The work fluctuations of an oscillator in contact with a thermostat and driven out of equilibrium by an external force are studied experimentally and theoretically within the context of fluctuation ...theorems. The oscillator dynamics is modeled by a second order Langevin equation. Both the transient and stationary state fluctuation theorems hold and the finite time corrections are very different from those of a first order Langevin equation. The periodic forcing of the oscillator is also studied; it presents new and unexpected short time convergences. Analytical expressions are given in all cases.
Single crystals of LuAG:Ce, LuAG:Pr and un-doped LuAG were grown by the vertical Bridgman method and studied for radiation hardness under gamma-rays with doses in the range 10–105Gy (60Co). A wide ...absorption band peaking at around 600nm springs up in all three types of crystals after the irradiations. The second band peaking at around 375nm appears in both LuAG:Pr and un-doped LuAG. Compositional variations have been done to reveal the spectral behavior of induced color centers in more detail and to understand their origin. Similarities in behavior of Yb2+ centers in as-grown garnets are found, indicating that radiation induced color centers can be associated with residual trace amounts of Yb present in the raw materials. Un-doped LuAG and LuAG:Ce demonstrate moderate radiation hardness (the induced absorption coefficients being equal to 0.05–0.08cm−1 for accumulated doses of 103–104Gy), while LuAG:Pr is less radiation hard. The ways to improve the radiation hardness are discussed.
► Radiation hardness of LuAG:Ce and LuAG:Pr single crystals was examined. ► The role of residual impurities was analyzed. ► Importance of the purity control in respect to Yb has been demonstrated.
We measure the energy fluctuations of a Brownian particle confined by an optical trap in an aging gelatin after a very fast quench (less than 1 ms). The strong nonequilibrium fluctuations due to the ...assemblage of the gel are interpreted, within the framework of fluctuation theorem, as a heat flux from the particle towards the bath. We derive an analytical expression of the heat probability distribution, which fits the experimental data and satisfies a fluctuation relation similar to that of a system in contact with two baths at different temperatures.
Adeno-associated viruses (AAVs) are a promising system for therapeutic gene delivery to neurons in a number of neurodegenerative conditions including spinal cord injuries (SCIs). Considering the role ...of macrophages and glia in the progression of 'secondary damage', we searched for the optimal vectors for gene transfer to both neurons and glia following contusion SCI in adult rats. Contusion models share many similarities to most human spinal cord traumas. Several AAV serotypes known for their neuronal tropism expressing enhanced green-fluorescent protein (GFP) were injected intraspinally following thoracic T10 contusion. We systematically compared the transduction efficacy and cellular tropism of these vectors for neurons, macrophages/microglia, oligodendrocytes, astrocytes and NG2-positive glial cells following contusion SCI. No additional changes in inflammatory responses or behavioral performance were observed for any of the vectors. We identified that AAV-rh10 induced robust transduction of both neuronal and glial cells. Even though efficacy to transduce neurons was comparable to already established AAV-1, AAV-5 and AAV-9, AAV-rh10 transduced significantly higher number of macrophages/microglia and oligodendrocytes in damaged spinal cord compared with other serotypes tested. Thus, AAV-rh10 carries promising potential as a gene therapy vector, particularly if both the neuronal and glial cell populations in damaged spinal cord are targeted.
The formation of the Iroshnikov-Kraichnan spectrum in the inertial interval has been shown for two-dimensional β-plane decaying homogeneous magnetohydrodynamic turbulence. An expression for the ...wavenum-ber that characterizes the boundary between the inertial interval of the Iroshnikov-Kraichnan spectrum and the region of existence of Rossby waves has been obtained. The self-similar decay of the Iroshnikov- Kraichnan spectrum in time has been investigated. The violation of the self-similar decay of the total energy spectrum and the formation of the Kolmogorov spectrum in the inertial range of the kinetic energy have been found at large time intervals. The inverse cascade of the kinetic energy characteristic of the detected Kolm-ogorov spectrum provides the origin of zonal flows.
THE MARTIAN ATMOSPHERIC BOUNDARY LAYER Petrosyan, A.; Galperin, B.; Larsen, S. E. ...
