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Mathematical modeling on the effects of drug abuse to the societies
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Mathematical and Computer Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyDrug abuse remains to be the global burden causing a large number of death and disability, it
is now termed as a significant threat to public health for both developed and developing coun tries. This work presents a mathematical model as a new approach towards understanding and
controlling the drug abuse in Tanzania. The mathematical model to study the effect of drug
abuse in the society is developed and analyzed in this study. The model’s transmission process
is considered as a social contact process between susceptible individuals and drug users based
on the epidemiology principles. The model used the factors that were identified through feasi bility study as the significant factors that control the dynamics of drug abused population in the
particular society. The model is analyzed using next generation matrix method the numberof
new drug users that one drug user can produce in the entire period of abuse is computed and
identifies as an epidemic threshold value, R0. Using R0 the condition for existence and stabil ity of stationary point is established. Using numerical simulation, the dynamical behavior of
the model is explored and the result shows the significant contribution by the rate of adequate
contact between the susceptible individual and the drug user, and the rate of recovery of drug
user after rehabilitation as the major factors or players that dictate the dynamics of drug user
population in the society. The model is finally analyzed to study the dynamical behavior of the
drug abuse when control is applied, the result shows the drug users are minimized significantly.
The result signifiesthe importance of early control of the drug abuse problem through establish ment of the strict laws that will narrow the possibility of this bad practice in societies. It is then
vividly justified that, key result arising from this model is that prevention is indeed better than
cure
Risk assessment of heavy metals in water and sediments in the Mara river and its tributaries
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Environmental Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyThe present study assessed the levels of As, Cd, Cr, Hg, and Pb in water and sediments from the
Mara River and its tributaries in Tanzania. The Mara River has recently been exposed to
anthropogenic activities including, mining, industrial, and farming activities, which are potential
sources of heavy metals pollution. These emerging anthropogenic activities with a destructive
impact on the environment motivated the author to conduct a risk assessment of heavy metals in
the Mara River and its tributaries. In this endeavor, the author used indices, principal component
analysis (PCA), and sediment quality guidelines (SQGs) tools to study the heavy metals pollution
status in the area comprehensively. The study was conducted in the dry and rainy months of May
and October 2019, respectively. Geochemical indices used in the present study were geo accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), modified
contamination degree (mCd), pollution load index (PLI), potential ecological risk factor (Er
i
), and
potential ecological risk index (RI). Moreover, the sediment quality guidelines (SQGs) were used
for result comparisons. The principal component analysis (PCA) results indicated dominant
loadings for As and Pb in sediments during the rainy month. Comparing sediment concentrations
with sediment quality guidelines (SQGs) revealed that As and Cd may harm sediments-dwelling
aquatic organisms. Correlation coefficient results indicated that As had a strong negative
correlation with the other elements in sediments during the dry month. The analysis of
environmental risk indices revealed significant enrichment of sediments with As and Cd.
