Maximum Horizontal Distance Research Articles

A repeated jumping solution based on the bistable film structure for film-structured miniature soft robots

Abstract Miniature film-structured robots achieved remarkable locomotion performance and various applications. The integration of a jumping function could empower existing film-structured terrestrial robots to conquer complex terrains. However, current repeated jumping mechanisms for miniature soft robots are often constrained to specific materials and mechanical configurations, rendering them incompatible with film-structured robots. A solution that effectively addresses these limitations remains absent in the field. This work introduces an electrically actuated solution for repeated jumping in miniature soft robots, utilizing a bistable film structure coupled with a numerical two-rod model. The bistable film structure integrates a flexible film, polydimethylsiloxane (PDMS) linear spring, and a shape memory alloy spring to achieve repeated jumping motion through snap-through buckling. The numerical model is employed to optimize the spring parameters, tailoring the structure to the specific properties of the target robot. To demonstrate the practicality of this solution, the bistable film structure is seamlessly integrated into an existing fast-steering insect robot, which previously lacks jumping capabilities. By customizing PDMS spring design based on the robot body’s dimensions and stiffness, the prototype robot, measuring 23 × 16 × 8 mm3 in size and 120 mg in weight, demonstrates repeated jumping ability with a maximum horizontal jumping distance of 11.8 cm (5.1 body lengths), a jumping height of 3.8 cm (4.7 body heights) and a jumping frequency of 0.1 Hz. The robot traverses a 43 cm-long road with half walls and trench obstacles in 41 s. This work presents the bistable film structure’s potential as a repeated jumping solution for film-structured robots, enhancing their obstacle-crossing abilities and expanding their applicability in complex environments.

The Marginal Effect and LSTM Prediction Model under the Chinese Solar Greenhouse Film

The solar greenhouse is a significant agricultural facility in China. It enables the cultivation of crops during periods that do not coincide with the natural growing season, thus alleviating the pressure on the supply of fruits and vegetables during the winter months. The primary rationale behind the necessity of greenhouse cultivation lies in the fact that the temperature conditions conducive to optimal crop growth can be precisely replicated within this controlled environment. However, it is important to acknowledge that a distinct low-temperature area persists under the film during the overwintering period, with the precise delineation of its boundaries and distribution patterns remaining uncertain. In order to investigate the characteristics of the temperature distribution within the marginal region under the solar greenhouse film, experimental studies, CFD simulations, and LSTM prediction models were employed. The results of these studies indicate that, during the overwintering period, a low-temperature region was observed with approximately equal temperatures near the film membrane. The maximum horizontal distance from the south-side bottom corner was 6130 mm, while the minimum height from the ground was 600 mm. The lowest temperature in the low-temperature region was 4 °C, and the maximum observed temperature difference within the same period in different months was 1 °C. Additionally, a region of elevated temperatures was observed under the film. The lowest temperature in this region was 36.7 °C, and the highest temperature point was within the optimal range for crop growth. The CFD numerical simulation results were consistent with the actual observations, and the LSTM prediction model demonstrated high reliability. The findings of this study offer a theoretical foundation for the distribution of high and low temperatures in solar greenhouses. Furthermore, the developed prediction model provides the necessary buffer time for control, thus enhancing the efficiency of greenhouse cultivation.

Evaluating Multimodal Techniques for Predicting Visibility in the Atmosphere Using Satellite Images and Environmental Data

Visibility is a measure of the atmospheric transparency at an observation point, expressed as the maximum horizontal distance over which a person can see and identify objects. Low atmospheric visibility often occurs in conjunction with air pollution, posing hazards to both traffic safety and human health. In this study, we combined satellite remote sensing images with environmental data to explore the classification performance of two distinct multimodal data processing techniques. The first approach involves developing four multimodal data classification models using deep learning. The second approach integrates deep learning and machine learning to create twelve multimodal data classifiers. Based on the results of a five-fold cross-validation experiment, the inclusion of various environmental data significantly enhances the classification performance of satellite imagery. Specifically, the test accuracy increased from 0.880 to 0.903 when using the deep learning multimodal fusion technique. Furthermore, when combining deep learning and machine learning for multimodal data processing, the test accuracy improved even further, reaching 0.978. Notably, weather conditions, as part of the environmental data, play a crucial role in enhancing visibility prediction performance.

