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1992

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Articles 1 - 30 of 1611

Full-Text Articles in Physical Sciences and Mathematics

A Comparison Of Integration Architectures, Amar Mahidadia Dec 1992

A Comparison Of Integration Architectures, Amar Mahidadia

Theses

This paper presents GenSIF, a Generic Systems Integration Framework. GenSIF features a pre-planned development process on a domain-wide basis and facilitates system integration and project coordination for very large, complex and distributed systems. Domain analysis, integration architecture design and infrastructure design are identified as the three main components of GenSIF. In the next step we map Beilcore's OSCA interoperability architecture, ANSA, IBM's SAA and Bull's DCM into GenSIF. Using the GenSIF concepts we compare each of these architectures.

GenSIF serves as a general framework to evaluate and position specific architecture. The OSCA architecture is used to discuss ...


A Thermal Desorption Modulator For Continuous Monitoring Of Volatile Organic Compounds, Yun Chen Dec 1992

A Thermal Desorption Modulator For Continuous Monitoring Of Volatile Organic Compounds, Yun Chen

Theses

A thermal desorption modulator is made from a short segment of thin tubing containing an adsorbent or a chromatographic stationary phase. A carrier gas containing the analyte is introduced into the analytical column through the modulator which acts as a sample trap. Rapid electrical heating of the modulator releases a "concentration pulse" of the analyte and this serves as an injection similar to that from an injection valve. The modulator also acts as a sample preconcentrator and can be used to make repetitive injections every few seconds. In this research, the mechanism of thermal desorption modulator was studied and was ...


A Petri Net Toolkit For Parallel Program Debugging, Potla Kishore Reddy Dec 1992

A Petri Net Toolkit For Parallel Program Debugging, Potla Kishore Reddy

Theses

An effective debugger must support the language and operating system resource abstractions that are available to the programmer. Earlier debuggers worked at the machine architecture level: they dealt with machine instructions and registers. Current debuggers, designed for single process debugging, permit access to program variables and breakpoints and single-stepping at the level of high-level language statements. Eventhough the current debuggers, are already implemented to be a powerful tool, they still cannot do a job of parallel debugger.

In this thesis, a computer simulation system has been established by Petri Nets execution providing a convenient and friendly interface as it allows ...


Application Of Organophilic Clay, Koshy Koshy Dec 1992

Application Of Organophilic Clay, Koshy Koshy

Theses

The overall goal of this project is to asses the feasibility of using clay to filter water contaminated with organic contaminants. The clays that were used were provided by the Union Carbide Corporation and the Industrial Mineral Ventures (IMV), a division of Floridin company. The organic contaminants that this project concentrated on were, naphthalene, 1,4-dioxane, and phenol. The feasibility studies were done by batch isotherm studies. The protocol for the batch studies were the same as the ones used previously for granular activated carbon. This project looked at a total of six Union Carbide clays and five IMV Floridin ...


An Enhancement And Improvement Of A Prototype Distributed System Based On Elements Of An Integration Architecture, Kunal R. Shah Dec 1992

An Enhancement And Improvement Of A Prototype Distributed System Based On Elements Of An Integration Architecture, Kunal R. Shah

Theses

The concepts and results presented in this thesis are related to Integrated System Development. It provides introduction to Generic System Integration Framework (GenSIF). And hence its three principal components, Domain Analysis, Integration Architectures and Enabling Technology. It addresses certain issues of distributed processing relating to systems integration.

The primary objective of this thesis is to develop/improve a prototype by applying concepts and ideas presented in GenSIF, with an example channel based building block integration architecture as an example. This prototype was developed with the objective of studying the effect of system intregration framework in mind while working on an ...


Giant Suppression Of Flux-Flow Resistivity In Heavy-Ion Irradiated Tl2Ba2Ca2Cu3O10 Films: Influence Of Linear Defects On Vortex Transport, R.C. Budhani, M. Suenaga, Sy_Hwang Liou Dec 1992

Giant Suppression Of Flux-Flow Resistivity In Heavy-Ion Irradiated Tl2Ba2Ca2Cu3O10 Films: Influence Of Linear Defects On Vortex Transport, R.C. Budhani, M. Suenaga, Sy_Hwang Liou

Si-Hwang Liou Publications

A large shift of the onset of flux-flow resistivity and the irreversibility line Hirr (T) to higher temperatures is observed in Tl2Ba2Ca2Cu3O10 films containing linear defects created by Ag+21 ion irradiation. The Hirr(T), which has a characteristic ssL shape in highly anisotropic Tl and Bi based cuprates, becomes more like that of YBa2Cu3O7 in the presence of these defects. The Jc at 77 K also shows a large increase as a result of flux localization at the defects. The transport data ...


