19,189 research outputs found
Fluorescence antibunching microscopy
Breaking the diffraction limit in microscopy by utilizing quantum properties
of light has been the goal of intense research in the recent years. We propose
a quantum superresolution technique based on non-classical emission statistics
of fluorescent markers, routinely used as contrast labels for bio-imaging. The
technique can be readily implemented using standard fluorescence microscopy
equipment
Analysis of a fixed-pitch X-wing rotor employing lower surface blowing
Lower surface blowing (LSB) is investigated as an alternative to the variable blade pitch requirement for the X-wing Circulation Control (CC) rotor concept. Addition trailing edge blowing slots on the lower surfaces of CC airfoils provide a bidirectional lift capability that effectively doubles the control range. The operational requirements of this rotor system are detailed and compared to the projected performance attributes of LSB airfoils. Analysis shows that, aerodynamically, LSB supplies a fixed pitch rotor system with the equivalent lift efficiency and rotor control of present CC rotor designs that employ variable blade pitch. Aerodynamic demands of bidirectional lift production are predicted to be within the capabilities of current CC airfoil design methodology. Emphasis in this analysis is given to the high speed rotary wing flight regime unique to stoppable rotor aircraft. The impact of a fixed pitch restriction in hover and low speed flight is briefly discussed
Infinite Dimensional Free Algebra and the Forms of the Master Field
We find an infinite dimensional free algebra which lives at large N in any
SU(N)-invariant action or Hamiltonian theory of bosonic matrices. The natural
basis of this algebra is a free-algebraic generalization of Chebyshev
polynomials and the dual basis is closely related to the planar connected
parts. This leads to a number of free-algebraic forms of the master field
including an algebraic derivation of the Gopakumar-Gross form. For action
theories, these forms of the master field immediately give a number of new
free-algebraic packagings of the planar Schwinger-Dyson equations.Comment: 39 pages. Expanded historical remark
Modelling Groundwater Contamination Above High-Level Nuclear-Waste Repositories in Salt, Granitoid and Clay
Constraining Light Colored Particles with Event Shapes
Using recently developed techniques for computing event shapes with
Soft-Collinear Effective Theory, LEP event shape data is used to derive strong
model-independent bounds on new colored particles. In the effective field
theory computation, colored particles contribute in loops not only to the
running of alpha_s but also to the running of hard, jet and soft functions.
Moreover, the differential distribution in the effective theory explicitly
probes many energy scales, so event shapes have strong sensitivity to new
particle thresholds. Using thrust data from ALEPH and OPAL, colored adjoint
fermions (such as a gluino) below 51.0 GeV are ruled out to 95% confidence
level. This is nearly an order-of-magnitude improvement over the previous
model-independent bound of 6.3 GeV.Comment: 4 pages, 2 figure
Ducks on the torus: existence and uniqueness
We show that there exist generic slow-fast systems with only one
(time-scaling) parameter on the two-torus, which have canard cycles for
arbitrary small values of this parameter. This is in drastic contrast with the
planar case, where canards usually occur in two-parametric families. Here we
treat systems with a convex slow curve. In this case there is a set of
parameter values accumulating to zero for which the system has exactly one
attracting and one repelling canard cycle. The basin of the attracting cycle is
almost the whole torus.Comment: To appear in Journal of Dynamical and Control Systems, presumably
Vol. 16 (2010), No. 2; The final publication is available at
www.springerlink.co
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