scholarly journals A Study on Long-time Electrical Treeing Deterioration Properties According to High Frequency Voltage of Epoxy Resin

2013 ◽  
Vol 62 (11) ◽  
pp. 1571-1577
Author(s):  
Jae-Jun Park
Keyword(s):  
Epoxy Resin ◽  
High Frequency ◽  
Long Time ◽  
Electrical Treeing

Comparison of wavelet continuous transform and signal averaged ECG for high frequency content and late potential detection in healthy individuals

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Garcia Iglesias ◽  
J.M Rubin Lopez ◽  
D Perez Diez ◽  
C Moris De La Tassa ◽  
F.J De Cos Juez ◽  
...  
Keyword(s):  
High Frequency ◽  
Classical Method ◽  
Total Power ◽  
Frequency Content ◽  
Healthy Individuals ◽  
Time Frequency ◽  
Qt Intervals ◽  
Long Time ◽  
Power Content ◽  
High Frequency Content

Abstract Introduction The Signal Averaged ECG (SAECG) is a classical method forSudden Cardiac Death (SCD) risk assessment, by means of Late Potentials (LP) in the filtered QRS (fQRS)[1]. But it is highly dependent on noise and require long time records, which make it tedious to use. Wavelet Continuous Transform (WCT) meanwhile is easier to use, and may let us to measure the High Frequency Content (HFC) of the QRS and QT intervals, which also correlates with the risk of SCD [2,3]. Whether the HFC of the QRS and QT measured with the WCT is a possible subrogate of LP, has never been demonstrated. Objective To demonstrate if there is any relationship between the HFC measured with the WCT and the LP analyzed with the SAECG. Methods Data from 50 consecutive healthy individuals. The standard ECG was digitally collected for 3 consecutive minutes. For the WCT Analysis 8 consecutive QT complexes were used and for the SAECG Analysis all available QRS were used. The time-frequency data of each QT complex were collected using the WCT as previously described [3] and the Total, QRS and QT power were obtained from each patient. For the SAECG, bipolar X, Y and Z leads were used with a bidirectional filter at 40 to 250 Hz [1]. LP were defined as less than 0.05 z in the terminal part of the filtered QRS and the duration (SAECG LP duration) and root mean square (SAECG LP Content) of this LP were calculated. Pearson's test was used to correlate the Power content with WCT analysis and the LP in the SAECG. Results There is a strong correlation between Total Power and the SAECG LP content (r=0.621, p<0.001). Both ST Power (r=0.567, p<0.001) and QRS Power (r=0.404, p=0.004) are related with the SAECG LP content. No correlation were found between the Power content (Total, QRS or ST Power) and the SAECG LP duration. Also no correlation was found between de SAECG LP content and duration. Conclusions Total, QRS and ST Power measured with the WCT are good surrogates of SAECG LP content. No correlation were found between WCT analysis and the SAECG LP duration. Also no correlation was found between the SAECG LP content and duration. This can be of high interest, since WCT is an easier technique, not needing long recordings and being less affected by noise. Funding Acknowledgement Type of funding source: None

scholarly journals The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin

2021 ◽  
Vol 129 ◽  
pp. 106838
Author(s):  
Siyuan Chen ◽  
Simon Rowland ◽  
James Carr ◽  
Malte Storm ◽  
Kwang-Leong Choy ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Particle Dispersion ◽  
Electrical Treeing

scholarly journals Preparation and properties of hybrid materials for high-rise constructions

2018 ◽  
Vol 33 ◽  
pp. 02075 ◽  
Author(s):  
Tatyana Matseevich
Keyword(s):  
Stress Relaxation ◽  
Epoxy Resin ◽  
Relaxation Process ◽  
Hybrid Materials ◽  
Mechanical Performance ◽  
Mechanical Relaxation ◽  
Physical Parameters ◽  
Quasi Equilibrium ◽  
High Rise ◽  
Long Time

The theme of the research is important because it allows to use hybrid materials as finishing in the high-rise constructions. The aim of the study was the development of producing coloured hybrid materials based on liquid glass, a polyisocyanate, epoxy resin and 2.4-toluylenediisocyanate. The detailed study of the process of stress relaxation at different temperatures in the range of 20-100°C was provided. The study found that the obtained materials are subject to the simplified technology. The materials easy to turn different colors, and dyes (e.g. Sudan blue G) are the catalysts for the curing process of the polymeric precursors. The materials have improved mechanical relaxation properties, possess different color and presentable, can be easily combined with inorganic base (concrete, metal). The limit of compressive strength varies from 32 to 17.5 MPa at a temperature of 20 to 100°C. The values σ∞ are from 20.4 to 7.7 MPa within the temperature range from 20 to 100°C. The physical parameters of materials were evaluated basing on the data of stress relaxation: the initial stress σ0, which occurs at the end of the deformation to a predetermined value; quasi-equilibrium stress σ∞, which persists for a long time relaxation process. Obtained master curves provide prediction relaxation behavior for large durations of relaxation. The study obtained new results. So, the addition of epoxy resin in the composition of the precursor improves the properties of hybrid materials. By the method of IR spectroscopy identified chemical transformations in the course of obtaining the hybrid material. Evaluated mechanical performance of these materials is long-time. Applied modern physically-based memory functions, which perfectly describe the stress relaxation process.

