Note: This page contains sample records for the topic coster-kronig transitions from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

X-Ray Fluorescence Yields, Auger, and Coster-Kronig Transition Probabilities  

Microsoft Academic Search

The present status of the field of fluorescence yields, radiationless (Auger and Coster-Kronig) and radiative transition probabilities is summarized. Tables of experimental and theoretical results are included, and tables of \\

Walter Bambynek; Bernd Crasemann; R. W. Fink; H.-U. Freund; Hans Mark; C. D. Swift; R. E. Price; P. Venugopala Rao

1972-01-01

2

The Coster-Kronig process used to study the transition of metal nanoclusters into a nonmetallic state  

Microsoft Academic Search

The results of an experimental study of the Coster-Kronig process in copper nanoclusters obtained by a pulsed laser deposition\\u000a technique are presented. It is established that the Kster-Krnig process probability depends on the cluster size and is determined\\u000a by the possibility of a transition of the metal cluster into a state in which copper exhibits no metallic properties.

V. D. Borman; X. Ch. Lai; M. A. Pushkin; V. N. Tronin; V. I. Troyan

2002-01-01

3

Probing electron correlation, charge transfer, and Coster-Kronig transitions at the 3d and 4d thresholds of Nd by resonant inelastic scattering  

NASA Astrophysics Data System (ADS)

Soft x-ray emission near the 3d-4f and 4d-4f thresholds of Nd2O3 is studied with monochromatic synchrotron radiation excitation. At excitation energies above the MIV threshold, we observe Coster-Kronig enhanced fluorescence from the refill of the 3d hole via the 5p and 4f channel. Fluorescence occurs mainly due to transitions in which charge-transfer provides additional 4f electrons. Resonant inelastic scattering dominates the emission process and we observe two energy loss features at 2.3 and 21 eV, which are due to net transitions within the 4f shell (4f3-->4f3) and 5p64f3-->5p54f4, respectively. The emission spectra resulting from excitations at various energies through the 3d and 4d thresholds were compared and a number of differences were found. Our atomic calculations are in excellent agreement with the experimental results indicating strong localization and a low degree of correlation of the 4f electrons.

Moewes, A.; Ederer, D. L.; Grush, M. M.; Callcott, T. A.

1999-02-01

4

Theory of Coster-Kronig preceded Auger processes in solids  

SciTech Connect

We propose the foundations of an extended Auger line-shape analysis of solids aiming to include three-hole features such as the ones due to core-valence-valence Auger decays following Coster-Kronig transitions. In transition metals, such features show up as intense high binding energy satellites of the diagrammatic core-valence-valence lines. Our theory is grounded on the full one-step approach, but to keep the complications to a minimum, in the present exploratory paper, the valence band is assumed fully below the Fermi level. In this way, explicit model calculations can be confidently based on a three-step approach. The line-shape analysis then amounts to compute a three-body Green's function, which, however, is much less known than one- and two-body ones. Our treatment covers the whole range between weak and strong correlations. Furthermore, we show that the relevant physics can be captured by a transparent, computationally simple closed formula. We find that, in general, the satellites cover separated spectral regions with three-hole multiplets, shifted and broadened two-hole features, and distorted bandlike continua.

Cini, Michele; Ugenti, Simona [Dipartimento di Fisica, Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, Via E. Fermi 40, 00044 Frascati (Italy); Perfetto, Enrico [Unita CNISM, Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Stefanucci, Gianluca [Dipartimento di Fisica, Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy)

2007-11-15

5

Fluorescence yields and Coster-Kronig probabilities for the atomic L subshells. Part II: The L1 subshell revisited  

SciTech Connect

Our recently recommended values for the L1 subshell fluorescence yield {omega}{sub 1} and Coster-Kronig probabilities f{sub 13} and f{sub 12} in the atomic number range 64 {<=} Z {<=} 92 are re-assessed in the light of new experimental data. Special attention is paid to the regions of atomic number in which discontinuities arise due to the onset of L1L2N1, L1L3M4, and L1L3M5 transitions. Attention is drawn to large scatter and to systematic differences in the data from different experimental techniques, both of which result in large uncertainties being attached to the recommended values. The urgent need for additional refined measurements is emphasized.

Campbell, J.L. [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ont., N1G 2W1 (Canada)], E-mail: jlc@physics.uoguelph.ca

2009-01-15

6

Core-hole induced charge transfer and Coster-Kronig enhanced fluorescence at the 3d threshold of lanthanum studied by resonant inelastic scattering  

NASA Astrophysics Data System (ADS)

Soft x-ray emission near the 3d threshold of La is studied with synchrotron radiation. At excitation energies above the MIV edge we observe Coster-Kronig enhanced fluorescence that refills the 3d hole via 5p and 4f electrons. We find a new delayed onset of the fluorescence as the 7.5-eV inelastic scattering evolves into 3d-4f emission about 8 eV above the absorption threshold, which we attribute to the energy required to produce a charge-transfer hole. The 16.3-eV Raman-scattering loss is due to a net transition of a 5p electron into a 4f orbit. The results are compared with our calculations.

Moewes, A.; Stadler, S.; Winarski, R. P.; Ederer, D. L.; Grush, M. M.; Callcott, T. A.

1998-12-01

7

Line-shape effects on the determination of Coster-Kronig probabilities using Si(Li) x-ray detectors  

SciTech Connect

The great majority of measured values of the Coster-Kronig probability [ital f][sub 23] derive from x-ray coincidence experiments using radionuclide sources or from synchrotron-radiation excitation of thin foils. Very little attention has been paid in published work to the role of line-shape effects and satellites in the x-ray spectra that are obtained. It is shown that this neglect can influence [ital f][sub 23] values derived from such measurements. This may explain in part the well-established trends for measured [ital f][sub 23] values to fall below the theoretical predictions for elements with atomic number [ital Z][lt]90 and to fall above when [ital Z][gt]92. In elemental analysis techniques based upon x-ray emission spectroscopy, where a database of atomic parameters such as Coster-Kronig probabilities is used, the same approximations are made in treating the spectra. Until a more sophisticated approach to spectrum reduction is developed, it may be preferable in this context to use nominal'' Coster-Kronig probabilities derived from experiment in preference to theoretical values.

Papp, T.; Campbell, J.L.; Raman, S. (Guelph-Waterloo Program for Graduate Work in Physics, University of Guelph, Guelph, Ontario, N1G2W1 (Canada) Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI) Debrecen, H-4001, Pf.51 (Hungary) Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States))

1994-02-01

8

M{sub i} (i = 1-5) subshell fluorescence and Coster-Kronig yields for elements with 67 {<=} Z {<=} 92  

SciTech Connect

A complete set of the M{sub i} (i = 1-5) subshell fluorescence and Coster-Kronig (CK) yields has been generated by interpolation for elements with 67 {<=} Z {<=} 92 from the Dirac-Hartree-Slater (DHS) model based values tabulated for a limited number of elements, considering the cutoff/onset of different CK transitions in accordance with the CK transition energies evaluated in the present work. The CK transition energies have been deduced from tabulated values of the Dirac-Hartree-Fock-Slater model based neutral atom binding energies [K. Huang, M. Aoyagi, M.H. Chen, B. Crasemann, H. Mark, At. Data Nucl. Data Tables 18 (1976) 243] and the L{sub i} (i = 1-3) subshell CK transition energies [M.H. Chen, B. Crasemann, K. Huang, M. Aoyagi, H. Mark, At. Data Nucl. Data Tables 19 (1977) 97] in order to establish the cutoff/onset of different CK transitions at specific atomic numbers. A second set of the M{sub i} (i = 1-5) subshell fluorescence yields have also been deduced using radiative widths computed from the Dirac-Fock (DF) model based X-ray emission rates, and the total widths reevaluated to incorporate the DF model based radiative widths in place of those based on the DHS model. Further, the CK-corrected ({nu}{sub i}) and average fluorescence ({omega}{sub M}) fields, which are experimentally important, have been evaluated from the generated set of CK yields and two sets of fluorescence yields.

Chauhan, Yogeshwar [University College of Engineering, Punjabi University, Patiala 147002 (India); Puri, Sanjiv [University College of Engineering, Punjabi University, Patiala 147002 (India)], E-mail: sanjivpurichd@yahoo.com

2008-01-15

9

Coster-Kronig electrons from the autoionizing Rydberg states of 2 MeV u-1 Si5+ ions excited through a thin C-foil target  

NASA Astrophysics Data System (ADS)

Several peaks have been observed, in the electron energy range up to 20 eV, due to Coster-Kronig electrons from the autoionizing Rydberg states emitted from 2 MeV u-1 Si5+ ions excited through a carbon foil. To obtain a better understanding of these low-energy electron spectra and their production mechanisms, we synthesize the expected electron spectrum which is compared with the observed electron spectrum. Two theoretical methods, namely the perturbation theory of Z-expansion (MZ code) and the multiconfiguration Hartree-Fock method (Cowan code), are used to calculate the necessary Auger electron energies and emission rates. It has been found that the 1s22pnl-1s22s 2S and 1s22s2pnl-1s22s2 1S decays give the most significant contributions to the observed electron spectrum from threshold up to the 20 eV region. The synthetic electron spectra have also been found to reproduce the observed electron spectra quite nicely when the charge distributions of the projectile Si ions after thin carbon foils are taken into account.

Sataka, M.; Imai, M.; Kawatsura, K.; Komaki, K.; Tawara, H.; Vasilyev, A.; Safronova, U. I.

2002-01-01

10

Angular momentum distributions of autoionizing states produced in 1.5 MeV C(sup q+) + C(sub foil) and C(sup q+) + He collisions.  

National Technical Information Service (NTIS)

Using the method of zero-degree Auger spectroscopy, we have measured electrons emitted in the decay of autoionizing Rydberg states. Electron energies from Coster-Kronig transitions in C(sup 2+) were measured for 1.5 - 3 MeV C(sup q+) + C(sub foil) collisi...

N. Stolterfoht S. Andriamonje J. N. Scheurer D. Bertault J. F. Chemin

1988-01-01

11

Introduction to energy-dispersive x-ray fluorescence analysis  

Microsoft Academic Search

The physical principles of energy dispersive x-ray fluorescence analysis are discussed. A phenomenological description of atomic excitation and the subsequent radiation of x rays on which the physical principles are built, is presented. The atomic shell structure and nomenclature, x-ray nomenclature and energies, x-ray intensities and fluorescence yields, and a brief description of the competing Auger and Coster-Kronig transitions are

1978-01-01

12

Atomic structure calculations of KLL Auger spectra from highly charged ion-solid-surface collisions  

Microsoft Academic Search

Systematic atomic structure calculations of KLL Auger electron spectra from ``hollow'' atom configurations 1s2l23lZ-3 are performed for atomic numbers 6<=Z<=10. In comparison with the corresponding 1s2l2 Li-like configurations it is shown that the additional Z-3 M electrons, apart from taking part in LLM Coster-Kronig transitions, can be regarded basically as mere spectator electrons, neither severely influencing the peak structure due

S. Schippers; J. Limburg; J. Das; R. Hoekstra; R. Morgenstern

1994-01-01

13

M Sub-Shell Cross Sections For 75-300 keV Proton Impact On W, Pt And Pb  

SciTech Connect

M sub-shell x-ray production cross sections from 75-300 keV proton bombardment of thick elemental targets of W, Pt, and Pb were measured and compared with ECPSSR and relativistic RPWBA-BC cross sections using different data bases of fluorescence yields, Coster-Kronig factors, and x-ray transition rates. With a few exceptions, the differences between the various data base comparisons were not significant. For different sub-shells, either ECPSSR or RPWBA-BC compared better with the measurements. In all cases, agreement with theory improved as the collision energy increased.

Cipolla, Sam J. [Physics Department, Creighton University, Omaha, NE 68178 (United States)

2011-06-01

14

K and L shell x-ray fluorescence cross sections  

SciTech Connect

The K and L shell x-ray fluorescence (XRF) cross sections for elements with 13 {le} Z {le} 92 and 35 {le} Z {le} 92, respectively, are calculated for an incident photon energy range 1-200 keV. The XRF cross sections for K{alpha}, K{beta}, Ll, L{alpha}, L{beta}, and L{gamma} groups of x rays are tabulated. These calculations use the comprehensive sets of physical parameters currently considered most reliable, namely, theoretical partial photoionization cross sections and x-ray emission rates of Scofield, K shell fluorescence yields compiled by Hubbell, and L{sub i} subshell fluorescence yields, Coster-Kronig transition probabilities, and K to L{sub i} subshell vacancy-transfer probabilities based on the Dirac-Hartree-Slater model. 28 refs., 3 figs., 2 tabs.

Puri, S.; Chand, B.; Mehta, D. [Panjab Univ., Chandigarn (India)

1995-11-01

15

PIXEF: The Livermore PIXE spectrum analysis package  

SciTech Connect

PIXEF (for, PIXE-Fit) is a proton-induced x-ray emission (PIXE) data analysis program designed for analyzing medium to heavy element matrices while retaining the capability to treat lower atomic number targets. Using nonlinear least squares fitting techniques, algorithms have been developed or modified both for fitting the characteristic x-ray peaks and representing the associated bremsstrahung and {gamma}-ray background. Self-absorption and secondary fluorescence are explicitly determined for K shell and L subshell x rays. Data bases have been created or improved, where necessary, from reliable current literature values or by direct measurement for element mass attenuation coefficients, photoionization and proton ionization cross sections, Coster-Kronig transition probabilities, fluorescence yields, and relative line intensities. The utility of the program is demonstrated with PDM spectra obtained at Livermore.

Antolak, A.J. [Sandia National Labs., Livermore, CA (United States); Bench, G.S. [Lawrence Livermore National Lab., CA (United States)

1993-07-01

16

L-subshell x-ray production cross sections of Ba, La and Ce for proton energies from 0. 25 to 2. 00 MeV  

SciTech Connect

Protons from the University of Texas at Arlington's 2 MV Van de Graaff accelerator were used to produce characteristic L x-rays from thin targets of Ba, La and Ce. The incident proton energy was varied from 0.25 to 2.00 MeV. The x-rays were detected by a detector mounted at 90/sup 0/ to the incident beam direction. Measured x-ray production cross sections were converted to ionization cross sections by the use of subshell fluorescence yields and CosterKronig transition probabilities taken from Bambynek. Inflection points are found in the L/sub 1/-subshell ionization cross section for all three elements. Although the theoretical plane-wave Born approximation (PWBA) curves do have inflection points (whereas the binary encounter approximation (BEA) curves do not), the PWBA theory does not correctly predict the proton energies at which these occur for all three elements.

Rayburn, L.A.

1983-04-01

17

Correlated double electron capture in slow, highly charged ion-atom collisions  

Microsoft Academic Search

Recent measurements of autoionization electrons produced in slow, highly charged ion-atom collisions are reviewed. Mechanisms for double electron capture into equivalent and nonequivalent configurations are analyzed by comparing the probabilities for the creation of LâLââX Coster Kronig electrons and L-Auger electrons. It is shown that the production of the Coster-Kronig electrons is due to electron correlation effects whose analysis leads

N. Stolterfoht; C. C. Havener; R. A. Phaneuf; J. K. Swenson; S. M. Shafroth; F. W. Meyer

1986-01-01

18

Correlated double electron capture in slow, highly charged ion-atom collisions  

Microsoft Academic Search

Recent measurements [1,2] of autoionization electrons produced in slow, highly charged ion-atom collisions are reviewed. Mechanisms for double electron capture into equivalent and nonequivalent configurations are analyzed by comparing the probabilities for the creation of L-Auger electrons and L1L23X Coster-Kronig electrons. It is shown that the production of the Coster-Kronig electrons is due to electron correlation effects whose analysis leads

N. Stolterfoht; C. C. Havener; R. A. Phaneuf; J. K. Swenson; S. Shafroth; F. W. Meyer

1987-01-01

19

Calculation of Ion Charge State Distributions After Inner-Shell Ionization in Xe Atom  

NASA Astrophysics Data System (ADS)

The vacancy cascades following initial inner-shell vacancies in single and multi-ionized atoms often lead to highly charged residual ions. The inner-shell vacancy produced by ionization processes may decay by either a radiative or non-radiative transition. In addition to the vacancy filling processes, there is an electron shake off process due to the change of core potential of the atom. In the calculation of vacancy cascades, the radiative (x-ray) and non-radiative (Auger and Coster-Kronig) branching ratios give valuable information on the de-excitation dynamics of an atom with inner-shell vacancy. The production of multi-charged ions yield by the Auger cascades following inner shell ionization of an atom has been studied both experimentally and theoretically. Multi-charged Xe ions following de-excitation of K-, L1-, L2,3-, M1-, M2,3- and M4,5 subshell vacancies are calculated using Monte-Carlo algorithm to simulate the vacancy cascade development. Fluorescence yield (radiative) and Auger, Coster- Kronig yield (non- radiative) are evaluated. The decay of K hole state through radiative transitions is found to be more probable than non-radiative transitions in the first step of de-excitation. On the other hand, the decay of L, M vacancies through non-radiative transitions are more probable. The K shell ionization in Xe atom mainly yields Xe7+, Xe8+, Xe9+ and Xe10+ ions, and the charged X8+ ions are the highest. The main product from the L1- shell ionization is found to be Xe8+, Xe9+ ions, while the charged Xe8+ ions predominate at L2,3 hole states. The charged Xe6+, Xe7+ and Xe8+ ions mainly yield from 3s1/2 and 3p1/2,3/2 ionization, while Xe in 3d3/2,5/2 hole states mainly turns into Xe4+ and Xe5+ ions. The present results are found to agree well with the experimental data.

Mohammedein, Adel M.; Ghoneim, Adel A.; Kandil, Kandil M.; Kadad, Ibrahim M.

2010-01-01

20

L -subshell vacancy decay processes for elements with 52?Z?57 following ionization using Mn K? x rays  

NASA Astrophysics Data System (ADS)

The Li - (i=1-3) subshell x-ray spectra for the T52e , I53 , C55s , B56a , and L57a elements excited by Mn K? ( EK?2=5.888keV and EK?1=5.899keV ) x rays have been investigated using the F55e radioisotope in conjunction with a Cr absorber. A low-energy Ge detector was used to measure the L x rays at an emission angle ?=126° , where the second-order Legendre polynomial term P2 (cos?) associated with the angular distribution is annulled. In the case of the B56a and L57a elements, alignment of the L3 -subshell vacancy states was investigated through angular distribution measurements of the emitted L3 -subshell x rays. The L?1,2 and L?2,15 x-ray groups are observed to be nearly isotropic, while the data for the pure Ll (L3-M1) x-ray emission are indicative of a small anisotropic trend, though within experimental error. The integral x-ray fluorescence cross sections are deduced and interpreted in terms of Li -subshell photoionization cross sections, fluorescence and Coster-Kronig yields, and x-ray emission rates. The L2 -subshell x-ray cross sections for L57a measured using targets of lanthanum (III) fluoride and dilanthanum (III) trioxide are found to be unusually higher. The enhancement is observed due to the contribution of the L2 -subshell radiative resonant Raman scattering (RRS) of Mn K? x rays having energy around the L2 -subshell binding energy of L57a in these compounds. Also, the observed enhancement of the L3 -subshell x-ray cross sections in L57a is suggestive of intrashell vacancy transfer via L2-L3 Coster-Kronig RRS transitions. The L2 -subshell total RRS cross sections in L57a have been deduced from the present measured attenuation coefficients for Mn K? x rays in La2O3 and LaF3 . The L2 -subshell radiative and total RRS cross sections in L57a using LaF3 are higher by ˜30% than those using La2O3 . The contribution of processes predicted in the framework of Mozouchi’s four-band model involving inner subshells along with the valence and conduction bands of these wide-band-gap insulator compounds is likely to account for the observed results. The L2 -subshell radiative and L2-L3 Coster-Kronig yields and the ratio of the L2-M4 and L2-N4 radiative RRS intensities in both La compounds are found to be same and are consistent with values from photoexcited vacancy decay. The L2 -subshell radiative RRS was also observed to be isotropic.

Sharma, Veena; Kumar, Sanjeev; Mehta, D.; Singh, Nirmal

2008-07-01

21

Multiple ionization and coupling effects in L-subshell ionization of heavy atoms by oxygen ions  

SciTech Connect

The multiple-ionization and coupling effects in L-shell ionization of atoms by heavy-ion impact have been studied by measuring the L x-ray production cross sections in solid targets of Au, Bi, Th, and U bombarded by oxygen ions in the energy range 6.4-70 MeV. The measured L x-ray spectra were analyzed using the recently proposed method accounting for the multiple-ionization effects, such as x-ray line shifting and broadening, which enables one to obtain the ionization probabilities for outer shells. The L-subshell ionization cross sections have been obtained from measured x-ray production cross sections for resolved L{alpha}{sub 1,2}, L{gamma}{sub 1}, and L{gamma}{sub 2,3} transitions using the L-shell fluorescence and Coster-Kronig yields being substantially modified by the multiple ionization in the M and N shells. In particular, the effect of closing of strong L{sub 1}-L{sub 3}M{sub 4,5} Coster-Kronig transitions in multiple-ionized atoms was evidenced and discussed. The experimental ionization cross sections for the L{sub 1}, L{sub 2}, and L{sub 3} subshells have been compared with the predictions of the semiclassical approximation (SCA) and the ECPSSR theory that includes the corrections for the binding-polarization effect within the perturbed stationary states approximation, the projecticle energy loss, and Coulomb deflection effects as well as the relativistic description of inner-shell electrons. These approaches were further modified to include the L-subshell couplings within the ''coupled-subshell model'' (CSM). Both approaches, when modified for the coupling effects, are in better agreement with the data. Particularly, the predictions of the SCA-CSM calculations reproduce the experimental L-subshell ionization cross section reasonably well. Remaining discrepancies are discussed qualitatively, in terms of further modifications of the L-shell decay rates caused by a change of electronic wave functions in multiple-ionized atoms.

Pajek, M.; Banas, D.; Semaniak, J.; Braziewicz, J.; Majewska, U.; Chojnacki, S.; Czyzewski, T.; Fijal, I.; Jaskola, M.; Glombik, A.; Kretschmer, W.; Trautmann, D.; Lapicki, G.; Mukoyama, T. [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce, (Poland); The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk, (Poland); Physikalisches Instituet, Universitaet Erlangen-Nuernberg, D-91058 Erlangen, (Germany); Instituet fuer Physik, Universitaet Basel, CH-4056 Basel, (Switzerland); Department of Physics, East Carolina University, Greenville, North Carolina 27858, USA (United States); Kansai Gaidai University, Hirakata, Osaka 573-1001, (Japan)

2003-08-01

22

2s photoionization and subsequent Auger cascade in atomic Si  

SciTech Connect

The 2s photoionization and subsequent Auger transition cascade in atomic Si were studied by means of synchrotron-radiation-induced electron spectroscopy. After the 2s photoionization, the core hole states decay predominantly by a two-step Auger transition cascade into the triply ionized [Ne]nl states. The ionization channels of the 2s core-ionized Si{sup +} atoms to Si{sup 3+} ions were observed by measuring the conventional Auger electron spectra of the L{sub 1}-L{sub 2,3}M Coster-Kronig transitions and the L{sub 2,3}M-MMM Auger transitions. The observed L{sub 1}-L{sub 2,3}M and L{sub 2,3}M-MMM Auger spectra were analyzed by means of extensive multiconfiguration Dirac-Fock computations. We found that the electron correlation plays a prominent role in the Auger cascade, especially for the final-step Auger L{sub 2,3}M-MMM spectrum. Additionally, it was seen that the L{sub 2,3}M-MMM Auger spectrum of Si includes more Auger groups than the isoelectronic L{sub 2,3}-MM Auger spectrum of Al. Thus, more information on the intermediate ionic states is obtained if they are produced by Auger cascade rather than by direct photoionization.

Partanen, L.; Fritzsche, S.; Jaenkaelae, K.; Huttula, M.; Osmekhin, S.; Aksela, H.; Aksela, S. [Department of Physics, University of Oulu, P. O. Box 3000, 90014 University of Oulu (Finland); Urpelainen, S. [Department of Physics, University of Oulu, P. O. Box 3000, 90014 University of Oulu (Finland); MAX-lab, Lund University, P. O. Box 118, SE-22100 Lund (Sweden)

2010-06-15

23

Studies of electron correlation effects in multicharged ion atom collisions involving double capture  

SciTech Connect

We review measurements of L-Coster Kronig and Auger electron production in slow, multicharged collision systems to study electron correlation effects in the process of double electron capture. The n/sup /minus/3/ law was confirmed for the production of the Coster-Kronig configurations 1s/sup 2/2pn/ell/ (n greater than or equal to 6) in O/sup 6 +/ + He collisions. Enhancement of high angular momentum /ell/ in specific 1s/sup 2/2pn/ell/ configurations was observed by means of high-resolution measurements of the Coster-Kronig lines. The importance of electron correlation effects in couplings of potential energy curves leading to the 1s/sup 2/2pn/ell/ configurations is verified by means of Landau-Zener model calculations. 32 refs., 4 figs.

Stolterfoht, N.; Sommer, K.; Griffin, D.C.; Havener, C.C.; Huq, M.S.; Phaneuf, R.A.; Swenson, J.K.; Meyer, F.W.

1988-01-01

24

Photoionization measurements for the iron isonuclear sequence Fe3+, Fe5+, and Fe7+  

NASA Astrophysics Data System (ADS)

Cross sections for single photoionization of Fe3+, Fe5+, and Fe7+ ions were measured at spectral resolutions of 0.04, 0.15, and 0.13 eV, respectively, by merging mass- and charge-selected ion beams with a beam of monochromatized synchrotron undulator radiation. The measurements span photon energy ranges beginning at the ionization thresholds and extending several tens of electron volts to include the most important resonant contributions due to 3p-nd transitions to autoionizing states. The photoion yield spectra are characterized by narrow resonances and also broad features in Fe3+ and Fe5+ that are believed to result from unresolved fast super-Coster-Kronig transitions following 3p-3d excitation. Absolute photoionization cross-section measurements were also performed using ion beams containing undetermined fractions of ions in their ground and metastable states. A Rydberg series attributed to 3p-nd transitions from the 2G1 metastable state in Fe3+ was identified. The data are compared with recently published measurements on Fe3+ and Fe5+ using a similar technique at lower spectral resolution.

Gharaibeh, M. F.; Aguilar, A.; Covington, A. M.; Emmons, E. D.; Scully, S. W. J.; Phaneuf, R. A.; Müller, A.; Bozek, J. D.; Kilcoyne, A. L. D.; Schlachter, A. S.; Àlvarez, I.; Cisneros, C.; Hinojosa, G.

2011-04-01

25

Measurement of the XUV photoabsorption spectra of atomic zinc and its ions ?: n = 1, 2, and 3 in the region of 3p-subshell excitation  

NASA Astrophysics Data System (ADS)

Photoabsorption studies, using the dual laser plasma technique, have been initiated along the zinc isonuclear sequence as far as 0953-4075/30/21/017/img9 in the energy region corresponding to 3p-subshell electron excitation. For neutral, singly and doubly ionized zinc the 3d-subshell remains closed and excitations of the type 3p - ns have been found to predominate. The symmetric nature of the resonance profiles is evidence of the weak interaction of these discrete states with the underlying 0953-4075/30/21/017/img10 continua. The relatively large widths of the resonances can be interpreted as being mostly due to the nonradiative decay of the 3p core hole through both super and normal Coster - Kronig decay processes. The spectral signature of the `transition metal-like' 0953-4075/30/21/017/img9 3p - 3d resonance is dramatically different, the asymmetric nature of which reflects the increased interaction between direct 3d photoionization and the discrete excitation processes. The main resonances in the spectra of 0953-4075/30/21/017/img12, and 0953-4075/30/21/017/img9 have been parametrized and compared with calculations based on both single-particle and collective models.

Kiernan, L. M.; Costello, J. T.; Kennedy, E. T.; Mosnier, J.-P.; Sonntag, B. F.

1997-11-01

26

L{alpha}, L{beta}, and L{gamma} x-ray production cross sections of Hf, Ta, W, Re, Os, Au, Pb, and Bi by electron impact: Comparison of distorted-wave calculations with experiment  

SciTech Connect

We study the emission of L{alpha}, L{beta}, and L{gamma} characteristic x rays by the impact of electrons on Hf, Ta, W, Re, Os, Au, Pb, and Bi atoms. To this end, ionization cross sections of the L{sub 1}, L{sub 2}, and L{sub 3} subshells of these atoms are calculated within the distorted-wave Born approximation. The considered energy interval spans from the ionization threshold up to 50 keV. Atomic relaxation parameters (i.e., Coster-Kronig and radiative transition probabilities, fluorescence yields, and emission rates) taken from the literature are then used to evaluate x-ray production cross sections. The theoretical predictions are compared with published experimental information. Good agreement is found for Ta, W, Os, Au, Pb, and Bi. In the case of Hf and Re, the measured cross sections are lower than the theoretical estimates by around 30%. The observed discrepancies might be attributed to the methods employed to correct the raw experimental data for the excess of detected characteristic x rays caused by the finite thickness of the sample's active layer and the presence of the thick substrate.

Fernandez-Varea, Jose M.; Segui, Silvina; Dingfelder, Michael [Facultat de Fisica (ECM and ICC), Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche, Rio Negro (Argentina); Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States)

2011-02-15

27

Chemical effects on the Li(i=1-3) sub-shell X-ray relative intensities for some compounds of Hg  

NASA Astrophysics Data System (ADS)

The intensity ratios, ILk/IL?(exp) (k=l, ?, ?4,6, ?1,2,3,15, ?5,7, ?1,5, ?2,3,6,8, ?4, ?, ?), have been measured for some compounds of 80Hg, namely, HgI2, Hg(C2H3O2)2 and a pure 80Hg target (liquid form) at 22.6 keV incident photon energy in order to investigate the influence of chemical effects on these ratios for a heavy transition element. The measurements have been performed using the EDXRF spectrometer involving a disk type radioactive source of Cd109 and a Peltier cooled Si-PIN X-ray detector arranged in the 90° reflection geometry. The measured intensity ratios have been compared with the theoretical ILk/IL? (Thr.) values (Kumar et al., 2010) and those calculated using the fluorescence and Coster-Kronig yields tabulated by Campbell (2003, 2009) and Krause (1979) in order to check the reliability of these available values. The measured ratios, IL?5,7/IL? (Exp.), were found to be influenced by the chemical effects.

Kumar, Anil; Puri, Sanjiv

2011-11-01

28

Systematic photoionization study along the iron isonuclear sequence  

NASA Astrophysics Data System (ADS)

The first measurements of photoionization of Fe3+, Fe 5+, and Fe7+ ions were made using the ion-photon beam endstation on beamline 10.0.1 at the Advanced Light Source, where ion beams from an ECR source were merged with monochromatic beams of synchrotron radiation. The photoion-yield spectra contain numerous resonances due to photoexcitation of autoionizing states, including extremely broad features in Fe3+ and Fe5+ that are thought to result from fast super-Coster-Kronig transitions following 3p-3d excitations. Absolute photoionization cross-section measurements were also performed for these ions using beams with unknown fractions of ground and metastable states. A Rydberg series from the 2G1 metastable state in Fe3+ was identified and assigned. The absolute cross-section measurements were compared with different theoretical calculations. Large differences were found between the absolute cross-section measurements in this study and the TOPbase atomic database widely used in astrophysics. A new R-matrix calculation shows better correspondence to the Fe3+ experimental data, but substantial differences remain. The presence of unknown fractions of primary ions in metastable and ground states significantly complicates the analysis of the data and comparison with theory. Hartree-Fock calculations of autoionizing states of Fe7+ were performed, but found to be inadequate to accurately predict the energies of the resonances observed in photoionization.

Gharaibeh, Mohammad F.

29

Computation of Ion Charge State Distributions After Inner-Shell Ionization In Ne, Ar And Kr Atoms Using Monte Carlo Simulation  

SciTech Connect

Atomic reorganization starts by filling the initially inner-shell vacancy by a radiative transition (x-ray) or by a non-radiative transition (Auger and Coster-Kronig processes). New vacancies created during this atomic reorganization may in turn be filled by further radiative and non-radiative transitions until all vacancies reach the outermost occupied shells. The production of inner-shell vacancy in an atom and the de-excitation decays through radiative and non-radiative transitions may result in a change of the atomic potential; this change leads to the emission of an additional electron in the continuum (electron shake-off processes). In the present work, the ion charge state distributions (CSD) and mean atomic charge ions produced from inner-shell vacancy de-excitation decay are calculated for neutral Ne, Ar and Kr atoms. The calculations are carried out using Monte Carlo (MC) technique to simulate the cascade development after primary vacancy production. The radiative and non-radiative transitions for each vacancy are calculated in the simulation. In addition, the change of transition energies and transition rates due to multi vacancies produced in the atomic configurations through the cascade development are considered in the present work. It is found that considering the electron shake--off process and closing of non-allowed non-radiative channels improves the results of both charge state distributions (CSD) and average charge state. To check the validity of the present calculations, the results obtained are compared with available theoretical and experimental data. The present results are found to agree well with the available theoretical and experimental values.

Mohammedein, Adel M.; Ghoneim, Adel A.; Al-Zanki, Jasem M.; El-Essawy, Ashraf H. [Applied Sciences Department, College of Technological Studies, P.O. Box 42325, Shuwaikh 70654 (Kuwait)

2010-01-05

30

Computation of Ion Charge State Distributions After Inner-Shell Ionization In Ne, Ar And Kr Atoms Using Monte Carlo Simulation  

NASA Astrophysics Data System (ADS)

Atomic reorganization starts by filling the initially inner-shell vacancy by a radiative transition (x-ray) or by a non-radiative transition (Auger and Coster-Kronig processes). New vacancies created during this atomic reorganization may in turn be filled by further radiative and non-radiative transitions until all vacancies reach the outermost occupied shells. The production of inner-shell vacancy in an atom and the de-excitation decays through radiative and non-radiative transitions may result in a change of the atomic potential; this change leads to the emission of an additional electron in the continuum (electron shake-off processes). In the present work, the ion charge state distributions (CSD) and mean atomic charge ions produced from inner-shell vacancy de-excitation decay are calculated for neutral Ne, Ar and Kr atoms. The calculations are carried out using Monte Carlo (MC) technique to simulate the cascade development after primary vacancy production. The radiative and non-radiative transitions for each vacancy are calculated in the simulation. In addition, the change of transition energies and transition rates due to multi vacancies produced in the atomic configurations through the cascade development are considered in the present work. It is found that considering the electron shake-off process and closing of non-allowed non-radiative channels improves the results of both charge state distributions (CSD) and average charge state. To check the validity of the present calculations, the results obtained are compared with available theoretical and experimental data. The present results are found to agree well with the available theoretical and experimental values.

Mohammedein, Adel M.; Ghoneim, Adel A.; Al-Zanki, Jasem M.; El-Essawy, Ashraf H.

2010-01-01

31

Disabilities & Transitions.  

ERIC Educational Resources Information Center

This newsletter discusses transition and outcome issues for young children with disabilities. Topics discussed include issues related to transition program administration, staff, families, and services. (KB)

Wolery, Mark

1998-01-01

32

Transit Tracks  

NSDL National Science Digital Library

In this space science activity, learners explore transits and the conditions when a transit may be seen. Learners use models to investigate how a planet's size and distance from its star affects the behavior of transits. Learners also use mathematics to interpret graphs of brightness vs. time to deduce information about planet-star systems. This lesson includes educator instructions, photocopy masters for Transit Light Curves, Option Math for Transit Tracks, Keplerâs 3rd Law graphs, cube root tables, an account of Jeremiah Horrocks' 1639 observation of the transit of Venus, and an answer key for the Transit Tracks Light Curves.

Science, Lawrence H.

2008-01-01

33

Work transitions.  

PubMed

Individuals make choices in, and adjust to, a world of work that is often a moving target. Because work is so central to human functioning, and transitions in and out of work can have major mental health repercussions, the authors argue that applied psychologists in health services need to understand those transitions. This article focuses on the different types of transition throughout a person's working life and the resources needed at different stages to ensure the success of these transitions. The authors start by examining the roles of capability and adaptability in supporting and facilitating adjustment to work transitions and their relation to identity development. They then examine the role of social and institutional contexts in shaping work transitions and their outcomes. The authors focus on voluntary versus involuntary transitions and then broaden the lens in discussing the policy implications of research on work transitions. PMID:18473609

Fouad, Nadya A; Bynner, John

34

Transition metals  

PubMed Central

Transition metals such as Iron (Fe) and Copper (Cu) are essential for plant cell development. At the same time, due their capability to generate hydroxyl radicals they can be potentially toxic to plant metabolism. Recent works on hydroxyl-radical activation of ion transporters suggest that hydroxyl radicals generated by transition metals could play an important role in plant growth and adaptation to imbalanced environments. In this mini-review, the relation between transition metals uptake and utilization and oxidative stress-activated ion transport in plant cells is analyzed, and a new model depicting both apoplastic and cytosolic mode of ROS signaling to plasma membrane transporters is suggested.

Rodrigo-Moreno, Ana; Poschenrieder, Charlotte; Shabala, Sergey

2013-01-01

35

Metric transition  

NASA Astrophysics Data System (ADS)

This report describes NASA's metric transition in terms of seven major program elements. Six are technical areas involving research, technology development, and operations; they are managed by specific Program Offices at NASA Headquarters. The final program element, Institutional Management, covers both NASA-wide functional management under control of NASA Headquarters and metric capability development at the individual NASA Field Installations. This area addresses issues common to all NASA program elements, including: Federal, state, and local coordination; standards; private industry initiatives; public-awareness initiatives; and employee training. The concluding section identifies current barriers and impediments to metric transition; NASA has no specific recommendations for consideration by the Congress.

1992-06-01

36

Transitional Economies  

Microsoft Academic Search

Theories of economic transition were revolutionized by the dramatic events of 1989, when several East European states openly\\u000a broke with the Soviet Union and expressed desires for more democratic rights and free markets. As Soviet domination of Eastern\\u000a Europe dissolved, there was not only understandable jubilation in Europe, but also expressions of shock throughout capitals\\u000a of the world. Radio Free

Michael J. G. Cain

37

Dynamo Transition  

NASA Astrophysics Data System (ADS)

In this article we review the experimental and numerical results related to the dynamo transitions. Recent experiments of Von Kármán Sodium (VKS) exhibit various dynamo states including constant, time-periodic, and chaotic magnetic fields. Similarly pseudospectral simulations of dynamo show constant, time-periodic, quasiperiodic, and chaotic magnetic field configurations. One of the windows for the magnetic Prandtl number of unity shows period doubling route to chaos. Quasiperiodic route to chaos has been reported for the Prandtl number of 0.5. The dynamo simulations also reveal coexisting multiple attractors that were obtained for different initial conditions.

Verma, M. K.; Yadav, R.; Chandra, M.; Paul, S.; Wahi, P.

2010-11-01

38

TRANSITIVE PROPERTIES OF IDEALS  

Microsoft Academic Search

In this paper we present a wide range of results connected with transitive properties of ideals. In particular, we present relations between standard and transitive coecients of ideals and compute transitive cardinal coecients of ideals on generalized Cantor spaces.

JAN KRASZEWSKI

39

Transitions: A Personal Perspective.  

ERIC Educational Resources Information Center

Distinguishes between unchosen transitions (children maturing and leaving, parents aging, companies downsizing) and chosen ones (moving, divorce, marriage, career changes). Describes the steps one goes through: uneasiness, renewed energy, complaining, exploration, partial transition, and the completed transition. (JOW)

Wood, Ann Stace

1995-01-01

40

MassTransitMag  

NSDL National Science Digital Library

The MassTransit website is dedicated to "Better Transit Through Better Management", and their offerings include industry news, email newsletters, video profiles, and opinion pieces about the world of mass transit. The site is mostly dedicated to providing information about mass transit systems in the United States, though visitors will note that there is some coverage of international transit systems as well. The "Current Issue" section includes full-text version of most of the articles found in the print issue, along with an archive dating back to 2005. For more up-to-the minute coverage of transit affairs, the "Daily News" area digests ongoing legislation, transit improvements, and long-range plan updates from a variety of sources. The "MassTransit Interactive" area allows users to read and comment on editor's comments on the news affecting the transit world, including issues such as federal funding mechanisms, light-rail initiatives, and union contracts.

41

Central Ohio Transit Authority Transit Development Program.  

National Technical Information Service (NTIS)

The purpose of the study is to select the best set of options available to the Central Ohio Transit Authority (COTA) in its effort to improve, acquire, and expand the present transit system in the Central Ohio area. The report begins with a background of ...

1973-01-01

42

Gas turbine combustor transition  

DOEpatents

A method of converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit.

Coslow, Billy Joe (Winter Park, FL); Whidden, Graydon Lane (Great Blue, CT)

1999-01-01

43

Study of Phase Transitions.  

National Technical Information Service (NTIS)

The diamagnetic transition in CuCl has been verified, and materials studies have been carried out to determine the conditions under which this transition, which may per precursive to high temperature superconductivity, may be found. A photoactivated, defe...

