Conservative permutation models of two-dimensional fluid flow : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Mathematics at Massey University

At a meeting of Massey University Mathematics Department staff and students on 20 March 1997, a project to model fluid flow by constructing successive permutations of lattice cells was discussed. Several assumptions about the fluid being modelled were necessary to make the problem manageable, the chief ones being that the fluid would be two dimensional, ideal and in-compressible. Two square lattice models were developed, one Eulerian and the other more Lagrangian, in which the lattice cells were each initially assigned a value of a vorticity function. The time evolution of these models consisted of finding a permutation of the cells that was "close" to the fluid flow, then permuting the fixed initial vorticity values according to this lattice map. Justification of this method followed from consequences of the assumptions, including advection of vorticities, and the invertibility and area-preserving nature of the fluid flow map. Reliance was placed on two previously published papers: one containing a result guaranteeing that such permutations are possible in certain circumstances, and the other providing the key to their practical construction. An essential algorithm in the latter paper relies on a theorem concerning the selection of a set of distinct elements from several sets. Also as a result of the assumptions, the enstrophy, total vorticity and kinetic energy of such hypothetical fluid flow is conserved, although tests neither conclusively confirmed nor denied all conserving properties of the models

Novel pulsed power applications.

Thesis (M.Sc.)-University of Natal, Durban, 2001.The purpose of this dissertation is to examine the mechanisms of the glow (Townsend) discharge, the arc (streamer) discharge, the corona discharge, and the vacuum discharge. The physics of each discharge is presented and then investigated by way of mathematical model and experiment. Four novel pulsed power experiments constructed for the purpose of examining each discharge are presented. Namely a transverse electric atmospheric carbon-dioxide laser, a flashlamp, a surface corona apparatus, and a plasma opening switch. Methods for the measurement of short duration intense electric and electromagnetic events are included. Practical aspects of pulsed power experimentation are discussed

Heading towards sustainability reporting: a pilot study into the progress of embracing the global reporting initiative in the United Kingdom

In the past decade much has been written on the need to develop social, ethical and environmentally responsible performance reporting frameworks that engage with all organisational stakeholders. The theoretical development of these frameworks has spanned nearly a century culminating in the release in 2000 of voluntary guidelines developed by the Coalition for Environmentally Responsible Economies and the United Nations Environment Programme through the offices of the Global Reporting Initiative (GRI). The release of the sustainability reporting guidelines perhaps could not have been more inopportune insofar as it coincided with a concerted effort on the part of the accounting regulators toward global harmonisation of financial reporting standards. This paper reports the findings of a survey of Company Secretaries and company provided information examining the extent to which these guidelines have been adopted by the leading public companies in the United Kingdom. The findings suggest limited acceptance and in the resource‐constrained environment of the twenty‐first century business implementation of mandatory requirements are given priority. Further research needs to be conducted to determine whether the GRI has a role to play in future stakeholder engagement

Quantifying the radiation belt seed population in the 17 March 2013 electron acceleration event

Abstract We present phase space density (PSD) observations using data from the Magnetic Electron Ion Spectrometer instrument on the Van Allen Probes for the 17 March 2013 electron acceleration event. We confirm previous results and quantify how PSD gradients depend on the first adiabatic invariant. We find a systematic difference between the lower-energy electrons (1-MeV with a source region within the radiation belts. Our observations show that the source process begins with enhancements to the 10s-100s-keV energy seed population, followed by enhancements to the \u3e1-MeV population and eventually leading to enhancements in the multi-MeV electron population these observations provide the clearest evidence to date of the timing and nature of the radial transport of a 100s keV electron seed population into the heart of the outer belt and subsequent local acceleration of those electrons to higher radiation belt energies. Key Points Quantification of phase space density gradients inside geostationary orbit Clear differences between the source of low energy and relativistic electrons Clear observations of how the acceleration process evolves in energy

Input-output analyses of the pollution content of intra- and inter-national trade flows

This paper considers the application of input-output accounting methods to consider the pollution implications of different production and consumption activities, with specific focus on pollution embodied in intra-and inter-national trade flows. We consider the illustrative case studies of interregional trade flows between two regions of the UK and between five Mid-West regions/states within the US. We focus on different types of air pollutant of current policy concern in each case and demonstrate how use of the environmental input-output framework allows us to analyse the nature and significance of interregional pollution spillovers. Our results raise questions in terms of the extent to which authorities at regional level can control local emissions where they are limited in the way some emissions can be controlled, particularly with respect to changes in demand elsewhere within the national economy. This implies a need for policy co-ordination between national and regional level authorities to meet emissions reductions targets. Moreover, the existence of pollution trade balances between regions also raises issues in terms of net losses/gains in terms of pollutants as a result of interregional trade. In conducting analyses for different types of air pollutant (here CO2 as a global warming gas, GHG, in the UK case and ammonia, NH3, as a pollutant of more local concern in the US case) we also consider how pollution embodied in international trade flows may be accounted for and attributed

Econometric estimation of Armington import elasticities and their system-wide impact in a regional CGE model of the Illinois economy

One of the main concerns associated with the development and use of regional CGE models is the determination of key parameter values, particularly substitution and other price elasticities. A common problem is the lack of appropriate regional data for econometric estimation. Consequently, it is important to identify key parameters that are likely to be important in determining quantitative results and then to prioritize these for estimation where appropriate data are available. In this paper, the focus is on the estimation of the regional trade (import) substitution parameters, which tend to be important in analysis for regional economies (given their openness to trade). Here, commodity import elasticities for the Illinois economy are estimated and tested in a single region CGE model of the Illinois economy. In our econometric estimation, we apply a model that takes account of market size and distance in estimating the substitutability between commodities produced in Illinois and other US states

Rapid estimation of sugar release from winter wheat straw during bioethanol production using FTIR-photoacoustic spectroscopy

BACKGROUND: Complexity and high cost are the main limitations for high-throughput screening methods for the estimation of the sugar release from plant materials during bioethanol production. In addition, it is important that we improve our understanding of the mechanisms by which different chemical components are affecting the degradability of plant material. In this study, Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was combined with advanced chemometrics to develop calibration models predicting the amount of sugars released after pretreatment and enzymatic hydrolysis of wheat straw during bioethanol production, and the spectra were analysed to identify components associated with recalcitrance. RESULTS: A total of 1122 wheat straw samples from nine different locations in Denmark and one location in the United Kingdom, spanning a large variation in genetic material and environmental conditions during growth, were analysed. The FTIR-PAS spectra of non-pretreated wheat straw were correlated with the measured sugar release, determined by a high-throughput pretreatment and enzymatic hydrolysis (HTPH) assay. A partial least square regression (PLSR) calibration model predicting the glucose and xylose release was developed. The interpretation of the regression coefficients revealed a positive correlation between the released glucose and xylose with easily hydrolysable compounds, such as amorphous cellulose and hemicellulose. Additionally, a negative correlation with crystalline cellulose and lignin, which inhibits cellulose and hemicellulose hydrolysis, was observed. CONCLUSIONS: FTIR-PAS was used as a reliable method for the rapid estimation of sugar release during bioethanol production. The spectra revealed that lignin inhibited the hydrolysis of polysaccharides into monomers, while the crystallinity of cellulose retarded its hydrolysis into glucose. Amorphous cellulose and xylans were found to contribute significantly to the released amounts of glucose and xylose, respectively. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13068-015-0267-2) contains supplementary material, which is available to authorized users