To the Editor: In reading the October issue, I came to the "Letters to the Editor" section where there were two submissions regarding global warming. It is great that both sides of the issue are presented. I believe we are missing a part that should be included in the discussion of our emissions, and how they are affecting the planet.

That part is the fact that we are creating machines, factories, etc., that are producing ever more emissions. What are we emitting that is potentially not good? CO₂, CO, …what about noise? Regardless of global warming, is it all pollution? Is it affecting our health or environment? Smog, asthma, cancer, wildlife, vegetation, etc…

We should be thinking that, regardless of whether it has a hand in global warming, we should be reducing our emissions. If they weren't there before, or not in the amount that we are producing, we should conduct efforts to reduce or eliminate them, especially if we don't know the effect. Why take a chance? Asking for forgiveness later doesn't always work in our favor.

As engineers, we need to reduce waste and emissions in our designs, be educated on what we are producing beyond our designs, and objectively educate others on potential consequences and unknowns. Be heard, be responsible.

Truth or Politics?
Dan Pangburn, P.E.
Fullerton, Calif.

To the Editor: Anthropogenic global warming is popular speculation. But ice core data from Greenland and Antarctica along with other data have allowed scientists to determine the earth's temperature history for over 400,000 years.

The planet regularly warms and cools. Glacial moraines show that glaciers have advanced and receded many times. About 19,000 years ago, at the peak of the most recent glaciation, ice was over a mile thick in Minnesota. The ice core data show that we are about due for the start of another glaciation. The current melting ice may be tough for polar bears and penguins, but in a glacial age over one-third of the human population will starve because rice will not grow on ice. Can the tiny human contribution of greenhouse gas (less than 1 percent) prevent or even delay the next glacial age?

Is the movie An Inconvenient Truth (2006) a way that a resentful politician has found to punish the people of the United States for not electing him president? Why is his carbon footprint 10 times that of the average American? Is this movie really about truth or is it just an example of a particularly prominent basic human instinct to control others? And what of declarations by the IPCC (United Nations Intergovernmental Panel on Climate Change)?

Their declarations might be more credible if the IPCC was not dominated by governments that are envious of the prosperity and freedom that Americans enjoy. Does the Nobel Committee (five politically appointed Norwegians) care about American prosperity?

To the Editor: In reference to the article "Wedge Factor" (October): The best method to curb greenhouse gas emissions is to identify the source of generation. All carbon dioxide emissions are attributed to the high-carbon fuels, such as coal and fossil petroleum derivatives. The carbon-hydrogen ratio plays a vital role.

Coal is the fuel with the maximum carbon content burnt in thermal stations. When coal is gasified, by partial oxidation technology, the carbon content in the synthesis gas is reduced by nearly 50 percent.

The synthesis gas can be further processed to produce dimethyl ether, better than natural gas in net calorific value and equivalent to LPG in boiling point, with lesser heating value but a better fuel, as it is oxygenated. DME is equivalent to diesel in cetane number. It is competitive by price also. DME is selectively used in industry as an aerosol propellant and a refrigerant in blended form.

DME is a good substitute for fossil fuels in the automobile, household, and power sectors. Besides, it is environmentally friendly due to the absence of sulfur and nitrogen.

To the Editor: Kudos to Bridget Mintz Testa and you for the excellent article on the draconian licensing process required to build a nuclear power plant in the United States ("Licensing Renewed," October).

The irony is that our political system has ignored our initial dominance in the field of engineering, fabrication, and operational safety. Unfortunately, the engineering community has never been able to sufficiently educate the public on who the knowledgeable people are (not lawyers and environmentalists). During this anti-nuclear political climate, it is unconscionable how little attention has been given to the unmatched operating experience of the United States Navy.

When working for the nuclear components division of Combustion Engineering Co. during the 1950s, I recall that when a sodium-cooled superheater on the submarine Seawolf leaked, it was removed and the sub returned to service. That era had the presence of Admiral Hyman Rickover, who provided leadership not just for the Navy, but also to the public utility industry.

The Navy as well as Consolidated Edison Co. chose the pressurized water cycle. Edison built Indian Point No. 1, and the Navy went on to establish its peerless operating record. This provided an enormous impetus to the advancement of nuclear power for the military and for commercial electricity.

After reading your article, my recollections led me to suggest that the Departments of Energy and Defense jointly support the building of two nuclear submarines utilizing passive systems, one with PWR and the other BWR technology. This would necessitate early proof of the suitability of passive systems to sea dynamics.

To the Editor: I read the November article "Detecting Wounds in Composites" with interest.

I would like to clarify some points. First, the article states that a triaxial accelerometer was used to collect vibration data, which were then subsequently analyzed using mathematical models. It then further states that this laboratory technique is a system that can detect the magnitude and location of an impact. Is the author suggesting that all missiles be so equipped and analyzed just prior to use? This would hardly be a practical scheme in the field.

The author, Jean Thilmany, also states that the advantage of a fiber-wound case is that it weighs less and is therefore easier and cheaper to ship and handle than it would be for heavier cases. While this statement is true, the real reason for striving for lightweight casings is the gain in flight performance. The mass fraction, i.e., the ratio of propellant weight to the inert weight, mostly due to the case (or of the propellant weight to the total weight) determines the maximum velocity achievable and hence the maximum effective range of the missile.

The author states that the casing is located between the rocket motor and the warhead. Actually, as indicated later on in the article, the casing is part of the rocket motor, the part that contains the propellant. It is subjected to extreme pressure during the motor burn and therefore has to have high axial and hoop strength. With metallic cases the ratio of the two is fixed—basically the tensile strength of the material. With fiber-wound cases the strength ratio can be designed by setting the number of fibers that take load in each direction.

Finally, having an impact resisting case is not the whole story. High-performance solid rocket propellant can be impact-sensitive in itself. Merely dropping a missile during routine handling can cause catastrophic failure immediately after ignition.

To the Editor: The article "50 Years of Nuclear Power" (November) highlighting the 50th anniversary of the first U.S. nuclear power units fails to note that the world's first civil nuclear reactor—the Calder Hall gas-cooled Magnox reactor in Cumbria, U.K.—had come on line significantly earlier.

On Oct. 17, 1956, Her Majesty Queen Elizabeth turned on the switch to begin supplying electricity to the grid. In her speech, she noted, "This new power, which has proved itself to be such a terrifying weapon of destruction, is harnessed for the first time for the common good of our community."

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