443 research outputs found
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Job quality in Europe
Promoting job quality and gender equality are objectives of the European Employment
Strategy (EES) in spite of a downgrading of the attention given to both in the
revised employment guidelines and the re-launch of the Lisbon Process. However,
advances on both of these objectives may be important complements to the employment
rate targets of the EES, as access to good quality jobs for both sexes is likely to
help sustain higher employment rates. While the European Commission has a broad
view of the concept of job quality in practice, it relies on a selection of labour market
type indicators that say little about the quality of the actual jobs people do. Using
data from the 2005 European Working Conditions survey, we analyse job quality
along three dimensions: job content, autonomy and working conditions. We conclude
that gender and occupational status, along with other job characteristics such as
working time and sector, have more influence on an individual’s job quality than the
country or ‘national model’ they are situated in. Our results also demonstrate the
value of developing indicators of job quality that are both gender sensitive and
derived at the level of the job rather than the labour market in order to advance EU
policy and academic debate on this topic
Survival of fossils under extreme shocks induced by hypervelocity impacts
Experimental data are shown for survival of fossilized diatoms undergoing shocks in the GPa range. The results were obtained from hypervelocity impact experiments which fired fossilized diatoms frozen in ice into water targets. After the shots, the material recovered from the target water was inspected for diatom fossils. Nine shots were carried out, at speeds from 0.388 to 5.34?km?s?1, corresponding to mean peak pressures of 0.2–19?GPa. In all cases, fragmented fossilized diatoms were recovered, but both the mean and the maximum fragment size decreased with increasing impact speed and hence peak pressure. Examples of intact diatoms were found after the impacts, even in some of the higher speed shots, but their frequency and size decreased significantly at the higher speeds. This is the first demonstration that fossils can survive and be transferred from projectile to target in hypervelocity impacts, implying that it is possible that, as suggested by other authors, terrestrial rocks ejected from the Earth by giant impacts from space, and which then strike the Moon, may successfully transfer terrestrial fossils to the Moon
Ranking workplace competencies: Student and graduate perceptions
Students and graduates from a variety of business studies programs at a New Zealand tertiary institution completed a questionnaire in which they ranked the relative importance of a list of 24 competencies for graduates entering the workforce using a 7-point Likert scale. These competencies were identified from literature reports of the characteristics of superior performers in the workplace. The results show a close similarity between students and graduates’ ranking of competencies with computer literacy, customer service orientation, teamwork and co-operation, self-confidence, and willingness to learn ranked most important. There was little difference between the two groups in their rankings of cognitive or ‘hard’ skills and behavioral or ‘soft’ skills. However, the graduates placed greater importance on most of the competencies, resulting in a statistically significant difference between the graduates and students’ ranking of both hard and soft skills. The findings from this study suggest that cooperative education programs may help develop business students’ awareness of the importance of graduate competencies in the workplace
Survival of Organic Materials in Hypervelocity Impacts of Ice on Sand, Ice, and Water in the Laboratory
The survival of organic molecules in shock impact events has been investigated in the laboratory. A frozen mixture of anthracene and stearic acid, solvated in dimethylsulfoxide (DMSO), was fired in a two-stage light gas gun at speeds of ?2 and ?4?km s?1 at targets that included water ice, water, and sand. This involved shock pressures in the range of 2–12 GPa. It was found that the projectile materials were present in elevated quantities in the targets after impact and in some cases in the crater ejecta as well. For DMSO impacting water at 1.9?km s?1 and 45° incidence, we quantify the surviving fraction after impact as 0.44±0.05. This demonstrates successful transfer of organic compounds from projectile to target in high-speed impacts. The range of impact speeds used covers that involved in impacts of terrestrial meteorites on the Moon, as well as impacts in the outer Solar System on icy bodies such as Pluto. The results provide laboratory evidence that suggests that exogenous delivery of complex organic molecules from icy impactors is a viable source of such material on target bodies
DRAGONS - A Micrometeoroid and Orbital Debris Impact Sensor
