bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmission of optical vortices through Bragg optical multihelicoidal fibers of heterogeneous type
Authors: Lapin B , Yavorsky M , Barshak E , Vikulin D , Alexeyev C
Published: November 2019

In this paper we have theoretically shown that two-part and three-part multihelicoidal fibers of heterogeneous type in the presence of twist defects are able to invert the topological charge of incoming optical vortices. We have shown that three-part multihelicoidal fibers of that type can be used as compact comb filters for optical vortices. Also we have studied the emergence of topologically charged fields localized near defects in such fibers. We have established that strongly localized fields can emerge only in three-part multihelicoidal fibers.
Testing of diffractive optical element as part of specific CO2 laser equipment for metallic materials modification
Authors: Murzin S P , Kazanskiy N L , Liedl G , Humenberger G
Published: November 2019

Testing of a reflective diffractive optical element (DOE) as part of specific CO2 laser equipment Oerlikon OPL 2000 for metallic materials modification was performed. The power density distribution in a plane located behind the DOE focal plane has been measured. It was found that DOEs make it possible to form a predetermined beam power density profile and to perform the transformation of laser energy, chosen by calculation previously. The use of these optical elements in the laser material treatment reveals new possibilities for controlling properties and operational characteristics of processed components. Additional redistribution of the beam power to edges of the laser spot is achieved by increasing the proportion of energy reflected by DOE peripheral zones, for example, by increasing the aperture of the focusable beam. It is proposed using a telescopic system of two lenses to change the aperture of the laser beam focusable by the DOE.
Analysis of the possibility of upscaling based on apodization for partially coherent optical systems in the presence of aberrations
Authors: Skidanov Y R
Published: November 2019

The degree of coherence of radiation is an important characteristic on which the interference properties of light fields and, as a consequence, the resolution of optical systems depend. When propagating over long distances even in free space, initially completely coherent or incoherent radiation becomes partially coherent. This fact should be taken into account in the formation of optical images along with the influence of wave front aberrations. In this paper, we investigate the change in the resolution of the system for two near-point light sources depending on the degree of spatial coherence in the presence of different aberrations. The possibility of improving the resolution in the considered situations on the basis of the amplitude apodization of the optical system is also investigated.
Modeling the process of optical characteristics variation for a solar sail surface during heliocentric flights
Authors: Starinova O L , Rozhkov M A , Alipova B , Chernyakina I V
Published: November 2019

In this paper authors consider changing of optical characteristics of the solar sail surface during the heliocentric flight. The sail surface is a multilayer epitaxial structure, which is physically a polyamide film covered with different metals on the front and back sides. We calculate the optical characteristics of the multilayer film using the transition matrix method adapted for quantum-sized layers and taking into account the solar radiation spectrum. In order to analyse the influence of these characteristics variation on the spacecraft motion due to sail degradation we simulate the heliocentric Earth-Mercury flight.
Hyperspectral monitoring AOTF-based apparatus
Authors: Pozhar V , Gaponov M , Machikhin A , Shirokov S
Published: November 2019

The apparatus for hyperspectral imaging in visible range is described. The rugged and compact design makes it suitable for unmanned aerial vehicles. The system is capable both for recording the entire spectral-spatial data (“hypercube”) and for selective grabbing the spectral images at characteristic wavelengths. This selective mode provides real-time extracting the most valuable information from the monitoring scene and reduces requirements for operation speed and data storage capacity of processing subsystem. The technical characteristics and basic features of the hyperspectral apparatus are presented and discussed.
Modelling and record technologies of address fibre Bragg structures based on two identical ultra-narrow gratings with different central wavelengths
Authors: Morozov O G , Sakhabutdinov A Zh , Nureev I I , Misbakhov R Sh
Published: November 2019

Address fiber Bragg structures (AFBS) make it possible to effectively solve the problem of sensors interrogation and multiplexing in multi-sensor networks with microwave photonic processing of information. Based on the method of inverse Fourier transform, a mathematical model of the optical fiber refractive index profile was constructed to form 2λ-FBG AFBS with two FBG with identical spectral responses at separated wavelengths. As the initial parameters for the construction of the mathematical model, the desired spectral profile of 2λ-FBG AFBS was specified, including the reflection coefficient and the width of the transmission band of its two identical ultra-narrow-band gratings and the separation between them. On the basis of the study of the mathematical model, the possibility of selecting the necessary values of the refractive index and the laws of its modulation is shown, allowing the spectral profile of 2λ-FBG AFBS to be formed so that they can be used as a sensitive element, transforming information from optical range to radiofrequency one. The analysis of the formation and recording methods for 2λ-FBG AFBS was carried out. To implement given structures, the technology, using of an ultraviolet argon laser, the classic phase masks with sequential recording of several arrays with precise movement and strain of the fiber were chosen. Further paper deals with issues of interrogation of the developed structures and principles of measurement system construction on their basis.
Synthesis of conductive films based on oxidized carbon nanotubes
Authors: Gorshkov M V , Moskalenko A S
Published: November 2019

