Monitoring and prediction of natural disasters

The problems of natural disaster predicting and accomplishing a synthesis of environmental monitoring systems to collect, store, and process relevant information for their solution are analyzed. A three-level methodology is proposed for making decisions concerning the natural disaster dynamics. The methodology is based on the assessment of environmental indicators and the use of numerical models of the environment

Some New Reactions and Properties of Xanthane Hydride (5-Amino-1,2,4-dithiazole-3-thione)

Aminomethylation of xanthane hydride (5-amino-1,2,4-dithiazole-3-thione) with the RNH2–HCHO system has resulted in the formation of the derivatives of new heterocyclic system (3,7-dihydro-5H-[1,2,4]-dithiazolo[4,3-a][1,3,5]triazine) in low yields. The reaction of xanthane hydride with dicyandiamide has led to thioammeline [4,6-diamino-1,3,5-triazine-2(5Н)-thione]. Some practically important properties of xanthane hydride and its derivatives have been investigated. Xanthane hydride has efficiently exhibited carbon steel corrosion in neutral aqueous media. The prepared compounds have not exhibited growth-regulating or antidote activity to herbicide 2,4-D

"Head-to-head" and "tail-to-tail" 180-degree domain walls in an isolated ferroelectric

"Head-to-head" and "tail-to-tail" 180-degree domain-walls in a finite isolated ferroelectric sample are theoretically studied using Landau theory. The full set of equations, suitable for numerical calculations is developed. The explicit expressions for the polarization profile across the walls are derived for several limiting cases and wall-widths are estimated. It is shown analytically that different regimes of screening and different dependences for width of charged domain walls on the temperature and parameters of the system are possible, depending on spontaneous polarization and concentration of carriers in the material. It is shown that the half-width of charged domain walls in typical perovskites is about the nonlinear Thomas-Fermi screening-length and about one order of magnitude larger than the half-width of neutral domain-walls. The formation energies of "head-to-head" walls under different regimes of screening are obtained, neglecting the poling ability of the surface. It is shown that either "head-to-head" or "tail-to-tail" configuration can be energetically favorable in comparison with the monodomain state of the ferroelectric if the poling ability of the surface is large enough. If this is not the case, the existence of charged domain walls in bulk ferroelectrics is merely a result of the domain-growth kinetics. Size-effect corresponding to the competition between state with charged domain wall, single domain state, multidomain state, and the state with the zero polarization is considered. The results obtained for the case of an isolated ferroelectric sample were compared with the results for an electroded sample. It was shown that charged domain wall in electroded sample can be either metastable or stable, depends on the work function difference between electrodes and ferroelectric and the poling ability of the electrode/ferroelectric interface.Comment: 47 pages, 10 figure

On the effects of aviation on carbon-methane cycles and climate change during the period 2015-2100

The effects of aviation on the Earth's atmosphere are mainly focused on greenhouse gases emissions, since CO2 and CH4 emissions are an important part of climate change contribution. The purpose of this paper is to discuss and evaluate this contribution using a coupled model of global CO2 and CH4 cycles, taking into account the maximum number of reservoirs and fluxes of these gases. According to this approach, a method based on a simple climate model and a simulation model of global CO2 and CH4 cycles is proposed, as a tool to determine the aviation's role in climate change. This coupled model consists of eight separate blocks that perform specific functions to evaluate the impacts of aviation emissions on climate change in a series of scenarios. The proposed method can calculate the global temperature change in various scenarios by processing the available data in the current literature. Based on these data it has been shown that global temperature and CO2 concentration in the atmosphere can increase by 1–3 °C and up to 570–750 ppm, respectively, depending on the anthropogenic scenario. The global temperature forecast is obtained with an average error of 3.4%.The results of this study show that the aviation's contribution to these changes during 2015–2100 is1.5 ± 0.1%. © 202