Estimating, appraising and establishing blast exclusion zone at Huni pit - A case study

The issue of accidental flyrock has the tendency to develop safety concerns for commuters around the main public road as mining progressed from 960 ​m reduced level (RL) to 912 ​m RL at Huni pit in Ghana. An evaluation was carried out using empirical models and an artificial neural network to assess and determine the safest blast exclusion zone. The calculations showed that the flyrock could travel a maximum of 220 ​m and 277.45 ​m horizontally for blast hole diameters of 115 ​mm and 127 ​mm, respectively, with the same stemming length of 2.0 ​m. The distances to the public road are much farther than these projected maximum horizontal distances. An artificial neural network (ANN) was also employed to predict the flyrock distance and it was found that the ANN model has the best root mean squared error (RMSE) value of 0.0012 and the highest coefficient of determination (R2) value of 0.99 for the flyrock throw prediction. Hence, the blast exclusion zone has been reduced to 500 ​m all around the pit from the pit crest satisfying the recommendation suggested by the Minerals Commission of Ghana. With the new blast exclusion zone, travelling from Damang through Akyempim to Twifo Praso, Takoradi, Cape Coast, and Accra during blasting times is no longer a bother.

Analysis and prediction of hydrogen-blended natural gas diffusion from various pipeline leakage sources based on CFD and ANN approach

The influences of pipeline leakage source types on the hazard area distribution caused by accidental hydrogen-blended natural gas leakage are still the focus of gas leakage accidents. Three types of pipeline leakage sources are discussed in this study. Namely, the gas in the vertical pipeline flows from top to bottom, and the leakage orifice is in the pipeline wall; the gas in the vertical pipeline flows from bottom to top, and the leakage orifice is in the pipeline wall; the leakage orifice is in the horizontal pipeline end. The common feature of the above three pipeline leakage sources is that the normal of leakage orifice is parallel to the horizontal plane. The differences in the flow field distribution of hydrogen-blended natural gas released from three pipeline leakage sources are compared through numerical simulation. The effect of various factors on the jet centerline, concentration decay, and maximum horizontal diffusion distance of hydrogen-blended natural gas released from three pipeline leakage sources are analyzed. The predictive models of hydrogen-blended natural gas's maximum horizontal diffusion distance in three pipeline leakage sources under multi-factor coupling are established through a backward propagation neural network (BPNN). Results show that the angle between the gas flow direction in the pipeline and the normal of the leakage orifice, and the background step flow cause differences in the concentration field near the leakage orifice from the three pipeline leakage sources at the same working conditions. In the near-field region, the leakage orifice diameter has the most significant influence on the jet centerline of three hydrogen-blended natural gas jets among three factors. The concentration decay rate of gas released from the horizontal pipeline end is greater than that of gas released from the other two pipeline leakage sources. With the increase of volumetric flow rate, the maximum horizontal diffusion distances of methane released from three pipeline leakage sources all increase, while the maximum horizontal diffusion distances of hydrogen released from three pipeline leakage sources have little change. The predictive models of the maximum horizontal diffusion distance of hydrogen-blended natural gas released from three pipeline leakage sources are established through BPNN. The maximum horizontal hazard distances of the new working conditions are predicted, and the predicted results are in good agreement with the numerical simulation results. This investigation has guiding value for fast and accurate prediction of flammable gas hazard areas.

Effects of Drip Tape Layout and Flow Rate on Water and Nitrogen Distributions within the Root Zone and Summer Maize Yield in Sandy Tidal Soil

