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1. Femtosecond temperature measurements of laser-shocked copper deduced from the intensity of the x-ray thermal diffuse scattering

Author

Wark, J. S., Peake, D. J., Stevens, T., Heighway, P. G., Ping, Y., Sterne, P., Albertazzi, B., Ali, S. J., Antonelli, L., Armstrong, M. R., Baehtz, C., Ball, O. B., Banerjee, S., Belonoshko, A. B., Bolme, C. A., Bouffetier, V., Briggs, R., Buakor, K., Butcher, T., Cafiso, S. Di Dio, Cerantola, V., Chantel, J., Di Cicco, A., Coleman, A. L., Collier, J., Collins, G., Comley, A. J., Coppari, F., Cowan, T. E., Cristoforetti, G., Cynn, H., Descamps, A., Dorchies, F., Duff, M. J., Dwivedi, A., Edwards, C., Eggert, J. H., Errandonea, D., Fiquet, G., Galtier, E., Garcia, A. Laso, Ginestet, H., Gizzi, L., Gleason, A., Goede, S., Gonzalez, J. M., Gorman, M. G., Harmand, M., Hartley, N., Hernandez-Gomez, C., Higginbotham, A., Höppner, H., Humphries, O. S., Husband, R. J., Hutchinson, T. M., Hwang, H., Keen, D. A., Kim, J., Koester, P., Konopkova, Z., Kraus, D., Krygier, A., Labate, L., Lazicki, A. E., Lee, Y., Liermann, H-P., Mason, P., Masruri, M., Massani, B., McBride, E. E., McGuire, C., McHardy, J. D., McGonegle, D., McWilliams, R. S., Merkel, S., Morard, G., Nagler, B., Nakatsutsumi, M., Nguyen-Cong, K., Norton, A-M., Oleynik, I. I., Otzen, C., Ozaki, N., Pandolfi, S., Pelka, A., Pereira, K. A., Phillips, J. P., Prescher, C., Preston, T., Randolph, L., Ranjan, D., Ravasio, A., Redmer, R., Rips, J., Santamaria-Perez, D., Savage, D. J., Schoelmerich, M., Schwinkendorf, J-P., Singh, S., Smith, J., Smith, R. F., Sollier, A., Spear, J., Spindloe, C., Stevenson, M., Strohm, C., Suer, T-A., Tang, M., Toncian, M., Toncian, T., Tracy, S. J., Trapananti, A., Tschentscher, T., Tyldesley, M., Vennari, C. E., Vinci, T., Vogel, S. C., Volz, T. J., Vorberger, J., Willman, J. T., Wollenweber, L., Zastrau, U., Brambrink, E., Appel, K., and McMahon, M. I.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

We present 50-fs, single-shot measurements of the x-ray thermal diffuse scattering (TDS) from copper foils that have been shocked via nanosecond laser-ablation up to pressures above 135~GPa. We hence deduce the x-ray Debye-Waller (DW) factor, providing a temperature measurement. The targets were laser-shocked with the DiPOLE 100-X laser at the High Energy Density (HED) endstation of the European X-ray Free-Electron Laser (EuXFEL). Single x-ray pulses, with a photon energy of 18 keV, were scattered from the samples and recorded on Varex detectors. Despite the targets being highly textured (as evinced by large variations in the elastic scattering), and with such texture changing upon compression, the absolute intensity of the azimuthally averaged inelastic TDS between the Bragg peaks is largely insensitive to these changes, and, allowing for both Compton scattering and the low-level scattering from a sacrificial ablator layer, provides a reliable measurement of $T/\Theta_D^2$, where $\Theta_D$ is the Debye temperature. We compare our results with the predictions of the SESAME 3336 and LEOS 290 equations of state for copper, and find good agreement within experimental errors. We thus demonstrate that single-shot temperature measurements of dynamically compressed materials can be made via thermal diffuse scattering of XFEL radation., Comment: 17 pages, 9 figures in main article; 10 pages, 5 figures in supplementary material

Published
2025

4. Shock compression experiments using the DiPOLE 100-X laser on the high energy density instrument at the European x-ray free electron laser: Quantitative structural analysis of liquid Sn

