20 research outputs found
Determinants of Trust in B2C E-commerce and Their Relationship with Consumer Online Trust
Pure Gauge Configurations and Tachyon Solutions to String Field Theories Equations of Motion
In constructions of analytical solutions to open string field theories pure
gauge configurations parameterized by wedge states play an essential role.
These pure gauge configurations are constructed as perturbation expansions and
to guaranty that these configurations are asymptotical solutions to equations
of motions one needs to study convergence of the perturbation expansions. We
demonstrate that for the large parameter of the perturbation expansion these
pure gauge truncated configurations give divergent contributions to the
equation of motion on the subspace of the wedge states. We perform this
demonstration numerically for the pure gauge configurations related to tachyon
solutions for the bosonic and the NS fermionic SFT. By the numerical
calculations we also show that the perturbation expansions are cured by adding
extra terms. These terms are nothing but the terms necessary to make valued the
Sen conjectures.Comment: 30 pages, 9 figures, references added and conclusion extende
Ionic liquids at electrified interfaces
Until recently, âroom-temperatureâ (<100â150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)â(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of âfirst-generationâ room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the âlater generationâ RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in âcocktailsâ of oneâs choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost âuniversalâ solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) âsister-systemsâ.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules
Enchytraeidae (Annelida: Oligochaeta) from the North-Western Caucasus, Russia, with the Description of <i>Fridericia gongalskyi</i> sp. nov.
The first list of terrestrial enchytraeids of the north-western Caucasus includes 24 species belonging to seven genera. A new enchytraeid species of the genus Fridericia, Fridericia gongalskyi sp. nov., is described. It clearly differs from other species of the genus by the presence of only three pairs of preclitellar nephridia, the postclitellar position of the chylus cells and two elongated spermathecal diverticula. The phylogenetic relations of the new species within the genus are discussed
Influence of ultrafine-grained structure parameters on the annealing-induced hardening and deformation-induced softening effects in pure Al
This work investigates the influence of parameters of initial ultrafine-grained (UFG) structure in commercially pure (CP) Al on annealing-induced hardening (AIH) and deformation-induced softening (DIS) effects. UFG structures were formed via processing CP Al by various methods of severe plastic deformation (high pressure torsion (HPT), equal channel angular pressing (ECAP) and combination of ECAP and cold rolling (CR)). AIH and DIS effects are observed in all the studied UFG structures. However, HPT Al demonstrates large increase of strength due to annealing and drastic gain of ductility after subsequent additional deformation whereas in ECAP Al and ECAP + CR Al both effects are much less pronounced. Microstructure characterization by X-ray diffraction (XRD) analysis, electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) was performed for HPT Al and ECAP + CR Al in the three studied states: before and after annealing and after annealing and subsequent additional deformation. Analysis of microstructure evolution during annealing and subsequent additional deformation shows that the key microstructure parameter which is responsible for AIH and DIS effect is the change of dislocation density in grain interior in ECAP + CR Al, whereas in HPT Al the effects are related to the change of dislocation density at/near grain boundaries. In addition, outstanding combination of high strength (âŒ210 MPa), high electrical conductivity (âŒ62 %IACS) with sufficiently good ductility (7â10 %) and thermal stability (up to 150°Х, at least) was achieved for ECAP + CR Al after annealing at 150 °C, 1h
Optimization of strength-electrical conductivity properties in Alâ2Fe alloy by severe plastic deformation and heat treatment
Effect of the eutectic Al-(Ce,La) phase morphology on microstructure, mechanical properties, electrical conductivity and heat resistance of Al-4.5(Ce,La) alloy after SPD and subsequent annealing
A RoomâTemperature Verweyâtype Transition in Iron Oxide, FeO
Functional oxides whose physicochemical properties may be reversibly changed at standard conditions are potential candidates for the use in nextâgeneration nanoelectronic devices. To date, vanadium dioxide (VO) is the only known simple transitionâmetal oxide that demonstrates a nearâroomâtemperature metalâinsulator transition that may be used in such appliances. In this work, we synthesized and investigated the crystals of a novel mixedâvalent iron oxide with an unconventional FeO stoichiometry. Near 275â
K, FeO undergoes a Verweyâtype chargeâordering transition that is concurrent with a dimerization in the iron chains and a following formation of new FeâFe chemical bonds. This unique feature highlights FeO as a promising candidate for the use in innovative applications. We established that the minimal FeâFe distance in the octahedral chains is a key parameter that determines the type and temperature of charge ordering. This model provides new insights into chargeâordering phenomena in transitionâmetal oxides in general
Vertebral triangle of doctor A.N. Kazantsev - double vertebral artery in V3 segment
We have described a variant of the structure of the vertebral artery. In the V3 segment, the vertebral artery bifurcated and then joined again. This building looks like a triangle. Such anatomy has not been previously described in the world literature. By the right of the first description, this anatomical formation was called the «vertebral triangle of Dr A.N. Kazantsev». This discovery was made during stenting of the V4 segment of the left vertebral artery in the most acute period of stroke
High-Tech Methods of Cytokine Imbalance Correction in Intervertebral Disc Degeneration
An important mechanism for the development of intervertebral disc degeneration (IDD) is an imbalance between anti-inflammatory and pro-inflammatory cytokines. Therapeutic and non-therapeutic approaches for cytokine imbalance correction in IDD either do not give the expected result, or give a short period of time. This explains the relevance of high-tech medical care, which is part of specialized care and includes the use of new resource-intensive methods of treatment with proven effectiveness. The aim of the review is to update knowledge about new high-tech methods based on cytokine imbalance correction in IDD. It demonstrates promise of new approaches to IDD management in patients resistant to previously used therapies, including: cell therapy (stem cell implantation, implantation of autologous cultured cells, and tissue engineering); genetic technologies (gene modifications, microRNA, and molecular inducers of IDD); technologies for influencing the inflammatory cascade in intervertebral discs mediated by abnormal activation of inflammasomes; senolytics; exosomal therapy; and other factors (hypoxia-induced factors; lysyl oxidase; corticostatin; etc.)