The effects of collisions are often neglected in theoretical analyses of low collisionality plasmas where the collision rate ν is smaller than the frequency of waves or other physical processes being considered. However, small angle Coulomb collisions scatter the velocity vector v of charged particles and produce slightly probabilistic rather than fully deterministic charged particle trajectori...

A number of phosphatidylcholine (PC) cations spanning a mass range of 400-1000 Da are investigated using electrospray ionization mass spectrometry coupled with traveling wave ion mobility spectrometry (TWIMS). A high correlation between mass and mobility is demonstrated with saturated phosphatidylcholine cations in N(2). A significant deviation from this mass-mobility correlation line is observ...

This paper presents an exact probability process analysis for high-speed and realizing fully distributed wireless LANs with non-persistent carrier sense multiple access with collision avoidance (CSMA/CA). The collision avoidance portion of CSMA/CA in this model is performed with a random pulse transmission procedure, in which a user with a packet ready to transmit initially sends some pulse sig...

We investigate the accuracy of and assumptions underlying the numerical binary Monte Carlo collision operator due to Nanbu [K. Nanbu, Phys. Rev. E 55 (1997) 4642]. The numerical experiments that resulted in the parameterization of the collision kernel used in Nanbu’s operator are argued to be an approximate realization of the Coulomb–Lorentz pitchangle scattering process, for which an analytica...

The interstellar reaction of ground-state carbon atom with the simplest polyyne, diacetylene HCCCCH , is investigated theoretically to explore probable routes to form hydrogen-deficient carbon clusters at ultralow temperature in cold molecular clouds. The isomerization and dissociation channels for each of the three collision complexes are characterized by utilizing the unrestricted B3LYP/6-311...

A chemical reaction model, suitable for use in the Direct Simulation Monte Carlo (DSMC) method, is developed to simulate hypervelocity collisions of an important reaction in atmospheric-jet interactions O(3P)+HCl(1Σ ) OH(2Π)+Cl(2P). The model utilizes the Quasi-Classical Trajectory (QCT) method with two potential energy surfaces (PES), new benchmark triple A and A surfaces and London-Eyring-Pol...

Locusts possess an identified neuron, the descending contralateral movement detector (DCMD), conveying visual information about impending collision from the brain to thoracic motor centers. We built a telemetry system to simultaneously record, in freely behaving animals, the activity of the DCMD and of motoneurons involved in jump execution. Cocontraction of antagonistic leg muscles, a required...

Rate control algorithms for commercial 802.11 devices strongly rely on packet losses for their adaptation. As a result, they give poor performance in dense networks because they are not able to distinguish packet losses related to channel error from packet losses due to collision. In this paper, we evaluate automatic rate adaptation algorithms in IEEE 802.11 dense networks. A certain number of ...

In this paper, we report our progress towards the realization of a continuous guided atomic beam in the degenerate regime. So far, we have coupled into a magnetic guide a flux of a few 10 atoms/s at 60 cm/s with a propagation in the guide over more than 2 meters. At this stage, the collision rate is not high enough to start an efficient forced evaporative cooling. Here we describe a new approac...