Finite element modelling of electrostatic fields in process tomography capacitive electrode systems for flow response evaluation

Various aspects and results of 2-D finite element (FE) modeling of electrostatic fields in 12-electrode capacitive systems for two-phase flow imaging are described. The capacitive technique relies on changes in capacitances between electrodes (mounted on the outer surface of the flow pipe) due to the change in permittivities of flow components. The measured capacitances between various electrode pairs and the field computation data are used to reconstruct the cross sectional image of the flow components. FE modeling of the electric field is necessary to optimize design variables and evaluate the system response to various flow regimes, likely to be encountered in practice. Results are presented in terms of normalized capacitances for various flow regimes. The effects of key geometric parameters of the electrode system are presented and analyzed

Validation of Finite Element Modelling of Multielectrode Capacitive System for Process Tomography Flow Imaging

Finite element modelling of process tomography sensor systems is necessary for their CAD both for performance evaluation and design optimization. This paper involves the validation of finite element models of a 12-electrode capacitive sensor system for multiphase flow imaging. Various results of modelling have been compared in the form of standing mode capacitances and sensor sensitivity distribution with experimental data obtained from UMIST. There is good agreement between simulation results and experiments especially for high sensitivity regions inside the pipe

Green tea polyphenol-reduced graphene oxide: derivatisation, reduction efficiency, reduction mechanism and cytotoxicity

This paper reports on the derivatisation, reduction efficiency, reduction mechanism and cytotoxicity of green tea polyphenol-reduced graphene oxide (GTP-RGO). The reduction of graphene oxide (GO) at 90°C using a weight ratio (WR) of GTP/GO=1 resulted in the production of a stable GTP-RGO dispersion in aqueous media, as indicated by the results of ultravioletvisible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and the measurement of zeta potential and electrophoretic mobility. In addition, the results from UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis indicated the comparable reduction ability of GTP relative to the standard reducing agent, hydrazine (N2H4). The removal mechanism of epoxy group from GO via reduction reaction with GTP was investigated by implementing hybrid functional method of Becke-3-parameters-Lee-Yang-Parr (B3LYP)using Gaussian 09 software. The energy and frequency calculations showed that the GO reduction using GTP was more spontaneous and relatively took place faster than the reduction using N2H4, as evidenced by higher entropy change (ΔS) (0.039 kcal/mol·K) and lower Gibbs free energy (ΔG) barrier (58.880 kcal/mol).The cytotoxicities of GO and GTP-RGO samples were evaluated against human colonic fibroblasts cells (CCD-18Co). The GO sample was determined to be toxic even at low concentration (6.25 μg/mL), while the GTP-RGO sample possesses notably low toxicity at the same concentration. The cell culture experiments revealed that the incorporation of GTP led to a decrease in the toxicity of GTP-RGO samples

Computer Aided Design of Process Tomography Capacitance Electrode System for Flow Imaging

This paper involves various aspects and results for the computer aided design of capicitance electrode systmes used for imaging and measurement of two-phase flows. Various 2D finite element models of a 12-electrode system have been investigated to show the effects of a range of design parameters on system performance. Recommendations have been made for the selection of some these parameters which could give desirable system performance

Analisis Pengaruh Inflasi dan Pertumbuhan Biaya Produksi terhadap Profit Margin pada Perusahaan Food And Beverages yang Go Publik di Bei

The purpose of this research is to know how big influence of Production Cost Inflation and Growth in the companys profit margin than Food and Beverages. Analysis tools used in this study is panel data regression, a combination of two data time series and cross section can provide more data so that it will generate degree of freedom (df) is greater, to determine the effect between inflation and growth in production cost profit margin ratio. Based on the conclusion, it can be concluded that the rate of inflation and growth in production costs affect the level of corporate profit margins at the Food and Beverages during the period 2005-2008 with a coefficient of determination equal to 96.83%. Partially between the inflation rate did not negatively affect the profit margin between the rate of inflation while the growth rate positively affects the production cost. So that can be implicated to obtain a high level of profit margin, then for company management to pay more attention to the level of growth in production costs, such as looking for suppliers who provide raw material prices are much cheaper so that more efficient control of production costs. Keywords: inflation, production cost, profit margi

