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Exergy analysis and performance testing of a gravitational water vortex turbine runner for small hydropower plants: An Experimental Approach
Get PDFThis research article was published by Tanzania Journal of Science / Vol. 50 No. 3 (2024)Gravitational water vortex power plants (GWVPPs) have recently gained popularity due to
their low initial investment, simple design, ease of maintenance, and low head utilization.
However, the technology suffers from poor performance issues caused by the non-optimized
parameters of its crucial components, such as the runner. In this study, the performance of a
runner (16° blade-hub angle, six blades, and a curved blade profile) for a GWVPP was
experimentally examined. The study also employed an exergy analysis. The experimental
results revealed that the efficiency of the GWVPP system was in the range of 9.84% to
25.35%, the torque was in the range of 0.08 to 0.23 Nm, and the output power was in the range
of 2.96 to 7.33 W. Furthermore, an exergy analysis of the system showed an exergy efficiency
of 43.58%. Additionally, the error analysis of the GWVPP revealed ranges of 0.1 - 0.5 W for
power, 0.01 - 0.03 Nm for torque, and 1.3–3.1% for efficiency, suggesting that the
experimental setup and instrumentation of this study were reasonably accurate. Based on the
results, the new vortex runner and GWVPP system are recommended for energy generation in
low-head, low-flow small hydropower plants
Mobile-Based convolutional neural network model for the early identification of banana diseases
Get PDFThis research article was published by Smart Agricultural TechnologyThis study aimed to deploy a deep learning model in a mobile application for the early identification of Fusarium
Wilt and Black Sigatoka in bananas. In this paper, a Convolutional Neural Network (CNN) model for the clas-
sification of Black Sigatoka banana disease and Fusarium Wilt disease is assessed. A dataset of 27,360 images of
diseased and healthy banana leaves and stalks that were collected from the farms using a mobile phone camera
served as the training data for this model. An extra class of 407 images that are not of the banana plant
downloaded from the internet was used to help the model detect other images not of the banana plant. The CNN
model achieved an accuracy of 91.17 % and was deployed in a mobile application for the classification of the
diseases. This study shows that deep learning can be implemented and assist in the early identification of banana
diseases. The application could detect images of healthy and diseased banana leaves and stalks and images not of
the banana plant with a confidence score of more than 90 % in less than five seconds per image and provide
research-based mitigation recommendation
Evaluation of a point-of-use device used for autoantibody analysis and its potential for following microcystin leucine-arginine exposure
Get PDFThis research article was published in Frontiers in Sensors, Volume 5, 2024Introduction: Globally, the need for measuring exposure to algal toxins has become urgent due to ever-increasing reports of contamination in sea and freshwater, in shellfish and fish stocks and in aerosols.
Methods: To address this issue, we evaluated the potential of determining autoantibodies to a panel of biomarkers known to be elevated following exposure to the hepatotoxin microcystin leucine-arginine. The presence of autoantibodies, specific to four selected stress-response, metabolomic and chaperone biomarkers, namely, Heat shock protein 1, Triosephosphate isomerase, Peroxiredoxin 1 and Peroxiredoxin 2 was employed in screening 371 serum samples from microcystin-exposed individuals in Tanzania. In addition, the capacity of the LightDeck fluorescence-based detector, a point-of-use device, to monitor these autoantibody responses in comparison to enzyme-linked immunosorbent assay was evaluated.
Results: By using the determination of autoantibodies to this novel panel of biomarkers an altered response was observed following microcystin exposure, with levels generally upregulated. The presence of elevated levels of microcystin leucine-arginine in water, as well as in food sources in Tanzania, may potentially have significant health effects on the population.
