These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Investigation of low-Z Coster-Kronig transitions by means of Auger and photoelectron spectroscopy  

NASA Technical Reports Server (NTRS)

Experimental intensity ratios of Auger transitions for Co, Ni, Cu, and Zn as well as the relative L sub 2 and L sub 3 level widths of Cu and Zn, derived from their photoelectron spectra, are presented. Evidence is presented that a great deal of vacancy reorganization took place following photoionization and prior to Auger emission. These reorganizations are assumed to be due to Coster-Kronig transitions f sub 23. These results are compared with theoretical calculations and agree with predicted discontinuity at Z = 30 where f sub 23 transitions become energetically impossible.

Yin, L. I.; Tsang, T.; Adler, I.

1972-01-01

2

Auger and Coster-Kronig radial matrix elements for atomic numbers 6 le Z le 92  

SciTech Connect

Coulomb radial matrix elements for Auger and Coster-Kronig transitions to K-, L{sub 1}-, L{sub 2}-, and L{sub 3}-shell vacancies in singly ionized atoms have been calculated with relativistic Dirac-Hartree-Slater wave functions. Results are tabulated for atomic numbers Z = 6-87 for the K shell and Z = 12-92 for the L subshells. These matrix elements can be used to calculate approximate Auger rates in multiply ionized atoms; the matrix elements are expected to be very useful for the computation of Auger rates in molecules and can be applied in computations of valence-band Auger lineshapes in solids.

Chen, Mau Hsiung (Lawrence Livermore National Laboratory, CA (USA)); Larkins, F.P. (Univ. of Tasmania, Hobart (Australia)); Crasemann, B. (Univ. of Oregon, Eugene (USA))

1990-05-01

3

Theoretical L-shell Coster-Kronig energies 11 or equal to z or equal to 103  

NASA Technical Reports Server (NTRS)

Relativistic relaxed-orbital calculations of L-shell Coster-Kronig transition energies have been performed for all possible transitions in atoms with atomic numbers. Hartree-Fock-Slater wave functions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first-order approximation to the local approximation was thus included. Quantum-electrodynamic corrections were made. Each transition energy was computed as the difference between results of separate self-consistent-field calculations for the initial, singly ionized state and the final two-hole state. The following quantities are listed: total transition energy, 'electric' (Dirac-Hartree-Fock-Slater) contribution, magnetic and retardation contributions, and contributions due to vacuum polarization and self energy.

Chen, M. H.; Crasemann, B.; Huang, K. N.; Aoyagi, M.; Mark, H.

1976-01-01

4

Measurement of the O2O3O4 and O3O4O5 super Coster-Kronig rates in tungsten via asymmetric diffraction spectrometry  

NASA Astrophysics Data System (ADS)

The tungsten L? transitions between 11 and 12 keV and K? transitions from 57 to 60 keV were produced by a laboratory electron-bombarded x-ray source and simultaneously recorded with high resolution by using multiple diffraction planes of the same quartz crystal operating in Cauchois transmission geometry. The W K? transitions were dispersed by the (5?0?2) planes, which were perpendicular to the crystal entrance surface, and by the (6?0?2), (7?0?2), and (8?0?4) planes which were rotated with respect to the (5?0?2) planes by angles up to 4.80°. The W L? transitions were dispersed by the (2?0?1) planes rotated from the (5?0?2) planes by 4.01°. The spectra from the five planes were simultaneously recorded on image plate detectors, and spectra were also recorded by scanning solid-state electronic detectors with narrow slits across the spectral lines. The metrology of the L and K shell spectra diffracted from multiple quartz planes enabled the detailed analysis of the detector spatial resolution and accurate measurement of the instrumental broadening produced by the various quartz diffraction planes. The W L? spectra had the highest instrumental resolving power, 1800, permitting for the first time the resolution of the blended L?4? (L1O2) and L?4 (L1O3) transitions. After subtracting the instrumental and detector contributions to the line widths, the remainder was assigned to the natural line widths. The measured widths of the O2 and O3 levels were 2.9 eV and 1.9 eV, respectively, and based on atomic code calculations these widths are attributed to the O2O3O4 and O3O4O5 super Coster-Kronig processes. This work demonstrates the ability to simultaneously record high resolution (<1 eV) L and K spectra to determine the line shapes of the heavy elements (e.g. W through Am) by using multiple planes of a single quartz crystal and to accurately measure the non-radiative super Coster-Kronig rates which are closely related to the energy level structure of the outer shells of the heavy elements.

Seely, John; Glover, Jack L.; Hudson, Lawrence; Ralchenko, Yuri; Pereira, Nino; Feldman, Uri

2014-06-01

5

Synchrotron-radiation-based determination of Xe L-subshell Coster-Kronig yields: A reexamination via high-resolution x-ray spectroscopy  

SciTech Connect

The xenon L-subshell Coster-Kronig (CK) transition yields were revisited via high-resolution measurements of the Lalpha{sub 1,2} (L{sub 3}-M{sub 4,5}) and Lbeta{sub 1} (L{sub 2}-M{sub 4}) x-ray emission lines. The L x-ray spectra were measured employing a Johansson-type curved crystal spectrometer and energy-tunable synchrotron radiation. The CK yields were derived from the relative L x-ray intensity jumps at the L edges by fitting the fluorescence intensities as a function of the photon energy to the L-subshell photoionization cross sections. The latter were obtained from the measured L-edge photoabsorption spectrum. Values of 0.118+-0.029, 0.383+-0.037, and 0.096+-0.016 were found for the f{sub 23}, f{sub 13}, and f{sub 12} CK yields, respectively. Thanks to high resolution, the L{sub 1} fluorescence yield of 0.059+-0.002 was also determined from intensity ratios of the well-resolved Lbeta{sub 4} (L{sub 1}-M{sub 2}) and Lbeta{sub 1} (L{sub 2}-M{sub 4}) lines.

Cao, W.; Dousse, J.-Cl.; Hoszowska, J. [Department of Physics, University of Fribourg, Ch-1700 Fribourg (Switzerland); Zitnik, M.; Kavcic, M.; Bucar, K. [J. Stefan Institute, SI-1001 Ljubljana (Slovenia)

2010-01-15

6

Synchrotron-radiation-based determination of Xe L-subshell Coster-Kronig yields: A reexamination via high-resolution x-ray spectroscopy  

NASA Astrophysics Data System (ADS)

The xenon L-subshell Coster-Kronig (CK) transition yields were revisited via high-resolution measurements of the L?1,2 (L3-M4,5) and L?1 (L2-M4) x-ray emission lines. The L x-ray spectra were measured employing a Johansson-type curved crystal spectrometer and energy-tunable synchrotron radiation. The CK yields were derived from the relative L x-ray intensity jumps at the L edges by fitting the fluorescence intensities as a function of the photon energy to the L-subshell photoionization cross sections. The latter were obtained from the measured L-edge photoabsorption spectrum. Values of 0.118±0.029, 0.383±0.037, and 0.096±0.016 were found for the f23, f13, and f12 CK yields, respectively. Thanks to high resolution, the L1 fluorescence yield of 0.059±0.002 was also determined from intensity ratios of the well-resolved L?4 (L1-M2) and L?1 (L2-M4) lines.

Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Žitnik, M.; Kav?i?, M.; Bu?ar, K.

2010-01-01

7

Radiationless transitions to atomic M 1,2,3 shells - Results of relativistic theory  

NASA Technical Reports Server (NTRS)

Radiationless transitions filling vacancies in atomic M1, M2, and M3 subshells have been calculated relativistically with Dirac-Hartree-Slater wave functions for ten elements with atomic numbers 67-95. Results are compared with those of nonrelativistic calculations and experiment. Relativistic effects are found to be significant. Limitations of an independent-particle model for the calculation of Coster-Kronig rates are noted.

Chen, M. H.; Crasemann, B.; Mark, H.

1983-01-01

8

L-subshell ionization of Nd, Gd, and Er by 0.40 to 2.00 MeV incident deuterons  

NASA Astrophysics Data System (ADS)

Subshell X-ray production cross sections of Nd, Gd and Er were measured for incident deuterons with energies between 0.40 and 2.00 MeV. These measurements are compared to theoretical X-ray production cross sections (obtained from the theoretical ionization cross sections by the use of theoretical values of fluorescence yields and Coster-Kronig transition probabilities) predicted by the Plane Wave Bom Approximation and Perturbed Stationary State theories (including relativistic and Coulomb deflection effects). No one theory provides a best fit to the experimental data. However, there is a marked improvement in the fit as the Z of the target atom increases.

Rayburn, L. A.; Thompson, B. C.

1987-04-01

9

Effect of vacancy de-excitation parameters on L X-rays of Pb using H + beam  

NASA Astrophysics Data System (ADS)

The collision progression including ionization of an inner-shell by an energetic proton and decay of vacancy is a motivating theme in ion-beam analysis. To explore measured vacancy de-excitation parameters for Pb, intensity ratios are experimentally determined from L X-rays with proton impact in the energy range 225-400 keV. Predictions of UAECPSSR theory are employed for ionization cross-sections. For atomic parameters such as transition rates, fluorescence, Auger and Coster-Kronig (CK) yields, various databases are used. In this paper, significance of these features and current progress are discussed.

Jain, Arvind Kumar; Mohan, Harsh; Sharma, Sunita

2010-06-01

10

Transits  

Microsoft Academic Search

Transits of the planets Mercury and especially Venus have been exciting events in the development of astronomy over the past few hundred years. Just two years ago the first transiting extra-solar planet, HD 209458b, was discovered, and subsequent studies during transit have contributed fundamental new knowledge. From the photometric light curve during transit one obtains a basic confirmation that the

Ronald L. Gilliland

2005-01-01

11

Measurement of angular distribution of fluorescent X-rays and L subshell fluorescence yields in thorium and uranium  

NASA Astrophysics Data System (ADS)

L?,L ?,L ?2,4,L ?1,3 and L ? X-ray production cross-sections and L-subshell fluorescence yields ( ?1 and ?2) in Th and U have been determined at an incident photon energy of 59.5 keV by measuring differential cross-sections with angles changing at intervals of 10° from 40° to 130°. In particular, we have investigated the angular dependence of production cross-sections for the L ?2,4 and L ?1,3 lines which can be obtained with some ease for U and Th in Si(Li) detector. The experimental values of cross-sections were obtained by using the absolute yield of L subshell X-rays emitted from a target of a given element and thickness when bombarded with a known flux of photons of given energy. The theoretical values of the cross-sections were estimated from the theoretical values of subshell photoionization cross-sections, fluorescence yields, Coster-Kronig transition probabilities and relative decay rates. The enhancement effect of the Coster-Kronig transition have been calculated for these elements at the same photon energy. The present experimental results have been compared with theoretical and other experimental values. It has been found that the present experimental results are in good agreement with theoretical and the experimental values of others.

Seven, Sabriye

2004-04-01

12

Development of a coincidence system for the measurement of X-ray emission atomic parameters  

SciTech Connect

Preliminary results obtained in experiments carried out with an x-ray spectrometer built at the Instituto de Fisica for Atomic Physics and environmental sciences studies are presented. The experiments are based on a coincidence method for signals produced by LEGe and Si(Li) detectors. The x-ray fluorescence yields ({omega}{sub Li}) and Coster-Kronig transition probabilities (f{sub ij}) for elements with 55 {<=} Z {<=} 60 are among the quantities of interest. The method is based on the simultaneous detection of K x-rays with the LEGe detector and the L x-rays with the Si(Li) detector. The primary radiation source is an x-ray tube with Rh anode. The system was tested with the coincidence of the L x-rays from Ce with its K line, demonstrating the feasibility of the experiments.

Martinez, Filiberto; Miranda, Javier [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico, D.F (Mexico)

2013-07-03

13

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

14

L?, L?, L? and L? X-ray production cross-sections and yields of some selected elements between caesium and erbium following ionization by 59.54 keV ? rays  

NASA Astrophysics Data System (ADS)

Ll, L?, L? and L? X-ray production cross-sections were measured in elements from Cs to Er following ionization for 59.54 keV ?-rays from an 241Am point source. The measured values are compared with theoretical predictions estimated using subshell photoionization cross-sections, fluorescence yields, Coster-Kronig transition probabilities, K to Li subshell vacancy transfer probabilities and radiative decay rates. Average L-shell fluorescence yields were deduced from present measured total L X-ray production cross-sections, theoretical K and L photoionization cross-sections and K to L vacancy transfer probabilities. The obtained results for L X-ray production cross-sections and average L-shell fluorescence yields are compared with recent experimental values, theoretical predictions, and semiempirical fits.

Durak, Ridvan; Özdemir, Yüksel

2000-02-01

15

Coupling and binding-saturation effects in L -subshell ionization of heavy atoms by 0.3-1.3-MeV/amu Si ions  

NASA Astrophysics Data System (ADS)

The coupling and binding effects have been studied in L -subshell ionization of heavy Au, Bi, Th, and U atoms by an impact of S28iq+ ions in the energy range of 8.5-36.0 MeV. The measured L x-ray spectra were analyzed taking into account the multiple ionization effects in outer M and N shells. The L -subshell ionization cross sections have been obtained from measured x-ray production cross sections using the L -shell fluorescence and Coster-Kronig yields which were modified for a reduced number of electrons and closed Coster-Kronig transitions in the multiply ionized atoms. The results are compared with the available calculations, which are based on the semiclassical approximation (SCA) as well as the plane-wave Born approximation (PWBA). We demonstrate that for silicon ion impact these theoretical approaches have to be modified to include the L -subshell coupling effect using the “coupled subshell model” (CSM) as well as the saturation of the binding effect at the united atom limit. The calculations modified for both effects are in much better agreement with the data. In particular, an order-of-magnitude improvement of agreement between the data and the SCA-CSM calculations including the binding-saturation effect is reported for low-energy Si ions for the L2 -subshell. The results are also compared with the predictions of the PWBA based ECPSSR and ECUSAR theories accounting for the energy-loss (E), Coulomb-deflection (C), and relativistic (R) effects treating the binding effect within the perturbed stationary state (PSS) approximation with correction for the binding-saturation effect introduced to describe the united-atom and separated-atom (USA) limits.

Fija?-Kirejczyk, I.; Jaskó?a, M.; Czarnacki, W.; Korman, A.; Bana?, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Pajek, M.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.; Lapicki, G.

2008-03-01

16

Origin of the satellites L?3, L?4 and L?5 in the elements from 40Zr to 50Sn  

NASA Astrophysics Data System (ADS)

The origin of the L? satellites L?3, L?4 and L?5 have been explained in the elements from 40Zr to 50Sn, on the basis of multiple ionization theory. The energies and intensities of the various transitions corresponding to the L3Mx – MxM4,5 (where x = 1-5) transition array, which may give rise to these satellites, have been calculated theoretically. The energies of the transitions have been calculated using the available Hartree-Fock-Slater data for the energies of K-LM and L-MM Auger transitions. The intensities of the various transitions have been estimated by considering cross sections for L1-L3Mx Coster-Kronig transitions as well as for M-shell shake-off process occurring simultaneous to a L3 hole creation. The total cross sections for initial two-hole states L3Mx have then been distributed statistically amongst the various allowed transitions from these initial states to the final states MxM4,5. By assuming each transition as a Gaussian line, theoretical satellite spectrum has been computed as the sum of these Gaussian curves. The energies of the satellites, as obtained from the theoretical spectrum, have been found to be comparable with the measured energies of the satellites L?3, L?4 and L?5. Consequently, these satellites have been assigned the transitions.

Kendurkar, Renuka; Shrivastava, B. D.

2014-09-01

17

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

SciTech Connect

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-, L{sub 1}-, L{sub 2,3}-, M{sub 1}-, M{sub 2,3}- and M{sub 4,5} 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 Xe{sup 7+}, Xe{sup 8+}, Xe{sup 9+} and Xe{sup 10+} ions, and the charged X{sup 8+} ions are the highest. The main product from the L{sub 1}- shell ionization is found to be Xe{sup 8+}, Xe{sup 9+} ions, while the charged Xe{sup 8+} ions predominate at L{sub 2,3} hole states. The charged Xe{sup 6+}, Xe{sup 7+} and Xe{sup 8+} ions mainly yield from 3s{sub 1/2} and 3p{sub 1/2,3/2} ionization, while Xe in 3d{sub 3/2,5/2} hole states mainly turns into Xe{sup 4+} and Xe{sup 5+} 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. [Applied Sciences Department, College of Technological Studies, P.O. Box 42325, Shuwaikh 70654 (Kuwait)

2010-01-05

18

Origin of the satellite observed on the high energy side of L?2,3 diagram lines  

NASA Astrophysics Data System (ADS)

On the high energy side of the unresolved doublet L?23in the L spectra of some elements, a satellite L?2,3' has been reported in literature, which has been ascribed to the transition L1Mx − MxN2,3, on the basis of energy considerations alone, by earlier workers. In the present work, apart from energy, calculations have also been done for the intensity of the probable transitions which may give rise to the satellite in the elements from 40Zr to 47Ag and from 57La to 63Eu. Firstly, the probability of creation of a single hole K state has been calculated. Double hole state L1Mx is created by Coster-Kronig transitions (K − L1Mx) as well as by shake off process. The probabilities of these two processes have been calculated. The total probability of creation of the double hole state thus obtained has been statistically distributed among the 24 allowed transitions from the set of L1Mx levels. By taking each of the transitions as a Gaussian line, a composite spectrum has been computed. This theoretical spectrum has been compared with the available satellite energy data. The transitions which give rise to this satellite have thus been identified in the elements studied.

Trivedi, Rajeev; Shrivastava, Uma; Shrivastava, B. D.

2014-09-01

19

Polarization of the K?L1 x-ray satellite in copper after 2 MeV proton impact  

NASA Astrophysics Data System (ADS)

The KalphaL1 satellite spectrum of 29Cu was measured with a 5 inch Johansson crystal spectrometer after 2 MeV proton impact. The satellite spectrum was simulated by using Voigt profiles with a Lorentzian width which is obtained from the multiconfiguration Dirac-Fock (MCDF) calculations and convoluted with the Gaussian instrumental response function. A unique assignment of the strongest satellite transitions to visible structures in the experimental spectrum was based on a comparison of the predicted linear polarization of the transitions (using in calculations the intermediate coupling scheme) to their measured values. The simulated spectrum of the satellite transitions was fitted to the experiment. The fitted values of energies and relative intensities of the transitions are close to those obtained from the MCDF calculations. The alignment of the (1s2p)-2 double-vacancy state obtained from the measured polarization of the satellite spectrum is given by Script A20(1P 1) = -0.77(21) and Script A20 (3P) = -0.53(10) (values are not corrected for the Coster-Kronig transition). This is in agreement with the value reported for the KalphaL1 peak of Al.

Stachura, Z.; Vollmer, W.; Fritzsche, S.; Stöhlker, Th; Meierkord, W.; Sulkio-Cleff, B.

2003-04-01

20

Widths of atomic 4s and 4p vacancy states, Z between 46 and 50  

NASA Technical Reports Server (NTRS)

X-ray photoelectron and Auger spectra involving N sub 1, N sub 2, and N sub 3 vacancy states of Pd, Ag, Cd, In, and Sn were measured and compared with results of free-atom calculations. As previously observed in Cu and Zn Auger spectra that involve 3d-band electrons, free-atom characteristics are found, with regard to widths and structure, in the Ag and Cd M sub 4-N sub 4,5 N sub 4,5 and M sub 5-N sub 4,5 N sub 4,5 Auger spectra that arise from transitions of 4d-band electrons. Theoretical N sub 1 widths computed with calculated free-atom Auger energies agree well with measurements. Theory, however, predicts wider N sub 2 than N sub 3 vacancy states (as observed for Xe), while the measured N sub 2 and N sub 3 widths are nearly equal to each other and to the average of the calculated N sub 2 and N sub 3 widths. The calculations are made difficult by the exceedingly short lifetime of some 4 p vacancies and by the extreme sensitivity of super-Coster-Kronig rates, which dominate the deexcitation to the transition energy and to the fine details of the atomic potential.

Chen, M. H.; Crasemann, B.; Yin, L. I.; Tsang, T.; Adler, I.

1976-01-01

21

Widths of atomic 4s and 4p vacancy states, 46 less than or equal to Z less than or equal to 50  

NASA Technical Reports Server (NTRS)

Auger and X-ray photoelectron spectra involving N1, N2, and N3 vacancy states of Pd, Ag, Cd, In, and Sn were measured and compared with results of free atom calculations. As previously observed in Cu and Zn Auger spectra that involve 3d-band electrons, free-atom characteristics with regard to widths and structure were found in the Ag and Cd M4-N4,5N4,5 and M5-N4,5N4,5 Auger spectra that arise from transitions of 4d-band electrons. Theoretical N1 widths computed with calculated free-atom Auger energies agree well with measurements. Theory however predicts wider N2 than N3 vacancy states (as observed for Xe), while the measured N2 and N3 widths are nearly equal to each other and to the average of the calculated N2 and N3 widths. The calculations are made difficult by the exceedingly short lifetime of some 4p vacancies and by the extreme sensitivity of super-Coster-Kronig rates, which dominate the deexcitation, to the transition energy and to the fine details of the atomic potential.

Hsiungchen, M.; Crasemann, B.; Yin, L. I.; Tsang, T.; Adler, I.

1975-01-01

22

Local electronic structure of Mn dopants in ZnO probed by resonant inelastic x-ray scattering  

NASA Astrophysics Data System (ADS)

The electronic structure of Mn dopants in ZnO epitaxial thin films synthesized at different temperatures has been investigated using resonant inelastic x-ray scattering. The resulting Mn L2,3 x-ray emission spectra of Zn0.8Mn0.2O (resonantly excited at L2 and L3 absorption edges) reveal different spectral features depending on the growth temperature of the films. The relative integral intensity ratio of Mn L2 to Mn L3 emission lines is greatly suppressed in the case of nonmagnetic Zn0.8Mn0.2O grown at 700 °C due to L2L3M4,5 Coster-Kronig transitions. The ferromagnetic sample grown at 600 °C exhibits a normal oxide structure. The results suggest that a high growth temperature causes direct Mn-Mn bonds from the segregation of Mn atoms in ZnO. Therefore the disappearance of ferromagnetism in Mn-doped ZnO can be attributed to antiferromagnetic Mn-Mn exchange interactions due to the inhomogeneous local environment around the Mn impurities.

Chang, G. S.; Kurmaev, E. Z.; Jung, S. W.; Kim, H.-J.; Yi, G.-C.; Lee, S.-I.; Yablonskikh, M. V.; Pedersen, T. M.; Moewes, A.; Finkelstein, L. D.

2007-07-01

23

The origin of the resistance change in GeSbTe films  

SciTech Connect

Amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} (a-GST) films were deposited by ion beam sputtering deposition. Extended x-ray absorption fine structure (EXAFS) data confirmed the existence of the Ge-Ge homopolar bonds in the films. Raman spectra also indicated that the Ge tetrahedral coordination in the a-GST film disappeared after an annealing treatment above 220 deg. C. Resonantly excited Ge L{sub 2,3} x-ray emission spectra (which probe occupied Ge 3d4s-electronic states) show that the phase change from the amorphous to crystalline state is accompanied by a reduction in the Ge I(L{sub 2})/I(L{sub 3}) intensity ratio due to a L{sub 2}L{sub 3}N Coster-Kronig transition, indicating that the number of carriers is increased in the Ge 4sp valence state. These findings constitute direct evidence for the contribution of the Ge electronic states to the resistivity change.

Jang, Moon Hyung [Atomic-scale Surface Science Research Institute, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Seung Jong; Park, Sung Jin [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Cho, Mann-Ho [Atomic-scale Surface Science Research Institute, Yonsei University, Seoul 120-749 (Korea, Republic of); Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Kurmaev, E. Z.; Finkelstein, L. D. [Ural Division, Institute of Metal Physics, Russian Academy of Sciences, 620441 Yekaterinburg (Russian Federation); Chang, Gap Soo [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon SK S7N 5E2 (Canada)

2010-10-11

24

Studies on radiative collisional and ultraviolet lasers. Final report, 1 January 1983-31 December 1985  

SciTech Connect

Significant accomplishments of this program include: the first microwave pumping of an excimer laser; the first use of pulsed hollow-cathode technology to produce substantial quantities of core-excited metastable atoms; the use of these metastable atoms to delineate a partial Grotrian diagram for core-excited Na; the proposal of the concept of quasi-metastable quartet levels and the experimental verification of their importance in the column I metals; and the proposal for short-wavelength systems based on super Coster-Kronig transitions. Abstracts: Laser Techniques for Extreme Ultraviolet Spectroscopy; Active Mode Looking of a Microwave-Pumped XeCl Laser; Measurement of Lithium and Sodium Metastable Quartet Atoms in a Hollow-Cathode Discharge; Quasi-Metastable Quartet Levels in Alkalilike Atoms and Ions; Grotrian Diagram of the Quartet System of Na I; Emission at 1091 A in Neutral Core-Excited Cs; Metastability in the Extreme Ultraviolet: Lasers and Spectroscopy; Laser Spectroscopy of Na I Quartets; X-Ray Excitation of Energetic Metastable Levels in Atoms and Ions; Proposal for an Extreme-Ultraviolet Selective Autoionization Laser in Zn III; XUV Emission Spectra of Core-Excited Levels in Sodium and Magnesium; Quasi-Metastable Energy Levels and Applications; Shake-up as a Mechanism for VUV Lasers; and Emission Spectra of Quasi-Metastable Levels of Alkali Atoms.

Harris, S.E.; Young, J.F.

1985-11-01

25

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

26

A new fundamental parameter based calibration procedure for micro X-ray fluorescence spectrometers  

NASA Astrophysics Data System (ADS)

Fundamental parameter based quantification of X-ray fluorescence (XRF) measurement data requires an accurate knowledge of the spectrometer parameters, including the spectral distribution of the excitation radiation. In case of micro-XRF where a polycapillary optic is utilized in the excitation channel this distribution is changed due to the transmission properties of the lens. A new calibration procedure, based on fluorescence data of thin standard samples, was developed to determine the excitation spectrum, i.e., the product of the X-ray tube spectrum and the transmission of the used X-ray optic of a micro-XRF setup. The calibration result was validated by the quantitative analyses of certified multi-element reference standards and shows uncertainties in the order of 2% for main components, 10% for minor elements and 25% for trace elements. The influence of secondary order effects like Coster-Kronig transitions and cascade effects is analyzed and the accuracy of fundamental parameters in common databases is discussed.

Wolff, Timo; Malzer, Wolfgang; Mantouvalou, Ioanna; Hahn, Oliver; Kanngießer, Birgit

2011-02-01

27

Measurements of L X-ray production cross sections, L subshell fluorescence yields and K to L shell vacancy transfer probabilities  

NASA Astrophysics Data System (ADS)

L i X-ray production cross sections have been measured for Sm, Eu, Gd, Dy, Ho, Er, Pt, Au, Tl, Pb and Bi at 59.54 keV incident photon energy. The values of L i subshell fluorescence yields ( ?1, ?2 and ?3) have been determined using the presently measured X-ray production cross sections and the theoretical L i subshell photoionization cross sections values, Coster-Kronig transition probabilities and radiative emission rates. Furthermore, K to L shell vacancy transfer probabilities ? ( i=1, 2, 3) for Sm, Eu, Gd, Dy, Ho, Er were determined by measuring the L X-ray production cross section and L subshell fluorescence yields. The measurements were performed using an Am-241 radioisotope as the photon source and a Si(Li) detector. The measured X-ray production cross sections, fluorescence yields and vacancy transfer probabilities were compared with the theoretical values. The results in the present paper are found to be in good agreement with the calculated values.

Han, I.; Demir, L.; A?baba, M.

2007-10-01

28

Transition Planning  

ERIC Educational Resources Information Center

Post-school transition is the movement of a child with disabilities from school to activities that occur after the completion of school. This paper provides information about: (1) post-school transition; (2) transition plan; (3) transition services; (4) transition planning; (5) vocational rehabilitation services; (6) services that are available…

Statfeld, Jenna L.

2011-01-01

29

Transition Invariants  

Microsoft Academic Search

Proof rules for program verification rely on auxiliary assertions. We propose a (sound and relatively complete) proof rule whose auxiliary assertions are transition invari- ants. A transition invariant of a program is a binary rela- tion over program states that contains the transitive closure of the transition relation of the program. A relation is dis- junctively well-founded if it is

Andreas Podelski; Andrey Rybalchenko

2004-01-01

30

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

31

Transition & Beyond  

MedlinePLUS

... Education Caring for Your Family Transition & Beyond Aging Matters Research NDSS en Español Ways to Give Ways to ... Education Caring for Your Family Transition & Beyond Aging Matters Research NDSS en Español Ways to Give Ways to ...

32

Transitional Care  

ERIC Educational Resources Information Center

Transitional care encompasses a broad range of services and environments designed to promote the safe and timely passage of patients between levels of health care and across care settings. High-quality transitional care is especially important for older adults with multiple chronic conditions and complex therapeutic regimens, as well as for their…

Naylor, Mary; Keating, Stacen A.

2008-01-01

33

Transit Math  

NSDL National Science Digital Library

This is a collection of mathematical problems about transits in the solar system. Learners can work problems created to be authentic glimpses of modern science and engineering issues, often involving actual research data.

34

Transitional determinacies.  

PubMed

In classic generative grammar a distinction is drawn between linguistic 'competence' and linguistic 'performance', the former referring to linguistic knowledge, the latter to how linguistic knowledge is used. However, this controversial differentiation obscures the additional dichotomy between linguistic knowledge for production and linguistic knowledge for recognition. In this article it is shown that production and recognition differ, that recognition is not simply the inverse of production, and that the derivation of production from recognition and recognition from production require a small set of generalizable 'transitional determinacies'. Secondly, it is shown that transitional determinacies explain the difference between 'overt' and 'covert' recognition recently observed in prosopagnosics, patients unable to recognize familiar faces. Prosopagnosics and normals are found to differ in their transitional determinacies, such that prosopagnosics require more binders (precisors) for covert recognition than normals. In general, it is concluded that transitional determinacies are as necessary to the theory of grammar as determinacies themselves. PMID:1286840

Luelsdorff, P A

1992-01-01

35

LMM Auger primary excitation spectra of copper  

NASA Astrophysics Data System (ADS)

The shape and intensity of measured Auger peaks are strongly affected by extrinsic excitations due to electron transport out of the surface and to intrinsic excitations induced by the sudden creation of the two static core holes. Following a method developed for XPS in a previous work [N. Pauly, S. Tougaard, F. Yubero, Surf. Sci. 620 (2014) 17], we have calculated the effective energy-differential inelastic electron scattering cross-sections, including the effects of the surface and of the two core holes, within the dielectric response theory by means of the QUEELS-XPS software (QUantitative analysis of Electron Energy Losses at Surfaces for XPS). The Auger spectra are then modeled by convoluting this energy loss cross section with the primary excitation spectrum that accounts for all effects which are part of the initial Auger process, i.e. L-S coupling and vacancy satellite effects. The shape of this primary excitation spectrum is fitted to get close agreement between the theoretical and the experimental spectra obtained from X-ray excited Auger electron spectroscopy (XAES). We have performed these calculations of XAES spectra for various LMM Auger transitions of pure Cu (L3M45M45, L3M23M45, L3M23M23 and L2M45M45 transitions). We compare the resulting primary excitation spectra with theoretical results published in the literature and obtain reasonable quantitative agreement. In particular, we extract from experimental spectra quantitative intensities due to Coster-Kronig, shake-off and shake-up processes relative to the intensity from the “normal” Auger process.

Pauly, N.; Tougaard, S.; Yubero, F.

2014-12-01

36

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

37

Metric transition  

NASA Technical Reports Server (NTRS)

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.

1992-01-01

38

STEM Transitions  

NSDL National Science Digital Library

Under the direction of the Center for Occupational Research and Development (CORD), the STEM Transitions initiative has worked with 40 community college faculty to create integrated curriculum projects for use in math, science, and technical courses in the six STEM-related clusters. Much of this work has been funded by the U.S. Department of Education's Office of Vocational and Adult Education. First-time visitors can get an overview in the "Using This Site" area and then visit the "Integrated Projects" area. After signing up for a free account, they can take advantage of over 60 lesson plans and activities such as "The Secret Ingredient: Nutrient Analysis of Selected Food Items" and "Good Dirty, Bad Dirty: Soil Types and Erosion Potential." The site also provides information about upcoming webinars and workshops sponsored by the STEM Transitions, along with information about their faculty affiliates.

39

Eliminating Transitions  

ERIC Educational Resources Information Center

Adults often find themselves transitioning from one activity to another in a short time span. Most of the time, they do not feel they have a lot of control over their schedules, but wish that they could carve out extended time to relax and focus on one project. Picture a group of children in the block area who have spent 15 or 20 minutes building…

Gallick, Barb; Lee, Lisa

2010-01-01

40

Breakdown of one-electron pictures in photoelectron spectra  

Microsoft Academic Search

The purpose of this review is to describe some spectacular effects of many-electron interactions in certain core levels in\\u000a heavy atoms, as well as to give an overview of closely related phenomena in molecules, solids and adsorbates. The central\\u000a concept will be what we shall call giant Coster-Kronig (gCK) fluctuation and decay of a hole level, involving ineraction of a

Göran Wendin

41

Tips for Transition  

ERIC Educational Resources Information Center

The Tips for Transition contains 134 Transition Tips submitted from all over the country by practitioners. The purpose of the Tips was to identify grassroots transition practices being used by practitioners. Tips are categorized into the following domains: (1) Transition Planning; (2) Student Involvement; (3) Family Involvement; (4) Curriculum and…

Kellems, Ryan, Comp.; Morningstar, Mary E., Comp.

