Video imaging

Fig. 3.9. Video images, ion-induced secondary of a defect in car paint white signal corresponds electron images, and mass-resolved ion images to high intensities, black to low intensities [3.19].

Fig. 24. Experimental set-up of Harding and Berg for testing the single-particle composites. The digital video image shows an example of a failed interface for a silane-treated glass bead in polymer matrix. Redrawn from ref. [166].

The spinning drop technique measures the shape of the oil drop in the flooding solution in a capillary tube. An automatic measuring system has been developed by combining a video-image analysis, an automatic recording system, and a computer for calculation of the interfacial tension [1865]. 

The nature of mass transport in MEMED has been confirmed with both ampero-metric and potentiometric studies of bromine transfer from an aqueous phase to DCE [79]. Figure 17 shows typical amperometric data for this case, in which the DCE phase acts as a sink for Br2, and a depleted region of Br2 is measured adjacent to the droplet in the aqueous phase. Video images are also provided, which correspond to particular times during the amperometric transient at position (3) the edge of the developing concentration boundary layer, around the drop, reaches the electrode the concentration profile is then mapped out between points (3) and (4). The measured current, i, can be related to the local concentration, c, via... 

Recently, Samec et al. [38] have investigated the same system by the video-image pendant drop method. Surface tension data from the two studies are compared in Fig. 2, where the potential scale from the study [36] was shifted so that the positions of the electrocapillary maxima coincide. The systematic difference in the surface tension data of ca. 3%, cf. the dotted line in Fig. 2, was ascribed to the inaccurate determination of the drop volume, which was calculated from the shape of the drop image and used further in the evaluation of the surface tension [38]. A point of interest is the inner-layer potential difference A (pj, which can be evaluated relative to the zero-charge potential difference A cpp c by using Eq. 

Girault and Schiffrin [6] and Samec et al. [39] used the pendant drop video-image method to measure the surface tension of the ideally polarized water-1,2-dichloroethane interface in the presence of KCl [6] or LiCl [39] in water and tetrabutylammonium tetraphenylborate in 1,2-dichloroethane. Electrocapillary curves of a shape resembling that for the water-nitrobenzene interface were obtained, but a detailed analysis of the surface tension data was not undertaken. An independent measurement of the zero-charge potential difference by the streaming-jet electrode technique [40] in the same system provided the value identical with the potential of the electrocapillary maximum. On the basis of the standard potential difference of —0.225 V for the tetrabutylammonium ion transfer, the zero-charge potential difference was estimated as equal to 8 10 mV [41]. 

In a closely related study, Marecek et al. [46] used the pendant drop video-image method to investigate the adsorption and surface reactions of calix[4]arene ligands at the ideally polarized water-1,2-dichloroethane interface. The difference between the surface tensions in acidic and alkaline media was ascribed to a difference in the charge on the... 

Koryta et al. [48] first stressed the relevance of adsorbed phospholipid monolayers at the ITIES for clarification of biological membrane phenomena. Girault and Schiffrin [49] first attempted to characterize quantitatively the monolayers of phosphatidylcholine and phos-phatidylethanolamine at the ideally polarized water-1,2-dichloroethane interface with electrocapillary measurements. The results obtained indicate the importance of the surface pH in the ionization of the amino group of phosphatidylethanolamine. Kakiuchi et al. [50] used the video-image method to study the conditions for obtaining electrocapillary curves of the dilauroylphosphatidylcholine monolayer formed on the ideally polarized water-nitrobenzene interface. This phospholipid was found to lower markedly the surface tension by forming a stable monolayer when the interface was polarized so that the aqueous phase had a negative potential with respect to the nitrobenzene phase [50,51] (cf. Fig. 5). 

After addition of lipid DSPC into the organic phase a monolayer is formed at the interface, and the steady-state current increased at all potentials. On expansion, the time constant of the charging current is reduced to ca. 5 ms and a shift of ca. 100 mV is observed in the potential of zero charge. From the video image of the droplet a highly distorted and heterogeneous interface is seen which relaxes after the fast stage (a few... 

In the mid-1980s, Fenske et al. (1986a,b 1993) described the use of fluorescent compounds coupled with video-imaging measurements to produce exposure estimates over virtually the entire body. The technique has been applied to pesticide mixers and applicators by Fenske and his coworkers, but has not been widely used by other investigators. 

Fenske, R. A., Leffingwell, J.T., and Spear, R.C. (1986a) A video imaging technique for assessing dermal exposure. I. Instrument design and testing, Am. Ind. Hygiene Assoc. ]., 47 764-770. 

Figure 12 IR transmission images of a polymer laminate. Left video image. Right IR image of the amide band (bright high COPA concentration). Only the COPA layers are visible in the FTIR image. The horizontal features in the middle layer are holes, originating during microtoming due to the material s softness.

Features of fast axonal transport demonstrated by biochemical and pharmacological approaches are apparent from video images 488... 

Many laboratories are equipped with commercial video frame grabbers and video image analysis systems, the operation of which is nicely explained by Russ (5). Many of the concepts involved apply both to video analysis and to the analysis of matrices obtained with a mechanical scanning stage driven by a stepper motor. Video scanning is very rapid, but slow mechanical scanning can be very precise and accurate. 

Fig. 5. Part of a video image of xylem vessels, exaggerating the size of the pixels and plotting them on a Laseijet printer. 

Fig. 30.1 Glass-bottomed observation cage equipped with an angled mirror mounted below used for filming pups behaviour during nursing as shown in the close-up video image on the right. Criss-crossed lines of silicon on the glass floor were to prevent animals slipping...

Figure 5.5. (a) Calculated trajectories of liquid metal sheet and droplets near a close-coupled atomizer (Atomization gas Ar, Ma = 1 at nozzle exit, Metal Ni, 7° = 1877 K, rii(JmL = 3.74). (Reprinted with permission from Ref. 325.) (b) High-speed video imaging of actual gas atomization process with a close-coupled atomizer. (Courtesy of Mr. Paul Martiniano and Dr. Paul Follansbee, General Electric Corporate R D, Schenectady, NY, USA.)... 

Figure 5.7. Comparison of numerical modeling to high-speed video imaging of droplet trajectories in the spray during spray forming. Left, calculated droplet trajectories Right, high-speed video imaging of an actual spray. (Courtesy of Prof. Dr.-Ing. Klaus Bauckhage at University of Bremen, Germany.)...

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