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Searching for Fixed Point Combinators by Using Automated Theorem Proving : a Preliminary Report

Description: In this report, we establish that the use of an automated theorem- proving program to study deep questions from mathematics and logic is indeed an excellent move. Among such problems, we focus mainly on that concerning the construction of fixed point combinators--a problem considered by logicians to be significant and difficult to solve, and often computationally intensive and arduous. To be a fixed point combinator, THETA must satisfy the equation THETAx = x(THETAx) for all combinators x. The specific questions on which we focus most heavily ask, for each chosen set of combinators, whether a fixed point combinator can be constructed from the members of that set. For answering questions of this type, we present a new, sound, and efficient method, called the kernel method, which can be applied quite easily by hand and very easily by an automated theorem-proving program. For the application of the kernel method by a theorem-proving program, we illustrate the vital role that is played by both paramodulation and demodulation--two of the powerful features frequently offered by an automated theorem-proving program for treating equality as if it is ''understood.'' We also state a conjecture that, if proved, establishes the completeness of the kernel method. From what we can ascertain, this method--which relies on the introduced concepts of kernel and superkernel--offers the first systematic approach for searching for fixed point combinators. We successfully apply the new kernel method to various sets of combinators and, for the set consisting of the combinators B and W, construct an infinite set of fixed point combinators such that no two of the combinators are equal even in the presence of extensionality--a law that asserts that two combinators are equal if they behave the same. 18 refs.
Date: September 1988
Creator: Wos, Larry
Partner: UNT Libraries Government Documents Department
open access

Avoiding Leakage Flow-Induced Vibration by a Tube-in-Tube Slip Joint

Description: Parameters and operating conditions (a stability map) were determined for which a specific slip-joint design did not cause self-excited lateral vibration of the two cantilevered, telescoping tubes forming the joint. The joint design featured a localized annular constriction. Flowrate, modal damping, tube engagement length, and eccentric positioning were among the parameters tested. Interestingly, all self-excited vibrations could be avoided by following a simple design rule: place constrictions only at the downstream end of the annular region between the tubes. Also, overall modal damping decreased with increased flowrate, at least initially, for upstream constrictions while the damping increased for downstream constrictions.
Date: October 1984
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
open access

Second Thoughts on the Mathematical Software Effort : a Perspective

Description: The mathematical software effort bridges the gap between the discovery of numerical algorithms and the consumption of numerical software. The spectrum of activities is surprisingly wide, including tasks often associated with numerical analysis, program design and testing, programming practices, language standards, documentation standards, software organization, distribution methods, and even the specification of arithmetic engines. This paper highlights the most important accomplishments in the field over the last twenty years. It also examines current problems and future challenges posed by the rapid advance of technology.
Date: October 1984
Creator: Cody, William James
Partner: UNT Libraries Government Documents Department
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Flow-Induced Vibration of the SSME Lox Posts : Additional Issues

Description: A mathematical model is presented for flow-induced vibration of the Space Shuttle Main Engine (SSME) liquid oxygen (LOX) posts. The definition of the critical flow velocity is addressed, and detuning of the vibrations of the LOX posts is discussed. Nonuniform flow distributions in the axial and transverse directions are examined briefly, followed by upstream turbulence. The dependence of response upon post location is addressed briefly. Scruton's number, a mass-damping parameter, is defined and its value for the SSME LOX posts is given. Also discussed are the interaction of turbulent buffeting and fluidelastic instability, post arrangement, and swirlers around the posts. The differences are discussed between the quasi-static, the analytical, and the general analytical mathematical models.
Date: December 1984
Creator: Chen, Shoei-Sheng
Partner: UNT Libraries Government Documents Department
open access

Chemical Technology Division Annual Technical Report for 1984

Description: Report on studies of advanced batteries, aqueous batteries, advanced fuel cells, coal utilization, methodologies for recovery of energy from municipal waste, solid and liquid desiccants, nuclear technology related to waste management, and physical chemistry of selected materials in environments simulating those of fission, fusion, and other energy systems.
Date: February 1985
Creator: Argonne National Laboratory. Chemical Technology Division.
Partner: UNT Libraries Government Documents Department
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Radioactive Liquid Waste Treatment Facility

Description: The Radioactive Liquid Waste Treatment Facility (RLWTF) at Argonne National Laboratory-West (ANL-W) in Idaho provides improved treatment for low-level aqueous waste compared to conventional systems. A unique, patented evaporated system is used in the RLWTF. SHADE (shielded hot air drum evaporator, US Patent No. 4,305,780) is a low-cost disposable unit constructed from standard components and is self-shielded. The results of testing and recent operations indicate that evaporation rates of 2 to 6 gph (8 to 23 L/h) can be achieved with a single unit housed in a standard 30-gal (114-L) drum container. The operating experience has confirmed the design evaporation rate of 60,000 gal (227,000 L) per year, using six SHADE's.
Date: July 1984
Creator: Black, Roger L.
Partner: UNT Libraries Government Documents Department
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Accuracy of the Finite Analytic Method for Scalar Transport Calculations

