Lifting Capability Research Articles

Kilogram-scale production of strong and smart cellulosic fibers featuring unidirectional fibril alignment

ABSTRACT Multifunctional fibers with high mechanical strength enable advanced applications of smart textiles, robotics, and biomedicine. Herein, we reported a one-step degumming method to fabricate strong, stiff, and humidity-responsive smart cellulosic fibers from abundant natural grass. The facile process involves partially removing lignin and hemicellulose functioning as glue in grass, which leads to the separation of vessels, parenchymal cells, and cellulosic fibers, where cellulosic fibers are manufactured at kilogram scale. The resulting fibers show dense and unidirectional fibril structure at both micro- and nano-scales, which demonstrate high tensile strength of ∼0.9 GPa and Young's modulus of 72 GPa, being 13- and 14-times higher than original grass. Inspired by stretchable plant tendrils, we developed a humidity-responsive actuator by engineering cellulosic fibers into the spring-like structures, presenting superior response rate and lifting capability. These strong and smart cellulosic fibers can be manufactured at large scale with low cost, representing promising a fiber material derived from renewable and sustainable biomass.

Experimental Investigation of Film Thickness in Wastewater Airlift Pumps by an Image Processing Method

The airlift pump is a key part of wastewater treatment and is employed as an innovative and feasible collection tool. However, as one of the key factors in the lifting capability of airlift pumps, film thickness in the gas–liquid two-phase flow operating in pumps is still an unknown topic because it is difficult to measure. This paper proposes a visualization method for measuring film thickness and investigates the film thickness when operating under gas flow with a high rate in airlift pumps using experiments. Firstly, a simulation experiment platform was built, and the images of the film structure were acquired by a high-speed camera. Then, image-processing technology and an image distortion correction were proposed to extract the gas–liquid interface for studying the thickness of the film. The experimental results demonstrated that a large film thickness ranging from 0.15 D to 0.24 D was found in airlift pumps and that its film thickness kept a constant value, even under a high gas superficial velocity, maintaining a large output liquid flow from airlift pumps. As wastewater was carried by wastewater treatment, a larger film thickness of the annular film will benefit the high lifting rate of wastewater. The works in this paper offer valuable insights for the higher performance of working airlift pumps and wastewater treatment efficiency.

Design and fabrication of bioinspired pattern driven magnetic actuators

Additive manufacturing (AM) has drawn significant attention in the fabrication of soft actuators due to its unique capability of printing geometrically complex parts. This research presents the design and development of an AM process for bioinspired, deformable, and magnetic stimuli-responsive actuator arms. The actuator arms were fabricated via the material extrusion-based AM process with magnetic particle-polymer composite filaments. Inspired by the rhombus cellular structure found in nature, different design parameters, such as the line width of the interior rhombus sides, and 3D printing parameters were studied and optimized to fabricate actuator arms that exhibit enhanced flexibility while being magnetically actuated. The trigger distance and deformation experiments revealed that the width of the rhomboids’ sides played a critical role in magnetic and bending properties. It was found that the sample with a line width of 550 µm and printing layer thickness of 0.05 mm had the maximum deflection with a measured bending angle of 34 degrees. The magnetic property measurement exhibited that the sample with a line width of 550 µm showed the maximum magnetic flux density of 3.2 mT. The trigger distance results also supported this result. A maximum trigger distance of 8.25 mm was measured for the arm with a line width of 550 µm. Additionally, tensile tests showed that the sample exhibited a 17.7 MPa tensile strength, 1.8 GPa elastic modulus, and 1.3% elongation. Based on these results, we successfully fabricated a 3D printed magnetic gripper with two rhombus cellular structured arms which showed grasping and extensive load lifting capability (up to ∼140 times its weight).

