 | Should Google Go Nuclear? Clean, cheap, nuclear power... Google Tech Talks November 9, 2006 ABSTRACT This is not your father's fusion reactor! Forget everything you know about conventional thinking on nuclear fusion: high-temperature plasmas, steam turbines, neutron radiation and even nuclear waste are a thing of the past. Goodbye thermonuclear fusion; hello inertial electrostatic confinement fusion (IEC), an old idea that's been made new. While the international community debates the fate of the politically-turmoiled $12 billion ITER (an experimental thermonuclear reactor), simple IEC reactors are being built as high-school science fair projects. Dr. Robert Bussard, former Asst. Director of the Atomic Energy Commission and founder of Energy Matter... |
 | 4*3 g=0.9 flux tube interactions 4 N=3 flux tubes interacting to form a 4-vortex in a charged proton neutron system. Top slice is the Gauge energy density (E^2 +B^2), middle slice is the neutron condensate*10, lower slice is the proton condensate with iso-surface 0.1 away from the vev. the proton density is 10% of the neutrons, and the P_N coupling is 0.5. g=0.9 and all other coupling set to 1. No entrainment interaction. I have added a low temperature gauge invariant perturbation in the beginning of the simulation to catalyze an possible instabilities that might appear due to too much symmetry in the initial conditions. Note that the neutrons are over-dense in the proton vortex regions... |
 | 3d Type 1 Nucleonic Flux Tubes 2 N=3 flux tubes interacting to form a 6-vortex and 2 N=-1 form a N=-2 in the charged proton neutron system. Blue is a Gauge energy density (E^2 +B^2) isosurface, green the neutron condensate -0.04 from the vev , red is the proton condensate with isosurface 0.5 away from the vev. the proton density is 10% of the neutrons, and the P_N coupling is 0.5. g=2.0 and all other coupling set to 1. No entrainment interaction... I have added a low temperature gauge invariant perturbation in the beginning of the simulation to catalyze an possible instabilities that might appear due to too much symmetry in the initial conditions. This shows that the 2d simulation captures very well the full 3d as small perturbations in the flux tube structure do not amplify to perturb the z direction symmetry. |
 | A Star's Life Cycle A STAR'S LIFE CYCLE- The life of a star is explained in this video. A star begins as a large, cool mass of gas, which is forced to contract due to gravity. Temperature rises eventually lead to a process of nuclear fusion that produces a steady and vast output of energy. Its life can last about 10 billion years before its energy supply is exhausted and it collapses. Depending on their size, stars can finally become white dwarfs, supernovas, black dwarfs, neutron stars, or black holes. |
 | Pig waste as a fuel After a close examination of crude oil made from pig manure, chemists at the National Institute of Standards and Technology (NIST) are certain about a number of things. Most obviously, "This stuff smells worse than manure," says NIST chemist Tom Bruno. But a job's a job, so the NIST team has developed the first detailed chemical analysis revealing what processing is needed to transform pig manure crude oil into fuel for vehicles or heating. Mass production of this type of biofuel could help consume a waste product overflowing at U.S. farms, and possibly enable cutbacks in the nation's petroleum use and imports. But, according to a new NIST paper,* pig manure crude will require a lot of refining. The ersatz oil used in the NIST analyses was provided by engineer Yuanhui Zhang of the University of Illinois Urbana-Champaign. Zhang developed a system using heat and pressure to transform organic compounds such as manure into oil. As described in the new paper, Bruno and colleagues determined that the pig manure crude contains at least 83 major compounds, including many components that would need to be removed, such as about 15 percent water by volume, sulfur that otherwise could end up as pollution in vehicle exhaust, and lots of char waste containing heavy metals, including iron, zinc, silver, cobalt, chromium, lanthanum, scandium, tungsten and minute amounts of gold and hafnium. Whatever the pigs eat, from dirt to nutritional supplements, ends up in the oil. While the thick black liquid may look like its petroleum-based counterparts, the NIST study shows that looks can be deceiving. "The fact that pig manure crude oil contains a lot of water is unfavorable. They would need to get the water out," Bruno says. The measurements were made with a new NIST test method and apparatus, the advanced distillation curve, which provides highly detailed and accurate data on the makeup and performance of complex fluids. A distillation curve charts the percentage of the total mixture that evaporates as a sample is slowly heated. Because the different components of a complex mixture typically have different boiling points, a distillation curve gives a good measure of the relative amount of each component in the mixture. NIST chemists enhanced the traditional technique by improving precision and control of temperature measurements and adding the capability to analyze the chemical composition of each boiling fraction using a variety of advanced methods. NIST researchers analyzed the graphite-like char remaining after the distillation by bombarding it with neutrons, a non-destructive way of identifying the types and amounts of elements present. Two complementary neutron methods detected the heavy metals listed above. Bruno and colleagues currently spend much of their time analyzing military jet fuels and are not planning a major foray into pig manure. But Bruno concedes that the effort may have a payoff. "Who knows, it might help decrease the nuisance of manure piles." For more on the process of making pig waste crude, see "Converting Manure to Oil: U of I Lays Groundwork for One-of-a-Kind Pilot Plant". * L.S. Ott, B.L. Smith and T.J. Bruno. Advanced distillation curve measurement: Application to a bio-derived crude oil prepared from swine manure. Fuel (2008), doi:10.1016/j.fuel.2008.04.038. Media Contact: Laura Ost, laura.ost@nist.gov, (303) 497-4880 |
