(n.) Mineral pitch; a black, tarry substance, burning with a bright flame; Jew's pitch. It occurs as an abundant natural product in many places, as on the shores of the Dead and Caspian Seas. It is used in cements, in the construction of pavements, etc. See Asphalt.
(n.) By extension, any one of the natural hydrocarbons, including the hard, solid, brittle varieties called asphalt, the semisolid maltha and mineral tars, the oily petroleums, and even the light, volatile naphthas.
Example Sentences:
(1) Tar bitumens are classifiable as the pyrolysis products of organic materials and are applied hot.
(2) The tests of bitumen, chlorcaoutchouc, asbestos cement and polyacryl delivered results comparable to those achieved under working conditions.
(3) Did these donations have anything to do with the investigation found, Clinton’s State Department approving the Alberta Clipper , a controversial pipeline carrying large amounts of tar-sands bitumen from Alberta to Wisconsin?
(4) There is also oil company interest in shale deposits at 10 locations in Morocco, two in Egypt as well as a "bitumen belt" in Nigeria which is already suffering major environmental damage from oil spills in the delta and the flaring of excess gas.
(5) But the huge amounts of water and solvents needed to extract oil from bitumen dramatically boost greenhouse gas output and, on latest production forecasts, will increase Canada’s CO2 emissions by 56 megatonnes by 2020 .
(6) The primary task is to ascertain whether tar bitumen can be replaced as a binder in paving for roads and what safety measures are practicable.
(7) Even plastics and bitumen which were used in the sphere of drinking water showed after an exposure time of three months up to 192 ml slime per square meter.
(8) The acute toxicity of three materials derived from Athabasca Oil Sands--(1) bitumen plus naphtha, (2) untreated naphtha (0-250 degrees C) and (3) synthetic crude oil (0-500 degrees C)--was assessed in a battery of tests.
(9) The relation of carbohydrate and protein content significantly changed from 2 at the beginning to 30 after 12 months of incubation the bitumen coating test plates.
(10) Since the bitumen-derived streams do not differ substantially in carcinogenic potency from petroleum-derived materials of comparable boiling range and process history, industrial hygiene practices which limit exposures to levels comparable to those observed in the petroleum-refining industry should provide similar measures of protection.
(11) Biological monitoring of exposure to bitumen fumes during road-paving operations was carried out.
(12) The exposure of sixteen road workers to bitumen fumes was studied.
(13) Time-weighted average values of bitumen fumes were determined by personal samplers.
(14) Mineral water and bitumen fraction induced an increase of the enzyme activity by 23, 20 and 45%, respectively.
(15) Bitumen plus naphtha administered at a concentration of 1.46 mg l-1 did not cause mortality in exposed rats or mice.
(16) A 2010 analysis by Accufacts Inc., an energy consulting firm that focuses on pipelines, identified Koch's Corpus Christi plant as one of 22 Gulf Coast refineries—out of more than 50—that is now capable of refining "a significant volume of blended bitumen," the type of crude that would flow through the Keystone XL.
(17) The village's fishing creek is contaminated; the school has been looted; the mangrove forests are coated in bitumen and everyone has left, refugees from a place blighted by the exploitation of the region's most valuable asset: crude oil.
(18) If the oil finds its way into those waters, the heavy tar sands bitumen will create a submerged disaster requiring a cleanup effort far above and beyond conventional responses.
(19) The carcinogenic potential of Athabasca tar sands and six experimental liquids derived from crude bitumen was evaluated utilizing the mouse epidermal carcinogenesis model.
(20) In the laboratory technique they have been using the American PIN-DEX system of pull-out necks, modelling of buttress construction without relief and together with the construction, in addition to ceramic facet making to chemical facet-making by means of composite bitumen made by KULZER, trade mark DENTACOLOR XS, which polymerize in Ultraviolet light.
Tar
Definition:
(n.) A sailor; a seaman.
(n.) A thick, black, viscous liquid obtained by the distillation of wood, coal, etc., and having a varied composition according to the temperature and material employed in obtaining it.
(v. t.) To smear with tar, or as with tar; as, to tar ropes; to tar cloth.
Example Sentences:
(1) With the exception of PMMA and PTFE, all plastics leave a very heavy tar- and soot deposit after burning.
(2) Utilizing the bilateral comparison technique in 30 hospitalized patients with chronic stable plaque-type psoriasis vulgaris, we closely monitored the clinical responses to ultraviolet radiation (Westinghouse fluorescent FS40 bulbs, 290--400 nm) and a variety of tar preparations and lubricant vehicles in combination and separately.
(3) It seems that the addition of liquid tar elevates the reaction threshold to dithranol in hypersensitive patients with psoriasis.
(4) We now present evidence that such a decrease in amounts of P68 could be essential for HIV-1 replication because of the presence of the Tat-responsive sequence (TAR sequence) present in the 5' untranslated region of HIV-1 mRNAs, which activates the P68 kinase.
(5) We conclude that there appears to be no benefit from exceeding a concentration of 5% crude coal tar in yellow soft paraffin in the treatment of patients with psoriasis and that the plateau in the dose-response curve for the action of crude coal tar in psoriasis begins at a point between 1 and 5%.
(6) Purified tat binds specifically to HIV-1 trans-activation-responsive region (TAR) RNA in gel-retardation, filter-binding, and immunoprecipitation assays.
(7) benj67 asks: How do you continue to justify continued your role in financing the Canadian tar sands, arguably a greater crime than the Libor scandal?
(8) Hansen has been an outspoken critic of tar sands, saying last year "it will be game over for the climate if development of the oil sands isn't stopped".
(9) In contrast, erythroid and myeloid colony growth from the TAR infant's marrow cells was preserved.
(10) Finally, by 6 min of heavy exercise at 8 mph 20% grade, Tar increased 2 degrees C (P less than 0.05) while Tre increased 0.5 degree C (P less than 0.05).
(11) Hydroxylamine mutagenesis was used to alter the tar gene that encodes the transmembrane Tar protein required for chemotaxis.
(12) A previously described smoking apparatus (20) was used for measurement of puff volume and inhaled tar.
(13) Again, tat protected TAR RNA from RNase A cleavage at both U23 and U31.
(14) Since its 2013 announcement, a key aim of TTIP has been to destroy regulations that prevent high-polluting tar sand crude oil from entering Europe.
(15) TARS-1 and TART-1 but not TARL-2 were transplantable into newborn syngeneic rats and nude mice.
(16) Both the occupational and in particular the therapeutic exposure to coal tar resulted in clear increases in urinary levels of PAH metabolites as compared to unexposed subjects.
(17) During the remission period the patients were advised to use a tar preparation or topical corticosteroids in the event of minor exacerbations.
(18) Biological studies have demonstrated that concentrated extract of tars from combustion of shale oil are carcingenic to the skin of mice.
(19) Beech tar, in a concentration of 5% induced a 19% increase in orthokeratosis.
(20) For the study reported in the present investigation these data have been augmented by estimates of past workplace exposure to total tar (benzene-soluble matter) and to benzo-a-pyrene (BaP).