Study of pesticide residues in agricultural products for the "Positive List" system

During a 3-year monitoring survey (April 2002-March 2005) of pesticide residues in agricultural products, 592 samples (324 domestic; 268 imported) collected in Hyogo prefecture, Japan were analyzed. The number of pesticides tested increased from 232 in FY 2002 to 323 in FY 2004. The purpose of the study was to clarify the residue status by accumulating information about pesticides detected frequently, to allow effective and efficient regulation under the new "Positive List" legislation to be implemented in FY 2006. Overall, 47% of domestic and 61% of imported samples contained detectable residues and ca. 60% of positive samples contained multiple residues. The limit of quantitation was set at 0.01 microg/g and the limit of detection was 0.001-0.003 microg/ g. Most of the residues were present at low concentrations: 80% of the detections in samples excluding imported citrus fruits were < 0.05 microg/g. More than 5 different pesticides (> 0.01 microg/g) were detected simultaneously in 13 samples. The sum of the ratios of residues to MRLs was calculated as one of the indexes to represent the risk of multiple residues, and they exceeded 100% in 3 imported frozen vegetables; baby kidney bean, spinach, Welsh onion. Samples in violation of the Food Sanitation Law were not found in our survey, but 1.9% of the samples might be in conflict with the new "Positive List" legislation.     

Formation mechanism of InxGa1−xAs ohmic contacts to n-type GaAs prepared by radio frequency sputtering

The formation mechanisms of InAs/Ni/W ohmic contacts to n-type GaAs prepared by radio-frequency (rf) sputtering were studied by measuring contact resistances (R_c) using a transmission line method and by analyzing the interfacial structure mainly by x-ray diffraction and transmission electron microscopy. Current-voltage characteristics of the InAs/Ni/W contacts after annealing at temperatures above 600°C showed “ohmic-like behavior.” In order to obtain the “ohmic” behavior in the contacts, pre-heating at 300°C prior to high temperature annealing was found to be essential. The contacts showed ohmic behavior after annealing at temperatures in the range of 500∼850°C and contact resistance values of as low as ∼0.3Ω-mm were obtained. By analyzing the interfacial structures of these contacts, In_xGa_1−xAs layers with low density of misfit dislocations at the In_xGa_1−xAs and GaAs interface were observed to grow epitaxially on the GaAs substrate upon heating at high temperatures. This intermediate In_xGa_1−xAs layer is believed to divide the high energy barrier at the contact metal and GaAs interface into two low barriers, resulting in reduction of the contact resistance. In addition, Ni was found to play a key role to relax a strain in the In_xGa_1−xAs layer (introduced due to lattice mismatch between the In_xGa_1−xAs and GaAs) by forming an intermediate Ni_xGaAs layer on the GaAs surface prior to formation of the In_xGa_1−xxAs layer.     

Melt spinning and metal chloride vapor curing process on polymethylsilsesquioxane as Si?O?C fiber precursor

Melt spinning process of polymethylsilsesquioxane (PMSQ) at 403–453 K was investigated as a Si? O? C fiber precursor in terms of averages and distributions of spun fiber diameters. Because of fusible character of PMSQ at low temperature, the spun fibers were exposed to vapors of various metal chlorides (SiCl₄, Si(CH₃)Cl₃, TiCl₄, and BCl₃) to promote the fiber curing. Cured fibers were investigated by FTIR and TG analyses. In a case of the fiber synthesized with SiCl₄ curing, tensile tests on the pyrolyzed fibers were performed. Exposure of the synthesized fiber at high temperature with a flame of an oxygen‐gas burner was examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Spray Pyrolysis of Fe3O4–BaTiO3 Composite Particles

Fe₃O₄–BaTiO₃ composite particles were successfully prepared by ultrasonic spray pyrolysis. A mixture of iron(III) nitrate, barium acetate and titanium tetrachloride aqueous solution were atomized into the mist, and the mist was dried and pyrolyzed in N₂ (90%) and H₂ (10%) atmosphere. Fe₃O₄–BaTiO₃ composite particle was obtained between 900° and 950°C while the coexistence of FeO was detected at 1000°C. Transmission electron microscope observation revealed that the composite particle is consisted of nanocrystalline having primary particle size of 35 nm. Lattice parameter of the Fe₃O₄–BaTiO₃ nanocomposite particle was 0.8404 nm that is larger than that of pure Fe₃O₄. Coercivity of the nanocomposite particle (390 Oe) was much larger than that of pure Fe₃O₄ (140 Oe). These results suggest that slight diffusion of Ba into Fe₃O₄ occurred.     

