Masters Dissertations

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    Adaptive anisotropic diffusion-driven model for denoising iris images
    (University of Dar es Salaam, 2021-04) Kyando, Daniel Michael
    Biometric recognition is the automatic recognition of individuals based on their physiological or behavioral characteristics. A variety of systems require reliable personal recognition schemes to confirm or determine the identity of an person requesting access or service. IRIS recognition refers to biometric systems used to recognize individuals based on their IRIS patterns. In the absence of robust denoising method, these systems are vulnerable to the inaccurate interpretation of the patterns and granting access or service to illegitimate users. The classical Perona-Malik model has attracted wide attention of scholars for its ability to restore corrupted images while preserving useful details (edges and contours). Despite its notable achievements, this model requires manual tuning of the shape-defining diffusion coefficient to generate optimal results. Consequently, the tuning process, which suffers from inconvenience and time-ineffectiveness limits the model in time sensitive application like interpreting the IRIS patterns. Therefore, this work presents a method to adaptively update the value of the shape-defining diffusion coefficient in relation to the noise statistics in the IRIS image. Through a series of experiments, it was observed that the coefficient strongly correlates with the noise statistics in the IRIS image. Therefore, a relationship to describe the correlation was established and encapsulated into the evolutionary polynomial of order two. The polynomial was fitted from running 39 million iterations to generate two-dimensional space R^(K×σ) that contains K and σ variables. Least Absolute Residuals (LAR) is used to approximate the constants. The constants were α=0.00473,β=2.134,and γ=-0.3696 with 95% confidence boundary. The proposed diffusion function was further tested in removing noise in the IRIS images. It generated visually appealing denoized images with higher information content. It sharpens the edges and distinguishes them clearly from homogeneous image a region which is crucial in identification of texture patterns in IRIS images.
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    Determinants of growth and sustainability of local civil and building contractors in construction industry: the case of Dar es salaam city
    (University of Dar es salaam, 2021-10) Muro,Erick Rangya
    The construction sector has long been one of Tanzania's economic foundations. This study aimed at understanding the determinants that drive the growth and sustainability of local contractors who are the key players in construction industry such that, adjusting measures may be developed to improve their successful involvement in the construction sector. The quantitative research method was applied for this study, and questionnaires were used to conduct surveys among local contractors and government officials in regulatory bodies. Spearman’s correlation test was performed to assess the association of the ranked variables. The results revealed that majority of local contractors are not growing consistently, and also most challenges affecting their growth and sustainability are faced at both company and project levels including unfavourable tax schemes and loan costs, delayed payments and bad debts, lack of network or contacts in the right places and low market share due to introduction of force account procedure. Also, the study discovered that the most effective approaches to growth and sustainability are found at the strategic level, which are networking and maintaining good relationships with clients, acquisition of construction equipment and other bankable assets, maintaining a positive culture in the company, and implementing a formal system for measuring performance. According to the findings of this study, there is a need for local contractors to devote more in the methods outlined at the company level in order to eliminate barriers to growth and sustainability at both levels. The research gives statistical results for local contractors in Tanzania to use in order to improve their growth and sustainability. Keywords: Growth, sustainability, construction industry, local contractors
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    Transforming public bus transport operations into an optimum system: The case of Dar es Salaam City
    (University of Dar es salaam, 2020) Madinda, E.C
    Transforming public bus transport operations into an optimum system: The case of Dar es Salaam City Erick Charles Madinda Master of Science (Engineering) University of Dar es salaam, College of Engineering and Technology, 2020 About 81% of currently licensed and operating commuter buses in Dar es salaam city are informal minibuses popularly known as “daladala” the daladala service provision is dysfunctional, characterized by the poor quality of service and safety. The daladala operation has become unmanageable, largely due to its fragmented nature (individual ownership) and its operation outside proper management structures. The authorities regulating public transport has been taking some short-term measures to reduce the daladala inefficiencies with no substantial success. One of the major long-term approaches in improving the public transport system is through the selection of an optimal operational mode from a range of operational alternatives based on competitive tendering for service provision. A keen appreciation of the requirements and priorities of the stakeholders is essential in developing optimal and context-relevant strategies for service improvement. This thesis has analyzed the bus public transport stakeholders’ service priorities as an important input in transforming the bus industry. The methodology involved the identification of four groups of Dar es Salaam public transport industry stakeholders, namely; bus transport users (passengers), operators (services providers) the community (affected minibus users and non-users) and regulators. Key informants, individual operators, and passengers were interviewed to identify the required priorities/attributes by each stakeholder group. It has been observed that generally, stakeholders in Dar es salaam City consider cost, sustainability, and level of services attributes, in descending order, to be of priority. The public transport reform alternatives that are based on the formal competition to operate the public transport service (for-the-market) showed the highest potential for improving public transport in Dar Es Salaam City.