Air-Jet Levitation of Continuum Robots: Stable Head Floating by Passive Thrust Vectoring for Enhancing Mobility

Flexible, continuum-type robots can access narrow spaces in debris areas during search-and-rescue missions. However, their current problem is the lifting capability of the head, which is necessary to surmount the rubble. This study proposes a passive-thrust vectoring method to stabilize head levitation for air-jet-actuated, long, continuum robots, and thus enhance their step-climbing abilities. An air jet can generate a thrust force that is sufficient for head levitation. A critical issue in levitation involves the backward bending of the head without using any air-jet control; however, thrust control is inappropriate because of the delay caused by the long channel. Therefore, the proposed method maintains the thrust direction constant. Sufficient conditions for global stability are derived and confirmed via dynamic simulations. The proposed method is simple and can be mechanically realized with a passive head-bending mechanism, thus contributing to a lightweight design. Experiments demonstrated that the developed air-floating-type, 7-m long robot, can achieve stabilized head levitation, and that the robot can climb a step with a height of 250 mm. Robot demonstrations in rubble justify the robot’s capacity to surmount the rubble. This passive-thrust vectoring method is expected to contribute to the future enhancement of the mobility of continuum robots owing to its simplicity and practicality.

NetherDrone: a tethered and ducted propulsion multirotor drone for complex underground mining stope inspections

Underground stope mapping is crucial to evaluate the quantity of blasted rock and the site integrity. In recent years, lidar-equipped drones have been used to map stopes with higher precision and without blind spots. However, they have limitations, such as large size, challenging lidar positioning on the drone, limited flight time for detailed visual inspections, and unreliable communication underground. This paper discusses the development of a compact tethered drone called the NetherDrone, specifically designed for stope inspections. The NetherDrone uses custom ducted propulsion to increase thrust efficiency by 50%. It reduces the propellers’ diameter and overall frame while maintaining an adequate lifting capability with low power consumption. The drone features an onboard 120 m tether spool for communication and power transmission, as well as a rotating arm to deploy the cable and reduce yaw moments from the tether tension. Flights in a real stope demonstrated that the drone could effectively move at least 50 m deep into a complex stope, complete a detailed lidar scan, visually scan one face of the stope in close proximity during 20 min, travel a total distance of 270 m, and maintain communications with an operator at all times through the tether.

Hexacopter Drones for Fertilizer Sowing in the Agricultural Sector Using the Global Positioning System (GPS)

Indonesian agricultural products are one of the highest-yielding agricultural commodities on the Asian continent. Farmers are still reliant on a manual method to agricultural land care and management, one of which is the application of fertilizer to agricultural land. As a result, with the help of an unmanned aerial vehicle (UAV) or a robot flying drone, a system or fertilizer sowing equipment is utilized on plants. The results of this study led to the creation of a hexacopter drone equipped with fertilizer-based sensors and GPS. Hexacopter refers to a quadcopter having only four rotors. Drone rides are paired with tank-shaped sower actuators and fertilizer spraying as a container and fertilizer sowing method. Using GPS sensor block m8n, which serves as a satellite signal receiver and is converted to a position point in the form of longitude and latitude values, the vehicle can travel to fertilize by following the route of the coordinate point that has been identified in the agricultural land region. The Pixhawk 2.4.8 flight control system, which uses automatic or autonomous controls, can run smoothly, allowing the ride to automatically seed the track. The Lippo 2300mAh 4s battery has a maximum ride load lifting capability of 500 grams of fertilizer and a fertilizing height of three meters.

Dry mass optimization for the impulsive transfer trajectory of a near-Earth asteroid sample return mission

Asteroid sample return missions are an area of active research for deep space exploration. Trajectory optimization for near-Earth asteroid sample return missions with chemical propulsion is studied in this paper. In previous studies, minimizing the velocity increment was usually used as the optimization objective. This paper focuses on the optimization of the spacecraft dry mass, aiming to reasonably coordinate the lifting capability of the launch vehicle and the maneuvering capability of deep space probes. A multi-objective optimization model is proposed to find a Pareto-optimal solution for the maximization of the spacecraft dry mass and minimization of the transfer time, considering both impulsive maneuvers and gravity-assist maneuvers. Compared with the results of the previous optimization model to minimize the velocity increment, the simulation results show that solutions with a much higher spacecraft dry mass can be obtained, and hence, the group of feasible asteroid targets is enlarged. Multi-objective optimization of the spacecraft dry mass and transfer time can effectively redistribute the time for trajectory transfer and time available on asteroids, making mission design much more flexible.

Numerical investigations on lifting and flow performance of finger seal with grooved pad

We investigate non-contact finger seal owing to its potential to reduce the specific fuel consumption of a gas turbine engine by 2–3%. The compliance features combined with the non-contact characteristic permits the position adjustment of the finger seal to the rotor excursions without destroying the stability of the rotor-seal system. The grooved structures on the lift pad of the three-layer finger seal are proposed with a view to improve the lifting and leakage capacities. Two-way fluid-structure interaction (FSI) methods are used, and the results show that the grooved structures positively affect the sealing performance. First, an uneven clearance occurs because of the seal deformation. Next, the sealing flow field is changed owing to the grooved structure. Finally, the grooved structure is proven to improve the seal's lifting capability, and the vortices in the grooves improve the sealing performance. The vortices in the groove cavities contribute significantly to the improvement in the lifting and leakage capacities. The grooved structure changes the pressure distribution under the lift pad, and a larger force is generated on the bottom surface of the lifting pad.

Decision-Making Data: Expectations for Reproducibility of Lifting on Separate Days.

Purpose:The purpose of this study was to explore the difference in maximal lifting capability between 2 modes of lifting (traditional crate and XRTS Lever Arm) over multiple days. The differences in absolute strength values were compared with existing criteria for sincere effort during distraction-based lifting. In addition, rate of perceived exertion (RPE) is presented for the 2 modes of lifting on each day.Primary Practice Setting:Workers' compensation.Methodology and Sample:Forty-four subjects between the ages of 20 and 44 years participated in this study. Investigators established 1 repetition maximum (RM) for each subject performing the crate lift. Subjects were randomly assigned 5 weights ranging from 10% to 100% of their determined 1RM and asked to give their rating of perceived exertion after each lift. The same procedure was repeated 2–5 days later using the XRTS Lever Arm. Paired t tests and Spearman's correlation coefficient were used for data analysis. Alpha was set at less than .05.Results:There was a statistically significant difference (p < .04) between maximal lift values for the 2 lifting modes. The percent difference between the modes of lifting was 10.5% ± 6.4%. In addition, there was a positive correlation between the RPE on the 2 modes of lifting (p = .87).Implications for Case Management Practice:A functional capacity evaluation (FCE) is typically ordered after the completion of physical rehabilitation and before releasing a patient to full or modified duty. In addition to assessing the ability to function within normal job demands, an assessment of effort by the participant typically takes place during an FCE. Case managers and physicians are presented with information, allowing them to make comparisons between functional lifting abilities displayed during treatment sessions and the FCE. These comparisons may often take place with the subpoena of medical records and may be discussed during the deposition or trial process. If an FCE takes place at a different facility than the physical therapy or work conditioning treatment, 2 different modes of lifting may take place based on the equipment within each facility. The results of this study indicate that the 2 modes of lifting on separate days meet established criteria for lift comparison testing during FCEs.

농장차의 프레임 구조 해석

An agriculture machines are subjected to different loads conditions. Due to this loads variations there will be certain deformations and stress which affect the performance of the electric vehicle in adverse manner. The purpose of this paper is to analyze the total deformation and stress of the electric farm vehicle middle frame based on the finite element method. The proposed electric farm vehicle has lifting and dumping capability. Therefore, in this research four operational condition such as normal condition, dumping condition, lifting condition, and lifting-dumping condition was analyzed. In this research, the design for whole frame structure is elaborated. According to the mechanical characteristics of the frame, materials are selected and manufacturability requirements are limited. Based on ANSYS 15 software, the finite element model of electric farm vehicle is established to carry out static analysis on full-loaded conditions. The simulation results shows that the proposed design meet the strength requirements and displacement requirements. The maximum deformation 0.53611 mm and maximum stress 30.163 MPa occurred at lifting-dumping condition.

Outperforming hummingbirds' load-lifting capability with a lightweight hummingbird-like flapping-wing mechanism.

ABSTRACTThe stroke-cam flapping mechanism presented in this paper closely mimics the wing motion of a hovering Rufous hummingbird. It is the only lightweight hummingbird-sized flapping mechanism which generates a harmonic wing stroke with both a high flapping frequency and a large stroke amplitude. Experiments on a lightweight prototype of this stroke-cam mechanism on a 50 mm-long wing demonstrate that a harmonic stroke motion is generated with a peak-to-peak stroke amplitude of 175° at a flapping frequency of 40 Hz. It generated a mass lifting capability of 5.1 g, which is largely sufficient to lift the prototype's mass of 3.39 g and larger than the mass-lifting capability of a Rufous hummingbird. The motor mass of a hummingbird-like robot which drives the stroke-cam mechanism is considerably larger (about five times) than the muscle mass of a hummingbird with comparable load-lifting capability. This paper presents a flapping wing nano aerial vehicle which is designed to possess the same lift- and thrust-generating principles of the Rufous hummingbird. The application is indoor flight. We give an overview of the wing kinematics and some specifications which should be met to develop an artificial wing, and also describe the applications of these in the mechanism which has been developed in this work.

Aerodynamic Interaction between Rotor and Tilting Wing in Hovering Flight Condition

The hovering performance and the lifting capability of tiltrotor aircraft are strongly affected by the aerodynamic interaction between wing and rotors. The tiltwing concept represents an interesting technology to increase the hover performance by reducing the wing–rotor interference. The present work investigates the aerodynamic interaction between wing and rotor in hover for a scaled tiltwing aircraft half-span model. A comprehensive experimental campaign, including force measurements and particle image velocimetry surveys, was performed together with computational fluid dynamics simulations. Numerical predictions were validated using experimental data and were used to describe the flow field.

Gas–liquid flowing process in a horizontal well with premature liquid loading

Horizontal wells are widely utilized as an important technique to improve the individual well producing rate. However, the actual production performance characteristics of a horizontal well in a reservoir demonstrate that the deliverability of several horizontal gas wells has not been developed effectively because of liquid loading. Understanding of this issue is confined to the production performance characteristics of the horizontal well because of the lack of techniques for the study of the liquid removal mechanism. To address this problem, an experimental device for the liquid removal mechanism of a visual-simulation horizontal well was established. Compared with the conventional conduit flow experimental device, the experimental device established in this study not only comprehensively considers the effect of the horizontal, bend, and vertical sections of the well but can also carry out the simulation under the conditions of different trajectories and intake locations. Through an in-depth analysis of the experimental phenomenon, two parameters, namely, water lock effect and reasonable velocity of liquid removal, were introduced to represent the liquid removal mechanism of the horizontal well under different conditions. Results indicate that the liquid lifting capability of the horizontal well is restricted by the producing energy. For a low-permeability sand reservoir with high water saturation, using a horizontal well with down-dip trajectory and opening the entire formation close to the toe are propitious for the removal of liquid in the horizontal well. These experimental results support the theory on trajectory optimization, opening the middle layer position optimization, reasonable proration, and improving the liquid removal result of the horizontal well in low-permeability sand gas reservoirs with high water saturation.

Experimental investigation of the rotor-wing aerodynamic interaction in a tiltwing aircraft in hover

AbstractThe hovering performance and the lifting capability of tiltrotor aircraft are strongly affected by the aerodynamic interaction between wing and rotors. The tiltwing concept represents a promising technology to increase the hover performance by reducing the wing-rotor interference. The present work describes an experimental activity carried out on a ¼ scaled tiltwing aircraft half-model to achieve a detailed insight about the main issues characterising the aerodynamic interaction between wing and rotor in hover. The results of the experimental campaign, including both force measurements and Particle Image Velocimetry surveys, enabled to evaluate both the aircraft performance for different configurations of the tilting wing and to achieve a detailed insight about the flow physics of the rotor wake in the interaction with the wing. The test activity provided a comprehensive experimental database that was obtained over a not confidential aircraft configuration.

Modeling, analysis, and co-simulation of cable parallel manipulators for multiple cranes

With the increase of the weight and volume of building components, the collaborative working of multiple cranes is necessary when one crane cannot meet the lifting requirement sometimes. This paper is devoted to model and analyze a type of cable parallel manipulators for multiple cranes (CPMMCs). The CPMMCs have better lifting capability than a single crane and can be applied in complex lifting tasks. Kinematics and dynamics of the end-effector of the CPMMCs are studied and the reachable workspace is carried out additionally. Considering the requirements of large output torque, large motion scope etc. the hydraulic drive mode is adopted. The bond graph method is applied for the analysis of hydraulic systems. Subsequently, the AMESim models for the hydraulic systems are constructed. The performance of the CPMMCs and the accuracy of the models are verified by co-simulation under working conditions.