Author

Gorman, M, Mcgonegle, D, Smith, R, Singh, S, Jenkins, T, Mcwilliams, R, Albertazzi, B, Ali, S, Antonelli, L, Armstrong, M, Baehtz, C, Ball, O, Banerjee, S, Belonoshko, A, Benuzzi-Mounaix, A, Bolme, C, Bouffetier, V, Briggs, R, Buakor, K, Butcher, T, Di Dio Cafiso, S, Cerantola, V, Chantel, J, Di Cicco, A, Clarke, S, Coleman, A, Collier, J, Collins, G, Comley, A, Coppari, F, Cowan, T, Cristoforetti, G, Cynn, H, Descamps, A, Dorchies, F, Duff, M, Dwivedi, A, Edwards, C, Eggert, J, Errandonea, D, Fiquet, G, Galtier, E, Laso Garcia, A, Ginestet, H, Gizzi, L, Gleason, A, Goede, S, Gonzalez, J, Harmand, M, Hartley, N, Heighway, P, Hernandez-Gomez, C, Higginbotham, A, Höppner, H, Husband, R, Hutchinson, T, Hwang, H, Lazicki, A, Keen, D, Kim, J, Koester, P, Konopkova, Z, Kraus, D, Krygier, A, Labate, L, Lee, Y, Liermann, H, Mason, P, Masruri, M, Massani, B, Mcbride, E, Mcguire, C, Mchardy, J, Merkel, S, Morard, G, Nagler, B, Nakatsutsumi, M, Nguyen-Cong, K, Norton, A, Oleynik, I, Otzen, C, Ozaki, N, Pandolfi, S, Peake, D, Pelka, A, Pereira, K, Phillips, J, Prescher, C, Preston, T, Randolph, L, Ranjan, D, Ravasio, A, Redmer, R, Rips, J, Santamaria-Perez, D, Savage, D, Schoelmerich, M, Schwinkendorf, J, Smith, J, Sollier, A, Spear, J, Spindloe, C, Stevenson, M, Strohm, C, Suer, T, Tang, M, Toncian, M, Toncian, T, Tracy, S, Trapananti, A, Tschentscher, T, Tyldesley, M, Vennari, C, Vinci, T, Vogel, S, Volz, T, Vorberger, J, Walsh, J, Wark, J, Willman, J, Wollenweber, L, Zastrau, U, Brambrink, E, Appel, K, Mcmahon, M, Gorman, M. G., McGonegle, D., Smith, R. F., Singh, S., Jenkins, T., McWilliams, R. S., Albertazzi, B., Ali, S. J., Antonelli, L., Armstrong, M. R., Baehtz, C., Ball, O. B., Banerjee, S., Belonoshko, A. B., Benuzzi-Mounaix, A., Bolme, C. A., Bouffetier, V., Briggs, R., Buakor, K., Butcher, T., Di Dio Cafiso, S., Cerantola, V., Chantel, J., Di Cicco, A., Clarke, S., Coleman, A. L., Collier, J., Collins, G. W., Comley, A. J., Coppari, F., Cowan, T. E., Cristoforetti, G., Cynn, H., Descamps, A., Dorchies, F., Duff, M. J., Dwivedi, A., Edwards, C., Eggert, J. H., Errandonea, D., Fiquet, G., Galtier, E., Laso Garcia, A., Ginestet, H., Gizzi, L., Gleason, A., Goede, S., Gonzalez, J. M., Harmand, M., Hartley, N. J., Heighway, P. G., Hernandez-Gomez, C., Higginbotham, A., Höppner, H., Husband, R. J., Hutchinson, T. M., Hwang, H., Lazicki, A. E., Keen, D. A., Kim, J., Koester, P., Konopkova, Z., Kraus, D., Krygier, A., Labate, L., Lee, Y., Liermann, H. -P., Mason, P., Masruri, M., Massani, B., McBride, E. E., McGuire, C., McHardy, J. D., Merkel, S., Morard, G., Nagler, B., Nakatsutsumi, M., Nguyen-Cong, K., Norton, A. -M., Oleynik, I. I., Otzen, C., Ozaki, N., Pandolfi, S., Peake, D. J., Pelka, A., Pereira, K. A., Phillips, J. P., Prescher, C., Preston, T. R., Randolph, L., Ranjan, D., Ravasio, A., Redmer, R., Rips, J., Santamaria-Perez, D., Savage, D. J., Schoelmerich, M., Schwinkendorf, J. -P., Smith, J., Sollier, A., Spear, J., Spindloe, C., Stevenson, M., Strohm, C., Suer, T. -A., Tang, M., Toncian, M., Toncian, T., Tracy, S. J., Trapananti, A., Tschentscher, T., Tyldesley, M., Vennari, C. E., Vinci, T., Vogel, S. C., Volz, T. J., Vorberger, J., Walsh, J. P. S., Wark, J. S., Willman, J. T., Wollenweber, L., Zastrau, U., Brambrink, E., Appel, K., McMahon, M. I., Gorman, M, Mcgonegle, D, Smith, R, Singh, S, Jenkins, T, Mcwilliams, R, Albertazzi, B, Ali, S, Antonelli, L, Armstrong, M, Baehtz, C, Ball, O, Banerjee, S, Belonoshko, A, Benuzzi-Mounaix, A, Bolme, C, Bouffetier, V, Briggs, R, Buakor, K, Butcher, T, Di