The Accuracy and Precision of an Equine In-Shoe Pressure Measurement System as a Tool for Gait Analysis

Normal horses with no clinical lameness were studied to test the hypothesis that Equine F-Scan sensors (EFS) would produce vertical force data that correlated highly with vertical force data from a force platform. Six horses were trotted across a force platform while wearing the EFS. Vertical force measurements were recorded from each system with data analyzed from hoof strikes that occurred simultaneously on both systems. Coefficients of variation (CV) were evaluated to test precision of the systems. The CV of the EFS was 10.2%, compared with 6.6% for the force platform. The accuracy of the pressure measurement system was tested by measuring agreement and a paired t test. The test for measuring agreement showed large differences between measuring devices, indicating an overall lack of agreement between measurements from the two systems, with differences ranging from 9 Newtons (N) to 1,200 N. Results from a paired t test, however, showed no significant difference between measurements from the two devices as noted by a P-value of .294, indicating a lack of significant differences because of assessment of averaged data. Because of the inability of the EFS to provide precise measurements of vertical ground reaction force as noted by high coefficients of variation and an overall lack of agreement between measurements from the two systems, this system should not be used to objectively measure vertical force in horses in its current format.     

刨花板压机压力—位移曲线的初步研究与应用

通过对刨花板压机升压闭合时压力－位移的试验研究，建立了压力－位移的近似计算公式，以指导刨花板压机液压系统的设计，现已成功地应用于刨共板多层压机和单层压机的液压系统设计。     

Usability of normal force distribution measurements to evaluate asymmetrical loading of the back of the horse and different rider positions on a standing horse

Pressure measurement devices in equine sports have primarily focused on tack (saddle pads and saddle fitting methods). However, saddle pressure devices may also be useful in evaluating the interaction and distribution of normal forces between the horse and rider, including rider position and riding technique. This study examined the validity, reliability, repeatability and possibilities of using a saddle pressure device to evaluate rider position. All measurements were performed using a standing horse. Validity was tested by calculating the correlation coefficient between measured normal force and the weight of the rider. Repeatability was tested by calculating intra-class correlation coefficients. The use of normal force measurements to evaluate horse–rider interaction was tested by adding a known weight to saddle or rider and collecting measurements with the rider sitting in four different positions.The device was found to be valid and reliable for force measurements when the measurement device was not replaced. The system could be used to determine the expected differences with added weight and in different rider positions. The normal force distribution measurement device proved to be a valid and reliable tool for studying the interaction between a rider and a static horse provided it is positioned carefully and consistently relative to both the horse and the saddle.     

稀释液溶质、渗透压、pH值和缓冲指数与低温保存鸡精液效果的关系

将葡萄糖、氯化钠、氯化钾、柠檬酸钠四种物质分别配制成三个渗透压水平(278mOsm、328mOsm、378mOsm)的12种单方精液稀释液，在低温(1～4℃)下进行鸡精液稀释保存试验，在四种物质中各选出一种好的稀释液，再将所选四种单方稀释液按不同比例制成复方精液稀释液，再次进行保存试验。所有稀释液均测定渗透压、pH值、缓冲指数、精子存活时间、精子生存指数等指标。结果表明：①柠檬酸钠、葡萄糖对鸡精液的保存具有重要作用，而氯化钾在鸡精液稀释液中并不是必需的。②复方稀释液保存效果普遍优于单方稀释液。③低温下鸡精液稀释液渗透压应为等渗或接近等渗，且最适渗透压还与构成稀释液的物质种类和相互配比有关系。④稀释液pH值应接近中性，最好与精液pH值保持一致。⑤在缓冲指数为3．894—7．257的范围内，缓冲指数与精子存活时间和生存指数呈现显著的负相关。     

注水驱油过程中地层流体渗透各向同性时的压力分布

通过把渗流的偏微分方程变成其弱解积分形式,针对油田的某一井排油水井的分布情况,用有限元法计算了注水驱油过程中储层渗透各向同性时的油、水井稳态压力分布和瞬态压力分布。结果表明,在注水加压驱油时,压力有一个逐渐变化的过程,最后达到新的稳定压力平衡状态,并揭示了地层流体的非稳态渗流是稳态渗流的特例。     

