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Control of various morphological changes of poly(meth)acrylate microspheres and their swelling degrees by SPG emulsification

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Journal of Polymer science 2000年第22期38卷

作者： Sumalee Tawonsree Shinzo Omi Suda Kiatkamjornwong Multidisciplinary Program of Petrochemistry and Polymer Science Faculty of Science Chulalongkorn University Bangkok 10330 Thailand Graduate School of Bio-Application and System Engineering Tokyo University of Agriculture and Technology 2-24-16 Nakamachi Koganei Tokyo 184 Japan Department of Imaging and Printing Technology Faculty of Science Chulalongkorn University Bangkok 10330 Thailand

Crosslinked poly(meth)acrylate polymers with a variety of morphologies were synthesized with two steps. In the first step, a microporous glass membrane (Shirasu Porous Glass, SPG) was employed to prepare uniform emulsion droplets by applying an adequate pressure to the monomer phase, which was composed of the ADVN initiator, solvent of toluene or heptane or their mixture, and a mixture of (meth)acrylate monomers. The droplets were formed continuously through the membrane and suspended in the aqueous solution, which contained a PVA-127 suspending agent, SLS emulsifier, and NaNO 2 inhibitor to suppress the nucleation of secondary particles. SPG pore sizes of 0.90, 5.25, and 9.25 μm were used. Then the emulsion droplets were polymerized at 343 K with a rotation rate 160 rpm for 24 h. The (meth)acrylate monomers 2-ethylhexyl acrylate (2-EHA), 2-ethylhexyl methacrylate (2-EHMA), cyclohexyl acrylate (CHA), methyl methacrylate (MMA), lauryl acrylate (LA), and lauryl methacrylate (LMA) were used in this research. The influences of the ratios of the monomer and crosslinking agent EGDMA, the amount of diluents, the monomer type on the polymer particle morphology, the swelling degree, and the polymer particle size were investigated. It was found that an increase in the concentrations of EGDMA and heptane resulted in higher coarse porous spheres and smaller polymer particle sizes. A coefficient with a variation close to 10%, or a standard deviation of about 4, was obtained. The capacity of these spheres as solvent absorption materials was examined. The highest swelling degrees of heptane and toluene were obtained when LA was employed as the monomer with 30% (by weight) of EGDMA and 70% (by weight) of heptane as an inert solvent. The highest capacity of the solvent absorption was obtained when using a polymer particle size of 4.81 μm, as prepared by SPG pore size 0.9 μm. The polymer particles were able to absorb aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and

关键词： Shirasu porous glass 2-ethyl hexyl acrylate 2-ethyl hexyl methacrylate cyclohexyl acrylate methyl methacrylate lauryl acrylate swelling degree crosslinking agent diluent solvent absorption

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Folding-unfolding of goat α-lactalbumin studied by stopped-flow circular dichroism and molecular dynamics simulations

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Proteins: Structure, Function, and Bioinformatics 2000年第1期42卷

作者： Takao Yoda Minoru Saito Munehito Arai Katsunori Horii Kouhei Tsumoto Masaaki Matsushima Izumi Kumagai Kunihiro Kuwajima Department of Physics School of Science University of Tokyo Tokyo Japan Faculty of Science and Technology Hirosaki University Bunkyo-cho Hirosaki Japan Department of Biomolecular Engineering Tohoku University Aramaki Aoba-ku Sendai Japan Rational Drug Design Laboratories Matsukawa Fukushima Japan

Folding reaction of goat α-lactalbumin has been studied by stopped-flow circular dichroism and molecular dynamics simulations. The effects of four single mutations and a double mutation on the stability of the protein under a native condition were studied. The mutations were introduced into residues located at a hydrophobic core in the α-domain of the molecule. Here we show that an amino acid substitution (T29I) increases the native-state stability of goat α-lactalbumin against the guanidine hydrochloride-induced unfolding by 3.5 kcal/mol. Kinetic refolding and unfolding of wild-type and mutant goat α-lactalbumin measured by stopped-flow circular dichroism showed that the local structure around the Thr29 side chain was not constructed in the transition state of the folding reaction. To characterize the local structural change around the Thr29 side chain to an atomic level of resolution, we performed high-temperature (at 400 K and 600 K) molecular dynamics simulations and studied the structural change at an initial stage of unfolding observed in the simulation trajectories. The Thr29 portion of the molecule experienced structural disruption accompanied with the loss of inter-residue contacts and with the water molecule penetration in the 400-K simulation as well as in four of the six 600-K simulations. Disruption of the N-terminal portion was also observed and was consistent with the results of kinetic refolding/unfolding experiments shown in our previous report. Proteins 2001;42:49–65. © 2000 Wiley-Liss, Inc.

关键词： protein folding transition state hydrophobic core high-temperature simulation early stage of unfolding

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Wavelet analysis of strong response records of building with biunear restoring force

Wavelet analysis of strong response records of building with...

