Deactivation by Carbon of Iron Catalysts for Indirect Liquefaction (open access)

Deactivation by Carbon of Iron Catalysts for Indirect Liquefaction

This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the fourteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made towards testing of the system hardware and software. 47 refs.
Date: October 29, 1990
Creator: Bartholomew, C. H.
Object Type: Report
System: The UNT Digital Library
Effects of dispersion and support on adsorption, catalytic and electronic properties of cobalt/alumina Co hydrogenation catalysts. Final progress report, August 1, 1987--July 31, 1990 (open access)

Effects of dispersion and support on adsorption, catalytic and electronic properties of cobalt/alumina Co hydrogenation catalysts. Final progress report, August 1, 1987--July 31, 1990

An investigation of the effects of surface structure, dispersion, and support on the adsorption, catalytic, and electronic properties of cobalt/alumina is described, the objectives of which were to determine (1) the effects of surface structure and metal dispersion on the adsorption and catalytic properties of cobalt and (2) the effects of direct electronic interactions between metal clusters and support, on the adsorption, catalytic and electronic properties of cobalt supported on alumina. Effects of surface structure and dispersion on the adsorption, activity/selectivity, and electronic properties of Co/W single crystal surfaces and alumina-supported cobalt were investigated in a surface investigation, lab reactor studies, TPD/TPSR studies, and a Moessbauer spectroscopy study. The structure, stability, surface electronic properties, and chemisorptive properties of vapor-deposited cobalt overlayers (0-4 ML) on W(110) and W(100) were studied by Auger electron spectroscopy, low energy electron diffraction, work function changes, and temperature programmed desorption (TPD) of cobalt, hydrogen, and carbon monoxide. The CO chemisorptive properties of the two cobalt overlayers are quite different, CO adsorption being dissociative on the W(100) surface and nondissociative on the W(110) surface; comparison of the results with those for Ni/W(100) indicate that Co/W(100) dissociates CO as a result of electronic interaction with the tungsten substrate.
Date: September 29, 1990
Creator: Bartholomew, C. H.
Object Type: Report
System: The UNT Digital Library
Effects of dispersion and support on adsorption, catalytic and electronic properties of cobalt/alumina Co hydrogenation catalysts (open access)

Effects of dispersion and support on adsorption, catalytic and electronic properties of cobalt/alumina Co hydrogenation catalysts

An investigation of the effects of surface structure, dispersion, and support on the adsorption, catalytic, and electronic properties of cobalt/alumina is described, the objectives of which were to determine (1) the effects of surface structure and metal dispersion on the adsorption and catalytic properties of cobalt and (2) the effects of direct electronic interactions between metal clusters and support, on the adsorption, catalytic and electronic properties of cobalt supported on alumina. Effects of surface structure and dispersion on the adsorption, activity/selectivity, and electronic properties of Co/W single crystal surfaces and alumina-supported cobalt were investigated in a surface investigation, lab reactor studies, TPD/TPSR studies, and a Moessbauer spectroscopy study. The structure, stability, surface electronic properties, and chemisorptive properties of vapor-deposited cobalt overlayers (0-4 ML) on W(110) and W(100) were studied by Auger electron spectroscopy, low energy electron diffraction, work function changes, and temperature programmed desorption (TPD) of cobalt, hydrogen, and carbon monoxide. The CO chemisorptive properties of the two cobalt overlayers are quite different, CO adsorption being dissociative on the W(100) surface and nondissociative on the W(110) surface; comparison of the results with those for Ni/W(100) indicate that Co/W(100) dissociates CO as a result of electronic interaction with the tungsten substrate.
Date: September 29, 1990
Creator: Bartholomew, Calvin H.
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 July 1990--30 September 1990 (open access)

Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 July 1990--30 September 1990

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: October 29, 1990
Creator: Bukur, D. B.
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts (open access)

Development of improved iron Fischer-Tropsch catalysts

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: October 29, 1990
Creator: Bukur, D.B.
Object Type: Report
System: The UNT Digital Library
Theory and phenomenology of strong and weak interaction high energy physics (open access)

Theory and phenomenology of strong and weak interaction high energy physics

This paper deals with research being conducted at the University of Arizona in the theory of strong and weak interactions. Topics in Quantum chromodynamics, quantum electrodynamics, symmetry principle, hadronic structure of the photon and other are discussed. (LSP)
Date: August 29, 1990
Creator: Carruthers, P. & Thews, R. L.
Object Type: Report
System: The UNT Digital Library
Geophysical and transport properties of reservoir rocks. Summary annual report (open access)