Discussion: This novel biomarker panel may have potential for the detection of microcystin leucine-arginine exposure as well as various microcystin exposure-associated cancers (e.g., hepatocellular cancer and colorectal cancer). In addition, the utilisation of the LightDeck point-of-use device proved successful for the rapid analysis of this biomarker panel
Uranium Dissemination with Phosphate Fertilizers Globally: A Systematic Review with Focus on East Africa
Get PDFThis research article was published in the Journals Sustainability Volume 16, Issue 4, 2024Growing concern has been expressed about uranium (U) accumulation in agricultural soils
caused by the long-term application of mineral fertilizers. More than 80% of naturally occurring
U transfers from phosphate rock (PR), the raw material used in mineral fertilizer production, to
phosphorus (P) fertilizers. These fertilizers are then distributed on agricultural soils, where the U
could accumulate over time and become a risk to the environment. The objective of this work was to
review the reported content of U in P fertilizers, its potential dispersion in soils, and its uptake by
plants in different countries in the world as reported in the literature. The articles for this systematic
review were selected from the Scopus database published between 2003 and 2022. The preferred
reporting items for systematic reviews and meta-analyses (PRISMA) protocol were used. A total of
54 articles were assessed based on the standard inclusion and exclusion criteria. U concentrations
in P fertilizers, agricultural soil dissemination, and plant uptake for available data were obtained
and assessed. In order to compare a set of related data from the collected articles, box and whisker
plots showing the distribution of U in P fertilizers are presented by region. The results from the
reviewed articles show that the U concentrations in P fertilizer were in the range of 0.1–653 mg kg−1.
Interestingly, Minjingu P fertilizers from Tanzania, which are used in six East African countries,
showed the highest U concentrations (159 to 653 mg kg−1, average 390 mg kg−1). The reported
U concentrations for these fertilizers are, in fact, comparable to those of conventional low-grade
uranium deposits mined in Namibia and elsewhere. Additionally, approximately 96% of the reviewed
articles indicate that fertilized soil has higher U concentrations than non-fertilized soils, hinting at
a measurable effect of mineral fertilizer use. The review recommends U extraction during mineral
fertilizer production so that potential environmental risks can be reduced and U resources that would
otherwise be lost can be recovered and used to substitute conventional U mining elsewhere
The assessment of neuronal plasticity following sciatic nerve injuries in rats using electron microscopy and stereological methods
Get PDFThis research article was published in the Journal of Chemical NeuroanatomyThe transmission of signals to the cell body from injured axons induces significant alterations in primary sensory
neurons located in the ganglion tissue, the site of the perikaryon of the affected nerve fibers. Disruption of the
continuity between the proximal and distal ends leads to substantial adaptability in ganglion cells and induces
macrophage-like activity in the satellite cells. Research findings have demonstrated the plasticity of satellite cells
following injury. Satellite cells work together with sensory neurons to extend the interconnected surface area in
order to permit effective communication. The dynamic cellular environment within the ganglion undergoes
several alterations that ultimately lead to differentiation, transformation, or cell death. In addition to necrotic
and apoptotic cell morphology, phenomena such as histomorphometric alterations, including the development of
autophagic vacuoles, chromatolysis, cytosolic degeneration, and other changes, are frequently observed in cells
following injury. The use of electron microscopic and stereological techniques for assessing ganglia and nerve
fibers is considered a gold standard in terms of investigating neuropathic pain models, regenerative therapies,
some treatment methods, and quantifying the outcomes of pharmacological and bioengineering interventions.
