A preliminary characterization of the tensile and fatigue behavior of tungsten-fiber/Waspaloy-matrix composite

A microstructural study and a preliminary characterization of the room temperature tensile and fatigue behavior of a continuous, tungsten fiber, Waspaloy-matrix composite was conducted. A heat treatment was chosen that would allow visibility of planar slip if it occurred during deformation, but would not allow growth of the reaction zone. Tensile and fatigue tests showed that the failed specimens contained transverse cracks in the fibers. The cracks that occurred in the tensile specimen were observed at the fracture surface and up to approximately 4.0 mm below the fracture surface. The crack spacing remained constant along the entire length of the cracked fibers. Conversely, the cracks that occurred in the fatigue specimen were only observed in the vicinity of the fracture surface. In instances where two fiber cracks occurred in the same plane, the matrix often necked between the two cracked fibers. Large groups of slip bands were generated in the matrix near the fiber cracks. Slip bands in the matrix of the tensile specimen were also observed in areas where there were no fiber cracks, at distances greater than 4 mm from the fracture surface. This suggests that the matrix plastically flows before fiber cracking occurs

The Chelsea Critical Care Physical Assessment Tool (CPAx): validation of an innovative new tool to measure physical morbidity in the general adult critical care population; an observational proof-of-concept pilot study.

Objective To develop a scoring system to measure physical morbidity in critical care – the Chelsea Critical Care Physical Assessment Tool (CPAx). Method The development process was iterative involving content validity indices (CVI), a focus group and an observational study of 33 patients to test construct validity against the Medical Research Council score for muscle strength, peak cough flow, Australian Therapy Outcome Measures score, Glasgow Coma Scale score, Bloomsbury sedation score, Sequential Organ Failure Assessment score, Short Form 36 (SF-36) score, days of mechanical ventilation and inter-rater reliability. Participants Trauma and general critical care patients from two London teaching hospitals. Results Users of the CPAx felt that it possessed content validity, giving a final CVI of 1.00 (P < 0.05). Construct validation data showed moderate to strong significant correlations between the CPAx score and all secondary measures, apart from the mental component of the SF-36 which demonstrated weak correlation with the CPAx score (r = 0.024, P = 0.720). Reliability testing showed internal consistency of α = 0.798 and inter-rater reliability of κ = 0.988 (95% confidence interval 0.791 to 1.000) between five raters. Conclusion This pilot work supports proof of concept of the CPAx as a measure of physical morbidity in the critical care population, and is a cogent argument for further investigation of the scoring system

Multi-Pulse Laser Wakefield Acceleration: A New Route to Efficient, High-Repetition-Rate Plasma Accelerators and High Flux Radiation Sources

Laser-driven plasma accelerators can generate accelerating gradients three orders of magnitude larger than radio-frequency accelerators and have achieved beam energies above 1 GeV in centimetre long stages. However, the pulse repetition rate and wall-plug efficiency of plasma accelerators is limited by the driving laser to less than approximately 1 Hz and 0.1% respectively. Here we investigate the prospects for exciting the plasma wave with trains of low-energy laser pulses rather than a single high-energy pulse. Resonantly exciting the wakefield in this way would enable the use of different technologies, such as fibre or thin-disc lasers, which are able to operate at multi-kilohertz pulse repetition rates and with wall-plug efficiencies two orders of magnitude higher than current laser systems. We outline the parameters of efficient, GeV-scale, 10-kHz plasma accelerators and show that they could drive compact X-ray sources with average photon fluxes comparable to those of third-generation light source but with significantly improved temporal resolution. Likewise FEL operation could be driven with comparable peak power but with significantly larger repetition rates than extant FELs

