Department of Mechanical and Industrial Engineering

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Browsing Department of Mechanical and Industrial Engineering by Title

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    5.0 Building Innovation Networks in Dried Cassava Value Chain: Qualitative Evidence from Innovation Brokerage
    (2015) Mgumia, Athman H.; Mattee, Amon Z.; Kundi, Beatus A. T.
    Agricultural development in developing countries is challenged by weak innovation systems and lack of innovation capacities among key actors. Integration of agricultural innovation perspectives and value chain approach for development have made the interaction between a wide range of actors of innovation to become more complex demanding different sets of knowledge, environment and incentives. The traditional homogeneous intermediary layer of agricultural extension appeared to be ineffective to this situation. As a result the majority of smallholder farmers are facing exclusion from participating in supplying the long value chains. In countries characterized by mature innovation systems, a specialized innovation-brokering role emerged as an alternative to deal with innovation challenges in agricultural sectors (market and system failures). This study, using a case study approach, intended to offer empirical evidence of the roles of innovation brokerage implemented on cassava value chain by NGOs in the setting of developed countries and where the innovation brokerage is not recognized by the agricultural knowledge infrastructure (R&D institutions and extension services). Important outcome of this analysis was that innovation brokerage roles were crucial in agricultural innovation as it is beyond the capacity of R&D extension service. Hence, the Ministry of Agriculture Food Security and Cooperative and other relevant stakeholders should recognize the innovation brokerage roles and establish an institutional framework for its functioning within the agricultural knowledge infrastructure.
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    Adhesion and Scratch Testing of Antibiotic Loaded Poly-Lactic Acid Biocomposite Thin Films on Metallic Implants
    (Trans Tech Publications, 2018-10) Karacan, Ipek; Chou, Joshua; Ben-Nissan, Besim; Macha, Innocent J; Juritza, Arion; Wang, Andy H; Muller, Wolfgang H; Grossin, David; Taraschi, Valerio; Oktar, Faik N; Swain, Michael
    Surface modifications have been progressively applied in order to improve the mechanical, biological and chemical properties of metallic dental and orthopedic implants. Therefore, the novel and multifunctional biocomposites coating matrices, which also consist of local and targeted drug delivery systems, are the most recent applications in the medical field. In this study, gentamicin antibiotic containing HAp bioceramics were utilized in a biodegradable poly-lactic acid thin film matrix which was applied to Ti6Al4V metallic implant surfaces. Nanoindentation and scratch test methods were applied. It was observed that, bonding between coating and the substrate is strong enough to be used in implant applications. Additionally, it was observed that the hardness and Young's Modulus values of uncoated Ti6Al4V disc were 4.3 and 125.2 GPa, respectively. However, under the same testing conditions, it was also observed that the H values (0.6-0.8GPa) and the E (50-60 GPa) values of PLA-HAp biocomposite coated samples are slightly higher than the H values (0.4-0.6 GPa) and the E values (40-50GPa) of only PLA coated sample.
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    Advances in Bioglass and Glass Ceramics for Biomedical Applications
    (Wiley, 2016-05) Ben-Nissan, Besim; Choi, Andy H.; Macha, Innocent J
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    Advances in Calcium Phosphate Nanocoatings and Nanocomposites
    (Springer, 2013-12) Choi, Andy H.; Ben-Nissan, Besim; Conway, Richard C.; Macha, Innocent J
    It is possible by using nanocomposite approach to control the strength and Young’s modulus of the composite to become close to those of human cortical or cancellous bone. This is made possible with the help of secondary substitution phases. Various materials have been applied as biomaterials and tissue regeneration materials, and the in vivo cytotoxicity and biocompatibility have been the main consideration in their use and their long-term success. This chapter aims to give a brief introduction and current applications of calcium phosphate nanocomposites as tissue engineering and as a delivery vehicle for drugs, genes, and proteins. Furthermore, the chapter will also examine the potential use of calcium phosphate nanocomposite coatings for tissue engineering scaffolds.
