A survey of the material and intellectual consequences of trading in undocumented ancient coins : a case study on the North American trade

Ancient coins are among the most widely collected and demanded objects among American collectors of antiquities. A vocal lobby of ancient coin dealers/collectors has arisen to protect the importation of undocumented material into the United States and also seeks to make a distinction between antiquities trafficking and that in ancient coins. Coins are an equally important historical source and are no less important 'antiquities' than a Greek painted vase. I examine the scale of the trade in ancient coins in North America and address some points made by proponents of a continued unfettered ancient coin trade

Formation of Early Water Oceans on Rocky Planets

Terrestrial planets, with silicate mantles and metallic cores, are likely to obtain water and carbon compounds during accretion. Here I examine the conditions that allow early formation of a surface water ocean (simultaneous with cooling to clement surface conditions), and the timeline of degassing the planetary interior into the atmosphere. The greatest fraction of a planet's initial volatile budget is degassed into the atmosphere during the end of magma ocean solidification, leaving only a small fraction of the original volatiles to be released into the atmosphere through later volcanism. Rocky planets that accrete with water in their bulk mantle have two mechanisms for producing an early water ocean: First, if they accrete with at least 1 to 3 mass% of water in their bulk composition, liquid water may be extruded onto the planetary surface at the end of magma ocean solidification. Second, at initial water contents as low as 0.01 mass% or lower, during solidification a massive supercritical fluid and steam atmosphere is produced that collapses into a water ocean upon cooling. The low water contents required for this process indicate that rocky super-Earth exoplanets may be expected to commonly produce water oceans within tens to hundreds of millions of years of their last major accretionary impact, through collapse of their atmosphere.Comment: 8 text pages with 5 figures following; Accepted at Astrophysics and Space Scienc

Ranges of Atmospheric Mass and Composition of Super Earth Exoplanets

Terrestrial-like exoplanets may obtain atmospheres from three primary sources: Capture of nebular gases, degassing during accretion, and degassing from subsequent tectonic activity. Here we model degassing during accretion to estimate the range of atmospheric mass and composition on exoplanets ranging from 1 to 30 Earth masses. We use bulk compositions drawn from primitive and differentiated meteorite compositions. Degassing alone can create a wide range of masses of planetary atmospheres, ranging from less than a percent of the planet's total mass up to ~6 mass% of hydrogen, ~20 mass% of water, and/or ~5 mass% of carbon compounds. Hydrogen-rich atmospheres can be outgassed as a result of oxidizing metallic iron with water, and excess water and carbon can produce atmospheres through simple degassing. As a byproduct of our atmospheric outgassing models we find that modest initial water contents (10 mass% of the planet and above) create planets with deep surface liquid water oceans soon after accretion is complete.Comment: ApJ, in press. 32 pages, 6 figure

Coreless Terrestrial Exoplanets

Differentiation in terrestrial planets is expected to include the formation of a metallic iron core. We predict the existence of terrestrial planets that have differentiated but have no metallic core--planets that are effectively a giant silicate mantle. We discuss two paths to forming a coreless terrestrial planet, whereby the oxidation state during planetary accretion and solidification will determine the size or existence of any metallic core. Under this hypothesis, any metallic iron in the bulk accreting material is oxidized by water, binding the iron in the form of iron oxide into the silicate minerals of the planetary mantle. The existence of such silicate planets has consequences for interpreting the compositions and interior density structures of exoplanets based on their mass and radius measurements.Comment: ApJ, in press. 22 pages, 5 figure

Der Handel mit antiken Münzen in den USA : eingeladener Vortrag ; Frankfurter Numismatische Gesellschaft, 15. April 2009, 18:00 Uhr, Historisches Museum, Frankfurt

