bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of ionic liquid additives on temperature and pressure fluctuations during water flow boiling in microchannels
Authors: Sachi S , Zaitsev D V , Raj R
Published: December 2020

Overheating of high-performance electronic devices is undesired for long-term reliability. In this regard, two-phase microchannel heat sinks promise high heat dissipation within small temperature budgets using the latent heat of vaporization of the boiling fluid. However, geometrical confinement induces thermofluidic fluctuations and prohibits the use of two-phase microchannel heat sinks in practical applications. Here we for the first-time report flow boiling experiments with surface-active ionic liquid (SAIL) as an additive in water. This concept is inspired by our results of pool boiling wherein bubble coalescence was avoided with SAIL. In comparison to the water where fluctuations were apparent in the slug flow regime, temperature and pressure fluctuations were nearly mitigated up to the heat flux of 700 kW/m2 with an ionic liquid solution. The suppression of instabilities is attributed to the delay in the formation of a big vapor bubble at the inlet of microchannels due to the non-coalescing nature of bubbles formed with the SAIL solution.
The effect of air relative humidity on the intensity of evaporating of water–ethanol droplets
Authors: Sterlyagov A N , Nizovtsev M I , Borodulin V Yu , Letushko V N
Published: December 2020

The results of experimental studies of the evaporation of the water-ethanol droplets with various concentrations of ethanol suspended on a thread are presented. Using high-speed microphotography, we studied the dynamics of changes in the size of evaporating droplets at various relative humidity of the surrounding air. As a result of experiments, it was found that the relative humidity of the surrounding air had a significant effect on the process of droplet evaporation. For all the considered concentrations of ethanol, it was found that the higher the concentration, the shorter the evaporation time of the droplets. Generalization of the experimental data on the evaporation time of the water-ethanol droplets of the corresponding concentration of ethanol at a relative humidity of 95% was carried out.
Possibilities of heat pulse probing method for determining the phase diagram of partially-miscible liquid mixtures
Authors: Volosnikov D V , Povolotskiy I I
Published: December 2020

In the course of this research, the liquid-liquid equilibrium line for binary solutions characterized by the upper critical solution temperature was developed by the traditional method of visual observation and the method of heat pulse probing. The objects of study were solutions of perfluoromethylcyclohexan/hexene-1 and perfluorodimethylcyclohexan/hexene-1. Heat pulse probing mode was found, which allows us to recognize the approaching to the temperature of liquid-liquid phase separation. The possibility of pulse technique with a characteristic time of several milliseconds to determine the phase state and estimate the actual concentration of solutions in opaque vessels was revealed.
Investigation of characteristics of a pneumatic nozzle as applied to coal-water fuel spraying
Authors: Shadrin E Yu , Anufriev I S , Kopyev E P , Maltsev L I , Sharypov O V
Published: December 2020

A gas-droplet flow, formed by spraying liquid with a pneumatic nozzle was studied in a wide range of parameters. Information on the distribution of particle sizes was obtained using the method of shadow photography. High-speed visualization of the flow was performed. The nozzle operating regimes of a steady gas-droplet flow generation were identified.
Analysis of the effectiveness of the systems for providing thermal conditions of the local working areas based on the gas infrared emitters
Authors: Voloshko I V , Kuznetsov G V , Maksimov V I , Nagornova T A
Published: December 2020

One of the urgent tasks in recent years is to reduce the cost of thermal energy to ensure the thermal regime of the local working areas in the production facilities. For these purposes, the gas infrared emitters (GIE) are increasingly used, but due to the lack of an informative base that provides the regulated thermal regime of the big-sized workrooms, their implementation is constrained. The article presents the results of the experimental and theoretical studies carried out to assess the efficiency of using such systems. The measurements of the temperatures of the floor surface at the characteristic points were carried out during the operation of the emitter of average power. The article presents the results of mathematical modeling of heat transfer in the surface layer of the floor which receives the heat flux from the GIE.
Gasification and oxidation of thiophene in supercritical water fluids
Authors: Vostrikov A A , Psarov S A , Dubov D Yu , Sokol M Ya , Shishkin A V , Fedyaeva O N
Published: December 2020

The paper deals with the gasification of thiophene in supercritical water (SCW) at a molar ratio of H2O:C4H4S = 1:0.107, a temperature of 873–1023 K, a pressure of 30 MPa, and a holding time of 150–600 s in a batch reactor. The gases of CO2, CO, H2, CH4, and H2S were detected in the composition of SCW gasification products. The maximum degree of thiophene gasification (>99.9%) was achieved at 1023 K and 600 s. The conversion of thiophene in SCW is described by a pseudo-first-order macro kinetic equation. It was revealed that the oxidation of thiophene in H2O/O2 mixture at uniform heating of the reactor (1 K·min−1) begins at T ≈ 400 K. The lack of O2 results in the formation of soot. It is shown that the formation of sulfuric acid during the oxidation of thiophene in the H2O/O2 mixture causes corrosion of stainless steel.
Simulating glow discharge positive column parameters in neon
Authors: Demin N A , Fedoseev A V
Published: December 2020

