Minimum Tension Research Articles

Construction and performance evaluation of novel compound oil displacement system for enhanced oil recovery

Conventional methods of flooding leave behind a significant amount of oil films that adhere to the rock surfaces. Developing novel compound oil displacement system to achieve efficient oil film peeling and migration is of great significance for further enhanced oil recovery. Herein, a novel compound oil displacement system was developed through optimization experiments using a binary surfactant mixture composed of SDBS and BS-18, along with a wetting regulator known as CAS. The minimum interfacial tension attained of compound oil displacement system was 0.0042 mN/m, indicating an ultra-low level. Meanwhile, the compound system could alter the rock surface wettability from oleophilic to strong hydrophilic, with the underwater oil contact angle substantially increasing from 18° to 123.1°. The compound system demonstrated remarkable stability at high water salinity (60000 ppm) and high temperature (90 °C). The surface strong hydrophilicity contributed to the excellent oil film peeling performance of compound system, leading to an 89.14% reduction in the oil film area within 12 h. The superior ability in interfacial tension reduction and wettability alteration of the compound system facilitated the “peeling off” and “migrating out” process of the residual oil film, and impressive enhanced oil recovery of 18.68% was achieved compared to that of the surfactant mixture SDBS/BS-18 (7.23%) and wetting regulator CAS (7.64%). It is believed that the outcomes of this work provide valuable insights into the design and optimization of effective oil displacement systems for residual oil development.

Sustainable solution of sewing thread attributes on seam pucker

Bending rigidity magnitude of sewing thread provides a sustainable solution on the appearance of single needle lock stitched lightweight woven fabrics which are prone to pucker. Comparison of sewing thread bending rigidity with thread count, thread diameter, thread cyclic recovery and their resultant implication in the single lock stitched assemblies were given less consideration for the prediction and reduction of seam pucker severity. The resultant implication of physical and mechanical properties of sewing thread with rising trend of static thread tension magnitude at lock stitched sewing machine has significant impact on lightweight lock stitched fabric assemblies to predict and elude seam pucker. The present research is focused to investigate impact of the thread bending rigidity on count, diameter and cyclic recovery at 4th cycle of four cores spun sewing threads. The study concluded that sewing thread bending rigidity has high coefficient of determination of sewing thread; diameter (R2 =0.81), count (R2 =0.73) and cyclic recovery (R2 =0.77). Single needle 400 lock stitched samples of two cores spun sewing threads (t2 and t4) were prepared with ten plain weave lightweight woven fabric samples prone to pucker at four different static needle thread tensions. It is also established that combined effect of sewing thread static tension and cyclic recovery at sewing machine has significant coefficient of determination (R2>0.85 at low static thread tension and R2>0.73 at very high static thread tension) to predict and elude seam pucker severity. Research finding provides a sustainable solution to select the fine count sewing thread attuned with lightweight woven fabrics prone to pucker severity. It was observed that the Fine count sewing thread has lowest bending rigidity and 4th cyclic recovery magnitudes (R2 close to 1) to reduce or predict pucker severity for prone to pucker plain weave lightweight woven fabrics at minimum static thread tension (25gf ) on single needle lock stitched sewing machine (R2>0.81).

Musculoskeletal model-based control strategy of an over-actuated glenohumeral simulator to assess joint biomechanics

Abstract Determining the acting shoulder and muscle forces in vivo is very complex. In this study, we developed a control strategy for a glenohumeral simulator for ex vivo experiments that can mimic physiological glenohumeral motion and overcome the problem of over-actuation. The system includes ten muscle portions actuated via cables to induce upper arm motion in three degrees of freedom, including scapula rotation. A real-time optimizer was implemented to handle the over-actuation of the glenohumeral joint while ensuring a minimum of muscle tension. The functionality of the real-time optimizer was also used to simulate different extents of rotator cuff tears. Joint reaction forces were consistent with in vivo measurements. These results demonstrate the feasibility and added value of implementing a real-time optimizer for using in vivo data to drive a shoulder simulator.

