Surfactant-disinfectant resistance of Salmonella and Staphylococcus adhered and dried on surfaces with egg compounds

To confirm the importance of eliminating food sediments from the surfaces of food-related environments, we examined the resistance of pathogenic bacteria (Salmonella Typhimurium and Staphylococcus aureus) cells, dried and adhered on glass with 25% w/v egg albumen, 25% yolk or 50% whole egg solutions, against benzalkonium chloride and alkyldiaminoethylglycine hydrochloride. Bacterial suspensions (0.1 ml of 8 log cfu/ml) were put on 47 mmφ glass dishes and dried at room temperature (20-24 °C) for 180 min in a bio safety cabinet with ventilation. Although the viable cells in distilled water decreased 2.0 (S. aureus)-3.5 (S. Typhimurium) log fold during the drying period, the egg compounds protected the bacteria. The disinfectant treatments (2.0 mg/ml for 10 min) showed a clear bactericidal effect in the absence of egg compounds. However, the bactericidal effect disappeared in the presence of yolk and whole egg. Imaging before and after drying and the disinfectant treatments were carried out using a phase-contrast microscope and an atomic force microscope. The protective effect of egg compounds on bacterial viability disappeared with a proper washing process.     

Self-organization in phase separation of a lyotropic liquid crystal into cellular, network and droplet morphologies

Phase separation is one of the most fundamental physical phenomena that controls the morphology of heterogeneous structures. Phase separation of a binary mixture of simple liquids produces only two morphologies: a bicontinuous or a droplet structure in the case of a symmetric or an asymmetric composition, respectively. For complex fluids, there is a possibility to produce other interesting morphologies. We found that a network structure of the minority phase can also be induced transiently on phase separation if the dynamics of the minority phase are much slower than those of the majority phase. Here we induce a cellular structure of the minority phase intentionally with the help of its smectic ordering, using phase separation of a lyotropic liquid crystal into the isotropic and smectic phase. We can control the three morphologies, cellular, network and droplet structures, solely by changing the heating rate. We demonstrate that the kinetic interplay between phase separation and smectic ordering is a key to the morphological selection. This may provide a new route to the formation of network and cellular morphologies in soft materials.     

Doppler-free spectroscopy using a continuous-wave optical frequency synthesizer

A continuous-wave (cw) optical frequency synthesizer is demonstrated by using a monolithic-type cw optical parametric oscillator (cw-OPO) and an optical frequency comb. The cw-OPO is phase locked to an optical frequency comb that is phase locked to an atomic clock. The output frequency of the cw-OPO is frequency shifted with an electro-optic modulator, which makes it possible to tune the frequency continuously over 10 GHz. Furthermore, Doppler-free spectroscopy is performed using the optical frequency synthesizer for a cesium D1 line at 895 nm. The observed linewidth of 5 MHz is the natural linewidth of cesium. The center frequency of the line is consistent with a previous report.     

Production technology and agglomeration for Japanese prefectures during 1991–2000*

We analyse the seemingly unrelated regression (SUR) models with spatial dependencies from a Bayesian point of view and estimate the parameters of the models using a Markov chain Monte Carlo (MCMC) method. Further, we analyse the production technology and the economics of agglomeration in Japanese prefectures from 1991 to 2000, simultaneously taking into account spatial and serial correlation. Model comparison is done via log‐marginal likelihoods, and it is found that the spatial error SUR model is the best model and that the economics of agglomeration and spatial heterogeneity decreased over this decade. Resumen. Analizamos modelos de ecuaciones aparentemente no relacionadas (SUR, siglas en inglés) con dependencias espaciales desde un punto de vista bayesiano y estimamos los parámetros de los modelos utilizando el método de Monte Carlo basado en cadenas de Markov (MCMC). Además, analizamos la tecnología de la producción y las economías de aglomeración en prefecturas japonesas desde 1991 a 2000, teniendo en cuenta simultáneamente la correlación espacial y serial. La comparación de modelos se realiza mediante verosimilitud log‐marginal, y se encontró que el error espacial del modelo SUR es el mejor modelo y que las economías de aglomeración y la heterogeneidad espacial disminuyeron durante esta década.      

Diurnal variations in H2O2, O3, PAN, HNO3 and aldehyde concentrations and NO/NO2 ratios at Rishiri Island, Japan: potential influence from iodine chemistry

The presence of iodine chemistry, hypothesized due to the overprediction of HO(2) levels by a photochemical box model at Rishiri Island in June 2000, was quantitatively tested against the observed NO/NO(2) ratios and the net production rates of ozone. The observed NO/NO(2) ratios were reproduced reasonably well by considering the conversion of NO to NO(2) by IO, whose amount was calculated so as to reproduce the observed HO(2) levels. However, the net production rates of ozone were calculated to be negative when such high mixing ratios of IO were considered, which was inconsistent with the observed buildup of ozone during daytime. These results suggest that iodine chemistry may not be the sole mechanism for the reduced mixing ratios of HO(2), or that "hot spots" for iodine chemistry were present. Diurnal variations in the mixing ratios of HCHO, CH(3)CHO, peroxy acetyl nitrate (PAN) and HNO(3) observed during the study are presented along with the simulated ones. The box model simulations suggest that the effect of iodine chemistry on these concentrations is small and that important sources of CH(3)CHO and sinks of PAN are probably missing from our current understanding of the tropospheric chemistry mechanism.     

