Science.gov

Sample records for coster-kronig transitions

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    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.

  2. Evidence for N 2N 3N 45 super coster kronig processes in metallic Nb, Mo, Ru and Rh

    NASA Astrophysics Data System (ADS)

    Nyholm, Ralf; M»rtensson, Nils

    1980-09-01

    The 4p photoelectron spectra of metallic Nb, Mo, Ru and Rh have been recorded. By use of a deconvolution procedure it is shown that the 4p 1/2 spin-orbit component has a linewidth which significantly exceeds that of the 4p 3/2 component. This suggests that N 2N 3N 45 super Coster Kronig processes give a considerable contribution to the decay rata of the 4p 1/2 hole state.

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

    SciTech Connect

    Chauhan, Yogeshwar; Puri, Sanjiv

    2008-01-15

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

  4. Dirac-Fock calculations of K -, L -, and M -shell fluorescence and Coster-Kronig yields for Ne, Ar, Kr, Xe, Rn, and Uuo

    NASA Astrophysics Data System (ADS)

    Sampaio, J. M.; Madeira, T. I.; Guerra, M.; Parente, F.; Santos, J. P.; Indelicato, P.; Marques, J. P.

    2015-05-01

    In this work, we calculated the fluorescence and Coster-Kronig yields for the K shell and the L and M subshells of Ne, Ar, Kr, Xe, Rn, and Uuo (Z =118 ), using a Dirac-Fock model which provides a better description of the electron-electron interaction than previous approaches, and is suitable to handle superheavy elements. The results are compared with available data from other authors. In what concerns Ne, Ar, Kr, Xe, and Rn K shells, the obtained results are in very good agreement with the adopted values of Krause [25] and with experiment when available. For the L subshells, our results are in line with existing ones. For the M subshells and for all shells of Uuo there are no previous experimental and theoretical results to compare to our calculations.

  5. M sub-shell fluorescence and Coster-Kronig yield data generation for elements, 57≤Z≤90 (computer code ‘MFCKYLD')

    NASA Astrophysics Data System (ADS)

    Kaur, Gurpreet; Mittal, Raj

    2014-01-01

    M subshell fluorescence yield (ωMi, i=1-5) and Coster-Kronig yield (fMij, i=1-4, j=2-5) values have been generated for elements with Z, 57≤Z≤90. Keeping in view the importance of ωMi and fMij for M X-ray productions in the region Z>56, the interpolation of non-relativistic data of McGuire [Phys. Rev. A 1972;5:1043-7] in the region Z=57-90 as well as relativistic data of Chen et al. [Phys. Rev. A 1980;21:449-53 and 1983;27:2989-94] in the region Z=67-90 was attempted. The agreement between the generated data and the actual ones supported the adopted procedure. Subsequently, a computer software code MFCKYLD was developed to generate the yield values on computer terminal or in file for both non-relativistic and relativistic data just by entering the atomic number Z of the element through keyboard or file. The precision of present procedure that relies on the deviation of fitted values from the actual ones was found far better than the earlier fitted data.

  6. X-ray transitions in highly charged neonlike ions

    SciTech Connect

    Beiersdorfer, P.; von Gjoeler, S.; Bitter, M.; Hinnov, E.; Bell, R.; Bernabei, S.; Felt, J.; Hill, K.W.; Hulse, R.; Stevens, J.; Suckewer, S.; Timberlake, J.; Wouters, A.; Chen, M.H.; Scofield, J.H.; Dietrich, D.D.; Gerassimenko, M.; Silver, E.; Walling, R.S.; Hagelstein, P.L.

    1987-11-01

    Wavelength measurements of n=3 to n=2 transitions in neonlike Xe/sup 44 +/, La/sup 47 +/, Nd/sup 50 +/, and Eu/sup 53 +/ have been made using a high-resolution Bragg-crystal spectrometer on the Princeton Large Torus tokamak. The measurements cover the wavelength regions 2.00 to 3.00 (angstrom) and include the electric dipole, and the electric and magnetic quadrupole transitions. The measured wavelengths are compared to energy levels obtained from a multiconfigurational Dirac-Fock calculation. Systematic differences between the experimental and theoretical values are found, which vary smoothly with atomic number. The magnitude of the differences depends on the particular type of transition and ranges from -2.8 eV to +2.2 eV. Inclusion of electron correlation corrections due to ground state correlations and (super) Coster-Kronig type fluctuations in the theoretical energies is shown to reduce the differences for some but not all types of transitions.

  7. Reexamination of M2,3 atomic level widths and L1M2,3 transition energies of elements 69?Z?95

    NASA Astrophysics Data System (ADS)

    Fennane, K.; Berset, M.; Dousse, J.-Cl.; Hoszowska, J.; Raboud, P.-A.; Campbell, J. L.

    2013-11-01

    We report on high-resolution measurements of the photoinduced L1M2 and L1M3 x-ray emission lines of 69Tm, 70Yb, 71Lu, 73Ta, 74W, 75Re, 77Ir, 81Tl, 83Bi, and 95Am. From the linewidths of the measured transitions an accurate set of M2 and M3 level widths is determined assuming for the L1 level widths the values reported by Raboud [P.-A. Raboud et al., Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.65.022512 65, 022512 (2002)]. Furthermore, the present experimental M2,3 data set is extended to 80Hg, 90Th, and 92U, using former L1M2,3 high-resolution x-ray emission spectroscopy measurements performed by our group. A detailed comparison of the M2 and M3 level widths determined in the present work with those recommended by Campbell and Papp [J. L. Campbell and T. Papp, At. Data Nucl. Data TablesADNDAT0092-640X10.1006/adnd.2000.0848 77, 1 (2001)] and other available experimental data as well as theoretical predictions is done. The observed abrupt changes of the M2,3 level widths versus atomic number Z can be explained satisfactorily by the cutoffs and onsets of the M2M4N1, respectively M3M4N3,4,5 and M3M5N2,3 Coster-Kronig transitions deduced from the semiempirical (Z+1) approximation. As a spin-off result of this study, precise L1M2 and L1M3 transition energies are obtained for the investigated elements. A very good agreement with transition energies calculated within the many-body perturbation theory is found.

  8. Interpretation of the silver L X-ray spectrum

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    Analysis of the Ag L-series X-ray spectrum has been performed, based on relaxed-orbital relativistic transition-energy calculations. Satellite energies were computed in intermediate coupling. It is found that satellites arising from LN double-hole states generally fall within the natural width of the parent diagram lines. Contrary to previous assumption, the observed high-energy satellites are due to LM double-hole states produced by L1-L3M4,5 Coster-Kronig transitions and by shakeoff. The observed peak structure in the satellite spectrum is due to multiplet splitting of the initial and final double-hole states. Theoretical L1-L3M4,5 transition rates based on the Coster-Kronig energies computed by Chen et al. (1977) are closer to experiment than previous results, but still are too large by a factor of about 2, indicating an as-yet undetected flaw in the theory.

  9. Photon induced L3 vacancy alignment at tuned photon energies

    NASA Astrophysics Data System (ADS)

    Bansal, Himani; Kaur, Gurpreet; Tiwari, Manoj K.; Mittal, Raj

    2016-04-01

    Photon induced L3 X-ray measurements for Lα/Lℓ cross-section ratios in elements, 66 ⩽ Z ⩽ 83, at tuned photon energies on synchrotron Beamline-16 at Indus-2, India have been used to study the effect of Coster-Kronig (CK) transitions and photon energies on alignment of L3 vacancies. Certainty and reliability of the measurements were checked from comparison of measured Lα and Lℓ fluorescence cross-sections at E1 excitation with available theoretical/empirical/experimental values that required additional measurements for source, geometry and efficiency factor S0GɛLα/ℓ in the used set-up. Fall/rise trend of the ratios with energy for different Z's was found to resemble the off/on-set pattern of CK transitions as pointed out by Bambynek et al. and Campbell. Evaluated alignment parameter A2 values are very much within the limits, 0.05 Coster-Kronig corrected A2) variation with energy for Dy, W, Pt, Hg and Bi resembles our previously reported theoretical patterns that lends mutual support for both current measurements and earlier theoretical results.

  10. K, L, and M shell datasets for PIXE spectrum fitting and analysis

    NASA Astrophysics Data System (ADS)

    Cohen, David D.; Crawford, Jagoda; Siegele, Rainer

    2015-11-01

    Routine PIXE analysis programs, like GUPIX, GEOPIXE and PIXAN generally perform at least two key functions firstly, the fitting of K, L and M characteristic lines X-ray lines to a background, including unfolding of overlapping lines and secondly, the use of a fitted primary Kα, Lα or Mα line area to determine the elemental concentration in a given matrix. To achieve these two results to better than 3-5% the data sets for fluorescence yields, emission rates, Coster-Kronig transitions and ionisation cross sections should be determined to better than 3%. There are many different theoretical and experimental K, L and M datasets for these parameters. How they are applied and used in analysis programs can vary the results obtained for both fitting and concentration determinations. Here we discuss several commonly used datasets for fluorescence yields, emission rates, Coster-Kronig transitions and ionisation cross sections for K, L and M subshells and suggests an optimum set to obtain consistent results for PIXE analyses across a range of elements with atomic numbers from 5 ⩽ Z ⩽ 100.

  11. Transitions.

    ERIC Educational Resources Information Center

    Field, David; And Others

    1992-01-01

    Includes four articles: "Career Aspirations" (Field); "Making the Transition to a New Curriculum" (Baker, Householder); "How about a 'Work to School' Transition?" (Glasberg); and "Technological Improvisation: Bringing CNC to Woodworking" (Charles, McDuffie). (SK)

  12. L/M sub-shell measurements on INDUS-2 beam line BL16

    NASA Astrophysics Data System (ADS)

    Singla, Raj Mittal

    2015-06-01

    Beamline BL-16 on INDUS-2 at RRCAT, Indore has been employed for M sub shell measurements on Pt, Au, Hg, Pb, Th and U at 8 and 10 keV photon energies to determine M sub-shell X-ray emission cross-sections and for L sub-shell measurements on Dy, Ho, Er, Lu, Ta, W, Pt, Au, Hg, Pb and Bi with selective creation of electron vacancies in individual sub-shells to derive L Coster-Kronig (CK) yield values. The cross sections have been measured for the first time. The determined L sub-shell CK yields were used to explore some details of CK transitions.

  13. L/M sub-shell measurements on INDUS-2 beam line BL16

    SciTech Connect

    Singla, Raj Mittal

    2015-06-24

    Beamline BL-16 on INDUS-2 at RRCAT, Indore has been employed for M sub shell measurements on Pt, Au, Hg, Pb, Th and U at 8 and 10 keV photon energies to determine M sub-shell X-ray emission cross-sections and for L sub-shell measurements on Dy, Ho, Er, Lu, Ta, W, Pt, Au, Hg, Pb and Bi with selective creation of electron vacancies in individual sub-shells to derive L Coster-Kronig (CK) yield values. The cross sections have been measured for the first time. The determined L sub-shell CK yields were used to explore some details of CK transitions.

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

    SciTech Connect

    Martinez, Filiberto; Miranda, Javier

    2013-07-03

    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.

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

    NASA Astrophysics Data System (ADS)

    Martínez, Filiberto; Miranda, Javier

    2013-07-01

    Preliminary results obtained in experiments carried out with an x-ray spectrometer built at the Instituto de Física 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 (ωLi) and Coster-Kronig transition probabilities (fij) 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.

  16. L X-ray intensity ratios for high Z elements induced with X-ray tube

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Xu, Zhongfeng; Zhang, Limin

    2015-07-01

    We have studied the intensity ratios I(Lα1,2)/I(Lβ1,2), I(Lα1,2)/I(Lγ) and I(Lβ1,2)/I(Lγ) for elements Ta, W, Au and Pb by 13.1 keV bremsstrahlung radiation. In this work, experimental values were compared with the theoretical results and other experimental results. Theoretical results of the intensity ratios were calculated with theoretical subshell photoionization cross sections, fractional X-ray emission rates, fluorescence yields, and Coster-Kronig transition probabilities. Good agreement can be observed between experimental values and theoretical results. Comparing with L1 and L2 subshells, the ionization cross section of L3 subshell shows a large increase for Ta and W with the variation of excitation energy from 59.5 keV to 13.1 keV.

  17. PIXEF: The Livermore PIXE spectrum analysis package

    SciTech Connect

    Antolak, A.J.; Bench, G.S.

    1993-07-01

    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.

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

    SciTech Connect

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

    2010-01-05

    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.

  19. 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)

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

    1975-01-01

    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.

  20. 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

    Fernandez-Varea, Jose M.; Segui, Silvina; Dingfelder, Michael

    2011-02-15

    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.

  1. Measurement of relative L X-ray intensity ratio following radioactive decay and photoionization

    NASA Astrophysics Data System (ADS)

    Yalçın, P.; Porikli, S.; Kurucu, Y.; Şahin, Y.

    2008-05-01

    The measurements of the L X-ray intensity ratio I (Lα) / I (Lβ), I (Lα) / I (Lγ), I (Lα) / I (Lι), I (Lβ) / I (Lγ) and I (Lι) / I (Lγ) for elements Dy, Ho, Yb, W, Hg, Tl and Pb were experimentally determined both by photon excitation, in which 59.5 keV γ-rays from a filtered radioisotope 241Am was used, and by the radioactive decay of 160Tb, 160Er, 173Lu, 182Re, 201Tl, 203Pb and 207Bi. L X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the calculated theoretical values. Theoretical values of the I (Lα / Lβ), I (Lα / Lγ), I (Lα / Lι), I (Lβ / Lγ) and I (Lι / Lγ) intensity ratios were calculated using theoretically tabulated values of subshell photoionization cross-section, fluorescence yield, fractional X-ray emission rates, Coster-Kronig transition probabilities. It was observed that present values agree with previous theoretical and other available experimental results.

  2. Rates of exponential decay in systems of discrete energy levels by Stieltjes imaging

    SciTech Connect

    Craigie, Jacob; Hammad, Ali; Cooper, Bridgette; Averbukh, Vitali

    2014-07-07

    An isolated bound state coupled to a continuum shows an exponential decay of its survival probability. Rates of the exponential decay occurring due to the bound-continuum coupling can be recovered from discretized continuum (L{sup 2}) calculations using a computational technique known as Stieltjes-Chebyshev moment theory or Stieltjes imaging. At the same time, some genuinely discrete level systems, e.g., Bixon-Jortner model, also show an exponential (or approximately exponential) decay of the initially populated level before the onset of quantum revivals. Here, we demonstrate numerically that Stieltjes imaging can be used for calculation of the rates of the exponential decay in such discrete level systems. We apply the Stieltjes imaging technique to the approximately exponential decay of inner-valence vacancies in trans-butadiene in order to show that the breakdown of the molecular orbital picture of ionization in the inner valence region can be physically interpreted as an energy-forbidden Coster-Kronig transition.

  3. VIBA-Lab 3.0: Computer program for simulation and semi-quantitative analysis of PIXE and RBS spectra and 2D elemental maps

    NASA Astrophysics Data System (ADS)

    Orlić, Ivica; Mekterović, Darko; Mekterović, Igor; Ivošević, Tatjana

    2015-11-01

    VIBA-Lab is a computer program originally developed by the author and co-workers at the National University of Singapore (NUS) as an interactive software package for simulation of Particle Induced X-ray Emission and Rutherford Backscattering Spectra. The original program is redeveloped to a VIBA-Lab 3.0 in which the user can perform semi-quantitative analysis by comparing simulated and measured spectra as well as simulate 2D elemental maps for a given 3D sample composition. The latest version has a new and more versatile user interface. It also has the latest data set of fundamental parameters such as Coster-Kronig transition rates, fluorescence yields, mass absorption coefficients and ionization cross sections for K and L lines in a wider energy range than the original program. Our short-term plan is to introduce routine for quantitative analysis for multiple PIXE and XRF excitations. VIBA-Lab is an excellent teaching tool for students and researchers in using PIXE and RBS techniques. At the same time the program helps when planning an experiment and when optimizing experimental parameters such as incident ions, their energy, detector specifications, filters, geometry, etc. By "running" a virtual experiment the user can test various scenarios until the optimal PIXE and BS spectra are obtained and in this way save a lot of expensive machine time.

  4. The origin of the resistance change in GeSbTe films

    SciTech Connect

    Jang, Moon Hyung; Park, Seung Jong; Park, Sung Jin; Cho, Mann-Ho; Kurmaev, E. Z.; Finkelstein, L. D.; Chang, Gap Soo

    2010-10-11

    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.

  5. L X-ray production cross-section ratios for protons incident on high- Z atoms: A test of ECPSSR theory and newly recommended vacancy de-excitation parameters

    NASA Astrophysics Data System (ADS)

    Jones, B. N.; Campbell, J. L.

    2007-05-01

    The X-ray intensity ratios Lβ/Lα and Lγ/Lα for six heavy elements have been measured using a Si(Li) detector coupled to both analog and digital signal processors. The proton energies were chosen to ensure that possible united atom (UA) and intra-shell (IS) effects would be small, thereby ensuring that the experiments were a direct test of the ECPSSR together with the L subshell fluorescence and Coster-Kronig probabilities. Careful attention was paid to reducing recognized uncertainties in the fitting of the spectra, with the desired intensity ratios being extracted from a procedure that assumed the DF radiative transition rates of Scofield to be correct. Experiment and ECPSSR theory agree closely when the fluorescence and CK probabilities from a recent critical review are adopted in preference to those commonly used in earlier work. This result provides a significant improvement in the database used for PIXE analysis, and it paves the way for more definitive studies at lower proton energies, aimed at testing predicted UA and IS corrections.

  6. Transitional objects in transition.

    PubMed

    Elmhirst, S I

    1980-01-01

    Winnicott's original definition of a transitional object was that it is inanimate, is endowed by the infant with special properties and is of value in the developmental task of acknowledging that Mother (or her breast) is alive, is not a physical part of the baby, nor yet its external possession. I have tried in this short paper to show how a disservice has been done to Winnicott's original perception of the significance of transitional objects, by broadening the concept of transitional phenomena too far in a way which actually diminishes their value in understanding the growth of the mind. Further study and discussion is needed of the complex role of the baby's suck-rag, elucidation of which will be furthered by adherence to a more specific definition. Clinical material is present to illustrate this claim. PMID:7440076

  7. Transition Planning

    ERIC Educational Resources Information Center

    Statfeld, Jenna L.

    2011-01-01

    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…

  8. Transiting Exoplanets

    NASA Astrophysics Data System (ADS)

    Haswell, Carole A.

    2010-07-01

    1. Our solar system from afar; 2. Exoplanet discoveries by the transit method; 3. What the transit lightcurve tells us; 4. The transiting exoplanet population; 5. Transmission spectroscopy and Rossiter-McLaughlin effect; 6. Secondary eclipses and phase variations; 7. Transit timing variations and orbital dynamics; 8. Brave new worlds: the future; Index.

  9. Transition Planning.

    ERIC Educational Resources Information Center

    Fowler, Susan A.

    1988-01-01

    Four exemplary programs that effectively plan and coordinate transitions between early intervention programs and preschool/elementary programs are described. They include Project BEST (Building Effective School Transitions), Projects STEPS (Sequenced Transition to Education in the Public School), Project TEEM (Transitioning into the Elementary…

  10. Transition & Beyond

    MedlinePlus

    ... that are associated with Down syndrome. Life After High School It is important for individuals with Down syndrome ... most important transitions of all - the move from high school to life after high school. Read More Transition & ...

  11. Transitional Care

    ERIC Educational Resources Information Center

    Naylor, Mary; Keating, Stacen A.

    2008-01-01

    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…

  12. Transition metals

    PubMed Central

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

    2013-01-01

    Transition metals such as Iron (Fe) and Copper (Cu) are essential for plant cell development. At the same time, due their capability to generate hydroxyl radicals they can be potentially toxic to plant metabolism. Recent works on hydroxyl-radical activation of ion transporters suggest that hydroxyl radicals generated by transition metals could play an important role in plant growth and adaptation to imbalanced environments. In this mini-review, the relation between transition metals uptake and utilization and oxidative stress-activated ion transport in plant cells is analyzed, and a new model depicting both apoplastic and cytosolic mode of ROS signaling to plasma membrane transporters is suggested. PMID:23333964

  13. Two-electron transfer and ionization mechanism in 80-keV/u Ne8 + on He collisions

    NASA Astrophysics Data System (ADS)

    Zhang, R. T.; Feng, W. T.; Zhu, X. L.; Zhang, S. F.; Guo, D. L.; Gao, Y.; Qian, D. B.; Xu, S.; Yan, S. C.; Zhang, P.; Huang, Z. K.; Wang, H. B.; Hai, B.; Zhao, D. M.; Ma, X.

    2016-03-01

    Autoionization decay from doubly excited states of Ne6 +[1 s23 l n l (n =3 ,4 ,5 )] (symmetric configurations) as well as the Coster-Kronig transition from doubly excited states of Ne6 +[1 s22 p n l (n ⩾7 ) ] (asymmetric configurations) are observed in the transfer ionization reaction channel of 80 keV/u Ne8 +-He collisions. It has been predicted that the formation of symmetric configurations results from uncorrelated double-electron capture processes [Z. Chen and C. D. Lin, Phys. Rev. A 48, 1298 (1993), 10.1103/PhysRevA.48.1298], and the formation of asymmetric configurations probably results from correlated double-electron capture caused by the dynamical electron-correlation effects which are attributed to small internuclear distances. However, previous experimental measurements were not able to obtain information about the dependence on internuclear distance which can be reflected in the transversal recoil-ion momentum. In this work, we measure the recoil-ion momentum in coincidence with the ejected electron velocity and find that the observed transverse recoil-ion momentum is smaller for the formation of symmetric Ne6 +[1 s23 l n l (n =3 ,4 ,5 ) ] states than the formation of asymmetric Ne6 +[1 s22 p n l (n ⩾7 ) ] states. Since large momentum transfer occurs for small internuclear distances (strong electron-electron interactions) and small momentum transfer occurs for large internuclear distances (weak electron-electron interactions), the results indicate that dynamical electron correlation is important for the formation of the asymmetric states.

  14. Improved spectrum simulation for validating SEM-EDS analysis

    NASA Astrophysics Data System (ADS)

    Statham, P.; Penman, C.; Duncumb, P.

    2016-02-01

    X-ray microanalysis by SEM-EDS requires corrections for the many physical processes that affect emitted intensity for elements present in the material. These corrections will only be accurate provided a number of conditions are satisfied and it is essential that the correct elements are identified. As analysis is pushed to achieve results on smaller features and more challenging samples it becomes increasingly difficult to determine if all conditions are upheld and whether the analysis results are valid. If a theoretical simulated spectrum based on the measured analysis result is compared with the measured spectrum, any marked differences will indicate problems with the analysis and can prevent serious mistakes in interpretation. To achieve the necessary accuracy a previous theoretical model has been enhanced to incorporate new line intensity measurements, differential absorption and excitation of emission lines, including the effect of Coster-Kronig transitions and an improved treatment of bremsstrahlung for compounds. The efficiency characteristic has been measured for a large area SDD detector and data acquired from an extensive set of standard materials at both 5 kV and 20 kV. The parameterized model has been adjusted to fit measured characteristic intensities and both background shape and intensity at the same beam current. Examples are given to demonstrate how an overlay of an accurate theoretical simulation can expose some non-obvious mistakes and provide some expert guidance towards a valid analysis result. A new formula for calculating the effective mean atomic number for compounds has also been derived that is appropriate and should help improve accuracy in techniques that calculate the bremsstrahlung or use a bremsstrahlung measurement for calibration.

  15. Measurements of L-Auger spectra of Pu, Am, Cf, and Fm and comparison with theory

    SciTech Connect

    Haynes, S.K.; Freedman, M.S.; Porter, F.T.

    1984-07-01

    The L-Auger spectra of 2 /sub 94//sup 39/Pu (64 lines), /sub 100//sup 254/Fm (54 lines), 2 /sub 95//sup 41/Am (41 LMM lines only), and 2 /sub 98//sup 50/Cf (35 LMM lines only) were scanned over the range 6--19 keV at high resolution (10/sup -3/< or =..delta..E/E< or =2 x 10/sup -3/) in the Argonne National Laboratory iron-free double toroidal spectrometer using thin (< or =1 ..mu..g/cm/sup 2/) isotopically separated radioactive sources. The observed energies of lines or line complexes agreed with Larkins's semiempirical predictions within the combined (theoretical plus experimental) standard deviations (1 s.d. = 10--20 eV in 10--20 keV) in 78% of the comparisons, and 19% were within 1--2 s.d. The measured intensities (relative to L/sub 3/M/sub 4/M/sub 5/) for Pu were compared to nonrelativistic predictions of McGuire for Z = 90, with the relativistic predictions of Chen et al. for Z = 94, and with a mixed system using Chen et al. for Coster-Kronig and McGuire for L-Auger transitions. Fm intensities (and Am and Cf qualitatively) could be compared only to relativistic theories. Relativistic predictions are clearly better for Pu, but are not, in general, satisfactory for either Pu or Fm; for all Pu and Fm lines, taken together, 58% are within 1 s.d., 30% in the range 1--2 s.d., and 12% greater than 2 s.d., with the relativistic predictions generally low except for the L/sub 3/MM band, which is in acceptable agreement.

  16. Metric transition

    NASA Technical Reports Server (NTRS)

    1992-01-01

    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.

  17. Muted Transitions

    ERIC Educational Resources Information Center

    Kofoed, Jette

    2008-01-01

    This analysis concentrates on the case of a child, Jenny. The paper suggests that the concept of liminality may hold the key to an understanding of muted subject positions like the one assumed by Jenny in a school class. Liminality is proposed as a way of conceptualizing transitions where the subject in question transgresses established rules and…

  18. [Humanitarian transition].

    PubMed

    Mattei, Jean-François; Troit, Virginie

    2016-02-01

    In two centuries, modern humanitarian action has experienced several fractures often linked to crises. Although its professionalism and intervention force remain indisputable, it faces, since the 2000s, a new context that limits its ability to act and confronts it with new dilemmas, even though it must deal with needs for aid of unprecedented scale. These difficulties reveal a humanitarian transition period that was not anticipated. This transition period reflects the change from a dominant paradigm of North-South solidarity of Western origin to a much more complex model. This article provides a summary of the current mutations that are dominated by the States' assertion of sovereignty. Among the possible solutions, it argues for an ethical approach and a better integration of the research carried out in the Global South, prerequisites for building a true partnership and placing the victims at the heart of the operations which involve them. PMID:26936180

  19. Eliminating Transitions

    ERIC Educational Resources Information Center

    Gallick, Barb; Lee, Lisa

    2010-01-01

    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…

  20. Assessment of a self-consistent theoretical data base for L X-Ray relative intensities in proton-induced X-Ray emission analysis

    NASA Astrophysics Data System (ADS)

    Campbell, J. L.

    1988-06-01

    Recent Dirac-Hartree-Slater and Dirac-Hartree-Fock calculations of ionization cross-sections, fluorescence and Coster-Kronig yields and X-ray emission rates offer a "self-consistent" theoretical data base for relative intensities of proton-induced L X-rays. Interpolation schemes for use with tables of these quantities are described. Theoretical intensity ratios for major line groups agree with compiled experimental data to within a few percent, justifying use of the data base in PIXE.

  1. Dynamo Transition

    SciTech Connect

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

    2010-11-23

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

  2. Transitions: A Personal Perspective.

    ERIC Educational Resources Information Center

    Wood, Ann Stace

    1995-01-01

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

  3. PyTransit: Transit light curve modeling

    NASA Astrophysics Data System (ADS)

    Parviainen, Hannu

    2015-05-01

    PyTransit implements optimized versions of the Giménez and Mandel & Agol transit models for exoplanet transit light-curves. The two models are implemented natively in Fortran with OpenMP parallelization, and are accessed by an object-oriented python interface. PyTransit facilitates the analysis of photometric time series of exoplanet transits consisting of hundreds of thousands of data points, and of multipassband transit light curves from spectrophotometric observations. It offers efficient model evaluation for multicolour observations and transmission spectroscopy, built-in supersampling to account for extended exposure times, and routines to calculate the projected planet-to-star distance for circular and eccentric orbits, transit durations, and more.

  4. Tips for Transition

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  5. Gas turbine combustor transition

    DOEpatents

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

    1999-05-25

    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.

  6. Gas turbine combustor transition

    DOEpatents

    Coslow, Billy Joe; Whidden, Graydon Lane

    1999-01-01

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

  7. Conceptualizing Transitions to Adulthood

    ERIC Educational Resources Information Center

    Wyn, Johanna

    2014-01-01

    This chapter provides an overview of theories of the transition to young adulthood. It sets out the argument for conceptual renewal and discusses some implications of new patterns of transition for adult education.

  8. Transition to Adulthood

    MedlinePlus

    ... ones occurs when we get ready to leave high school and go out in the world as young ... the world of adulthood. Transition planning begins during high school at the latest. IDEA requires that transition planning ...

  9. Transition in Turbines

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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.

  10. Transitivity of Preferences

    ERIC Educational Resources Information Center

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

    2011-01-01

    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

  11. Transitivity of Preferences

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  12. Deforming geometric transitions

    NASA Astrophysics Data System (ADS)

    Rossi, Michele

    2015-04-01

    After a quick review of the wild structure of the complex moduli space of Calabi-Yau 3-folds and the role of geometric transitions in this context (the Calabi-Yau web) the concept of deformation equivalence for geometric transitions is introduced to understand the arrows of the Gross-Reid Calabi-Yau web as deformation-equivalence classes of geometric transitions. Then the focus will be on some results and suitable examples to understand under which conditions it is possible to get simple geometric transitions, which are almost the only well-understood geometric transitions both in mathematics and in physics.

  13. Modeling the transition region

    NASA Technical Reports Server (NTRS)

    Singer, Bart A.

    1993-01-01

    The current status of transition-region models is reviewed in this report. To understand modeling problems, various flow features that influence the transition process are discussed first. Then an overview of the different approaches to transition-region modeling is given. This is followed by a detailed discussion of turbulence models and the specific modifications that are needed to predict flows undergoing laminar-turbulent transition. Methods for determining the usefulness of the models are presented, and an outlook for the future of transition-region modeling is suggested.

  14. Gifts from Exoplanetary Transits

    NASA Astrophysics Data System (ADS)

    Narita, Norio

    2009-08-01

    The discovery of transiting extrasolar planets has enabled us to do a number of interesting studies. Transit photometry reveals the radius and the orbital inclination of transiting planets, which allows us to learn the true mass and density of the respective planets by the combined information from radial velocity (RV) measurements. In addition, follow-up observations of transiting planets, looking at such things as secondary eclipses, transit timing variations, transmission spectroscopy, and the Rossiter-McLaughlin effect, provide us information about their dayside temperatures, unseen bodies in systems, planetary atmospheres, and the 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.

