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Page 6385, results 159601 - 159625

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Thermochemical study of the system Fe-As-S
P. B. Barton Jr.
1969, Geochimica et Cosmochimica Acta (33) 841-857
The results of Toulmin and Barton (1964) for the Fe-S system have been combined with a series of new measurements on As-bearing assemblages in the 500°–850°C temperature range to derive data on the free energies, enthalpies, and entropies of formation for arsenopyrite, loellingite, orpiment, realgar,...
Atomic-absorption determination of rhodium in chromite concentrates
Marian Moeller Schnepfe, F.S. Grimaldi
1969, Talanta (16) 1461-1465
Rhodium is determined in chromite concentrates by atomic absorption after concentration either by co-precipitation with tellurium formed by the reduction of tellurite with tin(II) chloride or by fire assay into a gold bead. Interelement interferences in the atomic-absorption determination are removed by buffering the solutions with...
The determination of nanogram amounts of Chromium in urine by x-ray fluorescence spectroscopy
K. Beyermann, H.J. Rose Jr., R.P. Christian
1969, Analytica Chimica Acta (45) 51-55
Nanogram amounts of chromium can be extracted as oxinate into chloform. By treatment of the chloroform layer 3 M hydrochloric acid, oxinates of other elements and excess of reagent are removed, leaving a chloroform solution of the chromium chelate only. This solution is concentrated and transferred to...
Shock and thermal metamorphism of basalt by nuclear explosion, Nevada test site
O.B. James
1969, Science (166) 1615-1620
Olivine trachybasalt metamorphosed by nuclear explosion is classified into categories of progressive metamorphism: (i) Weak. Plagioclase is microfractured, and augite cotainis fine twin lamellae. (ii) Moderate. Plagioclase is converted to glass, and mafic minerals show intragranular deformation (undulatory extinction, twin lamellae, and, possibly, deformation lamellae), but rock texture is preserved....
Paleozoic tectonic history of the Arctic basin north of Alaska
Michael Churkin Jr.
1969, Science (165) 549-555
The geology of the margin of the Canada Basin, together with geophysical data, leads me to reject the continental subsidence theory for the origin of the deep Canada Basin. Instead, the Canada Basin is, I believe, a true and probably very ancient ocean basin floored by oceanic crust and rimmed...
The isotopic composition of lead in potassium feldspars from some 1.0-b.y. old North American igneous rocks
Robert Eugene Zartman, G.J. Wasserburg
1969, Geochimica et Cosmochimica Acta (33) 901-942
The isotopic composition of lead and the uranium, thorium and lead concentrations in potassium feldspars are determined for more than 30 1.0-b.y. old North American igneous rocks. Samples representing a broad spectrum in petrographic type and mode of occurrence were chosen; an effort was made to include only rocks having...
Pecoraite, Ni6Si4O10(OH)8, nickel analog of clinochrysotile, formed in the wolf creek meteorite
G. T. Faust, J. J. Fahey, B. Mason, E.J. Dwornik
1969, Science (165) 59-60
Pecoraite is a new phase in the natural system H2O-NiO-MgO- SiO2, the nickel analog of clinochrysotile. It occurs in cracks in the Wolf Creek meteorite in Australia where it was formed under hydrothermal conditions. Particles of pecoraite are very small curved plates which have begun to coil; some have achieved...
Loss of uranium from crystallized silicic volcanic rocks
J.N. Rosholt, D. C. Noble
1969, Earth and Planetary Science Letters (6) 268-270
Dense primarily crystallized silicic groundmass material from two welded ash-flow units and one lava flow of Tertiary age from the Western United States contain only 20 to 60 percent of the uranium present in nonhydrated glass from the rock units. These differences reflect...
Extraction of vanadium into isobutyl methyl ketone
Hans J. Crump-Wiesner, W.C. Purdy
1969, Talanta (16) 124-129
Because of its advantages in atomic-absorption spectroscopy, isobutyl methyl ketone was chosen as organic solvent for an extraction study on vanadium. Of eight chelating agents which were evaluated for completeness of extraction, ease of use, working pH range, and freedom from interference, cupferron was judged best.<div...
Lithium and potassium absorption, dehydroxylation temperature, and structural water content of aluminous smectites
Leonard Gene Schultz
1969, Clays and Clay Minerals (17) 115-149
X-ray analysis of Li+- and K+-saturated samples, differential thermal analysis (DTA), thermal gravimetric analysis (TGA), and chemical analysis of 83 samples enable a distinction to be made between Wyoming, Tatatilla, Otay, Chambers, and non-ideal types of montmorillonite, and between ideal and non-ideal types of beidellite. The Greene-Kelly Li+-test differentiates between...
Aging small Canada geese by neck plumage
Kenneth F. Higgins, Lyle J. Schoonover
1969, Journal of Wildlife Management (33) 212-214
The neck plumage method, a new technique for separating immature from adult Canada geese (Branta canadensis) in the hand, was evaluated by comparison with the notched tail feather and cloacal examination methods. Two (1.4 percent) of 141 geese examined were misaged, resulting in a 6 percent error in the immature-adult...
Survival in wood duck broods
Frank B. McGilvrey
1969, Journal of Wildlife Management (33) 73-76
Mortality of wood ducklings (Aix sponsa) from hatching to 6 weeks of age averaged 47 percent during a 4-year study at the Patuxent Wildlife Research Center. Over 90 percent of the total mortality occurred during the first 2 weeks of life. Brood bonds began to dissolve after the fifth week....
Glaciers and water supply
Mark Frederick Meier
1969, Journal American Water Works Association (61) 8-12
Glaciers are one of the few large sources of water supply that remain unexploited. With the advance of civilization into the subpolar regions, a better understanding of glacier hydrology becomes increasingly important....
Mallard hatching from an egg cracked by freezing
Raymond J. Greenwood
1969, The Auk (86) 752-754
The eggs of early-nesting waterfowl in North Dakota are frequently exposed to subfreezing temperatures. Mallards (Anas platyrhynchos) and Pintail (Anas acuta), normally the first ducks to arrive in the spring, begin limited early nesting in min-April. Nighttime temperatures during this period frequently drop below freezing, and late spring blizzards are...
Geologic history of the Colorado River: Chapter C in The Colorado River region and John Wesley Powell (Professional Paper 669)
Charles Butler Hunt
1969, Professional Paper 669-C
John Wesley Powell clearly recognized that the spectacular features of the Colorado River - its many grand canyons - were dependent upon the structural history of the mountainous barriers crossed by the river. He conceived of three different historical relationships between rivers and structural features: (1) Newly uplifted land surfaces...
John Wesley Powell: Pioneer statesman of federal science: Chapter A in The Colorado River region and John Wesley Powell (Professional Paper 669)
Mary C. Rabbitt
1969, Professional Paper 669-A
In the middle decades of the 19th century, American science matured rather rapidly. The general scholar with an interest in natural history gave place to the specialist in a particular science, and the various sciences themselves became distinct from each other and from the general body of knowledge. The geological...
Landscape esthetics: How to quantify the scenics of a river valley
Luna Bergere Leopold
1969, Natural History 37-44
There are an increasing number of bills before Congress that in one way or another affect the landscape or the environment. Each of these requires seemingly endless numbers of congressional hearings, which are recorded upon endless reams of paper.And if, for some reason, you happen to read the voluminous testimony...