A comparison of techniques to optimize measurement of voltage changes in electrical impedance tomography by minimizing phase shift errors

In electrical impedance tomography, errors due to stray capacitance may be reduced by optimization of the reference phase of the demodulator. Two possible methods, maximization of the demodulator output and minimization of reciprocity error have been assessed, applied to each electrode combination individually, or to all combinations as a whole. Using an EIT system with a single impedance measuring circuit and multiplexer to address the 16 electrodes, the methods were tested on resistor-capacitor networks, saline-filled tanks and humans during variation of the saline concentration of a constant fluid volume in the stomach. Optimization of each channel individually gave less error, particularly on humans, and maximization of the output of the demodulator was more robust. This method is, therefore, recommended to optimize systems and reduce systematic errors with similar EIT systems

Could psoralen plus ultraviolet A1 (“PUVA1”) work? Depth penetration achieved by phototherapy lamps

Funding: PhD Studentship UK EPRSC EP/N509759/1.Psoralen and ultraviolet A (PUVA) is useful in treating various hand and foot skin diseases.1 Most cases of psoriasis respond well to phototherapy or PUVA. However, for some diseases, such as palmoplantar pustular psoriasis, PUVA is not always sufficient to produce therapeutic effect. If PUVA fails, it is sometimes necessary to progress to other treatments such as Grenz ray therapy (where available),2 systemic retinoid or systemic immunosuppression. Could “PUVA1” (psoralen combined with ultraviolet A1 long wavelength ultraviolet A [UVA]) work in cases where conventional PUVA (psoralen plus broadband UVA) has been inadequate?PostprintPeer reviewe

A virtual collaborative platform to support building information modeling implementation for energy efficiency

There is increased interest in complying with the new regulations and policies associated with the climate change. In particular industries such as the AEC (Architecture, Engineering and Construction) industry seek to find new strategies and practices for facilitating sustainability but also new regulations to improve efficiency at the building level. Institutions and industrial bodies are now in the process of alignment with new legislative stipulations regarding carbon emissions with wider reflection into environment, social and economic models. At building level such strategies refer to decarbonisation and energy efficiency supported with data driven techniques enriched with virtual collaboration and optimization methods. The increased interest of the research community in Building Information Modeling (BIM) has facilitated numerous solutions ranging from digital products, information retrieval, and optimization techniques all aiming at addressing energy optimization and performance gap reduction. In this paper we present how a virtual collaborative system can be efficiently used for implementing BIM based energy optimization for controlling, monitoring buildings and running energy optimization, greatly contributing to creating a BIM construction community with energy practices. The solution described, known as energy-bim.com platform, disseminates energy efficient practices and community engagement and provides support for building managers in implementing energy efficient optimization plans

On the muon neutrino mass

During the runs of the PS 179 experiment at LEAR of CERN, we photographed an event of antiproton-Ne absorption, with a complete pi+ -> mu+ ->e+ chain. From the vertex of the reaction a very slow energy pi+ was emitted. The pi+ decays into a mu+ and subsequently the mu+ decays into a positron. At the first decay vertex a muon neutrino was emitted and at the second decay vertex an electron neutrino and a muon antineutrino. Measuring the pion and muon tracks and applying the momentum and energy conservation and using a classical statistical interval estimator, we obtained an experimental upper limit for the muon neutrino mass: m_nu < 2.2 MeV at a 90% confidence level. A statistical analysis has been performed of the factors contributing to the square value of the neutrino mass limit.Comment: 18 pages, 5 eps figure

Geo-neutrinos: A systematic approach to uncertainties and correlations

Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization of their fluxes is subject, however, to rather large and highly correlated uncertainties. The geochemical covariance of the U, Th and K abundances in various Earth reservoirs induces positive correlations among the associated geo-neutrino fluxes, and between these and the radiogenic heat. Mass-balance constraints in the Bulk Silicate Earth (BSE) tend instead to anti-correlate the radiogenic element abundances in complementary reservoirs. Experimental geo-neutrino observables may be further (anti)correlated by instrumental effects. In this context, we propose a systematic approach to covariance matrices, based on the fact that all the relevant geo-neutrino observables and constraints can be expressed as linear functions of the U, Th and K abundances in the Earth's reservoirs (with relatively well-known coefficients). We briefly discuss here the construction of a tentative "geo-neutrino source model" (GNSM) for the U, Th, and K abundances in the main Earth reservoirs, based on selected geophysical and geochemical data and models (when available), on plausible hypotheses (when possible), and admittedly on arbitrary assumptions (when unavoidable). We use then the GNSM to make predictions about several experiments ("forward approach"), and to show how future data can constrain - a posteriori - the error matrix of the model itself ("backward approach"). The method may provide a useful statistical framework for evaluating the impact and the global consistency of prospective geo-neutrino measurements and Earth models.Comment: 17 pages, including 4 figures. To appear on "Earth, Moon, and Planets," Special Issue on "Neutrino Geophysics," Proceedings of Neutrino Science 2005 (Honolulu, Hawaii, Dec. 2005

The Peculiar Motions of Early-Type Galaxies in Two Distant Regions VI: The Maximum Likelihood Gaussian Algorithm

The EFAR project is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. Here we describe the maximum likelihood algorithm we developed to investigate the correlations between the parameters of the EFAR database. One-, two-, and three-dimensional gaussian models are constructed to determine the mean value and intrinsic spread of the parameters, and the slopes and intrinsic parallel and orthogonal spread of the Mgb'-Mg2, Mg2-sigma, Mgb'-sigma relations, and the Fundamental Plane. In the latter case, the cluster peculiar velocities are also determined. We show that this method is superior to ``canonical'' approaches of least-squares type, which give biased slopes and biased peculiar velocities. We test the algorithm with Monte Carlo simulations of mock EFAR catalogues and derive the systematic and random errors on the estimated parameters. We find that random errors are always dominant. We estimate the influence of systematic errors due to the way clusters were selected and the hard limits and uncertainties in the selection function parameters for the galaxies. We explore the influence of uniform distributions in the Fundamental Plane parameters and the errors. We conclude that the mean peculiar motions of the EFAR clusters can be determined reliably. In particular, the placement of the two EFAR sample regions relative to the Lauer and Postman dipole allows us to strongly constrain the amplitude of the bulk motion in this direction.Comment: 43 pages, 19 figures, accepted for publication in MNRA

Search for very high energy gamma-rays from WIMP annihilations near the Sun with the Milagro Detector

The neutralino, the lightest stable supersymmetric particle, is a strong theoretical candidate for the missing astronomical ``dark matter''. A profusion of such neutralinos can accumulate near the Sun when they lose energy upon scattering and are gravitationally captured. Pair-annihilations of those neutralinos may produce very high energy (VHE, above $100 GeV$) gamma-rays. Milagro is an air shower array which uses the water Cherenkov technique to detect extensive air showers and is capable of observing VHE gamma-rays from the direction of the Sun with an angular resolution of $0.75^{\circ}$. Analysis of Milagro data with an exposure to the Sun of 1165 hours presents the first attempt to detect TeV gamma-rays produced by annihilating neutralinos captured by the Solar system and shows no statistically significant signal. Resulting limits that can be set on gamma-ray flux due to near-Solar neutralino annihilations and on neutralino cross-section are presented

Development of recurrent coastal plume in Lake Michigan observed for first time

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94637/1/eost11132.pd