Entropic long range order in a 3D spin glass model

We uncover a new kind of entropic long range order in finite dimensional spin glasses. We study the link-diluted version of the Edwards-Anderson spin glass model with bimodal couplings (J=+/-1) on a 3D lattice. By using exact reduction algorithms, we prove that there exists a region of the phase diagram (at zero temperature and link density low enough), where spins are long range correlated, even if the ground states energy stiffness is null. In other words, in this region twisting the boundary conditions cost no energy, but spins are long range correlated by means of pure entropic effects.Comment: 15 pages, 6 figures. v3: added a phase diagram for ferromagnetically biased coupling

Towards Understanding Photodegradation Pathways in Lignins:The Role of Intramolecular Hydrogen Bonding in Excited States

The photoinduced dynamics of the lignin building blocks syringol, guaiacol, and phenol were studied using time-resolved ion yield spectroscopy and velocity map ion imaging. Following irradiation of syringol and guaiacol with a broad-band femtosecond ultraviolet laser pulse, a coherent superposition of out-of-plane OH torsion and/or OMe torsion/flapping motions is created in the first excited 1ππ* (S1) state, resulting in a vibrational wavepacket, which is probed by virtue of a dramatic nonplanar → planar geometry change upon photoionization from S1 to the ground state of the cation (D0). Any similar quantum beat pattern is absent in phenol. In syringol, the nonplanar geometry in S1 is pronounced enough to reduce the degree of intramolecular H bonding (between OH and OMe groups), enabling H atom elimination from the OH group. For guaiacol, H bonding is preserved after excitation, despite the nonplanar geometry in S1, and prevents O–H bond fission. This behavior affects the propensities for forming undesired phenoxyl radical sites in these three lignin chromophores and provides important insight into their relative “photostabilities” within the larger biopolymer

A HyperTransport-Enabled Global Memory Model For Improved Memory Efficiency

Abstract Modern data centers are presenting unprecedented demands in terms of cost and energy consumption, far outpacing architectural advances. Consequently, blade designs exhibit significant cost and power inefficiencies, particularly in the memory system. We propose a HyperTransport-enabled solution called the Dynamic Partitioned Global Address Space (DPGAS) model for seamless, efficient sharing of memory across blades in a data center, leading to significant power and cost savings. This paper presents the DPGAS model, describes HyperTransport-based hardware support for the model, and assesses this model's power and cost impact on memory intensive applications. Overall, we find that cost savings can range from 4% to 26% with power reductions ranging from 2% to 25% across a variety of fixed application configurations using server consolidation and memory throttling. The HyperTransport implementation enables these savings with an additional node latency cost of 1,690 ns latency per remote 64 byte cache line access across the blade-to-blade interconnect

Scaling of the coercivity with the geometrical parameters in epitaxial Fe antidot arrays

We studied a series of square lattice antidot arrays, with diameter and lattice parameter from hundreds of nanometers to some microns, fabricated using two lithography techniques in epitaxial Fe(001) films. The coercivity increase of each array with respect to its base film can be scaled to a simple geometric parameter, irrespective of the lithography technique employed. Magnetic transmission x-ray microscopy studies, in arrays fabricated on polycrystalline Fe films deposited on silicon nitride membranes, evidenced the propagation of reversed domains from the edges of the arrays, in agreement with the coercivity analysis of the epitaxial arrays and with micromagnetic models

Challenges faced in transferring economic evaluations to middle income countries

BACKGROUND: Decision makers in middle income countries are using economic evaluations (EEs) in pricing and reimbursement decisions for pharmaceuticals. However, whilst many of these jurisdictions have local submission guidelines and local expertise, the studies themselves often use economic models developed elsewhere and elements of data from countries other than the jurisdiction concerned. The objectives of this study were to describe the current situation and to assess the challenges faced by decision makers in transferring data and analyses from other jurisdictions. METHODS: Experienced health service researchers in each region conducted an interview survey of representatives of decision making bodies from jurisdictions in Asia, Central and Eastern Europe, and Latin America that had at least one year’s experience of using EEs. RESULTS: Representatives of the relevant organizations in 12 countries were interviewed. All 12 jurisdictions had developed official guidelines for the conduct of EEs. All but one of the organizations evaluated studies submitted to them, but 9 also conducted studies and 7 commissioned them. Nine of the organizations stated that, in evaluating EEs submitted to them, they had consulted a study performed in a different jurisdiction. Data on relevant treatment effect was generally considered more transferable than those on prices/unit costs. Views on the transferability of epidemiological data, data on resource use and health state preference values were more mixed. Eight of the respondents stated that analyses submitted to them had used models developed in other jurisdictions. Four of the organizations had a policy requiring models to be adapted to reflect local circumstances. The main obstacles to transferring EEs were the different patterns of care or wealth of the developed countries from which most economic evaluations originate. CONCLUSIONS: In middle income countries it is commonplace to deal with the issue of transferring analyses or data from other jurisdictions. Decision makers in these countries face several challenges, mainly due to differences in current standard of care, practice patterns or GDP between the developed countries where the majority of the studies are conducted and their own jurisdiction

Optical bistability with a repulsive optical force in coupled silicon photonic crystal membranes

We demonstrate actuation of a silicon photonic crystal membrane with a repulsive optical gradient force. The extent of the static actuation is extracted by examining the optical bistability as a combination of the optomechanical, thermo-optic, and photo-thermo-mechanical effects using coupled-mode theory. Device behavior is dominated by a repulsive optical force which results in displacements of ≈ 1 nm/mW. By employing an extended guided resonance which effectively eliminates multi-photon thermal and electronic nonlinearities, our silicon-based device provides a simple, non-intrusive solution to extending the actuation range of micro-electromechanical devices.United States. Defense Advanced Research Projects Agency. (Contract N66001-09-1-2070-DOD

Compostaje de la cama de pollo como procedimiento para la eliminación de microorganismos patógenos

El uso de cama de pollo sin tratar en los sistemas hortícolas, implica un riesgo de salud de magnitud. Ahondamos en el tema para proponer estrategias saludables de su utilizaciónEEA BalcarceFil: Pellegrini, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Instituto de Ciencia y Tecnología de Alimentos y Ambiente; Argentina.Fil: Ponce, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Instituto de Ciencia y Tecnología de Alimentos y Ambiente; Argentina.Fil: Okada, Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Lavallén, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Dopchiz, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina.Fil: Pérez, Débora. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Carciochi, Walter. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Carciochi, Walter. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Young, Brian. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina