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1991

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Articles 1 - 30 of 1427

Full-Text Articles in Physical Sciences and Mathematics

How To Pick Out The Integers In The Rationals: An Application Of Number Theory To Logic, Daniel Flath, Stan Wagon Feb 2008

How To Pick Out The Integers In The Rationals: An Application Of Number Theory To Logic, Daniel Flath, Stan Wagon

Stan Wagon, Retired

No abstract provided.


Unix And Security: The Influences Of History, Eugene H. Spafford Dec 1991

Unix And Security: The Influences Of History, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.


Three Letters On Computer Security And Society, Eugene H. Spafford Dec 1991

Three Letters On Computer Security And Society, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.


A Study In Systems Integration Architecture, Sashidhar M. Prasad Dec 1991

A Study In Systems Integration Architecture, Sashidhar M. Prasad

Theses

This Thesis studies the two architectures OSCA and ANSA which support the ODPSE principle in the first two parts. In the third part the framework for integrating these two architectures is described. The idea of integration architectures in relation to open architectures is studied using the enabling technologies.


Biomass Conversion Of Solid-Waste (Newsprint) Into A Clean Fuel (Ethanol) By Enzymic Hydrolysis And Fermentation, Nimesh V. Gandhi Dec 1991

Biomass Conversion Of Solid-Waste (Newsprint) Into A Clean Fuel (Ethanol) By Enzymic Hydrolysis And Fermentation, Nimesh V. Gandhi

Theses

A feasibility study has been performed with two bioprocesses for conversion of newsprint waste to an environmentally safe fuel (ethyl alcohol) and carbon dioxide.

The following areas were investigated to accomplish this task: one hour pretreatment of newsprint by attrition, saccharification of paper slurry to glucose by cellulase and cellobiase, effects of pH, temperature and concentration of enzymes on conversion of paper to sugar, fermentation of glucose to ethanol and carbon dioxide by immobilized yeast, and simultaneous saccharification and fermentation of paper to ethanol and carbon dioxide using enzymes and immobilized yeast.

Results indicate that the enzymic hydrolysis of newsprint ...


User Authentication And Related Topics: An Annotated Bibliography, Eugene H. Spafford, Stephen A. Weeber Dec 1991

User Authentication And Related Topics: An Annotated Bibliography, Eugene H. Spafford, Stephen A. Weeber

Department of Computer Science Technical Reports

No abstract provided.


Paint Stripper Composition Having Reduced Volatility Containing Decanolactone, N-Methylpyrrolidone And Butyrolactone And Method Of Use, Harvest L. Collier, Gary L. Bertrand, Raymond L. Venable Dec 1991

Paint Stripper Composition Having Reduced Volatility Containing Decanolactone, N-Methylpyrrolidone And Butyrolactone And Method Of Use, Harvest L. Collier, Gary L. Bertrand, Raymond L. Venable

Chemistry Faculty Research & Creative Works

An improved composition of matter and method of use for removing cured coatings of paint or varnish or other similar coatings from substrates. The composition comrpises chlorinated solvent paint strippers (especially methylene chloride (CH2CI2)), waxes and an additive selected from the group consisting of decanolactone (C10H18O2), N-methylpyrrolidone (CH3NCH2CH2CH2CH2) and butyrolactone (OCH2CH2CH2CO). The additive retards the evaporation of the solvent resulting in a composition that is environmentally less hazardous to a user and also resulting in improved stripping ...


Magnetic Response Of A Single, Isolated Gold Loop, V. Chandrasekhar, Richard A. Webb, M. J. Brady, M. B. Ketchen, W. J. Gallagher, A. Kleinsasser Dec 1991

Magnetic Response Of A Single, Isolated Gold Loop, V. Chandrasekhar, Richard A. Webb, M. J. Brady, M. B. Ketchen, W. J. Gallagher, A. Kleinsasser

Faculty Publications

Measurements have been made of the low-temperature magnetic response of single, isolated, micron-size Au loops. The magnetic response is found to contain a component which oscillates with the applied magnetic flux with a fundamental period of Φ0=h/e. The amplitude of the oscillatory component corresponds to a persistent current of ≃(0.3–2.0)evF/L, 1 to 2 orders of magnitude larger than predicted by current theories.


