bluuebunny/crossref_metadata_2025 huggingface dataset:
An approach for generating and detecting the signals with the given orbital angular momentum for wireless communication systems
Authors: Grakhova E P , Meshkov I K , Abdrakhmanova G I , Bagmanov V Kh , Vinogradova I L , Gizatulin A R , Kuk I A , Sultanov A Kh
Published: November 2019

The paper is devoted to the development of methods for increasing the efficiency of wireless communication channels via the usage of multiplexing by the orbital angular momentum (OAM). This wave property allows us to form an additional basis of orthogonal functions for the simultaneous independent transmission of several signals. In particular, we propose the uniform circular antenna array (UCA) operating in the 77 – 78.5 GHz frequency range designed to generate radio beams with various orders of the OAM without changing its configuration. The important points in the UCA’s design process were ensuring the minimum divergence of the beam during the propagation and obtaining the maximum gain. Regarding the OAM radio beams receiver, we propose a solution for detecting an OAM signal in case of misalignment between transmitting and receiving antennas. An antenna array consisting of two perpendicular dipoles is employed as a receiving device, providing the OAM signal reception from any direction. An important point of signal detection is the preservation of the information about the phase of the received signal. Finally, we demonstrate the simulation results of OAM signal transmission and reception.
Development of a mathematical model of molecular-selective gas transfer in a hybrid membrane-adsorption oxygen concentrator
Authors: Tishin A A , Gurkin V N
Published: November 2019

Most modern oxygen concentrators use sorption air separation technology. The development of a hybrid membrane-sorption separation technology can improve the energy efficiency of the process. The paper considers a mathematical model of molecular-selective gas transfer in a hybrid oxygen concentrator consisting of adsorption and membrane units combined into a circulation loop. The considered hybrid model has based on a model of equilibrium isothermal sorption with linear isotherms without longitudinal mixing for numerical calculation of the adsorption unit of the system and a model of ideal displacement in the high-pressure cavity with perpendicular outflow in the low-pressure cavity to calculate the system membrane unit. In the course of the study, the high adequacy of the model was obtained with an experiment in the range of oxygen concentrations up to 90%, and a comparison was made with previously obtained results. A new model has been proposed that can take into account the equalization and countercurrent blowing stages.
The influence of the ignition conditions of the SH-synthesis of intermetallic compounds on the combustion parameters of the Ti-15.82wt.%Al composition: computer simulation and computing experiments
Authors: Jordan V I , Shmakov I A
Published: November 2019

Computational experiments (CEs) have been carried out to simulate the propagation of the combustion wave of the SH-synthesis process in a package of alternating layers of nanoscale crystal lattices of Ti and Al atoms by molecular dynamics method. The interatomic interaction potential in the embedded atom model (EAM) was used in the LAMMPS package. Using the LAMMPS configuration with parallel computing, the following results of CEs were obtained: sets of temperature profiles along the layers of the structure at successive instants of time (up to 16 ns) and the corresponding sets of snapshots (vertical cross-sections of the atomic arrangement along the layers), as well as a tables with the number and percentage of the content of various types of elementary cells (fcc, hcp, bcc, other) at the same instants of time. The influence of the initiation’s conditions of the SH-synthesis of intermetallic compounds on the combustion parameters of the nanoscale layered Ti-15.82wt.%Al composition was showed. The ignition conditions of SHS that are provided the stable motion of the combustion wave in the SHS-sample were determined. And the ignition conditions of SHS with dominance of either TiAl or Ti3Al phase formation in the SHS products was also determined.
Modeling of phonon diffusion using a Monte-Carlo method based on physics of phonon
Authors: Khvesyuk V I , Qiao W , Barinov A A
Published: November 2019

Modern studies of heat transfer in semiconductor and dielectric structures (integrated circuits, etc.) are based on the analysis of the interaction of quasi-particles called phonons – quanta of elastic waves propagating inside the crystal lattice. In this paper, it is shown that to describe the diffusion it requires a detailed analysis of the physics of phonons interactions. Firstly, we formulated a method to perform a phonon diffusion calculations which takes into account the peculiarities of phonon interaction. Secondly, we developed a brand-new algorithm, which allow to carry out a computer simulation of phonon diffusion. Obtained results are necessary both for a deeper understanding of the processes of heat transfer, and for future calculations of the contact thermal resistances and phonon scattering on the boundaries – the relevant problems of heat transport in nanostructures.
Development of a mathematical model of operation forming with discounting assumption about the flat-deformed state
Authors: Demyanenko E G , Kosolapova A Yu
Published: November 2019

For development and improvement, technological processes are a necessary strict analysis of the maximum numbering factors most strongly influencing the deformation process and flat-deformed strain state procurement blank. When determining the strained and deformed conditions of blank lead the admission about the flat-deformed state, which ensures the minimal thickness variation thin-walled detail by forming process. In this article, the complex method of researches including the theoretical analysis and check of the entered condition in the program ANSYS complex is used.
Model for discrete optimal control of the enterprise’s financial processes
Authors: Orlova E V
Published: November 2019

