Tanzania Journal of Engineering and Technology

Evaluation of Environmental Management System for Small and Medium Enterprises in Dar Es Salaam, Tanzania

Joseph Malick — 2024-02-23

A system that manages environmental issues of Small and Medium Enterprises (SMEs) from the time of acquisition of raw materials up to disposal of the product is not well clear, especially in Tanzania. Most of the studies have been conducted in the field of environment management but few of them address the evaluation of the management of SMEs activities with respect to the environment. Although the nature of activities of SMEs has little noticeable environmental implications at the individual level but the impact is large due to diversification and labour intensity of these SMEs. SMEs employ about 20% of the total labour force in Tanzania. Thus, the consequences on the environment are therefore very high. In this study both quantitative and qualitative research methods have been used to evaluate the awareness on Environmental Management Systems (EMS), the extent of implementation of EMS, tools used in EMS and Factors that hinder effective EMS. Descriptive and Factor analysis have been used as techniques for analyzing data. The study found a low level of awareness, whereby about 59% of respondents were slightly aware, on EMS, tools used for EMS were found to be more reactive tools than proactive tools. Whereas about 60% of SMEs are inappropriately and inadequately implementing elements of EMS according to ISO 14001. The study found critical factors with high influence on hindering the implementation of EMS including inadequate environmental consciousness of top leaders. It is recommended that more efforts should be invested in creating awareness, impacting the knowledge and skills of implementing the EMS as per ISO 14001 requirements at all levels of SMEs.

Absorbance Enhancement of a Treated Tanzanian kaolin for Removal of Synthetic Dyes from Water

Laurance Erasto — 2024-02-23

The absorbance efficiency of local kaolin clay from Tanzania (Pugu kaolin) has been enhanced to improve its utilization in removal of textile dyes from water. The clay was acid-activated using H2SO4, after calcination at 750oC. Characterization by XRF, XRD, ATR-FTIR and Porosimeter showed kaolinite [Al2Si2O5(OH)4], silica (SiO2) and microcline [KAlSi3O8] as the main phases. Upon acid treatment, silica increased from 44.18% to 58.81% due to the appearance of tridymite, and alumina decreased from 26.70% to 12.74% due to disappearance of the kaolinite. Surface area increased from 15.36 to 149.61 m2 /g due to removal of acid-soluble impurities. The chemical composition showed decrease of Fe2O3 and increase of other major oxides. The impact of acid-activation on contact time, temperature, adsorbent dose, initial pH and absorbate concentration was investigated through batch adsorption technique using basic blue 9 (BB9) and direct red 28 (DR28) dyes. The results at optimal conditions of 3 hours contact time, 27oC temperature, 0.9 g adsorbent dose, initial pH of 11 and initial adsorbate concentration of 90 mg/L, showed that acid modification of the clay increased its capacity to adsorb BB9 from 96.82% to 99.91%, and DR28 from 86.33% to 95.04%. These findings established the influence of modifying the raw clay for its dye removal applications.

Comprehensive Survey on Applications of Internet of Things, Machine Learning and Artificial Intelligence in Precision Agriculture

Doreen Thotho — 2024-02-23

A comprehensive, multidisciplinary analysis of the latest developments in digital agriculture is conducted with the use of artificial intelligence (AI), machine learning (ML), and the Internet of Things. By automation and the use of modern, scalable technology solutions that reduce risks, support sustainability, and give farmers predictive advice, traditional agricultural processes are being updated and improved to maximize production. In this paper, the applications of AI, IoT, and ML in agricultural production systems are discussed in detail. The applications that have been explored can be broadly categorized into three areas: soil management, livestock management, and crop management. Weed detection, disease identification, and yield forecasting are some of the applications for crop management. Two applications of livestock management are animal welfare and production. The use of AI, IoT, and ML will make it possible to collect data from agricultural activities for analysis and the extraction of insightful knowledge, facilitating prompt and accurate decision making to increase agricultural productivity. This will result in farming that is more exact and efficient while requiring less labour and producing high-quality produce.

An Overview of Maternity healthcare Monitoring in Developing Nations

Godphrey Kyambille — 2024-02-23

A healthcare monitoring arrangement is essential for frequently monitoring a patient's health status. Specifically, maternal healthcare systems for tracking are utilized to evaluate the clinical status and monitor any abnormal condition changes during all three trimesters. This paper's objective is to conduct an extensive literature review and acknowledge earlier initiatives and studies conducted previously in maternal health care monitoring. This review focuses on accumulating information from earlier work and presents a general overview of previous studies concerning maternal health care monitoring (MHCM). The paper focuses on the maternal healthcare systems in developing countries accessed by pregnant women during the antenatal period. Furthermore, this paper highlights the challenges in the maternal health sector that include inadequate work conditions for health workers, home-based birth practices, long distances to healthcare facilities, and long waiting times in health facilities. The paper indicates the potential opportunities to strengthen maternal healthcare services and allow effective access to maternal healthcare facilities by pregnant women.

