THE FEM ANALYSIS OF SHAFT UNDER THENON-AXIAL SYMMETRICAL LOAD

The changes of stress and strain around the shaft under the non-axial symmetrical loads during the excavation are analyzed with the finite element semi-analytical method based on the separated variable method. The change laws of deformation and stress of surrounding rocks are obtaied. Moreover, an optimum method of the design and construction of the shaft lining is de veloped. which presents a new train of thought of the design and costruction of the shaft and has important theoretical value and extensive application prospects.

Characterization and Performance of Magnesium Doped Bioactive Glass Nanoparticles

The bioactive glass and related biomaterials have become increasingly popular, and have also attracted the research interest of many researchers in recent years due its special performance and tissue engineering application. In this study, to create a material with a variety of properties Mg doped hollow bioactive glass (Mg-HBG) of 80SiO2-5P2O5-10CaO-5MgO system had been produced by using a sol-gel method. The porous structure nanoparticles were specifically made by employing the cetyltrimethylammonium bromide (CTAB) as a surfactant. Magnesium was selected as a doped material with HBG, because it is the most existing cations in the human body which helps for bone metabolism as well as it has antibacterial property. Based on different investigations resulted nanoparticle with the inclusion of the lower molar fractions magnesium has good tested result. For a drug model vancomycin hydrochloride (VAN) was used in this study and it has also good antibacterial activity effect. These findings help the possibility of using Mg-HBG nanoparticles to treat infectious bone abnormalities by demonstrating their compatibility with antibiotics, drug loading and release behavior.

Trajectory optimization of aerial slung load release for piloted helicopters

This study aims to provide the pilot with optimal control time histories for stabilization of a helicopter after releasing the slung load in aerial delivery missions. A model with 21 degrees of freedom(21-DOF) has been developed and validated for a helicopter slung load system. The control history is generated with detailed procedure based on trajectory optimization. Effects of the objective function formulation on the results are discussed and rules are obtained to assist in the objective function determination. We conclude that the pilot should first decrease and then increase the collective control and adjust the longitudinal control to stabilize the helicopter after the in-hover slung load release. The obtained control history is reasonable and helpful for safety and efficiency improvement. Effects of path constraints and the Flight Control System(FCS) are studied. More stringent path constraints will lead to longer time spent and more controls. Stronger stiffness and weaker damping from the FCS will cause milder control histories but sharper on-axis state histories.

Adjustable volume and loading release of shape memory polymer microcapsules

Research on microcapsules has been conducted in recent years given trends in miniaturization and novel functionalization.In this work,we designed and prepared a series of unique shape memory polyurethane(SMPU)microcapsules with stimuli-responsive func-tions.The microcapsule has a core-shell structure in which the surface morphology can be adjusted,and it has a certain loadbearing capacity.In addition,the SMPU microcapsule has a stimuliresponsive function for shape memory and solvent response.The temperature of its shape recovery is approximately body tempera-ture,and it can swell to rupture under the stimulation of organic solvents.Thus,the SMPU microcapsule has potential applications in biomedical fields,such as drug release.