Fractionation of ethylene–propylene copolymers

Ethylene–propylene (EP) copolymers were fractionated according to chemical composition, molecular weight, or monomer sequence length, which are fundamental distribution factors. Cloud points of polyethylene (PE), polypropylene (PP), and EP copolymer were determined prior to the fractionation. From the results, it was estimated that xylene–butyl cellosolve and tetralin–ethyl carbitol systems were suitable for the fractionations according to chemical composition and molecular weight, respectively. EP random-type copolymers were fractionated using a xylene–butyl cellosolve system. Separations according to chemical composition were obtained as expected. Then, the above polymer fractions were further fractionated in a tetralin–ethyl carbitol system. and the dependence on molecular weight was observed fairly well. Furthermore, fractionation according to monomer sequence length was satisfactorily achieved by solvent extraction using ethyl ether, n-hexane, cyclohexane, and n-heptane. Therefore, it is concluded that the more detailed characterizations of EP copolymers are made possible by a combination of these techniques.     

Tool life monitoring during the diamond turning of electroless Ni–P

Diamond tools become severely worn when machining Ni–P plating materials. Tool life monitoring is therefore essential to avoid the deterioration of workpiece quality. In this paper, in order to better detect tool life while the tools are in use, detailed investigations of the cutting force and acoustic emission (AE) measured during diamond turning process have been made. The results of this tool-life testing show that the cutting force and AE supply valuable information on tool failure; the dynamic component of the thrust force fluctuates chaotically when the tool dulls. This phenomenon can be detected using the 1/f^β power spectrum with a spectral exponent of β > 1. On the other hand, the AE amplitude a tends to rise just when chipping occurs on the cutting edge. This feature can be detected by the amplitude distribution spectrum, in which the AE event rate follows the power law a^−m with a scaling exponent of m < 2. Therefore, we can conclude that a spectral exponent of β > 1 and a scaling exponent of m < 2 can be used as the criteria to gauge tool life, because it was observed at the end of the tool life that tool corner had become worn out and that chipping had occurred on the cutting edge.     

A method of estimating energy saving effect and its application to factory energy supply systems

In order to carry out energy saving service, it is indispensable to calculate the energy saving effect quantitatively by presuming the energy cost at the time of not executing the energy saving measure. However, it is difficult because the energy cost changes when environment (energy demand, unit prices of fuel or electric power, and so on) changes even if an energy saving measure is not executed. Although the effect has been conventionally evaluated by the difference between the energy costs before and after the energy saving measure, the effect cannot be calculated correctly when there is environmental change. In this paper, we propose the method of estimating the energy saving effect by presuming the energy cost after an energy saving measure, assuming that the measure is not executed, and show the results of its application to the practical power plants. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(4): 14–20, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20880     

Study on flow and heat transfer of multiple impingement jets

Multiple jets are often used to obtain high heat transfer in a wide area. Heat and flow behavior of multiple jets show more complicated characteristics due to the existence of the interactions between adjoining jets, and between jets and spent flows. To clarify the influence of the flow behavior on heat transfer fields, the time and spatial heat transfer coefficients over the impingement plate were measured using an infrared radiometer when four jets impinged to the impingement plate for various jets arrangements and separating distances from jet exit to the impingement plate. The flow fields were also visualized by means of a water table. The heat transfer characteristics are made clear from the results of the instantaneous heat transfer contour or temperature fluctuation values. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(6): 419–431, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20073     

Proanthocyanidin‐rich grape seed extract reduces leg swelling in healthy women during prolonged sitting

BACKGROUND: Leg swelling is a modern‐day affliction of sedentary working women. The aim of this study was to evaluate the effectiveness of the intake of grape seed extract (GSE) on leg swelling in healthy Japanese women while sitting. RESULTS: Single intake trials and 14 day intake trials were held in a double‐blind, placebo‐controlled, crossover clinical study. A prolonged sedentary position was maintained for 6 h after GSE or placebo administration. Leg volume distension, increase in body extracellular fluid, and leg water were significantly suppressed in the GSE groups. CONCLUSION: The intake of GSE is a contributing factor in the inhibition of leg swelling in healthy women during prolonged sitting. © 2012 Society of Chemical Industry     

2,6‐Bis(amido)benzoic Acid with Internal Hydrogen Bond as Brønsted Acid Catalyst for Friedel–Crafts Reaction of Indoles

Benzoic acid catalysts bearing two amide groups that increase the Brønsted acidity of the carboxylic acid moiety by internal hydrogen‐bonding interactions were designed as a novel class of carboxylic acid catalysts for the Friedel–Crafts reaction of indoles with β‐nitrostyrenes and 3,3‐disubstituted 3H‐indoles to obtain the corresponding Friedel–Crafts adducts in high yields. The internal hydrogen‐bonding benzoic acid catalysts have a relatively high Brønsted acidity compared with benzoic acid based on the pK_a measurements in DMSO by UV spectrophotometric titration.