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Analysis Of The Current And Future Land Use/Land Cover Changes In Peri-Urban Areas Of Dar Es Salaam City, Tanzania Using Remote Sensing And Gis Techniques, Erick T Mnyali, Silvia F Materu

Tanzania Journal of Science

A rapid increase in population and urban development has direct impacts on the natural environment of peri-urban areas of big cities, especially in the developing countries. This study examined land use and land cover changes (LULCC) of peri-urban areas of Kinondoni Municipality in Dar es Salaam city for the period between 1999 and 2019 and predicted future changes by 2039. The specific objectives were to; (i) map the spatial-temporal land use and cover changes (ii) analyze settlements (built-up areas) patterns and factors influencing their changes (iii) predict changes that might happen for the next two decades. LULCC for 1999 to …

Environmental Noise Pollution And Its Impacts On The Hearing Ability Of Men And Women In Ilorin, Kwara State, Nigeria, Afolabi M. Tunde, Salamat Abdulquadri

Tanzania Journal of Science

Noise is an environmental disturbance that has harmful effects on the physiological and psychological lives of human beings and animals. This work examined the perceived health implications associated with noise pollution on both genders in Ilorin, Nigeria. It specifically identified the major sources of noise pollution, assessed noise pollution levels in the selected areas and determined the differences in the impacts of noise pollution on the health of both genders in Ilorin. A total of 384 respondents were sampled. Sound Level Meter (SLM) was used to ascertain the levels of noise in the study areas. Descriptive statistics and ANOVA were …

Effects Of Ripeness And Blending Speed On The Extraction Yield And Physical Chemical Properties Of Low Viscosity Banana Juice, Oscar Kibazohi, Victor V Matabura

Tanzania Journal of Science

Low viscosity banana juice can be extracted from banana by blending and pressing the resulted semi-solid pulp to separate the juice. This juice extraction technology is relatively new and further studies to understand key parameters for juice release is vital for scaling up production and commercialisation. This study, investigated the influence of blending speed and ripeness stage on banana juice yield using two banana cultivars; the East African highland banana (Mbile) and the exotic banana (Pisang awak). Types of sugars and organic acids in the juice were analysed using an HPLC. Changes with ripening of fruit firmness, juice pH and …

Analogue Sandbox Scaled Modelling Of Oblique And Orthogonal Extension Rifting In Rukwa Rift Basin, Tanzania, Tonny Ojok, John Bk Duot, Majorine Namaganda, Nasra Sadiki, Michael Msabi

Tanzania Journal of Science

Fault evolution in oblique and orthogonal rift systems in the brittle upper crust of the Rukwa rift basin was simulated using scaled sandbox modelling by varying the angle between the rift axis and the extension direction, α, through 45° and 90°, over a 10 cm displacement. The 45° oblique model exhibits a half-graben architecture bounded by a planar fault, intra-rift faults and a conjugate fault in some vertical sections. The map view of the model’s basin trends in the NW-SE direction, and is comparable with the Rukwa rift basin orientation. The 90° oblique model forms a basin structure which is …

Adaptive Sliding Mode Contouring Control Design Based On Reference Adjustment And Uncertainty Compensation For Feed Drive Systems, Mathew Renny Msukwa, Santos Kihwele

Tanzania Journal of Science

Industrial feed drive systems, particularly, ball-screw and lead-screw feed drives are among the dominating motion components in production and manufacturing industries. They operate around the clock at high speeds for coping with the rising production demands. Adversely, high-speed motions cause mechanical vibrations, high-energy consumption, and insufficient accuracy. Although there are many control strategies in the literature, such as sliding mode and model predictive controls, further research is necessary for precision enhancement and energy saving. This study focused on design of an adaptive sliding mode contouring control based on reference adjustment and uncertainty compensation for feed drive systems. A combined reference …

Modelling The Impact Of Undetected Cases On The Transmission Dynamics Of Covid-19, Herieth Rwezaura

Tanzania Journal of Science

The spread of COVID-19 globally has caused negative impacts to the public, making understanding the dynamics of transmission a necessity. Essential factors such as undetected cases, asymptomatic cases, and several non-pharmaceutical interventions have played significant roles in the spreading mechanism of COVID-19 in the human population. It is imperative to understand the significance of these factors in order to determine whether COVID-19 will be eradicated or will continue to persist in the population. A mathematical model is formulated to investigate the impacts of vaccination and several non-pharmaceutical interventions on the dynamics of a COVID-19 accounting for asymptomatic cases, detected (identified) …

