Facilities for meteorological research at NASA Goddard/Wallops Flight Facility

The technical characteristics of the Atmospheric Sciences Research Facility, the improvements being made to the instrumentation there which will enhance its usefulness in atmospheric research, and several of the on-going research programs are described. Among the area of atmospheric research discussed are clouds and precipitation, lightning, ozone, wind, and storms. Meteorological instruments including Doppler radar, spectrophotometers, and ozone sensors are mentioned. Atmospheric research relevant to aircraft design and COMSTAR communication satellites is briefly discussed

Consistent modeling of the geodetic precession in Earth rotation

A highly precise model for the motion of a rigid Earth is indispensable to reveal the effects of non-rigidity in the rotation of the Earth from observations. To meet the accuracy goal of modern theories of Earth rotation of 1 microarcsecond (muas) it is clear, that for such a model also relativistic effects have to be taken into account. The largest of these effects is the so called geodetic precession. In this paper we will describe this effect and the standard procedure to deal with it in modeling Earth rotation up to now. With our relativistic model of Earth rotation Klioner et al. (2001) we are able to give a consistent post-Newtonian treatment of the rotational motion of a rigid Earth in the framework of General Relativity. Using this model we show that the currently applied standard treatment of geodetic precession is not correct. The inconsistency of the standard treatment leads to errors in all modern theories of Earth rotation with a magnitude of up to 200 muas for a time span of one century.Comment: 6 pages, 4 figures, 1 table, published in the Proceedings of the VII Hotine-Marussi Symposium, Chapter 4

Charge carrier interaction with a purely electronic collective mode: Plasmarons and the infrared response of elemental bismuth

We present a detailed optical study of single crystal bismuth using infrared reflectivity and ellipsometry. Colossal changes in the plasmon frequency are observed as a function of temperature due to charge transfer between hole and electron Fermi pockets. In the optical conductivity, an anomalous temperature dependent mid-infrared absorption feature is observed. An extended Drude model analysis reveals that it can be connected to a sharp upturn in the scattering rate, the frequency of which exactly tracks the temperature dependent plasmon frequency. We interpret this absorption and increased scattering as the first direct optical evidence for a charge carrier interaction with a collective mode of purely electronic origin; here electron-plasmon scattering. The observation of a \emph{plasmaron} as such is made possible only by the unique coincidence of various energy scales and exceptional properties of semi-metal bismuth.Comment: 4 pages, 4 figure

Design and development criteria for metal bellows

Experimental research describes fluid flow and the fluid-elastic mechanism causing bellows flow excitation, and aids in design of conventional bellows liner which suppresses flow-induced vibrations. Analytical models facilitate prediction of flow excitation occurrence and estimation of severity of bellows vibrations

Stimulation of endothelial adenosine Al receptors enhances adhesion of neutrophils in the intact guinea pig coronary system

Objective: The primary aim was to determine the action of pathophysiologically relevant adenosine concentrations (0.1-1 μM) on adhesion of neutrophils to coronary endothelium. Further aims were to evaluate the nature and localisation of the adenosine receptor involved. and to assess the effect of endogenous adenosine. Methods: Adhesion was studied in isolated perfused guinea pig hearts by determining the number of cells emerging in the coronary effluent after intracoronary bolus injections of 600 000 neutrophils prepared from guinea pig or human blood. The system was characterised by the use of the proadhesive stimulus thrombin. Results: A 5 rnin infusion of adenosine (0.1-0.3 μM) or the A1 receptor agonist N6-cyclopentyladenosine (CPA, 0.01 μM) significantly increased adhesion from about 20% (control) to 30%. This effect was prevented by the A1 receptor antagonist dipropyl-8-cyclopentylxanthine (DPCPX. 0.1 μM). It was not diminished by cessation of adenosine infusion 90 s prior to neutrophil injection. At a higher concentration of adenosine (1 μM), adhesion did not seem to be enhanced. However, coinfusion of the A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine (DMPX. 0.1 μM) with 1 μM adenosine unmasked the A1 action, adhesion rising to 39%. Adenosine had a quantitatively identical effect on adhesion of human neutrophils. Total ischaemia of 15 min duration raised adhesion of subsequently applied neutrophils to 35%. This effect was completely blocked by DPCPX, as well as by ischaemic preconditioning (3 X 3 min). Preconditioning raised initial postischaemic coronary effluent adenosine from about 0.8 μM to 1.5 μM. Conclusions: The findings suggest a bimodal participation of adenosine in the development of postischaemic dysfunction by an endothelium dependent modulation of neutrophil adhesion. Stimulation occurs via endothelial A1 receptors at submicromolar adenosine levels, whereas cardioprotection by adenosine may in part relate to the use of pharmacologically high concentrations of adenosine or enhanced endogenous production after preconditioning

Quantum Mechanical Carrier of the Imprints of Gravitation

We exhibit a purely quantum mechanical carrier of the imprints of gravitation by identifying for a relativistic system a property which (i) is independent of its mass and (ii) expresses the Poincare invariance of spacetime in the absence of gravitation. This carrier consists of the phase and amplitude correlations of waves in oppositely accelerating frames. These correlations are expressed as a Klein-Gordon-equation-determined vector field whose components are the ``Planckian power'' and the ``r.m.s. thermal fluctuation'' spectra. The imprints themselves are deviations away from this vector field.Comment: 8 pages, RevTex. Html version of this and related papers on accelerated frames available at http://www.math.ohio-state.edu/~gerlac