2009-01-01

42

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.

43

Gas turbine combustor transition  

DOEpatents

A method is described for 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. 7 figs.

Coslow, B.J.; Whidden, G.L.

1999-05-25

44

Transitional Tetrapod Fossil  

NSDL National Science Digital Library

In this video segment from NOVA: Judgment Day: Intelligent Design on Trial, learn about the discovery of a well-preserved transitional fossil and how such transitional fossils support the theory of evolution.

Foundation, Wgbh E.

2007-11-01

45

Transition in Turbines  

NASA Technical Reports Server (NTRS)

The concept of a large disturbance bypass mechanism for the initiation of transition is reviewed and studied. This mechanism, or some manifestation thereof, is suspected to be at work in the boundary layers present in a turbine flow passage. Discussion is presented on four relevant subtopics: (1) the effect of upstream disturbances and wakes on transition; (2) transition prediction models, code development, and verification; (3) transition and turbulence measurement techniques; and (4) the hydrodynamic condition of low Reynolds number boundary layers.

1985-01-01

46

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

47

Origins of evolutionary transitions.  

PubMed

An 'evolutionary transition in individuality' or 'major transition' is a transformation in the hierarchical level at which natural selection operates on a population. In this article I give an abstract (i.e. level-neutral and substrate-neutral) articulation of the transition process in order to precisely understand how such processes can happen, especially how they can get started. PMID:24736161

Clarke, Ellen

2014-04-01

48

One-particle transition.  

E-print Network

One-particle di#11;usional model to mimic some properties of glass transition. Sorkin A.V., Ivanov #15; Computer studies of glass transition #15; Model and simulations #15; Results #15; Conclusions 2 #12; Introduction In recent time many properties of glass transitions have been investigated

Adler, Joan

49

Light Rail Transit Strengthening  

E-print Network

Light Rail Transit Improving mobility Easing congestion Strengthening our communities Central Corridor Communicating to the Public During Major Construction May 25, 2011 #12;2 Light Rail Transit;Light Rail Transit Central Corridor Route and Stations 3 · 18 new stations · 9.8 miles of new double

Minnesota, University of

50

Gifts from Exoplanetary Transits  

E-print Network

The discovery of transiting extrasolar planets has enabled us a number of interesting stduies. Transit photometry reveals the radius and the orbital inclination of transiting planets, and thereby we can learn the true mass and the density of respective planets by the combined information of radial velocity measurements. In addition, follow-up observations of transiting planets such as secondary eclipse, transit timing variations, transmission spectroscopy, and the Rossiter-McLaughlin effect provide us information of their dayside temperature, unseen bodies in systems, planetary atmospheres, and obliquity of planetary orbits. Such observational information, which will provide us a greater understanding of extrasolar planets, is available only for transiting planets. Here I briefly summarize what we can learn from transiting planets and introduce previous studies.

Narita, Norio

2009-01-01

51

Planning for transition care.  

PubMed

The Australian Government introduced the National Transition Care Program in the 2004-2005 Federal Budget. This program is designed to assist elderly patients who have completed a stay in hospital to move from the hospital to their homes or other suitable accommodation. In planning for transition care services, managers are faced with the question, "How many places should be allocated to transition care in our facility?" This case study offers an approach to this question based on queueing theory. PMID:18666879

Crombie, Angela; Ham, Jenni; Masman, Kevin; Mills, Terence M

2008-08-01

52

Paradoxical embolus in transit.  

PubMed

Thrombus straddling a patent foramen ovale, namely, a paradoxical embolus in transit, is a rarely identified entity signifying impending arterial embolism. We report a series of 3 patients with preoperatively or intraoperatively identified paradoxical embolus in transit. All patients underwent surgical evacuation and had unremarkable postoperative courses with no episodes of arterial embolization. Surgical embolectomy should be considered early in the treatment of paradoxical embolus in transit. PMID:25087801

Worku, Berhane; Gulkarov, Iosif; Steele, Jeremy; Kadosh, Bernard; Skubas, Nikolaos J; Girardi, Leonard N; Salemi, Arash

2014-08-01

53

Bacterial Transition Metal Homeostasis  

Microsoft Academic Search

Since details on metal cation transport proteins and on the allocation mechanisms for transition metals\\u000a are provided elsewhere in this book, I will present aspects of transition metal homeostasis in a hopefully\\u000a novel overview. We will start with a microbial look at the transition metal Periodic Table, cation speciation,\\u000a and availability in the environment. This information provides rules that might

Dietrich H. Nies

54

Anomalous radiative transitions  

E-print Network

Anomalous transitions involving photons derived by many-body interaction of the form, $\\partial_{\\mu} G^{\\mu}$, in the standard model are studied. This does not affect the equation of motion in the bulk, but makes wave functions modified, and causes the unusual transition characterized by the time-independent probability. In the transition probability at a time-interval $T$ expressed generally in the form $P=T \\Gamma_0 +P^{(d)}$, now with $ P^{(d)} \

Kenzo Ishikawa; Toshiki Tajima; Yutaka Tobita

2014-09-15

55

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

56

Photoinduced phase transitions.  

PubMed

Optically induced ultrafast electronic excitations with sufficiently long lifetimes may cause strong effects on phase transitions like structural and nonmetal?metal ones and on supercooling, supersaturation, etc. Examples are the transitions diamond?graphite, graphite?graphene, non-metal?metal, solid?liquid and vapor?liquid, solid. Photoinduced formation of graphene and water condensation of saturated or supersaturated vapor due to increased bonding amongst water molecules are of particular interest. These nonequilibrium transitions are an ultrafast response, on a few hundred fs time scale, to the fast low to large energy electronic excitations. The energy of the photons is converted into electronic energy via electronic excitations changing the cohesive energy. This changes the chemical potential controlling the phase transition. In view of the advances in laser optics photon induced transitions are expected to become an active area in nonequilibrium physics and phase transition dynamics. Conservation laws like energy or angular momentum conservation control the time during which the transitions occur. Since the photon induced effects result from weakening or strengthening of the bonding between the atoms or molecules transitions like solid/liquid, etc can be shifted in both directions. Photoinduced transitions will be discussed from a unified point of view. PMID:21411879

Bennemann, K H

2011-02-23

57

Transitive associations 1 Running head: TRANSITIVE ASSOCIATIONS  

E-print Network

subjects recall a list of words in the order they come to mind. The conditional response probability; Kahana, Howard, Zaromb, & Wingfield, 2002; Klein, Addis, & Kahana, 2005) estimates the probability of making a recall transition from a just-recalled words to other words in the list as a function

Howard, Marc

58

Transition: driving and exercise.  

PubMed

There are many social aspects to consider at the time of transition of adolescents with epilepsy. The role of both pediatric and adult health care providers includes education and guidance within the larger framework of family, society, and country. This section focuses on driving and exercise considerations for those undergoing transition. PMID:25209086

Nashef, Lina; Capovilla, Giuseppe; Camfield, Carol; Camfield, Peter; Nabbout, Rima

2014-08-01

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

Quantum Phase Transitions  

Microsoft Academic Search

Quantum Phase Transitions details the fundamental changes that can occur in the macroscopic nature of matter at zero temperature due to small variations in a given external parameter. The author develops the theory of quantum phase transitions in the simplest possible class of nondisordered, interacting systems--the quantum Ising and rotor models. He pays particular attention to their non-zero temperature dynamic

Subir Sachdev; Matthew P. A. Fisher

2001-01-01

61

Transitions: An Institutionalist Perspective  

Microsoft Academic Search

A transition to a new technological regime is complete (and stable) when accompanied with a co-stabilization between the mode of regulation and the regime of accumulation. Key to understanding the dynamics of transitions are the factors, including institutions, that “regulate” and stabilize the regime of accumulation over time. However, the available frameworks for institutional analysis employ arbitrary and narrow definition

Saeed Parto

2003-01-01

62

Transitions in Spousal Caregiving.  

ERIC Educational Resources Information Center

Describes transitions over 5 years among community-dwelling elderly spouses into and within caregiving roles and associated health outcomes. The trajectory of health outcomes associated with caregiving was generally downward. Those who transitioned to heavy caregiving had more symptoms of depression, and poorer self-reported health and health…

Burton, Lynda C.; Zdaniuk, Bozena; Schulz, Richard; Jackson, Sharon; Hirsch, Calvin

2003-01-01

63

Expanding Views on Transition.  

ERIC Educational Resources Information Center

This position paper proposes an expanded definition of transition, based on common components of early childhood and secondary perspectives. It advocates for a seamless model of transition service delivery for students with disabilities, including program planning, from birth through age 21. The model addresses curriculum, location of services,…

Repetto, Jeanne B.; Correa, Vivian I.

1996-01-01

64

Russia's Economic Transitions  

Microsoft Academic Search

Russia's Economic Transitions examines the three major transformations that the country underwent from the early 1860s to 2000. The first transition, under Tsarism, involved the partial break-up of the feudal framework of land ownership and the move toward capitalist relations. The second, following the Communist revolution of 1917, brought to power a system of state ownership and administration - a

Nicolas Spulber

65

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.; Iuchi, Kanako; Suzuki, Hiroaki

66

Demographics of Transition Objects  

E-print Network

The unusual properties of transition objects (young stars with an optically thin inner disc surrounded by an optically thick outer disc) suggest that significant disc evolution has occured in these systems. We explore the nature of these systems by examining their demographics, specifically their stellar accretion rates (Mdot) and disc masses (Mdisc) compared to those of accreting T Tauri stars of comparable age. We find that transition objects in Taurus occupy a restricted region of the Mdot vs. Mdisc plane. Compared to non-transition single stars in Taurus, they have stellar accretion rates that are typically ~10 times lower at the same disc mass and median disc masses ~4 times larger. These properties are anticipated by several proposed planet formation theories and suggest that the formation of Jovian mass planets may play a significant role in explaining the origin of at least some transition objects. Considering transition objects as a distinct demographic group among accreting T Tauri stars leads to a ...

Najita, Joan R; Muzerolle, James

2007-01-01

67

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

68

MATHEMATICS: RETHINKING THE TRANSITION  

E-print Network

SENIOR SECONDARY MATHEMATICS: RETHINKING THE TRANSITION BILL BARTON THE UNIVERSITY OF AUCKLAND, NZ #12;THE ENVISIONING PROJECT · Mathematics education project of NZIMA (New Zealand Institute of Mathematics & Its Applications--the mathematics research funding body). · Brought together mathematics

Peters, Achim

69

Transition to Adulthood  

MedlinePLUS

... areas such as postsecondary education or vocational training, employment, independent living, and community participation. Transition services must ... school activities, including postsecondary education, vocational education, ... (including supported employment), continuing and adult education, adult ...

70

Exoplanet Transit Parallax  

E-print Network

The timing and duration of exoplanet transits has a dependency on observer position due to parallax. In the case of an Earth-bound observer with a 2 AU baseline the dependency is typically small and slightly beyond the limits of current timing precision capabilities. However, it can become an important systematic effect in high-precision repeated transit measurements for long period systems due to its relationship to secular perspective acceleration phenomena. In this short paper we evaluate the magnitude and characteristics of transit parallax in the case of exoplanets using simplified geometric examples. We also discuss further implications of the effect, including its possible exploitation to provide immediate confirmation of planetary transits and/or unique constraints on orbital parameters and orientations.

Caleb A. Scharf

2007-02-28

71

Transiting Exoplanets with JWST  

E-print Network

The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is poised for the significant achievement of identifying habitable planets around bright M through G stars--rocky planets lacking extensive gas envelopes, with water vapor and signs of chemical disequilibrium in their atmospheres. Favorable transiting planet systems, are, however, anticipated to be rare and their atmosphere observations will require tens to hundreds of hours of JWST time per planet. We review what is known about the physical characteristics of transiting planets, summarize lessons learned from Spitzer high-contrast exoplanet measurements, and give several examples of potential JWST observations.

S. Seager; D. Deming; J. A. Valenti

2008-08-13

72

Quantum Phase Transitions  

NASA Astrophysics Data System (ADS)

Part I. Introduction: 1. Basic concepts; 2. Overview; Part II. A First Course: 3. Classical phase transitions; 4. The renormalization group; 5. The quantum Ising model; 6. The quantum rotor model; 7. Correlations, susceptibilities, and the quantum critical point; 8. Broken symmetries; 9. Boson Hubbard model; Part III. Non-zero Temperatures: 10. The Ising chain in a transverse field; 11. Quantum rotor models: large-N limit; 12. The d = 1, O(N ? 3) rotor models; 13. The d = 2, O(N ? 3) rotor models; 14. Physics close to and above the upper-critical dimension; 15. Transport in d = 2; Part IV. Other Models: 16. Dilute Fermi and Bose gases; 17. Phase transitions of Dirac fermions; 18. Fermi liquids, and their phase transitions; 19. Heisenberg spins: ferromagnets and antiferromagnets; 20. Spin chains: bosonization; 21. Magnetic ordering transitions of disordered systems; 22. Quantum spin glasses; References; Index.

Sachdev, Subir

2011-04-01

73

Transit Promotional Materials Clearinghouse.  

National Technical Information Service (NTIS)

Development of promotional and communications collateral can be an expensive and time-consuming undertaking for public transit systems, especially in today's environment of down-sizing and tight budgeting. A survey of transportation professionals revealed...

J. Horton, W. Mustard

2001-01-01

74

Quantum phase transitions  

Microsoft Academic Search

In recent years, quantum phase transitions have attracted the interest of\\u000aboth theorists and experimentalists in condensed matter physics. These\\u000atransitions, which are accessed at zero temperature by variation of a\\u000anon-thermal control parameter, can influence the behavior of electronic systems\\u000aover a wide range of the phase diagram. Quantum phase transitions occur as a\\u000aresult of competing ground state

Thomas Vojta

2003-01-01

75

Stability, transition and turbulence  

NASA Technical Reports Server (NTRS)

A glimpse is provided of the research program in stability, transition, and turbulence based on numerical simulations. This program includes both the so-called abrupt and the restrained transition processes. Attention is confined to the prototype problems of channel flow and the parallel boundary layer in the former category and the Taylor-Couette flow in the latter category. It covers both incompressible flows and supersonic flows. Some representative results are presented.

Hussaini, M. Y.

1987-01-01

76

Stability, transition and turbulence  

NASA Technical Reports Server (NTRS)

A glimpse is provided of the research program in stability, transition and turbulence based on numerical simulations. This program includes both the so-called abrupt and the restrained transition processes. Attention is confined to the prototype problems of channel flow and the parallel boundary layer in the former category and the Taylor-Couette flow in the latter category. It covers both incompressible flows and supersonic flows. Some representative results are presented.

Hussaini, M. Y.

1987-01-01

77

Transition Path Theory  

Microsoft Academic Search

The dynamical behavior of many systems arising in physics, chemistry, biology, etc. is dominated by rare but important transition\\u000a events between long lived states. For over 70 years, transition state theory (TST) has provided the main theoretical framework\\u000a for the description of these events [17,33,34]. Yet, while TST and evolutions thereof based on the reactive flux formalism\\u000a [1, 5] (see

E. vanden-Eijnden

2006-01-01

78

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

79

Demographics of transition objects  

NASA Astrophysics Data System (ADS)

The unusual properties of transition objects (young stars with an optically thin inner disc surrounded by an optically thick outer disc) suggest that significant disc evolution has occurred in these systems. We explore the nature of these systems by examining their demographics, specifically their stellar accretion rates and disc masses Mdisc compared to those of accreting T Tauri stars of comparable age. We find that the transition objects in Taurus occupy a restricted region of the versus Mdisc plane. Compared to non-transition single stars in Taurus, they have stellar accretion rates that are typically ~10 times lower at the same disc mass and median disc masses approximately four times larger. These properties are anticipated by several proposed planet formation theories and suggest that the formation of Jovian mass planets may play a significant role in explaining the origin of at least some transition objects. Considering transition objects as a distinct demographic group among accreting T Tauri stars leads to a tighter relationship between disc masses and stellar accretion rates, with a slope between the two quantities that is close to the value of unity expected in simple theories of disc accretion.

Najita, Joan R.; Strom, Stephen E.; Muzerolle, James

2007-06-01

80

Demographics of Transition Objects  

E-print Network

The unusual properties of transition objects (young stars with an optically thin inner disc surrounded by an optically thick outer disc) suggest that significant disc evolution has occured in these systems. We explore the nature of these systems by examining their demographics, specifically their stellar accretion rates (Mdot) and disc masses (Mdisc) compared to those of accreting T Tauri stars of comparable age. We find that transition objects in Taurus occupy a restricted region of the Mdot vs. Mdisc plane. Compared to non-transition single stars in Taurus, they have stellar accretion rates that are typically ~10 times lower at the same disc mass and median disc masses ~4 times larger. These properties are anticipated by several proposed planet formation theories and suggest that the formation of Jovian mass planets may play a significant role in explaining the origin of at least some transition objects. Considering transition objects as a distinct demographic group among accreting T Tauri stars leads to a tighter relationship between disc masses and stellar accretion rates, with a slope between the two quantities that is close to the value of unity expected in simple theories of disc accretion.

Joan R. Najita; Stephen E. Strom; James Muzerolle

2007-04-13

81

RTGs on Transit  

NASA Astrophysics Data System (ADS)

Transit, the US Navy's Navigation Satellite System was conceived at the Applied Physics Laboratory in 1957 by observing the Doppler shift while tracking Sputnik I. As spacecraft development proceeded there was concern about the ability of batteries to maintain the hermetic seal over a 5-year operational life requirement; therefore, alternate energy sources were investigated. The radioisotope thermoelectric generator (RTG) concept was pursued and resulted in the launch of SNAP 3s, providing partial power on both Transit 4A and 4B. SNAP 9s provided full power on three Transit 5BNs. All launches occurred in the early 1960s. When the U.S. conducted the high altitude nuclear test from Johnson Island, several spacecraft were lost due to artificial enhancement of charged particles in the Earth's magnetosphere resulting in rapid degradation of solar cell power production. This led to the decision to have both an RTG and Solar cell/battery design for Transit power systems; hence, a new RTG design, with a separable heat source and radiative coupling to the thermoelectric elements, was flown on TRIAD. This pioneering effort provided the impetus for future RTGs on interplanetary spacecraft. This paper describes the origin and purpose of the Transit program and provides details on the five satellites in that program that were powered by the first American RTGs used in space. The rationale and some of the challenges inherent in that use are also described.

Dassoulas, John; McNutt, Ralph L.

2007-01-01

82

Certificate in Transit Management and  

E-print Network

Engineering and the School of Management - Internships with UMass Transit and CTTransit - A summer workshop is a contract carrier for the Pioneer Valley Transit Authority located in Western Massachusetts. The bus system is an operating arm of First Transit a U.S. based private transit management company with more than 51 years

Massachusetts at Amherst, University of

83

Venus Transit 2004  

NSDL National Science Digital Library

In just several weeks, Venus, the Earth's sister planet, will pass in front of the sun, affording astronomers and the general public the ability to take part in a extremely rare event. While persons in Europe, Africa, and Asia will have the best vantage point for this occurrence, those interested in the Venus transit will want to take a detailed look at this lovely website in order to find out more about the event. Launched by the European Southern Observatory and the European Association for Astronomy Education (in cooperation with three other organizations), the site contains ample information about the latest news from the project, detailed background material about this astronomical event, the network of institutions involved with the project, and information on how individuals may participate in the Venus Transit 2004 project. One of the most helpful areas contains animations of the Venus transit from different perspectives.

84

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

85

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

86

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

87

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

88

Career Transitions: ERIC Digest.  

ERIC Educational Resources Information Center

Some intervention programs have responded to the magnitude of the difficulties that career transitions present for adults. This digest examines one program which aims to improve the career adaptability of adults seeking employment. The interventional procedures outlined here are intended to accelerate vocational development by helping people…

Riverin-Simard, Danielle

89

Families in Transition.  

ERIC Educational Resources Information Center

This issue of "Emphasis" deals with families in transition, providing some model programs for the new family and some historical perspectives on how families have developed over time. Articles include: (1) "Nostalgia on the Right" (Nancy Theriot); (2) "Heart to Heart" (Nancy Harrington-MacLennan); (3) "The Media Get the Message" (Janet Alyn); (4)…

Britton, Patti O., Ed.; McGee, Michael, Ed.

1987-01-01

90

String mediated phase transitions  

NASA Technical Reports Server (NTRS)

It is demonstrated from first principles how the existence of string-like structures can cause a system to undergo a phase transition. In particular, the role of topologically stable cosmic string in the restoration of spontaneously broken symmetries is emphasized. How the thermodynamic properties of strings alter when stiffness and nearest neighbor string-string interactions are included is discussed.

Copeland, ED; Haws, D.; Rivers, R.; Holbraad, S.

1988-01-01

91

The TRANSITION Program.  

ERIC Educational Resources Information Center

Operated on a voluntary, decentralized basis at 215 military bases (58 overseas), the TRANSITION Program is designed to provide maximum guidance and training or educational opportunities for servicemen during their last six months of duty to prepare them for productive reentry into civilian life. Public and private placement services are also…

Office of the Assistant Secretary of Defense for Manpower and Reserve Affairs (DOD), Washington, DC.

92

Immigration and Adult Transitions  

ERIC Educational Resources Information Center

Almost 30 percent of the more than 68 million young adults aged eighteen to thirty-four in the United States today are either foreign born or of foreign parentage. As these newcomers make their transitions to adulthood, say Ruben Rumbaut and Golnaz Komaie, they differ significantly not only from one another but also from their native-parentage…

Rumbaut, Ruben G.; Komaie, Golnaz

2010-01-01

93

Completing the Demographic Transition  

Microsoft Academic Search

Despite ongoing declines in fertility in many countries, the population of the world is experiencing a period of rapid expansion, and its size is expected to reach 10 billion by the end of the demographic transition. Three causes of this growth are identified and quantified: 1) fertility above the replacement level of two surviving children per woman, 2) continuing declines

John Bongaarts; Rodolfo A. Bulatao

1999-01-01

94

A Survey Transition Course  

ERIC Educational Resources Information Center

Successful outcomes for a "Transition Course in Mathematics" have resulted from two unique design features. The first is to run the course as a "survey course" in mathematics, introducing sophomore-level students to a broad set of mathematical fields. In this single mathematics course, undergraduates benefit from an introduction of proof…

Johnston, William; McAllister, Alex M.

2012-01-01

95

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

96

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

97

Families in Transition .  

ERIC Educational Resources Information Center

Focuses on disrupted families and the role of the school counselor in helping children adjust. Describes characteristics of healthy families, and discusses the transition to the blended family, effects of divorce groups on children's classroom behavior, counseling children in stepfamilies, single-parent families, and parenting strengths of single…

Bundy, Michael L., Ed.; Gumaer, James, Ed.

1984-01-01

98

Learning for Life Transitions  

ERIC Educational Resources Information Center

Many adults return to formal learning situations to pursue lifelong learning goals because their lives are in transition from dealing with real-life problems such as divorce and re-marriage. The purpose of this study was to describe what couples learned that contributed to the success of their subsequent marriages and how they learned it. The…

Varmecky, Jane Hyde

2012-01-01

99

Tips for Transition  

ERIC Educational Resources Information Center

The Individuals With Disabilities Education Improvement Act of 2004 (IDEA) states that transition planning should begin at the earliest age appropriate and no later than age 16. IDEA requires schools to make collaborative efforts to provide students access to an array of postschool activities including integrated employment, postsecondary…

Kellems, Ryan O.; Morningstar, Mary E.

2010-01-01

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

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

102

TRANSITION STRATEGIES Sig Gronich  

E-print Network

to work, the program's pre-competitive research must be adopted by the industrial partners · DOE should production Electrochemical Energy Storage · The development of high-energy batteries would increase Research Council to evaluate the transition phase and do not represent any specific policy recommendation

103

Variational transition state theory  

SciTech Connect

This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

1993-12-01

104

TRANSITIONAL SETTLEMENTS Planning Homeless  

E-print Network

TRANSITIONAL SETTLEMENTS 1 Planning Homeless Settlement Communities Western Washington University- came clear that their presence among us was not the result of some aberration in the socio- economic the living conditions faced by our fellow citizens who live in Homeless camps, public resources are necessary

Zaferatos, Nicholas C.

105

String Mediated Phase Transitions.  

National Technical Information Service (NTIS)

It is demonstrated from first principles how the existence of string-like structures can cause a system to undergo a phase transition. In particular, the role of topologically stable cosmic string in the restoration of spontaneously broken symmetries is e...

E. Copeland, D. Haws, R. Rivers, S. Holbraad

1988-01-01

106

Transition at hypersonic speeds  

NASA Technical Reports Server (NTRS)

Certain conjectures on the physics of instabilities in high-speed flows are discussed and the state of knowledge of hypersonic transition summarized. The case is made for an unpressured systematic research program in this area consisting of controlled microscopic experiments, theory, and numerical simulations.

Morkovin, Mark V.

1987-01-01

107

Transit of Extrasolar Planets  

NASA Technical Reports Server (NTRS)

During the past five years we have pursued the detection of extrasolar planets by the photometric transit method, i.e. the detection of a planet by watching for a drop in the brightness of the light as it crosses in front of a star. The planetary orbit must cross the line-of-sight and so most systems will not be lined up for such a transit to ever occur. However, we have looked at eclipsing binary systems which are already edge-on. Such systems must be very small in size as this makes the differential light change due to a transit much greater for a given planet size (the brightness difference will be proportional to the area of the transiting planet to the disc area of the star). Also, the planet forming region should be closer to the star as small stars are generally less luminous (that is, if the same thermal regime for planet formation applies as in the solar system). This led to studies of the habitable zone around other stars, as well. Finally, we discovered that our data could be used to detect giant planets without transits as we had been carefully timing the eclipses of the stars (using a GPS antenna for time) and this will drift by being offset by any giant planets orbiting around the system, as well. The best summary of our work may be to just summarize the 21 refereed papers produced during the time of this grant. This will be done is chronological order and in each section separately.

Doyle, Laurance R.

1998-01-01

108

Water's second glass transition  

PubMed Central

The glassy states of water are of common interest as the majority of H2O in space is in the glassy state and especially because a proper description of this phenomenon is considered to be the key to our understanding why liquid water shows exceptional properties, different from all other liquids. The occurrence of water’s calorimetric glass transition of low-density amorphous ice at 136 K has been discussed controversially for many years because its calorimetric signature is very feeble. Here, we report that high-density amorphous ice at ambient pressure shows a distinct calorimetric glass transitions at 116 K and present evidence that this second glass transition involves liquid-like translational mobility of water molecules. This “double Tg scenario” is related to the coexistence of two liquid phases. The calorimetric signature of the second glass transition is much less feeble, with a heat capacity increase at Tg,2 about five times as large as at Tg,1. By using broadband-dielectric spectroscopy we resolve loss peaks yielding relaxation times near 100 s at 126 K for low-density amorphous ice and at 110 K for high-density amorphous ice as signatures of these two distinct glass transitions. Temperature-dependent dielectric data and heating-rate–dependent calorimetric data allow us to construct the relaxation map for the two distinct phases of water and to extract fragility indices m = 14 for the low-density and m = 20–25 for the high-density liquid. Thus, low-density liquid is classified as the strongest of all liquids known (“superstrong”), and also high-density liquid is classified as a strong liquid. PMID:24101518

Amann-Winkel, Katrin; Gainaru, Catalin; Handle, Philip H.; Seidl, Markus; Nelson, Helge; Bohmer, Roland

2013-01-01

109

Atomic Electron Spectrometry with Synchrotron Radiation  

NASA Astrophysics Data System (ADS)

Techniques of atomic electron spectrometry were applied to atoms in the gaseous and solid states to derive information about fundamental atomic properties. A new method was developed to measure Coster-Kronig yields in metals by photoionization with synchrotron radiation. Photon -energy sensitive Si L-VV Auger satellites were investigated via electron spectrometry. The krypton 1s photoionization spectrum was measured in an experiment which was motivated by the need to understand the krypton 1s satellite spectrum for calibration of an experiment to measure the mass of the electron antineutrino.

Sorensen, Stacey Lynne

110

Measurements and calculations of M-shell X-ray production in Er, Yb and Lu by 0.75 6 MeV He ions  

NASA Astrophysics Data System (ADS)

M-shell X-ray production cross sections for the light rare-earth elements of 68Er, 70Yb and 71Lu have been measured for incident 4He + ions in the energy range from 0.75 to 6 MeV. The measured X-ray production cross sections are compared to the predictions of the First Born approximation, the ECPSSR theory and the ECUSAR theory. A comparison of the ytterbium M-shell X-ray production cross sections with these theories is made for two different sets of fluorescence yields and Coster-Kronig factors that are further modified for multiple ionization.

Naab, F.; Duggan, J. L.; Holland, O. W.; McDaniel, F. D.; Lapicki, G.

2005-12-01

111

[Cancer and demographic transition].  

PubMed

Two phenomena, one of which relates to the area of human reproduction and the other to the frequency, distribution, and control of disease in a population have emerged in the previous century and continue intensively to develop nowadays. Both these phenomena are directly related to the changes which are occurring in the incidence and prevalence of malignant tumours, as well as to mortality from them and to the opportunities for cancer control. The first of these phenomena has been denominated as the demographic, and the second as the epidemiological transition. The commonly accepted definition of the demographic transition is currently applied to designate a sustainable change in the type of population reproduction, when an initial and abrupt acceleration of population growth is replaced by its rapid deceleration with a subsequent stabilization of a population and a sharp change in its age structure. Demographic transition develops in a brief historical space of time and has the character of a global process. Population ageing and disequilibrium between the younger and older generations are the most important consequences of the demographic transition, and must inevitably influence the strategy and implementation of national cancer control programs. As life expectancy increases, so does the certainty that people will become more and more prone to diseases that are more common among older age groups, i.e. noncommunicable diseases and cancer in particular, rather than being affected by epidemics of infectious diseases. This situation is known as the epidemiological transition and reflects spectacular shifts in the pattern and causes of death and morbidity that have taken place in the vast majority of countries over the previous century. Epidemiological transition results in accession by poor countries to the problems of the rich, and leads to the "double burden" of disease in countries whose economies are undergoing transition, because of the still continuing burden of endemic infectious diseases. Russia is entering the final stages both of the demographic and the epidemiological transition, a period when numerous reasons, increasing demands on the systems of social protection and public health are inevitable. During the years 1992 to 2001, cancer incidence increased from 271.8 up to 313.9 per 100,000 population, i.e. a growth of over 16% and an annual rate of growth of 1.7%. According to the global estimates provided by the International Agency for Research on Cancer the number of new cancer cases in the year 2000 exceeded 10 million, and the number of deaths from cancer reached 6.2 million. The annual growth rate of global cancer incidence during the last 25-30 years was higher than the global population growth rate. Analysis of data available from population based cancer registries in Russia and abroad confirms the conclusion that cancer is mainly the fate of people belonging to the older age groups. Given the levels of exposure to specific carcinogens and genetic predisposition factors, the incidence of cancer should be considered as an exponential function of age. The unfeasibility of attempts to change, in the foreseeable future, the rate and trend of demographic transition and demographic ageing, in particular, is obvious. It would therefore be more feasible to envisage their probable consequences and to adapt the limited resources of national health and social support services to the needs of cancer control, which will significantly increase in the near future. PMID:15176213

Napalkov, N P

2004-01-01

112

75 FR 76921 - Tobacco Transition Payment Program; Tobacco Transition Assessments  

Federal Register 2010, 2011, 2012, 2013

...Payment Program; Tobacco Transition Assessments AGENCY...regulations for the Tobacco Transition Payment Program (TTPP...A of the assessment process; Step B is the division...relying on State and local processes for State and local...applies, is: Tobacco Transition Payment...

2010-12-10

113

Emergence and Phase Transitions  

NASA Astrophysics Data System (ADS)

Phase transitions are well defined in physics through concepts such as spontaneous symmetry breaking, order parameter, entropy, and critical exponents. But emergence --- also exhibiting whole-part relations (such as top-down influence), unpredictability, and insensitivity to microscopic detail --- is a loosely-defined concept being used in many disciplines, particularly in psychology, biology, philosophy, as well as in physics[1,2]. I will review the concepts of emergence as used in the various fields and consider the extent to which the methods of phase transitions can clarify the usefulness of the concept of emergence both within the discipline of physics and beyond.1. Robert B. Laughlin, A Different Universe: Reinventing Physics from the Bottom Down (New York: Basic Books, 2005). 2. George F.R. Ellis, ``Physics and the Real World'', Physics Today, vol. 58, no. 7 (July 2005) pp. 49-54.

Sikkema, Arnold

2006-05-01

114

Models for transition clinics.  

PubMed

Transition is a purposeful, planned process that addresses the medical, psychosocial, educational, and vocational needs of adolescents and young adults with chronic medical conditions, as they advance from a pediatric and family-centered to an adult, individual focused health care provider. This article describes some of the models for transition clinics or services for epilepsy in five countries (Canada, France, Colombia, Germany, and the United Kingdom). These models include joint adult and pediatric clinics, algorithm-driven service, and a check list system in the context of pediatric care. Evaluation of these models is limited, and it is not possible to choose an optimal program. The attitude and motivation of health care providers may be the most important elements. PMID:25209087

Carrizosa, Jaime; An, Isabelle; Appleton, Richard; Camfield, Peter; Von Moers, Arpad

2014-08-01

115

The Myths of Mass Transit.  

ERIC Educational Resources Information Center

Criticizes eight commonly held notions about the value of mass transit systems in public transportation programs. Alternative approaches for improving the quality and quantity of urban transit systems are discussed. (AM)

Burke, Catherine G.

