Color computer graphics in magnetic field analysis by means of the finite element method

The finite element method for electromagnetic fields is very popular because of its powerful numerical techniques. Since the output from the finite element analyses (F.E.A.) usually makes a pile of numerical data, it is very important to display them intelligibly and accurately in order to assist analysts in understanding and evaluating the results. Three post-processing methods in the F.E.A. using a multi-color pen plotter or a color CRT are proposed: (1) Depiction of magnetic flux lines in two or three dimensional fields by using a multi-color pen plotter, (2) Depiction of magnetic flux density distribution with flux lines in two dimensional fields by using a color CRT, (3) Depiction of error distribution by using a color CRT.

By using these three methods analysts can visually grasp the behavior of the magnetic fields and the error distribution in detail.     

Numerical analysis of an axial-mode zigzag antenna

The radiation characteristics of an axial-mode zigzag antenna are evaluated on the basis of the numerically determined current distribution. It is revealed that the frequency at which the maximum gain is obtained decreases as the number of zigzag cells is increased, and that an antenna of two zigzag cells has a high power gain of about 11 dB with a bandwidth of about 11%, although the number of zigzag cells is extremely small.     

Association of Dolichos biflorus lectin binding with full differentiation of bovine trophoblast cells

Binucleate cells in ruminant placenta are differentiated from fetal mononucleate trophoblast cells and secrete many glycoproteins. This study characterized bovine placental binucleate cells in primary culture and a bovine trophoblastic cell line (BT-1) with an N-acetyl-galactosamine-binding lectin, Dolichos biflorus agglutinin (DBA). DBA specifically bound to the surface membrane and the cytoplasm of binucleate cells. Mononucleate epithelial cells and fibroblasts were free of DBA. DBA-positive binucleate cells corresponded to the fully matured cells, producing placental lactogen, and the cytoplasm was devoid of cytokeratin. Binucleate cells assumed a flattened shape on a collagen substratum in an extended culture, and entered a dedifferentiated state with a degranulation of placental lactogen. In these flattened cells, DBA reactions were attenuated in the cytoplasm. DBA binding in BT-1 was subsequently examined. BT-1 was derived from blastocysts produced in vitro and is trophectodermal as shown by the expression of cytokeratin. BT-1 was able to differentiate into placental lactogen-producing binucleate cells on a collagen gel substratum. Cytokeratin expression in BT-1 was downregulated with the differentiation into binucleate cells. However, DBA bound to neither mononucleate nor the differentiated binucleate cells in BT-1. These results indicate that binucleate cells in vivo but not binucleate cells derived from BT-1, specifically developed glycoconjugates recognized by DBA. The glycoconjugate expression was associated with fully differentiated cells. The onset of DBA binding in binucleate cells coincides with placental development, and binucleate cells differentiated from BT-1 cell cultures may reflect those cells at earlier stages of gestation.     

Efficient generation of plane trees

A rooted plane tree is a rooted tree with a left-to-right ordering specified for the children of each vertex. In this paper we give a simple algorithm to generate all rooted plane trees with at most n vertices. The algorithm uses O(n) space and generates such trees in O(1) time per tree without duplications. The algorithm does not output entire trees but the difference from the previous tree. By modifying the algorithm we can generate without duplications all rooted plane trees having exactly n vertices in O(1) time per tree, all rooted plane trees having at most n vertices with maximum degree at most D in O(1) time per tree, and all rooted plane trees having exactly n vertices including exactly c leaves in O(n−c) time per tree. Also we can generate without duplications all (non-rooted) plane trees having exactly n vertices in O(n³) time per tree.     

Tapered backfire helical antenna with loaded termination

In order to improve the radiation characteristics of a backfire bifilar helical antenna, a means of terminating the arm ends with a resistor is numerically and experimentally investigated. Owing to the reduction of reflected current, the present backfire helix realises an excellent front-to-back ratio and axial ratio, while maintaining inherent absolute gain.     

New 1.5 ?m wavelength GaInAsp/InP distributed feedback laser

A new 1.5 ?m-wavelength GalnAsP/InP distributed feedback buried-heterostructure laser was fabricated by a three-step LPE growth process. The second-order corrugation grating was formed on the waveguide layer grown on the active layer. High differential quantum efficiency of 13%/facet was obtained. Single-longitudinal-mode operation in the temperature range from ?20°C to 55°C was obtained.     

Preparation of tri-O-benzylcellulose by the use of nonaqueous cellulose solvents

A procedure has been developed for preparing tri-O-benzylcellulose with higher yields than 90%. In this procedure, cellulose was dissolved in a nonaqueous cellulose solvent, SO₂–diethylamine (DEA)–dimethyl sulfoxide (DMSO), and then powdered sodium hydroxide was added. To the suspension thus prepared, benzyl chloride was added in four portions under heating. Chemical and physical properties of tri-O-benzylcellulose were studied, and tri-O-benzylcellulose prepared from microcrystalline cellulose powder shows the characteristic of thermotropic liquid crystal.     

Stabilization of affinity-tagged recombinant protein during/after its production in a cell-free system using wheat-germ extract

We found that the affinity tag fused to the carboxyl (C-) terminal of a single-chain Fv (scFv) antibody was proteolytically degraded in a wheat germ cell-free protein synthesis system. The addition of two extra residues of glycine to the tail of the cMyc tag significantly increased the stability of the tag, suggesting that wheat endogenous carboxypeptidase(s) play a primary role in the C-terminal tag-specific degradation. In addition to the modification of the tag sequence, addition of diisopropyl fluorophosphate, which is known as an inhibitor of carboxypeptidases, prevented the cMyc tag sequence degradation. The effects of other protease inhibitors on the translation reaction and stability of the synthesized protein are also reported.     

Solving function distribution and behavior design problem for cooperative object handling by multiple mobile robots

This paper addresses the function distribution and behavior design problem for a multirobot system which incorporates a behavior-based dynamic cooperation strategy for object handling. The proposed multiple robot system is composed of a managing robot and homogeneous behavior-based robots. The cooperation strategy in this system is realized in two steps: designing the distributed robot's cooperative behavioral attributes according to the robot's abilities, and organizing these behavioral attributes so that team cooperation is realized. For indicating an incremental style of local behavior construction, an advanced design of cooperative behavior for coping with unknown disturbance is addressed. Additionally, two extended cooperation strategies designed for a path tracking task are described. These three strategies are based on the same concept on performing manipulation in coordination. Therefore, by considering the function distribution among the managing robot and worker robots, and considering behavior design of each worker robot, the proposed system is able to achieve the object handling task with different performances according to the task requirement, such as with or without path tracking and with or without contact with the environment. Experimental results demonstrate the applicability of the proposed system.