chert
chert 1. Chalcedonic (see
CHALCEDONY) variety of
cryptocrystalline silica, SiO
2, that occurs as nodules or irregular masses in a sedimentary environment, often in association with black
shales and
spilites.
2. A fine-grained rock consisting of beds of cryptocrystalline silica, usually of
biogenic, volcanogenic, or diagenetic (see
DIAGENESIS) origin.
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Density dependence of ungulates and functional responses of wolves: effects on predator-prey ratios.(Statistical Data Included)
Magazine article from: Alces; 3/22/2001; ; 700+ words
; ...which integrate density-dependent growth...ungulate and wolf densities. Finally, we develop...carrying capacity, density dependence, functional...suggested that relative densities of predators and...or equilibrium density for wolves (Gasaway...ungulates to wolves. If densities of ...
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Density-dependent demography in two grasses: a five-year study.
Magazine article from: Ecology; 10/1/1995; ; 700+ words
; ...manipulations of the density of conspecific neighbors...of different natural densities on demographic parameters...indicate whether or not density dependence arising from...the direct effects of density with the effects of...Fowler 1990), Bouteloua densities were manipulated ...
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Density of conservation subdivisions reduced
Newspaper article from: The Milwaukee Journal Sentinel; 12/5/2001; ; 700+ words
; Density of conservation subdivisions reduced New...For months, the conservation subdivision density issue has been the source of sometimes...largely because of his reservations about density. Although aldermen in October approved...
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Density of prairie skinks (Eumeces septentrionalis) in old-field habitats
Magazine article from: The American Midland Naturalist; 7/1/2001; ; 700+ words
; ...ABSTRACT.-From 1996-1998 I estimated the density of prairie skinks (Eumeces septentrionalis...evaluated the influence of habitat characteristics on density. I estimated prairie skink density from a trapping grid using a mark-recapture...
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Density Changes of Iron during Morphological Healing Evolution of Internal Fatigue Microcracks
Magazine article from: Metallurgical and Materials Transactions; 12/1/2003; ; 700+ words
; ...and as-annealed specimens. The density of the specimens was measured with an electronic analytical balance. The density of the as-fatigued specimens decreased...after 2 hours of annealing time. The density of some specimens eventually approximates...
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The relative densities of pharmaceutical powders, blends, dry granulations, and immediate-release tablets
Magazine article from: Pharmaceutical Technology; 4/1/2003; ; 700+ words
; ...density or even its density heterogeneity...True (absolute) density measurement. The true or absolute densities of finely divided...Bulk (envelope) density measurement for...bulk and tapped densities of powdered excipients...
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Density-dependent fecundity by habitat heterogeneity in an increasing population of Spanish imperial eagles.
Magazine article from: Ecology; 1/1/1996; ; 700+ words
; ...territorial species, density-dependent depression...habitat quality. As densities increase, individuals...is expected between density and variance in fecundity...must increase with density, because at high densities more poor sites...
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Density: an extended investigation. (curriculum for teaching about density)
Magazine article from: Science Activities; 9/22/1996; ; 700+ words
; ...contains tables on density. Although we can easily...using values from these density tables, such activities...students should learn the densities of different substances...to develop a table of densities. Because the students...discovered the concept of density, there is no reason...
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DENSITY-DEPENDENT HABITAT SELECTION IN NIGHTINGALE (Luscinia megarhynchos C. L. B r e h m) IN SELECTED WINDBREAKS OF SW SLOVAKIA
Magazine article from: Ekológia; 7/1/2007; ; 700+ words
; ...the theory that birds at low population density occupy the most suitable habitat, whereas with increasing the density, a part of the population occupies marginal...habitats at a greater range. The population density of the nightingale (Luscinia megarhynchos...
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Mammographic Density: Use in Risk Assessment and as a Biomarker in Prevention Trials1,2
Magazine article from: The Journal of Nutrition; 10/1/2006; ; 700+ words
; ...Abstract Introduction Mammographic breast density is positively associated with risk of...and physiologic factors that can affect density readings including film exposure, positioning...alcohol intake. If mammographic breast density is to be used as a response biomarker...
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oceanic density and pressure
Book article from: The Oxford Companion to the Earth
...potential density for comparing the density of water in the deep ocean...to calculate the potential density at a comparable pressure level...if we were comparing the densities of water at a depth of 3000...to calculate the potential density relative to 3000 m, which...
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Density
Encyclopedia entry from: The Gale Encyclopedia of Science
...grams per cubic centimeter. The density of a material is also often compared to the density of water to give the material...gravities of 2 to 3, meaning they have densities of two to three times the density of water. The entire Earth has...
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density distribution within the Earth
Book article from: The Oxford Companion to the Earth
...constrains the estimates of density at all levels. If we...1980s), then M and the densities at all levels would...unaffected. The mean density is thus a scaling factor...model of the Earth's density profile were to be rescaled...controls the absolute densities in a model; C / Ma...
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Bone Density Test
Encyclopedia entry from: Gale Encyclopedia of Medicine, 3rd ed.
Bone Density Test Definition A bone density test, or scan, is designed to check for osteoporosis, a disease...age 50 die within one year. Most people today will get a bone density scan from a machine using a technology called Dual Energy X...
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Density and Volume
Book article from: Science of Everyday Things
...the interesting things about density, as distinguished from mass...in mass and volume, but the density of both samples is the same...discussed below, the known densities of various materials make it...sometimes hard to comprehend, and density requires an explanation in...
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