340 research outputs found
New Divisions of Labour?: Comparative Thoughts on the Current Recession
This article argues that it is useful to compare the current recession with that which occurred three decades ago. Drawing on research undertaken at that time by Ray Pahl, it is suggested that four questions are once again revealing in the study of the current economic downturn: \'How have we come to be where we are currently?\', \'Who gets what?\', \'How do we know what we claim to know?\', and \'What sorts of lessons can be drawn to inform thinking about the future?\' The usefulness of asking these questions is discussed, even though the answers must await further research.Recession, Divisions of Labour, Community
An Observing Campaign to Monitor the Reentry of the Automated Transfer Vehicle "Jules Verne" in August 2008
This presentation was part of the session : Sample Return ChallengesSixth International Planetary Probe WorkshopThe next great opportunity to investigate aspects of entry and descent dynamics is the reentry of ESA's Automated Transfer Vehicle (ATV) called "Jules Verne". This first in a series of ATVs was launched on March 9, 2008. It has a function similar to that of the Russian Progress, a re-supply ship for the International Space Station (ISS). It is scheduled to dock with ISS in April, then undock in early August. An observing campaign is being organized to monitor the reentry of the 15-ton ATV-1 over the south Pacific ocean on August 8. An international team of researchers from governments, universities, and private institutions will deploy from NASA Ames Research Center in California, travel to the staging area, and field a wide range of imagers and spectrographs to record the manner in which ATV breaks during entry. This data is expected to constrain the model uncertainties in the size of the debris footprint and help ensure future safe returns of ATV.ESA, NAS
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Micromechanics of sea ice frictional slip from test basin scale experiments
We have conducted a series of high-resolution friction experiments on large floating saline ice floes in an environmental test basin. In these experiments, a central ice floe was pushed between two other floes, sliding along two interfacial faults. The frictional motion was predominantly stick–slip. Shear stresses, normal stresses, local strains and slip displacement were measured along the sliding faults, and acoustic emissions were monitored. High-resolution measurements during a single stick–slip cycle at several positions along the fault allowed us to identify two phases of frictional slip: a nucleation phase, where a nucleation zone begins to slip before the rest of the fault, and a propagation phase when the entire fault is slipping. This is slip-weakening behaviour. We have therefore characterized what we consider to be a key deformation mechanism in Arctic Ocean dynamics. In order to understand the micromechanics of sea ice friction, we have employed a theoretical constitutive relation (i.e. an equation for shear stress in terms of temperature, normal load, acceleration, velocity and slip displacement) derived from the physics of asperity–asperity contact and sliding (Hatton et al. 2009 Phil. Mag. 89, 2771–2799 (doi:10.1080/14786430903113769)). We find that our experimental data conform reasonably with this frictional law once slip weakening is introduced. We find that the constitutive relation follows Archard's law rather than Amontons' law, with Embedded Image (where τ is the shear stress and σn is the normal stress) and n = 26/27, with a fractal asperity distribution, where the frictional shear stress, τ = ffractal Tmlws, where ffractal is the fractal asperity height distribution, Tml is the shear strength for frictional melting and lubrication and ws is the slip weakening. We can therefore deduce that the interfacial faults failed in shear for these experimental conditions through processes of brittle failure of asperities in shear, and, at higher velocities, through frictional heating, localized surface melting and hydrodynamic lubrication
Numerical simulations of the flow and sediment transport regimes surrounding a short cylinder
Author Posting. © IEEE, 2007. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 32 (2007): 249-259, doi:10.1109/JOE.2007.890986.The 3-D flow field and bed stress surrounding a short cylinder in response to combined wave and mean-flow forcing events is examined. Model simulations are performed with a 3-D nonhydrostatic computational fluid dynamics model, FLOW-3D. The model is forced with a range of characteristic tidal and wave velocities as observed in 12–15 m of water at the Martha's Vineyard Coastal Observatory (MVCO, Edgartown, MA). The 2.4-m-long and 0.5-m diameter cylinder is buried 10% of the diameter on a flat, fixed bed. Regions of incipient motion are identified through local estimates of the Shields parameter exceeding the critical value. Potential areas of sediment deposition are identified with local estimates of the Rouse parameter exceeding ten. The model predictions of sediment response are in general in agreement with field observations of seabed morphology obtained over a one-week period during the 2003–2004 MVCO mine burial experiment. Both observations and simulations show potential transport occurring at the ends of the mine in wave-dominated events. Mean flows greater than 10 cm/s lead to the formation of larger scour pits upstream of the cylinder. Deposition in both cases tends to occur along the sides, near the center of mass of the mine. However, the fixed-bed assumption prohibits the prediction of full perimeter scour as is observed in nature. Predicted scour and burial regimes for a range of wave and mean-flow combinations are established.This work was supported in part by the U.S. Office of Naval
Research under the mine burial project N00014-00-1-0570. The work of K. A.
