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Japanese power electronics inverter technology and its impact on the American air conditioning industry

Description: Since 1983, technological advances and market growth of inverter- driven variable-speed heat pumps in Japan have been dramatic. The high level of market penetration was promoted by a combination of political, economic, and trade policies in Japan. A unique environment was created in which the leading domestic industries-- microprocessor manufacturing, compressors for air conditioning and refrigerators, and power electronic devices--were able to direct the development and market success of inverter-driven heat pumps. As a result, leading US variable-speed heat pump manufacturers should expect a challenge from the Japanese producers of power devices and microprocessors. Because of the vertically-integrated production structure in Japan, in contrast to the out-sourcing culture of the United States, price competition at the component level (such as inverters, sensors, and controls) may impact the structure of the industry more severely than final product sales. 54 refs., 47 figs., 1 tab.
Date: August 1, 1990
Creator: Ushimaru, Kenji.
Partner: UNT Libraries Government Documents Department

The energy stabilization for the SLC scavenger beam

Description: The energy of the SLC scavenger beam which is used to produce positrons must be carefully maintained so that the beam can be transported through the collimators in the dispersive region of the extraction line which leads from the Linac to the positron target. A feedforward control loop has been developed to compensate the energy fluctuations due to the beam intensity fluctuations. The loop detects the beam intensities in the damping rings and then calculates how much energy needs to be compensated due to beam loading effects. The energy is corrected by adjusting the acceleration phases of two sets of klystrons right before the extraction. Because there is feedback loop using the same controls, their interaction needs to be carefully treated. This paper presents an overview of the feedforward algorithms. 3 figs.
Date: August 1, 1990
Creator: Hsu, Ian; Browne, M.; Himel, T.; Humphrey, R.; Jobe, K.; Ross, M. et al.
Partner: UNT Libraries Government Documents Department

Nucleosynthesis in a baryon-inhomogeneous universe with coupled baryon diffusion

Description: Detailed calculations of big-bang nucleosynthesis in baryon-inhomogeneous universes show that {Omega}{sub b} can be considerably larger than its limit from standard big-bang nucleosynthesis. Such results require that late-time hydrodynamic effects deplete overproduction of {sup 7}Li and that the QCD surface tension be near the cube of the QCD coexistence temperature for fluctuations of the correct length scales to arise. 15 refs., 1 fig.
Date: August 2, 1990
Creator: Meyer, B.S.
Partner: UNT Libraries Government Documents Department

Global climate feedbacks: Conclusions and recommendations of the June 1990 BNL workshop

Description: The issue of global change initiated by increases in the concentrations of CO{sub 2} and other greenhouse gases is a scientific issue with major policy implications. The best means to examine the response of the Earth's climate to prospective perturbations in radiative forcing caused by such changes, and to other industrial activities, is modeling, specifically by means of general circulation models (GCMs) of the Earth's atmosphere and of the coupled atmosphere-ocean system. The purpose of this workshop was to identify the feedbacks inherent in the Earth's climate that actually or potentially govern the system's response to perturbations, to identify gaps in knowledge that preclude the accurate representation of these feedbacks in models, and to identify research required to represent these feedbacks accurately in models.
Date: August 1, 1990
Creator: Manowitz, B.
Partner: UNT Libraries Government Documents Department

Simulation of seasonal cloud forcing anomalies

Description: One useful way to classify clouds is according to the processes that generate them. There are three main cloud-formation agencies: deep convection; surface evaporation; large-scale lifting in the absence of conditional instability. Although traditionally clouds have been viewed as influencing the atmospheric general circulation primarily through the release of latent heat, the atmospheric science literature contains abundant evidence that, in reality, clouds influence the general circulation through four more or less equally important effects: interactions with the solar and terrestrial radiation fields; condensation and evaporation; precipitation; small-scale circulations within the atmosphere. The most advanced of the current generation of GCMs include parameterizations of all four effects. Until recently there has been lingering skepticism, in the general circulation modeling community, that the radiative effects of clouds significantly influence the atmospheric general circulation. GCMs have provided the proof that the radiative effects of clouds are important for the general circulation of the atmosphere. An important concept in analysis of the effects of clouds on climate is the cloud radiative forcing (CRF), which is defined as the difference between the radiative flux which actually occurs in the presence of clouds, and that which would occur if the clouds were removed but the atmospheric state were otherwise unchanged. We also use the term CRF to denote warming or cooling tendencies due to cloud-radiation interactions. Cloud feedback is the change in CRF that accompanies a climate change. The present study concentrates on the planetary CRF and its response to external forcing, i.e. seasonal change.
Date: August 1, 1990
Creator: Randall, D. A.
Partner: UNT Libraries Government Documents Department