Description: The accuracy of the finite analytic method of discretizing fluid flow equations is assessed through calculations of multidimensional scalar transport. The transport of a scalar function in a uniform velocity flow field inclined with the finite-difference grid lines is calculated for a range of grid Peclet numbers and flow skewness. The finite analytic method is observed to be superior to the approach of constructing finite-difference analogs from locally one-dimensional resolution of the flow vector. However, the finite analytic method also produces appreciable errors locally in regions of steep variations, under conditions of large grid Peclet numbers, and skewness of the streamlines.
Date: September 1984
Creator: Vanka, S. P.
Partner: UNT Libraries Government Documents Department
open access

An Alternative Library Under 4. 2 BSD UNIX on a VAX 11/780

Description: This paper describes an alternative library of elementary functions prepared for use with the standard Fortran compiler under 4.2 BSD UNIX on a VAX 11/780. The library, written in C and based on the book ''Software Manual for the Elementary Functions'' by Cody and Waite, offers improved accuracy over the standard system library, as well as additional capabilities. Listings and output from the ELEFUNT suite of test programs are included in the appendix.
Date: February 1986
Creator: Cody, William James
Partner: UNT Libraries Government Documents Department
open access

Leakage Flow-Induced Vibrations for Variations of a Tube-in-Tube Slip Joint

Description: Variations in the design of a specific slip joint separating two cantilevered, telescoping tubes conveying water were studied to determine their effect upon the leakage flow-induced vibration self-excitation mechanism known to exist for the original slip joint geometry. The important parameters controlling the self-excitation mechanism were identified, which, along with previous results, allowed the determination of a comprehensive set of design rules to avoid unstable vibrations. This was possible even though a new self-excitation mechanism was found when the engagement of the two tubes was small.
Date: January 1986
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
open access

Leakage Flow-Induced Vibration of an Unconstricted Tube-in-Tube Slip Joint

Description: The conditions are given for which the more flexible of two cantilevered, telescoping tubes conveying fluid can be self-excited by flow leaking from an un-constricted slip joint. Also, a physical explanation of the excitation mechanism is discussed, and a design rule to avoid the mechanism is presented. In addition, the results for the un-constricted slip joint are shown to be similar to those for slip joints having annulus constrictions at very short engagement lengths.
Date: March 1986
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
open access

SARA : a Small Automated Reasoning Assistant

Description: SARA is a rewriting system where the rewrite rules are heads of Horn clauses. Thus an expression is rewritten only when the conjunction of goals in the body of the Horn clause is true. The system has a model of rewriting as construction of a linked graph with expressions annotating nodes and rewritings annotating arcs. Cycles in the graph are recognized and may be specially processed by the user. The default is to use an alternative rewriting rule to break out of this cycle.
Date: 1986
Creator: Gabriel, John R.
Partner: UNT Libraries Government Documents Department
open access

Flow-Induced Vibration of Circular Cylindrical Structures

Description: This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders.
Date: June 1985
Creator: Chen, Shoei-Sheng
Partner: UNT Libraries Government Documents Department
open access

General Theory for Dynamic Instability of the SSME LOX Posts

Description: A general theory of fluid-elastic instability for a tube array in crossflow is presented for application to the space shuttle main engine liquid oxygen (SSME LOX) posts. Various techniques to obtain the motion-dependent fluid-force coefficients are discussed and the general instability characteristics are summarized. The theory is also used to evaluate the results of other mathematical models for crossflow-induced instability.
Date: September 1985
Creator: Chen, Shoei-Sheng
Partner: UNT Libraries Government Documents Department
open access

Leakage Flow-Induced Vibration of an Eccentric Tube-in-Tube Slip Joint

Description: Eccentricity of a specific slip-joint design separating two cantilevered, telescoping tubes did not create any self-excited lateral vibrations that had not been observed previously for a concentric slip joint. In fact, the eccentricity made instabilities less likely to occur, but only marginally. Most important, design rules previously established to avoid instabilities for the concentric slip joint remain valid for the eccentric slip joint.
Date: August 1985
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
open access

The TRIO Experiment

Description: The TRIO experiment is a test of in-situ tritium recovery and heat transfer performance of a miniaturized solid breeder blanket assembly. The assembly (capsule) was monitored for temperature and neutron flux profiles during irradiation and a sweep gas flowed through the capsule to an analytical train wherein the amounts of tritium in its various chemical forms were determined. The capsule was designed to operate at different temperatures and sweep gas conditions. At the end of the experiment the amount of tritium retained in the solid was at a concentration of less than 0.1 wppM. More than 99.9% of tritium generated during the experiment was successfully recovered. The results of the experiment showed that the tritium inventories at the beginning and at the end of the experiment follow a relationship which appears to be characteristic of intragranular diffusion.
Date: September 1984
Creator: Clemmer, Robert G.
Partner: UNT Libraries Government Documents Department
open access

