Electrical Aging Tests on Enameled Wire Exposed to Gamma Irradiation

Microscopic and nanoscopic EVA composite investigation: Electrical properties and effect of purification treatment

This work presents preliminary results of an investigation aiming at characterization of nanocomposite insulating materials. Focus is made on size and technological process effects, i.e. dependence of electrical properties on filler size, on polymer-nanofiller interaction (e.g. intercalation or exfoliation) and, in particular, on chemical purification procedures. The materials under investigation are (EVA) copolymer filled by layered micro and nanosized silicates consisting of montmorillonite and fluorohectorite, that is, natural and synthetic clays. Microstructural characterization, using transmission electron microscopy, TEM, and wide-angle X-ray spectroscopy, WAXS, and electrical measure…

Electric strength, space charge and surface discharge characterization of nanostructured epoxy-silicate insulating materials

A set of surface discharge ageing procedures, space charge observations and dielectric strength measurements has been implemented on a type of insulating nanofilled epoxy-resin (nanostructured by compatibilised synthetic layered silicates) and on its non-filled base resin. Promising improvements in the electrical behaviour of the nanofilled epoxy, particularly as concerns surface discharge endurance, were detected. Regarding space charge, it was found that its accumulation rate as a function of ageing time is lower for the nanostructured resin. Finally, the nanofilled material evidenced a highly homogeneous behaviour of the dielectric strength data distribution.

Metastatic hepatocellular carcinoma of the parotid region without lung metastasis: a case report

Parotid gland metastatic tumours are rare, usually arising from a primary mucosal or cutaneous cancer located in the ipsilateral head and neck region, although metastases from a primary cancer outside the head and neck region are possible. Hepatocellular carcinoma (HCC) rarely metastasizes to the head and neck region and the parotid glands are an even more unusual site. The authors describe the case of an 82-year-old male who presented with a right parotid mass. Percutaneous incisional biopsy with histological and immunohistochemical studies suggested metastatic HCC. Radiological investigations excluded other metastatic lesions. This case illustrates the difficulties that may be encountered…