This talk presents the work related to creation of films based on carbon nanotubes (CNT). CNT films have a great significance in chemistry world because of possibility of obtaining very strong, conductive and flexible films based on special CNT properties. These films also can be very useful in optical applications, for example, as sensing element of IR and THz optical sensors. But achievement of a cheap and strong film still remains a difficult task because of inert CNT structure. In this paper singlewalled and multiwalled carbon nanotubes were used. The film was formed by using oxidation, filtration and annealing processes. This technology can be the cheapest because of small quantity of chemicals and needs to be investigated. The film demonstrates high temperature resistivity without deformation.
Features of optical signals processing for monitoring the state of the flowing liquid medium with a refractometer
Authors: Grebenikova N M , Davydov V V , Smirnov K J
Published: November 2019

The article discusses the method of monitoring the state of flowing complex liquid media based on the phenomenon of refraction. A criterion has been defined by which the liquid medium to be measured using refraction is complex. The features of processing optical signals obtained using a refractometer from complex liquid media are considered. The results of experimental studies are presented. A comparison of the results of the experiment and the calculation is presented.
Colorization of copper surfaces by nanostructure modifications with ultrashort laser pulses
Authors: Murzin S P , Liedl G , Pospichal R
Published: November 2019

A colorization of copper surfaces after nanostructure modifications with ultrashort laser pulses was studied. Femtosecond laser has been used for experiments. A relative motion of the laser beam on the material was realized. Tracks on the material obtained in a multi-pulse mode with an energy density lower than the threshold ablation were studied using scanning electron microscopy and atomic force microscopy. By the surface treatment with a laser pulses duration smaller than 30 fs, almost-wavelength periodic structures were formed and finally the surface brightness was increased. It was demonstrated that small nanostructure modifications changed the surface colour significantly. Using backscattered and secondary electron modes of scanning electron microscopy images were obtained from four sample regions that showed different colours, such as dark purple-red, turquoise, yellow-orange and grey-green. It was found that one of the main reasons for the difference in colour of images is the oxidation degree.
Features of adaptive phase correction of optical wave distortion under conditions of intensity fluctuations
Authors: Botygina N N , Emaleev O N , Lavrinov V V , Lukin V P , Selin A A , Soin E L
Published: November 2019

For the first time the reason of loss of efficiency of adaptive phase correction at propagation of optical waves in turbulent atmosphere under conditions of strong intensity fluctuations is experimentally explained. According to the data of experiments performed both on horizontal and vertical atmospheric routes, it was found that when the radius of coherence in the optical wave becomes less than the first Fresnel zone, intensity fluctuations begin to affect the data of phase measurements. This results in the fact that the main meter of the adaptive optics (AO) system - Hartmann’s sensor - in the presence of deep amplitude modulation no longer provides the correctness of phase distribution measurements. Based on the study of the behavior of the modal components of the phase fluctuations reconstructed from the measurement data at different operating modes, it was found that, first of all, the lower modes of phase fluctuations decomposition - tilts, defocusing and astigmatism - are distorted and, as the analysis of these modes shows, they differ greatly from the classical modes corresponding to the mode of weak fluctuations.
The influence of the aperture diaphragm on the size of the subjective speckles and the application of this in speckle photography
Authors: Osipov M N , Sergeev R N
Published: November 2019

The paper presents the results of a study showing the possibility of reducing the size of speckles to increase the sensitivity and accuracy of the measuring system based at the use of methods of speckle photography and speckle interferometry. The theoretical and experimental results the average size of speckles formed in the double-exposure specklegram depends on the aperture diaphragms of the optical system – circular aperture, annular aperture, square aperture and frame aperture – are presented. The experimental results forming of the diffraction halo and the Young’s fringes for a circular, annular, square and frame apertures are presented.
Method of assessment the degree of reliability of the pulse wave image in the rapid diagnosis of the human condition
Authors: Grevtseva A S , Smirnov K J , Greshnevikov K V , Davydov V V , Rud’ V Yu , Glinushkin A P
Published: November 2019

In the article a methods of results reliability increasing during diagnosing a person’s condition by pulse oximeter are considered. A new method of estimating the reliability of the measurement results of the parameters of the pulse wave and the method of tuning the optical part of the pulse oximeter are proposed. The use of this technique allows to make the insignificant of number errors influence on the measurements results. The experimental data about the various people condition research are presented.
Regulations for the editors of journal “Computer Optics”
Authors: Kudryashov D V , Kirsh D V
Published: November 2019

