Reexamination of a Bound on the Dirac Neutrino Magnetic Moment from the Supernova Neutrino Luminosity

The neutrino helicity-flip process under the conditions of the supernova core is reinvestigated. Instead of the uniform ball model for the SN core used in previous analyses, realistic models for radial distributions and time evolution of physical parameters in the SN core are considered. A new upper bound on the Dirac neutrino magnetic moment is obtained from the limit on the supernova core luminosity for nu_R emission.Comment: 13 pages, LaTeX, 8 EPS figures, submitted to Int. J. Mod. Phys.

Quaternized and Unmodified Chitosans: Hydrodynamic Properties

Molecular properties of N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan (modified chitosan) series with the averaged quaternization degree 90% have been studied in comparison with the unmodified chitosan series by the method of translation isothermal diffusion, viscometry and static light scattering in dilute solutions in 0.33M CH3COOH+0.2M.CH3COONa at pH 3.54. Molecular mass, translation diffusion coefficient, and hydrodynamic size of the homologues samples in the modified/unnmodified series have been determined as well as their chain rigidity and Mark-Kuhn-Houwink equations at acidic pH. It was established that the size of modified chitosan molecules might be smaller than the initial polysaccharide of an equal polymerization degree in the same solvent, which was explained by the change of thermodynamic conditions and the change of the ratio of thermodynamic/electrostatic contributions to the total chain rigidity. Quaternized chitosan molecules displayed the different hydrodynamic behavior in 0.33M CH3COOH+0.2M.CH3COONa and in 0.2M NaCl (neutral pH). Solution properties of quaternized chitosan at neutral pH had been identified as the concentration dependent. The threshold influence of the secondary amino group protonation on the hydrodynamic properties of modified chitosan molecules was detected in 0.2M NaCl at the solute concentration range 0.001-0.004 g/cm3

The Exact Electron Propagator in a Magnetic Field as the Sum over Landau Levels on a Basis of the Dirac Equation Exact Solutions

The exact propagator for an electron in a constant uniform magnetic field as the sum over Landau levels is obtained by the direct derivation by standard methods of quantum field theory from exact solutions of the Dirac equation in the magnetic field. The result can be useful for further development of the calculation technique of quantum processes in an external active medium, particularly in the conditions of moderately large field strengths when it is insufficient to take into account only the ground Landau level contribution.Comment: 9 pages, LaTeX; v2: 3 misprints corrected, a note and 1 reference added; to appear in Int. J. Mod. Phys.

Electroresponsive Polyelectrolyte Brushes Studied by Self-Consistent Field Theory

End-grafting of polyelectrolyte chains to conducting substrates offers an opportunity to fabricate electro-responsive surfaces capable of changing their physical/chemical properties (adhesion, wettability) in response to applied electrical voltage. We use a self-consistent field numerical approach to compare the equilibrium properties of tethered strong and weak (pH-sensitive) polyelectrolytes to applied electrical field in both salt-free and salt-containing solutions. We demonstrate that both strong and weak polyelectrolyte brushes exhibit segregation of polyions in two populations if the surface is oppositely charged with respect to the brush. This segregation gives rise to complex patterns in the dependence of the brush thickness on salt concentration. We demonstrate that adjustable ionization of weak polyelectrolytes weakens their conformational response in terms of the dependence of brush thickness on the amplitude of the applied voltage

Fe-Si biominerals in the Vilyuchinskie hot springs, Kamchatka Peninsula, Russia

The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchinskaya hydrothermal system, Kamchatka Peninsula, Russia, were investigated. The Vilyuchinskie hot springs had a discharge temperature of 55–56°C and Na-Ca-HCO3-type waters rich in silicic and boric acids. Water and biomats had high concentrations of Fe, Mn, Sr, and As. Enumeration of total bacterial abundance (TBA) demonstrated a low density of bacterial populations. However, the fractions of metabolically active bacteria and respiring iron-oxidizing bacteria in the hot-spring water were high, comprising 68 and 21% of TBA, respectively. Scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDX) showed that unicellular rod-shaped bacteria about 5-μm long predominated in the brown biomats. The mineral capsules of these bacteria contained large amounts of Fe and Si. Extracellular and intracellular particles were observed by transmission electron microscopy. Fe-oxidizing bacteria were isolated from the biomats on agar plates with selective medium. Therefore, it can be concluded that microorganisms inhabiting the biomats of the Vilyuchinskie hot springs are essential for the deposition of Fe-minerals at neutral pH. [Int Microbiol 2004; 7(3):193–198