Biodiesel Generation From Palm Kernel Biomass Via An In-Situ Transesterification Approach, Chikaodili D Ikechukwu, Ikhazuagbe H Ifijen, Nyaknno U. Udokpoh

Tanzania Journal of Science

This study investigated an in-situ transesterification of palm kernel biomass at variable reaction times (4 h, 5 h and 6 h) and catalyst loading (2 wt%, 3 wt.% and 5 wt.%). The biodiesel yields were observed to vary with these parameters. GC-MS analysis showed high fatty acid methyl esters (FAMEs) contents for all the prepared biodiesel samples (C-18:1, C-14:0, C-16:0, and C-18:0). 2 wt.% catalyst loading and 4 h reaction time were observed to be the best reaction conditions from the experimented parameters that gave the best biodiesel yield at 300 rpm mixing intensity. The in-situ method recorded a higher …

Application Of Faulkenberry (2018) Bayes Factor To A Balanced Two Way Analysis Of Variance With Random Effects, Onyeike D. Egburonu, Omotayo A. Abidoye

Tanzania Journal of Science

The Analysis of Variance technique estimates variance components by comparing their mean squares to their expected values. Nevertheless, this method could give variance component estimates that are found outside the parameter space, i.e. negative estimates. In a bid to overcome this deficiency, alternate approaches are essential, and likelihood-based approaches have become common over time. Bayesian techniques have also been proposed and Bayes factors developed for examining various models. We applied the Bayes factor proposed by Faulkenberry (2018) to a Balanced Two Way ANOVA under three (3) cases, namely Case 1: the levels of the two factors are fixed; Case 2: …

Mathematical Characterization Of Biological Control Of Cassava Pests Model, Yidiat O. Aderinto, Faith O. Ibiwoye, Michael O. Oke, Folashade M. Jimoh

Tanzania Journal of Science

Pests are major constraints to the effective growth and development of every crop through their damage, and can be controlled effectively by the use of their natural enemies which is referred to as the biological pest control. In this study, the biological control model of cassava pests through optimal control theory was presented in order to minimize the population of the pests and stabilize the natural enemies population so as not to affect the crop negatively. A mathematical model was formulated via the Lotka-Volterra model, and the model was characterized. The optimality system was established, the equilibrium point with its …

A Global Agenda For Advancing Freshwater Biodiversity Research, Alain Maasri, Sonja C. Jähnig, Hendrik Freitag, 93 Co-Authors

Biology Faculty Publications

Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.

The Negative Effects Of Cyberbullying Among Secondary School Adolescents In Tanzania, Hezron Zacharia Onditi, Jennifer Shapka

Journal of Humanities and Social Sciences

Cyberbullying and its associated consequences on children and adolescents has recently become a problem of global concern. Using phenomenological research design, this study explores the negative effects of cyberbullying on Tanzanian secondary school female and male adolescents. A total of 20 adolescents (50% female) in secondary schools (Form I to Form IV) who identified themselves as victims of cyberbullying were involved in the interview to share their lived experiences on the negative effects of cyberbullying. From thematic analysis, results indicated that, similar to their counterpart adolescents in the developed countries, Tanzanian female and male adolescents have experienced emotional, social, cognitive, …

Maris: Scalable Online Scenario Development Tool For Rangeland Conservancy Managers Using High Spatial-Temporal Resolution Carrying Capacity Maps And Livestock Market Data, L. G. J. Boerboom, R. O. Ohuru, A. G. Toxopeus, W. Nieuwenhuis, C. A. J. M. De Bie, P. K. Mwangi, M. L. Schouwenburg, R. L. G. Lemmens

IGC Proceedings (1977-2023)

Although the management of livestock numbers within the bounds of carrying capacity of African rangelands is a way to manage risks, both scientists and practitioners, caution against a momentary and local use of carrying capacity as a management indicator. Carrying capacity should be seen in wider spatial and temporal/seasonal context as well as in a social and economic context. Given the large numbers of conservancies across Kenya, and its Maasai Mara region in particular, with many more landowner members, it is difficult for conservancies’ managers to contextualize phenomena such as carrying capacity and market price over space and time.