Geophysical and transport properties of reservoir rocks. Summary annual report

Definition of petrophysical properties, such as porosity, permeability and fluid saturation, on the scale of meters, is the key to planning and control of successful Enhanced Oil Recovery techniques for domestic reservoirs. Macroscopic transport properties in reservoir rocks depend critically upon processes at the pore level involving interactions between the pore topology and the physical and chemical properties of the rock minerals and interstitial fluids. Similar interactions at the pore level determine also the macroscopic electrical and seismic properties of reservoir rocks. The objective of this research is to understand, using analysis and experiment, how fluids in pores affect the geophysical and sport properties of reservoir rocks. The goal is to develop equations-relating seismic and electrical properties of rock to the porosity, permeability and fluid saturations so as to invert geophysical images for improved reservoir management. Results from seismic measurements performed so far in this study suggest that even subtle changes in fluid contacts and the in-situ state of effective stress can be detected using geophysical imaging techniques. The experiments using Wood`s metal and wax are revealing the topology and sport properties of the pore space in clastic sedimentary rocks. A deeper understanding of these properties is considered-to be the …
Date: April 29, 1990
Creator: Cook, N. G. W.
Object Type: Report
System: The UNT Digital Library
Note on Sufficient Symmetry Conditions for Isotropy of the Elastic Moduli Tensor (open access)

Note on Sufficient Symmetry Conditions for Isotropy of the Elastic Moduli Tensor

Group theoretical methods are used to obtain the form of the elastic moduli matrices and the number of independent parameters for various symmetries. Particular attention is given to symmetry groups for which 3D and 2D isotropy is found for the stress-strain tensor relation. The number of independent parameters is given by the number of times the fully symmetric representation is contained in the direct product of the irreducible representations for two symmetrical second rank tensors. The basis functions for the lower symmetry groups are found from the compatibility relations and are explicitly related to the elastic moduli. These types of symmetry arguments should be generally useful in treating the elastic properties of solids and composites.
Date: August 29, 1990
Creator: Dresselhaus, M.S. & Dresselhaus, G. (Massachusetts Inst. of Tech., Cambridge, MA (USA))
Object Type: Report
System: The UNT Digital Library
Advanced design and modeling concepts for recombination x-ray lasers (open access)

Advanced design and modeling concepts for recombination x-ray lasers

Geometric, kinetic, and trapping issues, in short and ultrashort recombination x-ray lasers, are discussed. The design of a composite target consisting of a lasant strip on a plastic backing is described. Examples of modeling showing the effect of photon trapping and uncertainties in other physical processes on calculated gain coefficients are given. A simple and accurate expression for photon trapping in cylindrical geometry is presented. Recombination lasers that have the ground state as the lower laser state are shown to have small I{sub sat}'s and corresponding low efficiencies. Scaling laws for femtosecond laser-plasma interactions are presented. 19 refs.
Date: November 29, 1990
Creator: Eder, D.C.; Rosen, M.D.; Shephard, R.; Staffin, R.; Nash, J.K. & Keane, C.J.
Object Type: Article
System: The UNT Digital Library
Pulsed laser kinetic studies of liquids under high pressure (open access)

Pulsed laser kinetic studies of liquids under high pressure

A high pressure apparatus has been constructed for measuring rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm. This apparatus is being used to test the effect of ligand bulk on the rate of a thermal ring closure reaction. Microphonic photoacoustic signals obtained by illuminating solid samples with synchrotron soft x-rays and with visible laser beams have been successfully correlated with a theory for photoacoustic signal enhancement by volatile liquids. The concentration dependence of the fluorescence and nonradiative quantum yields for cresyl violet dissolved in methanol has been determined. Stability constants for complexes of lithium ion with four different crown ethers dissolved in a low temperature molten salt have been measured.
Date: November 29, 1990
Creator: Eyring, E.M.
Object Type: Report
System: The UNT Digital Library
SIMON Host Computer System requirements and recommendations (open access)

SIMON Host Computer System requirements and recommendations

Development Service Order {number_sign}90025 requested recommendations for computer hardware, operating systems, and software development utilities based on current and future SIMON software requirements. Since SIMON`s main objective is to be dispatched on missions by an operator with little computer experience, ``user friendly`` hardware and software interfaces are required. Other design criteria include: a fluid software development environment, and hardware and operating systems with minimal maintenance requirements. Also, the hardware should be expandable; extra processor boards should be easily integrated into the existing system. And finally, the use of well established standards for hardware and software should be implemented where practical.
Date: November 29, 1990
Creator: Harpring, L. J.
Object Type: Report
System: The UNT Digital Library
SIMON Host Computer System requirements and recommendations (open access)