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ASME 1999 design engineering Technical Conferences, DETC 1999

作者： Segawa, Ryutaro Yamamoto, Shizuo Sone, Akira Masuda, Arata Department of Mechanical and System Engineering Faculty of Engineering and Design Kyoto Institute of Technology Matsugasaki Sakyo-ku Kyoto606-8585 Japan

ISBN: (纸本)9780791819777

It is very important to estimate the residual life of structures by analysing a strong response quantitatively, because it is necessary to judge whether they can be used or not in the future, after they are damaged by earthquakes. During a strong earthquake, the jerk response of & structure with bilinear restoring force has discontinuity, just when the restoring force changes rapidly from the elastic region to the plastic region. Authors have tried to detect the discontinuity in the jerk by using wavelet analysis and reported a successful paper (Sone, et ah, 1994). The final goal of study is to estimate the low cycle fatigue of structure by analysing the observed records in a structure. For this object, the relationship between ductility factor;that is the ratio of peak relative displacement and yield relative displacement, and the number of discontinuity detection is needed. In this paper, the method is proposed to estimate the ductility factor of structure by the wavelet analysis of absolute acceleration response. Wavelet has the ability to detect discontinuity in acceleration response record;furthermore, it is found in this study that the wavelet coefficient is proportional to the velocity at the yield point. Besides, the ductility factor is estimated from the velocity at yield point by using the energy balance between kinetic energy at the yield point and strain energy from the yield point to the maximum relative displacement. Thus, using these relationships, the ductility factor is estimated from wavelet coefficient obtained by wavelet analysis of acceleration response. The applicability of this method is verified through some simulations. Copyright © 1999 by ASME

关键词： Wavelet analysis

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Decentralized control of redundant manipulators: a control scheme that generates a cyclic solution to the inverse problem

Decentralized control of redundant manipulators: a control s...

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IEEE/ASME (AIM) International Conference on Advanced Intelligent Mechatronics

作者： Y. Yan K. Ohnishi T. Fukuda Department of Mechanical Engineering Faculty of Engineering University of Ryukyus Okinawa Japan Department of System Design Engineering Faculty of Science and Technology Keio University Yokohama Japan Department of Micro System Engineering University of Nagoya Nagoya Japan

A decentralized control scheme is proposed for three-dimensional (3-D) positioning of spatial redundant manipulators having all rotational joints. A cyclic kinematic algorithm is introduced that generates a closed joint-space trajectory corresponding to a closed end-effector path in Cartesian space. Cyclicity is a very important property for manipulators that must perform repeated tasks without the requirement for intermediate re-configuration maneuvers. Once the joint-space trajectory is generated, control of the manipulator becomes a joint-based control; independent control units for each joint are formed by the implementation of a proportional/derivative (PD) feedback controller and a disturbance observer at each joint. The validity of the proposed control scheme is shown by several simulations on multi-jointed redundant spatial manipulators and by experimental results from a 6-link planar redundant manipulator.

关键词： Distributed control Kinematics Manipulators Inverse problems PD control Proportional control Trajectory Closed-form solution Adaptive control Helium

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Preparation and ionic substitution of Dion-Jacobson type compounds CsLa(M,Mn)nO3n+1 (M = Nb, Ta;n = 2,3)

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Key engineering Materials 1999年 169卷 243-246页

作者： Takakuwa, S. Saitoh, T. Toda, K. Kanamaru, F. Department of Manufacturing System Grad. Sch. of Science and Technology Niigata University 8050 Ikarashi Ninocho Niigata-city Niigata 950-2181 Japan Department of Chemical Faculty of Engineering Niigata University 8050 Ikarashi Ninocho Niigata-city Niigata 950-2181 Japan

Dion-Jacobson type compound, CsLa2NbMn2O10, containing Mn ion as a transition metal was prepared by a conventional solid state reaction for the first time. Cesium ions in this compound can be exchanged by lithium ions. Crystal structure of new compound, CsLa2NbMn2O10, was estimated by simulation of X-ray diffraction pattern. Lithium ion-exchange changes the space group of this layered perovskite from P4/mmm to body-center I4/mmm.

关键词： Cesium compounds

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Automatic face recognition using neural networks

Automatic face recognition using neural networks

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International Conference on Microelectronics, ICM

作者： H.M. El-Bakry M.A. Abo-Elsoud M.S. Kamel Faculty of Computer Science &Information System Mansoura University Egypt Electronics & Elec. Comm. Department Faculty of Engineering Mansoura University Egypt System Design Engineering Department University of Waterloo Canada

Automatic recognition of individuals is a significant problem in the development of pattern recognition. In this paper, we introduce a simple technique for personal identification of human faces in cluttered scenes based on neural nets. In the detection phase, neural nets are used to test whether a window of 20/spl times/20 pixels contains a face or not. A major difficulty in the learning process comes from the large database required for face/nonface images. We solve this problem by dividing the data into two groups. Such division results in reduction of computational complexity, thus decreasing the time and memory needed during the image test. For the recognition phase, feature measurements are made through Fourier descriptors. Such features are modified to reduce the number of neurons in the hidden layer. Simulation results for the proposed algorithm show good performance compared with previous results.

