Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2001

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1021 - 1050 of 3030

Full-Text Articles in Physical Sciences and Mathematics

Cross-Linking Of Polystyrene By Friedel-Crafts Chemistry: Reaction Of P-Hydroxymethylbenzyl Chloride With Polystyrene, Hongyang Yao, Michael A. Mckinney, Caroline Dick, John J. Liggat, C.E. Snape, Charles A. Wilkie Jun 2001

Cross-Linking Of Polystyrene By Friedel-Crafts Chemistry: Reaction Of P-Hydroxymethylbenzyl Chloride With Polystyrene, Hongyang Yao, Michael A. Mckinney, Caroline Dick, John J. Liggat, C.E. Snape, Charles A. Wilkie

Chemistry Faculty Research and Publications

p-Hydroxymethylbenzyl chloride was found to be an effective cross-linking agent for polystyrene. The reaction was found to occur by Friedel–Crafts alkylation between the benzyl alcohol/chloride functional groups in the additive and phenyl ring in polystyrene. The reaction was studied by TGA–IR to monitor the evolution of hydrogen chloride and water, and the structure of the resultant gel was analyzed by solid state NMR and elemental analysis. The potential application in flame-retardancy was evaluated using Cone calorimetry.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 9, June 2001, College Of Engineering And Computer Science, Wright State University Jun 2001

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 9, June 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Parity Violation In Neutron Resonances Of 117 Sn, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, Mikkel B. Johnson, A Masaike, Y Matsuda, G E. Mitchell, V A. Nazarenko, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, L M. Smotritsky, Sharon L. Stephenson, S Tomsovic, V W. Yuan Jun 2001

Parity Violation In Neutron Resonances Of 117 Sn, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, Mikkel B. Johnson, A Masaike, Y Matsuda, G E. Mitchell, V A. Nazarenko, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, L M. Smotritsky, Sharon L. Stephenson, S Tomsovic, V W. Yuan

Physics and Astronomy Faculty Publications

Parity nonconservation (PNC) has been studied in neutron p-wave resonances of 117Sn. The longitudinal asymmetries were measured for 29 p-wave resonances in the neutron energy range 0.8 eV to 1100 eV. Statistically significant PNC effects were observed for four resonances. A statistical analysis determined the rms weak mixing matrix element and the weak spreading width. A weak spreading width of Γw=(0.28-0.15+0.56)×10-7 eV was obtained for117Sn.


Market-Based Control Of Mobile-Agent Systems, Jonathan L. Bredin Jun 2001

Market-Based Control Of Mobile-Agent Systems, Jonathan L. Bredin

Dartmouth College Ph.D Dissertations

Modern distributed systems scatter sensors, storage, and computation throughout the environment. Ideally these devices communicate and share resources, but there is seldom motivation for a device's owner to yield control to another user. We establish markets for computational resources to motivate principals to share resources with arbitrary users, to enforce priority in distributed systems, to provide flexible and rational limitations on the potential of an application, and to provide a lightweight structure to balance the workload over time and between devices. As proof of concept, we implement a structure software agents can use to discover and negotiate access to networked …


Low-Flow Test, San Juan River, Final Environmental Assessment, United States Department Of Interior, Bureau Of Reclamation Jun 2001

Low-Flow Test, San Juan River, Final Environmental Assessment, United States Department Of Interior, Bureau Of Reclamation

All U.S. Government Documents (Utah Regional Depository)

This final environmental assessment (EA) is prepared in compliance with the National Environmental Policy Act (NEPA) of 1969 (Public Law 91-190) to evaluate test flows from Navajo Dam into the San Juan River.

The underlying need for this proposed test is to evaluate the effect of low summer flows on various resources. The information obtained will be used in preparation of an environmental impact statement (EIS) on operating Navajo Reservoir to mimic a natural hydrograph in critical habitat of the San Juan River for the benefit of downstream endangered fish and to allow for future water development.


