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Canarium schweinfurthii resin as an organic binder for carbonized briquettes
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyCharcoal is the predominant fuel used in many developing countries for domestic and commercial
purposes. Transport and handling of charcoal produces fines amounting to 10-20% by weight. The
fines can be turned into lumps of charcoal by briquetting using suitable binders. This study
investigated the use of Canarium Schweinfurthii resin as a binder for production of carbonized
briquettes from charcoal fines. The binder and charcoal fines were characterized through
proximate analysis, ultimate analysis, higher heating value (HHV), 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 briquettes determined were bulk density, impact resistance index (IRI), compressive strength
(CS), splitting tensile strength (STS), water resistance index (WRI), and morphology. The
chemical properties of briquettes determined were proximate analysis, ultimate analysis, HHV,
and energy density. The physical properties of briquettes were analysed using Design Expert. One way ANOVA and Fisher’s LSD were used to analyse the chemical properties of briquettes. The
phases of the Water Boiling Test (WBT) considered were Cold Start High Power, Hot Start High
Power and Simmer phases. Ignition properties, combustion properties, gas temperature, water
temperature, ambient temperature, emissions, and WBT performance metrics were investigated
using the Laboratory Emission Monitoring System. The ignition properties included ignition time,
flame and incandescence. The combustion properties included smoke, flame, soot, and ash. The
emissions measured were PM2.5, S2, , , , and 2. The WBT performance metrics
evaluated were time to boil, burning rate, thermal efficiency, specific fuel consumption, firepower,
total emissions, specific emissions, emissions per MJ, and emissions rate. The ash from charcoal
fines was analysed using x-ray diffraction. The briquettes had a bulk density of 0.770-1.036 g/cm3
,
IRI of 2.90-73.33, CS of 2.25-10.94 MPa, STS of 0.09-0.42 MPa, WRI of 99.26-99.29, and an
HHV of 29.7-31.3 MJ/kg. The ignition time was 6.47-7.01 min, time to boil was 14.7-41.9 min,
burning rate was 1.1-8.2 g/min, thermal efficiency was 21.79-54.61%, specific fuel consumption
was 21.7-70.1 g/L, and firepower of 535.9-4123.2 W. The ash was found to contain 3
(76.6
wt%), (13.1 wt%) and amorphous compounds (10.3 wt%). Design Expert predicted briquette
B40 with the optimum physical properties. The produced briquettes can be used as an alternative
source of fuel to wood fuel since they exhibit similar combustion properties
Impact of illegal livestock grazing on the socio-ecologica role of trophy hunting: the case of Moyowosi Kigosi game reserve, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyTanzania has set aside almost 40% of its land for conservation and trophy hunting is the main
activity conducted in an area covering about 80% of Tanzania’s conserved land. Trophy hunting
conserves wildlife inside and outside Protected Areas (PAs) and provides socio-economic
incentives for communities to conserve wildlife. Despite its importance, hunting companies
surrendered 45% of Tanzania’s hunting blocks to the government mainly due to habitat
destruction mediated by illegal livestock grazing. Unfortunately, there is no empirical
information on how illegal grazing affects trophy hunting. Therefore, the impact of illegal
grazing on the socio-ecological role of trophy hunting was examined using Moyowosi - Kigosi
Game Reserve (MKGR) as a case study. The study investigated whether the physical presence
of trophy hunting deters illegal grazing, improves wildlife habitats, and diversifies rural income.
