Effects of 6-anilino-1,3,5-triazine-2,4-dithiol,zinc stearate,and barium stearate on the thermal stabilization of PVC

Individual action and synergistic effect in the combination of 6-anilino-1,3,5-triazine-2,4-dithiol (AF), zinc stearate, and barium stearate on the color stabilization of PVC were investigated. In this system, AF selectively reacts with allylic chlorine atoms in PVC. Consequently, unstable allylic chlorine units were converted to thermally stable allylic structures, thus retarding the development of polyene sequences. Zinc stearate accelerated the reaction of AF with allylic chlorine atoms in PVC, forming the zinc salts of AF (AFZ_nSt, St?C₁–H₃₅COO? ) by reacting with AF. Barium stearate reacted with ZnCl₂ which is formed in the above reaction to give St₂Zn and BaCl₂. Consequently, barium stearate led to the selective reaction of AF with allylic chlorine atoms in PVC and the remarkable retarding effect of discoloration of PVC.     

Prediction of the biologically active sites in eclosion hormone from the silkworm, Bombyx mori

The structure-activity relationship of eclosion hormone from the silkworm, Bombyx mori, was analyzed. First, the probable active residues in silkworm eclosion hormone and also tobacco hornworm eclosion hormone were predicted by the average distance map method. To examine the contributions of those residues to the activity of silkworm eclosion hormone, Gly-substituted mutants for those predicted residues were produced by site-directed mutagenesis and their activities were evaluated by a bioassay. Finally, Glu12, Met24 and Phe25 were estimated to be the crucial residues for the eclosion hormone activity. The possibility of the development of a blocker of an eclosion hormone receptor on the basis of the present work is also discussed.      

Asset Pricing and Productivity Growth: The Role of Consumption Scenarios

The paper analyzes the performance of asset prices implied by an aggregate macroeconomic growth model under two different consumption hypotheses: overlapping generations of agents with two period lives versus the infinitely lived agent. The production side of the economy is described by a random growth model with a competitive labor market and an exogenously given random dividend payout ratio. For an isoelastic technology with multiplicative production shocks this implies a random dynamical system for the firm’s rate of profit with a unique asymptotically stable random fixed point for a large class of productivity growth and dividend payout ratio processes. Based on an extensive numerical study of stationary solutions we show that the two consumption scenarios imply a limited number of diverse effects regarding equity and bond returns and equity premia.     

High‐pixel‐rate grating‐light‐valve laser projector

Abstract— A high‐pixel‐rate, high‐contrast (30,000:1) wide‐color‐gamut grating‐light‐valve laser projector is reported. A new optical engine enabling high‐frame‐rate (240 Hz) scan projection is employed. Panoramic wide‐angle‐scan projection with a 64:9 aspect ratio was also developed. Speckle noise is eliminated using a simple but highly efficient technique. The optical throughput efficiency of the grating‐light‐valve laser projector is reviewed.     

Slot-electrode optical modulator using KTiOPO(4)

A slot-electrode optical modulator is introduced and demonstrated with KTP at 532 nm. A switching voltage of 45 V, risetime of 3.5 ns, and power capability of more than 7 Ware measured. DC modulation without application of DC voltage is discussed. Further optimization can reduce the switching voltage to 18 V.     

-Structure of the respiratory system of the Ulodera Hynobius neblosus tokyoensis Tago, with special reference to the distribution of serotonin-immunoreactive cells in its respiratory tract epithelium

The respiratory tract epithelium in many vertebrate species has a neuroepithelial endocrine (NEE) system. This system is composed of solitary NEE cells or organoid cell groups called neuroepithelial bodies (NEBs). In response to chemical and physical stimuli, NEE cells may release bioactive substances. Serotonin, one of the biogenic amines, well-known as a constricter of smooth muscle, can be found in NEE cells, serotonin-immunoreactive cells can be used as a marker for these cells. Comparative histological studies of lower vertebrates can improve our understanding of mammalian respiratory systems. The Tokyo salamander (Hynobius neblosus tokyoensis Tago), classified as Ulodera, is particularly useful for comparative studies of respiration. In this study, the serial sections of respiratory tract of the Tokyo salamander were stained by a commonly used staining method and by an immunocytochemical method for serotonin, and the distribution of serotonin-immunoreactive cells in the respiratory tract was examined. The respiratory tract was found to be connected to the alimentary tract via an aditus laryngis, which opens on the medio-ventral side of the esophagus. The laryngotrachea was slit-like or elliptically shaped with a total length of about 3.5 mm, joining the aditus laryngis. The laryngotrachea was supported by a pair of lateral cartilages, and a fibromuscular layer was seen between the cartilages and the epithelium. In the cranial region, a laryngeal sphincter was seen around the laryngotrachea. The laryngotrachea branches into a pair of tube-like lungs, that are about 17-20 mm in length. Two apposed primary trabeclae run along the entire length of the lung wall, perpendicular to the axis, and containing the pulmonary arteries and veins. The lungs were divided into two portions: 1) an airway portion (trabeclae, septa) in which smooth muscles surrounding the large vessels were well developed, and 2) a respiratory portion which was give that name because it has well developed capillary networks that were assumed to be involved in gas exchange. The lumen of the laryngotrachea and the pulmonary airway portion contained pseudostratified cilio-mucous epithelium. In the caudaldorsal region of the laryngotrachea adjacent to the lungs, the non-ciliated respiratory epithelium was seen lining the capillaries. In cilio-mucous epithelium of the laryngotrachea, all serotonin-immunoreactive cells were solitary. They apposed to be columnar, cuboidal, triangular, oval, and flask- or spindle-shaped. Solitary serotonin-immunoreactive cells were classified "open type cell" with appical process reaching to the luminal surface and "closed type cell" insulated from the lumen by an epithelial lining. In the pulmonary airway portion, serotonin-immunoreactive cells were solitary cells and in clusters. Serotonin-immunoreactive cells were widely distributed throughout the respiratory tract, but they tended to be found mainly in the cranial portion. The density was highest in the area with the laryngeal sphincter, and decreased caudally in the laryngotrachea and lung. No serotonin-immunoreactive cells were found in the respiratory portion of the dorsal-caudal area of the laryngotrachea or in the part of the lung with non-ciliated cells. So the structure and distribution of serotonin-immunoreactive cells in the respiratory tract of the Tokyo salamander are similar to those of NEE cells and NEBs in mammalian respiratory systems. The density of serotonin-immunoreactive cells appears to be related to the distribution of smooth muscles in the fibromuscular layer and airway portion. The cells may be involved in regulation of the respiratory system. Serotonin is released in response to stimulation, which could result in constriction of the fibromuscular layer and shrinkage of the laryngotracheal cavity, and may regulate pulmonary volume by constricting smooth muscles     

Topological design considering flexibility under periodic loads

Topology optimization has been extensively considered to design the structural configuration for the stiffness maximization and the eigenfrequency maximization. In this paper, we construct a topology optimization method implementing flexibility with the time-periodic loading condition. First, the flexibility in the dynamic periodic loading is formulated using the mutual energy concept. Second, the multi-optimization problem is formulated using a new multi-objective function in order to obtain an optimal solution incorporating both flexibility and stiffness. Next, the topology optimization procedure is developed using the homogenization design method. Finally, some examples are provided to confirm the optimal design method presented here. Received January 18, 1999