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Unifying factors in erosion and wear of machine elements

Description: Some observations of erosion in ceramics are presented and these observations are discussed in terms of basic wear mechanisms. In particular, the damage introduced at single particle impacts on several ceramics is presented and discussed in terms of the operative wear mechanism(s). Erosion has been a fact of life for some time, but technical interest in the subject has been stimulated in recent years by aerospace, aircraft, and power equipment requirements. Most recently, erosion problems assoc… more
Date: January 1, 1978
Creator: Yust, C. S.
Item Type: Refine your search to only Article
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Unifying physical concepts of reality

Description: Physics may be characterized as the science of matter and energy. It anchors the two ends of the frontiers of science: the frontier of the very small and the frontier of the very large. All of the phenomena that we observe and study at the frontiers of science - all external experiences - are manifestations of matter and energy. One may, therefore, use physics to exemplify both the diversity and unity of science. This theme will be developed in two separate examples: first by sketching, very br… more
Date: August 1, 1983
Creator: Gilbert, T. L.
Item Type: Refine your search to only Article
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Unifying the controlling mechanisms for the critical heat flux and quenching: The ability of liquid to contact the hot surface

Description: We investigate the hypothesis that the critical heat flux (CHF) occurs when some point on a heated surface reaches a temperature high enough so that liquid can no longer maintain contact at that point, resulting in a gradual but continuous increase in the overall surface temperature. This hypothesis unifies the occurrence of the CHF with the quenching of hot surfaces by relating them to the same concept: the ability of a liquid to contact a hot surface, generally defined as some fraction of liq… more
Date: January 1, 1990
Creator: Unal, C.; Daw, V. & Nelson, R.A.
Item Type: Refine your search to only Article
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Unifying the controlling mechanisms for the critical heat flux and quenching: The ability of liquid to contact the hot surface. Part 3, The influence of dry-patch shape and multiple-patch interaction

Description: In earlier work, we proposed a hypothesis for the occurrence of critical heat flux (CHF) during pool boiling of saturated liquids. According to this gypothesis, CHF occurs when some portion of the heater surface drives and a local point with this dry patch reaches a critical rewetting temperature, beyond which liquid an no longer contact that point. In this paper, the effects of dry-patch shape and multiple-patch interactions on the critical rewetting temperature have been investigated.
Date: July 1, 1993
Creator: Unal, C.; Sadasivan, P. & Nelson, R. A.
Item Type: Refine your search to only Article
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Unimolecular and bimolecular reactions induced by state-specific vibrational excitation

Description: Toward the goal of understanding the role of vibrational energy in chemical reactions related to energy production, we have made several advances. They include the understanding of chemical properties of highly vibrationally excited molecules, the characterization of vibrationally excited radicals, and the development of experimental techniques to extend our ability to investigate transient and reactive chemical species. 11 refs., 1 fig.
Date: November 1, 1991
Creator: Dai, Hai-Lung.
Item Type: Refine your search to only Report
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Unimolecular and bimolecular reactions induced by state-specific vibrational excitation. Progress report

Description: Toward the goal of understanding the role of vibrational energy in chemical reactions related to energy production, we have made several advances. They include the understanding of chemical properties of highly vibrationally excited molecules, the characterization of vibrationally excited radicals, and the development of experimental techniques to extend our ability to investigate transient and reactive chemical species. 11 refs., 1 fig.
Date: November 1, 1991
Creator: Dai, Hai-Lung
Item Type: Refine your search to only Report
open access

Unimolecular decay dynamics of internal energy selected molecules. Technical progress report. [Tetramethyldioxetane]

Description: Direct excitation of overtone vibrations in combination with time-resolved spectroscopic detection probes unimolecular processes in new detail. Observing product luminescence produced by the decay of tetramethyldioxetane excited to v = 3, 4, or 5 of the CH stretching vibration yields the unimolecular decay rate directly, provides overtone vibration spectra on a low pressure gas phase molecule, and reveals a new feature to the chemiluminescence kinetics. Laser induced fluorescence experiments to… more
Date: January 1, 1980
Item Type: Refine your search to only Report
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Unimolecular decomposition of methyltrichlorosilane: RRKM calculations

Description: Based on reaction thermochemistry and estimates of Arrhenius A-factors, it is expected that Si-C bond cleavage, C-H bond cleavage, and HCl elimination will be the primary channels for the unimolecular decomposition of methyltrichlorosilane. Using RRKM theory, we calculated rate constants for these three reactions. The calculations support the conclusion that these three reactions are the major decomposition pathways. Rate constants for each reaction were calculated in the high-pressure limit (8… more
Date: June 1, 1993
Creator: Osterheld, T. H.; Allendorf, M. D. & Melius, C. F.
Item Type: Refine your search to only Report
open access

Unimolecular photodissociation dynamics of ketene (CH{sub 2}CO): The singlet/triplet branching ratio and experimental observation of the vibrational level thresholds of the transition-state