The authors analyze the process of passing an article from the moment it is received by the editors to publication in the scientific journal Computer Optics, which has three main sections: 1) diffractive optics, optical information technologies; 2) image processing, pattern recognition; 3) numerical methods and data analysis. It is noted that due to the effective organization and precise regulation of the editorial and publishing process, the journal has gained credibility, being indexed in the international scientometric databases Scopus and Web of Science (ESCI).
RAS Academician Vladimir P. Shorin and diffractive computer optics
Authors: Sokolov V O
Published: November 2019

The paper briefly describes the main achievements in the area of laser technologies and the application of diffractive computer optics of Academician of the Russian Academy of Sciences, Doctor of technical sciences, Professor, Honoured Scientist and Engineer of the RSFSR, Laureate of the State Award of the Russian Federation in the area of science and technology Vladimir P. Shorin.
The 75th anniversary of professor Grigory Isaevich Greisukh
Authors: Danilov V A , Odinokov S B
Published: November 2019

The article briefly describes scientific, pedagogical and organizational achievements of professor Greisukh Grigory Isaevich, Doctor of Engineering Science.
Application of superpixel segmentation and morphological projector for structural changes detection in remote sensing images
Authors: Denisova A Y , Egorova A A , Sergeyev V V
Published: November 2019

Detection of structural changes in images is one of the important tasks of remote sensing (RS) data thematic analysis. The effective way to solve it is applying the Pyt'ev’s morphological projector to the pair of images of the same scene acquired on different dates. The main advantage of this method is its invariance to global brightness transformations, which in the case of RS images correspond to different parameters of the atmosphere or the different values of the brightness-contrast ratio of the scene. However, the classical Pyt'ev’s morphological projector and its regularized versions do not take into account the spatial connectivity of image samples. As a result, they ignore the textural features of images. In this article, we suggest the algorithm of structural changes detection based on superpixel segmentation and Pyt'ev’s morphological projector that takes into account local characteristics of the image pixels. In the experimental research, we analyzed the accuracies of the proposed and classical Pyt'ev’s structural change detection methods using simulated and real RS images. The comparison of two algorithms showed that the proposed method is more robust to the additive white Gaussian noise (AWGN) at different values of signal-to-noise (SNR) ratio. Additionally, the experiments with nonlinear brightness distortions (vignetting) of one of the pair of images demonstrated that the proposed method has lower false positive rates than the classical one.
Detection and identification of objects on multispectral satellite images
Authors: Dementiev V E , Magdeev R G , Tashlinskii A G
Published: November 2019

This article considers the detection of objects on the time sequences of satellite multizone images. Optimal and quasi-optimal detection algorithms are built on the basis of a combination of non-linear double stochastic filters and pseudo-gradient procedures. The analysis of behavior of the synthesized algorithms at processing of the real satellite material under conditions of a priori uncertainty concerning parameters of deformation of the reference image is carried out.
Digital image forgery detection using deep learning approach
Authors: Kuznetsov A
Published: November 2019

This paper presents an algorithm for detecting one of the most commonly used types of digital image forgeries - splicing. The algorithm is based on the use of the VGG-16 convolutional neural network. The proposed network architecture takes image patches as input and obtains classification results for a patch: original or forgery. On the training stage we select patches from original image regions and on the borders of embedded splicing. The obtained results demonstrate high classification accuracy (97.8% accuracy for fine-tuned model and 96.4% accuracy for the zero-stage trained) for a set of images containing artificial distortions in comparison with existing solutions. Experimental research was conducted using CASIA dataset.
Nonlinear dimensionality reduction of hyperspectral data based on spectral information divergence preserving principle
Authors: Myasnikov E V
Published: November 2019

The paper proposes a nonlinear dimensionality reduction technique for hyperspectral data based on the principle of preserving the spectral information divergence (SID). In this technique, the spectral information divergence is used as a spectral dissimilarity measure in both the original and reduced space. In the experimental studies performed using open hyperspectral images, we solve the problem of per-pixel classification of hyperspectral images. The developed method extends the existing hyperspectral data analysis toolkit, which allows reducing the dimensionality of hyperspectral data based on the principle of preserving specified spectral dissimilarity measures.
Development of Technology for Remote Location of Unknown Underground Cavities and Deep-Seated Rockslides by Unmanned Air Systems (UAS)
Authors: Shopov Y , Ognianov O , Filipov A , Ivanov I R
Published: November 2019

This work aims to create new scientific knowledge by developing new innovative technology for remote detection of unknown underground cavities and deep-seated rockslides. To achieve the goal, we intend to develop new innovative technology for remote localization of unknown underground cavities and deep-seated rockslides using a thermal camera mounted on a unmanned aerial vehicle (UAV).

Technology is a defined sequence of operations and procedures under optimal conditions, varying within certain allowable limits, resulting in obtaining a particular result or product that meets certain requirements. Therefore, the development of new technology involves determining the allowable limits of deviation of the optimal conditions of operations and procedures for producing a good result that meets the established requirements. The development of new technology also involves determining the limits of its applicability under different external conditions. This paper includes determination of the allowable limits and the limits of applicability of the new technology being developed.