  15. Reconstructing Regulatory Network Transitions

    PubMed Central

    Petricka, Jalean J.; Benfey, Philip N.

    2011-01-01

    Cellular responses often involve a transition of cells from one state to another. A transition from a stem cell to differentiated cell state, for example, may occur in response to gene expression changes induced by a transcription factor, or signaling cascades triggered by a hormone or pathogen. Regulatory networks are thought to control such cellular transitions. Thus, many researchers are interested in reconstructing regulatory networks, not only to gain a deeper understanding of cellular transitions, but also with the aim of using networks to predict and potentially manipulate cellular transitions and outcomes. In this review, we highlight approaches to the reconstruction of regulatory networks underlying cellular transitions, with special attention to transcriptional regulatory networks. We describe recent regulatory network reconstructions in a variety of organisms and discuss the success they share in identifying new regulatory components as well as shared relationships and phenotypic outcomes. PMID:21632251

  16. Transitive and Pseudo-Transitive Inferences

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  17. Transition to Old Age (Transition to Retirement).

    ERIC Educational Resources Information Center

    Bergman, Simon

    Several conceptualizations and definitions of retirement have been proposed. One of them--the three-stage transition process--can be illustrated from studies in Israel: (1) leaving the old role; (2) going through the act of formal separation; and (3) adjusting to the new situation and role. Today's higher rate of survival into later years means…

  18. Transition to Living.

    ERIC Educational Resources Information Center

    Repetto, Jeanne B.

    2003-01-01

    Discussion of transition for students with disabilities emphasizes transition skills needed for life beyond work. The importance of assisting students in planning for their life roles as workers, family members, friends, consumers, and community members is discussed. Suggestions are offered to better prepare students for all their life roles by…

  19. Good Transitions = Great Starts!

    ERIC Educational Resources Information Center

    Our Children: The National PTA Magazine, 2012

    2012-01-01

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

  20. Issues in Transition.

    ERIC Educational Resources Information Center

    McNair, Jeff, Ed.; Kronick, Nancy, Ed.

    Six papers address issues in the transition of students with disabilities into the adult world of work. In "Workplace Support," Jeff McNair defines "support," differentiates types of support, and considers various foci of intervention. The second paper titled, "Cross-Cultural Transition: An Exigent Topic for Study" by Nancy Kronick, reviews…

  1. Transitional Employment Programs.

    ERIC Educational Resources Information Center

    Dulle, Paul J.; And Others

    The paper examines the need and implementation of transitional employment programs for handicapped youth. Effects on the handicapped of future automation are considered along with the need for school-business cooperation to prepare for the future. The importance of initial success in any innovation is noted. A Chicago transitional employment…

  2. Matter in transition

    NASA Astrophysics Data System (ADS)

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-04-01

    We explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, where a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU( N) require Weierstrass models that cannot be realized from the standard SU( N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.

  3. Transitions in Spousal Caregiving.

    ERIC Educational Resources Information Center

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

    2003-01-01

    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…

  4. Seamless Transition for All

    ERIC Educational Resources Information Center

    Test, David W.

    2008-01-01

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

  5. Seamless Transition for All

    ERIC Educational Resources Information Center

    Test, David W.

    2008-01-01

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

  6. School Transition Bibliography.

    ERIC Educational Resources Information Center

    Pautler, Albert

    This bibliography on school transition includes 240 entries of books, journal articles, papers, reports, bibliographies, and dissertations. These entries deal with transitions of the following populations: adult learners, youth, Plains Indian women, high school students, people with learning disabilities, disadvantaged youth, high school…

  7. Transitioning between Clerkship Directors

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  8. A Posteriori Transit Probabilities

    NASA Astrophysics Data System (ADS)

    Stevens, Daniel J.; Gaudi, B. Scott

    2013-08-01

    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 ~Rlowast/a, given the primary radius Rlowast 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 Mc sin 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, dΓ/dMcvpropMcα, for integer values -3 <= α <= 3. We show that for low transit probabilities, these probabilities reduce to a constant multiplicative factor fα of the corresponding prior transit probability, where fα in general depends on α and an assumed upper limit on the true mass. The prior and posterior probabilities are equal for α = -1. The posterior transit probability is ~1.5 times larger than the prior for α = -3 and is ~4/π times larger for α = -2, but is less than the prior for α>=0, and can be arbitrarily small for α > 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 (3 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.

  9. Predictability of critical transitions

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaozhu; Kuehn, Christian; Hallerberg, Sarah

    2015-11-01

    Critical transitions in multistable systems have been discussed as models for a variety of phenomena ranging from the extinctions of species to socioeconomic changes and climate transitions between ice ages and warm ages. From bifurcation theory we can expect certain critical transitions to be preceded by a decreased recovery from external perturbations. The consequences of this critical slowing down have been observed as an increase in variance and autocorrelation prior to the transition. However, especially in the presence of noise, it is not clear whether these changes in observation variables are statistically relevant such that they could be used as indicators for critical transitions. In this contribution we investigate the predictability of critical transitions in conceptual models. We study the quadratic integrate-and-fire model and the van der Pol model under the influence of external noise. We focus especially on the statistical analysis of the success of predictions and the overall predictability of the system. The performance of different indicator variables turns out to be dependent on the specific model under study and the conditions of accessing it. Furthermore, we study the influence of the magnitude of transitions on the predictive performance.

  10. Predictability of critical transitions.

    PubMed

    Zhang, Xiaozhu; Kuehn, Christian; Hallerberg, Sarah

    2015-11-01

    Critical transitions in multistable systems have been discussed as models for a variety of phenomena ranging from the extinctions of species to socioeconomic changes and climate transitions between ice ages and warm ages. From bifurcation theory we can expect certain critical transitions to be preceded by a decreased recovery from external perturbations. The consequences of this critical slowing down have been observed as an increase in variance and autocorrelation prior to the transition. However, especially in the presence of noise, it is not clear whether these changes in observation variables are statistically relevant such that they could be used as indicators for critical transitions. In this contribution we investigate the predictability of critical transitions in conceptual models. We study the quadratic integrate-and-fire model and the van der Pol model under the influence of external noise. We focus especially on the statistical analysis of the success of predictions and the overall predictability of the system. The performance of different indicator variables turns out to be dependent on the specific model under study and the conditions of accessing it. Furthermore, we study the influence of the magnitude of transitions on the predictive performance. PMID:26651760

  11. Child Custody in Transition.

    ERIC Educational Resources Information Center

    Franklin, Robin L.; Hibbs, B.

    1980-01-01

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

  12. The Heliosphere in Transition

    NASA Astrophysics Data System (ADS)

    Kasper, Justin

    2015-04-01

    The heliosphere consists of the connective tissue of particles, fields and photons that mediate our interaction with the Sun and with interstellar space. Exploration of the heliosphere yields clues to the nature of environments we cannot reach ourselves, illuminating the composition of the solar interior, or the acceleration of cosmic rays in the galaxy. The heliosphere is also a laboratory for us to understand the fundamental physics of magnetized plasma, from heating and instabilities to coupling with neutral gas and dust. This talk will review some of the most exciting recent results in the heliosphere with a focus on transitions: what we can learn by exploring transitions within the heliosphere, how the heliosphere is responding to the long term transition in solar activity, and how our very view of the heliosphere is in transition with upcoming missions such as Solar Probe Plus, Solar Orbiter and IMAP.

  13. Oligocyclopentadienyl transition metal complexes

    SciTech Connect

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

    2002-01-18

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

  14. Alternative fuel transit buses

    SciTech Connect

    Motta, R.; Norton, P.; Kelly, K.

    1996-10-01

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

  15. Melting of Transition Metals

    SciTech Connect

    Ross, M; Japel, S; Boehler, R

    2005-04-11

    We review the transition melting studies carried out at Mainz, and describe a recently developed model used to explain that the relatively low melting slopes are due to the partially filled d-bands, and the persistence of the pressure induced s-d transition. The basic tenets of the model have now been reconfirmed by new measurements for Cu and Ni. The measurements show that Cu which has a filled 3d-band, has a melt slope that is about 2.5 greater than its neighbor Ni. In the case of Mo, the apparent discrepancy of DAC melting measurements with shock melting can be explained by accounting for the change in melt slope due to the bcc-cp transition observed in the shock studies. The Fe melt curve is revisited. The possible relevance of the Jahn-Teller effect and recently observed transition metal melts with Icosahedral Short-Range Order (ISRO) is discussed.

  16. Superconductivity in transition metals.

    PubMed

    Slocombe, Daniel R; Kuznetsov, Vladimir L; Grochala, Wojciech; Williams, Robert J P; Edwards, Peter P

    2015-03-13

    A qualitative account of the occurrence and magnitude of superconductivity in the transition metals is presented, with a primary emphasis on elements of the first row. Correlations of the important parameters of the Bardeen-Cooper-Schrieffer theory of superconductivity are highlighted with respect to the number of d-shell electrons per atom of the transition elements. The relation between the systematics of superconductivity in the transition metals and the periodic table high-lights the importance of short-range or chemical bonding on the remarkable natural phenomenon of superconductivity in the chemical elements. A relationship between superconductivity and lattice instability appears naturally as a balance and competition between localized covalent bonding and so-called broken covalency, which favours d-electron delocalization and superconductivity. In this manner, the systematics of superconductivity and various other physical properties of the transition elements are related and unified. PMID:25666075

  17. Matter in transition

    DOE PAGESBeta

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-04-13

    In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, wheremore » a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.« less

  18. Single, double, and triple Auger decay of the Xe 4p core-hole states

    SciTech Connect

    Hikosaka, Y.; Kaneyasu, T.; Shigemasa, E.; Lablanquie, P.; Penent, F.; Eland, J. H. D.; Aoto, T.; Ito, K.

    2007-09-15

    Auger decay of Xe{sup +} states arising from 4p ionization has been studied with a very efficient multielectron coincidence method. Coster-Kronig decay from Xe{sup +} 4p{sup -1} and the subsequent decay into Xe{sup 3+} states with three valence holes are identified. Formation of Xe{sup 4+} is also observed as quadruple coincidences between a 4p photoelectron and three Auger electrons. The relative probabilities of individual multi-ionization processes are determined from the coincidence yields.

  19. Si(Li) detector lineshapes for PIXE analysis and improvement of the PIXE database

    NASA Astrophysics Data System (ADS)

    Campbell, J. L.

    1987-03-01

    The various mechanisms giving rise to low-energy peak tailing in Si(Li) X-ray detectors are discussed. The Hypermet lineshape function is shown to be satisfactory in the energy range 4-15 keV. Stringent tests of the X-ray relative intensity database used in PIXE, performed with detectors of accurately known lineshape, lend it strong support. Current measurements of the L subshell fluorescence and Coster-Kronig yields indicate that the latter may be systematically lower than theory.

  20. Venus Transit 2004

    NASA Astrophysics Data System (ADS)

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

    2002-09-01

    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.

  1. Care transitions: integrating transition theory and complexity science concepts.

    PubMed

    Geary, Carol R; Schumacher, Karen L

    2012-01-01

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

  2. Examining hydrogen transitions.

    SciTech Connect

    Plotkin, S. E.; Energy Systems

    2007-03-01

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

  3. RTGs on Transit

    NASA Astrophysics Data System (ADS)

    Dassoulas, John; McNutt, Ralph L.

    2007-01-01

    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.

  4. Noise and Phase Transitions

    NASA Astrophysics Data System (ADS)

    Chen, Zhi; Yu, Clare C.

    2006-03-01

    Noise is present in many physical systems and is often viewed as a nuisance. Yet it can also be a probe of microscopic fluctuations. There have been indications recently that the noise in the resistivity increases in the vicinity of the metal-insulator transition. But what are the characteristics of the noise associated with well-understood first and second order phase transitions? It is well known that critical fluctuations are associated with second order phase transitions, but do these fluctuations lead to enhanced noise? We have addressed these questions using Monte Carlo simulations to study the noise in the 2D Ising model which undergoes a second order phase transition, and in the 5-state Potts model which undergoes a first order phase transition. We monitor these systems as the temperature drops below the critical temperature. At each temperature, after equilibration is established, we obtain the time series of quantities characterizing the properties of the system, i.e., the energy and magnetization per site. We apply different methods, such as the noise power spectrum, the Detrended Fluctuation Analysis (DFA) and the second spectrum of the noise, to analyze the fluctuations in these quantities.

  5. Perspective: The glass transition.

    PubMed

    Biroli, Giulio; Garrahan, Juan P

    2013-03-28

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

  6. Phase transitions in nuclear physics

    SciTech Connect

    Moretto, L.G.; Phair, L.; Wozniak, G.J.

    1997-08-01

    A critical overview of the low energy phase transitions in nuclei is presented with particular attention to the 2nd (1st) order pairing phase transitions, and to the 1st order liquid-vapor phase transition. The role of fluctuations in washing out these transitions is discussed and illustrated with examples. A robust indicator of phase coexistence in multifragmentation is presented.

  7. Boundary-layer transition

    NASA Astrophysics Data System (ADS)

    Matthews, R. K.

    The prediction of the boundary layer transition Reynolds number for the design of hypersonic vehicles is considered. The boundary layer state (laminar or turbulent) that approaches the vehicle control surfaces can significantly affect the control surface effectiveness. In addition, the heating rates associated with turbulent boundary layers are often ten times higher than those of laminar boundary layers. Unfortunately, the methodology to predict transition has eluded the aerodynamicist for over three decades, and there are still many unanswered questions. Many parameters that affect transition are considered and numerous references for those who are interested in specializing in this topic are provided. It is emphasized that during wind tunnel testing it is very important to know the boundary layer state. Typically, heat transfer distributions can provide this information; however, it is often necessary to artificially trip the flow to induce a turbulent boundary layer. The methodology of using trip spheres is discussed, and illustrative data are presented.

  8. Transition and laminar instability

    NASA Technical Reports Server (NTRS)

    Mack, L. M.

    1977-01-01

    The linear stability theory was applied to the problem of boundary layer transition in incompressible flow. The theory was put into a form suitable for three-dimensional boundary layers; both the temporal and spatial theories were examined; and a generalized Gaster relation for three-dimensional boundary layers was derived. Numerical examples include the stability characteristics of Falkner-Skan boundary layers, the accuracy of the two-dimensional Gaster relation for these boundary layers, and the magnitude and direction of the group velocity for oblique waves in the Blasius boundary layer. Available experiments which bear on the validity of stability theory and its relation to transition are reviewed and the stability theory is applied to transition prediction. The amplitude method is described in which the wide band disturbance amplitude in the boundary layer is estimated from stability theory and an interaction relation for the initial amplitude density of the most unstable frequency.

  9. China's urban transition.

    PubMed

    Pannell, C

    1995-01-01

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

  10. Network observability transitions.

    PubMed

    Yang, Yang; Wang, Jianhui; Motter, Adilson E

    2012-12-21

    In the modeling, monitoring, and control of complex networks, a fundamental problem concerns the comprehensive determination of the state of the system from limited measurements. Using power grids as example networks, we show that this problem leads to a new type of percolation transition, here termed a network observability transition, which we solve analytically for the configuration model. We also demonstrate a dual role of the network's community structure, which both facilitates optimal measurement placement and renders the networks substantially more sensitive to "observability attacks." Aside from their immediate implications for the development of smart grids, these results provide insights into decentralized biological, social, and technological networks. PMID:23368505

  11. Using Community Transition Teams To Improve Transition Services. PRO-ED Series on Transition.

    ERIC Educational Resources Information Center

    Blalock, Ginger; Benz, Michael R.

    Part of a series designed to provide practical resources for transition personnel on a variety of topics critical to the process of preparing individuals with disabilities for adulthood, this guide focuses on using transition teams to improve transition services. Chapter 1, "The Roles of Community Transition Teams," discusses the benefits of…

  12. Tips for Transition

    ERIC Educational Resources Information Center

    Kellems, Ryan O.; Morningstar, Mary E.

    2010-01-01

    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…

  13. Variational transition state theory

    SciTech Connect

    Truhlar, D.G.

    1993-12-01

    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.

  14. Youth Policy in Transition.

    ERIC Educational Resources Information Center

    Timpane, Michael; And Others

    A study team was commissioned to critically review three independent reports on youth and schooling: "Youth: Transition to Adulthood"; "The Education of Adolescents"; and "The Reform of Secondary Education." The study team examined the reports in light of the most recent available social science evidence. The three reports, presenting similar…

  15. Transit-bus maintenance

    SciTech Connect

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

    1987-01-01

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

  16. Is Mass Transit Possible?

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1975

    1975-01-01

    Mass transit is possible in the United States, but only if the form it takes offers americans the quality of ride--cheap, private and rapid--they now have in the automobile. If these criteria are not achieved, Americans will continue to drive. (BT)

  17. A Transiting Jupiter Analog

    NASA Astrophysics Data System (ADS)

    Kipping, D. M.; Torres, G.; Henze, C.; Teachey, A.; Isaacson, H.; Petigura, E.; Marcy, G. W.; Buchhave, L. A.; Chen, J.; Bryson, S. T.; Sandford, E.

    2016-04-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of (0.91+/- 0.02) {R}{{J}}, a low orbital eccentricity ({0.06}-0.04+0.10), and an equilibrium temperature of (131+/- 3) K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric coverage, we are able to uniquely and precisely measure the orbital period of this post snow-line planet (1071.2323 ± 0.0006d), paving the way for follow-up of this K = 11.8 mag target.

  18. Immigration and Adult Transitions

    ERIC Educational Resources Information Center

    Rumbaut, Ruben G.; Komaie, Golnaz

    2010-01-01

    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…

  19. Transition at hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Morkovin, Mark V.

    1987-01-01

    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.

  20. String mediated phase transitions

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  1. Modeling of transitional flows

    NASA Technical Reports Server (NTRS)

    Lund, Thomas S.

    1988-01-01

    An effort directed at developing improved transitional models was initiated. The focus of this work was concentrated on the critical assessment of a popular existing transitional model developed by McDonald and Fish in 1972. The objective of this effort was to identify the shortcomings of the McDonald-Fish model and to use the insights gained to suggest modifications or alterations of the basic model. In order to evaluate the transitional model, a compressible boundary layer code was required. Accordingly, a two-dimensional compressible boundary layer code was developed. The program was based on a three-point fully implicit finite difference algorithm where the equations were solved in an uncoupled manner with second order extrapolation used to evaluate the non-linear coefficients. Iteration was offered as an option if the extrapolation error could not be tolerated. The differencing scheme was arranged to be second order in both spatial directions on an arbitrarily stretched mesh. A variety of boundary condition options were implemented including specification of an external pressure gradient, specification of a wall temperature distribution, and specification of an external temperature distribution. Overall the results of the initial phase of this work indicate that the McDonald-Fish model does a poor job at predicting the details of the turbulent flow structure during the transition region.

  2. Singing Smoothes Classroom Transitions

    ERIC Educational Resources Information Center

    Mathews, Sarah E.

    2012-01-01

    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…

  3. Families in Transition.

    ERIC Educational Resources Information Center

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

    1987-01-01

    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)…

  4. A Survey Transition Course

    ERIC Educational Resources Information Center

    Johnston, William; McAllister, Alex M.

    2012-01-01

    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…

  5. A Survey Transition Course

    ERIC Educational Resources Information Center

    Johnston, William; McAllister, Alex M.

    2012-01-01

    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

  6. Learning for Life Transitions

    ERIC Educational Resources Information Center

    Varmecky, Jane Hyde

    2012-01-01

    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…

  7. Singing Smoothes Classroom Transitions

    ERIC Educational Resources Information Center

    Mathews, Sarah E.

    2012-01-01

    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

  8. Transit of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Doyle, Laurance R.

    1998-01-01

    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.

  9. Alternative fuel transit buses: The Pierce Transit Success Story

    SciTech Connect

    1996-10-01

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

  10. Assessment for Transitions Planning. PRO-ED Series on Transition.

    ERIC Educational Resources Information Center

    Clark, Gary M.

    Part of a series designed to provide practical resources for transition personnel on a variety of topics essential to the process of preparing individuals with disabilities for adulthood, this guide focuses on assessment for transition planning. Chapter 1, "Transitions Assessment: What Do We Need To Know about Students and Why?," discusses the

  11. Transitions: exploring the frontier.

    PubMed

    Corless, Inge B

    End-of-life experiences go by various terms, including near-death experiences (NDEs), death bed visions, death bed phenomena, death bed coincidences, and nearing death awareness. Death bed escorts is the term applied to the vision of deceased family members or friends who inform the dying person that they will be accompanied in the transition from life. In this article, I examine the subject of NDEs and death bed escorts, starting with the rich body of work provided by Robert and Beatrice Kastenbaum. A subject of some interest to Robert Kastenbaum, he explored this frontier in his many writings on dying, death, and bereavement. Ever the pioneer and having made the ultimate transition, he may yet be exploring new frontiers. PMID:25351590

  12. Collapse transition in proteins

    PubMed Central

    Ziv, Guy; Thirumalai, D.

    2008-01-01

    The coil–globule transition, a tenet of the physics of polymers, has been identified in recent years as an important unresolved aspect of the initial stages of the folding of proteins. We describe the basics of the collapse transition, starting with homopolymers and continuing with proteins. Studies of denatured-state collapse under equilibrium are then presented. An emphasis is placed on single-molecule fluorescence experiments, which are particularly useful for measuring properties of the denatured state even under conditions of coexistence with the folded state. Attempts to understand the dynamics of collapse, both theoretically and experimentally, are then described. Only an upper limit for the rate of collapse has been obtained so far. Improvements in experimental and theoretical methodology are likely to continue to push our understanding of the importance of the denatured-state thermodynamics and dynamics for protein folding in the coming years. PMID:19081910

  13. Collapse transition in proteins.

    PubMed

    Ziv, Guy; Thirumalai, D; Haran, Gilad

    2009-01-01

    The coil-globule transition, a tenet of the physics of polymers, has been identified in recent years as an important unresolved aspect of the initial stages of the folding of proteins. We describe the basics of the collapse transition, starting with homopolymers and continuing with proteins. Studies of denatured-state collapse under equilibrium are then presented. An emphasis is placed on single-molecule fluorescence experiments, which are particularly useful for measuring properties of the denatured state even under conditions of coexistence with the folded state. Attempts to understand the dynamics of collapse, both theoretically and experimentally, are then described. Only an upper limit for the rate of collapse has been obtained so far. Improvements in experimental and theoretical methodology are likely to continue to push our understanding of the importance of the denatured-state thermodynamics and dynamics for protein folding in the coming years. PMID:19081910

  14. Stimulated coherent transition radiation

    SciTech Connect

    Hung-chi Lihn

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed.

  15. Embolus in transit.

    PubMed

    Dejecacion, Jodie; Veselka, Deanne; Ragain, Michael; Jenkins, Leigh Ann; Meyerrose, Gary

    2003-11-01

    A patient who presented with recurrent syncopal episodes was discovered to have a right-sided heart mass, which was revealed as an embolus in transit resulting in a lethal pulmonary embolic event. The initial focus of etiology on tumor rather than thrombus was misleading. A higher index of suspicion of thrombus in right heart mass may help future patients receive more directed therapy. PMID:14632370

  16. NASA metric transition plan

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA science publications have used the metric system of measurement since 1970. Although NASA has maintained a metric use policy since 1979, practical constraints have restricted actual use of metric units. In 1988, an amendment to the Metric Conversion Act of 1975 required the Federal Government to adopt the metric system except where impractical. In response to Public Law 100-418 and Executive Order 12770, NASA revised its metric use policy and developed this Metric Transition Plan. NASA's goal is to use the metric system for program development and functional support activities to the greatest practical extent by the end of 1995. The introduction of the metric system into new flight programs will determine the pace of the metric transition. Transition of institutional capabilities and support functions will be phased to enable use of the metric system in flight program development and operations. Externally oriented elements of this plan will introduce and actively support use of the metric system in education, public information, and small business programs. The plan also establishes a procedure for evaluating and approving waivers and exceptions to the required use of the metric system for new programs. Coordination with other Federal agencies and departments (through the Interagency Council on Metric Policy) and industry (directly and through professional societies and interest groups) will identify sources of external support and minimize duplication of effort.

  17. NASA metric transition plan

    NASA Astrophysics Data System (ADS)

    NASA science publications have used the metric system of measurement since 1970. Although NASA has maintained a metric use policy since 1979, practical constraints have restricted actual use of metric units. In 1988, an amendment to the Metric Conversion Act of 1975 required the Federal Government to adopt the metric system except where impractical. In response to Public Law 100-418 and Executive Order 12770, NASA revised its metric use policy and developed this Metric Transition Plan. NASA's goal is to use the metric system for program development and functional support activities to the greatest practical extent by the end of 1995. The introduction of the metric system into new flight programs will determine the pace of the metric transition. Transition of institutional capabilities and support functions will be phased to enable use of the metric system in flight program development and operations. Externally oriented elements of this plan will introduce and actively support use of the metric system in education, public information, and small business programs. The plan also establishes a procedure for evaluating and approving waivers and exceptions to the required use of the metric system for new programs. Coordination with other Federal agencies and departments (through the Interagency Council on Metric Policy) and industry (directly and through professional societies and interest groups) will identify sources of external support and minimize duplication of effort.

  18. The Myths of Mass Transit.

    ERIC Educational Resources Information Center

    Burke, Catherine G.

    1982-01-01

    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)

  19. Navy Navigation Satellite System (TRANSIT)

    NASA Astrophysics Data System (ADS)

    Sentman, O. L.

    The Navy Navigation Satellite System (TRANSIT) has provided 100 percent system reliability since being declared operational October 11, 1968. TRANSIT continues to carry out its function of precise, reliable, all weather navigation for the United States Navy and nearly 80,000 worldwide commercial users. TRANSIT's utility has been expanded to provide precise positioning information to those in the fields of geodesy and Doppler surveying. While TRANSIT's history is illustrious, its life is limited. The transition from TRANSIT as the Navy's satellite navigation system to NAVSTAR GPS is planned for the 1990's, with the result that TRANSIT is now scheduled for phase out by the United States Navy in 1994. This paper (essentially an update of reference (1) will show the current status and plans for TRANSIT, following a brief historical overview.

  20. Youths Transitioning as Adult Learners

    ERIC Educational Resources Information Center

    Davis, C. Amelia

    2014-01-01

    This chapter considers how transitions to adulthood have been historically represented and presents alternative ways of thinking about transitions to adulthood through the context of adult basic education programs.

  1. The transition to agricultural sustainability

    PubMed Central

    Ruttan, Vernon W.

    1999-01-01

    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

  2. Visual Analytics Technology Transition Progress

    SciTech Connect

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

    2009-09-23

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

  3. Reconstructing Transition Knowledge in Taiwan

    ERIC Educational Resources Information Center

    Cheng, Chen-chen

    2012-01-01

    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…

  4. Transition "Movement" into the Curriculum

    ERIC Educational Resources Information Center

    Pica, Rae

    2010-01-01

    Teachers usually do not give as much thought to transitions as they do to other facets of the early childhood curriculum. As a result, transitions often lead to chaos and wasted time. But this doesn't have to be the case. If teachers "plan" transitions, as they do other daily components of the curriculum, they can avoid chaos and ensure that…

  5. Secondary Special Educators' Transition Involvement

    ERIC Educational Resources Information Center

    Li, Jen-Yi; Bassett, Diane S.; Hutchinson, Susan R.

    2009-01-01

    Background: Different roles and responsibilities are required of school professionals to facilitate students' successful transition from school to post-school lives. Special educators' involvement in transition services is essential for better post-school outcomes for students with disability. Method: The Transition Involvement Survey with five…

  6. Community Transition Teams: Enhancing Student Involvement in Transition through Community Transition Teams.

    ERIC Educational Resources Information Center

    Benz, Michael R.; Blalock, Ginger

    1999-01-01

    Describes the role of community transition teams as a mechanism for developing school-family-community partnerships and enhancing student involvement in transition. Discusses challenges and lessons for building and maintaining effective partnerships over time. (Author)

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

    SciTech Connect

    Chandler, K.; Eudy, L.

    2007-03-01

    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.

  8. Electromagnetic transitions in hypernuclei

    SciTech Connect

    Chrien, R.E.

    1986-01-01

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

  9. Transition Metal Switchable Mirror

    ScienceCinema

    None

    2013-05-29

    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

  10. Transition Metal Switchable Mirror

    ScienceCinema

    None

    2010-01-08

    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.

  11. Semiconducting transition metal oxides

    NASA Astrophysics Data System (ADS)

    Lany, Stephan

    2015-07-01

    Open shell transition metal oxides are usually described as Mott or charge transfer insulators, which are often viewed as being disparate from semiconductors. Based on the premise that the presence of a correlated gap and semiconductivity are not mutually exclusive, this work reviews electronic structure calculations on the binary 3d oxides, so to distill trends and design principles for semiconducting transition metal oxides. This class of materials possesses the potential for discovery, design, and development of novel functional semiconducting compounds, e.g. for energy applications. In order to place the 3d orbitals and the sp bands into an integrated picture, band structure calculations should treat both contributions on the same footing and, at the same time, account fully for electron correlation in the 3d shell. Fundamentally, this is a rather daunting task for electronic structure calculations, but quasi-particle energy calculations in GW approximation offer a viable approach for band structure predictions in these materials. Compared to conventional semiconductors, the inherent multivalent nature of transition metal cations is more likely to cause undesirable localization of electron or hole carriers. Therefore, a quantitative prediction of the carrier self-trapping energy is essential for the assessing the semiconducting properties and to determine whether the transport mechanism is a band-like large-polaron conduction or a small-polaron hopping conduction. An overview is given for the binary 3d oxides on how the hybridization between the 3d crystal field symmetries with the O-p orbitals of the ligands affects the effective masses and the likelihood of electron and hole self-trapping, identifying those situations where small masses and band-like conduction are more likely to be expected. The review concludes with an illustration of the implications of the increased electronic complexity of transition metal cations on the defect physics and doping, using as an example the diversity of possible atomic and magnetic configurations of the O vacancy in TiO2, and the high levels of hole doping in Co2ZnO4 due to a self-doping mechanism that originates from the multivalence of Co.

  12. Transition Metal Switchable Mirror

    SciTech Connect

    2009-08-21

    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.

  13. MINEHOUND: transition to production

    NASA Astrophysics Data System (ADS)

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

    2007-04-01

    The UK Department for International Development (DfID), in collaboration with the German Foreign Ministry (Auswrtiges 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.

