Influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors

In a recent paper [B. A. Piot et al., Phys. Rev. B 72, 245325 (2005)], we have shown that the lifting of the electron spin degeneracy in the integer quantum Hall effect at high filling factors should be interpreted as a magnetic-field-induced Stoner transition. In this work, we extend the analysis to investigate the influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors. The single-particle Zeeman energy is tuned through the application of an additional in-plane magnetic field. Both the evolution of the spin polarization of the system and the critical magnetic field for spin splitting are well described as a function of the tilt angle of the sample in the magnetic field.Comment: Published in Phys. Rev.

Moisture susceptibility of high and low compaction dry process crumb rubber modified asphalt mixtures

The field performance of dry process crumb rubber-modified (CRM) asphalt mixtures has been reported to be inconsistent with stripping and premature cracking on the surfacing. One of the concerns is that, because achieving field compaction of CRM material is difficult due to the inherent resilient nature of the rubber particle, nonuniform field compaction may lead to a deficient bond between rubber and bitumen. To assess the influence of compaction, a series of CRM and control mixtures was produced and compacted at two levels: 4% (low, optimum laboratory compaction) and 8% (high, field experience) air void content. The long-term durability, in regard to moisture susceptibility of the mixtures, was assessed by conducting repeated moisture conditioning cycles. Mechanical properties (stiffness, fatigue, and resistance to permanent deformation) were determined in the Nottingham Asphalt Tester. Results indicated that compared with conventional mixtures, the CRM mixtures, regardless of compaction effort, are more susceptible to moisture with the degree of susceptibility primarily depending on the amount of rubber in the mixture, rather than the difference in compaction. This behavior is different from that of conventional mixtures in which, as expected, poorly compacted mixtures were found to be more susceptible to moisture than were well-compacted mixtures

Data compression approach for long-term monitoring of pavement structures

Pavement structures are designed to withstand continuous damage during their design life. Damage starts as soon as the pavement is open to traffic and increases with time. If maintenance activities are not considered in the initial design or considered but not applied during the service life, damage will grow to a point where rehabilitation may be the only and most expensive option left. In order to monitor the evolution of damage and its severity in pavement structures, a novel data compression approach based on cumulative measurements from a piezoelectric sensor is presented in this paper. Specifically, the piezoelectric sensor uses a thin film of polyvinylidene fluoride to sense the energy produced by the micro deformation generated due to the application of traffic loads. Epoxy solution has been used to encapsulate the membrane providing hardness and flexibility to withstand the high-loads and the high-temperatures during construction of the asphalt layer. The piezoelectric sensors have been exposed to three months of loading (approximately 1.0 million loads of 65 kN) at the French Institute of Science and Technology for Transport, Development and Networks (IFSTTAR) fatigue carrousel. Notably, the sensors survived the construction and testing. Reference measurements were made with a commercial conventional strain gauge specifically designed for measurements in hot mix asphalt layers. Results from the carrousel successfully demonstrate that the novel approach can be considered as a good indicator of damage progression, thus alleviating the need to measure strains in pavement for the purpose of damage tracking

Experimental evaluation of cohesive and adhesive bond strength and fracture energy of bitumen-aggregate systems

Degradation of asphalt pavements is an inevitable phenomenon due to the combined effects of high traffic loads and harsh environmental conditions. Deterioration can be in the form of cohesive failure of the bitumen and/or bitumen-filler mastic or by adhesive failure between bitumen and aggregate. This paper presents an experimental investigation to characterise the cohesive and adhesive strength and fracture energy of bitumen-aggregate samples. The pneumatic adhesion tensile testing instrument test and the peel test were used to quantify the tensile fracture strength and fracture energy of different bitumen-aggregate combinations, with a view to analyse the influence of several parameters on the strength of the bitumen film or bitumen-aggregate interface. From the experimental results, harder (40/60 pen) bitumen tends to show much higher tensile strength and fracture energy than softer (70/100 pen) bitumen. Tensile strength is shown to be sensitive to testing temperature with the failure regime changing from cohesive to mixed cohesive/adhesive failure with decreasing temperature. In addition, the results show that aggregate properties do not influence the bonding strength if cohesive failure occurs, but with adhesive failure, granite aggregate tends to produce a higher bonding strength than limestone aggregate in the dry condition. In terms of the peel test, the fracture energy experienced an increasing trend with increasing film thickness. However, the normalised toughness decreased when film thickness increased from 0.2 to 0.9 mm

