453 research outputs found
Textile Diamond Dipole and Artificial Magnetic Conductor Performance under Bending, Wetness and Specific Absorption Rate Measurements
Textile diamond dipole and Artificial Magnetic Conductor (AMC) have been proposed and tested under wearable and body centric measurements. The proposed antenna and AMC sheet are entirely made of textiles for both the substrate and conducting parts, thus making it suitable for wearable communications. Directive radiation patterns with high gain are obtained with the proposed AMC sheet, hence minimizing the radiation towards the human body. In this study, wearable and body centric measurements are investigated which include bending, wetness and Specific Absorption Rate (SAR). Bending is found not to give significant effect to the antenna and AMC performance, as opposed to wetness that yields severe performance distortion. However, the original performance is retrieved once the antenna and AMC dried. Moreover, notable SAR reduction is achieved with the introduction of the AMC sheet, which is appropriate to reduce the radiation that penetrates into human flesh
Development of a semi-active car suspension control system using magneto-rheological damper model
In this paper, the development of a semi- active suspension control of quarter car model using fuzzy-based controller has been done. The quarter car model to be used here can be described as a nonlinear two degrees of freedom system which is subject to excitation from different road profile. The semi-active control is designed as the fuzzy control inferred by using two single input rule fuzzy modules, and the road model is used as the control force is released by actuating an electromagnetic shaker. To implement semi-active suspension system experimentally, the MR damper is used here as the adjustable damper. The MR damper is a control device that consists of a hydraulic cylinder filled with magnetically polarizable particles suspended in a liquid. MR dampers dissipate vibration by absorbing energy. Magnetorheological (MR) fluids dampers are very effective to control vibration, which use MR fluids to produce controllable damping force and provide both the reliability of passive systems and the facility of active control systems with small power supply. Due to their mechanical simplicity, high dynamic range, low power requirements, large force capacity, and robustness, offer an attractive means of vibration protection. The objectives of this are modeling of semi-active suspension system, developing controller and understanding the characteristics of the MR damper to provide effective damping for the purpose of suspension isolation or suppression car model. In this work pid, fuzzy logic and fuzzy-hybrid controller are used to control semi-active car suspension system
Design of a Low Voltage Class AB Variable Gain Amplifier (VGA)
A variable gain amplifier (VGA) is one of the most significant component in many applications such as analog to digital converter (ADC). In communication receiver, VGA is typically employed in a feedback loop to realize an automatic gain control (AGC), to provide constant signal power to baseband analog-to-digital converter (ADC) for unpredictable received signal strengths. Gain range, power consumption and bandwidth of ADC are strongly influenced by the performance of operational amplifier. VGA is the key element for amplifying process in ADC. However, current class AB VGA is experiencing the limit of bandwidth, which is not suitable for high speed automatic gain control AGC. In order to overcome these limitations a high linearity and wide bandwidth of VGA is indispensable. The aim of this research is to get higher gain and larger bandwidth for VGA. In this research, a low cost, low power voltage and wide bandwidth class AB VGA is designed to mitigate this constraint. Superiority of the proposed VGA has been confirmed by circuit simulation using CEDEC 0.18-μm CMOS process with the help of tools from Mentor Graphics in designing a 100-MHz VGA under 1V supply voltage draining total static power consumption less than 125uW. The results show that the circuit is able to work with high linearity and wide bandwidth by varying Rf and Rs. Therefore, the frequency response (Gain) and the wide bandwidth of this class AB VGA is better than previously reported class AB VGA. Consequently, this modified class AB VGA is appropriate for high speed applications
A novel green antenna phase-shift system with data acquisition boards
A novel green phase shifter system is proposed in this research. The system is developed by a combination of reconfigurable beam steering antennas and data acquisition (DAQ) boards. A combination of two reconfigurable beam steering antennas, located side-by-side, forms a spatial configuration structure with a fabricated ‘green’ element plank of rice husk placed in between. The concept of a spatial configuration technique has been ‘mutated’ by shifting the structure of spiral feed line and aperture slots of first beam steering antenna by as much as 45 ◦ . The PIN diode switches connected to the DAQ boards enable the intelligent capability of the spatial antennas. The activation of certain degree radiation patterns of either the first beam steering antenna or the second beam steering antenna depends on the memory of the DAQ boards — Beam Manager. When an intruder comes from the cardinal angles of 0◦/ 360◦, 90◦, 180◦, or 270◦, its range and angles’ location will be automatically detected by the first antenna through the output ports of the 1st DAQ: P1.0, P1.1, P1.2, and P1.3. The second antenna is then activated by the output ports of the 2nd DAQ: P2.0 up to P2.3, to adaptively maneuver the beam towards four different ordinal directions of 45◦, 135◦, 225◦, and 315◦
