4,023 research outputs found
Observation of Neutrons with a Gadolinium Doped Water Cerenkov Detector
Spontaneous and induced fission in Special Nuclear Material (SNM) such as
235U and 239Pu results in the emission of neutrons and high energy gamma-rays.
The multiplicities of and time correlations between these particles are both
powerful indicators of the presence of fissile material. Detectors sensitive to
these signatures are consequently useful for nuclear material monitoring,
search, and characterization. In this article, we demonstrate sensitivity to
both high energy gamma-rays and neutrons with a water Cerenkov based detector.
Electrons in the detector medium, scattered by gamma-ray interactions, are
detected by their Cerenkov light emission. Sensitivity to neutrons is enhanced
by the addition of a gadolinium compound to the water in low concentrations.
Cerenkov light is similarly produced by an 8 MeV gamma-ray cascade following
neutron capture on the gadolinium. The large solid angle coverage and high
intrinsic efficiency of this detection approach can provide robust and low cost
neutron and gamma-ray detection with a single device.Comment: 7 pages, 4 figures. Submitted to Nuclear Instruments and Methods,
Identification. The missing link between joint attention and imitation
In this paper we outline our hypothesis that human intersubjective engagement entails identifying with other people. We tested a prediction derived from this hypothesis that concerned the relation between a component of joint attention and a specific form of imitation. The empirical investigation involved âblindâ ratings of videotapes from a recent study in which we tested matched children with and without autism for their propensity to imitate the self-/other-orientated aspects of another person's actions. The results were in keeping with three a priori predictions, as follows: (a) children with autism contrasted with control participants in spending more time looking at the objects acted upon and less time looking at the tester; (b) participants with autism showed fewer âsharingâ looks toward the tester, and although they also showed fewer âcheckingâ and âorientatingâ looks, they were specifically less likely to show any sharing looks; and, critically, (c) within each group, individual differences in sharing looks (only) were associated with imitation of selfâother orientation. We suggest that the propensity to adopt the bodily anchored psychological stance of another person is essential to certain forms of joint attention and imitation, and that a weak tendency to identify with others is pivotal for the developmental psychopathology of autism
Patenting and licensing of university research: promoting innovation or undermining academic values?
Since the 1980s in the US and the 1990s in Europe, patenting and licensing activities by universities have massively increased. This is strongly encouraged by governments throughout the Western world. Many regard academic patenting as essential to achieve 'knowledge transfer' from academia to industry. This trend has far-reaching consequences for access to the fruits of academic research and so the question arises whether the current policies are indeed promoting innovation or whether they are instead a symptom of a pro-intellectual property (IP) culture which is blind to adverse effects. Addressing this question requires both empirical analysis (how real is the link between academic patenting and licensing and 'development' of academic research by industry?) and normative assessment (which justifications are given for the current policies and to what extent do they threaten important academic values?). After illustrating the major rise of academic patenting and licensing in the US and Europe and commenting on the increasing trend of 'upstream' patenting and the focus on exclusive as opposed to non-exclusive licences, this paper will discuss five negative effects of these trends. Subsequently, the question as to why policymakers seem to ignore these adverse effects will be addressed. Finally, a number of proposals for improving university policies will be made
Beam instrumentation for the Tevatron Collider
The Tevatron in Collider Run II (2001-present) is operating with six times
more bunches and many times higher beam intensities and luminosities than in
Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and
the never-ending luminosity upgrade campaign. We present the overall picture of
the Tevatron diagnostics development for Run II, outline machine needs for new
instrumentation, present several notable examples that led to Tevatron
performance improvements, and discuss the lessons for future colliders
Civil society and financial markets : what is not happening and why
Why have commercial financial flows â as a major force in contemporary society with a number of significant problematic consequences â attracted relatively little effective public-interest response from civil society? Change-oriented NGOs, labour unions, faith-based organisations and other social movements have mostly remained in the shadows vis-Ă -vis private financial markets. Impacts from these citizen associations have not gone beyond promoting modest rises in public awareness, certain limited policy shifts, and minor institutional reforms of a few public governance agencies. The reasons for these scant achievements are partly related to capacities and practices in civil society groups, relevant governance agencies, and financial firms. Also important in constraining civil society impacts to reform and transform contemporary financial markets are deeper structural circumstances such as embedded social hierarchies (among countries, classes, etc.), the pivotal role of finance capital in accumulation processes today, and the entrenchment of prevailing neoliberal policy discourses
Influences on academics' approaches to development: voices from below
The purpose of this qualitative case study research was to explore faculty-based academicsâ views on what influences their behaviours and attitudes towards their development. Informed by critical realist ontology, the data collection was carried out through narrative interviews with academics in two contrasting English Universities. Findings, or areas for reflection, have emerged about the constraints and enablements academics perceive in respect of their professional development. In particular, themes such as the significance of professional status; misaligned initiatives and priorities; the influence of supportive networks; and emergent personal, individual concerns have surfaced. The conclusion is drawn that the significance of agency raises the importance of responding to the âvoices from belowâ
Informing the Responses of Water Service Delivery Institutions to Climate and Development Changes: A Case Study in the Amatole Region, Eastern Cape
This report has been generated by the Water Research Commission (WRC) funded project Developing Climate Change Adaptation Measures and Decision-Support System for Selected South African Water Boards (Project No. K5/2018)
TUNNEL GEOLOGY AS SEEN BY GEOLOGISTS: MANHATTAN, NEW YORK CITY
Current exploratory boring operations in and around Manhattan, New York City are providing geologists and geotechnical engineers with a plethora of new and interesting geological information, which has not been previously reported. The rocks encountered, mostly medium to high-grade metamorphic rocks, with both mafic and felsic intrusives, are highly variable in competency and mechanical durability. One of the most frequently encountered rock types is a garnetiferous-muscovite-biotite schist which grades into schistose gneiss and displays a wide variety of structural, compositional, and textural attributes. Metamorphic minerals showing the variable degree of metamorphism include graphite, talc, garnet, kyanite, tourmaline, emory, and occasionally sillimanite. The presence of magnetite-rich zones within the muscovite-garnet schist suggests a mechanism for the concentration of iron during metamorphism. Concentrations of garnet both in the schist and intrusive pegmatite is perhaps indicative of anatectic melting of the protolith. Marble is the dominant rock type east of CAMERON\u27S LINE and it varies from pure white calcitic to dolomitic coarsely crystalline marble, to siliceous calcitic to dolomitic marble. In places, highly pyrite-rich zones, perhaps suggesting hydrothermal alteration of the parent rock due to subsequent mineral-rich fluid flow, are observed. The timing of the sulfide-rich fluid-flow through the original bedrock is yet to be determined. Partial dissolution of marble at various depths has resulted in void (cave) formation and has posed a threat to the boring operations. Rocks of lower abundance include amphibolite, granodiorite, quartzite, serpentinite, and aplite. The overall structural fabric is controlled by the Taconic and Acadian Orogenic events and manifested in the development of characteristic foliation, joint patterns, intrusives, and the degree of metamorphism of the protoliths
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