Particle Spectra and Mass Composition in the Ultra-High Energy Region in the Framework of the Galactic Origin of Cosmic Rays

The possibility for a self-consistent description of all the basic features of the observed cosmic ray spectra and primary composition variations in the energy range of $10^{15}\div 10^{20}$ eV within the Galactic origin scenario is examined. We assume the existence of Galactic sources that accelerate particles up to $\sim 3\cdot 10^{18}Z$ eV and take into account a highly inhomogeneous (fractal-like) distribution of matter and magnetic fields in the Galaxy that leads to extremely large free paths of particles ("L\'{e}vy flights"), along with an overwhelming contribution to the cosmic ray fluxes observed above $\sim 10^{18}$ eV from particles reaching the Solar System without scattering. Our scenario was refined on the basis of recent experimental results on primary mass composition. Model predictions, which could be verified with the improved high-precision measurements in the nearest future are discussed.Comment: 5 pages, 2 figures, 19th International Symposium on Very High Energy Cosmic Ray Interactions (22-27 August 2016). Moscow, Russia. P.N. Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS

Modelling Economic Impacts of Alternative International Climate Policy Architectures.A Quantitative and Comparative Assessment of Architectures for Agreement

This paper provides a quantitative comparison of the main architectures for an agreement on climate policy. Possible successors to the Kyoto protocol are assessed according to four criteria: economic efficiency; environmental effectiveness; distributional implications; and their political acceptability which is measured in terms of feasibility and enforceability. The ultimate aim is to derive useful information for designing a future agreement on climate change control.climate policy, integrated modelling, international agreements

Revisiting element removal for density-based structural topology optimization with reintroduction by Heaviside projection

We present a strategy grounded in the element removal idea of Bruns and Tortorelli [1] and aimed at reducing computational cost and circumventing potential numerical instabilities of density-based topology optimization. The design variables and the relative densities are both represented on a fixed, uniform finite element grid, and linked through filtering and Heaviside projection. The regions in the analysis domain where the relative density is below a specified threshold are removed from the forward analysis and replaced by fictitious nodal boundary conditions. This brings a progressive cut of the computational cost as the optimization proceeds and helps to mitigate numerical instabilities associated with low-density regions. Removed regions can be readily reintroduced since all the design variables remain active and are modeled in the formal sensitivity analysis. A key feature of the proposed approach is that the Heaviside functions promote material reintroduction along the structural boundaries by amplifying the magnitude of the sensitivities inside the filter reach. Several 2D and 3D structural topology optimization examples are presented, including linear and nonlinear compliance minimization, the design of a force inverter, and frequency and buckling load maximization. The approach is shown to be effective at producing optimized designs equivalent or nearly equivalent to those obtained without the element removal, while providing remarkable computational savings

Modelling Economic Impacts of Alternative International Climate Policy Architectures. A Quantitative and Comparative Assessment of Architectures for Agreement

This paper provides a quantitative comparison of the main architectures for an agreement on climate policy. Possible successors to the Kyoto protocol are assessed according to four criteria: economic efficiency; environmental effectiveness; distributional implications; and their political acceptability which is measured in terms of feasibility and enforceability. The ultimate aim is to derive useful information for designing a future agreement on climate change control.Climate Policy, Integrated Modelling, International Agreements

The Global Welfare Effects of GM Sugar Beet under Changing Sugar Policies

Since most of the recent agricultural biotechnology innovations have been developed by private companies, the central focus of societal interest is on the distribution of the gains from these technologies among all stakeholders. In a partial equilibrium model, assuming perfect corporate pricing strategies given the heterogeneous population of potential adopters, we model the worldwide introduction of GM sugar beet. The introduction is modelled under both the old and new CMO for sugar in the EU. We see GM sugar beet could bring great benefits to both consumers in the world and sugar beet producers even when the innovation is protected by intellectual property rights and the innovator uses his restricted monopoly to the full extend.GM, sugar beet, partial equilibrium, Agricultural and Food Policy, Crop Production/Industries,

Numerical Simulations And Laboratory Measurements In Hydraulic Jumps

Hydraulic jump is one of the most extended and effective mechanism for hydraulic energy dissipation. Usually, hydraulic jump characteristics have been studied through physical models. Nowadays, computational fluid dynamics (CFD) are an important tool that can help to analyze and to understand complex phenomena that involve high turbulence and air entrainment cases. Free and submerged hydraulic jumps with Froude numbers from 2.9 to 5.5 are studied in a rectangular channel downstream a sluice gate. Velocity measurements with different flow rates are carried out by using Acoustic Doppler Velocimeter (ADV) and Particle Image Velocimeter (PIV) instrumentations. In this paper, laboratory measurements are used to calibrate and to validate open source and commercial CFD programs. Air-water two-phase flows are considered in the simulations. The closure problem is solved by using different turbulence models. Water depths, hydraulic jumps lengths, velocity profiles and energy dissipation rates are compared with laboratory measurements and other referenced results

The transformation of Spirals into S0 galaxies in the cluster environment

We discuss the observational evidences of the morphological transformation of Spirals into S0 galaxies in the cluster environment exploiting two big databases of galaxy clusters: WINGS (0.04 < z < 0.07) and EDisCS (0.4 < z < 0.8). The most important results are: 1) the average number of S0 galaxies in clusters is almost a factor of $\sim 3 - 4$ larger today than at redshift $z \sim 1$; 2) the fraction of S0's to Spirals increases on average by a factor $\sim$ 2 every Gyr; 3) the average rate of transformation for Spirals (not considering the infall of new galaxies from the cosmic web) is: $\sim$ 5 Sp into S0's per Gyr and $\sim$ 2 Sp into E's per Gyr; 4) there are evidences that the interstellar gas of Spirals is stripped by an hot intergalactic medium; 5) there are also indirect hints that major/minor merging events have played a role in the transformation of Spiral galaxies. In particular, we show that: 1) the ratio between the number of S0's and Spirals (NS0/NSp) in the WINGS clusters is correlated with their X-ray luminosity $L_X$ ; 2) that the brightest and massive S0's are always close to the cluster center; 3) that the mean Sersic index of S0's is always larger than that of Spirals (and lower than E's) for galaxy stellar masses above $10^9.5$ Msun; 4) that the number of E's in clusters cannot be constant; 5) that the largest difference between the mean mass of S0's and E's with respect to Spirals is observed in clusters with low velocity dispersion. Finally, by comparing the properties of the various morphological types for galaxies in clusters and in the field, we find that the most significant effect of the environment is the stripping of the outer galaxy regions, resulting in a systematic difference in effective radius and Sersic index.Comment: 38 pages, 20 figure

Validation of Instantaneous Velocities Measurements with ADV Equipment in Turbulent High Two-Phase Flows

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv