Speed Line Research Articles

Performance and flow evolution of windmilling utilizing a combination of semi-empirical speed and CFD models during mode transition of the wide-chord fan

With reductions in the pressure ratio of the fan and increases in bypass ratio of the turbofan in recent years, the engine windmilling and relight capability have attracted more and more attention in aviation safety. This paper proposes a combination of the speed model and CFD to examine the internal flow evolution of the wide-chord fan under the windmilling condition. Firstly, we establish a semi-empirical speed model for predicting the fan rotational speed of a high-bypass ratio turbofan at any flight Mach number and altitude based on the flow characteristics of a windmilling fan. The model can provide an initial windmilling airflow at the specified speed for subsequent CFD calculations to reduce the number of iterations. Then, a three-dimensional CFD model is proposed to obtain the operating boundary of the windmilling fan according to the direction of energy transfer between the fan and the airflow. The mechanisms of fan internal flow evolution and tip leakage flow when it operates at a constant speed line were analyzed. The results show that the work distribution profiles along the blade span exhibited self-similarity. The fan blade operated in both spanwise and chordwise mixed configuration. The flow moved gradually from compressor-like regions near the hub to turbine-like regions near the shroud, where the stirrer mode was the transitional stage between them during windmilling. When the rotor entered the windmilling, it operated at a significantly off-design angle of attack, that caused a large area of flow separation to occur near the pressure surface (PS) instead of on the suction surface (SS). The flow separation and loss gradually increased from the hub to the shroud. Meanwhile, the direction of tip leakage flow also changed, a streamwise vortex core was observed on the PS near the blade tip. The core mixed with the low-energy fluid on the PS, resulting in flow blockage, that changed the working profile of the rotor. As the mass flow rate increased to the turbine operating point, the intensity of interaction and influence area between the leakage flow and the main flow further increased, and the aerodynamic loss increased significantly.

Line mixing in the oxygen B band head.

We present the results of direct measurements of the line mixing parameters for two pairs of overlapping transitions at the band head of the oxygen B band. Measurements were performed with the frequency-stabilized cavity ring-down spectrometer assisted by an optical frequency comb. The recorded spectra were analyzed with line profiles comprising speed dependence, Dicke narrowing, and line mixing. Incorporation of the line mixing into the model eliminated previous discrepancies for pressure shift and their speed dependence coefficients. First-order line mixing was determined directly from the line shape fitting at relatively low pressure (0.04 atm) together with other line shape parameters and compared with that calculated by Sung et al. [J. Quant. Spectrosc. Radiat. Transfer 235, 232-243 (2019)].

A Study on the Increase of Perceivable Information in the Saccade with High Speed Line Display

A Study on the Increase of Perceivable Information in the Saccade with High Speed Line Display

Experimental investigation and process parameter optimization of sheet metal bending by line heating method

The present study is concerned with the experimental investigation of sheet metal deforming by line heating method that incorporates the combined effect of traverse speed of the torch, thickness of the sheet metal, and the number of passes of the torch. For the numerical analysis of metal bending by line heating, the finite element method is employed and the design of an experiment with an orthogonal array L9 is used for the experimental investigation and parameter optimization. Mild steel of 300 × 200 mm is used for both numerical and experimental investigation. The results from the two approaches show that the thermal deformation of the sheet metal mainly depends on geometrical parameters like the thickness of the metal. From the result, a 2 mm thickness metal with a 5 mm/s travel speed and single-pass line heating are the best optimum combinations for the maximum temperatures and deformations. The deformations generated from this case are 0.25 mm from the reference plane with a peak temperature gradient of 667.5 °C. And also, for the required amount of deformation, the thickness has a significant effect than travel speed and number of passes with a percentage contribution of 93.48%, 5.69%, and 0.41% respectively. And also, for the two approaches, numerical modeling is well agreed with the experiments. Finally, it has been shown that the numerical modeling of the moving heat source developed for this purpose accurately predicts the real process in a mechanical workbench with a user interface.

