Metamaterial window glass for adaptable energy efficiency

textA computational analysis of a metamaterial window design is presented for the purpose of increasing the energy efficiency of buildings in seasonal or cold climates. Commercial low-emissivity windows use nanometer-scale Ag films to reflect infrared energy, while retaining most transmission of optical wavelengths for functionality. An opportunity exists to further increase efficiency through a variable emissivity implementation of Ag thin-film structures. 3-D finite-difference time-domain simulations predict non-linear absorption of near-infrared energy, providing the means to capture a substantial portion of solar energy during cold periods. The effect of various configuration parameters is quantified, with prediction of the net sustainability advantage. Metamaterial window glass technology can be realized as a modification to current, commercial low-emissivity windows through the application of nano-manufactured films, creating the opportunity for both new and after-market sustainable construction.Mechanical Engineerin

The Road Not Taken: Horace Mann Charter Schools in Massachusetts

Drawing on research with legislators, leaders at the Massachusetts Department of Education, heads of the major education associations, and charter school experts, this policy analysis seeks to identify reasons for the lack of interest in Horace Mann charter schools. Once touted as a potentially revolutionary new school alternative, Horace Mann charter schools now are an almost totally abandoned education reform option. In stark contrast to the popularity of Commonwealth charter schools, not a single application for a Horace Mann charter has been filed in the past two years. The report finds that some of the challenges to the creation of Horace Mann charters include: political challenges, financial disincentives, and a general lack of information.Commonwealth charter schools, which operate as independent of mainstream school districts, are highly popular among educators, parents and the students who attend them. Yet, they have consistently generated remarkable acrimony and controversy within the education community. By contrast, Horace Mann charter schools, which operate as part of mainstream districts, hold political promise for diminishing the damaging controversies surrounding Commonwealth charter schools. This political promise has not, however, increased the appeal of Horace Mann charter schools. Even with more than twice as many Horace Mann charters available and a higher approval rate than Commonwealth charters, Horace Mann charter schools have remained grossly underutilized.Recommendations:This analysis recommends that legislators and policy makers create a sense of urgency about resurrecting the Horace Mann charter school option. Policy recommendations include: Clarifying roles and responsibilities for the leadership constituencies of Horace Mann charters;Extending the outreach efforts to promote Horace Mann charters as a model for addressing specific educational challenges, such as converting low performing schools; andEstablishing support mechanisms for prospective Horace Mann leaders.In order to adequately address these recommendations, the Rennie Center report calls for policy makers to take a more active interest in cultivating the Horace Mann model

Liouville Black Holes

The dynamics of Liouville fields coupled to gravity are investigated by applying the principle of general covariance to the Liouville action in the context of a particular form of two-dimensional dilaton gravity. The resultant field equations form a closed system for the Liouville/gravity interaction. A large class of asymptotically flat solutions to the field equations is obtained, many of which can be interpreted as black hole solutions. The temperature of such black holes is proportional to their mass-parameters. An exact solution to the back reaction problem is obtained to one-loop order, both for conformally coupled matter fields and for the quantized metric/Liouville system. Quantum effects are shown to map the space of classical solutions into one another. A scenario for the end-point of black-hole radiation is discussed.Comment: 32 pgs., WATPHYS-TH93/03 (Latex plus two postscript figures appended

Murray Gell-Mann, A Short Appreciation

On September 25, 2014 Murray Gell-Mann was presented with the Helmholz Medal of the Berlin Brandenburg Academy of Sciences and Humanities in a ceremony at the Santa Fe Institute. The author, among others, was asked to speak for fifteen minutes on Murray and his accomplishments. The following is an edited transcription of the author's speaking text.Comment: 6 pages, revtex, picture added, typos fixe

‘We do our bit in our own space’: DAL Group and the development of a curiously Sudanese enclave economy

The family firm, DAL group, is Sudan’s largest and most diversified company. Its growth has concentrated on consumer goods, rather than on state concessions or exports. It has developed its own training programs, construction units, transportation networks and market research departments to manage the unstable environment outside its business walls. This paper focuses on the company’s recruitment policies, demonstrating how the firm relies on its own internal family structure and a transnational network of Sudanese professionals in order to grow and prosper. Such self-reliance contributes to growing political frustration among young unemployed people. Graduates from ‘marginal’ areas rely more heavily on public advertisements and on information obtained from state bodies, not the private channels of wasta (personal intermediation) that cut through contemporary business. The paper concludes by comparing DAL with similar business networks in Ethiopia and Rwanda arguing that DAL is a unique and interesting form of ‘enclave economy,’ shaped by a displaced transnational elite operating in a hostile political environment. Within the wider political context of Sudan, there is a limit to what similar businesses can achieve

Letter from Margaret Mann to Mark Rich

This letter from Margaret Mann, secretary and instructor in stenography and typewriting at McMinnville College (later Linfield College), provides a response to a letter Mark Rich wrote before beginning his first year at the college. The letter answers questions regarding class requirements and his scholarship, and it explains the beginning of the fall semester was pushed back to October 1 because of a scarcity of labor.https://digitalcommons.linfield.edu/lca_rich/1001/thumbnail.jp