Reversed tension characteristics in subsea mooring connectors for an FPSO SPM in shallow water

The reversed tension on subsea mooring connectors is studied to prove its appearance. The mooring line is chosen from the real single point mooring system of Floating Production Storage and Offloading Unit (FPSO) wording in the South China Sea. The forced motion excitations are applied on the top end of the mooring line with the data monitored by the GPS device on the FPSO. The simulations are carried out with the lumped mass model and the nonlinear finite element model to verify the accuracy of the whole process. In the results of the forced excitation case, the reversed tensions are found three times. The occurrence of the revered tensions is consistent with the minus peak of the vertical displacement in time history, and the vertical displacement is recognized as the key factor for the reason of reversed tension. The reversed tension will apply a compression force on the rigid subsea mooring connect after a generous vertical displacement change. It may lead to the failure of the connector, and then the mooring line. Therefore, the minimum tension design is suggested to be added to the rules of classification society to avoid the reversed tension and slack condition of the mooring line.

Robust Adaptive Backstepping Motion Control of Underwater Cable-Driven Parallel Mechanism Using Improved Linear Model Predictive Control

This paper proposes a novel motion-tracking control methodology for an underwater cable-driven parallel mechanism (CDPM) that achieves calculation of dynamic tension constraint values, tension planning, parameter linearization, and motion tracking. The control objective is divided into three sub-objectives: motion tracking, horizontal displacement suppression, and cable-tension restriction. A linear model predictive control (LMPC) method is designed to plan cable tensions for motion-tracking and displacement suppression. The robust adaptive backstepping controller converts cable tension into winch speed based on the joint-space method and command filtering. Moreover, the X−swapping method is used to linearize and identify the time−varying nonlinear parameters. An essential prerequisite for restricting cable tension is to obtain cable-tension constraint values. A novel dynamic minimum tension control (DMTC) method, based on the equivalent control concept, is proposed for this aim. The DMTC can adaptively obtain the lower cable-tension threshold through the platform posture and motion status, anchor distribution position, and cable integrity status. Compared to traditional fixed tension constraint values, DMTC can more effectively cope with sudden changes in cable tension than fixed tension constraints. Finally, several simulations are carried out to verify the effectiveness and robustness of the proposed approach.

Interaction of crude oil with halogen-free ionic liquid-based catanionic surfactants

Chemical injection has proved to have superior performance in improving oil recovery. The injected chemicals are typically designed to participate in interfacial interactions at liquid–liquid and rock-liquid interfaces while having minimum adsorption onto the rock surface. This study endeavors to investigate the interfacial activity of several environmentally-friendly halogen-free ionic liquid-based catanionic surfactants synthesized via an ion exchange reaction between cationic imidazolium-based ionic liquids, [Cnmim][Cl] (n = 4,8,12), and anionic surfactants, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and dioctyl sodium sulfosuccinate. Results revealed that the catanionic surfactant synthesized with medium-chain ionic liquid (n = 8) and sodium dodecyl sulfate exhibited higher interfacial activity, demonstrating a minimum crude oil-brine interfacial tension of 0.17 mN/m and wettability alteration index of 0.79. The results of the adsorption study also revealed the adsorption density of 2.19 mg/g onto the dolomite surface for 2000 mg/L of catanionic surfactant in seawater, which was considerably lower than cetyltrimethylammonium bromide adsorption (11.55 mg/g) in the control experiment. Finally, the surface energy analysis of liquid-rock interactions was conducted using the concept of work of adhesion to scrutinize the wettability alteration and adsorption processes, where a direct relationship between work of adhesion and adsorption density was proposed. According to the results of this study, medium chain ionic liquid-based catanionic surfactant containing dodecyl sulfate anion, exhibiting excellent interfacial activity and low adsorption tendency onto the dolomite surface, could be considered in future chemical enhanced oil recovery applications.

