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in publisher: "CALIFORNIA INSTITUTE OF TECHNOLOGY"  
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Thermally Induced Structural Changes in Coal Combustion

Description: The effect of particle shape on char burnout is investigated in the limit of shrinking core combustion. As a first step, the particle temperature is assumed to proceed in the shrinking core regime and under conditions of negligible Stefan flow. The problem then reduces to calculating the oxygen concentration field around a non-spherical particle with the oxidation reaction taking place on the external surface. This problem has been addressed by an analytical technique and a numerical technique.… more
Date: January 17, 1990
Creator: Gavalas, G. R. & Flagan, R. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Simulation experiments and solar wind sputtering

Description: In order to isolate the role played by solar wind sputtering from other lunar surface phenomena a number of simulation experiments were performed, including isotope abundance measurements of Ca sputtered from terrestrial fluorite and plagioclase by 50-keV and 130-keV /sup 14/N beams, measurement of the energy distribution of U atoms sputtered with 80-keV /sup 40/Ar, and measurement of the fraction of sputtered U atoms which stick on the surfaces used to collect these atoms. 10 references. (JFP)
Date: January 1, 1978
Creator: Griffith, J. E.; Papanastassiou, D. A.; Russell, W. A.; Tombrello, T. A. & Weller, R. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Stress-Relief Displacements Induced by Drilling--Applications to Holographic Measurements of in Situ Stress

Description: The holographic stressmeter is an instrument which has been developed at Caltech to allow determination of the complete stress tensor from in situ borehole measurements. The stressmeter uses double-exposure holographic interferometry to record the displacements induced by the drilling of a small sidehole into the borehole wall. The local stresses, which are the result of the far-field stresses, concentrated at the borehole, cause deformation of the surface of the borehole wall in the vicinity o… more
Date: April 24, 1992
Creator: Ahrens, T. J. & Smither, C. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Infrared Spectroscopy and Hydrogen Isotope Geochemistry of Hydrous Silicate Glasses

Description: The focus of this project is the combined appication of infrared spectroscopy and stable isotope geochemistry to the study of hydrogen-bearing species dissolved in silicate melts and glasses. We are conducting laboratory experiments aimed at determining the fractionation of D and H between melt species (OH and H{sub 2}O) and hydrous vapor and the diffusivities of these species in glasses and melts. Knowledge of these parameters is critical to understanding the behavior of hydrogen isotopes duri… more
Date: January 1, 1992
Creator: Epstein, S. & Stolper, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Emerging supercomputer architectures

Description: This paper will examine the current and near future trends for commercially available high-performance computers with architectures that differ from the mainstream ''supercomputer'' systems in use for the last few years. These emerging supercomputer architectures are just beginning to have an impact on the field of high performance computing. 7 refs., 1 tab.
Date: January 1, 1987
Creator: Messina, P. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS - REPORTING PERIOD AUGUST 1, 2007-OCTOBER 31, 2007

Description: We have developed a forward modeling technique to retrieve rupture characteristics of small earthquakes (3<M<5), including rupture propagation direction, fault dimension, and rupture speed.
Date: September 30, 2007
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Next Generation Integrated Environment for Collaborative Work Across Internets

Description: We are now well-advanced in our development, prototyping and deployment of a high performance next generation Integrated Environment for Collaborative Work. The system, aimed at using the capability of ESnet and Internet2 for rapid data exchange, is based on the Virtual Room Videoconferencing System (VRVS) developed by Caltech. The VRVS system has been chosen by the Internet2 Digital Video (I2-DV) Initiative as a preferred foundation for the development of advanced video, audio and multimedia c… more
Date: February 24, 2009
Creator: Newman, Harvey B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Isotope Tracer Studies of Diffusion in Sillicates and of Geological Transport Processes Using Actinide Elements

Description: The objectives were directed toward understanding the transport of chemical species in nature, with particular emphasis on aqueous transport in solution, in colloids, and on particles. Major improvements in measuring ultra-low concentrations of rare elements were achieved. We focused on two areas of studies: (1) Field, laboratory, and theoretical studies of the transport and deposition of U, Th isotopes and their daughter products in natural systems; and (2) Study of calcium isotope fractionati… more
Date: July 31, 2008
Creator: Wasserburg, Gerald J
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Bio-Engineering High Performance Microbial Strains for MEOR

Description: The main objectives of this three-year research project are: (1) to employ the latest advances in genetics and bioengineering, especially Directed Protein Evolution technology, to improve the effectiveness of the microbial enhanced oil recovery (MEOR) process. (2) to improve the surfactant activity and the thermal stability of bio-surfactant systems for MEOR; and (3) to develop improved laboratory methods and tools that screen quickly candidate bio-systems for EOR. Biosurfactants have been rece… more
Date: December 30, 2007
Creator: Fang, Xiangdong; Wang, Qinghong & Shuler, Patrick
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs

Description: This report summarizes work during the 30 month time period of this project. This was planned originally for 3-years duration, but due to its financial limitations, DOE halted funding after 2 years. The California Institute of Technology continued working on this project for an additional 6 months based on a no-cost extension granted by DOE. The objective of this project is to improve the performance of aqueous phase formulations that are designed to increase oil recovery from fractured, oil-we… more
Date: September 30, 2007
Creator: Goddard, William A.; Tang, Yongchun; Shuler, Patrick; Blanco, Mario & Wu, Yongfu
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigations of Solar Prominence Dynamics Using Laboratory Simulations

