2647 research outputs found
Sort by
Smart system for monitoring and controlling oxygen gas level in high purity germanium detector room: a case study of Tanzania atomic energy commission, Arusha-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 TechnologyLow-oxygen air causes death all around the world. Even though the number of fatalities varies
from year to year and location to location, nitrogen gas replaces oxygen in the atmosphere,
increasing its percentage to less than 21% by volume. Special environment/room such as High
Purity Germanium Detector Room (HPGDR) requires tailored techniques to ensure that oxygen
levels are properly monitored to avoid any hazard. This study was designed for the HPGDR at
Tanzania Atomic Energy Commission (TAEC). The V-Model was used which works well for
small projects with clear requirements. It facilitated each step before moving on to the next level
of development, resulting in the design of an error-free and high-quality system. The ESP32
microcontroller which is built in Wi-Fi was used to send data to the Blynk cloud server. The
developed system is made up of four parts: The sensing component continuously monitors
environmental parameters with Oxygen, MQ-135, and DHT22 sensors. The processing section
processes and analyzes sensor data. The notification component alerts workers via a buzzer and
Short Message Service (SMS). While the controlling component replaces the contaminated
compressed air with fresh air from outside. To provide real-time monitoring, the developed system
employs the Blynk Application. All processed data was accessible via mobile phones using the
Blynk application. The system eliminates both danger and fear because it alerts workers through
SMS and switches on exhaust fan automatically. The HPGDR workers and the administrators are
the main beneficiaries of the developed system
Field evaluation of a novel one step malaria p.f and p.f/p.v rapid diagnostic tests in Pwani region, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Public Health Research of the Nelson Mandela African Institution of Science and TechnologyMalaria rapid diagnostic tests (mRDTs) play an important role in the early detection of
symptomatic and asymptomatic malaria in endemic areas. While several mRDTs are currently on
the market, the availability of mRDTs with high sensitivity and specificity will add value in the
fight against malaria. We evaluated the field performance for malarial diagnosis of a novel One
Step Malaria (P.f/P.v) Tri-line and One Step Malaria (P.f) rapid test kits in Pwani, Tanzania. In a
cross-sectional study conducted in Bagamoyo and Kibiti districts in Tanzania, symptomatic
patients were tested using the SD BIOLINE, One Step Malaria (P.f/P.v) Tri-line and One Step
Malaria (P.f) rapid test kits, microscope and qPCR. Samples tested positive by microscope, and
verified by qPCR as the confirmatory method were analysed to determine sensitivity of the test
kits. An additional qPCR assay was carried out to detect HRP-2 gene deletion on mRDT negative
but microscope and qPCR positive samples. The sensitivity and specificity of One-step P.f/P.v Tri line mRDTs was 96.0% (CI: 93.5% to 97.7%) and 98.3% (CI: 96.8% to 99.2%) respectively. One
step P.f mRDT had sensitivity and specificity of 95.2% (CI: 92.5% to 97.1%) and 97.9% (CI:
96.3% to 99.0%), respectively. Positive predictive value (PPV) was 97.6 % (CI:95.4% to 98.7%)
and negative predictive value (NPV) was 96.2% (CI:95.5% to 98.3%) for the One-step P.f/P.v Tri line mRDTs., while One step P.f mRDT had positive predictive value (PPV) and negative
predictive value (NPV) of 97.0% (CI:94.8% to 98.3% ) and 96.7(CI:94.9% to 97.9%), respectively.
9.8 % (CI: 7.84 -11.76) of all samples tested and reported to be malaria-negative by mRDT had
HRP-2 gene deletion. One Step Malaria (P.f/P.v) Tri-line and One Step Malaria (P.f) rapid test kits
have similar sensitivity and specificity as the standard mRDT that is currently in the market,
demonstrating the potential to contribute in the fight against malaria in endemic areas. However,
the identified malaria parasites population with HRP-2 gene deletion pose threat to the current
mRDT usefulness in the field and warrants further investigations
Underutilized Cashew Apple Fruit: Its Utility and Development as a Source of Nutrients and Value Added Products in Tanzania
Get PDFThis research article was published in the Current Research in Nutrition and Food Science Vol. 11, No. (1), 2023The tropical cashew tree, Anacardium occidentale L., has remarkable
potential. The tree produces the pseudo-fruit known as the cashew
apple and nuts. The apple is sweet, juicy, and loaded with dietary
fiber, phytonutrients, minerals, and vitamin C. Despite having high
nutritional content, the cashew apple is neglected in low-technological
nations like Tanzania, primarily because of negligence over the well-
known nut, its perishability, and its astringent taste. Contrarily, cashew
apples are processed into various goods in high-income nations where
food processing and technology improvements have been realized.
