Long term accelerated aging investigation of an epoxy/silica nanocomposite for high voltage insulation

AbstractAn epoxy/silica nanocomposite loading was subjected to a multistress environment along with neat epoxy (NEP) in a specially fabricated chamber at 2.5 kV for 9000 h. For aging investigation of the samples, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), leakage current monitoring and Swedish Transmission Research Institute hydrophobicity classification were used with constant visual inspection. Both samples were found to be adequate and suitable for insulation at the end of the aging period. However, the epoxy nanocomposite (EPNC) performed better in comparison to NEP. FTIR spectrographs showed that a reduction in important hydrocarbon groups was less in the EPNC. The leakage current was higher in the case of the neat sample and accompanied by a higher loss of hydrophobicity. Similarly, in the nanocomposite, no significant change in surface topography at micro level was recorded from the SEM analysis.

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Influence of Overgrown Micropipes in the Active Area of SiC Schottky Diodes on Long Term Reliability

Materials Science Forum ◽

10.4028/www.scientific.net/msf.483-485.925 ◽

2005 ◽

Vol 483-485 ◽

pp. 925-928 ◽

Cited By ~ 10

Author(s):

Roland Rupp ◽

Michael Treu ◽

Peter Türkes ◽

H. Beermann ◽

Thomas Scherg ◽

...

Keyword(s):

Leakage Current ◽

Power Dissipation ◽

Schottky Diodes ◽

Physical Structure ◽

Active Area ◽

Clear Correlation ◽

Local Power ◽

Degradation Mechanisms ◽

Failure Simulation

Other than open micropipes (MP), overgrown micropipes do not necessarily lead to a^significantly reduced blocking capability of the affected SiC device. However they can lead to a degradation of the device during operation. In this paper the physical structure of overgrown micropipes will be revealed and their contribution to the leakage current will be shown. The possible impact of the high local power dissipation in the surrounding of the overgrown micropipe will be discussed and long term degradation mechanisms will be described. Failure simulation under laboratory conditions shows a clear correlation between the position of overgrown micropipes and the location of destructive burnt spots.

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Effects of Accelerated Aging Period of Time at 180°C on Tensile Property of Plain Woven Fabric/Epoxy Resin Laminated Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.182-183.76 ◽

2012 ◽

Vol 182-183 ◽

pp. 76-79 ◽

Cited By ~ 1

Author(s):

Lei Lei Song ◽

Quan Rong Liu ◽

Jia Lu Li

Keyword(s):

Tensile Strength ◽

Carbon Fiber ◽

Epoxy Resin ◽

Laminated Composites ◽

Accelerated Aging ◽

Woven Fabric ◽

Accelerated Ageing ◽

Time Intervals ◽

Composite Samples

In this paper, carbon fiber reinforced resin matrix composites were produced by stacking eight pieces of carbon fiber woven plain fabric and subjected to accelerated ageing. Accelerated ageing was carried out in oven at 180°C for three different time intervals (60 hours, 120 hours and 180 hours). The influence of different ageing time intervals at 180°C on tensile properties of laminated composites was examined, compared with the composites without aging. The appearance and damage forms of these laminated composites were investigated. The results revealed that the tensile strength of the laminates declined significantly after long term accelerated aging at 180°C. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 180°C are 80.36%, 79.82%, 76.57% of average tensile strength of composite samples without aging, respectively. The high temperature accelerated aging makes the resin macromolecular structure in the composites changed, and then the adhesive force between fiber bundles and resin declines rapidly which result in the tensile strength of composites aged decrease. This research provides a useful reference for long term durability of laminated/epoxy resin composites.

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Biocompatibility Evaluation of Hollow Pollen Grains/Fe3 O4 Nanoparticles Composites as Potential Medical Devices

International Journal of Nanoscience ◽

10.1142/s0219581x21500484 ◽

2021 ◽

Author(s):

Solmaz Zakhireh ◽

Yadollah Omidi ◽

Younes Beygi-Khosrowshahi ◽

Ayoub Aghanejad ◽

Jaleh Barar ◽

...

Keyword(s):

Morphological Analysis ◽

Pollen Grains ◽

Building Blocks ◽

Drug Carriers ◽

Sem Analysis ◽

Narrow Region ◽

In Vitro Biocompatibility ◽

Apoptosis Related Gene

Recently, pollen grains (PGs) have been introduced as drug carriers and scaffolding building blocks. This study aimed to assess the in-vitro biocompatibility of Pistacia vera L. hollow PGs/Fe3O4 nanoparticles (HPGs/Fe3O4NPs) composites using human adipose-derived mesenchymal stem cells (hAD-MSCs). In this regard, iron oxide nanoparticles (Fe3O4NPs) were assembled on the surface of HPGs at different concentrations. The biocompatibility of the prepared composites was assessed through MTT assay, apoptosis-related gene expression and field emission scanning electron microscopy (FE-SEM) analysis. Compared to the bare HPGs, the HPGs/Fe3O4NPs exhibited a biphasic impact on hAD-MSCs. The composite containing 1% Fe3O4NPs demonstrated no cytotoxicity up to 21 days while higher Fe3O4NPs contents and long-term exposure revealed adverse effects on the hAD-MSCs’ growth. The obtained result was verified by the qRT-PCR and morphological analysis carried out through FE-SEM which suggests that a narrow region below 1% Fe3O4NPs may be the optimum choice for medicinal applications of HPGs/Fe3O4NPs microdevices.

