“Smart” Foams for Active Absorption of Sound (written version)

A porous layer can absorb a significant amount of acoustic energy only if its thickness is comparable to the wavelength of the incident sound. Thus a porous layer inevitably becomes a less effective sound absorber as the frequency is decreased. In this paper, it will be shown through theoretical calculations that the low frequency performance of a finite-depth layer of elastic porous material may be enhanced by applying an appropriate force to the solid phase at the front surface of the layer. In particular, it will be shown that at any angle of incidence the solid phase may be forced so as to create a perfect impedance match with an incident plane wave, thus causing the sound to be completely absorbed. Note that the success of the approach suggested here requires a significant degree of coupling between the motion of the solid and fluid phases of the porous material. Thus, it may be expected that partially reticulated, polyurethane foams will be susceptible to this approach owing to the degree of viscous and inertial coupling between their fluid and solid phases

A Wavelet Analysis of Pliopleistocene Climate Indicators: A New View of Periodicity Evolution

Wavelet analysis offers an alternative to Fourier based time-series analysis, and is particularly useful when the amplitudes and periods of dominant cycles are time dependent. We analyse climatic records derived from oxygen isotopic ratios of marine sediment cores with modified Morlet wavelets. We use a normalization of the Morlet wavelets which allows direct correspondence with Fourier analysis. This provides a direct view of the oscillations at various frequencies, and illustrates the nature of the time-dependence of the dominant cycles

Reactive Fluid Flow and Applications to Diagenesis, Mineral Deposits, and Crustal Rocks

The objective is to initiate new: modeling of coupled fluid flow and chemical reactions of geologic environments; experimental and theoretical studies of water-rock reactions; collection and interpretation of stable isotopic and geochemical field data at many spatial scales of systems involving fluid flow and reaction in environments ranging from soils to metamorphic rocks. Theoretical modeling of coupled fluid flow and chemical reactions, involving kinetics, has been employed to understand the differences between equilibrium, steady-state, and non-steady-state behavior of the chemical evolution of open fluid-rock systems. The numerical codes developed in this project treat multi-component, finite-rate reactions combined with advective and dispersive transport in multi-dimensions. The codes incorporate heat, mass, and isotopic transfer in both porous and fractured media. Experimental work has obtained the kinetic rate laws of pertinent silicate-water reactions and the rates of Sr release during chemical weathering. Ab-initio quantum mechanical techniques have been applied to obtain the kinetics and mechanisms of silicate surface reactions and isotopic exchange between water and dissolved species. Geochemical field-based studies were carried out on the Wepawaug metamorphic schist, on the Irish base-metal sediment-hosted ore system, in the Dalradian metamorphic complex in Scotland, and on weathering in the Columbia River flood basalts. The geochemical and isotopic field data, and the experimental and theoretical rate data, were used as constraints on the numerical models and to determine the length and time scales relevant to each of the field areas

A Search for Radio Gravitational Lenses, Using the Sloan Digital Sky Survey and the Very Large Array

We report on a novel search for radio gravitational lenses. Using the Very Large Array, we imaged ten candidates with both dual redshifts in Sloan Digital Sky Survey spectra and 1.4 GHz radio flux >2 mJy in the FIRST survey. The VLA maps show that in each case the radio emission is associated with the foreground galaxy rather than being lensed emission from the background galaxy, although at least four of our targets are strong lenses at optical wavelengths. These SDSS dual-redshift systems do not have lensed radio emission at the sensitivity of current radio surveys.Comment: 7 pages, 10 figures, uses emulateapj. Accepted to ApJ (11/25/2005). v2: Minor changes in accepted versio

International Chemical Congresses.

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Djinn Lite: a tool for customised gene transcript modelling, annotation-data enrichment and exploration

BACKGROUND: There is an ever increasing rate of data made available on genetic variation, transcriptomes and proteomes. Similarly, a growing variety of bioinformatic programs are becoming available from many diverse sources, designed to identify a myriad of sequence patterns considered to have potential biological importance within inter-genic regions, genes, transcripts, and proteins. However, biologists require easy to use, uncomplicated tools to integrate this information, visualise and print gene annotations. Integrating this information usually requires considerable informatics skills, and comprehensive knowledge of the data format to make full use of this information. Tools are needed to explore gene model variants by allowing users the ability to create alternative transcript models using novel combinations of exons not necessarily represented in current database deposits of mRNA/cDNA sequences. RESULTS: Djinn Lite is designed to be an intuitive program for storing and visually exploring of custom annotations relating to a eukaryotic gene sequence and its modelled gene products. In particular, it is helpful in developing hypothesis regarding alternate splicing of transcripts by allowing the construction of model transcripts and inspection of their resulting translations. It facilitates the ability to view a gene and its gene products in one synchronised graphical view, allowing one to drill down into sequence related data. Colour highlighting of selected sequences and added annotations further supports exploration, visualisation of sequence regions and motifs known or predicted to be biologically significant. CONCLUSION: Gene annotating remains an ongoing and challengingtask that will continue as gene structures, gene transcription repertoires, disease loci, protein products and their interactions become moreprecisely defined. Djinn Lite offers an accessible interface to help accumulate, enrich, and individualise sequence annotations relating to a gene, its transcripts and translations. The mechanism of transcript definition and creation, and subsequent navigation and exploration of features, are very intuitive and demand only a short learning curve. Ultimately, Djinn Lite can form the basis for providing valuable clues to plan new experiments, providing storage of sequences and annotations for dedication to customised projects. The application is appropriate for Windows 98-ME-2000-XP-2003 operating systems

