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Curcumin, the main bioactive component of turmeric, has a wild range of beneficial effects on central nervous diseases, including anti-Alzheimer's disease, antioxidant stress, and anti-inflammation. Currently, it has been demonstrated the anti-epileptic potential. However, curcumin has poor water solubility, high sensitivity to light and heat, and low absorption, which results in low bioavailability and greatly limits the clinical application of curcumin, as well as the elusive effects in anti-epileptic treatment. This study aimed to develop a curcumin hydroxypropyl-β-cyclodextrin inclusion complex (CUR-HP-β-CD) to improve its bioavailability and facilitate its potential development as an anti-epileptic drug. The CUR-HP-β-CD was generated by the solvent evaporation method, which has efficient entrapment, high solubility, and facilitated bioavailability and brain distribution. The solubility of the CUR-HP-β-CD was 63.5, 60.1, and 52.9 times that of the unformulated curcumin in H2O, HCl (pH 1.2), and PBS (pH 6.8), respectively. The bioavailability of CUR-HP-β-CD is improved 2.8 times and 38.7 folds higher brain concentrations. Moreover, the therapeutic anti-epileptic effects of CUR-HP-β-CD were much more effective in pentylenetetrazol (PTZ)-induced zebrafish and mouse models. This study showed a simple and reproducible strategy to effectively improve the bioavailability and therapeutic effects of curcumin, which could be potentially used in epilepsy treatment. [ABSTRACT FROM AUTHOR]

A two-level variational multiscale meshless local Petrov-Galerkin (VMS-MLPG) method is presented for incompressible Navier-Stokes equations based on two local Gauss integrations which effectively replace a unit operator (first level) and an orthogonal project operator (second level). The present VMS-MLPG method allows arbitrary combinations of interpolation functions for the velocity and pressure fields, specifically the equal-order interpolations that are easy to implement and satisfy the Babuska-Breezi (B-B) condition. The prediction accuracy and the numerical stability of the proposed method for the lid-driven cavity flow and the backward facing step flow problems are analyzed and validated by comparing with the SUMLPG method and the benchmark solutions. It is shown that the present VMS-MLPG method can guarantee the numerical stability and obtain the reasonable solutions for incompressible Navier-Stokes equation. [ABSTRACT FROM AUTHOR]

The method of successive under-relaxation (SUR) is an effective way for numerically solving a nonlinear system of equations governing the fluid flow and heat transfer, resulting in stable convergence. So far, there is not any doable applied method to determine the best relaxation factor of SUR. In this article, the interrelation among the diffusion term, the convection term and the under-relaxation term is regarded as the key to calculate the under-relaxation factor. Then, the self-adaptive under-relaxation factor strategy is proposed. The test calculation of two typical problems, lid-driven cavity flow, and flow over a backward-facing step is carried out based on the proposed self-adaptive under-relaxation strategy. It is proved that the present method is efficient and robust compared to the fixed under-relaxation factor method. [ABSTRACT FROM AUTHOR]

AbstractThe ridged V-shaped dimple (RVD) is proposed to improve the thermal-hydraulic performance of the dimpled cooling passage by generating a ridge at the junction of the spherical dimple and V-shaped dimple. The impacts of arrangements (staggered, inline), geometric parameters (the length l/D of RVD leg, the angle α between two legs, the spacing s/D between the spherical dimple and V-shaped dimple in RVD, the depth-to-diameter ratio of dimple), and Reynolds number (Re = 8,500-50,000) on the thermal-hydraulic performance of RVD are investigated through numerical simulations. Results demonstrate that RVD significantly improves thermal-hydraulic performance by forming larger and stronger longitudinal vortexes and disrupting the boundary layer. The inline RVD has a higher thermal-hydraulic performance compared to the staggered RVD due to the stronger disturbance. Moreover, the RVD is appropriate for enhancing the thermal-hydraulic performance of deeper dimples, case 0.3-0.1 has the largest PEC (1.38-1.50) compared to other dimpled cases, and it achieves a 10.50%-18.18% increase over the corresponding typical VD. Finally, the correlations for Nu/Nu0 and f/f0 of inline RVD are proposed based on the numerical results, and the deviations between the predicted results and the simulated results are 10% for Nu/Nu0 and f/f0. [ABSTRACT FROM AUTHOR]