Drip tape layout and flow rate are crucial variables that impact the effects of drip fertigation. To investigate the influence of drip tape layout and flow rate on the soil water and nitrogen transport in summer maize in sandy tidal soil, field experiments were conducted for two years. Two drip tape layouts were set: one tape serving for two crop rows (N) and one tape serving for each crop row (E), with two levels of drip flow rate, i.e., high (2 L/h; H) and low (1.3 L/h; L). The results show that under the same drip tape layout, the lower the drip emitter flow rate, the more upright the shape of wetted soil volume. The maximum vertical and horizontal water transport distance under NL treatment was higher than that under NH, EH, and EL treatments. After surface drip fertigation, nitrate nitrogen accumulated near and at the edge of the wetted soil volume. In 2020, under NL treatment, nitrate nitrogen transported to a 55 cm soil layer, which was 22.22%, 71.42%, and 57.14% deeper than that under NH, EH, and EL treatments, respectively. In 2021, nitrate nitrogen could transport to a 60 cm soil layer in both NL and NH treatments. The maximum concentration of ammonium nitrogen was nearby the emitter. Under NL treatment, ammonium nitrogen was transported to 48 and 60 cm soil layers below the emitter in 2020 and 2021, respectively, which was deeper than that observed under NH, EH, and EL treatments. The soil inorganic nitrogen residue of the NL was lower than that of the NH, EH, and EL treatments. Compared with NH, EH, and EL treatments, the two-year maize yield under NL treatment increased by 11.09%, 13.47%, and 8.66% on average, respectively. NL treatment exhibited the highest water use efficiency and nitrogen fertilizer productivity. Therefore, NL treatment (one drip tape serving for two rows with 1.3 L/h flow rate) could promote the absorption of water and nutrients, reduce inorganic nitrogen residue, and to obtain high maize yield in sandy tidal soil.

Evolution behavior of cavitation bubble in pure Sn liquid medium with narrow gap under low-amplitude ultrasound

In this study, a numerical model of cavitation bubble in the narrow-gap pure Sn liquid medium was established by two-dimensional compressible multiphase flow simulation. The effects of the pressure amplitude and the gap size on the shape, size and position of the cavitation bubble were investigated. The calculation results showed that the cavitation bubble in the narrow-gap soldering seam could exist stably after experiencing two stages of the nonlinear oscillation and the near-wall oscillation with the low-amplitude ultrasound and moved directionally on the metal substrate surface. When the pressure amplitude increased or the gap size decreased, the directional motion rate of the cavitation bubble increased and the shape of the bubble was elliptical due to the confinement effect of the substrate wall. The ultrasonic degassing mechanism of the narrow-gap soldering seam under the action of exponential decay ultrasonic vibration was analyzed by comparing the fluid pressure and velocity field variations. The flow field in the center of the soldering seam vibrated stronger than that of the peripheral regions, which could promote the outward motion of the cavitation bubble. Within the calculation time of 0.002 s, the maximum horizontal motion distance of bubble in the narrow-gap soldering seam was 1.13 mm.

Investigation of motion characteristics of catastrophic landslide using material point method and gene expression programming

This study presents two approaches (i.e., the material point method (MPM) and gene expression programming (GEP)) for prediction of landslide runout. The MPM was modified based on a strain-softening constitutive model. A collapse test and physical model test were conducted to verify the suitability of the modified MPM. The sensitivity analysis was performed to investigate the importance of the softening parameters on the motion characteristics and final accumulation state. In addition, a predictive equation for prediction of the maximum horizontal distance was proposed based on GEP, with the coefficient of determination of 0.8825. The effects of the maximum vertical distance, landslide volume and landslide posture on the maximum horizontal distance were quantitatively analyzed. Moreover, the GEP model was verified by comparison with other machine learning approaches. Finally, taking the Jiweishan landslide as an example, the simulation and prediction results obtained from the MPM and GEP approaches were compared. The results show that the two are both within a reasonable range, with the errors of 14.1% and 10.6%, respectively.

The effect of H2S content on acid gas migration and storage in shale reservoir by numerical simulation

AbstractAcid gas injection is one of the most effective strategies to deal with waste gas generated during the development of sour oil and gas reservoirs. This study numerically investigates the effect of H2S content on the acid gas migration and storage in shale reservoirs. The results indicate that the variations of acid gas density, viscosity, solubility, relative permeability, and capillary pressure caused by different H2S contents have great influence on the acid gas plume migration. When acid gas is in gas state, the maximum horizontal flow appears at the lower part of the reservoir after 5 years, and the horizontal migration distance first decreases and then remains unchanged with the increase of H2S content. Hereafter, the maximum horizontal migration distance appears at the top of the reservoir, and the horizontal migration distance first increases and then remains unchanged with the increase of H2S content. When acid gas is in liquid state, the maximum horizontal migration distance appears at the lower part of the reservoir in the early stage of injection. The horizontal migration distance decreases with the increase of H2S content. Subsequently, the maximum horizontal migration distance first decreases and then increases. The vertical migration distance increases gradually with the increase of H2S content until the acid gas reaches the top of the reservoir, and then the vertical migration distance remains unchanged. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

