scholarly journals An Experimental Study on Surface Discharge Characteristics of Different Types of Polymeric Material under AC Voltage

2013 ◽  
Vol 64 (4) ◽  
Author(s):  
N. Baharin ◽  
Y. Z. Arief ◽  
W. A. Izzati ◽  
M. Z. H. Makmud ◽  
Z. Adzis ◽  
...  
Keyword(s):  
Polymeric Material ◽  
Polymer Surface ◽  
Polymeric Materials ◽  
Ethylene Vinyl Acetate ◽  
Surface Discharge ◽  
Insulation Material ◽  
Discharge Characteristics ◽  
Different Types ◽  
Surface Discharges ◽  
Experimental Works

Surface discharge is a common electrical discharge that normally occurs on the surface of outdoor insulators and also causes the failure in the electrical insulation system. One of the causes of surface discharge is the presence of high voltage stress. Experimental works had been carried out to examine the surface discharge characteristics on polymeric samples as insulation material. The IEC (b) electrode configuration had been used to investigate the surface discharges phenomena of different types of polymeric materials with controlled of air relative humidity (RH). In these experimental works, three types of polymeric sample were selected, namely high-density polyethylene (HDPE), ethylene-vinyl acetate (EVA), and polystyrene (PS), respectively. The characteristics of the discharge are critically depending on the types of polymer. Surface discharges intensity, number of discharge occurrence, and surface morphology of each polymeric material were also investigated. Comparisons of these electrical characteristics were conducted among the samples. Results from the experiment showed that the EVA samples experienced severe degradation as compared to HDPE and PS samples.

Surface Discharge Characteristics on HDPE, LDPE and PP

2015 ◽  
Vol 785 ◽  
pp. 383-387 ◽  
Author(s):  
Sameh Dabbak ◽  
Hazlee Illias ◽  
Ang Bee Chin ◽  
Mohsin Ali Tunio
Keyword(s):  
High Density Polyethylene ◽  
Low Density Polyethylene ◽  
Surface Discharge ◽  
Insulation Material ◽  
Discharge Characteristics ◽  
Electrode Shape ◽  
Different Types ◽  
Surface Discharges ◽  
Main Factors ◽  
Materials Used

The degradation of polymer insulation is affected by many factors. One of the main factors is surface discharge. In this work, the characteristics of surface discharge on different types of polymer insulation material under different types of electrode shapes were studied. The insulation materials used were high density polyethylene (HDPE), low density polyethylene (LDPE) and polypropylene (PP). Different types of electrode shape used were sharp, flat and sphere electrodes. From the experiments that have been performed, surface discharge characteristics were found to be influenced by the type of insulation material and the electrode shape. Hence, a better understanding on the characteristics of surface discharges may be attained.

scholarly journals Biodegradation of Polymeric Material and Adhesive Properties of Cells of Microorganisms

2010 ◽  
Vol 4 (4) ◽  
pp. 305-309
Author(s):  
Gennady Zaikov ◽  
◽  
Klara Gumargalieva ◽  
Marina Artsis ◽  
◽  
...  
Keyword(s):  
Chemical Composition ◽  
Polymeric Material ◽  
Polymer Surface ◽  
Polymeric Materials ◽  
Chemical Components ◽  
Microscopic Fungi ◽  
Adhesive Properties ◽  
Hydrophobic Properties ◽  
Subsequent Degradation ◽  
Major Chemical

The chemical composition of cell membranes of microscopic fungi destroying polymeric materials is analyzed. The concentrations of the major chemical components – phospholipids, glycans, and amines – in nine types of fungi are estimated. The measured ratios of these components provide an estimate of the hydrophobic properties of conidia, controlling microorganism adhesion to polymer surface and subsequent degradation of polymeric materials.

scholarly journals Effect of High Voltage Impulses on Surface Discharge Characteristics of Polyethylene

2017 ◽  
Author(s):  
Roya Nikjoo ◽  
Nathaniel Taylor ◽  
Hans Edin
Keyword(s):  
High Voltage ◽  
Similar Case ◽  
Surface Discharge ◽  
Discharge Characteristics ◽  
Surface Flashover ◽  
Subsequent Application ◽  
Surface Discharges ◽  
Transient Voltages ◽  
Number Of Discharges

