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Abstract  

It has been established that the coexistence of chemical species structurally different from cerium, is a direct consequence of the time taken for its preparation. Its practical applications, within the scope of purifying uranium, may constitute the most important technological aspect in the process of ionic exchange, to separate141Ce from uranium.

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Influence of thermal and thermo-mechanical treatment

Comparison of two lipids with respect to their suitability for solid lipid extrusion

Journal of Thermal Analysis and Calorimetry
Authors: Claudia Reitz and P. Kleinebudde

Abstract  

Two lipids with similar melting ranges but of different composition were analyzed using differential scanning calorimetry and X-ray diffraction. The lipids were processed via extrusion or were tempered at different temperatures; they were analyzed directly after extrusion and after storage at 40�C. Precirol ATO 5� showed high sensitivity to storage time and varied temperature exposure. Extrusion showed only marginal influences on the solid state. Melting peaks were narrower and shifted to higher temperatures in comparison to the untreated powder. Dynasan 114� was more robust, changes in the solid state could only be shown for samples treated above the melting range. Thus, Dynasan 114� is more appropriate for solid lipid extrusion of pharmaceutical products.

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Abstract  

Stability of mineral mixed fertilizers processed by effective mixing and compaction, using extrusion technology, is a subject of this study. As new products there is a need to learn the possible changes in the phase ratios and caking processes during long term storage. 7 samples with different nutrient components ratios are investigated after one year kept in a storage facility without conditioning. Applying TG-DTA, electron microscopy and X-ray diffraction methods samples are studied, recording thermal effects and mass losses, type of crystal structures and phase content in the sample. On the base of the results obtained the relationships are discussed and conclusions made about the possibility to safety storage and visible application of the new products as fertilizers in the agriculture for nut ratio of different plant. It is confirmed that the investigated samples, produced on the base of low grade phosphates are stable during long term storage and they could be successfully recommended for practical use in agriculture, using traditional or individual method of fertilization.

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Abstract  

Mechanical alloying is a versatile technique for the solid state synthesis of many materials, including alloys such as iron-copper where the elements are immiscible under equilibrium conditions. The structural and magnetic state of these alloys, and their thermal stability, have been investigated by means of thermomagnetometry, DSC, X-ray diffraction and Mssbauer spectroscopy. Comparison of the thermomagnetometry curves for the various alloys together with analysis of intermediate reaction products enabled the individual thermal processes to be identified. The Curie temperature of the alloys was measured, and it was found that on heating the metastable alloys underwent phase segregation between 300-400C.

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Abstract  

Coal-tar pitch was modified by addition of polystyrene, poly(ethylene terephthalate), unsaturated polyester and coumarone-indene resin. The optimum conditions for production of homogeneous binary pitch-polymer blends containing 10% w/w of the polymer were established. Softening points, contents of toluene and quinoline-insoluble matters and rheological properties of the blends were determined. The yield of solid fraction in semi-coking the blends was also found. The effect of polymers on the coal-tar pitch blend properties was evaluated. Some pitch-polymer blends were then carbonized to carbon sorbents used for purification of water and wastewater.

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Abstract  

Phosphate rocks were leached with hydrochloric acid; and radium was removed by co-precipitation with BaSO4. Uranium and lanthanides were extracted by di(2-ethyl hexyl) phosphoric acid and tributyl phosphate. Phosphoric acid was then separated from calcium chloride solution and other impurities by extraction using undiluted iso-amyl alcohol. Gypsum was precipitated by sulfuric acid to regenerate hydrochloric acid for recycling. Fluorine was precipitated from the initial leach solution as Na2SiF6.

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Abstract  

The use of titanium oxide as a photocatalyst in the degradation of organic complexing agents by ultraviolet radiation is being studied as a possible method for the removal of radioactive ions from solutions of these complexing agents that have been used to decontaminate nuclear facilities. Inorganic absorbers are being increasingly used for the decontamination of radioactive aqueous wastes. Information is presented on two areas of study to incorporate inorganic absorbers into a matrix material in order to provide a granular product suitable for use in a packed bed. Finally, information is reported on the combination of inorganic absorbers with magnetite in order to allow separation of the loaded absorber from the treated liquid waste by use of a magnet.

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Abstract  

The paper is devoted to the utilization of ferrofluid as a separating medium and modifying agent affecting the magnetic properties of solid and liquid materials. The separation tests in a MHS separator have been carried out under laboratory condition. The selectivity of ferrofluid's adsorption to the surface of some materials can be used for enhancing the magnetic susceptibility and influencing the efficiency of separation process. The enhancement of magnetic susceptibility of oil products up to a level sufficient for their magnetic extraction from water is possible by admixing of a definite amount of kerosene-based ferrofluid, which is non-miscible with water. The results point to the fact that the MHS method is suitable for the separation of non-magnetic materials according to their density and the modification of magnetic properties of materials by ferrofluid enhancing their magnetic separability.

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