Mode Of Movement Research Articles

Movement of the endoplasmic reticulum is driven by multiple classes of vesicles marked by Rab-GTPases.

Peripheral endoplasmic reticulum (ER) tubules move along microtubules to interact with various organelles through membrane contact sites (MCS). Traditionally, ER moves by either sliding along stable microtubules via molecular motors or attaching to the plus ends of dynamic microtubules through tip attachment complexes (TAC). A recently discovered third process, hitchhiking, involves motile vesicles pulling ER tubules along microtubules. Previous research showed that ER hitchhikes on Rab5- and Rab7-marked endosomes, but it is uncertain if other Rab-vesicles can do the same. In U2OS cells, we screened Rabs for their ability to cotransport with ER tubules and found that ER hitchhikes on post-Golgi vesicles marked by Rab6 (isoforms a and b). Rab6-ER hitchhiking occurs independently of ER-endolysosome contacts and TAC-mediated ER movement. Depleting Rab6 and the motility of Rab6-vesicles reduces overall ER movement. Conversely, relocating these vesicles to the cell periphery causes peripheral ER accumulation, indicating that Rab6-vesicle motility is crucial for a subset of ER movements. Proximal post-Golgi vesicles marked by TGN46 are involved in Rab6-ER hitchhiking, while late Golgi vesicles (Rabs 8/10/11/13/14) are not essential for ER movement. Our further analysis finds that ER to Golgi vesicles marked by Rab1 are also capable of driving a subset of ER movements. Taken together, our findings suggest that ER hitchhiking on Rab-vesicles is a significant mode of ER movement. [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text].

Dynamic response of spring valve subjected to underwater pressure pulse

Spring-loaded valves are widely used to protect sealed containers filled with liquid against sudden excessive overpressure; however, the unstable vibration of a valve spool under dynamic loading may lead to safety incidents. This study aims to investigate the nonlinear vibration processes of a valve spool subjected to an underwater pressure pulse. To achieve this objective, the spring-loaded valve was simplified to an air-back mass spring with a constraint boundary (AMSCB). A modified split Hopkinson pressure bar (SHPB) was adopted to generate a controllable pressure pulse to establish the relationship between the specific impulse and the discharged water mass. Following the experimental verification, the influences of the pressure pulse parameters and dimensionless time on the motion characteristics of the mass block and flow rate were studied based on finite element (FE) simulations. Five motion modes were identified according to the number of collisions with the constraint boundary and changes in movement direction: (i) no collision, (ii) single collision, (iii) chatter, (iv) single collision with direction change, (v) multiple collisions. Moreover, a theoretical model for predicting the movement of a mass block was developed and validated against numerical results. The classification phase diagram of the motion mode is presented in a two-dimensional plane composed of specific strength coefficient ϕ and fluid-structure interaction coefficient ψ, and the influence of the geometrical parameters of the AMSCB on the classification boundary of motion modes is presented. The results indicate that, when subjected to underwater pressure pulse loading, the mass block repeatedly collides with the constraint boundary and undergoes non-periodic motion. With higher loading pressure amplitude and duration, the mass block is more likely to collide with the back boundary, leading to a transition in movement modes from mode (i), mode (ii), mode (iv) to mode (v). Increasing the stiffness coefficient and areal density will increase the threshold of ϕ and ψ for the transition from mode (i) to mode (v), while the maximum allowable displacement has little effect on the classification boundaries. These research findings are valuable for analysing the motion response of mass spring with various constraint boundaries under dynamic loading, and for guiding the design of spring-loaded valves.

