172,255 research outputs found
EKG isolator
Light beam transmits heartbeat signal from electrodes on patient to electrocardiograph without exposing patient to possible severe electrical shock. System provides complete isolation between patient and EKG instrumentation
Advanced General Aviation Turbine Engine (GATE) study
The small engine technology requirements suitable for general aviation service in the 1987 to 1988 time frame were defined. The market analysis showed potential United States engines sales of 31,500 per year providing that the turbine engine sales price approaches current reciprocating engine prices. An optimum engine design was prepared for four categories of fixed wing aircraft and for rotary wing applications. A common core approach was derived from the optimum engines that maximizes engine commonality over the power spectrum with a projected price competitive with reciprocating piston engines. The advanced technology features reduced engine cost, approximately 50 percent compared with current technology
Kondo insulators in the periodic Anderson model: a local moment approach
The symmetric periodic Anderson model is well known to capture the essential
physics of Kondo insulator materials. Within the framework of dynamical
mean-field theory, we develop a local moment approach to its single-particle
dynamics in the paramagnetic phase. The approach is intrinsically
non-perturbative, encompasses all energy scales and interaction strengths, and
satisfies the low-energy dictates of Fermi liquid theory. It captures in
particular the strong coupling behaviour and exponentially small quasiparticle
scales characteristic of the Kondo lattice regime, as well as simple
perturbative behaviour in weak coupling. Particular emphasis is naturally given
to strong coupling dynamics, where the resultant clean separation of energy
scales enables the scaling behaviour of single-particle spectra to be obtained.Comment: 15 pages, 10 postscript figures, accepted for publication in EPJ B;
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Digital computing cardiotachometer
A tachometer is described which instantaneously measures heart rate. During the two intervals between three succeeding heart beats, the electronic system: (1) measures the interval by counting cycles from a fixed frequency source occurring between the two beats; and (2) computes heat rate during the interval between the next two beats by counting the number of times that the interval count must be counted to zero in order to equal a total count of sixty times (to convert to beats per minute) the frequency of the fixed frequency source
Cardiotachometer displays heart rate on a beat-to-beat basis
Electronics for this system may be chosen so that complete calculation and display may be accomplished in a few milliseconds, far less than even the fastest heartbeat interval. Accuracy may be increased, if desired, by using higher-frequency timing oscillator, although this will require large capacity registers at increased cost
Computer mapping of turbidity and circulation patterns in Saginaw Bay, Michigan from LANDSAT data
The author has identified the following significant results. LANDSAT was used as a basis for producing geometrically-corrected, color-coded imagery of turbidity and circulation patterns in Saginaw Bay, Michigan (Lake Huron). This imagery shows nine discrete categories of turbidity, as indicated by nine Secchi depths between 0.3 and 3.3 meters. The categorized imagery provided an economical basis for extrapolating water quality parameters from point samples to unsample areas. LANDSAT furnished a synoptic view of water mass boundaries that no amount of ground sampling or monitoring could provide
Dynamics and transport properties of Kondo insulators
A many-body theory of paramagnetic Kondo insulators is described, focusing
specifically on single-particle dynamics, scattering rates, d.c. transport and
optical conductivities. This is achieved by development of a non-perturbative
local moment approach to the symmetric periodic Anderson model within the
framework of dynamical mean-field theory. Our natural focus is the strong
coupling, Kondo lattice regime; in particular the resultant `universal' scaling
behaviour in terms of the single, exponentially small low-energy scale
characteristic of the problem. Dynamics/transport on all relevant ()
scales are considered, from the gapped/activated behaviour characteristic of
the low-temperature insulator through to explicit connection to single-impurity
physics at high and/or ; and for optical conductivities emphasis is
given to the nature of the optical gap, the temperature scale responsible for
its destruction, and the consequent clear distinction between indirect and
direct gap scales. Using scaling, explicit comparison is also made to
experimental results for d.c. transport and optical conductivites of
Ce_3Bi_4Pt_3, SmB_6 and YbB_{12}. Good agreement is found, even quantitatively;
and a mutually consistent picture of transport and optics results.Comment: 49 pages, 23 figure
A simple ansatz to describe thermodynamic quantities of peptides and proteins at low temperatures
We describe a simple ansatz to approximate the low temperature behavior of
proteins and peptides by a mean-field-like model which is analytically
solvable. For a small peptide some thermodynamic quantities are calculated and
compared with numerical results of an all-atoms simulation. Our approach can be
used to determine the weights for a multicanonical simulation of the molecule
under consideration.Comment: 11 pages, Latex, 4 Postscript figures, to appear in Int. J. Mod.
Phys. C (1997
Automated weld torch guidance control system
A device for automatically controlling the movement of a welding torch while welding an elongated joint is described. A charge injection television camera is carried on a movable support. The camera includes a matrix of individual light sensing video elements which generate voltages responsive to light reflected off of the joint and surrounding areas of the work piece. The voltages produced by the pixels are converted to digital words which are fed to a microprocessor for generating an error signal. This error signal is fed to a digital motor which is used to drive a movable support upon which the television camera is carried
ERTS-1: Automated land-use mapping in lake watersheds
The author has identified the following significant results. ERTS-1 computer compatible tapes were used as a basis to generate land use maps in lake watersheds in southeastern Michigan. These maps, generated on a repetitive basis, provide information essential to governmental agencies concerned with planning and control of lake eutrophication. The ERTS mapping products included geometrically current land use map overlays at 1:250,000 and 1:48,000 scale and area measurement printouts. The printouts provide, within the watershed boundaries and by land use category, a quantitative measure of the amount of land, in square kilometers and acres. This quantitative measure of land use in watersheds is essential to the development and application of deterministic models, which compute nutrient flows into lakes and establish lake eutrophication rates
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