I. Lefkowitz

1983-01-01

44

Glass transition(s) of ionomers  

SciTech Connect

Ionomers are predominantly nonpolar polymers that contain a small amount of bonded salt groups. Microphase separation of ion-rich microdomains occurs as a consequence of the thermodynamic incompatibility of the salt groups and the polymer matrix and associative interactions between salt groups. Associations of the salt groups usually increase the glass transition of the continuous matrix phase, presumably as a consequence of the inhibition of chain mobility that accompanies physical crosslinking. The central question raised in this paper is whether the dispersed ion-rich microphase exhibits a glass transition. Although no glass transition for the microphase is detected by calorimetry, a dynamic mechanical relaxation is commonly observed above the T{sub g} of the matrix phase. This transition has some of the attributes of a glass transition, but it is not clear what is the actual relaxation process that is measured. This paper discusses the effect of the ionic groups on the matrix glass transition, the origin of the high-temperature dynamic mechanical transition, and the effects of the addition of plasticizers on the T{sub g} of the matrix and the higher temperature mechanical relaxation.

Weiss, R.A. [Univ. of Connecticut, Storrs, CT (United States). Inst. of Materials Science

1994-09-01

45

Transitive and pseudo-transitive inferences.  

PubMed

Given that A is longer than B, and that B is longer than C, even 5-year-old children can infer that A is longer than C. Theories of reasoning based on formal rules of inference invoke simple axioms ("meaning postulates") to capture such transitive inferences. An alternative theory proposes instead that reasoners construct mental models of the situation described by the premises in order to draw such inferences. An unexpected consequence of the model theory is that if adult reasoners construct simple models of typical situations, then they should infer transitive relations where, in certain cases, none exists. We report four studies corroborating the occurrence of these "pseudo-transitive" fallacies. Experiment 1 established that individuals' diagrams of certain non-transitive relations yield transitive conclusions. Experiment 2 showed that these premises also give rise to fallacious transitive inferences. Experiment 3 established that when the context suggested alternatives to the simple models, the participants made fewer errors. Experiment 4 showed that tense is an important aspect of meaning which affects whether individuals draw transitive conclusions. We discuss the implications of these results for various theories of reasoning. PMID:18395196

Goodwin, Geoffrey P; Johnson-Laird, P N

2008-04-18

46

Augmented transit maps  

Microsoft Academic Search

We introduce a new class of mobile augmented reality navigation applications that allow people to interact with transit maps in public transit stations and vehicles. Our system consists of a database of coded transit maps, a vision engine for recognizing and tracking planar objects, and a graphics engine to overlay relevant real-time navigation information, such as the user’s current location

Matei Stroila; Joe Mays; Bill Gale; Jeff Bach

2011-01-01

47

Transitivity of Preferences  

ERIC Educational Resources Information Center

|Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to "z". Any claim of empirical violations of transitivity by…

Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

2011-01-01

48

Government in transition  

Microsoft Academic Search

The speed of economic reforms is not the only important determinant of the success of the transition to a market economy: the transition of government from a communist state to an institution supporting a market economy is as critical. Survey evidence shows that Russia lags significantly behind Poland in the transition of its government, which may account for its inferior

Andrei Shleifer

1997-01-01

49

Transit pricing and performance  

SciTech Connect

The 9 papers in the report deal with the following areas: Federal operating assistance for urban mass transit; a decade of experience; transit route characteristics and headway-based reliability control; day-of-week and part-of-month variation in bus ridership; job satisfaction and transit operator recognition programs; results of a survey of muni operators; bus marketing costs: the experience of 18 section 15 reporters from 1981 to 1983; prospects for differential transit pricing in the United States; an initial analysis of total factor productivity for public-transit coordination of transportation resources: the Georgia experience; absenteeism, accidents, and attrition: part-time versus full-time bus drivers.

Pickerell, D.H.; Abkowitz, M.; Tozzi, J.; McCord, M.R.; Cheng, L.H.

1986-01-01

50

Transit Marketing: Successes and Failures.  

National Technical Information Service (NTIS)

The synthesis will be of interest to transit planners, administrators, and others in the transit field who are concerned with the marketing of transit services. Information is presented on transit marketing programs that have been successful and on some t...

R. L. Oram

1987-01-01

51

Reconstructing Regulatory Network Transitions  

PubMed Central

Cellular responses often involve a transition of cells from one state to another. A transition from a stem cell to differentiated cell state, for example, may occur in response to gene expression changes induced by a transcription factor, or signaling cascades triggered by a hormone or pathogen. Regulatory networks are thought to control such cellular transitions. Thus, many researchers are interested in reconstructing regulatory networks, not only to gain a deeper understanding of cellular transitions, but also with the aim of using networks to predict and potentially manipulate cellular transitions and outcomes. In this review, we highlight approaches to the reconstruction of regulatory networks underlying cellular transitions, with special attention to transcriptional regulatory networks. We describe recent regulatory network reconstructions in a variety of organisms and discuss the success they share in identifying new regulatory components as well as shared relationships and phenotypic outcomes.

Petricka, Jalean J.; Benfey, Philip N.

2011-01-01

52

Metal-insulator transitions  

Microsoft Academic Search

Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject. Especially important are the transitions driven by correlation effects associated with the electron-electron interaction. The insulating phase caused by

Masatoshi Imada; Atsushi Fujimori; Yoshinori Tokura

1998-01-01

53

Moons over Jupiter: transits and shadow transits  

NASA Astrophysics Data System (ADS)

There is no more beautiful illustration of orbital motions than the movements of Jupiter's satellites. Every six years, their movements are most strikingly displayed, when the jovian system is presented edge-on to Earth. This means that there is a higher frequency of multiple transits over the face of the planet, as all the moons transit across the equatorial zone, whereas in other years Ganymede and Callisto transit near the poles or not at all. Also, for a few months, the satellites pass in front of each other, displaying mutual eclipses and occultations. In 2002/2003 we have been able to observe a fine series of these multiple and mutual events. On the cover, and on these pages, are some of the highest-resolution images received.

Rogers, J. H.; et al.

2003-06-01

54

Dynamical Transition in polypeptides  

NASA Astrophysics Data System (ADS)

Two of the possible causes for the so called dynamical transition (the rapid increase in flexibility for biomolecules at ˜ 200 K) are: thermally activated side chain diffusive motions with hydration dependent activation energies; or a glass transition in the biological water directly adjacent to the biomolecule. If the transition is strictly due to side chain activation, it should not depend on protein structure. Previously we demonstrated that the dynamical transition remains after tertiary structure was removed using THz time domain dielectric spectroscopy (0.2 -2.0 THz, 0.5-5ps). Here measurements on polyalanine as a function of chain length show that the dynamical transition does not occur for peptide length shorter than 5. However, the transition is observed for 5 mer and higher. Structural and simulation studies indicate that the 5 mer transiently occupies structured forms [1,2]. These results suggest that A) the dynamical transition is not due to thermally activated side chain motion and B) secondary structure is necessary for the dynamical transition. Secondary structure possibly induces sufficient ordering in the adjacent water to result in a fragile to strong glass transition resulting in increased protein flexibility [3]. [1] KAH Wildman et al. Solid State Nucl. Magn. Reson. 24 (2003) 94-109. [2] Yuguang Mu,et al. Proteins 58, (2005) 45-52. [3] S.H. Chen et al. PNAS (2006) 9012--9016.

He, Yunfen; Markelz, Andrea

2008-03-01

55

Transition to adult services.  

PubMed

The lack of focus on young people as a group with particular healthcare needs in medical training and the health service underpins the difficulty that we have experienced as a profession in improving transition in the UK. This article discusses current progress towards improving training in young people's health in the UK, the evidence base for transitional care in young people with chronic conditions with interventions that focus on staffing, service delivery and young people, a practice based approach for transitional care in young people with learning difficulties and complex needs, the need for monitoring and evaluation of transitional care, and the challenge of funding. PMID:21979963

Gleeson, Helena; Turner, Gill

2011-10-06

56

Use of Electron Correlation to Make Attosecond Measurements without Attosecond Pulses  

SciTech Connect

We describe how correlations between electrons can be used to trace the dynamics of correlated two-electron ionization with attosecond precision, without using attosecond pulses. The approach is illustrated using the example of Auger or Coster-Kronig decay triggered by photoionization with an extreme ultraviolet pulse. It requires correlated measurements of angle-resolved energy spectra of both the photo- and Auger electrons in the presence of a laser pulse. To reconstruct the dynamics, we use not only classical time and energy correlation, but also entanglement between the two electrons.

Smirnova, Olga [Photonics Institute, Vienna University of Technology, Gusshausstrasse 27/387, A-1040 Vienna (Austria); Yakovlev, Vladislav S. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, am Coulombwall 1, D-85748 Garching (Germany); Ivanov, Misha [NRC Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)

2005-06-03

57

Disparity in formulations used for fluorescent X-ray intensity measurements.  

PubMed

The paper presents a problem in computations of X-ray fluorescence cross-sections, shell/sub-shell fluorescence yields, Coster-Kronig yields, vacancy alignment, etc. from X-ray fluorescence (XRF) studies. While using barn/atom as a unit for cross-sections if the atomic masses are not considered it causes a discrepancy in the measured cross-section, yield and alignment values. Most of the earlier publications are being quoted where such an oversight has occurred and discrepancy is evident. PMID:21676620

Mittal, Raj; Gupta, Sheenu

2011-06-02

58

Transitive and pseudo-transitive inferences  

Microsoft Academic Search

Given that A is longer than B, and that B is longer than C, even 5-year-old children can infer that A is longer than C. Theories of reasoning based on formal rules of inference invoke simple axioms (“meaning postulates”) to capture such transitive inferences. An alternative theory proposes instead that reasoners construct mental models of the situation described by the

Geoffrey P. Goodwin; P. N. Johnson-Laird

2008-01-01

59

Transitions and Linkages.  

ERIC Educational Resources Information Center

|If children are to benefit from a healthy, supportive early childhood experience, it is important to strengthen transitions between early childhood experiences in educational and care settings and the more formal educational system. This issue of Coordinator's Notebook focuses on strengthening linkages and transitions between home, preschool, and…

Ilfeld, Ellen M., Ed.; Hanssen, Elizabeth, Ed.

1997-01-01

60

Transitioning between Clerkship Directors  

ERIC Educational Resources Information Center

|Objective: The authors report on succession-planning for mid-level academic positions. Method: The authors describe the process of succession-planning between clerkship directors and the smooth transition resulting in one case. Results: Gradually transitioning allowed a new faculty person to assume the clerkship-director position with minimal…

Soltys, Stephen M.; Pary, Robert J.; Robinson, Stephen W.; Markwell, Stephen J.

2011-01-01

61

Transitivity of preferences.  

PubMed

Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option x to y and y to z must prefer x to z. Any claim of empirical violations of transitivity by individual decision makers requires evidence beyond a reasonable doubt. We discuss why unambiguous evidence is currently lacking and how to clarify the issue. In counterpoint to Tversky's (1969) seminal "Intransitivity of Preferences," we reconsider his data as well as those from more than 20 other studies of intransitive human or animal decision makers. We challenge the standard operationalizations of transitive preferences and discuss pervasive methodological problems in the collection, modeling, and analysis of relevant empirical data. For example, violations of weak stochastic transitivity do not imply violations of transitivity of preference. Building on past multidisciplinary work, we use parsimonious mixture models, where the space of permissible preference states is the family of (transitive) strict linear orders. We show that the data from many of the available studies designed to elicit intransitive choice are consistent with transitive preferences. PMID:21244185

Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P

2011-01-01

62

Glass Transitions in Polylactides  

Microsoft Academic Search

The review focuses on the relationship between the structure and the glass transition temperature in polylactide and its derivatives. Simple design rules for controlling the glass transition temperature are developed and illustrated using examples from homopolymers, copolymers, and polymers derived from AB glycolide monomers. These materials have important applications as structural materials and in biomedical applications for drug delivery, surgical

Gregory L. Baker; Erin B. Vogel; Milton R. Smith III

2008-01-01

63

Law enforcement and transition  

Microsoft Academic Search

We present a simple model to analyze law enforcement problems in transition economies. Law enforcement implies coordination problems and multiplicity of equilibria due to a law abidance and a fiscal externality. We analyze two institutional mechanisms for solving the coordination problem. A first mechanism, which we call “dualism”, follows the scenario of Chinese transition where the government keeps direct control

Gérard Roland; Thierry Verdier

2003-01-01

64

Transit pricing research  

Microsoft Academic Search

Several decades of research on transit pricing have provided clear insights into how riders respond to price changes in both the transit and automobile sectors. For the most part, riders are insensitive to changes in either fare levels, structures, or forms of payments, though this varies considerably among user groups and operating environments. Since riders are approximately twice as sensitive

Robert Cervero

1990-01-01

65

Good Transitions = Great Starts!  

ERIC Educational Resources Information Center

|The smooth transition of outgoing and incoming board members and officers is of vital importance and can determine the PTA's success for years to come. The transition process is the responsibility of both incoming and outgoing officers and board members. It gives closure to those leaving their positions and allows those coming in to be properly…

Our Children: The National PTA Magazine, 2012

2012-01-01

66

Trauma, Transitions, and Thriving  

Microsoft Academic Search

Transitional experiences, what happens between states when someone changes developmentally, are special windows of opportunity for growth. They can be viewed in the microcosm of one's moments or in the macrocosm of an individual's life. We explore varieties of transitions, such as incremental or abrupt (intentional\\/ revelatory), transcendent or immanent, the ecstatic \\

David Hartman; Diane Zimberoff

2005-01-01

67

Atomic Dipole Transitions Applet  

NSDL National Science Digital Library

This simulation explores the transitions between quantum states in a hydrogen atom. The time-dependent wavefunction is displayed. An electric field resonant with the transition between states is applied and the changes in the wavefunction with time are tracked in a dipole approximation. Initial and final states can be selected by the user.

Falstad, Paul

2004-05-17

68

Seamless Transition for All  

ERIC Educational Resources Information Center

|Postschool outcomes for students with disabilities have been dismal for quite some time now. Although recent data from the National Longitudinal Transition Study 2 indicate some improvement, students with severe intellectual disabilities continue to transition into segregated employment at unacceptable rates in spite of a multitude of studies,…

Test, David W.

2008-01-01

69

Transition and agricultural labor  

Microsoft Academic Search

Reforms have strongly affected agricultural employment in transition countries but in remarkably different ways. We present a theoretical model and an empirical analysis to explain differences in labor adjustment during transition. We show that the differences are due to a combination of variations in initial conditions and differences in reform policies and effects. The removal of price distortions and subsidies

Johan F. M. Swinnen; Liesbeth Dries; Karen Macours

2005-01-01

70

Transforming Cities With Transit  

NSDL National Science Digital Library

How are cities transformed by the creation of new transit lines? How can existing transit lines be modified to create new land use opportunities for housing and commercial properties? These subjects are covered by a 172-page conference edition of a forthcoming paper from the World Bank. The paper was authored by Hiroaki Suzuki, Robert Cervero, and Kanako Iuchi. Visitors will note that the work focuses on "identifying barriers to and opportunities for effective coordination of transport infrastructure and urban development." The work takes on a number of global best practices of transit-oriented metropolises that have direct relevance to cities in developing countries and offers both analysis and suggestions for future projects. Sections here include "Lessons from Sustainable Transit-Oriented Cities," "Integrating Transit and Urban Development in Cities in the Developing World," and "Toward Sustainable Urban Futures."

Cervero, Robert.; Suzuki, Hiroaki; Iuchi, Kanako

71

Transition Implementation Guide. Instructor Materials.  

ERIC Educational Resources Information Center

|This transition model, called Guiding Education toward Adult Roles for Success (GEARS), provides a comprehensive framework from which transition services and programs can evolve. Three components of transition services are considered: transition partners, the transition process, and adult outcomes. After an introduction, the report's second…

Boyer-Stephens, Arden, Ed.

72

A Posteriori Transit Probabilities  

NASA Astrophysics Data System (ADS)

Given the radial velocity (RV) detection of an unseen companion, it is often of interest to estimate the probability that the companion also transits the primary star. Typically, one assumes a uniform distribution for the cosine of the inclination angle i of the companion's orbit. This yields the familiar estimate for the prior transit probability of ˜R*, given the primary radius R* and orbital semimajor axis a, and assuming small companions and a circular orbit. However, the posterior transit probability depends not only on the prior probability distribution of i but also on the prior probability distribution of the companion mass Mc, given a measurement of the product of the two (the minimum mass Mcsin i) from an RV signal. In general, the posterior can be larger or smaller than the prior transit probability. We derive analytic expressions for the posterior transit probability assuming a power-law form for the distribution of true masses, d?/dMc?Mc?, for integer values -3?? ? 3. We show that for low transit probabilities, these probabilities reduce to a constant multiplicative factor f? of the corresponding prior transit probability, where f? in general depends on ? and an assumed upper limit on the true mass. The prior and posterior probabilities are equal for ?. The posterior transit probability is ˜1.5 times larger than the prior for ? = -3 and is ˜4/? times larger for ? = -2, but is less than the prior for ??0, and can be arbitrarily small for ? > 1. We also calculate the posterior transit probability in different mass regimes for two physically-motivated mass distributions of companions around Sun-like stars. We find that for Jupiter-mass planets, the posterior transit probability is roughly equal to the prior probability, whereas the posterior is likely higher for Super-Earths and Neptunes (10 M?-30 M?) and Super-Jupiters (MJup-10 MJup), owing to the predicted steep rise in the mass function toward smaller masses in these regimes. We therefore suggest that companions with minimum masses in these regimes might be better-than-expected targets for transit follow-up, and we identify promising targets from RV-detected planets in the literature. Finally, we consider the uncertainty in the transit probability arising from uncertainties in the input parameters, and the effect of ignoring the dependence of the transit probability on the true semimajor axis on i.

Stevens, Daniel J.; Gaudi, B. Scott

2013-08-01

73

Child Custody in Transition.  

ERIC Educational Resources Information Center

Describes the transitional nature of child custody decisions in current legal decisions, and the shifting emhasis from parental to child's rights. The legal structure of joint custody is based on the child's right and need for conjoint parental accessibility. (Author)

Franklin, Robin L.; Hibbs, B.

1980-01-01

74

Transitions in biofilm formation  

NASA Astrophysics Data System (ADS)

Biofilms are multicellular, dynamic communities formed by interacting unicellular organisms bound to a surface. Forming a biofilm is a developmental process, characterized by sequential changes in gene expression and behavior as bacteria and yeast progress from discrete, free-swimming cells though stages that arrive at a mature biofilm. We are developing automated metrics to identify key transitions in early biofilm formation as cells attach to a surface, populate that surface, and adhere to each other to form early microcolonies. Our metrics use high-throughput tracking and analysis of microscopy movies to localize these transitions in space and time. Each of these transitions is associated with a loss of entropy in the bacterial system and, therefore, with biological activity that drives this loss of entropy. Better understanding of these transitions will allow automated determination of the strength and turn-on of attractive cell-surface and cell-cell interactions as biofilm development progresses.

Gordon, Vernita; Thatcher, Travis; Cooley, Benjamin

2011-03-01

75

Alternative fuel transit buses  

SciTech Connect

The National Renewable Energy Laboratory (NREL) is a U.S. Department of Energy (DOE) national laboratory; this project was funded by DOE. One of NREL`s missions is to objectively evaluate the performance, emissions, and operating costs of alternative fuel vehicles so fleet managers can make informed decisions when purchasing them. Alternative fuels have made greater inroads into the transit bus market than into any other. Each year, the American Public Transit Association (APTA) surveys its members on their inventory and buying plans. The latest APTA data show that about 4% of the 50,000 transit buses in its survey run on an alternative fuel. Furthermore, 1 in 5 of the new transit buses that members have on order are alternative fuel buses. This program was designed to comprehensively and objectively evaluate the alternative fuels in use in the industry.

Motta, R.; Norton, P.; Kelly, K. [and others

1996-10-01

76

Oligocyclopentadienyl transition metal complexes  

SciTech Connect

Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

de Azevedo, Cristina G.; Vollhardt, K. Peter C.

2002-01-18

77

Palaeontology: turtles in transition.  

PubMed

One of the major remaining gaps in the vertebrate fossil record concerns the origin of turtles. The enigmatic little reptile Eunotosaurus could represent an important transitional form, as it has a rudimentary shell that resembles the turtle carapace. PMID:23787042

Lee, Michael S Y

2013-06-17

78

Transit Bus Maintenance,  

National Technical Information Service (NTIS)

The 4 papers in the report deal with the following areas; vehicle maintenance: cost relationship and estimating methodology; theory and practice of transit bus maintenance performance measurement; bus maintenance performance indicators; historical develop...

J. E. Purdy J. D. Wiegmann T. H. Maze A. R. Cook G. List

1987-01-01

79

Transit of Venus  

NSDL National Science Digital Library

The Transit of Venus is similar to a solar eclipse, where -- from the perspective on Earth -- Venus passes in front of the Sun. This event does not happen very often. In fact, no one alive today has experienced this phenomenon, which will take place on June 8 and will be visible for most of Europe, Asia, and Africa.First, the Armagh Planetarium created a great, expansive informational site all about the Transit of Venus (1). Users can find basic facts, observing information, histories of past transits, and much more. Next, the European Southern Observatory presents the VT-2004 project's aim to gain knowledge and encourage public interest in the event (2). Users can observe Venus's progression towards the transit with the daily images from April 17, 2004 to present news updates. Educators can discover transit-related activities and educational materials. The third site, created by NASA, discusses the details of the Sun-Earth Connection Education Forum and San Francisco's Exploratorium's live webcast of the Transit (3). The site supplies enjoyable, educational materials for students, educators, museums, scientists, and amateur astronomers. The next site, also created by NASA, provides an introduction to the Venus Transits that will take place June 2004 and 2012 (4). Visitors can find helpful figures and text about the geographic visibility of the events. The site offers an observer's handbook as well as a discussion about the predictions of the event. Next, Professor Backhaus presents a project where schools, amateur astronomers, and universities will collaborate to gather transit data and learn about observing (5). Users can discover the six parts of the project as well as learn how to participate in the worldwide endeavor. The sixth site also discusses a Venus Transit project (6). Endorsed by the Astronomical Association of Zurich, this project's goals are to process data collected by amateur astronomers by different observation methods, to act as a data exchange center, and to determine the astronomical unit. Next, the Exploratorium furnishes general information about the Transit, its history, how viewers observe it, what it looks like, and why it is an important event (7). Users can find out about the live webcast that will begin on June 7, 2004 from Athens, Greece. Educators can find student activities developed to integrate discussions into the classroom. Lastly, Willie Koorts, an employee at the South African Astronomical Observatory, recounts the observations of scientists in Africa of the last transit of Venus (8). The site contains many historical photographs along with informational diagrams and figures.

80

Stripe disordering transition  

SciTech Connect

We have recently begun Monte Carlo simulations of the dynamics of stripe phases in the cuprates. A simple model of spinodal decomposition of the holes allows us to incorporate Coulomb repulsion and coherency strains. We find evidence for a possible stripe disordering transition, at a temperature below the pseudogap onset. Experimental searches for such a transition can provide constraints for models of stripe formation. (c) 1999 American Institute of Physics.

Markiewicz, R. S. [Physics Department, Northeastern U., Boston, Masschusetts 02115 (United States); Barnett Institute, Northeastern U., Boston, Masschusetts 02115 (United States); Vaughn, M. T. [Physics Department, Northeastern U., Boston, Masschusetts 02115 (United States)

1999-09-01

81

The Maize Floral Transition  

Microsoft Academic Search

\\u000a The floral transition is a critical developmental change in a plant's life cycle that is marked by the switch from vegetative\\u000a to reproductive growth. The transition is induced by leaf-derived signals that translocate through the phloem to the shoot\\u000a apex where the shoot apical meristem is reprogrammed to adopt a floral fate. In maize, this occurs when the vegetative shoot

Joseph Colasanti; Michael Muszynski

82

Care transitions: integrating transition theory and complexity science concepts.  

PubMed

Care transitions, defined as hospital discharge or movement from one health care setting to another, are currently a major concern of health care providers and policy makers. Extensive empirical research has been conducted on care transitions, but the theoretical foundations are rarely made explicit. We propose that integrating concepts on complex adaptive systems from complexity science with classic theory on transitions in nursing provides a powerful new lens through which to study care transitions and improve transition outcomes. We summarize concepts from both theoretical approaches, propose an expanded model of transitions, and apply the model to the transition from hospital to home. PMID:22869210

Geary, Carol R; Schumacher, Karen L

83

Venus Transit 2004  

NASA Astrophysics Data System (ADS)

December 6th, 1882 was the last transit of the planet Venus across the disk of the sun. It was heralded as an event of immense interest and importance to the astronomical community as well as the public at large. There have been only six such occurrences since Galileo first trained his telescope on the heavens in 1609 and on Venus in 1610 where he concluded that Venus had phases like the moon and appeared to get larger and smaller over time. Many historians consider this the final nail in the coffin of the Ptolemaic, Earth centered solar system. In addition, each transit has provided unique opportunities for discovery such as measurement and refinement of the astronomical unit, calculation of longitudes on the earth, and detection of Venus' atmosphere. The NASA Sun Earth Connection Education Forum in partnership with the Solar System Exploration Forum, DPS, and a number of NASA space missions is developing plans for an international education program centered around the June 8, 2004 Venus transit. The transit will be visible in its entirety from Europe and partially from the East Coast of the United States. We will use a series of robotic observatories including the Telescopes In Education network distributed in latitude to provide observations of the transit that will allow middle and high school students to calculate the A.U. through application of parallax. We will also use Venus transit as a probe of episodes in American history (e.g. 1769: revolutionary era, 1882: post civil war era, and 2004: modern era). Museums and planetariums in the US and Europe will offer real time viewing of the transit and conduct educational programs through professional development seminars, public lectures, and planetarium shows. We are interested in soliciting advice from the research community to coordinate professional research interests with this program.

Mayo, L. A.; Odenwald, S. F.

2002-09-01

84

Transition from School to Work.  

ERIC Educational Resources Information Center

This brief informational flyer presents practical information on the transition from school to work for students who are deaf-blind or have other severe disabilities. After defining transition, the flyer offers guidelines on: the age at which transition services should be started, areas that should be considered in a coordinated transition plan,…

Milner, Eileen R.

1995-01-01

85

Examining hydrogen transitions.  

SciTech Connect

This report describes the results of an effort to identify key analytic issues associated with modeling a transition to hydrogen as a fuel for light duty vehicles, and using insights gained from this effort to suggest ways to improve ongoing modeling efforts. The study reported on here examined multiple hydrogen scenarios reported in the literature, identified modeling issues associated with those scenario analyses, and examined three DOE-sponsored hydrogen transition models in the context of those modeling issues. The three hydrogen transition models are HyTrans (contractor: Oak Ridge National Laboratory), MARKAL/DOE* (Brookhaven National Laboratory), and NEMS-H2 (OnLocation, Inc). The goals of these models are (1) to help DOE improve its R&D effort by identifying key technology and other roadblocks to a transition and testing its technical program goals to determine whether they are likely to lead to the market success of hydrogen technologies, (2) to evaluate alternative policies to promote a transition, and (3) to estimate the costs and benefits of alternative pathways to hydrogen development.

Plotkin, S. E.; Energy Systems

2007-03-01

86

Perspective: The glass transition.  

PubMed

We provide here a brief perspective on the glass transition field. It is an assessment, written from the point of view of theory, of where the field is and where it seems to be heading. We first give an overview of the main phenomenological characteristics, or "stylised facts," of the glass transition problem, i.e., the central observations that a theory of the physics of glass formation should aim to explain in a unified manner. We describe recent developments, with a particular focus on real space properties, including dynamical heterogeneity and facilitation, the search for underlying spatial or structural correlations, and the relation between the thermal glass transition and athermal jamming. We then discuss briefly how competing theories of the glass transition have adapted and evolved to account for such real space issues. We consider in detail two conceptual and methodological approaches put forward recently, that aim to access the fundamental critical phenomenon underlying the glass transition, be it thermodynamic or dynamic in origin, by means of biasing of ensembles, of configurations in the thermodynamic case, or of trajectories in the dynamic case. We end with a short outlook. PMID:23556751

Biroli, Giulio; Garrahan, Juan P

2013-03-28

87

Lb2 satellites spectra emitted due to N - shell spectator vacancy  

NASA Astrophysics Data System (ADS)

Lb2 satellites spectra emitted due to N - shell spectator vacancy SURENDRA POONIA Division of Natural Resources and Environment, Central Arid Zone Research Institute, Jodhpur - 342 003, Rajasthan, India Telephone No. +91-0291-514692, Fax No. +91-0291-745089 E - mail: asrao@cazri.raj.nic.in PACS No. 32.20Rj and 78.70E Key words: Lb2 satellites, N vacancy Lb2 transitions. ABSTRACT: The X-ray satellite spectra arising due to 2p3/2-14x-1-4x-14d-1 (x = s, p, d) transition array, in the elements Z = 40 to 92, have been calculated. While the energies of various transitions of the array have been determined by using available Hartree-Fock-Slater (HFS) data on 1s-1-2p-14x-1 and 2p-1-4x-14d-1 Auger transition energies and their relative intensities have been estimated by considering cross - sections of singly ionized 2x-1 (x = s, p) states and then of subsequent Coster-Kronig and shake off processes. The calculated spectra have been compared with the measured satellite energies in Lb2 spectra. Their intense peaks have been identified as the observed satellite lines. The one to one correspondence between the peaks in calculated spectra and the satellites in measured spectra has been established on the basis of the agreement between the separations in the peak energies and those in the measured satellite energies. It has been established that two satellites observed in the Lb2 region of the X-ray spectra of various elements and named b20 and b2(a) in order of increasing energy are mainly emitted by 2p-14d-1-4d-2 transitions. Considering the relative intensities of these transitions and the mutual closeness in their energies, the most intense one, namely the 3F4-3F4, and seven others of this array have been associated with the emission of the satellite b2(a), reported in the spectra of elements with Z < 60. In the range Z > 70, the second most intense transition, namely the 1D2-1D2, and a comparatively weaker transition, namely the 3D3-3P2 one, deviate from this group. Hence, only six transitions superpose to give rise to this satellite, which has been named as b20, in case of elements with Z > 70, in the literature. In the range Z > 65, this satellite gets an added intensity due to the superposition of some intense transitions 2p-14f-1-4d-14f-1 array. This superposition of two arrays in high Z elements justifies the name b20 different from b2(a), given to the analogously placed satellite in the spectra of lower Z elements. Finally, the four closely spaced satellites, reported in the b2 region of the spectrum 46Pd have been assigned to suitable 2p-14x-1-4x-14d-1 (x = s, p, d) transitions. REFERENCES: 1.Y. Cauchois and C. Senemaud, X-Ray wavelength Tables, 2nd ed., (Oxford: Pergamon) pp. 217-314, (1978). 2.S. N. Soni and M. H. Massoud, J. Phys. Chem. Solids 58(1), 145-151 (1997). 3.S. N. Soni and S. Poonia, J. Phys. Chem. Solids 61(9), 1509-1518 (2000). 4.S. Poonia and S. N. Soni, J. Phys. Chem. Solids 62(3), 503-511 (2001). 5.A. M. Vlaicu, T. Tochio, T. Ishizuka, D. Ohsawa, Y. Ito, T. Mukoyama, A. Nisawa, T. Shoji and S. Yoshikado, Phys. Rev. A 58(5), 3544-3551, (1998). 6.R. Diamant, S. Huotari, K. Hamalainen, R. Sharon, C. C. Kao and M. Deutsch, Phys. Rev. A 63(2), 2508-2513 (2001).

Poonia, Surendra

2003-05-01

88

Sudden gravitational transition  

SciTech Connect

We investigate the properties of a cosmological scenario which undergoes a gravitational phase transition at late times. In this scenario, the Universe evolves according to general relativity in the standard, hot big bang picture until a redshift z < or approx. 1. Nonperturbative phenomena associated with a minimally-coupled scalar field catalyzes a transition, whereby an order parameter consisting of curvature quantities such as R{sup 2}, R{sub ab}R{sup ab}, R{sub abcd}R{sup abcd} acquires a constant expectation value. The ensuing cosmic acceleration appears driven by a dark-energy component with an equation-of-state w<-1. We evaluate the constraints from type 1a supernovae, the cosmic microwave background, and other cosmological observations. We find that a range of models making a sharp transition to cosmic acceleration are consistent with observations.

Caldwell, Robert R. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755 (United States); Komp, William [Physics Department, University of Louisville, 102 Natural Sciences, Louisville, Kentucky 40292 (United States); Parker, Leonard [Physics Department, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States); Vanzella, Daniel A. T. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo (IFSC-USP), Av. Trabalhador Sao-carlense, 400 Cx. Postal 369 - CEP 13560-970, Sao Carlos, Sao Paulo (Brazil)

2006-01-15

89

1D Quantum Transitions Applet  

NSDL National Science Digital Library

This simulation explores the transitions between quantum states in a number of 1D systems. The time-dependent wavefunction is displayed. An electric field resonant with the transition between states is applied and the changes in the wavefunction with time are tracked. The dipole transition probability is displayed for different initial to final state transitions, and the user may select the transition they wish to observe.

Falstad, Paul

2004-05-17

90

Electroweak phase transitions  

SciTech Connect

An analytic treatment of the one Higgs doublet, electroweak phase transition is given. The phase transition is first order, occurs by the nucleation of thin walled bubbles and completes at a temperature where the order parameter, {l_angle}{phi}{r_angle}{sub T} is significantly smaller than it is when the origin becomes absolutely unstable. The rate of anomalous baryon number violation is an exponentially function of {l_angle}{phi}{r_angle}{sub T}. In very minimal extensions of the standard model it is quite easy to increase {l_angle}{phi}{r_angle}{sub T} so that anomalous baryon number violation is suppressed after completion of the phase transition. Hence baryogenesis at the electroweak phase transition is tenable in minimal of the standard model. In some cases additional phase transitions are possible. For a light Higgs boson, when the top quark mass is sufficiently large, the state where the Higgs field has a vacuum expectation value {l_angle}{phi}{r_angle} = 246 GeV is not the true minimum of the Higgs potential. When this is the case, and when the top quark mass exceeds some critical value, thermal fluctuations in the early universe would have rendered the state {l_angle}{phi}{r_angle} = 246 GeV unstable. The requirement that the state {l_angle}{phi}{r_angle} = 246 GeV is sufficiently long lived constrains the masses of the Higgs boson and the top quark. Finally, we consider whether local phase transitions can be induced by heavy particles which act as seeds for deformations in the scalar field.

Anderson, G.W.

1991-09-16

91

Electroweak phase transitions  

SciTech Connect

An analytic treatment of the one Higgs doublet, electroweak phase transition is given. The phase transition is first order, occurs by the nucleation of thin walled bubbles and completes at a temperature where the order parameter, {l angle}{phi}{r angle}{sub T} is significantly smaller than it is when the origin becomes absolutely unstable. The rate of anomalous baryon number violation is an exponentially function of {l angle}{phi}{r angle}{sub T}. In very minimal extensions of the standard model it is quite easy to increase {l angle}{phi}{r angle}{sub T} so that anomalous baryon number violation is suppressed after completion of the phase transition. Hence baryogenesis at the electroweak phase transition is tenable in minimal of the standard model. In some cases additional phase transitions are possible. For a light Higgs boson, when the top quark mass is sufficiently large, the state where the Higgs field has a vacuum expectation value {l angle}{phi}{r angle} = 246 GeV is not the true minimum of the Higgs potential. When this is the case, and when the top quark mass exceeds some critical value, thermal fluctuations in the early universe would have rendered the state {l angle}{phi}{r angle} = 246 GeV unstable. The requirement that the state {l angle}{phi}{r angle} = 246 GeV is sufficiently long lived constrains the masses of the Higgs boson and the top quark. Finally, we consider whether local phase transitions can be induced by heavy particles which act as seeds for deformations in the scalar field.

Anderson, G.W.

1991-09-16

92

China's urban transition.  

PubMed

This article describes recent changes in urban patterns in Shanghai-Nanjing, Beijing-Tianjin-Tangshan, Canton-Hong Kong, and Dalian-Shenyang. The urban patterns in these metropolitan areas are viewed as part of an urban transition that is responding to population growth, a structural shift in employment, relaxed rules on migration and household registration, and foreign investment and trade. It is argued that these metropolitan coastal areas will form the key growth centers and will lead China's economic development. Urban transition is defined as the shift from rural to urban and from agricultural employment to industrial, commercial, or service employment. China's large cities always dominated as important centers of politics and trade. The recent shift is from interior to coastal cities due to a new world view and a movement away from the isolationism of prior centuries. It is assumed that cities are formed to take advantage of economies of scale in production, consumption, and distribution and to conform to regional specialization. Governments can intervene in growth processes. China's development of cities reflects state controls and market forces. The size and scale of China's population influenced the development process, which resulted in differences in the shape and process of the urban transition. It was under Chinese communism that cities became more than a set of discrete regional urban systems. Reference is made to Oshima's model of change that is specific to monsoon countries. Oshima argues that monsoon agricultural conditions require a distinct strategy based on full employment in order to achieve industrial transition. Rice cultivation requires a large and disciplined labor force. The discussion focuses on other models as well, such as the McGee's model of the extended metropolis and its extension by Zhou Yixing to China. China's changes may not follow Skeldon's models of urbanization in developing countries, because of state control of migration. However, the longer migrants remain in cities the more likely Skeldon's models of early European transitions apply to China's urban transition. PMID:12178548

Pannell, C

93

Transit of Mercury  

NSDL National Science Digital Library

It isn't every day that one gets to view a transit of Mercury. In fact, it's an event that only occurs approximately twelve times a century. For those of you who missed this event on November 8th, the researchers and scientists at the Exploratorium in San Francisco have created this program that contains the complete event and offer it to visitors to this lovely website. The transit was recorded from Kitt Peak in Arizona, and visitors to the site can watch a brief introduction to the program, and then watch various images from the webcast, complete with audio commentary at the beginning of each hour of coverage.

2006-01-01

94

Bottomonium dipion transitions  

SciTech Connect

Dipion transitions of the subthreshold bottomonium levels {upsilon}(nS){yields}{upsilon}(n{sup '}S){pi}{pi} with n>n{sup '}, n=2, 3, 4 n{sup '}=1, 2 are studied in the framework of the chiral decay Lagrangian, derived earlier. The channels BB, BB*+c.c., B*B* are considered in the intermediate state and realistic wave functions of {upsilon}(nS), B and B* are used in the overlap matrix elements. Imposing the Adler zero requirement on the transition matrix element, one obtains 2d and 1d dipion spectra in reasonable agreement with experiment.

Simonov, Yu. A.; Veselov, A. I. [ITEP, Moscow (Russian Federation)

2009-02-01

95

Transit and safety  

NASA Astrophysics Data System (ADS)

The US Navy Transit satellite-navigation system is characterized, with a focus on its use by civil customers to provide accurate position data to aid in their rescue at sea or in remote land regions. The operating principles of the system are reviewed; the simplicity and low cost of the Transit receiver is emphasized; and its advantages over transponder-type satellite search-and-rescue systems such as Sarsat or more complicated satellite navigation systems such as Navstar/GPS are indicated. The need for a purely civil GPS (such as the Navsat system planned by ESA) which is not subject to military priorities or cancellation is stressed.

Blanchard, W. F.

96

Strong M2 transitions  

NASA Astrophysics Data System (ADS)

The recommended upper limit (RUL) for isospin-allowed M2 ?-ray transition strengths is largely determined by the strongest observed M2 transitions. In order to check this M2 RUL the strengths of the five strongest reported primary M2 transitions have been remeasured via (p, ?) reactions. The results are: 14N, Ex = 8.91 --> 0 MeV: 2.2 +/- 0.3 W.u.; 16O, Ex = 12.97 --> 0 MeV: 1.0 +/- 0.3 W.u.; 16O, Ex = 12.53 --> 0 MeV: 1.12 +/- 0.17 W.u.; 21Na, Ex = 2.80 --> 0.33 MeV: <0.4 W.u.; 32S, Ex = 10.08 --> 0 MeV: 0.93 +/- 0.13 W.u. Although all but one of these new M2 strengths are lower than the previously reported values, the M2 RUL of 3 W.u. for nuclei with A = 6-44 cannot be reduced due to the strong transition in 14N.

Zijderhand, F.; van der Leun, C.

1986-12-01

97

Singing Smoothes Classroom Transitions  

ERIC Educational Resources Information Center

|Just as humming a merry tune helped Snow White and her furry animal friends to quickly clean a filthy cottage in the movie "Snow White and the Seven Dwarfs" (Disney & Cottrell, 1937), singing can be an effective way to help keep young children fully engaged during classroom transitions. The purposes of this article are to: (1) consider why…

Mathews, Sarah E.

2012-01-01

98

MONGOLIAN RANGELANDS IN TRANSITION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mongolia has a rich history and diverse, expansive rangelands. Mongolia's rangelands have always been publicly owned, but their management has changed with the country's governing structure. In its transition from a centrally controlled economy to a market economy since 1990, livestock production ...