The nonlocal self-consistent model for the low temperature plasma parameters in a glow discharge positive column is presented. The model implies relaxation method for the solving of the nonlocal Boltzmann equation for electron energy distribution function, continuity equation for ions distribution and Poisson equation for radial electric field. Calculations are provided for a cylindrical discharge tube used in the Plasma Kristall-4 experiments for neon as a plasma forming gas for the gas pressures of 30-70 Pa and discharge currents of 0.5-2.5 mA. Axial electric field strength, electron temperature and electron density are calculated as functions of the discharge current and the gas pressure. The results are in good agreement with the data provided by other authors.
Partial oxidation of light alkanes in microchannel
Authors: Dimov S V , Gasenko O A
Published: December 2020

In this work, we conducted an experimental study of partial oxidation of fuel gas, consisting of a mixture of light C1-C4 alkanes, in an annular microreactor with a catalyst deposited on the inner wall of the channel with a carbon/oxygen ratio equal to one. The experiments were carried out at different contact times in the temperature range of the reactor of 450-750°C.
Numerical optimization of plasma generation in a microwave resonant cavity
Authors: Hrebtov M Yu , Bobrov M S
Published: December 2020

The paper presents a numerical simulation of the hydrogen plasma generation process in a cylindrical microwave resonant cavity at moderate pressures (10 Torr). We introduce a modification to the chamber by placing several spherical dielectrics with a high permittivity at the central axis. The radii of the spheres are chosen for the Mie resonance for microwave radiation (at 2.45GHz frequency) to occur. For a dimer configuration where two spheres are placed closely together, a maximum of the electrical field magnitude is located in the gap between the spheres where the intense discharge occurs. Positioning the spheres in different spots of the chamber allows controlling the process of the microwave plasma generation. Such modification is promising for a stable discharge initiation and for preventing the discharge breaking in the microwave cavity.
Thermocapillary waves formation at the interface of hydrocarbons and graphene-like nanofluids
Authors: Paharukov Y V , Shabiev F K , Safargaliev R F , Ezdin B S , Zarvin A E , Kalyada V V
Published: December 2020

The paper presents the study of supramolecular structuring forming a transition region at the hydrocarbon – nanofluid interface resulting from synergistic effect by the interaction of multilayer graphene planar nanoparticles and silicon carbide nanoparticles covered with graphene layers (Core-shell). During the film formation on the interphase, filamentous formations were obtained, which resulted from interaction with thermocapillary waves. It was found that the structure of the filamentous formation was influenced by the composition and concentration of nanofluids.
Transport processes in Newtonin and non-Newotonian fluids and fluctuation-dissipation theorems
Authors: Rudyak V Ya
Published: December 2020

The subject of this paper is molecular modelling of the transport processes in liquids including nanofluids. The weak and strong nonequilibrium processes are considered. In the first case, the corresponding fluctuation-dissipation theorems are formulated. These theorems determine the relation between the dissipative processes and equilibrium thermal fluctuations of the mass, momentum, and energy in the molecular system. Two different formulations of these theorem are discussed in detail. Various systems are considered: molecular liquids, nanofluids, turbulent liquids, fluids in confined conditions, and microviscosity in biomembranes. In the last part the nonlinear transport processes and rheology of the non-Newtonian fluids are discussed.
Sn filament formation under arc discharge sputtering of SnO2/C electrode
Authors: Zaikovskii A V
Published: December 2020

As a result of electric arc sputtering of a composite SnO2/C electrode in a rarefied helium medium, the formation of tin fibers reaching a length of more than 20 μm was discovered. The length of the formed fibers depends on the distance from the arc discharge to the area of deposition on a graphite substrate. The formation of tin fibers is influenced by such factors as the temperature of the gaseous medium and the partial pressure of tin vapor.
Density and thermal expansion of silver in the solid and liquid states
Authors: Abdullaev R N , Khairulin R A , Stankus S V
Published: December 2020

Density and thermal expansion of pure silver are investigated using a gamma-ray attenuation technique in the temperature range of 293–1631 K of solid and liquid states. The relative density change of silver during the solid–melt phase transition is directly measured. The approximation dependences for the density are constructed and the data of this work are compared with the results of other authors. Tables of temperature dependences of the volumetric properties of silver are developed over the entire measurement interval and their errors are estimated.
Thermophysical properties of ML5 casting magnesium alloy
Authors: Agazhanov A Sh , Samoshkin D A , Kozlovskii Yu M , Stankus S V
Published: December 2020

In the present work thermal conductivity, thermal diffusivity, heat capacity, melting enthalpy, and linear thermal expansion coefficient of ML5 casting magnesium alloy were investigated in the temperature range of 298–670…925 K. The measurements were performed using laser flash method, dilatometric method and differential scanning calorimetry on the samples made from the one initial material. Using the obtained data, the temperature dependence of the thermal conductivity was determined. For all studied properties the approximation equations were obtained which can be used for various scientific and practical applications.
Phonon density of states and thermodynamic properties of La2(C11H19O2)6
Authors: Musikhin A E , Bespyatov M A
Published: December 2020

