INFLUENCE OF ACOUSTIC PRESSURE WAVE ON THE MOVEMENT OF THE UNDERWATER

The forced movement of the submarine under the action of an acoustic pressure wave at rectilinear and uniform movement of the device is analyzed. The analysis of the dynamics of translational movement of the hull under the action of an acoustic pressure wave in an ideal environment, which makes it possible to assess the physical properties of the environment and the elastic properties of the outer hull on the value of the maximum movement of the submarine. It is proved that if the total pressure pulse is limited, then the water particles will receive certain displacements and it can be expected that under these conditions the displacement of the submarine will be determined. The results of the analysis make it possible to conduct a comparative analysis of the translational movement of the submarine under the action of an acoustic pressure wave, taking into account the characteristics of the moving medium, more precisely, taking into account the viscosity of the real medium

Reducing Cybersickness in 360-Degree Virtual Reality

Despite the technological advancements in Virtual Reality (VR), users are constantly combating feelings of nausea and disorientation, the so-called cybersickness. Cybersickness symptoms cause severe discomfort and hinder the immersive VR experience. Here we investigated cybersickness in 360-degree head-mounted display VR. In traditional 360-degree VR experiences, translational movement in the real world is not reflected in the virtual world, and therefore self-motion information is not corroborated by matching visual and vestibular cues, which may trigger symptoms of cybersickness. We evaluated whether a new Artificial Intelligence (AI) software designed to supplement the 360-degree VR experience with artificial six-degrees-of-freedom motion may reduce cybersickness. Explicit (simulator sickness questionnaire and Fast Motion Sickness (FMS) rating) and implicit (heart rate) measurements were used to evaluate cybersickness symptoms during and after 360-degree VR exposure. Simulator sickness scores showed a significant reduction in feelings of nausea during the AI-supplemented six-degrees-of-freedom motion VR compared to traditional 360-degree VR. However, six-degrees-of-freedom motion VR did not reduce oculomotor or disorientation measures of sickness. No changes were observed in FMS and heart rate measures. Improving the congruency between visual and vestibular cues in 360-degree VR, as provided by the AI-supplemented six-degrees-of-freedom motion system considered, is essential for a more engaging, immersive and safe VR experience, which is critical for educational, cultural and entertainment applications.

A successful placement of the left ventricular lead for the cardiac resynchronization device using the orthodromic snare technique: clinical case

Background: The main aim of Cardiac Resynchronization Therapy (CRT) is a positive response of the patient, particularly, reduction of the symptoms and improvement of the heart contractility, that can be reached in 5070% of patients. The possibility of appropriate positioning the left ventricular (LV) lead is of great importance for the response to CRT. Certain instruments and technical approaches are used for the placement of the LV lead. Here, we describe the use of the orthodromic snare technique, which is quite rare in practice, but allows one to overcome some anatomical obstacles. Clinical case description: Patient A., suffering from the heart failure with a low ejection fraction and left bundle branch block, was admitted to the hospital for CRT implantation. Before the operation, all the necessary routine instrumental and laboratory diagnostics was performed. During the operation, venography of the cardiac veins revealed unsuitability of the lateral cardiac vein for the placement of the LV lead due to its very small diameter. The posterolateral vein was suitable for the LV lead implantation but still had some anatomical difficulties: an acute angle of inflow and local stenosis in the proximal segment. During the procedure, the following techniques were used without success: positioning the LV lead by a simple translational movement forward, a subselective catheter, introduction of several coronary guides in order to smooth out the acute angle of inflow. These circumstances warranted the use of the orthodromic snare technique for a successful LV lead placement. Conclusion: This clinical case illustrates the possibility of a safe and effective use of the orthodromic snare technique for LV lead implantation. Such anatomical difficulties as a small diameter, acute angle of inflow, local stenosis have also been illustrated and discussed.

Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

Correlated Dynamics in Ionic Liquids by Means of NMR Relaxometry: Butyltriethylammonium bis(Trifluoromethanesulfonyl)imide as an Example

1H and 19F spin-lattice relaxation experiments have been performed for butyltriethylammonium bis(trifluoromethanesulfonyl)imide in the temperature range from 258 to 298 K and the frequency range from 10 kHz to 10 MHz. The results have thoroughly been analysed in terms of a relaxation model taking into account relaxation pathways associated with 1H–1H, 19F–19F and 1H–19F dipole–dipole interactions, rendering relative translational diffusion coefficients for the pairs of ions: cation–cation, anion–anion and cation–anion, as well as the rotational correlation time of the cation. The relevance of the 1H–19F relaxation contribution to the 1H and 19F relaxation has been demonstrated. A comparison of the diffusion coefficients has revealed correlation effects in the relative cation–anion translational movement. It has also turned out that the translational movement of the anions is faster than of cations, especially at high temperatures. Moreover, the relative cation–cation diffusion coefficients have been compared with self-diffusion coefficients obtained by means of NMR (Nuclear Magnetic Resonance) gradient diffusometry. The comparison indicates correlation effects in the relative cation–cation translational dynamics—the effects become more pronounced with decreasing temperature.

Teleoperation Interface for sAFAM, a Solid Articulated Four Axes Microrobot

The sAFAM is a novel mm-size microrobot built using MicroElectroMechanical Systems (MEMS) technology. It consists of a monolithically fabricated microrobotic arm assembled onto four in-plane actuators, capable of moving along four degrees of freedom, including translational movement in X and Y axes as well as pitch and yaw. In this paper, several design modifications were proposed to increase movement precision, stability, and controllability to the sAFAM tip. An interface is developed to assist a human operator accurately position the microrobot tip during nano-object handling. A Python-based graphical user interface (GUI) was programmed to make it intuitive for an operator to use and obtain required tip precision under a microscope. Experimental results demonstrate the functionality of the proposed control solution, and the tip motion resolution using microscope images of the microrobot tip under 20x magnification during operation. The hardware and software requirements for the proposed experimental setup and control platform are discussed in detail.

Improving the productivity of the cutter-loader

The task of the conducted research is to determine the dependence of the productivity of the cutter-loader on the parameters of the engagement of the teeth of the wheel-rack mover of chainless haulage systems. To solve this problem, the dependence of the influence of the parameters of the toothed gearing of the wheel-rack mover of the chainless haulage system on the performance of the cutter-loader is found using the mathematical apparatus. The equation of the balance of the power of the cutter-loader is made, taking into account the mechanical energy input for the destruction of the formation, loading the destroyed mineral mass onto the face conveyor (relevant for cutter-loaders for excavating thin flat-lying seams) and moving the cutter-loader. The theoretical performance of the cutter-loader depends on the redistribution of the mechanical energy of the drive electric motor, aimed at the destruction of the mineral and the translational movement of the cutter-loader. The correlation of the productivity of the cutter-loader with the parameters of the engagement of the teeth of the wheel-rack mover of chainless haulage system systems is revealed. The obtained dependences of the performance of the cutter-loader allow assessing the degree of influence of the parameters of the toothed gearing of the mover of the chainless haulage system on the performance of the cutter-loader. The possibility of increasing the minute productivity of the cutter-loader by up to 20% when using a wheel-rack mover of a chainless haulage system with an optimal tooth profile is established.

Stabilization Control of Inverted Two-Wheeled Luggage Transport Vehicle Using a Kalman Filter-Based Disturbance Observer

In addition to the declining birthrate and aging population in Japan, there has been a recent decrease in its total population. This threatens to exacerbate a shortage in labor force, which could trigger an increase in the luggage transport costs of transportation companies or the service industry. The demand for inverted two-wheeled luggage transport vehicles has been increasing steadily owing to their high mobility, compactness, affordability, and pivotal turnability. However, owing to their statical instability, these vehicles are limited. Accordingly, stability can be improved in these systems by configuring a spreading system and applying a disturbance observer based on a Kalman filter. The application of a Kalman filter enables us to estimate the disturbance in which the error between the true and estimated values is the least mean square. Furthermore, we validated the efficiency of the proposed method via its translational movement, turning angle control, and load-loading/unloading experiments using various loads.