Density functional theory of the trapped Fermi gas in the unitary regime

We investigate a density-functional theory (DFT) approach for an unpolarized trapped dilute Fermi gas in the unitary limit . A reformulation of the recent work of T. Papenbrock [Phys. Rev. A, {\bf 72}, 041602(R) (2005)] in the language of fractional exclusion statistics allows us to obtain an estimate of the universal factor, $\xi_{3D}$, in three dimensions (3D), in addition to providing a systematic treatment of finite-$N$ corrections. We show that in 3D, finite-$N$ corrections lead to unphysical values for $\xi_{3D}$, thereby suggesting that a simple DFT applied to a small number of particles may not be suitable in 3D. We then perform an analogous calculation for the two-dimensional (2D) system in the infinite-scattering length regime, and obtain a value of $\xi_{2D}=1$. Owing to the unique properties of the Thomas-Fermi energy density-functional in 2D our result, in contrast to 3D, is {\em exact} and therefore requires no finite-$N$ corrections

The social creation of a legal reality : a study of the emergence and acceptance of the British patent system as a legal instrument for the control of new technology

SIGLEAvailable from British Library Document Supply Centre- DSC:D36016/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Diagnosis and Treatment of Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) is the most frequent hyperglycaemic acute diabetic complication. Furthermore it carries a significant risk of death, which can be prevented by early and effective management. All physicians, irrespective of the discipline they are working in and whether in primary, secondary or tertiary care institutions, should be able to recognise DKA early and initiate management immediately. South African Family Practice Vol. 50 (1) 2008: pp. 35-3

Magnetoplasmon excitations in an array of periodically modulated quantum wires

Motivated by the recent experiment of Hochgraefe et al., we have investigated the magnetoplasmon excitations in a periodic array of quantum wires with a periodic modulation along the wire direction. The equilibrium and dynamic properties of the system are treated self-consistently within the Thomas-Fermi-Dirac-von Weizsaecker approximation. A calculation of the dynamical response of the system to a far-infrared radiation field reveals a resonant anticrossing between the Kohn mode and a finite-wavevector longitudinal excitation which is induced by the density modulation along the wires. Our theoretical calculations are found to be in excellent agreement with experiment.Comment: 9 pages, 8 figure

Constructing a Sophistication Index as a Method of Market Segmentation of Commercial Farming Businesses in South Africa

This study investigates the process of index construction as a means of measuring a hypothetical construct that can typically not be measured by a single question or item and applying it as a method of market segmentation. The availability of incidental secondary data provided a relevant quantitative basis to illustrate this process by constructing a commercial farming sophistication index for South Africa. It was evident that this approach offers an appropriate and useful means of segmenting a market. Several factors contribute to the appeal of this approach. Among others, it addresses important priorities in the area of future segmentation research. By offering classification rules based on characteristics that can easily be observed or elicited through asking a few key questions, new or potential buyers can be grouped by buying behaviour segment. Furthermore, the multi-step process that was employed provides a systematic and structured multivariate approach to segmentation. It also facilitates replication of the process when conducting future studies. Lastly, the outcome of this type of segmentation method offers researchers and marketing practitioners a procedure, in the form of an equation, to calculate index scores and provide rules to segment the market based on predefined intervals. Hence, the challenge to replicate segment formation across independent future studies is addressed.Keywords: Agribusiness, Commercial Farming, Index Construction, Segmentation, Sophisticatio

Deregulation of Lesotho's maize market

During the past year, there have been major policy reforms in Lesotho and South Africa with respect to maize pricing and marketing. In Lesotho the impact of deregulation on producers, consumers and government revenues was substantially lower than it should have been, and as a result Lesotho was not able to reap the full benefits of these changes. This is partly because information on the changes to the maize marketing system did not reach the potential beneficiaries of the new system. Free and easily accessible information is an essential element of a free market system. SACU countries must ensure the availability of information if they want to compete internationally.Agricultural and Food Policy, Crop Production/Industries,

‘One cannot legislate kindness’: Ambiguities in European legal instruments on non-custodial sanctions

Non-custodial sanctions, particularly those that are implemented in the community, have different historical roots in common- and civil-law jurisdictions. Nevertheless, various European instruments seek to shape the imposition and implementation of such sanctions uniformly across the continent. These instruments reflect an apparent consensus about penal values, culminating in 1992 with the adoption of the European Rules on Community Sanctions and Measures and of the Recommendation on Consistency in Sentencing. In spite of the apparent pan-European consensus, some tensions remained as a result of underlying doctrinal differences and of the compromises that were required to accommodate them. In the 21st century further European initiatives have sought to go beyond the 1992 instruments and focus on ‘what works’ and on the development of probation services. In the process, the central objective of penal reductionism, so important in 1992, has become somewhat marginalised. This shortcoming can be addressed by reconsidering the approaches that had been rejected in the earlier search for consensus and by developing a more comprehensive understanding of the human rights safeguards to which all penal sanctions should be subject

Experimental Investigation of Internal Fluidisation Due to a Vertical Water Leak Jet in a Uniform Medium

AbstractThis paper presents an experimental study on internal fluidisation which can occur in the soil outside of a leak in a buried water distribution pipe. The study proposes an experimental method of measuring excess pore pressure and flow velocity in an uniform glass beads medium surrounding the leak. One flow rate of 2 l/min at a fixed leak diameter of 3mm was used in the experiments. The results showed large velocities directly outside the inlet (in the fluidised zone), which decreased rapidly with increasing distance. The surplus pressure in the bed rises to a maximum value at the top of the fluidised zone, after which it decreases towards the top of the bed

Calibration artefacts in radio interferometry. I. Ghost sources in WSRT data

This work investigates a particular class of artefacts, or ghost sources, in radio interferometric images. Earlier observations with (and simulations of) the Westerbork Synthesis Radio Telescope (WSRT) suggested that these were due to calibration with incomplete sky models. A theoretical framework is derived that validates this suggestion, and provides predictions of ghost formation in a two-source scenario. The predictions are found to accurately match the result of simulations, and qualitatively reproduce the ghosts previously seen in observational data. The theory also provides explanations for many previously puzzling features of these artefacts (regular geometry, PSF-like sidelobes, seeming independence on model flux), and shows that the observed phenomenon of flux suppression affecting unmodelled sources is due to the same mechanism. We demonstrate that this ghost formation mechanism is a fundamental feature of calibration, and exhibits a particularly strong and localized signature due to array redundancy. To some extent this mechanism will affect all observations (including those with non-redundant arrays), though in most cases the ghosts remain hidden below the noise or masked by other instrumental artefacts. The implications of such errors on future deep observations are discussed.Comment: 19 pages, 15 figures, submitted to MNRA