East African Journal Of Science, Technology and Innovation
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Optimization of photovoltaic power output predictions: a comparative analysis of artificial neural network algorithms with varied hidden layers
Full text linkThis paper explores the impact of hidden layers in the prediction of the photovoltaic power output of a polycrystalline Photovoltaic module using an artificial neural network with four different algorithms: Levenberg-Marquardt optimization, Bayesian regression, scaled conjugate gradient and scaled resilient propagation. Error function estimations were designed in MATLAB software and trained between 1–20 hidden layers’ configurations. Solar irradiance, ambient temperature, module temperature, wind speed and relative humidity are the five inputs to the artificial neural network model. The predictability of the power output using the four algorithms at a varied number of hidden layers was investigated using a time series seasonal average data set of 631 points obtained under outdoor conditions. 70% of the data set was used for training while validation and testing used 15% each. Results showed that all algorithms exhibited commendable prediction performance across all algorithms, with average mean square errors of 0.03042, 0.02679, 0.078 and 0.0709 for Levenberg-Marquardt optimization, Bayesian regression, scaled conjugate gradient and scaled resilient propagation, respectively. High coefficients of determination further confirmed accuracy, with values of 0.98669 for Levenberg-Marquardt optimization, 0.98996 for Bayesian regression, 0.96046 for scaled conjugate gradient and 0.96541 for scaled resilient propagation. The Bayesian regression algorithm outperformed other algorithms. These findings offer valuable insights for enhancing PV system performance and promoting sustainable energy solutions dyes, D3 showed the best properties compared to D1 and D2 for dye-sensitized solar cell applications
Assessment of multi-stakeholder interactions and networks in the grape innovation system in Dodoma city, Tanzania
Full text linkScientists all over the world agree that the multi-stakeholder interaction embraced by the agricultural innovation systems (AIS) approach is critical for boosting agricultural development. Despite this important role of enhancing agricultural production, the concept of multi-stakeholder interactions is under studied in the grape innovation systems (GIS) in Tanzania. This study examined multi-stakeholder interactions and the perceived challenges influencing interactions in the GIS at the wards of Mpunguzi, Mbabala, and Hombolo in Dodoma City. Structured interview via interview schedule was used to collect the social network data from 277 and 116 sampled grape farmers and other respondents from the other eight stakeholder groups, respectively. Also, key informant interview and Focus Group Discussion were employed to collect the qualitative data. The findings showed that the multi-stakeholder interactions and networks in the GIS were limited. Also, farmers, consumers, processors, traders, and input suppliers, in particular, had not yet been empowered to articulate their demands regarding grape innovations. Moreover, the findings revealed that a lack of innovation platforms (x ̅ = 2.9), communication barriers (x ̅ = 2.4), insufficient financial resources (x ̅ = 2.4), and a lack of time (x ̅ = 2) were among the challenges scored high average mean to imply that they were seriously impeding interaction between stakeholders in the GIS. This study recommends that strong links be strengthened among all key stakeholders in the GIS, as they rely on one another to function and achieve the goals of improving grape production. Finally, the study encourages the Tanzanian government to adopt various financial resource mobilization strategies in order to collect money for establishing the innovation platforms and solve other obstacles were identified to have been inhibiting interactions among stakeholders
Theoretical investigation on co-sensitization of natural dyes for dye sensitized solar cells (dsscs) applications