Scaling Behavior In Shaving Cream, Douglas J. Durian, D. A. Weitz, D. J. Pine Dec 1991

Scaling Behavior In Shaving Cream, Douglas J. Durian, D. A. Weitz, D. J. Pine

Department of Physics Papers

The coarsening of a three-dimensional foam is studied with multiple light-scattering techniques. Scaling behavior is observed with the average bubble diameter growing in time as tz where z=0.45±0.05. Changes in the packing conditions during coarsening give rise to a dynamical process that also exhibits temporal scaling. Neighboring bubbles undergo sudden structural rearrangement events at a rate per unit volume that decays as t−y where y=2.0±0.2.


A Note On Many-One And 1-Truth-Table Complete Languages, Steven Homer, Stuart A. Kurtz, James S. Royer Dec 1991

A Note On Many-One And 1-Truth-Table Complete Languages, Steven Homer, Stuart A. Kurtz, James S. Royer

Electrical Engineering and Computer Science - Technical Reports

The polynomial time 1-tt complete sets for EXP and RE are polynomial time many-one complete.


Identification Of Reconstruction In Pt Films Deposited On Pd(110) At Room Temperature, P. J. Schmitz, W.-Y. Leung, H.-C. Kang, Patricia A. Thiel Dec 1991

Identification Of Reconstruction In Pt Films Deposited On Pd(110) At Room Temperature, P. J. Schmitz, W.-Y. Leung, H.-C. Kang, Patricia A. Thiel

Chemistry Publications

We have studied the properties of Pt films on Pd(110), grown by deposition at 300 K and annealed up to 900 K, using low-energy electron diffraction and Auger-electron spectroscopy. We observe (1×2) and (1×3) superstructures, depending upon Pt coverage and annealing temperature. At one monolayer, the (1×1) periodicity is unperturbed. Between one and three monolayers, a broad and streaky (1×2) develops upon annealing, then fades to (1×1) as the film dissolves. At three monolayers and above, the broad and streaky (1×2) splits to a (1×3), then fades again to (1×1) at ...


Soil Compaction Research Summary, Stewart W. Melvin, Donald C. Erbach Dec 1991

Soil Compaction Research Summary, Stewart W. Melvin, Donald C. Erbach

Proceedings of the Integrated Crop Management Conference

Soil compaction has become a major topic of discussion among scientists and crop producers in recent years. Even though some producers consider soil compaction to be a problem on their own farms, they feel resigned to the fact that there is little they can do to control it. Some recent solutions have been offered based on research efforts with soil compaction. There is significant interest in developing crop production systems with controlled traffic to help control the problem of soil compaction. There have also been new machine developments to address the problem of soil compaction, particularly with rubber tracked equipment ...


Factors Affecting Agricultural Chemical Losses To Surface And Ground Water Resources, J. L. Baker, J. L. Hatfield Dec 1991

Factors Affecting Agricultural Chemical Losses To Surface And Ground Water Resources, J. L. Baker, J. L. Hatfield

Proceedings of the Integrated Crop Management Conference

The major chemical factors determining concentrations and losses of agricultural chemicals from cropland are their persistence and adsorption to soil. The major hydrologic factors are rate and route of infiltration. The major management factors are the rate, method, timing, and choice of applied chemicals; cropping; and tillage system. To determine the "Best Management Practices" (BMPs) to reduce chemical losses, their mechanisms of interactions with the soil and management practices must be understood. Depending on soil adsorption, pesticides and nutrients can be mostly lost with surface runoff water, sediment, or water percolating out of the root zone (water which may return ...


Impact Of Tillage, Crop Rotation, And Chemical Management Practices On Groundwater Quality, Rameshwar S. Kanwar Dec 1991

Impact Of Tillage, Crop Rotation, And Chemical Management Practices On Groundwater Quality, Rameshwar S. Kanwar

Proceedings of the Integrated Crop Management Conference

Contamination of groundwater by nitrate and pesticides has been documented by various state and federal agencies in the United States. Groundwater pollution is of increasing concern in the United States because about 50 percent of the drinking water comes from groundwater. A recent study suggested that water pollution is the most damaging and widespread environmental effect of agricultural production. Recent research conducted in Iowa and surrounding states has indicated the incidence of groundwater contamination by pesticides and nitrogen fertilizers (Baker and Johnson, 1981; Everts and Kanwar, 1990; Gast et al., 1978; Hallet al., 1989; Hallberg, 1989; Kanwar et al., 1985a ...