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    Advances in the HTAG Technology and Process of Biomass
    (Academic Journals, 2008) John, Geoffrey R.; Wilson, Lugano; Mhilu, Cuthbert F.
    High Temperature Air/Steam Gasification (HTAG) is a process in which a highly preheated air/steam is utilized as the oxidizer. The HTAG process follows the developments in the High Temperature Air Combustion (HiTAC), which has shown to be superior in energy saving and pollution reduction compared to the conventional combustion technology. The preheated oxidizer provides additional energy into the gasification process that enhances thermal decomposition of the gasified solid feedstock. Consequently, the HTAG increases both the calorific value of the producer gas, and the cold gasification efficiency. In this work, the advantages of the HTAG processes is presented by considering performance influencing parameters that include materials quality, oxidizer type, equivalence ratio (ER), gasification temperature, and bed additives.
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    An Alternative Synthesis Method for Di Calcium Phosphate (Monetite) Powders from Mediterranean Mussel (Mytilus galloprovincialis) Shells
    (Springer NATURE, 2013-08) Macha, Innocent J; Ozyegin, Lutfiye S; Chou, Joshua; Samur, Ramazan; Oktar, Faik N; Ben-Nissan, Besim
    Marine species, such as corals, sea shells and nacres, attract special interest in bioceramics field for bone graft, bone cements and drug delivery applications. Most of the marine structures are made up of pure calcium carbonate (calcite or aragonite) with a very small amount of an organic matrix. In the past the most common way to transform these structures to hydroxyapatite was hydrothermal transformation method. This current work introduces a new approach for producing fine powders of calcium phosphates from Mediterranean mussel (Mytilus galloprovincialis) shells. A comparative study was carried out to investigate the differences of these powders under only hot plate heating and hot plate heating together with ultrasonic agitation while H3PO4 was added. The temperature of the hotplate was kept constant at 80 oC and then, H3PO4 was added drop wise into the solution for 2 hrs. The mixture was then placed into an oven at 100 oC for 24 hrs. They were further calcined at 800 oC for 3 hrs. XRD, FTIR and ICP-MS were used to identify the structure and composition. It was found that the final powders were predominantly monetite, with some tricalcium phosphate as a secondary phase. This relatively simple and efficient method can be easily applied to produce calcium phosphate precursor powders for a range of biomedical applications.
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    Analysis of Manufacturing Capability Variables for Small Metalworking Industries
    (The Tanzania Engineer, IET Journal, 2010) Mgwatu, Mussa I.
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    Analysis of Nox Reduction in Diesel Engines By Air Injection Using Stochastic Modelling
    (2009-07) Mkilaha, Iddi; John, G. R.
    Combustion phenomena have been found to be dependent on the turbulence of the air/gas and fuel in the cylinder. By enhancing turbulent mixing of fuel in the combustion chamber it is possible to improve combustion process. Based on the stochastic nature of turbulence of combustion processes as occurring in an IDI internal combustion engine, a model was developed based on these principles when compressed air was injected into the engine. The air injection was carried out in order to control the emission of NO x and soot simultaneously. In the present model, the mechanism of NO x formation is modeled using the thermal NO x principles while the soot emission is modeled using the global combustion model, which considered combustion as heat addition. Obtained results show close agreement with the experimental ones. The Zeldovich model used has been found model closely IDI engine processes also for the case of air injection as is case of a normal engine. This is due to the microscopic treatment of the mixing process, which involved over-simplification of HC combustion chemistry. It is shown that although there is no substantial temperature drop when compressed air was injected into the chamber, at microscopic scales, the mixing process that occur lead to local temperature drop. It is these local areas of temperature quenching that enhance the suppression of the formation of NO x . At high loads, however, particulate and HC are increased due to the enrichment of fuel in the local areas where the temperatures have substantially been reduced
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    Analysis of Power Efficiency of a Direct Driven Locally Fabricated Permanent Magnet AC Generator for Small-Scale Wind Power Applications in Tanzania
    (Tanzania Journal of Engineering and Technology, 2013) Msuya, R. A.; Kainkwa, R. R. M.; Mgwatu, Mussa I.