Surfactant dysfunction due to e-cigarette aerosol exposure with and without additional insults

Introduction: The use of e-cigarettes (ECs) remains a popular habit for young populations, in part due to the variety of appealing flavours available. However, EC use has been associated with acute lung injury via unknown mechanisms. During a deep inhalation, one of the first compounds the EC aerosol comes into contact within the lungs is pulmonary surfactant. This complex mixture of lipids and surfactant associated proteins lines the alveolar surface and reduces surface tension to near zero values upon exhalation. Surfactant dysfunction, associated with serum protein leak and oxidative stress, contributes to lung injury. We hypothesized that exposure to EC aerosol impairs pulmonary surfactant function, and thereby increases its susceptibility to protein inhibition or oxidative stress. Methods: Bovine lipid extract surfactant (BLES) was used as a model exogenous surfactant. 2ml of BLES (2mg/ml) was placed in a syringe (30ml) attached to an EC, drawing in and expelling the aerosol 30 times. Vehicle e-liquid (VG:PG 50:50) as well as e-liquid containing flavouring additives and nicotine were utilized. Two models of injury were used, the first being addition of serum containing plasma proteins and the second oxidization by hypochlorous acid following aerosol exposure. Surface tension reduction of all samples after exposure was performed using a constrained drop surfactometer (CDS), where samples underwent 20 dynamic compression and expansion cycles. Results: Minimum surfaces tensions were significantly higher after exposure to EC aerosol across 20 compression/expansion cycles. Menthol and red wedding flavoured aerosol exposure resulted in significantly increased minimum surface tensions compared to unflavoured vehicle e-liquid, although nicotine had no additional effects beyond that of the vehicle e-liquid. The addition of plasma containing serum proteins significantly increased minimum surface tensions in aerosol exposed samples compared to those unexposed to serum and air controls. Oxidized surfactant had higher minimum surface tensions compared to control, however EC aerosol exposure had no additional effect on the inhibition of the surfactant’s function. Conclusion: EC aerosols alter surfactant function through increases in minimum surface tension. Variability in the severity of inhibition exists between flavouring additives, however the base common across all e-liquids is able to effectively inhibit surfactant. This inhibition is amplified in the presence of serum proteins. From these results we conclude that vaping impairs the pulmonary surfactant system and increases susceptibility to damage by secondary insults. Lawson Health Research Institute, NSERC This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

STRUCTURE OF THE COMPUTER MODULE OF THE KDAM PROGRAM FOR DETERMINING KINEMATIC AND DYNAMIC PARAMETERS OF THE INPUT LINK

The development of the computer module of the KDAM program for determining the kinematic and dynamic parameters of the input link of the mechanisms of light industry machines allows to determine the coordinates, projections of speeds and accelerations of the center of mass of the crank and the point of attachment of the links of the Asura groups. During the dynamic analysis of the operation of the input link, the projections of the full reaction in the hinge of the input link are determined. The obtained results are used in the program to assess the intensity of technological processes of the light and textile industry when determining the change in the relative tension of the thread in the filling zones on the technological equipment. Lever mechanisms are widely used in light and textile industry machines. The working bodies of the lever mechanisms come into contact with the threads during operation. Depending on the trajectory of the movement, the angle of coverage of the working bodies of the mechanisms of the light and textile industry machines changes. A change in the value of the angle of coverage leads to a change in the tension of the threads. When the coverage angle increases to critical values, the thread may break and the technological equipment may stop. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment. This increase is due to the interaction of the thread with the guides and tension devices. The maximum tension value will be in front of the working area. A sharp increase in tension leads to a violation of the normal course of the technological process of thread processing. The development of new schemes of the thread feeding system requires an operational assessment of the value of the tension in front of the working zone. The development of special computer programs for determining the tension in the working area makes it possible to determine the necessary technological parameters. The objective function in the tasks of optimization of technological processes is the minimum necessary tension. The variable parameter in the objective function is the sum of the angles of coverage of the working bodies by the thread. The use of a computer program allows you to determine the tension and change in relative tension in the filling zones of technological machines, which allows you to optimize the shape of the thread supply line even at the stage of designing the technological process. Computer determination of kinematic and dynamic parameters of flat mechanisms allows to determine the parameters used in determining the intensity of technological processes. The study of the influence of the design of the thread tension device on the conditions of its interaction with the thread, taking into account its unevenness in the diameter of the cross section, is important in determining the thread tension. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment.

