9,166 research outputs found

    RSRM-11 (36OW011) ballistics mass properties (STS-35)

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    The propulsion performance and reconstructed mass properties data from Thiolol's RSRM-11 motors which were assigned to the STS-35 launch are contained. The Thiokol manufacturing designations for the motors were 360W011A/360W011B, which are referred to as RSRM-11A and RSRM-B, respectively. The launch of STS-35 occurred on 2 December 1990 at the Eastern Test Range (ETR). The data contained herein was input to the STS-35 Flight Evaluation Report. The SRM propellant, TP-H1148, is a composite type solid propellants, formulated of polybutediene acrylic acid, acryonitrile terpolymer binder, epoxy curing agent, ammonium perchlorate oxidizer, and aluminum powder fuel. A small amount of burning rate catalyst (iron oxide) was added to achieve the desired propellant burn rate. The propellant evaluation and raw material information for the RSRM-11 are included. The ballistic performance presented was based on the Operational Flight Instrumentation (OFI) 12.5 sample per second pressure data for the steady state and tail off portion of the pressure trace. Recent studies have shown that the transducers are affected by the measuring system at KSC and temperature gradients created by the igniter heaters. Therefore, an adjustment to the data from each transducer is made to make the initial reading match the atmospheric pressure at the time of launch

    The enviornmental assessment of a contemporary coal mining system

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    A contemporary underground coal mine in eastern Kentucky was assessed in order to determine potential off-site and on-site environmental impacts associated with the mining system in the given environmental setting. A 4 section, continuous room and pillor mine plan was developed for an appropriate site in eastern Kentucky. Potential environmental impacts were identified, and mitigation costs determined. The major potential environmental impacts were determined to be: acid water drainage from the mine and refuse site, uneven subsidence of the surface as a result of mining activity, and alteration of ground water aquifers in the subsidence zone. In the specific case examined, the costs of environmental impact mitigation to levels prescribed by regulations would not exceed $1/ton of coal mined, and post mining land values would not be affected

    A methodology for the environmental assessment of advanced coal extraction systems

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    Procedures developed to identify and assess potential environment impacts of advanced mining technology as it moves from a generic concept to a more systems definition are described. Two levels of assessment are defined in terms of the design stage of the technology being evaluated. The first level of analysis is appropriate to a conceptual design. At this level it is assumed that each mining process has known and potential environmental impacts that are generic to each mining activity. By using this assumption, potential environmental impacts can be identified for new mining systems. When two or more systems have been assessed, they can be evaluated comparing potential environmental impacts. At the preliminary stage of design, a systems performance can be assessed again with more precision. At this level of systems definition, potential environmental impacts can be analyzed and their significane determined in a manner to facilitate comparisons between systems. At each level of analysis, suggestions calculated to help the designer mitigate potentially harmful impacts are provided

    Disruption of reflecting Bose-Einstein condensates due to inter-atomic interactions and quantum noise

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    We perform fully three-dimensional simulations, using the truncated Wigner method, to investigate the reflection of Bose-Einstein condensates from abrupt potential barriers. We show that the inter-atomic interactions can disrupt the internal structure of a cigar-shaped cloud with a high atom density at low approach velocities, damping the center-of-mass motion and generating vortices. Furthermore, by incorporating quantum noise we show that scattering halos form at high approach velocities, causing an associated condensate depletion. We compare our results to recent experimental observations.Comment: 5 figure

    MOS CCDs for the wide field imager on the XEUS spacecraft

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    In recent years the XEUS mission concept has evolved and has been the subject of several industrial studies. The mission concept has now matured to the point that it could be proposed for a Phase A study and subsequent flight programme. The key feature of XEUS will be its X-ray optic with collecting area ~30-100x that of XMM. The mission is envisaged at an orbit around the L2 point in space, and is formed from two spacecraft; one for the mirrors, and the other for the focal plane detectors. With a focal length of 50m, the plate scale of the optic is 6.5x that of XMM, which using existing focal plane technology will reduce the effective field of view to a few arc minutes. Cryogenic instrumentation, with detector sizes of a few mm can only be used for narrow field studies of target objects, and a wide field instrument is under consideration using a DEPFET pixel array to image out to a diameter of 5 arcminutes, requiring an array of dimension 70mm. It is envisaged to extend this field of view possibly out to 15 arcminutes through the use of an outer detection ring comprised of MOS CCD

