Actual Rotation Research Articles

МЕТОД РАСЧЕТА ОПТИМАЛЬНОГО РЕЖИМА ДИСПЕРГИРОВАНИЯ РАСТВОРОВ ПОЛИМЕРНЫХ КОМПОЗИТОВ В ТУРБИННОЙ МЕШАЛКЕ

LSTU has developed a turbine stirrer for mixing and dispersing solutions of polymer nanocomposites designed to restore mounting holes in the body parts of equipment. Formula is proposed for calculation of optimal rotation frequency of turbine mixer, which takes into account structural parameters of mixer and physical properties of nanoparticles, which provides effective mixing of nanoparticles of filler in solution of nanocomposite. An experiment was carried out to assess the adequacy of a mathematical model of the turbine stirrer speed. Experimental turbine agitators of three different sizes were used in the experiment. A solution of elastomer nanocomposite F-40S was used for mixing. The dispersion quality was evaluated by the light transmission coefficient. For each turbine stirrer size, experimental non-linear dependences of the transmittance on the stirrer speed were obtained. After approximation of experimental dependences and taking partial derivatives, their extremes are determined, i.e. actual optimal rotation frequencies for each mixer size: n оф1 = 1325 min-1; nof2 = 1113 min-1;, nof3 = 973 min-1. Then the power consumed by stirrers of various sizes at a speed of 500, 1000 and 1500 min-1 was measured. Further, the values of the circumferential velocity coefficients k were calculated for each stirrer using the measured power values. As the stirrer diameter increases from 34 to 90 mm, the corresponding circumferential velocity factor k increases from 0.9534 to 0.9703, indicating an increase in circumferential flow.Further, according to the proposed formula, using the values of the coefficients of peripheral speeds, the calculated values of the optimal speed for stirrers No. 1, No. 2 and No. 3 were obtained: n op1 = 1307 min-1; nop2 = 1100 min-1;, nop3 = 965 min-1. Analysis of variance showed that the calculated Fischer value does not exceed the table value, which confirms the adequacy of the formula for calculating the optimal speed of the turbine stirrer.

A Prediction Model of Two-Sided Unbalance in the Multi-Stage Assembled Rotor of an Aero Engine

In rotating machinery with a multi-stage assembled rotor, such as is found in aero engines, any unbalance present will undergo unknown changes at each stage when rotating the assembly phases of the rotor. Repeated disassembly and adjustments are often required to meet the rotor’s residual unbalance specifications. Therefore, developing a prediction model of this two-sided unbalance for a multi-stage assembled rotor is crucial for improving the first-time assembly pass rate and assembly efficiency. In this paper, we propose a prediction model of the two-sided unbalance seen in the multi-stage assembled rotor of an aero engine. Firstly, a method was proposed to unify the mass feature parameters of each stage’s rotor into a geometric measurement coordinate system, achieving the synchronous transmission of geometric and mass feature parameters during the assembly process of the multi-stage rotor. Building upon this, a linear parameter equation of the actual rotation axis of the multi-stage rotor was established. Based on this axis, the mass eccentricity errors of the rotor were calculated at each stage, further enabling the accurate prediction of two-sided unbalance and its action phase in a multi-stage rotor. The experimental results indicate that the maximum prediction errors of the two-sided unbalance and its action phase for a four-stage rotor are 9.6% and 2.5%, respectively, when using this model, which is a reduction of 53.0% and 38.1% compared to the existing model.

The Droplet Creeping-Sliding Dynamic Wetting Mechanism on Bionic Self-Cleaning Surfaces.

