Science.gov

Sample records for ainola tiit koppel

  1. On the connection between the Koppel-Young and the Nelkin Models for thermal neutron scattering in water molecules

    SciTech Connect

    Markovic, M.I.

    1982-10-01

    A critical analysis of the Koppel-Young model is presented and compared with Nelkin's model and their equivalence is asserted. It is shown that the only distinction between the two models is in the orientational averaging of the rotational-vibrational intermedial scattering function. Based on total cross sections, the Krieger-Nelkin orientation averaging has been confirmed to give excellent agreement with the Koppel-Young orientation averaging. However, significant quasi-periodical differences are observed when calculating differential cross sections. As a result of these insights, a new unified model is proposed for microdynamics of water molecules.

  2. Quill v. Koppell.

    PubMed

    1994-12-15

    The U.S. District Court, S.D. New York upheld the constitutionality of a statute criminalizing physician-assisted suicide. The claimants argued that the statute violated the due process and equal protection clauses of the Fourteenth Amendment for both the patients and the physicians. They claimed that competent, terminally-ill persons have a constitutional right to take their own lives, and that enabling physicians have a corresponding protection under the constitution. However, while the court recognized constitutional protections for many personal decisions as central to the liberty protected by the Fourteenth Amendment, it determined that precedent failed to establish such right under the constitution. The court validated state authority to distinguish between "allowing nature to take its course" and the intentional use "of an artificial death-producing device" by reasoning that suicide evokes a different legal significance than refusing medical treatment.

  3. Living Well with COPD, Q&A: Grace Anne Koppel | NIH MedlinePlus the Magazine

    MedlinePlus

    ... What needs to be done to address this gender disparity? Through recent research, we have come to ... also that women have a more toxic reaction. Gender is not the only disparity in COPD. Those ...

  4. Army National Guard and Civil Support Operations: Closing the Interagency Gap at the Local Level

    DTIC Science & Technology

    2010-05-21

    current missions. The only people who seemed aware of the situation were the media. When FEMA Director Michael Brown told Ted Koppel on Nightline...Thursday night that he just learned about the situation at the Convention Center that day, Koppel pointedly asked if FEMA officials watched

  5. The Law of Unintended Consequences: The Case of External Subgoal Support

    DTIC Science & Technology

    2014-05-01

    provider order entry. Journal of the American Medical Informatics Association. 13, 5, 547-556. [20] Koppel , R., Metlay, J. P., Cohen, A., Abaluck, B...journal of the American Medical Association. 293, 10, 1197-1203. [21] Koppel , R., Wetterneck, T., Telles, J. L., and Karsh, B.-T. 2008. Workarounds

  6. The Long War and America’s Relationship With Its Military

    DTIC Science & Technology

    2008-03-23

    Koppel , “The Long Cost-Free War,” New York Times, 6 November, 2006, Sec 1A, p.21. 60 Gordon Lubold, “Few Americans Share Iraq War’s Sacrifices...Strategic Studies Institute, (May 2001): 21. 65 Koppel , 3. 66 Don Snider, “Dissent and the Strategic Leadership of the Military Professions,” Strategic

  7. Kennislacunes op het gebied van wapens en munitie in OVG (Knowledge Gaps in the Area of Weapons and Munitions in MOUT)

    DTIC Science & Technology

    2008-12-01

    Militaire activiteiten Tabel 4 koppelt een overzicht van relevante militaire activiteiten in OVG aan operationele effecten volgens [2]. De koppeling ...Divert, Deter 6 Beheersen van menigten Degrade, Control 7 Uitwerkingsgebied " 8 Nevenschade - 9 Eigen veiligheid Met de koppeling van activiteiten en

  8. Formula for Deterrence: The Challenges of Deterring Contemporary Threats to United States National Interests

    DTIC Science & Technology

    2009-02-01

    36. 26 Douglas Paal and Dr. Nancy Bernkopf Tucker, interview by Andrea Koppel , “China and Taiwan: An American Tightrope,” Transcript of Great...Armed Regional Adversaries. Santa Monica, CA: RAND Corp, 2008. Paal, Douglas and Tucker, Dr. Nancy Bernkopf. Interview by Andrea Koppel . “China

  9. 78 FR 47814 - Data Collection Available for Public Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ...: Dean Koppel, Assistant Administrator, 202-205-7322 dean.koppel@sba.gov Curtis B. Rich, Management Analyst, 202-205-7030 curtis.rich@sba.gov . Title: ``Certification for the Women-Owned Small Business.... Annual Burden: 24,400. Curtis Rich, Management Analyst. BILLING CODE 8025-01-P...

  10. 75 FR 73156 - Data Collection Available for Public Comments and Recommendations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ... developed by SBA, is used in the evaluation process. Title: ``SBA Application for Certificate of Competency... enhance the quality of the collection, to Dean Koppel, Assistant Administrator, Office of Policy...

  11. Interruption Practice Reduces Errors

    DTIC Science & Technology

    2014-01-01

    miscalculations ( Koppel et al., 2005). There are cases where the user (medical staff, MD, Nurse, etc.) forgets to complete the PCS which is to log off or...hl=en&lr=&id=JInZiZnUyicC&oi =fnd&pg=PA1&dq=to+err+is+human+institute+of+medicine&ots =hpKPPDbGR6&sig=7lEcQexi3gK6AHxHXgkwzsp7dJQ Koppel , R., Metlay

  12. Understanding Collagen Organization in Breast Tumors to Predict and Prevent Metastasis

    DTIC Science & Technology

    2010-09-01

    and ωz. For both the low- and high-NA case, D was chosen as 10µm2/s, approximately the experimental diffusion coefficient for 2000 kD fluorescein...Strickler, and W. W. Webb, Science, 248, 73 (1990). [3] D. Axelrod, D. E. Koppel, J. Schlessinger , E. Elson, and W. W. Webb, Biophys. J., 16, 1055 (1976...4] M. Edidin, M. Zagyansky, and T. Lardner, Science, 191, 466 (1976). [5] D. E. Koppel, D. Axelrod, J. Schlessinger , E. L. Elson, and W. W. Webb

  13. The total neutron cross section of liquid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    1999-12-01

    We have measured, using the pulsed neutron source ISIS, the total neutron cross section of liquid para-hydrogen in the vicinity of the triple point. The experimental results compare only qualitatively with the results of the Young and Koppel theory. However, a much better agreement is found once modifications are included in the model which effectively take into account the intermolecular interactions.

