Month

Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction (open access)

Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction

The purpose of this work is to investigate the kinetics-assisted design, synthesis and characterization of fine-particle, unsupported catalysts for coal liquefaction. The goal is to develop a fundamental understanding of coal catalysis and catalysts that will, in turn, allow for the specification of a novel optical catalyst for coal liquefaction.
Date: March 23, 1992
Creator: Klein, Michael T. & Foley, Henry C.
Object Type: Report
System: The UNT Digital Library
Colorado State University Program for Developing, Testing, Evaluating and Optimizing Solar Heating and Cooling Systems (open access)

Colorado State University Program for Developing, Testing, Evaluating and Optimizing Solar Heating and Cooling Systems

The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems, (2) a project to build and test several generic solar water heaters, (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems, (4) a liquid desiccant cooling system development project, (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research, and (6) a management task. The objectives and progress in each task are described in this report.
Date: March 23, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories (open access)

Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories

Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.
Date: March 23, 1992
Creator: Sharbaugh, R. C.
Object Type: Report
System: The UNT Digital Library
Correlation of fracture toughness with impurity components. Final contract report (open access)

Correlation of fracture toughness with impurity components. Final contract report

This investigation was sponsored by the Los Alamos National Laboratory in an effort to understand better the phenomenon of stress assisted diffusion in cracked structures operating in corrosive environments. Work done on the extension of the existing ``Coupled Thermomechanical Diffusion`` theory to enable the prediction of diffusion of a solute species in stressed solids in the presence of cracks is presented here. Mathematical formalism is provided to support the intuitive notion that a singular solution for the concentration field can exist in crack tip neighborhoods driven by singular solutions for stresses that have been obtained within the framework of classical Linear Elastic Fracture Mechanics. It has been shown that under certain limiting assumptions, a singular solution for the concentration profile of the kind 1/{radical}r emerges from the governing equations. Both steady state and transient solutions were obtained. A numerical simulation using quarter point finite elements was carried out and the results obtained also indicated the presence of this singularity. A singular solution for the concentration profiles of diffusing species in crack tip neighborhoods was obtained by Gdoutos and Aifantis. The order of the singularity obtained in their investigation was different from that discovered in the present work as were the …
Date: March 23, 1992
Creator: Subramanian, K. & Smith, F. W.
Object Type: Report
System: The UNT Digital Library
Colorado State University Program for Developing, Testing, Evaluating and Optimizing Solar Heating and Cooling Systems. Project Status Report, January--February 1992 (open access)

Colorado State University Program for Developing, Testing, Evaluating and Optimizing Solar Heating and Cooling Systems. Project Status Report, January--February 1992

The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems, (2) a project to build and test several generic solar water heaters, (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems, (4) a liquid desiccant cooling system development project, (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research, and (6) a management task. The objectives and progress in each task are described in this report.
Date: March 23, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories. Aerospace Nuclear Safety Program (open access)

Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories. Aerospace Nuclear Safety Program

Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth`s atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.
Date: March 23, 1992
Creator: Sharbaugh, R. C.
Object Type: Report
System: The UNT Digital Library
Two-phase flow modeling with discrete particles (open access)

Two-phase flow modeling with discrete particles

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for …
Date: March 23, 1992
Creator: Mortensen, G. A. & Trapp, J. A.
Object Type: Article
System: The UNT Digital Library
Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction. Technical progress report, October 26, 1991--January 25, 1992: Draft (open access)

Design, synthesis, and characterization of novel fine-particle, unsupported catalysts for coal liquefaction. Technical progress report, October 26, 1991--January 25, 1992: Draft

The purpose of this work is to investigate the kinetics-assisted design, synthesis and characterization of fine-particle, unsupported catalysts for coal liquefaction. The goal is to develop a fundamental understanding of coal catalysis and catalysts that will, in turn, allow for the specification of a novel optical catalyst for coal liquefaction.
Date: March 23, 1992
Creator: Klein, M. T. & Foley, H. C.
Object Type: Report
System: The UNT Digital Library
Two-phase flow modeling with discrete particles (open access)

Two-phase flow modeling with discrete particles

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for …
Date: March 23, 1992
Creator: Mortensen, G. A. & Trapp, J. A.
Object Type: Article
System: The UNT Digital Library