МЕХАНИЗМ АНОДНОГО РАСТВОРЕНИЯ КОРРОЗИОННОСТОЙКИХ И КОНСТРУКЦИОННЫХ УГЛЕРОДИСТЫХ СТАЛЕЙ В УСЛОВИЯХ ЭЛЕКТРОИМПУЛЬСНОГО ПОЛИРОВАНИЯ

In this article were suggested the schemes of anode processes, taking into account the nature of metals, anion structure, pH solution of electrolyte and anode potential by electropulse polishing of corrosion- resisting and structural carbon steels.It is shown and experimentally confirmed, that under conditions of electropulse polishing of anode dissolving of metals, which are contained into corrosion-resisting and structural carbon steels, carried out according to mechanism of complex formation through a set of series and series-parallel of intermediate stages. In the 1st stage on the surface of metals adsorption complexes with participation of chemisorption molecules of water are formed. In the next stages anions of electrolyte’s solution and molecules of water take part. In final stage of dissolving on the surface of anode soluble compounds are formed, which by transition into solution into simple ions are dissociated. It is determined that by electrical-impulse polishing in dissolving of components of corrosion-resisting carbon steels the important role play chemical processes, and anode dissolving of metals take place in the field of mixed electrochemical and diffusion kinetics . Diffusion limitations appear as a result of difficult ion mass transfer through surface salt, oxide and hydro-oxide and absorption-phase coatings.Предложены схемы анодных процессов, учитывающие природу металлов, анионный состав, pH раствора электролита и анодный потенциал при электроимпульсном полировании коррозионностойких и конструкционных углеродистых сталей.Показано и экспериментально подтверждено, что в условиях электроимпульсного полирования анодное растворение металлов, входящих в состав коррозионностойких и конструкционных углеродистых сталей, происходит по механизму комплексообразования через ряд последовательных или последовательно-параллельных промежуточных стадий. На первой стадии на поверхности металлов образуются адсорбционные комплексы с участием хемосорбированных молекул воды. В последующих стадиях принимают участие анионы раствора электролита и (или) молекулы воды. На заключительной стадии растворения на поверхности анода образуются растворимые в воде соединения, которые при переходе в раствор диссоциируют на простые ионы.Установлено, что при электроимпульсном полировании в растворении компонентов коррозионностойких и конструкционных углеродистых сталей значительную роль играют химические процессы, а анодное растворение металлов происходит в области смешанной электрохимической и диффузионной кинетики. Диффузионные ограничения возникают в результате затрудненного ионного массопереноса через поверхностные солевые, оксидные и гидроксидные адсорбционно-фазовые пленки

ИССЛЕДОВАНИЕ МОРФОЛОГИИ И ХИМИЧЕСКОГО СОСТАВА ЭЛЕКТРОИМПУЛЬСНО ПОЛИРОВАННОЙ ПОВЕРХНОСТИ УГЛЕРОДИСТЫХ И КОРРОЗИОННОСТОЙКИХ СТАЛЕЙ

The paper presents results of the investigations pertaining to morphology and chemical composition of thin surface layer of structural carbon and corrosion-resistant steel after the process of electro-impulse polishing. It has been established that removal of metal being polished occurs due to anode processes on the treated surface that leads to formation of surface films that can have different nature and thicknesses.  The paper reveals that under conditions of electro-impulse polishing anodic dissolution of steel takes place with direct participation of anions of electrolyte solution.Приведены результаты исследования морфологии и химического состава тонкого поверхностного слоя конструкционных углеродистых и коррозионностойких сталей после электроимпульсного полирования. Установлено, что съем металла при полировании происходит в результате протекания на обрабатываемой поверхности анодных процессов, приводящих к формированию поверхностных пленок, которые могут иметь различную природу и толщину. В условиях электроимпульсного полирования анодное растворение сталей происходит с непосредственным участием анионов раствора электролита

Network analysis of human glaucomatous optic nerve head astrocytes

<p>Abstract</p> <p>Background</p> <p>Astrocyte activation is a characteristic response to injury in the central nervous system, and can be either neurotoxic or neuroprotective, while the regulation of both roles remains elusive.</p> <p>Methods</p> <p>To decipher the regulatory elements controlling astrocyte-mediated neurotoxicity in glaucoma, we conducted a systems-level functional analysis of gene expression, proteomic and genetic data associated with reactive optic nerve head astrocytes (ONHAs).</p> <p>Results</p> <p>Our reconstruction of the molecular interactions affected by glaucoma revealed multi-domain biological networks controlling activation of ONHAs at the level of intercellular stimuli, intracellular signaling and core effectors. The analysis revealed that synergistic action of the transcription factors AP-1, vitamin D receptor and Nuclear Factor-kappaB in cross-activation of multiple pathways, including inflammatory cytokines, complement, clusterin, ephrins, and multiple metabolic pathways. We found that the products of over two thirds of genes linked to glaucoma by genetic analysis can be functionally interconnected into one epistatic network via experimentally-validated interactions. Finally, we built and analyzed an integrative disease pathology network from a combined set of genes revealed in genetic studies, genes differentially expressed in glaucoma and closely connected genes/proteins in the interactome.</p> <p>Conclusion</p> <p>Our results suggest several key biological network modules that are involved in regulating neurotoxicity of reactive astrocytes in glaucoma, and comprise potential targets for cell-based therapy.</p

Iceberg melting substantially modifies oceanic heat flux towards a major Greenlandic tidewater glacier