Contamination of As, Cd, and Pb along the Mara River was extremely severely enriched and
linked to anthropogenic sources. Moreover, Cd and As in tributaries were elevated in the rainy
month than in the dry months of 2019. As a result, enrichment factors of As, Cd, and Pb were
extremely severely enriched. However, low contamination degree and very low pollution existed
in water and sediments in the study area. Depending on rain and drought conditions, differentiated
efforts are needed to minimize the effects of elemental loadings in the Mara basin ecosystem—
with special attention for mitigation to be paid for As and Cd
Contamination assessment and optimization of coagulation-flocculation-sedimentation water treatment process for Kou river in northern Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Environmental Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyThe Babati Urban Water Supply and Sanitation Authority (BAWASA) in northern Tanzania
supplies water from the Kou River to Magugu town for domestic purpose, where its Fe (3.64
mg/L) and turbidity (87 NTU) concentrations were found in excess beyond their acceptable
limits. A coagulation-flocculation-sedimentation water treatment plant was planned to be
installed for treating the water, where the system’s performance is negatively influenced due
to inadequate applications, hence requiring optimization. The quality of sediment and water of
the Kou River was examined for physicochemical parameters and 9 metallic elements. The
water did not meet the requirements for aquatic, biological life, and irrigation purposes for at
least 1 metallic ion. Furthermore, pollution levels of the 9 metals in the river sediments were
evaluated using 6 pollution indices and a moderate contamination was found, hardly posing
ecological risk. A coagulation-flocculation-sedimentation water treatment system was
optimized to respond to coagulant dose, pH, mixing rates, mixing time, and settling time in the
removal of Fe and turbidity using jar-test. The optimum dose and conditions were: 30 mg/L
alum, an initial mixing rate of 150 rpm for 5 minutes, slow mixing rate of 20 rpm for 30
minutes and settling time for 30 minutes which was validated using scale-up pilot test and
resulted in 98.25% turbidity and 97.5% Fe removal. Furthe research on developing enhanced
time-saving optimization method and developing a dose indicator technology to assign alum
dose requirement based on the fluctuating characteristics of the raw waters (turbidity) is
recommended
Influence of land use change on nitrate sources and pollutant enrichment in surface and groundwater of a growing urban areas
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Environmental Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyIn the present study, three-year (1997, 2008 and 2017) satellite images as well as different hydro chemical parameters, nitrogen and oxygen isotopic composition of nitrate were used to examine
the impacts of land use and land cover change on surface and groundwater quality. Through
isotopic composition, sources of surface and groundwater nitrate contamination was also
elucidated. The results showed significant land use transition whereby land use changed from
forest and bare land to agricultural land and built-up areas. A slight reduction in the size of areas
covered by water bodies was also observed, from 8 km2
in 1997 to 7.4 km2
in 2017. Results
indicate differences in nitrate concentration that mirror land use changes. Samples with elevated
levels of nitrate above 10 mg/L were located near agricultural fields and areas with intensive
livestock keeping activities. In groundwater, ẟ
15N-nitrate and ẟ
18O-nitrate ranged from 3.2‰ to
20.1‰ with a mean value of 11.7 ± 1.8‰ and from 2.1‰ to 12.0‰ with mean value of 5.4 ±
1.8‰, respectively indicating nitrate was derived from inorganic fertilizer, manure and sewage. In
surface water, ẟ
15N-nitrate and ẟ
18O-nitrate ranged from 2.4‰ to 19.3‰ with mean value of 4.9 ±
1.4‰ and from 1.5‰ to 21.9‰ with a mean value of 13.5 ± 2.8‰, respectively indicating nitrate
from soil N. Isotopic composition data suggest sources of nitrate in groundwater dominated by
synthetic and organic fertilizer application and to a lesser extent a natural soil nitrate source
Simulation and performance analysis of municipal solid waste gasification in a novel hybrid fixed bed gasifier
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of PhD in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyMunicipal Solid Waste (MSW) is a main challenge to municipalities in developing countries due to
the increase in its production caused by technology development, community culture, population
growth, and urbanization. The challenge is heightened by the scarcity of dumping sites within
municipalities and the environmental impact associated with improper disposal management.
Thermo-chemical conversion technologies (gasification, pyrolysis and incineration) have become
to be known as practicable technologies for municipal solid waste management (MSWM). In this
study, the Hybrid Fixed Bed Gasifier (HFBG) model was developed using Aspen Plus in order to
merge the advantages of both downdraft and cross draft gasifiers and suppress their disadvantages.