99

Planning rapid transit networks  

Microsoft Academic Search

Rapid transit construction projects are major endeavours that require long-term planning by several players, including politicians, urban planners, engineers, management consultants, and citizen groups. Traditionally, operations research methods have not played a major role at the planning level but several tools developed in recent years can assist the decision process and help produce tentative network designs that can be submitted

G. Laporte; J. A. Mesa; F. A. Ortega; F. Perea

2011-01-01

100

Transition Fault Simulation  

Microsoft Academic Search

Delay fault testing is becoming more important as VLSI chips become more complex. Components that are fragments of functions, such as those in gate-array designs, need a general model of a delay fault and a feasible method of generating test patterns and simulating the fault. The authors present such a model, called a transition fault, which when used with parallel-pattern,

John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

1987-01-01

101

Transition temperature in QCD  

NASA Astrophysics Data System (ADS)

We present a detailed calculation of the transition temperature in QCD with two light and one heavier (strange) quark mass on lattices with temporal extent N?=4 and 6. Calculations with improved staggered fermions have been performed for various light to strange quark mass ratios in the range, 0.05?m^l/m^s?0.5, and with a strange quark mass fixed close to its physical value. From a combined extrapolation to the chiral (m^l?0) and continuum (aT?1/N??0) limits we find for the transition temperature at the physical point Tcr0=0.457(7) where the scale is set by the Sommer-scale parameter r0 defined as the distance in the static quark potential at which the slope takes on the value, (dVq¯q(r)/dr)r=r0=1.65/r02. Using the currently best known value for r0 this translates to a transition temperature Tc=192(7)(4)MeV. The transition temperature in the chiral limit is about 3% smaller. We discuss current ambiguities in the determination of Tc in physical units and also comment on the universal scaling behavior of thermodynamic quantities in the chiral limit.

Cheng, M.; Christ, N. H.; Datta, S.; van der Heide, J.; Jung, C.; Karsch, F.; Kaczmarek, O.; Laermann, E.; Mawhinney, R. D.; Miao, C.; Petreczky, P.; Petrov, K.; Schmidt, C.; Umeda, T.

2006-09-01

102

Transition Mixing Study.  

National Technical Information Service (NTIS)

A computer model capable of analyzing the flow field in the transition liner of small gas turbine engines is developed. A FORTRAN code has been assembled from existing codes and physical submodels and used to predict the flow in several test geometries wh...

R. Reynolds C. White

1986-01-01

103

Nutrition transition in India  

Microsoft Academic Search

Objective: The primary objective of this review is to examine the demographic and nutrition transition in India in relation to its contribution to the emerging epidemic of chronic non-communicable diseases in this country. Setting: India, the country as a whole and its different states with a population exceeding 1 billion in 2001. Subjects: The review examines demographic changes in the

Prakash S Shetty

2002-01-01

104

Venus Transit 2004  

Microsoft Academic Search

December 6th, 1882 was the last transit of the planet Venus across the disk of the sun. It was heralded as an event of immense interest and importance to the astronomical community as well as the public at large. There have been only six such occurrences since Galileo first trained his telescope on the heavens in 1609 and on Venus

L. A. Mayo; S. F. Odenwald

2002-01-01

105

The Transition to Coal.  

National Technical Information Service (NTIS)

The basic energy problem facing the U.S. and other industrialized nations is not to secure independence from foreign energy suppliers, but instead to negotiate an orderly transition from primary reliance on fossil oil and gas resources to predominant use ...

R. F. Naill J. S. Miller D. L. Meadows

1974-01-01

106

Transition Tasks and Resources  

Microsoft Academic Search

This paper examines the transition of twelfth grade students graduating from high school. The authors followed two groups, one drawn from mainstream educational programs, and the other from special education programs for students with learning disabilities or behavioral disorders. Participants were followed from the last semester of their senior year until six months following their graduation from high school. The

Charles Barone; Edison J. Trickett; Kathleen D. Schmid; Peter E. Leone

1994-01-01

107

Frames with Transitive Structures  

Microsoft Academic Search

A classical result in the theory of uniform spaces is that any topological space with a base of clopen sets admits a uniformity with a transitive base and the uniform topology of such a space has a base of clopen sets. This paper presents a pointfree generalization of this, both to uniform and quasi-uniform frames, together with various properties concerning

Worthen Hunsaker; Jorge Picado

2002-01-01

108

The Economics of Transition  

Microsoft Academic Search

Two major socioeconomic events occurred in the 20th century: the creation of the centrally planned economy (CPE) in the late 1920's and the dismantling of the CPE and its replacement with markets, after both the fall of the Berlin Wall in 1989 and the break- up of the Soviet Union in 1991. Directly affected by this transition are the twenty-nine

Robert E. Litan; Barbara G. Katz

1996-01-01

109

Indexing Transitional Knowledge  

Microsoft Academic Search

Various indexes have been proposed to mark when a child is on the verge of acquiring new knowledge. This article described a new method for indexing this point of transition, which is based on the specificity of children's verbal explanations. The degree to which children were specific in their verbal explanations was related to whether they benefited from instruction. In

Theresa Graham; Michelle Perry

1993-01-01

110

Boundary layer transition studies  

Microsoft Academic Search

A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation\\/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner &

Jonathan H. Watmuff

1995-01-01

111

Transitions in Higher Education  

ERIC Educational Resources Information Center

|This paper offers ideas towards a solution of some of the problems that arise due to the extension of higher education to an ever wider range of students: especially student drop-out. It suggests that, as far as is practical, the design and delivery of higher education should be based upon the major changes or transitions which the students…

Hussey, Trevor; Smith, Patrick

2010-01-01

112

The crumpling transition revisited  

Microsoft Academic Search

The ``crumpling'' transition, between rigid and crumpled surfaces, has been object of much discussion over the past years. The common lore is that such transtion should be of second order. However, some lattice versions of the rigidity term on fixed connectivity surfaces seem to suggest that the trnsition is of higher order instead. While some models exhibit what appear to

M. Baig; D. Espriu

1993-01-01

113

Mass Transit in Anchorage.  

National Technical Information Service (NTIS)

The study is an analysis of the mass transit situation in Anchorage with particular emphasis on the bus system or People Mover. The purpose of the study is to determine how the services provided by the people mover affect present and potential Riders, and...

T. G. Eschenbach G. A. Geistauts

1977-01-01

114

The contact percolation transition  

NASA Astrophysics Data System (ADS)

Typical quasistatic compression algorithms for generating jammed packings of athermal, purely repulsive particles begin with dilute configurations and then apply successive compressions with relaxation of the elastic energy allowed between each compression step. It is well-known that during isotropic compression athermal systems with purely repulsive interactions undergo a jamming transition at packing fraction ?J from an unjammed state with zero pressure to a jammed, rigid state with nonzero pressure. Using extensive computer simulations, we show that a novel second-order-like, contact percolation, which signals the formation of a system-spanning cluster of mutually contacting particles, occurs at ?P< ?J, preceding the jamming transition. By measuring the number of non-floppy modes of the dynamical matrix, the displacement field between successive compression steps, and the overlap between the adjacency matrix, which represents the network of contacting grains, at ? and ?J, we find that the contact percolation transition also heralds the onset of nontrivial response to applied stress. Highly heterogeneous, cooperative, and non-affine particle motion occurs in unjammed systems significantly below the jamming transition for ?P< ?< ?J,

Shen, Tianqi; O'Hern, Corey; Shattuck, Mark

2012-02-01

115

Augmented Cognition Transition.  

National Technical Information Service (NTIS)

This report details the work done by Honeywell Aerospace Advanced Technology to address two key challenges in the transition of Augmented Cognition (AugCog) technology to the Army's Future Force: 1) integration of the Honeywell AugCog system into the Futu...

J. B. Sampson M. C. Dorneich P. M. Ververs S. Mathan S. D. Whitlow

2009-01-01

116

Boundary layer transition  

Microsoft Academic Search

The boundary layer stability, its active control by sound and surface heating and the effect of curvature are studied numerically and experimentally for subsonic flow. In addition, the experimental and flight test data are correlated using the stability theory for supersonic Mach numbers. Active transition fixing and feedback control of boundary layer by sound interactions are experimentally investigated at low

L. Maestrello; A. Bayliss; S. M. Mangalam; M. R. Malik

1986-01-01

117

Exoplanet Detection: Transit Method  

NSDL National Science Digital Library

The Exoplanet Detection: Transit Method model simulates the detection of exoplanets by using the transit method of detecting exoplanets. In this method, the light curve from a star, and how it changes over time due to exoplanet transits, is observed and then analyzed. In this simulation the exoplanet orbits the star (sun-sized) in circular motion via Kepler's third law.  When the exoplanet passes in front of the star (transits), it blocks part of the starlight. This decrease in starlight is shown on the graph.  If the exoplanet is close enough to the central star, and has sufficient reflectivity, or albedo, it can reflect enough of the starlight to be seen on the light curve. In the simulation the star-exoplanet system is shown as seen from Earth (edge on view) but magnified greatly, and with the star and planet sizes not shown to the scale of the orbit. The radius of the central star (relative to the radius of Sun),semi-major axis of the exoplanet (in AU), radius of the exoplanet (relative to the radius of Jupiter), the exoplanet's albedo (reflectivity), and the inclination of the system relative to Earth can be changed. The simulation uses Java 3D, if installed, to render the view the star and exoplanet. If Java 3D is not installed, the simulation will default to simple 3D using Java.

Belloni, Mario

2010-06-29

118

Modeling Anticipatory Event Transitions  

Microsoft Academic Search

Major world events such as terrorist attacks, natural disasters, wars, etc. typically progress through various representative stages\\/states in time. For example, a volcano eruption could lead to earthquakes, tsunamis, aftershocks, evacuation, rescue efforts, international relief support, rebuilding, and resettlement, etc. By analyzing various types of catastrophical and historical events, we can derive corresponding event transition models to embed useful information

He Qi; Kuiyu Chang; Ee Peng LIM

2010-01-01

119

Triangle zigzag transition modeling  

NASA Astrophysics Data System (ADS)

Designing read-back subsystems in magnetic recording requires precise knowledge about the signal picked up by the reading head. As areal densities in longitudinal magnetic recording increase, the read-back signal becomes more corrupted by intersymbol interference, media noise, and intertrack interference. Due to the spatial distribution of transitions on a disk surface and the nonlinear character of bit interactions, two dimensional media plane models are widely used to model the write process. If a two dimensional (or three dimensional) read- head model is utilized, intertrack interferences are also observed. Micromagnetic media modeling, coupled with appropriate read-head models, have been successfully used to model the 'raw' magnetic recording channel. However, due to its high computational complexity, micromagnetic modeling is an impractical tool in statistical signal analyses such as error rate studies where thousands of transitions need to be created. We propose a much simpler, yet realistic, two dimensional write process model. We call it the triangle zig-zag transition (TZ- ZT) model since the transition boundary is modeled by lateral sides of isosceles triangles of alternating orientations truncated on a common basis line across the track width. Formulas are presented that relate the parameters of the model, the probability density function of triangle heights and the constant vertex angle, to the magnetization transition profile of an isolated transition and to the cross track correlation width, respectively. Although stochastic zig-zag models have been proposed in the past, our model has the advantage that it is stable across the track, that is, it is not an independent increment process and it therefore doesn't exhibit a cross track drift. Compared to micromagnetic modeling, the TZ-ZT model offers computational savings of 4 orders of magnitude, while transition shapes and media noise are modeled with comparable accuracy, as our results show. For these reasons, the TZ-ZT model, combined with an appropriate head-sensitivity function, is an attractive 'raw channel' model for applications such as statistical performance analyses where large numbers of bits are needed.

Kavcic, Aleksandar; Moura, Jose M.

1995-12-01

120

Alternative fuel transit buses: The Pierce Transit Success Story  

SciTech Connect

The Pierce transit program for operating mass transit buses on compressed natural gas (CNG) is described. Cost, reliability, fuel efficiency, emission of combustion products, and future trends are discussed.

NONE

1996-10-01

121

From transition paths to transition states and rate coefficients.  

PubMed

Transition states are defined as points in configuration space with the highest probability that trajectories passing through them are reactive (i.e., form transition paths between reactants and products). In the high-friction (diffusive) limit of Langevin dynamics, the resulting ensemble of transition states is shown to coincide with the separatrix formed by points of equal commitment (or splitting) probabilities for reaching the product and reactant regions. Transition states according to the new criterion can be identified directly from equilibrium trajectories, or indirectly by calculating probability densities in the equilibrium and transition-path ensembles using umbrella and transition-path sampling, respectively. An algorithm is proposed to calculate rate coefficients from the transition-path and equilibrium ensembles by estimating the frequency of transitions between reactants and products. PMID:15267886

Hummer, Gerhard

2004-01-01

122

High growth in China—Transition without a transition crisis?  

Microsoft Academic Search

Unlike other transition economies the People's Republic of China has so far not only avoided a severe transition crisis; it\\u000a has apparently also managed to make economic transition a source of growth. However, the country now faces a number of crucial\\u000a transition problems that centre around the debt situation of state-owned enterprises and the fragile condition of the financial\\u000a system.

Hansjörg Herr; Jan Priewe

1999-01-01

123

Bonding and phase transitions in transition metal dichalcogenide layer compounds  

Microsoft Academic Search

The electronic structure of the transition metal dichalcogenide layer compounds is studied using hybridised orbitals appropriate to the transition metal atom coordination. Non-bonding orbitals on the transition metal atoms give the conduction electron bands which are responsible for the charge-density-wave phase transitions in the VB compounds, and the band structure of 1T- and 2H-TaS2 is found using tight binding. The

J. E. Inglesfield

1980-01-01

124

Model of contact transitioning with \\  

Microsoft Academic Search

Arcing transition of metal-to-metal contacts is a key technical challenge in the development of railgun launchers. Theoretical understanding of the process remains poor and controversial. Several authors have explained transitioning by a velocity skin effect driven \\

John P. Barber; Yuri A. Dreizin

1995-01-01

125

Development of Standard Transit Profiles.  

National Technical Information Service (NTIS)

The California Department of Transportation project developed a single accessible transit data base which can be updated annually. This pilot data base includes a comprehensive printed listing of 287 public transit and paratransit operators including addr...

F. Markowitz J. Kaplan D. Landberg

1983-01-01

126

Transition from Hospital to Home  

MedlinePLUS Videos and Cool Tools

Experts \\ Transition from Hospital to Home Topics Adult Injuries Spinal Cord Injury 101 The Basics of SCI Rehabilitation Preventing Pressure Sores Transition from Hospital to Home Spasticity, Physical Therapy- ...

127

Bosonic fractionalisation transitions  

NASA Astrophysics Data System (ADS)

At finite density, charge in holographic systems can be sourced either by explicit matter sources in the bulk or by bulk horizons. In this paper we find bosonic solutions of both types, breaking a global U(1) symmetry in the former case and leaving it unbroken in the latter. Using a minimal bottom-up model we exhibit phase transitions between the two cases, under the influence of a relevant operator in the dual field theory. We also embed solutions and transitions of this type in M-theory, where, holding the theory at constant chemical potential, the cohesive phase is connected to a neutral phase of Schrödinger type, via a z = 2 QCP.

Adam, Alexander; Crampton, Benedict; Sonner, Julian; Withers, Benjamin

2013-01-01

128

The transition to agricultural sustainability  

PubMed Central

The transition to sustainable growth in agricultural production during the 21st century will take place within the context of a transition to a stable population and a possible transition to a stable level of material consumption. If the world fails to successfully navigate a transition to sustainable growth in agricultural production, the failure will be due more to a failure in the area of institutional innovation than to resource and environmental constraints.

Ruttan, Vernon W.

1999-01-01

129

Visual Analytics Technology Transition Progress  

SciTech Connect

The authors provide a description of the transition process for visual analytic tools and contrast this with the transition process for more traditional software tools. This paper takes this into account and describes a user-oriented approach to technology transition including a discussion of key factors that should be considered and adapted to each situation. The progress made in transitioning visual analytic tools in the past five years is described and the challenges that remain are enumerated.

Scholtz, Jean; Cook, Kristin A.; Whiting, Mark A.; Lemon, Douglas K.; Greenblatt, Howard

2009-09-23

130

Transitional Cell Carcinoma  

Microsoft Academic Search

Transitional cell carcinoma is a common urological malignancy and in up to 5% of cases occurs in the kidney. The multicentric\\u000a nature of TCC makes assessment of the entire urothelium essential prior to treatment. Vigilant urological and radiological\\u000a follow-up is also warranted post-treatment to assess for metachronous lesions and recurrence. Conventional imaging modalities,\\u000a such as IVU, RP, and US, still

Ronan F. Browne; William C. Torreggiani

131

Radar in transition  

Microsoft Academic Search

It is pointed out that radar engineers, at the end of 1984, find their field in transition between the conventional designs of the post War II era and the digitally controlled, solid-state systems which will be in place for the year 2000. The U.S. Navy has two major phased array radar systems in operation, including the rotating three-dimensional (3D) AN\\/SPS-48,

D. K. Barton

1984-01-01

132

Squeezing from ghost transitions  

Microsoft Academic Search

We show that significant squeezing in a strong signal light field can be generated with three-level atoms in a ghost-transition setup by tuning a weak probe beam inside the Autler-Townes doublet created by the strong signal light. Close to the Rabi level, i.e., within the absorption line, processes involving both amplitude quadratures become important. Significant atomic two-photon coherence provides a

Klaus M. Gheri; Daniel F. Walls

1994-01-01

133

Phase Transition Taylor Test  

Microsoft Academic Search

In this article, the Taylor impact test is applied to investigate the dynamic phase transformation behavior of NiTi alloy, which we call it the phase transition Taylor test (PTTT). The symmetry impact configuration is applied in the study at impact velocity range from 47m\\/s to 175m\\/s by using a light gas gun facility in this lab. The NiTi alloy is

Xinghua Zhang

2005-01-01

134

Venus Transit Observer  

NSDL National Science Digital Library

This Java applet shows the location in the sky of the Sun and Venus for any given location on Earth. The date and time can be set for past and future years, and the program indicates the rise, set, azimuth, and elevation for both celestial bodies. Details about Venus also include elongation from the Sun, distance from the Earth, and past and future transits across the Sun as seen from Earth (date, time, and year).

Giesen, Juergen

135

Epithelial-Mesenchymal Transitions  

Microsoft Academic Search

Epithelial-mesenchymal transitions (EMT) are vital for morphogenesis during embryonic development and are also implicated in the conversion of early stage tumors into invasive malignancies. Several key inducers of EMT are transcription factors that repress E-cadherin expression. A recent report in Cell(Yang et al., 2004) adds Twist to this list and links EMT to the ability of breast cancer cells to

Yibin Kang; Joan Massagué

2004-01-01

136

Radiative Transitions in Charmonium  

SciTech Connect

The form factors for the radiative transitions between charmonium mesons are investigated. We employ an anisotropic lattice using a Wilson gauge action, and domain-wall fermion action. We extrapolate the form factors to Q{sup 2} = 0, corresponding to a real photon, using quark-model-inspired functions. Finally, comparison is made with photocouplings extracted from the measured radiative widths, where known. Our preliminary results find photocouplings commensurate with these experimentally extracted values.

Jozef Dudek; Robert Edwards; David Richards

2005-10-01

137

The Electroweak Phase Transition  

Microsoft Academic Search

The electroweak phase transition is investigated by means of the perturbatively calculated high temperature effective potential. An analytic result to order $g^4,\\\\lambda^2$ is presented for the Abelian Higgs model, the SU(2)-Higgs model and the standard model and a complete on-shell renormalization at zero temperature is performed. Higher order corrections are found to increase the strength of the first order phase

A. Hebecker

1995-01-01

138

Modeling Anticipatory Event Transitions  

Microsoft Academic Search

Major world events such as terrorist attacks, natural disasters, wars, etc. typically progress through various representative\\u000a stages\\/states in time. For example, a volcano eruption could lead to earthquakes, tsunamis, aftershocks, evacuation, rescue\\u000a efforts, international relief support, rebuilding, and resettlement, etc. By analyzing various types of catastrophical and\\u000a historical events, we can derive corresponding event transition models to embed useful information

Qi He; Kuiyu Chang; Ee-peng Lim

2008-01-01

139

Transition Mathematics Project  

NSDL National Science Digital Library

The Transitions Math Project (TMP) aims to transition students in high school math to college-level math, without having to take remedial level math courses once they get to college. According to their site, "Twenty-two percent of college freshman need a remedial course in mathematics. In 2- year colleges the problem is even more acute." Visitors will learn in the "History" section of the "About TMP" link that since 2004, TMP has instituted three ways to help students improve their transition. First, they make clear expectations of teachers on what they must teach to prepare students for college-level math. Second, they inform parents and students what will be expected in college-level math, and finally, they establish networks between college and high school teachers to share teaching successes, techniques, and best practices. Visitors will find that the "Curriculum and Instructional Materials" section is a useful repository of curriculum and instructional resources created by TMP teams for use by all teachers. The site also provides professional development materials, TMP Resource Center, and links to their newsletter, math education news, and TMP's social media presence.

140

Dental Care Coverage Transitions  

PubMed Central

Objective To examine dental insurance transition dynamics in the context of changing employment and retirement status. Study Design Data from the Health and Retirement Study (HRS) were analyzed for individuals aged 51 years and older between the 2004 and 2006 waves of the HRS. Methods The primary focus of the analysis is the relationship between retirement and transitions in dental care coverage. We calculate and present bivariate relationships between dental coverage and retirement status transitions over time and estimate a multivariate model of dental coverage controlling for retirement and other potentially confounding covariates. Results We find that elderly adults are likely to lose their dental coverage upon entering retirement compared to those who remain in the labor force between waves of the HRS. While over half of those persons in the youngest age group (51 to 64) were covered over this entire period, two-thirds of those in the oldest age group 75 and over were without coverage over the same period. We observe a relatively high percentage of elderly persons flowing into and out of dental coverage over the period of our study similar to flows into and out of poverty. Conclusions Dental insurance is an important factor in the decision to seek dental care. Yet, no dental coverage is provided by Medicare, which provides medical insurance for nearly all Americans age 65 and older. This loss of coverage could lead to distortions in the timing of when to seek care, ultimately leading to worse oral and overall health.

Manski, Richard J.; Moeller, John; Chen, Haiyan; St. Clair, Patricia A.; Schimmel, Jody; Magder, Larry; Pepper, John V.

2010-01-01

141

Understanding the nutrition transition.  

PubMed

This article presents an overview of nutrition transition and experiences in China and Russia with monitoring of economic and health changes. Fogel (1994) showed that improvements in nutrition were associated with significant shifts in economic productivity. Over the past 300 years, the pace of dietary change has increased to some extent worldwide. Dietary changes are evident in changes in average stature and body composition and parallel major changes in health status. The nutrition transition follows the pattern of collecting food, famine, receding famine, degenerative disease, and behavioral change. The author's first proposition is that nutritional trends and dietary change are associated with population growth, age structure, and spatial distribution. Urban population has a distinctly different diet from rural population. Urban diets include superior grains, more milled and polished grains, higher fat content, more animal products, more sugar, and more prepared and processed food. Urban and rural diets are farther apart in low-income countries. The author's second proposition is that diet and activity are affected by income, patterns of work, and socioeconomic changes. Women's role changes affect household food preparation. Income allows for the purchase of goods or services that affect diet. Income increases are related to greater expenditures on food. The third proposition is that diet changes are associated with changes in knowledge and access to mass media. The last proposition is that interaction between epidemiological, socioeconomic, and demographic changes determines the nature and pace of nutrition transition. PMID:12178476

Popkin, B M

1996-09-01

142

Fuzzy processing in transitivity development  

Microsoft Academic Search

We review the literature on the development of transitive reasoning, and note three historical stages. Stage 1 was dominated by the Piagetian idea that transitive inference is logical reasoning in which relationships between adjacent terms figure as premises. Stage 2 was dominated by the information-processing view that memory for relationships between adjacent terms is determinative in transitivity performance. Stage 3

Valerie F. Reyna; Charles J. Brainerd

1990-01-01

143

Polyamorphic transitions in network glasses  

Microsoft Academic Search

We have used a combination of Brillouin and Raman scattering, and molecular dynamics computer simulations to investigate the nature of polyamorphic transitions in network glasses. The manifestation and consequence of pressure-induced structural transitions in silica and boron oxide, i.e., glasses with tetrahedral and trigonal network building blocks are contrasted. In both materials different transition mechanisms are observed depending on the

L. Huang; J. D. Nicholas; J. Kieffer; S. Sinogeikin; J. D. Bass

2004-01-01

144

Interest Groups and Presidential Transitions  

Microsoft Academic Search

The study of interest group behavior has focused on many tactical decisions, but not on the decision to participate in presidential transitions. This is a limitation because transitions are associated with policy change and are the first opportunity to influence a new president. This article develops a theory of interest group participation in presidential transitions through an original survey administered

Heath Brown

2011-01-01

145

Municipal Finance in Transitional Countries  

Microsoft Academic Search

This paper looks at how municipalities are financed in transitional and non- traditional economies. Transitional economies are moving from a traditional, planned or regulated economy to a free market economy. Transitional economies are also undergoing economic liberation by letting market forces set prices. These economies undergo restructuring and privatization by moving from the public to the private ownership of resources.

Harvey SCHWARTZ

146

Alameda-Contra Costa Transit District (AC Transit) Fuel Cell Transit Buses: Preliminary Evaluation Results  

SciTech Connect

This report provides an evaluation of three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, and six baseline diesel buses similar in design to the fuel cell buses.

Chandler, K.; Eudy, L.

2007-03-01

147

Fermionic quantum spin glass transitions  

NASA Astrophysics Data System (ADS)

This article reviews recent progress of the analytical theory of quantum spin glasses (QSG). Exact results for infinite range and one loop renormalisation group calculations for finite range models of either insulating or metallic type are presented. We describe characteristics of fermionic spin glass transitions and of fermionic correlations which are affected by these transitions and by spin glass order. Connections between tricritical thermal- and T=0 QSG transitions are described. A general phase diagram with tricritical QSG transitions caused either by random chemical potential or by elastic electron scattering, and implying discontinuous T=0-transitions in weak and in strong filling regimes, is also derived.

Oppermann, Reinhold; Rosenow, Bernd

148

22 CFR 41.71 - Transit aliens.  

Code of Federal Regulations, 2011 CFR

...2013-04-01 2013-04-01 false Transit aliens. 41.71 Section 41.71 Foreign Relations...IMMIGRATION AND NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliensâgeneral. An...

2013-04-01

149

MINEHOUND: transition to production  

NASA Astrophysics Data System (ADS)

The UK Department for International Development (DfID), in collaboration with the German Foreign Ministry (Auswärtiges Amt), contracted ERA Technology to carry out extensive field trials in Cambodia, Bosnia and Angola of an advanced technology, dual sensor, and hand-held landmine detector system called MINEHOUNDTM. This detector combines a metal detector with a Ground Penetrating Radar (GPR). As a result of extremely successful trials MINEHOUNDTM was developed as a product by ERA Technology and Vallon GmbH and has been available for sale since late 2006. This paper describes the transition to production of the detector.

Daniels, David J.; Curtis, Paul; Hunt, Nigel; Braunstein, Jürgen; Merz, Armin

2007-05-01

150

Transition to School  

Microsoft Academic Search

\\u000a Transition to school\\u000a \\u000a is one of the most important processes experienced by children and their families. In keeping with ecological models of child\\u000a development, a broad spectrum of factors is postulated to impact children’s adjustment to school. In this chapter, the biological\\u000a basis of early development as it impacts school adjustment\\u000a \\u000a is briefly reviewed, and a holistic, developmental concept of

Magdalena Janus

151

Electromagnetic transitions in hypernuclei  

SciTech Connect

The object of this review is to survey observations of electromagnetic transitions in hypernuclei and to point out contributions of these observations to an understanding of the effective two-body hyperon-nucleon forces in the nucleus. The discussion concentrates on lambda-hyperon nucleon potentials. Future plans for high resolution hypernuclear spectroscopy using Ge diode detectors is discussed, especially regarding the window of utility of such devices. Expected improvements in beam facilities are also reviewed. 9 refs., 4 figs., 1 tab. (DWL)

Chrien, R.E.

1986-01-01

152

Plasma inverse transition acceleration  

SciTech Connect

It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood, and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several realizations of the new principle.

Xie, Ming

2001-06-18

153

Transition Modeling in FLOWer — Transition Prescription and Prediction  

Microsoft Academic Search

This paper summarizes the developments of transition prescription and transition prediction techniques which were implemented\\u000a into the DLR Reynolds-averaged Navier-Stokes (RANS) solver FLOWer in the framework of the DLR projects MEGAFLOW and MEGAFLOW\\u000a II and the German research project MEGAFLOW. The very basic transition handling functionalities which FLOWer provided before\\u000a the projects started were generalized in order to prescribe arbitrary

A. Krumbein

154

Eccentric Planets & Transit Time Variation  

NASA Astrophysics Data System (ADS)

For an extrasolar planet on an eccentric orbit, the orbital velocity is constantly changing, even during a planetary transit. This changing orbital velocity will, in general, cause lightcurve assymetry. The asymmetry causes the mid-transit time to be slightly off-centre from the halfway point between transit ingress and egress. For GJ436b, we estimate that the mid-transit time is shifted by 20 seconds. In the case of a system experiencing secular changes, this difference will lead to a long period transit time variation (L-TTV) signal, under the typical definition of the mid-transit time. In this work, we describe the origins of the effect and evaluate it in the case of GJ436b experiencing hypothetical secular changes. We predict L-TTV could be used to map secular changes in such systems.

Kipping, David M.; Ribas, Ignasi; Font-Ribera, Andreu

2009-02-01

155

Partnership Transitions and Maternal Parenting.  

PubMed

We use data from the Fragile Families and Child Wellbeing Study (N = 1,975) to examine the association between mothers' partnership changes and parenting behavior during the first five years of their children's lives. We compare coresidential with dating transitions, and recent with more distal transitions. We also examine interactions between transitions and race/ethnicity, maternal education and family structure at birth. Findings indicate that both coresidential and dating transitions were associated with higher levels of maternal stress and harsh parenting; recent transitions had stronger associations than distal transitions. Maternal education significantly moderates these associations, with less educated mothers responding more negatively to instability in terms of maternal stress, and more educated mothers responding more negatively in terms of literacy activities. PMID:21423848

Beck, Audrey N; Cooper, Carey E; McLanahan, Sara; Brooks-Gunn, Jeanne

2010-04-01

156

Partnership Transitions and Maternal Parenting  

PubMed Central

We use data from the Fragile Families and Child Wellbeing Study (N = 1,975) to examine the association between mothers’ partnership changes and parenting behavior during the first five years of their children’s lives. We compare coresidential with dating transitions, and recent with more distal transitions. We also examine interactions between transitions and race/ethnicity, maternal education and family structure at birth. Findings indicate that both coresidential and dating transitions were associated with higher levels of maternal stress and harsh parenting; recent transitions had stronger associations than distal transitions. Maternal education significantly moderates these associations, with less educated mothers responding more negatively to instability in terms of maternal stress, and more educated mothers responding more negatively in terms of literacy activities.

Beck, Audrey N.; Cooper, Carey E.; McLanahan, Sara; Brooks-Gunn, Jeanne

2011-01-01

157

The Dutch Energy Transition Approach  

Microsoft Academic Search

\\u000a The term transition is employed by various scholars and organisations working on sustainable development. The first book containing\\u000a these terms was the book The Transition to Sustainability. The Politics of Agenda 21 in Europe, edited by Timothy O’Riordan and Heather Voisey, published in 1998. This book was followed by two other books which similar\\u000a titles: Our Common Journey: A transition

René Kemp

158

Quantum phase transition in space  

SciTech Connect

A quantum phase transition between the symmetric (polar) phase and the phase with broken symmetry can be induced in a ferromagnetic spin-1 Bose-Einstein condensate in space (rather than in time). We consider such a phase transition and show that the transition region in the vicinity of the critical point exhibits scalings that reflect a compromise between the rate at which the transition is imposed (i.e., the gradient of the control parameter) and the scaling of the divergent healing length in the critical region. Our results suggest a method for the direct measurement of the scaling exponent {nu}.

Damski, Bogdan [Los Alamos National Laboratory; Zurek, Wojciech H [Los Alamos National Laboratory

2008-01-01

159

Transit administration and planning research  

SciTech Connect

The 10 papers in the report deal with the following areas: Evaluation of demand-management strategies for Toledo's year 2010 transportation plan; Accommodating deaf and hard-of-hearing persons on public transportation systems in Massachusetts; Quick approach to compare highway and bus transit alternatives using the arterial analysis package; Panel survey approach to measuring transit route service elasticity of demand; UMTA and major investments: evaluation process and results; Using early performance to project transit route ridership: comparison of methods; Institutional requirements for competition: labor issues; Updating ride checks with multiple point checks; Producing section 15 service-consumed data: challenge for large transit; Parkrose targeted marketing campaign pass-incentive program.

de Corla-Souza; Gupta.

1989-01-01

160

Light Rail Transit Association  

NSDL National Science Digital Library

Light rail has been an effective form of transportation for many years, and it is quite common in the US and throughout Europe. The Web site of the Light Rail Transit Association (LRTA) has extensive news, historical background, and information about light rail systems. A good overview of light rail is given that outlines its advantages over other transportation methods. One of the best features of the site is its world systems list, which is frequently updated with new light rail projects across the globe. There are also photo galleries of several light rail cars in operation in different countries. Only members can access the LRTA magazines, but the rest of the site's resources are available to anyone.

1998-01-01

161

Radar in transition  

NASA Astrophysics Data System (ADS)

It is pointed out that radar engineers, at the end of 1984, find their field in transition between the conventional designs of the post War II era and the digitally controlled, solid-state systems which will be in place for the year 2000. The U.S. Navy has two major phased array radar systems in operation, including the rotating three-dimensional (3D) AN/SPS-48, and the phased-scanned AN/SPY-1 (Aegis) radars. The Aegis represents a major step beyond the conventional 3D and mechanical fire-control radars. However, it requires a special ship, dedicated to its use. Attention is given to questions regarding an extension of the application of Aegis technology to other U.S. Navy applications and to other navies, an ambitious solid-state radar program in the UK, and Army radars.

Barton, D. K.

1984-12-01

162

Steered transition path sampling.  

PubMed

We introduce a path sampling method for obtaining statistical properties of an arbitrary stochastic dynamics. The method works by decomposing a trajectory in time, estimating the probability of satisfying a progress constraint, modifying the dynamics based on that probability, and then reweighting to calculate averages. Because the progress constraint can be formulated in terms of occurrences of events within time intervals, the method is particularly well suited for controlling the sampling of currents of dynamic events. We demonstrate the method for calculating transition probabilities in barrier crossing problems and survival probabilities in strongly diffusive systems with absorbing states, which are difficult to treat by shooting. We discuss the relation of the algorithm to other methods. PMID:22779577

Guttenberg, Nicholas; Dinner, Aaron R; Weare, Jonathan

2012-06-21

163

Steered transition path sampling  

NASA Astrophysics Data System (ADS)

We introduce a path sampling method for obtaining statistical properties of an arbitrary stochastic dynamics. The method works by decomposing a trajectory in time, estimating the probability of satisfying a progress constraint, modifying the dynamics based on that probability, and then reweighting to calculate averages. Because the progress constraint can be formulated in terms of occurrences of events within time intervals, the method is particularly well suited for controlling the sampling of currents of dynamic events. We demonstrate the method for calculating transition probabilities in barrier crossing problems and survival probabilities in strongly diffusive systems with absorbing states, which are difficult to treat by shooting. We discuss the relation of the algorithm to other methods.

Guttenberg, Nicholas; Dinner, Aaron R.; Weare, Jonathan

2012-06-01

164

Phase transitions in DNA  

NASA Astrophysics Data System (ADS)

Experiments on light absorption in DNA solutions in the region of 260 nm demonstrate specific multiple sharp oscillations of dAdT vs temperature T, A being the optical density. A one-dimensional Ising model with a long-range polyspin interaction in an inhomogeneous "magnetic field" is used to present a quantitative description of these oscillations. An explicit analytical formula, derived in the paper, provides a surprisingly good agreement between the theory and experiments. It also alows one to obtain from these experiments important information about the sequence of the "magnetic fields," which represents the DNA component sequence. This is demonstrated by an example of a particular DNA. The long-range interaction in the Ising model implies a phase transition. Its nature is shown to depend crucially on well-defined properties of the DNA sequence.

Azbel, M. Ya.

1979-10-01

165

Transition to electronic publishing  

NASA Astrophysics Data System (ADS)

Previous communications have described some of the many changes that will occur in the next few months as AGU makes the transition to fully electronic publishing. With the advent of the new AGU electronic publishing system, manuscripts will be submitted, edited, reviewed, and published in electronic formats. This piece discusses how the electronic journals will differ from the print journals. Electronic publishing will require some adjustments to the ways we currently think about journals from our perspective of standard print versions. Visiting the Web site of AGU's Geochemistry, Geophysics, Geosystems (G-Cubed) is a great way to get familiar with the look and feel of electronic publishing. However, protocols, especially for citations of articles, are still evolving. Some of the biggest changes for users of AGU publications may be the lack of page numbers, the use of a unique identifier (DOI),and changes in citation style.

Bowning, Sam

166

?????(?,?') transition form factors  

NASA Astrophysics Data System (ADS)

The surprising results by the BABAR Collaboration on the ?? transition form factor require new thoughts about the high-Q2 dependence of the form factors with virtual photons. We make use of the anomaly sum rule [J. Horejsi and O. Teryaev, Z. Phys. C 65, 691 (1995).ZPCFD20170-973910.1007/BF01578676] which relates the hadron spectral density to the axial anomaly [S. Adler, Phys. Rev. 177, 2426 (1969); J. S. Bell and R. Jackiw, Nuovo Cimento A 60, 47 (1969).]. We study the quark-hadron duality relation for this sum rule and find out that the increase of the rescaled form factor Q2F??(Q2)˜log?(Q2) suggested by the BABAR data requires the presence of a 1/s-correction term in the relation between the one-loop spectral density and the hadron-continuum spectral density.

Melikhov, Dmitri; Stech, Berthold

2012-03-01

167

Transition Mathematics Project  

NSDL National Science Digital Library

The Transition Mathematics Project (TMP) was created in 2004 "to help students successfully progress from high school math to college-level math." Since its inception, TMP has worked with a range of partners including high school and college math educators. First-time visitors should check out the Resources area, which includes a number of useful tools such as "Agile Mind" (a web-based platform for educators to develop contextually rich math curricula and instructional materials). The Communication area features a semi-annual newsletter and a compilation of current "Math in the News" articles and publications related to TMP. The Results page features information about the successes of TMP's previous projects with progress reports and other documents.

168

STEM Colorado: Planetary Transits  

NSDL National Science Digital Library

This applet demonstrates how astronomers measure the properties of extra-solar planets by detecting planetary transits and eclipses. The applet shows a planet in orbit around a star. A graph plots the total brightness of the star as the planet orbits around it. The user can control the star's radius, the star's temperature, the planet's radius, the orbital radius and the albedo. The user can also see how the spectrum of the illuminated side of the planet, due to both the reflected starlight and the emitted planetary radiation, dependes on wavelength, albedo, and the parameters of the system. This is part of a larger collection of applets by STEM Colorado focused mostly on topics in astronomy.

Mccray, Richard; Koelemay, Andrew

2008-08-30

169

Wetting transitions of Ne  

NASA Astrophysics Data System (ADS)

We report studies of the wetting behavior of Ne on very weakly attractive surfaces, carried out with the grand canonical Monte Carlo method. The Ne-Ne interaction was taken to be of Lennard-Jones form, while the Ne-surface interaction was derived from an ab initio calculation of Chizmeshya et al. [J. Low Temp. Phys. 110, 677 (1998)]. Nonwetting behavior was found for Li, Rb, and Cs in the temperature regime explored (i.e., T<42 K). Drying behavior was manifested in a depleted fluid density near the Cs surface. In contrast, for the case of Mg (a more attractive potential) a prewetting transition was found near T=28 K. This temperature was found to shift slightly when a corrugated potential was used instead of a uniform potential. The isotherm shape and the density profiles did not differ qualitatively between these cases.

Bojan, M. J.; Stan, G.; Curtarolo, S.; Steele, W. A.; Cole, M. W.

1999-01-01

170

Texas Transition Model: School to Work Transition Curriculum.  

ERIC Educational Resources Information Center

|This manual provides a model for a transition plan for special needs learners in grades K-l2. The model is divided into four stages of transition: (1) the awareness stage, K-6, in which students are introduced to occupations and develop a knowledge base; (2) the exploration stage, 7-10, in which students identify a career goal, investigate…

Texas Univ., Austin. Extension Instruction and Materials Center.

171

Essentials of Transition Planning. Brookes Transition to Adulthood Series  

ERIC Educational Resources Information Center

|For young people with disabilities, crossing the bridge to adulthood will be empowering instead of intimidating--when their support teams know the essentials of effective transition planning. Now all the fundamentals of well-crafted transition plans are collected in one concise quick-guide, straight from one of the top authorities on helping…

Wehman, Paul

2011-01-01

172

Adolescents in transition: a look at a transitional treatment center.  