Cashew apple products include juice, syrup, wine, alcohol, dietary fiber
extracts, and animal feed. However, inadequate technologies and skills
for postharvest handling and value addition have led to a considerable loss
of cashew apples, contributing to pronounced food and nutrition insecurity.
This review documents the production of cashew apples in Tanzania
and reveals the fruit's critical underutilization and potential nutrition and
economic opportunities. This documentation may call for interventions to
create awareness of the importance of cashew apples in social-economic,
food, nutrition and health, empower locals, and invite new processing
technologies to diversify and extend shelf-life. The ultimate goal is to
promote the utilization of this abandoned nutritious fruit. Such approaches
may reduce postharvest losses and impact food and nutrition security and
the social-economic empowerment of smallholder farmers
Land Use and Environmental Gradients Influence on Riparian Woody Plant Diversity and Structure in Lake Manyara Watershed Ecosystem, Tanzania
Get PDFThis research article was published in Open Journal of Ecology, Volume 13, 2023.Riparian vegetations are important in supporting ecological connectivity between aquatic and terrestrial ecosystems. The structure and species composition of riparian woody plants have been subjected to multiple forces with varying degree of influences. This study examined the influence of land use and environmental gradient to the structure and composition of the riparian woody plants in northern Tanzania. A total of 270 plots were surveyed for woody plant species in the riparian ecosystems and later analysed to determine the influence of land use categories (homegarden, crop field, woodlot, open canopy forest, and closed canopy forest) and environmental variables (temperature, precipitation, elevation and slope) to the species richness, abundance, and stand parameters. Basal area was higher in woodlots, homegardens and crop fields than in the open and closed canopy forests; and as expected the reverse was true for the number of stocking density. Correlation among stand parameters with environmental variables varied significantly. Species richness and species abundance were negatively correlated to precipitation, temperature and elevation, while stocking density and basal area were positively correlated to precipitation. The study recommends continual retentions of trees on farm, further promoting of agroforestry interventions and sustainable utilization of woody plants in open and close canopy forests
Insecticidal Activity of Selected Plant-Derived Essential Oils against Papaya Mealybug (Paracoccus marginatus)
Get PDFThis research article was published in the Journals of Sustainability, Volume 15, Issue 23, 2023The current study aims to assess the effectiveness of three essential oils derived from
neem, citrus, and garlic against papaya mealybug. Papaya seedlings were transplanted in the
field in a completely randomized block design with eight treatments with four replications. The
treatments included neem, citrus, and garlic oils in combination with isopropyl alcohol or paraffin
oil as an adjuvant. Results from this study showed that neem oil at 1.5% + 0.2% isopropyl alcohol
was effective against papaya mealybug by 93.0% equivalent to the positive control (imidacloprid)
(99.4%), followed by citrus oil at 1.5% + isopropyl alcohol (76.3%) and citrus oil at 1.5% + paraffin oil
(68.8%), compared with the untreated 0.01%. Similarly, application of the plant-derived essential oils
and adjuvants resulted in positive effects on plant parameters (plant height, number of leaves, flower
buds, number of fruits, and fruit weight) and, hence, increased papaya yield from an average of 38 to
90 fruits/plant at first harvest. The finding from this study provides an understanding of papaya
farmers towards the use of natural plant products, particularly plant-derived essential oils, and their
benefits, which may encourage farmers to increase papaya production and minimize the usage of
synthetic pesticides to avoid pest resistance
Environmental risks of a commonly used pyrethroid: Insights from temporary pond species of the Lake Manyara Basin, Tanzania
