Undrained Shear Behavior of Cement Admixed Clay at High Water Content

Understanding of undrained shear behavior of cement admixed clay is of utmost importance for strength and deformation analyses in composite soft clay under short-term condition. From the critical analysis, the distinct difference in the responses of the same clay at uncemented and induced cemented states is brought out. The undrained shear behavior of uncemented clay is mainly dependent upon the clay fabric. The dismembering of the clay clusters in the fabric brings about the interlocking when the clay is in overconsolidated state. For the cement admixed clay, the clay is in meta-stable state. Hence, the strength and deformation characteristics are controlled by the clay fabric and cementation. The shear resistance is the sum of the shear resistance due to cementation qb and due to fabric qf. The term qb is practically constant with the increase in effective confining pressure at preyield state. The contribution from the clay fabric to the shear resistance qf comes into the picture at postyield state.     

Computer vision based on a hypothesization and verification scheme by parallel relaxation

Shape recovery from a monocular image is addressed. It is often said that the information conveyed by an image is insufficient to reconstruct 3D shapes of objects in the image. This implies that shape recovery from an image necessitates the use of additional plausible constraints on typical structures and features of the objects in an ordinary scene. We propose a hypothesization and verification method for 3D shape recovery based on geometrical constraints peculiar to man-made objects. The objective is to increase the robustness of computer vision systems. One difficulty with this method lies in the mutual dependency between proper assignment of constraints to the regions in a given image and recovery of a consistent 3D shape. A concurrent mechanism has been implemented which is based on energy minimization using a parallel network for relaxation. This mechanism is capable of maintaining consistency between constraint assignment and shape recovery.     

On a system of understanding assembly illustrations in an assembly manual

This paper presents an assembly illustration understanding system. The system is eventually expected to be applied to a robot which specializes in automated mechanical assembly. Assembly illustrations in an assembly manual usually have two features: 1) In addition to the figures corresponding to mechanical parts, several special line-drawings referred to as auxiliary lines in this paper are often employed for the visualization of the assembly relations among mechanical parts; 2) The assembly illustrations in an assembly manual are disposed sequentially so that the subgoal of an assembly illustration will definitely appear in its succeeding illustrations as an assemblage. Both features are important clues to the analysis and understanding of assembly illustrations. By extracting the auxiliary lines, the system recognizes assembly relations among mechanical parts, and the 3D shape of the mechanical parts as well. Moreover, based on the assembly relations, it conjectures the structural details of mechanical parts such as insertion holes which are usually invisible. After that, it characterizes the appearance of the completed assemblage described by the current illustration. The system finally verifies the result by matching with the figures in a succeeding illustration in which the completed assemblage is given as a subpart.     

Simulation of I–V characteristics of a PV module with shaded PV cells

The authors are studying a diagnostic method of a PV power generating system. We consider that the change of I–V characteristics can be utilized for the diagnosis. However, the report on the change of I–V characteristics is very little. In this paper, we investigate the relation between the output lowering due to shaded PV cells and the change of I–V characteristics, utilizing the computer simulation. It was proven from the simulation that I–V characteristics are changed by the condition of the shadow, which covered the module. The change of I–V characteristics of a PV module with shaded PV cells is discussed by the shift of the avalanche breakdown voltage of shaded PV cells.     

The melanogenesis-inhibitory, anti-inflammatory, and chemopreventive effects of limonoids in n-hexane extract of Azadirachta indica A. Juss. (neem) seeds

Seventeen limonoids (tetranortriterpenoids 1-17) were isolated from the n-hexane extract of Azadirachta indica (neem) seeds. The previously unidentified compound 16 was established by spectroscopy to be 17-defurano-17-oxosalannin. The effects of six compounds, 6 and 11-15, on melanogenesis in B16 melanoma cells was evaluated; 2 compounds, salannin (13) and 3-deacetylsalannin (15), exhibited marked inhibitory effects (70-74% reduction of melanin content at 25 μg/mL) with only minor cytotoxicity (79-85% of cell viability). Eleven compounds, 2, 3, 5, 6, and 9-15, were evaluated for inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1.7 nmol/ear) in mice; all exhibited marked anti-inflammatory activity (ID(50) values 0.22-0.57 μmol/ear). In addition, compounds 6 and 11-16 exerted moderate inhibition (IC(50) values of 410-471 mol ratio/32 pmol TPA) of TPA-induced Epstein-Barr virus early antigen (EBV-EA) activation in Raji cells. The triacylglycerol fraction of the n-hexane extract contained oleic acid (50.2%) as the most predominant fatty acid constituent.     

