Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Impulsive motion

But do all such automatisms constitute—or denote—motives Impulsive motion, yes. But psychological motive. I m not so sure. Now I need to get back to my confession. [Pg.171]

In the pulsed molecular beam studies, the results were used to calculate an impact parameter for the photodissociation process. From these impact parameters it was concluded that the recoiling CN fragment did not take the lowest energy path when it was departing from the halogen atom. Rather, because of strong impulsive motion, the trajectory that the CN rsdical... [Pg.48]

K. Stewartson, On the impulsive motion of a flat plate in a viscous fluid, Q. J. Mech. App. Math. [Pg.755]

No special equilibrium between activated complexes and reactants is assumed. It is supposed however, that within the space between qi and qi+Aqi, q2 and q2+Aq2, configurations (activated complexes) have impulses (motions) between pi and pi+Api,p2 and P2+AP2 respectively. These configurations are computed in accordance with Maxwell-Boltzmann distribution. Recall from the gas laws that an energy profile for molecules can be describe by the Maxwell-Boltzman distribution diagram (Figure 3.3). As the temperature goes up, the population of molecules with more energy also increases. [Pg.74]

Upright cylindrical steel tanks (non-base-isolated) supported directly on the grotmd or on the foundation may be designed with a behavior factor q that represents a quasi-elastic behavior, i.e., q < 1.5. More specifically, a value of = 1 is recommended for the convective motion where negligible dissipation of energy occurs, whereas a value of = 1.5 (quasi-elastic behavior) is recommended for the impulsive motion. [Pg.1342]

The relatively low values of q for the impulsive motion are justified by the unstable nature of shell buckling primary mode of failure. This philosophy is adopted by European Standard EN 1998-4 (European Committee for Standardization 2006b). According to this standard, values of behavior factor greater than 1.5 for the impulsive motion can be used (up to 2.5) in special cases when the tank or its foundation is appropriately designed to allow uplift and the localization of deformations in the shell wall, the bottom plate or their intersection does not cause failure. [Pg.1342]

Impulsive Motion and Pressure The impulsive motion can be expressed in terms of the impulsive acceleration of the liquid storage tank, M/(r), which can be calculated from the following linear oscillator equation ... [Pg.1345]

An alternative procedure to account for soil flexibility has been suggested by Priestley et al. (1986). The procedure suggests the modification of the frequency and the damping of the impulsive motion, based on the work of... [Pg.1355]

Ruhman S, Joly A G and Nelson K A 1987 Time-resolved observations of coherent molecular vibrational motion and the general occurrence of impulsive stimulated scattering J. Chem. Phys. 86 6563-5... [Pg.1230]

The application in [24] is to celestial mechanics, in which the reduced problem for consists of the Keplerian motion of planets around the sun and in which the impulses account for interplanetary interactions. Application to MD is explored in [14]. It is not easy to find a reduced problem that can be integrated analytically however. The choice /f = 0 is always possible and this yields the simple but effective leapfrog/Stormer/Verlet method, whose use according to [22] dates back to at least 1793 [5]. This connection should allay fears concerning the quality of an approximation using Dirac delta functions. [Pg.321]

Piezoelecttic impulse ink-jet printers ate especially sensitive to bubbles in the ink. A bubble in the firing chamber absorbs some of the comptessional force from the flexing of the chamber wall and reduces drop volume and drop velocity, thereby affecting print quaHty. Because of the limited range of motion of the crystal, bubbles ate not readily ejected, and the loss of print quaHty owing to their presence is persistent. [Pg.53]

Typically, in order for motion to occur, several muscle sets must work together to perform even the simplest movements. The bicep is a two-muscle set the tricep is a three-muscle set. Each set works in tandem. Within each muscle group, muscle fibers obey the aU. or none principle, ie, aU. muscle fibers contract or none contract. Therefore, if the muscle fibers of a muscle group are stimulated enough by nerve impulses to contract, they contract to the maximum. [Pg.186]

Mechanical Impulse The principle of mechanical impulse when applied to fluids is usually combined with one of the other means of imparting motion. As mentioned earher, this is the case in axial-flow compressors and pumps. The turbine or regenerative-type pump is another device which functions partially oy mechanical impulse. [Pg.900]

