Scanning electron acoustic microscope

Okawai, H., Tanaka, M., Chubachi, N., and Kushibiki, J. (1987). Non-contact simultaneous measurement of thickness and acoustic properties of biological tissue using focused wave in a scanning acoustic microscope. Proc 7th Symp. Ultrasonic Electronics, Kyoto. Jap. J. Appl. Phys. 26 (Suppl. 26-1), 52-4. [164]... 

Small samples were stressed in three-point flexure while being viewed with scanning electron or optical microscopes. The fracture behavior was recorded by video and correlated with acoustic emission measurements. The samples were oriented in the flexure-test fixture with the plane of the cloth plies perpendicular to the force direction therefore, the tensile and compressive stresses are primarily in the plane of the cloth plies where the fibers resist deformation. 

SAW) is performed with a sensitivity in the sub-picometer range. Acoustic waves are generated as well as detected with microprobes in a microscopic hybrid system consisting of a scanning electron microscope (SEM) combined with a scanning force microscope (SFM). 

The acoustic microscope has the software to analyze the image once the scan is completed. Analysis tools include histogram (for percentage of voids), vertical and horizontal profile, zoom, manipulation of color scale, measurements, and multiple scans. The system also has the capability to print either in color or black and white, or to transmit images electronically over the network. 

The laminates of tiK carbon-fiber composite were first characterized by acoustic NDI (C-scan) and optical microscopy to evaluate their quality. Scanning electron microsctqiy (SEM) was used to evaluate laminate quality and nanoparticle distributimi using a Philips XL30 ESEM TMP scanning electron microscope. Mechanical tests fm tiie carbon-fiber composite were selected to measure resin-dominated properties. These tests were transverse four-point flexure with a qian-to-deptii ratio of 32 1 and longitudinal four-point flexure with a qi>an-to-depdi ratio of 16 1 designed to induce mic lane shear failure. Ten qiecimens were tested for each material type and condition. 

Characteristics Figures 33.2 and 33.3 show the appearance and the scanning electron microscope (SEM) image of an aerogel synthesized by the above process, respectively. Density was calculated from the volume and weight. The acoustic velocity was calculated from thicknesses and ultrasonic propagation time (about 500 kHz). 

The standard piece of equi( nent used in AMI is the C-Mode Scanning Acoustic Microscope (C-SAM ). The system is a pulse-echo (reflection type) microscope that generates images by mechanically moving a transducer back and forth, in a raster pattern, over the sample. The source transducer is a focused acoustic lens assembly and is coupled to the sample by fluid medium - usually de-ionized water or some type of inert fluid. The transducer has piezoelecoric properties, which allow it to aa as both a sender and receiver being electronically switched back and forth between transmit and receive modes (Figure 2). 

As a first step, in the present work, the microcellular poroelastic foams under study are considered as rigid and their acoustics described by the JCA model. That is, the mechanical properties are not considered in this initial study. The approach that is taken to characterize the acoustical performance is as follow. First a morphological characterization of the microcellular stracture will be performed using the Scanning Electron Microscope in order to determine average cell (pore) dimensions. Then, basic acoustical measmements (mainly, porosity, flow... 

The classical polarizing light microscope as developed 150 years ago is still the most versatile, least expensive analytical instrument in the hands of an experienced microscopist. Its limitations in terms of resolving power, depth of field, and contrast have been reduced in the last decade, in which we have witnessed a revolution in its evolution. Video microscopy has increased contrast electronically, and thereby revealed structures never before seen. With computer enhancement, unheard of resolutions are possible. There are daily developments in the X-ray, holographic, acoustic, confocal laser scanning, and scanning tunneling micro-... 

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