Space charge behavior of XLPE/silica nanocomposites under high electric field
Space charge formation behavior is compared among crosslinked polyethylene and its two nanocomposites with silica nanofillers with and without surface treatment. By conducting a degassing treatment, we have prepared nine kinds of samples in total. As a result, it was found that the presence of cross-linking by-products suppresses space charge formation. As far as the present silica nanofillers are concerned, their addition to XLPE enhances the formation of negative space charge near the cathode.
The effects of material properties and inclusions on the space charge profiles of LDPE and XLPE
The effects of material properties and inclusions on the space charge profiles in LDPE and XLPE were examined. Whereas the charge profile in LDPE is influenced by material properties such as the degree of crystallinity and MFR, the charge profile in XLPE is influenced by inclusions in the material such as acetophenone, moisture and various kinds of phenolic antioxidant. In order to examine the effect of moisture on the creation of negative hetero-charge in XLPE, the charge profiles in LDPE and XLPE containing a non-ionic surfactant glycerol monostearate were examined. Taking into account the density of the hetero-charge in relation to the concentration of cross-linking byproducts, as well as the conductivity of pure water containing each of the cross-linking byproducts, the mechanism of hetero-charge creation in XLPE was discussed.
The Categorical Stability of Gambling Motives Among Community-Recruited Gamblers: A Longitudinal Assessment
Over the past decade, several motivational models have been proposed to explain the role of motives in gambling disorder. In the model captured by the four-factor Gambling Motives Questionnaire Financial (GMQ-F), gamblers are described as being primarily motivated to gamble for ‘coping’, ‘enhancement’, ‘social’, and ‘financial’ reasons. Although this model has received significant empirical support; to date, research assessing the role of motives in gambling disorder has been primarily cross-sectional in nature. Thus, the extent to which gambling motives remain stable over time has yet to be explored. In the current study, the stability versus fluidity of self-assessed gambling motives was investigated using the Quinte Longitudinal Study, a longitudinal dataset of gambling behaviour collected over 5 years. Gambling motives of 2795 gamblers were examined over all five annual assessments. The total proportion of gamblers who stayed in the same primary motive category across each of the 5 consecutive assessments was 22%, indicating substantial fluidity in category membership. Substantial movement between categories was seen for each GMQ-F group, as well as an additional group of non-classified motives. Logistic regression analyses suggest that greater resistance to gambling fallacies significantly predicted stability between the baseline assessment and a follow-up 1 year later, but gambling severity did not. Potential limitations in the study design and opportunities for future research are discussed.