The Optimum Method for Determining the Corona Onset Voltage Gradient of Bundle Conductors on UHV AC Power Line

Shi-long Huang,Yun-Peng Liu 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

The COG (Corona Onset Voltage Gradient) of bundle conductors, as an important parameter in the design of transmission lines, is related to the electromagnetic environment around the transmission lines. Therefore, it is important to accurately determine the COG. At present, there are several methods to determine the COG, the values of COG obtained by diff erent methods are quite diff erent, and the reasonableness of these methods is still not clear. In this paper, combined with the UHV corona cage set in Ping’an County, Xining city (elevation 2200 m), the corona characteristic measurement system and UV imager, the platform for measuring corona discharge characteristics of bundle conductors was built. For the 8 × LGJ-630 bundle conductors commonly used on UHV transmission lines, the change of corona discharge intensity was observed by UV imager. Then, the E (fi eld intensity)– I (resistance current), the E – P (square root of corona loss), E – PH (UV photon number), E – RI (radio interference), E – AN (audible noise) curves were measured. By using the tangent method, the experimental values of COG were obtained. Finally, the COG obtained by the fi ve methods are analyzed and discussed, the COG values obtained by the E – I curve and E – P curve are basically the same, with a deviation of about 1.5%, it has clear physical signifi cance. While the deviation of the COG obtained by the E – PH , E – RI , and E – AN curves are about 10.4%, 29.9%, and 5.7%, respectively. And the optimal method proposed for determining the COG is E – I curve or E – P curve.

Distributed Functional Observer-based Event-triggered Containment Control of Multi-agent Systems

Long Jian,Jiangping Hu,Jun Wang,Kaibo Shi,Zhinan Peng,Yaoru Yang,Jiuke Huang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.5

This paper studies the containment control problem of linear multi-agent systems (MASs) with a directed graph, where the states of the followers will asymptotically converge to the convex hull formed by those of the leaders. By introducing the functional observer, a novel distributed event-triggered control strategy is presented to schedule communications between agents, which depends on the relative input and output measurements with its neighbors. Furthermore, the minimum inter-event time is guaranteed to be strictly positive. An example is presented to illustrate the feasibility and efficiency of the theoretic results.

Rice Husk as a Food Carrier Forselective Enrichment of Tea Catechins

Meng Shi,Long-Yue Huang,Rong-Rong Han,Qiao Lin, Jian-Hui Ye,Yue-Rong Liang,Jian-Hui Ye 한국차학회 2015 한국차학회지 Vol.- No.S

The potentials of rice husk, oat bran and soya milk cake as food carriers for tea catechins(TC) were studied. Adsorption properties, contact time and temperature effects and the concentration of tea catechins, as well as digestive stability were investigated in this paper. The result showed that the adsorption capacity of rice husk for tea catechins was 32.04 mgg-1 which was 28.1 % and 17.7 % higher than those of oat bran and soya milk cake and no obvious adsorbability to caffeine was observed for these materials. The selectivity coefficient K of EGCg to TC for rice husk was 4.44 in comparison with 1.87 and 1.96 of oat husk and soya milk cake. This guarantees rice husk a selective food carrier to tea catechins with enrichment of EGCg. Also, 20 min contact time and tea extract concentration above 1.75 g L-1 are recommended in order to obtain a high loading amount of tea catechins onto rice husk, and low temperature is favorable for the adsorption processof tea catechins onto rice husk. Digestive study showed that combination of tea catechins with rice husk was propitious to increase the digestive stability of tea catechins in simulated gastrointestinal fluids. Thus, rice husk is a promising food carrier for tea catechins. Further studies would be focusing on the identification and separation of the functional constituent of rice husk and its interaction mechanism with tea catechins.