  14. The Impact of the Government Performance and Results Act (GPRA) on Two State Cooperative Extension Systems

    ERIC Educational Resources Information Center

    Baughman, Sarah; Boyd, Heather H.; Kelsey, Kathleen D.

    2012-01-01

    The research reported here examined the impact of the Government Performance and Results Act on accountability and evaluation activities in two state Cooperative Extension Systems. Accountability was examined using five dimensions from Koppell's (2005) framework. Findings indicated both Extension systems transferred accountability activities to…

  15. 76 FR 51469 - CSX Transportation, Inc.-Abandonment Exemption-in Beaver County, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Surface Transportation Board CSX Transportation, Inc.--Abandonment Exemption--in Beaver County, PA CSX..., between milepost PLK 0.0 and milepost PLK 2.39, in Koppel, Beaver County, Pa. The line traverses...

  16. The total neutron cross-section of an ortho-para mixture of gaseous hydrogen at 75K

    NASA Astrophysics Data System (ADS)

    Corradi, G.; Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    2004-07-01

    From the data of a transmission experiment we have extracted the total neutron cross-section of a sample of gaseous hydrogen (T=75.03K, p=84.8bar, n=8.42nm-3) with a thermodynamic equilibrium ortho-para content (48% ortho, 52% para). The experiment was carried out on the PEARL instrument operating at the ISIS pulsed neutron source. After an accurate data reduction, the neutron spectra have been analyzed in the framework of the Modified Young and Koppel (MYK) theory, which is a successful extension to interacting fluids of the original Young and Koppel model valid for a dilute gas of hydrogen molecules. The total cross-section calculated with MYK theory, whose unique unknown parameter-the mean kinetic energy of the molecular centre of mass-was obtained through an independent path integral Monte Carlo simulation, shows a satisfactory agreement with the experimental results.

  17. Decay of neutron pulses in graphite assemblies

    SciTech Connect

    Malik, U.; Kothari, L.S.

    1982-09-01

    A new neutron scattering kernel for graphite has been developed with the frequency distribution function generated by the authors using the unfolding technique. This has been used to study the decay of neutron pulses in different graphite assemblies. This kernel (with theta /SUB D/ = 2000 K) can give a slightly better explanation of the experimental results than those based on the Krumhansl and Brooks model or the Young and Koppel model of lattice vibrations.

  18. Transcripts of Regional Hearings, Seattle, Washington: Annex L to Adjusting to the Drawdown Report of the Defense Conversion Commission

    DTIC Science & Technology

    1992-09-24

    and technical societies , and the press. The budget for this project is S 106,360. The co-principal investigators will be Professor Philip Bereano of...Technology, arid Society (forthcoming, edited by S . Janasoff, et. al.); and "The Essential Tension in Science and Democracy," in the journal Social...Koppel Seattle Women Act for Peace/WSP 35 Presentation of Dr. Delore Zimmerman and Dean M. Henney MetaDynamics, Inc. 40 Presentation of Paul

  19. Measured Total Cross Sections of Slow Neutrons Scattered by Gaseous and Liquid 2H2

    NASA Astrophysics Data System (ADS)

    Atchison, F.; van den Brandt, B.; Bryś, T.; Daum, M.; Fierlinger, P.; Hautle, P.; Henneck, R.; Kirch, K.; Kohlbrecher, J.; Kühne, G.; Konter, J. A.; Pichlmaier, A.; Wokaun, A.; Bodek, K.; Kasprzak, M.; Kuźniak, M.; Geltenbort, P.; Giersch, M.; Zmeskal, J.; Hino, M.; Utsuro, M.

    2005-06-01

    The total scattering cross sections for slow neutrons with energies E in the range 300 neV to 3 meV for gaseous and liquid ortho-2H2 have been measured. The cross sections for 2H2 gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid 2H2, we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear 1/√(E') dependence at low energies for both states. A simple explanation for the liquid 2H2 cross section is offered.

  20. Deep inelastic neutron scattering in condensed hydrogen

    NASA Astrophysics Data System (ADS)

    Bafile, Ubaldo; Celli, Milva; Zoppi, Marco

    1996-02-01

    The neutron cross-section of molecular hydrogen that is measured by deep inelastic neutron scattering (DINS) is compared with two distinct models. One is a generalization of the molecular Young and Koppel model (1964) that takes into account the modification to the translational kinetic energy that is induced by quantum effects. The second model assumes a free particle wave function for the final state of the proton (C. Andreani et al., 1995). The comparison between these two models, and with the experimental results, provides information on the crossover between the molecular and atomic regime of hydrogen in DINS.

  1. Solute-solvent interactions measured by allerhand and schleyer's g parameter. application of this parameter to predict ν(gas) from solution values.

    NASA Astrophysics Data System (ADS)

    Somolinos, C.; Rodriguez, I.; Redondo, M. I.; Garcia, M. V.

    1986-03-01

    Carbonyl stretching band in N,N-dimethylformamide and benzophenone and sulfonyl stretching band in dimethylsulfoxide have been measured in solution in 37 solvents. Solvents induced frequency shifts on these bands have been used to calculate G solvent parameter following Allerhand and Schleyer's method. G scale has been extended to include some alcohols in it. Following the Koppel-Palm treatment G values have been correlated with non-specific and specific interaction terms. Results show that the contribution of non-specific interaction terms is predominant. G values have been used to predict ν(gas) of C=O stretching band in ethyl-chloroacetates from solution data.

  2. Neutron scattering kernel for solid deuterium

    NASA Astrophysics Data System (ADS)

    Granada, J. R.

    2009-06-01

    A new scattering kernel to describe the interaction of slow neutrons with solid deuterium was developed. The main characteristics of that system are contained in the formalism, including the lattice's density of states, the Young-Koppel quantum treatment of the rotations, and the internal molecular vibrations. The elastic processes involving coherent and incoherent contributions are fully described, as well as the spin-correlation effects. The results from the new model are compared with the best available experimental data, showing very good agreement.

