Epistemic Injustice and the Preservation of Ignorance

Ignorance is a neglected issue in philosophy. This is surprising for, contrary to what one might expect, it is not clear what ignorance is

Calculations of hot gas ingestion for a STOVL aircraft model

Hot gas ingestion problems for Short Take-Off, Vertical Landing (STOVL) aircraft are typically approached with empirical methods and experience. In this study, the hot gas environment around a STOVL aircraft was modeled as multiple jets in crossflow with inlet suction. The flow field was calculated with a Navier-Stokes, Reynolds-averaged, turbulent, 3D computational fluid dynamics code using a multigrid technique. A simple model of a STOVL aircraft with four choked jets at 1000 K was studied at various heights, headwind speeds, and thrust splay angles in a modest parametric study. Scientific visualization of the computed flow field shows a pair of vortices in front of the inlet. This and other qualitative aspects of the flow field agree well with experimental data

Parallel ALLSPD-3D: Speeding Up Combustor Analysis Via Parallel Processing

The ALLSPD-3D Computational Fluid Dynamics code for reacting flow simulation was run on a set of benchmark test cases to determine its parallel efficiency. These test cases included non-reacting and reacting flow simulations with varying numbers of processors. Also, the tests explored the effects of scaling the simulation with the number of processors in addition to distributing a constant size problem over an increasing number of processors. The test cases were run on a cluster of IBM RS/6000 Model 590 workstations with ethernet and ATM networking plus a shared memory SGI Power Challenge L workstation. The results indicate that the network capabilities significantly influence the parallel efficiency, i.e., a shared memory machine is fastest and ATM networking provides acceptable performance. The limitations of ethernet greatly hamper the rapid calculation of flows using ALLSPD-3D

Interplay between function and structure in complex networks

We show that abrupt structural transitions can arise in functionally optimal networks, driven by small changes in the level of transport congestion. Our results offer an explanation as to why so many diverse species of network structure arise in Nature (e.g. fungal systems) under essentially the same environmental conditions. Our findings are based on an exactly solvable model system which mimics a variety of biological and social networks. We then extend our analysis by introducing a novel renormalization scheme involving cost motifs, to describe analytically the average shortest path across multiple-ring-and-hub networks. As a consequence, we uncover a 'skin effect' whereby the structure of the inner multi-ring core can cease to play any role in terms of determining the average shortest path across the network.Comment: Expanded version of physics/0508228 with additional new result

Fatal anaphylactic sting reaction in a patient with mastocytosis

We report on a 33-year-old female patient with indolent systemic mastocytosis and urticaria pigmentosa who died of an anaphylactic reaction after a yellow jacket sting. As she had no history of previous anaphylactic sting reaction, there was no testing performed in order to detect hymenoptera venom sensitization. But even if a sensitization had been diagnosed, no venom immunotherapy (VIT) would have been recommended. It is almost certain that VIT would have saved her life and it is most likely that VIT is indicated in some patients with mastocytosis with no history of anaphylactic sting reaction. However, no criteria have been established in order to allow a selection of mastocytosis patients eligible for such a `prophylactic' VIT. Copyright (C) 2008 S. Karger AG, Basel

Analysis of Ice Plains of Filchner/Ronne Ice Shelf Using ICESat Data

We use repeat-track laser altimeter data from the Ice, Cloud, and land Elevation Satellite (ICESat) to map the grounding zone of Filchner/Ronne Ice Shelf (FRIS), Antarctica. Repeated passes of ICESat reveal ice flexure in the grounding zone occurs as the ice shelf responds to ocean height changes due primarily to tides. In the course of our mapping, we have confirmed or identified three major "ice plains", regions of low surface slope near the GZ where the ice is close to hydrostatic equilibrium: one on Institute Ice Stream, another to its east, and another west of Foundation Ice Stream. The vertical information from repeated ICESat tracks enables us to study the topography and flexure characteristics across these three ice plains, and we use this to develop a classification scheme for ice plains based on their surface topography and their state of flotation. We show that one of these ice plains indicates changes in lateral extent on short time-scales, depending on the state of the ocean tide. Understanding the location and nature of ice plains is important for ice sheet modeling, since they add uncertainty to the absolute boundary between floating and grounded ice