How people with chronic illnesses view their care in general practice: a qualitative study

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Objectives: To explore the perceptions of patients with chronic conditions about the nature and quality of their care in general practice. Design: Qualitative study using focus group methods conducted 1 June to 30 November 2002. Participants and setting: 76 consumers in 12 focus groups in New South Wales and South Australia. Main outcome measures: Recurring issues and themes on care received in general practice. Results: Three groups of priorities emerged. One centred on the quality of doctors, including technical competence, interpersonal skills, time for the patient in the consultation and continuity of care. A second concerned the role of patients and consumer organisations, with patients wanting (i) recognition of their knowledge about their condition and self-management, and (ii) for GPs to develop closer links with consumer organisations and inform patients about them. The third focused on the practice team and the importance of practice nurses and receptionists. Conclusion: GPs should consider the amount of time they spend with chronically ill patients, and their interpersonal skills and understanding of patients’ needs. They need to be better informed about the benefits of patient self-management and consumer organisations, and to incorporate them into their care. They also need to review how their practice nurses and receptionists can maximise the care of patients.Fernando A Infante, Judith G Proudfoot, Gawaine Powell Davies, Tanya K Bubner, Chris H Holton, Justin J Beilby and Mark F Harri

Geometric morphometrics defines shape differences in the cortical area map of C57BL/6J and DBA/2J inbred mice

BACKGROUND: We previously described planar areal differences in adult mouse visual, somatosensory, and neocortex that collectively discriminated C57BL/6J and DBA/2J inbred strain identity. Here we use a novel application of established methods of two-dimensional geometric morphometrics to examine shape differences in the cortical area maps of these inbred strains. RESULTS: We used Procrustes superimposition to align a reliable set of landmarks in the plane of the cortical sheet from tangential sections stained for the cytochrome oxidase enzyme. Procrustes superimposition translates landmark configurations to a common origin, scales them to a common size, and rotates them to minimize an estimate of error. Remaining variation represents shape differences. We compared the variation in shape between C57BL/6J and DBA/2J relative to that within each strain using a permutation test of Goodall's F statistic. Significant differences in shape in the posterior medial barrel subfield (PMBSF), as well as differences in shape across primary sensory areas, characterize the cortical area maps of these common inbred, isogenic strains. CONCLUSION: C57BL/6J and DBA/2J have markedly different cortical area maps, in both size and shape. These differences suggest polymorphism in genetic factors underlying cortical specification, even between common isogenic strains. Comparing cortical phenotypes between normally varying inbred mice or between genetically modified mice can identify genetic contributions to cortical specification. Geometric morphometric analysis of shape represents an additional quantitative tool for the study of cortical development, regardless of whether it is studied from phenotype to gene or gene to phenotype

Disability in young adults following major trauma: 5 year follow up of survivors

BACKGROUND: Injuries are a major cause of mortality and morbidity in young people. Despite this, the long-term consequences for young survivors of severe injury are relatively unexplored. METHODS: Population based cohort study involving 5 year post injury structured interview of all cases of major trauma (Injury Severity Score > 15) identified retrospectively for 12 month period (1988 to 1989) within former Yorkshire Health Authority area of the United Kingdom. RESULTS: 125 individuals aged 11–24 years at time of injury were identified. Of these, 109 (87%) were interviewed. Only 20% (95% CI 14–29%) of those interviewed reported no disability. Mean Office of Population Census and Surveys (OPCS) disability score of the remainder was 7.5 (median 5.8, range 0.5 to 19.4). The most commonly encountered areas of disability were behaviour (54%, 95% CI 45–63%), intellectual functioning (39%, 95% CI 31–49%) and locomotion (29%, 95% CI 22–39%). Many respondents reported that their daily lives were adversely affected by their health problems for example, causing problems with work, 54% (95% CI 45–63%), or looking after the home, 28% (95% CI 21–38%). Higher OPCS scores were usually but not always associated with greater impact on daily activities. The burden of caring responsibilities fell largely on informal carers. 51% (95% CI 42–61%) of those interviewed would have liked additional help to cope with their injury and disability. CONCLUSION: The study has revealed significant disability amongst a cohort of young people 5 years post severe injury. Whilst many of these young people were coping well with the consequences of their injuries, others reported continuing problems with the activities of daily life. The factors underpinning the young people's differing experiences and social outcome should be explored