Optical spectrum based measurement of flotation slurry contents   总被引：1，自引：1，他引：0  

Olli Haavisto  Jani Kaartinen  Heikki Hytyniemi 《International Journal of Mineral Processing》2008,88(3-4):80-88

Monitoring and control of a flotation circuit is mainly based on the information gained by assaying the process slurry lines. In flotation plants, usually an X-ray fluorescence analyzer is used to obtain the on-line assays. This article introduces the visual and near-infrared reflectance spectroscopic analysis of the process slurries as a supplementary method which complements the on-line assay information available from an X-ray fluorescence analyzer. It is shown that the spectral information can be used to accurately predict the element contents in the slurry in between successive XRF analyses. Since the spectral measurements can be taken with high frequency as opposed to the sparse X-ray fluorescence analysis, a practically continuous on-line estimate of the slurry contents is reached. These estimates can be used in the plant control to improve the overall performance of the circuits and to yield also economical savings. Additionally, the frequent monitoring of the grades can provide means to eliminate rapid disturbances in the circuits, thus improving the stability of the process.  相似文献   

A general method for calculating three-dimensional laminar and turbulent boundary layers on ship hulls     

Tuncer Cebeci  K.C. Chang  Kalle Kaups 《Ocean Engineering》1980,7(2):229-280

A general method for representing the flow properties in the three-dimensional boundary layers around ship hulls of arbitrary shape is described. It makes use of an efficient two-point finite-diffirence schem to solve the boundary-layer equations and includes an algebraic eddy-viscosity representaion of the Reynolds-stress ternsor. The numericzal method contains novel and desirable features and allows the calculation of flows in which the circumferential velocity component contains regions of flow reversal across the boundary layer. The inviscid pressure distribution is determined with the Douglas-Neumann method which, if necessary, can conveniently allow for the boundary-layer displacement surface. To allow its application to ships, and particularly to those with double-elliptic and flat-bottomed hulls, a non-orthogonal coordinate system has been developed and is shown to be economical, precise and comparatively easy to use. Present calculations relate to zero Froude number but they can be extended to include the effects of a water wave and local regions of flow separation which may stem from bulbous-bow geometries.  相似文献   

Climate and Water: From Climate Models to Water Resources Management and Vice Versa   总被引：4，自引：0，他引：4  

Olli Varis  Tommi Kajander  Risto Lemmelä 《Climatic change》2004,66(3):321-344

This article reviews the recent developments in the functional chain from climate models to climate scenarios, through hydrology all the way to water resources management, design and policy making. Although climate models, such as Global Circulation Models (GCMs) continue to evolve, their outputs remain crude and often even inappropriate to watershed-scale hydrological analyses. The bridging techniques are evolving, though. Many families of regionalization technologies are under progress in parallel. Perhaps the most important advances are in the field of regional weather patterns, such as ENSO (El Niño-Southern Oscillation), NAO (North Atlantic Oscillation) and many more. The gap from hydrology to water resources development is by far not that wide. The traditional and contemporary practices are well in place. In climate change studies, the bottleneck is not in this link itself but in the climatic input. The tendency seems to be towards integrated water resources assessments, where climate is only one among many changes that are expected to occur, such as demography, land cover and land use, economy, technologies, and so forth. In such a pragmatic setting a risk–analytic interpretation of those scenarios is often called for. The above-outlined continuum from climate to water is a topic where the physically based modelers, the empiricists and the pragmatists should not get restricted to their own way of thinking. The issues should develop hand in hand. Perhaps the greatest challenge is to incorporate and respect the pragmatic policy-related component to the two other branches. For this purpose, it is helpful to reverse the direction of thinking from time to time to start—instead of climate models—from practical needs and think how the climate scenarios and models help really in the difficult task of designing better water structures, outline better policies and formulate better operational rules in the water field.  相似文献   

Lithology and trace-metal content in till in the kuhmo granite-greenstone terrain, eastern Finland     

Matti Saarnisto  Kalle Taipale 《Journal of Geochemical Exploration》1985,24(3):317-336

Rocks of the Archaean Kuhmo greenstone belt and the fine fraction (− 63 μm) of 236 till samples were analysed for Co, Cr, Cu, Mn, Ni, Pb, Zn and Fe mainly with the AAS method. The influence of bedrock upon the lithology and geochemistry of till is clear, and can be seen immediately at the proximal contact. Expected trace-metal contents for the fine fraction of till were calculated using the average metal contents of the rock types and the proportions of these rock types in the till (2–6 cm pebbles). The expected values were then compared with the measured values in the fine fraction of till at the same locality. This approach seems effective for lithological comparison between various grain-size fractions of till.In general, the measured metal contents are clearly lower than expected. This indicates that the proportion of the greenstone material in the fine fraction of the till is smaller than in the coarse fraction. Correlations between measured and expected values of individual trace metals as well as their correlation with the different rock types are low, in most cases indicating inconsistent variation in the lithology of the coarse and fine fraction of the till. Good positive correlations between the number of pebbles of mafic metavolcanics and contents of Cu, Co, Mn and Fe in the fine fraction of till show that the influence of these rocks on the trace-element geochemistry of the tills in the study area is most significant as might be expected.  相似文献   

Neuere Veröffentlichungen     

K. Kalle 《Ocean Dynamics》1961,14(5):197-198

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Neuere Veröffentlichungen     

Fr. Model  H. Weidemann  K. Kalle 《Ocean Dynamics》1959,12(3):130-132

Ohne Zusammenfassung  相似文献   

Neuere Veröffentlichungen     

K. Kalle  F. Nusser 《Ocean Dynamics》1959,12(6):272-273

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K. Kalle  H. Stoltenberg 《Ocean Dynamics》1955,8(3):128-131

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K. Kalle  E. H. Rogalla  E. H. Rogalla 《Ocean Dynamics》1964,17(2):86-88

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Franz Zorell †     

K. Kalle 《Ocean Dynamics》1956,9(3):149-150

Ohne Zusammenfassung

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Franz Zorell

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