Photographic method

Both incident x-ray beams are collimated by pinholes, and the irradiated area on the specimen is a spot about inch (3 mm) in diameter, or smaller. The instrument is therefore well suited to making a rapid exploration of possible stress variations from point to point on a surface. Such variations, on an apparently uniform surface, are often surprisingly large. (With a diffractometer the irradiated area is usually about 1 cm, in order to obtain adequate intensity at the counter, and the observed stress is an average over that area.) 

This method of stress measurement is not often used today, because it is slower and less precise than the diffractometer method. However, the photographic method still has some advantages. The required apparatus is very simple a small back-reflection camera fixed to the head of a shockproof x-ray tube energized through a shockproof cable. This apparatus is smaller, lighter, more robust, and much cheaper than a mobile diffractometer. It is also more mobile and better suited to work in a confined space. 

Facilities for film development are needed, either a standard darkroom or, for field work, a portable darkroom in the form of a light-tight box with gloved portholes [16.12], Rapid-process film of the Polaroid Land type does not appear to have been adapted to stress cameras. 

Two exposures are made, with the incident beam inclined at a different angle to the specimen for each exposure [G.25, 16.3, 16.13, 6.8]. Only one side of the Debye ring on the film is measured in each exposure. This method is entirely analogous to the standard diffractometer method. 

A single inclined exposure is made, but both sides of the Debye ring are measured. 

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This method of chromatogram preservation has lost a great deal of its importance with the increasing perfection of photographic methods, particularly since true-colored, instant, paper and slide positives have become available. Photography is the more rapid method of documentation if suitable photographic equipment is available. 

C. F. Powell (Bristol) development of the photographic method of studying nuclear processes and discoveries regarding mesons made with this method. 

Flerman, R. S., Radiographic-Photographic Method for Measuring Depth and Distribution of Pitting , Corrosion, 20, 361 (1964)... 

The flow patterns of agitated liquid have been studied extensively (Al, B11, F6, K5, M6, N2, R12, V5), usually by photographic methods. Apparently no work has been reported on bubble-flow patterns and relative velocities in agitated gas-liquid dispersions. Some simple pictures have been presented that only show the same details that may be seen with the unaided eye (Bll, F6, Y4). 

Chandra and Avedisian 411] studied the collision dynamics of a liquid (n-heptane) droplet on a polished, solid, stainless steel surface, and on a liquid film created by deposition of a preceding droplet using a flash photographic method. They presented a comprehensive series of clear images of droplet shape, morphology, and structure during the deformation process. In their experiments, the... 

The photographic method for evaluating the bubble volume suffers from the disadvantage that it does not yield the volume directly but only gives the contour of the bubble in a single plane. The lighting used is purely a matter of trial and error. Assumptions have to be made regarding the symmetry of... 

First, they cannot be used for the evaluation of volumes of individual bubbles. Only an average bubble volume is obtained. Bubble formation is generally a cyclic phenomenon, and for a definite flow rate in a particular system, the frequency and the bubble volume are time-independent. However, there are situations where each bubble is followed by smaller secondary bubbles. In such cases, the above methods cannot yield reliable values and photographic methods have to be resorted to. 

The obtained low index surfaces were examined by Laue back reflection X-ray diffraction photograph method. Figures 2—10 show the obtained photographs. They represent a typical diffraction pattern for each surface and show that the quality of the each surface is high. The areas of the low index surfaces are 0.028, 0.024 and 0.025 cm for Ptdll), (110) and (100), respectively. 

Therefore, uniaxially oriented samples should be prepared for this purpose, which give so-called fiber pattern in X-ray diffraction. The diffraction intensities from the PPX specimen of P-form, which had been elongated 6 times at 285°C, were measured by an ordinary photographic method. The reflections were indexed on the basis of the lattice constants a=ft=2.052nm, c(chain axis)=0.655nm, a=P=90°, and y=120°. Inseparable reflections were used in the lump in the computation by the least square method. 

Size and Duration of Flame Produced on Explosion (19-20) Burning of Propellants (22-4) High-Speed Photographic Methods (44-7) Brisance by Plate Test (141-42) ... 

Title of a series of USBurMinesProgress Reports by C.M. Mason F.C. Gibson, Nos 1 to 8, beginning July 1, 1953 and ending June 30, 1955, OrdnProject TB2-0001, Army Project 599-01-004. This project was not really new but resulted from consolidation of two projects previously conducted separately as Fundamental Research on Explosives Phenomena and Detonation Involving Novel Photographic Methods , carried on respectively as Ordnance Projects TA3-5001 and TB2-0001... 

Two photographic methods have been used to observe the course of explns as they occur in impact testing) 35 a) W.R. Hess ... 

In the photographic method, the sizes and number of bubbles are measured on photographs of bubbles, but naturally there is wide distribution among the bubble sizes. 

With the development of the photomultiplier tube the measurement of very low light intensities has become relatively simple and the photoelectric recording of fluorescence emission spectra can now compete in terms of sensitivity with the less convenient photographic method. During the last decade the development of the experimental technique has gained considerable impetus as a result of the requirements of analytical chemists for methods of extreme sensitivity. A variety of spectro-fluorimeters have been described in the literature and commercial instruments of high sensitivity are also available. Recent reviews1-2 deal with the principles and analytical applications of fluorescence spectrometry and a textbook of biochemical applications has been published.2... 

By recording the raw Doppler signal on an oscillograph, drum camera, or similar device, it is possible to obtain projectile displacementtime information Photographic Methods... 

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