  14. Semiconducting transition metal oxides.

    PubMed

    Lany, Stephan

    2015-07-22

    Open shell transition metal oxides are usually described as Mott or charge transfer insulators, which are often viewed as being disparate from semiconductors. Based on the premise that the presence of a correlated gap and semiconductivity are not mutually exclusive, this work reviews electronic structure calculations on the binary 3d oxides, so to distill trends and design principles for semiconducting transition metal oxides. This class of materials possesses the potential for discovery, design, and development of novel functional semiconducting compounds, e.g. for energy applications. In order to place the 3d orbitals and the sp bands into an integrated picture, band structure calculations should treat both contributions on the same footing and, at the same time, account fully for electron correlation in the 3d shell. Fundamentally, this is a rather daunting task for electronic structure calculations, but quasi-particle energy calculations in GW approximation offer a viable approach for band structure predictions in these materials. Compared to conventional semiconductors, the inherent multivalent nature of transition metal cations is more likely to cause undesirable localization of electron or hole carriers. Therefore, a quantitative prediction of the carrier self-trapping energy is essential for the assessing the semiconducting properties and to determine whether the transport mechanism is a band-like large-polaron conduction or a small-polaron hopping conduction. An overview is given for the binary 3d oxides on how the hybridization between the 3d crystal field symmetries with the O-p orbitals of the ligands affects the effective masses and the likelihood of electron and hole self-trapping, identifying those situations where small masses and band-like conduction are more likely to be expected. The review concludes with an illustration of the implications of the increased electronic complexity of transition metal cations on the defect physics and doping, using as an example the diversity of possible atomic and magnetic configurations of the O vacancy in TiO(2), and the high levels of hole doping in Co(2)ZnO(4) due to a self-doping mechanism that originates from the multivalence of Co. PMID:26126022

  15. Transition Metal Switchable Mirror

    SciTech Connect

    2009-01-01

    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

  16. Transition Path Theory

    NASA Astrophysics Data System (ADS)

    vanden-Eijnden, E.

    The dynamical behavior of many systems arising in physics, chemistry, biology, etc. is dominated by rare but important transition events between long lived states. For over 70 years, transition state theory (TST) has provided the main theoretical framework for the description of these events [17,33,34]. Yet, while TST and evolutions thereof based on the reactive flux formalism [1, 5] (see also [30,31]) give an accurate estimate of the transition rate of a reaction, at least in principle, the theory tells very little in terms of the mechanism of this reaction. Recent advances, such as transition path sampling (TPS) of Bolhuis, Chandler, Dellago, and Geissler [3, 7] or the action method of Elber [15, 16], may seem to go beyond TST in that respect: these techniques allow indeed to sample the ensemble of reactive trajectories, i.e. the trajectories by which the reaction occurs. And yet, the reactive trajectories may again be rather uninformative about the mechanism of the reaction. This may sound paradoxical at first: what more than actual reactive trajectories could one need to understand a reaction? The problem, however, is that the reactive trajectories by themselves give only a very indirect information about the statistical properties of these trajectories. This is similar to why statistical mechanics is not simply a footnote in books about classical mechanics. What is the probability density that a trajectory be at a given location in state-space conditional on it being reactive? What is the probability current of these reactive trajectories? What is their rate of appearance? These are the questions of interest and they are not easy to answer directly from the ensemble of reactive trajectories. The right framework to tackle these questions also goes beyond standard equilibrium statistical mechanics because of the nontrivial bias that the very definition of the reactive trajectories imply - they must be involved in a reaction. The aim of this chapter is to introduce the reader to the probabilistic framework one can use to characterize the mechanism of a reaction and obtain the probability density, current, rate, etc. of the reactive trajectories.

  17. Pivotal Transitions - Historical and Today

    NASA Astrophysics Data System (ADS)

    Hurley, M.

    2008-08-01

    The goal of this paper is to enable readers to better "design" successful transitions that move Science and Technology or Research and Development (S&T/R&D) technologies and systems into operational capabilities for users. Transitions from S&T/R&D into acquisition and operations are challenging and critical to providing capab ilities to end users. Two historical examples, the Global Positioning System (GPS) and the Disaster Monitoring Constellation (DMC), are explored. Two current examples are also explored, including one from Operationally Responsive Space (ORS) which is in th e early stages of transition. While transitions are necessary, transition periods are inherently challenging and dynamically changing situations. These situations must be carefully managed and led in order to succeed. Characteristics, approaches, and incentives that foster effective transitions are discussed. Understanding the transition process and the communities involved allows one to maximize the chance of successfully moving an S&T/R&D development into an operational capability supporting end users.

  18. 309 Building transition plan

    SciTech Connect

    Graves, C.E.

    1994-08-31

    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.

  19. Planet Demographics from Transits

    NASA Astrophysics Data System (ADS)

    Howard, Andrew

    2015-08-01

    From the demographics of planets detected by the Kepler mission, we have learned that there exists approximately one planet per star for planets larger than Earth orbiting inside of 1 AU. We have also learned the relative occurrence of these planets as a function of their orbital periods, sizes, and host star masses and metallicities. In this talk I will review the key statistical findings that the planet size distribution peaks in the range 1-3 times Earth-size, the orbital period distribution is characterized by a power-law cut off at short periods, small planets are more prevalent around small stars, and that approximately 20% of Sun-like stars hosts a planet 1-2 times Earth-size in a habitable zone. Looking forward, I will describe analysis of photometry from the K2 mission that is yielding initial planet discoveries and offering the opportunity to measure planet occurrence in widely separated regions of the galaxy. Finally, I will also discuss recent techniques to discover transiting planets in space-based photometry and to infer planet population properties from the ensemble of detected and non-detected transit signals.

  20. Phases and Phase Transitions

    NASA Astrophysics Data System (ADS)

    Gitterman, Moshe

    2014-09-01

    In discussing phase transitions, the first thing that we have to do is to define a phase. This is a concept from thermodynamics and statistical mechanics, where a phase is defined as a homogeneous system. As a simple example, let us consider instant coffee. This consists of coffee powder dissolved in water, and after stirring it we have a homogeneous mixture, i.e., a single phase. If we add to a cup of coffee a spoonful of sugar and stir it well, we still have a single phase -- sweet coffee. However, if we add ten spoonfuls of sugar, then the contents of the cup will no longer be homogeneous, but rather a mixture of two homogeneous systems or phases, sweet liquid coffee on top and coffee-flavored wet sugar at the bottom...

  1. Pubertal transitions in health.

    PubMed

    Patton, George C; Viner, Russell

    2007-03-31

    Puberty is accompanied by physical, psychological, and emotional changes adapted to ensure reproductive and parenting success. Human puberty stands out in the animal world for its association with brain maturation and physical growth. Its effects on health and wellbeing are profound and paradoxical. On the one hand, physical maturation propels an individual into adolescence with peaks in strength, speed, and fitness. Clinicians have viewed puberty as a point of maturing out of childhood-onset conditions. However, puberty's relevance for health has shifted with a modern rise in psychosocial disorders of young people. It marks a transition in risks for depression and other mental disorders, psychosomatic syndromes, substance misuse, and antisocial behaviours. Recent secular trends in these psychosocial disorders coincide with a growing mismatch between biological and social maturation, and the emergence of more dominant youth cultures. PMID:17398312

  2. Hybrid Electric Transit Bus

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A.

    1997-01-01

    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.

  3. Partnership Transitions and Maternal Parenting

    PubMed Central

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

    2011-01-01

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

  4. Transition in hypersonic boundary layers

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanhong; Zhu, Yiding; Chen, Xi; Yuan, Huijing; Wu, Jiezhi; Chen, Shiyi; Lee, Cunbiao; Gad-el-Hak, Mohamed

    2015-10-01

    Transition and turbulence production in a hypersonic boundary layer is investigated in a Mach 6 wind tunnel using Rayleigh-scattering visualization, fast-response pressure measurements, and particle image velocimetry. It is found that the second-mode instability is a key modulator of the transition process. Although the second-mode is primarily an acoustic wave, it causes the formation of high-frequency vortical waves, which triggers a fast transition to turbulence.

  5. Diffusion phase transitions in alloys

    NASA Astrophysics Data System (ADS)

    Ustinovshchikov, Yu I.

    2014-07-01

    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.

  6. Quantum phase transition in space

    SciTech Connect

    Damski, Bogdan; Zurek, Wojciech H

    2008-01-01

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

  7. Transit administration and planning research

    SciTech Connect

    de Corla-Souza; Gupta.

    1989-01-01

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

  8. Transition Assessment: Using Gap Analysis to Enhance Effective Transition Planning

    ERIC Educational Resources Information Center

    Lowenthal, Alison B.; Bassett, Diane S.

    2012-01-01

    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…

  9. Presidential Transition Teams: Fostering a Collaborative Transition Process

    ERIC Educational Resources Information Center

    Artman, Richard B.; Franz, Mark

    2009-01-01

    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

  10. Essentials of Transition Planning. Brookes Transition to Adulthood Series

    ERIC Educational Resources Information Center

    Wehman, Paul

    2011-01-01

    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…

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

    SciTech Connect

    Chandler, K.; Eudy, L.

    2008-10-01

    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.

  12. Gauss-Matuyama Polarity Transition

    NASA Astrophysics Data System (ADS)

    Liddicoat, J. C.

    1982-08-01

    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.

  13. Phase transitions in disordered systems

    NASA Astrophysics Data System (ADS)

    Hrahsheh, Fawaz Y.

    Disorder can have a wide variety of consequences for the physics of phase transitions. Some transitions remain unchanged in the presence of disorder while others are completely destroyed. In this thesis we study the effects of disorder on several classical and quantum phase transitions in condensed matter systems. After a brief introduction, we study the ferromagnetic phase transition in a randomly layered Heisenberg magnet using large-scale Monte-Carlo simulations. Our results provide numerical evidence for the exotic infinite-randomness scenario. We study classical and quantum smeared phase transitions in substitutional alloys A1-xBx. Our results show that the disorder completely destroys the phase transition with a pronounced tail of the ordered phase developing for all compositions x < 1. In addition, we find that short-ranged disorder correlations can have a dramatic effect on the transition. Moreover, we show an experimental realization of the composition-tuned ferromagnetic-to-paramagnetic quantum phase transition in Sr1-xCa xRuO3. We investigate the effects of disorder on first-order quantum phase transitions on the example of the N-color quantum Ashkin-Teller model. By means of a strong disorder renormalization group, we demonstrate that disorder rounds the first-order transition to a continuous one for both weak and strong coupling between the colors. Finally, we investigate the superfluid-insulator quantum phase transition of one-dimensional bosons with off-diagonal disorder by means of large-scale Monte-Carlo simulations. Beyond a critical disorder strength, we find nonuniversal, disorder dependent critical behavior.

  14. Europe's second demographic transition.

    PubMed

    Van De Kaa, D J

    1987-03-01

    By 1985, fertility rates in Europe were below the replacement level of 2.1 births/woman in all but Albania, Ireland, Malta, Poland, and Turkey, following a steady decline from a 1965 postwar peak well above 2.5 in Northern, Western, and Southern Europe and an erratic trend from a lower level in Eastern Europe. Natural decrease (fewer births than deaths) had begun already in Austria, Denmark, Hungary, and the Federal Republic of Germany and can be expected shortly in many other countries. According to current UN medium projections, Europe's population (minus the USSR) will grow only 6% between 1985 and 2025, from 492 to 524 million and 18.4% of the population in 2025 will be 65 and over. The decline to low fertility in the 1930s during Europe's 1st demographic transition was propelled by a concern for family and offspring. Behind the 2nd transition is a dramatic shift in norms toward progressiveness and individualism, which is moving Europeans away from marriage and parenthood. Cohabitation and out-of-wedlock fertility are increasingly acceptable; having a child is more and more a deliberate choice made to achieve greater self-fulfillment. Many Europeans view population decline and aging as threats to national influence and the welfare state. However, governments outside Eastern Europe, except for France, have hesitated to try politically risky and costly economic pronatalist incentives. As used in Eastern Europe, coupled with some restrictions on legal abortion, such incentives have not managed to boost fertility back up to replacement level. Immigration as a solution is unfeasible. All countries of immigration have now imposed strict controls, tried to stimulate return migration of guestworkers recruited during labor shortages of the 1960s and early 1970s, and now aim at rapid integration of minorities. Only measures compatible with the shift to individualism might slow or reverse the fertility decline, but a rebound to replacement level seems unlikely and long-term population decline appears inevitable for most of Europe. PMID:12268395

  15. Detection by Transit Photometry

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  16. Brunton Pocket Transit, 1960s

    First patented in 1894, the pocket transit is a relatively simple instrument which provides horizontal and vertical readings; it has adjustable sights and also can function as a plumb bob. The pocket transit is commonly used in geologic mapping, surveying and claim staking. Although the basic design...

  17. Partnership Transitions and Maternal Parenting

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  18. Transitivity of conservative toral endomorphisms

    NASA Astrophysics Data System (ADS)

    Andersson, Martin

    2016-03-01

    It is shown that if a non-invertible area preserving local homeomorphism on {{{T}}2} is homotopic to a linear expanding or hyperbolic endomorphism, then it must be topologically transitive. This gives a complete characterization, in any smoothness category, of those homotopy classes of conservative endomorphisms that consist entirely of transitive maps.

  19. Transition radiation of multicharged ions

    NASA Astrophysics Data System (ADS)

    Malyshevsky, V. S.; Fomin, G. V.; Ivanova, I. A.

    2015-09-01

    The problem of the effect of charge exchange processes of multiply charged accelerated ions in a medium on transition-radiation characteristics is solved. It is shown that the capture (or loss) of electrons by accelerated multiply charged ions at the interface of two media leads to considerable increasing the transition irradiation yield at the achievement of equilibrium charge in a medium.

  20. Adult Transition Program without Walls

    ERIC Educational Resources Information Center

    Moberg, Eric

    2010-01-01

    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…

  1. Transition Programs: Bridging the Gap.

    ERIC Educational Resources Information Center

    Peavey, Kay

    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…

  2. Transition Planning for Foster Youth

    ERIC Educational Resources Information Center

    Geenen, Sarah J.; Powers, Laurie E.

    2006-01-01

    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…

  3. Sampling diffusive transition paths

    SciTech Connect

    F. Miller III, Thomas; Predescu, Cristian

    2006-10-12

    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.

  4. Fibre and bowel transit times.

    PubMed

    Gear, J S; Brodribb, A J; Ware, A; Mann, J I

    1981-01-01

    1. Bowel transit time has been investigated in vegetarians and non-vegetarians and related to dietary fibre intake and the presence of diverticular disease. 2. Vegetarians who have less diverticular disease than non-vegetarians have more rapid transit times. 3. Subjects with total dietary fibre intake of more than 30 g/d all had transit times of less than 75 h whereas 38% of those eating less had transit times exceeding 75 h and varying up to 124 h. 4. Individuals with diverticular disease were found to have faster transit times than those without the disease. 5. The colon may respond to a fibre-depleted diet either by becoming hyperactive and prone to diverticular disease or by becoming hypoactive leading to constipation. PMID:6258626

  5. Selenophene transition metal complexes

    SciTech Connect

    White, C.J.

    1994-07-27

    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.

  6. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  7. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  8. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  9. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  10. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  11. The Visibility of Earth Transits

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  12. The Visibility of Earth Transits

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  13. Transition Probabilities of Gd I

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  14. Electronic Transitions of Yttrium Monophosphide

    NASA Astrophysics Data System (ADS)

    Cheung, Allan S. C.; Li, Biu Wa; Chan, MAN-CHOR

    2015-06-01

    Electronic transition spectrum of the yttrium monophosphide (YP) molecule in the visible region between 715 nm and 880 nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The YP molecule was produced by reacting laser - ablated yttrium atoms with PH3 seeded in argon. Thirteen vibrational bands were analyzed and five electronic transition systems have identified, namely the [12.2] Ω = 3 - X3 Π_2 transition, [13.3] Ω = 3 - X3 Π_2 transition, [13.4] Ω = 3 - X3 Π_2 transition, [13.5] Ω = 3 - X3 Π_2 transition, and [13.4] Ω = 2 - X3 Π_2 transition. Least squares fits of the measured rotational lines yielded molecular constants for the ground and excited states. The ground state symmetry and the bond length r_0 of the YP molecule have been determined to be a X3 Π_2 state and 2.4413 Å respectively in this work. A molecular orbital energy level diagram has been used to help the assignment of the observed electronic states. This work represents the first experimental investigation of the spectrum of the YP molecule.

  15. Major evolutionary transitions in individuality.

    PubMed

    West, Stuart A; Fisher, Roberta M; Gardner, Andy; Kiers, E Toby

    2015-08-18

    The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven't taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. PMID:25964342

  16. Major evolutionary transitions in individuality

    PubMed Central

    West, Stuart A.; Fisher, Roberta M.; Gardner, Andy; Kiers, E. Toby

    2015-01-01

    The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. PMID:25964342

  17. Magnetic TRAnsition Region Probe (MTRAP)

    NASA Technical Reports Server (NTRS)

    Moore, R. L.; Davis, John; Hathaway, David; Six, N. Frank (Technical Monitor)

    2002-01-01

    MTRAP (Magnetic Transition Region Probe) will reveal the fine-scale physical processes in the Sun's magnetic transition region, the complex layer from the upper photosphere to the upper chromosphere/lower transition region. In the magnetic transition region plasma forces and magnetic forces are of comparable strength, which results in complex interplay of the two, which interplay governs the coupling of the convectively-driven deeper layers to the magnetically-driven upper transition region and inner corona. The fine-scale magnetic structure, processes, and events in the magnetic transition region are key to the genesis of the Sun's entire hot, dynamic outer atmosphere and to the initiation of large eruptive events. MTRAP will be a single spacecraft in Sun-synchronous Earth orbit. Because MTRAP will probe and measure the 3-D structure and dynamics of the magnetic field and plasma in the chromosphere and transition region with unprecedented resolution, the required telescope size and telemetry rates dictate that MTRAP be in Earth orbit, not in deep space. The observations will feature visible and infrared maps of vector magnetic and velocity fields in the magnetic transition region and photosphere. These will have large field of view (greater than 100,000 km), high resolution (greater than 100 km), and high sensitivity (greater than 30 G in transverse field). These observations of the lower atmosphere will be complemented by UV maps of the structure, velocity, and magnetic field (including the full vector field if technically feasible) higher up, in the upper chromosphere and lower transition region. MTRAP will also have an EUV imaging spectrograph observing coronal structure and dynamics in the same field of view with comparable resolution. Specific phenomena to be analyzed include spicules, bright points, jets, the base of plumes, and the triggering of eruptive flares and coronal mass ejections. Additional information is included in the original extended abstract.

  18. Phase transition in Liouville theory

    NASA Astrophysics Data System (ADS)

    Johnston, D.

    1989-11-01

    We suggest that the vortices arising in a Kosterlitz-Thouless phase transition in Liouville theory correspond to transitions between different genera, producing the ``plumber's nightmare'' and other phases that have been predicted in fluid membrane theory from energetic considerations. This transition has previously been invoked by Cates to explain the degeneration of numerical simulations of Gaussian random surfaces into branched polymers. The difficulty in quantizing Liouville theory for d>1 is conjectured to be due to our insistence on working at a fixed genus.

  19. Transition circumnstellar disks in Lupus

    NASA Astrophysics Data System (ADS)

    Romero, G. A.; Schreiber, M. R.; Cieza, L. A.; Rebassa-Manssergas, A.; Williams, J. P.; Merin, B.; Smith-Castelli, A.; Orellana, M.

    2011-10-01

    Based on Spitzer selected YSOs, we present a study of transition disks located in Lupus. Several mechanisms have been proposed to explain their defining characteristic: an inner opacity hole and an optically thick outer disk. These processes are: planet formation, grain growth, photoevaporation, tidal truncation in close binaries. We have carried out Adaptive Optics (AO) imaging, submillimeter photometry, and echelle spectroscopy in order to observationally characterize our transition disk sample. With the analyzed data we can distinguish the four scenarios and identify candidate transition disk systems that are currently forming planets. Such objects are excellent targets to be followed-up with Herschel and ALMA.

  20. Fluctuation driven electroweak phase transition

    NASA Technical Reports Server (NTRS)

    Gleiser, Marcelo; Kolb, Edward W.

    1991-01-01

    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.

  1. Next Generation Transit Survey (NGTS)

    NASA Astrophysics Data System (ADS)

    Wheatley, Peter J.; Pollacco, Don L.; Queloz, Didier; Rauer, Heike; Watson, Christopher A.; West, Richard G.; Chazelas, Bruno; Louden, Tom M.; Bannister, Nigel; Bento, Joao; Burleigh, Matthew; Cabrera, Juan; Eigmüller, Philipp; Erikson, Anders; Genolet, Ludovic; Goad, Michael; Grange, Andrew; Jordán, Andrés; Lawrie, Katherine; McCormac, James; Neveu, Marion; Walker, Simon

    2014-01-01

    The Next Generation Transit Survey (NGTS) is a new ground-based survey for transiting exoplanets. Our primary goal is to find the first statistically-significant sample of Neptunes and super-Earths that are bright enough for radial velocity confirmation. By measuring precise masses and radii we will constrain the bulk composition and internal structure of planets that span the transition between the gas giants and terrestrial planets. Our brightest exoplanets will also be suitable for atmospheric characterisation with large facilities such as the VLT, JWST and the E-ELT. NGTS construction began in June 2013, and the survey is due to commence in 2014.

  2. Nonradiative transition dynamics in alexandrite

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    The first direct picosecond time-resolved measurement of the nonradiative transition dynamics between the excited 4T2 pump band and the metastable 2E storage level of the trivalent chromium ion in alexandrite is reported. The nonradiative relaxation times of 17 ps for intra-4T2 vibrational transitions, and 27 ps for 4T2-2E electronic transition are obtained. The thermal repopulation rate of the 4T2 state from the metastable 2E level is of the order 3.5 x 10 to the 9th per s.

  3. Transition to turbulence in pipe flow as a phase transition

    NASA Astrophysics Data System (ADS)

    Vasudevan, Mukund; Hof, Björn

    2015-11-01

    In pipe flow, turbulence first arises in the form of localized turbulent patches called puffs. The flow undergoes a transition to sustained turbulence via spatio-temporal intermittency, with puffs splitting, decaying and merging in the background laminar flow. However, the due to mean advection of the puffs and the long timescales involved (~107 advective time units), it is not possible to study the transition in typical laboratory set-ups. So far, it has only been possible to indirectly estimate the critical point for the transition. Here, we exploit the stochastic memoryless nature of the puff decay and splitting processes to construct a pipe flow set-up, that is periodic in a statistical sense. It then becomes possible to study the flow for sufficiently long times and characterize the transition in detail. We present measurements of the turbulent fraction as a function of Reynolds number which in turn allows a direct estimate of the critical point. We present evidence that the transition has features of a phase transition of second order.

  4. India's population in transition.

    PubMed

    Visaria, L; Visaria, P

    1995-10-01

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

  5. Parity nonconservation in atomic Zeeman transitions

    SciTech Connect

    Angstmann, E. J.; Dinh, T. H.; Flambaum, V. V.

    2005-11-15

    We discuss the possibility of measuring nuclear anapole moments in atomic Zeeman transitions and perform the necessary calculations. Advantages of using Zeeman transitions include variable transition frequencies and the possibility of enhancement of parity nonconservation effects.

  6. Magnetic dipole transitions in crystals

    NASA Astrophysics Data System (ADS)

    Wybourne, Brian G.; Smentek, Lidia; Kȩdziorski, Andrzej

    2004-01-01

    The magnetic dipole transitions in rare earth ions in crystals are described in terms of a model based on the fourth order perturbation theory. An analysis of the perturbing influence of crystal field potential and spin-orbit interaction is made. In addition to intra-shell interactions, inter-shell interactions that include the influence of the excited configurations are analysed. The transition amplitude is defined in terms of effective operators expressed by double unit tensor operators. The radial integrals of all effective operators are defined within the perturbed function approach, therefore the complete radial basis sets of one-electron states of given symmetry are taken into account. Conclusions mainly focus on the possible importance of magnetic dipole transitions in the description of electric dipole 0 ↔ 0 transition due to the so-called borrowing mechanism.

  7. Evolutionary transitions in bacterial symbiosis

    PubMed Central

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the capture of beneficial symbionts via the evolution of strict vertical transmission within host lineages, and the evolutionary breakdown of bacterial mutualism. Each of these transitions has occurred many times in the history of bacterial–eukaryote symbiosis. We investigate these evolutionary events across the bacterial domain and also among a focal set of well studied bacterial mutualist lineages. Subsequently, we generate a framework for examining evolutionary transitions in bacterial symbiosis and test hypotheses about the selective, ecological, and genomic forces that shape these events. PMID:21690339

  8. Moved by a Rapid Transit

    NASA Astrophysics Data System (ADS)

    Bueter, C.

    2013-04-01

    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.

  9. Universal Keplerian state transition matrix

    NASA Technical Reports Server (NTRS)

    Shepperd, S. W.

    1985-01-01

    A completely general method for computing the Keplerian state transition matrix in terms of Goodyear's universal variables is presented. This includes a new scheme for solving Kepler's problem which is a necessary first step to computing the transition matrix. The Kepler problem is solved in terms of a new independent variable requiring the evaluation of only one transcendental function. Furthermore, this transcendental function may be conveniently evaluated by means of a Gaussian continued fraction.

  10. Transitions in turbulent rotating convection

    NASA Astrophysics Data System (ADS)

    Rajaei, Hadi; Alards, Kim; Kunnen, Rudie; Toschi, Federico; Clercx, Herman; Fluid Dynamics Lab Team

    2015-11-01

    This study aims to explore the flow transition from one state to the other in rotating Rayleigh-Bènard convection using Lagrangian acceleration statistics. 3D particle tracking velocimetry (3D-PTV) is employed in a water-filled cylindrical tank of equal height and diameter. The measurements are performed at the center and close to the top plate at a Rayleigh number Ra = 1.28e9 and Prandtl number Pr = 6.7 for different rotation rates. In parallel, direct numerical simulation (DNS) has been performed to provide detailed information on the boundary layers. We report the acceleration pdfs for different rotation rates and show how the transition from weakly to strongly rotating Rayleigh-Bènard affects the acceleration pdfs in the bulk and boundary layers. We observe that the shapes of the acceleration PDFs as well as the isotropy in the cell center are largely unaffected while crossing the transition point. However, acceleration pdfs at the top show a clear change at the transition point. Using acceleration pdfs and DNS data, we show that the transition between turbulent states is actually a boundary layer transition between Prandtl-Blasius type (typical of non-rotating convection) and Ekman type.

  11. Modelling the transitional boundary layer

    NASA Technical Reports Server (NTRS)

    Narasimha, R.

    1990-01-01

    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.

  12. Boundary layer transition studies

    NASA Technical Reports Server (NTRS)

    Watmuff, Jonathan H.

    1995-01-01

    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.

  13. Transition boiling heat transfer and the film transition regime

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  14. UV transition moments of tyrosine.

    PubMed

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

    2014-08-01

    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 π-π* 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 ωB97X-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

  15. 33 CFR 401.74 - Transit declaration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Transit declaration. 401.74... Transit declaration. (a) Seaway Transit Declaration Form (Cargo and Passenger) shall be forwarded to the... ships, within fourteen days after the vessel enters the Seaway on any upbound or downbound transit....

  16. 33 CFR 401.74 - Transit declaration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Transit declaration. 401.74... Transit declaration. (a) Seaway Transit Declaration Form (Cargo and Passenger) shall be forwarded to the... ships, within fourteen days after the vessel enters the Seaway on any upbound or downbound transit....

  17. 33 CFR 401.74 - Transit declaration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Transit declaration. 401.74... Transit declaration. (a) A Seaway Transit Declaration Form (Cargo and Passenger) shall be forwarded to the... bound transit. The form may be obtained from the St. Lawrence Management Corporation, 151 Ecluse...

  18. 33 CFR 401.74 - Transit declaration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Transit declaration. 401.74... Transit declaration. (a) Seaway Transit Declaration Form (Cargo and Passenger) shall be forwarded to the... ships, within fourteen days after the vessel enters the Seaway on any upbound or downbound transit....

  19. Career Transitions of Supervisors and Subordinates.

    ERIC Educational Resources Information Center

    Stout, Suzanne K.; And Others

    1987-01-01

    Examined career transitions of supervisors to determine the impact of their transitions on behaviors and attitudes of subordinates who had made recent career transitions. Data from 124 managers and subordinates revealed that the magnitude of both a supervisor's and subordinate's career transition interacted to affect subordinate's commitment to…

  20. Family-Directed Transition Planning Guide.

    ERIC Educational Resources Information Center

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

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

  1. Multilevel Models for Studying Organizational Transition Effects.

    ERIC Educational Resources Information Center

    Kang, Sang-Jin

    Over the past 15 years a body of research has investigated organizational transitions in adolescent development. Researchers studying school transitions exclusively ask whether significant transition affects students' social and psychological development. To test the presence of transition effects, researchers have typically observed mean…

  2. Structural transition in peptide nanotubes.

    PubMed

    Amdursky, Nadav; Beker, Peter; Koren, Itai; Bank-Srour, Becky; Mishina, Elena; Semin, Sergey; Rasing, Theo; Rosenberg, Yuri; Barkay, Zahava; Gazit, Ehud; Rosenman, Gil

    2011-04-11

    Phase transitions in organic and inorganic materials are well-studied classical phenomena, where a change in the crystal space group symmetry induces a wide variation of physical properties, permitted by the crystalline symmetry in each phase. Here we observe a conformational induced transition in bioinspired peptide nanotubes (PNTs). We found that the PNTs change their original molecular assembly from a linear peptide conformation to a cyclic one, followed by a change of the nanocrystalline structure from a noncentrosymmetric hexagonal space group to a centrosymmetric orthorhombic space group. The observed transition is irreversible and induces a profound variation in the PNTs properties, from the microscopic to the macroscopic level. In this context, we follow the unique changes in the molecular, morphological, piezoelectric, second harmonic generation, and wettability properties of the PNTs. PMID:21388228

  3. Transition metals in superheat melts

    NASA Technical Reports Server (NTRS)

    Jakes, Petr; Wolfbauer, Michael-Patrick

    1993-01-01

    A series of experiments with silicate melts doped with transition element oxides was carried out at atmospheric pressures of inert gas at temperatures exceeding liquidus. As predicted from the shape of fO2 buffer curves in T-fO2 diagrams the reducing conditions for a particular oxide-metal pair can be achieved through the T increase if the released oxygen is continuously removed. Experimental studies suggest that transition metals such as Cr or V behave as siderophile elements at temperatures exceeding liquidus temperatures if the system is not buffered by the presence of other oxide of more siderophile element. For example the presence of FeO prevents the reduction of Cr2O3. The sequence of decreasing siderophility of transition elements at superheat conditions (Mo, Ni, Fe, Cr) matches the decreasing degree of depletion of siderophile elements in mantle rocks as compared to chondrites.

