Ruby is one of the most precious gemstones on Earth that is always high in demand especially in the jewelry industries. Due to its high value and very expensive, a lot of imitation of ruby has been made. This results in the rising of more complicated issues as gemologists need to perform the grading valuation very carefully and precisely. The current and common grading techniques mostly depend on human vision, which eventually leads to error. This paper aims to analyze the clarity of rubies gemstones using Charge-Coupled Device (CCD). The CCD detects the light intensity and then convert the light intensity value into the voltage value. The CCD sensor is very special in its architecture design, consisting of more than 1000 very small pixels that are sensitive to light sources. Based on the previous research, CCD has high sensitivity to laser light source with wavelength range within 430 nm to 650 nm. This research is going to prove that CCD is able to detect the clarity of various grading of the pink to blood-red ruby stones.

Concrete is the main component in construction of civil infrastructure. However, deformation in concrete such as crack or void may occur either on its early stage or during its usage. Hence, concrete evaluation is a need in determining its strength and quality status. Direct Ultrasonic Pulse Velocity (UPV) method is the most common non-destructive measurement adopted to assess the condition of concrete structure. However, problems arise when there is limited accessible surface to probe the ultrasonic transducers. Hence, this project is undertaken to analyse ultrasonic NDT by utilising different arrangement of sensors on tested concrete. The simulation of the homogenous and non-homogenous concrete system will be done by using COMSOL Multiphysics software. The output signal obtained from the simulation is used for the image reconstruction by using the sensitivity mapping technique. The results are then validated by assessing the actual model of concrete structure using direct, indirect, and semi-direct UPV probing in order to get the exact location of defects. Preliminary result shows that proposed method can help to improve the defects determination in concrete structure.

Electrical Capacitance Tomography (ECT) is one of the soft field tomography that widely used for the purpose of measurement and monitoring of multiphase flow. Common problem of the soft field tomography is low quality and unstable images in the pipe especially at the center section of the pipe. In this paper, an ECT system with a comparison between common approach and a parallel approach is presented. Simulation in 2 dimensions with 16-electrode is carried out to observe a potential projection. The COMSOL Multiphysics software is used to investigate the state and response of the electric field with this approach by exporting data with 128x128 pixels. Air bubbles as a phantom in the oil medium have been tested and analyzed. Linear Back-Projection Algorithm (LBP) is implemented using MATLAB software to obtain a tomogram. A Multi Scale Structural Similarity, MSSIM was applied to compare both approaches. Consequently, the resolution and quality of the pictures in the pipes can be distinguished. However, a further investigation is needed to improve the parallel approach for ECT system.

This paper presents the effect on potential distributions and current streamlines for Electrical Resistance Tomography (ERT) applying metal wall pipe. A conducting boundary approach was applied in the measurement part of the research and COMSOL Multiphysics software has been applied in this work to solve the forward problem of the system. Sixteen electrodes with gold plated material as the conducting surface and FR4 as the insulating material were implemented as the sensing plate in the research. The simulations showed that the sensing field will be deflected based on the conductivity distribution within its sensing region. The electrical potential of the system also varied accordingly.

Electrical capacitance tomography (ECT) is a non-intrusive and non-invasive internal visualization tool that facilitates improved quantification by producing cross-sectional distribution information for any kind of multiphase flow. In a coal-fired power station, there are some concerning issues such as the sedimentation of pulverized coal in the piping system before it reaches the boiler system and the non-uniformity of its velocity, which contributes to a reduction in electricity generation and higher carbon dioxide emissions. The aim of this paper is to provide a review based on various research works on pulverized coal that utilized ECT system. This paper also consists of principle of ECT, image reconstruction, and velocity measurement. Further research and works will be executed based on the preliminary data gained to improve the existing works.

