Analyses of liquid film models applied to horizontal and near horizontal gas–liquid slug flows

An analysis of liquid film models for horizontal and near horizontal gas–liquid slug flows is developed. The models’ formulations employ the one dimensional separated phase momentum equations. The formulations differ among themselves, by neglecting some terms on the momentum balance and also on the closure relations. A comparative analysis discloses the differences amongst the formulations. The sensitivity of the liquid film models to the changes on the bubble velocity, liquid slug holdup and liquid viscosity is accessed through a series of parametric runs. Finally, the model is tested against experimental data taken for continuous horizontal slug flow. The tests were designed to check if the models are able to capture the stochastic film properties provided the properly closure relations.     

Modeling of extraction behavior of docosahexaenoic acid ethyl ester by utilizing slug flow prepared by microreactor

The liquid–liquid extraction dynamics of an ethyl ester of docosahexaenoic acid (DHA‐Et) with silver ion was investigated. The kinetic model was derived according to the following stepwise processes: Diffusion of DHA‐Et across the organic film, complex‐formation between DHA‐Et and silver ion at the interface, and diffusion of extracted complex across the aqueous film. The kinetic parameters for the complex‐formation reaction were determined from the investigation with the stirred transfer cell. With the proposed model and determined parameters, we predicted the uptakes of DHA‐Et for the extraction system utilizing a slug flow prepared by a microchip. The calculated uptakes showed good correlation to the experimental data. The theoretical investigation suggested that the fast equilibration realized for the slug flow extraction system was due to the large specific interfacial area of the slug caused by the presence of wall film and the thin liquid film caused by the internal circulation. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Simultaneous three-dimensional step-height measurement and high-resolution tomographic imaging with a spectral interferometric microscope

A noncontact, nonmechanical scanning, wide-field spectral interference microscope is developed for simultaneous measurement of three-dimensional step-height of discontinuous objects and tomographic imaging. A superluminescent diode (SLD) is used as a broadband light source and a liquid-crystal Fabry-Perot interferometer (LC-FPI) as a frequency-scanning device. By means of changing the injection current to the SLD, the spectral profile of the SLD is equalized, and a constant light input to the interferometer is achieved over the entire frequency-scan range. The Fourier-transform technique is used to determine both the amplitude and the phase of spectral fringe signals. Three-dimensional height distribution of a discontinuous object is obtained from the phase information, whereas optically sectioned images of the object are obtained either from the amplitude information alone or from the combination of both the amplitude and phase information. Experimental results with submicrometer resolution are presented for both step-height measurement and tomographic sectioning.     

Endoscopic sphincterotomy and laparoscopic cholecystectomy in an infant with cholecysto-choledocholithiasis

Laparoscopic cholecystectomy (LC) and endoscopic sphincterotomy (EST) are widely accepted procedures for cholecysto-choledocholithiasis in adults. However, their use in infants has not been reported. An 8-month-old girl presented with high fever and obstructive jaundice. Ultrasound scan showed acute cholecystitis with stones in the bile duct. After 2-week-long antibiotic therapy the acute cholecystitis and hepatic impairment resolved. An endoscopic retrograde cholangiopancreatography (ERCP) confirmed choledocholithiasis and cholecystolithiasis. Risk factors for the development of biliary calculi were not detected. One month after the restoration of her liver function, she underwent EST using a side-viewing endoscope with a small sphincterotome. A common bile duct stone was extracted using a basket catheter. LC was then carried out. The time interval between the EST and LC was 34 days. No complications have been noted for 6 months.     

Habitual coffee consumption and blood pressure: A study of self-defense officials in Japan

The degree of fat hydrogenation and the trans fatty acid content of the diet affect the fatty acid composition of membranes, and the amount and the activity of some membrane enzymes. We describe the effects of four isocaloric diets containing either sunflower oil (SO, 0% trans), fish oil (FO, 0.5% trans), partially hydrogenated fish oil (PHFO, 30% trans), or highly hydrogenated fish oil (HHFO, 3.6% trans) as fat sources on the lipid composition and the trans fatty acid content of rat hepatic microsomes. We also describe the effect of these diets on the cytochrome P-450 content and on the aminopyrine N-demethylase, aniline hydroxylase, and UDP-glucuronyl transferase microsomal activities. Cytochrome P-450 content was dependent on the degree of unsaturation of the diet, being higher for the FO-containing diet and lower for the HHFO diet. Aminopyrine N-demethylase activity also correlated with the degree of unsaturation of the diet as did the cytochrome P-450 content did (FO > SO > PHFO > HHFO). Aniline hydroxylase activity appeared to be independent of the degree of unsaturation of the dietary fat, but correlated with the trans fatty acid content of the diet, which was also reflected in the trans content of the microsomal membranes. UDP-glucuronyl transferase activity was higher for the FO-containing diet than for the SO diet, showing intermediate values after the PHFO and HHFO diets.     

