[en] The unit consists of a fixed cylindrical hood containing a pipe with the gamma source. The gamma source is isolated by shielding lead cylinders. A bed is formed in the upper part of the hood. Along the hood there is an ambrasure. The diameter of the inside pipe is smaller at its lower end holding the gamma source. Intermediate shielding elements with a connecting axial rope are mounted above the gamma source. The rope is connected to the gamma source. The upper end of the pipe is securely closed by a shielding element. It is claimed that loading and reloading of the unit is accomplished in ''dry'' way with an only shipping container and the rope being inseparable connected to the radioacive unit makes the loading and reloading easy and safe

[en] The use of renewable energy sources are increases, as by UCTE data for 2007, electricity production in the European Union from wind farms is nearly 30% more than in 2006. In recent years Bulgaria has built many wind power stations, as by 2008 the installed capacity increased by 35%. The purpose of this work is to propose a methodology for obtaining of the indicators of daily average load profiles of wind power station and on this basis to obtain and analyze data about the usability of a particular wind power station. (authors)

[en] The unit consists of an irradiation chamber incorporated into a biological shield. The chamber has a step protected door installed on a carriage moving on rails. The door is provided with a rotating platform with a cage. The irradiation chamber has vertical cylinders in its corners. The cylinders are two by two symetrical and are connected by a movable cylinder containing in its lower end a linear irradiator. Each movable cylinder is provided with a hydraulic and a blocking rim connected to the door

[en] Small amounts of perrhenate in fairly concentrated sulphuric acid media and in the presence of tin(II) chloride are found to catalyse the acid hydrolysis of α-furildioxime, with production of a new absorption peak at 320 nm, due to the di-α-furildiketone produced. The catalytically active species is a sulphate complex of rhenium(IV). The catalytic action of rhenium is promoted by citric acid. Rhenium can be determined in the range 0.0005 to 0.5 μg/ml. Interferences are eliminated by a preliminary extraction. The method has been applied to the determination of rhenium in copper concentrates of low rhenium content, copper ores and rocks. On the basis of the inhibitory effect of molybdenum the reaction can be used for determination of this element as well. (author)

[en] We aimed to assess the role of single photon emission computed tomography-computed tomography (SPECT/ CT) for characterizing nonconclusive lesions, observed by planar WB bone scintigraphy and to evaluate the impact of SPECT/CT on oncologic patient management. Data from 269 patients with oncologic diseases who had undergone WB BS for staging and 29 of them with nonconclusive lesions, passed SPECT/CT of a selected volume, were retrospectively analyzed. Planar scintigraphy and SPECT/CT images were independently evaluated in separate sessions to minimize recall bias. Among the 269 WB BS, in 37 patients multiple bone metastases were confirmed. In 161 patients degenerative lesions in the skeleton were defined, 42 patients were with normal bone scan and in 29 patients the results were nonconclusive for bone metastases. The fused scan after SPECT/CT imaging confirmed bone metastases in 11 (38%) patients with 27 new metastatic lesions and benign degenerative lesions in 18 patients. SPECT/CT is better than planar WB BS for characterizing equivocal lesions that are observed by bone scintigraphy, thus SPECT/CT can have a significant impact on patient management in staging the oncologic disease. (authors)

[en] The sensitivity of the photometric determination of rhenium with rhodanide, α-furyldioxime or dimethyl dioxime can be increased by one order of size by application of appropriate rules of experimental procedure. The procedure suggested was used to determine the rhenium content in copper concentrates. (author)

No abstract available

[en] The possibility for obtaining energy based on oxidation of sulfide and sulfite ions while simultaneously solving an environmental problem is regarded. The catalysts used for the processes are shown. Different constructions of the fuel cells are studied. An analysis of the results so far is made, as well as possible future development. Key words: fuel cells, sulfides, sulfites

[en] Paddlings of structured activated carbon are used as electrodes in a fuel cell for sulfide oxidation and nitrate reduction. The influence on the electrochemical parameters of multiple uses at the same conditions are investigated as well as the rates of depletion of the sulfides and nitrates. Regeneration of the used paddlings by thermal desorption is conducted and the paddlings are retested. The obtained electrical power rapidly decreases after the first use of the paddlings and after that the power level remains relatively constant. This is due to the wash up of some active centers over its surface. The thermal desorption increases the electrical properties of the cell. The depletion of sulfides and nitrates is within the ecological limits. A conclusion can be made that the structured activated carbon paddlings can be successfully used as electrodes for continuous operation of a sulfide-nitrite fuel cell.

[en] This study is an attempt for simultaneous removal of sulphates and nitrates from municipal, agricultural and industrial wastewaters by oxidation of the sulphides to sulphates and reduction of the nitrates to nitrogen in electrochemical way. The processes are carried out in newly designed fuel cells and as a result energy is released which can be used. The aim of the work is to improve the energy efficiency of the fuel cell by minimizing internal losses by optimizing the material, design and position of the electrodes.