Theses & Dissertations

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https://hdl.handle.net/20.500.14170/1590

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Now showing 1 - 5 of 138
  • Publication
    Mechanical property characterisation of napier grass fibre reinforced polyester composites
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Muhammad Haameem Jameel Ahamed
    The mechanical properties of Napier grass fibre-reinforced composites were characterised. Napier grass fibres were extracted through water retting process. The effect of alkali-treatment on the tensile properties and morphology of the fibres was investigated. The fibres were alkali-treated using NaOH solutions of 5, 10, 15 and 20% concentrations which subjected to single fibre testing. The morphology of the fibres was observed using scanning electron microscopy (SEM). The 10% alkali-treated Napier grass fibres yielded the highest strength. To fabricate the composites, Napier grass fibre and polyester resin were used as the reinforcing material and polymer matrix, respectively. The tensile and flexural properties of the composites were studied. In general, up to a certain threshold value, the tensile and flexural strengths of the composites increased as the fibre volume fractions increased, following which, there was a reduction in strength. The maximum tensile and flexural strengths of the composites were obtained at 25% fibre loading. Water absorption test were conducted by immersing samples in distilled water bath at room temperature (25°C) at different time durations. The wet and dry specimens of composites were subjected to tensile, flexural and scanning electron microscopy (SEM) tests according to ASTM standard respectively. The water absorption pattern of Napier grass fibre composites obeys Fickian behavior at room temperature immersions. The percentage of water absorption is higher for untreated fibres samples rather than treated due to removal of both lignin and hemicelluloses on the fibre surfaces. Tensile and flexural properties of Napier grass composites decreased with increase in percentage of water absorption. Effects of elevated temperature were studied temperature set at room temperature, 45°C, 65°C and 75°C. Higher temperature induces physical and chemical changes in the composites the mechanical properties which are also governed by the unsaturated polyester. However, a significant decrease in tensile and flexural properties was observed for the entire composite tested at elevated temperature. Generally, this study is useful to predict the suitability of using the novel Napier grass fibre as reinforcement in polymer resins.
  • Publication
    Application of project management (PM) principle in UniMAP's wind turbine development program (UWTP) (Restricted)
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Qusay Adnan Abdulaziz
    This study comprises two main components, namely the design and development of a wind turbine system to be erected in UniMAP's campus grounds (called UniMAP's Wind Turbine Development Program; UWTP), and the use of project management (PM) principles in the implementation of the project. The design and development of the wind turbine system takes into account the requirements of the university to generate electricity to offset the current high use of this resource. In order for the turbine system to be effective, it has to be built in a hilly area that has enough wind. However, the cost of such a project is very high, and this does not fulfil one of the requirements of the university. Hence, three alternative designs are proposed, each with its own advantages and disadvantages, including in terms of cost. In terms of the use of PM principles, tools such as Work Breakdown Structure (WBS), Plan-Do-Check-Act (PDCA), Program Evaluation Review Technique (PERT), Gantt Chart, Uncertainties and Risk Assessment, Budgeting, Communication Plan, Scheduling, and Network Diagram are used.
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  • Publication
    Mechanical properties characterization of adhesively bonded T-joint at elevated temperature
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Izzawati Basirom
    Both experimental and analytical studies on mechanical behaviour of adhesive T-joint at elevated temperature are presented. Preliminary analyses established the main variables in adhesive bonding and allowed an experimental study to be developed. The analytical study of adhesive T -joint was developed to predict the adhesive bonding strength and to determine failure mechanism on the stress distribution along interfaces of adhesive layer. The purpose of this study was to identify mechanical properties of adhesive that have good temperature resistance while providing high bond strength to the adhesively-bonded T -joint. The effects of the adhesive thickness and environmental on the bonded strength were established from a series of experiments conducted in elevated temperature. Together with the assessment of physical properties of the adhesive structure morphology and with the supporting studies of the microstructure of epoxy adhesive, this information was also used to propose the adhesive failure factors occurs. The strength of adhesive was related to the cross-linked of particles at different levels of temperatures. The higher strength of adhesive joint also was proposed, in which near glass transition temperature of the fully cured network. Beyond the glass transition temperature of the fully curednetwork, T goo the thermal degradation iiritiate on the adhesive whereby the changes of physical properties occurs. In experiment outcomes, 2.0 mm is an effective adhesive thickness of adhesively bonded T -joint for temperature ranging from 55 °C up to 100 °C. Besides that, 1.0 mm and 1.5 mm obtained had optimum strength at room temperature and 35 °C respectively. The highest tensile stress of 1.9063 MPa was obtained at 35 °C would refer to all ranges of bond line thicknesses. This argument has been supported in physical properties, where at this condition; adhesive reached the optimum glass transition temperature of the fully cured network T goo value. The joint prediction from FEM calculation was made. It is found that the rupture occurs when the Von-misses stress obtained on the FEM of the T -joint reaches the adhesive strength and concluded to be the joint strength. Therefore, a simple relationship between the mechanical properties of the adhesive joint, adhesive strength at different level of adhesive thickness and thermal conditions was presented. Adhesive strengths shows more sensitive when Tcure < Tgoo. At 35°C, adhesive shows the highest strength for all range of adhesive thickness. Increasing cure temperature will increased the thermal degradation level due to the changes of physical properties and its composition. Thus, the degradation will reduce the adhesive strength. The evaluation of the temperature dependence of joint strength by comparing them at various temperatures with the value at room temperature has been accomplished. The development of finite element models, validation and prediction of adhesively bonded T -joint models subjected to static uniaxial loading has been accomplished. The results show the joint strength prediction performed by using elastic-plastic FEM which have significant consistence between the prediction and measured results.
