1,732,503 research outputs found
Measurement of surface potential decay of corona-charged polymer films using the pulsed electroacoustic method
No full textIn this paper, the pulsed electroacoustic (PEA) technique that allows the determination of space charge in a dielectric material has been used to monitor the electrical potential decay of corona-charged polyethylene films of different thicknesses. To prevent possible disturbance on the surface charge during the PEA measurements, two thin polyethylene films were placed on both sides of the corona-charged sample. Charge profiles measured at different times were used to calculate the potential across the sample. The obtained potential decay was compared with the potential measured using the conventional method. A good agreement has been obtained. More importantly, the charge profile obtained using the PEA technique indicates that bipolar charge injection has taken place
Generalized Partial-Slice Monogenic Functions: A Synthesis of Two Function Theories
No full textIn this paper, we review the notion of generalized partial-slice monogenic functions that was introduced by the authors in Xu and Sabadini (Generalized partial-slice monogenic functions, arXiv:2309.03698, 2023). The class of these functions includes both the theory of monogenic functions and of slice monogenic functions over Clifford algebras and it is obtained via a synthesis operator which combines a generalized Cauchy-Riemann operator with an operator acting on slices. Besides recalling the fundamental features, we provide a notion of *\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document}-product based on the CK-extension and discuss the smoothness of generalized partial-slice functions
Space Charge Behaviour at LDPE Interface under AC Electric Stress
No full textThis paper reports on measurements of space charge characteristics in single and two-layer of low-density polyethylene (LDPE) films subjected to an applied voltage with a range of frequencies from dc to 50 Hz. Space charge was measured using the pulsed electroacoustic (PEA) technique. To measure charge distributions under ac electric fields at different angles, the point-on-wave method has been used. To obtain a good signal to noise ratio under ac conditions, the measured signals were averaged between 1000 and 2000 times. Experimental results demonstrated that frequency is a significant factor that affects bulk charge formation/distribution. In addition, interfacial charge between polymer and polymer in the two-layer arrangement was influenced by the type of electrode material
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An improved pulsed electroacoustic system for space charge measurement under AC conditions
Full text linkIn this paper, an improved space charge measurement system based on the pulsed electro acoustic technique (PEA) is presented. The new system gives an essential way to examine the role of space charge in electrical aging process under AC conditions. The system setup for AC measurement is presented and detailed in this paper with comparison to the old system. There are two features with improved PEA system. A pulse generator with a 3 kHz repetition rate is utilized to reduce the measurement time. The Eclipse data acquisition system is used to achieve the high data acquisition rate. The results which were taken from both old and new PEA system show that heterocharge can be formed in the region close to the lower electrode under AC electric field. Apparently the results captured from the new system have better phase resolution than the old system. The space charge decay profile measured by the new system can reflect vividly on the charge dynamically changing. The utmost space charge information was saved as the measurement time was dramatically shortened by the improved system
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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