3,220 research outputs found
Standardisation of magnetic nanoparticles in liquid suspension
Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way
Transport Coefficients of Gluon Plasma
Transport coefficients of gluon plasma are calculated for a SU(3) pure gauge
model by lattice QCD simulations on and
lattices. Simulations are carried out at a slightly above the deconfinement
transition temperature , where a new state of matter is currently being
pursued in RHIC experiments. Our results show that the ratio of the shear
viscosity to the entropy is less than one and the bulk viscosity is consistent
with zero in the region, .Comment: 10 pages, Late
Equivalence of Several Chern-Simons Matter Models
Not only does Chern-Simons (CS) coupling characterize statistics, but also
spin and scaling dimension of matter fields. We demonstrate spin transmutation
in relativistic CS matter theory, and moreover show equivalence of several
models. We study CS vector model in some details, which provide consistent
check to the assertion of the equivalence.Comment: latex, 7page, IFT-478-UNC/NUP-A-93-15 A version within the length
limit for Phys. Rev. Letts (in press
Note on Gauge Theory on Fuzzy Supersphere
We construct a supermatrix model whose classical background gives
two-dimensional noncommutative supersphere. Quantum fluctuations around it give
the supersymmetric gauge theories on the fuzzy supersphere constructed by
Klimcik. This model has a parameter which can tune masses of the
particles in the model and interpolate various supersymmetric gauge theories on
sphere.Comment: 13 pages, LaTe
Smooth Paths on Three Dimensional Lattice
A particular class of random walks with a spin factor on a three dimensional
cubic lattice is studied. This three dimensional random walk model is a simple
generalization of random walk for the two dimensional Ising model. All critical
diffusion constants and associated critical exponents are calculated. Continuum
field theories such as Klein-Gordon, Dirac and massive Chern-Simons theories
are constructed near several critical points.Comment: 7 pages,NUP-A-94-
Laughlin Wave Function and One-Dimensional Free Fermions
Making use of the well-known phase space reduction in the lowest Landau
level(LLL), we show that the Laughlin wave function for the
case can be obtained exactly as a coherent state representation of an one
dimensional wave function. The system consists of copies of
free fermions associated with each of the electrons, confined in a common
harmonic well potential. Interestingly, the condition for this exact
correspondence is found to incorporate Jain's parton picture. We argue that,
this correspondence between the free fermions and quantum Hall effect is due to
the mapping of the system under consideration, to the Gaussian unitary
ensemble in the random matrix theory.Comment: 7 pages, Latex , no figure
Re-parameterization Invariance in Fractional Flux Periodicity
We analyze a common feature of a nontrivial fractional flux periodicity in
two-dimensional systems. We demonstrate that an addition of fractional flux can
be absorbed into re-parameterization of quantum numbers. For an exact
fractional periodicity, all the electronic states undergo the
re-parameterization, whereas for an approximate periodicity valid in a large
system, only the states near the Fermi level are involved in the
re-parameterization.Comment: 4 pages, 1 figure, minor changes, final version to appear in J. Phys.
Soc. Jp
Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
Phase transitions between the quantum spin Hall and the insulator phases in
three dimensions are studied. We find that in inversion-asymmetric systems
there appears a gapless phase between the quantum spin Hall and insulator
phases in three dimensions, which is in contrast with the two-dimensional case.
Existence of this gapless phase stems from a topological nature of gapless
points (diabolical points) in three dimensions, but not in two dimensions.Comment: 16 pages, 5 figure
Quantum fluctuations of the Chern-Simons theory and dynamical dimensional reduction
We consider a large-N Chern-Simons theory for the attractive bosonic matter
(Jackiw-Pi model) in the Hamiltonian collective-field approach based on the 1/N
expansion. We show that the dynamics of low-lying density excitations around
the ground-state vortex configuration is equivalent to that of the Sutherland
model. The relationship between the Chern-Simons coupling constant lambda and
the Calogero-Sutherland statistical parameter lambda_s signalizes some sort of
statistical transmutation accompanying the dimensional reduction of the initial
problem.Comment: 10 pages, 2 figure
A Calculation of Baryon Diffusion Constant in Hot and Dense Hadronic Matter Based on an Event Generator URASiMA
We evaluate thermodynamical quantities and transport coefficients of a dense
and hot hadronic matter based on an event generator URASiMA (Ultra-Relativistic
AA collision Simulator based on Multiple Scattering Algorithm). The statistical
ensembles in equilibrium with fixed temperature and chemical potential are
generated by imposing periodic boundary condition to the simulation of URASiMA,
where energy density and baryon number density is conserved. Achievement of the
thermal equilibrium and the chemical equilibrium are confirmed by the common
value of slope parameter in the energy distributions and the saturation of the
numbers of contained particles, respectively. By using the generated ensembles,
we investigate the temperature dependence and the chemical potential dependence
of the baryon diffusion constant of a dense and hot hadronic matter.Comment: 15 pages, 5 figures, LaTeX2
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