Polyether-segmented nylon hemodialysis membranes. II. Morphologies and permeability characteristics of polyether-segmented nylon 610 membrane prepared by the phase inversion method

The relationships between the morphologies and the permeability characteristics as dialysis membrane of polyether-segmented nylon 610 (PE-Ny610) have been investigated. PE-Ny610 used are poly(propylene oxide) (PPO)-segmented nylon 610 containing 25 wt % PPO (PPO-Ny610) and poly(ethylene oxide) (PEO)-segmented nylon 610 containing 15 wt % PEO (PEO-Ny610). The morphologies in the cross section of the membranes exhibit the cellular porous structures due to liquid-liquid phase separation. On the other hand, the structures of the surfaces are mainly composed of the crystalline spherulite due to liquid-solid phase separation. These morphologies are little affected by the composition ratio of the coagulant, calcium chloride/methanol/water mixture. PEO-Ny610 membranes have shown superior membrane performances to the PPO-Ny610 membrane. The effect of PEO content in PEO-Ny610 on the adhesion of platelet onto the PEO-Ny610 film surface was investigated and it is concluded that PEO-Ny610 having > 10 wt % PEO shows a good nonthrombogenicity equal to PPO-Ny610. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1713–1721, 1997     

Observation of lightning at 500‐kV transmission lines (part 1)

We investigated the phenomenon of lightning strokes on 500‐kV transmission lines from 1984 to 1993. The investigation covered the recording of lightning paths by still cameras and measurements of lightning current at the lower part of transmission tower on 31 towers, over a 12.7‐km‐long section of the transmission line. We also observed lightning on an isolated tower at a nuclear power station. In the course of lightning observations spanning a 10‐year period, we have confirmed the suitability of the lightning protection design on transmission lines. The distribution of lightning incidence angle (θ) expressed in terms of (cos^mθ) was characterized by exponent m = 2 for the three‐dimensional observations and m = 3.5 for the two‐dimensional observations. No cases of shielding failure on 500‐kV transmission lines were observed. The ratio of lightning current at the top of the isolated tower to the lower part was about 11 to 1. In addition, the lightning current waveform at the top of the isolated tower was similar to that at the lower part. © 1999 Scripta Technica, Electr Eng Jpn, 130(2): 59–67, 2000     

High‐performance speed control based on an instantaneous speed observer considering the characteristics of a dc chopper in a low speed range

This paper proposes a new high‐performance speed control method for wide speed range, which is based on instantaneous speed observer considering the characteristics of dc chopper. In order to regulate a motor speed for wide speed reference including a very low speed range, this paper designs the instantaneous speed observer which uses the information of an armature current and an armature voltage. This observer has no effect of inertia variation and disturbance torque completely, but it has the effect of electrical parameter variation. Hence, this paper proposes a new identification algorithm to cancel out the estimation error caused by both the resistance variation and the voltage drop. The proposed observer can always estimate an instantaneous value of motor speed. The proposed total system becomes a new robust speed servo system for a wide speed range. © 1999 Scripta Technica, Electr Eng Jpn, 130(3): 77–87, 2000     

Current dependence measurement of 1 Ω standard resistorsusing a cryogenic current source with linear output

We have developed a cryogenic current source with linear output up to 1 A, by combining a 1 mA current source with a cryogenic current comparator operating as a current amplifier. This source was used, along with a 1 V Josephson potentiometer, to determine the current dependence of two types of 1 Ω resistors     

A 650-GHz Band SIS Receiver for Balloon-Borne Limb-Emission Sounder

A superconducting low-noise receiver has been developed for atmospheric observations in the 650-GHz band. A waveguide-type tunerless mixer mount was designed based on one for the 200-GHz band. Two niobium SIS (superconductor-insulator-superconductor) junctions were connected by a tuning inductance to cancel the junction capacitance. We designed the ωR_nC_j product to be 8 and the current density to be 5.5 kA/cm². The measured receiver noise temperature in DSB was 126-259 K in the frequency range of 618-660 GHz at an IF of 5.2 GHz, and that in the IF band (5-7 GHz) was 126-167 K at 621 GHz. Direct detection measurements using a Fourier transform spectrometer (FTS) showed the frequency response of the SIS mixer to be in the range of about 500-700 GHz. The fractional bandwidth was about 14%. The SIS receiver will be installed in a balloon-borne limb-emission sounder that will be launched from Sanriku Balloon Center in Japan.     

Gallium-cooled liquid metallic-fueled fast reactor

We have examined the effects on core characteristics of using two different types of Pu-based metallic alloy fuels in the gallium-cooled fast reactor core. In the proposed concept, the liquid metal fast nuclear reactor uses metallic fuel in the liquid phase and gallium coolant at high temperature (inlet 1700K, outlet 1900K). The liquid fuel is continuously supplied to the reactor during operation at full reactor power. The reactor power is controlled by rotational control drums with absorber material. The aim was to evaluate reactor core neutronics and safety characteristics demonstrating a feasibility of the reactor system. Although gallium has large absorption cross section in the high neutron energy region, we can design the core with rather good neutronics performances. The large negative reactivity feedback induced by the thermal expansion of liquid metallic fuel ensures the core's inherent safety against the unprotected loss-of-flow transient.     