PubMed

This article describes the structure, philosophy, and goals of a high expectations halfway house program for adolescents. The Transitional Treatment Center (TTC) is a residential treatment program for emotionally disturbed adolescents making the transition from institutionalization to independent community life. Topics covered are specification of the TTC program objectives, methods for monitoring residents' progress towards resocialization and plans for future programming. PMID:10249060

Ehrlich, M I

1980-10-01

173

Transition to Employment. PRO-ED Series on Transition.  

ERIC Educational Resources Information Center

Part of a series designed to provide practical resources for transition personnel on a variety of topics critical to the process of preparing individuals with disabilities for adulthood, this guide focuses on transition to employment. Chapter 1, "Employment and Students with Disabilities," discusses the meaning of work in American society,…

Michaels, Craig A.

174

Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Preliminary Evaluation Results  

SciTech Connect

This report provides preliminary results from a National Renewable Energy Laboratory evaluation of a protoptye fuel cell transit bus operating at Connecticut Transit in Hartford. Included are descriptions of the planned fuel cell bus demonstration and equipment; early results and agency experience are also provided.

Chandler, K.; Eudy, L.

2008-10-01

175

Essentials of Transition Planning. Brookes Transition to Adulthood Series  

ERIC Educational Resources Information Center

For young people with disabilities, crossing the bridge to adulthood will be empowering instead of intimidating--when their support teams know the essentials of effective transition planning. Now all the fundamentals of well-crafted transition plans are collected in one concise quick-guide, straight from one of the top authorities on helping young…

Wehman, Paul

2011-01-01

176

Transit Switch Design Analysis (Phase 1). Transit Cooperative Research Program.  

National Technical Information Service (NTIS)

This report presents the results of a research task carried out under TCRP Project D7, Joint Rail Transit-Related Research with the Association of American Railroads/Transportation Technology Center, inc., Transit Switch Design Analysis (Phase 1). Under t...

S. P. Singh D. D. Davis S. Kalay

2003-01-01

177

Harmonic transition-state theory of thermal spin transitions  

NASA Astrophysics Data System (ADS)

A rate theory for thermally activated transitions in spin systems is presented. It is based on a transition-state approximation derived from Landau-Lifshitz equations of motion and quadratic expansion of the energy surface at minima and first order saddle points. While the flux out of the initial state vanishes at first order saddle points, the integrated flux over the hyperplanar transition state is nonzero and gives a rate estimate in good agreement with direct dynamical simulations of test systems over a range in damping constant. The preexponential factor obtained for transitions in model systems representing nanoclusters with 3 to 139 transition metal adatoms is on the order of 1011 to 1013s-1, similar to that of atomic rearrangements.

Bessarab, Pavel F.; Uzdin, Valery M.; Jónsson, Hannes

2012-05-01

178

An Introduction to Transit Marketing.  

National Technical Information Service (NTIS)

The report presents a general overview of the marketing process as applied to transit, to the value of marketing, and to the marketing plan and its components. It also presents some cautionary remarks about transit marketing. The report contains a selecte...

1975-01-01

179

Labor Relations in Urban Transit.  

National Technical Information Service (NTIS)

The study focuses on labor-management relations in the urban mass transit industry from 1960-1975, a period during which most of the major transit systems changed from private to public ownership and began receiving substantial funding from government. A ...

J. L. Stern R. U. Miller S. A. Rubenfeld C. A. Olson B. P. Heshizer

1977-01-01

180

Criteria for Feller transition functions  

Microsoft Academic Search

This paper presents some conditions for the minimal Q-function to be a Feller transition function, for a given q-matrix Q. We derive a sufficient condition that is stated explicitly in terms of the transition rates. Furthermore, some necessary and sufficient conditions are derived of a more implicit nature, namely in terms of properties of a system of equations (or inequalities)

Yangrong Li; Jia Li

2009-01-01

181

Stability of Generalized Transition Fronts  

Microsoft Academic Search

We study the qualitative properties of the generalized transition fronts for the reaction- diusion equations with the spatially inhomogeneous nonlinearity of the ignition type. We show that transition fronts are unique up to translation in time and are globally exponentially stable for the solutions of the Cauchy problem. The results hold for reaction rates that have arbitrary spatial variations provided

Antoine MelletJames Nolen; Jean-Michel Roquejore; Lenya Ryzhik

2009-01-01

182

The Glass Transition in Basalt  

Microsoft Academic Search

The glass transition has been experimentally detected in basalt as (1) an increase in the aggregate !inear thermal expansion coefficient al:, (2) an abrupt change in the temperature dependence of Young's modulus dE\\/dT, and (3) a change in stress relaxation behavior that effectively separates the T > T G and T < TG creep regimes. Transition temperatures determined by the

Michael P. Ryan; Charles G. Sammis

1981-01-01

183

Forbidden rotational transitions in molecules  

Microsoft Academic Search

The present state of theoretical and experimental research on forbidden rotational transitions in polar and nonpolar molecules, initiated mainly in 1971, is reviewed. Three mechanisms whereby forbidden rotational transitions appear are considered: 1) centrifugal distortion, 2) anharmonicity of the potential energy, 3) electron-vibrational interaction (the Jahn-Teller effect). A method is described for calculating the effective dipole moment and the strength

M R Aliev

1976-01-01

184

Partnership Transitions and Maternal Parenting  

ERIC Educational Resources Information Center

|We use data from the Fragile Families and Child Wellbeing Study (N = 1,975) to examine the association between mothers' partnership changes and parenting behavior during the first 5 years of their children's lives. We compare coresidential with dating transitions and recent with more distal transitions. We also examine interactions between…

Beck, Audrey N.; Cooper, Carey E.; McLanahan, Sara; Brooks-Gunn, Jeanne

2010-01-01

185

Liquid manipulation via morphological transitions  

Microsoft Academic Search

Liquid deposited on rectangular grooves, has a variety of possible liquid morphologies determined by the contact angle, theta, and the exact channel geometry. In our experiments, electrowetting is used to tune theta reversibly from 100 to 50 ^o, leading to a reversible transition between a drop- like morphology at large theta and extended liquid filaments for small theta. The transition

Ralf Seemann; Martin Brinkmann; Evgeny Gurevich; Stephan Herminghaus; Jean-Christophe Baret; Michel Decre

2006-01-01

186

Phase Transitions in Ionic Gels  

Microsoft Academic Search

The polymer network of a gel, under certain conditions, undergoes a discrete transition in equilibrium volume with changes in solvent composition or temperature. This Letter demonstrates that ionization of the gel network plays an essential role in the phase transition. The volume collapse is also observed when the pH within the gel is varied.

Toyoichi Tanaka; David Fillmore; Shao-Tang Sun; Izumi Nishio; Gerald Swislow; Arati Shah

1980-01-01

187

Phase transitions in ionic gels  

Microsoft Academic Search

It has been reported that under certain conditions the polymer network of acrylamide gels immersed in acetone—water mixtures undergoes a discrete transition in equilibrium volume with changes in acetone concentration or temperature. In the present work, the physical and chemical basis of this phase transition is identified. The magnitude of the collapse can increase substantially when a small percentage of

Toyoichi Tanaka; Shao-Tang Sun; Izumi Nishio; Gerald Swislow; Arati Shah

1980-01-01

188

Organizational Barriers to Transition: Summary.  

ERIC Educational Resources Information Center

|This study sought to identify the barriers that negatively impact the ability of disabled youth to successfully make a transition from school into employment and a quality adult life, and sought to specifically define organizational disincentives to successful transition. Current research is reviewed relating to organizational barriers to…

Haynes, John; Justice, Thomas I., Ed.

189

Identifying Non-transiting Terrestrial Planets with Transit Timing Data  

NASA Astrophysics Data System (ADS)

Both ground and space-based transit observatories are poised to significantly increase the number of known transiting planets and the number of precisely measured transit times. A planet's transit times represent a clock that can be used to infer the presence of additional planets. Although modeling the transit time variations (TTVs) of a known system is simple, interpreting those variations in terms of the mass and orbital elements of a perturbing planet is much more challenging. Because mutual planetary perturbations are often the dominant source of TTVs, the observable signal can be extremely complex. In these proceedings, we present early results based on a simplistic analysis of the root-mean-square TTV deviation amplitude. We are preparing a more thorough analysis based on a computationally efficient surrogate Bayesian model, which may be combined with analytic approximations and n-body integrations in order to establish the sensitivity of TTV observations to terrestrial-like planets as a function of the system architecture. Besides aiding the interpretation of future transit timing observations, we hope our results can help maximize the productivity of transit timing follow-up campaigns by guiding survey design decisions such as the choice of targets, required precision, and desired number/time span of TTV observations.

Veras, Dimitri; Ford, Eric B.

2009-02-01

190

Assessing transitional phenomena with the transitional object memory probe.  

PubMed

Winnicott's concept of transitional relatedness has captured the interest of psychoanalysts because it provides an understanding of the dialectical process occurring between inner and outer reality, and by extension, between analyst and analysand. Clinical observations related to transitional phenomena have led the authors to develop a projective early memory probe that assesses transitional phenomena. The transitional object early memory probe was tested both for its empirical validity and for its clinical utility in psychodynamic psychotherapy. Construct validity was assessed by comparing memory scores to the Rorschach Transitional Object Scale, as well as to therapist ratings of patient behaviors. Results demonstrated moderate correlations between early memory scores and Rorschach scale scores. Equally important was the finding that early memory scores were significantly correlated with therapist ratings of key behavioral patterns in therapy. A case vignette highlights the clinical application of the transitional object probe in assessing the capacity for transitional relatedness. In this case, the data gleaned from the patient's memories provided the therapist with a sharper focus on their role in the patient's growing capacity for more vital and creative contact with reality. PMID:9810109

Fowler, C; Hilsenroth, M J; Handler, L

1998-01-01

191

Sampling diffusive transition paths  

SciTech Connect

We address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with sampling infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with sampling the coarse features of long paths. The fine-features sampling stiffness is eliminated with the use of the fast sampling algorithm (FSA), and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. We use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature.

F. Miller III, Thomas; Predescu, Cristian

2006-10-12

192

Wetting Transition of Water  

NASA Astrophysics Data System (ADS)

Pure liquid water does not wet most solid surfaces. Liquid water on these surfaces beads up and forms droplets with a finite contact angle. General thermodynamic principles suggest that as the temperature approaches the critical point, the contact angle should go to zero, marking the wetting transition. We have made an optical cell which can operate near the critical point of water (Tc=373C, Pc=217 atm) to study this phenomenon on sapphire, graphite and silicon. We have used two methods to measure the wetting temperature of water on these surfaces. Firstly, we studied a single droplet on a horizontal surface and optically measured the change in contact angle as a function of increasing temperature. Second, we studied the condensation of droplets on a vertical plate as a function of temperature. As the temperature approached the wetting temperature in both cases, the droplets spread and eventually form a smooth film along the surface of the plate. The wetting temperature on sapphire is near 240C and is considerably higher on graphite. Our observed values of Tw are significantly higher than the predictions made by the sharp-kink approximation and recent molecular dynamics simulations.

Friedman, Serah; Khalil, Matt; Taborek, Peter

2013-03-01

193

Conifolds and geometric transitions  

NASA Astrophysics Data System (ADS)

Conifold geometries have recieved much attention in string theory and string-inspired cosmology recently, in particular the Klebanov-Strassler background that is known as the “warped throat.” This paper provides a pedagogical explanation for the singularity resolution in this geometry and emphasizes its connection to geometric transitions. The first part focuses on the gauge theory dual to the Klebanov-Strassler background, including the T-dual intersecting branes description. Then, a connection to the Gopakumar-Vafa conjecture for open-closed string duality is presented and a series of papers verifying this model on the supergravity level is summarized. An appendix provides extensive background material about conifold geometries. Special attention is given to their complex structures and the supersymmetry conditions on the background flux in constructions with fractional D3-branes on the singular (Klebanov-Tseytlin) and resolved (Pando Zayas-Tseytlin) conifolds are reevaluated. In agreement with earlier results, it is shown that only the singular solution allows a supersymmetric flux. However, the importance of using the correct complex structure to reach this conclusion is emphasized.

Gwyn, Rhiannon; Knauf, Anke

2008-10-01

194

Conifolds and geometric transitions  

SciTech Connect

Conifold geometries have recieved much attention in string theory and string-inspired cosmology recently, in particular the Klebanov-Strassler background that is known as the ''warped throat.'' This paper provides a pedagogical explanation for the singularity resolution in this geometry and emphasizes its connection to geometric transitions. The first part focuses on the gauge theory dual to the Klebanov-Strassler background, including the T-dual intersecting branes description. Then, a connection to the Gopakumar-Vafa conjecture for open-closed string duality is presented and a series of papers verifying this model on the supergravity level is summarized. An appendix provides extensive background material about conifold geometries. Special attention is given to their complex structures and the supersymmetry conditions on the background flux in constructions with fractional D3-branes on the singular (Klebanov-Tseytlin) and resolved (Pando Zayas-Tseytlin) conifolds are reevaluated. In agreement with earlier results, it is shown that only the singular solution allows a supersymmetric flux. However, the importance of using the correct complex structure to reach this conclusion is emphasized.

Gwyn, Rhiannon; Knauf, Anke [Department of Physics, McGill University, 3600 Rue Universite, Montreal, Quebec, H3A 2T8 (Canada)

2008-10-15

195

Theoretical studies of atomic transitions  

NASA Astrophysics Data System (ADS)

The Multiconfiguration Hartree-Fock (MCHF) method with the Breit-Pauli correction for relativistic effects was applied to a number of systems. The fine-structure splitting of the 2p(3) levels of nitrogen was investigated as well as the forbidden (E2 and M1) transitions between these levels. Also of particular interest was the term separation and fine-structure splitting for both the 2s(2)2p(4) and 2s2p(5) configurations of oxygen. Transition probabilities for the forbidden transitions between the levels of 2s(2)2p(4) were predicted as well as those for allowed 2s(2)2p(4) to 2s2p(5) transitions. The fine-structure splitting of the 3p(3) levels of phosphorus was studied and transition probabilities predicted for forbidden transitions between these levels. Both the 2p(3) and the 3p(3) sequences are of astrophysical interest where for light atoms the ratio of intensities of lines is an indicator of the electron density. For the more highly ionized species of these sequencies, the forbidden transitions have been observed in the Tokamak plasmas. In the 3p(3) sequence, tentative assignments were made to the observed lines, assignments to be verified by these calculations.

Fischer, C. F.

196

Transition Probabilities of Gd I  

NASA Astrophysics Data System (ADS)

Rare earth transition probabilities are needed within the astrophysics community to determine rare earth abundances in stellar photospheres. The current work is part an on-going study of rare earth element neutrals. Transition probabilities are determined by combining radiative lifetimes measured using time-resolved laser-induced fluorescence on a slow atom beam with branching fractions measured from high resolution Fourier transform spectra. Neutral rare earth transition probabilities will be helpful in improving abundances in cool stars in which a significant fraction of rare earths are neutral. Transition probabilities are also needed for research and development in the lighting industry. Rare earths have rich spectra containing 100's to 1000's of transitions throughout the visible and near UV. This makes rare earths valuable additives in Metal Halide - High Intensity Discharge (MH-HID) lamps, giving them a pleasing white light with good color rendering. This poster presents the work done on neutral gadolinium. We will report radiative lifetimes for 135 levels and transition probabilities for upwards of 1500 lines of Gd I. The lifetimes are reported to ±5% and the transition probabilities range from 5% for strong lines to 25% for weak lines. This work is supported by the National Science Foundation under grant CTS 0613277 and the National Science Foundation's REU program through NSF Award AST-1004881.

Bilty, Katherine; Lawler, J. E.; Den Hartog, E. A.

2011-01-01

197

TRANSITION FROM SCHOOL TO WORK IN TRANSITION ECONOMIES  

Microsoft Academic Search

This paper explores school-to-work transitions in three new EU Member states, Hungary, Slovenia and Estonia, focusing on the effect of the level of education and social background on the timing of the first significant employment and the match between educational qualifications and occupation among school leavers. So-called cohort effects are a focal point as well, since transition process and outcomes

Irena Kogan; Marge Unt

2005-01-01

198

Demographic transition: A forcing model.  

PubMed

Transition Theory provides the theoretical underpinning for many explanations for past population changes and, more importantly, for many population projections. Our paper proves, through the use of symbolic logic, that Transition Theory does not contain principles strong enough to support population projections. Such projections, consequently, must be based upon their author's intuition rather than a reasoned application of Transition Theory. We follow our proofs with a brief discussion of various ways in which the Theory may be modified. Our emphasis is upon and only upon the logical characters of these modifications. PMID:21274810

Loschky, D J; Wilcox, W C

1974-05-01

199

Holographic approach to phase transitions  

SciTech Connect

We provide a description of phase transitions at finite temperature in strongly coupled field theories using holography. For this purpose, we introduce a general class of gravity duals to superconducting theories that exhibit various types of phase transitions (first or second order with both mean and non-mean field behavior) as parameters in their Lagrangian are changed. Moreover the size and strength of the conductivity coherence peak can also be controlled. Our results suggest that certain parameters in the gravitational dual control the interactions responsible for binding the condensate and the magnitude of its fluctuations close to the transition.

Franco, Sebastian; Garcia-Garcia, Antonio M.; Rodriguez-Gomez, Diego [KITP, University of California, Santa Barbara, CA93106-4030 (United States); CFIF, IST, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal) and Physics Department, Princeton University, Princeton, New Jersey 08544 (United States); Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

2010-02-15

200

Passenger Reactions to Transit Safety Measures.  

National Technical Information Service (NTIS)

Safety and security are important considerations for the transit operator, but few empirical studies exist that measure the effectiveness of measures taken to improve transit safety on either actual crime (or other incident) data or transit passengers per...

1999-01-01

201

Teenage Attitudes and Perceptions Regarding Transit Use.  

National Technical Information Service (NTIS)

A survey of transit agencies across the country was conducted to assess industry experience with promoting transit to teenagers. This survey showed that there were three main promotional program types; educational programs, reduced fares and transit passe...

A. Cain P. Hamer J. Sibley-Perone

2005-01-01

202

Conditions for Creativity at Transit Agencies.  

National Technical Information Service (NTIS)

In 1997, the National Urban Transit Institute at CUTR produced a report entitled 'Lessons Learned in Transit Efficiencies, Revenue Generation, and Cost Reductions.' That report summarized over 175 different methods being used at transit agencies to make a...

J. Volinski

2001-01-01

203

Transitions: From Pediatric to Adult Health Care  

MedlinePLUS

... Businesses & Schools > Transitions Transitions From Pediatric to Adult Health Care Transitioning from teenage years to adulthood can be ... management and make more independent judgments about their health care needs. NDEP has assembled the materials below to ...

204

Transit variations in WASP-3  

NASA Astrophysics Data System (ADS)

The variations in the period and duration of the transits of exoplanets allow us to obtain some of their orbital properties. Here we investigate the variations in the transit parameters of WASP-3 over a period of time that covers more than three years. Apart from providing complementary information on the geometrical configuration of the system, the investigation of transit duration (TDV) can also provide indirect evidence of the presence of additional planets. The WASP-3 system constitutes the first example for which the TDV have been tracked over a long period of time, allowing for the easier detection of secular variations of the orbital parameters. This work shows that the effects of nodal precession are clearly discernible in the TDV of WASP-3, as the theory predicts. We also confirm the presence of strong transit time (TTV) in a shorter time scale but in this case the periodicity of the signal is not so clear.

Cuesta, L.; Teresa Eibe, M.; Ullán, A.; Pérez-Verde, A.; Navas, J.

2013-05-01

205

Stress Relief of Transition Zones.  

National Technical Information Service (NTIS)

This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansio...

J. Woodward D. van Rooyen

1984-01-01

206

Laser Manipulation of Nuclear Transitions.  

National Technical Information Service (NTIS)

The project is focused on theoretical and experimental studies of the quantum coherence effects at the atomic and nuclear transitions in solids. The main results are the following. 1. Electromagnetically Induced Transparency (EIT) and all-optical writing ...

O. Kocharovskaya

2008-01-01

207

Super Bowl and Transit 2012  

Microsoft Academic Search

This session will examine the planning and operation of mass transit bus and ground transportation in the Indianapolis Metro area in support of the 2012 Super Bowl. Focus will be on IndyGo and Indianapolis International Airport service areas.

Annette Darrow; Samantha Cross

2012-01-01

208

Nonradiative Transition Dynamics in Alexandrite.  

National Technical Information Service (NTIS)

The first direct picosecond time resolved measurement of the nonradiative transitions dynamics between the excited 4T2 pump band and the metastable 2E storage level of the trivalent chromium ion in alexandrite is reported. The nonradiative relaxation time...

S. K. Gayen W. B. Wang V. Petricevic R. R. Alfano

1986-01-01

209

Transit and the Polycentric City.  

National Technical Information Service (NTIS)

The report describes the role transit plays in evolving polycentric cities, with clusters of activity centers located at some distance from existing downtown areas. The study shows that the concept is widely used by metropolitan planning agencies in the U...

J. B. Schneider

1981-01-01

210

India's population in transition.  

PubMed

This demographic profile of India addresses fertility, family planning, and economic issues. India is described as a country shifting from economic policies of self-reliance to active involvement in international trade. Wealth has increased, particularly at higher educational levels, yet 25% still live below the official poverty line and almost 66% of Indian women are illiterate. The government program in family planning, which was instituted during the early 1950s, did not change the rate of natural increase, which remained stable at 2.2% over the past 30 years. 1993 marked the first time the growth rate decline to under 2%. The growth rate in 1995 was 1.9%. The total population is expected double in 36 years. Only Nigeria, Pakistan, and Bangladesh had a higher growth rate and higher fertility in 1995. India is geographically diverse (with the northern Himalayan mountain zone, the central alluvial plains, the western desert region, and the southern peninsula with forest, mountains, and plains). There are regional differences in the fertility rates, which range from replacement level in Kerala and Goa to 5.5 children in Uttar Pradesh. Fertility is expected to decline throughout India due to the slower pace of childbearing among women over the age of 35 years, the increase in contraceptive use, and increases in marriage age. Increased educational levels in India and its state variations are related to lower fertility. Literacy campaigns are considered to be effective means of increasing the educational levels of women. Urbanization is not expected to markedly affect fertility levels. Urban population, which is concentrated in a few large cities, remains a small proportion of total population. Greater shifts are evident in the transition from agriculture to other wage labor. Fertility is expected to decline as women's share of labor force activity increases. The major determinant of fertility decline in India is use of family planning, which has improved in access and use during the 1980s. If India is to keep a stable population under 1.6 billion in the future, Indians may have to accept only one child per family. PMID:12290691

Visaria, L; Visaria, P

1995-10-01

211

Chimie douce and phase transitions  

Microsoft Academic Search

New oxides have been prepared in the WO3-MoO3 system, the structure of which can be described by corner-sharing (MO6) octahedra forming structures of hexagonal tungsten bronze-type, ReO3-type and pyrochlore-type. These oxides are metastable phases which transform irreversibly above 400°C into the stable phases. These monotropic, reconstructive and first-order transitions present special features compared with classical phase transitions. Indeed, they are

M. Figlarz; B. Gerand; B. Dumont; A. Delahaye-Vidal; F. Portemer

1991-01-01

212

Geometric Transition versus Cascading Solution  

Microsoft Academic Search

We study Vafa's geometric transition and Klebanov-Strassler solution from various points of view in M-theory. In terms of brane configurations, we show the detailed equivalences between the two models. In some limits, both models have an alternative realization as fourfolds in M-theory with appropriate G-fluxes turned on. We discuss some aspects of the fourfolds including how to see the transition

Keshav Dasgupta; Kyungho Oh; Radu Tatar

2002-01-01

213

The Transition to Adoptive Parenthood  

Microsoft Academic Search

\\u000a The transition to parenthood is generally regarded as a major life event that necessitates change and readjustment on the\\u000a part of individuals and couples in order to negotiate a successful transition (Belsky et al. 1985). Specifically, the dyadic\\u000a (couple) unit must evolve from a two-person to a three-person system; in turn, partners must expand their repertoire of roles\\u000a to include

Abbie E. Goldberg

214

Hurricane Canadian Style: Extratropical Transition  

NSDL National Science Digital Library

This Webcast is based on a presentation delivered by Jim Abraham of MSC at the Winter Weather Course in February 2001. The presentation discusses how, under the right synoptic conditions, hurricanes and tropical storms undergo a transition process to extratropical cyclones as they move into northern latitudes. During the transition process these "hybrid" systems can bring damaging weather conditions to Eastern Canada and the Northeastern States. It uses several case examples to demonstrate the process.

Spangler, Tim

2002-01-01

215

Transition Probabilities of Gd I  

Microsoft Academic Search

Rare earth transition probabilities are needed within the astrophysics community to determine rare earth abundances in stellar photospheres. The current work is part an on-going study of rare earth element neutrals. Transition probabilities are determined by combining radiative lifetimes measured using time-resolved laser-induced fluorescence on a slow atom beam with branching fractions measured from high resolution Fourier transform spectra. Neutral

Katherine Bilty; J. E. Lawler; E. A. Den Hartog

2011-01-01

216

Glass Transitions: Opportunities and Challenges  

Microsoft Academic Search

\\u000a Glass transition is a time-dependent change in the state of a noncrystalline material. It often explains solid–liquid transformations\\u000a in foods and it may control changes in food structure and texture as well as chemical reactions. At temperatures around the\\u000a glass transition, an amorphous solid transforms to a supercooled liquid (rubber) which contributes to changes in molecular\\u000a mobility and flow properties

Yrjö H. Roos; Nattiga Silalai

217

The Dutch energy transition approach  

Microsoft Academic Search

The article describes the Dutch energy transition approach as an example of an industrial policy approach for sustainable\\u000a growth. It is a corporatist approach for innovation, enrolling business in processes of transitional change that should lead\\u000a to a more sustainable energy system. A broad portfolio of options is being supported. A portfolio of options is generated\\u000a in a bottom-up, forward

René Kemp

2010-01-01

218

Boundary layer transition studies  

NASA Astrophysics Data System (ADS)

A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner & Skan similarity solution in the FPG. Application of the APG causes the layer to separate and a highly turbulent and approximately 2D mean flow reattachment occurs downstream. In an effort to gain some physical insight into the flow processes a small impulsive disturbance was introduced at the C(sub p) minimum. The facility is totally automated and phase-averaged data are measured on a point-by-point basis using unprecedently large grids. The evolution of the disturbance has been tracked all the way into the reattachment region and beyond into the fully turbulent boundary layer. At first, the amplitude decays exponentially with streamwise distance in the APG region, where the layer remains attached, i.e. the layer is viscously stable. After separation, the rate of decay slows, and a point of minimum amplitude is reached where the contours of the wave packet exhibit dispersive characteristics. From this point, exponential growth of the amplitude of the disturbance is observed in the detached shear layer, i.e. the dominant instability mechanism is inviscid. A group of large-scale 3D vortex loops emerges in the vicinity of the reattachment. Remarkably, the second loop retains its identify far downstream in the turbulent boundary layer. The results provide a level of detail usually associated with CFD. Substantial modifications were made to the facility for the second study concerning disturbances generated by Suction Holes for laminar flow Control (LFC). The test section incorporates suction through interchangeable porous test surfaces. Detailed studies have been made using isolated holes in the impervious test plate that used to establish the Blasius base flow. The suction is perturbed harmonically and data are averaged on the basis of the phase of the disturbance, for conditions corresponding to strong suction and without suction.

Watmuff, Jonathan H.

1995-02-01

219

Individualized Transition Plans (ITP): A National Perspective.  

ERIC Educational Resources Information Center

Information concerning implementation of Individualized Transition Plans (ITP) was collected from 46 states and analyzed to determine documentation used in transition planning, relationship between the ITP and Individualized Education Programs, age for beginning transition planning, individuals involved in transition planning, and issues addressed…

Repetto, Jeanne B.; And Others

1990-01-01

220

Animated Transitions in Statistical Data Graphics  

Microsoft Academic Search

In this paper we investigate the effectiveness of animated transitions between common statistical data graphics such as bar charts, pie charts, and scatter plots. We extend theoretical models of data graphics to include such transitions, introducing a taxonomy of transition types. We then propose design principles for creating effective transitions and illustrate the application of these principles in DynaVis, a

Jeffrey Heer; George G. Robertson

2007-01-01

221

BUS RAPID TRANSIT: SYNTHESIS OF CASE STUDIES  

Microsoft Academic Search

Bus rapid transit systems have grown in popularity in recent years. Spurred by federal initiatives, the spiraling cost of rail transit, and market realities, a growing number of cities have installed or are planning bus rapid transit (BRT). There is a synthesis of current experience, drawing on ongoing research conducted in a project for the Transit Cooperative Research Program (TCRP).

Herbert S Levinson; Samuel Zimmerman; Jennifer Clinger; James Gast

2003-01-01

222

Family-Directed Transition Planning Guide.  

ERIC Educational Resources Information Center

|This guide to family-directed transition planning is intended to help parents and students with disabilities take leading roles in the process of transition from school to post-school activities. First, a letter to families examines the challenge of change and the transition process. Section 2 examines regulations that affect transition planning,…

Colorado State Dept. of Education, Denver. Div. of Special Education Services.

223

Puckering transitions of pseudoproline residues.  

PubMed

The puckering transitions of pesudoprolines such as oxazolidine and thiazolidine residues (Oxa and Thz dipeptides) with trans and cis prolyl peptide bonds were explored by optimizations along the endocyclic torsion angle chi(1) using quantum-chemical methods in the gas phase and in water. The overall shapes of the potential energy surfaces for Oxa and Thz dipeptides in the gas phase and in water are similar to those for the Pro dipeptide, although there are some differences in relative stabilities of local minima and in barriers to puckering transition. On the whole, the barriers to puckering transition for Oxa and Thz dipeptides are computed to be 0.8-3.2 kcal/mol at the B3LYP/6-311++G(d,p) level in the gas phase and in water, which are lower by 0.5-1.9 kcal/mol than those for the Pro dipeptide. The n --> sigma* interactions for the delocalization of the lone pair of the prolyl amide nitrogen into the antibonding orbitals that are anti to the lone pair appear to play a role in stabilizing the nonplanar puckered transition states over the corresponding planar structures. The calculated barriers indicate that the down-to-up puckering transition can proceed in the orders Pro < Oxa < Thz in the gas phase and Pro approximately Oxa < Thz in water. (c) 2009 Wiley Periodicals, Inc. Biopolymers 91: 444-455, 2009. PMID:19189373

Kang, Young Kee; Park, Hae Sook; Byun, Byung Jin

2009-06-01

224

The Transition to Digital Television  

NSDL National Science Digital Library

The National Cable and Telecommunications Association has prepared this document that summarizes the transition to digital television (DTV) in the U.S. The report, delivered in April 2002, assesses the countrys progress toward greater digital coverage and more widespread DTV programming. After a brief introduction to the technology, the report gives some background on the broadcast industrys efforts to hasten the transition and the challenges that remain. Then the changes in the cable industry are examined, including upgrades and the carriage of digital signals. Lastly, the report covers consumer response -- the sales trends of DTV sets show steady growth for the technology, but the overall transition is not proceeding as quickly as some speculated. This site is also reviewed in the June 21, 2002 NSDL Scout Report for Math, Engineering, and Technology.

Assocation., National C.

2002-01-01

225

Magnetic dipole transitions in the hydrogen molecule  

SciTech Connect

In homonuclear molecules, such as H{sub 2}, the electric dipole transitions are strongly forbidden, and the transitions between rovibrational states are of the electric quadrupole type. We show, however, that magnetic dipole transitions also take place, although they are significantly weaker. We evaluate the probabilities of such transitions between several of the lowest rotational states and compare them with those of the corresponding electric quadrupole transitions.

Pachucki, Krzysztof [Institute of Theoretical Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland); Komasa, Jacek [Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, PL-60-780 Poznan (Poland)

2011-03-15

226

Numerical Simulation of Riblet Controlled Spatial Transition  

Microsoft Academic Search

\\u000a To analyze the fundamental physical mechanism which determines the damping effect of a riblet surface on three-dimensional\\u000a transition several numerical simulations of spatial transition in a flat plate zero-pressure gradient boundary layer above\\u000a a riblet wall are performed in this study. Two types of transition are investigated. The first type of transition, namely\\u000a K-type transition, is induced by a dominant

Stephan Klumpp; Matthias Meinke; Wolfgang Schröder

227

Transit to Work: Workplace travel plans and transit oriented development  

Microsoft Academic Search

Relatively few people commute to work by public transport, though many more could do so. Transit oriented development can bring workplaces closer to frequent public transport and so reduce the need for car commuting. However, changes in the built environment alone may not change commuting choices significantly. Workplace travel plans could be used to leverage a greater shift from solo

David Wake; Catherine Baudains

2005-01-01

228

Context Aware Transit Navigator, Transit IDEA Project No. 65.  

National Technical Information Service (NTIS)

The objective of this project was to create a real-time, context-aware transit navigation system. The system integrates the route-planning and real-time tracking functionality provided by current systems into a single, real-time and context-aware applicat...

J. Eriksson

2013-01-01

229

Family Transitions during the Adolescent Transition: Implications for Parenting.  

ERIC Educational Resources Information Center

Explores how family transitions affect parenting practices in a sample of adolescents. Adolescents from all family types reported significant declines in behavioral control, but not parental responsiveness. Findings suggest that adolescent individuation may overshadow family-type differences during middle adolescence. (Contains 50 references and 3…

Freeman, Harry S.; Newland, Lisa A.

2002-01-01

230

Thailand's Work and Health Transition  

PubMed Central

Thailand has experienced a rapid economic transition from agriculture to industry and services, and from informal to formal employment. It has much less state regulation and worker representation relative to developed nations, who underwent these transitions more slowly and sequentially, decades earlier. We examine the strengthening of Thai government policy and legislation affecting worker’s health, responding to international norms, a new democratic constitution, fear of foreign importer embargos and several fatal workplace disasters. We identify key challenges remaining for Thai policy makers, including legislation enforcement and the measurement of impacts on worker’s mental and physical health.

Kelly, Matthew; Strazdins, Lyndall; Dellora, Tarie; Khamman, Suwanee; Seubsman, Sam-ang; Sleigh, Adrian C

2011-01-01

231

Theoretical Studies of Atomic Transitions  

SciTech Connect

Atomic structure calculations were performed for properties such as energy levels, binding energies, transition probabilities, lifetimes, hyperfine structure, and isotope shifts. Accurate computational procedures were devised so that properties could be predicted even when they could not be obtained from experiment, and to assist in the identification of observed data. The method used was the multiconfiguration Hartree-Fock (MCHF) method, optionally corrected for relativistic effects in the Breit-Pauli approximation. Fully relativistic Dirac-Fock calculations also were performed using the GRASP code A database of energy levels, lifetimes, and transition probabilities was designed and implemented and, at present, includes many results for Be-like to Ar-like.

Charlotte Froese Fischer

2005-07-08

232

Transitional polyps of the colon.  

PubMed

Fourteen polps with the gross appearance of small hyperplastic (metaplastic) polyps, not exceeding five mm in diameter, were removed from the rectum and the sigmoid colon of patients during colonscopy, and from surgical specimens. At light microscopy they were seen to be composed of apparently normal mucosa. In most cases some hyperplastic (metaplastic) and adenomatous polyps were also present. HID-AB stain revealed the polyps to be composed of "transitional" mucosa containing almost exclusively sialomucins, in contrast to normal mucosa, in which sulphomucins predominate. It is suggested that these "transitional" polyps may represent a reservoir of hyperplastic (metaplastic) and adenomatous polps, the different fate depending on different environmental situations. PMID:6180892

Franzin, G; Scarpa, A; Dina, R; Zamboni, G; Fratton, A

1982-09-01

233

Resonance transitions in Zr VIII  

Microsoft Academic Search

The zirconium spectrum produced in a condensed vacuum spark source was recorded on the 3 m normal-incidence spectrograph of the physics department, Lund University (Sweden) from about 250-2550 AA, using aluminium and gold coated gratings. Thirty lines are classified as 4s24p3-4s4p4 transitions, establishing all eight 4s4p4 levels of Zr VIII. New identification of 18 4s24p3-4s24p24d transitions led the authors to

Z A Khan; M S Z Chaghtai; K Rahimullah

1980-01-01

234

Electromagnetic Transitions in 130Ce  

NASA Astrophysics Data System (ADS)

States in 130Ce have been studied using 16O induced reactions on 117Sn and 118Sn targets. Mean lifetimes have been measured for the yrast states up to J? = 22+ using both the Doppler shift attenuation and recoil distance methods. Magnetic dipole transition rates have been deduced from branching ratio measurements within a band based on an isomeric state at 2454 keV. Electric quadrupole transition rates have been determined from mean lifetime measurements for states in the yrast band up to J? = 22+. Both sets of results show an unexpected behaviour.

Nolan, P. J.; Aryaeinejad, R.; Love, D. J. G.; Nelson, A. H.; Smith, P. J.; Todd, D. M.; Twin, P. J.; Garrett, J. D.; Hagemann, G. B.; Herskind, B.

1983-01-01

235

Structural transitions in superionic conductors  

SciTech Connect

The ..cap alpha..arrow-right-left..beta.. phase transition in AgI is studied with use of the new molecular-dynamics technique which allows for a dynamical variation of the shape and size of the cell. In the present model, upon heating of ..beta..-AgI, the iodine ions undergo a hcp..-->..bcc transformation and silver ions become mobile, whereas the reverse transformation is observed on cooling of ..cap alpha..-AgI. The calculated ..cap alpha..arrow-right-left..beta.. transition temperature and structural and dynamical properties are in good agreement with experiments.

Parrinello, M.; Rahman, A.; Vashishta, P.

1983-04-04

236

Waveguide-to-Microstrip Transitions.  

National Technical Information Service (NTIS)

We present the design of a K-band waveguide-to-microstrip transition. This design features a unique tapered coaxial transmission line between the microstrip and the waveguide, resulting in minimum insertion loss and high return loss. From 19.3 to 26.5 GHz...

R. G. Beaudette L. J. Kushner

1989-01-01

237

Dynamics of the chiral transition  

SciTech Connect

Measurements of disoriented chiral condensates (DCC) in heavy ion collisions at RHIC can yield fundamental information on the nature of the QCD phase transition. I review theoretical efforts to understand DCC formation and present work in progress on possible experimental ramifications.

Gavin, S.

1994-07-01

238

Nuclear effects in atomic transitions  

Microsoft Academic Search

Atomic electrons are sensitive to the properties of the nucleus they are bound to, such as nuclear mass, charge distribution, spin, magnetization distribution, or even excited level scheme. These nuclear parameters are reflected in the atomic transition energies. A very precise determination of atomic spectra may thus reveal information about the nucleus, otherwise hardly accessible via nuclear physics experiments. This

Adriana Palffy

2010-01-01

239

Phase transitions in potassium nitrate  

Microsoft Academic Search

It is shown that the heat of transition of the phase change II ? I at 129° on heating KNO3 is dependent on the thermal history of the sample, since it involves two steps, viz., II? III and III? I at 2° interval. During cooling, the latter step is fast and truly reversible, though with a temperature hysteresis. The former

V. V. DESI-IPAVa; M. D. Karkhanavala; U. R. K. Rao

1974-01-01

240

The transition to professional work  

Microsoft Academic Search

A couple of years ago I did an in-depth study of graduates of mathematical sci- ences and asked them about their roles as mathematicians in the workplace. These graduates suggested changes to content, learning methods and structure of uni- versity programs to assist with their transition to the workplace. Kent et al. (1) studied employer needs for mathematics in a

Leigh Wood

241

Supporting Student Veterans in Transition  

ERIC Educational Resources Information Center

|The purpose of this chapter is to offer frameworks and considerations for student affairs professionals seeking to serve the transition needs of the current generation of student veterans. The historical intersections of the military and higher education, particularly with respect to the effects of the draft on students and higher education,…

Rumann, Corey B.; Hamrick, Florence A.

2009-01-01

242

QCD Phase Transitions, Volume 15.  

National Technical Information Service (NTIS)

The title of the workshop, 'The QCD Phase Transitions' in fact happened to be too narrow for its real contents. It would be more accurate to say that it was devoted to different phases of QCD and QCD-related gauge theories, with strong emphasis on discuss...

