The Thomsen model of inserts in sandwich composites: An evaluation

An one-dimensional finite element model of a sandwich panel with insert is derived using the approach used in the Thomsen model. The one-dimensional model produces results that are close to those of a two-dimensional axisysmmetric model. Both models assume that the core is homogeneous. Our results indicate that the one-dimensional model may be well suited for small deformations of sandwich specimens with foam cores.Comment: 30 pages, 14 figure

Discovering SUSY with m02<0m_0^2 < 0 in the First LHC Physics Run

In minimal supergravity, the parameter space where the slepton is the LSP is usually neglected, because of strong constraints on charged dark matter. When the gravitino is the true LSP, this region avoids these constraints and offers spectacular collider signals. We investigate this scenario for the LHC and find that a large portion of the ignored mSugra parameter space can lead to discovery within the first physics run, with 1-4 $\text{fb}^{-1}$ of data. We find that there are regions where discovery is feasible with only 1 day of running

Solar array electrical performance assessment for Space Station Freedom

Electrical power for Space Station Freedom will be generated by large Photovoltaic arrays with a beginning of life power requirement of 30.8 kW per array. The solar arrays will operate in a Low Earth Orbit (LEO) over a design life of fifteen years. This paper provides an analysis of the predicted solar array electrical performance over the design life and presents a summary of supporting analysis and test data for the assigned model parameters and performance loss factors. Each model parameter and loss factor is assessed based upon program requirements, component analysis, and test data to date. A description of the LMSC performance model, future test plans, and predicted performance ranges are also given

Encouraging Social Innovation Through Capital: Using Technology to Address Barriers

Outlines how technology can help foster a robust capital market for public education innovation by improving content, linking technology with face-to-face networks, and streamlining transactions. Suggests steps for government, foundations, and developers

The Utility of Text: The Case of Amicus Briefs and the Supreme Court

We explore the idea that authoring a piece of text is an act of maximizing one's expected utility. To make this idea concrete, we consider the societally important decisions of the Supreme Court of the United States. Extensive past work in quantitative political science provides a framework for empirically modeling the decisions of justices and how they relate to text. We incorporate into such a model texts authored by amici curiae ("friends of the court" separate from the litigants) who seek to weigh in on the decision, then explicitly model their goals in a random utility model. We demonstrate the benefits of this approach in improved vote prediction and the ability to perform counterfactual analysis.Comment: Working draf

Goldilocks Supersymmetry: Simultaneous Solution to the Dark Matter and Flavor Problems of Supersymmetry

Neutralino dark matter is well motivated, but also suffers from two shortcomings: it requires gravity-mediated supersymmetry breaking, which generically violates flavor constraints, and its thermal relic density \Omega is typically too large. We propose a simple solution to both problems: neutralinos freezeout with \Omega ~10-100, but then decay to ~1 GeV gravitinos, which are simultaneously light enough to satisfy flavor constraints and heavy enough to be all of dark matter. This scenario is naturally realized in high-scale gauge-mediation models, ameliorates small scale structure problems, and implies that ``cosmologically excluded'' models may, in fact, be cosmologically preferred.Comment: 4 pages; v2: references added; v3: published versio

Rapid thermal cycling of solar array blanket coupons for Space Station Freedom

The NASA Lewis Research Center has been conducting rapid thermal cycling on blanket coupons for Space Station Freedom. This testing includes two designs (8 coupons total) of the solar array. Four coupons were fabricated as part of the Photovoltaic Array Environmental Protection Program (PAEP), NAS3-25079, at Lockheed Missiles and Space Company. These coupons began cycling in early 1989 and have completed 172,000 thermal cycles. Four other coupons were fabricated a year later and included several design changes; cycling of these began in early 1990 and has reached 90,000 cycles. The objective of this testing is to demonstrate the durability or operational lifetime (15 yrs.) of the welded interconnects within a low earth orbit (LEO) thermal cycling environment. The blanket coupons, design changes, test description, status to date including performance and observed anomalies, and any insights related to the testing of these coupons are described. The description of a third design is included