The coefficient of restitution of different representative types of granules

Gas fluidised beds have many applications in a wide range of industrial sectors and it is important to be able to predict their performance. This requires, for example, a deeper appreciation of the flow of the particles in such systems using both empirical and numerical methods. The coefficient of restitution is an important collisional parameter that is used in some granular flow models in order to predict the velocities and positions of the particles in fluidised beds. The current paper reports experimental data involving the coefficients of restitution of three different representative types of granule viz. melt, wet and binderless granules. They were measured at various impact velocities and the values were compared with those calculated from different theoretical models based on quasi-static contact mechanics. This required knowledge of the Young's moduli and yield stresses, which were measured quasi-statically using diametric compression. The results show that the current theoretical models for the coefficient of restitution explored here lead to either an over- or an under-estimation of the measured values. The melt granules exhibited the greatest values of the coefficient of restitution, Young's modulus and yield stress. The differences in these values were consistent with the nature of the interparticle bonding for each of the three granule types. A new model for the calculation of the coefficient of restitution of granular material was developed that takes account of the work hardening of the granules during impact. Generally, this model provides an improved prediction of the measured values. (c) 2006 Elsevier Ltd. All rights reserved.

Calculation of loss in conductors of a superconducting shielded slotted line and a coplanar waveguide

Finite conductivity in superconductors is taken into account by approximate boundary conditions imposed directly when deriving pair summatory equations, which are solved using the Galerkin method and the basis describing the edge singularity.

Understanding Racial Tensions in Northern Ireland: Threat, Paranoia and the Fear of Loss

This paper will explore the development of increased group tensions in Northern Ireland <br/>over the past decade with a special emphasis being placed upon rising racial tensions in cities such <br/>as Belfast and Lisburn. The paper will analyse why Northern Ireland has been described as the new <br/>race-hate capital of Europe and, through a case-study of Loyalism, will argue that if this growth in <br/>racist sentiment is to be prevented, more needs to be done to understand the causes of such feeling, <br/>particularly within loyalist working-class areas. I will argue that society as a whole needs to address <br/>the fears and anxieties of those that perceive themselves to be under threat from the recent increase <br/>in immigration or else we risk creating a new cause célèbre for those that would seek to extend the <br/>lifetime of our paramilitary organisations. Moreover, at a time when loyalist communities feel politically <br/>alienated and lacking representation, there is a real danger of British far-right groups exploiting the <br/>situation and making long-term political capital.

Forced Displacement, Suffering and the Aesthetics of Loss

This article investigates how artists have addressed shocking experiences of displacement in different political contexts. Drawing on the notion of ‘the aesthetics of loss’ (Köstlin, 2010), it examines and compares the different aims, desires and strategies that have shaped the histories and social lives of paintings, memorial statues, installations and other artefacts. The analysis identifies a mode of artistic engagement with the sense of a ‘loss of homeland’ that has been commonly felt amongst Sudeten German expellees, namely the production and framing of visual images as markers of collective trauma. These aesthetics of loss are contrasted with the approach taken by the Dutch artist Sophie Ernst in her project entitled HOME. Working with displaced people from Pakistan, India, Palestine, Israel and Iraq, she created a mnemonic space to stimulate a more individualistic, exploratory engagement with the loss of home, which aimed, in part, to elicit interpersonal empathy. To simply oppose these two modes of aesthetic engagement, however, would ignore the ways in which artefacts are drawn into different discursive, affective and spatial formations. This article argues for the need to expose such dynamic processes of framing and reframing by focusing on the processual aspects of aestheticisation with attention to the perspective of loss.

Absorption coefficient of particulate matter on the south-west coast of Europe: a contribution to the validation of the MERIS-Medium Resolution Imaging Spectrometer sensor

Dissolved oxygen (DO) is one of the most important environmental variables of water quality, especially for marine life. Consequently, oxygen is one of the Chemical Quality Elements required for the implementation of European Union Water Framework Directive. This study uses the example of the Ria Formosa, a meso-tidal lagoon on the south coast of Portugal to demonstrate how monitoring of water quality for coastal waters must be well designed to identify symptoms of episodic hypoxia. New data from the western end of the Ria Formosa were compared to values in a database of historical data and in the published literature to identify long-term trends. The dissolved oxygen concentration values in the database and in the literature were generally higher than those found in this study, where episodic hypoxia was observed during the summer. Analysis of the database showed that the discrepancy was probably related with the time and the sites where the samples had been collected, rather than a long-term trend. The most problematic situations were within the inner lagoon near the city of Faro, where episodic hypoxia (<2 mg dm3 DO) occurred regularly in the early morning. These results emphasise the need for a balanced sampling strategy for oxygen monitoring which includes all periods of the day and night, as well as a representative range of sites throughout the lagoon. Such a strategy would provide adequate data to apply management measures to reduce the risk of more persistent hypoxia that would impact on the ecological, important natural resource. economic and leisure uses of this important natural resource.

Ruin Theory with Excess of Loss Reinsurance and Reinstatements

The present paper studies the probability of ruin of an insurer, if excess of loss reinsurance with reinstatements is applied. In the setting of the classical Cramer-Lundberg risk model, piecewise deterministic Markov processes are used to describe the free surplus process in this more general situation. It is shown that the finite-time ruin probability is both the solution of a partial integro-differential equation and the fixed point of a contractive integral operator. We exploit the latter representation to develop and implement a recursive algorithm for numerical approximation of the ruin probability that involves high-dimensional integration. Furthermore we study the behavior of the finite-time ruin probability under various levels of initial surplus and security loadings and compare the efficiency of the numerical algorithm with the computational alternative of stochastic simulation of the risk process. (C) 2011 Elsevier Inc. All rights reserved.

Report of Loss in Capacity Due to Ice at Rankine Station - April 1934 through April 1937

A report compiled by Canadian Niagara Power Company describes the loss in capacity due to ice. The chart reveals the kilowatts lost and the duration of the outage and the "min. forebay elevation during ice loss period".

A Survey Measure of Risk Aversion

We Use Survey Data on the Well-Being of Individuals to Measure Attitude Toward Risk. Risk Neutrality Cannot Be Rejected by the Data.

Salting coefficient of hydroxybenzoic acids

The Setschenow parameter and thermodynamic parameters of transfer of 2- and 4- hydroxybenzoic acids from water to salt solutions have been reported. The data have been rationalised by considering the structure breaking effects of the ions of the salts, the localized hydrolysis model, the internal pressure theory and the theory of water structure due to Symons.

Estimating the reliability coefficient of tests in presence of missing values

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Part load operation coefficient of air-conditioning system of public building

IPLV overall coefficient, presented by Air-Conditioning and Refrigeration Institute (ARI) of America, shows running/operation status of air-conditioning system host only. For overall operation coefficient, logical solution has not been developed, to reflect the whole air-conditioning system under part load. In this research undertaking, the running time proportions of air-conditioning systems under part load have been obtained through analysis on energy consumption data during practical operation in all public buildings in Chongqing. This was achieved by using analysis methods, based on the statistical energy consumption data distribution of public buildings month-by-month. Comparing with the weight number of IPLV, part load operation coefficient of air-conditioning system, based on this research, does not only show the status of system refrigerating host, but also reflects and calculate energy efficiency of the whole air-conditioning system. The coefficient results from the processing and analyzing of practical running data, shows the practical running status of area and building type (actual and objective) – not clear. The method is different from model analysis which gets IPLV weight number, in the sense that this method of coefficient results in both four equal proportions and also part load operation coefficient of air-conditioning system under any load rate as necessary.