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1994

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Articles 31 - 60 of 2016

Full-Text Articles in Physical Sciences and Mathematics

Polymer Institute Slovak Academy Of Sciences Bratislava, Slovakia, Otto Vogl Dec 1994

Polymer Institute Slovak Academy Of Sciences Bratislava, Slovakia, Otto Vogl

Otto Vogl

No abstract provided.


64. Tibor Kelen, Otto Vogl Dec 1994

64. Tibor Kelen, Otto Vogl

Otto Vogl

No abstract provided.


Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service Dec 1994

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …


Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service Dec 1994

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …


Depositional History Of The Eocene Chumstick Formation - Implications Of Tectonic Partitioning For The History Of The Leavenworth And Entiat-Eagle Creek Fault Systems, Washington, James E. Evans Dec 1994

Depositional History Of The Eocene Chumstick Formation - Implications Of Tectonic Partitioning For The History Of The Leavenworth And Entiat-Eagle Creek Fault Systems, Washington, James E. Evans

School of Earth, Environment and Society Faculty Publications

The Chumstick basin opened as an extensional half-graben prior to 51 Ma, and was subsequently modified by two episodes of tectonic partitioning of drainage prior to basin deformation. Initially, westward flowing fluvial systems formed a unified depositional system with the Swauk basin. Tectonic partitioning of drainage at 51-49 Ma and at 44-42 Ma was controlled by localized uplift on the Leavenworth (LFZ), Eagle Creek (ECFZ), and Entiat (EFZ) fault zones and led in each instance to the truncation of regional depositional systems, modification and reversal of paleoflow, and internal drainage. Relief on the LFZ at 51-49 Ma may be the …


Transportable Agents, Keith D. Kotay, David Kotz Dec 1994

Transportable Agents, Keith D. Kotay, David Kotz

Dartmouth Scholarship

As network information resources grow in size, it is often most efficient to process queries and updates at the site where the data is located. This processing can be accomplished by using a traditional client-server network interface, which constrains the client to the set of queries supported by the server, or requires the server to send all data to the client for processing. The former is inflexible; the latter is inefficient. Transportable agents, which support the movement of the client computation to the location of the remote resource, have the potential to be more flexible and more efficient. Transportable agents …


Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan Dec 1994

Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

In an effort to increase achievable postdetection signal-tonoise ratios (SNRs) of continuous-wave, 1-gm all-solid-state ladar systems, a prototype rare-earth-doped optical-fiber amplifier has been included in the optical return signal path of both a heterodyne and a directdetection ladar system. We provide numerical predictions for SNR increases according to our previously developed theory. We also detail our experimental efforts and provide the results of SNR measurements for four distinct cases: direct ladar detection with and without a fiber amplifier, and heterodyne ladar detection with and without a fiber amplifier. Experimentally measured increases in SNRs for ladar systems incorporating an optical-fiber amplifier …


Geology Newsletter- 1994, Department Of Geology Dec 1994

Geology Newsletter- 1994, Department Of Geology

Geological and Environmental Sciences News

Vol. 1, No. 19

  • Faculty News
  • Awards and Scholarships
  • Alumni/ Friends/ Former Faculty Notes
  • Geology Development and Scholarship Donations


Discrete Symmetries And Isosinglet Quarks In Low-Energy Supersymmetry, Diego Castano, Stephan P. Martin Dec 1994

Discrete Symmetries And Isosinglet Quarks In Low-Energy Supersymmetry, Diego Castano, Stephan P. Martin

Chemistry and Physics Faculty Articles

Many extensions of the minimal supersymmetric standard model contain superfields for quarks which are singlets under weak isospin with electric charge -13. We explore the possibility that such isosinglet quarks have low or intermediate scale masses, but do not mediate rapid proton decay because of a discrete symmetry. By imposing the discrete gauge anomaly cancellation conditions, we show that the simplest way to achieve this is to extend the Z3 “baryon parity” of Ibáñez and Ross to the isosinglet quark superfields. This can be done in three distinct ways. This strategy is not consistent with grand unification with a …


Interactive Shape Control And Rapid Display Of A-Patches, Chandrajit L. Bajaj, Jindon Chen, Guoliang Xu Dec 1994

Interactive Shape Control And Rapid Display Of A-Patches, Chandrajit L. Bajaj, Jindon Chen, Guoliang Xu

Department of Computer Science Technical Reports

No abstract provided.


