Husna Abdul Rahman

Fiber Optic Displacement Sensor for Temperature Measurement

A simple design of a temperature sensor is proposed and demonstrated using a fiber optic displacement sensor based on an intensity modulation technique. The proposed sensor uses a plastic optical fiber (POF)-based coupler as a probe in conjunction with a flat surface aluminum rod as a target. The aluminum rod is placed within the linear range of the sensors displacement curve, which is from 0 to 1400 μm. The sensor is capable of measuring the temperature of an aluminum rod ranging from 42°C to 90°C with a measured sensitivity of 0.0044 mV/°C, with a linearity of more than 98% and a resolution of 2.4°C. The proposed sensor also shows a high degree of stability and good repeatability. The simplicity of design, accuracy, flexible dynamic range, and the low cost of fabrication are favorable attributes of the sensor and beneficial for real-field applications.

Fiber-Optic Salinity Sensor Using Fiber-Optic Displacement Measurement With Flat and Concave Mirror

A simple intensity modulated displacement sensor is proposed for sensing salinity based on different concentration of sodium chloride (NaCl) in deionized water. The proposed sensor uses a 594-nm He-Ne laser as light source due to the high absorbance of NaCl within that wavelength. The peak voltage and its position of the displacement from both flat and concave mirror are studied. For a concentration change from 0% to 12%, the peak voltage decreases linearly from 2.46 to 1.48 mV, while its corresponding position from the flat mirror increases linearly from 1.00 to 1.35 mm with a linearity of more than 96% and 99%, respectively. Similarly, the peak voltage corresponding to the displacement with concave mirror decreases linearly from 3.67 to 3.57 mV, while its position increases linearly from 1.20 to 1.45 mm with a linearity of more than 98% and 95%, respectively. From the experimental results, it is concluded that as the concentration or density of NaCl increases, the peak voltage decreases proportionately. The stability, high sensitivity, simplicity of design, and low fabrication cost make this sensor suitable for chemical, pharmaceutical, biomedical, and process-control application.

Initial investigation of brainwave synchronization after five sessions of Horizontal Rotation intervention using EEG

This research investigates the effects of five sessions of Horizontal Rotation (HR) on human brainwaves synchronization using EEG. EEG signals were captured from 42 participants before and after undergoing HR using two-channel bipolar connection in a controlled environment. The signals were filtered and classified into the four frequency bands; Delta, Theta, Alpha and Beta. Graphs were plotted and paired T-test analysis was used to demonstrate the correlation between left and right brainwaves before and after HR to verify brainwave synchronization. It was observed that after five sessions of HR, brainwaves were more synchronized for all frequency bands with highest increment of 37% in Delta band while the lowest increment is at 6% for Theta band. Thus, there was evidence that HR could synchronize brainwaves.

The preliminary study on the effect of nasyid music and rock music on brainwave signal using EEG

This preliminary study analyzes the effect of nasyid music and rock music on brainwave signal particularly focusing on alpha wave. EEG data were recorded from 30 students from Faculty of Electrical Engineering, UiTM age 18 to 27 years old. Students were interviewed before EEG recording to find out their music preference. Using EEG, the brainwave signal of the sample is captured twice, once before listening to the music and while listening to the music. Consequently, the brainwaves signal is analyzed and the comparison between these two music genres is discussed. The results demonstrate that 60–80% of the samples show improvement in the alpha band after listening to nasyid while only 56–66% improves after listening to rock music. These findings indicate that the alpha power increases when listening to the nasyid music compare to the rock music. Consequently, nasyid music in particular can result in a more relaxing condition compared to the rock music

Micro-Ball Lensed Fiber-Based Glucose Sensor

The compact micro-ball lens structure fabricated at the cleaved tip of a microfiber coupler (MFC) is proposed and demonstrated for sensing various glucose concentrations in deionized water. The MFC was made by fusing and tapering two optical fibers using a flame brushing technique. It was then cleaved at the center of the minimum waist region to form a ball lens at the tip by an arcing technique using a fusion splicing machine. The proposed glucose sensor uses the micro-ball lensed fiber as a probe and a mirror as a target. The working mechanism of this device is based on the observed reduction in the peak power of the sensor wavelength spectrum as the concentration of glucose is increased. For a concentration change from 0 to 12 volume%, the ouput intensity of the sensor decreases linearly from -57.4 to -60.5 dBm with a sensitivity of 0.26 dB/% and a linearity of more than 99%.

