QCD Effects in the Decays of TeV Black Holes

In models with ``large'' and/or warped extra dimensions, the higher-dimensional Planck scale may be as low as a TeV. In that case black holes with masses of a few TeV are expected to be produced copiously in multi-TeV collisions, in particular at the LHC. These black holes decay through Hawking radiation into typically O(20) Standard Model particles. Most of these particles would be strongly interacting. Naively this would lead to a final state containing 10 or so hadronic jets. However, it has been argued that the density of strongly interacting particles would be so large that they thermalize, forming a ``chromosphere'' rather than well-defined jets. In order to investigate this, we perform a QCD simulation which includes parton-parton scattering in addition to parton showering. We find the effects of parton scattering to remain small for all cases we studied, leading to the conclusion that the decays of black holes with masses within the reach of the LHC will not lead to the formation of chromospheres.Comment: LaTeX with equation.sty (included), 26 pages, 4 figures. Added a few references and one footnot

Numerical simulations of the possible origin of the two sub-parsec scale and counter-rotating stellar disks around SgrA*

We present a high resolution simulation of an idealized model to explain the origin of the two young, counter-rotating, sub-parsec scale stellar disks around the supermassive black hole SgrA* at the Center of the Milky Way. In our model, the collision of a single molecular cloud with a circum-nuclear gas disk (similar to the one observed presently) leads to multiple streams of gas flowing towards the black hole and creating accretion disks with angular momentum depending on the ratio of cloud and circum-nuclear disk material. The infalling gas creates two inclined, counter-rotating sub-parsec scale accretion disks around the supermassive black hole with the first disk forming roughly 1 Myr earlier, allowing it to fragment into stars and get dispersed before the second, counter-rotating disk forms. Fragmentation of the second disk would lead to the two inclined, counter-rotating stellar disks which are observed at the Galactic Center. A similar event might be happening again right now at the Milky Way Galactic Center. Our model predicts that the collision event generates spiral-like filaments of gas, feeding the Galactic Center prior to disk formation with a geometry and inflow pattern that is in agreement with the structure of the so called mini-spiral that has been detected in the Galactic Center.Comment: 14 pages, 12 figures, submitted to Ap

Empirical Methods for Modeling Landscape Change, Ecosystem Services, and Biodiversity

Resource /Energy Economics and Policy,

LAND-USE CHANGE AND CARBON SEQUESTRATION IN THE FORESTS OF OHIO, INDIANA, AND ILLINOIS: SENSITIVITY TO POPULATION AND MODEL CHOICE

This study develops a model of land use change in the Midwestern States of Ohio, Indiana, and Illinois. Given the emergence of spatial econometrics, three models are compared to assess the sensitivity of the estimates to alternative assumptions about the distribution of their errors. Projections of future land use change are then developed, and the results are compared across different assumptions about population growth and models. We then estimate carbon sequestration potential in the region and compare the costs of different programs across the population assumptions and the alternative models. Different assumptions about population growth and error terms do not appear to affect the carbon sequestration cost estimates.Environmental Economics and Policy, Land Economics/Use,

Simulating the impact of the Smith Cloud

We investigate the future evolution of the Smith Cloud by performing hydrodynamical simulations of the cloud impact onto the gaseous Milky Way Galactic disk. We assume a local origin for the cloud and thus do not include a dark matter component to stabilize it. Our main focus is the cloud's influence on the local and global star formation rate (SFR) of the Galaxy and whether or not it leads to an observable event in the far future. Our model assumes two extremes for the mass of the Smith Cloud, an upper mass limit of 10$^7$ M$_{\odot}$ and a lower mass limit of 10$^6$ M$_{\odot}$, compared to the observational value of a few 10$^6$ M$_{\odot}$. In addition, we also make the conservative assumption that the entirety of the cloud mass of the extended Smith Cloud is concentrated within the tip of the cloud. We find that the impact of the low-mass cloud produces no noticeable change in neither the global SFR nor the local SFR at the cloud impact site within the galactic disk. For the high-mass cloud we find a short-term (roughly 5 Myr) increase of the global SFR of up to 1 M$_{\odot}$ yr$^{-1}$, which nearly doubles the normal Milky Way SFR. This highly localized starburst should be observable.Comment: 14 pages, 5 figure

The Influence of Cultural and Social Capital on Post-Baccalaureate Students’ Decision to Enter and Complete Graduate School

Despite increased diversity noted in undergraduate education in recent years (Antonio, 2003), students from non-majority groups continue to be underrepresented in graduate school. Many research studies (Perna, 2000, 2004; Perna & Titus, 2005; Rowan-Kenyon, 2007; Walpole, 2003, 2007b) have used measures of cultural and social capital to increase the explanatory power of the traditional econometric framework in college choice models, but have not used these sociological variables as a primary focus. The purpose of this correlational study was to explore the influence of cultural capital and social capital on the decision of bachelor’s degree completers to enter graduate school and ultimately to degree achievement. The study is an extension of Perna’s 2004 work, which examined similar relationships of cultural and social capital variables via use of the Baccalaureate & Beyond: 93/97 study. Based on Walpole’s findings (2003), variables related to socioeconomic status (SES) were also included in my analysis. The data used to answer the research questions were collected as part of a longitudinal study, the Baccalaureate & Beyond: 93/03. Participants in the Baccalaureate & Beyond: 93/03 study were students in the U.S. who earned a bachelor’s degree during the 1992-1993 academic year, representing a population of 1.2 million individuals (Choy, Bradburn, & Carroll, 2008). My findings revealed that measures of cultural and social capital have a significant influence on graduate school enrollment and degree completion. Among low SES students (as designated by family income) cultural and social capital variables substantially increased the likelihood of graduate degree attainment

An Investigation of Certain Aspects of Human Figure Drawings as a Measure of Sociability of the Person

For many years considerable interest has been shown in spontaneous drawing productions as related to personality study. However, little has been accomplished toward validating this measure as useful in the clinic, and even less has been done to demonstrate its usefulness with normal individuals. This study, therefore, is an attempt to determine whether or not certain aspects i.e., the manner in which the arms and hands are represented, in drawings of the human figure will objectively differentiate between social and non-social, normal individuals

IMPACTS OF INCORPORATING LAND EXCHANGES BETWEEN FORESTRY AND AGRICULTURE IN SECTOR MODELS

The forest and agriculture sectors are linked by having a portion of their land bases suitable for use in either sector. A substantial part of the southern land base is suitable for either forestry or agriculture use, with most of forestation on U.S. agriculture land in the South. We examine how land exchanges between forestry and agriculture are influenced by specific federal conservation and farm support policies, including changes in the Conservation Reserve Program. Reallocation of land is a significant part of the sectors' responses to the policies, along with intensification of timber management on existing southern forests.Agriculture, Conservation, Forest sector, Land use, Projections, Land Economics/Use,

Simple derivation of the frequency dependent complex heat capacity

This paper gives a simple derivation of the well-known expression of the frequency dependent complex heat capacity in modulated temperature experiments. It aims at clarified again that the generalized calorimetric susceptibility is only due to the non-equilibrium behaviour occurring in the vicinity of thermodynamic equilibrium of slow internal degrees of freedom of a sample when the temperature oscillates at a well determined frequency