The dynamic wetting behavior of droplets has been of wide concern due to the hazards of accretion/icing of supercooled droplets on engineering components/systems served in low temperature freezing rain environment; thus, it is urgent to establish the relationship between droplet depinning/removing behaviors and surface characteristics. In this article, the actual rotation conditions of moving components such as wind turbine blades are simulated. The self-cleaning hydrophobic coating surface(S1) and bionic superhydrophobic coating surface(S2) show outstanding droplet removal performance compared to hydrophilic bare steel surface(S0), and the average speed of the droplet removal is increased by 400-500%. The "creeping-sliding" behavior of droplets on self-cleaning coatings is investigated by the change of droplet displacement(ΔD). The effect of the energy storage caused by the droplet creeping process provides initial kinetic energy for the droplet removal. Combined with the experimental data and theoretical model, the critical depinning resistance is calculated. The difference of the wetting interface free energy(ΔEx) during the dynamic wetting process of the droplets on the bionic superhydrophobic self-cleaning surface is researched. And the influence mechanism of the droplet embedded depth(x) on the creeping/sliding behavior in the nanotexture is clarified. Thus, the mechanical criterion of droplet depinning is proposed (the error is about 10%). The results can provide a theoretical basis for the design principle of antifreezing rain coatings on moving components.

Single mask and low voltage electrothermal micromotor

This paper introduces a single-mask-and-low-voltage electrothermal micromotor driven by four symmetrical V-shaped actuators and ratchet mechanism. The 2.5 mm-diameter micromotor has been fabricated successfully by using silicon on insulator (SOI) wafers and SOI-MEMS technology. The play of micromotor is tested under microscope and indicated that it operates quite smoothly. The actual rotation speeds (rpm) of the micromotor are examined with the driving frequencies range from 1 Hz to 15 Hz at a driving voltage of 12.5 V and compared with the calculation. Experimental results show that the theoretical and measured angular speeds are quite close while the applied frequencies are lower or equal to 10 Hz.

Data-driven intelligent prediction of TBM surrounding rock and personalized evaluation of disaster-inducing factors

With the widespread application of tunnel boring machines (TBM) in underground tunnel construction, the accurate and real-time identification of geological indicators has become a key factor for ensuring construction safety. In this study, we introduced the nomogram method into the field of civil engineering for the first time to predict surrounding rock grades. Against the backdrop of a major water conservancy project in China, an in-depth analysis of construction data from the ascending phase was conducted to establish the relationship between surrounding rock grade predictions and key construction parameters. Compared with traditional models, the nomogram method has shown advantages in terms of prediction accuracy. Furthermore, by providing a personalized scoring mechanism for specific construction data, the nomogram method not only achieves the real-time prediction of rock grades but also clearly reveals the dynamic relationships between input parameters and rock grades, clarifying the entire prediction process. We identified the main factors related to rock grade prediction among TBM construction parameters, including the slurry conveyor belt speed, jacking pressure, cutterhead torque, cutterhead thrust, thrust pressure, and actual rotation speed. The training process revealed that the nomogram prediction model achieved optimal performance with seven input parameters, balancing accuracy and training time. According to the prediction results, the nomogram model’s area under the curve index is 0.92, providing greater accuracy than the traditional random forest model (0.89). Therefore, this study enhances the transparency and interpretability of model predictions by providing personalized assessments of construction parameters for predicting surrounding rock grades, overcoming the black-box issue of existing prediction methods and offering a novel and effective tool for rock grade prediction.

Quantification of Gravitational Effects on Nasal Tip Geometry

Introduction: It is widely accepted in plastic surgery that patient positioning can affect the geometry of the nasal tip due to downward gravitational forces. However, empirical data supporting this principle is lacking. The primary objective of this study is to quantify gravitational effects on nasal tip geometry by calculating changes in tip rotation and projection between the supine and upright positions. This analysis will help further assess whether gravity affects the actual positional rotation of the nasal tip or if its impact is solely relative to neighboring landmarks. Methods: This study is a prospective case series that obtains upright and supine nasal measurements in 20 subjects. The nasolabial, nasofrontal, and columellar-facial angles, as well as the Goode, Crumley, Simon, and Powell ratios are used to calculate nasal tip rotation and projection changes. Results: Mean nasolabial angle demonstrated a statistically significant tip derotation of 3.2° in the upright position relative to supine. Mean nasofrontal angle and mean columellar-facial angle did not significantly differ between positions. The nasal tip appeared relatively less projected in the upright position using the Simon and Crumley methods, whereas no significant difference was seen with the Powell and Goode methods. Conclusion: Gravity can influence the apparent nasal tip geometry by altering lip position and length, but it does not impact the true nasal tip geometry when the upper lip is excluded as a reference point.