Description: Laboratory experiments simulating many of the dynamical features of solar coronal loops have been carried out. These experiments manifest collimation, kinking, jet flows, and S-shapes. Diagnostics include high-speed photography and x-ray detectors. Two loops having opposite or the same magnetic helicity polarities have been merged and it is found that counter-helicity merging provides much greater x-ray emission. A non-MHD particle orbit instability has been discovered whereby ions going in the… more
Date: May 28, 2008
Creator: Bellan, Paul M
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Description: Earthquake source parameters underpin several aspects of nuclear explosion monitoring. Such aspects are: calibration of moment magnitudes (including coda magnitudes) and magnitude and distance amplitude corrections (MDAC); source depths; discrimination by isotropic moment tensor components; and waveform modeling for structure (including waveform tomography). This project seeks to improve methods for and broaden the applicability of estimating source parameters from broadband waveforms using the… more
Date: June 17, 2008
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Understanding the Fundamental Properties of Dark Matter & Dark Energy in Structure formation and Cosmology

Description: This program is concerned with developing and verifying the validityof observational methods for constraining the properties of dark matter and dark energy in the universe. Excellent progress has been made in comparing observational projects involving weak gravitational lensing using both ground and space-based instruments, in further constraining the nature of dark matter via precise measures of its distribution in clusters of galaxies using strong gravitational lensing, in demonstrating the p… more
Date: February 1, 2008
Creator: Ellis, Richard, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Description: The recent Nevada Earthquake (M=6) produced an extraordinary set of crustal guided waves. In this study, we examine the three-component data at all the USArray stations in terms of how well existing models perform in predicting the various phases, Rayleigh waves, Love waves, and Pnl waves. To establish the source parameters, we applied the Cut and Paste Code up to distance of 5° for an average local crustal model which produced a normal mechanism (strike=35°,dip=41°,rake=-85°) at a depth of 9 k… more
Date: April 15, 2008
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Description: We conduct a detailed test of a recently developed technique, CAPloc, in recovering source parameters from a few stations against results from a large broadband network. The method uses a library of 1D Green’s functions which are broken into segments and matched to waveform observations with adjustable timing shifts. These shifts can be established by calibration against a distribution of well-located earthquake and assembled in tomographic images for predicting various phase-delays. Synthetics… more
Date: December 10, 2007
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Bluff Body Flow Simulation Using a Vortex Element Method

Description: Heavy ground vehicles, especially those involved in long-haul freight transportation, consume a significant part of our nation's energy supply. it is therefore of utmost importance to improve their efficiency, both to reduce emissions and to decrease reliance on imported oil. At highway speeds, more than half of the power consumed by a typical semi truck goes into overcoming aerodynamic drag, a fraction which increases with speed and crosswind. Thanks to better tools and increased awareness, re… more
Date: September 30, 2004
Creator: Leonard, Anthony; Chatelain, Phillippe & Rebel, Michael
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermally Induced Structural Changes in Coal Combustion

Description: The project objectives are (1) to measure the effect of devolatilization temperature and time on properties of the char and (2) characterize and quantify the effect of thermal annealing on char reactivity during char burnout under conditions of pulverized combustion. Coal devolatilization runs continued during the reporting period. Elemental analysis and N{sub 2} BET surface areas measurements were carried out on the three chars produced in the devolatilization runs. The results are presented. … more
Date: December 7, 1990
Creator: Gavalas, G. R. & Flagan, R. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

(Fundamental Electron Transfer Processes at the Single Crystal Semiconductor/Liquid Interface)

Description: The last year's work has focused on several aspects of the fundamental chemistry and physics semiconductor/liquid junction behavior. These projects have been directed primarily towards GaAs/liquid contacts, because GaAs/liquid systems provide high energy conversion efficiencies and offer an opportunity to gain mechanistic understanding of the factors that are important to control in an efficient photoelectrochemical energy conversion system.
Date: January 1, 1991
Creator: Lewis, N. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Modeling for Process Control

Description: Significant developments have taken place in the control field during the last decade but their impact on industrial control practice has fallen far short of their full potential. One key difficulty that stands in the way of these new techniques is the need for process models. Work to be carried out under this grant aims at the development of a broad range of novel modeling and identification techniques which specifically address both information requirements of the new control analysis and des… more
Date: January 1, 1991
Creator: Morari, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Shock temperatures in metals. Final report, March 29, 1977-September 30, 1978

Description: A system for measurement of the spectral radiace of materials shocked to high pressures (approx. 100 GPa) by impact using a light-gas gun is described. Thermal radiation from the sample is sampled at six wavelength bands in the visible spectrum, and each signal is separately detected by solid state photodiodes and recorded with a time resolution of approx. 10 ns. Interpretation of the records in terms of temperature of transparent sample materials is discussed. Results of a series of explorator… more
Date: January 1, 1978
Creator: Ahrens, T.J. & Lyzenga, G.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

SiO sub 2 Membranes for H sub 2 Separation in Coal Gas Processing

Description: The project objectives are (1) to synthesize permselective ceramic membranes by chemical vapor deposition of SiO{sub 2} and other oxides within the walls of porous support tubes, (2) measure membrane permeability and thermal stability to various gases at 200--700{degrees}C and (3) develop a mathematical model for the chemical vapor deposition of the permselective oxide within the porous support tube.
Date: January 1, 1990
Creator: Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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