Spacing specific power

A multiplier can be used to represent values larger or smaller than the basic unit (gram, liter, meter, etc.). The multipliers are ten raised to a specific power, as listed in Table 1-1. This system avoids the necessity of having different basic units, such as the inch, foot, yard, or ounce, pint, quart, gallon, etc. The multiplier abbreviation precedes the symbol of the base unit with neither a space nor punctuation an example is m in mL,... 

Typical polarization curves for alkaline fuel cells are shown in Fig. 27-63. It is apparent that the alkaline fuel cell can operate at about 0.9 V and 500 mA/cm current density. This corresponds to an energy conversion efficiency of about 60 percent HHV. The space shuttle orbiter power module consists of three separate units, each measuring 0.35 by 0.38 by 1 m (14 by 15 by 40 in), weighing 119 kg (262 lb), and generating 15 kW of power. The power density is about 100 W/L and me specific power, 100 W/kg. 

A sul fated polystyrene ion-exchange membrane was used as the electrolyte in these fuel cells. The electrodes contained about 4 mg/cm of a platinum catalyst. Because of the marked ohmic resistance of the membrane, the current density was below 100 mA/cm, with a voltage of about 0.6 V for an individual cell. This corresponds to a specific power of the fuel cell of about 60 mW/cm. Because of the insufficient chemical stability of the membrane used, the total lifetime of the battery was below 2000 h. The high cost of such a battery excluded uses in fields other than space flight. 

It is obvious from the calculations above that the silicon-based DMFC devices can be manufactured with lager electrodes to achieve much higher volumetric energy density. The fuel cell can be stacked to meet specific power requirements. Furthermore, dimensions of the surface areas can be altered to accommodate the fuel cell in a given space. In other words, one dimension can be slightly smaller or larger than the other to accommodate the device in a given available space. 

The lithium/sulfur dioxide (Li/S02) battery is the most advanced of these lithium primary batteries. These batteries are typically manufactured in cylindrical configurations in capacities up to about 35 Ah. They are noted for their high specific power (about the highest of the lithium primary batteries, high energy density, and good low-temperature performance. They are used in military and specialized industrial, space and commercial applications where these performance characteristics are required. 

This section describes potential design events for the Space Nuclear Power Plant (SNPP). Design events applicable specifically to the Ground Test Reactor (GTR) are listed in Section 11.3. A list of design events would have been finalized after the reactor module functional requirements were established and the system architecture selected. 

The Naval Reactors program was specifically chartered to work on a deep space nuclear power system for the Jupiter Icy Moons Orbiter (JIMO) mission. The requirements for the Deep Space Vehicle (which includes the Reactor Module) included multi-mission capability for other civilian deep space exploration missions. The high level requirements of the Prometheus project also included that the nuclear power technologies developed be extensible to Moon/Mars surface exploration missions. This requirement of extensibility was implemented by NASA through Level 1 and Level 2 requirements as discussed below. 

Independent molecules and atoms interact through non-bonded forces, which also play an important role in determining the structure of individual molecular species. The non-bonded interactions do not depend upon a specific bonding relationship between atoms, they are through-space interactions and are usually modelled as a function of some inverse power of the distance. The non-bonded terms in a force field are usually considered in two groups, one comprising electrostatic interactions and the other van der Waals interactions. 

This reaction has been carried out with a carbon dioxide laser line tuned to the wavelength of 10.61 p.m, which corresponds to the spacing of the lowest few states of the SF ladder. The laser is a high power TEA laser with pulse duration around 100 ns, so that there is no time for energy transfer by coUisions. This example shows the potential for breakup of individual molecules by a tuned laser. As with other laser chemistry, there is interest in driving the dissociation reaction in selected directions, to produce breakup in specific controllable reaction channels. 

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