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We construct global weak solutions of the Euler equations in an infinite cylinder Π = { x ∈ R 3 | x h = (x 1 , x 2) , r = | x h | < 1 } for axisymmetric initial data without swirl when initial vorticity ω 0 = ω 0 θ e θ satisfies ω 0 θ / r ∈ L q for q ∈ [ 3 / 2 , 3). The solutions constructed are Hölder continuous for spatial variables in Π ‾ if in addition that ω 0 θ / r ∈ L s for s ∈ (3 , ∞) and unique if s = ∞. The proof is by a vanishing viscosity method. We show that the Navier-Stokes equations subject to the Neumann boundary condition is globally well-posed for axisymmetric data without swirl in L p for all p ∈ [ 3 , ∞). It is also shown that the energy dissipation tends to zero if ω 0 θ / r ∈ L q for q ∈ [ 3 / 2 , 2 ] , and Navier-Stokes flows converge to Euler flow in L 2 locally uniformly for t ∈ [ 0 , ∞) if additionally ω 0 θ / r ∈ L ∞. The L 2 -convergence in particular implies the energy equality for weak solutions. [ABSTRACT FROM AUTHOR]

• An anisotropic subgrid-scale (SGS) model for thermal field is proposed. • The model is extended from the anisotropy-resolving SGS model for velocity field. • A priori and a posteriori tests have been done for channel flow. • The proposed model can accurately predict the anisotropic SGS heat flux. • The variation of the anisotropy with Prandtl number can also be expressed. Some types of mixed subgrid-scale (SGS) models combining an isotropic eddy-viscosity model and a scale-similarity model can be used to effectively increase the accuracy of large eddy simulation (LES). For example, Abe (2013) recently proposed a stabilized mixed model, which can successfully express the anisotropy of the SGS stress, and remarkably improves the predictive performance for wall turbulence at coarse grid resolutions without sacrificing computational stability. In the present work, this approach is extended for thermal and scalar field modeling to express the anisotropy of SGS heat (scalar) flux. A priori tests using direct numerical simulation data demonstrated that the proposed model can accurately predict the anisotropic SGS heat flux in channel flow and its variation with Prandtl number in the range 0.1–2. Its effectiveness is also confirmed by a posteriori tests under flow conditions corresponding to those in the a priori tests. [ABSTRACT FROM AUTHOR]

Some types of mixed subgrid-scale (SGS) models combining an isotropic eddy-viscosity model and a scale-similarity model can be used to effectively improve the accuracy of large eddy simulation (LES) in predicting wall turbulence. Abe (2013) has recently proposed a stabilized mixed model that maintains its computational stability through a unique procedure that prevents the energy transfer between the grid-scale (GS) and SGS components induced by the scale-similarity term. At the same time, since this model can successfully predict the anisotropy of the SGS stress, the predictive performance, particularly at coarse grid resolutions, is remarkably improved in comparison with other mixed models. However, since the stabilized anisotropy-resolving SGS model includes a transport equation of the SGS turbulence energy, k SGS , containing a production term proportional to the square root of k SGS , its applicability to flows with both laminar and turbulent regions is not so high. This is because such a production term causes k SGS to self-reproduce. Consequently, the laminar–turbulent transition region predicted by this model depends on the inflow or initial condition of k SGS . To resolve these issues, in the present study, the mixed-timescale (MTS) SGS model proposed by Inagaki et al. (2005) is introduced into the stabilized mixed model as the isotropic eddy-viscosity part and the production term in the k SGS transport equation. In the MTS model, the SGS turbulence energy, k es , estimated by filtering the instantaneous flow field is used. Since the k es approaches zero by itself in the laminar flow region, the self-reproduction property brought about by using the conventional k SGS transport equation model is eliminated in this modified model. Therefore, this modification is expected to enhance the applicability of the model to flows with both laminar and turbulent regions. The model performance is tested in plane channel flows with different Reynolds numbers and in a backward-facing step flow. The results demonstrate that the proposed model successfully predicts a parabolic velocity profile under laminar flow conditions and reduces the dependence on the grid resolution to the same degree as the unmodified model by Abe (2013) for turbulent flow conditions. Moreover, it is shown that the present model is effective at transitional Reynolds numbers. Furthermore, the present model successfully provides accurate results for the backward-facing step flow with various grid resolutions. Thus, the proposed model is considered to be a refined anisotropy-resolving SGS model applicable to laminar, transitional, and turbulent flows. [ABSTRACT FROM AUTHOR]

Abstract: An improved subgrid-scale (SGS) model was proposed by combining an isotropic linear eddy-viscosity term with an extra anisotropic term. In the present study, primary attention was given to maintaining the computational stability while improving the predictive performance particularly for coarse grid resolution in the near-wall region. For the extra anisotropic term used for this purpose, the present study introduced a residual term after subtracting an eddy-viscosity form from the Bardina SGS-Reynolds-stress model [Bardina, J., Ferziger, J.H., Reynolds, W.C., 1980. Improved subgrid scale models for large eddy simulation. AIAA Paper 80-1357]. The resultant extra term yields no undesirable extra energy transfer between the grid-scale and SGS components that could cause numerical instability under coarse grid conditions. Therefore, this extra term is not expected to have any serious negative effects on the computational stability. In order to assess the performance, the proposed model was applied to the numerical simulation of fully-developed plane channel flows with various grid resolutions and at various Reynolds numbers. The computational results were considerably improved by the present SGS model and detailed investigations of the obtained results indicated the usefulness of the present model for engineering applications. [Copyright &y& Elsevier]

