Photographic identification

Separate from his earlier-described acoustical measurements, Medwin (ref. 31) conducted a direct photographic determination of microbubble populations in coastal ocean waters. His results indicated the presence of several million microbubbles per cubic meter (i.e., 103/liter) within the diameter range of 20 to 100 pm, both at the surface and at a depth of 10 feet in Monterey Marina (ref. 31,33). However, as a result of his technique of illumination, Medwin suggested that his count probably included many non-bubbles (ref. 31). 

To extend this type of microbubble study, Johnson and 

In field use, the camera system was suspended from a large float and allowed to drift freely. An initial 30-min delay in the timing circuit provided time for deployment of the apparatus before the first exposure, and permitted the movement of the ship downwind at least 0.5 km. Following the delay, photographs were made at 30-sec intervals until the entire roll of film was exposed. Following development, bubble images on the film were measured directly by microscope with the aid of an ocular micrometer (ref. 33). 

To further study the physical stability of these long-lived microbubbles, Johnson and Cooke also applied small negative and positive changes in pressure to the contents of the observation cell. When sufficient negative pressure was applied, the microbubbles expanded. These authors observed that expansion proceeded 

In an additional experiment designed to test the persistence of film-stabilized microbubbles as a function of time, a population of stabilized microbubbles generated by Johnson and Cooke was 

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Elephants from both populations were identified using characteristic ear markings, venation patterns, tusk features and other distinguishing marks such as a broken tail or scar. Photographic identification files were created for all new elephants and updated as needed for previously identified animals. Calves were identified by their association with known adult females (Moss Poole 1983 Wittemyer, Douglas-Hamilton and Getz 2005 Archie, Moss and Alberts 2006). 

Instant photographs are widely used for identification purposes, for example, for drivers Hcenses, student identification cards, and credit cards that can be issued immediately. Most passport photographs generated in the United States are instant color prints. Industrial and business appHcations include photographs of record for insurance purposes, constmction documentation, and real estate photography. 

Ecosystems for supply of predator faecal samples K. Horskins and D. Elmouttie of QUT for help in species identification from photographs H. F. Nahrung for help with statistical analyses and the late Dr. J. C. Wilson for encouragement, advice and help with experimental design. 

Resolution is constant and independent of wavelength thereby the identification of the wavelength of emission lines on a photographic plate is simplified i.e., once a known reference line is identified, other lines may be known very conveniently. 

PARK is a Cabinet server that provides photographs for the purpose of plant identification. All photographs are annotated. The database is searchable in multiple languages (English, Latin and Chinese). Photographic sources are images from collections such as the Atlas of the Chinese Materia Medica [43]. 

SPECIAL NOTE- No illustrations of the various toxic plants and fungi are provided. Black and white photographs or drawings are generally inadequate or proper identification. Any decent bookstore or ibrary has books on poisonous plants with color illustrations. Use one of these as your guide. 

A) the name, address, and date of birth appearing on a valid identification document (as defined in section 1028(d)(1)) of the transferee containing a photograph of the transferee and a description of the identification used ... 

A century ago, the reduction of silver ions in photographic plates helped W. Roentgen [1], then H. Becquerel [2], to discover x-rays and radiation of radioactive elements, respectively. Various metal ions were subsequently used widely in aqueous solutions as radical scavengers and redox indicators of the short-lived primary radiolytic species, allowing their identification and the calibration of their yield of formation [3-5]. Some underwent reduction by y [6] or pulse radiolysis [7] to the zero-valence metal, to form colloids and then precipitates [7,8]. 

Collect two surface samples from each part of preparation tank per attached (provide photographs of vial-filing machine parts with sample identifications). 

Use of X-ray diffraction patterns or identification. Even when complete structure determination is not possible, however, much valuable information of a less detailed character may be obtained by X-ray methods. In the first place, the diffracted beams produced when X-rays pass through crystals may be recorded on photographic films or plates, and the patterns thus formed may be used quite empirically, without any attempt at interpretation, to identify crystalline substances, in much the same way as we use optical emission spectra to identify elements, or infra-red absorption spectra to identify molecules. Each crystalline substance gives its own characteristic pattern, which is different from the patterns of all other substances and the pattern is of such complexity (that is, it presents so many measurable quantities) that in most cases it constitutes by far the most certain physical criterion for identification. The X-ray method of identification is of greatest value in cases where microscopic methodsare inadequate for instance, when the crystals are opaque or are too small to be seen as individuals under the microscope. The X-ray diffraction patterns of different substances generally differ so much from each other that visual comparison... 

Chapter V, on identification by X-ray methods, is concerned with the practical details of taking X-ray powder photographs, and also includes elementary diffraction theory, taken as far as is necessary for most identification problems. 

The optical properties of crystals are usually quite reliable criteria for identification but occasionally crystals have sifbmicroscopic cracks and cavities, and although appearing quite normal, give refractive indices lower than those of an entirely solid crystal. This phenomenon, which is obviously very misleading, is fortunately very rare, but has been observed in anhydrite (calcium sulphate) and calcite (calcium carbonate) prepared in the laboratory. In cases erf doubt, X-ray powder photographs should be taken—see Chapter V. 

Powder cameras. A powder camera consists essentially of an aperture system to define the X-ray beam, a holder for the specimen, and a framework for holding the photographic film. For most identification purposes a camera 9-10 cm in diameter is found satisfactory an X-ray beam about 0 5 mm wide is generally used, the powder specimen being a little narrower than this—of the order of 0 3 mm. 

Sharp photographs with a low background intensity are produced by such cameras. Focusing cameras, however, are used less for identification than for special purposes such as the accurate determination o unit cell dimensions. Further information on this subject will be found on p. 193. 

Identification of single substances, and classification of powder photographs. Each crystalline substance has its own set of plane-spacirfgs, which is different from those of other crystalline substances. The relative intensities of the various reflections are also characteristic. Each substance thus gives its own characteristic powder photograph, the scale of which, however, depends on the wavelength of the X-rays used and the diameter of the camera. 

If the spacings of the arcs on a powder photograph do not lead to identification, the determination of unit cell dimensions from the powder photograph may be attempted the methods are described in Chapter VI. If crystals large enough to be handled individually can be picked out of the specimen, single-crystal rotation photographs may be taken and used for identification this also is dealt with in Chapter VI. 

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