骨科植入物不良事件发生原因分析及预防措施:1309例可疑医疗器械不良事件报告分析

目的归纳总结骨科植入物常见不良事件表现,分析发生的原因,并提出针对性的预防措施。方法对1309例骨科植入物可疑医疗器械不良事件进行统计分析,并结合国内外文献分析结果进行归纳总结。结果骨科植入物常见的不良事件包括表现为断裂、排异反应、伤口不愈合、松动、疼痛、弯曲变形等,这些事件的发生可能包括产品自身、操作者以及患者等方面的原因。结论骨科植入物可疑医疗器械不良事件表现种类较多,原因较为复杂,需要进一步加强骨科植入物的医疗器械不良事件监测工作。     

从1309例骨科植入物可疑不良事件分析谈医疗器械监测工作存在的问题

目的分析医疗器械不良事件监测报告收集、分析评价及控制各环节可能存在的问题,并提出改进建议。方法在对1,309例骨科植入物可疑医疗器械不良事件进行统计分析的基础上,结合国内外文献研究结果进行归纳总结。结果我国医疗器械不良事件监测工作可能存在的问题包括报告率极低,生产企业积极性不高,分析评价水平需要进一步提升,控制措施需要更加及时和适宜等。结论需要进一步加强医疗器械我国的医疗器械不良事件监测工作。     

High temperature charging efficiency and degradation behavior of high capacity Ni−MH batteries

Recently the Ni/MH secondary battery has been studied extensively to achieve higher energy density, longer cycle life and faster charging-discharging rate for electric vehicles and portable computers, and etc. In this work, the charging efficiency of the Ni−MH battery which uses Ni electrode with addition of various compounds and the degradation behavior of the 90Ah battery were studied. The battery using the Ni electrode with Ca(OH)₂ addition showed the charging efficiency and the utilization ratio significantly better than electrodes without added compounds. After 418 cycles, the residual capacities at the Ni electrode showed nearly the same values in the upper, middle and lower regions. In the case of the MH electrode, the residual capacity in the upper region appeared lower than that in other regions. As a result of ICP analysis, the amount of dissolved elements in the three regions appeared almost the same. The faster degradation in the upper region of the MH electrode was caused by the TiO₂ oxide film formed at the electrode surface because of overcharging. The thickness of the oxide film increases with cycling, so it will form a layer that is not able to allow hydrogen to penetrate into the MH electrode. This article based on a presentation made in the symposium “The 2nd KIM-JIM Joint Symposium: Hydrogen Absorbing Materials”, held at Hanyang University, Seoul, Korea, October 27–28 under the auspices of The Korean Institute of Metals and Materials and The Japan Institute of Metals.     

Numerical and experimental approach on energy dissipation in nano colloidal damper

Mechanical damping systems have been widely used to various mechanical structures and systems, and are mainly hydraulic and pneumatic devices nowadays. New damping system such as nano colloidal damper (NCD) is complementary to the hydraulic one, having a cylinder-piston-orifice structure. This study includes numerical and experimental investigation about energy dissipation of NCD by using porous silica particles. In numerical approach, the dissipated energy was obtained between compression and relaxation processes for porous silica particle in NCD according to the capillary tube theory. Furthermore, for colloidal damper, the hydraulic oil was replaced by a colloidal suspension that was consisted of a nano-porous matrix with controlled architecture and a lyophobic fluid. NCD test rig and the measuring technique of the hysteresis were described in this study Performance of the energy dissipation between numerical and experimental results was investigated and compared. As a result, the proposed NCD was proved to efficiently dissipate the mechanical energy.     

Progressive collapse performance of irregular buildings

In this study, the progressive collapse‐resisting capacities of tilted or twisted buildings were evaluated by nonlinear static and dynamic analyses. For analysis models, 30‐storey tilted buildings with braced cores and 30‐storey twisted buildings with reinforced concrete cores were designed, and their performances were compared with those of the regular buildings. According to the analysis results, the progressive collapse potential of the tilted structures varied significantly, depending on the location of the removed column. It was also observed in the tilted structures that the plastic hinges formed not only in the bays from which a column was removed, but also in the nearby bays. Similar results were observed in the analysis of the twisted structures. The progressive collapse potentials of the tilted structure were high when a column was removed from the tilted side. However, the twisted structures considered in this study had progressive collapse potentials not very large compared with those of the corresponding regular structures, mainly because more structural elements were involved in resisting progressive collapse when a structural member was eliminated. Copyright © 2009 John Wiley & Sons, Ltd.     