We consider a problem of financial resources planning where the processes of financial flows coordination of an enterprise under uncertainty are described with the discrete optimal control approach and methods of dynamic programming. We give a critical survey of theoretical and methodological approaches for financial resources planning problem. The financial flows dynamics is modelled with using the methods of system analysis, control theory, optimal control and methods of data processing under uncertainty. The model for the financial flows distribution has been developed. It uses the principles of optimal dynamic control under the criterion of cumulative non-payment risks and transaction and opportunity costs minimizing. The practical significance of the developed model is in its application for the financial planning in the enterprises that allows to improve its financial planning quality and to increase its management and operational efficiency.
Modeling of brightness temperature in biological tissue
Authors: Polyakov M , Levshinskii V , Khoperskov A
Published: November 2019

Microwave radiothermometry is a passive and non-invasive technique which is used to measure the depth temperature of biological tissue. The method of microwave radio thermometry is based on measuring the intensity of the own electromagnetic radiation of the internal tissues of the patient in the ultra-high frequency range. The temperature measured by the instrument is called brightness. Modeling the brightness temperature is carried out to research the effectiveness of the method of medical diagnostics based on microwave radiothermometry data. A mathematical model of the distribution of the electromagnetic and temperature fields in the mammary gland was built. A numerical simulation of the electromagnetic and temperature fields for models differing in internal structure was carried out. The structure of the mammary gland is a multicomponent, heterogeneous environment and consists of the following types of biological tissues: skin, adipose tissue, muscle tissue, milk lobules, blood flow. The contribution of the electromagnetic field to the formation of the brightness temperature was determined. The dependence of the brightness temperature on the radius of the tumor is presented.
Numerical optimization of geometric configuration of large space structure
Authors: Anshakov G P , Salmin V V , Peresypkin K V , Chetverikov A S , Tkachenko I S
Published: November 2019

The paper considers a development project of an observation satellite with diffractive optical system. The problem of stable orientation of the optic system elements is being solved. The design layout suggested by the authors earlier is used for the purpose. The authors studies influence of geometrical parameters on stiffness of the design. With the help of numerical optimization optimal values of design parameters are found, optimized for minimum of mass.
Computational simulation of damage accumulation processes in cracked bodies by the UMAT procedure of SIMULIA Abaqus
Authors: Stepanova L
Published: November 2019

The paper presents the experience of using the user subroutine UMAT for finite element package SIMULIA Abaqus/CAE for damage accumulation processes in the vicinity of the crack. A continuum damage mechanics model based on the constitutive relations of linear elastic isotropic materials with the incorporated damage tensor components is used to describe the material behavior. The material nonlinearity arising from the deformation process is modeled by introducing an anisotropic damage tensor of the second rank into the constitutive equation. The material model is described by means of user procedure UMAT of SIMULIA Abaqus. The finite element (FE) mechanical constitutive model is implemented in Abaqus/Standard via a UMAT routine. Numerical experiments for a large series of cracked specimens have been performed. Computed stress and damage tensor components were found. It is shown that they are not dependent on the FE mesh refinement. Distributions of the damage tensor components in the vicinity of the crack tip in cracked specimens of different configurations under mixed mode loading in a wide range of mixed mode loadings are found. The configurations of active damage accumulation process zone in the cracked specimens are obtained. It is shown that the damage accumulation process has substantial influence on the stress-strain state in the vicinity of the crack tip and leads to decrease of the stress concentration in cracked specimens.
Steady state numerical calculation of the melt-pool shape
Authors: Avdeev E V
Published: November 2019

A two-dimensional steady-state melting problem is numerically simulated. This task arose during the Selective laser melting (SLM) additive process technology modeling project. The initial problem is the formation of residual stresses and, as a consequence, the appearance of accumulated deformations (inherent strains) and distortion of final production shape. As the solution of this initial problem suggested the development of its own appropriate software tool. The development process was divided into 5 stages. Stage 1 is to model the geometric size of the molten bath. A comparison of the results obtained within OpenFOAM (laserConvBC) and results from a similar article.
Study of the separation processes of gases in the microchannel based on the stochastic simulation
Authors: Potienko K I , Agafonov A N
Published: November 2019

One of the main problems in the development of microfluidic gas chromatography columns is the complexity of the preliminary modelling of the microfluidic systems, namely, the complex modelling of physicochemical processes on the inner surface of the microchannel walls and the simulation of carrier gas movement. The purpose of this work is to develop an integrated computer model for the separation of sample gas components in a gas chromatographic column that takes into account the effect of the carrier gas on the gas- sample particles and adsorption processes in the surface layer. The proposed model is based on stochastic method. The simulation results can be used to improve the development of microfluidic gas chromatography columns and other devices in which the separation of gas mixtures occurs.
On oscillation appearance in one chemical problem
Authors: Shchetinina E V
Published: November 2019

