Scattering property measurement

The acoustic quality in a room can be affected by the scattering of sound by the walls and objects inside. The scattering coefficient and the diffusion coefficient are two common measures to describe the scattering produced by a surface. The random incidence scattering coefficient of surfaces caused by surface roughness is measured in a 

1 Measurement of the random incidence scattering coefficient in a reverberation room 

The fu-st part of ISO 17497 specifies a method of measuring the random incidence scattering coefficient of surfaces caused by surface roughness (ISO, 17497-1, 2004). The measurements are made in a reverberation room, either in full scale or on a scale model. The measurement results can be used to desalbe how much the sound reflection from a surface deviates from a specular reflection. The results obtained can be used for comparison purposes and for design calculations with respect to room acoustics and noise control. The method is not intended for characterizing the spatial uniformity of the scattering from a surface. 

The scattering coefficient can be calculated by one minus the ratio of the specularly reflected acoustic energy to the total reflected acoustic energy  

The absorption coefficient and the specular absorption coefficient can be measured in a reverberation room. 

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Fig. 11 The scattering properties of a five branches - four electrodes molecular bridge, (a) Detailed atomic structure of the molecule. A central perylene branch was included to mimic an internal measurement branch, (b) EHMO-ESQC calculated T12(E) transmission coefficient (plain) and predicted T12(E) transmission coefficient (dashed), applying the intramolecular circuit rules discussed for the four molecular fragments given in Fig. 12. The dashed (dotted) line is the Ti2(E) variation for the single molecular branch, as presented in the inset, to show the origin of the destructive interference...

Total reflection x-ray fluorescence (TXRF) has become very popular for the conduct of microanalysis and trace elemental analysis [77-79]. TXRF relies on scatter properties near and below the Bragg angle to reduce background interference, and to improve limits of detection that can amount to an order of magnitude or moreover more traditional XRF measurements. As illustrated in Fig. 7.18, if x-rays are directed at a smooth surface at a very small angle, virtually all of the radiation will be reflected at an equally small angle. However, a few x-rays will excite atoms immediately at the surface, and those atoms will emit their characteristic radiation in all directions. One obtains very clean... 

Abstract Flow cytometry is a technique for rapidly examining multiple characteristics of individual cells, by recording fluorescence signals emitted from cell-associated reporter molecules, and measuring cellular light scattering properties. This chapter introduces the principles and practice of flow cytometry, and reviews examples from the literature that highlight applications of this experimental tool in the neurosciences. The chapter concludes with protocols for three basic procedures that illustrate some practical aspects of analytical flow cytometry. 

Pinnick R. G., J. M. Rosen, and D. J. Hoffmann, 1973. Measured light-scattering properties of individual aerosol particles compared to Mie scattering theory, Appl. Opt., 12, 37-41. 

This material also has a porous structure by virtue of its being made by etching a phase-separated borosilicate glass. PS chains have also been introduced into the pores of this type of glass [146], but the only results to date involve mechanical property measurements, and scattering investigations. 

Equation (16.1) is an approximation it assumes that the measured spectral contribution from Pa is independent of the overall composition of the sample. In reality, the bulk absorption and scattering properties of different samples will cause variations in how much Raman signal is collected. In the case of urine and blood serum specimens, the variation is often negligible. For whole blood and turbid tissue specimens, the influence of bulk optical properties is more important. Methods of correcting for their effects and returning to the simple linearity assumptions of (16.1) are mentioned briefly in the next section. 

Progress in nanotechnology also depends critically on new developments in microscopy [42-45]. Compared to other investigation methods that help to explore the relation between the molecular structure and macroscopic properties, microscopy gives the most direct information. Particularly, in the case of disordered or aperiodic structures, visualisation of the structure is often more useful than indirect measurement and interpretation of its scattering properties. In practice, the utilisation and value of microscopes depends on their spatial resolution, the contrast and the imaging conditions. 

The physical and chemical properties of the measurement site greatly influence accuracy of noninvasive clinical measurements. Noteworthy physical parameters include thickness, scattering properties, and temperature of the tissue at the measurement site. Chemical issues center on the molecular makeup of the tissue (water, protein, fats, amino acids, glycolytic structures, etc.) and the heterogeneous distribution of these chemical components throughout the measurement site. 

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