  4. Implementing transition: Ready Steady Go

    PubMed Central

    Nagra, Arvind; McGinnity, Patricia M; Davis, Nikki; Salmon, Anthony P

    2015-01-01

    There is good evidence that morbidity and mortality increase for young persons (YP) following the move from paediatric to adult services. Studies show that effective transition between paediatric and adult care improves long-term outcomes. Many of the issues faced by young people across subspecialties with a long-term condition are generic. This article sets out some of the obstacles that have delayed the implementation of effective transition. It reports on a successful generic transition programme ‘Ready Steady Go’ that has been implemented within a large National Health Service teaching hospital in the UK, with secondary and tertiary paediatric services, where it is now established as part of routine care. PMID:26063244

  5. Cosmological phase transitions and baryogenesis

    SciTech Connect

    Quiros, Mariano

    1998-10-05

    We review various aspects of field theory at finite temperature related to the theory of phase transitions. In particular, the real and imaginary time formalisms are discussed, showing their equivalence in simple examples. Bubble nucleation by thermal tunneling, and the subsequent development of the phase transition is described in some detail. Some attention is also devoted to the breakdown of the perturbative expansion and the infrared problem in the finite temperature field theory. Finally the application to baryogenesis at the electroweak phase transition is done in the Standard Model and in the Minimal Supersymmetric Standard Model. In all cases we have translated the condition of not washing out any previously generated baryon asymmetry by upper bounds on the Higgs mass.

  6. Electronic transitions of iridium monophosphide

    NASA Astrophysics Data System (ADS)

    Yang, M.; Chan, Man-Chor; Cheung, A. S.-C.

    2016-05-01

    Laser induced fluorescence spectrum of IrP in the near infrared spectral region between 720 and 820 nm has been recorded and analyzed. Six vibrational bands with resolved rotational structure for both 191IrP and 193IrP were analyzed, they have been grouped into three new electronic transitions: the [13.6] Ω = 2 - a3Π2, the [12.3]1Π1-X1Σ+, and the [12.7]1Π1-X1Σ+ transitions. Ab initio calculation results were used to aid the assignment of the observed transitions. A new triplet state has been observed for the first time. The observed electronic states of IrP are compared with those of the isovalent IrN molecule.

  7. Understanding epidemiological transition in India

    PubMed Central

    Yadav, Suryakant; Arokiasamy, Perianayagam

    2014-01-01

    Background Omran's theory explains changing disease patterns over time predominantly from infectious to chronic noncommunicable diseases (NCDs). India's epidemiological transition is characterized by dual burden of diseases. Kumar addressed low mortality and high morbidity in Kerala, which seems also to be true for India as a country in the current demographic scenario. Methods NSS data (1986–1987, 1995–1996, 2004) and aggregated data on causes of death provided by Registrar General India (RGI) were used to examine the structural changes in morbidity and causes of death. A zero-inflated poisson (ZIP) regression model and a beta-binomial model were used to corroborate the mounting age pattern of morbidity. Measures, namely the 25th and 75th percentiles of age-at-death and modal age-at-death, were used to examine the advances in mortality transition. Objective This study addressed the advances in epidemiological transition via exploring the structural changes in pattern of diseases and progress in mortality transition. Results The burden of NCDs has been increasing in old age without replacing the burden of communicable diseases. The manifold rise of chronic diseases in recent decades justifies the death toll and is responsible for transformation in the age pattern of morbidity. Over time, deaths have been concentrated near the modal age-at-death. Modal age-at-death increased linearly by 5 years for females (r2=0.9515) and males (r2=0.9020). Significant increase in modal age-at-death ascertained the dominance of old age mortality over the childhood/adult age mortality. Conclusions India experiences a dual burden of diseases associated with a remarkable transformation in the age pattern of morbidity and mortality, contemporaneous with structural changes in disease patterns. Continued progress in the pattern of diseases and mortality transition, accompanied by a linear rise in ex, unravels a compelling variation in advances found so far in epidemiological transition witnessed by the developed nations, with similar matrices for India. PMID:24848651

  8. Transition probabilities and static moments in transitional nuclei

    SciTech Connect

    Wolf, A.; Casten, R.F.

    1988-01-01

    Electromagnetic transition probabilities and static moments of excited nuclear states are known to be good probes of nuclear structure. Therefore, a systematic analysis of the large amount of existing experimental data for these observables is expected to provide valuable information about the respective isotopes. It is the purpose of this talk to show that a combined analysis of static magnetic moments of 2/sub 1//sup +/ states and B(E2) transition probabilities for even-even nuclei can be used to obtain effective numbers of valence nucleons. This kind of information is of particular interest in cases where subshell closures are found. For example, it is well known that for the transitional nuclei in the A = 150 region the Z = 64 subshell is active when the number of neutrons N < 90, but disappears for N greater than or equal to 90. A similar situation exists in the A = 100 region, where the Z = 38 subshell is active for N less than or equal to 58. In the following sections we present the method by which effective numbers of valence protons and neutrons can be deduced from B(E2) and g-factor data, and show applications of this method to the A = 150 and A = 100 transitional regions. Part of these results were recently published.

  9. Wetting transition on patterned surfaces: transition states and energy barriers.

    PubMed

    Ren, Weiqing

    2014-03-18

    We study the wetting transition on microstructured hydrophobic surfaces. We use the string method [J. Chem. Phys. 2007, 126, 164103; J. Chem. Phys. 2013, 138, 134105] to accurately compute the transition states, the energy barriers, and the minimum energy paths for the wetting transition from the Cassie-Baxter state to the Wenzel state. Numerical results are obtained for the wetting of a hydrophobic surface textured with a square lattice of pillars. It is found that the wetting of the solid substrate occurs via infiltration of the liquid in a single groove, followed by lateral propagation of the liquid front. The propagation of the liquid front proceeds in a stepwise manner, and a zipping mechanism is observed during the infiltration of each layer. The minimum energy path for the wetting transition goes through a sequence of intermediate metastable states, whose wetted areas reflect the microstructure of the patterned surface. We also study the dependence of the energy barrier on the drop size and the gap between the pillars. PMID:24564531

  10. Epigenetic switches and network transitions

    NASA Astrophysics Data System (ADS)

    Sasai, Masaki

    2012-02-01

    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.

  11. The migration transition in Malaysia.

    PubMed

    Lim, L L

    1996-01-01

    "Exploring the unique experience of migration transition in Malaysia, this paper identifies the turning points in relation to the level and nature of economic and labor market developments in Malaysia. Examining the development dynamics that mark the passage from exporting labor to depending on foreign labor, the paper concludes that such dynamics are influenced not only by economic but also sociocultural, demographic and policy factors. Several lessons from the Malaysian experience are drawn at the end to be utilized by other countries that still have to reach the turning points of the migration transition." PMID:12320775

  12. Colloquium: Water's controversial glass transitions

    NASA Astrophysics Data System (ADS)

    Amann-Winkel, Katrin; Böhmer, Roland; Fujara, Franz; Gainaru, Catalin; Geil, Burkhard; Loerting, Thomas

    2016-01-01

    Water is the most common and, judged from its numerous anomalous properties, the weirdest of all known liquids and the complexity of its pressure-temperature map is unsurpassed. A major obstacle on the way to a full understanding of water's structure and dynamics is the hard-to-explore territory within this map, colloquially named the no man's land. Many experiments suggest that just before stepping across its low-temperature border, amorphous ices undergo glass-to-liquid transitions while other interpretations emphasize the importance of underlying disordered (nano)crystalline states. Prospects for reconciling the conflicting views regarding the nature of water's glass transitions are discussed.

  13. Mode Transition of Trichel pulses

    NASA Astrophysics Data System (ADS)

    Kexin, Zhang; Yongjun, Piao; Miao, Tang; Jingfeng, Tang; Liqiu, Wei; Chaohai, Zhang

    2015-11-01

    The trichel pulse is a typical kind of negative corona current observed in electronegative gases. In this work, stochastic behavior of the trichel pulse has been investigated. The experiment is performed in a negative corona reactor consisting of a stainless steel pin and a stainless steel powered by a dc high voltage source. The characteristic parameters distributions of corona current pulses, including the amplitude, rise time, half-wave time, and repetition frequency, are analyzed statistically. The results show there is a mode transition during the period of voltage increasing. This transition process happens in a certain voltage region, and change of pulse amplitude is the main difference between the two modes.

  14. Nuclear Multifragmentation & the Phase Transition

    NASA Astrophysics Data System (ADS)

    Scharenberg, Rolf; Srivastava, Brijesh; Hirsch, Andy; Porile, Norbert

    2002-04-01

    A high statistics exclusive study of 1 GeV/nucleon Au, La and Kr on carbon has been performed, where the size and energy of the fragmenting system is measured for each event. The distributions of projectile fragments are analyzed using the statistical multifragmentation model. The nature of the phase transition has been examined using the caloric curve. For lighter systems a backbending is observed in the caloric curve implying a negative specific heat, while for heavier system there is a positive specific heat. This suggests that the breakup of heavier systems (Au and La) is consistent with a continuous phase transition.

  15. Structural transitions in helical polymers

    NASA Astrophysics Data System (ADS)

    Williams, Matthew; Bachmann, Michael; Soft Matter Systems Research Group Team

    2014-03-01

    Helical structures, as well as more complex tertiary structures, made up of helixes are relevant in biological systems. We perform generalized-ensemble Monte Carlo simulations to examine homopolymer models which include a torsional potential energy associated with each bond. With the inclusion of a torsional potential, helical structures emerge and can contort to form a variety of tertiary structural phases. We explore the two-dimensional space, parametrized by temperature and torsional energy scale, to map helical structures and to locate structural transitions. We see transitions occur between helical and non-helical secondary structures and also between various tertiary structures.

  16. William Crabtree's Venus transit observation

    NASA Astrophysics Data System (ADS)

    Kollerstrom, Nicholas

    2005-04-01

    The close collaboration between the two North-country astronomers Jeremiah Horrocks and William Crabtree gave them special insight into the new astronomy published by the recently-deceased Kepler, whereby Horrocks became the only person to apprehend that the Rudolphine tables were in fact predicting a Venus transit in 1639. This paper focuses especially upon William Crabtree's role and contribution. A comparison is made with an earlier, unsuccessful endeavour by these two concerning a possible transit of Mercury. Much of the record of their work was lost during the civil war. Finally, thanks to Christiaan Huygens, Horrock's manuscript was published by Johannes Hevelius in Danzig, in 1662.

  17. Structural Transitions in Superionic Conductors

    NASA Astrophysics Data System (ADS)

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

    1983-04-01

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

  18. Magnetic dipole transitions in the hydrogen molecule

    SciTech Connect

    Pachucki, Krzysztof; Komasa, Jacek

    2011-03-15

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

  19. Dynamic Transitions of Generalized Burgers Equation

    NASA Astrophysics Data System (ADS)

    Li, Limei; Ong, Kiah Wah

    2016-01-01

    In this article, we study the dynamic transition for the one dimensional generalized Burgers equation with periodic boundary condition. The types of transition are dictated by the sign of an explicitly given parameter b, which is derived using the dynamic transition theory developed by Ma and Wang (Phase transition dynamics. Springer, New York, 2014). The rigorous result demonstrates clearly the types of dynamics transition in terms of length scale l, dispersive parameter ? and viscosity ?.

  20. Dynamic Transitions of Generalized Burgers Equation

    NASA Astrophysics Data System (ADS)

    Li, Limei; Ong, Kiah Wah

    2016-03-01

    In this article, we study the dynamic transition for the one dimensional generalized Burgers equation with periodic boundary condition. The types of transition are dictated by the sign of an explicitly given parameter b, which is derived using the dynamic transition theory developed by Ma and Wang (Phase transition dynamics. Springer, New York, 2014). The rigorous result demonstrates clearly the types of dynamics transition in terms of length scale l, dispersive parameter δ and viscosity ν.

  1. Authority Work for Transitional Catalogs.

    ERIC Educational Resources Information Center

    Matters, Marion

    1990-01-01

    Discusses authority work and authority control for personal names and corporate bodies in transitional archive catalogs. The importance of conformance with standards so that archival materials will collocate with other types of material in integrated catalogs is also discussed, together with enhanced authority work and techniques for archival…

  2. Presidential Transitions during Capital Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2008-01-01

    In the past few decades, capital campaigns at institutions of higher education have increased in duration, while collegiate presidential tenures have been doing just the opposite. Turnover in the top post was frequent, even during major fundraising campaigns. Before this study, presidential transitions during campaigns had not been previously…

  3. Life in the Transition Economies.

    ERIC Educational Resources Information Center

    Lopus, Jane

    1998-01-01

    Reports on interviews conducted with Ukrainian teachers who were asked whether they and others they know are better, or worse, off since Ukrainian independence. Addresses inflation, private enterprise, delayed salaries, and new freedoms. Provides insights into the effects of the transition on people's lives and hopes for the future. (DSK)

  4. Transiting Exoplanet Survey Satellite (TESS)

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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.

  5. Electronic transitions of yttrium monophosphide

    NASA Astrophysics Data System (ADS)

    Li, Biu Wa; Chan, Man-Chor; Cheung, A. S.-C.

    2015-11-01

    The electronic transition spectrum of the yttrium monophosphide (YP) molecule in the near infrared region between 715 nm and 880 nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The YP molecule was produced by reacting laser - ablated yttrium atoms with PH3 gas seeded in argon. Eleven vibrational bands were analyzed and six electronic transitions have been identified, namely the [12.17] Ω = 3 - X3Π2, [13.27] Ω = 3 - X3Π2, [13.44] Ω = 3 - X3Π2, [13.46] Ω = 3 - X3Π2 and [13.40] Ω = 2 - X3Π2 transitions and a [13.69] Ω = 3 - a1Δ2 transition. Least squares fits of the measured rotational lines yielded molecular constants for the ground and excited states. The ground state has been determined to be a X3Π2 state and the bond length ro and vibrational separation, ΔG1/2, were determined to be 2.4413 Å and 390.77 cm-1 respectively. A molecular orbital energy level diagram has been used to aid the assignment of the observed electronic states. This work represents the first experimental investigation of the electronic spectrum of the YP molecule.

  6. Leadership Transitions: Keys for Success

    ERIC Educational Resources Information Center

    Goodyear, Marilu; Golden, Cynthia

    2008-01-01

    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

  7. Preterm Birth: Transition to Adulthood

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  8. Gifted Students' Transition to University

    ERIC Educational Resources Information Center

    Mendaglio, Sal

    2013-01-01

    The transition from school to university presents novel demands for all students. Although this educational milestone has been addressed by scholars, particularly those interested in the study of higher education, there is a dearth of literature regarding gifted students' experience of their handling demands of first-year university. In the…

  9. American Higher Education in Transition

    ERIC Educational Resources Information Center

    Ehrenberg, Ronald G.

    2011-01-01

    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…

  10. Narratives about Labour Market Transitions

    ERIC Educational Resources Information Center

    Cort, Pia; Thomsen, Rie

    2014-01-01

    In European Union policy, Denmark is often referred to as a model country in terms of its flexicurity model and provision of financial support and access to education and training during periods of unemployment, i.e. during transitional phases in a working life. However, in the research on flexicurity and its implications for labour market

  11. Stadia Hand Transit with Case

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

  12. Portfolios: Transitioning to the Future.

    ERIC Educational Resources Information Center

    Pond, Beth N.; Burdick, Susan E.; Yamamoto, Joanne K.

    1998-01-01

    The Career Life Plan is a portfolio-based tool for preparing for life transitions. It includes career preparation and assessment information, resumes, interpersonal skills development, writing samples, applications, and letters of recommendation. This working tool reflects students' learning styles, personality types, and career interests. (SK)

  13. Quantifying macromolecular conformational transition pathways

    NASA Astrophysics Data System (ADS)

    Seyler, Sean; Kumar, Avishek; Thorpe, Michael; Beckstein, Oliver

    2015-03-01

    Diverse classes of proteins function through large-scale conformational changes that are challenging for computer simulations. A range of fast path-sampling techniques have been used to generate transitions, but it has been difficult to compare paths from (and assess the relative strengths of) different methods. We introduce a comprehensive method (pathway similarity analysis, PSA) for quantitatively characterizing and comparing macromolecular pathways. The Hausdorff and Fréchet metrics (known from computational geometry) are used to quantify the degree of similarity between polygonal curves in configuration space. A strength of PSA is its use of the full information available from the 3 N-dimensional configuration space trajectory without requiring additional specific knowledge about the system. We compare a sample of eleven different methods for the closed-to-open transitions of the apo enzyme adenylate kinase (AdK) and also apply PSA to an ensemble of 400 AdK trajectories produced by dynamic importance sampling MD and the Geometrical Pathways algorithm. We discuss the method's potential to enhance our understanding of transition path sampling methods, validate them, and help guide future research toward deeper physical insights into conformational transitions.

  14. Narratives about Labour Market Transitions

    ERIC Educational Resources Information Center

    Cort, Pia; Thomsen, Rie

    2014-01-01

    In European Union policy, Denmark is often referred to as a model country in terms of its flexicurity model and provision of financial support and access to education and training during periods of unemployment, i.e. during transitional phases in a working life. However, in the research on flexicurity and its implications for labour market…

  15. Electrical Conductivity in Transition Metals

    ERIC Educational Resources Information Center

    Talbot, Christopher; Vickneson, Kishanda

    2013-01-01

    The aim of this "Science Note" is to describe how to test the electron-sea model to determine whether it accurately predicts relative electrical conductivity for first-row transition metals. In the electron-sea model, a metal crystal is viewed as a three-dimensional array of metal cations immersed in a sea of delocalised valence

  16. Structural transitions of encapsidated polyelectrolytes

    NASA Astrophysics Data System (ADS)

    Angelescu, D. G.; Linse, P.; Nguyen, T. T.; Bruinsma, R. F.

    2008-03-01

    Conformations and structural transitions of polyelectrolytes strictly confined onto a spherical 2D surface have been investigated by scaling descriptions based on physical arguments concerning polyelectrolyte adsorption onto planar surface and liquid crystals as well as by Monte Carlo simulations using a bead-spring model with short-range and electrostatic repulsions. In case of the electrostatic screened regime, a disordered-ordered (spiral) transition at increasing persistence length of the chain was found. It was predicted that the transition occurred when the persistence length is comparable with the mean spacing between adjacent strands of the ordered chain. The presence of a non-screened electrostatic repulsion led to a more complex behavior with i) a re-entrant order-disorder transition and ii) a tennis ball texture as an additional smectic/nematic structure. The various competing structures given by the theory were recovered by the Monte Carlo simulations, which also indicated that the tennis ball texture was favored over the spiral structure by the long-range interactions for semi-flexible chains.

  17. "Mexico in Transition." Curriculum Units.

    ERIC Educational Resources Information Center

    Oregon Univ., Eugene. Foreign Language Resource Center.

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

  18. Leadership Transitions during Fundraising Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2012-01-01

    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…

  19. The Transition to Work Simulator.

    ERIC Educational Resources Information Center

    Conroy, William G., Jr.

    1979-01-01

    This report describes the Transition to Work Simulator (TWS), a computerized model of the important career decisions which people make from youth through midcareer. The implications of TWS as a planning tool for human resource development at the national level are discussed. (Author/SJL)

  20. Alkali and transition metal phospholides

    NASA Astrophysics Data System (ADS)

    Bezkishko, I. A.; Zagidullin, A. A.; Milyukov, V. A.; Sinyashin, O. G.

    2014-06-01

    Major tendencies in modern chemistry of alkali and transition metal phospholides (phosphacyclopentadienides) are systematized, analyzed and generalized. Basic methods of synthesis of these compounds are presented. Their chemical properties are considered with a special focus on their complexing ability. Potential applications of phospholides and their derivatives are discussed. The bibliography includes 184 references.

  1. Flexible Scheduling: Making the Transition

    ERIC Educational Resources Information Center

    Creighton, Peggy Milam

    2008-01-01

    Citing literature that supports the benefits of flexible scheduling on student achievement, the author exhorts readers to campaign for flexible scheduling in their library media centers. She suggests tips drawn from the work of Graziano (2002), McGregor (2006) and Stripling (1997) for making a smooth transition from fixed to flexible scheduling:…

  2. Topological Phase Transition in Antimony

    NASA Astrophysics Data System (ADS)

    Wong, Man-Hong; Bian, Guang; Xu, Caizhi; Miller, Thomas; Chiang, Tai-Chang

    2014-03-01

    Spin-orbit coupling (SOC) is believed to cause the parity exchange that drives normal band insulators into the topological regime. Changing the strength of the effective SOC can also induce quantum phase transitions in materials. We performed a first-principles calculation to elucidate the quantum phase transition from a topologically trivial to nontrivial system in a 15-bilayer Sb film. We increased the k-space sampling relative to previous studies and varied the effective SOC in order to observe the changes in the bulk band gap and topological surface states. A transition from a metal to a semimetal is observed as the SOC is tuned from 0% to 100%. At a SOC value near 300%, a transition from a nontrivial topological semimetal to a topological insulator occurs. Varying the effective SOC strength can be realized experimentally by alloy substitution with elements in the same column in the periodic table. Increasing the effective SOC of the Sb film to values above 100% is a model of the Bi1-xSbx alloy, the first three-dimensional topological insulator. Further studies using this method on different systems may lead to the discovery of new topological insulators. This work is supported by the U.S. Department of Energy (Grant No. DE-FG02-07ER46383 for T-CC).

  3. Dynamics of the LTD Transition

    NASA Astrophysics Data System (ADS)

    Oran, Elaine S.

    2008-11-01

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

  4. The nature of transition blazars

    SciTech Connect

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

    2014-12-10

    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.

  5. 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...

  6. Sustainability Transitions as new perspective

    NASA Astrophysics Data System (ADS)

    Rotmans, J.

    2012-04-01

    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.

  7. Career Transitions: The Australian Experience.

    ERIC Educational Resources Information Center

    Stevens, Paul

    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…

  8. Electrical Conductivity in Transition Metals

    ERIC Educational Resources Information Center

    Talbot, Christopher; Vickneson, Kishanda

    2013-01-01

    The aim of this "Science Note" is to describe how to test the electron-sea model to determine whether it accurately predicts relative electrical conductivity for first-row transition metals. In the electron-sea model, a metal crystal is viewed as a three-dimensional array of metal cations immersed in a sea of delocalised valence…

  9. Transition metal sulfide loaded catalyst

    DOEpatents

    Maroni, Victor A.; Iton, Lennox E.; Pasterczyk, James W.; Winterer, Markus; Krause, Theodore R.

    1994-01-01

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

  10. Transition metal sulfide loaded catalyst

    DOEpatents

    Maroni, V.A.; Iton, L.E.; Pasterczyk, J.W.; Winterer, M.; Krause, T.R.

    1994-04-26

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

  11. Leadership Transitions during Fundraising Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2012-01-01

    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

  12. Parent Involvement in Transition Programs.

    ERIC Educational Resources Information Center

    McNair, Jeff; Rusch, Frank R.

    This survey of 85 parents of children with handicaps (ages 14-25) assesses the involvement of parents in the transition process of the young person from home to work or independent living, the kind of involvement they desire, and responsibilities they would be willing to assume in order to be involved. Findings show that although more than…

  13. Poland's Transition in Business Education

    ERIC Educational Resources Information Center

    Leven, Bozena

    2010-01-01

    Prior to Poland's transition from central planning to a market system, which began in 1990, schools of business were non-existent in that country. Instead, university level instruction on economics during the socialist period was closely tied to ideological priorities, and limited to imparting skills suitable for planned economy. All universities…

  14. Menopause: A Life Cycle Transition.

    ERIC Educational Resources Information Center

    Evarts, Barbara Kess; Baldwin, Cynthia

    1998-01-01

    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)

  15. The Nature of Transition Blazars

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  16. Transiting Exoplanet Survey Satellite (TESS)

    NASA Astrophysics Data System (ADS)

    Ricker, George R.; Latham, D. W.; Vanderspek, R. K.; Ennico, K. A.; Bakos, G.; Brown, T. M.; Burgasser, A. J.; Charbonneau, D.; Clampin, M.; Deming, L. D.; Doty, J. P.; Dunham, E. W.; Elliot, J. L.; Holman, M. J.; Ida, S.; Jenkins, J. M.; Jernigan, J. G.; Kawai, N.; Laughlin, G. P.; Lissauer, J. J.; Martel, F.; Sasselov, D. D.; Schingler, R. H.; Seager, S.; Torres, G.; Udry, S.; Villasenor, J. S.; Winn, J. N.; Worden, S. P.

    2009-05-01

    The Transiting Exoplanet Survey Satellite (TESS) is a low cost, SMEX-class planet finder. In a two year all-sky survey, TESS will observe more than two million bright, nearby stars, searching for temporary drops in brightness that are caused by planetary transits. Such transits not only provide the means of identifying the planet, but also provide knowledge of the planet's diameter, mass density, surface gravity, temperature, and other key properties. TESS is expected to detect more than 1000 transiting exoplanet candidates. These detections will include a sample of 100 Super Earths -- small rock-and-ice planets with masses in the range 1 to 10 Earth masses -- orbiting nearby stars with spectral types spanning a broad range, including F, G, K, and M dwarfs. No ground-based survey can achieve this feat. TESS's "wide-shallow" survey complements the "narrow-deep" Corot and Kepler mission surveys. The resulting TESS Transit Catalog of the nearest and brightest stars in the sky will constitute a unique scientific legacy for followup observations. TESS will identify Super Earths orbiting IR-bright stars, ideal for JWST searches for planetary water and carbon dioxide. The TESS mission is a collaborative effort led by researchers at the Massachusetts Institute of Technology, the Harvard-Smithsonian Center for Astrophysics, and the NASA Ames Research Center. Additional TESS partners include ATK Space Systems, the Las Cumbres Observatory Global Telescope Network, Lowell Observatory, the NASA Goddard Space Flight Center, the Infrared Processing and Analysis Center at the California Institute of Technology, the University of California (Berkeley and Santa Cruz), the SETI Institute, Espace Incorporated, the Geneva Observatory (Switzerland), the Tokyo Institute of Technology (Japan), and Institut Supérieur de l'Aéronautique et de l'Espace (France). TESS is currently completing a NASA-funded Phase A study, and is proposed for launch in December 2012.

  17. Characteristic length of glass transition

    NASA Astrophysics Data System (ADS)

    Donth, E.

    1996-03-01

    The characteristic length of the glass transition (ξ _α ) is based on the concept of cooperatively rearranging regions (CRR's) by Adam & Gibbs (1965): ξ _α is the diameter of one CRR. In the theoretical part of the talk a formula is derived how this length can be calculated from calorimetric data of the transformation interval. The approach is based on fluctuations in natural functional subsystems. The corresponding thermodynamics is represented e.g. in a book of the author (E. Donth, Relaxation and Thermodynamics in Polymers. Glass Transition, Akademie-Verlag, Berlin 1992). A typical value for this length is 3 nanometers. In the experimental part several examples are reported to enlarge the experimental evidence for such a length: Squeezing the glass transition in the amorphous layers of partially crystallized PET (C. Schick, Rostock), glass transition of small-molecule glass formers in a series of nanoscaled pores of porous glasses (F. Kremer, Leipzig), comparison with a concentration fluctuation model in homogeneous polymer mixtures (E.W. Fischer, Mainz), and, from our laboratory, backscaling to ξ _α across the main transition from the entanglement spacing in several amorphous polymers such as PVAC, PS, NR, and some polymer networks. Rouse backscaling was possible in the α β splitting region of several poly(n alkyl methacrylates) resulting in small characteristic lengths of order 1 nanometer near the onset of α cooperativity. In a speculative outlook a dynamic density pattern is presented, having a cellular structure with higher density and lower mobility of the cell walls. It will be explained, with the aid of different thermal expansion of wall and clusters, how the clusters within the cells maintain a certain mobility far below the glass temperature.

  18. Transiting Exoplanet Survey Satellite (TESS)

    NASA Astrophysics Data System (ADS)

    Ricker, George R.; Latham, D. W.; Vanderspek, R. K.; Ennico, K. A.; Bakos, G.; Brown, T. M.; Burgasser, A. J.; Charbonneau, D.; Clampin, M.; Deming, L. D.; Doty, J. P.; Dunham, E. W.; Elliot, J. L.; Holman, M. J.; Ida, S.; Jenkins, J. M.; Jernigan, J. G.; Kawai, N.; Laughlin, G. P.; Lissauer, J. J.; Martel, F.; Sasselov, D. D.; Schingler, R. H.; Seager, S.; Torres, G.; Udry, S.; Villasenor, J. N.; Winn, J. N.; Worden, S. P.

    2010-01-01

    TESS is a low-cost SMEX-class satellite mission. In a two-year all-sky survey, TESS will observe more than 2,000,000 nearby stars, searching for temporary drops in brightness caused by planetary transits. TESS is expected to identify more than 1000 transiting exoplanet candidates, including a sample of about 100 Super Earths---small rock-and-ice planets in the range 1 to 10 Earth masses---orbiting F, G, K, and M dwarfs. TESS's "wide-shallow” survey complements the "narrow-deep” CoRoT and Kepler surveys. TESS-discovered transiting systems will be nearby (< 50 pc), and typically 10-20 x brighter than those discovered by CoRoT and Kepler. Thus, the resulting TESS Transit Catalog will comprise all of the best transiting systems for follow-up observations. TESS will identify Super Earths orbiting IR-bright stars, within reach of JWST spectroscopic searches for planetary water and carbon dioxide. TESS is a collaborative effort led by researchers at the Massachusetts Institute of Technology, the Harvard-Smithsonian Center for Astrophysics, and the NASA Ames Research Center. Additional TESS scientific partners include Las Cumbres Observatory Global Telescope, Lowell Observatory, the NASA Goddard Space Flight Center, the Infrared Processing and Analysis Center at the California Institute of Technology, the Geneva Observatory (Switzerland), the Tokyo Institute of Technology (Japan), and Institut Supérieur de l'Aéronautique et de l'Espace (France). TESS was funded by NASA for a Phase A study from May 2008 - June 2009, but was not selected for flight. Additional funding leading to a flight opportunity is being sought. Support has also been provided by the Kavli Foundation, Google, and the Smithsonian Institution. TESS could launch as early as 2013-2014.

