679 research outputs found

    Anatomy of a Spin: The Information-Theoretic Structure of Classical Spin Systems

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    Collective organization in matter plays a significant role in its expressed physical properties. Typically, it is detected via an order parameter, appropriately defined for each given system's observed emergent patterns. Recent developments in information theory, however, suggest quantifying collective organization in a system- and phenomenon-agnostic way: decompose the system's thermodynamic entropy density into a localized entropy, that solely contained in the dynamics at a single location, and a bound entropy, that stored in space as domains, clusters, excitations, or other emergent structures. We compute this decomposition and related quantities explicitly for the nearest-neighbor Ising model on the 1D chain, the Bethe lattice with coordination number k=3, and the 2D square lattice, illustrating its generality and the functional insights it gives near and away from phase transitions. In particular, we consider the roles that different spin motifs play (in cluster bulk, cluster edges, and the like) and how these affect the dependencies between spins.Comment: 12 pages, 8 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/ising_bmu.ht

    A CONCEPT ON THE DEVELOPMENT OF BUPRENORPHINE AUTOINJECTOR FOR SELF AND EMERGENCY ADMINISTRATION

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    Objective: In natural and man-made disasters, pain and infection would increase morbidity and mortality. In these situations immediate treatment is mandatory and the drug has to be absorbed faster. An auto injector would be useful. The objective of this study was to develop an analgesic auto injector with buprenorphine.Methods: The auto injector is a reusable device with a disposable drug cartridge, capable of injecting 1 or 2 ml of drug solution. Sterile water filled cartridges were made from a pharmaceutical company. Water was withdrawn from the cartridge under a laminar flow and buprenorphine hydrochloride was injected to make 0.05 mg/ml concentration. Sterility test was carried out before and after injecting buprenorphine in the cartridge by nutrient agar method and aerobic and anaerobic sterility test mediums. Buprenorphine was injected, intraperitoneally in rats through autoinjector and compared with manual injection for its efficacy as an analgesic using Eddy's hot plate.Results: The water filled cartridge as well as the buprenorphine drug filled cartridge was found to be sterile as no growth was observed in the nutrient agar and no turbidity was observed in the sterility test mediums. The analgesic effect of buprenorphine by autoinjector was found to be significantly (Kruskal Wallis ANOVA) more than manual injection and control group (median analgesic time in seconds, Control-4.0; manual injection–7.0; autoinjector–12.0).Conclusion: Water filled cartridge could be converted to drug filled cartridge aseptically. Buprenorphine administered through autoinjector was better as an analgesic than manual injection.Â

    Automatic Lighting Mechanism on Highways during Midnight

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    This paper presents the key points in implementing automatic lighting mechanism on highway roads with the help of moving object detection in urban cities during midnight. The objective of the object detection system will be to detect objects confined in a particular area. The detection system will thus require important information like speed of moving objects, size of objects and number of vehicles on the road. The lighting system is responsible for switching off the lights in a particular area where the object detection monitoring system evaluates to a minimum threshold value. The lighting system will be active 350m to direction of the object moving in a particular direction

    Carbon Nanotubes: Detection of Chemical and Biological Warfare Agents

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    Discovery of carbon nanotubes has great impact on the development of newer methodologies and devicesuseful for the analysis of various types of chemicals. The functionalisation of CNTs with biomolecules relatedto chemical and biological warfare agents makes these useful for the detection of these agents. The detectionsensitivity can be increased manyfold. Various types of chemical and biological sensors were developed usingvarious type of carbon nanotubes as well as nano particles of different metals.Defence Science Journal, 2008, 58(5), pp.617-625, DOI:http://dx.doi.org/10.14429/dsj.58.168

    Optical-phonon resonances with saddle-point excitons in twisted-bilayer graphene

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    Twisted-bilayer graphene (tBLG) exhibits van Hove singularities in the density of states that can be tuned by changing the twisting angle θ\theta. A θ\theta-defined tBLG has been produced and characterized with optical reflectivity and resonance Raman scattering. The θ\theta-engineered optical response is shown to be consistent with persistent saddle-point excitons. Separate resonances with Stokes and anti-Stokes Raman scattering components can be achieved due to the sharpness of the two-dimensional saddle-point excitons, similar to what has been previously observed for one-dimensional carbon nanotubes. The excitation power dependence for the Stokes and anti-Stokes emissions indicate that the two processes are correlated and that they share the same phonon.Comment: 5 pages, 6 figure

    Investigation of novel high T<SUB>c</SUB> superconducting oxides

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    Our results of microscopic and macroscopic studies of novel high Tc superconductors are discussed. They permit a straightforward comparison of the nature of the superconductivity in 40 K range (La2CuO4 type) and 90 K range (YBa2Cu3O7type) superconductors

    New Samarium and Neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field

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    Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25 atomic percent of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of zero magnetization axis at low magnetic fields (less than 103 Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with no net magnetization and appreciable conduction electron polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of about 270 K, underscore the importance of these materials for potential applications in spintronics.Comment: 6 page text + 5 figure

    Organo-arsenic molecular layers on silicon for high-density doping

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    This article describes for the first time the controlled monolayer doping (MLD) of bulk and nanostructured crystalline silicon with As at concentrations approaching 2 x 10²⁰ atoms cm⁻³. Characterization of doped structures after the MLD process confirmed that they remained defect- and damage-free, with no indication of increased roughness or a change in morphology. Electrical characterization of the doped substrates and nanowire test structures allowed determination of resistivity, sheet resistance, and active doping levels. Extremely high As-doped Si substrates and nanowire devices could be obtained and controlled using specific capping and annealing steps. Significantly, the As-doped nanowires exhibited resistances several orders of magnitude lower than the predoped materials

    LNCS

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    We solve the offline monitoring problem for timed propositional temporal logic (TPTL), interpreted over dense-time Boolean signals. The variant of TPTL we consider extends linear temporal logic (LTL) with clock variables and reset quantifiers, providing a mechanism to specify real-time constraints. We first describe a general monitoring algorithm based on an exhaustive computation of the set of satisfying clock assignments as a finite union of zones. We then propose a specialized monitoring algorithm for the one-variable case using a partition of the time domain based on the notion of region equivalence, whose complexity is linear in the length of the signal, thereby generalizing a known result regarding the monitoring of metric temporal logic (MTL). The region and zone representations of time constraints are known from timed automata verification and can also be used in the discrete-time case. Our prototype implementation appears to outperform previous discrete-time implementations of TPTL monitoring

    Graphene Photonics and Optoelectronics

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    The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres
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