Rusnani Ariffin

Power quality analysis of Residual Current Device [RCD] nuisance tripping at commercial buildings

This paper concentrates on the case study on nuisance tripping of Residual Current Device (RCD) and equipment damage due to high neutral to ground voltage. The understanding of power quality elements is highlighted. The events of neutral to ground voltage disturbance are analysed by using CBEMA Curve. The events of neutral to ground voltage which occur outside the CBEMA Curve will easily contribute the above power quality problems. By implementing a proper grounding arrangement system based on TT, TN-S and TN-C-S systems and applying a separately derived system, the problems can be mitigated. With adequate wiring and proper grounding installation and by adding a separately derived source near to the load will eliminate the high neutral to ground voltage events.

Microwave Absorber Coating Material Using Oil Palm Ash

The most important part to be highlighted in developing a reliable microwave absorber is the material used to fabricate the absorber. As an alternative in managing the increase of the oil palm residues throughout the country, this study is focusing on developing a microwave absorber coating using oil palm fly ash. The software uses for design and simulation of microwave absorber is CST Microwave Studio (CST MWS) which enables the fast and accurate analysis of high frequency devices. The simulation design is fabricated to a number of layers which is coated by oil palm ash as a lossy element. The measurement and performance are carried out in the high broadband frequency of 8 to 12 GHz (X-band).

Studies of potential carbon coating for high frequency microwave absorber

An electromagnetic (EM) wave absorber is used to absorb the reflected wave that occurs on the wall of the chamber in the anechoic chamber. To date findings show that the construction of the absorber material used for the absorbers, ferrite is in the lead. A survey on materials that can be used as a carbon for the absorber is performed and the best carbon content is a mix of wood. The absorbers are made of elephant board and then coated with carbon. The absorber is measured for 10GHz frequency. The performances of the designed absorber are compared to commercial absorbers available in terms of the absorption performance.

Biological effects of WiFi electromagnetic radiation

This research is a continuous study from the previous research and concentrates on analyzing biological effects on blood count (hematology) and blood bio-chemistry. Radio signal generator was set to WiFi frequency of 2.4 GHz. This frequency is transmitted and radiated by using antenna towards 30 control samples of white albino mice. The antenna is placed at 1 meter distance to visualize the amount of radiation energy as normal situation for human in receiving WiFi signal. The radiation was exposed to mice continuously everyday for 8 hours and for 6 months period. For biological test, the control samples and exposed samples were taken to Veterinary Laboratory to undergo the blood test procedure on the second week of every month, for six months period. The blood tests were done to observe any changes in average packed cell volume (PCV), hemoglobin, red blood cell, and white blood cell and blood biochemistry tests. The spectrum analyzer was used to monitor the RF signal level received by the samples. The objective of this research is to study the effect of biological characteristics on WiFi radiation exposure to people. The methodology for this research is conducted on a laboratory with a few cages consists of 30 male mice and they were placed at a far-field distance of 1.0m from the antenna of the RF generator source. Another cage control which consists of 30 male mice was placed far away from radiation area, almost under free-radiation. The results were categorized into three tests that are Pathology Lab, Blood Count and Biochemistry Lab. From the tests, its shown that the degeneration occurs in the cells on some organs through histopathological procedures.

Comparisons on thermal effects Of 1.8GHz electromagnetic field exposure on Swiss Albino mice

Radio frequency (RF) and microwave (MW) radiation are electromagnetic radiation in the frequency ranges 3 kHz – 300 MHz, and 300 MHz – 300 GHz, respectively. While there have been many benefits from the use of RF frequency, people nowadays are concerned that a long-term exposure could affect their body biological system and health. The recent increase in the usage of mobile telephone has raised the public awareness on the effect of RF radiation. This research is conducted by setting up RF electromagnetic radiation experiment in such control environment to identify and study the devices that have potential to release any RF frequency that may effect on human health. The study for this research project concentrates on the radiation 1.8 GHz of RF on life sample since GSM1800 is commonly used around the world in mobile communication voice data calls. The GSM frequency bands or frequency ranges are the cellular frequencies designated by the International Telecommunication Union (ITU) for the operation of the GSM for mobile phones. Apart from that, a body temperature analysis between unexposed life sample and exposed life samples less than 1.8 GHz RF signals was conducted. The objective is to study the changes of body temperature effect on RF frequency exposure to Swiss Albino mice. A comparison is made between control cage mice which are free from any radiation and exposed cage mice. The main objective is to compare the effect in terms of their body temperature between male and female mice in control cage and exposed cage. The methodology was conducted by exposing mice to RF frequency within 2 months whereby the temperature was captured twice a day. This experiment also may assist to understand and study about the effects of RF radiation to life sample.