E. Shuryak T. Schaefer

1999-01-01

243

China's environmental governance in transition  

Microsoft Academic Search

In the face of unprecedented economic and industrial growth levels, China is rapidly developing its system of environmental governance. Coming from a conventional command-and-control approach to environmental policy, which fitted well its centrally planned economy, transitional China is swiftly reforming and diversifying its environmental approaches, instruments, arrangements and legal regulations. This article aims to grasp and assess the direction, extent

Arthur P. J. Mol; Neil T. Carter

2006-01-01

244

Preterm Birth: Transition to Adulthood  

ERIC Educational Resources Information Center

|Preterm birth is associated with greater difficulty with transitions from childhood to adolescence to adulthood. Adolescents and young adults born preterm have higher rates of cerebral palsy, intellectual disability, cognitive impairment, learning disability, executive dysfunction, attention deficit disorder, and social-emotional difficulties…

Allen, Marilee C.; Cristofalo, Elizabeth; Kim, Christina

2010-01-01

245

Preterm Birth: Transition to Adulthood  

ERIC Educational Resources Information Center

Preterm birth is associated with greater difficulty with transitions from childhood to adolescence to adulthood. Adolescents and young adults born preterm have higher rates of cerebral palsy, intellectual disability, cognitive impairment, learning disability, executive dysfunction, attention deficit disorder, and social-emotional difficulties than…

Allen, Marilee C.; Cristofalo, Elizabeth; Kim, Christina

2010-01-01

246

The Transit Agreement in Practice  

Microsoft Academic Search

In late 1997, the EU Commission reviewed its Transit Agreement with Austria, concluding that the ecopoints systems was an effective means to reduce pollution caused by lorries driving through Austria. Yet heavy transport frequencies continued to grow in the sensitive Alpine valleys, the result of the carriers' practice of rerouting transports to get the most out of their quota of

Wilfried Puwein

1998-01-01

247

Dynamics of the LTD Transition  

NASA Astrophysics Data System (ADS)

The laminar flame to turbulent flame to detonation transition in a chemically reactive medium is a highly transient, complex, and dynamic process in which there are continuous qualitative and quantitative changes in the state of the gas. The transition begins with an initially small flame or spark that evolves into a turbulent flame, producing compression and shock waves. The shocks, in turn, may couple with the flame to form unsteady, propagating shock-flame complexes that may transition to a detonation. The complete process is illustrated here with videos made from numerical solutions of the multidimensional, unsteady, chemically reacting, Navier-Stokes equations. The discussion focuses on selected features of the flow, including: formation of a turbulent flame and the nature of the turbulence, shock-wave transitions from single to double Mach reflection, creation of hot spots as the origins of detonations, and comparisons between simulations and experimental data. (This work is done in collaboration with Vadim N. Gamezo, Takanobu Ogawa, David A. Kessler, and Alexei Poludnenko, and is sponsored by ONR, NIOSH, NASA, and NEDO.)

Oran, Elaine S.

2008-11-01

248

Detecting non-transiting exoplanets  

NASA Astrophysics Data System (ADS)

Currently, the most popular way of detecting Extra-solar planets (exoplanets) is via the Transit Method. This method is limited only to planets with orbits such that we observe them transiting their host star. In this work in progress, we propose to identify non-transiting exoplanets in the data currently being collected by the Kepler Space Telescope by detecting orbital phase reflected light variations. Since such variations are due to light from the host star reflected by the planet, we expect this method to work best on closely orbitting large planets. Using the Metropolis-Hastings Monte Carlo and Nested Sampling algorithms, we will determine the presence or absence of nontransiting planets and estimate their orbital parameters such as, orbital inclination, semi-major axis, period, and eccentricity. Our estimates indicate that the development of this technique has the potential to double the number of detectable planets in the Kepler data sets. Here we demonstrate feasibility using portions of data from one of the first transiting planets detected by Kepler, HAT-P-7b.

Placek, Ben; Richards, Zachary; Knuth, Kevin H.

2013-08-01

249

Transition metal sulfide loaded catalyst  

DOEpatents

A zeolite based catalyst for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C.sub.2 + hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

Maroni, Victor A. (Naperville, IL); Iton, Lennox E. (Downers Grove, IL); Pasterczyk, James W. (Westmont, IL); Winterer, Markus (Westmont, IL); Krause, Theodore R. (Lisle, IL)

1994-01-01

250

Resistive Transition of Composite Superconductors.  

National Technical Information Service (NTIS)

Several aspects of the resistive transition of composite NbTi and Nb3Sn superconductors, studied by means of V-I characteristics, are addressed. The shapes of these curves are determined by a large number of parameters. The most essential parameter is the...

J. Boschman

1991-01-01

251

"Mexico in Transition." Curriculum Units.  

ERIC Educational Resources Information Center

|These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de Mexico: Condiciones…

Oregon Univ., Eugene. Foreign Language Resource Center.

252

Transitions in a globalising world  

Microsoft Academic Search

The increasing complexity of our global society means that sustainable development cannot be addressed from a single perspective or scientific discipline. By using the concept of transitions, we examine current and future tensions between welfare, well-being and the environment, and focus on four major issues that are of global importance: two of our key natural resources, water and biodiversity; the

Pim Martens; Jan Rotmans

2005-01-01

253

Suicide and Mass Urban Transit.  

ERIC Educational Resources Information Center

|Presents case consultation in which consultants respond to issues of urban planning for mass transit (subway) system and how to maximize prevention of intentional injury within subway stations. Also asks what type of research study should be used and what type of data collected once system is operating. Case is discussed by Morton M. Silverman…

Berman, Alan L., Ed.

1991-01-01

254

Transition and sickle cell disease.  

PubMed

Sickle cell disease (SCD), the most common genetic disease screened for in the newborn period, occurs in ~1 in 2400 newborns in the general population and 1 in 400 individuals of African descent in the United States. Despite the relative high prevalence and low pediatric mortality rate of SCD when compared with other genetic diseases or chronic diseases in pediatrics, few evidence-based guidelines have been developed to facilitate the transition from pediatrics to an internal medicine or family practice environment. As with any pediatric transition program, common educational, social, and health systems themes exist to prepare for the next phase of health care; however, unique features characterizing the experience of adolescents with SCD must also be addressed. These challenges include, but are not limited to, a higher proportion of SCD adolescents receiving public health insurance when compared with any other pediatric genetic or chronic diseases; the high proportion of overt strokes or silent cerebral infarcts (~30%) affecting cognition; risk of low high school graduation; and a high rate of comorbid disease, including asthma. Young adults with SCD are living longer; consequently, the importance of transitioning from a pediatric primary care provider to adult primary care physician has become a critical step in the health care management plan. We identify how the primary care physicians in tandem with the pediatric specialist can enhance transition interventions for children and adolescents with SCD. PMID:23027174

DeBaun, Michael R; Telfair, Joseph

2012-10-01

255

New Bottomonium Spectroscopy And Transitions  

SciTech Connect

Recent results in bottomonium spectroscopy are reviewed. Topics include the observation of {Upsilon}(nS) {yields} {eta}{Upsilon}(1S) transitions, energy scans above the {Upsilon}(4S) resonance by the BABAR and Belle experiments, and the recent observation of the {eta}{sub b} by the BABAR experiment.

West, Chris; /SLAC

2011-12-01

256

Upper mantle transition region: Eclogite  

Microsoft Academic Search

The upper mantle transition region is usually considered to be peridotite which undergoes a series of phase changes involving spinel and post-spinel assemblages. There are difficulties associated with attempts to explain the 220, 400 and 670 km discontinuities in terms of phase changes in a peridotitic mantle. Moreover, in a differentiated earth there should be large quantities of eclogite in

Don L. Anderson

1979-01-01

257

ISS Update: Transit of Venus  

NASA Video Gallery

ISS Update commentator Brandi Dean interviews Mario Runco, NASA astronaut, about Venus's transit across the sun on June 5, 2012. Questions? Ask us on Twitter @NASA_Johnson and include the hashtag #askStation. For the latest news about the space station, visit http://www.nasa.gov/station.

John Kossum

2012-06-06

258

Stadia Hand Transit with Case  

USGS Multimedia Gallery

This instrument was manufactured by Keuffel & Esser Company, New York & New Jersey, serial #2300. Stadia Hand Transits are made of up a small telescope with cross and stadia hairs and a circular box which serves as either a magnetic compass or clinometer. The company sold these instruments from 1910...

2009-07-22

259

Coastal Transit Options and Policy.  

National Technical Information Service (NTIS)

This project was carried out in two phases. The first phase consisted of a national survey of existing transit services in coastal recreation areas, an analysis of major issues involved in the design and evaluation of such services, and development of a s...

J. H. Banks F. P. Stutz I. Jabbari C. De Cerbo

1983-01-01

260

American Higher Education in Transition  

ERIC Educational Resources Information Center

American higher education is in transition and if there ever was a "golden age" for faculty, it probably is behind us. The best historical data on the composition of faculty is collected annually by the American Mathematical Society. Between 1967 and 2009, the share of full-time faculty with PhDs remained constant at about 90 percent at doctoral…

Ehrenberg, Ronald G.

2011-01-01

261

Alternative Assessment for Transitional Readers.  

ERIC Educational Resources Information Center

|A teacher-developed alternative assessment of reading comprehension was specifically designed for transitional English language learners. Use of the measure with 89 fifth-graders in their first year of English language instruction showed that the students could successfully engage with English texts and provided teachers with useful information…

Beaumont, Carol; de Valenzuela, Julia Scherba; Trumbull, Elise

2002-01-01

262

GLOBAL TRANSITION TO SUSTAINABLE DEVELOPMENT  

EPA Science Inventory

Global transition to sustainable development is possible but many obstacles lie in the way and it will require acts of political will on the part of both the developed and developing nations to become a reality. In this paper, sustainable development is defined as continuous prog...

263

Direct Democracy for Transition Countries  

Microsoft Academic Search

Theoretical arguments and empirical evidence are advanced to bolster the claim that direct political participation via referenda and initiatives constitutes an advanced form of democracy with beneficial effects on Transition Countries. Direct democracy raises trust and honesty and improves social outcomes. Per capita incomes and subjective well-being are raised. Standard arguments against direct democracy (citizens' incompetence and lacking interest, danger

Bruno S. Frey

2003-01-01

264

Leadership Transitions: Keys for Success  

ERIC Educational Resources Information Center

|A leadership transition poses dangers and challenges for both leaders and followers. While each party naturally focuses on the organization's success, time needs to be spent on how the new relationships will develop and mature into effective working relationships. This article discusses the following four areas of interaction between leaders and…

Goodyear, Marilu; Golden, Cynthia

2008-01-01

265

Stress relief of transition zones  

SciTech Connect

This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here concentrated on the identification of an optimal, in-situ stress relief treatment.

Woodward, J.; van Rooyen, D.

1984-01-01

266

"Mexico in Transition." Curriculum Units.  

ERIC Educational Resources Information Center

These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de Mexico: Condiciones…

Oregon Univ., Eugene. Foreign Language Resource Center.

267

Percolation transitions with nonlocal constraint.  

PubMed

We investigate percolation transitions in a nonlocal network model numerically. In this model, each node has an exclusive partner and a link is forbidden between two nodes whose r-neighbors share any exclusive pair. The r-neighbor of a node x is defined as a set of at most N(r) neighbors of x, where N is the total number of nodes. The parameter r controls the strength of a nonlocal effect. The system is found to undergo a percolation transition belonging to the mean-field universality class for r<1/2. On the other hand, for r>1/2, the system undergoes a peculiar phase transition from a nonpercolating phase to a quasicritical phase where the largest cluster size G scales as G~N(?) with ?=0.74(1). In the marginal case with r=1/2, the model displays a percolation transition that does not belong to the mean-field universality class. PMID:23030872

Shim, Pyoung-Seop; Lee, Hyun Keun; Noh, Jae Dong

2012-09-10

268

Online Transit Trip Planner for Small Agencies Using Google Transit: Final Deployment Package.  

National Technical Information Service (NTIS)

Google Transit is a public transportation trip planner that enables travelers to obtain information regarding available transit services between a given origin and given destination. While transit agencies can publish their service information onto Google...

F. Dion G. Lin K. Singa M. Kumar

2011-01-01

269

Animated transitions in statistical data graphics.  

PubMed

In this paper we investigate the effectiveness of animated transitions between common statistical data graphics such as bar charts, pie charts, and scatter plots. We extend theoretical models of data graphics to include such transitions, introducing a taxonomy of transition types. We then propose design principles for creating effective transitions and illustrate the application of these principles in DynaVis, a visualization system featuring animated data graphics. Two controlled experiments were conducted to assess the efficacy of various transition types, finding that animated transitions can significantly improve graphical perception. PMID:17968070

Heer, Jeffrey; Robertson, George

270

The transition to a sustainable society.  

PubMed Central

Transitions in dealing with the root causes of environmental problems are advocated to achieve environmental sustainability. These transformations include (i) a demographic transition, (ii) a technology transition that includes the "green" automobile, (iii) an economic transition to one in which prices reflect full environmental costs, (iv) a transition in social equity, and (v) an institutional transition to different arrangements among governments, businesses, and peoples. Businessmen and environmentalists are urged to work together in the next decade to make the environment a personal issue, to call for government action, to recognize the environmental challenges, and to commit to accountability in order to leave a legacy of hope to the twenty-first century.

Speth, J G

1992-01-01

271

Metals: typical and less typical, transition and inner transition  

Microsoft Academic Search

While most chemists agree on what is a metal and what is a non-metal there is a disagreement with respect to what is a metalloid\\u000a and what is a transition metal. It is believed that this problem can be solved if two new terms are adopted: typical and less\\u000a typical metals. These new terms will also help reconcile the European

Fathi Habashi

2010-01-01

272

Coastal lagoons: “transitional ecosystems” between transitional and coastal waters  

Microsoft Academic Search

The European Water Framework Directive (WFD) establishes a well differentiated typology of water bodies on the basis of scientific\\u000a and biological criteria. For coastal waters, such criteria have long been established, while for transitional waters they\\u000a are still under discussion. One of the difficulties when applying the WFD to coastal lagoons is to include them in only one\\u000a of these

Angel Pérez-Ruzafa; Concepción Marcos; Isabel María Pérez-Ruzafa; María Pérez-Marcos

273

M-shell X-ray production cross-sections for elements with 67 {<=} Z {<=} 92 at incident photon energies E{sub M{sub 1}}  

SciTech Connect

The X-ray production cross-sections for the Mk (k = {xi}, {delta}, {alpha}, {beta}, {zeta}, {gamma}, m{sub 1} and m{sub 2}) groups of X-rays have been evaluated for all the elements with 67 {<=} Z {<=} 92 at incident photon energies ranging E{sub M{sub 1}}Coster-Kronig yields, and the K-shell/L{sub j} (j = 1-3) subshell to the M{sub i} (i = 1-5) subshell vacancy transfer probabilities, based on the independent particle models.

Chauhan, Yogeshwar; Kumar, Anil [University College of Engineering, Punjabi University, Patiala 147002, Punjab (India); Puri, Sanjiv [University College of Engineering, Punjabi University, Patiala 147002, Punjab (India)], E-mail: sanjivpurichd@yahoo.com

2009-07-15

274

Double ionization of atomic cadmium  

SciTech Connect

We have recorded the double photoionization spectrum of atomic Cd at four different photon energies in the range 40-200 eV. The main channel is single ionization and subsequent decay of excited Cd{sup +} states, some involving Coster-Kronig processes, whereas direct double ionization is found to be weak. The decay of the excited Cd{sup +} states shows a strong selectivity, related to the configuration of the final state. Double ionization leading to the Cd{sup 2+} ground state is investigated in some detail and is found to proceed mainly through ionization and decay of 4d correlation satellites. The most prominent autoionization peaks have been identified with the aid of quantum-mechanical calculations.

Linusson, P.; Fritzsche, S.; Eland, J. H. D.; Hedin, L.; Karlsson, L.; Feifel, R. [Department of Physics, Stockholm University, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Department of Physics, P. O. Box 3000, FIN-3004 University of Oulu (Finland); GSI Helmholtzzentrum fuer Schwerionenforschung D-64291 Darmstadt (Germany) and Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ (United Kingdom) and Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

2011-02-15

275

Head-up/head-down transition: measurement of transition times.  

PubMed

A method was developed to measure transition times between a head-up signal and a response given to a head-down display. Various arrangements of motor response (vocal, hand) and HDD images were used. In the first experiment, vocal and manual response times were recorded in a current fighter aircraft mock-up situation. The shortest times were obtained for voice responses. The time elapsed between a HUD signal and the simple response to the HDD was approximately 1600 ms. The time for physical transition where accommodation changes occur was 700 ms. In the second experiment, two types of images were displayed on the HDD: a "positive" contrast (green symbol on black background), and a "negative" contrast (black symbol on green background) in order to compare accommodation to structured and unstructured backgrounds. Perception time was significantly shorter for the "positive" contrast, and transition times were similar to those measured in the first experiment. This method permits the evaluation in a dynamic aeronautical environment of the acquisition and processing of information. Changes in psychological conditions (heavier information processing) and/or physiological conditions (changing accommodation, gaze axis, convergence) can be evaluated in future research. PMID:3964150

Menu, J P

1986-03-01

276

Analysis of Nosetip Boundary Layer Transition Data.  

National Technical Information Service (NTIS)

A critical analysis is presented of the available wind tunnel data simulating nosetip boundary layer transition on reentry vehicles. It is agreed that transition should depend on surface roughness, surface temperature, and surface curvature. The Reynolds ...

M. L. Finson

1976-01-01

277

Survey of Transit and Rail Freight Interaction.  

National Technical Information Service (NTIS)

This study surveyed 59 transit entities in North America to identify the best practices and key factors that contribute to the successful interaction between transit agencies and freight railroads. A total of 47 agencies including commuter rail, heavy rai...

R. Liu

2004-01-01

278

Transition from the Magnetosheath to the Magnetosphere.  

National Technical Information Service (NTIS)

Electron anisotropies, and the relationships between electron density, magnetic field, and average electron energy, are studied in the transition region where the magnetosheath merges with the magnetosphere. The outer part of the transition is found to be...

D. S. Hall M. A. Hapgood D. A. Bryant

1990-01-01

279

Transition-Metal Oxides with Metallic Conductivity.  

National Technical Information Service (NTIS)

Two possible mechanisms for metallic conductivity in transition-metal oxides are discussed: band formation on the transition-meta subbary and band formation via pi bonding orbitals. This permits a general classification of metallic oxides. Two electron-tr...

J. B. Goodenough

1964-01-01

280

Public Transit Research: Management and Planning, 1991.  

National Technical Information Service (NTIS)

Partial contents: Regularity Indices for Evaluating Transit Performance; Subway Reliability and the Odds of Getting There on Time; Determining Transit Drug Test Accuracy; The Multidrug Case; Lessons from the Broome County Distance-Based Fare Demonstration...

N. C. Kassabian A. G. Tobias L. Crayton K. Solomon N. Solomon

1991-01-01

281

Functions and Requirements for the Transition Project  

SciTech Connect

This document describes the functional requirement baseline for the Transition of 100 K Area Facilities Project (Transition Project). This baseline information consists of top-level functions, requirements, concept description, interface description, issues, and enabling assumptions.

YANOCHKO, R.M.

2000-04-24

282

Aspects of the electroweak phase transition.  

National Technical Information Service (NTIS)

The electroweak phase transition is reviewed in light of some recent developments. Emphasis is on the issue whether the transition is first or second order and its possible role in the generation of the baryon asymmetry of the universe.

P. Huet

1992-01-01

283

Economic Evaluation of Transit Bus Design Standards.  

National Technical Information Service (NTIS)

The research in this report investigates the perceptions of ITS standards for the public transit industry. The public transit industry has a rather colorful past in standardization, and this experience is reviewed with an eye toward lessons that might be ...

M. Hickman R. Jeong

2001-01-01

284

Metal-insulator transitions: Orbital control  

NASA Astrophysics Data System (ADS)

On cooling, transition metal oxides often undergo a phase change from an electrically conducting to an insulating state. Now it is shown that the metal-insulator transition temperature of vanadium dioxide thin films can be controlled by applying strain.

Mizokawa, Takashi

2013-10-01

285

Rapid Transit Subways-Maintenance Guidelines.  

National Technical Information Service (NTIS)

The maintenance of an underground rapid transit complex requires considerable labor, equipment, and variety of material. This analysis of the maintenance and engineering data of North American and European transit properties identifies the important techn...

J. Birkmyer

1978-01-01

286

Electronic Transitions of Yttrium Monoxide  

NASA Astrophysics Data System (ADS)

The electronic transition spectrum of yttrium monoxide (YO) in the spectral region between 284nm and 307nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence (LIF) spectroscopy. The YO molecule was produced by reacting laser-ablated yttrium atoms with O_{2} seeded in argon. Twenty transition bands were observed in that region and a few bands were selected for further study using optical-optical double resonance (OODR) spectroscopy. The excited C^{2} ? state has been reached via the intermediate B^{2} ?^{+} state from the ground X^{2} ?^{+} state. The excited sub-states observed so far have ? = 0.5 and 1.5. A least squares fit of the measured rotational lines yielded molecular constants for the newly observed excited states.

Ng, Y. W.; Wang, Na; Clark, Andrew B.; Cheung, A. S.-C.

2013-06-01

287

Ordinary Percolation with Discontinuous Transitions  

NASA Astrophysics Data System (ADS)

We study percolation on hierarchical networks using generating functions and renormalization group techniques. Our exact results show the presence of novel features in these networks including the existence of non-trivial critical points, three distinct regimes in the phase diagram and, most importantly, a discontinuity in the formation of the extensive cluster at a critical point pc<1 . At pc , the order parameter P? describing the probability of any node to be a part of the largest cluster, jumps instantly to a finite value. We present simple examples of small-world networks with various hierarchies of long range bonds, indicating that the presence of discontinuous transitions is generic.[4pt] [1] S. Boettcher, V. Singh, and R.M. Ziff. Ordinary Percolation with Discontinuous Transitions. Arxiv preprint arXiv:1110.4288, (2):25, 2011.

Singh, Vijay; Boettcher, Stefan

2012-02-01

288

Quantum transition-edge detectors  

NASA Astrophysics Data System (ADS)

Small perturbations to systems near critical points of quantum phase transitions can induce drastic changes in the system properties. Here I show that this sensitivity can be exploited for weak-signal detection applications. This is done by relating a widely studied signature of quantum chaos and quantum phase transitions known as the Loschmidt echo to the minimum error probability for a quantum detector and noting that the echo, and therefore the error, can be significantly reduced near a critical point. Three examples, namely, the quantum Ising model, the optical parametric oscillator model, and the Dicke model, are presented to illustrate the concept. For the latter two examples, the detectable perturbation can exhibit a Heisenberg scaling with respect to the number of detectors, even though the detectors are not entangled and no special quantum state preparation is specified.

Tsang, Mankei

2013-08-01

289

Ordinary percolation with discontinuous transitions  

NASA Astrophysics Data System (ADS)

Percolation on a one-dimensional lattice and fractals, such as the Sierpinski gasket, is typically considered to be trivial, because they percolate only at full bond density. By dressing up such lattices with small-world bonds, a novel percolation transition with explosive cluster growth can emerge at a non-trivial critical point. There, the usual order parameter, describing the probability of any node to be part of the largest cluster, jumps instantly to a finite value. Here we provide a simple example in the form of a small-world network consisting of a one-dimensional lattice which, when combined with a hierarchy of long-range bonds, reveals many features of this transition in a mathematically rigorous manner.

Boettcher, Stefan; Singh, Vijay; Ziff, Robert M.

2012-04-01

290

An Assessment of the Demographic Transition in China  

Microsoft Academic Search

Many Chinese scholars hold the view that demographic transition in China has been completed. Some even argue that the country has already entered a “post-demographic transition period.” Inspired by John R. Week’s reformulated perspective on demographic transition, this study examines China’s demographic transition with regard to five aspects: epidemiological transition, fertility transition, age transition, family transition, and urban transition. The

Jianjun Ji

2003-01-01

291

The borderline personality and transitional relatedness.  

PubMed

Borderline patients may be distinguished from patients with personality disorders through the former's use of transitional objects. The transitional relatedness of the borderline patient is generally rigid and maladaptive. By comparison, transitional relatedness, both past and present, is essentially absent in patients with severe character disorders. The borderline patient's capacity for transitional relatedness indicates achievement of a developmental level that has implications for diagnostic classification and psychotherapeutic strategy. PMID:7457637

Arkema, P H

1981-02-01

292

Crumpling and buckling transitions in polymerized membranes  

NASA Astrophysics Data System (ADS)

We consider polymerized non-self-avoiding membranes fluctuating under constrained boundary conditions. Such constraints prevent the membranes from being crumpled at high temperature and introduce a tension. Upon lowering the temperature this tension reduces, and vanishes at a transition temperature below which the membrane assumes a buckled state. Buckling transition points, depending on boundary conditions, arrange on a line which terminates at the crumpling transition. We study the critical properties of these transitions by various field-theoretical techniques.

Guitter, E.; David, F.; Leibler, S.; Peliti, L.

1988-12-01

293

Astrophysical relevance of ? transition energies  

NASA Astrophysics Data System (ADS)

The relevant ? energy range is explicitly identified where additional ? strength must be located to have an impact on astrophysically relevant reactions. It is shown that folding the energy dependences of the transmission coefficients and the level density leads to maximal contributions for ? energies of 2?E??4 unless quantum selection rules allow isolated states to contribute. Under this condition, electric dipole transitions dominate. These findings allow us to more accurately judge the relevance of modifications of the ? strength for astrophysics.

Rauscher, Thomas

2008-09-01

294

Explaining the Neolithic Demographic Transition  

Microsoft Academic Search

Three main questions are raised in this chapter.\\u000a \\u000a 1. The part of the signal of the NDT which is demographically identifiable, based on the proportion of the immature skeletons\\u000a in cemeteries, shows that a baby-boom occurred and, beyond that, with the onset of the change in the economic system, a fertility\\u000a transition towards high values also occurred. What was the

Jean-Pierre Bocquet-Appel

295

Transition Regimes in Valley Airflows  

Microsoft Academic Search

A three-dimensional, non-hydrostatic model was used to examine the dynamical characteristics of morning and evening transition periods in the atmosphere over four idealised valleys. The simulations provided detailed structure over full diurnal cycles of the valley-wind system. An essentially two-dimensional simulation (Case 1) clearly showed valley-side slope flows, driven by pressure gradients and modulated by vertical diffusion and Coriolis effects.

J. G. Li; B. W. Atkinson

1999-01-01

296

Polyamorphic transition in amorphous fullerites  

Microsoft Academic Search

Samples of amorphous fullerites have been prepared by mechanoactivation (grinding in a ball mill), and their structure has been studied using neutron diffraction. It has been found that the amorphous fullerites subjected to high-temperature (600-1700°C) annealing undergo a polyamorphic transition from the molecular glass to the atomic glass, which is accompanied by the disappearance of fullerene halos at small scattering

S. S. Agafonov; V. P. Glazkov; I. F. Kokin; V. A. Somenkov

2010-01-01

297

Polyamorphic transition in amorphous fullerites  

Microsoft Academic Search

Samples of amorphous fullerites have been prepared by mechanoactivation (grinding in a ball mill), and their structure has\\u000a been studied using neutron diffraction. It has been found that the amorphous fullerites subjected to high-temperature (600–1700°C)\\u000a annealing undergo a polyamorphic transition from the molecular glass to the atomic glass, which is accompanied by the disappearance\\u000a of fullerene halos at small scattering

S. S. Agafonov; V. P. Glazkov; I. F. Kokin; V. A. Somenkov

2010-01-01

298

Phase transitions in nuclear matter  

SciTech Connect

The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references.

Glendenning, N.K.

1984-11-01

299

Polymorphous transitions in cocoa butter  

Microsoft Academic Search

Summary  Large experimental evidence was collected on polymorphous transitions of triacyl glycerols (TAG) in cocoa butter by means\\u000a of DSC investigations. The cooling treatment (in conditions close to those of the industrial practice) and the annealing temperature\\u000a significantly affect the overall crystal fraction and the distribution of the various polymorphs. These data allowed a quantitative,\\u000a although purely phenomenological, kinetic parameterization of

D. Fessas; M. Signorelli; A. Schiraldi

2005-01-01

300

Structural Transitions in Superionic Conductors  

Microsoft Academic Search

The alpha&rlarr2;beta phase transition in AgI is studied with use of the new molecular-dynamics technique which allows for a dynamical variation of the shape and size of the cell. In the present model, upon heating of beta-AgI, the iodine ions undergo a hep --> bee transformation and silver ions become mobile, whereas the reverse transformation is observed on cooling of

M. Parrinello; A. Rahman; P. Vashishta

1983-01-01

301

STEM Colorado: Simplified Planetary Transits  

NSDL National Science Digital Library

This applet demonstrates how astronomers measure the properties of extra-solar planets by detecting planetary transits and eclipses. The applet shows a planet in orbit around a star. A graph plots the total brightness of the star as the planet orbits around it. The user can control the star's radius, the star's temperature, the planet's radius, the orbital radius and the albedo. This is part of a larger collection of applets by STEM Colorado focused mostly on topics in astronomy.

Mccray, Richard; Koelemay, Andrew

2008-10-22

302

Financing pharmaceuticals in transition economies.  

PubMed

This paper (a) provides a methodological taxonomy of pricing, financing, reimbursement, and cost containment methodologies for pharmaceuticals; (b) analyzes complex agency relationships and the health versus industrial policy tradeoff; (c) pinpoints financing measures to balance safety and effectiveness of medicines and their affordability by publicly funded systems in transition; and (d) highlights viable options for policy-makers for the financing of pharmaceuticals in transition. Three categories of measures and their implications for pharmaceutical policy cost containing are analyzed: supply-side measures, targeting manufacturers, proxy demand-side measures, targeting physicians and pharmacists, and demand-side measures, targeting patients. In pursuing supply side measures, we explore free pricing for pharmaceuticals, direct price controls, cost-plus and cost pricing, average pricing and international price comparisons, profit control, reference pricing, the introduction of a fourth hurdle, positive and negative lists, and other price control measures. The analysis of proxy-demand measures includes budgets for physicians, generic policies, practice guidelines, monitoring the authorizing behavior of physicians, and disease management schemes. Demand-side measures explore the effectiveness of patient co-payments, the impact of allowing products over-the-counter and health promotion programs. Global policies should operate simultaneously on the supply, the proxy demand, and the demand-side. Policy-making needs to have a continuous long-term planning. The importation of policies into transition economy may require extensive and expensive adaptation, and/or lead to sub-optimal policy outcomes. PMID:10234068

Kanavos, P

1999-06-01

303

Electron scattering from transitional nuclei  

NASA Astrophysics Data System (ADS)

An electron scattering experiment on 188Os, 190Os, 192Os, 194Pt and 196Pt has been performed at momentum transfers q = 0.6 to 3.2 fm-1. Transition charge densities have been determined for the low-lying 2+, 3- and 4+ states. The 2+ densities are well reproduced within the framework of the interacting boson model 2, where we have determined the boson densities ??, ??, ??v and ??. The 4+ transition densities could not be reproduced indicating the need for including a g-boson. The ground and transition charge densities of 188Os, 192Os and 196Pt have been compared with a microscopic calculation. The total binding energies and the intrinsic wave functions have been calculated for different values of ? and ? with the constrained triaxial Hartree-Fock-Bogoliubov method using the finite range interaction D1SA. These energies are interpreted as potential energy surfaces and used in the Bohr hamiltonian in order to obtain the total nuclear wave functions. We obtain very good agreement with experiment. The calculated potential energy surfaces show these nuclei to be ?-soft with a shallow minimum for triaxial deformations and rigid in the ? direction.

Boeglin, W.; Egelhof, P.; Sick, I.; Cavedon, J. M.; Frois, B.; Goutte, D.; Mëot, V.; Leconte, P.; Phan, X. H.; Platchkov, S. K.; Williamson, S.; Girod, M.

1988-02-01

304

CP Symmetry and Phase Transitions  

NASA Astrophysics Data System (ADS)

The analytic behaviour of ?-vacuum energy at ? = 0 and ? = ? in QCD is related to the existence of phase transitions which might involve CP symmetry breaking. The appearance of cusp singularities is a signal of CP symmetry breaking by non-perturbative effects. The only cusp singularities that could arise in the vacuum energy density are due to the presence of Lee-Yang zeros but these singularities are always ? cusp singularities and never ? cusps, which in the case ? = 0 is incompatible with the Vafa-Witten diamagnetic inequality. The argument is very similar to that used in the derivation of Bank-Casher formula. In this case the topological charge condensate is proportional to the density of Lee-Yang zeros at the CP invariant points. The fact that this density is always positive provides a key missing link in the Vafa-Witten proof of parity symmetry conservation in vector-like gauge theories like QCD. However, this property does not exclude the existence of a first phase transition at ? = ? with a ? cusp singularity, or a second order phase transition at ? = 0, which might be very relevant for interpretation of the anomalous behavior of the topological susceptibility in the CP1 sigma model.

Aguado, M.; Asorey, M.

2011-04-01

305

Transition metal surface electronic structure  

NASA Astrophysics Data System (ADS)

In the automotive industry, solid surface effects are encountered in areas such as exhaust gas catalysis and sensing, corrosion, adhesion, friction and wear. Transition metals are involved in all of these types of interfaces. Our surface and interface physics programs are designed to characterize relevant physical phenomena in the atomistic sense. Transition metals are characterized in large part by their d-electron behavior. The localized nature of the d-orbitals has necessitated the formulation of a self-consistent local orbital method in order to compute surface electronic structure. Results for the (100) surfaces on work functions agree well with experiment. We found a surprisingly large density of surface states, i.e., localized to the surface region, on palladium, copper, and silver. One-fifth to one-fourth of the electrons in the surface layer are in surface states on these metals. A prominent surface state band found theoretically on copper has subsequently have been observed by Heimann et al., and Kevan and Shirley via angular photoemission. It is clear that henceforth surface states will have to be considered in the analysis of physical and chemical processes on transition metal surfaces.

Smith, J. R.; Arlinghaus, F. J.; Gay, J. G.

1981-01-01

306

TECHNOLOGY TRANSFER IN THE TRANSIT INDUSTRY  

Microsoft Academic Search

The unprecedented advances taking place in the technology industries (computer, electronics, telecommunications) can benefit the transit industry by enabling safer, cleaner, and more reliable transit vehicles; easier maintenance; better customer service; and faster and more efficient scheduling and operations. Without an effective technology transfer (T2) process, however, the technologies may not reach the proper audience in the transit organization, or

Yuko Nakanishi; Ossama Elrahman

2000-01-01

307

The Transition Experiences of Successful Chinese Immigrants  

ERIC Educational Resources Information Center

This article focused on the transition experiences of 20 successful Chinese immigrants, in particular their transition stories and how they accounted for their success (what facilitated and hindered their transition). An enhanced critical incident method was used for data analysis. Four major success categories emerged: having a positive attitude…

Amundson, Norman E.; Yeung, Thomas; Sun, Iris; Chan, Keith; Cheng, Johnny

2011-01-01

308

TRANSITION WITHOUT TRAGEDY, A COMMUNITY PREPARATION HANDBOOK.  

ERIC Educational Resources Information Center

|SOUTHERN COMMUNITIES ARE IN A PERIOD OF TRANSITION TOWARD AN INTEGRATED SOCIETY. IT IS THE CHOICE OF EVERY COMMUNITY WHETHER OR NOT THIS TRANSITION WILL EVOLVE PEACEFULLY OR WHETHER IT WILL BE RESISTED WITH VIOLENT AND TRAGIC RESULTS. IF THE DECISION FOR A PEACEFUL TRANSITION IS MADE, EXAMPLES OF SUCCESSFUL TECHNIQUES, EXPERIENCES, AND EFFORTS IN…

ROBIN, FLORENCE

309

Lost in Transition? Student Food Consumption  

ERIC Educational Resources Information Center

|Findings from transition studies as well as studies of student food show that the transition from living at home to independent living influences student food consumption and that food consumption might be problematic during this period. Furthermore, both students' enactment of being in transition and the food habits and practices they bring with…

Blichfeldt, Bodil Stilling; Gram, Malene

2013-01-01

310

A Latent Transition Model with Logistic Regression  

ERIC Educational Resources Information Center

|Latent transition models increasingly include covariates that predict prevalence of latent classes at a given time or transition rates among classes over time. In many situations, the covariate of interest may be latent. This paper describes an approach for handling both manifest and latent covariates in a latent transition model. A Bayesian…

Chung, Hwan; Walls, Theodore A.; Park, Yousung

2007-01-01

311

School to Work: Making the Transition.  

ERIC Educational Resources Information Center

|This publication describes the Academy for Educational Development's (AED's) vision and work in school-to-work transition and related areas. School-to-work transition is defined, and components of a successful school-to-work transition system are listed. The National Institute for Work and Learning (NIWL) is currently conducting an extensive…

Academy for Educational Development, Washington, DC. National Inst. for Work and Learning.

312

FOREIGN POLICY MISMANAGEMENT DURING AMERICAN PRESIDENTIAL TRANSITIONS  

Microsoft Academic Search

Despite vast literature on American foreign policy and presidential decision-making, little attention has been given to the problems associated with presidential transitions. The American presidential transition period is accompanied by three limitations that threaten the effectiveness of presidential authority. First, presidential authority is unclear in the ambiguity of the transition period. Second, new administrations struggle to incorporate overlapping initiatives and

Linda Schulte

2010-01-01

313

Research Results from the Student Transitions Project  

ERIC Educational Resources Information Center

This report highlights student transition trends across a four-year period, with K-12 data from 2001/02 - 2004/05 and post-secondary data from 2002/03-2005/06. Reported findings include: (1) There is a consistent trend in immediate entry transition rates, with slightly more than half of all high school graduates making an immediate transition into…

Ministry of Advanced Education and Labour Market Development, 2007

2007-01-01

314

Implementation of Zurich's Transit Priority Program.  

National Technical Information Service (NTIS)

Zurich is famous for the quality of its public transit system and it has one of the highest levels of per capita transit ridership in the world. This is because its transit service is fast, frequent, reliable, and inexpensive, due in large part to its tra...

A. B. Nash R. Sylvia

2001-01-01

315

Kepler Observations of Transiting Hot Compact Objects.  

National Technical Information Service (NTIS)

Kepler photometry has revealed two unusual transiting companions: one orbiting an early A-star and the other orbiting a late B-star. In both cases, the occultation of the companion is deeper than the transit. The occultation and transit with follow-up opt...

D. Koch G. Basri J. F. Rowe S. B. Howell W. J. Borucki

2010-01-01

316

Economic Transition in Central and Eastern Europe  

Microsoft Academic Search

Analysing the key problems facing the transition countries in Central and Eastern Europe, this accessible book describes the legacy of the central planners, the progress achieved so far and the need for further reforms. It documents the outstanding successes and failures, and analyses why certain approaches to transition have worked and others have not. It tests where transition is over

Daniel Gros; Alfred Steinherr

317

Transitional Relatedness and Borderline Personality Disorder  

Microsoft Academic Search

This study examined various aspects of transitional relatedness among individuals diagnosed as borderline or antisocial personality disorder. This study was a follow–up to an earlier report (Cooper, 1983) using the Rorschach Transitional Object Scale, which found only marginal support for Modell’s clinical hypothesis that the borderline personality disorder involves a developmental arrest at the stage of the transitional object. The

Steven H. Cooper; J. Christopher Perry; Lizbeth Hoke; Nancy Richman

1985-01-01

318

Lost in Transition? Student Food Consumption  

ERIC Educational Resources Information Center

Findings from transition studies as well as studies of student food show that the transition from living at home to independent living influences student food consumption and that food consumption might be problematic during this period. Furthermore, both students' enactment of being in transition and the food habits and practices they bring with…

Blichfeldt, Bodil Stilling; Gram, Malene

2013-01-01

319

The glass transition of polymer crystals  

Microsoft Academic Search

The statement: “A solid is a condensed phase at a temperature below its glass transition”, is an operational definition. It leads to the corollary that for crystals to be solid, they must be below their glass transition. In this paper evidence for the usefulness of this definition is presented. It is based on the measurement of the glass transition of

Bernhard Wunderlich

2006-01-01

320

Quantum Phase Transition for {gamma} -Soft Nuclei  

SciTech Connect

We examine a quantum phase transition in {gamma} -soft nuclei, where the O(6) limit is simultaneously a dynamical symmetry of the U(6) group of the interacting boson model and a critical point of a prolate-oblate phase transition. This is the only example of phase transitional behavior that can be described analytically for a finite s,d boson system.

Jolie, J.; Casten, R. F.; von Brentano, P.; Werner, V.

2001-10-15

321

The Transition Experiences of Successful Chinese Immigrants  

ERIC Educational Resources Information Center

|This article focused on the transition experiences of 20 successful Chinese immigrants, in particular their transition stories and how they accounted for their success (what facilitated and hindered their transition). An enhanced critical incident method was used for data analysis. Four major success categories emerged: having a positive attitude…

Amundson, Norman E.; Yeung, Thomas; Sun, Iris; Chan, Keith; Cheng, Johnny

2011-01-01

322

IDEA 1997 Transition Issues. Parent Brief.  

ERIC Educational Resources Information Center

This brief for parents discusses the transition of students with disabilities from the structured environment of school to the post-school world and transition requirements under the Individuals with Disabilities Education Act (IDEA) of 1997. It begins by explaining the importance of transition planning and decision-making and the need for…

National Center on Secondary Education and Transition, Minneapolis, MN.

323

Analysis of abrupt transitions in ecological systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

The occurrence and causes of abrupt transitions, thresholds, or regime shifts between ecosystem states are of great concern and the likelihood of such transitions is increasing for many ecological systems. General understanding of abrupt transitions has been advanced by theory, but hindered by the l...

