Tanzania Journal of Engineering and Technology

Influence of the Substrate Temperature and Ag Incorporation on the Properties of Reactively DC Co-Sputtered Ag:TiO2 Thin Films

2024-10-19T06:45:28+00:00

This study reports on the influence of substrate temperature on the properties of Ag-doped TiO2 thin films. The films were deposited by reactive DC co-sputtering of Ti and Ag targets at different substrate temperatures and Ag target sputtering powers. Grazing incident X-ray diffractometer confirmed that all films were polycrystalline with dominant peak oriented along (101) planes representing the anatase TiO2 phase. The average grain size of the samples improved with increase in deposition temperature. At a substrate temperature of 450, the samples had a dominant peak representing the rutile phase, suggesting partial transformation from anatase to rutile phase. The electrical conductivity of the samples increased with increase in substrate temperature; however, the average solar transmittance was decreased. Ag doping increased the electrical conductivity of the TiO2 samples by one order of magnitude compared to the undoped ones. A good compromise between the electrical conductivity (1.304 (cm)-1) and solar transmittance ( > 62%) was obtained at a substrate temperature of 400 and Ag dopant concentrations of 0.2% and 0.28% as determined by Rutherford Backscattering measurements. These results demonstrate the potential of Ag doping and optimisation of deposition conditions for the realisation of TiO2 based transparent conducting oxide that meets requirements for practical applications in optoelectronic devices.

Application of Artificial Neural Network Models for Predicting Diesel and Petrol Prices in the Geographically Sparsed Regions in Tanzania

2024-11-09T20:22:35+00:00

Fuel consumption in Tanzania, mainly diesel and petrol, accounts for 82 percent of the energy consumption in the country, with significant price volatility affecting market stability, availability of fuel, and investment decisions. This study uses an artificial neural network (ANN) with a backpropagating algorithm to predict fuel prices in four regions of Tanzania. Key input parameters include the currency inflation rate (CIR), the petrol fuel inventory (PFI), the diesel fuel inventory (DFI), and the fuel transport costs (FTC). The study selected the 6-10-10-2 ANN structures for Sumbawanga-Rukwa, Mpanda-Katavi, and Mbeya-Mbeya as well as 6-10-9-2 for the Songea-Ruvuma region. The results show that transit distances between 200 and 400 km have a significant effect on the price of fuel, with petrol ranging from 0.1199 to 0.1349 Tanzania shillings per litre and diesel from 0.1203 to 0.1502 Tanzania shillings per litre. Road conditions also have an impact on fuel costs, with average fuel consumption of 0.9685 l/km on gravel roads versus 0.1325 l/km on paved roads. This finding suggests that poor road conditions contribute to higher fuel consumption and price volatility. Transport distances below 35 km have a minimal impact; however, load, speed, climate, and driving habits all contribute to variations. The results illustrate that the increase in distance influences higher price fluctuation for diesel than petrol. The study confirms that the application of ANN for predicting fuel price trends helps decision makers to make sustainable investments. The study recommends consolidation of transport and use of rail to reduce costs, although the limited rail network limits regional availability.

Design and Performance Analysis of Fiber Bragg Grating Temperature Sensor for Industrial Processes Sensing Applications

2024-09-26T09:29:17+00:00

The Fiber Bragg Grating (FBG) sensor has become a widespread sensing device because of its small size, passive design, immunity to electromagnetic interference, and direct ability to measure physical properties like temperature and strain. Recently, femtosecond infrared laser processing and regeneration techniques have resulted in the development of stable high-temperature gratings, which are a powerful tool in smart factories, an aspect of the fourth Industrial Revolution (4IR), and show promise for application in harsh environments like high pressure, high temperature, or ionizing radiation. The development of stable high-temperature gratings that can withstand harsh environmental factors like high temperatures, pressures, and ionizing radiation exposure is especially important in light of the Fourth Industrial Revolution (4IR), where smart factories require reliable, distributed, and real-time sensing systems. FBG sensors are essential instruments for developing Industrial process applications because of their capacity to function dependably under challenging conditions and their versatility for incorporation into industrial processes. The results of the FBG sensor show a high sensitivity of 0.01429 nm°C-1 , a Figure of Merit (FOM) of 1.632 x 10-12°C-1 , and a Full Width Half Maxima (FWHM) of 8.7525 nm. The sensor's determined Quality factor (Q) was 177.8.