The paper is devoted to the investigation of the Brusselator model under the assumption that the concentrations of initial substances slowly changing in time. This is the reason for the appearance of the delayed loss of stability effect. The existence of oscillations is studied.
Calculation of residual stresses in plasma spray coatings taking into account the build-up process
Authors: Bogdanovich V I , Giorbelidze M G
Published: November 2019

Methods of calculation of residual stresses in plasma coatings considering extension process for different cases of substrate attachment that are the most common in deposition practice have been developed. According to the developed methods, analytical calculations and experimental research of residual stresses for the coating composed of 70% Al+30% BN have been done.
Construction of the mathematical model of a catalytic reaction by means of a perceptron with one hidden layer
Authors: Almakaev R R , Koledin S N
Published: November 2019

Mathematical models for the homogeneous catalytic reaction between alcohols and dimethyl carbonate were developed using the least-squares method, a perceptron with one hidden layer, and the law of mass action. The structure of a trainable neural network is presented. The relative deviation error between the calculated and experimental values is minimum when the perceptron model with one hidden layer is used.
Digital Transformation Legacy Social Service Information System
Authors: Popov S B , Khripunov P V
Published: November 2019

The article considers the methodological aspects of the digital transformation of legacy social service information systems. The result of this transformation is the social service digital platform that ensure the use of new innovative technologies for processing and analysing big data, machine learning and artificial intelligence. The base of this transformation is cloud computing; big data technology; microservice architecture with container-based software development technology. We propose a person digital profile as a basis of data management in the social service digital platform. The proposed one is based on a new abstraction level of software stack – dataware. The implementation uses a microservice architecture and a container-based software development technology in according to the Data-as-a-Service concept.
System approach to identification of geopulses
Authors: Gapeev M I , Senkevich Yu I , Lukovenkova O O , Solodchuk A A
Published: November 2019

A new system approach to the identification and systematization of geophysical pulses is described. It includes stages of detection, analysis, object and structural description, pulse classification. In order to identify the pulses in geoacoustic emission, we apply a method based on the calculation of adaptive threshold, the values of which are estimated by the results of signal root-mean-square deviation in a moving window of a defined size. The detected pulses are described and identified by an adaptive matching pursuit algorithm which allows us to decompose the pulse into linear combination of basic functions from a combined Gauss-Berlage dictionary with minimum spatial and time costs and with the required accuracy of constructed approximations. Within the framework of object approach, pulses are described by a combination of features such as the number of functions in a decomposition, function type, parameters etc. We present a method of reduction of innumerable diversity of identified pulses to a denumerable set of patterns. It is based on structural transformation of geoacoustic emission pulses with simultaneous automatic procedure of classification. The results obtained during the application of the described system approach to the analysis of geoacoustic signals are summarized in a Geophysical Signal Catalogue.
Use of a vertebra digital model for an implant design
Authors: Abulkhanov S R , Surkov O S
Published: November 2019

In this paper, we consider some possible design options for the reconstruction of an injured vertebra based on the local information on its surface before the injury. We used the methods of guaranteed identification for the reconstruction of the vertebra surface. Using the vertebra surface model, we have developed designs of anatomically shaped vertebra implants. In this case, the vertebral implant has a foramen vertebrale. Therefore, we have designed a split-type implant. To ensure the stiffness of the implant assembly, we have considered two fastening options for implant structural components: the dovetail groove mounting and fastening with asymmetric surfaces. Taking into account the existing best practices in medicine and in order to fasten implant structural components, we have selected options for connecting the components by means of asymmetric surfaces and with fasteners. In our opinion, the considered fastening options for vertebral implant components can be used in the replacement of other bones. When designing an atomically shaped vertebral implant, we selected a structure that weighed as close to a natural vertebra as possible. We also designed the structure to maximize its load-carrying capacity. We suggest to produce implants from blocks of allogenic osteoplastic material. This will enable implant components to be set properly and not to be rejected by the immune system.
Fano approximation for coupled modes in metal-dielectric multilayer structures
Authors: Nesterenko D V
Published: November 2019

We study the response of coupled modes in metal-dielectric multilayer planar structures consisting of a metal layer attached to a high-index waveguide by a low-index spacer layer. The structure supports excitation and coupling of a surface plasmon polariton mode and a waveguide mode. A coupled-mode model is developed to analyse the field transfer processes and describe the appearance of Fano resonances as a result of the modes interaction. It is demonstrated that the response of the plasmonic mode can be well fitted to a Fano function that allows extraction of width, height, sensitivity, and field enhancement.
Research Inside a Gas Heating Device with Different Heat Transfer Medium
Authors: Guo Yun , Zhou Zhongwei , Chen Hao , Ouyang Yeyu , Huang Zhiqiang
Published: November 2019

