Digital Commons Network^™

Impact Of Zn And W Doping Levels On Properties Of Thermochromic Vo2-Based Thin Films, Haji F. Haji, Margaret E. Samiji, Nuru R. Mlyuka

Tanzania Journal of Science

DC magnetron sputtering at a substrate temperature of 425 °C was used to successfully deposit W/Zn-doped VO2 thin films on soda lime glass (SLG) substrates. The aim was to investigate the influence of Zn doping levels on the transition temperature ( ), luminous transmittance (Tlum) and solar transmittance modulation (ΔTsol) of VO2-based thin films. UV/VIS/NIR spectrometer, X-ray Diffraction (XRD), Atomic Force Microscope (AFM), and Rutherford Backscattering Spectroscopy (RBS) were used to characterise the thin films. It was revealed that W/Zn co-doped VO2 thin films with ~ 10.8 at.% Zn showed a luminous transmittance of ~ 40.4%, with excellent solar transmittance …

Digitisation Of Classical Exercise Practices With Stack: Management Of Large Mathematics Classes In Higher Education Institutions, Idrissa S. Amour, Fatuma Simba, Septimi Kitta, Abdi T. Abdalla

Tanzania Journal of Science

Management of large classes’ tutorials is a known problem in Mathematics. Engineering mathematics classes enrol around 1000 students at the University of Dar es Salaam. For effective learning, each tutorial session should register not more than 40 students. This requires at least 25 sessions of tutorials per week, which may not be feasible due to both scarce human resources and venues. In this work, we developed online Mathematics exercises based on the System for Teaching and Assessment using Computer Algebra Kernel (STACK). About 300 STACK questions in linear algebra, calculus, complex numbers, and numerical analysis were constructed for weekly tutorials …

Pseudo-Allergies In The Emergency Department: A Common Misdiagnosis Of Hypersensitivity Type 1 Allergic Reaction, Akram M. Eraky, Alisha Wright, Douglas Mcdonald

GME Publications

Type-1 hypersensitivity reaction represents an acute IgE-mediated reaction that can cause life-threatening conditions, such as anaphylactic shock, angioedema, and airway obstruction. Other reactions that can mimic type-1 hypersensitivity reactions include IgE-independent mast cell degranulation, bradykinin-mediated reactions, leukotrienes-mediated reactions, and pseudo-allergies. We use the term pseudo-allergy in this article for histamine-mediated reactions that are mast cell-independent. We did not discuss pseudo-allergic reactions that are not acute or life-threatening, such as celiac disease, Heiner’s syndrome, eosinophilic esophagitis, and food protein-induced enterocolitis in our article because the emergency department is not the primary location to diagnose or treat these reactions. Herein, we present …

Sexual Risk-Taking Behavior Amongst Emerging Adults In A Tertiary Institution Of Learning In Coastal Kenya: A Qualitative Study Of Stakeholders’ Perspectives Using Causal Loop Mapping, Stevenson K. Chea, Vincent A. Kagonya, Eunice A. Oyugi, Carophine Nasambu, Isaac Menza, Fauz Ibrahim, Osman Abdullahi, Alice Anika, Amin S. Hassan, Amina Abubakar

Institute for Human Development, East Africa

Background It is known from previous studies that university students in sub-Saharan Africa (sSA) engage in sexual risk-taking behaviour (SRTB). However, there is paucity of data on factors contributing to SRTB among university students (emerging adults) at the Kenyan Coast thus hindering intervention planning. This study seeks to provide an in-depth qualitative understanding of the factors contributing to SRTB and their interconnectedness among university students at the Kenyan Coast combining qualitative research with a systems thinking approach.