1982-01-01

116

Transition-fault test generation  

E-print Network

. One way to detect these timing defects is to apply test patterns to the integrated circuit that are generated using the transition-fault model. Unfortunately, industry's current transition-fault test generation schemes produce test sets that are too...

Cobb, Bradley Douglas

2013-02-22

117

Capturing the Value of Transit.  

National Technical Information Service (NTIS)

Over the past decade, it has become increasingly clear that the presence of transit can increase property values and result in valuable development opportunities. In this era of constrained transit funding and widespread demand for new and expanded transi...

2008-01-01

118

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

119

Tips for Transition  

E-print Network

Tips for Transition a ö "a I s. Ryan O. Kellems Mary E. Morningstar One of the primary goals of school is to help students plan and prepare for tbe rest of their lives. This planning and preparation is especially important for students... E. Morningstar (Kansas CEC), Associate Professor, Department of Special Education, University of Kansas, Lawrence. Correspondence concerning this article should be addressed to Ryan Kellems, National Post-School Outcomes Center, Secondary Special...

Kellems, Ryan Owen; Morningstar, Mary E.

2010-01-01

120

High speed transition prediction  

NASA Technical Reports Server (NTRS)

The main objective of this work period was to develop, acquire and apply state-of-the-art tools for the prediction of transition at high speeds at NASA Ames. Although various stability codes as well as basic state codes were acquired, the development of a new Parabolized Stability Equation (PSE) code was minimal. The time that was initially allocated for development was used on other tasks, in particular for the Leading Edge Suction problem, in acquiring proficiency in various graphics tools, and in applying these tools to evaluate various Navier-Stokes and Euler solutions. The second objective of this work period was to attend the Transition and Turbulence Workshop at NASA Langley in July and August, 1991. A report on the Workshop follows. From July 8, 1991 to August 2, 1991, the author participated in the Transition and Turbulence Workshop at NASA Langley. For purposes of interest here, analysis can be said to consist of solving simplified governing equations by various analytical methods, such as asymptotic methods, or by use of very meager computer resources. From the composition of the various groups at the Workshop, it can be seen that analytical methods are generally more popular in Great Britain than they are in the U.S., possibly due to historical factors and the lack of computer resources. Experimenters at the Workshop were mostly concerned with subsonic flows, and a number of demonstrations were provided, among which were a hot-wire experiment to probe the boundary layer on a rotating disc, a hot-wire rake to map a free shear layer behind a cylinder, and the use of heating strips on a flat plate to control instability waves and consequent transition. A highpoint of the demonstrations was the opportunity to observe the rather noisy 'quiet' supersonic pilot tunnel in operation.

Gasperas, Gediminis

1992-01-01

121

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

122

Equilibria in transition  

NASA Astrophysics Data System (ADS)

We investigate the motion of a single particle in transition from one equilibrium state to another via time-frequency analysis. Between quasi-stationary regimes a sudden change of state occurs, and we show that the Cohen-Lee local variance tracks well this highly nonstationary, sudden transient motion. In the quasi-stationary regime, instantaneous equilibria yield simple harmonic motion when the amplitude of oscillation is sufficiently small. Nonlinear effects induce harmonic generation for larger amplitude oscillations.

Hughes, David H.; Hedges, Robert A.; Suter, Bruce W.

2001-11-01

123

Transition mixing study  

NASA Technical Reports Server (NTRS)

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 which contain characteristics similar to transition liners, and for which experimental data was available. Comparisons between the predictions and measurements indicate that the code produces qualitative results but that the turbulence models, both K-E and algebraic Reynolds Stress, underestimate the cross-stream diffusion. The code has also been used to perform a numerical experiment to examine the effect of a variety of parameters on the mixing process in transition liners. Comparisons illustrate that geometries with significant curvature show a drift of the jet trajectory toward the convex wall and weaker wake region vortices and decreased penetration for jets located on the convex wall of the liner, when compared to jets located on concave walls. Also shown were the approximate equivalency of angled slots and round holes and a technique by which jet mixing correlations developed for rectangular channels can be used for can geometries.

Reynolds, R.; White, C.

1986-01-01

124

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. PMID:10339524

Ruttan, Vernon W.

1999-01-01

125

Phase transition in multiprocessor scheduling.  

PubMed

An "easy-hard" phase transition is shown to characterize the multiprocessor scheduling problem in which one has to distribute the workload on a parallel computer such as to minimize the overall run time. The transition can be analyzed in detail by mapping it on a mean-field antiferromagnetic Potts model. The static phase transition, characterized by a vanishing ground state entropy, corresponds to a transition in the performance of practical scheduling algorithms. PMID:12732079

Bauke, Heiko; Mertens, Stephan; Engel, Andreas

2003-04-18

126

Phase Transition in Multiprocessor Scheduling  

NASA Astrophysics Data System (ADS)

An “easy-hard” phase transition is shown to characterize the multiprocessor scheduling problem in which one has to distribute the workload on a parallel computer such as to minimize the overall run time. The transition can be analyzed in detail by mapping it on a mean-field antiferromagnetic Potts model. The static phase transition, characterized by a vanishing ground state entropy, corresponds to a transition in the performance of practical scheduling algorithms.

Bauke, Heiko; Mertens, Stephan; Engel, Andreas

2003-04-01

127

Precision Photometry for Planetary Transits  

NASA Astrophysics Data System (ADS)

This paper reviews the state of the art in follow-up photometry for planetary transit searches. Three topics are discussed: (1) Photometric monitoring of planets discovered by radial velocity to detect possible transits (2) Follow-up photometry of candidates from photometric transit search to weed out eclipsing binaries and false positives (3) High-precision light curves of known transiting planets to increase the accuracy on the planet parameters.

Pont, F.; Moutou, C.

2007-07-01

128

Transitions 2007: Planning for Retirement  

E-print Network

planning, trusts and wills, and health care instructions? Spouses/Partners welcome to attend! A TransitionsTransitions 2007: Planning for Retirement: Strategies, Options, and Information This one-day Transitions program is designed to provide information and to answer any questions you might have about

Southern California, University of

129

Mass transit and appropriate technology  

Microsoft Academic Search

New mass transit technologies are reviewed, and the importance of fitting the appropriate technology with a particular situation or circumstance is stressed. The new technologies will make mass transit more competitive with private automobiles in the future only if the technologies are applied in proper and corresponding circumstances. In some cases, buses and taxicabs are still the best public transit

Bell

1978-01-01

130

Reconstructing Transition Knowledge in Taiwan  

ERIC Educational Resources Information Center

Taking a post-colonial stand and using school to work transition as an example, the author re-examines the special education discourses in Taiwan and attempts to construct alternate understandings of transition from sociological and cultural perspectives. A review of past transition literature and a survey of the educational background of the…

Cheng, Chen-chen

2012-01-01

131

Certificate in Transit Management and  

E-print Network

." This exciting program includes: - Formal course work in Civil Engineering and the School of Management is a contract carrier for the Pioneer Valley Transit Authority located in Western Massachusetts. The bus system is an operating arm of First Transit a U.S. based private transit management company with more than 51 years

Massachusetts at Amherst, University of

132

[Peruvian demographic transition].  

PubMed

The demographic transition is conceptualized as the historic change from high to low fertility and mortality rates in a population. Peru's population was reduced by an estimated 80% as a result of new diseases, destruction of the economy, and the brutal regime of colonial exploitation after the Spanish conquest. From colonial times to the least the 1940s, Peru's principal population problem was the scarcity of manpower. The population grew at an annual rate of about .03% between 1650 and 1800, increasing to about 1.3% between 1876 and 1940. High fertility throughout the 19th century and a stabilization of mortality due to reduced incidence and deadliness of epidemics contributed to the increased growth rate. In the 1940s the process of demographic transition was initiated by abrupt declines in mortality. The crude death rate declined from 27/1000 in 1940 to 16/1000 in 1961 and 9/1000 in 1988, with the rate still declining. Fertility remained high and possibly increased slightly. The crude birth rate was estimated at 45/1000 in 1940 and 45.4/1000 in 1961. Improvements in infant and general mortality rates in developing countries like Peru result from diffusion of technological advances in prevention and control of diseases and improvement in health services rather than from changes in the economic and social structure. The 3rd phase of the demographic transition began with declines in fertility from 45.4/1000 in 1961 to 42.0/1000 in 1972 and 36.0/1000 in 1981. Despite declines, mortality and fertility continue to be elevated in Peru. The theory of demographic transition views the reduction of infant mortality, improvements in health and educational conditions and the condition of women, and more equitable income distribution as essential for a true decline in birth rates. In Peru, however, fertility has declined in a context of deteriorating living conditions and in the absence of effective family planning programs. The process of demographic transition must be accelerated, which will require improvements in education, income, and availability of sanitary services among other changes. PMID:12315513

Carbajal Chirinos, C

1988-06-01

133

Searching for transit timing variations in transiting exoplanet systems  

E-print Network

Searching for transit timing variations in the known transiting exoplanet systems can reveal the presence of other bodies in the system. Here we report such searches for two transiting exoplanet systems, TrES-1 and WASP-2. Their new transits were observed with the 4.2m William Herschel Telescope located on La Palma, Spain. In a continuing programme, three consecutive transits were observed for TrES-1, and one for WASP-2 during September 2007. We used the Markov Chain Monte Carlo simulations to derive transit times and their uncertainties. The resulting transit times are consistent with the most recent ephemerides and no conclusive proof of additional bodies in either system was found.

Marie Hrudková; Ian Skillen; Chris Benn; Don Pollacco; Neale Gibson; Yogesh Joshi; Petr Harmanec; Simon Tulloch

2008-07-07

134

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

135

Cranklike conformational transitions in polyethylene  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations of a variety of polymeric systems provide the evidence for two different kinds of conformational transitions: independent single bond transitions and cranklike transitions (or correlated bond transitions). While single bond transitions can be rationalized according to standard theories of activated processes controlled by the saddle point crossing, a more complex description is required for the other type of transitions. In a recent work devoted to the analysis of the simplified chain model with three rotors [B. Nigro and G. J. Moro, J. Phys. Chem. B 106, 7365 (2002)], a theory has been proposed for cranklike transitions represented as a kinetic process between equilibrium states differing by two torsional angles (i.e., two bond transitions). Moreover their rate coefficients were estimated on the basis of a local expansion about the bifurcation of the separatrices departing from the potential function maximum. In the present work the same theory is applied to a model for long alkyl chains in solution, in order to rationalize the behavior of cranklike transitions in polyethylene and to recognize the molecular features controlling them. We obtain probabilities of occurrence of cranklike transitions in substantial agreement with simulation results. Furthermore, the theory is capable of explaining the dependence of the rate on the separation between the two reactive bonds, as well as the dependence on the conformational state of the starting configuration. In particular, selection rules for next-to-nearest neighbor transitions are recovered from the shape of the separatrices and the location of the corresponding bifurcations.

Nigro, B.; di Stefano, D.; Rassu, A.; Moro, G. J.

2004-09-01

136

Transition in Turbine Flows  

NASA Technical Reports Server (NTRS)

We have further developed our capabilities to analyze transition in turbine boundary layers from first principles by integrating the nonlinear parabolized stability equations (PSE) with improved initial and boundary conditions. With modified iteration schemes, we are able to proceed deeper into the transition region where skin friction coefficient and heat transfer coefficient significantly increase. Initial and boundary conditions at elevated turbulence levels can be derived by receptivity analysis. Test runs for ERCOFTAC test case T3A at 2.4\\% turbulence level provide results in good agreement with the experimental data. The sharper minimum of the skin coefficient also shown by DNS results is likely due to the missing intermittency. The method has been applied to various experimentally studied turbine blades (UTRC, VKI, Zierke, Langston, Hippensteele, and others). The PSE results, though physically reasonable, do not agree as well as expected with the experimental findings. We have, therefore, performed an extensive search for the reasons of the seemingly systematic deviations. A first source of uncertainty has been found in the often insufficient documentation of the experiments (e.g. on blockage by end-wall boundary layers). However, variation of the relevant parameters does not lead to more satisfactory agreement. A second reason has been found in the "standard procedure" which considers a 2D flow at midspan and uses a panel code and subsequent boundary-layer code to obtain the laminar basic flow for the transition analysis. Comparison with the pressure distribution obtained with a 3D design code (RVC3D) shows significant three-dimensionality of the flow (e.g. in the UTRC experiments). The spanwise variation has been neglected in our original PSE code. To overcome this problem, we have developed the PSE/3D for fully 3D boundary layers to account for streamwise and spanwise variations. Since the design code does not provide the boundary-layer flow with sufficient resolution, we have generated the Euler solution and employed a 3D boundary-layer code to obtain the viscous basic flow. Although only the linear stability level of PSE/3D has been implemented so far, the discrepancies with the experiments change but do not disappear. We still find deviations between the computed and experimental variations of C(sub f), and St along the blade for laminar flow. The main reason can be seen by comparing the solution of the boundary-layer code with the viscous results of the design code. The conventional boundary-layer solution exhibits an asymptotic behavior appropriate in external aerodynamics but does not match the steep gradients of the inviscid flow through the passage and consequently provides biased results for C(sub f), and St. An attempt is currently being made to correct this deficiency. Before attempting to perform the transition analysis for the viscous flow provided by the design code, we have analyzed the implementation and "best possible" results. Code and results exhibit flaws that may negatively affect the design and are intolerable for transition analysis. Therefore, we have decided to develop a new code to obtain a reliable basis for stability and transition studies. We expect to report improved results by the time of the meeting.

Herbert, Thorwald

1998-01-01

137

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 MINEHOUND TM. This detector combines a metal detector with a Ground Penetrating Radar (GPR). As a result of extremely successful trials MINEHOUND TM 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

2007-04-01

138

Transition Metal Switchable Mirror  

SciTech Connect

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

None

2009-01-01

139

36 CFR 219.35 - Transition.  

Code of Federal Regulations, 2011 CFR

...and Transition § 219.35 Transition. (a) The transition period begins on November...the completion of the revision process (§ 219.9) for each unit...Forest System. During the transition period, the...

2011-07-01

140

309 Building transition plan  

SciTech Connect

The preparation for decontamination and decommissioning (transition) of the 309 Building is projected to be completed by the end of the fiscal year (FY) 1998. The major stabilization and decontamination efforts include the Plutonium Recycle Test Reactor (PRTR), fuel storage and transfer pits, Transfer Waste (TW) tanks and the Ion Exchange Vaults. In addition to stabilizing contaminated areas, equipment, components, records, waste products, etc., will be dispositioned. All nonessential systems, i.e., heating, ventilation, and air conditioning (HVAC), electrical, monitoring, fluids, etc., will be shut down and drained/de-energized. This will allow securing of the process, laboratory, and office areas of the facility. After that, the facility will be operated at a level commensurate with its surveillance needs while awaiting D&D. The implementation costs for FY 1995 through FY 1998 for the transition activities are estimated to be $1,070K, $2,115K, $2,939K, and $4,762K, respectively. Costs include an assumed company overhead of 20% and a 30% out year contingency.

Graves, C.E.

1994-08-31

141

Phase transitions in layered crystals  

E-print Network

It is demonstrated by analyzing real examples that phase transitions in layered crystals occur like all other solid-state phase transitions by nucleation and crystal growth, but have a specific morphology. There the nucleation is epitaxial, resulting in the rigorous orientation relationship between the polymorphs, such that the direction of molecular layers are preserved. The detailed molecular mechanism of these phase transitions and formation of the laminar domain structures are described and related to the nature of ferroelectrics.

Yuri Mnyukh

2011-05-22

142

NASA CONNECT: Venus Transit  

NSDL National Science Digital Library

In this program, students learn about the importance of using scale models to represent the size and distance of objects in the Solar System and beyond. They are introduced to the astronomical unit (AU), the baseline distance from the Earth to the Sun, which astronomers use to determine the relative distances from Earth to other planets, stars, asteroids, and objects in space. They also discover facts about the Venus Transit, a celestial and historical event, which helped astronomers determine the scale of the Solar System. Students use measurement, ratios, and graphing to construct a model of the solar system and determine the relationship of each planet to the Sun. They will explore the scales needed to represent the size of the planets and the distances to the Sun.

2004-01-01

143

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

144

The ``Venus Transit Experience''  

NASA Astrophysics Data System (ADS)

On November 5-7, 2004, an unusual conference took place at the French Ministry of Research in Paris. Entitled the “Venus Transit Experience”, this meeting was organised by the VT-2004 International Steering Committee (ISC) and the local arrangements were ably taken care of by the staff of the IMCCE and the Observatoire de Paris, with Jean-Eudes Arlot and William Thuillot at the helm. It brought together more than 150 persons connected to the VT-2004 programme. The aim was to sum up the vast experience gained through this unique public education programme and, in particular, to perform an evaluation of its many components. On the first day, more than 50 students from the Paris areas who participated actively in this programme were also present.

Boffin, H.; West, R.

2004-12-01

145

Hybrid Electric Transit Bus  

NASA Technical Reports Server (NTRS)

A government, industry, and university cooperative is developing an advanced hybrid electric city transit bus. Goals of this effort include doubling the fuel economy compared to current buses and reducing emissions to one-tenth of current EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors as an energy storage system, and a planned natural gas fueled turbogenerator developed from a small jet engine. Power from both the generator and energy storage system is provided to a variable speed electric motor attached to the rear axle. At over 15000 kg gross weight, this is the largest vehicle of its kind ever built using ultra-capacitor energy storage. This paper describes the overall power system architecture, the evolution of the control strategy, and its performance over industry standard drive cycles.

Viterna, Larry A.

1997-01-01

146

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.

147

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

148

Diffusion phase transitions in alloys  

NASA Astrophysics Data System (ADS)

We present a critical analysis of research on the thermodynamics, kinetics, and morphology of diffusion phase transitions in alloys. We show that diffusion phase transitions are mainly driven by the chemical potential difference due to a change in the sign of the chemical interaction among the component atoms. We explain how the sign of the chemical interaction energy can be obtained from experimental measurements. Examples are given to illustrate the kinetics and morphology of the ordering-separation phase transition in Ni- and Co-based alloys. We show how introducing the concept of the ordering-separation phase transition may affect our thinking in this area.

Ustinovshchikov, Yu I.

2014-07-01

149

Transit satellite system timing capabilities  

NASA Technical Reports Server (NTRS)

Current time transfer capabilities of the Transit Satellite System are reviewed. Potential improvements in the changes in equipment and operational procedures using operational satellites are discussed.

Finsod, T. D.

1978-01-01

150

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

151

Presidential Transition Teams: Fostering a Collaborative Transition Process  

ERIC Educational Resources Information Center

Whether hiring a sitting president or one beginning a first presidency, the board of trustees should be keenly interested in ensuring that the new president's first months in office flow as smoothly as possible. Increasing attention has been paid in recent years to the idea of using a transition team to assist the new president. Using a transition

Artman, Richard B.; Franz, Mark

2009-01-01

152

Transitions to Least Restrictive Environments: A Guide to Transition. Revised.  

ERIC Educational Resources Information Center

This guide to the transition of special education students to less restrictive environments or from school to work stresses the importance of planning and communication during the entire process, from initial plans through implementation and follow-up. Section 1 consists of a "Transition Process Checklist" to aid in the organization and follow…

Beninghof, Anne M.

153

Transition Assessment: Using Gap Analysis to Enhance Effective Transition Planning  

ERIC Educational Resources Information Center

Over the past decade, there has been an increased emphasis on transition planning for students with exceptional needs. This is in part the result of the mandates contained in the Individuals with Disabilities Education Improvement Act of 2004. This increased emphasis has revealed a number of shortcomings with how transition planning is done…

Lowenthal, Alison B.; Bassett, Diane S.

2012-01-01

154

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

155

Gauss-Matuyama Polarity Transition  

NASA Astrophysics Data System (ADS)

The Gauss-Matuyama (G-M) polarity transition has been identified in a 9 cm rotary-drilled core from Searles Valley, California. The lithology, recovery and preservation of the sediments allow a detailed investigation of the transition. The transition is estimated to have lasted approximately 2000 years. About 2000 years earlier, a short reversal also occurred that lasted 2000 years. The relative field intensity decreased by at least 70% both during this short reversal and the G-M transition. The virtual geomagnetic poles path for the G-M transition is restricted to a meridional band 20 degrees wide in the Atlantic Ocean and closely matches the v.g.p. path for the Matuyama-Brunhes transition recorded at Lake Tecopa, California. On the other hand, the pole path for the G-M transition recorded in Russia (about 180 degrees in longitude from Searles Valley) is nearly antipodal at low latitudes to the Searles Valley pole path. These data indicate that the transition field associated with the reversal was dominated by non-dipole components. The pole path for the G-M transitionin Searles Valley is confined to a 20 degrees meridional band in the Atlantic Ocean and in the mid-latitudes resides about 180 degrees in longitude from the path recorded in Russia(Burakov et al. 1976). This is strong evidence that the transition field during the reversal was predominantly non-dipolar. 2. The v.g.p. paths for the G-M transition at Searles Valley and the M-B transition at Lake Tecopa, California(Hillhouse & Cox 1976), are very similar. 3. The pole path for the G-M transition at Searles Valley is approximately 90 degrees east of the site longitude, as it is for the Russian localities. Although the Searles Valley path is on the fence separating 'near' from 'far' paths in the hypotheses of Hoffman & Fuller (1978) and Fuller et al. (1979), some uncertainty exists because of the assumption about absolute declination that is used for calculating the v.g.ps. 4. There is more than one reversal during the entire transition, and that pattern was reported for Russia (Burakov er al. 1976). For Searles Valley, the overall duration is estimated at 6000 years; for Russia, the estimate is about 100000 years(Burakov et al. 1976), which seems long in the light of what is known about other transitions(Further et al. 1979). 5. The relative intensity in Searles Valley decreases by about fourfold for the G-M transition. There is a similar reduction during the short reversal that preceded it, and a partial build-up in the intervening 2000 years.

Liddicoat, J. C.

1982-08-01

156

Detection by Transit Photometry  

NASA Technical Reports Server (NTRS)

A periodic sequence of planetary transits provides a valid detection of an orbiting planet and provides the relative size of the planet and its orbital period. Ancillary measurements of the stellar spectrum and the variations of the star's radial velocity or position combined with stellar models allow the absolute size of the planet and its mass to be obtained. The results of this approach have already shown that the planet orbiting HD209458 has only 70% of the mass of Jupiter, but is nearly 50% larger in radius. Based on models of planetary structure, these results imply that the planet must have spent most of its lifetime so close to the star that it has not been able to cool and contract as have the giant planets in our Solar System. Thus its density is much less than Jupiter and Saturn and is actually less than that of water; i.e., about 0.4 gr/cu cm. If more sensitive measurements of the light curve of stars with closely orbiting planets can be made that provide the varying amplitude of the light reflected by the planet at various phases in its orbit, then characteristics of the planetary atmosphere can be obtained. Potentially, these data can identify major molecular species present in the atmosphere and tell us if clouds are present and yield the phase function of the aerosols. Although such detail cannot be obtained for Earth-size planets because their signal amplitudes are too small, it is possible to get data critical to the determination of the structure of extrasolar planetary systems. In particular, the size distributions and their orbital distributions can be measured by the transit photometry missions now in development. The COROT mission should be able to find large terrestrial planets in short-period orbits while the more ambitious Kepler and Eddington missions should be able to detect planets even smaller than the Earth and at orbital distances that place them in the habitable zone of their stars.

Borucki, William J.; Koch, David G.; Jenkins, Jon M.; DeVincenzi, D. (Technical Monitor)

2002-01-01

157

Transition Programs: Bridging the Gap.  

ERIC Educational Resources Information Center

This document shares the collective wisdom and experience of professionals who have successfully guided the transition of hundreds of youths and adults from New York's correctional institutions back into the community. The first section begins with an overview of the New York State Education Department's transition program model to move…

Peavey, Kay

158

Adult Transition Program without Walls  

ERIC Educational Resources Information Center

Best practices in adult transition special education for moderate to severe students suggest student-centered planning that maximizes independence in adult life. Based on the above sources, school districts and governing boards would best serve moderate to severe transition special education students with increasing integration into the community…

Moberg, Eric

2010-01-01

159

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

160

Elaborating transition interface sampling methods  

Microsoft Academic Search

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

Titus S. van. Erp; Peter G.. Bolhuis

2005-01-01

161

Transition Planning for Foster Youth  

ERIC Educational Resources Information Center

The study evaluated the IEPs/Individualized Transition Plans of 45 students who were in special education and foster care, and compared them to the plans of 45 students who were in special education only. Results indicate that the transition plans of foster youth with disabilities were poor in quality, both in absolute terms and in comparison to…

Geenen, Sarah J.; Powers, Laurie E.

2006-01-01

162

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

163

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

164

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

165

Selenophene transition metal complexes  

SciTech Connect

This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the {eta}{sup 5}- and the {eta}{sup 1}(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The {sup 77}Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of {eta}{sup 1}(S)-bound thiophenes, {eta}{sup 1}(S)-benzothiophene and {eta}{sup 1}(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the {eta}{sup 1}(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh{sub 3})Re(2-benzothioenylcarbene)]O{sub 3}SCF{sub 3} was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the {eta}{sup 1}(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

White, C.J.

1994-07-27

166

Temperature-Induced transition  

NASA Astrophysics Data System (ADS)

A nitrogen-strengthened austenitic stainless steel was tested in uniaxial tension at room temperature (295 K) and in liquid nitrogen (76 K). A transition in ductile fracture appearance from a cup-cone fracture at room temperature to shear fracture at cryogenic temperature is observed and correlated to deformation behavior and micromechanisms (void nucleation and strain localization) of fracture. The flow stresses, fracture stresses, and strain hardening rates are all higher at liquid nitrogen temperature compared to those at room temperature, and the significant increases in plastic flow stresses are accompanied by planar deformation mechanisms. At both temperatures, primary void nucleation is observed mainly at scattered, large patches of sigma phase, and initial primary void growth is associated with tensile instability (necking) in the specimen. Postuniform elongation at 295 K leads to secondary void nucleation from small, less than 1 ?m in diameter, microalloy particles, leading directly to failure; the strain required for secondary void growth and coalescence is highly localized and does not contribute to macroscopic elongation. At 76 K, uniform strain increases, total strain decreases, and strain localization into shear bands between the primary voids and the surface of the neck leads directly to failure. Secondary void nucleation, growth, and coalescence are limited to shear bands and also do not contribute to the macroscopic elongation. The observations of void nucleation are characterized in terms of a continuum analysis for the interfacial stress at voidnucleating particles. The critical interfacial stress for void nucleation at the lower temperature correlates with the increased flow properties of the matrix.

Purtscher, P. T.; Krauss, G.; Matlock, D. K.

1993-11-01

167

The Visibility of Earth Transits  

NASA Technical Reports Server (NTRS)

The recent detection of planetary transits of the solar-like star HD 209458 at a distance of 47 parsecs suggest that transits can reveal the presence of Jupiter-size planetary companions in the solar neighborhood. Recent space-based transit searches have achieved photometric precision within an order of magnitude of that required to detect the much smaller transit signal of an earth-size planet around a solar-size star. Laboratory experiments in the presence of realistic noise sources have shown that CCDs can achieve photometric precision adequate to detect the 9.6 E-5 dimming, of the Sun due to a transit of the Earth. Space-based solar irradiance monitoring has shown that the intrinsic variability of the Sun would not preclude such a detection. Transits of the Sun by the Earth would be detectable by observers that reside within a narrow band of sky positions near the ecliptic plane, if the observers possess current Earth epoch levels of technology and astronomical expertise. A catalog of candidate target stars, their properties, and simulations of the photometric Earth transit signal detectability at each target is presented.

Castellano, Tim; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

168

The Visibility of Earth Transits  

NASA Technical Reports Server (NTRS)

The recent photometric detection of planetary transits of the solar-like star HD 209458 at a distance of 47 parsecs suggest that transits can reveal the presence of Jupiter-size planetary companions in the solar neighborhood. Recent space-based transit searches have achieved photometric precision within an order of magnitude of that required to detect the much smaller transit signal of an earth-size planet across a solar-size star. Laboratory experiments in the presence of realistic noise sources have shown that CCDs can achieve photometric precision adequate to detect the 9.6 E-5 dimming of the Sun due to a transit of the Earth. Space-based solar irradiance monitoring has shown that the intrinsic variability of the Sun would not preclude such a detection. Transits of the Sun by the Earth would be detectable by observers that reside within a narrow band of sky positions near the ecliptic plane, if the observers possess current Earth epoch levels of technology and astronomical expertise. A catalog of solar-like stars that satisfy the geometric condition for Earth transit visibility are presented.

Castellano, Timothy P.; Doyle, Laurance; McIntosh, Dawn; DeVincenzi, Donald (Technical Monitor)

2000-01-01

169

Unstable supercritical discontinuous percolation transitions  

NASA Astrophysics Data System (ADS)

The location and nature of the percolation transition in random networks is a subject of intense interest. Recently, a series of graph evolution processes have been introduced that lead to discontinuous percolation transitions where the addition of a single edge causes the size of the largest component to exhibit a significant macroscopic jump in the thermodynamic limit. These processes can have additional exotic behaviors, such as displaying a “Devil's staircase” of discrete jumps in the supercritical regime. Here we investigate whether the location of the largest jump coincides with the percolation threshold for a range of processes, such as Erd?s-Rényipercolation, percolation via edge competition and via growth by overtaking. We find that the largest jump asymptotically occurs at the percolation transition for Erd?s-Rényiand other processes exhibiting global continuity, including models exhibiting an “explosive” transition. However, for percolation processes exhibiting genuine discontinuities, the behavior is substantially richer. In percolation models where the order parameter exhibits a staircase, the largest discontinuity generically does not coincide with the percolation transition. For the generalized Bohman-Frieze-Wormald model, it depends on the model parameter. Distinct parameter regimes well in the supercritical regime feature unstable discontinuous transitions—a novel and unexpected phenomenon in percolation. We thus demonstrate that seemingly and genuinely discontinuous percolation transitions can involve a rich behavior in supercriticality, a regime that has been largely ignored in percolation.

Chen, Wei; Cheng, Xueqi; Zheng, Zhiming; Chung, Ning Ning; D'Souza, Raissa M.; Nagler, Jan

2013-10-01

170

Fluctuation driven electroweak phase transition  

NASA Technical Reports Server (NTRS)

We examine the dynamics of the electroweak phase transition in the early Universe. For Higgs masses in the range 46 less than or = M sub H less than or = 150 GeV and top quark masses less than 200 GeV, regions of symmetric and asymmetric vacuum coexist to below the critical temperature, with thermal equilibrium between the two phases maintained by fluctuations of both phases. We propose that the transition to the asymmetric vacuum is completed by percolation of these subcritical fluctuations. Our results are relevant to scenarios of baryogenesis that invoke a weakly first-order phase transition at the electroweak scale.

Gleiser, Marcelo; Kolb, Edward W.

1991-01-01

171

Theory on instability and transition  

NASA Technical Reports Server (NTRS)

The fundamental fluid dynamics governing instability and transition to turbulence in boundary layers are considered, and attention is focused on the key aspects of nonlinear dynamics central to the transition process and to turbulent boundary-layer phenomena. Emphasis is placed on truly nonlinear theories, in which the boundary layer mean-flow profile is completely altered from its original form. Nonlinear TS transitions, Euler-stage interactions, and vortex/wave interactions are discussed, and compressible boundary layers are analyzed. Connections with experiments and computations are outlined, along with overall trends including the extension of the nonlinear theory and the advancement in the compressible and other flow regimes.

Smith, Frank T.

1990-01-01

172

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

173

33 CFR 401.89 - Transit refused.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Transit refused. 401.89 Section 401... Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not...

2010-07-01

174

42 CFR 136a.31 - Transition period.  

Code of Federal Regulations, 2013 CFR

...AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a) The transition period for full implementation of...grace period; and (3) A health care continuity period determined by...

2013-10-01

175

42 CFR 412.533 - Transition payments.  

Code of Federal Regulations, 2011 CFR

...for Long-Term Care Hospitals § 412.533 Transition payments. (a) Duration of transition periods. Except for a long-term care hospital that...paid under the transition period methodology. A long-term care hospital...

2011-10-01

176

42 CFR 136a.31 - Transition period.  

Code of Federal Regulations, 2010 CFR

...AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a) The transition period for full implementation of...grace period; and (3) A health care continuity period determined by...

2010-10-01

177

42 CFR 136a.31 - Transition period.  

Code of Federal Regulations, 2011 CFR

...AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a) The transition period for full implementation of...grace period; and (3) A health care continuity period determined by...

2011-10-01

178

42 CFR 136a.31 - Transition period.  

Code of Federal Regulations, 2012 CFR

...AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a) The transition period for full implementation of...grace period; and (3) A health care continuity period determined by...

2012-10-01

179

42 CFR 412.533 - Transition payments.  

Code of Federal Regulations, 2013 CFR

...for Long-Term Care Hospitals § 412.533 Transition payments. (a) Duration of transition periods. Except for a long-term care hospital that...paid under the transition period methodology. A long-term care hospital...

2013-10-01

180

42 CFR 412.533 - Transition payments.  

Code of Federal Regulations, 2010 CFR

...for Long-Term Care Hospitals § 412.533 Transition payments. (a) Duration of transition periods. Except for a long-term care hospital that...paid under the transition period methodology. A long-term care hospital...

2010-10-01

181

42 CFR 412.533 - Transition payments.  

Code of Federal Regulations, 2012 CFR

...for Long-Term Care Hospitals § 412.533 Transition payments. (a) Duration of transition periods. Except for a long-term care hospital that...paid under the transition period methodology. A long-term care hospital...