ОПРЕДЕЛЕНИЕ НАИБОЛЕЕ ПОВРЕЖДАЮЩИХ ПО КРИТЕРИЮ УСТАЛОСТИ ЭКСПЛУАТАЦИОННЫХ РЕЖИМОВ НАГРУЖЕНИЯ НЕСУЩИХ КОНСТРУКЦИЙ КУЗОВА КАРЬЕРНОГО САМОСВАЛА

A procedure is developed for the calculation and experimental assessment of the operatonal modes damaging effect on the load-bearing structure of a dump truck body. The procedure makes it possible to determine the most dangerous zones of the load-bearing structure according to the multicycle fatigue criterion, as well as to assess the damaging effect of individual operatonal modes forming the dump truck working cycle. Analysis of the loading and fatigue damage accumulation of the load carrying structures of the BELAZ 7558 dump truck body was used for the procedure testing. Structure loadings have been determined for eight operating modes, including loading and unloading the body with bulk cargo during field tests. Processes of change of mechanical axial stresses during the tests were registered in eight zones. Experimental data analysis revealed two zones of the structure where the fatigue damage accumulation happens more than twice as fast as in the others. It is established that dump truck movement modes for technological road and the road in the dump area are characterized by the greatest fatigue damage accumulation. For the truck whole working cycle the most damaging movement mode for body is moving on the technological road. At the same time, the greatest unit equivalent fatigue damaging effect is formed by moving on the dump road and is greater than the corresponding value for the technological road by about 1.5 times. This is explained by the fact that the length of the technological road in the considered working cycle of the dump truck is 7 times more than the length of the dump road.

Computational model of a feeding copepod engaged in three modes of movement

Abstract Objectives: Copepods display distinct feeding modes to capture prey in the surrounding water. However, the mechanism and range of prey detection are not fully understood. Methods: Using the method of regularized Stokeslets, we constructed a mathematical model of the flow field around a copepod engaged in three modes of movement: sinking, swimming and hovering. The model assumes that the copepod is negatively buoyant with a simplified body and a pair of long antennae. We then introduced a rigid, neutrally buoyant sphere in the model to predict where potential prey items become detectable in theory. Key Findings: We find that the flow fields around the sinking and swimming models are generally unidirectional, while the flow around a hovering copepod has a significant cross-stream component. Our model shows that the volume of the surrounding fluid that is predicted to be inspected has distinctive shapes that resemble a thin sheet while sinking, a cylinder while swimming and a funnel while hovering. Conclusion: The results suggest that the most efficient mode of feeding depends on the distribution of prey items in the surrounding water.

Impact of Polymorphic Microfibers for Establishment of Neuronal Model

ABSTRACTThe biological and mechanical environment of cells is better mimicked in 3D compared to 2D cell cultures. However, creating accurate 3D cell culture models particularly for ultra‐soft tissues like brain or spinal cord is challenging since the hydrogels that match these properties are mechanically fragile. Therefore, implementing reinforcing structures, such as microfibers, is essential to provide the necessary support. Particularly, fibrous systems are of interest since they offer natural fibrillar structures similar to the extracellular matrix. This study focuses on exploring the interactions between a motor neuron‐like cell line and multiple microfiber‐morphologies and mechanics. Monitoring cell‐microfiber interactions over time we unveiled various dynamic undetected behaviors and interactions happening upon contact depending on the used microfiber properties. These highly defined microfiber fragments were fabricated using multiple processes—electrospinning, Melt Electrowriting, and microfluidic spinning—with properties differing in size, mechanics, and surface chemistry. The excellent control over our microfiber systems enabled the investigation of single parameters in an isolated manner. In addition, we quantified the observed varying movement modes of the monitored cell‐microfiber tandems. The study demonstrates the significance of microfiber design for biological applications and establishes methodological foundations for the implementation of customized microfiber systems in the field of biofabrication.

The Trail Making Test in Virtual Reality (TMT-VR): The Effects of Interaction Modes and Gaming Skills on Cognitive Performance of Young Adults

Virtual Reality (VR) is increasingly used in neuropsychological assessments due to its ability to simulate real-world environments. This study aimed to develop and evaluate the Trail Making Test in VR (TMT-VR) and investigate the effects of different interaction modes and gaming skills on cognitive performance. A total of 71 young female and male adults (aged 18–35) with high and low gaming skills participated in this study. Participants completed the TMT-VR using three interaction modes as follows: eye-tracking, head movement, and controller. Performance metrics included task completion time and accuracy. User experience, usability, and acceptability of TMT-VR were also examined. Results showed that both eye tracking and head movement modes significantly outperformed the controller in terms of task completion time and accuracy. No significant differences were found between eye tracking and head movement modes. Gaming skills did not significantly influence task performance using any interaction mode. The TMT-VR demonstrates high usability, acceptability, and user experience among participants. The findings suggest that VR-based assessments can effectively measure cognitive performance without being influenced by prior gaming skills, indicating potential applicability for diverse populations.

ANALYSIS OF NOISE CHARACTERISTICS OF TRAFFIC FLOWS ON THE EXAMPLE OF KRASNODAR

In this article, the authors consider the noise characteristics of traffic flows in urban conditions. The unevenness of traffic flows in time and space entails a change in noise effects on the environment. The main source of noise pollution is the internal combustion engine, which produces aerodynamic noise and structural noise. Noise level measurements are carried out separately for vehicles in motion and for stationary vehicles. The noise level is directly influenced by the mode of movement of cars, the speed of traffic flow, and the intensity of traffic flow. Deterioration of working and leisure conditions with a high level of traffic noise can lead to a decrease in labor productivity and the occurrence of nervous disorders. Therefore, the protection of the population from the noise generated by transport is not only of social, but also of economic importance. Purpose: to analyze the level of noise impacts of traffic flow in urban conditions. Method and methodology. The methods of observation, statistical analysis, and synthesis were used in the article. Results: noise level measurements were carried out on the selected section of the road network, and calculated data were obtained based on the declared characteristics of the traffic flow. Scope of application of the results: research activities to improve the environmental safety of the traffic flow.

A Versatile Microporous Design toward Toughened yet Softened Self-Healing Materials.

Realizing the full potential of self-healing materials in stretchable electronics necessitates not only low modulus to enable high adaptivity, but also high toughness to resist crack propagation. However, existing toughening strategies for soft self-healing materials have only modestly improves mechanical dissipation near the crack tip (ГD), and invariably compromise the material's inherent softness and autonomous healing capabilities. Here, a synthetic microporous architecture is demonstrated that unprecedently toughens and softens self-healing materials without impacting their intrinsic self-healing kinetics. This microporous structure spreads energy dissipation across the entire material through a bran-new dissipative mode of adaptable crack movement (ГA), which substantially increases the fracture toughness by 31.6 times, from 3.19 to 100.86 kJ m-2, and the fractocohesive length by 20.7 times, from 0.59 mm to 12.24 mm. This combination of unprecedented fracture toughness (100.86 kJ m-2) and centimeter-scale fractocohesive length (1.23 cm) surpasses all previous records for synthetic soft self-healing materials and even exceeds those of light alloys. Coupled with significantly enhanced softness (0.43 MPa) and nearly perfect autonomous self-healing efficiency (≈100%), this robust material is ideal for constructing durable kirigami electronics for wearable devices.

Equivalent Simulation Study of Delta-Rotor Engine

The mechanical structure, movement mode, and combustion process of a triangular rotor engine differ from those of a conventional engine with a crank connecting rod mechanism as the core. This makes it impossible to directly use existing simulation software to simulate the performance of the entire engine, rendering it difficult to conduct structural evaluation and performance prediction during the engine development stage. Therefore, using existing performance simulation software to establish a performance-equivalent model for a triangular rotor engine is crucial. To solve the above problems, this study proposes a performance-equivalent simulation modelling method for a triangular rotor engine based on a three-dimensional simulation model and the operating principles of the triangular rotor and four-stroke engines. Compared to various performance indicators obtained from the three-dimensional simulation model, the results show that the equivalent model established in this study has sufficient accuracy for key indicators such as the cylinder pressure, cylinder temperature, and in-cylinder quality under various working conditions. This can satisfy the requirements of the complete machine-performance simulation of a triangular rotor engine.

