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Wireless power transfer for low power device using magnetic resonant coil
No full textDoctor of Philosophy in Electrical Systems EngineeringThe power is transferred wirelessly through a magnetic resonant coil as an antenna to transmit and receive the energy. This method no longer need complicated with the cable passing around us, with wireless electricity we can charge and make wireless electricity as an input source for electronic equipment such as Handphone, MP3 Player, everything works as a battery source or electrical wiring. The components used to build wireless power transfer can be divided into 4 parts components, transmitter section will convert Direct Current (DC) voltage to Alternating Current (AC) form then receiver will
convert AC to DC form that compatible for low power device. Whereas, at receiver
section containing with receiver planar coil, receiver rectifier circuit, voltage regulator
Integrated Circuit (IC) and mobile phone battery. The DC source that connected to
transmitter was provided by the DC source regulator which voltage and current can be
adjusted separately. The transmitter coil is function to converts the DC power from an
oscillator to a high frequency AC power signal. This high frequency alternating current,
which is linked with the wireless power transmitting coil, would create an alternating
magnetic field in the coil due to magnetic resonant to transmit energy. In the wireless
power charger receiver section, the receiver coils receives that energy as an induced
alternating voltage due to resonant coil in its coil and a rectifier in the wireless power
receiver section converts that AC voltage to a DC voltage. Rectified DC voltage would
be feed to the load through a voltage controller section. That is, the wireless mobile
battery charger receiver section main function is to charge a power mobile battery
through magnetic resonant coil. From the overall experiment conducted from various
design transmitter and receiver circuit using transistor and mosfet, diameter, size and
type of materials of magnetic resonant coil. These factors are the norms and necessary
aspect of wireless power transfer for mobile phone charger. From the transmitter circuit
design using transistor and mosfet test for wireless power transfer by using magnetic
resonant coil, it shows that the mosfet IRFP450 has the highest efficiency comparing to
mosfet IRFZ44N, transistors BC639 and BD139. The receiver circuit design using full
bridge rectifier has the better output DC comparing to half bridge rectifier
Four inputs - one output fuzzy logicsystem for washing machine
No full textMaster of Science in Engineering MathematicsWashing machine is one of the electrical appliances that use sophisticated technology. Washing machines that are used today not only saving energy, but it is able to wash a lot of load. Therefore, the designers of washing machine have suggested the usage of fuzzy logic system for washing machine because this system allows the machine to perform effectively compared to the traditional method. In this study, four input and one output variables are considered. The input variables are type of fabric, type of dirt, dirtiness of fabric and weight of load, while the output variable is washing time. Eighty one (81) possible rules are developed by combining all the inputs using AND operator.
Mamdani inference engine is used in this study to find the crisp output. Fuzzification
process is used to determine the fuzzy input by setting up a crisp input first. The crisp
input for type of fabric, type of dirt, dirtiness of fabric and weight of load are 32, 55, 48
and 7, respectively. Referring to the Mamdani inference engine, a minimum
membership function from the input parts is truncated to the output for each rule.
Defuzzification involved the process of taking the maximum membership function of
the output from each rule and drawn in a single graph. The centroid is one of the
methods that used to find the crisp output of washing machine. The package of fuzzy
logic that contained in MATLAB software is used by inserting all the data available
therein. Based on the simulation shown by MATLAB, the washing time for four input
and one output variables is 35.5 minutes. Next, the result of washing time for four input
variables is compared with the washing time for three input variables. The same process
is used like before by developing 27 possible rules based on the combination all the
three input variables. Referring to the simulation in MATLAB, the washing time for the
input variables is 34.3 minutes where there is a slightly difference in timing between
these two comparisons. Hence, the simulation produced by MATLAB is comparable to
the washing time that generate by washing machine itself. When there is an increase in
the number of rules, the washing time increase slightly. In conclusion, as the number of
inputs increases, there are many options that can be made because the simulation
conducted involves all the existing rules
The development of university-based entrepreneurial ecosystem: a grounded theory approach
No full textDoctor of Philosophy in Entrepreneurship and TechnopreneurshipUniversity-based entrepreneurial ecosystem, a smart evolutionary offshoot of entrepreneurship is vastly unexplored in entrepreneurship research. This research employs the grounded theory approach to develop university-based entrepreneurial
ecosystem. Beyond quantification and hypothetical falsification, grounded theory, a unique qualitative typology was used to explore and explicate the dimensional differences in modeling an entrepreneurial paradigm for the development of universitybased entrepreneurial ecosystem in the research context. This substantive research involves key universities in the Western part of Nigeria. The finding of this study is a paradigm model with substantive propositions that are empirically grounded in rich
respondents’ data. This study concludes that the transformational development of
university-based entrepreneurial ecosystem is still relative to the transitive effects of
technological diffusion and entrepreneurship psychological ambience. In addition,
university-based entrepreneurship ecosystem is in proportion to significant
entrepreneurial incentivization and apparent universities’ networks characterization.
