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Pengenalan kepada Prinsip-Prinsip Sains Biologi dan Kimia
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Energy encryption for medium field of wireless power transfer system
No full textMaster of Science in Electrical System EngineeringNowadays, the wireless power transfer (WPT) on mobile charging application of power transfer is the process of transferring power using WPT technology are progressing rapidly. The launching of more mobile embedded with WPT system make it as currently most demanding technology. In WPT, the main issue that being investigated are focused on power transfer efficiency (PTE), effective distance and the size of transmitter and receiver itself. Apart from that, the security of the power transfer is very important from transmitter to selected receiver must be completely secure. The failure to secure WPT
system has affected the process to transfer power from transmitter to correct receiver.
This thesis presents method which manipulates chaos theory to ensure the security of
energy is encrypted to transfer and recovered as security at the correct receiver efficiently
with higher security. In chaos theory technique, there are chaotic behaviour element
which being embedded using the logistic map and Lyapunov exponent for additional
security with matching the switching frequency of the transmitter and receiver. Chaotic
behaviour is triggered on each characteristic which are Lyapunov exponent, logistic map
and switching frequency. For this research, the application of WPT is focused on mobile
charging application and its security efficiency is tested through chaos theory. Thus,
detailed study is carried out by varying the power operation, distance of effective PTE
and the capacitor combination. The system is simulated using MATLAB programming
by creating and simulating WPT environment. The simulation took all the characteristic
and specification of mobile charging application which is resides within medium field
range. The operating frequency is around 100 kHz, operating power of 10 W and distance
are adjusted from 3 cm to 5 cm. The simulation is done by sample taking into account
that characteristic of chaos theory which are logistic map, Lyapunov exponent, matching
switching frequency and matching security key. Lyapunov exponent which triggered the
matching frequency process must be greater than 3.50. As for this research, the Lyapunov
exponent value is chosen by random and it is greater than 3.50. The sampling result shows
that, the power is securely transferred by the following data: delivered power of 10 W,
matching frequency of 102 kHz (±2% at 100 kHz) and matching security key for
transmitter and receiver of 1.02 and 0.86 respectively. As the conclusion, results show
that chaos theory technique is effectively employed for security of energy encryption
process. It also managed to transfer energy from a transmitter to the intended receiver.
This is proven by the utilization of chaos theory technique of transmitter encrypted power
at distance of 4 cm between the transmitter and receiver
Design and development of integrated transplanter and weedermmachine for system of rice intesification (SRI) cultivation in Malaysia
No full textMaster of Science in Product Design EngineeringSystem of rice intensifications (SRI) was practiced by community in Lembah Organik
Lentang, Kampung Lentang since 2010. Throughout the years, the paddy plots began to
grow in number. Since most of the SRI practices needed to be done manually especially
planting the seedlings and using conventional tools to kill weeds and loaming the soil, the
demand of machinery was inevitable. This is due to time consumed and numbers of
manpower needed to carry out the task. For example, weeding process need to be done 4
times for one season. A new chassis that is able to support mechanical weeder and
transplanter for SRI was developed. This project was designed to support SRI practices
among Malaysian farmers. Product design specifications were gained from rice farmers
situated at Kampung Lentang, Belantek, Kedah. Several concepts were generated and the
best was choosen for further development and analysis. New chasiss was developed to
replace the current agriculture tractor. The chassis was fit with small petrol engine and one
main wheel. It was designed to pull SRI weeder and transplanter mechanism. The weeder