Structural Characterization Of Mixed Alkali Metal Bis(Trimethylsilyl)Amide Bases., Paul Williard, Michael Nichols Dec 1991

Structural Characterization Of Mixed Alkali Metal Bis(Trimethylsilyl)Amide Bases., Paul Williard, Michael Nichols

Michael A Nichols

No abstract provided.


The Combinatorics Of Algebraic Splines, Chanderjit L. Bajaj Dec 1991

The Combinatorics Of Algebraic Splines, Chanderjit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.


Visualization Of Four Dimensional Space And Its Applications (Ph.D. Thesis), Jianhua Zhou Dec 1991

Visualization Of Four Dimensional Space And Its Applications (Ph.D. Thesis), Jianhua Zhou

Department of Computer Science Technical Reports

No abstract provided.


Japan-U.S. Seminar On Polymer Synthesis, Otto Vogl, Hiroyuki Nishide Dec 1991

Japan-U.S. Seminar On Polymer Synthesis, Otto Vogl, Hiroyuki Nishide

Otto Vogl

No abstract provided.


Computing At Lehigh, Lehigh University Dec 1991

Computing At Lehigh, Lehigh University

Computing Center Newsletter

No abstract provided.


Soil Surveys And Related Investigations In The Ord River Area, East Kimberley, 1944, George Henry Burvill Dec 1991

Soil Surveys And Related Investigations In The Ord River Area, East Kimberley, 1944, George Henry Burvill

Technical Bulletins

No abstract provided.


Undergraduates, The Right Questions, And Cayley Produce Results, Gary J. Sherman Dec 1991

Undergraduates, The Right Questions, And Cayley Produce Results, Gary J. Sherman

Mathematical Sciences Technical Reports (MSTR)

During the summers of 1989, 1990, and 1991, eighteen undergraduates participated in a National Science Foundation Research Experiences for Undergraduates program at Rose-Hulman for which the author was the principal investigator. This paper provides some examples of the mathematics discovered during these three summers and discusses the philosophy, environment and process which made these discoveries possible.


Specifying Interdatabase Dependencies In A Multidatabase Environment, Marek Rusinkiewicz, Amit P. Sheth, George Karabatis Dec 1991

Specifying Interdatabase Dependencies In A Multidatabase Environment, Marek Rusinkiewicz, Amit P. Sheth, George Karabatis

Kno.e.sis Publications

The problem of interdatabase dependencies and the effect they have on applications updating interdependent data are addressed. A model that allows specifications of constraints among multiple databases in a declarative fashion is proposed. The separation of the constraints from the application programs facilitates the maintenance of data constraints and allows flexibility in their implementation. It allows investigation of various mechanisms for enforcing the constraints, independently of the application programs. By grouping the constraints together, it is possible to check their completeness and discover possible contradictions among them. The concepts of polytransactions, which use interdatabase dependencies to generate a series of ...


Environmental Radiocesium In Subarctic And Arctic Alaska Following Chernobyl, M. Baskaran, J. J. Kelley, A. S. Naidu, D. F. Holleman Dec 1991

Environmental Radiocesium In Subarctic And Arctic Alaska Following Chernobyl, M. Baskaran, J. J. Kelley, A. S. Naidu, D. F. Holleman

Geology Faculty Research Publications

Radiocesium (¹³⁴ Cs and ¹³⁷ Cs) concentrations were measured in soil, plant and wildlife samples from subarctic to arctic Alaska. Concentrations of ¹³⁷ Cs ranged from below detectable or low levels in whale and fish samples to as high as 242 Bq/kg in lichen. For all potential human food items, the radiocesium concentrations measured in this study were below accepted permissible levels for human consumption. Chernobyl-derived radiocesium concentrations ranged from below detectable or low levels in all arctic samples (soil, sediment, lichen, whale, fish and caribou) to 32 Bq/kg in subarctic moss. Therefore the distribution and subsequent deposition ...


Polymer Research In Austria. I: Introduction And The Facilities, Otto Vogl, Josef Schurz, Bernd Thrattnigg, Klaus Hummel, Wolfgang Daimler, Klaus Lederer Dec 1991

Polymer Research In Austria. I: Introduction And The Facilities, Otto Vogl, Josef Schurz, Bernd Thrattnigg, Klaus Hummel, Wolfgang Daimler, Klaus Lederer

Emeritus Faculty Author Gallery

No abstract provided.


