43 research outputs found
Interactions of Rydberg atoms in MOTs.
No full textWe have studied the development of gases of ultra-cold Rydberg atoms in Magneto Optic Traps, and discovered that such gases exhibit a range of density-dependent phenomena. In particular, we have found that at the densities of ∼ 107 cm-3 the Rydberg atoms spontaneously evolve into long-lived high angular momentum states. These states slowly decay due to microwave background radiation over tens of milliseconds. We have numerically simulated the effects leading to such behavior, and investigated numerically the l- and n-mixing collisions of Rydberg atoms with electrons in the range of 10 meV. These calculations show that the l- and n-mixing cross-sections follow the n5 scaling law, expected from simple Stark map considerations, but also depend on the velocities of the colliding electrons, reflecting the adiabaticity of the atom-electron interactions. We have developed a novel technique of measuring the electric fields inside plasmas by using Rydberg excitation spectroscopy of embedded atoms, based on the disappearance of regions of zero oscillator strength in the presence of such fields. We have applied this technique to study the evolution of ultra-cold non-neutral plasmas excited from the MOT, and have found that it expands over 1 mus. We have simulated such an expansion by considering only Coulomb repulsion between the constituent ions, and have found that such a model is consistent with the experimental observations.PhDAtomic physicsOpticsPlasma physicsPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/123772/2/3106000.pd
The advanced LIGO input optics
No full textAbstract not availableChris L. Mueller ... Eleanor J. King ... et.a
[Human Cloning Hearing]
No full textHuman Cloning Hearing[Packet of materials includes: witness list, news release from Senator Sam Brownback; Testimony of Rep. David Weldon; Testimony of Margaret Colin; Prepared Testimony of Clarke D. Forsythe; Testimony of Clarke D. Forsythe; Testimony of Rudolf Jaenisch; Testimony of Leon R. Kass; Statement of William Kristol; Testimony of Robert A. Best; Oral Remarks of Richard M. Doerflinger; Testimony of Richard M. Doerflinger; Testimony of Carl B. Feldbaum; Testimony of Jaydee Hanson; and supporting documents from the Pew Forum, the Family Research Council, NCCB [National Conference of Catholic Bishops; Secretariat for Pro-Life Activites fact sheet, Washington Post article 1994 October 2; Letter from National Right to Life Committee; Letter from the Wilberforce Forum; list of current clinical use of adult stem cells to help human patients as contrasted to no conditions for which embryonic stem cells are in clinical use to help human patients; Do No Harm's Current Clinical and Potential Applications of Adult Stem Cells; Do No Harm's Embryonic Stem Cell Study Replicates Adult Stem Cell Advances Achieved Over a Year Ago; Do No Harm's Adult Stem Cell Advances Continue to Challenge "Need" for Destructive Embryonic Research: Time to "Revisit" Adult Stem Cell Progres
Report to Congress - Safe Havens: Supervised Visitation and Safe Exchange Services and Programs
No full textThis report provides the most thorough profile to date of supervised visitation and exchange programs in the United States, including information on types of services, common barriers to service, and the number of individuals being seen in these programs who experienced several forms of violence and abuse. Major findings include: a) dangerousness and unwillingness to agree to program rules limits acceptance for service; b) service is limited by capacity, hours, and transportation; c) family violence is one of the major reasons for supervised visitation; d) funding limitations are linked to safety needs.United States Department of Justice, Office on Violence Against Women (#2003 WT BX K043)http://deepblue.lib.umich.edu/bitstream/2027.42/115464/1/Safe Havens National Survey 2006 Report to Congress - 5-27-08 & author page.pdfDescription of Safe Havens National Survey 2006 Report to Congress - 5-27-08 & author page.pdf : Main Repor
Artificial dielectric devices for variable polarization compensation at millimeter and submillimeter wavelengths
No full textVariable polarization compensation has been demonstrated at 100 GHz. The device consists of two interlocking V-groove artificial dielectric gratings that produce a birefringence that varies with the separation distance. A maximum retardance of 74/spl deg/ has been obtained experimentally in a silicon device, in good agreement with rigorous coupled-wave computer simulations. Further simulations predict that adding quarter wave dielectric antireflection (AR) coatings to the outer surfaces of the device can reduce the insertion loss to below 4 dB. The use of rectangular grooved gratings provides increased retardance and reduced loss. It is predicted that a coupled device with rectangular grooved gratings will be capable of maximum retardance in excess of 180/spl deg/, with low insertion loss (<0.6 dB). The sensitivity of the wave retardation as a function of mechanical separation has a peak value of 485/spl deg//mm. The design and micromachining fabrication techniques scale for operation at submillimeter wavelengths
Publisher's Note: Search for gravitational waves from binary black hole inspiral, merger, and ringdown
No full textThis paper was published online on 6 June 2011 with an omission in the Collaboration author list. S. Dwyer has been
added as of 12 April 2012. The Collaboration author list is incorrect in the printed version of the journal
The Impact of Health Insurance Schemes for the Informal Sector in Low- and Middle-Income Countries: A Systematic Review
No full textThis paper summarizes the literature on the impact of state subsidized or social health insurance schemes that have been offered, mostly on a voluntary basis, to the informal sector in low-and middle-income countries. A substantial number of papers provide estimations of average treatment on the treated effect for insured persons. We summarize papers that correct for the problem of self-selection into insurance and papers that estimate the average intention to treat effect. Summarizing the literature was difficult because of the lack of (1) uniformity in the use of meaningful definitions of outcomes that indicate welfare improvements and (2) clarity in the consideration of selection issues. We find the uptake of insurance schemes, in many cases, to be less than expected. In general, we find no strong evidence of an impact on utilization, protection from financial risk, and health status. However, a few insurance schemes afford significant protection from high levels of out-of-pocket expenditures. In these cases, however, the impact on the poor is weaker. More information is needed to understand the reasons for low enrollment and to explain the limited impact of health insurance among the insured. JEL codes: I10, I15. © The Author 2012. Published by Oxford University Press on behalf of the International Bank for Reconstruction and Development/ THE WORLD BANK. All rights reserved