The numerical oscillation will occur in convection-diffusion equations as special linear problems at large Peclet number (Pe) in the numerical calculation process. In this article, we propose a new definition of the stability parameter in streamline upwind meshless Petrov-Galerkin (SUMLPG) method. The most important feature of the proposed method is that the test function in the stabilization term is taken into the differential operator-like form The stability parameter is designed to adjust the convection strength to achieve accurate and stable numerical solutions. Several classical examples are adopted to assessment the accuracy and stability of the proposed stability parameter. It is proven that the proposed method is especially suitable for convection-diffusion problems with large Pe. [ABSTRACT FROM AUTHOR]

A meshless local Petrov–Galerkin (MLPG) approach based on the streamline upwind (SU) idea and the variational multiscale (VMS) concept, called as VMS-SUMLPG method, is herein proposed to solve the convection-dominated problems. In the present VMS-SUMLPG method, the streamline upwind is constructed in the test function to solve the non-self-adjoint matrix. Meanwhile, the VMS concept as a stability term is adopted to alleviate the numerical instability such as spurious oscillations, overshoots, and undershoots. Its numerical accuracy and stability are validated by comparing with the streamline upwind Petrov–Galerkin (SUMLPG) method and the finite volume method with high-order difference schemes for two classical convection-dominated problems at the Peclet number ranging from 106to 108. It is shown that the numerical solutions of the present VMS-SUMLPG method are accuracy, smoothness, and stability. [ABSTRACT FROM PUBLISHER]

A physically consistent difference scheme is proposed to discretize the convection–diffusion equation in this paper. The interface variables of control volume are calculated by the interpolation of the discretized convection–diffusion equation rather than the direct interpolation with neighbor nodes in the direction perpendicular to the interface. In the new scheme, all the nodes of parallel and normal to the interface are involved, which means that the influence of cross-stream fluxes is considered. Obviously, the proposed interpolation scheme is full of physical meaning and better than the traditional convective interpolation schemes. Two simulations of typical benchmark problems, lid-driven cavity flow in square cavity and flow over a backward-facing step, are carried out with this scheme and some traditional schemes to prove the advantages of the proposed scheme. [ABSTRACT FROM AUTHOR]

When people in a society want to make inference about some parameter, each person may want to use data collected by other people. Information (data) exchange in social networks is usually costly, so to make reliable statistical decisions, people need to weigh the benefits and costs of information acquisition. Conflicts of interests and coordination problems will arise in the process. Classical statistics does not consider people’s incentives and interactions in the data-collection process. To address this imperfection, this work explores multi-agent Bayesian inference problems with a game theoretic social network model. Motivated by our interest in aggregate inference at the societal level, we propose a new concept,finite population learning, to address whether with high probability, a large fraction of people in a given finite population network can make “good” inference. Serving as a foundation, this concept enables us to study the long run trend of aggregate inference quality as population grows. Supplementary materials for this article are available online. [ABSTRACT FROM AUTHOR]

The microstructures and defects in SrSmAlO4-based microwave dielectric ceramics were investigated by TEM. The layer sequence defect was observed in Sm-rich SrSmAlO4ceramics. The other type of intergrowth defect was observed in Sr/Ti co-substituted SrSmAlO4ceramics, where the inhomogeneity of local area also appeared. The dislocation and secondary phase were present in Ti substituted (Sr0.3Ca0.7)SmAlO4ceramics. In addition, the secondary phases were observed in the SrSmAlO4ceramic with ZrO2pollution and that was sintered at the elevated temperature. All these defects lead to an increase in extrinsic dielectric loss, which should be prevented by microstructural engineering. [ABSTRACT FROM PUBLISHER]