Until now, no technology has been developed for remote detection of unknown underground cavities or deep-seated rockslides. The goal of this work is the development of such innovative technology with numerous applications in construction, environmental studies and protection, security, defence and infrastructure.
Invariant manifold of variable stability in the Koper model
Authors: Balabaev M
Published: November 2019

The Koper model is a vector field that was developed to study electrochemical oscillations arising in diffusion processes. In the framework of this paper, we consider the Koper model of chemical reactors. It is a three-dimensional autonomous slow-fast system with a folded node and a supercritical singular Hopf bifurcation. The aim is to construct the expansion of invariant manifold with variable stability and corresponding gluing function using the flow curvature method. We show that Koper model has sufficiently smooth invariant surface, called black swan. Computer simulation and computer algebra methods are used for the quantitative analysis of the model.
Numerical simulation of the catalytic process of isomerization of pentane-hexane cut
Authors: Faskhutdinov A G , Faskhutdinova R I , Arefyev I A , Enikeeva L V
Published: November 2019

The basic schemes for the transformation of the pentane-hexane fraction catalytic isomerization, which are probable from the point of view of thermodynamics, have been considered. Based on the literary analysis of possible transformation schemes, the mechanism of the process and on the basis of experimental data, a mathematical model of the reactor block of the process was constructed and the kinetic parameters were determined. The foundations were laid for the subsequent solution of the tasks of the multi-purpose optimization of the catalytic isomerization process of the pentane-hexane fraction.
Strategy for the realization of soft docking with space debris by using a tether system
Authors: Pikalov R S
Published: November 2019

This study focuses on the dynamics of a rendezvous of a tug and large space debris connected by a viscoelastic tether. It is assumed that control is realized by changing the length of the tether. The goal is to study the dynamic of the maneuver of the rendezvous and to find the ways, which allow one to reduce the oscillation of the tether. The obtained results can be applied as applications for the tasks of implement rendezvous of two bodies using the tether.
Positioning of radio emission sources with unmanned aerial vehicles using TDOA-AOA measurement processing
Authors: Bachevsky S V , Fokin G A , Simonov A N , Sevidov V V
Published: November 2019

Positioning of radio emission sources (RES) with ground and flying network segments exploits interaction of sensors aboard Unmanned Aerial Vehicles (UAVs) with terrestrial stationary ground sensors. Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) measurements processing are the most wide-spread techniques for passive geolocation systems. Successful implementation of TDOA-AOA positioning in existing UAV based geolocation systems achieves accuracy results of tens and hundreds of meters for overoptimistic scenarios without reflections in so called Line of Sight (LOS) conditions. Prevailing application specific cases for UAV based positioning include search and rescue (S&R) operations in mountains, hills and other regions of irregular surface topography with Non-Line of Sight (NLOS) conditions, where radio waves could experience severe reflection and diffraction. For geolocation tasks NLOS problem usually leads to significant errors for both TDOA and AOA measurement processing techniques. Joint processing of TDOA and AOA primary measurements could partially overcome this problem by preliminary identification and exclusion of reflected signals. In current research we refine existing mathematical model and develop new simulation models to investigate NLOS tolerance during positioning with one stationary ground sensor and one sensor aboard flying UAV using joint TDOA-AOA measurement processing technique. The contribution of current research is performance evaluation of considered positioning system with AOA noise and confirmation of its practicability to handle NLOS problem, when AOA deviation is less than 10 degrees.
Improving the efficiency of multichannel systems based on the coordination of channel signals
Authors: Voronkov G S , Filatov P E , Sultanov A Kh , Kutluyarov R V , Vinogradova I L , Kuznetsov I V
Published: November 2019

A method for improving the energy efficiency and noise immunity of multichannel systems, based on the overall coordination of channel signals, is described. To coordinate the signals, a coordinating matrix is used, whose elements are the cross-correlation coefficients of signals from different channels. The possibility of reducing the dynamic range of channel signals while maintaining the quality of communication is shown. The possibility of synthesizing invariant (with an unlimited transfer ratio in separate channels) of coordinated group DPCM codecs with channels of the same type is shown.
How to read the trendless sequences: the “universal” set of quantitative parameters
Authors: Nigmatullin R R , Vorobev A S
Published: November 2019

In this paper it is demonstrated a new set of “universal” parameters that help to read quantitatively any trendless sequence (TLS). This method is applied for solving the problem of selection of the “pattern” noise from the tested one and for calibration of random fluctuations expressing some qualitative inputs in terms of these quantitative parameters. This set of quantitative parameters allows to compare the TLS(s) of different nature (acoustic, mechanical, electrochemical, vibrational and etc.) with each other. Using the proposed algorithm, we analysed the differences between software simulated and experimentally generated white noises. We do suppose that the proposed “universal” scheme free from uncontrollable errors can find a wide application in solution of many practical problems.
Modeling the effect of temperature deformations of large elements on the dynamics of the orbital motion of a small spacecraft
Authors: Sedelnikov A V , Rodina V S , Orlov D I
Published: November 2019

