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1.
Multi-component adsorption of Ag(I), Cd(II) and Cu(II) by natural carbonaceous materials 总被引:1,自引:0,他引:1
Adsorption of silver, cadmium and copper from aqueous solutions by natural carbonaceous materials was investigated. The studied series of natural materials (spruce wood, pine bark, cork, peat, fusinite, lignite, oxidised lignite, bituminous coal and anthracite) was extended to include industrial carbon-rich materials: coke, activated carbon F-400 and Multisorb 100. Adsorption was tested on a single-component system and on the binary and ternary mixtures. All the materials used differ in their ability to adsorb selected metals. The adsorption of metals is significantly affected by the presence of other ions in solution. Total metal uptake was considerably higher in a mixture than single-ion adsorption. Chemical reactions, such as precipitation and reduction of metallic silver, play a role in metal uptake by bituminous coal, coke and activated carbon. 相似文献
2.
Ettler V Johan Z Baronnet A Jankovsky F Gilles C Mihaljevic M Sebek O Strnad L Bezdicka P 《Environmental science & technology》2005,39(23):9309-9316
The mineralogy and solubility of air-pollution-control (APC) residues from a secondary lead (Pb) smelter have been studied on samples from the Príbram smelter, Czech Republic, recycling car batteries, with the emphasis on their potential environmental effect. The presence of dominant anglesite (PbSO4) and laurionite (Pb(OH)Cl) was observed in a sintered residue from after-burning chambers (800-1000 degrees C). In contrast, low-temperature Pb-bearing phases, such as KCl x 2PbCl2 and caracolite (Na3Pb2(SO4)3Cl), were detected in the major APC residue from bag-type fabric filters. Metallic elements, zinc (Zn), cadmium (Cd), and tin (Sn) were found homogeneously distributed within this residue. The formation of anglesite, cotunnite (PbCl2), (Zn,Cd)2SnO4, and (Sb,As)2O3 was observed during the sintering of this APC residue at 500 degrees C in a rotary furnace. The 168 h leaching test on filter residue, representing the fraction that may escape the flue gas treatment system, indicated rapid release of Pb and other contaminants. Caracolite and KCl x 2PbCl2 are significantly dissolved, and anglesite and cotunnite form the alteration products, as was confirmed by mineralogical analysis and PHREEQC-2 modeling. The observed Pb-bearing chlorides have significantly higher solubility than anglesite and, following emission from the smelter stack, can readily dissolve, transferring Pb into the environmental milieu (soils, water, inhabited areas). 相似文献
3.
In this work The authors solve the standard multivariable ℋ 2-optimal control problem using polynomial matrix techniques 相似文献
4.
Linear matrix equations in the ring of polynomials in n indeterminates (n -D ) are studied. General- and minimum-degree solutions are discussed. Simple and constructive, necessary and sufficient solvability conditions are derived. An algorithm to solve the equations with general n -D polynomial matrices is presented. It is based on elementary reductions in a greater ring of polynomials in one indeterminate, having as coefficients polynomial fractions in the other n -1 indeterminates, which makes the use of Euclidean division possible 相似文献
5.
J. Verloop L. J. M. Boumans H. van Keulen J. Oenema G. J. Hilhorst H. F. M. Aarts L. B. J. Sebek 《Nutrient Cycling in Agroecosystems》2006,74(1):59-74
Dairy farming is one of the main contributors to nitrate leaching to groundwater, particularly on soils that are susceptible
to leaching, such as light well-drained sandy soils. In the Netherlands, as in many other European countries, these soils
are predominantly used for dairy farming. A prototype dairy farming system that has been implemented in practice in 1989 has
continuously been adapted since then to meet environmental standards (i.e. the EU-standard of 50 mg NO3− l−1) without reducing milk production intensity (11900 kg ha−1). After an initial decline in nitrate concentration from 193 mg l−1 to 63 upon implementation, it subsequently ‘stabilized’ at a level higher than the environmental standard: 55 mg l−1. The goal of this paper is to examine causes of excessive nitrate leaching. This was done by relating measured nitrate concentrations
with management characteristics such as N balances, cropping patterns and grazing intensities. Special attention was paid
to aspects that were supposed to be conducive for leaching: crop rotation of grass and maize and grazing. No evidence was
found for enhanced nitrate leaching due to the rotation of grass with maize compared to permanent cultivation. This could
be ascribed to the reduction in fertilization levels in first and second year maize with 90 and 45 kg N ha−1, respectively to account for the expected N release from the ploughed-in grass sod. Triticale was found to lead to higher
leaching than grass or maize which is attributed to its poor growth in the period that it should function as catch crop in
maize. Grazing contributed to a nitrate increase of about 30 mg NO3− l−1 on grassland. As grazing management and intensity is already strictly optimized in order to restrict nitrate leaching, this
result underpins the need to develop sustainable grazing methods on soil that is susceptible to nitrate leaching. 相似文献
6.
Rank-one LMI Approach to Stability of 2-D Polynomial Matrices 总被引:2,自引:2,他引:0
Henrion Didier Sebek Michael Bachelier Olivier 《Multidimensional Systems and Signal Processing》2001,12(1):33-48
Multidimensional Systems and Signal Processing - 相似文献
7.
H. Stärker R. Sebek Gerald Schlatte 《e & i Elektrotechnik und Informationstechnik》1997,114(2):111-113
8.
9.
Henrion D. Peaucelle D. Arzelier D. Sebek M. 《Automatic Control, IEEE Transactions on》2003,48(12):2255-2259
The stability domain in the space of coefficients of a polynomial is a nonconvex set in general. In this note, we propose a new convex ellipsoidal inner approximation of this set derived via optimization over linear matrix inequalities. As a by-product, we obtain new simple sufficient conditions for stability that may prove useful in robust control design. 相似文献
10.
Numerical procedures are proposed for triangularizing polynomial matrices over the field of polynomial fractions and over the ring of polynomials. They are based on two standard polynomial techniques: Sylvester matrices and interpolation. In contrast to other triangularization methods, the algorithms described in this paper only rely on well-worked numerically reliable tools. They can also be used for greatest common divisor extraction, polynomial rank evaluation, or polynomial null-space computation 相似文献