The paper aims to investigate the possibility of an invasive method for electrical capacitance tomography system for steel pipe application. This work presents the development process for modeling an ECT (Electrical Capacitance Tomography) sensor using COMSOL Multiphysics. COMSOL Multiphysics software is implemented as the main tool to model the ECT system. The 12 electrodes are modeled in 2-dimensional and it is based on the invasive approach. The ECT system is developed to obtain the electrical potential distribution between electrodes when an electric field is applied. Besides, it also obtains the permittivity distribution inside the closed pipe. This invasive approach is applied for the steel pipe that cannot be used with common ECT. Several positions of bubble air as the obstacle in the oil medium are tested. As a result, the sensor readings performance inside the region of interest is analyzed. Simultaneously, the tomograms are also obtained and analyzed using MATLAB software. A linear back-projection algorithm is implemented to reconstruct the image of the region of interest. Thus, the possibility of the ECT system applied for steel pipe can be observed and compared when there is a change of readings between the full oil and the existing obstacle inside the steel pipe. Besides, the tomograms for each condition tested can be observed. In short, the invasive approach for ECT is seen to be possible to apply for oil-gas application in steel pipe. The LBP algorithm with the average MSSIM value around 0.3 was able to detect the oil-gas regime inside the steel pipe.

Electrical resistance tomography (ERT) is a widely used in geophysical application. The purpose of this paper is to investigate the possibility of ERT systems to detect leakage or cracking of houehold underground pipe. A COMSOL Multiphysics software is implemented as the main tool for modelling ERT systems. 8 electrodes were modelled in 2 dimensions. At the same time, tomograms were also obtained and analyzed using MATLAB software. A linear back projection algorithm is implemented to reconstruct the image of the attractive area. Several different size and positions of underground leaking were analysed. The average value of MSSIM for all results in 0.01. This is because the smearing effect occurred when the linear back projection was implemented. In summary, a non-invasive strategy based on ERT is projected to be deployed for detecting leaks or cracks in underground pipes, but more research is required.

Non-destructive test (NDT) is widely used in industrial applications due to its reliability as well as flexibility. Rather than other methods, NDT is more suitable and practical to be performed in order to detect flaws and deterioration in concrete structures. This paper provides a review by studying various research works on concrete by performing ultrasonic technique NDT. In particular, the working principle of ultrasonic NDT, type of sensor and techniques adopted in ultrasonic NDT are briefly described in this paper. Further research based on preliminary data will be conducted to improve previous experimental work.

This paper presents a hardware design, arrangement and measurement for optical tomography where optical tomography uses light sources as the transmitter and photodiodes as the receiver. By using parallel projection for 44 laser transmitters and photodiode receivers at the cross-sectional boundary, the existence of bubbles inside a vertical column pipeline is determined. Octagon modelling with an eight-sided jig is used for projection and the measurement method for this research is shown. An offline technique is used to collect readings from each signal and the image is reconstructed from the data received.

This research presents an application of Charge-Coupled Device (CCD) linear sensor and laser diode in an optical tomography system. These optoelectronic sensors are believed to detect solid objects rather than transparent objects. Based on the research results, the development of optical tomography system using CCD and laser diode has helped to enhance the potential of these sensors in detecting low opacity objects. Experiments for detecting a solid rod, transparent rod and air bubbles in non-flowing crystal clear water were conducted in this study. From the image reconstruction results, it clearly shows a cross-sectional image of a pipeline system with the existence and the exact location of opaque and transparent objects in multiphase flow detected by the orthogonal projection of CCD sensors and lasers. The information details of real-time multiphase flow that observed by this system can be transmit via wireless or wired data communication system.

This research presents an application of optical tomography for the detection of gas bubbles flowing in a liquid medium. In order to visualise the material inside the pipeline, parallel beam projection had been selected. However, while producing the image, some constraints such as diffraction and reflection in liquid medium will happen, where it will affect the flow accuracy of the result. Therefore, a laser source is used to produce a better image resolution. The column is exposed to a homogeneous light beam and then the ray is detected with the use of optical wave guided detectors. By using parallel projection for 44 laser transmitters and photodiode receivers at the cross-sectional boundary, the existence of bubbles inside a vertical column pipeline is determined. The voltage drop at the sensor directly shows the existence of bubbles between the transmitter and receiver. Linear Back-projection (LBP) is the algorithm that is used to reconstruct the image in real-time. In conclusion, the technique of using parallel beam projection with a laser source can improve the image quality in liquid phase and enables the percentage size of bubbles to be determined.

