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Post by skytroll on Sept 5, 2007 15:26:33 GMT -5
zms.desy.de/research/index_eng.htmlAn internal polarized{sup 3}He target is currently under construction at MIT. The target will be used in the HERMES experiment, which will measure the spin dependent deep inelastic scattering from the neutron and proton by the scattering of 30-35 GeV longitudinally polarized electrons from polarized hydrogen, deuterium, and{sup 3}He in the East Hall of HERA. The target is based on the technique of metastability exchange laser optical pumping.{sup 3}He nuclei are introduced into a glass cell, where they are polarized with high intensity laser light. The nuclei then migrate out of the glass cell into a windowless storage cell where they are allowed to interact with the beam before being pumped away. Two pairs of Helmholtz coils will be employed to create a magnetic field which will orient the{sup 3}He nuclei along one of two axes. The storage cell will be cryogenically cooled to 15K, giving a density of 10{sup 15} atoms/cm{sup 2}. Target polarizations of over 50% are expected. The present status of the HERMES target will be discussed. www.osti.gov/energycitations/product.biblio.jsp?osti_id=387147
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Post by skytroll on Sept 5, 2007 15:28:10 GMT -5
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Post by skytroll on Sept 5, 2007 15:37:04 GMT -5
en.wikipedia.org/wiki/Helium_3#Extraterrestrial_suppliesen.wikipedia.org/wiki/Logic_gate#Symbolsnetron probes; en.wikipedia.org/wiki/Neutron_Probeen.wikipedia.org/wiki/Fiber_opticsen.wikipedia.org/wiki/Optical_time_domain_reflectometeren.wikipedia.org/wiki/Optical_return_lossCLIFFORD PREVENGE WHITEROSE .......... ANY MEANING goes back to NMR and Sup 35 folding and unfolding proteins or do we mean protons? NMR Sup 35 or any Sup? sup 35/Cl nmr relaxation rate measurements have been used to study anion-binding sites in pig heart lactate dehydrogenase.^These studies reveal two types of sites, one is intimately associated with the active site, the other is not.^The nonactive site has been ascribed to a subunit site in analogy with crystallographic results from the dogfish M/sub 4/ enzyme.^The binding of either the reduced or the oxidized form of NAD results in an increase in the /sup 35/Cl nmr relaxation rate by a factor of 1.8-2.^The enhanced nmr relaxation rate of the binary lactate dehydrogenase--NAD complex is reduced on binding of the substrate inhibitor molecules oxamate or oxalate to a value less than that exhibited by lactate dehydrogenase alone.^The enhancement of the nmr relaxation rate is attributed to a decrease in the dissociation constant of Cl/sup -/ for the enzyme.^The K/sub D/ values for Cl/sup -/ binding to the active center site of lactate dehydrogenase are 0.85 M and for lactate dehydrogenase--NADH is 0.25 M. The ratio of these constants, 3.4, agrees well with the measured enhancement value 3.7.^The effect of coenzyme analogs on the /sup 35/Cl nmr relaxation rate has been examined.^3-Acetylpyridine NAD produces an enhancement of 4.3, thionicotinamide NAD of 2.3, whereas 3-pyridinealdehyde, adenosinediphosphoribose, and adenosine diphosphate do not affect the nmr relaxation state of Cl/sup -/ bound to lactate dehydrogenase.^(auth) Country of Publication United States www.osti.gov/energycitations/product.biblio.jsp?osti_id=7358701Skytroll
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Post by skytroll on Sept 5, 2007 15:40:58 GMT -5
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