This article presents a 2-D numerical simulation on nucleate boiling using the VOSET method. Heat transfer through a liquid microlayer around a three-phase contact point is incorporated by a multiscale system method. A temperature interpolation method is presented for solving temperature field in cells containing liquid-vapor interface. Apart from the single-bubble model, computations are carried out for two-bubble and bubble merger models. Heat fluxes predicted by simulation are compared with experimental correlations and good agreement is obtained. In addition, simulation results of bubble's behavior also verify some boiling mechanisms. [ABSTRACT FROM AUTHOR]

Passive cooling schemes, such as natural convection, are the most reliable heat dissipation apprpaches for electronic equipment. Some times, the highest temperature of the printed circuit board (PCB), rather than the highest of chips, is very much concern because of some technological reasons. In order to reduce the maximum PCB temperature, this article analyze the PCB temperature distribution by multiscale simulation. A top-to-down approach is adopted in order to reveal the details of temperature distribution of some interested local position. In the top-to-down approach, the system level simulation by a not-too-fine grid system is the key to obtain a reliable solution. In order to reach such a goal each component of the PCB should be reasonably simplified. The thermal analysis method is proposed to simplify the components, and the implementation details are provided for three types of components. In the companion article, the settlement of boundary conditions from the data of system level simulation and several improvements in heat transfer by numerical simulation will be presented. [ABSTRACT FROM PUBLISHER]

In the companion article (Part I), simplified compact model of components in a system level model was established based on heat transfer path and thermal resistance network analysis. In this article, component level simulation and lead level simulation was conducted by assiging the boundary conditions from the data of the higher level simulation, and effects of different boundary conditions on numerical accuracy and stability are studied. Comparison shows that multiscale thermal modeling methodology can save 87% of the total computation time compared with full simulation with a fine grid system, and can greatly improve the resolution of the calculation result. Mainly based on the multiscale simulation five improvements for the reduction of the maximum PCB temperature are proposed. This article also provides an example that by a careful numerical thermal design, a passive cooling mode can sometimes meet the cooling requirement of a PCB with high power input in some extent. [ABSTRACT FROM PUBLISHER]

Passive cooling schemes, such as natural convection, are the most safe heat dissipation mode of electronic equipment. Some times the highest temperature of the PCB, rather than the highest of chips, is very much a concern due to technological reasons. In order to reduce the maximum PCB temperature, this article discusses various improvement methods via numerical simulation. These include optimization of fin number of heat sink, structure improvement of sun shield, and creation of insulation cavity in the base plate of heat sink. Taking the PCB of an RBS as an example, numerical simulation results show that by integrating these methods the maximum PCB temperature can be appreciably reduced. This article provides an example that by using a careful numerical thermal design, a passive cooling mode can sometimes meet the cooling requirement of a PCB with high power input in some extent. [ABSTRACT FROM AUTHOR]

For periodic fully developed fluid flow and heat transfer problems, it is sufficient to confine attention to a single cycle. The temperature periodic conditions at the computational domain inlet/exit for fluid temperature can be implemented by two methods: either by extending the computational domain by several control volumes and replacing the field data at the domain inlet and outlet by each other, or by using linear interpolation while restricting the computation within one module. By carefully examining the numerical solutions of the fluid streamwise bulk temperature obtained from the two methods, it is found that at the fluid bulk temperature varies abruptly at the domain exit. A comprehensive analysis reveals that this abnormal phenomenon is caused by the fact that the domain exit fluid bulk temperature is actually not updated with iteration. A remedy is proposed: The domain exit bulk temperature is updated by an upwind-based interpolation method. Numerical examples show that the second-order interpolation method is feasible and reliable. [ABSTRACT FROM AUTHOR]