Ariadne User Manual Version 2.0, Edward Mascarenhas, Vernon J. Rego, Vaidy Sunderam Dec 1994

Ariadne User Manual Version 2.0, Edward Mascarenhas, Vernon J. Rego, Vaidy Sunderam

Department of Computer Science Technical Reports

No abstract provided.


Display User Manual Version 1.1, Edward Mascarenhas, Vernon J. Rego Dec 1994

Display User Manual Version 1.1, Edward Mascarenhas, Vernon J. Rego

Department of Computer Science Technical Reports

No abstract provided.


Topologies Invariant Under A Group Action, Paul Bankston Dec 1994

Topologies Invariant Under A Group Action, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

We study links between faithful group actions on a set and topologies on that set. In one direction, a group action has its invariant topologies (so we may regard members of the action to be homeomorphisms relative to those topologies); in the other direction, a topology has its preserving group actions (i.e., the subgroups of the homeomorphism group of the topology). This two-way passage allows us to discuss topological features of group actions as well as symmetry features of topologies.


Toward Scalable Parallel Software: An Active Object Model And Library To Support Von Neumann Languages, George K. Thiruvathukal Dec 1994

Toward Scalable Parallel Software: An Active Object Model And Library To Support Von Neumann Languages, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

Scalable parallel processing has been proposed as the technology scientists and engineers can use today to solve the problems of tomorrow. Many computational Grand Challenge problems require between two and three orders of magnitude than can be provided with the scalable parallel hardware of the early nineteen-nineties. While hardware continues to become more scalable and cheaper, software is not advancing at the same pace and remains a very expensive part of systems development.

A great deal of emphasis on software technology to support scalable parallel processing is placed on von Neumann languages. One of two approaches is common: (a) augment …


The Pollution Effects Of Pleasure/Work Boat Sewage Discharges On Fecal Contamination Levels Of Waters In And Around Marinas And Other Places Where Boats Are Moored On The Eastern Shore Of Virginia, George H. Bangs Dec 1994

The Pollution Effects Of Pleasure/Work Boat Sewage Discharges On Fecal Contamination Levels Of Waters In And Around Marinas And Other Places Where Boats Are Moored On The Eastern Shore Of Virginia, George H. Bangs

Community & Environmental Health Theses & Dissertations

Contamination of seafood harvested from and recreational areas of the Chesapeake Bay, its tributaries and the Atlantic coast inshore waters may cause health problems for people consuming the seafood or coming in contact with the waters by swimming, water skiing, or other water sports. These health problems include, but not limited to, dysentery, typhoid and hepatitis (Natchez, 1990). This is a preliminary study into the level of fecal pollution generated by sewage discharges from boats in marinas and other places where boats are moored on the Eastern Shore of Virginia. Sites selected for the study included; (I) marinas and other …


Autonomous Robot Navigation In Unknown Terrains Using Parallel Numerical Artificial Potential Fields, John C. Schneider Dec 1994

Autonomous Robot Navigation In Unknown Terrains Using Parallel Numerical Artificial Potential Fields, John C. Schneider

Computer Science Theses & Dissertations

We present a new artificial potential field formulation for resolution complete robot navigation that unifies the purely geometric path planning problem with the lower level force control problem. Our formulation is designed for numerical computation over a massively parallel mesh of processors and is responsive to newly discovered terrain features. It does not suffer from many of the problems commonly associated with potential fields and with adequate resolution provides provably correct, collision free convergence to the goal. In addition, our formulation supports many desirable, practical features required for implementation, such as bounded actuator torques, attainable incremental constructability, realizable computation and …


A Bootstrap Method To Analyze An Intervention Model With Autoregressive Error Terms, Scott D. Mcknight Dec 1994

A Bootstrap Method To Analyze An Intervention Model With Autoregressive Error Terms, Scott D. Mcknight

Dissertations

The analysis of a particular time-series intervention model involving lag one autoregressive (AR(1)) error terms is the focus of this dissertation. The method of ordinary least squares, and several two stage procedures that are commonly used to analyze this intervention model are examined. The two stage Cochrane-Orcutte, Durbin, and generalized least squares procedures each requires estimation of the AR(1) parameter in stage one before hypothesis testing about the intervention parameters can be performed in stage two. Using Monte Carlo experiments we show that the AR(1) estimates commonly used in these procedures are poor and consequently the stage two hypothesis tests …


