Letter to William Younger regarding Legal Bibliography Institute, May 8, 1972

A letter from R. Brunson to William Younger regarding Brunson\u27s plans to attend a Legal Bibliography Institute

Resistivity as Dynamic Behavior in Low Density Polyethylene

Bridging the gap between theoretical calculations and experimental data has been the focus of much of the research into the electrical behavior of insulating polymers. Low density polyethylene is the standard test material used in both experimental work and numerical calculations. Resistivity measurements provide more than an absolute value for technical use; they also provide insight into the nature of active charge carriers and trapping behavior within LDPE

Low Temperature Measurements of Resistivity in Low-Density Polythylene

Measurements of resistivity of low density polyethylene (LDPE) have been made using the standard constant voltage method to determine the temperature dependence of resistivity. Where electrons are assumed to serve as the primary charge carriers, their mobility is believed to be dependent on their probability of hopping between trapping sites treated as potential wells. We consider our measurements of this relatively simple polymeric material using temperaturedependant models of conduction mechanisms developed for amorphous solids and semiconductors

LOW TEMPERATURE MEASUREMENTS OF RESISTIVITY IN LOW-DENSITY POLYETHYLENE

Measurements of resistivity of low density polyethylene (LDPE) have been made using the standard constant voltage method to determine the temperature dependence of resistivity. Where electrons are assumed to serve as the primary charge carriers, their mobility is believed to be dependent on their probability of hopping between trapping sites treated as potential wells. We consider our measurements of this relatively simple polymeric material using temperature-dependant models of conduction mechanisms developed for amorphous solids and semi-conductors

E-Field Dependent Conduction in Low-Density Polyethylene

Measurements of the resistivity of low density polyethylene (LDPE) samples of varying thickness have been made using the standard constant voltage method to explore electric field dependence using conduction mechanisms developed for amorphous solids and semi-conductors. Resistivity is related to carrier mobility within the bulk. Where electrons are the primary charge carriers, their mobility is dependent on their probability of hopping between trapping sites treated as potential wells. A series of constant voltage measurements at constant temperature show that LDPE follows the Poole-Frenkel theory of field-enhanced conduction at low applied fields

Dependence of Resistivity in Low-Density Polyethylene on Space Environment Parameters

The conductivity of high-resistivity polymer films is dependent on the magnitude of applied electric field, repeated electric field exposure, and sample temperature. A traditional constant voltage method was used, maintained under vacuum to more closely resemble the space environment. Both the strength of the applied voltage and the thickness of low-density polyethylene (LDPE) samples were varied to determine the electric field dependence of internal polarization and the leakage current most appropriate in calculating the resistivity. Repetition of same field strength measurements determined the influence of sample history and charging memory. Measuring the resistivity from cryogenic temperatures to well above the glass transition temperature of LDPE allowed for separation of hopping conductivity regimes and correlation with internal morphology. In combination, these measurements provide a picture of the resistivity behavior of LDPE

Temperature and Electric Field Dependence of Conduction in Low-Density Polyethylene

A traditional constant voltage conductivity test method was used to measure how the conductivity of highly insulating low-density polyethylene (LDPE) polymer films depends on applied electric field, repeated and prolonged electric field exposure, and sample temperature. The strength of the applied voltage was varied to determine the electric field dependence. At low electric field, the resistivity was measured from cryogenic temperatures to well above the glass transition temperature. Comparisons were made with a variety of models of the conduction mechanisms common in insulators, including transient polarization and diffusion and steady-state thermally activated hopping conductivity and variable range hopping conductivity, to determine which mechanisms were active for LDPE and to provide a better picture of its electrical behavior

Break-Out Session 3: the Northern Rockies

Four characteristics of the Northern Rockies that are most important to ecosystem management are the large number of high-profile wildlife species, the diversity of ecological types, the rural socio-economic systems that are highly resource-based, and the fire-dependent natural systems. Potential constraints include the diversity of human values, insufficient knowledge about ecosystems, the tendency for political systems to produce solutions that are not ecologically optimal, and the prevalence of a utilitarian growth orientation coupled with anti-government sentiment. Characteristics most favorable for EM are the large amount of federal ownership, abundant research opportunities, a growing public recognition of the need to make environmental progress, and recognition among the agencies of the need for partnerships

Engaging Faculty in Preparing Students for Non-Academic Environmental Careers

As a biology major at New York University, I was introduced to ecology in a course that bused the class out of New York University\u27s Greenwich Village campus every weekend, to investigate biodiversity patterns in nearby forests and wetlands. After a day crossing bogs and walking through forests, I would take the subway home, hip boots in hand, reflecting on how the day\u27s activities connected to my routine city life. Engaging others in understanding the city connections to adjacent habitats became my life\u27s work. As Dean of Arts and Sciences at a public liberal arts university, I encourage faculty and students to engage in connecting classroom knowledge to real‐world problem solving, as required in non‐academic environmental careers. – CR

HELWAVE: High Efficiency Low Wake Aquatic Vehicle Exterior

This project seeks to find if it is possible to apply soliton theory to reduce or eliminate surface disturbances that a watercraft produces as it moves. It aimed to do so by developing several unique hull shapes crafted from the principles of soliton theory that were optimized for different sizes and styles of vessel. The solitons used were derived from sets of partial differential equations whose solution has the unique ability to maintain its shape as it propagates. Through a combination of modeling programs and advanced manufacturing methods, students created physical and computer models to test the soliton boat design. Utilizing Embry-Riddle’s new non-linear wave lab, students were able to take measurements using high definition and high speed cameras in such a way that the fluid flow around the ship could be recorded. In combination with computer simulations, this quantitative data was analyzed and resulted in HELWAVE’s conclusion surrounding the application of solitons