A study on the characteristics of glass fibre reinforced thermoplastics by transfer moulding

Lately, the use of fibre reinforced thermoplastics (FRTP) has increased due to its increased mouldability compared to thermosetting FRP material.

FRTP includes stampable sheet, short and long fibre reinforced thermoplastic pellets, continuous fibre reinforced thermoplastics sheets, etc. The long fibre reinforced thermoplastic (LFRTP) pellet has better mechanical properties than short fibre reinforced pellets and better mouldability than stampable sheet. At present, injection moulding method is mainly used for moulding LFRTP pellets because of its high productivity.

However, the long fibre of LFRTP pellets, whose length is the same as pellet length, is degraded during processing if conventional injection moulding machines are used, and as a result, the mechanical properties are not improved as expected in many cases. Therefore, a new moulding process is required to make good use of LFRTP pellets.

For this study, a transfer moulding apparatus was designed and built to minimize fibre degradation of the moulded parts.

Firstly, the LFRTP pellets with fibre lengths of 3, 6, 9, 12.7 and 17 mm were prepared in order to clarify the difference of mechanical properties due to fibre length. The fibre ratio was 30% in weight for all cases and the same polypropylene was used. They were moulded to the shape of the test specimens. Tensile, bending and Izod impact strengths were measured by using these test specimens. Secondly, LFRTP pellets were moulded to the shape of test specimens by the transfer moulding apparatus and conventional injection moulding machine, and then mechanical properties were measured. At the same time, short fibre pellets were moulded to the smae shape of test specimens by the injection moulding machine, and mechanical properties were compared with those of LFRTP pellets.

With the long glass fibre reinforced polypropylene, good results of fibre preservation and mechanical properties were obtained by the transfer moulding apparatus which was built for this study. The impact strength was increased remarkably as the fibre length increased, and consequently the preservation of fibre length in the moulded parts was especially effective in improving the impact strength.     

Improvement of inverse heat conduction solution using Laplace transformation: Method of partial division of time

Any solution for an inverse heat conduction problem makes the estimation of surface temperature and surface heat flux worsen in the case where these values behave like a triangular shape change with time. In order to compensate for this defect, Monde and colleagues, who succeeded in obtaining analytical inverse solutions using the Laplace transform technique, introduce a new idea where these changes over the entire measurement time can be split into several parts depending on the behavior. Therefore, an approximate equation to trace the measured temperature change can be derived, resulting in good estimation of surface temperature and surface heat flux even in the case of the triangular shape change and sharp change. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(7): 630–638, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10117     

Morphological estimation of total number of influenza A type virion spikes.

When purified and stored influenza A type virions were observed by the negative staining method in electron microscopy, we found disintegrated virions associated with a population of dispersed but clustered spikes. The total spike numbers of the clusters were morphologically counted, and their peak number (about 200) was consistent with the spike number measured by the molecular biology method, described in the other report.     

日本彩色聚乙烯涂覆钢管的开发

试验了彩色聚乙烯涂覆钢管的耐腐蚀性和耐气候性，由于聚乙烯涂层隔绝水的作用，聚乙烯涂覆钢管具有优良的耐腐蚀性能，电阻绝缘值和优良的机械性能。建立了一个新的方式去研究分析聚乙烯抗老化剂消耗和在聚乙烯中的扩散。用有效测定的方法定量地预测彩色聚乙烯涂覆层的寿命，应用这些分析结果，不仅可使新的有色聚乙烯涂覆钢管在恶劣腐蚀环境介质情况下具有高的耐腐蚀性，而且有长的耐气候性。     

Combinatorial Measurement of CDKN1A/p21 and KIF20A Expression for Discrimination of DNA Damage-Induced Clastogenicity

