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Search Results: 1 - 10 of 74 matches for " Kwasi Preko "
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Geophysical Interpretation of Possible Gold Mineralization Zones in Kyerano, South-Western Ghana Using Aeromagnetic and Radiometric Datasets  [PDF]
David Dotse Wemegah, Kwasi Preko, Reginald Mensah Noye, Benjamin Boadi, Aboagye Menyeh, Sylvester Kojo Danuor, Thomas Amenyoh
Journal of Geoscience and Environment Protection (GEP) , 2015, DOI: 10.4236/gep.2015.34008
Abstract: Airborne magnetic and radiometric datasets are used to interpret the geology and geological structural patterns which serve as potential gold mineralization zones in the Kyerano area located at south-western boundary of the prospective Sefwi Gold Belt and the Kumasi Basin in south-western Ghana. The geophysical data processing approach adopted concentrated on mapping geological boundaries, geological structures and possible gold mineralization zones is link to hydrothermally altered zones. The application of the enhancement filtering algorithms such as the reduction to the pole and analytic signal to the magnetic data, as well as the ternary radiometric image aided in the mapping of the mafic metavolcanics, basin metasediments and the belt-type granitoid complexes. The first vertical derivative and tilt angle derivative filters helped to delineate fractures, folds, and the contact zones of the formations such as that of the metavolcanics-metasediments that host the main Bibiani Shear Zone. Lineament analysis of the structures using rose diagram, reveals two main tectonic episodes in the area. These are NE-SW and NNW-SSE trending regional structures which account for about 90% of the extracted structures and are associated with the D1 and D2 deformational episodes of the Birimian Formation respectively. These structures are major fracture systems and play a pivotal role in the localization of gold mineralization in the study area.
The Spatio-Temporal Variability of Rainfall over the Agro-Ecological Zones of Ghana  [PDF]
Winifred A. Atiah, Leonard K. Amekudzi, Emmanuel Quansah, Kwasi Preko
Atmospheric and Climate Sciences (ACS) , 2019, DOI: 10.4236/acs.2019.93034
Abstract: Rainfall variability plays an important role in many socio-economic activities such as food security, livelihood and farming in Ghana. Rainfall impact studies are thus very crucial for proper management of these key sectors of the country. This paper examines the seasonal and annual rainfall variability in the four agro-ecological zones of Ghana from the CHIRPS V2 rainfall time series spanning a period of 1981-2015. The rainfall indices were computed with the aid of the FClimDex package whereas the trends of these indices were further tested using the Mann Kendall trend test. The results show good agreement (r ≥ 0.7) between CHIRPS V2 and gauge in almost all portions of country although high biases were observed especially in DJF season over parts of the Northeastern (NE) portions of the country. The mean seasonal rainfall climatology over the country is observed to be in the range of 20 - 80 mm, 60 - 200 mm, 100 - 220 mm and 40 - 180 mm in DJF, MAM, JJA and SON seasons respectively with high intensities of rainfall dominating Southwestern portions of the country. The trend analysis revealed positive trends of consecutive dry days in the Transition, Forest and Coastal zones and negative trends in the Savannah zone of the country. Decreasing trends of consecutive wet days are observed over the Savannah, Transition and Coastal zones whereas increasing trends dominate the Forest zone. Savannah, Forest and Transition zones show weak increasing trends of the number of heavy rainfall days whilst weak decreasing trends are observed over the Coastal zone of the country. Similarly, weak increasing trends of the number of very heavy rainfall days are observed over all the agro-ecological zones except in the Transition zone. It is observed that the annual wet day rainfall total has increasing trend in the Savannah and Forest zones of the country whereas decreasing trends cover the remainder of the zones. The trends of these indices in the agro-ecological zones were all significant at a significant value of 0.05. This paper assessed the performance of the CHIRPS V2 rainfall data over the region and reports on the biases in seasonal rainfall amounts which are limited in previous studies. These findings have adverse impacts on rain-fed agricultural practices, water resource management and food security over the country.