Ambivalence about forgiveness

Our ideas about forgiveness seem to oscillate between idealization and scepticism. How should we make sense of this apparent conflict? This paper argues that we should learn something from each, seeing these views as representing opposing moments in a perennial and well-grounded moral ambivalence towards forgiveness. Once we are correctly positioned, we shall see an aspect of forgiveness that recommends precisely this ambivalence. For what will come into view will be certain key psychological mechanisms of moral-epistemic influence – other-addressed and self-addressed mechanisms of moral social construction – that enable forgiveness to function well when it is well-functioning, but which are also intrinsically prone to deterioration into one or another form of bad faith. Thus forgiveness is revealed as necessarily containing seeds of its own corruption, showing ambivalence to be a generically appropriate attitude. Moreover, it is emphasized that where forgiver and forgiven are relating to one another in the context of asymmetries of social power, the practice of forgiveness is likely to be further compromised, notably increasing the risk of negative influence on the moral-epistemic states of either the forgiver or the forgiven, or both

Steel Bridge Protection Policy: Main Report

The study identifies various painting systems that are successfully used in Indiana’s surrounding states and other industries. The identified systems are further screened and evaluated. After prudently comparing INDOT’s inorganic zinc / vinyl system with the waterborne acrylic system, the moisture cure urethane coating system, and the 3-coat system of zinc-epoxy-urethane, the results show that the new 3-coat system fulfills INDOT’s needs with the most benefits. Therefore, the 3-coat system is recommended to replace INDOT present inorganic zinc / vinyl system. To deal with the problems facing the lead-based paint, a comparison between full-removal and over-coating alternatives is made. Results show that over-coating might provide a good protection for less than half the cost of full-removal; however it delays the lead full-removal process and does not completely solve the environmental problem. The metalization of steel bridges is seemingly a potential protection policy. After reviewing standards and specifications on metalization, it is shown that metalization jobs require a higher degree of control. It suits on-shop practices, however, the initial cost is considerably high. This study also describes a life cycle cost analysis that was done to determine an optimal painting system for INDOT. Herein, a deterministic method of economic analysis and a stochastic method of Markov chains process are used. The analysis not only reconfirms that the 3-coat system is the comparatively better painting system, but also generates an optimal painting maintenance plan for INDOT. To assure the quality of paint material and workmanship after substantial completion of the painting contract, the development of legally binding and dependable warranty clauses is initiated in this study. The developed painting warranty clauses were primarily derived from the painting warranty clauses used by IDOT, MDOT, and INDOT’s pavement warranty clauses. A comparative study was conducted on eleven essential categories. Among them, it was found that the warranty period, the definition of “defect”, and the amount of the warranty bond all need further evaluation

Steel Bridge Protection Policy: Life Cycle Cost Analysis and Maintenance Plan

The study identifies various painting systems that are successfully used in Indiana\u27s surrounding states and other industries. the identified systems are further screened and evaluated. After prudently comparing INDOT\u27s inorgainc zinc/vinyl system with the waterborne acrylic system, the moisture cure urethane coating system and the 3-coat system of zinc-epoxy-urethane, the sresults show that thte new 3-coat system fulfills INDOT\u27s needs with the most benefits. Therefore, the 3-coat system is recommended to replace INDOT present inorgaic zinc/vinyl system. To deal with the problems facing the lead-based paint, a comparison between full-removal and over-coating alternatives is made. Results show that over-coating might provide a good protection for less than half the cost of full-removal; however it delays the lead full-removal process and does not completely solve the environmental problem. The metalization of steel bridges is seemingly a potential protection policy. After reviewing standards and specifications on metalizzation, it is shown that metalizzation jobs require a higher degree of control. It suits on-shop practices, however, the initial cost is considerably high. This study also describes a life cycle cost analysis that was done to determine an optimal painting system for INDOT. Herein, a deterministic method of economic analysis and a stochastic method of Markov chains process are used. The analysis not only reconfirms that the 3-coat system is the comparatively better painting system, but also generates an optimal painting maintenance plan for INDOT. To assure the quality of paint materials and workmanship after substania