Four groups of new methods of indirect ultrasonoscopy and ultrasonography are developed: those using temperature-sensitive chromotropic compounds, those using leucobases of dyes, those using thermo-stimulable phosphors, and those using special temperature-sensitive phosphors. Various techniques are described and some results shown in the illustrations. Finally, a new method of direct ultrasonography is proposed. This method makes use of the possibility to detonate certain labile chemical compounds by ultrasonics.N the ultrasonographic investigations, on which the first named author • reported in a previous issue of the Journal, serious difficulties arose from the heat developed in the ultrasonic field unless careful precautions were taken. Therefore, it was very natural to try whether methods of indirect ultrasonoscopy and/or ultrasonography could be developed with the heat effect as the primary effect. In what follows a concise account is given of a series of successful experiments conducted chiefly although not exclusively along this line and some illustrative results are shown.In Table I the various methods of ultrasonoscopy and ultrasonography discussed in this paper are classified and tentatively named with reference to the recording material. A. CHROMOTROPIC METHODS a. Thermo-Chromotropic MethodIn thermo-chromotropic methods substances are applied which change their colors upon heating. They are designated as temperature-sensitive chromotropic compounds and especially as reversibly-chromotropic, if they possess the property of regaining their original colors on cooling down to their initial temperatures.Among the reversibly-chromotropic compounds used in the experiments under discussion here mercury silver iodide had the greatest temperature-sensitivity. This substance was made according to Rosenberg's 2 direc-* Presented at the 42nd meeting of the Acoustical Society of America, Chicago, October 23, 1951. • This paper represents an essential part of a thesis submitted by the second named author to . The recipe reads translated from German:Dissolve 17 g of silver nitrate in about 150 cm s of distilled water and also 16.6 g of potassium iodide in 150 cm a of distilled water. Mix both solutions well in a flask. Filter off the yellow precipitate of silver iodide, wash it thoroughly on the filter paper with distilled water, and allow both the filter and the residue on it to dry in a dark place. Dissolve 13.6 g of mercuric chloride in about 400 cm 3 of distilled water and add a solution of 16.6 g of potassium iodide in 100 cm s of distilled water. Filter off the deep-red precipitate of mercuric iodide, wash it thoroughly on the filter paper with tions. The preparation was impasted, with nitrocellulose lacquer as a binder, on a sheet of stiff, thin, and glossy drawing paper and allowed to dry. Later a plastic film screen was made which gave better results than the paper screen.The chromotropic screen was irradiated ultrasonically and the hotter parts of the ultrasonic field, such as the focus of a concentration de...
Methods approved in optics are applied to the measurement and specification of ultrasonic lenses.T may be confidently expected that ultrasonic lenses will be put into general use very soon. It seems, therefore, to be opportune to suggest a method of measuring and specifying them. This is all the easier as the approved methods used in optics can be likewise applied to ultrasonics.For this simulation, in addition to the radius of curvature and focal length of an ultrasonic lens, their reciprocals, the curvature and focal power, ß have to be introduced. I suggest the adoption of the optical unit of refractive power, the diopter D, and as its appropriate name, when used in ultrasonic work, "diacouster Dac." As the acoustical focal length and focal power of an ultrasonic lens depend on the medium of propagation, a standard liquid must be c. hosen. It is convenient to use water as this standard because its properties are stable and accurately known.The curvature R of an ultrasonic lens expresse. d in reciprocal meters is, of course, the same as in optics, R= 100/r in cm=39.37/r in inches. (1)Then from the fundamental paraxial equation for the refraction at a spherical surface it follows that the acoustical focal power Fac expressed in D• is given bywhere u=v•/v•, v• and v• being the ultrasonic velocities in the solid and liquid respectively. Also an "acoustician's lens measure" can be built, based on the same principle as the widespread "optician's lens measure," and more than this, within a limited range the optician's lens measure itself can be used for ultrasonic lenses, if the values of the divisions are converted. The readings of the optician's instrument are known to be calculated for the refractive index 1.523, therefore F=0.523R. (3) The acoustician's instrument has to show F•c = -(vs/v•-1)R.Consequently, F•= -F(v,/v•-l)/0.523. (5)A table, very easy to calculate, a simple graph, or a sliderfile will help to find corresponding values without any trouble. Since, within the range of frequencies generable at present, no dispersion of ultrasonic velocity occurs either in solids or in liquids, the acoustical focal length and focal power of an ultrasonic lens are independent of the frequency, in other words, even a single ultrasonic lens is "achromatic" or rather, "apochromatic," and the values obtained by means of a lens measure are valid for all frequencies.A very convenient comparison of the concentrating effects of ultrasonic lenses or lens systems is rendered possible by the introduction of the "aperture ratio," a quantity mainly used for the specification of photographic objectives. The aperture ratio is defined as the quotient of the entrance pupil of a lens system by its equivalent focal length or, in the case of a single lens, very nearly the quotient of the diameter of the lens by its posterior focal length. The aperture ratio is denoted as a quotient ..-1'3.5, 1'4.5, 1'6.3, 1: 9 ß ß ß and so on or as a fraction ß ß ß f/2, f/2.8, f/4, f/5.6 ... and so on.The effects produced by ultrasonic lenses under any gi...
Zur Erklarung des SchattenkreuzpEanomens in der orookeschen R5hre. Z.ph.ch.Unterr. 40 (1927). (c.p.) Eine einfache versueEsanordnung zum Rachweis der elektro-optischen Doppelbrechung. Z.m.natw.Unterr. 41 (1929) (c.p.) Miethes fluorographisch.es Verfahren zur Photographie von Versteinerungen. Das Bild, 5 (1928).-4-Der V/erdegang einer Lichtreklame-Leuchtrohre. Wr.Kaffeeh. 1 (1928). "" Die Photographie in den physikalischen Schiilerubungen. Das Biia, 5 (1928). Die Yerwendung des 'i'yponverfahrens in der Schule. Das Bild. 5 (1928). Lumineszenzproben fur schulversuche im Licht der Ana lyse nquarzlampe. Z.math.natw.Unterr. 61 (1929). Sensitometrische Priifung von'Typonpapier. Phot.Korr. 63 (1929). (c.p.) Sehulversuche iiber Warmewirkungen hochfrequenter Wechselstrome. Z.math.natw.Unterr. 61 (1929). (c.p.) Die Ultraviolett-iiapillaranalyse der pharmazeutischen Drogen. Pharm.Monatsh. 10 (1929). (o.p.) + Yorrichtung zum Sammeln und Zerstreuen, gerichteten Senden und Empfangen elektrischer wellen. Csterr.Pat.No.132272. La Nordlumobservado on Troms^. Austr.Esper. 7 (1930). Die Teehnik der Polarforschung von gestern und heute.
It is shown that with or even without ultrasonic lenses or other devices for the concentration of ultrasonic energy, by ultrasonics, images can be made on photo-sensitive emulsions. Several of the first ultra-sonographs, as these images are called, are reproduced and some potential fields of application of the new technique are mentioned.
The efficiency of all existing devices for the concentration of ultrasonic energy is considerably lowered by the losses cause by reflection, absorption, and diffraction. These losses, though generally unavoidable, can be minimized in various ways. The choice of suitable materials, use of “matching coatings,” design of “stepped lenses,” and development of “acceleration plates” will be discussed, samples of the improved devices shown and numerical and experimental data given.
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