Pneumatic Device Research Articles

Prediction of applied pressure on model lower limb exerted by an air pneumatic device

Air pneumatic compression is a concept used for management of venous disease, including oedema. A typical air pneumatic compression device (PCD) consists of an inflatable sleeve composed of either single or multiple pressure chambers that encircle a limb.The aim of this research was to develop a mathematical model to predict the pressure applied by an air pneumatic device to an irregular cross-sectional lower limb manikin.The radius of curvature at any cross-section of the lower limb (i.e. calf (gastrocnemius), tibial crest (anterior edge of the tibia bone)) is irregular, and differs amongst individuals and populations. The effectiveness of air pneumatic devices is difficult to predict with these irregular cross sections.A theoretical model was developed to calculate pressure applied by compression sleeves on a lower leg manikin and results compared against experimental pressure exerted on the manikin by a silicone-based PCD. This prediction was made at each of three positions.The theoretical model developed based on elliptical shaped forms predicted the pressure more accurately for the ankle to above ankle position, whereas the model based on circular shaped forms predicted the pressure more accurately for below the calf to below the knee position. Refinements to the theoretical model to predict the pressure applied by PCD are recommended.

Simulation Analysis of Pneumatic Conveying Device of Air-suction Jujube Picker Based on CFD-EDM Coupling

Simulation Analysis of Pneumatic Conveying Device of Air-suction Jujube Picker Based on CFD-EDM Coupling

Where the Methane Is-Insights from Novel Airborne LiDAR Measurements Combined with Ground Survey Data.

Airborne LiDAR measurements, parallel controlled releases, and on-site optical gas imaging (OGI) survey and pneumatic device count data from 1 year prior, were combined to derive a new measurement-based methane inventory for oil and gas facilities in British Columbia, Canada. Results reveal a surprising distinction in the higher magnitudes, different types, and smaller number of sources seen by the plane versus OGI. Combined data suggest methane emissions are 1.6-2.2 times current federal inventory estimates. More importantly, analysis of high-resolution geo-located aerial imagery, facility schematics, and equipment counts allowed attribution to major source types revealing key drivers of this difference. More than half of emissions were attributed to three main sources: tanks (24%), reciprocating compressors (15%), and unlit flares (13%). These are the sources driving upstream oil and gas methane emissions, and specifically, where emerging regulations must focus to achieve meaningful reductions. Pneumatics accounted for 20%, but this contribution is lower than recent Canadian and U.S. inventory estimates, possibly reflecting a growing shift toward more low- and zero-emitting devices. The stark difference in the aerial and OGI results indicates key gaps in current inventories and suggests that policy and regulations relying on OGI surveys alone may risk missing a significant portion of emissions.

Research on the method of skateboard edge grinding by combination of robot and pneumatic constant force grinding device

The paper presents a method of robot skateboard edging grinding based on pneumatic constant force device. To solve the problem of modeling and complex algorithm of robot end active compliance control during the grinding process, a hybrid position/force control is proposed by controlling position and force separately. That is, a kind of 2 degrees of freedom pneumatic constant force grinding device is designed to realize the constant force control in the horizontal and vertical directions, while a robot is used only for position control. Then a fuzzy PID control algorithm is proposed for smooth grinding based on the dynamic modeling of the grinding device. Experiments show that the use of fuzzy PID can effectively improve the dynamic adjustment performance of the pneumatic constant force grinding system and reduce the steady-state error. Compared with normal PID, fuzzy PID reduces the step response adjustment time of the grinding system from 400ms to within 200ms. In addition, when the constant force control is disturbed, the response adjustment time is less than 100ms and there is no oscillation, and the standard deviation of the grinding force is within 1N, which has good robustness and fulfills the requirements of edging control.

The effect of the dynamics of external load changes in the aspect of the lower limit response time of the competitors of mixed martial arts (MMA) taking into account weight categories and sport experience

