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spectrum

spectrum

spectrum Sentence Examples

  • Our eyes are capable of seeing only a narrow spectrum of light.

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  • The dark lines of the spectrum of sunlight, earliest noted by Dr W.

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  • The spark spectrum of gold has been mapped by A.

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  • There is a certain amount of evidence that at any rate in some cases light is necessary, and that the violet rays of the spectrum are chiefly concerned.

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  • This change is associated with a change in the spectrum (N.

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  • Let AoBo be a plane wave-surface of the light before it falls upon the prisms, AB the corresponding wave-surface for a particular part of the spectrum after the light has passed the prisms, or after it has passed the eye-piece of the observing telescope.

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  • It is necessary that the aperture of the pupil be accommodated to the angular extent of the spectrum, or reciprocally.

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  • Of the seven lines he saw, he regarded the five most prominent as the natural boundaries or dividing lines of the pure simple colours of the prismatic spectrum, which he supposed to have four primary divisions.

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  • nor diminishes the If we define as the " dispersion " in a particular part of the spectrum the ratio of the angular interval dB to the corresponding increment of wave-length dX, we may express it by a very simple formula.

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  • If it be desired to see a given number of bands in the whole or in any part of the spectrum, the thickness of the retarding plate is thereby determined, independently of all other considerations.

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  • The question is whether, when the adjustment of focus is correct for the central rays of the spectrum, the error of phase for the most extreme rays (which it is necessary to consider) amounts to a quarter of a wave-length.

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  • That range between the smallest pea plant and the largest is the full spectrum of what that plant can be.

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  • The study of the latter he took up as a result of the publication in 1871 of an energy-curve of the spectrum by S.

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  • But, to obtain an equally good result in the m th spectrum, the error must be less than I/m of the above amount.'

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  • Let us suppose that the light is incident perpendicularly, and that the grating interval increases from the centre towards that edge which lies nearest to the spectrum under observation, and decreases towards the hinder edge.

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  • But, to obtain an equally good result in the m th spectrum, the error must be less than I/m of the above amount.'

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  • Let us suppose that the light is incident perpendicularly, and that the grating interval increases from the centre towards that edge which lies nearest to the spectrum under observation, and decreases towards the hinder edge.

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  • We will now consider the important subject of the resolving power of gratings, as dependent upon the number of lines (n) and the order of the spectrum observed (m).

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  • Mention may be made of the absorption spectrum of benzene.

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  • 2 " In the same way we may conclude that in flat gratings any departure from a straight line has the effect of causing the dust in the slit and the spectrum to have different foci - a fact sometimes observed " (Rowland, " On Concave Gratings for Optical Purposes," Phil.

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  • - These very remarkable bands are seen under certain conditions when a tolerably pure spectrum is regarded with the naked eye, or with a telescope, half the aperture being covered by a thin plate, e.g.

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  • It is evident that the effect at the focal point is the obliteration of the first and other spectra of odd order, so that as regards the spectrum of the first order we may consider that the two beams interfere.

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  • It is conspicuous by its absorption spectrum in many of the white stars.

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  • Unless the spectrum be of very high order, we have simply Bm : B = {a/(a+d) } 2 (4); so that the brightnesses of all the spectra are the same.

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  • Mag., 1837, 10, p. 364) was that any ray which suffered in traversing the plate a retardation of an odd number of half wave-lengths would be extinguished, and that thus the spectrum would be seen interrupted by a number of dark bars.

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  • Generally only one bow is clearly seen; this is known as the primary rainbow; it has an angular radius of about 410, and exhibits a fine display of the colours of the spectrum, being red on the outside and violet on the inside.

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  • Mag., 1837, 10, p. 364) was that any ray which suffered in traversing the plate a retardation of an odd number of half wave-lengths would be extinguished, and that thus the spectrum would be seen interrupted by a number of dark bars.

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  • This coloring matter, as shown by its absorption spectrum, picks out of the ordinary beam of light a large proportion of its red and blue rays, together with some of the green and yellow.

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  • We conclude that, with a grating composed of transparent and opaque parts, the utmost light obtainable in any one spectrum is in the first, and there amounts to I/wr 2, or about 6, and that for this purpose W a and d must be equal.

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  • When the retarding plate is held on the side towards the red of the spectrum, the bands are not seen.

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  • Thus in 1857 he went to Peru in order to determine the magnetic equator; in1861-1862and 1864, he studied telluric absorption in the solar spectrum in Italy and Switzerland; in 1867 he carried out optical and magnetic experiments at the Azores; he successfully observed both transits of Venus, that of 1874 in Japan, that of 1882 at Oran in Algeria; and he took part in a long series of solar eclipse-expeditions, e.g.

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  • The third spectrum has thus only 10f the brilliancy of the first.

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  • Babinet, the brightness of a lateral spectrum is not affected by an interchange of the transparent and opaque parts of the grating.

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  • For if the alternate parts were equal and alike transparent, but so constituted as to give a relative retardation of :IX, it is evident that the central image would be entirely extinguished, while the first spectrum would be four times as bright as if the alternate parts were opaque.

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  • In this table n is the refractive index of the glass for sodium light (the D line of the solar spectrum), while the letters C, F and G' refer to lines in the hydrogen spectrum by which dispersion is now generally specified.

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  • Thus in 1857 he went to Peru in order to determine the magnetic equator; in1861-1862and 1864, he studied telluric absorption in the solar spectrum in Italy and Switzerland; in 1867 he carried out optical and magnetic experiments at the Azores; he successfully observed both transits of Venus, that of 1874 in Japan, that of 1882 at Oran in Algeria; and he took part in a long series of solar eclipse-expeditions, e.g.

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  • After these syndromes, we come to the entire spectrum of mental illnesses, from depression to paranoia.

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  • By the end of disease, we accomplish all that the preceding paragraphs describe—the full spectrum of human ailments, vanquished from the globe.

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  • Pretend there is a spectrum of jobs from the best in the world down to the worst and everyone agrees on the order.

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  • But in describing that job spectrum, I never said anything about his absolute ability—I said only that he was at the bottom of the list relative to others.

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  • According to our former standard, this gives the smallest difference of wave-lengths in a double line which can be just resolved; and we conclude that the resolving power of a grating depends only upon the total number of lines, and upon the order of the spectrum, without regard to any other considerations.

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  • According to the principle already laid down it can make but little difference in the principal direction corresponding to the first spectrum, provided each line lie within a quarter of an interval (a+d) from its theoretical position.

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  • Later, in his article " Chromatics " in the supplement to the 5th edition of this encyclopaedia, he shows that the colours " lose the mixed character of periodical colours, and resemble much more the ordinary prismatic spectrum, with intervals completely dark interposed," and explains it by the consideration that any phasedifference which may arise at neighbouring striae is multiplied in proportion to the total number of striae.

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  • the production of pairs of glasses of widely differing refraction and dispersion, but having a similar distribution of dispersion in the various regions of the spectrum, was not in the first instance solved.

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  • This is shown by the following observations of Riihlmann on water, the light used being the D line of the spectrum: Eykmann's observations also support the approximate constancy of the Lorenz-Lorentz formula over wide temperature differences, but in some cases the deviation exceeds the errors of observation.

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  • In the case of the D lines the value of Sa/X is about 1/1000; so that to resolve this double line in the first spectrum requires moo lines, in the second spectrum 500, and so on.

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  • In addition, taking advantage of the accuracy with which the bolometer can determine the position of a source of heat by which it is affected, he mapped out in this infra-red spectrum over 700 dark lines or bands resembling the Fraunhofer lines of the visible spectrum, with a probable accuracy equal to that of refined astronomical observations.

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  • If a solution of the pigment is placed in the path of a beam of light which is then allowed to fall on a prism, the resulting spectrum will be found to be modified.

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  • A later result of this method of investigation was the discovery of a new member of the rare earths, monium or victorium, the spectrum of which is characterized by an isolated group of lines, only to be detected photographically, high up in the ultra-violet; the existence of this body was announced in his presidential address to the British Association at Bristol in 1898.

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  • By supposing the retardation to vary uniformly and continuously we, fall upon the case of an ordinary prism: but there;, is then no diffraction spectrum in the usual sense.

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  • The importance of his achievement may be judged from the fact that, while the visible spectrum includes rays having wave-lengths of from about o 4 p to 0.76, u, and no invisible heat-rays were known before 1881 having a wave-length greater than 1.8 µ, he detected rays having a wave-length of 5.3 A.

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  • BdXXo, a green bud, on account of a brilliant green line in its spectrum) in the selenious mud of the sulphuric acid manufacture; the chemical affinities of this element, on the one hand approximating to the metals of the alkalis, and on the other hand to lead, were mainly established by C. A.

