Drop image capturing

Drop Image Capturing and Drop Shape Analysis... 

On the basis of size observed under inverted phase contrast microscope and images captured with a high-speed camera, Florence and Whitehill classified multiple emulsions into three types type A, composed of relatively small multiple drops of mean diameter 8.5 pm containing a few relatively large internal droplets of mean diameter 3.3 pm type B, composed of larger multiple drops of mean diameter 19 pm containing smaller but more numerous multiple droplets of mean diameter 2.2 pm and type C, with vast number of very small internal droplets entrapped (Florence and Whitehill, 1982). 

The four images shown in the top row of Fig. 8.1 were captured just as a drop of water from a pipette hit the fabric. All four fabric samples were from the same new fabric pretreated to provide stain resistance. Fabrics treated for stain resistance also tend to be water resistant. The fabric sample on the far left had never been washed. The second fabric from the left had been washed once in a detergent, the third 5 times and the fabric on the far right had been washed 10 times prior to the experiment. The four images shown in the second row of Fig. 8.1 were collected after the drop of water had been allowed to spread for 0.5 s (five frames later). 

Figure 6.7 Liquid surface tension determination by the spinning drop tensiometer method. A liquid drop (7) is suspended in an immiscible denser liquid (2) in a horizontal transparent tube which can be spun about its longitudinal axis, and the drop (7) elongates from a spherical shape to a prolate ellipsoid with increasing speed of revolution. Later, the drop becomes approximately cylindrical, at very high rotational velocities. A camera with a frame grabber captures the images of the drop inside the transparent tube.

A dual-analyte fiber optic biosensor for O2 and glucose was developed by Li and Walt [22] based on O2 quenching of a phosphorescent ruthenium dye. Excitation was at X = 480 nm, with fluorescent emission captured by a CCD camera. A relatively large (350 (U,m diameter) imaging fiber with 6000 elements was modified by attaching two separate drops of ruthenium dye encapsulated in poly(hydroxyethyl methacrylate) polymer (HEMA). The ruthenium dye allowed measurements of O2 in both encapsulated drops, which were approximately 50 ixm in diameter. A two-site Stern-Volmer quenching model (equation (4.32) with n — 2) was used to determine O2 concentration from measurements of fluorescence intensity. One of the drops had the enzyme glucose oxidase (EC... 

Emulsions from VA/AA copolymers in distilled water were viewed using an optical microscope (Zeiss Axioplan 2 from Zeiss, Thornwood, NY) at lOOX and 400X magnifications. A drop of emulsion was placed between glass slides. Frames of i were captured using the Scion ImagePC computer software and stored onto disks as an image files. 

After 3 and 7 days, remove small leaf sections and place in a drop of water between a slide and coverslip (Fig. 3). Examine samples under UV light in the epifluorescence Zeiss Axioplan 2 HBIOO microscope with additional DIG filter (differential contrast) that can visualize GFP (excites at 488 nm) and RFP (excites at 543 nm). Capture the images with a Zeiss camera with AxioCam MRC5 using AxioVision software. 

A typical static sessile drop is created by a microsyringe with an automated plunger to place a tiny drop of water on the polymer surface. Ideally, the polymer sample should be in a humidity chamber to minimize the water evaporation that would change the shape, and thus the C A of the droplet. The shape of the droplet is captured by a camera and CA is measured by an image analysis software [30]. 

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