Based on the low-temperature heat capacity a set of properties of dimeric lanthanum dipivaloylmethanate were obtained. The phonon density of states was calculated, and characteristic temperatures related to the basic moments of the density of states were obtained. The molar thermodynamic functions at constant volume (heat capacity, entropy, internal energy increment, and Helmholtz energy) in the temperature range of 0–455 K were calculated. The molar zero-point energy and total internal energy were calculated.
Thermal conductivity of R-32/R-125 (40/60 wt. %) mixture in the vapor phase
Authors: Raschektaeva E P , Stankus S V , Verba O I
Published: December 2020

The gaseous thermal conductivity of binary mixture of R-32/R-125 (40/60) was measured with a coaxial cylinders method in the temperature range of 305–426 K and the pressure range of 0.1–1.8 MPa. The thermal conductivity as a function of pressure and temperature was considered. The correlations for thermal conductivity on dew line and in ideal gas state are presented.
Numerical study of non-stationary radiation-conductive ice heat transfer taking into account radiation scattering
Authors: Sleptsov S D , Savvinova N A , Grishin M A
Published: December 2020

A numerical study of the formation of the temperature field and the melting rate of a layer of ice scattering radiation vertically located on an opaque substrate during radiation heating has been carried out. To solve the radiation part of the problem, a modified method of average fluxes is used, taking into account the volume absorption and scattering of radiation into the medium, as well as the selective nature of the radiation source. Anisotropic scattering radiation is taken into account by the method of expanding the scattering indicatrix in a series according to Legendre polynomials. The effect of the spectral volumetric properties of ice on the melting and temperature increase of the non-irradiated side is presented. Comparison of calculation results with experimental data demonstrates satisfactory agreement. The proposed method for taking into account anisotropic scattering does not show any significant difference from isotropic scattering.
Evolution of non-stationary boundary layers in a vertical liquid layer in the regime of conjugated natural convective heat exchange
Authors: Mitin K A , Mitina A V , Berdnikov V S
Published: December 2020

The evolution of non-stationary boundary layers under monotonous heating to a given temperature of the outer surface of one of the walls of a vertical liquid layer is numerically studied. The finite element method is used to solve a system of equations for unsteady thermogravitation convection in the Boussinesq approximation in terms of vortex, stream function, and temperature. The process of formation of non-stationary boundary layers on the heated wall is studied depending on the layer height. In a two-dimensional conjugate problem statement, distributions of non-stationary temperature and velocity fields in a liquid with a Prandtl number of 10 are obtained. Distributions of non-stationary temperature fields in mirror glass walls and temperature gradients on the walls are obtained as well. The calculations are made for the Rayleigh number equal to 106.
Numerical simulation of non-Newtonian hydrodynamics in an annular channel with tool joint
Authors: Orlik E , Bocharov O , Gavrilov A
Published: December 2020

The paper presents the simulations of the local and integral characteristics of an annular flow with tool joints, depending on problem parameters. The structure of the flow in the vicinity of the coupling, in the areas of stagnant and reverse flow, is studied in detail. The characteristic length of separation and stabilization zones, i.e. the distance behind the joint where the flow reaches steady-state again is investigated. The sizes of pipes and tool joints in the study match those used while drilling. The numerical modelling is performed in 3D steady-state formulation for both laminar and turbulent regimes using original in-house software.
Thermal Conductivity of Graphene and Its Applications on Heat Spreading Materials
Authors: Li Yunhui
Published: December 2020

Graphene consists of a single layer of carbon atoms arranged in two-dimensional hexagonal lattice. This research set up model of graphene with heat source and sinks to visualize the movement of carbon atoms. Moreover, molecular dynamics simulations were tools to study the thermal conductivity of graphene and other properties of a material. The result shows that the thermal conductivity of graphene in the room temperature is relatively high among the existing materials. Various possibilities for its application will be briefly discussed, mainly focused on heat spreading materials. At last, there will be a discussion about graphene’s future development.
Research on the Application of Agricultural Engineering Technology in Agricultural Modernization
Authors: Zhang Heyi
Published: December 2020

In recent years, with the rapid improvement of China’s science and technology level, China’s agricultural engineering technology has also made considerable progress. The development of agricultural engineering technology provides an important technical foundation for the realization of agricultural modernization, especially in the effective use of agricultural resources, the improvement of agricultural labor productivity, and the transformation of agricultural production and operation methods. Therefore, we must increase the promotion and application of agricultural engineering technology in various agricultural production and operation activities. This will help promote the gradual development of China’s agricultural production in the direction of mechanization, automation, informationization and intelligence, so as to fully realize the modernization of China’s agriculture.
Research on the Design of Cultural and Creative Products in Southern Fujian Based on Narrative Design Methods
Authors: Zhou Xiaoping , Lian Xiaobo , Guo Huiting
Published: December 2020

