4,028 research outputs found
Seismic Design Basis — The UK Regulatory Position for New Nuclear Reactors
The purpose of this paper is to outline the seismic regulatory requirements relating to the site licensing of new nuclear power installations in the UK, and to describe the background and justification of the seismic design basis level for such installations. It outlines the potential seismic related hazards which should be covered, the factors which are considered important in establishing the level of hazard under consideration, and the techniques which could be used for hazard evaluation. In addition, the paper covers the level of uncertainty associated with the methodology and analytical techniques used in evaluating the seismic hazards
Dynamics of aircraft antiskid braking systems
A computer study was performed to assess the accuracy of three brake pressure-torque mathematical models. The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The investigation indicates that the performance of aircraft antiskid braking systems is strongly influenced by tire characteristics, dynamic response of the antiskid control valve, and pressure-torque response of the brake. The computer study employed an average torque error criterion to assess the accuracy of the models. The results indicate that a variable nonlinear spring with hysteresis memory function models the pressure-torque response of the brake more accurately than currently used models
Determination of erythromycin in serum and urine by high performance liquid chromatography with ultraviolet detection
A high-performance liquid chromatographic analysis of erythromycin in human serum and urine with UV detection at 200 nm is presented. The method involves a solid-phase extraction procedure followed by a simple phase separation step and chromatography on a reversed-phase column. The method has sensitivity limits of 0.25 and 1.0 g/mL in serum and urine, respectively, and is sufficiently sensitive to monitor concentrations of erythromycin in human serum and urine after the administration of a single 500-mg erythromycin stearate tablet
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A comparison between ion characteristics observed by the POLAR and DMSP spacecraft in the high-latitude magnetosphere
We study here the injection and transport of ions in the convection-dominated region of the Earth’s magnetosphere. The total ion counts from the CAMMICE MICS instrument aboard the POLAR spacecraft are used to generate occurrence probability distributions of magnetospheric ion populations. MICS ion spectra are characterised by both the peak in the differential energy flux, and the average energy of ions striking the detector. The former permits a comparison with the Stubbs et al. (2001) survey of He2+ ions of solar wind origin within the magnetosphere. The latter can address the occurrences of various classifications of precipitating particle fluxes observed in the topside ionosphere by DMSP satellites (Newell and Meng, 1992). The peak energy occurrences are consistent with our earlier work, including the dawn-dusk asymmetry with enhanced occurrences on the dawn flank at low energies, switching to the dusk flank at higher energies. The differences in the ion energies observed in these two studies can be explained by drift orbit effects and acceleration processes at the magnetopause, and in the tail current sheet. Near noon at average ion energies of _1 keV, the cusp and open LLBL occur further poleward here than in the Newell and Meng survey, probably due to convectionrelated time-of-flight effects. An important new result is that the pre-noon bias previously observed in the LLBL is most likely due to the component of this population on closed field lines, formed largely by low energy ions drifting earthward from the tail. There is no evidence here of mass and momentum transfer from the solar wind to the LLBL by nonreconnection coupling. At higher energies (_2–20 keV), we observe ions mapping to the auroral oval and can distinguish between the boundary and central plasma sheets. We show that ions at these energies relate to a transition from dawnward to duskward dominated flow, this is evidence of how ion drift orbits in the tail influence the location and behaviour of the plasma populations in the magnetosphere
Computational fluid dynamics for nuclear thermal propulsion
Viewgraphs on computational fluid dynamics (CFD) for nuclear thermal propulsion are presented. Topics covered include: hydrogen mass fraction as a function of chamber temperature; specific enthalpy of hydrogen and mole fraction of hydrogen as a function of chamber pressure; and specific impulse as a function of chamber pressure. Wall configurations of several nozzles are shown
Nasal Carriage of Staphylococcus aureus in Australian (pre-clinical and clinical) Medical Students
The nasal carriage of Staphylococcus aureus in 808 Australian medical students was studied. Five groups of students experienced varying degrees of clinical exposure in a hospital environment ranging from 0 to 42 months. The overall percentage of carriers among the five groups did not vary. However, with increasing clinical exposure there was a decrease in the percentage of isolates sensitive to all antibiotics tested, and an increase in the carriage of S. aureus resistant to three or more antibiotics. No carriers of methicillin-resistant S. aureus (MRSA) were detected. The comparative rates of S. aureus carriage between female and male students varied. The relevance of medical students as nasal carriers of S. aureus in the hospital environment today is discussed
Justice Reinvestment as Social Justice
This chapter draws on the work of the Australian Justice Reinvestment Project (AJRP) (Brown et al., 2015). The AJRP examined the development of justice reinvestment particularly in the context of it’s alignment with broad social justice values. We are also specifically interested in how and whether justice reinvestment can meet the needs of those social groups that have been adversely affected by mass imprisonment and hyper-incarceration, particularly racial and Indigenous minorities, women and people with mental health issues and cognitive impairment (Cunneen et al., 2013). We argue that justice reinvestment was in its early development strongly tied to civil rights, particularly with the focus on imprisonment and racialization, and social justice for communities where large numbers of residents were recycled in and out of prison
Pressure ulcer related pain in community populations: a prevalence survey.
