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Ensemble-based screening of natural products and FDA-approved drugs identified potent inhibitors of SARS-CoV-2 that work with two distinct mechanisms
Get PDFThis research article published by Elsevier Ltd., 2021The recent outbreak of SARS-CoV-2 is responsible for high morbidity and mortality rate across
the globe. This requires an urgent identification of drugs and other interventions to overcome this
pandemic. Computational drug repurposing represents an alternative approach to provide a more
effective approach in search for COVID-19 drugs. Selected natural product known to have
antiviral activities were screened, and based on their hits; a similarity search with FDA approved
drugs was performed using computational methods. Obtained drugs from similarity search were
assessed for their stability and inhibition against SARS-CoV-2 targets. Diosmin (DB08995) was
found to be a promising drug that works with two distinct mechanisms, preventing viral replication
and viral fusion into the host cell. Isoquercetin (DB12665) and rutin (DB01698) work by inhibiting
viral replication and preventing cell entry, respectively. Our analysis based on molecular dynamics
simulation and MM-PBSA binding free energy calculation suggests that diosmin, isoquercetin,
rutin and other similar flavone glycosides could serve as SARS-CoV-2 inhibitor, hence an
alternative solution to treat COVID-19 upon further clinical validation
Development of indoor industrial environment monitoring system based on wireless sensor networks for a digital assembly plant
Get PDFA Dissertation Submitted In Partial Fulfillment of the Requirements for the Degree of
Master`s of Science in Embedded and Mobile System of the Nelson Mandela African
Institution of Science and TechnologyThe existing systems normally used to monitor the industrial environmental condition in factories
in Kenya are mostly wired systems and more expensive. Despite the benefits of tools and
emerging technology, most companies do not use automated systems due to the high installation
and maintenance costs and a lack of formal early-warning mechanism.
This research project intends to provide information using wireless sensor technology, which
comprises of sensors, Zigbee, raspberry pi, Arduino Uno, and wireless sensor network (WSN).
The system is developed using open-source hardware raspberry pi and Zigbee which proves to be
cost-effective and has low power consumption. The sensors will collect the data of various
environmental parameters and transmit it to the raspberry pi, which acts as a base station. The
raspberry pi will then transmit the data using Zigbee, and the processed data displayed on GUI
through the Zigbee on the receiver end.
The database was developed using MYSQL DB and the web application written in the PHP
programming language. In addidtion, the system is integrated with Zigbee technology to send
SMS and e-mail notifications to the respective registered users.
The developed system was tested at different plant areas to detect the concentration of Carbon
monoxide, temperature, humidity, and dust in the factory. The result shows that the system
responds positively when these parameters were detected and sends notification alerts via e-mail
and SMS. Finally, the data collected can be used for further data analysis and research in the
future
Comparative assessment of greenhouse gas fluxes and crop yields from various land use systems in Wakiso District, central Uganda
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of
Science and TechnologyLand use systems, mainly, crop farming is among the leading sources of greenhouse gas
emissions into the atmosphere, driving climate variability and global warming. This study
aimed to compare greenhouse gas fluxes and crop yields from various land use systems in
Wakiso District, Uganda. Specifically, the study; (a) assessed soil physical-chemical
properties and greenhouse gas fluxes from land use systems, (b) determined the effect of
cropping systems and management practices on greenhouse gas fluxes and crop yields, and
(c) assessed the effect of precipitation, soil temperature, and elevation on greenhouse gas
fluxes. Greenhouse gas fluxes and crop yields were monitored under split-plot design
experiments. Digital gas meters and static chambers were used to measure greenhouse gas
fluxes. Carbon dioxide fluxes were highest and lowest in sole cropped sweet potatoes under
non-mulched deep tillage (148.12 ± 3.40 µg C m−2 hr−1
) and grasslands (53.03 ± 1.70 µg C
m−2 hr−1
), respectively. Nitrous oxide fluxes were highest and lowest in sole cropped beans
under non-mulched reduced tillage (14.21 ± 0.40 µg N m−2 hr−1
) and banana-coffee intercrops
under compost - reduced tillage (3.76 ± 0.20 µg N m−2 hr−1
), respectively. Methane uptake
was highest and lowest in banana-coffee intercrops under mulched - no-tillage (-0.57 ± 0.00
µg C m−2 hr−1
) and sole cropped sweet potatoes under mulched - no-tillage (0.3 ± 0.01 µg C
m−2 hr−1
), respectively. Crop yields were slightly higher in intercropped than sole cropped
systems. Carbon dioxide fluxes were highest and lowest at 1200 - 1340 m (87.42 ± 5.60 µg C
m
−2 hr
−1
) and 900 - 1000 m (52.41 ± 3.90 µg C m−2 hr
−1
), respectively. Nitrous oxide fluxes
were highest and lowest at 1200 - 1340 m (6.82 ± 0.80 µg N m
−2 hr
−1
) and 900 - 1000 m (3.65
± 0.60 µg N m
−2 hr
−1
), respectively. Methane flux was highest at 1200 - 1340 m (0.31 ± 0.01
µg C m−2 hr
−1
) and lowest at 900 - 1000 m (0.04 ± 0.00 µg C m−2 hr
−1
). The results are vital in
understanding greenhouse gas fluxes and crop yields from various land use systems in
