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Dynamic Covalent Chemistry for Synthetic Molecular Machines
The first and only exhaustive review of the theory, thermodynamic fundamentals, mechanisms, and design principles of dynamic covalent systems Dynamic Covalent Chemistry: Principles, Reactions, and Applications presents a comprehensive ..
THE USE OF PRIVATE LANDS IN THE U.S. FOR OUTDOOR RECREATION: RESULTS OF A NATIONWIDE SURVEY
Land Economics/Use, Resource /Energy Economics and Policy,
Shielding from Space Radiations
This Final Progress Report for NCC-1-178 presents the details of the engineering development of an analytical/computational solution to the heavy ion transport equation in terms of a multi-layer Green's function formalism as applied to the Small Spacecraft Technology Initiative (SSTI) program. The mathematical developments are recasted into a series of efficient computer codes for space applications. The efficiency of applied algorithms is accomplished by a nonperturbative technique of extending the Green's function over the solution domain. The codes may also be applied to the accelerator boundary conditions to allow code validation in laboratory experiments. Correlations with experiments for the isotopic version of the code with 59 and 80 isotopes present for a two layers target material in water has been verified
Metal Investments: Distrust Killer or Inflation Hedging?
This study investigates long run metals properties using the extended version of Mccown and Zimmerman (2006) multifactor CAPM-model. By adding extra explanatory variables we improve the explanation power of the existing model in terms of R-squared. Taking German invertors\u27 perspective and using prices of gold, silver and platinum over the period 1985-2010, our findings show that metals are true zero market beta assets. We further show that the determinants of metal prices are dependent on market conditions reflected by different betas for stable and crisis periods. The inclusion of a new variable, economic sentiment index in the models shows explanation power for gold. Its significant negative effect reveals gold position as a safe haven in times of distrust. Our results show that gold is the only metal co-integrated with the consumer price index (CPI) of Germany, thus the only metal providing inflation hedging to the German investor in the long run. Our results are consistent with the theories that metals provide long term hedge against unemployment
Two-dimensional radiation-hydrodynamic model for limit-cycle oscillations of luminous accretion disks
We investigate the time evolution of luminous accretion disks around black
holes, conducting the two-dimensional radiation-hydrodynamic simulations. We
adopt the alpha prescription for the viscosity. The radial-azimuthal component
of viscous stress tensor is assumed to be proportional to the total pressure in
the optically thick region, while the gas pressure in the optically thin
regime. The viscosity parameter, alpha, is taken to be 0.1. We find the
limit-cycle variation in luminosity between high and low states. When we set
the mass input rate from the outer disk boundary to be 100 L_E/c^2, the
luminosity suddenly rises from 0.3L_E to 2L_E, where L_E is the Eddington
luminosity. It decays after retaining high value for about 40 s. Our numerical
results can explain the variation amplitude and duration of the recurrent
outbursts observed in microquasar, GRS 1915+105. We show that the
multi-dimensional effects play an important role in the high-luminosity state.