  3. Alcoholysis of the 3-phenylpropyl ester of p-toluenesulfonic acid

    SciTech Connect

    Sendega, R.V.; Makitra, R.G.; Pirig, Ya.N.

    1987-01-01

    The kinetics of the interaction of 3-phenylpropyl-p-toluenesulfonate with 16 alcohols was investigated at 40-70/sup 0/C. The pseudo-first-order rate constants increased in the presence of alkali, in proportion to its concentration, which confirms the bimolecular mechanism of the reaction. The results obtained confirm the advisability of the joint use of the Taft and Koppel-Pal'm equations to generalize the data on the kinetics of solvolysis in alcohols, which play a dual role - reagent and solvent.

  4. Neoliberalism in a Conflict State: The Viability of Economic Shock Therapy in Iraq

    DTIC Science & Technology

    2004-06-01

    strategy’s success, at least in the near future. If not neoliberalism in its pure form, then what for Iraq.? Dani Rodrik , one of the more perceptive...Literature (September 2003): 885-99 and Dani Rodrik , "Understanding Policy Reform," Journal of Economic Literature (March 1996). 13. Naomi Koppel, "Iraq...1 (Winter 2002), p. 77 44. Sabre Aire Al-Saadi, "Iraq’s Post-War Economy: A Critical Review," Middle East Economic Survey, April 5, 2004. 45. Dani

  5. US EPA, Pesticide Product Label, , 06/12/1990

    EPA Pesticide Factsheets

    2011-04-14

    ... ClOIMl1I4 u~ TI'It 'OI-OW''', ,lp"'5 01 (loft·" •• . r.".'I'~II!'''S pr~.ct lOfll \\li!'hf'd ''''~1·1o(I1On1 :loI.'S ;>If·.·.tJPy .~, gof'C.·c~,·. 11 ".1 .'I~ ~"f1 ... sn,s TO I( tAU"'. ...

  6. Infantry Instructors’ Conference. 15-19 July 1963

    DTIC Science & Technology

    1963-01-01

    BEHAVIORAL AND SOCIAL SCIENCES P.O. BOX 2060. FORT ISENNING. GEORGIA 3105 8 August 1979 SUBJECT: S ipnent (l Docuiments D~ eenkle I k)ewle tiit11:l 1ll...Battalion and Brigade Communication Systems to include an orientation on-new items of communications equipment. 0925 - 0945 Coffee Break 0945 - 1005...division support command elements supporting the brigade. vii 0950 - 1010 Coffee Break 1010 - 1055 "Departmentof Nonresident Instruction" Scope: A

  7. Efficacy and Duration of Three Residual Insecticides on Cotton Duck and Vinyl Tent Surfaces for Control of the Sand Fly Phlebotomus papatasi (Diptera:Psychodidae)

    DTIC Science & Technology

    2013-06-01

    i,tN $tii$t’:l~r,,ry ~:o>r,lf»l un. JC"’’’ ~u<:ll ,·on•hH<lll <., <lUf f :’!lUII <. o’ ll",, r;y 111•’h. <::._,. !b d >xhl’ ’l :t•.-;u iAbl .., h

  8. Characteristic Based Methods for the Time-Domain Maxwell Equations

    DTIC Science & Technology

    1993-08-09

    2-D results on Cartesian frame demonstrated a potential for numerical efficiency improvement. 14. SUBJECT TERMS 15. NUMBER OF PAGES Time-domain...11 4 Discussion of Numerical Results ........................ 19 5 C onclusion...l ill tiit, pruIcIt a1lyis lder this’ Iranirwurk. Ilulilerical results it’lect tfi heIcst puss,’ibk 1)1(2pefon~lI liace of t he iiew aiiuiirical j

  9. Science and thinking: The write connection

    NASA Astrophysics Data System (ADS)

    Butler, Gene

    1991-09-01

    The effective use of writing in science instruction may open the way for students to grow in their ability to exercise higher order thinking skills (Bland & Koppel, 1988). Scinto (1986) makes a compelling case for writing as a means of stimulating thinking when he states: The production of written text demands more elaborate strategies of preplanning. Written language demands the conscious organization of ensembles of propositions to achieve its end. The need to manipulate linguistic means in such a conscious and deliberate fashion entails a level of linguistic self-reflection not called forth in oral discourse (p. 101). Science educators may find that the writing process is one technique to help them move away from the teacher-centered, textbook-driven science classroom of today, and move toward the realization of science education which will ensure that students are able to function as scientifically literate citizens in our contemporary society.

  10. The Jahn Teller and pseudo-Jahn Teller effect in the dark Ãstate of the nitrate radical NO3

    NASA Astrophysics Data System (ADS)

    Takematsu, Kana; Robichaud, David; Okumura, Mitchio; Stanton, John

    2007-03-01

    Despite its apparent simple molecular structure, the lowest electronic states of the nitrate radical NO3 remain poorly understood. In particular, the three lowest states of the radical provide a benchmark for testing models of the Jahn-Teller (JT) and pseudo-JT effects. The dark Ãstate of NO3 undergoes strong JT distortion, suggesting that models with only linear and quadratic vibronic couplings are inadequate. We present cavity ringdown (CRD) and integrated cavity output (ICOS) spectra of the forbidden A&˜circ; ^2E"<-X&˜circ; ^2A2' transition (preliminary report in Deev, et. al. J.Chem. Phys., 2005. 122:224305) and compare them to a simulation based on a model Hamiltonian developed by Koppel, Domcke and Cederbaum that incorporates both JT and PJT couplings. New insights into the pseudo-JT effect among the lowest states are gained by examination of intensity-borrowing mechanisms for the observed vibronic bands.

  11. New approximate orientation averaging of the water molecule interacting with the thermal neutron

    SciTech Connect

    Markovic, M.I.; Minic, D.M.; Rakic, A.D. . Elektrotehnicki Fakultet)

    1992-02-01

    This paper reports that exactly describing the time of thermal neutron collisions with water molecules, orientation averaging is performed by an exact method (EOA{sub k}) and four approximate methods (two well known and two less known). Expressions for the microscopic scattering kernel are developed. The two well-known approximate orientation averaging methods are Krieger-Nelkin (K-N) and Koppel-Young (K-Y). The results obtained by one of the two proposed approximate orientation averaging methods agree best with the corresponding results obtained by EOA{sub k}. The largest discrepancies between the EOA{sub k} results and the results of the approximate methods are obtained using the well-know K-N approximate orientation averaging method.

