1,133 research outputs found
Chemtrails impact on the environment and human brains
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
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.
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
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
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
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 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
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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