Relative Humidity Sensing Using a PMMA Doped Agarose Gel Microfiber

Humidity sensors rely on humidity-induced refractive index change in the sensing material despite the sensor configuration. Polymer-based microwires can absorb water vapor molecules and detect humidity changes without the need of further coating. However, the sensitivity-simplicity trade-off is still a challenge. Sophisticated coating methods, complex resonating structures, and nanostructured films are reported as methods to enhance the device sensitivity. A simple technique, to build a high sensitivity RH sensor based on an agarose-doped Poly Methyl Methacrylate (PMMA) sensor head, is demonstrated. The waist diameter and uniform length of the PMMA doped agarose gel microfiber were measured to be 6 μm and 10 mm, respectively. The sensor can achieve power variation of up to 2.9 μW in a wide relative humidity range (50–80%), and display linear response with a correlation coefficient of 98.29%, sensitivity of 0.421 dB/%RH, and resolution of 0.431%RH. This agarose-based optical sensor provides a beneficial complement to the existing electrical ones, and will promote the employment of agarose in chemical sensing techniques.

Analysis of correlation between BMI and human physical condition using resonant field imaging system (RFI)

This technical paper investigates the correlation of body mass index (BMI) and human physical condition using resonant field imaging system (RFI).The results show the state of health level of students using physiological analysis. Frequency measurement is taken for 40 students including male and female students of electrical engineering around 8 am to 6 pm. The objective is to investigate the relationship of different health condition with different BMI category such as underweight, normal, overweight and obese. Based on the results presented, it is concluded that the samples with normal BMI are generally healthier. This shows that there is a clear and direct psychosomatic connection to the area of bioenergy. It also implies that pure and high frequency electrofield energy is projected from parts of the body.

Analysis of brainwave dominant after horizontal rotation (HR) intervention using EEG for Theta and Delta frequency bands

This paper presents analysis of brainwave dominant after horizontal rotation (HR) intervention using EEG. It was conducted by interviewed all samples. Then, EEG signals were captured from the samples before and after under-going three sessions of HR. Basically, brainwave has four frequency bands which are Alpha, Beta, Theta and Delta. However, this paper will only focus on theta and delta. Paired T-test analysis was used and graphs were plotted to show the correlation between the left and right brainwave before and after HR intervention to verify brainwave dominant. It was observed that, after HR for all three sessions most of brainwaves were balanced but still some of brainwaves signals show unbalanced condition.

Modelling of all-optical symmetric Mach-Zehnder switch with asymmetric coupler

Ultra high-speed optical network is developing rapidly as growing capacity demand in telecommunication system is increasing. In these networks, it is desired to carry out switching, routing and processing in optical domain to avoid bottlenecks of optoelectronic conversions. Optical time-division multiplexing (OTDM) technique is one option to implement all optical networks. It provides a single data stream at a very high rate (>100 Gbits/s) using a single wavelength. These networks will be based on optical packet switching. The success of these networks depends on how well switching and routing are being done at this very high speed. An all optical switch based on symmetric Mach-Zehnder (SMZ) with asymmetric coupler (60:40) is proposed. Its characteristics and switching window profiles will be investigated. The results show that symmetric Mach-Zehnder (SMZ) with asymmetric coupler gives a better contrast ratio rather than symmetric Mach-Zehnder (SMZ) with normal 50:50 coupler.

Electrostatic charge interaction: a case study on tapered PMMA fiber for calcium nitrate detection

Purpose – This paper aims to propose and demonstrate a simple fiber optic sensor using a tapered plastic multimode fiber as a probe for measurement of calcium nitrate concentrations in de-ionized water. Design/methodology/approach – The working mechanism is based on the observed increment in the transmission of the sensor that is immersed in calcium nitrate solution of higher concentration. The tapering of the plastic fiber is carried out by etching method using acetone, sand paper and de-ionized water. Findings – Tapered fiber with diameter 0.45 mm gives the highest sensitivity of 0.028 mV/% due to better interaction between the evanescent field and the calcium nitrate solution with a good slope linearity of more than 98 per cent for a 1.07 per cent limit of detection in a straight probe arrangement. The use of calcium and nitrate ions within the sensing medium demonstrates the strong dependency of the sensor output trend on the electrolytic nature of the chemical solutions. Originality/value – Demonstra...