Dio Cafiso, S, Cerantola, V, Chantel, J, Di Cicco, A, Clarke, S, Coleman, A, Collier, J, Collins, G, Comley, A, Coppari, F, Cowan, T, Cristoforetti, G, Cynn, H, Descamps, A, Dorchies, F, Duff, M, Dwivedi, A, Edwards, C, Eggert, J, Errandonea, D, Fiquet, G, Galtier, E, Laso Garcia, A, Ginestet, H, Gizzi, L, Gleason, A, Goede, S, Gonzalez, J, Harmand, M, Hartley, N, Heighway, P, Hernandez-Gomez, C, Higginbotham, A, Höppner, H, Husband, R, Hutchinson, T, Hwang, H, Lazicki, A, Keen, D, Kim, J, Koester, P, Konopkova, Z, Kraus, D, Krygier, A, Labate, L, Lee, Y, Liermann, H, Mason, P, Masruri, M, Massani, B, Mcbride, E, Mcguire, C, Mchardy, J, Merkel, S, Morard, G, Nagler, B, Nakatsutsumi, M, Nguyen-Cong, K, Norton, A, Oleynik, I, Otzen, C, Ozaki, N, Pandolfi, S, Peake, D, Pelka, A, Pereira, K, Phillips, J, Prescher, C, Preston, T, Randolph, L, Ranjan, D, Ravasio, A, Redmer, R, Rips, J, Santamaria-Perez, D, Savage, D, Schoelmerich, M, Schwinkendorf, J, Smith, J, Sollier, A, Spear, J, Spindloe, C, Stevenson, M, Strohm, C, Suer, T, Tang, M, Toncian, M, Toncian, T, Tracy, S, Trapananti, A, Tschentscher, T, Tyldesley, M, Vennari, C, Vinci, T, Vogel, S, Volz, T, Vorberger, J, Walsh, J, Wark, J, Willman, J, Wollenweber, L, Zastrau, U, Brambrink, E, Appel, K, Mcmahon, M, Gorman, M. G., McGonegle, D., Smith, R. F., Singh, S., Jenkins, T., McWilliams, R. S., Albertazzi, B., Ali, S. J., Antonelli, L., Armstrong, M. R., Baehtz, C., Ball, O. B., Banerjee, S., Belonoshko, A. B., Benuzzi-Mounaix, A., Bolme, C. A., Bouffetier, V., Briggs, R., Buakor, K., Butcher, T., Di Dio Cafiso, S., Cerantola, V., Chantel, J., Di Cicco, A., Clarke, S., Coleman, A. L., Collier, J., Collins, G. W., Comley, A. J., Coppari, F., Cowan, T. E., Cristoforetti, G., Cynn, H., Descamps, A., Dorchies, F., Duff, M. J., Dwivedi, A., Edwards, C., Eggert, J. H., Errandonea, D., Fiquet, G., Galtier, E., Laso Garcia, A., Ginestet, H., Gizzi, L., Gleason, A., Goede, S., Gonzalez, J. M., Harmand, M., Hartley, N. J., Heighway, P. G., Hernandez-Gomez, C., Higginbotham, A., Höppner, H., Husband, R. J., Hutchinson, T. M., Hwang, H., Lazicki, A. E., Keen, D. A., Kim, J., Koester, P., Konopkova, Z., Kraus, D., Krygier, A., Labate, L., Lee, Y., Liermann, H. -P., Mason, P., Masruri, M., Massani, B., McBride, E. E., McGuire, C., McHardy, J. D., Merkel, S., Morard, G., Nagler, B., Nakatsutsumi, M., Nguyen-Cong, K., Norton, A. -M., Oleynik, I. I., Otzen, C., Ozaki, N., Pandolfi, S., Peake, D. J., Pelka, A., Pereira, K. A., Phillips, J. P., Prescher, C., Preston, T. R., Randolph, L., Ranjan, D., Ravasio, A., Redmer, R., Rips, J., Santamaria-Perez, D., Savage, D. J., Schoelmerich, M., Schwinkendorf, J. -P., Smith, J., Sollier, A., Spear, J., Spindloe, C., Stevenson, M., Strohm, C., Suer, T. -A., Tang, M., Toncian, M., Toncian, T., Tracy, S. J., Trapananti, A., Tschentscher, T., Tyldesley, M., Vennari, C. E., Vinci, T., Vogel, S. C., Volz, T. J., Vorberger, J., Walsh, J. P. S., Wark, J. S., Willman, J. T., Wollenweber, L., Zastrau, U., Brambrink, E., Appel, K., and McMahon, M. I.

