Light Traction

Whereas Plug Power, Nuvera, and Hydrogenics using pressurized hydrogen as fuel (350bar) the Oorja Protonic systems use methanol. The Oorja DMFC system has a lower power output than the hydrogen systems and it does not replace the complete battery, but in combination with a conventional battery it is used as a range extender. 

In the light traction sector, the only marketable products in Germany are also manufactured by SFC Energy. They are based on the DMFC EFOY Pro Series. These devices are referred to as range extenders, internal chargers for the batteries of electric scooters or small electric cars with a maximum electric power of 90 W, which make the range of these vehicles greater. 

The strategy for stationary appHcations of fuel cells for decentrahzed energy supply in the power range from 1 to 5 kWei for private households and from 

100 to XOOO kWei for industrial and local facilities has changed numerous times. Development is currently focused on small- and medium-sized SOFC systems, which are undergoing intensive field testing all over the world. The benchmark for the electrical efficiency of a 1.5 kWei system produced by CFCL is 60%. 

European Commission (2003) Wasser-stoffenergie und Brennstqffzellen -Bine Zukunftsvision, EUR 20719 DE, European Commission, Brussels. 

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Mobile applications with a power range between 100 W and 5kW are called light traction applications [51]. Similarly to automotive applications, fuel cells are also very attractive for these special vehicles as they are emission free and offer a very fast recharge [51]. The group of light traction applications includes scooters, forklift trucks, and commercial vehicles. The following technical overview gives some examples. 

As has been described, DM PCs are attractive for light traction appHcations with power capadties lower than 5 kW. Another low-power appHcation is a humanoid robot, and an example was described in [94]. A DMFC stack of 405 W was coupled with a 200 Wh battery via a DC-DC converter. 

Janssen, H., Blum, L, Hehemann, M., Mergel, J., and Stolten, D. (2010) System technology aspects for light traction applications of direct methanol fuel cells. Presented at the 18th World Hydrogen Energy Conference, Essen, May 2010. 

For both DMFC systems for light traction and for DMFC systems for portable applications, Nafion is still the standard membrane material. A general overview of the polymer electrolyte membrane materials, their modifications, and their function can be found in. [107] and with the focus on the DMFC operation in [108]. 

DMFCs are an interesting option, e.g. in portable power generation, light traction, etc. For these applications, most system designs rely on feeding fuel from the liquid phase. 

User-Related Properties. The most important element in the player s contact with the surface is traction. Shoe traction for light-duty consumer purposes need address only provision of reasonable footing. The frictional characteristics are obviously of much greater importance in surfaces designed for athletic use. For specialized surfaces such as a track, shoe traction is especially critical. With grass-like surfaces, traction is significantly affected by pile density and height, and other aspects of fabric constmction. 

Other benefits of light-colored roofs include a potential increase in their useful life. The daily temperature fluctuation and concomitant expansion/coii-traction of a light-colored roof is less than that of a dark one. Also, materials degradation because of absorption of ultra-violet light is temperature-dependent. Thus, cooler roofs may last longer than... 

Fuel economy for the new vehicle "fleet, including light trucks (actual mpg and mpg adjusted for mass, power, and with light truck traction frozen at 29 percent (1986 value). 

A second type of cytokinesis has come to light in mutants of Dictyostelium lacking mysoin-II. These cells are able to crudely separate by traction mediated cytokinesis, a process by which the bi- (or multi-) nucleate cells tear themselves apart in an attempt to crawl in two opposite directions. 

Viscosity, defined as the resistance of a liquid to flow under an applied stress, is not only a property of bulk liquids but of interfacial systems as well. The viscosity of an insoluble monolayer in a fluid-like state may be measured quantitatively by the viscous traction method (Manheimer and Schechter, 1970), wave-damping (Langmuir and Schaefer, 1937), dynamic light scattering (Sauer et al, 1988) or surface canal viscometry (Harkins and Kirkwood, 1938 Washburn and Wakeham, 1938). Of these, the last is the most sensitive and experimentally feasible, and allows for the determination of Newtonian versus non-Newtonian shear flow. 

Recently, the major activity in transportation fuel cell development has focused on the polymer electrolyte fuel cell (PEFC). In 1993, Ballard Power Systems (Burnaby, British Columbia, Canada) demonstrated a 10 m (32 foot) light-duty transit bus with a 120 kW fuel cell system, followed by a 200 kW, 12 meter (40 foot) heavy-duty transit bus in 1995 (26). These buses use no traction batteries. They operate on compressed hydrogen as the on-board fuel. In 1997, Ballard provided 205 kW (275 HP) PEFC units for a small fleet of hydrogen-fueled, full-size transit buses for demonstrations in Chicago, Illinois, and Vancouver, British Columbia. Working... 

The world market for batteries of all types now exceeds 100 billion. Over half of this sum is accounted for by lead-acid batteries - mainly for vehicle starting, lighting and ignition (SL1), and industrial use including traction and standby power, with about one-third being devoted to primary cells and the remainder to alkaline rechargeable and specialist batteries. 

SLI batteries (starting, lighting and ignition) 100-600 Wh Cars, trucks, buses, tractors, lawn mower traction... 

The latter batteries are used for such different applications as in consumer elee-tronics, in vehicles for starting, lighting, and ignition (SLI) and for traction, as emergency power supplies, in load-leveling systems of electric power stations to supply peak demand, and as systems to couple with alternative energy sources. 

Interfacial Viscosity. In a clean system in which two pure liquids produce an interface, the viscosity of the interface should be the same as the bulk solution viscosity. However, surfactant or impurity adsorption at an interface can cause a resistance to fiow to occur that can be measured as the interfacial shear viscosity. This viscosity is defined as the ratio between the shear stress and the shear rate in the plane of the interface (12), Methods used to make these measurements include a viscous traction surface viscometer (J2), droplet-droplet coalescence (J3), the rotating ring viscometer (14), and surface laser light scattering (9). 

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