Territorial Defense By Coyotes (Canis Latrans) In Yellowstone National Park, Wyoming: Who, How, Where, When, And Why, Eric M. Gese Jun 2001

Territorial Defense By Coyotes (Canis Latrans) In Yellowstone National Park, Wyoming: Who, How, Where, When, And Why, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

Territorial defense and maintenance are an important facet of the social ecology of most carnivore species. From January 1991 to June 1993, we observed 54 coyotes (Canis latrans) for 2507 h in Yellowstone National Park, Wyoming, during which we observed 112 instances of territory defense. The identity of the coyotes involved in challenging and evicting intruding animals was known. Alpha coyotes were most likely to be involved in territorial evictions of intruding animals, followed by beta individuals; pups participated little in territory defense. Coyotes evicting intruders generally had a numerical advantage when challenging the intruders. Territory-defense rates were …


Evaluation Of Mirrors To Deter Nesting Starlings, Thomas W. Seamans, Charles D. Lovell, Richard A. Dolbeer, Jonathon D. Cepek Jun 2001

Evaluation Of Mirrors To Deter Nesting Starlings, Thomas W. Seamans, Charles D. Lovell, Richard A. Dolbeer, Jonathon D. Cepek

United States Department of Agriculture Wildlife Services: Staff Publications

European starlings (Sturnus vulgaris) nesting in buildings and other structures can cause health, nuisance, and safety problems. We evaluated effectiveness of flashing lights combined with mirrors, and mirrors alone, as deterrents for starlings nesting in starling nest boxes in northern Ohio, 1998-2000. Each year, 100 nest boxes attached to utility poles were randomly assigned equally among 4 treatments (including untreated boxes): 1998- mirrored (internally placed on the back and 2 side walls of nest boxes), mirrored with red-flashing lights, and mirrored with green-flashing lights; 1999-convex mirror above entrance hole, convex mirror at back of nest box, and flat …


Biotechnology Of Whey Using Yeast Fungi Isolated From Local Environment, Mouza Suhail Al Muhairi Jun 2001

Biotechnology Of Whey Using Yeast Fungi Isolated From Local Environment, Mouza Suhail Al Muhairi

Theses

The potential threat of whey pollution to the soil environment and ultimately groundwater resources in UAB promoted the elements of concern to the utilization of the whey waste. This work was conducted in AI-Ain area to isolate new fermenting yeast strains, from local soils, capable of fermenting whey lactose.

Soil samples were collected from two locations in AI-Ain area (near Al-Ain dairy farm & AI-Markhania area) and from a neighboring area (AI-Buraimi) based on the soil nature and ecological parameters. Inorganic elements and organic residues of the soil samples were characterized. Results indicated that AI-Buraimi soil is rich in nitrate …


Scaling In One-Dimensional Localized Absorbing Systems, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky Jun 2001

Scaling In One-Dimensional Localized Absorbing Systems, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

Numerical study of the scaling of transmission fluctuations in the one-dimensional localization problem in the presence of absorption is carried out. Violations of single-parameter scaling for lossy systems are found and explained on the basis of a new criterion for different types of scaling behavior derived by Deych et al.


Forecasting Life And Death: Juror Race, Religion, And Attitude Toward The Death Penalty, Theodore Eisenberg, Stephen P. Garvey, Martin T. Wells Jun 2001

Forecasting Life And Death: Juror Race, Religion, And Attitude Toward The Death Penalty, Theodore Eisenberg, Stephen P. Garvey, Martin T. Wells

Cornell Law Faculty Publications

Determining whether race, sex, or other juror characteristics influence how capital case jurors vote is difficult. Jurors tend to vote for death in more egregious cases and for life in less egregious cases no matter what their own characteristics. And a juror's personal characteristics may get lost in the process of deliberation because the final verdict reflects the jury's will, not the individual juror's. Controlling for the facts likely to influence a juror's verdict helps to isolate the influence of a juror's personal characteristics. Examining each juror's first sentencing vote reveals her own judgment before the majority works its will. …


Hillsborough Independent Monitoring Program Technical Memorandum Lower Hillsborough River Benthic Monitoring 2000, Stephen A. Grabe, David J. Karlen, Christina M. Holden, Barbara Goetting Jun 2001