Natural gas heating device occupies an important position in natural gas industry, and the most widely used one is the cylindrical heating device with heat transfer medium. The key factors affecting the thermal efficiency of the cylinder gas heating device with heat transfer medium are the type of heat transfer medium and the flow field organization. In order to study the influencing factors of thermal efficiency of the heating device, a visualized practical gas heating device experiment system was established, and a two-dimensional heat transfer model fitting the real object was established, too. The unstructured fitting mesh was used to divide the physical model, and the finite volume method was used for discrete solution, while discrete coordinate (DO) radiation model is used to solve radiation equation. In this paper, water and ethylene glycol are used as heat transfer media to simulate and measure the heat flow field in the cylinder. The results show that ethylene glycol can broaden the application range of gas heating device. Under the same experimental conditions, the heat efficiency of the heating device with ethylene glycol as heat transfer medium is at least 3.8% higher than that of the heating device with water as heat heat transfer medium. The thermal efficiency of gas heating devices is generally less than 87%.
Investigation of the features of polyolefins and wood biomass thermochemical conversion for their energy utilization
Authors: Donskoy I G , Shamanskiy V A , Kozlov A N , Penzik M V , Kozlova M A
Published: November 2019

Combustion of solid combustible wastes is the most common way of their disposal. In developed European countries, up to 50% of all municipal waste is burned; in Russia, it is estimated to be less than 2.5%. The efficiency of modern thermal plants operating on MSW and biomass, as well as the capacity of individual combustion units are continuously increasing, approaching the average values that are close to fossil fuels plants. Replacing coal with combustible waste will make it possible to reduce the cost of energy production and reduce the load on waste landfills. However, to this end, it is necessary to solve the problems of organizing efficient combustion as well as cleaning of combustion products. Of particular interest is the co-processing of municipal waste along with lignocellulosic waste from agriculture and the forest industry. In the present work, the thermal behavior of woody biomass and polyethylene mixtures (in different mass ratios) when heated in an oxidizing environment is investigated using methods of thermal analysis. The distribution of the products of pyrolysis and oxidation is investigated by means of mass spectrometry.
Flow and heat transfer of fluid in a pulsating heat pipe
Authors: Sharma Megha , Singh Sikarwar Basant
Published: November 2019

Cooling of electronic components are preferred heat pipes imbedded in heat sink because of high heat transfer through them. The oscillating motion of the working fluid due to continual phase change facilitates both sensible and latent heat transfer in pulsating heat pipes. This enables transfer of high heat flux efficiently over long distances. In this work, a mathematical model is developed to optimize the parameters which involves in heat pipe design. The parameters are filling ratio, size of tubes and degree of temperature. In House Finite Volume based CFD solver is used for simulation. The obtained simulation results are validated against experimental results present in literature. These results are useful for understanding thermos-hydrodynamics of pulsating heat pipe for achieving maximum thermal performance
Moist Air Condensation on Inclined Hydrophobic Metallic Surfaces: Simulation & Experiments
Authors: Baghel Vishakha , Singh Sikarwar Basant
Published: November 2019

Atmospheric Water Generators (AWGs) are popularly used for harvesting portable water from atmospheric air of hot, humid and arid regions of the world. Hydrophobic metallic surfaces are preferred in AWGs systems because condensation of moist air on/underneath these surfaces have high efficacy. There are several issues to fabricate hydrophobicity on metallic surfaces. Although with the advent of Nanotechnology and thin film coating technologies, the fabrication of hydrophobicity on metallic surfaces has become easier and realizable in the recent era. In this manuscript, a comprehensive mathematical model is developed for simulating the moist air condensation in the form of droplets on various substrates and in different environmental conditions. The experiment is carried out for validation of the present model. Post validation, the effect of surface hydrophobicity, relative humidity and degree of sub-cooling on the condensation rate are addressed. The simulation results show that vertically orientated metallic surfaces having a high contact angle along with low contact angle hysteresis are efficient for condensing unit. Larger condensation rates are observed at higher relative humidity and a high degree of sub-cooling. This research is helpful for designing efficient and effective AWGs for the hot and humid region.
Numerical study of combustion of the diesel fuel sprayed with a steam jet in a prospective burner device
Authors: Krasinsky D V , Tsepenok A I
Published: November 2019

