Access to clean drinking water is a global concern. Notably, over one billion people in developing countries out of a total global population of approximately eight billion encounter challenges in accessing safe water. Photocatalytic technology is a potential solution for providing safe drinking water to these communities. However, only a few photocatalytic technologies are currently available. Although the potentialities of the photocatalytic treatment of water pollutants can be demonstrated in the laboratory, several factors hinder its effectiveness in real environmental applications. Additionally, the development of maintenance-free photocatalytic systems that can operate continuously without requiring complex maintenance is limited. Developing countries are unlikely to implement a system if it cannot be used sustainably without complex and/or frequent adjustments, regardless of the advanced technology. This principle is the fundamental premise of this review. This review in which are discusses the conditions necessary for photocatalytic water purification systems to be accepted in developing countries and explores how these systems can be successfully implemented.
The Himalayan region, known as the water tower of the Asian continent, boasts plenty of water. However, it faces acute water scarcity, particularly during the dry months from February to June. Traditional water sources were once the primary source of water in rural areas, but many have dried up, and some have vanished entirely. This paper examines potential of water resource and its conservation through traditional water practices in the Indian Central Himalaya. The study employs mainly a qualitative approach, collecting data from both primary and secondary sources. Primary data were gathered from 34 natural springs, including Naula, Dhara, streams/rivulets, Guls, and Khal-Chals, through a case study of 10 villages in the Pindar Valley. Furthermore, the characteristics and uses of these natural springs were illustrated. A total of 120 heads of households were interviewed about the status of water and its future potential, addressing perceptions of water availability, usage patterns, and water scarcity. The perception of these heads of households on the impact of climate change was noted. The author studied toposheets of the Survey of India and described the major rivers of the 13 districts of Uttarakhand. Data were also collected from the review of literature and the state water resource department, Dehradun. The study revealed that rural areas face acute water scarcity due to the drying of natural water sources. The tap water supply is insufficient, and during the rainy season, these pipelines are often damaged by flash floods and landslides. Large-scale sedimentation in the source area of tap water further hinders the water supply. The study suggests that reviving traditional natural water sources will help sustain water availability and supply.
Hard, brittle and difficult-to-machine materials are prone to surface cracks, subsurface damage and other defects in the traditional grinding process, accompanied by low processing efficiency and severe tool wear. As a new type of processing technology, energy field-assisted grinding provides a new approach for the efficient and high-quality processing of hard and brittle materials. This paper reviews the latest research progress of muti-energy field-assisted grinding from aspects such as the types and selection of grinding tools, processing equipment and physical-chemical coupled mechanisms. Firstly, micro-grinding tools are classified based on different surface structures and coating materials, with the aim to enhance processing efficiency, improve the surface quality and geometric accuracy of workpieces, and reduce tool wear. Secondly, the processing mechanisms, parameter selection and current difficulties faced by four energy field-assisted grinding methods, including laser-assisted grinding, electrochemical-assisted grinding, magnetic-assisted grinding and ultrasonic field-assisted grinding, are discussed under both chemical and physical effects. Thirdly, different equipment and auxiliary devices developed for energy field-assisted grinding have been introduced, providing reliable platforms for the distribution design and efficient regulation of the energy field. Finally, the cutting-edge progress, main challenges and development trends of energy field-assisted grinding are prospected, illustrating the great potential of this technology in fields such as aerospace, electronics, and optical components.
Global catastrophic infrastructure loss (GCIL) would disrupt energy supply networks, prohibiting heating in houses reliant on electricity or piped natural gas. In such situations, buildings in cold climates would require alternative heating methods, as space heating is critical to survival. This work assesses the viability of converting household appliances to wood-burning stoves and the scalability of such conversions in the event of a catastrophe. A standard residential electrical oven was converted to a wood-burning stove, using tools and materials likely to be readily available following GCIL, and tested by burning a total of 9.1 kg of pine wood and kindling. The conversion was successful, with an average useful heat output of 2.6 kW, showing the viability of ovens as wood-burning stoves for space heating. It is expected that such conversions could be completed in under one day, given sufficient availability of tools, materials, and labour. Global supplies of ovens, tools, materials, and fuel are expected to be sufficient for widespread conversion of ovens to wood-burning stoves, assuming international collaboration. However, international collaboration may be limited following GCIL, so countries should develop individual response plans accounting for this limitation, and knowledge should be disseminated ahead of time, or backup communication systems put in place.
A policy choice between migration prevention and migration support during climate variability needs to be properly backed by empirical evidence. The paper was to assess the effects of temporary migration on household adaptive capacity to climate variability (e.g., drought) in rural India. The analysis was performed by applying the propensity score matching method to the India Human Development Survey, 2011–12 data, and the India Meteorological Department’s gridded binary files. The household adaptive capacity to climate variability was measured in terms of three variables: monthly per capita consumption expenditure, livelihood diversity and the share of non-agricultural income. The study found that temporary migration had no statistically significant effect on household expenditure levels. The effect of temporary migration on livelihood diversity was found to be positive at 10% level of significance. The results suggest that temporary migration has significantly contributed to increasing the share of non-agricultural income. Results were similar even after removing the households with long-term migrant members from both treated and control groups. A disaggregated analysis across the different expenditure quintiles and social groups highlighted that the improved benefits of temporary migration, especially in terms of the share of non-agricultural income, were concentrated in certain groups only. The above results suggest that temporary migration may contribute to the development of household adaptive capacity in the face of climate variability (e.g., drought) not through the channel of utility maximization, but rather as a risk diversification strategy.
