Cryogenic Insulation System

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system

Towards an institutional PLE

PLEs in their broader sense (the ad-hoc, serendipitous and potentially chaotic set of tools that learners bring to their learning) are increasingly important for learners in the context of formal study. In this paper we outline the approach that we are taking at the University of Southampton in redesigning our teaching and learning infrastructure into an Institutional PLE. We do not see this term as an oxymoron. We define an Institutional PLE as an environment that provides a personalised interface to University data and services and at the same time exposes that data and services to a student’s personal tools. Our goal is to provide a digital platform that can cope with an evolving learning and teaching environment, as well as support the social and community aspects of the institution

Cryogenic mechanisms for scanning and interchange of the Fabry-Perot interferometers in the ISO long wavelength spectrometer

The Infrared Space Observatory (ISO) is an ESA cornerstone mission for infrared astronomy. Schedules for launch in 1993, its four scientific instruments will provide unprecedented sensitivity and spectral resolution at wavelengths which are inaccessible using ground-based techniques. One of these, the Long Wavelength Spectrometer (LWS), will operate in the 45 to 180 micron region (Emery et. al., 1985) and features two Fabry-Perot interferometers mounted on an interchange mechanism. The entire payload module of the spacecraft, comprising the 60 cm telescope and the four focal plane instruments, is maintained at 2 to 4 K by an onboard supply of liquid helium. The mechanical design and testing of the cryogenic interferometer and interchange mechanisms are described

Impact of the abolition of EU Milk quotas on Agriculture in the UK

In recent years the CAP has undergone significant reforms, but the dairy sector has largely avoided wholesale changes. The sector, however, is now faced with a significant effort by the Commission to instigate reform. In this study the FAPRI-UK modelling system is simulated to identify the impact of abolishing or phasing out EU milk quotas on the dairy sector in the UK and the results are compared against a 2007 Baseline projection (2007--2016). The results demonstrate that although the impact of the abolition of dairy quotas is fairly modest at the EU-25 level, significant impacts are apparent at the individual country level.Milk Quotas, CAP Reform, Commodity Modelling, Agricultural and Food Policy, International Relations/Trade, Livestock Production/Industries,

Primordial magnetic field and spectral distortion of cosmic background radiation

The role played by a primordial magnetic field during the pre-recombination epoch is analysed through the cyclotron radiation (due to the free electrons) it might produce in the primordial plasma. We discuss the constraint implied by the measurement or lack thereof COBE on this primordial field.Comment: to appear in International Journal of Mod. Phy

The C-Band All-Sky Survey: Instrument design, status, and first-look data

The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.Comment: 10 pages, 11 figures, published in Proceedings of SPIE MIllimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (2010), Vol. 7741, 77411I-1 - 77411I-1

Surrogate Light Chain Expressing Human Peripheral B Cells Produce Self-reactive Antibodies

Human B cells that coexpress surrogate and conventional light chains (V-preB+L+) show an unusual heavy and light chain antibody repertoire that display evidence of receptor editing. However, it is unclear whether V-preB+L+ B cells have been silenced by receptor editing or still express autoreactive antibodies. Here we report that 68% of the antibodies expressed by V-preB+L+ B cells are autoreactive. A majority of these autoantibodies are true antinuclear antibodies (ANA), and 50% of the ANAs are also reactive with a diverse group of antigens that include dsDNA, ssDNA, immunoglobulin, insulin, and bacterial lipopolysaccharide. Such antibodies are rarely encountered among conventional B cells. We conclude that V-preB+L+ B cells are a unique subset of normal circulating human B cells that escape central tolerance mechanisms and express self-reactive antibodies including potentially harmful ANAs

Random Walks for Spike-Timing Dependent Plasticity

Random walk methods are used to calculate the moments of negative image equilibrium distributions in synaptic weight dynamics governed by spike-timing dependent plasticity (STDP). The neural architecture of the model is based on the electrosensory lateral line lobe (ELL) of mormyrid electric fish, which forms a negative image of the reafferent signal from the fish's own electric discharge to optimize detection of sensory electric fields. Of particular behavioral importance to the fish is the variance of the equilibrium postsynaptic potential in the presence of noise, which is determined by the variance of the equilibrium weight distribution. Recurrence relations are derived for the moments of the equilibrium weight distribution, for arbitrary postsynaptic potential functions and arbitrary learning rules. For the case of homogeneous network parameters, explicit closed form solutions are developed for the covariances of the synaptic weight and postsynaptic potential distributions.Comment: 18 pages, 8 figures, 15 subfigures; uses revtex4, subfigure, amsmat