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  • Ravenstein's map of Ben Nevis (1887) first employed the colours of the spectrum, viz.

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  • 8 a to oxidize when sparked with oxygen, and on examining it spectroscopically he saw that the spectrum was not that of argon, but was characterized by a bright yellow line near to, but not identical with, the D line of sodium.

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  • On the other end of the education spectrum, college degrees are up: A recent Harvard University study reports that 6.7 percent of the world has a college degree, up from 5.9 percent in 2000.

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  • of light of assigned wave-length in one spectrum, and as illustrating the frequently observed unsymmetrical character of the spectra on the two sides of the central image.'

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  • From (5) we see that, when the light falls perpendicularly upon a grating (0=o), there is no spectrum formed (the image corresponding to m=o not being counted as a spectrum), if the grating interval a or (a+d) is less than X.

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  • For this purpose Rowland places the eye-piece at 0, so that 0 =o, and then by (11) the value of '" in the m th spectrum is o- sin $' = tmX.

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  • He further expressed the belief that the dark lines D of the solar spectrum coincide with the bright lines of the sodium flame.

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  • In order that a large part of the field of view may be in focus at once, it is desirable that the locus of the focused spectrum should be nearly perpendicular to the line of vision.

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  • Fraunhofer further initiated the specification of refraction and dispersion in terms of certain lines of the spectrum, and even attempted an investigation of the effect of chemical composition on the relative dispersion produced by glasses in different parts of the spectrum.

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  • It is possible to prepare gratings which give a lateral spectrum brighter than the central image, and the explanation is easy.

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  • If we write p = 27rR/A (6), we must regard p as a function of f, and we may take with sufficient approximation under any ordinary circumstances where p' denotes the value of p at 0, and is a constant, which is positive when the retarding plate is held at the side on which the blue of the spectrum is seen.

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  • If we write p = 27rR/A (6), we must regard p as a function of f, and we may take with sufficient approximation under any ordinary circumstances where p' denotes the value of p at 0, and is a constant, which is positive when the retarding plate is held at the side on which the blue of the spectrum is seen.

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  • The method originally used by Huggins, who first conceived and proved the possibility of measuring stellar velocities in the line of sight, was to measure with a filar micrometer the displacement of some well-known line in a stellar spectrum relative to the corresponding line of a terrestrial spectrum.

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  • In the first place, with a given size of particles, the direction of complete polarization indicated by (23) is a function of the colour of the light, the value of 0 being 3 or 4 times as large for the violet as for the red end of the spectrum.

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  • In this way the scale can be viewed by a microscope of much higher magnifying power than can be employed for the photographed spectrum.

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  • Certain stars and nebulae show a bright line helium spectrum.

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  • It is recognized by its very characteristic spark spectrum.

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  • The salts show a characteristic absorption spectrum.

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  • In optics he was the first, in 1802, to observe the dark lines in the solar spectrum.

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  • We have now to consider the behaviour of light belonging to a neighbouring part of the spectrum.

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  • The sine of an angle can never be greater than unity; and consequently under the most favourable circumstances only 1/m 2 ir 2 of the original light can be obtained in the m u ' spectrum.

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  • If it were possible to introduce at every part of the aperture of the grating an arbitrary retardation, all the light might be concentrated in any desired spectrum.

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  • 8) be the direction of the principal maximum (middle of central band) for the wave-length X in the O h spectrum.

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  • Even in the contrary case, the thickness of the plate must not exceed a certain limit, dependent upon the purity of the spectrum.

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  • The aperture and the number of bands being both fixed, the condition of blackness determines the angular magnitude of a band and of the spectrum.

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  • of spectra, for the sun has an appreciable apparent diameter, and each point on its surface gives rise to an individual spectrum.

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  • above sea-level, discovered in 1881 an entirely unsuspected extension of the invisible infra-red rays, which he called the "new spectrum."

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  • Moseley, shortly after the discovery of the diffraction of X-rays by crystals, set to work to examine the X-ray spectrum of a number of elements each of which he made in turn the target of an X-ray tube.

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  • According to Krummel the following relations hold, good at 18° C. for the monochromatic light of the D line of the sodium spectrum in units of the fifth decimal place.

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  • caestus, sky-blue, from two bright blue lines of its spectrum.

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  • blue lines (of wave length 4555 and 4593) in their flame spectrum, but these are not present in the spark spectrum.

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  • There are many thousands of lines in the mercury spectrum, so that from this evidence it would appear that for mercury vapour n ought to be very great, and y almost equal to unity.

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  • The difficulty is further diminished when it is proved, as it can be proved, 2 that the modes of energy represented in the atomic spectrum acquire energy so slowly that the atom might undergo collisions with other atoms for centuries before being set into oscillations which would possess an appreciable amount of energy.

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  • At first he occupied himself with ordinary routine work, but being far from satisfied with the scope which this afforded, he seized eagerly upon the opportunity for novel research, offered by Kirchhoff's discoveries in spectrum analysis.

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  • In the general solar spectrum this element is represented by a large number of lines, but in the spectrum of the prominences and chromosphere one pair only can be detected.

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  • The striking discovery was, in 1903, made by the same investigators that the spontaneous luminosity of radium gives a spectrum of a kind never before obtained without the aid of powerful excitation, electrical or thermal.

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  • The modification of the spectrum of a radiating gas by a magnetic field, such as would result from the hypothesis that the radiators are the system of revolving or oscillating electrons in the molecule, was detected by P. Zeeman in 1896, and worked up, in conjunction with H.

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  • Sodium is most distinctly recognized by the yellow coloration which volatile salts impart to a Bunsen flame, or, better, by its emission spectrum which has a line (double), the Fraunhofer D, line, in the yellow (the wave-lengths are 5896 and 5890).

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  • The emission spectrum shows two lines, Ka, a double line towards the infra-red, and Ka in the violet.

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  • Sabine remarked when awarding him the Rumford medal of the Royal Society in 1872, contains a fundamental principle of spectrum analysis, and though for a number of years it was overlooked it entitles him to rank as one of the founders of spectroscopy.

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  • From 1861 onwards he paid special attention to the solar spectrum.

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  • He announced the existence of hydrogen, among other elements, in the sun's atmosphere in 1862, and in 1868 published his great map of the normal solar spectrum which long remained authoritative in questions of wave-length, although his measurements were inexact to the extent of one part in 7000 or 8000 owing to the metre which he used as his standard having been slightly too short.

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  • He was the first, in 1867, to examine the spectrum of the aurora borealis, and detected and measured the characteristic bright line in its yellow green region; but he was mistaken in supposing that this same line, which is often called by his name, is also to be seen in the zodiacal light.

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  • He especially devoted himself to investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere, and to that end devised various delicate methods and instruments, including his electric compensation pyrheliometer, invented in 1893, and apparatus for obtaining a photographic representation of the infra-red spectrum (1895).

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  • Its salts are reddish violet in colour, and give a characteristic absorption spectrum.

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  • The salts of praseodymium are green in colour, and give a characteristic spark spectrum.

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  • That is to say, the metre might be redetermined or restored as to its length within one ten-millionth part, by reference to, e.g., 1553163.5 wave-lengths of the red ray of the spectrum of cadmium, in air at 15° C. and 760 mm.

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  • As the light is twice refracted, the dispersion is increased, and the rays, after transmission through the prism, form a divergent system, which may be allowed to fall on a sheet of white paper, forming the wellknown solar spectrum.

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  • If now the prism P be interposed as in the figure, the whole beam is not only refracted upward, but also spread out into the spectrum RV, the horizontal breadth of the band of colours being the same as that of the original image S.

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  • By slightly turning the prism P, the position of the spectrum on the first screen could be shifted sufficiently to cause light of any desired colour to pass through.

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  • Operating on this beam with a second prism, he found that the homogeneous light was not dispersed, and also that it was more refracted the nearer the point from which it was taken approached to the violet end of the spectrum RV.

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  • The combined effect of the two is to produce a spectrum sloping up from left to right.

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  • The spectrum will be straight if the twoprismsaresimilar in dispersive property, but if one of them is con structed of a material which possesses any peculiarity in this respect it will be revealed by the curvature of the spectrum.

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  • If we compare the spectrum produced by refraction in a glass prism with that of a diffraction grating, we find not only that the order of colours is reversed, but also that the same colours do not occupy corresponding lengths on the two spectra, the blue and violet being much more extended in the refraction spectrum.

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  • If the increase of the angle of refraction were proportional to the diminution of wave-length for a prism of any material, the resulting spectrum would also be normal.

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  • bourhood of the D lines, is practically undeviated, so that it illuminates only a very short piece of the slit and is spread out into the ordinary spectrum.

