Elmy Johana Mohamad

Segmented Capacitance Tomography Electrodes: A Design and Experimental Verifications

A segmented capacitance tomography system for real-time imaging of multiphase flows is developed and presented in this work. The earlier research shows that the electrical tomography (ECT) system is applicable in flow visualization (image reconstruction). The acquired concentration profile obtained from capacitance measurements able to imaged liquid and gas mixture in pipelines meanwhile the system development is designed to attach on a vessel. The electrode plates which act as the sensor previously has been assembled and fixed on the pipeline, thus it causes obscurity for the production to have any new process installation in the future. Therefore, a segmented electrode sensor offers a new design and idea on ECT system which is portable to be assembled in different diameter sizes of pipeline, and it is flexible to apply in any number due to different size of pipeline without the need of redesigning the sensing module. The new approach of this sensing module contains the integration intelligent electrode sensing circuit on every each of electrode sensors. A microcontroller unit and data acquisition (DAQ) system has been integrated on the electrode sensing circuit and USB technology was applied into the data acquisition system making the sensor able to work independently. Other than that the driven guard that usually placed between adjacent measuring electrodes and earth screen has been embedded on the segmented electrode sensor plates. This eliminates the cable noise and the electrode, so the signal conditioning board can be expanded according to pipe diameter.

Multiphase flow reconstruction in oil pipelines by portable capacitance tomography

A portable capacitance tomography system for real-time imaging of multiphase flows is developed and presented in this work. The earlier research shows that the Electrical Capacitance Tomography (ECT) System is applicable in flow visualization (image reconstruction). The acquired concentration profile that obtains from capacitance measurements is able to imaging liquid and gas mixture in pipelines meanwhile the system development is designed to attach on a vessel. The electrode plates which act as the sensor has been assembled and fixed on the pipeline, thus it causes difficulty for the production to have any new process installation in the future. Therefore portable capacitance is a new approach technology on ECT system. The purpose of the system is for on-line monitoring of concentration profile in multiphase flow-rate measurement system for oil, water and gas flow in oil pipelines.

Electrical Capacitance Tomography: A Review On Portable ECT System And Hardware Design

Purpose – There are demands from the industry to have a modern application of Electrical Capacitance Tomography (ECT) system which is mobile and agile. One of the factors why such system is needed in the industry is because of the requirement to install the measurement sensors in a hostile and harsh environment which demands a special kind of ECT system. This paper will discuss the features of mobile or portable ECT which is more practical to be implemented in the harsh environment. Besides, the implementation of cloud computing and wireless technology in the portable ECT systems is also discussed. This review outlines some key features of portable or in another word mobile ECT as a complete system. Design/methodology/approach – There are demands from the industry to have a modern application of ECT system which is mobile and agile. One of the factors why such system is needed in the industry is due to the requirement to install the measurement sensors in hostile and harsh environment which demands a spec...

Direct rapid prototyping evaluation on multijet and fused deposition modeling patterns for investment casting

The continuation from rapid prototyping into rapid tooling technologies allows speedy fabrication of sacrificial patterns for investment casting process. Direct expendable pattern fabrication with intricate features using rapid prototyping techniques significantly reduces the fabrication cost when associated with single- or low-volume production. During investment casting process, rapid prototyping patterns are subjected to high melting temperatures, high viscosities, and high thermal stress such as dewaxing and shell mold cracking. Furthermore, ceramic shell may cause crack during melting and burning out of the patterns and also incomplete collapsibility. Although rapid prototyping process can build parts with high stiffness rapidly, the part surface suffered a staircase effect and shrinkage during investment casting process solidification. This paper presents a direct approach of multijet modeling and fused deposition modeling on acrylate- and acrylonitrile–butadiene–styrene-based materials to be used as expendable patterns for the investment casting process. Thermal analyses were conducted on the rapid prototyping materials that exhibit mass loss and expansion. Quality assessment and benchmarking were performed between the rapid prototyping and the metal part on accuracy, surface roughness, and part built time. It was found that both the materials have dimensional deviation when employed in investment casting process and acrylate patterns have better surface roughness as compared to acrylonitrile–butadiene–styrene patterns. Additionally, multijet modeling recorded a significantly shorter lead time when more than a single part can be produced during the rapid prototyping process. It was observed that the shell mold after burnout experiences cracking. Results also showed that acrylate-based materials decomposed above 500℃, meanwhile acrylonitrile–butadiene–styrene was above 600℃. Acrylate material had a coefficient of thermal expansion and linear dimensional deviation as compared with acrylonitrile–butadiene–styrene. No ash was observed in the ceramic molds when the part burnout temperatures are above 500℃ acrylate material and 600℃ for acrylonitrile–butadiene–styrene.