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    Investigating factors affecting the usage of learning management system among instructors In Tanzania higher learning institutions: a case of university of Dodoma.
    (University of Dar es salaam, 2020) Mtani, H
    Investigating factors affecting the usage of learning management system among instructors In Tanzania higher learning institutions: a case of university of Dodoma. Hamadi Mtani Master of Science (Information System Management) University of Dar es salaam, College of Engineering and Technology, 2020 The use of learning management system (LMS) for Teaching and Learning purpose is now expanding in most of the Higher Learning institutions in developing countries including Tanzania. Many of the research studies have focused on students’ side and few of them done in the developed countries. Instructor’s acceptance of the LMS is one of the key successes of this technology because they are playing a great role on the usage of LMS and hence can promote the students utilization of that technology. The purpose of this research was to determine the reasons which make from use or not use the LMS among the experienced and non-experienced LMS instructors at the University of Dodoma. Technological acceptance models such as TAM, TOE, TAUT, UTAUT2, D&M models as well as related literature were been reviewed, then conceptual model was developed. Data was collected among 173 instructors using purposive sampling, then regression analysis was used in order to determine the factors toward behavioral intention to use LMS among 92 experienced LMS instructors. Finally, 15 instructors were interviewed to expore more about the determined factors. Also, the perception and the reasons regarding to LMS use were explored among 81 non-experienced LMS user. The results vealed that perceived LMS usefulness, instructor’s self-efficacy and intrinsic motivation were the reasons for predicting instructor’s intention to use LMS among experienced LMS users. Then insufficient knowledge on the use of LMS, lack of training lack of motivation, lack of motivation, cost of using the internet poor ICT facilities were found to inhabit non-experienced LMS users from the use of LMS for Teaching. Purpose. Findings of this study will help the HLIs in identifying the key issues to consider when implementing LMS trough understanding of attitude and perceptions of instructors upon the use of that system.
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    Development of parametric project cost and time estimation models for Irrigation Construction projects: a case study of the National Irrigation Commission of Tanzania.
    (University of Dar es salaam, 2019) Chigwiye, G
    Development of parametric project cost and time estimation models for Irrigation Construction projects: a case study of the National Irrigation Commission of Tanzania. Gregory Chigwiye Master of Science (Construction Management) University of Dar es salaam, College of Engineering and Technology, 2019. Cost and time overruns is a common phenomenon in irrigation construction projects in Tanzania especially to projects undertaken through government funding through NIRC as implementing agency on behalf of Government of Tanzania (GoT). This dissertation on “Development of parametric project cost and Time Estimation Models for Irrigation Construction projects: a case study of the National Irrigation commission of Tanzania (NIRC)” aimed at filling the gap where by NIRC and other developing partner in irrigation sector will have a clue to what extent cost and time overruns affect irrigation construction projects. Factors affecting cost and time overruns in irrigation construction projects were identified, ranked and prioritized on how each influences the performance of the projects during construction stage. Thirdly eight respondents who are 95% of the total respondents ranked the identified factors based on the selected projects. Association was checked between factors affecting both cost and time overruns in irrigation construction projects. Results found that, the spearman’s coefficient of correlation rs , was calculated to be 0.96. This concluded that there is high degree of association between factors influencing time and cost overruns. With the use of data from 38 projects implemented by NIRC between 2013 and 2018, cost and time parametric model were established. Cost estimation parametric model (CEPM) was developed from top 20% of the highly ranked factors contributing to cost overrun. The top 20% highly ranked factors contributing to cost overrun were inaccurate quality estimates Iqe, increase in scope of the project Isp, inadequate contractor’s capacity Ice, inadequate planning and scheduling by contractors Ipse, unforeseen ground conditions Uge and c which is the Original cost estimate multiply by 10-6. From these independent variables, the model equation was given by C=-16.21+1.07c +14.24 Iqe -11.75Isp-4.88ICC+083IPSC-1.70Uge in Tanzania. Time estimation parametric Model (TEPM) was developed from top 20% of the highly ramked factors contributing to time overrum. The top 20% ranked factors influencing time overruns were inadequate contractor’s capacity Ice, inadequate planning and scheduling by contractor Ipse, inaccurate quality estimate Iqe, increase in scope of the project Isp, adverse weather condition Awe and the original time estimate, t(in days). From these independent variables, the developed model equation TEPM given by T (in days) = -8788+1.03t+9.17ICC-20.21 Ipsc +26.53 Iqe +16.12Isp +62.33Awe.