This research provides a theoretical foundation and enlightenment for policy makers in
developing nations, especially in the Western part of Nigeria
Design of photovoltaic and wind power hybrid system for DC air conditioning application
No full textMaster of Science in Electrical Systems EngineeringThe achievement of optimum performance for the hybrid system, besides having the
efficient design of the system, a lot of study on the behaviour of the weather needs to be
made because both of the resources hybrid system design can work better with the help
of the appropriate weather. The hybrid system managed to help the system to be more
stable and reliable in generating the power to charge the battery bank that acts as the
energy storage to provide the power to the load. In this particular project, the load of 12
V 630 W DC air-condition have been investigated and analysed in several parts such as
PV array and wind turbine output, weather and load performances and modelling using
HOMER software. For the normal system, the energy from both solar radiation and
wind are managed by the PV and wind using device controller separately. This
particular project, Smart Relay SR3 B261JD is used to manage the voltage from PV
module and wind turbine. The device operates as a controller to choose the greater
voltage that produced from either PV module or wind turbine. The selected power
source is used to charge 7 units of YOKOHAMA 100 Ah 12 V battery bank that total
up to 700 Ah using the Phocos CX-40 battery charger. The parameters investigated and
analysed are voltage, current and power of the PV array, wind turbine and the DC aircondition
load. This study finds that the PV energy is more reliable compared to wind energy and the hybrid
system could charge the batteries to support the load for 7 hours daily. This new approach to solar
wind hybrid system will create a platform for future researchers to explore
A preliminary study on structural and optical properties of heat treated NB2O5 nanostructure
No full textLink to publisher's homepage at http://ijneam.unimap.edu.my/Annealing is a heat treatment that alters the physical and sometimes chemical properties of
a material to improve their crystalline structure and other important properties. This work
presents the effect of post heat treatment on optical, structural, morphological, and surface
roughness of Nb2O5 thin films at different temperatures (200-700oC) which to the best of our
knowledge not been extensively studied yet. A clear modification in surface morphology and
other studied properties was obtained. XRD results show a significant enhancement in the
film’s structural properties such as a reduction in the dislocation densities and stress. The
optical properties of the treated films show a clear decrease in the transmission and energy
gap values which their values were found to reduce from (4.35 to 2.9) eV with heat treatment
up to 600oC and re-increase at 700oC. The surface roughness was also enhanced as a result
of increasing the grain size from (9.95 – 34.7) nm Finally, SEM images of the films show an
obvious change in their morphology and an increase in film uniformity as a result of heat
treatment. Therefore, heat treatment could be considered as a helpful method to control film
characteristics. Main result should be presented quantitativel
Laser treatment effect on fatigue characterizations for steel alloy beam coated with nanoparticles
Get PDFLink to publisher's homepage at http://ijneam.unimap.edu.my/Previous work investigated the effect of nano coating for steel beams on the fatigue
characterization and calculated that the coating for beams leads to modifying the fatigue
life and stress. Therefore, this work modifies the fatigue characterizations for beams by using
laser treatment. The main aim of this work is to modify the fatigue properties of steel
materials by using a coating surface, with nanoparticle materials, in addition to the laser
treatment technique, at the same time. The experimental work was divided into three parts;
first, the fabricated fatigue steel samples were coated by zinc oxide (ZnO) nanoparticle;
second, treatment of the fatigue sample by laser technique using (low-high) and (high–low)
loading; and finally, testing the fatigue samples to calculate the fatigue life and stress, with
and without laser treatment. A scanning electron microscope (SEM) was used to study the
surface morphology of the samples. In addition, the numerical technique, using the finite
element, was employed to evaluate the fatigue characterizations for steel samples and the
results were compared. The comparison of the numerical and experimental results shows
that the maximum discrepancy did not exceed about 10.86%. Finally, the treatment of
nanomaterials coated steel samples shows that the fatigue characterizations were more
than 35%
Synthesis and characterizations of nano magnetic particles (Co- Ni Fe2O4) Ferrite by Co-precipitation and biomedical application
Get PDFLink to publisher's homepage at http://ijneam.unimap.edu.my/Characterization of Cox-1Nix Fe2O4 nanoparticles (NPs) employing X-ray diffraction and field
emission scanning electron microscopy (FESEM) was accomplished simply by chemical coprecipitation,
FTIR and finally the Magnetic Resonance Spectrometer (VSM), the singlephase
cubic spinel structure in X-ray diffraction. In FESEM, micrographs of Co ferrites
nanoparticles that are virtually spherical can be seen with grain sizes of less than 20 nm.
Two absorption bands are visible in the FTIR spectrum, with values ranging from 400-600
cm. These beams show that all of the samples have a ferrite spectral composition.
Preparation of samples yielded M-H curves because of the tight turn, which means the paper
samples are soft magnetic material in the VSM. Antibacterial activity of Cox-1Nix Fe2O4 NPs
in limiting the development of isolated pathogenic bacteria Staphylococcus aureus and E.
coli was studied to compare their effects with the traditional antibiotics used before. Using
Cox-1Nix Fe2O4 nanoparticles, it has been found that the nanoparticles release ions into the
environment, which interacts with the group (-SH) of proteins, resulting in the defection of
bacteria's cell membranes and the subsequent cell death
Enhancement of engine performance by studying the effect of cam profiles design on Modenas motorcycle using 1-D simulation analysis
No full textMaster of Science in Mechanical EngineeringIn the automotive industry, enhancing and improving the engine performance is one of
the major work for improving the overall performance of the engine and vehicle. Every
iteration of the engine, will overcome the issues raised in the previous batch of the engine
as well as improve the brake power and brake torque of the engine. There are a lot of
aspects need to be considered in achieving this objective such as intake part, exhaust part,
camshaft and cam profiles.
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