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Theoretical Considerations of Photonic Crystal Fiber with All Uniform-Sized Air Holes for Liquid Sensing
Get PDFThis research article was published by MDPI 2021A novel liquid-infiltrated photonic crystal fiber model applicable in liquid sensing for
different test liquids—water, ethanol and benzene—has been proposed. One core hole and three air
hole rings have been designed and a full vector finite element method has been used for numerical
investigation to give the best results in terms of relative sensitivity, confinement loss, power fraction,
dispersion, effective area, nonlinear coefficient, numerical aperture and V-Parameter. Specially, the
assessed relative sensitivities of the proposed fiber with water, ethanol and benzene are 94.26%,
95.82% and 99.58%, respectively, and low confinement losses of 1.52 × 10−11 dB/m with water,
1.21 × 10−12 dB/m with ethanol and 6.01 × 10−16 dB/m with benzene, at 1.0 μm operating wave-
length. This novel PCF design is considered simple and can be easily fabricated for practical use,
and the assessed waveguide properties has determined the potential applicability in real liquid
sensing applications
Investigating Cutoff Technique for Improved Water Saving and Productivity in Furrow Irrigation System
Get PDFThis research article was published by Journal of Irrigation and Drainage Engineering in 2021The cutoff technique has not been adequately investigated despite being the most practiced among smallholder farmers. This study aimed at scenarios of improving water application efficiency, distribution uniformity, and productivity for the technique. Three cutoff treatments where water supply was stopped with the advance phases reaching 75%, 80%, and 90% of furrow length were investigated with eight irrigation events. Mean application efficiencies with significant difference (P0.05). The results demonstrated the 75% cutoff has the potential of saving water of up to 26% without compromising water productivity. It is recommended therefore that the 75% cutoff position of water supply be promoted among the smallholder farmers and that research studies should now intensify for less than 75% cutoff
Predicting uptake of a malignant catarrhal fever vaccine by pastoralists in northern Tanzania: Opportunities for improving livelihoods and ecosystem health
Get PDFThis research article was published in the Ecological Economics Volume 190, December 2021Malignant Catarhal Fever (MCF), caused by a virus transmitted from asymptomatic wildebeest, is a lethal disease
in cattle that threatens livestock-based livelihoods and food security in many areas of Africa. Many herd owners
reduce transmission risks by moving cattle away from infection hot-spots, but this imposes considerable eco-
nomic burdens on their households. The advent of a partially-protective vaccine for cattle opens up new options
for disease prevention. In a study of pastoral households in northern Tanzania, we use stated preference choice
modelling to investigate how pastoralists would likely respond to the availability of such a vaccine. We show a
high probability of likely vaccine uptake by herd owners, declining at higher vaccine costs. Acceptance increases
with more efficaceous vaccines, in situations where vaccinated cattle are ear-tagged, and where vaccine is
delivered through private vets. Through analysis of Normalized Density Vegetation Index (NDVI) data, we show
that the reported MCF incidence over 5 years is highest in areas where the mean and interannual varibility in
vegetative greeness is relatively low and where herds sizes are smaller. Trends towards lower rainfall and greater
landscape-level constraints on cattle movement suggest that MCF avoidance through traditional movement away
from wildebeest will become more challenging and that demand for an MCF vaccine will likely increase
Design and Simulation of Photonic Crystal Fiber for Liquid Sensing
Get PDFThis research article was published by MDPI 2021A simple hexagonal lattice photonic crystal fiber model with liquid-infiltrated core for
different liquids: water, ethanol and benzene, has been proposed. In the proposed structure, three
air hole rings are present in the cladding and three equal sized air holes are present in the core.
Numerical investigation of the proposed fiber has been performed using full vector finite element
method with anisotropic perfectly match layers, to show that the proposed simple structure exhibits
high relative sensitivity, high power fraction, relatively high birefringence, low chromatic dispersion,
low confinement loss, small effective area, and high nonlinear coefficient. All these properties have
been numerically investigated at a wider wavelength regime 0.6–1.8 μm within mostly the IR region.