Performance Of Iterative Methods For Distributed Memory Processors, Dan C. Marintescu, John R. Rice, E. Vavallis Dec 1992

Performance Of Iterative Methods For Distributed Memory Processors, Dan C. Marintescu, John R. Rice, E. Vavallis

Department of Computer Science Technical Reports

No abstract provided.


The Elastic Moduli Of Simple Two-Dimensional Isotropic Composites: Computer Simulation And Effective Medium Theory, K. A. Snyder, E. J. Garboczi, Anthony Roy Day Dec 1992

The Elastic Moduli Of Simple Two-Dimensional Isotropic Composites: Computer Simulation And Effective Medium Theory, K. A. Snyder, E. J. Garboczi, Anthony Roy Day

Anthony Roy Day

An algorithm, combining digital-image with spring network techniques, has been developed that enables computation of the elastic moduli of random two-dimensional multiphase composites. This algorithm is used to study the case of isotropic, randomly centered, overlapping circular inclusions in an isotropic elastic matrix. The results of the algorithm for the few-inclusion limit, as well as the case where both phases have the same shear moduli, agree well with the exact results for these two problems. The case where the two phases have the same Poisson’s ratio, but different Young’s moduli, is also studied, and it is shown that ...


The Weakest Bond: Experimental Observation Of Helium Dimer, Fei Luo, George C. Mcbane, Geunsik Kim, Clayton F. Giese, W. Ronald Gentry Dec 1992

The Weakest Bond: Experimental Observation Of Helium Dimer, Fei Luo, George C. Mcbane, Geunsik Kim, Clayton F. Giese, W. Ronald Gentry

Peer Reviewed Articles

Helium dimer ion was observed after electron impact ionization of a supersonic expansion of helium with translational temperature near 1 mK. The dependence of the ion signal on source pressure, distance from the source, and electron kinetic energy was measured. The signal was determined to arise from ionization of neutral helium dimer.


The Morphology Of Lava Flows In Planetary Environments: Predictions From Analog Experiments, Ross W. Griffiths, Jonathan H. Fink Dec 1992

The Morphology Of Lava Flows In Planetary Environments: Predictions From Analog Experiments, Ross W. Griffiths, Jonathan H. Fink

Geology Faculty Publications and Presentations

The rates of surface cooling and lateral spreading are evaluated for lava flows on the surface of Earth, Venus, Mars, the Moon, and 10. Differences between the flow morphologies expected in these environments are then predicted under the assumption that the results of recent laboratory simulations oflavas using wax extruded beneath cold water (Fink and Griffiths, 1990) can be carried over. These experiments involved the spreading of viscous liquid under gravity in the presence of a solidifying surface crust and revealed a set of four distinct surface morphologies. Transitions from one morphology to the next occurred in a well-defined sequence ...


Solidification And Morphology Of Submarine Lavas: A Dependence On Extrusion Rate, Ross W. Griffiths, Jonathan H. Fink Dec 1992

Solidification And Morphology Of Submarine Lavas: A Dependence On Extrusion Rate, Ross W. Griffiths, Jonathan H. Fink

Geology Faculty Publications and Presentations

The results of recent laboratory experiments with wax extruded beneath relatively cold water may be extrapolated to predict the surface morphology of submarine lavas as a function of the extrusion rate and melt vIscosity. The experiments with solidifying wax indicated that the surface morphology was controlled by a single parameter, the ratio of the time taken for the surface to solidify, and a time scale for lateral flow. For submarine basalts a solution of the cooling problem (which is dominated by conduction in the lava but convective heat transfer in the water) and estimates of lava viscosities place this parameter ...


Free Radical-Catalyzed Synthesis Of Benzoprostacyclins, Richard C. Larock, Nam H. Lee Dec 1992

Free Radical-Catalyzed Synthesis Of Benzoprostacyclins, Richard C. Larock, Nam H. Lee

Iowa State University Patents

A method is provided for preparing benzoprostacyclins by the free-radical-catalyzed tandem alkene insertion into a 1,4-bisoxy-substituted cyclopent-2-ene intermediate.


Translational Correlations In The Vortex Array At The Surface Of A Type-Ii Superconductor, M. Cristina Marchetti, David R. Nelson Dec 1992

Translational Correlations In The Vortex Array At The Surface Of A Type-Ii Superconductor, M. Cristina Marchetti, David R. Nelson

Physics

We discuss the statistical mechanics of magnetic flux lines in a finite-thickness slab of type-II superconductor. The long wavelength properties of a flux-line liquid in a slab geometry are described by a hydrodynamic free energy that incorporates the boundary conditions on the flux lines at the sample's surface as a surface contribution to the free energy. Bulk and surface weak disorder are modeled via Gaussian impurity potentials. This free energy is used to evaluate the two-dimensional structure factor of the flux-line tips at the sample surface. We find that surface interaction always dominates in determining the decay of translational ...