Narrative design method is an important form of cultural creative design. An important manifestation of the combination of traditional culture and modern culture is cultural creative products. Southern Fujian cultural elements are unique and have an important position in Chinese culture. Combining southern Fujian cultural elements with modernity and carrying out cultural and creative design will help promote the innovative development of traditional Chinese culture. Based on this, this article analyzes Minnan cultural and creative products.
Self-Assembly of Janus Type Amphiphilic Dendrimers from Dissipative Particle Dynamics Simulation
Authors: Yan Wenyuan
Published: December 2020

The self-assembly of Janus type amphiphilic dendrimers has been studied extensively through experiments and computer simulations, while most of the simulations assume that Janus molecules are connected by covalent bonds, disregarding the noncovalent interaction which evokes the particular dynamic self-assembly regulation. This paper investigates the dynamic self-assembly behavior of Janus type amphiphilic dendrimers through the dissipative particle dynamics (DPD) method. A series of coarse-grained models of Janus type amphiphilic dendrimers with different hydrophobic-hydrophilic ratios were constructed to simulate the static self-assembly, and then the dynamic self-assembly was carried out through introducing a chemical bonding reaction to simulate the non-covalent interaction between the two different parts of Janus type dendrimers. The control of reaction rate was accomplished by modifying the reaction probability to adjust the dynamic self-assembly process. The results indicate that the introduction of non-covalent interaction changes the self-assembly behavior of some models and generates different dynamic self-assembly structures. It can also be deduced that the reaction rate exerts influence on the structure of dynamic self-assembly.
Dynamic Analysis and Structure Improvement of Timing Chain of an Engine
Authors: Chen Yajuan
Published: December 2020

Based on the dynamic theory, taking the timing chain system of an engine as the research object, the dynamic characteristics of the contact force between the chain and the components, the swing of the chain and the friction work at idle speed of the chain are analyzed respectively. And the influence of the structural design parameters on the abnormal noise of the engine is obtained. Thus, the optimization scheme of the timing chain system is proposed according to the analysis results.
Distribution of Inclusions in 18CrNiMo7-6 Steel Billet and Its Relationship with Inclusion Compositions
Authors: Wang N. , Fang C.F. , Zhao L. , Huang K. , Wang R. , Wang J.M. , Hao H.
Published: December 2020

The 18CrNiMo7-6 steel billet was prepared by the process of EBT→LF→VD→die casting and forging. The position distribution, composition, type and cause of inclusions in the billet were statistically analysed by ASPEX and scanning electron microscopy. The results show that there are obvious distribution differences of inclusions in different parts of the steel billet. In contrast, the number density of inclusions in the billet corresponding to the ingot riser and the negative segregation zone is higher; the average composition point of the inclusions in the slow cooling zone tends to be distributed in the higher temperature zone of the MgO-Al2O3-CaO ternary phase diagram.
Effect of heat treatment on microstructure, hardness and electrical conductivity of as-extruded ZK80 Mg alloy
Authors: Cao Fenghong , Qin Zhaohui , Chen Chang , Xu Yaohui , Huang Lanxiang
Published: December 2020

The microstructure, hardness and electrical conductivity of as-extruded ZK80 Mg alloy were tested and analyzed by means of microscope, XRD, electrical conductivity and Rockwell hardness tester. The results show that: as-extruded ZK80 Mg alloy has good aging strengthening effect, the change trend of hardness and electrical conductivity of the alloy is the same, that is, the hardness and electrical conductivity of that alloy show a strong linear correlation, with the extension of holding time, the hardness and conductivity increase in an oscillatory manner, and then decrease after reaching the peak value. The relationship between hardness and conductivity is g = 1.06418h-52.29795, and the experimental fitting effect is good.
Crack Corrosion Simulation of H62 Copper Alloy Coating Under Damage Condition
Authors: Tong Zhang , Wentao NIU , Qing Dong , Cheng Xia
Published: December 2020

Objective To study the crevice corrosion under the condition of damaged coating. Methods The simulation was carried out by using COMSOL software. The influence of the distance between the damage zone (W) and the gap width (H) of the damage zone was discussed. As a result, the corrosion enters the stable corrosion stage after a very short initial stage, and the current is much longer than the stable stage in the initial stage. The electrolyte potential and the electrode potential are completely different in the initial and stable stages; the anode reaction occurs uniformly in the damaged area, and the cathode reaction focuses on the crack mouth in the stable stage; the increase of W and H is aggravated by corrosion, but when W is greater than 0.7mm, the effect is very weak and can be considered to be stable. Conclusion The crevice corrosion under the condition of coating damage is the corrosion controlled by the cathode oxygen reduction reaction. The oxygen is quickly consumed in the initial stage and cannot be replenished. The cathodic reaction is mainly concentrated in the crack mouth. The change of W at small time will affect the corrosion. The increase in H will exacerbate corrosion.
Analysis on Evaluation Method for Support Equipment System Effectiveness
Authors: Yue Deng , Chao Hou
Published: December 2020

