Thin Film Formation During Splashing of Viscous Liquids

After impact onto a smooth dry surface, a drop of viscous liquid initially spreads in the form of a thick lamella. If the drop splashes, it first emits a thin fluid sheet that can ultimately break up into droplets causing the splash. Ambient gas is crucial for creating this thin sheet. The time for sheet ejection, $t_{ejt}$, depends on impact velocity, liquid viscosity, gas pressure and molecular weight. A central air bubble is trapped below the drop at pressures even below that necessary for this sheet formation. In addition, air bubbles are entrained underneath the spreading lamella when the ejected sheet is present. Air entrainment ceases at a lamella velocity that is independent of drop impact velocity as well as ambient gas pressure.Comment: 8 pages, 11 figure

Ultrafast Interference Imaging of Air in Splashing Dynamics

A drop impacting a solid surface with sufficient velocity will emit many small droplets creating a splash. However, splashing is completely suppressed if the surrounding gas pressure is lowered. The mechanism by which the gas affects splashing remains unknown. We use high-speed interference imaging to measure the air beneath all regions of a spreading viscous drop as well as optical absorption to measure the drop thickness. Although an initial air bubble is created on impact, no significant air layer persists until the time a splash is created. This suggests that splashing in our experimentally accessible range of viscosities is initiated at the edge of the drop as it encroaches into the surrounding gas

A CLASS OF SEPARABILITY FLEXIBLE FUNCTIONAL FORMS

Quadratic flexible forms, such as the translog and generalized Leontief, are separability inflexible. That is, separability restrictions render them inflexible with regard to separable structures. A class functional forms is proposed that is flexible with regard to general production structures and remains flexible regarding weakly separable structures when separability restrictions are imposed, thus permitting tests of the separability hypothesis. Additionally, the restricted forms are parsimonious; that is they contain the minimum number of parameters with which flexibility can be achieved.Research Methods/ Statistical Methods,

Cross-border diversification in bank asset portfolios

Taking the mean-variance portfolio model as a benchmark, we compute the optimally diversified portfolio for banks located in France, Germany, the U.K., and the U.S. under different assumptions about currency hedging. We compare these optimal portfolios to the actual cross-border assets of banks from 1995-1999 and try to explain the deviations. We find that banks over-invest domestically to a considerable extent and that cross-border diversification entails considerable gain. Banks underweight countries which are culturally less similar or have capital controls in place. Capital controls have a strong impact on the degree of underinvestment whereas less political risk increases the degree of over-investment. JEL Classification: G21, G11, E44, F40International banking, international integration, portfolio diversification

Cross-Border Diversification in Bank Asset Portfolios

Taking the mean-variance portfolio model as a benchmark, we compute the optimally diversified portfolio for banks located in France, Germany, the U.K., and the U.S. under different assumptions about currency hedging. We compare these optimal portfolios to the actual cross-border assets of banks from 1995-1999 and try to explain the deviations. We find that banks over-invest domestically to a considerable extent and that cross-border diversification entails considerable gain. Banks underweight countries which are culturally less similar or have capital controls in place. Capital controls have a strong impact on the degree of underinvestment whereas less political risk increases the degree of over-investment.international banking, portfolio diversification, international integration

Analysis of San Luis Obispo Housing Elements

This project focuses on analysis and recommendations for housing elements within San Luis Obispo County. The project details housing element requirements made by the State of California Housing and Community Development Department and how the incorporated cities of San Luis Obispo meet these requirements. Cities analyzed include Arroyo Grande, Atascadero, Grover Beach, Morro Bay, Paso Robles, Pismo Beach, and San Luis Obispo

An Analysis of the Effectiveness of Online Peer Feedback at the United States Air Force Academy

This thesis explores the effectiveness of the Air Force Academy\u27s Department of English local area network peer feedback system. Four main questions were examined. These questions explored a) whether students reported improvement in their writing, b) whether students reported that feedback is worthwhile, c) whether students reported that LAN sessions increase enjoyment of writing, and d) what types of feedback the students 1) received and 2) found most helpful. Three groups were studied. Forty-six students received feedback online, fifty students received feedback face to face, and thirty-three students did not receive feedback. Comparisons were made for the questions mentioned above to see if there was any difference in the responses based on the method of feedback the students received. The results of the study suggest that students\u27 perceived writing improvement is not affected by the peer feedback program. Peer feedback is successful in that students who participate find it to be worthwhile and at least one group believes that it makes writing more enjoyable. Finally, the two feedback groups reported receiving and wanting different types of feedback. The online group receives and prefers feedback on content, and the face to face group receives and prefers feedback on flow