Assessment of Surgical Accuracy in Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea: A Preliminary Analysis.

This retrospective study aimed to: (1) investigate the surgical accuracy of maxillomandibular advancement (MMA) in obstructive sleep apnea (OSA) patients, with a specific focus on maxillary and mandibular advancement and counter-clockwise rotation and (2) investigate the correlation between the amount of achieved advancement and the reduction in the relative apnea hypopnea index (AHI). Sixteen patients, for whom a three-dimensional virtual surgical plan was generated preoperatively and a computed tomography scan (CT) or cone-beam computer tomography (CBCT) was acquired postoperatively, were included. The postoperative CT or CBCT was compared to the virtual surgical plan, and differences in the mandibular and maxillary advancement and counter-clockwise rotation were assessed. Maxillary and mandibular advancement (median 3.1 mm, p = 0.002 and 2.3 mm, p = 0.03, respectively) and counter-clockwise rotation (median 3.7°, p = 0.006 and 4.7°, p = 0.001, respectively) were notably less than intended. A significant correlation was found between the planned maxillary advancement and the difference between the planned and actual maxillary advancement (p = 0.048; adjusted R2 = 0.1979) and also between the planned counter-clockwise rotation and the difference between the planned and actual counter-clockwise rotation for the mandible (p = 0.012; adjusted R2 = 0.3261). Neither the maxilla-first nor the mandible-first surgical sequence proved to be superior in terms of the ability to achieve the intended movements (p > 0.45). Despite a significant reduction (p = 0.001) in the apnea hypopnea index (AHI) from a median of 62.6 events/h to 19.4 events/h following MMA, no relationship was found between the extent of maxillary or mandibular advancement and AHI improvement in this small cohort (p = 0.389 and p = 0.387, respectively). This study underlines the necessity for surgeons and future research projects to be aware of surgical inaccuracies in MMA procedures for OSA patients. Additionally, further research is required to investigate if sufficient advancement is an important factor associated with MMA treatment outcome.

Single-pixel detecting of rotating object using Zernike illumination

In this paper, a single-pixel imaging technique based on Zernike illumination is firstly introduced to detect rotating object. By measuring the specific Zernike moments through a single-pixel detector, the rotation angle of rotating object can be obtained. This method requires only four differential Zernike patterns to illuminate a rotating object in one frame. And the Zernike moments can be calculated from the corresponding reflected intensities collected by the single-pixel detector. Then the rotation angle can be calculated from the phase change of Zernike moments due to the rotation invariant. By theoretical simulation and experimental demonstration, the Zernike moments of the targets are successfully obtained through single-pixel imaging system. The rotation angles are calculated from the measured Zernike moments and agree well with the actual rotation angles. The errors of simulated rotation angle are below 1°. And the RMSEs of the experimental results are below 3° for binary images and below 4° for gray images. The proposed scheme provides a new method for applications on detecting rotating object.

