Three-dimensional recording

The application of holography to plasma interferometry has several advantages 276) accurate alignment and precision optical elements are not required. A complete three-dimensional record of the interference phenomena is obtained and the technique is well suited to record stationary and transient plasmas. Two-wavelength holographic interferometry of partially ionized plasmas has been performed by Jeffries 277). 

Baba, S.A., Inomata, S., Ooya, M., Mogami, Y. and Izumi-Kurotani, A. (1991). Three-dimensional recording and measurement of swimming paths of microorganisms with two synchronized monochrome cameras. Rev. Sci. Instrum. 62, 540-541. 

The only down sides of cooled CCD cameras have been their relatively slow read-out rate (typically 0.5-1.0 million pixels/sec) and their relatively high cost. For most cell biological applications, the slow read-out rate is not a consideration. For example, in most immunofluorescence applications the camera exposure time is longer than the camera read-out time (typical exposure times of 1-10 sec versus read-out times of 1-2 sec). Cooled CCD camera read-out rates have been entirely adequate for our time-resolved, two-component, three-dimensional recordings of the short mitoses of Drosophila early embryos (Paddy et ai, 1996). However, researchers following very rapid cell phenomena in situ. 

Fig.3. The principle of the FIA Gradient scanning technique, allowing a series of spectra to be recorded on a dispersed sample zone (left) S, point of sample injection, and t, time. The three-dimensional recording (right) shows an electrochemical spectrum, that is, a voltammogram of a 0.01 M solution of copper(Il)amine complex being reduced on a mercury electrode. The peak (forming a ridge) is located at a potential (U) at which maximum current intensity (i) is observed due to reduction of Cu(II). Fifty scans (each lasting 2 sec.) were recorded on the tailing section of the dispersed sample zone. ...

Kovacs, L., A. Zimmennann, G. Brockmann, M. Guhring, H. Baurecht et al. (2006). Three-dimensional recording of the human face with a 3D laser scaimer. Journal of Plastic, Reconstructive and Aesthetic Surgery 59 1193-202. 

Figure 41 (a) Read out from photorefractive recording of fhe alphabet E on a plane from bits spaced at 5.6 pm. (b) The same region of the film after the pattern has been erased by UV exposure, (c) after a pattern of alphabet F was written on the previously erased space, (d)-(f) Read outs from three-dimensionally recorded images of alphabets A , B , and C spaced 20 pm axially from each other [97]. The artefacts 1 and 2 in Figures 41(a)-(c) indicate that the data is written at the same area in the film after erasing the previously written data. The images of the three-dimensionally stored data are... 

When all of the ISS spectra are plotted in a three-dimensional manner, such as the z- plot shown in Figure 3, the changes in surface composition with depth are much more obvious. In this figure, each spectrum represents the composition at a different cross section of the total depth sputtered, hence the spectra are plotted at different depths. Note that the spectra are not recorded at identical incremental depths. 

Recently, there has been a growth of interest in the development of in vitro methods for measuring toxic effects of chemicals on the central nervous system. One approach has been to conduct electrophysiological measurements on slices of the hippocampus and other brain tissues (Noraberg 2004, Kohling et al. 2005). An example of this approach is the extracellular recording of evoked potentials from neocortical slices of rodents and humans (Kohling et al. 2005). This method, which employs a three-dimensional microelectrode array, can demonstrate a loss of evoked potential after treatment of brain tissue with the neurotoxin trimethyltin. Apart from the potential of in vitro methods such as this as biomarkers, there is considerable interest in the use of them as alternative methods in the risk assessment of chemicals, a point that will be returned to in Section 16.8. 

In three-dimensional experiments, two different 2D experiments are combined, so three frequency coordinates are involved. In general, the 3D experiment may be made up of the preparation, evolution (mixing periods of the first 2D experiment, combined with the evolution t ), mixing, and detection ( ) periods of the second 2D experiment. The 3D signals are therefore recorded as a function of two variable evolution times, t and <2, and the detection time %. This is illustrated in Fig. 6.1. 

For the analysis, we developed a new method that makes it possible to observe correlated potentials between two trapped particles. The principle is shown in Figure 7.5. From the recorded position fluctuations of individual particles (indicated by the subscripts 1 and 2), histograms are obtained as a function of the three-dimensional position. Since the particle motion is caused by thermal energy, the three-dimensional potential proflle can be determined from the position histogram by a simple logarithmic transformation of the Boltzmarm distribution. Similarly, the... 

The bubble behavior near the boiling crisis is three-dimensional. It is hard to show a three-dimensional view in side-view photography, because the camera is focused only on a lamination of the bubbly flow. Any bubbles behind this lamination will be fussy or even invisible on the photograph, but they can be seen by the naked eye and recorded in sketches as shown in Section 5.2.3. For further visual studies, the details inside bubble layers (such as the bubble layer in the vicinity of the CHF) would be required. Therefore, close-up photography normal and parallel to the heated surf ace is highly recommended. 

Figure 3.4 shows (i) a line spectrum (one-dimensional dispersive spec-trographic record), (ii) a spectrometric record, (iii) an interferogram obtained by a Fourier transform spectrometer, and (iv, v) two- and three-dimensional double dispersive spectra recorded e.g. by Echelle spectrometers. In principle, all forms may be obtained by OES. 

Four polarized ATR spectra can be recorded to characterize the three-dimensional (3D) orientation of a sample, p- and s-polarized spectra are recorded with the sample clamped with its Z- and X-axes sequentially aligned perpendicular to the incidence plane (that is, parallel to the s-polarized electric field). The absorbance measured in these different configurations is related to the anisotropic absorption indices of the sample, kj, as... 

A CCD array collects simultaneously the spectral data emanating from an array of spatial locations on the irradiated sample surface [20]. Thus, recorded is a three-dimensional data cube, with two coordinates representing the sample and one for the spectral dimension at each (x,y) point (cf. Figure 2). The spectral dimension in this case is only the intensity of a certain Raman band, used to identify the component of interest. This band should be unique for the component of interest of the sample and its intensity should be high enough in... 

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