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The existing critical buckling load calculation methods of horizontal hydraulic cylinder failed to fully reflect the initial boundary conditions and some critical influence factors, resulting in an unjustified critical buckling load. A new method to analyze the buckling behavior of the horizontal hydraulic cylinder articulated at both supports is developed on basis of large deflection theory and Timoshenko beam theory. Friction at supports, self-weight and initial misalignment by clearances are taken into account. Friction moments of supports are built according to Hertz contact theory. Bending stiffness of cylinder-rod junction is figured out in terms of elastic deformation theory. Runge–Kutta and Newton–Raphson method are used in numerical calculation for the critical buckling load. Practical calculation and stability test are carried out to verify the necessity of considering large deflection and shear effect in the proposed method. Experimental work shows the critical buckling load by the proposed method can well match to that by stability test with 0.55% deviation. Moreover, the numerical calculation results demonstrate that the friction moment of the support at piston rod end is crucial for the buckling behavior. The critical buckling load rises increasingly as the friction coefficient ${\mu }_2$ rises. As the friction coefficients ${\mu }_2$ increases from 0 to 0.020, the rise rate of critical buckling load increases from 1.782% to 8.055% per 0.001. And the clearance at cylinder-rod junction is a minor factor on the critical buckling load. As the clearances increase by 10 times, the critical buckling load decreases by 3.542%.

Previously, the contact states between the bearing and journal of a spatial revolute joint (SRJ) with both axial and radial clearances were solved in the global coordinate system (GCS), which is complex and requires iterations. In this paper, a local-coordinate representation for the SRJs with clearance is combined with a vector-form particle-element method, i.e. finite particle method (FPM), to provide a more practical means for evaluation of the dynamic effects due to clearance. Firstly, the fundamentals of the FPM for analysis of spatial mechanisms are briefed. Then, a local-coordinate representation based on the revolution axis of the bearing is proposed. Specifically, the geometry of the journal and bearing is explicitly expressed using the coordinate transformation. The axial and radial contact states are evaluated by substituting the parametric equations and transforming them to quadratic and quartic equations, respectively, which can be analytically solved without iterations. The contact forces are evaluated in the local-coordinate representation and then transformed into the GCS representation. Two numerical examples, i.e. a spatial slider-crank mechanism and a spatial double pendulum, are provided to demonstrate the feasibility of the proposed method, by which the effects of joint-joint interaction and joint-flexible component interaction are fully discussed.

The hemodialyzer, known as “artificial kidney”, serves as an excellent tool in filtering the impurities from blood. The structure of the hemodialyzer plays a major role in separation of solutes through diffusion. The hemodialyzer module consists of thousands of hollow fibers, which actually filter the toxins such as urea and creatinine from the blood. Many of the commercially available hemodialyzer modules consist of fibers available in different configurations, viz. straight and crimped (undulated). It has been reported that fiber crimping enhances solute clearance. In crimped fibers, the waviness is dictated by two parameters, namely the crimp count and crimp amplitude. These two parameters should be optimized when inducing fiber crimps. However, excessive crimping also leads to fiber damage. In this paper, the hemodialyzer membrane is modeled which describes the structure of Fresenius Polysulfone-Hemoflow (F6HPS) in two configurations, viz. straight and crimped and finite element analysis is carried out using finite element software COMSOL multiphysics5.2a. The solute clearance is studied in straight fibers as well as crimped fibers for the same length while varying the crimp count and crimp amplitude. It has been observed that in crimped fibers, increasing the crimp count and crimp amplitude increases the clearance significantly when compared to straight fibers. While increasing the crimp count as $C_n=8$, the clearance is nearly twice that of straight fiber. This clearly shows that when developing hemodialyzers with undulations, the crimp count and crimp amplitude has to be optimized in order to get a better filtering efficiency.

Neutrophils are key effector cells involved in host defence against invading organisms such as bacteria and fungi. Their over-recruitment, uncontrolled activation and defective removal contribute to the initiation and propagation of many chronic inflammatory conditions. Neutrophil apoptosis is a physiological process that terminates the cells' functional responsiveness and induces phenotypic changes that render them recognizable by phagocytes (e.g. macrophages). Evidence indicates that neutrophil apoptosis and the subsequent removal of these cells by macrophages occur via mechanisms that do not elicit an inflammatory response and that these processes are fundamental for the successful resolution of inflammation. The molecular mechanisms regulating apoptosis in neutrophils are being elucidated and consequently it is now believed that selective induction of neutrophil is a potential target for therapeutic intervention.

The numerical simulation of diffusion bonding of Ti-6Al-4V loop and ZQSn10-10 pole assembled structure was carried out by ANSYS. The results indicate that the maximal stress emerges in joint region of Ti-6Al-4V loop and ZQSn10-10 pole. The steady-state Mises stress and clearance is an approximate linear relationship. The greater clearance, the stress decreases more gently. The transient-state Mises stress increases with the increasing bonding time. When the bonding time is 2500s, a platform appears in the stress curve, so the Mises stress remain relatively steady.