Field experiments, laboratory work, questionnaires, and official records from MKGR were used
in this study. The study revealed that illegal grazing persisted in MKGR over three decades
(1990 – 2019). It destructed wildlife habitats, reduced forages, enhanced soil compaction,
increased human activities in the hunting blocks, and caused hunting blocks to lose their
economic viability. Also, there is a higher dietary overlap between buffalo and livestock,
buffalo density decreased in invaded areas and buffalo deployed spatial partitioning of about 5
km to avoid livestock. The study confirmed that indeed, trophy hunting plays an important
socio-ecological role within and outside protected areas. If affected, it will compromise the
multiple socio-economic benefits often gained by the local communities. The ecological role
of trophy hunting in conserving grass biomass and cover, enhancing soil infiltration and
penetration by preventing illegal grazing as observed in operational hunting blocks is also
apparent. The study recommends the MKGR address illegal grazing at the hotspot areas and
should conduct studies on areas outside the reserve that could be re-seeded with grass species
preferred by herders. The MKGR should establish awareness campaigns on the impact of illegal
grazing and develop a restoration plan to enhance soil nutrients, support herbaceous cover, and
diversify wildlife species to boost ecosystem functioning and prevent further deterioration of
this globally important Ramsar site in Tanzania
Increasing agricultural soil phosphate (P) status influences water P levels in paddy farming areas: Their implication on environmental quality
Get PDFThis research article was published by Case Studies in Chemical and Environmental Engineering 6 (2022) 100259ntensive paddy farming activities involve higher use of irrigation water and agrochemicals to increase crop
productivity per unit area. However, a practice may result in environmental challenges due to nutrient loss and
agro-chemicals contamination from agricultural fields. The present study characterized the relationship between
agricultural soil phosphate (P) status and P levels in water bodies in Usangu agro-ecosystem (UA), the area
famous for paddy rice production in Southern Highland Tanzania. The studied soil pH ranged from 6.4 to 7.6,
while water pH was 4.9–6.8, which varied among study sites and negatively correlated to each other. This study
found a positive correlation between P concentration (P < 0.001, R2 = 0.78) in agricultural soils and water
samples in the study area, where P in soil were 1.66–17.56 mg/kg and 0.02–1.65 mg/L in water. This correlation
pattern of P in soil and water indicates that increased P content in farming areas under poor management
(flooding system of irrigation), as observed in the study area likely to influence increased levels of P in water
bodies leading to water eutrophications, but also reducing the land productivity per unit area. The significant P
enrichment (>1.65 mg/L) from agricultural fields to water bodies found in different water samples from irri-
gation schemes potentially leads to eutrophication. To sustainably manage P concentration in water bodies and
increase land productivity per unit area, the hotspot for P loss to water bodies in the agro-ecosystem has to be
identified and managed, but also flooding irrigation system standard in the study area has to be abandoned to
reduce plant nutrient loss and contamination of water bodies
Assessment of contamination level of a Tanzanian river system with respect to trace metallic elements and their fate in the environment
Get PDFThis research article was published by IWA Publishing, 2022The quality of water and sediments from a marginally-studied river was investigated with respect to As, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn
including their fractionation behavior and environmental risk. Samples were collected along the Kou River that flows across two districts in
the Manyara region of Tanzania. The leaching behavior of Fe was studied using sequential extraction fractionation and kinetics approach. The
Kou water failed to meet the irrigation, aquatic, and biological life standards with respect to one of more trace metallic elements (TMEs). Fe
concentration in the river water ranged from 4.1 to 5.38 mg/L, exceeding all the three standards. Six pollution indices were applied to assess
the contamination and ecological risks of the nine trace metallic elements in the sediments. Overall, the metals were found to moderately
contaminate the sediments. Cr, Fe, and Mn fell under the ‘severely polluted’ sediment quality class. Fe was the only metal that was found to
significantly pollute both the river water and sediments. The Fe fractions in the sediments were in the order of residuals.Fe-Mn bound.or ganic bound.carbonate bound.water soluble.ion exchangeable; 7.8% of the total Fe content was bioavailable with a low potential to leach
from the sediments. Under natural conditions, the sharpest release of the non-residual mobile fractions of Fe were identified to occur within
the first 24 hours with the maximum Fe leached being 0.14% on the 12th day. None of the metals in the sediments were found with a poten tial to pose ecological ris
Machine learning model for prediction and visualization of HIV index testing in northern Tanzania
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 TechnologyInfection with the human immunodeficiency virus and acquired immunodeficiency syndrome
(HIV/AIDS) continue to pose a threat to Tanzanian society. Various tactics have been used to
improve the number of persons who are aware of their HIV status. Index testing stands out
among these methods as the most effective way to count the number of HIV contacts who may
be at risk of catching HIV from HIV-positive individuals. The current HIV index testing,
however, is manual, which presents a number of difficulties, including inaccuracies, is time consuming, and is expensive to operate. In order to forecast and depict HIV index testing, this
study presents the findings of the machine-learning model. The software development
procedure was in accordance with agile software development principles. The regions of
Kilimanjaro, Arusha, and Manyara in Tanzania are where the data was gathered which
consisted of 11 features and 6346 samples. The dataset was then separated into training sets
with 5075 samples each and testing sets with 1270 samples (80/20). The datasets were
subjected to the methods Random Forest (RF), XGBoost, and Artificial Neural Networks
(ANN). Random forest MAE (1.1261), XGBoost MAE (1.2340), and ANN MAE (1.1268)
were the three results obtained. Random forest algorithms had the lowest mean absolute errors
(MAE). Therefore, RF appearing to have the highest performance when compared to the other
two algorithms. In comparison to men (17.4%), data visualization reveals that females are more
likely to test for HIV and to name their partners (82.6%). Additionally, there were higher
