Fin efficiency of serrated fins. Part 4. Correction factor for inline arrangement

A correction factor to the theoretical fin efficiency of serrated fins, reported in Part 1 and Part 2 of this report, was derived for an inline arrangement experimentally. The experiment was performed using an open‐type wind tunnel with six kinds of test finned‐tubes made of copper, carbon steel and stainless steel, which were arranged in one to five rows. Heat transfer measurement was done by the local thermal simulation method. The derived correction factor for the 1st row was the same as for staggered arrangement reported in Part 3, for the 2nd and deeper rows, however, a further correction was needed, which may be caused by the difference in the nonuniformity in heat transfer coefficient over the fin surface. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(4): 258–269, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20008     

Heat transfer and pressure loss characteristics of a heat exchanger for recovering latent heat (effects of straight fin length and fin pitch on the heat transfer and pressure loss characteristics)

In recent years, the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. A latent heat recovery type heat exchanger is one of the effective methods for improving thermal efficiency by recovering latent heat. This paper describes the heat transfer and pressure loss characteristics of a latent heat recovery type heat exchanger having straight fins (fin length: 65 mm or 100 mm, fin pitch: 2.5 mm or 4 mm). These were clarified by measuring the exchange heat quantity, the pressure loss of the heat exchanger, and the heat transfer coefficient between the outer fin surface and gas. The effects of fin length and fin pitch on heat transfer and pressure loss characteristics were clarified. Furthermore, equations for predicting the heat transfer coefficient and pressure loss which are necessary for heat exchanger design were proposed. ©2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(4): 230– 247, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20153 Copyright © 2004 Wiley Periodicals, Inc.     

Flow cytometric analysis of lectin-oligosaccharide interactions by using fluorescent oligosaccharide probes

Tetraphenylethylene (TPE) derivatives have strong fluorescence in aggregated state. We report here an oligosaccharide binding assay system using tetraphenylethylene derivatives bearing oligosaccharides with aggregation-induced emission (AIE) characteristics. A tetraphenylethylene derivative bearing 6'-sialyllactose (6'SL) bound to microbeads coated with SSA lectin more effectively than RCA120 lectin. Microbeads that bound to fluorescent oligosaccharide probes could be detected by flow cytometric analysis. Tetraphenylethylene derivatives bearing oligosaccharides are useful for flow cytometric analysis of lectin-oligosaccharide interactions.     

Evaluation of the possibility that free fatty acids cause false-positive result in diarrhetic shellfish poisoning mouse bioassay in actual use

Midgut glands of bivalves are used for the mouse bioassay of diarrhetic shellfish poison (DSP). A large quantity of free fatty acids (FFAs) causes a false positive outcome in the assay. To examine whether this is likely to occus under conditions of actual use, we analyzed the contents of the FFAs in the enlarged midgut glands during gametogenesis of Japanese scallops Patinopecten yessoensis that had been caught at two points in Hunka Bay on March 27, 2006, because the content of FFAs may increase with activation of lipogenesis for gametogenesis. Fatty acids (FAs) were measured with fluorometric high-performance liquid chromatography after derivatization with 9-anthryldiazomethane. The total FFAs (14 : 0, 16 : 0, 18 : 0, 16 : 1, 18 : 1, 18 : 4, 20 : 5 and 22 : 6) represented 3.3-4.2 wt% of the lipid. The toxic FFAs accounted for 40-43 wt% of the total FFAs. Content of each FFA (18 : 1, 2.7-5.0 mg/g lipid; 18 : 4, tr.-2.0 mg/g; 20 : 4, n.d.; 20 : 5, 8.0-9.1 mg/g and 22 : 6, 2.0-2.1 mg/g) was lower than the lethal dose tentatively calculated from the relative toxicity. It appears that the likelihood of FFAs causing false-positives in the mouse bioassay is low if the sample is fresh and is extracted immediately after homogenizing.     

Compensation algorithm for the phase-shift error of polarization-based parallel two-step phase-shifting digital holography

We propose an algorithm for compensating the phase-shift error of polarization-based parallel two-step phase-shifting digital holography, which is a technique for recording a spatial two-step phase-shifted hologram. Although a polarization-based system of the technique has been experimentally demonstrated, there had been the problem that the phase difference of two phase-shifted holograms had been changed by the extinction ratio of the micropolarizer array attached to the image sensor used in the system. To improve the performance of the system, we established and formulated an algorithm for compensating the phase-shift error. Accurate spatial phase-shifting interferometry in the system can be conducted by the algorithm regardless of phase-shift error due to the extinction ratio. By the numerical simulation, the proposed algorithm was capable of reducing the root mean square errors of the reconstructed image by 1/4 and 1/5 in amplitude and phase, respectively. Also, the algorithm was experimentally demonstrated, and the experimental results showed that the system employing the proposed algorithm suppressed the conjugate image, which slightly appeared in the image reconstructed by the system not employing the algorithm, even when the extinction ratio was 10:1. Thus, the effectiveness of the proposed algorithm was numerically and experimentally verified.     

Model Test and Consolidation Analysis of Failure of a Loose Sandy Embankment Dam During Seepage

Failures of earth dam embankments and river dikes, which are constructed of sandy soils with low dry densities, have been observed to occur during rising of water levels. In this paper, a large-scale physical model test was conducted in order to investigate the behavior of a small dam embankment as water levels rose. The test results were simulated by use of a consolidation analysis method coupled with an elastoplastic model for unsaturated soils. All parameters used in the simulation were obtained from element tests; oedometer, triaxial compression, soil water retention, and permeability tests. First, in order to verify the parameters identified, direct shear tests were simulated using the consolidation analysis method; results of the simulation and the tests were consistent. From the embankment model test it was found that the crest of the embankment moved upstream at the first stage of impounding and then moved back. After a seepage surface appeared on the downstream slope, tension cracks occurred on the downstream slope, and sliding occurred through the crack and the downstream toe. The results of the simulation were consistent with those of the model test. This consolidation analysis method could be used to simulate the complex deformations induced by saturation collapse and shear strains and even failure behavior. Old embankments constructed with loose densities might have histories in which cracks occurred on the downstream slopes when the reservoir water level rose, and their stabilities might have decreased.