 | A tribute to Guangyong Xu UPTON, NY - Scientists at the U.S. Department of Energy's Brookhaven National Laboratory and collaborating institutions around the world have detected a hidden "string order" that extends over a length of 30 nanometers (billionths of a meter) in a material that is otherwise apparently disordered. The findings, which will be published online on Thursday, July 26, 2007 by Science, could have implications for the design of materials at the nanoscale, including those used for a developing concept known as quantum computing. In quantum computing, data are recorded using quantum properties, such as electron spins, instead of ordinary magnetism. It is widely believed that if large-scale quantum computers can be built, they will be able to solve certain problems exponentially faster than classical computers. "Our goal is to understand the factors that affect the distance over which the hidden 'string order,' or quantum phase coherence, can be maintained," says Brookhaven Lab physicist Guangyong Xu, lead author on the paper. That distance - and how sensitive it is to changes in temperature or chemical impurities in the material - can be essential in determining whether a material will have useful applications. "If you are manufacturing something, you don't want a certain property to be maintained only at one spot," Xu explains. "You want the property maintained throughout the material." In quantum computing, the material also needs to be scalable physically to increase the amount of information it can store, and coherence must be maintained over a relatively long time, "otherwise your computing information would be lost over time," Xu says. The findings in this paper have clear implications related to these problems. To look for the quantum phase coherence and get a handle on the factors that affect it, Xu and his collaborators studied a one-dimensional quantum spin liquid consisting of chains of nickel-oxygen-nickel atoms. A quantum spin liquid is a system in which the electron spins (analogous to tiny bar magnets) point in random directions with no particular order, even at very low temperatures. To find out if there was phase coherence throughout this otherwise disordered system, the scientists used inelastic neutron scattering to see if magnetic excitations -- "flips" or fluctuations of the spins -- could propagate far enough along the spin chains. "Neutron scattering is a very powerful and probably the most direct tool in studying orders in spin systems", says Xu. The experiments were performed at the National Institute of Standards and Technology (NIST) Center for Neutron Research and at the ISIS pulsed neutron source at the Rutherford Appleton Laboratory in the U.K. They found that despite the apparent disorder, magnetic excitations could propagate over long ranges - up to 30 nanometers at low temperature. "We found order in an otherwise disordered system," Xu said. Other examples of large-scale quantum phase coherence include superconductors and superfluids where quantum physics leads to fascinating properties. The scientists also found they could limit the coherence or make it disappear altogether by introducing impurities into the material either by adding other elements (doping) or heating. In essence, these impurities break the chain. This implies that methods might be developed to tailor make materials with coherence at particular lengths. Xu cautions that his team's work is not intended to have direct application, but suggests that what they are learning could be applied by others in a range of fields related to nanofabrication and quantum computing. Collaborators on this research include: Collin L. Broholm, Ying Chen, and Michel Kenzelmann of Johns Hopkins University and the NIST Center for Neutron Research; Yeong-Ah Soh of Dartmouth College; Gabriel Aeppli of the London Centre for Nanotechnology and University College London; John. F. DiTusa of Louisiana State University; Christopher D. Frost from the ISIS Facility, Rutherford Appleton Laboratory, U.K.; Toshimitsu Ito and Kunihiko Oka of the National Institute of Advanced Industrial Science and Technology (AIST), Japan; and Hidenori Takagi from AIST and University of Tokyo. The work was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science, the National Science Foundation, the Wolfson-Royal Society (UK), and by the Basic Technologies program of the UK Research Councils. Note to local editors: Guangyong Xu lives in Coram, New York. |
 | Lec 35 | 8.01 Physics I: Classical Mechanics, Fall 1999 Farewell Special - High-energy Astrophysics View the complete course: http://ocw.mit.edu/8-01F99 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu |
 | Lec 23 | 8.01 Physics I: Classical Mechanics, Fall 1999 Doppler Effect - Binary Stars - Neutron Stars and Black Holes View the complete course: http://ocw.mit.edu/8-01F99 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu |
 | Lec 36 | MIT 8.02 Electricity and Magnetism, Spring 2002 Farewell Special Bring a Friend! View the complete course: http://ocw.mit.edu/8-02S02 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu |
 | Lec 33 | 8.01 Physics I: Classical Mechanics, Fall 1999 Kinetic Gas Theory - Ideal Gas Law - Isothermal Atmosphere - Phase Diagrams - Phase Transitions View the complete course: http://ocw.mit.edu/8-01F99 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu |
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