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    An exploratory study on socio cultural norms around menstrual hygiene management in Tanzania A case study of Moshi district Kilimanjaro
    (University of Dar es salaam, 2019) Tenende, Nuntwale, Willy
    While menstrual Hygiene management ( MHM) is gaining increasing recognition in the sanitation sector, socio cultural norms, act as barrier towards achieving effective MHM. This study aims at investigating motives behind the practice of existing social = cultural norms around menstrual blood and menstruation. This is done by unlocking perceptions and socio cultural norms around menstrual blood and menstruation by identifying and analyzing their impacts on MHM and their association with hygienic practices during menstruation. The mixed method research involved data collection using questionnaires, interview and focus group discussions and analyzed using qualitative and quantitative methods. It was found that over 50% of families which women and girls belong to perceive menstruation positively as a part of women‘s growing process or maturity. Despite the positive perception, negative norms, taboos and beliefs still prevail, but are hardly straightforwardly mentioned because of the secrecy and privacy around menstruation issues, hence not frequently talked about among women .It was found that more than 40% of women faced health problems because of existing norms in the use of menstrual absorbents which were mostly sanitary pads and pieces of cloth or fabrics .About 52% of women using sanitary pads and 28.5% of women using fabrics experienced itching, while around 21% of women using sanitary pads and 48% of women using pieces of cloth have experienced yeast infection (candida). More than 30% of women face mobility restrictions in going to place and worship, market place and work place. It was also observed that 50% of women and girls felt scarred during the first menstruation (menarche) due to existing taboos and lack of menstrual knowledge. Lastly menstrual norms and taboos were found to associate with women preference for menstrual hygiene products ( 171) and women’s menstrual waste disposal practices
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    Evaluation of application of asset management in railway infrastructure management in Tanzania The case of Tanzania Railway Corporation
    (University of Dar es salaam, 2020) Komba, Reuben
    The performance and sustainability of railway transport is largely dependent on the efficiency and effectiveness of the railway infrastructure asset management. Tanzania’s central railway line has had poor performance in the past four decades as result of infrastructure deterioration among other factors. Asset management (MA) refers to coordinated activities of an organization with aim at realizing optimal value from assets by ensuring a balance between costs, opportunities, risk and expectations of stakeholders. Am has been adopted by numerous railway agencies around the globe and have proven to improve performance of railways. This dissertation evaluates the application of asset management in railway infrastructure management at Tanzania railway corporation (TRC). Through literature study, best practices in asset management were identified and summarized. By the use of existing asset management maturity models an assessment of the application of asset management was conducted. The maturity model employed a 5 levels maturity scale (aware, basic, core, intermediate and advanced) which was gauged against sixteen (16) asset management knowledge areas elaborated in the international infrastructure management manual (IIMM) of 2015. A structured questionnaire was also used to assess the awareness on infrastructure asset management at TRC. The findings of the study indicated that the asset management maturity at TRC is still at the awareness level implying there is very low application of asset management at the organization. Further, results indicated low awareness on asset management by personnel working at TRC. Keywords: Asset management, maturity model, maintenance, railway infrastructure.
