Computation at the edge of chaos: Phase transition and emergent computation (open access)

Computation at the edge of chaos: Phase transition and emergent computation

In order for computation to emerge spontaneously and become an important factor in the dynamics of a system, the material substrate must support the primitive functions required for computation: the transmission, storage, and modification of information. Under what conditions might we expect physical systems to support such computational primitives This paper presents research on Cellular Automata which suggests that the optimal conditions for the support of information transmission, storage, and modification, are achieved in the vicinity of a phase transition. We observe surprising similarities between the behaviors of computations and systems near phase-transitions, finding analogs of computational complexity classes and the Halting problem within the phenomenology of phase-transitions. We conclude that there is a fundamental connection between computation and phase-transitions, and discuss some of the implications for our understanding of nature if such a connection is borne out. 31 refs., 16 figs.
Date: January 25, 1990
Creator: Langton, C.
Object Type: Article
System: The UNT Digital Library
The TITAN reversed-field-pinch fusion reactor study (open access)

The TITAN reversed-field-pinch fusion reactor study

This report discusses research on the titan-1 fusion power core. The major topics covered are: titan-1 fusion-power-core engineering; titan-1 divertor engineering; titan-1 tritium systems; titan-1 safety design and radioactive-waste disposal; and titan-1 maintenance procedures.
Date: January 1, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Jewish Herald-Voice (Houston, Tex.), Vol. 81, No. 42, Ed. 1 Thursday, January 18, 1990 (open access)

Jewish Herald-Voice (Houston, Tex.), Vol. 81, No. 42, Ed. 1 Thursday, January 18, 1990

Weekly Jewish newspaper from Houston, Texas that includes local, state, and national news along with advertising.
Date: January 18, 1990
Creator: Samuels, Jeanne F.
Object Type: Newspaper
System: The Portal to Texas History
Altus Times (Altus, Okla.), Vol. 68, No. 12, Ed. 1 Sunday, January 14, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 12, Ed. 1 Sunday, January 14, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 14, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Ultrastructural changes in the lung following exposure to perfluoroisobutylene (PFIB) and potentiation of PFIB-induced lung injury by post-exposure exercise (open access)

Ultrastructural changes in the lung following exposure to perfluoroisobutylene (PFIB) and potentiation of PFIB-induced lung injury by post-exposure exercise

The authors investigated the kinetics of development of the injurious effects of perfluoroisobutylene (PFIB) in the lower respiratory tract of the rat as a function of inhaled mass concentration. We additionally examined if exercise performed after exposure to PFIB can potentiate the severity of expression of PFIB-induced lung injury, while also assessing how PFIB exposure may result in reductions in work performance capacity. The severity of PFIB-induced lung injury was found to be directly proportional to inhaled PFIB mass concentration whereas the post-exposure kinetics of development of the injurious response was inversely proportional to the mass concentration of PFIB, with post-exposure latency periods prior to the onset of detectable injury increasing with decreasing inhaled mass concentration. Exercise was found to potentiate PFIB-induced lung injury only after pulmonary edema was demonstrably present using lung gravimetric and light histopathologic criteria, even though ultrastructural observations indicated significant cellular changes occur during the latency period. Our collective findings suggest that pre-existing permeability changes in the lung are a necessary prerequisite for post-exposure exercise to exert a potentiating effect. Reductions in work performance capacity occurred only after the latency period, and such reductions proportionately scaled with the severity of pulmonary edema. 9 refs., 5 figs.
Date: January 1, 1990
Creator: Lehnert, B. E. & Stavert, D. M.
Object Type: Article
System: The UNT Digital Library
Monitoring challenges and innovative ideas (open access)