Hillsborough Independent Monitoring Program Technical Memorandum Lower Hillsborough River Benthic Monitoring 2000, Stephen A. Grabe, David J. Karlen, Christina M. Holden, Barbara Goetting

Reports

The Lower Hillsborough River system has been heavily impacted by stormwater discharges and reduction of freshwater inflow (Mote Marine Laboratory 1984; Water & Air Research Inc. 1993; Water & Air Research & SOl Environmental Services, Inc. 1994) .. A consequence has been increased salinity, the accumulation of fine-grained sediments and associated contaminants, as well as lowered DO levels. Analysis of past EPCHC data for the Lower Hillsborough River showed that benthic community characteristics (as measured by the TBBI) were not necessarily related to dissolved oxygen, salinity, or depth (Grabe and Karlen 1999; Grabe el al. 2000). The data collected through …


Single-Sided Noninvasive Inspection Of Multielement Sample Using Fan-Beam Multiplexed Compton Scatter Tomography, Matthew A. Lange Jun 2001

Single-Sided Noninvasive Inspection Of Multielement Sample Using Fan-Beam Multiplexed Compton Scatter Tomography, Matthew A. Lange

Theses and Dissertations

As aircraft age, corrosion forms upon unobservable surfaces, particularly at the junction of the sheet aluminum and the steel rivets used to attach the sheets to the airframe, degrading the aircraft s airworthiness. Previous research developed a noninvasive technique for the evaluation of the material composition of aluminum surfaces, utilizing the information encoded in the energy spectra of Compton-scattered gamma emissions. The spectra are gathered by a six-element, high purity germanium detector array. A, first principles, deterministic computer code is used to reconstruct a two-dimensional map of the electron density of aluminum samples. Previous efforts, to image pure aluminum samples, …


Time-Resolved Photoluminescence Of Inas/Gainsb Quantum Well Lasers, Michael R. Mckay Jun 2001

Time-Resolved Photoluminescence Of Inas/Gainsb Quantum Well Lasers, Michael R. Mckay

Theses and Dissertations

In the world of semiconductor photonic device fabrication, one important objective may be to extract as much light as possible from the device. In these devices, photons are created when electrons recombine with holes by transitioning from a high-energy state to a lower one. Unfortunately, electron-hole recombination does not always result in the formation of a photon. There are three basic types of recombination: the first results in the formation of a photon and is called radiative recombination; and the second and third, known as Shockley-Read-Hall and Auger recombination, result in the heating of the device and do not produce …


A Directory Infrastructure To Support Mobile Services, Ammar Khalid Jun 2001

A Directory Infrastructure To Support Mobile Services, Ammar Khalid

Dartmouth College Undergraduate Theses

Traditional Voice-over-IP applications such as Microsoft NetMeeting assume that the user is on a machine with a fixed IP address. If, however, the user connects to the Internet, via a wireless network, on a handheld device, his IP address frequently changes as he moves from one subnet to another. In such a situation, we need a service that can be queried for the most current IP address of a person whom we wish to contact. In this project, we design and implement such a directory service. The service authenticates all callers and callees, is robust against most host failure, and …


Measuring Early Usage Of Dartmouth's Wireless Network, Pablo Stern Jun 2001

Measuring Early Usage Of Dartmouth's Wireless Network, Pablo Stern

Dartmouth College Undergraduate Theses

In Spring 2001, Dartmouth College installed a campus-wide 802.11b wireless network. To understand how that network is used, we examined the usage characteristics of the network over a five-week period. We monitored access points to determine user behavior, and user and network traffic characteristics. Because our study coincided with the deployment of the access points, our analysis captures the growth of a wireless network. The results of this study help understand the behavior of mobile users and provide a reference to network engineers wishing to deploy and expand similar wireless networks.