  19. Comparative Habitability of Transiting Exoplanets

    NASA Astrophysics Data System (ADS)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  20. Elements and their transitions feasible for NEET

    NASA Astrophysics Data System (ADS)

    Sakabe, S.; Takahashi, K.; Hashida, M.; Shimizu, S.; Iida, T.

    2005-09-01

    Electron and nuclear transitions in the nuclear excitation by electron transition (NEET) process have been investigated. The NEET transitions for nuclei are presented in a table in which the electron and nuclear transitions, their transition energies, transition multipoles, and nuclear spin angular momentum are given. The elements are listed for which the difference between the electron and nuclear transition energy is <5 keV, because the NEET probability will be appreciable if the electron transition energy is close to the nuclear transition one. As both the experimental and theoretical studies for NEET are at an early stage, only the elements and their parameters related to NEET are listed here. The present compilation, however, provides a useful direction for future studies of NEET and its applications to nuclear science.

  1. Understanding topological phase transition in monolayer transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    Choe, Duk-Hyun; Sung, Ha-Jun; Chang, K. J.

    2016-03-01

    Despite considerable interest in layered transition metal dichalcogenides (TMDs), such as M X2 with M =(Mo ,W ) and X =(S ,Se ,Te ) , the physical origin of their topological nature is still poorly understood. In the conventional view of topological phase transition (TPT), the nontrivial topology of electron bands in TMDs is caused by the band inversion between metal d - and chalcogen p -orbital bands where the former is pulled down below the latter. Here, we show that, in TMDs, the TPT is entirely different from the conventional speculation. In particular, M S2 and M S e2 exhibits the opposite behavior of TPT such that the chalcogen p -orbital band moves down below the metal d -orbital band. More interestingly, in M T e2 , the band inversion occurs between the metal d -orbital bands. Our findings cast doubts on the common view of TPT and provide clear guidelines for understanding the topological nature in new topological materials to be discovered.

  2. Composition of transiting and transiting-only super-Earths

    NASA Astrophysics Data System (ADS)

    Valencia, Diana

    2011-11-01

    The relatively recent detections of the first three transiting super-Earths mark the beginning of a subfield within exoplanets that is both fruitful and challenging. The first step into characterizing these objects is to infer their composition given the degenerate character of the problem. The calculations show that Kepler-10b has a composition between an Earth-like and a Mercury-like (enriched in iron) composition. In contrast, GJ 1214b is too large to be solid, and has to have a volatile envelope. Lastly, while three of the four reported mass estimates of CoRoT-7b allow for a rocky composition, one forbids it and can only be reconciled with significant amounts of water vapor. In addition to these three transiting low-mass planets, there are now more than one thousand Kepler planets with only measured radius. Even without a mass measurement (``transiting-only'') it is still possible to place constraints on the amount of volatile content of the highly-irradiated planets, as their envelopes, if present, are flared. Using Kepler-9d as an example, we estimate its water vapor, or hydrogen and helium content to be less than 50% or 0.1% by mass respectively.

  3. Transitions

    NASA Technical Reports Server (NTRS)

    2006-01-01

    26 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a variety of textures observed on a dust-covered plain in the Marte Valles region of Mars. Textural variations across the scene include: areas that are littered with small impact craters, a channel-like feature that is dominated by mounds of a variety of sizes, small ripples and/or ridges, and relatively smooth, unremarkable terrain. The contact between the cratered plain and the area dominated by mounds marks one of the banks along the edge of one of the shallow valleys of the Marte Valles system.

    Location near: 17.7oN, 175.0oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  4. Electronic transitions of palladium dimer

    SciTech Connect

    Qian, Yue; Ng, Y. W.; Chen, Zhihua; Cheung, A. S.-C.

    2013-11-21

    The laser induced fluorescence spectrum of palladium dimer (Pd{sub 2}) in the visible region between 480 and 700 nm has been observed and analyzed. The gas-phase Pd{sub 2} molecule was produced by laser ablation of palladium metal rod. Eleven vibrational bands were observed and assigned to the [17.1] {sup 3}II{sub g} - X{sup 3}Σ{sub u}{sup +} transition system. The bond length (r{sub o}) and vibrational frequency (ΔG{sub 1/2}) of the ground X{sup 3}Σ{sub u}{sup +} state were determined to be 2.47(4) Å and 211.4(5) cm{sup −1}, respectively. A molecular orbital energy level diagram was used to understand the observed ground and excited electronic states. This is the first gas-phase experimental investigation of the electronic transitions of Pd{sub 2}.

  5. Holographic Roberge-Weiss transitions

    NASA Astrophysics Data System (ADS)

    Aarts, Gert; Kumar, S. Prem; Rafferty, James

    2010-07-01

    We investigate mathcal{N} = 4 SYM coupled to fundamental flavours at nonzero imaginary quark chemical potential in the strong coupling and large N limit, using gauge/gravity duality applied to the D3-D7 system, treating flavours in the probe approximation. The interplay between {mathbb{Z}_N} symmetry and the imaginary chemical potential yields a series of first-order Roberge-Weiss transitions. An additional thermal transition separates phases where quarks are bound/ unbound into mesons. This results in a set of Roberge-Weiss endpoints: we establish that these are triple points, determine the Roberge-Weiss temperature, give the curvature of the phase boundaries and confirm that the theory is analytic in μ 2 when μ 2 ≈ 0.

  6. Weighing Protoplanets in Transitional Disks

    NASA Astrophysics Data System (ADS)

    Mulders, Gijs; Paardekooper, Sijme-Jan; Panic, Olja; Thalmann, Christian; van Boekel, Roy; Dominik, Carsten

    2013-07-01

    Forming giant planets are believed to be responsible for creating the gaps and holes in the most massive transitional disks. But the details of how these planets shape their parental disks, and how we can constrain planet properties from disk observations, remains unclear. I will present a new diagnostic for elucidating the nature of these unseen companions: the wall shape at the far end of a disk gap. Hydrodynamical simulations show that this shape depends sensitively on the embedded planet's mass and location. We focus on two transitional disks with observed candidate planetary companions, HD 100546 and LkCa 15. We have spatially resolved the disk wall in both objects, using mid-infrared interferometry and scattered light imaging, respectively. Comparing the observed wall shapes to hydrodynamical simulations, we are able to derive the masses of these embedded proto-planets.

  7. Articulated transition duct in turbomachine

    SciTech Connect

    Flanagan, James Scott; McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray

    2014-04-29

    Turbine systems are provided. A turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion and a downstream portion. The upstream portion extends from the inlet between an inlet end and an aft end. The downstream portion extends from the outlet between an outlet end and a head end. The turbine system further includes a joint coupling the aft end of the upstream portion and the head end of the downstream portion together. The joint is configured to allow movement of the upstream portion and the downstream portion relative to each other about or along at least one axis.

  8. Venus transits - A French view

    NASA Astrophysics Data System (ADS)

    Débarbat, Suzanne

    2005-04-01

    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.

  9. Phase transitions in wave turbulence.

    PubMed

    Vladimirova, Natalia; Derevyanko, Stanislav; Falkovich, Gregory

    2012-01-01

    We consider turbulence within the Gross-Pitaevsky model and look into the creation of a coherent condensate via an inverse cascade originating at small scales. The growth of the condensate leads to a spontaneous breakdown of statistical symmetries of overcondensate fluctuations: First, isotropy is broken, then a series of phase transitions marks the changing symmetry from twofold to threefold to fourfold. We describe respective anisotropic flux flows in the k space. At the highest level reached, we observe a short-range positional and long-range orientational order (as in a hexatic phase). In other words, the more one pumps the system, the more ordered the system becomes. The phase transitions happen when the system is pumped by an instability term and does not occur when pumped by a random force. We thus demonstrate nonuniversality of an inverse-cascade turbulence with respect to the nature of small-scale forcing. PMID:22400497

  10. Trust Transitivity in Social Networks

    PubMed Central

    Richters, Oliver; Peixoto, Tiago P.

    2011-01-01

    Non-centralized recommendation-based decision making is a central feature of several social and technological processes, such as market dynamics, peer-to-peer file-sharing and the web of trust of digital certification. We investigate the properties of trust propagation on networks, based on a simple metric of trust transitivity. We investigate analytically the percolation properties of trust transitivity in random networks with arbitrary in/out-degree distributions, and compare with numerical realizations. We find that the existence of a non-zero fraction of absolute trust (i.e. entirely confident trust) is a requirement for the viability of global trust propagation in large systems: The average pair-wise trust is marked by a discontinuous transition at a specific fraction of absolute trust, below which it vanishes. Furthermore, we perform an extensive analysis of the Pretty Good Privacy (PGP) web of trust, in view of the concepts introduced. We compare different scenarios of trust distribution: community- and authority-centered. We find that these scenarios lead to sharply different patterns of trust propagation, due to the segregation of authority hubs and densely-connected communities. While the authority-centered scenario is more efficient, and leads to higher average trust values, it favours weakly-connected “fringe” nodes, which are directly trusted by authorities. The community-centered scheme, on the other hand, favours nodes with intermediate in/out-degrees, in detriment of the authorities and its “fringe” peers. PMID:21483683

  11. Non-equilibrium phase transitions

    SciTech Connect

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

    1998-12-31

    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.

  12. Trust transitivity in social networks.

    PubMed

    Richters, Oliver; Peixoto, Tiago P

    2011-01-01

    Non-centralized recommendation-based decision making is a central feature of several social and technological processes, such as market dynamics, peer-to-peer file-sharing and the web of trust of digital certification. We investigate the properties of trust propagation on networks, based on a simple metric of trust transitivity. We investigate analytically the percolation properties of trust transitivity in random networks with arbitrary in/out-degree distributions, and compare with numerical realizations. We find that the existence of a non-zero fraction of absolute trust (i.e. entirely confident trust) is a requirement for the viability of global trust propagation in large systems: The average pair-wise trust is marked by a discontinuous transition at a specific fraction of absolute trust, below which it vanishes. Furthermore, we perform an extensive analysis of the Pretty Good Privacy (PGP) web of trust, in view of the concepts introduced. We compare different scenarios of trust distribution: community- and authority-centered. We find that these scenarios lead to sharply different patterns of trust propagation, due to the segregation of authority hubs and densely-connected communities. While the authority-centered scenario is more efficient, and leads to higher average trust values, it favours weakly-connected "fringe" nodes, which are directly trusted by authorities. The community-centered scheme, on the other hand, favours nodes with intermediate in/out-degrees, in detriment of the authorities and its "fringe" peers. PMID:21483683

  13. Giant Transiting Planets Observations GITPO

    NASA Astrophysics Data System (ADS)

    Afonso, C.; Henning, Th.; Weldrake, D.; Mazeh, T.; Dreizler, S.

    The search for extrasolar planets is nowadays one of the most promising science drivers in Astronomy. The radial velocity technique proved to be successful in planet hunting, harvesting more than a hundred planets to date. In these last recent years, the transit method has come to fruition, with the detection of seven Jupiter-mass extrasolar transiting planets in close-in orbits ({ AU). Currently, the radius of planets can only be determined from transiting planets, representing the principal motivation and strength of this technique. The MPIA is presently building the Large Area Imager (LAIWO) for the 1m telescope in the Wise Observatory, Israel. LAIWO will have a field of view of one square degree. An intensive search for extra-solar planets will be performed with the 1m Wise telescope, together with the 1.2m MONET telescope in Texas. We will monitor three fields at a given time during three years and more than 200 nights per year. We expect several dozens of extra-solar planets.

  14. Giant Transiting Planets Observations - GITPO

    NASA Astrophysics Data System (ADS)

    Afonso, C.

    2006-08-01

    The search for extrasolar planets is nowadays one of the most promising science drivers in Astronomy. The radial velocity technique proved to be successful in planet hunting, harvesting more than a hundred planets to date. In these last years, the transit method has come to fruition, with the detection of seven Jupiter-mass extrasolar transiting planets in close-in orbits (< 0.05 AU). Currently, the radius of planets can only be determined from transiting planets, representing the principal motivation and strength of this technique. The MPIA is presently building the Large Area Imager (LAIWO) for the 1m telescope in the Wise Observatory, Israel. LAIWO will have a field of view of one square degree. An intensive search for extra-solar planets will be performed with the 1m Wise telecope, together with the 1.2m MONET telescope in Texas. We will monitor three fields at a given time during three years and more than 200 nights per year. We expect several dozens of extra-solar planets.

  15. Critical transition in fiber suspension

    NASA Astrophysics Data System (ADS)

    Franceschini, Alexandre; Guazzelli, Elizabeth; Pine, David

    2010-03-01

    A single buoyant fiber in a low Reynolds shear flow has a fully determined motion, so-called Jeffery orbit. However, the behavior of a concentrated fiber suspension remains unclear; even slight interactions between objects can disturb the system [1]. The non-reversible motion of the fiber suspension in oscillatory flow is monitored with a) quantitative image analysis and b) measurement of the in-phase torque response. A dynamical phase transition from a quasi-reversible state to a fluctuating one is observed as the strain amplitude is increased over a threshold at which the transient time exhibits a power law divergence. We discuss here the nature of this transition and its universality class. The main features of this transition are consistent with earlier results on sphere suspensions [2, 3], such systems might be one of the few realizations of conserved directed percolation [4].[4pt] [1] Okagawa A and al, Science, Volume 181, Issue 4095, p159 (1973)[0pt] [2] Pine DJ and al, Nature, vol 438, Issue 7070, p997 (2005)[0pt] [3] Corte L and al, Nature physics, vol 4, Issue 5, p420 (2008)[0pt][4] Menon GI and al, PrE, vol 79, 061108 (2009)

  16. Saturn as a Transiting Exoplanet

    NASA Astrophysics Data System (ADS)

    Dalba, Paul A.; Muirhead, Philip S.; Fortney, Jonathan J.; Hedman, Matthew M.; Nicholson, Philip D.; Veyette, Mark J.

    2015-11-01

    Previous investigations of exoplanet atmospheres have not targeted those resembling the gas giant planets in our solar system. These types of exoplanets are too cold to be directly imaged or observed in emission, and their low transit probabilities and frequencies make characterization via transmission spectroscopy a challenging endeavor. However, studies of cold giant exoplanets would be highly valuable to our understanding of planet formation and migration and could place the gas giant members of our own solar system in a greater context. Here, we use solar occultations observed by the Visual and Infrared Mapping Spectrometer aboard the Cassini Spacecraft to extract the 1 to 5 μm transmission spectrum of Saturn, as if it were a transiting exoplanet. We detect absorption features from several molecules despite the presence of ammonia clouds. Self-consistent exoplanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce the largest feature in the spectrum. We also find that atmospheric refraction determines the minimum altitude that could be probed during mid-transit of a Saturn-twin exoplanet around a Sun-like star. These results suggest that transmission spectroscopy of cold, long-period gaseous exoplanets should be possible with current and future observatories.

  17. Functions and Requirements for the Transition Project

    SciTech Connect

    YANOCHKO, R.M.

    2000-04-24

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

  18. Polarized gravitational waves from cosmological phase transitions

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard; Kahniashvili, Tina

    2015-08-01

    We estimate the degree of circular polarization for the gravitational waves generated during the electroweak and QCD phase transitions from the kinetic and magnetic helicity generated by bubble collisions during those cosmological phase transitions.

  19. OBSERVATIONAL WINDOW FUNCTIONS IN PLANET TRANSIT SURVEYS

    SciTech Connect

    Von Braun, Kaspar; Kane, Stephen R.; Ciardi, David R. E-mail: skane@ipac.caltech.edu

    2009-09-01

    The probability that an existing planetary transit is detectable in one's data is sensitively dependent upon the window function of the observations. We quantitatively characterize and provide visualizations of the dependence of this probability as a function of orbital period upon several observing strategy and astrophysical parameters, such as length of observing run, observing cadence, length of night, transit duration and depth, and the minimum number of sampled transits. The ability to detect a transit is directly related to the intrinsic noise of the observations. In our simulations of observational window functions, we explicitly address noncorrelated (Gaussian or white) noise and correlated (red) noise and discuss how these two noise components affect transit detectability in fundamentally different manners, especially for long periods and/or small transit depths. We furthermore discuss the consequence of competing effects on transit detectability, elaborate on measures of observing strategies, and examine the projected efficiency of different transit survey scenarios with respect to certain regions of parameter space.

  20. Fast flux test facility, transition project plan

    SciTech Connect

    Guttenberg, S.

    1994-11-15

    The FFTF Transition Project Plan, Revision 1, provides changes and project baseline for the deactivation activities necessary to transition the FFTF to a radiologically and industrially safe shutdown condition.

  1. Resolution requirements for numerical simulations of transition

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  2. Site Transition Plan Guidance, December 2004

    SciTech Connect

    2004-12-01

    A short Department of Energy program document has been created to provide an outline on what the Site Transition Plan (STP) objectives are for the transition from the Office of Environmental Management to the newly established Office of Legacy Management.

  3. 42 CFR 413.239 - Transition period.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Services and Organ Procurement Costs § 413.239 Transition period. (a) Duration of transition period and..., under the ESRD prospective payment system so that the estimated total amount of payment equals...

  4. 42 CFR 413.239 - Transition period.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Services and Organ Procurement Costs § 413.239 Transition period. (a) Duration of transition period and..., under the ESRD prospective payment system so that the estimated total amount of payment equals...

  5. 42 CFR 413.239 - Transition period.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Services and Organ Procurement Costs § 413.239 Transition period. (a) Duration of transition period and..., under the ESRD prospective payment system so that the estimated total amount of payment equals...

  6. Improve Hospital-to-Home Transitions

    MedlinePlus

    ... transition from hospital to home. In the year after their discharge, those who received this transitional care had fewer hospital readmissions, hospital days, and deaths, along with a higher quality of life and greater satisfaction with their care, than those ...

  7. Microscopic Description of Nuclear Quantum Phase Transitions

    SciTech Connect

    Niksic, T.; Vretenar, D.; Lalazissis, G. A.; Ring, P.

    2007-08-31

    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.

  8. Spin reorientation transition of magnetite (001)

    NASA Astrophysics Data System (ADS)

    Martín-García, Laura; Mascaraque, Arantzazu; Pabón, Beatriz M.; Bliem, Roland; Parkinson, Gareth S.; Chen, Gong; Schmid, Andreas K.; de la Figuera, Juan

    2016-04-01

    We have imaged the rearrangement of the magnetic domains on magnetite (001) when crossing the spin reorientation transition and the Verwey transition with nanometer resolution. By means of spin-polarized low-energy electron microscopy we have monitored the change in the easy axes lowering the temperature through both transitions in remanence. The spin reorientation transition occurs in two steps: initial nucleation and growth of domains with a new surface magnetic orientation is followed by a smooth evolution.

  9. Phase Transition of Diluted Magnetic Semiconductor

    NASA Astrophysics Data System (ADS)

    Li, M. K.; Lee, S. J.; Yuldashev, S. U.; Ihm, G.; Kang, T. W.

    2011-12-01

    Three types of phase transitions in diluted magnetic semiconductor, first-order, second-order and mixed-order, are found in theory. Especially the mixed type transition shows two steps transition and novel specific heat property. Specific heat properties disclose a possible meta ferromagnetic phase confirmed by the experimental qualitative result.

  10. Managing Change and Transition, Creating a Future

    ERIC Educational Resources Information Center

    Liu, Karen

    2008-01-01

    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…

  11. Educational Policies of the Countries in Transition.

    ERIC Educational Resources Information Center

    Birzea, Cesar

    This report discusses the emergence of a new geopolitical reality, that of countries in transition. Although the expression usually refers to former Communist countries, a closer analysis shows that transition is, in fact, a universal historical phenomenon. As used here, countries in transition must evidence the following factors: (1) the…

  12. 33 CFR 401.89 - Transit refused.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Transit refused. 401.89 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not equipped in accordance with §§ 401.5...

  13. 33 CFR 401.89 - Transit refused.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Transit refused. 401.89 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not equipped in accordance with §§ 401.5...

  14. 33 CFR 401.89 - Transit refused.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Transit refused. 401.89 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not equipped in accordance with §§ 401.5...

  15. 33 CFR 401.89 - Transit refused.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Transit refused. 401.89 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not equipped in accordance with §§ 401.5...

  16. 33 CFR 401.89 - Transit refused.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Transit refused. 401.89 Section... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations General § 401.89 Transit refused. (a) An officer may refuse to allow a vessel to transit when, (1) The vessel is not equipped in accordance with §§ 401.5...

  17. On transit time instability in liquid jets

    NASA Technical Reports Server (NTRS)

    Grabitz, G.; Meier, G.

    1982-01-01

    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.

  18. A Latent Transition Model with Logistic Regression

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  19. Changes in the Transition to Adulthood.

    ERIC Educational Resources Information Center

    Winsborough, Halliman H.

    Research has shown that the transition period from a man's completion of school to first full-time job and first marriage has become shorter in recent years. The purpose of this paper is to explain part of the time reduction in this transitional period. Early in the twentieth century the transition took about 18 years because many men left school…

  20. Transition Problems and Play as Transitory Activity

    ERIC Educational Resources Information Center

    Brostrom, Stig

    2005-01-01

    Because too many children experience the transition to school as a culture shock, during the past decade teachers have implemented so-called transition activities in order to bridge the gap between preschool and school. However, transition to school also calls for a development of higher mental functions, among others the development of children's…

  1. ASD Academic Transitions: Trends in Parental Perspective

    ERIC Educational Resources Information Center

    Lee, Cindy; McCoy, Kathleen M.; Zucker, Stanley H.; Mathur, Sarup R.

    2014-01-01

    Academic transitions are a necessary and important part of an ASD student's life. Parental involvement and perspective is a vital part of each transition planning process. The primary goal of this research was to identify trends in parent perspectives regarding ASD academic transitions through meta-synthesis of current research. The research…

  2. 9 CFR 332.12 - Transition grants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Transition grants. 332.12 Section 332... CARCASSES, MEAT, AND MEAT FOOD PRODUCTS § 332.12 Transition grants. (a) Transition grants are funds that a... grant must use grant funds to reimburse the training costs of one employee per each...

  3. 9 CFR 381.522 - Transition grants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Transition grants. 381.522 Section 381... Interstate Shipment of Poultry Products § 381.522 Transition grants. (a) Transition grants are funds that a... grant must use grant funds to reimburse the training costs of one employee per each...

  4. A Smoother Transition for Black Teens

    ERIC Educational Resources Information Center

    Holcomb-McCoy, Cheryl

    2011-01-01

    For all students, the transition to high school may lead to lower academic achievement and adjustment problems. Black students are at greater risk for academic and social decline during this transition. Holcomb-McCoy identifies four obstacles that make black students more vulnerable as they navigate the transition into high school: stereotyping in…

  5. A Latent Transition Model with Logistic Regression

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  6. Lost in Transition? Student Food Consumption

    ERIC Educational Resources Information Center

    Blichfeldt, Bodil Stilling; Gram, Malene

    2013-01-01

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

  7. Lost in Transition? Student Food Consumption

    ERIC Educational Resources Information Center

    Blichfeldt, Bodil Stilling; Gram, Malene

    2013-01-01

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

  8. Evidence-Based Practices in Secondary Transition

    ERIC Educational Resources Information Center

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

    2009-01-01

    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,…

  9. Analysis of abrupt transitions in ecological systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Order-(incommensurable disorder) phase transitions

    SciTech Connect

    Kovalenko, A.; Nagaev, E.

    1982-01-05

    In first-order phase transitions in magnetic materials exhibiting a high-order spin, the short-range-order vector above the transition point may be incommensurable with the long-range-order vector below the transition point. This theoretical result explains some experiments on UAs. Some other materials which may exhibit this effect are pointed out.

  11. 9 CFR 332.12 - Transition grants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Transition grants. 332.12 Section 332... CARCASSES, MEAT, AND MEAT FOOD PRODUCTS § 332.12 Transition grants. (a) Transition grants are funds that a... grant must use grant funds to reimburse the training costs of one employee per each...

  12. 9 CFR 381.522 - Transition grants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Transition grants. 381.522 Section 381... Interstate Shipment of Poultry Products § 381.522 Transition grants. (a) Transition grants are funds that a... grant must use grant funds to reimburse the training costs of one employee per each...

  13. No Wasted Moments: Planning Purposeful Transitions

    ERIC Educational Resources Information Center

    Nicolucci, Sandra

    2010-01-01

    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…

  14. Vulnerable Youth and Transitions to Adulthood

    ERIC Educational Resources Information Center

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

    2014-01-01

    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.

  15. Family Concerns and Involvement during Kindergarten Transition

    ERIC Educational Resources Information Center

    Wildenger, Leah K.; McIntyre, Laura Lee

    2011-01-01

    The transition from preschool to formal schooling constitutes an important developmental milestone for children and their families. Very few empirical studies investigating the kindergarten transition for typically developing children have been published, and fewer have examined transition experiences from the perspective of caregivers. The aims…

  16. 42 CFR 136a.31 - Transition period.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Transition period. 136a.31 Section 136a.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a)...

  17. 42 CFR 136a.31 - Transition period.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Transition period. 136a.31 Section 136a.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES INDIAN HEALTH Transition Provisions § 136a.31 Transition period. (a)...

  18. Electrical Dissipation Measurement of Polymer Phase Transitions

    NASA Technical Reports Server (NTRS)

    Long, E. R., R; Schuszler, A., II

    1983-01-01

    Technique measures solid/solid, glass/rubber, and liquid/liquid transition temperatures in polymers having dipole moments. Technique based on change in dipole packing that occurs with each transition and measured as change in electrical dissipation factor. Change in dipole packing occuring with each transition sensed by effect on dissipation factor.

  19. Partially resolved super transition array method

    NASA Astrophysics Data System (ADS)

    Wilson, Brian G.; Iglesias, Carlos A.; Chen, Mau H.

    2015-03-01

    The partially resolved transition array model for radiative transitions between ordinary electronic configurations is extended to the super configuration approach. The specific application incorporates intermediate coupling effects into transition arrays to describe the transition from LS to JJ coupling without the ad hoc approximations introduced in past formulations. More generally, the extended concept permits stepwise refinement of the super transition array method towards the line-by-line limit in ordinary configurations. Thus, the formalism forms a framework for a hybrid scheme to combine detailed line accounting and statistical methods.

  20. Precise Photometry and Spectroscopy of Transits

    NASA Astrophysics Data System (ADS)

    Winn, J. N.

    A planetary transit produces both a photometric signal and a spectroscopic signal. Precise observations of the transit light curve reveal the planetary radius and allow a search for timing anomalies caused by satellites or additional planets. Precise measurements of the stellar Doppler shift throughout a transit (the Rossiter-McLaughlin effect) place a lower bound on the stellar obliquity, which may be indicative of the planet's migration history. I review recent results of the Transit Light Curve project, and of a parallel effort to measure the Rossiter effect for many of the known transiting planets.

  1. Electronic transitions and multiferroicity in transition metal oxides

    NASA Astrophysics Data System (ADS)

    Zhou, Haidong

    Four systems have been studied for the localized-itinerant electronic transition in transition-metal oxides: (i) In CaV1- xTixO3, substitution of Ti(IV) introduces Anderson-localized states below a mobility edge mu c that increases with x, crossing epsilon F in the range 0.2 < x< 0.4 and also transforms the strong-correlation fluctuations to localized V(IV): t1e0 configurations for x ≥ 0.1. (ii) The properties of LaTiO3+delta reveal that a hole-poor, strongly correlated electronic phase coexists with a hole-rich, itinerant-electron phase. With delta ≥ 0.03, the hole-rich phase exists as a minority phase of isolated, mobile itinerant-electron clusters embedded in the hole-poor phase. With delta ≥ 0.08, isolated hole-poor clusters are embedded in an itinerant-electron matrix. As delta > 0.08 increases, the hole-poor clusters become smaller and more isolated until they are reduced to super-paramagnetic strong-correlation fluctuations by delta = 0.12. (iii) The data of Y1-xLaxTiO 3 appears to distinguish an itinerant-electron antiferromagnetic phase in the La-rich samples from a localized-electron ferromagnetic phase with a cooperative Jahn-Teller distortion in the Y-rich phase. (iv) The transition at Tt in Mg[Ti2]O4 is a semiconductor-semiconductor transition associated with Ti-Ti dimerization instabilities. The dimerization is caused by lattice instabilities resulting from a double-well Ti-Ti bond potential at a crossover from localized to itinerant electronic behavior. RMn1-xGaxO 3 (R = Ho, Y) and Ho1-xY xMnO3 have been studied for the multiferroicity of RMnO3. Ga doping raises the ferrielectric Curie temperature TC and the Mn-spin reorientation temperature TSR while lowering TN of the Mn spins and the Ho magnetic ordering temperature T 2. The data show an important coupling between the Mn3+-ion and HO3+-ion spins as well as a TSR that is driven by a cooperative MnO5 site rotation and R 3+-ion displacements that modify the c lattice parameter. The data also support an enhanced spin-lattice interaction in the geometrically frustrated (GF) Mn-spin system. Y doping enhances the temperature region for the P6'3cm' magnetic phase and thereby increases TSR for Ho1-xY xMnO3. The studies of several oxygen non-stoichiometric Fe4+/Fe 3+ oxoperovskite show that two mechanisms, the formation of Fe 3+-O-Fe4+ pair and the disproportionation reaction 2Fe(IV)O6/2 = Fe3+ + Fe(V)O6, dominate the electronic behavior. The properties of DyBaCo2O5.5 reveal a spin-state transition from the low-spin t 6e0 ground state to higher spin-state at octahedral-site Co3+, which is also accounted for the metamagnetism in the sample.