The Theory And Applications Of Stratified Graphs, Reza Rashidi Dec 1994

The Theory And Applications Of Stratified Graphs, Reza Rashidi

Dissertations

Physical design is one of several stages in the design of a VLSI chip. In this stage, the specifications of an electrical circuit are converted into a geometrical model. Problems concerning the physical design stage can often be studied by means of graphs. The problems encountered here are routing problems and concern placement of vertices, which represent wires, into layers. All this gives rise to a class of graphs whose vertices are partitioned into classes. Such graphs are called stratified graphs. In this dissertation, we formally define stratified graphs, study their properties, and investigate various algorithmic problems related to these …


Geological And Hydrogeological Characterization Of The Schoolcraft Aquifer, Schoolcraft, Michigan, William K. Steinmann Dec 1994

Geological And Hydrogeological Characterization Of The Schoolcraft Aquifer, Schoolcraft, Michigan, William K. Steinmann

Masters Theses

Newly installed monitoring wells, county well logs, gamma-ray logs, head measurements, flow nets, slug tests, and full aquifer pumping tests were utilized to characterize the geologic and hydrogeologic conditions of the area. Evaluation of the geologic conditions indicate that the study area is best described as a glacially generated, humid type, alluvial fan. A hydrogeologic facies model concept aided in the initial evaluation of the hydrogeologic conditions and was utilized for the placement of several vertically nested monitoring wells. Further evaluation indicates an unconfined aquifer comprised of two separate flow systems: a shallow, local flow system interacting with flow-through surface …


The Photonic Band Structure Of Dielectric Systems With A Frequency Dependent Dielectric Function, Jiezhou Liu Dec 1994

The Photonic Band Structure Of Dielectric Systems With A Frequency Dependent Dielectric Function, Jiezhou Liu

Masters Theses

The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagaiting in periodic dielectric structures with a frequency independent dielectric function. These periodic structures can produce photonic band gaps in which the propagation of electromagnetic waves is strictly prohibited. The introduction of a frequency dependent dielectric function in such systems gives rise to strong changes of the photonic bands in the neighborhood of the frequency resonance of the dielectric function.

In my thesis, the photonic band structure of a dielectric system with a frequency dependent dielectric function which undergoes a dielectric resonance will …


High Breakdown Rank-Based Estimates For Linear Models, William H. Chang Dec 1994

High Breakdown Rank-Based Estimates For Linear Models, William H. Chang

Dissertations

No abstract provided.


Review Of "Modern Physics From Α To Z°" By J. W. Rohlf, Peter J. Collings Dec 1994

Review Of "Modern Physics From Α To Z°" By J. W. Rohlf, Peter J. Collings

Physics & Astronomy Faculty Works

No abstract provided.


Energy Spread And Ion Current Measurements Of Several Ion Sources, A. D. Gaus, W. T. Htwe, J. A. Brand, Timothy J. Gay, M. Schulz Dec 1994

Energy Spread And Ion Current Measurements Of Several Ion Sources, A. D. Gaus, W. T. Htwe, J. A. Brand, Timothy J. Gay, M. Schulz

Timothy J. Gay Publications

Energy spread and extracted current measurements are presented for five different types of ion sources: hot cathode, cold cathode, magnetron, microwave, and electron cyclotron resonance (ECR). The measurements were performed with a 45° parallel-plate energy analyzer with a resolution of better than 0.5 eV at 500 eV incident energy. Energy spreads ranged from 0.5 to 4 eV, while total extracted beam currents ranged from 2 to 30 μA. Beam currents due specifically to protons, 3He++ ions, and H+2 ions are also presented. The ECR and magnetron sources gave the best overall performance. These, along with the …


Electron-Beam-Induced Patterned Deposition Of Allylcyclopentadienyl Palladium Using Scanning Tunneling Microscopy, D.S. Saulys, A. Ermakov, E.L. Garfunkel, Peter A. Dowben Dec 1994

Electron-Beam-Induced Patterned Deposition Of Allylcyclopentadienyl Palladium Using Scanning Tunneling Microscopy, D.S. Saulys, A. Ermakov, E.L. Garfunkel, Peter A. Dowben

Peter Dowben Publications

Scanning tunneling microscopy has been used to study the electron-induced decomposition of allylcyclopentadienyl palladium [Pd(η3-C3H5)( η5-C5H5)] and subsequent deposition on a Si(111) surface. Deposition occurs via an electron impact mechanism on either the tip or surface, depending on the bias polarity, and is observed with voltages of 2.75 V. This is close to the predicted condensed phase dissociation energy of 2.3 eV for Pd(η3-C3H5)(η5-C5H5)→Pd+C3H5+C5H5. Metallic deposits of nanometer …


Subsurface Glacial Geology Of The Area Between The Tekonsha And Kalamazoo Moraines, Kalamazoo County, Michigan, Kim Finkbeiner Dec 1994

Subsurface Glacial Geology Of The Area Between The Tekonsha And Kalamazoo Moraines, Kalamazoo County, Michigan, Kim Finkbeiner

Masters Theses

Cross sections profiling the stratigraphy of the glacial sediments were created using the geological logs recorded on water well records. Glacial sediments in the study area comprise a large outwash complex between two moraines. The surficial landforms are the result of the last Wisconsinan advance and retreat through the area.

