Showing papers by "Open University published in 2006"
TL;DR: In this article, the superiority of guided instruction is explained in the context of our knowledge of human cognitive architecture, expert-novice differences, and cognitive load, and it is shown that the advantage of guidance begins to recede only when learners have sufficiently high prior knowledge to provide "internal" guidance.
Abstract: Evidence for the superiority of guided instruction is explained in the context of our knowledge of human cognitive architecture, expert–novice differences, and cognitive load. Although unguided or minimally guided instructional approaches are very popular and intuitively appealing, the point is made that these approaches ignore both the structures that constitute human cognitive architecture and evidence from empirical studies over the past half-century that consistently indicate that minimally guided instruction is less effective and less efficient than instructional approaches that place a strong emphasis on guidance of the student learning process. The advantage of guidance begins to recede only when learners have sufficiently high prior knowledge to provide "internal" guidance. Recent developments in instructional research and instructional design models that support guidance during instruction are briefly described.
5,199 citations
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01 Jan 2006TL;DR: In this article, the authors take up the arguments for a "third area" of education (design) that were outlined by Archer, and further define this area by contrasting it with the other two (sciences and humanities) and consider the criteria which design must satisfy to be acceptable as a part of general education.
Abstract: This is the third paper in a series being published in Design Studies, which aims to establish the theoretical bases for treating design as a coherent discipline of study. The first contribution in the series was from Bruce Archer, in the very first issue of Design Studies, and the second was from Gerald Nadler, in Vol 1, No 5. Further contributions are invited. Here, Higel Cross takes up the arguments for a ‘third area’ of education—design—that were outlined by Archer. He further defines this area by contrasting it with the other two—sciences and humanities—and goes on to consider the criteria which design must satisfy to be acceptable as a part of general education. Such an acceptance must imply a reorientation from the instrumental aims of conventional design education, towards intrinsic values. These values derive from the ‘designerly ways of knowing’. Because of a common concern with these fundamental ‘ways of knowing’, both design research and design education are contributing to the development of design as a discipline.
2,593 citations
TL;DR: The SuperWASP cameras at the Observatorio del Roque de los Muchachos on the island of La Palma in the Canary Islands, and at the Sutherland Station of the South African Astronomical Observatory have a field of view of some 482 deg2 with an angular scale of 13 as mentioned in this paper.
Abstract: The SuperWASP cameras are wide‐field imaging systems at the Observatorio del Roque de los Muchachos on the island of La Palma in the Canary Islands, and at the Sutherland Station of the South African Astronomical Observatory. Each instrument has a field of view of some 482 deg2 with an angular scale of 13 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc}
ewcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2}
ormalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\farcs$\end{document} 7 pixel−1, and is capable of delivering photometry with accuracy better than 1% for objects having \documentclass{aastex} \usepackage{amsbsy} \usepa...
1,184 citations
Max Planck Society1, Leibniz Institute for Neurobiology2, Monash University, Clayton campus3, University of Montpellier4, Open University5, Thermo Electron6, German Criminal Police Office7, University of Würzburg8, University of Victoria9, University of Gothenburg10, Royal Canadian Mounted Police11, University of Tasmania12, University of Houston13, University of Mainz14, Paul Scherrer Institute15, Carnegie Institution for Science16, University of Kiel17, University of Greifswald18, University of Edinburgh19, Oregon State University20, Heidelberg University21, Utrecht University22, National Institute of Polar Research23, University of Utah24, Freiberg University of Mining and Technology25, United States Geological Survey26, Chinese Academy of Sciences27, University of Pavia28, University of Lausanne29, University of Tübingen30, Los Alamos National Laboratory31, University of Melbourne32
TL;DR: In this paper, the authors present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G and ATHO-G.
Abstract: We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented.
889 citations
Donald E. Brownlee1, Peter Tsou2, Jérôme Aléon3, Conel M. O'd. Alexander4 +182 more•Institutions (57)
TL;DR: The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study, and preliminary examination shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin.
Abstract: The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.
886 citations
TL;DR: In the context of accelerating globalization and marketization, this article analyzed the forces which are driving the adoption of English, and some of the problems which accelerating "Englishization" of European Higher Education might create.