Cost Estimation Proxy Models for Economic Evaluations in Petroleum Projects

Fulmence Stanslaus Kaborogo — 2024-02-23

Petroleum economic evaluation involves estimating revenues from forecasted production profiles and field costs including capital expenditures (CAPEX), drilling expenses (DRILLEX), and operating expenses (OPEX). The existing cost-estimating tool requires several inputs making it time-intensive and difficult to use with few data during the early stages of projects. Majority of the previously developed time saving cost estimations proxy models rely on unrealistic assumptions that include uniform operational costs for different fields with a different number of wells, casings, and drilled depths. This work focused at developing proxy models that consider the variability of the development costs with different parameters. The developed models benefited from a three-step approach for CAPEX, DRILLEX, and OPEX estimations based on datasets from three wells from a gas field in southern coastal Tanzania. Firstly, cost sensitivity analysis was performed using QUE$TOR v15.1.0.18, a cost estimating commercial software to determine the most influential field parameters of the field costs. Secondly, the field cost models were generated based on historical cost data from the gas field using multivariable regression analysis with the help of Statistical Package for the Social Sciences software (SPSS) v22.0. Lastly, errors analysis was done for checking the predictive reliability of the models. Based on the analysis, the CAPEX and OPEX were found to be strongly linearly dependent on the size of processing facilities, number of producing wells in the gas field and production capacity, respectively. On the other hand, a nonlinearity relation was revealed on of the DRILLEX which was strongly dependent on drilled well depth and number of installed well casing. Results show that the developed models are useful and their reliability becomes robust when more data is used. A stochastic modeling approach was further recommended for the models to incorporate uncertainties associated with the parameters used to quantify the cost estimates.

STACK for Computational Science, Mathematics and Engineering e-Learners

Idrissa S. Amour — 2024-02-23

E-Learning platforms such as Moodle, Blackboard and Canvas have got reasonable attention in teaching and learning processes. However, when it comes to assessment and interactive learning activities they offer little service to science, engineering, and mathematics e-learners. In this work, we present the application of the System for Teaching and Assessment using Computer Algebra Kernel (STACK) as a plugin in a Learning Management System (LMS) to address the issue. Different features of STACK are demonstrated and discussed. As an LMS plugin, STACK can be used for interactive delivery of content as well as an assessment tool. Here, examples from mathematics, physical sciences and engineering are demonstrated. The use of STACK extends the applicability of LMS for a wider range of subjects to address existing inability to handle higher level mathematical and computational skills. Additionally, the use of STACK in an LMS is useful in handling tutorials for large classes especially when a blended delivery mode is preferred.

A Two-Stage Based Life Cycle and Principal Component Analysis for Decision Support of Potential Municipal Solid Wastes Management Scenarios, Case study Dar es Salaam, Tanzania

Edwin Richard — 2024-02-23

In most of the urban areas of Tanzania, poor and inadequate solid waste management is a growing environmental and public health concern. Despite an array of solid waste management options, choosing an appropriate one remains a challenge. This study applied a novel two-stage-based approach to assess the environmental impacts and sustainability performance of the 27 scenarios for municipal solid wastes (MSW) management of Dar es Salaam City, Tanzania. In the first stage, the study utilized a life cycle analysis (LCA) to quantify the environmental impacts of MSW scenarios. In the second stage, the study used the principal component analysis (PCA) to assess the sustainability performance of the same. The LCA results indicated that no scenario performed better in all environmental impacts. The current SWM option, which involves landfilling most of the wastes at the Pugu landfill, leads to adverse environmental impacts and therefore poses an environmental and public health risks potential. The PCA results indicated that the scenario that involves the composting of organic wastes, recycling of the recyclable materials and landfilling the rest of the waste is the more sustainable option with a score of -1.7105. Based on the sensitivity analysis, the transportation process is responsible for the higher environmental burdens in most scenarios. Thus, promoting resource recovery at the premises of the waste generation would be crucial for minimizing the environmental impacts. This study demonstrated that the decision-makers could potentially use a combined LCA-PCA methodology to select the optimal MSW scenario.