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    Assessment of causes of construction project Delays in Uganda
    (University of Dar es salaam, 2019) Isaac, Nabaasa
    Construction industry in Uganda is facing a lot of causes of construction project delays. Therefore, the aim of this study was to assess the causes of construction project delays in Uganda at the district level in greater Bushenyi region focusing on transport infrastructure as well as, public and private buildings. One hundred and seventeen different project aspects delay aspect were sourced from literature review. Questionnaires were distributed to stakeholder such as project the manager, district engineers, clients, company owners, architects. Consultants, head teachers, contractors and subcontractors. Outcomes were assessed using mean item score (MIS) with the help of statistical package for social sciences (SPSS).The most causes of construction project delays from the highest ranking were found to be; difficulties in financing project by the contractor, escalating material prices, delay in non-payment of compensation as well as, delay in improving drawings and sample materials. This study concluded that both the government and private sector need to work together to solve these causes because they are very complex and can result into low interest by both par ties solving them together. It is recommended that the government and other player in the private sector should ensure provision of contractors with enough capital to handle contracts so as to avoid delays resulting from limited finance.
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    Improvement of operation of small urban water supply system
    (University of Dar es salaam, 2019) Mwampunga, Moses charles
    Water supply is important to the community because it provide convenient and sufficient access to safe and portable water in a given design area for a given design period of time. Also supplying of water supposed to fulfil the requirement of having minimum cost of construction, operation and maintenance of the project. Water is important in the life of living things like human, animals and plants, if no water no life of those living things therefore water seems to be important for fulfilling the basic necessities of life. In bariadi Town, people often face he problem of water shortage because of lack of reliable sources of water. The best immediately solution required for solving the problem of bariadi is to take water from drilled boreholes where there is a reliable source and sufficient quantity of water. As well bariadi Town council drilled shallow wells and deep wells which planned to improve the availability of water to that area. This dissertation is based on establishment of whether the asset management practice is the cause of the shortage of water. The case study approach was used to collect data through interviews with Water Agencies responsible for management of water projects in Simiyu region and community owned water supply organization it is concluded that asset management performance in Community Owned Water Supply organization and Water. Agencies studied fall short of even the basic practices of assets management. The main reason being lack of knowledge to the Community Owned Water Supply Organization (COWSOs) and shortage number of skilled personnel in the Authority dealing with management of water supply projects. Also it was found that lack of adequate water sources and properly designed and maintained infrastructure which can feed water to the community exacerbate the problem. Therefore the study recommended that the Local Authority should be responsible for managing those projects constructed at the rural areas while in town water Authority should take responsibility. Both the water Local Authority and water agency should acquire necessary knowledge and skills for the purpose of implement appropriate asset management starting with basic assets management and continuously upgrading towards the advanced asset management practices
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    Investigation of the impact of water abstraction for maize crop irrigation on quantity of water in Mkindu River
    (University of Dar es salaam, 2019) Tanika, Emmanuel Julius
    Owing to agriculture activities along the rivers by irrigation from the rivers, Most of the rivers become dry before completion of the cultivation period due to water required for irrigation to be much more than the river flows. The study area was Mkindu Found at Mvomero district which experiences water scarcity during cultivation period. In order to deal with this scarcity, this research aimed at investigating the impact of water abstraction for irrigation of maize at Mkindu and suggesting other sources of water for supplying water during cultivation period. To achieve this goal of investigation of the impact of water abstraction for maize crop irrigation, CROPWAT Model and HBV rainfall runoff Model were employed CROPWAT Model was used for determination of irrigation water required for maize at Mkindu in which 1.913m3/s were obtained as maximum irrigation water required. HBV rainfall runoff model was used for generating flows by using 56 years record length rainfall data. Times series of monthly flows were established from generated daily flows and environmental flows (EFs) regime (monthly EFs) were subtracted. The obtained flows after subtraction of environmental flows were used for determination of impacts of irrigation water abstractions on Mkindu river flows. The results obtained showed at mid stage of cultivation period, maximum river flow is 0.911m3/s while irrigation water required is 1,913m/3s. this result showing negative difference which means maize irrigation is not satisfied and the river will dry. Therefore a reservoir of 953,751.46m3 was recommended to be constructed so as to store water during high flow season and to supply at mid stage of maize cultivation.