Methods Using the ecological model, and employing in-depth interviews, we explored the perceptions of twenty-six key informants (twenty-one emerging adults and five other …

A Review Of Information Behavior Research At Home And Abroad, Yang Zhao, Tingxiao Wen

Journal of Scientific Information Research

[Purpose/significance]Information activities in the new network environment are an important part of users' daily behavior. Studying information behavior can better understand the relationship between users and information, so as to promote the development and utilization of information resources and maximize the value of information. [Method/process]Conduct keyword statistical analysis and co-word network analysis on the research papers of information behavior at home and abroad, systematically sort out the research topics of information behavior, and refine the research views.[Result/conclusion]The research on information behavior mainly focuses on the theoretical basis exploration and model construction, information behavior analysis of specific situations and specific users …

Environment And Sustainability: October 2023, Environment And Sustainability, Office Of The President

Environment and Sustainability Archives

• Replacing diesel with biomass for boiler at AKUH Nairobi,

• Monthly Movie Hour starting from October

• Paper savings from ICT optimisations

• All-vegetarian catering menu

• Zero-waste beach cleanup drive

• Sustainable Events Training

• Launch of 2023 President’s Challenge for Climate Solutions

• And much more…

Exploring The African Regional Human Rights Standards As The Basis For An Enabling Environment For Self-Managed Abortion, Lucia Berro Pizzarossa, Michelle Maziwisa, Ebenezer Durojaye

Washington and Lee Journal of Civil Rights and Social Justice

Self-managed abortion holds great promise to save lives and promote reproductive autonomy, particularly in Africa. Indeed, the African region records very high numbers of unsafe abortions, and the burden of abortion-related mortality is the highest globally. Abortion remains generally criminalized in violation of numerous internationally and regionally recognized human rights standards. The advent of abortion medicines and the increased grassroots energy geared towards curbing the harms of unsafe abortion evince medical abortion holds great promise for revolutionizing people’s access to high-quality reproductive care. This study discusses regional human rights frameworks, policy, case law, and a few representative domestic legislative frameworks …

Improving The Discharge Process In A Post-Acute Care, Skilled Nursing Facility To Decrease Hospital Readmissions, Shantoria W. Parker

Doctor of Nursing Practice Scholarly Projects

Problem: Older adults recently discharged from a skilled nursing facility (SNF) (often referred to as short-stay facilities) experience a period of vulnerability while transitioning back into the community, placing them at increased risk of adverse events, including hospital readmissions (Anderson et al., 2021). Completing a timely appointment (within 7 days) with primary care providers following discharge into the community reduces patients’ risk of preventable hospital readmissions (RHI, 2023) through interventions aimed at promoting coordinated care and safe transitions (Patel et al., 2019). However, more than 50% of readmitted patients failed to visit a primary care provider's (PCP) office between SNF …

Community Participation In Ngo Funded Classroom Construction And Water Supply Projects In Kibaha District, Tanzania, Mrisho M. Malipula, Mangi J. Ezekiel

BISNIS & BIROKRASI: Jurnal Ilmu Administrasi dan Organisasi

Community participation in development projects has been sustained rhetoric despite the rise of NGOs, which are regarded as efficient in affording participatory development practices. This article examines the nature and level of community participation in classroom construction and water supply projects implemented in partnership with NGOs in Tanzania. It examines community participation at different stages of the project cycle, the costs and benefits of motivational effect on community members' participation, the contribution of the sense of ownership and sustenance on community participation, as well as how community participation in development projects can be enhanced. Face-to-face interviews with 122 participants and …

Aquaculture In Hydropower Reservoirs, Racheal Macharia

Tanzania Journal of Engineering and Technology (TJET)

There is an undoubtedly existing relationship between water, energy, and food and their interaction with the natural environment and mankind. Climate change is the talk of the day in global development discussions as it intensifies water shortages, energy, poverty, food shortages, and environmental degradation. Currently, most of the hydropower dams constructed in Africa are majorly built to store water for agricultural purposes, control flooding, and generate electricity. Notable projects include the seven forks hydropower stations located on the Tana River in Kenya; Aswan high dam in Egypt; Grand Renaissance dam in Ethiopia; Kariba dam in Zimbabwe and Akosombo in Ghana. …