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  • If the sodium is only gently heated, so as to produce a comparatively rarefied vapour, and a grating spectroscope employed, the spectrum obtained is like that shown in fig.

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  • Julius to explain the "flash spectrum" seen during a solar eclipse at the moment at which totality occurs..

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  • If suitable values are chosen for these constants, the formula can be made to represent the dispersion of ordinary transparent media within the visible spectrum very well, but when extended to the infra-red region it often departs considerably from the truth, and it fails altogether in cases of anomalous dispersion.

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  • In this way the existence of bands in the infrared part of the spectrum has been predicted in the case of quartz and detected by experiments on the selective reflection of the material.

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  • He wrote numerous papers on photometry and spectrum analysis in Poggendorff's Annalen and Berichte der k.

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  • Henry Draper's most important contributions to science were made in spectroscopy; he ruled metal gratings in 1869-1870, made valuable spectrum photographs after 1871, and proved the presence of oxygen in the sun in a monograph of 1877.

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  • spectrum, an appearance, and Gr.

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  • The announcement of the first discoveries made through the application of spectroscopy, then called spectrum analysis, appealed to the imagination of the scientific world because it revealed a method of investigating the chemical nature of substances independently of their distances: a new science was thus created, inasmuch as chemical analysis could =rT?

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  • H.) simplicity of the first experiments, pointing apparently to the conclusion that each element had its characteristic and invariable spectrum whether in the free state or when combined with other bodies, was soon found to be affected by complications which all the subsequent years of study have not completely resolved.

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  • Compound bodies, we now know, have their own spectra, and only when dissociation occurs can the compound show the rays characteristic of the element: this perhaps was to be expected, but it came as a surprise and was not readily believed, that elements, as a rule, possess more than one spectrum according to the physical conditions under which they become luminous.

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  • Spectrum analysis thus passed quickly out of the stage in which its main purpose was " analysis " and became our most delicate and powerful method of investigating molecular properties; the old name being no longer appropriate, we now speak of the science of " Spectroscopy."

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  • At present we have still to content ourselves with a much diminished intensity of light when working with gratings, but there is some hope that the efforts to concentrate the light into one spectrum will soon be successful.

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  • If on emergence the different portions he brought together at the focus it is obvious that the optical action must be in every respect similar to that of a grating when the nth order of spectrum is considered.

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  • The resolving power in the case of gratings is simply mn, where m is the order of spectrum used, and n the total number of lines ruled on the grating.

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  • Opticians should supply sufficient information of the dispersive properties of their materials to allow dµ/dX to be calculated easily for different parts of the spectrum.

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  • Defining oscillation as is usual in spectroscopic measurement by wave-length, the visible spectrum is found to extend from about 7700 to 3900 A.

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  • Salet observed that iodine gives a spectrum of bright bands when in contact with a platinum spiral made white hot by an electric current, and J.

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  • If a thickwalled capillary tube is passed over the platinum tube and its length so adjusted that the liquid rises in it by capillary action just above the level of the tube, the spectrum may be examined directly, and the loss of light due to the passage through the partially wetted surface of the walls of the tube is avoided.

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  • - The general recognition of spectrum analysis as a method of physical and chemical research occurred simultaneously with the theoretical foundation of the connexion between radiation and absorption.

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  • In consequence the question as to the connexion of the spectrum with the temperature of the gas seems to the present writer to lose some of its force.

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  • When now a small bead of a salt of sodium or lithium is placed in the flame the spectrum of the white hot platinum is traversed by the dark absorption of the D lines.

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  • The efforts which were consequently made in the early days of spectroscopy to discover some numerical relationship between the different wave lengths of the lines belonging to the same spectrum rather disregard the fact that even in acoustics the relationship of integer numbers holds only in special and very simple cases.

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  • Balmer, who showed that the four hydrogen lines in the visible part of the spectrum may be represented by the equation n = A(i - 4/s2), where n is the reciprocal of the wave-length and therefore proportional to the wave frequency, and s successively takes the values 3, 4, 5, 6.

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  • The most complete hydrogen spectrum is that measured by Evershed 8 in the flash spectrum observed during a total solar eclipse, and contains thirty-one lines, all of which agree with considerable accuracy with the formula, if the frequency number n is calculated correctly by reducing the wave-length to vacuo.9 It is a characteristic of Balmer's formula that the frequency approaches a definite limit as s is increased, and it was soon discovered that in several other spectra besides hydrogen, series of lines could be found, which gradually come nearer and nearer to each other as they become fainter, and approach a definite limit.

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  • In the case of those elements in which we can represent the spectrum most completely by a number of series, it is generally.

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  • Spectrum of Potassium.

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  • The most extensive series which has yet been observed is that of the trunk series of sodium when it is observed as an absorption spectrum; R.

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  • In the case of other metallic groups similar series have also been found, but while in the case of the alkali group nearly the whole spectrum is represented by the combined set of three series, such is not the case with other metals.

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  • In the spectrum of barium no series has yet been recognized.

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  • The spectrum of helium has been very carefully studied by Runge and Paschen.

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  • All its lines arrange themselves in two families of series, in other words, the spectrum looks like that of the superposition of two spectra similar to those presented by the alkali metals.

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  • Before leaving the subject, we return for a moment to the spectrum of hydrogen.

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  • Kayser on examining the spectrum recognized the fact that the two series were related to each other like the two branch series, and this was subsequently confirmed.

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  • If we compare Balmer's formula with the general equation of Ritz, we find that the two can be made to agree if the ordinary hydrogen spectrum is that of the side branch series and the constants a', b, c and d are all put equal to zero.'

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  • It seems remarkable, however, that we should not have succeeded yet in reproducing in the laboratory the trunk and main branch of the hydrogen spectrum, if the spectra in question really belong to hydrogen.

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  • According to this view the different lines are given out by different molecules, and we should have to take averages over a number of molecules to obtain the complete spectrum just as we now take averages of energy to obtain the temperature.

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  • King, that in the case of the so-called spectrum of cyanogen these tails can be observed.

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  • A band might in that case fade away towards zero frequencies, and as s increases, return again from infinity with diminishing distances, the head and the tail pointing in the same direction; or with a different value of constants a band might fade away towards infinite frequencies, then return through the whole range of the spectrum to zero frequencies, and once more return with its tail near its head.

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  • - The same spectrum may show differences according to the physical conditions under which the body emitting the spectrum is placed.

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  • In investigating the effects of mixture on the widening of lines in absorption spectrum, R.

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  • When we compare together electric discharges the intensity of which is altered by varying, the capacity, we are unable to form an opinion as to whether the effects observed are due to changes in the density of the luminous material or changes of temperature, but the experiments of Sir William and Lady Huggins 1 with the spectrum of calcium are significant in suggesting that it is really the density which is also the determining factor in cases where different concentrations and different spark discharges produce a change in the relative intensities of different lines.

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  • These lines in the case of the spark cannot be due entirely to the increased mass of vapour near the poles, but indicate a real change of spectrum probably connected with a higher temperature.

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  • The method adopted consisted in photographing the spectrum on a film which was kept in rapid motion by being attached to the front of a rotating disk.

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  • The component lines of a band spectrum do not as a rule give the Zeeman effect, and this seems to be connected with their freedom from pressure shifts, for when Dufour had shown that the bands of the fluoride of calcium were sensitive to the magnetic field, R.

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  • Bunsen first announced their discovery, for according to their view every combination of an element showed the characteristic spectrum of its constituent atoms; it did not matter according to this view whether a salt,' e.g.

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  • sodium chloride, introduced into a flame, was dissociated or not, as in either case the spectrum observed would be that of sodium.

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  • The experiment proves only the transparency of the gases experimented upon, and this is confirmed by the fact that bodies like bromine and iodine give on heating an emission spectrum corresponding to the absorption spectrum seen at ordinary temperatures.

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  • In many cases there is a considerable difficulty in deciding whether a particular spectrum belongs to a compound body or to one of the elements composing the compound.

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  • There is a vast amount of literature on the subject, but in spite of the difficulty of conceiving a luminous carbon vapour at the temperature of an ordinary carbon flame, the evidence seems to show that no other element is necessary for its production as it is found in the spectrum of pure carbon tetrachloride and certainly in cases where chlorine is excluded.

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  • Another much disputed spectrum is that giving the bands which appear in the electric arc; it is most frequently ascribed to cyanogen, but occasionally also to carbon vapour.

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  • Compounds generally show spectra of resolvable bands, and if an elementary body shows a spectrum of the same type we are probably justified in assuming it to be due to a complex molecule.

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  • These bands appear in the solar spectrum as we observe it, but are due to absorption by the oxygen contained in the atmosphere.