2012-10-01

182

21 December 2007 Light Rail Transit Construction  

E-print Network

21 December 2007 Light Rail Transit Construction Impact Mitigation Strategies: Case Studies and Recommendations for the Central Corridor #12;Light Rail Transit Construction Impact Mitigation Strategies: Case Rail Transit Construction Impact Mitigation Strategies 21 December 2007 i TABLE OF CONTENTS

Levinson, David M.

183

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 ...

184

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 #...

185

Moved by a Rapid Transit  

NASA Astrophysics Data System (ADS)

Enticing by virtue of its predictability, historical utility, and spectacle, the transit of Venus is a niche event among astronomical phenomena. Though the value of a transit for scientific purposes is now diminished, the brief appearance of Venus silhouetted against the background of the Sun in 2004 moved the artistic community to celebrate the rare alignment. Artists of all ages combined old traditions with fresh technology to create a 21st-century tapestry of music, sculpture, paintings, glasswork, quilts, sky shows, and digital imagery. A full catalog of transit-related art generated over the centuries would feature the sampling of entries presented here and at the Moved by a Rapid Transit website.

Bueter, C.

2013-04-01

186

Transition metal nitride functional coatings  

NASA Astrophysics Data System (ADS)

During the past decade, interest in transition metal nitrides has grown considerably. Nitrides of various elements play an important role in industry, science, and technology for their interesting and useful resilient properties. For example, many transition metal nitrides based on titanium, boron, and nitrogen have stimulated commercial interest because of their extreme hardness, wear and corrosion resistance, and thermal and electrical properties. All of these features are enhanced by the resulting structures and the large degree of covalency exhibited by the transition metal-nitride bonds. Coatings of select nitrides may particularly influence physico-chemical properties in critical surface and interface regions. This article attempts to present a brief overview on transition metal-nitride research for advancement in reliable machine part manufacturing.

Navinsek, B.; Seal, Sudipta

2001-09-01

187

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

188

Hurricanes 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.

Comet

2002-05-02

189

Gd Transition Probabilities and Abundances  

Microsoft Academic Search

Radiative lifetimes, accurate to +\\/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of Gd II transition probabilities and the

E. A. Den Hartog; J. E. Lawler; C. Sneden; J. J. Cowan

2006-01-01

190

Sm Transition Probabilities and Abundances  

Microsoft Academic Search

Radiative lifetimes, accurate to +\\/- 5%, have been measured for 212 odd-parity levels of Sm II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier-transform spectrometry to determine transition probabilities for more than 900 lines of Sm II. This work is the largest-scale laboratory study to date of Sm II transition probabilities using modern methods. This

J. E. Lawler; E. A. Den Hartog; C. Sneden; J. J. Cowan

2005-01-01

191

China's Way of Economic Transition  

Microsoft Academic Search

China started economic transition in 1978 to implement a Chinese type of socialist market economy system, i.e., a market-oriented economy consisting of collectively community-owned enterprises (CCOE) and state-owned enterprises (SOE) in a totalitarian political system with the Communist Party of China as the ruling power. The main contents of the economic transition can be briefly described as follows: (1) gradual

John-ren Chen

2005-01-01

192

Transition States, Analogues and Drug Development  

PubMed Central

Enzymes achieve their transition states by dynamic conformational searches on the fsec to psec timescale. Mimics of reactants at enzymatic transition states bind tightly to enzymes by stabilizing the conformation optimized through evolution for transition state formation. Instead of forming the transient transition state geometry, transition state analogues convert the short-lived transition state to a stable thermodynamic state. Enzymatic transition states are understood by combining kinetic isotope effects and computational chemistry. Analogues of the transition state can bind millions of times tighter than substrates and show promise for drug development for several targets. PMID:23259601

Schramm, Vern L.

2013-01-01

193

Modelling the transitional boundary layer  

NASA Technical Reports Server (NTRS)

Recent developments in the modelling of the transition zone in the boundary layer are reviewed (the zone being defined as extending from the station where intermittency begins to depart from zero to that where it is nearly unity). The value of using a new non-dimensional spot formation rate parameter, and the importance of allowing for so-called subtransitions within the transition zone, are both stressed. Models do reasonably well in constant pressure 2-dimensional flows, but in the presence of strong pressure gradients further improvements are needed. The linear combination approach works surprisingly well in most cases, but would not be so successful in situations where a purely laminar boundary layer would separate but a transitional one would not. Intermittency-weighted eddy viscosity methods do not predict peak surface parameters well without the introduction of an overshooting transition function whose connection with the spot theory of transition is obscure. Suggestions are made for further work that now appears necessary for developing improved models of the transition zone.

Narasimha, R.

1990-01-01

194

Boundary layer transition studies  

NASA Technical Reports Server (NTRS)

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. The technique was enhanced by using up to nine multiple probes to reduce the experimental run-time. In both cases, 3D contour surfaces in the vicinity of the hole show highly 3D TS waves which fan out in the spanwise direction forming bow-shaped waves downstream. The case without suction has proved useful for evaluating calculation methods. With suction, the perturbations on the centerline are much stronger and decay less rapidly, while the TS waves in the far field are similar to the case without suction. Downstream, the contour surfaces of the TS waves develop spanwise irregularities which eventually form into clumps. The spanwise clumping is evidence of a secondary instability that could be associated with suction vortices. Designers of porous surfaces use Goldsmith's Criterion to minimize cross-stream interactions. It is shown that partial TS wave cancellation is possible, depending on the hole spacing, disturbance frequency and free-stream velocity. New high-performance Constant Temperature Hot-Wire Anemometers were designed and built, based on a linear system theory analysis that can be extended to arbitrary order. The motivation was to achieve the highest possible frequency reponse while ensuring overall system stability. The performance is equal to or superior to commercially available instruments at about 10% of the cost. Details, such as fabrication drawings and a parts list, have been published to enable the instrument to be construced by others.

Watmuff, Jonathan H.

1995-01-01

195

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

196

Transition boiling heat transfer and the film transition regime  

NASA Astrophysics Data System (ADS)

The Berenson (1960) flat-plate transition-boiling experiment has been recreated with a reduced thermal resistance in the heater, and an improved access to those portions of the transition boiling regime that have a steep negative slope. Tests have been made in Freon-113, acetone, benzene, and n-pentane boiling on horizontal flat copper heaters that have been mirror-polished, 'roughened', or teflon-coated. The resulting data reproduce and clarify certain features observed by Berenson: the modest surface finish dependence of boiling burnout, and the influence of surface chemistry on both the minimum heat flux and the mode of transition boiling, for example. A rational scheme of correlation yields a prediction of the heat flux in what Witte and Lienhard (1982) previously identified as the 'film-transition boiling' region. It is also shown how to calculate the heat flux at the boundary between the pure-film, and the film-transition, boiling regimes, as a function of the advancing contact angle.

Ramilison, J. M.; Lienhard, J. H.

1987-08-01

197

UV transition moments of tyrosine.  

PubMed

To assist polarized-light spectroscopy for protein-structure analysis, the UV spectrum of p-cresol, the chromophore of tyrosine, was studied with respect to transition moment directions and perturbation by solvent environment. From linear dichroism (LD) spectra of p-cresol aligned in stretched matrices of poly(vinyl alcohol) and polyethylene, the lowest ?-?* transition (Lb) is found to have pure polarization over its entire absorption (250-300 nm) with a transition moment perpendicular to the symmetry axis (C1-C4), both in polar and nonpolar environments. For the second transition (La), polarized parallel with the symmetry axis, a certain admixture of intensity with orthogonal polarization is noticed, depending on the environment. While the Lb spectrum in cyclohexane shows a pronounced vibrational structure, it is blurred in methanol, which can be modeled as due to many microscopic polar environments. With the use of quantum mechanical (QM) calculations, the transition moments and solvent effects were analyzed with the B3LYP and ?B97X-D functionals in cyclohexane, water, and methanol using a combination of implicit and explicit solvent models. The blurred Lb band is explained by solvent hydrogen bonds, where both accepting and donating a hydrogen causes energy shifts. The inhomogeneous solvent-shift sensitivity in combination with robust polarization can be exploited for analyzing tyrosine orientation distributions in protein complexes using LD spectroscopy. PMID:25020040

Fornander, Louise H; Feng, Bobo; Beke-Somfai, Tamás; Nordén, Bengt

2014-08-01

198

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

199

Glass transition dynamics in water and other tetrahedral liquids: 'order disorder' transitions versus 'normal' glass transitions  

NASA Astrophysics Data System (ADS)

We review some aspects of the confusion concerning the glass transition in water, and then show that it must be of a quite different character from that in other molecular liquids, and in fact is the kinetically controlled part of a classical order-disorder transition. (This is the conclusion reached in a review of the low temperature phenomenology of amorphous water currently being published in Science by the present author. Material that would normally appear in the present abbreviated paper will appear in the Science article to which the interested reader is referred.) We do this using a combination of (i) thermodynamic reasoning for 'bulk' water (based on known properties of supercooled water and nearly glassy water), and (ii) direct measurements on nanoscopic (non-crystallizing) water. Both require the heat capacity to be sharply peaked near 220 K and thus to imply the existence of a 'strong-to-fragile' transition during heating. Both require the excess heat capacity to drop to near-vanishing values in the vicinity of 130-150 K. The similarity to order-disorder transitions in crystalline solids is noted, the relation to the second critical point scenario for water is discussed, and the modelling of the anomaly by current theories is considered. Finally we argue that water, with its fragile-to-strong liquid transition below the melting point, links (lies in between) the extremes of classical network liquids (where this transition occurs only above the experimentally accessible range) and fragile molecular liquids, where the fragile-to-strong transition is pushed beneath the glass temperature.

Angell, C. Austen

2007-05-01

200

Spin Transitions in Mantle Minerals  

NASA Astrophysics Data System (ADS)

Mantle minerals at shallow depths contain iron in the high-spin electronic state. The crystal-field splitting energy increases with increasing pressure, which can favor the low-spin state. Hence, pressure-driven transitions from the high-spin to the low-spin state were proposed as early as the 1960s, and minerals in the lower mantle were suggested to contain iron in the low-spin state. Only in the past 10 years did experiments and calculations prove that iron in mantle minerals transforms from high-spin to low-spin at lower-mantle pressures. This transition has important consequences for volume, thermodynamics, and bonding. In a geophysical framework, the transition would affect the dynamics and thermochemical state of the lower mantle, through combined effects on density, elasticity, element partitioning, and transport properties. These observations provide the basis for a new paradigm of the physics and chemistry in Earth's lower(most) mantle.

Badro, James

2014-05-01

201

Phase transitions in quantum chromodynamics  

SciTech Connect

The current understanding of finite-temperature phase transitions in QCD is reviewed. A critical discussion of refined phase-transition criteria in numerical lattice simulations and of analytical tools going beyond the mean-field level in effective continuum models for QCD is presented. Theoretical predictions about the order of the transitions are compared with possible experimental manifestations in heavy-ion collisions. Various places in phenomenological descriptions are pointed out where more reliable data for QCD{close_quote}s equation of state would help in selecting the most realistic scenario among those proposed. Unanswered questions are raised about the relevance of calculations that assume thermodynamic equilibrium. Promising new approaches for implementing nonequilibrium aspects of the thermodynamics of heavy-ion collisions are described. {copyright} {ital 1996 The American Physical Society.}

Meyer-Ortmanns, H. [Institut fuer Theoretische Physik, Universitaet Heidelberg, D-69120 Heidelberg (Germany)] [Institut fuer Theoretische Physik, Universitaet Heidelberg, D-69120 Heidelberg (Germany)

1996-04-01

202

Marital transitions and mental health.  

PubMed

Most research identifies marital disruption as a precursor for poor mental health but is generally unable to discount the potential selection effect of poor mental health leading to marital disruption. We use data from nine annual waves of the British Household Panel Survey to examine social selection and social causation as competing explanations. Mental health is measured using the general health questionnaire. We examine mental health at multiple time points prior to and after a marital transition through separation or divorce and compare this process to those who experience widowhood. All groups transitioning out of marriage have a higher prevalence of poor mental health afterwards but for those separated or divorced, poor mental health also precedes marital disruption, lending support to both social-causation and social-selection processes. The processes both preceding and after the transition to widowhood differ, with increased prevalence of disorder centering around the time surrounding the death itself PMID:15305757

Wade, Terrance J; Pevalin, David J

2004-06-01

203

Quantum Transition-State Theory  

E-print Network

This dissertation unifies one of the central methods of classical rate calculation, `Transition-State Theory' (TST), with quantum mechanics, thereby deriving a rigorous `Quantum Transition-State Theory' (QTST). The resulting QTST is identical to ring polymer molecular dynamics transition-state theory (RPMD-TST), which was previously considered a heuristic method, and whose results we thereby validate. The key step in deriving a QTST is alignment of the flux and side dividing surfaces in path-integral space to obtain a quantum flux-side time-correlation function with a non-zero $t\\to 0_+$ limit. We then prove that this produces the exact quantum rate in the absence of recrossing by the exact quantum dynamics, fulfilling the requirements of a QTST. Furthermore, strong evidence is presented that this is the only QTST with positive-definite Boltzmann statistics and therefore the pre-eminent method for computation of thermal quantum rates in direct reactions.

Hele, Timothy J H

2014-01-01

204

Alternative approaches to fertility transition.  

PubMed

"Using anomalies of the Italian case as the basis, the aim of this article is to verify how the theoretical framework [of demographic transition] put forward by Lesthaeghe can be interpreted.... While the changes in mores in the Italy of the economic boom were a component of the large-scale processes of secularization, rationalization and modernization specific to the [first demographic transition], the practices, values and models of the collective imagination characterizing the second phase of Lesthaeghe's [second demographic transition] are marked by a state of mind that cannot be put down to the 'spirit of the age' during the years of large-scale modernization, but to the emancipatory and 'rational' falling away of many of the barriers to the unfolding of individual life destiny over and above that based on class, gender and age." PMID:12291784

Micheli, G A

1995-01-01

205

Phase transition in black holes  

E-print Network

The present thesis is devoted towards the study of various aspects of the phase transition phenomena occurring in black holes defined in an Anti-de-Sitter (AdS) space. Based on the fundamental principles of thermodynamics and considering a grand canonical framework we examine various aspects of the phase transition phenomena occurring in AdS black holes. We analytically check that this phase transition between the smaller and larger mass black holes obey Ehrenfest relations defined at the critical point and hence confirm a second order phase transition. This include both the rotating and charged black holes in Einstein gravity. Apart from studying these issues, based on a canonical framework, we also investigate the critical behavior in charged AdS black holes. The scaling laws for these black holes are found to be compatible with the static scaling hypothesis. Finally, based on the usual framework of AdS/CFT duality, we investigate the phase transition phenomena occurring in charged hairy black holes defined in an asymptotically AdS space. Based on analytic calculations, and using the AdS/CFT dictionary, we explicitly compute the order-parameter for the dual CFT close to the critical point of the phase transition and found that the critical exponent associated with the condensation is $\\frac{1}{2}$, which is the universal result of the mean field theory. Moreover, we also find that in the presence of an external magnetic field, the dual CFT exhibit a perfect diamagnetism at low temperatures, which may be regarded as the reminiscent of the so called Meissner effect.

Dibakar Roychowdhury

2014-03-18

206

Phase transition in porous electrodes.  

PubMed

It is shown by Monte Carlo simulation that electrochemical thermodynamics of electrolytes in a porous electrode is qualitatively different from that in the bulk with a planar electrode. In particular, first order phase transitions occur in porous electrodes when the pore size is comparable to the ion size of the electrolytes: as the voltage is increased from zero, the surface charge density and the ion density in the porous electrodes discontinuously change at a specific voltage. The critical points for those phase transitions are identified. PMID:21513411

Kiyohara, Kenji; Sugino, Takushi; Asaka, Kinji

2011-04-21

207

Epigenetic switches and network transitions  

NASA Astrophysics Data System (ADS)

We investigate dynamics of gene networks which are regulated by both the fast binding/unbinding of transcription factors to/from DNA and the slow processes of chromatin structural change or histone modification. This heterogeneous dynamics consisting of different time scales is analyzed by the mean-field approximation and the stochastic simulation to show that the network exhibits multiple metastable states and is characterized by transitions among them. We discuss distribution and fluctuation of states of the core gene network of embryonic stem cells as an example of such heterogeneous dynamics and the simulated transitions are compared with the experimental data on the distribution of stem cell states.

Sasai, Masaki

2012-02-01

208

Dewetting Transitions in Protein Cavities *  

PubMed Central

In a previous analysis of the solvation of protein active sites, a drying transition was observed in the narrow hydrophobic binding cavity of Cox-2. With the use of a crude metric that often seems able to discriminate those protein cavities that dry from those that do not, we made an extensive search of the pdb, and identified five other proteins that, in molecular dynamics simulations, undergo drying transitions in their active sites. Because such cavities need not desolvate before binding hydrophobic ligands they often exhibit very large binding affinities. This paper gives evidence that drying in protein cavities is not unique to Cox-2. PMID:20225258

Young, Tom; Hua, Lan; Huang, Xuhui; Abel, Robert; Friesner, Richard; Berne, B. J.

2010-01-01

209

Finding Transition Pathways on Manifolds  

E-print Network

We consider noise-induced transition paths in randomly perturbed dynami- cal systems on a smooth manifold. The classical Freidlin-Wentzell large devia- tion theory in Euclidean spaces is generalized and new forms of action functionals are derived in the spaces of functions and the space of curves to accommodate the intrinsic constraints associated with the manifold. Numerical meth- ods are proposed to compute the minimum action paths for the systems with constraints. The examples of conformational transition paths for a single and double rod molecules arising in polymer science are numerically investigated.

Tiejun Li; Xiaoguang Li; Xiang Zhou

2014-08-13

210

Sustainability Transitions as new perspective  

NASA Astrophysics Data System (ADS)

Sustainability transitions are radical transformations towards a sustainable society as a response to a number of persistent problems confronting contemporary modern societies. The most striking example of such a persistent problem is the current economic and financial crisis. This crisis is only a symptom of a deeper-lying systems crisis, which is rooted in the disbalance between overly consuming and producing during the last decennia on the one hand and exhausting our natural resources and materials on the other hand. The perverse effects of this disbalance are not accounted for in the economic order that we have created. This means that the economic order is not sustainable in the long run. Without a fundamental shift, a transition, to a new, sustainable economy, we will revert to old patterns and mechanisms that will automatically generate the next crises. In this transition process we are at a turning point. On the verge of a new era, characterized by a battle of the old paradigm against the new one, with a crucial role for sustainable innovation. Such a transition perspective might help to unravel the unprecedented complexity of the interrelated economic, financial, energy and climate crisis and to shed some light on structural, sustainable solutions.

Rotmans, J.

2012-04-01

211

Career Transitions: The Australian Experience.  

ERIC Educational Resources Information Center

This book is designed to aid career counselors in Australia help their clients search for enhanced well-being in their occupations and to help organizations and human resource staff members dealing with employees' career development. The book is organized in four parts. Parts 1 and 2 explore the career transition journey that a typical person…

Stevens, Paul

212

Menopause: A Life Cycle Transition.  

ERIC Educational Resources Information Center

Family therapists need to address the issue of menopause proactively to be of benefit to couples and families during this transitional period in the family life cycle. Physical, psychological, and psychosocial factors affecting the menopausal woman and her family, and ways to address these issues in counseling are discussed. (Author/EMK)

Evarts, Barbara Kess; Baldwin, Cynthia

1998-01-01

213

Understanding Student Veterans in Transition  

ERIC Educational Resources Information Center

In this research report the author details a phenomenological study documenting identity development in student veterans making the transition from active military service to higher education. This study took place at a doctoral granting proprietary university with a significant veteran population and consisted of in-depth interviews. This…

Jones, Kevin C.

2013-01-01

214

Controlled quantum evolutions and transitions  

Microsoft Academic Search

We study the nonstationary solutions of Fokker-Planck equations associated to either stationary or non stationary quantum states. In particular, we discuss the stationary states of quantum systems with singular velocity fields. We introduce a technique that allows arbitrary evolutions ruled by these equations to account for controlled quantum transitions. As a first signficant application we present a detailed treatment of

Nicola Cufaro Petroni; Salvatore De Martino; Silvio De Siena; Fabrizio Illuminati

1999-01-01

215

The Nature of Transition Blazars  

NASA Astrophysics Data System (ADS)

Blazars are classically divided into the BL Lacertae (BLL) and flat-spectrum radio quasar (FSRQ) subclasses, corresponding to radiatively inefficient and efficient accretion regimes, respectively, largely based on the equivalent width (EW) of their optical broad emission lines (BELs). However, EW-based classification criteria are not physically motivated, and a few blazars have previously "transitioned" from one subclass to the other. We present the first systematic search for these transition blazars in a sample of 602 unique pairs of repeat spectra of 354 blazars in the Sloan Digital Sky Survey, finding six clear cases. These transition blazars have bolometric Eddington ratios of ~0.3 and low-frequency synchrotron peaks, and are thus FSRQ-like. We show that the strong EW variability (up to an unprecedented factor of >60) is due to swamping of the BELs from variability in jet continuum emission, which is stronger in amplitude and shorter in timescale than typical blazars. Although these transition blazars appear to switch between FSRQ and BLL according to the phenomenologically based EW scheme, we show that they are most likely rare cases of FSRQs with radiatively efficient accretion flows and especially strongly beamed jets. These results have implications for the decrease of the apparent BLL population at high redshifts, and may lend credence to claims of a negative BLL redshift evolution.

Ruan, J. J.; Anderson, S. F.; Plotkin, R. M.; Brandt, W. N.; Burnett, T. H.; Myers, A. D.; Schneider, D. P.

2014-12-01

216

Helping International Students With Transitions  

E-print Network

Helping International Students With Transitions And Culture Shock January 13th 2011 By Helen · Change of Food · Psychological · Physical · Emotional · Being out of "we " mode #12;What Counselling Can provide · Listening · Expressing loss and sorrow · Helping students be imaginative and creative · Advice

Stevenson, Mark

217

Non-equilibrium phase transitions  

Microsoft Academic Search

These lecture notes give a basic introduction to the physics of phase transitions under non-equilibrium conditions. The notes start with a general introduction to non-equilibrium statistical mechanics followed by four parts. The first one discusses the universality class of directed percolation, which plays a similar role as the Ising model in equilibrium statistical physics. The second one gives an overview

Haye Hinrichsen

2006-01-01

218

Managing transitions an anthropological perspective  

E-print Network

; · Rituals are often (invariably?) politically charged ... #12;Student journey ("life-cycle") · Leaving home, school/college, home town, partners, family, social networks; · Gap years; · Fresher's week; · ExamManaging transitions ­ an anthropological perspective on student rites of passages Willy Kitchen

Stevenson, Mark

219

Transiting Exoplanet Survey Satellite (TESS)  

NASA Technical Reports Server (NTRS)

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. A large fraction of TESS target stars will be 30-100 times brighter than those observed by Kepler satellite, and therefore TESS . planets will be far easier to characterize with follow-up observations. TESS will make it possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for observation with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS data will be released with minimal delay (no proprietary period), inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the very nearest and brightest main-sequence stars hosting transiting exoplanets, thus providing future observers with the most favorable targets for detailed investigations.

Ricker, G. R.; Clampin, M.; Latham, D. W.; Seager, S.; Vanderspek, R. K.; Villasenor, J. S.; Winn, J. N.

2012-01-01

220

Microgravity Flow Regime Transition Modeling  

E-print Network

-phase research, a fundamental understanding of two-phase systems can be obtained and applied to both terrestrial systems in space applications. Physically based bubbly-bubbly/slug and bubbly/slug-slug flow regime transition models are introduced in this study...

Shephard, Adam M.

2010-07-14

221

Transitioning to 12-hour shifts  

Microsoft Academic Search

In 1989, Yankee Rowe nuclear power station successfully implemented a 12-hour shift schedule for all shiftworkers (control room personnel, auxiliary operators, and radiation protection shift technicians) with many positive effects on morale, motivation, and performance. The transition from an 8-hour to a 12-hour shift schedule was initiated, organized, and promoted by the shiftworkers themselves after they had identified numerous inadequacies

P. S. Suter; S. M. Cervassi

1993-01-01

222

Leadership Transitions during Fundraising Campaigns  

ERIC Educational Resources Information Center

Capital campaigns are intense efforts to build the financial assets of an institution in a specified amount of time. This study provides an empirical view of how changes in leadership affected concomitant capital campaigns at ten colleges and universities. The transitions during these 10 campaigns influenced morale on campus, altered timing of the…

Nehls, Kimberly

2012-01-01

223

Meeting Special Challenges in Transitions  

ERIC Educational Resources Information Center

The transitions from an elementary school to a middle level school and from a middle level school to a high school are major stepping-stones in the lives of young adolescents and their parents. These times are characterized by changes in school expectations and practices--changes that are often amplified when special education issues are thrown…

Kinney, Patti

2006-01-01

224

Transition Cow: Interaction with Fertility  

Microsoft Academic Search

In recent years a progressive worsening of fertility indices in dairy cow herds has been observed. Several factors (genetic, dietary and management) seem to be more related to poor fertility than milk yield level. The degree and the length of the energy deficit during the transition period are inversely related to reproductive indices (e.g. conception rate is < 30% for

A. Formigoni; E. Trevisi

2003-01-01

225

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

226

Transition metals in plant photosynthesis.  

PubMed

Transition metals are involved in essential biological processes in plants since they are cofactors of metalloproteins and also act as regulator elements. Particularly, plant chloroplasts are organelles with high transition metal ion demand because metalloproteins are involved in the photosynthetic electron transport chain. The transition metal requirement of photosynthetic organisms greatly exceeds that of non-photosynthetic organisms, and either metal deficiency or metal excess strongly impacts photosynthetic functions. In chloroplasts, the transition metal ion requirement needs a homeostasis network that strictly regulates metal uptake, chelation, trafficking and storage since under some conditions metals cause toxicity. This review gives an overview of the current understanding of main features concerning the role of copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) in plant photosynthesis as well as the mechanisms involved in their homeostasis within chloroplasts. The metalloproteins functioning in photosynthetic proteins of plants as well as those proteins participating in the metal transport and metal binding assembly are reviewed. Furthermore, the role of nickel (Ni) in artificial photosynthesis will be discussed. PMID:23739807

Yruela, Inmaculada

2013-09-01

227

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

228

Wildfire Policy in Transition Yellowstone  

E-print Network

Wildfire Policy in Transition 1910 #12;Yellowstone 1988 #12;Colorado South Canyon Fire 1994 #12;Forest Change #12;Condition Class #12;What's At Risk #12;2000 #12;Managing the Impact of Wildfires on Communities and the Environment A Report to the President In Response to the Wildfires of 2000 #12;What

229

Discover Engage Measuring Rail Transit's  

E-print Network

Discover · Engage · Transform Measuring Rail Transit's Sustainability Goals: A Before-A:er, Experimental-Control EvaluaBon of Los Angeles' Expo Light Rail Line Angeles' rail transforma@on · Six new lines opening between 2012 and 2020 · Expo

California at Davis, University of

230

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

231

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...

232

Opacity Generalised to Transition Systems  

Microsoft Academic Search

Recently, opacity has proved to be a promising technique for describing security properties. Much of the work has been couched in terms of Petri nets. Here, we extend the notion of opacity to the model of labelled transition systems and generalise opacity in order to bet- ter represent concepts from the work on information o w. In particular, we establish

Jeremy W. Bryans; Maciej Koutny; Laurent Mazaré; Peter Y. A. Ryan

2005-01-01

233

Dynamic Phase Transitions in PVT Systems  

E-print Network

The main objective of this article are two-fold. First, we introduce some general principles on phase transition dynamics, including a new dynamic transition classification scheme, and a Ginzburg-Landau theory for modeling equilibrium phase transitions. Second, apply the general principles and the recently developed dynamic transition theory to study dynamic phase transitions of PVT systems. In particular, we establish a new time-dependent Ginzburg-Landau model, whose dynamic transition analysis is carried out. It is worth pointing out that the new dynamic transition theory, along with the dynamic classification scheme and new time-dependent Ginzburg Landau models for equilibrium phase transitions can be used in other phase transition problems, including e.g. the ferromagnetism and superfluidity, which will be reported elsewhere. In addition, the analysis for the PVT system in this article leads to a few physical predications, which are otherwise unclear from the physical point of view.

Tian Ma; Shouhong Wang

2007-12-21

234

Premelting transition in uranium dioxide  

SciTech Connect

Thermal analysis of the cooling curves of small samples of UO[sub 2[+-]x] -- initially laser heated (in a high-pressure autoclave to inhibit evaporation) on a sub-second time scale to temperatures just below their melting points [T[sub m](x)] -- reveals, in the case of nominally stoichiometric UO[sub 2.00], a significant, [lambda]-like, heat capacity [C[sub p](T)] peak near 2,670 K; the cooling curves of samples exposed to a reducing environment, on the other hand, exhibit undercooling, characteristic of a first-order phase transition, while under oxidizing conditions it is found that the premelting transition readily disappears. These findings confirm Bredig's original prediction of a premelting transition in this material, in common with that found in other (nonactinide) fluorites near 0.85T[sub m]. A simple model is presented in terms of which the observed behavior can be rationalized. The model is based on the hypothesis that the premelting transition is due to Frenkel disordering of the oxygen sublattice-a process which is rendered cooperative by attractive interactions between complementary Frenkel defects (oxygen interstitials and vacancies); these interactions are treated in a [open quotes]mean-field[close quotes] approximation. The quantitative degree of maximum disorder (realized just above the transition) is, on the other hand, controlled by repulsive interactions between like defects -- the inclusion of which, solely through their effect on the configurational entropy, satisfactorily reproduces the values inferred from recent high-temperature neutron diffraction experiments. 20 refs., 16 figs., 3 tabs.

Hiernaut, J.P.; Ronchi, C. (European Inst. for Transuranium Elements, Karlsruhe (Germany)); Hyland, G.J. (Univ. of Warwick, Coventry (United Kingdom))

1993-03-01

235

Transition  

E-print Network

must. I study their faces in the shadows: innocent, fearful, wanting comfort. What kind of a life have I given them? Too many inconsistencies. How will they cope? Sort out? Make value judgments? I teach the concept of Idic?they observe... for their young minds to cope with. Yet I do them an injustice: They do cope. And what of conditions within our cell? Jamie, Len, and Mandy have two parents. Susan bows to my wishes, for the most part. Our disagreements are few, albeit explosive. She...

Welling, Lois

1982-01-01

236

Transitions between two pictorial attractors.  

PubMed

Two experiments exploring similarity judgments on pairs and triplets of stimuli drawn from pictorial series are described. The stimuli are the Man-Woman and Gypsy-Girl pictures that slowly change from one prototype to the other as one progresses along the series. These have been used previously to demonstrate hysteresis of category judgments on ambiguous figures; the Man Woman series has been both modelled as a problem in neural network theory and mapped onto part of a cusp catastrophe surface. It. is shown that the transition process is complicated with a zone of uncertainty and prevalence of bimodality in many of the pairwise similarity judgments. The dynamics are interpreted in terms of transitions between two saddle-node attractors that are themselves not a discrete pair but have some overlap in their composition. PMID:14683617

Gregson, Robert A M

2004-01-01

237

Transition Radiation in QCD matter  

E-print Network

In ultrarelativistic heavy ion collisions a finite size QCD medium is created. In this paper we compute radiative energy loss to zeroth order in opacity by taking into account finite size effects. Transition radiation occurs on the boundary between the finite size medium and the vacuum, and we show that it lowers the difference between medium and vacuum zeroth order radiative energy loss relative to the infinite size medium case. Further, in all previous computations of light parton radiation to zeroth order in opacity, there was a divergence caused by the fact that the energy loss is infinite in the vacuum and finite in the QCD medium. We show that this infinite discontinuity is naturally regulated by including the transition radiation.

Magdalena Djordjevic

2005-12-22

238

Venus transits - A French view  

NASA Astrophysics Data System (ADS)

After a careful study of Mars observations obtained by Tycho Brahé (1546-1601), Kepler (1571-1630) discovered the now-called Kepler's third law. In 1627 he published his famous Tabulae Rudolphinae, a homage to his protector Rudolph II (1552-1612), tables (Kepler 1609, 1627) from which he predicted Mercury and Venus transits over the Sun. In 1629 Kepler published his Admonitio ad Astronomos Advertisement to Astronomers (Kepler 1630), Avertissement aux Astronomes in French Au sujet de phénomènes rares et étonnants de l'an 1631: l'incursion de Vénus et de Mercure sur le Soleil. This was the beginning of the interest of French astronomers, among many others, in such transits, mostly for Venus, the subject of this paper in which dates are given in the Gregorian calendar.

Débarbat, Suzanne

2005-04-01

239

45 CFR 618.230 - Transition plans.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Transition plans. 618.230 Section 618...Welfare (Continued) NATIONAL SCIENCE FOUNDATION NONDISCRIMINATION...Coverage § 618.230 Transition plans. (a) Submission of plans. An institution to...

2013-10-01

240

45 CFR 618.230 - Transition plans.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Transition plans. 618.230 Section 618...Welfare (Continued) NATIONAL SCIENCE FOUNDATION NONDISCRIMINATION...Coverage § 618.230 Transition plans. (a) Submission of plans. An institution to...

2011-10-01

241

45 CFR 618.230 - Transition plans.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Transition plans. 618.230 Section 618...Welfare (Continued) NATIONAL SCIENCE FOUNDATION NONDISCRIMINATION...Coverage § 618.230 Transition plans. (a) Submission of plans. An institution to...

2012-10-01

242

Strategies for transition to postsecondary educational settings  

E-print Network

The article focuses on the transition of students with learning disabilities (LDs) from high school to postsecondary education. The process of a student's transition from high school is described. Social, psychological, and economic benefits...

