Bulletin of the Bureau of Standards, Volumen2U.S. Government Printing Office, 1906 Contains results of investigations, researches, etc., pertaining to scientific, technical and manufacturing interests of the country. |
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Bulletin of the Bureau of Standards, Volumen2 United States. Bureau of Standards Vista completa - 1906 |
Términos y frases comunes
accuracy accurate alloys alternating currents angle annealing approximately axis bands bulb calculated cent circles circuit circular coaxial coefficient coil computed constant correction cross section current sheet curve cylinder determined deviations diameter direct current effect electrodynamometer electromotive force elliptic integrals equation error experiments expression filament flicker formula frequency galvanometer given gives glass heating Hence ice point increase instrument insulation inverse square law light lines lower magnetic marble mean distance mean horizontal intensity mean radius measurements mercury meter method mirror movable coil mutual inductance Nernst Nernst glower number of turns observed obtained ohms photometer screen position potentiometer R₁ radiation reading reflection resistance revolutions per minute rheostat rotation scale self-inductance strip TABLE temperature thermometer tion torsion variation voltage volts wattmeter watts wave length width winding
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Página 354 - F and E are the complete elliptic integrals of the first and second kind, respectively, to modulus k.
Página 472 - Sulphates have a strong band at 4.55 /* and a less constantly recurring band at 9.1 fJ., due to the SO4 ion. On the other hand silicates do not have such definite bands, which would seem to indicate that the structure of the silicate radical is different in each mineral containing that element. The examination includes minerals of which the chemical constitution is in doubt; for example, talc and serpentine. The former is not supposed to contain hydroxyl groups while in the latter such groups are...
Página 472 - The interpretation of the results is based upon the assumption that if the union of the oxygen and the hydrogen in the molecule is similar to that in water, then the absorption spectra of minerals containing these two elements thus united should show the absorption bands of water superposed upon the absorption spectrum of the other constituents. On the other hand, minerals containing oxygen and hydrogen as water of constitution should not show the water bands, except hydroxyl groups, which should...
Página 459 - Group II. — Minerals Containing Water of Constitution. The first part of this group contains minerals in which the oxygen and hydrogen are present in the form of the univalent hydroxyl radical OH, and which are known as hydroxides. The hydroxides when heated also yield water, but it is a characteristic that they must be strongly heated before they are decomposed. From previous work, already mentioned, we would expect an absorption band at 3 ij, for hydroxides.
Página 160 - Ms, we can compute the self-inductance of the actual coil wound with wire of any particular size, the only assumption being that the current is uniformly distributed over the cross section of the wire. Max Wien's formula* for the self-inductance of a single circular turn of wire of radius a and radius of cross section p is (4) Substituting a = 25, p = .04, we have = 47rax 6.76720 cm.
Página 472 - On the other hand, minerals containing oxygen and hydrogen as water of constitution should not show the water bands, except hydroxyl groups, which should show a band at 3 p. The results show that of about 30 minerals containing "Water of crystallization" there are no important exceptions to the rule that they should show the bands of water. On the other hand the one important exception to the rule that minerals containing "water of constitution" should not show water bands is cane sugar.
Página 26 - CONCLUSIONS. The results of this investigation may be summarized as follows: (1...
Página 22 - Because the probable errors are less than o. 1 per cent, it does not necessarily follow, however, that the results are correct to the TABLE IV. Percentage Deviations from Talbot's Law Using White Light. Table IV, continued. same accuracy. Some constant source of error might possibly be present. It will be noticed from the table that approximately the same deviation was found for all the openings less than 120?
Página 60 - ... found from several unsuccessful determinations, it could not be dispensed with. Four such observations served for the determination of the current necessary to balance the torsional moment of the wire. Since the latter was twisted in every case 90 degrees, the torsional moment due to the wire was -v.
Página 456 - CENT 14 15« showing the permanence of the 4.55 p band. Beyond 6 /* the transparency increases and becomes 1.5 times as great as selenite at 6.9 p. The dehydrated section, which is an opaque white mass, was then moistened with water and allowed to stand over night to dry and set, just as in the case of plaster of Paris. The result is shown in curve r, where the transparency at 6.9 /* has decreased to almost the original value found for the transparent crystal.