55,474 research outputs found
Improved elastomer for use with oxygen difluoride
Method improves resistance of CIS-1,4-poly(butadiene) elastomers to attack by oxygen difluoride at low temperatures by replacing silica reinforcement with less reactive substances. Improved elastomeric compound is utilized in bladders, diaphragms, valves, O-rings and seals
Modelling for research on chemical control of mammals in New Zealand
Development of predictive formulae or qualitative statements about the probable outcome of control campaigns entails knowledge of bait quality and distribution, behaviour, vagaries of weather at the time of the control campaign, and other factors which govern the probability that the target animals will accept bait. This paper collates experience in recognising, estimating and using some of these variables for predicting the outcome of large-scale poisoning, and discusses possible approaches to the solution of some hard-core problems
Bell's theorem as a signature of nonlocality: a classical counterexample
For a system composed of two particles Bell's theorem asserts that averages
of physical quantities determined from local variables must conform to a family
of inequalities. In this work we show that a classical model containing a local
probabilistic interaction in the measurement process can lead to a violation of
the Bell inequalities. We first introduce two-particle phase-space
distributions in classical mechanics constructed to be the analogs of quantum
mechanical angular momentum eigenstates. These distributions are then employed
in four schemes characterized by different types of detectors measuring the
angular momenta. When the model includes an interaction between the detector
and the measured particle leading to ensemble dependencies, the relevant Bell
inequalities are violated if total angular momentum is required to be
conserved. The violation is explained by identifying assumptions made in the
derivation of Bell's theorem that are not fulfilled by the model. These
assumptions will be argued to be too restrictive to see in the violation of the
Bell inequalities a faithful signature of nonlocality.Comment: Extended manuscript. Significant change
Polyimide adhesives
A process was developed for preparing aromatic polyamide acids for use as adhesives by reacting an aromatic dianhydride to an approximately equimolar amount of an aromatic diamine in a water or lower alkanol miscible ether solvent. The polyamide acids are converted to polyimides by heating to the temperature range of 200 - 300 C. The polyimides are thermally stable and insoluble in ethers and other organic solvents
Two destructive effects of decoherence on Bell inequality violation
We consider a system of two spin-1/2 particles, initially in an entangled
Bell state. If one of the particles is interacting with an environment (e.g. a
collection of N independent spins), the two-particle system undergoes
decoherence. Using a simple model of decoherence, we show that this process has
two consequences. First, the maximal amount by which the CHSH inequality is
violated decays to zero. Second, the set of directions of measurement for which
the inequality is violated is reduced in the course of decoherence. The volume
of that set is bounded above by C|r|^2, where r is the decoherence factor. We
obtain similar results for the case when each of the two particles is in
interaction with a separate environment.Comment: v2: added results for decoherence due to interactions of both
particles + minor changes; v3: minor change
Generation of GHZ and W states for stationary qubits in spin network via resonance scattering
We propose a simple scheme to establish entanglement among stationary qubits
based on the mechanism of resonance scattering between them and a
single-spin-flip wave packet in designed spin network. It is found that through
the natural dynamical evolution of an incident single-spin-flip wave packet in
a spin network and the subsequent measurement of the output single-spin-flip
wave packet,multipartite entangled states among n stationary qubits,
Greenberger-Horne-Zeilinger (GHZ) and W states can be generated.Comment: 8 pages, 6 figure
Creation and localization of entanglement in a simple configuration of coupled harmonic oscillators
We investigate a simple arrangement of coupled harmonic oscillators which
brings out some interesting effects concerning creation of entanglement. It is
well known that if each member in a linear chain of coupled harmonic
oscillators is prepared in a ``classical state'', such as a pure coherent state
or a mixed thermal state, no entanglement is created in the rotating wave
approximation. On the other hand, if one of the oscillators is prepared in a
nonclassical state (pure squeezed state, for instance), entanglement may be
created between members of the chain. In the setup considered here, we found
that a great family of nonclassical (squeezed) states can localize entanglement
in such a way that distant oscillators never become entangled. We present a
detailed study of this particular localization phenomenon. Our results may find
application in future solid state implementations of quantum computers, and we
suggest an electromechanical system consisting of an array of coupled
micromechanical oscillators as a possible implementation.Comment: 7 pages, 8 figures, minor typos fixe
Random Variables Recorded under Mutually Exclusive Conditions: Contextuality-by-Default
We present general principles underlying analysis of the dependence of random
variables (outputs) on deterministic conditions (inputs). Random outputs
recorded under mutually exclusive input values are labeled by these values and
considered stochastically unrelated, possessing no joint distribution. An input
that does not directly influence an output creates a context for the latter.
Any constraint imposed on the dependence of random outputs on inputs can be
characterized by considering all possible couplings (joint distributions)
imposed on stochastically unrelated outputs. The target application of these
principles is a quantum mechanical system of entangled particles, with
directions of spin measurements chosen for each particle being inputs and the
spins recorded outputs. The sphere of applicability, however, spans systems
across physical, biological, and behavioral sciences.Comment: In H. Liljenstr\"om (Ed.) Advances in Cognitive Neurodynamics IV (pp.
405-410) (2015
A generalized structure of Bell inequalities for bipartite arbitrary dimensional systems
We propose a generalized structure of Bell inequalities for arbitrary
d-dimensional bipartite systems, which includes the existing two types of Bell
inequalities introduced by Collins-Gisin-Linden-Massar-Popescu [Phys. Rev.
Lett. 88, 040404 (2002)] and Son-Lee-Kim [Phys. Rev. Lett. 96, 060406 (2006)].
We analyze Bell inequalities in terms of correlation functions and joint
probabilities, and show that the coefficients of correlation functions and
those of joint probabilities are in Fourier transform relations. We finally
show that the coefficients in the generalized structure determine the
characteristics of quantum violation and tightness.Comment: 6 pages, 1 figur
Process for preparing polyimide adhesives
High bonding strengths are obtained for metals and fiber-reinforced organic resin composites with no significant loss in thermo-oxidative stability of the adhesive resin
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