mechanism was designed to loam three rows at once and able to be use for weeding process
up to 40 days of age. Finite element analysis software was used to identify potential failures
and subsequent rectification of the problem at the design stage. Some calculation was done
to determine force and torque that may act on design. Steel was chosen as material to
reduce fabrication cost. Stainless steel and aluminum were also initially considered as
suitable material for the design but was not chosen due to the cost is high. For the rice
transplanter, the transplanting mechanism uses linkage to drop rice seedlings on top of the
soil. This fits the SRI practices for transplanting the young seedling. It is not just able to
plant one seedling at one location but also plant the seedlings without removing it from
nursery soil, thus, eliminate possibilities to injure the seedlings. Motion analysis was done
to analyze the linkage movement. Finite element analysis also was done to determine
maximum stress for each linkage part. Two of the designed products were built into
prototype which are SRI Chassis and SRI Weeder and tested in actual working environment
at paddy field. The field trial shows SRI Weeder was able to reduce manpower by 67%,
working time by 42% and save 60% of overall operating cos
Epoxidized natural rubber 50 FBG sensor for pressure applications
No full textMaster of Science in Communication EngineeringENR50 Polymer coated Fiber Bragg Grating sensor is almost a perfect choice for satisfying requirement characteristic of pressure sensor. The conventional pressure transducers are not too precise in measurement, besides being highly exposed to electromagnetic interference, power fluctuations and has complicated cabling. FBG sensor shows that it has small size, low attenuation, quick response on time, immunity to electromagnetic interference, safety in hazardous environment, and flexible configuration. However, the nature of frangible of FBG sensor is quite dangerous without packaging and coating. Therefore, the ENR50 polymer selected in this study to be a coating as it also can enhances the sensitivity of FBG sensor. ENR50 becomes a good candidate in this research because it has lower Poisson Ratio, and Young Modulus, which means it more flexible and less stiffness.
Theoretical and experimental analysis was done to investigate the performance of ENR50 as FBG’s coating. Thus, the ratio sensitivity enhanced between the theoretical and experimental result of sensitivity was calculated. Beside, the ratio differentiation sensitivity of theoretical of ENR50 polymer coated FBG with bare FBG was also calculated. The performance of ENR50 coated FBG for type of pressure applications such weight and level or depth also analyzed to investigate which type of pressure applications more compatible with this kind of sensor. Theoretical result shows that ENR50 coated FBG was enhanced
the sensitivity of bare FBG about 4.146 x times higher for weight applications and 4.11 x times higher for level or depth application, and this totally proved that ENR50 polymer can enhance the sensitivity of FBG bare sensor. However, experimental result not achieves the theoretical expectation due to the some limitations in the experimental setup such as the accuracy of value pressure given based on physics calculation is not as accurate compared to pressure value from the pressure chamber
Experimental and analytical study of drilling hybrid glass/carbon fibre reinforced epoxy composite
No full textDoctor of Philosophy in Manufacturing EngineeringHybrid composites have become increasingly attractive in research and development activities in recent times due to the capabilities to tailor their mechanical performance or characteristics to specific needs. Current research and innovation in the field of hybrid composites include processing, development and testing of metal matrix hybrid composites as well as the synthetic
and natural fibre hybrid composites. Nonetheless, a number of complications arise in the manufacturing processes, particularly in machining such as drilling, of these multiphase laminated materials. The fact is that machining of composites or hybrid composites presents a great challenge due to anisotropic nature of the material, lack of plastic deformation and
abrasiveness of the fibre reinforcements. According to the previous statistic studies,
unqualified holes leads to approximately 60 % part rejections during the final assembly process.