In order to study the applicability of evaluation method in the process of service support equipment effectiveness evaluation, this paper selects several kinds of evaluation method which are widely used in the field of equipment effectiveness evaluation, summarizes their basic ideas and general steps, analyzes the application of each evaluation method in the process of service support equipment effectiveness evaluation, and provides a theoretical reference for the practical application of logistics support equipment system effectiveness evaluation method.
H2Ti3O7 Nanorods Synthesized H Cation-exchange in Na2Ti3O7 for Stable Sodium Storage
Authors: Li Cheng , Jiang Ying , Li Zehua , Zhang Yixin , Xie Man
Published: December 2020

To overcome poor interfacial stability and slow ion transport rate of Na2Ti3O7, H2Ti3O7 nanorods are synthesized by acidification of Na2Ti3O7 with low concentration of strong acid. The dominated pseudo-capacitive behavior significantly improved rate capability with fast electron and ion storage kinetics. When used as anode for sodium-ion batteries, H2Ti3O7 delivers a stable specific capacity of 103.5 mAh g-1 after 500 cycles with a capacity retention rate of 49.3%, and high rate performance (70.5 mAh g-1 at 2 A g-1).
Dynamic analysis of main transmission mechanism of high-speed cold heading machine based on rigid-flexible coupling model
Authors: Teng Xinyi , Li Guoping , Zhang Xiangfang , Yao Yi
Published: December 2020

In the research of high speed cold heading machine, only single part is studied. The interaction between the components of the main drive mechanism is rarely studied. The motion of the main transmission mechanism of the cold heading machine was analysed. The interaction between the components of the main transmission mechanism was studied. This article adopts the theory of multi-body system dynamics. The rigid-flexible coupling model of the main transmission mechanism was established. The dynamics and kinematics simulation of the main transmission mechanism was carried out. The motion curve and stress of the rigid-flexible coupling model are obtained. Compared with the rigid model, the rationality of the rigid flexible coupling model was demonstrated. It provided a reference for further fatigue analysis and optimization of the main transmission mechanism.
Sustainable design of the GUST small wind turbine
Authors: Zawadzki Karol , Baszczyńska Anna , Stępień Małgorzata , Fliszewska Angela , Molenda Szymon , Pisarski Marcin
Published: December 2020

One of the increasingly important criteria, when constructing a Small Wind Turbine (SWT), is its sustainable design. It means constructing the SWT in such a way that it can provide a cheap, easy and safe access to clean energy at a specific location for predicted number of consumers. This paper highlights three issues. First, benefits from the application of the rapid prototyping technology are discussed. 3D printers can be used as a durable and relatively cheap means of SWT components production. Also, the possibility of using recycled plastic for 3D-printed components is of big importance. Secondly, the modular construction of the small wind turbine is outlined. This facilitates the product versatility, proneness to adjustments and ease of maintenance. Last but not least, the production costs for individual units as well as multi-unit production are reviewed to show the financial benefits of SWTs and the payback of such investments over the years. The article concludes with a set of recommendations for wind turbine design, conformal with the suggestions of the UN Sustainability Report and Sustainable Development Goal 7.1. The utilization of described concepts is demonstrated basing on the GUST 1.6 m diameter horizontal axis SWT.
Loading on the carrying structure of a flat wagon when transporting firing military equipment
Authors: Fomin O , Vatulia G , Lovska A
Published: December 2020

The study deals with research through mathematic modeling of the dynamic loading on the carrying structure of a flat wagon in transportation of military equipment conducting fire. A 13-401 flat wagon loaded with a tank with combat load of 55 tons was taken as the prototype. The mathematical model was solved in MathCad software. It was established that the maximum acceleration on the carrying structure of a flat wagon in the horizontal plane was about 40 m/sec2, and in the vertical plane – about 10 m/sec2. The values obtained were considered in strength calculation for a flat wagon. The calculation was made using the finite element method in CosmosWorks software. It was established that the maximum equivalent stresses in the carrying structure of a flat wagon exceeded the admissible values twice. The results of the study will encourage engineers to design carrying structures of flat wagons intended for transporting military equipment firing in motion
Study of the operation of taxi cars in an emergency situation
Authors: Grozev Dimitar , Georgiev Ivan , Georgiev Dimitar
Published: December 2020

This paper examines the transportation work of taxi companies operating in the city of Ruse in an emergency situation caused by the COVID-19 epidemic when the number of requests for taxis decreased by 60%, about 30% of drivers stopped working due to reduced workload. The aim of the present study is to identify changes in their work intensity. The taxi operating system is modelled as a queuing system with failures with non-stationary incoming flow of requests and a variable number of service channels. After collecting and processing statistical information about the received requests, the incoming flow is modelled as a periodic nonlinear function. The main parameters of the study are: density of failures, average number of taxi cars occupied per day and intensity of serviced requests. The object of the study is a full working day of 24 working hours, taking into account the reduced intensity of transportation work. Even at the highest peaks the load coefficient is below 0.1, which means that in the intervals with the highest load, the service occupancy is below 10% of those working at the moment. In the interval from 0:00 h to 7:00 h a load factor slightly above 0.04 is observed. An application has been created in the environment of MATLAB.
Experimental study of the flame propagation of gaseous fuel based mixture using optical visualisation
Authors: Hristov R , Stefanov S , Dimitrov R
Published: December 2020