324

No Wasted Moments: Planning Purposeful Transitions  

ERIC Educational Resources Information Center

|This article focuses on the nature of the "transitional minutes" in "any" music class. When transitional minutes before, during, and after rehearsals and classes are unplanned and left to chance, much viable and valuable teaching time is lost. When transitional minutes are well structured, learning can proceed efficiently. One tends to remember…

Nicolucci, Sandra

2010-01-01

325

Wetting transitions at fluid-fluid interfaces  

Microsoft Academic Search

Using a simple model free energy functional we have shown that the transition from partial to complete wetting which occurs at the alphagamma interface for a binary mixture of phase separated liquids (beta and gamma) in equilibrium with their vapour (alpha) can be a first order surface phase transition, as predicted by Cahn, or a second order surface phase transition.

P. Tarazona; M. M. Telo da Gama; R. Evans

1983-01-01

326

No Wasted Moments: Planning Purposeful Transitions  

ERIC Educational Resources Information Center

This article focuses on the nature of the "transitional minutes" in "any" music class. When transitional minutes before, during, and after rehearsals and classes are unplanned and left to chance, much viable and valuable teaching time is lost. When transitional minutes are well structured, learning can proceed efficiently. One tends to remember…

Nicolucci, Sandra

2010-01-01

327

Scaling Effects in the CSP Phase Transition  

Microsoft Academic Search

Phase transitions in constraint satisfaction problems (CSP's) are the subject ofintense study. We identify an order parameter for random binary CSP's. There isa rapid transition in the probability of a CSP having a solution at a critical valueof this parameter. The order parameter allows different phase transition behaviourto be compared in an uniform manner, for example CSP's generated under differentregimes.

Ian P. Gent; Ewan Macintyre; Patrick Prosser; Toby Walsh

1995-01-01

328

Fingerprints of quantum phase transitions  

NASA Astrophysics Data System (ADS)

Phase transitions that occur at the absolute zero of temperature are driven entirely by quantum fluctuations. When such a transition is continuous, the characteristic length scale for these fluctuations diverges at a quantum critical point (QCP). Although QCPs exist only at zero temperature, they can leave fingerprints on, the finite-temperature properties of a system---effects known as quantum critical scaling. For this reason, QCPs have become prime suspects in the ongoing experimental investigation of strongly correlated systems like heavy fermions and cuprate superconductors. Before considering experimental results, it is important to identify the range in temperature over which quantum criticality can be observed. We have addressed this question by calculating the free energy exactly for two models of QCPs. In both cases we find that quantum critical scaling can persist up to a temperature on the order of the microscopic energy scale of the model; however, when we include irrelevant operators in the Hamiltonian, it is possible for the scaling regime to shrink drastically. We have also used quantum criticality to make specific predictions for the hole-doped copper oxide superconductors. If we assume that both sides of the superconducting dome terminate in a QCP, then the transition temperature Tc and the zero-temperature superfluid density rhos(0) should be related by Tc ? rhos(0) y in the vicinity of each QCP. We predict different values of y on the underdoped and overdoped sides of the phase diagram. The value y = 1/2 agrees with recent experiments on underdoped YBa2Cu3O6+delta; existing data on overdoped materials appear to support our conjecture that y > 1/2. The current understanding of quantum phase transitions relies almost entirely on analogies with classical critical phenomena. While these analogies are adequate in many cases, there are other models for which they certainly do not apply. For instance, Anderson localization in three dimensions features a metal-insulator transition accompanied by a diverging localization length, yet the ground state energy density is analytic at the QCP. We propose that the concept of quantum entanglement is very useful in studying QCPs that have no classical analog. In particular, we show that the von Neumann entropy (which measures ground state entanglement) is non-analytic at the QCP in a number of different models, including Anderson localization in three dimensions.

Kopp, Angela Jean

329

Transitioning Towards a Low-Carbon Hydrogen Economy in the United States: Role of Transition Management  

Microsoft Academic Search

This paper describes the process of transitioning to a low-carbon hydrogen economy in the United States and the role of transition management (TM) in this process. Focusing on the transition process for hydrogen-based energy and transport systems in the United States, especially California, this study outlines the key characteristics of TM that have been employed in managing the transition. Several

Jacqueline C. K. Lam; Peter Hills; Esther C. T. Wong

2012-01-01

330

Energy landscapes for cooperative processes: nearly ideal glass transitions, liquid-liquid transitions and folding transitions.  

PubMed

We describe basic phenomenology in the physics of supercooling liquids at constant volume (most simulations), and at constant pressure (most laboratory experiments) before focusing attention on the exceptional cases that exhibit liquid-liquid phase transitions on constant-pressure cooling. We give evidence for point defects in glasses and liquids near T(g). Models based on defects predict transitions with density gaps in constant-pressure systems. We describe the energy landscape representation of such systems. Water, in these terms, is post-critical, and its nearly ideal glass formation can be related to nucleation-free protein 'funnel-folding'. For nucleated folding of proteins, a pseudo-gap should be present. Experimental methods of distinguishing between alternative folding scenarios are described. PMID:15664891

Angell, C Austen

2005-02-15

331

Explosive percolation transitions in Euclidean space  

NASA Astrophysics Data System (ADS)

Since the explosive percolation transition was discovered in a random graph model in the Achlioptas process, whether the explosive percolation transition is indeed discontinuous or continuous has been controversial. Even though extensive studies have been focused on the mean-field behavior of the type of the explosive percolation transition, only a few studies are carried out in Euclidean space, Here, we show that depending on a parameter we introduce, the explosive percolation transition can be either discontinuous or continuous transition in Euclidean space, and is reduced to be continuous in the mean-field limit, which can be shown using an analytic approach.

Sul Cho, Young; Hwang, Sungmin; Jürgen Herrmann, Hans; Kahng, Byungnam

2013-03-01

332

Protein dynamical transition at 110 K  

PubMed Central

Proteins are known to undergo a dynamical transition at around 200 K but the underlying mechanism, physical origin, and relationship to water are controversial. Here we report an observation of a protein dynamical transition as low as 110 K. This unexpected protein dynamical transition precisely correlated with the cryogenic phase transition of water from a high-density amorphous to a low-density amorphous state. The results suggest that the cryogenic protein dynamical transition might be directly related to the two liquid forms of water proposed at cryogenic temperatures.

Kim, Chae Un; Tate, Mark W.; Gruner, Sol M.

2011-01-01

333

Transit peptide design and plastid import regulation.  

PubMed

Import of most nuclear encoded proteins into plastids is directed by an N-terminal transit peptide. Early studies suggested that transit peptides are interchangeable between precursor proteins. However, emerging evidence shows that different transit peptides contain different motifs specifying their preference for certain plastid types or ages. In this opinion article, we propose a 'multi-selection and multi-order' (M&M) model for transit peptide design, describing each transit peptide as an assembly of motifs for interacting with selected translocon components. These interactions determine the preference of the precursor for a particular plastid type or age. Furthermore, the order of the motifs varies among transit peptides, explaining why no consensus sequences have been identified through linear sequence comparison of all transit peptides as one group. PMID:23688728

Li, Hsou-min; Teng, Yi-Shan

2013-05-18

334

TERMS PHOTOMETRY OF KNOWN TRANSITING EXOPLANETS  

SciTech Connect

The Transit Ephemeris Refinement and Monitoring Survey conducts radial velocity and photometric monitoring of known exoplanets in order to refine planetary orbits and predictions of possible transit times. This effort is primarily directed toward planets not known to transit, but a small sample of our targets consists of known transiting systems. Here we present precision photometry for six WASP (Wide Angle Search for Planets) planets acquired during their transit windows. We perform a Markov Chain Monte Carlo analysis for each planet and combine these data with previous measurements to redetermine the period and ephemerides for these planets. These observations provide recent mid-transit times which are useful for scheduling future observations. Our results improve the ephemerides of WASP-4b, WASP-5b, and WASP-6b and reduce the uncertainties on the mid-transit time for WASP-29b. We also confirm the orbital, stellar, and planetary parameters of all six systems.

Dragomir, Diana; Kane, Stephen R.; Ciardi, David R.; Gelino, Dawn M.; Payne, Alan; Ramirez, Solange V.; Von Braun, Kaspar; Wyatt, Pamela [NASA Exoplanet Science Institute, Caltech, MS 100-22, Pasadena, CA 91125 (United States); Pilyavsky, Genady; Mahadevan, Suvrath; Wright, Jason T. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Zachary Gazak, J. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Rabus, Markus, E-mail: diana@phas.ubc.ca [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile)

2011-10-15

335

Transportation energy management: energy efficiency in transit buildings. [Garages transit  

SciTech Connect

This report identifies three types of projects which help transit managers reduce energy bills: low cost projects, moderate cost projects and high cost projects. Low cost projects have capital expenses of less than $1000 and can be expected to reduce energy bills by 10 to 15% with a payback of less than one year. Examples include setback thermostats, delamping, and replacing lights which burn out with smaller wattage lights. Low cost projects are appropriate for implementation in all transit facilities. Moderate cost projects involve capital expenditures of $1000 to 20,000, and will have paybacks of less than 5 years. They include such measures as installing local light switches, converting to high efficiency lighting, and installing waste oil heaters. The moderate cost projects should be included in any facility expansion or rehabilitation. High cost projects have capital expenses of $20,000 or more. These projects require careful analysis, but they can reduce energy bills dramatically. Examples of high cost projects include lighting dimmer systems, heat recovery equipment, internal circulation and automatic doors, radiant heating, and energy management computers. These projects are excellent candidates for inclusion in UMTA facility construction grants. 17 refs.

Not Available

1984-01-01

336

Chemical Signposts in Transition Disks  

NASA Astrophysics Data System (ADS)

In the era of the Kepler Mission, the detection of numerous multi-planet systems has demonstrated that planet-formation appears to be a rather ubiquitous phenomenon. Such systems are believed to form from nascent protoplanetary disks, whose environment sets the stage for initial planetary chemical composition and evolution. However, disk systems typically vary by orders of magnitude in radiation field, densities and temperatures, and thus complex disk models are necessary to fully understand this unique chemical environment. Further evidence for disks as progenitors to planetary systems comes from Spitzer surveys of young disk systems, which have revealed a class of objects known as ``transition disks''. These systems appear to have inner voids and gaps in the dust opacity, possibly indicative of planet evolution and disk clearing. This physical evolution in the dust disk will significantly impact its chemical nature, and therefore these potentially planet-forming systems in ``transition'' should have unique chemical signatures. We predict one such signature to be an active chemistry at the wall interface where the conditions are such that the disk is both heated and optically thick to the photo-dissociating UV. The net result is a wide variety of gas-phase molecules, appearing in line emission as bright molecular rings far from the central star. This behavior should also reveal a wealth of information about the physical conditions in this actively evolving zone between the inner ``cleared'' disk and the massive outer disk. For this presentation I will discuss the features of our disk chemical model pipeline and select model results of transition disk systems. I will also highlight the exciting future of protoplanetary disk chemistry in the era of ALMA, which will truly revolutionize our understanding of the chemical nature of disks.

Cleeves, I.; Bergin, E. A.; Fogel, J.

2011-05-01

337

Making the transition to automation  

SciTech Connect

By 1995, the Bureau of Reclamation's hydropower plant near Hungry Horse, Montana, will be remotely operated from Grand Coulee dam (about 300 miles away) in Washington State. Automation at Hungry Horse will eliminate the need for four full-time power plant operators. Between now and then, a transition plan that offers employees choices for retraining, transferring, or taking early retirement will smooth the transition in reducing from five operators to one. The transition plan also includes the use of temporary employees to offset risks of reducing staff too soon. When completed in 1953, the Hungry Horse structure was the world's fourth largest and fourth highest concrete dam. The arch-gravity structure has a crest length of 2,115 feet; it is 3,565 feet above sea level. The four turbine-generator units in the powerhouse total 284 MW, and supply approximately 1 billion kilowatt-hours of electricity annually to the federal power grid managed by the Bonneville Power Administration. In 1988, Reclamation began to automate operations at many of its hydro plants, and to establish centralized control points. The control center concept will increase efficiency. It also will coordinate water movements and power supply throughout the West. In the Pacific Northwest, the Grand Coulee and Black Canyon plants are automated control centers. Several Reclamation-owned facilities in the Columbia River Basin, including Hungry Horse, will be connected to these centers via microwave and telephone lines. When automation is complete, constant monitoring by computer will replace hourly manual readings and equipment checks. Computers also are expected to increase water use efficiency by 1 to 2 percent by ensuring operation for maximum turbine efficiency. Unit efficiency curves for various heads will be programmed into the system.

Christenson, D.J. (Hungry Horse Dam, Hungry Horse, MT (United States))

1992-10-01

338

Methods of Bypass Transition Diagnostics  

NASA Astrophysics Data System (ADS)

Bypass laminar-turbulent transition (BLTT) taking place in flows with disturbances of different nature is widely spread in various technical applications. However only during the last decade the intensive investigations of BLTT were begun in reference to needs of turbomachinery thermal power installations and internal flows in technological equipment. On the basis of detailed analysis of literature devoted to BLTT we can confidently say flat the earliest experimental investigations on this problem were started in IET NASU in the beginning of the seventies and their results were broadly used for understanding the BLTT mechanism aspects by a number of researchers.

Epik, E. Ya.; Suprun, T. T.

2002-07-01

339

Radiative transitions in metallic nanoclusters  

NASA Astrophysics Data System (ADS)

In this article, a new theoretical approach to studying light-scattering characteristics of nanosized objects based on the solution to the Thomas-Fermi equation and quasi-classical approximation is considered. It is shown that the distribution of valence electrons in the volume of metallic clusters exhibits a specific structure of “spatial zones.” With the aid of quasi-classical wave functions, expressions for the appropriate dipole moments of the transitions between the ground and excited states are obtained; the behavior of the spectrum of gold clusters depending on their sizes is studied; a comparison with existing experimental data is carried out.

Shalin, A. S.

2008-02-01

340

Collision lasers on atomic transitions  

SciTech Connect

This paper reviews the research of cw collision lasers on transitions of atoms and atomic ions and presents characteristics of systems that are considered to be collision lasers. Literature data on 'relaxation' and 'mixing' of levels by collisions with heavy particles are discussed, with particular attention to the relaxation of metastable levels. The major problems in the development of efficient cw collision lasers are analysed, including difficulties in realising discharges suitable for pumping collision lasers. The possibility of further advances in collision laser development is discussed. (review)

Petrash, G G [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2009-02-28

341

The Amazon basin in transition.  

PubMed

Agricultural expansion and climate variability have become important agents of disturbance in the Amazon basin. Recent studies have demonstrated considerable resilience of Amazonian forests to moderate annual drought, but they also show that interactions between deforestation, fire and drought potentially lead to losses of carbon storage and changes in regional precipitation patterns and river discharge. Although the basin-wide impacts of land use and drought may not yet surpass the magnitude of natural variability of hydrologic and biogeochemical cycles, there are some signs of a transition to a disturbance-dominated regime. These signs include changing energy and water cycles in the southern and eastern portions of the Amazon basin. PMID:22258611

Davidson, Eric A; de Araújo, Alessandro C; Artaxo, Paulo; Balch, Jennifer K; Brown, I Foster; C Bustamante, Mercedes M; Coe, Michael T; DeFries, Ruth S; Keller, Michael; Longo, Marcos; Munger, J William; Schroeder, Wilfrid; Soares-Filho, Britaldo S; Souza, Carlos M; Wofsy, Steven C

2012-01-18

342

Major Transitions in Language Evolution  

NASA Astrophysics Data System (ADS)

Language is the most important evolutionary invention of the last few million years. How human language evolved from animal communication is a challenging question for evolutionary biology. In this paper we use mathematical models to analyze the major transitions in language evolution. We begin by discussing the evolution of coordinated associations between signals and objects in a population. We then analyze word-formation and its relationship to Shannon's noisy coding theorem. Finally, we model the population dynamics of words and the adaptive emergence of syntax.

Plotkin, Joshua B.; Nowak, Martin A.

2001-11-01

343

Phase transitions in layered superconductors  

Microsoft Academic Search

A system of superconducting layers with Josephson coupling J between them is studied. When the in-layer penetration depth lambdae is larger than the spacing d between layers, as in CuO2-based superconductors, there is a single three-dimensional transition temperature Tc. The ratio Tc\\/tau, where tau=phi20\\/4pi2lambdae, is found to vary from ~1\\/8 to ~1, being near 1\\/8 when J\\/Tc is exponentially small.

Baruch Horovitz

1992-01-01

344

Shim for sealing transition pieces  

SciTech Connect

According to one aspect of the invention, a shim for sealing two adjacent turbine transition pieces is disclosed. The shim includes a circumferential member that includes a first lateral flange and a second lateral flange. Further, the first and second lateral flanges each comprise a tab configured to mate to a first surface plane and the first and second lateral flanges are configured to mate to a second surface plane, wherein the first and second surface planes are substantially parallel. In addition, the shim includes a first flange extending substantially perpendicular from the circumferential member.

Lacy, Benjamin Paul (Greer, SC); Demiroglu, Mehmet (Troy, NY); Sarawate, Neelesh Nandkumar (Niskayuna, NY)

2012-07-24

345

Transitions between de Sitter minima  

SciTech Connect

We investigate the cosmological signatures of instantons mediating tunneling between de Sitter minima. For generic potentials the Coleman-de Luccia instanton does not necessarily exist; when it does not, the instanton which contributes to the decay rate is the trivial constant solution, known as the Hawking-Moss instanton. With the aid of a toy model we interpret this solution and describe the resulting cosmology. In neither the Coleman-de Luccia nor Hawking-Moss case can the resulting cosmology be closed. An observation of significant positive curvature would therefore rule out the possibility that our universe arose from any transition from a neighboring minimum in the string-theory landscape.

Batra, Puneet [Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027 (United States); Kleban, Matthew [CCPP Department of Physics, New York University, 4 Washington Place, New York, New York 10003 (United States)

2007-11-15

346

Transitions to alternative energy systems  

SciTech Connect

Transitions to Alertnative Energy Systems attempts to understand, through a series of case studies, the roles of technical and social entrepreneurs, policy-makers, and other change-agents in the development of alternative energy technologies (solar, wind, geothermal, wood, peat, and heat pumps). The book indicates, the introduction of a new technology requires more than simply showing technical and economic feasibility to guarantee success. Also of major importance are sociopolitical elements, including public perceptions of a new technology (as affected by marketing strategies), the influence of monopolistic industries (e.g., through political lobbying efforts), the inclinations of politically powerful individuals and institutions, and the degree of change required from traditional systems.

Baumgartner, T.; Burns, T.R.

1984-01-01

347

Elaborating transition interface sampling methods  

SciTech Connect

We review two recently developed efficient methods for calculating rate constants of processes dominated by rare events in high-dimensional complex systems. The first is transition interface sampling (TIS), based on the measurement of effective fluxes through hypersurfaces in phase space. TIS improves efficiency with respect to standard transition path sampling (TPS) rate constant techniques, because it allows a variable path length and is less sensitive to recrossings. The second method is the partial path version of TIS. Developed for diffusive processes, it exploits the loss of long time correlation. We discuss the relation between the new techniques and the standard reactive flux methods in detail. Path sampling algorithms can suffer from ergodicity problems, and we introduce several new techniques to alleviate these problems, notably path swapping, stochastic configurational bias Monte Carlo shooting moves and order-parameter free path sampling. In addition, we give algorithms to calculate other interesting properties from path ensembles besides rate constants, such as activation energies and reaction mechanisms.

Erp, Titus S. van [Laboratoire de Physique/Centre Europeen de Calcul Atomique et Moleculaire, Ecole Normale Superieure de Lyon, 46 allee d'Italie, 69364 Lyon Cedex 07 (France)]. E-mail: tsvanerp@cecam.fr; Bolhuis, Peter G. [Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam (Netherlands)]. E-mail: bolhuis@science.uva.nl

2005-05-01

348

Plateau-Plateau transitions in bilayer graphene  

NASA Astrophysics Data System (ADS)

In the framework of the scaling theory of the integer quantum Hall effect, the plateau-plateau transition is interpreted as a quantum phase transition with an associated universal critical exponent. We have investigated[1] the integer quantum hall effect in a graphene sample with Hall-bar geometry doped away from the Dirac point at magnetic fields up to 28T. The experimental characterization of the quantum Hall plateau-plateau quantum phase transitions relies on the behaviour of the system as a function of the temperature for magnetic fields sufficiently close to a transition point. We will show the plateau-plateau transition in a bilayer graphene sample and we will compare it with previous measurements in graphene and other 2DEG in order to study the universality of the critical exponent of the transition. [1] M. Amado, E. Diez, F. Rossella, V. Bellani, D. Lopez-Romero D. K. Maude, J. Phys.: Condens. Matter 24 (2012) 305302

Sanchez-Fabres Cobaleda, Cayetano; Diez, Enrique

2013-03-01

349

Kepler Systems That Show Multiple Transiting Objects  

NASA Astrophysics Data System (ADS)

Exoplanetary systems that have multiple transiting planets provide unique and important insight into the formation, evolution, and dynamics of exoplanetary systems. Kepler has announced the discovery of a confirmed planetary system with multiple transiting planets (Kepler 9, Holman et al. 2010) as well as several candidate planetary systems that show multiple transiting objects (Steffen et al. 2010). Kepler 9 shows deviations from a constant period due to the ongoing dynamical interactions between the confirmed planets. From these transit timing variations (TTV) one can measure the planetary masses from the photometric data alone. The presence of several systems with multiple transiting candidates from the first quarter of data indicate that Kepler should continue to find systems with multiple transiting planets. Such systems will provide important, general information about the histories of planetary systems.

Steffen, Jason H.; Fabrycky, D. C.; Ford, E. B.; Holman, M. J.; Lissauer, J. J.; Ragozzine, D.; Welsh, W. F.; Kepler Science Team

2011-01-01

350

More holographic Berezinskii-Kosterlitz-Thouless transitions  

SciTech Connect

We find two systems via holography that exhibit quantum Berezinskii-Kosterlitz-Thouless (BKT) phase transitions. The first is the ABJM theory with flavor and the second is a flavored (1, 1) little string theory. In each case the transition occurs at nonzero density and magnetic field. The BKT transition in the little string theory is the first example of a quantum BKT transition in (3+1) dimensions. As in the 'original' holographic BKT transition in the D3/D5 system, the exponential scaling is destroyed at any nonzero temperature and the transition becomes second order. Along the way we construct holographic renormalization for probe branes in the ABJM theory and propose a scheme for the little string theory. Finally, we obtain the embeddings and (half of) the meson spectrum in the ABJM theory with massive flavor.

Jensen, Kristan [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

2010-08-15

351

M1 transitions between superdeformed states in ?  

NASA Astrophysics Data System (ADS)

Using a triaxial-particle-rotor model, the quadrupole and dipole transition energies, kinematic and dynamic moments of inertia, electromagnetic transition probabilities and the relative intensity of the E2 0954-3899/22/9/007/img2-transitions are calculated for superdeformed bands in 0954-3899/22/9/007/img3. A strong perturbation effect of rotation on transition energies and M1 and E2 transitions of superdeformed states is investigated. The total M1 transitions, enhanced by internal conversion, are expected to compete strongly with the E2 0954-3899/22/9/007/img2-ray at low spins in the superdeformed 0954-3899/22/9/007/img3 nucleus.

Xing, Zheng; Chen, Xingqu; Wang, Xiaochun

1996-09-01

352

Theory of the L-H transition  

SciTech Connect

The theory of the L-H transition in tokamaks is discussed. A transport bifurcation model is presented, which predicts reasonably well several properties of the L-H transition in the DIII-D tokamak, including the evolution in time of the density and temperature profiles. A bifurcation in the radial transport occurs because of a nonlinear feedback mechanism involving the radial electric field. A spontaneous transition is predicted when certain conditions are met; no trigger mechanism is necessary. The predicted profile evolution in H-mode can include a transition to VH-mode, with its characteristically wider transport barrier at the plasma edge. Trigger mechanisms are discussed, as well as the idea of considering the L-H transition as a phase transition.

Hinton, F.L.

1994-09-01

353

A Latent Transition Model With Logistic Regression  

Microsoft Academic Search

Latent transition models increasingly include covariates that predict prevalence of latent classes at a given time or transition\\u000a rates among classes over time. In many situations, the covariate of interest may be latent. This paper describes an approach\\u000a for handling both manifest and latent covariates in a latent transition model. A Bayesian approach via Markov chain Monte\\u000a Carlo (MCMC) is

Hwan Chung; Theodore A. Walls

2007-01-01

354

General analysis of the chiral phase transition  

SciTech Connect

The universality classes applicable to the chiral phase transition are studied. The epsilon-expansion predicts that the chiral transition should always be of first order for three or more flavors. If fluctuations with topological charge evaporate at temperatures well below the chiral transition point, a new phase of hadronic matter could occur, one in which there would be massive violations of isospin. 20 refs., 5 figs.

Pisarski, R.D.

1985-06-01

355

Phase transition in a super superspin glass  

NASA Astrophysics Data System (ADS)

We here confirm the occurrence of spin glass phase transition and extract estimates of associated critical exponents of a highly monodisperse and densely compacted system of bare maghemite nanoparticles. This system has earlier been found to behave like an archetypal spin glass, with, e.g., a sharp transition from paramagnetic to non-equilibrium behavior, suggesting that this system undergoes a spin glass phase transition at a relatively high temperature, Tg ? 140 K.

Mathieu, R.; De Toro, J. A.; Salazar, D.; Lee, S. S.; Cheong, J. L.; Nordblad, P.

2013-06-01

356

Improved parameters for extrasolar transiting planets  

Microsoft Academic Search

We present refined values for the physical parameters of transiting\\u000aexoplanets, based on a self-consistent and uniform analysis of transit light\\u000acurves and the observable properties of the host stars. Previously it has been\\u000adifficult to interpret the ensemble properties of transiting exoplanets,\\u000abecause of the widely different methodologies that have been applied in\\u000aindividual cases. Furthermore, previous studies often

Guillermo Torres; Joshua N. Winn; Matthew J. Holman

2008-01-01

357

Climate reversals and the transition to agriculture  

Microsoft Academic Search

The transition to agriculture is generally acknowledged to be the economic foundation for population growth over the last\\u000a 10,000 years and for modern civilization itself. Dates for pristine transitions to agriculture have become a key input into\\u000a empirical work on economic growth over the very long run. We propose a model of the transition in which population and technology\\u000a respond endogenously

Gregory K. Dow; Clyde G. Reed; Nancy Olewiler

2009-01-01

358

Cancer as a dynamical phase transition  

PubMed Central

This paper discusses the properties of cancer cells from a new perspective based on an analogy with phase transitions in physical systems. Similarities in terms of instabilities and attractor states are outlined and differences discussed. While physical phase transitions typically occur at or near thermodynamic equilibrium, a normal-to-cancer (NTC) transition is a dynamical non-equilibrium phenomenon, which depends on both metabolic energy supply and local physiological conditions. A number of implications for preventative and therapeutic strategies are outlined.

2011-01-01

359

Expert Hypersonic Roughness Induced Transition Experiment  

NASA Astrophysics Data System (ADS)

The development of an in-flight hypersonic roughness- induced transition experiment, based on transition criteria and wind-tunnel validations, is presented. Further elements about the flight payload and instrumentation mechanical design are discussed. This applied study is further supported by a fundamental flat plate study dedicated to the preparation of post-flight analysis phase and more generally to a better understanding of the roughness-induced transition physical process.

Tirtey, S. C.; Thoemel, J.; Chazot, O.

2009-01-01

360

Continuous and discontinuous metal-insulator transitions  

Microsoft Academic Search

In non-crystalline systems a continuous metal-insulator transition of Andersontype is frequently observed when the Fermi energy moves through a mobility edge. In crystalline systems, on the other hand, the activation energy for conduction should change discontinuously at the transition. The aim of this paper is to enquire under what conditions a discontinuous transition can occur in non-crystalline systems. It clearly

N. F. Mott

1978-01-01

361

A search for transit timing variation  

NASA Astrophysics Data System (ADS)

Photometric follow-ups of transiting exoplanets (TEPs) may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. In 2009 we launched an international observing campaign, the aim of which is to detect and characterise signals of transit timing variation (TTV) in selected TEPs. The programme is realised by collecting data from 0.6-2.2-m telescopes spread worldwide at different longitudes. We present our observing strategy and summarise first results for WASP-3b with evidence for a 15 Earth-mass perturber in an outer 2:1 orbital resonance.

Maciejewski, G.; Neuhäuser, R.; Raetz, St.; Errmann, R.; Kramm, U.; Schmidt, T. O. B.

2011-02-01

362

Dynamics of stimulated L --> H transitions  

NASA Astrophysics Data System (ADS)

We report on model studies of stimulated L --> H transitions [K. Miki et al., Phys. Rev. Lett. 110, 195002 (2013)]. These studies use a reduced mesoscale model. Model studies reveal that L --> H transition can be triggered by particle injection into a subcritical state (i.e., Ptransition. For low ambient heating, strong injection is predicted to trigger a transient turbulence collapse. Repetitive injection at a period less than the lifetime of the collapsed state can thus maintain the turbulence collapse and so sustain a driven H-mode-like state. The total number of particles required to induce a transition by either injection or gas puffing is estimated. Results indicate that the total number of injected particles required is much smaller than that required for a transition by gas puffing. We thus show that internal injection is more efficient than gas puffing of comparable strength. We also observe that zonal flows do not play a critical role in stimulated transitions. For spontaneous transitions, the spike of the Reynolds work of turbulence on the zonal flow precedes the spike in the mean electric field shear. In contrast, we show that the two are coincident for stimulated transitions, suggesting that there is no causal link between zonal and mean flows for stimulated transitions.

Miki, K.; Diamond, P. H.; Hahn, S.-H.; Xiao, W. W.; Gürcan, Ö. D.; Tynan, G. R.

2013-08-01

363

Transitions between spatiotemporal patterns in cell culture  

NASA Astrophysics Data System (ADS)

Cardiac monolayers undergo transitions between different spatiotemporal states as experimental conditions are varied. Monolayers display periodic target pattern waves, stable spiral waves, spirals that spontaneously initiate and terminate, multiple interacting wavefronts, and quiescence. Transitions between these spatiotemporal states are observed during washout of beta-glycyrrhetinic acid, a pharmacological agent that reduces cell-cell coupling. Simple excitable media models undergo the same transitions as local connectivity is continuously varied. Similar mechanisms may be responsible for transitions between healthy and unhealthy rhythms in whole hearts.

Bub, Gil

2005-03-01

364

When is the Deconfinement Phase Transition Universal?  

NASA Astrophysics Data System (ADS)

Pure Yang-Mills theory has a finite-temperature phase transition, separating the confined and deconfined bulk phases. Svetitsky and Yaffe conjectured that if this phase transition is of second order, it belongs to the universality class of transitions for particular scalar field theories in one lower dimension. We examine Yang-Mills theory with the symplectic gauge groups Sp(N). We find new evidence supporting the Svetitsky-Yaffe conjecture and make our own conjecture as to which gauge theories have a universal second order deconfinement phase transition.

Holland, K.; Pepe, M.; Wiese, U.-J.

2004-04-01

365

Negative refraction using Raman transitions and chirality  

SciTech Connect

We present a scheme that achieves negative refraction with low absorption in far-off resonant atomic systems. The scheme utilizes Raman resonances and does not require the simultaneous presence of an electric-dipole transition and a magnetic-dipole transition near the same wavelength. We show that two interfering Raman tran-sitions coupled to a magnetic-dipole transition can achieve a negative index of refraction with low absorption through magnetoelectric cross-coupling. We confirm the validity of the analytical results with exact numerical simulations of the density matrix. We also discuss possible experimental implementations of the scheme in rare-earth metal atomic systems.

Sikes, D. E.; Yavuz, D. D. [Department of Physics, 1150 University Avenue, University of Wisconsin at Madison, Madison, Wisconsin 53706 (United States)

2011-11-15

366

Transitions between patterns in thermal convection  

SciTech Connect

We present experimental studies of the transitions between conduction, hexagons, and rolls in non-Boussinesq convection of gaseous CO{sub 2} in a cylindrical cell of radius-to-height ratio 86. Except for the transition from conduction to hexagons, transitions occur when the two states involved have nearly the same value of a generalized potential rather than at the stability limits. Conduction gives way to hexagons via the propagation of a front connecting the two states, while the transitions between hexagons and rolls are facilitated at the cell walls which appear to nucleate the minority state.

Bodenschatz, E.; de Bruyn, J.R.; Ahlers, G.; Cannell, D.S. (Department of Physics and Center for Nonlinear Science, University of California, Santa Barbara, Santa Barbara, California (USA) Memorial University of Newfoundland, St. John's, Newfoundland (Canada))

1991-11-25

367

The multiuniverse transition in superfluid 3He  

NASA Astrophysics Data System (ADS)

The symmetry-breaking phase transitions of the universe and of superfluid 3He may lead to the formation of different states with different order parameters. In both cases the energy potential below the transition temperature has a complicated multidimensional profile with many local minima and saddle points, which correspond to different states. Consequently, not only topological defects, but also islands of different metastable states can be created. Using 3He we can analyse the properties and experimental consequences of such transitions and, in particular, the first-order phase transition between the two low symmetry states.

Bunkov, Yury

2013-10-01

368

Optimal Flexibility for Conformational Transitions in Macromolecules  

NASA Astrophysics Data System (ADS)

Conformational transitions in macromolecular complexes often involve the reorientation of leverlike structures. Using a simple theoretical model, we show that the rate of such transitions is drastically enhanced if the lever is bendable, e.g., at a localized hinge. Surprisingly, the transition is fastest with an intermediate flexibility of the hinge. In this intermediate regime, the transition rate is also least sensitive to the amount of “cargo” attached to the lever arm, which could be exploited by molecular motors. To explain this effect, we generalize the Kramers-Langer theory for multidimensional barrier crossing to configuration-dependent mobility matrices.

Neher, Richard A.; Möbius, Wolfram; Frey, Erwin; Gerland, Ulrich

2007-10-01

369

Nonadiabatic transitions in electrostatically trapped ammonia molecules  

SciTech Connect

Nonadiabatic transitions are known to be major loss channels for atoms in magnetic traps but have thus far not been experimentally reported upon for trapped molecules. We have observed and quantified losses due to nonadiabatic transitions for three isotopologues of ammonia in electrostatic traps by comparing the trapping times in traps with a zero and a nonzero electric field at the center. Nonadiabatic transitions are seen to dominate the overall loss rate even for the present samples that are at relatively high temperatures of 30 mK. It is anticipated that losses due to nonadiabatic transitions in electric fields are omnipresent in ongoing experiments on cold molecules.

Kirste, Moritz; Schnell, Melanie; Meijer, Gerard [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany); Sartakov, Boris G. [General Physics Institute, RAS, Vavilov Street 38, 119991 Moscow (Russian Federation)

2009-05-15

370

Transition probability studies in 175Au  

NASA Astrophysics Data System (ADS)

Transition probabilities have been measured between the low-lying yrast states in 175Au by employing the recoil distance Doppler-shift method combined with the selective recoil-decay tagging technique. Reduced transition probabilities and magnitudes of transition quadrupole moments have been extracted from measured lifetimes allowing dramatic changes in nuclear structure within a low excitation-energy range to probed. The transition quadrupole moment data are discussed in terms of available systematics as a function of atomic number and aligned angular momentum.

Grahn, T.; Watkins, H.; Joss, D. T.; Page, R. D.; Carroll, R. J.; Dewald, A.; Greenlees, P. T.; Hackstein, M.; Herzberg, R.-D.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Köll, Th; Krücken, R.; Labiche, M.; Leino, M.; Lumley, N.; Maierbeck, P.; Nyman, M.; Nieminen, P.; O'Donnell, D.; Ollier, J.; Pakarinen, J.; Peura, P.; Pissulla, Th; Rahkila, P.; Revill, J. P.; Rother, W.; Ruotsalainen, P.; Rigby, S. V.; Sarén, J.; Sapple, P. J.; Scheck, M.; Scholey, C.; Simpson, J.; Sorri, J.; Uusitalo, J.; Venhart, M.

2013-03-01

371

The multiuniverse transition in superfluid (3)He.  

PubMed

The symmetry-breaking phase transitions of the universe and of superfluid (3)He may lead to the formation of different states with different order parameters. In both cases the energy potential below the transition temperature has a complicated multidimensional profile with many local minima and saddle points, which correspond to different states. Consequently, not only topological defects, but also islands of different metastable states can be created. Using (3)He we can analyse the properties and experimental consequences of such transitions and, in particular, the first-order phase transition between the two low symmetry states. PMID:24026020

Bunkov, Yury

2013-09-11

372

The Coastal Transition Zone Program  

NASA Astrophysics Data System (ADS)

The Coastal Transition Zone (CTZ) Program, sponsored by the Office of Naval Research (Coastal Sciences and Oceanic Biology programs), is designed to investigate the cold tongues ("filaments") often observed in satellite sea surface temperature images of the waters off the west coast of North America. The cold filaments are not unique to this region, since similar features have also been observed along other coasts around the world, including those near Portugal and southwestern Africa. The discovery of these features is an excellent example of the power of satellite observations, because although the filaments are quite prominent in the satellite images, years of regular shipboard observations did not reveal them. On the other hand, the study of cold tongues also illustrates the necessity of on-site observations, because the nature, structure, causes, and effects of filaments cannot be determined from the satellite observations alone.

The Coastal Transition Zone Group

373

The Coastal Transition Zone Program  

NASA Astrophysics Data System (ADS)

The Coastal Transition Zone (CTZ) Program, sponsored by the Office of Naval Research (Coastal Sciences and Oceanic Biology programs), is designed to investigate the cold tongues (“filaments”) often observed in satellite sea surface temperature images of the waters off the west coast of North America. The cold filaments are not unique to this region, since similar features have also been observed along other coasts around the world, including those near Portugal and southwestern Africa. The discovery of these features is an excellent example of the power of satellite observations, because although the filaments are quite prominent in the satellite images, years of regular shipboard observations did not reveal them. On the other hand, the study of cold tongues also illustrates the necessity of on-site observations, because the nature, structure, causes, and effects of filaments cannot be determined from the satellite observations alone.

Coastal Transition Zone Group

374

Kepler-47 transits (Orosz+, 2012)  

NASA Astrophysics Data System (ADS)

We report the detection of Kepler-47, a system consisting of two planets orbiting around an eclipsing pair of stars. The inner and outer planets have radii 3.0 and 4.6 times that of Earth, respectively. The binary star consists of a Sun-like star and a companion roughly one-third its size, orbiting each other every 7.45-days. With an orbital period of 49.5-days, 18 transits of the inner planet have been observed, allowing a detailed characterization of its orbit and those of the stars. The outer planet's orbital period is 303.2-days, and although the planet is not Earth-like, it resides within the classical "habitable zone", where liquid water could exist on an Earth-like planet. With its two known planets, Kepler-47 establishes that close binary stars can host complete planetary systems. (5 data files).

Orosz, J. A.; Welsh, W. F.; Carter, J. A.; Fabrycky, D. C.; Cochran, W. D.; Endl, M.; Ford, E. B.; Haghighipour, N.; MacQueen, P.; Mazeh, T.; Sanchis-Ojeda, R.; Short, D. R.; Torres, G.; Agol, E.; Buchhave, L. A.; Doyle, L. R.; Isaacson, H.; Lissauer, J. J.; Marcy, G. W.; Shporer, A.; Windmiller, G.; Barclay, T.; Boss, A. P.; Clarke, B. D.; Fortney, J.; Geary, J. C.; Holman, M. J.; Huber, D.; Jenkins, J. M.; Kinemuchi, K.; Kruse, E.; Ragozzine, D.; Sasselov, D.; Still, M.; Tenenbaum, P.; Uddin, K.; Winn, J. N.; Koch, D. G.; Borucki, W. J.

2012-11-01

375

Synthesis of transition metal carbonitrides  

DOEpatents

Transition metal carbonitrides (in particular, titanium carbonitride, TiC.sub.0.5 N.sub.0.5) are synthesized by a self-propagating reaction between the metal (e.g., titanium) and carbon in a nitrogen atmosphere. Complete conversion to the carbonitride phase is achieved with the addition of TiN as diluent and with a nitrogen pressure .gtoreq.0.6 MPa. Thermodynamic phase-stability calculations and experimental characterizations of quenched samples provided revealed that the mechanism of formation of the carbonitride is a two-step process. The first step involves the formation of the nonstoichiometric carbide, TiC.sub.0.5, and is followed by the formation of the product by the incorporation of nitrogen in the defect-structure carbide.

Munir, Zuhair A. R. (Davis, CA); Eslamloo-Grami, Maryam (Davis, CA)

1994-01-01

376

[Pharmacologic treatments of transit disorders].  

