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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 34 (1996), S. 0 
    ISSN: 1745-6584
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Energietechnik , Geologie und Paläontologie
    Notizen: Site selection for ground-water production wells was made easier using a microgravity survey technique. The ground-water regime beneath the Carleton University campus is dominated by fracture flow associated with major faults. These faults are located within buried bedrock valleys where preferential erosion of the bedrock has occurred. A series of faults is inferred from bedrock topography and hydrogeological testing; however, the precise orientation of the faults is to a large extent uncertain. The bedrock surface is masked by fluvial, glacial, and glaciomarine overburden of variable thickness.High precision, small-scale microgravity profiling was carried out to identify the bedrock valleys. Gravity anomalies of up to 0.05 mgal correspond to valley depths ranging from 5 to 15 meters. The density contrast between overburden and limestone bedrock is estimated as 0.3 g/cm3. Forward modeling using a polygon technique suggests that the observed, corrected gravity profile is a smoothed reflection of the bedrock surface at depth.Based on the locations of the bedrock valleys, several faults were identified and four test wells were drilled as part of the development of Phase 2 of the Carleton Groundwater Energy Project. Three of these wells produced high yields, exceeding 60 I/sec, when converted to 12 inch diameter production wells. The fourth well also encountered a bedrock valley but with a slightly lower yield of water.The favorable drilling results have shown that small-scale microgravity profiling, in an area that is largely unsuitable for the detection of subsurface features using other geophysical techniques, is an effective method for imaging the bedrock surface. The positions of the faults, which are known to exist on the basis of stratigraphy, geophysical well log correlations, bedrock topography, and calcite-filled fractures exposed in outcrop or core, have been more accurately defined.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 45 (1980), S. 0 
    ISSN: 1750-3841
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Unadjusted percentage reflectance ratios or differences at 630 nm/580 nm, 507 nm/572 nm, 572 nm/525 nm, 630 nm — 580 nm and K/S adjustment of 572 nm/525 nm and 507 nm/572 nm showed high pooled within-cell correlation coefficients to visual color scores of beef muscles displayed under 1076 lumens/m2 Deluxe Warm White lighting at 2°C up to 5 days. Adjusting reflectance to K/S did not improve correlation coefficients. Multiple regression analysis showed that %R 630 nm —%R 580 nm contributed most to R2 of prediction equations in three of four beef muscles studied. Use of %R 630 nm —%R 580 nm is recommended.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 217 (1968), S. 777-778 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Considerable day-to-day variation in the pattern of rumen fermentation (as measured by the molar proportions of steam volatile fatty acids present in the rumen liquor) has been observed in this laboratory, especially on diets low in fibre content. It has been postulated that this variation can be ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 50 (1994), S. 727-732 
    ISSN: 1420-9071
    Schlagwort(e): Trout ; killifish ; rod photoreceptor shedding ; sunrise
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Diurnal shedding by retinal rods was studied in wild cutthroat trout,Oncorhyncus clarki, hatchery rainbow trout,Oncorhyncus mykiss, and the plains killifish,Fundulus zebrinus, by counting the shed tips of rod outer segments ingested as ‘phagosomes’ by pigment epithelial cells. After sunrise, phagosomes increased in all species, but fewer occurred in trout, and these were elevated from 3 to 9 hours after sunrise. Shedding occurred earlier in the light period and was more robust in killifish, with phagosomes elevated from 1.5 to 6 hours after sunset. The data suggest that both production of phagosomes by shedding and their subsequent disposal are slower at the lower temperatures experienced by trout. Otherwise, rod shedding produced under natural lighting is not appreciably different than that provoked by sudden onset of artificial light.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    facet.materialart.
    Unbekannt
    London : Periodicals Archive Online (PAO)
    RSA Journal. 121:5206 (1973:Sept.) 634 
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Environmental geology 39 (2000), S. 767-773 
    ISSN: 1432-0495
    Schlagwort(e): Key words Stable isotopes ; Acid rock drainage ; Mining effluent ; Geochemical mixing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract  Oxygen-18 (18O) and deuterium (D, or 2H) are routinely used in hydrologic, climatologic and geothermal studies. In hydrology, stable isotopes provide information on the type and topology (altitude and latitude) of the recharge waters and the historical effects on water, related to such physical processes as evaporation (in ponds), melting (of snow or ice), condensation, evapotranspiration and mixing. In geothermal studies, stable isotopes provide key information related to recharge and the various temperature-dependent water/rock isotope exchange reactions. The latter is assessed through the oxygen shift in the 18O/D correlation. At acid rock drainage (ARD) sites, water/rock interactions are primarily controlled by pH and oxidation potential. Using the isotopic characteristics of the rocks and the recharge waters as a basis, the relative oxygen shift of the ARD effluent can provide information on: (1) the residence time, (2) the rate of water/rock reactions, and (3) the actual pH at the rock/water interface. This paper offers a methodology for conducting oxygen and hydrogen isotope studies related to ARD and other mineral effluent problems. The methodology is based on: (1) comprehensive sampling of regional waters, ARD effluent and major contributing minerals and rocks, (2) isotopic and elemental analysis, and (3) data interpretation on the basis of a zero-dimensional (mass balance), multi-component mixing model.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Environmental geology 39 (2000), S. 937-944 
    ISSN: 1432-0495
    Schlagwort(e): Stable isotopes ; Hydrochemistry ; Acid rock drainage ; Tailings pond leakage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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