Physical and Biogeochemical Studies in the Subtropical and Tropical Atlantic

Maria S. Merian Cruise Report MSM18/L2 Cruise No. 18, Leg 2 May 11 – June 19, 2011 Mindelo (Cape Verde Islands) – Mindelo (Cape Verde Islands

An Analysis on the Detection of Biological Contaminants Aboard Aircraft

The spread of infectious disease via commercial airliner travel is a significant and realistic threat. To shed some light on the feasibility of detecting airborne pathogens, a sensor integration study has been conducted and computational investigations of contaminant transport in an aircraft cabin have been performed. Our study took into consideration sensor sensitivity as well as the time-to-answer, size, weight and the power of best available commercial off-the-shelf (COTS) devices. We conducted computational fluid dynamics simulations to investigate three types of scenarios: (1) nominal breathing (up to 20 breaths per minute) and coughing (20 times per hour); (2) nominal breathing and sneezing (4 times per hour); and (3) nominal breathing only. Each scenario was implemented with one or seven infectious passengers expelling air and sneezes or coughs at the stated frequencies. Scenario 2 was implemented with two additional cases in which one infectious passenger expelled 20 and 50 sneezes per hour, respectively. All computations were based on 90 minutes of sampling using specifications from a COTS aerosol collector and biosensor. Only biosensors that could provide an answer in under 20 minutes without any manual preparation steps were included. The principal finding was that the steady-state bacteria concentrations in aircraft would be high enough to be detected in the case where seven infectious passengers are exhaling under scenarios 1 and 2 and where one infectious passenger is actively exhaling in scenario 2. Breathing alone failed to generate sufficient bacterial particles for detection, and none of the scenarios generated sufficient viral particles for detection to be feasible. These results suggest that more sensitive sensors than the COTS devices currently available and/or sampling of individual passengers would be needed for the detection of bacteria and viruses in aircraft

Laserschweissen neuartiger Schiffskonstruktionen auf Basis des verdeckten T-Stosses Abschlussbericht

Conventional arc welding techniques used in shipbuilding are characterized by high heat input resulting in a large extent of set-up, straightening and adjustment operations. This also complicates subsequent outfitting work. The need for lightweight structures leads to the development of new design solutions, better exploiting material properties while enhancing the operational behaviour. Laser welding techniques both reduce heat distortions and allow for new structural solutions. The project aims at the development and exploitation of laser welded sandwich panels in the shipbuilding industry. Emphasis was put on the following aspects: Installation of a prototype laser welding station and development of the welding process. Development of a quality assurance system and qualification of the panels. Investigations on operational properties of sandwich panels and development of design solutions. Assembly and subsequent manufacturing processes for sandwich panels in a shipyard environment. Laser welded sandwich panels have already been used in newbuilding ships. e.g. by Meyer Werft, and in other industries. Due to their improved properties and modulare premanufacturing techniques sandwich panels are competitive against conventional stiffened plates. (orig.)SIGLEAvailable from TIB Hannover: F99B1727 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

New contact probe and method to measure electrical resistances in battery electrodes

Electrical resistivity is an important measure to qualify electrodes for lithium-ion batteries. A reliable determination of conductivity is of high practical importance with regard to, for example, electrode production improvements and quality control. To complement state-of-the-art measuring techniques, a new method has been developed based on a new “micron-powder probe”. Following a simple measuring procedure, the system allows nondestructive, highly reproducible, and rapid data acquisition. In this paper, we describe the new concept thoroughly and present experimental results. These results demonstrate that an initial determination of resistance values in battery electrodes is beneficial especially if it is combined with an electrical postmortem analysis of cycled cathode disks. The outcome of our investigation is validated with regard to the electrochemical performance of cathodes in half-cells