M.H.F. Rahiman

Velocity Profile Measurement Using Digital Signal Processor-Based Optical Tomography System

The utilization of personal computer together with data acquisition system (DAS) as the processing tool in optical tomography systems has been a norm ever since the beginning of process tomography. However, the advancements in silicon fabrication technology nowadays allow the fabrication of powerful digital signal processors (DSPS) at a reasonable cost. This allows the technology to be applied in optical tomography system since data acquisition and processing can be performed within the DSP. Thus, the dependency of personal computer and the DAS to sample and process the external signals can be reduced or otherwise eliminated. The DSP system was customized to control the data acquisition process of 16 times 16 optical sensors array, arranged in parallel beam projection. The data collected was used to measure the velocity profile using sensor to sensor cross-correlation and pixel to pixel cross correlation.

Modelling of ultrasound tomography technique for Glass Fibre Reinforced Epoxy (GFRE) composites liquid transportation pipeline

The purpose of this paper is to model the ultrasonic tomography on the E-glass fibre reinforced epoxy composite pipe for process monitoring and control. Finite element software and mathematical estimation were applied to model and study the ultrasound wave propagation, especially the reflection and transmission coefficient. While there is a significant result achieved between mathematical estimation and finite element analysis with maximum percentage distinctly in 2.33.

Feasibility analysis of microwave frequency to detect wood for potential microwave application

Microwave frequency has the potential to assist and improve forest product industry in terms of quality and quantity. Consequently, it has been selected to perform non-destructive inspection on wood which is defected or contains resin internally. This paper describes an experiment to determine the relationship between the attenuation of microwave signals and the different diameters of the holes in tree trunks. This analysis can be used as a reference for an optimal setup for a new microwave tomography aimed at the inspection of valuable wood trunks.

Forward problem studies of electrical resistance tomography system on concrete materials

Electrical resistance tomography (ERT) is well known as non-invasive imaging technique, inexpensive, radiation free, visualization measurements of the multiphase flows and frequently applied in geophysical, medical and Industrial Process Tomography (IPT) applications. Application of ERT in concrete is a new exploration field, which can be used in monitoring and detecting the health and condition of concrete without destroying it. In this paper, ERT model under the condition of concrete is studied in which the sensitivity field model is produced and simulated by using COMSOL software. The affects brought by different current injection values with different concrete conductivity are studied in detail. This study able to provide the important direction for the further study of inverse problem in ERT system. Besides, the results of this technique hopefully can open a new exploration in inspection method of concrete structures in order to maintain the health of the concrete structure for civilian safety.