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排序方式: 共有683条查询结果,搜索用时 31 毫秒
671.
Yoko Kitagawa Masahiro Okihashi Satoshi Takatori Keiji Kajimura Hirotaka Obana Masakazu Furuta Toshimasa Nishiyama 《Food Analytical Methods》2014,7(5):1066-1072
A rapid and simple method has been developed for the determination of 2-alkylcyclobutanone, 2-dodecylcyclobutanone (DCB), and 2-tetradecylcyclobutanone (TCB) in irradiated meat and processed foods. The procedure consists of extraction with n-hexane, following defatting and cleanup with a silica gel mini-column before gas chromatograph–mass spectrometry analysis. The method was evaluated using samples of beef, pork, Parmesan cheese, fried chicken, hamburger, gyoza (Chinese dumplings), and gyudon (boiled beef and onion seasoned with soy sauce and sugar). The recoveries of spiked DCB were 67–88 %, and those of TCB were 70–86 %. Furthermore, the method could detect DCB and TCB from samples irradiated at 1.0 and 2.6 kGy at levels dependent on dose; DCB and TCB were not detected in any nonirradiated samples. The method did not require special equipment, such as Soxhlet extraction, accelerated solvent extraction, or supercritical fluid extraction, for sample preparation. Thus, this method would be useful for determining DCB and TCB levels in irradiated meat and processed foods. 相似文献
672.
An optical wave microphone system is a new technique of sound measurement. This technique has been developed as a new plasma diagnostic technique to measure electron density fluctuations in the nuclear fusion research. Because the sound wave is a pressure or a density fluctuation, it is possible for this technique to measure the sound wave, too. The acoustical characteristics of the optical wave microphone system were examined by using a speaker as a first step. Next, feasibility of this device to measure jet noise was examined. It was found that the optical wave microphone system could measure the jet noise as well as a sound from speaker. Hence the optical wave microphone system can be considered one of the devices equivalent to condenser microphone. Because of these reason, this device is very convenient to scan the acoustic filed through jet flow from the inside to the out side and more preferable for not disturbing the observation field. 相似文献
673.
The VFH1 (YLL056C) promoter is vanillin‐inducible and enables mRNA translation despite pronounced translation repression caused by severe vanillin stress in Saccharomyces cerevisiae
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Trinh Thi My Nguyen Yoko Ishida Sae Kato Aya Iwaki Shingo Izawa 《Yeast (Chichester, England)》2018,35(7):465-475
674.
Leonardo Fonseca Maciel Ana Lúcia de Souza Madureira Felício Lucas Caldeirão Rodrigues Miranda Tassia Cavalcante Pires Eliete da Silva Bispo Elisa Yoko Hirooka 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(1):134-143
Brazil is the sixth largest producer of cocoa beans in the world, after Côte d’Ivoire, Ghana, Indonesia, Nigeria and Cameroon. The southern region of Bahia stands out as the country’s largest producer, accounting for approximately 60% of production. Due to damage caused by infestation of the cocoa crop with the fungus Moniliophthora perniciosa, which causes ‘witch’s broom disease’, research in cocoa beans has led to the cloning of species that are resistant to the disease; however, there is little information about the development of other fungal genera in these clones, such as Aspergillus, which do not represent a phytopathogenicity problem but can grow during the pre-processing of cocoa beans and produce mycotoxins. Thus, the aim of this work was to determine the presence of aflatoxin (AF) and ochratoxin A (OTA) in cocoa clones developed in Brazil. Aflatoxin and ochratoxin A contamination were determined in 130 samples from 13 cocoa clones grown in the south of Bahia by ultra-performance liquid chromatography with a fluorescence detector. The method was evaluated for limit of detection (LOD) (0.05–0.90 μg kg?1), limit of quantification (0.10–2.50 μg kg?1) and recovery (RSD) (89.40–95.80%) for AFB1, AFB2, AFG1, AFG2 and OTA. Aflatoxin contamination was detected in 38% of the samples in the range of ?1, with AFB1 in 25% of the total samples, whereas ochratoxin A was positive in 18% of the samples in the range of ?1. 相似文献
675.
Yoko Matsuzawa Satoshi Noguchi Hideki Sakai Masahiko Abe Mutsuyoshi Matsumoto 《Thin solid films》2006,510(1-2):292-296
Hybrid Langmuir and Langmuir–Blodgett (LB) films consisting of amphiphilic cyclodextrins (CDs) and hydrophobic azobenzene were fabricated. Due to the larger cross-sectional area of the CD core compared with the sum of the cross-sectional areas of the attached alkyl chains, the films had free space in the hydrophobic regions. Azo(p-Hexyl) having hydrophobic terminal chains was accommodated in the free space, whereas the usage of an azobenzene derivative bearing hydrophilic groups led to the phase separation. The average tilt angle of Azo(p-Hexyl) gave minima when the free space was just filled with Azo(p-Hexyl). Photoisomerization of azobenzenes in the hybrid LB films was studied. 相似文献
676.