Influence of the nonlinear behaviour of ballast on the dynamics of simply supported railway bridges

In this work, the vertical motion of a simply supported railway bridge which is subjected to the circulation of high speed trains was studied. A system consisting of two-layer beam was considered to model the dynamics of the bridge structure. The upper beam represents the rails with the sleepers and the lower beam the bridge deck. These two beams are coupled through distributed nonlinear springs that model the ballast action. The characteristics of these elements were identified from experimental measurements performed on real rail track. Considering the circulation of high speed train at given velocity, the influence of the nonlinear stiffness of the ballasted track on the response of the bridge system was analyzed. This was achieved by using the Galerkin method and the Runge-Kutta scheme to solve numerically the nonlinear partial differential equations governing the motion of the two beams. It was found that the nonlinear behaviour of the ballast affects notably the dynamics of the bridge, especially when the ballast stiffness is low. The proposed modelling enables to get more understanding regarding the vertical dynamics of ballasted track bridge in high speed line.

Influence of Blade Lean on Performance and Shock Wave/Tip Leakage Flow Interaction in a Transonic Compressor Rotor

Blade lean has been extensively used in axial compressor stators to control flow separations, but its influence mechanism on transonic compressor rotors remains to be revealed. The aim of this study is to numerically explore the influence of blade lean on the performance and shock wave/tip leakage flow interaction in a transonic compressor rotor. The effects of leaned pattern (positively lean and negatively lean), leaned angle and leaned height were studied. Results showed that, compared with baseline configuration, the efficiency and total pressure ratio of the entire constant rotating speed line of positively leaned rotor were both decreased. The absolute value of peak efficiency was reduced by as much as 4.34% at 20° lean angle, whereas the maximum reduction of peak total pressure ratio was 0.1 at 20° lean angle. The tip leakage flow streamlines of baseline transonic rotor can be divided into two parts, i.e., the primary vortex and secondary vortex which arises after the shock. Due to shock/tip leakage vortex interaction, the primary vortex enlarged and low-momentum region showed up after the shock; under near stall (NS) condition, tip leakage vortex breakdown occurred after interacting with shock. As positively leaned angle increased, the shock and the shock/tip leakage vortex interaction point moved upstream. In addition, the phenomenon of tip leakage vortex breakdown was enhanced. For negatively leaned rotors, as negatively leaned angle increased, the peak efficiency and total pressure ratio showed a tendency of first increasing and then decreasing. At 5° leaned angle, the peak efficiency was increased by 0.8% at most, and the maximum increment of total pressure ratio was 0.05 at 5° leaned angle. Besides, the loading of blade tip reduced and the loading moved toward trailing edge, resulting in the downstream movements of primary vortex, shock front and shock/tip leakage vortex interaction location. The results may help to improve the near tip flow field of transonic compressor rotor with leaned blade technology.

THE COMPARISON OF THE DYNAMIC TESTS RESULTS FROM SENSORY PLATFORMS

The article deals with dynamic plantography, which is a popular diagnostic method focused on assessment of the foot condition during walking and to expose foot disorders. The aim of the paper is to discover whether it’s possible to do dynamic analyses on short platforms by using comparison of short and long sensory platform output. To get dynamic output were used ImportaMedica platforms, specific long platform Elegance and short platform Speed. Three subjects were involved in dynamic test on both platforms. The evaluated parameters were surface of the foot, maximum and average pressure, speed and gait line. By comparing these parameters the biggest difference was discovered in adapting walking because of the correct tread on short platform. When comparing the outputs from the long and short platforms, a longer duration of the right and left footsteps was recorded for all three subjects on the short platform.

