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An analysis of the possibilities of theories put forward by Robert Winglee, a geophysicist at the University of Washington, for sailing through space using solar wind as a method of propulsion. Under Winglee's proposals, dubbed Mini-Magnetospheric Plasma Propulsion, a spacecraft would generate a magnetic bubble around itself which would then catch the solar wind to push itself through space.

ABSTRACTTraditional challenges in online condition monitoring systems for power transformer are usually due to discrepant results between online condition monitoring system and lab-based measurements (e.g. Dissolved Gas Analysis) and unreliable performance of electronic components due to exposure to harsh outdoor substation environment. As a result, false alarms and service alarms would be generated and extra maintenance efforts are needed to tackle these issues. This will exert additional pressure to frontline staff and engineers. These undesired outcomes are challenges to the implementation of condition monitoring scheme. Several novel engineering techniques and effective contract management method will be presented in this paper to elaborate the ways to overcome these traditional challenges in online condition monitoring systems to ensure effective condition-based maintenance scheme and enhance power supply reliability.

I ENJOYED the coverage in Maclean's magazine and on its website of Warren Buffett (Interview, Oct. 15; 'Get Buffed up,' Macleans.ca, Oct. 11). But while your Net primer, especially, is [...]

Chemically and mechanically protective coatings are formed on surface of Magnesium alloys by micro-arc oxidation (MAO) methods. From manufacturing perspectives, modification of the obtained MAO surfaces was made in two aspects. Firstly, the protection is enhanced by forming super-hydrophobic surfaces, with water contact angle higher than 120o, attributed to hierarchical nanomicro structures. The overall process involves alkaline etching to form nanoscale structures on top of micro-porous surface achieved during micro-arc oxidation processes. Secondly, the electrical property of the MAO surfaces is modified. A film with electrical conductivity of 2.4Ω/sq is achieved by Ni deposition and characterized by four point probe measurement. The morphology, phase, and chemical composition of all surfaces are investigated by SEM and XRD analysis.

Direct laser writing on biodegradable polymer to create microchannels for aligning cells is presented here. This technique offers the advantages of ease-of-manufacturing, ease-of-design, high-speed single-step fabrication, and noncontacting to the material. In this work, microchannels of 100 μm width, 100 μm depth, and 50 μm intervals were created on a biodegradable polymer film directly using a Ti-sapphire femtosecond pulsed laser. Multiscale topological features were achieved as a result of the laser beam–material interaction. These topological features were used to guide cell alignment in the microchannels. We present results on the morphology of poly(l-lactide-co-ɛ-caprolactone) copolymer micromachined by femtosecond laser and demonstrate the attachment and alignment of C2C12 myoblast cells in the microchannels. C2C12 cells exhibited favorable attachment in the channels after 1 day of seeding. High degree of alignment was observed after 4 days as cells proliferated into a confluent patch inside the channels. This work demonstrated the potential of wavy surface features combined with appropriate channel size for high-density cell alignment using direct laser writing. This method also offers the opportunity to incorporate multiscale topological guidance on other biodegradable polymer implants, such as vascular scaffolds and stents, which require directed cell organization.

This article presents a collection of letters to the editor. There are letters regarding investor Warren Buffett, author Evan Stark and the effects of stress, all from the October 15, 2007, issue.

Presents a letter to the editor in response to an article that claimed that cell phones are replacing cars as a method of self-definition.