Ugand
Non-Newtonian heat and mass transfer on MHD blood flow through a stenosed artery in the presence of body exercise and chemical reaction
Get PDFThis research article was published by Communications in Mathematical Biology and Neuroscience, 2020A mathematical model of non-Newtonian blood flow, heat and mass transfer through a stenosed artery is studied. The non-Newtonian model is chosen to suit the Herschel-Bulkley fluid characteristics, taking into account the presence of body acceleration, magnetic fields and chemical reaction. The study assumed that, the flow is unsteady, laminar, two-dimensional and axisymmetric. The governing flow equations of motion were solved numerically using explicit finite difference schemes. The study found that velocity profile diminishes with increase in Hartman number and increases with body acceleration. The temperature profile is raised by the increase of body acceleration and the Eckert number, while it diminishes with the increase of the Peclet number. It was found also that the concentration profile increases with the increase of the Soret number and decreases with the increase of the chemical reaction. It was further observed that the shear stress deviates more when n > 1 than when n 1 exhibited higher magnitude value than Newtonian, Bingham and Herschel-Bulkley fluids
Production of biogas as a waste management option for textile effluent sludge: a case study of the a to z textile mills ltd
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Hydrology and Water Resources Engineering of the Nelson Mandela
African Institution of Science and TechnologyTextile effluent sludge management is becoming a major environmental management issue in
many agro-processing industries throughout Africa. This is mostly due to the limited and
ineffective means of management. This research explored the potential of producing biogas
as a strategy for reducing the on-site accumulation of textile effluent sludge. The co-digesting
of the textile effluent treatment plant (ETP) sludge with substrates such as sewage treatment
Plant (STP) sludge, cow dung (CD), and sawdust, was investigated as the main approach for
the anaerobic digestion (AD) process. ETP sludge and STP sludge were collected from A to
Z Textile Mills Ltd factory and a complete characterization was made in triplicate for
essential parameters, namely chemical ogygen demand (COD), biological oxygen demand
(BOD), alkalinity, volatile fatty acids (VFAs), carbon to nitrogen ratio (C/N ratio) and heavy
metals. Sludge mixtures were analyzed before and after digestion. Biogas production was
tested for 30 days at different mixing ratios (4:0, 3:1, 1:1, 0:4). A laboratory-scale reactor was
assembled for the experiments. High biogas yield was achieved from the co-digestion of ETP
sludge and STP sludge at a mixing ratio of 3:1, 1:1, and 1:3, and methane content was,
respectively, 87.9%, 68.9%, and 69.5% of the gas composition. Results from the current
study provide relevant information to improve the production of biogas from ETP sludge
through co-digestion and various pretreatment methods
Modeling the effect of storm-water flow on sewer system leakage
Get PDFA Dissertation Submitted in Partial Fulfilment 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 TechnologyThe storm-water overflow on manhole is numerically solved in this study. To produce a real
representation of storm overflow, the Navier-Stokes equations were used. Turbulence flow was
modelled using the standard k-epsilon turbulence model together with the volume of fluid
method for phase surface tracking. The open-source fluid dynamics tool OpenFOAM 5.0 was
used for solving the model and the visualization tool, paraview 5.4.0, was used for processing
the solution data. The convergence test was performed at three different mesh sizes. The
numerical solution was independent of mesh sizes. The risen storm-water column inside a
manhole exerts a non-uniform pressure on the manhole cover. The non-uniform pressure
distribution leads to different uplifting forces at manhole cover areas. However, the global
uplifting force remains constant as long as the storm-water overflow is happening on the
manhole. The overflow intensity is on manhole, and areas opposite to the outlet pipe give the
highest intensity of the leaking storm-water. The rate of storm-water column rise inside a
manhole is reduced by the use of manholes with larger width (or diameters) and pipes of larger
diameters
Simulation and optimisation of the pyrolysis of rice husk: Preliminary assessment for gasification applications
Get PDFThis research article published by Elsevier B.V, 2020Thermochemical conversion of biomass into useful products is a promising route to harness biofuels. This process is clean, renewable and can reduce the use of fossil fuel. In this study, SuperPro Designer (SPD) software and response surface methodology (RSM) is used to simulate and optimize rice husk pyrolysis process. The SPD simulator was built to handle kinetics and stoichiometric reaction of lignocellulosic composition of rice husk into final products. The SPD simulation and RSM optimization were performed at a temperature ranging from 350 to 800 °C and residence time of 0.25−60 s. The simulated results were in agreement with product yield published in the literature at an average relative error of 6.8 %. The combined effect of temperature and residence time were analysed by using RSM and analysis of variance (ANOVA). A cubic model for bio-oil and quartic model for char and gas yield were proposed. The desirability function in Design-Expert showed that the optimum bio-oil yield (36.72 %) could be attained at a temperature 588 °C and a residence time 0.25 s while the optimum gas yield (73.25 %) could be achieved at a temperature 798.8 °C and a residence time 15.47 s. These findings therefore revealed that the energy content of the rice husk could be harnessed by pyrolysis/gasification to obtain substantial fuel products
