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Characteristics and properties of activated carbon from bamboo filled Styrene Butadiene Rubber (SBR) vulcanizates
No full textMaster of Science in Materials EngineeringCarbonized bamboo and bamboo activated carbon (AC) were prepared via carbonization process and chemical activation process using potassium hydroxide (KOH) as activating agent. Carbonization process was conducted at different carbonization temperature (250, 450 and 650 ºC) with heating rate of 5 and 15 ºC/min. As carbonization temperature increased, the percentage of char yield decreased, however the carbon content increased. The BET surface area of carbonized bamboo increased with
increasing carbonization temperature and more pores were created as shown in SEM micrographs. Carbonized bamboo produced at 650 ºC with heating rate 15 ºC/min showed the highest potential to produce bamboo AC, subsequently used as filler in SBR compounds owing to its higher carbon content with higher BET surface area. Next, carbonized bamboo and bamboo activated carbon filled SBR (SBR-CGS and SBR-AC) compounds with varying filler loading from 10 to 50 part per hundred rubber (phr) were prepared. The effects of filler loading on the cure characteristics, physical and tensile properties were determined. Results showed that the improvement in cure characteristics for both SBR-CGS and SBR-AC vulcanizates. The physical properties of both filled SBR vulcanizates improved in terms of increment in hardness and decrement in resilience as
the filler loading increased. Besides, the tensile properties for both SBR-CGS and SBRAC vulcanizates also enhanced which the tensile strength and tensile modulus as well as elongation at break (EB) increased. The morphology studies showed that both filler dispersed homogeneously in SBR compounds, resulted in good filler-rubber interaction and consequently improved the tensile properties. Comparing both filled SBR vulcanizates, it showed that SBR-AC vulcanizates have better properties than SBR-CGS vulcanizates due to the porosity of bamboo AC filler. SBR-AC vulcanizate with 50 phr of bamboo AC exhibited optimum properties and was selected to be added with transpolyoctylene (TOR) as compatibilizer. Incorporation of TOR into SBR-AC vulcanizates showed slightly increment in tensile strength and reduction in hardness and tensile modulus as the compatibilizer loading increased from 2 to 8 phr
The effect of nickel, cobalt and tin on the evolution of microstructural and mechanical properties of Al-Zn-Mg-Cu alloys (7000 series) via casting, powder metallurgy and friction stir processing techniques
No full textDoctor of Philosophy in Materials EngineeringCasting and alloying, powder metallurgy (PM) and Friction Stir processing (FSP)
techniques were used to produce Al-Zn-Mg-Cu alloy of superior properties. The main
objective of this research is to improve the microstructure, mechanical properties,
corrosion and solid particle erosion resistance of Al-Zn-Mg-Cu alloys. Conventional
casting route includes the production of Al-Zn-Mg-Cu alloys with and without Ni, Sn
and Co additives using a semi direct chill casting technique, thereafter homogenization
treatment at different conditions to the as cast Al-Zn-Mg-Cu alloys had carried out.
Additionally, hot extrusion process at 450°C on some homogenized Al-alloys was
applied to induce working stress in the surface to improve its erosion resistance. Aging
at T6 (120°C/24h) and retrogression and reaging (RRA) at
(120°C/24h+180°C/30min+120°C/24h) were conducted on non-extruded and extruded
Al-alloyed samples. Comparison the strength and hardness values of Al-Zn-Mg-Cu
alloy underwent RRA, was about of 380 MPa and 211 Hv with similar Al-alloy of Ni
and Co additives underwent similar heat treatment after extrusion showed that the
maximum tensile strength acquired were on the order of 665 MPa and hardness of about
265 HV. On the other hand, powder metallurgy routes comprised both mixing and ball
milling (BM) processes. Al-Zn-Mg-Cu compacted from their as received powder
mixtures were produced. Other Al-Zn-Mg-Cu with Ni or/and Co or Al2O3 samples were
produced for comparison purpose. All the mixed and ball milled Al-PM alloys were
cold compacted and sintered under argon atmosphere at 650°C/2hr then and underwent
homogenization at 470°C/1.5hr, and followed by aged at T6 and RRA treatment.
Findings showed that the saturation limits of the alloying elements were changed. The
solubility of nickel in the PM Al-alloy underwent ball milling was extended. In fact, this
was the primary target of the mechanical alloying (MA) brought about by BM process
application. Additionally, there was a notable increase in hardness and the sintered
density for the BM Al-PM alloy of Ni and Co additives after the RRA process.
Microhardness of 107 Hv and an increase in the sintered density of 11.5% g/cm3 were
acquired as compared to the similar Al-alloy which underwent the similar sintering
conditions without additives
Application of program evaluation and review technique (PERT) and linear programming (LP) in project management
No full textMaster of Science in Engineering MathematicsThroughout the years, businesses execute a systematic change, such as constructing a building, merging with another company or making a new product. These changes lead to the management of a project. To construct a project, various dataflow are required. However, project management nowadays demand more complex products, higher quality outputs and faster development cycles. This will cause massive scale of planning a project which leads to massive cost. Therefore, this study aims for an optimization in managing a project. The Program Evaluation and Review Technique (PERT) which originally designed to plan a project that emphasizes the relationship between the times each activity takes and the resulting time and cost for the expected completion of the entire project. In PERT, a graphical network is used to illustrate the precedence or parallel relationship among the activities. It‟s also identifying the expected completion time of a project and the critical path where more resources should be concentrated to finish the project on time. However, the expected time of a project can also be shorten
to a certain level by the used of additional resources which is called crashing. Reducing the duration might include using overtime, assigning more labour and using more resources such as material, equipment and so on. These actions may result in higher cost
and lower quality. Thus, crashing decision can be formulated by using Linear Programming (LP). LP technique seeks to determine the optimization project cost. It is also boast efficiency of computational algorithm for problems with thousands of constraint and variables which analyse by using Excel Solver. In this research, PERT and LP are applied on a large-scale of projects which construct a new building consist of Administration Office and Medan Selera at the Main Campus of University Malaysia Perlis (UniMAP), Mukim Padang Siding, Pauh, Perli
Promoting social entrepreneurship for sustainable of economic development: a study of social enterprises in Malaysia
No full textDoctor of Philosophy in Social EntrepreneurshipThe principal contribution of this research would potentially provide viable ideas on how competitive firms may consider the best or most appropriate solution(s) to enhance their company performance and support the growth of sustainability economic
development in Malaysia as a result in maximising the Malaysian Global Innovation and Creativity Centre (MaGIC) support programmes, rooted by one of the government initiatives. This research aims to examine how the strategy and policy influences social enterprise performance, or otherwise. It explores the financial and non-financial support such as awareness, legal recognition and supportive policy structure, quality talent, access to sizeable financial capital and bureaucracy of government agencies, provided by the said organisation. Arguments put forward on what constitutes a holistic social
entrepreneurship framework in Malaysia, particularly the precursors and the outcomes.
The proposed conceptual framework addresses an important consequence of social
entrepreneurship agenda by the year 2018. The agenda comprises social inclusion,
which is to increase the number to 1000 social enterprises social enterprises and for the
Malaysian social enterprise sector to be self-sustaining, equitable, and people-centric in
order to empower impact-driven entrepreneurs, which is in line with the aspiration of
the Malaysian New Economic Model (NEM). These derived from the Open Innovation
Theory of Chesbrough (2003). A qualitative case study, content analysis, comparative
analysis research serve as the main methodology for this research. Data collected from
thirteen respondents using a semi structured interview guide with open-ended questions
and probes about people‘s experiences, opinions, perceptions, feelings and knowledge.