Promotion of Anti-Wear Property of Sodium Stearate by Oxygen and Surface Active Agents

The anti-wear properties of a water-based lubricant were studied using a newly designed friction tester which enabled the rubbing with nascent surface under controlled atmospheres. Sodium stearate considerably reduced the wear of steel in oxygen rich atmospheres.

Supplementary adsorption tests were performed to identify the anti-wear film formed on the rubbed surface. Surface analysis by Fourier transform infrared spectroscopy (FTIR) revealed that metal stearate film was heavily formed on the rubbed surface in oxygen rich atmospheres. The measurement of metal elements in the protective film by atomic absorption spectroscopy clarified that the main constituent of the film was iron stearate. These results of adsorption tests could support that iron stearate might prevent the wear of steel in the wear test.

It was observed that a surface active agent prevented the formation of lubricative oxide film, but when used with sodium stearate, it synergistically promoted the anti-wear property of sodium stearate. This was attributed to the fact that the surface active agent improved the permeability of recrystallized sodium stearate to the rubbing area.     

Bonding Characteristics of Fiber-Reinforced Polymer Sheet-Concrete Interfaces under Dowel Load

Based on a series of experimental tests on notched concrete beams externally bonded with unidirectional fiber-reinforced polymer (FRP) sheets, this paper investigates the bond characteristics of FRP sheet-concrete interfaces under dowel load, which acts vertically on the FRP sheet and leads to a mix-mode interface peeling. The peeling properties of FRP sheet-concrete interfaces under the dowel load are evaluated in terms of their interface dowel load-carrying capacity, critical interface peeling angle, and interface peeling fracture energy. Experimental parameters include strength of concrete substrate, tension stiffness of FRP sheets, properties of bonding adhesives, concrete surface treatment methods, and length of precrack set between the FRP sheet and concrete substrate. Analytical models clarifying the relationships among the interface dowel load-carrying capacity, the interface peeling angle, and the interface peeling fracture energy are built up and also verified by test results. Further, this paper shows how to use the interface peeling fracture energy calibrated from the present dowel tests for the practical design of spalling prevention, which is now becoming a popular application of FRP sheets for the maintenance and repair of existing concrete structures in Japan.     

Uniform synthesis of multi-walled carbon nanotubes in a stainless steel porous block

High purity multi-walled carbon nanotubes (MWCNTs) were synthesized on the inner surfaces throughout a porous stainless steel cube with a 1 cm side having pores of approximately 300 μm diameter. For this synthesis, the inner surface of the stainless steel block was activated by heat treatment in O₂–Ar environment at 800 °C followed by reduction in H₂–Ar at 700 °C. This was followed by diffusing a mixture of ethylene and Ar into the pores for the formation of the MWCNTs. It was confirmed that the structure and purity of the MWCNTs synthesized in this stainless steel block were uniform.     

New carbon composites containing ultrafine metal particles. 2. Synthesis by pyrolisis of pitch-organometallic blends

Air-stable new carbon composites containing uniformly dispersed ultrafine Fe, Co, Ni, Ru, Pd, Rh, or Ag particles were obtained by thermal degradation of coal pitches mixed homogeneously with 1–10% of poly(vinyl ferrocene), cobaltocene, nickelocene, (acenaphthylene) Ru₃(CO)₇, PdCl₂(COD), RhCp(COD), and AgC₆H₄CH₂NMe₂, respectively, at 400–1200°C in Ar. Carbonization yields are 45–55% and the size of metal particles varied from 5 to 65 nm depending upon the treatment temperature and identity of the metal. The carbon composites containing Fe particles showed high Vicat hardness and good electrical conductivity. Pd- and Rh-dispersed materials exhibited good catalysis in hydrogenation of 1-hexene. The composite containing ultrafine Ag particles showed excellent bacteriostatic activity forEscherichia coli, Pseudomonas aeruginosa, andBatchillus subtilis.     

黏土和砂土简单的三维本构模型(英文)

把修正剑桥模型推广为适合于黏土和砂土的简单、统一三维本构模型是基于以下两点提出的 :第一点 ,把由笔者已提出的基于SMP准则的一个变换应力张量用于修正剑桥模型使其简单实现了三维化 ,改进的模型对于黏土实现了从剪切屈服到剪切破坏的统一及临界状态理论同SMP准则的结合 ;第二点 ,为了建立对于黏土和砂土简单、统一的本构模型 ,推导出了一个新的硬化参数 ,新硬化参数不仅能描述砂土不同程度的剪胀性 ,对于正常固结黏土又能退化成塑性体积应变 ,所提硬化参数的合理性也被各种路径下分别在三轴压缩和三轴伸长下的试验结果所证实。所提模型的计算参数仅为 5个常规试验参数 ,易于确定