Sports and activity games as a means of increasing the motive activity of educators

At the current stage, the problem of insufficient movement mode of the participants of the educational process, which negatively affects their physical development and the state of mental processes, in particular: feeling, perception, thinking, memorization, attention, needs special attention. This fact reduces the success of studies to some extent. Therefore, it is necessary to look for ways to use such means of motor activity that would contribute to the improvement of the physical and psychological condition of students. The goal is to reveal the peculiarities of the use of mobile and sports games in the educational process of physical education in higher education institutions as a means of improving the motor activity of students. Research results. The expediency of using the sports and game method in the process of physical education of students, which provides sufficient physical activity and contributes to strengthening health, forms moral and willpower qualities of the individual, is revealed. A rich arsenal of sports games, including basketball, volleyball, mini-football, their nature, structure and intensity are highlighted. It is noted that with the help of sports games, students develop important physical qualities: strength, speed, dexterity, endurance, consolidate and improve various skills and abilities in walking, running, jumping. Attention is paid to the careful selection of mobile games, taking into account the physical fitness and interests of students, their capabilities, which will make it possible to diversify classes and form the necessary motor skills. Conclusions. The use of the sports and game method in physical education classes contributes to the comprehensive development of the student's personality, as it causes positive emotions, a sense of satisfaction, cheerfulness, activity, and has a positive effect on physical and mental development.

Design, Analysis, and Optimization Testing of a Novel Modular Walking Device for Pipeline Robots

This article investigates the limitations associated with traditional wheel-type pipeline walking devices, which are characterized by a single movement mode and an inability to navigate complex or irregular pipeline structures. A modular walking device (MWD) designed for pipeline robots was developed utilizing structural and mechanical analysis techniques. The reliability of the mechanical analysis was validated through single-factor dynamic testing. To analyze and optimize the factors influencing the maneuverability and obstacle-crossing capabilities of the MWD, a three-factor, three-level orthogonal testing method was utilized. The factors examined included the rotational speed of the walking wheel (RS), the pre-tightening force of the wheel brackets (PF), and the height of the annular obstacle (OH). The evaluation metrics used were the slip rate and passability. The results indicated that a parameter combination of RS at 70 rpm, PF at 30 N, and OH at 10 mm produced a slip rate of 11.6% ± 1.5%. During the obstacle traversal process, the remainder of the device maintained a safe distance from the obstacles, with only the walking wheel making contact. The verification testing also confirmed that the MWD is capable of executing three distinct modes of motion: rectilinear, rotational, and helical. The MWD designed and developed in this study can switch between multiple motion modes and successfully overcome obstacles within 15 mm, providing a new equipment for universities to enhance mechanized pipeline detection technology.