Designing A Model Of Solar Photovoltaic Water Pumping System For Off-Grid Localities In Tanzania, Imani Mruma

Tanzania Journal of Engineering and Technology (TJET)

Modeling of photovoltaic (PV) water pumping system for rural water localities is vital especially in these modern days, in Tanzania. This is due to the rise of high number of solar-powered rural water projects constructed lacking appropriate design. The fate result into poor and substandard projects delivering below expectations. Kikombo Solar Water Project situated in Dodoma; Tanzania is one among poorly designed solar project chosen as a case study to validate proposed model. The main problem of Kikombo project is unsatisfactory amount of water from domestic points to satisfy population demand. This matter has been raised by pumping-station attendants and …

Mppt Dc-Dc Buck-Boost Converter For Off Grid Hybrid Solar-Wind Battery System In Ikuza Island, Tanzania, Aviti Thadei Mushi

Tanzania Journal of Engineering and Technology (TJET)

Ikuza Island in Kagera-Tanzania faces lack of electricity due to cost challenges of extending the grid by marine cables and other transmission facilities. These makes such endeavour not appealing to the supply authority due to those higher charges. Therefore, this paper undertakes to design hybrid renewable energy sources for the island by specifically focusing on the buck-boost converter for the energy conversion from these renewable resources. The design of the bidirectional buck-boost converter for maximum power point tracking in off-grid hybrid renewable energy systems is multifaceted due to the inhomogeneity nature of the renewable energy sources. The bidirectional buck-boost converter, …

Assessment Of Spatial Variability Of Groundwater Potential Using Remote Sensing And Gis-Based-Criteria Evaluation For Dar Es Salaam, Tanzania, Augustina Alexander

Tanzania Journal of Engineering and Technology (TJET)

Groundwater is an important resource for the continuous provision of water supply in both urban and rural areas. Lack of enough knowledge about the spatial variability of groundwater potential zones (GWPZS) has a negative impact on groundwater extraction development and management and may result into over exploitation. In this study, analytic hierarchy approach (AHP)-coupled with multi criteria decision analysis (MCDA) and GIS techniques were employed to integrate hydrogeological, geological as well as topographical data to assess spatial variability of groundwater potential zones of Dar es Salaam city. Seven thematic layers such as lithology, slope, land-use, lineament, drainage, soil, and rainfall …

Extraction And Characterization Of Fibres From The Bark Of Ficus Nekbudu Tree, Liberato V Haule

Tanzania Journal of Engineering and Technology (TJET)

This paper investigates the extraction and characterization of fibres from the bark of the ficus nekbudu tree. The Ficus Nekbudu Fibres (FNF) was extracted from the bark by retting in water and then treatment with sodium hydroxide solution. The extracted FNF was analysed for chemical composition, physical, tensile, surface, structural and thermal stability properties. Findings on the chemical composition indicated that FNF has cellulose (49.9 %), lignin (13.4%), ash (7.1%) and water content (8.1%). From the physical investigation it was found that FNF has density (1.42 ± 0.005 g/cm3) and moisture regain (9.2 ±0.3%). From mechanical investigation it was found …

Designing A Cylindrical Capacitive Based Sensor For Monitoring The Table Salt’S Moisture Content During Iodization, Mwajuma Lungo

Tanzania Journal of Engineering and Technology (TJET)

Coaxial cylinder capacitive moisture sensor for determination of moisture content of table salts has been fabricated. The CMS method for determination of moisture content of table salts overcomes the effect of evaporation of iodine in table salt which results from heating in the oven drying method. The CMS overcomes the polarization effect result from the resistive methods of moisture content determination and it is non expensive to construct and it has high accuracy since measurements involves programming system in interpretation of the results. In this research, moisture content sensor based on capacitive principal created using two coaxial cylinders with height …