The effect of temperature deformations of panels of solar battery of a small spacecraft like “Aist–2D” is modeling in this paper. Temperature deformations occur while a small spacecraft enters and goes into the shadow of the Earth. The effect of temperature deformations on the dynamics of the orbital motion of a small spacecraft is reviewed. Conclusions are made regarding the consideration of temperature deformations for efficient operation of orbital motion control system. The tree-dimensional heat conduction problem was solved during the modeling. Computational modeling was made by the LS-Dyna package. The results of work may be used while creating a small spacecraft with large elastic elements control laws and the shadow segment of the orbit.
Mathematical models of operating regimes of flood control facility’s system
Authors: Antonov V I , Davydov R V , Maslikov V I , Molodtsov D V , Chusov A N
Published: November 2019

The rapid spread of storm floods over large areas requires flood management throughout the river basin by the creation of a system of flood control facilities of various functional purposes distributed in the area. The central part of the system is the hydro system with a hydroelectric power plant. Also, the flood control facilities on the side tributaries with the self-regulating reservoir are included in it. The development of mathematical models is needed to ensure the effectiveness of using flood control facilities, reflecting the specifics of their operation. We have developed unified mathematical models of a hydraulic structure with a hydroelectric power station and a means of protection against floods. These models are implemented in a computer program that provides the ability to determine the main parameters and operating regimes of hydro systems in a wide range of initial data. It makes possible specifying the parameters and operation modes of each hydro system with the current economic and environmental requirements, to assess the energy-economic and ecological consequences in the work of the flood control facilities distributed in the area.
Monte Carlo modelling of normal skin and skin cancer Raman spectra
Authors: Matveeva I , Myakinin O
Published: November 2019

In this paper, we propose an algorithm of Monte Carlo modelling of Raman scattering. A model of Raman scattering in multi-layered tissues has been built. A number and optical properties of tissue layers, number of photons, geometric size of the model and parameters of the light source may be varied by users. Some of computational results have been compared with other investigators.
Clustering based on the principle of finding centers and robust averaging functions of aggregation
Authors: Shibzukhov Z M , Kazakov M A
Published: November 2019

A new approach to robust clustering based on the search for cluster centers is proposed. It is based on minimizing the robust estimates of the averages and the sum of the functions of pseudo-distances to cluster centers. An algorithm of iterative reweighing type for finding cluster centres is proposed. Examples are given showing the stability of the method with respect to a large number of outliers.
Intelligent integrity monitoring system for technological process data
Authors: Arpishkin M I , Vulfin A M , Vasilyev V I , Nikonov A V
Published: November 2019

The relevance of the work is due to the widespread use of network telecommunications in the automated process control system and the high level of danger of replacing, distorting or losing accumulated data on the process progress as a result of the attacker’s influence. Objective: increasing the security of measurement results from unauthorized modification in the databases of information systems of an industrial enterprise by improving process monitoring system based on the intellectual analysis of technological time series. A structural scheme of process monitoring as part of an information protection system in a segment of an automated process control system network has been developed. The algorithm of intellectual analysis of technological time series in the task of detecting violation of the integrity of data on the process progress due to their unauthorized modification was proposed. Evaluated the effectiveness of the proposed solution on field data. Keywords: Monitoring of the technological process, analysis of technological time series, integrity of accumulated telemetry data, neural network model of adaptive segmentation, clustering of technological events.
Application of principal component analysis to identify semantic differences and estimate relative positioning of network communities in the study of social networks content
Authors: Rytsarev I A , Paringer R A , Kupriyanov A V , Kirsh D V
Published: November 2019

In the paper, we propose an approach to the analysis of social groups and their relative positioning based on the identification of semantic differences in texts presented in the form of frequency dictionaries. The initial textual data was obtained by collecting records of thematic Internet communities. To collect entries, we implemented a specialized software module for downloading and analyzing posts as well as comments from open communities of interest in the social network VKontakte. The developed algorithm of frequency dictionary compilation evaluates the characteristics of data collected from social networks. For keywords identification, we propose a new approach based on the analysis of word frequency distribution, using methods for dimension reduction of feature spaces. The presented algorithm using the principal component analysis allowed to assess the significance of words by coefficients of the linear transformation. Along with the keywords, we identified semantic differences of social network communities and estimated their relative positioning in the transformed feature space.
Modification of single-purpose CNN for creating multi-purpose CNN
Authors: Shustanov A V , Yakimov P Y
Published: November 2019