Fjord dynamics influence oceanic heat flux to the Greenland ice sheet. Submarine iceberg melting releases large volumes of freshwater within Greenland’s fjords, yet its impact on fjord dynamics remains unclear. We modify an ocean model to simulate submarine iceberg melting in Sermilik Fjord, east Greenland. Here we find that submarine iceberg melting cools and freshens the fjord by up to ~5 °C and 0.7 psu in the upper 100-200 m. The release of freshwater from icebergs drives an overturning circulation, resulting in a ~10% increase in net up-fjord heat flux. In addition, we find that submarine iceberg melting accounts for over 95% of heat used for ice melt in Sermilik Fjord. Our results highlight the substantial impact that icebergs have on the dynamics of a major Greenlandic fjord, demonstrating the importance of including related processes in studies that seek to quantify interactions between the ice sheet and the ocean

INVESTIGATIONS OF MORPHOLOGY AND CHEMICAL COMPOSITION OF ELECTRO-IMPULSE POLISHED SURFACE OF CARBON AND CORROSION-RESISTANT STEEL

The paper presents results of the investigations pertaining to morphology and chemical composition of thin surface layer of structural carbon and corrosion-resistant steel after the process of electro-impulse polishing. It has been established that removal of metal being polished occurs due to anode processes on the treated surface that leads to formation of surface films that can have different nature and thicknesses.  The paper reveals that under conditions of electro-impulse polishing anodic dissolution of steel takes place with direct participation of anions of electrolyte solution

MECHANIZM OF ANODE DISSOLVING OF CORROSION-RESISTING AND STRUCTURAL CARBON STEELS UNDER ELECTROPULSE POLISHING

In this article were suggested the schemes of anode processes, taking into account the nature of metals, anion structure, pH solution of electrolyte and anode potential by electropulse polishing of corrosion- resisting and structural carbon steels.It is shown and experimentally confirmed, that under conditions of electropulse polishing of anode dissolving of metals, which are contained into corrosion-resisting and structural carbon steels, carried out according to mechanism of complex formation through a set of series and series-parallel of intermediate stages. In the 1st stage on the surface of metals adsorption complexes with participation of chemisorption molecules of water are formed. In the next stages anions of electrolyte’s solution and molecules of water take part. In final stage of dissolving on the surface of anode soluble compounds are formed, which by transition into solution into simple ions are dissociated. It is determined that by electrical-impulse polishing in dissolving of components of corrosion-resisting carbon steels the important role play chemical processes, and anode dissolving of metals take place in the field of mixed electrochemical and diffusion kinetics . Diffusion limitations appear as a result of difficult ion mass transfer through surface salt, oxide and hydro-oxide and absorption-phase coatings

Determination of aryl-porphyrins binding constants to biological structures by indirect spectral approach

Молекулярная биофизик

GenEng3_04KharkovLO

Abstract -Y chromosomes from representative sample of Eastern Ukrainians (94 individuals) were analyzed for composition and frequencies of haplogroups, defined by 11 biallelic loci located in non-recombining part of the chromosome ( SRY1532 , YAP , 92R7 , DYF155S2 , 12f2 , Tat , M9 , M17 , M25 , M89 , and M56 ). In the Ukrainian gene, pool six haplogroups were revealed: E, F (including G and I), J, N3, P, and R1a1. These haplogroups were earlier detected in a study of Y-chromosome diversity on the territory of Europe as a whole. The major haplogroup in the Ukrainian gene pool, haplogroup R1a1 (earlier designated HG3), accounted for about 44% of all Y chromosomes in the sample examined. This haplogroup is thought to mark the migration patterns of the early Indo-Europeans and is associated with the distribution of the Kurgan archaeological culture. The second major haplogroup is haplogroup F (21.3%), which is a combination of the lineages differing by the time of appearance. Haplogroup P found with the frequency of 9.6%, represents the genetic contribution of the population originating from the ancient autochthonous population of Europe. Haplogroups J and E (11.7 and 4.2%, respectively) mark the migration patterns of the Middle-Eastern agriculturists during the Neolithic. The presence of the N3 lineage (9.6%) is likely explained by a contribution of the assimilated Finno-Ugric tribes. The data on the composition and frequencies of Y-chromosome haplogroups in the sample studied substantially supplement the existing picture of the male lineage distribution in the Eastern Slav population

Scales and structure of frontal adjustment and freshwater export in a region of freshwater influence

Sea surface temperature satellite imagery and a regional hydrodynamic model are used to investigate the variability and structure of the Liverpool Bay thermohaline front. A statistically based water mass classification technique is used to locate the front in both data sets. The front moves between 5 and 35 km in response to spring-neap changes in tidal mixing, an adjustment that is much greater than at other shelf-sea fronts. Superimposed on top of this fortnightly cycle are semi-diurnal movements of 5-10 km driven by flood and ebb tidal currents. Seasonal variability in the freshwater discharge and the density difference between buoyant inflow and more saline Irish Sea water give rise to two different dynamical regimes. During winter, when cold inflow reduces the buoyancy of the plume, a bottom-advected front develops. Over the summer, when warm river water provides additional buoyancy, a surface-advected plume detaches from the bottom and propagates much larger distances across the bay. Decoupled from near-bed processes, the position of the surface front is more variable. Fortnightly stratification and re-mixing over large areas of Liverpool Bay is a potentially important mechanism by which freshwater, and its nutrient and pollutant loads, are exported from the coastal plume system. Based on length scales estimated from model and satellite data, the erosion of post-neap stratification is estimated to be responsible for exporting approximately 19% of the fresh estuarine discharge annually entering the system. Although the baroclinic residual circulation makes a more significant contribution to freshwater fluxes, the episodic nature of the spring-neap cycle may have important implications for biogeochemical cycles within the ba