We …

Pair Distribution Function Analysis And Electrochemical Performance Of Mesoporous Carbon Nanomaterials Synthesized Through Koh And Zncl2 Activation, Talam E. Kibona, Sarah Frisco, Maxwell W. Terban

Tanzania Journal of Science

Mesoporous carbon has been synthesized by activating carbonized biogas slurry residues with ZnCl2 and KOH simultaneously. The carbon to activating agent mass ratios were kept at 1:4, while the ZnCl2 to KOH mass ratio varied from 4:0, 3:1, 2:2, 1:3, to 0:4. The highest BET specific surface area of 361 m2 g-1, micropore surface area of 231 m2 g‒1, mesopore surface area of 125 m2 g‒1, and total pore volume of 0.23 cm3 g‒1 which amounted to 78% mesopore content, were obtained for the sample with 3:1 ZnCl2 to KOH mass ratio. Scanning electron microscope (SEM) images were acquired to …

Effects Of Refuge Prey On Stability Of The Prey-Predator Model Subject To Immigrants: A Mathematical Modelling Approach, Mussa Amos Stephano, Il Hyo Jung

Tanzania Journal of Science

Prey-predator system is enormously complex and nonlinear interaction between species. Such complexity regularly requires development of new approaches which involves more factors in analysis of its population dynamics. In this paper, we formulate a modified Lotka-Volterra model that incorporates factors such as refuge prey and immigrants. We investigate the effects of refuge prey and immigrants by varying the refuge factor, with and without immigrants. The results show that with Holling’s type I functional response, the proposed model is asymptotically convergent when a refuge prey factor is introduced. Moreover, with Holling’s type II functional response, the proposed mathematical model is unstable …

Analysing Climate Change Mitigation Policy Options In The Renewable Energy Sub-Sector In Tanzania, Ladislaus Kyaruzi, Patrick M Ndaki, Richard Ym Kangalawe

Tanzania Journal of Science

Public policies influence reduction of greenhouse gas emissions. Also the extent to which policies are developed and implemented can influence the achievement of the national, regional and international climate change mitigation policy framework in the renewable energy sub-sector. This paper provides a critical overview of key policy options influencing the development of renewable energy sub-sector through climate change mitigation policy options in Tanzania. Questionnaire surveys were used to collect primary data from 100 relevant experts who represented 64 organizations in Tanzania. Secondary data were collected by literature review. The state of climate change mitigation policy options in the renewable energy …

Impacts Of Wood Fuel Uses On Forest Cover: The Case Of Semiarid Areas In Northern Tanzania, Debora J Mahushi, Revocatus L Machunda, Talam E Kibona

Tanzania Journal of Science

Satellite images for the years 1987, 1997, 2002 and 2017, and questionnaire surveys were used to assess energy sources and demands as well as the impacts of wood fuel use to forest cover changes in Meru and Mwanga Districts. The major energy sources identified include cow dung cake, firewood, charcoal, liquefied petroleum gas and biogas. The total energy demands from these sources were 1400 (in Meru), 6289, 724 and 21 kg per day, respectively. The amount of biogas was not quantified since the reactors were constructed locally with no reading meter. Analysis from Landsat images showed variations in forest cover. …

Inversion–Free Iterative Method For Finding Symmetric Solution Of The Nonlinear Matrix Equation X-A^* X^Q A=I (Q≥2), Chacha Stephen Chacha

Tanzania Journal of Science

In this paper, we propose the inversion free iterative method to find symmetric solution of the nonlinear matrix equation  where  is an unknown symmetric solution,  is a given Hermitian matrix and  is a positive integer. The convergence of the proposed method is derived. Numerical examples demonstrate that the proposed iterative method is quite efficient and converges well when the initial guess is sufficiently close to the approximate solution. Keywords: Symmetric solution, nonlinear matrix equation, inversion free, iterative method.

Vulnerability And Responses Of Smallholder Farmers To Climate Change Effects In Semiarid Areas Of Bahi And Kongwa Districts, Tanzania, Helena Elias Myeya

Tanzania Journal of Science

This study examined the vulnerability and responses of smallholder farmers to climate change effects in Semiarid Areas of Bahi and Kongwa Districts. A total of 366 household heads were involved in this study. The study employed questionnaire, interviews and documentary review as data collection techniques. Archival data for temperature, rainfall and crop yields were collected for trend analysis. Descriptive and inferential statistics were used to analyse quantitative data, content analysis was employed to analyse qualitative data. Simple linear trend analysis and Mann Kendall were used to establish trends. The findings indicate that smallholder farmers in the study area have noted …

A Mathematical Analysis Of An In-Vivo Ebola Virus Transmission Dynamics Model, Seleman Ismail, Adeline Peter Mtunya

