ATLAS Upgrade Instrumentation in the US

Planned upgrades of the LHC over the next decade should allow the machine to operate at a center of mass energy of 14 TeV with instantaneous luminosities in the range 5--7e34 cm^-2 s^-1. With these parameters, ATLAS could collect 3,000 fb^-1 of data in approximately 10 years. However, the conditions under which this data would be acquired are much harsher than those currently encountered at the LHC. For example, the number of proton-proton interactions per bunch crossing will rise from the level of 20--30 per 50 ns crossing observed in 2012 to 140--200 every 25 ns. In order to deepen our understanding of the newly discovered Higgs boson and to extend our searches for physics beyond that new particle, the ATLAS detector, trigger, and readout will have to undergo significant upgrades. In this whitepaper we describe R&D necessary for ATLAS to continue to run effectively at the highest luminosities foreseen from the LHC. Emphasis is placed on those R&D efforts in which US institutions are playing a leading role.Comment: Snowmass contributed paper, 24 pages, 12 figure

Second law of thermodynamics for macroscopic mechanics coupled to thermodynamic degrees of freedom

Based only on classical Hamiltonian dynamics, we prove the maximum work principle in a system where macroscopic dynamical degrees of freedom are intrinsically coupled to microscopic degrees of freedom. Unlike recent identities between irreversible work and free energy, such as in the Jarzynski relation, the macroscopic dynamics is not governed by an external action but undergoes the back reaction of the microscopic degrees of freedom. Our theorems cover such physical situations as impact between macroscopic bodies, thermodynamic machines, and molecular motors.Comment: 4 pages, RevTe

The impact of the 2008 economic crisis on substance use patterns in the countries of the European Union

Background: From 2008 on, a severe economic crisis (EC) has characterized the European Union (E.U.). However, changes in substance use behavioral patterns as a result of the economic crisis in Europe, have been poorly reflected upon, and underlying mechanisms remain to be identified; Methods: In this review we explore and systematize the available data on the effect of the 2008 economic crisis on patterns of substance use and related disorders, within the E.U. countries; Results: The results show that effects of the recession need to be differentiated. A number of studies point to reductions in population’s overall substance use. In contrast, an increase in harmful use and negative effects is found within specific subgroups within the society. Risk factors include job-loss and long-term unemployment, and pre-existing vulnerabilities. Finally, our findings point to differences between types of substances in their response on economic crisis periods; Conclusions: the effects of the 2008 economic crisis on substance use patterns within countries of the European Union are two-sided. Next to a reduction in a population’s overall substance use, a number of vulnerable subgroups experience serious negative effects. These groups are in need of specific attention and support, given that there is a real risk that they will continue to suffer negative health effects long after the economic downfall has formally been ended

Optoelectronic analysis of multijunction wire array solar cells

Wire arrays have demonstrated promising photovoltaic performance as single junction solar cells and are well suited to defect mitigation in heteroepitaxy. These attributes can combine in tandem wire array solar cells, potentially leading to high efficiencies. Here, we demonstrate initial growths of GaAs on Si_(0.9)Ge_(0.1) structures and investigate III-V on Si_(1-x)Ge_x device design with an analytical model and optoelectronic simulations. We consider Si_(0.1)Ge_(0.9) wires coated with a GaAs_(0.9)P_(0.1) shell in three different geometries: conformal, hemispherical, and spherical. The analytical model indicates that efficiencies approaching 34% are achievable with high quality materials. Full field electromagnetic simulations serve to elucidate the optical loss mechanisms and demonstrate light guiding into the wire core. Simulated current-voltage curves under solar illumination reveal the impact of a varying GaAs_(0.9)P_(0.1) minority carrier lifetime. Finally, defective regions at the hetero-interface are shown to have a negligible effect on device performance if highly doped so as to serve as a back surface field. Overall, the growths and the model demonstrate the feasibility of the proposed geometries and can be used to guide tandem wire array solar cell designs

Extended Clausius Relation and Entropy for Nonequilibrium Steady States in Heat Conducting Quantum Systems

Recently, in their attempt to construct steady state thermodynamics (SST), Komatsu, Nakagwa, Sasa, and Tasaki found an extension of the Clausius relation to nonequilibrium steady states in classical stochastic processes. Here we derive a quantum mechanical version of the extended Clausius relation. We consider a small system of interest attached to large systems which play the role of heat baths. By only using the genuine quantum dynamics, we realize a heat conducting nonequilibrium steady state in the small system. We study the response of the steady state when the parameters of the system are changed abruptly, and show that the extended Clausius relation, in which "heat" is replaced by the "excess heat", is valid when the temperature difference is small. Moreover we show that the entropy that appears in the relation is similar to von Neumann entropy but has an extra symmetrization with respect to time-reversal. We believe that the present work opens a new possibility in the study of nonequilibrium phenomena in quantum systems, and also confirms the robustness of the approach by Komtatsu et al.Comment: 19 pages, 2 figure