Armless underwater manipulation using a small deployable agent vehicle connected by a smart cable

Conventional underwater manipulation is performed by a remotely operated vehicle (ROV) equipped with a rigidly connected multi-link arm. However, accurate manipulation requires the ROV to have excellent maneuverability, which limits the design flexibility and capabilities of the vehicle. This paper instead proposes the use of a small, deployable, and highly maneuverable agent ROV as an end effector, which is connected to the main vehicle by a flexible smart cable. This cable tracks the relative position of the agent, thus eliminating the need for additional positioning sensors and allowing significant size reduction for the agent. In addition, to compensate for the limited lifting capability of the small agent, it is equipped with active buoyancy control. The proposed system can be applied to common autonomous underwater vehicles (AUVs) with minimal modification for coarse station-keeping. The whole system is operated as a conventional AUV under normal operating conditions, but the agent is deployed when manipulation or precise monitoring is necessary. Numerical simulations were performed for dynamic analysis and prototype design of the agent vehicle, and this design was implemented as a model-scale system for experiments in a test tank. This implementation confirmed the feasibility and potential capabilities of the proposed manipulation system concept.

DEMO hot cell and ex-vessel remote handling

In Europe the work on the specification and design of a demonstration power plant (DEMO) is being carried out by EFDA in the power plant physics and technology (PPP&T) programme. DEMO will take fusion from experimental research into showing the potential for commercial power generation.During the fusion reaction, components in the tokamak become highly activated. The estimated dose rate levels after shutdown (zero decay time) due to 60dpa accumulation in steel (blanket) and 30dpa (divertor) are 13.1–17.4kGy/h (blanket); 8.8–11.6kGy/h (divertor) [1], much higher than those to be encountered at ITER.Upon removal from the tokamak, components would be transported to the hot cell facility with attention to minimizing the spread of activated dust and tritium contamination. It is proposed to use a sealed cask of ∼20tonnes, running on air castors with 50% lifting capability redundancy. Due to the number and complexity of the routes taken by this transporter it would have to be an un-tethered semi-autonomous system. This poses some technical challenges, including providing sufficient battery capacity, reliable guidance and a fail safe un-tethered control system. The mass of the components being moved is assumed here to range from a few tonnes to in excess of one hundred tonnes.Before the removed in-vessel components can be processed in the hot cell, they would require a period of cooling, approximately 2.5 years, to allow dose rate and decay heating to reduce. This reduces the decay heating level to ∼1–1.5kW/m3 and a contact dose rate to ∼250Sv/h, which is more suited to dexterous man-in-the-loop remote handling (RH). During maintenance, many components would require replacement or refurbishment. The hot cell facility would have to provide all the associated RH functions and operate fully remotely. With no human intervention, an accordingly robust RH recovery system would be required.This paper describes the first steps being taken towards the design of the DEMO hot cell. It will show a comparison of the current DEMO in-vessel maintenance concepts from a hot cell perspective, describe a proposed ex-vessel transport system, and summarize the facilities that have been identified as required within the hot cell, examine current RH technology and discuss the identified critical development issues.

An aeroelastic instability provides a possible basis for the transition from gliding to flapping flight.

The morphology, kinematics and stiffness properties of lifting surfaces play a key role in the aerodynamic performance of vertebrate flight. These surfaces, as a result of their flexible nature, may move both actively, owing to muscle contraction, and passively, in reaction to fluid forces. However, the nature and implications of this fluid-structure interaction are not well understood. Here, we study passive flight (flight with no active wing actuation) and explore a physical mechanism that leads to the emergence of a natural flapping motion. We model a vertebrate wing with a compliant shoulder and the ability to camber with an idealized physical model consisting of a cantilevered flat plate with a hinged trailing flap. We find that at low wind speed the wing is stationary, but at a critical speed the wing spontaneously flaps. The lift coefficient is significantly enhanced once the wing starts to oscillate, although this increase in lift generation is accompanied by an increase in drag. Flow visualization suggests that a strong leading edge vortex attached to the wing during downstroke is the primary mechanism responsible for the enhanced lift. The flapping instability we observe suggests a possible scenario for an evolutionary transition from gliding to powered flapping flight in animals that possess compliant wings capable of passive camber. Although the flapping state is accompanied by a lower lift-to-drag ratio, the increased lifting capability it confers might have enabled increased body mass, improved foraging performance and/or flight at lower speeds, any of which might have been selectively advantageous.