Therefore, this research study pursues an experimental and analytical approaches to extend the
fundamental knowledge in drilling hybrid fibre reinforced polymer (FRP) composites. Prior to
the drilling tests, the evaluations of the mechanical performance of hybrid FRP composite have
been attempted. Specifically, the hybrid effect of the plain woven carbon and E-glass fibres
hybrid composites within an epoxy polymer matrix was experimentally evaluated. It was
evident that the physical properties and mechanical strength of monolithic fibres composite
were enhanced 48 % by hybridising carbon fibres into the glass FRP composites. In addition,
theoretical analysis through the rule of mixture reveals that the hybrid FRP composites have
exhibited a positive hybrid effect in term of tensile and flexural behaviors. Even though
fabrication technology for the hybrid FRP composites has well advanced in the production of
near-net shape components, the secondary machining process is vital for completing the postmanufactured
of these materials. Thus, the desired setting for minimising the delamination
damage and surface roughness were determined using the Taguchi methodology and statistical
analyses
Formulation of fish feeds with high level of protein-bound methionine and lysine for African catfish (Clarias gariepinus) fingerling's growth
No full textMaster of Science in Bioprocess EngineeringThe high production of catfish will create demands on the fish feeds. The availability of local feedstuff ingredients in abundant can fulfill the needs of protein source in fish feeds. This research reports the new formulation of fish feeds with high level of proteinbound methionine and lysine and the effects on the growth rate, survival rate, feed utilization and digestibility of methionine and lysine on African catfish (Clarias gariepinus) fingerlings. Fish feeds were formulated by using potential feedstuff ingredients; earthworm powder, fish meal, soybean wastes, Leucaena leucocephala leaves, and rice bran. Each of the feedstuff ingredients was evaluated for their proximate composition including amino acid profile, crude protein, crude lipid, carbohydrate, moisture and ash content. The fish feed was formulated by using Design Expert software. Each of the formulated fish feeds was analyzed for their limiting amino acids (methionine and lysine). The commercial fish feeds act as a control diet. Fish feed with combination of 25.0 g earthworm powder, 20.0 g fish meal, 25.0 g soybean wastes, 10.0 g Leucaena leucocephala leaves and 14.0 g of rice bran, give the highest proteinbound methionine and lysine level (2.06 and 8.11% of amino acids in dietary protein respectively) among all diets and named as LyMet A. Feeding trial was conducted for 12 weeks to determine the utilization of selected formulated fish feeds towards African catfish fingerlings. The fingerlings, with a mean initial weight of 3.10±0.10 g were fed
twice a day at 5.00% of their body weight. The fingerlings fed with LyMet A showed the highest weight gain (1.68×103±13.6%), specific growth rate (3.20±0.01% per day) and methionine and lysine digestibility (92.3±0.11% and 98.4±0.01%, respectively).
The results indicate that LyMet A has an adequate amount of limiting amino acids (methionine and lysine) to fulfill African catfish fingerling diets without supplementation of synthetic amino acids
An interval-valued fuzzy set approach for evaluating students answer scripts in engineering mathematics 3 : a case study at Kolej Kemahiran Tinggi MARA Balik Pulau
No full textMaster of Science in Engineering MathematicsGenerally, education institutions must provide students’ evaluation reports regarding
their test or examination as sufficient as possible and with the unavoidable error as
small as possible. Therefore in this dissertation, the existing method had been used as
an alternative method for evaluating students’ answer scripts that is interval-valued
fuzzy set based on interval-valued fuzzy grade sheets. The marks for each question have
been awarded to the answer in the students’ answer scripts are represented by intervalvalued
fuzzy sets by an interval between zero and one. The degree of similarity between
an interval-valued fuzzy mark and a standard interval-valued fuzzy set will be
calculated by similarity function. An index of optimism, λ will be determined by the
evaluator. It is used to indicate the degree of optimism of the evaluator. Then, the
grading system based on fuzzy method will be compared with classical evaluation
method where the score is given one if it is true and zero marks when it is false. The
result of the evaluation between two methods shows that 70 percent of the 20 students
increase the marks. Besides that, 3 students increase their grade meanwhile 5 students
decrease their grading when using interval-valued fuzzy set method. It has also shown
that the range between the highest and the lowest marks for classical evaluation method
is 42 and for interval-valued fuzzy set method are 13. This dissertation help examiners
graded different assessment score in generating single score or grade and also help them
knowing the student's achievement level in the assessed course. This dissertation also
showed a good and successful fuzzy set theory application on student grading system.
An interval-valued fuzzy set method can evaluate students’ answer scripts in a more
flexible and more intelligent manner