A prospective laboratory-scale burner device that employs a concept of liquid fuel spraying in the high-speed superheated steam jet is considered. The presented work is devoted to numerical study of aerothermochemical processes occurring in this novel-design burner during the combustion of diesel fuel sprayed with axial jet of water steam. The mathematical model is based on Euler-Lagrange approach for two-phase turbulent reacting flow description applied in 2D axisymmetric steady-state formulation. The vaporized diesel fuel combustion is described via EDC model with chemical kinetics mechanism for n-heptane (30 species, 66 reactions). The two-step soot model is also used, as well as NOx prediction at post-processing stage. The fields of velocity, temperature, heat fluxes, gas species and disperse phase concentrations, including soot and NOx, have been obtained from numerical simulation for a typical operational mode with diesel supply rate of 1.2 kg/hour and water steam flowrate of 0.8 kg/hour. Analysis of these flowfield data has allowed to reveal the two-layer coaxial structure of reacting flow (consisting of relatively cold near-axis jet layer and the coaxial layer formed by the hot recirculation zone) inside the burner.
Two-phase compact heat exchangers: a review and future applications for high heat flux removal
Authors: Kuznetsov V V , Shamirzaev A S
Published: November 2019

The compact flow heat exchangers are important components of the equipment for power generation, chemical processing, and thermal environment control. This paper presents the flow pattern characterization and heat transfer performance for two-phase compact and ultra-compact heat exchangers. The scaling analysis is presented in this paper to identify the effect of various forces. The heat transfer enhancement mechanisms during flow boiling and condensation in compact heat exchangers are discussed using experimental data for refrigerant R-21. The mechanisms of subcooled and saturated flow boiling in ultra-compact heat exchangers based on microchannels are discussed using experimental data obtained for water.
Heating and cooling of a battery pack of a solar electric car
Authors: Kasatkin Ivan , Egorov Mikle , Zakhlebaev Evgeny , Kotov Evgeny
Published: November 2019

The purpose of the research is to analyse forced air cooling of a solar electric vehicle battery. Due to the conditions of safe battery performance, it is obligatory to keep its temperature under 45°C, so cooling should be provided. The battery pack is assembled of 420 battery cells with square pitch. At normal operating conditions of the solar car a forced air cooling thermal calculation is performed. Hydraulic calculation is carried out. The air pressure loss magnitude is calculated. A comparison of the geometric parameters of the corridor beam is presented. Based on a steady-state heat transfer analysis and hydraulic calculation, suitable airflow parameters and battery pack layout are selected.
Heat and mass transfer in the boundary layer during evaporation of aqueous solutions of ethanol and acetone into air and superheated vapor components of solutions
Authors: Makarov M S , Makarova S N
Published: November 2019

A stationary flow of three-component gas in a laminar boundary layer on a flat plate is considered at adiabatic evaporation of a two-component liquid film. Numerical modelling were carried out at atmospheric pressure, air flow velocity of 2 m/s and temperature from 20 to 500 °C in the whole range of concentrations of a low-boiling component of binary solutions: ethanol/water, acetone/water, and acetone/ethanol. Data on the local specific evaporation rate of ethanol/water and acetone/water solutions into dry air and superheated mixture of ethanol, acetone and water vapors were obtained depending on the temperature of the inlet flow. Composition of superheated vapor mixture was taken to be equilibrium relative to the liquid solution. With an increase in the molar fraction of ethanol or acetone in the water solution, the evaporation rate increases, and when evaporated into superheated vapor, the growth of evaporation rate with increasing vapor temperature is significantly higher than at evaporation into air. With an increase in ethanol or acetone concentration in the liquid solution, the inversion temperature decreases from down to 155…165°C.
Numerical simulation of flow with evaporation in triangular grooves
Authors: Sibiryakov N , Kabov O
Published: November 2019

We study the flow of an evaporating liquid film in triangular open microchannel. Above the surface of the liquid flows a gas. The sear-stress on the gas-liquid surface drags the liquid and removes the vapor. It models either flow in a channel or a flow in a single groove. The novelty of this work is that we simulate gas-driven flow with evaporation. We use Boundary element method to solve Laplace equation with mixed boundary conditions. This method gives the normal derivative of vapor concentration at the surface of the liquid. The resulting evaporation flux is growing sharply near the contact line. Integral evaporation coefficient slightly depends on the depth of the liquid. The upper gas flow drives the liquid film, resisting a velocity drop and preventing the dry spot formation.
Energy conservation and the use of the heat of refrigeration of ice arenas to heat the school of figure skating of St. Petersburg
Authors: Kondrashov A. , Egorov M.
Published: November 2019

A variant has been proposed for using the system for utilizing the heat of condensation of heat engines, most of which has not been used and released into the environment, for air heating of ice arenas. An analysis of unused heat energy was made using the example of a refrigerating machine, which, in addition to cold production, also produces a significant amount of heat that is generated during the compression of the refrigerant in the compressor to the pressure and condensation temperature, and in most of the existing refrigeration units, thermal energy is not used and transferred to the environment using air condensers or cooling towers located on the street. The analysis of the economic efficiency of the use of heat recovery systems, for various technical needs. A study was carried out on the actual implementation of the system of partial utilization of the condensation heat of refrigerating machines, which is aimed at air heating of ice arenas at the St. Petersburg State Budgetary Institution of the specialized school of Olympic reserve on figure skating (hereinafter referred to as the “Institution”).
Effect of the armed conflict in Santander North 1990-2012 an impact measurement
Authors: Zambrano Miranda M D J , López D J Manzano , Sánchez A Botello , Pinzón Solano C H , Alvarez M Pontón
Published: November 2019

