506 research outputs found
Water, boundaries and borders, the great intangibles in water quality management: can new technologies enable more effective compliance?
The challenge of improving water quality has been a longstanding global concern. There has also been a general acceptance that the main drivers of poor water quality are economics, poor water management, agricultural practices, and urban development. Development, implementation, and compliance with transboundary water quality agreements, whether they be across basin, across water bodies or across national or international boundaries, remains constrained by our ability to monitor their effectiveness in real time. Despite significant advances in sensor and communication technologies, water quality monitoring (WQM) is primarily undertaken through small-scale and single-application sampling and testing that is limited by the available techniques, requires expensive highly technical instrumentation, and only provides selective data for decision support tools. The effects of diffuse pollutants and their distribution within water bodies and transboundary rivers systems are, therefore, difficult to capture, as is determination of the exact point and timing of their release into a defined “water system”.Improved data capture and timely analysis, enabled by innovative sensor technologies and communication networks, is an important aspect of compliance monitoring. This is particularly important for international and trans-border agreements where changes in water distribution, quality, and availability associated with regional climate variability are already creating challenges for future water, energy, and food security. Therefore, it is argued that by including all the multi-level impacts of various stakeholders in a water catchment, on water resources, and by removing the long lead times between when the sample was taken to when sample testing and data analysis has been completed, it is possible to develop and implement an effective water quality monitoring and management framework.This paper examines the prospect of improved sensor technologies and assessment frameworks that have the potential to be linked with water quality governance, polices and compliance requirements. By employing, a real time integrated and targeted monitoring system, which allows for the assessment of both the catchment functions and modifications to those functions or (eco) services by the various stakeholders, improvements in water quality is possible
Canonical differential geometry of string backgrounds
String backgrounds and D-branes do not possess the structure of Lorentzian
manifolds, but that of manifolds with area metric. Area metric geometry is a
true generalization of metric geometry, which in particular may accommodate a
B-field. While an area metric does not determine a connection, we identify the
appropriate differential geometric structure which is of relevance for the
minimal surface equation in such a generalized geometry. In particular the
notion of a derivative action of areas on areas emerges naturally. Area metric
geometry provides new tools in differential geometry, which promise to play a
role in the description of gravitational dynamics on D-branes.Comment: 20 pages, no figures, improved journal versio
Rearranging Edgeworth-Cornish-Fisher Expansions
This paper applies a regularization procedure called increasing rearrangement
to monotonize Edgeworth and Cornish-Fisher expansions and any other related
approximations of distribution and quantile functions of sample statistics.
Besides satisfying the logical monotonicity, required of distribution and
quantile functions, the procedure often delivers strikingly better
approximations to the distribution and quantile functions of the sample mean
than the original Edgeworth-Cornish-Fisher expansions.Comment: 17 pages, 3 figure
Theory of a Higher Order Phase Transition: Superconducting Transition in BKBO
We describe here the properties expected of a higher (with emphasis on the
order fourth) order phase transition. The order is identified in the sense
first noted by Ehrenfest, namely in terms of the temperature dependence of the
ordered state free energy near the phase boundary. We have derived an equation
for the phase boundary in terms of the discontinuities in thermodynamic
observables, developed a Ginzburg-Landau free energy and studied the
thermodynamic and magnetic properties. We also discuss the current status of
experiments on and other based superconductors,
the expectations for parameters and examine alternative explanations of the
experimental results.Comment: 18 pages, no figure
Fertility, Living Arrangements, Care and Mobility
There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century – demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
The WWgamma triple gauge boson coupling parameters are studied using p-pbar
-> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were
collected with the DO detector from an integrated luminosity of 162 pb^{-1}
delivered by the Fermilab Tevatron Collider. The cross section times branching
fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV
and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum)
pb. The one-dimensional 95% confidence level limits on anomalous couplings are
-0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging
We present a measurement of the top quark pair () production cross
section () in collisions at TeV
using 230 pb of data collected by the D0 experiment at the Fermilab
Tevatron Collider. We select events with one charged lepton (electron or muon),
missing transverse energy, and jets in the final state. We employ
lifetime-based b-jet identification techniques to further enhance the
purity of the selected sample. For a top quark mass of 175 GeV, we
measure pb, in
agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let
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