97,179 research outputs found

    Mariner 9 control net of Mars, April 1973

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    A planet-wide geodetic control net of Mars that is based on the Mariner 9 television pictures has been in the process of being computed since January 1972. Results of the computations as of April 1973 are presented. Areocentric and areographic coordinates of 1340 control points have been computed using 613 frames and are presented tabularly. These coordinates will be revised as additional points and frames are added to the computation in the future

    First Record of \u3ci\u3eAphis Helianthi\u3c/i\u3e (Homoptera: Aphididae) as a Pest of Celery

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    In 1989, the aphid Aphis helianthi severely damaged five of 10 scouted celery fields in west central Michigan. In 1990 and in 1991, A. helianthi again was a problem. reaching pestiferous levels in three of 10 and two of 10 scouted fields. respectively. This insect has not been reported previously as a pest of celery or any other commercial crop. Insecticide efficacy studies showed that some of the most commonly used insecticides are ineffective against A. helianthi. Resistance or tolerance to insecticides may explain its new status as a pest

    Active experiments using rocket-borne shaped charge barium releases

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    A reliable payload system and scaled down shaped charges were developed for carrying out experiments in solar-terrestrial magnetospheric physics. Four Nike-Tomahawk flights with apogees near 450 km were conducted to investigate magnetospheric electric fields, and two Taurus-Tomahawk rockets were flown in experiments on the auroral acceleration process in discrete auroras. In addition, a radial shaped charge was designed for plasma perturbation experiments

    Evaluation of a segment-based LANDSAT full-frame approach to corp area estimation

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    As the registration of LANDSAT full frames enters the realm of current technology, sampling methods should be examined which utilize other than the segment data used for LACIE. The effect of separating the functions of sampling for training and sampling for area estimation. The frame selected for analysis was acquired over north central Iowa on August 9, 1978. A stratification of he full-frame was defined. Training data came from segments within the frame. Two classification and estimation procedures were compared: statistics developed on one segment were used to classify that segment, and pooled statistics from the segments were used to classify a systematic sample of pixels. Comparisons to USDA/ESCS estimates illustrate that the full-frame sampling approach can provide accurate and precise area estimates

    Energy-constrained two-way assisted private and quantum capacities of quantum channels

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    With the rapid growth of quantum technologies, knowing the fundamental characteristics of quantum systems and protocols is essential for their effective implementation. A particular communication setting that has received increased focus is related to quantum key distribution and distributed quantum computation. In this setting, a quantum channel connects a sender to a receiver, and their goal is to distill either a secret key or entanglement, along with the help of arbitrary local operations and classical communication (LOCC). In this work, we establish a general theory of energy-constrained, LOCC-assisted private and quantum capacities of quantum channels, which are the maximum rates at which an LOCC-assisted quantum channel can reliably establish secret key or entanglement, respectively, subject to an energy constraint on the channel input states. We prove that the energy-constrained squashed entanglement of a channel is an upper bound on these capacities. We also explicitly prove that a thermal state maximizes a relaxation of the squashed entanglement of all phase-insensitive, single-mode input bosonic Gaussian channels, generalizing results from prior work. After doing so, we prove that a variation of the method introduced in [Goodenough et al., New J. Phys. 18, 063005 (2016)] leads to improved upper bounds on the energy-constrained secret-key-agreement capacity of a bosonic thermal channel. We then consider a multipartite setting and prove that two known multipartite generalizations of the squashed entanglement are in fact equal. We finally show that the energy-constrained, multipartite squashed entanglement plays a role in bounding the energy-constrained LOCC-assisted private and quantum capacity regions of quantum broadcast channels.Comment: 31 pages, 6 figure

    Predicting Cost/Reliability/Maintainability of Advanced General Aviation Avionics Equipment

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    A methodology is provided for assisting NASA in estimating the cost, reliability, and maintenance (CRM) requirements for general avionics equipment operating in the 1980's. Practical problems of predicting these factors are examined. The usefulness and short comings of different approaches for modeling coast and reliability estimates are discussed together with special problems caused by the lack of historical data on the cost of maintaining general aviation avionics. Suggestions are offered on how NASA might proceed in assessing cost reliability CRM implications in the absence of reliable generalized predictive models

    Sampling for area estimation: A comparison of full-frame sampling with the sample segment approach

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    The effect of sampling on the accuracy (precision and bias) of crop area estimates made from classifications of LANDSAT MSS data was investigated. Full-frame classifications of wheat and non-wheat for eighty counties in Kansas were repetitively sampled to simulate alternative sampling plants. Four sampling schemes involving different numbers of samples and different size sampling units were evaluated. The precision of the wheat area estimates increased as the segment size decreased and the number of segments was increased. Although the average bias associated with the various sampling schemes was not significantly different, the maximum absolute bias was directly related to sampling unit size

    Timber Cruising a la Francais

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    Private Edward M. Davis, 17th Co., 20th Engineers, will proceed from Castets, Landes, to La Chaise Dieu, Haute Loire, reporting upon arrival to District Commander of 20th Engineers for duty under Captain John D. Guthrie

    Effect of chloroacetic acids on the kidneys.

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    The effects of dichloroacetate (DCA) and trichloroacetate (TCA) administered in drinking water were studied. At high concentrations of either compound, weight loss, or failure to gain weight, was observed. Food consumption was also decreased; both effects were attributed to decreased water consumption. Renal phosphate-dependent glutaminase activity was increased at the highest concentration, and urinary ammonia was also increased. These changes indicated renal adaptation to an acid load. DCA, in pharmacological doses, impairs glucoenogenesis from lactate in part by decreasing lactate availability. Similar tendencies were observed in the present studies; however, female rats showed a biphasic response. At lower DCA concentrations, tissue lactate and plasma glucose concentrations were increased, whereas at higher concentrations of DCA, the expected decreases were observed
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