Direct investment casting numerical study for ABS P400 FDM materials

The purpose of this paper is to present the study of internal structure for investment casting Fused Deposition Modeling (FDM) , and compare it between open and closed ceramic cube . This research aims to introduce a new internal structure for investment casting FDM pattern. With modeling 3D-thermal condition with mechanical finite element analysis on cube ceramic shell open and closed type (during burnout stage) have been computed. As numerical observation the deformation stress for cube square 90° and hollow models with two variants cube open and closed have been evaluated by put the temperature at model. Model was be imposed until 700 °C. Several investigations indicate the probability of better performance for influencing factor drainage ability for each model. However the main scope of the paper is to compare the performance of model during burnout stage ( the deformation on ceramic shell ) . Therefore, a more analytical and practical approach will be good for future research for other mentioned factors. A new generation of internal structure (or a new build style) for investment casting FDM patterns is presented here. The significant reduction of critical loadings on ceramic shell will ensure investment casting foundries for using FDM patterns, which are by square 90° and hollow models.

3D Printer Patterns Evaluation for Direct Investment Casting

The term direct investment casting represents the employment of pattern fabricated by rapid prototyping technique have been reduce the cost and production lead time. The non-wax materials having robust ability on producing pattern in accuracy stability and clean burnout. However 3D printer (3DP) parts are powder based materials and not easily burnout during firing process. The purpose of this investigation were to evaluate the ZP150 powder materials as a sacrificial pattern to be used in investment casting (IC) process. Result shows powder based patterns of 3DP process failed to disintegrate completely even at high temperature during collapsibility investigations. However the pattern become brittle and easily remove by water pressure. Therefore the ceramic mould can be used for metal casting.

Design of non-destructive test on gold metal using parallel plate capacitance sensor: A conceptual framework

It is very important to verify the gold content of karat-gold jewelry in order to avoid fraud and to guarantee the identity and the integrity of a gold bar. There are quite a number of techniques which are used to verify the gold content. Gold testing methods such as fire assay, touchstone testing and hydrostatic weighing have been used since the early civilization. In this paper, a conceptual framework for a non-destructive test to check gold content using parallel plate electrical capacitance tomography is being proposed. At the early stage, the possibility of using this method is being simulated using Comsol Multiphysic software. A complete design of a system is yet to be designed which include the sensor design, the main controller unit design and the method of reconstructing the image from the collected data. The simulation process has shown promising results to make this concept works. When a material is placed between the parallel plates, the permittivity distribution can be observed and based on the distribution, image of object can be reconstructed. Furthermore, there are significant results when the size and the permittivity of the object are varies.

Velocity profile measurement of solid particles using LED as a light source

Optical sensors have been widely available and used in medical applications and industries for decades. Its design comes in a wide range of varieties where each are tailored based on its type, use, size, nature of investigated materials etc. In this work, we focus on the development and investigation of an optical sensing module, which uses Light Emitting Diode (LED) as the light source and LED photosensor as detector. This sensor is to measure the velocity of a solid particle in a gas flow inside a closed pipe. Various factors such as power dissipation, wavelength of the light source, switching time and cost are considered in the design process of this sensor. The cross correlation technique is used to determine the flow rate where small particles were introduced in a natural gas flow and they went through two distanced sets of sensor module. The LED beam source in the first set of sensor will be scattered when the particle crosses it then the corresponding photodetector will collect the light signal received and generates a pulse signal. The second pulse signal is generated when the particle crosses the second set of sensor after an interval of time. The time interval measured is used to calculate the velocity of the flow. An analysis of the received pulse signals is made to determine the best configurations of the sensors. At the end of this study, we were able to develop a simple, working, and cost effective sensing module.