Estimation of spectral transmission of dried seaweed from its digital image

Estimation of spectral transmission characteristics of dried seaweed has been made starting with its digital image, that is, the RGB values. The present estimation method has steps comprising the capture of a digital transmission image and evaluation of the optical transmission characteristics of a seaweed sample for learning. Next, an estimation equation based on the information derived from the learning data is established, and an optical transmission curve of the seaweed sample is generated with the RGB values of its digital image according to the estimation equation. With this method, optical transmission curves have been estimated at the wavelength range 400–700 nm with a root mean square error of about 2%. In addition, the pigment content of seaweed has been also estimated successfully by means of the estimated transmission curve, though the result is only semiquantitative. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Real-time imaging of single-molecule fluorescence with a zero-mode waveguide for the analysis of protein-protein interaction

Real-time imaging of single-molecule fluorescence with a zero-mode waveguide (ZMW) was achieved. With modification of the ZMW geometry, the signal-to-background ratio is twice that obtainable with a conventional ZMW. The improved signal-to-background ratio makes it possible to visualize individual binding-release events between chaperonin GroEL and cochaperonin GroES at a concentration of 5 microM. Two rate constants representing two-timer kinetics in the release of GroES from GroEL were measured with the ZMW, and the measurements agreed well with those made with a total internal reflection fluorescence microscopy. These results indicate that the novel ZMW makes feasible the direct observation of protein-protein interaction at an intracellular concentration in real time.     

Biodegradation of caffeine: Formation of theophylline and theobromine from caffeine in mature Coffea arabica fruits

The level of theophylline in mature and ripened fruit is 20–50 times that in the immature green fruit of Coffea arabica L. Biodegradation of caffeine occurs in the mature, ripened coffee fruits through theophylline and theobromine as the first biodegradation products. It is now clear that theophylline is associated primarily with caffeine biodegradation, whereas theobromine is involved in both biosynthesis and biodegradation of caffeine.     

Experimental investigations of the indoor natural ventilation for different building configurations and incidences

This paper presents an experimental investigation of the indoor natural ventilation in terms of wind pressures on the surfaces of cubic buildings of a street located within a high density urban area. Wind tunnel tests over 1:100 scale models for four typical building patterns of a highly populated urban area have been carried out. The variables of the experiments were the building configurations and the incident wind direction. The experimental data are presented in terms of wind pressure coefficient measured on the surfaces of the buildings. The study results gave the evidence that buildings configuration and wind direction are very important factors in determining the induced natural ventilation within urban domains since they characteristically influence the flow yielding differences in wind pressures.     

Screening assay of residual antibiotics in livestock samples by LC-MS/MS

A LC-MS/MS screening assay of multi-class antibiotics was developed for 19 residual antibiotics in livestock samples. Sample preparation employed the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach using 0.5% formic acid in acetonitrile-methanol (8 : 2), with salting-out using magnesium sulfate, trisodium citrate and sodium chloride. Recovery values from 5 different livestock samples ranged from 45.5 to 121.6%, and the RSDs were under 18% at two concentration levels. The limit of quantification values of 19 analytes were under 10 μg/kg in all livestock samples, and the procedure can detect almost all analytes under the MRL. Screening capability was confirmed by employing spiked samples. This new screening assay for residual antibiotics in livestock samples is expected to be useful for routine laboratory tests.     

Shape-engineerable and highly densely packed single-walled carbon nanotubes and their application as super-capacitor electrodes

We present a rational and general method to fabricate a high-densely packed and aligned single-walled carbon-nanotube (SWNT) material by using the zipping effect of liquids to draw tubes together. This bulk carbon-nanotube material retains the intrinsic properties of individual SWNTs, such as high surface area, flexibility and electrical conductivity. By controlling the fabrication process, it is possible to fabricate a wide range of solids in numerous shapes and structures. This dense SWNT material is advantageous for numerous applications, and here we demonstrate its use as flexible heaters as well as supercapacitor electrodes for compact energy-storage devices.     

