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Wall pressure and shear stress spectra from direct numerical simulations of turbulent plane channel flow are presented in this paper. Simulations have been carried out at a series of Reynolds numbers up to [Re.sub.[tau]] = 1440, which corresponds to Re = 6.92 x [10.sup.4] based on channel width and centerline velocity. Single-point and two-point statistics for velocity, pressure, and their derivatives have been collected, including velocity moments up to fourth order. ([section]) The results have been used to study the Reynolds number dependence of wall pressure and shear stress spectra. It is found that the point spectrum of wall pressure collapses for [Re.sub.[tau]] [greater than or equal to] 360 under a mixed scaling for frequencies lower than the peak frequency of the frequency-weighted spectrum, and under viscous scaling for frequencies higher than the peak. Point spectra of wall shear stress components are found to collapse for [Re.sub.[[tau] [greater than or equal to] 360 under viscous scaling. The normalized mean square wall pressure increases linearly with the logarithm of Reynolds number. The rms wall shear stresses also increase with Reynolds number over the present range, but suggest some leveling off at high Reynolds number.

White-beam synchrotron X-ray topographic studies of twin structures in NdP5O14 single crystals reveals that the a-type twins along the a-axis are displaced. The displacement measurement indicates presence of monoclinic distortion associated with unit cell parameters. The twin structure of NdP5O14 is obtained from the fine-beam Laue diffraction pattern of the compound.

Synchrotron radiation white beam X-ray topography facilitated the observation of growth bands and growth sector boundaries in Er-doped LaP5O14 (LPP) ferroelastic crystal and a type of abnormal boundary. Local displacements of La ions, as a result of local stress concentration along the (001) direction, caused abnormal boundary formation. The growth band and growth sector boundaries are LPP's primary defects.

This work reports on the improved performance of planar GaAs and InGaAs Schottky diodes fabricated by rare element Pr related oxides Pr2O3-added liquid phase epitaxy. We verify that impurity concentrations are suppressed by two orders, and that electron mobility is significantly enhanced. With Pr2O3 added, the cutoff frequency of Schottky diodes increases in planar InGaAs but decreases in planar GaAs, because of higher contact resistance. [Copyright &y& Elsevier]

Examines the distribution of an inverted ferroelectric domains on the periodically poled KTA single crystal. Use of an X-ray diffraction setup; Availability of a coherent beams at the third-generation synchrotron source; Phase difference of the diffracted waves.

Investigates synchrotron topography used in the characterization of Fe-doped flux-grown KTN with composition on the margin of paraelectric phase. Appearance of growth bands in flux-grown KTN; Impact of the occurrence of the partial transition on the interior of KTN crystals; Analysis on the occurrence and growth characteristics of KTN.

Examines the characterization of periodically domain inverted KTiOPO[sub 4] crystal by a multiple reflection x-ray topography. Discussion of the origin of striation contrast formation and the mechanism of KTIOPO[sub 4] domain; Application of multi crystal multiple reflection high resolution x-ray topography; Disclosure of striation contrast.

Examines the ferroelastic phase transition in erbium-doped lanthanum pentaphosphate crystals with synchrotron radiation. Characteristics of a classical second-order transition on topographs; Fluctuations of the domain wall numbers with temperature; Link of the domain wall fluctuation with order parameter critical function.