The armed conflict in Colombia has been a scourge that has disrupted all social dimensions of the country, provoking a humanitarian drama and a high economic cost that has been lived for decades. The purpose of this article is to estimate the effects of the armed conflict on economic growth in Norte de Santander, Colombia in the period 1990-2012; the conceptual framework is the solow-swan model of economic growth and the methodology is to determine the impact of the armed conflict on the growth behavior of the gross domestic product of the Nation and the department of Norte de Santander. Using the synthetic pairing methodology method, it is possible to estimate the impact in contexts in which an aggregate unit (such as a country or department) is being treated or exposed to an intervention. The results show that if there had been no armed conflict, Norte de Santander department would have had a better economic performance. The present article has a sequence after this brief introduction, a state of the art, followed by a methodological explanation, the results and finally some general conclusions.
Mathematical model of the firing process in Ladrillera Ocaña, Colombia
Authors: Nolasco C , Gurrero Gómez Jácome G , Gómez Campero J A
Published: November 2019

The process of heat transfer by conduction is relevant in different context of engineering. Quantify temperature is very important in energy efficiency of firing process. The aim of this work is to establish a mathematical model to determine the firing process at the burner door of the Hoffman kiln of Ladrillera Ocaña, Colombia. For the data acquisition, a virtual instrument was designed for the temperature data collection system. The analytical solution proposed for the model presents a high degree of difficulty. As an alternative, two solution schemes are proposed using numerical methods that are very close to the theoretical model.
Adoption of corporate governance practices in the computer science environment. Mexican food franchise analysis in the Colombian context
Authors: Virgüez J F , Castro Silva H F , Puentes Velásquez A M
Published: November 2019

In a globalized world characterized by aggressive competition in all sectors of the economy, it is essential that organizations establish adequate corporate governance in order to properly coordinate interests within the organization to generate wealth. One of the models associated with corporate governance is the balanced scorecard consisting of four perspectives. This work provides an important input to consider within the organizational goals in the perspective of the balanced scorecard client in Mexican food franchises in Cali - Colombia, as is the client’s knowledge. The research approach is mixed and predominantly descriptive. As a result of the study there is a consumer profile in Mexican food franchises in the city of Cali. Thus, the average consumer of Mexican food is a young person, of medium socioeconomic status and who shares in family the consumption of this type of food. In addition, the study identifies the main variables that determine the decision to consume Mexican food, such as the possibility of home shopping through mobile applications, hygiene and food presentation.
Real-time analysis as an alternative for diagnosis and control of vehicle emissions in the province of Ocaña, Colombia
Authors: Valdes-Solano D M , Fonseca-Herreño L C , Alba-Maldonado J M
Published: November 2019

In Colombia, the increasing use of motorcycles as an informal conveyance has emerge as a means of labor survival for people with limited resources. Mototaxism has rapidly become the main means of transport in the spatial structure of the city of Ocaña; however, high emission rates may present an environmental problem. The study and implementation of strategies for the mitigation of greenhouse gas, is of great help for the reduction of the emissions of these gases. Environmental control of vehicles in Colombia is carried out through an annual technical-mechanical and gas inspection, which seeks to control the emission of pollutant gases from vehicles; however, electrochemical gas sensors may provide an accurate and convenient alternative, as it can be implemented as an analytic tool in gas monitoring and control systems allowing different approaches for the control of vehicle exhaust emissions. A development board such as Arduino can be programmed with an algorithm that utilizes a combination of sensors and connectivity modules, constituting a microcontroller unit that is able to achieve successful monitoring over emission gases, one such algorithm is proposed by the authors.
Development of a virtual instrument for the calculation of thermal efficiency under the assumptions of standard cold air in a 3500cc diesel engine
Authors: Regino F J , Gómez JA , Jaramillo HY
Published: November 2019

This work presents the development of a virtual instrument for the acquisition of temperature data of a 3500 cc diesel engine and the calculation of its thermal efficiency at three different speeds, the analysis was made according to the standard cold air parameters for a diesel engine. To measure the temperature, type K thermocouples distributed around the combustion chamber and the engine exhaust was used; the data acquisition was carried out through a cDAQ-9178 and a NI-9213 thermocouple module from National Instruments.
Analysis of the mechanical characteristics in mortar mixtures with the incorporation of corn leaf fibers
Authors: Jaramillo H Y , Gallardo R J , Gómez J A
Published: November 2019

