A critical review of cooling techniques in proton exchange membrane fuel cell stacks

Conversion of hydrocarbons and alcohols for fuel cells

Fuel conversion to hydrogen is an important part of most fuel cell systems. The paper describes the available technologies for conversion of hydrocarbons and alcohols. The endothermic steam reforming catalysts
 and processes as well as autothermal reforming are proven technologies. Recent developments include catalytic partial oxidation. The integration of the fuel processing with the fuel cell represents a task with requirements
 depending on each type of fuel cell and application. The automotive use of fuel cells is at present a special challenge. The optimum fuel for stationary plants
 is natural gas (if available), whereas light naphtha appears to be the choice for automotive use.

Since the beginning of railway electrification, power quality has been a main problem in railway networks because of their special characteristics. Many ways of power quality improvement have been investigated and applied to ac and dc traction systems through railway electrification history. This paper presents a perspective on power quality issues through railway electrification development and investigates the necessity of power quality and system requirements for appropriate power quality. Compensation strategies are classified and compared. This aims to provide a comprehensive perspective of the power quality issue in railway power/distribution networks for researchers and engineers working on railway electrification. Less than 100 research articles are referenced for researchers to obtain good background information.

Power Quality Issues in Railway Electrification: A Comprehensive Perspective

Review of methanol reforming-Cu-based catalysts, surface reaction mechanisms, and reaction schemes

Der Drucksensor (6) einer Drucksensorbaugruppe ist durch einen Durchgangskanal (22) eines Dichtkissens (20) und einen dichtend durch eine Trennwand (28) hindurchgefuhrten Rohrstutzen (54) mit dem Feuchtraum (32) in einer Fahrzeugture verbunden. Das Gehause (2) der Sensorbaugruppe befindet sich im Trockenraum (30). Sowohl das Innere des Gehauses (2) als auch der Trockenraum (30) sind gegenuber dem Inneren des Rohrstutzens abgedichtet, so das an die Wasserdichtigkeit des Gehauses (2), in dem eine Leiterplatte (4) und elektronische Komponenten aufgenommen sind, geringe Anforderungen gestellt sind.

Sensorbaugruppe mit einem an einer wand montierbaren gehäuse

Low-cost air-cooled PEFC stacks

Single-orientation, c -oriented thin films with high critical transport current ( j c > 5×10 5 A/cm 2 at 77 K) were deposited on sapphire with YSZ buffer layers. High-resolution transmission electron microscopy was used to image the various interfaces. At the YSZ-YBa 2 Cu 3 O 7 interface, a BaZrO 3 intermediate layer of 3–5 nm thickness was observed. The intermediate layer was highly oriented and grew on the single-crystalline buffer layer via the diffusion of Ba into the YSZ. The Al 2 O 3 -YSZ interface was planar on the atomic scale, and local mechanical strain fields at the interface being due to the mismatch between (012)-Al 2 O 3 and (220)-YSZ lattice planes were found.

Interface analysis of epitaxial YBa2Cu3O7 thin films deposited on sapphire (Al2O3) with YSZ buffer layers

As the connector industry moves towards the use of smaller and smaller contact designs, achievable contact normal forces have been reduced to levels below what has been typically used previously in connector applications. Therefore, improving the ability to predict and analyze the mechanical and electrical performance of these lower force contact interfaces is becoming increasingly important. This paper will illustrate further development and experimental verification of a new method to simulate elastic/plastic contact between two multi-layered nonconforming rough surfaces. This new approach involves using six scale independent parameters to statistically model two 3-dimensional multilayered surfaces coming into contact. The mechanical and electrical response characteristics of all the layer materials, as well as frictional behavior at the contacting asperity surfaces, are taken into account as pressure is applied between the surfaces and the a-spot distribution is formed. The mechanical and electrical contact performance of the resulting interface are calculated and visualized in 3 dimensions. The model has been extended and applied to contacts with varying surface finish materials and surface topology characteristics. These results are then compared to experimental data generated from samples with comparable finishes.

Extension and Experimental Verification of a New 'First Contact' Method to Model Performance of Multilayer Contact Interfaces

The present invention relates to a method for determining the distance between an airbag unit (22) and the torso of a person (4) who is fastened in a vehicle seat (2) by a seat belt (6) passing over her shoulder. This method comprises measuring the length by which the seat belt (6) is unwound relative to the reference position of a take-up mechanism (8), and forwarding the measured length to a calculation unit (21) where the distance is calculated while accounting for other optional parameters.

Verfahren zum Bestimmen des Abstandes zwischen einer angegurteten Person und einer Airbag-Einheit sowie Gurtabwickelmeßvorrichtung zur Verwendung für das Verfahren

Harald Schmidt

Papers

Sensorbaugruppe mit einem an einer wand montierbaren gehäuse

Low-cost air-cooled PEFC stacks

Interface analysis of epitaxial YBa2Cu3O7 thin films deposited on sapphire (Al2O3) with YSZ buffer layers

Extension and Experimental Verification of a New 'First Contact' Method to Model Performance of Multilayer Contact Interfaces

Verfahren zum Bestimmen des Abstandes zwischen einer angegurteten Person und einer Airbag-Einheit sowie Gurtabwickelmeßvorrichtung zur Verwendung für das Verfahren