Spatial epidemiology of urban health risks in select West African cities

West African cities face critical societal challenges that are linked to environmental and health changes. These challenges are further exacerbated by urbanization dynamics, climate change, socio-economic mutation and lack of capacity for sustainable urban development, governance and basic services delivery. The deficiency of environmental sanitation and ecosystem services have led to high complexity of urban health risks inequalities, resulting in the need for more research on efficient urban health policies. The purpose of this contribution is to present the main findings on the spatial epidemiology of diarrhaea and malaria, and their associated risks factors in the following select West African cities. Spatial variability of exposure to diarrhaea and malaria transmission is linked to several health risks such as lack of access to water and sanitation, solid wastes management, urban flooding

Remittances: A loan funds for rural economy? Evidence from the Kayes District (Western Mali)

peer reviewedIn addition to have a direct and positive impact on reducing of food insecurity and poverty gaps in more vulnerable countries to shocks on the rainfall, the remittances received by the migrants families also allow them to have saving. This is what reveals the self-managed village banks of Kayes’ region, the most important emigration basin of Mali and located in strong climate variations area. However, this saving contributes less at agricultural sector finance

Mapping Rift Valley fever and malaria risk over West Africa using climatic indicators

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Increased PV Soiling from High Module Voltages

Natural soiling has reduced the energy output of PV systems since the technology was first used, and viable mitigation strategies have remained elusive ever since. With the ever-increasing deployments around the world, especially in dusty environments, soiling is becoming a billion-dollar problem, worldwide. Furthermore, as plant operators continue to look for ways to increase revenue, the PV operating voltages have increased to between 1000 V and 1500 V when the sun is shining. This has resulted in some unforeseen consequences nominally combined into what is termed Potential Induced Degradation.1 Recent work by Jiang et. al., 2 at NREL using Atomic Force Microscopy has demonstrated that these large potentials also affect soiling by substantially increasing the attraction of dust to the surface, but also by increasing the adhesion force. Jiang et. al.,have also shown that these higher soiling attraction and adhesion forces continue long into the night when the PV is no longer producing power. In this paper, we present a set of field results that demonstrate enhanced soiling rates that is due to the strong electric fields induced by these high voltage PV arrays. This includes observation of enhanced soiling rates measured in the field when amodule is held at ±1000 V. This is critical information for installation operators because soiling losses may be higher on some panels than what is measured by typical soiling stations, and because the high voltages are not uniform across an array, some modules may have more soiling than others, leading to potential issues with non-uniform soiling problems at the array level. We presentthis set of compelling electric field induced soiling results in this paper

A High-temperature, High-efficiency Solar Thermoelectric Generator Prototype

AbstractSolar thermoelectric generators (STEGs) have the potential to convert solar energy at greater than 15% efficiency. This project investigates the system design, the necessary thermoelectric and optical technologies, and the economic feasibility of the STEG approach. A STEG is a solid-state heat engine that converts sunlight directly into DC electricity through the thermoelectric effect. STEGs consist of three subsystems: the solar absorber, the thermoelectric generator (TEG), and the heat management system (insulation, heat exchanger, vacuum enclosure, etc.). This project will integrate several state-of-the-art technologies to achieve high efficiency, including next- generation materials for TEGs, high-temperature solar-selective absorbers, and thermal cavities. We will test STEGs at NREL's high flux solar furnace (HFSF) and perform analysis of parasitic losses and lifetime analysis to optimize prototype operation. Equally important for this technology is the development of a cost model to determine the economic competitiveness and possible application niches for STEG technologies. We report on first-order economic analysis to identify the most promising pathways for advancing the technology