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Drivers, Impacts and Mitigation of Increased Sedimentation in the Hydropower Reservoirs of East Africa
Get PDFThis research article was MPDI, 2021Hydropower reservoirs are essential for the climate-neutral development of East Africa.
Hydropower production, however, is threatened by human activities that lead to a decrease in water
storage capacity of reservoirs. Land use/land cover and climatic changes are driving accelerated soil
erosion in semi-arid East Africa, which ultimately increases reservoir sedimentation and decreases
energy production. Sediment delivery dynamics at the catchment scale are complex, involving the
interaction of multiple factors and processes on different spatial and temporal scales. A lack of under standing of these processes and their interactions may impede the efficiency of sediment mitigation
and control strategies. A deep understanding of the processes of erosion and connectivity of the
land to river channel, as well as storage of eroded material within hillslopes and floodplains, and
sediment accumulation in the reservoirs supports selection of future dam locations and sustainable
management of reservoirs. The sediment budget approach can provide such a holistic perspective by
accounting for the various sediment sources, transport, sinks, and redistribution when the sediment
is routed through that catchment. Constructing sediment budgets is challenging, but the potential
for integrating a number of different techniques offers new opportunities to collect the required
information. In East Africa, the spatial planning of dams is mainly dominated by political and
financial motives, and impacts of land use and climate on the sediment transport dynamics are not
adequately considered. Production of sediment budgets under different scenarios of land use and
climate change should be an essential step when deciding the location and management strategies
for dams. Selection of new hydroelectric reservoir sites must consider long-term scientific data on
climate change, and the sediment budget components for sustainable land management planning,
hydropower sustainability
Production of carbonized briquettes from charcoal fines using African Elemi (Canarium Schweinfurthii) resin as an organic binder
Get PDFThis research article was published by Taylor & Francis Group, 2021This study investigated the use of African Elemi (Canarium Schweinfurthii) resin as a binder for the production of carbonized briquettes from charcoal fines. The binder and charcoal fines were characterized through proximate analysis, ultimate analysis, higher heating value, and SEM. Four briquette samples (B25, B30, B35, and B40) with a ratio of charcoal fines: binder of 3:1, 7:3, 13:7, and 3:2, respectively, were produced at a compaction pressure of 5.92–7.96 MPa. The physical properties of the briquettes determined were bulk density, impact resistance index (IRI), compressive strength, splitting tensile strength, water resistance index (WRI), and morphology. The chemical properties of the briquettes determined were proximate analysis, ultimate analysis, higher heating value (HHV), and energy density. One-way ANOVA and Fisher’s LSD were used to analyze the chemical properties of briquettes. The briquettes had a bulk density of 0.770–1.036 g/cm3, IRI of 2.90–73.33, compressive strength of 2.25–10.94 N/mm2, splitting tensile strength of 0.09–0.42 N/mm2, WRI of 99.26–99.29, and an HHV of 29.7–31.3 MJ/kg. The briquette properties were found to be comparable to results from other studies.This research article was published by Taylor & Francis Grou
Mathematical Modelling of Drug Abuse and it’s Effect in the Society
Get PDFThis research article was published in the Annals of Pure and Applied Mathematics, 202
A quantification model against tuta absoluta effects on tomato plants: a computer vision approach
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Information and Communication Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyTomatoes are among the most commonly cultivated crops in the world. It is considered a high value crop and income resource for smallholder farmers in Africa. Nevertheless, its production
currently endangered by Tuta absoluta pest. The pest has severely damaged tomato yields to
the extent that growers are giving up tomato production due to the high costs and losses
incurred. It causes a heavy loss in tomato produce ranging from 80 to 100% when not
effectively managed. Recently, farmers have been using different methods in efforts to control
the pest. These include using pheromone traps and natural enemies for population monitoring,
planting resistant tomato varieties, and continuous spraying of chemical pesticides, which is
now the main control method. These practices have been proven not to be effective in
controlling the pest; they are time-consuming and relatively expensive. Inspired by the
progression and positive outcomes of computer vision methods in diagnosing a wide variety of
plant diseases and pests, this study proposes a segmentation-based quantification model for
detecting and quantifying Tuta absoluta’s damage to tomato plants. We develop convolutional
neural network models based on U-Net and Mask RCNN architectures for automatic semantic
and instance segmentation respectively using data collected from the field. Experimental
results show that Mask RCNN achieved a mAP of 85.67% and U-Net obtained 78.60% and
82.86% of Jaccard index and Dice Coefficient respectively. Both models were precise in
segmenting the shapes of Tuta absoluta-infected areas in tomato leaves and determine their