陶瓷厂污水结构筑物的裂缝控制

通过对陶瓷厂污水站水池裂缝成因的分析,提出了控制裂缝的主要措施,并通过实例加以印证。     

The influence of chemical passivation on the PZT/Pt electrode interface

It has been recognized that the interdiffusion of atomic species between a PZT film and the Pt bottom electrode leads to the gradual degradation of a PZT capacitor. In order to prevent this interdiffusion, experimental studies on chemical passivation to the bottom electrode surface were carried out by the sulfurization method. It was observed that a sulfur layer was built up on the Pt substrate with small grains, which resulted in a structural change at the Pt surface. Atomic force microscopy (AFM) showed that the film roughness of the Pt surface was increased by sulfur treatment. Pb(Zr_0.5Ti_0.5)O₃(PZT) thin films were prepared on a Pt/Ti/SiO₂Si bottom electrode by spin-coating techniques. The microstructure and the preferred orientation of the PZT films were shown to depend on the sulfur-treated electrode. The PZT capacitor on a clean Pt electrode was confirmed to be ferroelectric with Pr=17.7 μC/cm² and Ec=65 kV/cm from the P-E hysteresis curves. The fatigue behavior of a PZT film capacitor prepared on a sulfur-treated one was observed to be relaxed, but the absolute value of Pr was paid off.     

Effective combination of non-thermal plasma and catalyst for removal of volatile organic compounds and NOx

A plasma/catalyst hybrid reactor was designed to overcome the limits of plasma and catalyst technologies. A two-plasma/catalyst hybrid system was used to decompose VOCs (toluene) and NOx at temperature lower than 150 °C. The single-stage type (Plasma-driven catalyst process) is the system in which catalysts are installed in a non-thermal plasma reactor. And the two-stage type (Plasma-enhanced process) is the system in which a plasma and a catalyst reactor are connected in series. The catalysts prepared in this experiment were Pt/TiO₂ and Pt/Al₂O₃ of powder type and Pd/ZrO₂, Pt/ZrO₂ and Pt/Al₂O₃ which were catalysts of honeycomb type. When a plasma-driven catalyst reactor with Pt/Al₂O₃ decomposed only toluene, it removed just more 20% than the only plasma reactor but the selectivity of CO₂ was remarkably elevated as compared with only the plasma reactor. In case of decomposing VOCs (toluene) and NOx using plasma-enhanced catalyst reactor with Pt/ZrO₂ or Pt/Al₂O₃, the conversion of toluene to CO₂ was nearly 100% and about 80% of NOx was removed. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

活性炭粒子对K2CO3溶液中CO2化学吸收的强化

The enhancement of chemical absorption of CO2 by K2CO3/H2O absorbents in the presence of activated carbon (AC) particles was investigated. The results show that the gas absorption rates can be enhanced significantly in the presence of AC particles,and the maximum enhancement factor 3.7 was observed at low stirring intensities.The enhancement factor increased rapidly with the solid loading during the initial period of absorption and then became mild gradually to a maximum value. Both the liquid-solid contact area and the probability of solid particles residing at the gas-liquid interface decreased with the increase of the particle size,leading to a negative effect on the enhancement of mass transfer. The influence of the particles on gas absorption decreased with the reaction rate. The stirring speed changed the interfacial coverage and mass transfer rate on the liquid side and consequently affected the mass transfer between the gas and liquid phases; the enhancement factor decreased with the stirring intensity. A heterogeneous two-zone model was proposed for predicting the enhancement factor and the calculated results agreed well with the experimental data.     

活性炭粒子对K2CO3溶液中CO2化学吸收的强化

The enhancement of chemical absorption of CO2 by K2CO3/H2O absorbents in the presence of activated carbon （AC） particles was investigated. The results show that the gas absorption rates can be enhanced significantly in the presence of AC particles, and the maximum enhancement factor 3.7 was observed at low stirring intensities. The enhancement factor increased rapidly with the solid loading during the initial period of absorption and then be- came mild gradually to a maximum value. Both the liquid-solid contact area and the probability of solid particles residing at the gas-liquid interface decreased with the increase of the particle size, leading to a negative effect on the enhancement of mass transfer. The influence of the particles on gas absorption decreased with the reaction rate. The stirring speed changed the interfacial coverage and mass transfer rate on the liquid side and consequently affected the mass transfer between the gas and liquid phases; the enhancement factor decreased with the stirring intensity. A heterogeneous two-zone model was proposed for predicting the enhancement factor and the calculated results agreed well with the experimental data.