623 research outputs found
Quiet Clean Short-haul Experimental Engine (QCSEE). Aerodynamic and aeromechanical performance of a 50.8 cm (20 inch) diameter 1.34 PR variable pitch fan with core flow
The fan aerodynamic and aeromechanical performance tests of the quiet clean short haul experimental engine under the wing fan and inlet with a simulated core flow are described. Overall forward mode fan performance is presented at each rotor pitch angle setting with conventional flow pressure ratio efficiency fan maps, distinguishing the performance characteristics of the fan bypass and fan core regions. Effects of off design bypass ratio, hybrid inlet geometry, and tip radial inlet distortion on fan performance are determined. The nonaxisymmetric bypass OGV and pylon configuration is assessed relative to both total pressure loss and induced circumferential flow distortion. Reverse mode performance, obtained by resetting the rotor blades through both the stall pitch and flat pitch directions, is discussed in terms of the conventional flow pressure ratio relationship and its implications upon achievable reverse thrust. Core performance in reverse mode operation is presented in terms of overall recovery levels and radial profiles existing at the simulated core inlet plane. Observations of the starting phenomena associated with the initiation of stable rotor flow during acceleration in the reverse mode are briefly discussed. Aeromechanical response characteristics of the fan blades are presented as a separate appendix, along with a description of the vehicle instrumentation and method of data reduction
Effects of a Conducting Sphere Moving Through a Gradient Magnetic Field
We examine several conducting spheres moving through a magnetic field
gradient. An analytical approximation is derived and an experiment is conducted
to verify the analytical solution. The experiment is simulated as well to
produce a numerical result. Both the low and high magnetic Reynolds number
regimes are studied. Deformation of the sphere is noted in the high Reynolds
number case. It is suggested that this deformation effect could be useful for
designing or enhancing present protection systems against space debris.Comment: Presented at the AIAA Aerospace Sciences Meeting, Orlando, Florida,
Jan 4-7, 201
Devonian vertebrates from Australia
A vertebrate microfauna from the Lower Devonian (Emsian) of Australia is described. It is a taxonomically diverse assemblage, including disarticulated dermal skeletal fragments and/or teeth of Thelodonti, Placodermi, Cladodontida, Acanthodii, Onychodontidae, Rhipidistia, and Paleoniscida. Elements of this fauna have been described previously from geographically diverse localities of approximately equivalent age, but this Australian fauna is unique in possessing all of the above taxonomic groups in a single assemblage. This occurrence reinforces previous suggestions that the Lower Devonian fish fauna was widespread and uniform
West Virginia\u27s Seemingly Eternal Struggle for Fiscally and Environmentally Adequate Coal Mining Reclamation Bonding Program
Cryptographically Secure Information Flow Control on Key-Value Stores
We present Clio, an information flow control (IFC) system that transparently
incorporates cryptography to enforce confidentiality and integrity policies on
untrusted storage. Clio insulates developers from explicitly manipulating keys
and cryptographic primitives by leveraging the policy language of the IFC
system to automatically use the appropriate keys and correct cryptographic
operations. We prove that Clio is secure with a novel proof technique that is
based on a proof style from cryptography together with standard programming
languages results. We present a prototype Clio implementation and a case study
that demonstrates Clio's practicality.Comment: Full version of conference paper appearing in CCS 201
Measurements of neutrino oscillation in appearance and disappearance channels by the T2K experiment with 6.6 x 10(20) protons on target
111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee commentsWe thank the J-PARC staff for superb accelerator performance and the CERN NA61/SHINE Collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC, and CFI, Canada; CEA and CNRS/IN2P3, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; RSF, RFBR and MES, Russia; MINECO and ERDF funds, Spain; SNSF and SER, Switzerland; STFC, UK; and the U. S. Deparment of Energy, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK, and the Emerald High Performance Computing facility in the Centre for Innovation, UK. In addition, participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; and DOE Early Career program, USA
Search for short baseline nu(e) disappearance with the T2K near detector
8 pages, 6 figures, submitted to PRD rapid communication8 pages, 6 figures, submitted to PRD rapid communicationWe thank the J-PARC staff for superb accelerator performance and the CERN NA61 collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC and CFI, Canada; Commissariat `a l’Energie Atomique and Centre National de la Recherche Scientifique–Institut National de Physique Nucle´aire et de Physique des Particules, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; Russian Science Foundation, RFBR and Ministry of Education and Science, Russia; MINECO and European Regional Development Fund, Spain; Swiss National Science Foundation and State Secretariat for Education, Research and Innovation, Switzerland; STFC, UK; and DOE, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK. In addition participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; DOE Early Career program, USA
Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 pi(0) detector
10 pages, 6 figures, Submitted to PRDhttp://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.112010© 2015 American Physical Society11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PR
The migraine postdrome:An electronic diary study
OBJECTIVE: To report migraine postdrome symptoms in patients who report nonheadache symptoms as part of their attacks. METHODS: A prospective daily electronic diary study was conducted over 3 months in 120 patients with migraine. Nonheadache symptoms before, during, and after headache were collected on a daily basis. Visual analogue scales were used to capture the overall level of functioning and the severity of the headache. The postdrome was defined as the time from resolution of troublesome headache to return to normal. RESULTS: Of 120 evaluable patients, 97 (81%) reported at least one nonheadache symptom in the postdrome. Postdrome symptoms, in order of frequency, included feeling tired/weary and having difficulty concentrating and stiff neck. Many patients also reported a mild residual head discomfort. In most attacks (93%), there was return to normal within 24 hours after spontaneous pain resolved. There was no relationship between medication taken for the headache and the duration of the postdrome. The severity of the migraine was not associated with the duration of the postdrome. Overall state of health scores remained low during the postdrome. CONCLUSION: Nonheadache symptoms in the postdrome were common and may contribute to the distress and disability in the patients studied. Postdrome symptoms merit larger observational studies and careful recording in clinical trials of acute and preventive migraine treatments
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