    Dissipation in nanocrystalline-diamond nanomechanical resonators

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    We have measured the dissipation and frequency of nanocrystalline-diamond nanomechanical resonators with resonant frequencies between 13.7 MHz and 157.3 MHz, over a temperature range of 1.4–274 K. Using both magnetomotive network analysis and a time-domain ring-down technique, we have found the dissipation in this material to have a temperature dependence roughly following T^(0.2), with Q^(–1) ≈ 10^(–4) at low temperatures. The frequency dependence of a large dissipation feature at ~35–55 K is consistent with thermal activation over a 0.02 eV barrier with an attempt frequency of 10 GHz

    Increased disease activity, severity and autoantibody positivity in rheumatoid arthritis patients with co-existent bronchiectasis.

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    PublishedArticleCopyright © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty LtdAim: Patients with rheumatoid arthritis (RA) and co-existent Bronchiectasis (BRRA) have a 5-fold increased mortality compared to rheumatoid arthritis alone. Yet previous studies have found no difference in clinical and serological markers of RA disease severity between BRRA patients and RA alone. RA disease activity measures such as DAS28-CRP and anti-cyclic citrullinated peptide antibodies (anti-CCP) however have not been studied, so we assessed these parameters in patients with BRRA and RA alone. Methods: BRRA patients (n = 53) had HRCT proven bronchiectasis without any interstitial lung disease and ≄2 respiratory infections/year. RA alone patients (n = 50) had no clinical or radiological evidence of lung disease. DAS28-CRP, rheumatoid factor (IgM) and anti-CCP were measured in all patients, together with detailed clinical and radiology records. Results: In BRRA, BR predated RA in 58% of patients. BRRA patients had higher DAS28 scores (3.51 vs. 2.59), higher levels of anti-CCP (89 vs. 46%) and RF (79 vs. 52%) (p = 0.003) compared to RA alone. Where hand and foot radiology findings were recorded, 29/37 BRRA (78%) and 13/30 (43%) RA alone had evidence of erosive change (p = 0.003). There were no significant differences between groups in smoking history or DMARD/biologic therapy. Conclusions: Increased levels of RA disease activity, severity and RA autoantibodies are demonstrated in patients with RA and co-existent bronchiectasis compared to patients with RA alone, despite lower tobacco exposure. This study demonstrates that BRRA is a more severe systemic disease than RA alone.Arthritis Research UKHEFCECornwall Arthritis TrustNorthcott Devon Medical FoundationDutchy Health CharityNIHR CLR

    Bivariate tt-distribution for transition matrix elements in Breit-Wigner to Gaussian domains of interacting particle systems

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    Interacting many-particle systems with a mean-field one body part plus a chaos generating random two-body interaction having strength λ\lambda, exhibit Poisson to GOE and Breit-Wigner (BW) to Gaussian transitions in level fluctuations and strength functions with transition points marked by λ=λc\lambda=\lambda_c and λ=λF\lambda=\lambda_F, respectively; λF>>λc\lambda_F >> \lambda_c. For these systems theory for matrix elements of one-body transition operators is available, as valid in the Gaussian domain, with λ>λF\lambda > \lambda_F, in terms of orbitals occupation numbers, level densities and an integral involving a bivariate Gaussian in the initial and final energies. Here we show that, using bivariate tt-distribution, the theory extends below from the Gaussian regime to the BW regime up to λ=λc\lambda=\lambda_c. This is well tested in numerical calculations for six spinless fermions in twelve single particle states.Comment: 7 pages, 2 figure
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