Glutamine uptake at the blood-brain barrier is mediated by N-system transport

The aim of this study was to determine the effect of angiotensin II (AII) on tyrosine hydroxylase (TOH) activity and phosphorylation in bovine adrenal chromaffin cells (BACCs). We report here that stimulation of BACCs with AII (100 nM) produced a significant increase in both TOH activity and phosphorylation over a period of 10 min. The increase in TOH activity was receptor-mediated. Tryptic phosphopeptide analysis by HPLC revealed that AII stimulated an increase in phosphorylation of three sites on TOH, Ser19, Ser31, and Ser40, with the largest increase being observed for Ser31 phosphorylation. Pretreatment of the cells with the protein kinase C inhibitor Ro 31-8220 (10 microM, 15 min) did not affect TOH activity or phosphorylation produced by AII. The inhibitor also did not affect the TOH activity or Ser40 phosphorylation produced by forskolin (10 microM, 10 min). In contrast, Ro 31-8220 fully inhibited the TOH activation as well as Ser31 and Ser40 phosphorylation of TOH produced by phorbol 12,13-dibutyrate (500 nM, 10 min). Removal of extracellular Ca2+ from the incubation medium inhibited the AII-induced TOH activity by 50% and significantly blocked Ser19 and Ser31 phosphorylation but did not affect Ser40 phosphorylation in response to AII. These results indicate that AII activates a complex and perhaps novel signaling pathway leading to the phosphorylation and activation of TOH. The TOH activation by AII appears to be partially independent of Ser40 phosphorylation, suggesting a potentially important role for Ser31 phosphorylation.     

Influence of the deposition conditions on the crystallographic structure and the GaAs refraction index

An experimental study of the influence of deposition conditions of GaAs thin films growth, by radio frequency sputtering method, on the structure and the refraction index has been performed. The X-ray diffraction and spectrophotometer results, with different deposition conditions, are reported.The refraction index depends on the structure, which also depends on four deposition parameters, namely, the self-bias voltage, V_p, the argon pressure, P_Ar, the target-to-substrate distance, d, and the substrate temperature, T_s. Hence, it has been observed that, the index refraction of the films decreases with V_p and T_s and increases essentially with P_Ar.     

1D/2D Cobalt‐Based Nanohybrids as Electrocatalysts for Hydrogen Generation

The synergistic effects derived from optimizing the chemical and structural features of electrocatalysts permit them to attain remarkable activity and stability. Herein, 1D/2D cobalt‐based nanohybrid (CoNH) electrodes are developed; the structural design consists of Co₃O₄ electrospun nanoribbons (NRs) deposited onto a carbon fiber paper substrate where Co₃O₄ nanosheets are subsequently grown via an electrodeposition step and UV/ozone treatment. The content of noncovalently functionalized carbon nanotubes within the Co₃O₄ NRs is first tuned to enhance their charge transfer properties and mechanical stability. The electrocatalytic activity of the electrodes is further improved by a phosphorus modification of the 1D NRs, resulting in the formation of NaCoPO₄. The optimized 1D/2D CoNH electrode, i.e., ED‐0.09 wt% fCNTs/P‐CoNHs, displays a similar performance to that of platinum in 0.25 m Na₂S/0.35 m Na₂SO₃ (Tafel slope ≈102 mV dec^?1 for the former and ≈96 mV dec^?1 for the latter) and outstanding stability for up to 48 h. The versatility and high activity of this electrode is also demonstrated according to tests in a conventional water splitting system (cell voltage 1.55V, to produce 10 mA cm^?2) and a solar‐driven electrolyzer (1 m KOH).     

Experimental and theoretical investigation of non-isothermal transfer in hygroscopic building materials

In this paper a modified two-dimensional Luikov model for evaluating the non-isothermal moisture migration in porous building materials was proposed. The coupled heat and moisture transfer problem was modeled. Vapor content and temperature were chosen as the principal driving potentials. The coupled equations were solved by a numerical method, which consists of a finite difference technique with a fully implicit scheme in time. Two validation experiments were developed in this study. The evolution of transient moisture distributions in both one-dimensional and two-dimensional cases was measured. A comparison between experimental results and those obtained by the numerical model proves that they are fully consistent with each other. The modified model can be integrated into a whole building heat, air and moisture transfer model.     

Predictive direct torque control with reduced ripples for induction motor drive based on T‐S fuzzy speed controller

Finite‐state model predictive control (FS‐MPC) has been widely used for controlling power converters and electric drives. Predictive torque control strategy (PTC) evaluates flux and torque in a cost function to generate an optimal inverter switching state in a sampling period. However, the existing PTC method relies on a traditional proportional‐integral (PI) controller in the external loop for speed regulation. Consequently, the torque reference may not be generated properly, especially when a sudden variation of load or inertia takes place. This paper proposes an enhanced predictive torque control scheme. A Takagi‐Sugeno fuzzy logic controller replaces PI in the external loop for speed regulation. Besides, the proposed controller generates a proper torque reference since it plays an important role in cost function design. This improvement ensures accurate tracking and robust control against different uncertainties. The effectiveness of the presented algorithms is investigated by simulation and experimental validation using MATLAB/Simulink with dSpace 1104 real‐time interface.     

Stability of an Axially Moving Viscoelastic Beam

In this paper, we consider a viscoelastic flexible structure modeled as an Euler-Bernoulli beam. The beam is moving in the direction of its axis. This is one of the main features of this work. We will be dealing with variable intervals of integration and therefore the standard computation using differentiation under the integral sign is no longer valid. The boundary conditions are of ‘cantilever’ type: there is no displacement at one end and the other end is free. In fact, it is subject to a nonlinear force acting there. We prove that when the velocity of the beam is smaller than a critical value, the dissipation produced by the viscoelastic material is sufficient to suppress the transversal vibrations that occur during the axial motion of the beam. The rate of decay is shown to be exponential.     

Pool Evaporation – Experimental Data Collection and Modeling

When handling flammable or toxic liquids or liquefied gases, the occurrence of a leakage and formation of a liquid pool is a scenario to be considered for risk assessment. Several models are available for estimating the evaporating mass flow, but only few experimental data exist for validation purposes. Evaporation experiments, with vapor pressures up to 0.94 bar and with different substances in basins of varying diameter, were carried out, mainly on open‐air test sites with different topographies, but also in enclosed spaces. Based on these new data, a validation of existing pool evaporation models was carried out and eventually led to the new formulation of an evaporation model, which is also presented here.     

Icosahedrons microstrip antenna network architecture proposal for new USS telecommunication subsystem

The paper presents a new antenna network subsystem architecture developed for application on board wireless communication subsystem. Founded research work results demonstrate the success of mathematical modeling and simulation of the proposed Icosahedrons Microstrip Antenna Network Architecture. Antenna elements are simulated, prototyped and tested. The Icosahedrons Microstrip Antenna Network is developed to meet the visibility requirements during inter small USS satellite radio communications.     

Two-dimensional hygrothermal transfer in porous building materials

A two-dimensional mathematical model for evaluating the simultaneous heat and moisture migration in porous building materials was proposed. Vapor content and temperature were chosen as the principal driving potentials. The numerical solution was based on the control volume finite difference technique with fully implicit scheme in time. Two validation experiments were developed in this study. The evolution of transient moisture distributions in both one-dimensional and two-dimensional cases was measured. A comparison between experimental results and those obtained by the numerical model proves that they are fully consistent with each other. The model can be easily integrated into a whole building heat, air and moisture transfer model. Another main advantage of the present numerical method lies in the fact that the required moisture transport properties are comparatively simple and easy to determine.