Background: The main aim of this study is to analyze the influence of the external load on the reaction time of the lower limbs of mixed martial arts fighters. Material and methods: The research group consisted of 31 senior MMA fighters (with training experience of at least 10 years, divided into two weight categories: light (66-70 kg) and heavy (over 93 kg) and each of them into two categories: intermediate and advanced). The Keizer Leg Press pneumatic device (Keizer, Fresno, CA, USA) was used to evaluate the reaction time of the lower limbs of MMA fighters. The subjects performed a 20-minute warm-up and then worked on the Keizer Leg Press measuring device according to the manufacturer's protocol. Based on this data, a 10 single repetitions test was performed. The value of the external resistance and the time to the next repetition were not changed to obtain the measurement data. Results: The obtained results indicate a constant deterioration of the value of the RTLBL and RTLL variable when increasing the external load in both studied groups. In the case of advanced players in the 66-70 kg weight group, a clear (statistically significant) increase in the value of the RTLBL and RTLL variable occurred from 70% 1RM, while in the intermediate group it was from 50% 1RM, and from 80% 1RM in the weight category above 93 in both study groups. Growth dynamics was lower in the advanced group in both tested weight categories. Conclusions: Performing the progression of the external load may allow the detection of the dominance of one lower limb and determination of the dynamics of differences in the reaction time of the frontal and back limb in MMA fighters.

Pneumatic femoral broaching in direct anterior approach hip arthroplasty

AimThe aim of this study is to report the safety and efficacy of the Woodpecker pneumatic broaching system in direct anterior hip arthroplasty.Methods649 primary elective anterior bikini total hip arthroplasties...

Разработка и исследование дозирующей системы высевающего устройства пневматической сеялки

The design of a pneumatic sowing device operating on a vacuum and sowing seeds in a combined, dotted and nesting ways with the same intervals between seeds in a row and a different sowing pattern is presented. To do this, the sowing discs are equipped with magnetic plates with different numbers of holes of different diameters for sowing row-crop seeds and forage crops.

Vibration isolation concept by switchable stiffness on a semi-active pneumatic actuator

In this paper a novel technique of switchable stiffness dedicated to vibration isolation is presented. The approach utilises a semi-active pneumatic device in which the stiffness switching is obtained via controlled thermodynamic processes. The concept for the dissipation technique is introduced and a mathematical model is proposed. The system is analysed under passive and semi-active modes of operation by means of numerical simulation and in an experimental survey. The analysis consists of the model validation, an energy dissipation process study and a verification of effectiveness of the concept under varying operational conditions. As a result, it is demonstrated that the proposed technique allows for combining advantages of controllable pneumatic springs and pneumatic dampers, which constitutes an added value. It is revealed in the conducted tests that the system allows for 147% increase in energy dissipation per vibration cycle and reduce the resonant amplitude peak by 8%, both in comparison to a passive gas damper. The presented concept introduces an innovative approach to the switching stiffness techniques dedicated to vibration mitigation. The findings may significantly expand the number of their implementation possibilities.

Design Evaluation and Performance Analysis of the Inside-Filling Air-Assisted High-Speed Precision Maize Seed-Metering Device

In view of the problems of a poor seed-filling state and poor seed-cleaning effect of a precision metering device under high-speed working conditions, an inside-filling air-assisted high-speed precision maize seed-metering device was designed, fabricated, and evaluated. The overall structure and working principles of the seed-metering device are explained. Theoretical analysis and parametric design of the key parts, such as the horizontal stirring notch seed-metering plate and the wheel seed-cleaning mechanism, were carried out. The main factors that produce multiple seeding problems were studied. The forward speed (FS) and working pressure (WP) of the seed-metering device are determined as the main factors affecting the seeding performance. A quadratic orthogonal rotation combination experiment was designed. The relationship between influencing factors and performance indexes was constructed using the Design-Expert 10.0.7 software. The response surface method was used to optimize the experimental results. The results of the bench validation experiments showed that the seeding performance of the seed-metering device was excellent when the FS of the seed-metering device was 13.10 km/h and the WP of the seed-metering device was 4.75 kPa. The results of the bench comparison showed that the seeding performance of the designed seed-metering device was better than that of the conventional air-suction precision seed-metering device. This study provides theoretical and practical references for the optimized design of a pneumatic precision seed-metering device and the sustainable development of grain.

Tourniquet Complications in an Upper Extremity Orthopedic Surgery Patients

Abstract An arterial tourniquet is a pneumatic device consisting of an inflated cuff connected to a supply of compressed gas. The most common use for these tourniquets is in surgical procedures on the extremities, where the tourniquet is very useful in optimizing the operating conditions by creating a bloodless surgical field. However, the exsanguination process followed by ischemia will result in physiological problems with local and systemic consequences. The patient in the case to be discussed is a 54-year-old woman with a diagnosis of implant loosening et causa nonunion left Montegia fracture who was scheduled for implant revision surgery. From these cases, it is possible that the patient experienced tourniquet-induced hypertension, which is one of the systemic complications that can arise due to the use of the tourniquet. It is said that tourniquet-induced hypertension is often difficult to control and is resistant so it is difficult to lower it. Emerging hypertension may not present a significant problem in young, noncomorbid patients, but in these patients with comorbid of hypertensive heart disease (HHD), elevated blood pressure can be very detrimental. Preoperative ketamine, clonidine, or lidocaine has been used to prevent tourniquet pain, which can lead to increased arterial pressure that is difficult to control. The anesthetist is also obliged to monitor the duration and pressure applied by the tourniquet so that it is not excessive so that detrimental complications can be prevented.