Comparison Of End-Point Energies Of Bremsstrahlung Photons From 28 Ghz Ecr Ion Source In Three Measurement Locations, Mwingereza John Kumwenda Dr

Tanzania Journal of Engineering and Technology (TJET)

Bremsstrahlung photons measurement show elevated energy emission beyond critical energy in 28-GHz ECR and its nature is not revealed. Thus, the aim of this study is to unveil the nature of high end-point energies at the three measurement locations. Bremsstrahlung photons from a 28-GHz ECR ion source were measured at Busan center of Korean Basic Science Institute (KBSI). The gamma-ray detection system consists of three round type NaI(Tl) scintillation detectors placed 62 cm radially from the beam axis at the three measurement locations namely injection, centre and extraction sides of an ECR ion source, and a NaI(Tl) scintillation detector placed …

Renewable Energy Potential Assessment For Improving Electric Power Availability In Urban Area: A Case Of Msigani Ward In Ubungo Municipal, Tanzania, Respicius Kiiza

Tanzania Journal of Engineering and Technology (TJET)

The demand for electricity in urban areas of the developing countries like Tanzania is increasing rapidly due to factors such as increasing population, expansion of economic activities and industrialization. Msigani ward is one of the fourteen (14) administrative urban wards in Ubungo Municipal, Dar es Salaam, located at latitude 6.8031 oS and longitude 39.1188 oE. Recently, there has been observed increase in power demand in this ward. This in turn has caused a supply deficit that sometimes led to large number of interruptions caused by frequent power outage and load shedding. The total capacity of the national grid is limited …

Assessing Spatio-Temporal Variations And Trends Of Rainfall Over Somalia From 1991 To 2020, Paul Ts Limbu Sr

Tanzania Journal of Engineering and Technology (TJET)

This study aims to examine the spatiotemporal variability and trends of rainfall over Somalia using the Mann-Kendall (MK) test and Sen’s slope estimator to investigate the trend and magnitude of the rainfall changes and the arithmetic mean and coefficient of variation (CV) to examine the rainfall variability. To achieve this aim, the gridded monthly satellite rainfall datasets from Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) for the period between 1991 and 2020 were used. Results show that annual rainfall generally exhibits bimodal rainfall distribution, March to May (Gu) and September to November (Deyr), though southern coastal regions receive extended …

Human Capital Management Information System At The Nelson Mandela African Institution Of Science And Technology Of Tanzania: Challenges Encountered, Nicodemus S. Marcel, Oscar W. Tefurukwa

BISNIS & BIROKRASI: Jurnal Ilmu Administrasi dan Organisasi

In 2011, government institutions began utilizing HCMIS to reduce the manual workload of traditional administrative processes. The adoption of HCMIS in Tanzania is expected to increase efficiency by optimizing data accuracy, reducing costs, and eliminating paperwork. However, payroll losses continue to persist in the public sector. In 2018, the government incurred losses of Tanzania shillings (Tshs) 19.6 billion to 12,697 ghost workers. This study examines the challenges hindering the application of HCMIS in supporting selected human resource management (HRM) functions at the Nelson Mandela African Institution of Science and Technology (NM-AIST). This study applied Institutional Theory and Socio-Technical Theory as …

Application Of Mangrove Timber In Reinforcing Concrete, John K. Makunza Jkm

Tanzania Journal of Engineering and Technology (TJET)

Use of mangrove timber beams for supporting floor slabs in historic buildings in Zanzibar Stone Town is still applied although the available structural data on mangrove timber is inadequate. This concern has called for an investigation on the structural properties of mangrove timber, so that the information obtained could help to establish the structural strength of the existing floor slabs in historic buildings. Hence, mangrove timber specimens were sampled from Zanzibar, and tested in the laboratory for their strengths in tension, compression and shear. The test results showed that mangrove is a hardwood timber of strength class D70, the highest …

