Unique applications of fluoroepoxy materials

The following subject areas are covered: (1) fluoroepoxy and curing agents; (2) an excellent moisture vapor barrier coating; (3) as adhesives to bond Teflon without any surface treatment; (4) a new method to make thermosetting fluoropolymer foam; and (5) as a new antifoaming agent for epoxy material manufacturing and processing

Aeromechanical stability analysis of COPTER

A plan was formed for developing a comprehensive, second-generation system with analytical capabilities for predicting performance, loads and vibration, handling qualities, aeromechanical stability, and acoustics. This second-generation system named COPTER (COmprehensive Program for Theoretical Evaluation of Rotorcraft) is designed for operational efficiency, user friendliness, coding readability, maintainability, transportability, modularity, and expandability for future growth. The system is divided into an executive, a data deck validator, and a technology complex. At present a simple executive, the data deck validator, and the aeromechanical stability module of the technology complex were implemented. The system is described briefly, the implementation of the technology module is discussed, and correlation data presented. The correlation includes hingeless-rotor isolated stability, hingeless-rotor ground-resonance stability, and air-resonance stability of an advanced bearingless-rotor in forward flight

Using Swing Resistance and Assistance to Improve Gait Symmetry in Individuals Post-Stroke

A major characteristic of hemiplegic gait observed in individuals post-stroke is spatial and temporal asymmetry, which may increase energy expenditure and the risk of falls. The purpose of this study was to examine the effects of swing resistance/assistance applied to the affected leg on gait symmetry in individuals post-stroke. We recruited 10 subjects with chronic stroke who demonstrated a shorter step length with their affected leg in comparison to the non-affected leg during walking. They participated in two test sessions for swing resistance and swing assistance, respectively. During the adaptation period, subjects counteracted the step length deviation caused by the applied swing resistance force, resulting in an aftereffect consisting of improved step length symmetry during the post-adaptation period. In contrast, subjects did not counteract step length deviation caused by swing assistance during adaptation period and produced no aftereffect during the post-adaptation period. Locomotor training with swing resistance applied to the affected leg may improve step length symmetry through error-based learning. Swing assistance reduces errors in step length during stepping; however, it is unclear whether this approach would improve step length symmetry. Results from this study may be used to develop training paradigms for improving gait symmetry of stroke survivors

Essays on Determinants of IPO Liquidity and Price Adjustments to Persistent Information in Option Markets

I examine the determinants of cross-sectional liquidity in the IPO aftermarket during the period of 1995 through 2005. I find that past price performance, the extent of stock visibility, the mass of informed agents, and certain IPO attributes play a role in explaining IPO trading activity. My empirical evidence shows that differences of opinion and estimation uncertainty about an IPO firm affect little IPO liquidity. My findings contribute to the understanding of determinants of IPO aftermarket trading. I also investigate whether contemporaneous overreaction tends to occur following persistent information in the options market. More specifically, I compare the reactions between growth and value investors, and small and large investors conditional on past price reactions. My empirical results suggest that value investors react more strongly than growth investors following a series of prior information shocks, as measured by the cumulative level of overreaction. Small investors tend to react more strongly than large investors conditional on prior information shock, as measured by the cumulative sign or level of overreaction. The results imply that overreaction is a function of investor types and previous information and contribute to the overreaction hypothesis in the options market

Recent industrial development in China

Thesis (M.A.)--Boston University, 1949. This item was digitized by the Internet Archive

The relationship between root growth and nicotine content in leaves of burley tobacco

An experiment was carried out both in the field and in a green-house at the Tobacco Experiment Station, Greeneville, Tennessee, to determine the effect of root development on the concentration of nicotine in the leaves. In the field, plants of three genotypes were grown in Cumberland silt loam soil. Mature plant roots were dug and investigated by soil elution method. Root distribution, depth of penetration, and root yield were measured. Leaves and roots were dried and ground for nicotine analyses. Nicotine concentration was much lower for the roots in the soil of 0-30 centimeter depth than that for the roots distributed in the soil of 30-135 centimeter depth. Burley 49, which had a higher nicotine concentration in the leaves, was characterized by a greater ratio of fibrous root weight to the total weight of the root system and less tap root weight and lateral root weight or fewer number of lateral roots compared to the other two low alkaloid lines. These results suggested that nicotine is predominantly synthesized in the fibrous roots and is genetically controlled by each genotype. In the greenhouse, plants of three genotypes were grown in containers 35 centimeters in diameter and 60 centimeters in depth, which were filled with soil with three levels of compaction. Data were col-lected by the same method used in the field study. The extent of root growth for medium and heavy compactions were significantly greater than that for the light compaction. Total nicotine content in the leaves for the medium compaction was significantly higher than that for the other two compactions. Nicotine concentration in the leaves was not signifi-cantly affected by soil compaction. Correlation coefficients for the leaf yield and the root volume or root weight were positive and significant. Total nicotine content of the leaves was positively correlated with the root volume but only the correlation coefficient for the Burley 21 was statistically signifi-cant. Percentage nicotine in the leaves was not closely related to the extent of root growth

Thermomechanical properties of polymeric materials and related stresses

The thermomechanical properties of a number of widely used polymeric materials were determined by thermomechanical analysis and dynamic mechanical analysis. A combined profile of the coefficient of thermal expansion and the modulus change over a wide temperature range obtained by the analyses shows clearly the drastic effect of the glass transition on both the CTE and the modulus of a polymer, and the damaging potential due to such effect