Method and Apparatus for Monitoring the Integrity of a Geomembrane Liner using time Domain Reflectometry (open access)

Method and Apparatus for Monitoring the Integrity of a Geomembrane Liner using time Domain Reflectometry

Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.
Date: November 9, 1998
Creator: Morris, John L.
System: The UNT Digital Library
Statistically Qualified Neuro-Analytic system and Method for Process Monitoring (open access)

Statistically Qualified Neuro-Analytic system and Method for Process Monitoring

An apparatus and method for monitoring a process involves development and application of a statistically qualified neuro-analytic (SQNA) model to accurately and reliably identify process change. The development of the SQNA model is accomplished in two steps: deterministic model adaption and stochastic model adaptation. Deterministic model adaption involves formulating an analytic model of the process representing known process characteristics,augmenting the analytic model with a neural network that captures unknown process characteristics, and training the resulting neuro-analytic model by adjusting the neural network weights according to a unique scaled equation emor minimization technique. Stochastic model adaptation involves qualifying any remaining uncertainty in the trained neuro-analytic model by formulating a likelihood function, given an error propagation equation, for computing the probability that the neuro-analytic model generates measured process output. Preferably, the developed SQNA model is validated using known sequential probability ratio tests and applied to the process as an on-line monitoring system.
Date: November 4, 1998
Creator: Vilim, Richard B.; Garcia, Humberto E. & Chen, Frederick W.
System: The UNT Digital Library
Directly Susceptible, Noncarbon Composite Crucible (open access)

Directly Susceptible, Noncarbon Composite Crucible

A sintered metal ceramic crucible suitable for high temperature induction melting of reactive metals without appreciable carbon or silicon contamination of the melt. The crucible comprises a cast matrix of a thermally conductive ceramic material; a perforated metal sleeve, which serves as a susceptor for induction heating of the crucible, embedded within the ceramic cast matrix; and a thermal-shock-absorber barrier interposed between the metal sleeve and the ceramic cast matrix to allow for differential thermal expansions between the matrix and the metal sleeve and to act as a thermal-shock-absorber which moderates the effects of rapid changes of sleeve temperature on the matrix.
Date: November 25, 1998
Creator: Holcombe, Cressie E., Jr.; Kiggans, James O., Jr.; Morrow, S. Marvin & Rexford, Donald
System: The UNT Digital Library
Method and Apparatus for measuring Gravitational Acceleration Utilizing a high Temperature Superconducting Bearing (open access)

Method and Apparatus for measuring Gravitational Acceleration Utilizing a high Temperature Superconducting Bearing

Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operative temperature at or below 77K, whereby cooling maybe accomplished with liquid nitrogen.
Date: November 6, 1998
Creator: Hull, John R.
System: The UNT Digital Library
Design for Ceramic Membrane Reactor with two Reactant Gases at Different Pressures (open access)

Design for Ceramic Membrane Reactor with two Reactant Gases at Different Pressures

The invention is a ceramic membrane reactor for syngas production having a reaction chamber, an inlet in the reactor for natural gas intake, a plurality of oxygen permeating ceramic slabs inside the reaction chamber with each slab having a plurality of passages paralleling the gas flow for transporting air through the reaction chamber, a manifold affixed to one end of the reaction chamber for intake of air connected to the slabs, a second manifold affixed to the reactor for removing the oxygen depleted air, and an outlet in the reaction chamber for removing syngas.
Date: November 18, 1998
Creator: Balachandran, Uthamalingam & Mieville, Rodney L.
System: The UNT Digital Library