This article presents the results of an experimental design research work, aimed at adding the fibers of the corn leaf to the cement mortar matrix 1:3, performing tension and compression, humidity and density tests to determine the degree of final resistance of the new reinforced mortar. Once described the way in which the fiber of the corn leaf is acquired, the quantities of the elements of the mixture are detailed, and the results of three samples and the average obtained are disclosed.
Thermal stability and some thermodynamics analysis of heat treated quaternary CuAlNiTa shape memory alloy
Authors: Kök Mediha , Qader Ibrahim Nazem , Mohammed Safar Saeed , Öner Ecem , Dağdelen Fethi , Aydogdu Yildirim
Published: November 2019

This study presents the heat treatment effect on a quaternary Cu79Al13Ni4Ta4(wt%) shape memory alloy. The induction technique was used for melting the alloy and then four pieces of the alloy were heat-treated at (673 K, 873 K, 1073 K, and 1273 K) for one hour. Some physical parameters were characterized using DSC, XRD, and SEM-EDX. The as-cast and heat-treated samples were studied in terms of phase transformation temperatures, enthalpy change, entropy change, Gibbs free energy, and elastic energy. The transformation temperature was increased by applying heat treatment. Martensitic phase transformation at heat treatment temperature of 1273 K was not observed. Besides, after rising heat treatment temperature, some new phases such asϒ1′andβ1′were specified in XRD patterns and SEM images. Generally, for heat-treated samples, the transformation temperature remains almost constant after the 3rd cycle. However, the thermal stability of the as-cast alloy was not affected through thermal cycling.
The coding and non-coding transcriptional landscape of subependymal giant cell astrocytomas
Authors: Bongaarts Anika , van Scheppingen Jackelien , Korotkov Anatoly , Mijnsbergen Caroline , Anink Jasper J , Jansen Floor E , Spliet Wim G M , den Dunnen Wilfred F A , Gruber Victoria E , Scholl Theresa , Samueli Sharon , Hainfellner Johannes A , Feucht Martha , Kotulska Katarzyna , Jozwiak Sergiusz , Grajkowska Wieslawa , Buccoliero Anna Maria , Caporalini Chiara , Giordano Flavio , Genitori Lorenzo , Coras Roland , Blümcke Ingmar , Krsek Pavel , Zamecnik Josef , Meijer Lisethe , Scicluna Brendon P , Schouten-van Meeteren Antoinette Y N , Mühlebner Angelika , Mills James D , Aronica Eleonora
Published: November 2019

Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited neurocutaneous disorder caused by inactivating mutations in TSC1 or TSC2, key regulators of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. In the CNS, TSC is characterized by cortical tubers, subependymal nodules and subependymal giant cell astrocytomas (SEGAs). SEGAs may lead to impaired circulation of CSF resulting in hydrocephalus and raised intracranial pressure in patients with TSC. Currently, surgical resection and mTORC1 inhibitors are the recommended treatment options for patients with SEGA. In the present study, high-throughput RNA-sequencing (SEGAs n = 19, periventricular control n = 8) was used in combination with computational approaches to unravel the complexity of SEGA development. We identified 9400 mRNAs and 94 microRNAs differentially expressed in SEGAs compared to control tissue. The SEGA transcriptome profile was enriched for the mitogen-activated protein kinase (MAPK) pathway, a major regulator of cell proliferation and survival. Analysis at the protein level confirmed that extracellular signal-regulated kinase (ERK) is activated in SEGAs. Subsequently, the inhibition of ERK independently of mTORC1 blockade decreased efficiently the proliferation of primary patient-derived SEGA cultures. Furthermore, we found that LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5 were overexpressed at both gene and protein levels in SEGA compared to control tissue. Taken together LAMTOR1–5 can form a complex, known as the ‘Ragulator’ complex, which is known to activate both mTORC1 and MAPK/ERK pathways. Overall, this study shows that the MAPK/ERK pathway could be used as a target for treatment independent of, or in combination with mTORC1 inhibitors for TSC patients. Moreover, our study provides initial evidence of a possible link between the constitutive activated mTORC1 pathway and a secondary driver pathway of tumour growth.
Spatial distribution of interictal spikes fluctuates over time and localizes seizure onset
Authors: Conrad Erin C , Tomlinson Samuel B , Wong Jeremy N , Oechsel Kelly F , Shinohara Russell T , Litt Brian , Davis Kathryn A , Marsh Eric D
Published: November 2019