BACKGROUND: Pressure ulcers are costly to the healthcare provider and can have a major impact on patient's quality of life. One of the most distressing symptoms reported is pain. There is very little published data on the prevalence and details of pain experienced by patients with pressure ulcers, particularly in community populations. The study was conducted in two community NHS sites in the North of England. METHODS: The aim was to estimate the prevalence of pressure area related pain within a community population. We also explored the type and severity of the pain and its association with pressure ulcer classification. A cross-sectional survey was performed of community nurses caseloads to identify adult patients with pressure ulcers and associated pain. Consenting patients then had a full pain assessment and verification of pressure ulcer grade. RESULTS: A total of 287 patients were identified with pressure ulcers (0.51 per 1000 adult population). Of the 176 patients who were asked, 133 (75.6%) reported pain. 37 patients consented to a detailed pain assessment. Painful pressure ulcers of all grades and on nearly all body sites were identified. Pain intensity was not related to number or severity of pressure ulcer. Both inflammatory and neuropathic pain were reported at all body sites however the proportion of neuropathic pain was greater in pressure ulcers on lower limbs. CONCLUSIONS: This study has identified the extent and type of pain suffered by community patients with pressure ulcers and indicates the need for systematic and regular pain assessment and treatment
Discovery and Characterization of a Caustic Crossing Microlensing Event in the SMC
We present photometric observations and analysis of the second microlensing
event detected towards the Small Magellanic Cloud (SMC), MACHO Alert 98-SMC-1.
This event was detected early enough to allow intensive observation of the
lightcurve. These observations revealed 98-SMC-1 to be the first caustic
crossing, binary microlensing event towards the Magellanic Clouds to be
discovered in progress.
Frequent coverage of the evolving lightcurve allowed an accurate prediction
for the date of the source crossing out of the lens caustic structure. The
caustic crossing temporal width, along with the angular size of the source
star, measures the proper motion of the lens with respect to the source, and
thus allows an estimate of the location of the lens. Lenses located in the
Galactic halo would have a velocity projected to the SMC of v^hat ~1500 km/s,
while an SMC lens would typically have v^hat ~60 km/s.
We have performed a joint fit to the MACHO/GMAN data presented here,
including recent EROS data of this event. These joint data are sufficient to
constrain the time for the lens to move an angle equal to the source angular
radius; 0.116 +/- 0.010 days. We estimate a radius for the lensed source of 1.4
+/- 0.1 R_sun. This yields a projected velocity of v^hat = 84 +/- 9 km/s. Only
0.15% of halo lenses would be expected to have a v^hat value at least as small
as this, while 31% of SMC lenses would be expected to have v^hat as large as
this. This implies that the lensing system is more likely to reside in the SMC
than in the Galactic halo.Comment: 16 pages, including 3 tables and 3 figures; submitted to The
Astrophysical Journa
Physical activity and healthy ageing: A systematic review and meta-analysis of longitudinal cohort studies.
BACKGROUND: Older people constitute a significant proportion of the total population and their number is projected to increase by more than half by 2030. This increasing probability of late survival comes with considerable individual, economic and social impact. Physical activity (PA) can influence the ageing process but the specific relationship with healthy ageing (HA) is unclear. METHODS: We conducted a systematic review and meta-analysis of longitudinal studies examining the associations of PA with HA. Studies were identified from a systematic search across major electronic databases from inception as January 2017. Random-effect meta-analysis was performed to calculate a pooled effect size (ES) and 95% CIs. Studies were assessed for methodological quality. RESULTS: Overall, 23 studies were identified including 174,114 participants (30% men) with age ranges from 20 to 87 years old. There was considerable heterogeneity in the definition and measurement of HA and PA. Most of the identified studies reported a significant positive association of PA with HA, six reported a non-significant. Meta-analysis revealed that PA is positively associated with HA (ES: 1.39, 95% CI=1.23-1.57, n=17) even if adjusted for publication bias (ES: 1.27, 95% CI=1.11-1.45, n=20). CONCLUSIONS: There is consistent evidence from longitudinal observational studies that PA is positively associated with HA, regardless of definition and measurement. Future research should focus on the implementation of a single metric of HA, on the use of objective measures for PA assessment and on a full-range of confounding adjustment. In addition, our research indicated the limited research on ageing in low-and-middle income countries
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