Complete set of electromagnetic corrections to the nucleon mass in the Nambu-Jona-Lasinio model

We show how to derive the complete set of electromagnetic corrections to the Nambu-Jona-Lasinio (NJL) model of the nucleon. Our results enable an accurate estimate of the electromagnetic contribution to the neutron-proton mass difference within this model. At the same time, our procedure demonstrates the way to calculate the complete set of meson corrections to the NJL model that maintains chiral symmetry.Comment: Contribution to Proceedings, KEK-Tanashi International Symposium on Physics of Hadrons and Nuclei, 14-17 December 1998, Tokyo, Japan, to be published in Nuclear Physics A. 5 pages, revtex, epsf, 2 postscript figures. Minor addition to last figure, typos correcte

Homogeneous comparison of planet candidates imaged directly until 2008

We present a compilation of the planet candidates currently known from direct imaging. We have gathered available data from the literature and derive the luminosity of all candidates in a homogeneous way using a bolometric correction, the distances and the K band magnitudes of the objects. In a final step we find the masses of the candidates from a comparison of the luminosity or, if not available, an absolute brightness and several well known hot-start evolutionary models.Comment: 4 pages, 1 figure, Proceedings of the 2nd Subaru International Conference on Exoplanets and Disks: Their Formation and Diversity, Keauhou - Hawaii - USA, 9-12 March 2009; 2nd version: Several typos correcte

Electron Depletion Due to Bias of a T-Shaped Field-Effect Transistor

A T-shaped field-effect transistor, made out of a pair of two-dimensional electron gases, is modeled and studied. A simple numerical model is developed to study the electron distribution vs. applied gate voltage for different gate lengths. The model is then improved to account for depletion and the width of the two-dimensional electron gases. The results are then compared to the experimental ones and to some approximate analytical calculations and are found to be in good agreement with them.Comment: 16 pages, LaTex (RevTex), 8 fig

Addressing decision making for remanufacturing operations and design-for-remanufacture

Remanufacturing is a process of returning a used product to at least original equipment manufacturer original performance specification from the customers' perspective and giving the resultant product a warranty that is at least equal to that of a newly manufactured equivalent. This paper explains the need to combine ecological concerns and economic growth and the significance of remanufacturing in this. Using the experience of an international aero-engine manufacturer it discusses the impact of the need for sustainable manufacturing on organisational business models. It explains some key decision-making issues that hinder remanufacturing and suggests effective solutions. It presents a peer-validated, high-level design guideline to assist decision-making in design in order to support remanufacturing. The design guide was developed in the UK through the analysis of selections of products during case studies and workshops involving remanufacturing and conventional manufacturing practitioners as well as academics. It is one of the initial stages in the development of a robust design for remanufacture guideline

A posteriori agreement as a quality measure for readability prediction systems

All readability research is ultimately concerned with the research question whether it is possible for a prediction system to automatically determine the level of readability of an unseen text. A significant problem for such a system is that readability might depend in part on the reader. If different readers assess the readability of texts in fundamentally different ways, there is insufficient a priori agreement to justify the correctness of a readability prediction system based on the texts assessed by those readers. We built a data set of readability assessments by expert readers. We clustered the experts into groups with greater a priori agreement and then measured for each group whether classifiers trained only on data from this group exhibited a classification bias. As this was found to be the case, the classification mechanism cannot be unproblematically generalized to a different user group

Magnitude of Hazards Associated with the Rail Transport of Crude Oil and LPG

PresentationOver the past several years, the volume of crude oil being transported by rail has dramatically increased. With this increase, the number of train accidents involving crude oil rail cars has also increased. A common perception of the public is that the risk associated with “crude-by-rail” has increased. This may be true due to an increase in rail car shipments but has the magnitude of hazards associated with crude by rail transport changed? Arguments have been made that the compositions of specific crudes make them more hazardous than conventional crude. Is there a basis for this claim? As the volume of crude transported by rail has increased, so has the volume of liquefied petroleum gases (LPGs) transported by rail, albeit with different types of rail cars than those used for crude oil. This paper will investigate the magnitude of hazards associated with rail transport of a range of crude oils and LPGs. The release mechanisms will be affected by the type of rail car employed (DOT-112, DOT-111, and the modified DOT-111 called the 1232) and the fluid condition upon release. The result of the overall analysis will be a side-by-side comparison of hazard magnitude as a function of the transported fluid and the rail car employed

What API RP 752 Does Not Tell You – But People Will Ask

PresentationOver the past several years, Quest Consultants Inc. has conducted building siting studies per API RP 752 for a range of facilities in the United States and abroad. This paper summarizes several of the issues encountered when applying the guidance provided by API RP 752. While the API recommended practices may not address the full range of hazards a building occupant could experience, other codes such as 29 CFR 1910 do require their evaluation under the “general duty clause” and the Process Safety Management (PSM) program. What will be outlined in this paper are the “holes” in the API RP 752 guidance as well as possible approaches to address these missing elements. Questions that are simple to ask (e.g., What happens to your siting study if a new facility moves in just past your fence line?) may be difficult or impossible to answer. However, if an impact is realized, do you have to move your building due to your new neighbor’s operation? This is only one example of a host of scenarios that will be addressed in this paper

Quantitative Risk Calculations for a U.S. DOT Natural Gas Pipeline Using Population Classifications

PresentationOver the past several years, Quest Consultants Inc. has conducted quantitative risk analysis (QRA) and risk assessment studies for a range of pipelines in the United States and abroad. In most instances, the risk acceptance or tolerability criteria are defined by the individual risk (IR) to a person; often this risk is presented as location specific individual risk (LSIR). The LSIR is a measure of the risk to a person who is continuously at a specific location. In recent years, there has been increasing dependence on the use of societal risk acceptance or tolerability criteria, including the risk associated with pipelines. Pipelines are often described as linear sources of risk, like highways and rail lines. The risk analysis methodology used to calculate the risk associated with fixed facilities (e.g., refineries and chemical plants) cannot be directly applied to linear risk sources. This paper presents a risk calculation methodology that can be applied to linear risk sources, like natural gas pipelines, and compares the societal risk indices for U.S. DOT pipeline classes

Black hole tidal problem in the Fermi normal coordinates

We derive a tidal potential for a self-gravitating fluid star orbiting Kerr black hole along a timelike geodesic extending previous works by Fishbone and Marck. In this paper, the tidal potential is calculated up to the third and fourth-order terms in $R/r$, where $R$ is the stellar radius and $r$ the orbital separation, in the Fermi-normal coordinate system following the framework developed by Manasse and Misner. The new formulation is applied for determining the tidal disruption limit (Roche limit) of corotating Newtonian stars in circular orbits moving on the equatorial plane of Kerr black holes. It is demonstrated that the third and fourth-order terms quantitatively play an important role in the Roche limit for close orbits with R/r \agt 0.1. It is also indicated that the Roche limit of neutron stars orbiting a stellar-mass black hole near the innermost stable circular orbit may depend sensitively on the equation of state of the neutron star.Comment: Correct typo