Involvement of neutrophil elastase in crescentic glomerulonephritis

To elucidate the role of neutrophils in the tissue damage of crescentic glomerulonephritis (GN), we examined neutrophils infiltrated in renal tissues and the localization of neutrophil elastase (NE), as a neutrophil-derived tissue destructive mediator, using an immunohistochemical technique with antibodies specific for neutrophils and neutrophil elastase; the enzyme histochemical technique (chloroesterase staining) also was used to detect neutrophils. In normal controls, neutrophil infiltration was scarce, and NE was localized in neutrophil cytoplasm. Neutrophils were abundant in crescentic GN and infiltrated in the glomerulus and interstitium; the infiltrating neutrophils were often aggregated. NE was localized in the cytoplasm of neutrophils and also appeared extracellularly (in granular or diffuse patterns) in glomerular necrotizing lesions, crescents, ruptured portions of Bowman's capsules, and in periglomerular and perivascular sites of the interstitium. Moreover, urinary concentration of NE measured by enzyme-linked immunosorbent assay (ELISA) in crescentic GN patients was significantly higher than in normals (93.6 +/- 13.3 v 1.4 +/- 0.5 microg/g x Cr, respectively; P < .001). These data suggest that NE plays a significant role in renal tissue damage, especially in the formation of glomerular necrotizing and crescentic lesions and in periglomerular interstitial lesions of crescentic GN.     

Construction of 144, 565 keV and 5.0 MeV monoenergetic neutron calibration fields at JAERI

Monoenergetic neutron calibration fields of 144, 565 keV and 5.0 MeV have been developed at the Facility of Radiation Standards of JAERI using a 4 MV Pelletron accelerator. The 7Li(p,n)7Be and 2H(d,n)3He reactions are employed for neutron production. The neutron energy was measured by the time-of-flight method with a liquid scintillation detector and calculated with the MCNP-ANT code. A long counter is employed as a neutron monitor because of the flat response. The monitor is set up where the influence of inscattered neutrons from devices and their supporting materials at a calibration point is as small as possible. The calibration coefficients from the monitor counts to the neutron fluence at a calibration point were obtained from the reference fluence measured with the transfer instrument of the primary standard laboratory (AIST), a 24.13 cm phi Bonner sphere counter. The traceability of the fields to AIST was established through the calibration.     

External doses in the environment from the Tokai-mura criticality accident

On 30 September 1999, a criticality accident occurred at a uranium processing plant operated by JCO in Tokai-mura, Japan and the criticality remained for about 20 h. Almost all doses to the neighbouring residents were brought by neutrons and gamma rays emitted from the facility rather than fission products released to the environment. External doses in the environment were evaluated using radiation monitoring data and radiation transport calculation. A pattern of the dose rate evolution was modelled based on the records of gamma ray monitors in the JCO facilities. Relations between the ambient dose equivalent rates of neutrons/gamma rays and the distance from the facility were determined from the monitoring data obtained around the accident site. Conversion from the ambient dose equivalent to the effective dose equivalent was made assuming the energy spectra calculated by the radiation transport code, ANISN. It was estimated that the people who stayed outside the 350 m zone would receive doses of less than 1 mSv.     

Spectral interferometric microscope with tandem liquid-crystal Fabry-Perot interferometers for extension of the dynamic range in three-dimensional step-height measurement

The maximum measurable range of a spectral interference microscope depends on the coherence length of the light transmitted by its tunable spectral filter. To achieve a large range in step-height measurement we have developed a new tunable spectral filter that uses tandem liquid-crystal Fabry-Perot interferometers (LC-FPIs), which can simultaneously attain both a high spectral resolution and a large tuning range. Fringe visibility measurements were carried out, and it was found that the coherence length of the light transmitted through tandem LC-FPIs is two times larger than that transmitted through a single LC-FPI. Using this novel tunable spectral filter, we developed a new spectral interference microscope for the measurement of three-dimensional shapes of discontinuous objects. Experimental results of step-height measurements both with a single LC-FPI and with tandem LC-FPIs are presented for a combination of standard steel gauge block sets with 1-, 99-, and 100-microm steps. A large range (1-100 microm) of measurement with submicrometer resolution was achieved with tandem LC-FPIs that was not possible with our previous system in which a single LC-FPI was used.