A comparative analysis of converters performance using various control techniques to minimize the torque ripple in BLDC drive system

Because of its high consistent quality, essential edge, high capability, rapid dynamic reaction, preservationist estimation, and cheap maintenance independently, the BLDC motor is widely utilised in military, industrial, and business applications. In comparison to conventional machines, the torque ripples of a BLDC motor are greatly impacted by the speed and transient line current in the commutation interval. This study investigates the value of torque ripple reduction in a BLDC motor drive system by looking at speed, current, and commutation problems. The FOPID and MRPID controllers were used to reduce torque ripple in BLDC motors caused by mistake tuning optimum gain controllers. The FOPID and MRPID controllers are offered for controlling the motor's current and speed. This suggested suppression circuit employs a modified Landsman converter and a modified Luo converter, with the obligation cycle adapted to get the optimal DC-bus voltage based on the BLDC motor's speed. The proposed method is used to hold the supported converter in place by reducing ripples by regulating the yield torque. The performance of the speed, current, and torque regulating systems is improved by modelling a BLDC motor drive system based on a modified Luo converter. In this work, a novel technique combining Elephant Herding Optimization (EHO) and Adaptive Neuro Fuzzy Inference System (ANFIS) based on the MRPID controller scheme is suggested and compared, including EHO-ANFIS with FOPID, GA-ANFIS with PID, and PSO with PID. The suggested EHO ANFIS technique's major goal is to reduce and regulate speed, current, and torque problems in BLDC motor drive systems. Simulation is carried out in the MATLAB SIMULINK model to achieve the goal.

Analysis of the speed and curvature of the trajectory in the problem of pursuing a set of targets

Introduction. A kinematic model of group pursuit of a set of targets on a plane is considered. Pursuers use a technique similar to parallel approach method to achieve goals. Unlike the parallel approach method, the speed vectors of pursuers and targets are directed arbitrarily. In the parallel approach method, the instantaneous directions of movement of the pursuer and the target intersect at a point belonging to the circle of Apollonius. In the group model of pursuing multiple goals, the pursuers try to adhere to a network of predictable trajectories.Materials and Methods. The model sets the task of achieving goals by pursuers at designated points in time. This problem is solved by the methods of multidimensional descriptive geometry using the Radishchev diagram. The predicted trajectory is a composite line that moves parallel to itself when the target moves. On the projection plane “Radius of curvature — speed value”, the permissible speed range of the pursuer is displayed in the form of level lines (these are straight lines parallel to one of the projection planes). Images of speed level lines are displayed on the projection plane “Radius of curvature — time to reach the goal”. The search for points of intersection of the speed line images and the appointed time level line is being conducted. Along the communication lines, the values of the intersection points are lowered to the plane “Radius of curvature — speed value”. Using the obtained points, we construct an approximating curve and look for the intersection point with the line of the assigned speed. As a result, we get values of the radius of the circle at the predicted line of the trajectory of the pursuer.Results. Based on the results of the conducted research, test programs have been created, and animated images have been made in the computer mathematics system.Discussion and Conclusions. This method of constructing trajectories of pursuers to achieve a variety of goals at a given time values can be in demand by developers of autonomous unmanned aerial vehicles.

Pupil responses to implied motion in figurative and abstract paintings.

