Structural analysis of β-form poly(p-xylyene) starting from a high-resolution image

The crystal structure of β-form poly(p-xylylene) is analysed starting from a high-resolution image of a single crystal of this polymer. The high-resolution image corresponding to the projection of molecules onto the ab-plane along the chain axis shows clearly the mutual position of each molecule in a unit cell. The molecules are aligned wavily in the direction along the a-axis and the rough positions of their centres in a unit cell can be determined from the image. The refinement of the structure is carried out by the usual least-squares method using the intensities of electron and X-ray diffractions. The space group of the β-form is trigonal, P3, and the lattice dimensions are a=2.052 nm, c=0.655 nm and γ=120°. The unit cell contains 16 molecules and one of them is considered to occupy statistically one of three equivalent orientations so as to satisfy the P3 symmetry.     

Tree-structured generation of orthogonal spreading codes withdifferent lengths for forward link of DS-CDMA mobile radio

Tree-structured generation of orthogonal spreading codes with different lengths is presented for orthogonal multiplexing of forward-link code-channels of different data rates in direct sequence code division multiple access DS-CDMA mobile radio. The bit error rate performance under a multi-user environment suffering multipath Rayleigh fading is evaluated by computer simulation     

Semiautomatic leakage analyzing system for time series fluorescein ocular fundus angiography

An algorithm for measuring an index of leakage in fluorescein fundus angiography is presented. The number of pixels whose gray level exceeds an automatically determined slice level is calculated. An automatic blood vessel elimination technique is introduced. Further, a method of measuring the short term change of leakage from a time series of the fluorescein fundus angiographs is described. Our system can also deal with the time series images obtained on different occasions (long term change).The features of this paper are: (1) this paper deals with double time sequence images (short and long term); (2) an automatic blood vessel recognition algorithm is employed.     

Selective Ion Permeation Across Membranes Prepared from Steroidal Crown Ethers

Five crown ethers covalently-linked to the cholesterol skeleton were synthesized. Thermal analysis established that four of them have a cholesteric liquid-crystal phase. In particular, the monobenzo-13–crown-4 covalently-linked through an ethylene spacer to the cholesterol skeleton shows a stable cholesteric mesophase even at room temperature. The stable cholesteric mesophase at room temperature was also obtained by mixing two steroidal crown compounds. These mixed systems were embedded in a polymer matrix and the polymer/liquid-crystal composite membranes were subjected to ion-permeation experiments. It was found that the permeation selectivity is basically explained by the hole-size selectivity in the crown-metal interaction. In particular, composite membranes containing a monobenzo-13–crown-4 unit showed the remarkably high Li⁺ selectivity. It was concluded on the basis of examination of activation parameters that ion permeation occurs across channel-like stacks of crown ether rings.     

Measurement of heat of mixing for ammonium chloride + ammonia system at 25 °c

Heat of mixing for ammonium chloride in liquid ammonia at 25°C was determined in the concentration range 0-50 wt% NH₄Cl. It was calculated from the differential heat of solution observed in this work and the differential heat of dilution estimated from activities of solvent. A twin isoperibol calorimeter consisting of two stainless Dewar vessels was used at a relatively high pressure (up to 1.5 MPa). The accuracy of this calorimetry was examined by measuring the heat of solution for tris-(hydroxymethyl)aminomethane(THAM) in 0.1 kmol/m³ HCl at 25°C, and satisfactory agreement within 1.1% between experimental and literature value was obtained. The reproducibility for the experiment was within 2.8%.     

Epitaxial synthesis of poly(p-xylylene)

When poly(p-xylylene) is synthesized from gaseous monomers, it grows epitaxially on substrates. The effects of the substrate and annealing on the epitaxy are examined by growing the polymer on cleavage (001) surfaces of four kinds of alkali halides (NaCl, KCl, KBr and Kl). The polymer crystallizes with its chains oriented along the 〈100〉 and 〈010〉 directions of the substrates and the faster growth planes are parallel to the (001) plane of substrate, i.e., the (010) plane of the α-form crystal and the (100) plane of the β-form. The degree of orientation is the highest on KBr and the lowest on NaCl. The lattice matching requirement is important in the epitaxial synthesis. The observed orientation of the polymer chain on each substrate is compared with the orientation expected from a minimum of interfacial potential energy calculated on the basis of dispersion-repulsive forces between atoms in the polymer and ions in the substrate. The orientational angle of polymer chain on the substrates and the degree of its orientation are qualitatively explained in terms of the processes of monomer deposition, polymerization and crystallization under the directive influence of the substrate.     

Multifunctional effects of anticomplementary agent K-76 on carrageenan-induced colitis in the rabbit

The recently described synthesis of ferric adsorbent paper has made possible the modification of protein kinase assays. The adsorbent contains ferric chelate groups, which are responsible for the binding of phosphopeptide via phosphate group. The selective adsorption of phosphopeptide contra nonphosphorylated peptide allows the use of tritium-labeled peptides and unlabeled ATP as substrates. The binding of the reaction product to the adsorbent was complete and was not affected by the amino acid sequence of the peptide. The conditions required for the separation of the produced phosphopeptide from the initial peptide have been worked out as well. The firmly bound phosphopeptide should be released from the ferric adsorbent paper prior to liquid scintillation counting. Using 0.1 m NH4HCO3 solution (pH 8.0), the elution of phosphopeptides was almost complete. The modified protein kinase assay proposed herein is rapid and allows handling of multiple samples simultaneously. In addition, the ferric paper method avoids the use of 32P-isotope, replacing it with 3H which has lower radiation energy and a much longer half-life.     

Photoresponsive Crown Ethers. Part 11. Azobenzene-Pillared Cylindrical Macrocycle As a Photoresponsive Receptor

A cylindrical ionophore (1) in which two diaza-crown ethers are linked by two azobenzene pillars serves as a photoresponsive host molecule. In alkaline solution containing K⁺, (1) forms a cascade complex with dianionic guest molecules, but photoirradiated (1) which has a shortened cylinder cannot bind the guest molecules so effectively as (1). (1) solubilised in acidic aqueous solution by protonation of four tertiary nitrogens provides a hydrophobic cavity to bind several anionic azo dyes. The association is also suppressed by photoirradiation. The results indicate that parallel array of the azobenzene segments in (1) provides a host cavity and the photoinduced structural change is readily reflected by the association tendency. This is the first example for the photoresponsive inclusion complex.     

Robot language from the standpoint of FA system development—An outline of FA-BASIC

A new unified FA (Factory Automation) language has been developed. The language is suited for robot control, vision system control and programmable controller (PC) control and enables a unified means for programming. The language is called FA-BASIC and has common functions such as expression, control structure and input/output statement based on BASIC language.

FA-BASIC is composed of three subsystems: FA-BASIC/R for robot control, FA-BASIC/V for vision system control and FA-BASIC/C for PCs.

Many languages have been developed up to now, but most of them were aimed at single purposes. These single purpose languages were too limited when developing an integrated FA system, because several languages and different program-making methods must be mastered.

Using FA-BASIC, programming with mutual interconnections between robots, PCs and vision devices is done by the one common method.

In this paper, the basic design concept and functions of FA-BASIC will be presented, along with the features of FA-BASIC/R and on outline of a robot control system using a standard mechanism-independent intermediate language and standard fundamental modules. Also, for easy programming, an off-line programming system with graphical aids and a menu-selection method which require no special effort to master will be introduced as the only present-day universal robot programming method.