Augmented Finite Control Set MPC Design Technique for Wide Speed Range Control of Permanent Magnet Synchronous Motor Drives

Patrick Pilla — 2024-02-23

The effective motion control task is highly influencing the final drive performance in wide-range motor drives applications such as electric vehicles (EVs), washing machines, compressors, elevators and lathe machines. Recently, permanent magnet synchronous motor (PMSM) drive has been widely employed in these applications to achieve desired performances such as high efficiency, high torque requirements with minimum size “occupancy”. The PMSM drive features combining with these modern drive applications are highly nonlinear and the desired operation requirements demand high-performance control schemes with fast system response and robustness features. Linear control schemes are usually implemented to drive the PMSM that entail trade-offs between drive performance and simplicity in control implementation. Therefore, this paper presents the nonlinear control technique based on augmented finite control set (AFCS) model predictive control (MPC) scheme (AFCS-MPC). The proposed AFCS-MPC scheme enhances the standard MPC design by augmenting the nonlinear characteristics of the PMSM drive to achieve wide speed range drive performance under both steady-state and dynamic operating conditions. Comparative performance studies have been conducted and presented to confirm the efficacy of the proposed scheme.

Reliability Improvement in the Traction System of Tanzania Standard Gauge Railway

YUSUFU KATUGA — 2024-02-23

In recent years, many African governments have been developing Standard Gauge Railway (SGR) to replace the old after becoming absolute, inefficient Meter Gauge System (MGR) to carry more loads at high mileage and speed while combating the oil and environmental crises. With the increase of SGR, the amount of traction systems has grown sharply, the service life of the traction system has increased gradually, and the components of the vehicle traction system have become worn and aged as a result. While Tanzania is transitioning to SGR with its gradually increasing traction systems, reliability improvement becomes a key for the sustainability of its high-speed train services. This paper, therefore, aims to improve the reliability of traction motors used in Tanzania’s SGR. Firstly, the factors affecting the reliability of the traction system of Tanzania’s SGR and their significance are evaluated. Secondly, the computerized maintenance management system (CMMS) is designed to streamline and automate the maintenance management processes of the traction system of Tanzania’s SGR. Finally, a regression model is established to forecast the uptime based on the established factors. The obtained uptime hours were predicted in order to compute the reliability of the traction motor and its criticality in operation. Critical factors for improving reliability have also been highlighted. These findings play vital roles in establishing the fundamentals of factors that affect reliability as well as strategies and countermeasures to extend the operational life of the traction motors cost-effectively.

Assessing the Performance of Jatropha Curcas and Moringa oleifera Conditioners Towards Improving Fecal Sludge Treatment for Agricultural Purpose

Doglas Mmasi Benjamin — 2024-02-23

Moringa oleifera (MO) and Jatropha Curcas (JC) conditioners have been proposed as alternative solutions to replace chemical conditioners for fecal sludge (FS) treatment. However, their effectiveness in treating FS for safe agricultural use has not been thoroughly evaluated. The aim of this study was to assess the suitability of FS treated with Moringa oleifera and Jatropha Curcas conditioners for agricultural use. Physicochemical parameters Indexes, salinity and sodium hazard levels (Wilcox Diagram analysis), and removal efficiency of nutrients and pathogens were evaluated. Qualitative experiments were conducted using dewatering treatment chambers containing untreated control FS samples, FS treated with Moringa oleifera and Jatropha Curcas conditioners at the University of Dar es Salaam Water Laboratory.

The Sustainability of Simplified Sewer systems

Neema Kijazi — 2024-02-23

The universal access to safely managed sanitation remains one of the challenges to achieving the UN SDG target 6.2 in unplanned urban settlements including the Vingunguti area in Dar es Salaam City which is high-density populated. In an attempt to address this challenge, a simplified sewer system was piloted as an option for achieving safely managed sanitation in this particular area. The objective of this study was to assess the sustainability of the piloted simplified sewer system for its potentiality to up-scale and replication in areas with similar sanitation challenges in the country. Methodology involved collection of data on performance of different components of the sanitation service chain in the study area; and determination of sustainability index using a set of indicators. Data collection techniques included literature reviews, household questionnaires, expert surveys, and physical observations. Data analysis utilized the analytical hierarchy process (AHP) to assign weights to sustainability indicators, while the urban sanitation status index (USSI) was used to evaluate the status of the sanitation service chain, and the sanitation sustainability index (SSI) determined the level of sustainability of the sewerage system. Results showed that the emptying and transport component of the sanitation service chain performed better, with a USSI value of 0.905. However, the system performed poorly on the complementary services (stormwater, greywater, and solid waste management), which had a USSI value of 0.552, probably due to fewer investments in these services. On the other hand, the sustainability of the simplified sewer system was found to be high, with an SSI score of 76.5%. Hence, the study concludes that, simplified sewer system is an appropriate option for addressing safely managed sanitation in unplanned urban settlements where connection to conventional sewer systems is challenging. Thus, the system in Vingunguti area can be up-scaled and replicated elsewhere with similar conditions in the country.