Stereological techniques provide observer-independent and reliable results, which are particularly useful in the
quantitative assessment of three-dimensional structures from two-dimensional images. Employing the fraction ator and disector techniques within stereological methodologies yields unbiased data when assessing parameters
such as number. The fundamental concept underlying these methodologies involves ensuring that each part of
the structure under evaluation has an equal opportunity of being sampled. This review describes the stereological
and histomorphometric evaluation of dorsal root ganglion neurons and satellite cells following nerve injury
models
Radio Frequency Energy Harvesting for Underground Sensor Nodes: Possibilities and Challenges
Get PDFThis Journal was published by IEE Access 2024Radio frequency energy harvesting (RFEH) is considered as one of the possible and envi-
ronmentally friendly solution for energizing sensor devices and prolonging the lifetime of wireless sensor
networks (WSNs). Despite being studied and experimented in several environments where WSNs are
used, studies and experiments related to RFEH in underground wireless systems are limited to near-field
wireless power transfer (WPT), measurement of received signal strength, and current conduction. The goal
of this study is to examine the possibilities and challenges of actualizing RFEH in wireless underground
sensor networks (WUSNs). A radio-frequency (RF) spectral survey was conducted, and a comparison was
performed with similar surveys conducted worldwide to determine the generally available ambient RF
energy. Using the aboveground to underground (AG2UG) RF communication model, the signal path loss
was analyzed under varying conditions. By relating the ambient RF power and AG2UG signal path loss,
it was found nearly impossible to harvest ambient RF energy with the harvesting antenna buried within the
soil, as the best-case environment will require a rectenna with sensitivity of at least −62.75dBm. However
ambient RF energy can be harvested when the harvesting antenna is in free space, while the other components
are underground and will require a high sensitivity of at least −40 dBm. Another possibility for underground
RFEH is the use of a dedicated WPT device located 1m above the ground, transmitting at 20 dBm with the
RF energy harvester 30 cm below the soil surface with a sensitivity of at least -28.5 dBm.This work was supported by the Higher Education for Economic Transformation (HEET) Project funded by the Government
of the United Republic of Tanzania via the Ministry of Education, Science and Technology, and the Mbeya University of
Science and Technology.https://doi.org/10.1109/ACCESS.2024.338037
Prevalence and risk factors for Q fever, spotted fever grouprickettsioses, and typhus group rickettsioses in a pastoralistcommunity of northern Tanzania, 2016–2017
Get PDFA research article was published by Tropical Medicine & International Health, 2024Background: In northern Tanzania, Q fever, spotted fever group (SFG) rickettsioses,
and typhus group (TG) rickettsioses are common causes of febrile illness. We sought to
describe the prevalence and risk factors for these zoonoses in a pastoralist community.
Methods: Febrile patients ≥2 years old presenting to Endulen Hospital in the Ngorongoro
Conservation Area were enrolled from August 2016 through October 2017. Acute and convalescent blood samples were collected, and a questionnaire was administered. Sera
were tested by immunofluorescent antibody (IFA) IgG assays using Coxiella burnetii
(Phase II), Rickettsia africae, and Rickettsia typhi antigens. Serologic evidence of exposure
was defined by an IFA titre ≥1:64; probable cases by an acute IFA titre ≥1:128; and
confirmed cases by a ≥4-fold rise in titre between samples. Risk factors for exposure and
acute case status were evaluated.
Results: Of 228 participants, 99 (43.4%) were male and the median (interquartile range)
age was 27 (16–41) years. Among these, 117 (51.3%) had C. burnetii exposure, 74 (32.5%)
had probable Q fever, 176 (77.2%) had SFG Rickettsia exposure, 134 (58.8%) had probable
SFG rickettsioses, 11 (4.8%) had TG Rickettsia exposure, and 4 (1.8%) had probable TG
rickettsioses. Of 146 participants with paired sera, 1 (0.5%) had confirmed Q fever,
8 (5.5%) had confirmed SFG rickettsioses, and none had confirmed TG rickettsioses.
Livestock slaughter was associated with acute Q fever (adjusted odds ratio [OR] 2.54, 95%
confidence interval [CI] 1.38–4.76) and sheep slaughter with SFG rickettsioses case
(OR 4.63, 95% CI 1.08–23.50).
