Theses and Dissertations Collection

Permanent URI for this collectionhttp://10.10.97.169:4000/handle/123456789/3403

Browse

Now showing 1 - 5 of 5

A technical evaluation of ten internet search engines for indexing and retrieving scientific literature
(Sokoine University of Agriculture, 2001) Busagala, l. S. P.
Several public Search Engines exist of which their coverage and response time differ. Now which one does perform best under the present connectivity? This study aimed at investigating the information indexing and retrieval effectiveness and efficiency of ten selected search engines under different connection speeds at two University Libraries namely Sokoine University of Agriculture (SNAL) and University of Dar es salaam Library (UDSM). Google followed by Yahoo outnumbered all the other eight-search engines in terms of relevance, precision, and responsiveness. In terms of other features such as phrase searching, simple and natural language interface, high quality of display results, these search engines were the best. MetaSearch engines especially MetaCrawler performed the worst in indexing and retrieving scientific literature particularly at UDSM library. There was a significant difference of search engines performances between the two connection speeds. User information searching skills was notably poor calling an action from information professionals.
Factors limiting livestock based entrepreneurships in Tanzania: a case of livestock training agency (LITA) graduates
(Sokoine University of Agriculture, 2022) Chassama, Alphonce Lucas
The study was conducted to investigate the factors limiting entrepreneurship among livestock professionals. It draws empirical data and evidences from Livestock Training Agency (LITA) graduates in order to identify factors limiting them in establishing livestock based enterprises. The sample comprised of 122 LITA graduates obtained through snowball sampling technique and six (6) key informants including owners of viable livestock-based enterprises, LITA campuses, Farm Managers, and District Officers in Local Government Authority. Data were collected using a questionnaire and key informant interview checklists. Chi-square test and independent sample (t-test) were used to test the characteristics of respondents in relation to engagement in livestock enterprises. Descriptive analysis was conducted to examine perceptions, to assess attitudes of LITA graduates, and to analyze challenges and constraints encountered in running livestock based enterprises. Multiple logistic regression analysis was carried out to enable inference making on the relationships between entrepreneurship in livestock sector and other factors. The study found that attitudes such as individual fear for failure and unwillingness to take risks limit entrepreneurship in livestock sector to a greater extent, followed by lack of confidence in entrepreneurships and inability to capitalize available business opportunities in livestock sector. It was further discovered that perceptional factors limit entrepreneurship in livestock sector to a moderate extent. Dedicated initiatives are required in counteracting the major impeders in order to promote entrepreneurship in livestock based enterprises. However, providing support such as credit loan will help LITA graduates in starting as well as expanding viable livestock businesses. It is therefore important for the government and other stakeholders to ensure that LITA graduates are provided with adequate support to deal the identified factors that potentially limit entrepreneurship in livestock based enterprises.
Determinants of inbound tourism demand in Tanzania.
(Sokoine University of Agriculture, 2013-05) Kazuzuru, Benedicto
The study investigates the determinants of inbound tourism demand both at macro and micro levels. At macro level the study investigates the determinants of the number of tourist arrivals, while at micro level the study investigates the determinants of the per capita expenditure of tourists, their length of stay and their choice of a package tour. In achieving the first objective, panel data regression analysis was employed using the number of arrivals obtained from the Ministry of Tourism and Natural Resources (1995-2007) as well as a number of covariates from different sources. Regarding the determinants of tourists’ per capita expenditure, an OLS was applied on a cross-section of tourists surveyed in the years 2001, 2007 and 2008. As for the length of stay, a survival analysis was employed, whereas for the choice of a package tour a binary logistic regression was used, in each case using the cross-section data of the years 2001, 2007 and 2008. Among the key findings is that non price factors (such as the country’s economic development) are more influential than price factors in attracting tourists to Tanzania. Trip-related characteristics of the tourists such as purpose of visit and the number in travel party were found to be the most influential variables in explaining tourists’ daily spending, length of stay and choice of package tour. To promote the number of arrivals it is implied that the government should invest more in the non-price factors such as infrastructure whereas to enhance micro demand, promotion organs and other stakeholders should attune their marketing strategies more to trip-related characteristics of the tourists than to other factors.
Modelling the in-human host and in-mosquito dynamics of malaria parasite and effect of therapy
(Nelson Mandela African Institution of Science and Technology, 2017) Selemani, Mohamed Abdallah
In this study, a basic mathematical model for the in-human host and in-mosquito dynamics of malaria parasite is formulated. A positive invariant region of the model was established, and a basic reproduction number 7vo, of the model was computed. Conditions for existence and stability of two equilibrium points: malaria free equilibrium (MFE) and malaria infection equilibrium (MIE) were established. The impacts of model parameters on control of malaria infection were assessed through the sensitivity analysis of TZ q . Despite having lower sensitivity index compared to death rate of merozoites. and death rate of schizonts have greater impact on malaria control than that of merozoites. The model was extended to incorporate the effect of immune responses using nonlinear bounded Michaelis- Menten-Monod functions to describe how immune responses interact with infected cells and parasites. Our results revealed that immunity has significant influence on reducing malaria infection at erythrocytic and sporogonic stages, but not at exo-erythrocytic stage. We further extended the model to incorporate the antimalarial drug therapy, where four thera peutic classes of antimalarial drugs in various stages of entire life cycle of malaria parasite are included. In contrast to the immunity whose effect reduces infections on only two stages, drug therapy has the effect of reducing infection on all stages of the life cycle. Although its compo nents do not appear in the expression of reproduction number, tissue schizonticidal drugs reveal a substantial effect on reducing the infection at each stage of malaria life cycle. This study suggests that a combination therapy with all four classes of antimalaria! drugs should be developed because of its prolific effect on controlling malaria, and for such case, an artemisinin derivatives-primaquine combination therapy is proposed.
Optimization of thermal cooling Parameters applied to rock Storage systems
(2015) Matofali, Alex Xavery
This study presents a mathematical model for thermal energy storage in low energy buildings. The cooling system which uses rock bed for storing night cooling to be used later for daytime air conditioning is presented. The work initially focuses on the mathematical descriptions of the thermal cooling applied to rock storage system. A numerical method of solution is outlined and the results are compared with measured data at the outlet of the bed both using the measured inlet temperature. A good agreement of trend is observed. The results show two effects of the cooling system on the air temperature, which are damping and time delay of the peaking. The differences are examined through sensitivity analyses for both the convective heat transfer coefficient and mass flow rate. A parametric study for heat storage with materials and bed size is given. A genetic algorithm (GA) is used as a tool to identify the thermal cooling system parameters related to the mathematical model, including the radius of the sphere (rocks), mass flow rate, convective heat transfer coefficient and length of the rock bed. The simulation results have shown an improvement on the performance of the model with identified parameters compared to the performance before parameter optimization. In general, the model with optimal parameters has shown robustness to predict the performance of the cooling system by reducing the input (air) temperature as much as possible at the time when the temperature is hottest.

Browse

Recent Submissions