  12. Measured Total Cross Sections of Slow Neutrons Scattered by Gaseous and Liquid {sup 2}H{sub 2}

    SciTech Connect

    Atchison, F.; Brandt, B. van den; Brys, T.; Daum, M.; Fierlinger, P.; Hautle, P.; Henneck, R.; Kirch, K.; Kohlbrecher, J.; Kuehne, G.; Konter, J.A.; Pichlmaier, A.; Wokaun, A.; Bodek, K.; Kasprzak, M.; Kuzniak, M.; Geltenbort, P.; Giersch, M.; Zmeskal, J.; Hino, M.

    2005-06-03

    The total scattering cross sections for slow neutrons with energies E in the range 300 neV to 3 meV for gaseous and liquid ortho-{sup 2}H{sub 2} have been measured. The cross sections for {sup 2}H{sub 2} gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid {sup 2}H{sub 2}, we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear 1/{radical}(E{sup '}) dependence at low energies for both states. A simple explanation for the liquid {sup 2}H{sub 2} cross section is offered.

  13. The β-phosphorus hyperfine coupling constant in nitroxides: 6. Solvent effects in non-cyclic nitroxides.

    PubMed

    Audran, Gérard; Bosco, Lionel; Nkolo, Paulin; Bikanga, Raphael; Brémond, Paul; Butscher, Teddy; Marque, Sylvain R A

    2016-04-12

    In two recent articles (Org. Biomol. Chem., 2015 and 2016), we showed that changes in the phosphorus hyperfine coupling constant aP at position β in β-phosphorylated nitroxides can be dramatic. Such changes were applied to the titration of water in organic solvents and conversely of organic solvents in water. One of the molecules tested was a non-cyclic nitroxide meaning that a thorough investigation of the solvent effect on the EPR hyperfine coupling constant is timely due. In this article, we show that the aP of persistent non-cyclic β-phosphorylated nitroxides decrease with the normalized polarity Reichardt's constant E(N)T. The Koppel-Palm and Kalmet-Abboud-Taft relationships were applied to gain deeper insight into the effects influencing aN and aP: polarity/polarizability, hydrogen bond donor properties, and the structuredness of the cybotactic region.

  14. Spatial organisation of vegetation in water controlled landscapes: the role of vegetation dispersion strategies.

    NASA Astrophysics Data System (ADS)

    Thompson, S. E.; Katul, G.

    2007-12-01

    When investigating the spatial organization of biomass resulting from plant-water feedbacks in arid ecosystems, spatial movement of plants is generally represented as a diffusive processes. Diffusive representations of plant movement have two consequences: they fix the length scale of dispersion to the immediate vicinity of the parent plant, and thus cannot explicitly represent long distance dispersal; and they treat the local gradient of biomass as the determinant of the rate and direction of dispersal. An adaptation of an existing model (Rietkerk et al. 2002) is used to investigate the significance of these assumptions on predicted spatial distributions of vegetation. Model runs were conducted separately with a diffusive and a long-distance dispersive kernel for spatial movement and the resulting spatial organization of vegetation was contrasted. The results indicate that dispersion behavior strongly influences the spatial organization of vegetation in arid landscapes, destabilizing the regular spatial patterns often predicted by models utilizing diffusive representations of biomass movement. The model results provide insight into ecological hypotheses regarding the preponderance of short-range dispersion behavior observed in arid ecosystems, and suggest that this is a consequence of the highly organized nature of the soil water resource. Rietkerk, M., M. C. Boerlijst, F. van Langevelde, R. HilleRisLambers, J. van de Koppel, L. Kumar, H. H. T. Prins, and A. M. de Roos. 2002. Self-organization of vegetation in arid ecosystems. American Naturalist 160:524-530.

  15. Lattice dynamics and molecular rotations in solid hydrogen deuteride: Inelastic neutron scattering study

    NASA Astrophysics Data System (ADS)

    Colognesi, D.; Formisano, F.; Ramirez-Cuesta, A. J.; Ulivi, L.

    2009-04-01

    In the present paper we report inelastic neutron scattering measurements on solid low-pressure hydrogen deuteride at three different temperatures (between 4.5 and 15.6 K) using the time-of-flight spectrometers BRISP at ILL (France) and TOSCA-II at ISIS, RAL (UK). The measured double-differential cross sections give access to the proton component of the HD self-inelastic structure factor. Processed BRISP data were employed to verify the applicability of the generalized Young and Koppel model to solid HD in our kinematic range and to obtain the mean-square displacement of the molecular centers of mass. In addition, a large broadening of the first two rotational peaks was observed. A reasonable result for the density of phonon states from TOSCA-II data has been obtained, although a rigorous extraction was not possible, due to the overlap among the various spectral components. The intensity loss in the extracted density of phonon states was interpreted as the effect the phonon-roton resonance in solid hydrogen deuteride. Finally the two Bose-corrected moments of the HD phonon spectrum, related to the molecular mean-square displacement and mean kinetic energy, were simulated through a path integral Monte Carlo code. The former quantity was compared to the mentioned experimental estimates.

  16. The Infrared Spectra of BF_3 Cation and BF_2OH Cation Trapped in Solid Neon

    NASA Astrophysics Data System (ADS)

    Jacox, Marilyn E.; Thompson, Warren E.

    2010-06-01

    New, more detailed studies of the photoionization and Penning ionization of BF_3 trapped in solid neon have confirmed the earlier infrared spectroscopic identification of BF_2 and BF_2 cation and have yielded a revised assignment for the infrared absorptions of BF3 cation. The position of the absorption attributed to ν_3 of that molecule is consistent with the distortion of the ground-state cation from D3h symmetry because of strong vibronic interaction between levels of the Btilde ^2E^' state and E^' levels of the ~X ^2A_2^' ground state, as predicted by Haller and co-workers. The facile reaction of BF_3 with traces of H_2O desorbed from the walls of the vacuum system leads to the stabilization of sufficient BF_2OH for the identification of two vibrational fundamentals of BF_2OH cation. M. E. Jacox and W. E. Thompson, J. Chem. Phys. 102, 4747 (1995). E. Haller, H. Koppel, L. S. Cederbaum, W. von Niessen, and G. Bieri, J. Chem. Phys. 78, 1359 (1983).