Representation of nonequilibrium steady states in large mechanical systems

Recently a novel concise representation of the probability distribution of heat conducting nonequilibrium steady states was derived. The representation is valid to the second order in the ``degree of nonequilibrium'', and has a very suggestive form where the effective Hamiltonian is determined by the excess entropy production. Here we extend the representation to a wide class of nonequilibrium steady states realized in classical mechanical systems where baths (reservoirs) are also defined in terms of deterministic mechanics. The present extension covers such nonequilibrium steady states with a heat conduction, with particle flow (maintained either by external field or by particle reservoirs), and under an oscillating external field. We also simplify the derivation and discuss the corresponding representation to the full order.Comment: 27 pages, 3 figure

Quark-gluon plasma phenomenology from the lattice

The FASTSUM Collaboration has calculated several quantities relevant for QCD studies at non-zero temperature using the lattice technique. We report here our results for the (i) interquark potential in charmonium; (ii) bottomonium spectral functions; and (iii) electrical conductivity. All results were obtained with 2+1 flavours of dynamical fermions on an anisotropic lattice which allows greater resolution in the temporal direction.Comment: Plenary talk presented at the Strangeness in Quark Matter SQM 2013, Birmingham UK, 21-27 July 201

Designing curriculum and instruction for computer-supported complex systems teaching and learning in high school science classrooms

While research on teaching and learning about complex systems has achieved solid grounding in the learning sciences, few educational studies have focused on articulating design features for classroom implementation that can serve a modular purpose for building curricular and instructional experiences. Furthermore, despite the fact that several studies describe important roles for teachers in constructing successful classroom learning experiences, only a few of them examine how teachers’ instructional practices, knowledge, and beliefs influence student learning outcomes and the extent to which teachers are interested and willing to teach through complex systems approaches. Furthermore, we do not know what supports teachers themselves say that they need to teach about complex systems in their classrooms. In this study, we present a curriculum and instruction framework that outlines how teaching and learning about complex systems in high school science classroom contexts can be done. We articulate the features of the framework and provide examples of how the framework is translated into practice. We follow with evidence from an exploratory study conducted with 10 teachers and over 300 students aimed at understanding change in teachers’ instructional practices; the extent to which students learned from the activities; what teachers’ perceptions were in terms of utility and usability; and what other supports teachers needed

Teaching about complex systems is no simple matter: building effective professional development for computer-supported complex systems instruction

The recent next generation science standards in the United States have emphasized learning about complex systems as a core feature of science learning. Over the past 15 years, a number of educational tools and theories have been investigated to help students learn about complex systems; but surprisingly, little research has been devoted to identifying the supports that teachers need to teach about complex systems in the classroom. In this paper, we aim to address this gap in the literature. We describe a 2-year professional development study in which we gathered data on teachers’ abilities and perceptions regarding the delivery of computer-supported complex systems curricula. We present results across the 2 years of the project and demonstrate the need for particular instructional supports to improve implementation efforts, including providing differentiated opportunities to build expertise and addressing teacher beliefs about whether computational-model construction belongs in the science classroom. Results from students’ classroom experiences and learning over the 2 years are offered to further illustrate the impact of these instructional supports.National Science Foundation (U.S.). Discovery Research K– 12 (Grant 1019228

DuraTable Enterprises Inc.

In late 2017, DuraTable received a number of unsolicited inquiries regarding its interest in selling out in a going private transaction, mostly from private equity firms. Since the chairman of the board and founder, Gary Reynolds, was approaching retirement age and the largest single shareholder who had provided the seed capital to start the company was over 80 years old, Mr. Reynolds was willing to consider a sale and provided information to four or five of them to prepare bids. DuraTable was a closely held company with relatively few individuals holding the vast majority of shares. As such, DuraTable’s shares traded infrequently. As a result, Mr. Reynolds questioned if even the share price itself appropriately reflected the value of the company. As he looked forward to a meeting that would be held with Pierce the following week, Mr. Reynolds asked himself, ‘What price would reflect a fair valuation of DuraTable’s operations?