Chaotic transients and fractal structures governing coupled swing dynamics

Numerical simulations are used to study coupled swing equations modeling the dynamics of two electric generators connected to an infinite bus by a simple transmission network. In particular, the effect of varying parameters corresponding to the input power supplied to each generator is studied. In addition to stable steady operating conditions, which should correspond to synchronized, normal operation, the coupled swing model has other stable states of large amplitude oscillations which, if realized, would represent non-synchronized motions: the phase space boundary separating their basins of attraction is fractal, corresponding to chaotic transient motions. These fractal structures in phase space and the associated fractal structures in parameter space will be of primary concern to engineers in predicting system behavior

Observations of tornadoes and wall clouds with a portable FM-CW Doppler radar: 1989--1990 results

The purpose of this paper is to report on our progress using a portable, 1 W,FM (frequency modulated)-CW (continuous wave) Doppler radar developed at the Los Alamos National Laboratory (LANL), to make measurements of the wind field in tornadoes and wall clouds along with simultaneous visual documentation. Results using a CW version of the radar in 1987--1988 are given in Bluestein and Unruh (1989). 18 refs., 2 figs., 1 tab

Atomic and molecular data for fusion Part 1: recommended cross sections and rates for electron ionisation of light atoms and ions

6.00SIGLELD:9091.9F(CIM-R--216). / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A differential thermal analysis study of the effect of tramp impurities on the exothermic U sub 3 O sub 8 -Al reactions

Differential thermal analysis (DTA) has been used to study the effect of impurities on aluminothermic reactions between commercial type 101 aluminum powder and U{sub 3}O{sub 8} powder. No measurable effect (solid state reactions) was found below 660{degrees}C during differential thermal analysis studies of (1) loose blended powders, (2) blended and compressed powders, (3) blended, heated, and compressed powders, or (4) blended, compressed, and heated compacts containing less than 50,000 ppM impurities from group IA halide salts and group IIA oxides. It was determined that impurities (>5 wt %) of alkali metal chlorides, and alkaline earth oxides, cause minor modifications of the reaction thermograms above 800{degrees}C for molten aluminum metal with U{sub 3}O{sub 8}. It was also determined that attempts to prepare alkali, alkaline earth, and transition metal uranates under conditions via reaction below 660{degrees}C. In similar experiments where Fe{sub 2}O{sub 3} and NiO were substituted for U{sub 3}O{sub 8}, it was determined that NaCl does modify the reactions between aluminum metal and Fe{sub 2}O{sub 3} and between aluminum metal and NiO. With increasing NaCl concentrations, the temperature for initiation of the reaction moves to lower temperatures. At 10 wt % NaCl, the exothermic thermite'' reactions between aluminum and Fe{sub 2}O{sub 3} or NiO begin at approximately 640{degrees}C. 30 refs., 17 figs., 7 tabs

On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamos National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs

FE-Stirnradkette. Beanspruchungen und Sicherheiten von Stirnraedern mit der Methode finiter Elemente Abschlussbericht

SIGLEAvailable from TIB Hannover: RN 3358(322) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Wirtschaft, Bonn (Germany); Arbeitsgemeinschaft Industrieller Forschungsvereinigungen e.V., Koeln (Germany)DEGerman

Atomic and molecular data for fusion, part 2 Recommended cross sections and rates for electron ionisation of atoms and ions; fluorine to nickel

10.00SIGLEAvailable from British Library Document Supply Centre- DSC:9091.9F(CLM-R--270) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL's fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure

Progress in the chemistry of chromium(V) doping agents used in polarized target materials

We wish to report progress in two areas of the chromium (V)-based doping agents: Two commonly used chromium (V) complexes, I and II, have been synthesized in perdeuterated form (i.e., all hydrogens replaced by deuterium). They are sodium bis(2-ethyl-2-deuteroxy-butyrato)oxochromate(V)monodeuterate, IV, (acronym EDBA-Cr(V)), and sodium bis(2-deuteroxy-2-methylpropionato)oxochromate(V), III, (acronym DMPA-Cr(V)). A synthetic route leading to the preparation of stable, chromium(III)-free solutions of chromium(V) in diols (1,2-ethanediol/ethylene glycol/and 1,2-propanediol/propylene glycol/) has been outlined