Full text linkThis study reports the effect of co-sensitization of four dye molecules of 3,5,7-trihydroxy-2-(4-hydroxy-3-methoxyphenyl) chromen-4-one, 2-phenylchromen-4-one, betalains, and 2-descarboxy-betanidin from Senna singueana leaves, Begonia malabarica leaves, Bougainvillea glabra bract, and Celosia cristata flowers, respectively, for dye-sensitized solar cell applications. Co-sensitization was done by designing new dyes (D1, D2, and D3) by attaching molecules M2, M3, and M4 to molecule (M1). Moreover, the optimized molecular structures of the individuals and newly designed dyes were investigated through density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations by using the GAUSSIAN 09 software package. The results on newly designed dyes as sensitizers on DSSC showed a reduction in the HOMO-LUMO energy gap compared to the individual dyes. The newly co-sensitized dye molecules (D1, D2, and D3) were reported to have energy gap (E_g) of 2.29, 2.73, and 1.91 eV, respectively, which was very small compared to individual molecules (M1, M2, M3, and M4) with an energy gap of 2.88, 2.70, 3.12, and 2.34 eV respectively. Additionally, the maximum absorption spectra were extended up to 849.55 nm for newly dye D3 compared with 683.96 nm for the individual dye M4. Furthermore, the highest light harvesting efficiency (LHE) was changed from 0.5829 for individual dye (M1) up to 0.9582 for newly dye (D3). Thus, the energy band gap 〖(E〗g), the light harvesting efficiency (LHE), and absorption spectra of the newly designed dyes were enhanced compared to individual dyes. However, among the newly designed dyes, D3 showed the best properties compared to D1 and D2 for dye-sensitized solar cell applications
Assessment of factors influencing adoption of tomato post-harvest loss-reduction technologies in Kaduna state, Nigeria
Full text linkThe Nigerian government\u27s policy on agriculture supports productivity enhancements, yet tomato production is constrained by post-harvest losses of up to over 45%. 420 tomato farmers were selected for study in Kaduna State, Nigeria. Multinomial Logit Model was used to determine factors influencing losses while factors influencing adoption and intensity were modelled using Tobit. The results showed the adoption rate of (new technologies) RP was 3.57%, CS = 0.47%, RT = 0.71%, MD =0.71%, CD = 100%. Adoption rate of (traditional method) raffia basket was 100%. For farmers, the highest source of losses was those in storage (70.5%), followed by farm level (14.5%). Results on factors influencing PHL showed that in transit, Modern Technology accentuated losses (p<0.10), while Car/truck ownership mitigated losses (p<0.01) In storage, Modern Technology (p<0.05), Farm Distance (p<0.05), Farm Size (p<0.10), and Own Car/truck ownership (p<0.10) mitigated losses, while only Multiple Cropping (p<0.05) accentuated losses. In marketing, education (p<0.05), modern technology (p<0.10), multiple cropping (P<0.10), and credit access (P<0.10) accentuated losses while age of farmer (p<0.10), years of technology adoption (p<0.10), farm size (p<0.10), and wealth status of farmer (p<0.05) mitigated losses. The results factors influencing adoption and adoption intensity of PHL-reducing technology show that Education (p<0.05), Age (p<0.10), Extension (p<0.10), CS_Information_Sources (p<0.01), RT_Information_Sources (p<0.01), MD_Information_Sources (p<0.05), Labour_sourcesT (p<0.01), Credit_sourcesT (p<0.10), and Farm_Size (p<0.01) were positive and had a significant influence. Education had a quadratic (Education2) negative influence on adoption of PHL reducing technologies. In conclusion, extension services exposure, large farm holding, and multiple information sources positively influenced adoption of post-harvest loss reduction technologies. The field survey also showed a 100% willingness of the farmers to adopt improved/modern technologies. The study recommended using PPP model to make these modern technologies and farm practices within the financial reach of farmers to mitigate post-harvest losses
Assessment of ICT services using the Information Technology Infrastructure Library Framework at Muhimbili University of Health and Allied Sciences, Tanzania
Full text linkAn increasing enrolment of students and demand for flexible delivery modalities in higher education calls for an urgent digital transformation in this sector. In addition, emerging global wicked challenges demand the appropriate use of information and communication technologies (ICT) to address them; for instance, the COVID-19 pandemic has accelerated the adoption of digital teaching, learning and transformation of educational services in higher learning institutions (HLIs). This study assessed ICT infrastructure, systems and services at the Muhimbili University of Health and Allied Sciences (MUHAS) in Tanzania using the Information Technology Infrastructure Library (ITIL) framework. This qualitative study used desk reviews of data obtained from interviews, system walkthroughs, document reviews and consultative meetings. The study used data from an assessment conducted between February 2017 and August 2021. The assessment found that MUHAS provides various ICT infrastructures and services, with a rapidly increasing demand for ICT services. A total of 84 ICT services at MUHAS were mapped and grouped as "Customer-facing" or "Supporting". The services were also categorised as "Core", "Enabling", or "Enhancing". The ICT services were at different maturity levels depending on the duration of their demands, requirements, capacity, usage, and availability of the required resources. Various educational technologies such as an eLearning platform, video conferencing systems, student management and assessment systems were used to enhance teaching, learning and progress tracking. This paper presents the experience of using the ITIL framework in assessing ICT infrastructure, systems and services at a university in Tanzania. It provides information on the services catalogue and its organisation as well as strengths, weaknesses, challenges and opportunities for using ICT in transforming university functions. In addition, this study informs other HLIs on similar assessments and strategic organisation of their ICT services in resource-constrained settings
Assessment of the change in the conformation and content of collagen of the goat skin due to different unhairing process
Full text linkRecently, more attention has paid to the reduction of environmental pollution due to leather processing, the beamhouse step especially unhairing part has been named as the one which contribute high pollutants in the total industrial waste. Therefore, different types of unhairing have been studied intending to reduce waste produced by unhairing step, however, no more findings on the influence of those alternatives to the collagen of the skin which determine the features of the leather. This study explores the impacts of those unhairing alternatives to the collagen of the skin. The shrinkage temperature values were lower as compared to that of raw skin sample, where oxidative unhaired skin, shows high difference (50.50C) from raw skin sample which was 64.90C. There were no significant differences in the hydroxyproline concentration between unhairing, this was due to triple helix structure of the collagen which make it more stable and not easily destroyed by unhairing chemicals. FT-IR results shows the differences in intensity (percentage) for side chain of collagen, where raw sample was 99.67%, oxidative was 90.83% while for conventional, hair saves and painting were 97.38%, 97.93% and 96.02% respectively. The stretching of N-H bond and bending for C-N bond for amide II, displays vibrations with wavenumber of 1519.20cm-1 for oxidative unhaired wet blue, as compared to other unhaired wet blue and raw skin sample which reads at 1539.20cm-1. The small differences in strength of the leather produced were associated with the change in the side chain intensity and conformation of collagen. The strength properties of the leather do not depend only on the concentration of the collagen but also on the proper packing of the collagen structures. The disturbance occurs to the hierarchical network of the collagen was reflected in the physical properties of the leather
A SmartTB: An Integrated Digital Patient-Centric Tool for Promoting Adherence to Treatment among People Living with TB in Tanzania
No full textTuberculosis (TB) is one of the most common killer diseases in Tanzania. The WHO report shows that a person infected with TB bacteria can be treated and prevented. During treatment, TB patients are required to visit a health facility to take medication. A 6-month course of drug treatment has been shown to successfully treat approximately 85% of infected individuals and reduce transmission of the disease. Despite this, there is a high rate of TB patients who discontinue treatment, consequently forgetting to visit the clinics at the required appointments to take medication. In this context, TB patients remain ill for a long time, which leads to drug-resistant TB. In addition, DOT nurses have difficulty identifying TB patients who miss a dose and are therefore unable to follow up by phone or home visits. This results in poor reporting that delays decision-making for TB management. The application of digital technologies such as artificial intelligence in healthcare has shown potential in healthcare services, including TB treatment and monitoring. In an effort to improve and maintain the quality of TB care, we have developed an integrated digital patient-centric tool called SmartTB that promotes treatment adherence among people living with TB in Tanzania and supports real-time reporting and monitoring. Using the agile methodology, requirements analysis was acquired from three hospitals in Tanzania, and user acceptance testing was implemented to validate the performance of the system before launch. The validation results show that SmartTB can improve TB treatment, monitoring, and reporting. Therefore, policymakers must consider the use and integratio
A Systematic Literature Review of Factors to Improve Tanzania\u27s Cross-Border E-Commerce Performance: Lessons from China