Abstract

X-ray free electron laser (XFEL) sources coupled to high-power laser systems offer an avenue to study the structural dynamics of materials at extreme pressures and temperatures. The recent commissioning of the DiPOLE 100-X laser on the high energy density (HED) instrument at the European XFEL represents the state-of-the-art in combining x-ray diffraction with laser compression, allowing for compressed materials to be probed in unprecedented detail. Here, we report quantitative structural measurements of molten Sn compressed to 85(5) GPa and ∼ 3500 K. The capabilities of the HED instrument enable liquid density measurements with an uncertainty of ∼ 1 % at conditions which are extremely challenging to reach via static compression methods. We discuss best practices for conducting liquid diffraction dynamic compression experiments and the necessary intensity corrections which allow for accurate quantitative analysis. We also provide a polyimide ablation pressure vs input laser energy for the DiPOLE 100-X drive laser which will serve future users of the HED instrument.

Published
2024

6. High‐Pressure Melting Experiments of Fe3C and a Thermodynamic Model of Fe‐C Liquids for the Earth's Core.

Author

Komabayashi, T., McGuire, C., Thompson, S., Bromiley, G. D., Bravenec, A., and Pakhomova, A.

Subjects
*EARTH'S core, *SEISMIC wave velocity, *LIQUID iron, *GIBBS' free energy, *MELTING points, *SEISMIC waves
Abstract

Melting experiments of Fe3C were conducted to 85 GPa in laser‐heated diamond anvil cells with in situ X‐ray diffraction and post‐experiment textural observation. From the determined pressure‐temperature conditions of the melting curve for Fe3C, together with literature data on the melting point of diamond and eutectic point of the system Fe‐Fe3C/Fe7C3 under high pressures, we established a self‐consistent thermodynamic model for high‐pressure melting of the system Fe‐C including the mixing parameters for liquids. The results show that mixing of Fe and C liquids is negatively nonideal from 1 bar to the pressure at the center of the Earth. The departure from ideal mixing becomes progressively larger with increasing pressure, which leads to greatly stabilized liquids under core pressures. The modeled carbon content in eutectic melts under core pressures is 3.3–4.4 wt%. From the Gibbs free energy, we derived an internally consistent parameters for Fe‐C outer cores which included the crystallizing points at their bottoms, isentropic thermal profiles, and densities and longitudinal seismic wave speeds (Vp). While the addition of carbon in excess of the eutectic melt composition effectively reduces the density of iron liquid, the Vp of iron liquid is not greatly changed. Therefore, the low density and high Vp of PREM relative to pure iron cannot be reconciled by an Fe‐C liquid. Therefore, the Earth's core cannot be approximated by the system Fe‐C and should include another light element. Plain Language Summary: The presence or absence of carbon in the Earth's central core has long been discussed in order to account for the observed core density lower than iron because the identification of such light elements in the core will provide critical information about the origin and evolution of the solid Earth. The relevance of carbon in the Earth's core is testable by comparing the density and seismic wave velocities of candidate Fe‐C materials with observations. Here we present a new experiment‐based thermodynamic model for the system Fe‐C. We first determined the melting points of Fe3C to 85 GPa. We then assessed thermodynamic parameters of Fe‐C liquids, from the constrained pressure‐temperature conditions of the melting curve for Fe3C, together with literature data. From the established model, we consistently computed the properties of hypothetical Fe‐C liquid outer cores including the density and longitudinal seismic wave velocity. While a carbon concentration greater than 4 wt% effectively reduces the density of iron liquid, the seismic velocity is not greatly changed, and therefore carbon cannot reconcile the low density and high velocity nature of the Earth's outer core. Therefore, the Earth's core cannot be approximated by the system Fe‐C and should include another light element. Key Points: Melting experiments of Fe3C were conducted to 85 GPa in diamond anvil cells with in situ X‐ray diffraction and textural observationA thermodynamic model for melting of the system Fe‐C which is applicable to the center of the Earth was establishedThe Earth's core cannot be approximated by the system Fe‐C and should include another light element [ABSTRACT FROM AUTHOR]

Published
2024
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7. Interframe-tunable ultrafast differential-displacement holography.

Author

Hutchinson, T. M., Righi, G., Celliers, P. M., Ali, S. J., McGuire, C. P., Perez, T., and Rasmus, A. M.

Subjects
HOLOGRAPHY, MULTIPLEXING, VELOCITY, TOPOGRAPHY, DIGITAL holographic microscopy
Abstract

We describe the details of a digital holographic microscopy diagnostic capable of quantifying both the topography and velocity of a km/s object with adjustable temporal sensitivity. This technique involves spatially multiplexing a double pulse reflected from a target with reference beams of precisely known temporal separation. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Shock compression experiments using the DiPOLE 100-X laser on the high energy density instrument at the European x-ray free electron laser: Quantitative structural analysis of liquid Sn

