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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Annals of the Institute of Statistical Mathematics 40 (1988), S. 407-418 
    ISSN: 1572-9052
    Keywords: Incidence matrix ; C-matrix ; eigenvalue ; E-optimality ; MV-optimality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper we consider the problem of determining and constructing E- and MV-optimal block designs to use in experimental settings where ν treatments are applied to experimental units occurring in b blocks of size k, k≥ν. It is shown that some of the well-known methods for constructing E- and MV-optimal unequally replicated designs having ν≥k fail to yield optimal designs in the case where ν〈k. Some sufficient conditions are derived for the E- and MV-optimality of block designs having ν〈k and methods for constructing designs satisfying these sufficient conditions are given.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Studia logica 47 (1988), S. 233-241 
    ISSN: 1572-8730
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Philosophy
    Notes: Abstract We prove a finite model theorem and infinitary completeness result for the propositional μ-calculus. The construction establishes a link between finite model theorems for propositional program logics and the theory of well-quasi-orders.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 5 (1988), S. 323-327 
    ISSN: 1432-0789
    Keywords: Earthworm ; Aporrectodea rosea ; Axial pressure ; Tunnelling ; Burrowing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The axial forces generated by the earthworm Aporrectodea rosea were measured by directing the earthworm to tunnel into soil discs mounted on an electronic balance connected to a datalogger. The area over which the force acted was estimated from the size of the hole created by the tunnelling. The maximum force recorded by an individual worm was 0.760 N and the mean maximum value was 0.465 N. The maximum pressures recorded was 116.5 kPa, while the mean maximum pressure was 72.8 kPa. These axial pressures are approximately one-tenth of the maximum axial pressure recorded for plant roots. The statistical distribution of activity as the worms tunnelled through the soil discs was analysed. Pressures recorded were well in excess of physiologically measured pressures and the generation of forces within muscles to achieve these pressures was calculated by some assumptions. It was estimated that there is a maximum tension in the circular muscles of 0.15 N per segment of the worm.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 5 (1988), S. 328-332 
    ISSN: 1432-0789
    Keywords: Earthworm ; Aporrectodea rosea ; Radial Pressure ; Tunnelling ; Indirect tension test ; Maximum force
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The radial pressures generated by the earthworm Aporrectodea rosea were measured in a study of the conditions under which the worms were able to crack soil discs into which they were encouraged to tunnel. The tensile strength of replicate discs was determined by indirect tension tests and by expansion of rubber membranes in soil discs. Simple engineering theory was used to relate the stress required to fracture a disc with the applied internal stress. Mean values for the radial stress applied by the earthworms in tunnelling through the discs was 230 kPa. With some assumptions about the distribution of muscles across the worm diameter, it was estimated that the mean maximum force generated by all the longitudinal muscles in any segment was 3.2 N.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 5 (1987), S. 152-157 
    ISSN: 1432-0789
    Keywords: Earthworm Casts ; “Modexi” ; Shape ; Tensile strength ; Pressure ; Aporrectodea rosea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Some physical properties of casts of the earthworm Aporrectodea rosea were examined and compared with the properties of aggregates from the bulk soil. Cast shape was quantified by three ratio methods and two mathematical spectra methods, using data obtained by two-dimensional scanning. Shapes were compared with previously published descriptions of “modexi”. The tensile strength of dry casts was measured by the indirect tension method and was found to be approximately 2.5 times greater than that of dried aggregates of similar size. Tensile strengths are used to predict that beds of casts are less compactable than beds of aggregates. From relationships between soil water content, matric potential and undrained shear strength of fresh earthworm casts, the mean pressure applied to soil as it is remoulded by passing through the earthworm gut is estimated to be 259 Pa.