extent of the damage. The model was then deployed on the mobile phone to enable farmers and
extension officers in Tanzania to automatically detect affected areas on tomato plants and make
informed decisions on how to control the pest so as to increase tomato production and save
farmers from the losses they face
Mobile application development for university students management system: the case of Pwani University in Kenya
Get PDFA Project Report Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Science in Embedded and Mobile Systems of the Nelson Mandela African Institution of Science and TechnologyUniversities in Kenya have demonstrated a great increase of mobile gadget users to access
university-related information. In Pwani University, the Information Management System is
currently accessible through a local area network connection on laptops and desktop computers,
which are fixed in offices. In addition, the working hours of the office between Monday to Friday
limit access to services to many students especially those who are out of the main campus. The
objective of this project is to develop a mobile application and integrate it with the existing
university Information Management System for improving access and user experience for services
to be accessed anytime, anywhere through connected smartphones. An online survey, interviews,
and observations to collect the system requirements were gathered and analyzed essential
requirements for the design and development of the mobile application. Agile software
methodology was used because of its flexibility to accommodate changes. The integration
architecture was based on Representational state transfer (RESTful) Application Programming
Interface. The System Usability Scale methodology assessed the user's perception and usefulness
of the mobile application. The developed mobile app successfully connected with the current
system. Unit, integration, and system testing were performed to ensure the intended specifications
were met. The key findings from the survey show that smartphones, are the most owned and used
mobile devices among students and staff. The majority of students 97% agreed that the justification
for developing the app was valid. The study indicated that 68% of students want access to course
information, fees balance, and their profile via their mobile gadgets. The usability and acceptance
testing were successful with 90% of users liking the app and 80% did not need any assistance to
use the app and did not find it cumbersome. Universities can provide seamless services by
integrating their current management systems with mobile apps and this research contributes to the
knowledge on mobile app design, usability, and acceptance testing
Tree species diversity, composition and structure across human impacted and non-impacted areas in upgraded Marang’ Forest, Northern Tanzania
Get PDFThis research was published by INNSPUB, 2021Globally, forests’ capacity to provide ecological services and support human life is rapidly declining due to the lack of deployment of proper resource management approaches. Countries adopt a wide range of management regimes that vary in degree of effectiveness in controlling unstainable human activities. This study aimed at understanding the impacts of upgrading the protection status of forested areas to a higher International Union for Conservation of Nature (IUCN) categories on tree species diversity, composition, and structure. The study explored Marang’ Forest (MF), annexed into Lake Manyara National Park a decade ago after being strongly impacted by mining and other human activities. It uses concentric circular plots to identify tree species, count stems, measure tree diameter at breast height, and assess indicators of disturbances in human-impacted and non-impacted areas. Results show a lower degree of human disturbances, including wood extraction, mining, livestock grazing, and trespassing has deterred in the forest. Tree species richness was about one third, and the Shannon’s diversity index was 17% higher, in impacted than non-impacted areas (t = 5.03, df = 34, P <0.001 and t = 4.98, df = 34, P < 0.001, respectively). The average number of tree stems ha-1 was 640 ± 26 significantly higher in impacted areas than non-impacted areas (524 ± 22; t = 3.46, df = 34, P = 0.01). It shows that lowering human disturbances by upgrading forests reserve to higher protected status enhance forest recovery and improve tree species diversity, composition, and structure
Modelling the Control of the Impact of Fall Armyworm (Spodoptera frugiperda) Infestations on Maize Production
Get PDFThis research article published by Hindawi, 2021In this paper, we propose and analyze a stage-structured mathematical model for modelling the control of the impact of Fall Armyworm infestations on maize production. Preliminary analysis of the model in the vegetative and reproductive stages revealed that the two systems had a unique and positively bounded solution for all time . Numerical analysis of the model in both stages under two different cases was also considered: Case 1: different number of the adult moths in the field assumed at and Case 2: the existence of exogenous factors that lead to the immigration of adult moths in the field at time . The results indicate that the destruction of maize biomass which is accompanied by a decrease in maize plants to an average of 160 and 142 in the vegetative and reproductive stages, respectively, was observed to be higher in Case 2 than in Case 1 due to subsequent increase in egg production and density of the caterpillars in first few (10) days after immigration. This severe effect on maize plants caused by the unprecedented number of the pests influenced the extension of the model in both stages to include controls such as pesticides and harvesting. The results further show that the pest was significantly suppressed, resulting in an increase in maize plants to an average of 467 and 443 in vegetative and reproductive stages, respectively