Ich werde allerdings noch zur Diskussionskultur in den USA gegen Ende meines Vortrages zu sprechen kommen. Heute möchte ich über meine aktuelle Studie zum Münzhandel in Nordamerika referieren. Obwohl ich mein Hauptaugenmerk auf die Situation in den USA lenke, sind selbstverständlich viele Aspekte auf Europa übertragbar. Zuerst möchte ich den Handel mit Neufunden darlegen. Es ist wichtig darauf hinzuweisen, dass sich viele Händler und Sammler, besonders in den Vereinigten Staaten, darauf berufen, dass der Handel mit antiken Münzen in keinem Zusammenhang mit der Raubgräberei und dem Handel anderer antiker Objekte steht. Danach möchte ich den Umfang des Handels mit Neufunden besprechen und aufzeigen, wie Münzen aus Raubgrabungen über illegale Transaktionen und kriminelle Strukturen von der Ausgrabungsstätte über Schmuggler, Großhändler und spezialisierte Händler schließlich zu den Sammlern gelangen. Ich hoffe, wir stimmen alle dahingehend überein, dass die Probleme eines nicht-regulierten Handels sowohl für die Wissenschaft als auch für die Sammler verheerend sein können. Daher ist es im Interesse beider Seiten diesbezüglich zu kooperieren. Ich bin sehr zuversichtlich, dass das Verhältnis von Sammlern, Händlern und Archäologen in Deutschland ebenso wie im gesamten Europa größere Möglichkeiten für einen ehrlichen Dialoge und positive Änderungen zulassen als in den USA, worauf ich ebenfalls eingehen möchte. ..

Shaping young citizens:high school social studies teachers’ perceptions of patriotism in history education

Abstract. This research seeks to complement theoretical discussion in the field of education on the influence of patriotism in history education. Throughout history, countries have used education to impress upon young citizens loyalty and to promote national values. History education, in particular, has been curated to give these values a creation story. A patriotic national narrative is drawn in which glorified heroes and grand feats solidify the nation’s legitimacy, and inspire its citizens’ unwavering support. While this phenomenon is heavily discussed in educational theory, few qualitative studies have supported it with personal accounts from within schools. For this study, data was collected through semi-structured interviews with high school social studies teachers in North Carolina, to gain insight on their experiences with patriotism in education and the promotion of it in history curriculum. The findings show that patriotism is still an underlying virtue that dictates the historical narrative taught to students. However, it is seen as largely a systemic effort, not a pursuit of teachers. The teachers ultimately pointed to a gap between what is taught in high school history classrooms and current historical research in academia. As such, this study concludes that much of the patriotic undertones in high school history curriculum would be eliminated with the introduction of current academic historiography. Furthermore, the focus of high school history should be on skill development through source analysis, ultimately preparing students to be productive participants in civic life. And in turn, a decreased reliance on teacher’s interpretations and the dramatics of a historical narrative. Finally, the study argues for a more multicultural and global approach to history education for the promotion of cosmopolitan values and global agency. In a time of heightened nationalism around the world, this research helps to locate the role of education and historical interpretation in shaping young citizens

Medallions, Protocontorniates, and Contorniates in the Museum of Art and Archaeology

"The Museum of Art and Archaeology at the University of Missouri possesses in its collection a total of thirty-nine Roman medallions, protocontorniates, and contorniates. One is an imperial coin inserted into a medallic frame; two are medallions proper, struck at official imperial mints; fifteen are "protocontorniates," regular coins later hammered around the edges to create a rim; and twenty-one are contorniates, late Roman "medallions," either cast or struck, that often portray past roman emperors and have a small groove around the edge. The exact purpose and function of protocontorniates and contorniates are unknown, but suggestions have included their use as game counters, or as admission tickets to the circus or theater, or as distributions to the people during new year celebrations. This article surveys the functions of roman medallions, protocontorniates, and contorniates in reference to those in the Museum of Art and Archaeology. A catalogue of medallions, protocontorniates, and contorniates in the collection follows the end of the article."--First paragraph.Includes bibliographical reference

Double window viewing chamber assembly

A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter

Advanced onboard storage concepts for natural gas-fueled automotive vehicles

The evaluation of several advanced concepts for storing natural gas at reduced pressure is presented. The advanced concepts include adsorption on high surface area carbon, adsorption in high porosity zeolite, storage in clathration compounds, and storage by dissolution in liquid solvents. High surface area carbons with high packing density are the best low pressure storage mediums. A simple mathematical model is used to compare adsorption storage on a state of the art carbon with compression storage. The model indicates that a vehicle using adsorption storage of natural gas at 3.6 MPa will have 36 percent of the range, on the EPA city cycle, of a vehicle operating on a compression storage system having the same physical size and a peak storage pressure of 21 MPa. Preliminary experiments and current literature suggest that the storage capacity of state of the art carbons could be improved by as much as 50 percent, and that adsorption systems having a capacity equal to compression storage at 14 MPa are possible without exceeding a maximum pressure of 3.6 MPa