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    Adaptive controller design and sizing of battery energy storage system for enhancement of stability of an Islanded Solar photovoltaic systems
    (University of Dar es salaam, 2020) Kisinga, Daniel Angelo
    In this era where the world is faced with many challenges related to clean energy, Solar Photovoltaics SPV) system provide alternative source of energy which is cheaper and readily available. However, the intermittency nature of the solar power affects the voltage and frequency stability of the SPV system. To account for the effect, Energy Storage System (ESS) can be used under suitable control mechanism to stabilize the SPV system. Among different types of ESS, Battery Energy Storage System (Bess) offers a rapid response and therefore, suitable for voltage and frequency stability studies in this dissertation, an islanded SPV system was investigated, the BESS was sized based on compensation of the Direct Current (DC) link voltage and a Sinusoidal Pulse Width Modulation (SPWM) adaptive controller was designed under Voltage Frequency (VF) control strategy. Hill Climbing Maximum Power Point Tracking (HC-MPPPT) algorithm with boost converter was used to track the Maximum Power Point (MPP) of the SPV system. The H-bridge Single phase inventor was used for DC-AC conversion, while a Buck-Boost converter was implemented for charging and discharging the BESS. The system was modeled in MATLAB/ Simulink environment and voltage and frequency stability studies were performed. Under VF control strategy with the SPWM adaptive controller, the abrupt changes in solar insolation and variations of the load. The SPWM adaptive controller showed fast response with capability to maintain the voltage and frequency with the standard desired values compared to the conventional Pulse Width Modulation (PWM) controller.
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    Estimating soil loss rate and sediment yield of the proposed Ngoloweni earth dam, Kingdom of Eswatini
    (University of Dar es Salaam, 2019) Hlanze, Dumsani
    Soil loss and sediments yield affect most of our reservoirs globally. Sediments deposited in water bodies, especially reservoirs can reduce reservoirs can reduce reservoir useful life through loss of storage. Research has found that large reservoirs can lose between 0.5%-1% of their annual storage. While smaller reservoirs on average lose 2.6% as a result of sedimentation. The main objective of the study was to estimate soil loss and sediment yield of the proposed earth dam in Mntjuzalala catchment, Eswatini. This would assist in development soil loss and sediment yield management measures in the catchment. The study employed the Reversed Universal Soil Loss Equation (RUSLE) runoff plots and satellite images for the analysis. Using ArcGIS, land-use/land-cover (LULC) results indicated that there was a significant change between 1988-2018. Grassland cover was observed to have decreased from 39.8% to 18.5% while bushland increased from 13.3% to 37.1%. However, the bushland is not valuable since it is classified as invasive alien plants. Cultivation also experienced increase in recent years, from 3.2% to 21%. This was due to increase in settlements from 11.5% to 19.7% which resulted into increased human activities thus reducing wetland from 32% to 4.5% in between the study period. From estimated soil loss, it was observed that annual average sediment yield was 82.04 tonnes/year and sediment delivery ratio (SDR) was 0.46, thus sediment deposit on reservoir site was 30.19 tonnes/year. The sedimentation rate/annual storage loss was estimated at 1.55% per annum, which would lead to 50% of the reservoir storage having been lost after 32 years when the annual sediment deposition is 1946.75m3. In terms of sediments sources, it was observed that this earth dam site is adjacent to gullies and cattle tracks which are active sources of sediments during rainy season.From the soil erosion and sedimentation outcomes, there is need to implement sustainable land and water management measures in the catchment. This should include activities on soil conservation and sediment retention structures; development and implementation of chiefdom development plan as well as improved institutional arrangements.
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    A framework for assessment of quality management system of aircraft maintenance organizations in Tanzania
    (University of Dar es Salaam, 2020) Sanga, Furaha
    A framework for assessment of quality management system of aircraft maintenance organizations in Tanzania Furaha Sanga Master of Engineering Management (MEM) University of Dar es Salaam, COET, 2020 Quality of maintenance is one among the top three causes of aviation accidents. From 2014 to 2018, in Tanzania accident related to aircraft maintenance has increase by 48.99% per annum. This study assessed and establishes a framework for QMS implementation by Approved Maintenance Organizations (AMOs) in Tanzania. This study used surveys, focus group discussion (FGD) and interviews. Key informants were; managers, auditors, academicians, accident investigators and inspectors. Data were analysed using SPSS and SmartPLS. It assessed 8 QMS principles, 20 QMS elements, 13 barriers and 16 key performance indicators (KPIs). For QMS principles, ‘Process approach’ mean of 3.9 and ‘involvement of people' mean of 3.61 were the highest and lowest respectively. For QMS elements, ‘Inspection and testing’ mean of 4.22 and ‘management responsibility’ mean of 3.78 were the highest and lowest respectively. These values were below the mean of 4.51-5.00 which implies ‘fully implemented’. This implies that QMS is not fully implemented. ‘Lack of top management commitment’ mean of 2.73 and Tack of fund’ mean of 3.21 were the highest and lowest barrier respectively to affect QMS. Since mean of 1.00-3.50 indicates barrier affect QMS, all barriers were found affecting QMS. ‘Fleet average time left to maintenance’ and ‘time taken to accomplish maintenance’ were the only KPIs found within recommended targets. The established framework can be employed by AMO management for effective QMS implementation. This study enriched knowledge in the areas of QMS implementation which is still low in Tanzania. This study is applicable only to AMOs hence future study must cover other aviation entities.