Messing with nature? Exploring public perceptions of geoengineering in the UK

Anthropogenic influence on the climate – and possible societal responses to it – offers a unique window through which to examine the way people think about and relate to the natural world. This paper reports data from four, one-day deliberative workshops conducted with members of the UK public during early 2012. The workshops focused on geoengineering – the deliberate, large-scale manipulation of the planetary environment – as one of three possible responses to climate change (alongside mitigation and adaptation). Here, we explore one of the most pervasive and wide-ranging themes to emerge from the workshops: whether geoengineering represented an unprecedented human intervention into ‘nature’, and what the moral consequences of this might be. Using the concept of ‘messing with nature’ as an analytical lens, we explore public perceptions of geoengineering. We also reflect on why ‘messing with nature’ was such a focal point for debate and disagreement, and whether the prospect of geoengineering may reveal new dimensions to the way that people think about the natural world, and their relationship to it

Manifestos

31 pages. A Great Bear Pamphlet; no. 8. CONTENTS : Word power / Alison Knowles -- Answers to manifesto puzzle -- Rainbow manifesto / Ay-o -- Western civilization is done with ... / Philip Corner -- Manifesto of the W.E.B. DuBois Clubs -- Take care of the world / Oyvind Fahlström -- A proposition, a problem, a danger and a hunch / Robert Filliou -- We hold ... / John Giorno -- Manifesto / [Robert Watts] -- Lettuce manifesto / Al Hansen -- A Something Else manifesto / Dick Higgins -- Once, the task of the artist was ... / Allan Kaprow -- Cybernated art is very important ... ; Utopian laser TV station / Nam June Paik -- And I open my mouth ... / Diter Rot -- Program / Jerome Rothenberg -- Instead of bombs ... / Wolf Vostell -- abeeiillmmmsttwy / [Emmett Williams]. Stapled binding. Gift of Richard Liebler. 2nd copy gift of Estera Milman, RISD Class of 1970. Estera Milman (RISD BFA Painting/Printmaking and Film, 1970) scholar of post-World War II avant-garde art. Founded Alternative Traditions in Contemporary Art (ATCA) at the University of Iowa, 1982, and served as its director until 2000. She is the author of many books, articles, interviews, and exhibition catalogs on Fluxus and No!art. In December 2018 she donated a selection of books from her library to the Fleet Library at RISD. Curated title for Fleet Library Special Collections exhibition By Hand: Women & Books Exhibit fall, 2021.https://digitalcommons.risd.edu/specialcollections_artistsbooks/1253/thumbnail.jp

On Torsion-Free Crawley Groups

The notion of a Crawley p-group is well known in Abelian group theory. In this present work, a corresponding concept is introduced for torsion-free groups. The principal result, which uses the set-theoretic notions of the diamond and Martin’s axiom, establishes an independence result for N1-free Crawley groups

Laserwire at the Accelerator Test Facility 2 with Sub-Micrometre Resolution

A laserwire transverse electron beam size measurement system has been developed and operated at the Accelerator Test Facility 2 (ATF2) at KEK. Special electron beam optics were developed to create an approximately 1 x 100 {\mu}m (vertical x horizontal) electron beam at the laserwire location, which was profiled using a 150 mJ, 71 ps laser pulse with a wavelength of 532 nm. The precise characterisation of the laser propagation allows the non-Gaussian transverse profiles of the electron beam caused by the laser divergence to be deconvolved. A minimum vertical electron beam size of 1.07 ${\pm}$ 0.06 (stat.) ${\pm}$ 0.05 (sys.) {\mu}m was measured. A vertically focussing quadrupole just before the laserwire was varied whilst making laserwire measurements and the projected vertical emittance was measured to be 82.56 ${\pm}$ 3.04 pm rad.Comment: 17 pages, 26 figures, submitted to Phys. Rev. ST Accel. Beam

Making the most of community energies:Three perspectives on grassroots innovation

Grassroots innovations for sustainability are attracting increasing policy attention. Drawing upon a wide range of empirical research into community energy in the UK, and taking recent support from national government as a case study, we apply three distinct analytical perspectives: strategic niche management; niche policy advocacy; and critical niches. Whilst the first and second perspectives appear to explain policy influence in grassroots innovation adequately, each also shuts out more transformational possibilities. We therefore argue that, if grassroots innovation is to realise its full potential, then we need to also pursue a third, critical niches perspective, and open up debate about more socially transformative pathways to sustainability