Continuous Pneumatic Regulation of Tracheal Cuff Pressure to Decrease Ventilator-associated Pneumonia in Trauma Patients Who Were Mechanically Ventilated: The AGATE Multicenter Randomized Controlled Study

Ventilator-associated pneumonia (VAP) is the most frequent health care-associated infection in severely ill patients, and aspiration of contaminated oropharyngeal content around the cuff of the tracheal tube is the main route of contamination. Is continuous regulation of tracheal cuff pressure using a pneumatic device superior to manual assessment three times daily using a portable manometer (routine care) in preventing VAP in patients with severe trauma? In this open-label, randomized controlled superiority trial conducted in 13 French ICUs, adults (age≥ 18 years) with severe trauma (Injury Severity Score > 15) and requiring invasive mechanical ventilation for≥ 48h were enrolled. Patients were randomly assigned (1:1) via a secure Web-based random number generator in permuted blocks of variable sizes to one of two groups according to the method of tracheal cuff pressure control. The primary outcome was the proportion of patients developing VAP within 28days following the tracheal intubation, as determined by two assessors masked to group assignment, in the modified intention-to-treat population. This study is closed to new participants. A total of 434 patients were recruited between July 31, 2015, and February 15, 2018, of whom 216 were assigned to the intervention group and 218 to the control group. Seventy-three patients (33.8%) developed at least one episode of VAP within 28days following the tracheal intubation in the intervention group compared with 64 patients (29.4%) in the control group (adjusted subdistribution hazard ratio, 0.96; 95%CI, 0.76-1.20; P= .71). No serious adverse events related to the use of the pneumatic device were noted. Continuous regulation of cuff pressure of the tracheal tube using a pneumatic device was not superior to routine care in preventing VAP in patients with severe trauma. ClinicalTrials.gov; No.: NCT02534974; URL: www.clinicaltrials.gov.

The Study of Law of Distribution by Pipe Length and Transparency on Transportation of Cotton with Pneumatic Transport

The article examines pneumatic transport, one of the main functions of equipment in the sequence of technological processes in ginneries, and gives the main performance of equipment in the pneumatic transport system. Also, the efficiency of the process of transporting cotton in a pneumatic transport device, time of transportation, the share of raw cotton in the internal volume of the air pipeline during transportation and processes in the pneumatic transport system were analyzed on the basis of theoretical and practical experience.

Design Evaluation and Performance Analysis of a Double-Row Pneumatic Precision Metering Device for Brassica chinensis

In view of the low seeding efficiency and precision of seeders used for Brassica chinensis in China, a new double-row pneumatic precision metering device for Brassica chinensis was designed, fabricated, and evaluated. With the characteristics of small size and high sphericity of Brassica chinensis seeds in mind, the structure and key dimensions of the metering plate were determined, and a force analysis of the seed-filling process was carried out. The negative pressure (NP), angular velocity (AV) of the metering plate, and cone angle (CA) of the suction hole were selected as the main influencing factors of the experiment. In order to explore the influence of each single factor and the interaction between factors on the seeding performance, a single factor experiment and a central composite design (CCD) experiment were designed, respectively, and the experimental results were analyzed by analysis of variance (ANOVA). After optimizing the main influencing factors such that the target of the qualified index (QI) was greater than 94% and the miss index (MI) was less than 2.5%, it was found that when CA was 60°, NP was 1.55–1.72 kPa, and AV was 1.1–1.9 rad/s, the seeding performance was excellent. The bench verification results of seeding performance (94% ≤ Q ≤ 100%, 0 ≤ M ≤ 2.5%) and the coefficient of variation (CV) of seed mass (CV of seed mass in outer and inner circle: 5.15%; CV of total seed mass: 8.60%) under the condition of parameter optimization were analyzed; as a result, the accuracy of the parameter optimization was confirmed.