A Survey of Road Accident Reporting and Driver’s Behavior Awareness Systems: The Case of Tanzania
Get PDFThis research article published by Engineering, Technology & Applied Science Research, Vol. 10, No. 4, 2020,Road traffic accidents are a leading cause of death in
developed and developing countries. It has been shown that road
accident reporting systems could reduce their effects by
minimizing response time and mapping road accident-prone
areas. This paper provides an overview of the systems and
applications for road accident reporting and drivers’ behavior
awareness. A field survey, conducted in Dar es Salaam region in
Tanzania, investigated the current state of road traffic accident
reporting. Findings showed that the main means of reporting
road accidents were physical reporting and police emergency
phone calls. The absence of alternative means for reporting road
accidents causes information delay and lack of precise accident
location for the emergency first responders. This paper concludes
by proposing a mobile application system for road accident
reporting and drivers’ over-speed a
Use of agent – based models in characterizing farm types and evolvement in smallholder dairy systems
Get PDFA Thesis Submitted in Fulfilment of the Requirements for the Degree of Doctor of
philosophy in Information and Communication Science and Engineering of the Nelson
Mandela African Institution of Science and TechnologyThe ever-increasing demand for milk and dairy products has attracted research interventions
on how milk yield can be increased for the context of smallholder farmers. While bearing
significant contribution on milk production and fulfilment of the market demand, the
smallholder dairy farmers are faced with challenges that hinder productivity. Among the
challenges is the inadequate characterization of the dairy production systems and lack of
knowledge on factors attributing to their growth. This has resulted in aggregation of the
smallholder dairy farmers and lack of interventions tailored to suit particular farm types. By
using Tanzania and Ethiopia as case studies, this research identified the main determinants for
evolvement of smallholder dairy farmers. Evolvement in this research refers to, gradual
increase in milk yield. The factors that determine evolvement for individual farm typologies
were identified by using cluster and frequent pattern analysis. The differential influence of the
identified determinants towards increase in milk yield was studied by using Agent-based
modelling and simulation where each factor was observed.
Six farm types were identified for Tanzania and four for Ethiopia. The characteristics of the
farm types were enriched by frequent pattern analysis with confidence level 60% - 97%. Agentbased
modelling
revealed
that,
income
and
farm-based
determinants
influenced
an
increase
of
up
to
7.58
litres
above
the
average
(13.62
±
4.47)
for
Ethiopia.
For
Tanzania,
farm
and
farmerbased
determinants
influenced
an
increase
of
up
to
7.72
litres
of
milk
above
the
average
(12.7
±
4.89).
The
identified
determinants
could
predict
up to
96%
and
93%
of
the
variances
in
milk
yield
for
Tanzania
and
Ethiopia,
respectively.
There was an increase in milk yield based on
the identified evolvement determinants; from baseline data average milk yield of 12.7 ± 4.89
and 13.62 ± 4.47 to simulated milk yield average of 17.57 ± 0.72 and 20.34 ± 1.16 for Tanzania
and Ethiopia, respectively. Dairy development agencies should consider the disaggregation of
dairy farmers and prioritization of the determinants identified in this research for evolvement
of dairy farms. In future, it is important to develop a web or mobile application that can inform
smallholder dairy farmers about the identified evolvement determinants to aid on-farm decision
making
Lifetime improved WSN using enhanced-LEACH and angle sector-based energy-aware TDMA scheduling
Get PDFThis research article published by Cogent Engineering, 2020Network lifetime remains as a significant requirement in Wireless Sensor
Network (WSN) exploited to prolong network processing. Deployment of low power
sensor nodes in WSN is essential to utilize the energy efficiently. Clustering and
sleep scheduling are the two major processes involved in improving network lifetime. However, abrupt and energy unaware selection of cluster head (CH) is nonoptimal in WSN which reflects in the drop of energy among sensor nodes. This paper
addresses the twofold as utilization of sensor nodes to prolong the node’s energy
and network lifetime by LEACH-based cluster formation and Time Division Multiple
Access scheduling (TDMA). Clusters are constructed by the design of an EnhancedLow-Energy adaptive Clustering Hierarchy protocol (E-LEACH) that uses parallel
operating optimization (Grey Wolf Optimization (GWO) and Discrete Particle Swarm
Optimization (D-PSO)) for selecting an optimal CH and helper CH. The fitness values
estimation from GWO and D-PSO is concatenated to prefer the best optimal CH.
E-LEACH also manages the cluster size which is one of the conventional disadvantages in LEACH. CHs are responsible to perform energy-aware TDMA scheduling
which segregates the coverage area into 24 sectors. Alternate sectors are assigne