We report the in situ formation of an ordered equilibrium decagonal Al-Pd-Mn quasicrystal overlayer on the fivefold symmetric surface of an icosahedral Al-Pd-Mn monograin. The decagonal structure of the epilayer is evidenced by x-ray photoelectron diffraction, low-energy electron diffraction, and electron backscatter diffraction. This overlayer is also characterized by a reduced density of stat...

Sound propagation in urban and indoor environments often involves diffraction at corners, finite objects openings, resulting perceptually relevant frequency-dependent attenuation. Geometrical acoustics (GA) have become a de-facto standard for the prediction simulation of sound real-time virtual acoustics, including effects edge diffraction. However, methods to account assume infinite edges, suc...

This paper represents a technique for finding optimal paths with multiple indexes in a graph. Up to the present time, all optimal paths have been determined upon one index, say, distance for which an evaluation method exists. In this paper firstly we define multiple indexes for each edge in such a way that anyone can treat the factor for assigning an optimal path. Here, we use Data Envelopment ...

We use dynamical low-energy electron diffraction ~LEED! to determine the surface structure of a-Al2O3(0001). Sapphire surfaces are prepared in three different ways, and the diffraction results are analyzed using an exhaustive search of possible models. For all sample processing conditions, the clearly favored structure has a single Al layer termination and a large first interlayer contraction. ...

In order for auralization to better replicate the binaural listening experience in a space, acoustic scattering in the room impulse response (RIR) must be more accurately calculated. Three models are discussed and used in room computations and auralizations: Lambert scattering, edge-diffraction models based on the Biot-Tolstoy-Medwin technique, and boss models for protuberances on reflecting su...

Local structure of the Cu02 plane in Bi2Sr2CaCu208+8 (Bi2212) superconductor has been solved by joint Cu K-edge extended X-ray absorption fine structure (EXAFS) and anomalous X-ray diffraction. The Cu-0 pair distribution function (PDF) has been measured by EXAFS and diffraction. The displacement of the Cu ions along the c-axis shows largest amplitude and anharmonic character. The results show f...

Coherent backlight is an essential component for holographic displays. In this paper, a compact design of edge-lit coherent backlight featuring two holographic optical elements for two-dimensional beam expansion is presented. Its diffraction efficiency is numerically studied using the coupled-wave theory. In experiments, the diffraction efficiency is measured as 4.3% and the feasibility of this...