Author

Gorman, M. G., primary, McGonegle, D., additional, Smith, R. F., additional, Singh, S., additional, Jenkins, T., additional, McWilliams, R. S., additional, Albertazzi, B., additional, Ali, S. J., additional, Antonelli, L., additional, Armstrong, M. R., additional, Baehtz, C., additional, Ball, O. B., additional, Banerjee, S., additional, Belonoshko, A. B., additional, Benuzzi-Mounaix, A., additional, Bolme, C. A., additional, Bouffetier, V., additional, Briggs, R., additional, Buakor, K., additional, Butcher, T., additional, Di Dio Cafiso, S., additional, Cerantola, V., additional, Chantel, J., additional, Di Cicco, A., additional, Clarke, S., additional, Coleman, A. L., additional, Collier, J., additional, Collins, G. W., additional, Comley, A. J., additional, Coppari, F., additional, Cowan, T. E., additional, Cristoforetti, G., additional, Cynn, H., additional, Descamps, A., additional, Dorchies, F., additional, Duff, M. J., additional, Dwivedi, A., additional, Edwards, C., additional, Eggert, J. H., additional, Errandonea, D., additional, Fiquet, G., additional, Galtier, E., additional, Laso Garcia, A., additional, Ginestet, H., additional, Gizzi, L., additional, Gleason, A., additional, Goede, S., additional, Gonzalez, J. M., additional, Harmand, M., additional, Hartley, N. J., additional, Heighway, P. G., additional, Hernandez-Gomez, C., additional, Higginbotham, A., additional, Höppner, H., additional, Husband, R. J., additional, Hutchinson, T. M., additional, Hwang, H., additional, Lazicki, A. E., additional, Keen, D. A., additional, Kim, J., additional, Koester, P., additional, Konopkova, Z., additional, Kraus, D., additional, Krygier, A., additional, Labate, L., additional, Lee, Y., additional, Liermann, H.-P., additional, Mason, P., additional, Masruri, M., additional, Massani, B., additional, McBride, E. E., additional, McGuire, C., additional, McHardy, J. D., additional, Merkel, S., additional, Morard, G., additional, Nagler, B., additional, Nakatsutsumi, M., additional, Nguyen-Cong, K., additional, Norton, A.-M., additional, Oleynik, I. I., additional, Otzen, C., additional, Ozaki, N., additional, Pandolfi, S., additional, Peake, D. J., additional, Pelka, A., additional, Pereira, K. A., additional, Phillips, J. P., additional, Prescher, C., additional, Preston, T. R., additional, Randolph, L., additional, Ranjan, D., additional, Ravasio, A., additional, Redmer, R., additional, Rips, J., additional, Santamaria-Perez, D., additional, Savage, D. J., additional, Schoelmerich, M., additional, Schwinkendorf, J.-P., additional, Smith, J., additional, Sollier, A., additional, Spear, J., additional, Spindloe, C., additional, Stevenson, M., additional, Strohm, C., additional, Suer, T.-A., additional, Tang, M., additional, Toncian, M., additional, Toncian, T., additional, Tracy, S. J., additional, Trapananti, A., additional, Tschentscher, T., additional, Tyldesley, M., additional, Vennari, C. E., additional, Vinci, T., additional, Vogel, S. C., additional, Volz, T. J., additional, Vorberger, J., additional, Walsh, J. P. S., additional, Wark, J. S., additional, Willman, J. T., additional, Wollenweber, L., additional, Zastrau, U., additional, Brambrink, E., additional, Appel, K., additional, and McMahon, M. I., additional

Published
2024
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11. The SAGE-Spec Spitzer Legacy program: The life-cycle of dust and gas in the Large Magellanic Cloud. Point source classification I

Author

Woods, Paul M., Oliveira, J. M., Kemper, F., van Loon, J. Th., Sargent, B. A., Matsuura, M., Szczerba, R., Volk, K., Zijlstra, A. A., Sloan, G. C., Lagadec, E., McDonald, I., Jones, O., Gorjian, V., Kraemer, K. E., Gielen, C., Meixner, M., Blum, R. D., Sewiło, M., Riebel, D., Shiao, B., Chen, C. -H. R., Boyer, M. L., Indebetouw, R., Antoniou, V., Bernard, J. -P., Cohen, M., Dijkstra, C., Galametz, M., Galliano, F., Gordon, Karl D., Harris, J., Hony, S., Hora, J. L., Kawamura, A., Lawton, B., Leisenring, J. M., Madden, S., Marengo, M., McGuire, C., Mulia, A. J., O'Halloran, B., Olsen, K., Paladini, R., Paradis, D., Reach, W. T., Rubin, D., Sandstrom, K., Soszyński, I., Speck, A. K., Srinivasan, S., Tielens, A. G. G. M., van Aarle, E., Van Dyk, S. D., Van Winckel, H., Vijh, Uma P., Whitney, B., and Wilkins, A. N.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

We present the classification of 197 point sources observed with the Infrared Spectrograph in the SAGE-Spec Legacy program on the Spitzer Space Telescope. We introduce a decision-tree method of object classification based on infrared spectral features, continuum and spectral energy distribution shape, bolometric luminosity, cluster membership, and variability information, which is used to classify the SAGE-Spec sample of point sources. The decision tree has a broad application to mid-infrared spectroscopic surveys, where supporting photometry and variability information are available. We use these classifications to make deductions about the stellar populations of the Large Magellanic Cloud and the success of photometric classification methods. We find 90 asymptotic giant branch (AGB) stars, 29 young stellar objects, 23 post-AGB objects, 19 red supergiants, eight stellar photospheres, seven background galaxies, seven planetary nebulae, two HII regions and 12 other objects, seven of which remain unclassified., Comment: (43 pages, 21 figures, 4 tables including one large table out of order; to be published in MNRAS)

Published
2010
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12. The SAGE-Spec Spitzer Legacy program: The life-cycle of dust and gas in the Large Magellanic Cloud