Abstract: In the global debates on English as international lingua franca or as ‘killer language’, the adoption of English as medium of instruction in Higher Education is raising increasing concern. Plurilingualism and multilingualism are embedded in the official policies of the European Union and Council of Europe, and the Bologna Process for harmonizing Higher Education promises ‘proper provision for linguistic diversity’. But even enthusiasts acknowledge the problems of implementing such policies in the face of an inexorable increase in the use of English. This survey draws on the most recent and sometimes disparate sources in an attempt to paint a comprehensive and up-to-date picture of the spread of English-medium teaching in Europe's universities. The article sets the changes in the context of accelerating globalization and marketization, and analyses the forces which are driving the adoption of English, and some of the problems which accelerating ‘Englishization’ of European Higher Education might create.
709 citations
United States Naval Research Laboratory1, Brookhaven National Laboratory2, Space Sciences Laboratory3, Kingsborough Community College4, University of Münster5, Michigan State University6, Osaka University7, Jet Propulsion Laboratory8, Lawrence Livermore National Laboratory9, Kobe University10, European Synchrotron Radiation Facility11, Washington University in St. Louis12, University of Chicago13, École normale supérieure de Lyon14, University of New Mexico15, Kyushu University16, University of Tokyo17, University of Washington18, Lawrence Berkeley National Laboratory19, University of Jena20, University of Hawaii21, American Museum of Natural History22, Case Western Reserve University23, University of Hyogo24, United States Geological Survey25, Imperial College London26, State University of New York System27, Open University28, Stanford University29
TL;DR: The bulk of the comet 81P/Wild 2 samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger ferromagnesian silicates, Fe-Ni sulfides,Fe-Ni metal, and accessory phases.
Abstract: The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk.
644 citations
TL;DR: This analysis shows that, while there is still some way to go before semantic annotation tools will be able to address fully all the knowledge management needs, research in the area is active and making good progress.
605 citations
TL;DR: In this article, a formal system model is used as a framing device to deliver the benefits of taking account of critical success factors while avoiding the problems associated with "critical success factors" that give rise to the criticisms.
605 citations
TL;DR: The origins, assumptions, limitations, and uses of the self-controlled case series method are described, and the rationale for the model and the derivation of the likelihood are explained using a worked example on vaccine safety.
Abstract: The self-controlled case series method was developed to investigate associations between acute outcomes and transient exposures, using only data on cases, that is, on individuals who have experienced the outcome of interest. Inference is within individuals, and hence fixed covariates effects are implicitly controlled for within a proportional incidence framework. We describe the origins, assumptions, limitations, and uses of the method. The rationale for the model and the derivation of the likelihood are explained in detail using a worked example on vaccine safety. Code for fitting the model in the statistical package STATA is described. Two further vaccine safety data sets are used to illustrate a range of modelling issues and extensions of the basic model. Some brief pointers on the design of case series studies are provided. The data sets, STATA code, and further implementation details in SAS, GENSTAT and GLIM are available from an associated website.
588 citations
Ames Research Center1, Lawrence Livermore National Laboratory2, Carnegie Institution for Science3, North Carolina State University4, University of Paris-Sud5, University of Washington6, University of Kent7, University of California, Berkeley8, Goddard Space Flight Center9, Stony Brook University10, University at Albany, SUNY11, Open University12, Lawrence Berkeley National Laboratory13, University of Münster14, California Institute of Technology15, Parthenope University of Naples16, Stanford University17, Washington University in St. Louis18
TL;DR: The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage and a diverse suite of organic compounds is present and identifiable within the returned samples.
Abstract: Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples.
TL;DR: It is illustrated that the currently accepted practices concerning the 'unit of meaning' are not generally applicable to quantitative content analysis of electronic communication and recommendations are made for current content analysis practice in CSCL research.
