What's the difference between density and refraction?

Density


Definition:

  • (n.) The quality of being dense, close, or thick; compactness; -- opposed to rarity.
  • (n.) The ratio of mass, or quantity of matter, to bulk or volume, esp. as compared with the mass and volume of a portion of some substance used as a standard.
  • (n.) Depth of shade.

Example Sentences:

  • (1) It is suggested that the Japanese may have lower trabecular bone mineral density than Caucasians but may also have a lower threshold for fracture of the vertebrae.
  • (2) Ca2+ transport was positively correlated with MR cell density.
  • (3) Osteoporosis is characterized by a reduction in bone density.
  • (4) However, four of ten young adult outer arm (relatively sun-exposed) and one of ten young adult inner arm (relatively sun-protected) fibroblasts lines increased their saturation density in response to retinoic acid.
  • (5) We report a series of experiments designed to determine if agents and conditions that have been reported to alter sodium reabsorption, Na-K-ATPase activity or cellular structure in the rat distal nephron might also regulate the density or affinity of binding of 3H-metolazone to the putative thiazide receptor in the distal nephron.
  • (6) In schizophrenic patients the density of dopamine uptake sites in the basal ganglia was slightly reduced, mainly in the middle third of putamen.
  • (7) Size analysis of the solubilized IgA IP employing sucrose density gradient ultracentrifugation, indicated that these were heterogeneous, with a size generally larger than 19 S.
  • (8) Estimates of the risk probability for each dose level and sacrifice time are found utilizing the sample likelihood as the posterior density.
  • (9) We report on a patient, with a CT-verified low density lesion in the right parietal area, who exhibited not only deficits in left conceptual space, but also in reading, writing, and the production of speech.
  • (10) The compressive strength of bone is proportional to the square of the apparent density and to the strain rate raised to the 0.06 power.
  • (11) We assessed changes in brain water content, as reflected by changes in tissue density, during the early recirculation period following severe forebrain ischemia.
  • (12) Macrophages internalize aggregated low density lipoprotein (LDL) by LDL receptor-dependent phagocytosis.
  • (13) The capillary-adipocyte distances were shorter and the vascularization density was higher in old rats.
  • (14) By means of computed tomography (CT) values related to bone density and mass were assessed in the femoral head, neck, trochanter, shaft, and condyles.
  • (15) When compared with nonspecialized regions of the cell membranes, these contact sites were characterized by a decreased intercellular distance, subplasmalemmal densities and coated pits.
  • (16) Furthermore, high-density catalase-positive--but not catalase-negative--E. coli can survive and multiply in the presence of competitive, peroxide-generating streptococci.
  • (17) The deep cerebellar nuclei were moderately labeled at birth and gradually decreased in density thereafter.
  • (18) In spite of important differences in size, chemical composition, polymer density, and configuration, biological macromolecules indeed manifest some of the essential physical-chemical properties of gels.
  • (19) It is especially efficacious in evaluating patients with cystic lesions, especially those with complex cysts not clearly of water density.
  • (20) These observations suggest that the liver secretes disk-shaped lipid bilayer particles which represent both the nascent form of high density lipoproteins and preferred substrate for lecithin-cholesterol acyltransferase.

Refraction


Definition:

  • (n.) The act of refracting, or the state of being refracted.
  • (n.) The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a different density from that through which it has previously moved.
  • (n.) The change in the direction of a ray of light, and, consequently, in the apparent position of a heavenly body from which it emanates, arising from its passage through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction.
  • (n.) The correction which is to be deducted from the apparent altitude of a heavenly body on account of atmospheric refraction, in order to obtain the true altitude.

Example Sentences:

  • (1) In the group of high myopia (over 20 D), the mean correction was 13.4 D. In the group with refraction between 0 and 6 D, 88% of the eyes treated had attained a correction between -1 and +1 D 3 months postoperatively.
  • (2) The molar refractivity has been shown to be a superior parameter for the description of the activity of sulphonamides than the sum of electronegativities of atoms making up a heterocyclic substituent in the sulphonamide molecule and molecular weight of the substituent.
  • (3) A new approach is presented to the refractive procedure by adding observation, both surreptitious and direct, as an adjunct, an aid and a supplement to differential diagnosis in a refractive examination and in visual analysis.
  • (4) Dioptric aniseikonia was calculated between 1 month and 24 months after surgery (with Gruber's and Huber's computer program) on the basis of most recently obtained values (bulb axis length, depth of the anterior chamber, lens thickness, necessary refraction), and compared with subjective measurements taken with the phase difference haploscope.
  • (5) These versions offer different advantages and are selected according to the particular field of application and the refraction of the surgeon.
  • (6) The refraction of his mild hyperopic eyes (+0,5 dpt) changed to -5,5 dpt and the intraocular pressure increased to 40 mm Hg in the right and 42 mm Hg in the left eye.
  • (7) These observations suggest that refractive anomalies such as anisometropia that limit high frequency spatial resolution and binocular integration can present a major obstacle to the postnatal development of binocular vision.
  • (8) A retrospective study was performed to evaluate the effect of recipient-donor trephine disparity on refractive error and corneal curvature post-suture removal in keratoconus.
  • (9) Scientists and clinicians concerned with underwater vision have not considered the relationship between chromatic aberration, water color, and the refractive state of the eye.
  • (10) As the refractive status changes a curve is traced out on the graph.
  • (11) The change in refractive astigmatism was as high as 1.50DC (diopter cylinder).
  • (12) There is a problem in this approach if the angle between the direction of tracked beam and the direction of tracking translation is not zero due to refraction or other effects.
  • (13) We find good agreement between the model calculations and the experimental results indicating that edge birefringence can be attributed to the change in polarization of light that is refracted and reflected by dielectric interfaces.
  • (14) The corneal sensibility was examined with the aesthesiometer of Draeger in 41 patients after refractive corneal surgery, 31 patients after radial keratotomy, 5 after epikeratophakia, 5 after excimer laser ablation.
  • (15) Extraordinarily wide angles were observed in all cases and myopia was a common refractive error.
  • (16) There was no connection between the cholesterol level, refraction or visual acuity.
  • (17) The refractive changes in 84 children (155 eyes) following horizontal strabismus surgery and in 97 children (181 eyes) without surgical intervention were studied.
  • (18) Refractive error and the ocular refractive components have heritabilities intermediate between zero and one, as complied from several studies, indicating familial resemblance, but also non-genetic variation.
  • (19) Approximately 75% of repeat autorefractor measurements were within 0.50 D of the initial readings, and about 75% of measurements were within 1.00 D of the manual refractions.
  • (20) The refractive index profile in the equatorial plane of bovine lenses from over a wide age range is presented.