Get PDFThis research article was published by Science DirectEnvironmental risks posed by widespread pesticide application have attracted global attention. Currently, chemical risk assessments in aquatic environments rely on extrapolation of toxicity data from classic model species. However, similar assessments based on local species could be complementary, particularly for unusual living environments such as temporary ponds. Here, we carried out an environmental risk assessment (ERA) of a pyrethroid model compound, cypermethrin, based on local temporary pond species. First, we measured cypermethrin residue concentrations in rivers, irrigation canals and temporary ponds in the Lake Manyara Basin (LMB). Then, we estimated the environmental risks of cypermethrin by combining these data with acute toxicity data of three resident species across three trophic levels: primary producers (Arthrospira platensis), invertebrate grazers (Streptocephalus lamellifer) and fish (Nothobranchius neumanni). Furthermore, we compared the derived ERA to that obtained using toxicity data from literature of classic model species. Cypermethrin residue concentrations in contaminated systems of the LMB ranged from 0.01 to 57.9 ng/L. For temporary pond species, S. lamellifer was the most sensitive one with a 96 h-LC50 of 0.14 ng/L. Regardless of the assumed exposure concentration (0.01 and 57.9 ng/L), the estimated risks were low for primary producers and high for invertebrate grazers, both for local species as well as for classic model species. The highest detected cypermethrin concentration resulted in a moderate risk estimation for local fish species, while the estimated risk was high when considering classic fish models. Our results confirm that, at least for pyrethroids, ERAs with classic model species are useful to estimate chemical risks in temporary pond ecosystems, and suggest that complementary ERAs based on local species could help to fine-tune environmental regulations to specific local conditions and conservation targets
The effects of curcumin and blueberry on axonal regeneration after peripheral nerve injury
Get PDFThis research article was published by Elsevier in 2023he purpose of this study was to analyze the axonal regeneration and therapeutic effects of curcumin and
blueberry administration following peripheral nerve injury using stereological, electron microscopic and elec trophysiological methods. Animals in were assigned into one of four groups - control (Cont), injury (Inj),
injury+curcumin (Cur) and injury+blueberry (Blue). Following the induction of sciatic nerve crush injury (75
Newtons for 5 s) in the Inj, Cur, and Blue groups, the rats in the Cur group received intraperitoneal injection of
30 mg/kg curcumin (Sigma C1386) and the rats in the Blue group received 4 g/kg blueberry by gavage over a
four-week period. The rats in the Cont and Inj groups were not exposed to any substance. All animals were given
standard chow. Sciatic functional index analyses were performed on the 14th and 28th days after injury, and
electromyography (EMG) results were recorded. Stereological analysis of the nerve was performed under light
microscopy. Light and electron microscopies were used for the histopathological evaluation of the sciatic nerve.
Analysis of myelinated axon numbers revealed no significant differences between the Inj group and the Cur and
Blue groups. However, a significant difference was observed between the Blue and Inj groups in terms of axonal
areas. EMG test results differed between the Blue and the Inj groups (p < 0.05), but no significant difference was
observed between the Inj and Cur groups. Electron microscopic analysis revealed protective effects of curcumin
and blueberry treatment after injury. The use of the curcumin and blueberry may represent a supportive
approach to the protection of nerve fibers after peripheral nerve crush injury
Reconstructing Historical Distribution of Large Mammals and their Habitat to Inform Rewilding and Restoration in Central Tanzania
Get PDFThis research article was published by SAGE Publications Ltd in 2023Backgroundand research aim:In the anthropogenic landscapes where historically wildlife existed, there can be a potential for rewilding to reverse extinction. However, there is limited literature providing approaches to achieve successful rewilding. The current study aimed at providing empirical based methodological procedures for successful rewilding of the University of Dodoma (UDOM) and nearby degraded landscape by assessing past and current vegetation and large mammal species’ occurrence.
Methodology:The past occurrence of mega-herbivores and their habitat was assessed using systematic literature survey, past vegetation maps and key informant interviews. EBSCOhost database and Google Scholar search engine were used for literature searching. A survey was conducted at UDOM area which is one of the remaining habitat patches in central Tanzania to examine present plant diversity.