  • Publication
    Microstructure and corrosion protection of magnesium alloy in conversion coating for manufacturing application
    (Universiti Malaysia Perlis (UniMAP), 2012)
    Nurul Farah Wahida Mohd Sidik
    Chemical conversion coatings have attracted significant interest in the study because of their potential to improve the corrosion resistance of alloys. Chemical conversion coatings are the most widely applied coating method due to their economic aspects with low cost and the promised results of the produced protective coatings. Previously, chromate compounds were widely used for producing conversion coatings to protect most metallic surfaces such as aluminum, steel and magnesium alloys. In spite of its toxicity hexavalent chromate (IV) has remain an essential ingredient in the metal finishing industry for corrosion control. But combining the economic impact of corrosion damage, the environmental and health problems caused by hexavalent chromate (IV), and the increasing the regulatory restrictions, scientists have a huge incentive to develop a new generation of environmentally friendly protective coating systems. This research focuses on a two-layer coating system, including a non-chromate conversion coating layer and a commercially available, self-priming top coating containing nontoxic corrosion inhibiting materials for AZ91D magnesium alloys. The objective of this research are to develop Sodium metavanadate (NaV03) conversion treatments for AZ91D Magnesium alloy in manufacturing application by using conversion coating method. Then, to investigate the microstructure of oxide film that formed on magnesium substrate and finally to study the corrosion behavior and corrosion protection of AZ91 D magnesium alloy so that it can be applied in manufacturing application. Sodium metavanadate (NaV03) is used as a corrosion inhibitor in this research. When used non-chromate conversion coating, an environmentally friendly anti-corrosion coating system would be obtained. Coatings that result from these processes are composed mostly of vanadium oxide phases. The operating parameters and conditions used to deposit the coating significantly influence the quality and performance of the deposited film . Four critical steps in producing the vanadium oxide conversion coatings are surface preparation, vanadia coating concentration, treatment time and pH values. Three types of base solution whereas lanthanum nitrate, magnesium nitrate and lanthanum with magnesium nitrate were prepared on AZ91 D magnesium alloy in electrolytes containing various concentration of NaV03 ranging from lg/1 to 7gll. The morphologies, chemical compositions and corrosion resistance of the vanadia coating were characterized by Scanning Electron Microscope (SEM) with Energy Dispersive X-Ray (EDX) capability. The effects of vanadia solution on the corrosion protection performance of magnesium substrate were investigated by Potentiodynamic polarization test in 3.5% Sodium Chloride (NaCI). These results with use of magnesium nitrate solution for 5 gil NaV03 as an additive in 30 minutes of treatment time with pH 8.5 demonstrated that the conversion of vanadia coating is capable to be used in manufacturing application.
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  • Publication
    Ergonomic intervention in harvesting process in oil palm plantation
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Roejhan Md Kawi
    Most fannworkers in the small and medium Oil palm industry are using conventional method for harvesting works. Therefore, they are extremely exposed to the risk of shoulder muscle injury which is one of the musculoskeletal disorders (MSDs) problems. Referring to the Rapid Upper Limb Assessment (RULA), conventional harvest works was highly risk to undergo shoulder muscle problem due to extreme harvest posture with the repetitive and high of loading. Based on the body score result, there were 100% of respondent proven suffering shoulder problem. Hence the aim of this project is to identify proper working posture with design of palm oil harvesting ergonomic intervention device in order to replace the use of long arm sickle in conventional harvest. A comprehensive field study was conducted which focusing on conventional harvest posture by using Electromyography (EMG). Five male subjects volunteered to demonstrate these harvest posture conditions with four selected muscle activity and recorded by EMG and the signal data then plotted into scatterplot. By these findings, the analytical expression developed with proper harvest posture basis as a motivation in designing the intervention. The intervention is developed into prototype with mechanism system. A prototype field evaluation has been conducted to monitor the muscles activities with focus on same selected muscle by using EMG. Volunteered farmworkers is randomly picked to demonstrate the hruvesting process. The result shows reduction of selected muscle activity as compared to the conventional method due to working posture improvement. The Human Activity Analysis (HAA) was study to investigate the posture of the farmworkers during conventional and intervention harvest. There are five body conditions were simulated: L4- L5 compression, body load compression, axial twist compression, flex/ext compression and L4-L5 joint shear. Besides, the RULA's also shows better score as concrete evidence in improving body posture during harvesting work with this new method. As conclusion, optimized working posture along with the assistance of intervention prototype in oil palm harvesting process is suggested since the data provided in this research shows it could decrease the risk of shoulder muscle pain. This research also encourage of generating the innovation in designing new tools to increase the agriculture workers petformance.
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