Electrical capacitance tomography (ECT) is categorized as a soft-field sensor which is non-invasive and non-intrusive instrument that can provide the visualization of cross-sectional distribution of any kind of multiphase flow. ECT would help in understanding the gas-solid flow interaction. This research is conducted to overcome some difficulties in measurement of gas-solid flows that exist in multiphase flows in pipelines or vessels such as the sedimentation of the solid and the velocity of the solid particles. Hence, the characterization of gas-solid two-phase flow by implementing an ECT system is necessary. Three objectives are set for this research which are the determination of an optimum frequency and amplitude for capacitance measurement of Poly-methyl methacrylate (PMMA) material by ECT system, the determination of the average solid velocity in gas-solid two-phase flow through cross-correlation method using Parseval’s theorem, and image reconstruction based on eight ECT sensors using Linear Back Projection (LBP) algorithm. This paper concise the theory of ECT system, existing works, proposed methodology, and the expected results.

Tomography system is a method that being used to reconstruct a cross sectional image in vessel or pipeline. This method is widely used in medical and industrial fields. The aim of this paper is to provide an overview of tomography system based on its basics construction, types of sensors, its applications in today’s industry, and image reconstruction. This paper review consists of literature citations which related with tomography system.

Ninety percent of the ruby stones available worldwide come from Myanmar. Malaysia is known to be one of the countries that have been importing ruby stones for precious stone industries, manufacturing industries, medical and dentistry applications. There are several gemology tools which are used to investigate the grading of ruby stones such as loop, microscope, and dichroscope. Nevertheless, these tools are highly dependable on human visual assessment and require years of experience that may lead to error since ruby stone quality is evaluated based on its clarity and transparency. Hence, this paper addresses a simulation study on the optical properties of ruby stones via Charge-Coupled Device (CCD) Tomography approach. This paper indicates the capability of CCD and tomography system to analyze the ruby stone optical properties through image reconstruction based on the previous research. Linear Back Projection (LBP) algorithm will be used to construct two-dimensional image reconstruction of varieties ruby stones. From these image reconstructions, the transparency and blemishes of ruby stones can be analyzed.

Industrial process pipelines are mostly known to be constructed from metal which is a conducting material. Bubbles or gas detection are crucial in facilitating the bubble columns performance. By employing the Electrical Resistance Tomography (ERT) technique, a simulation study using COMSOL has been conducted to investigate the effect of excitation strategy, bubble sizes and locations towards the metal wall system. As for the current excitation strategy, conducting boundary protocol has to be applied when it comes to metallic vessel to overcome the grounding effect. Bubbles with a greater size than 2 mm and especially the one that is located near the wall boundary are much easier to detect. Further potential improvements to the current design and image reconstruction of the ERT system are desirable to improve the detection of small and centred bubble.

The non-invasive sensing technique is one of the favourite sensing techniques applied in the process tomography because it has not a direct contact with the medium of interest. The objective of this paper is to analyse the simulation of the non-homogenous system of the non-invasive ERT using finite element software; COMSOL Multiphysics. In this simulation, the liquid-air medium is chosen as the non-homogenous system. A different analysis of the non-homogenous system in term of the different position of the single air, different size of the single air and the multiple air inside the vessel were investigated in this paper. As a result, the location, size and multiple air inside the pipe will influence the output of the non-invasive ERT system. A liquid-gas medium of non-homogenous ERT system will have a good response if the air is located near the source, the size of the air is large enough and it has multiple air locations inside the pipe.

The world developed rapidly to provide better standard of living to the human being. Industrial revolution 4.0 promising in great revenue, investment and technological advancement to the society and various sectors. This paper presents an overview of tomography system towards the industrial revolution 4.0. Tomography is essentially a technique for showing an image representation through solid objects, such as a pipeline or the human body, in the two-dimensional and three-dimensional cross sections. Several tomography sensors, including optical tomography systems, ultrasonic tomography systems and an electrical tomography system, are discussed in terms of their hardware and image reconstruction. To provide a clear view of tomography system, a few examples of tomography system application in medical and process industries are discussed.