Modern traditional convolutional neural networks (CNN) are built to solve one specific task, which can be: detecting and localizing objects in an image, restoring a human skeletal model, classifying images, etc. However, existing business problems can be a combination of the above subtasks. The simplest way to solve this problem is to use several ready-made CNN models or to train such models, one for each subtask. But this approach leads to a strong increase in the required computing power, which can be economically costly. The approach presented in the article allows reducing computational costs by adding new blocks to the existing CNN and creating a multi-purpose model.
Surface roughness estimation by using a 3D model reconstructed from multiple images
Authors: Viktorenkov A E , Yakimov P U
Published: November 2019

In this paper, the roughness parameters of the part are estimated based on its reconstructed 3D model. Reconstruction of the 3D model was carried out using the structure from motion photogrammetry method. Preliminary processing of the 3D model consisted in fitting the plane to the point cloud of the 3D model using the least squares method, aligning and scaling the 3D model. Also, the resulting 3D model was approximated using the radially basic functions to obtain a uniform cloud of points. Next, the obtained point cloud was filtered to identify 2D and 3D roughness profiles. As filters, a Gaussian filter and 2RC were used. The roughness parameters of the obtained profiles were calculated. A comparison of the roughness parameters calculated on the basis of the 3D model and the roughness parameters calculated by the BV-7669 profilometer was made.
The diffusion-tensor MRI data analysis for cerebral microangiopathy influence detection on the integrity of the brain white matter in Alzheimer’s disease patients
Authors: Gridin V N , Perepelov V A , Solodovnikov V I , Yakhno N N
Published: November 2019

The analysis of diffusion-tensor magnetic resonance tomography data is carried out to assess the contribution of cerebrovascular disease to the violation of the microstructural integrity of the brain white matter in Alzheimer’s patients. The values of DTI (Diffusion Tensor Imaging) indicators are studied for 19 regions of the brain. The issues of data pre-processing, their analysis by statistical and neural network methods, including visualization using Kohonen self-organizing maps, are considered. It provided a number of anatomical structures of the brain that have the greatest specificity in Alzheimer’s disease combined with cerebral microangiopathy in contrast to isolated Alzheimer’s disease. This approach provides important diagnostic information about the involvement of various brain areas in the pathological process.
Flow and heat transfer characters in the integral internal cooling channel of a turbine blade
Authors: Guo Tao , Zhu Huiren , Zhou Zhixiang
Published: November 2019

A scaled model of the integral internal cooling channel of a turbine blade was established for the experimental investigation. The model was made by Perspex for its transparency so that the thermochromic liquid crystal measurement could be used easily. The cooling channel is composed of 3 legs of ribbed channels. Rib with angle 45° was settled in both pressure side and suction side, which forms a cross-rib structure. Three legs were connected by two 180° turns. The main inlet and two addition inlets were arranged in the root of the model channel. Two discharge outlets were located in the tip. A row of outlet holes was distributed along the trailing edge. The channel area gradually decreases along the blade height direction, while bending and torsion occur because of the blade airfoil shape. The aspect shapes and connection methods of the channel were kept in accordance with the real blade. The inlet Reynolds number is from 10000 to 32000. Five outlet discharge ratios were alternated in this investigation. The detailed heat transfer distributions, both in the pressure side and suction side, were measured by transient liquid crystal technic. The characters of heat transfer distribution and pressure drop along the channel were displayed. The effects of flow discharge ratio on heat transfer and pressure coefficient were also described.
Heat transfer at evaporation/boiling in the thin horizontal liquid layer on microstructured surfaces under low pressures
Authors: Zhukov V. I. , Pavlenko A. N. , Bessmeltsev V. P.
Published: November 2019

The results of the experimental study of heat transfer during boiling of n-dodecane on a capillary-porous surface are presented. The surface is coated using a 3D laser printer. The dependence of the heat transfer coefficient on the heat flux density under different pressures and liquid layer heights is studied. The obtained experimental data were compared with the values obtained during evaporation/boiling on a plain surface under the same conditions.
Comparative analysis of heat supply options for small and middle-sized settlements of Eastern Siberia by using uncertain and fuzzy information
Authors: Khan V V , Dekanova N P , Khan P V
Published: November 2019

The problems of heat supply in small and medium-sized settlements of Eastern Siberia are considered. Variants of using cogeneration heat plant (CHP) or boiler plant on coal or wood waste, the use of liquid petroleum gas (LPG) and liquid natural gas (LNG) as a fuel, the use of electric boiler plant or stand-alone electric boilers, applications of solar collectors and heat pump installations are considered based on a systems approach and fuzzy modelling, by taking into account the uncertainty of some factors.
An analytical model of subcritical and critical vapor-liquid flow through a granular bed
Authors: Tairov E A , Khan P V
Published: November 2019