Effect of Design Changes in Pneumatic Seeding Devices on Quality Indicators of Seeding

Designs of pneumatic seeding devices operating on air-flow overpressure have been developed. Constructive changes in the dosing system of the pneumatic device have been made. Sowing disks are rigidly fixed to each other for sowing seeds of two crops simultaneously with the possibility of displacing the disks relative to each other circumferentially and of their dismantling, and the air nozzle is divided into two pairs of nozzles with the same cross-sections. One pair ensures removal of excess seeds from the cells, keeping only one, and another pair is responsible for ejection of stuck seeds from the cells without compromising their integrity and in compliance with established sowing schemes. The first design is intended for sowing seeds of two row crops in a compacted way, the second is meant for sowing seeds with different physical, mechanical, and aerodynamic properties by dotted and nested methods. Changes in the dosing system, due to the use of bushings with holes on the thread located at the bottom of the conical cells, made it possible to switch from single-grain to nested seeding without changing the seeding disks. To do this, it is enough to change the bushings of cells with two or three holes. The use of the developed designs of pneumatic seeding devices improves operational reliability and increases the yield of the sown crop up to 15%.

Fatigue resistance of composite resins and glass-ceramics on dentin and enamel

Statement of problemComposite resins and glass-ceramics are both used to restore worn teeth. Which restoration material is more durable is unclear. PurposeThe purpose of this in vitro study was to evaluate the load to failure of thin composite resins and glass-ceramic restorations on enamel and dentin under increasing repetitive loads. Material and methodsGlass-ceramic blocks (IPS e.max CAD; Ivoclar AG) were shaped into cylinders (Ø4.0×1.0 mm), crystallized, and adhesively luted to bovine dentin and enamel substrates that were embedded in polymethyl methacrylate (n=20). Identical direct composite resin restorations (Clearfil AP-X; Kuraray Noritake Dental Inc) were made and directly applied on the same substrates (n=20). All specimens were tested in a pneumatic device with a stainless steel ball that provided a stepwise increase of the load (N) starting at 250 N and increasing by 50 N after every 10 000 cycles to a maximum of 1150 N. Failures were detected by a displacement sensor and defined by chipping of restorative material or catastrophic failure. ResultsOn dentin, composite resin showed a significantly higher fatigue resistance than glass-ceramic. On enamel, no significant difference was found between the 2 materials. ConclusionsWhen bonded to dentin, thin direct composite resin restorations were more durable than glass-ceramics. When bonded to enamel, no difference was found.

INCREASING THE STABILITY OF THE SAND CUSHION BY PRESTRESSING THE REINFORCING LAYERS OF GEOSYNTHETICS

The use of prestressing of geosynthetics allows accelerate their inclusion in work, reduce deformations and gaining bearing capacity of artificial foundation. The article presents results of research of two methods of construction reinforced sand cushions. In the first case, the effect of prestressing is achieved due to a certain order of layer-by-layer soil compaction of the cushion, in the second - by laying of the swellable material between the contours of the foundations. The experiments were carried out in a laboratory tank with a pneumatic loading device. There are three stamps united by a common frame on the surface of the cushion. To assess the stress-strain state of the soil foundation, the non-contact digital tracer imaging method was used. The experimental results are presented in the graphs form of the dependence of the stamp settlement on pressure and vector fields of particle movements. Modeling has confirmed the high efficiency of prestressing. The ultimate pressure on the soil foundation with two-layer horizontal reinforcement and prestressing of the reinforcing layers in the first method was 195 kPa, in the second method - 165 kPa, whereas in the absence of prestressing this value was 110 kPa. Foundation deformations also decreased significantly.

Design and experiment of centralized pneumatic deep precision fertilization device for rice transplanter