Abstract: Quantitative content analysis is increasingly used to surpass surface level analyses in computer-supported collaborative learning (e.g., counting messages), but critical reflection on accepted practice has generally not been reported. A review of CSCL conference proceedings revealed a general vagueness in definitions of units of analysis. In general, arguments for choosing a unit were lacking and decisions made while developing the content analysis procedures were not made explicit. In this article, it will be illustrated that the currently accepted practices concerning the 'unit of meaning' are not generally applicable to quantitative content analysis of electronic communication. Such analysis is affected by 'unit boundary overlap' and contextual constraints having to do with the technology used. The analysis of e-mail communication required a different unit of analysis and segmentation procedure. This procedure proved to be reliable, and the subsequent coding of these units for quantitative analysis yielded satisfactory reliabilities. These findings have implications and recommendations for current content analysis practice in CSCL research.
TL;DR: This paper reviewed a range of difficult issues that currently face ethnographic research, and offered some reflections on them, including how ethnographers define the spatial and temporal boundaries of what they study; how they determine the context that is appropriate for understanding it; in what senses ethnography can be virtual rather than actual; the role of interviews as a data source; the relationship between ethnography and discourse analysis; the tempting parallel with imaginative writing; and, finally, whether ethnography should have, or can avoid having, political or practical commitments of some kind, beyond its aim of producing value-
Abstract: This article reviews a range of difficult issues that currently face ethnographic research, and offers some reflections on them. These issues include: how ethnographers define the spatial and temporal boundaries of what they study; how they determine the context that is appropriate for understanding it; in what senses ethnography can be—or is—virtual rather than actual; the role of interviews as a data source; the relationship between ethnography and discourse analysis; the tempting parallel with imaginative writing; and, finally, whether ethnography should have, or can avoid having, political or practical commitments of some kind, beyond its aim of producing value-relevant knowledge.
TL;DR: In this article, the authors evaluate Bourdieu's analysis of cultural production in terms of its effectiveness for understanding contemporary media production, with an emphasis on the potential advantages of his historical account over other, competing work.
Abstract: This article evaluates Bourdieu’s analysis of cultural production in terms of its effectiveness for understanding contemporary media production. I begin by outlining the main features of Bourdieu’s work on cultural production, with an emphasis on the potential advantages of his historical account over other, competing work. In particular, I stress the importance of his historical account of ‘autonomy’ and of the emphasis on the interconnectedness of the field of cultural production with other social fields. I then draw attention to two major problems in the work of Bourdieu and others who have adopted his ‘field theory’ for the media: first, that he offered only occasional and fragmented analyses of ‘large-scale’, ‘heteronomous’ (to use his terms) commercial media production, in spite of its enormous social and cultural importance in the contemporary world; second, that Bourdieu and his key associates provide only a very limited account of the relationships between cultural production and cultural consumption. In this latter context, I briefly discuss recent debates in cultural studies about cultural intermediaries. I refer to examples from recent media production to provide evidence for my arguments. The article argues that, as practised so far, Bourdieu’s field theory is only of limited value in analysing media production. However I close by discussing the potential fruitfulness of research based on a dialogue between, on the one hand, field theory’s analysis of cultural production and, on the other, Anglo-American media and cultural studies work on media production.
TL;DR: In this article, the authors argue that a more effective CO 2 policy is to concentrate on shifting to non-fossil fuels, like renewables, subsidized through a carbon tax.
TL;DR: In this article, the effectiveness of social marketing interventions to improve diet, increase physical activity, and tackle substance misuse is reviewed, and three reviews of systematic reviews and primary studies that evaluate social marketing effectiveness are presented.
TL;DR: In this paper, the authors show that fluid-peridotite and fluid-serpentinite interaction processes are an important factor regarding the budget of exchange processes between the lithosphere and the hydrosphere in slow spreading environments.
TL;DR: In this article, the authors explored SME capacity to absorb and manage knowledge as a prior condition to the successful adoption of innovations and entrepreneurial growth, drawing on the findings from more than 1,500 SME owners across regular quarterly SERTeam surveys and from other large scale studies.
Abstract: – The purpose of this article is to explore SME capacity to absorb and manage knowledge as a prior condition to the successful adoption of innovations and entrepreneurial growth., – Drawing on the findings from more than 1,500 SME owners across regular quarterly SERTeam surveys and from other large scale studies, this article examines the effects of experiential and formal knowledge on the development of SME absorptive capacity., – There were significant age, educational and size effects that influence SME acquisition and assimilation of knowledge. Primarily, it is the small firms of 15+ employees that have the capacity to absorb and use new knowledge – especially those with higher educational levels and clear growth objectives. These firms are not startups but they do tend to be younger firms with younger founders., – Given the main policy aim is the development of clusters and of knowledge‐based firms, policy makers should focus on SMEs recently started by graduates or people with technical qualifications; educators need to develop technology and innovation management programmes for these firms., – This article makes an important contribution to the identification of priorities for public SME development support and areas where business schools and enterprise trainers could maximise their economic and developmental impact.
