| hard rays | Ray's of short wavelength and great penetrability. (05 Mar 2000) |
|---|---|
| hard science | A field of scientific study which involves precise measurements of observations and well-defined methods for obtaining and interpreting new knowledge. Chemistry and physics are definitely hard sciences, biology, geology, and astronomy also are usually thought of as hard sciences. Psychology, sociology, and anthropology are not, and are considered soft sciences. (09 Oct 1997) |
| hard soap | A soap made with olive oil, or some other suitable oil or fat, and sodium hydroxide; used as a detergent, and in the form of a suppository or soapsuds enema for constipation; used also as an excipient in pills. Synonym: Castile soap. (05 Mar 2000) |
| hard sore | The primary skin lesion of syphilis which begins at the site of infection after an interval of 10-30 days as a papule or red ulcerated skin lesion. (27 Sep 1997) |
| hard tarter | <dentistry> A calcium salt concretion which forms on your teeth. Calculus deposits form on the teeth in areas which you do not floss or brush. If these concretions are left to build up on the tooth enamel, they will irritate the gum tissue, push it away from the tooth and promote progressive bone loss. Eventually the teeth can loosen and fall out. These deposits can be removed by a dentist or a dental hygienist on an annual to biannual basis. (27 Sep 1997) |
| hard tissue | Tissue that has become mineralised, tissue having a firm intercellular substance, e.g., cartilage and bone. (05 Mar 2000) |
| hard tubercle | A tubercle lacking necrosis. (05 Mar 2000) |
| hard ulcer | <dermatology> The primary skin lesion of syphilis which begins at the site of infection after an interval of 10-30 days as a papule or red ulcerated skin lesion. (27 Sep 1997) |
| hard water | <chemistry> Hard water is water which contains minerals like calcium carbonate, magnesium carbonate, bicarbonates, sulphates, or chlorides, because it has been exposed to rocks or rocky soils. Hard water can corrode, discolour, or deposit its minerals, in and around materials such as water pipes. (09 Oct 1997) |
| allergic contact dermatitis | A delayed type IV allergic reaction of the skin with varying degrees of erythema, oedema, and vesiculation resulting from cutaneous contact with a specific allergen. Synonym: contact allergy. (05 Mar 2000) |
| balancing contact | The contact's between upper and lower dentures on the balancing or mediotrusive side for the purpose of stabilizing the dentures, the contact's between upper and lower dentures at the opposite side from the working or laterotrusive side (anteroposteriorly or laterally) for the purpose of stabilizing the dentures, the contact's between upper and lower natural or artificial teeth at the opposite side from the working or laterotrusive side. Synonym: balancing occlusal surface. (05 Mar 2000) |
| centric contact | The relation of opposing occlusal surfaces which provides the maximum planned contact and/or intercuspation, the occlusion of the teeth when the mandible is in centric relation to the maxillae. Synonym: centric contact. (05 Mar 2000) |
| microradiography, contact | <microscopy> A method of making micrographs by means of X-rays. The specimen is placed close to a fine-grained photographic emulsion at some distance from the X-ray source. The X rays pass through the specimen and the differential absorption and the scattering of the radiation is recorded by the emulsion. The resulting negative is examined and photographed through a light microscope. (05 Aug 1998) |
| close contact infection | <epidemiology> An infection which requires close contact, other than sexual contact, between susceptible and infectious individuals, for transmission. (05 Dec 1998) |
| contact | A mutual touching of two bodies or persons. Origin: L. Contactus = a touching together (18 Nov 1997) |