Impact Dynamic Analysis of Suspended Marine Cables

Objective: It is often impossible to avoid collisions between marine cables, the impact dynamic response of the collisions between marine cable needs to be obtained. Methods: In this paper, we derive the lumped mass method based on the bending moment and torque; using the lumped parameter method, the suspended cable is discretized into lumped mass models, and the impact force of the suspended cable is considered in the dynamic analysis; the impact dynamics model of the suspension cable is developed by referring to the specific parameters of the suspension cable and combining them with offshore construction processes. Results: There is a relationship between the impact force and the tension of the cable. The tension and impact force are related in cable collisions. While the maximum effective tension occurs at the upper end of the vertical cable and at the collision point, the horizontal cable's tension at the collision position is minimal. The distribution of curvature mutates at the collision point, causing bending deformation. The horizontal cable experiences greater bending change at the collision position than the vertical cable. Conclusion: In summary, collision of different parts of vertical cable is not obvious, while horizontal cable is more prone to self-collision and collision with vertical cable. Collision impact on horizontal cable is greater, with minimum tension occurring at collision point. Maximum velocity for horizontal cable appears at collision position, and for vertical cable at bottom. Maximum acceleration for both cables occurs at collision zone.

Tether response of offshore Triceratops under hurricane conditions

The form-dominant approach is increasingly adopted in offshore platform design; triceratops is one of the very recent examples. These platforms are position-restrained by taut-moored tethers, which govern the dynamic response under extreme environmental loads. Due to the partial isolation of the deck from the buoyant legs in the presence of ball joints, sub-structure analysis is more critical. The present study examines the tether response of triceratops in 2400 m water-depth under hurricane conditions caused by 10-yr, 100-yr, and 1000-yr Gulf of Mexico (GoM) storms. The numerical studies show that the Peak-Wave case governs the dynamic tension variation of tethers for the chosen hurricane conditions. For the 100-yr and 1000-yr storms, they are about 15% and 45% higher than 10-yr storms, respectively. However, the maximum axial tensile stresses are about 8% of the yield, ensuring a no-rupture condition of the tethers. The service lives of the tethers for 10-yr storms are about one-third that of 100-yr and 1000-yr storms. A positive minimum tension for all load cases confirms no slackening of the tethers.

Minimum Dynamic Cable Tension Workspace Generation Techniques and Cable Tension Sensitivity Analysis Methods for Cable-Suspended Gangue-Sorting Robots

The separation of gangues from coals with robots is an effective and practicable means. Therefore, a cable-suspended gangue-sorting robot (CSGSR) with an end-grab was developed in our early work. Due to the unidirectional characteristic, the flexibility of cables, and the dynamic impact of pick-and-place gangues, one of the significant issues with the robots is robustness under internal and external disturbances. Cable tensions, being the end-grab’s constraints, have a crucial effect on the robustness of the CSGSR while disturbances are on. Two main issues related to the CSGSR, as a result, are addressed in the present paper: minimum dynamic cable tension workspace generation and a sensitivity analysis method for the dynamic cable tensions. Firstly, the four cable tensions and minimum dynamic cable tension while the end-grab was located at an arbitrary position of the task space were obtained with the dynamics of the CSGSR. In addition, with the dynamics of the CSGSR, a minimum dynamic cable tension workspace (MDCTW) generating approach is presented, where the minimum dynamic cable tensions are greater than a preset value, therefore ensuring the robustness of the end-grab under the disturbances. Secondly, a method for dynamic cable tension sensitivity (DCTS) of the robots is proposed with grey relational analysis, by which the influence degree of the end-grab’s positions on the four dynamic cable tensions and the minimum dynamic cable tensions was considered. Finally, the effectiveness of the proposed MDCTW generation algorithm and the DCTS analysis method were examined through simulation on the CSGSR, and it was indicated that the proposed MDCTW generation algorithm and the DCTS analysis method were able to provide theoretical guidance for pick-and-place trajectory planning and generation of the end-grab in practice.

