48,104 research outputs found
Definition of technology development missions for early space stations: Large space structures
The objectives studied are the definition of the tested role of an early Space Station for the construction of large space structures. This is accomplished by defining the LSS technology development missions (TDMs) identified in phase 1. Design and operations trade studies are used to identify the best structural concepts and procedures for each TDMs. Details of the TDM designs are then developed along with their operational requirements. Space Station resources required for each mission, both human and physical, are identified. The costs and development schedules for the TDMs provide an indication of the programs needed to develop these missions
Efficient Computation of Power, Force, and Torque in BEM Scattering Calculations
We present concise, computationally efficient formulas for several quantities
of interest -- including absorbed and scattered power, optical force (radiation
pressure), and torque -- in scattering calculations performed using the
boundary-element method (BEM) [also known as the method of moments (MOM)]. Our
formulas compute the quantities of interest \textit{directly} from the BEM
surface currents with no need ever to compute the scattered electromagnetic
fields. We derive our new formulas and demonstrate their effectiveness by
computing power, force, and torque in a number of example geometries. Free,
open-source software implementations of our formulas are available for download
online
Radio Properties of the Auroral Ionosphere, Final Report (Phase I)
It has been found in recent years that a study of the fluctuations
in the signals received from radio stars affords a powerful means of
investigating the irregular structure of the ionosphere. In 1955 studies
of this type, using frequencies of 223 Me and 456 Me, were initiated
at the Geophysical Institute, with a view to investigating the smallscale
structure of the highly disturbed auroral ionosphere. The purpose
of this report is to present a complete description of the initial experimental
arrangement. Further developments of the equipment and some
results of analysis of the data have been presented in Quarterly Progress
Reports covering the period since 1 June 1956,
The report is divided into three sections. Section I contains a
description of the basic philosophy of the experiment with an elementary
discussion of the various parameters involved. Section II contains a
brief description of the actual field installation, and Section III is
devoted to the electronic design features.
The diagrams pertaining to each section are located at the end of
the section.Air Force Contract No. AF 30(635)-2887
Project No. 5535 - Task 45774
Rome Air Development Center, Griffiss Air Force Base
Rome, New YorkABSTRACT AND GENERAL INTRODUCTION -- [SECTION I] Investigation of the Ionosphere Using Extra- Terrestrial Radio Sources : 1.1 Introduction ; 1.2 Extra-Terrestrial Sources ; Apparent Positions ; 1.3 Instrumental Techniques for the Study of Radiation from Radio Stars ; Interferometer Methods ; Advantages of the Phase-Switch Interferometer ; Interferometer Parameters ; 1.5 Limitations on Accuracy -- References -- [SECTION II] The Field Installation : 2.1 Introduction ; 2.2 The Radio Telescope Towers ; 2.3 The Antennas ; 2.4 Acknowledgements -- [SECTION III] Electronic Design of Phase-Switch Interferometers : 3.1 Introduction ; 3.2 223 Mc Phase-Switch Equipment ; 3.3 456 Mc Phase-Switch Equipment ; 3.4 Auxiliary EquipmentYe
Shaping the future for primary care education and training project. Integrated health and social care: the perspectives of people using services: a mixed methods analysis
The aim of this study was to explore service users' perspectives concerning integrated health & social care, and
to identify the perceived strengths and weaknesses associated with the current workforce and services provided. The findings will be used to inform the education and training of
the health and social care workforce in the North West of Englan
The ASEAN Economic Community and the European experience
In November 2002, it was proposed at the Association of Southeast Asian Nations (ASEAN) Heads of Government meeting in Phnom Penh that the region should consider the possibility of creating an ASEAN Economic Community (AEC) by 2020. The name is evocative, for an Economic Community immediately brings to mind the European experience. In fact, when the Asian Pacific Economic Cooperation (APEC) was re-inventing itself, it was proposed that the words behind the organization's acronym be replaced with Asia-Pacific Economic Community. This idea was rejected explicitly for fear that it would give the impression that APEC was intending to move in the direction of the EC model, which was thought to be too controversial. --
A Parametric Study of Tillage Effects on Radar Backscatter
Radar backscatter data for different field configurations and modulation function curves for angular and frequency variations are presented. A simplistic approach to modeling this effect is presented. It is concluded that: (1) row direction is a significant contributor to radar backscatter from cropland and must be considered when making radar measurements over bare or sparsely vegetated fields; (2) while the effect decrease with increasing frequency, it is still large (5 dB) at 13.3 GHz; (3) row effects are independent of linear polarization; (4) there is a strong aspect angle sensitivity which is a function of the scene and radar system parameters
Computation of Casimir Interactions between Arbitrary 3D Objects with Arbitrary Material Properties
We extend a recently introduced method for computing Casimir forces between
arbitrarily--shaped metallic objects [M. T. H. Reid et al., Phys. Rev.
Lett._103_ 040401 (2009)] to allow treatment of objects with arbitrary material
properties, including imperfect conductors, dielectrics, and magnetic
materials. Our original method considered electric currents on the surfaces of
the interacting objects; the extended method considers both electric and
magnetic surface current distributions, and obtains the Casimir energy of a
configuration of objects in terms of the interactions of these effective
surface currents. Using this new technique, we present the first predictions of
Casimir interactions in several experimentally relevant geometries that would
be difficult to treat with any existing method. In particular, we investigate
Casimir interactions between dielectric nanodisks embedded in a dielectric
fluid; we identify the threshold surface--surface separation at which
finite--size effects become relevant, and we map the rotational energy
landscape of bound nanoparticle diclusters
Tests of Rotating Cylinders
Tests were made in the no. 1 wind tunnel at Langley Memorial Aeronautical Laboratory to determine the air forces acting on rotating cylinders with axes perpendicular to the direction of motion. One cylinder had a circular cross-section, the other that of a greek cross
The Multiple Deindustrializations of Canada’s Maritime Provinces and the Evaluation of Heritage-Related Urban Regeneration
The Maritime provinces of Canada share with many other nations the experience of nineteenth-century industrialization and twentieth-century deindustrialization. For deindustrialized areas, the social and environmental pressures imposed by deindustrialization are frequently held to be open to mitigation through urban regeneration projects
that seek to build on existing cultural heritage and ultimately enable communities to thrive in both cultural and economic terms. In the Maritime provinces, however, two factors have greatly complicated
the emergence of effective urban regeneration. One is the historical complexity of both industrialization and deindustrialization in the region, while the other is the critical weakness of evaluation criteria for
defining success in urban regeneration and thus assessing the effectiveness of regeneration projects. Without advocating the adoption of a ‘one-size-fits-all’ model, and recognizing the complexity – even intractability
– of the ‘wicked problems’ that attend any regeneration project, this essay will argue that historical and policy-related analysis can be combined to generate a regional approach to urban regeneration and its evaluation, which will take account of the need to maintain existing cultural integrity and to support processes of policy learning and social learning
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