SIMON Host Computer System requirements and recommendations

Development Service Order {number sign}90025 requested recommendations for computer hardware, operating systems, and software development utilities based on current and future SIMON software requirements. Since SIMON's main objective is to be dispatched on missions by an operator with little computer experience, user friendly'' hardware and software interfaces are required. Other design criteria include: a fluid software development environment, and hardware and operating systems with minimal maintenance requirements. Also, the hardware should be expandable; extra processor boards should be easily integrated into the existing system. And finally, the use of well established standards for hardware and software should be implemented where practical.
Date: November 29, 1990
Creator: Harpring, L.J.
Object Type: Report
System: The UNT Digital Library
Particle distributions in collisionless magnetic reconnection: An implicit Particle-In-Cell (PIC) description (open access)

Particle distributions in collisionless magnetic reconnection: An implicit Particle-In-Cell (PIC) description

Evidence from magnetospheric and solar flare research supports the belief that collisionless magnetic reconnection can proceed on the Alfven-wave crossing timescale. Reconnection behavior that occurs this rapidly in collisionless plasmas is not well understood because underlying mechanisms depend on the details of the ion and electron distributions in the vicinity of the emerging X-points. We use the direct implicit Particle-In-Cell (PIC) code AVANTI to study the details of these distributions as they evolve in the self-consistent E and B fields of magnetic reconnection. We first consider a simple neutral sheet model. We observe rapid movement of the current-carrying electrons away from the emerging X-point. Later in time an oscillation of the trapped magnetic flux is found, superimposed upon continued linear growth due to plasma inflow at the ion sound speed. The addition of a current-aligned and a normal B field widen the scope of our studies.
Date: June 29, 1990
Creator: Hewett, D. W.; Francis, G. E. & Max, C. E.
Object Type: Article
System: The UNT Digital Library
Process of making cryogenically cooled high thermal performance crystal optics (open access)

Process of making cryogenically cooled high thermal performance crystal optics

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.
Date: June 29, 1990
Creator: Kuzay, T. M.
Object Type: Patent
System: The UNT Digital Library
Process of making cryogenically cooled high thermal performance crystal optics (open access)

Process of making cryogenically cooled high thermal performance crystal optics

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.
Date: June 29, 1990
Creator: Kuzay, Tuncer M.
Object Type: Patent
System: The UNT Digital Library
Bit-string scattering theory (open access)

Bit-string scattering theory

We construct discrete space-time coordinates separated by the Lorentz-invariant intervals h/mc in space and h/mc{sup 2} in time using discrimination (XOR) between pairs of independently generated bit-strings; we prove that if this space is homogeneous and isotropic, it can have only 1, 2 or 3 spacial dimensions once we have related time to a global ordering operator. On this space we construct exact combinatorial expressions for free particle wave functions taking proper account of the interference between indistinguishable alternative paths created by the construction. Because the end-points of the paths are fixed, they specify completed processes; our wave functions are born collapsed''. A convenient way to represent this model is in terms of complex amplitudes whose squares give the probability for a particular set of observable processes to be completed. For distances much greater than h/mc and times much greater than h/mc{sup 2} our wave functions can be approximated by solutions of the free particle Dirac and Klein-Gordon equations. Using a eight-counter paradigm we relate this construction to scattering experiments involving four distinguishable particles, and indicate how this can be used to calculate electromagnetic and weak scattering processes. We derive a non-perturbative formula relating relativistic bound and resonant state energies …
Date: January 29, 1990
Creator: Noyes, H. P.
Object Type: Article
System: The UNT Digital Library
Reduction of multielement mass spectra (open access)

Reduction of multielement mass spectra

Even though the spectra obtained by inductively coupled plasma source spectrometry (ICP-MS) are relatively simple, their interpretation can be complicated by the presence of molecular and isobaric interferants. To the extent that isotopic abundances are known and constant, one can treat observed spectra as sums of known components. A linear decomposition approach for determining the concentrations of the components in a spectrum and correctly propagating uncertainties is presented. This technique differs from linear regression in that an exact fit is made to a subset of isotopes and goodness-of-fit is evaluated from the deviations between the predicted and measured intensities of the other, unfit isotopes. This technique can be applied to a wide range of spectral fitting problems. In this paper, its applicability to ICP-MS spectra is used to demonstrate the use and utility of the technique. 2 refs., 9 figs.
Date: June 29, 1990
Creator: Russ, G. P., III; Caffee, M.W.; Hudson, G.B. & Storch, N.A.
Object Type: Report
System: The UNT Digital Library
Modified-Yee field solutions in the AMOS wakefield code (open access)

