Chapters in a book

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    Biowastes as a potential energy source in Africa
    (IntechOpen, 2021) Kazawadi, Deodatus; Ntalikwa, Justin; Kombe, Godlisten
    High population and industrialization have brought the need for a reliable and sustainable source of energy and protection of the environment. Although Africa has a low energy consumption capacity (3.4% of the global share in 2019), its high population growth rate and industrialization predict high energy demand in the future. Reliable and available energy resources are required to protect the environment and create energy dependency. Despite Africa’s low energy consumption capacity (3.4% of global consumption in 2019), its rapid population growth rate and industrialization indicate future significant energy demand. The current high production of biowastes with high energy content and their low utilization provides an opportunity for energy dependency, crop value addition, creation of jobs, and protection of the environment. The chapter has identified that the African population of 1.203 billion in 2017 consumed 928 Mtoe of energy and this demand is expected to increase in years to come. The energy mix has been identified to depend on fossil fuels with little consideration of biowastes. The biowaste is reported to contain 20.1 TWh in 2025. Biowaste is currently underutilized, and there are few conversion methods available. Government and non-government investments have been reported to be making efforts to improve bioenergy and biowaste usage. The prevailing challenges have been low proven technologies, poor energy policy, low population knowledge, and poor investments. Biowastes use can be increased when environmental laws and legislation are tightened, energy policy strengthened and enforced, cheap and appropriate technologies are introduced, and the population Education is provided. It is expected that when biowastes are well utilized, energy will be available even in disadvantaged (remote) areas at an affordable price for the developing continent of Africa.
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    Credit access by small and medium enterprises in Tanzania: a case study of Dar es Salaam city
    (OMICS Publishing Group, 2017) Magembe, Yohane
    The contribution of Small and Medium Enterprises (SME) in economic development has been recognized worldwide. The main challenge of the sector to contribute fully is a limited access to finance. This study examined the factors influencing access to credit by SMEs operators. Since the study was explorative in nature it employed survey method of which the data were thought to meet descriptive and inferential analysis. Therefore the study intended to collect data through questionnaires to 300 SMEs owners in Dar es Salaam city in Tanzania. The results of descriptive analysis which were presented in percentages showed that the major challenges that lenders encounter when lending among SMEs include; high interest charged and collateral requirement as the decisive factor for loan approval. Furthermore the main reasons for bad loans among SMEs operators in the region are credit management, high interest rate, short term repayment and poor business skills. The logistic results indicated that business information is the critical factor that largely influences credit access by SMEs in the region. The government should strategically regulate the stringent conditions and requirements posed to SMEs operators while education should be offered to SMEs operators in the region to improve their business operations.
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    A technical evaluation of performance characteristics for pump as turbine application
    (Springer, 2019) Mdee, Ombeni J.; Kimambo, Cuthbert Z. M.; Nielsen, Torbjorn K.; Kihedu, Joseph
    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. The operational parameters discussed include head, flow rate, power, efficiency, and specific speed. The number of modified pump components includes the blade angle, impeller size and tips, edges of shroud and hub plates, volute casing attached with guide vanes, and modified inlet casing rings and eye enlargement. The internal characteristics also occurred in the form of swirl flow between blades and discharge part, time dependent on flow circulation, radial and axial thrust, blade angle variation, pressure pulsation, cavitation effects, and energy losses between blades, volute casing, and discharge part. Furthermore, the conversion methods discussed were related to pump efficiency, specific speed and constant values to predict the head and flow rate. The conversion methods are mostly used to select the off-the-shelf pumps to run as turbine. Therefore, this paper provides the technological development of running the pump in reverse mode that would give insights for further studies in the four knowledge areas that include operational parameter characteristic, pump component modification, internal flow characteristics at the full- and part-load conditions, and also the development of conversion methods related to pump geometry, fluid properties, performance and system curves to improve the off-the-shelf pump selection.