Thin-layer chromatography on polyacrylonitrile. V. Consideration of separation mechanisms of some aliphatic and aromatic amines

The chromatographic behaviour of ten aliphatic and aromatic amines on thin layers of polyacrylonitrile sorbent was investigated using seven aqueous solvent systems. It was established that an increase in the hydrophobic part of the amines results in their increased retention on this sorbent. A positive linear depencence between the number of carbon atoms in the n-alkyl groups of primary aliphatic amines and the corresponding RM values was also established. The separation of the investigated amines was assumed to be based on non-specific hydrophobic interactions between their non-polar parts and the hydrocarbon chains of the sorbent. © 1992

Lawton, Michael T: Seven aneurysms: Tenets and techniques for clipping: Thieme 2011, ISBN 978-1-60406-054-6

In this paper, the removal of methylene blue (MB) from aqueous solution by biosorption onto apricot shellshas been investigated through batch experiments. Apricot shells were chosen as a locally available and abundant waste from fruit juice industry. Methylene blue is common pollutant of waste waters from textile industry. The influence of initial MB concentration on biosorption process has been studied. The experimental data have been analysed using Langmuir and Freundlichisotherm models. The Langmuir model better fits to experimental data, which explain monolayer adsorption. Maximum biosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shells with biosorption capacities of similar adsorbents previously investigated indicates that apricot shells could be a promising biosorbent for removal of MB from aqueous solution

Pleomorphic Vulvar Leiomyoma with Local Invasive Behavior

A case of pleomorphic leiomyoma in Bartholin gland\u27s area in a 26-year-old woman is reported. After diagnostic treatment, primary excision was done. A large, solid tumor 10 7.5 cm was extirpated. The tumor showed locally invasive behavior, which suggested a malignant tumor of Bartholin gland, because of it\u27s localization and outlook. Pathohistological examination and immunohistochemical reactions proved that it was a mesenchymal tumor of smooth muscle origin with marked polymorphism, without mitosis, with a myxoid stroma and with biological aggressivity, and the possibility of local recurrence. Thus, a second more radical surgical procedure, was performed. In the excised tissue, no residual tumor was found and all lymphnodes were negative

Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

Application of magnetic wedges for stator slots of hydrogenerators

SUMMARY The utilization of slot wedges made of magnetic material in a synchronous and induction motor or generator makes possibility to increase the efficiency of the machine. In this paper, the experiences acquired in design, installation, testing and exploitation of the magnetic slot wedges on two relatively large hydrogenerators of rated output 34 MVA, 10.5 kV, 50 Hz, 187.5 min -1 , cos = 0,8, vertical form, are presented. The magnetic slot wedges with high mechanical strength and low average permeability of r = 2,8 are embedded into open stator slots of the two hydrogenerators. The fixation of magnetic wedges in the stator winding slots is described in detail. The data referring to magnetic and mechanical properties of the installed magnetic wedges are presented. With magnetic slot wedges the magnetizing current in excitation winding required to generate the airgap flux is lower than with non-magnetic slot wedges. The results obtained in the design stage and the comparison of on-site testing results of the generator with non-magnetic wedges and the same generator with magnetic wedges show an increase in efficiency. By installing the described magnetic wedges the surface losses in the generator rotor pole shoe iron were reduced by app. 20%, whereas the losses in the excitation winding were reduced by app. 8% due to the reduced air gap magnetizing current. In addition, the results obtained by analytical calculation and by measurement of the magnetic wedge influence on generator's reactances are provided. Due to reduction of excitation current in no-load operation, synchronous reactances in direct and quadrature axis increase by app. 5% in the case of magnetic wedges. If an increase of reactances due to leakage reactance is taken into consideration, the total increase of synchronous reactances is app. 8%

REMEDIATION OF THE SERBIAN SOILS CONTAMINATED BY RADIONUCLIDES IN THE FUNCTION OF THE SUSTAINABLE DEVELOPMENT

Phosphate-induced metal stabilization (PIMS) using apatite stabilizes uranium in situ, by chemically binding it into the new low-solubility (Ksp=10-49) phase. Uranium-phosphate-autunite is stable across a wide range of geological conditions for millions of years. A large area of contaminated soil is suitable for insitu remediation that involves minimizing the mobility of the uranium. Laboratory study was conducted to quantify different forms of apatite sequestration of uranium contaminant. The experiment was done with natural phosphate from Lisina deposit (14.43 % P2O5), with non-treated samples, phosphate concentrate samples with 34.95 % P2O5 and mechanochemically activated of natural apatite. Different concentration of P2O5 in apatite, pH, reaction time, solid/liquid ratio was investigated. The concentrate at pH 5.5 for 7 days sorbed around 93,64 % and nature apatite, with 14,43 % P2O5, for 30 days sorbed 94.54 % of the uranium from the water solution, concentration 100 μg U/ml. The results show that mineral apatite “Lisina” is very effective for the treatment of contaminated soils - in situ immobilization of U. Mechanochemical activation of natural apatite in vibration mill immobilized 85.37 % of uranium in the 7-day period of acting. This research on natural apatite from the deposit “Lisina” for immobilization of uranium was the first one of this type in our country

Analytical possibilities for the relative estimation of the antioxidative capacity of honey varieties harvested in different regions of Serbia

Two different approaches, spectroscopic and electrochemical, were applied for rough determination of antioxidative potential of honey samples. Honey samples of diverse botanical origin were collected in different geographical regions in Serbia. Total phenolic content (TPC) was determined by Folin-Ciocalteu method. Cyclic voltammograms on a glassy carbon electrode in KCl supporting electrolyte were used to check electrode sensitivity to the presence of honey. In order to calculate Trolox Equivalent Antioxidant Capacity (TEAC) of studied honey, cyclic voltammograms were recorded for Trolox standard. The results were expressed as μmol of Trolox Equivalents per kg of sample (μmol TE kg-1). Good correlations were observed between cyclic voltammetry data and total phenolic content (TPC) determined by Folin-Ciocalteu method and radical scavenging activity (RSA) determined using DPPH•(1,1-diphenyl-2-picrylhydrazyl radical) test. Cyclic voltammetry appears to be a highly attractive alternative method for rapid estimation of antioxidative potential of honeys. It was found that polyfloral honey samples had the highest, whereas acacia honey showed the lowest values of TPC. [Projekat Ministarstva nauke Republike Srbije, br. 172017 i br. 172030