<p>This paper investigates the influence of high voltage impulses on the surface discharge characteristics of polyethylene (PE) during subsequent application of 50 Hz AC voltage. The investigation is done on two types of PE to examine the generality of the phenomena. The effect of impulses on the surface discharge features of PE are studied for both cases of having either a streamer or flashover. For each case, the consecutive surface discharges behave differently when the insulation has been exposed to the transient voltages. <br />The effect of impulses on surface discharge of PE is shown by the change of PD numbers and phase-resolved PD patterns. The results show a prompt change in the total number of discharges which decays with the time. After a surface flashover has occurred due to the impulse, the PD behaves quite differently compared to the similar case without flashover.</p>

scholarly journals Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 773
Author(s):  
Ahmad Safwan Ismail ◽  
Mohammad Jawaid ◽  
Norul Hisham Hamid ◽  
Ridwan Yahaya ◽  
Azman Hassan
Keyword(s):  
Mechanical Properties ◽  
Phase Separation ◽  
Polymer Blends ◽  
Epoxy Polymer ◽  
Flexural Modulus ◽  
Polymeric Materials ◽  
Morphological Properties ◽  
Comparison Results ◽  
Unique Material ◽  
Different Types

Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.

The modification of bitumen with styrene–butadiene–styrene, ethylene vinyl acetate and varying the amount of reactive ethylene terpolymer

2017 ◽  
Vol 50 (3) ◽  
pp. 241-255 ◽  
Author(s):  
Seyfullah Keyf
Keyword(s):  
Vinyl Acetate ◽  
Softening Point ◽  
Elastic Recovery ◽  
Ethylene Vinyl Acetate ◽  
Modified Bitumen ◽  
Penetration Index ◽  
Different Types ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

In this article, 50/70 penetration grade TUPRAS bitumen was modified. Reactive elastomeric terpolymer (Elvaloy RET; DuPont Company), ethylene vinyl acetate (EVA) and styrene–butadiene–styrene (SBS) polymers were used in bitumen modification. Set hours of the tests were applied to samples taken from the obtained modified bitumen mixture. Varying amount of reactive ethylene terpolymer with weight ratios of 0.5%, 1.0%, 1.5%, 2.0% and 2.5% were introduced to the mixture of raw bitumen with 1.0% SBS and 1.0% EVA. Penetration, penetration index, softening point, ductility and elastic recovery tests were performed with these modified bitumen and raw bitumen. The samples of raw bitumen and modified bitumens of 2.0% Elvaloy RET, 1.0% SBS and 1.0% EVA were investigated by means of IR spectroscopy. The raw bitumen was modified with SBS, EVA and RET, and it was determined that penetration and ductility values were decreased while penetration index, softening point and elastic recovery were increased. The purpose of this study is to research the improving properties of 50/70 penetration grade–modified bitumen used in highways of Turkey. The most important characteristics (such as softening point, penetration and % elastic recovery) of new polymer-modified bitumen (NPMB) containing 2.5% EVA, 1% RET and 1% SBS were compared with eight different types of polymer-modified bitumens in Turkey (TPMB). NPMB provided all required parameters (softening point, penetration and % elastic recovery) for five different types of TPMBs (TPMB 70-16, TPMB 70-22, TPMB 76-16, TPMB 76-22 and TPMB 82-16).

scholarly journals Effect of reinforcement material on impact properties of epoxy

2017 ◽  
Vol 2 (3) ◽  
pp. 226-231
Author(s):  
Basim M. Fadhil ◽  
Payman Sahbah Ahmed ◽  
Ava Ali Kamal
Keyword(s):  
Carbon Fiber ◽  
Impact Test ◽  
Steel Fiber ◽  
Matrix Composites ◽  
Impact Machine ◽  
Impact Properties ◽  
Different Types ◽  
Experimental Works ◽  
Impact Characteristics ◽  
The Impact

Impact characteristics of Epoxy matrix composites is investigated by impact machine. Four different types of reinforcement are used in the experimental works: type one: 1.9wt% steel fiber, 1.9wt% carbon fiber,1.9 wt% carbon nanotube, 1.9 wt% woven carbon fiber.This work shows that reinforcing epoxy with (1.9 wt% of woven carbon fiber) improves the impact properties where energy, force and deformation values of impact test for this composite were 18.4J, 3580.59 N and 18 mm respectively while for epoxy were 2.927 J, 921.849 N and 18.413 mm respectively.

Surface discharge measurements of polymeric materials

2003 ◽  
Vol 150 (2) ◽  
pp. 43-52 ◽  
Author(s):  
Y.L. Sam ◽  
S.G. Swingler ◽  
S.J. Sutton ◽  
J.S. Wilkinson ◽  
P.L. Lewin ◽  
...  
Keyword(s):  
Polymeric Materials ◽  
Surface Discharge ◽  
Discharge Measurements

FORMATION OF COMBINED SURFACE FEATURES OF PROTRUSION ARRAY AND WRINKLES ATOP SHAPE-MEMORY POLYMER

2009 ◽  
Vol 16 (06) ◽  
pp. 929-933 ◽  
Author(s):  
L. SUN ◽  
Y. ZHAO ◽  
W. M. HUANG ◽  
T. H. TONG
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Polymer Surface ◽  
Cost Effective ◽  
Gold Layer ◽  
Surface Features ◽  
Cost Effective Approach ◽  
Different Types ◽  
Sputter Deposited ◽  
Steel Balls

We demonstrate a simple and cost-effective approach to realize two combined surface features of different scales together, namely submillimeter-sized protrusion array and microwrinkles, atop a polystyrene shape-memory polymer. Two different types of protrusions, namely flat-top protrusion and crown-shaped protrusion, were studied. The array of protrusions was produced by the Indentation-Polishing-Heating (IPH) process. Compactly packed steel balls were used for making array of indents. A thin gold layer was sputter deposited atop the polymer surface right after polishing. After heating for shape recovery, array of protrusions with wrinkles on the top due to the buckling of gold layer was produced.

Location Depending Textures of the Human Dental Enamel

2010 ◽  
Vol 160 ◽  
pp. 281-286 ◽  
Author(s):  
Lars Raue ◽  
Helmut Klein
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Dental Enamel ◽  
Polymeric Materials ◽  
Incisor Tooth ◽  
Worst Case ◽  
Dental Fillings ◽  
Anisotropic Mechanical Properties ◽  
Different Types ◽  
Materials Used

Dental enamel is the most highly mineralised and hardest biological tissue in human body [1]. Dental enamel is made of hydroxylapatite (HAP) - Ca5(PO4)3(OH), which is hexagonal (6/m). The lattice parameters are a = b = 0.9418 nm und c = 0.6875 nm [1]. Although HAP is a very hard mineral, it can be dissolved easily in a process which is known as enamel demineralization by lactic acid produced by bacteria. Also the direct consumption of acid (e.g. citric, lactic or phosphoric acid in soft drinks) can harm the dental enamel in a similar way. These processes can damage the dental enamel. It will be dissolved completely and a cavity occurs. The cavity must then be cleaned and filled. It exists a lot of dental fillings, like gold, amalgam, ceramics or polymeric materials. After filling other dangers can occur: The mechanical properties of the materials used to fill cavities can differ strongly from the ones of the dental enamel itself. In the worst case, the filling of a tooth can damage the enamel of the opposite tooth by chewing if the interaction of enamel and filling is not equivalent, so that the harder fillings can abrade the softer enamel of the healthy tooth at the opposite side. This could be avoided if the anisotropic mechanical properties of dental enamel would be known in detail, hence then another filling could be searched or fabricated as an equivalent opponent for the dental enamel with equal properties. To find such a material, one has to characterise the properties of dental enamel first in detail for the different types of teeth (incisor, canine, premolar and molar). This is here exemplary done for a human incisor tooth by texture analysis with the program MAUD from 2D synchrotron transmission images [2,3,4].

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