Validation of TRMM and FEWS Satellite Rainfall Estimates with Rain Gauge Measurement over Ashanti Region, Ghana  [PDF]
Leonard K. Amekudzi, Marian A. Osei, Winifred A. Atiah, Jeffrey N. A. Aryee, Maureen A. Ahiataku, Emmanuel Quansah, Kwasi Preko, Sylvester K. Danuor, Andreas H. Fink
Atmospheric and Climate Sciences (ACS) , 2016, DOI: 10.4236/acs.2016.64040
Abstract: Satellite rainfall estimates have predominantly been used for climate impact studies due to poor rain gauge network in sub-Saharan Africa. However, there are limited microscale studies within the sub-region that have assessed the performance of these satellite products, which is the focus of the present study. This paper therefore considers validation of Tropical Rainfall Measuring Mission (TRMM) and Famine Early Warning System (FEWS) satellite estimates with rain gauge measurements over Ashanti region of Ghana. First, a consistency assessment of the two gauge data products, the Automatic Rain Gauge (ARG) and Ghana Meteorological Agency (GMet) Standard Rain Gauge (SRG) measurements, was performed. This showed a very good agreement with correlation coefficient of 0.99. Secondly, satellite rainfall products from TRMM and FEWS were validated with the two gauge measurements. Validation results showed good agreement with correlation coefficients of 0.6 and 0.7 for TRMM and FEWS with SRG, and 0.87 and 0.86 for TRMM and FEWS with ARG respectively. Probability Of Detection (POD) and Volumetric Hit Index (VHI) were found to be greater than 0.9. Volumetric Critical Success Index (VCSI) was 0.9 and 0.8 for TRMM and FEWS respectively with low False Alarm Ratio (FAR) and insignificant Volumetric Miss Index (VMI). In general, relatively low biases and RMSE values were observed. The biases were less than 1.3 and 0.8 for TRMM and FEWS-RFE respectively. These indicate high rainfall detection capabilities of both satellite products. In addition, both TRMM and FEWS were able to capture the onset, peak and cessation of the rainy season, as well as the dry spells. Although TRMM and FEWS sometimes under/overestimated rainfall, they have the potential to be used for agricultural and other hydro-climatic impact studies over the region. The Dynamic-Aerosol-Cloud-Chemistry Interactions in West Africa (DACCIWA) project will provide an improved spatial gauge network database over the study area to enhance future validation and other climate impact studies.
Empirical Models for Estimating Global Solar Radiation over the Ashanti Region of Ghana
Emmanuel Quansah,Leonard K. Amekudzi,Kwasi Preko,Jeffrey Aryee,Osei R. Boakye,Dziewornu Boli,Mubarick R. Salifu
Journal of Solar Energy , 2014, DOI: 10.1155/2014/897970
Abstract: The performances of both sunshine and air temperature dependent models for the estimation of global solar radiation (GSR) over Ghana and other tropical regions were evaluated and a comparison assessment of the models was carried out using measured GSR at Owabi (6°45′0′′N, 1°43′0′′W) in the Ashanti region of Ghana. Furthermore, an empirical model which also uses sunshine hours and air temperature measurements from the study site and its environs was proposed. The results showed that all the models could predict very well the pattern of the measured monthly daily mean GSR for the entire period of the study. However, most of the selected models overestimated the measured GSR, except in April and November, where the empirical model using air temperature measurements underestimated the measured GSR. Nevertheless, a very good agreement was found between the measured radiations and the proposed models with a coefficient of determination within the range 0.88–0.96. The results revealed that the proposed models using sunshine hours and air temperature had the smallest values of MBE, MPE, and RMSE of ?0.0102, 0.0585, and 0.0338 and ?0.2973, 1.7075, and 0.9859, respectively. 