Flood Inundation Mapping for the Tana River Delta in Kenya

2024-07-01T13:54:25+00:00

This study aimed at mapping flood inundation areas in the Tana River Delta. The 30 m DEM and digitized streams and road networks data were collected through remote sensing techniques followed by ground truthing. The data used also included Tana River discharge data at Garsen gauging station. Probability distributions were fitted on the annual maximum discharges. The 4 parameter generalized Gamma probability distribution was the best-fitting distribution according to goodness-of-fit criteria and the Q-Q plots and was used to generate the flood quantiles for different return periods. The generated flood quantiles were; 286 m3 /s, 369 m3 /s, 400 m3 /s, 405 m3 /s, 439 m3 /s, and 449 m3 /s for 2-year, 5-year, 10-year, 20-year 50-year, and 100-year return periods respectively. GIS Flood Tool in ArcGIS used flood quantiles to produce flood extents and inundation depths. The largest part of the Tana River delta was predicted to be flooded with inundation depths of upto 1.8 m causing inundation of settlements and leading to the death of people and livestock, as well as the destruction of properties and infrastructure including roads and buildings, farms, crops, among others. The study established that 31% of the schools located along the Tana River in the Garsen sub-catchment are exposed to inundation depths above 0.5 m. Different flood management options were identified for Tana River Delta and were subjected to Multicriteria Analysis for a decision to be arrived at in choosing the best. Advanced technology in recession agriculture, early warning systems, and forecasting were ranked as the optimal options for managing floods in Tana River Delta. The outcomes of this study contribute to preparedness for floods and guide development decisions within the mapped areas.

Comparative Analysis on Design Error Risks in Design- Bid-Build and Design-Build Construction Approaches

2024-11-12T03:38:15+00:00

This study was conducted to compare design errors risk in Design-Bid- Build (DBB) (traditional) and Design-Build (DB) methods in building projects. Several construction projects under both DB and DBB method were reviewed. On most of construction projects under DB method, it was found that there were over supply of floor area due to different reasons. Also, it was found that, clients’ requirements were changed during project execution, which resulted into change on schedule, contract value and project quality. It was also revealed that in most cases, designs were in accordance with the clients’ requirements as submitted earlier but during construction clients requested to add some items, which resulted in change of both contract sum and period. For projects under DBB method, the results showed that during project enactment, projects experienced design errors in different ways such as change in specifications, slow decision making, unforeseen conditions and change in clients’ requirements as the aspect of design errors. Approvals of changed materials and additional works were delayed in some occasions; thus, leading to contractors to slow down the construction. It was also further found that the variation in final cost, time and project quality of building construction projects due to design error aspect is more likely to occur when using DB as a delivery method than DBB. The study suggests knowledge sharing, visitation to site before designing and proper planning for design error reduction.

A Critical Realist ERP Implementation in Zimbabwean Mining Industry Organisations

2024-11-09T20:21:58+00:00

This research uses a critical realist framework to examine the factors influencing the success of enterprise resource planning (ERP) system implementation in Zimbabwean mining industry organisations. From the perspective of critical realism, the mining industry in Zimbabwe faces a complex interplay of opportunities and obstacles while implementing ERP systems. The deployment of ERP in mining firms is critically examined in this paper, emphasising how these systems might improve operational efficiency while considering Zimbabwe's particular socioeconomic circumstances. By exploring underlying structures, mechanisms, and outcomes, the research aims to identify critical challenges and opportunities and develop practical recommendations for improving ERP adoption and effectiveness. The study employs a critical realist approach to comprehend the interconnectedness and feedback loops among structures, mechanisms, and outcomes. The researcher combined qualitative and quantitative data gathering and analysis approaches using a contemporaneous mixed methods design. The researcher conducted four in-depth interviews with key stakeholders to gather rich, contextualised insights and administered eighty cross- sectional survey questionnaires to a broader sample to collect quantitative data. This study examined the multiple obstacles and success aspects of ERP system installation in Zimbabwean mining organisations. The study discovered that while ERP systems offer significant potential benefits, their successful implementation is contingent on several technological, economic, organisational, and regulatory factors. The findings emphasise the need for strong leadership, effective change management, training and development, proper ERP selection, risk management, business process engineering, data migration, and user contact to facilitate successful ERP adoption in the Zimbabwean mining industry. The findings of this research offer valuable guidance for mining organisations in Zimbabwe seeking to implement ERP systems effectively.