Case attrition in rape cases: a comparative analysis

The past decade has seen a number of legal, practice and policy-based interventions made in order to ensure that the criminal justice system is more responsive to rape complaints. At their most instrumental, the aim of both shifts in practice and in the laws relating to sexual offences is to increase reporting and conviction rates in rape cases. One of the greatest problems with the criminal justice system's response to rape remains, however, that most reported cases do not in fact make it through the system to trial. This article reflects on two attrition studies conducted by the authors between 2003 and 2006, together examining the disposition of approximately 600 rape cases across six urban police stations. The objective of these studies was to examine the processing, investigation and prosecution of sexual offences cases and to analyse the possible reasons for high attrition. This paper raises the complexities of calculating attrition as well as the extent to which international experiences and perspectives on rape attrition converge and contrast with South African ones. We also set out to develop some of the insights that we have garnered from our own attrition studies and thereby to alert scholars working in this area to the key practical and theoretical issues that arise in conceptualising and conducting an attrition study

A phenomenological study of occupational engagement in recovery from mental illness

This study aimed to uncover the meaning of occupation for 13 people who self identified as being in recovery from mental illness. Recovery narratives were collected from the participants in a series of open ended conversational interviews that were recorded and transcribed. The interview transcripts were analysed using phenomenological and hermeneutic approaches, with a focus on participants’ descriptions of engagement in everyday occupations. A range of experiences were evident, from complete disengagement to complete absorption in occupations. Participants described significant shifts in their experience of time, space, body and other people while in different modes of occupation and these were captured under the themes of ‘non-doing’, ‘half-doing’, ‘engaged doing’ and ‘absorbed doing’. Each mode had the potential to support recovery by creating opportunities for participants to reconnect with aspects of their being-in-the-world. The findings highlight the dynamics at play in different modes of occupation and suggest that all forms of engagement, including disengagement, can be significant in the recovery process. A greater understanding of the dynamics of occupation for people experiencing mental illness will enable carers and mental health services to more effectively support people in their recovery

Thermal oxidative degradation reactions of perfluoroalklethers

The objective of this contract was to investigate the mechanisms operative in thermal and thermal oxidative degradation of Fomblin Z and hexafluoropropene oxide derived fluids and the effect of alloys and additives upon these processes. The nature of arrangements responsible for the inherent thermal oxidative instability of the Fomblin Z fluids has not been established. It was determined that this behavior was not associated with hydrogen end-groups or peroxy linkages. The degradation rate of these fluids at elevated temperatures in oxidizing atmospheres was found to be dependent on the surface/volume ratio. Once a limiting ratio was reached, a steady rate appeared to be attained. Based on elemental analysis and oxygen consumption data, -CF2OCF2CF2O-, not -CF2CF2O-, is one of the major arrangements present. The action of the M-50 and Ti(4 Al, 4 Mn) alloys was found to be much more drastic in the case of Fomblin Z fluids than that observed for the hexalfuoropropane oxide derived materials. The effectiveness of antioxidation/anticorrosion additives, P-3 and phospha-s-triazine, in the presence of metal alloys was very limited at 316 C; at 288 C the additives arrested almost completely the fluid degradation. The phospha-s-triazine appeared to be at least twice as effective as the P-3 compound; it also protected the coupon better. The Ti(4 Al, 4 Mn) alloy degraded the fluid mainly by chain scission processes; this took place to a much lesser degree with M-50

Long range polarization attraction between two different likely charged macroions

It is known that in a water solution with multivalent counterions (Z-ions), two likely charged macroions can attract each other due to correlations of Z-ions adsorbed on their surfaces. This "correlation" attraction is short-ranged and decays exponentially with increasing distance between macroions at characteristic distance A/2\pi, where A is the average distance between Z-ions on the surfaces of macroions. In this work, we show that an additional long range "polarization" attraction exists when the bare surface charge densities of the two macroions have the same sign, but are different in absolute values. The key idea is that with adsorbed Z-ions, two insulating macroions can be considered as conductors with fixed but different electric potentials. Each potential is determined by the difference between the entropic bulk chemical potential of a Z-ion and its correlation chemical potential at the surface of the macroion determined by its bare surface charge density. When the two macroions are close enough, they get polarized in such a way that their adjacent spots form a charged capacitor, which leads to attraction. In a salt free solution this polarization attractive force is long ranged: it decays as a power of the distance between the surfaces of two macroions, d. The polarization force decays slower than the van der Waals attraction and therefore is much larger than it in a large range of distances. In the presence of large amount of monovalent salt, when A/2\pi<< d<< r_s (r_s is the Debye-H\"{u}ckel screening radius), this force is still much stronger than the van der Waals attraction and the correlation attraction mentioned above.Comment: 12 pages, 7 figures. Small change in the text, no change in result

The effects of metals and inhibitors on thermal oxidative degradation reactions of unbranched perfluoroalkylethers

Thermal oxidative degradation studies were performed on unbranched perfluoroalkylethers at 288 C in oxygen. Metals and alloys studied included Ti, Al, and Ti (4 Al, 4 Mn). The mechanism of degradation was by chain scission. Ti and Al promoted less degradation than Ti (4 Al, 4 Mn). The two inhibitors investigated (a perfluorophenyl phosphine and a phosphatriazine) reduced degradation rates by several orders of magnitude. Both inhibitors were effective for the same duration (75 to 100 hours). The phosphatriazine appeared to provide more surface protection