DEVELOPMENT OF A COMPUTER MODULE FOR KINEMATIC AND DYNAMIC ANALYSIS OF IMPORTANT MECHANISMS OF LIGHT INDUSTRIAL MACHINES, PROGRAMS FOR ASSESSING THE TENSION OF TECHNOLOGICAL PROCESSES

The development of a computer module for kinematic and dynamic analysis of the lever mechanisms of light industry machines allows determining the parameters that are used in the program to assess the intensity of technological processes of the light and textile industry when determining the change in the relative tension of the thread in the filling zones of the technological equipment. Kinematic and dynamic analysis of flat mechanisms plays a significant role in the design of new mechanisms and modernization of existing ones. The results obtained during these studies can be used to calculate the strength of individual links, their inertial characteristics, optimization of structural parameters of mechanisms, and minimization of consumed energy. A sharp increase in tension leads to a violation of the normal course of the technological process of thread processing. The imperfection of the structural elements of the feed system, thread tensioning devices and thread guides on knitting, textile and sewing machines will not allow thread processing with a sudden increase in input tension. The development of new schemes of the thread feeding system requires an operational assessment of the value of the tension in front of the working zone. To do this, it is effective to use specially developed programs for performing a computational experiment. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment. This increase is due to the interaction of the thread with the guides and tension devices. The maximum tension value will be in front of the working area. The development of special computer programs for determining the tension in the working area allows you to determine the necessary technological parameters, make adjustments to both the structure itself and the components of the thread feeding system to obtain the minimum necessary tension in the working area. The objective function in the problem is the minimum necessary tension, which is the minimum sum of the angles covered by the thread of guide surfaces that have a cylindrical, elliptical shape, discrete segments of a straight line. The use of a computer program allows you to determine tensions and changes in relative tension in the filling zones of light and textile industry machines, which allows you to optimize the shape of the thread supply line even at the stage of designing the technological process. The development of application packages of computer programs allows to reduce the time for the design of technological processes in the light and textile industry as much as possible. This is due to the modernization of the thread filling line on the technological equipment, which allows to minimize thread tension in the working area. Minimization of tension is ensured by optimization of the shape of the thread filling line, in which the total angle of coverage of the guides will be minimal. Computer determination of kinematic and dynamic parameters of flat mechanisms allows to determine the parameters used in determining the intensity of technological processes.

Cable Tension Optimization for an Epicardial Parallel Wire Robot.

HeartPrinter is a novel under-constrained 3-cable parallel wire robot designed for minimally invasive epicardial interventions. The robot adheres to the beating heart using vacuum suction at its anchor points, with a central injector head that operates within the triangular workspace formed by the anchors, and is actuated by cables for multipoint direct gene therapy injections. Minimizing cable tensions can reduce forces on the heart at the anchor points while supporting rapid delivery of accurate injections and minimizing procedure time, risk of damage to the robot, and strain to the heart. However, cable tensions must be sufficient to hold the injector head's position as the heart moves and to prevent excessive cable slack. We pose a linear optimization problem to minimize the sum of cable tension magnitudes for HeartPrinter while ensuring the injector head is held in static equilibrium and the tensions are constrained within a feasible range. We use Karush-Kuhn-Tucker optimality conditions to derive conditional algebraic expressions for optimal cable tensions as a function of injector head position and workspace geometry, and we identify regions of injector head positions where particular combinations of cable tensions are optimally at minimum allowable tensions. The approach can rapidly solve for the minimum set of cable tensions for any robot workspace geometry and injector head position and determine whether an injection site is attainable.

Principle of object support by Rope deformation and its application to Rope climbing by snake robot

This study proposes a principle of object support by rope deformation and demonstrates the application of this principle to the operation of a snake robot that moves up and down on a rope. To realize the object support, the minimum tension required to support the object under deformation of the rope and the principle and effect of rotation of the object's posture are considered. An effective method for winding the rope is additionally examined. For the rope-climbing motion of the snake robot, we designed and fabricated a snake-shaped robot that can apply the principle of object support by rope deformation using multiple joints.