Automation in solid state NMR

Automation in solid state NMR (ssNMR) requires appropriate hardware, from rotor loading mechanisms over highly stable rf-transmitters and probe circuitry to automatic tuning and matching capabilities including automatic magic angle adjustment for ssNMR probes. While these hardware capabilities are highly desirable and are, to various degrees, provided by manufacturers, we focus herein on automating experiment setup using radio frequency (rf) fields, which are key parameters in solid state NMR experiments. Specifically, these include spinlock fields during cross polarization (CP), or rf-fields for homo- or heteronuclear spin recoupling or decoupling. Often, these fields have specific relationships to the magic angle spinning (MAS) frequency. Relying on a well-maintained spectrometer, the experiment setup shifts from traditionally required optimization of rf-power values for each element of an experiment sequence to automatically setting all parameters correctly without any need for optimization. The proposed approach allows executing an experiment by reading its rf-amplitude requirements based on the actual MAS rotation frequency just before starting data acquisition, while all other hardware-related parameters are automatically provided through global tables and scripts. Under modest MAS frequencies, no further rf-power optimization is required while providing optimal sensitivity of better than 90% of the optimal signal to noise. Any optional parameter optimization relates only to adjusting rf-nutation frequencies to the requirements of the sample and the sample rotation frequency rather than the spectrometer hardware. Fast MAS CP experiments with MAS frequencies above 40 kHz require a semi-automated setup by optimizing Hartmann-Hahn (HH) matched rf-fields that are synchronously varied relative to the MAS-frequency. This allows for a significant reduction of setup steps by up to one order of magnitude for such experiments, avoiding the traditional grid search for optimal CPMAS conditions. The approach presented here can also be applied to decoupling or recoupling sequences, requiring rotor synchronized rf-fields, reducing the setup to a few steps addressing the spin system’s properties rather than the spectrometer hardware. Our approach permits automating all basic solid state NMR experiments for high throughput analytical tasks.

Failure analysis and retrofitting of reinforced concrete beams in existing moment resisting frames

During the structure lifetime, the design loads can modify because of a changing in the use destination. In common practice, any architectural change of existing buildings, which modifies the magnitude of loads, requires the evaluation of the load-carrying capacity of structural members. To this aim a nonlinear analysis considering the rotation capacity of critical regions until the failure of the structure can be advantageous compared to a simple elastic analysis. Plastic deformations of ductile elements allow for attaining a more accurate evaluation of the ultimate load, once the strength of brittle mechanisms has been averted. Exploiting the actual rotation capacity of critical regions, where plastic hinges form, this paper presents new analytical closed-form equations to evaluate the ultimate load and the failure mode of an interior span of a multi-span moment resisting frame, as impacted by the strength of beam–column joints and the elastic and post-elastic structural response of adjacent elements. Taking advantage of derived equations, a retrofitting design procedure to identify the proper structural strengthening of critical regions is proposed. The accuracy of the method is checked through a comparison with numerical results. The procedure represents a new useful tool for engineers for the local strengthening of existing reinforced concrete buildings.

Visual feedback manipulation in virtual reality to influence pain-free range of motion. Are people with non-specific neck pain who are fearful of movement more susceptible?

Movement-evoked pain may have a protective or learned component, influenced by visual cues which suggest that the person is moving towards a position that may be perceived as threatening. We investigated whether visual feedback manipulation in virtual reality (VR) had a different effect on cervical pain-free range of motion (ROM) in people with fear of movement. In this cross-sectional study, seventy-five people with non-specific neck pain (i.e., neck pain without a specific underlying pathology) rotated their head until the onset of pain, while wearing a VR-headset. Visual feedback about the amount of movement was equal, 30% smaller or 30% larger than their actual rotation. ROM was measured using the VR-headset sensors. The effect of VR manipulation in fearful (N = 19 using the Tampa Scale for Kinesiophobia (TSK) and N = 18 using the Fear Avoidance Beliefs Questionnaire-physical activity (FABQpa)) and non-fearful (N = 46; non-fearful on both scales) people was compared using mixed-design ANOVAs. Fear of movement, influenced the effect of visual feedback manipulation on cervical pain-free ROM (TSK: p = 0.036, ղp2 = 0.060; FABQpa: p = 0.020, ղp2 = 0.077); a greater amplitude of pain-free movement was found when visual feedback reduced the perceived rotation angle compared to the control condition (TSK: p = 0.090, ղp2 = 0.104; FABQpa: p = 0.030, ղp2 = 0.073). Independent of the presence of fear, visual feedback manipulation reduced the cervical pain-free ROM in the overstated condition (TSK: p< 0.001, ղp2 = 0.195; FABQpa: p<0.001, ղp2 = 0.329). Cervical pain-free ROM can be influenced by visual perception of the amount of rotation and people with fear of movement seem to be more susceptible to this effect. Further research in people with moderate/severe fear is needed to determine whether manipulating visual feedback may have clinical applicability to make patients aware that ROM may be influenced more by fear than tissue pathology.