Description: The rotational distributions of CO products from the dissociation of ketene at photolysis energies 10 cm{sup {minus}1} below, 56, 110, 200, 325, 425, 1,107, 1,435, 1,720, and 2,500 cm{sup {minus}1} above the singlet threshold, are measured in a supersonic free jet of ketene. The CO(v{double_prime} = 0) rotational distributions at 56, 110, 200, 325, and 425 cm{sup {minus}1} are bimodal. The peaks at low J`s, which are due to CO from the singlet channel, show that the product rotational distribut… more
Date: May 1, 1993
Creator: Kim, S. K.
Item Type: Refine your search to only Thesis or Dissertation
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Unimolecular reaction dynamics of free radicals

Description: Free radical reactions are of crucial importance in combustion and in atmospheric chemistry. Reliable theoretical models for predicting the rates and products of these reactions are required for modeling combustion and atmospheric chemistry systems. Unimolecular reactions frequently play a crucial role in determining final products. The dissociations of vinyl, CH2= CH, and methoxy, CH3O, have low barriers, about 13,000 cm-1 and 8,000 cm-1, respectively. Since barriers of this magnitude are typi… more
Date: September 1, 2006
Creator: Miller, Terry A.
Item Type: Refine your search to only Report
open access

Unimolecular reaction dynamics of well characterized ionic reactions. Final report, 1993--1997

Description: The dissociation dynamics of well characterized and energy selected ions have been investigated by photoelectron photoion coincidence (PEPICO) spectrometry. A number of ions have been found which dissociate in competition with isomerization and which thus lead to multi-component decay rates. The dissociation dynamics on such complex potential energy surfaces are common for many free radical reactions, including some of importance to combustion processes. Individual reaction rates for isomerizat… more
Date: December 31, 1997
Creator: Baer, T.
Item Type: Refine your search to only Report
open access

Uninstrumented assembly airflow testing in the Annular Flow Distribution facility

Description: During the Emergency Cooling System phase of a postulated large-break loss of coolant accident (ECS-LOCA), air enters the primary loop and is pumped down the reactor assemblies. One of the experiments performed to support the analysis of this accident was the Annular Flow Distribution (AFD) experiment, conducted in a facility built for this purpose at Babcock and Wilcox Alliance Research Center in Alliance, Ohio. As part of this experiment, a large body of airflow data were acquired in a protot… more
Date: February 1, 1992
Creator: Kielpinski, A. L.
Item Type: Refine your search to only Report
open access

Unintended consequences of atmospheric injection of sulphate aerosols.

Description: Most climate scientists believe that climate geoengineering is best considered as a potential complement to the mitigation of CO{sub 2} emissions, rather than as an alternative to it. Strong mitigation could achieve the equivalent of up to -4Wm{sup -2} radiative forcing on the century timescale, relative to a worst case scenario for rising CO{sub 2}. However, to tackle the remaining 3Wm{sup -2}, which are likely even in a best case scenario of strongly mitigated CO{sub 2} releases, a number of … more
Date: October 1, 2010
Creator: Brady, Patrick Vane; Kobos, Peter Holmes & Goldstein, Barry
Item Type: Refine your search to only Report
open access

Uninterruptable power source for a large computer facility

Description: An uninterruptable power source was needed to protect critical elements of a computer complex from short power outages and glitches, many of them lightning related. A consultant was hired to help in this task and proved invaluable. The equipment purchased provides glitch-free power under many fault conditions. Installation proved to be a major problem as far as money and time were concerned. The system is now ready to be switched over to drive the critical load. The project appears to be a succ… more
Date: January 1, 1979
Creator: Barton, J. & Tolmie, D. E.
Item Type: Refine your search to only Article
open access

Uninterruptible power supply (UPS) systems

Description: Use of this purchase specification is not mandatory. User should review the document and determine if it meets the user`s purpose. This document contains a fill-in-the-blanks guide specification for the procurement of uninterruptible power supply (UPS) systems greater than 10 kVA, organized as follows: Parts 1 through 7--technical requirements; Appendix A--technical requirements to be included in the proposal; Appendix B--UPS system data sheets to be completed by each bidder (Seller) and submit… more
Date: April 1997
Item Type: Refine your search to only Report
open access

Union Carbide Nuclear Company Radiation Standards & Practices. Recommendations of the Committee on Radiation Standards & Practices

Description: Radiation practices among the 4 Carbide Plants at Oak Ridge, Tennessee, and Paducah, Kentucky, were evaluated, and uniform standards and criteria for handling U, Th, Np, and Pu were developed. Values for the permissible limits of internal and external radiation exposure published in the most current NCRP handbooks and FRC publications were adopted as the basic standards for all 4 plants. On the basis of these standards, the maximum permissible concentrations of U, Th, Np, and Pu in air and acti… more
Date: November 1, 1962
Creator: Levin, R. W.
Item Type: Refine your search to only Report
open access

Union County - La Grande, Oregon geothermal district heating: feasibility assessment. Final report

Description: This report presents an assessment of geothermal district heating in the City of La Grande, Oregon. Eight study area districts were analyzed to determine their economic feasibility. Results from the analyses conclude that certain districts within the City of La Grande are economically feasible if certain assumptions are correct. Development of geothermal district heating for these areas would provide direct energy and dollar savings to the building owners and would also provide direct and indir… more
Date: September 1, 1982
Creator: Jenkins, H. II; Giddings, M. & Hanson, P.
Item Type: Refine your search to only Report
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