instances of persons listing and mentioning their partners in the Kilimanjaro region. This work
helped us realize the importance of machine learning in predicting and visualizing HIV index
tests in general. The created model can help decision-makers build a viable intervention to stop
the spread of HIV and AIDS in our communities. The report suggests that health centers in
other areas employ this concept to make their work more straightforward
Representation of seasonal land use dynamics in SWAT+ for improved assessment of blue and green water consumption
Get PDFThis research article was published by Hydrology and Earth System Sciences, 2022In most (sub)-tropical African cultivated regions, more than one cropping season exists following the (one or two) rainy seasons. An additional cropping season is possible when irrigation is applied during the dry season, which could result in three cropping seasons. However, most studies using agro-hydrological models such as the Soil and Water Assessment Tool (SWAT) to map blue and green evapotranspiration (ET) do not account for these cropping seasons. Blue ET is a portion of crop evapotranspiration after irrigation application, while green ET is the evapotranspiration resulting from rainfall. In this paper, we derived dynamic and static trajectories from seasonal land use maps to represent the land use dynamics following the major growing seasons to improve simulated blue and green water consumption from simulated evapotranspiration in SWAT+. A comparison between the default SWAT+ set-up (with static land use representation) and a dynamic SWAT+ model set-up (with seasonal land use representation) is made by a spatial mapping of the ET results. Additionally, the SWAT+ blue and green ET were compared with the results from the four remote sensing data-based methods, namely SN (Senay), EK (van Eekelen), the Budyko method, and soil water balance method (SWB). The results show that ET with seasonal representation is closer to remote sensing estimates, giving higher performance than ET with static land use representation. The root mean squared error decreased from 181 to 69 mm yr−1, the percent bias decreased from 20 % to 13 %, and the Nash–Sutcliffe efficiency increased from −0.46 to 0.4. Furthermore, the blue and green ET results from the dynamic SWAT+ model were compared to the four remote sensing methods. The results show that the SWAT+ blue and green ET are similar to the van Eekelen method and performed better than the other three remote sensing methods. It is concluded that representation of seasonal land use dynamics produces better ET results, which provide better estimations of blue and green agricultural water consumption
Mobile-based system for solid waste management to improve customer satisfaction and revenue generation: a case of Shinyanga municipal council
Get PDFA Project Report 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 TechnologySolid waste management has recently reached the top of the priority list in the modern world,
but solid waste disposal practices are often neglected. In addition, managing municipal solid
waste is one of the most challenging municipalities in Tanzania. Municipalities in Tanzania are
responsible for the management of solid waste in their cities, but they have significant obstacles
to providing a system that meets the needs of customers and improving revenue collection using
the electronic payment system. This study determined the efficacy of solid waste management
systems in Shinyanga municipality in customer dissatisfaction with waste collection service and
unfriendly revenue collection. The objective of this study was to analyze the current waste
collection system to determine the strength and weakness of the method used by solid waste
generators and collectors to access the solid waste collection service, their willingness to pay
for the service, municipal officials to manage revenues and complaints, and the participation of
political leaders in offering cooperation. The analysis was to identify the requirements for the
development and validation of the mobile-based system to improve customer satisfaction and
increase revenue collection. The study used a mixed method approach, which included
quantitative and qualitative data collection techniques to collect primary data with two sampling
techniques, purposive sampling and multistage sampling. The developed mobile application
adopted the evolutionary prototyping steps from the software development life cycle to
implement all modules of the mobile application by allowing iteration of the development
phases to ensure that user requirements are satisfied. The developed mobile based system was
evaluated by the technical and end-user on the availability, scalability, user friendliness,
consistency, navigation, feedback, performance, and security at both levels of. Although the
results from the 10 ward areas indicate that 57% have access to solid waste collection services
and collection is carried out daily at 31%, while two-thirds expressed dissatisfaction with the
current waste collection system, the results after validating the developed mobile app show that
the majority (85%) are willing to use the developed mobile app because it is useful to them
since their negative emotions associated with solid waste collection were resolved, such as
waiting for a waste collector for an extended period, paying informal waste collectors who
increase waste collection costs, and being charged without receiving service, as they already
felt overcharged. The study proposes a mobile application for solid waste management that will
be used at and outside the Shinyanga Municipal Council for customer satisfaction and revenue
growth
Investigation of sediment source and delivery dynamics in an east African hydropower reservoir using sediment tracing technology
Get PDFA Thesis Submitted in Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Environmental Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyThis study aimed to reconstruct the sedimentation rates over time and identify the changing
sources of sediment in a major hydropower reservoir in Tanzania, the Nyumba ya Mungu
(NYM). The study also aimed to evaluate the soil carbon as a proxy for erosion risk in the
catchment. Fallout 210Pb measurements were used to estimate age of sediment deposits and broad
changes in sedimentation rates were reconstructed. Sedimentation peaks were cross referenced to
geochemical profiles of allogenic and autogenic elemental constituents of the sediment column
to confirm a causal link. Finally, geochemical fingerprinting of the sediment cores and potential
sources were compared using a Bayesian mixing model (MixSIAR) to attribute the dominant
riverine and land use sources to the reservoir. Reservoir sedimentation generally increased from
0.1 g cm−2
yr−1
in the lower sediment column to 1.7 g cm−2
yr−1
in the most recent deposits.
