(n.) An important ore of iron, the sesquioxide, so called because of the red color of the powder. It occurs in splendent rhombohedral crystals, and in massive and earthy forms; -- the last called red ocher. Called also specular iron, oligist iron, rhombohedral iron ore, and bloodstone. See Brown hematite, under Brown.
Example Sentences:
(1) The third aerosol, "gamma-oxide," has a MMAD of 0.73 micrometer and has crystalline subunits 0.2 micrometer in diameter; it is a magnetic form of hematite, gamma-Fe2O3.
(2) This case-control (case-referent) study concerns a worker population with high exposure to dust of iron oxides, particularly hematite, and with some impurities of pentavalent arsenic and other metals.
(3) The iron-oxides (superfine hematite) are eroded from the Peron Sandstone exposed in some coastal cliffs and constitute up to 2% of substrate sediments near these cliffs.
(4) Inside the molluscs, lower pH conditions cause reversal of the hematite charge and the cadmium is released and accumulated by the organism.
(5) These fungi were incubated with the following iron-containing minerals: augite, hornblende, biotite, magnetite, hematite, and the igneous rock granodiorite.
(6) The "feathers" hematite has a man median aerodynamic diameter (MMAD) of 0.17 micrometer and a large surface area because it is an agglomerate of units 0.005 micrometer in diameter.
(7) Slate is a metamorphic rock comprising silica, aluminum silicates, and small amounts of chlorite, hematite, magnetite, and various carbonates.
(8) In a retrospective cohort mortality study of 10,403 Minnesota iron-ore (hematite) miners no excesses of lung cancer mortality were found among either underground (Standardized mortality ratio [SMR] = 100) or above ground (SMR = 88) miners.
(9) The "birdshot" hematite has a MMAD of 0.31 micrometer, but has a smaller surface area because the subunits are 0.03 micrometer in diameter.
(10) Fibrous dusts (chrysotile, glass fibers, nemalite, palygorscite, and gypsum) and granular dusts (actinolite, biotite, hematite, pectolite, sanidine, and talcum) were injected intraperitoneally into rats.
(11) The mortality risk of nonmalignant respiratory disease among hematite workers in the Longyan and Taochong mines of China was investigated in a retrospective cohort study covering the period 1970-1982.
(12) No direct link between the cadmium loads in molluscs and its concentration in the water or substrate sediment is evident, but the cadmium load in molluscs is usually highest where turbulence is high and the substrate sediment contains fine hematite.
(13) Iron oxides, particularly hematite, have been suspected for carcinogenic properties based on epidemiological observations and experimental data.
(14) This study reveals that cadmium in the water adsorbs extremely efficiently onto the surface of the hematite, which is negatively charged at the prevailing seawater pH of 8.15, and that suspended hematite particles are ingested by the molluscs.
Nickel
Definition:
(n.) A bright silver-white metallic element. It is of the iron group, and is hard, malleable, and ductile. It occurs combined with sulphur in millerite, with arsenic in the mineral niccolite, and with arsenic and sulphur in nickel glance. Symbol Ni. Atomic weight 58.6.
(n.) A small coin made of or containing nickel; esp., a five-cent piece.
Example Sentences:
(1) The effect of airborne pollution, especially nickel, from Kola has been studied in 10,612 persons who participated in a cardiovascular screening survey in Finnmark in 1974-75.
(2) In order to determine the specific action of cadmium on bone metabolism, the effect of cadmium on alkaline phosphatase activity, a marker enzyme of osteoblasts, was compared with that of other divalent heavy metal ions, i.e., zinc, manganese, lead, copper, nickel and mercury (10 microM each), using cloned osteoblast-like cells, MC3T3-E1.
(3) You could understand why the Met was frantic to find who had stabbed Rachel Nickell 49 times on Wimbledon Common while her screaming child looked on, but the case against Stagg was preposterous.
(4) The uptake of nickel ions by the cyanobacterium Anabaena cylindrica was studied.
(5) Nickel induced considerable increases in both glucose and glucagon levels, delayed in 19-day pregnant rats with respect to controls, and deep and permanent decreases in glycogen and amino acids in pregnant rats.
(6) The male:female prevalence of nickel allergy was 1:2 (sex difference p less than 0.001) and for chromate was 7:1 (sex difference p less than 0.001).
(7) These results suggest that nickel is unable to induce basepair or frameshift mutations in Salmonella tester strains and are discussed in relationship to the low binding affinity of Ni(II) for DNA.
(8) Titanium-nickel alloy composed of 50% by weight of each metal has unique thermal shape-memory properties, with a transition temperature of 20 degrees C. Each stent consists of one wire with a diameter of 0.9 mm.
(9) The effect of calcium(II)acetate (CaAcet) and magnesium(II) acetate (MgAcet) on nickel(II) uptake in the lungs of strain A mice and on the nickel(II)-induced changes in the pulmonary DNA synthesis were studied in order to elucidate the mechanism(s) of inhibitory action of CaAcet and MgAcet upon nickel(II) tumorigenesis.
(10) To determine cell-mediated immunity to nickel, another matrix in hard metal besides cobalt, lymphocyte transformation tests (LTT) with nickel were carried out in seven hard metal asthma patients all of who had reacted to cobalt chloride in the bronchial provocation tests (BPT).
(11) The results showed that nickel exposure led significantly to raised nickel concentration in nasal mucosa, plasma and urine both in active and retired nickel workers.
(12) Base metal alloys, principally made of nickel, chromium, and beryllium have gained widespread usage, especially in the United States, due to their lower cost and higher mechanical properties.
(13) An empirical power absorption formula developed by Haider for thermally self-regulating nickel-silicon ferromagnetic seeds has been used to calculate the seed power absorption as a function of seed temperature.
(14) The crystalline nickel sulfides and oxides that slowly dissolve in body fluids and readily enter cells by phagocytosis tend to be most active in producing morphological transformation of SHE cells in vitro and stimulating erythrocytosis and carcinogenesis following ir administration to rats.
(15) The nickel-titanium wires, however, showed a clear deviation form the linearity with a curviform course.
(16) After 3 and 6 months exposure to metallic nickel the macrophages were 'overfed' and inactive.
(17) Nickel deficiency was produced in chicks under near optimal growth conditions.
(18) However, nickel also induces a direct decrease in the release of lysozyme activity by AM.
(19) The hyperglycaemic response to nickel of female rats was more marked than that of males, with an increase in intracellular glucose, more marked during pregnancy, which even surpassed the plasma concentration of glucose.
(20) A nickel subsulfide (Ni3S2) lung tumor model for the study of metal carcinogenesis was evaluated using intratracheally dosed B6C3F1 mice.