Japan-U.S. Seminar On Polymer Synthesis, Otto Vogl, Hiroyuki Nishide Dec 1991

Japan-U.S. Seminar On Polymer Synthesis, Otto Vogl, Hiroyuki Nishide

Emeritus Faculty Author Gallery

No abstract provided.


Polymer Research In Austria. I: Introduction And The Facilities, Otto Vogl, Josef Schurz, Bernd Thrattnigg, Klaus Hummel, Wolfgang Daimler, Klaus Lederer Dec 1991

Polymer Research In Austria. I: Introduction And The Facilities, Otto Vogl, Josef Schurz, Bernd Thrattnigg, Klaus Hummel, Wolfgang Daimler, Klaus Lederer

Otto Vogl

No abstract provided.


Electron-Energy And –Angular Distributions In The Double Photoionization Of Helium, R. Wehlitz, Franz Heiser, Oliver Hemmers, B. Langer, A. Menzel, U. Becker Dec 1991

Electron-Energy And –Angular Distributions In The Double Photoionization Of Helium, R. Wehlitz, Franz Heiser, Oliver Hemmers, B. Langer, A. Menzel, U. Becker

Environmental Studies Faculty Publications

Photoelectron spectra of helium have been measured at different angles and at various energies above the double-ionization threshold up to 120 eV to investigate the behavior of the energy and angular distributions, of shake-off electrons. Both energy and angular distributions clearly show a U-shaped profile which turns to a flat curve near threshold pointing to a uniform intensity distribution over the kinetic energy for all angles in this excitation energy regime. Our results for the angular-distribution asymmetry parameter indicate qualitative agreement with theoretical predictions but fail to provide them quantitatively.


Stream Of Consciousness (1991), Alliance For Aquatic Resource Monitoring (Allarm) Dec 1991

Stream Of Consciousness (1991), Alliance For Aquatic Resource Monitoring (Allarm)

Stream of Consciousness

Stream of Consciousness is a publication from the Alliance for Aquatic Resource Monitoring (ALLARM) at Dickinson College.

Table of Contents

Drought and Its Effect on Stream Health

It's All in the Rocks! / by Candie Wilderman

Energy Bill Rejected / by Christy White

Activists' Corner

Networking Opportunity

Did You Know... / by John Meckley

ALLARM and Founder Receive EPA Award / by Matthew Kloiber

CAPHE Grant Awarded / by Jennifer Litton

Available to Members

Annual Board Meeting Successful

Financial Report

Meet the Staff


Surface Structure Of √3x√3r 30 Cl/Ni(111) Determined Using Low-Temperature Angle-Resolved-Photoemission Extended Fine Structure, Li-Qiong Wang, Z. Hussain, Z. Q. Huang, A. E. Schach Von Wittenau, Dennis W. Lindle, D. A. Shirley Dec 1991

Surface Structure Of √3x√3r 30 Cl/Ni(111) Determined Using Low-Temperature Angle-Resolved-Photoemission Extended Fine Structure, Li-Qiong Wang, Z. Hussain, Z. Q. Huang, A. E. Schach Von Wittenau, Dennis W. Lindle, D. A. Shirley

Chemistry and Biochemistry Faculty Publications

A surface structural study of the √3 × √3 R30° Cl/Ni(111) adsorbate system was made using low-temperature angle-resolved photoemission extended fine structure. The experiments were performed along two emission directions, [111] and [110], and at two temperatures, 120 and 300 K. The multiple-scattering spherical-wave analysis determined that the Cl atom adsorbs in the fcc threefold hollow site, 1.837(8) Å above the first nickel layer, with a Cl-Ni bond length of 2.332(6) Å, and an approximate 5% contraction between the first and the second nickel layers (the errors in parentheses are statistical standard deviations only).


Ecological Aspects Of Burrowing Owl Nesting Strategies In The Nebraska Panhandle, Martha J. Desmond Dec 1991

Ecological Aspects Of Burrowing Owl Nesting Strategies In The Nebraska Panhandle, Martha J. Desmond

Dissertations & Theses in Natural Resources

No abstract provided.