At this article presents experimental investigations carried out to determine the flame kernel propagation of gaseous fuel-air mixture under spark-ignition engine-like conditions. Various combustion processes taking place in an experimental combustion chamber are discussed. Consecutive shots of the development of the fuel flame front in a constant volume combustion chamber under different initial conditions are presented. Direct visual recording of an image of the combustion process is performed or Schlieren photography techniques are used. Modern types of spark plugs with different gaps in the entire price range are examined. CNG and LPG are used as gaseous fuels, since they are the main alternative fuels used in internal combustion engines for vehicles. Some of the results, such as pressure, maximum pressure and electric spark indicators, are shown as graphics. To calculate the speed of the flame propagation, specialised software processing the areas of the individual photos was used. The conclusions emphasize the results of relative air/fuel ratio, most favourable type of spark plugs and their gaps and location in the combustion chamber.
Development of a method for automotive engine control unit modification for achieving different operating modes using software correction
Authors: Nikolov N , Gotseva D
Published: December 2020

This article describes the development of a method for automotive fuel injection engine control unit (ECU) modification for aimed at achieving operating modes such as Economy (ECO) and Sport using software alteration. The article researches the offered pattern and demonstrates the experimental staging. An automotive ECU, microcontroller and software are used for the experimental stage. The ECO mode is used to achieve fuel economy and the Sport mode are used to achieve more engine power. The microprocessor used to switch between ECU modes is PIC18F14k22 and the ROM flash memory which stores the firmware for the two modes is AM29F400BB. The ECU used in the research is Sagem s2000. In the article, both the hardware and the software modifications are described as well as the experimental results.
Experimental investigation of the motorcycle braking properties when riding on different road surfaces
Authors: Barta Dalibor , Dižo Ján , Blatnický Miroslav , Vaňko Jozef
Published: December 2020

The presence of motorcycles on the roads significantly affects road traffic and its safety. Avoidance manoeuvres requiring braking and acceleration are closely linked to motorcycle riding. This paper points out the influence of the type of motorcycle and the type of its tyres on the braking distance and the stability of the motorcycle. Two types of motorcycles are compared - road and off-road when riding on two different surfaces and also three ways of braking - only with the front brake, only with the rear brake and with both brakes. The work analyses the problem of braking and stability of a motorcycle. When a brake lever is suddenly pushed, the stability of the motorcycle can be lost. Authors have analysed, compared and evaluated braking distances of motorcycles. Results of investigation activities have shown, that reaching of maximal safe and the shortest braking distance on the certain road surface needs to choose a proper type of motorcycle and a tyre.
Plasma concentrations resulting from continuous infusion of meropenem in a community-based outpatient program: A case series
Authors: Legg Amy , Halford Melanie , McCarthy Kate
Published: December 2020

Purpose

Traditionally meropenem has been considered too unstable in solution for continuous infusion. However, in the era of increasing antimicrobial resistance, use of meropenem is becoming more frequently required, and the ability to facilitate its administration via community-based programs would be beneficial. There are some reassuring data about meropenem stability in solution, but data about actual drug exposure in patients and subsequent clinical outcomes are lacking.

Here we present a case series of 4 patients at a single tertiary center who received meropenem via continuous infusion coordinated through an outpatient parenteral antimicrobial treatment (OPAT) program. We provide plasma drug concentrations achieved and report on the patients’ clinical progress. All patients achieved drug concentrations of at least 2 times the minimum inhibitory concentration (MIC) while receiving meropenem via continuous infusion and had resolution of their infectious complications. No adverse effects of meropenem continuous infusion were noted.

Conclusion

Meropenem continuous infusion along with therapeutic drug monitoring was used successfully in a community-based program. Due to interpatient pharmacokinetic variability, we consider meropenem concentration monitoring compulsory during continuous-infusion meropenem therapy.
Asymptomatic SARS-CoV-2 infection: is it all about being refractile to innate immune sensing of viral spare-parts?—Clues from exotic animal reservoirs
Authors: Shankar Esaki M , Che Karlhans F , Yong Yean K , Girija A S Smiline , Velu Vijayakumar , Ansari Abdul W , Larsson Marie
Published: December 2020

