499 research outputs found
An investigation of time efficiency in wavelet-based Markov parameter extraction methods
This paper investigates the time efficiency of using a wavelet transform-based method to extract the impulse response characteristics of a structural dynamic system. Traditional time domain procedures utilize the measured disturbances and response histories of a system to develop a set of auto and cross correlation functions. Through deconvolution of these functions, or matrix inversion, the Markov parameters of the system may be found. By transforming these functions into a wavelet basis, the size of the problem to be solved can be reduced as well as the computation time decreased. Fourier transforms are also used in this capacity as they may increase the time efficiency even more, but at the cost of accuracy. This paper will therefore compare the time requirements associated with a time, wavelet, and Fourier-based method of Markov parameter extraction, as well as their relative accuracy in modeling the system
The significance of sample mass in the analysis of steroid estrogens in sewage sludges and the derivation of partition coefficients in wastewaters
Optimization of an analytical method for determination of steroid estrogens, through minimizing sample size, resulted in recoveries >84%, with relative standard deviations <3% and demonstrated the significance of sample size on method performance. Limits of detection were 2.1–5.3 ng/g. Primary sludges had estrogen concentrations of up to one order of magnitude less than those found in biological sludges (up to 994 ng/g). However, partition coefficients were higher in primary sludges (except estriol), with the most hydrophobic compound (ethinylestradiol) exhibiting the highest Kp value, information which may be of value to those involved in modeling removal during wastewater treatment
Water wave propagation and scattering over topographical bottoms
Here I present a general formulation of water wave propagation and scattering
over topographical bottoms. A simple equation is found and is compared with
existing theories. As an application, the theory is extended to the case of
water waves in a column with many cylindrical steps
The effectiveness of anaerobic digestion in removing estrogens and nonylphenol ethoxylates
This is the post-print version of the final paper published in Journal of Hazardous Materials. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.The fate and behaviour of two groups of endocrine disrupting chemicals, steroid estrogens and nonylphenol ethoxylates, have been evaluated during the anaerobic digestion of primary and mixed sewage sludge under mesophilic and thermophilic conditions. Digestion occurred over six retention times, in laboratory scale reactors, treating sludges collected from a sewage treatment works in the United Kingdom. It has been established that sludge concentrations of both groups of compounds demonstrated temporal variations and that concentrations in mixed sludge were influenced by the presence of waste activated sludge as a result of transformations during aerobic treatment. The biodegradation of total steroid estrogens was >50% during primary sludge digestion with lower removals observed for mixed sludge, which reflected bulk organic solids removal efficiencies. The removal of nonylphenol ethoxylates was greater in mixed sludge digestion (>58%) compared with primary sludge digestion and did not reflect bulk organic removal efficiencies. It is apparent that anaerobic digestion reduces the concentrations of these compounds, and would therefore be expected to confer a degree of protection against exposure and transfer of both groups of compounds to the receiving/re-use environment.Thames Water, Yorkshire Water, and EPSRC
Alpha scattering and capture reactions in the A = 7 system at low energies
Differential cross sections for He- scattering were measured in
the energy range up to 3 MeV. These data together with other available
experimental results for He and H scattering were
analyzed in the framework of the optical model using double-folded potentials.
The optical potentials obtained were used to calculate the astrophysical
S-factors of the capture reactions HeBe and
HLi, and the branching ratios for the transitions into
the two final Be and Li bound states, respectively. For
HeBe excellent agreement between calculated and
experimental data is obtained. For HLi a value
has been found which is a factor of about 1.5 larger than the adopted value.
For both capture reactions a similar branching ratio of has been obtained.Comment: submitted to Phys.Rev.C, 34 pages, figures available from one of the
authors, LaTeX with RevTeX, IK-TUW-Preprint 930540
Crystallographic structure reveals phosphorylated pilin from Neisseria : phosphoserine sites modify type IV pilus surface chemistry and fibre morphology
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72468/1/j.1365-2958.1999.01184.x.pd
Neutrino mass spectrum from the results of neutrino oscillation experiments
All the possible schemes of neutrino mixing with four massive neutrinos
inspired by the existing experimental indications in favor of neutrino mixing
are considered in a model independent way. Assuming that in short-baseline
experiments only one mass-squared difference is relevant, it is shown that the
scheme with a neutrino mass hierarchy is not compatible with the experimental
results. Only two schemes with two pairs of neutrinos with close masses
separated by a mass difference of the order of 1 eV are in agreement with the
results of all experiments. One of these schemes leads to possibly observable
effects in Tritium and neutrinoless double-beta decay experiments.Comment: Latex2e file, 13 pages including 2 figures. Postscript also available
at http://www.to.infn.it/teorici/giunti/papers.htm
Fast Neutron Detection with 6Li-loaded Liquid Scintillator
We report on the development of a fast neutron detector using a liquid
scintillator doped with enriched Li-6. The lithium was introduced in the form
of an aqueous LiCl micro-emulsion with a di-isopropylnaphthalene-based liquid
scintillator. A Li-6 concentration of 0.15 % by weight was obtained. A 125 mL
glass cell was filled with the scintillator and irradiated with fission-source
neutrons. Fast neutrons may produce recoil protons in the scintillator, and
those neutrons that thermalize within the detector volume can be captured on
the Li-6. The energy of the neutron may be determined by the light output from
recoiling protons, and the capture of the delayed thermal neutron reduces
background events. In this paper, we discuss the development of this 6Li-loaded
liquid scintillator, demonstrate the operation of it in a detector, and compare
its efficiency and capture lifetime with Monte Carlo simulations. Data from a
boron-loaded plastic scintillator were acquired for comparison. We also present
a pulse-shape discrimination method for differentiating between electronic and
nuclear recoil events based on the Matusita distance between a normalized
observed waveform and nuclear and electronic recoil template waveforms. The
details of the measurements are discussed along with specifics of the data
analysis and its comparison with the Monte Carlo simulation
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
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