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    Success and constraints of fees-free education policy in enhancing access to quality primary education in Ilala and moshi rural districts
    (University of Dar es Salaam, 2020) Kiriwe, Fatmah Abdul
    Success and constraints of fees-free education policy in enhancing access to quality primary education in Ilala and moshi rural districts Fatmah Abdul Kiriwe MEMA University of Dar es Salaam, COET,2020 This study examined the success and constraints of the recently introduced Fees-Free Primary Education (FFPE) policy in enhancing access to quality primary education in Tanzania. The study was conducted in Ilala and Moshi Rural districts. The purpose of this study was to explore the stakeholders perceptions ot partner involvement areas in implementing the fees-free education policy, establish the preparedness of the government and schools in adopting the policy; assess the impact the policy on enhancing access to quality primary education; and determine the challenges to the effective provision of fee-free education and uncover the strategies to overcome them. The study employed a mixed method research approach. Specifically, it applied a concurrent-triangulation design. Data were collected using questionnaires, interviews, observation, FGDs and documentary review. In all, 120 respondents were involved in the data collection process comprising 2 DEOs, 6 HTs, 64 teachers, 36 pupils and 12 parents selected using purposive and simple random sampling techniques. Quantitative and qualitative data analysis was done using SPSS version 20 and content analysis, respectively. The study was guided by an adapted open systems model (Hoy &Miskel, 2008). The model assisted in examining the flow of resources from the government to facilitate the process of enhancing access to quality primary education. The study found that apart from increasing to access primary education, fee-free education also had impacted on the quality education provided by improving teaching staff remuneration and in-service training. On the other hand, the implementation faced many challenges such as the shortage of teachers, poor learning environment and shortage of teaching and learning materials including books, which are essential in providing quality education. The findings imph that the policy has faced problems in its supply-driven policies, unclear mechanisms, and declining quality of education. Moreover, the fees abolition policy has resulted in low levels of material provision and overall low levels of pupil achievement. Thus, the study recommends for the government to employ non- teaching staff, pass laws that govern operations, include stakeholders in policy lormulanon and facilitation of the schools’ establishment of income generating projects through production units. Also, a similar study should be carried out with a wider scope and geographical reach.
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    Commodity price volatility, tax revenue, and welfare: evidence from Tanzania
    (University of Dar es Salaam, 2020) Joachim, Godfrey
    Commodity prices remain inherently volatile in the global market, exerting pressure on tax revenue with the resulting change in prices and trade (export or import) volumes, as well as the adverse impact on production, consumption, resource allocation and household welfare. This study analyses the effects of commodity price changes and volatility on tax revenue and welfare using Tanzania as a case study. To accomplish this investigation, the study undertakes three tasks. First, it examined the association between commodity price change/volatility and tax revenue using time series data on Tanzania from 1980 to 2017. Second, using QUAIDS model in the compensation variation (CV) framework that accounts for static and dynamic effects, the study investigates the effects of agricultural commodity price changes on household welfare by comparing the period of high and low prices using Tanzania Panel Survey datasets from 2008 to 2015. Finally, using monthly auction coffee prices data from 1998 to 2017, the study examines the welfare consequences of reducing coffee price volatility. Different estimation techniques are employed to estimate effects of commodity price change and volatility on tax revenue and welfare. These include the dynamic Autoregressive Distributed Lag (ARDL), Three Stage Least Square, Compensating Variation (CV) and typical Lucas-like representative agent models. The findings show that, while commodity price change has a positive effect on tax to GDP ratio, commodity price volatility has negative effects. The welfare gain is associated with price increases; while the welfare losses are associated with declines in the prices of agricultural goods. Furthermore, the welfare losses are unevenly distributed depending on the net-market position and strata of the households. Finally, the finding shows that the welfare gains from reducing price volatility for coffee farmers in Tanzania are small. The study findings confirm the argument that, reliance on trade taxes is not favorable for Government's objective to optimize tax revenue because such taxes are adversely affected by commodity price volatility, hence the need to explore other opportunities for increasing tax revenue such as expanding tax bases. Clearly, the finding on welfare impact of reducing price volatility for coffee farmers imply that, measures to support farmers' productivity or value additions, and scaling up agricultural production with commercial focus could be a better strategy for improving the welfare of farmers.
