7,744 research outputs found
Investigation of a geodesy coexperiment to the Gravity Probe B relativity gyroscope program
Geodesy is the science of measuring the gravitational field of and positions on the Earth. Estimation of the gravitational field via gravitation gradiometry, the measurement of variations in the direction and magnitude of gravitation with respect to position, is this dissertation's focus. Gravity Probe B (GP-B) is a Stanford satellite experiment in gravitational physics. GP-B will measure the precession the rotating Earth causes on the space time around it by observing the precessions of four gyroscopes in a circular, polar, drag-free orbit at 650 km altitude. The gyroscopes are nearly perfect niobium-coated spheres of quartz, operating at 1.8 K to permit observations with extremely low thermal noise. The permissible gyroscope drift rate is miniscule, so the torques on the gyros must be tiny. A drag-free control system, by canceling accelerations caused by nongravitational forces, minimizes the support forces and hence torques. The GP-B system offers two main possibilities for geodesy. One is as a drag-free satellite to be used in trajectory-based estimates of the Earth's gravity field. We described calculations involving that approach in our previous reports, including comparison of laser only, GPS only, and combined tracking and a preliminary estimate of the possibility of estimating relativistic effects on the orbit. The second possibility is gradiometry. This technique has received a more cursory examination in previous reports, so we concentrate on it here. We explore the feasibility of using the residual suspension forces centering the GP-B gyros as gradiometer signals for geodesy. The objective of this work is a statistical prediction of the formal uncertainty in an estimate of the Earth's gravitation field using data from GP-B. We perform an instrument analysis and apply two mathematical techniques to predict uncertainty. One is an analytical approach using a flat-Earth approximation to predict geopotential information quality as a function of spatial wavelength. The second estimates the covariance matrix arising in a least-squares estimate of a spherical harmonic representation of the geopotential using GP-B gradiometer data. The results show that the GP-B data set can be used to create a consistent estimate of the geopotential up to spherical harmonic degree and order 60. The formal uncertainty of all coefficients between degrees 5 and 50 is reduced by factors of up to 30 over current satellite-only estimates and up to 7 over estimates which include surface data. The primary conclusion resulting from this study is that the gravitation gradiometer geodesy coexperiment to GP-B is both feasible and attractive
POTENTIAL IMPACTS OF PHARMACEUTICAL USES OF TRANSGENIC TOBACCO: THE CASE OF HUMAN SERUM ALBUMIN (HSA)
The potential size and distribution of benefits from transgenic tobacco as a source of human serum albumin are estimated using an economic surplus model with imperfect competition. The results demonstrate that new products from bio-pharming applications stand to generate significant social benefits.Research and Development/Tech Change/Emerging Technologies,
Complexity, Collective Effects and Modelling of Ecosystems: formation, function and stability
We discuss the relevance of studying ecology within the framework of
Complexity Science from a statistical mechanics approach. Ecology is concerned
with understanding how systems level properties emerge out of the multitude of
interactions amongst large numbers of components, leading to ecosystems that
possess the prototypical characteristics of complex systems. We argue that
statistical mechanics is at present the best methodology available to obtain a
quantitative description of complex systems, and that ecology is in urgent need
of ``integrative'' approaches that are quantitative and non-stationary. We
describe examples where combining statistical mechanics and ecology has led to
improved ecological modelling and, at the same time, broadened the scope of
statistical mechanics.Comment: 11 pages and 1 figur
Medico-Legal Aspects of the Nervous System as a Functioning Unit of the Body
We have had the pleasure of working together in recent years on Law-Science problems. During that time we have become increasingly convinced that it is necessary for trial lawyer and scientist alike to think of the human being in terms of the nine main organ systems,\u27reserving a tenth category for the field of personality as the latter represents a synthesis of component structures and functions into variable reaction and behavior patterns. An injury or disability may involve impairment or destruction of an an atomic member or of physiological function; it may involve effects on personality, or psychic values, alone, without discoverable organic lesion, or it may cause disocations both in organ systems and in over-all personality. To achieve a scientific approach to medico-legal problems one must undertake focal analysis in the discovery, or exploratory phases, and synthesis in the phases of evaluation and prognosis
THE ECONOMIC IMPACT OF GENETICALLY MODIFIED ORGANISMS IN SMALL DEVELOPING COUNTRIES
The expected benefits from herbicide resistant transgenic rice in Uruguay are estimated with stochastic simulation techniques. Economic surplus methods that account for private profits are used to measure the magnitude and distribution of the benefits between producers and a multinational firm. Further, the adoption rate of transgenic rice is endogenous in the model and depends on the expected profitability of the technology. The results show that the potential benefits from the technology are relatively small because of the small production base. Multinational firms are, therefore, unlikely to develop locally adapted transgenic rice varieties without strategic partnerships with local institutions.Research and Development/Tech Change/Emerging Technologies,
Tom Boy (Rag Two Step)
Illustration of black cat in front of a full moonhttps://scholarsjunction.msstate.edu/cht-sheet-music/3980/thumbnail.jp
(2R,4R)-4-(2-Ethoxy-2-oxoethyl)-2,6,6-trimethyl–2-oxo-1,3,6,2λ5-dioxazaphosphocan-6-ium iodide
The title compound, C11H23NO5P+·I−, consists of an eight-membered cationic heterocyclic ring in a boat–chair conformation. The ring features a tetraalkylammonium N and a methylphosphonate P atom. A –CH2(CO)OC2H5 ester side chain at the C adjacent to oxygen produces two chiral centers at that substituted C atom and the P atom, both of which were determined to have absolute R,R configurations. A previously determined racemic bromide analog has exactly the same ring but with a –C15H31 side chain. In that structure, both chiral centers show the same relative R/S,R/S configurations, but the ring in the bromide analog is in a boat conformation
Extraction of the Axial Nucleon Form Factor from Neutrino Experiments on Deuterium
We present new parameterizations of vector and axial nucleon form factors. We
maintain an excellent descriptions of the form factors at low momentum
transfers (), where the spatial structure of the nucleon is important, and
use the Nachtman scaling variable to relate elastic and inelastic form
factors and impose quark-hadron duality constraints at high where the
quark structure dominates. We use the new vector form factors to re-extract
updated values of the axial form factor from \numu experiments on deuterium.
We obtain an updated world average value from \numud, \numubarH and pion
electroproduction experiments of = . Our
parameterizations are useful in modeling interactions at low energies
(e.g. for \numu oscillations experiments). The predictions for high can
be tested in the next generation electron and \numu scattering experiments.Comment: Presented by A. Bodek at the European Physical Society Meeting,
EPS2007, Manchester, England, July 2007, 4 pages, 2 figure
New atlas of IR solar spectra
Over 4500 absorption lines have been marked on the spectra and the corresponding line positions tabulated. The associated absorbing telluric or solar species for more than 90% of these lines have been identified and only a fraction of the unidentified lines have peak absorptions greater than a few percent. The high resolution and the low Sun spectra greatly enhance the sensitivity limits for identification of trace constituents
Neurophysiology
Contains reports on three research projects.National Institutes of Health (Grant 5 RO1 NB-04985-03)Instrumentation Laboratory under the auspices of DSR Project 55-257Bioscience Division of National Aeronautics and Space Administration through Contract NSR 22-009-138Bell Telephone Laboratories, Inc. (Grant)The Teagle Foundation, Inc. (Grant)U. S. Air Force (Aerospace Medical Division) under Contract AF33(615)-388
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