Solubility of propylene in semicrystalline polypropylene

Gas solubilities and polymer swelling in propylene and semicrystalline polypropylene system at temperatures of 323.2 and 348.2 K and pressures up to propylene's vapor pressure were measured. Pressure, specific volume, and temperature (PVT) measurements of polypropylene were carried out at temperatures from 313 to 573 K and pressures up 200 MPa. Two kinds of polypropylenes, which had different stereoregularities, were used for both solubility and PVT measurements. The solubilities were correlated with the Sanchez–Lacombe equation of state (EOS) with temperature‐dependent binary interaction parameters to within 5% average relative percentage deviation. Swelling ratios estimated with Sanchez–Lacombe EOS coupled with optimized interaction parameters were 20% lower than the experimental values. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1134–1143, 2001     

Gelation of poly(vinyl alcohol)/water/dimethylformamide solutions and properties of dried films

The properties of solutions for syndiotacticity-rich poly(vinyl alcohol) (s-PVA)/dimethylformamide (DMF)/water systems, the gelation of the s-PVA solutions, and the properties of the dried s-PVA gel films were examined. From the results of the dissolution temperature of the polymer, the gelation temperature of the solutions, the melting temperature of the gels, and the compressive modulus of the gels, the solubility of the polymer was the highest at DMF contents of 10–20 vol %. The maximum dynamic tensile modulus of the drawn (×18) films obtained from the dried gel films with a DMF content of 10 vol % was 54.9 GPa at 20°C. The orientation of the polymer chains in the amorphous regions was higher than that in the crystalline regions. The orientation of the polymer chains in the amorphous regions for the drawn films with a DMF content of 10 vol % was higher than that for the drawn films with a DMF content of 60 vol %. The orientation of the polymer chains in the amorphous regions was considered to play an important role in the properties of high strength and high modulus. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1661–1667, 1998     

Measurement of electric intensity distribution inside human cadaver cochlea for multichannel cochlear implants

We have proposed a Tripolar Electrode Stimulation Method (TESM) which may succeed in narrowing the stimulation region and continuously moving the stimulation site for cochlear implants. The TESM stimulates the auditory nerve array through lymphatic fluid by means of three adjacent electrodes selected from among an electrode array. Currents are emitted from the electrodes on each side and the central electrode receives them. The current received by the latter electrode is equal to the sum of the currents emitted from the electrodes on the two sides. In this paper, the electric intensity profiles produced by the TESM and by monopolar stimulation were measured in a human cadaver cochlea and in a saline solution. We found that in the TESM, the electric intensity profile produced in the human cadaver cochlea was about the same as that in the saline solution. In addition, in the TESM, the electric intensity profile was much sharper than that of monopolar stimulation in the human cadaver cochlea. Furthermore, the nervous excitation region could be localized in a certain range by means of TESM. © 1999 Scripta Technica, Electr Eng Jpn, 129(1): 1–9, 1999     

Color gamut mapping based on a perceptual image difference measure

Gamut mapping is a color transformation technique to solve a problem caused by mismatch of gamuts among imaging devices. One plausible goal of gamut mapping is to find a reproduction that is perceptually closest to the corresponding original image when an exact color matching is not possible. Several measures to quantify the perceptual difference between images have been proposed and applied to the gamut mapping problem. However most of the measures, such as average color difference, are applied on a pixel‐wise basis and show poor correlation with human visual perception. This article describes a model of the perceptual image difference for a given pair of images, which takes the human's contrast sensitivity into account and applies the model to a gamut mapping for generating a reproduction with minimum perceptual image difference. The model has a multispatial‐frequency channel structure with tunable peak gains for each channel, which are determined by psychophysical experiments, so that the model output fits the observer's sensitivity to the image difference. A gamut‐mapped image with minimum perceptual image difference is obtained by an iterative minimization process. To evaluate the proposed method, subjective evaluation experiments are performed to construct ratio scales that measure perceptual image difference of gamut‐mapped reproductions generated by the proposed and pixel‐wise methods. Results show that the reproductions by the proposed method are perceived as perceptually closest to the original, and the model's estimate of perceptual difference correlates better with the experimentally measured perceived image difference than other pixel‐wise measures. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 280–291, 1999     

Video Scene Annotation Based on Web Social Activities

This article describes a mechanism to acquire the semantics of video content from the activities of Web communities that use a bulletin-board system and weblog tools to discuss video scenes.     