  2. Dengue in the health transition.

    PubMed

    Halstead, S B

    1994-12-01

    The "Health Transition" describes the medical consequences which accompany the demographic transition and development. In many Asian countries, as the infectious diseases of infancy decline, such as diarrhea, acute respiratory disease, measles and malaria, so too, do infant mortality rates. As a consequence of falling infant mortality rates and declines in fertility, the age pyramid has become more rectangular. No longer is nearly half of the population under the age of 15 years. Diseases of adults are beginning to become predominant: trauma, heart disease, cancer, stroke and diabetes. Life expectancy has increased along with costs of the health care system. As a fraction of per capita gross domestic product, health care is beginning to become a major national expense. It is ironic that the one vector-borne infectious disease likely to bridge the health transition in tropical countries is dengue. As evidenced by the experience of Singapore and Taiwan, modern housing and commercial development provide more, rather than fewer breeding places for Aedes aegypti. Greater affluence often means less compliance with mosquito control programs. Meanwhile, the dengue viruses, heeding some unknown genetic imperative, cause ever more severe disease. Modern Asian societies must count dengue as a real and enduring threat. To prevent costly hospitalizations and a sense of social disorder, effective measures must be adopted to achieve a significant reduction of Aedes aegypti populations. Sustained dengue control requires source reduction which, in turn depends upon imaginative leadership, skilled man power, legislative authority, an authentic national research program and intersectoral cooperation. A leadership role beckons for new actors in the control of Aedes aegypti: large municipalities, environmental agencies and the private sector. PMID:7844846

  3. Making the transition to automation

    SciTech Connect

    Christenson, D.J. )

    1992-10-01

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

  4. Radiative transitions in metallic nanoclusters

    NASA Astrophysics Data System (ADS)

    Shalin, A. S.

    2008-02-01

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

  5. Dynamics of the deconfinement transition

    SciTech Connect

    Ananos, G.; Krein, G.; Fraga, E. S.; Mizher, A. J.

    2007-02-27

    We estimate the dissipation coefficient {gamma} that appears in Ginzburg-Landau-Langevin equations that describe phenomenologically the deconfinement transition in QCD. This is done through the implementation of Glauber dynamics of pure SU(3) lattice gauge theory. The coefficient {gamma} is extracted from the short-time exponential growth of the equal time correlation function of the order parameter. Although the absolute determination of {gamma} is ambiguous due to the difficulties in relating real time and Monte Carlo time, its relative temperature dependence can be obtained with much less arbitrariness.

  6. Transition section for acoustic waveguides

    DOEpatents

    Karplus, H.H.B.

    1975-10-28

    A means of facilitating the transmission of acoustic waves with minimal reflection between two regions having different specific acoustic impedances is described comprising a region exhibiting a constant product of cross-sectional area and specific acoustic impedance at each cross-sectional plane along the axis of the transition region. A variety of structures that exhibit this feature is disclosed, the preferred embodiment comprising a nested structure of doubly reentrant cones. This structure is useful for monitoring the operation of nuclear reactors in which random acoustic signals are generated in the course of operation.

  7. Disorder-induced depinning transition

    SciTech Connect

    Hwa, T. ); Nattermann, T. )

    1995-01-01

    The competition in the pinning of a directed polymer by a columnar pin and a background of random point impurities is investigated systematically using the renormalization-group method. With the aid of the mapping to the noisy-Burgers equation and the use of the mode-coupling method, the directed polymer is shown to be marginally localized to an arbitrary weak columnar pin in 1+1 dimensions. This weak-localization effect is attributed to the existence of large scale, nearly degenerate optimal paths of the randomly pinned directed polymer. The critical behavior of the depinning transition above 1+1 dimensions is obtained via an [epsilon] expansion.

  8. Transition splices and cost comparison

    NASA Technical Reports Server (NTRS)

    Remedios, M. D.

    1972-01-01

    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.

  9. Phase transitions in operational risk

    NASA Astrophysics Data System (ADS)

    Anand, Kartik; Kühn, Reimer

    2007-01-01

    In this paper we explore the functional correlation approach to operational risk. We consider networks with heterogeneous a priori conditional and unconditional failure probability. In the limit of sparse connectivity, self-consistent expressions for the dynamical evolution of order parameters are obtained. Under equilibrium conditions, expressions for the stationary states are also obtained. Consequences of the analytical theory developed are analyzed using phase diagrams. We find coexistence of operational and nonoperational phases, much as in liquid-gas systems. Such systems are susceptible to discontinuous phase transitions from the operational to nonoperational phase via catastrophic breakdown. We find this feature to be robust against variation of the microscopic modeling assumptions.

  10. Phase transitions in operational risk.

    PubMed

    Anand, Kartik; Kühn, Reimer

    2007-01-01

    In this paper we explore the functional correlation approach to operational risk. We consider networks with heterogeneous a priori conditional and unconditional failure probability. In the limit of sparse connectivity, self-consistent expressions for the dynamical evolution of order parameters are obtained. Under equilibrium conditions, expressions for the stationary states are also obtained. Consequences of the analytical theory developed are analyzed using phase diagrams. We find coexistence of operational and nonoperational phases, much as in liquid-gas systems. Such systems are susceptible to discontinuous phase transitions from the operational to nonoperational phase via catastrophic breakdown. We find this feature to be robust against variation of the microscopic modeling assumptions. PMID:17358228

  11. Shim for sealing transition pieces

    DOEpatents

    Lacy, Benjamin Paul; Demiroglu, Mehmet; Sarawate, Neelesh Nandkumar

    2012-07-24

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

  12. Dynamics of the deconfinement transition

    NASA Astrophysics Data System (ADS)

    Ananos, G.; Fraga, E. S.; Krein, G.; Mizher, A. J.

    2007-02-01

    We estimate the dissipation coefficient ? that appears in Ginzburg-Landau-Langevin equations that describe phenomenologically the deconfinement transition in QCD. This is done through the implementation of Glauber dynamics of pure SU(3) lattice gauge theory. The coefficient ? is extracted from the short-time exponential growth of the equal time correlation function of the order parameter. Although the absolute determination of ? is ambiguous due to the difficulties in relating real time and Monte Carlo time, its relative temperature dependence can be obtained with much less arbitrariness.

  13. Conformational Transitions in Molecular Systems

    NASA Astrophysics Data System (ADS)

    Bachmann, M.; Janke, W.

    2008-11-01

    Proteins are the "work horses" in biological systems. In almost all functions specific proteins are involved. They control molecular transport processes, stabilize the cell structure, enzymatically catalyze chemical reactions; others act as molecular motors in the complex machinery of molecular synthetization processes. Due to their significance, misfolds and malfunctions of proteins typically entail disastrous diseases, such as Alzheimer's disease and bovine spongiform encephalopathy (BSE). Therefore, the understanding of the trinity of amino acid composition, geometric structure, and biological function is one of the most essential challenges for the natural sciences. Here, we glance at conformational transitions accompanying the structure formation in protein folding processes.

  14. Low floor mass transit vehicle

    DOEpatents

    Emmons, J. Bruce; Blessing, Leonard J.

    2004-02-03

    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.

  15. The Amazon basin in transition.

    PubMed

    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

    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

  16. TERMS PHOTOMETRY OF KNOWN TRANSITING EXOPLANETS

    SciTech Connect

    Dragomir, Diana; Kane, Stephen R.; Ciardi, David R.; Gelino, Dawn M.; Payne, Alan; Ramirez, Solange V.; Von Braun, Kaspar; Wyatt, Pamela; Pilyavsky, Genady; Mahadevan, Suvrath; Wright, Jason T.; Zachary Gazak, J.; Rabus, Markus

    2011-10-15

    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.

  17. Energy Landscape of Zirconia Phase Transitions.

    PubMed

    Guan, Shu-Hui; Zhang, Xiao-Jie; Liu, Zhi-Pan

    2015-07-01

    The solid-phase transitions of zirconia are important phenomena for many industrial applications. Because of the lack of tools for resolving the atom displacement pattern, the transition kinetics has been disputed for over 60 years. Here, first-principles-based stochastic surface walking (SSW) pathway sampling is utilized for resolving the mechanism of ZrO2 tetragonal-to-monoclinic solid-phase transition. Two types of lattice and atom correspondence allowed in phase transition are determined for the first time from energy criterion, which are originated from two nearly energy-degenerate lowest-transition pathways and one stress-induced ferroelastic transition channel of tetragonal phase. An orthorhombic crystal phase (Pbc2/1) is discovered to be a trapping state at low temperatures in phase transition, the presence of which does not create new orientation relation but deters transformation toughening significantly. This new finding may facilitate the design of new functional oxide materials in ceramic industry. PMID:26075311

  18. Theoretical X-ray production cross sections at incident photon energies across Li (i=1-3) absorption edges of Br

    NASA Astrophysics Data System (ADS)

    Puri, Sanjiv

    2015-08-01

    The X-ray production (XRP) cross sections, σLk (k = l, η, α, β6, β1, β3, β4, β9,10, γ1,5, γ2,3) have been evaluated at incident photon energies across the Li(i=1-3) absorption edge energies of 35Br using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell the X-ray emission rates based on the Dirac-Fock (DF) model, the fluorescence and Coster Kronig yields based on the Dirac-Hartree-Slater (DHS) model, and two sets of the photoionisation cross sections based on the relativistic Hartree-Fock-Slater (RHFS) model and the Dirac-Fock (DF) model, in order to highlight the importance of electron exchange effects at photon energies in vicinity of absorption edge energies.

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

    SciTech Connect

    Chauhan, Yogeshwar; Kumar, Anil; Puri, Sanjiv

    2009-07-15

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

  20. X-ray production cross sections at incident photon energies across the Mi (i=1-5) edges of 90Th

    NASA Astrophysics Data System (ADS)

    Kaur, Rajnish; Shehla, Kumar, Anil; Puri, Sanjiv

    2015-08-01

    The X-ray production cross sections for the Mk (k= ξ, δ, α, β, ζ, γ, m1, m2) groups of X-rays have been evaluated at incident photon energies across the Mi (i =1-5) edges of 90Th using the relativistic Hartree-Fock-Slater model based photoionisation cross sections and recently reported values of the M-shell X-ray emission rates, fluorescence and Coster Kronig yields. Further, the energies of the prominent (Mi-Sj) (Sj=Nj, Oj and i =1-3, j =1-7) resonant Raman scattered (RRS) peaks at different incident photon energies have also been evaluated using the neutral-atom electron binding energies (Esj) based on the relaxed orbital relativistic Hartree-Fock-Slater model.

  1. Multiple electron emission from noble gases colliding with proton beams, including postcollisional effects

    NASA Astrophysics Data System (ADS)

    Galassi, M. E.; Rivarola, R. D.; Fainstein, P. D.

    2007-05-01

    The process of multiple electron ionization of Ne and Ar noble gases produced by impact of proton beams is studied in the framework of the independent-electron model. The role played by different mechanisms is analyzed, including intershell Auger and intrashell Coster-Kronig electron emission, which follow the production of vacancies due to direct interaction of the projectile with the target electrons. The present results, obtained with the continuum distorted wave eikonal initial state (CDW-EIS) approximation, confirm previous predictions given by a different theoretical model. Semiempirical approximations are introduced by using analytical single-ionization probabilities with adjustable parameters determined from CDW-EIS total cross sections. The small computational time required to calculate multiple ionization cross sections with these semiempirical approximations and the good agreement found with existing experimental data and with results obtained with more elaborated theoretical models make them good candidates to study electron emission from complex targets.

  2. Double ionization of atomic cadmium

    SciTech Connect

    Linusson, P.; Fritzsche, S.; Eland, J. H. D.; Hedin, L.; Karlsson, L.; Feifel, R.

    2011-02-15

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

  3. Effect of wave function on the proton induced L XRP cross sections for 62Sm and 74W

    NASA Astrophysics Data System (ADS)

    Shehla, Kaur, Rajnish; Kumar, Anil; Puri, Sanjiv

    2015-08-01

    The Lk(k= 1, α, β, γ) X-ray production cross sections have been calculated for 74W and 62Sm at different incident proton energies ranging 1-5 MeV using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell X-ray emission rates based on the Dirac-Fork (DF) model, the fluorescence and Coster Kronig yields based on the Dirac- Hartree-Slater (DHS) model and two sets the proton ionization cross sections based on the DHS model and the ECPSSR in order to assess the influence of the wave function on the XRP cross sections. The calculated cross sections have been compared with the measured cross sections reported in the recent compilation to check the reliability of the calculated values.

  4. PIXE-INP computer code for PIXE analyses of thin and thick samples

    NASA Astrophysics Data System (ADS)

    Havránek, V.; Hnatowicz, V.; Kvítek, J.; Obrusník, I.

    1994-03-01

    The Pascal 6.0 program package PIXE-INP was developed at Institute of Nuclear Physics (Academy of Sciences of Czech Republic) for quantitative evaluation of PIXE spectra from thin and thick samples. The K-, L- and M-sensitivities are calculated using semi-empirical and theoretical ionization cross sections, tabulated relative X-ray emission probabilities, Coster-Kronig and fluorescence yields. The X-ray detector efficiency is determined by measuring a set of thin standards with known element content. The package is supplemented with the data bases on X-ray attenuation coefficients and proton stopping powers which are needed for the calculation of thick sample matrix corrections. The X-ray spectrum evaluation comprises an iterative background removal and non-linear least squares fitting of X-ray multiplets with Gaussian peak shape. The escape and summation peaks are taken into account. The performance of the program package is documented on measurements of reference materials.

  5. Nutrition transition and food sustainability.

    PubMed

    Belahsen, Rekia

    2014-08-01

    The aim of the present paper is to review nutrition transition (NT) ongoing in low and middle income countries and the associated dietary changes. NT is accompanied by demographic and epidemiological transition associated with economic development and urbanisation. In these countries, while the problems of hunger and undernourishment persist, there is an escalation of diet-related non-communicable diseases; making them face both problems of malnutrition, under and overnutrition. Indeed, in addition to protein energy malnutrition underweight and micronutrient deficiencies affect a high proportion of children and women. Conversely, changes in dietary habits and physical activity patterns have led to emergence of chronic diseases such as obesity, diabetes, hypertension, stroke, hyperlipidaemia, CHD and cancer. One possible explanation of weight gain and its associated health consequences is the trend of the consumption of already prepared meals and the restaurants that are in continuous development leading to high consumption of foods rich in sugar and fat. The health problems associated with NT have not spared populations in the Mediterranean area where the type of diet is reported to be healthy and to protect against cardiovascular risks. This is seen in North Africa that belongs also to the Mediterranean basin, where the nutritional situation raises the problem of traditional foods sustainability. Accurate nutritional policy and education are needed to redress the effects of malnutrition related to NT on health. PMID:24824339

  6. Statistical theory of nonadiabatic transitions.

    PubMed

    Neufeld, A A

    2005-04-22

    Based on results of the preceding paper, and assuming fast equilibration in phase space to the temperature of the surrounding media compared to the time scale of a reaction, we formulate a statistical theory of intramolecular nonadiabatic transitions. A classical mechanics description of phase space dynamics allows for an ab initio treatment of multidimensional reaction coordinates and easy combination with any standard molecular dynamics (MD) method. The presented approach has several features that distinguishes it from existing methodologies. First, the applicability limits of the approach are well defined. Second, the nonadiabatic transitions are treated dynamically, with full account of detailed balance, including zero-point energy, quantum coherence effects, arbitrarily long memory, and change of the free energy of the bath. Compared to popular trajectory surface hopping schemes, our MD-based algorithm is more efficient computationally, and does not use artificial ad hoc constructions like a "fewest switching" algorithm, and rescaling of velocities to conserve total energy. The enhanced capabilities of the new method are demonstrated considering a model of two coupled harmonic oscillators. We show that in the rate regime and at moderate friction the approach precisely reproduces the free-energy-gap law. It also predicts a general trend of the reaction dynamics in the low friction limit, and is valid beyond the rate regime. PMID:15945676

  7. Dynamic transition in supercritical iron.

    PubMed

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

    2014-01-01

    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

  8. Synfuels and the energy transition

    NASA Astrophysics Data System (ADS)

    Balzhiser, R. E.

    1981-08-01

    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.

  9. Quantum transitions between classical histories

    NASA Astrophysics Data System (ADS)

    Hartle, James; Hertog, Thomas

    2015-09-01

    In a quantum theory of gravity spacetime behaves classically when quantum probabilities are high for histories of geometry and field that are correlated in time by the Einstein equation. Probabilities follow from the quantum state. This quantum perspective on classicality has important implications. (a) Classical histories are generally available only in limited patches of the configuration space on which the state lives. (b) In a given patch, states generally predict relative probabilities for an ensemble of possible classical histories. (c) In between patches classical predictability breaks down and is replaced by quantum evolution connecting classical histories in different patches. (d) Classical predictability can break down on scales well below the Planck scale, and with no breakdown in the classical equations of motion. We support and illustrate (a)-(d) by calculating the quantum transition across the de Sitter-like throat connecting asymptotically classical, inflating histories in the no-boundary quantum state. This supplies probabilities for how a classical history on one side transitions and branches into a range of classical histories on the opposite side. We also comment on the implications of (a)-(d) for the dynamics of black holes and eternal inflation.

  10. Preterm birth: Transition to adulthood.

    PubMed

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

    2010-01-01

    Preterm birth is associated with greater difficulty with transitions from childhood to adolescence to adulthood. Adolescents and young adults born preterm have higher rates of cerebral palsy, intellectual disability, cognitive impairment, learning disability, executive dysfunction, attention deficit disorder, and social-emotional difficulties than their peers born fullterm. Compared to individuals born fullterm, more preterm survivors have major neurodevelopmental or psychiatric disability and need financial supports and societal resources. Neuroimaging studies of adolescents and adults born preterm report higher rates of brain injury, differences in regional brain structure, and different brain circuits than in those born fullterm. Making the transition to adulthood is more difficult for young adults who were born preterm than their peers born fullterm, in that fewer complete high school and higher education, find and keep meaningful employment, and live independently from their parents. As a group, they do not tend to be risk-takers, and they have lower rates of alcohol abuse, use of illicit drugs, and criminal offenses than do their peers. Despite their many challenges, the majority of adults born preterm function well, form personal relationships, integrate well into their community, and are as satisfied with their quality of life as are their peers. Concerns regarding current preterm infants, with more extremely preterm survivors, overwhelming our medical, educational, and societal resources should serve as an impetus for research on prevention of preterm births and brain injury, as well as how to support and promote their ongoing neuromaturation and recovery from injury. PMID:25708075

  11. Transitional nuclei near shell closures

    SciTech Connect

    Mukherjee, G.

    2014-08-14

    High spin states in Bismuth and Thallium nuclei near the Z = 82 shell closure and Cesium nuclei near the N = 82 shell closure in A = 190 and A = 130 regions, respectively, have been experimentally investigated using heavy-ion fusion evaporation reaction and by detecting the gamma rays using the Indian National Gamma Array (INGA). Interesting shape properties in these transitional nuclei have been observed. The results were compared with the neighboring nuclei in these two regions. The total Routhian surface (TRS) calculations have been performed for a better understanding of the observed properties. In mass region A = 190, a change in shape from spherical to deformed has been observd around neutron number N = 112 for the Bi (Z = 83) isotopes with proton number above the magic gap Z = 82, whereas, the shape of Tl (Z = 81) isotopes with proton number below the magic gap Z = 82 remains stable as a function of neutron number. An important transition from aplanar to planar configuration of angular momentum vectors leading to the occurance of nuclar chirality and magnetic rotation, respectively, has been proposed for the unique parity πh{sub 11/2}⊗νh{sub 11/2} configuration in Cs isotopes in the mass region A ∼ 130 around neutron number N = 79. These results are in commensurate with the TRS calculations.

  12. Elaborating transition interface sampling methods

    SciTech Connect

    Erp, Titus S. van . E-mail: bolhuis@science.uva.nl

    2005-05-01

    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.

  13. Dynamic transition in supercritical iron

    PubMed Central

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

    2014-01-01

    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

  14. STELLAR TRANSITS IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Beky, Bence; Kocsis, Bence E-mail: bkocsis@cfa.harvard.edu

    2013-01-01

    Supermassive black holes (SMBHs) are typically surrounded by a dense stellar population in galactic nuclei. Stars crossing the line of site in active galactic nuclei (AGNs) produce a characteristic transit light curve, just like extrasolar planets do when they transit their host star. We examine the possibility of finding such AGN transits in deep optical, UV, and X-ray surveys. We calculate transit light curves using the Novikov-Thorne thin accretion disk model, including general relativistic effects. Based on the expected properties of stellar cusps, we find that around 10{sup 6} solar mass SMBHs, transits of red giants are most common for stars on close orbits with transit durations of a few weeks and orbital periods of a few years. We find that detecting AGN transits requires repeated observations of thousands of low-mass AGNs to 1% photometric accuracy in optical, or {approx}10% in UV bands or soft X-ray. It may be possible to identify stellar transits in the Pan-STARRS and LSST optical and the eROSITA X-ray surveys. Such observations could be used to constrain black hole mass, spin, inclination, and accretion rate. Transit rates and durations could give valuable information on the circumnuclear stellar clusters as well. Transit light curves could be used to image accretion disks with unprecedented resolution, allowing us to resolve the SMBH silhouette in distant AGNs.

  15. THE QUASIPERIODIC AUTOMATED TRANSIT SEARCH ALGORITHM

    SciTech Connect

    Carter, Joshua A.; Agol, Eric

    2013-03-10

    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.

  16. Research on Methods of Processing Transit IC Card Information and Constructing Transit OD Matrix

    NASA Astrophysics Data System (ADS)

    Han, Xiuhua; Li, Jin; Peng, Han

    Transit OD matrix is of vital importance when planning urban transit system. Traditional transit OD matrix constructing method needs a large range of spot check survey. It is expensive and needs long cycle time to process information. Recently transit IC card charging systems have been widely applied in big cities. Being processed reasonably, transit passenger information stored in IC card database can turn into information resource. It will reduce survey cost a lot. The concept of transit trip chain is put forward in this paper. According to the characteristics of closed transit trip chain, it discusses how to process IC card information and construct transit OD matrix. It also points out that urban transit information platform and data warehouse should be constructed, and how to integrate IC card information.

  17. Main ring transition crossing simulations

    SciTech Connect

    Kourbanis, I.; Ng, King-Yuen.

    1990-10-01

    We used ESME to simulate transition crossing in the Main Ring (MR). For the simulations, we followed the MR 29 cycle used currently for {bar p} production with a flat top of 120 GeV. In Sect. II, some inputs are discussed. In Sect. III, we present simulations with space charge turned off so that the effect of nonlinearity can be studied independently. When space charge is turned on in Sect. IV, we are faced with the problem of statistical errors due to binning, an analysis of which is given in the Appendices. Finally in Sects. V and VI, the results of simulations with space charge are presented and compared with the experimental measurements. 7 refs., 6 figs.

  18. Brain Performance versus Phase Transitions

    PubMed Central

    Torres, Joaquín J.; Marro, J.

    2015-01-01

    We here illustrate how a well-founded study of the brain may originate in assuming analogies with phase-transition phenomena. Analyzing to what extent a weak signal endures in noisy environments, we identify the underlying mechanisms, and it results a description of how the excitability associated to (non-equilibrium) phase changes and criticality optimizes the processing of the signal. Our setting is a network of integrate-and-fire nodes in which connections are heterogeneous with rapid time-varying intensities mimicking fatigue and potentiation. Emergence then becomes quite robust against wiring topology modification—in fact, we considered from a fully connected network to the Homo sapiens connectome—showing the essential role of synaptic flickering on computations. We also suggest how to experimentally disclose significant changes during actual brain operation. PMID:26193453

  19. Perpetual transitions in Romanian healthcare.

    PubMed

    Spiru, Luiza; Traşcu, Răzvan Ioan; Turcu, Ileana; Mărzan, Mircea

    2011-12-01

    Although Romania has a long-lasting tradition in organized medical healthcare, in the last two decades the Romanian healthcare system has been undergoing a perpetual transition with negative effects on all parties involved. The lack of long-term strategic vision, the implementation of initiatives without any impact studies, hence the constant short-term approach from the policy makers, combined with the "inherited" low allocation from GDP to the healthcare system have contributed significantly to its current evolution. Currently, most measures taken are of the "fire-fighting" type, rather than looking to the broader, long time perspective. There should be no wonder then, that predictive and preventive services do not get the proper attention and support. Patient and physicians should step in and take action in regulating a system that was originally designed for them. But until this happens, the organizations with leadership skills and vision need to take action-and this has already started. PMID:23199172

  20. Approximating metal-insulator transitions

    NASA Astrophysics Data System (ADS)

    Danieli, Carlo; Rayanov, Kristian; Pavlov, Boris; Martin, Gaven; Flach, Sergej

    2015-12-01

    We consider quantum wave propagation in one-dimensional quasiperiodic lattices. We propose an iterative construction of quasiperiodic potentials from sequences of potentials with increasing spatial period. At each finite iteration step, the eigenstates reflect the properties of the limiting quasiperiodic potential properties up to a controlled maximum system size. We then observe approximate Metal-Insulator Transitions (MIT) at the finite iteration steps. We also report evidence on mobility edges, which are at variance to the celebrated Aubry-André model. The dynamics near the MIT shows a critical slowing down of the ballistic group velocity in the metallic phase, similar to the divergence of the localization length in the insulating phase.

  1. Synthesis of transition metal carbonitrides

    DOEpatents

    Munir, Zuhair A. R.; Eslamloo-Grami, Maryam

    1994-01-01

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

  2. Dynamical transitions of turing patterns.

    SciTech Connect

    Kaper, H. G.; Wang, S.; Yari, M.; Mathematics and Computer Science; Indiana Univ.

    2009-01-01

    This paper is concerned with the formation and persistence of spatiotemporal patterns in binary mixtures of chemically reacting species, where one of the species is an activator, the other an inhibitor of the chemical reaction. The system of reaction-diffusion equations is reduced to a finite system of ordinary differential equations by a variant of the centre-manifold reduction method. The reduced system fully describes the local dynamics of the original system near transition points at the onset of instability. The attractor-bifurcation theory is used to give a complete characterization of the bifurcated objects in terms of the physical parameters of the problem. The results are illustrated for the Schnakenberg model.

  3. The transition to a sustainable society.

    PubMed Central

    Speth, J G

    1992-01-01

    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

  4. Dynamical transitions in peak elevator traffic

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2004-02-01

    We study the dynamical phase transitions in the elevator traffic during the morning peak period. We apply the coupled nonlinear map model to the dynamics of M elevators. We investigate the effect of elevator's number M on the dynamical transition. It is shown that the dynamical transitions occur at two stages. The first transition occurs when an elevator carries the full load of passengers. Then, the second transition occurs if all the elevators carry the full load of passengers. The number of riding passengers fluctuates with varying trips. This is due to the deterministic chaos. The motions of elevators depend on the loading parameter, the maximum capacity of an elevator, and the number of elevators. The dependence of the first and second transition points on the elevator's number M is shown.

  5. Aggregation Transitions in Flexible Homopolymer Systems

    NASA Astrophysics Data System (ADS)

    Koci, Tomas; Bachmann, Michael; Soft Matter Systems Research Group Team

    2015-03-01

    Ubiquitous in biological systems, aggregation transitions are the key towards understanding a multitude of topics such as the amyloid sheet formation and prionic disease. By means of extensive replica-exchange Monte Carlo simulations of a generic coarse-grained model we examine systems consisting of up to 20 individual polymer chains. The application of powerful microcanonical analysis methods reveals new details about the anatomy of aggregation transitions that were previously inaccessible via conventional canonical analysis. We find evidence for phase separation in the transition region and classify the transition as first order. Finally we show that the aggregation transition consists of a hierarchy of sub-phase transitions and discuss the implications of this finding.

  6. Filling transitions in acute and open wedges.

    PubMed

    Malijevsk, Alexandr; Parry, Andrew O

    2015-05-01

    We present numerical studies of first-order and continuous filling transitions in wedges of arbitrary opening angle ?, using a microscopic fundamental measure density functional model with short-ranged fluid-fluid forces and long-ranged wall-fluid forces. In this system the wetting transition characteristic of the planar wall-fluid interface is always first order regardless of the strength of the wall-fluid potential ?(w). In the wedge geometry, however, the order of the filling transition depends not only on ?(w) but also on the opening angle ?. In particular we show that even if the wetting transition is strongly first order the filling transition is continuous for sufficient acute wedges. We show further that the change in the order of the transition occurs via a tricritical point as opposed to a critical end point. These results extend previous effective Hamiltonian predictions which were limited only to shallow wedges. PMID:26066177

  7. More holographic Berezinskii-Kosterlitz-Thouless transitions

    SciTech Connect

    Jensen, Kristan

    2010-08-15

    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.

  8. Wetting, multilayer adsorption, and interface phase transitions

    NASA Technical Reports Server (NTRS)

    Moldover, M. R.; Schmidt, J. W.

    1984-01-01

    When two fluid phases coexist near their mutual critical point, one fluid phase forms a layer which intrudes between the other fluid phase and any third phase that happens to be present. As the two fluid phases are taken away from their critical point, a phase transition often occurs such that the intruding layer vanishes. Recent evidence is presented that the transition from the complete wetting (intruding layer) configuration to the incomplete wetting (three-phase contact) configuration is a first-order phase transition. The thickness of the intruding layers has been measured for diverse systems. These data are not fully understood. The intruding layers are extreme examples of multilayer adsorption. Certain theories predict that a 'prewetting' transition from high adsorption to low adsorption is associated with the transition from complete wetting to incomplete wetting. Present search for this transition is inconclusive.

  9. Picking the right transition strategy.

    PubMed

    Watkins, Michael D

    2009-01-01

    Leaders in transition reflexively rely on the skills and strategies that worked for them in the past. That's a mistake, says Watkins, whose research shows that executives moving into new roles must gain a deep understanding of the situation at hand and adapt to it. To help them accurately assess their organizations and tailor their strategies and styles accordingly, he developed the STARS framework. "STARS" is an acronym for the five common situations leaders move into: start-up, turnaround, accelerated growth, realignment, and sustaining success. Thus, the model outlines the challenges of launching a venture or project; saving a business or initiative that's in serious trouble; dealing with rapid expansion; reenergizing a once-leading company that's now facing problems; and following in the footsteps of a highly regarded leader with a strong legacy of success. Executives can accelerate their immersion in new roles by following certain fundamental principles: Organize to learn about the business, establish A-item priorities, define strategic intent, quickly build the leadership team, secure early wins, and create supportive alliances across the company. But the way those principles should be applied depends very much on the business situation, which the STARS framework can help leaders analyze. Turnarounds and realignments present especially distinct leadership challenges that call for particular transition strategies. Regardless of the business situation, leaders must figure out which things need to happen--perhaps a jump in market share or an expansion into different markets--for their business to achieve its goals. And they must determine which leadership style best fits the new culture they're joining. Armed with such clarity, executives can design effective plans to manage their organizations and themselves. PMID:19227407

  10. Analysis of Nuclear Quantum Phase Transitions

    SciTech Connect

    Li, Z. P.; Meng, J.; Niksic, T.; Vretenar, D.; Lalazissis, G. A.; Ring, P.

