6 research outputs found
ГИГИЕНИЧЕСКАЯ ОЦЕНКА СОСТОЯНИЯ ПОЧВЕННОГО ПОКРОВА И РАСТИТЕЛЬНОЙ ПРОДУКЦИИ НА ТЕРРИТОРИЯХ, ПРИЛЕГАЮЩИХ К НЕФТЕПЕРЕРАБАТЫВАЮЩИМ И НЕФТЕХИМИЧЕСКИМ КОМПЛЕКСАМ РЕСПУБЛИКИ БАШКОРТОСТАН
Soil contamination occurs as a result of adsorption of atmospheric emissions, storage and disposal of waste in the extraction, processing of oil and petrochemical industries. The evidence of participation of the petrochemical complex in soil contamination of adjacent territories with oil products and other chemical compounds was obtained. Hygienic assessment of the state of the soil cover is based on the study of polymetallic pollution, some elements of which have reasonable hygienic regulations. The detected concentrations of polymetals and petroleum products at a distance of 1 - 3 km and 3 - 6 km from the petrochemical complex can be attributed to soil contamination, respectively, to the category of "extremely dangerous" and "dangerous". The characteristic of the hygienic condition of the soil cover and agricultural crops (vegetables) grown in these territories is given. The main harmful components of the petrochemical complex are capable of translocation from contaminated soil to crops and vegetables within a radius of 20-25 km. The most intensive pollution of vegetables is observed at a distance of 6-10 km from the sources of pollution.La contaminación de la cubierta del suelo se produce como consecuencia de la adsorción de las emisiones atmosféricas, el almacenamiento y el entierro de los residuos durante las industrias de extracción, refinación y petroquímica. Se ha obtenido evidencia de la participación del complejo petroquímico en la contaminación del suelo de los territorios adyacentes con productos derivados del petróleo y otros compuestos químicos. La evaluación higiénica de la condición del suelo se basa en el estudio de la contaminación polimetálica, algunos de los cuales tienen regulaciones higiénicas razonables. Las concentraciones encontradas de polimetales y productos petrolíferos a una distancia de 1 a 3 km y de 3 a 6 km del complejo petroquímico permiten clasificar la contaminación del suelo como “extremadamente peligrosa” y “peligrosa”, respectivamente. Se presenta la característica del estado higiénico de la cobertura del suelo y los cultivos (hortalizas) cultivados en estos territorios. Los principales componentes dañinos del complejo petroquímico son capaces de translocarse de suelos contaminados a cultivos y vegetales en un radio de hasta 20-25 km. La contaminación más intensa de los vegetales se observa a una distancia de hasta 6-10 km de las fuentes de contaminación.Загрязнение почвенного покрова происходит в результате адсорбции атмосферных выбросов, складирования и захоронения отходов при добыче, переработке нефти и нефтехимических производств. Получены доказательства участия нефтехимического комплекса в загрязнении почвы прилегающих территорий нефтепродуктами и др. химическими соединениями. Гигиеническая оценка состояния почвенного покрова основана на изучении полиметаллического загрязнения, отдельные элементы которого имеют обоснованные гигиенические регламенты. Обнаруженные концентрации полиметаллов и нефтепродуктов на расстоянии 1 - 3 км и 3 - 6 км от нефтехимического комплекса позволяют отнести загрязнённость почвы, соответственно к категории «чрезвычайно опасных» и «опасных». Дана характеристика гигиенического состояния почвенного покрова и сельскохозяйственных культур (овощей), выращенных на этих территориях. Основные вредные компоненты нефтехимического комплекса способны к транслокации из загрязненной почвы в сельскохозяйственные культуры и овощи в радиусе до 20-25 км. Наиболее интенсивное загрязнение овощей отмечается на удалении до 6-10 км от источников загрязнения
Study of the electrophysical properties of nanostructured porous germanium as a promising material for electrodes of electrochemical capacitors
Electrochemical capacitors (ECC) are a fast charging devices, with high power density, capacity and increased life time. Nanostructured semiconductors are now considered as the promising materials for electrodes of such devices due to its conductive properties and effective surface. One of such materials is the porous germanium which can be used as an electrode in electrochemical capacitors. In this article the novel approach based on the method of ion implantation was developed to grow these structures. This method allows to obtain a structures up to 1 μm thick. The object of this work was the investigation of the electrophysical characteristics of samples of nanostructured porous germanium (Ge) depending on the implantation dose and surface morphology. The scientific novelty of this research lies in the search the structures