Measuring Power of Earth Disturbances Using Radio Wave Phase Imager.

Numerous studies have investigated ionospheric waves, also known as ionospheric disturbances. These disturbances exhibit complex wave patterns similar to those produced by solar, geomagnetic, and meteorological disturbances and human activities within the Earth's atmosphere. The radio wave phase imager described herein measures the power of the ionospheric waves using their phase shift seen in phase images produced by the Long Wavelength Array (LWA) at the New Mexico Observatory, a high-resolution radio camera.

Diffracted beam interferometry - Differential phase contrast image of an amorphous thin film material.

Differential phase contrast based on diffracted beam interferometry is used to explain the good phase contrast found of an amorphous thin film material deposited on the surface of a gold (Au) crystal substrate. An electron biprism is used to interfere two symmetrically diffracted beams generated by the Au crystal substrate that carried the phase of the amorphous material specimen. Bragg diffraction from the Au crystal substrate is used to explain why the phase of the amorphous thin film material is so well phase imaged.

Phase imaging dislocations using diffracted beam interferometry.

A phase imaging method that measures the phase shift existing at a dislocation's core is described. The method uses the interference of two symmetrically diffracted beams on the optic axis by means of an electron biprism. Each diffracted beam carries half the phase of the dislocation core.

A high angle scattering, stable amorphous metal TEM specimen for measuring the information envelop of electron microscopes.

An amorphous metal (a-metal) TEM specimen suitable for measuring the information envelop of (S)TEM electron microscopes is presented. Its features include producing high angle electron scattering intensities and having good structural stability compared with commonly used specimens of amorphous carbon (a-C) and Au islands supported on a-C substrate.

Acid-treated Fe-doped TiO as a high performance photocatalyst used for degradation of phenol under visible light irradiation.

The photocatalytic activity of Fe-doped TiO nanoparticles is significantly increased by an acid-treatment process. The photocatalyst nanoparticles were prepared using sol-gel method with 0.5 mol% ratio of Fe:Ti in acidic pH of 3.

Self-interference of split HOLZ line (SIS-HOLZ) for z-dependent atomic displacement measurement: Theoretical discussion.

A characteristic of the majority of semiconductors is the presence of lattice strain varying with the nanometer scale. Strain originates from the lattice mismatch between layers of different composition deposited during epitaxial growth. Strain can increase the mobility of the charge carriers by the band gap reduction.

Determination of three-dimensional strain state in crystals using self-interfered split HOLZ lines.

An experimental method to measure the strain through the thickness of a crystal is demonstrated. This enables the full three-dimensional stress-strain state of a crystal at the nanoscale to be determined taking the current practice from two-dimensional strain state determination. Knowing the 3D strain state is desired by crystal growers in order to improve their crystal's quality.

Coherence of k-space electrons: application to TDS electrons by DBI.

Methods of controlled electron interference in k-space on the diffraction plane by means of an electron biprism invented during the Tonomura Electron Wavefront Project are briefly reviewed. The results presented show the partial coherence of self-interfered diffusely scattered electrons, elastically scattered and inelastically scattered, found outside and in between the Bragg diffracted beams often referred to as thermal diffuse scattering (TDS) of electrons. The interference fringes formed in the TDS intensity have been used to calculate a mean displacement of the atom of u ≈ 12 pm in Aluminum in the direction perpendicular to the Bragg planes.

Imaging and diffraction of protein crystallization using TEM.

Structural biology relies on good-quality protein crystals in order for structure determination. Many factors affect the growth process of a protein crystal including the way it nucleates and the types of damage and contamination during its growth. Although the nucleation process and quality of a crystal is vital to structure determination, they are both under-studied areas of research.

Examining protein crystallization using scanning electron microscopy.

Elucidation of protein structure using X-ray crystallography relies on the quality of the crystal. Crystals suffer from many different types of disorder, some of which occur during crystal nucleation and early crystal growth. To date, there are few studies surrounding the quality and nucleation of protein crystals partly due to difficulties surrounding viewing biological samples at high resolution.

Measurements validating the confocal scanning laser holography microscope.

A confocal scanning laser holography (CSLH) microscope that uniquely combines the concepts of confocal microscopy with holography has been validated for making nonintrusive, full three-dimensional (3D) intensity and phase measurements of objects from a single viewpoint of observation without loss of object information. The phase measurements have been used to determine the 3D refractive indices of a point source heated silicone oil. The refractive indices are converted to 3D temperature measurements, which are useful for heat transfer studies.

Coherent electron interference from amorphous TEM specimens.

For the first time, the electron intensity on the diffraction plane from amorphous transmission electron microscope (TEM) specimens has been found to have sufficient coherence to produce fringes in interferograms that were created using a wavefront splitting method of diffracted beam interferometry. The fringes were found to exist from low to high electron-scattering angles. Their spatial frequency depended on the angular overlap of the interfering beams, which was controlled by an electron biprism.

Developing a confocal acoustic holography microscope for non-invasive 3D temperature and composition measurements.

A confocal acoustic holography microscope (CAHM) has been designed, simulated and partially verified experimentally to take holograms for non-invasive, three-dimensional measurements of a specimen's refractive indices from one view point. The designed and simulated prototype CAHM used a frequency of 2.25 MHz and measured sound speed changes of 16 m/s, temperature changes of 5 degrees C and had a spatial resolution of 660 microm.

Electron beam coherence measurements using diffracted beam interferometry/holography.

The intensity and coherence of elastically and inelastically scattered electrons have been studied by the interference of electron-diffracted beams using a method of diffracted beam interferometry/holography (DBI/H). In the interferograms produced, fringes were found to exist from low to high scattering angles. The intensity and coherence of the fringes are useful for understanding the contrast mismatch between experimental and simulated images found in atomic resolution images of crystals produced by transmission electron microscopy (TEM) and annular dark-field (ADF) scanning transmission electron microscopy (STEM).

An algorithm for 3-D refractive index measurement in holographic confocal microscopy.

The principle of holographic confocal microscopy is introduced in this paper. An algorithm is presented to retrieve the phase information from the holograms and calculate the refractive index of the specimen from the phase. It is shown that this algorithm can be applied to a refractive index distribution in which the variation in x and z directions can be separated.