Liquid and gas distribution in trickle-bed reactors was investigated in a column packed with commercial catalyst particles. Distilled water and air were used as liquid and gas phases, respectively. Surface tension effects were tested by adding detergent to the water. The influence of both liquid load and gas load on the distribution was studied. Flow rates corresponded to those used in industrial hydroprocessing units. It was found that the liquid distribution at a given liquid load can be improved considerably by either increasing the liquid load or flooding the column in advance. The gas distribution is shown to be correlated inversely with the liquid distribution. Use of a large-particle top layer results in an improved distribution.

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The need for fast and comprehensive characterization of biocatalysts has pushed the development of new screening platforms based on microfluidics, capable of monitoring several parameters simultaneously, with new configurations of liquid handling, sample treatment and sensing. Modular microfluidics allows the integration of these newly developed approaches in a more flexible way towards increasing applicability of the microfluidic chips to different types of biocatalysts and reactions. A highly relevant operation in such a system is biocatalyst inactivation, which can enable the precise control of reaction time by avoiding the continuation of the reaction in another module or connecting tubes. Such control is important when different modules of reactors and/or sensing units are used and changed frequently. Here we describe the development, characterization and application of a module for rapid enzyme inactivation. The thermal inactivation platform developed is compared with a standard benchtop ThermoMixer in terms of inactivation efficiency for glucose oxidase and catalase. A higher activity loss was observed for enzyme inactivation under flow conditions (inactivation achieved at 120 s residence time at 338 K and 20 s residence time at 353 K) which indicated a high heat transfer to the fluid under dynamic conditions. Moreover, partial deactivation of the enzymes was observed for the continuous thermal inactivation module, when activity measurements were performed after 1 and 2 days following inactivation. The thermal inactivation unit presented can be easily integrated into modular microfluidic platforms and can be a useful addition for enzyme characterization and screening.

--A simple, easy to manufacture and high efficient integrated planar transformer design approach for primary parallel isolated boost converters is presented. Utilizing the same phase flux flow, transformers are integrated, reducing the total ferrite volume and core loss for the same peak flux density. Number of turns is minimized for easy manufacturing by cascade placement of planar cores increasing the effective crosssectional area. AC losses in the windings as well as the leakage inductance of the transformer are kept low by extensive interleaving of the primary and secondary turns. The idea of transformer integration is further extended to multiple primary power stages using modular geometry of the planar core, further reducing the core loss and allowing a higher power density. To verify the validity of the design approach, a 4-kW prototype converter with two primary power stages is implemented for a fuel cell fed battery charger application with 50-110 V input and 65-105 V output. Input inductors are coupled for current sharing, eliminating the use of current sharing transformers. An efficiency of 94% is achieved during nominal operating condition where the input is 70-V and the output is 84-V.Index Terms-planar integrated magnetics, coupled inductor, isolated boost converter, fuel cell.