A vast proportion of coronavirus disease 2019 (COVID-19) individuals remain asymptomatic and can shed severe acute respiratory syndrome (SARS-CoV) type 2 virus to transmit the infection, which also explains the exponential increase in the number of COVID-19 cases globally. Furthermore, the rate of recovery from clinical COVID-19 in certain pockets of the globe is surprisingly high. Based on published reports and available literature, here, we speculated a few immunovirological mechanisms as to why a vast majority of individuals remain asymptomatic similar to exotic animal (bats and pangolins) reservoirs that remain refractile to disease development despite carrying a huge load of diverse insidious viral species, and whether such evolutionary advantage would unveil therapeutic strategies against COVID-19 infection in humans. Understanding the unique mechanisms that exotic animal species employ to achieve viral control, as well as inflammatory regulation, appears to hold key clues to the development of therapeutic versatility against COVID-19.
Social Media Communication and Loneliness Among Older Adults: The Mediating Roles of Social Support and Social Contact
Authors: Zhang Kunyu , Kim Kyungmin , Silverstein Nina M , Song Qian , Burr Jeffrey A
Published: December 2020

Background and Objectives

Social media communication offers a medium for helping older people stay socially and emotionally connected with others. This study investigated the association between social media communication with close social ties and loneliness among community-dwelling older adults. The study also examined the mediating roles of social support and social contact.

Research Design and Methods

Four waves of data from the Health and Retirement Study (2010/2012 and 2014/2016) were used to address the research questions (N = 7,524). A path model was estimated to examine the association between social media communication and older adults’ loneliness. We also examined whether the association between social media communication and loneliness was mediated by perceived social support from close social ties (children, other family members, and friends) and frequency of contact with social network members (phone, in-person contact, and writing letters/e-mail).

Results

The results showed that frequent social media communication was associated with lower levels of loneliness, adjusting for previous levels of loneliness. The relationship between social media communication and loneliness was mediated by perceived social support and social contact. Thus, social media communication was associated with higher levels of perceived social support and social contact, which were related to lower levels of loneliness among older adults.

Discussion and Implications

These findings suggested that social media communication may be considered an intervention to reduce loneliness among older people by increasing levels of social support and social contact.
Body Size and Cuticular Hydrocarbons as Larval Age Indicators in the Forensic Blow Fly,Chrysomya albiceps(Diptera: Calliphoridae)
Authors: Alotaibi Fayeza , Alkuriji Mohammed , AlReshaidan Salwa , Alajmi Reem , Metwally Dina M , Almutairi Bassam , Alorf Majed , Haddadi Rania , Ahmed Ashraf
Published: December 2020

Chrysomya albiceps (Wiedemann 1819) is one of the most important insects in forensic entomology. Its larval developmental and survival rates are influenced by nutritional resources, temperature, humidity, and geographical regions. The present study investigated the possibility of relying on body size and cuticular hydrocarbon composition as indicators for age estimation of the different larval instars of C. albiceps. Larvae were maintained in standardized laboratory conditions at different experimental temperatures. All larval instars (first, second, and third) were randomly collected for measuring their body sizes and for estimating their cuticular hydrocarbons at different rearing temperatures (30, 35, 40, and 45°C) using gas chromatography–mass spectrometry (GC–MS). Results indicated that the duration of larval stage was temperature dependent as it gradually decreased on increasing the rearing temperature (30, 35, and 40°C) except 45°C at which larval development was ceased. In contrary, larval body size, in terms of length, width, and weight, was temperature dependent as it gradually increased with larval development on increasing rearing temperature except at 45°C at which larval development was ceased. The GC–MS showed a significant difference in the extracted components of cuticular hydrocarbons between different larval instars reared in the same temperature and between the same larval instar that reared at different temperatures. Furthermore, the highest and lowest amounts of cuticular hydrocarbons were detected at 35 and 40°C, respectively. Overall, larval body size and cuticular hydrocarbon components were temperature dependent within the range 30–40°C, which may suggest them as possible reliable age indicators for estimating the postmortem interval in the field of medicolegal entomology.
Somatic Focal Copy Number Gains of Noncoding Regions of Receptor Tyrosine Kinase Genes in Treatment-Resistant Epilepsy
Authors: Vasudevaraja Varshini , Rodriguez Javier Hernaez , Pelorosso Cristiana , Zhu Kaicen , Buccoliero Anna Maria , Onozato Maristela , Mohamed Hussein , Serrano Jonathan , Tredwin Lily , Garonzi Marianna , Forcato Claudio , Zeck Briana , Ramaswami Sitharam , Stafford James , Faustin Arline , Friedman Daniel , Hidalgo Eveline Teresa , Zagzag David , Skok Jane , Heguy Adriana , Chiriboga Luis , Conti Valerio , Guerrini Renzo , Iafrate A John , Devinsky Orrin , Tsirigos Aristotelis , Golfinos John G , Snuderl Matija
Published: December 2020