Monitoring challenges and innovative ideas

Monitoring programs are difficult to design even when they focus on specific problems. Ecosystems are complex, and it is often impossible to predetermine what aspects of system structure or dynamics will respond to a specific insult. It is equally difficult to interpret whether a response is a stabilizing compensatory mechanism or a real loss of capacity to maintain the ecosystem. The problems are compounded in a broad monitoring program designed to assess ecosystem health'' at regional and continental scales. It is challenging in the extreme to monitor ecosystem response, at any scale, to past insults as well as an unknown future array of impacts. The present paper will examine some of the fundamental issues and challenges raised by large-scale monitoring efforts. The challenges will serve as a framework and as an excuse to discuss several important topics in more detail. Following the discussion of challenges, we suggest some basic innovations that could be important across a range of monitoring programs. The innovations include integrative measures, innovative methodology, and creative interpretation. 59 refs., 1 tab.
Date: January 1, 1990
Creator: O'Neill, R. V.; Hunsaker, C. T. & Levine, D. A.
Object Type: Article
System: The UNT Digital Library
Sanger Courier (Sanger, Tex.), Vol. 90, No. 50, Ed. 1 Thursday, January 11, 1990 (open access)

Sanger Courier (Sanger, Tex.), Vol. 90, No. 50, Ed. 1 Thursday, January 11, 1990

Weekly newspaper from Sanger, Texas that includes local, state, and national news along with extensive advertising.
Date: January 11, 1990
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Daily (Norman, Okla.), Vol. 74, No. 87, Ed. 1 Friday, January 12, 1990 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 74, No. 87, Ed. 1 Friday, January 12, 1990

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: January 12, 1990
Creator: Schafer, Shaun
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Tracings, Volume 08, Number 02, Winter 1990 (open access)

The Tracings, Volume 08, Number 02, Winter 1990

The genealogical information may include generation charts, family histories, and lists of records (births, deaths, church records, etc.). Name index begins after page 29.
Date: January 1990
Creator: Anderson County Genealogical Society
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
The Tulia Herald (Tulia, Tex.), Vol. 82, No. 1, Ed. 1 Thursday, January 4, 1990 (open access)

The Tulia Herald (Tulia, Tex.), Vol. 82, No. 1, Ed. 1 Thursday, January 4, 1990

Weekly newspaper from Tulia, Texas that includes local, state and national news along with extensive advertising.
Date: January 4, 1990
Creator: Tooley, Wendell
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Eagle (Tulsa, Okla.), Vol. 69, No. 2, Ed. 1 Thursday, January 25, 1990 (open access)

The Oklahoma Eagle (Tulsa, Okla.), Vol. 69, No. 2, Ed. 1 Thursday, January 25, 1990

Weekly newspaper from Tulsa, Oklahoma that includes local, state, and national news along with advertising.
Date: January 25, 1990
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Tulia Herald (Tulia, Tex.), Vol. 82, No. 4, Ed. 1 Thursday, January 25, 1990 (open access)

The Tulia Herald (Tulia, Tex.), Vol. 82, No. 4, Ed. 1 Thursday, January 25, 1990

Weekly newspaper from Tulia, Texas that includes local, state and national news along with extensive advertising.
Date: January 25, 1990
Creator: Tooley, Wendell
Object Type: Newspaper
System: The Portal to Texas History
The Albany News (Albany, Tex.), Vol. 114, No. 33, Ed. 1 Thursday, January 25, 1990 (open access)

The Albany News (Albany, Tex.), Vol. 114, No. 33, Ed. 1 Thursday, January 25, 1990

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: January 25, 1990
Creator: Lucas, Donnie A.
Object Type: Newspaper
System: The Portal to Texas History
Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 37, Ed. 1 Monday, January 15, 1990 (open access)

Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 37, Ed. 1 Monday, January 15, 1990

Weekly newspaper from Jacksboro, Texas that includes local, state, and national news along with extensive advertising.
Date: January 15, 1990
Creator: McGee, Leigh
Object Type: Newspaper
System: The Portal to Texas History
The Albany News (Albany, Tex.), Vol. 114, No. 31, Ed. 1 Thursday, January 11, 1990 (open access)

The Albany News (Albany, Tex.), Vol. 114, No. 31, Ed. 1 Thursday, January 11, 1990

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: January 11, 1990
Creator: Lucas, Donnie A.
Object Type: Newspaper
System: The Portal to Texas History
Polk County Enterprise (Livingston, Tex.), Vol. 108, No. 1, Ed. 1 Thursday, January 4, 1990 (open access)