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  • Under different conditions we obtain (a) a continuous spectrum most intense in the yellow and green, (b) the spectrum dividing itself into two families of series, (c) a spectrum of lines which appears when a strong spark passes through oxygen at atmospheric pressure, (d) a spectrum of bands seen in the kathode glow.

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  • Stark discovered that in the case of the series spectrum of hydrogen and of other similar spectra the lines were displaced indicating high velocities; in other cases no displacements could be observed.

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  • No conclusion can therefore be drawn, as Stark' has more recently pointed out, respecting the charge of the molecule which emits the observed spectrum.

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  • showed that the vibrating system of the fluorescent light seems identical with that observed by absorption in the fluted band spectrum, Wood excited the fluorescence by homogeneous radiation and discovered some remarkable facts.

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  • Relationship between the Spectrum of an Element and that of its Compounds.

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  • - In the present state of our knowledge we cannot trace any definite relationship between the spectrum of a compound body and that of its elements, and it does not even seem certain that such a relationship exists, but there is often a similarity between different compounds of the same element.

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  • As the atomic weight of the haloid increases the spectrum is displaced towards the red.

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  • The most typical case in this respect is the effect of a solvent on the absorption spectrum of a solution.

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  • The chromates of sodium, potassium and ammonium, as well as the bichromates of potassium and ammonium, were found to give the same absorption spectrum.

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  • Nor is the effect of these chromates confined to the blocking out simply of one end of the spectrum, as in the visible part, but two distinct absorption bands are seen, which seem unchanged in position if one of the above-mentioned chromates is replaced by another.

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  • The spectrum of nitrobenzene is also worth comparing with benzene and nitric acid.

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  • The detection of the presence of chlorine or bromine or iodine in a compound is at present undecided, and it may be well that we may have to look for its effects in a different part of the spectrum.

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  • Landauer, Spectrum Analysis (Eng.

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  • The salts have a faint pink colour, and show a faint absorption spectrum; the spark spectrum is brilliant and well characterized.

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  • He endeavoured, but in vain, to detect any change in the lines of the spectrum of a flame when the flame was acted on by a powerful magnet.

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  • The spectrum may now be further examined with a more powerful.

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  • The most conspicuous group in the argon spectrum at atmospheric pressure is that first recorded by A.

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  • It is of interest to note that the argon spectrum may be fully developed by operating upon a miniature scale, starting with only 5 c.c. of air (Phil.

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  • The spectrum shows remarkable peculiarities.

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  • A third spectrum is distinguished by J.

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  • The red spectrum is obtained at moderately low 'pressures (5 mm.) by the use of a Ruhmkorff coil without a jar or air-gap. The red lines at 7056 and 6965 (Crookes) are characteristic. The blue spectrum is best seen at a somewhat lower pressure (I mm.

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  • In some conditions very small causes effect a transition from the one spectrum to the other.

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  • From about 1864 he occupied himself almost exclusively with spectrum analysis, both of stars (Catalogo delle stelle di cui si e determinato lo spettro luminoso, Paris, 1867, 8vo; "Sugli spettri prismatici delle stelle fisse," two parts, 1868, in the Atti della Soc. Ital.) and of the sun (Le Soleil, Paris, 1870, 8vo; 2nd ed., 1877).

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  • the inner halo I, and the outer halo 0, having radii of about 22° and 46 °, and exhibiting the colours of the spectrum in a confused manner, the only decided tint being the red on the inside.

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  • Besides the blue and purple of the spectrum he was able to recognize only one colour, yellow, or, as he says in his paper, "that part of the image which others call red appears to me little more than a shade or defect of light; after that the orange, yellow and green seem one colour which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow."

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  • This slit is set in such a position as to transmit a single line of the spectrum, e.g.

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  • In the case of narrower lines, however, higher dispersion is required to prevent the light of the continuous spectrum on either side of the dark line from blotting out the monochromatic image.

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  • This forms an image of the solar spectrum in its focal plane on the camera slit (1).

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  • On the spectrum see Spectroscopy.

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  • Certain absorption bands at the blue end of the spectrum are supposed to be due to rare elements such as samarium.

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  • The spectrum, also, is very characteristic. The atomic weight, 226.4, places the element in a vacant position in group II.

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  • The spectrum of aurora consists of a number of lines.

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  • Its wave-length is probably very near 55'71 tenth-metres, and it is very close to, if not absolutely coincident with, a prominent line in the spectrum of krypton.

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  • Thus in the case of phycoerythrin the maximum absorption, apart from the great absorption at the blue end of the spectrum, is not, as in the case where chlorophyll occurs alone, near the Fraunhofer line B, but farther to the right beyond the line D.

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  • By an ingenious method devised by Engelmann, it may be shown that the greatest liberation of oxygen, and consequently the greatest assimilation of carbon, occurs in that region of the spectrum represented by the absorption bands.

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  • After the bacteria had all been brought to rest by being placed in the dark, he threw a spectrum upon the filament, and observed in what region the bacteria first regained their motility, owing to the liberation of oxygen in the process of carbon-assimilation.

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  • The spectrum contains a bright green of wave-length 5351.

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  • In 1868 they noticed in the solar spectrum a bright yellow line which did not correspond to any substance then known, and which they therefore attributed to the then hypothetical element, helium.

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  • lines, such as C and F, yet the flint glass prism will show a relative drawing out of the blue end and a crowding together of the red end of the spectrum, while the crown prism shows an opposite tendency.

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  • This want of proportion in the dispersion for different regions of the spectrum is called the "irrationality of dispersion"; and it is as a direct consequence of this irrationality, that there exists a secondary spectrum or residual colour dispersion, showing itself at the focus of all such telescopes, and roughly in proportion to their size.

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  • The only way in which the secondary spectrum can be reduced still further is by the employment of three lenses of three different sorts of glass, by which arrangement the secondary spectrum has been reduced in the case of the Cooke photo visual objective to about I/loth part of the usual amount, if the whole region of the visible spectrum is taken into account.

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  • The Aµ from C to F being taken as unity in each case then the AA's for the other regions of the spectrum are expressed in fractions A A (C to F) and are given under the asterisks.

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  • Hence it is clear that if the two positive lenses of equal curvature power of o 60 and 0.102 respectively are combined with a negative lens of light flint o 569, then a triple objective, having no secondary spectrum (at any rate with respect to the blue rays), may be obtained.

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  • The table gives their partial dispersions for six different regions of the spectrum also expressed (in brackets below) as fractional parts of the dispersion from C to F.

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  • It was discovered in 1875 through its spectrum, in a specimen of zinc blende by Lecoq de Boisbaudran (Comptes rendus, 1875, 81, p. 493, and following years).

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  • Gallium is best detected by means of its spark spectrum, which gives two violet lines of wave length 4171 and 4031.

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  • Stars having this type of spectrum are always variable, and a large proportion of the more recently discovered long-period variables have been detected through their characteristic spectrum.

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  • If both the bodies are luminous, especially if they do not differ much in brilliancy, the motion of revolution is shown by a periodic doubling of the lines of the spectrum; when one body is moving towards us and the other away their spectral lines are displaced (according to Doppler's principle) in opposite directions, so that all the lines strong enough to appear in both spectra appear double; when the two bodies are in conjunction, and therefore moving transversely, their spectra are merged into one and show nothing unusual.

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  • More usually, however, only one component is sufficiently luminous for its spectrum to appear; its orbital motion is then detected by a periodic change in the absolute displacement of its spectral lines.

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  • That the effect is due to a real difference in the character of the light from the two components has been shown by spectrum analysis, but it is probably exaggerated by contrast.

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  • The spectrum consists of of a continuous band of light crossed by a greater or Spectra .

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  • the case of the sun, this indicates an incandescent body which might be solid, liquid, or a not too rare gas, surrounded by and seen through an atmosphere of somewhat cooler gases and vapours; it is this cooler envelope whose nature the spectroscope reveals to us, and in it the presence of many terrestrial elements has been detected by identifying in the spectrum their characteristic absorption lines.

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  • The spectrum, which closely resembles that of a sunspot, is marked by flutings or bands of lines sharply bounded on the violet side and fading off towards the red.

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  • spectra has been recognized, in which, as well as the usual absorption bands, bright emission lines of hydrogen appear; stars having this particular spectrum are always variable.

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  • Finally, a fifth type has been added, the Wolf-Rayet stars; these show a spectrum crossed by the usual dark lines and bands, but showing also bright emission bands of blue and yellow light.

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  • - The absence of the distinctive lines of an element in the spectrum does not by any means signify that that clement is wanting or scarce in the star.

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  • The spectroscope only yields information about the thin outer envelope of the star; and even here elements may be present which do not reveal themselves, for the spectrum shown depends very greatly on the temperature and pressure.

