Effect of Residual Chlorine on Ir-Catalyzed Reaction of Solid CaO with Gas Mixtures of Methane and Water Vapor

The effect of residual chlorine on the metal-catalyzed reaction of solid calcium oxide with a gas mixture of methane and water vapor (CaO + CH₄ + 2H₂O → CaCO₃ + 4H₂) is investigated at temperatures in the range 613–713 K, using solid samples of Ir/CaO prepared by TPR of Ir/CaCO₃ with different chlorine contents below 1.1%. Chlorine-containing samples exhibit anomalous reaction curves characterized by the initial slow and linear progress followed by abrupt acceleration, while chlorine-free samples react more rapidly from the beginning to give simple curves without any acceleration. In both cases, apparent activation energy of 170–190 kJ/mol and reaction order of 0.8–1.0 with respect to methane pressure are determined, demonstrating that the presence of chlorine does not affect the kinetics of the reaction. Thus, the large difference in initial rate is considered to reflect the inhibiting role of residual chlorine. Based on these findings together with the data on surface properties of Ir/CaO, a model is proposed to explain the accelerative progress observed when residual chlorine is present.     

New polylactide-layered silicate nanocomposites. 2. Concurrent improvements of material properties, biodegradability and melt rheology

Our continuing research on the preparation, characterization, materials properties, and biodegradability of polylactide (PLA)-layered silicate nanocomposites has yielded results for PLA-montmorillonite nanocomposites. Montmorillonite modified with trimethyl octadecylammonium cation was used as an organically modified layered silicate for the nanocomposites preparation. The internal structure of the nanocomposites in the nanometer range has been established by using wide-angle X-ray diffraction and transmission electron microscope analyses. All the nanocomposites exhibited superior improvement of practical materials properties such as storage modulus, flexural modulus, flexural strength, heat distortion temperature, and gas barrier property as compared to that of neat PLA. The biodegradability of neat PLA and a representative nanocomposite was also studied under compost, and the rate of biodegradation of neat PLA significantly increased after nanocomposites preparation. The melt rheology of neat PLA and various PLACNs was also studied.     

Oxidative dehydrogenation of propane over magnesium molybdate catalysts

Catalytic activities of magnesium molybdates were investigated for the oxidative dehydrogenation of propane with and without molecular oxygen under atmospheric pressure. Catalytic properties drastically changed with the catalyst composition, and it turned out that Mg_0.95MoO_x catalysts having slight excess molybdenum showed the highest activity in the oxidative dehydrogenation of propane, which gave 61% selectivity to propene at 22% conversion of propane at 515°C. The catalytic activities strongly depended on the acidic properties of the catalysts. It was also revealed that the lattice oxide ions of the catalysts participated as an active oxygen in the oxidative dehydrogenation of propane.     

Electrical and thermal conductivities of polyethylene composites filled with biaxial oriented short-cut carbon fibers

Polyethylene composites filled with various types of carbon fiber were prepared for electrical and thermal conductivity measurements. By estimation of the anisotropic parameter (Hermans' parameter), the fibers were confirmed to be significantly biaxially oriented in the composites. The critical volume fractions in the electrical conductivity of these composites for the two oriented directions (X and Y) were equal to each other and smaller than that for a direction (Z) vertical to the above. The electrical anisotropy, i.e., ratio of electrical conductivity of the composite for the Z direction to the X and Y directions varied drastically with increase in filler content. The longer the length of carbon fiber was, the higher became the electrical conductivity of the biaxially oriented carbon fiber composites for all directions. But, the thermal conductivity of the composite was almost unchanged for the Z direction, even if fiber length was sufficiently long. Our equation, previously proposed, proved adaptable to these thermal conductivities. The factors of C_p and C_f in the equation are kept unchanged, in spite of increasing fiber length. © 1994 John Wiley & Sons, Inc.     

Dyeing natural fibres in supercritical carbon dioxide using a nonionic surfactant reverse micellar system

A reverse micellar system in supercritical carbon dioxide has been developed as a dyeing medium. Water-soluble dyes such as reactive dyes and acid dyes could be sufficiently solubilised in the interior of a specially constituted reverse micelle. Protein fabrics, silk and wool, were satisfactorily dyed even in deep shades with conventional acid dyes without any special pretreatment. Cotton cellulose fabric was also dyed with conventional reactive dyes when the electrostatic force of repulsion between dye and cotton was eliminated. Compared to previously proposed supercritical dyeing methods, dyeing of fabrics with this system could be performed at low temperatures and pressures in a short time.     

Polymer‐Stabilized Micropixelated Liquid Crystals with Tunable Optical Properties Fabricated by Double Templating

Self‐organized nano‐ and microstructures of soft materials are attracting considerable attention because most of them are stimuli‐responsive due to their soft nature. In this regard, topological defects in liquid crystals (LCs) are promising not only for self‐assembling colloids and molecules but also for electro‐optical applications such as optical vortex generation. However, there are currently few bottom‐up methods for patterning a large number of defects periodically over a large area. It would be highly desirable to develop more effective techniques for high‐throughput and low‐cost fabrication. Here, a micropixelated LC structure consisting of a square array of topological defects is stabilized by photopolymerization. A polymer network is formed on the structure of a self‐organized template of a nematic liquid crystal (NLC), and this in turn imprints other nonpolymerizable NLC molecules, which maintains their responses to electric field and temperature. Photocuring of specific local regions is used to create a designable template for the reproducible self‐organization of defects. Moreover, a highly diluted polymer network (≈0.1 wt% monomer) exhibits instant on–off switching of the patterns. Beyond the mere stabilization of patterns, these results demonstrate that the incorporation of self‐organized NLC patterns offers some unique and unconventional applications for anisotropic polymer networks.     

Immunization with the "immunogenic peptide" of TSH receptor induces oligoclonal antibodies with various biological activities

Balb/c mice were immunized with a synthetic peptide (P354-14) corresponding to "the immunogenic peptide" of human thyrotropin receptor (hTSH-R). Through screening for binding to the peptide, we obtained several monoclonal antibodies with various biological activities: thyroid stimulation (SAb), inhibition of TSH stimulation (BAb) and no significant effect on cAMP production. One of the stimulatory clones was further studied. This clone enhanced cAMP production in Cos-7 cells transformed with the truncated TSH-R cDNA deleting the immunogenic peptide. These results indicated that the immunogenic peptide of the TSH-R induces oligoclonal anti-TSH-R antibodies, although the region is not essential for the functional epitope.     

Optimal patrolling methodology of mobile robot for unknown visitors

This paper focuses on patrolling missions for monitoring visitors in an environment. A single mobile robot is used. For the robot, it is required to monitor as many visitors as possible utilizing the mobility and monitoring capabilities. A challenge in the patrolling missions is that the robot does not have information about the visitors beforehand. For the unknown visitors, the robot is required to identify the trends. For this purpose, a Bayesian learning approach is applied to this robot. The identified visitor trends allow the robot to employ patrolling strategies. This is the adaptability of the patrolling robot to the unknown visitors. In this paper, we present an optimal patrolling strategy based on a value iteration method. The robot is enabled to have an optimal policy that suggests three patrolling decisions, such as the target monitoring area, monitoring time, and patrolling path in an integrated way. Furthermore, the optimal patrolling strategy is improved from the viewpoint of exploration and exploitation of information about the unknown visitors in the environment. Through simulation experiments, we discuss the effectiveness of the patrolling strategy.