31 research outputs found

    Composites with encapsulated structures and related method

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    Chaotic advection causes the formation of various encapsulates in binary phase composites. Such composites are successfully formed with thermoplastics that are present in desired amounts by weight or volume. With a batch type chaotic mixer, the process starts with selecting suitable polymers, mechanically mixing the raw material, heating the mixture, instilling chaotic advection by agitation for a period of time and cooling and recovering the composite. With continuous flow types of chaotic mixers, the process starts with melting the component polymers in separate extruders capable of component melt flows in predetermined proportions

    In defense of commitment: The curative power of violated expectations in relationships.

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    A new model of commitment defense in romantic relationships is proposed. It assumes that relationships afford a central resource for affirming meaning and purpose in the world. Consequently, violating expectations about the world outside the relationship can precipitate commitment defense inside the relationship. A meta-analysis of 5 experiments, 2 follow-up correlational studies, and a longitudinal study of the transition to first parenthood supported the model. Experimentally violating conventional expectations about the world (e.g., “hard work pays off”) motivated less satisfied people to defensively affirm their commitment. Similarly, when becoming a parent naturalistically violated culturally conditioned gendered expectations about the division of household labor, less satisfied new mothers and fathers defensively affirmed their commitment from pre-to-post baby. The findings suggest that violating expected associations in the world outside the relationship motivates vulnerable people to set relationship their relationship right, thereby affirming expected associations in the relationship in the face of an unexpected world

    WISE/NEOWISE Observations of the Jovian Trojans: Preliminary Results

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    We present the preliminary analysis of over 1739 known and 349 candidate Jovian Trojans observed by the NEOWISE component of the Wide-field Infrared Survey Explorer (WISE). With this survey the available diameters, albedos and beaming parameters for the Jovian Trojans have been increased by more than an order of magnitude compared to previous surveys. We find that the Jovian Trojan population is very homogenous for sizes larger than 10\sim10km (close to the detection limit of WISE for these objects). The observed sample consists almost exclusively of low albedo objects, having a mean albedo value of 0.07±0.030.07\pm0.03. The beaming parameter was also derived for a large fraction of the observed sample, and it is also very homogenous with an observed mean value of 0.88±0.130.88\pm0.13. Preliminary debiasing of the survey shows our observed sample is consistent with the leading cloud containing more objects than the trailing cloud. We estimate the fraction to be N(leading)/N(trailing) 1.4±0.2\sim 1.4 \pm 0.2, lower than the 1.6±0.11.6 \pm 0.1 value derived by others.Comment: Accepted for publication in Astrophysical Journal. Electronic table will be available at the publishers websit

    Main Belt Asteroids with WISE/NEOWISE I: Preliminary Albedos and Diameters

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    We present initial results from the Wide-field Infrared Survey Explorer (WISE), a four-band all-sky thermal infrared survey that produces data well suited to measuring the physical properties of asteroids, and the NEOWISE enhancement to the WISE mission allowing for detailed study of Solar system objects. Using a NEATM thermal model fitting routine we compute diameters for over 100,000 Main Belt asteroids from their IR thermal flux, with errors better than 10%. We then incorporate literature values of visible measurements (in the form of the H absolute magnitude) to determine albedos. Using these data we investigate the albedo and diameter distributions of the Main Belt. As observed previously, we find a change in the average albedo when comparing the inner, middle, and outer portions of the Main Belt. We also confirm that the albedo distribution of each region is strongly bimodal. We observe groupings of objects with similar albedos in regions of the Main Belt associated with dynamical breakup families. Asteroid families typically show a characteristic albedo for all members, but there are notable exceptions to this. This paper is the first look at the Main Belt asteroids in the WISE data, and only represents the preliminary, observed raw size and albedo distributions for the populations considered. These distributions are subject to survey biases inherent to the NEOWISE dataset and cannot yet be interpreted as describing the true populations; the debiased size and albedo distributions will be the subject of the next paper in this series.Comment: Accepted to ApJ. Online table to also appear on the publisher's websit

