Simulation study on electrical resistance tomography using metal wall for bubble detection

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

Eco-coalcrete : Waste-less earth, lively life

The palm oil industry and coal industry produce a large number of wastes which disposed of and created environmental pollution. Global demand for natural aggregates for the production of concrete is projected to grow by an average of 7.7% per year to reach 66.2 billion metric tons by 2022 (Kuhar, 2014). Using coal bottom ash (CBA) as partial sand replacement and palm oil clinker (POC) as granite full replacement in ECO-COALCRETE would reduce the use of natural resources. ECO-COALCRETE give a beneficial effect on the environment by lessening the quantity of CBA and POC thrown on landfill sites. ECO-COALCRETE which contains lesser sand and no granite as compared to plain concrete is acceptable for structure

Simulation of wire and arc additive manufacturing of 308L stainless steel with coldArc gas metal arc welding

This research focuses on the capabilities of coldArc GMAW in the behavior of heat input to the weld bead dimension. In this study, the effect of process GMAW of 308L stainless steel filler wire with a thickness of 1.2 mm and 304L stainless steel base plate, with a dimension of 120 mm x 25 mm x 10 mm (height x width x thickness) by applying WAAM. The data was collected using MATLAB of a Smart Weld Rosenthal’s Steady-State 3D Isotherms. A Taguchi response was used in the DOE method with Minitab software to analyze the effect of process parameters on height, width, and depth of weld bead dimension during GMAW. The experiments were conducted following the low, mid, and high input parameters will show the different structures of weld bead dimension, which include 70 A, 75 A, and 78 A (arc current), 15 V, 16 V, and 17 V (voltage), 400 mm/min, 600 mm/min, and 800 mm/min (welding speed). Hence, the optimum value is 75 A, 16 V, and 800 mm/min, and the most significant parameters to deposit stainless steel with coldArc GMAW were welding speed followed by arc current and voltage

Simulation study on non-homogenous system of non-invasive ERT using comsol multiphysics

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 nonhomogenous 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

Introducing an application of a charged coupled device (CCD) in an optical tomography system

A tomographic system is a method used for capturing an image of an internal object section. Optical tomography is one method which widely used in medical and industrial fields. This paper reviews several applications of Charged Coupled Devices (CCD) and introduces an application of a CCD in an optical tomography system. Most of the previous research used this component for displacement measurement and as a video camera. This paper discusses its basic principle of operation, basic construction, its criteria, application, and its advantages compared to other optoelectronic sensors available in today’s market. The applications of this sensor in fields such as astronomy and medical has proved the ability and the good performance of CCD in capturing images. This sensor should widen its usage in optical tomography fields because it can give high performance in image reconstructio

Conceptual knowledge in three dimensional computer aided design (3D CAD) modeling: a literature review and conceptual framework

The advancement of computing technology and widespread adoption on the use of 3D CAD modeling system has led the development of techniques and approaches to facilitate learning of relevant techniques in virtual modeling. This paper presents a review of literature on knowledge representation in CAD and proposed a new framework of conceptual knowledge in 3D CAD modeling. Findings of studies reviewed suggest that conception of knowledge representation in 3D CAD modeling has been dominated by approaches stressing on the development of a model within a single platform, not on variations of the modeling techniques and the way the system is used. A new knowledge representation in 3D CAD modeling is proposed to assist students to become a capable engineer

Optical tomography system: charge-coupled device linear image sensors

This paper discussed an optical tomography system based on charge-coupled device (CCD) linear image sensors. The developed system consists of a lighting system, a measurement section and a data acquisition system. Four CCD linear image sensors are configured around a flow pipe with an octagonal-shaped measurement section, for a four projections system. The four CCD linear image sensors consisting of 2048 pixels with a pixel size of 14 micron by 14 micron are used to produce a high-resolution system. A simple optical model is mapped into the system's sensitivity matrix to relate the optical attenuation due to variations of optical density within the measurement section. A reconstructed tomographic image is produced based on the model using MATLAB software. The designed instrumentation system is calibrated and tested through different particle size measurements from different projections

Effects of electrolysis on magnetic abrasive finishing of AA6063-T1 tube internal surface using combination machining tool

In this research, we studied the effects of electrolysis in the magnetic abrasive finishing of an AA6063-T1 tube internal surface. The finishing surface‘s hairline morphology was removed in a short time by physical characteristic transformation of the finishing surface in which the aluminum oxide film was formed during the electrolysis. Next, magnetic abrasive finishing was used to eliminate the oxidation layer and polish the surface to a mirror-finishing standard. The two-step process effectively improved the surface roughness in a shorter time. The morphology changes before and after the finishing process, was studied by surface roughness measurement and scanning electron microscope photographs. Notably, the pit or micro holes formation during the electrolysis on the aluminum oxide film was examined and its effect on the surface roughness was studied. The elements’ residual on the surface was investigated by X-ray photoelectron spectroscopy analyzer before and after the process to confirm the formation and removal of oxidation film on the finishing surface. The lower value for torque measurement in electrolysis combined process compared to the conventional method was due to the porous characteristic of aluminum oxide film

Effect of Surface States on Joining Mechanisms and Mechanical Properties of Aluminum Alloy (A5052) and Polyethylene Terephthalate (PET) by Dissimilar Friction Spot Welding

In this research, polyethylene terephthalate (PET), as a high-density thermoplastic sheet, and Aluminum A5052, as a metal with seven distinct surface roughnesses, were joined by friction spot welding (FSW). The effect of A5052’s various surface states on the welding joining mechanism and mechanical properties were investigated. Friction spot welding was successfully applied for the dissimilar joining of PET thermoplastics and aluminum alloy A5052. During FSW, the PET near the joining interface softened, partially melted and adhered to the A5052 joining surface. The melted PET evaporated to form bubbles near the joining interface and cooled, forming hollows. The bubbles have two opposite effects: its presence at the joining interface prevent PET from contacting with A5052, while bubbles or hollows are crack origins that induce crack paths which degrade the joining strength. On the other hand, the bubbles’ flow pushed the softened PET into irregularities on the roughened surface to form mechanical interlocking, which significantly improved the strength. The tensile-shear failure load for an as-received surface (0.31 μ m Ra) specimen was about 0.4–0.8 kN while that for the treated surface (>0.31 μ m Ra) specimen was about 4.8–5.2 kN

Simulation Study on Electrical Resistance Tomography using Metal Wall for Bubble Detection

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