Hatton was supported by the National Science Foundation Graduate Research
Fellowship
Framing an independent, integrated and evidence-based evaluation of the state of Australia's biophysical and human environments
A new approach was developed for Australia's 2011 national State of the Environment (SoE) report to integrate the assessment of biophysical and human elements of the environment. A Common Assessment and Reporting Framework (CARF) guided design and implementation, responding to jurisdictional complexity, outstanding natural diversity and ecosystem values, high levels of cultural and heritage diversity, and a paucity of national-scale data. The CARF provided a transparent response to the need for an independent, robust and evidence-based national SoE report. We conclude that this framework will be effective for subsequent national SoE assessments and other integrated national-scale assessments in data-poor regions.The work reported here was funded and supported by
DSEWPaC, and we recognise the high level of professional support provided by the DSEWPaC
SoE Team and other staff, the professional support of Biotext information consultancy (biotext.
com.au), the vision of the commissioning Minister for Environment Protection, Heritage and the
Arts (Peter Garrett) in presenting us with this challenge, and the support of the presenting Minister
for Sustainability, Environment, Water, Population and Communities (Tony Burke) in accepting
and delivering the final report to Australia
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Critical slip and time dependence in sea ice friction
Recent research into sea ice friction has focussed on ways to provide a model which maintains much of the clarity and simplicity of Amonton's law, yet also accounts for memory effects. One promising avenue of research has been to adapt the rate- and state- dependent models which are prevalent in rock friction. In such models it is assumed that there is some fixed critical slip displacement, which is effectively a measure of the displacement over which memory effects might be considered important. Here we show experimentally that a fixed critical slip displacement is not a valid assumption in ice friction, whereas a constant critical slip time appears to hold across a range of parameters and scales. As a simple rule of thumb, memory effects persist to a significant level for 10 s. We then discuss the implications of this finding for modelling sea ice friction and for our understanding of friction in general
Measuring Metacognition in Cancer: Validation of the Metacognitions Questionnaire 30 (MCQ-30)
Objective
The Metacognitions Questionnaire 30 assesses metacognitive beliefs and processes which are central to the metacognitive model of emotional disorder. As recent studies have begun to explore the utility of this model for understanding emotional distress after cancer diagnosis, it is important also to assess the validity of the Metacognitions Questionnaire 30 for use in cancer populations.
Methods
229 patients with primary breast or prostate cancer completed the Metacognitions Questionnaire 30 and the Hospital Anxiety and Depression Scale pre-treatment and again 12 months later. The structure and validity of the Metacognitions Questionnaire 30 were assessed using factor analyses and structural equation modelling.
Results
Confirmatory and exploratory factor analyses provided evidence supporting the validity of the previously published 5-factor structure of the Metacognitions Questionnaire 30. Specifically, both pre-treatment and 12 months later, this solution provided the best fit to the data and all items loaded on their expected factors. Structural equation modelling indicated that two dimensions of metacognition (positive and negative beliefs about worry) were significantly associated with anxiety and depression as predicted, providing further evidence of validity.
Conclusions
These findings provide initial evidence that the Metacognitions Questionnaire 30 is a valid measure for use in cancer populations
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The use of drama to teach social skills in a special school setting for students with autism.
For children with autism, social challenges may be both part of the disability and a barrier to accessing education. This paper reports on a project which used drama to address such challenges by drawing on the social skills of non-autistic peers in a special school setting. The paper demonstrates how drama’s flexibility may be harnessed in order to help students support each other’s development of creative and communicative skills. Focusing on two children in particular, specific examples are given to illustrate how they participated in group work, made imaginative contributions to verbal and physical representations, and engaged with abstract ideas. The project’s outcomes suggest, given a concrete structure and an invitation to collaborate, drama can be a powerful learning medium for children with ASD. The conclusion reflects on the diverse meaning of inclusive practice which can be achieved within specialist settings
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Improving evidence-based practice through preregistration of applied research: barriers and recommendations
Preregistration is the practice of publicly publishing plans on central components of the research process before access to, or collection, of data. Within the context of the replication crisis, open science practices like preregistration have been pivotal in facilitating greater transparency in research. However, such practices have been applied nearly exclusively to basic academic research, with rare consideration of the relevance to applied and consultancy-based research. This is particularly problematic as such research is typically reported with very low levels of transparency and accountability despite being disseminated as influential grey literature to inform practice. Evidence-based practice is best served by an appreciation of multiple sources of quality evidence, thus the current review considers the potential of preregistration to improve both the accessibility and credibility of applied research towards more rigorous evidence-based practice. The current three-part review outlines, first, the opportunities of preregistration for applied research, and second, three barriers - practical challenges, stakeholder roles, and the suitability of preregistration. Last, this review makes four recommendations to overcome these barriers and maximise the opportunities of preregistration for academics, industry, and the structures they are held within - changes to preregistration templates, new types of templates, education and training, and recognition and structural changes
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