An Implementation Of Object-Oriented Program Transformation For Thought-Guided Debugging, Tiffany M. Wong Jun 2001

An Implementation Of Object-Oriented Program Transformation For Thought-Guided Debugging, Tiffany M. Wong

Dartmouth College Undergraduate Theses

This paper presents our design and implementation of program transformation for C++ that will be used in the context of a thought-guided debugging system. The program uses a lexical analyzer written in Flex and a grammar written in Bison that work in conjunction to scan the inputted C++ code for function definitions and class definitions. The code is then transformed to produce trace information for each defined function, while the original functionality of the code is left untouched. We also implement two additional data structures that are used for information storage during the course of the program.


Fastab: Solving The Pitch To Notation Problem, Jeremy I. Robin Jun 2001

Fastab: Solving The Pitch To Notation Problem, Jeremy I. Robin

Dartmouth College Undergraduate Theses

I have always been frustrated with the length of time necessary to notate a piece of music. Computers have simplified so many other aspects of our lives, it seems that they should be able to simplify this task as well. In fact, there are already two distinct ways that engineers have attempted to attack this problem. The first analyzes the waveform generated by microphone input and relies on Fourier Analysis and other similar methods. The other examines the analog signal generated by a electric guitar-like pickup placed beneath the strings. The method used by Fastab relies much less on the …


Meyer-Neldel Rule For Dark Current In Charge-Coupled Devices, Ralf Widenhorn, Lars Mündermann, Armin Rest, Erik Bodegom Jun 2001

Meyer-Neldel Rule For Dark Current In Charge-Coupled Devices, Ralf Widenhorn, Lars Mündermann, Armin Rest, Erik Bodegom

Physics Faculty Publications and Presentations

We present the results of a systematic study of the dark current in each pixel of a charged-coupled device chip. It was found that the Arrhenius plot, at temperatures between 222 and 291 K, deviated from a linear behavior in the form of continuous bending. However, as a first approximation, the dark current, D, can be expressed as: D=Dₒ exp(−ΔE/kT),where ΔE is the activation energy, k is Boltzmann’s constant, and T the absolute temperature. It was found that ΔE and the exponential prefactor Dₒ follow the Meyer–Neldel rule (MNR) for all of the more than 222,000 investigated pixels. The isokinetic …


Genetic Algorithms For Communications Network Design - An Empirical Study Of The Factors That Influence Performance, Hsinghua Chou, G. Premkumar, Chao-Hsien Chu Jun 2001

Genetic Algorithms For Communications Network Design - An Empirical Study Of The Factors That Influence Performance, Hsinghua Chou, G. Premkumar, Chao-Hsien Chu

Research Collection School Of Computing and Information Systems

We explore the use of GAs for solving a network optimization problem, the degree-constrained minimum spanning tree problem. We also examine the impact of encoding, crossover, and mutation on the performance of the GA. A specialized repair heuristic is used to improve performance. An experimental design with 48 cells and ten data points in each cell is used to examine the impact of two encoding methods, three crossover methods, two mutation methods, and four networks of varying node sizes. Two performance measures, solution quality and computation time, are used to evaluate the performance. The results obtained indicate that encoding has …


Hillsborough Independent Monitoring Program Technical Memorandum Palm River Benthic Monitoring 2000, Stephen A. Grabe, David J. Karlen, Christina M. Holden, Barbara Goetting Jun 2001

Hillsborough Independent Monitoring Program Technical Memorandum Palm River Benthic Monitoring 2000, Stephen A. Grabe, David J. Karlen, Christina M. Holden, Barbara Goetting

Reports

The EPCHC proposed an increase in benthic macro invertebrate sampling in the Palm River during the three "wet seasons" preceding the initiation of withdrawals, to be followed by at least three years of post-diversion sampling. This technical memorandum summarizes data collected during the August 2000 sampling period and complements data collected in prior years (Grabe & Karlen 1999; Karlen et al. 2000).