PubMed

The gastrointestinal transit can be disturbed in different situations by increased or decreased motility patterns. Pharmacological treatment of gastrointestinal motility disorders is intended to inhibit or stimulate motility. Prokinetic agents as metoclopramide, domperidone, erythromycin or tegaserod are used in clinical settings. We discuss their use in functional dyspepsia and gastroparesis. Management of chronic constipation consists of increasing fluid and dietary fiber intake and increasing physical activity. Fiber, lubricants, osmotic and stimulative laxatives increase stool frequency and improve symptoms of constipation. Treatment of irritable bowel syndrome (IBS) should focuses on the specific gastrointestinal complaints. In constipation predominant IBS fiber and isoosmotic laxatives are used first line. Tegaserod has an advantage over placebo in constipation-predominant IBS. Pain can be treated with antispasmodic agents and tricyclic antidepressants in low doses. The diarrhea-predominant IBS responds well to a loperamide treatment. PMID:17663210

Manz, M; Meier, R

2007-04-01

377

Phase transitions in experimental systems  

NASA Astrophysics Data System (ADS)

Scaling functions of the support and of the measure have been used to characterize the scaling behavior of a dynamical system. While scaling functions for the scaling of the measure, ƒ;(?), have been calculated for a number of experimental systems, examples of scaling functions ?(?) for the scaling of the support are difficult to obtain. In this contribution, we report on a phase-transition-like effect of an experimental p-doped germanium semiconductor sample. It is found that the results obtained from the dynamical scaling function agree with those obtained by Horita et al. from model maps, indicating that scaling functions for the scaling of the support are a powerful method of characterizing experimental dynamical systems.

Stoop, Ruedi; Peinke, Joachim; Parisi, Jürgen

1991-07-01

378

Picocyanobacteria in Adriatic transitional environments  

NASA Astrophysics Data System (ADS)

In the marine realm picoplanktonic cyanobacteria (PC) show a broad distribution from the surface ocean to the offshore and coastal waters of semi-enclosed seas and, because of their photoheterotrophy, they are responsible for a substantial fraction of both primary production and organic matter degradation/utilization. In the present study, we investigated PC distribution related to some physical chemical parameters (temperature, salinity and dissolved oxygen), in the most productive periods of the year, spring and fall, at 37 stations located in seven transitional systems all along the Italian coast of the Adriatic Sea: Grado and Marano, Venezia, Pialassa Baiona, Margherita di Savoia, Torre Guaceto, Cesine and Alimini. The aim of the study was to determine if PC are common elements of these transitional systems (lagoons, marshes and solar salterns) or whether they are only occasionally important during stochastic bloom events. PC mean abundances were all over the seven habitats more than one order of magnitude higher (>5 × 107 cells L-1) than those found in coastal and offshore waters of the Adriatic Sea. Their range of variability was also broader (105 109 cells L-1 vs. 106 108 cells L-1). PC populations appeared well adapted to ample variations in salinity (5 87). The highest abundances (close to 109 cells L-1) were found at extremely high/low salinity values. Even oxygen concentrations close to hypoxia did not seem to negatively affect PC abundances. Because of their ability in adapting to extreme conditions, PC may become the prevailing fraction of the phototrophic plankton in these sites and their role in such ecosystems should not be underestimated.

Paoli, Alessandro; Celussi, Mauro; Valeri, Annalisa; Larato, Chiara; Bussani, Andrea; Fonda Umani, Serena; Vadrucci, Maria Rosaria; Mazziotti, Cristina; Del Negro, Paola

2007-10-01

379

Nonequilibrium dynamics of phase transitions  

NASA Astrophysics Data System (ADS)

Phase transitions occur in such diverse and important systems as ferromagnets, liquid crystals and the early Universe. The dynamics of phase transitions such as these have been studied for decades, but the analytical models still need a great deal of improvement before they can adequately describe all time stages and regions under the coexistence curve. Numerical studies can supplement these analytical theories, but they need to accurately describe the continuum equations that they are intended to solve. This thesis describes a method for removing the lattice- spacing and renormalization-mass dependence of Langevin simulations of phase mixing in (2 + 1)-dimensional asymmetric Ginzburg-Landau models with short-ranged interactions. Also, the spread in the order parameter near the critical value of the control parameter due to critical slowing down is used to more accurately determine this value of the control parameter in these simulations. In addition, a new method is proposed for quantifying the departure from equilibrium. The method explores the behavior of the rate of change of the momentum-integrated structure function, ?Stot( t), as it evolves in time. As an illustration, we examine a (1 + 1)-dimensional model of a stochastic Ginzburg-Landau model at varying cooling rates. We show that ?Stot(t) displays a peak which scales with cooling time-scale as t1/2q in the over-damped limit and t1/3q in the underdamped limit. The peak amplitude was found to scale with cooling time-scale as t6/5q in all viscosities studied.

Gagne, Carmen Jeanne

2001-11-01

380

e-Transit: Electronic Business Strategies for Public Transportation. Volume 4: Advanced Features of Transit Websites.  

National Technical Information Service (NTIS)

TCRP Report 84 is being be published as multiple volumes. Volume 4: Advanced Features of Transit Websites explores the potential of the following advanced website features for the transit industry: automated itinerary planners, real-time customer informat...

2003-01-01

381

Determining Transit’s Impact on Seoul Commercial Land Values: An Application of Spatial Econometrics  

Microsoft Academic Search

Literature regarding transit’s impact on land values reports mixed results concerning the economic benefits of accessibility to subway stations, specifically regarding commercial properties. After examining 731 commercial land values in Seoul, Korea, this study suggests a possible explanation for the mixed results: transit’s discrimination impact on land values by location in a built-up urban area. The regression coefficient for distance

Jin Kim; Ming Zhang

2005-01-01

382

Transit Users’ Route?Choice Modelling in Transit Assignment: A Review  

Microsoft Academic Search

This paper reviews the main studies on transit users’ route choice in the context of transit assignment. The studies are categorized into three groups: static transit assignment, within?day dynamic transit assignment, and emerging approaches. The motivations and behavioural assumptions of these approaches are re?examined. The first group includes shortest?path heuristics in all?or?nothing assignment, random utility maximization route?choice models in stochastic

Yulin Liu; Jonathan Bunker; Luis Ferreira

2010-01-01

383

Making the Transition to Primary School: An Evaluation of a Transition Program for Parents  

Microsoft Academic Search

The transition to primary school is an important time for both children and parents. The aim of this randomized controlled study was to assess the effectiveness of a Transition to Primary School Parent Program in strengthening parent knowledge and confidence to manage the transition process, increasing parent involvement in their children's learning, and improving child adjustment to starting school. Participants

Rebecca Giallo; Karli Treyvaud; Jan Matthews

2010-01-01

384

Making the Transition to Primary School: An Evaluation of a Transition Program for Parents  

ERIC Educational Resources Information Center

The transition to primary school is an important time for both children and parents. The aim of this randomized controlled study was to assess the effectiveness of a Transition to Primary School Parent Program in strengthening parent knowledge and confidence to manage the transition process, increasing parent involvement in their children's…

Giallo, Rebecca; Treyvaud, Karli; Matthews, Jan; Kienhuis, Mandy

2010-01-01

385

Assessing the Dutch Energy Transition Policy: How Does it Deal with Dilemmas of Managing Transitions?  

Microsoft Academic Search

In the Netherlands, the national government is committed towards altering the systems of energy, transport and agriculture in the name of sustainable development. A process of deliberation and change was started—aimed at achieving ‘transitions’—using a model of transition management. This paper examines how the new arrangements of governance for energy transition deal with six problems of steering: ambivalence about goals,

René Kemp; Jan Rotmans; Derk Loorbach

2007-01-01

386

Easing the Transition to School: Administrators' Descriptions of Transition to School Activities  

ERIC Educational Resources Information Center

|This paper details the early childhood transition activities of three schools in southern Queensland, Australia, as reported by school administrators. The transition programs were analysed using the categories of the Transition to School Matrix of the New South Wales (NSW) Department of Education. Activities fell into the first four categories…

Noel, Andrea

2011-01-01

387

Transit and Health: Mode of Transport, Employer-Sponsored Public Transit Pass Programs, and Physical Activity  

Microsoft Academic Search

Increased provision of transit service and policy incentives that favor transit use can support a physically active lifestyle. We used the SMARTRAQ travel survey in metropolitan Atlanta, Georgia (in 2001-2002) to assess whether transit and car trips were associated with meeting the recommended levels of physical activity by using walking as a means of transportation. Additionally, we assessed associations between

D. F RANK

388

Transitioning multiagent technology to UAV applications  

Microsoft Academic Search

This paper describes the transition of academically devel- oped multiagent technology for UAV coordination to an in- dustrially developed application. The specific application is the use of lightweight UAVs with small Received Signal Strength Indicator sensors to cooperatively locate targets emitting radio frequency signals in a large area. It is shown that general techniques can be eectively transitioned, some- times

Paul Scerri; Tracy Von Gonten; Gerald Fudge; Sean Owens; Katia P. Sycara

2008-01-01

389

First observation of stimulated coherent transition radiation  

Microsoft Academic Search

Stimulated coherent transition radiation has been observed at the Stanford SUNSHINE facility. Far-infrared light pulses of coherent transition radiation emitted from femtosecond electron bunches are delayed and circulated in a special cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light work on the electrons, and thus stimulates more radiated energy.

Hung-chi Lihn; Pamela Kung; Chitrlada Settakorn; Helmut Wiedemann; David Bocek; M Hernández

1995-01-01

390

Youth Transitions: From Offending to Desistance  

ERIC Educational Resources Information Center

|This article examines youth transitions and youth offending in tandem. It argues that the transition to adulthood is heavily implicated in the fact that most offending occurs in the youth phase. Drawing on a study of 20 male and 20 female persistent young offenders in Scotland, it explores young people's desire for integration with others in the…

Barry, Monica

2010-01-01

391

Monte Carlo Methods in Transition Metal Alloys  

Microsoft Academic Search

Giant moments of several Bohr magnetons are formed in transition metal alloys where the matrix is palladium or platinum. The interaction between these giant moments produces a phase transition from paramagnetism to ferromagnetism, when the alloy is below the Curie temperature. These giant moments can be measured mainly by neutron diffraction, although several characteristics can be determined by magnetization measurements.

Rixio Parra

1997-01-01

392

Vector Bundle Moduli and Small Instanton Transitions  

Microsoft Academic Search

We give the general presciption for calculating the moduli of irreducible, stable SU(n) holomorphic vector bundles with positive spectral covers over elliptically fibered Calabi-Yau threefolds. Explicit results are presented for Hirzebruch base surfaces B = Bbb Fr. The transition moduli that are produced by chirality changing small instanton phase transitions are defined and specifically enumerated. The origin of these moduli,

Evgeny Buchbinder; Ron Donagi; Burt A. Ovrut

2002-01-01

393

Case Studies in Assessment for Transition Planning  

ERIC Educational Resources Information Center

This book presents a group of case studies to show how to assess students to develop a clear statement of transition service needs and then use that information for goals and objectives in their IEP or ITP (individual transition plan). The case studies format will help you see in a concrete way how assessment procedures relate to young people with…

Trainor, Audrey A.; Patton, James R.; Clark, Gary M.

2005-01-01

394

Hippocampal activation during transitive inference in humans  

Microsoft Academic Search

Studies in rodents have demonstrated that the integration and flexible expression of memories, necessary for transitive inference, depend on an intact hippocampus. To test this hypothesis in humans, we studied brain activation during the discrimination of a series of overlap- ping and non-overlapping arbitrary visual stimulus pairs. We report that transitive inference about overlapping pairs is associated with right ante-

Stephan Heckers; Martin Zalesak; Anthony P. Weiss; Tali Ditman; Debra Titone

2004-01-01

395

Informing Transitions in the Early Years  

ERIC Educational Resources Information Center

|An increased emphasis on an early start in group day care and educational settings for young children means that by the time children enter statutory education, they may already have had several transitional experiences: each will have an impact. This book explores early transitions from a variety of international perspectives. Each chapter is…

Dunlop, Aline-Wendy; Fabian, Hilary

2006-01-01

396

Capital transition period needs strong start.  

PubMed

The blending of hospitals' capital payments from Medicare with reimbursement for treatment won't be completed until the year 2002. But good recordkeeping will be critical for how hospitals will fare during the 10-year transition period, states Ronald Sutter. In fact, hospitals are already entering an important time frame in the transition process. PMID:10117582

Sutter, R

1992-04-27

397

On the Speed of Transition Central Europe  

Microsoft Academic Search

Transition in Central Europe is four years old. State firms which dominated the economy are struggling with market forces. A new private sector quickly emerged and has taken hold. Unemployment, which did not exist, is high and still increasing. Will this process of transition accelerate, or slow down? Will unemployment keep increasing? Can things go wrong and how? Our paper

Philippe Aghion; Olivier Jean Blanchard

1994-01-01

398

Winners and Losers in Russia's Economic Transition  

Microsoft Academic Search

The transition to a market economy has produced a substantial and rapid change in the wage structure in Russia. Household surveys taken before and after the transition indicate that overall wage inequality nearly doubled from 1991 to 1994 and has reached a level higher than that in the United States. Returns to both measured skills (education, occupation) and unmeasured skills

Elizabeth Brainerd

1998-01-01

399

An accelerated nutrition transition in Iran  

Microsoft Academic Search

Objective: To describe the emergence of the nutrition transition, and associated morbidity shifts, in the Islamic Republic of Iran. Design: Review and analysis of secondary data relating to the socio-political and nutritional context, demographic trends, food utilisation and consumption patterns, obesity, and diet-related morbidity. Results and conclusions: The nutrition transition in Iran is occurring rapidly, secondary to the rapid change

Hossein Ghassemi; Gail Harrison; Kazem Mohammad

2002-01-01

400

Transition: Old Wine in New Bottles.  

ERIC Educational Resources Information Center

The 1980s movement for improved transition of handicapped youth from school to work is considered in light of similar previous movements: (1) the career education movement of the 1970s and (2) the work/study movement of the 1960s. The influence of broad social issues (such as educational reform) on outcomes for the transition movement is stressed.…

Halpern, Andrew S.

1992-01-01

401

Global Azimuthal Anisotropy in the Transition Zone  

Microsoft Academic Search

Surface wave dispersion measurements for Love wave overtones carry evidence of azimuthal anisotropy in the transition zone of Earth's mantle (400 to 660 kilometers deep). A Backus-Gilbert inversion of anisotropic phase velocity maps, with resolution kernels mainly sensitive to the transition zone, shows a robust long-wavelength azimuthally anisotropic velocity structure. This observation puts new constraints on the mineralogy and dynamics

Jeannot Trampert; Hendrik Jan van Heijst

2002-01-01

402

Parametric subspace modelling of speech transitions  

Microsoft Academic Search

We report on attempting to capture segmental transition information for speech recognition tasks. The slowly varying dynamics of spectral trajectories carries much discriminant information that is very crudely modelled by traditional approaches such as HMMs. In attempts such as recurrent neural networks there is the hope, but not convincing demonstration, that such transitional information could be captured. We start from

K. Reinhard; M. Niranjan

1998-01-01

403

Parametric subspace modeling of speech transitions  

Microsoft Academic Search

This report describes an attempt at capturing segmental transition information for speech recognitiontasks. The slowly varying dynamics of spectral trajectories carries much discriminant informationthat is very crudely modelled by traditional approaches such as HMMs. In approachessuch as recurrent neural networks there is the hope, but not the convincing demonstration, thatsuch transitional information could be captured. The method presented here starts

K. Reinhard; M. Niranjan

1999-01-01

404

Synthesizing transition textures on succession patterns  

Microsoft Academic Search

Synthesizing transition textures on succession patterns for displaying visually acceptable terrain is essential to applications such as computer games. In this paper, we exploited the Game of Life model to simulate successions on terrain to show that a good-looking profile can appear quickly and easily. Based on the proposed modified patch-based sampling texture synthesis approach, the basic types of transition

Yueh-Yi Lai; Wen-Kai Tai; Chin-Chen Chang; Chen-Duo Liu

2005-01-01

405

Artificial Intelligence for Transit Railcar Diagnostics  

Microsoft Academic Search

Artificial Intelligence for Transit Railcar Diagnostics documents and presents the results of a study to determine the feasibility of applying Artificial Intelligence (AI) techniques to the diagnosis of transit railcars. The AI techniques investigated were expert systems, case-based reasoning, model-based reasoning, artificial neural networks, computer vision, fuzzy logic, and a procedural knowledge-based system.

Ian P Mulholland; Raymond A. Oren

1994-01-01

406

About the Dynamics of Structural Phase Transitions.  

National Technical Information Service (NTIS)

The dynamics of structural phase transitions with a fourth order interaction between the soft phonon fields is studied in the 1/n approximation, using many body methods at finite temperatures. Two limits are considered: high transition temperature T sub(c...

J. T. N. Medeiros

1975-01-01

407

Electrically driven phase transition in magnetite nanostructures  

NASA Astrophysics Data System (ADS)

Magnetite (Fe3O4), an archetypal transition-metal oxide, has been used for thousands of years, from lodestones in primitive compasses to a candidate material for magnetoelectronic devices. In 1939, Verwey found that bulk magnetite undergoes a transition at TV~120K from a high-temperature `bad metal' conducting phase to a low-temperature insulating phase. He suggested that high-temperature conduction is through the fluctuating and correlated valences of the octahedral iron atoms, and that the transition is the onset of charge ordering on cooling. The Verwey transition mechanism and the question of charge ordering remain highly controversial. Here, we show that magnetite nanocrystals and single-crystal thin films exhibit an electrically driven phase transition below the Verwey temperature. The signature of this transition is the onset of sharp conductance switching in high electric fields, hysteretic in voltage. We demonstrate that this transition is not due to local heating, but instead is due to the breakdown of the correlated insulating state when driven out of equilibrium by electrical bias. We anticipate that further studies of this newly observed transition and its low-temperature conducting phase will shed light on how charge ordering and vibrational degrees of freedom determine the ground state of this important compound.

Lee, Sungbae; Fursina, Alexandra; Mayo, John T.; Yavuz, Cafer T.; Colvin, Vicki L.; Sumesh Sofin, R. G.; Shvets, Igor V.; Natelson, Douglas

2008-02-01

408

Transition Leadership in a Shifting Policy Environment  

ERIC Educational Resources Information Center

|While transformational leadership has received much attention in recent years, the purpose of this article is to explicate the concept of transition leadership and its centrality to understanding policy implementation and school change through a case study of one district and its school principals, transitioning from court-ordered desegregation…

Goldring, Ellen; Crowson, Robert; Laird, David; Berk, Robert

2003-01-01

409

Transitions and the Development of Expertise  

ERIC Educational Resources Information Center

|This paper explores the relationships between the development of expertise and transitions. It sets out what we know about the development of expertise, changes in the brain as expertise develops, and how transitions between different learning contexts and the challenges that they present may impact on developing expertise. It sets out a series…

Hallam, Susan

2010-01-01

410

Building Bridges: Understanding Student Transition to University  

ERIC Educational Resources Information Center

|This article explores challenges in ensuring effective student transition from school or college to university. It examines the complex liaison needed for students to progress to appropriate courses, settle into university life and succeed as higher education learners. Secondary data (international literature on transition and the formation of…

Briggs, A. R. J.; Clark, J.; Hall, I.

2012-01-01

411

Saying Goodbye: Making Hard Transitions Easier.  

ERIC Educational Resources Information Center

|Discusses ways child caregivers can help the children they care for cope with separation anxiety by preparing for transitions. Includes suggestions for preparing the classroom, helping children and parents become comfortable in the classroom, and using rituals to make transitions easier for children and parents at the beginning and the end of the…

Texas Child Care, 1999

1999-01-01

412

Phase Transitions in Ferroelectric and Antiferroelectric Crystals  

Microsoft Academic Search

Group theory is applied to phase transitions in ferroelectric and antiferroelectric crystals. The procedure is given to derive for a paraelectric crystal with a given space group all possible ferroelectric states which can exist for arbitrarily small values of the polarization. A knowledge of the space groups of the crystal above and below the transition point makes it possible to

C. Haas

1965-01-01

413

Lowest Energy Singlet Transition in Biphenyl  

Microsoft Academic Search

The lowest energy band in the electronic absorption spectrum of biphenyl is broad and structureless. Considering a spectral comparison of biphenyl and related molecules, Platt suggested that this band results from two different electronic transitions. Similarly, after making a fluorescence lifetime study, Berlman and Steingraber predicted that the first singlet transition should be forbidden and thus the broad band should

G. Traverso; J. E. Brunet

1980-01-01

414

Transit Operator Health and Wellness Programs  

Microsoft Academic Search

This synthesis will be of interest to transit staff concerned with proactively addressing operator health and wellness issues at their agencies. The report documents current information on prevention and intervention strategies and resources that can be used by transit agencies. It offers survey information obtained from individuals with the responsibility for managing health and wellness programs. This synthesis covers the

M. J. Davis

2004-01-01

415

An Exploratory Study of Transition, Inc.  

ERIC Educational Resources Information Center

In this paper the Transition, Inc. program of the city of Miami is examined. This program's main concern is to help ex-offenders in their re-socialization process by offering them moral as well as financial support. It is evidenced from the goal and objectives of the Transition, Inc. program, its rehabilitative results and related literature that…

Hogges, Ralph; Hogges, Lilia

416

Deriving Petri Nets for Finite Transition Systems  

Microsoft Academic Search

This paper presents a novel method to derive a Petri Net from any specification model that can be mapped into a statebasedrepresentation with arcs labeled with symbols from an alphabet of events (a Transition System, TS). The method is based onthe theory of regions for Elementary Transition Systems (ETS). Previous work has shown that, for any ETS, there exists a

Jordi Cortadella; Michael Kishinevsky; Luciano Lavagno; Alexandre Yakovlev

1998-01-01

417

QCD Phase Transition in Dgp Brane Cosmology  

NASA Astrophysics Data System (ADS)

In the standard picture of cosmology it is predicted that a phase transition, associated with chiral symmetry breaking after the electroweak transition, has occurred at approximately 10? seconds after the Big Bang to convert a plasma of free quarks and gluons into hadrons. We consider the quark-hadron phase transition in a Dvali, Gabadadze and Porrati (DGP) brane world scenario within an effective model of QCD. We study the evolution of the physical quantities useful for the study of the early universe, namely, the energy density, temperature and the scale factor before, during and after the phase transition. Also, due to the high energy density in the early universe, we consider the quadratic energy density term that appears in the Friedmann equation. In DGP brane models such a term corresponds to the negative branch (? = -1) of the Friedmann equation when the Hubble radius is much smaller than the crossover length in 4D and 5D regimes. We show that for different values of the cosmological constant on a brane, ?, phase transition occurs and results in decreasing the effective temperature of the quark-gluon plasma and of the hadronic fluid. We then consider the quark-hadron transition in the smooth crossover regime at high and low temperatures and show that such a transition occurs along with decreasing the effective temperature of the quark-gluon plasma during the process of the phase transition.

Atazadeh, K.; Ghezelbash, A. M.; Sepangi, H. R.

2012-08-01

418

Light rail transit in the United States  

Microsoft Academic Search

In recent years interest in light rail transit has grown substantially in the United States. The concept of LRT is increasingly viewed as a possible answer to the search for a less costly rail transit technology that could reduce America's dependency on the private automobile and put the country on the road to a more secure, self-sufficient energy future. The

Stewart F. Taylor

1980-01-01

419

Branding and Bricolage. Gender, Consumption and Transition  

ERIC Educational Resources Information Center

|The analysis presented here focuses on the relationship between femininity, transition and consumer culture. It explores the relationship between gender and consumer culture in the context of a discussion of the transition from childhood to teenage status for a group of young girls, and seeks to make a critical contribution to contemporary…

Russell, Rachel; Tyler, Melissa

2005-01-01

420

Middle Grades Transition Programs around the Globe  

ERIC Educational Resources Information Center

Transitions into and out of the middle grades can be challenging for many reasons. Students need to acclimate to new policies, practices, and buildings; teachers require accurate data about their new students' capacities; and families must navigate relationships with new personnel. All school transitions present different and, at times, puzzling…

Andrews, Colin; Bishop, Penny

2012-01-01

421

Direct entrants in transition: becoming independent learners  

Microsoft Academic Search

This article investigates the dynamic transitions that college leavers make to university. It draws on qualitative research with a group of students who took direct entry to the second or third year of a degree programme at university, to show that successful transitions depend on the students becoming independent learners. It argues that the students who adapt best to the

Hazel Christie; Paul Barron; Norma DAnnunzio-Green

2011-01-01

422

PUBLIC TRANSIT ACCESS TO PRIVATE PROPERTY  

Microsoft Academic Search

Under contract with the Florida Department of Transportation, the Center for Urban Transportation Research was asked to (a) assess the issues surrounding the legal rights of public transit agencies to enter and serve private property, and (b) identify the major concerns of private property owners as they relate to allowing access to their property by public transit providers. The scope

Dennis Hinebaugh; Lisa Staes

2001-01-01

423

Comments on the electroweak phase transition  

Microsoft Academic Search

We report on an investigation of various problems related to the theory of the electroweak phase transition. This includes a determination of the nature of the phase transition, a discussion of the possible role of higher order radiative corrections and the theory of the formation and evolution of the bubbles of the new phase. We find in particular that no

Michael Dine; Robert G. Leigh; Patrick Huet; Andrei Linde; Dmitri Linde

1992-01-01

424

Phase Transition of N-Component Superconductors  

Microsoft Academic Search

We investigate the phase transition in the three-dimensional Abelian Higgs model for N complex scalar fields, using the gauge-invariant average action Gammak. The dependence of Gammak. on the effective infrared cutoff k is described by a nonperturbative flow equation. The transition turns out to be first or second order, depending on the ratio between the scalar and gauge coupling. We

B. Bergerhoff; D. F. Litim; S. Lola; C. Wetterich

1996-01-01

425

Women in Cross-Cultural Transitions.  

ERIC Educational Resources Information Center

|This series of 14 essays focuses on experiences of women who have made cross-cultural transitions. Cross-cultural transitions refer to moving across cultures, usually from one country to another or across subcultures within one society. The essays document what individual women perceived, how they felt when in the process of moving from one…

Bystydzienski, Jill M., Ed.; Resnik, Estelle P., Ed.

426

Fe XIX transition probabilities (Jonauskas+, 2004)  

NASA Astrophysics Data System (ADS)

Energy levels and the corresponding transition probabilities as well oscillator strengths and line strengths for allowed (E1) and forbidden (E2, M1) transitions among the lowest 656 levels of oxygen-like Fe XIX are presented. Calculations were performed using the multiconfigurational Dirac-Fock GRASP code. (3 data files).

Jonauskas, V.; Keenan, F. P.; Foord, M. E.; Heeter, R. F.; Rose, S. J.; Ferland, G. J.; Kisielius, R.; van Hoof, P. A. M.; Norrington, P. H.

2004-09-01

427

Transition probabilities for Fe XVIII (Jonauskas+, 2004)  

NASA Astrophysics Data System (ADS)

Energy levels and the corresponding transition probabilities as well oscillator strengths and line strengths for allowed (E1) and forbidden (E2, M1) transitions among the lowest 379 levels of fluorine-like Fe XVIII are presented. Calculations were performed using the multiconfigurational Dirac-Fock GRASP code. (4 data files).

Jonauskas, V.; Keenan, F. P.; Foord, M. E.; Heeter, R. F.; Rose, S. J.; van Hoof, P. A. M.; Ferland, G. J.; Aggarwal, K. M.; Kisielius, R.; Norrington, P. H.

2003-11-01

428

Transitioning from High School: A Postgraduate Study  

Microsoft Academic Search

Individuals transitioning from college face many decisions about their future. Making these decisions is not always easy for some. The role of all individuals involved in a high school is to prepare students for life after high school. A review of past postgraduate data was explored as well as programs that have been implemented to help students transition. A postgraduate

Krystal B Dunning

2009-01-01

429

The Transition out of High School  

Microsoft Academic Search

LEARNING OUTCOME: To identify increased cancer risk behaviors during the transition out of high school.Low intakes of fruits and vegetables (F&V) are related to increased cancer risk Little research has focused on dietary behavior in the transition out of high school (HS), when diet is likely to change due to changes in school status, employment, living arrangements, income, and marital

K. W. Cullen; T. Baranowski

1996-01-01

430

Modulation of orocaecal transit time by hypnosis.  

PubMed Central

The ability of hypnosis to modulate the orocaecal transit time of 10 g lactulose was tested in six healthy volunteers. Orocaecal transit time was measured by the hydrogen breath test during three periods in random order. During the control period the subjects remained throughout the test in a semirecumbent position without moving. During the hypnotic relaxation period subjects were hypnotised before lactulose ingestion and were instructed to experience relaxation till the orocaecal transit time had elapsed. During the acceleration suggestion period subjects were hypnotised before lactulose ingestion and were repeatedly instructed to imagine the acceleration of lactulose through the intestine until transit time had elapsed. The mean orocaecal transit time was significantly longer during the hypnotic relaxation period (mean (SEM) 133 (8) min) than during the control period (93 (13) min). The mean orocaecal transit time during the acceleration suggestion period was 105 (26) minutes and was not significantly different from the mean transit time during the control period. The individual values during the acceleration suggestion period were scattered. We conclude that lactulose orocaecal transit time is delayed during hypnotic relaxation.

Beaugerie, L; Burger, A J; Cadranel, J F; Lamy, P; Gendre, J P; Le Quintrec, Y

1991-01-01

431

The knowledge society: the challenge of transition  

Microsoft Academic Search

Considers the rapid transition that is taking place from an industrial to a knowledge society and analyzes the components that are likely to comprise such a knowledge society. Explores the nature of that transition and how people will cope with this period of profound change. Points to the lead taken in mobile technologies and interactive TV in Europe compared to

Chris Yapp

2000-01-01

432

Transit employee attitudes toward merit pay  

Microsoft Academic Search

Merit pay programs are the most widely used financial incentive program among urban mass transit systems. An attitude survey was conducted at a large transit system to determine how employees perceived the merit pay program in which they participated. Employee attitudes toward the merit pay system were mixed. Their perceptions of the accuracy of the performance evaluation were quite negative.

Dow Scott; M J Vest; F S Hills; S E Markham

1987-01-01

433

Electron microscopy: Phase transition singled out  

NASA Astrophysics Data System (ADS)

Four-dimensional electron microscopy has been applied to the detailed characterization of metal-organic-framework nanoparticles undergoing an electronic transition. The transition characteristics of a single particle were found to differ from those of an ensemble, and also to vary from one nanoparticle to the next.

Browning, Nigel D.

2013-05-01

434

Skills constraints and the low carbon transition  

Microsoft Academic Search

Achieving a successful transition to a low carbon economy, in the UK and other countries, will require sufficient people with appropriate qualifications and skills to manufacture, install, and operate the low carbon technologies and approaches. The actual numbers and types of skills required are uncertain and will depend on the speed and direction of the transition pathways, but there are

Nick Jagger; Tim Foxon; Andy Gouldson

2012-01-01

435

THE PROBLEM OF TRANSITION IN PALEONTOLOGY  

Microsoft Academic Search

The author equates paleontology and phylogeny and discusses principles and problems of transitions found in the phylogentic approach to taxonomy. opics discussed include: subspecies and species (time needed for new species to become isolated is 500 to 1,000 years); the morphological exclusiveness of genera in the differential diagnoses of species, evolutionary patterns of transition in time, the biogenetic law (“Ontogenesis

V. Ye. Ruzhentsev

1964-01-01

436

Changes and Exchanges in Marginal Youth Transitions  

ERIC Educational Resources Information Center

|While some groups of young people may negotiate successful transitions to work, others are unable or unlikely to do so. The concept of "fair exchange" is pertinent to understanding youth transitions in their formative stages through educational experiences. Patterns of disrupted education challenge the education-work nexus not only because…

Bottrell, Dorothy; Armstrong, Derrick

2007-01-01

437

Method for dry etching of transition metals  

DOEpatents

A method for dry etching of transition metals. The method for dry etching of a transition metal (or a transition metal alloy such as a silicide) on a substrate comprises providing at least one nitrogen- or phosphorous-containing .pi.-acceptor ligand in proximity to the transition metal, and etching the transition metal to form a volatile transition metal/.pi.-acceptor ligand complex. The dry etching may be performed in a plasma etching system such as a reactive ion etching (RIE) system, a downstream plasma etching system (i.e. a plasma afterglow), a chemically-assisted ion beam etching (CAIBE) system or the like. The dry etching may also be performed by generating the .pi.-acceptor ligands directly from a ligand source gas (e.g. nitrosyl ligands generated from nitric oxide), or from contact with energized particles such as photons, electrons, ions, atoms, or molecules. In some preferred embodiments of the present invention, an intermediary reactant species such as carbonyl or a halide ligand is used for an initial chemical reaction with the transition metal, with the intermediary reactant species being replaced at least in part by the .pi.-acceptor ligand for forming the volatile transition metal/.pi.-acceptor ligand complex.

Ashby, Carol I. H. (Edgewood, NM); Baca, Albert G. (Albuquerque, NM); Esherick, Peter (Albuquerque, NM); Parmeter, John E. (Albuquerque, NM); Rieger, Dennis J. (Tijeras, NM); Shul, Randy J. (Albuquerque, NM)

1998-01-01

438

Method for dry etching of transition metals  

DOEpatents

A method for dry etching of transition metals is disclosed. The method for dry etching of a transition metal (or a transition metal alloy such as a silicide) on a substrate comprises providing at least one nitrogen- or phosphorus-containing {pi}-acceptor ligand in proximity to the transition metal, and etching the transition metal to form a volatile transition metal/{pi}-acceptor ligand complex. The dry etching may be performed in a plasma etching system such as a reactive ion etching (RIE) system, a downstream plasma etching system (i.e. a plasma afterglow), a chemically-assisted ion beam etching (CAIBE) system or the like. The dry etching may also be performed by generating the {pi}-acceptor ligands directly from a ligand source gas (e.g. nitrosyl ligands generated from nitric oxide), or from contact with energized particles such as photons, electrons, ions, atoms, or molecules. In some preferred embodiments of the present invention, an intermediary reactant species such as carbonyl or a halide ligand is used for an initial chemical reaction with the transition metal, with the intermediary reactant species being replaced at least in part by the {pi}-acceptor ligand for forming the volatile transition metal/{pi}-acceptor ligand complex.

Ashby, C.I.H.; Baca, A.G.; Esherick, P.; Parmeter, J.E.; Rieger, D.J.; Shul, R.J.

1998-09-29

439

Transitioning from High School to College.  

ERIC Educational Resources Information Center

|These four conference papers from the Biennial Conference on Postsecondary Education for Persons who are Deaf or Hard of Hearing focus on transitioning from high school to college. The first paper, "Transitioning Collaboration with Schools and Vocational Rehabilitation" (Catherine Wilson and Wayne Giese), describes the North Carolina School for…

Kolvitz, Marcia, Ed.

440

The Supported Teen: Transitioning to High School  

ERIC Educational Resources Information Center

Transition plans for students with special needs provide support for social and academic success while giving students an accurate picture of what to expect in high school. The Texas Comprehensive Center recommends that schools develop a comprehensive transition plan district-wide. This district plan must include the cooperation of staff from the…

Dorman, Benton

2012-01-01

441

Infant Mother Vocalization Patterns in Transition.  

ERIC Educational Resources Information Center

|Video-analysis was used to investigate the transition from coacting to alternating patterns of infant-mother vocalizations in this longitudinal study of one infant. In addition to investigating the transition and its developmental implications, the relationship between the temporal patterning of kinesic and vocal behaviors was studied. The study…

Kilbourne, Brock K.; Ginsburg, Gerald P.

442

Women in Cross-Cultural Transitions.  

ERIC Educational Resources Information Center

This series of 14 essays focuses on experiences of women who have made cross-cultural transitions. Cross-cultural transitions refer to moving across cultures, usually from one country to another or across subcultures within one society. The essays document what individual women perceived, how they felt when in the process of moving from one…

Bystydzienski, Jill M., Ed.; Resnik, Estelle P., Ed.

443

Improving High School Transition with CAT Camp  

ERIC Educational Resources Information Center

|Transition to a new school for adolescent students can be challenging. Students who have difficulty navigating the transition to ninth grade are at an increased disadvantage academically and personally. Even students who approach the move with excitement often have unrealistic expectations of what is necessary for success. Overall, those who do…

Geltner, Jill; Law, Brian; Forehand, Amanda; Miles, Dinah Amber

2011-01-01

444

Exploiting Transition Locality in Automatic Verification  

Microsoft Academic Search

In this paper we present an algorithm to contrast state explosion when using Explicit State Space Exploration to verify protocols. We show experimentally that protocols exhibit transition locality. We present a verification algorithm that exploits transition locality as well as an implementation of it within the Murphi verifier. Our algorithm is compatible with all Breadth First (BF) optimization techniques present

Enrico Tronci; Giuseppe Della Penna; Benedetto Intrigila; Marisa Venturini Zilli

2001-01-01

445

Ultraviolet lasing transitions in diatomic molecules  

NASA Astrophysics Data System (ADS)

The work performed is primarily directed toward a better spectroscopic understanding of UV laser transitions in selected diatomic molecules. Specifically the work emphasizes the analysis of spectroscopic data for discrete (bound-bound) and diffuse (bound-free) transitions in the rare gas monohalide (RgX) molecules and discrete transitions in the homonuclear halogens. The primary accomplishments of the work include detailed rotational and vibrational analyses of the lasing B to X transition in XeF (3500 A) and the lasing D: to A: transition in Br2 (2900 A); (2) vibrational analyses of the lasing transitions B to X in XeCl (3100 A) and D: to A: in I2 (3400 A), and the nonlasing D to X transitions in XeF (2600 A) and XeCl (2350 A); analysis of the bound-free B to X and D to X transitions in other RgX molecules, with emphasis on KrCl; reanalysis of the D to X UV fluorescence spectrum of I2; determination of potential curves and intensity factors (Franck-Condon factors, stimulated emission cross sections) for all analyzed systems; determination of the energy ordering of the B and C states in KrCl, XeCl, and XeBr, using temperature-dependent emission spectroscopy; and characterization of a tesla discharge with respect to its temporal and thermal properties and its total radiant output.

Tellinghuisen, J.

1980-01-01

446

Stiffness transition in anisotropic fiber nets.  

PubMed

We demonstrate the existence of a percolationlike stiffness transition in fiber networks with a bidisperse orientation distribution and with fiber densities clearly above the geometrical and the ordinary stiffness transition. The fibers are oriented parallel and perpendicular to a strain direction and they have a large fiber aspect ratio. The stiffness K of the fiber nets can be described by a scaling relation, K [proportionally] ?(?) g[(? - ?(c))/?(-?)], where ? is the fraction of fibers parallel to strain. g is a scaling function that is roughly described by a power law g(x) [proportionally ] x(?) for stiffness above the transition and by a constant below the transition. The transition point is characterized by qualitative changes in the distribution of the elastic deformation energy of the fibers, the deformation mode of the fibers, the effective Poisson ratio of the nets, the distribution of elastic energy on fibers and cross links, and the ratio of elastic and viscous dissipation energy. This transition opens the possibility of extreme stiffness variations with minimal mesh manipulations in the vicinity of the transition (i.e., a stiffness gate). It is possible that this transition affects the mechanical behavior of the cytoskeleton in cells. PMID:23005800

Åström, J A; Sunil Kumar, P B; Karttunen, Mikko

2012-08-23

447

Structure and Agency in Transition Research  

ERIC Educational Resources Information Center

Based on the results of transition studies in the UK, Germany, USA and Canada, the virtues of analysing the structural contexts, institutional arrangements and the young peoples' action orientations are presented. In the first decade of the twenty-first century, school and the labour market have become more and more decoupled and transition routes…

Heinz, Walter R.

2009-01-01

448

Transiting areas patrolled by a mobile adversary  

Microsoft Academic Search

We study the problem of a mobile agent trying to cross an area patrolled by a mobile adversary. The transiting agent aims to choose its route so as to minimize the probability of hostile encounter; the patroller agent, controlling one or more patrol units, aims at the opposite. We model the problem as a two-player zero-sum game (termed transit game)

O. Vanek; B. Bosansky; M. Jakob; M. Pechoucek

2010-01-01

449

Introduction to Public Finance and Public Transit.  

National Technical Information Service (NTIS)

The report provides a comprehensive description of the elements of public finance, particularly as they relate to public transit issues. The report is intended to serve as a primer for the staff of the Federal Transit Administration (FTA) and staff of tra...

1993-01-01

450

Symmetry and Phase Transitions in Nuclei  

SciTech Connect

The role of symmetry in (shape) quantum phase transitions (QPT) in nuclei is briefly reviewed. Finite size scaling is discussed. The concepts of excited state quantum phase transitions (ESQPT) and of critical matter are introduced. The ab initio theory of QPT is mentioned.

