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This study aims to determine the characterization of organdy silk fabric samples that continuously or repeatedly experience negative corona plasma radiations under atmospheric conditions. The negative corona glow discharge plasma is generated by connecting the point electrode to the negative pole and the positive pole field electrode to the DC high voltage source. In a square configuration, one hundred point electrodes with a distance between points of 1.3 cm were used in this study. Meanwhile, the field electrode was a copper sheet with 20 cm x 20 cm dimensions. Plasma irradiation was carried out between the point and plane electrodes at a distance of 1.6 cm, 1.9 cm, and 2.2 cm. The organdy silk samples, placed between the two electrodes, were irradiated continuously and repeatedly for 5, 10, 15, 20, 25, and 30 minutes. The drip test was carried out on the irradiated samples by dripping 1 mm of water in 12 places on the samples. SEM obtains microscopic images of the irradiated samples. Irradiation on organdy silk fabric samples changed the nature of the fabric from hydrophobic to hydrophilic. The longer radiation time makes the sample easier to absorb water. Repeated or continuous radiation treatment of the sample did not show any significant difference in the sample's ability to absorb water. The Scanning Electron Microscope test results of the sample showed some blisters and damage to the irradiated sample. When performing a continuous irradiation process, blisters and sample damage progressively occurred compared to when the samples were irradiated repeatedly. [ABSTRACT FROM AUTHOR]

This study aims to determine the effect of two-fabric surface positive corona plasma radiation on the characteristics of organdy silk fabrics. The plasma generator uses a plasma reactor with a point-to-plane configuration. One hundred points stainless steel needles were used as the point electrodes and served as the anode electrodes. The cathode electrode, where the organdy silk samples were placed, was made of a copper board. The sample's characteristics were analyzed using the Scanning Electron Microscope (SEM) method, the Fourier Transform Infra-Red (FTIR) method, the X-ray Fluorescence (XRF), the Mechanical strength test, and the water absorption time test. Sample irradiation by positive corona plasma discharge reduces the water absorption time and optimally after 20 minutes of irradiation. Mechanical strength testing of the organdy silk properties showed an increase in the tear resistance value of the irradiated fabrics increased compared to without irradiation at the optimum time of 20 minutes irradiation. The SEM examination showed that the surface structure changes of the fabric affect the wettability and the tear resistance of the fabric. The FTIR test showed changes in the fabric functional group structure, dominantly on O-H, C-H, C-O, and C-N compounds due to 30 minutes of plasma irradiation. Elemental composition changes of Al2O3, P2O5, and K2O were observed after 30 minutes of plasma irradiation. In conclusion, positive corona plasma radiation improves the microscopic characteristics of the organdy silk fabric. [ABSTRACT FROM AUTHOR]

A transmission line is a vital backbone for electrical power delivery. Most of the electrical transmission in Java and Bali, Indonesia is dominated by a 150kV transmission line network. Java and Bali are considered volcanic islands, so the number of lightning strokes to the transmission line is more than two million every year. It was recorded that negative lightning stroke was dominated 93.03% of the lightning faults and positive lightning stroke took 6.97% of faults. A fault caused by direct lightning stroke to tower transmission may cause an electrical shutdown, so it is interesting to make an estimation of voltage breakdown at insulation string installed on the tower as lightning hits the ground wire on the top of the tower. This paper proposes the use of a tower model adapting the insulator string model attached to the surge impedance of tower transmission. The implementation of several different lightning waveforms to hits the tower model during simulation is aimed to calculate the maximum amplitude of voltage along the insulator string. If the voltage peak is above the critical flashover voltage of the insulator, then back flashover occurs and initiates the ground fault. The results and analysis of breakdown voltage obtained from this work give significant information to improve the performance of insulation string at electrical tower transmission. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the susceptibilities of a bilayer system which is comprised of ferroelectric (FE) and ferromagnetic (FM) material. At the interface between FE and FM, the magnetoelectric (ME) interaction exist, resulting in a ME coupling. The derivation of the susceptibilities of the bilayer system was started by determining the FE and FM energy densities. Then, the entire-cell effective medium method was employed to obtain effective susceptibilities of the bilayer system. As a result of the existence of ME coupling, we obtain not only ferromagnetic and ferroelectric susceptibilities, but also magnetoelectric and electro-magnetic susceptibilities. Here, magnetoelectric susceptibility relates magnetization and electric field while electro-magnetic susceptibility links the electric polarization and magnetic fields. We also found that the ME coupling also shifts the magnetic resonance frequency. [ABSTRACT FROM AUTHOR]