A superconducting filter to separate an oxygen and argon mixture

Hot isostatic pressing in an oxygen atmosphere, known as O₂-HIP method, has been used successfully to synthesize oxide materials, as well as to produce porous materials. In this paper a porous superconducting oxide is synthesized by this method and its application as a gas filter is described. Porous superconductors can be used to separate a mixture of paramagnetic and diamagnetic gases, such as oxygen and argon. Separation occurs after a magnetic field is applied and is based on the Meissner effect. Experimental results showed that the oxygen content of an oxygen/argon mixture increased after passing through a filter with large pore size (about 10 m).     

Transgenesis by adenovirus-mediated gene transfer into mouse zona-free eggs

Zona-free mouse eggs at the pronucleus stage were infected with a replication-defective adenovirus vector containing a nuclear-targeted lacZ gene. Exogenous beta-galactosidase activity was detected in almost all eggs at the two-cell stage. Of 27 mice that developed from infected eggs, three carried the integrated exogenous gene mediated by the adenovirus. Two of the three expressed the lacZ gene, and all three mice transmitted the adenovirus-mediated transgene to F1 progeny Southern blot analysis was consistent with single copy integration. This finding should accelerate the development of new strategies for transgenesis and assist studies on the function of cloned genes in vivo.     

Atmospheric polychlorinated naphthalenes in Ghana

A nationwide monitoring of atmospheric POPs (persistent organic pollutants) was conducted in Ghana between May and July 2010, applying polyurethane foam (PUF) disk passive air samplers (PAS). Reported here are preliminary findings on PCNs, an industrial organic contaminant currently under review for possible listing under the global chemical treaty. The present results constitute the first set of nationwide data on air PCNs from a West African country. Contrary to expectation, air PCNs levels were quite high in Ghana, at an average of 49 ± 5.4 pg/m(3). The coastal (southern) zone of Ghana appeared the most impacted, with crude open burning of waste, industrial emissions, and the harbor environment identified among possible emission factors. Tri- and tetra-CNs (the lowly chlorinated homologues) predominated in the atmosphere, altogether constituting approximately 90% of total PCN homologues composition. Increased volatilization under tropical conditions was presumed a key factor that contributed to this high atmospheric input of lowly chlorinated homologues. We further observed a significant level of fractionation of PCN homologues across the breadth of the country. The percentage composition of the lowly chlorinated homologues increased northwards, probably because of their transportation in the direction of prevailing winds. From congener profile analysis, PCN-45/36 is proposed as a possible source marker for emissions preempted by uncontrolled waste burning activities. Dioxin-like toxicity of air PCNs in Ghana was estimated to range 0.49-5.6 fg TEQ/m(3). This study brought to the fore the emerging problems of nonagricultural organohalogens that covertly might be confronting the environment in African nations like Ghana.     

IIPP: integrated IP paging protocol with a power save mechanism

The advent of advanced mobile/wireless systems has been facilitating the battery‐powered mobile computing devices (nodes) to remain always connected to the internet. However, until now, the power‐drain rate of mobile nodes is very high in comparison with the available power of portable batteries. To reduce the energy consumption of mobile nodes, we present an integrated IP paging protocol (IIPP) by integrating the IP‐layer paging protocol based on Mobile IPv4 regional registration (MIPRR) with a power save mechanism. IIPP reduces the frequency of signaling messages between mobile nodes and networks. When not sending or receiving data for a certain time, mobile nodes enter power save mode (PSM), and consume very low power. We formulate analytical models and carry out simulations to evaluate the proposed IIPP. The results show that, compared to MIPRR, IIPP significantly reduces the average power consumption of the mobile node and signaling overheads in the network. Copyright © 2006 John Wiley & Sons, Ltd.