Analisis Break Even Point sebagai Dasar Pengambilan Keputusan Penetapan Harga Jual pada USAha Kecil dan Menengah (UKM) di Kota Banda Aceh

The purpose of this research is to analyse the break even point on selling price determination, to know the difference of selling price between the one which is stated by SMEs in trading sector in Banda Aceh and the one which is the result of break even point analysis, and also to know the correlation between the break even point and selling price. Type of this research is statistical descriptive analysis. Population in this research are SMEs listed in Dinas Perindustrian, Perdagangan, Koperasi, dan UKM in Banda Aceh. Based on certain criterias, there are 30 SMEs as the samples of the research. This research shows that there is a difference betweet the rate of selling price determined by the SMEs and break even point analysis result. Based on correlation test, there is positive significant correlation between selling price and break even point

Polyethersulfone/HFO mixed matrix membrane for enhanced oily wastewater rejection

The recent growth of oil and gas industry has led to the increase of oily wastewater release. Membrane technology has been in the spotlight in recent advancement to treat the oily wastewater. Fouling due to surfactant adsorption and/or oil droplets plugging the pore has become one of the major hindrances in most of the research on oily wastewater treatment. In this work, self-synthesized hydrous ferric dioxide nanoparticles (HFO NPs) via chemical precipitation method were incorporated in polyethersulfone (PES) to fabricate a novel nanocomposite mixed matrix membranes (MMMs) for ultrafiltration (UF). The morphologies and physicochemical properties of prepared HFO NPs and MMMs were characterized using Scanning Electron Microscopy (SEM) and Transmission electron microscope (TEM), contact angle goniometer, before further subjected to water permeation test and oil rejection test. It was found that contact angle of membrane decreased remarkably with an increase in HFO nanoparticle loading from 70° to 38° at which proved its improved hydrophilicity which led to a significant rise in permeate flux, achieving 168.06 L/m2h bar in comparison to 63.67 L/m2h bar shown by the plain PES membrane. Total rejection of oil (100% rejection) demonstrated by the MMMs has confirmed the superior potential of PES/HFO UF membrane for total purification of oily wastewater especially to be reused in oilfield and refinery processes as well as to be released to the environment

A Front Surface Optimization Study for Photovoltaic Application

In this paper, we presented a possible front surface optical enhancement of Si solar cell by optimizing the Antireflection (AR) and light trapping (LT) schemes. Conventional plasma enhanced chemical vapor deposition (PECVD) and in house hot wire chemical vapor deposition (HWCVD) tool was used to deposit Silicon Nitride (SiNX) layer and optimized at 668nm wavelength. This was followed by surface texturing of random pyramids to further enhance the broadband reflectance of the front surface. Broadband reflectance measurement using integrating sphere method showed achieved weighted average reflectance (WAR) value of as low as 1.8% and 1.5%, when 85nm SiNX was deposited on top of random pyramids structure using HWCVD and PECVD methods, respectively

Agent-Based Simulation Of Crowd At The Tawaf Area.

Every year during the Hajj season there is a concentration of more than two million people within the vicinity of the Masjid Al-Haram. Congested areas, such as the tawaf,, may reach beyond a safe level of four people per square meter during this peak period. The Tawaf area together with the Ottoman construction is able to accommodate up to 72,000 people (in a praying position). Simulation of the movement and behavior of such a huge crowd can be useful in managing this important event. One of the recent trends in modeling and simulation is the agent technology which has been used to model and simulate various phenomenon such as the study of land use, infectious disease modeling, economic and business study, urban dynamic and also pedestrian modeling. In this paper we use multi-agent based method to simulate the crowd at the Tawaf area. We present the architecture of the software platform which implements our proposed model and briefly report our early experience in using- Repast J which is an agent-based simulation toolkit to model the crowd at the area