Optimal design of a single-point electromechanical cable subsurface mooring

ABSTRACT Single-point electromechanical (EM) cable subsurface mooring (EMC-SSM) is an innovative subsea structure used to measure several ocean parameters throughout a water column in real time. However, designing an EMC-SSM that can adapt to rough sea conditions is challenging owing to the relative fragility of EM cables. In this study, an optimisation design method based on parameter sensitivity analysis was proposed to improve the responses of EMC-SSM. The unreasonable design and optimisation value were determined by evaluating the slopes of the sensitivity curves of four response parameters: the minimum and maximum tensions, maximum declination angle, and maximum curvature to the net buoyancy of the main float and big sensor package (BSP); drag; added mass coefficient of the BSP; and net weight and hydrodynamic coefficient of small sensor packages. We found that the proposed optimisation design method is effective in identifying and optimising the unreasonable configurations of mooring similar to the EMC-SSM.

Minimum Cable Tensions and Tension Sensitivity for Long-Span Cable-Driven Camera Robots with Applications to Stability Analysis

Employing cables with strong flexibility and unidirectional restraints to operate a camera platform leads to stability issues for a camera robot with long-span cables considering the cable mass. Cable tensions, which are the constraints for the camera platform, have a critical influence on the stability of the robot. Consequently, this paper focuses on two special problems of minimum cable tension distributions (MCTDs) within the workspace and the cable tension sensitivity analysis (CTSA) for a camera robot by taking the cable mass into account, which can be used to investigate the stability of the robot. Firstly, three minimum cable tension distribution indices (MCTDIs) were proposed for the camera robot. An important matter is that the three proposed MCTDIs, which represent the weakest constraints for the camera platform, can be employed for investigating the stability of the robot. In addition, a specified minimum cable tension workspace (SMCTW) is introduced, where the minimum cable tension when the camera platform is located at arbitrary position meets the given requirement. Secondly, the CTSA model and cable tension sensitivity analysis index (CTSAI) for the camera robot were proposed with grey relational analysis method, in which the influence mechanism and influence degree of the positions of the camera platform relative to cable tensions was investigated in detail. Lastly, the reasonableness of the presented MCTDIs and the method for the CTSA with applications in the stability analysis of the camera robot were supported by performing some simulation studies.

STRUCTURE OF A COMPUTER PROGRAM FOR DETERMINING THE OPTIMAL PATH DIRECTED GRAPH USING DIJKSTRA’S ALGORITHM

Ensuring the minimum tension during thread processing on technological equipment allows to reduce equipment downtime due to the elimination or significant reduction of thread breaks. Minimization of tension is ensured by optimization of the shape of the thread filling line, in which the total angle of coverage of the guides will be minimal. This problem is solved by using Dijkstra’s algorithm in finding the optimal path of a directed graph. The computer program for implementing this algorithm allows you to optimize the form of filling the thread on the technological equipment. The development of application packages of computer programs allows to reduce the time for the design of technological processes in the light and textile industry as much as possible. This is due to the modernization of the thread filling line on the technological equipment, which allows to minimize thread tension in the working area. Minimization of tension is ensured by optimization of the shape of the thread filling line, in which the total angle of coverage of the guides will be minimal. This problem is solved by using Dijkstra’s algorithm in finding the optimal path of a directed graph. Construction of the optimal path of the directed graph will allow to obtain the minimum tension in the working area. Constructive structural elements in the form of guides, elements of tensioning devices, break control devices, which have a cylindrical, elliptical shape, and discrete segments of a straight line act as obstacles in the path of the thread. Straight line segments can have an inclination relative to the vertical axis. Taking into account the large number of structural elements of the thread feeding system on light and textile industry machines and their location, there is a need to develop a special computer program for determining the optimal shape of the thread feeding line using the Dijkstra algorithm when searching for the optimal path of a directed graph. The objective function in the problem is the minimum necessary tension, which is the minimum sum of the angles covered by the thread of guide surfaces that have a cylindrical, elliptical shape, discrete segments of a straight line. The use of a computer program allows you to determine tensions and changes in relative tension in the filling zones of light and textile industry machines, which allows you to optimize the shape of the thread supply line even at the stage of designing the technological process. The use of algorithms for computer programs for finding the optimal path of an undirected graph, for cylindrical, elliptical guides, discrete segments of a straight line, allows you to determine the influence of coverage angles on the target tension function. Determining the effect of coverage angles, for cylindrical, elliptical guides, discrete segments of a straight line, on the objective function during the computer determination of the optimal path for an oriented graph is an important component of the optimization of thread tension in the working area of machines of the light and textile industry, the formation of knitted and textile products.

