3,470 research outputs found
Investigation of Hole Caving Due to Vibrations
Foundations for a power plant were constructed by drilling holes in cemented sand for 36 piers. The boreholes in the cemented sand did not cave. A major design change required the demolition of the original piers and pile caps with large hoe rams and the drilling of new 36 boreholes in the same location. The new drilling contractor experienced widespread caving, which he was unable to remedy. The authors first investigated the possibility that the second contractor used inferior equipment or techniques. Then the authors investigated the possibility that a loss in soil cohesion occurred due to the vibrations from pier/pile cap demolition and casing installation. Analyses performed included (1) peak particle velocity evaluation, (2) laterally loaded pile/fatigue analysis, and (3) finite element analysis. It was concluded that significant loss of cohesion due to these vibrations was plausible and that the loss of cohesion could account for the bole caving
Preparation of thin polymer films for infrared reaction rate studies
Procedure for preparing thin films for infrared spectrophotometric analysis involves pressing of a neat mixture of reactants between nonreactive thin polymer films with noninterfering absorption bands. Pressing is done under a pressure that gives desirable thickness. Following this process, the film sandwich is cut to accommodate the laboratory instrument
Application of the ERTS system to the study of Wyoming resources with emphasis on the use of basic data products
Many potential users of ERTS data products and other aircraft and satellite imagery are limited to visual methods of analyses of these products. Illustrations are presented from Wyoming studies that have employed these standard data products for a variety of geologic and related studies. Possible economic applications of these studies are summarized. Studies include regional geologic mapping for updating and correcting existing maps and to supplement incomplete regional mapping; illustrations of the value of seasonal images in geologic mapping; specialized mapping of such features as sand dunes, playa lakes, lineaments, glacial features, regional facies changes, and their possible economic value; and multilevel sensing as an aid in mineral exploration. Examples of cooperative studies involving botanists, plant scientists, and geologists for the preparation of maps of surface resources that can be used by planners and for environmental impact studies are given
Motion of magnetic flux through superconducting strips
Electric resistance of superconducting strips in magnetic fiel
Measuring atomic NOON-states and using them to make precision measurements
A scheme for creating NOON-states of the quasi-momentum of ultra-cold atoms
has recently been proposed [New J. Phys. 8, 180 (2006)]. This was achieved by
trapping the atoms in an optical lattice in a ring configuration and rotating
the potential at a rate equal to half a quantum of angular momentum . In this
paper we present a scheme for confirming that a NOON-state has indeed been
created. This is achieved by spectroscopically mapping out the anti-crossing
between the ground and first excited levels by modulating the rate at which the
potential is rotated. Finally we show how the NOON-state can be used to make
precision measurements of rotation.Comment: 14 preprint pages, 7 figure
Climate cosmopolitics and the possibilities for urban planning
Cosmopolitical action in a climate-changed city represents different knowledges and practices that may seem disconnected but constellate to frame stories and spaces of a climate-just city. The question this article asks is: how might we as planners identify and develop counter-hegemonic praxes that enable us to re-imagine our experience of, and responses to, climate change? To explore this question, we draw on Isabelle Stengers's (2010) idea of cosmopolitics-where diverse stories, perspectives, experiences, and practices can connect to create the foundation for new strategic possibilities. Our article is empirically informed by conversations with actors from three Australian cities (Sydney, Brisbane, and Perth) who are mobilizing different approaches to this ideal in various grassroots actions on climate change
Sliding Mode Implementation of an Attitude Command Flight Control System for a Helicopter in Hover
This paper presents an investigation into the design of a flight control system, using a decoupled non-linear sliding mode control structure, designed using a linearised, 9th order representation of the dynamics of a PUMA helicopter in hover. The controllers are then tested upon a higher order, non-linear helicopter model, called RASCAL. This design approach is used for attitude command flight control implementation and the control performance is assessed in the terms of handling qualities through the Aeronautical Design Standards for Rotorcraft (ADS-33). In this context a linearised approximation of the helicopter system is used to design an SMC control scheme. These controllers have been found to yield a system that satisfies the Level 1 handling qualities set out by ADS-33.
Fit for work? Health, employability and challenges for the UK welfare reform agenda
This article introduces a special issue of Policy Studies entitled āFit for work? Health, employability and challenges for the UK welfare reform agendaā. Growing from a shared concern over the need to expand the evidence base around the processes that led to large numbers of people claiming disability benefits in the UK, it brings together contributions from leading labour market and social policy researchers providing evidence and commentary on major reforms to Incapacity Benefit (IB) in the UK. This special issue address three key questions: what are the main causes of the long-term rise in the number of people claiming IBs; what will reduce the number of claimants; and what is likely to deliver policy effectively and efficiently? This introduction first explains and examines the challenges to reforms to IB in the UK, and then, in conclusion, highlights the answers to the previous three questions ā first, labour market restructuring and marginalisation have driven the rise in numbers claiming IBs. Second, economic regeneration in the Britainās less prosperous areas coupled with intensive and sustained supply-side support measures will bring numbers down. Third, delivery need to be flexible and tailored to individual needs and needs to be able to access local and expert knowledge in a range of organisations, including Job Centre Plus, the NHS as well as the private and voluntary sectors
Ferromagnetic resonance force microscopy on a thin permalloy film
Ferromagnetic Resonance Force Microscopy (FMRFM) offers a means of performing
local ferromagnetic resonance. We have studied the evolution of the FMRFM force
spectra in a continuous 50 nm thick permalloy film as a function of probe-film
distance and performed numerical simulations of the intensity of the FMRFM
probe-film interaction force, accounting for the presence of the localized
strongly nonuniform magnetic field of the FMRFM probe magnet. Excellent
agreement between the experimental data and the simulation results provides
insight into the mechanism of FMR mode excitation in an FMRFM experiment.Comment: 9 pages, 2 figure
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