  17. Microscopic self-dynamics in liquid hydrogen and in its mixtures with deuterium

    NASA Astrophysics Data System (ADS)

    Colognesi, D.; Celli, M.; Neumann, M.; Zoppi, M.

    2004-12-01

    We have measured the dynamic structure factor of liquid parahydrogen, pure and mixed with deuterium, in various thermodynamic conditions using incoherent inelastic neutron scattering. The experiments were carried out on TOSCA-II, a new time-of-flight, inverse-geometry, crystal-analyzer spectrometer. After an accurate data reduction, the high-energy parts of the neutron spectra recorded in backward scattering were studied through the modified Young and Koppel model, from which the mean kinetic energy values for a hydrogen molecule were estimated. In addition the low-energy parts of the neutron spectra recorded in forward scattering were analyzed in the framework of the Gaussian approximation and fitted through a Levesque-Verlet model for the velocity autocorrelation function. Thus various physical quantities are determined and compared with accurate path integral Monte Carlo simulations. Despite the excellent quality of these fits, the velocity autocorrelation functions derived from the forward-scattering data appear totally unable to properly describe the backward-scattering ones. These findings prove an unquestionable breakdown of the Gaussian approximation in semiquantum liquids. The present results appear of great interest and suggest further investigation on the limits of the widely used Gaussian approximation.

  18. Hydrogen self-dynamics in liquid H2-D2 mixtures studied through inelastic neutron scattering

    NASA Astrophysics Data System (ADS)

    Colognesi, Daniele; Bafile, Ubaldo; Celli, Milva; Neumann, Martin; Orecchini, Andrea

    2015-07-01

    We have measured the dynamic structure factor of liquid para-hydrogen mixed with normal deuterium (T =20 K ) at two different concentration levels using incoherent inelastic neutron scattering. This choice has been made since the presence of D2 modifies the self-dynamics of H2 in a highly nontrivial way, acting both on its pseudophononic and its diffusive parts in a tunable way. After an accurate data reduction, recorded neutron spectra were studied through the modified Young and Koppel model and the H2 center-of-mass self-dynamics structure factor was finally extracted for the two mixtures. Some physical quantities (i.e., self-diffusion coefficient and mean kinetic energy) were determined and compared with accurate quantum calculations, which, in addition, also provided estimates of the velocity autocorrelation function for the H2 centers of mass. These estimates, in conjunction with the Gaussian approximation, were used to simulate the H2 center-of-mass self-dynamics structure factor in the same range as the experimental one. The agreement between measured and calculated spectra was globally good, but some discrepancies proved the unquestionable breakdown of the Gaussian approximation in these semiquantum systems at a level comparable to that already observed in pure liquid para-hydrogen.

  19. Direct experimental access to microscopic dynamics in liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Celli, M.; Colognesi, D.; Zoppi, M.

    2002-08-01

    We have obtained the double-differential incoherent neutron scattering cross section of liquid and solid parahydrogen in various thermodynamic conditions using TOSCA, a time-of-flight, inverse geometry, crystal analyzer spectrometer, operating at the pulsed neutron source ISIS. The measured cross section provides direct experimental access to the self part of the center-of-mass inelastic structure factor of the parahydrogen molecules in the system. Data have been corrected for the experimental effects and then analyzed in the framework of the Young-Koppel model and the Gaussian approximation. The velocity autocorrelation functions and their energy spectra have been obtained from a fitting procedure, making use of the quantum generalized Langevin equation and of model memory functions, and finally compared to the most recent results of both molecular centroid dynamics and self-consistent quantum mode-coupling theory. Some dynamic quantities were also related to simple equilibrium properties and simulated through a standard path integral Monte Carlo code. Results are very interesting but still urge for further developments of theoretical and dynamic simulation approaches, as well as for more extensive experimental efforts.

  20. Lattice vibrations of para-hydrogen impurities in a solid deuterium matrix: An inelastic neutron scattering study

    NASA Astrophysics Data System (ADS)

    Colognesi, D.; Celli, M.; Ramirez-Cuesta, A. J.; Zoppi, M.

    2007-11-01

    In the present study, we report inelastic neutron scattering measurements from para-hydrogen defects in solid normal deuterium at three different concentrations (between 3% and 11%) using the time-of-flight spectrometer TOSCA-II. The measured double-differential cross sections give access to the self-inelastic structure factors for the H2 centers of mass. Corrected experimental data, analyzed through the Young-Koppel model and the Gaussian approximation, are transformed into defect densities of phonon states, which come out to be broad, structured, and nearly concentration independent. Two experimentally determined Bose-corrected spectral moments are found to be in agreement with independent estimates, providing a strong validation of our data reduction procedure. Subsequently, experimental phonon spectra are compared to three calculations, namely, a simple harmonic model at infinite dilution, a more advanced harmonic model with concentration effects, and finally a lattice dynamics simulation based on self-consistent phonon and coherent potential approximations. However, while the first part of the defect spectral density, attributed to the propagating modes, turns out to be roughly explained, the localized part is properly described by none of these models, except for its mean frequency position. The large overall width appears so far impossible to be reproduced, representing a challenge for the physicists involved in quantum dynamics simulations.

  1. High-temperature burner-duct-recuperator system evaluation. Annual report, October 1981-September 1982

    SciTech Connect

    Not Available

    1984-01-01

    A project to design, construct, install, and evaluate a high-temperature burner-duct-recuperator (HTBDR) system is described. The high-temperature recuperator is to be capable of delivering 2000/sup 0/F (1800/sup 0/F minimum) preheated combustion air to a high-temperature burner designed for the combustion system of a steel mill soaking pit. The evaluation site is located at the Koppel, Pennsylvania, steel-making facility of the B and W Tubular Products Group. The purpose of the project is to advance the state-of-the-art in industrial waste heat utilization by developing an HTBDR system that is both technically and economically acceptable to industry. The system designed by B and W intended to operate in flue gas streams of 2500/sup 0/F (maximum) that contain contaminants from hot topping compounds and scale (iron oxide). This report describes the efforts in the first year of the project, which includes the design of the HTBDR system, flue exposure testing, and an energy audit of the host site. An interactive, interdisciplinary team was utilized to design the HTBDR system. The design effort of each technical discipline is presented in detail in sections 1 to 7 of this report including: ceramic materials characterization; system mechanical design; process control and instrumentation; thermal and fluid flow; applied mechanics (stress analysis); flow-induced vibration analysis; HTBDR burner development, and HTBDR and energy audit.