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    Analysis of Tanzanian Energy Demand Using Artificial Neural Network and Multiple Linear Regression
    (2014-12) Kichonge, Baraka; Tesha, Thomas; Mkilaha, Iddi; John, Geoffrey
    Analysis of energy demand is of a vital concern to energy systems analysts and planners in any nation. This paper present artificial neural network-multilayer perceptron (ANNMLP) and multiple linear regression (MLR) techniques for the analysis of energy demand in Tanzania. The techniques were employed to analyze the influence of economic, energy and environment indicators models in predicting the energy demand in Tanzania. Statistical performance indices were used to evaluate the prediction ability of economic, energy and environment indicators models using ANN-MLP and MLR techniques. Predicted responses values of ANN-MLP and MLR techniques were then compared to determine their closeness with actual data values for determining the best performing technique. The results from ANN-MLP and MLR techniques showed the best model for predicting the energy demand in Tanzania were from energy indicators as opposed to economic and environmental indicators. The ANN-MLP prediction values had a correlation coefficient (CC) of 0.9995 and mean absolute percentage error (MAPE) of 0.67% outperforming the MLR technique whose CC and MAPE values were 0.9993 and 0.83% respectively. ANN-MLP technique graphical presentation of actual against predicted values showed close relationship between actual and predicted values as opposed to the MLR technique whose predicted values deviated much from actual values. Analysis of results from both techniques conclude that ANN-MLP outperform MLR technique in predicting energy demand in Tanzania.
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    An analytical study on establishing strategies for improving the productivity of the spinning industries
    (Inderscience, 2022-02-09) Kundi, Beatus A.T.; Taifa, Ismail WR; Mwasubila, Ibrahim Joseph
    Strategies for improving the productivity of the spinning industries are much needed. In this paper, a case of a spinning industry was systematically studied. The strategies for enhancing productivity were established through a mixed approach. The studied industry experienced low productivity as they were only achieving 55%-68% of their production plan. Also, their actual operational machine availability was 67%. The proposed strategies include improving the spooling and the drawing process by installing new machinery technology; improve raw materials and components flow; hiring well-trained workers; develop employee training programs; search for new market segments; establish effective information and communications technology section, and develop an implementable maintenance plan. The study also revealed that system dynamics modelling helps to arrange descriptive information analytically. Thus, Vensim® software was applied to illustrate the differences between productivity, specifically before and after implementing the established strategies. The study considered only a single industry and 'single-factor productivity measures'.
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    Antibiotic Containing Poly Lactic Acid/Hydroxyapatite Biocomposite Coatings for Dental Implant Applications
    (Trans Tech Publications Inc, 2017-11) Karacan, Ipek; Macha, Innocent J; Choi, Gina; Cazalbou, Sophie; Ben-Nissan, Besim
    The biodegradable and biocompatible antibiotic containing thin film composites are very appropriate biomaterials as coating materials for dental implants because of their adjustable drug loading and release rates for the prevention of implant related infections. Coralline hydroxyapatite (HAp) was loaded with gentamicin antibiotics and combined with a biodegradable polylactic acid (PLA) to form thin film composites. PLA-HAp, PLA-Gentamicin (GM) and PLA-HAp-GM composites were produced, and their dissolution studies were carried out in phosphate buffered saline under SINK conditions. It was observed that the coatings could be efficiently applied to titanium dental implants and the drug release rates can be efficiently controlled.
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    Antimicrobial finishing of textiles by modified clay minerals
    (2014-09) Grethe, Thomas; Bidu, Jerome; Mahltig, Boris; Haase, Hajo
    Antimicrobial finished textiles are suitable for a wide range of applications. For instance, they can be advantageous in sportswear, but are also usable for hygienic and medical products. Especially patients suffering from neurodermatitis or diabetes can gain benefits due to a reduced risk for the appearance of secondary infections. An antimicrobial effect can be realized by metal ions from zinc, copper, and silver. An inorganic storage matrix is applied to load the material with these metal ions. Fixation of storage matrices is done by sol-gel-technology. The resulting porous hybrid film allows the ions to diffuse into the surrounding medium.
