| spectroscope | <instrument, physics> An optical instrument for forming and examining spectra (as that of solar light, or those produced by flames in which different substances are volatilized), so as to determine, from the position of the spectral lines, the composition of the substance. Origin: Spectrum + -scope. Source: Websters Dictionary (01 Mar 1998) |
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| direct vision spectroscope | <instrument> A spectroscope consisting of a single tube containing a series of prisms; one end of the tube is placed in as close contact as possible with the substance to be examined while the observer places his eye at the opposite end; it can be used to make a spectroscopic examination of the blood in vivo, as in the ear lobe or web of the thumb. (05 Mar 2000) |
| bacterial interference | The condition in which colonization by one bacterial strain prevents colonization by another strain. (05 Mar 2000) |
| viral interference | A phenomenon in which infection by a first virus results in resistance of cells or tissues to infection by a second, unrelated virus. (12 Dec 1998) |
| microscopy, interference | Microscopy in which physiological and photometric contrast in the image is influenced or produced by the action of optical components which regulate interference. (12 Dec 1998) |
| cuspal interference | A condition of tooth contact's which diverts the mandible from a normal path of closure to centric jaw relation. Synonym: cuspal interference, interceptive occlusal contact, premature contact. (05 Mar 2000) |
| Newton's interference colours | <microscopy> Newton's series of colours by interference results when two wave-trains of white light meet. For some wavelengths (colours) there will be destructive interference (darkness) but for other wavelengths there will be reinforcement (colour). They are most frequently observed in very thin films, only wavelengths thick, for example, oil on water. The interference is caused by partially reflected light from the interfaces. Newton's series of colours appears in sequence in the Michel-Levy chart. (05 Aug 1998) |
| differential interference contrast | <technique> A mode of contrast generation in microscopy that yields an image with a shadow relief. The relief reflects the gradient of optical path difference. Differential Interference Contrast, which is a form of interferenc microscopy that uses polarizing beam splitters, can be of the Smith or Nomarski type. Acronym: DIC (05 Aug 1998) |
| dissociation by interference | The simultaneous operation of two separate cardiac pacemaking foci that are unassociated because of interference (a normal physiologic phenomenon) due to rendering their respective territories refractory to each other. Usually atrioventricular dissociation is indicated, the rates being quite close to each other with the atrial rate slightly faster than that of the pacemaker in control of the ventricles. Capture is in either direction, usually the ventricle by the atrium, in incomplete dissociation. H Synonym: dissociation by interference. (05 Mar 2000) |
| interference | Opposition or hampering of an action or procedure. Origin: L. Ferire = to strike (18 Nov 1997) |
| interference beat | Ventricular capture in forms of A-V dissociation due to interference. (05 Mar 2000) |
| interference colours | <microscopy> Michel-Levy colour chart of birefringence/retardation vs. Thickness. (05 Aug 1998) |
| interference diffraction patterns | The patterns arising from the recombination of beams of light or other waves after they have been split and one set of rays have undergone a phase retardation relative to the other. Such patterns formed by simple objects give information on the correctness of the focus and the presence or absence of optical defects. (18 Nov 1997) |
| interference dissociation | The simultaneous operation of two separate cardiac pacemaking foci that are unassociated because of interference (a normal physiologic phenomenon) due to rendering their respective territories refractory to each other. Usually atrioventricular dissociation is indicated, the rates being quite close to each other with the atrial rate slightly faster than that of the pacemaker in control of the ventricles. Capture is in either direction, usually the ventricle by the atrium, in incomplete dissociation. H Synonym: dissociation by interference. (05 Mar 2000) |
| interference figure | <microscopy> The conoscopic pattern of extinction positions of a crystal superimposed on the pattern of interference colours corresponding to the full cone of directions by which the crystal is illuminated, each direction showing its own interference colour. (05 Aug 1998) |