Design, Fabrication and Test of Multi-Fiber Laminates

Unidirectional and angleply multifiber laminates were tested for improved impact strength and other mechanical properties. The effects of several variables on the mechanical properties of epoxy matrix materials were described. These include fiber type (HMS and AS graphites, glass, and Kevlar 49), ratio of primary to hybridizing fiber and hybrid configuration. It is demonstrated that AS graphite/S glass in an intraply configuration results in the best combination of static and Charpy impact properties as well as superior ballistic impact resistance. Pendulum impact tests which were conducted on thin specimens are shown to produce different ranking of materials than tests conducted on standard thickness Charpy specimens. It is shown that the thin specimen results are in better agreement with the ballistic impact data. Additional static test data are reported as a function of temperature for the seven best hybrid configurations having epoxy, polyimide (PMR-15) and polyphenylquinoxaline resins as the matrix

Stationary structure of relativistic superfluid neutron stars

We describe recent progress in the numerical study of the structure of rapidly rotating superfluid neutron star models in full general relativity. The superfluid neutron star is described by a model of two interpenetrating and interacting fluids, one representing the superfluid neutrons and the second consisting of the remaining charged particles (protons, electrons, muons). We consider general stationary configurations where the two fluids can have different rotation rates around a common rotation axis. The previously discovered existence of configurations with one fluid in a prolate shape is confirmed.Comment: 5 pages, 2 figures. Conference proceedings for the 26th Spanish Relativity Meeting (ERE 2002), Menorca, Spain, 22-24 Sept. 200

Methyl chloride and the U.S. cigarette.

Various brands and types of cigarettes were purchased at retail locations in southern California. Volatile gas samples were analyzed using multicolumn/multidetector gas chromatography. Results showed methyl chloride (CH(3)Cl) levels as much as four orders of magnitude higher than typical urban levels, about 30-500 ppmv (1.5-5.3 mg/cigarette), compared with about 500 pptv in urban air. The concentration of CH(3)Cl correlated well with the levels of both CO (r (2) = 0.63) and CO(2) (r (2) = 0.77), showing the link between CH(3)Cl and combustion. In some brands, CH(3)Cl levels were well above the U.S. Environmental Protection Agency's maximum exposure limit of 200 ppmv. Light branded cigarettes tended to have higher CH(3)Cl levels than the heavier and filtered brands, possibly showing the dependence of cigarette packing on CH(3)Cl production. In addition, CH(3)Cl emitted from cigarette smoke may prove to be an important anthropogenic source of CH(3)Cl in the United States, at about 5%

Evaluating Alternative Safety Net Programs in Alberta: A Firm-level Simulation Analysis

This paper examines alternative risk management strategies in terms of their effectiveness for three representative Alberta farm operations. Stochastic dynamic simulation methods are used to model financial performance for these farms, and alternative risk management programs are compared in terms of their ability to stabilize returns, support income and reduce the probability of bankruptcy. The results suggest that government programs such as the Net Income Stabilization Account (NISA) program or the Farm Income Disaster Program (FIDP) in Alberta have some benefits in terms of supporting income levels and reducing the chances of farm failure. Neither program is very effective, however, in stabilizing year to year income or cash flow for the farm operations. As a risk management program, FIDP is more effective than NISA but this improved performance comes at the price of higher government costs. Performance of NISA and FIDP, relative to alternative risk management programs and strategies such as forward contracting or crop insurance, is mixed. In some cases, NISA does not seem to provide benefits beyond those available from other strategies, while FIDP tends to perform better than the alternatives. Finally, while increased debt load weakens firm financial performance, NISA and FIDP still provide some benefits in terms of supporting income and reducing the probability of bankruptcy.Farm Management, Risk and Uncertainty,

Flexible Pricing and Payment Alternatives on Canadian Wheat Board Pooling For Wheat

Crop Production/Industries, Marketing,

PORK RISK MANAGEMENT STRATEGIES FOR THE ALBERTA HOG INDUSTRY

Risk and Uncertainty,