Evaluation of biological activities of a groundnut (Apios americana Medik) extract containing a novel isoflavone

Groundnut (Apios americana Medik) contains a novel isoflavone, genistein-7-O-gentiobioside. In the present study, we examined the biological activities of an alcohol extract of groundnut containing genistein-7-O-gentiobioside as the main component. Although the groundnut extract by itself did not show antioxidative activity, it drove the antioxidative system in cells. Pretreatment of human breast carcinoma MCF-7 cells for 24 h with the groundnut extract and soybean isoflavone increased gene expression of heme oxygenase-1 (HO-1), a major antioxidative stress enzyme. These groundnut extract-treated cells showed antioxidative activity against free radicals derived from a radical initiator. Pretreatment of cells with 100 μg/mL groundnut extract prevented the depletion of glutathione by the radical initiator; however, treatment with 100 μg/mL of soybean isoflavone injured the cell membrane, indicating that glutathione might be released to the extracellular environment. These results suggest that the groundnut extract had isoflavone-like activity. Like soybean, groundnuts are a good source of isoflavones.     

Monitoring the lactic acid bacterial diversity during shochu fermentation by PCR-denaturing gradient gel electrophoresis

The presence of lactic acid bacteria (LAB) during shochu fermentation was monitored by PCR-denaturing gradient gel electrophoresis (DGGE) and by bacteriological culturing. No LAB were detected from fermented mashes by PCR-DGGE using a universal bacterial PCR primer set. However, PCR-DGGE using a new primer specific for the 16S rDNA of Lactococcus, Streptococcus, Tetragenococcus, Enterococcus, and Vagococcus and two primers specific for the 16S rDNA of Lactobacillus, Pediococcus, Leuconostoc, and Weissella revealed that Enterococcus faecium, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus nagelii, Lactobacillus plantarum, Lactococcus lactis, Leuconostoc citreum, Leuconostoc mesenteroides, and Weissella cibaria inhabited in shochu mashes. It was also found that the LAB community composition during shochu fermentation changed after the main ingredient and water were added during the fermentation process. Therefore, we confirmed that PCR-DGGE using all three primers specific for groups of LAB together was well suited to the study of the LAB diversity in shochu mashes. The results of DGGE profiles were similar to the results of bacteriological culturing. In conclusion, LAB are present during shochu fermentation but not dominant.     

Fermented foods in a global age: East meets West

Fermented foods and alcoholic beverages have long been an important part of the human diet in nearly every culture on every continent. These foods are often well‐preserved and serve as stable and significant sources of proteins, vitamins, minerals, and other nutrients. Despite these common features, however, many differences exist with respect to substrates and products and the types of microbes involved in the manufacture of fermented foods and beverages produced globally. In this review, we describe these differences and consider the influence of geography and industrialization on fermented foods manufacture. Whereas fermented foods produced in Europe, North America, Australia, and New Zealand usually depend on defined starter cultures, those made in Asia and Africa often rely on spontaneous fermentation. Likewise, in developing countries, fermented foods are not often commercially produced on an industrial scale. Although many fermented products rely on autochthonous microbes present in the raw material, for other products, the introduction of starter culture technology has led to greater consistency, safety, and quality. The diversity and function of microbes present in a wide range of fermented foods can now be examined in detail using molecular and other omic approaches. The nutritional value of fermented foods is now well‐appreciated, especially in resource‐poor regions where yoghurt and other fermented foods can improve public health and provide opportunities for economic development. Manufacturers of fermented foods, whether small or large, should follow Good Manufacturing Practices and have sustainable development goals. Ultimately, preferences for fermented foods and beverages depend on dietary habits of consumers, as well as regional agricultural conditions and availability of resources.     

Rapid Determination of Iodine Value and Saponification Value of Fish Oils by Near-Infrared Spectroscopy

ABSTRACT: A rapid method for determining the iodine value (IV) and saponification value (SV) offish oils has been developed using near-infrared (NIR) spectroscopy. The partial least squares (PLS) calibration model was made based on a spectral range between 7560 and 9100 cm⁻¹ due to CH bond. The method was validated by comparing the IV and SV of a series of fish oils predicted by the PLS model to the values obtained by the titration methods of the Japan Oil Chemists' Society. The NIR-predicted IV and SV were completely consistent with chemically determined IV and SV. The NIR method showed higher accuracy and reproducibility than the titration method. It would be suitable for IV and SV determinations offish oils, as well as vegetable oils, and it takes only 2 min per sample.