The interaction of an acoustic wave with two joined flat plates results in a diffracted acoustic wave emanating from the junction. The plates are assumed, for simplicity, to have different masses but no stiffness, and the exact solution of the two-dimensional diffraction problem is derived as a Fourier integral. The diffraction coefficient for a plane acoustic wave is found to depend in a simpl...

Diffraction gratings are elementary tools for much of optics and spectroscopy. Here, at microwave frequencies, we provide a new perspective on these fundamental structures. A transmission diffraction grating is presented that has diffracted beams emanating from one surface only. It can thus function either as a transmission grating with no reflected orders (other than zero) or, in the reverse c...

Using electron beam lithography we have fabricated arrays of metallic and non-metallic planar chiral structures on silicon substrates, and observed the pronounced effects of their chirality on the polarization states of the diffracted light in the transmission regime. Significant differences in polarization properties were observed between metallic and polymer structures, most notably in the de...

The xeroderma pigmentosa group F protein (XPF) is a founding member of a family of 3'-flap endonucleases that play an essential role in nucleotide-excision repair, DNA replication and recombination. The XPF gene has been cloned from Aeropyrum pernix, encoding a 254-residue protein (apXPF). Recombinant protein was produced in Escherichia coli and purified by three chromatographic steps. Three di...

A century has passed since Bragg solved the first atomic structure using diffraction. As with this first structure, all atomic structures to date have been deduced from the measurement of many diffracted intensities using iterative and statistical methods. We show that centrosymmetric atomic structures can be determined without the need to measure or even record a diffracted intensity. Instead,...

The linearized theory of water waves is used to examine the diffraction of an incident wave by a permeable breakwater that consists of a number of distinct elements. Under the assumption that the wavelength is much greater than the thickness, each element is replaced by a thin structure and the permeability is modeled by a suitable boundary condition applied on its surface. The diffracted wave ...

Scalar diffraction theory is frequently considered inadequate for predicting diffraction efficiencies for grating applications where lambda/d>0.1. It has also been stated that scalar theory imposes energy upon the evanescent diffracted orders. These notions, as well as several other common misconceptions, are driven more by an unnecessary paraxial approximation in the traditional Fourier treatm...

The diffraction of SH waves by a finite plane crack is studied. The classical Sommerfeld solution for a semi-infinite straight reflecting screen is used as a building block to calculate the diffracted field generated by a finite crack. The solution is derived from the analysis of the behaviour of diffracted waves. These waves, which are first generated at the edges of the crack, travel along th...

Measurements of the thermal diffusivity thin and bulk indium-doped lead telluride have been taken using a modified method dynamic gratings. Thermal gratings were recorded by 20 ns pulsed laser radiation at wave length 532 nm. Dynamic 635 nm continuous radiation. The analysis diffraction signal kinetics made it possible to determine life-time in investigated samples. It is shown that use an addi...