Agricultural machinery photoelectric automatic navigation control system based on back propagation neural network

So as to study the influence of speed factors on the stability of tractor automatic navigation system, combined with neural network control theory, the author proposed a dual-objective joint sliding mode control method based on lateral position deviation and heading angle deviation, using back propagation neural network to establish two-wheel tractor-path dynamics model and straight-line path tracking deviation model, the overall system simulation was carried out by using Matlab/Simulink, and the reliability of the control method was verified. The experimental results showed: when the tractor was tracked with the automatic control of linear path under the condition of the variable speed, the maximum deviation of the lateral position deviation was 12.7cm, and the average absolute deviation was kept within 4.88cm; the maximum deviation of the heading angle deviation was 5°, and the average absolute deviation was kept within 2°; the maximum value of the actual rotation angle was 3.13°, and the standard deviation of the fluctuation was within 0.84°. Under the condition of constant speed and variable speed, using the joint sliding mode control method designed by the author, the dual-objective joint control of lateral position deviation and heading angle deviation could be realized, the controlled overshoot was small, the controlled deviation was small after reaching a stable state, and the adaptability to speed factors was strong, which basically could meet the accuracy requirements of farmland operations.

Deep Deterministic Policy Gradient and Active Disturbance Rejection Controller based coordinated control for gearshift manipulator of driving robot

In order to improve the shift precision of the gearshift manipulator, a coordinated control method for the gearshift manipulator based on the Deep Deterministic Policy Gradient (DDPG) and Active Disturbance Rejection Controller (ADRC) is proposed. Firstly, the kinematic model and dynamics model of the gearshift manipulator are established. Secondly, a coordinated control strategy is proposed to solve the target rotation angle of the servo motor, so as to deal with the nonlinear trajectory problem caused by the mechanical decoupling strategy. Then, an ADRC-based controller and a DDPG-based parameter adjuster are proposed. A DDPG model is established to adaptively adjust the control parameters of ADRC through the target rotation angle, actual rotation angle and rotation angle error. Finally, the theoretical stability proof and experimental verification of the proposed method are conducted. The test results show that the mean absolute error of the proposed method is 34% and 18% lower than that of ADRC and fuzzy PID methods. It shows the effectiveness of the method.

Effects of subsidy and regulation policy on soil and water resources of cotton planted lands in Harran Plain, Turkey

Cotton (Gossypium hirsutum L.) provides essential raw material used in the textile, feed, and vegetable oil sectors. Therefore, it is a strategic crop for agricultural, economic, and political strategies around the world. Accurate monitoring of the changes in the cotton production patterns is crucial for decision-makers. Turkey is among the top ten cotton producers and ranks fourth in the world for cotton imports. One third of the total cotton production in Turkey comes from the southeastern Anatolia region of the country. This study analyzed the impact of subsidy and regulation policies on fluctuations in cotton production areas and soil and water quality in Harran Plains, southeastern Anatolia region Turkey. Time-series (between 2016 and 2021) satellite images were utilized to determine actual crop rotation in the study area. Turkish Government implemented a new rule for crop subsidies in 2020 which stated that a farmer will be eligible for subsidy for two consecutive years; however the subsidy will not be paid if the same crop is planted in the third year. Cotton was cultivated in 83 % of the Harran plains prior to new subsidy regulation, which decreased to 26 % after the new regulation. Sudden decrease in cotton cultivation area clearly indicated that farmers need public support to cover the costs in agricultural production. The Gross Production Value (BPV) for each crop was calculated to determine the impact of subsidy regulation on economic value of crops in the rotation.The GPV in 2020 was 2.903,7 $ ha−1 that was 33.6 % and 20.5 % lower than 2019 and 2021, respectively. The results indicated that crop subsidies significantly altered the crop selection behavior of farmers. Water requirement of crops in rotation between 2016 and 2021 was calculated to assess the effects of subsidy changes on water consumption. Cotton cultivation over a large part of the plains during the same season caused excessive water consumption, rise in groundwater level over time, soil salinity and severe water erosion. However, cotton cultivation area as well as water consumption in Harran plain new significantly decreased with the new subsidy regulation; therefore, water consumption in 2020 was the lowest among the time frame evaluated. Total sediment losses through surface runoff from the Harran Plain was estimated as 0.83 tons ha−1 per year. The results revealed that subsidies exert significant impacts on the gross production value in the region, amount of irrigation water consumed, and quality of soil and water resources in addition to the impact on the decision of farmers for crop selection.