As for the data analysis technique of this research, the researcher chooses to use
software Nvivo 10. The findings may benefit not only social enterprises, but also policy
maker and its agencies, private sectors and higher learning institutions for future
research. The study includes observations and suggests five possibilities for continuous
promotion initiatives in social entrepreneurship and future social entrepreneurship
development
Fuzzy Sumudu transform
No full textDoctor of Philosophy in Pure MathematicsOrdinary differential Equations (ODEs) have long been used to model real-life problems. As times goes on, researchers realized that ODEs are no longer the best modelling tool, since they are inaccurate, especially when dealing with stuff that are surrounded by uncertainties. To deal with this, researchers utilized the fuzzy set theory to propose fuzzy differential equations (FDEs). Unlike ODEs which could not cope with uncertainties at the initial values, FDEs handle this efficiently. However, the methods that can be
used to deal with FDEs are very limited, and many of them are still at development stages. In this research, a new analytical method is proposed for solving a class of FDEs, including FDEs of integer order, fuzzy fractional differential equations (FFDEs), fuzzy partial differential equations (FPDEs) and system of linear fuzzy differential equations (SLFDEs). For this purpose, a novel integral transform called fuzzy Sumudu transform (FST) is proposed. This is done by integrating the fuzzy set theory and the classical Sumudu transform (CST). New properties and fundamental results concerning FST are proposed and proved mathematically. These new properties comprised results on duality with fuzzy Laplace transform (FLT), linearity, preserving, shifting, convolution, as well as theorems for fuzzy derivatives. The proposed results are then used to construct
detailed procedures for solving FDEs, FFDEs, FPDEs and SLFDEs where the class of FDEs are interpreted under the strongly generalized differentiability concept. From there, the procedures are demonstrated on some examples, in order to illustrate FST
applicability. Some analyses are performed where the behaviour of the solutions obtained are described in particulars. Furthermore, a comparison between the solutions obtained for the class of FDEs are compared with the solutions obtained using ODEs, where the ODEs include integer order ODEs, fractional differential equations (FrDEs), partial differential equations (PDEs) and system of linear differential equations (SLDEs). The main advantage of FST highlighted in this thesis is that it possessed the scale preserving property. This means that the transformed function, with a new domain, is a similitude to the original function. Additionally, this research provides an alternative for researchers when dealing with the class of FDEs
Soil stabilization application using geopolymerization method
No full textMaster of Science in Materials EngineeringSoft soils such as clay and silt have been associated to countless problems especially in engineering field. The main concern is to search for the best soil stabilizers to overcome the aroused problems. The purpose of soil stabilization is not only to achieve the
required soil engineering properties, in fact the cost and the effect towards the environment also should be considered. Continues studies are done by numerous researchers in order to find alternative methods for soil stabilization and geopolymerization is one of the method that can fulfill those requirements. This study has been conducted to investigate the geopolymerization method for soil stabilization application, by mixing the soils directly with alkaline solutions, producing soil based
geopolymer. This method was conducted towards three types of soil; kaolin, Soil 1 and
Soil 2. The soils were analyzed in terms of soil classification, Atterberg Limits,
chemical composition, phase and morphology for geopolymer fabrication. Meanwhile,
for the design of soil based geopolymer, the parameters involved were NaOH
concentration, solid/liquid ratio and Na2SiO3/NaOH ratio. The optimum mixing ratio
(solid/liquid ratio) of soil based geopolymers were obtained based on the highest
strength values in Unconfined Compressive Strength (UCS) test and California Bearing
Ratio (CBR) test. The highest strength value for kaolin based geopolymer was 436 kPa
for UCS test and 46% for CBR test. Both values were at the same optimum solid/liquid
ratio of 1.5. The optimum mixing ratio for Soil 1 based geopolymer was 2.0, with
highest strength value of 500 kPa for UCS test and 55% for CBR test. Soil 2 based
geopolymer also indicated the same optimum mixing ratio, 2.0, with highest strength
value of 620 kPa and 62% for UCS test and CBR test, respectively. The soil based
geopolymers were not effective for soil stabilization application according to ASTM
