Common Medieval Pigments

This paper discusses the pigments used in medieval manuscripts. Specific types of pigments that are examined are earths, minerals, manufactured, and organics. It also focuses on both destructive and non-destructive methods for identifying medieval pigments

Power operations and coactions in highly commutative homology theories

Power operations in the homology of infinite loop spaces, and H∞ or E∞ ring spectra have a long history in Algebraic Topology. In the case of ordinary mod p homology for a prime p, Dyer-Lashof operations interact with Steenrod operations via the Nishida relations, but for many purposes this leads to complicated calculations once iterated applications of these functions are required. On the other hand, the homology coaction turns out to provide tractable formulae better suited to exploiting multiplicative structure. We show how to derive suitable formulae for the interaction between power operations and homology coactions in a wide class of examples; our approach makes crucial use of modern frameworks for spectra with well behaved smash products. In the case of mod <i>p</i> homology, our formulae extend those of Bisson & Joyal to odd primes. We also show how to exploit our results in sample calculations, and produce some apparently new formulae for the Dyer-Lashof action on the dual Steenrod algebra

Approximate solutions for the single soliton in a Skyrmion-type model with a dilaton scalar field

We consider the analytical properties of the single-soliton solution in a Skyrmion-type Lagrangian that incorporates the scaling properties of quantum chromodynamics (QCD) through the coupling of the chiral field to a scalar field interpreted as a bound state of gluons. The model was proposed in previous works to describe the Goldstone pions in a dense medium, being also useful for studying the properties of nuclear matter and the in-medium properties of mesons and nucleons. Guided by an asymptotic analysis of the Euler-Lagrange equations, we propose approximate analytical representations for the single soliton solution in terms of rational approximants exponentially localized. Following the Pad\'e method, we construct a sequence of approximants from the exact power series solutions near the origin. We find that the convergence of the approximate representations to the numerical solutions is considerably improved by taking the expansion coefficients as free parameters and then minimizing the mass of the Skyrmion using our ans\"atze for the fields. We also perform an analysis of convergence by computation of physical quantities showing that the proposed analytical representations are very useful useful for phenomenological calculations.Comment: 13 pages, 3 eps figures, version to be published in Phys.Rev.

A split finite element algorithm for the compressible Navier-Stokes equations

An accurate and efficient numerical solution algorithm is established for solution of the high Reynolds number limit of the Navier-Stokes equations governing the multidimensional flow of a compressible essentially inviscid fluid. Finite element interpolation theory is used within a dissipative formulation established using Galerkin criteria within the Method of Weighted Residuals. An implicit iterative solution algorithm is developed, employing tensor product bases within a fractional steps integration procedure, that significantly enhances solution economy concurrent with sharply reduced computer hardware demands. The algorithm is evaluated for resolution of steep field gradients and coarse grid accuracy using both linear and quadratic tensor product interpolation bases. Numerical solutions for linear and nonlinear, one, two and three dimensional examples confirm and extend the linearized theoretical analyses, and results are compared to competitive finite difference derived algorithms

CONSUMER PREFERENCES FOR FOOD SAFETY ATTRIBUTES IN FRESH APPLES: MARKET SEGMENTS, CONSUMER CHARACTERISTICS, AND MARKETING OPPORTUNITIES

Past research has yielded conflicting results on consumer valuation of food safety characteristics. In this study, conjoint analysis is used to evaluate consumer responses to hypothetical apple products in a nationwide survey. Product characteristics include price, quality, pesticide use levels and the corresponding cancer risk, and type of government inspection. Consumers expressed a broad preference for reduced pesticide usage. Four market segments were identified corresponding to consumers: (a) who had a strong preference for food safety, (b) who exhibited a more balanced desire for all product characteristics, (c) who were extremely price sensitive, and (d) who had a strong preference for product quality. Results suggest that consumers in these segments differ based on demographic and psychographic characteristics. This information should prove useful to produce marketers in marketing produce that better meets consumers'Â’ needs.Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

FOOD SAFETY AND FEAR: FACTORS AFFECTING CONSUMER RESPONSE TO FOOD SAFETY RISK

The objective of this research was to explore the factors that affect consumers' responses to low probability food safety risks. A survey of two thousand consumers was conducted in mid-2003, yielding a response rate of 32.0%. The analysis indicated a family-oriented response to food safety risks. Primary meal planners, women, and members of households with young children were the most likely to have an extreme risk avoidance response.Food Consumption/Nutrition/Food Safety,

Analysis of boundary conditions for SSME subsonic internal viscous flow analysis

A study was completed of mathematically proper boundary conditions for unique numerical solution of internal, viscous, subsonic flows in the space shuttle main engine. The study has concentrated on well posed considerations, with emphasis on computational efficiency and numerically stable boundary condition statements. The method of implementing the established boundary conditions is applicable to a wide variety of finite difference and finite element codes, as demonstrated