Discussion: Acute Q fever and SFG rickettsioses were detected in participants with
febrile illness. Exposures to C. burnetii and to SFG Rickettsia were highly prevalent, and
interactions with livestock were associated with increased odds of illness with both path-
ogens. Further characterisation of the burden and risks for these diseases is warranted
Exploring the nutritional potentials of wild Vigna legume species for neo-domestication prospects
Get PDFThis research article was published by Cambridge University Press, 2024Projected increases in human population suggest that 70% more food will be needed in the near future, this makes it imperative to search for alternative food and feed sources for human and animal nutrition to feed the exponentially growing human population. According to the FAO 2019 report, the immense challenge of achieving the Zero Hunger target by 2030 is persistent. Exploring the unexplored, refining unrefined traits, cultivating the uncultivated, and popularizing the unpopular remain the most adequate steps proposed by researchers to achieve the domestication of the undomesticated for food and nutrition security. In that line of thought, this study explored the proximate composition of 87 accessions of four wild unexplored Vigna species (V. racemosa, V. ambacensis, V. reticulata, V. vexillata) in order to reveal information leading to their future domestication and utilization. Standard procedures and methods approved by the Association of Official Analytical Chemists were used in carrying out the proximate composition (%protein, %lipid, %fibre, %ash and % moisture and % carbohydrate) of the wild Vigna legumes. The study revealed that the wild Vigna species possess a large variation range of nutrient characteristics which could be exploited in the improvement of domesticated species or guide their domestication. It was also found that some individual wild accessions have higher nutrient, content as compared with domesticated ones which could be advantageous for bio-fortification or domestication. Indications relating to the candidate accessions favourable for do
Mathematical models for vehicular carbon dioxide emission
Get PDFThe increasing demand for transportation due to a growing global population has led to more
vehicles on the road and increased use of fossil fuels, resulting in higher atmospheric carbon
dioxide (CO2) levels and contributing to global warming. Thus, adopting sustainable trans
portation practices is crucial for achieving climate change goals, specifically the reduction of
greenhouse gas emissions to mitigate global warming. This study presents a nonlinear mathe
matical model to analyze the dynamics and control of atmospheric CO2 concentration in rela
tion to vehicle emissions. The model is qualitatively analyzed to understand long-term system
behavior. Model parameters are calibrated using real-world data on world population, eco
nomic activities, atmospheric CO2, forest biomass, and vehicle numbers. Results describes the
dependence between vehicle CO2 emissions and atmospheric CO2 levels and impact human
population decline. Numerical simulations validate analytical findings, and global sensitivity
analysis explores the influence of various parameters on CO2 dynamics. An optimal control
problem is formulated and solved by using Pontryagin’s principle, establishing optimality con
ditions. Solving the problem reveals that reducing vehicle emissions, implementing reforesta
tion efforts, adopting green economy practices, and curbing fossil-fueled vehicle production
can cut atmosphericCO2 levels by 2.866%. Consequently, addressing climate change linked to
increased atmospheric CO2 concentration is achievable through these measures
Enhancements of Heat Islands in the Growing Cities in Developing Countries Due to Land Use Land Cover Changes and Climate Change: A Case of Babati-Tanzania
Get PDFThis research article was published by Open Journal of Ecology Volume 14, 2024Climate is changing no doubt, with anthropogenic activities considered as the main driver of the change. Flooding, drought and urban heat island (UHI) are some impacts of climate change (CC). Additionally, land use land cover change (LULCC) adds more pressure to the growing cities. Population is increasing with urban cities expected to accommodate the majority of the people while UHI is expected to increase with CC and LULCC. Adaption is the best option to minimize impacts of UHI; however, researchers are required to identify the cause, impacts and ways to cope with the impacts. Therefore, this study investigated how the Land Surface Temperature (LST) of Babati, a fast-growing town in Tanzania, is changing with CC and LULCC. Remote sensing was used with LULC classification, which was performed using a maximum likelihood algorithm, and LST retrieval involved computational formulas using bands R, NIR, and TIR. Results showed a rise in built-up areas, suggesting urbanization at the expense of farmlands and bare land. The LULCC together with global warming from 2002 to 2022 contributed to the increasing average LST by 0.7˚C signifying that more impacts are expected in the future under a business-as-usual scenario. The findings also indicate that higher vegetation density is associated with lower LST and vice versa. This relationship highlights the critical role of vegetation in regulating temperature and suggests that enhancing vegetation cover may be an effective strategy for mitigating urban heat. Improving agricultural practices as population increases and promoting sustainable urbanization in Babati and similar towns are necessary to mitigate UHI effects