TL;DR: In this article, the authors stress the significance of non-formal learning, and the ways in which it can be promoted and enhanced within the activity systems within which teachers in higher education work.
Abstract: Educational professional development is a global concern. It is often characterised by event‐delivery methods, though there are signs that other approaches are gaining favour. The authors stress the significance of non‐formal learning, and the ways in which it can be promoted and enhanced within the activity systems within which teachers in higher education work. Their argument is complemented by findings from a study of 2401 part‐time teachers, and online responses from 248 full‐time staff, in the UK Open University. Twelve implications for international practice are identified.
TL;DR: The experiment provides support for both the competitive exclusion and pool size hypotheses for determination of species density and suggests that comparisons among sites, nutrient inputs, especially N treatments, or soil acidity may in general underestimate the threat posed to plant species diversity by long-term changes in plant nutrient availability, both enrichment and depletion.
Abstract: The Park Grass Experiment, begun in 1856, is the oldest ecological experiment in existence. Its value to science has changed and grown since it was founded to answer agricultural questions. In recent times the experiment has shown inter alia how: plant species richness, biomass and pH are related; community composition responds to climatic perturbation and nutrient additions; soil is acidified and corrected by liming. It also provided one of the first demonstrations of the evolution of adaptation at a very local scale and contains a putative case of the evolution of reproductive isolation by reinforcement. The application of molecular genetic markers to archived plant material promises to reveal a whole new chapter of genetic detail about the long-term dynamics of plant populations. Over the range of values observed at Park Grass, biomass (productivity) has a negative effect upon species richness. Any positive effect of species richness on productivity could only be weak by comparison. The experiment provides support for both the competitive exclusion and pool size hypotheses for determination of species density. Instantaneous comparisons of species richness between plots do not accurately reflect temporal rates of loss which may be multiplicative rather than additive. This suggests that comparisons among sites, nutrient inputs, especially N treatments, or soil acidity may in general underestimate the threat posed to plant species diversity by long-term changes in plant nutrient availability, both enrichment and depletion. Differences between plots at the community level are maintained despite a flow of propagules between plots. There is no strong evidence for a spatial mass effect. Guild (grass/legume/other) compositions of plant communities have equilibrated, but the species composition within guilds is more dynamic and continues to change over time, suggesting that species and guild abundances are independently regulated. At least some members of all the major trophic levels, including predators (spiders), herbivores (leafhoppers) and detritivores (springtails) are treatment-specific in their distributions. Plant populations on Park Grass are subdivided by treatments which, to some degree, have led to plots becoming genetically isolated from one another and decoupled demographically. This subdivision has created a metapopulation structure in each species, characterized by species-specific rates of local colonization and extinction. Inverse clines in flowering time occur in the grass Anthoxanthum odoratum across some plot boundaries. These suggest that reproductive isolation between plots has been reinforced by natural selection. Drift as well as selection may have taken place in A. odoratum, especially on plots where effective population size is restricted by population bottlenecks caused by drought. Park Grass illustrates how long-term experiments grow in value with time and how they may be used to investigate scientific questions that were inconceivable at their inception. This is as likely to be true of the future of Park Grass as it has proved to be of its past.
TL;DR: For example, against the cartographic opposition between cities and nature in modern western societies, the idea of urban ecology has seemed little more than a contradiction in terms as mentioned in this paper. But things are brewing in...
Abstract: Against the cartographic opposition between cities and natures in modern western societies the idea of urban ecology has seemed little more than a contradiction in terms. But things are brewing in ...
TL;DR: This paper conducted a longitudinal text-oriented ethnographic study of psychology scholars in Hungary, Slovakia, Spain and Portugal to follow the trajectories of texts from local research and writing contexts to English-medium publications.