To improve the precision of deep fertilization of paddy fields, a six-row centralized pneumatic deep precision fertilization device for a rice transplanter was designed. This device included a spiral fertilizer distribution system, centralized pneumatic fertilizer delivery system, an opener system, and a fertilization control system. The centralized airflow distribution method was used in the fertilizer delivery system to ensure that the airflow in each fertilizer pipe was evenly distributed. The rotational speeds of the power take-off (PTO) and fertilizer shaft were measured synchronously using photoelectric sensors and matched proportionately in real-time using PID closed-loop control algorithms to achieve precise fertilization rates at each working speed of the rice transplanter. There were two key considerations in the design of the control system to ensure precise fertilization. Firstly, a photoelectric sensor was used to measure the speed of the PTO; the high rotational speed of the PTO could provide a high signal frequency and improve the precision of the measurement of the transplanter’s working speed. Secondly, the fertilizer shaft speed measurement subprogram was set to sleep for a short period to reduce the vibration caused by the engine. During the tests of pneumatic fertilizer delivery system, single-factor tests on airflow distribution methods were conducted. The results showed that the coefficient of variation of the airflow speed for the centralized airflow distribution method was 1.67%, which was the least among the coefficients of the three distribution methods. In the bench tests, the rotational speeds of the fertilizer shaft were set at 10 r/min, 20 r/min, 30 r/min, and 40 r/min. The maximum coefficient of variation of the fertilization consistency in different rows was 1.49% at the rotational speed of 20 r/min. The maximum coefficient of variation of the fertilization stability was 2.86% at the rotational speed of 40 r/min, while the average fertilizer amount per lap for each distributor was 26.25 g/r. The results of the dynamic fertilization tests showed that the maximum relative error of the fertilizer distribution amount was 2.00% when the target fertilizer rates were 20, 30, and 40 kg/667 m2. The results of the field tests showed that the average relative error of the fertilization amount was 3.53%, which satisfies the design standard. This research provides a reference for optimizing pneumatic fertilizer delivery systems and improving fertilization control systems and other pneumatic precision fertilizer application devices. Keywords: agricultural machinery, deep precision fertilization, pneumatic, variable rate, transplanter, vibration elimination DOI: 10.25165/j.ijabe.20201306.5479 Citation: Zha X T, Zhang G Z, Zhang S J, Hou Q X, Wang Y, Zhou Y. Design and experiment of centralized pneumatic deep precision fertilization device for rice transplanter. Int J Agric & Biol Eng, 2020; 13(6): 109–117.

Design and Analysis of Pneumatic Rotary Locking Device of Forage Package Bale Openers

Design and Analysis of Pneumatic Rotary Locking Device of Forage Package Bale Openers

Development of methods for assessing the economic effect of using a complex impulse technologies and equipment for aggregate assembly structure of the aircraft

The object of the study is the economic effect of using a set of pulse technologies and equipment for unit assembly of aircraft structures with fixed mechanical connections. One of the main selected factors that ensure the economic effect is to improve the quality, static strength and durability of the structure, reducing the weight of the aircraft structure.The analysis of modern methods and approaches of definition of economic indicators of new technics and technologies products introduction at the enterprise which help to predict the general economic effect is carried out. The comparative efficiency of the introduced technology is used in relation to the basic one, which is used at the enterprises of the branch. The components of the economic effect from the application of a pulse technologies and equipment set are determined and the approach to the economic effect calculations from the creation and improvement of pneumatic manual pulse device (PMPD) in computer-aided design (CAD) systems is formed.In the course of the research methods for estimating the economic effect at introduction of new constructive and technological decisions of aircraft design and at application of a pulse technologies and equipment set, and also at application of PMPD CAD are offered. In comparison with similar known methods, the proposed approaches can minimize the time spent on calculations and increase the accuracy of their intended purpose. It provides an opportunity to demonstrate qualitatively the feasibility of using a pulse technologies and equipment set for unit assembly of aircraft structures with non-removable mechanical connections.Here are some ways to evaluate the effectiveness of using a decision support system (DSS). DSS contains methods, models and algorithms for decision-making, software, databases and knowledge of the subject area and recommendations for the practical use of the results of the source information analysis. The factors influencing the economic result of the use of DSS in production are shown in the form of a scheme, where for the economic life of the investment in the creation of DSS 6 years commonly-accepted for CAD were selected.

Development of Reinforced Extension Type Flexible Pneumatic Actuator with Circumferential Restraints and Its Application for Rehabilitation Device

Based on super-aging society in Japan, a welfare pneumatic device to give passive exercise for the temporally injured elderly and disabled has been actively researched and developed. In previous study, based on opinions of Physical Therapist (PT) and Occupational Therapist (OT), a home-based rehabilitation device that could give passive exercise for patients using extension type flexible pneumatic actuators (EFPA), built-in quasi-servo valves and built-in displacement sensors using a wire type linear potentiometer was proposed and tested. However, the device did not have enough force and stiffness to drive shoulders with both arms. In this study, to get enough generated force and stiffness of the device, a parallel arranged EFPA reinforced with circumferential restraint was proposed and tested. The rehabilitation device for shoulder joint using the improved actuator was also proposed and tested. The built-in attitude control system using valves, sensors and an embedded controller was also developed. As a result, it can be confirmed that the device can give passive exercise with larger moving area and enough force and torque to move patient’s shoulder joint.