457 research outputs found
Calculating the exhaust ejection system in the ventilation of the painting chamber
Problem statement: The ventilation system plays a decisive role in the creation of the microclimate in various premises. It is known that the ejection ventilation system is well proven both for high-rise residential and office buildings, and for industrial premises. All paint coatings are corrosive and easily flammable substances. In addition, solvent vapors are explosive. It is therefore desirable to use ejection ventilation system in the design of the ventilation system of paint booths. The ejector is simple in design; it can work in a wide range of parameters of state of steam-air mixtures.Results: The calculation and design of a low-pressure ejector have been performed. An ejection ventilation system has been synthesized using the universal modeling package ChemCad that contains highly developed database to calculate thermophysical properties of various substances and their mixtures.Conclusions: The obtained results can be recommended in the layout of the ventilation gadget of paint booths both new and reconstructed. The Usage of the software allows carrying out multiple calculations, which are indispensable for the solution of optimization problems
Depression is not the only cause of cognitive impairment in chronic migraine
Background. Patients with the chronic migraine frequently present with memory and attention complaints. However, the prevalence and phenotype of such impairment in chronic migraine have not been studied.Objective – to evaluate the prevalence of the objective cognitive deficit in patients with chronic migraine and factors underlying its etiology. Materials and methods. We recruited 62 subjects with chronic migraine and 36 genderand age-matched controls with low-frequency episodic migraine (not more, then 4 headache days per month) aged 18–59. All patients filled in the Hospital Anxiety and Depression Scale (HADS) and Sheehan Disability Scale. Cognitive function was assessed with the Montreal Cognitive Assessment (MoCA), Digital Symbol Substitution Test (DSST), Rey Auditory Verbal Learning Test (RAVLT), and the Perceived Deficits Questionnaire (PDQ-20).Results. In this study 58 % of patients with chronic migraine complained of memory loss. Cognitive impairment was also found with PDQ-20. Objectively, we found a significant decrease in 90-second DSST results and RAVLT total recall and learning rate. In 40 % of subjects with chronic migraine scored lower than 26 points on MoCA. Patients with chronic migraine more frequently had lower DSST rates as compared to episodic migraine (odds ratio 5.07 (95 % confidence interval – 1.59–16.17); p = 0.003). Depression and anxiety did not correlate with performance on cognitive tests. Chronic migraine (frequent headache) and longer headache history, but not depression, anxiety or medication overuse were independent predictors of cognitive impairment.Conclusion. Subjective and objective cognitive deficits are prevalent in the chronic migraine population. Most often memory and attention are impaired. Longer headache history and presence of chronic migraine are independent risk factors for cognitive impairment in patients with chronic migraine
Signal recognition and background suppression by matched filters and neural networks for Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is a digital antenna array, which
measures the radio emission of the cosmic-ray air-showers in the frequency band
of 30-80 MHz. Tunka-Rex is co-located with TAIGA experiment in Siberia and
consists of 63 antennas, 57 of them are in a densely instrumented area of about
1 km\textsuperscript{2}. In the present work we discuss the improvements of the
signal reconstruction applied for the Tunka-Rex. At the first stage we
implemented matched filtering using averaged signals as template. The
simulation study has shown that matched filtering allows one to decrease the
threshold of signal detection and increase its purity. However, the maximum
performance of matched filtering is achievable only in case of white noise,
while in reality the noise is not fully random due to different reasons. To
recognize hidden features of the noise and treat them, we decided to use
convolutional neural network with autoencoder architecture. Taking the recorded
trace as an input, the autoencoder returns denoised trace, i.e. removes all
signal-unrelated amplitudes. We present the comparison between standard method
of signal reconstruction, matched filtering and autoencoder, and discuss the
prospects of application of neural networks for lowering the threshold of
digital antenna arrays for cosmic-ray detection.Comment: ARENA2018 proceeding
Current Status and New Challenges of The Tunka Radio Extension
The Tunka Radio Extension (Tunka-Rex) is an antenna array spread over an area
of about 1~km. The array is placed at the Tunka Advanced Instrument for
cosmic rays and Gamma Astronomy (TAIGA) and detects the radio emission of air
showers in the band of 30 to 80~MHz. During the last years it was shown that a
sparse array such as Tunka-Rex is capable of reconstructing the parameters of
the primary particle as accurate as the modern instruments. Based on these
results we continue developing our data analysis. Our next goal is the
reconstruction of cosmic-ray energy spectrum observed only by a radio
instrument. Taking a step towards it, we develop a model of aperture of our
instrument and test it against hybrid TAIGA observations and Monte-Carlo
simulations. In the present work we give an overview of the current status and
results for the last five years of operation of Tunka-Rex and discuss prospects
of the cosmic-ray energy estimation with sparse radio arrays.Comment: Proceedings of E+CRS 201
First analysis of inclined air showers detected by Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is a digital antenna array for the
detection of radio emission from cosmic-ray air showers in the frequency band
of 30 to 80 MHz and for primary energies above 100 PeV. The standard analysis
of Tunka-Rex includes events with zenith angle of up to 50. This cut is
