2,586 research outputs found

    Competition between extinction and enhancement in surface enhanced Raman spectroscopy

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    Conjugated metallic nanoparticles are a promising means to achieve ultrasensitive and multiplexed sensing in intact three-dimensional samples, especially for biological applications, via surface enhanced Raman scattering (SERS). We show that enhancement and extinction are linked and compete in a collection of metallic nanoparticles. Counterintuitively, the Raman signal vanishes when nanoparticles are excited at their plasmon resonance, while increasing nanoparticle concentrations at off-resonance excitation sometimes leads to decreased signal. We develop an effective medium theory that explains both phenomena. Optimal choices of excitation wavelength, individual particle enhancement factor and concentrations are indicated

    Assessing the impacts of climate change on marine fisheries of Karnataka and identifying regime shifts

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    Climate related regime shifts, namely the rapid reorganization of marine ecosystems from one relatively stable state to another, have been reported from several parts of the world, and found responsible for the fluctuations of major fisheries. Time series on ocean-atmosphere parameters together with time series on plankton and/or fish abundance has been extensively used for identifying regime shifts in the oceans from several parts of the globe

    Modularization and Validation of FUN3D as a CREATE-AV Helios Near-Body Solver

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    Under a recent collaborative effort between the US Army Aeroflightdynamics Directorate (AFDD) and NASA Langley, NASA's general unstructured CFD solver, FUN3D, was modularized as a CREATE-AV Helios near-body unstructured grid solver. The strategies adopted in Helios/FUN3D integration effort are described. A validation study of the new capability is performed for rotorcraft cases spanning hover prediction, airloads prediction, coupling with computational structural dynamics, counter-rotating dual-rotor configurations, and free-flight trim. The integration of FUN3D, along with the previously integrated NASA OVERFLOW solver, lays the ground for future interaction opportunities where capabilities of one component could be leveraged with those of others in a relatively seamless fashion within CREATE-AV Helios

    The bane of juvenile fish catches

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    Juvenile fishes are defined as immature fishes that have not yet had the opportunity to replenish the fish population by spawning. The length at which 50% of the fishes of any particular species mature varies among species and is called its Length at First Maturity (Lm). When juveniles are caught in large numbers there is an economic loss as fishermen get very low prices for the small sized young fish as compared to the larger adults

    The Habitable-Zone Planet Finder: A Stabilized Fiber-Fed NIR Spectrograph for the Hobby-Eberly Telescope

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    We present the scientific motivation and conceptual design for the recently funded Habitable-zone Planet Finder (HPF), a stabilized fiber-fed near-infrared (NIR) spectrograph for the 10 meter class Hobby-Eberly Telescope (HET) that will be capable of discovering low mass planets around M dwarfs. The HPF will cover the NIR Y & J bands to enable precise radial velocities to be obtained on mid M dwarfs, and enable the detection of low mass planets around these stars. The conceptual design is comprised of a cryostat cooled to 200K, a dual fiber-feed with a science and calibration fiber, a gold coated mosaic echelle grating, and a Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7μ\mum cutoff. A uranium-neon hollow-cathode lamp is the baseline wavelength calibration source, and we are actively testing laser frequency combs to enable even higher radial velocity precision. We will present the overall instrument system design and integration with the HET, and discuss major system challenges, key choices, and ongoing research and development projects to mitigate risk. We also discuss the ongoing process of target selection for the HPF survey.Comment: 14 pages, 9 figures. To appear in the proceedings of the SPIE 2012 Astronomical Instrumentation and Telescopes conferenc

    Record of stranded whales along Karnataka coast

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    A whale was stranded in the beach of Guijerbettu, Udupi district, Karnataka on 21.12.2001 . The whale was found in live condition. Thelocal person tried to rescue it but was in vain and later it died. The whale was identified as Balaenopteramusculus (Blue whale). Few vertebrae have been collected and preserved in the museum of Mangalore Research Centre of CMFRI for future identification up to the species level. Another whale (genus : Balaenoptera) was stranded in Kota, Udupi district, Karnataka near the shore of Arama temple on 11.08.2004 in decayed condition

    Object-oriented Programming Laws for Annotated Java Programs

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    Object-oriented programming laws have been proposed in the context of languages that are not combined with a behavioral interface specification language (BISL). The strong dependence between source-code and interface specifications may cause a number of difficulties when transforming programs. In this paper we introduce a set of programming laws for object-oriented languages like Java combined with the Java Modeling Language (JML). The set of laws deals with object-oriented features taking into account their specifications. Some laws deal only with features of the specification language. These laws constitute a set of small transformations for the development of more elaborate ones like refactorings
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