关键词： Face recognition Neural networks Face detection Pattern recognition Testing Humans Layout Phase detection Image databases Spatial databases

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Intelligent motion task planning of redundant parallel manipulator

JSME International Journal, Series C: Dynamics, Control, Rob...

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JSME International Journal, Series C: Dynamics, Control, Robotics, design and Manufacturing 1999年第1期42卷 203-209页

作者： Ogawara, Tomohiro Nakazawa, Kazuo Faculty of Science and Technology Dept. of System Design Engineering Keio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan Faculty of Science and Technology Department of Mechanical Engineering Keio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan

In this study, a robot that utilizes a parallel mechanism at parts of its body is proposed. The robot combines locomotion and manipulation, and consists mainly of four units of three degree of freedom (hereafter called DOF) parallel mechanism with linear actuators and two grippers attached to both sides of its body. The robot has high redundancy with 14-DOF without grippers. The purpose of this study is to realize the 'intelligent motion' in the redundant parallel manipulator that performs the basic motion of the proposed robot. The robot determines its motion while considering its redundancy and improves it using actuator information derived from the motion. First, we analyze the kinematics and statics about the parallel manipulator, and show a method to optimize the solution of inverse kinematics that includes the redundancy problem. Next, we discuss the intelligent motion task planning of the parallel manipulator using actuator information. Two methods are proposed based on the optimization of inverse kinematics. One optimizes the motion by iteration. The other optimizes the motion successively in continuous motion tasks. Finally, the effectiveness of the proposed methods is verified experimentally.

关键词： Motion planning

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Tri-output cellular neural network and its application to diagnosing liver diseases

Tri-output cellular neural network and its application to di...

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IEEE International Conference on systems, Man and Cybernetics

作者： Zhong Zhang Zhi-Qiang Liu H. Kawabata Department of System Engineering Industrial Technology Center of Okayama Okayama Japan Faculty of Computer Science and System Engineering Okayama Prefectural University Soja Japan

The saturation (output) function is important to cellular neural networks (CNN) because it affects the operation, stable equilibrium points, and the performance of CNN. However, to the best of our knowledge, a systematic design procedure for the output function is not available in the literature. In this paper, we present a simple, yet effective design method for the tri-output cellular neural network (TCNN). To demonstrate the effectiveness of the output function using our design procedure, we tested TCNN on synthesized images. In addition, we applied the tri-output cellular neural network to the diagnosis of liver diseases and obtained very encouraging results.

关键词： Cellular neural networks Liver diseases Differential equations systems engineering and theory Computer science design methodology Application software Computer industry Testing Network synthesis

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Nonlinear transport phenomena in a superconductive ceramics of YBa2Cu4O8 at the intergrain ordering

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AIP Conference Proceedings 1999年第1期469卷 549-550页

作者： Takeshi Yamao Naoto Nishimura Makoto Hagiwara Motohiro Matsuura Department of Electronics and Information Science Faculty of Engineering and Design Kyoto Institute of Technology Matsugasaki Sakyo-ku Kyoto 606-8585 Japan

Takeshi Yamao, Naoto Nishimura, Makoto Hagiwara, Motohiro Matsuura; Nonlinear transport phenomena in a superconductive ceramics of YBa2Cu4O8 at the intergrain o

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Position-based impedance control using a fuzzy compensator

Position-based impedance control using a fuzzy compensator

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International Conference on Knowledge-Based Intelligent Information engineering systems (KES)

作者： F. Nagata K. Watanabe K. Izumi Fukuoka Industrial Technology Center Interior Design Research Institute Fukuoka Japan Department of Advanced Systems Control Engineering Graduate School of Science and Engineering Japan Department of Mechanical Engineering Faculty of Science and Engineering Saga University Honjomachi Saga Japan

A position based impedance control with a fuzzy compensator is proposed to improve a force control performance, in which the environment has unknown dynamics or curved surface. The main attraction of the fuzzy compensator is that it generates proper position compensation as feedforward command so that overshoots and oscillations in the direction of force control can be suppressed satisfactorily. Profiling control simulations using the dynamics of the PUMA560 manipulator are shown to demonstrate the effectiveness and promise of the fuzzy compensator under the environment having unknown dynamic characteristics.

关键词： Fuzzy control Force control Industrial control Manipulator dynamics Control systems Surface impedance Service robots Electrical equipment industry Electronic mail design engineering

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