6,134 research outputs found
Development of basic theories and techniques for determining stresses in rotating turbine or compressor blades
A method for measuring in-plane displacement of a rotating structure by using two laser speckle photographs is described. From the displacement measurements one can calculate strains and stresses due to a centrifugal load. This technique involves making separate speckle photographs of a test model. One photograph is made with the model loaded (model is rotating); the second photograph is made with no load on the model (model is stationary). A sandwich is constructed from the two speckle photographs and data are recovered in a manner similar to that used with conventional speckle photography. The basic theory, experimental procedures of this method, and data analysis of a simple rotating specimen are described. In addition the measurement of in-plane surface displacement components of a deformed solid, and the application of the coupled laser speckle interferometry and boundary-integral solution technique to two dimensional elasticity problems are addressed
Model-independent analysis for determining mass splittings of heavy baryons
We study the hyperfine mass differences of heavy hadrons in the heavy quark
effect theory (HQET). The effects of one-gluon exchange interaction are
considered for the heavy mesons and baryons. Base on the known experimental
data, we predict the masses of some heavy baryons in a model-independent way.Comment: 14 pages, 1 figur
The Kolmogorov-Smirnov test and its use for the identification of fireball fragmentation
We propose an application of the Kolmogorov-Smirnov test for rapidity
distributions of individual events in ultrarelativistic heavy ion collisions.
The test is particularly suitable to recognise non-statistical differences
between the events. Thus when applied to a narrow centrality class it could
indicate differences between events which would not be expected if all events
evolve according to the same scenario. In particular, as an example we assume
here a possible fragmentation of the fireball into smaller pieces at the
quark/hadron phase transition. Quantitative studies are performed with a Monte
Carlo model capable of simulating such a distribution of hadrons. We conclude
that the Kolmogorov-Smirnov test is a very powerful tool for the identification
of the fragmentation process.Comment: 9 pages, 10 figure
Analysis of pectate lyase genes in Dickeya chrysanthemi strain L11, isolated from a recreational lake in Malyasia: a draft genome sequence perspective
YesDickeya chrysanthemi is well known as a plant pathogen that caused major blackleg in the European potato industry in the 1990s. D. chrysanthemi strain L11 was discovered in a recreational lake in Malaysia. Here, we present its draft genome sequence.University of Malaya High Impact Research (HIR) Grants UM C/625/1/HIR/MOHE/CHAN/01 (grant no. A-000001-50001) and UM C/625/1/HIR/MOHE/CHAN/14/1 (grant no. H-50001-A000027
Searching for Perfect Fluids: Quantum Viscosity in a Universal Fermi Gas
We measure the shear viscosity in a two-component Fermi gas of atoms, tuned
to a broad s-wave collisional (Feshbach) resonance. At resonance, the atoms
strongly interact and exhibit universal behavior, where the equilibrium
thermodynamic properties and the transport coefficients are universal functions
of the density and temperature . We present a new calibration of the
temperature as a function of global energy, which is directly measured from the
cloud profiles. Using the calibration, the trap-averaged shear viscosity in
units of is determined as a function of the reduced temperature at
the trap center, from nearly the ground state to the unitary two-body regime.
Low temperature data is obtained from the damping rate of the radial breathing
mode, while high temperature data is obtained from hydrodynamic expansion
measurements. We also show that the best fit to the high temperature expansion
data is obtained for a vanishing bulk viscosity. The measured trap-averaged
entropy per particle and shear viscosity are used to estimate the ratio of the
shear viscosity to the entropy density, which is compared that conjectured for
a perfect fluid.Comment: 20 pages, 10 figure
Generating scalable graph states in an atom-nanophotonic interface
Scalable graph states are essential for measurement-based quantum computation
and many entanglement-assisted applications in quantum technologies. Generation
of these multipartite entangled states requires a controllable and efficient
quantum device with delicate design of generation protocol. Here we propose to
prepare high-fidelity and scalable graph states in one and two dimensions,
which can be tailored in an atom-nanophotonic cavity via state carving
technique. We propose a systematic protocol to carve out unwanted state
components, which facilitates scalable graph states generations via adiabatic
transport of a definite number of atoms in optical tweezers. An analysis of
state fidelity is also presented, and the state preparation probability can be
optimized via multiqubit state carvings and sequential single-photon probes.
Our results showcase the capability of an atom-nanophotonic interface for
creating graph states and pave the way toward novel problem-specific
applications using scalable high-dimensional graph states with stationary
qubits.Comment: 5 figures with supplemental materia
Nanomechanical-resonator-assisted induced transparency in a Cooper-pair-box system
We propose a scheme to demonstrate the electromagnetically induced
transparency (EIT) in a system of a superconducting Cooper-pair box coupled to
a nanomechanical resonator. In this scheme, the nanomechanical resonator plays
an important role to contribute additional auxiliary energy levels to the
Cooper-pair box so that the EIT phenomenon could be realized in such a system.
We call it here resonator-assisted induced transparency (RAIT). This RAIT
technique provides a detection scheme in a real experiment to measure physical
properties, such as the vibration frequency and the decay rate, of the coupled
nanomechanical resonator.Comment: To appear in New Journal of Physics: Special Issue "Mechanical
Systems at the Quantum Limit
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