A numerical study for predicting the maximum horizontal distance of particles’ dispersion during transient welding processes

A numerical study for predicting the maximum horizontal distance of particles’ dispersion during transient welding processes

Numerical verification on the feasibility of compressed carbon dioxide energy storage in two aquifers

Compressed carbon dioxide energy storage in aquifers (CCESA) is a new large-scale energy storage technology derived from geological carbon dioxide sequestration, compressed air energy storage in aquifers, and compressed carbon dioxide energy storage. However, there have been no practical applications so far. In this study, we present a numerical model that simulates the whole process of gas filling period and daily cyclic period of the subsurface system of CCESA with two wellbores and two aquifers, and reveal the hydrodynamic and thermodynamic properties, energy efficiency, and the influences of wellbore and aquifer locations, injection temperature and injection rate on system performance. The results show that the fluctuation ranges of pressure and temperature in the wellbores and aquifers increase with time, especially in the high-pressure aquifer where the maximum and minimum pressures are 15.96 and 9.78 MPa after 200 days of cycles. The maximum energy efficiency of the system can reach 1.022. Within 100 days of cushion gas filling and 200 days of cycles, the maximum horizontal CO2 transportation distance in aquifers is 198.1 m, indicating a strong sealing effect of the system. The system energy efficiencies of the two target aquifers are very similar for different vertical intervals, while the variations in wellbore pressure and temperature differ significantly, which affects the energy efficiency and stability of the surface plant. Low-temperature CO2 injection is beneficial to improving the energy efficiency of the system. Increasing injection-production rate can directly improve power generation rate, and energy efficiency is also higher for higher flow rates.

Real-Time Human Motion Tracking by Tello EDU Drone

Human movement tracking is useful in a variety of areas, such as search-and-rescue activities. CCTV and IP cameras are popular as front-end sensors for tracking human motion; however, they are stationary and have limited applicability in hard-to-reach places, such as those where disasters have occurred. Using a drone to discover a person is challenging and requires an innovative approach. In this paper, we aim to present the design and implementation of a human motion tracking method using a Tello EDU drone. The design methodology is carried out in four steps: (1) control panel design; (2) human motion tracking algorithm; (3) notification systems; and (4) communication and distance extension. Intensive experimental results show that the drone implemented by the proposed algorithm performs well in tracking a human at a distance of 2-10 m moving at a speed of 2 m/s. In an experimental field of the size 95×35m2, the drone tracked human motion throughout a whole day, with the best tracking results observed in the morning. The drone was controlled from a laptop using a Wi-Fi router with a maximum horizontal tracking distance of 84.30 m and maximum vertical distance of 13.40 m. The experiment showed an accuracy rate for human movement detection between 96.67 and 100%.

Detailed Evolution Characteristics of an Inclined Structure Hailstorm Observed by Polarimetric Radar over the South China Coast

A hailstorm with an inclined structure occurred in the western part of the South China coast on 27 March 2020. This study investigates the detailed evolution characteristics of this inclined structure using the Doppler radar data assimilation system (VDRAS) and the improved fuzzy logic hydrometeor classification algorithm (HCA). Obvious differential reflectivity (often referred to as ZDR) arc characteristics, ZDR column characteristics, and the specific differential phase (often referred to as KDP) of the column are observed using dual-polarization radar prior to hailfall. Both the ZDR column and KDP column reached their strongest intensities during the hailfall phase, with their heights exceeding the height of the −20 °C layer (7.997 km above ground level), displaying a cross-correlation coefficient (CC) valley during this phase. Meanwhile, two centers of strong reflectivity were found, with one (C1) being located at 2–4 km, and the other (C2) being located at 6–8 km. The maximum horizontal distance between the two centers is 8 km, suggesting a strongly inclined structure. This inclined structure was closely related to the interaction between upper-level divergent outflows and ambient horizontal winds. The updraft on the front edge of the hailstorm continued to increase, keeping C2 at the upper level. At the same time, large raindrops at the lower part of C2 are continuously lifted, leading to ice formation. These ice particles then fell obliquely from their high altitude, merging with C1.