Results:The baseline vegetation map of 1960 indicated that the study area was mainly Savanna woodland. Literature suggested that anthropogenic activities resulted into Land-Use Land-Cover Changes (LULCC) leading into wild animals’ extirpation leaving remnant populations in the surrounding protected areas. While the key informant interviews verified local loss of mega-herbivores, field data collected at UDOM campus in 2022 indicated the vegetation transformation to bushland dominated by Dichrostachys cinerea. The area’s past vegetation composition was 33% grasses, 29% herbs, 21% shrubs and 17% trees while the current was 18% grasses, 42% herbs, 30% shrubs and 10% trees.
Conclusion:The study revealed that central Tanzania hosted spectacular large mammal populations that interacted with the savanna which has recently been transformed to bushland. However, observed evidence on past existence of large mammals and recent elephants’ sightings at UDOM area indicate great potential for rewilding.
Implication for conservation:Reconstructing historical information of ecosystems is crucial for successful rewilding. Such information can guide conservation efforts aiming at reversing extinction and reestablishing connectivity of large herbivore population across ecosystems
Influence of duct configurations on the performance of solar-assisted heat pump dryer for drying tobacco leaves
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and Technologynadequate storage facilities and preservation techniques lead to a decrease in the quality of
agricultural products. Application of modern processing techniques has reduced post-harvest
losses of agricultural crops. Drying was done to lower the moisture content for preservation.
Tobacco drying requires massive amounts of wood, which has negative effects on the
environment such as pollution, deforestation, and desertification. In the present study, a solar-
assisted heat pump dryer (SAHPD) has been designed, fabricated and tested its performances
as an alternative drying technology for tobacco leaves. The hot air generated from the solar
collector and condenser unit of the heat pump was used as a source of heat in the drying
chamber. In this study, we investigated thermal performance of three duct configurations of the
SAHPD system (open, partially closed and completely closed) to establish the best
configuration for drying tobacco leaves where did not conducted before. The average drying
temperature was found to be 66, 64 and 60°C; the coefficient of performance of the heat pump
was 3.4, 3.2 and 3.0; the heat energy contribution from the condenser was 98.7, 98.5 and 98.3%;
and electrical energy consumption was 2.3, 2.8 and 2.6 kWh, for the open, partially and
completely closed systems, respectively. Based on these results, the open system demonstrated
the best performance. According to the study's findings, SAHPD has been shown to be an
energy-efficient method of drying tobacco leaves and environmentally friendly as opposed to
the conventional use of wood fuel, which results in environmental pollution, desertification,
and deforestation. Future studies should focus on inclusive investigation of the life cycle and
technoeconomi
Catalytic hydrothermal liquefaction of orange peels into biocrude: An optimization approach by central composite design
Get PDFThis research article was published in Journal of Analytical and Applied Pyrolysis Volume 173,2023Global instability, persistent increase in pump-price, inflation and depletion of fossil fuel resources amidst the continuous discharge of greenhouse gases from fossil fuels combustion call for urgent attention. The application of novel catalyst towards an improved biocrude production and enhanced biomass conversion are required for effective performance of hydrothermal liquefaction of biomass feedstocks. In the present study, iron supported carbon nanospheres (Fe/CNSs) catalyst has been developed using wet impregnation approach and explored for its catalytic potency in improving yield of biocrude using an optimization approach; central composite design. Hydrothermal liquefaction (HTL) was adopted as a process route where the catalyst dosage (3–6 wt%) and the reaction temperature (330–430 °C) were optimized on the constant weight of orange feedstock (10 g), reaction time of (15 mins) and solvents’ ratio of 3:1 (acetone to ethanol). The performance of the catalyst was found to be aided with the even dispersion of the Fe on the surfaces of the CNSs support and improved surface area. The effects of reaction temperature were observed to be more progressive on biocrude yield formation over the catalyst loading. The optimum biocrude yield, solid residue, biomass conversion and gas yield were obtained to be 71.09 wt%, 28.18 wt%, 71.82 wt% and 40.14 mL/g at 430 °C and 3 wt% catalyst loading. The obtained analysis of variance suggests a good correlation between the experimental and predicted data in all responses. The selectivity of Fe/CNSs catalyst to high yield of phenolics and aromatic compounds in the biocrude suggest that, the biocrude can be further be upgraded into transportation fuel through hydrodeoxygenation process. The findings have further suggested the viability of the developed Fe/CNSs as an effective catalyst for improved HTL products in a batch reactor