cis-Vaccenic acid in pulp lipids of commonly available fruits

Fatty acids of commonly available fruit pulps have been analyzed by capillary gas chromatography of their methyl esters and by gas chromatography-mass spectrometry as their dimethyl disulfide adducts. The gas chromatographic and mass spectrometric data proved that these fruits always containedcis-vaccenic (cis-11-octadecenoic) acid as a component fatty acid of their pulp lipids. The concentration ofcis-vaccenic acid in total octadecenoic acids ranged from 1.9% to 95.1% in the fruit pulps examined. The highest concentration of this acid was detected in pulp lipids of Japanese persimmon (Diospyros kaki). In fruit pulp lipids,cis-vaccenic acid was a common octadecenoic acid as well as oleic acid.     

Selective separation of water from water–ethanol solution through quarternized poly(4-vinylpyridine-co-acrylonitrile) membranes by pervaporation technique

Polymer membranes having cationic charge site, poly(1-alkyl-4-vinylpyridinium iodide-co-acrylonitrile) (alkyl: methyl, butyl, or octyl) were prepared in terms of coulombic interaction for separation of water–ethanol mixtures. The incorporation of cationic charge site into the membrane led to improve not only separation factors (selectivity toward water) but also flux number in the separation of aqueous ethanol solution by pervaporation technique. Target values, which were requested to have from the viewpoint of industrial utilization for separation of aqueous ethanol solution were attained as follows: separation factor toward water over 50 and flux value over 500 g m^?2 h^?1, through poly(1-methyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 3 ) (quarternized fraction of pyridinium moiety, 89.5%; mol fraction of pyridinium moiety, 0.034) and poly(1-butyl-4-vinylpyridinium iodide-co-acrylonitrile) (membrane 5 ) (quarternized fraction, 100%; mol fraction of pyridinium moiety, 0.038). It was found that the introduction of cationic charge site into the membrane was one of feasible methods to obtain suitable membranes for water permselective membranes in the separation of water–ethanol mixtures.     

A polymer complex as a new type of electron beam resist for dry development

Polymer complex of poly (4-vinylpyrldine) and malonic acid was investigated as a new type of electron beam (EB) resist for dry development, as malonic acid was decomposed by EB irradiation. It was found that the polymer complex could be developed with O₂ plasma etching and that the positive resist patterns with high resolution could be obtained. The mechanism for this lithography process was studied by means of IR and ESCA spectra.     

Influence of physical properties of activated carbons on characteristics of electric double-layer capacitors

Electrochemical characterization has been carried out for several activated carbons used as polarizable electrodes of electric double-layer capacitors in an aqueous electrolytic solution. The rest potential of the activated carbon was proportional to the logarithm of the oxygen content or to the concentration of the acidic surface functional groups of the activated carbon. The result of triangular voltage-sweep cyclic voltammetry was the same as that of the residual current measurement. The oxygen content and concentration of the acidic surface groups of activated carbon influenced the electrochemical characteristics of the activated carbon. Under anodic polarization, gas evolution was observed at the electrode surface of activated carbon with high oxygen content at 0.8 V versus saturated calomel electrode ( SCE). Gas evolution was not observed at the electrode surface of activated carbon with low oxygen content even to 1.0 V versus SCE. Under cathodic polarization of activated carbon with high oxygen content, the peak was observed at approximately −0.2 V versus SCE, but there was no gas evolution at the electrode surface of the activated carbon. Bubbles were not observed at the electrode surface of activated carbon with low oxygen content at −0.5 V versus SCE. Electric double-layer capacitors were made from activated carbons used for electrochemical measurements; load-life tests have been carried out. Thickness and internal resistance of the capacitor composed of activated carbon with high oxygen content increased. The changes in thickness and internal resistance of the capacitor composed of activated carbon with low oxygen content were small.     