Metasomatized hazburgite xenoliths from Avacha volcano as fragments of mantle wedge of the Kamchatka arc: Implication for the metasomatic agent

金沢大学理工研究域自然システム学系Abundant peridotite xenoliths have been found in pyroclasitics of Avacha (Avachinsky) volcano, the south Kamchatka arc, Russia. They are mostly refractory harzburgite with or without clinopyroxene: the Fo of olivine and Cr/(Cr+Al) atomic ratio of spinel range from 91 to 92 and from 0.5 to 0.7, respectively. They are metasomatized to various extents, and the metasomatic orthopyroxene has been formed at the expense of olivine. The metasomatic orthopyroxene, free of deformation and exsolution, is characterized by low contents of CaO and Cr2O3. The complicated way of replacement possibly indicates low viscosity of the metasomatic agent, namely hydrous fluids released from the relatively cool slab beneath the south Kamchatka arc. This is a good contrast to the north Kamchatka arc, where the slab has been hot enough to provide slab-derived melts. High content of total orthopyroxene, 40 vol% on average, in metasomatized harzburgite from Avacha suggests silica enrichment of the mantle wedge, and is equivalent to some subcratonic harzburgite. Some subcratonic harzburgites therefore could have been formed by transportation of subarc metasomatized peridotites to a deeper part of the upper mantle

Hydrothermal Mineral Formation Systems of Kamchatka and the Biomineralization

Institute of Volcanology, FEB RAS金沢大学大学院自然科学研究科Scedule:17-18 March 2003, Vemue: Kanazawa, Japan, Kanazawa Citymonde Hotel, Project Leader : Hayakawa, Kazuichi, Symposium Secretariat: XO kamata, Naoto, Edited by:Kamata, Naoto

Chemical and microbiological investigations of hot spring deposits found at the hydrothermal systems of Kamchatka Peninsula, Russia

Graduate School of Natural Science and Technology, Kanazawa UniversityDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityInstitute of Volcanology of Far Eastern Division of Russian Academy of SciencesDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityChemical and biological characteristics of hot spring water, travertines and microbial mats collected from seven hydrothermal systems of the Kamchatka Peninsula, Russia are described. Water quality of the Vilyuchinskie hot springs was almost the same as those of Tazaki et al. (2003). Elemental concentration of hot spring waters was mainly composed of Na, K, Ca, and Mg with high contents of Fe, As, and Sr. The structure and elemental composition of travertine and biomats were studied with optical microscopy, ED-XRF, XRD, and EPMA. High content of As (43.88 wt%) was found in the deposits and biomats of the Nalychevskie hot springs. Extremely high concentration of Cd of 9.56 wt% was detected in the deposits of the Paratunskie hot springs. Traces of mercury (0.57 wt%) were found in the soft parts of biomats from the Apapelskie-1 hot springs. Optical microscopic observation of thin section of Oksinskie, Apapelskie, and Vilyuchinskie biomats revealed laminated structures. Soft parts of biomats mainly consist of cyanobacteria Anabaena spp. and green algae. A calcareous travertine of the Vilyuchinskie hot springs recorded the evidences of a long-term transition of water chemistry and periodic changes of environmental conditions such as water flux from the well and rainfall. Intensive hydrothermal alteration was observed in the Dachnye hot springs. Optical microscopic observation of microbial mats revealed diversity of microorganisms both in free-living forms and in association with mineral particles. Metabolically active cells were detected in the microbial mats indicating the impact of bacteria to the geochemical processes in the surroundings environments