Dynamics and instability of false vacuum bubbles

This paper examines the classical dynamics of false vacuum regions embedded in surrounding regions of true vacuum, in the thin-wall limit. The dynamics of all generally relativistically allowed solutions -- most but not all of which have been previously studied -- are derived, enumerated, and interpreted. We comment on the relation of these solutions to possible mechanisms whereby inflating regions may be spawned from non-inflating ones. We then calculate the dynamics of first order deviations from spherical symmetry, finding that many solutions are unstable to such aspherical perturbations. The parameter space in which the perturbations on bound solutions inevitably become nonlinear is mapped. This instability has consequences for the Farhi-Guth-Guven mechanism for baby universe production via quantum tunneling.Comment: 16 PRD-style pages including 11 embedded figures; accepted by PRD. Revised version includes new solution, discussion of 'thermal activation', added reference, fixed typo

Exploring Living-Learning Communities as a Venue for Men’s Identity Construction.

THIS QUALITATIVE STUDY EXPLORED how male undergraduate students experienced living-learning community environments. Findings revealed that living-learning communities provided men a safe haven from rigid gender role expectations, offered a plethora of involvement opportunities, and fostered relationships with faculty and peers. The findings highlight the potential of living-learning communities to provide men with the support they need to reject rigid gender expectations and develop a healthy identity. Recommendations for practice are discussed

Opportunities for CO2 equivalent emissions reductions via flare and vent mitigation: A case study for Alberta, Canada

AbstractGlobal flaring and venting of gas associated with petroleum production is a significant source of greenhouse gas emissions and airborne pollutants that has proven difficult to mitigate. This work examines the technical and economic potential for flaring and venting mitigation in a mature oil and gas producing region of the world. Using detailed monthly production data spanning the years 2002–2008 for 18,203 active production facilities, combined with geographic information system pipeline data, reservoir gas composition data, and cost data derived from industry sources, a case study was constructed to explore the technical and economic viability of further mitigation of flaring and venting associated with upstream oil and gas production in Alberta, Canada. Calculations were performed to evaluate the feasibility of mitigation via collection and compression of gas into pipelines to connect into existing pipeline networks. Four main calculation scenarios were considered, and for each, a series of Monte-Carlo analyses were performed to evaluate uncertainties and sensitivities to key calculation parameters. In all scenarios, the results reveal potentially significant opportunities for economically viable flare and vent mitigation that would yield substantial reductions in CO2 equivalent emissions. Because of the highly skewed distribution of gas volumes flared and vented at individual facilities, the results also show that solutions for comparatively small numbers of the largest facilities can offer large reductions in overall emissions from the sector. These results suggest that in a concerted effort to minimize carbon emissions in the upstream oil and gas industry, there is potential for significant near-term reductions using existing technology while research and development continues on more advanced methods such as carbon capture and storage

The Role of High School Experience in College Student Leadership Development

Colleges and universities have long claimed student leadership development to be a desirable college outcome. Until the latter quarter of the 20th century, college experiences that developed leadership outcomes were ill-structured, incidental or accidental, and largely only targeted students who held positional leadership roles