Author

Kemper, F., Woods, Paul M., Antoniou, V., Bernard, J. -P., Blum, R. D., Boyer, M. L., Chan, J., Chen, C. -H. R., Cohen, M., Dijkstra, C., Engelbracht, C., Galametz, M., Galliano, F., Gielen, C., Gordon, Karl D., Gorjian, V., Harris, J., Hony, S., Hora, J. L., Indebetouw, R., Jones, O., Kawamura, A., Lagadec, E., Lawton, B., Leisenring, J. M., Madden, S. C., Marengo, M., Matsuura, M., McDonald, I., McGuire, C., Meixner, M., Mulia, A. J., O'Halloran, B., Oliveira, J. M., Paladini, R., Paradis, D., Reach, W. T., Rubin, D., Sandstrom, K., Sargent, B. A., Sewilo, M., Shiao, B., Sloan, G. C., Speck, A. K., Srinivasan, S., Szczerba, R., Tielens, A. G. G. M., van Aarle, E., Van Dyk, S. D., van Loon, J. Th., Van Winckel, H., Vijh, Uma P., Volk, K., Whitney, B. A., Wilkins, A. N., and Zijlstra, A. A.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The SAGE-Spec Spitzer Legacy program is a spectroscopic follow-up to the SAGE-LMC photometric survey of the Large Magellanic Cloud carried out with the Spitzer Space Telescope. We present an overview of SAGE-Spec and some of its first results. The SAGE-Spec program aims to study the life cycle of gas and dust in the Large Magellanic Cloud, and to provide information essential to the classification of the point sources observed in the earlier SAGE-LMC photometric survey. We acquired 224.6 hours of observations using the InfraRed Spectrograph and the SED mode of the Multiband Imaging Photometer for Spitzer. The SAGE-Spec data, along with archival Spitzer spectroscopy of objects in the Large Magellanic Cloud, are reduced and delivered to the community. We discuss the observing strategy, the specific data reduction pipelines applied and the dissemination of data products to the scientific community. Initial science results include the first detection of an extragalactic "21 um" feature towards an evolved star and elucidation of the nature of disks around RV Tauri stars in the Large Magellanic Cloud. Towards some young stars, ice features are observed in absorption. We also serendipitously observed a background quasar, at a redshift of z~0.14, which appears to be host-less., Comment: 33 pages, 12 figures, 8 tables; accepted for publication by PASP

Published
2010
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13. Epitaxial Graphene Growth on SiC Wafers

Author

Gaskill, D. Kurt, Jernigan, Glenn G., Campbell, Paul M., Tedesco, Joseph L., Culbertson, James C., VanMil, Brenda L., Myers-Ward, Rachael L., Eddy, Jr., Charles R., Moon, Jeong, Curtis, D., Hu, M., Wong, D., McGuire, C., Robinson, Joshua A., Fanton, Mark A., Stitt, Joseph P., Stitt, Thomas, Snyder, David, Weng, Xiaojun, and Frantz, Eric

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

An in vacuo thermal desorption process has been accomplished to form epitaxial graphene (EG) on 4H- and 6H-SiC substrates using a commercial chemical vapor deposition reactor. Correlation of growth conditions and the morphology and electrical properties of EG are described. Raman spectra of EG on Si-face samples were dominated by monolayer thickness. This approach was used to grow EG on 50 mm SiC wafers that were subsequently fabricated into field effect transistors with fmax of 14 GHz., Comment: 215th Meeting of the Electrochemical Society, 8 pages, 8 figures

Published
2009
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14. Implications of the loess record for Holocene climate and human settlement in Heye Catchment, Jiuzhaigou, eastern Tibetan Plateau, Sichuan, China

Author

Smith, AH, Collins, BD, Keen-Zebert, A, d'Alpoim Guedes, J, Hein, A, Womack, A, McGuire, C, Feathers, J, Persico, L, Fiallo, D, Tang, Y, and Simonson, B

Subjects
Arts and Humanities (miscellaneous), General Earth and Planetary Sciences, Earth-Surface Processes
Abstract

We examine the Holocene loess record in the Heye Catchment on the margins of the Tibetan Plateau (TP) and China Loess Plateau (CLP) to determine: the region to which the Heye Catchment climate is more similar; temporal change in wind strength; and modification of the loess record by mass wasting and human activity. Luminescence and radiocarbon dating demonstrate loess deposited in two periods: >11–8.6 ka and

Published
2022
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18. Narrowing the Achievement Gap in a (Re) Segregated Urban School District: Research, Policy and Practice. The Achievement Gap, Research, Practice, and Policy