Optimization of stretch film former of fresh food packaging machine

Current research on fresh food packaging machines focuses on vertical and horizontal sealing. Compared with the conventional pillow packaging machine, the fresh food packaging machine still presents deficiencies regarding the feeding and forming ability of stretch film. This paper presents a step former for the stretch film to integrate the existing forming mechanism. First, by analyzing the movement diagram of the stretch film on the support plate, the optimal inclination angle of the stretch film during the process of feeding on the upper part of the support plate, and the center position of the second directional wheel on the upper part of the support plate was found, it can ensure that the stretch film in the process of feeding and forming has the minimum tension and not be broken. In addition, based on the above-mentioned, the support plate and the directional wheel were simulated in software. The 2 mm 304 stainless steel support plate and different plastic combinations of directional wheels were the optimal choices.

An improved dynamic model and numerical simulation of yarn in the ring spinning system

The nonlinear dynamic behavior of ballooning yarn in the ring spinning system is investigated. An improved dynamic model of ballooning yarn with axial conveying speed is established. Based on Hamilton’s law of variation principle, the three-dimensional dynamic differential equations are derived. Then, the shooting method is employed to solve the two-point boundary value problem of ordinary differential equations. The numerical results of balloon profiles and distribution tension curves of ballooning yarns are discussed. The numerical results imply that with the increase of Ω, the yarn conveying speed increases, the minimum tension at the guide eye increases, and the helical loops of the balloon profile decrease. It is also found that as Ω increases, the spatial area of the guide eye tension [Formula: see text] that forms the dynamic balloon decreases. When the yarn conveying speed is medium or high, under different tensions at the guide eye, the yarn tensions along the height direction of the balloon change in the same trend, and the tensions of the ballooning yarn at the same height are very close. In addition, with the increase of Ω, the distribution tension of the ballooning yarn changes significantly under the same guide eye tension.

The effect of elastic reins on rein tension and performance in dressage horses

Many interactions between horses and humans are mediated through some form of physical equipment, particularly when riding. Multiple styles of reins constructed with elastic inserts are available for purchase with the promise that they will help dressage riders develop a light, steady and ‘elastic rein’ contact for the betterment of both their scores in competition and their horse's wellbeing. Although a number of studies have investigated various aspects of elastic reins, results have been inconclusive with regards to their effect on equine welfare. This study examined the effect of elasticated reins on rein tension. Using a crossover design, ten dressage horses and their usual riders performed a standardized dressage test using both leather reins and leather reins with integrated elastic inserts. Rein tension (Newtons) was recorded using strain-gauge transducers and the mean, maximum, and minimum tensions and the coefficient of variation, as a measurement of rein tension stability, were then assessed as potential indicators of impact on equine welfare and performance. Horse-rider pair performance was self-assessed by the riders and independently by a dressage judge who scored each test. Although no overall statistical differences were found in rein tension or performance measures between elasticated and non-elasticated reins, there were clear indications that this depends on the individual horse (Coefficient of Variation values ranged from 59.8 to 118.8). A commonly used descriptor regarding horse “rideability” in terms of response to rein use is whether the horse is “hard-mouthed” (i.e., generally non-responsive or responds in an unwanted manner) or “soft-mouthed” (responsive). Analysis of rein tensions and dressage test scores suggested that whilst riding “hard mouthed” horses in elasticated reins may be detrimental to welfare through impaired release of pressure, riding “soft mouthed” horses in elasticated reins may be beneficial. It is therefore apparent that the success of use of elastic in reins may depend on individual attributes of the horse, learnt or otherwise, such as whether the horse is “hard-mouthed” or “soft-mouthed.” This study confirms that the application of specific equipment, even that designed to promote better welfare outcomes for the horse, needs to be considered on an individual horse basis.