40,617 research outputs found
Single Z' production at CLIC based on e^- gamma collisions
We analyze the potential of CLIC based on e- gamma collisions to search for
new gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C
X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed
(RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can
be observed at the CLIC, and the cross sections in the model with RH neutrinos
are bigger than those in the minimal one.Comment: 11 pages, 4 figures, To appear in JET
Precipitation detector Patent
Precipitation detector and mechanism for stopping and restarting machinery at initiation and cessation of rai
Commensurability oscillations due to pinned and drifting orbits in a two-dimensional lateral surface superlattice
We have simulated conduction in a two-dimensional electron gas subject to a
weak two-dimensional periodic potential, . The usual commensurability oscillations in are seen with
alone. An increase of suppresses these oscillations, rather than
introducing the additional oscillations in expected from
previous perturbation theories. We show that this behavior arises from drift of
the guiding center of cyclotron motion along contours of an effective
potential. Periodic modulation in the magnetic field can be treated in the same
way.Comment: 3 pages text, 4 eps figures, revte
Effect of time delay on feedback control of a flashing ratchet
It was recently shown that the use of feedback control can improve the
performance of a flashing ratchet. We investigate the effect of a time delay in
the implementation of feedback control in a closed-loop collective flashing
ratchet, using Langevin dynamics simulations. Surprisingly, for a large
ensemble, a well-chosen delay time improves the ratchet performance by allowing
the system to synchronize into a quasi-periodic stable mode of oscillation that
reproduces the optimal average velocity for a periodically flashing ratchet.
For a small ensemble, on the other hand, finite delay times significantly
reduce the benefit of feedback control for the time-averaged velocity, because
the relevance of information decays on a time scale set by the diffusion time
of the particles. Based on these results, we establish that experimental use of
feedback control is realistic.Comment: 6 pages, 6 figures, to appear in Europhysics Letter
Engineering handbook on the atmospheric environmental guidelines for use in wind turbine generator development
The guidelines are given in the form of design criteria relative to wind speed, wind shear, turbulence, wind direction, ice and snow loading, and other climatological parameters which include rain, hail, thermal effects, abrasive and corrosive effects, and humidity. This report is a presentation of design criteria in an engineering format which can be directly input to wind turbine generator design computations. Guidelines are also provided for developing specialized wind turbine generators or for designing wind turbine generators which are to be used in a special region of the United States
Mapping the invisible hand: a body model of a phantom limb
After amputation, individuals often have vivid experiences of their absent limb (i.e., a phantom limb). Therefore, one’s conscious image of one’s body cannot depend on peripheral input only (Ramachandran & Hirstein, 1998). However, the origin of phantom sensations is hotly debated. Reports of vivid phantoms in the case of congenital absence of the limb show that memory of former body state is not necessary (Brugger et al., 2000). According to one view, phantoms may reflect innate organization of sensorimotor cortices (Melzack, 1990). Alternatively, phantoms could reflect generalization from viewing other people’s bodies (Brugger et al., 2000), a sensorimotor example of the classic theory that understanding oneself follows from understanding the “generalized other” (Mead, 1934, p. 154). Because phantom limbs cannot be stimulated, sensory testing cannot directly compare visual and somatosensory influences on representations of phantom limbs. Consequently, empirical investigation of phantoms is limited
Propellant material compatibility program and results
The effects of long-term (up to 10 years) contact of inert materials with earth-storable propellants were studied for the purpose of designing chemical propulsion system components that can be used for current as well as future planetary spacecraft. The primary experimental work, and results to date are reported. Investigations include the following propellants: hydrazine, hydrazine-hydrazine nitrate blends, monomethyl-hydrazine, and nitrogen tetroxide. Materials include: aluminum alloys, corrosion-resistant steels, and titanium alloys. More than 700 test specimen capsules were placed in long-term storage testing at 43 C in the special material compatibility facility. Material ratings relative to the 10-year requirement have been assigned
Rare Kaon Decay K^+ --> \pi^+ \nu \bar{\nu} in SU(3)_C X SU(3)_L X U(1)_N Models
The rare kaon decay K^+ --> \pi^+ \nu \bar{\nu} is considered in the
framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1)
gauge group. It is shown that a lower bound of the Z' mass in the 3 - 3 - 1
model with right-handed neutrinos at a value of 3 TeV is derived, while that in
the minimal version -- 1.7 TeV.Comment: 7 pages, 1 figure, late
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