Scanning Acoustic Microscopy in Materials Characterization

The scanning acoustic microscopy is a powerful tool for subsurface imaging and therefore fault detection in coated parts. In this paper several methods are established to reveal the imaging of hidden structures. First efforts were made to find out the information depth due to the various distances between lens and surface of the object. By means of a specially developed test specimen it was possible to estimate the penetration depth for monitoring structural details. The indepth analysis of layered composites is considered by the determination of the V(z)-characteristics. Furthermore the gain of image processing by means of Fourier transformed patterns and simultaneous filtering is shown by a typical example

Application of ecological momentary assessment in stress-related diseases

Many physical diseases have been reported to be associated with psychosocial factors. In these diseases, assessment relies mainly on subjective symptoms in natural settings. Therefore, it is important to assess symptoms and/or relationships between psychosocial factors and symptoms in natural settings. Symptoms are usually assessed by self-report when patients visit their doctors. However, self-report by recall has an intrinsic problem; "recall bias". Recently, ecological momentary assessment (EMA) has been proposed as a reliable method to assess and record events and subjective symptoms as well as physiological and behavioral variables in natural settings. Although EMA is a useful method to assess stress-related diseases, it has not been fully acknowledged, especially by clinicians. Therefore, the present brief review introduces the application and future direction of EMA for the assessment and intervention for stress-related diseases

Direct measurement of surface acoustic wave velocities and accuracy enhancement by wavelet transform

The aim of this work is to show that the wavelet transform as an image processing technique has the capability to improve quantitative measurements of surface acoustic wave (SAW) velocities. An outline of the basic properties of the wavelet transform and its advantages is given. We apply the wavelet transform to a recently developed measurement technique for the determination of SAW velocities. This technique is based on a modified scanning acoustic microscope (SAM) and can be thought as directly imaging SAWs that propagate on the surface of a solid. Results for the SAW velocity of silicon single crystals are presented

Fourier optics analysis of spherical-particles image-formation in reflection acoustic microscopy

The process of contrast formation for spherical particles in reflection scanning acoustic microscopes is investigated. It is shown that in reflection acoustic microscopes the image formation of spherical particles is quantitatively well described by the Fourier optics methods. The center image of a sphere shows the Fourier transformation of the squared pupil function. The images in the top are similar to the OTF of the confocal microscopical system. The contrast of the image obtained in a middle position exhibits the pupil function in square

Examination of the two-dimensional pupil function in coherent scanning microscopes using spherical particles.

The determination of the modulus of the pupil function in reflection acoustic and optical microscopy with the help of spherical particles is demonstrated. The theoretical examination shows that this method can give good results if the pupil function drops smoothly towards the edge. For a pupil with a sharp edge this technique can give the accurate pupil function only by imaging large spheres. The dependence of the accuracy of the method on the size of the spherical particle is analyzed. Numerical and experimental results obtained for the confocal scanning optical microscope and the scanning acoustic microscope are examined

Imaging of spheres with the confocal scanning optical microscope.

The scalar theory of image formation for a strongly spherical object in ref lection confocal optical microscopy is considered. The image contrast is derived from the far-field scattering amplitude. Experimentally obtained images of the sphere are seen to be in good agreement with the theoretical prediction

A Review and Analysis of Remote Sensing Capability for Air Quality Measurements as a Potential Decision Support Tool Conducted by the NASA DEVELOP Program

This project focused on a comprehensive utilization of air quality model products as decision support tools (DST) needed for public health applications. A review of past and future air quality measurement methods and their uncertainty, along with the relationship of air quality to national and global public health, is vital. This project described current and future NASA satellite remote sensing and ground sensing capabilities and the potential for using these sensors to enhance the prediction, prevention, and control of public health effects that result from poor air quality. The qualitative uncertainty of current satellite remotely sensed air quality, the ground-based remotely sensed air quality, the air quality/public health model, and the decision making process is evaluated in this study. Current peer-reviewed literature suggests that remotely sensed air quality parameters correlate well with ground-based sensor data. A satellite remote-sensed and ground-sensed data complement is needed to enhance the models/tools used by policy makers for the protection of national and global public health communitie