4,561 research outputs found
Studies in Lead Absorption and Lead Poisoning
(1) The history, biochemistry and physiology of lead are discussed, and blood lead values of normal healthy individuals with no lead hazard, healthy lead workers, hospital patients not suffering from plumbism with known lead contact, and cases of clinical plumbism are recorded and contrasted. (2) The aetiology, pathology, clinical findings and treatment of plumbism are discussed. (3) Seven cases of clinical plumbism of industrial origin are described. Three individuals showing laboratory evidence of increased lead absorption of industrial origin, associated with ill-defined symptoms, are also recorded. (4) Lead poisoning arising from the drinking of lead-contaminated water, resulting in the death of a woman, is described, together with investigations carried out to detect the cause of the poisoning. (5) A case of severe plumbism following the ingestion of 110 gr. lead acetate for the purpose of criminal abortion is recorded and discussed
Color Graphics in the Service of Light-Source Visualization and Design
In the world of lighting engineering, one of the most active areas of research and industrial application is in the definition of the color rendering properties of light sources. There is a current international standard, and several new methods have been proposed over the last decade. Ordinary consumers are frequently left with little or no knowledge of how to interpret the numerical data produced by any of these systems. This situation has been exacerbated with the advent of LED light sources with widely differing properties. Certain LEDs yield very different results depending on the particular metric in use. We have designed a color graphical system that allows a user to pick a set of (typically) 16 surface color samples, and to be given a realistic comparison of the colors when illuminated by two different light sources, shown on a side-by-side display on a color monitor. This provides a visual analogy to the computations built into the above-mentioned metrics, all of which are based on comparison techniques. This chapter will provide an insight into the design and operation of our lighting computer graphics visualization system. Mention will also be made of similar systems that may be found in the published literature
Artificial Intelligence in Light-Source Design
The advent of light-emitting diode (LED) light sources has led to a new freedom in the design of light-source spectra, and it is now possible to optimise for different source performance parameters, which is the principal aim of the authorsâ work. LEDs and lasers are real or potential light sources, and are inherently monochromatic, that is, narrow-band sources, with typical optical bandwidths in the range 20â40Â nm (nanometres) for LEDs and 1â5Â nm for diode lasers. Mixtures of three or more can be used to produce nominally white light of the type acceptable for general purpose lighting. It is a characteristic of all types of sources that there is a trade-off between good colour properties and high efficiencies, and the methods described here are directed towards an optimum combination of such parameters. This chapter will explain the use of differential evolution (DE) as a highly effective heuristic approach to optimisation, and proceeds to explain the structure and operation of a DE algorithm designed as an optimisation tool for such purposes
The Intermediate Coupling Regime in the AdS/CFT Correspondence
The correspondence between the 't Hooft limit of N=4 super Yang-Mills theory
and tree-level IIB superstring theory on AdS(5)xS(5) in a Ramond-Ramond
background at values of lambda=g^2 N ranging from infinity to zero is examined
in the context of unitarity. A squaring relation for the imaginary part of the
holographic scattering of identical string fields in the two-particle channels
is found, and a mismatch between weak and strong 't Hooft coupling is pointed
out within the correspondence. Several interpretations and implications are
proposed.Comment: 10 pages, LaTeX, reference adde
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Exact low-energy effective actions for hypermultiplets in four dimensions
We consider the general hypermultiplet Low-Energy Effective Action (LEEA)
that may appear in quantized, four-dimensional, N=2 supersymmetric, gauge
theories, e.g. in the Coulomb and Higgs branches. Our main purpose is a
description of the exact LEEA of n magnetically charged hypermultiplets. The
hypermultiplet LEEA is given by the N=2 supersymmetric Non-Linear Sigma-Model
(NLSM) with a 4n-dimensional hyper-K"ahler metric, subject to non-anomalous
symmetries. Harmonic Superspace (HSS) and the NLSM isometries are very useful
to constrain the hyper-K"ahler geometry of the LEEA. We use N=2 supersymmetric
projections of HSS superfields to N=2 linear (tensor) O(2) and O(4) multiplets
in N=2 Projective Superspace (PSS) to deduce the explicit form of the LEEA in
some particular cases. As the by-product, a simple new classification of all
multi-monopole moduli space metrics having su(2)_R symmetry is proposed in
terms of real quartic polynomials of 2n variables, modulo Sp(n)
transformations. The 4d hypermultiplet LEEA for n=2 can be encoded in terms of
an elliptic curve.Comment: 60 pages, LaTeX, macros included, references adde
Simplifying Algebra in Feynman Graphs, Part III: Massive Vectors
A T-dualized selfdual inspired formulation of massive vector fields coupled
to arbitrary matter is generated; subsequently its perturbative series modeling
a spontaneously broken gauge theory is analyzed. The new Feynman rules and
external line factors are chirally minimized in the sense that only one type of
spin index occurs in the rules. Several processes are examined in detail and
the cross-sections formulated in this approach. A double line formulation of
the Lorentz algebra for Feynman diagrams is produced in this formalism, similar
to color ordering, which follows from a spin ordering of the Feynman rules. The
new double line formalism leads to further minimization of gauge invariant
scattering in perturbation theory. The dualized electroweak model is also
generated.Comment: 39 pages, LaTeX, 8 figure
Two-dimensional colloidal fluids exhibiting pattern formation
Fluids with competing short range attraction and long range repulsive
interactions between the particles can exhibit a variety of microphase
separated structures. We develop a lattice-gas (generalised Ising) model and
analyse the phase diagram using Monte Carlo computer simulations and also with
density functional theory (DFT). The DFT predictions for the structures formed
are in good agreement with the results from the simulations, which occur in the
portion of the phase diagram where the theory predicts the uniform fluid to be
linearly unstable. However, the mean-field DFT does not correctly describe the
transitions between the different morphologies, which the simulations show to
be analogous to micelle formation. We determine how the heat capacity varies as
the model parameters are changed. There are peaks in the heat capacity at state
points where the morphology changes occur. We also map the lattice model onto a
continuum DFT that facilitates a simplification of the stability analysis of
the uniform fluid.Comment: 13 pages, 15 figure
SYSTEMS-2: a randomised phase II study of radiotherapy dose escalation for pain control in malignant pleural mesothelioma
SYSTEMS-2 is a randomised study of radiotherapy dose escalation for pain control in 112 patients with malignant pleural mesothelioma (MPM). Standard palliative (20Gy/5#) or dose escalated treatment (36Gy/6#) will be delivered using advanced radiotherapy techniques and pain responses will be compared at week 5. Data will guide optimal palliative radiotherapy in MPM
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