ПІДВИЩЕННЯ ГАЛЬМІВНОЇ ЗДАТНОСТІ ЛОКОМОТИВА ПРОМИСЛО-ВОГО ТРАНСПОРТУ З УРАХУВАННЯМ ЗУСИЛЬ У ЙОГО ЗЧІПНИХ ПРИСТРОЯХ

Objective: substantiation the rational concept of increasing the braking capacity of the industrial locomotive in transient modes of train movement, taking into account the force factor in its coupling device. Methodology of the work: theoretical studies of the energy from the deformation of the coupling devices of the industrial locomotive in the transient modes of train movement; theoretical studies of excessive coupling of locomotive wheels with rails in the presence of force on the locomotive's coupling device; determination of kinematic and dynamic parameters of the transient mode of train movement. A mathematical model of the train motion transitory process has been developed, it using the example of locomotive braking process, which allows determining the current values of train element velocities, as well as coupling forces, and has a low average discrepancy with the data of the technological calculation of industrial locomotive. Fixed: the force on the coupling device of the locomotive changes with a high frequency. The braking process is conventionally divided into 3 stages, which are characterized by oscillations, stabilization and a drop in clutch force; the energy corresponding to the change in force in the clutch during braking falls on 90.5% of the first and second stages. Taking into account the obtained results, the conceptual adjustment of the force of the coupling of the wheel pairs of the locomotive with the rails at the level of the maximum forces in the coupling device of the locomotive, determined by the simulation results, is adopted. Scientific novelty: improvement of the method of determining the required force of the traction the wheels of locomotive with the rails by taking into account the energy corresponding to the change in the effort in the coupling device of the locomotive during the braking time of the train. Practical value: the development of an improved concept by regulating the force the traction of locomotive wheel pairs with rails in transient modes of train movement, taking into account the energy assessment of the effort in the locomotive's coupling device.

Characterizing humpback whale behavior along the North-Norwegian coast

BackgroundStudying movement patterns of individual animals over time can give insight into how they interact with the environment and optimize foraging strategies. Humpback whales (Megaptera novaeangliae) undertake long seasonal migrations between feeding areas in polar regions and breeding grounds in tropical areas. During the last decade, several individuals have had up to a 3-month stop-over period around specific fjord-areas in Northern Norway to feed on Norwegian spring-spawning (NSS-) herring (Culpea harengus L.). Their behavioral patterns during this period are not well understood, including why some whales seemingly leave the fjords and then later return within the same season.MethodsTo investigate whale behavior during this seasonal stopover, we classified humpback whale tracks into five distinct movement modes; ranging, encamped, nomadic, roundtrip and semi-roundtrip. A behavioral change point analysis (BCPA) was used to select homogeneous segments based on persistence velocity. Then, net squared displacement (NSD) over time was modeled to differentiate movement modes. This study also manually identified longer roundtrips away from the fjords that lasted several days and examined movement modes within these.ResultsInside the fjord systems, encamped mode was most prevalent in December–January, suggesting the whales were mainly foraging on overwintering NSS-herring in this area. During the same winter seasons, half of the whales left the fjords and then returned. We hypothesize that these trips serve as ‘searching trips’ during which the whales seek better feeding opportunities outside the fjords. If better foraging conditions are not found, they return to the fjords to continue their feeding. The overall most common mode was ranging (54%), particularly seen during the start of their southwards migration and in areas outside the fjord systems, indicating that the whales mainly moved over larger distances in the offshore habitat.ConclusionsThis study serves as a baseline for future studies investigating both the searching trip theory and humpback whale behavior in general, and confirms that this method could be useful to analyze local scale movement patterns of satellite tagged whales.

A linkage-type self-adaptive deformable tracked mechanism based on the six-bar mechanism

Abstract. In order to design a self-adaptive tracked mechanism that can passively adjust according to the height of different obstacles to improve its obstacle-crossing performance, this paper proposes a linkage-type self-adaptive deformable tracked mechanism. The mechanism based on the planar six-bar mechanism is proposed, and its motion modes and obstacle-crossing capabilities are analyzed. Firstly, based on the characteristics of self-adaptive deformation and the planar six-bar mechanism, a deformable single-degree-of-freedom (DOF) multi-loop mechanism is designed by limiting the DOF and adjusting the link lengths, and subsequently, a linkage-type self-adaptive deformable tracked mechanism module is designed according to the multi-loop mechanism. Secondly, the movement characteristics of the deformable tracked mechanism module are analyzed, and it is obtained that the tracked mechanism has two modes of movement: forward and reverse. These modes include deformable tracked-type obstacle crossing and rocker-arm-type obstacle crossing, respectively. Additionally, it is also obtained that this mechanism is capable of climbing up and descending down slopes. Finally, a prototype model is designed for experimental verification to verify the correctness of the theoretical analysis of the linkage-type self-adaptive deformable tracked mechanism and the feasibility of the obstacle-crossing modes. The results indicate that the linkage-type self-adaptive deformable tracked mechanism is capable of various obstacle-crossing modes, including both forward and reverse movements. These modes encompass the traditional tracked type, the deformable tracked type, and the rocker-arm type, as well as the ability to climb up and descend down slopes. This type of mechanism demonstrates excellent terrain adaptability and is capable of overcoming obstacles, allowing it to traverse some soft and rugged terrain. Consequently, it holds certain application potential.