Abstract: In order to derive a possible path for developing a large eddy simulation (LES) applicable to high Reynolds-number complex turbulent flows, performance of an LES and a hybrid approach connecting LES with Reynolds-Averaged Navier–Stokes (RANS) modeling in the near-wall region (hybrid LES/RANS model, HLR model) was investigated. To discuss the model performance in detail, representative LES and HLR models were applied to a three-dimensional diffuser flow with massive separation. The HLR model gave considerable improvement of the prediction accuracy even with moderate grid resolution, while the LES returned earlier separation just downstream of the diffuser-inlet section. Furthermore, by processing the simulation data, useful knowledge was obtained for further development of this kind of turbulence model. In particular, it was elucidated that the non-linear eddy-viscosity model adopted in the HLR model was effective to reproduce the near-wall turbulence more correctly. This fact resulted in the suppression of an undesirable early separation. [ABSTRACT FROM AUTHOR]

Abstract: Sympathetic neurotransmitter neuropeptide Y (NPY) is associated with vascular remodelling, neointimal hyperplasia and atherosclerosis in experimental animal models and clinical studies. In order to study the role of sympathetic nerve-produced NPY in vascular diseases, transgenic mouse model overexpressing NPY in central and peripheral noradrenergic neurons under the dopamine-beta-hydroxylase (DBH) promoter was recently created (OE-NPYDBH mouse). This study aimed to examine the effect of NPY overexpression on arterial neointimal hyperplasia in an experimental model of vascular injury. Transgenic OE-NPYDBH mice and wildtype control mice of two different inbred strains (C57BL/6 and FVB/n) underwent a femoral artery surgery with a transluminar injury by a 0.38-mm guide wire insertion. Arteries were harvested 4 weeks from the surgery, and they were stained for basic morphology. Both strains of OE-NPYDBH mice, as compared with wildtype control mice, showed on average 50% greater formation of the neointima (P <0.01) and an increase in the medial area (P =0.05). The results suggest that moderately increased neuronal NPY causes the arteries to be more susceptible to femoral artery thickening after endothelial injury. The OE-NPYDBH mouse provides a novel tool to explore the role of NPY in the development of vascular disease related to metabolic disorders. [Copyright &y& Elsevier]

Numerical investigations are carried out for flow fields around flanged diffusers to develop small-type wind turbines under 1.5 kW. In the calculations, an advanced closure approximation is adopted, within the framework of non-linear eddy-viscosity modeling, which aims specifically at an improved representation of turbulence anisotropy. Comparison of the computed results with the corresponding experimental data shows that the present calculation has the capability of providing reasonable predictions for the present complex turbulent flows. Furthermore, by processing the computational results, the input-power coefficient is estimated under various conditions of diffuser opening angle and loading coefficient. It is shown that the performance of a flanged diffuser strongly depends on the loading coefficient as well as the opening angle because it greatly affects the nature of the separation appearing inside the diffuser. The present investigation suggests that the loading coefficient for the best performance of a flanged diffuser is considerably smaller than that for a bare wind turbine. [Copyright &y& Elsevier]