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  • In this connexion it may be noted that the spectrum of Nova Persei, after passing through a stage in which it resembled that of a planetary nebula, has now become of the Wolf-Rayet type.

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  • The stars of the Helium type of spectrum are remarkable for the smallness of their velocities; from spectroscopic observations of over 60 stars of this class, J.

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  • The group consisting of five stars of Ursa Major together with Sirius has already been alluded to; another very marked group of 16 stars in Perseus, all of the Helium type of spectrum, form a similar association.

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  • For the spectrum analysis of stars, Schemer's Astronomical Spectroscopy (trans.

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  • a-, privative, xpcopa, colour), in optics,, the property of transmitting white light, without decomposing it into the colours of the spectrum; "achromatic lenses" are lenses which possess this property.

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  • white light) all these images are formed; and since they are all ultimately intercepted by a plane (the retina of the eye, a focussing screen of a camera, &c.), they cause a confusion, named chromatic aberration; for instance, instead of a white margin on a dark background, there is perceived a coloured margin, or narrow spectrum.

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  • For example, the condition for achromatism (4) for two thin lenses in contact is fulfilled in only one part of the spectrum, since do /dn 1 varies within the spectrum.

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  • Fraunhofer, who defined the colours by means of the dark lines in the solar spectrum; and showed that the ratio of the dispersion of two glasses varied about 20% from the red to the violet (the variation for glass and water is about 50%).

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  • Moreover, this region of the spectrum is that which appears brightest to the human eye, and consequently this curve of the secondary spectrum, obtained by making f c=1 F, is, according to the experiments of Sir G.

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  • Fraunhofer prepared glasses which reduced the secondary spectrum; but permanent success was only assured on the introduction of the Jena glasses by E.

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  • In uniting three colours an " achromatism of a higher order " is derived; there is yet a residual " tertiary spectrum," but it can always be neglected.

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  • It increases rapidly with the aperture, and is more important with medium apertures than the secondary spectrum of par-axial rays; consequently, spherical aberration must be eliminated for two colours, and if this be impossible, then it must be eliminated for those particular wave-lengths which are most effectual for the instrument in question (a graphical representation of this error is given in M.

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  • - Secondary Spectrum of the combination O.

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  • TARSIER, the Anglicized form of the scientific name of a small and aberrant lemur-like animal, Tarsius spectrum, inhabiting the Malay Peninsula and islands, and typifying a family.

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  • The name tarsier refers to the great elongation of two of the bones of the tarsus, or ankle, and spectrum to the huge goggle-like eyes and attenuated form which constitute two of the most distinctive features of this weird little creature.

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  • Engelmann showed, for instance, that these red-purple bacteria collect in the ultra-red, and to a less extent in the orange and green, in bands which agree with the absorption spectrum of the extracted colouring matter.

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  • cyanogenus gives a band in the yellow and strong lines at E and F in the solar spectrum - an absorption spectrum almost identical with that of triphenyl-rosaniline.

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  • 17, except that two slit-like openings of equal length allowed the light to pass, and that the light was that of the electric arc passed through a quartz prism and casting a powerful spectrum on the plate.

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  • The principal experiments also indicate that it is the rays of highest refrangibility - the blue-violet and ultra-violet rays of the spectrum - which bring about the destruction of the organisms (figs.

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  • W.) split by means of energy derived from the oxidation of nitrogen, but apart from the fact that none of these processes can proceed until the temperature rises to the minimum cardinal point, Engelmann's experiment shows that in the purple bacteria rays are used other than those employed by green plants, and especially ultra-red rays not seen in the spectrum, and we may probably conclude that " dark rays " - i.e.

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  • rays not appearing in the visible spectrum - are absorbed and employed by these and other colourless bacteria.

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  • As is shown by his verses and sometimes by his prose, his mind was highly imaginative; the poet Coleridge declared that if he "had not been the first chemist, he would have been the first poet 1 Davy's will directed that this service, after Lady Davy's death, should pass to his brother, Dr John Davy, on whose decease, if he had no heirs who could make use of it, it was to be melted and sold, the proceeds going to the Royal Society" to found a medal to be given annually for the most important discovery in chemistry anywhere made in Europe or Anglo-America."The silver produced £736, and the interest on that sum is expended on the Davy medal, which was awarded for the first time in 1877, to Bunsen and Kirchhoff for their discovery of spectrum analysis.

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  • von Bunsen, to the development of spectrum analysis as a complete system in 1859-1860.

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  • He can scarcely be called its inventor, for not only had many investigators already used the prism as an instrument of chemical inquiry, but considerable progress had been made towards the explanation of the principles upon which spectrum analysis rests.

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  • A rain-band is "a dark band in the solar spectrum, caused by the presence of water-vapour in the atmosphere" (New Engl.

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  • Kirchhoff in announcing that the lines of the spectrum were characteristic of the chemical substance which emitted them, and in indicating the value of this discovery in chemical analysis.

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  • According to Hittorf he was the first who saw the three lines of the hydrogen spectrum, which a few months after his death were recognized in the spectrum of the solar protuberances, and thus solved one of the mysteries of modern astronomy.

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  • Lithium is detected by the faint yellow line of wave-length 6104, and the bright red line of wave-length 6708, shown in its flame spectrum.

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  • absorbere) means literally "sucking up" or "swallowing," and thus a total incorporation in something, literally or figuratively; it is technically used in animal physiology for the function of certain vessels which suck up fluids; and in light and optics absorption spectrum and absorption band are terms used in the discussion of the transformation of rays in various media.

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  • This is not strictly the case, however, for such gases and vapours as exhibit well-defined bands of absorption in the spectrum, as these bands are altered in character by compression.

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  • The solution is moderately transparent for a large number of rays in the neighbourhood of the green part of the spectrum; it is, on the whole, much more opaque for red rays, but is readily penetrated by certain red rays belonging to a narrow region of the spectrum.

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  • The results of his labours may be found in the elaborate Photographic Map of the Normal Solar Spectrum (1888) and the Table of Solar Wave-Lengths (1898).

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  • They have lost completely the gaseous characteristic of producing a line spectrum, and radiate like incandescent solids.

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  • The surface region which yields a continuous spectrum is called the photosphere; it possesses optically a sharp boundary, which is generally a perfect sphere, but shows occasionally at the rim slight depressions or more rarely elevations.

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  • Enclosing the photosphere is a truly gaseous envelope which is called the chromosphere, and which shows a spectrum of bright lines when we can isolate its emission from that of the photosphere.

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  • The radiations from the sun must be considered in two parts, corresponding respectively to the continuous spectrum and the line-spectrum.

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  • It is then found both by experiment and by thermodynamic theory that in these amorphous radiations there is for each temperature a definite distribution of the energy over the spectrum according to a law which may be expressed by 0 5 0(OX)dX, between the wave-lengths X, A+dX; and as to the form of the function 4), Planck has shown (Sitzungsber.

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  • It will be seen that the maximum ordinates lie upon the curve A9 = constant dotted in the figure, and so, as the temperature of the ideal body rises, the wave-length of most intense radiation shifts from the infra-red X towards the luminous part of the spectrum.

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  • P. Langley in 18 93 at Mount Whitney in California (14,000 ft.), with the bolometer, an exceedingly sensitive instrument which he invented, and which enabled him to feel his way thermally over the whole spectrum, noting all the Constant.

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  • The continuous spectrum leads to no inference, except that of the temperature of the central globe; but the multitude of dark lines by which it is crossed reveal the elements composing pe ct rum o the truly gaseous cloaks which enclose it.

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  • The first problem of the spectrum is to identify the effects of atmospheric absorption, especially oxygen, carbonic acid and water vapour; this is done generally by comparing the spectra of the sun at great and small zenith-distances, or by reducing the atmospheric effect by observing from a great elevation, as did P. J.

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  • Paschen in 1896 identified an unmistakable oxygen triplet in the infra-red, which is shown terrestrially only in the vacuum tube, where the spectrum is very different from that of atmospheric absorptions.

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  • The absence of lines of the spectrum of any element from the solar spectrum is no proof that the element is absent from the sun; apart from the possibility that the high temperature and other circumstances may show it transformed into some unknown mode, which is perhaps the explanation of the absence of nitrogen, chlorine and other non-metals; if the element is of high atomic weight we should expect it to be found only in the lowest strata of the sun's atmosphere, where its temperature was nearly equal to that of the central globe, and so any absorption line which it showed would be weak.

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  • The spectrum taken near the limb of the sun shows increased general absorption, but also definite peculiarities of great interest in connexion with the spectra of the spots, which it will be convenient to describe first.