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    The impact of contractor’s assistance fund (CAF) on small and medium local contractor's capacity and capability: a case of Dar es Salaam, Tanzania
    (University of Dar es Salaam, 2019) Simbakalia, Gloria Peter
    This study examined the effect of Contractors Assistance Fund (CAF) on improving capacity and capability of small and medium local contractor in Tanzania. The main objective of the study was to evaluate the impact brought by the establishment of CAP. As for the study area. Dar es Salaam was selected to be the site for data collection. A sample size comprising of 45 SMLC who are CAF beneficiaries and 15 Cl stakeholders were picked to be the main source of primary data. The methods employed during data collection exercise included questionnaire, interview, observation and desk study. In the course of carrying out this study, both qualitative and quantitative data were gathered. The collected data were analyzed using Paired Sample T-test and descriptive statistics (frequency) methods, and the results were discussed to determine specific relationships. The study revealed that out of all registered construction companies, majority (88%) are SMLC. However, much as many construction firms are SMLC, they occupied very few per cent of the market share (25%). Further, the study found that the mean values for all indicators used in determining the magnitude of the effect of CAF was increasing in a range of 1 to 4, except for plants and equipment. This trend implied that CAF has created positive impact to SMLC in the construction industry. Furthermore, it was revealed that more than 30% of CAF beneficiaries upgraded their registration classes through acquiring bid bonds and advance payment guarantees that has helped them to undertake more projects. It is therefore recommended that the existing and emerging challenges regarding CAF operation be solved for sustainability and smooth running of the fund.
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    Assessment of the current state of bridge management system in Tanzania: a case study of Tanzania National Road Agency (TANROADS)
    (University of Dar es Salaam, 2019) Sanga, Fredy
    The main objective of this study was to assess the current state of Bridge Management Systems in Tanzania with TANROADS as a case study. The study has been conducted by investigating the history of bridge management in TANROADS together with assessing how it is conducted. In this study consideration and perception of TANROADS staff on different variables characterizing proper bridge management have been investigated. The study has used qualitative and quantitative approaches of which a sample space containing 10 regions was selected to represent the total of 26 regions. Data were collected by use of questionnaires and interviews. After evaluation of different responses, it was found that the current state of bridge management in Tanzania does not promise good future conditions of bridges. The manual or traditional approach was found to be ineffective as compared to the software approach. Evaluation of respondent's responses found the manual approach to be simple to apply and saves time; however the approach was reactive only to current inspection results. "Such consideration was found not to be suitable over a large network of bridges". The TANBRIDGEMAN software on the other hand found to be better off by having the ability to incorporate different parameters during optimization of maintenance needs such as historic record of the bridge including age, accident, inspection and maintenance record. However, it was found that there were complications in the use of the software. The software was not giving indications in regards to the remaining serviceability life of bridges and expected effect on conditions of bridges as a result of budget cut in the given financial year. In view of obtained survey results and review on challenges and achievements met by various agencies on their way for searching of a better bridge management system, the current state of bridge management in Tanzania requires technically and financially improvements. For example increasing bridge maintenance budget, training of experts and transformation from manual or traditional bridge management system to an improve software.
