Application Of Data Mining For Reverse Osmosis Process In Seawater Desalination

Reverse osmosis (RO) membrane process has been considered a promising technology for water treatment and desalination. However, it is difficult to predict the performance of pilot- or full-scale RO systems because numerous factors are involved in RO performance, including variations in feed water (quantity, quality, temperature, etc), membrane fouling, and time-dependent changes (deteriorations). Accordingly, this study intended to develop a practical approach for the analysis of operation data in pilot-scale reverse osmosis (RO) processes. Novel techniques such as artificial neural network (ANN) and genetic programming (GP) technique were applied to correlate key operating parameters and RO permeability statistically. The ANN and GP models were trained using a set of experimental data from a RO pilot plant with a capacity of 1,000 m3/day and then used to predict its performance. The comparison of the ANN and GP model calculations with the experiment results revealed that the models were useful for analyzing and classifying the performance of pilot-scale RO systems. The models were also applied for an in-depth analysis of RO system performance under dynamic conditions

Design of Low Profile On-body Directional Antenna

Abstract-This paper proposes a low profile on-body directional antenna, which suits for on-body system. The antenna generates surface wave along the body surface in the industrial, scientific, and medical (ISM) band. The proposed antenna has a size of 65 mm × 65 mm × 2mm. On the human body equivalent phantom with the proposed antenna, simulated S-parameters show that the impedance bandwidth is lower than -10 dB. The proposed antenna is a good candidate for on-body applications

Design of a Wideband Antipodal Vivaldi Antenna with an Asymmetric Parasitic Patch

An antipodal Vivaldi antenna with a compact parasitic patch to overcome radiation performance degradations in the high-frequency band is proposed. For this purpose, a double asymmetric trapezoidal parasitic patch is designed and added to the aperture of an antipodal Vivaldi antenna. The patch is designed to efficiently focus the beam toward the end-fire direction at high frequencies by utilizing field coupling between the main radiating patch and the inserted parasitic patch. As a result, this technique considerably improves the gain and stability of radiation patterns at high frequencies. The proposed antenna has a peak gain greater than 9 dBi over the frequency range of 6–26.5 GHz

Numerical Study of Estimating the Arrival Time of UHF Signals for Partial Discharge Localization in a Power Transformer

Partial discharges (PDs) are electrical sparks that occur inside insulation between two conducting electrodes and can lead to the disastrous failure of insulation systems. To determine the location of a PD, a distributed array of UHF PD sensors is used to detect the electromagnetic (EM) signals emitted from the PD source, and the localization of the PD source can be estimated using the time difference of arrival (TDOA) between EM signals captured by the UHF PD sensor array. There are four popular methods to estimate the TDOA—the first peak method, the cross-correlation method, the energy criterion method, and the average time window threshold method. In this work, we numerically investigate the influence of noise on estimating the TDOA for the four different methods. Numerical results show that the energy criterion method is more robust against noise than other methods