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  • This is not a uniform shade over the whole length of the spectrum, but shows in bands or flutings of greater or less darkness, which in places and at intervals have been resolved by Young, Duner and other unquestionable observers into hosts of dark lines.

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  • Besides this the spectrum shows very many differences from the mean spectrum of the disk, the interpretation of which is at present far from clear.

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  • If the spot spectrum is compared with that of the chromosphere it appears that the lines of most frequent occurrence in the latter are those least affected in the spot, and the high level chromospheric lines not at all; the natural interpretation is that the spot is below the chromosphere.

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  • Hale and Adams have shown that the spectrum contains, besides a strong linespectrum of titanium, a faint banded spectrum which is that of titanium oxide, and a second banded part remarked by Newall has been identified by A.

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  • The band spectrum, which corresponds to the compound or at least to the molecule of titanium, certainly belongs to a lower temperature than the line spectrum of the same metal.

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  • Hence when the photosphere is viewed through it an absorption spectrum is shown, but when it can be viewed separately a bright line spectrum appears.

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  • In the higher chromosphere on occasions metallic gases are carried up to such a level that without an eclipse a bright line spectrum of many elements may be seen, but it is always possible to see those of hydrogen and helium, and by opening the slit of the spectroscope so as to weaken still further the continuous spectrum from the photosphere (now a mere reflection) the actual forms of the gaseous structures called prominences round the sun's rim may be seen.

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  • In the visual spectrum there are four hydrogen lines and one helium line in which the actual shapes may be examined.

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  • The helium formations do not reach the sun's limb, and it is another puzzling detail that the spectrum of the disk shows no absorption line of anything like an intensity to correspond with the emission line of helium in the chromosphere.

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  • The eruptive prominences, called also metallic, because it is they which show at their bases a complete bright line spectrum of the metallic elements, rush upwards at speeds which it is difficult to associate with transfers of matter; the velocity often exceeds loo m.

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  • Two other causes of displacement call for mention in their bearing on the solar spectrum - pressure and anomalous dispersion.

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  • The pressure which produces a continuous spectrum in gases at a temperature of 6000 0 must be very great.

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  • For example, in the iron spectrum three groups about wave-length 4500 are found by Duffield to be displaced respectively 0-17, 0.34, 0.66 tenth-metres, at 100 atmospheres.

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  • Though few follow him so far, an explanation of the principle will make it clear that there are numerous possible opportunities for anomalous dispersion to qualify inferences from the spectrum.

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  • back the coloured ribbon of the spectrum upon itself, but just where this is done all its light will be robbed to maintain the absorbing system in vibration.

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  • Omitting extreme examples, like fuchsin, where the spectrum is actually cut in two, it is of more general importance to detect the phenomenon in the ordinary absorption lines of the metallic elements.

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  • Puccianti, who measured it by the interferometer in the case of more than a hundred lines of different metals; he found its degree to differ much in different lines of the same spectrum.

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  • In calcium, for instance, the g line shows in the laboratory much stronger anomalous dispersion than H and K; but in the solar spectrum H and K are broad out of all comparison to g.

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  • Some of his opponents denied the truth of his experiments, refusing to believe in the existence of the spectrum.

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  • Others criticized the experiments, saying that the length of the spectrum was never more than three and a half times the breadth, whereas Newton found it to be five times the breadth.

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  • It appears that Newton made the mistake of supposing that all prisms would give a spectrum of exactly the same length; the objections of his opponents led him to measure carefully the lengths of spectra formed by prisms of different angles and of different refractive indices; and it seems strange that he was not led thereby to the discovery of the different dispersive powers of different refractive substances.

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  • calor, heat), a term invented by John Tyndall to describe an optical phenomenon, the essential feature of which is the conversion of rays belonging to the dark infra-red portion of the spectrum into the more refrangible visible rays, i.e.

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  • Thousands of the dark lines in the solar spectrum agree absolutely in wave-length with the bright rays artificially obtained from known substances, and appertaining to them individually.

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  • Its distinctive method is spectrum analysis, the invention and development of which in the 19th century have fundamentally altered the purpose and prospects of celestial inquiries.

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  • He mapped 324, chose out nine, which he designated by the letters of the alphabet, to be standards of measurement for the rest, and ascertained the coincidence in position between the double yellow ray derived from the flame of burning sodium and the pair of dark lines named by him " D " in the solar spectrum.

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  • The Indian eclipse of the 18th of August 1868 supplied knowledge of their spectrum, found to include the yellow ray of an exotic gas named by Sir Norman Lockyer " helium."

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  • Young caught the " flash spectrum " of the reversing layer, at the moment of second contact, at Xerez de la Frontera in Spain, on the 22nd of December 1870.

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  • Nebular chemistry was initiated by the same investigator when, on the 29th of August 1864, he observed the bright-line spectrum of a planetary nebula in Draco.

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  • Again by Sir William Huggins, the spectrum of the Orion nebula was photographed on the 7th of March 1882; and the method has gradually become nearly exclusive in the study of nebular emanations.

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  • A photograph of the spectrum of Tebbutt's comet, taken by him on the 24th of June 1881, showed radiations of shorter wave-lengths but identical source, and in addition, a percentage of reflected solar light marked as such by the presence of some well-known Fraunhofer lines.

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  • When, in the third quarter of the igth century, spectrum analysis was applied to the light coming to us from the heavenly bodies, a new era in astronomical science was opened up of such importance that the body of knowledge revealed by this method has sometimes been termed the "new astronomy."

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  • Even in a liquid form, the spectrum of any kind of matter is less characteristic than that of gas.

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  • Moreover, a gaseous body of uniform temperature, and so dense as to be non-transparent, does not radiate the characteristic spectrum of the gas of which it is composed.

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  • When the spectroscope was first applied in astronomy, it was hoped that the light reflected from living matter might be found to possess some property different from that found in light reflected from non-living matter, and that we might thus detect the presence of life on the surface of a planet by a study of its spectrum; but no hope of this kind has so far been realized.

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  • We have, in this brief view of the subject, referred mainly to the results of spectrum analysis.

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  • The true character of the light in this case may be revealed by analysing it with a spectroscope, when a spectrum is obtained traversed by dark bands corresponding to the constituents that are weakened or annulled.

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  • Arago pointed out, by supposing that in passing through the plate the plane of polarization of each monochromatic constituent is rotated by an amount dependent upon the frequency - an explanation that may be at once verified either by using monochromatic light or by analysing the light with a spectroscope, the spectrum in the latter case being traversed by one or more dark bands, according to the thickness of the plate, that pass along the spectrum from end to end as the analyser is rotated.

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  • Upsala, however, is a place where the auroral spectrum can often be observed in the sky, even when no aurora is visible, and it has generally been believed that what Angstrom really saw was an auroral and not a zodiacal spectrum.

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  • Wright, of New Haven, also made careful observations leading to the conclusion that the spectrum differs from sunlight only in intensity.

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  • He was unable to see any marked deviation of the spectrum from that of the sun; but it does not appear that either he or any other of the observers distinctly saw the dark lines of the solar spectrum.

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  • For example, the real image may be recorded on a photographic plate; it may be measured; it can be physically altered by polarization, by spectrum analysis of the light employed by absorbing layers, &c. The greatest advantage of the compound microscope is that it represents a larger area, and this much more completely than is possible in the simple form.

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  • the spectrum of zero order, can be admitted, no trace is generally found of the image of the grating.

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  • If the obliquity of illumination be so great that the principal maximum passes through the outermost edge of the objective, while a spectrum of 1st order passes the opposite edge, so that in the back focal plane the diffraction phenomenon shown in fig.

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  • If now the spectrum of Est order of the larger division be cut out from the diffraction figure, as is shown in fig.

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  • In systems employed for visual observation (to which class the microscope belongs) the red and blue rays, which include the physiologically most active part of the spectrum, are combined; but rays other than the two selected are not united in one point.

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  • By using these glasses and employing minerals with special optical properties, it is possible to correct objectives so that three colours can be combined, leaving only a quite slight tertiary spectrum, and removing the spherical aberration for two colours.

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  • In this, the secondary spectrum is so much lessened that for all practical purposes it is unnoticeable.

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  • The chief cone of rays then enters obliquely into the objective, the angle between the direct cone of rays and the diffraction spectrum of the first order can then become as large again as with direct lighting, and still be taken up in the objective.

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  • These diffracting details become especially distinct if the direct lighting cone of rays, the spectrum of zero:order or the chief maximum, is not allowed to enter the objective and instead only two or more diffraction maxima are taken up; the details then appear bright on a dark background.

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  • Chem., 1863, 89 by means of its spectrum.

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  • A broad spectrum of lighting effects allows them to offer the most competitive value for lighting in the industry.

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  • Broad spectrum antibiotics, including acyclovir, were initiated.