In vitro mammalian cytogenetic tests detect chromosomal aberrations and are used for testing the genotoxicity of compounds. This study aimed to identify a supportive genomic biomarker could minimize the risk of misjudgments and aid appropriate decision making in genotoxicity testing. Human lymphoblastoid TK6 cells were treated with each of six DNA damage-inducing genotoxins (clastogens) or two genotoxins that do not cause DNA damage. Cells were exposed to each compound for 4 h, and gene expression was comprehensively examined using Affymetrix U133A microarrays. Toxicogenomic analysis revealed characteristic alterations in the expression of genes included in cyclin-dependent kinase inhibitor 1A (CDKN1A/p21)-centered network. The majority of genes included in this network were upregulated on treatment with DNA damage-inducing clastogens. The network, however, also included kinesin family member 20A (KIF20A) downregulated by treatment with all the DNA damage-inducing clastogens. Downregulation of KIF20A expression was successfully confirmed using additional DNA damage-inducing clastogens. Our analysis also demonstrated that nucleic acid constituents falsely downregulated the expression of KIF20A, possibly via p16 activation, independently of the CDKN1A signaling pathway. Our results indicate the potential of KIF20A as a supportive biomarker for clastogenicity judgment and possible mechanisms involved in KIF20A downregulation in DNA damage and non-DNA damage signaling networks.     

Correlation for boiling heat transfer of R-134a in horizontal tubes including effect of tube diameter

A Chen-type correlation for flow boiling heat transfer of R-134a in horizontal tubes was modified taking into account the effect of tube diameter. The effect of tube diameter on flow boiling heat transfer coefficient was characterized by the Weber number in gas phase. Results showed that this correlation could be applied to a wide range of tube diameters (0.5–11-mm-ID). In addition, the dryout point and the heat transfer characteristics after the dryout point were also investigated based on the annular flow model. The proposed experimental expressions to predict both the dryout quality and the post-dryout heat transfer coefficient could also be applied to a wide range of tube diameter (0.5–11-mm-ID).     

Analytical approach with Laplace transform to the inverse problem of one‐dimensional heat conduction transfer: Application to second and third boundary conditions

An analytical method using Laplace transformation has been developed for one‐dimensional heat conduction. This method succeeded in explicitly deriving the analytical solution by which the surface temperature for the first kind of boundary condition can be well predicted. The analytical solutions for the surface temperature and heat flux are applied to the second and third of the boundary conditions. These solutions are also found to estimate the corresponding surface conditions with a high degree of accuracy when the surface conditions smoothly change. On the other hand, when these conditions erratically change such as the first derivative of temperature with time, the accuracy of the estimation becomes slightly less than that for a smooth condition. This trend in the estimation is similar irrespective of any kind of boundary condition. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(1): 29–41, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10069     

Determination of preservative and antimicrobial compounds in fish from Manila Bay, Philippines using ultra high performance liquid chromatography tandem mass spectrometry, and assessment of human dietary exposure

Ultra high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of four paraben preservatives (methyl, ethyl, propyl and butyl) and two antimicrobial agents (triclosan and triclocarban) belonging to personal care products (PCPs) in 20 species of fish from Manila Bay (Philippines) was performed. Detection of PCPs with greater frequency indicates the ubiquitous contamination of Manila Bay. Concentrations of total paraben were one order of magnitude higher than the antimicrobials in almost all fish, except in Stolephorus indicus and Leiognathus equulus. A positive correlation was observed between parabens concentration and fish length (r = 0.31-0.49; p<0.05 to <0.001) and fish weight (r = 0.28-0.49; p<0.05 to <0.001), but not for the antimicrobials. The estimated dietary exposure values of the four parabens in the Philippines through fish is four orders of magnitude lower than the acceptable daily intake (ADI) of 10mg/kg/day, but the values of antimicrobials are just half of the ADI of TCS. To our knowledge, this is the first report of PCPs contamination in fish from Philippines.     

Dynamical Transition of 4He Crystallization in a Very High Porosity Aerogel

Crystallization of ⁴He in aerogels of 90 and 96% porosities shows a dynamical phase transition at around 600 mK due to the competition between thermal fluctuation and disorder: crystals grow via creep at high temperatures and via avalanche at low temperatures. In a very high porosity 99.5% aerogel, however, the transition had not been observed in our previous publication (Nomura et al. in Phys. Rev. Lett. 101:175703, 2008). We improved the spatial resolution of the video image and found that the 99.5% aerogel did have the transition at around 200 mK, which is much lower than those of the lower porosities. The avalanche size is significantly smaller in the 99.5% aerogel. The reduction in the transition temperature and avalanche size may be the consequence of weaker disorder for the crystallization in the very high porosity aerogel.