Spreading behavior of polymerizable monolayers of acrylamides with double alkyl chains and polymerization of the LB films

The spreading behavior of N,N'-dialkylacrylamide (dAAs) monomers on a water surface is investigated by measurement of surface pressure-area isotherms as a function of alkyl chain length and temperature. The monolayers of dAAs can be classified into three types. (I) N,N'-dioctadecylacrylamide (dODA) shows a rapid increase in surface pressure indicating formation of a rigid condensed monolayer; (II) the isotherm of N,N'-dihexadecylacrylamide (dHDA) has a plateau region in surface pressure corresponding to a phase transition from a expanded form to a condensed form, which corresponds to gel-liquid crystal phase transition often observed in biomembranes; and (III) the dialkylacrylamides with alkyl chain length shorter than the hexadecyl group form expanded monolayers with no condensed monolayer at any temperature. The similar three kinds of monolayers are also observed in the isotherms for dHDA monolayer as a function of temperature. It is found that two carbon elongation in double alkyl chains causes the same effect on the monolayer induced by about 10 °C cooling. Under various conditions, only liquid condensed monolayers are transferred on to a solid support, yielding the monomer LB films, practically, of dODA at any temperature and dHDA at low temperature. The polymerization of those LB films by UV irradiation was ascertained by the electronic absorption spectra.     

Direct current to 34.1-Gb/s, 19-Gb/s/cm/sup 3/ low-jitter parallel optical interconnecting module for high-speed memory test systems

A protocol-free parallel optical interconnecting module is introduced as a solution to solve memory test system transmission bottlenecks. The optical transmission system flexibly suited for a memory test system is reviewed and discussed. A parallel optical module capable of transmitting from dc to 34.1Gb/s (4.267 Gb/s /spl times/8 ch) has been developed. A data transmission throughput density per unit volume of 19 Gb/s/cm/sup 3/ is achieved. A random jitter of less than 3-ps root-mean-square is also achieved. Furthermore, high-density optical connector, high-density optical fiber cable, fiber guides, and cable management/reinforcement members suited for mechanical requirements of the memory test system have been developed.     

Government role and participation in development and marketing of soy protein foods

Japan has a history of utilizing soybeans as human foods. Currently, a great quantity of defatted soybeans is used as animal feed in Japan, and governmental and commercial enterprises are anxious to turn the defatted soybeans directly into foods for humans. Therefore, they are putting great efforts into soybean research and development. Since the demands for better foods are rising and their resources are not abundant, I feel that soybean protein will play an important role by exerting its unique properties, not only to supplement other foods, but also to grow into new types of foods when their unknown properties are disclosed.     

Changes of volatile components of tomato fruits during ripening

Volatile components obtained by simultaneous steam distillation-extraction from two varieties of tomato fruits at various ripening stages and their artificially ripened tomato fruits were analyzed by GC and GC-MS using a glass capillary column. One hundred and thirty compounds were identified. Of these, quantitative changes in the major thirty-six compounds were investigated. Hexanal, trans-2-hexenal, 2-iso-butylthiazole, 2-methyl-2-hepten-6-one, geranylacetone and farnesylacetone, which were estimated to be important volatile components of fresh tomato aroma by the GC-Sniff method, increased with natural and artificial ripening. However, many volatile components showed complicated changes in the case of artificially ripened tomato fruits.     

Appropriate lengths between phalanges of multijointed fingers for stable grasping

An appropriate arrangement of finger joints is very important since the stability of grasping an object greatly depends on that arrangement. Multijointed fingers can grasp an object with many points of contact each of which is pressed against the object as if wrapping up that object. The amount of the wrapped up area and the form of the finger when an object is grasped are therefore important factors for determining the stability of grasping. We propose the wrapping factor to be used for the evaluation of the stability of grasping by using these factors. We consider 28 models for the finger having three joints, and perform a simulation of their ability to grasp various shapes stably. Based on the simulation results, an appropriate arrangement of lengths between phalanges for a multijointed finger is presented.     

Effects of manufacturing conditions on the properties of coal-derived caking additives

Manufacturing conditions of coal-derived caking substances (SRC) were investigated to determine the effects of these conditions on the chemical and caking properties of the additives. The solvent-refined coal (SRC) produced in the early stage of digestion at the lower temperature, of which β- and γ-fractions were 55 and 35 wt %, respectively, consisted of a heterogeneous mixture characterized by a low aromaticity, long side-chains, and a large, average molecular weight. The Roga index of the SRC was large but its total dilatation was small. As the digestion proceeded, the condensation and the cycloaromatization reactions improved the homogeneous nature and decreased the molecular weight by the breakage of side-chains, dealkylation, and deoxidation, leading to increases in the γ-fraction and total dilation by decreases in the β-fraction and Roga index. Such trends were more marked when the conversion exceeded 90 wt %. The relation between structure and the caking properties of the SRC are discussed.     

Ethynylene-disilanylene copolymers

Polymers of structure (SiR₂SiR₂-C C-SiR₂SiR₂-C C) _n , in which ethynylene units alternate with disilylene units, have been prepared by two routes: (a) condensation of dichlorodisilanes with dilithium derivatives of 1,2-diethynyldisilanes and (b) ring-opening polymerization of strained cyclic disilanylene-acetylnes, (SiR₂SiR₂C C)₂. The polymers display UV absorption near 240 nm indicative of – conjugation between the Si₂ and the C C moieties. Polymers with R=R=n-Bu or R=n-Bu, R=Ph, undergo solid-state transitions to form liquid crystalline mesophases resembling those observed for many poly(silylenes). Single crystals were obtained for the polymer with R=R=CH₃, by precipitation from dilute cyclohexane solution. The solid-state properties and structures of this family of polymers are discussed.This paper was presented at the Second International Topical Workshop, Advances in Silicon-Based Polymer Science.