D4609 specification and did not comply the minimum value specified in the Design
Guideline for Alternative Pavement Structures (Low Volume Roads) of Malaysia Public
Work Department (PWD). Kaolin based geopolymer indicated reduction of plasticity
index up to 11.24%, meanwhile Soil 1 and Soil 2 based geopolymers indicated
reduction up to 3.08% and 4.31%, respectively. The characterization of soil based
geopolymers; phase analysis and morphology analysis were conducted at optimum
mixing ratio. The increment of strength values and changes in the characterization of
soil based geopolymers proved that geopolymerization method can be used for soil
stabilization application
Interlayer destabilization process of natural and commercial bentonite incorporated Ethylene Vinyl Acetate (EVA) nanocomposite with hybrid silicate nanofillers
No full textMaster of Science in Materials EngineeringNatural and commercial bentonites can act as efficient fillers to reinforce a polymer matrix if their strong interlayer binding forces are weakened to reduce tactoid formation. In this research, interlayers destabilization process was applied to gain a
loosely packed, swelled and disorganized clay layered structure for better polymer intercalation and filler dispersion during the polymer/clay composite fabrication. Three different destabilization methods were applied to the natural and commercial bentonites and their effects on swelling and platelets ordering/stacking of the clays were observed. The pristine and destabilized natural and commercial bentonites were characterized and compared based on their chemical component (XRF), chemical structure (XRD and
FTIR) and morphology (FESEM). Chemical analysis revealed that mineralogical and
chemical compositions of both types of bentonite affect their structure and swelling
capability during the destabilization process. XRD results suggest that basal spacing
(d001) of both natural and commercial bentonites reduced when single destabilization
process (by salt addition) was applied but increased when destabilization was done by
the combination of pH control and salt addition processes. The increment of basal
spacing was seen to be ~0.04 nm for both natural and commercial bentonites showing
that the destabilization process through combination of pH control and salt addition is
more efficient in swelling both natural and commercial bentonite clays. This is
supported by FESEM analysis where smaller, more loosely packed and uniform
platelets were observed due to swelling and weakening of the interlayer binding forces
of both natural and commercial bentonite clays. The ‘destabilized’ bentonites were used
as co-nanofiller with the organically modified montmorillonite (OMMT) to form hybrid
silicate nanofillers for EVA copolymer matrix reinforcement. Results show that the
‘destabilized’ bentonite prepared by the combination of pH control and salt addition is
most efficient in reinforcing the EVA matrix when combined with the OMMT by
allowing 124.9% increment in tensile strength, 13.5% in elongation at break and
190.8% in toughness values. Furthermore, thermal stability of the EVA nanocomposite
was also improved. This could be related to the improved dispersion of bentonite upon
the destabilization process that allows greater matrix-filler interactions in the
nanocomposite system. In summary, destabilization process through pH control and salt
addition is the promising and practical technique to improve the dispersion of bentonite
throughout the polymer matrix. Without the use of expensive and toxic chemicals, it
can be adopted as a new approach to swell bentonite for more environmental friendly
nanocomposite technology
Application of cubic timmer curve with countinuity on batik design
No full textMaster of Science in Engineerng MathematicsIn the world of CAGD, to create curve the research tends to use the curve that been usually used such as B-Spline and Bezier. Apparently, the researcher tends to choose cubic curve because it is easier to generate in coding that been created. In this study, Cubic Timmer curve that been chosen to create the curve based on chosen example which is a sample of Batik Design because advantages of Cubic Timmer curve is it tend to go through the midpoint of control polygon that brings a lot of help in creating the curve. Cubic Timmer curves that been created had C0 or C1 continuity by using Mathematica and MATLAB
software. After a sample of Batik design is chosen, the sample been inserted into
Mathematica then control points are selected. The control points that been selected are
insert into coding in MATLAB then been generated to have a curve. Among the curves
that been generated, the control point must be adjusted to make the curve having 1 C
continuity if the curves are not to be connected by 1 C continuity then it is 0 C continuity.