Schoonebeek Heavy-Oil Redevelopment Requires Complex Chemistry Management

This article, written by Editorial Manager Adam Wilson, contains highlights of paper SPE 150635, ’Integrated Production Chemistry Management of the Schoonebeek Heavy Oil Redevelopment in the Netherlands: From Project to Startup and Steady State Production,’ by Andrew G. Shepherd, SPE, Stuart Mcgregor, and Ruud Trompert, Nederlandse Aardolie Maatschappij, and Sen Ubbels, Bob van de Gender, SPE, Theo van Ommen, SPE, and Sjoerd van der Knoop, SPE, Champion Technologies. The production chemistry management process undertaken during the design, commissioning, and startup of the Schoonebeek redevelopment faced challenging separation issues, saline water, and a multitude of other process conditions that resulted in a complex application portfolio. Chemical selection was conducted in adherence to health, safety, security, and environment (HSSE) directives and focused on unique produced fluid properties. Since startup, the success of chemical performance has come from the availability of chemical treatment programs and surveillance/sampling plans. So far, no contingency chemicals have been needed at the facilities. Introduction The Schoonebeek oil field was discovered in 1943 and operated until the late 1990s. A number of enhanced oil recovery methods were used in this field, including high- and low-pressure steam-floods, hot waterfloods, and in-situ combustion. The field is now being redeveloped, using low-pressure steam-flood with horizontal wells. Superheated steam, supplied by a combined heat and power (CHP) plant, will be injected into the reservoir through 25 wells adjacent to the production wells in 17 locations. Gross production will be evacuated from the reservoir through 44 horizontal wells in 18 locations using artificial lift pumps, with a casing vapor recovery (CVR) system included to improve the gross lifting capability. Production from each wellsite will be routed through a gross gathering system to the central treating facilities (CTF). The CTF will include the required facilities to separate the oil, water, and associated gas and treat the respective streams to export quality. Production Chemistry Management Compliance toward European chemical regulations (REACH) was one of main drivers for the short-listing of products to be applied in the Schoonebeek redevelopment. Schoonebeek crude oil has a relatively high API weight. Nevertheless, the crude oil is quite acidic, as seen in high total acid number and naphthenic acid values. Most (&amp;gt;90 wt%) of the naphthenic acids are in salt form, which means that they may affect oil/water separation. The crude oil also has very particular wax properties. A high cloud point and pour point indicate that wax precipitation and gelling in the facilities may become a problem during normal operations if not controlled. Furthermore, wax particles contribute to crude oil viscosity and also may affect separation. Fig. 1 presents an overview of the main chemical applications selected for treatment between the wellsites and the CTF and at the CTF itself, together with the main process vessels and streams.

The Relationship Between Maximal Lifting Capacity and Maximum Acceptable Lift in Strength-Based Soldiering Tasks

Psychophysical assessments, such as the maximum acceptable lift, have been used to establish worker capability and set safe load limits for manual handling tasks in occupational settings. However, in military settings, in which task demand is set and capable workers must be selected, subjective measurements are inadequate, and maximal capacity testing must be used to assess lifting capability. The aim of this study was to establish and compare the relationship between maximal lifting capacity and a self-determined tolerable lifting limit, maximum acceptable lift, across a range of military-relevant lifting tasks. Seventy male soldiers (age 23.7 ± 6.1 years) from the Australian Army performed 7 strength-based lifting tasks to determine their maximum lifting capacity and maximum acceptable lift. Comparisons were performed to identify maximum acceptable lift relative to maximum lifting capacity for each individual task. Linear regression was used to identify the relationship across all tasks when the data were pooled. Strong correlations existed between all 7 lifting tasks (rrange = 0.87-0.96, p < 0.05). No differences were found in maximum acceptable lift relative to maximum lifting capacity across all tasks (p = 0.46). When data were pooled, maximum acceptable lift was equal to 84 ± 8% of the maximum lifting capacity. This study is the first to illustrate the strong and consistent relationship between maximum lifting capacity and maximum acceptable lift for multiple single lifting tasks. The relationship developed between these indices may be used to help assess self-selected manual handling capability through occupationally relevant maximal performance tests.