835 research outputs found

    Simulation of mirror inversion of quantum states in an XY spin chain using NMR

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    We report an experimental quantum simulation of unitary dynamics of an XY spin chain with pre-engineered couplings. Using this simulation, we demonstrate the mirror inversion of quantum states, proposed by Albanese et al. [Phys. Rev. Lett. 93, 230502 (2004)]. The experiment is performed with a 5-qubit dipolar coupled spin system using nuclear magnetic resonance techniques. To perform quantum simulation we make use of the recently proposed unitary operator decomposition algorithm of Ajoy et al. [Phys. Rev. A 85, 030303 (2012)] along with numerical pulse optimization techniques. Further, using mirror inversion, we demonstrate that entangled states can be transferred from one end of the chain to the other end. The simulations are implemented with high experimental fidelity, which implies that these kind of simulations may be possible in larger systems.Comment: 9 pages, 6 figure

    Development of a creep data base management system for engineering materials

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    A fully menu driven creep data base management system has been developed for various high temperature materials using the client /server (C/S) architecture with Sybase system. 10 as backend and power builder 4.0 as an inter-face. The relational data base constitutes of various classes of materials, their heat treatment, prior history and the related creep properties at different test condit-ions, in addition to the source process route and chemical composition details.Top-down approach has been adopted in designing the entity-relationship (E-R) model. The creep data is organized into the third normal form, and the entire system is divided into manageable modules. Coding for the system is done using Transact-SQL for data defin- ition, manipulation and control operations, and power script language for application development. This article briefly outlines the formulation of data base design, and the implemented E-R model, in addition , to the prese-ntation of various screen formats used for data entry and retrieval modules

    Love Wave Propagation in Poro elasticity

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    It is observed that on similar reasons as in classical theory of elasticity, SH wave propagation in a semi infinite poroelastic body is not possible and is possible when there is a layer of another poro elastic medium over it i.e., Love waves. Two particular cases are considered in one of which phase velocity can be determined for a given wave length. In the same case, equation for phase velocity is of the same form as that of the classical theory of Elasticity

    Effect of Dietary Protein Quality on the Biochemical Adaptation to High Altitude

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    The usefulness of a particular type of dietary protein for a quicker acclimatization to simulated high altitude stress was investigated in albino rats, by studying the changes occurring in the levels of urea cycle enzymes in liver. A good quality protein in (egg) and a commonly used dal protein (arhar dal, Cajanus cajan) were studied.Liver arginase levels increased on starvation in the two groups of rats fed with egg and dal diets, the increase being less and gradual in the dal diet fed group. Exposure to the simulated altitude stress for various periods further increased the enzyme levels, greater changes being seen in egg diet fed group only. Similar observations were made with liver ornithine transcarbamylase which is a mitochondrial enzyme. Urea cycle enzymes were affected more in the exposed animals maintained on the egg diet than those on the dal diet. Moreover, the enzymic parameters of the latter group tended to return to the normal level much earlier than the former. It is, therefore, suggested that not-so-well-balanced dietary proteins may be well suited to overcome the initial problem of metabolic adaptation faced by subjects exposed to high altitude stress

    Measurement of an Effective Mass Attenuation Coefficient for Fission Fragments in Uranium Targets

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    DSP Based Sensorless Control Of A BLDC Motor With Direct Back EMF Detection Method.

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    This paper proposes a scheme for sensorless control of brushless dc (BLDC) motor by a direct back EMF detection method

    Carbon-13 enrichment by IR laser chemistry of CHF<SUB>3</SUB>-Cl<SUB>2</SUB>

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    IR laser chemistry of CHF3 is investigated in both neat form and in the presence of Cl2 for carbon-13 enrichment. Infrared multiple-photon dissociation of CHF3 is an order of magnitude more efficient in the scavenged system compared to the neat case. The photolysis of CHF3/Cl2 mixture results in two products, viz., CF2Cl2 and C2F4Cl2 but with different enrichment factors. The parametric studies show that C2F4Cl2 arises due to MPD of CF2Cl2 in secondary photolysis

    Monogamy of quantum correlations reveals frustration in a quantum Ising spin system: Experimental demonstration

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    We report a nuclear magnetic resonance experiment, which simulates the quantum transverse Ising spin system in a triangular configuration and further show that the monogamy of quantum correlations can be used to distinguish between the frustrated and non-frustrated regimes in the ground state of this system. Adiabatic state preparation methods are used to prepare the ground states of the spin system. We employ two different multipartite quantum correlation measures to analyze the experimental ground state of the system in both the frustrated and non-frustrated regimes. In particular, we use multipartite quantum correlation measures generated by monogamy considerations of negativity, a bipartite entanglement measure, and that of quantum discord, an information-theoretic quantum correlation measure. As expected from theoretical predictions, the experimental data confirm that the non-frustrated regime shows higher multipartite quantum correlations compared to the frustrated one.Comment: Title in the published version is "Multipartite quantum correlations reveal frustration in a quantum Ising spin system", 7 pages, 4 figure

    Transient isomerisation and inverse electronic relaxation of infrared multiple-photon excited Pentafluoropyridine

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    Pentafluoropyridine (PFP) undergoes fast structural isomerisation to fulvenes when irradiated with 9R(16) CO2 laser line in the fluence range 0.5-1.5 J/cm2. The unstable fulvenes slowly decay back to PFP in ms time scale. No detectable permanent dissociation of PFP was observed in the above low fluence experiments. However, by using focused CO2 laser beam for the irradiation of PFP, an emission of light in the visible/near-UV was observed. The time evolution of the luminescence reveals three peaks at 390, 460 and 500 nm on a broad background emission of 300-680 nm. These bands are assigned to the fluorescence of PFP via inverse electronic relaxation (IER) and C2 Swan bands. On prolonged irradiation of PFP in focused condition a small extent of permanent dissociation was observed with the major products as C2F4, a sooty yellow deposit and another compound presumed to be Dewar PFP

    Selective IR laser chemistry of CDF<SUB>3</SUB> in natural fluoroform

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    Selective decomposition of CDF3 at natural abundance level (&#8776;150ppm) in fluoroform has been achieved by infra-red multiple-photon excitation at moderate substrate pressure using 100 ns FWHM CO2 laser pulses. Effects of energy fluence, number of laser pulses, buffer gas pressure and substrate pressure on decomposition yield and bulk selectivity are reported and discussed
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