If the curve that been generated is not fulfilled the curve that desired then the control points
must be altered to have a good resemble curve as sample. The result is mimicking the
sample of Batik design perfectly since of its uniqueness properties that help a lot in
creating the curve
The effect of compatibilizer and coupling agent on properties and characterization of ethylene vinyl acetate / natural rubber / potash feldspar composites
No full textDoctor of Philosophy in Materials EngineeringThe composites of ethylene vinyl acetate/ natural rubber/ potash feldspar (EVA/NR/PF)
were studied. The composites were prepared by using Brabender Plasticoder at 160°C
with 50rpm of the rotor speed. The effect of PF loading, various types of
compatibilizers, and coupling agents on mechanical properties, swelling behaviour,
morphology properties, thermal properties, spectroscopy infrared, and XRD
characterization of the composites were investigated. In this study, 70 phr of ethylene
vinyl acetate and 30 phr of natural rubber were used as the polymer matrix. Meanwhile,
potash feldspar with 5, 10, 15, 20, and 25 phr was used as filler. Polyethylene-graftedmaleic
anhydride (PE-g-MAH), the combinations of isophthalic acid and maleic
anhydride (IAMA), ethylene vinyl acetate- grafted- phthalic anhydride (EVA-g-PAH),
and ethylene vinyl acetate- grafted- benzyl urea (EVA-g-BU) were used as
compatibilizer while silane coupling agent and glycolic acid- maleic anhydride (GAMA)
were used to modify the surface of PF. The addition of PF into EVA/NR
composites has reduced the tensile strength, elongation at break, percentage mass swell,
and interparticle spacing but improved modulus at 100% elongation (M100) and
percentage of crytallinity. The tensile fractured surface morphology had illustrated
agglomerations of PF at higher PF loading. At higher PF loading, the thermal stability
of the composites was found higher as temperature of decomposition and residual were
higher at higher PF loading. The compatibilized composites with PE-g-MAH, IAMA,
EVA-g-PAH, and EVA-g-BU showed an average of 3.19%, 4.72%, 11.24%, and 21.39%
respectively higher in tensile strength; 5.52%,23.69%, 38.49%, 21.25% respectively
higher in M100 than EVA/NR/PF composites. However, 3.97%, 5.51%, 6.24%, and
3.02% lower in elongation at break and 8.10%, 3.18%, 3.37%, and 3.66% lower in mass
swell percentage had been reported in PE-g-MAH, IAMA, EVA-g-PAH, and EVA-g-
BU compatibilized composites respectively compared to EVA/NR/PF composites.
Besides, the compatibilized composites presented higher thermal stability but lower
percentage of crystallinity, and interparticle spacing compared to EVA/NR/PF
composites. PF was treated with silane coupling agents and GA-MA in ethanol. The
increment of an average of 10.78% and 13.66% in tensile strength and 77.79% and
14.68%, in M100 were reported in EVA/NR/PFSilane and EVA/NR/PFGA-MA composites
respectively while the elongation at break and mass swell were decreased for the
composites. EVA/NR/PFSilane and EVA/NR/PFGA-MA composites exhibited lower
percentage of crystallinity and interparticle spacing but higher thermal stability in
comparison to EVA/NR/PF composites. The SEM morphology for all the
compatibilized and treated composites exhibited rough surface and indicated that the
interfacial adhesion had been improved
Preparation and characterization of nanostructured ITO Thin Films by Spray Pyrolysis Technique: Dependence on annealing temperature
Get PDFLink to publisher's homepage at http://ijneam.unimap.edu.my/Transparent conducting oxides (TCOs) like Indium tin oxide (ITO) have wide attention from
all scientists which have low resistance and high visible light transmittance, used as
transparent electrodes in many optoelectronic devices such as liquid crystal displays, touch
screens, light emitting diodes, and solar cells. In this research, the relationship between the
crystallization, optical transmittance, and surface roughness of nanostructured ITO thin
films and the change in annealing temperature was investigated. To enhance the efficiency
of this material in optoelectronic applications, both the optical transmittance in the visible
region and the crystallite size must be increased. These results can be obtained by the heat
treatment of the films. Nanostructured ITO thin layer films have been successfully prepared
at a substrate temperature equal to (350)℃ by chemical spray pyrolysis (CSP) technique.
The physical characterizations of nanostructured ITO thin layer films were investigated at
different annealing temperatures (400, 450 500)℃. The presence of diffraction peaks
indicates that the as-deposited and post annealed films are polycrystalline cubic structure
and the peak (400) is a preferred growth orientation. For all samples the value of intensity
of diffraction peaks increases with increasing substrate temperature. The crystallite size of
nanostructured ITO thin films is strongly related to the annealing temperature. The
crystallite size estimated from XRD was found to rise with rising annealing temperature. The
surface roughness of nanostructured ITO thin layer films increases with rising annealing
temperature. High values of transmittance have been measured in the visible region 550 nm
equal to (70, 82, 84 and 88)% corresponding to annealing temperature
(350, 400, 450 500)℃ respectively