Numerical simulation of two droplets impacting on the wall continuously

The application of spray system has been widely used in the industry. The impact of droplets between the wall impact has become one of the important studies of spray system. The investigation is to develop a numerical code for the simulation of two water droplets impinging continuously upon the wall. In the code, the structured single-block and staggered grid system are adopted for discretization of the space domain, while the finite volume method is applied to solve iteratively the governing equations of mass and momentum. The interconnection between the velocities and pressure is dealt by SIMPLER methods. In order to capture the boundary of the deformation of droplets, a level set function method is considered due to the advantage of handling the incorporation and breakup of the boundary easily. In the paper, the numerical verification of a water droplet impinged upon the wall are very accurate with the experimental values. Subsequently, a forward droplet with different Reynolds number of 100, 200, 400 and a backward droplet with the fixed Reynolds number of 200 vertically impact the wall continuously. According to the calculation results a forward droplet with smaller the Reynolds number shows the larger the maximum spread distance after merging. In impact process of different angles, the merged droplet moves along the wall, and produces also oscillates back and forth asymmetrically. As for the maximum horizontal spread distance of the merged droplet, the impact angle of 30 degrees is the smallest, and the impact angle of 60 degrees is the largest.

Acute Effects of Different Overspeed Loads with Motorized Towing System in Young Athletes: A Pilot Study.

Simple SummaryThe towing system is a widely used method to increase running speed since it allows the athletes to run at a speed higher than the speed that they would achieve with their own methods. Currently, we dispose of motorized towing systems that provide overspeed conditions. In this study, we have analyzed the acute effects of using one of these devices with different loads in eight young athletes and thus determine the possible optimal load for their use during training. These effects have been analyzed on different variables of the sprint running technique, and it has been observed that the increase in speed is mainly due to the increase in stride length, flight time and horizontal distance of the vertical projection of the center of gravity to the first contact of the foot with the ground, as well as to reductions in contact time. However, it cannot be determined whether these results are produced by the muscular action of the athlete or by the action of the device. Following up the investigation of the effects of the motorized towing system and the individualization of loads may allow for the development of these training methods, giving them greater scientific evidence.Overspeed is a training method used to improve running speed, although its effects are not supported by consensual scientific evidence. The overspeed stimulus can be boosted by several methods, including motorized towing devices. Our objectives were to analyze the acute effects of three overspeed loads in young athletes and to select optimal loads for training periods. Eight young athletes (16.73 ± 1.69 years) performed one unassisted sprint and three assisted sprints, and kinematic and biomechanical data were compared. Significant increases (p < 0.05) in step velocity and step length were found with 2, 4, and 5.25 kg in maximum running speed, flight time and horizontal distance from the first contact to the vertical projection of the center of mass with 4 and 5.25 kg. Significant time decreases were found in 5 m flying sprint and contact time with 4 and 5.25 kg, and no significant changes were observed in step rate. The individually recommended loads would be between 3.47 ± 0.68% and 6.94 ± 1.35% body weight. Even having limitations, we can understand this work and its results as a pilot study to replicate the methodology and the use of new devices to more broadly investigate the effects of overspeed.

Capacitive Omnidirectional Position Sensor Using a Quarter Wave Resonator

An open environment, omnidirectional sensing method is presented that utilizes the mechanics of a quarter wave resonator (QWR). A highly sensitive response to external perturbations is formed as approaching objects alter the stray capacitance around the resonator, causing the system’s frequency to change. The detection range of the experimental system exceeds a 1 m radius around a 150 mm tall device. A theory is presented that predicts the voltage distribution on the QWR and further explores the maximum horizontal distance at which the voltage distribution changes due to an approaching object. The relationship between the excitation voltage versus the distance of various approaching objects is characterized as well as the vertical displacement response, sensor resolution, and the power consumed by the device. Two resonators connected to a classic differential amplifier circuit are used to demonstrate the detection of the velocity and direction of an approaching object. The advantages of the reported approach include low fabrication cost, low power consumption, and omnidirectional detection.