Relative sensitivities of water, ethanol and benzene are obtained at 62.60%, 65.34% and 74.50%,
respectively, and the nonlinear coefficients are 69.4 W−1 km−1 for water, 73.8 W−1 km−1 for ethanol
and 95.4 W−1 km−1 for benzene, at 1.3 μm operating wavelength. The simple structure can be easily
fabricated for practical use, and assessment of its multiple waveguide properties has justified its
usage in real liquid detection
Development of a smart ugali cooker
Get PDFThis research article was published by International Journal of Advanced Technology and Engineering Exploration, Vol 8(75)Ugali is a thick porridge that is one of the popular staple foods in East Africa. Traditional methods of ugali preparation,
cooking, and consumption are described. Firewood has been used as the primary energy source followed by charcoal. In
East Africa, electricity grids have expanded and reached a wider network, which has opened opportunities for electric
cooking to domestic consumers, especially in urban that was previously dominated by charcoal, which is in scarce supply
due to government regulations on environmental conservation. In this project, the smart ugali cooker was designed and
developed to automate the process of cooking ugali in households which is faster, safer, and healthier. The smart Ugali
cooker is an automated kitchen appliance designed to boil the mixture of water and maize flour into a dough mixture
referred to as ugali. It consists of a driving motor, stirrer, flour dispenser, heat source, a cooking pan, a temperature
sensor that measures the temperature of the boiling water in the pan, and the control system (Arduino board). The device
has basic units that are a dispenser, stirring unit, electronic control unit, pan, and electric heater. These units were
fabricated and integrated to form the complete cooking device. Thereafter, the Arduino board was programmed to control
the cooking process. Cooking experiments were conducted, on the cooking duration and the texture of ugali based on
water to flour ratio. The results showed that ugali was cooked after ten minutes and the quality was good for
consumption. In recommendation, the rightful flour to water ratio must be applied to obtain the desired texture of ugal
Development of IoT based Security System for Fire Monitoring and Prevention in Tanzanian Industries
Get PDFA research article was published by International Journal of Advances in Scientific Research and Engineering (ijasre) Volume 7, Issue 12, December - 2021Over the past years, there have been great advances in ICTs which have led to the development of fire monitoring and prevention systems. Despite the existence of these solutions, fire incidents especially in Tanzanian have been a major problem in industries which leads to the destruction of materials and loss of lives. With the help of wireless sensor networks (WSN) and the internet of things (IoT), the monitoring and prevention of fire outbreaks become easy and reliable. The present work explores the existing fire monitoring and prevention systems and then, designs and develops an innovative security system for early fire monitoring andprevention in Tanzanian industries through the use of emerging technologies such as WSN and IoT. The results of the system evaluation shows that 88% of users were satisfied with its functionalities. This is because the system works in real-time and through the use of different sensors such as DHT sensor, MQ2 sensor, and Flame sensor to monitor humidity, temperature, smoke, flammable gasses, and fire outbreak in the different work areas. The use of the mobile application and cloud subsystem, the developed system can timely alert the users via their mobile phones on the status of the fire and different parameter
Below the Radar: Data, Narratives and the Politics of Irrigation in Sub-Saharan Africa
Get PDFThis research article published by Water Alternatives, Volume 14 | Issue 2, 2021Emerging narratives call for recognising and engaging constructively with small-scale farmers who have a leading role in shaping the current irrigation dynamics in sub-Saharan Africa. This paper explores whether new irrigation data can usefully inform these narratives. It argues that, for a variety of reasons, official irrigation data in sub-Saharan Africa fail to capture the full extent and diverse nature of irrigation and its rapid distributed growth over the last two decades. The paper investigates recent trends in the use of remote sensing methods to generate irrigation data; it examines the associated expectation that these techniques enable a better understanding of current irrigation developments and