Reviews of geophysics (1985),
September 2011, Letnik:
49, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The planetary boundary layer (PBL) represents the part of the atmosphere that is strongly influenced by the presence of the underlying surface and mediates the key interactions between the atmosphere ...and the surface. On Mars, this represents the lowest 10 km of the atmosphere during the daytime. This portion of the atmosphere is extremely important, both scientifically and operationally, because it is the region within which surface lander spacecraft must operate and also determines exchanges of heat, momentum, dust, water, and other tracers between surface and subsurface reservoirs and the free atmosphere. To date, this region of the atmosphere has been studied directly, by instrumented lander spacecraft, and from orbital remote sensing, though not to the extent that is necessary to fully constrain its character and behavior. Current data strongly suggest that as for the Earth's PBL, classical Monin‐Obukhov similarity theory applies reasonably well to the Martian PBL under most conditions, though with some intriguing differences relating to the lower atmospheric density at the Martian surface and the likely greater role of direct radiative heating of the atmosphere within the PBL itself. Most of the modeling techniques used for the PBL on Earth are also being applied to the Martian PBL, including novel uses of very high resolution large eddy simulation methods. We conclude with those aspects of the PBL that require new measurements in order to constrain models and discuss the extent to which anticipated missions to Mars in the near future will fulfill these requirements.
After introducing a new form of density-functional theory for the ab initio description of electronic systems in contact with a molecular liquid environment, we present the first detailed study of ...the impact of a solvent on the surface chemistry of Cr2O3, the passivating layer of stainless steel alloys. In comparison to a vacuum, we predict that the presence of water has little impact on the adsorption of chloride ions to the oxygen-terminated surface but has a dramatic effect on the binding of hydrogen to that surface. These results indicate that the dielectric screening properties of water are important to the passivating effects of the oxygen-terminated surface.
New chemical analogs of triglycine sulfate Ghazaryan, V.V.; Fleck, M.; Petrosyan, A.M.
Journal of crystal growth,
09/2014, Letnik:
401
Journal Article, Conference Proceeding
Recenzirano
Triglycine sulfate (TGS) and its analogs can be presented by the molecular structure AH(A⋯AH)Y, where A is an amino acid (glycine in TGS) in zwitter-ionic form, AH is a protonated cationic amino ...acid, (A⋯AH) is a dimeric cation, where A and AH are connected by a short hydrogen bond, and Y is a divalent anion. Doing research on amino acid hexafluorosilicates we obtained a series of salts with different compositions, including four hexafluorosilicate salts which chemically are analogs of triglycine sulfate. Those are GlyH(Gly⋯GlyH)SiF6 (I), SarH(Sar⋯SarH)SiF6·2H2O (II), l-AlaH(l-Ala⋯l-AlaH)SiF6·H2O (III) and l-ProH(l-Pro⋯l-ProH)SiF6·H2O (IV). We have already published our results on crystals (II) and (III). In this work we report our results on the crystals (I) and (IV).
•We found four amino acid hexafluorosilicate salts in 3:1 compositions.•These salts are chemical analogs of triglycine sulfate.•Crystals and molecular structures are given.
A Dynamic Network Game of the Fintech Industry Yeung, David W. K.; Petrosyan, Leon A.; Zhang, Ying-Xuan
Journal of the Operations Research Society of China (Internet),
03/2024, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Economies of scale, economies of scope, and technology spillover are decisive economic elements that are crucial to the development in the Fintech industry. These positive externalities are often ...realized through network links. In this paper, we present a dynamic network of financial firms which exhibits these decisive elements. The network game equilibria are characterized. A Pareto efficient solution involving collaboration of all firms is provided. To obtain a fair-share distribution of cooperative gains, the Shapley value is adopted as the sharing mechanism. Payoff distribution mechanisms which guarantee the fulfilment of the Shapley value distribution in each stage of the cooperation duration are derived.
National Research and Education Networks (NRENs) are pivotal in modern research and education, providing a dynamic ecosystem for academic and scientific communities. These networks form the backbone ...for crucial infrastructures and services, propelling research, education, and innovation. This article explores the role of monitoring and advanced emulation in enhancing NREN performance. The experiences of ASNET-AM, the Armenian NREN, in leveraging these techniques are presented, highlighting the benefits and challenges.
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