Generalized Communicating P Systems Working in Fair Sequential Model

In this article we consider a new derivation mode for generalized communicating P systems (GCPS) corresponding to the functioning of population protocols (PP) and based on the sequential derivation mode and a fairness condition. We show that PP can be seen as a particular variant of GCPS. We also consider a particular stochastic evolution satisfying the fairness condition and obtain that it corresponds to the run of a Gillespie's SSA. This permits to further describe the dynamics of GCPS by a system of ODEs when the population size goes to the infinity.Comment: Presented at MeCBIC 201

Effects of aluminum additions to gas atomized reaction synthesis produced oxide dispersion strengthened alloys

The production of an aluminum containing ferritic oxide dispersion strengthened (ODS) alloy was investigated. The production method used in this study was gas atomization reaction synthesis (GARS). GARS was chosen over the previously commercial method of mechanical alloying (MA) process due to complications from this process. The alloy compositions was determined from three main components; corrosion resistance, dispersoid formation, and additional elements. A combination of Cr and Al were necessary in order to create a protective oxide in the steam atmosphere that the boiler tubing in the next generation of coal-fired power plants would be exposed to. Hf and Y were chosen as dispersoid forming elements due to their increased thermal stability and potential to avoid decreased strength caused by additions of Al to traditional ODS materials. W was used as an additive due to benefits as a strengthener as well as its benefits for creep rupture time. The final composition chosen for the alloy was Fe-16Cr-12Al-0.9W-0.25Hf-0.2Y at%. The aforementioned alloy, GA-1-198, was created through gas atomization with atomization gas of Ar-300ppm O2. The actual composition created was found to be Fe-15Cr-12.3Al-0.9W-0.24Hf-0.19Y at%. An additional alloy that was nominally the same without the inclusion of aluminum was created as a comparison for the effects on mechanical and corrosion properties. The actual composition of the comparison alloy, GA-1-204, was Fe-16Cr-0Al-0.9W-0.25Hf-0.24Y at%. An investigation on the processing parameters for these alloys was conducted on the GA-1-198 alloy. In order to predict the necessary amount of time for heat treatment, a diffusion study was used to find the diffusion rate of oxygen in cast alloys with similar composition. The diffusion rate was found to be similar to that of other GARS compositions that have been created without the inclusion of aluminum. The effect of heat treatment time was investigated with temperatures of 950°C, 1000°C, 1100°C, and 1200°C. A large precipitate phase, FeHf2 ht, was found in the 950°C and 1000°C samples through SEM. This was confirmed through XRD analysis where it was found that the 1100°C sample may have had clusters. These clusters could act as a location for the origination of cracks during future rolling operations. For this reason, an attempt to look at the hold time and ramp rates on the formation this phase. It was found that a 1200°C hold for 5 hours was able to homogenize the sample to prevent precipitation of the FeHf2 ht phase during a subsequent hold at 1000°C, the rolling temperature used in this study. For this reason a heat treatment at 1200°C for 5 hours was used in both alloys. Both alloys were rolled to 70% reduction in thickness and evaluated through microhardness, tensile testing, and corrosion testing. Microhardness showed high strength for the aluminum containing GA-1-198 and significantly more isotropic properties than mechanically alloyed ODS materials. Tensile testing showed GA-1-198 strength between MA956 and PM2000 for temperatures below 600°C and slightly lower strengths than MA856 at 800°C. GA-1-204 was not protective in either atmosphere; air at 1200°C and air with 10 vol% H2O at 1100°C. GA-1-198 showed increased mass gains due to sub-optimal oxygen content in the alloy. GA-1-198 had spallation in the air at 1200°C atmosphere, but remained protective up to 1000 hr in the water containing atmosphere

The Conversational Dynamic in American Public Life

A confluence of factors has sparked a sustained, public preoccupation with conversation. Brewing since the fifteenth century and overtly public since the middle of the nineteenth century, the explosion of public models of conversation that emerged in the European and American rhetorical traditions is significant—without precedent—in the history of rhetoric. This interest in conversation is so pronounced as to penetrate not just public speaking practices, but subtler interpretations of law, philosophy, commerce, and government. I identify this as the conversational turn. The extent to which this saturation was truly conversational is the subject of much debate. However, the contours of this debate are little understood. This is both a historical and theoretical problem. While the art of face-to-face conversation is said to be either irrevocably in decline or in desperate need of reclaiming, practically every modern communication invention has conspired to make the rhetorical metaphor and structure of conversation not just possible in public life, but desired and expected. In an effort to understand how and why the public conversational dynamic rose to prominence in the way that it did, this study brings together underlying social and political dynamics that animate the conversational turn, particularly as they developed in the United States. By doing so, this project recasts the dominant narrative about the public shift away from oratory and toward conversation in contemporary, democratic societies

Political Perfectionism and Aesthetic Experience

Many people share the belief that the state can lend support to the arts and the natural environment for their cultural and aesthetic qualities. However, the question remains open as to what justifies this support. This question hinges on whether the state must be neutral in reference to judgment of values. The political anti-perfectionist positions of Rawls and Dworkin are inadequate to justify this kind of state support because the funding of art necessarily involves a judgment of value in two ways. First, the fact that the state funds any art requires that, in general, art is valuable. Second, determining which art to fund, since presumably the state cannot fund all art, requires making a value judgment about which art is worth funding. Thus, in order to justify art\u27s funding, a theory of the state must allow judgments of value. Even if we have a theory of the state that allows the state to act on judgments of value, this alone does not prove that art is the kind of thing that the state should support. Why should the state care specifically about art? I argue that aesthetic experience is the most fundamental purpose of art and that aesthetic experience is a basic human good. The state exists for the common good of its citizens. Thus it has a vested interest in things that lead to the citizens\u27 well-being, like aesthetic experience. And this is what justifies the state in supporting the arts. To illustrate how this works on a practical level, I show how art is funded in the United States, while also pointing out ways that it could be funded differently depending on circumstances