Bouncing dynamics of impact droplets on bioinspired surfaces with mixed wettability and directional transport control

Kingfishers stand on a branch, and raindrops tumble translationally from feathers during raining, enlightening functional surfaces design and liquid transport control. Far-ranging studies on oriented transportation are confined to vertical impacting, which is, to date, in-depth philosophy of horizontal droplets transport on motionless surface deems to be rather serviceable. This study, employed mixed-wettability surface inspired by kingfishers’ feather, occurs on directional transportation issues, such as the synergies of wettability-controlled, driving force and transportation capability. Here we conduct both experimental testing and CFD-aided numerical modelling to reproduce the asymmetric bouncing and directional transport phenomena. We found that the anisotropic surface manipulates to convert normally vertical impacting to horizontal droplets transport. Law of the thrown droplet, on the other hand, is predominated by the wettability-controlled surface, while the coexistence of contact angle difference and surface offset location cooperatively dictates the intensity and patterns of the thrown droplet. Of all these factors, the post-optimized surfaces are designed first and then the regime map of transportation pattern is elaborated. Results manifest that the elements induce the maximum horizontal transport distance by up to 6.2D0, and first desorption time is only 7.8 ms. The findings shed light on engineering design principles that can pave the way for novel applications in anti-icing, lubrication, and spray cooling.

Basketball self training shooting posture recognition and trajectory estimation using computer vision and Kalman filter

Abstract Self-shooting training is one of the fundamental criteria for success in basketball. Particularly, young players increase their performance with regular training. However, the training process becomes painful and time-consuming without a coach since the incorrect shooting posture causes missing shots, leading to reluctance. In this research, a self-shooting posture algorithm is developed to track the movement of basketball players and give them feedback about their position, angle, and basketball projectile trajectory information. The proposed algorithm uses computer vision techniques and Kalman filter to detect the best projectile trajectory using initial conditions such as acceleration due to gravity the initial velocity at the angle of launch having certain horizontal distance to the rim and the rim distance from the ground The acceleration of both gravity and air drag are altered by predefined parameters, including the drag coefficient basketball mass ball radius and silhouette area The proposed algorithm provides the shooting angle in real-time by placing the projectile angle on to the cropped image of the player posture and draws the projectile trajectory towards the basketball hoop According to the results, the players having a specified height can achieve the best shooting at the angle with air drag force. On the other hand, if there is no air resistance, the best shooting angle is deviated significantly. The other stats that are a total time of travel, maximum horizontal distance, maximum height and the time until the top are also given along with the results.

A Synthesis of Six Recent Studies on Numerosity Abilities in an Ant

AbstractWorking on the numerosity ability of the ant Myrmica sabuleti, we have already summarized for the readers’ convenience our previous papers in two successive publications. Since that time, we have produced six more papers on the subject, and we thought it was time to present a summary of them. These studies deal with the ants’ ability in expecting the following element in an arithmetic or a geometric sequence, as well as with the required similarity between visual cues and the maximum horizontal and vertical distance between such cues enabling the ants to mentally add them up. The experimental methods that were used in these studies are here only briefly reported and their most important results are concisely related, as the extended information can be found in these six papers here summarized. We present novel tables and figures for illustrating this synthesis.

Numerical investigation on transport characteristics of high-temperature fine particles generated in a transiently welding process

The motion feature of particulate pollutants in industrial buildings, has a significant impact on the indoor environment and workers' health. In this study, the numerical simulations are performed to investigate the transport characteristics of high-temperature fine particles generated during the welding processes, influenced by four different factors (i.e, release temperature (T0), release velocity (v0), operation time (t0), and particle diameter (dp)). Specifically, the movement mechanism of particles is clarified through the conservation of energy and Newton's second law. The maximum horizontal diffusion distance of particles (ΔRmax) has been proposed to assess the exposure risk of particles. Results show that the transformation between heat energy and kinetic energy drives the two-phase flow to move up. The temperature of particles drops sharply and reaches the environmental temperature at 3.0 s approximately, while their velocity increases first before decreasing slowly. The gravity acting on particles and vortex interaction of airflow result in different motion behaviors of particles in both vertical and horizontal directions. Moreover, ΔRmax is positively correlated with T0, v0, and t0, but negatively correlated with dp, and has a maximum value of 6.4 m. Generally, the motion and exposure risk of particles are dependent on the heat exchange amount and particle size. The results can contribute to health risk assessment and ventilation system design in the industrial plants.