Characterization of land use influence on soil phosphate bioavailability in Usangu agro-ecosystem-Tanzania
Get PDFThis research article published by Elsevier B.V., 2021Phosphorus (P) is an important nutrient required for plant growth. Land use influences concentration and bioavailability of P in agricultural soils. About 198 soil samples (0-30 cm soil depth) were collected from three land-use types (maize, paddy, and conserved areas) in Usangu basin located in Southern Highland Tanzania. The concentration of soil P determined were compared among different land-use types and locations. The total P (TP), complexed (Po), and bioavailable P (B-P) were measured. The concentration of TP and B-P was determined by acid digestion and Mehlich 3 method, respectivelly, The Po concentration in soil extract was obtained by subtracting B-P from TP. TP, B-P and Po concentration in collected soils samples were in range of; Total P (63.12-1350.9 mg/kg), Bioavailable P (0.52-49.87 mg/kg), and complexed P (62.60-1301.03 mg/kg). The cropping area had high TP but very low B-P, especially in paddy farming areas indicating cropping and associated activity decrease bioavailable P in agricultural soils. Furthermore, soils from cropping areas had higher Al, Fe, and Mg concentrations than conserved areas, which caused a substantial reduction in B-P due to increased P fixation and adsorption. It is important to note that converting natural land to farming land could potentially influence soil P dynamics thus affecting P bioavailability, crop productivity, and environmental safety
Development of a mobile application system for raha beverages company limited management communication at different levels
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master of Science in Embedded and Mobile Systems of the Nelson Mandela African
Institution of Science and TechnologyThe existing forms of communication at Raha Beverages Company Ltd are not effective
enough hence bringing about the demand for an effective communication system in the
company. The Raha Application is a system that supports internal communication across all
levels of the company. As the company expands through the means of strategic planning in a
certain time frame, these transitions bring about change in the company structure as well as
processes ranging from production, transportation, the workforce to communication which
runs in parallel. Forms and methods of data collection described involved were interviews,
observations, document analysis, joint application design, brainstorming and prototyping.
Interview and observation were the main used forms. This system was implemented using
agile software development, which defines software development from program
specification, design, implementation, and testing which are interleaved that support frequent
delivery of new versions for evaluation. The mobile application is designed for internal
communications at different levels among employees. Each employee will have to be given
initial login credentials to enable first-time login but will be recommended to change the
credentials once logged in according to their preferences. The mobile application system
developed was tested and evaluated to assess its usability for effective communication. The
system provided benefits like better management control, better decision making, improved
efficiency in communication, a faster way of reporting, easy access and availability of
information. Therefore, this study presents a mobile application system solution that will
support sustainability in communication throughout the entire company for effective
company communicatio
Brix and Alcohol Content Monitoring using Wireless Sensor Network
Get PDFThis research article published by International Journal of Advances in Scientific Research and Engineering, Volume 7, Issue 7, 2021Fermentation process plays an important role in the production of wine and beer, as these ferments convert Brix (sugar) into alcohol. Thus fermentation plays a key role in beer production hence monitoring entire activities is essential to breweries. As such, this project aimed to monitor the by-products of fermentation processes which are Brix (Sugar concentration) and Alcohol in order to improve the Quality of alcohol. Different stages of fermentation produce different Brix and alcohol percentages by volume. A system using wireless communication protocol is proposed where sensor node readings are transferred to a centralized station for monitoring and visualization. The sampling technique used was Non-probability purposive due to the fact that information gathered was important to contribute to better understand the problem by gathering information from the right personnel in the field of study. Through this approach, it is a perfect application of IoT and Wireless Sensor Network solution which has been achieved and provides advantages to the brewery industry. Moreover, the transfer of real-world processes to a digital world has been made possible which allows optimizing these processes.Through the project study, a simple and automated method with good accuracy was developed for estimating Brix and alcohol content during the fermentation process