Comparison and Analysis of AC and DC Discharge Voltage of Cable Defects Based on Electric Heating Co-Simulation

2020 ◽  
Author(s):  
Yi Lu ◽  
Yanfeng Gao ◽  
Siyun Wei ◽  
Yibo Zheng ◽  
Dangguo Xu ◽  
...  
Keyword(s):  
Electric Heating ◽  
Discharge Voltage ◽  
Dc Discharge ◽  
Comparison And Analysis

Sterilization by negative and positive DC plasma with a micro discharge gap at atmospheric pressure

2017 ◽  
Vol 31 (32) ◽  
pp. 1750296 ◽  
Author(s):  
Hua Li ◽  
Lin-Xiu Jiang ◽  
Yong-Rong Jiang ◽  
Jian-Min Zhu ◽  
Zhen-Cheng Chen
Keyword(s):  
Atmospheric Pressure ◽  
Ambient Air ◽  
Discharge Voltage ◽  
Electrode Structure ◽  
Dc Plasma ◽  
Stainless Steel Needle ◽  
E Coli ◽  
Dc Discharge ◽  
Sterilization Effect ◽  
Discharge Gap

A new needle-to-droplet electrode structure with a micro discharge gap (2 mm) was designed to achieve direct current (DC) discharge plasma in ambient air with the aim of using the plasma to sterilize liquids. Without using noble gases or an external air flow, we succeeded in generating both a negative and positive DC plasma at atmospheric pressure. The plasma was driven by a 0 to −20,000 V, 100 W DC power supply. A stainless steel needle with a tip diameter of [Formula: see text] and a 200-[Formula: see text] droplet of bacteria-containing liquid served as the electrodes. At atmospheric pressure and room temperature (23[Formula: see text]C), utilizing the negative DC plasma, the discharge time lasted 10 s; the results showed that the higher the discharge voltage, the more efficient the sterilization effect. Conversely, when we applied a voltage of −5.5 kV, we found that the sterilization effect was more efficient for longer discharge times. Our findings demonstrate that Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) can be killed in about 30 s. Our experiments show that our sterilization method required less time and was more efficient for positive than for negative DC plasma under the same conditions.

About definition of the local entropy rate of production in experiment of pulse electric heating

2020 ◽  
pp. 29-34
Author(s):  
Alexandr V. Kostanovskiy ◽  
Margarita E. Kostanovskaya
Keyword(s):  
Thermal Diffusivity ◽  
Electric Heating ◽  
Thermal Capacity ◽  
Entropy Rate ◽  
Initial Time ◽  
Local Entropy ◽  
Linear Mode ◽  
Electric Capacity ◽  
Definition Of ◽  
Pulse Electric

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho
Keyword(s):  
Interspecific Variation ◽  
Sperm Storage ◽  
Male Mating ◽  
Museum Collections ◽  
Storage Organ ◽  
Mating Plug ◽  
Males And Females ◽  
Comparison And Analysis ◽  
Imagej Software ◽  
Sexually Antagonistic Coevolution

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.

Improvement Of The Method Of Winter Concreting With The Use Of Heating Wires

2019 ◽  
pp. 51-58
Keyword(s):  
Harmful Effect ◽  
Electric Heating ◽  
Strength Development ◽  
Construction Sites ◽  
Dominant Position ◽  
Heating Wire ◽  
Hands On ◽  
Basic Parameters ◽  
Monolithic Structures

Long-term experience of application of a method of electric heating by heating wires of the monolithic concrete and reinforced concrete structures erected in winter conditions is analyzed. This method, developed by the author of the article, took a dominant position on the construction sites due to the simplicity and efficiency in comparison with the mass applied in those years, the method of electric heating of concrete with steel round and strip electrodes. The data on labor intensity, material and energy costs in comparison with the method of rod electric heating are presented. Step-by-step technological operations on preparatory works and electric heating of monolithic structures with the use of extensive hands-on material, which formed the basis for the development of technological regulations, supplemented by a number of new proposals to improve the technology of works, are concretized. In order to work out the optimal mode of heat treatment, the studies of the concrete thermal conductivity factor in the process of its heating and strength development were carried out. The method for calculation of the basic parameters of concrete electric heating is presented. For simplification of calculations, for a wide contingent of masters, superintendents and technical personnel, the nomogram , making it possible with sufficient accuracy under the construction conditions to calculate the necessary heating parameters, was developed. The necessity of grounding the heating wire remaining in the concrete to reduce the harmful effect of magnetic radiation from various appliances and household appliances on the human body is noted.

Effect of dc discharge treatment on adhesion properties of poly (ethylene terephtalate) films

2018 ◽  
Vol 0 (11) ◽  
pp. 2-5
Author(s):  
M.S. Piskarev ◽  
◽  
A.V. Zinovyev ◽  
A.B. Gilman ◽  
A.S. Kechekyan ◽  
...  
Keyword(s):  
Adhesion Properties ◽  
Discharge Treatment ◽  
Dc Discharge ◽  
Poly Ethylene

KANTHAL-A

Alloy Digest ◽  
1954 ◽  
Vol 3 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Electric Heating ◽  
Temperature Performance ◽  
Resistance Alloy

Abstract KANTHAL-A is a resistance alloy employed advantageously for heavily-stressed electric heating apparatus, and is particularly suitable for heating elements in industrial furnaces and ceramic kilns. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as joining. Filing Code: SS-16. Producer or source: Aktiebolaget Kanthal.

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