Motion can be perceived in static images, such as photos and figurative paintings, representing realistic subjects in motion, with or without directional information (e.g., motion blur or speed lines). Motion impression can be achieved even in non-realistic static images such as motion illusions and abstract paintings. It has been shown that visual motion processing affects the diameter of the pupil, responding differently to real, illusory, and implied motion in photographs (IM). It has been suggested that these different effects might be due to top-down modulations from different cortical areas underlying their processing. It is worthwhile to investigate pupillary response to figurative paintings, since they require an even higher level of interpretation than photos representing the same kind of subjects, given the complexity of cognitive processes involved in the aesthetic experience. Also, pupil responses to abstract paintings allows to study the effect of IM perception in representations devoid of real-life motion cues. We measured pupil responses to IM in figurative and abstract artworks depicting static and dynamic scenes, as rated by a large group of individuals not participating in the following experiment. Since the pupillary response is modulated by the subjective image interpretation, a motion rating test has been used to correct individual pupil data according to whether participants actually perceived the presence of motion in the paintings. Pupil responses to movies showing figurative and abstract subjects, and to motion illusions were also measured, to compare real and illusory motion with painted IM. Movies, both figurative and abstract, elicit the largest pupillary dilation of all static stimuli, whereas motion illusions cause the smallest pupil size, as previously shown. Interestingly, pupil responses to IM depend on the paintings’ style. Figurative paintings depicting moving subjects cause more dilation than those representing static figures, and pupil size increases with the strength of IM, as already found with realistic photos. The opposite effect is obtained with abstract artworks. paintings depicting motion produce less dilation than those depicting stillness. In any case, these results reflect the individual subjective perception of dynamism, as the very same paintings can induce opposite responses in observer which interpreted it as static or dynamic. Overall, our data show that pupil size depends on high-level interpretation of motion in paintings, even when they do not represent real-world scenes. Our findings further suggest that the pupil is modulated by multiple top-down cortical mechanisms, involving the processing of motion, attention, memory, imagination, and other cognitive functions necessary for enjoying a complete aesthetic experience.

Turbulence Measurements at the Inlet of an Automotive Turbocharger Compressor Using Stereoscopic Particle Image Velocimetry

Abstract The present work uses stereoscopic particle image velocimetry (SPIV) to analyze the compressor inlet flow field, with specific emphasis on its turbulence characteristics during flow reversal in order to gain further insight into the inlet flow structures. SPIV experiments were carried out at the inlet of a centrifugal compressor without any recirculation channel at four different rotational speeds (from 80 to 140 krpm) and over the entire mass flow range (from choke to surge) at each speed. Detailed analyses have been carried out for the mean velocity field, the mean vorticity field, and the turbulent statistics including turbulent kinetic energy, Reynolds stress, and the one-dimensional energy spectra. The turbulent kinetic energy at the compressor inlet was observed to increase rapidly along a speed line with decreasing mass flowrate once flow reversal started, and the turbulence became more anisotropic. As the flowrate was reduced (along a speed line), the zone with maximum turbulent kinetic energy moved from the periphery toward the center of the inlet duct and also occurred further upstream from the impeller. The Reynolds stress distributions suggest that the Boussinesq assumption of an isotropic eddy viscosity may not be appropriate after the detection of flow reversal. The Reynolds shear stresses were observed to change signs with their corresponding velocity gradients at the tested mass flowrates at different rotational speeds. At the investigated flowrates, the radial gradients in the axial and tangential velocities were found to be most dominant.

Redesign of casing treatment for a transonic centrifugal compressor based on a hybrid global optimization method

As a typical black-box problem, recirculating casing treatment (RCT) optimization of compressor stages is computationally intensive and time consuming, even though surrogate models are usually employed. In order to improve efficiency and robustness of the optimization, an expected-improvement (EI) based hybrid global optimization (EHGO) algorithm is developed by coupling an EI-based surrogate model with a hybrid optimization algorithm. Highly nonlinear and multiple modality mathematical tests show that the EHGO algorithm is able to create a high-fidelity surrogate model near targeted regions with less evaluated samples, and to obtain the global optimal solution simultaneously. The RCT of a compressor stage is optimized based on this algorithm. The number of CFD simulations required for obtaining an optimum solution is greatly reduced, as compared to similar studies using conventional methods. The optimization results show that the aerodynamic performance is improved over the whole speed line and the flow range is also extended. The dominant factors for the performance improvements and the enhanced stall margin are addressed by analyzing the local flow characteristics before and after optimization. It is found that those factors include: removing a larger amount of low-momentum fluid, achieving a more uniform flow of impeller passage in circumferential direction, and reducing the radial distortion of impeller inlet flow. The proposed algorithm has the potential to considerably speed up the optimization process and make the optimization much more accessible. It can be generalized to deal with other computationally intensive black-box problems, for example, turbomachinery optimization.