small-scale farmers’ roles. It reports on a pilot study that uses radar-based imagery and analysis to provide new insights into the extent of rice irrigated agriculture in three regions of Tanzania. We further stress that such mapping exercises remain grounded in a binary logic that separates 'irrigation' from other 'non-irrigated' landscape features. They can stem from, and reinforce, a conventional understanding of irrigation that is still influenced by colonial legacies of engineering design and agricultural modernisation. As farmers’ initiatives question this dominant view of irrigation, and in a policy context that is dominated by narratives of water scarcity, this means that new data may improve the visibility of water use by small-scale irrigators but may also leave them more exposed to restrictions favouring more powerful water users. The paper thus calls for moving away from a narrow debate on irrigation data and monitoring, and towards a holistic discussion of the nature of irrigation development in sub-Saharan Africa. This discussion is necessary to support a constructive engagement with farmer-led irrigation development; it is also challenging in that it involves facing entrenched vested interests and requires changes in development practices
Clustering and Fuzzy Logic-Based Demand-Side Management for Solar Microgrid Operation: Case Study of Ngurudoto Microgrid, Arusha, Tanzania
Get PDFThis research article published HindawiPermanent electricity availability should not be taken for granted since grid sustainability and reliability are at stake when there is no balance between supply and demand. This paper employs a load balancing demand-side management (DSM) approach based on fuzzy logic, considering the low energy users who have insignificant influence on system peaks. Through the K-means clustering algorithm, suitable candidates for DSM are identified, and the control mechanism is based on energy utilization and load priority. The results reveal that about 3.7 kW in power saving was achieved per month. This result indicates that, with a proper energy management strategy for an individual customer, almost a flatter load profile and power saving can be achieved
Fluoride contamination of selected food crops, domestic water, and milk consumed by communities around mount Meru in Northern Tanzania.
Get PDFThis research article published by Taylor & Francis Online, 2021This study assessed fluoride levels in domestic water, commonly consumed food crops, cow's, and human milk. Samples of vegetables were collected from farmer's home gardens, green banana from local markets, maize flour, and domestic water from households, while cow's and human (breast) milk were obtained from cows and lactating mothers. Fluoride levels were determined by using a fluoride ion-selective electrode. Fluoride levels were 0.03 ± 0.02 mg/kg in maize, In leafy vegetables the highest levels were found in nightshade 0.081 ± 0.008 mg/kg, while for banana varieties the highest levels were found in in East African highland 0.025 ± 0.004 mg/kg. Levels in cows and human breast milk were 0.34 ± 0.2 mg/L and 0.077 ± 0.06 mg/L, respectively. Levels in domestic and public tap water were 4.57 ± 0.4 mg/L and 4.74 ± 0.8 mg/L, respectively. Study provided useful knowledge of fluoride levels in several crops, milk, and domestic water
Optimized method for processing avocado seeds to improve selected nutrients and functional values
Get PDFThis research article published by J-STAGE, Volume 27 Issue 1, 2021The objective of this study was to develop an optimal processing technique capable of reducing antinutrients to acceptable levels, retain nutrients and functional values of avocado seeds for human consumption. Different processing conditions for probiotic fermentation, boiling and soaking techniques were studied to establish optimal processing conditions for the seeds. The antinutrients, antioxidant activity, total phenolics and selected nutrients of avocado seeds were analyzed using analytical standard methods. All processing techniques significantly (p < 0.05) reduced over 50% of antinutrients. The highest total phenolics and antioxidant activity (IC50) were 33.3 mgGAE/g and 0.8 mg/mL respectively which were observed at a fermentation temperature of 37 °C. Soaking and boiling reduced the analyzed minerals to about 30% whereas probiotic fermentation retained 100% of minerals analyzed, ascorbic acid and α-tocopherol. Moreover, probiotic fermentation demonstrated the best results in comparison to boiling and soaking thus, considered as an optimal processing method for improving nutritional and functional values of avocado seeds