In: The International journal of construction education and research: a tri-annual publication of the Associated Schools of Construction, Band 2, Heft 2, S. 151-166
Abstract The ability to get clean water is the most urgent birthright for human beings. The scarcity of safe drinking water is a major challenge in both developed and developing countries. Due to overpopulation, industrial revolution advancements, and agricultural evolution, this challenge has become crucially influential. Several studies on solar desalination are being conducted to create novel models that will improve the efficiency and production of these units. Because of their higher evaporation, condensing, exposure, and output rates than traditional stills, vertical distillers have lately piqued the interest of numerous academics. In this study, the scholars investigated the impact of varying water depth at the best rotating speed of discs from their earlier work (1.5 rpm) on the thermal productivity of vertical distillers. Numerous water depths (5, 8, 11, and 14 cm) were studied at 1.5 rpm to specify the best depth. The results indicated that utilizing moving discs enhanced the distillers' productivity. Besides, the peak distiller performance was obtained at 1.5 rpm and 5 cm. Furthermore, the yield of the modified single-stage vertical distiller (MSSVD) and modified double-stage vertical distiller (MDSVD) was increased by 350 and 617.4%, respectively, over the conventional tilted distiller (CTD) productivity of 2.3 L/m2 day. MSSVD and MDSVD had the highest efficacy rates of 48.4 and 77.2%. Lastly, for CTD, CVD, MSSVD, and MDSVD, the pure water cost was 0.025, 0.0477, 0.0180, and 0.0193 $/L, respectively.
Abstract Freshwater is one of the most essential needs of society. Due to the limited amount of potable water on Earth, guaranteeing the supply of clean water to society is a major challenge. By utilizing abundant sunshine, solar still could be utilized to provide the necessary amount of drinking water in remote locations. The issue of restricted daily production inspires researchers to investigate novel ways for enhancing the thermal performance of desalination techniques while lowering expenses. In this work, the scholars improved a unique distillation method related to solar stills. The authors presented a novel improvement to the vertical distiller design to enhance the exposure area while decreasing the thickness of the water layer as much as possible. Thus, two rotational discs (flat type) covered with wick were integrated into the vertical distiller basin at 1.5 rpm and 5 cm water depth. Furthermore, providing vacuum via a fan with an external condenser. Besides, various rotating speeds (from 400 to 2000 rpm) were tested to determine the perfect fan speed that provides the maximum yield. The experimental findings revealed that the modified vertical distiller produced more pure water than the conventional distiller. Moreover, the rotation of wick discs and vacuum fan enhanced the yield of distillers enormously. Besides, the highest distiller performance was obtained at 1.5 rpm (wick disc speed) and 1600 rpm (fan speed, 10 min ON, and 10 min OFF). Moreover, the daily freshwater output was 19.1 L/m2 day for MDSVD without the fan and 23.65 L/m2 day for MDSVD with the fan. So, the yield of MSSVD without/with vacuum fan was improved by 548.65% and 660.45%, respectively, over that of CTD. The best thermal efficacy for MDSVD without/with vacuum fan was 77.47% and 84.05%, respectively. Lastly, the average cost of freshwater was 0.021, 0.0177, and 0.0164 $/L for CTD, MDSVD without/with vacuum fan, respectively.
OBJECTIVE: In a pandemic, government assistance is essential to support the most vulnerable households as they face health and economic challenges. However, government assistance is effective only when it reaches vulnerable households in time. In this paper, we estimated the timeliness of government assistance for the most vulnerable households (ie, the poor households) in Ethiopia during its COVID-19 response of 2020. In particular, we conducted a time-to-event analysis to compare the time to receive government assistance between poor and non-poor households in Ethiopia. METHODS: We used a semiparametric Cox proportional model to evaluate whether the time to first receipt of government assistance during the COVID-19 response in 2020 differed between poor and non-poor Ethiopian households. We used the Schoenfeld test to check the proportionality assumption and conducted the stratified Cox regression analysis to adjust for non-proportional variables. The data from World Bank's High-Frequency Phone Surveys on COVID-19 and the 2019 Ethiopian Socioeconomic Survey were used for this analysis. RESULTS: We found that the poor households in rural areas were 88% (HR: 1.88; 95% CI: 1.19 to 2.98) more likely to receive government assistance than non-poor households at any point within 10 months after the start of the pandemic. However, there was no significant difference between urban poor and non-poor households' likelihood of receiving government assistance during this timeframe. CONCLUSION: The Ethiopian government has leveraged its existing social protection network to quickly reach poor households in rural areas during the COVID-19 response of 2020. The country will need to continue strengthening and scaling the existing social protection systems to accurately target the wider vulnerable population in urban areas.
BACKGROUND: Investing in late-stage clinical trials, trial sites, and production capacity for new health products could improve access to vaccines, therapeutics, and infectious disease diagnostics in middle-income countries. This study assesses the case for such investment in three of these countries: India, Kenya, and South Africa. METHODS: We applied investment case modelling and assessed how many cases, deaths, and disability-adjusted life years (DALYs) could be averted from the development and manufacturing of new technologies (therapeutics and vaccines) in these countries from 2021 to 2036, for five diseases—HIV, tuberculosis, malaria, pneumonia, and diarrhoeal diseases. We also estimated the economic benefits that might accrue from making these investments and we developed benefit–cost ratios for each of the three middle-income countries. Our modelling applies two investment case perspectives: a societal perspective with all costs and benefits measured at the societal level, and a country perspective to estimate how much health and economic benefit accrues to each middle-income country for every dollar invested in clinical trials and manufacturing by the middle-income country government. For each perspective, we modelled two scenarios: one that considers only domestic health and economic benefits; and one that includes regional health and economic benefits. In the regional scenarios, we assumed that new products developed and manufactured in India would benefit eight countries in south Asia, whereas new products developed and manufactured in Kenya would benefit all 21 countries in the Common Market for Eastern and Southern Africa (COMESA). We also assumed that all 16 countries in the Southern African Development Community (SADC) would benefit from products developed and manufactured in South Africa. FINDINGS: From 2021 to 2036, product development and manufacturing in Kenya could avert 4·44 million deaths and 206·27 million DALYs in the COMESA region. In South Africa, it could prevent 5·19 million deaths ...