The Fisher-Rao metric for projective transformations of the line

A conditional probability density function is defined for measurements arising from a projective transformation of the line. The conditional density is a member of a parameterised family of densities in which the parameter takes values in the three dimensional manifold of projective transformations of the line. The Fisher information of the family defines on the manifold a Riemannian metric known as the Fisher-Rao metric. The Fisher-Rao metric has an approximation which is accurate if the variance of the measurement errors is small. It is shown that the manifold of parameter values has a finite volume under the approximating metric. These results are the basis of a simple algorithm for detecting those projective transformations of the line which are compatible with a given set of measurements. The algorithm searches a finite list of representative parameter values for those values compatible with the measurements. Experiments with the algorithm suggest that it can detect a projective transformation of the line even when the correspondences between the components of the measurements in the domain and the range of the projective transformation are unknown

Enhanced vibrational energy harvesting using non-linear stochastic resonance

Stochastic resonance has seen wide application in the physical sciences as a tool to understand weak signal amplification by noise. However, this apparently counter- intuitive phenomenon does not appear to have been exploited as a tool to enhance vibrational energy harvesting. In this note we demonstrate that by adding a periodic excitation to a damped energy harvesting mechanism, the power available from the device is apparently enhanced over a conventional unexcited mechanism. A simple model of such a device is proposed and investigated to explore the use of stochastic resonance to enhance vibrational energy harvesting

Angular Correlations in Top Quark Pair Production and Decay at Hadron Colliders

We show how to observe sizable angular correlations between the decay products of the top quark and those of the anti-top quark in top quark pair production and decay at hadron colliders. These correlations result from the large asymmetry in the rate for producing like-spin versus unlike-spin top quark pairs provided the appropriate spin axes are used. The effects of new physics at production or decay on these correlations are briefly discussed.Comment: 34 pages, revtex, including 12 uuencoded postscript figure

Cosmological parameters from SDSS and WMAP

We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.htm

The Value Addition of Agricultural Waste (Pig dung) in Producing Activated Carbon for Use in Veterinary Medicine, Agriculture and Environmental Remediation: A Review

The expansion of agricultural production has naturally resulted in increased quantities of livestock wastes, agricultural crop residues and agro-industrial by-products. Pig waste is a biomass that changes rapidly from the time of excretion thereby creating a serious pollution problem. The odor from pig dung is capable of diminishing air quality which brings tension and complaints between pig farmers and their neighbors resulting to litigations and risk of possible closure of farms. A review on agricultural wastes such as pig dung is desirable because of their contribution to environmental degradation and the need to convert them to value-added products such as activated carbon (AC). Activated carbon also called activated charcoal is a solid, porous, tasteless and black carbonaceous material prepared from a variety of carbon containing materials, including agricultural wastes. Activated carbon is capable of adsorbing various toxic substances which makes it suitable for use as universal poison antidote, feed additive, water purification, and environmental remediation

'To live and die [for] Dixie': Irish civilians and the Confederate States of America

Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism

Evaluation of thermal comfort in naturally ventilated school classrooms using CFD

This paper investigates the performance and control of natural ventilation during the heating season in order to avoid occupant discomfort. The current study examined different window configurations under a wide range of external temperatures and wind speeds using a CFD simulation tool. The results showed that thermally comfortable indoor conditions could be achieved in a UK classroom when external temperatures are as low as 8°C using high-level openable windows. At lower external temperatures, occupants are predicted to be thermally dissatisfied due to localised discomfort caused by draughts. The results from the CFD model also suggest that acceptable internal thermal conditions can be maintained with wind speeds up to 10m/s, for an external temperature of 10°C. The PMV results indicated that thermal comfort is achieved and is uniformly distributed within the classroom. This work will enable the UK’s Education Funding Agency to have a greater understanding of the effective control of windows to eliminate wintertime discomfort and avoid unnecessary heating for naturally ventilated spaces

Mechanistic Insights into Electrocatalytic Carbon−bromine Bond Cleavage in Polybrominated Phenols

Carbon−halogen bond cleavage has been studied extensively for many years as a simple electrosynthesis step in the formation of more complex natural products. Reduction of halogenated phenols has received less attention, in part, due to the lowered faradaic efficiency resulting from the competing hydrogen evolution reaction. Herein, we report the electroreduction of a series of brominated phenols through a homogeneous electrocatalytic (EC′) mechanism. Beginning with the structurally simple 2-bromophenol, we use foot-of-the-wave analysis to determine optimal catalysts. Nickel (II) salen requires the lowest overpotential for C−Br reduction and was used across all substrates. Chronoamperometric studies and density functional theory calculations were carried out to contribute to our understanding of the reduction mechanism. Next, the more complex 2,6-dibromophenol and tetrabromobisphenol-A are studied by means of cyclic voltammetry, chronoamperometry, and density functional theory. through analysis of molecular orbitals diagrams, the more complex brominated phenols are found to undergo sequential carbon−bromine bond reduction, wherein the electrogenerated radical species accepts a second electron to form a carbanion before second carbon−bromine bond cleavage occurs

'Saving Children 2009' : evaluating quality of care through mortality auditing

No abstract available.http://www.sajch.org.za/index.php/SAJC

An ice-sheet scale comparison of eskers with modelled subglacial drainage routes

Eskers record a time-integrated signature of channelised meltwater drainage during deglaciation providing vital information on the nature and evolution of subglacial drainage. In this paper, we compare the spatial pattern of eskers beneath the former Laurentide Ice Sheet with subglacial drainage routes diagnosed at discrete time intervals from the results of a numerical icesheet model. Perhaps surprisingly, we show that eskers predominantly occur in regions where modelled subglacial water flow is low. Eskers and modelled subglacial drainage routes were found to typically match for lengths <10 km, and most eskers show a better agreement with the routes close to the ice margin just prior to deglaciation. This supports a time-transgressive esker pattern, with formation in short (<10 km) segments of conduit close behind a retreating ice margin, and probably associated with thin, stagnant or sluggish ice. Esker forming conduits were probably dominated by supraglacially fed meltwater inputs. We also show that modelled subglacial drainage routes containing the largest concentrations of meltwater show a close correlation with palaeo-ice stream locations. The paucity of eskers along the terrestrial portion of these palaeo-ice streams and meltwater routes is probably due to the prevalence of distributed drainage and the high erosion potential of fast-flowing ice