Arc Operads and Arc Algebras

Several topological and homological operads based on families of projectively weighted arcs in bounded surfaces are introduced and studied. The spaces underlying the basic operad are identified with open subsets of a compactification due to Penner of a space closely related to Riemann's moduli space. Algebras over these operads are shown to be Batalin-Vilkovisky algebras, where the entire BV structure is realized simplicially. Furthermore, our basic operad contains the cacti operad up to homotopy, and it similarly acts on the loop space of any topological space. New operad structures on the circle are classified and combined with the basic operad to produce geometrically natural extensions of the algebraic structure of BV algebras, which are also computed.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol7/paper15.abs.htm

"A vision of love and luxury": The commercialization of nineteenth-century American weddings

This article traces the commercialization of weddings in the second half of the nineteenth century. During this period, jewelers and silverware manufacturers recognized the possibilities of the bridal trade. They began to offer special bridal goods and services; they addressed themselves specifically to bridal couples and to those in search of presents for them; and they sought to influence the practices surrounding fashionable weddings in order to expand demand. Fancy bridal gift giving was further justified by a new sentimental attachment to goods among the middle to upper classes, whose fetishistic rhetoric remains a feature of wedding advertising today. © 2004 by The Henry Francis du Pont Winterthur Museum, Inc. All rights reserved

Effect of Spectral Line Shape on Apparent Rotational Temperatures of OH

The effect of spectral line shape on apparent rotational temperatures of OH has been investigated for the P_1 branch, ^2Σ-->^2π transitions, (0, 0) band, by treating the ratio of collision half-width to Doppler half-width as a variable parameter. The results of calculations for emission experiments, using conventional plots, show a large effect of line shape on apparent temperature. In general, the greater the ratio of collision half-width to Doppler half-width, the smaller the distortion of experimental data. The analysis predicts higher apparent rotational temperatures for isothermal systems at reduced pressures than at atmospheric pressures. Although this result is in agreement with experimental observations on flames, it cannot be used as an explanation for the observed data without auxiliary studies proving that distortion of data is of importance in any given case. The two-path method for determining temperatures and emissivities (concentrations) in flames has been extended to spectral lines with combined Doppler- and collision-broadening

Oscillator strengths of the ultraviolet γ bands of NO

N/

Are Baby Boomers Saving Enough for Their Retirement?

Discusses factors that determine the amount of savings baby boomers need for retirement, including income and pre-retirement consumption levels, housing wealth, family type and size, and entitlement to Social Security and defined benefit pension plans

Spectroscopy methods of temperature measurements

N/

On the Validity of Anomalous Population Temperatures in Flames

It should be obvious to anyone reading our recent papers objectively that our "principle thesis" was (a) to examine the origin of the basic relations involved in the customary procedure for the determination of population temperatures in flames, with emphasis on the effect of spectral line shape on the final equations, and (b) to present experimental data on low pressure combustion flames which support the earlier experimental findings of Gaydon and Wolfhard

Determination of Absolute ƒ Values from Relative Intensity Measurements for Spectral Lines with Doppler Contour

The experimental determination of absolute intensities for isolated spectral lines or for entire vibration-rotation bands involves formidable experimental difficulties. For this reason it is highly desirable to consider the use of techniques which permit the determination of absolute f values from relative intensity measurements performed by the use of a low resolution spectrograph. It is the purpose of this note to call attention to a useful experimental procedure for spectral lines with Doppler contour and for optical densities which are sufficiently large to assure a nonlinear dependence of intensity on optical density. The method is a generalization of a two-path experiment proposed for emission studies on flames