determined by the efficiency of the external trigger. However, due to the
air-shower footprint increasing with zenith angle and due to the more efficient
generation of radio emission (the magnetic field in the Tunka valley is almost
vertical), there are a number of ultra-high-energy inclined events detected by
Tunka-Rex. In this work we present a first analysis of a subset of inclined
events detected by Tunka-Rex. We estimate the energies of the selected events
and test the efficiency of Tunka-Rex antennas for detection of inclined air
showers.Comment: ARENA2018 proceeding
Improved measurements of the energy and shower maximum of cosmic rays with Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is an array of 63 antennas located in
the Tunka Valley, Siberia. It detects radio pulses in the 30-80 MHz band
produced during the air-shower development. As shown by Tunka-Rex, a sparse
radio array with about 200 m spacing is able to reconstruct the energy and the
depth of the shower maximum with satisfactory precision using simple methods
based on parameters of the lateral distribution of amplitudes. The LOFAR
experiment has shown that a sophisticated treatment of all individually
measured amplitudes of a dense antenna array can make the precision comparable
with the resolution of existing optical techniques. We develop these ideas
further and present a method based on the treatment of time series of measured
signals, i.e. each antenna station provides several points (trace) instead of a
single one (amplitude or power). We use the measured shower axis and energy as
input for CoREAS simulations: for each measured event we simulate a set of
air-showers with proton, helium, nitrogen and iron as primary particle (each
primary is simulated about ten times to cover fluctuations in the shower
maximum due to the first interaction). Simulated radio pulses are processed
with the Tunka-Rex detector response and convoluted with the measured signals.
A likelihood fit determines how well the simulated event fits to the measured
one. The positions of the shower maxima are defined from the distribution of
chi-square values of these fits. When using this improved method instead of the
standard one, firstly, the shower maximum of more events can be reconstructed,
secondly, the resolution is increased. The performance of the method is
demonstrated on the data acquired by the Tunka-Rex detector in 2012-2014.Comment: Proceedings of the 35th ICRC 2017, Busan, Kore
Социальная ответственность: трансформация исследовательских подходов в контексте “общества риска”
The notion of social responsibility which is sufficiently detailed elaborate by modern social science is applied nowadays increasingly frequently as long as it is characterize various aspects and spheres of social life. Renewed interest in the concept today is connected with sociologist’s attempts to interpret current social situation - the condition of postmodernity described by uncertainty and risk which are escalated by global economic crisis. Vital need to conceptualize social responsibility under such conditions is appeared in a new context shaped by risk society. Evolution of social responsibility concept from classical - settled in modernity - to perceptions relevant to risk society is traced back in the article.Понятие социальной ответственности, достаточно подробно разработанное современной социальной наукой, сегодня применяется все чаще, поскольку характеризует разнообразные стороны и сферы социальной жизни. Актуализация интереса к данному понятию сегодня связана с попытками социологов осмыслить сложившуюся социальную ситуацию - состояние постсовременности, характеризующееся неопределенностью и риском, обострившимися в связи с мировым экономическим кризисом. В таких условиях появляется насущная необходимость концептуализации социальной ответственности в новом контексте, сформированном обществом риска. В статье прослеживается эволюция понятия социальной ответственности от классических - установившихся в эпоху модерна - к адекватным обществу риска представлениям
Online Board as a Means of Teaching Reading During the Implementation of Blended English Learning
В современных реалиях многие исследователи заинтересованы в детальном исследовании процесса обучения иностранному языку учащихся средней школы. В настоящее время данная тема приобретает особенное значение в связи с повышением качества языковой подготовки. В современной системе образования наблюдается тенденция перехода от обычных способов обучения к современным информационным технологиям.In modern realities, many researchers are interested in a detailed study of the process of teaching a foreign language to secondary school students. Currently, this topic is of particular importance in connection with the improvement of the quality of language training. In the modern education system, there is a tendency to move from conventional methods of education to modern information technologies
Tunka-Rex: energy reconstruction with a single antenna station (ARENA 2016)
The Tunka-Radio extension (Tunka-Rex) is a radio detector for air showers in
Siberia. From 2012 to 2014, Tunka-Rex operated exclusively together with its
host experiment, the air-Cherenkov array Tunka-133, which provided trigger,
data acquisition, and an independent air-shower reconstruction. It was shown
that the air-shower energy can be reconstructed by Tunka-Rex with a precision
of 15\% for events with signal in at least 3 antennas, using the radio
amplitude at a distance of 120\,m from the shower axis as an energy estimator.
Using the reconstruction from the host experiment Tunka-133 for the air-shower
geometry (shower core and direction), the energy estimator can in principle
already be obtained with measurements from a single antenna, close to the
reference distance. We present a method for event selection and energy
reconstruction, requiring only one antenna, and achieving a precision of about
20\%. This method increases the effective detector area and lowers thresholds
for zenith angle and energy, resulting in three times more events than in the
standard reconstruction
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