Tanzania Journal of Science

Ebola virus (EBOV) infection is a hemorrhagic and hazardous disease, which is among the most shocking threats to human health causing a large number of deaths. Currently, there are no approved curative therapies for the disease. In this study, a mathematical model for in-vivo Ebola virus transmission dynamics was analyzed. The analysis of the model mainly focused on the sensitivity of basic reproductive number,  pertaining to the model parameters. Particularly, the sensitivity indices of all parameters of  were computed by using the forward normalized sensitivity index method. The results showed that a slight change in the infection rate immensely influences …

Automated Detection Of Bilingual Obfuscated Abusive Words On Social Media Forums: A Case Of Swahili And English Texts, Geofrey Njovangwa, Godfrey Justo

Tanzania Journal of Science

The usage of social media has exponentially grown in recent years leaving the users with no limitations on misusing the platforms through abusive contents as deemed fit to them. This exacerbates abusive words exposure to innocent users, especially in social media forums, including children. In an attempt to alleviate the problem of abusive words proliferation on social media, researchers have proposed different methods to help deal with variants of the abusive words; however, obfuscated abusive words detection still poses challenges. A method that utilizes a combination of rule based approach and character percentage matching techniques is proposed to improve the …

Women’S Empowerment For Demographic Issues And Conflicts In African Pastoralist Societies, M. R. Cevallos, P. Manzano

IGC Proceedings (1977-2023)

Widespread conflict is a recurring issue in African pastoralist societies. While its roots are debated, there is a missing link with prevailing poverty among communities and particularly among women. We here apply a gender perspective to establish a hypothesis on the role of women in pastoralist conflicts.

The existing polygynic system establishes a violent frame for pastoralist women, who would be sold at increasingly early ages to provide in turn enough resources for furnishing the dowry needed by their brothers. The control on them would thereby be transferred from their own families to their husband and his family, where they …

Men’S Comfort In Distributing Or Receiving Hiv Self-Test Kits From Close Male Social Network Members In Dar Es Salaam, Tanzania: Baseline Results From The Step Project, Joseph K.B. Matovu, Gaspar Mbita, Akeen Hamilton, Frank Mhando, Wynton M. Sims, Noah Thompson, Albert N. Komba, Jackson Lija, Jiajia Zhang Ph.D., Thomas Van Den Akker, Dustin T. Duncan, Augustine T. Choko, Donaldson F. Conserve

Faculty Publications

Background

A variety of strategies have been used to reach men with HIV self-testing services, including social network-based HIV self-test kits distribution. However, few studies have assessed men’s comfort to distribute to or receive HIV self-test kits from close male friends within the same social network. In this study, we assessed men’s comfort to distribute to and/or receive HIV self-test kits from close male friends and associated factors among men who socialize in networks locally referred to as “camps” in Tanzania.

Methods

Data are from the baseline survey of a cluster-randomized controlled trial conducted in June 2019 with 18 social …

In Vivo Antidiabetic Activities Of Polyherbal Extracts Against Streptozotocin-Nicotinamide Induced Type 2 Diabetic Mice Model, Pradnya Jagtap, Yashashri Nimbalkar, Vidya Patil, Ravindra Y. Patil

Tanzania Journal of Science

Diabetes mellitus is a chronic metabolic disorder and rapidly increasing cases of diabetes throughout the world are major concerns in both developed and developing countries. Currently available oral antidiabetic medicines have limitations in efficacy and safety, which in conjunction with the emergence of diabetes mellitus as a global epidemic have aided the popularity of alternative therapies to manage the disease safely and more efficiently. Herbal medicines are accepted as alternative therapies for blood sugar control. Gymnema sylvestre, Boerhavia diffusa, Tinospora cordifolia, and Argyreia nervosa are some potent herbs used for the management of diabetes. Mixing of these plants in different …

An Age-Structured Model For Transmission Dynamics Of Malaria With Infected Immigrants And Asymptomatic Carriers, Asha S Kalula, Eunice Mureithi, Theresia Marijani, Isambi Mbalawata

Tanzania Journal of Science

Abstract An age-structured (children and adults) model for the transmission dynamics of malaria with asymptomatic carriers and infected immigrants has been analyzed. We first analyze a model without infected immigrants. It shows that the disease-free equilibrium exists and is stable when and unstable for . Also, we compute the sensitivity indices of the basic reproduction number. The basic reproduction number is most sensitive to the mosquito biting rate. Besides, the sensitivity of the basic reproduction number shows that the children's class parameters are more sensitive than those of adults. In the presence of infected immigrants, the model does not admit …

Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima

Tanzania Journal of Science

A two-level facility location problem (FLP) has been studied in the transportation network of emergence maize crop in Tanzania. The facility location problem is defined as the optimal location of facilities or resources so as to minimize costs in terms of money, time, distance and risks with the relation to supply and demand points. Distribution network design problems consist of determining the best way to transfer goods from the supply to the demand points by choosing the structure of the network such that the overall cost is minimized. The three layers, namely production centres (PCs), distribution centres (DCs) and customer …

Stocking Density, Growth And Survival Rate Of Post-Settled Juveniles Of Holothuria Scabra (Jaeger 1833) Reared In An Ocean-Based Floating Hapa, Yussuf S Yussuf, Saleh As Yahya

Tanzania Journal of Science

Ocean-based nursery system using floating hapa have proved to be the best option for raising early sandfish juveniles. However, the nursery system can be further improved by providing key information that will support their application. The present study provides information on the effect of stocking density on growth and survival of sandfish juveniles reared in floating hapa (1 x 0.5 x 1 m). Three densities were tested, 100, 200 and 400 early juveniles (5 mm; 0.093 g) per hapa net in a randomized set-up. Initial density of 100 and 200 showed significant higher growth rate and final size (0.082–0.074 g/day; …

Josephson Effect In Mgb2/Pd/Nb Trilayer Josephson Junctions, Anayesu B Malisa

Tanzania Journal of Science

This paper reports fabrication techniques and results of MgB2/Pd/Nb trilayer Josephson junctions. The MgB2 bottom electrode was co-evaporated by molecular beam epitaxy (MBE) technique from both magnesium and boron sources at a low substrate temperature ~ 300 °C, while the interlayer and the top niobium electrode (Pd/Nb bilayer) were deposited ex-situ using RF sputtering. The junctions exhibited  and  Josephson effect as well as a modulation of the critical current in a magnetic field applied in a direction normal to the junction plane. Fractional and integer Shapiro steps were observed at voltages corresponding to the frequency of the applied microwave radiation …

Mollusc Shells From Neolithic Contexts In The Lake Eyasi Basin, Northern Tanzania, Musa S. Mwitondi, Albert S. Mjandwa, Pastory M. Bushozi

Tanzania Journal of Science

The study of the Neolithic period in the Lake Eyasi Basin was dominated by attempts to formulate the area’s chronology, mobility, settlement patterns, subsistence, and cultural capabilities of Neolithic people as attested by domesticated animals, pottery, and lithic artefacts. Occasionally, studies on molluscs were mentioned, but rarely described in detail. Neolithic sites across the Lake Eyasi Basin have yielded remains of both terrestrial (gastropods) and freshwater mollusc shells (mussels). The abundance of mollusc shell remains in the archaeological records of the Lake Eyasi Basin have played a great role in chronological settings, mobility and community integrations, studies of settlement patterns, …

Maintenance Automation Architecture And Electrical Equipment Fault Prediction Method In Tanzania Secondary Distribution Networks, Hadija Mbembati, Kwame Ibwe, Baraka Maiseli

Tanzania Journal of Science

Distribution networks remain the most maintenance-intensive parts of power systems. The implementation of maintenance automation and prediction of equipment fault can enhance system reliability while reducing the overall costs. In Tanzania, however, maintenance automation has not been deployed in secondary distribution networks (SDNs). Instead, traditional methods are used for condition prediction and fault identification of power assets (transformers and power lines). These (manual) methods are costly and time-consuming, and may introduce human-related errors. Motivated by these challenges, this work introduces maintenance automation into the network architecture by implementing effective maintenance and fault identification methods. The proposed method adopts machine learning …

High Speed Hill Climbing Algorithm For Portfolio Optimization, Collether John

Tanzania Journal of Science

Portfolio can be defined as a collection of investments. Portfolio optimization usually is about maximizing expected return and/or minimising risk of a portfolio. The mean-variance model makes simplifying assumptions to solve portfolio optimization problem. Presence of realistic constraints leads to a significant different and complex problem. Also, the optimal solution under realistic constraints cannot always be derived from the solution for the frictionless market. The heuristic algorithms are alternative approaches to solve the extended problem. In this research, a heuristic algorithm is presented and improved for higher efficiency and speed. It is a hill climbing algorithm to tackle the extended …