Chalker-Coddington model described by an S-matrix with odd dimensions

The Chalker-Coddington network model is often used to describe the transport properties of quantum Hall systems. By adding an extra channel to this model, we introduce an asymmetric model with profoundly different transport properties. We present a numerical analysis of these transport properties and consider the relevance for realistic systems.Comment: 7 pages, 4 figures. To appear in the EP2DS-17 proceeding

Caddoan Ceremonial Sites of the Caddoan Cultural Area of Arkansas, Louisiana, Oklahoma, and Texas: Draft Caddo National Landmark Nomination

Since 1997, we have been working on the development of a National Historic Landmark (NHL) cover nomination for Caddoan ceremonial sites - earthen mounds in the Caddoan cultural area of southwestern Arkansas, northwestern Louisiana, eastern Oklahoma, and northeastern Texas. Such a nomination establishes the historic context within which all similar cultural properties can be evaluated for significance according to the NHL criteria, as it establishes the research and other criteria by which a cultural property may be identified as a significant archeological resource

The NWRA Classification Infrastructure: Description and Extension to the Discriminant Analysis Flare Forecasting System (DAFFS)

A classification infrastructure built upon Discriminant Analysis has been developed at NorthWest Research Associates for examining the statistical differences between samples of two known populations. Originating to examine the physical differences between flare-quiet and flare-imminent solar active regions, we describe herein some details of the infrastructure including: parametrization of large datasets, schemes for handling "null" and "bad" data in multi-parameter analysis, application of non-parametric multi-dimensional Discriminant Analysis, an extension through Bayes' theorem to probabilistic classification, and methods invoked for evaluating classifier success. The classifier infrastructure is applicable to a wide range of scientific questions in solar physics. We demonstrate its application to the question of distinguishing flare-imminent from flare-quiet solar active regions, updating results from the original publications that were based on different data and much smaller sample sizes. Finally, as a demonstration of "Research to Operations" efforts in the space-weather forecasting context, we present the Discriminant Analysis Flare Forecasting System (DAFFS), a near-real-time operationally-running solar flare forecasting tool that was developed from the research-directed infrastructure.Comment: J. Space Weather Space Climate: Accepted / in press; access supplementary materials through journal; some figures are less than full resolution for arXi

High strength steel in fire

High-performance materials are necessary to meet the future demands of the construction industry, which is strongly influenced by a growing population and depletion of natural resources. Sustainable development is central to research and development into innovative structural materials, and requires solutions to be economically viable whilst equally providing a positive contribution towards environmental and social factors. High strength steels (HSS) have the potential to contribute towards such demands by reducing the weight of structures when employed in appropriate applications. Lighter structures require smaller foundations, shorter transportation and construction times and also lower CO2 emissions. A particular challenge related to the use of HSS in structures include increased likelihood of stability issues resulting from the reduction in section thickness, and limiting deflection and vibration criteria are also more likely to be critical. Nevertheless, when used appropriately, they can provide a sustainable solution. Their use in structural applications is further hindered by a lack of performance data and design guidance under fire conditions. This paper compares the mechanical properties, particularly strength and stiffness of HSS (yield strengths between 460-700 MPa) and mild steel (yields between 235-460 MPa) at elevated temperatures, through a critical review of published literature. Various alloying and processing routes used to achieve high yield strength are assessed. At the same time, the review considers available information on the strengthening mechanisms that can be utilised to retain the strength and/or stiffness of the material in the event of a fire. Using the information gathered, an extensive testing programme is developed which will enable design guidance for the fire design of HSS structures to be proposed.Engineering and Physical Sciences Research Council, TW

Electronic doctoral theses in the UK: a sector-wide survey into policies, practice and barriers to Open Access