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    Application of EasyCFD for Solar Dryer Performance Improvement
    (2012-11) Yustas, Y. M.; Kimambo, C. Z. M.
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    The Application of the Agricultural Innovation System Approach in Technology Development in Tanzania: Researchers' Perceptions and Practices
    (Taylor & Francis, 2015) Mgumia, Athman H.; Mattee, Amon Z.; Kundi, Beatus A. T.
    This paper examines the perceptions of researchers towards features of the innovation system approach. It also examines the extent of incorporation of these features into Tanzania's existing National Agricultural Research System (NARS). Both qualitative and quantitative data were collected from 100 purposefully selected researchers from 13 public and three private research institutes, and one university. Most (81%) of the researchers perceive end-users (farmers) as an important actor. Other actors such as intermediary organisations (extension), regulatory bodies and entrepreneurs are perceived as important by half (50%) of the researchers. On the other hand, most of the researchers perceive the roles of these actors to be similar to the traditional roles of actors under NARS. The indicators used in measuring the success of agricultural innovation were mainly associated with the pattern of adoption and productivity potential of technologies, suggesting that a linear model of innovation is still dominant in NARS. We conclude that the mode of agricultural innovation under NARS in Tanzania is in transition from a linear to a system model of innovation. The study suggested that policies should be redesigned to include wider participation of stakeholders in agricultural innovation; the mandate and capacity of extension services should be expanded to include facilitation of innovation; and indicators of monitoring and evaluation should be all-inclusive to include technical and social changes.
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    Applying Data Envelopment Analysis to Measure the Efficiency of Healthcare Industry in Dar es Salaam Region of Tanzania
    (The Tanzania Engineer, IET Journal, 2012) Mapunda, B.; Mgwatu, Mussa I.
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    The appropriateness of village level sugar processing technology in Tanzania
    (Academy Science Publishers, African Academy of Sciences, 2006-03) Chungu, A. S.; Kimambo, C. Z. M.
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    Assessing the digitalisation level of the Tanzanian apparel industry: Industry 4.0 perspectives
    (Emerald, 2022-05-19) Taifa, Ismail WR; Mollel, Joshua Z; Nhelekwa, Lucas B
    Purpose Industry 4.0 has an inimitable potential to create competitive advantages for the apparel industry by enhancing productivity, production, profitability, efficiency and effectiveness. This study, thus, aims to assess the digitalisation level of the Tanzanian apparel industry through the Industry 4.0 perspectives. Design/methodology/approach A mixed-methods-based approach was deployed. This study deployed semi-structured interviews, document review and observation methods for the qualitative approach. For the quantitative approach, closed-ended questionnaires were used to ascertain the digitalisation levels and maturity level of the textiles and apparel (T&A) factories and small and medium-sized textile enterprises in Tanzania. The sample size was 110, with participants engaged through the purposive sampling technique. Findings Industry 4.0 frameworks evolved into practices mainly since 2011 in several service and manufacturing industries globally. For Tanzania, the findings indicate that the overall maturity level of the T&A industries is 2.5 out of 5.0, demonstrating a medium level of adoption. Thus, the apparel industries are not operating under the industry 4.0 framework; they are operating within the third industrial revolution – Industry 3.0 – framework. For such industries to operate within the fourth industrial revolution – Industry 4.0 – that is only possible if there is significantly well-developed industrial infrastructure, availability of engineering talent, stable commercial partnerships, demand from the marketplace and transactional relationship with customers. Research limitations/implications This study’s limitations include: firstly, Industry 4.0 is an emerging area; this resulted in limited theoretical underpinnings in the Tanzanian perspectives. Secondly, the studied industries may not suffice the need to generalise the findings for the entire country, thus needing another study. Originality/value Although Industry 4.0 conceptual frameworks have been on trial in several industries since 2011, this is amongst the first empirical research on Industry 4.0 in the Tanzanian apparel industry that assesses the digitalisation levels.