Abstract: Scholars around the world are under increasing pressure to publish their research in the medium of English. However, little empirical research has explored how the global premium of English influences the academic text production of scholars working outside of English-speaking countries. This article draws on a longitudinal text-oriented ethnographic study of psychology scholars in Hungary, Slovakia, Spain and Portugal to follow the trajectories of texts from local research and writing contexts to English-medium publications. Our findings indicate that a significant number of mediators, ‘literacy brokers’, who are involved in the production of such texts, influence the texts in different and important ways. We illustrate in broad terms the nature and extent of literacy brokering in English-medium publications and characterize and exemplify brokers’ different orientations. We explore what kind of brokering is evident in the production of a specific group of English-medium publications- articles written and published in English medium inyternational journals-by focising on three text histories. We conclude by discussing what a focus on brokering can tell us can tell us about practices surrounding academic knowledge production.
TL;DR: This work reports the selection of DNA aptamers that bind with high affinity and selectivity to the MUC1 peptides, a well-known tumour marker present in a variety of malignant tumours and a target of interest for many years.
Abstract: Agents able to bind tightly and selectively to disease markers can greatly benefit disease diagnosis and therapy. Aptamers are functional molecules, usually DNA or RNA oligonucleotides, with the appro
02 Oct 2006
TL;DR: SemSearch is presented, a search engine, which pays special attention to semantic search by providing several means to hide the complexity of semantic search from end users and thus make it easy to use and effective.
Abstract: Existing semantic search tools have been primarily designed to enhance the performance of traditional search technologies but with little support for ordinary end users who are not necessarily familiar with domain specific semantic data, ontologies, or SQL-like query languages. This paper presents SemSearch, a search engine, which pays special attention to this issue by providing several means to hide the complexity of semantic search from end users and thus make it easy to use and effective.
TL;DR: In this article, a conceptual framework is developed to accommodate the often neglected collective or pluralistic dimension of entrepreneurship, focusing on the creation of a social enterprise (cooperative, mutual or voluntary organisation).
Abstract: Purpose – This paper is concerned with developing a framework which allows both economic and social entrepreneurship to be analysed.Design/methodology/approach – The framework is developed to accommodate the often neglected collective or pluralistic dimension of entrepreneurship. It draws on the behavioural approach to adopt a straightforward definition of social entrepreneurship – focusing on the creation of a social enterprise (co‐operative, mutual or voluntary organisation). The paper is exploratory, developing a conceptual framework, based on some case studies of social enterprises in a range of business sectors, in the UK.Findings – The findings from this small scale study provide interesting models of entrepreneurship that contrast with conventional models for SMEs.Research limitations/implications – The research has implications for research on conventional entrepreneurship, as well as creating a basis for developing the new field of social entrepreneurship.Practical implications – The paper provid...
TL;DR: In this article, the authors assess current developments in the theory and practice of supply management and through such an assessment to identify barriers, possibilities and key trends, they conclude that supply management is, at best, still emergent in terms of both theory and practices.
Abstract: Purpose – The purpose of this paper is to critically assess current developments in the theory and practice of supply management and through such an assessment to identify barriers, possibilities and key trends.Design/methodology/approach – The paper is based on a three‐year detailed study of six supply chains which encompassed 72 companies in Europe. The focal firms in each instance were sophisticated, blue‐chip corporations operating on an international scale. Managers across at least four echelons of the supply chain were interviewed and the supply chains were traced and observed.Findings – The paper reveals that supply management is, at best, still emergent in terms of both theory and practice. Few practitioners were able – or even seriously aspired – to extend their reach across the supply chain in the manner prescribed in much modern theory. The paper identifies the range of key barriers and enablers to supply management and it concludes with an assessment of the main trends.Research limitations/imp...
TL;DR: ENGIN-X as mentioned in this paper, a new time-of-flight (TOF) neutron diffractometer optimized to measure elastic strains at precise locations in bulky specimens recently commissioned at the ISIS Facility in the Rutherford Laboratory, UK, is described.