Nanomechanical displacement detection using coherent transport in ordered and disordered graphene nanoribbon resonators

Graphene nanoribbons provide an opportunity to integrate phase-coherent transport phenomena with nanoelectromechanical systems (NEMS). Due to the strain induced by a deflection in a graphene nanoribbon resonator, coherent electron transport and mechanical deformations couple. As the electrons in graphene have a Fermi wavelength \lambda ~ a_0 = 1.4 {\AA}, this coupling can be used for sensitive displacement detection in both armchair and zigzag graphene nanoribbon NEMS. Here it is shown that for ordered as well as disordered ribbon systems of length L, a strain \epsilon ~ (w/L)^2 due to a deflection w leads to a relative change in conductance \delta G/G ~ (w^2/a_0L).Comment: 4 Pages, 4 figure

Interaction of vortices in thin superconducting films and Berezinskii-Kosterlitz-Thouless transition

The precondition for the BKT transition in thin superconducting films, the logarithmic intervortex interaction, is satisfied at distances short relative to $\Lambda=2\lambda^2/d$, $\lambda$ is the London penetration depth of the bulk material and $d$ is the film thickness. For this reason, the search for the transition has been conducted in samples of the size $L<\Lambda$. It is argued below that film edges turn the interaction into near exponential (short-range) thus making the BKT transition impossible. If however the substrate is superconducting and separated from the film by an insulated layer, the logarithmic intervortex interaction is recovered and the BKT transition should be observable.Comment: 4 pages, no figure

Bridging the Divide in Work and Occupational Psychology: Evidence From Practice

This study explores the extent to which work and organizational (W&O) psychology practitioners use evidence, how they apply it to the everyday contexts in which they work and the types of barriers they encounter in so doing. It adopts a mixed methods approach involving the administration of a survey to a UK sample (N=163) of W&O psychologists and a series of semi-structured interviews (N=25) exploring in greater depth how evidence is applied in practice. Findings reveal that practitioners consult a wide range of different types of evidence which they employ at various stages of engagement with client organisations and that this evidence is pressed into service in the pursuit of solutions which are both acceptable from the client perspective and consistent with the scientific standards underpinning professional knowledge and expertise in W&O psychology. Barriers to evidence-use were mainly practical in nature, concerning issues around managing the client-consultant relationship and the particularities of implementation context, both of which were shown to influence evidence utilisation. The study contributes to current debate on the extent to which W&O psychologists adopt an evidence-based approach and provides a valuable and much called-for empirical insight into the enactment of the scientist-practitioner model in W&O psycholog

Electronic states and optical properties of PbSe nanorods and nanowires

A theory of the electronic structure and excitonic absorption spectra of PbS and PbSe nanowires and nanorods in the framework of a four-band effective mass model is presented. Calculations conducted for PbSe show that dielectric contrast dramatically strengthens the exciton binding in narrow nanowires and nanorods. However, the self-interaction energies of the electron and hole nearly cancel the Coulomb binding, and as a result the optical absorption spectra are practically unaffected by the strong dielectric contrast between PbSe and the surrounding medium. Measurements of the size-dependent absorption spectra of colloidal PbSe nanorods are also presented. Using room-temperature energy-band parameters extracted from the optical spectra of spherical PbSe nanocrystals, the theory provides good quantitative agreement with the measured spectra.Comment: 35 pages, 12 figure

A Multi-scale Approach for Simulations of Kelvin Probe Force Microscopy with Atomic Resolution

The distance dependence and atomic-scale contrast observed in nominal contact potential difference (CPD) signals recorded by KPFM on surfaces of insulating and semiconducting samples, have stimulated theoretical attempts to explain such effects. We attack this problem in two steps. First, the electrostatics of the macroscopic tip-cantilever-sample system is treated by a finite-difference method on an adjustable nonuniform mesh. Then the resulting electric field under the tip apex is inserted into a series of atomistic wavelet-based density functional theory (DFT) calculations. Results are shown for a realistic neutral but reactive silicon nano-scale tip interacting with a NaCl(001) sample. Bias-dependent forces and resulting atomic displacements are computed to within an unprecedented accuracy. Theoretical expressions for amplitude modulation (AM) and frequency modulation (FM) KPFM signals and for the corresponding local contact potential differences (LCPD) are obtained by combining the macroscopic and atomistic contributions to the electrostatic force component generated at the voltage modulation frequency, and evaluated for several tip oscillation amplitudes A up to 10 nm. Being essentially constant over a few Volts, the slope of atomistic force versus bias is the basic quantity which determines variations of the atomic-scale LCPD contrast. Already above A = 0.1 nm, the LCPD contrasts in both modes exhibit almost the same spatial dependence as the slope. In the AM mode, this contrast is approximately proportional to $A^{-1/2}$, but remains much weaker than the contrast in the FM mode, which drops somewhat faster as A is increased. These trends are a consequence of the macroscopic contributions to the KPFM signal, which are stronger in the AM-mode and especially important if the sample is an insulator even at sub-nanometer separations where atomic-scale contrast appears.Comment: 19 pages, 13 figure