Research Interests:
The rapid growth of socioeconomic activities brings the overpressure to the water sources in the semi-arid areas. This paper identifies potential sites for surface runoff harvesting from seasonal rainfall. The potential sites were... more
The rapid growth of socioeconomic activities brings the overpressure to the water sources in the semi-arid areas. This paper identifies potential sites for surface runoff harvesting from seasonal rainfall. The potential sites were determined using the analytic hierarchy process (AHP) and weighted linear combination (WLC) techniques with four parameters including runoff depth, drainage density, slope, and lineament density under the GIS environment. The runoff depth was estimated using the Soil Conservation Service method with the three factors such as land use, rainfall, and soil parameters. The normalized weights obtained from the AHP technique were multiplied with the individual weights for each parameter using the WLC technique to acquire the weighted classes (WCs) for defining suitable for surface runoff harvesting. The covered area of about 5.5% for a very high suitable site was obtained followed by 76.4% of the highly suitable site with the WC ranged from 433 to 500% and 372 to 433%, respectively. The covered area of about 18.1% for the medium to a very low suitable site for harvesting surface runoff with the WC between 271 and 372%. The developed potential site map would provide access for harvesting the surface runoff to improve the water shortage during long dry periods, minimize flooding, or reduce the land use across the drainage network in the semi-arid areas.
Research Interests:
Research Interests:
Research Interests:
In many parts of the world, artisanal and small-scale gold mines (ASGM) employed numbers of people compared to large-scale mines. The ASGM has been played a crucial role in poverty alleviation and rural development, particularly in... more
In many parts of the world, artisanal and small-scale gold mines (ASGM) employed numbers of people compared to large-scale mines. The ASGM has been played a crucial role in poverty alleviation and rural development, particularly in developing countries. The mined ore is crushed and ground for beneficiation of gold. The grinding process involved the size reduction of blasted materials to acquire minerals of interest. This paper presents the size distribution of hand-crushed for blasted materials using sieve analysis and digital image processing. The sieve test results for hand-crushed blasted material of three muck-piles were ranged between 17 mm and 36 mm that is equivalent to 20% and 80% passings respectively, with an average of 26 mm. The digital image processing results were about 19.8 mm for 20% passing and 58 mm for 80% passing, with an average of 36.06 mm. The hand-crushed provided a wide range of material distribution than the required size in the grinding unit and increased ...
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This study uses a mass balance model and economic analysis technique to present an estimation of roofing areas and storage tank capacity for Rainwater Harvesting (RWH) system. The water-saved benefits were estimated using the monthly... more
This study uses a mass balance model and economic analysis technique to present an estimation of roofing areas and storage tank capacity for Rainwater Harvesting (RWH) system. The water-saved benefits were estimated using the monthly rainfall of over 39 years from 1981 to 2020 and five roofing areas. The proposed roof-storage-ratio method presents the minimum requirement of roof area and storage tank size when the ratio value is closer to 1. The benefit-cost ratio and percentage of reliability indicated the optimal roofing areas ranging between 200 and 300 m2 for storage tank capacity between 20 and 25 m3, with a minimum discount rate of 5%. The increased capacity of storage tank and roofing area would also be a potential factor to increase the investment cost for installing the RWH system.
Research Interests:
Different performance characteristics have been indicated when running centrifugal pumps in the reverse direction. The water flows from the discharge side of the pump to the suction side to run in the reverse direction and generate the... more
Different performance characteristics have been indicated when running centrifugal pumps in the reverse direction. The water flows from the discharge side of the pump to the suction side to run in the reverse direction and generate the mechanical rotational energy for the micro-hydropower plant. The current study evaluates the extent of variation of performance characteristics predicted by several experimental data from different pump-specific speeds and conversion methods. The performance characteristics discussed include the head, flow rate, efficiency and specific speed. The flow rate and head of a pump operating in pump mode divided with the characteristic of the pump operating in the reverse mode, at the best efficiency point, the resulting coefficient of determination (R 2 ) values were of 0.890 and 0.708, respectively. Also, the graph of head versus flow rate coefficients, which is a second- order polynomial function, has shown the value of R 2 of 0.954 for pump-specific spee...