Author

Ikpa, Vivian W., McGuire, C. Kent, Ikpa, Vivian W., and McGuire, C. Kent

Abstract

The interplay between sociopolitical forces and economic agendas becomes apparent when one examines the June 28, 2007 United States Supreme Court Decision, Parents Involved In Community Schools v. Seattle School District . In a reversal of the 1954 Brown Decision, the United States Supreme Court ruled that public schools could not use race as a factor when assigning children to public schools. Given demographic shifts, globalization, economic instability, and ideological shifts, the reversal was expected. However, it is essential that policymakers, educators, and other stakeholders consider the impact of attending segregated schools on the achievement gap that continues to exist between minority groups and European Americans attending resegregated neighborhood schools. This book will focus on the test score gaps between African American and European American students. The achievement gaps between these two groups will be analyzed will be presented and elaborated. Additionally, the authors will analyze how changes in school characteristics such as: racial composition; school composition; school expenditures, and socio economic level of neighborhoods affect achievement gap trends in the Norfolk School District. An examination of the achievement gap trends in an urban school district will serve to better inform public policy and school reform efforts. The specific goals of this book are to describe the achievement gap between minority African-American students and European-American students in the Norfolk school district and to present strategies utilized by urban districts to narrow the gap. One unique feature of this book is that it provides a data-driven research-based analysis of the achievement gap between minority and European-American students. The following are contained in this book: (1) Introduction; (2) Urban Challenges and the Achievement Gap; (3) The Legal Battle to Desegregate Public Schools; (4) Virginia's Massive Resistance to Desegregation; (5) Achievement Gap Research; (6) Achievement Gaps and Resegregation in Norfolk; (7) The Achievement Gap in the Resegregated Norfolk City Schools District; and (8) Narrowing Achievement Gaps.

Published
2009

19. Agora: The Impact of High-Stakes Testing.

Author

O'Connell, P. J., McGuire, C. Kent, and Middleton, Richard

Abstract

Eight members of the education community (e.g., students, teachers, college faculty, and administrators) respond to a question about the impact of high-stakes testing of teachers and students on teaching and teacher education. Their responses focus on such issues as test bias, at-risk students, specific state responses, and testing of students with learning disabilities. (SM)

Published
2000

20. School Facilities and Deferred Maintenance. Issuegram 43.

Author

Education Commission of the States, Denver, CO. and McGuire, C. Kent

Abstract

School systems have been forced to postpone purchases of new equipment and to defer repair and renovation projects. At present, 39 states provide support for local school district capital expenditures through five primary mechnanisms: full state assumption, state/local sharing, state flat grant, state equalizing grant, and state loans. In response to high and volatile interest rates, increased competition within the municipal bond market, and reduced investor demand for tax-exempt securities, state policymakers might consider new ways of structuring tax-exempt bond issues that have the advantages of lower interest costs to issuers and of a broader potential market. However, state policymakers should be aware of the pros and cons of various creative financing techniques before modifying existing legislation to permit their use. (MLF)

Published
1983

21. School Finance Litigation. Issuegram 27.

Author

Education Commission of the States, Denver, CO. and McGuire, C. Kent

Abstract

This review of the history of school finance litigation highlights various rulings of the courts and the ways that legal strategies have changed over time. Originally the school finance cases were based on the equal protection clause of the Fourteenth Amendment to the U.S. Constitution, the argument being that differences in per pupil spending had to be related to differences in student need. This was rejected by the courts on the grounds that a clear standard for assessing the education needs of pupils did not exist. Litigation strategies then focused on inputs to the education process, arguing that differences in the abilities of school districts to provide resources diminished opportunities in poor school districts. The student-need argument has reemerged more recently, and state school finance systems are being challenged on the basis of failure to structure funding systems to guarantee a thorough and efficient or ample education for all. Reviews of recent court cases are included. (MD)

Published
1983

22. Programs for Special Student Populations. Issuegram 28.

Author

Education Commission of the States, Denver, CO. and McGuire, C. Kent

Abstract

Factors affecting the state role in financing educational programs for special student populations are examined along with potential state policy considerations related to the provision of special services. An outline of the major problems facing state policy makers, such as federal budget cuts, teacher shortages, and the needs of gifted and talented students, is followed by a list of suggestions for low-cost expansion of services. These suggestions include provision of small planning grants for local school districts, state assistance in identifying disadvantaged students, a school-based approach to funding special needs programs, relaxation of targeting requirements, and tying the distribution of funds to program performance standards. The paper concludes with a list of recommended reading. (LP)

Published
1983

23. Financing Educational Services for Special Populations: The State and Federal Roles. Working Paper in Education Finance No. 28.

Author

Education Commission of the States, Denver, CO. Education Finance Center., Odden, Allan, and McGuire, C. Kent

Abstract

Introducing this paper is a discussion of the trend during the 1960s and 1970s toward greater state and federal involvement both in financing and in developing programs for special pupil populations. The authors then summarize, as of the 1980 fiscal year, the state and federal roles in programs for the handicapped and in bilingual and compensatory education. The number of students served and the level of funding are noted. The information is presented for the purpose of developing policies to streamline the various programs administratively and making concrete suggestions as to the need for program and fiscal changes at both the state and federal levels. The authors argue that a full range of programs for special pupil populations is a matter of good human services policy and should be seen as an element of good education policy at both the state and federal levels. They argue further that a great deal of attention needs to be given to streamlining special programs at each level and across levels of government. The future issue is how all these programs merge at the classroom level and what is the best set of strategies for providing special services along with regular classroom educational services. (Author/IRT)

Published
1980

24. Tuition Tax Credits: Their Impact on the States

Author

Education Commission of the States, Denver, CO. Education Finance Center., Augenblick, John, and McGuire, C. Kent

