Analytic pressure-volume diagrams are utilized to illustrate the effects of gasoline engine design on performance and combustion requirements. Topics discussed include design, construction, inspection techniques and servicing of the internal combustion engine and its components. Laboratory activities are performed to provide relevant hands-on experience to the students. Also engine aspiration, combustion using the principles of fluid dynamics and thermodynamics, volumetric efficiency and fuel metering systems will be discussed in this course.
December 8, NASA: Life with arsenic December 7, Last week, in a much publicized news conference, NASA announced the discovery of a bacterium that can use arsenic instead of phosphorus.
The news media covered it with a flourish -- and produced much nonsense. The paper was posted at the Science magazine web site, so we can look at what was really shown.
Whatever the hype that the news media added, it is an interesting -- but incomplete -- story. The figure at left shows a key experiment; this is Figure 1B of the paper.
The graph shows the growth of the bacteria under different conditions. Number of cells on the y-axis log scale ; time on the x-axis. The three conditions are, from the top: Importantly, if there is no addition, the bacteria grow very little, if at all lower curve.
Then, arsenic in the form of arsenate does indeed stimulate growth middle curve. So does phosphate; in fact, it is better upper curve. The above experiment along with other measurements does seem to establish the basic point: But now let's look at some of the limitations of the story -- as we have it so far.
First, the bug prefers P to As: You can see this in the graph above. They explicitly do not claim that the bug requires or prefers As, merely that it can use it. Second and more importantly, the growth medium with no added P contains a trace level of P.
This probably comes from low levels of P contaminating other chemicals they use. It's not enough to support growth alone lower curve in the graphbut it does mean that when the bugs are growing on As, they also have a small amount of P available.
In fact, analysis of the bacteria grown on As shows a weight ratio of about 7 As: On a mole basis, the ratio would be about half that.A candle for Christmas December 20, Musings posts items of historical interest from time to time. This one is a book: a book about what happens when a candle burns, a book about chemistry -- premised on the observations of the candle.
Devil In The Dark () The Horta was an example of Silicon life.; Now we are really sailing off into terra incognito. "Here be dragons" and all that. But if you have starships, you almost have to have aliens (Isaac Asimov's Foundation trilogy being the most notable exception).The "science" is called Astrobiology, the famous "science in search of a subject".
Dynamically updated essay by Vincent Giuliano on theories of aging and protective firewalls. serious and humerous. Subjects include longevity, health, anti-aging.
A PA since and creator of The PA Life Website. A National Health Service Corps Scholar and a graduate of The University of Medicine and Dentistry of NJ (Rutgers) PA Program and the University of Washington in Seattle, WA. Ingram Micro Strengthens Position as Leading Global Repairs and Regeneration Services Provider with Acquisition of ANOVO March 2, am.
Molecules called lipids have long hydrocarbon chains that determine the way they act. They can be fats, oils, or hormones, and even exist in our cell membranes. Learn more about the chemical structure and biological function of various lipids in this lesson.