Mellard, Daryl

2005-05-01

243

Resolution requirements for numerical simulations of transition  

NASA Technical Reports Server (NTRS)

The resolution requirements for direct numerical simulations of transition to turbulence are investigated. A reliable resolution criterion is determined from the results of several detailed simulations of channel and boundary-layer transition.

Zang, Thomas A.; Krist, Steven E.; Hussaini, M. Yousuff

1989-01-01

244

45 CFR 149.105 - Transition provision.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Transition provision. 149.105 Section 149...SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE EARLY... Reinsurance Amounts § 149.105 Transition provision. For a certified...

2012-10-01

245

45 CFR 149.105 - Transition provision.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Transition provision. 149.105 Section 149...SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE EARLY... Reinsurance Amounts § 149.105 Transition provision. For a certified...

2010-10-01

246

45 CFR 149.105 - Transition provision.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Transition provision. 149.105 Section 149...SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE EARLY... Reinsurance Amounts § 149.105 Transition provision. For a certified...

2013-10-01

247

45 CFR 149.105 - Transition provision.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Transition provision. 149.105 Section 149...SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE EARLY... Reinsurance Amounts § 149.105 Transition provision. For a certified...

2011-10-01

248

11 CFR 300.12 - Transition rules.  

Code of Federal Regulations, 2012 CFR

...false Transition rules. 300.12 Section 300.12 Federal Elections FEDERAL ELECTION COMMISSION BIPARTISAN CAMPAIGN REFORM ACT OF 2002-(BCRA) REGULATIONS NON-FEDERAL FUNDS National Party Committees § 300.12 Transition rules....

2012-01-01

249

Steps Toward a Successful Transition to  

E-print Network

Steps Toward a Successful Transition to No-Till Sjoerd W. Duiker Soil Management Specialist, Penn, the Pennsylvania State Conservation Commission. #12;The no-till revolution .................................................................................. 3 Planning the transition to no-till

Kaye, Jason P.

250

45 CFR 1634.10 - Transition provisions.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Transition provisions. 1634.10 Section 1634...GRANTS AND CONTRACTS § 1634.10 Transition provisions. (a) When the competitive bidding process results in the award of a grant...

2010-10-01

251

45 CFR 1634.10 - Transition provisions.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Transition provisions. 1634.10 Section 1634...GRANTS AND CONTRACTS § 1634.10 Transition provisions. (a) When the competitive bidding process results in the award of a grant...

2011-10-01

252

43 CFR 1610.8 - Transition period.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Transition period. 1610.8 Section...Management Planning § 1610.8 Transition period. (a) Until...without any further analysis or processes included in this subpart...planning analysis, using the process described in §...

2011-10-01

253

18 CFR 5.31 - Transition provision.  

Code of Federal Regulations, 2011 CFR

... 1 2011-04-01 2011-04-01 false Transition provision. 5.31 Section 5.31 Conservation...FEDERAL POWER ACT INTEGRATED LICENSE APPLICATION PROCESS § 5.31 Transition provision. This part shall apply to...

2011-04-01

254

18 CFR 5.31 - Transition provision.  

Code of Federal Regulations, 2010 CFR

... 1 2010-04-01 2010-04-01 false Transition provision. 5.31 Section 5.31 Conservation...FEDERAL POWER ACT INTEGRATED LICENSE APPLICATION PROCESS § 5.31 Transition provision. This part shall apply to...

2010-04-01

255

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

256

Biodiesel Mass Transit Demonstration. Final Report.  

National Technical Information Service (NTIS)

The Biodiesel Mass Transit Demonstration report is intended for mass transit decision makers and fleet managers considering biodiesel use. This is the final report for the demonstration project implemented by the National Biodiesel Board under a grant fro...

2010-01-01

257

Isoconversion Analysis of the Glass Transition  

NASA Astrophysics Data System (ADS)

At temperatures below their glass transition temperatures (Tgs), glass forming materials deviate from equilibrium density and form a glass. The kinetic nature of the glass transition process is manifested in the cooling rate dependence of the glass transition temperature and by structural relaxation below Tg. Various facets of the glass transition kinetics have been well described by phenomenological models of the glass transition, such as the TNM and KAHR model. An important yet frequently questioned assumption in these models is that the apparent activation energy, which describes the temperature dependence of the relaxation time, does not vary during the glass transition process. Some recent reports suggest that the activation energy varies significantly during the glass transition process. In this work we apply an isoconversion analysis to data in the glass transition region which was obtained on cooling from capillary dilatometry and differential scanning calorimetry (DSC) in order to determine whether the apparent activation energy increases as the glassy state is approached.

Badrinarayanan, Prashanth; Zheng, Wei; Simon, Sindee

2007-03-01

258

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

259

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

260

Transition to Modern Number Theory  

Microsoft Academic Search

This chapter establishes Gauss’s Law of Quadratic Reciprocity, the theory of binary quadratic forms, and Dirichlet’s Theorem\\u000a on primes in arithmetic progressions.\\u000a \\u000a Section 1 outlines how the three topics of the chapter occurred in natural sequence and marked a transition as the subject\\u000a of number theory developed a coherence and moved toward the kind of algebraic number theory that is

Anthony Knapp

261

Transiting Exoplanet Survey Satellite (TESS)  

NASA Astrophysics Data System (ADS)

The Transiting Exoplanet Survey Satellite (TESS ) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with IC (approximately less than) 13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every four months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations.

Ricker, George R.; Winn, Joshua N.; Vanderspek, Roland; Latham, David W.; Bakos, Gáspár. Á.; Bean, Jacob L.; Berta-Thompson, Zachory K.; Brown, Timothy M.; Buchhave, Lars; Butler, Nathaniel R.; Butler, R. Paul; Chaplin, William J.; Charbonneau, David; Christensen-Dalsgaard, Jørgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E. W.; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J.; Howard, Andrew W.; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John A.; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M.; Lin, Douglas; Lissauer, Jack J.; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P. R.; Morton, Timothy D.; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S. A.; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G.; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel

2014-08-01

262

Rheological Transition in Granular Media  

Microsoft Academic Search

\\u000a The planar shearing of a two-dimensional system of bidisperse, non-cohesive discs at constant shear velocity is simulated\\u000a using Contact Dynamics. The granular medium is confined between two parallel walls, which are pushed inwards by constant normal\\u000a forces. The flow as a function of the shear velocity shows characteristics of a first order phase transition. The order parameter,\\u000a the center of

Zahra Shojaaee; Lothar Brendel; Dietrich E. Wolf

263

Mass transit and appropriate technology  

Microsoft Academic Search

Population pressures, dwinding fossil-fuel reserves, and new technological developments will make mass transet more and more competitive with private automobiles in the future. But future transit systems require a combination of high and low technologies--automated subways and conventional sidewalks. Buses and taxicabs may still be the answer in some cities, because more-sophisticated technologies may cause more problems than they solve.

Bell

1978-01-01

264

Transition States for Glucopyranose Interconversion  

Microsoft Academic Search

Glucose is a central molecule in biology and chemistry, and the anomerization reaction has been studied for more than 150 years. Transition-state structure is the last impediment to an in-depth understanding of its solution chemistry. We have measured kinetic isotope effects on the rate constants for approach of R-glucopyranose to its equilibrium with ‚-glucopyranose, and these were converted into unidirectional

Brett E. Lewis; Nankishoresing Choytun; Vern L. Schramm; Andrew J. Bennet

2006-01-01

265

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

266

Modeling Transitivity in Complex Networks  

E-print Network

An important source of high clustering coefficient in real-world networks is transitivity. However, existing approaches for modeling transitivity suffer from at least one of the following problems: i) they produce graphs from a specific class like bipartite graphs, ii) they do not give an analytical argument for the high clustering coefficient of the model, and iii) their clustering coefficient is still significantly lower than real-world networks. In this paper, we propose a new model for complex networks which is based on adding transitivity to scale-free models. We theoretically analyze the model and provide analytical arguments for its different properties. In particular, we calculate a lower bound on the clustering coefficient of the model which is independent of the network size, as seen in real-world networks. More than theoretical analysis, the main properties of the model are evaluated empirically and it is shown that the model can precisely simulate real-world networks from different domains with an...

Chehreghani, Morteza Haghir

2014-01-01

267

Non-equilibrium phase transitions  

SciTech Connect

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken.

Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.

1998-12-31

268

The Transiting Exoplanet Survey Satellite  

E-print Network

The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I<13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler missio...

Ricker, George R; Vanderspek, Roland; Latham, David W; Bakos, Gaspar A; Bean, Jacob L; Berta-Thompson, Zachory K; Brown, Timothy M; Buchhave, Lars; Butler, Nathaniel R; Butler, R Paul; Chaplin, William J; Charbonneau, David; Christensen-Dalsgaard, Jorgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E W; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J; Howard, Andrew W; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John Asher; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M; Lin, Douglas; Lissauer, Jack J; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P R; Morton, Timothy D; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S A; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel

2014-01-01

269

Phase transition dynamics and gravitational waves  

SciTech Connect

During a first-order phase transition, gravitational radiation is generated either by bubble collisions or by turbulence. For phase transitions which took place at the electroweak scale and beyond, the signal is expected to be within the sensitivity range of planned interferometers such as LISA or BBO. We review the generation of gravitational waves in a first-order phase transition and discuss the dependence of the spectrum on the dynamics of the phase transition.

Megevand, Ariel [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales Universidad Nacional de Mar del Plata, Dean Funes 3350 (7600) Mar del Plata (Argentina)

2009-04-20

270

Electrical reliability analysis for transit applications  

Microsoft Academic Search

Maintaining a safe and secure environment for transit patrons has never been more important. People who feel confident in the transit environment will use a transit system. If they don't, they won't. Personal safety and security is especially important in locations where people naturally tend to feel ill-at-ease such as deep, underground stations. Sound Transit is undertaking the construction of

R. Eacker; M. Bardsley

2002-01-01

271

Modeling and Observing Extrasolar Planetary Transits  

Microsoft Academic Search

A computer model, called the Exoplanetary Pixelization Transit Model (EPTM), is developed to calculate exoplanetary transit light curves and determine exoplanet properties from an observed transit light curve. To establish and test the accuracy of the model, an observation of XO-2 was conducted on 2008 Mar 17 where time-series photometry of the transit of XO-2b was collected. Based on the

Brett C. Addison; Samuel T. Durrance; Edward W. Schwieterman

2010-01-01

272

On transit time instability in liquid jets  

NASA Technical Reports Server (NTRS)

A basic transit time instability in flows with disturbances of speed is found. It was shown that the mass distribution is established by and large by the described transit time effects. These transit time effects may also be involved for gas jets.

Grabitz, G.; Meier, G.

1982-01-01

273

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

274

Evidence-Based Practices in Secondary Transition  

ERIC Educational Resources Information Center

A literature review was conducted to identify evidence-based practices in secondary transition using quality indicator checklists for experimental research. Practices were categorized by the Taxonomy for Transition Programming. Overall, 32 secondary transition evidence-based practices were identified. Two practices had a strong level of evidence,…

Test, David W.; Fowler, Catherine H.; Richter, Sharon M.; White, James; Mazzotti, Valerie; Walker, Allison R.; Kohler, Paula; Kortering, Larry

2009-01-01

275

Student Life Veterans Education and Transition Services  

E-print Network

Student Life Veterans Education and Transition Services Veterans Services #12;The UMaine VETS Office (Veterans Education and Transition Services) works in every way possible to make the transition from military to student life simple and hassle-free. Our Mission: The VETS Office connects veteran

Thomas, Andrew

276

Children's Agency during Transition to Formal Schooling  

ERIC Educational Resources Information Center

Children's transition to school is a key issue in early years of education. Research in this field points to the counterintuitive possibility that the transition to school may actually lead to a reduction rather than a facilitation of children's agency. The paper presents findings of a longitudinal comparative ethnography on children's transition

Huf, Christina

2013-01-01

277

Evening Transition Observations in Phoenix, Arizona  

Microsoft Academic Search

Past research has suggested that the evening transition in complex topography typically has several main features, such as (a) continued weak upslope flows persisting 3-5 h after sunset (if the sidewalls of the valley prevent Coriolis-induced turning of winds), thus signifying delayed transition; (b) unsteady local stagnation and vertical mixing within tens of meters above the surface; and (c) transition

A. J. Brazel; H. J. S. Fernando; J. C. R. Hunt; N. Selover; B. C. Hedquist; E. Pardyjak

2005-01-01

278

40 CFR 7.75 - Transition plan.  

Code of Federal Regulations, 2011 CFR

...a) Requirements. The transition plan must set forth the...persons. At a minimum, the transition plan must: (1) Identify...year-by-year timetable if the process will take more than one year...make available a copy of the transition plan to the OCR upon...

2011-07-01

279

Meeting the Needs of Students in Transition  

ERIC Educational Resources Information Center

As our society becomes more mobile, smooth and rewarding student transitions become more important. This article describes a partnership between U. S. Army Child and Youth Services and the Military Child Education Coalition that helps schools ease transitions for thousands of students. The program is based on the principle that transition does not…

Summers, Al; Moehnke, Larry

2006-01-01

280

40 CFR 7.75 - Transition plan.  

Code of Federal Regulations, 2010 CFR

...a) Requirements. The transition plan must set forth the...persons. At a minimum, the transition plan must: (1) Identify...year-by-year timetable if the process will take more than one year...make available a copy of the transition plan to the OCR upon...

2010-07-01

281

Notes on Black Hole Phase Transitions  

Microsoft Academic Search

In these notes we present a summary of existing ideas about phase transitions of black hole spacetimes in semiclassical gravity and offer some thoughts on three possible scenarios or mechanisms by which these transitions could take place. We begin with a review of the thermodynamics of a black hole system and emphasize that the phase transition is driven by the

G. J. Stephens; B. L. Hu

2001-01-01

282

Vulnerable Youth and Transitions to Adulthood  

ERIC Educational Resources Information Center

This chapter focuses on vulnerable youth, the challenges they face during their transitions to adulthood, and the adverse effects of limited support systems on those transitions. The authors offer recommendations on how adult educators can help facilitate smooth transitions into adulthood for vulnerable youth.

Xie, Rongbing; Sen, Bisakha; Foster, E. Michael

2014-01-01

283

Managing Change and Transition, Creating a Future  

ERIC Educational Resources Information Center

Beginning in childhood and on into adulthood, people experience many transitions and changes in their lives. Some people cope with change better than others and make transitions easily; some people may experience a longer transition in order to integrate change. Most people have a fear of change due to uncertainty. Once a person releases that…

Liu, Karen

2008-01-01

284

Phase transitions of superconducting wire network  

E-print Network

Phase transitions of superconducting wire network under field modulation Institute for Solid State;Normal ( = 0) R = 0 Phase transition of superconducting wire network (SWN) 1. Mean field transition o 14 o 12 o 10 o 8 o 6 o 4 o 2 o 0 o Offset:30 mK Pick up one period Compare with calculation (black

Katsumoto, Shingo

285

Transition Path Theory E. Vanden-Eijnden  

E-print Network

Transition Path Theory E. Vanden-Eijnden Courant Institute of Mathematical Sciences, New York University New York, NY 10012 eve2cims.nyu.edu Eric Vanden-Eijnden E. Vanden-Eijnden: Transition Path Theory State Theory (TST) and Transition Path Sampling (TPS). . . . . . . . . . . . . . . . . . . . . . 455 6

Van Den Eijnden, Eric

286

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

287

Work and quantum phase transitions: quantum latency.  

PubMed

We study the physics of quantum phase transitions from the perspective of nonequilibrium thermodynamics. For first-order quantum phase transitions, we find that the average work done per quench in crossing the critical point is discontinuous. This leads us to introduce the quantum latent work in analogy with the classical latent heat of first order classical phase transitions. For second order quantum phase transitions the irreversible work is closely related to the fidelity susceptibility for weak sudden quenches of the system Hamiltonian. We demonstrate our ideas with numerical simulations of first, second, and infinite order phase transitions in various spin chain models. PMID:25019721

Mascarenhas, E; Bragança, H; Dorner, R; França Santos, M; Vedral, V; Modi, K; Goold, J

2014-06-01

288

High-frequency transmission line transitions  

NASA Astrophysics Data System (ADS)

This paper demonstrates the use of modern electromagnetic simulation software to design and develop a selection of three novel transmission line transitions, for operation at mm-wavelengths, and an improvement in the performance of existing transitions. Specifically, our three case studies analyse (i) a microstrip-to-stripline transition, (ii) an inverted microstrip transition, and (iii) a mtripline-to-finline transition. The important concepts are described and the tools available are explained. A number of novel and effective designs are presented as examples.

Hall, Leonard T.; Hansen, Hedley J.; Abbott, Derek

2005-02-01

289

Metal to semiconductor transition in metallic transition metal dichalcogenides  

SciTech Connect

We report on tuning the electronic and magnetic properties of metallic transition metal dichalcogenides (mTMDCs) by 2D to 1D size confinement. The stability of the mTMDC monolayers and nanoribbons is demonstrated by the larger binding energy compared to the experimentally available semiconducting TMDCs. The 2D MX{sub 2} (M?=?Nb, Ta; X?=?S, Se) monolayers are non-ferromagnetic metals and mechanically softer compared to their semiconducting TMDCs counterparts. Interestingly, mTMDCs undergo metal-to-semiconductor transition when the ribbon width approaches to ?13?Å and ?7?Å for zigzag and armchair edge terminations, respectively; then these ribbons convert back to metal when the ribbon widths further decrease. Zigzag terminated nanoribbons are ferromagnetic semiconductors, and their magnetic properties can also be tuned by hydrogen edge passivation, whereas the armchair nanoribbons are non-ferromagnetic semiconductors. Our results display that the mTMDCs offer a broad range of physical properties spanning from metallic to semiconducting and non-ferromagnetic to ferromagnetic that is ideal for applications where stable narrow bandgap semiconductors with different magnetic properties are desired.

Li, Yan; Kang, Jun; Li, Jingbo, E-mail: jbli@semi.ac.cn [State Key Laboratory of Superlattice and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Tongay, Sefaattin; Wu, Junqiao [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Yue, Qu [College of Science, National University of Defense Technology, Changsha 410073 (China)

2013-11-07

290

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

291

Constraining Orbital Parameters Through Planetary Transit Monitoring  

E-print Network

The orbital parameters of extra-solar planets have a significant impact on the probability that the planet will transit the host star. This was recently demonstrated by the transit detection of HD 17156b whose favourable eccentricity and argument of periastron dramatically increased its transit likelihood. We present a study which provides a quantitative analysis of how these two orbital parameters affect the geometric transit probability as a function of period. Further, we apply these results to known radial velocity planets and show that there are unexpectedly high transit probabilities for planets at relatively long periods. For a photometric monitoring campaign which aims to determine if the planet indeed transits, we calculate the expected transiting planet yield and the significance of a potential null result, as well as the subsequent constraints that may be applied to orbital parameters.

Stephen R. Kane; Kaspar von Braun

2008-08-13

292

Glass Transition in Confined Geometry  

E-print Network

Extending mode-coupling theory, we elaborate a microscopic theory for the glass transition of liquids confined between two parallel flat hard walls. The theory contains the standard MCT equations in bulk and in two dimensions as limiting cases and requires as input solely the equilibrium density profile and the structure factors of the fluid in confinement. We evaluate the phase diagram as a function of the distance of the plates for the case of a hard sphere fluid and obtain an oscillatory behavior of the glass transtion line as a result of the structural changes related to layering.

Simon Lang; Vitalie Botan; Martin Oettel; David Hajnal; Thomas Franosch; Rolf Schilling

2010-08-23

293

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

2012-01-19

294

Transition splices and cost comparison  

NASA Technical Reports Server (NTRS)

The development and testing of two designs of transition splices are reported. The design goal was to produce splice terminations that are electrically insulated to withstand the environmental conditions of commercial aircraft and are capable of being repaired and reworked on installed cables with the use of hand tools. In addition, a cost study comparison of FCC vs. RCC is reported. The comparison was made on a basis of 10 aircraft with each vehicle using approximately 100,000 feet of wiring and 2,000 connectors. The results are tabulated for seven different wiring configurations.

Remedios, M. D.

1972-01-01

295

Low floor mass transit vehicle  

DOEpatents

A mass transit vehicle includes a frame structure that provides an efficient and economical approach to providing a low floor bus. The inventive frame includes a stiff roof panel and a stiff floor panel. A plurality of generally vertical pillars extend between the roof and floor panels. A unique bracket arrangement is disclosed for connecting the pillars to the panels. Side panels are secured to the pillars and carry the shear stresses on the frame. A unique seating assembly that can be advantageously incorporated into the vehicle taking advantage of the load distributing features of the inventive frame is also disclosed.

Emmons, J. Bruce (Beverly Hills, MI); Blessing, Leonard J. (Rochester, MI)

2004-02-03

296

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

297

19 CFR 122.102 - Inspection of baggage in transit.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Inspection of baggage in transit. 122.102 Section 122.102 Customs...COMMERCE REGULATIONS Accompanied Baggage in Transit § 122.102 Inspection of baggage in transit. (a) General baggage in transit...

2010-04-01

298

Family transitions in young adulthood.  

PubMed

Using the first (1995) and third (2001-2002) waves of the Add Health survey, we examine women 's family transitions up to age 24. Only a third of all women marry, and a fifth of those marriages dissolve before age 24. Three out of eight women have afirst birth, with a substantial majority of those births outside of marriage: 66% for whites, 96% for blacks, and 72% for Mexican Americans. Cohabitation is the predominant union form; 59% of women cohabit at least once by age 24. Most cohabitations are short lived, with approximately one in five resulting in a marriage. We summarize the family and relationship experience of women up to age 24 in terms offour categories, each accounting for roughly a quarter of all women. Category 1 has the women who remain single nonparents. Category 2 has the early marriers, women whose marriage is not preceded by a first birth. Category 3 has those who become single parents. Category 4 has the women who cohabit at least once, but who do not marry or have a birth by age 24. The strictly ordered transitions of the 1950s are long gone and have been replaced by a variety of paths to adulthood. PMID:18232212

Schoen, Robert; Landale, Nancy S; Daniels, Kimberly

2007-11-01

299

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

300

Chiral transition with magnetic fields  

E-print Network

We study the nature of the chiral transition for an effective theory with spontaneous breaking of symmetry, where charged bosons and fermions are subject to the effects of a constant external magnetic field. The problem is studied in terms of the relative intensity of the magnetic field with respect to the mass and the temperature. When the former is the smallest of the scales, we present a suitable method to obtain magnetic and thermal corrections up to ring order at high temperature. By these means, we solve the problem of the instability in the boson sector for these theories, where the squared masses, taken as functions of the order parameter, can vanish and even become negative. The solution is found by considering the screening properties of the plasma, encoded in the resummation of the ring diagrams at high temperature. We also study the case where the magnetic field is the intermediate of the three scales and explore the nature of the chiral transition as we vary the field strength, the coupling constants and the number of fermions. We show that the critical temperature for the restoration of chiral symmetry monotonically increases from small to intermediate values of the magnetic fields and that this temperature is always above the critical temperature for the case when the magnetic field is absent.

Alejandro Ayala; Luis Alberto Hernandez; Ana Julia Mizher; Juan Cristobal Rojas; Cristian Villavicencio

2014-04-25

301

Buckling transition in long ?-helices  

NASA Astrophysics Data System (ADS)

The treatment of bending and buckling of stiff biopolymer filaments by the popular worm-like chain model does not provide adequate understanding of these processes at the microscopic level. Thus, we have used the atomistic molecular-dynamic simulations and the Amber03 force field to examine the compression buckling of ?-helix (AH) filaments at room temperature. It was found that the buckling instability occurs in AHs at the critical force fc in the range of tens of pN depending on the AH length. The decrease of the force fc with the contour length follows the prediction of the classic thin rod theory. At the force fc the helical filament undergoes the swift and irreversible transition from the smoothly bent structure to the buckled one. A sharp kink in the AH contour arises at the transition, accompanied by the disruption of the hydrogen bonds in its vicinity. The kink defect brings in an effective softening of the AH molecule at buckling. Nonbonded interactions between helical branches drive the rearrangement of a kinked AH into the ultimate buckled structure of a compact helical hairpin described earlier in the literature.

Palen?ár, Peter; Bleha, Tomáš

2014-11-01

302

Dynamic transition in supercritical iron.  

PubMed

Recent advance in understanding the supercritical state posits the existence of a new line above the critical point separating two physically distinct states of matter: rigid liquid and non-rigid gas-like fluid. The location of this line, the Frenkel line, remains unknown for important real systems. Here, we map the Frenkel line on the phase diagram of supercritical iron using molecular dynamics simulations. On the basis of our data, we propose a general recipe to locate the Frenkel line for any system, the recipe that importantly does not involve system-specific detailed calculations and relies on the knowledge of the melting line only. We further discuss the relationship between the Frenkel line and the metal-insulator transition in supercritical liquid metals. Our results enable predicting the state of supercritical iron in several conditions of interest. In particular, we predict that liquid iron in the Jupiter core is in the "rigid liquid" state and is highly conducting. We finally analyse the evolution of iron conductivity in the core of smaller planets such as Earth and Venus as well as exoplanets: as planets cool off, the supercritical core undergoes the transition to the rigid-liquid conducting state at the Frenkel line. PMID:25424664

Fomin, Yu D; Ryzhov, V N; Tsiok, E N; Brazhkin, V V; Trachenko, K

2014-01-01

303

Synfuels and the energy transition  

NASA Astrophysics Data System (ADS)

Various synfuel options and their impact on the electric utility industry are discussed. The energy transition for the U.S.A. is seen as moving from natural fluid fuels to solid fuels and renewable energy resources. The key to this transition is electrification, which can encompass both nuclear and renewable resources, centralized and dispersed technologies. It is shown that the fraction of total energy converted to electricity has risen steadily for the past 30 years, reaching 33% last year. The abundance and cost of production of the various fossil energy resources, including natural gas, heavy oil, oil shale, and coal are considered. EPRI analyses indicate that an integrated-combined-cycle power plant could be competitive with conventional coal plant technology. These plants would use only half the water of current coal-fired plants, would meet tighter sulfur emission standards, and would produce a vitreous ash that is less leachable than the ash from today's coal plants. Solvent-refined coal processes, currently being developed in the U.S.A. are a second approach to converting coal to liquid fuels. It is pointed out, however, that synfuels will complement, not replace, other sources of energy in the continued electrification of the U.S.A.

Balzhiser, R. E.

1981-08-01

304

Enantioselective, transition metal catalyzed cycloisomerizations.  

PubMed

This review illustrates enantioselective transition-metal promoted skeletal rearrangements of polyunsaturated substrates possessing olefin, alkyne or allene functions. These processes are classified according to the number of carbon atoms involved in the cyclization, from (1C+1C) to (2C+2C+2C) or (2C+5C) cyclizations. Thus, for instance, (1C+1C) processes are typified notably by Alder-ene type reactions taking place mainly under palladium and rhodium catalysis, in the presence of chiral phosphorus ligands. Also, rhodium, platinum, and gold promoted insertions of unsaturated carbon-carbon bonds into C-H bonds belong to this class. For each class of reactions or substrate type the best ligand-metal pairs are highlighted. Unfortunately, unlike other transition metal promoted reactions, the mechanisms of chiral induction and stereochemical pathways have not been established so far in any of these reactions. In only a few instances, qualitative heuristic models have been tentatively proposed. Although the available stereochemical information is systematically given here, the paper focuses mainly on synthetic aspects of enantioselective cycloisomerizations. PMID:22674143

Marinetti, Angela; Jullien, Hélène; Voituriez, Arnaud

2012-07-21

305

THE QUASIPERIODIC AUTOMATED TRANSIT SEARCH ALGORITHM  

SciTech Connect

We present a new algorithm for detecting transiting extrasolar planets in time-series photometry. The Quasiperiodic Automated Transit Search (QATS) algorithm relaxes the usual assumption of strictly periodic transits by permitting a variable, but bounded, interval between successive transits. We show that this method is capable of detecting transiting planets with significant transit timing variations without any loss of significance-{sup s}mearing{sup -}as would be incurred with traditional algorithms; however, this is at the cost of a slightly increased stochastic background. The approximate times of transit are standard products of the QATS search. Despite the increased flexibility, we show that QATS has a run-time complexity that is comparable to traditional search codes and is comparably easy to implement. QATS is applicable to data having a nearly uninterrupted, uniform cadence and is therefore well suited to the modern class of space-based transit searches (e.g., Kepler, CoRoT). Applications of QATS include transiting planets in dynamically active multi-planet systems and transiting planets in stellar binary systems.

Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States)

2013-03-10

306

The Quasiperiodic Automated Transit Search Algorithm  

NASA Astrophysics Data System (ADS)

We present a new algorithm for detecting transiting extrasolar planets in time-series photometry. The Quasiperiodic Automated Transit Search (QATS) algorithm relaxes the usual assumption of strictly periodic transits by permitting a variable, but bounded, interval between successive transits. We show that this method is capable of detecting transiting planets with significant transit timing variations without any loss of significance—"smearing"—as would be incurred with traditional algorithms; however, this is at the cost of a slightly increased stochastic background. The approximate times of transit are standard products of the QATS search. Despite the increased flexibility, we show that QATS has a run-time complexity that is comparable to traditional search codes and is comparably easy to implement. QATS is applicable to data having a nearly uninterrupted, uniform cadence and is therefore well suited to the modern class of space-based transit searches (e.g., Kepler, CoRoT). Applications of QATS include transiting planets in dynamically active multi-planet systems and transiting planets in stellar binary systems.

Carter, Joshua A.; Agol, Eric

2013-03-01

307

Morphological Transitions in Block Copolymers.  

NASA Astrophysics Data System (ADS)

This thesis presents detailed studies of previously unobserved thermoreversible phase transitions between different microphase-separated morphologies in block copolymer melts. First, we describe the transformation from the lamellar to the cylindrical morphology in a commercially available poly(styrene) -poly(ethene-co-butene) diblock. Using a self-consistent combination of small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), we identify the considerations which drive each step of the process and describe the intermediate states which form as the transformation progresses. Although we demonstrate the thermoreversibility of the transition, the mechanism by which the reverse transformation occurs remains unknown. Second, we present a thermoreversible transformation from the lamellar morphology to a previously undiscovered bicontinuous cubic phase of Ia3d space group symmetry (entitled the gyroid^*) in a poly(styrene) -poly(isoprene) diblock. We develop the characteristics of this new phase through a self-consistent combination of SAXS, TEM and computer modeling and evaluate aspects of its stability by examining blends of the gyroid ^*-forming material with homopolymers of low molecular weight. We compare these characteristics with those of the ordered bicontinuous double diamond (OBDD) morphology and show that differentiation of the two structures via TEM will be difficult. In addition, we present a re -evaluation of materials previously identified as possessing the OBDD morphology which suggests that most of the literature on bicontinuous phases in block copolymers is probably incorrect. This discovery has significant implications for theories of microphase formation and stability in these materials. Third, we report some preliminary observations on high pressure effects in block copolymers, an area of study which has received surprisingly little examination. SAXS measurements indicate that pressures of up to 600 bar increase the order-disorder transition temperature of poly(styrene) -poly(isoprene) diblocks without causing significant changes in either the segregation product (chiN) or the radius of gyration of the entire molecule. Finally, after discussing the limitations of these measurements, we present an outline for a detailed investigation of pressure effects in polymer materials.

Hajduk, Damian Andrew

308

An Observational Perspective of Transitional Disks  

E-print Network

Transitional disks are objects whose inner disk regions have undergone substantial clearing. The Spitzer Space Telescope produced detailed spectral energy distributions (SEDs) of transitional disks that allowed us to infer their radial dust disk structure in some detail, revealing the diversity of this class of disks. The growing sample of transitional disks also opened up the possibility of demographic studies, which provided unique insights. There now exist (sub)millimeter and infrared images that confirm the presence of large clearings of dust in transitional disks. In addition, protoplanet candidates have been detected within some of these clearings. Transitional disks are thought to be a strong link to planet formation around young stars and are a key area to study if further progress is to be made on understanding the initial stages of planet formation. Here we provide a review and synthesis of transitional disk observations to date with the aim of providing timely direction to the field, which is about...

Espaillat, Catherine; Najita, Joan; Andrews, Sean; Zhu, Zhaohuan; Calvet, Nuria; Kraus, Stefan; Hashimoto, Jun; Kraus, Adam; D'Alessio, Paola

2014-01-01

309

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. PMID:11607270

Speth, J G

1992-01-01

310

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

311

Transit Detection of Radial Velocity Planets  

E-print Network

The orbital parameters of extra-solar planets have a significant impact on the probability that the planet will transit the host star. This was recently demonstrated by the transit detection of HD 17156b whose favourable eccentricity and argument of periastron dramatically increased its transit likelihood. We present a study which provides a quantitative analysis of how these two orbital parameters effect the geometric transit probability as a function of period. Further, we apply these results to known radial velocity planets and show that there are unexpectedly high transit probabilities for planets at relatively long periods. For a photometric monitoring campaign which aims to determine if the planet indeed transits, we calculate the significance of a null result and the subsequent constraints that may be applied to orbital parameters.