The Debris Resistive/Acoustic Grid Orbital Navy Sensor (DRAGONS) is intended to be a large area impact sensor for in-situ measurements of micrometeoroids and orbital debris (MMOD) in the approx.0.2 to 1 mm size regime. These MMOD particles are too small to be detected by groundbased radars and optical telescopes, but still large enough to be a safety concern for human space activities and robotic missions in the low Earth orbit (LEO) region. The nominal detection area of DRAGONS is 1 sq m, consisting of four 0.5 m x 0.5 m independently operated panels. The concept of the DRAGONS design is to combine three different detection technologies to maximize information extracted from each detected impact. The first technology is a resistive grid consisting of 62.5-microns-wide resistive lines, coated in parallel and separated by 62.5 micron gaps on a Kapton film. When a particle a few hundred micrometers or larger strikes the grid, it world penetrate the film and sever some resistive lines. The size of the damage area can be estimated from the increased resistance. The second technology employs a dual-layer, 25-microns-thick Kapton film with a 10 cm separation. By measuring the time difference between impacts on the two films, the impact speed can be calculated. The third technology is based on polyvinylidene fluoride (PVDF) acoustic impact sensors. Multiple PVDF sensors are attached to the backside of both Kapton films to provide impact timing measurements. The impact location on each film can be identified from the triangulation of signals received at different PVDF sensors and provides an estimate of the impact direction. The development of DRAGONS is supported by the NASA Orbital Debris Program Office. The project is led by the U.S. Naval Academy (USNA), with additional collaboration from the U.S. Naval Research Laboratory (NRL), the University of Kent at Canterbury in Great Britain, and Virginia Tech (VT). The short-term goal of DRAGONS is to advance its Technology Readiness Level to 9 and to demonstrate the system capabilities of detecting and characterizing submillimeter MMOD impacts. The long-term goal is to deploy a large detection area (>1 sq m) DRAGONS to 700-1000 km altitude and collect sufficient data for better environment definition of MMOD in the 0.2- to 1-mm size regime. The Preliminary Design Review (PRD) of DRAGONS was held at the USNA in June 2012. The Critical Design Review (CDR) is scheduled for early 2013. A flight-ready unit with a 0.25 sq m detection area will be completed and tested by the end of September 2013. The biggest challenge for the project, however, is to identify a demonstration opportunity on the International Space Station in the coming years
Creating Calibration Curves to Determine Shock Pressure in Clinopyroxene
Impact cratering is an important geological process that occurs on every rocky body in the solar system. It alters the texture and mineralogy of rocks via shock metamorphism. The peak shock pressures experienced by a rock are traditionally evaluated using qualitative optical methods however, quantitative methods do exist. One such method was developed by Uchizono et al., who used X-ray Diffraction (XRD) to measure lattice strain () in several artificially shocked olivine grains using XRD peak broadening as a function of tan , where is the diffraction angle. They plotted the values against the known peak shock pressures experienced by the olivine grains. Using this calibration curve, the precise shock pressure experienced by a grain of olivine can be determined using its measured value. Another method was developed by McCausland et al. and Izawa et al., who used in situ XRD to measure strain-related mosaicity (SRM) of olivine in several ordinary chondrites and enstatite in enstatite chondrites, respectively. They plotted these results against the shock stage estimates for these meteorites. Using these plots, meteorites can be assigned to shock stage bins by measuring the SRM of olivine and/or enstatite. Both methods are useful for evaluating shock metamorphism, however, they have limitations. Uchizono et al.s calibration curve has been successfully applied to martian meteorites, however it can only be applied to olivine-bearing rocks. McCausland et al.s and Izawa et al.s SRM method is uncalibrated and is limited to binning meteorites by shock stage. This work aims to expand on both methods by creating calibration curves for clinopyroxene (CPX): one for , similar to Uchizono et al.s calibration curve for olivine, and one for SRM. This will extend the application of shock calibration methods to a greater variety of rock types. Preliminary results are presented herein
Should we screen for intracranial aneurysms (IAs) in systemic hypertension at the time of cardiac magnetic resonance (CMR)?
Catastrophic Disruption of Hollow Ice Spheres
Catastrophic disruption is a possible outcome of high-speed collisions in the solar system. The critical energy density Q* (impact energy/mass of the target), which is taken to mark the onset of catastrophic disruption, occurs when the largest intact fragment post-impact is 50% of the original target mass. Studies of Q* usually suppose the target body is a solid, rigid object. However, what if the body has a rigid shell and a hollow interior? Here, hollow ice spheres (a diameter of 19–20 cm with an ice thickness of 2.5–3.6 cm) were impacted at speeds up to ∼5 km/s. Catastrophic disruption occurred at Q* ∼ 25.5 ± 0.5 J kg−1, greater than that for similar size solid, or water-filled ice spheres (16–18 J kg−1). However, while the Q* value has increased, the actual impact energy associated with the new value of Q* has not, and the change in Q* arises due to the lower mass of the hollow target bodie
Non-Random Spatial Distribution of Impacts in the Stardust Cometary Collector
In January 2004, the Stardust spacecraft flew through the coma of comet P81/Wild2 at a relative speed of 6.1 km/sec. Cometary dust was collected at in a 0.1 sq m collector consisting of aerogel tiles and aluminum foils. Two years later, the samples successfully returned to earth and were recovered. We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than approx.10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a noncometary impact on the spacecraft bus just forward of the collector. Here we summarize the observations, and review the evidence for and against three scenarios that we have considered for explaining the impact clustering found on the Stardust aerogel and foil collectors
Are systolic function and ejection fraction interchangeable? New insights from cardiovascular magnetic resonance and in-vivo validation of mathematical models of LV function
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