Life estimation and investigation of dielectric strength of multistressed high-voltage epoxy micro and nanocomposites

Micro & nano letters

article

Muhammad Amin¹  Abraiz Khattak¹  Muhammad Ali³ 

[1] Department of Electrical Engineering, COMSATS Institute of Information Technology (CIIT);Department of Electrical Engineering, City University of Science and IT (CUSIT);Department of Electrical Engineering, University of Engineering and Technology (UET)

关键词: filled polymers;    nanocomposites;    electric strength;    nanofabrication;    silicon compounds;    leakage currents;    regression analysis;    dielectric strength;    multistressed high-voltage epoxy microcomposites;    multistressed high-voltage epoxy nanocomposites;    life estimation;    epoxy-silica nanocomposites;    epoxy-silica microcomposites;    multiple accelerated stresses;    neat epoxy;    weather epoxy;    ASTM-D149;    ageing;    leakage current;    regression technique;    time 9000 h;    time 1000 h;    SiO2;   

DOI  :  10.1049/mnl.2016.0343

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Objective: Arterial oxygen pressure (PaO2) may decrease at induced hypotension during general anesthesia by nicardipine or prostaglandin E1 (PG). The present study was performed to compare the effects of nicardipine and PG on PaO2 during induced hypotension in general anesthesia.Methodology: This randomized controlled non-blind study was conducted at our operating room at the University Hospital. Fifty patients aged 40 to 65 years for resection of brain tumor were enrolled in the study. During general anesthesia with isoflurane, nitrous oxide and fentanyl, when hemodynamics were stable, PG 0.05 µg/kg/min, or 0.1 µg/kg/min, or nicardipine 0.5 µg/kg/min, or 1.0 µg/kg/min was administered for two hours in 10 patients each. Another 10 patients were reserved as the control. Arterial blood pressure, heart rate, percutaneous oxygen saturation (SpO2), end-tidal carbon dioxide pressure (EtCO2), and arterial oxygen (PaO2) and carbon dioxide (PaCO2) pressures were measured until 90 min after stop of administration of PG or nicardipine. Ratio of PaO2 and oxygen fraction (P/F ratio) was calculated.Results: Both PG and nicardipine decreased blood pressure similarly with increase in heart rate. P/F ratio decreased only with PG.Conclusion. The use of prostaglandin E1 to induce hypotension during general anesthesia is associated with a decreased PaO2, while nicardipine has no effect. This difference in effect on PaO2 is important in selecting an agent to induce hypotension in neurosurgery.

【 授权许可】

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