Multiculturalism: Questions, Not Answers.

A reply by Richard B. Stuart regarding the comment by Stolle, Hutz, and Sommers-Flanagan (see record 2005-13212-019). The American Psychological Association (APA) guidelines on multiculturalism (APA, 2002b) exhort psychologists to recognize and control their personal biases and to strive to "apply culturally appropriate skills in clinical and other applied psychological practices" (p. 3). My article (see record 2004-10365-001) offered 12 suggestions aimed at helping psychologists follow these mandates. It was motivated by the fear that some well-intended attempts to appreciate diversity could inadvertently contribute to the very insensitivity they were intended to prevent. It is my view that group influences are extremely important in shaping individual identity, but the effect of culture on a given individual cannot be verified without consulting that person directly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of a gap between dielectric and waveguide on the dispersion relation of the ?erenkov device

We present a method for calculating efficiently the dispersion curve of a cylindrical ?erenkov device having a small gap between the dielectric liner and the guide wall. In any practical realisation, such a gap cannot be avoided and the results obtained here indicate that the dispersion curve is very sensitive to its thickness. Using a liner with a higher dielectric constant increases the sensitivity of the dispersion to the size of the gap. If a very high-energy electron beam is employed, having an electron velocity almost equal to c (speed of light in a free space) then synchronism occurs close to the intersection of the dispersion curve and the vacuum light line where the effect of the gap is small; in fact, a large gap could be left between the dielectric liner and the waveguide if this was advantageous for construction purposes. However, at lower electron energies, typical of those used in microwave devices, the effect of even a relatively small gap can be considerable on the synchronism condition.     

The Bidirectional Mapping Problem

Mappings between models and languages are essential to support model driven approaches to software development. Those mappings need to be supported by tools. There are different kinds of mapping appropriate for different stages in the development process. This paper focuses on bidirectional mappings between models used to capture software requirements and models used to capture software designs. The properties of such mappings are illustrated using a mapping between models used in the development of web-based, business systems. This motivates and helps identify a set of benchmarks against which approaches to the definition and tooling of such mappings can be judged. The paper concludes with pointers to one approach at addressing the bidirectional mapping problem.     

A quantitative risk assessment of a domestic property connected to a hydrogen distribution network

The increased reliance on natural gas for heating worldwide makes the search for carbon-free alternatives imperative, especially if international decarbonisation targets are to be met. Hydrogen does not release carbon dioxide (CO₂) at the point of use which makes it an appealing candidate to decarbonise domestic heating. Hydrogen can be produced from either 1) the electrolysis of water with no associated carbon emissions, or 2) from methane reformation (using steam) which produces CO₂, but which is easily captured and storable during production. Hydrogen could be transported to the end-user via gas distribution networks similar to, and adapted from, those in use today. This would reduce both installation costs and end-user disruption. However, before hydrogen can provide domestic heat, it is necessary to assess the ‘risk’ associated with its distribution in direct comparison to natural gas. Here we develop a comprehensive and multi-faceted quantitative risk assessment tool to assess the difference in ‘risk’ between current natural gas distribution networks, and the potential conversion to a hydrogen based system. The approach uses novel experimental and modelling work, scientific literature, and findings from historic large scale testing programmes. As a case study, the risk assessment tool is applied to the newly proposed H100 demonstration (100% hydrogen network) project. The assessment includes the comparative risk of gas releases both upstream and downstream of the domestic gas meter. This research finds that the risk associated with the proposed H100 network (based on its current design) is lower than that of the existing natural gas network by a factor 0.88.     

Comparison of the dynamic responses of monopiles and gravity base foundations for offshore wind turbines in sand using centrifuge modelling

Monopiles and gravity base foundations (GBF) are two of the most commonly used foundations for offshore wind turbines. As resonance can cause damage and even failure of wind turbines, understanding the difference between the dynamic responses of monopiles and GBFs under free vibration is important. However there is little experimental data regarding their natural frequency, especially from model tests carried out at correct stress levels. This paper presents the results of novel monopile and GBF tests using a centrifuge to directly determine the natural frequency (f_n) of the foundation-soil system. The natural frequencies of wind turbine monopiles and GBFs in centrifuge models were measured during harmonic loading using a piezo-actuator, with the results confirming that soil-structure interaction must be considered to obtain the system’s natural frequency as this frequency reduces substantially from fixed-base values. These results will contribute in preventing resonance induced damage in wind-turbines.     

Influence of Pluronic coating formulation on iron oxide nanoparticle transport in natural and oil-impacted sandy aquifer media

Targeted delivery of nanoparticles has the potential to enhance remediation and characterization of sites contaminated with non-aqueous phase liquids (NAPLs) by ensuring delivery of treatment or contrast agents to the NAPL/water interface. For a targeted delivery technique to be successful, nanoparticles must be capable of transporting through porous media and binding to NAPLs under relevant geological conditions. In this study, successful targeted delivery of nanoparticles to sandy aquifer material mixed with crude oil was achieved using an active targeting technique based on an amphiphilic polymer coating. It was determined that the molecular structure and concentration of the nanoparticle coating greatly influenced the recovery of nanoparticles injected into saturated columns. Coatings with longer polymer molecules and lower polymer concentrations reduced recovery, and the nanoparticle coating formulation could be adjusted to improve transport while maintaining targeted binding behaviour. This study demonstrated that nanoparticle retention in oil-impacted sand exceeded that of clean sand in flow through experiments, indicating that a nanoparticle targeted delivery strategy for soil contaminated with LNAPLs such as crude oil is possible under the experimental conditions explored.