| GAS | galactorrhea-amenorrhea syndrome; gastric acid secretion; gastrin; gastroenterology; general adaptat... |
|---|---|
| LAS | laboratory automation system; lateral amyotrophic sclerosis; laxative abuse syndrome; left anterior-... |
| RA | radioactive; ragocyte; ragweed antigen; rapidly adapting [receptors]; reactive arthritis; reciprocal... |
| SAID | specific adaptation to imposed demand [principle] |
| SAS | sarcoma amplified sequence; self-rating anxiety scale; short arm splint; Sklar Aphasia Scale; sleep ... |
| LD | Light-dark |
|---|---|
| LD 12:12 | light-dark cycle |
| L-D | light-dark cycle |
| condenser, dark field | <microscopy> A condenser forming a hollow cone of light with its apex (or focal point) in the plane of the specimen. When used with an objective having a numerical aperture lower than the minimum numerical aperture of the hollow cone, only light deviated by the specimen enters the objective. Objects are seen as bright images against a dark background. The ordinary bright field condenser of low power, used with a central stop, makes a good dark field condenser. They all form a dark field while illuminating the specimen with a hollow cone of light. The lower limiting aperture of the condenser must be greater than the numerical aperture of the objective with which it is to be used. Thus, no direct light enters the objective, the specimen is seen by reflected or scattered light on a dark background. See: condensers See: special dark field condensers: paraboloid, cardioid and Cassegrainian. (05 Aug 1998) |
|---|---|
| scotopic adaptation | The adjustment of the eye occurring under reduced illumination in which the sensitivity to light is greatly increased or the light threshold is greatly reduced. Dark adaptation is slower than light adaptation. During dark adaptation rhodopsin is built up in the retinal rods. (12 Dec 1998) |
| social adaptation | Adjustment to living in accordance with interpersonal, social, and cultural norms. (05 Mar 2000) |
| space adaptation syndrome | <syndrome> Alterations in normal physiology that occur during prolonged exposure to weightlessness, unless preventive measures are taken. Characterised by muscle atrophy, loss of mineral from bones, cardiovascular changes, etc. (05 Mar 2000) |
| dark-adapted eye | An eye that has been in darkness or semidarkness and has undergone regeneration of rhodopsin (visual purple), which renders it more sensitive to reduced illumination. Synonym: scotopic eye. (05 Mar 2000) |
| dark cell | Cell's in eccrine sweat glands having many ribosomes and mucoid secretory granules. (05 Mar 2000) |
| dark current | <physiology> Current caused by constant influx of sodium ions into the rod outer segment of retinal photoreceptors and that is blocked by light (leading to hyperpolarization). The plasma membrane sodium channel is controlled through a cascade of amplification reactions initiated by photon capture by rhodopsin in the disc membrane. (18 Nov 1997) |
| dark-field condenser | An apparatus for throwing reflected light through the microscope field, so that only the object to be examined is illuminated, the field itself being dark. (05 Mar 2000) |
| dark field illumination | <microscopy> Any method of illumination which illuminates the specimen but does not admit light directly to the objective. It may be by substage (dark field) condensers, by stagespot lighting, by special condensers fitted around special objectives for reflected illumination or by the slit ultramicroscope. (05 Aug 1998) |
| dark field imaging | <microscopy> Using a single diffracted beam to form the image in a transmission electron microscope. This causes all regions of the specimen not of the same crystal structure and orientation as the region which produced the diffracted beam to be represented as very dark in the final image, allowing phase differentiation visually in the transmission electron microscope. (05 Aug 1998) |
| dark-field microscope | <instrument> A microscope that has a special condenser and objective with a diaphragm or stop that scatters light from the object observed, with the result that the object appears bright on a dark background. (05 Mar 2000) |
| dark field microscopy | <procedure> A system of microscopy in which particles are illuminated at a very low angle from the side so that the background appears dark and the objects are seen by diffracted and reflected patches of light against a dark background. (18 Nov 1997) |
| dark field objective | <microscopy> Certain objectives for high-power, dark fieldwork equipped with iris diaphragms or funnel stops so that their apertures may be reduced to correspond to the dark field con-denser with which they are used. (05 Aug 1998) |
| dark field slides | <microscopy> Owing to the exacting demands of dark field illumination, not only must the microscope slide be especially clean, but also the glass of which the slide is composed must be optically clear under dark field conditions. The glass should not fluoresce. (05 Aug 1998) |
| dark field stop | <microscopy> A central stop for obtaining a dark field effect for low-power objectives. It is customarily used with a high numerical aperture, bright field condenser. (05 Aug 1998) |
| dark adaptation |
The process by which the retina becomes adapted to a luminance of less than 0.01 footlamberts.
출처: lightingdesignlab.com/library/glossary.htm
|
|---|---|
| dark adaptation |
The physical and chemical adjustments of the eye and visual system that make vision possible in low levels of illumination by increasing its sensitivity to light.
출처: www.hfeconsulting.com/Expert_Witness/GlossaryAtoD....
|
| dark adaptation |
The time taken for the rods of the retina to become active.
출처: www.spectacleworld.co.za/eyecare04.htm
|
| dark adaptation |
An essential requirement for observing astronomical objects. Dark Adaptation requires the observer to avoid direct light for at least 5 minutes prior to observing (preferably 20 minutes). The eye in total darkness will progressively develop a light sensitive pigment called Rhodopsin (a derivative of Vitamin A) which enables greater peripheral vision at night. Persons lacking in Vitamin A will suffer from "night blindness". To maintain dark adaptation during the night, avoid white light. ...
출처: www.yp-connect.net/~mmatti/_private/astronomical_d...
|