Monte Carlo simulations of two-component coulomb gases applied in surface electrodes

In this work, we study the gapped Surface Electrode (SE), a planar system composed of two-conductor flat regions at different potentials with a gap G between both sheets. The computation of the electric field and the surface charge density requires solving Laplace’s equation subjected to Dirichlet conditions (on the electrodes) and Neumann Boundary Conditions over the gap. In this document, the GSE is modeled as a Two-Dimensional Classical Coulomb Gas having punctual charges +q and −q on the inner and outer electrodes, respectively, interacting with an inverse power law 1~r-potential. The coupling parameter Γ between particles inversely depends on temperature and is proportional to q2. Precisely, the density charge arises from the equilibrium states via Monte Carlo (MC) simulations. We focus on the coupling and the gap geometry effect. Mainly on the distribution of particles in the circular and the harmonically-deformed gapped SE. MC simulations differ from electrostatics in the strong coupling regime. The electrostatic approximation and the MC simulations agree in the weak coupling regime where the system behaves as two interacting ionic fluids. That means that temperature is crucial in finite-size versions of the gapped SE where the density charge cannot be assumed fully continuous as the coupling among particles increases. Numerical comparisons are addressed against analytical descriptions based on an electric vector potential approach, finding good agreement.

Statistical Modelling of the Fatigue Bending Strength of Norway Spruce Wood

When wood is used as a structural material, the fact that it is a highly inhomogeneous material, which significantly affects its static and fatigue properties, presents a major challenge to engineers. In this paper, a novel approach to modelling the fatigue-life properties of wood is presented. In the model, the common inverse-power-law relationship between the structural amplitude loads and the corresponding number of load cycles to failure is augmented with the influence of the wood’s mass density, the loading direction and the processing lot. The model is based on the two-parametric conditional Weibull’s probability density function with a constant shape parameter and a scale parameter that is a function of the previously mentioned parameters. The proposed approach was validated using the example of experimental static and fatigue-strength data from spruce beams. It turned out that the newly presented model is capable of adequately replicating the spruce’s S-N curves with a scatter, despite the relatively scarce amount of experimental data, which came from different production lots that were loaded in different directions and had a significant variation in density. Based on the experimental data, the statistical model predicts that the lower density wood has better fatigue strength.

Universal spectrum for short period (days) variability in atmospheric total ozone

Long-range spatio-temporal correlations manifested as the self-similar fractal geometry to the spatial pattern concomitant with inverse power law form for the power spectrum of temporal fluctuations are ubiquitous to real world dynamical systems and are recently identified as signatures of self-organized criticality Self-organised criticality in atmospheric flows is exhibited as the fractal geometry 10 the global cloud cover pattern and the inverse power law form for the atmospheric eddy energy spectrum, In this paper, a recently developed cell dynamical system model for atmospheric flows is summarized. The model predicts inverse power law form of the statistical normal distribution for atmospheric eddy energy spectrum as a natural consequence of quantum-like mechanics governing atmospheric flows extending up to stratospheric levels and above, Model Predictions are in agreement with continuous periodogram analyses of atmospheric total ozone. Atmospheric total ozone variability (in days) exhibits the temporal signature of self-organized criticality, namely, inverse power law form for the power spectrum. Further, the long-range temporal correlations implicit to self-organized criticality can be quantified in terms of the universal characteristics of the normal distribution. Therefore the total pattern of fluctuations of total ozone over a period of time is predictable.

Dynamic Compressive Strength and Fragmentation in Sedimentary and Metamorphic Rocks

Brittle deformation at high strain rates results in intense fragmentation and rock pulverisation. For rocks, the critical strain rate at which this behaviour occurs is ~10^2 s-1. The mechanical properties of rocks at these strain rates can also be very different from their quasi-static properties. Deformation of rocks at these strain rates is uncommon in nature but can occur during fault rupture, landslide events, and meteorite impacts. In this study, we present results of high strain rate mechanical tests to determine the characteristic strain rate for rate-dependent brittle failure, and the fragment size and shape distributions that result from failure at these conditions. We investigated sandstone, quartzite, limestone, and marble and considered whether the fragment characteristics can be used as diagnostic indicators of loading conditions during brittle failure. We find that the characteristic strain rates, where the dynamic strength is twice the quasi-static strength, range between ~150 and 300 s-1 for rate-dependent brittle failure in the investigated lithologies. Furthermore, we use our results to demonstrate an empirical inverse power-law relationship between fragment size and strain rate for dynamic failure under uniaxial compression. On the other hand, we show that fragment shape is independent of strain rate under dynamic uniaxial loading.

Spillway preheating

In traditional models only an order one fraction of energy is transferred from the inflaton to radiation through nonperturbative resonance production in preheating immediately after inflation, due to backreaction effects. We propose a particle production mechanism that could improve the depletion of the inflaton energy density by up to four orders of magnitude. The improvement comes from the fast perturbative decays of resonantly produced daughter particles. They act as a “spillway” to drain these daughter particles, reducing their backreaction on the inflaton and keeping the resonant production effective for a longer period. Thus we dub the scenario “spillway preheating”. We also show that the fraction of energy density remaining in the inflaton has a simple inverse power-law scaling in the scenario. In general, spillway preheating is a much more efficient energy dissipation mechanism, which may have other applications in model building for particle physics.

MODERNIZATION OF ELEMENTS OF STRIP-TILL TECHNOLOGY UNDER A SUNFLOWER IN THE CENTRAL PRECAUCASIA ZONE

The need to introduce new progressive technologies for sunflower cultivation in Stavropol Territory is based on an analysis of trends in the development of arable land for this crop over the last ten-year period from 2010 to 2020. A significant annual increase in the areas under sunflower in the arid zone by an average of 3.9 thousand hectares and a tendency for this indicator to increase in zones of unstable and sufficient moisture by 0.55 and 1.0 thousand hectares have been established. The purpose of the research is to evaluate the effectiveness of the modernized soil cultivation system in the Strip-till technology for sunflower in the unstable moisture zone of the Stavropol Territory on the southern chernozem, poorly humified in comparison with the traditionally adopted cultivation system. A distinctive feature of the new strip-till soil cultivation system is continuous disc stubble cultivation with the Catros harrow 8 - 10 cm instead of leaving untreated stubble strips. In the process of research, using the method of the theory of dimensions, an inverse power-law dependence was derived, showing that the smaller the weighted average diameter of the aggregates D, the higher the soil density P, taking into account the correction factor C for a certain type of soil. It was found that under relatively favorable moisture conditions in 2019 and in the dry season of 2020, spring moisture accumulation under strip-till was higher than under traditional ones by 12 and 8 mm, respectively. Cultivation of sunflower, with preliminary disc processing of stubble and the formation of strips with slots for sowing crops, following the Strip-till technology, is more effective in comparison with the traditionally adopted technology in the southeast of the Stavropol Territory, since an average increase in sunflower yields over the years by 0.20 t/ha with a higher profitability of 31%