scholarly journals Clinic Case of Rare Type VI Osteogenesis Imperfecta

2019 ◽  
Vol 16 (1) ◽  
pp. 30-35
Author(s):  
Olga N. Ignatovich ◽  
Leyla S. Namazova-Baranova ◽  
Tea V. Margieva ◽  
Natalia V. Zhurkova ◽  
Kirill V. Savostyanov ◽  
...  
Keyword(s):  
Osteogenesis Imperfecta ◽  
High Frequency ◽  
Heterogeneous Group ◽  
Osteogenesis Imperfecta Type ◽  
Post Translational Modification ◽  
Rare Type ◽  
Genes Encoding ◽  
Long Time ◽  
Collagen Genes

Osteogenesis imperfect is genetically heterogeneous group of diseases which are characterized by bone brittleness and fractures. It was thought for a long time that this is happening due to mutations in collagen genes. However, within past decade the understanding of osteogenesis imperfecta etiology has changed as a result of genetics development. The majority of all cases is related to mutations in collagen genes whereas rare mostly recessive forms are related to mutations in genes encoding collagen post-translational modification. Mutations in SERPINF1 gene were chosen as molecular cause of osteogenesis imperfecta type VI in 2011. Thus the new pathophysiology of this disease was revealed. Children with osteogenesis imperfecta type VI have high-frequency of fractures despite the management with bisphosphonates because mineralized bone osteoid is considerably reduced.

Experimental study of low-temperature long-time relaxation in epoxy resin

1987 ◽  
Vol 68 (3-4) ◽  
pp. 285-299 ◽  
Author(s):  
M. Koláč ◽  
B. S. Neganov ◽  
A. Sahling ◽  
S. Sahling
Keyword(s):  
Experimental Study ◽  
Low Temperature ◽  
Epoxy Resin ◽  
Time Relaxation ◽  
Long Time

scholarly journals Effect of Air Gap on Electrical Tree in Epoxy Resin Under High Frequency Bipolar Square-Wave Voltage

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5722
Author(s):  
Shihang Wang ◽  
Chuang Zhang ◽  
Hang Fu ◽  
Jiao Xiang ◽  
Jianying Li ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
High Frequency ◽  
Air Gap ◽  
Heat Accumulation ◽  
Air Gaps ◽  
Square Wave ◽  
Electrical Tree ◽  
Electrical Trees ◽  
Voltage Frequency ◽  
Tree Characteristics

Insulation fails quickly under high-frequency AC high voltage, especially bipolar square-wave voltage with a high dV/dt. It is of great significance to study the failure mechanism of epoxy casting insulation under such kind of voltage. In this paper, pin-plane epoxy casting insulation samples with air gaps were prepared, and the relation between the electrical trees under the high frequency bipolar square-wave voltage and the air gap conditions and voltage frequencies (1~20 kHz) were studied. Results indicated that, with the presence of air gaps, the electrical trees were bush-type and had a relatively slow growth rate, which was different from the fast-growing branch-type trees in the samples without air gap. The electrical tree characteristics related with the size of air gap and voltage frequency were also studied. The electrical tree grew faster under higher voltage frequency or with a smaller air gap. Results proved that discharge introduced a lot of defects for the surface layer of the epoxy resin samples and hence induced the possibility of multi-directional expansion of electrical trees. In addition, the resulting heat accumulation and unique charge transport synergistically affected the electrical tree characteristics under the high frequency bipolar square-wave voltage.

scholarly journals Improved Clonal Selection Algorithm Based on Biological Forgetting Mechanism

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chao Yang ◽  
Bing-qiu Chen ◽  
Lin Jia ◽  
Hai-yang Wen
Keyword(s):  
High Frequency ◽  
Complexity Analysis ◽  
Clonal Selection ◽  
Optimal Solution ◽  
Antibody Concentration ◽  
Clonal Selection Algorithm ◽  
Selection Algorithm ◽  
Long Time ◽  
Optimization Efficiency ◽  
Candidate Set

The antibody candidate set generated by the clonal selection algorithm has only a small number of antibodies with high antigen affinity to obtain high-frequency mutations. Among other antibodies, some low-affinity antibodies are replaced by new antibodies to participate in the next clonal selection. A large number of antibodies with high affinity make it difficult to participate in clonal selection and exist in antibody concentration for a long time. This part of inactive antibody forms a “black hole” of the antibody set, which is difficult to remove and update in a timely manner, thus affecting the speed at which the algorithm approximates the optimal solution. Inspired by the mechanism of biological forgetting, an improved clonal selection algorithm is proposed to solve this problem. It aims to use the abstract mechanism of biological forgetting to eliminate antibodies that cannot actively participate in high-frequency mutations in the antibody candidate set and to improve the problem of insufficient diversity of antibodies in the clonal selection algorithm, which is prone to fall into the local optimal. Compared with the existing clonal selection and genetic algorithms, the experiment and time complexity analysis show that the algorithm has good optimization efficiency and stability.

Study on High-Speed Switch Shifting Solenoid Current Control Technology for Automatic Transmission

2014 ◽  
Vol 1006-1007 ◽  
pp. 639-642
Author(s):  
Chun Fu Li ◽  
Yan Qin Li
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Automatic Transmission ◽  
Current Control ◽  
Control Technology ◽  
Working Process ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Long Time ◽  
The Ideal

The purpose of the solenoid current control is to decrease holding current of the solenoid by selecting suitable frequency and duty, to keep the solenoid opening reliably for a long time and reduce power consumption and improve the solenoid close feature. In this paper, the high frequency signal in oil pressure holding process is determined by theoretical analysis and experimental study. The purpose of the study is to determine the ideal current in the working process of the solenoid.

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