Terrestrial planet formation in low eccentricity warm-Jupiter systems

We examine the effect of giant planet migration on the formation of inner terrestrial planet systems. We consider situations in which the giant planet halts migration at semi-major axes in the range 0.13 - 1.7 AU due to gas disk dispersal. An N-body code is employed that is linked to a viscous gas disk algorithm capable of simulating: gas loss via accretion onto the central star and photoevaporation; gap formation by the giant planet; type II migration of the giant; optional type I migration of protoplanets; gas drag on planetesimals. We find that most of the inner system planetary building blocks survive the passage of the giant planet, either by being shepherded inward or scattered into exterior orbits. Systems of one or more hot-Earths are predicted to form and remain interior to the giant planet, especially if type II migration has been limited, or where type I migration has affected protoplanetary dynamics. Habitable planets in low eccentricity warm-Jupiter systems appear possible if the giant planet makes a limited incursion into the outer regions of the habitable zone (HZ), or traverses its entire width and ceases migrating at a radial distance of less than half that of the HZ's inner edge. We conclude that Type II migration does not prevent terrestrial planet formation.Comment: Accepted for publication in A&A; 18 pages, 12 figures, 2 table

On the formation of terrestrial planets in hot-Jupiter systems

We present a series of calculations aimed at examining how an inner system of planetesimals/protoplanets, undergoing terrestrial planet formation, evolves under the influence of a giant planet undergoing inward type II migration through the region bounded between 5 - 0.1 AU. We find that > 60% of the solids disk survives by being scattered by the giant planet into external orbits. Planetesimals are scattered outward almost as efficiently as protoplanets, resulting in the regeneration of a solids disk where dynamical friction is strong and terrestrial planet formation is able to resume. A simulation extended for a few Myr after the migration of the giant planet halted at 0.1 AU, resulted in an apparently stable planet of ~ 2 Earth masses forming in the habitable zone. Migration-induced mixing of volatile-rich material from beyond the `snowline' into the inner disk regions means that terrestrial planets that form there are likely to be water-rich. We predict that hot--Jupiter systems are likely to harbor water-rich terrestrial planets in their habitable zones. These planets may be detected by future planet search missions.Comment: 18 pages, 13 figures. Higher resolution pdf available at http://www.users.globalnet.co.uk/~mfogg/fogg_nelson2.pd

The Lifetime Employment and Earnings Consequences of Dropping Out of High School in Philadelphia

What's the difference between a Philadelphia graduate and a high school dropout? About $580,000, according to this study which shows the difference in net fiscal contribution over a working lifetime (tax revenue generated vs. tax revenue received) between a Philadelphia student who earns a diploma and one who does not. This research report also offers information on the percentage of students in Philadelphia who do not graduate from high school, the difference in lifetime earnings between high school graduates and high school dropouts, and the likelihood of employment for high school graduates compared to high school dropouts

The Tax and Transfer Fiscal Impacts of Dropping Out of High School in Philadelphia City and Suburbs

This research article provides detailed information on the effects of the escalating high school drop out rate in Philadelphia. High school dropouts impose very high costs on the broader community. This report details these costs, including: These costs include: lower tax payments to the government, intensive reliance on cash and non-cash government income transfers, and the cost of incarceration. In addition, this article demonstrates how the fiscal consequences of dropping out of high school have been exacerbated by changes in the economy

Air Rage: Is It A Global Problem? What Proactive Measures Can Be Taken To Reduce Air Rage, And Whether The Tokyo Convention Should Be Amended To Ensure Prosectuion Of Air Rage Offenders?

Air rage is a fairly recent phenomenon gaining domestic and international scrutiny in an area of increasing importance and interest to the traveling publi

An evaluation of two testing techniques and their influence on achievement in science and on some aspects of critical thinking

Thesis (Ed.D.)--Boston Universit

Variation in Permeability and Treatability in Shortleaf Pine and Yellow Poplar

Superficial gas permeability determinations were made for longitudinal, radial, and tangential flow on samples removed from different heights, radii, and distances along the radii in a young and a mature shortleaf pine (Pinus echinata Mill.) and in a yellow poplar (Liriodendron tulipifera L.). Permeability was measured at a mean pressure of 2.2 atmospheres and the wood was maintained at about 18% moisture content. Some of the samples were then pressure-treated with creosote under controlled conditions to estimate treatability. Specific gravity and latewood per cent were also determined. In the young pine, position in the tree showed no effect on permeability, whereas in the mature pine a slight increase with height and a sharp increase with distance from the pith were detected. In yellow poplar, an increase of permeability with distance outwards along the radius was detected, but no consistent height change. Treatability, particularly retention, was moderately correlated with permeability, particularly in shortleaf pine. In yellow poplar, inclusion of permeability values for all three structural directions was necessary to obtain correlation. All relationships were improved by transforming the permeability logarithmically. Specific gravity and latewood relationships with permeability were conflicting. Use of a mean pressure higher than atmospheric appeared to be advantageous in permeability determinations

Evidence of traffic-related pollutant control in soil-based Sustainable Urban Drainage Systems (SUDS)

SUDS are being increasingly employed to control highway runoff and have the potential to protect groundwater and surface water quality by minimising the risks of both point and diffuse sources of pollution. While these systems are effective at retaining polluted solids by filtration and sedimentation processes, less is known of the detail of pollutant behaviour within SUDS structures. This paper reports on investigations carried out as part of a co-ordinated programme of controlled studies and field measurements at soft-engineered SUDS undertaken in the UK, observing the accumulation and behaviour of traffic-related heavy metals, oil and PAHs. The field data presented were collected from two extended detention basins serving the M74 motorway in the south-west of Scotland. Additional data were supplied from an experimental lysimeter soil core leaching study. Results show that basin design influences pollutant accumulation and behaviour in the basins. Management and/or control strategies are discussed for reducing the impact of traffic-related pollutants on the aqueous environment

Adherence to a Six-Dose Regimen of Artemether-Lumefantrine for Treatment of Uncomplicated Plasmodium Falciparum Malaria in Uganda.

Measuring baseline levels of adherence and identifying risk factors for non-adherence are important steps before the introduction of new antimalarials. In Mbarara in southwestern Uganda, we assessed adherence to artemether-lumefantrine (Coartem) in its latest World Health Organization blister formulation. Patients with uncomplicated Plasmodium falciparum malaria were prescribed artemether-lumefantrine and received an explanation of how to take the following five doses at home. A tablet count was made and a questionnaire was completed during a home visit. Among 210 analyzable patients, 21 (10.0%) were definitely or probably non-adherent, whereas 189 (90.0%) were probably adherent. Age group was not associated with adherence. Lack of formal education was the only factor associated with non-adherence after controlling for confounders (odds ratio = 3.1, 95% confidence interval [CI] = 1.1-9.7). Mean lumefantrine blood levels were lower among non-adherent (n = 16) (2.76 microg/mL, 95% CI = 1.06-4.45) than among adherent (n = 171) (3.19 microg/mL, 95% CI = 2.84-3.54) patients, but this difference was not statistically significant. The high adherence to artemether-lumefantrine found in our study suggest that this drug is likely to be very effective in Mbarara provided that patients receive clear dosage explanations