Hollow-structured Pd/TiO2 as a dual functional photocatalyst for methyl orange oxidation and selective reduction of nitrate into nitrogen

Wen-Min Wang,Shi-Jer Tseng,Yu-Shuan Huang,Qian-Yuan Wu,Wen-Long Wang,Jerry J. Wu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

Nitrate pollution in wastewater has posed a threat to human health and the environment. Photocatalyticreduction is a promising technology to remove nitrate due to its high adaptability, low cost, and high efficiency. However, there is a great challenge to design photocatalyst with high nitrate reduction and highselectivity of nitrogen (N2) yield. In this study, a novel hollow-structured Pd/TiO2 (PHT1) photocatalyst issynthesized with large specific surface area (SBET) and pore volume, strong UV adsorption, high reductionpotential than nitrate to nitrite, high charge transfer rate, and low electron-hole recombination rate. PHT1 exhibits a superior photocatalytic activity on the removal of methyl orange and nitrate. In addition,PHT1 exhibits high N2 selectivity (>95 %). A lower pH can promote the reduction of nitrate and the selectivityof N2 by PHT1. Electrons (e-) and CO2– are the main active species for nitrate reduction with OH asauxiliary radicals. Three main pathways for nitrate reduction are proposed: i) the reaction with formicacid under acidic conditions; ii) the reduction by electrons and the loaded Pd of photocatalyst to captureelectrons to inhibit electron-hole recombination; iii) the reduction by CO2 – generated from formic acidoxidation by OH.

Experimental Investigation of Ion Mobility Measurements in Oxygen under Different Gas Pressures

Liu, Yun-Peng,Huang, Shi-long The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

In this paper, measurements of ion mobility were performed in oxygen at gas pressures of 44.52 - 101.19 kPa using the drift tube method. Over this pressure range, mobility values were within the limits of 1.796 to $3.821cm^2{\cdot}V^{-1}{\cdot}s^{-1}$ were determined and ion mobility shown to decrease non-linearly with increasing gas pressure towards a certain level of saturation. Ion mobility measured in air was lower than that measured in oxygen at the same gas pressure. Finally, a parameter correction method for calibrating the relationship between the ion mobility and gas pressure in oxygen was proposed.

Experimental Investigation of Ion Mobility Measurements in Oxygen under Different Gas Pressures

Yun-Peng Liu,Shi-long Huang 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

In this paper, measurements of ion mobility were performed in oxygen at gas pressures of 44.52 - 101.19 kPa using the drift tube method. Over this pressure range, mobility values were within the limits of 1.796 to 3.821 ㎠·V<SUP>-1</SUP>·s<SUP>-1</SUP> were determined and ion mobility shown to decrease nonlinearly with increasing gas pressure towards a certain level of saturation. Ion mobility measured in air was lower than that measured in oxygen at the same gas pressure. Finally, a parameter correction method for calibrating the relationship between the ion mobility and gas pressure in oxygen was proposed.

Fire Behaviors of Multilayer Latex Foam Coated by Thin Surface Fabric under Bottom Ventilation Conditions

Yiming Shen,Kai Zhang,Dongmei Huang,Chaoyi Wang,Chen Chen,De Li,Long Shi 한국고분자학회 2021 폴리머 Vol.45 No.1

The latex mattress is usually accompanied by fire risk due to its coating material and multi-layer structure. The fire behaviors of multi-layer (with a total thickness of 5 cm) latex foam coated with different fabric layer under bottom ventilation conditions were investigated experimentally. Experimental results showed that fabric coated on the surface of the multi-layer sample could significantly affect the fire behaviors. The combustion duration and peak mass loss rate of single layer sample were obtained 30% shorter and 25% larger than that of the coated samples, respectively. The effects of blending coated from the latex foam surface on the fire behaviors were found larger than those from the cotton coated sample. The total combustion duration and average fuel regression rate of cotton coated samples reduced by 34%, 43.2% when compared to those of the blending coated samples, respectively. With the increase of the number of latex foam layers, the fuel regression rate in the depth direction of the sample increases.

Cloning, Expression, and Characterization of a New Xylanase from Alkalophilic Paenibacillus sp. 12-11

( Yan Yu Zhao ),( Kun Meng ),( Hui Ying Luo ),( Pei Long Yang ),( Peng Jun Shi ),( Huo Qing Huang ),( Ying Guo Bai ),( Bin Yao ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.8

A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at 55℃ and was thermostable at 50℃ and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent Km and Vmax values were 1.18 mg/ml and 1,961 ?mol/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.