Epilepsy is a heterogenous group of disorders defined by recurrent seizure activity due to abnormal synchronized activity of neurons. A growing number of epilepsy cases are believed to be caused by genetic factors and copy number variants (CNV) contribute to up to 5% of epilepsy cases. However, CNVs in epilepsy are usually large deletions or duplications involving multiple neurodevelopmental genes. In patients who underwent seizure focus resection for treatment-resistant epilepsy, whole genome DNA methylation profiling identified 3 main clusters of which one showed strong association with receptor tyrosine kinase (RTK) genes. We identified focal copy number gains involving epidermal growth factor receptor (EGFR) and PDGFRA loci. The dysplastic neurons of cases with amplifications showed marked overexpression of EGFR and PDGFRA, while glial and endothelial cells were negative. Targeted sequencing of regulatory regions and DNA methylation analysis revealed that only enhancer regions of EGFR and gene promoter of PDGFRA were amplified, while coding regions did not show copy number abnormalities or somatic mutations. Somatic focal copy number gains of noncoding regulatory represent a previously unrecognized genetic driver in epilepsy and a mechanism of abnormal activation of RTK genes. Upregulated RTKs provide a potential avenue for therapy in seizure disorders.
A 50-Year Retrospective of the Forest Productivity Cooperative in the Southeastern United States: Regionwide Trials
Authors: Carter David R , Allen H Lee , Fox Thomas R , Albaugh Timothy J , Rubilar Rafael A , Campoe Otávio C , Cook Rachel L
Published: December 2020

In 2019, the Forest Productivity Cooperative (FPC) celebrated its 50th anniversary. The mission of the FPC is and has been creating innovative solutions to enhance forest productivity and value through the sustainable management of site resources. This industry-government-university partnership has generated seminal research with sweeping implications for increasing productivity throughout the southeastern United States and Latin America. To commemorate this semicentennial, we highlighted some of the pivotal findings in the southeastern United States from the past 50 years derived from our large, regional experiments: regionwide trials.
The diversity of thrips (Insecta: Thysanoptera) on buffel grass (Cenchrus ciliaris) is markedly lower than on native grasses in an urban landscape
Authors: Palmer Christopher M , Mound Laurence A
Published: December 2020

Buffel grass (Cenchrus ciliaris) is a perennial tussock grass native to parts of Africa and southern Asia but is now distributed throughout much of mainland Australia. Corresponding with its presence in Australia has been an alteration of fire regimes and soil nutrients, and a reduction in floral diversity. We investigated whether buffel grass supported a less diverse community of thrips (order Thysanoptera) compared to the native grasses Cymbopogon ambiguus and Themeda triandra growing in Alice Springs, central Australia. The survey data showed that abundance was highest on buffel grass; however, the thrips community was almost entirely dominated by one species. The thrips communities on the native grasses were similar and markedly more diverse than that on buffel grass, both in terms of species richness and functional feeding groups. Flower feeders constituted the greatest proportion of thrips on all three grasses, but the native grasses also supported leaf feeders and predators. The results indicate that thrips are sensitive to vegetation change, and we suggest that active removal of buffel grass and replacement with local native grasses would help reverse the loss of biodiversity and normal ecological function in urban areas like Alice Springs. We also suggest that the order Thysanoptera is under-utilised in biodiversity research.
Introduction
Authors: Argenton Cédric , Geradin Damien , Stephan Andreas
Published: December 2020

This introductory chapter is a brief overview on cartels. It first defines what a cartel is in the modern sense and differentiates it from other forms of cooperation that do not typically apply to the European Union's (EU) competition rules. The chapter then considers the advantages and disadvantages of cartels. It describes a history in which cartels are tolerated and even encouraged, contrasting these instances with the modern view that horizontal cartel arrangements are generally very harmful to consumers and to markets. From there, the prevalence of cartels in modern economies is explored. Here, the chapter provides some model estimates for the prevalence of cartels, before discussing the broader implications of this study.
Cartel Detection
Authors: Argenton Cédric , Geradin Damien , Stephan Andreas
Published: December 2020

This chapter is concerned with cartel detection, through market monitoring, inspections, or well-designed leniency programs. It analyses three methods competition authorities regularly use to detect, and adduce evidence about, cartels. First, competition authorities can detect cartels by monitoring and screening markets. Second, competition authorities can conduct inspections at the business premises or private homes of cartel participants. Third, given the limitations of the first two methods, competition authorities can incentivize companies to report the cartels in which they may be involved by rewarding them for their cooperation. Pursuant to so-called leniency programmes, companies that choose to cooperate will, depending on the quality of the information provided and the time at which it is provided, benefit from full immunity from fines or significant fine reductions (partial immunity). Following in the footsteps of the US Department of Justice, the European Commission adopted a Leniency Notice in 1996, the application of which has allowed it to uncover a vast number of cartels.
Civil Damages
Authors: Argenton Cédric , Geradin Damien , Stephan Andreas
Published: December 2020

This chapter deals with private litigation. It begins with some discussion of the general issues surrounding private enforcement and an overview of the United States, where the level of private enforcement in cartel cases has historically far exceeded that of public cases. The chapter then provides a summary of the state of private enforcement in each of the EU's current twenty-eight Member States, before the EU Damages Directive was adopted. In this respect, it attempts to give a summary of national initiatives in the absence of an EU framework but excludes reforms made in response to, or in direct anticipation of, the EU Damages Directive. This background is important to understand the issues that shaped the Directive. Finally, the chapter discusses the thorny issue of damage estimation.