Studies on heterogeneous degradation of polypropylene/talc composite: Effect of iron impurity on the degradation behavior

In this study, an effect of iron oxide (Fe₂O₃) impurity in talc on degradation behavior of polypropylene (PP)/talc composite was studied using a PP/Fe₂O₃ model composite sample. The thermal oxidative degradation was performed at 100°C. Although the degradation of a pure PP sample hardly occurred at such temperature, the existence of Fe₂O₃ induced the PP degradation. The degraded PP part was formed around the Fe₂O₃ grain in the PP/Fe₂O₃ sample. It was found from the optical microscope observation that the degraded PP was able to diffuse only within the PP amorphous part. The analysis of the oxidation distribution on the degraded PP surface was performed employing a scanning electron microscope/electron dispersive spectrometer. The result showed that the PP spots in the vicinity of the Fe₂O₃ grain were unoxidized during the initial degradation process, and the oxidized PP spots were located at around 6 μm distance from the Fe₂O₃ grain. It was concluded that the degradation was initiated microscopically away from the Fe₂O₃ grain so that the Fe₂O₃ had both the abilities to accelerate the decomposition of PP hydroperoxide compounds and to reduce the produced radical species into nonradical products. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Thermal stabilization of penicillolysin, a thermolabile 19 kDa Zn2+-protease, obtained by site-directed mutagenesis

Penicillolysin is a member of the clan MX and the family of M35 proteases. The enzyme is a thermolabile Zn(2+)- protease from Penicillium citrinum with a unique substrate profile. We expressed recombinant penicillolysin in Aspergillus oryzae and generated several site-directed mutants, R33E/E60R, A167E and T81P, with the intention of exploring thermal stabilization of this protein. We based our choice of mutations on the structures of homologous thermally stable enzymes, deuterolysin (EC 3.4.24.39) from A.oryzae and a peptidyl-Lys metallopeptidase (GfMEP) from the edible mushroom Grifora frondsa. The resulting mutant proteins exhibited comparable catalytic efficiency to the wild-type enzyme and some showed a higher tolerance to temperature.     

Experiment on and analysis of mobile content transformation using XSLT

Much attention is being paid to the services that are accessed via the Internet from mobile phones and PDAs. For such mobile Internet services, the WAP Forum issued the WAP 2.0 standard based on IETF/W3C standards. WAP 2.0 adopted the subset of eXtensible HyperText Markup Language (XHTML) and Cascading Style Sheets (CSS) standardized by World Wide Web Consortium (W3C), as its markup language. The i‐mode service in Japan was launched in February 1999, and has acquired over 40 million users, as of January 2004. The markup language adopted in the i‐mode service is called i‐mode HTML, and was designed around Compact HTML. To ease the migration from i‐mode HTML to the WAP 2.0 markup language, the functional compatibility of the languages should be assured. To this end, we proposed functions unique to i‐mode HTML to the WAP Forum. The WAP Forum accepted all of our proposals. For making the migration more cost‐effective, software tools that support the transformation of i‐mode HTML content to the WAP 2.0 equivalents must be established. There are two approaches to content transformation: software‐based and rule‐based. Since the software‐based approach has some drawbacks such as a lack of extensibility and a lack of accountability, we have taken the rule‐based approach. We focused on eXtensible Stylesheet Language Transformation (XSLT) as the content transformation technique, because XSLT has been standardized by W3C for rule‐based transformation between XML contents. To technically verify the applicability of XSLT for content transformation from i‐mode HTML to the WAP 2.0 markup language, we performed an extensive XSLT transformation experiment using existing i‐mode service contents. In this paper, we describe content transformation using XSLT, overview the content transformation system, and analyze the results of the content transformation experiment. Copyright © 2006 John Wiley & Sons, Ltd.     