Changes of aquaporin 5-distribution during release and reaccumulation of secretory granules in isoproterenol-treated mouse parotid gland

Water channel aquaporin 5 (AQP5) is present in the apical membrane of the salivary gland acinar cells. We examined changes of AQP5-distribution during the fusion process of secretory granule membranes into the apical membrane and subsequent recovery process in the mouse parotid gland by administering isoproterenol (IPR) in vivo. We performed immunoperoxidase, immunofluorescence and immunoelectron microscopy. In the basal state, AQP5 was localized mainly in the apical membrane of the acinar cell. It was also present in the basolateral membrane to a lesser extent. When IPR was administered to mice, dot-like, vesicle-like and vacuole-like labeling for AQP5 was seen in the subapical regions by light microscopy. By immunoelectron microscopy, AQP5 was localized at both the apical and basolateral plasma membranes in the basal state. At 5 and 30 min after the IPR-administration, acinar lumen became enlarged and small invaginations formed by fusion of secretory granules were seen. AQP5 was positive along the apical plasma membrane and its small invaginations. At 60 min, large invaginations of the lumen were formed. AQP5 remained positive in the membrane of these large invaginations. At 6 h, large invaginations disappeared and AQP5 was localized in the apical plasma membrane. AQP5 was restricted to plasma membranes and continuous invaginations formed by the exocytosis of secretory granules. AQP5 was not detected in the cytoplasm. These observations show that AQP5 does not seem to be endocytosed during the membrane recycling process following the exocytosis.     

NOx Sensing Properties of Varistor-Type Gas Sensors Consisting of Micro p-n Junctions

NO _x sensing properties of SnO₂-xCr₂O₃ as a varistor-type gas sensor have been investigated in the temperature range of 200–600°C. The breakdown voltage of SnO₂ shifted to a higher electric field upon exposure to NO₂ at 300–500°C, and the largest breakdown voltage shift, i.e. the highest NO₂ sensitivity was observed at 400°C. In contrast, the direction of the breakdown voltage shift in NO varied with temperature: the breakdown voltage shifted to a lower electric field at 300°C, but to a higher electric field at 500°C, and remained almost unchanged at 400°C. The NO₂ sensitivity of SnO₂ was superior to the NO sensitivity at every temperature, and then the SnO₂ exhibited good selectivity to NO₂ at 400°C. The breakdown voltage of Cr₂O₃ shifted in the reverse direction upon exposure to NO and NO₂, in comparison with those observed with SnO₂, owing to its p-type semiconductivity. Thus, Cr₂O₃ also exhibited certain sensitivity to both NO and NO₂ at 200°C, being more sensitive to NO₂, though the sensitivities decreased drastically at temperatures higher than 300°C. The addition of 5.0 wt% Cr₂O₃ to SnO₂ resulted in a significant improvement of NO and NO₂ sensitivities at 600°C, being accompanied by an increase in the breakdown voltage in air. Especially, the NO sensitivity was superior to the NO₂ sensitivity in the concentration range of 20–100 ppm, and then SnO₂ mixed with 5.0 wt% Cr₂O₃ was found to be the most suitable candidate for a NO sensor among the sensors tested. The increase in the breakdown voltage in air induced by the Cr₂O₃ addition was confirmed to arise from both the decrease in the particle size of SnO₂ and the formation of micro p-n junctions at grain boundaries. The decrease in the particle size was also responsible for the increased NO and NO₂ sensitivities, but the p-n junctions were suggested to play a more important role in promoting and stabilizing the chemisorption of NO at higher temperatures.     

近源地震的特性及其对RC柱延性的影响

介绍了近源地震的特点,研究了RC柱在近源地震时的延性特性.计算结果表明,近源地震的垂直地面运动的幅值和频率成分对柱的延性和拟加速度响应有很大影响,对位于近源地震区域的建筑物的抗震设计有必要考虑垂直地面荷载.     

A remedy for the temperature recovering method of solidification simulation

One of the methods of phase change simulation is the “temperature recovering method.” It has two main difficulties in practical application. The first one is the explicit nature of the method. The second one is the slow convergence of the solidification ratio. In this study, a method has been proposed to improve these difficulties. The method consists of two procedures. First, the solidification range is clustered into a discrete variable. A solidification ratio is sorted within a cluster as an integer variable. Second, the source term related to the change of the latent heat is reformulated into an implicit form by the “numerical linearization method” as previously proposed by the author. The benchmark test cases show that: (1) The convergence is faster, even for large latent heat cases, than the existing method. (2) The stability is independent of the time increment. © 2000 Scripta Technica, Heat Trans Asian Res, 29(5): 400–411, 2000