木塑熔体流变性影响挤出成型的数值模拟1）

基于计算流体动力学（ CFD）技术,对木塑复合挤出机成型段温度和压力特性分析,实现对不同流变特性参数下的单螺杆挤出机木塑熔体流动和传热进行数值模拟,获得计量段和法兰处内部流场信息,分析零剪切黏度、非牛顿指数、松弛时间和木粉含量对单螺杆挤出机内部流场的影响。数值模拟结果表明：零剪切黏度对计量段压力和法兰处压力影响较大,对剪切率影响较小;而非牛顿指数对计量段压力影响较大,对法兰处压力和剪切率影响较小;同时得到黏度随非牛顿指数的增大而增大。     

凸轮轮廓的CAD

在农产品和食品加工的自动化机械设备中,广泛应用凸轮机构。凸轮轮廓的设计有图解法和解析法,人们常用的是图解法。然而,图解法的误差较大,解析法的精度高,且可使用计算机进行辅助设计(Computer Aided Design)。用计算机辅助设计凸轮轮廓的方法简称为凸轮轮廓的CAD。在自动化机械设备中,应用最广泛的凸轮机构是直动滚子从动件盘状凸轮和摆动滚子从动件盘状凸轮。本文讨论这两种凸轮轮廓的CAD的有关问题,并提出计算机的编程方案。     

Analysis of Radial Force for Compound Gear Pump with Three Idle Gears

Based on the investigation of engaging points' displacement of gear pump with three idle gears ,the radial components of instantaneous hydraulic pressure and the engaging force of the compound pump are analyzed .The research comes to the conclusions that the instantaneous radial forces acting on center and inner gears can be balanced so long as the center gear has triple times tooth ,and the idle gear of even tooth makes less radial hydraulic pulsation than those of odd ones. [WT5HZ]     

基于Curve软件的喷嘴参数研究

针对LICHENG VP11003扇形喷嘴的喷雾参数进行分析,寻找既符合现代社会节能要求又可满足农作物生长要求具有最佳喷雾效果的喷嘴设计方案.该试验在哈尔滨博纳科技有限公司生产的喷雾性能试验台上进行,测出LICHENG VP11003扇形喷嘴在不同压力下各参数值.实际测试结果为:VP11003扇形喷嘴在压力0.2、0.3和0.4 MPa下的流量分别为0.76、0.85和0.96 L/min;雾锥角分别为98.8°、105.0°和112.5°.利用Curve软件对其参数进行模拟分析得出喷嘴在压力0.1、0.5 MPa下的流量和雾锥角分别为0.66、1.06L/min和90.4°和116.2°.试验证明根据选择的拟合方程式可以计算出其更多压力下的参数值.     

Modifying the Height of Horseshoes: Effects of Wedge Shoes,Studs, and Rocker Shoes on the Phalangeal Alignment,Pressure Distribution,and Hoof-Ground Contact During Motion

This study was designed as a comparative study with the intention to accumulate fundamental data on a wide variety of farriery methods. Twenty-five warmblood/crossbred horses, allocated into five groups (n = 5), underwent radiological and kinetic examination of the barefoot hoof, the shod hoof with a standard horseshoe, and finally a modified horseshoe. For radiographic measurements, a special podoblock with embedded reference points and changeable ground surfaces was used. Kinetic examinations were performed by placing one sensor between the shoe and the hoof and the second sensor between the shoe and the ground and then walking the horses on four different ground surfaces. When wedges were applied, the palmar angle increased by approximately 5° on all surfaces. However, this effect was only seen on firm surfaces combined with studs. Using a rocker shoe, the palmar angle increased on a firm surface (0.6 ± 0.3°) and decreased on a deformable surface (0.8 ± 0.3°). No consistent data were noted for the orientation of the proximal and middle phalanx in relation to the palmar angle. Pressure distribution showed wedges and studs to cause an increased pressure load on both the toe and the heels on a firm surface. Rocker shoes led to pressure peaks at the inner section of the toe, and high pressure was exerted on the quarters. In conclusion, all modified horseshoes showed unintended side effects and their influence on biomechanical parameters varied depending on the ground surface.