  2. High temperature burner-duct-recuperator system evaluation

    SciTech Connect

    Parks, W.P. Jr.; DeBellis, C.L.

    1989-08-01

    The Babcock Wilcox Company (B W) has completed a program to design, construct, install, and field test a ceramic-based high-temperature burner-duct-recuperator (HTBDR) in an industrial setting. The unit was capable of operating in corrosive, high temperature (2250{degree}F) flue gas streams. The HTBDR was successfully tested in a steel soaking pit at B W's Tubular Products Division in Koppel, PA. During the 1400 hour operation prior to plant closing, the ceramic stage performed well with no material related problems or air-to-flue leakage. The maximum preheat air produced was 1425{degree}F with a flue gas temperature of 2170{degree}F. Measured fuel savings of 17--24% were obtained over the previous recuperated (metallic heat exchanger) system. This projects to savings of 41% for an unrecuperated furnace. A simple payback analysis indicated acceptable payback for installation in unrecuperated furnaces but unacceptable payback for recuperated furnaces at today's low gas prices. In both cases return on investment is high over a ten year projected life expectancy. 14 refs., 67 figs., 16 tabs.

  3. Forgetting our personal past: socially shared retrieval-induced forgetting of autobiographical memories.

    PubMed

    Stone, Charles B; Barnier, Amanda J; Sutton, John; Hirst, William

    2013-11-01

    People often talk to others about their personal past. These discussions are inherently selective. Selective retrieval of memories in the course of a conversation may induce forgetting of unmentioned but related memories for both speakers and listeners (Cuc, Koppel, & Hirst, 2007). Cuc et al. (2007) defined the forgetting on the part of the speaker as within-individual retrieval-induced forgetting (WI-RIF) and the forgetting on the part of the listener as socially shared retrieval-induced forgetting (SS-RIF). However, if the forgetting associated with WI-RIF and SS-RIF is to be taken seriously as a mechanism that shapes both individual and shared memories, this mechanism must be demonstrated with meaningful material and in ecologically valid groups. In our first 2 experiments we extended SS-RIF from unemotional, experimenter-contrived material to the emotional and unemotional autobiographical memories of strangers (Experiment 1) and intimate couples (Experiment 2) when merely overhearing the speaker selectively practice memories. We then extended these results to the context of a free-flowing conversation (Experiments 3 and 4). In all 4 experiments we found WI-RIF and SS-RIF regardless of the emotional valence or individual ownership of the memories. We discuss our findings in terms of the role of conversational silence in shaping both our personal and shared pasts.

  4. Building consensus about the past: schema consistency and convergence in socially shared retrieval-induced forgetting.

    PubMed

    Stone, Charles B; Barnier, Amanda J; Sutton, John; Hirst, William

    2010-02-01

    A large body of literature on "within-individual retrieval-induced forgetting" (WI-RIF; Anderson, Bjork, & Bjork, 1994) shows that repeatedly retrieving some items, while not retrieving other related items, facilitates later recall of the practised items, but inhibits later recall of the non-practised related items. This robust effect has recently been extended to "socially shared retrieval-induced forgetting" (SS-RIF; Cuc, Koppel, & Hirst, 2007). People who merely listen to a speaker retrieving some, but not other, items-even people participating as speakers or listeners in conversations-show the same facilitation and inhibition. We replicated and extended the SS-RIF effect with a structured story (Experiment 1) and in a free-flowing conversation about the story (Experiment 2). Specifically, we explored (1) the degree to which participants subsequently form a coherent "collective memory" of the story and (2) whether schema consistency of the target information influences both WI-RIF and SS-RIF. In both experiments, speakers and listeners showed RIF (that is, WI-RIF and SS-RIF, respectively), irrespective of the schema consistency of the story material. On final recall, speakers and listeners described similar renderings of the story. We discuss these findings in terms of the role of "silences" in the formation of collective memories.

  5. Multistate vibronic interactions in difluorobenzene radical cations. II. Quantum dynamical simulations.

    PubMed

    Faraji, Shirin; Meyer, H-D; Köppel, Horst

    2008-08-21

    The multistate vibronic dynamics in the X-D electronic states of all three difluorobenzene radical cations are investigated theoretically by an ab initio quantum dynamical approach. The vibronic coupling scheme and the ab initio values of the system parameters are adopted from Paper I [S. Faraji and H. Koppel, J. Chem. Phys. 129, 074310 (2008)]. Extensive calculations by wave-packet propagation have been performed with the aid of the multiconfiguration time-dependent Hartree method. Five coupled electronic potential energy surfaces and 10 (11 in the case of the orthoisomer) vibrational degrees of freedom have been included in these calculations. The nonadiabatic interactions lead to the restructuring of the photoelectron spectral envelopes. Ultrafast internal conversion processes within the electronic manifolds in question demonstrate the strength of the nonadiabatic coupling effects and complement the analogous findings for the electronic spectra. The internal conversion dynamics is characterized by a stepwise transfer of the electronic population to the lowest electronic state on a time scale of femtoseconds to picoseconds. A difference between the three isomers is found to be related to the weaker interaction between the sets of X-A and B-C-D states (with high-energy conical intersections) in the meta isomer, as compared to the other isomers. The implications of these findings for the qualitative understanding of the fluorescence dynamics of fluorinated benzene radical cations are discussed.

  6. 2,3-Diphosphoglycerate and ATP dissociate erythrocyte membrane skeletons.