In this state, the outflow is driven by the strong radiation force, and some
part of radiation energy dissipated inside the disk is swallowed by the black
hole due to the photon-trapping effects. This trapped luminosity is comparable
to the disk luminosity. We also calculate two more cases: one with a much
larger accretion rate than the critical value for the instability and the other
with the viscous stress tensor being proportional to the gas pressure only even
when the radiation pressure is dominant. We find no quasi-periodic light
variations in these cases. This confirms that the limit-cycle behavior found in
the simulations is caused by the disk instability.Comment: 6 pages, 4 figures, accepted for publication in ApJ (ApJ 01 April
2006, v640, 2 issue
Shielding from space radiations
This Progress Report covering the period of 1 June 1993 to 1 Dec. 1993 presents the development of an analytical solution to the heavy ion transport equation in terms of a one-layer Green's function formalism. The mathematical developments are recasted into an efficient computer code for space applications. The efficiency of this algorithm is accomplished by a nonperturbative technique of extending the Green's function over the solution domain. The code may also be applied to accelerator boundary conditions to allow code validation in laboratory experiments. Results from the isotopic version of the code with 80 isotopes present for a single layer target material, for the case of an Iron beam projectile at 600 MeV/nucleon in water is presented
Shielding from space radiations
This Progress Report covering the period of 1 June 1993 to 1 Dec. 1993 presents the development of an analytical solution to the heavy ion transport equation in terms of a one-layer Green's function formalism. The mathematical developments are recasted into an efficient computer code for space applications. The efficiency of this algorithm is accomplished by a nonperturbative technique of extending the Green's function over the solution domain. The code may also be applied to accelerator boundary conditions to allow code validation in laboratory experiments. Results from the isotopic version of the code with 80 isotopes present for a single layer target material, for the case of an iron beam projectile at 600 MeV/nucleon in water is presented
Shielding from space radiations
This Progress Report covering the period of December 1, 1992 to June 1, 1993 presents the development of an analytical solution to the heavy ion transport equation in terms of Green's function formalism. The mathematical development results are recasted into a highly efficient computer code for space applications. The efficiency of this algorithm is accomplished by a nonperturbative technique of extending the Green's function over the solution domain. The code may also be applied to accelerator boundary conditions to allow code validation in laboratory experiments. Results from the isotopic version of the code with 59 isotopes present for a single layer target material, for the case of an iron beam projectile at 600 MeV/nucleon in water is presented. A listing of the single layer isotopic version of the code is included
Hepatic glucokinase promoter polymorphism is associated with hepatic insulin resistance in Asian Indians.
BACKGROUND: The role of glucokinase (GCK) in the pathogenesis of maturity-onset diabetes of the young is well established. However, its role in the common form of type 2 diabetes is far from convincing. We investigated the role of the G-to-A polymorphism in the hepatic GCK promoter on insulin sensitivity and beta cell function in 63 normotensive Asian Indians with normal glucose tolerance. As proposed by Matsuda and DeFronzo, hepatic insulin sensitivity (ISI(H)) and total body insulin sensitivity (ISI(M)) were estimated from the oral glucose tolerance test. Beta cell function was estimated using %B from the Homeostasis Model Assessment and insulingenic index (dI/dG). RESULT: We identified 38 GG, 24 GA, and one AA subjects. The AA subject was pooled with the GA subjects during the analysis. No difference was noted in the demographic features between the two genotypic groups (GG vs. GA/AA). Compared to the GG group, the GA/AA group had a lower ISI(H) (p=0.002), a lower ISI(M) (p=0.009), a higher %B (p=0.014), and a higher dI/dG (p=0.030). Multivariate analysis revealed that this polymorphism is an independent determinant for ISI(H) (p=0.019) and along with age, waist-hip ratio, gender, and diastolic blood pressure accounted for 51.5% of the variation of ISI(H). However, this polymorphism was a weak, but independent determinant for ISI(M) (p=0.089) and %B (p=0.083). Furthermore, it had no independent effect on dI/dG (p=0.135). CONCLUSIONS: These data suggest that the G-to-A polymorphism in the hepatic GCK promoter is associated with hepatic insulin resistance in Asian Indians
New Analytical Formula for Supercritical Accretion Flows
We examine a new family of global analytic solutions for optically thick
accretion disks, which includes the supercritical accretion regime. We found
that the ratio of the advection cooling rate, , to the viscous
heating rate, , i.e., , can be
represented by an analytical form dependent on the radius and the mass
accretion rate. The new analytic solutions can be characterized by the
photon-trapping radius, \rtrap, inside which the accretion time is less than
the photon diffusion time in the vertical direction; the nature of the
solutions changes significantly as this radius is crossed. Inside the trapping
radius,
approaches , which corresponds to the advection-dominated
limit (), whereas outside the trapping radius, the radial dependence
of changes to , which corresponds to the
radiative-cooling-dominated limit. The analytical formula for derived here
smoothly connects these two regimes. The set of new analytic solutions
reproduces well the global disk structure obtained by numerical integration
over a wide range of mass accretion rates, including the supercritical
accretion regime. In particular, the effective temperature profiles for our new
solutions are in good agreement with those obtained from numerical solutions.
Therefore, the new solutions will provide a useful tool not only for evaluating
the observational properties of accretion flows, but also for investigating the
mass evolution of black holes in the presence of supercritical accretion flows.Comment: 14 pages, 7 figures, accepted for publication in the Astrophysical
Journa
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