Structural behaviour of a welded superalloy cylinder with internal pressure in a high temperature environment

Steady and cyclic creep tests with internal pressure were performed at temperatures of 800 to 1000°C on Hastelloy X cylinders with and without a circumferential Tungsten Inert Gas (TIG) welding technique. The creep rupture strength of the TIG welded cylinders was much lower than that of the non-welded cylinders whilst creep rupture strength reduction by the TIG technique was not observed in uniaxial creep tests. The reason for the low creep strength of welded cylinders is discussed and it is noted that the creep ductility of weld metal plays an essentially important role.In order to improve the creep strength of the TIG welded cylinder, various welding procedures with assorted weld metals were investigated. Some improvements were obtained by using welding techniques which had either Incoloy 800 or a modified Hastelloy X material as the filler metal.     

Quantitative source identification of dioxin-like PCBs in Yokohama, Japan, by temperature dependence of their atmospheric concentrations

The source and environmental behavior of dioxin-like polychlorinated biphenyls (PCBs) together with other PCBs and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs) were evaluated based on analysis of variations in their atmospheric concentrations in Yokohama, Japan. Potential factors responsible for variations in the atmospheric concentrations of the congeners were investigated by principal component analysis and multiple regression analysis of the data. Two major variations were seen: one had strong temperature dependence, while the other had no significant temperature dependence. A possible explanation for this difference is that the former is related to congeners released by volatilization (e.g., volatilization from commercial PCB products and past polluted environments), while the latter is related to congeners emitted from thermal processes. The relative contributions of dioxin-like PCBs released by volatilization and those emitted from thermal processes were estimated based on the temperature dependence of the atmospheric concentrations. The results suggest that both dioxin-like PCBs emitted from thermal processes and those released by volatilization are significant sources of air pollution in this area in terms of the toxic equivalent (TEQ) for dioxin-like PCBs. We demonstrated that the present approach based on variations in atmospheric concentrations can be useful in providing a qualitative as well as quantitative understanding of source information.     

Simple and comprehensive two-dimensional reversed-phase HPLC using monolithic silica columns

Simple and comprehensive two-dimensional (2D)-HPLC was studied in a reversed-phase mode using monolithic silica columns for second-dimension (2nd-D) separation. Every fraction from the first column, 15 cm long (4.6-mm i.d.), packed with fluoroalkylsilyl-bonded (FR) silica particles, was subjected to the separation in the 2nd-D using one or two octadecylsilylated (C(18)) monolithic silica columns (4.6-mm i.d., 3 cm). Monolithic silica columns in the 2nd-D were eluted at a flow rate of up to 10 mL/min with separation time of 30 s that meets the fractionation every 15-30 s at the first dimension (1st-D) operated at a flow rate of 0.4-0.8 mL/min. Three cases were studied. (1) In the simplest scheme of 2D-HPLC, effluent of the 1st-D was directly loaded into an injector loop of 2nd-D HPLC for 28 s, and 2 s was allowed for injection. (2) Two six-port valves each having a sample loop were used to hold the effluent of the 1st-D alternately for 30 s for one 2nd-D column to effect comprehensive 2D-HPLC without the loss of 1st-D effluent. (3) Two monolithic silica columns were used for 2nd-D by using a switching valve and two sets of 2nd-D chromatographs separating each fraction of the 1st-D effluent with the two 2nd-D columns alternately. In this case, two columns of the same stationary phase (C(18)) or different phases, C(18) and (pentabromobenzyloxy)propylsilyl-bonded (PBB), could be employed at the 2nd-D, although the latter needed two complementary runs. The systems produced peak capacity of approximately 1000 in approximately 60 min in cases 1 and 2 and in approximately 30 min in case 3. The three stationary phases, FR, C(18), and PBB, showed widely different selectivity from each other, making 2D separations possible. The simple and comprehensive 2D-HPLC utilizes the stability and high efficiency at high linear velocities of monolithic silica columns.     