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This work part of a PhD Study Programme at the University of Dar es Salaam, Tanzania and Norwegian University of Science and Technology, Trondheim, Norway.
Research Interests:
The rapid growth of socioeconomic activities brings the overpressure to the water sources in the semi-arid areas. This paper identifies potential sites for surface runoff harvesting from seasonal rainfall. The potential sites were... more
The rapid growth of socioeconomic activities brings the overpressure to the water sources in the semi-arid areas. This paper identifies potential sites for surface runoff harvesting from seasonal rainfall. The potential sites were determined using the analytic hierarchy process (AHP) and weighted linear combination (WLC) techniques with four parameters including runoff depth, drainage density, slope, and lineament density under the GIS environment. The runoff depth was estimated using the Soil Conservation Service method with the three factors such as land use, rainfall, and soil parameters. The normalized weights obtained from the AHP technique were multiplied with the individual weights for each parameter using the WLC technique to acquire the weighted classes (WCs) for defining suitable for surface runoff harvesting. The covered area of about 5.5% for a very high suitable site was obtained followed by 76.4% of the highly suitable site with the WC ranged from 433 to 500% and 372 to 433%, respectively. The covered area of about 18.1% for the medium to a very low suitable site for harvesting surface runoff with the WC between 271 and 372%. The developed potential site map would provide access for harvesting the surface runoff to improve the water shortage during long dry periods, minimize flooding, or reduce the land use across the drainage network in the semi-arid areas.
Research Interests:
It is very important to gain a better understanding of pump series of different specific speeds when running in reverse mode. The pump is running in reverse mode to serve as turbine for mechanical rotational energy generation in the... more
It is very important to gain a better understanding of pump series of different specific speeds when running in reverse mode. The pump is running in reverse mode to serve as turbine for mechanical rotational energy generation in the hydropower and processing plants. This review chapter employs a technical analysis as a tool to evaluate pump when running in reverse mode by assessing the technological development gathered from the literature.
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Head and flow rate are the important parameters for proper selection of centrifugal pump. However, the reversed operation of centrifugal pump leads to the off-design characteristic of head and flow rate. This paper presents an analytical... more
Head and flow rate are the important parameters for proper selection of centrifugal pump. However, the reversed operation of centrifugal pump leads to the off-design characteristic of head and flow rate. This paper presents an analytical model developed by using the system curves and velocity relations derived from pump application. Also, the differential technique is applied to the analytical model to develop the off-design characteristics of head ratio and flow rate ratio relations. The off-design characteristic relations were compared with literature and available conversion methods. Then, the analytical model coefficient (AMC) with the range between −4 and +4 was developed from the off-design characteristics of head ratio and flow rate ratio relations. The AMC value was equal to 1 when the pump operates in turbine mode and pump mode at the pump best efficiency point (BEP) and extended to either side up to ±4 when tested with literature data. Therefore, the analytical model consi...
Research Interests:
Research Interests:
The hydropower resources have become an attractive means of generating electricity to the off-grid network, especially in rural areas. This article assesses the small, mini and large hydropower resources and identified to reach 5.3 GW for... more
The hydropower resources have become an attractive means of generating electricity to the off-grid network, especially in rural areas. This article assesses the small, mini and large hydropower resources and identified to reach 5.3 GW for electricity generation in Tanzania. The technology development discussed comprises of hydro turbine manufacturers, classification and turbine selection. The barriers presented include the presence of sediment in the hydropower reservoirs, financial viability, policy and regulatory issues related to hydropower development. This reviewed article serves the investors and policymakers to understand the status of hydropower resources in Tanzania.