Pupillary response to real, illusory, and implied motion.

The perception of moving objects (real motion) is a critical function for interacting with a dynamic environment. Motion perception can be also induced by particular structural features of static images (illusory motion) or by photographic images of subjects in motion (implied motion, IM). Many cortical areas are involved in motion processing, particularly the medial temporal cortical area (MT), dedicated to the processing of real, illusory, and implied motion. Recently, there has been a growing interest in the influence of high-level visual processes on pupillary responses. However, just a few studies have measured the effect of motion processing on the pupil, and not always with consistent results. Here we systematically investigate the effects of real, illusory, and implied motion on the pupil diameter for the first time, by showing different types of stimuli (movies, illusions, and photos) with the same average luminance to the same observers. We find different pupillary responses depending on the nature of motion. Real motion elicits a larger pupillary dilation than IM, which in turn induces more dilation than control photos representing static subjects (No-IM). The pupil response is sensitive even to the strength of IM, as photos with enhanced IM (blur, motion streaks, speed lines) induce larger dilation than simple freezed IM (subjects captured in the instant they are moving). Also, the subject represented in the stimulus matters: human figures are interpreted as more dynamic and induce larger dilation than objects/animals. Interestingly, illusory motion induces much less dilation than all the other motion categories, despite being seen as moving. Overall, pupil responses depend on the individual perception of dynamicity, confirming that the pupil is modulated by the subjective interpretation of complex stimuli. We argue that the different pupillary responses to real, illusory, and implied motion reflect the top-down modulations of different cortical areas involved in their processing.

Filtering property of periodic pile barriers under moving loads

The attenuation property of periodic pile barriers for elastic-wave propagation in certain direction induced by stationary loading sources has been extensively investigated. However, the corresponding studies under moving-load excitations are rather limited due to the complexity caused by the time-varying feature of the induced wave-propagation directions. To address this issue, this paper investigates the vibration isolation performance of periodic pile barriers under moving loads. Using the periodic structure theory, a novel method for deriving the attenuation zones of periodic pile barriers under harmonic moving loads is proposed, which allows calculation of the directional attenuation zones (DAZs) for waves propagating in different directions. This is realized by combining the moving-load speed line with the dispersion properties of periodic pile barriers. A simplified numerical model is also developed to analyze the dynamic responses of the periodic pile barriers in frequency domain. The responses of periodic pile barriers under different moving loads are also conducted in time domain to validate the theoretical predictions. The two-dimensional (2D) Fourier transform in both time and space domain is used to study the filtering property of periodic pile barriers under harmonic moving loads and to reveal their vibration isolation mechanism. It is found that different from the stationary loading situation, for which the induced elastic waves mostly propagate in one certain direction, the filtering property of periodic pile barriers under moving loads is related to its dispersion properties along each possible wave-propagation direction. Besides, the attenuation zones for the moving loads are dependent not only on the dispersion properties of the periodic pile barriers, but also on the loading itself, namely the velocity and excitation frequency of the moving load.

Effect of nozzle exit area on the performance of a turbojet engine

The thrust produced by a gas turbine engine can be optimized by suitably changing the nozzle geometry in conjunction with other control parameters. However, varying the nozzle geometry influences the performance of the upstream rotating machinery and shifts the equilibrium running line on the compressor map. In the present study, to investigate the influence of the nozzle area on engine performance, experiments are conducted on a small gas turbine engine. A total of three tests are conducted. The first being a baseline test, without any nozzle area reduction. For the subsequent tests, the jet pipe exit area is reduced using a suitably designed throttle cone, simulating nozzle area reduction. The engine component performances are monitored using suitably placed pressure sensors, thermocouples and microphones. The results show that when the throttle setting was unaltered, with a 23% decrease in the nozzle exit area, engine rotor speed reduced to ∼55,000 RPM from the initial setting of ∼70,000 RPM, EGT increased by ∼250 K, thrust reduced by ∼30% and OASPL remained relatively constant. All of the above is caused by a reduction in air mass flow rate ingested by the engine. However, when the same nozzle exit area reduction was imposed at constant rotor speed, engine operation moved along a constant speed line on the compressor map, moving closer to the surge line. The EGT increased by ∼200 K, thrust increased by ∼18% and in order to maintain the same rotor speed, fuel-air-ratio increased by ∼41%. The dominant effect when operating at constant rotor speed is the increase in fuel flow rate, which contributes to an improved engine performance as compared to the constant throttle setting case.