Electroless copper plating on acrylonitrile butadiene styrene material surfaces without chromic acid etching and a palladium catalyst

Hydrolysis modification of nitrile groups on acrylonitrile butadiene styrene (ABS) plate surfaces into carboxylic acid groups was investigated to find a new recipe for electroless copper plating of ABS plate surfaces without etching reactions using chromic acid and also without a palladium catalyst. Hydrolysis modification of nitrile groups was successfully conducted in an aqueous sodium hydroxide (NaOH) solution (70 wt %) at 80°C for more than 72 h, and nitrile groups were modified into carboxylic acid groups. The hydrolysis modification was accelerated by the addition of dioxane as a supplement to the aqueous NaOH solution. The modification, when an aqueous mixture solution of NaOH (35 wt %) and dioxane (10 wt %) was used as a reagent, was accomplished at 65°C in 30 min. The hydrolyzed ABS plate surfaces were successfully metalized by electroless copper plating. A silver catalyst, instead of a palladium catalyst, was usable in the electroless copper‐plating process. Adhesion between the deposited copper metal and ABS plate surface was perfect for the Scotch tape test. Consequently, we propose a new recipe for an electroless copper‐plating process without an etching process using chromic acid and without a palladium catalyst. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Interaction of nanogel with cyclodextrin or protein: Study by dynamic light scattering and small-angle neutron scattering

The structure of hydrogel nanoparticles (CHP nanogels), formed by self-aggregation of cholesterol-bearing pullulan (CHP) was studied by dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The interactions between the CHP nanogel and methyl-β-cyclodextrin (CD) or protein (hen egg white) were also investigated. It was revealed by SANS that the nanogels were spherical in shape with a radius of 6.7 nm. The following two functions were disclosed. (1) CHP nanogels were dissociated by the addition of CD and formed inclusion complexes with cholesteryl groups, leading to suppression of hydrophobic interaction between the cholesteryl groups. (2) The nanogel behaved as a molecular chaperone (heat shock protein-like activity) when CHP nanogel was mixed with hen egg white and heated up to 75 °C. The egg white aqueous solutions with CHP nanogel remained transparent while the egg white without CHP nanogel became opaque.     

Synthesis and optical properties of 2,6-anthracene-bridged periodic mesostructured organosilicas

2,6-Bis(triethoxysilyl)anthracene was first synthesized by rhodium-catalyzed disilylation of 2,6-bis(trifluoromethanesulfonyloxy)anthracene with triethoxysilane. Using the new precursor, anthracene-bridged periodic mesostructured organosilicas were obtained without cleavage of the Si–C bondings. The anthracene-silica hybrids showed absorption at near ultraviolet region and blue–green fluorescence with a quantum yield of 0.13–0.15. The absorption and fluorescence behaviors of the 2,6-anthracene-silica hybrid film were compared with those of the previously reported 9,10-anthracene-silica hybrid film. Their absorbances suggest that the 2,6-anthracene groups were packed more densely than the 9,10-anthracene groups in the mesoporous frameworks due to smaller steric hindrance. In spite of the densely packed structure, the 2,6-anthracene-silica hybrid film showed fluorescence emission at shorter wavelengths and a higher quantum yield than those of the 9,10-anthracene-silica hybrid film, suggesting relatively weak interaction between the anthracene groups in the framework because of restriction of intramolecular rotation motion for substitution at 2,6-positions of anthracene. Dilution of the anthracene groups in the framework with trimethoxysilane promoted monomeric fluorescence and an increase of its quantum yield up to 0.18.