ESTIMATION OF GLOBAL SOLAR RADIATION AT CALABAR USING TWO MODELS

In this study, the estimation of global solar radiation with Meteorological parameters at Calabar- Nigeria latitude 40N and longitude 80 E were carried out. The daily mean temperature and relative humidity for seventeen years (1991 to 2007) from Nigerian Meteorological Agency, Federal Ministry of Aviation, Oshodi, Lagos were used. The global solar radiation data were collected courtesy of Renewable Energy for Rural Industrialization and Development in Nigeria. Two models (multiple regression and artificial neural network) were used for the estimation. Comparing the graphs of correlation equation 4 and 5, and equation 6 and 7 of the first model, it is obvious that the first order correlation has better estimation power. Looking at the overview of all the Figures (1 -5A), is it is clear that the two models used in this study has estimation capacity, but Figure 5A shows better correlation with the measured values, which indicates that artificial neural network model is a better model for estimation. Therefore has been recommended for global solar radiation estimation at Calabar and its environs with similar weather condition. Alternatively, first order regression should be use for estimation in the absent of artificial neural network. Keywords: artificial neural network, regression, model, global solar radiatio

From curiosity to commodity: a review of the evolution of sachet drinking water in West Africa

The private sector continues to play an important role in filling local drinking water supply gaps across the Global South. In West Africa, a perfect storm of rapid population growth, infrastructure mismanagement, and globalization of consumer markets has resulted in the advent of an entire new industry around packaged water, primarily ‘sachet water’ sold in mechanically sealed plastic sleeves. Most local governments and international development agencies have historically perceived sachet water as a passing trend, but it has quickly become a primary drinking water source for the majority of households in many urban areas and continues to spread throughout the region and world. Sachet water is now an important component of regional water security, although with attendant issues related to governance, quality control, environmental pollution, and social justice. This paper reviews the seminal literature on sachet water in West Africa, with particular emphasis on Ghana and Nigeria, where most studies have focused. This review synthesizes governance issues, consumer and industry trends, and the latest on product quality in the literature from 2011 to 2016, with 2010 approximating an inflection point for the modernization of the industry. The ability of many West African nations to achieve universal access to safe drinking water may depend on their willingness to understand and incorporate the sachet water industry into an integrated drinking water platform. WIREs Water 2017, 4:e1206. doi: 10.1002/wat2.1206 This article is categorized under: Engineering Water > Planning Water Engineering Water > Sustainable Engineering of Water Human Water > Water Governance A typical 500‐mL sachet of drinking water sold in Accra, Ghana