Microstructural investigation of long-term degradation mechanisms in GFRP dowel bars for jointed concrete pavement

Steel dowel bar is used to transfer loads in concrete pavement slab. However, once the steel dowel bar corrodes, it may cause faults, such as joint freezing in concrete pavement, level differences resulting from spalling or decreased efficiency of load transfer, etc., which are the same problems experienced by typical reinforcing steel. This study evaluated the applicability of glass fiber-reinforced polymer (GFRP) dowel bar as a substitute for steel dowel bar. A microstructural analysis was conducted to examine the decrease in durability of GFRP dowel bar exposed to deterioration environments. To analyze the deterioration mechanism of GFRP dowel bar, scanning electron microscopy was employed and the porosity was measured by the gas absorption method. It was concluded that the longer the GFRP dowel bar was exposed to deterioration environments, the more the interlaminar shear stress decreased. This result was validated by the microstructural analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Development of a simple model for batch and boundary information updation for a similar ship’s block model

In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD) to the hull production design process to define manufacturing and assembly information.The production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship’s block,and supply information.Therefore,many shipyards are investigating the complete automation of the production design process to reduce the M/H for designers.However,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design process.In this study,a process was developed to aid production design engineers in designing a new ship’s hull block model from that of a similar ship previously built,based on AVEVA Marine.An automation system that uses the similar ship’s hull block model is proposed to reduce M/H and human errors by the production design engineer.First,scheme files holding important information were constructed in a database to automatically update hull block model modifications.Second,for batch updates,the database’s table,including building specifications and the referential integrity of a relational database were compared.In particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific panel.Third,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels.     

Diffusion tensor interpolation profile control using non-uniform motion on a Riemannian geodesic

Tensor interpolation is a key step in the processing algorithms of diffusion tensor imaging (DTI), such as registration and tractography. The diffusion tensor (DT) in biological tissues is assumed to be positive definite. However, the tensor interpolations in most clinical applications have used a Euclidian scheme that does not take this assumption into account. Several Rie-mannian schemes were developed to overcome this limitation. Although each of the Riemannian schemes uses different metrics, they all result in a ‘fixed’ interpolation profile that cannot adapt to a variety of diffusion patterns in biological tissues. In this paper, we propose a DT interpolation scheme to control the interpolation profile, and explore its feasibility in clinical applications. The profile controllability comes from the non-uniform motion of interpolation on the Riemannian geodesic. The interpolation experiment with medical DTI data shows that the profile control improves the interpolation quality by assessing the reconstruction errors with the determinant error, Euclidean norm, and Riemannian norm.     

A framework for modern manufacturing economics

Modern manufacturing economics is an interdisciplinary research subject which deals with the cycles of performance measurement, cost estimation, and decision analysis that are enmeshed with quantification of ill-structured benefits of advanced manufacturing technologies (AMT). This paper proposes a framework of modern manufacturing economics by examining recent research trends of AMT economics. It underscores integrated, quantitative, global, and strategic studies of AMT economics.     

核磁共振测井仪刻度系统机械结构设计

核磁共振测井仪刻度系统是把探头放在一个特殊的水套里进行测井,从而获得测量的输出数据与被测地层的固有物理参数的标准量值之间的转换关系。对核磁共振测井仪刻度系统的总体布局、刻度筒、刻度筒支架、岩心调节机构、循环系统等主要机械结构进行了优化设计,不仅可以完成仪器的刻度任务,而且可作为核磁共振测井技术的研究试验平台。     

Threshold voltage shift of submicron p-channel MOSFET due to Si surface damage from plasma etching process

We compared performances for transistors produced using both wet and dry etching for non-silicide processes in the CMOS technology. It was found that the dry process for non-silicide area induces the threshold voltage shifting of the pMOS transistor as well as increases the contact resistance on active region. Also, GIDL (gate-induced-drain-leakage) current has a poor junction leakage current compared with the wet etching process. Moreover, the dry etching process changes the doping profile of the P⁺ junction and the p-channel transistor region. The experiments showed the dry etching process generates the Si-SiO₂ interface trap site due to plasma-induced damage.     

液压挤压对复合铸造Al3003/Al4004包覆材料显微组织的影响(英文)

研究液压对混合复合铸造Al 3003/Al 4004包覆材料微观组织变化的影响。复合铸造Al 3003/Al 4004包覆材料试样为圆形,由Al 3003(外部)和Al 4004(内部)材料组成。采用液压设备,在温度423 K、挤压比5的条件下制造试样。在挤压之前,Al 4004材料的直径为80 mm,Al 3003材料的厚度为35 mm,在挤压后,2种材料的直径和厚度分别为30 mm和5 mm。研究了2个试样的微观组织和硬度。在挤压之前,复合铸造Al 3003/Al 4004包覆材料横截面的硬度以抛物线的形式向中心增大。然而,在挤压后,Al 4004材料的硬度几乎没有变化。在挤压之前,Al 3003和Al 4004材料的界面存在大量直径超过1 mm的大空洞,这些大空洞随着液压过程的进行而消失。     

EVIDENCE OF CROSS-CONTAMINATION OF AEROMONAS HYDROPHILA BY FINGERPRINTING: SIGNIFICANCE FOR FOOD SAFETY

The prevalence of Aeromonas hydrophila in a local wet market was studied and fingerprinting was used to prove the cross‐contamination. This study describes the use of antibiotic‐resistant plasmid profiles and random amplified polymorphic DNA (RAPD) assay to characterize strains of A. hydrophila. Almost all strains had multiple antibiotic resistances and carried small plasmid(s) of 1.4–6.0 MDa that enabled the A. hydrophila to be grouped into eight plasmid patterns. The RAPD‐polymerase chain reaction profiles observed after electrophoretic separation of the amplified products using primer GEN15007, which enable the A. hydrophila strains to be grouped into three clusters, demonstrate that the A. hydrophila strains were genetically heterogeneous. These results suggest that RAPD assay could be a valuable tool for epidemiological studies. In addition, antibiotic‐resistant and plasmid profiling can also be used as adjunct tools in this study.