一种新的处理非封闭图像表面的三维表面提取算法研究

对皮下组织表面 ,例如表皮·真皮组织交界面进行定性和定量的检测已经越来越成为医学、生物学等诸多学科中有关人体皮肤的课题中不可或缺的重要研究手段 在利用计算机自动检测皮下组织表面的过程中 ,涉及到的一个关键问题就是如何从图像中提取边界成分 动态边界模型 (snake)作为一种边界提取算法被广泛地应用于这类问题中 在这个算法的基础上 ,提出了可以从断层图像中将对象的三维表面提取出来的算法———动态开放表面模型 并应用此算法开发了一套皮下组织表面自动提取重建系统 通过对共焦点显微镜断层图像处理的实验 ,验证了本系统的实用性和可靠性     

The Past,Present and Future of the Geo-Environment in Japan

This paper is an overview of the status in geo-environment research in the past, the present and the future in Japan as witnessed by the publications in “Soils and Foundations” over the years. The authors have paid special attention to the geotechnical researches concerning technologies of waste disposal, including radioactive waste disposal, the reuse and recycle of by-product and waste, the evaluation of the environmental impact of waste and by-product, and countermeasures and adaptations to the contamination of ground/groundwater. Some representative papers on the geo-environment published in “Soils and Foundations” have been drawn on heavily in this paper. The commentary provided by the authors is largely from a geo-environmental perspective. In addition, the authors have also paid attention to geotechnical issues in the research.     

Ultra-thin films of polysilsesquioxanes possessing 3-methacryloxypropyl groups as gate insulator for organic field-effect transistors

Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups as an organic moiety of the side chain were synthesized by sol-gel condensation copolymerization of the corresponding trialkoxysilanes. The ultra-thin PSQ film with a radical initiator and a cross-linking agent was prepared by a spin-coating method, and the film was cured integrally at low temperatures of less than 120 °C through two different kinds of polymeric reactions, which were radical polymerization of vinyl groups and sol-gel condensation polymerization of terminated silanol and alkoxy groups. The obtained PSQ film showed the almost perfect solubilization resistance to acetone, which is a good solvent of PSQ before polymerization. It became clear by atomic force microscopy observation that the surface of the PSQ film was very smooth at a nano-meter level. Furthermore, pentacene-based organic field-effect transistor (OFET) with the PSQ film as a gate insulator showed typical p-channel enhancement mode operation characteristics and therefore the ultra-thin PSQ film has the potential to be applicable for solution-processed OFET systems.     

Fabrication of a DNA-lipid-apatite composite layer for efficient and area-specific gene transfer

A surface-mediated gene transfer system using biocompatible apatite-based composite layers has great potential for tissue engineering. Among the apatite-based composite layers developed to date, we focused on a DNA-lipid-apatite composite layer (DLp-Ap layer), which has the advantage of relatively high efficiency as a non-viral system. In this study, various lipid transfection reagents, including a newly developed reagent, polyamidoamine dendron-bearing lipid (PD), were employed to prepare the DLp-Ap layer, and the preparation condition was optimized in terms of efficiency of gene transfer to epithelial-like CHO-K1 cells in the presence of serum. The optimized DLp-Ap layer derived from PD had the highest gene transfer efficiency among all the apatite-based composite layers prepared in this study. In addition, the optimized DLp-Ap layer demonstrated higher gene transfer efficiency in the presence of serum than the conventional particle-mediated systems using commercially available lipid transfection reagents. It was also shown that the optimized DLp-Ap layer mediated the area-specific gene transfer on its surface, i.e., DNA was preferentially transferred to the cells adhering to the surface of the layer. The present gene transfer system using the PD-derived DLp-Ap layer, with the advantages of high efficiency in the presence of serum and area-specificity, would be useful in tissue engineering.     

Surface Activation of Conductive Porous Alumina by Depositing Nickel Particles

Electrically conductive porous ceramics have gained a recent surge of interests in development of high-performance electrocatalysts. This paper mainly describes the electrochemical activation of conductive porous alumina (CPA) by depositing nickel nanoparticles as an electrocatalyst. The surface of the porous alumina was initially pretreated with mixed acids, followed by depositing nickel particles using an electroless method. Field-emission scanning electron microscope observation and energy diffraction X-ray spectroscopy analysis verified that Ni nanoparticles were successfully deposited onto surface of the CPA. Cyclic voltammetry and chronoamperometry analyses showed that the CPA deposited with nickel nanoparticles behaved as an efficient electrocatalyst for electrooxidation of methanol, which implied its potential application for fuel cells.     

Numerical study for hysteresis phenomena of shock wave reflection in overexpanded axisymmetric supersonic jet

When the high-pressure gas is exhausted to the vacuum chamber from the supersonic nozzle,the overexpandedsupersonic jet is formed at specific condition.In two-dimensional supersonic jet,furthermore,it is known that thehysteresis phenomena for the reflection type of shock wave in the flow field is occurred under the quasi-steadyflow and for instance,the transitional pressure ratio between the regular reflection(RR)and Mach reflection(MR) is affected by this phenomenon.Many papers have described the hysteresis phenomena for underexpandedsupersonic jet,but this phenomenon under the overexpanded axisymmetric jet has not been detailed in the pastpapers.The purpose of this study is to clear the hysteresis phenomena for the reflection type of shock wave at theoverexpanded axisymmetric jet using the TVD method and to discuss the characteristic of hysteresis phenomena.     

Generation of overpressure due to condensation in moist air jet

In the present study,a computational fluid dynamics method has been applied to investigate the effects of initialdegree of supersaturation at reservoir condition on under-expanded sonic jet structures,such as Mach disk loca-tion and diameter,barrel shock wave and jet boundary.The axisymmetfic nozzle geometry investigated was aconverging nozzle with straight part.As a result,it was found that the overpressures due to condensation generateand the characteristics of flow with generation of overpressure due to condensation in the jet were different fromthose without condensation.