11,361 research outputs found
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
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
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
Medicare Premiums and Social Security's Cost-of-Living Adjustments
Outlines how Medicare Part B and Part D premium hikes will cancel out the cost of living increases in Social Security benefits, severely affecting the lowest-income beneficiaries. Examines premium design characteristics and trends in premium growth
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