A Design Philosophy for Reliable Systems, Including Control

Description: This report develops a framework for a universe of discourse usable by such non-human experts. It is based on the idea that a design has many features of a contract and may be described as a contract between humans and a machine, defining what each must do to attain a goal. Several points are discussed: the use of techniques in analytical redundancy and their place as analogues in administrative control for conventional techniques in physical control; the use of redundant computer systems to protect against hardware faults; the necessity to prove properties of software used in redundant hardware, because software faults are common modes across redundant hardware; and some issues in choosing a programming language for provable control software. Because proof of correctness is costly, it should be used only where necessary. This report concludes that the degree of reliability needed by the plant model used in analytic redundancy protection need not be nearly as reliable as the mechanism to detect discrepancy between plant and model.
Date: April 1984
Creator: Gabriel, John R.
Partner: UNT Libraries Government Documents Department
open access

Dynamic Characteristics of Heat Exchanger Tubes Vibrating in a Tube Support Plate Inactive Mode

Description: Tubes in shell-and-tube heat exchangers, including nuclear plant steam generators, derive their support from longitudinally positioned tube support plates (TSPs). Typically there is a clearance between the tube and TSP hole. Depending on design and fabrication tolerances, the tube may or may not contract all of the TSPs. Noncontact results in an inactive TSP which can lead to detrimental flow induced tube vibrations under certain conditions dependent on the resulting tube-TSP interaction dynamics and the fluid excitation forces. The purpose of this study is to investigate the tube-TSP interaction dynamics. Results of an experimental study of damping and natural frequency as functions of tube-TSP diametral clearance and TSP thickness are reported. Calculated values of damping ratio and frequency of a tube vibrating within an inactive TSP are also presented together with a comparison of calculated and experimental quantities.
Date: August 1984
Creator: Jendrzejczyk, J. A.
Partner: UNT Libraries Government Documents Department
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Transuranic Decontamination of Nitric Acid Solutions by the Truex Solvent Extraction Process: Preliminary Development Studies

Description: This report summarizes the work that has been performed to date at Argonne National Laboratory on the development of the TRUEX process, a solvent extraction process employing a bifunctional organophosphorous reagent in a PUREX process solverc (tributyl phosphate-normal paraffinic hydrocarbons). The purpose of this extraction process is to separate and concentrate transuranic (TRU) elements from nuclear waste.
Date: July 1984
Creator: Vandegrift, G. F.
Partner: UNT Libraries Government Documents Department
open access

Annual Technical Report

Description: Highlights of the Chemical Technology (CMT) Division's activities during 1989 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including high-performance batteries (mainly lithium/iron sulfide and sodium/metal chloride), aqueous batteries (lead-acid and nickel/iron), and advanced fuel cells with molten carbonate and solid oxide electrolytes; (2) coal utilization, including the heat and seed recovery technology for coal-fired magnetohydrodynamics plants and the technology for fluidized-bed combustion; (3) method, for recovery of energy from municipal waste and techniques for treatment of hazardous organic waste; (4) nuclear technology related to a process for separating and recovering transuranic elements from nuclear waste and for producing 99Mo from low-enriched uranium targets, the recovery processes for discharged fuel and the uranium blanket in a sodium-cooled fast reactor (the Integral Fast Reactor), and waste management; and (5) physical chemistry of selected materials in environments simulating those of fission and fusion energy systems.
Date: March 1990
Creator: Argonne National Laboratory. Chemical Technology Division.
Partner: UNT Libraries Government Documents Department
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Annual Technical Report

Description: Highlights of the Chemical Technology Division's activities during 1990, including electrochemical technology and advanced batteries and fuel cells, technology for coal-fired magnetohydrodynamics and fluidized-bed combustion, methods for recovery of energy from municipal waste, and techniques for treatment of hazardous organic waste, the reaction of nuclear waste glass and spent fuel under conditions expected for a high-level waste repository.
Date: May 1991
Creator: Argonne National Laboratory. Chemical Technology Division.
Partner: UNT Libraries Government Documents Department
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Some Issues Concerning Fluidelastic Instability of a Group of Circular Cylinders in Crossflow

Description: Since the early 1970s, extensive studies of fluid-elastic instability of circular cylinders in crossflow have been reported. A significant understanding of the phenomena involved now exists. However, some confusion, misunderstanding, and misinterpretation still remain. The objective of this report is to discuss, on the basis of the current state of the art, a series of the most asked questions. Emphasis is placed on the determination of the critical flow velocity, non-dimensional parameters, stability criteria, and instability mechanisms.
Date: April 1988
Creator: Chen, Shoei-Sheng
Partner: UNT Libraries Government Documents Department
open access

Flow Enhancement of Annulus Damping

Description: Significant increases in flow damping were observed for a tube passing through a plate when a sharp-edge raised-diameter constriction was added to the hole in a plate subject to a constant pressure drop. A correlation of the data in the form of a concentrated viscous damper (dashpot) is given which will be useful in structural dynamic analysis.
Date: April 1986
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
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