We simulate the interference patterns of solar systems, incorporating an Estrella and two Tierras, as detected by a rotational shearing interferometer, to compare with laboratory setup. Three rays are propagated to represent each wavefront in the interferometer, using the exact ray tracing technique. Then, the phase, with which light beams are incident into the detection plane is used to calculate the orientation of the incident wavefront. Finally, all the incident wavefronts are summed together to obtain the resulting interference pattern.
We examine the mechanisms of pulse propagation inside tissue to determine the spectral intervals wherein the pulse might propagate to an occlusion and reflect from its boundary. We derive analytical expression, showing that the depth of occlusion may be determined upon measuring the time during which the input temperature pulse travels to the inclusion, is reflected from it, and returns to the front of the skin surface. Additionally, we derive the speed of pulse propagation from diffusivity and material time constants. These quantities are calculated from the published tissue parameters; they could also be calibrated for specific classes of the biological samples. For breast tissue monitoring, we propose to use near IR laser pulses.
The current philosophy of designing intelligent buildings emphasizes the use of materials whose performance is compatible with thermal environment that changes daily and seasonally. Ideally, engineering designs should incorporate features to reflect as much energy as feasible and store excess thermal energy. This may be for usage during periods when thermal energy is needed for heating. We show that current construction design methods may be improved for energy efficiency, by incorporating an attic as an transitional space for energy storage during summer, and by employing roof materials with high reflectivity in the visible and in the near IR (up to about 1.9 μm). Thus, traditional red or pink brick roofs, potentially glazed or covered with low reflectivity coating, would likely remain (become again) the preferred construction material.
The influence of thermal radiation on wall surface temperatures in a typical stationary conjugate heat transfer problem is studied. Free convective heat transfer, accounted for phenomenologically through the introduction of heat transfer coefficients, is supplemented by surface thermal radiation. The calculations clearly indicate that surface radiation can change significantly the surface temperatures which are, in general, reduced with increasing emissivities of the walls. In particular, in the case of small convection heat transfer coefficients, small thermal transmittances of the walls and high values of emissivities, the temperature difference across the temperature boundary layers adjacent to the walls could even be reversed.
KEYWORDS: Photons, Interferometry, Particles, System on a chip, Americium, Optical testing, Temperature sensors, Sensors, Absorption, Maxwell's equations
Any device built to measure the radiation power density, such as photocells, photomultipliers, takes relies on the
absorption of radiation by matter. In this presentation, we are interested in the description of the incident radiation, in
particular in how to express the number of photons and their fluctuations for different spectral compositions of light,
such as laser or chaotic light. We investigate the temperature dependence of the photon number and the corresponding
radiation power density, as well as their fluctuations. In case of coherent states such as in laser light, only one term
appears in the expression for the energy fluctuations, characteristic also for particles. In case of chaotic light, there are
two terms in the expression for the energy fluctuations of which one is characteristic of particles and the other of waves.
This is a manifestation of the dual particle-wave nature of light.
The presence of ions in LC displays influences the performance of the displays through their transport driven by the applied voltage, especially at low driving frequencies. The ion transport causes important degradation of the electro-optical characteristics of displays. We present a model of the ion transport mechanisms taking place within a LC display. Various ionic effects with strongly different time constants are considered and two main competing driving potential screening effects are assumed, caused by free ions in LC layer and free ions in alignment layers, respectively. The role of insulation layers separating ions in LC from the electrodes is considered which can switch a cell between different regimes (cell decay and charging-up of the cell); also the asymmetry of the cell and the problem of balancing the LC and alignment layers ions are addressed. For various ion concentrations, the transmittance of the LC cell is calculated and compared with experimental results.
The structure and dynamic properties of achiral polar smectic liquid crystals formed by bow shaped molecules is considered and described by two two-dimensional order parameters, &vec;P and &vec;ξ. The first, polarization order parameter, gives the average projection of the arrow vectors on the smectic layer planes. The second, tilt order parameter, gives the average magnitude and direction of the tilt. To study the possible liquid crystal structures and their properties, a discrete phenomenological model taking into account the competing interactions between the nearest-neighbor smectic layers is used. The free energy of the system is expressed as a sum over smectic layers with terms modeling the appropriate intralayer and interlayer interactions and written only in terms of the arrow and the string order parameters. The free energy is then minimized in order to obtain stable structures and deduce their optical properties.
There exist solutions for the case of strong coupling between the polarization and the tilt order parameters arising from attractive intralayer van der Waals and from steric interactions. In this contribution, we focus our attention to the case of weak coupling between the two order parameters and investigate possible structures and related optical properties of the system.
We develop an analytical estimate for the error that arises when approximating the generalized Planck's equation with a truncated series of N-terms. We present an analytical expression to evaluate the number of terms required to achieve specific accuracy. The results are applied to evaluation of the integral of the generalized Planck's equation over a wavelength interval.
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