Abstract: ENGIN-X, a new time-of-flight (TOF) neutron diffractometer optimized to measure elastic strains at precise locations in bulky specimens recently commissioned at the ISIS Facility in the Rutherford Laboratory, UK, is described. Fast counting times, together with a flexible and accurate definition of the instrumental gauge volume are the main requirements of neutron strain scanning and have been addressed on ENGIN-X through the design of a novel TOF diffractometer with a tuneable resolution and interchangeable radial collimators. Further, the routine operation of the instrument has been optimized by creating a virtual instrument, i.e. a three-dimensional computer representation of the diffractometer and samples, which assists in the planning and execution of experiments. On comparing ENGIN-X with its predecessor ENGIN, a 25× gain in performance is found, which has allowed the determination of stresses up to 60 mm deep in steel specimens. For comparison with constant-wavelength diffractometers, special attention has been paid to the absolute number of counts recorded during the experiments. A simple expression is presented for the estimation of counting times in TOF neutron strain scanning experiments.
Lawrence Livermore National Laboratory1, Open University2, University of Washington3, University of Kent4, University of California, San Diego5, University of Chicago6, Washington University in St. Louis7, Max Planck Society8, Natural History Museum9, Lille University of Science and Technology10, University of California, Berkeley11, University of Münster12, United States Naval Research Laboratory13, Spanish National Research Council14, California Institute of Technology15
TL;DR: Particles emanating from comet 81P/Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth.
Abstract: Particles emanating from comet 81P/Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth. The morphologies of these surprisingly diverse features were created by particles varying from dense mineral grains to loosely bound, polymineralic aggregates ranging from tens of nanometers to hundreds of micrometers in size. The cumulative size distribution of Wild 2 dust is shallower than that of comet Halley, yet steeper than that of comet Grigg-Skjellerup.
TL;DR: In this article, the authors track the entanglement of cultural and natural histories through the residual material culture of a derelict homestead in Montana, and suggest that deposits of degraded material, though inappropriate for recovery in conventional conservation strategies, may be understood through the application of a collaborative interpretive ethic, allowing other-than-human agencies to participate in the telling of stories about particular places.
Abstract: The degradation of cultural artefacts is usually understood in a purely negative vein: the erosion of physical integrity is associated with a parallel loss of cultural information. This article asks if it is possible to adopt an interpretive approach in which entropic processes of decomposition and decay, though implicated in the destruction of cultural memory traces on one register, contribute to the recovery of memory on another register. The article tracks the entanglement of cultural and natural histories through the residual material culture of a derelict homestead in Montana. In conclusion, the article suggests that deposits of degraded material, though inappropriate for recovery in conventional conservation strategies, may be understood through the application of a collaborative interpretive ethic, allowing other-than-human agencies to participate in the telling of stories about particular places.
TL;DR: It is more likely that the Earth will next experience a super-eruption than an impact from a large meteorite greater than 1 km in diameter, and major disruption of services that society depends upon can be expected for periods of months to years after the next very large explosive eruption.
Abstract: Every now and again Earth experiences tremendous explosive volcanic eruptions, considerably bigger than the largest witnessed in historic times. Those yielding more than 450km3 of magma have been called super-eruptions. The record of such eruptions is incomplete; the most recent known example occurred 26000 years ago. It is more likely that the Earth will next experience a super-eruption than an impact from a large meteorite greater than 1km in diameter. Depending on where the volcano is located, the effects will be felt globally or at least by a whole hemisphere. Large areas will be devastated by pyroclastic flow deposits, and the more widely dispersed ash falls will be laid down over continent-sized areas. The most widespread effects will be derived from volcanic gases, sulphur gases being particularly important. This gas is converted into sulphuric acid aerosols in the stratosphere and layers of aerosol can cover the global atmosphere within a few weeks to months. These remain for several years and affect atmospheric circulation causing surface temperature to fall in many regions. Effects include temporary reductions in light levels and severe and unseasonable weather (including cool summers and colder-than-normal winters). Some aspects of the understanding and prediction of super-eruptions are problematic because they are well outside modern experience. Our global society is now very different to that affected by past, modest-sized volcanic activity and is highly vulnerable to catastrophic damage of infrastructure by natural disasters. Major disruption of services that society depends upon can be expected for periods of months to, perhaps, years after the next very large explosive eruption and the cost to global financial markets will be high and sustained.