Influence of the inner tube rotation and translation associated movement on the charging performance for the latent heat thermal energy storage exchangers

Latent heat thermal energy storage technology can reduce energy consumption in buildings and improve economic performance. The inner tube movement improves the charging performance of the horizontal latent heat thermal energy storage exchangers. In order to improve the charging performance, this paper proposed a new inner tube rotation and translation associated movement mode, wrote the user-defined function based on the dynamic mesh technique, and focused on the influence of three movement modes included rotation, translation, rotation and translation associated movement on the charging performance. The results showed that the associated movement further improves the charging performance, compared with static inner tube, the charging time decreases by 53.1 %, the time average charging rate increases by 110.2 % and the average velocity of the phase change material enhances by 132.3 % under the conditions of 0.2 mm/s translation velocity and 0.4 rpm rotation velocity, compared with rotation movement individual under 0.4 rpm, the charging time decreases by 47.8 %, compared with translation movement individual under 0.2 mm/s, the charging time decreases by 21.6 %. The paper can provide a new idea for the joint active and passive optimization study, and improve the energy saving and emission reduction effect in the building energy saving.

Directional Transportation Behavior of Droplets on a Magnetically Responsive Micropillar Array Surface.

Technologies for manipulating droplets have applications in various fields, such as biomedical devices, chemical engineering, water collection, and thermal management. The morphology of magnetically responsive surfaces are modified using magnetic fields for inducing droplet directional rolling and bouncing. Herein, a study on the directional transport of droplets on magnetically responsive surfaces is reported, identifying three movement modes and analyzing the mechanisms influencing the transport behavior. The study explored working fluids with surface tension lower than that of water, achieving the directional transport of 30% ethanol droplets with a maximum transport velocity of 130 mm s-1. The practical applications of the droplets on a modified surface were analyzed, and methods were developed to accelerate droplet mixing. This study explored efficient operations and automation of complex chemical processes.

Drivers of Wolf Activity in a Human-Dominated Landscape and Its Individual Variability Toward Anthropogenic Disturbance.

Wolves (Canis lupus) exhibit contrasted activity patterns along their distribution range. The shift from diurnal to nocturnal habits within and among populations appears to be primarily driven by localized levels of human activity, with ambivalent responses toward such disturbance reported among populations. Yet, the drivers and the underlying individual variability of temporal avoidance patterns toward human remains unexplored. We equipped 26 wolves with GPS-GSM collars, obtaining 54,721 locations. We used step lengths, turning angles, and accelerometer data from recorded locations to infer activity through hidden Markov models (Conners, M. G., T. Michelot, E. I. Heywood, et al. 2021. "Hidden Markov Models Identify Major Movement Modes in Accelerometer and Magnetometer Data From Four Albatross Species." Movement Ecology 9, no. 1: 1-16.). We further explored the probability of activity as a function of a set of proxies of anthropogenic disturbance at different spatial scales and its interaction with different periods of the day by fitting population-level and individual-based hidden Markov models. Wolves were predominantly active during dusk and night, yet variations in activity emerged among individuals across day periods. We did not find clear population-level effects of anthropogenic disturbance predictors, as these were masked by a wide range of individual-specific responses, which varied from positive to negative, with inter-individual variability in responses changing according to different predictors and periods of the day. Our results suggest a non-uniform strategy of wolves in adapting their behavior to human-dominated environments, further underscoring the role of vegetation patches acting as functional refuge cover for buffering the effects of anthropogenic disturbance and boosting the persistence of the species in human-dominated landscapes. This study, for the first time, reveals the individual variability in wolf responses to human disturbance. By fitting hidden Markov models to data from GPS-GSM collars deployed on 26 wolves, we found significant variation between individuals in their responses to different levels of anthropogenic pressure and across different times of day, highlighting a non-uniform strategy for coping with perturbations in human-dominated landscapes. Our findings underscore the diverse behavioral adjustments employed by wolves to persist in these environments and highlight the critical importance of vegetation patches serving as refuge cover.