    PubMed

    Sheetz, M P; Casaly, J

    1980-10-25

    Since ATP and 2,3-diphosphoglycerate cause an increase in the lateral mobility of integral membrane proteins in the erythrocyte (Schindler, M., Koppel, D., and Sheetz, M. P. (1980) Proc. Natl. Acad. Sci. U. S. A. 77, 1457-1461), we have studied their effects on the membrane skeletal complex or shell (composed of spectrin, actin, and bands 4.1 (78,000 daltons) and 4.9 (50,000 daltons)) and its interaction with the erythrocyte membrane. Both phosphate compounds dissociated the delipidated shell complex, with half-maximal dissociation at 2.5 mM 2,3-diphosphoglycerate and 8 mM ATP, whereas equivalent concentrations of EDTA did not. Concomitant with complex dissociation, spectrin was solubilized but band 4.1 and actin remained in a complexed or polymeric form. When proteins which were involved in linking spectrin to the membrane were present on the shell, higher concentrations of the phosphate compounds still dissociated the complex but less spectrin was solubilized. Treatment of erythrocyte membranes with the same phosphate compounds caused membrane vesiculation but no proteins were solubilized. We suggest that ATP and 2,3-diphosphoglycerate, at concentrations which are normally present in erythrocytes, can weaken associations in the shell but will not dissociate the complex from membrane attachment sites.

  7. The member of the Academy H.P. Keres and the Relativity theory in Estonia

    NASA Astrophysics Data System (ADS)

    Kuusk, P.; Muursepp, P. V.; Piir, Ivar

    1987-10-01

    The first popular lecture on the Einstein theory of relativity was given in Estonia already in 1914 by Jaan Sarv (1877-1954)[1],afterwards a professor of mathematics at the Tartu University. The first student courses on special relativity were delivered by Professor of Mathematics Juri Nuut (1892-1952): non-Euclidean geometry (1930), the mathematical theory of relativity (1932/1933),the Lorenz transformations (1937). His own research work concerned the Lobachevsky geometry [7] and its application to cosmology [6]. Harald Keres qraguated from the Tartu University in 1936. He gave the first student course on general relativity (based on books [11-14]in 1940.In 1942,he got the dr.phil.nat degree form the Tartu University for his theses "Raum und Zeit in der allgemeinen Relativitatstheorie". The degree of the doctor of mathematical and physical sciences was confirmed by VAK (the All-Union Higher Attestation Commission) in 1949.In this period, he got aquainted with the leading Soviet scientists working on General Relativity, prof.V.A.Fock,Prof.D.D.Ivanenko,Prof.A.Z.Petrov,and Prof.M.F.Shirokov. After World War two all-union university courses were introduced in Tartu State University. According to the curriculum of the course the special theory of relativity is a part of electrodynamics obligatory for all students of the department of Physics. From 1947 till 1985 this course was delivered by Prof.PaulKard(1914-1985).He also published a number of text-books on the subject [15-19]. The general theory of relativity was read by Prof.H.Keres in 1951-1960 and later by his pupils R.Lias and A.Koppel [20-23] as a special course for students specializing in theoretical Physics. The first PHD-s in general relativity were made by R.Lias [27](1954) and I.Piir [28] (1955). In 1961, Prof.H.Keres was elected a member of the Academy of Sciences of the Estonian S.S.R. He left the TArtu State University and began to work in the Institute of Physics as the head of the Department of

  8. Cold-moderator scattering kernel methods

    SciTech Connect

    MacFarlane, R. E.

    1998-01-01

    An accurate representation of the scattering of neutrons by the materials used to build cold sources at neutron scattering facilities is important for the initial design and optimization of a cold source, and for the analysis of experimental results obtained using the cold source. In practice, this requires a good representation of the physics of scattering from the material, a method to convert this into observable quantities (such as scattering cross sections), and a method to use the results in a neutron transport code (such as the MCNP Monte Carlo code). At Los Alamos, the authors have been developing these capabilities over the last ten years. The final set of cold-moderator evaluations, together with evaluations for conventional moderator materials, was released in 1994. These materials have been processed into MCNP data files using the NJOY Nuclear Data Processing System. Over the course of this work, they were able to develop a new module for NJOY called LEAPR based on the LEAP + ADDELT code from the UK as modified by D.J. Picton for cold-moderator calculations. Much of the physics for methane came from Picton`s work. The liquid hydrogen work was originally based on a code using the Young-Koppel approach that went through a number of hands in Europe (including Rolf Neef and Guy Robert). It was generalized and extended for LEAPR, and depends strongly on work by Keinert and Sax of the University of Stuttgart. Thus, their collection of cold-moderator scattering kernels is truly an international effort, and they are glad to be able to return the enhanced evaluations and processing techniques to the international community. In this paper, they give sections on the major cold moderator materials (namely, solid methane, liquid methane, and liquid hydrogen) using each section to introduce the relevant physics for that material and to show typical results.

  9. Aspects of conical intersections: Dynamics, bound states embedded in the continuum and short-lived electronic states

    NASA Astrophysics Data System (ADS)

    Cederbaum, Lorenz

    2007-03-01

    Conical intersections are omnipresent in polyatomic molecules and their presence gives rise to the most severe breakdown of the Born-Oppenheimer approximation. Several general aspects of conical intersections and of the dynamics through them will be addressed. Particular attention will be paid to the question what happens to the potential energy surfaces if the electronic states are metastable. In addition, it is shown that nuclear dynamics on coupled potential surface can lead to bound states embedded in the continuum. Non-Born-Oppenheimer effects are responsible for the binding of these states. Once the Born-Oppenheimer approximation is introduced, these states at best become resonances which decay via potential tunnelling. The tunnelling is completely suppressed by the coupling between the electronic states. Another important issue which will be touched upon is dynamics in the presence of conical intersections in macrosystems. Here, the number of modes is extremely large and, nevertheless, their impact close to the intersections cannot be neglected. It is shown that effective modes can be derived which reproduce exactly the short-time dynamics of the whole macrosystem at low cost. Numerical examples are given. References: H. K"oppel, W. Domcke and L.S. Cederbaum, Adv.Chem.Phys. 57, 59 (1984) G.A. Worth and L.S. Cederbaum, Annu-Rev.Phys.Chem. 55, 127 (2004) L.S. Cederbaum, R.S. Friedman, V.M Ryaboy and N. Moiseyev, Phys.Rev.Lett. 90, 013001 (2003) S. Feuerbacher, T. Sommerfeld and L.S. Cederbaum, J.Chem.Phys. 120, 3201 (2004) L.S. Cederbaum, E. Gindensperger and I. Burghardt, Phys.Rev.Lett. 94, 113003 (2005)

