated with single-use containers, different instruments, including a deposit refund scheme (DRS), have been operationalised in many countries. Therefore, DRS is introduced in Scotland to reduce plastic litters by increasing recycling rates and incentivising pro-environmental behavioural change. This study addresses the complexity of single-use plastic containers by analysing consumers' perceptions regarding the introduction of DRS in Scotland. Using 940 comments from the BBC "Have Your Say" messageboard, this study adopts sentiment analysis to understand consumers' opinions about the introduction and implementation of DRS in Scotland. Findings suggest that a UK-wide scheme that is similar in terms of operations and structure is required for DRS to be successful. While consumers' knowledge and opinions about DRS are mixed, the efficacy of DRS including its relevance is questioned and raises doubts about its contribution to sustainability. The findings imply the need for UK countries to negotiate and collaborate on appropriate and attractive interventions in addressing post-consumer single-use plastic containers. The implications of the findings for policy and practice, especially in improving the operations of DRS are further discussed.

This study investigated the effects of long-term chloroquine and ethanol administration on renal fluid and electrolyte handling and kidney structure. Male Sprague-Dawley rats were orally administered with chloroquine diphosphate (20 microg kg(-1) bw) and/or ethanol (1.6 g kg(-1) bw) every third consecutive day for 4 weeks. Urine volume and total urinary outputs of Na+ and K+ were determined from 24-h samples. For detailed renal studies, rats were subsequently anaesthetised and challenged with a continuous jugular infusion of 0.077 M NaCl at 150 microl min(-1) 24 h after the last treatment. After a 3-h equilibration period, urine flow, Na+ and K+ excretion rates were determined over a 4-h period. Plasma concentrations of AVP and aldosterone were measured in unanaesthetised rats and in anaesthetised rats after hypotonic saline infusion. In separate groups, the rats were anaesthetised with an overdose of ether after 4 weeks of treatment and part of the right kidney was quickly collected and routinely processed for light microscopy. Chloroquine decreased Na+ excretion and increased plasma aldosterone concentrations in anaesthetised rats. Ethanol alone did not alter urinary Na+ outputs or aldosterone levels. Combined chloroquine and ethanol increased renal Na+ excretion, but did not affect plasma aldosterone levels. In unanaesthetised animals all treatments increased aldosterone levels by comparison with control rats. Urinary Na+ excretion was decreased by separate administration of either chloroquine or ethanol, but increased by combined treatment. Microscopic studies showed that concurrent chloroquine and ethanol administration induced extensive damage of the proximal tubule and collecting ducts cells. The results of this study suggest that alcohol consumption and chloroquine administration could result in diminished renal function possibly due to alteration of renally active hormones or kidney morphology.