1. Introduction Solar radiation is the primary source of the Earth’s energy, providing about 99.97% of the heat energy required for chemophysical processes in the atmosphere, ocean, land, and other water bodies [1]. Solar radiation plays an important role as a renewable energy source as solar radiation measurements could be used to estimate potential power levels that can be generated from photovoltaic cells and also necessary for determining cooling loads for buildings [2]. Solar radiation thus has many useful applications in architectural design, evapotranspiration estimates, agriculture, and atmospheric, land, ocean, and hydrologic models [3, 4]. The acquisition and the development of database on the long term solar radiation will facilitate the evaluation of solar energy potential as an input to the country’s energy budget and other modeling applications mentioned earlier. The development of solar technology in the country will minimise its overreliance on wood fuel consumption, estimated at 18 million tons per annum, especially in the rural communities ([5] and references therein). Studies carried out on solar irradiance measurements in some parts of the country suggest that there is a potential for solar energy to be used on commercial scale and in this vein the Ghana Grid Company (GRIDco) has begun producing electrical energy from a solar farm established in the northern part of Ghana
Interpretation of Geological Structures Hosting Potential Gold Deposits in the Konongo Gold Mine Using Airborne Magnetic, Electromagnetic and Radiometric Datasets  [PDF]
Fosu Brempong, David Dotse Wemegah, Kwasi Preko, Thomas Armah, Benjamin Boadi, Aboagye Menyeh, Isaac Amankwah Oppong, Mariam Maku Quarshie, Akwasi Acheampong Aning, Vandycke Sarpong Asare, Reginald Mensah Noye
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.76016
Abstract: The renewed interest in the reactivation of the defunct National Konongo Gold Mine located in the Ashanti Greenstone Belt, calls for a further probe into its geology and the associated mineral hosting structures to discover its mineralization potential. In order to achieve this, airborne magnetic, radiometric and electromagnetic datasets were interpreted to determine the potential gold hosting features in the studied area. The results show the area to consist of the metasediment, the metavolcanic, Tartwaian Formation and their associated granitoids. Results also show that the Tarkwaian sediments, observed largely in the north-eastern side of the site; widen out substantially and truncate in the south. The analysis of the structure lineaments using a rose diagram reveals three main tectonic structures trending in N-S, NNW-SSE, and third the structure trending in the NNE-SSW to NE-SW directions in the area. The dominant structures in the area, form 90% of all the delineated structures and trend in the NE-SW and NNE-SSW direction with the remaining 10% trending in the N-S and NNW-SSE. These structures are associated with the major shear and fracture zones located mainly at the contact between the basin sediments and volcanic belt and also associated with the Tarkwaian Formation. The mapped potential gold mineralization zones located mainly at the contact between the metasediment and the metavolcanic units of the Birimian Supergroup, as well as the Tarkwaian Formation, were mapped by integrating the structures, alteration zones as well as the complex dyke systems. This paper delineates the prominent geological structures with the potential of hosting economic gold mineralization in and around the Konongo Gold Mine.
First performance assessment of blends of jatropha, palm oil and soya bean biodiesel with kerosene as fuel for domestic purposes in rural-Ghana
Quansah E., K. Preko, L. K. Amekudzi
International Journal of Energy and Environment , 2011,
Abstract: Performance assessments of jatropha, palm oil and soya bean based biodiesel were carried out to investigate their potential use as conventional substitute for kerosene for domestic purposes in rural- Ghana. The assessments were done by comparing some of the combustion characteristics of blends of the biodiesel with kerosene. The blends were categorised as B100 (100% biodiesel), B80 (80% biodiesel and 20% kerosene), B60 (60% biodiesel and 40% kerosene), B40 (40% biodiesel and 60% kerosene), B20 (20% biodiesel and 80% kerosene) and B0 (pure kerosene). The results showed that the calorific values of the B100s were less than that of the B0 and decreasing in the order of jatropha, soya bean and palm oil. The wick wastage results for both the B100s and B0, revealed higher rates in the WTL than the BB even though the BB recorded low fuel consumption rates than the WTL for both B100s and B0. Similarly, the luminous intensity test with the B100s showed low values in WTL than the BB in a decreasing order of jatropha, soya bean and palm oil. However, B0 recorded higher luminous intensity values that were quite comparable in both WTL and BB.