Natural Current Profiles in a Tokamak

Description: In this paper I show how one may arrive at a universal, or natural, family of Tokamak profiles using only accepted physical principles. These particular profiles are similar to ones proposed previously on the basis of ad hoc variational principles and the point of the present paper is to provide a justification for them. However in addition, the present work provides an interesting view of Tokamak fluctuations and leads to a new result -- a relationship between the inward particle pinch velocity, the diffusion coefficient and the current profile. The basic Tokamak model is described in this paper. Then an analogy is developed between Tokamak profiles and the equilibrium of a realisable dynamical system. Then the equations governing the natural Tokamak profiles are derived by applying standard statistical mechanics to this analog. The profiles themselves are calculated and some other results of the theory are described.
Date: August 1, 1990
Creator: Taylor, J. B.
Partner: UNT Libraries Government Documents Department

Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation

Description: The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.
Date: August 1, 1990
Creator: Riordan, C.J.; Hulstrom, R.L. & Myers, D.R.
Partner: UNT Libraries Government Documents Department

Simulation of seasonal cloud forcing anomalies

Description: One useful way to classify clouds is according to the processes that generate them. There are three main cloud-formation agencies: deep convection; surface evaporation; large-scale lifting in the absence of conditional instability. Although traditionally clouds have been viewed as influencing the atmospheric general circulation primarily through the release of latent heat, the atmospheric science literature contains abundant evidence that, in reality, clouds influence the general circulation through four more or less equally important effects: interactions with the solar and terrestrial radiation fields; condensation and evaporation; precipitation; small-scale circulations within the atmosphere. The most advanced of the current generation of GCMs include parameterizations of all four effects. Until recently there has been lingering skepticism, in the general circulation modeling community, that the radiative effects of clouds significantly influence the atmospheric general circulation. GCMs have provided the proof that the radiative effects of clouds are important for the general circulation of the atmosphere. An important concept in analysis of the effects of clouds on climate is the cloud radiative forcing (CRF), which is defined as the difference between the radiative flux which actually occurs in the presence of clouds, and that which would occur if the clouds were removed but the atmospheric state were otherwise unchanged. We also use the term CRF to denote warming or cooling tendencies due to cloud-radiation interactions. Cloud feedback is the change in CRF that accompanies a climate change. The present study concentrates on the planetary CRF and its response to external forcing, i.e. seasonal change.
Date: August 1, 1990
Creator: Randall, D. A.
Partner: UNT Libraries Government Documents Department

Scattering by anisotropic grains in beryllium mirrors

Description: Scattering from mirror surfaces arises from topographic and non-topographic sources. This paper considers the nontopographic scattering of beryllium mirrors modelled as a collection of randomly oriented bireflective grains. Simple scattering theory shows that this type of scatting scales as {lambda}{sup {minus}2}, rather than as {lambda}{sup {minus}4} for topographic scattering, which means that it is relatively more important at long radiation wavelengths. Estimates of the intensity based an available short-wavelength values of the anisotropic optical constants of beryllium indicate that this type of scattering could dominate the topographic scattering from smooth surfaces at CO{sub 2} wavelengths. 10 refs., 2 figs.
Date: August 1, 1990
Creator: Church, E.L. (Army Armament Research and Development Command, Dover, NJ (USA)); Takacs, P.Z. (Brookhaven National Lab., Upton, NY (USA)) & Stover, J.C. (TMA Technologies, Inc., Bozeman, MT (USA))
Partner: UNT Libraries Government Documents Department