Seismic attractor can assist in finding of geothermal area?

Abstract

The seismic active zone is a distributed system consisting of various subareas. To understand a state of the system during a given period of time so called ‘the linear gradient frame’ technique was developed to search the stable characteristics for subareas. The search is based on analysis of geographic components, least-squares inversion and statistical estimators of seismic data. The stable subarea includes hypocenters of earthquakes, the space-time trajectories of which are restricted by a certain domain (seismic attractor). Fractal structures obtained in south of Iceland are in an agreement with geological history. The results are promising for the geothermal exploration.     

Milling of Carbide-Steel Powder Components and Their Mixtures in an Attrition Mill

Milling of wear-resistant steel and titanium carbide powders is studied with an attrition mill rotation rate of 980 rpm. The physical and technological properties of powders and particle size are determined. Particle shape and the change in material chemical composition during milling are studied. It is established that steel powder cannot be milled to particle sizes less than 3.6 μm whereas a mixture of steel and titanium carbide can be milled to a fine state (0.3 μm). Powders with a size of about 1 μm neither flow nor are formable. Use of benzene as a milling medium makes it possible to prevent steel powder oxidation, but the carbon content in titanium carbide decreases. During milling of the main part of the charge to a fine state rather large steel particles (up to 50 μm) remain.     

Orientation-controlled,low-temperature plasma growth and applications of h-BN nanosheets

Nano Research - Dimensionality and orientation of hexagonal boron nitride (h-BN) nanosheets are promising to create and control their unique properties for diverse applications. However,...     

Overall water splitting over Pt/TiO2 catalyst with Ce/Ce shuttle charge transfer system

The experiments on photocatalytic hydrogen production from aqueous solution of Ce₂(SO₄)₃ and photocatalytic oxygen production from aqueous solution of Ce(SO₄)₂ were carried out on the same catalyst platinized Degussa P25. Pure oxygen was shown to evolve from Ce(SO₄)₂ solution and pure hydrogen from Ce₂(SO₄)₃ solution with stoichiometric formation of Ce₂(SO₄)₃ and Ce(SO₄)₂, respectively.     

Effects of viscosity-dependent diffusion in the analysis of rotating disk electrode data

This paper demonstrates the application of a modified Levich equation for chemical systems with varying viscosity. A commonly used technique to analyze rotating disc electrode (RDE) experiments is to fit the data to the Levich equation assuming a constant effective diffusion coefficient which may be valid for conditions where the viscosity does not vary significantly (less than an order of magnitude). However, most diffusion coefficient models (e.g. Stokes–Einstein) show an inverse relationship with viscosity which consequently indicates that a constant effective diffusion coefficient may result in poorer model-to-data agreement. Here, data are presented for a series of RDE experiments for the electrodissolution of Cu in phosphoric acid, water and glycerin based baths. Viscosity changes of greater than one order of magnitude allow for testing the assumption of a constant effective diffusion coefficient. The collected data, as well as data published elsewhere, can be explained by a modified Levich equation which takes into account the viscosity dependence of the diffusion coefficient.     

Mitochondrial Dysfunction in Vascular Wall Cells and Its Role in Atherosclerosis

Altered mitochondrial function is currently recognized as an important factor in atherosclerosis initiation and progression. Mitochondrial dysfunction can be caused by mitochondrial DNA (mtDNA) mutations, which can be inherited or spontaneously acquired in various organs and tissues, having more or less profound effects depending on the tissue energy status. Arterial wall cells are among the most vulnerable to mitochondrial dysfunction due to their barrier and metabolic functions. In atherosclerosis, mitochondria cause alteration of cellular metabolism and respiration and are known to produce excessive amounts of reactive oxygen species (ROS) resulting in oxidative stress. These processes are involved in vascular disease and chronic inflammation associated with atherosclerosis. Currently, the list of known mtDNA mutations associated with human pathologies is growing, and many of the identified mtDNA variants are being tested as disease markers. Alleviation of oxidative stress and inflammation appears to be promising for atherosclerosis treatment. In this review, we discuss the role of mitochondrial dysfunction in atherosclerosis development, focusing on the key cell types of the arterial wall involved in the pathological processes. Accumulation of mtDNA mutations in isolated arterial wall cells, such as endothelial cells, may contribute to the development of local inflammatory process that helps explaining the focal distribution of atherosclerotic plaques on the arterial wall surface. We also discuss antioxidant and anti-inflammatory approaches that can potentially reduce the impact of mitochondrial dysfunction.     

Reversible Hydriding of LaNi5 − xAlx ― Pd Composites in the Presence of Carbon Monoxide

Carbon monoxide is one of the most dangerous impurities in gas mixtures involved in the hydriding of intermetallic compounds, and up to the present time the concentration limit 0.03 vol.% CO has not been surmounted. The objective of the present work was to investigate the possibility of reversibly hydriding LaNi_{5 ? x} Al _x ― Pd composites in gas mixtures containing up to 5 vol.% CO. The experimental specimens were mixtures of palladium black and LaNi₅, LaNi_4.7Al_0.3, LaNi_4.5Al_0.5, LaNi_4.2Al_0.8, and LaNi₄Al powders cold pressed at 300 MPa. The intermetallics were preliminarily dispersed by hydriding and mechanical grinding. The concentration of palladium black in the powder mixtures was varied from 0 to 1.5 mass%. It was shown that it is possible to reversibly hydride LaNi_{5 ? x} Al _x ― Pd composites in mixtures of hydrogen and carbon monoxide containing up to 5 vol.% CO at the temperatures 423 and 473 K. It was established that alloying LaNi₅ with aluminum in amounts which raised the stoichiometric concentration above 0.5 stabilized the absorption properties of LaNi_{5 ? x} Al _x ― Pd in the presence of CO. The composition LaNi₄Al was optimal. Palladium additions to LaNi_{5 ? x} Al _x ― Pd composites also increased the stability of hydrogen absorption by the intermetallic. It is noted that the effect of palladium was more positive than that of aluminum.

     

A new cytotoxic fatty acid (5<Emphasis Type="Italic">Z</Emphasis>,9<Emphasis Type="Italic">Z</Emphasis>)-22-methyl-5,9-tetracosadienoic acid and the sterols from the far Eastern sponge <Emphasis Type="Italic">Geodinella robusta</Emphasis>

A new fatty acid, (5Z,9Z)-22-methyl-5,9-tetracosadienoic acid (1a), and a rare fatty acid, (5Z,9Z)-23-methyl-5,9-tetracosadienoic acid (2a), the predominant constituents of the free fatty acid fraction from the lipids of the sponge Geodinella robusta, were isolated and partly separated by reversed phase high-performance liquid chromatography, followed by multifold crystallization from MeOH to give 1a and 2a in 70% and 60% purity, respectively. These fatty acids were identified as (5Z,9Z)-22-and (5Z,9Z)-23-methyl-5,9-tetracosadienoic acids by nuclear magnetic resonance techniques, including distortionless enhancement by polarization transfer, heteronuclear multiple quantum connectivity, and correlation spectroscopy experiments, as well as from mass-spectrometric data for their methyl esters, the methyl esters of their perhydro derivatives, and their pyrrolidides. Mixtures of 1a and 2a showed cytotoxic activity against mouse Ehrlich carcinoma cells and a hemolytic effect on mouse erythrocytes. The sterol fraction from the same sponge was analyzed by gas liquid chromatography mass spectrometry, and 24-methylenecholesterol was identified as a main constituent of this fraction. The implications of the co-occurrence of membranolytic long-chain fatty acids and 24-methylenecholesterol as a main membrane sterol are discussed in terms of the phenomenon of biochemical coordination.