    NEOWISE Observations of Near-Earth Objects: Preliminary Results

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    With the NEOWISE portion of the \emph{Wide-field Infrared Survey Explorer} (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 μ\mum, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether they were previously known or not, subject to the availability of ground-based follow-up observations, resulting in the discovery of more than 130 new NEOs. The survey's uniformity in sensitivity, observing cadence, and image quality have permitted extrapolation of the 428 near-Earth asteroids (NEAs) detected by NEOWISE during the fully cryogenic portion of the WISE mission to the larger population. We find that there are 981±\pm19 NEAs larger than 1 km and 20,500±\pm3000 NEAs larger than 100 m. We show that the Spaceguard goal of detecting 90% of all 1 km NEAs has been met, and that the cumulative size distribution is best represented by a broken power law with a slope of 1.32±\pm0.14 below 1.5 km. This power law slope produces 13,200±\sim13,200\pm1,900 NEAs with D>D>140 m. Although previous studies predict another break in the cumulative size distribution below DD\sim50-100 m, resulting in an increase in the number of NEOs in this size range and smaller, we did not detect enough objects to comment on this increase. The overall number for the NEA population between 100-1000 m are lower than previous estimates. The numbers of near-Earth comets will be the subject of future work.Comment: Accepted to Ap

    WISE/NEOWISE observations of Active Bodies in the Main Belt

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    We report results based on mid-infrared photometry of 5 active main belt objects (AMBOs) detected by the Wide-field Infrared Survey Explorer (WISE) spacecraft. Four of these bodies, P/2010 R2 (La Sagra), 133P/Elst-Pizarro, (596) Scheila, and 176P/LINEAR, showed no signs of activity at the time of the observations, allowing the WISE detections to place firm constraints on their diameters and albedos. Geometric albedos were in the range of a few percent, and on the order of other measured comet nuclei. P/2010 A2 was observed on April 2-3, 2010, three months after its peak activity. Photometry of the coma at 12 and 22 {\mu}m combined with ground-based visible-wavelength measurements provides constraints on the dust particle mass distribution (PMD), dlogn/dlogm, yielding power-law slope values of {\alpha} = -0.5 +/- 0.1. This PMD is considerably more shallow than that found for other comets, in particular inbound particle fluence during the Stardust encounter of comet 81P/Wild 2. It is similar to the PMD seen for 9P/Tempel 1 in the immediate aftermath of the Deep Impact experiment. Upper limits for CO2 & CO production are also provided for each AMBO and compared with revised production numbers for WISE observations of 103P/Hartley 2.Comment: 32 Pages, including 5 Figure

    WISE/NEOWISE Observations of the Hilda Population: Preliminary Results

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    We present the preliminary analysis of 1023 known asteroids in the Hilda region of the Solar System observed by the NEOWISE component of the Wide-field Infrared Survey Explorer (WISE). The sizes of the Hildas observed range from 3200\sim 3 - 200km. We find no size - albedo dependency as reported by other projects. The albedos of our sample are low, with a weighted mean value pV=0.055±0.018p_V = 0.055\pm0.018, for all sizes sampled by the NEOWISE survey. We observed a significant fraction of the objects in the two known collisional families in the Hilda population. It is found that the Hilda collisional family is brighter, with weighted mean albedo of pV=0.061±0.011p_V = 0.061\pm0.011, than the general population and dominated by D-type asteroids, while the Schubart collisional family is darker, with weighted mean albedo of (pV=0.039±0.013p_V = 0.039\pm0.013). Using the reflected sunlight in the two shortest WISE bandpasses we are able to derive a method for taxonomic classification of 10\sim 10% of the Hildas detected in the NEOWISE survey. For the Hildas with diameter larger than 30km there are 6715+767^{+7}_{-15}% D-type asteroids and 265+1726^{+17}_{-5}% C-/P-type asteroids (with the majority of these being P-types).Comment: Accepted for publication in Astrophysical Journal. Electronic table to be published on the publishers websit

    Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

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    The \emph{Wide-field Infrared Survey Explorer} has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the \emph{Infrared Astronomical Satellite} and the \emph{Cosmic Background Explorer}. NASA's Planetary Science Division has funded an enhancement to the \WISE\ data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the \WISE\ data. NEOWISE has mined the \WISE\ images for a wide array of small bodies in our Solar System, including Near-Earth Objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in February 2011, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and \sim120 comets. The NEOWISE dataset will enable a panoply of new scientific investigations.Comment: ApJ accepte
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