Emeritus Faculty Association #106 February 2005
10:30 a.m., Friday, March 4th, Javits Seminar Room, Melville Library E2340. After a social half hour with coffee, fruit, and pastries, courtesy of the Provost's Office, John Fleagle, Distinguished Professor of Anatomical Sciences in the School of Medicine, will give a talk on "Rediscovering Modern Human Origins".The talk will discuss recent paleontological discoveries in Ethiopia that push back the age of our species to almost two hundred thousand years ago. He tells us that the talk will be part travelog, part detective work, and part science. A story on the recent paper in Nature can be found here
Professor Fleagle was born and raised in North Carolina. He received a B.S. in Geology and Geophysics from Yale and a PhD in biological Anthropology from Harvard. He came to Stony Brook in 1975. He has worked on many aspects of primate and human evolutionary biology, and conducted field research in many parts of the world, including India, Malaysia, Suriname, Argentina, Egypt, Kenya, and most recently Ethiopia. He is the founding editor of the journal Evolutionary Anthropology and is an author or editor of numerous books, including Primate Adaptation and Evolution (1988, 1999), Primate Communities (1999) and the Human Evolution Sourcebook (1992, 2005).
Bring your brown bag lunch to continue discussion after the talk. Since President Bush himself has said "On the issue of evolution, the verdict is still out on how God created the earth", so evidently this kind of discussion is still legal.
Homer Goldberg noted the recent death of Leonard Eisenbud, and then introduced one of Eisenbud's former students, Jonathan Sokolov, now a Professor of Material Sciences. Jonathan traced Eisenbud's distinguished career, his experiences during the MaCarthy years, and his love of teaching and profound impact upon his students. Francis Bonner also recalled his association with Eisenbud, having met him at Brookhaven Lab and later introduced him to the campus at Oyster Bay, where Leonard founded the department of physics.
Howard Scarrow noted the presence at the meeting of emeritus Dr. Yassin El-Ayouty, who will give a Provost-sponsored lecture on March 15 in the Wang Center on the topic "Global Training in the Rule of Law".
Francis Bonner introduced the featured speaker, Distinguished Professor Emeritus Jacob Bigeleisen. Francis reviewed his 60 year relationship with Jake, beginning with the Manhattan Project, and later at Columbia University and Brookhaven Lab. He cited Jake's many pioneering research achievements and his founding of the interdisciplinary Gordon Conference. Jake originally came to Stony Brook as Vice President for Research but later "came back home" to the Chemistry Department.
The following summary of this talk on uranium enrichment, is provided by Jake. It draws on his 45 years of experience as a researcher and consultant on this subject, and is timely in view of the announcement last week from North Korea.
Uranium in nature has three isotopes; uranium 234 (0.007%), uranium 235 (0.7%) and uranium 238 (99.3%). The isotope 235 is fissionable. To be useful in bombs it needs to be enriched to greater than 90%. The major use for enriched uranium is for fuel in nuclear power reactors, which is generally 3.2% uranium 235. Enriching uranium isotopes is like any other separation process, only it is a lot harder. Although there are many ways in which one can enrich uranium, only three processes have been put into production at the level of thousands of kilograms. The calutron process is just a large scale mass spectrograph. It was used in Oak Ridge during WWII and enriched uranium 235 to the 90% level in two steps. But it has the disadvantage of low throughput and excessive power requirements. These are not overriding if the objective is to produce material for military purposes. The calutron process was reproduced by Sadam Hussein in Iraq prior to Gulf War 1. It was discontinued in the United States in 1947 in favor of the gaseous diffusion process. The gaseous diffusion process is based on the fact that gaseous molecules of different weight travel at different speeds. This amounts to a difference of 0.004% in the rate at which uranium 235 and uranium 238 pass through a porous membrane. Although this difference is small it is multiplied 4000 fold in commercial plants. Such plants have high throughput and but excessive power requirements. The US built 3 large plants by the mid 1950s mainly to produce 3.2% uranium 235. By 1960 these plants consumed 20% of all the electric power generated in the United States. This is equal to the residential power consumption by 50 million people!
To reduce the power requirements in uranium enrichment there has been a large effort to develop centrifuges for uranium enrichment. The largest development to date has been by the British. Dutch, German combine URENCO. Currently Japan is bringing online a large production plant; a future plant is under contract for construction in the US under license from URENCO. All of these plants are configured to produce 3.2% uranium 235. The centrifuge process has low throughput. To equal the output of one of the US gaseous diffusion plants requires one million of the current URENCO type centrifuges. Plants of this type require sophisticated planning for their configuration and operation. The centrifuges rotate at 60,000 rpm and have a speed of 950 miles per hour at the wall. They are no longer constructed of aluminum alloy.
In the 1970s A.Q.Khan, a metallurgical engineer, worked at the plant in Almelo, Holland which produced centrifuge parts for the URENCO program. He returned to Pakistan in the mid 70s and illegally took with him the plans for the URENCO centrifuge. He then set up a "laboratory" in Pakistan for research and production of centrifuges. We now know that he established a world wide network for the sale of centrifuges and probably also the design of a uranium 235 bomb. Some of his clients have been Libya, China, Iran, and North Korea. Recently, the United States intercepted a shipment of centrifuges bound for Libya. The total Libyan plant was to consist of 4,000 centrifuges, enough capacity to produce 10 Hiroshima type weapons per year. Doing business with Khan is not cheap. For the 4000 centrifuges, which have a market value of $10 million, Libya is reported to have paid $100 million! Libya is not the only oil rich country that has been interested in acquiring access to uranium enrichment. In the 1970s the Shah of Iran purchased a 20% interest in the Eurodif gaseous diffusion plant then being built in France by a consortium of Belgium, France, Italy and Spain. With the fall of the Shah the Ayatollas renounced interest in the venture and eventually they were bought out. The network set up by Khan has resulted in a major setback for nuclear non-proliferation and disarmament.
A convenient summary of nuclear fuel reprocessing can be found here
Website of the month
The American Stroke Association's 2005 International Stroke Conference is being held this month in New Orleans. A study at an earlier session reported that a bystander may be able to spot someone having a stroke by giving the following simple three point test, viz: see if they are able to:
(2) raise both arms and keep them up,
(3) speak a simple sentence coherently.
The test, known as the Cincinnati Prehospital Stroke Scale (CPSS), is the one used by healthcare professionals. The study showed that bystanders can accurately administer such a test themselves. This could be important, since treatment started within three hours of the onset of stroke symptoms can avert loss of function and even save a patient's life. A report can be found: here
Note: Unbelievably, the drugs Celebrex and Bextra which are known to cause stroke and heart problems, are still being actively advertized and marketed. If you are presently taking either of these drugs, it might be wise to consult your physician.