55,502 research outputs found
Contaminant ions and waves in the space station environment
The probable plasma (ions and electrons) and plasma wave environment that will exist in the vicinity of the Space Station and how this environment may affect the operation of proposed experiments are discussed. Differences between quiescent operational periods and non-operational periods are also addressed. Areas which need further work are identified and a course of action suggested
Pressure limiting propellant actuating system
A pressure limiting propellant activating system for simultaneously limiting the output force while maintaining a constant output pressure from the combustion chamber is described. The propellant actuated system includes an outer barrel, outer housing and a combustion chamber. A main piston is movable in the barrel housing when gas pressure is developed in the combustion chamber. A relief piston is concentrically mounted and fixedly movable with the main piston when gas pressure is exerted from the combustion. A relief piston has a force-activated separation mechanism for limiting the output force while simultaneously maintaining constant output pressure on the main piston from the combustion chamber
Polarized Scattering in the Vicinty of Galaxies
Some bright cD galaxies in cluster cooling flows have Thomson optical depths
exceeding 0.01. A few percent of their luminosity is scattered and appears as
diffuse polarized emission. We calculate the scattering process for different
geometric combinations of luminosity sources and scattering media. We apply our
results to galaxies, with and without active nuclei, immersed in cooling flows.
We model observations of NGC 1275 and M87 (without active nuclei) in the
presence of sky and galactic background fluxes which hinder the measurement of
the scattered light at optical wavelengths. Current instruments are unable to
detect the scattered light from such objects. However, when a galaxy has an
active nucleus of roughly the same luminosity as the remainder of the galaxy in
V, both the total and polarized scattered intensity should observable on large
scales (5--30kpc), meaning intensity levels greater than 1% of the background
level. For typical AGN and galaxy spectral distributions, the scattering is
most easily detected at short (U) wavelengths. We point out that a number of
such cases will occur. We show that the radiation pattern from the central
nuclear region can be mapped using the scattering. We also show that the
scattered light can be used to measure inhomogeneities in the cooling flow.Comment: 29 pages of TEX, 14 figs, CRSR-1046, in ApJ Nov 20, 199
The square root law and structure of finite rings
Let be a finite ring and define the hyperbola . Suppose that for a sequence of finite odd order rings of size tending
to infinity, the following "square root law" bound holds with a constant
for all non-trivial characters on : Then, with a finite number of
exceptions, those rings are fields.
For rings of even order we show that there are other infinite families given
by Boolean rings and Boolean twists which satisfy this square-root law
behavior. We classify the extremal rings, those for which the left hand side of
the expression above satisfies the worst possible estimate. We also describe
applications of our results to problems in graph theory and geometric
combinatorics.
These results provide a quantitative connection between the square root law
in number theory, Salem sets, Kloosterman sums, geometric combinatorics, and
the arithmetic structure of the underlying rings
Complex Personhood as the Context for Intimate Partner Victimization: One American Indian Woman\u27s Story
This qualitative case study explores one American Indian (AI) womanâs experience of intimate partner violence and the subsequent murder of her abusive partner. The lens of complex personhood (Gordon, 1997) has been applied as a method for understanding âAnnieâsâ multiple identities of AI woman, victim of intimate partner violence, mother, and convicted felon. The aim of the current case study was to uncover implicit and explicit meanings embedded in the experiences of moving from a victim of IPV to an off ender by applying a framework of hermeneutic phenomenology as the methodology. Three relational themes emerged from the interview data: âGetting out of Hand,â âTheyâre in my Footstep all the Way Now,â and âWhatâs a Miranda Rightâ? Lastly, this article begins an exploration into the complex link between victimization and off ending as it applies to one battered woma
Pilot workload and fatigue: A critical survey of concepts and assessment techniques
The principal unresolved issues in conceptualizing and measuring pilot workload and fatigue are discussed. These issues are seen as limiting the development of more useful working concepts and techniques and their application to systems engineering and management activities. A conceptual analysis of pilot workload and fatigue, an overview and critique of approaches to the assessment of these phenomena, and a discussion of current trends in the management of unwanted workload and fatigue effects are presented. Refinements and innovations in assessment methods are recommended for enhancing the practical significance of workload and fatigue studies
High-altitude plume computer code development
The flowfield codes that have been developed to predict rocket motor plumes at high altitude were used to predict plume properties for the RCS motor which show reasonable agreement with experimental data. A systematic technique was established for the calculation of high altitude plumes. The communication of data between the computer codes was standardized. It is recommended that these outlined procedures be more completed, documented and updated as the plume methodology is applied to the varied problems of plume flow and plume impingement encountered by space station design and operation
Is there a close association between "soils" and "vegetation"? : A case study from central western New South Wales
The assumption that âsoilsâ and âvegetationâ are closely associated was tested by describing soils and vegetation along a Travelling Stock Reserve west of Grenfell, New South Wales (lat 33° 55âS, long 147° 45âE). The transect was selected on the basis of (a) minimising the effects of non-soil factors (human interference, climate and relief) on vegetation and (b) the presence of various soil and vegetation types as indicated by previous mapping. âSoilsâ were considered at three levels: soil landscapes (a broad mapping unit widely used in central western NSW), soil types (according to a range of classifications) and soil properties (depth, pH, etc.). âVegetationâ was considered in three ways: vegetation type (in various classifications), density/floristic indices (density of woody species, abundance of native species, etc.) and presence/absence of individual species. Sites along the transect were grouped according to soil landscapes or soil types and compared to vegetation types or indices recorded at the sites. Various measures indicated low associations between vegetation types and soil landscapes or soil types. Except for infrequent occurrences of a soil type or landscape, any one soil type or landscape was commonly associated with a number of vegetation types and any one vegetation type was associated with a number of soil landscapes or soil types. However, significant associations between some vegetation indices, mainly density or numbers of woody species, and some soil landscapes and soil types were evident. Although many species were relatively ubiquitous, some groups of species that were restricted to one or two soil types were identified. Canonical Correspondence Analysis provided some suggestions as to which properties (e.g. texture) of these soils were associated with the presence of particular species
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