Modified-Yee field solutions in the AMOS wakefield code

A new numerical procedure by which field calculations in AMOS are upgraded to model rotationally symmetric cavity structures in a more accurate fashion is described. The development work is aimed at implementing a modified finite difference update scheme on an irregular grid system. Elements of an irregular grid may be chosen to better fit object boundaries, resulting in increased solution accuracy. Our approach involves the placement of field components on a non-orthogonal body fitting grid and on a dual grid which is orthogonal to the first grid. It is found that this procedure retains several important computational advantages, including the ability to exploit the implied spatial relationships between nodes. Propagating fields on an irregular grid system have been observed and comparisons between finite difference AMOS and Modified-Yee AMOS field calculations are provided.
Date: August 29, 1990
Creator: Shang, C. C. & DeFord, J. F.
Object Type: Article
System: The UNT Digital Library
(Radioactive waste incineration technology development) (open access)

(Radioactive waste incineration technology development)

At the request of the International Atomic Energy Agency (IAEA), technical assistance was provided to the Korea Atomic Energy Research Institute (KAERI) in the field of radwaste incineration and related off-gas treatment operations. The traveler provided the requested technical consolations and, in the process, obtained an understanding of the Republic of Korea's plans for the management of the the wastes from the country's nuclear power plants and research facilities. The government of the Republic of Korea has tasked KAERI to develop the facilities for treating and disposing of the wastes from the country's nuclear facilities in an environmentally responsible manner. As a step in that direction, the Radwaste Treatment Department at KAERI is developing the technology and the plans for the incineration of burnable low-level radwaste, which comprises about 35% of the wastes generated by the nuclear facilities. The incineration program at KAERI appears to be well planned. They have operated a 5-kg/h process design unit incinerator to gather the process data for scaling up the operation to a 30-kg/h demonstration plant. This demonstration plant is presently being built, with startup operations scheduled for January 1991. Data from the demonstration plant are proposed to be used for building a 120-kg/h …
Date: November 29, 1990
Creator: Singh, S. P. N.
Object Type: Report
System: The UNT Digital Library
D0 Silicon Upgrade: Calorimeter Installation Bridge Non-Destructive Test Result (open access)

D0 Silicon Upgrade: Calorimeter Installation Bridge Non-Destructive Test Result

After the central calorimeter was installed on the center beam a cracked weld was found on the bridge. The weld was a partial penetration between the top rail plate and the T-1 steel nose section. The crack is fully across the width of the rail plate and the rail is depressed in a concave shape. That is, the depression is deeper in the center and feathers out to zero at the end of the rail. Upon close inspection it was obvious that there was no penetration of weld metal into the T-1 material. The assumption is that the T-1 was not properly pre-heated before welding. The reason for the concave depression comes from the fact that the rail plate rests on the flanges of the 'S' beams and that during welding the plate pulled off the beams. This weld failure can not propagate to any other welds and therefore, will not start a chain of failures. Clearly the failure of this weld did not hinder the installation of the central calorimeters. This weld failure occurred on both sides of the bridge. This failure did, however, alert us to check the critical weld on the bridge, S-beam webs to T-1 nose …
Date: October 29, 1990
Creator: Stredde, H. J.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: JM-1136 (open access)

Texas Attorney General Opinion: JM-1136

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Applicability of House Bill 1434, Acts 1989, 71st Leg., ch. 1250, at 5046, which relates to purchasing by local units of government, to county attorneys, and related questions (RQ-1881)
Date: January 29, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1153 (open access)

Texas Attorney General Opinion: JM-1153

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Constitutionality of legislation creating Central Texas University (RQ-1861)
Date: March 29, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1249 (open access)

Texas Attorney General Opinion: JM-1249

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Supervisory authority of a district court over a commissioners court with regard to the transfer of funds from a county attorney to a district attorney (RQ-2068)
Date: November 29, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: LO90-82 (open access)

Texas Attorney General Opinion: LO90-82

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Regarding certification requirements for aircraft crash and rescue fire protection personnel employed and by the adjutant general.
Date: October 29, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History