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  • 6
    ISSN: 1432-0789
    Keywords: Biopores ; Root growth ; Transpiration ; Simulations ; Mechanical impedance ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The use of vertical biopores by wheat (Triticum aestivum) seminal roots for easy access to the subsoil and the consequences for plant water supply and yield has been investigated by computer simulation. Parameters included were: biopore density and diameter, depth of cultivation and strength of the subsoil — all under a wide range of seasonal weather conditions. The model predicts that biopores add significantly to root penetration at depth, even at a density of 0.1% v/v of small, vertical pores, while 1.5% to 2.0% v/v can ensure maximum root penetration. When the growing season is shorter a larger number of biopores is needed to ensure timely root penetration to depth. With shallow tillage, biopores occur closer to the soil surface, and their importance is increased. Deeper root penetration invariably gives greater water uptake and transpiration, but may have a negative effect on grain yield, especially under the driest climatic conditions. An increase in early water use may result in less soil water being available during the grain-filling period. The effect of biopores on plant transpiration varies from year to year, depending on the amount of rain and its distribution in time, and on the amount of soil water stored at time of sowing.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 90 (1985), S. 410-410 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 98 (1988), S. 40-48 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract In recent years, there have been numerous calibrations of the biotite-garnet Fe-Mg exchange geothermometer. The Eastern Lac Seul region of the English River subprovince, Ontario, provides an excellent field area in which to compare these calibrations. Trend surface analysis using the temperatures obtained from garnet cores and matrix biotites-showed almost identical trends in the eastern Lac Seul region regardless of the calibration used. The absolute temperatures and the precision of each calibration do, however, show large variation. Geothermometers based solely on lnKD were found to give more precise results than the calibrations that attempt to incorporate non-Fe-Mg components. The Perchuk and Lavrent'eva (1983) thermometer yields the most precise and accurate results. If a sufficient number of samples are collected over a region, it can be used to estimate metamorphic temperature trends to ±30° C. Metamorphism and migmatization of the English River subprovince occurred during the Kenoran orogeny, 2.68 b.y. ago. Our results show that a “thermal anticline” has been preserved, with temperatures of ∼ 600° C at the north and south contacts with Uchi and Wabigoon Greenstone belts, increasing to ∼ 725 °C at the center of the subprovince. A garnet-cordierite “in” isograd occurs at ∼650° C and an orthopyroxene “in” isogradat ∼700° C.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 102 (1989), S. 247-254 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The methamorphic history of the Patapedia thermal zone, Gaspé, Quebec, is re-evaluated in the light of results obtained from a study of fluid inclusions contained in quartz phenocrysts of felsic dyke rocks. The thermal zone is characterised by calc-silicate bodies that have outwardly telescoping prograde metamorphic isograds and display extensive retrograde metamorphism with associated copper mineralization. Three distinct fluid inclusion types are recognized: a low to moderate salinity, high density aqueous fluid (Type I); a low density CO2 fluid (Type II); and a high salinity, high density aqueous fluid (Type III). Fluid inclusion Types I and II predominate whereas Type III inclusions form 〈10% of the fluid inclusion population. All three fluid types are interpreted to have been present during prograde metamorphism. Temperatures and pressures of metamorphism estimated from fluid inclusion microthermometry and isochore calculations are 450°–500° C and 700–1000 bars, respectively. A model is proposed in which the metamorphism at Patapedia was caused by heat transferred from a low to moderate salinity fluid of partly orthomagmatic origin (Type I inclusions). During the early stages, and particularly in the deeper parts of the system, CO2 produced by metamorphism was completely miscible in the aqueous hydrothermal fluid and locally resulted in high XCO2 fluids. On cooling and/or migrating to higher levels these latter fluids exsolved high salinity aqueous fluids represented by the Type III inclusions. Most of the metamorphism, however, took place at temperature-pressure conditions consistent with the immiscibility of CO2 and the hydrothermal fluid and was consequently accompanied by the release of large volumes of CO2 vapour which is represented by Type II inclusions. The final stage of the history of the Patapedia aureole was marked by retrograde metamorphism and copper mineralization of a calcite-free calc-silicate hornfels in the presence of a low XCO2 fluid.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 89 (1985), S. 69-80 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Recent experimental, theoretical, and thermodynamic studies permit better calibration of two reactions for geobarometry: grossular+pyrope+quartz=anorthite+enstatite grossular+almandine+quartz=anorthite+ferrosilite If both reactions are applied using the same thermodynamic data and activity models they should yield the same pressure for a given garnet-pyroxene-plagioclase-quartz assemblage. Application to a variety of high-grade terrains generally yielded excellent results. However, poor results have been obtained for high-Fe rocks which can be traced to errors in activity models for garnet and/or pyroxene. Either a two-site ideal mixing model for orthopyroxene (cf. Wood and Banno 1973) underestimates enstatite activity for high-Fe orthopyroxenes or the Ganguly and Saxena (1984) model overestimates pyrope activity in low-Mg garnets. Application of both barometers to a variety of high-grade terrains gives the following average pressures: Terrain Mg-reaction Fe-reaction Adirondacks, New York 11.2 8.0 Buksefjorden, Greenland 9.5 8.89 Doubtful Sound, New Zealand 12.6 12.0 Enlish River subprovince, Ontario 4.7 5.4 Furua Complex, Tanzania 10.8 10.6 Granite Falls, Minnesota 5.3 6.9 Huntley-Portsoy, Scotland 3.8 4.1 Inarijärvi Complex, Finland 6.0 6.7 Indian Shield 8.9 9.5 Kapuskasing Zone, Ontario 7.8 8.2 Lachnagar, Scotland 3.9 2.6 Molodezhnaya Station, Antartica 7.1 7.5 Nain Province, Labrador 3.6 1.6 Otter Lake, Quebec 9.3 7.7 Qianxi Country, China 11.0 10.7 The above pressures are, in general, in excellent agreement with previous estimates. The results for the English River subprovince and for the Minnesota River Valley further support the idea that the Archean crust was, in some areas, in excess of 20 km thick.
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