Development and Validation of a Model for Centrifugal Compressors in Reversed Flow Regimes

Abstract Turbochargers are widely used to help reduce the environmental impact of automotive engines. However, a limiting factor for turbochargers is compressor surge. Surge is an instability that induces pressure and flow oscillations that often damages the turbocharger and its installation. Most predictions of the surge limit are based on low-order models, such as the Moore–Greitzer model. These models tend to rely on a characteristic curve for the compressor created by extrapolating the constant speed lines of a steady-state compressor map into the negative mass flow region. However, there is little validation of these assumptions in the public literature. In this article, we develop further the first-principles model for a compressor characteristic presented in Powers, K., Brace, C., Budd, C., Copeland, C., & Milewski, P., 2020, “Modeling Axisymmetric Centrifugal Compressor Characteristics From First Principles,” J. Turbomachinery, 142(9), with a particular emphasis on reverse flow. We then perform experiments using a 58 mm diameter centrifugal compressor provided by Cummins Turbo Technologies, where we feed air in the reverse direction though the compressor while the impeller is spinning in the forward direction to obtain data in the negative mass flow region of the compressor map. This demonstrated experimentally that there is a stable operating region in the reverse flow regime. The recorded data showed a good match with the theoretical model developed in this article. We also identified a change in characteristic behavior as the impeller speed is increased, which, to the authors’ knowledge, has not been observed in any previously published experimental work.

Research on Improvement of Maintenance Quality of Common Speed Railway Public Works Based on Computer Maintenance Technology

With the rapid development of transportation technology, the application of railway transportation is more and more widely, which has become an important livelihood project. Therefore, we need the railway department to continuously strengthen the maintenance work of Railway public Works (hereinafter referred to as RPW) technology. Compared with the operation efficiency of railway, the operation efficiency of common speed line is higher, which requires us to strengthen and improve the maintenance management of common speed line. Through computer technology, the railway department can fully implement the mode of “maintenance and repair”, which will avoid the current situation of high wear and tear of heavy haul railway. By gradually improving the maintenance level, we can improve the equipment support ability, which has a certain promotion value for the railway line workshop maintenance. First of all, this paper analyzes the key points of RPW maintenance, and then, this paper analyzes the construction of comprehensive data platform of RPW maintenance plan. Finally, some suggestions are put forward.

Morphology, structure and photoelectric properties of F-doped SnO2 films under flexible PET mask reinforced laser annealing

Laser annealing has important significance for performance improvement of transparent conductive oxide (TCO)-based thin films. In this study, we further developed the simple flexible polyethylene terephthalate (PET) mask reinforced laser annealing (FPLA) process through covering a transparent PET sheet on the film surface to achieve performance improvement of fluorine-doped tin oxide (FTO) films. Scan control strategy during FPLA involving scanning speed and scan line spacing was determined by analyzing surface morphology, surface roughness, crystal structure and photoelectric properties of the films. It was found that line-by-line round-trip scanning using the optimal scanning speed of 10 mm/s and scan line spacing of 20 μm resulted in the more effective FPLA effect. The as-obtained FTO film exhibited a low-fluctuated surface with remarkably enlarged and dense particles, the lowest RMS roughness, the largest grain size, and thus the maximum figure of merit of 3.05 × 10−2 Ω−1, which was about 1.8 times that of the direct laser-annealed FTO film using the same parameters. The effectiveness of the PET sheet used for FPLA in redepositing the film materials and inhibiting the decrease of oxygen vacancies was further confirmed by mechanism analysis using SEM, EDX and XPS characterizations.