Cross sections contructed for this project reveal at least three major till units. An additional till unit contains a weathered soil sequence. Therefore, it is possible that this paleosol represents the Sangamon Interglacial period between the Wisconsinan and Illinoian stages. No obvious evidence of movement of the Saginaw Lobe remains …


Portable, High-Bandwidth Frequency-Domain Photon Migration Instrument For Tissue Spectroscopy, Steen J. Madsen, Eric R. Anderson, Richard C. Haskell, Bruce J. Tromberg Dec 1994

Portable, High-Bandwidth Frequency-Domain Photon Migration Instrument For Tissue Spectroscopy, Steen J. Madsen, Eric R. Anderson, Richard C. Haskell, Bruce J. Tromberg

All HMC Faculty Publications and Research

We describe a novel frequency-domain photon migration instrument employing direct diode laser modulation and avalanche photodiode detection, which is capable of noninvasively determinating the optical properties of biological tissues in near real time. An infinite medium diffusion model was used to extract absorption and transport scattering coefficients from 300-kHz to 800-MHz photon-density wave phase data. Optical properties measured in tissue-simulating solutions at 670 nm agreed to within 10% of those expected.


A Survey Of Source And Finished Water Supplies For Giardia Cysts And Cryptosporidium Oocysts, Lisa Martin Sexton Dec 1994

A Survey Of Source And Finished Water Supplies For Giardia Cysts And Cryptosporidium Oocysts, Lisa Martin Sexton

KWRRI Research Reports

The occurrence of Giardia lamblia cysts and Cryptosporidium parvum oocysts was determined from source and treated drinking water supplies at selected water treatment facilities in Eastern Kentucky. Giardia and Cryptosporidium are two human protozoan parasites often found in water supplies due to fecal contamination. Characteristic cysts and oocysts were identified from large volume water samples, typically 100 gallons for raw samples and 1,000 gallons for finished water, using an indirect fluorescent antibody specific for Giardia and Cryptosporidium. Source water from four different water treatment facilities utilizing a reservoir, river, and two creeks were assayed. All sites exhibited Giardia lamblia …


Sorption Of Chlorinated Organic Compounds By Sedimentary Rocks, Paul M. Mcginley, S. Kesaraju, Ronald D. Gruzesky Dec 1994

Sorption Of Chlorinated Organic Compounds By Sedimentary Rocks, Paul M. Mcginley, S. Kesaraju, Ronald D. Gruzesky

KWRRI Research Reports

The sorption of dichlorobenzene and trichlorobenzene on carbonate and shale rocks collected in Kentucky demonstrate that rock organic matter content is a good indicator of sorptive reactivity in rock systems. Although this is similar to soil systems, significant differences between sorption in rock and soil systems exist. Sorption isotherms on these rocks are nonlinear and sorption can be an order of magnitude higher than predicted using correlations from soils and their organic matter content. This sorption reaction could lead to significant concentration tailing during contaminant cleanup. Experimental elution of trichloroethylene from rock filled columns verified that cleanup times might be …


The Fat-Pyramid And Universal Parallel Computation Independent Of Wire Delay, Ronald I. Greenberg Dec 1994

The Fat-Pyramid And Universal Parallel Computation Independent Of Wire Delay, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

This paper shows that a fat-pyramid of area Θ(A) requires only O(log A) slowdown to simulate any competing network of area A under very general conditions. The result holds regardless of the processor size (amount of attached memory) and number of processors in the competing networks as long as the limitation on total area is met. Furthermore, the result is valid regardless of the relationship between wire length and wire delay. We especially focus on elimination of the common simplifying assumption that unit time suffices to traverse a wire regardless of its length, since the assumption becomes more and more …


Review Of “Linear Programming And Related Problems” By E. Nering And A. W. Tucker, Stephen B. Maurer Dec 1994

Review Of “Linear Programming And Related Problems” By E. Nering And A. W. Tucker, Stephen B. Maurer

Mathematics & Statistics Faculty Works

No abstract provided.