Estrogen receptor binding assay method for endocrine disruptors using fluorescence polarization

A rapid, simple and nonhazardous assay method for endcrine disruptors was developed using an estrogen receptor (ER) and fluorescence polarization (FP). Among the fluorescent compounds, the 17alpha-fluorescein-labeled estradiol derivative was selected as the most suitable ligand for the ER binding assay, since it showed the highest affinity to ER. In the Scatchard plot analysis, its convex curve exhibited a positive cooperative binding, indicating the induction of a conformational change of the ER with the binding of the ligand to form a dimer and to increase the affinity for the additional ligand. On the basis of the Hill plot analysis, its dissociation constant and Hill coefficient were 10.4 nM and 1.63, respectively. A competitive binding assay with an unlabeled 17beta-estradiol (E2) yielded an IC50 value of 2.82 nM and a Hill coefficient of 1.67, thus providing a Ki value of 0.65 nM. In the same manner, the Hill coefficients for estrone, estriol, diethylstilbestrol, and tamoxifen were determined to be 0.99, 1.17, 1.59, and 2.44, respectively.     

Cognitive Bias in the Laboratory Security Market

The Efficient Market Hypothesis has been a kind of pivot both for academic research and for policy making concerning stock market for the last decades. But this hypothesis recently keeps being criticized both from archival and experimental viewpoints. In this paper we also criticized it based on psychological experiment. Concretely we show that the appearance of three kinds of cognitive bias has a possibility in real stock markets and we also demonstrate that even information efficiency is a kind of problem concerning human psychology. We conclude that government disclosure policy of stock market must take psychological aspect of investors into consideration.     

Development of a basic air-cooling fuzzy control system for hypothermia

Surface cooling by an automatic control system using a water blanket ensures a bloodless method of accurate brain hypothermia for cerebral protection at various stages of medical treatment. The control of temperature without any effects from the outside environment means that medical staff have less need to use their special skills for the exact management of brain temperature in clinical application, although the method is based on an easily handled surface water-cooling system. However, water is not always an appropriate medium for clinical cooling, from the viewpoint of both patients and the medical staff, because of the maintenance of the system in an intensive care unit (ICU). In order to cope with such difficulties, air-cooling is proposed based on various simulation results. Here, the aim is to realize automatic temperature control based on a fuzzy algorithm as a clinical reflection of the medical staff’s knowledge and experience. Experiments were carried out using a mannequin with human thermal characteristics in order to verify the utility of the basic automatic air-cooling control system for the treatment of brain hypothermia.     

Tensile Fracture Location Characterizations of Friction Stir Welded Joints of Different Aluminum Alloys

The tensile fracture location characterizations of the friction stir welded joints of the AA1050-H24 and AA6061-T6 Al alloys were evaluated in this study. The experimental results show that the fracture locations of the joints are different for the different Al alloys, and they are affected by the FSW parameters. When the joints are free of welding defects, the AA1050-H24 joints are fractured in the HAZ and TMAZ on the AS and the fracture parts undergo a large amount of plastic deformation, while the AA6061-T6 joints are fractured in the HAZ on the RS and the fracture surfaces are inclined a certain degree to the bottom surfaces of the joints. When some welding defects exist in the joints, the AA1050-H24 joints are fractured on the RS or AS, the AA6061-T6 joints are fractured on the RS, and all the fracture locations are near to the weld center. The fracture locations of the joints are dependent on the internal structures of the joints and can be explained by the microhardness profiles and defect morpho     

Field test of a novel combined system of a high-efficiency heating/cooling heat pump and a clathrate cool storage unit

The Research Laboratory of Kyushu Electric Power Co., Inc. (KEPCO) installed a novel system in March 1992 which is a combination of a super heat pump with about twice the performance of a conventional one and a compact chemical storage-type clathrate cool storage unit. A field test was implemented by integrating these units into an actual air-conditioning system. As a result of the test, system performance was determined and the effectiveness of the system was confirmed. © 1998 Scripta Technica. Heat Trans Jpn Res, 26(6): 410–418, 1997