    2009-08-26

    A microscopic analysis, based on nuclear energy density functionals, is presented for shape phase transitions in Nd isotopes. Low-lying excitation spectra and transition probabilities are calculated starting from a five-dimensional Hamiltonian, with parameters determined by constrained relativistic mean-field calculations for triaxial shapes. The results reproduce available data, and show that there is an abrupt change of structure at N = 90, that corresponds to a first-order quantum phase transition between spherical and axially deformed shapes.

  11. Observation of transitions in lithiumlike germanium

    NASA Technical Reports Server (NTRS)

    Behring, W. E.; Seely, J. F.; Brown, C. M.; Feldman, U.; Knauer, J. P.

    1989-01-01

    Transitions of the type n = 2-2, n = 2-3 and n = 3-4 in Li-like Ge(29+) have been observed in the spectrum from a laser-produced plasma. The energy levels and ionization energy of Ge(29+) were derived from the observed wavelengths. The wavelength of the 2s 2S1/2-2p 2P3/2 transition is sufficiently accurate to determine the quantum-electrodynamic contribution to the transition energy.

  12. Fine structure and resonance transitions in C(+)

    NASA Technical Reports Server (NTRS)

    Blum, Robert D.; Pradhan, Anil K.

    1991-01-01

    Significant features in the collision strengths for electron-impact excitation of the fine-structure transition 2P0 1/2 - 2P0 3/2 and the resonance transition 2P0 - 2D in C(+) are discussed based on improved calculations. The former transition gives rise to a well-known (2,3) line in the infrared spectra of many astrophysical sources.

  13. The Demographic Transition: Causes and Consequences

    PubMed Central

    Galor, Oded

    2013-01-01

    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

  14. Nonadiabatic transitions in electrostatically trapped ammonia molecules

    SciTech Connect

    Kirste, Moritz; Schnell, Melanie; Meijer, Gerard; Sartakov, Boris G.

    2009-05-15

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

  15. Continuous, Multielement, Hot-Film Transition Gage

    NASA Technical Reports Server (NTRS)

    Holmes, B.; Mcpherson, J.; Harris, F.; Diamond, J.; Johnson, N.; Chapman, J.

    1986-01-01

    Accurate measurement of location where laminar boundary layer undergoes transition to turbulent one serves many purposes in basic aero-dynamic research and developmental testing. Individual gages must be staggered to prevent formation of turbulence at gages downstream. This arrangement precludes accurate measurements of laminar/turbulent transition regions along streamline. Complete understanding of performance, stability, and control of laminar-flow airplane requires knowledge of transition locations on wing surface, empennage surfaces, fuselage, and nacelles. Visual, acoustic, and electronic methods capable of providing this transition information.

  16. Negative refraction using Raman transitions and chirality

    NASA Astrophysics Data System (ADS)

    Sikes, D. E.; Yavuz, D. D.

    2011-11-01

    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.

  17. Dynamics of stimulated L → H transitions

    SciTech Connect

    Miki, K.; Center for Computational Science and e-Systems, Japan Atomic Energy Agency, Chiba 277-8587 ; Diamond, P. H.; Xiao, W. W.; Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 ; Hahn, S.-H.; Gürcan, Ö. D.; Tynan, G. R.

    2013-08-15

    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.

  18. Relative Transition Probabilities of Rare Gases

    NASA Astrophysics Data System (ADS)

    Delanis, Daniel; Duncan-Chamberlin, Katherine; Piracha, Naveed

    2011-04-01

    We have measured relative transition probabilities for emissions from the noble gasses using hollow cathode lamps. Relative transition probabilities are reported for thirty lines from Ne I, twenty-four lines from Ar I, fourteen lines from Kr I, and twenty-one lines from Xe I. All transitions discussed are from the 2p level to 1s levels. Uncertainty has been measured and found to be within 5%. This data can be applied to calibrate the relative detection efficiency of a spectrometer over a range of 4000 å--10000 å. Comparisons between the relative transition probabilities of each species is discussed.

  19. Negative refraction using Raman transitions and chirality

    SciTech Connect

    Sikes, D. E.; Yavuz, D. D.

    2011-11-15

    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.

  20. Observations of Extrasolar Planet Transits: What's next?

    NASA Astrophysics Data System (ADS)

    Rauer, H.

    2014-03-01

    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.

  1. Kepler Stars with Multiple Transiting Planet Candidates

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2012-01-01

    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.

  2. The L- to T-dwarf transition

    SciTech Connect

    Marley, M. S.; Cushing, M. C.; Saumon, D.

    2004-01-01

    While the precise mechanism responsible for the L to T dwarf transition remains unclear, it is clearly caused by changing cloud characteristics. Here we briefly review data relevant to understanding the nature of the transition and argue that changing atmospheric dynamics produce the transition by opening holes through the global iron and silicate cloud decks. Other possibilities, such as a sudden vertical collapse in these cloud decks are also considered. Any acceptable model of the L to T transition must ultimately connect changing cloud properties to the underlying atmospheric dynamics.

  3. NO TRANSIT TIMING VARIATIONS IN WASP-4

    SciTech Connect

    Petrucci, R.; Schwartz, M.; Buccino, A. P.; Mauas, P. J. D.; Jofré, E.; Cúneo, V.; Gómez, M.; Martínez, C.

    2013-12-20

    We present six new transits of the system WASP-4. Together with 28 light curves published in the literature, we perform a homogeneous study of its parameters and search for variations in the transits' central times. The final values agree with those previously reported, except for a slightly lower inclination. We find no significant long-term variations in i or R{sub P} /R {sub *}. The O-C mid-transit times do not show signs of transit timing variations greater than 54 s.

  4. The Helix Coil Transition of DNA

    ERIC Educational Resources Information Center

    Steinert, Roger; Hudson, Bruce

    1973-01-01

    This transition, observed with an inexpensive ultraviolet photometer, is a potentially useful experiment for an advanced freshman class because it introduces several concepts of general physical interest. (DF)

  5. X-Ray Transition Energies Database

    National Institute of Standards and Technology Data Gateway

    SRD 128 X-Ray Transition Energies Database (Web, free access)   This X-ray transition table provides the energies and wavelengths for the K and L transitions connecting energy levels having principal quantum numbers n = 1, 2, 3, and 4. The elements covered include Z = 10, neon to Z = 100, fermium. There are two unique features of this data base: (1) a serious attempt to have all experimental values on a scale consistent with the International System of measurement (the SI) and (2) inclusion of accurate theoretical estimates for all transitions.

  6. Glowing Hot Transiting Exoplanet Discovered

    NASA Astrophysics Data System (ADS)

    2003-04-01

    VLT Spectra Indicate Shortest-Known-Period Planet Orbiting OGLE-TR-3 Summary More than 100 exoplanets in orbit around stars other than the Sun have been found so far. But while their orbital periods and distances from their central stars are well known, their true masses cannot be determined with certainty, only lower limits. This fundamental limitation is inherent in the common observational method to discover exoplanets - the measurements of small and regular changes in the central star's velocity, caused by the planet's gravitational pull as it orbits the star. However, in two cases so far, it has been found that the exoplanet's orbit happens to be positioned in such a way that the planet moves in front of the stellar disk, as seen from the Earth. This "transit" event causes a small and temporary dip in the star's brightness, as the planet covers a small part of its surface, which can be observed. The additional knowledge of the spatial orientation of the planetary orbit then permits a direct determination of the planet's true mass. Now, a group of German astronomers [1] have found a third star in which a planet, somewhat larger than Jupiter, but only half as massive, moves in front of the central star every 28.5 hours . The crucial observation of this solar-type star, designated OGLE-TR-3 [2] was made with the high-dispersion UVES spectrograph on the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). It is the exoplanet with the shortest period found so far and it is very close to the star, only 3.5 million km away. The hemisphere that faces the star must be extremely hot, about 2000 °C and the planet is obviously losing its atmosphere at high rate . PR Photo 10a/03 : The star OGLE-TR-3 . PR Photo 10b/03 : VLT UVES spectrum of OGLE-TR-3. PR Photo 10c/03 : Relation between stellar brightness and velocity (diagram). PR Photo 10d/03 : Observed velocity variation of OGLE-TR-3. PR Photo 10e/03 : Observed brightness variation of OGLE-TR-3. The search for exoplanets More than 100 planets in orbit around stars other than the Sun have been found so far. These "exoplanets" come in many different sizes and they move in a great variety of orbits at different distances from their central star, some nearly round and others quite elongated. Some planets are five to ten times more massive than the largest one in the solar system, Jupiter - the lightest exoplanets known at this moment are about half as massive as Saturn, i.e. about 50 times more massive than the Earth. Astronomers are hunting exoplanets not just to discover more such objects, but also to learn more about the apparent diversity of planetary systems. The current main research goal is to eventually discover an Earth-like exoplanet, but the available telescopes and instrumentation are still not "sensitive" enough for this daunting task. However, also in this context, it is highly desirable to know not only the orbits of the observable exoplanets, but also their true masses . But this is not an easy task. Masses of exoplanets Virtually all exoplanets detected so far have been found by an indirect method - the measurement of stellar velocity variations . It is based on the gravitational pull of the orbiting planet that causes the central star to move a little back and forth; the heavier the planet, the greater is the associated change in the star's velocity. This technique is rapidly improving: the new HARPS spectrograph (High Accuracy Radial Velocity Planet Searcher) , now being tested on the 3.6-m telescope at the ESO La Silla Observatory , can measure such stellar motions with an unrivalled accuracy of about 1 metre per second (m/s), cf. ESO PR 06/03 . It will shortly be able to search for exoplanets only a few times more massive than the Earth. However, velocity measurements alone do not allow to determine the true mass of the orbiting planet. Because of the unknown inclination of the planetary orbit (to the line-of-sight), they only provide a lower limit to this mass . Additional information about this orbital inclination is therefore needed to derive the true mass of an exoplanet. The transit method Fortunately, this information becomes available if the exoplanet is known to move across ("transit") the star's disk, as seen from the Earth; the orbital plane must then necessarily be very near the line-of-sight. This phenomenon is exactly the same that happens in our own solar system, when the inner planets Mercury and Venus pass in front of the solar disk, as seen from the Earth [3]. A solar eclipse (caused by the Moon moving in front of the Sun) is a more extreme case of the same type of event. During such an exoplanet transit, the observed brightness of the star will decrease slightly because the planet blocks a part of the stellar light. The larger the planet, the more of the light is blocked and the more the brightness of the star will decrease. A study of the way this brightness changes with time (astronomers refer to the "light curve"), when combined with radial velocity measurements, allows a complete determination of the planetary orbit, including the exact inclination. It also provides accurate information about the planet's size, true mass and hence, density. The chances that a particular exoplanet passes in front of the disk of its central star as seen from the Earth are small. However, because of the crucial importance of such events in order to characterize exoplanets fully, astronomers have for some time been actively searching for stars that experience small regularly occurring "brightness dips" that might possibly be caused by exoplanetary transits. The OGLE list Last year, a first list of 59 such possible cases of stars with transiting planets was announced by the Optical Gravitational Lensing Experiment (OGLE) [2]. These stars were found - within a sample of about 5 million stars observed during a 32-day period - to exhibit small and regular brightness dips that might possibly be caused by transits of an exoplanet. For one of these stars, OGLE-TR-56 , a team of American astronomers soon thereafter observed slight variations of the velocity , strongly indicating the presence of an exoplanet around that star. UVES spectra of OGLE-TR-3 ESO PR Photo 10a/03 ESO PR Photo 10a/03 [Preview - JPEG: 400 x 466 pix - 41k [Normal - JPEG: 800 x 931 pix - 280k] ESO PR Photo 10b/03 ESO PR Photo 10b/03 [Preview - JPEG: 492 x 400 pix - 52k [Normal - JPEG: 984 x 800 pix - 224k] Captions : PR Photo 10a/03 shows the 16.5-mag star OGLE-TR-3 , a solar-like star in the direction of the Galactic Center, discovered during an extensive photometric search for planetary and low-luminosity object transits [2]. The image is reproduced from an I-band CCD frame of a 1 x 1 arcmin 2 sky field. North is up and East is left. PR Photo 10b/03 displays a small portion of a high-dispersion spectrum of OGLE-TR-3 , obtained with the UVES spectrograph at the 8.2-m VLT KUEYEN telescope at the Paranal Observatory (Chile). It is divided into five adjacent wavelength intervals and represents the mean of ten 1-hour spectral exposures. The fully drawn curve shows the spectrum of the "best fitting" stellar model from which the composition, temperature, mass, age of OGLE-TR-3 were deduced. Now, a team of German and ESO astronomers [1] have used the UVES High-Dispersion Spectrograph on the 8.2-m VLT KUEYEN telescope at the Paranal Observatory (Chile) to obtain very detailed spectra of another star on that list, OGLE-TR-3 , cf. PR Photos 10a-b/03 . Over a period of one month, a total of ten high-resolution spectra - each with an exposure time of about one hour - were obtained of the 16.5-mag object, i.e. its brightness is about 16,000 fainter that what can be perceived with the unaided eye. A careful evaluation shows that OGLE-TR-3 is very similar to the Sun, with a temperature of about 5800 °C (6100 K). And most interestingly, it undergoes velocity variations of the order of 120 m/s . The exoplanet at OGLE-TR-3 ESO PR Photo 10c/03 ESO PR Photo 10c/03 [Preview - JPEG: 400 x 507 pix - 24k [Normal - JPEG: 800 x 1014 pix - 95k] ESO PR Photo 10d/03 ESO PR Photo 10d/03 [Preview - JPEG: 466 x 400 pix - 20k [Normal - JPEG: 932 x 800 pix - 120k] ESO PR Photo 10e/03 ESO PR Photo 10e/03 [Preview - JPEG: 510 x 200 pix - 21k [Normal - JPEG: 1024 x 400 pix - 120k] Captions : PR Photo 10c/03 illustrates the relationship between the variations in stellar brightness and velocity, caused by an orbiting exoplanet that transits the disk of its central star. Consecutive positions of the planet in its (circular) orbit are marked by black dots, with the motion from left to right. The figure has been drawn to scale, i.e. the dots actually represent the size of the planet itself. At the top is the view of the planetary orbit from above - below a view from the Earth with the planetary transit. Further down, the lightcurve with a brightness (intensity) dip when the planet blocks a small part of the star's light is shown, and at the bottom the corresponding change in the star's velocity. Before the transit, when the planet moves towards us, the star moves in the opposite direction, i.e. away from us and the velocity is positive; during the transit, the relative velocity is zero and later is becomes negative as the star moves towards us. PR Photo 10d/03 displays the velocity variation of the star OGLE-TR-3 , as measured from ten VLT-UVES spectra (each with 1-hour exposure time) and plotted according to the "photometric phase". This means that the planetary transit occurs at phase 0 (left) and again at phase 1 (right). The observed variation is in agreement with the expected one, cf. PR Photo 10c/03 . The fully drawn curve represents the best fit to the observations (velocity variation about 120 m/s) - the mass of the planet is derived from this. PR Photo 10e/03 shows the brightness variation ("light-curve") of the star OGLE-TR-3 obtained during the OGLE observations [2]. The crosses correspond to the observations and the fully drawn curve represents a model fit, with the stellar parameters from the analysis of the UVES spectra (1 solar radius and 1 solar mass) and the planetary parameters from the velocity analysis (0.6 Jupiter mass). The best fit allows determination of the planet's size as about 200,000 km (1.4 times the size of Jupiter). The 2 per cent dip in the brightness of OGLE-TR-3 , as observed during the OGLE programme, occurs every 28 hours 33 minutes (1.1899 days), cf. PR Photo 10e/03 . The UVES velocity measurements ( PR Photo 10d/03 ) fit this period well and reveal, with high probability, the presence of an exoplanet orbiting OGLE-TR-3 with this period. In any case, the observations firmly exclude that the well observed brightness variations could be due to a small stellar companion. A red dwarf star would have caused velocity variations of 15 km/s and a brown dwarf star 2.5 km/s; both would have been easy to observe with UVES, and it is clear that such variations can be excluded. Although the available observations are still insufficient to allow an accurate determination of the planetary properties, the astronomers provisionally deduce a true mass of the planet of the order of one half of that of Jupiter . The density is found to be about 250 kg/m 3 , only one-quarter of that of water or one-fifth of that of Jupiter, so the planet is quite big for this mass - a bit "blown up". It is obviously a planet of the gaseous type . A very hot planet The orbital period, 28 hours 33 minutes (1.1899 days), is the shortest known for any exoplanet and the distance between the star and the planet is correspondingly small, only 3.5 million kilometres . The temperature of the side of the planet facing the star must therefore be very high, of the order of 2000 °C . Clearly, the planet must be losing its atmosphere by evaporation. The astronomers also conclude that it might in fact be possible to observe this exoplanet directly because of its comparatively strong infrared radiation. An attempt to do so will soon be made. As only the third exoplanet found this way (after those at the stars HD209458 and OGLE-TR-56 ), the new object confirms the current impression that a considerable number of stars may possess giant planets in close orbits. Since such planets cannot form so close to their parent star, they must have migrated inwards to the current orbit from a much larger, initial distance. It is not known at this time with certainty how this might happen. Future prospects It is expected that more observational campaigns will be made to search for transiting planets around other stars. There is good hope that OGLE-TR-3 and OGLE-TR-56 are just the first two of a substantial number of exoplanets to be discovered this way. Some years from now, searches will also begin from dedicated space observatories, e.g. ESA's Eddington and Darwin , and NASA's Kepler .

  7. A Catalog of Transit Timing Posterior Distributions for all Kepler Planet Candidate Transit Events

    NASA Astrophysics Data System (ADS)

    Montet, Benjamin Tyler; Becker, Juliette C.; Johnson, John Asher

    2015-12-01

    Kepler has ushered in a new era of planetary dynamics, enabling the detection of interactions between multiple planets in transiting systems for hundreds of systems. These interactions, observed as transit timing variations (TTVs), have been used to find non-transiting companions to transiting systems and to measure masses, eccentricities, and inclinations of transiting planets. Often, physical parameters are inferred by comparing the observed light curve to the result of a photodynamical model, a time-intensive process that often ignores the effects of correlated noise in the light curve. Catalogs of transit timing observations have previously neglected non-Gaussian uncertainties in the times of transit, uncertainties in the transit shape, and short cadence data. Here, I present a catalog of not only times of transit centers, but also posterior distributions on the time of transit for every planet candidate transit event in the Kepler data, developed through importance sampling of each transit. This catalog allows one to marginalize over uncertainties in the transit shape and incorporate short cadence data, the effects of correlated noise, and non-Gaussian posteriors. Our catalog will enable dynamical studies that reflect accurately the precision of Kepler and its limitations without requiring the computational power to model the light curve completely with every integration. I will also present our open-source N-body photodynamical modeling code, which integrates planetary and stellar orbits accounting for the effects of GR, tidal effects, and Doppler beaming.

  8. Atomic Transitions in Dense Plasmas

    NASA Astrophysics Data System (ADS)

    Murillo, Michael Sean

    Motivation for the study of hot, dense ( ~solid density) plasmas has historically been in connection with stellar interiors. In recent years, however, there has been a growing interest in such plasmas due to their relevance to short wavelength (EUV and x-ray) lasers, inertial confinement fusion, and optical harmonic generation. In constrast to the stellar plasmas, these laboratory plasmas are typically composed of high-z elements and are not in thermal equilibrium. Descriptions of nonthermal plasma experiments must necessarily involve the consideration of the various atomic processes and the rates at which they occur. Traditionally, the rates of collisional atomic processes are calculated by considering a binary collision picture. For example, a single electron may be taken to collisionally excite an ion. A cross section may be defined for this process and, multiplying by a flux, the rate may be obtained. In a high density plasma this binary picture clearly breaks down as the electrons no longer act independently of each other. The cross section is ill-defined in this regime and another approach is needed to obtain rates. In this thesis an approach based on computing rates without recourse to a cross section is presented. In this approach, binary collisions are replaced by stochastic density fluctuations. It is then these density fluctuations which drive transitions in the ions. Furthermore, the oscillator strengths for the transitions are computed in screened Coulomb potentials which reflect the average polarization of the plasma near the ion. Numerical computations are presented for the collisional ionization rate. The effects of screening in the plasma -ion interaction are investigated for He^+ ions in a plasma near solid density. It is shown that dynamic screening plays an important role in this process. Then, density effects in the oscillator strength are explored for both He^+ and Ar^{+17}. Approximations which introduce a nonorthogonality between the initial and final states is shown to introduce a nonnegligible error. Changes in the bound state energy levels are included in the calculation as well and are shown to dramatically increase the ionization rate over the low density result. Finally, a calculation is presented in which the final state wavefunctions are found exactly within a (density-dependent) screened Coulomb potential.

  9. Cosmological Consequences of QCD Phase Transition(s) in Early Universe

    SciTech Connect

    Tawfik, A.

    2009-04-17

    We discuss the cosmological consequences of QCD phase transition(s) on the early universe. We argue that our recent knowledge about the transport properties of quark-gluon plasma (QGP) should thraw additional lights on the actual time evolution of our universe. Understanding the nature of QCD phase transition(s), which can be studied in lattice gauge theory and verified in heavy ion experiments, provides an explanation for cosmological phenomenon stem from early universe.

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

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

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

    ERIC Educational Resources Information Center

    Noel, Andrea

    2011-01-01

    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…

  12. Project STEPS: Assessment of Current Transition Practices and Transition System Development Plan.

    ERIC Educational Resources Information Center

    Rous, Beth

    This set of forms is part of Project STEPS (Sequenced Transition to Education in the Public Schools). They are intended to assist communities develop and use a formalized process for assessing the current status of transition within their community and for interagency planning related to the development of a community-wide transition team. The

  13. Bullying and school transition: Context or development?

    PubMed

    Wang, Weijun; Brittain, Heather; McDougall, Patricia; Vaillancourt, Tracy

    2016-01-01

    The relative impact of school transition versus development on peer victimization and bullying perpetration were examined in a natural experiment involving 698 students where half transitioned into middle school from Grade 5 to Grade 6 and the other half remained in their elementary school over the same period. Results indicated that, on average, peer victimization decreased over the transition period while bullying perpetration remained stable for the whole sample. Multilevel modeling was used to investigate the effects of school transition and sex on changes in victimization and perpetration. Results indicated that the effect of transition status on changes in peer victimization was moderated by sex. Middle school transition status predicted decreases in peer victimization for girls, but not for boys, who transitioned. However, school transition status and participants' sex (and their interaction) did not predict changes in perpetration over time. Our findings indicate that changes in student involvement with peer victimization are better understood as a contextual rather than a typical developmental process, whereas bullying perpetration may be better understood as developmental. PMID:26522183

  14. The Chancellor's Role in a Presidential Transition

    ERIC Educational Resources Information Center

    Appleton, James R.; Dorsey, Stuart

    2009-01-01

    Successful transitions involving a formal role for the former president, such as chancellor, are rare enough that the authors think theirs is an exceptional experience and is worth sharing, especially given the bulge of presidential retirements anticipated over the next decade. The authors believe that this model of transition can be successful,…

  15. Structure and Agency in Transition Research

    ERIC Educational Resources Information Center

    Heinz, Walter R.

    2009-01-01

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

  16. Phase transitions in the web of science

    NASA Astrophysics Data System (ADS)

    Phillips, J. C.

    2015-06-01

    The Internet age is changing the structure of science, and affecting interdisciplinary interactions. Publication profiles connecting mathematics with molecular biology and condensed matter physics over the last 40 years exhibit common phase transitions indicative of the critical role played by specific interdisciplinary interactions. The strengths of the phase transitions quantify the importance of interdisciplinary interactions.

  17. Effective Transition Planning for Learners with ASD

    ERIC Educational Resources Information Center

    Gerhardt, Peter F.

    2007-01-01

    Despite the transition requirements of Individuals with Disabilities Education Act (IDEA) and a growing body of research in support of effective transition planning for learners with an autism spectrum disorder (ASD), many adults on the spectrum remain without employment in large numbers. Even for those generally regarded as most capable, they…

  18. 32 CFR 196.230 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL... a single transition plan applicable to all such units, or a separate transition plan applicable to... unit admits students of both sexes as regular students and, if so, when it began to do so. (3)...

  19. 44 CFR 19.230 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES... submit either a single transition plan applicable to all such units, or a separate transition plan... unit admits students of both sexes as regular students and, if so, when it began to do so. (3)...

  20. 29 CFR 36.230 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING... submit either a single transition plan applicable to all such units, or a separate transition plan... unit admits students of both sexes as regular students and, if so, when it began to do so. (3)...

  1. 10 CFR 5.230 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING... either a single transition plan applicable to all such units, or a separate transition plan applicable to... unit admits students of both sexes as regular students and, if so, when it began to do so. (3)...

  2. Building Bridges: Understanding Student Transition to University

    ERIC Educational Resources Information Center

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

    2012-01-01

    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

  3. Structure and Agency in Transition Research

    ERIC Educational Resources Information Center

    Heinz, Walter R.

    2009-01-01

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

  4. Transition to School: Revisiting the Bridge Metaphor

    ERIC Educational Resources Information Center

    Huser, Carmen; Dockett, Sue; Perry, Bob

    2016-01-01

    Policymakers, researchers and educators around the world have acknowledged the importance of children's transition to school, both as a significant life event and as a factor in future engagement with education. As a result, much attention has been directed towards researching transition experiences, developing policies to support positive…

  5. Tying Signals: Restoring Classroom Order after Transitions

    ERIC Educational Resources Information Center

    Icbay, Mehmet Ali

    2011-01-01

    This study aimed at publicly demonstrating how classroom order is mutually established by a teacher and students in transition periods. Transitions take place in each instance when a current activity finishes, simultaneously the contextual organisation of the activity changes, and then the previously established order is lost. As a result, the…

  6. Transition Strategies for Persons with Learning Disabilities.

    ERIC Educational Resources Information Center

    Michaels, Craig A., Ed.

    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…

  7. Understanding Secondary-Tertiary Transition in Mathematics

    ERIC Educational Resources Information Center

    Clark, Megan; Lovric, Miroslav

    2009-01-01

    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…

  8. Transitions to School: Reframing Professional Relationships

    ERIC Educational Resources Information Center

    Boyle, Tess; Petriwskyj, Anne

    2014-01-01

    Systemic splits between pre-compulsory and compulsory early years education impact on transitions to school through discontinuities in children's experience. This paper presents data from a critical participatory action research project about transitions between pre-compulsory and compulsory early education schooling in Australia. The project

  9. Middle Grades Transition Programs around the Globe

    ERIC Educational Resources Information Center

    Andrews, Colin; Bishop, Penny

    2012-01-01

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

  10. Collaborating in the Transition to Tertiary Writing.

    ERIC Educational Resources Information Center

    Clerehan, Rosemary; Moore, Tim; Vance, Sheila

    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…

  11. Method for dry etching of transition metals

    DOEpatents

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

    1998-09-29

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

  12. The Role of Transitions in ESL Instruction

    ERIC Educational Resources Information Center

    Steinman, Linda

    2013-01-01

    Transitions in ESL contexts generally refer to those linking words placed between sentences and between paragraphs. Transitions in writing (and in speaking) are helpful; they facilitate coherence and cohesion when used correctly. Understanding them when reading allows us to join the writer in seeing why and how idea B follows idea A. In this…

  13. 13 CFR 113.230 - Transition plans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Transition plans. 113.230 Section 113.230 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NONDISCRIMINATION IN FINANCIAL... plan applicable to all such units, or a separate transition plan applicable to each such unit....

  14. 13 CFR 113.230 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Transition plans. 113.230 Section 113.230 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NONDISCRIMINATION IN FINANCIAL... plan applicable to all such units, or a separate transition plan applicable to each such unit....

  15. 45 CFR 149.105 - Transition provision.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Transition provision. 149.105 Section 149.105 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE EARLY RETIREE REINSURANCE PROGRAM Reinsurance Amounts § 149.105 Transition provision....

  16. 45 CFR 86.17 - Transition plans.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Transition plans. 86.17 Section 86.17 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Coverage § 86.17 Transition plans. (a) Submission of plans....

  17. The Community Transition Center (CTC) Model.

    ERIC Educational Resources Information Center

    Coker, Charles C.; Costello, James

    This paper describes the Community Transition Center (CTC) model, being tested in six districts in rural Wisconsin. The model is a way of conceptualizing and organizing the employment-related needs of mainstreamed mildly handicapped youths who are exiting secondary schools. The model emphasizes the role of secondary school transition programming,…

  18. 12 CFR 1273.10 - Transition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 9 2013-01-01 2013-01-01 false Transition. 1273.10 Section 1273.10 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS OFFICE OF FINANCE § 1273.10 Transition. (a... 1, 2010, unless the board of directors established under this part determines that the...

  19. 12 CFR 1273.10 - Transition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Transition. 1273.10 Section 1273.10 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS OFFICE OF FINANCE § 1273.10 Transition. (a... 1, 2010, unless the board of directors established under this part determines that the...

  20. 12 CFR 1273.10 - Transition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 9 2012-01-01 2012-01-01 false Transition. 1273.10 Section 1273.10 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS OFFICE OF FINANCE § 1273.10 Transition. (a... 1, 2010, unless the board of directors established under this part determines that the...

  1. 7 CFR 15a.18 - Transition plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Transition plans. 15a.18 Section 15a.18 Agriculture... FEDERAL FINANCIAL ASSISTANCE Coverage § 15a.18 Transition plans. (a) Submission of plans. An institution... separate unit any obstacles to admitting students without discrimination on the basis of sex. (4)...

  2. 7 CFR 15a.18 - Transition plans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Transition plans. 15a.18 Section 15a.18 Agriculture... FEDERAL FINANCIAL ASSISTANCE Coverage § 15a.18 Transition plans. (a) Submission of plans. An institution... separate unit any obstacles to admitting students without discrimination on the basis of sex. (4)...

  3. 7 CFR 15a.18 - Transition plans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Transition plans. 15a.18 Section 15a.18 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Coverage § 15a.18 Transition plans. (a) Submission of plans. An institution to which § 15a.17 applies and which...

  4. 7 CFR 15a.18 - Transition plans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Transition plans. 15a.18 Section 15a.18 Agriculture... FEDERAL FINANCIAL ASSISTANCE Coverage § 15a.18 Transition plans. (a) Submission of plans. An institution... separate unit any obstacles to admitting students without discrimination on the basis of sex. (4)...

  5. 7 CFR 15a.18 - Transition plans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Transition plans. 15a.18 Section 15a.18 Agriculture... FEDERAL FINANCIAL ASSISTANCE Coverage § 15a.18 Transition plans. (a) Submission of plans. An institution... separate unit any obstacles to admitting students without discrimination on the basis of sex. (4)...