Synthesis of high molecular weight poly(dialkyl fumarate)s bearing n-alkyl side chains from poly(di-tert-butyl fumarate) via olefin elimination and reesterification in a one-pot

Summary High molecular weight poly(dialkyl fumarate)s bearing n-alkyl esters such as an octadecyl group were prepared efficiently from poly(di-tert-butyl fumarate) by the one-pot synthesis, i.e. both elimination of isobutene from the tert-butyl ester and the subsequent esterification were performed in a corresponding alcohol at 170–180°C in a one-pot without isolating poly(fumaric acid). The resulting polymers were characterized by IR and NMR spectroscopies and GPC. The polymers with various contents of an octadecyl group in the side chain were also obtained similarly from the copolymer of di-tert-butyl fumarate with diisopropyl fumarate.     

Comparison between numerical simulation and visualization experiment on water behavior in single straight flow channel polymer electrolyte fuel cells

A relationship between a flooding and a cell voltage drop for polymer electrolyte fuel cell was investigated experimentally and numerically. A visualization cell, which has single straight gas flow channel (GFC) and observation window, was fabricated to visualize the flooding in GFC. We ran the cell with changing operation condition, and measured the time evolution of cell voltage and took the images of cathode GFC. Considering the operation condition, we executed a developed numerical simulation, which is based on multiphase mixture model with a formulation on water transport through the surface of polymer electrolyte membrane and the interface of gas diffusion layer/GFC. As a result in experiment, we found that the cell voltage decreased with time and this decrease was accelerated by larger current and smaller air flow rate. Our simulation succeeded to demonstrate this trend of cell voltage. In experiment, we also found that the water flushing in GFC caused an immediate voltage change, resulting in voltage recovery or electricity generation stop. Although our simulation could not replicate this immediate voltage change, the supersaturated area obtained by our simulation well corresponded to fogging area appeared on the window surface in the GFC.     

Aerial firefighting against urban fire: Mock-up house experiments of fire suppression by helicopters

The Great Hanshin Earthquake in 1995 claimed approximately 6400 lives. The majority was killed in large fires after the earthquake. Roads were cut off and collapsed buildings blocked the access of fire engines to fire fields. Water mains were broken and lack of water prevented firefighting efforts. If aerial firefighting had been effectively applied, many lives could have been saved.     

Cavitation damage prediction for spallation target vessels by assessment of acoustic vibration

Liquid-mercury target systems for MW-class spallation neutron sources are being developed around the world. Proton beams are used to induce the spallation reaction. At the moment the proton beam hits the target, pressure waves are generated in the mercury because of the abrupt heat deposition. The pressure waves interact with the target vessel leading to negative pressure that may cause cavitation along the vessel wall. In order to estimate the cavitation erosion, i.e. the pitting damage formed by the collapse of cavitation bubbles, off-beam tests were performed by using an electric magnetic impact testing machine (MIMTM), which can impose equivalent pressure pulses in mercury. The damage potential was defined based on the relationship between the pitting damage and the time-integrated acoustic vibration induced by impact due to the bubble collapses. Additionally, the damage potential was measured in on-beam tests carried out by using the proton beam at WNR (Weapons Neutron Research) facility in Los Alamos Neutron Science Center (LANSCE). In this paper, the concept of the damage potential, the relationship between the pitting damage formation and the damage potential both in off-beam and on-beam tests is shown.     

Batch-adaptive ship's autopilots*

Sea conditionsand ship's motions might be considered as a locally stationary process. This paper proposes an on-line fitting procedure using the AIC to such a process and applies it to design two kinds of batch-adaptive autopilot systems. In the first one, the ship's manoeuvring motion including yawing, rolling and rudder motions are modelled by using a MARX model and at the end of every batch period, an on-line judgement for the following period is carried out by applying the minimum AIC procedure and the best MARX model to represent the present states of the manoeuvring motion. The second autopilot is an extension of the adaptation rule to a noise-adaptive autopilot system. Copyright © 2000 John Wiley & Sons, Ltd.     

Configuring a Network Management System for Efficient Operation

Configuring a network management system involves the delicate art of balancing the requirements of the management system with the available network resources.