A Multitask Learning Framework For Pilot Decontamination In 5g Massive Mimo, Crallet Victor

Tanzania Journal of Engineering and Technology (TJET)

Reference signals enable the acquisition of channel state information (CSI) for purposes such as channel estimation, beam selection, precoding, and symbol detection in 5G massive multiple-input multiple output (MAMIMO) systems. Eventually, as more and more users and cells are added, orthogonal reference signals become few which leads to pilot contamination. Pilot contamination limits the performance and occurs when non-orthogonal reference signals occupy time-frequency resources that are alike. Learning-based techniques have been proposed to alleviate it. However, each can only learn to perform a single task namely pilot assignment, power allocation, pilot design, or de-noising for pilot decontamination. In addition, each …

Effects Of Bacillus Thuringiensis, Beauveria Bassiana, Neem, And A Tomato Inter-Crop On Diamondback Moth (Plutella Xylostella L.) (Lepidoptera: Plutellidae) In Tharaka-Nithi County, Kenya, Ceciliah N. Ngugi, Jesca N. Mbaka Mbaka, Hellen W. Muthengi

Tanzania Journal of Science

Cabbage (Brassica oleracea var. capitata) is an important crop in Kenya, ranked 3rd among the exotic vegetables. Diamondback moth (DBM) is a major cabbage pest that can cause a 100% loss in yield if not well managed. Farmers indiscriminately use synthetic pesticides associated with environmental, health, and pest resistance concerns to manage the DBM. To increase the availability of technologies for effective management of DBM in Kenya, three biopesticides; BioPower (Beauveria bassiana 1.0 x 108 CFUs/g), Dipel DF® (Bacillus thuringiensis subsp. kurstaki), Neemraj Super 3000 (Azadirachtin 0.3% EC), and a tomato inter-crop were evaluated. Cabbages (30 plants) spaced at 40 …

An Overlapped Sub-Array Hybrid Beamforming Architecture With Successive Interference Cancellation And Water-Filling In Massive Mimo Systems, Godwin Mruma Gadiel

Tanzania Journal of Science

Over the years, wireless communication has significantly improved the data rate of mobile users. The key drive behind this success is the technological advancement in wireless communication. In the physical layer, hybrid beamforming has revolutionized the way signal reaches the user by constructively adding the signal at the destination thus improving the performance. Many researchers works have proposed different algorithms to solve for optimal hybrid beamforming. However, there is no single algorithm that can achieve both high spectral efficiency and energy efficiency at the same time. This work proposes a hybrid algorithm that combines successive interference cancellation and water filling …

Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam

Tanzania Journal of Science

Organic pollutants in water have been a challenge and pose significant risks to human health. As a result, research efforts to eliminate these pollutants have been on the rise. Photocatalysis has shown incredible potential in water treatment containing organic pollutants since it is affordable and utilizes solar energy. Tin oxide ( ) has ardently been investigated as a photocatalyst for water treatment due to its remarkable properties such as; non-toxicity, and stability. However, its wide band gap and the tendency for some electrons and holes to recombine during its use have been cited to be among limiting factors affecting its …

Assessment Of The Offline Setup Correction Protocol And Thermoplastic Mask Use For Head And Neck Cancer Radiotherapy: A Single Institution Experience, Furahini Yoram, Nazima Dharsee, Khamza Maunda, Jumaa D. Kisukari, Geofrey F. Soko

Tanzania Journal of Science

This study assessed the efficiency of offline setup correction protocol and the use of a thermoplastic mask for head and neck cancer (HNC) patients treated with three-dimensional conformal radiotherapy at Ocean Road Cancer Institute. A prospective study was conducted from April to August 2021 to verify 62 patients’ treatment setup using an offline setup correction protocol while immobilized with a thermoplastic mask. Megavoltage images were matched with digitally reconstructed radiographs obtained during CT simulation to determine the gross set-up deviations. Box plots were used to show the deviations on three consecutive days of the first week and a successive weekly …

