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Wa, Ghana

The Wa Polytechnic is a public tertiary institution in the Upper West Region of Ghana. Wikipedia.


Adeloye A.J.,Heriot - Watt University | Rustum R.,University of Dammam | Kariyama I.D.,Wa Polytechnic
Water Resources Research | Year: 2011

Reference crop evapotranspiration (ET o) estimation is of importance in irrigation water management for the calculation of crop water requirements and its scheduling, in rainfall-runoff modeling and in numerous other water resources studies. Due to its importance, several direct and indirect methods have been employed to determine the reference crop evapotranspiration but success has been limited because the direct measurement methods lack in precision and accuracy due to scale issues and other problems, while some of the more accurate indirect methods, e.g., the Penman-Monteith benchmark model, are time-consuming and require weather input data that are not routinely monitored. This paper has used the Kohonen self-organizing map (KSOM), unsupervised artificial neural networks, to predict the ET o. based on observed daily weather data at two climatically diverse basins: a small experimental catchment in temperate Edinburgh, UK and a semiarid lake basin in Udaipur, India. This was achieved by using the powerful clustering capability of the KSOM to analyze the multidimensional data array comprising the estimated ET o (based on the Food and Agricultural Organization (FAO) Penman-Monteith model) and different subsets of climatic variables known to affect it. The findings indicate that the KSOM-based ET o estimates even with fewer input variables were in good agreement with those obtained using the conventional FAO Penman-Monteith formulation employing the full complement of weather data at the two locations. More crucially, the KSOM-based estimates were also found to be significantly superior to those estimated using currently recommended empirical ET o methods for data scarce situations such as those in developing countries. Copyright 2011 by the American Geophysical Union. Source


Dansieh S.A.,Wa Polytechnic
Journal of Pragmatics | Year: 2011

One area that cannot be overlooked when it comes to translating from a foreign language into an African language is its morphology. In this paper, we discuss one of the most pervasive morphological phenomena in African languages - reduplication. The article seeks to examine which structures in English are translatable as reduplicates in Dagaare, a Gur language of West Africa. It is an attempt at departing from the conventional morphosyntactic perspective to a pragmatic/translation perspective. Basically, we consider reduplication as a morphological process with certain grammatical functions such as plurarity, intensification, iteration and augmentation. As instances of reduplication from actual translations into Dagaare from English are examined, attention will be paid to a possible difference between uses of reduplication that have become grammaticalised so that the meaning is not modified in context; and uses which may be said to convey some general procedural information to be developed further by means of inferential processing, for instance, some heightened value of some quality or quantity or event referred to. The analysis will be done within the framework of Sperber and Wilson's relevance theory of communication. It is hoped this research will help shed more light on this interestingly pervasive but inadequately researched area of Pragmatics. © 2010 Elsevier B.V. Source


Bangoura M.L.,Jiangnan University | Bangoura M.L.,University of Gamal Abdel Nasser of Conakry | Nsor-Atindana J.,Jiangnan University | Nsor-Atindana J.,Wa Polytechnic | Ming Z.H.,Jiangnan University
Food Chemistry | Year: 2013

In this study, water and 80% of four organic solvents were employed to optimize the extraction of antioxidants from two species of foxtail millet's insoluble fibers under the same temperature, time, and solid/solvent ratio. The results showed that the acetone was able to extract the maximum amount of antioxidants (2.32 mg/g fiber for white specie and 3.86 mg/g fiber for yellow specie) followed by methanol and propanol from both samples. The neutral and the ethanol on the other hand extracted small amount of the antioxidants from the two fiber materials. While considerable level of Total Polyphenols Content (TPC) was recorded in both the water and the organic solvents' extracts, only traces of Total Flavonoid content (TFC) were observed in water, methanol and ethanol extracts. Propanol and acetone extracts was negative to the TFC test. The potency of both white and yellow foxtail millets' insoluble fibers antioxidant extracts was investigated using five different in vitro tests. It was realized that there was a variation in their capacities to quench DPPH and ABTS' + radicals for the time running of 0-60 min. The samples from the yellow cereal exhibited high inhibition capacity against ABTS'+. No correlation was observed between TPC and radical scavenging capacities for DPPH and ABTS'+. In general, the yellow species contained more antioxidants in comparison with the white one and this accounted for its high antioxidant activity. © 2013 Elsevier Ltd. All rights reserved. Source


Adeloye A.J.,Heriot - Watt University | Rustum R.,University of Dammam | Kariyama I.D.,Wa Polytechnic
Environmental Modelling and Software | Year: 2012

Reference crop evapotranspiration (ET o) estimation is of importance in irrigation water management for the calculation of crop water requirements and its scheduling, in rainfall-runoff modeling and in numerous other water resources studies. Due to its importance, several direct and indirect methods have been employed to determine the reference crop evapotranspiration but success has been limited because the direct measurement methods lack in precision and accuracy due to scale issues and other problems, while some of the more accurate indirect methods, e.g. the Penman-Monteith benchmark model, are extremely non-linear and require weather input data that are not routinely monitored. In such situations, artificial intelligence (AI), neural computing techniques that are able to accurately map complex, non-linear input-output relationships offer a useful alternative. This paper has used the Kohonen Self-Organizing Map (SOM), unsupervised artificial neural networks, to develop prediction models for the ET o. This was achieved by using the powerful clustering capability of the SOM to analyze the multi-dimensional data array comprising the estimated ET o (based on the FAO Penman-Monteith model) and different subsets of climatic variables known to affect it. The findings indicate that the SOM-based ET o estimates, even when forced with fewer input data variables, were in good agreement with those obtained using the conventional FAO Penman-Monteith formulation employing the full complement of weather data. Further comparisons were carried out between the SOM model estimates of the ET o and those based on the use of feed-forward back propagation supervised artificial neural networks and the results showed that the SOM estimates were superior. Finally, the SOM-based estimates were also found to be significantly superior to those estimated using established empirical ET o methods recommended in the literature for situations where the full complement of input weather needed to drive the Penman-Monteith model are unavailable. This offers significant potential for more accurate estimation of the ET o in data scarce regions of the world. © 2011 Elsevier Ltd. Source


Ofori-Boateng K.,Ghana Institute of Management and Public Administration | Insah B.,Wa Polytechnic
International Journal of Climate Change Strategies and Management | Year: 2014

Purpose – The study aimed at examining the current and future impact of climate change on cocoa production in West Africa. Design/methodology/approach – A translog production function based on crop yield response framework was used. A panel model was estimated using data drawn from cocoa-producing countries in West Africa. An in-sample simulation was used to determine the predictive power of the model. In addition, an out-sample simulation revealed the effect of future trends of temperature and precipitation on cocoa output. Findings – Temperature and precipitation play a considerable role in cocoa production in West Africa. It was established that extreme temperature adversely affected cocoa output in the sub-region. Furthermore, increasing temperature and declining precipitation trends will reduce cocoa output in the future. Practical implications – An important implication of this study is the recognition that lagging effects are the determinants of cocoa output and not coincident effects. This finds support from the agronomic point of view considering the gestation period of the cocoa crop. Originality/value – Although several studies have been carried out in this area, this study modeled and estimated the interacting effects of factors that influence cocoa production. This is closer to reality, as climatic factors and agricultural inputs combine to yield output. © Emerald Group Publishing Limited. Source

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