Furthermore, experimental analysis of the flue gas was carried out on the HFBG. The TESTO 327-
1 flue gas analyzer was used to analyze the concentration of CO, CO2 and O2. The simulated results
showed that the feedstock MC of about 59.8 wt% was lowered to 6.8 wt%. The developed hybrid
fixed bed gasifier demonstrated an increase in
2
H
and
CO
of about 29.29 % and 37.05 % mole
fraction in the producer gas respectively. The syngas output was highly affected by the changes in
the ER as well as change in temperature. The composition for
2
H
and
CO
increases with increase
in temperature while the composition decreases with ER between 0.1 to 0.4. However, at this ER
CO2
and
H O2
tend to increases but above 0.4
CO2
and
H O2
decrease gradually. Experimental
results show that after the elapse of 30 minutes CO and CO2 concentration was 9.69% and 5.85%
respectively. Furthermore, after 150 minutes of the gasification process, the output concentration
for O2 was 17.2 % while the concentration for CO and CO2 was 0.0 % and 3.77 % respectively. The
experimental results revealed that, during the entire gasification process the concentration for CO
and CO2 were decreasing with time while O2 concentration was increasing. This result shows
diversion from the simulated results due to gasifier leakages. With high MC of MSW, the study has
shown that, HFBG can handle up 60 wt% as compared to downdraft which is limited to 20 wt%
Smart tanks juice level monitoring system: a case study of Raha beverages company limited Arusha, Tanzania
Get PDFA Project Report in Partial Fulfilment of the Requirements for the Degree of Master’s in Embedded and Mobile Systems of the Nelson Mandela African Institution of Science and TechnologyTanzania is among the East African Countries with rapid economic development, and it is a
low middle-income country. The development of industries is among the factors that contribute
to the economic growth of the country. Tanzania has been developing beverages industries;
however, these industries are facing a number of challenges including poor monitoring of tanks
during liquid pumping from boiler tank to dilution process. This problem resulted in spilling
fluids, tampered wine tests, and industrial accidents. The purpose of this project wasto develop
a system that can be able to monitor juice level within the tanks and regulate the pump using
voice commands through Alexa echo dot. The pump in this system was controlled by voice
commands, and an ultrasonic sensor was used to sense the juice level in the tank and send data
to a microcontroller, which processed the data and displayed the juice level on a Liquid Crystal
Display (LCD). Once the juice level reached a threshold level, the pump was automatically
turned off. The developed system successfully stopped overflows, accidents, and changes in
juice flavor during the dilution process, according to major findings from testing and validation
of the developed system. Existing way, however, are manual methodology, on the other hand,
are not interactive and are costly. The developed system also caters to the physically impaired
person, allowing them to engage in tank monitoring without difficulties. The system was
created for Raha Beverage Company Limited located in Arusha, Tanzania
The potential of water resources contamination around a large-scale gold mine
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master’s in Hydrology and Water Resources Engineering of the Nelson Mandela African Institution of Science and TechnologyThis study used the hydro-chemical properties and isotopic signatures of water to understand the
main sources of deterioration of water quality around the North Mara gold mine in Tarime
District, Mara Region. The chemical and isotopic signatures of the surface and groundwater were
used in understanding the origin, flow pattern, residence times, and vulnerability to pollution.
Most samples that were located downstream, western side of the mine tailings dam were slightly
acidic with pH as low as 4.6 and enriched with stable isotopes. Most samples with elevated
concentrations of Na+
, Cl-
, SO4
2-
and NO3
-
could not be isotopically linked with the local
geochemistry, but the observed water chemistry was controlled by evaporation and
anthropogenic effects. The Piper trilinear diagram showed Ca and Mg cations dominance, while
bicarbonates and sulfates dominated the anions. The heavy metals, Pb and Hg levels (mean 70.29
and 17.95 µg/L, respectively) were all higher than the levels recommended in both the World
Health Organization (WHO) and Tanzanian drinking water guidelines. The low pH values and
elevated concentrations of cyanides, heavy metals, and metalloids were probably associated with
mining activities. The radioactive isotope results indicated the vulnerability of the water to recent
contamination that could be attributed to near-surface anthropogenic activities. Moreover, stable
isotopic studies indicated the pollutants-carrying water flow pattern was from the eastern to the
western side of the study area. Lowland samples had higher tritium activities than the highland
ones. Therefore, the present study concludes that groundwater recharge from recent local