Densification and Cell Performance of Gadolinium-Doped Ceria (GDC) Electrolyte/NiO–GDC Anode Laminates

A thin film (60 μm thick) of a gadolinium-doped ceria (GDC) electrolyte was prepared by the doctor blade method. This film was laminated with freeze-dried 42 vol% NiO–58 vol% GDC mixed powder and pressed uniaxially or isostatically under a pressure of 294 MPa. This laminate was cosintered at 1100 °–1500 °C in air for 4–12 h. The laminate warped because of the difference in the shrinkage of the electrolyte and electrode during the sintering. A higher shrinkage was measured for the electrode at 1100 °–1200 °C and for the electrolyte at 1300 °–1500 °C. The increase of the thickness of anode was effective in decreasing the warp and in increasing the density of the laminated composite. The maximum electric power density with a SrRuO₃ cathode using 3 vol% H₂O-containing H₂ fuel was 100 mW/cm² at 600 °C and 380 mW/cm² at 800 °C, respectively, for the anode-supported GDC electrolyte with 30 μm thickness.     

Effect of light intensity and frequency of flashing light from blue light emitting diodes on astaxanthin production by Haematococcus pluvialis

Flashing light from blue light emitting diodes is an effective method for the reduction of energy consumption in the bioproduction of astaxanthin by Haematococcus pluvialis. We investigated the effects of light intensity and frequency on the final astaxanthin concentration in bioproduction by H. pluvialis grown mixotrophically. The final astaxanthin concentration under illumination with flashing light, with frequencies ranging from 25 to 200 Hz, was dependent on the light intensity and on the duty cycle and was equivalent, or higher, in comparison with that under illumination with continuous light at the same incident intensity. The light intensity determined the maximum attainable concentration of astaxanthin under continuous illumination. Under illumination with flashing light, the ratio of the final astaxanthin concentration to the maximum concentration at a specific light intensity was correlated to the duty cycle in the frequency range from 25 to 200 Hz. The effect of lower frequencies on enhanced astaxanthin production under flashing light was also studied; at levels as low as 1 Hz, higher final astaxanthin concentrations were observed under flashing light compared to concentrations attained under continuous light.     

Resistance to aerobic deterioration of total mixed ration silage: effect of ration formulation,air infiltration and storage period on fermentation characteristics and aerobic stability

BACKGROUND: High aerobic stability can be expected when wet brewers' grains are stored as a total mixed ration (TMR) silage. To understand the factors affecting the stability, the effects of ration formulation, air infiltration and storage period were studied. RESULTS: A TMR containing wet brewers' grains, hay, maize, wheat bran, beet pulp and molasses was ensiled in laboratory silos for 14 and 56 days. The effects of hay species (lucerne or sudangrass) and air infiltration (Exp. 1) and of excluding one, two or three items from the six ingredients (Exp. 2) were examined. Ethanol was the main fermentation product in all TMR silages in this study. Aerobic deterioration occurred in 14 day silages prepared with sudangrass hay along with air infiltration (Exp. 1), and with the simplest recipe where three items (hay, maize and wheat bran) were excluded (Exp. 2). No deterioration occurred in 56 day silages regardless of ration formulation and air infiltration. Yeasts receded in 56 day silages, except with the simplest recipe, to the 10² cfu g^?1 level and remained undetectable in the presence of air (Exp. 2). CONCLUSION: TMR silage can resist aerobic deterioration provided that a sufficient ensiling period has elapsed. Silages stored for only a few weeks may be susceptible to deterioration when air is infiltrated or where fewer ingredients are used in the TMR mixture. Copyright © 2007 Society of Chemical Industry     

Effect of skimmed milk and its fractions on the inactivation of Escherichia coli K12 by high hydrostatic pressure treatment

We investigated the effects of skimmed milk and its protein fractions (casein, whey, globulin, and albumin) on the injury and inactivation of Escherichia coli K-12 by high hydrostatic pressure (HHP) treatment. The protective effect of skimmed milk on HHP-mediated inactivation and injury of E. coli increased with increases in the skimmed milk concentration. However, protein fractions derived from skimmed milk did not exhibit this protective effect. Microscopy analysis by DAPI/PI staining indicated that some cells were localized in the solid portion of skimmed milk, and some of these cells were alive. The coagulated fraction derived from the autoclaved whey fraction also showed a significant protective effect. We speculate that the solid portion in skimmed milk could provide the protective effect to bacterial cells.     

Design of energy‐efficient train speed profiles considering fixed‐block signaling system

In dense traffic railway networks, trains may often slow down or stop between stations owing to previous train delays. If preceding train trajectory can be predicted, energy‐efficient driving can be achieved by suppressing unnecessary speed changes. In this paper, we propose an algorithm to find energy‐efficient driving considering fixed‐block signaling (FBS) system by using dynamic programming (DP). DP is suitable for use because it can optimize the control inputs with discrete and state constraints. In this paper, we discuss energy‐efficient driving by considering a FBS system using some case studies of simulation. In the simulation, we examine a technique to drive an express train in an energy‐efficient way when the preceding local train is running toward the station with passing loops. The results show that the proposed method can derive complex speed profiles for energy‐efficient driving and the train can be operated with a maximum reduced energy consumption of 8.3%.