| 1. |
- Manouchehri, Hamid-Reza, et al.
(author)
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Review of electrical separation methods : Part 1: Fundamental aspects
- 2000
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In: Minerals & metallurgical processing. - 0747-9182. ; 17:1, s. 23-36
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Journal article (peer-reviewed)abstract
- The fundamentals of electrical separation, the electrical properties of minerals, the principal methods used for charging minerals and their mechanisms, the effective factors controlling the acquisition of charges by minerals, the general configuration of commercial electric separators and the forces operating during electrical separation of minerals are reviewed and presented.
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| 2. |
- Manouchehri, Hamid-Reza, et al.
(author)
-
Review of electrical separation methods : Part 2: Practical considerations
- 2000
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In: Minerals & metallurgical processing. - 0747-9182. ; 17:3, s. 139-166
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Journal article (peer-reviewed)abstract
- This paper summarizes the practical considerations of the various electrical separation methods used in mineral processing. The effective factors related to mineral characteristics and equipment attributes are described and analyzed with reference to conventional industrial applications of the electrical methods. Some new aspects of electrical methods application and their potential for mineral beneficiation, apart from the mineral systems that have been successfully beneficiated, are also presented. In addition, wet dielectric separation, which now appears to be promising, is briefly cited.
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| 3. |
- Hedenqvist, Mikael S., et al.
(author)
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Transport properties of hyperbranched and dendrimer-like star polymers
- 2000
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In: Polymer. - 0032-3861 .- 1873-2291. ; 41:5, s. 1827-1840
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Journal article (peer-reviewed)abstract
- Moisture transport properties were assessed by sorption and desorption measurements on hydroxyl-functional hyperbranched polyesters based on 2,2-bis(methylol) propionic acid (bis-MPA) as AB(2)-monomer with ethoxylated pentaerythritol. A series of these polymers with different molar masses were studied. For the first time, it is reported that sigmoidal sorption curves were successfully modelled using a time-dependent surface boundary concentration, where the relaxation time was obtained from the mechanical stress relaxation data. The zero concentration diffusivities were very small and comparable with the values of fully amorphous poly(vinyl alcohol). Both the diffusivity data and the stress relaxation data indicated that these materials were plasticized by moisture. Ethylene glycol transport properties were measured on a hexadecanoate(C16)-terminated bis-MPA hyperbranched polymer. The replacement of the hydroxyl groups with C16 paraffin tails resulted in an increase in solute diffusivity despite the fact that these polymers became semicrystalline. The shape of the desorption curves indicated that continuous micropores were present and facilitated mass transport. The moisture transport properties were also measured on a series of semicrystalline dendrimer-like star poly(epsilon-caprolactone(s)). The low measured densities of these highly crystalline dendrimers confirmed that the porosity, as indicated by the shape of the desorption curves, had to be discontinuous. The porosity in the (C16)-terminated and the poly(epsilon-caprolactone(s)) was impossible to eliminate by applying a high external pressure during crystallization. A collective view of all the results obtained confirm that the transport properties are primarily controlled by the hydroxyl group concentration.
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| 4. |
- Kristjansson, I, et al.
(author)
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Assessment of aluminium in human deciduous teeth
- 2000
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In: European Journal of Epidemiology. - 0393-2990 .- 1573-7284. ; 16:3, s. 231-233
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Journal article (peer-reviewed)abstract
- The possible role of environmental aluminium exposure in the pathogenesis of various diseases has highlighted the need for methods by which the long-term exposure to aluminium can be assessed. Therefore, we have further developed a method to determine aluminium in human deciduous teeth and applied this method for studying populations in Sweden, Crete and Iceland.
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| 5. |
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| 6. |
- Manouchehri, Hamid-Reza, et al.
(author)
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Tribo-electric charge and separation characteristics of chemically treated feldspar, quartz and wollastonite minerals
- 2002
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In: Magnetic and Electrical Separation. - : Hindawi Limited. - 1055-6915 .- 1029-0303 .- 1477-2876. ; 11:1-2, s. 9-32
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Journal article (peer-reviewed)abstract
- The triboelectric charge attributes of the pure feldspar, quartz and wollastonite mineral samples, after contact with plate and cyclone type tribochargers made up of different materials were investigated. The main electrical properties of the minerals, i.e., electrical conductivity and dielectric constant, were measured and their energetic work functions were estimated. In addition, the behaviour of mineral samples in the electric field of a free-fall separator before and after chemical treatment with different organic reagents was deduced.The results reveal that the cyclone tribochargers are more effective in imparting charges on mineral grains. The reproducible charges with higher magnitudes are created when cyclones are used for imparting charges on mineral grains. Furthermore, in spite of having relatively similar energetic structures for the three minerals, the Teflon tribocharger demonstrates the feasibility of quartz separation from wollastonite and feldspar. The salicylic acid conditioning promotes feldspar-wollastonite separation.
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| 7. |
- Manouchehri, Hamid-Reza, et al.
(author)
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Triboelectric charge characteristics and donor-acceptor, acid-base properties of minerals - Are they related?
- 2001
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In: Particulate Science and Technology. - 0272-6351 .- 1548-0046. ; 19:1, s. 23-43
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Journal article (peer-reviewed)abstract
- The tribo/contact electrification theory of materials is envisaged from the chemical Lewis acid-base concept and an attempt has been made to find a correlation between these two phenomena. The donor-acceptor/acid-base properties of apatite, calcite, feldspar, quartz and wollastonite mineral samples have been determined by electrokinetic studies in water and in different organic solvents having different donicity values. From the results, the donicity values for mineral samples were defined and the position of Fermi level in the forbidden gap energy was estimated. The charge acquired by a single mineral particle of varying sizes was determined after contacting with plate and cyclone type tribochargers made up of different materials. The work functions of the mineral samples were estimated.The results showed a good correlation between the physical tribo-electrification process and the chemical acceptor-donor property of the minerals. The results also demonstrate the feasibility of arranging the minerals into triboelectric series and thereby to predict their triboelectric charge characteristics and their separation behavior in an electric field with reference to a particular tribocharger medium.
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| 8. |
- Staudt, A, et al.
(author)
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beta(1)-Adrenoceptor antibodies induce positive inotropic response in isolated cardiomyocytes.
- 2001
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In: European journal of pharmacology. - 0014-2999. ; 423:2-3, s. 115-9
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Journal article (peer-reviewed)abstract
- beta(1)-Adrenoceptor autoantibodies are present in approximately 30% of patients suffering from dilated cardiomyopathy. The inotropic effects mediated by these antibodies remain to be studied. Monoclonal antibodies were raised against a peptide corresponding to the second extracellular loop of the human beta(1)-adrenoceptor in balb/C mouse (n=6), and were characterized by enzyme immunoassay after purification by protein A. Purified immunoglobulin G from non-immunized animals (controls) did not influence Ca(2+) transient and cell shortening of rat cardiomyocytes measured by confocal-laser-scanning-microscopy. beta(1)-adrenoceptor antibodies caused a dose-related increase in Ca(2+) transient (dilution 1:2: +35.3+/-5.1%), and in cell shortening (dilution 1:2: +40.5+/-6.3%) (P<0.01 vs. controls). The effect of the beta(1)-adrenoceptor antibodies was blocked by the antigenic peptide and by the antagonist metoprolol. In addition, beta(1)-adrenoceptor antibodies induced a dose-dependent increase of the cyclic adenosine monophosphate. The inotropic response induced by isoproterenol was attenuated by the beta(1)-adrenoceptor antibody. beta(1)-adrenoceptor antibodies as partial agonists induce a specific positive inotropic effect via the protein-kinase-A-cascade.
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