Effective Enhancement Of Post-Harvest Tomato Storage Through Wrapping Using Deacetylated Chitin Nanofibril-Plasticized Honey Films, Ngesa Ezekiel Mushi, Edina Meela, Divina Kaombe

Tanzania Journal of Science

As one of the most grown seasonal fruit, tomato is widely consumed for making food products, drugs and ornaments. However, poor post-harvest handling system, transport and storage facilities deteriorate the quality of tomato fruits resulting into post-harvest losses. These problems have been addressed by the use of nanotechnology in this study. The combination of a chitosan surface and the core shell chitin results into novel deacetylated chitin nanofibril (DeChNF) with good biological activity and mechanical strength. The effectiveness of the DeChNF films for food preservation as an alternative material to chitosan is investigated. The DeChNF with degree of acetylation (DA) …

Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai

Tanzania Journal of Science

Lake Natron Basin (LNB) forms part of the eastern branch of the East African Rift System (EARS) in Tanzania. The basin is endowed with thermal springs flowing towards the lake from the western, northwestern, southwestern and eastern parts. The western, northwestern and south-western thermal springs emanate from fractures in the basaltic rocks while in the east, they originate from the western flank of the Gelai volcano. There are limited studies on these springs, thus their geochemical differences and distributions of physicochemical parameters are not well understood. A hydrogeochemical study was conducted to interpret available geochemical data from the LNB springs, …

Mineralogy And Geochemical Characteristics Of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications For Industrial Applications, Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi

Tanzania Journal of Science

Kaolin is a commercial clay material composed of hydrated aluminosilicate mineral kaolinite and used in various industrial applications such as ceramics, paper, paints, refractories, fiberglass, plastics, cosmetics and pharmaceuticals. It is formed as a result of strong chemical weathering of crystalline and feldspar-rich rocks or hydrothermal alteration of granitic rocks at relatively low temperature and pressure conditions. The kaolin deposit of Matamba originated from the weathering of leucogabbro rock during the development of the African land surface. In view of highlighted properties, the mineralogy and chemical characteristics of the Matamba kaolin deposit were investigated to determine its industrial applications. As …

Design Of A Cooling System Integrated With Ultraviolet Light For Preservation Of Fruits And Vegetables At Variable Tropical Weather Conditions: A Case Study Of Arusha, Tanzania, John Pyuza Gunda, Alexander Pogrebnoi, Baraka Kichonge

Tanzania Journal of Science

Post-harvest losses of fruits and vegetables pose significant challenges, especially in tropical climates. This study introduces the development and performance evaluation of a solar-powered evaporative cooling storage system integrated with ultraviolet light (UV) designed for preservation of perishable fruits and vegetables. The cooling chamber supplied with ultraviolet lamp was developed using locally available materials such as sisal, sponge, and bricks. The performance of the system was evaluated in terms of air temperature decrease, relative humidity increase, and evaporative cooling power capacity both for sunny and cloudy tropical weather conditions. The study reveals that activating the UV light considerably extends the …

Wind Speed Forecasting Using Wavelet Analysis And Recurrent Artificial Neural Networks Based On Local Measurements In Singida Region, Tanzania, Rajabu J. Mangara, Mwingereza J. Kumwenda

Tanzania Journal of Science

High accuracy wind speed forecasting is essential for wind energy harvest and plays a significant role in wind farm management and grid integration. Wind speed is intermittent in nature, which makes the forecasting to be a big challenge. In the present study, three hybrid single-step wind speed forecasting techniques are proposed and tested by local measurement data in Singida region, Tanzania. The three techniques are based on Wavelet Analysis (WA), Back Propagation (BP) optimization algorithm, and Recurrent Neural Network (RNN). They are referred to as WA-RNN, BP-RNN, and WA-BP-RNN. The model results showed that WA-BP-RNN outperforms the other two proposed …