Definition Of Time Delay Research Articles

The temporal response of inorganic temperature-sensitive phosphor films with different layer thickness and composition

The temperature-sensitive paint (TSP), one of the temperature measurement techniques, is useful to evaluate temperature from a cryogenic temperature to a high temperature over 1000°C. An inorganic phosphor TSP was painted on a micro scale indium tin oxide (ITO) heater on a slide glass substrate. The temporal response of TSP to a short heating pulse from the micro-scale heater was estimated by using experimental data and numerical simulation. Measuring the temporal delay using the ITO heater with a micro-scale width and the TSP with a micro-scale thickness necessarily requires data acquisition with high temporal and spatial resolution. In this study, an extremely high spatio-temporal resolution, a temporal resolution of 200 kHz and a spatial resolution of 1.05 μm/pixel, was achieved by using a high-speed camera. We assume that the tendency of temperature at bottom of the TSP which contacts with the ITO is the same as the tendency of the current signal applied to the ITO, and the tendency of surface temperature of the TSP reversely follows the tendency of the phosphorescence signal due to the thermal quenching effect. The time delay was defined as the time difference between the time when the current signal becomes maximum and the time when the phosphorescence signal becomes minimum. Based on the definition of the time delay, the time delay was successfully calculated from the experimental data. The shortest time delay is 30.86 μs which is sufficient to visualize highly dynamic phenomena such as boiling flow. The current signal was employed as a boundary condition for numerical simulation of the one-dimensional heat conduction equation, and the time delay was calculated numerically based on the definition of time delay. The experimentally obtained time delay was compared to the numerically calculated time delay. The results showed that experimentally obtained time delay is longer than expected. Several factors explain the reason why the experimental results are different from expected. The quantitative evaluation of time delay of the fast response TSP for a high temperature measurement was successfully implemented, and the results will play an important role as a first step in understanding the thermo-physical properties of the TSP.

Additive Effects of Road Intersection-Specific Volume-delay Functions

Describing the relationship between vehicle volume and travel time delay on road sections consisting multiple intersections in the context of junction quantity is favorable to extend the advantage of intersection-specific volume-delay functions. This paper demonstrates a microsimulation method combined with a non-linear function fitting algorithm to determine unbiased delay function parameters and inspect the eect of junction number on time delays. Results are bifold: first the distance between intersections deemed irrelevant regarding delay function shape, second the implicit scaling property of homogenous junction chains is revealed. Consequently the definition of time delay on uniform intersection chains can be determined by a sole parameter set for the volume-delay function and the addition of a single scaling variable.

Time delay in quantum coherence and tunneling

The problem of time delay in quantum mechanics and its relation to the classical concept of traversal time is studied. For a monochromatic wave, in one dimension, it is shown that the time delay is proportional to a linear combination of the derivatives of the phases of the transmission and reflection coefficients with respect to the frequency. In particular it is shown that the definition of time delay for quantum coherence given in terms of the periods of oscillations of a wave packet between the two wells, in the proper limit, agrees with the corresponding definition in tunneling.

Time-delay analysis of zero-angular-momentum resonances

Time delay in collisions is analyzed when zero-angular-momentum resonances are present. It is shown that very large delay comes from an orbiting wave. This is reflected in rapid change with energy of the phase of the $S$-matrix residue. In addition, we show the proper definition of time delay in terms of the scattering amplitude.

On the Hilbert-space approach to classical time delay

Within the context of the Hilbert-space approach to classical mechanics, a definition of time delay for classical scattering systems is given. Its relation with the S-matrix is discussed by close analogy with the quantum case.

Similarity of Wigner's delay time to the virial theorem for scattering by a central field

The quantum-mechanical virial theorem for scattering of a particle by a central force is expressed in terms of Wigner's definition of time delay, tau = 2h deta/dE. By using semiclassical approximations, the quantum-mechanical virial is transformed into the classical virial and tau becomes exactly the classical delay time.

Scattering theory with dissipative interactions and time delay

The general formalism of scattering theory with dissipative interactions is presented from the time-dependent viewpoint. A definition of time delay is proposed in this framework, generalizing that given for simple scattering systems. The time delay is expressed by a formula which reduces to that of Eisenbud and Wigner when there is no absorption.

Stationary approach to the definition of time delay in the scattering process

A new stationary approach to the problem of the time of scattering is proposed. The correspondence between this approach and the usual one is established.