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    A comparative analysis of the performance behavior of nano and conventional solar PV modules under tropical weather conditions
    (University of Dar es Salaam, 2020) Nkubile, Daudi
    A comparative analysis of the performance behavior of nano and conventional solar PV modules under tropical weather conditions Daudi Nkubile Msc (renewable energy) University of Dar es salaam, COET,2020 In this study, evolution of developments of nano solar PV modules was reviewed, whereby factors such as market share, efficiency improvement and limiting challenges were assessed. Also performance of nano solar PV modules was compared with those of conventional silicon solar PV modules in order to assess the technical competitiveness of nano cells. Major types of nano solar PV modules currently in use and their corresponding market shares are copper indium gallium sellenide (CIGS), cadmium telluride (CdTe) and amorphous silicon with 2%, 3% and 0.5% respectively. Despite the small market share, nano solar PV modules have several advantages over the conventional solar PV modules, such as lightweight, lower production costs and flexibility of their modules. Currently, costs of electricity using nano and conventional solar PV modules stands at USD0.3/W and USD 1.2/W respectively. This makes nano solar PV modules to possess a big potential to be used as the source of solar PV energy. Experiments on performances of nano and conventional solar PV modules involved measuring I-V curves under tropical condition in Dar es Salaam at the offices of the Tanzania Bureau of Standards (TBS).Two pieces of solar PV modules, one being nano solar PV module and another being conventional solar PV module with the same rated peak power of 5W, recorded maximum power of 3.6W and 3.7W respectively at STC irradiance of 1000W/m2.Likewise, at STC, recorded efficiencies of nano and conventional solar PV modules were 10.93% and 12.21%, which is slightly lower than rated STC values which are 14% and 16% respectively. This deviation in the recorded power output at STC irradiance was caused by associated high module temperature of about 59.1°C. Furthermore, from the experiment it was observed that at corresponding temperatures and irradiances below 45°C and 400W/m2, the performance of nano solar PV module was about 5% better than that of conventional solar PV module.
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    Application of natural adsorbents for removal of fluoride in water: a case of Gypsum and Bauxite
    (University of Dar es Salaam, 2019) Rugayi, Bernard
    The research was carried out to apply the natural adsorbent materials of bauxite and gypsum for DE fluoridation of portable water to meet the World Health Organization recommendation of fluoride contraption in water. The X-Ray diffraction and X-Ray Fluorescence tests were conducted to determine the structural components and chemical compositions of the adsorbents respectively. The X-Ray diffraction test indicated that the materials used in this research were bauxite with Al(OH)3 and gypsum with CaSO42H2O as major, components. The X-Ray Fluorescence showed that bauxite contained mainly Al2O3 (57.41%) while gypsum contained mainly SO3 (34.33%) and CaO (29.36%). The adsorbent materials were calcined at different temperatures of 200OC, 300OC and 400oC and the results showed that, the adsorbent materials calcined at 300oC performed best compared to those calcined at 200oC and 400oC for both bauxite and gypsum. The Langmuir and Freundlich model can be used to describe the sorption of both bauxite and gypsum indicating that the adsorbate forms a monomolecular layer on the surface of the adsorbent. The data for sorption kinetics fitted in pseudo-second order kinetics. The initial fluoride concentration in water was 15.21mg/L, with a dose of 30g/L and the final concentration was 0.36mg/L for calcined bauxite at 300oC while with the same initial fluoride concentration and dose for gypsum the final fluoride concentration was 6.05mg/L. with an adjusted Ph value of water to 4 with the same intial fluoride concentration and dose for both bauxite anf gypsum, the final fluoride concentration was 0.11mg/L and 3.9mg/L respectively.
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    The assessment of non-traffic benefits in road transportation economic analysis: “a case study for Upgrading of Makongolosi- Rungwa- Itigi- Mkiwa Road to Bitumen Standard.”
    (University of Dar es Salaam, 2020) Kisaro, Aniceth Joseph
    Economic evaluation of road improvement project requires estimated economic benefits to exceed its economic cost for its implementation to be justified. However, the analysis of these road projects mainly depends on the benefits that are directly related to traffic. Non-traffic benefits that arise to the communities along the road project influence zone are excluded/ ignored in the analysis, since these benefits constitute a very small proportion of overall project benefits and make no impact to its economic evaluation. The study assessed the impact of non-traffic benefits in the economic viability analyses of road improvement projects and revealed that, the selected non-traffic benefits which included; “increased income due to employment during construction, improved access to social services (education and health facility), increased income as a result of economic growth, RoW – road reserve facilitates installation of other public utilities, and land value appreciation,” greatly enhanced the economic performance indicators and constitutes a considerable proportion of benefits to the overall benefits. Additionally, the study also revealed that non-traffic benefits have more impact in low volume roads which constitute of low vehicular-traffic with low traffic growth. Hence, it justifies how significantly is to assess the non-traffic benefits in the economic viability analyses of road improvement projects.