A comprehensive study of the organic chemistry and mineralogy of an ultracarbonaceous micrometeorite (UCAMM D05IB80) collected from near the Dome Fuji Station, Antarctica, was carried out to understand the genetic relationship among organic materials, silicates, and water. The micrometeorite is composed of a dense aggregate of ∼5 µm-sized hollow ellipsoidal organic material containing submicrometer-sized phases such as glass with embedded metal and sulfides (GEMS) and mineral grains. There is a wide area of organic material (∼15 × 15 μm) in its interior. Low-Ca pyroxene is much more abundant than olivine and shows various Mg/(Mg + Fe) ratios ranging from ∼1.0 to 0.78, which is common to previous works on UCAMMs. By contrast, GEMS grains in this UCAMM have unusual chemical compositions. They are depleted in both Mg and S, which suggests that these elements were leached out from the GEMS grains during very weak aqueous alteration, without the formation of phyllosilicates. The organic materials have two textures—smooth and globular with an irregular outline—and these are composed of imine, nitrile and/or aromatic nitrogen heterocycles, and amide. The ratio of nitrogen to carbon (N/C) in the smooth region of the organics is ∼0.15, which is five times higher than that of insoluble organic macromolecules in types 1 and 2 carbonaceous chondritic meteorites. In addition, the UCAMM organic materials are soluble in epoxy and are thus hydrophilic; this polar nature indicates that they are very primitive. The surface of the material is coated with an inorganic layer, a few nanometers thick, that consists of C, O, Si, S, and Fe. Sulfur is also contained in the interior, implying the presence of organosulfur moieties. There are no isotopic anomalies of D, 13 C, or 15 N in the organic material. Interstellar photochemistry alone would not be sufficient to explain the N/C ratio of the UCAMM organics; therefore, we suggest that a very small amount of fluid on a comet must have been necessary for the formation of the UCAMM. The GEMS grains depleted in Mg and S in the UCAMM prove a very weak degree of aqueous alteration; weaker than that of carbonaceous chondrites. Short-duration weak alteration probably caused by planetesimal shock locally melted cometary ice grains and released water that dissolved the organics; the fluid would likely have not mobilized because of the very low thermal conductivity of the porous icy body. This event allowed the formation of the large organic puddle of the UCAMM, as well as organic matter sulfurization, formation of thin membrane-like layers of minerals, and deformation of organic nanoglobules. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a wind turbine system that consists of a diffuser shroud with a broad-ring flange at the exit periphery and a wind turbine inside it. The flanged-diffuser shroud plays a role of a device for collecting and accelerating the approaching wind. Emphasis is placed on positioning the flange at the exit of a diffuser shroud. Namely, the flange generates a low-pressure region in the exit neighborhood of the diffuser by vortex formation and draws more mass flow to the wind turbine inside the diffuser shroud. To obtain a higher power output of the shrouded wind turbine, we have examined the optimal form of the flanged diffuser, such as the diffuser open angle, flange height, hub ratio, centerbody length, inlet shroud shape and so on. As a result, a shrouded wind turbine equipped with a flanged diffuser has been developed, and demonstrated power augmentation for a given turbine diameter and wind speed by a factor of about 4–5 compared to a standard (bare) wind turbine. In a field experiment using a prototype wind turbine with a flanged diffuser shroud, the output performance was as expected and equalled that of the wind tunnel experiment. [Copyright &y& Elsevier]

Where is the place which should be helped in a patient with congestive heart failure? The answer may be contraction of the heart. At Tohoku University, development research of ”the artificial myocardium” has been conducted, using a ball screw type electromagnetic motor. Furthermore, super-miniaturization is being attempted at present. Thus, a system with shape memory alloy is being developed. The cooling speed problem was solved by the application of the Peltier element. A drive at a speed equal to that of a heartbeat was realized by the application of this system. At present, a ventricular assist device is used for patients waiting for a heart transplant in Japan. An air driven type system disturbs a patient’s QOL remarkably because it is connected to the drive device. With our concept, energy is provided by using the electromagnetic force from outside of the body by the use of transcutaneous energy transmission system. Magnetic shielding by amorphous fibers was used at Tohoku University to improve the total efficiency. A natural heart can alter the cardiac output corresponding to the demand. Artificial internal organs must participate in the system of the living body, too. Tohoku University has developed a resistance based artificial heart control algorithm, which simulated a baroreflex system to cope with every demand. Nano level sensing equipment is now under development at Tohoku University. At present, development is being conducted aiming at an ”intelligent artificial myocardium”. [Copyright &y& Elsevier]

The “Pockemon shock” is the most famous accident in the history of the broadcasting industry in Japan. Based on the experiences of this unfortunate accident from famous animation program “Pocket Monster”, this study focused on the psychology and psychosomatics of the patients. A head-mounted display was used as the three-dimensional image presentation device and “Descent”, a free software shooting game, was used as the software. Ten healthy adult male volunteers were used in this experiment after obtaining their informed consent. The oxygen metabolic change in the anterior lobe of the brain was measured by near infrared spectroscopy and recorded on an electrocardiogram. The mental scaling tendency of the object was analyzed using the type A behavior pattern and the hostility scaling. The Cook and Medley hostility (HO) scale from the Minnesota multiphasic personality inventory (MMPI) was also used in this experiment. From this scaling methodology, the paranoid scale, cynicism scale, lie scale, social support quality and social support quantity were calculated. All measured time series data were kept in the normal range, and no fatal arrhythmia or epilepsy were observed during experiments. In some cases, the brain oxygen metabolism may completely differ for the objects of Type A and Type B behavior patterns. On the whole, correlation did not become significant in type A scaling and hostility scaling. In a comparison of the percent changes of the HF in HRV with lie scaling, significant negative correlation was observed. The social support quantity was calculated from Cook and Medley, and significant negative correlations were observed with percent changes of LF/HF in HRV. The lie scale and social support quantity are opposite scaling. The sympathetic nervous system and parasympathetic nervous system have an opposite function also. Therefore, our results showed an interesting phenomenon, when considering the relationship between the autonomic function and the pathophysiological reaction to the audiovisual stimulations. As for the photo sensitive epilepsy, it was reported to be only 5–10% for all patients. Therefore, 90% or more of the cause could not be determined in patients who started a morbid response. The results in this study suggest that the autonomic function was connected to the mental tendency of the objects. By examining such directivity, it is expected that subjects, which show morbid reaction to an audiovisual stimulation, can be screened beforehand. [Copyright &y& Elsevier]