New Ohio and Indiana Records of Aquatic Insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera: Elmidae, Diptera: Chironomidae)

New state records and additional locations for rarely collected species are reported for Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies), Coleoptera: Elmidae (riffle beetles), and Diptera: Chironomidae (chironomids, non-biting midges, midges). These specimen records result primarily from Ohio Environmental Protection Agency biomonitoring of Ohio streams and from records found in the Purdue University Entomological Research Collection and the Illinois Natural History Survey Insect Collection; a few records were derived from material housed in two other collections. New state records for Ohio consist of the mayflies Acentrella rallatoma Burian & Myers, Acerpenna pygmaea (Hagen), Anafroptilum album (McDunnough), Anafroptilum minor group species 1, Anafroptilum minor group species 2, Anafroptilum victoriae (McDunnough), Heterocloeon (Jubilatum) species B McCafferty et al., Heterocloeon (Jubilatum) species D McCafferty et al., Labiobaetis longipalpus (Morihara & McCafferty), Plauditus punctiventris (McDunnough), Ephemera guttulata Pictet, Habrophlebia vibrans Needham, and Anthopotamus verticis (Say); the stonefly Isoperla frisoni Illies; the caddisflies Brachycentrus nigrosoma (Banks), Homoplectra doringa (Milne), Ceraclea nepha (Ross), and Fabria inornata (Banks); the riffle beetle Oulimnius nitidulus (LeConte); and the chironomids Cricotopus (Isocladius) sp. “Ozarks” Epler, Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther. A previous report of the mayfly Macdunnoa persimplex (McDunnough) from the Ohio River, adjacent to Ohio, is substantiated with record data. The caddisfly Goerita betteni Ross is confirmed in Ohio. New state records for Indiana consist of the mayflies Heterocloeon (Jubilatum) species D McCafferty et al. and Leucrocuta walshi (McDunnough) and the chironomids Cricotopus (Isocladius) sp. “Ozarks” and Fittkauimyia sp. [probably F. serta (Roback)]. Recent Indiana records of the mayflies Homoeoneuria ammophila (Spieth) and Pentagenia vittigera (Walsh) are also included because these species are rarely collected and most existing records are old. These records represent significant range extensions north for Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther

The Multi-Object, Fiber-Fed Spectrographs for SDSS and the Baryon Oscillation Spectroscopic Survey

We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999 on the 2.5-m aperture Sloan Telescope at Apache Point Observatory, the spectrographs produced more than 1.5 million spectra for the SDSS and SDSS-II surveys, enabling a wide variety of Galactic and extra-galactic science including the first observation of baryon acoustic oscillations in 2005. The spectrographs were upgraded in 2009 and are currently in use for BOSS, the flagship survey of the third-generation SDSS-III project. BOSS will measure redshifts of 1.35 million massive galaxies to redshift 0.7 and Lyman-alpha absorption of 160,000 high redshift quasars over 10,000 square degrees of sky, making percent level measurements of the absolute cosmic distance scale of the Universe and placing tight constraints on the equation of state of dark energy. The twin multi-object fiber spectrographs utilize a simple optical layout with reflective collimators, gratings, all-refractive cameras, and state-of-the-art CCD detectors to produce hundreds of spectra simultaneously in two channels over a bandpass covering the near ultraviolet to the near infrared, with a resolving power R = \lambda/FWHM ~ 2000. Building on proven heritage, the spectrographs were upgraded for BOSS with volume-phase holographic gratings and modern CCD detectors, improving the peak throughput by nearly a factor of two, extending the bandpass to cover 360 < \lambda < 1000 nm, and increasing the number of fibers from 640 to 1000 per exposure. In this paper we describe the original SDSS spectrograph design and the upgrades implemented for BOSS, and document the predicted and measured performances.Comment: 43 pages, 42 figures, revised according to referee report and accepted by AJ. Provides background for the instrument responsible for SDSS and BOSS spectra. 4th in a series of survey technical papers released in Summer 2012, including arXiv:1207.7137 (DR9), arXiv:1207.7326 (Spectral Classification), and arXiv:1208.0022 (BOSS Overview