Urban and Peri-Urban Agriculture in Developing Countries Studied using Remote Sensing and In Situ Methods
Kwasi Appeaning Addo
Remote Sensing , 2010, DOI: 10.3390/rs2020497
Abstract: Urban farming, practiced by about 800 million people globally, has contributed significantly to food security and food safety. The practice has sustained livelihood of the urban and peri-urban low income dwellers in developing countries for many years. Its popularity among the urban low income is largely due to lack of formal jobs and as a means of adding up to household income. There is increasing need to sustainably manage urban farming in developing nations in recent times. Population increase due to rural-urban migration and natural, coupled with infrastructure developments are competing with urban farming for available space and scarce resources such as water for irrigation. Lack of reliable data on the extent of urban/peri-urban areas being used for farming has affected developing sustainable policies to manage urban farming in Accra. Using ground based survey methods to map the urban farmlands are inherently problematic and prohibitively expensive. This has influenced accurate assessment of the future role of urban farming in enhancing food security. Remote sensing, however, allows areas being used as urban farmlands to be rapidly established at relatively low cost. This paper will review advances in the use of remote sensing technology to develop an integrated monitoring technique for urban farmlands in Accra.
An Evaluative Study of a Distance Teacher Education Program in a University in Ghana
Kwasi Addo Sampong
International Review of Research in Open and Distance Learning , 2009,
Abstract: The study used an adaptation of Provus’ discrepancy evaluation model to evaluate a distance teacher education program in the University of Cape Coast, the premier teacher education institution in Ghana. The study involved comparing performance data of the program as perceived by students and faculty/administrators to standards prepared from the program’s design. Performance data was obtained by administering two survey instruments to a random sample of students and faculty/administrators. Discrepancies between performance and standards were reported. The study concluded that although there were some discrepancies between program standards and performance the program is fulfilling its purpose of upgrading the professional and academic performance of a large number of teachers in the public K-8 schools in Ghana.
The Cultural Approach to the Management of the International Human Resource: An Analysis of Hofstede’s Cultural Dimensions
Kwasi Dartey-Baah
International Journal of Business Administration , 2013, DOI: 10.5430/ijba.v4n2p39
Abstract: The subject of culture has gained much prominence and attention in the management of international human resource. This paper examines the issues of culture, both national and organisational, reviews and discusses relevant literature and draws conclusions based on the issues at hand. The discussion of this paper is based on Hofstede’s cultural dimensions. The findings of this paper revealed that elements contained in national cultures can transcend into organizational concerns. Moreover, not only are national cultures the main determinants of the success or failure of multinational businesses, but also organisational cultures. The paper advances that in dealing with matters of culture in the international domain, the point in question is how these cultural issues are managed and not the mere existence of the same that determines the success or failures of organisations.
Evaluation of Fuel Properties of Six Tropical Hardwood Timber Species for Briquettes  [PDF]
Stephen J. Mitchual, Kwasi Frimpong-Mensah, Nicholas A. Darkwa
Journal of Sustainable Bioenergy Systems (JSBS) , 2014, DOI: 10.4236/jsbs.2014.41001
Abstract:

The fuel potential of six tropical hardwood species namely: Triplochiton scleroxylon, Ceiba pentandra, Aningeria robusta, Terminalia superba, Celtis mildbreadii and Piptadenia africana were studied. Properties studied included species density, gross calorific value, volatile matter, ash content, organic carbon and elemental composition. Fuel properties were determined using standard laboratory methods. The result indicates that the gross calorific value (GCV) of the species ranged from 20.16 to 22.22 MJ/kg and they slightly varied from each other. Additionally, the GCV of the biomass materials were higher than that of other biomass materials like; wheat straw, rice straw, maize straw and sugar cane. The ash and volatile matter content varied from 0.6075 to 5.0407%, and 75.23% to 83.70% respectively. The overall rating of the properties of the six biomass materials suggested that Piptadenia africana has the best fuel property to be used as briquettes and Aningeria robusta the worse. This study therefore suggests that a holistic assessment of a biomass material needs to be done before selecting it for fuel purpose.

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