(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.
(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.
(a.) Having the qualities of bitumen; compounded with bitumen; containing bitumen.
(1) Specified cytotoxicity and mutagenicity of coal dust extract (mixture of solvent extractions of bituminous coal nitrosated by NaNO2) were investigated because of the association of an excess risk of gastric cancer in coal miners.
(2) Samples of ash from eastern bituminous coal, western bituminous coal and mid-western bituminous coal with aerodynamic equivalent diameters of less than 15 micron were examined, and the measured emanation coefficients ranged from 0.098 down to 0.007.
(3) The polycyclic aromatic compounds (PAC) produced from the pyrolysis of a bituminous coal at temperatures of 1125 to 1425 degrees K prove to be mutagenic to S. typhimurium, both in the presence and in the absence of postmitochondrial supernatant (PMS) prepared from Aroclor 1254-induced rat liver.
(4) From a second storage tank which had been coated at the same time bituminous coating material and air samples could be taken.
(5) Significantly greater (P less than 0.05) depression (coinhibition) of viral interferon induction (greater than 83%) resulted when bioactivated B[a]P was incorporated with coal particles representative of coal rank (anthracite, bituminous, lignite, peat).
(6) Two kinds of coal mine dust, low rank with high quartz (bituminous) and high rank with low quartz (anthracite), were assayed for ability to induce alveolitis and to stimulate interleukin-1 release from normal alveolar macrophages in vitro.
(7) After the exposure of the bituminous coating material in aqua bidest.
(8) Because nonsmoking underground bituminous coal miners often have symptoms of chronic bronchitis and because a high proportion of patients with chronic bronchitis have nonspecific airway hyperreactivity, we hypothesized that coal miners would have a higher prevalence of nonspecific airway hyperreactivity than nonminer nonsmoking control subjects.
(9) In these 250 mines a progressive and five-fold increase in prevalence was observed from collieries mining low-rank (bituminous) coal to those mining coal of high ranks (anthracite and high-grade steam and coking coal).
(10) Studies with the organic solvent extracts of all five ranks of coal indicate that the extracts of bituminous, lignite, and peat, but not anthracite, induced SCEs.
(11) To determine the prevalence with which bituminous coal miners fall below the arterial tensions of both oxygen and carbon dioxide published in the Federal Register, we studied 1012 miners who had both reproducible spirometry and arterial blood gas analysis as part of their disability evaluation.
(12) Thirteen percent of impaired bituminous coal miners had acceptable pulmonary function but were eligible for black lung benefits by the blood gas guidelines.
(13) Relationships among mine and injured miner characteristics and degrees of injury are examined for 91 404 injuries in underground bituminous coal mines in the United States from 1975 through 1982.
(14) Freshly ground anthracite coal produced greater concentration of free radicals than the bituminous coal, and the radical reactivity was also greater for the anthracite.
(15) Our data indicate that, in the case of bituminous coal miners, the present federal legislation intended to identify and remunerate those who suffer lung impairment from chronic occupational exposure to coal dust is biased in favor of those who sustain additional damage to their ventilatory capacity by smoking cigarettes.
(16) Total mutagenic activity (the activity per gram of coal pyrolyzed), however, varied with coal type according to the order: high volatile bituminous much greater than subbituminous = lignite much greater than anthracite, due primarily to high organic yield during high volatile bituminous coal pyrolysis.
(17) Based upon its superior catalytic activity for H2O2 decomposition, a bituminous coal-based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods.
(18) Alveolar macrophages from bituminous coal mine dust- or titanium dioxide-exposed lungs showed increased ability to release interleukin-1 on stimulation in vitro.
(19) Similar experiments conducted with water extracts show that bituminous, lignite, and peat, but not sub-bituminous extracts, induced SCEs, and that anthracite was equivocal.
(20) At the same time, the staff of the union health plan pressed the US Public Health Service and the Pennsylvania Department of Health to investigate the prevalence of occupational respiratory diseases among bituminous miners.