Digital Soil Maps For Iowa, Gerald A. Miller, Robert C. Mortensen Dec 1992

Digital Soil Maps For Iowa, Gerald A. Miller, Robert C. Mortensen

Proceedings of the Integrated Crop Management Conference

The Iowa Cooperative Soil Survey (ICSS) initiated a program in 1987 to transfer printed soil maps in each county soil survey report to an electronic database. The purpose of this cooperative project is to provide a computerized database of the county soil maps to support federal, state, local and private sector decision-making concerning use and management of Iowa's soil resources.


What's With The Weather?, S. Elwynn Taylor Dec 1992

What's With The Weather?, S. Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Most crops are well adapted to the prevailing climate. Nevertheless, weather remains the most significant factor in successful crop production. Weather-wise management of production and marketing can greatly reduce the risk of crop loss and of fmancial failure in crop production. The cyclic nature of midwest weather, the relationship of potential yield to soil moisture, and the effects of temperature on the development of crops and crop pests should be understood by the farmer and by the farm service representative. Com yield in Iowa and Illinois improved slowly during the first half of the 20th century. There was considerable yield ...


Spray-Wind-Inversion, S. Elwynn Taylor Dec 1992

Spray-Wind-Inversion, S. Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Wind, clouds, humidity, stability--there are numerous properties of the atmosphere that influence effective application of agricultural chemicals. Whenever a material is dispersed in the atmosphere, some of it will, inevitably not reach the intended target. The responsibility of the applicator is to minimize drift that is to apply at a time and in a manner that will not result in the movement of significant concentrations of material away from the target zone: Drift can result from wind carry, from high concentrations of fine mist suspended in the air, and from vapor drift. Drift may be hazardous to nontarget crops, to ...


Beneficial Microorganisms In Low-Input Agriculture, Thomas E. Loynachan Dec 1992

Beneficial Microorganisms In Low-Input Agriculture, Thomas E. Loynachan

Proceedings of the Integrated Crop Management Conference

The overall involvement of microorganisms in crop production still remains much of a mystery. Because of their distribution and size, most studies have been done in the laboratory and the implications of these studies referred back to the field. With this approach, unfortunately, much remains unknown, not only about the growth of individual organisms, but certainly the interactions of organisms in nature. Several "nontraditional" soil amendments have been marketed over the years that capitalize on our lack of understanding of soil microbial processes. Terms such as soil activators, soil enhancers, and enzyme stimulators have been used, claiming to improve soil ...


Reducing Pesticide Movement To Surface Water, Margaret A. Smith Dec 1992

Reducing Pesticide Movement To Surface Water, Margaret A. Smith

Proceedings of the Integrated Crop Management Conference

Pesticides (largely herbicides) can be detected in Iowa surface waters---but when found, are usually at very low concentrations (ppb). Concentrations and total herbicide losses to surface waters are often highest in the spring after chemical applications and heavy rains. Many management practices can be used to help minimize pesticides in Iowa waters. Farmers, dealers, and pesticide applicators may address the issue by focusing only on herbicide management. Other crop management tools are as important and should be considered before changing pest control strategies. The following checklist may be helpful for farm advisors reviewing options for reducing pesticides in surface waters.


Agricultural Contribution Of Nitrate-N To The Des Moines River: 1945 Vs. 1980, Dennis R. Keeney, Thomas H. Deluca Dec 1992

Agricultural Contribution Of Nitrate-N To The Des Moines River: 1945 Vs. 1980, Dennis R. Keeney, Thomas H. Deluca

Proceedings of the Integrated Crop Management Conference

Recently, intensive water quality monitoring has demonstrated the presence of nitrate (N03-N) in surface and groundwater throughout the Midwestern U.S. (Hallberg, 1989).


Fall Vs Spring Application Of Nitrogen, Gyles W. Randall Dec 1992

Fall Vs Spring Application Of Nitrogen, Gyles W. Randall

Proceedings of the Integrated Crop Management Conference

Fall application of nitrogen (N) has been a way-of-life for many Upper Midwest farmers for a number of years. The primary advantages of fall compared to spring application are: (1) spread out the work load for both the farmer and dealer, (2) reduce potential soil compaction by eliminating another field operation in the spring, and (3) slight price advantages for fall application. But with the eight-month period between application and the time of greatest N uptake by com, the potential loss of N from the soil system increases. These potential losses lead to poorer economic return and contamination of surface ...


