10,980,354 research outputs found
Monte Carlo simulation for radiative kaon decays
For high precision measurements of K decays, the presence of radiated photons
cannot be neglected. The Monte Carlo simulations must include the radiative
corrections in order to compute the correct event counting and efficiency
calculations. In this paper we briefly describe a method for simulating such
decays.Comment: 11 pages, 1 figur
Non-extensive resonant reaction rates in astrophysical plasmas
We study two different physical scenarios of thermonuclear reactions in
stellar plasmas proceeding through a narrow resonance at low energy or through
the low energy wing of a wide resonance at high energy. Correspondingly, we
derive two approximate analytical formulae in order to calculate thermonuclear
resonant reaction rates inside very coupled and non ideal astrophysical plasmas
in which non-extensive effects are likely to arise. Our results are presented
as simple first order corrective factors that generalize the well known
classical rates obtained in the framework of Maxwell-Boltzmann statistical
mechanics. As a possible application of our results, we calculate the
dependence of the total corrective factor with respect to the energy at which
the resonance is located, in an extremely dense and non ideal carbon plasma.Comment: 5 pages, 1 figur
Housing and Homicide
In the 1990s, homicide and violent crime dropped dramatically in New York City but not in Chicago. No single factor can fully explain the reasons for Chicago's persistently high rates of violence. Our data suggest Chicago's homicide rate stayed high while New York City's dropped because of: 1) Continuing disputes over drug markets by Chicago's institutionalized gangs; 2) Police tactics that fractured gang leadership; and 3) Surprisingly, displacement caused by the demolition of public housing Our studies have concluded that a city's housing policy is one crucial component in any effective effort to reduce violence
Metaphoric competence and communicative language ability
Recent developments in cognitive linguistics have highlighted the importance as well as the ubiquity of metaphor in language. Despite this, the ability of second language learners to use metaphors is often still not seen as a core ability. In this paper, we take a model of communicative competence that has been widely influential in both language teaching and language testing, namely Bachman (1990), and argue, giving a range of examples of language use and learner difficulty, that metaphoric competence has in fact an important role to play in all areas of communicative competence. In other words, it can contribute centrally to grammatical competence, textual competence, illocutionary competence, sociolinguistic competence, and strategic competence. Metaphor is thus highly relevant to second language learning, teaching and testing, from the earliest to the most advanced stages of learning
The quality of sustainability and the nature of open source software
The aim is to categorise Open Source Software as a commons based production process and resource. The definition of the commons is always accompanied by the doubt about its sustainability, the so-called "tragedy of the commons." Therefore it is worth to have a closer look on Open Source and why a "tragedy" does not appear
Circular 70
This report describes one aspect of successful air transport
developed over the past 20 years in Alask
CUSTARD (Cranfield University Space Technology Advanced Research Demonstrator) - A Micro-System Technology Demonstrator Nanosatellite. Summary of the Group Design Project MSc in Astronautics and Space Engineering. 1999-2000, Cranfield University
CUSTARD (Cranfield University Space Technology And Research Demonstrator) was
the group design project for students of the MSc in Astronautics and Space
Engineering for the Academic Year 1999/2000 at Cranfield University. The project
involved the initial design of a nanosatellite to be used as a technology
demonstrator for microsystem technology (MST) in space. The students worked
together as one group (organised into several subgroups, e.g. system,
mechanical), with each student responsible for a set of work packages. The
nanosatellite designed had a mass of 4 kg, lifetime of 3 months in low Earth
orbit, coarse 3-axis attitude control (no orbit control), and was capable of
carrying up to 1 kg of payload. The electrical power available was 18 W (peak).
Assuming a single X-band ground station at RAL (UK), a data rate of up to 1 M
bit s-1 for about 3000 s per day is possible. The payloads proposed are a
microgravity laboratory and a formation flying experiment.
The report summarises the results of the project and includes executive
summaries from all team members. Further information and summaries of the full
reports are available from the College of Aeronautics, Cranfield University
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