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  • adolescents with autistic spectrum disorder.

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  • aetiologyh the spectrum of severity is similar with different etiology, there may be a difference in outcome.

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  • angelic vocals transcend musical genres, giving her fans from all sides of the music spectrum.

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  • She was of the opinion that sensible legislation would be welcomed across the spectrum and hasty decisions would only bring anguish.

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  • announcement of the overall winners of the Full Spectrum open show.

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  • In recent years farmers have come to rely on the current very effective broad spectrum anthelmintics which are relatively cheap and easy to administer.

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  • All the crude extracts and the fractions exhibited a very good level of broad spectrum antibacterial activity.

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  • The clinical course progressed while patients being treated with wide spectrum antibiotics.

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  • VFEND, voriconazole, is a broad spectrum, triazole antifungal agent and is indicated as follows: - Treatment of invasive aspergillosis.

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  • Silver is a broad spectrum antimicrobial that helps to prevent infection.

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  • The response file used to generate the arf is written in the spectrum in the keyword RESPFILE.

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  • The code is currently at beta... asp - amiga SPectrum emulator aSp is a Sinclair ZX Spectrum Emulator for the amiga.

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  • Anne Church a personal assistant also from Ashworth who suggested color themes through the whole spectrum for the Ashworth Center.

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  • autism spectrum disorders have generated much response.

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  • Case study examples will be chosen across the whole spectrum of agricultural biotechnology.

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  • blackbody spectrum to obtain the Planck and Rosseland mean free paths.

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  • Doctors in full dress wear the velvet bonnet with Spectrum blue chord.

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  • broad spectrum of company law matters.

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  • There is an extender PCB which fits on to the Spectrum and a ribbon cable to the keyboard.

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  • The problem is that the Spectrum ROM handles this line interpretation as an arithmetic calculation, and calls its calculating routines.

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  • A first- or second-generation cephalosporin has the required spectrum of activity.

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  • Antibiotic rationale A third-generation cephalosporin has the required spectrum of activity against the majority of likely pathogens and is an appropriate initial choice.

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  • It burns with a brilliant blue flame - the name cesium derives from the sky-blue lines in its spectrum.

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  • For example, the Spectrum allows multiple program lines with each program line, separated by a colon.

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  • We also used a spectrum analyzer to show the coloration.

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  • colourrecent paintings have used, generally speaking, a limited number of colors chosen from a broad spectrum.

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  • Other people are very happy, and further down the spectrum, other people are what we may say suffering from mild contentment.

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  • Kirchhoff's second law A low-density gas will radiate an emission-line spectrum with an underlying emission continuum.

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  • In the wavelet spectrum that follows, an exact n FFT is used for the CWT's fast convolution.

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  • The power spectrum of oxygen isotope data from ocean sediment cores.

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  • counterfactual spectrum inversion scenario in which " spectrum inversion is rife " .

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  • Sinclair also said that about the Spectrum but immediately countermanded the idea by producing a range of games programs.

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  • criticized current U.S. policy toward spectrum allocation and called for a new 10-point " 21st century spectrum policy.

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  • Film director David Cronenberg was the world's first cyborg - being half human, half Spectrum 48k.

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  • Here is the spectrum of cytochrome c. The absorption pattern for all three cytochrome c. The absorption pattern for all three cytochromes changes markedly when these molecules are oxidized and reduced.

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  • dab technology allows broadcasters to transmit far more radio stations within the same comparable amount of radio spectrum compared to FM.

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  • William Potter: The first issue has got a Spectrum Shooter - which is a foam dart gun - which is surprisingly good actually!

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  • iodine deficiency is linked with a spectrum of motor disorders.

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  • At the extreme end of the spectrum, people can find themselves clinically depressed or even suicidal.

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  • Project Spectrum Project Spectrum offers an alternative approach to assessment and curriculum development for the preschool and early primary years.

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  • The Virkon S thermal fog system consists of: Virkon S the supreme broad spectrum virucidal disinfectant plus Virkon S fog enhancer.

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  • A broad spectrum, proven activity disinfectant should be used.

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  • The broad spectrum disinfectant Virkon S meets the needs.

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  • Can children with autistic spectrum disorders perceive affect in music?

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  • Its goal is to achieve " fully spectrum dominance ": a monopoly of the use of space for military purposes.

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  • RSA would provide a greater degree of protection from interference for spectrum that is used to provide the downlink.

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  • echo waveform and spectrum, directivity and cross talk.

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  • enhancing spectrum efficiency, for example looking at options for improving the use of spectrum by existing radar systems.

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  • eigenvalue spectrum provides an answer to the question of how many images are necessary to determine a reconstruction to a given resolution.

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  • electromagnetic spectrum opened for business.

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  • electromagnetic spectrum known as the extreme ultraviolet.

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  • The family of electromagnetic waves from the high-frequency gamma rays to the relatively low-frequency radio waves forms what is called the electromagnetic spectrum.

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  • While control of the entire electromagnetic spectrum is impossible, key portions must be commanded at the right time.

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  • elemental abundances and instrumental spectral resolution and then calculate and plot the spectrum.

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  • To alleviate such difficulties, it is common to assume a uniform emissivity over the entire wavelength spectrum.

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  • The Spectrum Emulator games cd a Spectrum emulator games cd a Spectrum Emulator CD with 3000 games.

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  • encompass a broad spectrum of drama and dance.

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  • encompasses learning difficulties, such as dyslexia, to various syndromes on the ' autism spectrum ' .

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  • entire spectrum of observed values.

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  • epic pn sensitivity limits for a point source with an = 0.7 power law spectrum, for different energy bands, see Table 5.

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  • These can be estimated in a way similar to the power spectrum, but more data is usually needed to get reliable estimates.

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  • etalon artifact suitable for the calibration of the wavelength scale of Optical Spectrum Analysers (OSAs ).

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  • exerting increasing leverage across the political spectrum.

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  • extreme of the spectrum is general Information Retrieval (IR ), as represented by web search search engines.

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  • Palestine is now a key fault line in US imperialism's effort to establish ' full spectrum dominance ' around the world.

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  • fazes through a spectrum of vibrant colors.

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  • fiducial wavelength around 7000 Angstroms by clicking on the spectrum of the star at about that wavelength.

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  • Why does the spectrum tick every fiftieth of a second?

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  • Positioned in railroad stations, airports and hotels, all payphone sites have a high consumer footfall ensuring that Spectrum sees ongoing healthy traffic.

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  • frequency spectrum itself is not ideal for masking speech.

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  • They searched harder and dug heavier for tracks on this second volume, with a musical spectrum spanning from raw funk to gritty soul.

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  • Spectrum Micro Neck gaiter Simple lightweight neck gaiter, ideal for general outdoor use.

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  • Her angelic vocals transcend musical genres, giving her fans from all sides of the music spectrum.

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  • Weiser defines a spectrum of access ranging from open to closed, with various gradations in between.

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  • A total of 24 sources were observed with one or both transmission grating spectrometers, from which 19 gave a useful spectrum.

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  • halide lights produce a strong output of the blue spectrum, which will result in strong plant growth.

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  • halogen lamp used in the dental clinic, emitting mainly in the blue part of the spectrum.

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  • hardness ratio indicate a harder spectrum.

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  • This is the spectrum of myoglobin, a mostly helical protein.

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  • Main use: One of the most widely used broad spectrum (non-selective ), systemic, post-emergence herbicide.

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  • MACHINE CODE put a hex on your Spectrum with the help of programmer Marcus Jeffrey.

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  • hibiscus mealybug has served to sensitize a wide spectrum of the public about biological control.

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  • The more reliable narrow spectrum hydrometer gave a reading of 1.026 which actually would mean a saline figure of 35.

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  • hypothecated taxation from spectrum receipts.

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  • They play a key role in the delivery of the spectrum of care needed by mentally ill people.

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  • improvements in spectrum efficiency.

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  • The amber color reduces the spectrum of light that the flying insects can see, thus sending them to a brighter source of light.

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  • interethnic coalition was formed before independence, and it occupied the center of the ethnic spectrum.

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  • interleaved spectrum ' and can be used for a variety of local or regional services.

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  • internuclear separations from the rotational spectrum of a diatomic molecule.

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  • interpolatetion spectrum can then be generated by interpolating between the points of the calibration spectrum.

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  • Further suppose that spectrum inversion does not in fact occur.

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  • Urea is the main form in which nitrogen is excreted in mammals UV radiation invisible rays that are part of the electromagnetic spectrum.

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  • The power spectrum of oxygen isotope data from ocean sediment cores.

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  • Women's Spectrum jacket IA Warm, durable fleece jacket in Berghaus ' own AWL 200 fleece fabric.

