5,156 research outputs found

    Flexible seal for valves Patent

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    Flexible inflatable seal for butterfly valve

    Preliminary Design Study of a Hybrid Airship for Flight Research

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    The feasibility of using components from four small helicopters and an airship envelope as the basis for a quad-rotor research aircraft was studied. Preliminary investigations included a review of candidate hardware and various combinations of rotor craft/airship configurations. A selected vehicle was analyzed to assess its structural and performance characteristics

    Preliminary study of ground handling characteristics of Buoyant Quad Rotor (BQR) vehicles

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    A preliminary investigation of mooring concepts appropriate for heavy lift buoyant quad rotor (BQR) vehicles was performed. A review of the evolution of ground handling systems and procedures for all airship types is presented to ensure that appropriate consideration is given to past experiences. Two buoyant quad rotor designs are identified and described. An analysis of wind loads on a moored airship and the effects of these loads on vehicle design is provided. Four mooring concepts are assessed with respect to the airship design, wind loads and mooring site considerations. Basing requirements and applicability of expeditionary mooring at various operational scenarios are addressed

    Incorporating Poly(3-hexyl thiophene) into Orthogonally Aligned Cylindrical Nanopores of Titania for Optoelectronics

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    The incorporation of hole conducting polymer poly(3-hexyl thiophene) (P3HT) into the 8-9 nm cylindrical nanopores of titania is investigated using films with a unique orthogonally oriented hexagonal close packed mesostructure. The films are synthesized using evaporation induced self-assembly (EISA) with Pluronic triblock copolymer F127 as the structure directing agent. The orthogonally oriented cylindrical nanopore structure was chosen over a cubic structure because confinement in uniform cylindrical channels is hypothesized to enhance hole conductivity of P3HT by inducing local polymer chain ordering. Orthogonal orientation of the cylindrical nanopores is achieved by modifying the substrate (FTO-coated glass slides) with crosslinked F127. After thermal treatment to remove organic templates from the films, P3HT is infiltrated into the nanopores by spin coating a 1 wt% P3HT solution in chlorobenzene onto the titania films followed by thermal annealing under vacuum at 200 °C. The results show that infiltration is essentially complete after 30 minutes of annealing, with little or no further infiltration thereafter. A final infiltration depth of ~14 nm is measured for P3HT into the nanopores of titania using neutron reflectometry measurements. Photoluminescence measurements demonstrate that charge transfer at the P3HT-TiO2 interface improves as the P3HT is infiltrated into the pores, suggesting that an active organic-inorganic heterojuction is formed in the materials

    Predicting animal behaviour using deep learning: GPS data alone accurately predict diving in seabirds

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    1.:To prevent further global declines in biodiversity, identifying and understanding key habitats is crucial for successful conservation strategies. For example, globally, seabird populations are under threat and animal movement data can identify key at‐sea areas and provide valuable information on the state of marine ecosystems. To date, in order to locate these areas, studies have used global positioning system (GPS) to record position and are sometimes combined with time–depth recorder (TDR) devices to identify diving activity associated with foraging, a crucial aspect of at‐sea behaviour. However, the use of additional devices such as TDRs can be expensive, logistically difficult and may adversely affect the animal. Alternatively, behaviours may be resolved from measurements derived from the movement data alone. However, this behavioural analysis frequently lacks validation data for locations predicted as foraging (or other behaviours). 2.: Here, we address these issues using a combined GPS and TDR dataset from 108 individuals by training deep learning models to predict diving in European shags, common guillemots and razorbills. We validate our predictions using withheld data, producing quantitative assessment of predictive accuracy. The variables used to train these models are those recorded solely by the GPS device: variation in longitude and latitude, altitude and coverage ratio (proportion of possible fixes acquired within a set window of time). 3.: Different combinations of these variables were used to explore the qualities of different models, with the optimum models for all species predicting non‐diving and diving behaviour correctly over 94% and 80% of the time, respectively. We also demonstrate the superior predictive ability of these supervised deep learning models over other commonly used behavioural prediction methods such as hidden Markov models. 4.: Mapping these predictions provides useful insights into the foraging activity of a range of seabird species, highlighting important at sea locations. These models have the potential to be used to analyse historic GPS datasets and further our understanding of how environmental changes have affected these seabirds over time