Stephen R. Kane; Kaspar von Braun

2008-06-30

312

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

313

The Demographic Transition: Causes and Consequences  

PubMed Central

This paper develops the theoretical foundations and the testable implications of the various mechanisms that have been proposed as possible triggers for the demographic transition. Moreover, it examines the empirical validity of each of the theories and their significance for the understanding of the transition from stagnation to growth. The analysis suggests that the rise in the demand for human capital in the process of development was the main trigger for the decline in fertility and the transition to modern growth PMID:25089157

Galor, Oded

2013-01-01

314

Lipid Thermotropic Transitions in Human Stratum Corneum  

Microsoft Academic Search

The techniques of differential scanning calorimetry (DSC) and thermal perturbation infrared (IR) spectrometry were used to investigate thermal transitions in intact, fractionated, and lipid-extracted human stratum corneum. The DSC results show 3 major and one minor thermal transition in the range of 30-120°C. Of particular interest to this study are 2 transitions seen near 65° and 75°C in intact stratum

Guia M. Golden; Donald B. Guzek; Richard R. Harris; James E. McKie; Russell O. Potts

1986-01-01

315

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

316

Magnetic topological transition in transmission line metamaterials  

NASA Astrophysics Data System (ADS)

We study the magnetic topological transition of the isofrequency curves in the wave vector space from a closed ellipsoid to an open hyperboloid in a metamaterial based on artificial transmission lines. In the radio frequency band we directly measure the emission pattern of a point source placed in the center of the lattice and demonstrate the elliptical wave fronts below the topological transition frequency and hyperbolic wave fronts above the topological transition frequency.

Shchelokova, Alena V.; Filonov, Dmitry S.; Kapitanova, Polina V.; Belov, Pavel A.

2014-09-01

317

Mass Transit Living Lab: Improve the System  

NSDL National Science Digital Library

Students go through the process of identifying possible solutions to the design problems that the existing west corridor transit system faces. Students combine what they have learned from the three previous activities to come up with possible solutions to the design problems faced by the system. This activity requires the use of the Mass Transit Living Labâa web portal to interactive train (transit) traffic data for a major metropolitan city.

Civil And Environmental Engineering Department

318

Bulgarian population in transitional period.  

PubMed

In the transition period from a communist to market-oriented economy, Bulgaria faces several public health challenges. One of them is the decline in population (estimated fall from current 8.25 million to around 6 million in 2045), mainly due to emigration and pronounced fall in fertility. Infant mortality is still relatively high (over 15/1,000 live births), and the incidence of tuberculosis is on the rise. Total mortality shows a steady upward trend from 12.1/1,000 in 1990 to 14.3/1,000 in 1998. Trends in ischemic heart disease are comparable to those in other Central and Eastern European countries, but stroke mortality is notably higher. This calls for detailed epidemiological studies of risk factors, such as salt consumption, as well as preventive programs for detection and control of high blood pressure. The problems of smoking and alcohol abuse should be addressed by a coordinated public health and legal measures. PMID:11885054

Georgieva, Lidia; Powles, John; Genchev, Gencho; Salchev, Petko; Poptodorov, George

2002-04-01

319

Chicago Transit Authority: Public Art  

NSDL National Science Digital Library

The Chicago Transit Authority (CTA) has long had an ambitious public art program. This handy 62-page guidebook provides interested parties and tourists with a complete listing of these works. Not surprisingly, the works are arranged by elevated line and by stop. The guide starts with providing information about works on the Brown Line, which is a great place to begin. It's a real treat to start with Josh Garber's "Hope and Renewal" which is located at the Kimball stop at the end of the Brown Line in the Albany Park community. Also, baseball fans won't want to miss the artworks located close to the train stations at Wrigley Field and US Cellular Field. The guide also includes an artist index and information about the gorgeous works at CTA headquarters in the city's Near West Side neighborhood.

320

Transitional $?$ strength in Cd isotopes  

E-print Network

The level densities and $\\gamma$-ray strength functions of $^{105,106,111,112}$Cd have been extracted from particle-$\\gamma$ coincidence data using the Oslo method. The level densities are in very good agreement with known levels at low excitation energy. The $\\gamma$-ray strength functions display no strong enhancement for low $\\gamma$ energies. However, more low-energy strength is apparent for $^{105,106}$Cd than for $^{111,112}$Cd. For $\\gamma$ energies above $\\approx$ 4 MeV, there is evidence for some extra strength, similar to what has been previously observed for the Sn isotopes. The origin of this extra strength is unclear; it might be due to $E1$ and $M1$ transitions originating from neutron skin oscillations or the spin-flip resonance, respectively.

A. C. Larsen; I. E. Ruud; A. Bürger; S. Goriely; M. Guttormsen; A. Görgen; T. W. Hagen; S. Harissopulos; H. T. Nyhus; T. Renstrøm; A. Schiller; S. Siem; G. M. Tveten; A. V. Voinov; M. Wiedeking

2013-10-26

321

Phase Transitions in Nonlinear Filtering  

E-print Network

It has been established under very general conditions that the ergodic properties of Markov processes are inherited by their conditional distributions given partial information. While the existing theory provides a rather complete picture of classical filtering models, many infinite-dimensional problems are outside its scope. Far from being a technical issue, the infinite-dimensional setting gives rise to surprising phenomena and new questions in filtering theory. The aim of this paper is to discuss some elementary examples, conjectures, and general theory that arise in this setting, and to highlight connections with problems in statistical mechanics and ergodic theory. In particular, we exhibit a simple example of a uniformly ergodic model in which ergodicity of the filter undergoes a phase transition, and we develop some qualitative understanding as to when such phenomena can and cannot occur. We also discuss closely related problems in the setting of conditional Markov random fields.

Patrick Rebeschini; Ramon van Handel

2014-01-24

322

Transition delay using control theory.  

PubMed

This review gives an account of recent research efforts to use feedback control for the delay of laminar-turbulent transition in wall-bounded shear flows. The emphasis is on reducing the growth of small-amplitude disturbances in the boundary layer using numerical simulations and a linear control approach. Starting with the application of classical control theory to two-dimensional perturbations developing in spatially invariant flows, flow control based on control theory has progressed towards more realistic three-dimensional, spatially inhomogeneous flow configurations with localized sensing/actuation. The development of low-dimensional models of the Navier-Stokes equations has played a key role in this progress. Moreover, shortcomings and future challenges, as well as recent experimental advances in this multi-disciplinary field, are discussed. PMID:21382819

Bagheri, S; Henningson, D S

2011-04-13

323

Magnetochromism in Transition Metal Oxides  

NASA Astrophysics Data System (ADS)

We discuss the discovery and mechanism of magnetic field-induced color changes in three different low-dimensional transition metal oxides: Li purple bronze, (CPA)_2CuBr_4, and Pr-substituted La_1.2Sr_1.8Mn_2O_7. In Li purple bronze, the field manipulates the density of states near E_F, altering O p to Mo d excitations. In the copper halide, the applied field rotates the CuBr4 chromophore units, yielding a strong magnetochromic effect. And in (La_0.4Pr_0.6_1.2Sr_1.8Mn_2O_7, the magnetic field acts on the Jahn-Teller-split Mn^3+ eg orbitals, with consequences of a substantial CMR effect, unusual magnetic relaxation behavior, and a change in orbital occupation.

Musfeldt, Janice; Choi, Jongwoo; Haraldsen, Jason; Woodward, Jonathan; Wei, Xing; He, Jian; Mandrus, David; Landee, Chris; Turnbull, Mark; Suryanarayanan, Ramanathanan; Revcolevschi, Alex

2004-03-01

324

PUREX transition project case study  

SciTech Connect

In December 1992, the US Department of Energy (DOE) directed that the Plutonium-Uranium Extraction (PUREX) Plant be shut down and deactivated because it was no longer needed to support the nation`s production of weapons-grade plutonium. The PUREX/UO{sub 2} Deactivation Project will establish a safe and environmentally secure configuration for the facility and preserve that configuration for 10 years. The 10-year span is used to predict future maintenance requirements and represents the estimated time needed to define, authorize, and initiate the follow-on decontamination and decommissioning activities. Accomplishing the deactivation project involves many activities. Removing major hazards, such as excess chemicals, spent fuel, and residual plutonium are major goals of the project. The scope of the PUREX Transition Project is described within.

Jasen, W.G.

1996-04-15

325

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

326

SUCCESSFUL TRANSITION Counseling & Substance Abuse Services  

E-print Network

SUCCESSFUL TRANSITION TO COLLEGE Counseling & Substance Abuse Services Director, Frank Budd, Ph and Substance Abuse Services · Undergraduate Academic Services · Dean of Students · Their Professor during

Kunkle, Tom

327

Observations of Extrasolar Planet Transits: What's next?  

NASA Astrophysics Data System (ADS)

Transits of extrasolar planets are a goldmine for our understanding of the physical nature of planets beyond the Solar System. Measurements of radii from transit observations combined with mass determinations from radial velocity spectroscopy, or transit timing variations, have provided the first indications to the planetary composition and interior structure. It turns out that planets show a much richer diversity than found in our own planetary system, considering e.g. the so-called 'super-Earths', 'mini-Neptunes', and inflated giant planets. Transiting exoplanets also allow for spectroscopic observations of their atmospheres, either during transit or near secondary eclipse. Exoplanets showing transits have therefore been identified as key observables, not only for planet detection, but in particular for investigating further planetary nature. As a result, a new generation of instruments (space- and groundbased) for exoplanet transit observations is already in the construction phase and is planned for the near future. Most of these target specifically stars bright enough for spectroscopic follow-up observations, a èlesson learned' from past transit surveys. A clear goal for future investigations of habitable planets is the detection and characterization of terrestrial planets which potentially could harbor life. This talk will review the status and in particular the future of transit observations, with a focus on rocky planets in the habitable zone of their host stars.

Rauer, H.

2014-03-01

328

Microscopic description of nuclear quantum phase transitions.  

PubMed

The relativistic mean-field framework, extended to include correlations related to restoration of broken symmetries and to fluctuations of the quadrupole deformation, is applied to a study of shape transitions in Nd isotopes. It is demonstrated that the microscopic self-consistent approach, based on global effective interactions, can describe not only general features of transitions between spherical and deformed nuclei, but also the singular properties of excitation spectra and transition rates at the critical point of quantum shape phase transition. PMID:17931001

Niksi?, T; Vretenar, D; Lalazissis, G A; Ring, P

2007-08-31

329

Hydrodynamic instabilities and the transition to turbulence  

NASA Astrophysics Data System (ADS)

Topics in hydrodynamic instability and the transition to turbulence covered include strange attractors and turbulence; hydrodynamic stability and bifurcation, with attention to the Navier-Stokes equations; chaotic behavior and fluid dynamics, with reference to the Lorenz equations and Landau's idea; and the transition to turbulence in Rayleigh-Benard convection. Also considered are instabilities and transition flow between concentric rotating cylinders; shear flow instabilities and transition; instabilities in geophysical fluid dynamics; and instabilities and chaos in nonhydrodynamic systems, such as those of the Rikitake dynamo model for the earth's magnetic field and the Belousov-Zhabotinskii chemical reaction.

Swinney, H. L.; Gollub, J. P.

330

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., P transition. 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

331

Dynamics of stimulated L ? H transitions  

SciTech Connect

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. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Center for Computational Science and e-Systems, Japan Atomic Energy Agency, Chiba 277-8587 (Japan); Diamond, P. H.; Xiao, W. W. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 (United States); Hahn, S.-H. [KSTAR Team, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [KSTAR Team, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Gürcan, Ö. D. [LPP, Ecole Polytechnique, CNRS, 92118 Palaiseau Cedex (France)] [LPP, Ecole Polytechnique, CNRS, 92118 Palaiseau Cedex (France); Tynan, G. R. [Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 (United States)] [Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 (United States)

2013-08-15

332

Kepler Stars with Multiple Transiting Planet Candidates  

NASA Technical Reports Server (NTRS)

NASA's Kepler spacecraft was launched into an Earth-trailing heliocentric orbit in March of 2009. Kepler is designed to conduct a statistical census of planetary system properties using transit photometry. Among the most exciting early results from Kepler are target stars found to have photometric signatures that suggest the presence of more than one transiting planet. Individual transiting planets provide information on the size and orbital period distributions of exoplanets. Multiple transiting planets provide additional information on the spacing and flatness distributions of planetary systems. Results to d ate and plans for future analysis will be presented.

Lissauer, Jack J.

2012-01-01

333

THE TRANSIT LIGHT CURVE PROJECT. X. A CHRISTMAS TRANSIT OF HD 17156b  

E-print Network

Photometry is presented of the 2007 December 25 transit of HD 17156b, which has the longest orbital period and highest orbital eccentricity of all the known transiting exoplanets. New measurements of the stellar radial ...

Winn, Joshua Nathan

334

Dielectric pre-transitional behavior in the vicinity of isotropic–blue phase III transition  

Microsoft Academic Search

Pre-transitional effects have been observed from the study of static dielectric permittivity () and its temperature derivatives () near the isotropic to blue phase-III (I–BPIII) transition in a highly polar T-shaped liquid crystalline material having a stable BPIII phase which persists over a comparatively wide range of temperature (?8°C). The pre-transitional behavior near I–BPIII transition is found to be very

Manoj Marik; M. Rahman; B. K. Chaudhuri; A. Yoshizawa

2011-01-01

335

Dielectric pre-transitional behavior in the vicinity of isotropic–blue phase III transition  

Microsoft Academic Search

Pre-transitional effects have been observed from the study of static dielectric permittivity () and its temperature derivatives () near the isotropic to blue phase-III (I–BPIII) transition in a highly polar T-shaped liquid crystalline material having a stable BPIII phase which persists over a comparatively wide range of temperature (?8°C). The pre-transitional behavior near I–BPIII transition is found to be very

Manoj Marik; M. Rahman; B. K. Chaudhuri; A. Yoshizawa

2012-01-01

336

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

337

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

338

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

339

Interaction Effects on Radiative Transitions in Nuclei  

Microsoft Academic Search

Electromagnetic transition processes in nuclei are considered on the assumption that the influence of an external electromagnetic field on a nucleus can be incorporated into a guage invariant Schroedinger equation for the nucleons (phenomenological theory). From the results of the preceding paper it is concluded that equations for electric multipole transition probabilities have the usual form but that the f-sum

N. Austern; R. G. Sachs

1951-01-01

340

Radio-Transit Telescopes steerable in Azimuth  

Microsoft Academic Search

WHEN considering radio-transit telescopes, one ordinarily speaks in terms of instruments steerable in altitude. However, transit telescopes steered in azimuth have potentialities which should be evaluated. Bracewell1 and Drake2 have made suggestions for azimuth steerability. Both their designs utilize offset foci and the concept of a segmented reflecting surface.

P. D. Usher

1963-01-01

341

Phase transitions in rocks under shock compression  

Microsoft Academic Search

The zero-pressure densities of some rock Hugoniots in their high-pressure phases are determined. Comparison of these densities with experimental results on phase transitions of a number of rock-forming minerals suggests that the predominant transition in Stillwater bronzitite and Bushveld bronzitite is pyroxene --> spinel + stipoverite (stishovite). Pyroxene in Healdsburg diabase and Centreville diabase is likely to transform in the

Wang Chi-Yuen

1967-01-01

342

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

343

Transition electromagnetic fields in particle physics  

Microsoft Academic Search

We present a computation of one-loop effective potentials for elementary systems placed in a strong magnetic or a laser-produced electromagnetic environment. This permits a determination in principle of a hierarchy of transition field strengths, for which the systems concerned may (for appropriate values of the parameters in the theory) make transitions from a spontaneously broken asymmetric phase to one of

Abdus Salam; J. Strathdee

1975-01-01

344

ImprovingTransitions of Care Handoffs from  

E-print Network

ImprovingTransitions of Care Handoffs from Cardiac OR to ICU The Cardiac Surgery Translational on a variety of levels. The team developed an Assessment of Care Transitions checklist to be tested to reduce the mortality, morbidity, and costs of care related to cardiac surgery patients through

Connor, Ed

345

FRACTIONAL LAPLACIAN PHASE TRANSITIONS AND BOUNDARY REACTIONS  

E-print Network

FRACTIONAL LAPLACIAN PHASE TRANSITIONS AND BOUNDARY REACTIONS: A GEOMETRIC INEQUALITY-called fractional Laplacian. The study of this nonlocal equation is made via a careful analysis of the following: Boundary reactions, Allen-Cahn phase transitions, frac- tional operators, Poincar´e-type inequality. 2000

346

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

347

Magnetic field generation from nonequilibrium phase transitions  

Microsoft Academic Search

We study the generation of magnetic fields during the stage of particle production resulting from spinodal instabilities during phase transitions out of equilibrium. The main premise is that long-wavelength instabilities that drive the phase transition lead to strong nonequilibrium charge and current fluctuations which generate electromagnetic fields. We present a formulation based on the nonequilibrium Schwinger-Dyson equations that leads to

D. Boyanovsky; H. J. de Vega; M. Simionato

2003-01-01

348

Hyperconifold Transitions, Mirror Symmetry, and String Theory  

E-print Network

Multiply-connected Calabi-Yau threefolds are of particular interest for both string theorists and mathematicians. Recently it was pointed out that one of the generic degenerations of these spaces (occurring at codimension one in moduli space) is an isolated singularity which is a finite cyclic quotient of the conifold; these were called hyperconifolds. It was also shown that if the order of the quotient group is even, such singular varieties have projective crepant resolutions, which are therefore smooth Calabi-Yau manifolds. The resulting topological transitions were called hyperconifold transitions, and change the fundamental group as well as the Hodge numbers. Here Batyrev's construction of Calabi-Yau hypersurfaces in toric fourfolds is used to demonstrate that certain compact examples containing the remaining hyperconifolds - the Z_3 and Z_5 cases - also have Calabi-Yau resolutions. The mirrors of the resulting transitions are studied and it is found, surprisingly, that they are ordinary conifold transitions. These are the first examples of conifold transitions with mirrors which are more exotic extremal transitions. The new hyperconifold transitions are also used to construct a small number of new Calabi-Yau manifolds, with small Hodge numbers and fundamental group Z_3 or Z_5. Finally, it is demonstrated that a hyperconifold is a physically sensible background in Type IIB string theory. In analogy to the conifold case, non-perturbative dynamics smooth the physical moduli space, such that hyperconifold transitions correspond to non-singular processes in the full theory.

Rhys Davies

2011-02-07

349

Quantum Phase Transitions in a Finite System  

E-print Network

A general procedure for studying finite-N effects in quantum phase transitions of finite systems is presented and applied to the critical-point dynamics of nuclei undergoing a shape-phase transition of second-order (continuous), and of first-order with an arbitrary barrier.

A. Leviatan

2006-12-05

350

Family Perceptions of Transitions in Early Intervention  

ERIC Educational Resources Information Center

This article explores three broad themes about transitions that have emerged in a naturalistic study of experiences of families with young children with disabilities. Generalizations regarding early transitions include families going through a birth crisis have difficulty understanding all the information they are provided. Not only is their role…

Lovett, David L.; Haring, Kathryn A.

2003-01-01

351

A Conceptual Model for Leadership Transition  

ERIC Educational Resources Information Center

The purpose of this study was to develop a model of leadership transition based on an integrative review of literature. The article establishes a compelling case for focusing on leadership transitions as an area for study and leadership development practitioner intervention. The proposed model in this study identifies important success factors…

Manderscheid, Steven V.; Ardichvili, Alexandre

2008-01-01

352

Transition to turbulence and flow control  

E-print Network

Transition to turbulence and flow control Jerome Hoepffner Fukagata lab 1 #12;Instability and pipe are stable for all Reynolds. + For boundary layers, transition to turbulence is observed before critical Reynolds number ... what is the mechanism? 2 #12;Transient growth in the boundary layer Some

Hoepffner, Jérôme

353

Total Factor Productivity and the Mongolian Transition  

Microsoft Academic Search

Total Factor Productivity (TFP)is often used on the macro-economic level as an indicator of changes in efficiency of a country. In many transition economies TFP is seen to have been negative the last decade of the plan economy and starts increasing and become positive after a (quite a) few years of transition. Many authors conclude that this is a gain

Antonio G. Chessa; Marije C. Schouwstra

2005-01-01

354

Transitions in the Web of Heterotic Vacua  

Microsoft Academic Search

We analyze transitions between heterotic vacua with distinct gauge bundles using two complementary methods - the effective four-dimensional field theory and the corresponding geometry. From the viewpoint of effective field theory, such transitions occur between flat directions of the potential energy associated with heterotic stability walls. Geometrically, this branch structure corresponds to smooth deformations of the gauge bundle coupled to

Lara B. Anderson; James Gray; Burt Ovrut

2010-01-01

355

Spectral Entropy Behavior in Transitional Flows  

Microsoft Academic Search

This dissertation presents a study of the correlation between self-organization and spectral entropy in transition flows. The spectral entropy algorithm is applied to three theoretical dynamical systems, to experimental data taken from an internal cavity shear layer and to a novel model describing transition in a wall boundary layer. The results show a decrease in spectral entropy when self-organization occurs.

John Christian Crepeau

1991-01-01

356

Remarks on the Electroweak Phase Transition  

E-print Network

In the standard scenario, the electroweak phase transition is a first order phase transition which completes by the nucleation of critical bubbles. Recently, there has been speculation that the standard picture of the electroweak phase transition is incorrect. Instead, it has been proposed that throughout the phase transition appreciable amounts of both broken and unbroken phases of $SU(2)$ coexist in equilibrium. I argue that this can not be the case. General principles insure that the universe will remain in a homogenous state of unbroken $SU(2)$ until the onset of critical bubble production. In addition, an analytic treatment of the one Higgs doublet, electroweak phase transition in the standard model and minimal extensions is reviewed. Results from the thin wall approximation are compared to results obtained using the Lindes' action. Perhaps the most important quantitative result we can get from an analysis of the phase transition is determination of $\\vevphi$ when the phase transition completes. For Higgs boson masses above the current experimental limit, the thin wall approximation determines the value of $\\vevphi$ at the end of the phase transition to an accuracy of better than three percent.

Greg W. Anderson

1992-06-23

357

Earth and Venus transmission spectra during transit  

E-print Network

Earth and Venus transmission spectra during transit 3rd Europlanet workshop ­ 4th PHC/Sakura meeting: Venus as a transiting exoplanet March 5 ­ 7 2012, Paris, France A. García Muñoz (Formerly at) Instituto de Astrofísica de Canarias, La Laguna, Spain Frank P. Mills (Venus work) The Australian National

Widemann, Thomas

358

Transition Strategies for Persons with Learning Disabilities.  

ERIC Educational Resources Information Center

This collection of 10 papers focuses on the transition of students with learning disabilities from secondary education to employment, postsecondary education, independent living, and full social integration. The text concentrates on systemic transition problems that prevent successful communication, coordination, goal setting, and appropriate…

Michaels, Craig A., Ed.

359

Environmentally Friendly Renormalization Group and Phase Transitions  

E-print Network

We discuss an environmentally friendly renormalization group approach to analyze phase transitions. We intend to apply this method to the Electroweak Phase Transition. This work is in progress. We present some previously obtained results concerning a scalar theory, where the main features of this algorithm are introduced.

F. Astorga

2002-02-01

360

Environmentally Friendly Renormalization Group and Phase Transitions  

E-print Network

We discuss an environmentally friendly renormalization group approach to analyze phase transitions. We intend to apply this method to the Electroweak Phase Transition. This work is in progress. We present some previously obtained results concerning a scalar theory, where the main features of this algorithm are introduced.

Astorga, F

2002-01-01

361

High Frequency Microphone Measurements for Transition Detection  

E-print Network

! High Frequency Microphone Measurements for Transition Detection on Airfoils Mads Døssing Risø Døssing Risø­R­1645(EN) Title: High Frequency Microphone Measurements for Transition Detection on Airfoils of pressure fluctuations has been obtained using high frequency microphones distributed over the surface

362

Analysis on Cost of Urban Rail Transit  

Microsoft Academic Search

Nowadays, urban rail transit has been the most effective solution to the traffic congestion because of its fast, efficient, safe, energy saving and environmental protecting characteristics. However, the high cost of rail projects and the operation maintenance, together with the social problems brought by the urban rail transit such as noise pollution, traffic accidents and air pollution have become the

Wenxing Li; Shuai Yin

2012-01-01

363

Financial Management for Transit: A Handbook.  

ERIC Educational Resources Information Center

This handbook is primarily intended to serve as a primer for transit system managers who have not had any formal financial education through college classes, professional development programs, or extensive on-the-job programs. The following topics are covered: financial planning techniques for transit (beginning the financial planning process,…

Heaselden, Mark; And Others

364

Understanding Secondary-Tertiary Transition in Mathematics  

ERIC Educational Resources Information Center

In Clark and Lovric ("Suggestion for a theoretical model for secondary-tertiary transition in mathematics", "Math. Educ. Res. J." 20(2) (2008), pp. 25-37) we began developing a model for the secondary-tertiary transition in mathematics, based on the anthropological notion of a rite of passage. We articulated several reasons why we believe that the…

Clark, Megan; Lovric, Miroslav

2009-01-01

365

Transition Strategies to Ensure Active Student Engagement  

ERIC Educational Resources Information Center

Transition into college for students with disabilities has been written about extensively over the past decade, due in part to legislative mandates implemented at the secondary level. With significant increases in the number of these students in the college population, a focus on their transition through college is imperative to improve retention…

Korbel, Donna M.; McGuire, Joan M.; Banerjee, Manju; Saunders, Sue A.

2011-01-01

366

Demographic life transitions: an alternative theoretical paradigm  

Microsoft Academic Search

Event history analyses, while useful, have limited explanatory power in relation to demographic life transitions. This is because demographic behaviour has a future orientation. People marry, cohabit, have children, divorce or migrate primarily because they have expectations or hopes about how these transitions will affect their lives. Individuals weigh up alternatives about their future within their personal and cultural context.

Peter McDonald

1996-01-01

367

Population momentum for gradual demographic transitions  

Microsoft Academic Search

Population momentum is the ratio of a population's ultimate size after a demographic transition to its initial size before the transition. For an instantaneous drop to replacement fertility, Nathan Keyfitz found a simple expression M K for the momentum. However, as Keyfitz pointed out, `no one thinks that any country will drop immediately to stationary reproduction patterns'. We present results

NAN LI; SHRIPAD TULJAPURKAR

1999-01-01

368

College Success: A Transitional Course for Freshmen.  

ERIC Educational Resources Information Center

A special transitional course (College Success) developed for college freshmen at the State University of New York College at Cortland is described in this report. Designed to meet standard problems of transition from high school to college and deal with detected deficits in learning and studying skills, it offers small group experience on issues…

Hopkins, William M.

369

TRANSIT REALITIES IN THE SUBURBAN GTA  

E-print Network

TRANSIT REALITIES IN THE SUBURBAN GTA Data Management Group Joint Program in Transportation University of Toronto November 1998 #12;TRANSIT REALITIES IN THE SUBURBAN GTA Prepared for Data Management in the four Regional Municipalities that make up the suburban GTA, based primarily on the analysis

Toronto, University of

370

Cell Stem Cell Sic Transit Gloria  

E-print Network

, Cambridge CB2 0RE, UK 4Wellcome Trust Centre for Stem Cell Research, Tennis Court Road, Cambridge CB2 1QRCell Stem Cell Review Sic Transit Gloria: Farewell to the Epidermal Transit Amplifying Cell? Philip H. Jones,1,* Benjamin D. Simons,2 and Fiona M. Watt3,4 1MRC Cancer Cell Unit, Hutchison-MRC Research

Simons, Ben

371

Monitoring, Telemetry, and Control for Rapid Transit  

Microsoft Academic Search

The San Francisco Bay Area Rapid Transit District is building a new rapid transit system on which trains will operate automatically. Multipurpose channels and terminals will be used to monitor and control train operation, electrification, and support facilities. Incoming data and events are to be transmitted and processed digitally. System supervisory control signals, whether incoming or outgoing, will be transmitted

J. Asmus; W. Quintin; J. Barkle; J. Williams

1968-01-01

372

Disproportionality in Transition Services: A Descriptive Study  

ERIC Educational Resources Information Center

The purpose of this study was to examine disproportionality in transition services for students with disabilities. The authors predicted that students' transition services and secondary programs would be driven not only by their postschool goals, but also by their gender, ethnicity, disability, and school setting. To test this hypothesis, the…

Baer, Robert M.; Daviso, Alfred, III; Queen, Rachel McMahan; Flexer, Robert W.

2011-01-01

373

Transition in an Era of Reform.  

ERIC Educational Resources Information Center

This article examines the effect of educational reform on transition services for students with learning disabilities (LD). Considered are effects of general education reform, the inclusion movement, teacher education programs, special education reform, and standards-based education (Goals 2000). The need for effective transition planning for…

Bassett, Diane S.; Smith, Tom E. C.

1996-01-01

374

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 debates…

Russell, Rachel; Tyler, Melissa

2005-01-01

375

Mystified by Menopause? A Major Life Transition  

MedlinePLUS

... review our exit disclaimer . Subscribe Mystified by Menopause? A Major Life Transition Menopause—it’s a transition that looms large in the minds of ... of menstrual periods and fertility. It can be a challenging time, ... symptoms, choosing the best treatment can be confusing. Different therapies ...

376

Transition Services: A Planning and Implementation Guide.  

ERIC Educational Resources Information Center

This booklet contains guidelines for implementing a planning process that enhances the transition-related results of New York school districts' individualized education programs (IEP) for students with disabilities. The guide highlights applicable federal and state law and regulations and provides a logical process that addresses transition

New York State Education Dept., Albany. Office for Special Education Services.

377

PHASE TRANSITION BEHAVIOR IN COMBINATORICS AND  

E-print Network

PHASE TRANSITION BEHAVIOR IN COMBINATORICS AND COMPUTATION Thesis submitted in partial fulfillment-Gurion University of the Negev April 2009 Beer-Sheva #12;#12;PHASE TRANSITION BEHAVIOR IN COMBINATORICS Beimel, who put their hearts into my education as a researcher and into the completion of my thesis. I

Beimel, Amos

378

Assess for Success: Handbook on Transition Assessment.  

ERIC Educational Resources Information Center

This handbook offers guidelines for the successful transition of students with disabilities into adult life and is designed to be used by everyone on the Individualized Education Program (IEP) team, including the student and family members. The first chapter provides an overview of the transition assessment process, including purpose and the laws…

Sitlington, Patricia L.; And Others

379

Building bridges: understanding student transition to university  

Microsoft Academic Search

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 learner identity) are analysed to identify underpinning concepts. Primary data are taken

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

2012-01-01

380

Notes on Black Hole Phase Transitions  

Microsoft Academic Search

In these notes we present a summary of existing ideas about phase transitions of black hole spacetimes in semiclassical gravity and offer some thoughts on three possible scenarios by which these transitions could take place. Our first theme is ilustrated by a quantum atomic black hole system, generalizing to finite-temperature a model originally offered by Bekenstein. In this equilibrium atomic

G. J. Stephens; B. L. Hu

2001-01-01

381

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

382

TRANSITIONAL EMPLOYMENT FOR THE CHRONICALLY MENTALLY ILL  

Microsoft Academic Search

This article discusses the use of transitional employment in the vocational and psychosocial rehabilitation of the chronically mentally ill. The development and implementation of a transitional employment program at Towne House Creative Living Center, Oakland, California, is described. The value of adapting the work environment and use of support groups in aiding psychosocial and vocational adjustment are discussed. It is

Jane L. Dulay; Mary Steichen

1983-01-01

383

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

384

Collaborating in the Transition to Tertiary Writing.  

ERIC Educational Resources Information Center

The Monash University (Australia) Transition to Tertiary Writing Project seeks to produce a World Wide Web-based resource for first-year students to facilitate their transition to the kinds of thinking and writing valued at the university. The background research on which this language and academic skills (LAS) project is based centers on three…

Clerehan, Rosemary; Moore, Tim; Vance, Sheila

385

Phase transitions of superconducting wire network  

E-print Network

POS44 Phase transitions of superconducting wire network under field modulation Institute for Solid-13(2006)@KyotoResearchPark #12;Normal ( = 0) R = 0 Phase transition of superconducting wire network (SWN) 1. MeanK Pick up one period Compare with calculation (black dotted line) Result 8 mT = 1 0o = 0 16o = 1

Katsumoto, Shingo

386

Transitions in the Development of Giftedness  

ERIC Educational Resources Information Center

The purpose of this investigation was to assess the factors that lead to success in transitions of giftedness among a middle school student cohort. As part of the Yale University (PACE Center) Transitions in the Development of Giftedness evaluation plan, qualitative data were collected via a semistructured interview protocol. A total of 63…

Bonner, Fred A., II

2005-01-01

387

Quality bottleneck transitions in flexible manufacturing systems  

Microsoft Academic Search

In this paper, we introduce a Markov chain model to evaluate the quality performance in flexible manufacturing systems with batch productions. In such a model, the product quality is a function of the transition probabilities characterizing the changes among good and defective states (where good quality or defective parts are produced during a cycle, respectively). A transition that has the

Junwen Wang; Jingshan Li; Jorge Arinez; Stephan Biller

2010-01-01

388

Transiting Exoplanet Observations at Grinnell College  

NASA Astrophysics Data System (ADS)

Grinnell College, a small liberal arts college in Grinnell, Iowa with 1600 undergraduate students, is home to the Grant O. Gale Observatory. Over the past year, we have successfully detected extrasolar planets using the transit method with our 24-inch Cassegrain reflecting telescope equipped with a CCD camera. With little light pollution and an easily accessible observatory, Grinnell College is an optimal location for transiting exoplanet observations. With the current telescope set-up and CCD camera, we have taken time series data and created image calibration and post-processing programs that detect exoplanet transits at high photometric precision. In the future, we will continue to use these observation and data reduction procedures to conduct transiting exoplanet research. Goals for our research program include performing follow-up observations of transiting exoplanet candidates to confirm their planetary nature, searching for additional exoplanets in known planetary systems using the transit timing detection method, tracking long period transiting planets, and refining properties of exoplanets and their host stars. Ground-based transiting planet science is especially important in the post-Kepler era, and our dedicated mid-sized telescope with plenty of access to dark clear nights provides an ideal resource for a variety of follow up and exoplanet detection efforts.