Apoptosis Following Peripheral Sensory Deafferentation In The Olfactory Blub Of Adult Zebrafish, Danio Rerio, Akiko M. Vankirk Jun 2001

Apoptosis Following Peripheral Sensory Deafferentation In The Olfactory Blub Of Adult Zebrafish, Danio Rerio, Akiko M. Vankirk

Masters Theses

Removal of the olfactory organ in the adult zebrafish results in a significant decrease in volume of the ipsilateral olfactory bulb. Our lab has been investigating the potential role of apoptosis in this phenomenon. My hypothesis is that cells in the adult olfactory bulb normally undergo minimal apoptosis and that apoptosis will increase when sensory stimulation is removed. The TUNEL method allowed detection of cells undergoing DNA-fragmentation, which indicates an apoptotic response. Double-label immunohistochemistry was used to mark which apoptotic cells are neurons by using antibody to Hu, a neuron specific protein. Triple-labeling with bis-benzirnide confirmed the apoptotic nature of …


Surface Modification Of Diamond And Determination Of Kinetics And Mechanism Of Modification Reactions, Humera Farooq Jun 2001

Surface Modification Of Diamond And Determination Of Kinetics And Mechanism Of Modification Reactions, Humera Farooq

Masters Theses

A series of photochemically modified diamond surfaces were prepared. Surface functional groups added included, chlorine, bromine, methoxy, amine, methylamine, dimethylarnine and trimethylammonium chloride. Photochemically chlorinated and brominated diamond surfaces were used as synthetic intermediates. The modified diamond surfaces were characterized by Diffuse Reflectance Infrared Spectroscopy (DRIFT) and X-ray Photoelectron Spectroscopy (XPS).

The study was mainly focused on understanding the kinetic processes and reaction mechanism of modified surfaces. The observed rate constants for surface hydrogen loss and HCl (g) evolution were found to be identical. Similar rate constants were observed for amine substitution and consumption of ammonia.

The study of action …


The Geochemistry Of A Leaf Composting Leachate Plume, Asylum Lake, Kalamazoo, Michigan, Eric G. Steeves Jun 2001

The Geochemistry Of A Leaf Composting Leachate Plume, Asylum Lake, Kalamazoo, Michigan, Eric G. Steeves

Masters Theses

Since the implementation of legislation that bans yard waste from landfills, there has been a need to characterize the impact that large scale composting has on groundwater quality. Allen (1993) and Weaver (1995) have attempted to characterize a leaf composting leachate plume located at the WMU-Asylum Lake Well Field #2 in Kalamazoo, Michigan. Allen was not able to base any conclusions on geochemical results and Weaver delineated the plume using fewer monitoring wells than are now available.

The data from twenty-one monitoring wells indicates that local groundwater is being impacted by the large-scale composting operation. The plume is characterized by …


In Situ Biosurfactant Production At Carson City Park, Michigan, Andrew J. Hudak Jun 2001

In Situ Biosurfactant Production At Carson City Park, Michigan, Andrew J. Hudak

Masters Theses

Crude oil refining operations conducted by the Crystal Refining Company in Carson City, Michigan have led to the contamination of the soil and groundwater at Carson City Park with petroleum hydrocarbons. In situ biosurfactant production, occurring as a result of the biodegradation activities of hydrocarbon degrading microorganisms, was investigated.

Background hydrogeological and biogeochemical data were collected from the groundwater from thirteen monitoring wells at Carson City Park. Further analysis included the identification of biosurfactant producing microorganisms and biosurfactants present in the soil and groundwater.

Results showed that Pseudomonas aeruginosa was producing both monorhamnolipids and dirhamnolipids (glycolipid biosurfactants) in the contaminated …


Globally Convergent Approximate Dynamic Programming Applied To An Autolander, J.J. Murray, Richard Saeks, C.J. Cox, George G. Lendaris Jun 2001

Globally Convergent Approximate Dynamic Programming Applied To An Autolander, J.J. Murray, Richard Saeks, C.J. Cox, George G. Lendaris

Systems Science Faculty Publications and Presentations

A globally convergent nonlinear Approximate Dynamic Programming algorithm is described, and an implementation of the algorithm in the linear case is developed. The resultant linear Approximate Dynamic Programming algorithm is illustrated via the design of an autolander for the NASA X-43 research aircraft, without a priori knowledge of the X-43's flight dynamics.