    Chromospheric Variability in SDSS M Dwarfs. II. Short-Timescale H-alpha Variability

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    [Abridged] We present the first comprehensive study of short-timescale chromospheric H-alpha variability in M dwarfs using the individual 15 min spectroscopic exposures for 52,392 objects from the Sloan Digital Sky Survey. Our sample contains about 10^3-10^4 objects per spectral type bin in the range M0-M9, with a total of about 206,000 spectra and a typical number of 3 exposures per object (ranging up to a maximum of 30 exposures). Using this extensive data set we find that about 16% of the sources exhibit H-alpha emission in at least one exposure, and of those about 45% exhibit H-alpha emission in all of the available exposures. Within the sample of objects with H-alpha emission, only 26% are consistent with non-variable emission, independent of spectral type. The H-alpha variability, quantified in terms of the ratio of maximum to minimum H-alpha equivalent width (R_EW), and the ratio of the standard deviation to the mean (sigma_EW/), exhibits a rapid rise from M0 to M5, followed by a plateau and a possible decline in M9 objects. In particular, R_EW increases from a median value of about 1.8 for M0-M3 to about 2.5 for M7-M9, and variability with R_EW>10 is only observed in objects later than M5. For the combined sample we find that the R_EW values follow an exponential distribution with N(R_EW) exp[-(R_EW-1)/2]; for M5-M9 objects the characteristic scale is R_EW-1\approx 2.7, indicative of stronger variability. In addition, we find that objects with persistent H-alpha emission exhibit smaller values of R_EW than those with intermittent H-alpha emission. Based on these results we conclude that H-alpha variability in M dwarfs on timescales of 15 min to 1 hr increases with later spectral type, and that the variability is larger for intermittent sources.Comment: Submitted to ApJ; 20 pages, 15 figure

    Estimate of the Probability and Consequences of Ignition of the HRT Charcoal Beds

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    BS>The igition temperature of Columbia G activated charcoal in a flowing oxygen stream was determined to be 290 deg C under conditions simulating the inlet of the HRT charcoal beds. Calculations of charcoal temperatures resulting from beta decay of adsorbed fission gases from the HRT indicate that this temperature will not be reached provided the reacter power does not exceed 10 Mw with an accompanying oxygen flow not exceeding 2 liters/min. At lower power levels higher oxygen flow may be tolerated. If, by a combination of circumstances, ignition of the charcoal should occur, it will be possible to extinguish the fire by stopping the oxygen flow. The down-stream propagation of the combustion front is slow enough to allow detection and corrective action to be taken before a serious situation occurs. (auth

    Estimate of Hazard Produced by Accidental Release of Gaseous Fission Products from an ORR Fused Salt Capsule Experiment

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    An accidental release of gaseous fission products from an ORR fused salt capsule, containing 26 mg. of U/sup 235/, was postulated and the resuiting hazard estimated by calculating the maximum external and internal dose an individual could receive from exposure to the gaseous fission products and their decay products. Assuming all the contained gaseous fission produets are released, the resulting external and internal dosc, to organs other than the thyroid, arc insignificant. The dose to the thyroid by radioiodine is considered to be significant. By retaining at least 90% of the iodine isotopes in the experiment system through use of an iodine trap, a large reduction in both the external whole body and internal thyroid doses may be achieved. Therefore, assuming an iodine trap is utilized, it appears that the consequences of am accidental gaseous fission product release from an ORR fused salt capsule experiment would not be serious. (auth

    About Those New Oats - Burnett and Newton

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    These two new oat varieties will be available for planting in 1958. You can see them growing this year at Iowa State College or in the fields of certified seed producers. Here are the details on what you can expect
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