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  • Data is also collected on the spectrum of organisms isolated from cases of fungal keratitis.

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  • The light source was a halogen lamp used in the dental clinic, emitting mainly in the blue part of the spectrum.

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  • lightfast colors of relative transparency over a broad area of the spectrum.

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  • Domestic tungsten - Domestic tungsten lighting has a strong yellow/orange cast, because its color spectrum is shifted toward stronger wavelengths.

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  • When a gas is heated or a large electric current is passed through it, the gas emits a characteristic line spectrum.

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  • Positive ESI-MS m/z spectrum of the protien hen egg white lysozyme.

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  • mazurka op.17/4 And bear in mind that this piece lies at the definitive end of the editorial spectrum!

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  • The success with control of the hibiscus mealybug has served to sensitize a wide spectrum of the public about biological control.

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  • megahertz of spectrum to be auctioned off is less than half the amount in the 3G auction of 2000.

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  • ARMY AVIATION mission Army aviation performs the full spectrum of combat, combat support, and combat service support missions.

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  • Exercise You are provided with a spectrum of a compound (identified with a letter) having the molecular formula C 6 H 14.

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  • morph through a spectrum of colors or set to light up in one color.

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  • morphing through the spectrum from within the candle.

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  • All of these added up to a rather motley spectrum and to an ambivalent score.

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  • mumblehe end Rachael decided to be generous, mumbling something about how the pack should please anyone who's just bought a Spectrum.

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  • Professor Dermot Bowler The developmental neuropsychology of autistic spectrum disorders.

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  • opposite poles of a spectrum.

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  • Photonics Focus dropped into a session where speakers approached diffractive optics from extreme ends of the power spectrum.

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  • perforate study, only perforating ocular injuries were looked at rather than the whole spectrum of eye trauma cases.

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  • phenotype of autism: the clinical spectrum in twins.

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  • photoelectron spectrum of SF 5 CF 3 at a resolution of 0.3 nm.

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  • The nominal TiO in the X-ray photoelectron spectrum (XPS) upon which they rely heavily has almost certainly suffered surface oxidation.

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  • saturated pixels are flagged by a value of 32767 on the GPHOT image file, and can easily be identified during spectrum extraction.

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  • portion of the spectrum.

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  • The color of light A glass prism will split white light into a spectrum of colors.

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  • An AR spectrum's peaks are not linearly proportional to power.

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  • Preliminary evidence suggests increased activity of a broad spectrum cysteine protease.

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  • Our findings are discussed with respect to previous works on the spectrum of energetic protons in the 10 MeV to GeV energy range.

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  • purifyffer a selection of high quality, purified genomic DNA suitable for a wide spectrum of genetic research applications.

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  • Almost one quarter of these are members of a previously unknown class of X-ray bright, flat spectrum, radio-loud quasars.

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  • The station will also be on air in Germany as it has secured space on the German digital radio spectrum.

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  • At a stroke MVNO could remove the absolute barrier to entry arising from the finite available radio spectrum.

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  • The company was one of the first to manufacture an independent 16K ram pack for the Spectrum.

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  • real timeet Spectrum Analyzer allows network managers to: perform real-time RF spectrum analysis for troubleshooting WLANs.

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  • receptive fields is designed in order to sample the power spectrum of a moving texture.

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  • resolvent operator; the Neumann series; the spectrum; spectral properties of bounded self-adjoint operators.

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  • It attracted riders from across the spectrum of cycling and it was particularly pleasurable to see members of Bristol Cycling Campaign strongly in evidence.

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  • But not before analog switch-off because of spectrum scarcity.

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  • These approaches combined show a potential way out of the current artificially created resource scarcity of spectrum.

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  • scrunch a spectrum or set of spectra.

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  • As a result, the low-frequency radio emission is affected by synchrotron self-absorption, giving cores a characteristically flat radio spectrum.

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  • On the other end of the spectrum, " Ride With Me " displays an almost breezy pop sensibility.

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  • CUTOFF Values more than CUTOFF times sigma away from the mean value for the spectral point will not be included in the final spectrum.

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  • The spectrum contains just one component, at 256 Hz, because the pure tone is a single sine wave.

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  • The Spectrum Any sound can be constructed by adding up enough sine waves of differing intensity levels, frequencies and starting times.

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  • Visitors can enjoy a wide spectrum of activities and a great number of museums and archeological sites.

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  • Objectives To share issues and methodologies in language and identity across the spectrum of applied linguistics, including sociolinguistics.

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  • span the spectrum of system criticality.

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  • The label designer encompasses a very broad spectrum of different mediums for John Rocha.

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  • During the two days of this conference, expert speakers from all quarters will span the spectrum of system criticality.

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  • Steve's address covered a wide spectrum ranging from the events of September 11th to the virtues of the internet.

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  • The enemy can use his vision across a broad band of the electromagnetic spectrum.

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  • Oliver advises on a broad spectrum of company law matters.

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  • More often people to find it helpful make sense of their experiences in light of the autistic spectrum.

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  • We have a wide spectrum of runners which start with people who just want to jog all the way through to top club athletes.

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  • Our century has seen the entire electromagnetic spectrum opened for business.

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  • I just translate that effect from a sound spectrum into a visible eye spectrum.

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  • spectrum analyzer is to be assembled on a satellite on Polar orbit 700 km above the surface of the Earth.

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  • spectrum disorder.

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  • spectrum dominance ": a monopoly of the use of space for military purposes.

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  • spectrum analyzer.

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  • spectrum inversion does not in fact occur.

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  • spectrum antibiotics.

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  • Health visitors advise on ASD Our recent pieces on autism spectrum disorders have generated much response.

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  • The cobalt is still Co 2+ as evidenced by the crystal field splitting of the Co L-edge peak in the absorption spectrum.

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  • Only by making better use of the radio spectrum can the visions be achieved.

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  • Road traffic noise is variable and the frequency spectrum itself is not ideal for masking speech.

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  • This thickness is then used in the analysis of the X-ray spectrum to correct for self absorption of X-rays in the sample.

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  • splattered all over the RF spectrum.

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  • sprite graphics on the Spectrum?

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  • subtracting the noise spectrum from the noisy speech spectrum.

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  • use a broad spectrum sunscreen with an SPF of 15 or above.

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  • Sunscreen Choose a ' broad spectrum ', factor 15+ sunscreen Choose a ' broad spectrum ', factor 15+ sunscreen.

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  • Intended for amateur radio operators, the book also gives instructions for smaller projects such as simple frequency synthesizer and spectrum analyzer.

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  • Hood in dove gray unlined, edged with Spectrum blue taffeta with a thin gold cord sewn to the leading edge of the hood.

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  • It could possibly be hypothecated taxation from spectrum receipts.

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  • terahertz region of the spectrum, " said Professor Davies.

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  • Striking graphics confusing ANYONE who has seen 3-D Tunnel will find Vortex for the 16K Spectrum familiar.

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  • transcend musical genres, giving her fans from all sides of the music spectrum.

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  • SOHO allows us to view the Sun in the part of the electromagnetic spectrum known as the extreme ultraviolet.

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  • uninspired games ever to disgrace the Spectrum.

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  • While top-end and mid-range are handled well, once again however the lower ends of the sound spectrum are left sadly unplumbed.

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  • utilize the spectrum more efficiently.

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  • The presence or absence of expression of these splice variants is being documented in normal tissues and a spectrum of brain tumors.

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  • The colors are ordered in the spectrum in the sequence red, orange, yellow, green, blue, indigo, violet.

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  • visible spectrum to a suitable band of X-ray energies.

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  • wavelet spectrum, which is similar to a smoothed FFT, is given by using the full time range.

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  • Hartford's spectrum basic a boston car heights insurance simple measure boththe zephyr xport then again blue.

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  • About the colour there can be no prima facie difficulty; for, as soon as the question is raised, it is seen that the standard of linear dimension, with reference to which the particles are called small, is the wave-length of light, and that a given set of particles would (on any conceivable view as to their mode of action) produce a continually increasing disturbance as we pass along the spectrum towards the more refrangible end.

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  • In passing from one part of the spectrum to another, A is the only quantity which varies, and we have the important law: - When light is scattered by particles which are very small compared with any of the wave-lengths, the ratio of the amplitudes of the vibrations of the scattered and incident lights varies inversely as the square of the wave-length, and the ratio of intensities as the inverse fourth power.

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  • In the first place, with a given size of particles, the direction of complete polarization indicated by (23) is a function of the colour of the light, the value of 0 being 3 or 4 times as large for the violet as for the red end of the spectrum.

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  • In this way the scale can be viewed by a microscope of much higher magnifying power than can be employed for the photographed spectrum.

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