Dead cone due to parton virtuality

A general expression for the dead cone of gluons radiated by virtual partons has been derived. The conventional dead cone for massive on-shell quarks and the dead cone for the massless virtual partons have been obtained by using different limits of the general expression. Radiative suppression due to the virtuality of initial parton jets in Heavy-Ion Collisions (HIC) has been discussed. It is observed that the suppression caused by the high virtuality is overwhelmingly large as compared to that on account of conventional dead-cone of heavy quarks. The dead cone due to virtuality may play a crucial role in explaining the observed similar suppression patterns of light and heavy quarks jets in heavy ion collisions at Relativistic Heavy Ion Collider (RHIC)

Lossy gossip and composition of metrics

We study the monoid generated by n-by-n distance matrices under tropical (or min-plus) multiplication. Using the tropical geometry of the orthogonal group, we prove that this monoid is a finite polyhedral fan of dimension n(n-1)/2, and we compute the structure of this fan for n up to 5. The monoid captures gossip among n gossipers over lossy phone lines, and contains the gossip monoid over ordinary phone lines as a submonoid. We prove several new results about this submonoid, as well. In particular, we establish a sharp bound on chains of calls in each of which someone learns something new.Comment: Minor textual edits, final versio

Engine component instrumentation development facility at NASA Lewis Research Center

The Engine Components Instrumentation Development Facility at NASA Lewis is a unique aeronautics facility dedicated to the development of innovative instrumentation for turbine engine component testing. Containing two separate wind tunnels, the facility is capable of simulating many flow conditions found in most turbine engine components. This facility's broad range of capabilities as well as its versatility provide an excellent location for the development of novel testing techniques. These capabilities thus allow a more efficient use of larger and more complex engine component test facilities

Integral cost-benefit analysis of Maglev technology under market imperfections

The aim of this article is to assess a proposed new mode of guided high speed ground transportation, the magnetic levitation rail system (Maglev), and to compare the results of a partial cost-benefit analysis with those of an integral CBA. We deal with an urbanconglomeration as well as a core-periphery Maglev project and also try to explain why the older German Maglev proposal to connect two large, but distant cities (Hamburg and Berlin) was rejected. The empirical outcomes of our study provide policy information on the interregional redistribution of working population and labor demand and whether these projects are worthwhile in terms of national welfare. They also show that the additional economic benefits due to market imperfections vary from –1% to +38% of the direct transport benefits, depending on the type of regions connected and the general condition of the economy. Hence, a uniform ‘additional to direct benefit’ ratio does not exist.

Integral assessment of urban conglomeration versus centre-periphery maglev rail systems under market imperfections

New transport infrastructure has a myriad of short and long run effects. The effects on population and economic activity are most difficult to estimate. This paper introduces three different models to estimate the impacts of new infrastructure on labour supply and demand, and carefully explains how the interaction between the models and their outcomes should be handled. A commuter location model is developed to estimate the impact of enabling longer commuting ranges within the same commuting time on housing migration. A spatial general equilibrium model (RAEM) is developed to estimate the impacts of increased spatial competition on firms and spatial production choices. The commuter location model is then used again to estimate the residential choices of the subsequent labour migration. Finally, an interregional commuter expenditure multiplier matrix is constructed to estimate the employment effects of both housing and labour migration. The methodology developed is applied to four Transrapid (magnetic levitation rail) proposals, each following a different route within the Netherlands. The empirical outcomes show remarkable patterns of effects and differences in effects, which were not expected beforehand but be explained quite well. Thus important new insights into the spatial pattern of indirect effects of new infrastructure in general are provided.

What Matters Most? A Survey of Accomplished Middle-Level Educators\u27 Beliefs and Values about Literacy

Ninety teachers working in award-winning middle schools responded to a survey that explored, quantitatively and qualitatively, how they (1) defined themselves as teachers of literacy, (2) viewed multiliteracies in adolescents\u27 lives, and (3) valued these literacies in the classroom. Mean scores indicated that Basic Literacies (e.g., comprehension, word identification, fluency, writing) were rated more favorably than New Literacies (e.g., media, Internet, critical, out of school). Strong qualitative support existed for literacy instruction in all disciplines, but interpretations varied. The most positive agreement centered on every teacher being a teacher of literacy. Little support existed for developing students\u27 out-of-school literacies in schools. Such findings have strong implications for altering curricular emphases and merging teacher practice with adolescents\u27 needs and interests

Point defect concentrations in metastable Fe-C alloys

Point defect species and concentrations in metastable Fe-C alloys are determined using density functional theory and a constrained free-energy functional. Carbon interstitials dominate unless iron vacancies are in significant excess, whereas excess carbon causes greatly enhances vacancy concentration. Our predictions are amenable to experimental verification; they provide a baseline for rationalizing complex microstructures known in hardened and tempered steels, and by extension other technological materials created by or subjected to extreme environments

Investigation of all Ricci semi-symmetric and all conformally semi-symmetric spacetimes

We find all Ricci semi-symmetric as well as all conformally semi-symmetric spacetimes. Neither of these properties implies the other. We verify that only conformally flat spacetimes can be Ricci semi-symmetric without being conformally semi-symmetric and show that only vacuum spacetimes and spacetimes with just a $\Lambda$-term can be Ricci semi-symmetric without being conformally semi-symmetric.Comment: 4 pages, 1 tabl

The role of M cells and the long QT syndrome in cardiac arrhythmias: simulation studies of reentrant excitations using a detailed electrophysiological model

In this numerical study, we investigate the role of intrinsic heterogeneities of cardiac tissue due to M cells in the generation and maintenance of reentrant excitations using the detailed Luo-Rudy dynamic model. This model has been extended to include a description of the long QT 3 syndrome, and is studied in both one dimension, corresponding to a cable traversing the ventricular wall, and two dimensions, representing a transmural slice. We focus on two possible mechanisms for the generation of reentrant events. We first investigate if early-after-depolarizations occurring in M cells can initiate reentry. We find that, even for large values of the long QT strength, the electrotonic coupling between neighboring cells prevents early-after-depolarizations from creating a reentry. We then study whether M cell domains, with their slow repolarization, can function as wave blocks for premature stimuli. We find that the inclusion of an M cell domain can result in some cases in reentrant excitations and we determine the lifetime of the reentry as a function of the size and geometry of the domain and of the strength of the long QT syndrome