Search results for " phenomenon"
showing 10 items of 109 documents
Extensions and corona decompositions of low-dimensional intrinsic Lipschitz graphs in Heisenberg groups
2020
This note concerns low-dimensional intrinsic Lipschitz graphs, in the sense of Franchi, Serapioni, and Serra Cassano, in the Heisenberg group $\mathbb{H}^n$, $n\in \mathbb{N}$. For $1\leq k\leq n$, we show that every intrinsic $L$-Lipschitz graph over a subset of a $k$-dimensional horizontal subgroup $\mathbb{V}$ of $\mathbb{H}^n$ can be extended to an intrinsic $L'$-Lipschitz graph over the entire subgroup $\mathbb{V}$, where $L'$ depends only on $L$, $k$, and $n$. We further prove that $1$-dimensional intrinsic $1$-Lipschitz graphs in $\mathbb{H}^n$, $n\in \mathbb{N}$, admit corona decompositions by intrinsic Lipschitz graphs with smaller Lipschitz constants. This complements results that…
Pulsed Electro-Acoustic Method for specimens and cables employed in HVDC systems: Some feasibility considerations
2018
Recent experiments on the use of the PEA method for testing dielectric materials in specimens and comparison with a detailed model provide an insight of the phenomenon and suggest the need of adopting similar models also for cables. What is said is even more important considering the possible future adoption of the PEA methodology to test DC cables for Pre-Qualification and Type Tests. The use of an accurate model of the PEA cell used for testing specimens and related experiments prove that the thickness of the different parts composing the PEA setup is a basic element for providing accurate charge reading and interpretation of the phenomenon. Both simulation and experimental results, carri…
The Acoustic Wave Behavior Within the PEA Cell for Space Charge Measurement
2018
In order to evaluate the acoustic wave behavior within the Pulsed Electro Acoustic (PEA) cell, a simulation model has been developed in this work. The model, implemented in Matlab environment, is based on the analogy between acoustic and electrical quantities. Therefore, it was possible to model the PEA cell as cascade connected lossy transmission lines. The model has been validated theoretically by making a comparison with a simulation result found in literature. The experimental validation has also been made by using the PEA cell of the LEPRE high voltage lab. In addition, four graphs have been realized. Two of them can be used to establish in easy and fast way to obtain the minimum groun…
Acoustic Wave Behavior in a Specimen Containing an Air Void Defect
2019
The PEA method is the most used technique for the space charge measurements. As is well known, this method uses pressure waves to detect the charges accumulated in solid dielectrics. Based on its working principle, the generated acoustic waves travel within PEA cell and the specimen under test in order to be finally detected by the piezoelectric sensor. For a multilayer specimen and, in particular, in case of different materials that make up the specimen, the acoustic wave reflection is inevitable. Considering that, in several cases, the reflected waves could be detected by the piezoelectric sensor before than the main signals, the PEA cell output profile could results distorted. Based on t…
Impact of accumulated dust particles' charge on the photovoltaic module performance
2016
Abstract This work is focused on analysing effect of accumulated dust particles' charge on PV module performance. In the Dundee University's laboratory, dust particles have been created through epoxy powder and charged by using corona and tribo-electric charging methods by varying the charge levels of the accumulated dust particles. The PV module output has analysed for finding a relation between charge levels of the accumulated dust particles and its output voltage. Obtained experimental results have shown that charge level of accumulated dust particles on PV module's have significant impact on its output and dust particle accumulations are not associated with panel tilt angle.
Recent advances of the multipactor RF breakdown in RF satellite microwave passive devices
2016
The main goal of this work is the review of the recent advances in the study of the multipactor RF breakdown phenomenon in RF satellite microwave passive devices for space telecommunication applications developed in the Val Space Consortium. In this work several topics related with the multipactor phenomenon will be discussed.
Does Linguistic Analysis Confirm the Validity of Facilitated Communication?
2016
Facilitated communication (FC) has been interpreted as an ideomotor phenomenon, in which one person physically supports another person’s hand and unconsciously affects the content of the writing. Despite the strong experimental evidence against the authenticity of FC output, several studies claim to support its validity based on idiosyncrasies found in the texts produced. A review of these studies showed that, because of the logical circularity of the reasoning proposed in the studies, no decisive evidence that validated FC was presented. In addition, the idiosyncrasies found were better explained as by-products of the unusual writing process itself. Finally, the studies did not fulfill th…
Bodies Making Spaces: Understanding the Airport as a Site of Dissonance
2019
AbstractTrakilović theorizes the airport as a site where cultural/European notions of belonging are negotiated and controlled. Focusing on Schiphol airport in Amsterdam, the chapter approaches both the airport itself as well as its nearby detention center as one complex cultural phenomenon, from which Schiphol emerges as a site of heritage dissonance. Taking a phenomenological approach, the chapter explores what it means to be an embodied subject at the airport, taking the narrative of a Syrian newcomer who is relocated to the detention center as well as the author’s own experience of the airport as its analytical starting points. The selective processes of in- and exclusion at the airport …
Differences and similaritites between corporate governance principles in Islamic banks and Conventional banks
2017
Abstract The purpose of this paper is to present the some differences and similarities between corporate governance principles in Islamic banks and conventional banks by paradigmatic diversification. Since Corporate governance in Islamic banks is a social phenomenon in Islamic societies, the paper uses social theory paradigms (functionalist, interpretive, radical humanist and radical structuralist) to compare between corporate governance in Islamic banks and conventional banks. This paper demonstrates that mainstream corporate corporate governance theories are not a law of nature but a social construct.
Book Clubs and Book Commerce
2019
In the twentieth century, cumulative millions of readers received books by mail from clubs like the Book-of-the-Month Club, the Book Society or Bertelsmann Club. This Element offers an introduction to book clubs as a distribution channel and cultural phenomenon, and shows that book clubs and book commerce are linked inextricably. It argues that a global perspective is necessary to understand the cultural and economic impact of book clubs in the twentieth and into the twenty-first century. It also explores central reasons for book club membership, condensing them into four succinct categories: convenience, community, concession and, most importantly, curation. This title is also available as…