  6. Transit Timing Variations of Kepler Planets

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

    For a transiting planet following a fixed Keplerian ellipse, observers would measure a constant interval between successive transits. Orbital precession induced by general relativity, a planetary tidal bulge, or stellar oblateness could result in a variation of the transit interval for a planet with an eccentric or inclined orbit. Furthermore, tidal dissipation should alter the orbital period of the planet. These slow effects can only be detected over several years. However, the gravitational influence of other planets in the system can yield a detectable change in the transit interval over much shorter time scales. With the precision and continuous monitoring provided by Kepler photometry, the presence of sub-Earth mass planets in resonance, as well as larger planets at a wide range of orbital periods could, in principle, be readily detected. With the detection of transit timing variations in systems with multiple transiting bodies, such as Kepler-9, it is possible to establish from the transit observations alone that these bodies have planetary masses. But the combination of Kepler photometry with high-precision radial velocity observations is particularly powerful in establishing the orbital and physical properties of such systems. We will present the results of the analyses of transit timing variations in exoplanet systems observed by Kepler to date. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate.

  7. Factors Affecting Third Culture Kids' (TCKs) Transition

    ERIC Educational Resources Information Center

    Morales, Antonio

    2015-01-01

    (TCKs) transition becomes challenging for both the student and the school. The programs implemented, or lack thereof, are imperative to the successful transition of TCKs into their new, diverse, multicultural environment. Research has been written on the positive effects and challenges faced by TCKs' transient lifestyle. Although international…

  8. Off to Kindergarten: Toolbox for Effective Transitions.

    ERIC Educational Resources Information Center

    Vermont Early Childhood Work Group.

    Noting that the transition to school often sets the tone for the childs future school experiences, this toolbox identifies 33 proven practices currently used by schools districts and early childhood programs throughout Vermont to help children make a successful adjustment to school. Beginning with a list of guiding concepts on transition and…

  9. Transition Management: The Student Teacher's Achilles Heel.

    ERIC Educational Resources Information Center

    Martin, Dawn Vincent

    Classroom observation of four student teachers during the first, seventh, and fourteenth weeks of their teaching semester focused on their management of transition periods between lesson segments. Videotapes and stimulated recall analysis of the differences revealed that: (1) the most effective student teachers averaged fewer transitions per…

  10. 42 CFR 413.239 - Transition period.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-treatment payment amount for renal dialysis services (as defined in § 413.171 of this part) and home dialysis, provided during the transition as follows— (1) For services provided on and after January 1, 2011... election to be paid for renal dialysis services provided during the transition based on 100 percent of...

  11. 12 CFR 23.12 - Transition rule.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Transition rule. 23.12 Section 23.12 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LEASING CEBA Leases § 23.12 Transition... its cost of financing, the leased property....

  12. 42 CFR 414.44 - Transition rules.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Transition rules. 414.44 Section 414.44 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Physicians and Other Practitioners § 414.44 Transition rules. (a)...

  13. 12 CFR 3.3 - Transitional rules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Transitional rules. 3.3 Section 3.3 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE OF DIRECTIVES Authority and Definitions § 3.3 Transitional rules. Intangible assets, other than...

  14. 12 CFR 3.3 - Transitional rules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Transitional rules. 3.3 Section 3.3 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE OF DIRECTIVES Authority and Definitions § 3.3 Transitional rules. Intangible assets, other than...

  15. Financial Management for Transit: A Handbook.

    ERIC Educational Resources Information Center

    Heaselden, Mark; And Others

    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,…

  16. Magnetic fields from the electroweak phase transition

    SciTech Connect

    Tornkvist, O.

    1998-02-01

    I review some of the mechanisms through which primordial magnetic fields may be created in the electroweak phase transition. I show that no magnetic fields are produced initially from two-bubble collisions in a first-order transition. The initial field produced in a three-bubble collision is computed. The evolution of fields at later times is discussed.

  17. Sustaining Secondary Transition Programs in Local Schools

    ERIC Educational Resources Information Center

    Benz, M. R.; Lindstrom, L.; Unruh, D.; Waintrup, M.

    2004-01-01

    This article reports on factors that influence the sustainability of secondary transition innovations in local schools. We used a two-stage research process, which combined broad survey methods and an embedded case study design, to investigate the sustainability of a specific school-to-community transition model for youth with disabilities. We…

  18. 42 CFR 412.533 - Transition payments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Long-Term Care Hospitals § 412.533 Transition payments. (a) Duration of transition periods. Except for a long-term care hospital that makes an election under paragraph (c) of this section or for a long-term care hospital...

  19. 12 CFR 931.9 - Transition provision.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Transition provision. 931.9 Section 931.9 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK RISK MANAGEMENT AND CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL STOCK § 931.9 Transition provision. (a) In general. Each Bank shall comply with the minimum leverage and...

  20. Transitions to College: From Theory to Practice

    ERIC Educational Resources Information Center

    Social Science Research Council, 2004

    2004-01-01

    In the fall of 2003 the Social Science Research Council (SSRC) established a project entitled "Transitions to College: From Theory to Practice." This project focuses on postsecondary transition and retention successes and failures associated with America's disadvantaged youth. Lumina Foundation for Education is providing support for this effort.…

  1. 42 CFR 414.44 - Transition rules.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Transition rules. 414.44 Section 414.44 Public... § 414.44 Transition rules. (a) Adjusted historical payment basis—(1) All services other than radiology... services furnished during CY 1992 the following rules apply: (1) If the AHPB determined under paragraph...

  2. 12 CFR 23.12 - Transition rule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Transition rule. 23.12 Section 23.12 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LEASING CEBA Leases § 23.12 Transition rule. (a) General rule. A CEBA Lease entered into prior to July 22, 1991, may continue to...

  3. 12 CFR 23.22 - Transition rule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Transition rule. 23.22 Section 23.22 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LEASING Section 24(Seventh) Leases § 23.22 Transition rule. (a) Exclusion. A Section 24(Seventh) Lease entered into prior to June 12, 1979, may...

  4. 11 CFR 300.12 - Transition rules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... effect between November 6 and December 31, 2002: 11 CFR 106.5(a),(b), (c), (f) and (g). ... 11 Federal Elections 1 2011-01-01 2011-01-01 false Transition rules. 300.12 Section 300.12 Federal... FUNDS National Party Committees § 300.12 Transition rules. (a) Permissible uses of excess...

  5. Children's Agency during Transition to Formal Schooling

    ERIC Educational Resources Information Center

    Huf, Christina

    2013-01-01

    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…

  6. 45 CFR 1634.10 - Transition provisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Transition provisions. 1634.10 Section 1634.10 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION COMPETITIVE BIDDING FOR GRANTS AND CONTRACTS § 1634.10 Transition provisions. (a) When the competitive bidding process results in the award of a grant...

  7. Electron microscopy: Phase transition singled out

    NASA Astrophysics Data System (ADS)

    Browning, Nigel D.

    2013-05-01

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

  8. Disproportionality in Transition Services: A Descriptive Study

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  9. Changes and Exchanges in Marginal Youth Transitions

    ERIC Educational Resources Information Center

    Bottrell, Dorothy; Armstrong, Derrick

    2007-01-01

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

  10. A Conceptual Model for Leadership Transition

    ERIC Educational Resources Information Center

    Manderscheid, Steven V.; Ardichvili, Alexandre

    2008-01-01

    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…

  11. Learning through Transitions: The Role of Institutions

    ERIC Educational Resources Information Center

    Zittoun, Tania

    2008-01-01

    In this paper two models are proposed for analysing transitions in education. Firstly, transitions are the processes that follow ruptures perceived by people. They include learning, identity change, and meaning making processes. Secondly, processes of change are observed through a semiotic prism, articulating self-other-object-sense of the object…

  12. College Students in Transition: An Annotated Bibliography

    ERIC Educational Resources Information Center

    Foote, Stephanie M., Ed.; Hinkle, Sara M., Ed.; Kranzow, Jeannine, Ed.; Pistilli, Matthew D., Ed.; Miles, LaTonya Rease, Ed.; Simmons, Jannell G., Ed.

    2013-01-01

    The transition from high school to college is an important milestone, but it is only one of many steps in the journey through higher education. This volume is an annotated bibliography of the emerging literature examining the many other transitions students make beyond the first year, including the sophomore year, the transfer experience, and the…

  13. Transitional Dialects between Bhojpuri and Maithili.

    ERIC Educational Resources Information Center

    Sonntag, Selma K.

    A dialect survey of the transition between two major Indo-Aryan languages in Nepal, Bhojpuri and Maithili, was conducted focusing on both the linguistic and sociolinguistic aspects of the various languages and dialects. The purpose of the study was to find out where and how this transition occurred between the pure Bhojpuri-speaking area and the…

  14. Youth in Transition: Are They Adult Learners?

    ERIC Educational Resources Information Center

    Shaw, Lester H.; Conti, Gary J.; Shaw, Brenda S.

    2013-01-01

    Since at-risk youth are in transition to adulthood, major adult learning concepts can be applied to them. The purpose of this study was to describe the learning strategies of youth in transition to adulthood in the urban life skills program of A Pocket Full of Hope®. Both qualitative and quantitative data collecting methods were used. Assessing…

  15. Energy Transition Initiative: Islands Playbook (Book)

    SciTech Connect

    Not Available

    2015-01-01

    The Island Energy Playbook (the Playbook) provides an action-oriented guide to successfully initiating, planning, and completing a transition to an energy system that primarily relies on local resources to eliminate a dependence on one or two imported fuels. It is intended to serve as a readily available framework that any community can adapt to organize its own energy transition effort.

  16. Transition metals activate TFEB in overexpressing cells

    PubMed Central

    Peña, Karina A.; Kiselyov, Kirill

    2015-01-01

    Transition metal toxicity is an important factor in the pathogenesis of numerous human disorders, including neurodegenerative diseases. Lysosomes have emerged as important factors in transition metal toxicity because they handle transition metals via endocytosis, autophagy, absorption from the cytoplasm and exocytosis. Transcription factor EB (TFEB) regulates lysosomal biogenesis and the expression of lysosomal proteins in response to lysosomal and/or metabolic stresses. Since transition metals cause lysosomal dysfunction, we proposed that TFEB may be activated to drive gene expression in response to transition metal exposure and that such activation may influence transition metal toxicity. We found that transition metals copper (Cu) and iron (Fe) activate recombinant TFEB and stimulate the expression of TFEB-dependent genes in TFEB-overexpressing cells. In cells that show robust lysosomal exocytosis, TFEB was cytoprotective at moderate levels of Cu exposure, decreasing oxidative stress as reported by the expression of heme oxygenase-1 (HMOX1) gene. However, at high levels of Cu exposure, particularly in cells with low levels of lysosomal exocytosis, activation of overexpressed TFEB was toxic, increasing oxidative stress and mitochondrial damage. Based on these data, we conclude that TFEB-driven gene network is a component of the cellular response to transition metals. These data suggest limitations and disadvantages of TFEB overexpression as a therapeutic approach. PMID:26251447

  17. Transitions in the Development of Giftedness

    ERIC Educational Resources Information Center

    Bonner, Fred A., II

    2005-01-01

    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…

  18. Method for dry etching of transition metals

    DOEpatents

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

    1998-01-01

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

  19. Transformative Learning in Managerial Role Transitions

    ERIC Educational Resources Information Center

    Isopahkala-Bouret, Ulpukka

    2008-01-01

    The purpose of this study is to investigate the nature of learning in work role transitions from specialist roles to managerial roles in a context of a large international technology organisation. Prior theorisation of learning in role transitions has been based on quantitative, psychologically-oriented studies prescribing different role and…

  20. Promoting Healthy Transitions from Preschool to Kindergarten

    ERIC Educational Resources Information Center

    Steen, Bweikia Foster

    2011-01-01

    Research shows that when children do not transition successfully to kindergarten, their academic and social-emotional progress can be hindered, whereas children who transition successfully actively engage in learning and adapt to the new setting (Harbin et al. 2007). It is important for early childhood educators to consider the stress for children…

  1. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2010-02-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A continuing explosion of discoveries by transit surveys have given us a sample of 45 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  2. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2009-08-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A recent explosion of discoveries by transit surveys have given us a sample of 37 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  3. Transition: Old Wine in New Bottles.

    ERIC Educational Resources Information Center

    Halpern, Andrew S.

    1992-01-01

    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.…

  4. 40 CFR 7.75 - Transition plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... RECEIVING FEDERAL ASSISTANCE FROM THE ENVIRONMENTAL PROTECTION AGENCY Discrimination Prohibited on the Basis of Handicap § 7.75 Transition plan. If structural changes to facilities are necessary to make the...) Requirements. The transition plan must set forth the steps needed to complete the structural changes...

  5. 40 CFR 7.75 - Transition plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Transition plan. 7.75 Section 7.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL ASSISTANCE FROM THE ENVIRONMENTAL PROTECTION AGENCY Discrimination Prohibited on the Basis of Handicap § 7.75 Transition...

  6. Building Bridges: Understanding Student Transition to University

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

  7. Transition prediction using three dimensional stability analysis

    NASA Technical Reports Server (NTRS)

    Malik, M. R.

    1980-01-01

    Several methods of transition prediction by linear stability analysis are compared. The spectral stability analysis code SALLY is used to analyze flows over laminar flow control wings. It is shown that transition by the envelope method and a new modified wave packet method are comparable in reliability but that the envelope method is more efficient computationally.

  8. Transition Strategies to Ensure Active Student Engagement

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  9. Youth Transitions: From Offending to Desistance

    ERIC Educational Resources Information Center

    Barry, Monica

    2010-01-01

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

  10. Transition to Kindergarten: Family Experiences and Involvement

    ERIC Educational Resources Information Center

    McIntyre, Laura Lee; Eckert, Tanya L.; Fiese, Barbara H.; DiGennaro, Florence D.; Wildenger, Leah K.

    2007-01-01

    The transition to kindergarten is an important developmental milestone for young children, their families, and teachers. Preparing students for successful kindergarten transition has been identified as a national priority, yet the degree to which parents are involved in kindergarten preparation is rarely considered. This study investigated the…

  11. Infant Mother Vocalization Patterns in Transition.

    ERIC Educational Resources Information Center

    Kilbourne, Brock K.; Ginsburg, Gerald P.

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

  12. Mystified by Menopause? A Major Life Transition

    MedlinePlus

    ... please review our exit disclaimer . Subscribe Mystified by Menopause? A Major Life Transition Menopause—it’s a transition that looms large in the ... 50. It’s sometimes called the “change of life.” Menopause marks the end of menstrual periods and fertility. ...

  13. 9 CFR 332.12 - Transition grants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... in the development of sanitation standard operating procedures required under part 416 of this....12 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CARCASSES, MEAT, AND MEAT FOOD PRODUCTS § 332.12 Transition grants. (a) Transition grants are funds that...

  14. Phase transitions in semidefinite relaxations

    PubMed Central

    Javanmard, Adel; Montanari, Andrea; Ricci-Tersenghi, Federico

    2016-01-01

    Statistical inference problems arising within signal processing, data mining, and machine learning naturally give rise to hard combinatorial optimization problems. These problems become intractable when the dimensionality of the data is large, as is often the case for modern datasets. A popular idea is to construct convex relaxations of these combinatorial problems, which can be solved efficiently for large-scale datasets. Semidefinite programming (SDP) relaxations are among the most powerful methods in this family and are surprisingly well suited for a broad range of problems where data take the form of matrices or graphs. It has been observed several times that when the statistical noise is small enough, SDP relaxations correctly detect the underlying combinatorial structures. In this paper we develop asymptotic predictions for several detection thresholds, as well as for the estimation error above these thresholds. We study some classical SDP relaxations for statistical problems motivated by graph synchronization and community detection in networks. We map these optimization problems to statistical mechanics models with vector spins and use nonrigorous techniques from statistical mechanics to characterize the corresponding phase transitions. Our results clarify the effectiveness of SDP relaxations in solving high-dimensional statistical problems. PMID:27001856

  15. Atomic inner-shell transitions

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  16. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    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.

  17. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    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.

  18. Lunar transit telescope lander design

    NASA Astrophysics Data System (ADS)

    Omar, Husam A.

    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.

  19. Lunar transit telescope lander design

    NASA Astrophysics Data System (ADS)

    Omar, Husam A.

    1991-10-01

    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.

  20. The Soviet Union in transition

    SciTech Connect

    Niiseki, K.

    1987-01-01

    Because of the recent transition in the Soviet Union's leadership, scholars worldwide have found it necessary to reevaluate Soviet domestic and foreign policy. In this book, prominent Japanese, U.S., and European experts examine changes within the USSR as well as Soviet reactions to changes in the rest of the world. They assess the immediate implications of change for such areas as technology, energy policy, and economic reform and deliver commentaries on current policy directions and historical backgrounds of Soviet policies. The Japan Institute of International Affairs held the symposium on which this volume is based to commemorate its silver jubilee and to add the valuable perspective of Japanese Soviet studies scholars to Western analyses. Contents: Introduction; The Soviet Union in a Changing World; East-West Relations: A European Perspective; ''Gorbachevism''-Simply Old Wine in a New Bottle. Implications of Leadership and Social Change for Soviet Policies; Soviet Economic Trends, with Special Emphasis on Investment and Energy Policies; Economic Reforms in China in Light of Soviet and Eastern European Experiences.

  1. QCD Phase Transitions, Volume 15

    SciTech Connect

    Schaefer, T.; Shuryak, E.

    1999-03-20

    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.

  2. State Transitions in Semiarid Landscapes

    NASA Astrophysics Data System (ADS)

    Phillips, J. D.

    2012-04-01

    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.

  3. Metabolic transit of dietary methylglyoxal.

    PubMed

    Degen, Julia; Vogel, Maria; Richter, Doreen; Hellwig, Michael; Henle, Thomas

    2013-10-30

    Methylglyoxal (MGO) is responsible for the pronounced antibacterial activity of manuka honey, in which it may reach concentrations up to 800 mg/kg. As MGO formed in vivo is discussed to play a role in diabetic complications, the metabolic transit of dietary MGO was studied within a 3 day dietary recall with four healthy volunteers. Determination of MGO in 24 h urine was performed with GC-MS after derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, and D-lactate was quantified enzymatically. Following a diet virtually free from MGO and other glycation compounds, a defined amount of MGO (500 μmol in manuka honey) was administered in the morning of day 2. Renal excretion was between 0.1 and 0.4 μmol/day for MGO and between 50 and 220 μmol/day for D-lactate. No influence on excretion of both compounds was observed following administration of MGO. To investigate the stability of MGO under physiological conditions, a simulated in vitro gastrointestinal digestion was performed with MGO-containing honey. After 8 h of in vitro digestion, only 5-20% of the initial methylglyoxal was recovered. This indicates that dietary MGO is rapidly degraded during the digestion process in the intestine and, therefore, exerts no influence on the MGO level in vivo. PMID:23451712

  4. Symmetry Guide to Ferroaxial Transitions

    NASA Astrophysics Data System (ADS)

    Hlinka, J.; Privratska, J.; Ondrejkovic, P.; Janovec, V.

    2016-04-01

    The 212 species of the structural phase transitions with a macroscopic symmetry breaking are inspected with respect to the occurrence of the ferroaxial order parameter, the electric toroidal moment. In total, 124 ferroaxial species are found, some of them being also fully ferroelectric (62) or fully ferroelastic ones (61). This ensures a possibility of electrical or mechanical switching of ferroaxial domains. Moreover, there are 12 ferroaxial species that are neither ferroelectric nor ferroelastic. For each species, we have also explicitly worked out a canonical form for a set of representative equilibrium property tensors of polar and axial nature in both high-symmetry and low-symmetry phases. This information was gathered into the set of 212 mutually different symbolic matrices, expressing graphically the presence of nonzero independent tensorial components and the symmetry-imposed links between them, for both phases simultaneously. Symmetry analysis reveals the ferroaxiality in several currently debated materials, such as VO2 , LuFe2 O4 , and URu2 Si2 .

  5. Fredericks transitions in biaxial nematics.

    PubMed

    Blinov, V N; Golo, V L; Kats, E I

    2015-07-01

    Much of our understanding (and applications) of biaxial nematic liquid crystals requires the study of the textural transformations in external electric or magnetic fields. To that end, one should employ theoretical approaches which could have bearing on the minimization problem of the multi-parametric free energy. The immediate shortcoming of the direct free-energy minimization (widely used for uniaxial nematics) is the need to resolve several non-linear constraints. To overcome this difficulty, in what follows we shall use the "angular velocity", which describes space rotations of the order parameter, and is in fact a vector internal curvature of the texture. This method provides a means to resolve the constraints imposed on the order parameter. Thus, we have obtained the set of equations to find all possible one-dimensional textures of biaxial nematics in the external field. To illustrate our method, we calculate the critical fields corresponding to some basic configurations for textural transitions in the biaxial nematics. We feel that this result could be useful to determine the intrinsic degree of biaxiality for liquid crystalline materials. PMID:26189196

  6. Phase transitions in semidefinite relaxations.

    PubMed

    Javanmard, Adel; Montanari, Andrea; Ricci-Tersenghi, Federico

    2016-04-19

    Statistical inference problems arising within signal processing, data mining, and machine learning naturally give rise to hard combinatorial optimization problems. These problems become intractable when the dimensionality of the data is large, as is often the case for modern datasets. A popular idea is to construct convex relaxations of these combinatorial problems, which can be solved efficiently for large-scale datasets. Semidefinite programming (SDP) relaxations are among the most powerful methods in this family and are surprisingly well suited for a broad range of problems where data take the form of matrices or graphs. It has been observed several times that when the statistical noise is small enough, SDP relaxations correctly detect the underlying combinatorial structures. In this paper we develop asymptotic predictions for several detection thresholds, as well as for the estimation error above these thresholds. We study some classical SDP relaxations for statistical problems motivated by graph synchronization and community detection in networks. We map these optimization problems to statistical mechanics models with vector spins and use nonrigorous techniques from statistical mechanics to characterize the corresponding phase transitions. Our results clarify the effectiveness of SDP relaxations in solving high-dimensional statistical problems. PMID:27001856

  7. A photometric search for transiting planets

    NASA Astrophysics Data System (ADS)

    Baliber, Nairn Reese

    In the decade since the discovery of the first planet orbiting a main-sequence star other than the Sun, more than 160 planets have been detected in orbit around other stars, most of them discovered by measuring the velocity of the reflexive motion of their parent stars caused by the gravitational pull of the planets. These discoveries produced a population of planets much different to the ones in our Solar System and created interest in other methods to detect these planets. One such method is searching for transits, the slight photometric dimming of stars caused by a close-orbiting, Jupiter-sized planet passing between a star and our line of sight once per orbit. We report results from TeMPEST, the Texas, McDonald Photometric Extrasolar Search for Transits, a transit survey conducted with the McDonald Observatory 0.76 m Prime Focus Corrector (PFC). We monitored five fields of stars in the plane of the Milky Way over the course of two and a half years. We created a photometry pipeline to perform high-precision differential photometry on all of the images, and used a software detection algorithm to detect transit signals in the light curves. Although no transits were found, we calculated our detection probability by determining the fraction of the stars monitored by TeMPEST which were suitable to show transits, measuring the probability of detecting transit signals based on the temporal coverage of our fields, and measuring our detection efficiency by inserting false transits into TeMPEST data to see what fraction could be recovered by our automatic detection software. We conclude that in our entire data set, we generated an effective sample of 2660 stars, a sample in which if any star is showing a transit, it would have been detected. We found no convincing transits in our data, but current statistics from radial velocity surveys indicate that only one in about 1300 of these stars should be showing transits. These numbers are consistent with the lack of transits produced by TeMPEST and the small number of transits generated by other surveys. We therefore discuss methods by which a transit survey's effective sample may be increased to make such surveys productive in a reasonable amount of time.

  8. Exploring structural phase transitions of ion crystals

    NASA Astrophysics Data System (ADS)

    Yan, L. L.; Wan, W.; Chen, L.; Zhou, F.; Gong, S. J.; Tong, X.; Feng, M.

    2016-02-01

    Phase transitions have been a research focus in many-body physics over past decades. Cold ions, under strong Coulomb repulsion, provide a repealing paradigm of exploring phase transitions in stable confinement by electromagnetic field. We demonstrate various conformations of up to sixteen laser-cooled 40Ca+ ion crystals in a home-built surface-electrode trap, where besides the usually mentioned structural phase transition from the linear to the zigzag, two additional phase transitions to more complicated two-dimensional configurations are identified. The experimental observation agrees well with the numerical simulation. Heating due to micromotion of the ions is analysed by comparison of the numerical simulation with the experimental observation. Our investigation implies very rich and complicated many-body behaviour in the trapped-ion systems and provides effective mechanism for further exploring quantum phase transitions and quantum information processing with ultracold trapped ions.

  9. Exploring structural phase transitions of ion crystals

    PubMed Central

    Yan, L. L.; Wan, W.; Chen, L.; Zhou, F.; Gong, S. J.; Tong, X.; Feng, M.

    2016-01-01

    Phase transitions have been a research focus in many-body physics over past decades. Cold ions, under strong Coulomb repulsion, provide a repealing paradigm of exploring phase transitions in stable confinement by electromagnetic field. We demonstrate various conformations of up to sixteen laser-cooled 40Ca+ ion crystals in a home-built surface-electrode trap, where besides the usually mentioned structural phase transition from the linear to the zigzag, two additional phase transitions to more complicated two-dimensional configurations are identified. The experimental observation agrees well with the numerical simulation. Heating due to micromotion of the ions is analysed by comparison of the numerical simulation with the experimental observation. Our investigation implies very rich and complicated many-body behaviour in the trapped-ion systems and provides effective mechanism for further exploring quantum phase transitions and quantum information processing with ultracold trapped ions. PMID:26865229

  10. Diagonal-transition quantum cascade detector

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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 μm at room-temperature by almost an order of magnitude.

  11. Exploring structural phase transitions of ion crystals.

    PubMed

    Yan, L L; Wan, W; Chen, L; Zhou, F; Gong, S J; Tong, X; Feng, M

    2016-01-01

    Phase transitions have been a research focus in many-body physics over past decades. Cold ions, under strong Coulomb repulsion, provide a repealing paradigm of exploring phase transitions in stable confinement by electromagnetic field. We demonstrate various conformations of up to sixteen laser-cooled (40)Ca(+) ion crystals in a home-built surface-electrode trap, where besides the usually mentioned structural phase transition from the linear to the zigzag, two additional phase transitions to more complicated two-dimensional configurations are identified. The experimental observation agrees well with the numerical simulation. Heating due to micromotion of the ions is analysed by comparison of the numerical simulation with the experimental observation. Our investigation implies very rich and complicated many-body behaviour in the trapped-ion systems and provides effective mechanism for further exploring quantum phase transitions and quantum information processing with ultracold trapped ions. PMID:26865229

  12. Practice transitions--past, present, and future.

    PubMed

    Prokes, Ronald I

    2014-01-01

    Until the 1960s, the value of a practice upon the retirement of the dentist was considered to be nil. In the next several decades, the value of a practice as a going business concern was recognized and formulas based on productivity were used to establish the sales price of "walkaway" practice transitions. Increasingly creative means, such as pre-sale, deferred pre-sale, shareholder process, incremental practice sale, and practice mergers have been created to make practice transitions more flexible, thereby maximizing the financial value of transitions. Dentists at the beginning of their careers will have an increasing range of opportunities in the future, with various combinations of financial security, freedom from manage- ment concerns, control over the practice, and accumulation of equity. Those in the 45- to 55-year age range should be planning in detail for their transition. Those older than 55 should begin exercising their plans since the future will involve much longer transitions. PMID:25975123

  13. Detection of Terrestrial Planets Using Transit Photometry

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  14. Vibrational overtone stretching transitions in sarin

    NASA Astrophysics Data System (ADS)

    Petryk, Michael W. P.

    2006-10-01

    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.

  15. Stainless steel to titanium bimetallic transitions

    NASA Astrophysics Data System (ADS)

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-12-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented. Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.

  16. Polarity transition records and the geomagnetic dynamo.

    PubMed

    Hoffman, K A

    1977-06-17

    The Parker-Levy approach to reversals of the geomagnetic field predicts meridional transitional paths of the virtual geomagnetic pole (VGP) which pass either through the site of observation or through its antipode, depending upon the site location and the sense of the polarity transition. Comparison with the most detailed transitional VGP path records presently available gives some indication of the above behavior as predicted by the Parker-Levy model. Discrepancies may be due to complexities in the distribution of cyclonic convection cells in the core not considered in the formal mathematical treatment. The predicted variation in transitional field intensity experienced at any given site also is compatible with several reported transition records. PMID:17831750

  17. Stainless Steel to Titanium Bimetallic Transitions

    SciTech Connect

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  18. Diagonal-transition quantum cascade detector

    SciTech Connect

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

    2014-09-01

    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 μm at room-temperature by almost an order of magnitude.

  19. Aging China -- policies in transition.

    PubMed

    Nusberg, C

    1987-01-01

    The International Forum on Aging was held in Beijing, China, in May of 1986 under the joint sponsorship of the Gerontological Society of America and the Chinese National Committee on Aging. 24 Chinese and American participants were also joined by experts from Canada, Australia, Hong Kong, Thailand, and Japan. Older persons in the West are by and large economically independent of their children and live in separate households. Nevertheless, both in the US and China families remain the preferred source of support for older persons. As a result of successful family planning policies, China will undergo a demographic transition in several decades that took a century in the West. This will result in the decline in the network of relatives, on which China's family support system has rested. Societal adjustments will have to be made including expanded joint ventures among government, families, neighborhoods, and collectives to provide for the old preferably in their own homes. The elderly will also participate more in economic and social development because of improved health, higher education, and declines in co-residency. For instance, an association of retired engineers in Chongqing has assisted over 6000 groups since 1980 through technical consultation for small enterprises in towns and rural areas. In 1987 only 6% of the rural population received some kind of pension, but policy makers envisage several different forms of social security schemes for the rural elderly. China's elderly population over 60 is projected to increase from 130 million in 2000 to 370 million in 2050, or from 11% to 26% of the total population. A Japanese model worth examining by China is the practice of combined occupation household, which permits rural areas to modernize while preserving the three-generation family household. The elderly continue to perform agricultural work on family property, while the younger family members take jobs in more urbanized nearby areas. PMID:12291355

  20. 23 CFR 810.204 - Application by mass transit authority.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Application by mass transit authority. 810.204 Section... MASS TRANSIT AND SPECIAL USE HIGHWAY PROJECTS Making Highway Rights-of-Way Available for Mass Transit Projects § 810.204 Application by mass transit authority. A publicly-owned mass transit authority...