Effect Of Exponential Averaging On The Variability Of A Red Queue, Archan Misra, Teunis Ott, John Baras Jun 2001

Effect Of Exponential Averaging On The Variability Of A Red Queue, Archan Misra, Teunis Ott, John Baras

Research Collection School Of Computing and Information Systems

The paper analyzes how using a longer memory of the past queue occupancy in computing the average queue occupancy affects the stability and variability of a RED queue. Extensive simulation studies with both persistent and Web TCP sources are used to study the variance of the RED queue as a function of the memory of the averaging process. Our results show that there is very little performance improvement (and in fact, possibly significant performance degradation) if the length of memory is increased beyond a very small value. Contrary to current practice, our results show that a longer memory reduces the …


Implementation And Performance Evaluation Of Telemip, Kaushik Chakraborty, Archan Misra, Subir Das, Anthony J. Mcauley, Ashutosh Dutta, Sajal K. Das Jun 2001

Implementation And Performance Evaluation Of Telemip, Kaushik Chakraborty, Archan Misra, Subir Das, Anthony J. Mcauley, Ashutosh Dutta, Sajal K. Das

Research Collection School Of Computing and Information Systems

In this paper, we present our implementation of TeleMIP a two-level architecture for IP based mobility management TeleMIP essentially uses an Intra-Domain Mobility Management Protocol IDMP for managing mobility within a domain and Mobile IP for supporting inter-domain global mobility. Unlike other proposed schemes for intra-domain mobility management IDMP uses two care of addresses for mobility management The global care of address is relatively stable and identifies the mobile nodes current domain[1] while the local care of address changes every time the mobile changes subnets and identifies the mobiles current point of attachment. The paper describes our TeleMIP implementation based …


Mobile Voice Over Ip (Mvoip): An Application-Level Protocol, Ayorkor Mills-Tettey Jun 2001

Mobile Voice Over Ip (Mvoip): An Application-Level Protocol, Ayorkor Mills-Tettey

Dartmouth College Undergraduate Theses

Current Voice over Internet Protocol (VOIP) protocols require participating hosts to have fixed IP addresses for the duration of a VOIP call. When using a wireless-enabled host, such as a tablet computer on an 802.11 wireless network, it is possible for a participant in a VOIP call to roam around the network, moving from one subnet to another and needing to change IP addresses. This address change creates the need for mobility support in VOIP applications. We present the design of Mobile Voice over IP (MVOIP), an application-level protocol that enables such mobility in a VOIP application based on the …


Dassfnet: An Extension To Dassf For High-Performance Network Modeling, Mehmet Iyigun Jun 2001

Dassfnet: An Extension To Dassf For High-Performance Network Modeling, Mehmet Iyigun

Dartmouth College Undergraduate Theses

Scalable Simulation Framework (SSF) is a discrete-event simulation framework providing a unified programming interface geared towards network simulation. Dartmouth SSF (DaSSF) is a C++ implementation of SSF, designed for simulating very large-scale multi-protocol communication networks. As of the latest release, DaSSF lacks many features present in SSF and this prevents it from achieving mainstream use. To alleviate this shortcoming we designed and implemented DaSSFNet which extends DaSSF to the levels of functionality found in SSF. In this paper, we show that DaSSFNet and SSFNet are identical in operation given the same input. We also show that DaSSFNet is about twice …


Infopipes—An Abstraction For Information Flow, Jie Huang, Andrew P. Black, Jonathan Walpole, Calton Pu Jun 2001

Infopipes—An Abstraction For Information Flow, Jie Huang, Andrew P. Black, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

Building Object-Oriented Distributed Systems has been facilitated by Remote Message Sending (RMS) systems like Java RMI and implementations of CORBA. However, RMS systems are designed to support request/response interactions. Streaming applications, in contrast, are characterized by high-bandwidth, long-duration communication with stringent performance requirements. Examples of streaming applications include video-on-demand, teleconferencing, on-line education, and environmental observation. These applications transfer huge amounts of data and focus on distributed information flow rather than request/response.

To simplify the task of building distributed streaming applications, we propose a new abstraction for information flow—Infopipes. Using Infopipes, information flow becomes the heart of the system, not an …