The location of interictal spikes is used to aid surgical planning in patients with medically refractory epilepsy; however, their spatial and temporal dynamics are poorly understood. In this study, we analysed the spatial distribution of interictal spikes over time in 20 adult and paediatric patients (12 females, mean age = 34.5 years, range = 5–58) who underwent intracranial EEG evaluation for epilepsy surgery. Interictal spikes were detected in the 24 h surrounding each seizure and spikes were clustered based on spatial location. The temporal dynamics of spike spatial distribution were calculated for each patient and the effects of sleep and seizures on these dynamics were evaluated. Finally, spike location was assessed in relation to seizure onset location. We found that spike spatial distribution fluctuated significantly over time in 14/20 patients (with a significant aggregate effect across patients, Fisher’s method: P < 0.001). A median of 12 sequential hours were required to capture 80% of the variability in spike spatial distribution. Sleep and postictal state affected the spike spatial distribution in 8/20 and 4/20 patients, respectively, with a significant aggregate effect (Fisher’s method: P < 0.001 for each). There was no evidence of pre-ictal change in the spike spatial distribution for any patient or in aggregate (Fisher’s method: P = 0.99). The electrode with the highest spike frequency and the electrode with the largest area of downstream spike propagation both localized the seizure onset zone better than predicted by chance (Wilcoxon signed-rank test: P = 0.005 and P = 0.002, respectively). In conclusion, spikes localize seizure onset. However, temporal fluctuations in spike spatial distribution, particularly in relation to sleep and post-ictal state, can confound localization. An adequate duration of intracranial recording—ideally at least 12 sequential hours—capturing both sleep and wakefulness should be obtained to sufficiently sample the interictal network.
Imagining the Perfect Asian Woman Through Hate: Michelle Phan, Anti-Phandom, and Asian Diasporic Beauty Cultures
Authors: Tran Tony
Published: November 2019

This article examines the predominately Asian American “Anti-Phandom” community on GuruGossiper.com to explore how anti-fans of YouTube star Michelle Phan engage with ideologies of beauty cultures within Asian diasporic contexts. For many, Anti-Phandom provides an online space where personal concerns about female Asian beauty standards can be negotiated through Michelle Phan. Within these conversations, I argue Anti-Phans display forms of resistance to Phan's postfeminist forms of female empowerment on racial and ethnic terms. However, these counters to Phan's notions of beauty also produce a rubric of the beautiful Asian woman which renders difference as ugly, creating idealized definitions of racial beauty and Asian/American cultures based on essentialized categories that police diasporic women.
Clinical Characteristics of Active Tuberculosis Diagnosed After Starting Treatment for Latent Tuberculosis Infection
Authors: Flynn Andrew G , Aiona Kaylynn , Haas Michelle K , Reves Randall , Belknap Robert
Published: November 2019

Although rare, subclinical tuberculosis disease can be missed during evaluations for latent tuberculosis infection, and can manifest with symptoms during latent tuberculosis treatment. Among over 8000 patients treated for latent tuberculosis we found no evidence of acquired drug resistance, underscoring the safety of rifampin monotherapy for latent tuberculosis.
Lipidomics links oxidized phosphatidylcholines and coronary arteritis in Kawasaki disease
Authors: Nakashima Yasutaka , Sakai Yasunari , Mizuno Yumi , Furuno Kenji , Hirono Keiichi , Takatsuki Shinichi , Suzuki Hiroyuki , Onouchi Yoshihiro , Kobayashi Tohru , Tanabe Kazuhiro , Hamase Kenji , Miyamoto Tomofumi , Aoyagi Ryohei , Arita Makoto , Yamamura Kenichiro , Tanaka Tamami , Nishio Hisanori , Takada Hidetoshi , Ohga Shouichi , Hara Toshiro
Published: November 2019

Aims

Coronary arteritis is a life-threatening complication that may arise in the acute stage of Kawasaki disease (KD), the leading cause of systemic vasculitis in childhood. Various microorganisms and molecular pathogens have been reported to cause KD. However, little is known about the key molecules that contribute to the development of coronary arteritis in KD.

Methods and results

To identify causative molecules for coronary arteritis in KD, we prospectively recruited 105 patients with KD and 65 disease controls in four different parts of Japan from 2015 to 2018. During this period, we conducted lipidomics analyses of their sera using liquid chromatography–mass spectrometry (LC-MS). The comprehensive LC-MS system detected a total of 27 776 molecules harbouring the unique retention time and m/z values. In the first cohort of 57 KD patients, we found that a fraction of these molecules showed enrichment patterns that varied with the sampling region and season. Among them, 28 molecules were recurrently identified in KD patients but not in controls. The second and third cohorts of 48 more patients with KD revealed that these molecules were correlated with inflammatory markers (leucocyte counts and C-reactive proteins) in the acute stage. Notably, two of these molecules (m/z values: 822.55 and 834.59) were significantly associated with the development of coronary arteritis in the acute stage of KD. Their fragmentation patterns in the tandem MS/MS analysis were consistent with those of oxidized phosphatidylcholines (PCs). Further LC-MS/MS analysis supported the concept that reactive oxygen species caused the non-selective oxidization of PCs in KD patients. In addition, the concentrations of LOX-1 ligand containing apolipoprotein B in the plasma of KD patients were significantly higher than in controls.

Conclusion

These data suggest that inflammatory signals activated by oxidized phospholipids are involved in the pathogenesis of coronary arteritis in KD. Because the present study recruited only Japanese patients, further examinations are required to determine whether oxidized PCs might be useful biomarkers for the development of coronary arteritis in broad populations of KD.