12,391 research outputs found

    Flammability study of materials in oxygen environments

    Get PDF
    Report presents flame-propagation rates and flammability ratings of 780 specimens of commercially available plastics, elastomers, coatings, fabrics, and other sheet materials. Test results are also given for over 1970 samples of most commonly used electrical harnesses, connectors, and potting compounds

    Tri-county pilot study

    Get PDF
    The author has identified the following significant results. An area inventory was performed for three southeast Texas counties (Montgomery, Walker, and San Jacinto) totaling 0.65 million hectares. The inventory was performed using a two level hierarchy. Level 1 was divided into forestland, rangeland, and other land. Forestland was separated into Level 2 categories: pine, hardwood, and mixed; rangeland was not separated further. Results consisted of area statistics for each county and for the entire study site for pine, hardwood, mixed, rangeland, and other land. Color coded county classification maps were produced for the May data set, and procedures were developed and tested

    Towards practical classical processing for the surface code: timing analysis

    Full text link
    Topological quantum error correction codes have high thresholds and are well suited to physical implementation. The minimum weight perfect matching algorithm can be used to efficiently handle errors in such codes. We perform a timing analysis of our current implementation of the minimum weight perfect matching algorithm. Our implementation performs the classical processing associated with an nxn lattice of qubits realizing a square surface code storing a single logical qubit of information in a fault-tolerant manner. We empirically demonstrate that our implementation requires only O(n^2) average time per round of error correction for code distances ranging from 4 to 512 and a range of depolarizing error rates. We also describe tests we have performed to verify that it always obtains a true minimum weight perfect matching.Comment: 13 pages, 13 figures, version accepted for publicatio

    Seasonal Use of Bridges by Rafinesque\u27s Big-Eared Bat, \u3ci\u3eCorynorhinus rafinesquii\u3c/i\u3e, in Southern Mississippi

    Get PDF
    We conducted surveys of concrete bridges in southern Mississippi from 2000–2002 to determine the phenological pattern of use by Rafinesque\u27s big-eared bat, Corynorhinus rafinesquii. The earliest dates on which we located maternity colonies were 9 March 2000, 20 April 2001, and 15 May 2002. Maternity colonies increased in size and abundance as spring progressed. Pups were born in mid- to late May (first observed 12 May 2000, 15 May 2001, 27 May 2002) and nursed through midsummer (lactating females last captured 14 July 2000, 25 July 2001, 16 July 2002). Colony size and percentage of bridges occupied by bats declined in late summer. Colonies were absent during fall and winter, although we occasionally found solitary individuals during these seasons. Number of bats present under an occupied bridge ranged from 1 to 25. The mean number of individuals per occupied bridge was 4.6 (SD = 5.8) in 2000, 3.9 (SD = 5.0) in 2001, and 3.0 (SD = 4.4) in 2002. The mean number of adult females per maternity colony was 5.6 (SD = 3.1). Although we found males throughout the study period, females were largely absent from bridges outside of the maternity season, suggesting that much of the population used alternate roosts during this time

    Enantioselective Organocatalytic Indole Alkylations. Design of a New and Highly Effective Chiral Amine for Iminium Catalysis

    Get PDF
    The indole framework has become widely identified as a “privileged” structure with representation in over 3000 natural isolates and 40 medicinal agents of diverse therapeutic action. A new strategy for asymmetric access to this important pharmacaphore has been accomplished that involves the amine catalyzed alkylation of indoles with α,β-unsaturated aldehydes. Central to these studies has been the design of a new chiral amine catalyst that exhibits improved reactivity and selectivity for iminium catalysis. This new (2S,5S)-5-benzyl-2-tert-butyl-imidazolidinone catalyst has enabled the conjugate addition of a variety of indole systems to a diverse range of α,β-unsaturated aldehydes in high yield and with excellent levels of enantiocontrol (70−97% yield, 84−97% ee). A demonstration of the utility of this new organocatalytic alkylation for the rapid construction of biomedically relevant molecules is presented in the enantioselective synthesis of an indolobutyric acid COX-2 inhibitor

    Recent Extreme Ultraviolet Solar Spectra and Spectroheliograms

    Get PDF
    Extreme ultraviolet solar spectra and spectroheliogram analyse

    Smart Weights

    Get PDF
    The goal of this project is to design and implement weights which can record and analyze work out patterns. Motivation for this project stems from the high cost of personal training. The hope is that this device will provide many of the benefits a user receives from personal training at only a fraction of the cost. The Smart Weight is designed with an on-board Inertial Measurement Unit providing acceleration, gyroscope, and magnetometer data. A microcontroller records and analyzes changes in motion, feeding this data into Multiplicative Recurrent Neural Network (MRNN) for exercise classification. A Raspberry Pi was chosen as the microcontroller, along with a Polulu Minimu-9 V2 for the IMU. These were attached to a five pound free-weight, where the motion of an exercise could be accurately recorded. The IMU communicates with the Raspberry Pi via the i2c protocol, and provides roughly 50 data points per second. Code was written to preprocess and feed data from the IMU into the MRNN, where the type of exercise can then be determined. The MRNN was trained on graphics processing units (GPUs) with the help of Ersatz Labs, a company that specializes in training Neural Networks. The prototype Smart Weight is able to classify one exercise (the bicep curl) with an accuracy of over 90%, but many more exercises will be added in the future

    Towards practical classical processing for the surface code

    Full text link
    The surface code is unarguably the leading quantum error correction code for 2-D nearest neighbor architectures, featuring a high threshold error rate of approximately 1%, low overhead implementations of the entire Clifford group, and flexible, arbitrarily long-range logical gates. These highly desirable features come at the cost of significant classical processing complexity. We show how to perform the processing associated with an nxn lattice of qubits, each being manipulated in a realistic, fault-tolerant manner, in O(n^2) average time per round of error correction. We also describe how to parallelize the algorithm to achieve O(1) average processing per round, using only constant computing resources per unit area and local communication. Both of these complexities are optimal.Comment: 5 pages, 6 figures, published version with some additional tex
    corecore