Effects of rice cleaning and cooking process on the residues of flutolanil,fenobucarb, silafluofen and buprofezin in rice

We studied the effect of cleaning and cooking on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice. The rice had been sprayed in a paddy field in Wakayama city, with 3 kinds of pesticide application protocols: spraying once at the usual concentration of pesticides, repeated spraying (3 times) with the usual concentration of pesticides and spraying once with 3 times the usual concentration of pesticides. The residue levels of pesticide decreased during the rice cleaning process. Silafluofen, which has a higher log Pow value, remained in the hull of the rice. Fenobucarb, which has a lower log Pow value, penetrated inside the rice. The residue concentration of pesticide in polished rice was higher than that in pre-washed rice processed ready for cooking. During the cooking procedure, the reduction of pesticides in polished rice was higher than that in brown rice.     

Mid-infrared spectroscopic measurement of ionic dissociative materials in the metabolic pathway

We determine the pH dependency of the mid-infrared spectra in aqueous solution of the organic dissociative materials in the metabolic pathway: saccharide phosphates (G6P, F6P), adenosine, and its phosphates (ATP, ADP, AMP). The series of molar absorbance spectra for these reagents were obtained in a pH range of about 2 to 11 with a Fourier transform infrared (FT-IR) spectrometer equipped with a horizontal diamond attenuated total reflection (ATR) sampling accessory. We also provide a method of infrared spectral extraction of ionic dissociative materials by performing a linear least-square fitting utilizing the formulas of ionic dissociation equilibrium shift, and we obtain the infrared spectrum of each ionic species of the dissociative materials: G6P-, G6P2-; F6P-, F6P2-; ATP2-, ATP3-, ATP4-; ADP-, ADP2-, ADP3-; AMP, AMP-, AMP2-; and adenosine+, adenosine0. The infrared spectral structure of each ionic species of the dissociative materials in the metabolic pathway are discussed. Additionally, the possibility for a quantification system of the concentrations of the organic dissociative materials in varying pH is suggested.     

Dietary CLA and DHA modify skin properties in mice

This study investigated the influence of PUFA on the properties of mouse skin. Mice (3 wk old) were given free access to oils high in linoleic acid, CLA, or DHA for 4 wk. At the end of the experiment, their skins were compared by both biochemical and histological methods. No significant differences in lipid and collagen contents were detected among treatments, although the FA composition in the skin was altered depending upon the FA composition of the supplemented oils. Electron microscopy revealed that the subcutaneous tissue layers in the CLA and DHA groups were significantly thinner than that in the high linoleic acid group, whereas no differences in the thickness of dermis layers were observed among the three groups. These results suggest that skin properties in mice are readily modified by dietary FA sources within 4 wk of dietary oil supplementation.     

Cost effectiveness of reducing dioxin emissions from municipal solid waste incinerators in Japan

The main sources of dioxin emissions are municipal solid waste incinerators. The Japanese national government has set an emission standard for dioxins to reduce dioxin exposure levels. In this study, cost-effectiveness analyses are carried out regarding countermeasures that were recently taken and are being taken at municipal solid waste incinerators in Japan. Annual costs were estimated by telephone survey and model calculations. Annual decrease in the incidence of cancer was estimated in three steps. First, the annual decrease in the volume of dioxin emissions was estimated. Next, using a mathematical model, the annual decrease in human exposure was estimated. Finally, the annual decrease in the incidence of cancer was estimated by applying the cancer slope factor. When annual costs are divided by the annual number of life-years saved, cost per life-year saved (CPLYS) was obtained. CPLYS was estimated to be 7.9 million yen for emergency countermeasures and 150 million yen for long-term countermeasures. However, it must be noted that these obtained CPLYSs are highly dependent on the cancer slope factor and should be considered as an upper limit since there may be a cancer effect threshold.     

Degradation of thiometon in ethyl acetate

When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 microL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate. The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton. These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton.     

2-甲基-8-（9，9-二丁基芴）-3，5，7-三炔-2-辛醇的合成和性质研究

合成了一种新颖的乙炔衍生物，2-甲基-8-（9，9-二丁基芴）-3，5，7-三炔-2-辛醇（6a），并利用红外光谱（IR），紫外光谱（Uv），核磁（NMR），质谱（MS）等对其结构进行了表征。利用红外光谱（IR）和紫外光谱（Uv）对其拓扑固相聚合性质进行了研究。实验结果表明，这些化合物在加热和紫外光照射条件下都能够发生固相聚合，但得到的是结构复杂的聚合物。