Full text linkThe study aimed at identifying factors which Tanzania can consider to improve its Cross-border e-commerce performance by reflecting on China’s experience. A systematic literature review methodology was applied, whereby 30 papers that have focused on analyzing influential factors of China’s Cross-border e-commerce from 2010 to 2023 were assessed. The results revealed that: Trade logistics and infrastructures, Government policies and support, Use of big data, Inter-Industry collaboration, Gross Domestic Product, Product diversification and low commodity prices are the factors which support China’s growth of Cross-border e-commerce
Imitation and Innovation of Practices in Science and Technology: Lessons from Asia and Europe for Tanzania
Full text linkImitation and innovation are often seen as opposing paths to advancement in science and technology. However, this paper argues that a balanced approach that combines both imitation and innovation could accelerate Tanzania\u27s development in these areas. This study has four specific objectives, namely, to assess: (1) The role of imitation and innovation of practices in science and technology; (2) Challenges that Tanzania faces in imitation and innovation of practices in science and technology; (3) Lessons for Tanzania in imitation and innovation in science and technology from Asia and Europe; and, (4) Strategies that Tanzania may use to benefit from imitation and innovation in science and technology lessons from Asia and Europe. By reviewing the literature on the interplay between imitation and innovation in Asia and Europe, the paper demonstrates how these regions have used both strategies to achieve rapid development in their science and technology sectors. The study found that imitation and innovation are important drivers of economic development for countries. Asia and Europe adapted strategies such as copycat, frugality, social innovation, the role of knowledge and technology transfer, innovation ecosystems, strong institutions, adapted disruption, balancing exploration and exploitation, systems of innovation, and intellectual properties for steering their development. For Tanzania, the paper recommends learning from the success of Asian countries like Japan and South Korea in imitating and improving their technology, as well as European countries like Germany and Sweden in cultivating an education culture that values innovation while taking advantage of the latest technologies and best practices from other countries. However, shortage of funding in the education system, poor infrastructure, lack of skilled workforce, and limited research and development might hamper the imitation and innovation in science and technology in Tanzania. Current government efforts are geared towards removing these bottlenecks
Formulation, acceptability, and chemical characteristics of mango nectar enriched with moringa moringa oleifera, lam leaves extract
Full text linkMango and Moringa are nutrient-dense foods. This study examined two mango varieties (apple and Tommy Atkin) for nectar production fortifying with Moringa leaf extract to reduce postharvest losses, food insecurity, and malnutrition. Post-harvest mango losses are high in Kenya (40-50%) and affects farmers\u27 income and the environment and if processed into mango nectar, can address postharvest losses (PHL). Mango nectar is rich in vitamins and minerals but lacks adequate micronutrients (calcium, iron, and zinc). Moringa oliefera leaves are nutrient-rich and adding moringa leaf extract to mango nectar improves its nutrition. This study intended to blend mango nectar with moringa leaf extract. The developed product contained 25% mango pulp and aqueous solutions of moringa leaf extract (F1, F2, F3, F4, F5, F6, F7, and F8): 0%, 10%, 12.5%, and 15%, respectively. The nectar was pasteurized at 70°C for 10 min and was analyzed for sensory evaluation, proximate composition, vitamin A, and mineral content (Fe, Ca, and Zn). F1 (control) and F3 (apple manga nectar blended with 12.5% moringa leaf extract), and F5 and F6 (Tommy Atkin mango nectar blended with 10% moringa leaf extract) were accepted. The formulated nectar differed in protein, fiber, ash, carbohydrate, energy, vitamin A, iron, calcium, zinc, color, odor, taste, texture, mouthfeel, and overall acceptability (p<0.05). Moisture and fat in nectar were not significantly different (p>0.05). Apple blended mango nectar had more fat, vitamin A, calcium, iron, and zinc than Tommy Atkin blended nectar: 1.07 and 0.60%, 8.68 and 6.91mg/100g, 39.89 and 34.26 mg/100g, 3.14 and 2.01mg/100g, and 8.85 and 7.19mg/100g. However, Tommy Atkin blended nectar had more fiber, protein, and energy. Therefore, moringa leaf extract can be utilized to fortify ood and beverages