Functional traits and ecosystem implications in the Multiple Use Marine Protected Area Almirantazgo Sound: A baseline study of scallop banks and benthic communities

Amid escalating environmental challenges confronting marine ecosystems, the proliferation of coastal and marine protected areas (MPAs) has emerged as a pivotal strategy for mitigating biodiversity loss and fostering sustainable resource management. This research advocates for a paradigm shift towards a trait-based approach to assess functional diversity (FD) within MPAs, with a specific focus on the ecologically crucial Austrochlamys natans banks in Parry Bay, MPA Almirantazgo Sound. By surveying 28 invertebrate species across eight phyla, a PCA using fuzzy-coded functional traits revealed five distinct groupings primarily based on feeding, movement, and reproductive modes. Mobile predators and scavengers clustered distinctly from sessile suspension feeders and limited-mobility grazers, indicating a scarcity of mobile predator species in Parry Bay, which impacts the ecosystem's dynamics. FD indices highlighted low functional α-diversity, emphasizing trait redundancy that enhances resilience but relies heavily on a few unique and specialized species. The potential extinction or migration of these species could directly affect unique ecosystem properties. While revealing the resilience of the benthic community, this research underscores its dependence on a handful of species that are crucial for both ecological functions and regional commercial significance. Urgent conservation and management measures are imperative to protect these species and maintain the delicate balance of this ecosystem.

How does digital technology affect export in services?

Based on the comprehensive measures of digital technology and cross-country services trade database, our study empirically examines the impacts of digital technology on export in services. We find that digital technology significantly promotes services export. However, the impact varies in different modes of supply. Digital technology significantly promotes service export in the mode of cross border delivery, consumption abroad, and commercial presence rather than the mode of the natural person movement. Heterogeneous analysis shows that the trade impact of digital technology is more pronounced in developed countries and the countries with higher levels of digital openness. Based on both the empirical analysis and the case studies, three main channels of the enhancement of tradability, the function of digital platforms, and innovation of new trade models are discussed for the influencing mechanisms of digital technology.

The Method of Calculating the Heat Transfer Coefficient in the Heliosystems with Laminar and Transient Modes of Heat Carrier Flow Movement Structured Into Parts

In this study, a new method of choosing classical empirical equations for calculating heat transfer coefficients in the tubes of a shell-and-tube heat exchanger in the transient mode is proposed. This method is based on the fact that the flow is structured into a laminar boundary layer (LBL) zone and a turbulized part, and the heat transfer coefficient is calculated through the transient and turbulent heat conductivity, as well as the average thickness of the LBL and, accordingly, the average thickness of the rest of the coolant flow. At the same time, the key point of this method is the condition that the transient thermal conductivity of the LBL should be lower than the thermal conductivity of the turbulized part. If this condition is not fulfilled, it is concluded that the corresponding classical empirical equation is not suitable for calculating the heat transfer coefficient. A 45% aqueous solution of propylene glycol was taken as a model liquid, which can be widely used in solar collectors, in particular with nanofillers. This coolant is interesting because at a constant speed of V = 0.93 m/s, and the linear size (diameter) of the "live section" of the flow D = 0.021 m in the temperature range of 243–273 K it moves in the laminar mode, in the temperature range of 283–323 K — in transient mode and 333–353 K — in turbulent mode. A new formula is proposed for calculating the coefficient of turbulence of the coolant flow a, the numerical values of which are experimentally found in literary sources only for the air coolant.