The Research Basis For Wisconsin's Legume Nitrogen Credits, K. A. Kelling, L. G. Bundy, R. P. Wolkowski Dec 1992

The Research Basis For Wisconsin's Legume Nitrogen Credits, K. A. Kelling, L. G. Bundy, R. P. Wolkowski

Proceedings of the Integrated Crop Management Conference

The ability of legumes to supply nitrogen to succeeding crops has been recognized for many years. The amount of actual N available will depend on the amount of N in the alfalfa and its availability, and any additional soil N that may be released due to the growth of the legume. From a practical standpoint, however, it is not the amount of N added to the system that is of primary importance. Much more important is the amount of N not needed by the com when the com is grown following the legume. This approach, commonly called the nitrogen fertilizer ...


Icon: A Interpreter-Based Approach, Dong Wei Dec 1992

Icon: A Interpreter-Based Approach, Dong Wei

Computer Science Technical Reports

This paper introduces the Icon programming language in a simplified form using a lisp-like syntax to represent an interesting subset of the language. The paper also discusses the semantics and implementation of some of Icon's advanced features with emphasis on generators and goal-directed evaluation. The organization of the paper resembles a chapter in the book ``Programming Languages: An Interpreter-Based Approach'' by Samuel Kamin. This paper can serve as a supplement to that book, allowing comparative programming language instructors who use the Kamin text to efficiently teach the Icon programming language


The Gati Client/Server Animation Toolkit, Changrajit L. Bajaj, Steve Cutchin Dec 1992

The Gati Client/Server Animation Toolkit, Changrajit L. Bajaj, Steve Cutchin

Department of Computer Science Technical Reports

No abstract provided.


Distributed Design Of Hip Protheses With Bhautik, Chandrajit L. Bajaj, Daniel R. Schikore Dec 1992

Distributed Design Of Hip Protheses With Bhautik, Chandrajit L. Bajaj, Daniel R. Schikore

Department of Computer Science Technical Reports

No abstract provided.


On Domains Of Superior Convergence Of The Ssor Method Over The Sor Method For P- Cyclic H-Matrices, Apostolos Hadjidimos, Michael Neumann Dec 1992

On Domains Of Superior Convergence Of The Ssor Method Over The Sor Method For P- Cyclic H-Matrices, Apostolos Hadjidimos, Michael Neumann

Department of Computer Science Technical Reports

No abstract provided.


Vertex Coloring For Weighted Graphs With Application To Timetabling, Lynn Kiaer, Jay Yellen Dec 1992

Vertex Coloring For Weighted Graphs With Application To Timetabling, Lynn Kiaer, Jay Yellen

Mathematical Sciences Technical Reports (MSTR)

This paper applies the methods of vertex coloring to timetabling problems


A Theory Of Global Concurrency Control In Multidatabase Systems, Aidong Zhang, Ahmed K. Elmagarmid Dec 1992

A Theory Of Global Concurrency Control In Multidatabase Systems, Aidong Zhang, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.


Royal Institute Of Technology: Department Of Polymer Technology, Otto Vogl, Ann Christine Albertsson Dec 1992

Royal Institute Of Technology: Department Of Polymer Technology, Otto Vogl, Ann Christine Albertsson

Emeritus Faculty Author Gallery

No abstract provided.


70. Obituary, Herman F. Mark, Otto Vogl Dec 1992

70. Obituary, Herman F. Mark, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.


Performance Of Landscape Plants From Yugoslavia In The North Central United States, Mark P. Widrlechner, Edward R. Hasselkus, Dale E. Herman, Jeffery K. Iles, John C. Pair, Ellen T. Paparozzi, Robert E. Schutzki, David K. Wildung Dec 1992

Performance Of Landscape Plants From Yugoslavia In The North Central United States, Mark P. Widrlechner, Edward R. Hasselkus, Dale E. Herman, Jeffery K. Iles, John C. Pair, Ellen T. Paparozzi, Robert E. Schutzki, David K. Wildung

NCRPIS Publications and Papers

From 1975 through 1979, 38 new, landscape plant introductions from Yugoslavia were distributed for testing in the NC-7 Regional Landscape Plant Trials. Twenty-seven of these introductions were evaluated for 10 years at seven or more sites, representing a broad range of environmental conditions in the north central United States. For these 27 introductions, first-year survival averaged 71%. Only four introductions had less than 50% first-year survival. Tenth-year survival varied widely among introductions and trial sites. Eight populations were adapted to most trial sites, ten populations were adapted to some sites, and nine populations were not adapted to any site. The ...