These results correlated to changes in allogenic and autogenic tracers. The model outputs
revealed that the Kikuletwa River with 60.3%, was the dominant contributing tributary to the
total reservoir sediment and the Ruvu River 39.7%. However, downcore unmixing results
indicated that the latest increases in sedimentation is moistly driven by an increased contribution
from the Ruvu River. Cultivated land (CU) was shown to be the main land use source of riverine
sediment, accounting for 38.4% and 44.6% in Kikuletwa and Ruvu rivers respectively. The “soil
slake test” method for soil aggregate stability in water (WSA) indicated a significant decrease in
soil aggregate stability in cultivated land in comparison to other land use types which indicates
that the unsustainable land use changes can thus potentially increase the susceptibility of soils to
erosion by water when soil organic matter (SOM) is reduced. This study has explicitly
demonstrated that the integration of sediment tracing and -dating tools can be used for
quantifying the dominant source of sediment infilling in East African hydropower reservoirs.
The results underscore the necessity for catchment-wide management plans that target to limit
soil erosion and reduce further impact to rivers and reservoirs to maintain and enhance food,
water and energy security in Eastern Africa
An Optimal Smart Tank Juice-level Monitoring System for Beverage Industries: A Case Study of Raha Beverages Company Limited, Arusha, Tanzania
Get PDFThis research article was published by IEIESPC(IEIE Transactions on Smart Processing and Computing), Vol. 11, No. 03, 2021Poor monitoring of levels in juice tanks is among the challenges that beverage industries face when pumping liquid from one tank to another. This leads to spilling fluids, faulty juice tests, and industrial accidents. To keep track of the liquid level in a tank, various approaches have been used. Existing technologies are costly and not interactive, and the majority do not benefit individuals with physical disabilities when manual monitoring is needed. The purpose of this paper is to present an optimal smart tank juice-level monitoring system that can be used in beverage industries. The system is able to monitor the juice level within a tank and regulate a pump using voice commands via Alexa and the Amazon Echo Dot. The proposed system was tested and validated, with key findings being that the developed prototype prevented overflowing, accidents, and changes in juice flavor during the dilution process. This paper contributes to the body of knowledge for food and beverage industries in that engineers and operators of beverage industries can monitor the level of juice in a tank, as well as enhance communication when pumping juice from one tank to another in real time
Agro-Meteorological data Collection using a LoRaWAN-Based IoTSensor Network
Get PDFThis research article was published by the International Journal of Advances in Scientific Research and Engineering, Volume 8, Issue 2, 2022Generally, the variation of meteorological conditions has a significant influence on the agriculture sector in general. In Tanzania, the study conducted in 2015 found most of the existing automatic meteorological stations are not working, and the surveyed manual meteorological stations record meteorological data in the cards daily, but cards are sent in a month to month time interval to the respective organs, this makesthe concept of early warning difficult. Therefore having near-real-time meteorological data will enable the crop monitoring and forecasting systems to monitor crop development and provide early warning to the farmers and the government. The advancement of the Internet of Things (IoT) offers possibilities for developing an integrated sensors network to collect meteorological data on a near-real-time basis. In this study, the developed integrated sensor network includes sensors, which record remote meteorological data such as rainfall, humidity and temperature, a communicationnetwork, and a web application thatenhance data visualization in both graphical and tabular format. In the communication system, the LoRa technology was used, which is more preferable compared to other Low Power Wide Area Network (LPWAN) technologies such as NB-IoT and Sigfox for this application. The developed system uses the LoRa Gateway Operating system which provides capabilities to build a private network, and make it more cost-efficient by reducing the operation cost for account subscription, in online platforms such as The Things Network (TTN), ThingPark, ThingSpeak, and Loriot to avoid free accounts limitations. Moreover, the developed system can work in remote areas with limited Internet access as the meteorological stations can communicate with the gateway at a distance of up to 25km