with the highest effective surface area and electronic conductivity, capable of multiplying the energy capacity and specific power of ECC. Methods: The samples of amorphous Ge were grown on dielectric single-crystal substrates of Al2O3. The thickness of samples was 600 and 1000 nm. The magnetron sputtering and ion implantation methods were used to growth these structures. The irradiation with Ge+ ions produced with an energy of 40 keV and the range of implantation doses varied from 2·1016 to 12•1016 ion / cm2. The study of electrical properties was carried out on the Hall installation HL55PC at the NPP KVANT in Moscow. The following parameters were measured: the sheet concentration of carriers in the near-surface layer, electrical resistance, mobility of the charge carriers, Hall coefficient. As a result, the dependences of carriers concentration and their mobility as the function of the implantation dose and thickness of the samples of nanostructured porous germanium were determined, and the results were analyzed. Results: It was found that ion implantation of single-crystal germanium leads to an increase in the carrier concentration in the near-surface layer. To sum up, the most suitable material as an electrode for ECC is the porous germanium with the maximum dose of ion implantation and the largest thickness. The maximum sheet carrier concentration that was obtained in the study for Ge is 1017 cm-2
ESR Investigations of the Submicron LiFe<sub>1−x</sub>Mn<sub>x</sub>PO<sub>4</sub> Systems
Magnetic properties of the submicron carbon-coated LiFe1−xMnxPO4 (x = 0, 0.01, 0.1) systems were investigated using the electron spin resonance (ESR) method. The observed ESR signal consisted of two broad resonance lines with a Lorentzian line shape for all samples. The temperature dependence character of the integral intensity of these lines changed significantly with increasing manganese concentration, indicating a change in the nature of the magnetic interactions between the manganese and iron ions. We suggest that the noticeable capacity loss observed in the LiFe1−xMnxPO4 systems with increasing Mn content can be explained by the random distribution of Mn ions and changes to the type of magnetic ordering in these systems, despite the attractiveness of the electrochemical Mn2+/Mn3+ pair compared with Fe+2/Fe+3
Li<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>/Li<sub>3</sub>PO<sub>4</sub> Cathode Materials for Li-Ion Batteries: Synthesis and Characterization
Li3V2(PO4)3/Li3PO4 (LVPO/LPO) composites as cathodes for Li-ion batteries were synthesized by the hydrothermal method and subsequently annealed in an Ar atmosphere. The effect of Li3PO4 content on the crystal structure, morphology and the related magnetic and electrochemical properties of Li3V2(PO4)3/Li3PO4 composites, containing 7.5 wt% and 14 wt% of Li3PO4 (LVPO/LPO-7.5 and LVPO/LPO-14) was investigated. The microstructure and morphology of the obtained composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM); magnetic and electrochemical properties investigations were performed using the electron spin resonance and galvanostatic methods, respectively. It was shown that Li3V2(PO4)3/Li3PO4 composites exhibit a high discharge capacity, good cycle performance (105 and 120 mAh g−1 for the 200th cycle at 1C for LVPO/LPO-7.5 and LVPO/LPO-14, respectively), and insignificant changes in the surface morphology after 200 lithiation/delithiation cycles. Our results demonstrate that the increase in Li3PO4 content led to a decrease in the Li stoichiometry and magnetic inhomogeneity in Li3V2(PO4)3 phase; thus, the improvement in the electrochemical performance of LVPO/LPO composites due to incorporation of Li3PO4 can be attributed to their chemical and magnetic inhomogeneity
Structural and electrochemical properties of lithiated conical carbon nanotubes as anode materials for lithium ion accumulating systems
Magnetic Properties of Li3V2(PO4)3/Li3PO4 Composite
Here, we present the investigation of the magnetic properties of Li3V2(PO4)3/Li3PO4 composites, which can be potentially used as a cathode material in lithium-ion batteries. Li3V2(PO4)3/Li3PO4 was synthesized by the thermal hydrolysis method and has a granular mesoporous structure. Magnetic properties of the composite were investigated using magnetometry and electron spin resonance methods. Based on magnetization measurements, the simultaneous existence of the paramagnetic phase with antiferromagnetic interactions between spins of V3+ ions and magnetically correlated regions was suggested. Most probably, magnetically correlated regions were formed due to anti-site defects and the presence of V4+ ions that was directly confirmed by electron spin resonance measurements