Sharing knowledge and research outputs is critical to the progress of science and human development, and a central tenet of academia. The Internet itself is a product of the academic community, and opening access to that community’s most important body of research, doctoral theses, is both a logical and an inevitable development. Progress toward open access to electronic theses has been slow in the UK. Much has been written on the perceived barriers and practical/infrastructural considerations that might explain this, but a comprehensive picture of that progress, and obstacles to it, was lacking. In 2010, a survey of policy and practice in UK HEIs was conducted by UCL (University College London) Library Services (commissioned by the Joint Information Systems Committee, JISC) to address this very issue. Incorporating inputs from 144 institutions currently awarding doctoral degrees, the work provides the first clear and detailed picture of the status of open access to doctoral research in the UK. The mission of the UK Council for Graduate Education (UKCGE) is to promote and support the interests of graduate education, and this it does through dissemination of best practice and intelligence on emergent trends; helping to shape policy and practice for the benefit of the UK HEI sector. This report contributes to that mission by bringing to the membership’s attention the results of this important work by UCL Library Services; a collaboration between UKCGE and the authors of the original work, it sets out the policies and practices that emerged from the survey and also considers what has been learned about the perceived barriers to the implementation of open access to electronic theses. The 2010 survey has enabled, for the first time, a differentiation to be made between barriers that are “real” and those which are unfounded and/or yet to be properly validated. At the same time, the work highlights the progress made in certain critical areas, as well as those that require our greater attention. A positive picture emerges for the UK on the adoption of the electronic thesis, with the majority of HEIs surveyed expected to be providing open access to their theses in five years’ time. A more detailed picture also emerges regarding the primary reasons for requests to restrict access to theses, some of which, notably, apply only to electronic (not print) theses. This has necessarily given rise to new policy developments. There is positive evidence also of collaboration among HEIs to provide an efficient and robust service for accessing electronic theses; pooling their resources and expertise either in the development of their institutional repositories or in operating a joint service. The key driver of open access to electronic theses is the opportunity for UK HEIs to “showcase” their research outputs to the widest possible audience and enhance their impact. There are no reliable means as yet to measure this impact, but there are encouraging early indications that electronic doctoral theses attract significant attention when made openly accessible. Open access to electronic theses may therefore indeed accelerate the sharing of knowledge and the progress of scientific discovery and human development

Dissociation cross sections of ground-state and excited charmonia with light mesons in the quark model

We present numerical results for the dissociation cross sections of ground-state, orbitally- and radially-excited charmonia in collisions with light mesons. Our results are derived using the nonrelativistic quark model, so all parameters are determined by fits to the experimental meson spectrum. Examples of dissociation into both exclusive and inclusive final states are considered. The dissociation cross sections of several C=(+) charmonia may be of considerable importance for the study of heavy ion collisions, since these states are expected to be produced more copiously than the J/psi. The relative importance of the productions of ground-state and orbitally-excited charmed mesons in a pion-charmonium collision is demonstrated through the $\sqrt {s}$-dependent charmonium dissociation cross sections.Comment: 9 pages, 8 figure

Quality of life and building design in residential and nursing homes for older people

Older people living in residential and nursing care homes spend a large proportion of their time within the boundaries of the home, and may depend on the environment to compensate for their physical or cognitive frailties. Regulations and guidelines on the design of care buildings have accumulated over time with little knowledge of their impact on the quality of life of building users. The Design in Caring Environments Study (DICE) collected cross-sectional data on building design and quality of life in 38 care homes in and near Sheffield, Yorkshire. Quality of life was assessed using methods which included all residents regardless of their frailty, and staff morale was also assessed. The physical environment was measured on 11 user-related domains using a new tool, the Sheffield Care Environment Assessment Matrix (SCEAM). Significant positive associations were found between several aspects of the built environment and the residents' quality of life. There was evidence that a focus on safety and health requirements could be creating risk-averse environments which act against quality of life, particularly for the least frail residents. Staff morale was associated with attributes of a non-institutional environment for residents rather than with the facilities provided for the staff. The new tool for assessing building design has potential applications in further research and for care providers

J/Psi and Psi' Suppression in Hadronic Matter

We present a microscopic calculation of the breakup cross sections of $J/\psi$ and $\psi'$ on pions and nucleons as a function of the kinetic energy. These cross sections are used for the investigation of the $J/\psi$ to continuum and $\psi'/J/\psi$ ratios in ultrarelativistic heavy ion collisions. The contribution of produced comoving pions to the $\psi'/J/\psi$ signal is calculated. While this model can account for the data, the uncertainties in the parameter values do not allow to exclude the possibility of additional sources for charmonium absorption, like a resonance gas or the quark gluon plasma.Comment: LaTeX, 6 pages including 2 EPS files, to be published in Prog. Part. Nucl. Phys., [email protected]