This paper presents a computational and experimental justification of a theoretical model for the two-phase vapor-liquid flow through a fixed bed of solid particles. The theoretical description is based on the equations of gas dynamics of the granular bed and the homogeneous model of a single-component two-phase flow, given the difference between the velocities of liquid and vapor phases. Relationships between the phase slip ratio and polytropic coefficient of isenthalpic expansion of vapor-liquid flow were obtained using the multi-parameter nonlinear regression. We used the experimental data on the vapor-liquid flow with an inlet pressure, P
1, of 0.6-1.2 MPa and an inlet flow quality, x
1, of 0.016-0.178 through a H=50-355 mm bed consisting of steel spheres, 2 and 4 mm in diameter, d. An expression for the critical pressure ratio in the granular bed is proposed. The developed model makes it possible to predict the values of mass velocity of the mixture over the entire range of experimental data with an average error of 3%. Based on the model equations, we obtained expressions for dimensionless mass velocity depending on the pressure ratio that can be applied to two-phase flows through both granular beds and other porous media.
Optimization of phase change material component and its application in buildings
Authors: Wang M Y , Cui H Z , Liu Y , Bao J Y , Yang L
Published: November 2019

Improving the thermal transfer performance of phase change material (PCM) component has attracted more and more attention in building the energy-saving field. This paper presented an optimized PCM component which is encapsulated in a metal container, to promote the thermal performance of the wall. Thermal transfer of PCM component is optimized by adding internal fin through numerical simulation software COMSOL Multiphsics. The simulation model was verified by data from publicly available published literature. The temperature difference of PCM component in front and back heating surface (ΔT
s) was employed to obtain the optimal geometric parameters including spacing (S
fin) and length (L
fin) of the fin. Thermal performance of the wall with the optimized and non-optimized PCM component was compared under the summer typical climate. The wall with optimized PCM component has the best capacity for heat storage and release. The interior surface temperature reduction of the wall with optimized PCM component is lower by 2.1 ºC than reference wall.
Influence of the coal-derived synthesis gas composition on the thermal stability of ZnO sorbents in the desulfurization process
Authors: Kagramanov Yu A , Ryzhkov A F , Tuponogov V G , Nikitin A D
Published: November 2019

The priority direction of thermal energy on solid fuels is to increase efficiency and environmental safety, approaching zero emissions of harmful substances. To achieve these goals, they are currently creating new schemes for combined cycle gas turbine units with intra-cycle gasification (IGCC). To improve the efficiency of the IGCC cycle, hot dry desulfurization (HGC) technologies are being developed. HGC uses regenerable sorbents that allow the repeated adsorption of hydrogen sulfide from synthesis gas, among which the most acceptable thermodynamic and operational characteristics are based on ZnO sorbents. The article uses the method of thermogravimetric analysis (TGA) to investigate the development of target reaction capture hydrogen sulfide ZnO-containing sorbent and sorbent reactions with components of synthesis gas in the temperature range up to 1000°C. The sorbent calcined at 900°C shows thermal stability in an inert atmosphere over the entire temperature range studied. Uncalcined sorbents at temperatures of 200 and 600°C emit carbon dioxide in an amount of 1.5-4.5% by weight of the sorbent. At temperatures up to 550°C, the target reaction is basic, and side reactions practically do not develop. The maximum rate of absorption of hydrogen sulfide by the sorbent is observed at a temperature of 600°C. At 500-550°C reactions of a sorbent begin with H2 and CO, at 750-800°C – with carbon, at 850°C – with CH4. The intensity of effect of reagents is defined on degradation of a sorbent by reactionary ability of gases more than temperature.
Investigating the gas-droplet flow generated by a pneumatic nozzle for a coal-water slurry
Authors: Anufriev I S , Kopyev E P , Maltsev L I , Yu Shadrin E , Sharypov O V
Published: November 2019

The paper studies a promising method of spraying, based on the interaction of cumulative and near-wall jets with the impinging liquid and the Coanda effect. The measurements are based on shadow photography (SP) and interferometric method (IPI). In a wide range of performance parameters data have been obtained on the disperse composition of a gas-droplet flow at water spray by a special pneumatic atomizer intended for coal-water fuel. The dependences of droplet sizes on the flow rate of liquid and spraying air have been found.
Investigating substandard liquid hydrocarbons spraying by a steam jet
Authors: Anufriev I S , Kopyev E P , Mukhina M A , Osintsev Ya A , Yu Shadrin E
Published: November 2019

Using the shadow photography (SP) method and the interferometric method (IPI), a two-phase gas-droplet flow was experimentally investigated when the spent transmission oil was sprayed by a jet of superheated steam. In a wide range of operating parameters, data on the dispersed composition of the steam-fuel jet have been obtained. The dependences of droplet sizes in the flow on the studied regime parameters have been established.
The influence of the surface structuring type on heat transfer in falling films of the refrigerant mixture
Authors: Volodin O A , Pecherkin N I , Pavlenko A N , Zubkov N N
Published: November 2019

