Experience with IEC 1109 1000 h salt fog ageing test for compositeinsulators

This paper covers some examples of the STRI and NGK experience with the standard IEC 1109 salt fog test and some modifications of this test for different types of test objects     

FFTA: A fast fault tree analysis program

This paper presents a computer program for fault tree analysis. The algorithm is a bottom-up algorithm and the detailed procedure of the program is explained. The analyses are performed for six sample fault trees and the results are compared with those obtained by the BAM and CUT codes. This program has a ten to thousand times faster calculation speed compared with the BAM and CUT codes.     

Determination of Deep Frying Soybean Oil Disposal Point by a Sensory Method

Measurements of degradation in frying oils are mainly based on physico-chemical properties. Total polar compounds (TPC) and free fatty acids (FFA) content in frying oils are used as a guide for discarding used oils. The purpose of this study was to evaluate the efficacy of a sensory method in detecting degradation in soybean oils used in potato chips deep frying. The sensory evaluation of oil samples was determined by a trained panel; after rigorous selection and training steps. Free fatty acid, TPC and Rancimat induction period (IP) were quantified in the same samples. The proposed sensory method was sensitive to small differences in rancidity. The selected and trained sensory panel discarded oil samples with 0.175% FFA as oleic acid, 18.92% TPC, and 0.20 h IP. According to the results achieved in this research sensorial trained panel response is sensitive and accurate in refusing deteriorated frying oils. Besides this, soybean oil can be used for deep frying procedures and safely discarded according to the panel response, although presenting up to 7% linolenic acid.     

In-situ Raman Spectroscopic Investigation of the Effect of Cooling Speed on Domain Formation in PbTiO3 Films

The influence of the post-deposition cooling speed on the domain formation process of PbTiO₃ films was investigated using MOCVD equipment combined with in-situ Raman spectroscopy. The accumulation and relaxation of strain during the post-deposition cooling process is responsible for the domain structure. The Curie temperature for fast cooling is lower than that for slow cooling. Additionally, the residual strain with fast cooling is smaller than that with slow cooling. These observations suggest that the volume fraction of the c-domain is larger for fast cooling and that the atmospheric conditions during the first post-deposition cooling process may control the domain structure.     

Production and properties of phytase and acid phosphatase from a sake koji mold, Aspergillus oryzae

We identified three types of acid phosphatase (ACP-I, ACP-II, and ACP-III) produced by Aspergillus oryzae in a submerged culture using only phytic acid as the phosphorous substrate. The optimum pH for the activities of the three enzymes was in the range of 4.5 to 5.5. Analysis of the substrate specificities of these enzymes revealed that ACP-I and ACP-III were acid phosphatases, and ACP-II was a phytase. These enzymes were produced during different periods of mycelial growth: ACP-II was produced during the early phase of cultivation (around 24 h), and ACP-I was produced between 24 to 72 h. ACP-III was detected after the production of ACP-I and ACP-II had ceased. The release of phosphate from phytic acid was expected to be due to the cooperative hydrolysis of these enzymes.     

Characterization of polycyclic aromatic hydrocarbons (PAHs) in different size fractions in deposited road particles (DRPs) from Lake Biwa area, Japan

Deposited road particles (DRPs) collected from 13 heavily traveled roadways in an urban area of Southern Lake Biwa, Japan, were analyzed for polycyclic aromatic hydrocarbons (PAHs) in seven different particle size fractions (< or = 20 to 1000-2000 microm) and evaluated for the aryl hydrocarbon receptor (AhR) ligand activity by using a yeast bioassay. The mean compositions of individual PAHs to total PAH concentrations in different particle size fractions were 19-21% for pyrene, which was the most dominant component, 14-16% for fluoranthene, and 7-13% for benzo[g,h,i]perylene, which were the next dominant components. The total PAH distribution pattern in different particle size fractions of DRPs was different from the organic matter distribution pattern which increased with decreasing particle size of DRPs, and could be explained by the differences in their sources. Moreover, AhR ligand activities were observed in the DRP extracts of all size fractions. The activity of the DRP extracts from the smallest size fraction was approximately 5 times more potent than that of the largest size fraction in a yeast AhR ligand activity assay. The mean contribution (%) of benzo[k]-fluoranthene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene to the AhR activity of DRP extracts in all size fractions was 1.43-4.11%, 1.63-3.53%, 0.63-1.69%, and 0.31-1.42%, respectively. Although the contribution of PAHs to AhR ligand activity presented in the DRP extracts was relatively low (below 10%), it may be best to remove these DRPs before discharge to receiving water environments.     

Isolation and identification of xenobiotic aryl hydrocarbon receptor ligands in dyeing wastewater

Dyeing wastewater collected in Kyoto city, Japan, was investigated for the occurrence of aryl hydrocarbon receptor (AhR) ligands by using an AhR-responsive reporter gene assay. Concentrated extracts of wastewater samples elicited a dose-dependent increase in AhR ligand activity, and several hydrophobic HPLC fractions of the extracts were highly effective in inducing AhR ligand activity. Three potential AhR ligands were isolated from these fractions and identified to be Disperse Red 92, Disperse Yellow 64, and 3'-hydroxybenzo[b]quinophthalone by using HPLC and LC-MS/MS. Disperse Red 92, which has also been detected in the treated effluent from a sewage plant receiving the wastewater, is an anthraquinone disperse dye showing weak AhR binding affinity in the assay. Disperse Yellow 64 and 3'-hydroxybenzo[b]quinophthalone are quinoline disperse dyes capable of activating the AhR at nanomolar concentrations. In particular, Disperse Yellow 64 is a highly potent AhR ligand that was 3 times more effective in inducing AhR ligand activity than beta-naphthoflavone in the assay. Quinoline disperse dyes are suggested to be a new class of xenobiotic AhR ligands which pose a danger to aquatic biota and human health.     

Entropy,Free Volume,and Cooperative Relaxation

The high frequency end of the relaxation spectrum for polymer molecules involves the rotation of the segmental bonds. This fast relaxation process, however, cannot take place easily in the condensed state crowded by the densely packed conformers, necessitating the slower cooperatively synchronous relaxation. As the temperature is lowered, the domain of cooperativity grows towards the infinite size at the Kauzmann zero entropy temperature, though actually the system deviates from the equilibrium as the glass transition intervenes typically at 50 K above that temperature. The excess enthalpy and entropy drop faster than predicted by the rotational isomeric states which would reach zero only at 0 K. The real ΔC_P is greater than that of the RIS value. The actual volume in excess of the crystalline lattice volume, however, points towards zero at 0 K. Thus, a polymer with higher T_g typically exhibits a lower density and modulus in the glassy state. Since the configurational entropy associated with the free volume is proportional to the logarithm of the latter, the Kauzmann temperature can be scaled by ln M, where M is the algebraic average of the conformer molecular weight. The temperature dependence of the most dominant, i.e., the largest equilibrium domain size will result in the Adam-Gibbs and Vogel equations for the characteristic relaxation time. The cooperative domain distribution leads to the relaxation spectrum that follows a power law. The relationship between the characteristic relaxation time and the rate of physical aging is derived.