COMICS AS A TRANSMEDIAL PHENOMENON: FROM A PRINTED TO A DIGITAL MEDIUM

Comics have recently attracted the increased attention of theorists as a very dynamic and fast-growing genre. A characteristic feature of contemporary comics is their transmediality, i.e., exceeding the boundaries of the printed page and transforming to digital narratives. Transition to a digital medium gives a number of advantages, including the possibility of using different display modes, deeper immersion in the fictional world, greater degree of interactivity. This paper examines comics, which are adaptations of the classic fairy tale Little Red Riding Hood, identifies intertextual references and modifications of the comics versions. Intertextual references can be traced at the level of comics titles, names of the characters and their characteristics, semi-quotes, which paraphrase the original texts, besides, comics have a different temporal and spatial setting, they extend the scope of the storyworld. Particular attention has been paid to the page layout, such comics-specific features as panels, frames, speech balloons, speed lines, emanata, and onomatopoeic words. Print and digital comics are analysed using narratological and multimodal approaches. The analysis includes such narratological issues as narratorial and nonnarratorial strategies of representation, the temporal and spatial structure of a narrative, internal and external focalisation, as well as focalisation-marking devices (the eyeline match, the over-the-shoulder shot, the high-angle shot). A comic is a multimodal narrative, combining several modes, mainly visual and verbal. The aural mode is represented in comics by linguistic and visual signs, e.g., jagged borders of a speech balloon or the size and boldness of letters. Special attention has been given to the interaction between visual and verbal modes, in particular to the text-image relations. Our analysis has identified such types of the text-image relations as specification, exemplification, and enhancement. Comics have recently attracted the increased attention of theorists as a very dynamic and fast-growing genre. A characteristic feature of contemporary comics is their transmediality, i.e. exceeding the boundaries of the printed page and transforming to digital narratives. Transition to a digital medium gives a number of advantages, including the possibility of using different display modes, deeper immersion in the fictional world, greater degree of interactivity. This paper examines comics, which are adaptations of the classic fairy tale Little Red Riding Hood, identifies intertextual references and modifications of the comics versions. Intertextual references can be traced at the level of comics titles, names of the characters and their characteristics, semi-quotes, which paraphrase the original texts, besides, comics have a different temporal and spatial setting, they extend the scope of the storyworld. Particular attention has been paid to the page layout, such comics-specific features as panels, frames, speech balloons, speed lines, emanata, and onomatopoeic words. Print and digital comics are analysed using narratological and multimodal approaches. The analysis includes such narratological issues as narratorial and nonnarratorial strategies of representation, the temporal and spatial structure of a narrative, internal and external focalisation, as well as focalisation-marking devices (the eyeline match, the over-the-shoulder shot, the high-angle shot). A comic is a multimodal narrative, combining several modes, mainly visual and verbal. The aural mode is represented in comics by linguistic and visual signs, e.g., jagged borders of a speech balloon or the size and boldness of letters. Special attention has been given to the interaction between visual and verbal modes, in particular to the text-image relations. Our analysis has identified such types of the text-image relations as specification, exemplification, and enhancement.

ДИСКУРС ИНФРАСТРУКТУРЫ КАК ОБЩЕСТВЕННОГО БЛАГА

The article presents a complex review of infrastructure as public good. Positive externalities of infrastruc-ture in the form of six levels of a pyramid of external effects of high speed lines are shown. These externalities provide payback of the investment project and also define an infrastructure role in restoration of economic growth rates in the conditions of pandemic crisis. Infrastructure investments are a most important long-term subject to capital investments. The solution of this problem depends of continuous updating of financing model of infrastructure public goods production based on interaction of the state, private business and the population of any country.