Sauerhaft, Julia; Slough, P.; Cale, B.; Kempton, E.

2014-01-01

389

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

390

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

391

BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS  

E-print Network

BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS USING BUS TRACKING TECHNOLOGY May 26, 1999 Maged BUS TRACKING TECHNOLOGY ABSTRACT A timed transfer terminal synchronizes the arrival of incoming of Southern California Los Angeles, CA 90089-0193 #12;BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS USING

Dessouky, Maged

392

Relatedness and the fraternal major transitions  

Microsoft Academic Search

Many of the major transitions in evolution involved the coalescence of independent lower-level units into a higher organismal level. This paper examines the role of kinship, focusing on the transitions to multi- cellularity in animals and to coloniality in insects. In both, kin selection based on high relatedness permitted cooperation and a reproductive division of labour. The higher relatedness of

David C. Queller

2000-01-01

393

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

394

Critical behaviour in the QCD Anderson transition  

E-print Network

We study the Anderson-type localisation-delocalisation transition found previously in the QCD Dirac spectrum at high temperature. Using high statistics QCD simulations with $N_f=2+1$ flavours of staggered quarks, we discuss how the change in the spectral statistics depends on the volume, the temperature and the lattice spacing, and we speculate on the possible universality of the transition from Poisson to Wigner-Dyson in the spectral statistics. Moreover, we show that the transition is a genuine phase transition: at the mobility edge, separating localised and delocalised modes, quantities characterising the spectral statistics become non-analytic in the thermodynamic limit. Using finite size scaling we also determine the critical exponent of the correlation length, and we speculate on possible extensions of the universality of Anderson transitions.

Matteo Giordano; Tamas G. Kovacs; Ferenc Pittler

2013-12-06

395

Detection of Terrestrial Planets Using Transit Photometry  

NASA Technical Reports Server (NTRS)

Transit photometry detection of planets offers many advantages: an ability to detect terrestrial size planets, direct determination of the planet's size, applicability to all main-sequence stars, and a differential brightness change of the periodic signature being independent of stellar distance or planetary orbital semi-major axis. Ground and space based photometry have already been successful in detecting transits of the giant planet HD209458b. However, photometry 100 times better is required to detect terrestrial planets. We present results of laboratory measurements of an end-to-end photometric system incorporating all of the important confounding noise features of both the sky and a space based photometer including spacecraft jitter. In addition to demonstrating an instrumental noise of less than 10 ppm (an Earth transit of a solar-like star is 80 ppm), the brightnesses of individual stars were dimmed to simulate Earth-size transit signals. These 'transits' were reliably detected as part of the tests.

Koch, David; Witteborn, Fred; Jenkins, Jon; Dunham, Edward; Boruci, William; DeVincenzi, Donald (Technical Monitor)

2001-01-01

396

Dynamic Transition Theory for Thermohaline Circulation  

E-print Network

The main objective of this and its accompanying articles is to derive a mathematical theory associated with the thermohaline circulations (THC). This article provides a general transition and stability theory for the Boussinesq system, governing the motion and states of the large-scale ocean circulation. First, it is shown that the first transition is either to multiple steady states or to oscillations (periodic solutions), determined by the sign of a nondimensional parameter $K$, depending on the geometry of the physical domain and the thermal and saline Rayleigh numbers. Second, for both the multiple equilibria and periodic solutions transitions, both Type-I (continuous) and Type-II (jump) transitions can occur, and precise criteria are derived in terms of two computable nondimensional parameters $b_1$ and $b_2$. Associated with Type-II transitions are the hysteresis phenomena, and the physical reality is represented by either metastable states or by a local attractor away from the basic solution, showing m...

Ma, Tian

2009-01-01

397

Reaction coordinates and rates from transition paths  

PubMed Central

The molecular mechanism of a reaction in solution is reflected in its transition-state ensemble and transition paths. We use a Bayesian formula relating the equilibrium and transition-path ensembles to identify transition states, rank reaction coordinates, and estimate rate coefficients. We also introduce a variational procedure to optimize reaction coordinates. The theory is illustrated with applications to protein folding and the dipole reorientation of an ordered water chain inside a carbon nanotube. To describe the folding of a simple model of a three-helix bundle protein, we variationally optimize the weights of a projection onto the matrix of native and nonnative amino acid contacts. The resulting one-dimensional reaction coordinate captures the folding transition state, with formation and packing of helix 2 and 3 constituting the bottleneck for folding. PMID:15814618

Best, Robert B.; Hummer, Gerhard

2005-01-01

398

Diagonal-transition quantum cascade detector  

NASA Astrophysics Data System (ADS)

We demonstrate the concept of diagonal transitions for quantum cascade detectors (QCD). Different to standard, vertical QCDs, here the active transition takes place between two energy levels in adjacent wells. Such a scheme has versatile advantages. Diagonal transitions generally yield a higher extraction efficiency and a higher resistance than vertical transitions. This leads to an improved overall performance, although the absorption strength of the active transition is smaller. Since the extraction is not based on resonant tunneling, the design is more robust, with respect to deviations from the nominal structure. In a first approach, a peak responsivity of 16.9 mA/W could be achieved, which is an improvement to the highest shown responsivity of a QCD for a wavelength of 8 ?m at room-temperature by almost an order of magnitude.

Reininger, Peter; Schwarz, Benedikt; Detz, Hermann; MacFarland, Don; Zederbauer, Tobias; Andrews, Aaron Maxwell; Schrenk, Werner; Baumgartner, Oskar; Kosina, Hans; Strasser, Gottfried

2014-09-01

399

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

400

Atomic inner-shell transitions  

NASA Technical Reports Server (NTRS)

Atomic inner-shell processes have quite different characteristics, in several important aspects, from processes in the optical regime. Energies are large, e.g., the 1s binding energy reaches 100 keV at Z = 87; relativistic and quantum-electrodynamic effects therefore are strong. Radiationless transitions vastly dominate over photon emission in most cases. Isolated inner-shell vacancies have pronounced single-particle character, with correlations generally contributing only approximately 1 eV to the 1s and 2p binding energies; the structure of such systems is thus well tractable by independent-particle self-consistent-field atomic models. For systems containing multiple deep inner-shell vacancies, or for highly stripped ions, the importance of relativistic intermediate coupling and configuration interaction becomes pronounced. Cancellation of the Coulomb interaction can lead to strong manifestations of the Breit interaction in such phenomena as multiplet splitting and hypersatellite X-ray shifts. Unique opportunities arise for the test of theory.

Crasemann, B.; Chen, M. H.; Mark, H.

1984-01-01

401

Lunar transit telescope lander design  

NASA Technical Reports Server (NTRS)

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.

1992-01-01

402

Lunar transit telescope lander design  

NASA Technical Reports Server (NTRS)

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.

1991-01-01

403

State Transitions in Semiarid Landscapes  

NASA Astrophysics Data System (ADS)

The U.S. Department of Agriculture has developed a large number of state-and-transition models (STM) to predict and interpret changes in vegetation communities in drylands of the southwestern U.S. These are represented as box-and-arrow models indicating potential changes in response to various combinations of management practices and environmental forcings. Analysis of the 320 STMs developed for areas within the state of Texas reveals two important aspects of environmental change in semiarid environments. First, the STMs are highly local—they are specific to very particular combinations of landform, soil, and climate. This is consistent with the perfect landscape concept in geomorphology, which emphasizes the irreducible importance of geographically and historically contingent local factors in addition to universal laws or principles in determining the state or condition of landscapes. Second, analysis of the STMs using algebraic graph theory shows that a majority of them have structures that tend to amplify effects of change and disturbances. In many cases the STMs represent a form of self-organization characterized by the potential of divergent behavior rather than convergence toward a dominant pattern or outcome. These results indicate that geomorphic, hydrologic, and ecological responses to climate and land use change are likely to be highly variable and idiosyncratic, both within and between semiarid landscapes of Texas.

Phillips, J. D.

2012-04-01

404

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.

405

Phase transition thermodynamics of bisphenols.  

PubMed

Herein we have studied, presented, and analyzed the phase equilibria thermodynamics of a bisphenols (BP-A, BP-E, BP-F, BP-AP, and BP-S) series. In particular, the heat capacities, melting temperatures, and vapor pressures at different temperatures as well as the standard enthalpies, entropies, and Gibbs energies of phase transition (fusion and sublimation) were experimentally determined. Also, we have presented the phase diagrams of each bisphenol derivative and investigated the key parameters related to the thermodynamic stability of the condensed phases. When all the bisphenol derivatives are compared at the same conditions, solids BP-AP and BP-S present lower volatilities (higher Gibbs energy of sublimation) and high melting temperatures due to the higher stability of their solid phases. Solids BP-A and BP-F present similar stabilities, whereas BP-E is more volatile. The introduction of -CH3 groups in BP-F (giving BP-E and BP-A) leads an entropic differentiation in the solid phase, whereas in the isotropic liquids the enthalpic and entropic differentiations are negligible. PMID:25244127

Costa, José C S; Dávalos, Juan Z; Santos, Luís M N B F

2014-10-16

406

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

407

Chiral phase transition in lattice QCD as a metal-insulator transition  

E-print Network

We investigate the lattice QCD Dirac operator with staggered fermions at temperatures around the chiral phase transition. We present evidence of a metal-insulator transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. This strongly suggests the phenomenon of Anderson localization drives the QCD vacuum to the chirally symmetric phase in a way similar to a metal-insulator transition in a disordered conductor. We also discuss how Anderson localization affects the usual phenomenological treatment of phase transitions a la Ginzburg-Landau.

Antonio M. Garcia-Garcia; James C. Osborn

2006-11-17

408

Listening to the Voices of Deaf Students: Essential Transition Issues.  

ERIC Educational Resources Information Center

A study of 69 students with deafness found the following factors facilitated transition from education to adult life and employment: student participation in Individualized Education Program meetings; family involvement in the transition process; transition planning in middle school; and cultural sensitivity in transition planning. Transition

Garay, Suzette V.

2003-01-01

409

Evolutionary transitions in parental care and live bearing in vertebrates  

Microsoft Academic Search

We provide the é rst review of phylogenetic transitions in parental care and live bearing for a wide variety of vertebrates. This includes new analyses of both numbers of transitions and transition probabilities. These reveal numerous transitions by shorebirds and anurans toward uniparental care by either sex. Whereas most or all of the shorebird transitions were from biparental care, nearly

John D. Reynolds; Nicholas B. Goodwin; Robert P. Freckleton

2002-01-01

410

Microgravity Two-Phase Flow Transition  

NASA Technical Reports Server (NTRS)

Two-phase flows under microgravity condition find a large number of important applications in fluid handling and storage, and spacecraft thermal management. Specifically, under microgravity condition heat transfer between heat exchanger surfaces and fluids depend critically on the distribution and interaction between different fluid phases which are often qualitatively different from the gravity-based systems. Heat transfer and flow analysis in two-phase flows under these conditions require a clear understanding of the flow pattern transition and development of appropriate dimensionless scales for its modeling and prediction. The physics of this flow is however very complex and remains poorly understood. This has led to various inadequacies in flow and heat transfer modeling and has made prediction of flow transition difficult in engineering design of efficient thermal and flow systems. In the present study the available published data for flow transition under microgravity condition are considered for mapping. The transition from slug to annular flow and from bubbly to slug flow are mapped using dimensionless variable combination developed in a previous study by the authors. The result indicate that the new maps describe the flow transitions reasonably well over the range of the data available. The transition maps are examined and the results are discussed in relation to the presumed balance of forces and flow dynamics. It is suggested that further evaluation of the proposed flow and transition mapping will require a wider range of microgravity data expected to be made available in future studies.

Parang, M.; Chao, D.

1999-01-01

411

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

412

Transition to turbulence in laminar hypersonic flow  

NASA Technical Reports Server (NTRS)

Progress in a recently started project aimed at the prediction of transition to turbulence in hypersonic flow is briefly discussed. The prediction of transition to turbulence is a very important issue in the design of space vessels. Two space vehicles currently under investigation, namely the aeroassisted transfer vehicle (AOTV) and the trans-atmospheric vehicle (TAV), suffer from strong aerodynamic heating. This heating is strongly influenced by the boundary layer structure. These aerospace vehicles fly in the upper atmospheric layer at a Mach number between 10 and 30 at very low atmospheric pressures. At very high altitudes the flow is laminar, but when the space vessel returns to a lower orbit, the flow becomes turbulent and the heating is dramatically increased. The prediction of this transition process is commonly done by means of experiments. The experimental facilities available nowadays cannot model the hypersonic flow field accurately enough by limitations in Mach and Reynolds number. These facilities also have a large free stream disturbance level which makes it very difficult to investigate transition accurately. An alternative approach is to study transition by theoretical means. Up to now numerical studies of hypersonic flow only discussed steady laminar or turbulent flow. This theoretical approach is extended to the study of transition in hypersonic flow by means of direct numerical simulations and additional theoretical investigations to explain the mechanisms leading to transition. A brief outline of how this research is to be performed is given.

Vandervegt, Jaap

1989-01-01

413

Simplified lattice model for polypeptide fibrillar transitions  

NASA Astrophysics Data System (ADS)

Polypeptide fibrillar transitions are studied using a simplified lattice model, modified from the three-state Potts model, where uniform residues as spins, placed on a cubic lattice, can interact with neighbors to form coil, helical, sheet, or fibrillar structure. Using the transfer matrix method and numerical calculations, we analyzed the partition function and construct phase diagrams. The model manifests phase transitions among coil, helix, sheet, and fibril through parameterizing bond coupling energy ?h,?s,?f, structural entropies sh,ss,sf of helical, sheet, and fibrillar states, and number density ?. The phase diagrams show the transition sequence is basically governed by ?h, ?s, and ?f, while the transition temperature is determined by the competition among ?h, ?s, and ?f, as well as sh, ss, sf, and ?. Furthermore, the fibrillation is accompanied with an abrupt phase transition from coil, helix, or sheet to fibril even for short polypeptide length, resembling the feature of nucleation-growth process. The finite-size effect in specific heat at transitions for the nonfibrillation case can be described by the scaling form of lattice model. With rich phase-transition properties, our model provides a useful reference for protein aggregation experiments and modeling.

Xiao, Xuhui; Wu, Ming-Chya

2014-10-01

414

Overview of escalator applications in rail transit  

NASA Technical Reports Server (NTRS)

The difference in operating environment and in construction between escalators in transit and nontransit use, the impact of recent escalator innovations, and areas which could benefit from urban mass transportation administration sponsored research and development are determined. Several factors causing a more severe transit escalator operating environment are identified. There are no significant design differences between transit and nontransit escalators. Recent innovations that have affected performance and cost include outdoor escalators, extra flat steps at both landings, and modular escalators. Data were collected by interviews at transit agencies. Long term, unscheduled, escalator maintenance records were available for analysis from one property. A description of escalator operating principles is provided. Transit represents less than 5% of the U.S. escalator market. Transit agencies have limited leverage on escalator industry practices. A substantial impact on transit escalator cost and performance can be achieved by research identifying when and how to apply and specify several of the more recent innovations. Purchase of escalators under long term (25 year) maintenance contracts is one method that has been used to promote escalators manufactured for minimum life cycle cost.

Deshpande, G.; Rubenstein, L.

1980-01-01

415

Game Theory and Topological Phase Transition  

E-print Network

Phase transition is a war game. It widely exists in different kinds of complex system beyond physics. Where there is revolution, there is phase transition. The renormalization group transformation, which was proved to be a powerful tool to study the critical phenomena, is actually a game process. The phase boundary between the old phase and new phase is the outcome of many rounds of negotiation between the old force and new force. The order of phase transition is determined by the cutoff of renormalization group transformation. This definition unified Ehrenfest's definition of phase transition in thermodynamic physics. If the strategy manifold has nontrivial topology, the topological relation would put a constrain on the surviving strategies, the transition occurred under this constrain may be called a topological one. If the strategy manifold is open and noncompact, phase transition is simply a game process, there is no table for topology. An universal phase coexistence equation is found, it sits at the Nash equilibrium point. Inspired by the fractal space structure demonstrated by renormalization group theory, a conjecture is proposed that the universal scaling law of a general phase transition in a complex system comes from the coexistence equation around Nash equilibrium point. Game theory also provide us new understanding to pairing mechanism and entanglement in many body physics.

Tieyan Si

2006-01-02

416

An Institutional Approach to Understanding Energy Transitions  

NASA Astrophysics Data System (ADS)

Energy is a central concern of sustainability because how we produce and consume energy affects society, economy, and the environment. Sustainability scientists are interested in energy transitions away from fossil fuels because they are nonrenewable, increasingly expensive, have adverse health effects, and may be the main driver of climate change. They see an opportunity for developing countries to avoid the negative consequences fossil-fuel-based energy systems, and also to increase resilience, by leap-frogging-over the centralized energy grid systems that dominate the developed world. Energy transitions pose both challenges and opportunities. Obstacles to transitions include 1) an existing, centralized, complex energy-grid system, whose function is invisible to most users, 2) coordination and collective-action problems that are path dependent, and 3) difficulty in scaling up RE technologies. Because energy transitions rely on technological and social innovations, I am interested in how institutional factors can be leveraged to surmount these obstacles. The overarching question that underlies my research is: What constellation of institutional, biophysical, and social factors are essential for an energy transition? My objective is to derive a set of "design principles," that I term institutional drivers, for energy transitions analogous to Ostrom's institutional design principles. My dissertation research will analyze energy transitions using two approaches: applying the Institutional Analysis and Development Framework and a comparative case study analysis comprised of both primary and secondary sources. This dissertation includes: 1) an analysis of the world's energy portfolio; 2) a case study analysis of five countries; 3) a description of the institutional factors likely to promote a transition to renewable-energy use; and 4) an in-depth case study of Thailand's progress in replacing nonrenewable energy sources with renewable energy sources. My research will contribute to our understanding of how energy transitions at different scales can be accomplished in developing countries and what it takes for innovation to spread in a society.

Koster, Auriane Magdalena

417

Student-Directed Transition Planning: Increasing Student Knowledge and Self-Efficacy in the Transition Planning Process  

ERIC Educational Resources Information Center

This study examined the effectiveness of a new school to adult life transition planning lesson package titled "Student-Directed Transition Planning". The "Student-Directed Transition Planning" lessons teach transition terms and concepts to provide a means to increase self-determination skills and student participation in transition IEP…

Woods, Lee L.; Sylvester, Lorraine; Martin, James E.

2010-01-01

418

Laser transit anemometer experiences in supersonic flow  

NASA Technical Reports Server (NTRS)

The purpose of this paper is to present examples of velocity measurements obtained in supersonic flow fields with the laser transit anemometer system. Velocity measurements of a supersonic jet exhausting in a transonic flow field, a cone boundary survey in a Mach 4 flow field, and a determination of the periodic disturbance frequencies of a sonic nozzle flow field are presented. Each of the above three cases also serves to illustrate different modes of laser transit anemometer operation. A brief description of the laser transit anemometer system is also presented.

Hunter, William W., Jr.; Humphreys, William M., Jr.

1988-01-01

419

Calculation of radiative transition probabilities and lifetimes  

NASA Technical Reports Server (NTRS)

Procedures for calculating bound-bound and bound-continuum (free) radiative transition probabilities and radiative lifetimes are summarized. Calculations include rotational dependence and R-dependent electronic transition moments (no Franck-Condon or R-centroid approximation). Detailed comparisons of theoretical results with experimental measurements are made for bound-bound transitions in the A-X systems of LiH and Na2. New bound-free results are presented for LiH. New bound-free results and comparisons with very recent fluorescence experiments are presented for Na2.

Zemke, W. T.; Verma, K. K.; Stwalley, W. C.

1982-01-01

420

Transition to Bursting via Deterministic Chaos  

NASA Astrophysics Data System (ADS)

We study statistical properties of the irregular bursting arising in a class of neuronal models close to the transition from spiking to bursting. Prior to the transition to bursting, the systems in this class develop chaotic attractors, which generate irregular spiking. The chaotic spiking gives rise to irregular bursting. The duration of bursts near the transition can be very long. We describe the statistics of the number of spikes and the interspike interval distributions within one burst as functions of the distance from criticality.

Medvedev, Georgi S.

2006-07-01

421

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. PMID:21867509

2011-01-01

422

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

423

Observational Window Functions in Planet Transit Searches  

E-print Network

Window functions describe, as a function of orbital period, the probability that an existing planetary transit is detectable in one's data for a given observing strategy. We show the dependence of this probability upon several strategy and astrophysical parameters, such as length of observing run, observing cadence, length of night, and transit duration. The ability to detect a transit is directly related to the intrinsic noise of the observations. In our simulations of the window function, we explicitly address non-correlated (gaussian or white) noise and correlated (red) noise and discuss how these two different noise components affect window functions in different manners.

Kaspar von Braun; David R. Ciardi

2007-11-27

424

Periodic transition on an axial compressor stator: Incidence and clocking effects. Part 2: Transition onset predictions  

SciTech Connect

Transition onset observations from a 1.5-stage axial compressor outlet stator presented in Part 1 of this paper are compared with the predictions of conventional transition correlations applied in a quasi-steady manner. The viscous/inviscid interaction code MISES is used to predict the blade surface pressure distributions, and boundary layer development. The temporal variation in transition onset is then predicted using ensemble-averaged free-stream turbulence data from the compressor measurements. This simple procedure captures most significant features of the complex transition process on the compressor, and is clearly superior to fixed transition models based on long-term average free-stream turbulence levels. Parallel computations for both natural and bypass transition modes indicate that the natural transition mode tends to dominate on the compressor. This is at variance with turbine airfoil experience, where bypass transition is clearly more important. Comparison of prediction and experiment highlights the significance of leading edge potential flow interactions in promoting periodic wake-induced transition. Viscous/inviscid interactions in the neighborhood of transition can also have an important influence on boundary layer stability and separation phenomena.

Solomon, W.J. [General Electric Aircraft Engines, Cincinnati, OH (United States); Walker, G.J.; Hughes, J.D. [Univ. of Tasmania, Hobart (Australia). School of Engineering

1999-07-01

425

48 CFR 52.247-57 - Transportation Transit Privilege Credits.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Transportation Transit Privilege Credits. 52.247-57 ...Clauses 52.247-57 Transportation Transit Privilege Credits. As prescribed...trade, that offerors may have potential transit credits available and the...

2010-10-01

426

19 CFR 123.31 - Merchandise in transit.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Merchandise in transit. 123.31 Section 123.31 Customs...WITH CANADA AND MEXICO Shipments in Transit Through the United States § 123.31 Merchandise in transit. (a) From one contiguous...

2010-04-01

427

7 CFR 51.1268 - Condition after storage or transit.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Condition after storage or transit. 51.1268 Section 51.1268 Agriculture...Fall Pears 1 Condition After Storage Or Transit § 51.1268 Condition after storage or transit. Decay, scald, or other...

2010-01-01

428

45 CFR 150.221 - Transition to State enforcement.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Transition to State enforcement. 150...REQUIREMENTS RELATING TO HEALTH CARE ACCESS CMS ENFORCEMENT...Requirement § 150.221 Transition to State enforcement...officials to ensure that a transition is effected with respect...

2013-10-01

429

45 CFR 150.221 - Transition to State enforcement.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Transition to State enforcement. 150...REQUIREMENTS RELATING TO HEALTH CARE ACCESS CMS ENFORCEMENT...Requirements § 150.221 Transition to State enforcement...officials to ensure that a transition is effected with respect...

2012-10-01

430

Labour Market Status, Transitions and Gender: a European Perspective  

E-print Network

Octobre 2010 Labour Market Status, Transitions and Gender: a European Perspective Choix d travail #12;#12;Labour Market Status, Transitions and Gender: a European Perspective Choix d MARKET STATUS, TRANSITIONS AND GENDER: A EUROPEAN PERSPECTIVE Christine Erhel, Mathilde Guergoat

Paris-Sud XI, Université de

431

78 FR 46905 - Tobacco Transition Program; Final Assessment Procedures  

Federal Register 2010, 2011, 2012, 2013

...assessments for the Tobacco Transition Program (TTP). Through the Tobacco Transition Payment Program (TTPP...to Tax for the Tobacco Transition Assessment Program) for...than June 1, 2015. The process is as follows....

2013-08-02

432

7 CFR 1410.64 - Transition Incentives Program.  

Code of Federal Regulations, 2011 CFR

...PROGRAM § 1410.64 Transition Incentives Program...To be eligible for the Transition Incentives Program...organic certification process under the Organic Foods...participation in the Transition Incentives...

2011-01-01

433

Development and Validation of the Transition Coordinators Survey  

E-print Network

The purpose of this study was to create a valid and reliable instrument for the field of secondary special education and transition by developing and validating the Transition Coordinators Survey (TCS). Transition coordinators are professionals who...

Bjorkman Wade, Diana K.

2014-05-31

434

7 CFR 51.1309 - Condition after storage or transit.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Condition after storage or transit. 51.1309 Section 51.1309...Standards for Winter Pears 1 Condition After Storage Or Transit § 51.1309 Condition after storage or transit. Decay, scald or other...

2010-01-01

435

The Role of Coaching in Working with Clients in Transition.  

ERIC Educational Resources Information Center

Provides a framework for guiding clients through transitions by explaining the nature of transition, outlining styles of dealing with transition, and offering a methodology to determine whether coaching, counseling, or consulting is best for a particular situation. (JOW)

Bench, Marcia

2001-01-01

436

Fertility transition: forecast for demography.  

PubMed

By the end of the 20th century most industrialized nations had undergone the so-called fertility transition, characterized by a reduction in fertility to below replacement level and a delay in age at initiation of child-bearing. An emerging concern is the severe economic and social consequences of this demographic decline. We present an overview of fertility changes in Italy in the second half of the 20th century and a mathematical model that may provide projections for the future of the demographic situation. Starting in 1950 the increment of the number of children born in Italy is initially positive; however, beginning in 1965 the trend suddenly becomes negative, and this negative trend further increased in 1975. A slight improvement is observed in 1980, followed by a stable situation beginning in 1987. Relevant socioeconomic and cultural events in Italy coincide with these variations in the fertility trend. Malnutrition, which had been endemic for centuries in some areas of central and southern Italy, disappeared rather abruptly in early 1960. The improvement in the economic situation was also associated with a decrease in illiteracy and with many sociocultural changes, with the emergence of new demands that decreased propensity for childbearing. The additional deceleration observed in 1975 corresponds to the diffusion of contraceptive procedures. The progression of sociocultural changes has led to a progressive liberation of women from the biological burden of childbearing. Two phenomena seem relevant in this context: women's emerging interest in entering the workforce and the possibility to disconnect sex from childbearing. The social function of feminism has overwhelmed the primary function of survival and diffusion of the species, giving rise to relevant and worrying demographic effects. However, the modern woman has an unconscious memory of her primary biological role, depending on both her genetic structure and cultural heritage, that should bring about a change in the present strong tendency to demographic decline. The basic notion of memory functions is widely recognized in sciences, for example, in the evolutionary theory of Darwin. Here, we introduce into the equations governing population growth a memory mechanism and a perturbation, and we estimate the reactions of the system to perturbations caused by environmental changes and subsequent delayed effects, such as those that appear in the birth rate beginning in 1965 and 1975. The mathematical modeling of the effects of perturbations of the fertility rate in the Italian population, with the introduction of a mathematical memory formalism, suggests that the effect is strongly reduced, with a relaxation time of about 10 years when the fertility rate approaches a stable value. PMID:19317594

Caputo, M; Nicotra, M; Gloria-Bottini, E

2008-08-01

437

A New Approach for Determining Onset of Transition  

NASA Technical Reports Server (NTRS)

The final report consists of three papers which outline and demonstrate the new method for determining transition onset. The procedure developed under this grant requires specification of the instability mechanism, i.e., Tollmien-Schlichting or crossflow, that leads to transition. The attached papers are entitled: 'An Alternative to the e(sup n) Method for Determining Onset of Transition', 'Transition Model for Swept Wing Flows', and 'A Transition Closure Model for Predicting Transition Onset'.

Hassan, H. A.; Warren, E. S.

1997-01-01

438

Transits of Venus and Mercury as muses  

NASA Astrophysics Data System (ADS)

Transits of Venus and Mercury have inspired artistic creation of all kinds. After having been the first to witness a Venusian transit, in 1639, Jeremiah Horrocks expressed his feelings in poetry. Production has subsequently widened to include songs, short stories, novels, novellas, sermons, theatre, film, engravings, paintings, photography, medals, sculpture, stained glass, cartoons, stamps, music, opera, flower arrangements, and food and drink. Transit creations are reviewed, with emphasis on the English- and French-speaking worlds. It is found that transits of Mercury inspire much less creation than those of Venus, despite being much more frequent, and arguably of no less astronomical significance. It is suggested that this is primarily due to the mythological associations of Venus with sex and love, which are more powerful and gripping than Mercury's mythological role as a messenger and protector of traders and thieves. The lesson for those presenting the night sky to the public is that sex sells.

Tobin, William

2013-11-01

439

SUCCESSFUL TRANSITION Counseling & Substance Abuse Services  

E-print Network

SUCCESSFUL TRANSITION TO COLLEGE Counseling & Substance Abuse Services Director, Frank Budd, Ph � Their Residence Assistant or the RHD � Center for Student Learning � Counseling and Substance Abuse Services

Kasman, Alex

440

Hinode Views the 2012 Venus Transit  

NASA Video Gallery

On June 5, 2012, Hinode captured these stunning views of the transit of Venus -- the last instance of this rare phenomenon until 2117. Hinode is a joint JAXA/NASA mission to study the connections o...

441

The Rarest Eclipse: Transit of Venus  

NSDL National Science Digital Library

The transit of Venus across the disk of the sun is a rare astronomical event that has transfixed astronomers for centuries. June 8, 2004 marked the last occurrence of this event. Due to its extreme rarity (occurring only twice a century) this past transit has been heavily documented and researched by scientists across the globe. This site from the Exploratorium contains educational webcasts and RealMedia streaming coverage of the event. The last instance of the transit of Venus in 1882 is also well documented on this site with an interview from Tony Misch of Lick Observatory and a Quicktime animation made with glass plate negatives. The site provides background information about the planet Venus and the importance of its transit across the sun, as well as information on how to view the event. Educators's will find the "Teacher's Guide" especially useful for lesson and activity plans revolving around Venus.

2008-01-30

442

Improved spectroscopic parameters for transiting planet hosts  

E-print Network

We report homogeneous spectroscopic determinations of the effective temperature, metallicity, and projected rotational velocity for the host stars of 56 transiting planets. Our analysis is based primarily on the stellar ...

Winn, Joshua Nathan

443

The near infrared 12 1 electronic transition  

E-print Network

The near infrared 12 A00 2 X2 A0 1 electronic transition of B3 in a neon matrix Anton Batalov, Jan guided by means of electrostatic lenses into the quadrupole mass filter and were separated from neutral

Maier, John Paul

444

Kepler-16: A Transiting Circumbinary Planet  

E-print Network

We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving ...

Winn, Joshua Nathan

445

Continuum ionization transition probabilities of atomic oxygen  

NASA Technical Reports Server (NTRS)

The technique of photoelectron spectroscopy was used to obtain the relative continuum transition probabilities of atomic oxygen at 584 A for transitions from 3P ground state into the 4S, D2, and P2 states of the ion. Transition probability ratios for the D2 and P2 states relative to the S4 state of the ion are 1.57 + or - 0.14 and 0.82 + or - 0.07, respectively. In addition, transitions from excited O2(a 1 Delta g) state into the O2(+)(2 Phi u and 2 Delta g) were observed. The adiabatic ionization potential of O2(+)(2 Delta g) was measured as 18.803 + or - 0.006 eV.

Samson, J. R.; Petrosky, V. E.

1973-01-01

446

39 CFR 3010.29 - Transition rule.  

Code of Federal Regulations, 2013 CFR

... POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.29 Transition rule. If the Postal Service initial exercise of its authority to file a Type 1-A notice...

2013-07-01

447

39 CFR 3010.29 - Transition rule.  

Code of Federal Regulations, 2011 CFR

... POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.29 Transition rule. If the Postal Service initial exercise of its authority to file a Type 1-A notice...

2011-07-01

448

39 CFR 3010.29 - Transition rule.  

Code of Federal Regulations, 2010 CFR

... POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.29 Transition rule. If the Postal Service initial exercise of its authority to file a Type 1-A notice...

2010-07-01

449

Transitional Novels for Readers of Teen Romances.  

ERIC Educational Resources Information Center

Notes the popularity of adolescent romances. Describes objections to romance novels. Discusses six teen novels which can function as transitional novels, connecting adolescents' ability to read and their interest in romance with books that provide a broader reading perspective. (SR)

Kelly, Patricia P.

1991-01-01

450

Seismic imaging of the mantle transition zone  

E-print Network

In this thesis, we developed a generalized Radon transform of SS precursors for large-scale, high-resolution seismo-stratigraphy of the upper mantle transition zone. The generalized Radon transform (GRT) is based on the ...

Cao, Qin, Ph. D. Massachusetts Institute of Technology

2012-01-01

451

Phase transitions in QCD and string theory  

NASA Astrophysics Data System (ADS)

We develop a unified effective field theory approach to the high-temperature phase transitions in QCD and string theory, incorporating winding modes (time-like Polyakov loops, vortices) as well as low-mass states (pseudoscalar mesons and glueballs, matter and dilaton supermultiplets). Anomalous scale invariance and the Z3 structure of the centre of SU(3) decree a first-order phase transition with simultaneous deconfinement and Polyakov loop condensation in QCD, whereas string vortex condensation is a second-order phase transition breaking a Z2 symmetry. We argue that vortex condensation is accompanied by a dilaton phase transition to a strong coupling regime, and comment on the possible role of soliton degrees of freedom in the high-temperature string phase. On leave of absence from the School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota, USA.