In the present paper. a numerical model for MAG (metal active gas) arc welding of thin plate has been developed. In MAG arc welding, the electrode wire is melted and supplied into the molten pool intermittently. Accordingly, it is assumed on the modeling that the thermal energy enters the base-plates through two following mechanisms, i.e., direct heating from arc plasma and "indirect" heating from the deposited metal. In the second part of the paper, MAG arc welding process is numerically-analyzed by using the model. and the calculated weld bead dimension and surface profile have been compared with the experimental MAG welds on steel plate. As the result. it is made clear that the model is capable of predicting the bead profile of thin-plate MAG arc welding, including weld bead with undercutting. 相似文献
677.
678.
Satoshi Seino Yasuo Imoto Daijiro Kitagawa Yoshiki Kubo Tomoya Kosaka Takao Kojima 《Journal of Nuclear Science and Technology》2016,53(7):1021-1027
This paper presents a new technique for synthesizing silver nanoparticles immobilized on textile fabrics using a radiochemical process. In this process, the irradiation of a high-energy electron beam on an aqueous solution containing silver ions induces a reducing reaction that forms metallic silver nanoparticles. Small Ag particles of about 2–4 nm were observed together with relatively large particles of more than 10 nm. These nanoparticles are firmly immobilized on the surface of a support textile fabric without the need for any binder or surfactant. The amount of silver nanoparticles immobilized was found to depend on the water content of the support textile fabric, suggesting that the silver ions are reduced not only by radiochemical species generated by the radiolysis of water, but also by radiochemical species generated in the irradiated support fabric itself. The silver nanoparticles that were immobilized on the support textile fabric exhibited an excellent antibacterial activity across a wide antibacterial spectrum, even after a durability test involving washing the fabric 100 times. 相似文献
679.
Hiroki Koike Kazuya Yamaji Kazuki Kirimura Shinya Kosaka Hideki Matsumoto Akio Yamamoto 《Journal of Nuclear Science and Technology》2016,53(6):842-869
A new hybrid resonance self-shielding treatment method in reactor physics field is developed by integrating equivalence theory and ultra-fine-group slowing-down calculation from the theoretical point of view. In the conventional equivalence theory, scattering source approximation and taking no account of resonance interference effect cause prediction error of effective cross-section. By reviewing the derivation scheme of neutron flux in the equivalence theory, the essence of the ultra-fine-group treatment is effectively incorporated. A new form of energy-dependent flux is based on multi-term rational equation, but the scattering source can be solved by the way similar to the slowing-down equation. The accurate non-fuel flux is also considered without direct heterogeneous calculation. The new method can also efficiently eliminate the multi-group condensation error by a semi-analytical reaction rate preservation scheme between ultra-fine and multi-group treatments. The present method is implemented in Mitsubishi Heavy Industries, Ltd. lattice physics code GALAXY. From comparisons of neutronics parameters between GALAXY and a continuous energy Monte-Carlo code, applicability of the new method for lattice physics calculations is confirmed. GALAXY achieves high accuracy with short computation time. Therefore, it can be efficiently applied to generation of the nuclear constants used in the nuclear design and safety analysis of commercial light water reactors. 相似文献
680.
Generally, the foods we usually eat are not only aqueous solutions, but also viscous solutions and solids. Therefore, it is interesting for us to explore how taste components are perceived in a viscous polymer solution. The relationship between the sensory evaluation of saltiness intensity, amount of added oil, and apparent viscosity was clarified in low-viscosity and high-viscosity polymer solutions. The study was conducted using samples containing corn oil, sodium chloride, and [xanthan gum] or [xanthan gum + locust bean gum] as a thickener. Oil was added to the viscous polymer solutions regardless of whether they were low- or high-viscosity, and saltiness intensity was evaluated as compared with a reference solution. The low-viscous polymer solutions with [xanthan gum] were perceived to be saltier than the high-viscous polymer solutions with [xanthan gum + LBG] as the amount of oil increased. The shear stress value gradually increased as the amount of oil increased in both the low-viscosity and the high-viscosity polymer solutions, as derived from the fluid constitutive equation. There was a correlation between saltiness intensity and apparent viscosity in both high- and low-viscosity polymer solutions. A coefficient of determination (R2) of 0.918 was obtained between saltiness intensity and “apparent viscosity” for the samples using [xanthan gum] and that of 0.683 between saltiness intensity and “apparent viscosity” for the samples using [xanthan gum+LBG]. The low-viscosity polymer solutions showed a saltier intensity as the amount of oil increased and a greater correlation with apparent viscosity, as compared with the high-viscosity polymer solutions. 相似文献