An alternative method, proposed by Andersen [23], shows that the coupling to the heat bath is represented by stochastic impulsive forces that act occasionally on randomly selected particles. Between stochastic collisions, the system evolves at constant energy according to the normal Newtonian laws of motion. The stochastic collisions ensure that all accessible constant-energy shells are visited according to their Boltzmann weight and therefore yield a canonical ensemble. [Pg.58]

Some initial impulse unbalance is often required to start the whirl motion. Newkirk has suggested that the effect is caused by interfaces of joints in a rotor (shrink fits) rather than defects in rotor material. This type of whirl phenomenon occurs only at rotational speeds above the first critical. The phenomenon may disappear and then reappear at a higher speed. Some success has been achieved in reducing this type of whirl by reducing the number of separate parts, restricting the shrink fits, and providing some lockup of assembled elements. [Pg.207]

As the external pressure on the chest wall becomes larger than its internal pressure during the passage of a blast wave, the chest wall moves inward, thus causing injury. Because the inward motion takes time, the duration of the blast wave is important. Results of animal tests indicate that overpressure is only important for long durations, and impulse is important for relatively short durations (White et al. 1971). [Pg.352]

Theoretically, the first type ot propulsion, where the interaction is with a relatively immovable object, is the most energy efficient. In the absence of friction, it is theoretically possible to convert 100 percent of the available energy into kinetic energy, the energy of motion. This is because the more massive immovable object takes away a very small amount of kinetic energy even though it shares equally (but oppositely) in the impulse or change of momentum. [Pg.967]

The foregoing discussion of impulse and momentum applies only when no change in rotational motion is involved. There is an analogous set of equations for angular impulse and impulse momentum. The angular momentum about an axis through the center of mass is defined as... [Pg.165]

Impulses from the vestibular apparatus in the labyrinth are conducted via the vestibular nucleus and cerebellum to the vomiting centre. Abnormal stimulation of the vestibular apparatus is involved in motion sickness and emesis, associated with Menieres disease. [Pg.459]

A difference between these two concepts can be illustrated in many ways. Consider, for example, a mathematical pendulum in this case the old concept of trajectories around a center holds. On the other hand, in the case of a wound clock at standstill, clearly it is immaterial whether the starting impulse is small or large (as long as it is sufficient for starting, the ultimate motion will be exactly the same). Electron tube circuits and other self-excited devices exhibit similar features their ultimate motion depends on the differential equation itself and not on the initial conditions. [Pg.330]

The purpose of this section is to describe recent achievements in time-resolved X-ray diffraction from liquids. Keeping the scope of the present chapter in mind, neither X-ray diffraction from solids nor X-ray absorption will be discussed. The majority of experiments realized up to now were performed using optical excitation, although some recent attempts using infrared excitation were also reported. The main topics that have been studied are (1) visualization of atomic motions during a chemical reaction, (2) structure of reaction intermediates in a complex reaction sequence, (3) heat propagation in impulsively heated liquids, and (4) chemical hydrodynamics of nanoparticle suspensions. We hope that the actual state-of-the-art will be illustrated in this way. [Pg.274]

A light pulse of a center frequency Q impinges on an interface. Raman-active modes of nuclear motion are coherently excited via impulsive stimulated Raman scattering, when the time width of the pulse is shorter than the period of the vibration. The ultrashort light pulse has a finite frequency width related to the Fourier transformation of the time width, according to the energy-time uncertainty relation. [Pg.104]


See other pages where Impulsive motion is mentioned: [Pg.259]    [Pg.133]    [Pg.584]    [Pg.242]    [Pg.1344]    [Pg.1346]    [Pg.259]    [Pg.133]    [Pg.584]    [Pg.242]    [Pg.1344]    [Pg.1346]    [Pg.62]    [Pg.1981]    [Pg.3006]    [Pg.3007]    [Pg.499]    [Pg.186]    [Pg.65]    [Pg.534]    [Pg.1069]    [Pg.99]    [Pg.310]    [Pg.130]    [Pg.185]    [Pg.191]    [Pg.494]    [Pg.902]    [Pg.148]    [Pg.427]    [Pg.287]    [Pg.487]   
See also in sourсe #XX -- [ Pg.98 , Pg.286 ]




SEARCH



Gas Motion Under the Action of Short-Duration Pressure (Impulse)

Impulse

Impulsive

Impulsiveness

© 2024 chempedia.info