Campell, Bruce A.; Ellis, John; Kalara, S.; Nanopoulos, D. V.; Olive, Keith A.

1991-02-01

452

Transitions from Formal Education to the Workplace  

ERIC Educational Resources Information Center

This chapter frames the transition to adulthood in the context of the moving from formal educational settings to the often less-structured learning that occurs in workplace settings. Although schooling may end, learning continues.

Olson, Joann S.

2014-01-01

453

News & Events LMS Transition Project Update  

E-print Network

. This year, we're featuring an engaging presentation about using mobile devices in the classroom as well flipping courses and the first phase of the LMS Transition Project. Plus, catch a "rapid fire" presentation

454

Hybrid transition control approach for plasma actuators  

NASA Astrophysics Data System (ADS)

This work reports on the development of a novel hybrid transition control method for single DBD plasma actuators. The experiments have been carried out on a natural laminar flow airfoil in a wind tunnel and combine two methods previously used for transition control purposes with DBD plasma actuators: boundary-layer stabilization by quasi-steady wall-parallel momentum addition, and active wave cancelation by linear superposition utilizing modulated momentum injection. For this purpose, the modulated body force is controlled using an improved extremum seeking controller based on an extended Kalman filter. Combining the two methods in a single actuator has advantages. Applied to 2-D Tollmien-Schlichting waves, the achievable transition delay in hybrid mode is significantly larger than the isolated effects, while the energy consumption remains almost unchanged compared to the case of continuous actuation. For a Reynolds number of , a transition delay of could be observed.

Kurz, A.; Goldin, N.; King, R.; Tropea, C.; Grundmann, S.

2013-11-01

455

Critical behaviours of contact near phase transitions  

PubMed Central

A central quantity of importance for ultracold atoms is contact, which measures two-body correlations at short distances in dilute systems. It appears in universal relations among thermodynamic quantities, such as large momentum tails, energy and dynamic structure factors, through the renowned Tan relations. However, a conceptual question remains open as to whether or not contact can signify phase transitions that are insensitive to short-range physics. Here we show that, near a continuous classical or quantum phase transition, contact exhibits a variety of critical behaviours, including scaling laws and critical exponents that are uniquely determined by the universality class of the phase transition, and a constant contact per particle. We also use a prototypical exactly solvable model to demonstrate these critical behaviours in one-dimensional strongly interacting fermions. Our work establishes an intrinsic connection between the universality of dilute many-body systems and universal critical phenomena near a phase transition. PMID:25346226

Chen, Y.-Y.; Jiang, Y.-Z.; Guan, X.-W.; Zhou, Qi

2014-01-01

456

Transit Terminal Facilities and Urban Rail Planning.  

National Technical Information Service (NTIS)

Contents: Guidelines and standards for the planning, design, and operation of bus park-and-ride facilities; Estimating the effects of residential joint-development policies on rail transit ridership; Analysis of fare-collection-system dependability; Bus t...

J. J. Mather, J. M. Lutin, B. P. Markowicz, D. I. Heimann, D. R. Miller

1983-01-01

457

Transition from Pediatric to Adult OI Care  

MedlinePLUS

... 2663 (301) 947-0083 Fax: (301) 947-0456 Internet: www.oif.org Email: bonelink@oif.org The ... and insurance options • Continue transition to career and financial independence • Plan for adult social, leisure, and recreational ...

458

Transition Matrix Elements for Pion Photoproduction  

E-print Network

We have obtained the transition matrix elements for pion photoproduction by considering the number of gamma matrices involved. The approach based on the most general conditions of gauge invariance, current conservation and transversality. The approach is fairly consistent with literatures.

Mohamed E. Kelabi

2007-03-20

459

Doppler Tomographic Observations of Exoplanet Transits  

NASA Astrophysics Data System (ADS)

Rapidly-rotating stars are not amenable to radial velocity confirmation of transiting planet candidates due to their broad stellar lines. An alternative approach is Doppler tomography, an extension of the Rossiter-McLaughlin technique to rapidly-rotating stars where the distortion of the stellar line shape during a transit is spectrally resolved. We have instituted a program of observations at McDonald Observatory to confirm and characterize transiting planet candidates discovered by the Kepler mission. In addition, we are observing selected previously known transiting planets. These observations also provide information on the spin-orbit misalignment of the star-planet system, an important statistical probe of planetary migration mechanisms. We present first results from these observations.

Johnson, Marshall C.; Cochran, W. D.

2013-01-01

460

Thermal transition temperature from twisted mass QCD  

E-print Network

We present the current status of lattice simulations with N_f=2 maximally twisted mass Wilson fermions at finite temperature. In particular, the determination of the thermal transition temperature is discussed.

Florian Burger; Ernst-Michael Ilgenfritz; Malik Kirchner; Maria Paola Lombardo; Michael Müller-Preussker; Owe Philipsen; Carsten Urbach; Lars Zeidlewicz

2010-09-20

461

PERFORMANCE OF THE AGS TRANSITION JUMP SYSTEM.  

SciTech Connect

The transition jump system has been indispensable to the high intensity proton operation of the AGS complex. Nevertheless, transition crossing remains one of the major hurdles as the accelerator complex intensity is pushed upward. To enhance the performance of the system ''quadrupole pumping'' in the Booster is used to minimize the necessary longitudinal dilution of the beam on the AGS injection porch. During the transition jump sextupole correctors at strategic locations are pulsed to minimize the effects of the chromatic non-linearity of the jump system. The available instrumentation for diagnosing the performance of the system will be described, along with installed hardware to counter the non-linear effects of the transition jump system.

AHRENS,L.A.; BRENNAN,J.M.; GLENN,J.W.; ROSER,T.; VAN ASSELT,W.K.

1999-03-29

462

Critical behaviours of contact near phase transitions.  

PubMed

A central quantity of importance for ultracold atoms is contact, which measures two-body correlations at short distances in dilute systems. It appears in universal relations among thermodynamic quantities, such as large momentum tails, energy and dynamic structure factors, through the renowned Tan relations. However, a conceptual question remains open as to whether or not contact can signify phase transitions that are insensitive to short-range physics. Here we show that, near a continuous classical or quantum phase transition, contact exhibits a variety of critical behaviours, including scaling laws and critical exponents that are uniquely determined by the universality class of the phase transition, and a constant contact per particle. We also use a prototypical exactly solvable model to demonstrate these critical behaviours in one-dimensional strongly interacting fermions. Our work establishes an intrinsic connection between the universality of dilute many-body systems and universal critical phenomena near a phase transition. PMID:25346226

Chen, Y-Y; Jiang, Y-Z; Guan, X-W; Zhou, Qi

2014-01-01

463

Critical behaviours of contact near phase transitions  

NASA Astrophysics Data System (ADS)

A central quantity of importance for ultracold atoms is contact, which measures two-body correlations at short distances in dilute systems. It appears in universal relations among thermodynamic quantities, such as large momentum tails, energy and dynamic structure factors, through the renowned Tan relations. However, a conceptual question remains open as to whether or not contact can signify phase transitions that are insensitive to short-range physics. Here we show that, near a continuous classical or quantum phase transition, contact exhibits a variety of critical behaviours, including scaling laws and critical exponents that are uniquely determined by the universality class of the phase transition, and a constant contact per particle. We also use a prototypical exactly solvable model to demonstrate these critical behaviours in one-dimensional strongly interacting fermions. Our work establishes an intrinsic connection between the universality of dilute many-body systems and universal critical phenomena near a phase transition.

Chen, Y.-Y.; Jiang, Y.-Z.; Guan, X.-W.; Zhou, Qi

2014-10-01

464

"Explosive Percolation" Transition is Actually Continuous  

E-print Network

The basic notion of percolation in physics assumes the emergence of a giant connected (percolation) cluster in a large disordered system when the density of connections exceeds some critical value. Until recently, the percolation phase transitions were believed to be continuous, however, in 2009, a remarkably different, discontinuous phase transition was reported in a new so-called "explosive percolation" problem. Each link in this problem is established by a specific optimization process. Here, employing strict analytical arguments and numerical calculations, we find that in fact the "explosive percolation" transition is continuous though with an uniquely small critical exponent of the percolation cluster size. These transitions provide a new class of critical phenomena in irreversible systems and processes.

R. A. da Costa; S. N. Dorogovtsev; A. V. Goltsev; J. F. F. Mendes

2010-09-13

465

Twist transition of nematic hyperbolic hedgehogs  

NASA Astrophysics Data System (ADS)

Stability of an idealized hyperbolic hedgehog in a nematic liquid crystal against a twist transition is investigated by extending the methodology of Rüdinger and Stark [Liq. Cryst. 26, 753 (1999), 10.1080/026782999204840], where the hedgehog is confined between two concentric spheres. In the ideal hyperbolic-hedgehog the molecular orientation is assumed to rotate proportionally with respect to the inclination angle, ? (and in the opposite sense). However, when splay, k11, and bend, k33, moduli differ this proportionality is lost and the liquid crystal deforms relative to the ideal with bend and splay. Although slight, these deformations are shown to significantly shift the transition if k11/k33 is small. By increasing the degree of confinement the twist transition can be inhibited, a characteristic both hyperbolic and radial hedgehogs have in common. The twist transition of a hyperbolic defect that accompanies a particle is found to be well predicted by the earlier stability analysis of a thick shell.

James, Richard; Fukuda, Jun-ichi

2014-04-01

466

Sharp phase transition and critical behaviour in  

E-print Network

of the classical RSW theorem. Keywords: dependent percolation, sharp phase transition, critical behaviour, duality, DaC model, RSW theorem, pc = 1/2. AMS 2000 Subject Classification: 60K35, 82B43, 82B20 E

Meester, Ronald

467

Improve Hospital-to-Home Transitions  

MedlinePLUS

... Navigation Bar Home Current Issue Past Issues Improve Hospital-to-Home Transitions Past Issues / Spring 2008 Table ... current health care system tends to focus on hospital care, with less emphasis on recovery and rehabilitation ...

468

Transitions in Na IIITransitions in Na III  

Microsoft Academic Search

The work of Blackford and Hibbert (1994 At.Data Nucl.Data Tables58 101-64) has been extended to provide oscillator strengths and transition probabilities for J?J' transitions amongst n = 2 and n = 3 levels of Na III. Configuration interaction wavefunctions, obtained with the code CIV3 in the Breit-Pauli approximation, and with additional correlation effects, have been constructed. Further semi-empirical corrections to

D. McPeake; A. Hibbert

2000-01-01

469

Evening Transition Observations in Phoenix, Arizona.  

NASA Astrophysics Data System (ADS)

Past research has suggested that the evening transition in complex topography typically has several main features, such as (a) continued weak upslope flows persisting 3-5 h after sunset (if the sidewalls of the valley prevent Coriolis-induced turning of winds), thus signifying delayed transition; (b) unsteady local stagnation and vertical mixing within tens of meters above the surface; and (c) transition of stagnation fronts to downslope/downvalley gravity currents during the evening hours, especially at higher-elevation (steeper) slopes, and their arrival at adjoining low-elevation gentle slopes as `slope breezes.' This transition process typically occurs in locales such as Phoenix, Arizona, which has expansive exposure to plains in one direction (to the west and south) and is adjacent to abrupt change in the terrain in other directions (primarily to the north and east). An analysis of wind records from several automated weather stations and a radar wind profiler for selected characteristic periods representing all four seasons and data from a previous major field campaign in the greater Phoenix valley illustrate (i) the shallow nature of transition flows that develop on a year-round basis during frequent clear, calm nights in the desert Southwest and their seasonal sensitivity; (ii) a spatial variation of transition times relative to the only first-order National Weather Service station in the region (Sky Harbor International Airport); (iii) the dependence of transition time (and hence the delay of transition) on the exposure, the elevation, and the magnitude of slope; and (iv) a possible heat-island influence. These observations are quantified using theoretical estimates, and the results are placed in the context of multiscale flows in urban basins.

Brazel, A. J.; Fernando, H. J. S.; Hunt, J. C. R.; Selover, N.; Hedquist, B. C.; Pardyjak, E.

2005-01-01

470

Cooperative relaxations\\/transitions in ferroelectric polymers  

Microsoft Academic Search

Dielectric relaxation and thermal transitions in ?-PVDF have been investigated by Thermo-Stimulated Current spectroscopy and\\u000a Differential Scanning Calorimetry respectively. A comparative study of spectra and thermograms has been performed.\\u000a \\u000a The relaxation mode associated with the glass transition of the true amorphous phase is characterized by relaxation times\\u000a obeying a compensation law due to cooperative molecular movements. A conformationally disordered structure

G. Teyssèdre; A. Bernès; C. Lacabanne

1993-01-01

471

Transition within a graduate nurse residency program.  

PubMed

As evidence of the effectiveness of these programs grows, nurse leaders feel the pressure to establish high-quality, yet cost-effective graduate nurse transition programs. In 2009, the authors developed an innovative program by incorporating transition theory, research results, stakeholder involvement, and the recommendations of the National Council of State Boards of Nursing. The graduate nurse residency program yielded positive outcomes, including stakeholder satisfaction and high retention rates. PMID:23061408

Varner, Kendra D; Leeds, Ruth A

2012-11-01

472

Electrically driven phase transition in magnetite nanostructures  

Microsoft Academic Search

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

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

2008-01-01

473

Glass transition in fluids with magnetic interactions  

NASA Astrophysics Data System (ADS)

The study of metallic glasses which exhibit magnetic interactions was mainly restricted to the amorphous solid regime and its properties. Here we study the glass transition in fluids where particles are endowed with spins, such that magnetic and positional degrees of freedom are coupled. Results for slowing down in the spin time-correlation functions are described, and the effects of magnetic fields on the glass transition are studied. Aging effects in such systems and the corresponding data collapse are presented and discussed.

Gutiérrez, Ricardo; Gupta, Bhaskar Sen; Procaccia, Itamar

2014-09-01

474

Thermomechanical properties of 3d transition metals  

SciTech Connect

The authors have investigated the density variation of the Einstein temperatures and elastic constants of the 3d transition metals. In this respect they have employed the transition metal (TM) pair potentials involving the sp contribution with an appropriate exchange and correlation function, the d-band broadening contribution and the d-band hybridization term. These calculations are aimed at testing the TM pair potentials in generating the quasilocal and local thermomechanical properties.

Karaoglu, B.; Rahman, S.M.M. (Sultan Qaboos Univ., Muscat (Oman). Dept. of Physics)

1994-05-15

475

Axion Dark Matter Detection using Atomic Transitions  

E-print Network

Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

Sikivie, P

2014-01-01

476

Axion Dark Matter Detection using Atomic Transitions  

E-print Network

Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

P. Sikivie

2014-09-09

477

Mechanical heating in the transition region  

NASA Technical Reports Server (NTRS)

Attention is focused on the energy balance in the transition region and the role that mechanical heating plays in determining the temperature density structure of this region in a stellar atmosphere. Because of its role as the interface layer through which mass and energy flow between the chromospheres and corona, direct deposition of mechanical energy is a relatively unimportant factor in the overall energy balance in the transition region, except in the uppermost layers where the temperature approaches coronal values.

Withbroe, G.

1981-01-01

478

Phase transitions in multiplicative competitive processes  

SciTech Connect

We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical mechanics. The theory is applicable to bacterial competition, predicting novel population dynamics near criticality.

Shimazaki, Hideaki; Niebur, Ernst [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Department of Neuroscience, Zanvyl Krieger Mind/Brain Institute, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2005-07-01

479

Making the transition from technologist to manager.  

PubMed

To prepare for the transition to management, technical personnel must (1) develop their administrative, communication, and interpersonal skills; (2) learn to delegate, and (3) learn management principles and concepts. This last activity can be accomplished through in-house management training programs, on-the-job training, or formal management degree programs. These activities will help increase the chances for success among technical personnel making the transition into management in a clinical or industrial setting. PMID:17190088

Goldberg, Jay R

2006-01-01

480

Connecting the vulcanization transition to percolation  

NASA Astrophysics Data System (ADS)

The vulcanization transition is addressed via a minimal replica-field-theoretic model. The appropriate long-wavelength behavior of the two- and three-point vertex functions is considered diagrammatically, to all orders in perturbation theory, and identified with the corresponding quantities in the Houghton-Reeve-Wallace field-theoretic approach to the percolation critical phenomenon. Hence, it is shown that percolation theory correctly captures the critical phenomenology of the vulcanization transition associated with the liquid and critical states.

Peng, Weiqun; Goldbart, Paul M.; McKane, Alan J.

2001-09-01

481

Notes on Black Hole Phase Transitions  

Microsoft Academic Search

In these notes we present a summary of existing ideas about phase transitions\\u000aof black hole spacetimes in semiclassical gravity and offer some thoughts on\\u000athree possible scenarios by which these transitions could take place. Our first\\u000atheme is ilustrated by a quantum atomic black hole system, generalizing to\\u000afinite-temperature a model originally offered by Bekenstein. In this\\u000aequilibrium atomic

G. J. Stephens; B. L. Hu

2001-01-01

482

Mismatch Induced Type Transition of a Superconductor  

E-print Network

We use the Ginzburg-Landau theory near the transition temperature in order to examine the behavior of an inhomogeneous superconductor in the presence of a magnetic field. We find that a transition from type I to type II superconductivity occurs. Furthermore we calculate the critical value of the mismatch and estimate the contributions of the fluctuations of the condensate and the higher order terms in the Ginzburg-Landau framework.

Ioannis Giannakis; Defu Hou; Mei Huang; Hai-cang Ren

2006-03-09

483

Mechanism of the conformational transition of melittin.  

PubMed

It is known that, while melittin at micromolar concentrations is unfolded under conditions of low ionic strength at neutral pH, it adopts a tetrameric alpha-helical structure under conditions of high ionic strength, at alkaline pH, or at high peptide concentrations. To understand the mechanism of the conformational transition of melittin, we examined in detail the conformation of melittin under various conditions by far-UV circular dichroism at 20 degrees C. We found that the helical conformation is also stabilized by strong acids such as perchloric acid. The effects of various acids varied largely and were similar to those of the corresponding salts, indicating that the anions are responsible for the salt- or acid-induced transitions. The order of effectiveness of various monovalent anions was consistent with the electroselectivity series of anions toward anion-exchange resins, indicating that the anion binding is responsible for the salt- or acid-induced transitions. From the NaCl-, HCl-, and alkaline pH-induced conformational transitions, we constructed a phase diagram of the anion- and pH-dependent conformational transition. The phase diagram was similar in shape to that of acid-denatured apomyoglobin [Goto, Y., & Fink, A.L. (1990) J. Mol. Biol. 214, 803-805] or that of the amphiphilic Lys, Leu model polypeptide [Goto, Y., & Aimoto, S. (1991) J. Mol. Biol. 218, 387-396], suggesting a common mechanism of the conformational transition. The anion-, pH-, and peptide concentration-dependent conformational transition of melittin was explained on the basis of an equation in which the conformational transition is linked to proton and anion binding to the titratable groups. PMID:1731930

Goto, Y; Hagihara, Y

1992-01-28

484

Mass Transit Living Lab: Analyze the Data  

NSDL National Science Digital Library

Students go through the logical process of quantitatively analyzing real-world transit data. They gain experience identifying problems with the current design based upon their earlier observations and experiences in activities 1 and 2. Students discuss the flaws that they find in the system. This activity requires the use of the Mass Transit Living Labâa web portal to interactive train traffic data for a major metropolitan city.

Civil And Environmental Engineering Department

485

Transition from galactic to extragalactic cosmic rays  

E-print Network

The transition from galactic to extragalactic cosmic rays is discussed. One of critical indications for transition is given by the Standard Model of Galactic cosmic rays, according to which the maximum energy of acceleration for iron nuclei is of order of $E_{\\rm Fe}^{\\rm max} \\approx 1\\times 10^{17}$ eV. At $E > E_{\\rm Fe}^{\\rm max}$ the spectrum is predicted to be very steep and thus the Standard Model favours the transition at energy not much higher than $E_{\\rm Fe}^{\\rm max}$. As observations are concerned there are two signatures of transition: change of energy spectra and elongation rate (depth of shower maximum in the atmosphere $X_{\\rm max}$ as function of energy). Three models of transition are discussed: dip-based model, mixed composition model and ankle model. In the latter model the transition occurs at the observed spectral feature, ankle, which starts at $E_a \\approx 1\\times 10^{19}$ eV and is characterised by change of mass compostion from galactic iron to extragalactic protons. In the dip model the transition occures at the second knee observed at energy $(4 -8)\\times 10^{17}$ eV and is characterised by change of mass composition from galactic iron to extragalactic protons. The mixed composition model describes transition at $E \\sim 3\\times 10^{18}$ eV with mass composition changing from galactic iron to extragactic mixed composition of different nuclei. These models are confronted with observational data on spectra and elongation rates from different experiments, including Auger.

V. Berezinsky

2007-10-15

486

Update on Discovery Transition from Kevin Templin (2/2)  

NASA Video Gallery

NASA Public Affairs Officer Kyle Herring continues his discussion with Kevin Templin, the Transition Integration Manager for the Space Shuttle Program Transition and Retirement Office, about the wo...

487

Serpin latency transition at atomic resolution.  

PubMed

Protease inhibition by serpins requires a large conformational transition from an active, metastable state to an inactive, stable state. Similar reactions can also occur in the absence of proteases, and these latency transitions take hours, making their time scales many orders of magnitude larger than are currently accessible using conventional molecular dynamics simulations. Using a variational path sampling algorithm, we simulated the entire serpin active-to-latent transition in all-atom detail with a physically realistic force field using a standard computing cluster. These simulations provide a unifying picture explaining existing experimental data for the latency transition of the serpin plasminogen activator inhibitor-1 (PAI-1). They predict a long-lived intermediate that resembles a previously proposed, partially loop-inserted, prelatent state; correctly predict the effects of PAI-1 mutations on the kinetics; and provide a potential means to identify ligands able to accelerate the latency transition. Interestingly, although all of the simulated PAI-1 variants readily access the prelatent intermediate, this conformation is not populated in the active-to-latent transition of another serpin, ?1-antitrypsin, which does not readily go latent. Thus, these simulations also help elucidate why some inhibitory serpin families are more conformationally labile than others. PMID:25313058

Cazzolli, Giorgia; Wang, Fang; A Beccara, Silvio; Gershenson, Anne; Faccioli, Pietro; Wintrode, Patrick L

2014-10-28

488

Higgs couplings and electroweak phase transition  

NASA Astrophysics Data System (ADS)

We argue that extensions of the Standard Model (SM) with a strongly first-order electroweak phase transition generically predict significant deviations of the Higgs couplings to gluons, photons, and Z bosons from their SM values. Precise experimental measurements of the Higgs couplings at the LHC and at the proposed next-generation facilities will allow for a robust test of the phase transition dynamics. To illustrate this point, in this paper we focus on the scenario in which loops of a new scalar field are responsible for the first-order phase transition, and study a selection of benchmark models with various SM gauge quantum numbers of the new scalar. We find that the current LHC measurement of the Higgs coupling to gluons already excludes the possibility of a first-order phase transition induced by a scalar in a sextet, or larger, representation of the SU(3) c . Future LHC experiments (including HL-LHC) will be able to definitively probe the case when the new scalar is a color triplet. If the new scalar is not colored, an electron-positron Higgs factory, such as the proposed ILC or TLEP, would be required to test the nature of the phase transition. The extremely precise measurement of the Higgsstrahlung cross section possible at such machines will allow for a comprehensive and definitive probe of the possibility of a first-order electroweak phase transition in all models we considered, including the case when the new scalar is a pure gauge singlet.

Katz, Andrey; Perelstein, Maxim

2014-07-01

489

Helix-Coil Transitions in Nonpolar Peptides  

NASA Astrophysics Data System (ADS)

A Monte Carlo simulation of the folding and unfolding of a two-dimensional model polypeptide, which has ?-helical motifs, in nonpolar side chains were carried out. The terms that approximate the effect of the hydrophobic interaction in a solvent are phenomenologically included. Only three states were considered for each unit: extended with hydrogen bonds, turns and coils. We investigated the nature of hydration in the assembly process of ?-helical stretches. The conversion exhibited transitions between three states: random coils (C) at a high temperature, helix bundles (B) at a medium temperature, and ?-helices (H) without lateral hydrophobic bonds at a low temperature. Small hydrophobic interactions result in only the H-C transition lacking the B state. On the other hand, as the hydrophobic effect strengthens, the B state appears at a medium temperature. The B-C and B-H transitions appear as an all-or-none-type transition and a gradually diffused type transition, respectively. This problem is related to protein folding. In the simulation performed in this study, we discuss the cold denaturation of proteins from the viewpoint of B-H transitions.

Kanô, Fumiaki

2007-04-01

490

Higgs Couplings and Electroweak Phase Transition  

E-print Network

We argue that extensions of the Standard Model (SM) with a strongly first-order electroweak phase transition generically predict significant deviations of the Higgs couplings to gluons, photons, and Z bosons from their SM values. Precise experimental measurements of the Higgs couplings at the LHC and at the proposed next-generation facilities will allow for a robust test of the phase transition dynamics. To illustrate this point, in this paper we focus on the scenario in which loops of a new scalar field are responsible for the first-order phase transition, and study a selection of benchmark models with various SM gauge quantum numbers of the new scalar. We find that the current LHC measurement of the Higgs coupling to gluons already excludes the possibility of a first-order phase transition induced by a scalar in a sextet, or larger, representation of the SU(3)_c. Future LHC experiments (including HL-LHC) will be able to definitively probe the case when the new scalar is a color triplet. If the new scalar is not colored, an electron-positron Higgs factory, such as the proposed ILC or TLEP, would be required to test the nature of the phase transition. The extremely precise measurement of the Higgsstrahlung cross section possible at such machines will allow for a comprehensive and definitive probe of the possibility of a first-order electroweak phase transition in all models we considered, including the case when the new scalar is a pure gauge singlet.

Andrey Katz; Maxim Perelstein

2014-01-08

491

Phase Transitions, Domain Walls, and Dark Matter  

NASA Astrophysics Data System (ADS)

We discuss possible roles in the Early Universe of the electroweak (EW) phase transition, which endows masses to the various particles, and the QCD phase transition, which gives rise to quark confinement and chiral symmetry breaking. Both phase transitions are well-established phenomena in the standard model of particle physics. Presumably, the EW phase transition would have taken place in the early universe at around 10-11sec, or at the temperature of about 300 GeV while QCD phase transition occurred between 10-5sec and 10-4sec, or at about 150 MeV. In this article, I wish to model the EW or QCD phase transition in the early universe as driven by a complex scalar field with spontaneous symmetry breaking such that the continuous degeneracy of the true ground states can be well represented. Specific interest has been directed to nucleation of domains, production of domain walls, and subsequent re-organization of domain walls resulting in "domain-wall nuggets". It is suggested that the domain-wall nuggets contribute to dark matter in the present Universe.

Hwang, W.-Y. P.

492

Explosive synchronization transitions in complex neural networks.  

PubMed

It has been recently reported that explosive synchronization transitions can take place in networks of phase oscillators [Go?mez-Garden?es et al. Phys. Rev. Lett. 106, 128701 (2011)] and chaotic oscillators [Leyva et al. Phys. Rev. Lett. 108, 168702 (2012)]. Here, we investigate the effect of a microscopic correlation between the dynamics and the interacting topology of coupled FitzHugh-Nagumo oscillators on phase synchronization transition in Baraba?si-Albert (BA) scale-free networks and Erdo?s-Re?nyi (ER) random networks. We show that, if natural frequencies of the oscillations are positively correlated with node degrees and the width of the frequency distribution is larger than a threshold value, a strong hysteresis loop arises in the synchronization diagram of BA networks, indicating the evidence of an explosive transition towards synchronization of relaxation oscillators system. In contrast to the results in BA networks, in more homogeneous ER networks, the synchronization transition is always of continuous type regardless of the width of the frequency distribution. Moreover, we consider the effect of degree-mixing patterns on the nature of the synchronization transition, and find that the degree assortativity is unfavorable for the occurrence of such an explosive transition. PMID:24089960

Chen, Hanshuang; He, Gang; Huang, Feng; Shen, Chuansheng; Hou, Zhonghuai

2013-09-01

493

Dynamic transition rules for geographical cellular automata  

NASA Astrophysics Data System (ADS)

There is rapid development of CA models for simulation of land use patterns and urban systems recently. Traditional models use the uniform transition rules in large areas or at long times. These models have limitations because they use the same factors and weights in different places or times while these factors and weights vary spatially. This paper presents the method of using dynamic transition rules for producing more reliable urban simulation. The advantages of dynamic transition rules are apparent in this paper. First, it uses different factors and weights in different regions which are consistent with actual urban systems. Second, the main factors can be obtained from the dynamic transition rules in different regions which may produce different urban development patterns. Based on the stepwise logistical regression model, dynamic transition rules were obtained for simulating the evolution of the urban systems in five towns of the Dongguan city from 1988 to 2004. Compared with the general CA model, the simulation precision is improved by using this method. From the factors and weights of dynamic transition rules, three kinds of development patterns were obtained: center development pattern, road development pattern and center-road development pattern.

Yang, Q. S.; Li, X.

2008-10-01

494

Explosive synchronization transitions in complex neural networks  

NASA Astrophysics Data System (ADS)

It has been recently reported that explosive synchronization transitions can take place in networks of phase oscillators [Gómez-Gardeñes et al. Phys. Rev. Lett. 106, 128701 (2011)] and chaotic oscillators [Leyva et al. Phys. Rev. Lett. 108, 168702 (2012)]. Here, we investigate the effect of a microscopic correlation between the dynamics and the interacting topology of coupled FitzHugh-Nagumo oscillators on phase synchronization transition in Barabási-Albert (BA) scale-free networks and Erdös-Rényi (ER) random networks. We show that, if natural frequencies of the oscillations are positively correlated with node degrees and the width of the frequency distribution is larger than a threshold value, a strong hysteresis loop arises in the synchronization diagram of BA networks, indicating the evidence of an explosive transition towards synchronization of relaxation oscillators system. In contrast to the results in BA networks, in more homogeneous ER networks, the synchronization transition is always of continuous type regardless of the width of the frequency distribution. Moreover, we consider the effect of degree-mixing patterns on the nature of the synchronization transition, and find that the degree assortativity is unfavorable for the occurrence of such an explosive transition.

Chen, Hanshuang; He, Gang; Huang, Feng; Shen, Chuansheng; Hou, Zhonghuai

2013-09-01

495

Explosive synchronization transitions in complex neural network  

E-print Network

It has been recently reported that explosive synchronization transitions can take place in networks of phase oscillators [G\\'omez-Garde\\~nes \\emph{et al.} Phys.Rev.Letts. 106, 128701 (2011)] and chaotic oscillators [Leyva \\emph{et al.} Phys.Rev.Letts. 108, 168702 (2012)]. Here, we investigate the effect of a microscopic correlation between the dynamics and the interacting topology of coupled FitzHugh-Nagumo oscillators on phase synchronization transition in Barab\\'asi-Albert (BA) scale-free networks and Erd\\"os-R\\'enyi (ER) random networks. We show that, if the width of distribution of natural frequencies of the oscillations is larger than a threshold value, a strong hysteresis loop arises in the synchronization diagram of BA networks due to the positive correlation between node degrees and natural frequencies of the oscillations, indicating the evidence of an explosive transition towards synchronization of relaxation oscillators system. In contrast to the results in BA networks, in more homogeneous ER networks the synchronization transition is always of continuous type regardless of the the width of the frequency distribution. Moreover, we consider the effect of degree-mixing patterns on the nature of the synchronization transition, and find that the degree assortativity is unfavorable for the occurrence of such an explosive transition.

Hanshuang Chen; Feng Huang; Chuansheng Shen; Zhonghuai Hou

2012-04-09

496

Transit Photometry with the LCOGT Network  

NASA Astrophysics Data System (ADS)

Within a single year, we deployed and commissioned a total of seven 1m telescopes to three sites (McDonald Observatory, CTIO and SAAO). These are complemented by two existing 2m telescopes, located in the northern (Haleakala) and southern (Siding Spring Observatory) hemispheres. Before the end of 2013, one additional 1m telescope will be deployed at McDonald Observatory, and two at Siding Spring Observatory, which will complete the southern ring and enable continuous LCOGT dark time in the southern hemisphere. We present transit observations acquired at each site with currently-deployed 1m telescopes. These data demonstrate some of the network's unique capabilities, such as simultaneous transit observations from multiple sites and construction of full transits by combining partial transit light curves from two sites. Such exercises pave the path toward searching for and characterizing transits of long period exoplanets, simultaneous multi-color transit observations, as well as studying spot distributions and rotation periods of exoplanet host stars using the LCOGT network.

Dragomir, Diana; Eastman, Jason; Brown, Tim; Street, Rachel; Lister, Tim; Tsapras, Yannis; Ross, Rachel; Fulton, Benjamin

2013-07-01

497

The ?-? phase transition in volcanic cristobalite  

PubMed Central

Cristobalite is a common mineral in volcanic ash produced from dome-forming eruptions. Assessment of the respiratory hazard posed by volcanic ash requires understanding the nature of the cristobalite it contains. Volcanic cristobalite contains coupled substitutions of Al3+ and Na+ for Si4+; similar co-substitutions in synthetic cristobalite are known to modify the crystal structure, affecting the stability of the ? and ? forms and the observed transition between them. Here, for the first time, the dynamics and energy changes associated with the ?–? phase transition in volcanic cristobalite are investigated using X-ray powder diffraction with simultaneous in situ heating and differential scanning calorimetry. At ambient temperature, volcanic cristobalite exists in the ? form and has a larger cell vo