1,133 research outputs found

    Chemtrails impact on the environment and human brains

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    Humans have undeniably affected the atmosphere and air quality of our planet. However, because most gasses are invisible to the human eye, it can be hard to physically see some of the changes we've brought about. Smog, exhaust from cars and trucks and smoke from chimneys and fires are a few of the visible signs, but one of the most intriguing visual manifestation of how we've changed the atmosphere are the jet trails left behind by airplanes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3086

    Modeling the Field Emission Current Fluctuation in Carbon Nanotube Thin Films

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    Owing to their distinct properties, carbon nanotubes (CNTs) have emerged as promising candidate for field emission devices. It has been found experimentally that the results related to the field emission performance show variability. The design of an efficient field emitting device requires the analysis of the variabilities with a systematic and multiphysics based modeling approach. In this paper, we develop a model of randomly oriented CNTs in a thin film by coupling the field emission phenomena, the electron-phonon transport and the mechanics of single isolated CNT. A computational scheme is developed by which the states of CNTs are updated in time incremental manner. The device current is calculated by using Fowler-Nordheim equation for field emission to study the performance at the device scale.Comment: 4 pages, 5 figure

    Methodological approaches to patent research in the field of biomedical sciences.

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    Patent research in the field of biomedical sciences (BMS) allows to give an objective assessment of the novelty and technical and economic level of the developed object of economic activity, to identify the most promising objects of economic activity, to identify competitive trends in the analyzed industry, to use the best achievements of world science, in the course of scientific research (SR), timely protect own technological and technological solutions with patents in Ukraine and abroad. The purpose of the article is to optimize methodological approaches to conducting patent research in the field of biomedical sciences on the basis of analysis of patent and scientific and technical databases. The fulfillment of the patent researches requires the use of compulsory methodological approaches, which are developed on the basis of DSTU 3575-97 "Patent Research: Key Provisions and Procedure". At each stage of the implementation of the SR, the algorithm for the patent researches, which must be followed in order to ensure the perspective of the development of object of economic activity, its legal protection, and competitiveness has been developed. The methodical approaches to conducting the patent researches in the field of BMS are determined on the basis of analysis of patent and scientific and technical databases, which allow to reveal competitive directions in the field of BMS, identify the most promising ones, give an objective assessment of novelty and technical and economic efficiency of SR; to use the most outstanding achievements of the world science during SR; timely protect own technical and technological decisions by patents in Ukraine and abroad

    Oscillation of solar radio emission at coronal acoustic cut-off frequency

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    Recent SECCHI COR2 observations on board STEREO-A spacecraft have detected density structures at a distance of 2.5--15~R propagating with periodicity of about 90~minutes. The observations show that the density structures probably formed in the lower corona. We used the large Ukrainian radio telescope URAN-2 to observe type IV radio bursts in the frequency range of 8--32~MHz during the time interval of 08:15--11:00~UT on August 1, 2011. Radio emission in this frequency range originated at the distance of 1.5--2.5 R according to the Baumbach-Allen density model of the solar corona. Morlet wavelet analysis showed the periodicity of 80~min in radio emission intensity at all frequencies, which demonstrates that there are quasi-periodic variations of coronal density at all heights. The observed periodicity corresponds to the acoustic cut-off frequency of stratified corona at a temperature of 1~MK. We suggest that continuous perturbations of the coronal base in the form of jets/explosive events generate acoustic pulses, which propagate upwards and leave the wake behind oscillating at the coronal cut-off frequency. This wake may transform into recurrent shocks due to the density decrease with height, which leads to the observed periodicity in the radio emission. The recurrent shocks may trigger quasi-periodic magnetic reconnection in helmet streamers, where the opposite field lines merge and consequently may generate periodic density structures observed in the solar wind.Comment: 10 pages, 6 figures, accepted in A&

    Model based methodology development for energy recovery in ash heat exchange systems

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    Flash tank evaporation combined with a condensing heat exchanger can be used when heat exchange is required between two streams and where at least one of these streams is difficult to handle (in terms of solid particles content, viscosity, pH, consistency etc.). To increase the efficiency of heat exchange, a cascade of these units in series can be used. Heat transfer relationships in such a cascade are very complex due to their interconnectivity, thus the impact of any changes proposed is difficult to predict. In this report, a mathematical model of a single unit ash tank evaporator combined with a condensing heat exchanger unit is proposed. This model is then developed for a chain of the units. The purpose of this model is to allow an accurate evaluation of the effect and result of an alteration to the system. The resulting model is applied to the RUSAL Aughinish Alumina digester area

    Message-Passing Methods for Complex Contagions

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    Message-passing methods provide a powerful approach for calculating the expected size of cascades either on random networks (e.g., drawn from a configuration-model ensemble or its generalizations) asymptotically as the number NN of nodes becomes infinite or on specific finite-size networks. We review the message-passing approach and show how to derive it for configuration-model networks using the methods of (Dhar et al., 1997) and (Gleeson, 2008). Using this approach, we explain for such networks how to determine an analytical expression for a "cascade condition", which determines whether a global cascade will occur. We extend this approach to the message-passing methods for specific finite-size networks (Shrestha and Moore, 2014; Lokhov et al., 2015), and we derive a generalized cascade condition. Throughout this chapter, we illustrate these ideas using the Watts threshold model.Comment: 14 pages, 3 figure

    Radio seismology of the outer solar corona

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    Observed oscillations of coronal loops in EUV lines have been successfully used to estimate plasma parameters in the inner corona (< 0.2 R_0, where R_0 is the solar radius). However, coronal seismology in EUV lines fails for higher altitudes because of rapid decrease in line intensity. We aim to use radio observations to estimate the plasma parameters of the outer solar corona (> 0.2 R_0). We use the large Ukrainian radio telescope URAN-2 to observe type IV radio burst at the frequency range of 8-32 MHz during the time interval of 09:50-12:30 UT in April 14, 2011. The burst was connected to C2.3 flare, which occurred in AR 11190 during 09:38-09:49 UT. The dynamic spectrum of radio emission shows clear quasi-periodic variations in the emission intensity at almost all frequencies. Wavelet analysis at four different frequencies (29 MHz, 25 MHz, 22 MHz and 14 MHz) shows the quasi-periodic variation of emission intensity with periods of 34 min and 23 min. The periodic variations can be explained by the first and second harmonics of vertical kink oscillation of transequatorial coronal loops, which were excited by the same flare. The apex of transequatorial loops may reach up to 1.2 R_0 altitude. We derive and solve the dispersion relation of trapped MHD oscillations in a longitudinally inhomogeneous magnetic slab. The analysis shows that a thin (with width to length ratio of 0.1), dense (with the ratio of internal and external densities of > 20) magnetic slab with weak longitudinal inhomogeneity may trap the observed oscillations. Seismologically estimated Alfv\'en speed inside the loop at the height of 1 R_0 is 1000 km/s. Then the magnetic field strength at this height is estimated as 0.9 G. Extrapolation of magnetic field strength to the inner corona gives 10 G at the height of 0.1 R_0.Comment: 12 pages, 10 figures, Accepted in A&
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