1.8 GHz Radio Frequency signal radiation effects on human health

Radio Frequency (RF) radiation effects are strictly relying on few critical factors, ie frequency, period of exposure and distance. Certain frequency ranges are absorbed in body tissue more than the other frequency range. The second factor is the duration of exposure. Where, over the period of time, the body will absorb more RF frequencies which hence will worsened the human tissue. The third factor is the distance of radiating elements from the human body. Hence, with respect to that unawareness of human towards the effects of the RF exposure, this project is carried out to simulate the base station radiation effects on human health. The experiments was conducted using mice as it has the closest DNA structure to human and the frequency used in the experiments was 1.8 GHz (i.e. GSM frequency). The mice were exposed at 1.8 GHz frequency, certain level of intensity and over a period of time. After certain duration, the mice were examined for its cellular changes. Second test conducted was the histopathology to examine the tissue of the mice out from the autopsy. The third test was the blood count on red blood cells, white blood cells, hemoglobin and packed cell volume. From the tests which are conducted at veterinar Lab, there are evidences of degeneration of cells in some organs through histopathological procedures. While in through biochemistry test, the level of blood calcium and phosphorus were decreasing and the level of blood creatinine was increasing. All this evidences show that, exposure to certaion level of frequencies will affect human body.

Design of portable mini anechoic chamber using low cost composite absorber

This paper presents the absorber in which it is designed and shaped to absorb incident radio frequency (RF) radiation. The absorber is designed using composite material since the significance of the project is to find a potential solution to construct a low cost anechoic chamber. This model of mini anechoic chamber, which is consisting of the new designed absorber, is portable and small in size so that it is more user friendly. The performance of the designed absorber are compared to commercial absorber available. The absorber that has been developed is a low cost absorber with the absorption rate is 16.6% less compared to the commercial absorber.

A pregnant women vest and window curtain as an RF electromagnetic shielding

This paper presents a case study on the health effects of a long-term radio frequency (RF) electromagnetic radiation that are generated from a radio base station (RBS). A questionnaire survey was conducted on a group of people who are staying near an RBS to study the general health effects and to study for any miscarriage effect. An RF signal site measurement was conducted to confirm that the site of the case study is under exposure of the radiation. Based on the measurement and survey results, a practical way to shield or reduce the radiation effect is proposed. An internal vest for pregnant women and a window curtain material for public use are tested, designed and proposed.

Cross-section absorption properties for broadband microwave

This article refers to the design technique related to the cross-section absorption properties of the materials absorbing electromagnetic waves. The methodology of construction of absorber, measurements of microwave absorption, description of the original laboratory set-up for measuring the absorption characteristics of the examined materials as a function of the shape of the absorber and the testing signal angle of incidence at different points on the absorber, were introduced. The results of the above mentioned measurements for two different shapes of absorber tested at three different angles of incident were published and compared with the commercial absorber. The expected result is that, how the absorption characteristics will be at different points on the absorber. The characteristics will be verified when the testing are done at different angles of incident.

Performance study of preliminary mini anechoic chamber fitted with coconut shell coated absorbers

An anechoic chamber is considered good when there is no signal reflection inside the chamber and also when there is no incoming signal from outside the chamber. The key element inside an anechoic chamber is the absorbing material. The evaluations of mini anechoic chamber fitted with coated absorbers were carried out by analyzing the absorption performance. The study includes the comparison of measurement with and without coated absorbers. The evaluations were carried out using 500 MHz, 2 GHz and 10GHz frequencies. The most significant result shows an absorption level of up to approximately 75% when the chamber was fitted with coated absorbers for 10 GHz.