A novel VAWT passive flow control numerical and experimental investigations: Guided Vane Airfoil Wind Turbine

Guided Vane Airfoil was introduced as a novel passive flow control approach to control the dynamic stall of the Darrieus vertical axis wind turbine. ANSYS fluent SW tool has been used to solve the unsteady Reynolds-averaged Navier-Stokes equations with an SST k-ω turbulent model to investigate the effect of the Guide Vane on the aerodynamics performance of NACA 0018 airfoil. Furthermore, a parametric study has been conducted to determine the optimum vane geometry to improve the airfoil aerodynamics efficiency. Based on the 2D airfoil investigation results, the best configuration of the vane and airfoil combination have been used to numerically study the dynamic stall control of one airfoil through actual vertical axis wind turbine rotation. In addition, the vane angle relative to the airfoil has been studied in the turbine CFD investigation. For the sake of validating the new concept, a wind turbine test rig has been constructed to, experimentally, investigate the performance of the Guided Vane Airfoil wind turbine. The performance of the original wind turbine has been firstly measured and then the Guided Vane is added to the turbine blades. Based on the experimental data, about 26% increase in the maximum power output has been measured from the Guided Vane airfoil wind turbine.

Maximum Power Point Tracking Control for Non-Gaussian Wind Energy Conversion System by Using Survival Information Potential.

In this paper, a wind energy conversion system is studied to improve the conversion efficiency and maximize power output. Firstly, a nonlinear state space model is established with respect to shaft current, turbine rotational speed and power output in the wind energy conversion system. As the wind velocity can be descried as a non-Gaussian variable on the system model, the survival information potential is adopted to measure the uncertainty of the stochastic tracking error between the actual wind turbine rotation speed and the reference one. Secondly, to minimize the stochastic tracking error, the control input is obtained by recursively optimizing the performance index function which is constructed with consideration of both survival information potential and control input constraints. To avoid those complex probability formulation, a data driven method is adopted in the process of calculating the survival information potential. Finally, a simulation example is given to illustrate the efficiency of the proposed maximum power point tracking control method. The results demonstrate that by following this method, the actual wind turbine rotation speed can track the reference speed with less time, less overshoot and higher precision, and thus the power output can still be guaranteed under the influence of non-Gaussian wind noises.

DESIGN OF SCREW CONVEYOR MACHINE TO IMPROVE THE EFFECTIVENESS OF SALT FARMERS' WORK

AbstractSalt is one of the complements of food that we often encounter in everyday life. To facilitate in the manufacture of salt, there needs to be automatic tools so as to improve effective work results. Screw Conveyor is one type of material transfer aircraft that is the principle of thread in the process of working with a simple design. Screw conveyor consists of thread pipes arranged on pipes or shafts that rotate in a fixed tube then moved using a motor. Components used in screw conveyors include: electric motors, reducers, shafts, bearings, troughs, and screws. The material used is stainless steel 316L.This research contains the design of screw conveyor machines using autodesk inventor application 2015, in this design the material uses SS316L plates with a thickness of 2 mm, then for frames / frames using elbow iron with a thickness of 4 x 40 mm and 5 x 50 mm. The results obtained from this study are, the capacity obtained is 1711 ft3 / hr. with the number of screw leaves 23, pitch 150, it produces the total power needed to rotate this screw conveyor by 2 HP with an actual conveyor rotation speed of 38.2 rpm.

