High temperature direct double side cooled inverter module for hybrid electric vehicle application

In this paper a novel approach to the design and fabrication of a high temperature inverter module for hybrid electrical vehicles is presented. Firstly, SiC power electronic devices are considered in place of the conventional Si devices. Use of SiC raises the maximum practical operating junction temperature to well over 200°C, giving much greater thermal headroom between the chips and the coolant. In the first fabrication, a SiC Schottky barrier diode (SBD) replaces the Si pin diode and is paired with a Si-IGBT. Secondly, double-sided cooling is employed, in which the semiconductor chips are sandwiched between two substrate tiles. The tiles provide electrical connections to the top and the bottom of the chips, thus replacing the conventional wire bonded interconnect. Each tile assembly supports two IGBTs and two SBDs in a half-bridge configuration. Both sides of the assembly are cooled directly using a high-performance liquid impingement system. Specific features of the design ensure that thermo-mechanical stresses are controlled so as to achieve long thermal cycling life. A prototype 10 kW inverter module is described incorporating three half-bridge sandwich assemblies, gate drives, dc-link capacitance and two heat-exchangers. This achieves a volumetric power density of 30W/cm3.

Magnetic field configurations of radio jets in the double source of radio galaxy

As an improvement of resolution of observations, more and more radio galaxies with radiojets have been identified and many fine structures in the radio jets yielded. In the presentpaper, the two-dimensional magnetohydrodynamical theory is applied to the analysis of themagnetic field configurations in the radio jefs. Two-dimensional results not only are con-sistent theoretically, but also explain the fine structures of observations. One of the theo-retical models is discussed in detail, and is in good agreement as compared with the observedradio jets of NGC6251. The results of the present paper also show that the magneticfields in the radio jets are mainly longitudinal ones and associate with the double sources ofQSOs if the magnetic field of the central object is stronger; the fields in the radio jets aremainly transverse ones and associate with the double sources of radio galaxies if the fieldof the central object is weaker. The magnetic field has great influence on the morphol-ogy and dynamic process.

The magnetic jet theory of double source in radio galaxy

The two-dimensional accelerating theory about solar wind is applied to the study of theaccelerating process of jet beam in the radio galaxy. The flowing features are given with theanalytic method, and the basic flow is along the direction of the jet beam. The mechanism ofacceleration from subsonic to supersonic flow is discussed. At the same time, some fine struc-tures about the double sources in the radio galaxy are explained.

Randomized, double-blind, placebo-controled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

Trial registration number: CTRN12611000543987

Experimental Study on Bénard-Marangoni Convection in Double Immiscible Liquid Layer

An experimental investigation of Bénard-Marangoni convection has been performed in double immiscible liquid layers of rectangular configuration on the ground. The two kinds of liquid are 10cst silicon oil and FC-70 respectively. The size of rectangular chamber is 100mm×40mm in horizontal cross-section. The evolution processes of convection are observed in the differential thickness ratio of two liquid layers. The critical temperature difference was measured via the detections of fluid convection by a particle image velocimetry (PIV) in the vertical cross-section of the liquid layer. The critical temperature difference or the critical Marangoni number was given. And the influence of the thickness ratio of two liquid layers on the convection instability was discussed. The evolution processes of patterns and temperature distributions on the interface are displayed by using thermal liquid crystal. The velocity distributions on the interface were also obtained. In comparison with the thermocapillary effect, the effect of buoyancy convection will relatively increase when the depth of the liquid layer increases. Because of the coupling of buoyancy and thermocapillary effect, the convection instability is much more complex than that in the microgravity environment. And the critical convection depends on the change of the thickness of liquid layers and also the change of thickness ratio of two liquid layers.

Numerical Partition of Energy Absorption of Foam-filled Top-Hat and Double-Hat Sections

The interaction effect, i.e., the contribution of each component to the total energy absorption of an axially crushed foam-filled hat section was investigated quantitatively via numerical simulation. The FE results were first verified by experimental work of aluminum foam-filled top-hat and double-hat sections, then the contribution of foam-fillers and that of hat sections to the overall energy absorption were quantitatively obtained, respectively. When foam-filled, increase in energy absorption was found both in hat section component and foam-filler component, whereas the latter contributes predominantly to the interaction effect.

Analysis of Behaviors of Shock Focusing in the Inner Cavities of Double Wedge and Cone

The mechanisms of shock focusing in inner cavities of double wedge and cone are compared with that of traditional curved-surface shock focusing. The results show that there are many high temperature regions just behind shock surface which appear in two place alternately, one is near the surface of wall and the other is near the centerline. Also, changes in temperature, pressure, energy and power of the high temperature regions were analyzed and the results show that energy and power per unit volume increase, but total energy and power in the high temperature regions decrease during the process of shock moving forward the apex of double wedge or cone.