Thickness of the strangelet-crystal crust of a strange star

It has recently been pointed out that if the surface tension of quark matter is low enough, the surface of a strange star will be a crust consisting of a crystal of charged strangelets in a neutralizing background of electrons. This affects the behavior of the surface, and must be taken into account in efforts to observationally rule out strange stars. We calculate the thickness of this ``mixed phase'' crust, taking into account the effects of surface tension and Debye screening of electric charge. Our calculation uses a generic parametrization of the equation of state of quark matter. For a reasonable range of quark matter equations of state, and surface tension of order a few MeV/fm^2, we find that the preferred crystal structure always involves spherical strangelets, not rods or slabs of quark matter. We find that for a star of radius 10 km and mass 1.5 Msolar, the strangelet-crystal crust can be from zero to hundreds of meters thick, the thickness being greater when the strange quark is heavier, and the surface tension is smaller. For smaller quark stars the crust will be even thicker.Comment: 10 pages, LaTe

Mount Pawtuckaway Ring-Dike Complex

Geology of the coastal lowlands, Boston to Kennebunk, Maine: The 76th annual meeting New England Intercollegiate Geological Conference, Danvers, Massachusetts, October 12-14, 1984: Trip B-

Geochronology of the Arkanas Alkaline Province, Southeastern United States

The Arkansas alkaline province (AAP) consists of intrusive bodies ranging in lithology from carbonatite and lamproite through nepheline syenite. Apatite and titanite fission-track ages fall into two groups-101-94 Ma and ∼88 Ma. New Ar/Ar ages and those reported in the literature define a third age group of ∼106 Ma. Apatite and titanite fissiontrack ages are concordant, indicating rapid cooling due to the emplacement of these intrusions at high levels during a time of regional uplift. There is a relationship between age and petrology: (1) lamproites are emplaced at ∼106 Ma, (2) carbonatites and associated silica-undersaturated rocks are emplaced between 101 and 94 Ma, and (3) large nepheline syenite bodies are emplaced at ∼88 Ma. Chemical and isotopic data support the inference that the lamproites are derived from subcontinental lithosphere, while the other sequences are derived from the asthenosphere. The ages for the AAP and other conflicting information do not support the hypothesis that the AAP was formed by the passage of the North American plate over the Bermuda hotspot. A more likely explanation is that the magmatism was related to extension and reactivation of faults associated with the Mississippi graben

Six Unpublished Nabataean Drachms: Filling some Gaps

Sechs bisher unbekannte nabatäische Drachmen aus der Regierungszeit von Aretas IV., Malichus II. und Rabbel II. werden in diesem Artikel vorgestellt. Die jeweils datierten Münzen schließen einige der zeitlichen Lücken in der Silberprägung dieser Zeit. Einblick in die Silberknappheit im nabatäischen Königreichs während dieser Periode wird gegeben. Für bislang (noch) nicht nachgewiesene datierte Drachmen lassen sich Vermutungen aufstellen.Six hitherto unknown dated Nabataean drachms from the reigns of Aretas IV, Malichus II, and Rabbel II are described in this article. The existence of these coins tightens some of the temporal gaps in the dated silver coinage of this period. Insight into the scarcity of silver within the Nabataean kingdom during this period is demonstrated. Suggestions as to yet undiscovered dated drachms are also made

The Dutchman Vol. 7, No. 2

● Basketry, a Pennsylvania Dutch Art ● Decorative Elements in the Domestic Architecture of Eastern Pennsylvania ● Literature on Log Architecture ● Pennsylvania Tour of Europe ● Matters Genealogical ● Feeding Them by the Hundred ● The Zehn-uhr Schtickhttps://digitalcommons.ursinus.edu/dutchmanmag/1005/thumbnail.jp

Clock and Power Distribution Networks for 3-D ICs

Global interconnect design for threedimensional integrated circuits is a crucial task. Despitethe importance of this task, limited results related to global issues have been presented. Challenges in reliably distributing power, ground, and the clock signal within a multi-plane integrated system are discussed in this paper. The design of two 3-D test circuits addressing these issues is described. Candidate 3-D topologies for both power and clock distribution networks are also presented. Design implications due to the different design approaches are discussed. Experimental and simulation results of the 3-D clock and power distribution architectures, respectively, are provided. Both of the test circuits are fabricated by the 3-D fabrication process developed at MIT Lincoln Laboratories (MITLL). The design of the clock and power distribution networks is discusse

The Pennsylvania Dutchman Vol. 8, No. 3

● The Dutch Touch in Iron ● The Pennsylvania Dutch Village ● Five June Days ● On an Amish Farm ● Traveling Pennsylvanians ● The Trail of the Stone Arched Bridges in Berks County ● Displaced Dutchmen Crave Shoo-flies ● Florence Starr Taylor ● Pennsylvania Dutch Pioneers ● Zinzendorf and Moravian Research ● Sheep in Dutchlandhttps://digitalcommons.ursinus.edu/dutchmanmag/1010/thumbnail.jp

Managing Static Leakage Energy in Microprocessor Functional Units

Static energy due to subthreshold leakage current is projected to become a major component of the total energy in high performance microprocessors. Many studies so far have examined and proposed techniques to reduce leakage in on-chip storage structures. In this study, static energy is reduced in the integer functional units by leveraging the unique qualities of dual threshold voltage domino logic. Domino logic has desirable properties that greatly reduce leakage current while providing fast propagation times. However, due to the energy cost of entering the low leakage current state (sleep mode), domino logic has thus far been used only for leakage reduction in the longterm standby mode. We examine the utility of the sleep mode (while considering the aforementioned costs) when idle times are relatively short, one to a few hundred cycles, as is often the case for functional units. Using an analytical energy model suitable for architecture-level analysis, we explore the interaction of the application and technology, and the effect on energy and performance as the underlying parameters are varied, on a set of benchmarks. Our results show that if the leakage approaches the magnitude as projected in the literature, even for short idle intervals as few as ten cycles, an aggressive policy of activating the sleep mode at every idle period performs well and a more complex control strategy may not be warranted. We also propose a simple design, called Gradual Sleep, to reduce the energy impact of using the sleep mode for smaller idle periods

The Dutchman Vol. 6, No. 2

● Spatterware ● That\u27s a Lot of Boloney ● A Dutch Touch ● Birds in Dutchland ● Cornelius Weygandt Day ● Brick-end Barns ● Hardly Bigger Than a Peanut ● Pennsylvania Dutch Pioneers ● Sycamores in Dutchland ● The Zehn-uhr Schtickhttps://digitalcommons.ursinus.edu/dutchmanmag/1001/thumbnail.jp

Pennsylvania Folklife Vol. 12, No. 1

• Tin: With Holes In • Nineteenth Century Shooting Matches • Dunkard Life in Lebanon Valley Sixty Years Ago • Nicholas Bervinchak • An Album of Etchings of the Pennsylvania Coal Region • Corn Culture in Pennsylvania • Rye Bread Lehigh County Style • Dutchified-English : Some Lebanon Valley Examples • The Pennsylvania Dutch Folk Festival: A European Reporthttps://digitalcommons.ursinus.edu/pafolklifemag/1009/thumbnail.jp