DEVELOPMENT OF A MARKERLESS OPTICAL MOTION CAPTURE SYSTEM BY AN ACTION SPORTS CAMERA FOR RUNNING MOTION

A marker-based optical motion capture system is often used to obtain the kinematics parameters of a running analysis. However, the attached marker could affect the participant's movement, and the system is costly because of the exclusive cameras. Due to its drawbacks, the present research aimed to develop an affordable markerless optical motion capture system for running motion. The proposed system used an action sports camera to acquire the running images of the participant. The images were segmented to get the silhouette of the participant. Then, a human body model was generated to provide a priori information to track participants' segment position. The subsequent procedure was image registration to estimate the pose of the participant's silhouette. The transformation parameters were estimated by particle swarm optimization. The optimization output in the form of the rotation angle of the body segment was then employed to identify right or left lower limbs. To validate the results of the optimization, a manual matching was conducted to obtain the actual rotation angle for all body segments. The correlation coefficient between the rotation angle from image registration and the actual rotation angle was then evaluated. It was found that the lowest correlation coefficient was 0.977 for the left foot. It implies that the accuracy of the developed system in the present work is acceptable. Furthermore, the results of the kinematics analysis have good agreement with the literature. Therefore, the developed system, not only yields acceptable running parameters, but also affordable since it uses an action sports camera and easy to use.

Orientation Comes First: Becoming Aware of Spatial Disorientation Interferes with Cognitive Performance.

Previous research has shown that experiencing motion stimuli negatively impacts cognitive performance. In the current study, we investigate whether this impact relates to Type-II spatial disorientation (SD), to motion stimulus magnitude, or to an interaction of these factors. Stimuli for participants (n = 23) consisted of Earth-vertical yaw rotations on a rotating chair in a completely darkened room. In the surprise condition, the stimulus started with subthreshold acceleration, followed by suprathreshold deceleration to a non-zero velocity, inducing a sensation of rotation that is opposite to the actual rotation revealed when the lights were switched on. In the no-surprise condition, the same changes in velocity were used, but starting from (almost) zero velocity, which induced a sensation of rotation in the same direction as the actual rotation. Participants performed a self-paced arithmetic task and measurement of their cognitive performance started after the environment was revealed. Stimulus magnitude was operationalized through higher or lower peak suprathreshold deceleration. The results revealed that counting speed decreased significantly when participants were surprised, constituting a large effect size. The proportion of counting errors likewise increased significantly when participants were surprised, but only in the high-magnitude condition. The findings suggest that surprise caused by the recognition of SD has an involuntary disruptive effect on cognition, which may impact performance of piloting tasks. These results are relevant when modeling motion stimuli effects on performance, and when developing SD awareness training for pilots.

PENCEGAHAN DAN SIMULASI DETEKSI DINI VERTIGO DI MESJID BAITURRAHMAN LEUWISARI

Vertigo is a sensation of movement from the body like turning without actual rotation. Vertigo is not always caused by a dangerous disease, but in the long term and if not treated immediately vertigo will cause some adverse effects on quality of life to death. This counseling activity aims to introduce the concept of vertigo, signs and symptoms and practice ways to recognize and eliminate the symptoms of vertigo to the Aisyiyah women's group in Leuwisari sub-district. The outreach activities were carried out by way of explanation and discussion on 65 members of Aisyiyah in the Leuwisari sub-district at the Baiturrahman mosque on October 4, 2019. Before and after the counseling, participants were given a questionnaire to evaluate the activities as a measure of the success of the activity. In this health education activitites the participants of the activity gained increased knowledge compared to before the implementation of health education was given. The results of this activity showed that 62% of participants gave a very good assessment and 21% gave a good level of health education activities about vertigo. The author suggests that this activity can be carried out routinely to community groups by the local public health center.