  10. Chemical Binding Effects in Neutron Resonance Scattering and Absorption.

    NASA Astrophysics Data System (ADS)

    Shamaoun, Adib Iskandar

    The Doppler broadening of neutron absorption and scattering resonances is an effect of considerable importance in calculating reactor parameters. This broadening is known to depend upon the state of the atom from which the scattering of the neutron occurs. This dependence is called the chemical binding effect. A key assumption in the usual computations of Doppler broadening is to ignore the dependence of the total resonance width on the chemical binding state of the compound nucleus. This is an excellent approximation for the gamma line. We derive an expression for the neutron line width as a function of the energy of the compound nucleus for an ideal gas. The influence of energy on the width with energy is examined at two different temperatures 4K and 1000K. It is found that these effects are very small, of the order of 10^{4-} . The assumption of constancy of the resonance width is thus shown to be a good approximation for the neutron line width. Also we examine the influence of the crystalline binding on the 6.67 eV resonance energy of U-238 line shape in uranium carbide and uranium dioxide. This model treats the crystal as a gas with an effective temperature and an effective mass determined by harmonic crystal phonon spectrum developed by Koppel and Houston. Based on this model, the line shape of U-238 is Gaussian plus a recoilless part. We also compute the broadening using a harmonic crystal model. As the temperature of U-238 target is decreased, disagreement between the two models becomes pronounced. However the results agree in the limiting case of high temperature. As the nucleus becomes more tightly bound, shifts in the resonance peak to lower energies are also observed. A general formula for the differential scattering cross section is developed starting from the transition probability (T-matrix). The formalism is applied to the gas and harmonic crystal models to determine the chemical binding effect. Although the resonance broadening is determined in

  11. SMART-1 SPEDE: Results and Legacy after 10 Years

    NASA Astrophysics Data System (ADS)

    Schmidt, Walter; Mälkki, Anssi

    2014-05-01

    sensor area treatment was optimized for SPEDE and used in all subsequent Langmuir probe designs of IRF/Uppsala. The algorithm implemented inside the SPEDE on-board software to analyze the plasma wave measurements was optimized during the SMART-1 mission and later uplinked to the ESA Rosetta spacecraft lander Philae, where it is now used to analyze and compress the data of the permittivity probe, also used as a plasma wave monitor with W.Schmidt as PI. The experience gained from the FPGA-implementation of a self-developed processor was later used in preparation of ESA's ExoMars 2016 pressure sensor controller and the Swedish plasma instrument LINA for a Russian Lunar mission as well as for the ESA JUICE mission to the Jupiter system. Reference: [1] Mälkki, A., Schmidt, W., Laakso, H., Grard, R., Escoubet, C.P., Wahlund, J.-E., Blomberg, L., Marklund, G. and Johlander, B., 2003: The SPEDE experiment on SMART-1: Instrument, mission, and science objectives. Geophysical Research Abstracts, Vol 5., 10004, 2003. [2] Mälkki, A., Schmidt, W., Laakso, H., Johlander, B., Wahlund, J.E., Blomberg, L., Marklund, G., Grard, R., Escoubet, C.P. and Lebreton, J.P., 2004: First results from SMART-1/ SPEDE plasma experiment. European Geophysical Union EGU-2004, EGU04-A-02543. Invited oral presentation [3] Mälkki, A., Schmidt, W., Genzer, M., Merikallio, S., Laakso, H., Gonzales del Amo, J., Estublier, D., Gengembre, E., Hilgers, A., Capacci, M., Koppel, C. and Tajmar, M., 2005: Spacecraft-plasma interaction analysis using data from SPEDE on SMART-1. 10th Scientific Assembly of IAGA, Toulouse, France, July 2005, paper IAGA2005-A-01401 [4] Mälkki, A., Schmidt, W., Kallio, E. and Merikallio, S., 2006: Interaction of Solar Wind With the Moon: Results From Hybrid Modeling and the SPEDE Instrument on SMART-1. Geophysical Research Abstracts, Vol. 8, 07632, 2006 [5] M.Backrud, 2007: Evaluation of the SPEDE instrument on SMART-1, Royal Institute of Technology (KTH) Report - TRITA-EE 2007:023

  12. EDITORIAL: Special issue on applied neurodynamics: from neural dynamics to neural engineering Special issue on applied neurodynamics: from neural dynamics to neural engineering

    NASA Astrophysics Data System (ADS)

    Chiel, Hillel J.; Thomas, Peter J.

    2011-12-01

    directly descended from the analysis of the Hodgkin and Huxley equations in FitzHugh and Nagumo's early work. Mathematicians became increasingly interested in biological problems in general, and in the function of the nervous system in particular, during the latter part of the twentieth century. The natural tool for describing more complex neural systems whose patterns of activity unfold in time was nonlinear dynamical systems theory. Classic work from such investigators as Kolmogorov, Arnol'd, Moser, Malkin, Andronov, Hopf, Birkhoff, Hartman and others (reviewed in Izhikevich 2006) served as the basis for understanding the dynamics of neural models such as the coupling of oscillators for rhythmic behavior, leading to work such as that of Koppell and Ermentrout on the lamprey swimming system (Kopell and Ermentrout 1986, 1990), based on earlier models of Cohen et al (1982). Exploration of nonlinear interactions in neuronal populations, especially those that might be related to vision, led to the development of the Wilson-Cowan equations in the 1970s (Wilson and Cowan 1972, 1973). The advent of increasingly powerful personal computers also made it feasible to combine theoretical analyses with extensive numerical investigations of nonlinear dynamical systems. An important and influential example of such work was the detailed bifurcation analysis of Morris and Lecar's two-dimensional model of nonlinear dynamical behavior in the giant muscle fiber of the Pacific barnacle Balanus nubilis (Morris and Lecar 1981), done by Rinzel and Ermentrout in the late 1980s (Rinzel and Ermentrout 1989). The mathematical analysis of bursting behavior based on decomposition of a dynamical system into fast and slow subsystems, an application of Fenichel's geometric singular perturbation theory (Fenichel 1979, Jones 1995), continues to play an important role. Recent work on dynamical analyses of neurons and neural circuits is described in Izhikevich's recent book (Izhikevich 2006), which is based