Effect of Locking Compression Plate on the Treatment of Limb Fracture and the Effect of Operative Success Rate and Postoperative Recovery Time

Objective:To analyze the effect of locking compression plate on the success rate of operation and the time of postoperative recovery.Methods:120 patients with limb fractures from March 2018 to March 2020 were randomly divided into control group(60 cases)and observation group(60 cases).The control group was treated with plate screw internal fixation,The observation group used locking compression plate internal fixation,Compare the effect of treatment,the success rate of operation and the time of postoperative recovery.results:compared the effective rate of the two groups,the observation group(93.33%)was significantly higher than the control group(75.00%).Compared with the two groups,the success rate of operation and the time of postoperative recovery,the observed composition power was higher than that of the control group,and the postoperative recovery time was lower than that of the control group,P<0.05.Conclusion:The use of locking compression plate for the treatment of limb fracture can significantly increase the probability of successful operation,shorten the recovery time after operation,the overall curative effect is ideal,and the clinical popularization value is high.

A theoretical and 1-D numerical investigation on a valve/valveless air-breathing pulse detonation engine

The important operating characteristics of pulsed Pressure Gain Combustion(PGC)propulsion are the pressure gain of the combustor component and the propulsive performance gain of the engine.A ramjet-type valve/valveless air-breathing pulsed detonation engine with a supersonic internal compression inlet is investigated.Based on an ideal thermal cycle,the ideal equivalent pressure ratios(pcb)of the Pulsed Detonation Combustor(PDC)are obtained theoretically which are directly related with the propulsive performance of the engine.By introducing an orifice loss model into the cycles,the critical pressure drop ratios through the orifice for the PDC achieving pressure gain and the engine achieving thrust gain are studied.More influencing factors are investigated by the use of a one-dimensional(1-D)numerical simulation model.The operating characteristics of the pulse detonation engine are investigated with changes of the valve type,the inlet/outlet area ratio of the PDC,the nozzle area ratio,and flight conditions.All these factors can affect pcbof the PDC,and pcbcan be optimized by changing the geometry of the engine.The most important influence parameter is the valve type.When using an orifice-type aerodynamic valve,simulation results show that the PDC cannot achieve the pressure gain characteristics.When a supersonic internal compression inlet is introduced to the engine,whether the Pulse Detonation Engine(PDE)can achieve thrust gain comparable with that of an ideal Brayton cycle engine not only is related to the pressure gain of the combustor,but also needs to optimize the engine structure to reduce the total pressure loss.

Passive Control of an Impulsive Wave Using a Cavity/Helical Vane System

In many engineering practices, frequently an impulsive wave is a consequence of discharge of a shockwave from the exit of a tube, leading to an annoying noise like a sonic boom. The impulsive noisehas often been a major factor to limit the performance of flow devices as well as to affect hazardousinfluences on human being. The current paper describes a new control method for the reduction ofimpulsive wave. An experiment using a simple shock tube was carried out to examine the effect of acavity/helical vane system on the impulsive wave strength. The resulting impulsive wave was influencedby the detailed configuration of the belieal vane inside the cavity which is located at the vicinity ofthe exit of a tube. The effect of the belieal vane was compared with no belieal vane tests to ensurevalidation of this kind of control strategy. The results showed that the strength of the impulsive wavecould be significantly reduced by the current passive control using the cavity/helical vane system.

Relationship between single and bulk mechanical properties for zeolite ZSM5 spray-dried particles

In this work typical mechanical properties for a catalyst support material, ZSM5 （a spray-dried granular zeolite）, have been measured in order to relate the bulk behaviour of the powder material to the single particle mechanical properties. Particle shape and size distribution of the powders, determined by laser diffraction and scanning electron microscopy （SEM）, confirmed the spherical shape of the spray-dried particles. The excellent flowability of the material was assessed by typical methods such as the Hausner ratio and the Cart index, This was confirmed by bulk measurements of the particle-particle internal friction parameter and flow function using a Schulze shear cell, which also illustrated the low compressibility of the material. Single particle compression was used to characterize single particle mechanical properties such as reduced elastic modulus and strength from Hertz contact mechanics theory. Comparison with surface properties obtained from nanoindentation suggests heterogeneity, the surface being harder than the core. In order to evaluate the relationship between single particle mechanical properties and bulk compression behaviour, uniaxial confined compression was carried out. It was determined that the Adams model was suitable for describing the bulk compression and furthermore that the Adams model parameter, apparent strength of single particles, was in good agreement with the single particle strength determined from single particle compression test.