precipitation may have an impact on the sources studied and the use of shallow dug out wells
should be minimized
A mobile-based system for loans management: a case of banque de gestion et de financement
Get PDFA Project Report Submitted in Partial Fulfillment of the Requirements of the Award the Degree of Master of Science in Embedded and Mobile Systems of the Nelson Mandela African Institution of Science and TechnologyAs technology has evolved and has embraced nearly all sectors of human daily life, bank
processes are not left behind. Moreover, mobile technology penetration and internet access in
Africa have increased a lot. In Burundi, internet users have increased by 452 thousand
(+39%) between 2020 and 2021. Therefore, the introduction of a mobile system for the
banking process would be in line with the region’s digital trends. As for the case of the
Burundian bank, the Banque de Gestion et de Financement (BGF) some processes are still
done manually and the physical presence of the client is mandatory. This is the case in the
loan application process. Existing studies have presented digital solutions for loan
management but the studies are not tailored to Burundian banks' processes and regulations
and there are security issues that are not addressed. To tackle the above challenges and
enhance the loan management process, this study proposes a mobile-based system that
manages the loan requests: the customer applies for a loan and is informed of the approval or
rejection of the application online without reaching the banks’ offices. The system provides
feedback to the customer within fewer processes and in secure and reliable conditions. The
proposed system does not incorporate the entire loan management process. The flow of
information within BGF departments during the loan application analysis is not included in
the proposed system. The system development process was based on the agile model
methodology and the prototype was completed with the use of tools such as android studio,
html5, css3, angular JavaScript, bootstrap for the front end, and PHP and MySQL for the
back end. The system verification and validation included 10 participants from BGF (staff)
and 15 BGF customers. The 25 participants evaluated the proposed system and gave positive
feedback regarding the performance, ease of use, and usefulness
Does Pesticide exposure contribute to the growing burden of non - communicable diseases in Tanzania
Get PDFThis research article was published by Elsevier B.V., 2022Pesticide exposure is becoming a public health concern in Tanzania. This review highlights
the existing information on pesticide exposure, health effects, knowledge, and awareness
on pesticide handling and management and in the current pesticide regulations in Tanza-
nia. There was a significant increase in pesticides importation of up to 4.5 million liters’
in 2017 and registration of 1,114 pesticides in 2018. Food, water and soil are subjected
to unacceptable levels of pesticide residues. Inadequate awareness of the effects of pes-
ticides among the population of Tanzania was observed. Even though there are existing
regulations governing pesticides, the inadequate management of pesticide in Tanzania was
identified to contribute the malpractices in pesticide usage. Persistence of the malpractice
in pesticide handling has been observed which argues for immediate intervention. Limited
information concerning pesticide poisoning and adverse health effects has been reported
but the magnitude of the health effects is not well known. There is scarce data on the
association between pesticide and non-communicable diseases (NCDs) in Tanzania. This
review is informative to the policy, practices, and intervention towards the existing situa-
tion of pesticide in Tanzania. In addition, it calls for further investigation of the absence of
data on pesticide exposure and NCD
Impact of N-Acetyl Cysteine (NAC) on Tuberculosis (TB) Patients—A Systematic Review
Get PDFThis research article was published by MDPI in 2022Sustained TB infection overproduces reactive oxygen species (ROS) as a host defense mechanism. Research shows ROS is destructive to lung tissue. Glutathione (GSH) neutralizes ROS, although it is consumed. NAC is a precursor of GSH synthesis, and administering an appropriate dose of NAC to patients with respiratory conditions may enhance lung recovery and replenish GSH. The present review searched for articles reporting on the effects of NAC in TB treatment from 1960 to 31 May 2022. The PICO search strategy was used in Google Scholar, PubMed, SciFinder, and Wiley online library databases. The COVIDENCE tool was used to delete inappropriate content. We eventually discovered five clinical trials, one case report, seven reviews, in vitro research, and four experimental animal studies from the twenty-four accepted articles. The use of NAC resulted in increased GSH levels, decreased treatment time, and was safe with minimal adverse events. However, the evidence is currently insufficient to estimate the overall effects of NAC, thus the study warrants more NAC clinical trials to demonstrate its effects in TB treatment