Investigation of Minkowski Patch Antenna with Meander Line Split Ring Resonator (ML-SRR) Structure
Abstract—The objective of this paper is to investigate the
effect of the meander line split ring resonator on the modified Minkowski patch antenna. In this work, a modified Minkowski patch antenna with meander line split ring resonator (ML-SRR)and quadruple-P shaped split ring resonator (QPS-SRR)structure is presented. This proposed modified patch antenna with SRRs structures achieved remarkable 2.644 dB of gain at the frequency of 2.402 GHz compared to the normal Minkowski antenna without SRR structures with only 2.348 dB. This antenna had been simulated in the CST Microwave Studio simulation software
Integrating Retrofit IOT Controller With Electric Power System For Manual Wheelchair
Persons with physical injuries and disability are struggling to get through places using the conventional handwheelchair The needs of many people with disabilities can be overcome with powered wheelchair, but some portion of this community is finding it difficult to operate standard powered wheelchair due to its big in size and epensive.. This project developed a smatphone phone-controlled wheelchair along with three types of virtual controller which is Joystick control, D-pad control and Voice control through the wireless communication.. It is also equipped with obstacle (ultrasonic) avoidance notification and microcontroller controls the motor that moved the direction either FRONT, BACKWARD, LEFT and RIGHT. The main objective of this project is to facilitate and increase the movement of people who are handicapped and the ones who are not able to move freely with the implementation of IoT platform where this platform could provide data visualization and able to analyze the wheelchair maintenance management and movement. In additional, this project analyzes distinct IoT monitoring system features, including battery level remaining and temperature control. the concept succesfully developed with integration of microcontroller in which provide desired performance control of the system to desired output with the synchronization of Internet of Thing feature
The opportunity of magnetic induction tomography modality in breast cancer detection
The needs for non-invasive technique in breast cancer detection could enhance and preserve the future of medical field in Malaysia as well as countries around the world. Breast cancer has become the main concern nowadays not only for women but for man as well. In overall, the risk of women getting breast cancer is higher than man due to the denser tissue of breast in women compare to man. Beside the unawareness for the disease, the reason which contributes to this increasing number of breast cancer reported is also due to the limitations arising from modalities such as MRI, Mammography, ultrasound and other modalities. An alternative to current technologies should be improved for early detection and treatment which causes no physical harm to patients if possible. Thus, non-invasive and better technology in detecting breast cancer is very much needed in the current market. This paper will be discussing the insights of Magnetic Induction Tomography techniques in breast cancer detection
Dehydration of traditional dried instant noodle (mee siput) using controlled temperature & humidity dryer
Drying process is an essential step to produce instant noodles. Yet, the industries especially Small and Medium Enterprises (SMEs), is seeking for an efficient method to dry the noodles. This paper discusses the performance of an invented drying system which employed heating and humidifying process. The drying system was tested using 30 kilogram of the raw noodle known as “Mee Siput”. Temperature controlled system were used in the study to control the temperature of the drying process and prevent the dried noodles from damage by maintaining the temperature of lower than 80oC. The analysis shows that the system was drastically decreased the humidity from 80% to 40% just after 200 minutes of the drying process. The complete dehydration time of noodle has also decreased to only 4 hours from 16 hours when using traditional drying system without sacrificed the good quality of the dried noodle. In overall, the invented system believed to increase the production capacity of the noodle, reduce cost of production which would highly beneficial for Small Medium Industries (SMEs) in Malaysia
Synthesised Schiff Bases As A Potential Corrosion Inhibitor Of Aluminium.
The use of inhibitors for the protection against corrosion in acidic media such as nitric acid, sulfuric acid and
hydrochloric acid is widely reported. Schiff bases, a group of compounds containing nitrogen atoms were found to
be efficient inhibitors for corrosion in acidic media. Some research work revealed that the inhibition efficiency of
Schiff bases was found to be greater than their precursor, amines and aldehydes
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