Homogeneous and Disordered Assembly of Densely Packed Nanocrystals

A homogeneous and disordered assembly of densely packed nanocrystals is generated without the assistance of organic molecules, from an aqueous solution at room temperature. The densely packed nanocrystals of tin dioxide (SnO₂) and titanium dioxide (TiO₂), 2–3 nm in size, form glassy macroscopic transparent objects of 2–10 mm. The monodisperse nanocrystals, which have a surface hydrated layer and are synthesized in aqueous solution, are densely packed in an homogeneous and disordered assembly through the evaporation of water as the dispersion medium. The formation of transparent bulk objects on the macroscopic scale originates from the homogeneous and disordered nature of the densely packed nanocrystals. The resultant homogeneous architectures are distinguishable from the typical inhomogeneous and disordered aggregates of nanoparticles observed after evaporation of the dispersion medium. Among superstructures based on nanocrystals, such as superlattices and mesocrystals, the resultant homogeneous and disordered assembly can be regarded as a new class of solid‐state material.     

Ethylamine content of fresh tea shoots and made tea determined by high performance liquid chromatography

The ethylamine contents of tea shoots and made teas were derived with o-phthalaldehyde and 2-mercaptoethanol, and quantified by high performance liquid chromatography. The coefficient of variation of this method was 1.97% from eight analyses. The levels of ethylamine in tea shoots declined markedly during growth and senescence after plucking; they also declined in the extracts of fresh tea during the incubation at 37°C, but this decrease was completely inhibited by amine oxidase inhibitors. The content of ethylamine in high grade green teas was higher than in low grade teas, but was almost identical in high and low grade black tea. The mean contents of ethylamine in 22 green teas and 17 black teas were 6.76±3.07 μmol g^?1 and 6.40±1.82 μmol g^?1, respectively.     

Gaussian process motion graph models for smooth transitions among multiple actions

We propose a unified model for human motion prior with multiple actions. Our model is generated from sample pose sequences of the multiple actions, each of which is recorded from real human motion. The sample sequences are connected to each other by synthesizing a variety of possible transitions among the different actions. For kinematically-realistic transitions, our model integrates nonlinear probabilistic latent modeling of the samples and interpolation-based synthesis of the transition paths. While naive interpolation makes unexpected poses, our model rejects them (1) by searching for smooth and short transition paths by employing the good properties of the observation and latent spaces and (2) by avoiding using samples that unexpectedly synthesize the nonsmooth interpolation. The effectiveness of the model is demonstrated with real data and its application to human pose tracking.     

An experimental study for transmitting MPEG-2 streams over ATM networks

This paper presents a comparative study of different techniques aiming at transmitting MPEG-2 streams over ATM networks, with emphasis on the presentation of practical results achieved on an experimental platform available at LSI, a laboratory of the University of São Paulo, Brazil. This study has the purpose to determine some tuning parameters for optimizing the implementation of distributed multimedia applications on different network technologies. The focus of this experimental study has been on non-native ATM techniques like “Classical IP over ATM” and “LAN Emulation”, as well as native ATM techniques based on direct access service primitives to AAL5. The influence of different parameters, like packet length, buffer size, CPU speed, on the resulting throughput has been studied. Furthermore, a testing tool is being developed for assessing the transmission of MPEG-2 streams based on the practical experience achieved so far. These results will permit the evaluation of different network technologies and also help in the development of distributed multimedia applications like video-on-demand, videoconferencing and telemedicine.     

Pb-free surface-finishing on electronic components’ terminals for Pb-free soldering assembly

Pb-free solderable surface finishing is essential to implement Pb-free solder assembly in order to meet with the growing demand of environmental consciousness to eliminate Pb from electronic products. Two types of widely applicable Pb-free surface finishing technologies are developed. One is the multilayer-system including Pd with Ni undercoat. Heat-resistance of Pd enables whole-surface-plating on to leadframe before IC-assembling process. The other is the double-layer-system with low-melting-point-materials, for example, thicker Sn underlayer and thinner Sn-Bi alloy overlayer, dilutes Sn-Bi alloy’s defects of harmful reactivity along with substrate metal and mechanical brittleness with keeping its advantages of solder-wettability and no whisker.     

Mechanical properties and thermal aging behavior of styrene‐butadiene rubbers vulcanized using liquid diene polymers as the plasticizer

The mechanical properties of styrene‐butadiene rubber (SBR) vulcanizates prepared using various plasticizers including liquid polybutadiene and styrene‐butadiene copolymers were investigated. The effect of the liquid polymers as the plasticizers on the mechanical properties of the polymers, such as the hardness, tensile storage modulus, tanδ, and the modulus at 100% elongation values, were determined before and after the thermal aging. As a result, it was revealed that the use of these liquid polymers gave less amount of change in the measurement values for the mechanical properties during the aging. The crosslinking density and the amount of free polymers were also determined on the basis of the swelling and extraction data, respectively, using several organic solvents. These results support the fact that the added liquid polymers are fixed to the SBR networks. We revealed the superiority of the liquid styrene‐butadiene copolymers as the plasticizer, which provides sufficient mechanical properties after vulcanization and the excellent maintenance of the properties during the thermal aging process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Spherical approximation for multiple cameras in motion estimation: Its applicability and advantages

Estimating motions of a multi-camera system which may not have overlapping fields of view is generally complex and computationally expensive because of the non-zero offset between each camera’s center. It is conceivable that if we can assume that multiple cameras share a single optical center, and thus can be modeled as a spherical imaging system, motion estimation and calibration of this system would become simpler and more efficient.     

Hydroboration copolymerization

Summary Organoboron copolymers were prepared by polyaddition of diene mixture or diene/diyne mixture, respectively, with thexylborane (1). When a mixture of dienes such as 1,2-diallyloxyethane (2a) and p-diallylbenzene (2b) was polymerized with 1, the peaks in GPC using both UV and RI detectors were shifted to higher molecular weight regions with the increase of the amount of 1. The molecular weight distribution of the copolymer obtained by this method indicated clear difference from that of a mixture of two homopolymers. On the other hand, when the poymerization between 1 and 1,7-octadiene (2c) was carried out in the presence of a trace amount of 1,7-octadiyne (4), the molecular weights of organoboron polymers were found to be increased when the ratio of 4/2c was increased.