Coolant Wetting Simulation on Simplified Stator Coil Model by the Phase-Field Lattice Boltzmann Method

Stator coils of automobiles in operation generate heat and are cooled by coolant poured from above. The flow characteristic of the coolant depends on the coil structure, flow condition, solid–fluid interaction, and fluid property, which has not been clarified due to its complexities. Since straight coils are aligned and layered with an angle at the coolant-touchdown region, the coil structure is simplified to a horizontal square rod array referring to an actual coil size. To obtain the flow and wetting characteristics, two-phase fluid flow simulations are conducted by using the phase-field lattice Boltzmann method. First, the flow onto the single-layered rod array is discussed. The wetting area is affected both by the rod gap and the wettability, which is normalized by the gap and the averaged boundary layer thickness. Then, the flow onto the multi-layered rod arrays is investigated with different rod gaps. The top layer wetting becomes longitudinal due to the reduction of the flow advection by the second layer. The wetting area jumps up at the second layer and increases proportionally to the below layers. These become remarkable at the narrow rod gap case, and finally, the dimensionless wetting area is discussed at each layer.     

Reduced stress‐optical coefficient of polycarbonate by antiplasticization

We have investigated the effect of antiplasticization on the stress‐optical behavior of polycarbonate (PC) containing terphenyls (tPh) and di(2‐ethylhexyl)adipate (DEHA). Addition of the three tPhs (p‐, o‐, and m‐tPh) and DEHA at contents of 5–10 wt % increases the tensile storage modulus (E' ) of PC owing to the antiplasticization effect. In particular, p‐tPh increases E' more than the other additives, suggesting that the rod‐like shape matches the free volume of PC in the glassy state. The three tPh isomers improve the glassy birefringence of PC while DEHA does not change the glassy birefringence, which corresponds to the polarizability anisotropy. The stress‐optical coefficient, a ratio of stress and birefringence, of PC decreases with increasing additive content in order of p‐tPh ? o‐tPh > m‐tPh = DEHA. This result is agreement with a restricted rotational motion of additive molecule in PC, which is observed in dynamic mechanical and birefringence data. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1837–1842     

A finite element/volume method model of the depth‐averaged horizontally 2D shallow water equations

Analysis of surface water flows is of central importance in understanding and predicting a wide range of water engineering issues. Dynamics of surface water is reasonably well described using the shallow water equations (SWEs) with the hydrostatic pressure assumption. The SWEs are nonlinear hyperbolic partial differential equations that are in general required to be solved numerically. Application of a simple and efficient numerical model is desirable for solving the SWEs in practical problems. This study develops a new numerical model of the depth‐averaged horizontally 2D SWEs referred to as 2D finite element/volume method (2D FEVM) model. The continuity equation is solved with the conforming, standard Galerkin FEM scheme and momentum equations with an upwind, cell‐centered finite volume method scheme, utilizing the water surface elevation and the line discharges as unknowns aligned in a staggered manner. The 2D FEVM model relies on neither Riemann solvers nor high‐resolution algorithms in order to serve as a simple numerical model. Water at a rest state is exactly preserved in the model. A fully explicit temporal integration is achieved in the model using an efficient approximate matrix inversion method. A series of test problems, containing three benchmark problems and three experiments of transcritical flows, are carried out to assess accuracy and versatility of the model. Copyright © 2014 John Wiley & Sons, Ltd.     

Neutrino Physics (Rapporteur talk)

Papers related to neutrino physics, submitted in the categories NU-EX (experimental results), NU-IN (methods, techniques, and instrumentation) and NU-TH (theory, model, and simulations) are reviewed with a brief introduction on the current understanding of neutrino masses and mixings.     

Development of 125Te synchrotron-radiation-based Mössbauer spectroscopy

The Mössbauer spectra of the 35.49 keV excited state of ¹²⁵Te were observed in the energy domain using synchrotron radiation for the first time. The obtained isomer shifts and Debye temperature agree with previous experiments. These results show that this method will be applicable to various compounds.     