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Characteristics of C4F7N/Epoxy Resin Insulation System Affected by Long-Term Electro-Thermal Accelerated Aging

IEEE Transactions on Dielectrics and Electrical Insulation ◽

10.1109/tdei.2021.009748 ◽

2021 ◽

Vol 28 (6) ◽

pp. 1973-1979

Author(s):

Cong Wang ◽

Renjie Cao ◽

Youping Tu ◽

Xin Ai ◽

Ying Zhang ◽

...

Keyword(s):

Epoxy Resin ◽

Accelerated Aging ◽

Insulation System

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Aging Studies of Pu-238 and -239 Containing Calcium Phosphate Ceramic Waste-forms

MRS Proceedings ◽

10.1557/opl.2013.926 ◽

2013 ◽

Vol 1518 ◽

pp. 73-78 ◽

Cited By ~ 1

Author(s):

Shirley K. Fong ◽

Brian L. Metcalfe ◽

Randall D. Scheele ◽

Denis M. Strachan

Keyword(s):

Calcium Phosphate ◽

Accelerated Aging ◽

Waste Form ◽

Calcium Phosphate Ceramic ◽

Ceramic Waste ◽

Waste Forms ◽

Aging Studies ◽

Flow Through ◽

Pyrochemical Reprocessing

ABSTRACTA calcium phosphate ceramic waste-form has been developed at AWE for the immobilisation of chloride containing wastes arising from the pyrochemical reprocessing of plutonium. In order to determine the long term durability of the waste-form, aging trials have been carried out at PNNL. Ceramics were prepared using Pu-239 and -238, these were characterised by PXRD at regular intervals and Single Pass Flow Through (SPFT) tests after approximately 5 yrs.While XRD indicated some loss of crystallinity in the Pu-238 samples after exposure to 2.8 x 1018 α decays, SPFT tests indicated that accelerated aging had not had a detrimental effect on the durability of Pu-238 samples compared to Pu-239 waste-forms.

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Development of a leakage current monitoring system of iced insulators base on fiber optic transmission

2009 IEEE 9th International Conference on the Properties and Applications of Dielectric Materials ◽

10.1109/icpadm.2009.5252445 ◽

2009 ◽

Cited By ~ 1

Author(s):

Yunpeng Liu ◽

Tao Yu ◽

Song Gao ◽

Jie Lu ◽

Shaohua You ◽

...

Keyword(s):

Monitoring System ◽

Leakage Current ◽

Fiber Optic ◽

Current Monitoring

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Sounds familiar(?): Expertise with specific musical genres modulates timing perception and micro-level synchronization to auditory stimuli

Attention Perception & Psychophysics ◽

10.3758/s13414-021-02393-z ◽

2021 ◽

Author(s):

Anne Danielsen ◽

Kristian Nymoen ◽

Martin Torvik Langerød ◽

Eirik Jacobsen ◽

Mats Johansson ◽

...

Keyword(s):

Skill Acquisition ◽

Hip Hop ◽

Musical Training ◽

Timing Perception ◽

Nature And Nurture ◽

Micro Level ◽

And Performance ◽

Musical Genres ◽

Perceptual Systems

AbstractMusical expertise improves the precision of timing perception and performance – but is this expertise generic, or is it tied to the specific style(s) and genre(s) of one’s musical training? We asked expert musicians from three musical genres (folk, jazz, and EDM/hip-hop) to align click tracks and tap in synchrony with genre-specific and genre-neutral sound stimuli to determine the perceptual center (“P-center”) and variability (“beat bin”) for each group of experts. We had three stimulus categories – Organic, Electronic, and Neutral sounds – each of which had a 2 × 2 design of the acoustic factors Attack (fast/slow) and Duration (short/long). We found significant effects of Genre expertise, and a significant interaction for both P-center and P-center variability: folk and jazz musicians synchronize to sounds typical of folk and jazz in a different manner than the EDM/hip-hop producers. The results show that expertise in a specific musical genre affects our low-level perceptions of sounds as well as their affordance(s) for joint action/synchronization. The study provides new insights into the effects of active long-term musical enculturation and skill acquisition on basic sensorimotor synchronization and timing perception, shedding light on the important question of how nature and nurture intersect in the development of our perceptual systems.

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Lalabet Financial Analysis: Study of Islamic Economics at Micro Level

Indonesian Interdisciplinary Journal of Sharia Economics (IIJSE) ◽

10.31538/iijse.v4i1.1506 ◽

2021 ◽

Vol 4 (1) ◽

pp. 233-244

Author(s):

Ainorrofiqie Ainorrofiqie ◽

Umrotul Khasanah ◽

Akhmad Djalaluddin

Keyword(s):

Financial Management ◽

Financial Analysis ◽

Financial Statements ◽

The Body ◽

Short Term ◽

The Family ◽

Micro Level ◽

The Impact ◽

The Village

This research aims to explore the model of financial management tradition Lalabet in the village of Babbalan District Batuan Sumenep. This study is based on the fact that occurred in the community about the implementation of traditions carried out by the heirs to family members who died. Interpretative qualitative research is used and an in-depth understanding of a problem that occurs is emphasized more. Based on the results of this study, the financial management tradition Lalabet can be done based on accounting equations. The accounts contained in the accounting equation is not used in its entirety and are reported as are generally financial statements. In this case, the source of funds in carrying out Lalabet tradition is sourced from personal money, money and donations from the family, money from Muslimat, debt, and money or goods from Lalabet's proceeds. The impact is the onset of debt both short-term and long-term. While the expenditure is in the form of costs in taking care of the body, costs for tahlilan (petto'arean), pa'polo, nyatos, nyataon, nyaebu, mangaji, ngin-tangin, nyalenin mayyid, and ajege makam (kep-sekep).

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