Polk County Enterprise (Livingston, Tex.), Vol. 108, No. 1, Ed. 1 Thursday, January 4, 1990

Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date: January 4, 1990
Creator: White, Barbara
Object Type: Newspaper
System: The Portal to Texas History
The Tulia Herald (Tulia, Tex.), Vol. 82, No. 2, Ed. 1 Thursday, January 11, 1990 (open access)

The Tulia Herald (Tulia, Tex.), Vol. 82, No. 2, Ed. 1 Thursday, January 11, 1990

Weekly newspaper from Tulia, Texas that includes local, state and national news along with extensive advertising.
Date: January 11, 1990
Creator: Tooley, Wendell
Object Type: Newspaper
System: The Portal to Texas History
Chickasha Daily Express (Chickasha, Okla.), Vol. 98, No. 261, Ed. 1 Sunday, January 14, 1990 (open access)

Chickasha Daily Express (Chickasha, Okla.), Vol. 98, No. 261, Ed. 1 Sunday, January 14, 1990

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: January 14, 1990
Creator: Drew, Charles C.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 39, Ed. 1 Monday, January 29, 1990 (open access)

Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 39, Ed. 1 Monday, January 29, 1990

Weekly newspaper from Jacksboro, Texas that includes local, state, and national news along with extensive advertising.
Date: January 29, 1990
Creator: McGee, Leigh
Object Type: Newspaper
System: The Portal to Texas History
Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 35, Ed. 1 Monday, January 1, 1990 (open access)

Jacksboro Gazette-News (Jacksboro, Tex.), Vol. 109, No. 35, Ed. 1 Monday, January 1, 1990

Weekly newspaper from Jacksboro, Texas that includes local, state, and national news along with extensive advertising.
Date: January 1, 1990
Creator: McGee, Leigh
Object Type: Newspaper
System: The Portal to Texas History
The Talco Times (Talco, Tex.), Vol. 53, No. 52, Ed. 1 Thursday, January 25, 1990 (open access)

The Talco Times (Talco, Tex.), Vol. 53, No. 52, Ed. 1 Thursday, January 25, 1990

Weekly newspaper from Talco, Texas that includes local, state, and national news along with advertising.
Date: January 25, 1990
Creator: Nichols, Thomas & Nichols, Nanalee
Object Type: Newspaper
System: The Portal to Texas History
The Albany News (Albany, Tex.), Vol. 114, No. 32, Ed. 1 Thursday, January 18, 1990 (open access)

The Albany News (Albany, Tex.), Vol. 114, No. 32, Ed. 1 Thursday, January 18, 1990

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: January 18, 1990
Creator: Lucas, Donnie A.
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Daily (Norman, Okla.), Vol. 74, No. 97, Ed. 1 Friday, January 26, 1990 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 74, No. 97, Ed. 1 Friday, January 26, 1990

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: January 26, 1990
Creator: Schafer, Shaun
Object Type: Newspaper
System: The Gateway to Oklahoma History
Characteristics and potential applications of an ORNL microwave ECR multicusp plasma ion source (open access)

Characteristics and potential applications of an ORNL microwave ECR multicusp plasma ion source

A new microwave electron cyclotron resonance (ECR) multicusp plasma ion source that has two ECR plasma production regions and uses multicusp plasma confinement has been developed at Oak Ridge National Laboratory. This source has been operated to produce uniform and dense plasma over large areas of 300 to 400 cm{sup 2} and could be scaled up to produce uniform plasma over 700 cm{sup 2} or larger. The plasma source has been operated with continuous argon gas feed and pulsed microwave power. The working gases used were argon, helium, hydrogen, and oxygen. The discharge initiation phenomena and plasma properties have been investigated and studied as functions of the discharge parameters. The discharge characteristics and a hypothetical discharge mechanism for this plasma source are described and discussed. Potential applications, including plasma and ion-beam sources for manufacturing advanced microelectronics, for space electric propulsion, and for fusion research, are discussed. 10 refs., 10 figs.
Date: January 1, 1990
Creator: Tsai, C.C.
Object Type: Article
System: The UNT Digital Library