Structural elucidation of rat biliary metabolites of corynoxeine and their quantification using LC‐MSn

Corynoxeine (COR) is one of 4 bioactive oxindole alkaloids in Uncaria species. In this work two phase I metabolites, namely 11‐hydroxycorynoxeine (M1) and 10‐hydroxycorynoxeine (M2), and two phase II metabolites, namely 11‐hydroxycorynoxeine 11‐O‐β‐d ‐glucuronide (M3) and 10‐hydroxycorynoxeine 10‐O‐β‐d ‐glucuronide (M4), were detected in rat bile after oral dose of COR (0.105 mmol/kg), by optimized high‐performance liquid chromatography–tandem mass spectrometry (LC‐MSⁿ) with electrospray ionization in positive ion mode. Structures of M1–4 were determined by LC‐MSⁿ, nuclear magnetic resonance, circular dichroism and high‐resolution MS spectra. COR and its metabolites in rat bile were quantified by LC‐MSⁿ. The LC‐MSⁿ quantification methods for COR and its metabolites yielded a linearity with coefficient of determination ≥0.995 from 5.0 × 10^?10 to 5.0 × 10^?7 m . The recoveries of stability tests varied from 96.80 to 103.10%. Accuracy ranged from 91.00 to 105.20%. Relative standard deviation for intra‐day and inter‐day assay was <5.0%. After the oral dose 0.14% of COR was detected in rat bile from 0 to 8 h, in which in total 97.8% COR biotransformed into M1–4. M1 and M2 yielded 48.1 and 49.7%, which successively glucuronidated to M3 and M4 at 47.2 and 43.8%, respectively. Copyright © 2014 John Wiley & Sons, Ltd.     

New analytical method for the study of metabolism of swertiamarin in rats after oral administration by UPLC‐TOF‐MS following DNPH derivatization

The metabolism of swertiamarin in vivo was studied by LC‐MS following 2,4‐dinitrophenylhydrazine derivatization. The ionization efficiency of the main metabolite erythrocentaurin was greatly enhanced by the new analytical method developed, and erythrocentaurin was successfully detected for the first time in rat plasma after oral administration of swertiamarin. Methyl 4‐formylbenzoate was used as the internal standard to quantify erythrocentaurin in rat plasma in negative mode by UPLC‐TOF‐MS, and it was found that erythrocentaurin reached the maximum mean plasma concentration of 425.8 ± 127.6 ng/mL at about 2 h after oral administration of swertiamarin at a dose of 200 mg/kg. A metabolic pathway of swertiamarin to erythrocentaurin was proposed. Swertiamarin is first hydrolyzed by bacterial β‐glucusidase to give the aglycone, which is readily converted to erythrocentaurin. The monoterpene compound swertiamarin was found to be metabolized to dihydroisocoumarin and alkaloid compounds in vivo, which may be responsible for the pharmacological effect of swertiamarin. The results may shed light on the clinical efficacy of swertiamarin and the new analytical method may assist in studies for the metabolism of other natural iridoids and secoiridoids in vivo. Copyright © 2015 John Wiley & Sons, Ltd.     

Supercritical water decomposition of polyethylene samples for the determination of their trace cadmium content.

A novel pretreatment method has been developed for determination of toxic metals in plastic materials by their decomposition under supercritical water conditions. Particularly, quantitative analysis of cadmium in polyethylene has been demonstrated using inductively coupled plasma atomic emission spectrometry combined with supercritical water treatment. All the cadmium in a polyethylene sample was obtained as an aqueous solution by the treatment with supercritical water containing 12.4% of hydrogen peroxide at 673 K. Although a complete recovery of the aqueous solution from the reactors has not yet been attained, we verified that the present method was effective and promising for quantitative analysis of trace amounts of hazardous metals in plastic materials.     

Probing the transmembrane potential of bacterial cells by voltage-sensitive dyes.

Fluorescent dyes have been widely employed as optical indicators of the membrane potential difference in cells, isolated organelles and lipid vesicles that are too small to make microelectrode measurements feasible. We describe here the application of a carbocyanine dye, 3,3'-dipropylthiodicarbocyanine iodide [DiS-C3-(5)], to monitor the transmembrane potential changes induced by a variation of the K+ concentration for the cells of Escherichia (E.) coli and photosynthetic bacterium Rhodospirillum (R.) rubrum. The cells were first incubated in buffers containing DiS-C3-(5) and K+ ions of various concentrations until the fluorescence intensity reached a constant value. Valinomycin was then added to the solution, which caused changes in the fluorescence intensity, depending on the K+ concentrations. The membrane potential is shown to have a linear relationship with the fluorescence intensity of DiS-C3-(5). The results demonstrate that the K+ concentrations inside intact cells are 4.6 mM and 5.3 mM for E. coli and R. rubrum, respectively. The diffusion potentials of K+ ions were determined using the Nernst equation over the range of -1.3 mV to 44 mV, corresponding to K+ concentrations of 5 mM -25 mM outside of the cells.