The paper considers the influence of enhanced surfaces on heat transfer during evaporation and boiling of a falling laminar-wave liquid film. A mixture of R114/R21 refrigerants was used as a test fluid. The liquid film flowed on the outer surface of vertically-oriented cylinders. To intensify the evaporation process, the authors used the mesh coatings with variable mesh sizes, whereas the surfaces with variable characteristics of microstructure obtained by deformational cutting were used to enhance boiling. The report makes a conclusion about the studied types of structured surfaces, most effective for enhancement of heat transfer in different regimes. It is shown that the mesh coatings intensify heat transfer at evaporation twice as compared to a smooth surface; the microstructured coatings with partly-closed micropores obtained by deformational cutting allow fourfold heat transfer intensification at boiling.
HEAT TRANSFER AT BOILING OF LIQUID FILM IRRIGATING A HORIZONTAL BUNDLE OF ROUGH TUBES
Authors: Gogonin I.I.
Published: November 2019

According to experiments with film irrigation of packing of tubes with artificial roughness, boiling on them begins at very low-temperature heads. Heat transfer at boiling on these tubes is noticeably more intense than that on a smooth tube.
Use of computational realistic models for the cardiac ejection fraction calculation
Authors: Huérfano Y , Vera M , Vera M I , Valbuena O , Gelvez-Almeida E , Salazar-Torres J
Published: November 2019

Ejection fraction is one of the most useful clinical descriptors to determine the cardiac function of a subject. For this reason, obtaining the value of this descriptor is of vital importance and requires high precision. However, in the clinical routine, to generate the mentioned descriptor value, a geometric hypothesis is assumed, obtaining an approximate value for this fraction, usually by excess, and which is a dependent-operator. The aim of the present work is to propose the accurate calculation of the ejection fraction from realistic models, obtained computationally, of the cardiac chamber called right ventricle. Normally, the geometric hypothesis that makes this ventricle coincide with a pyramidal type geometric shape, is not usually, fulfilled in subjects affected by several cardiac pathologies, so as an alternative to this problem, the computational segmentation process is used to generate the morphology of the right ventricle and from it proceeds to obtain, accurately, the ejection fraction value. In this sense, an automatic strategy based on no-lineal filters, smart operator and region growing technique is propose in order to generate the right ventricle ejection fraction. The results are promising due we obtained an excellent correspondence between the manual segmentation and the automatic one generated by the realistic models.
Mathematics, resilience and development of thinking of youth
Authors: Santiago Carrillo M C , Vergel Ortega M , Rojas Suarez J P
Published: November 2019

The main objective of the research was to evaluate the relationship between academic performance in mathematics and the school success. The research follows a quantitative approach with factorial design, type descriptive-comparative and micro sociological in its sample coverage. The results obtained reflect that there is a significant relationship between emotional resilience skills, the level of application, abstraction and academic performance. It is concluded that successful students demonstrate an improvement in their creative thinking and mathematical thinking, and their resilience level improved.
Level of development of mathematical logical thinking in the students of the agricultural areas of the Universidad Francisco de Paula Santander, Ocaña, Colombia
Authors: Garcia Quintero C L , Durán Chinchilla C M
Published: November 2019

The Francisco de Paula Santander branch school in Ocaña, Colombia; especially the zootechnics program, concerned about the low performance of students in the mathematics or related areas. (Especially in the new students), decide to carry out a study that allows determining what is the level of development of logical thinking in the students of the agricultural areas. For it, a mixed research with the focus of exploratory research was implemented. A workshop was applied and designed based on the principles of Feuerstein, which led to the development of different mental and cognitive operations; these workshops allowed to determine elements such as identification, evocation, comparison, analysis, synthesis, classification, deduction, induction, and divergent and inferential reasoning; there are also some basic mathematical operations such as fractions, decimals, mixed numbers, and conversion. In this case, more than 50 students from third semester in zoology classes took the workshop. The results gave a diagnosis, the evidence that the students have not developed the capacity for abstraction, inference, or the application of algorithms. The idea is that the results will design pedagogical strategies that will help improve the academic performance of students in the area of mathematics.
Review of techniques, tools, algorithms and attributes for data mining used in student desertion
Authors: Diaz Pedroza K Y , Chindoy Chasoy B Y , Rosado Gómez A A
Published: November 2019

This article makes a review of the application of data mining in the academic desertion of the students; with the aim of finding common elements used by different authors about desertion. The search of the articles was carried out in digital libraries, indexed journals, institutional repositories among others. The selection criteria were based on the depth of the techniques, algorithms, tools and attributes used in the publication. Among the results we have that most of the researches are related are supervised learning, we have the classification as the most applied technique and we use the algorithm j48 and the variable or class to predict as the academic state.