Iachello, Francesco [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120 (United States)

2009-08-26

451

Transit bus operation with methanol fuel  

Microsoft Academic Search

American and European technology is being used to demonstrate the suitability of neat methanol as a fuel for transit buses. The project is sponsored by the California Energy Commission (CEC), and transit buses are being operated by the Golden Gate Bridge, Highway and Transportation District (GGTD). Project management and bus testing are performed by Acurex Corporation. Test data are being

M. D. Jackson; S. Unnasch; C. Sullivan; R. A. Renner

1985-01-01

452

Transit bus operation with methanol fuel  

Microsoft Academic Search

American and European technology is being used to demonstrate the suitability of neat methanol as a fuel for transit buses. The project is sponsored by the California Energy Commission (CEC), and transit buses are being operated by the golden Gate Bridge, Highway and Transportation District (GGTD). Project management and bus testing are performed by Acurex Corporation. Test data are being

M. D. Jackson; S. Unnasch; C. Sullivan

1985-01-01

453

Theory for photoinduced structural phase transitions  

Microsoft Academic Search

For the photoinduced ionic-->neutral structural phase transition in the organic charge transfer crystal TTF-CA, we, at first, theoretically show the adiabatic path of this transition, which starts from a single charge transfer (CT) exciton in the ionic phase, but finally results in a macroscopic neutral domain. In the next, using a more simplified model, we theoretically study nonlinear nonequilibrium quantum

H. Mizouchi; H. Ping; K. Nasu

2001-01-01

454

Athermal Character of Structural Phase Transitions  

Microsoft Academic Search

The significance of thermal fluctuations in nucleation in structural first-order phase transitions has been examined. The prototypical case of martensitic transitions has been experimentally investigated by means of acoustic emission techniques. We propose a model based on the mean first-passage time to account for the experimental observations. Our study provides a unified framework to establish the conditions for isothermal and

Francisco J. Pérez-Reche; Eduard Vives; Lluís Mañosa; Antoni Planes

2001-01-01

455

Understanding the Atmospheres of Transiting Extrasolar Planets  

Microsoft Academic Search

Transiting planets, those which just happen to lie in near edge-on orbits and pass periodically between Earth and their parent star, are quite rare. Of those discovered so far, only a few have been found within 100 pc. These objects are critically important for understanding extrasolar planets, given the variety of observational approaches that are made available by their transiting

Travis Barman

2007-01-01

456

High School to Employment Transition: Contemporary Issues.  

ERIC Educational Resources Information Center

This book contains 24 articles discussing the transition to employment for noncollege-bound youths in the United States. The book is organized around four major themes: background, reviews of research on students' transition experiences, employers' needs, and government efforts; analysis of programs, including successful ones in western Europe and…

Pautler, Albert J., Jr., Ed.

457

Quantum phase transitions for excited states  

SciTech Connect

The impact of the ground-state quantum phase transitions on the evolution of excited levels in the critical parameter region is discussed. The analysis is focused on systems with first- and second-order transitions and is illustrated by the cusp and nuclear collective Hamiltonians.

Cejnar, P.; Stransky, P. [Inst., of Particle and Nuclear Physics, Charles University, V Holesovickach 2, Prague, CZ-18000 (Czech Republic)

2009-01-28

458

Crumpling and buckling transitions in polymerized membranes  

Microsoft Academic Search

We consider polymerized non-self-avoiding membranes fluctuating under constrained boundary conditions. Such constraints prevent the membranes from being crumpled at high temperature and introduce a tension. Upon lowering the temperature this tension reduces, and vanishes at a transition temperature below which the membrane assumes a buckled state. Buckling transition points, depending on boundary conditions, arrange on a line which terminates at

E. Guitter; F. David; S. Leibler; L. Peliti

1988-01-01

459

Transitive Mesh Space of a Progressive Mesh  

Microsoft Academic Search

This paper investigates the set of all selectively refined meshes that can be obtained from a progressive mesh. We call the set the transitive mesh space of a progressive mesh and present a theoretical analysis of the space. We define selective edge collapse and vertex split transformations, which we use to traverse all selectively refined meshes in the transitive mesh

Junho Kim; Seungyong Lee

2003-01-01

460

S-Shaped Transition and Catapult Effects  

Microsoft Academic Search

Among the rich economies of the world today, per capita output levels had typically diverged before converging to the per capita output level of the frontier economy. Since frontier economies have grown at stable rates, non-frontier economies display an S-shape aggregate transition path. Along this transition, there are \\

Hyeok Jeong; Yong Kim

2006-01-01

461

Economic vulnerability and the energy transition  

Microsoft Academic Search

The United States is currently undergoing a transition from rapidly depleting nonrenewable energy sources to ''backstop'' energy sources. A system dynamics model has been developed to analyze the macroeconomic effects of the energy transition. GNP, consumption, investment, wages and prices, and other major energy and economic aggregates are determined endogenously. The model shows how delays in substitution and the development

1983-01-01

462

Stiffness transition in anisotropic fiber nets  

NASA Astrophysics Data System (ADS)

We demonstrate the existence of a percolationlike stiffness transition in fiber networks with a bidisperse orientation distribution and with fiber densities clearly above the geometrical and the ordinary stiffness transition. The fibers are oriented parallel and perpendicular to a strain direction and they have a large fiber aspect ratio. The stiffness K of the fiber nets can be described by a scaling relation, K???g[(?-?c)/?-?], where ? is the fraction of fibers parallel to strain. g is a scaling function that is roughly described by a power law g(x)?x? for stiffness above the transition and by a constant below the transition. The transition point is characterized by qualitative changes in the distribution of the elastic deformation energy of the fibers, the deformation mode of the fibers, the effective Poisson ratio of the nets, the distribution of elastic energy on fibers and cross links, and the ratio of elastic and viscous dissipation energy. This transition opens the possibility of extreme stiffness variations with minimal mesh manipulations in the vicinity of the transition (i.e., a stiffness gate). It is possible that this transition affects the mechanical behavior of the cytoskeleton in cells.

Åström, J. A.; Sunil Kumar, P. B.; Karttunen, Mikko

2012-08-01

463

Transition currents of superconducting magnet system  

Microsoft Academic Search

The normal transition of a superconducting magnet may be initiated by the instability of the superconducting state. This instability develops in the winding in transient regimes at certain definite values of transport current, l(t), and magnetic field, B(t ). In the present work the transition current, Ira, of the superconducting magnet system has been measured and calculated theoretically. The calcula-

V. V. Andrianov; V. P. Baev; S. S. Ivanov; R. G. Mints; A. L. Rakhmanov

1990-01-01

464

Dynamic transitions of surface tension driven convection  

NASA Astrophysics Data System (ADS)

We study the well-posedness and dynamic transitions of the surface tension driven convection in a three-dimensional (3D) rectangular box with non-deformable upper surface and with free-slip boundary conditions. It is shown that as the Marangoni number crosses the critical threshold, the system always undergoes a dynamic transition. In particular, two different scenarios are studied. In the first scenario, a single mode losing its stability at the critical parameter gives rise to either a Type-I (continuous) or a Type-II (jump) transition. The type of transition is dictated by the sign of a computable non-dimensional parameter, and the numerical computation of this parameter suggests that a Type-I transition is favorable. The second scenario deals with the case where the geometry of the domain allows two critical modes which possibly characterize a hexagonal pattern. In this case we show that the transition can only be either a Type-II or a Type-III (mixed) transition depending on another computable non-dimensional parameter. We only encountered Type-III transitions in our numerical calculations. The second part of the paper deals with the well-posedness and existence of global attractors for the problem.

Dijkstra, Henk; Sengul, Taylan; Wang, Shouhong

2013-03-01

465

Phenacite-Spinel Transition in LIALGEO4.  

National Technical Information Service (NTIS)

Since a phenacite-spinel transition was observed in LiZnVO4 at high pressures it was expected that similar transitions might be observed in silicates. Although the high-pressure experiments with alpha-eucryptite have been unsuccessful, this paper reports ...

A. M. Gaines A. J. Perrotta D. A. Stephenson

1966-01-01

466

Facilitator's Manual: Summer Transitions. Fifth Edition.  

ERIC Educational Resources Information Center

|A facilitator's manual for the Summer Transition Enrichment Program at Bowling Green State University is presented. The overall objectives of the program are: (1) to facilitate the transition of entering freshmen into the academic and cultural life of the university; and (2) to assist students in their personal growth and adjustment to the…

Kuenzli, Linda A., Ed.

467

Structural transitions in nanoscale systems  

NASA Astrophysics Data System (ADS)

In this work I investigate three different materials: nanoscale carbon systems, ferrofluid systems, and molecular-electronic devices. In particular, my study is focused on the theoretical understanding of structural changes and the associated electronic, mechanical, and magnetic properties of these materials. To study the equilibrium packing of fullerenes in carbon nanotube peapods optimization techniques were applied. In agreement with experimental measurements, my results for nanotubes containing fullerenes with 60--84 atoms indicate that the axial separation between the fullerenes is smaller than in the bulk crystal. The reduction of the inter-fullerene distance and also the structural relaxation of fullerenes result from a large internal pressure within the peapods. This naturally induced "static" pressure may qualify nanotubes as nanoscale autoclaves for chemical reactions. Combining total energy calculations with a search of phase space, I investigated the microscopic fusion mechanism of C60 fullerenes. I show that the (2+2) cycloaddition reaction, a necessary precursor for fullerene fusion, can be accelerated inside a nanotube. Fusion occurs along the minimum energy path as a finite sequence of Stone-Wales (SW) transformations. A detailed analysis of the transition states shows that Stone-Wales transformations are multi-step processes. I propose a new microscopic mechanism to explain the unusually fast fusion process of carbon nanotubes. The detailed pathway for two adjacent (5, 5) nanotubes to gradually merge into a (10, 10) tube, and the transition states have been identified. The propagation of the fused region is energetically favorable and proceeds in a morphology reminiscent of a Y-junction via a so called zipper mechanism, involving only SW bond rearrangements with low activation barriers. Using density functional theory, the equilibrium structure, stability, and electronic properties of nanostructured, hydrogen terminated diamond fragments have been studied. Such diamondoids can enter spontaneously into carbon nanotubes where polymerization of diamondoids is favourable. I studied the equilibrium structure of large but finite aggregates of magnetic dipoles, modeling a colloidal suspension of magnetite particles in a ferrofluid. With increasing system size, the structural motif evolves from chains and rings to multi-chain and multi-ring assemblies. These structural changes depend on external parameters and result from a competition between various energy terms, which can be described analytically within a continuum approximation. (Abstract shortened by UMI.)

Yoon, Mina

468

Amorphous silicon exhibits a glass transition.  

PubMed

Amorphous silicon is a semiconductor with a lower density than the metallic silicon liquid. It is widely believed that the amorphous-liquid transition is a first-order melting transition. In contrast to this, recent computer simulations and the experimental observation of pressure-induced amorphization of nanoporous silicon have revived the idea of an underlying liquid-liquid phase transition implying the existence of a low-density liquid and its glass transition to the amorphous solid. Here we demonstrate that during irradiation with high-energy heavy ions amorphous silicon deforms plastically in the same way as conventional glasses. This behaviour provides experimental evidence for the existence of the low-density liquid. The glass transition temperature for a timescale of 10 picoseconds is estimated to be about 1,000 K. Our results support the idea of liquid polymorphism as a general phenomenon in tetrahedral networks. PMID:15502833

Hedler, André; Klaumünzer, Siegfried Ludwig; Wesch, Werner

2004-10-24

469

Vibrational overtone stretching transitions in sarin  

NASA Astrophysics Data System (ADS)

The CH stretching overtone transitions of the nerve agent sarin (O-isopropyl methylphosphonofluoridate) are of interest to the standoff detection of chemical warfare agents, as many of these transitions occur near regions where small, efficient, portable diode lasers (originally developed for use in the telecommunications industry) operate. However, the interpretation of experimental vibrational overtone spectra is often difficult, and the computational simulation of overtone transitions in a molecule is challenging. Presented herein are the simulated CH overtone stretching transitions in sarin. Spectral regions are simulated from overtone transition energies and intensities, both of which are calculated within the harmonically coupled anharmonic oscillator (HCAO) model. Data for HCAO calculations are obtained from ab initio calculations, without any recourse to experimental data.

Petryk, Michael W. P.

2006-10-01

470

Revisiting the Flocking Transition Using Active Spins  

NASA Astrophysics Data System (ADS)

We consider an active Ising model in which spins both diffuse and align on lattice in one and two dimensions. The diffusion is biased so that plus or minus spins hop preferably to the left or to the right, which generates a flocking transition at low temperature and high density. We construct a coarse-grained description of the model that predicts this transition to be a first-order liquid-gas transition in the temperature-density ensemble, with a critical density sent to infinity. In this first-order phase transition, the magnetization is proportional to the liquid fraction and thus varies continuously throughout the phase diagram. Using microscopic simulations, we show that this theoretical prediction holds in 2D whereas the fluctuations alter the transition in 1D, preventing, for instance, any spontaneous symmetry breaking.

Solon, A. P.; Tailleur, J.

2013-08-01

471

Exoplanet Transit Search at Dome C  

NASA Astrophysics Data System (ADS)

We study the potential impact of a photometric search for transiting exoplanets from Dome C. In the past year, four new transiting exoplanets have been found by ground-based surveys, including three detected by our follow-up of OGLE transit candidates with FLAMES/UVES on the VLT. Based on the experience of this survey, we have built a simulation to predict the expected number of transiting exoplanet detections from photometric searches. We apply these simulations to a possible survey based at Concordia. We find that the Antarctica location solves the two main limitations of ground-based transit surveys: the diurnal-cycle time sampling, and the hour-timescale systematic photometric variations. The expected numbers of detections are much larger than for other ground-based surveys. They show the high potential of such projects at Dome C, even with a small telescope.

Pont, F.; Bouchy, F.

472

Magnetic phase transitions in layered intermetallic compounds  

NASA Astrophysics Data System (ADS)

Magnetic, magnetoelastic, and magnetotransport properties have been studied for the RMn2Si2 and RMn6Sn6 (R is a rare earth metal) intermetallic compounds with natural layered structure. The compounds exhibit wide variety of magnetic structures and magnetic phase transitions. Substitution of different R atoms allows us to modify the interatomic distances and interlayer exchange interactions thus providing the transition from antiferromagnetic to ferromagnetic state. Near the boundary of this transition the magnetic structures are very sensitive to the external field, temperature and pressure. The field-induced transitions are accompanied by considerable change in the sample size and resistivity. It has been shown that various magnetic structures and magnetic phase transitions observed in the layered compounds arise as a result of competition of the Mn-Mn and Mn-R exchange interactions.

Mushnikov, N. V.; Gerasimov, E. G.; Rosenfeld, E. V.; Terent'ev, P. B.; Gaviko, V. S.

2012-10-01

473

Electroweak phase transition in ultraminimal technicolor  

SciTech Connect

We unveil the temperature-dependent electroweak phase transition in new extensions of the standard model in which the electroweak symmetry is spontaneously broken via strongly coupled, nearly conformal dynamics achieved by the means of multiple matter representations. In particular, we focus on the low energy effective theory introduced to describe ultra minimal walking technicolor at the phase transition. Using the one-loop effective potential with ring improvement, we identify regions of parameter space, which yield a strong first-order transition. A striking feature of the model is the existence of a second phase transition associated to the electroweak-singlet sector. The interplay between these two transitions leads to an extremely rich phase diagram.

Jaervinen, Matti; Sannino, Francesco [University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Ryttov, Thomas A. [Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen O (Denmark)

2009-05-01

474

Dynamo transition under Taylor-Green forcing  

NASA Astrophysics Data System (ADS)

We perform pseudo-spectral simulations of the Taylor-Green dynamo for magnetic Prandtl number of one and produce a bifurcation diagram near the dynamo transition. We observe that the primary dynamo transition is through a supercritical pitchfork bifurcation. We show that the planar magnetic structures near the dynamo transition are due to the emergence of the B(0, 0, 1) and B(0, 0, 2) magnetic Fourier modes, which are born as a result of triadic interactions. Near the transition, the kinetic energy (Eu) and the magnetic energy (Eb) grow linearly with the forcing amplitude F0 with the same slope. The ratio Eb/Eu for F0=[0, 40] ranges from 0 to 3. Beyond the transition, the numerical simulations reveal complex dynamo states with windows of constant, periodic, quasiperiodic, and chaotic magnetic field configurations.

Yadav, R.; Chandra, M.; Verma, M. K.; Paul, S.; Wahi, P.

2010-09-01

475

Spin transition in Fe-bearing perovskite  

NASA Astrophysics Data System (ADS)

The Earth's lower mantle, which is the largest part by volume of our planet, is mainly formed of Fe- and Al- bearing MgSiO3 perovskite (pv). The Fe-component exhibits a spin transition under pressure whose nature and outcome is still a matter of debate. Here we are using lattice dynamical calculations based on density functional perturbation theory to disentangle a part of its complex phase diagram and the spin behavior. To do this we investigate the dynamic stability of Pbnm FeSiO3 pv and show the existence of unstable phonon modes. We track the eigen-displacements of the phonons modes to find low-spin and intermediate spin states. On solid-state physical basis we explore a set of hypothetical structures with various spin configurations and considerably lower enthalpy than the parent orthorhombic Pbnm structure. We show that the spin evolves along a high-spin to mixed high- and intermediate spin to low-spin transition sequence. Based on numerical results from first-principles calculations, we show that the spin transitions can be observed experimentally in X-ray diffraction and Raman measurements. New diffraction peaks form during the spin transition, which are explained by the associated symmetry breaking. Certain observable Raman peaks exhibit a shift at the transition; the Grueneisen parameters of certain few modes are affected by the transition. The spin transition affects the seismic anisotropy pattern of perovskite. However it does not affect the elastic moduli and the bulk seismic wave velocities are weakly affected by the spin transition. [1]. These signatures are detectable by seismic observations and they need to be taken into account in tomographic studies of the Earth's lower mantle. Finally we show that the iron spin transition develops also in compressed glasses, but over a broad pressure range. More interestingly this transition can pass by an intermediate spin state configuration. [1] Caracas, Mainprice, and Thomas (2010) Geophys. Res. Lett. 37, L13309.

Caracas, R.

2012-04-01

476

Exoplanet Transit Database. Reduction and processing of the photometric data of exoplanet transits  

NASA Astrophysics Data System (ADS)

We demonstrate the newly developed resource for exoplanet researchers - The Exoplanet Transit Database. This database is designed to be a web application and it is open for any exoplanet observer. It came on-line in September 2008. The ETD consists of three individual sections. One serves for predictions of the transits, the second one for processing and uploading new data from the observers. We use a simple analytical model of the transit to calculate the central time of transit, its duration and the depth of the transit. These values are then plotted into the observed-computed diagrams (O-C), that represent the last part of the application.

Poddaný, Stanislav; Brát, Luboš; Pejcha, Ond?ej

2010-03-01

477

Universal transition state scaling relations for (de)hydrogenation over transition metals.  

PubMed

We analyse the transition state energies for 249 hydrogenation/dehydrogenation reactions of atoms and simple molecules over close-packed and stepped surfaces and nanoparticles of transition metals using Density Functional Theory. Linear energy scaling relations are observed for the transition state structures leading to transition state scaling relations for all the investigated reactions. With a suitable choice of reference systems the transition state scaling relations form a universality class that can be approximated with one single linear relation describing the entire range of reactions over all types of surfaces and nanoclusters. PMID:21996683

Wang, S; Petzold, V; Tripkovic, V; Kleis, J; Howalt, J G; Skúlason, E; Fernández, E M; Hvolbæk, B; Jones, G; Toftelund, A; Falsig, H; Björketun, M; Studt, F; Abild-Pedersen, F; Rossmeisl, J; Nørskov, J K; Bligaard, T

2011-10-14

478

Los Angeles Mass Transit Strike  

NSDL National Science Digital Library

Beginning on Saturday, September 16, 2000, the drivers of the Los Angeles city buses launched a strike, stopping the 2,000 buses, subway, and rail lines that cover the 1,400 square miles of Los Angeles County, and stranding nearly half a million bus riders. The 4,300 members of the United Transportation Union (UTU) are on strike over wages and overtime. The Mass Transit Authority (MTA) of Los Angeles will face a $438 million deficit by 2010 if it does not manage to cut costs. Rather than raise fares, the MTA suggested cutting the cost of drivers's overtime pay by fifteen percent over the next three years, for a saving of $23 million. To do this, the MTA proposed that 400 drivers accept a four-day-a-week work schedule, in which they would be on duty twelve hours a day, but would only be paid for ten hours. Overtime would start only after twelve hours. The strike has already proven itself difficult for the people of Los Angeles. Traffic increased nearly five percent, and those Los Angelenos who depend on public transportation to get to work and school, have been forced to walk, carpool, or ride bikes. According to the MTA, 68 percent of MTA riders have household incomes under $15,000 a year. Talks between the UTU and the MTA were to have resumed on Tuesday morning.

479

Lunar transit telescope lander design  

NASA Astrophysics Data System (ADS)

The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

Omar, Husam A.

480

Lunar transit telescope lander design  

NASA Astrophysics Data System (ADS)

The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

Omar, Husam A.

1991-10-01

481

Observability transitions in correlated networks  

NASA Astrophysics Data System (ADS)

Yang, Wang, and Motter [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.109.258701 109, 258701 (2012)] analyzed a model for network observability transitions in which a sensor placed on a node makes the node and the adjacent nodes observable. The size of the connected components comprising the observable nodes is a major concern of the model. We analyze this model in random heterogeneous networks with degree correlation. With numerical simulations and analytical arguments based on generating functions, we find that negative degree correlation makes networks more observable. This result holds true both when the sensors are placed on nodes one by one in a random order and when hubs preferentially receive the sensors. Finally, we numerically optimize networks with a fixed degree sequence with respect to the size of the largest observable component. Optimized networks have negative degree correlation induced by the resulting hub-repulsive structure; the largest hubs are rarely connected to each other, in contrast to the rich-club phenomenon of networks.

Hasegawa, Takehisa; Takaguchi, Taro; Masuda, Naoki

2013-10-01

482

QCD Phase Transitions, Volume 15  

SciTech Connect

The title of the workshop, ''The QCD Phase Transitions'', in fact happened to be too narrow for its real contents. It would be more accurate to say that it was devoted to different phases of QCD and QCD-related gauge theories, with strong emphasis on discussion of the underlying non-perturbative mechanisms which manifest themselves as all those phases. Before we go to specifics, let us emphasize one important aspect of the present status of non-perturbative Quantum Field Theory in general. It remains true that its studies do not get attention proportional to the intellectual challenge they deserve, and that the theorists working on it remain very fragmented. The efforts to create Theory of Everything including Quantum Gravity have attracted the lion share of attention and young talent. Nevertheless, in the last few years there was also a tremendous progress and even some shift of attention toward emphasis on the unity of non-perturbative phenomena. For example, we have seen some efforts to connect the lessons from recent progress in Supersymmetric theories with that in QCD, as derived from phenomenology and lattice. Another example is Maldacena conjecture and related development, which connect three things together, string theory, super-gravity and the (N=4) supersymmetric gauge theory. Although the progress mentioned is remarkable by itself, if we would listen to each other more we may have chance to strengthen the field and reach better understanding of the spectacular non-perturbative physics.

Schaefer, T.; Shuryak, E.

1999-03-20

483

New signatures of phase transitional behavior in nuclei  

SciTech Connect

The phase/shape transitional behavior of different observables is discussed, with emphasis on the 2{sub {gamma}}{sup +}{yields}0{sub 2}{sup +} transition rate. The existing data on transitional Sm isotopes show that the vibrator-rotor shape transition behaves as a critical phase transition despite the finite-body nature of the nuclear environment.

Zamfir, N. V. [WNSL Yale University, New Haven, Connecticut 06520 (United States); Clark University, Worcester, Massachusetts 01610 (United States); Institute of Atomic Physics, Bucharest (Romania); Casten, R. F.; Kruecken, R.; Beausang, C. W.; Cooper, J. R.; Liu Benyuan; Novak, J. R. [WNSL Yale University, New Haven, Connecticut 06520 (United States); Cata-Danil, G. [WNSL Yale University, New Haven, Connecticut 06520 (United States); Institute of Atomic Physics, Bucharest (Romania); Barton, C. J. [Clark University, Worcester, Massachusetts 01610 (United States)

1998-12-21

484

Structural changes concurrent with ferromagnetic transition  

NASA Astrophysics Data System (ADS)

Ferromagnetic transition has generally been considered to involve only an ordering of magnetic moment with no change in the host crystal structure or symmetry, as evidenced by a wealth of crystal structure data from conventional X-ray diffractometry (XRD). However, the existence of magnetostriction in all known ferromagnetic systems indicates that the magnetic moment is coupled to the crystal lattice; hence there is a possibility that magnetic ordering may cause a change in crystal structure. With the development of high-resolution synchrotron XRD, more and more magnetic transitions have been found to be accompanied by simultaneous structural changes. In this article, we review our recent progress in understanding the structural change at a ferromagnetic transition, including synchrotron XRD evidence of structural changes at the ferromagnetic transition, a phenomenological theory of crystal structure changes accompanying ferromagnetic transitions, new insight into magnetic morphotropic phase boundaries (MPB) and so on. Two intriguing implications of non-centric symmetry in the ferromagnetic phase and the first-order nature of ferromagnetic transition are also discussed here. In short, this review is intended to give a self-consistent and logical account of structural change occurring simultaneously with a ferromagnetic transition, which may provide new insight for developing highly magneto-responsive materials.

Yang, Sen; Bao, Hui-Xin; Zhou, Chao; Wang, Yu; Ren, Xiao-Bing; Song, Xiao-Ping; Yoshitaka, Matsushita; Yoshio, Katsuya; Masahiko, Tanaka; Keisuke, Kobayashi

2013-04-01

485

Quantitative measurement of feline colonic transit  

SciTech Connect

Colonic transit scintigraphy, a method for quantitatively evaluating the movement of the fecal stream in vivo, was employed to evaluate colonic transit in the cat. Scintigraphy was performed in duplicate in five cats and repeated four times in one cat. After instillation of an 111In marker into the cecum through a surgically implanted silicone cecostomy tube, colonic movement of the instillate was quantitated for 24 h using gamma scintigraphy. Antegrade and retrograde motion of radionuclide was observed. The cecum and ascending colon emptied rapidly, with a half-emptying time of 1.68 +/- 0.56 h (mean +/- SE). After 24 h, 25.1 +/- 5.2% of the activity remained in the transverse colon. The progression of the geometric center was initially rapid, followed later by a delayed phase. Geometric center reproducibility was found to be high when analyzed using simple linear regression (slope = 0.92; r = 0.73; P less than 0.01). Atropine (0.1 mg/kg im) was found to delay cecum and ascending colon emptying and delay progression of the geometric center. These results demonstrate both 1) the ability of colonic transit scintigraphy to detect changes in transit induced by pharmacological manipulation and 2) the fact that muscarinic blockade inhibits antegrade transit of the fecal stream. We conclude that feline colonic transit may be studied in a quantitative and reproducible manner with colonic transit scintigraphy.

Krevsky, B.; Somers, M.B.; Maurer, A.H.; Malmud, L.S.; Knight, L.C.; Fisher, R.S.

1988-10-01

486

Shedding light on the mitochondrial permeability transition.  

PubMed

The mitochondrial permeability transition is an increase of permeability of the inner mitochondrial membrane to ions and solutes with an exclusion size of about 1500Da. It is generally accepted that the permeability transition is due to opening of a high-conductance channel, the permeability transition pore. Although the molecular nature of the permeability transition pore remains undefined, a great deal is known about its regulation and role in pathophysiology. This review specifically covers the characterization of the permeability transition pore by chemical modification of specific residues through photoirradiation of mitochondria after treatment with porphyrins. The review also illustrates the basic principles of the photodynamic effect and the mechanisms of phototoxicity and discusses the unique properties of singlet oxygen generated by specific porphyrins in discrete mitochondrial domains. These experiments provided remarkable information on the role, interactions and topology of His and Cys residues in permeability transition pore modulation and defined an important role for the outer membrane 18kDa translocator protein (formerly known as the peripheral benzodiazepine receptor) in regulation of the permeability transition. PMID:21377443

Ricchelli, Fernanda; Sileikyt?, Justina; Bernardi, Paolo

2011-03-04

487

Shape phase transitions and critical points  

SciTech Connect

We investigate different aspects connected with shape phase transitions in nuclei and the possible occurrence of dynamical symmetries at the critical points. We discuss in particular the behaviour of the neighbour odd nuclei at the vicinity of the critical points in the even nuclei. We consider both the case of the transition from the vibrational behaviour to the gamma-unstable deformation (characterized within the collective Bohr hamiltonian by the E(5) critical point symmetry) and the case of the transition from the vibrational behaviour to the stable axial deformation (characterized by the X(5) symmetry). The odd particle is assumed to be moving in the three single particle orbitals j = 1/2,3/2,5/2, a set of orbitals that is known to lead to possible supersymmetric cases. The coupling of the odd particle to the Bohr hamiltonian does lead in fact in the former case at the critical point to the E(5/12) boson-fermion dynamical symmetry. An alternative approach to the two shape transitions is based on the Interacting Boson Fermion Model. In this case suitably parametrized boson-fermion hamiltonians can describe the evolution of the odd system along the shape transitions. At the critical points both energy spectra and electromagnetic transitions were found to display characteristic patterns similar to those displayed by the even nuclei at the corresponding critical point. The behaviour of the odd nuclei can therefore be seen as necessary complementary signatures of the occurrence of the phase transitions.

Alonso, C. E.; Arias, J. M. [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Fisica Universidad de Sevilla, Apartado 1065, 41080 Sevilla (Spain); Fortunato, L.; Vitturi, A. [Dipartimento di Fisica Galileo Galilei and INFN, Via Marzolo 8, 35131 Padova (Italy)

2009-05-04

488

Natural Transition in Plane Poiseuille Flow  

NASA Astrophysics Data System (ADS)

We present numerical and theoretical results on the natural transition in a plane Poiseuille flow. The natural transition is often studied in boundary layers, but the analysis in a parallel flow allows the use of the Reynolds number as a control parameter. The results indicated that the classical scenarios described in the literature play a role in natural transition and can lead to turbulent spots. In natural transition the wave systems are modulated in streamwise and spanwise directions and cause premature nonlinearity [1]. Spikes and turbulent spots are often present in natural transition, but the classical routes, namely, K-type and H-type instabilities and the oblique transition, have not been linked to these phenomena. Therefore, many questions remain regarding the relevance of these studies to natural transition. For instance, it is unknown whether such classical routes actually occur in natural transition, whether they occur simultaneously or interact, whether there is a dominant mechanism under some circumstances, etc. Such questions motivated the present work. Numerical simulation of the incompressible three-dimensional Navier-Stokes equations in a vorticity velocity formulation was performed using high accurate numerical schemes. Owing to the complexity of the natural transition, the streamwise modulation was initially not considered. Therefore, only the three dimensionality was studied yielding spanwise modulated wavetrains. Two cases were judiciously selected at Re = 8000. One case was located near the first branch of the two-dimensional stability diagram where the linear process is dominated by three-dimensional Tollmien-Schlichting (TS) waves. The other case was located far from the first branch where the linear process is dominated by a two-dimensional TS waves. Preliminary results can be found in [2]. Similar studies, but for boundary layers, can be found in [3].

Silva, H. G.; Germanos, R. A. C.; Medeiros, M. A. F.

489

Declarative Memory, Awareness, and Transitive Inference  

PubMed Central

A characteristic usually attributed to declarative memory is that what is learned is accessible to awareness. Recently, the relationship between awareness and declarative (hippocampus-dependent) memory has been questioned on the basis of findings from transitive inference tasks. In transitive inference, participants are first trained on overlapping pairs of items (e.g., A+B?, B+C?, C+D?, and D+E?, where + and ? indicate correct and incorrect choices). Later, participants who choose B over D when presented with the novel pair BD are said to demonstrate transitive inference. The ability to exhibit transitive inference is thought to depend on the fact that participants have represented the stimulus elements hierarchically (i.e., A>B>C>D>E). We found that performance on five-item and six-item transitive inference tasks was closely related to awareness of the hierarchical relationship among the elements of the training pairs. Participants who were aware of the hierarchy performed near 100% correct on all tests of transitivity, but participants who were unaware of the hierarchy performed poorly (e.g., on transitive pair BD in the five-item problem; on transitive pairs BD, BE, and CE in the six-item problem). When the five-item task was administered to memory-impaired patients with damage thought to be limited to the hippocampal region, the patients were impaired at learning the training pairs. All patients were unaware of the hierarchy and, like unaware controls, performed poorly on the BD pair. The findings indicate that awareness is critical for robust performance on tests of transitive inference and support the view that awareness of what is learned is a fundamental characteristic of declarative memory.

Smith, Christine; Squire, Larry R.

2006-01-01

490

Phase transitions in phosphatidylcholine multibilayers  

PubMed Central

The 2H NMR spectrum of a multilamellar dispersion of 1-myristoyl-2-[14,14,14-2H3]myristoyl-sn-glycero-3-phosphocholine with 1 mol% cholesterol in excess water has been recorded at temperatures between -15°C and 36°C. Motionally averaged quadrupole coupling constants ??Q? and motionally induced asymmetry parameters ? are obtained by spectral analysis. Values of these quantities indicate that, at temperatures below -4°C, any rotational motion of the molecules about their molecular long axis is slow on the NMR time scale. At temperatures immediately above the pretransition these same parameters show that a fast-rotational motion is occurring about the molecular long axis. This rotational motion is hindered in that the molecules flip about a twofold symmetry axis. Between -4°C and the pretransition, spectra appear as the superposition of two powder patterns, one corresponding to the pattern observed below -4°C and the other to the pattern above the pretransition. The relative contribution of the latter increases with temperature until the pretransition is reached. These data have been interpreted in two ways: either the sample between -4°C and the pretransition contains two populations of rapidly and slowly rotating molecules, or there is only a single population of molecules undergoing a 180° flipping motion on the time scale of the NMR measurement. The latter interpretation is more consistent with other experimental findings. At the temperature of the main transition the hydrocarbon chains melt. In the absence of cholesterol, spectra are more complex in that the line shape is reproduced by the superposition of three spectral powder patterns between -4°C and the pretransition and by the superposition of two spectral patterns above the pretransition. It is postulated that these two patterns observed above the pretransition are in direct correspondence to the two ripple structures observed by freeze-fracture electron microscopy in the absence of cholesterol.

Westerman, Philip W.; Vaz, Maria Joao; Strenk, Lawrence M.; Doane, J. William

1982-01-01

491

Phase transitions in physiologic coupling  

PubMed Central

Integrated physiological systems, such as the cardiac and the respiratory system, exhibit complex dynamics that are further influenced by intrinsic feedback mechanisms controlling their interaction. To probe how the cardiac and the respiratory system adjust their rhythms, despite continuous fluctuations in their dynamics, we study the phase synchronization of heartbeat intervals and respiratory cycles. The nature of this interaction, its physiological and clinical relevance, and its relation to mechanisms of neural control is not well understood. We investigate whether and how cardiorespiratory phase synchronization (CRPS) responds to changes in physiological states and conditions. We find that the degree of CRPS in healthy subjects dramatically changes with sleep-stage transitions and exhibits a pronounced stratification pattern with a 400% increase from rapid eye movement sleep and wake, to light and deep sleep, indicating that sympatho-vagal balance strongly influences CRPS. For elderly subjects, we find that the overall degree of CRPS is reduced by approximately 40%, which has important clinical implications. However, the sleep-stage stratification pattern we uncover in CRPS does not break down with advanced age, and surprisingly, remains stable across subjects. Our results show that the difference in CRPS between sleep stages exceeds the difference between young and elderly, suggesting that sleep regulation has a significantly stronger effect on cardiorespiratory coupling than healthy aging. We demonstrate that CRPS and the traditionally studied respiratory sinus arrhythmia represent different aspects of the cardiorespiratory interaction, and that key physiologic variables, related to regulatory mechanisms of the cardiac and respiratory systems, which influence respiratory sinus arrhythmia, do not affect CRPS.

Bartsch, Ronny P.; Schumann, Aicko Y.; Kantelhardt, Jan W.; Penzel, Thomas; Ivanov, Plamen Ch.

2012-01-01

492

Transition crossing simulation at the Fermilab Booster  

SciTech Connect

The demand in high intensity and low emittance of the beam extracted from the Booster requires a better control over the momentum spread growth and bunch length shortening at transition crossing, in order to prevent beam loss and coupled bunch instability. Since the transition crossing involves both longitudinal and transverse dynamics, the recently modified 3-D STRUCT code provides an opportunity to numerically investigate the different transition crossing schemes in the machine environment, and apply the results of simulation to minimize the beam loss and emittance growth operationally.

Yang, X.; Drozhdin, A.I.; Pellico, W.; /Fermilab

2007-06-01

493

Spatially resolved transitions to autoionizing states  

SciTech Connect

We have observed transitions to autoionizing states in Mg using two short optical pulses. Mg atoms are initially prepared in a high lying Rydberg wave packet with the first ps laser. A second ps laser is then used to excite the inner electron, producing an autoionizing state. The dependence of the transition probability on the delay between the two lasers shows that when the second laser is tuned away from the ionic resonance, the inner electron can make a transition only when the Rydberg wave packet is near the core.

Story, J.G.; Duncan, D.I.; Gallagher, T.F. (Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States))

1993-11-22

494

Multiple dynamic transitions in nonequilibrium work fluctuations.  

PubMed

The time-dependent work probability distribution function P(W) is investigated analytically for a diffusing particle trapped by an anisotropic harmonic potential and driven by a nonconservative drift force in two dimensions. We find that the exponential tail shape of P(W) characterizing rare-event probabilities undergoes a sequence of dynamic transitions in time. These remarkable locking-unlocking type transitions result from an intricate interplay between a rotational mode induced by the nonconservative force and an anisotropic decaying mode due to the conservative attractive force. We expect that most of the high-dimensional dynamical systems should exhibit similar multiple dynamic transitions. PMID:24116762

Noh, Jae Dong; Kwon, Chulan; Park, Hyunggyu

2013-09-24

495

Excitation Chains at the Glass Transition  

SciTech Connect

The excitation-chain theory of the glass transition, proposed in an earlier publication, predicts diverging, super-Arrhenius relaxation times and, via a similarly diverging length scale, suggests a way of understanding the relations between dynamic and thermodynamic properties of glass-forming liquids. I argue here that critically large excitation chains play a role roughly analogous to that played by critical clusters in the droplet model of vapor condensation. Unlike a first-order condensation point in a vapor, the glass transition is not a conventional phase transformation, and may not be a thermodynamic transition at all.

Langer, J. S. [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States)

2006-09-15

496

YETI - search for young transiting planets  

NASA Astrophysics Data System (ADS)

We present our search for young transiting planets at ages of 2 to 20 Myr. Towards this goal, we monitor a number of young open clusters with the YETI network. YETI consists of 0.4-2 m-sized telescopes at different longitudes that observe continuously over timescales much longer than a night. In our first cluster Trumpler 37 we found more than 350 variable stars. Also two transiting candidates were found so far, for which follow-up is partly done. The first candidate turned out to be an eclipsing binary with an M-type companion. We describe the research done on these two transiting candidates.

Errmann, Ronny; Neuhäuser, Ralph; Torres, Guillermo; Terada, Hiroshi; Kellerer, Aglae; Maciejewski, Gracjan; Seeliger, Martin

2013-04-01

497

The Asiago Extrasolar Planet Transit Search  

NASA Astrophysics Data System (ADS)

RATS is an Italian project devoted to Hot Jupiter search with the transit method. A planet transiting in front of a host star can be mimed by several, and well defined, astrophysical phenomena (Brown, 2003). In order to recognize these false alarms we can utilize a preventive strategy to limit false alarm rates and a spectroscopic follow up to refuse no transit candidates. As preventive strategy it is important to develop an accurate target field selection, with well defined requisites, in order to maximize the solar type star numbers and to minimize the risk of possible astrophysical false alarms.

Claudi, R. U.; Cancian, M.; Barbieri, M.; Gratton, R.; Desidera, S.; Montalto, M.; Piotto, G. P.; Scuderi, S.

2006-08-01

498

Thermodynamic model of nonequilibrium phase transitions.  

PubMed

Within the scope of a thermodynamic description using the maximum entropy production principle, transitions from one nonequilibrium (kinetic) regime to another are considered. It is shown that in the case when power-law dependencies of thermodynamic flux on force are similar for two regimes, only a transition accompanied by a positive jump of thermodynamic flux is possible between them. It is found that the difference in powers of the dependencies of thermodynamic fluxes on forces results in a number of interesting nonequilibrium transitions between kinetic regimes, including the reentrant one with a negative jump of thermodynamic flux. PMID:21867119

Martyushev, L M; Konovalov, M S

2011-07-11

499

Dynamics of Layering Transitions in Confined Liquids  

SciTech Connect

Multiple beam interferometry and video microscopy were used to investigate the layering transition of thin liquid films of 1-undecanol confined between atomically smooth mica surfaces. The expulsion of a molecularly thin lubricant layer was followed directly in two dimensions. Overall, the dynamics of the transition follows theoretical predictions based on two-dimensional hydrodynamics. Frequently, pockets of liquid remain trapped inside the contact area at the end of the transition. The trapped pockets undergo shape transformations to minimize elastic and interfacial energy. (c) 2000 The American Physical Society.

Mugele, F.; Salmeron, M.

2000-06-19

500

Mott transition near the ferromagnetic state  

NASA Astrophysics Data System (ADS)

We consider the Hubbard model, either in a magnetic field (model I) or with a general nearest-neighbor interaction (model II). For these models we determine criteria for the instability of the fully polarized ferromagnet. We show that the ground state below the instability contains an exactly soluble Mott transition. The transition occurs at a critical interaction Uc, at which perturbation theory breaks down. Extended metallic states are found for UUc. Details of the transition strongly depend on dimension.

van Dongen, P. G.; Janiš, V.

1994-05-01