Abstract

In an attempt to discover how regional differences result in variations in the benefit patterns of federal programs, this booklet examines how education tax credits would be distributed across states. Using a simulation model, alternative tax credit structures are examined and their regional distribution is compared to the current distribution of federal aid for elementary and secondary schools. What is shown is that some regions would benefit to a far greater extent than others, that private schools could possibly receive more federal support on a per pupil basis than public schools, and that the structure of the credit affects the level and distribution of benefits. (Author/JM)

Published
1982

25. State and Federal Programs for Special Student Populations.

Author

Education Commission of the States, Denver, CO. Education Finance Center. and McGuire, C. Kent

Abstract

Drawing on documentary data and surveys of state education officials, this report reviews current federal and state initiatives for disadvantaged, language-minority, and handicapped students in order to help states assess their options in light of the recent consolidation of federal education programs. The author notes different states' approaches and provides information on federal and state resources. Part 1 presents an overview of federal and state involvement in special-needs programs and discusses federal goals and objectives, state actions since 1965, and state financing mechanisms. Parts 2-4 cover federal and state programs and state funding approaches in compensatory, bilingual, and special education, respectively. State eligibility criteria for compensatory and special education programs are also examined in parts 2 and 4, while part 3 focuses on state legislation for bilingual programs. In the final part the author assembles national and state-by-state data on funding levels and analyzes past and future trends in federal and state support for special-needs programs. (Author/RW)

Published
1982

26. Investments in Education Reform: Has the Momentum Been Retained?

Author

Verstegen, Deborah A. and McGuire, C. Kent

Abstract

The central education policy question for the next several years is whether the state educational reform movement can be maintained. One concern in the development of education policy is whether the money necessary to accomplish these changes will be available. First, funding increases for education reform since 1983 are examined. Second, the percentage of specified reform dollars is compared, first to total state revenue and, second, to revenue from all sources, over time. Two major data sources were utilized for this study: (1) figures on reform expenditures were collected from the "National Education Association's Estimates of School Statistics, 1987-88"; (2) a questionnaire was sent to the finance director for each state department of education to determine new line-item funding and specific "education reform" funding. The data were then analyzed to determine how the states are funding the reforms they are legislating and recommending. Although many states enacted some form of increased graduation requirements and excellence policies, many of them set aside no additional aid for these measures. In conclusion, it is likely that education reform and education finance reform will be linked in an effort to achieve the tandem goals of equity and excellence in education. Endnotes, charts detailing state education reform initiatives and support, and state revenues allocated for education are appended. (LMS)

Published
1988

27. The State of State Education Finance--Emerging Themes and Collapsing Constraints.

Author

Verstegen, Deborah A. and McGuire, C. Kent

Abstract

New directions in federal educational policy in the 1980s have had clear and consistent implications for state education finance systems. This study reviews the financing arrangements that have emerged during the 1980s at the state level, discusses the costs of new legislative mandates and state programs, and assesses the extent to which federal programs associated with special populations have been taken over by the states and how these programs are funded. Data for the study were derived from U.S. investments in education during the past decade and reform expenditures by states, regions, and the nation, along with questionnaires sent to the finance directors in each state department of education. The following selected results of this data collection effort are reviewed: revenue sources for education from 1980 to the present; state financing of education excellence policies; state financing of special pupil populations; and current systems of revenue distribution across the United States. In addition, the climate of education in the current year is reviewed, and emerging themes and collapsing constraints in education finance policy are considered throughout. Extensive tables and charts are appended, and 62 references and notes are included. (TE)

Published
1988

28. The Costs of Performance Pay Systems.

Author

Education Commission of the States, Denver, CO., McGuire, C. Kent, and Thompson, John A.

Abstract

This booklet examines the cost implications of reward-for-performance plans for teacher compensation. The growing acceptance of plans that recognize effective teaching with financial or other rewards is noted in the introduction, and some of the arguments against such plans are expressed. The first chapter reviews the origins and aims of the traditional single salary schedule and describes the kinds of modifications districts and states are making or proposing for the purpose of rewarding excellence. These plans include career ladders, multiple salary schedules, merit pay, extended contracts, and pay for extra work or work in critical subject areas. The second chapter discusses the factors affecting the costs of performance pay plans. In addition to the costs of the rewards themselves, administrators must consider the costs of planning the program and evaluating the teachers. It must also be realized that the costs of a program will include the costs associated with lowered morale and increased staff turnover if the program proves unsatisfactory to the teachers. In the third chapter, costs for two evaluation processes are compared and incorporated into simulations of merit pay and career ladder plans. The costs associated with extended contracts are also discussed. (PGD)

Published
1984

32. The Dialectic of Reform.

Author

Verstegen, Deborah and McGuire, C. Kent

Abstract

Critically examines current education reform, based on a 50-state survey. Studies state legislation passed since 1983 and investments in 1988 reforms in the context of current educational issues, highlighting areas for further research. Presents data on special populations. Future reforms will be cast in response to present-day emphases. Funding prospects are cloudy. (42 references) (MLH)

Published
1991

46. Equine squamous gastric disease and delayed gastric emptying – the chicken or the egg?

Author

Hewetson, M. and McGuire, C. J.

Subjects
*GASTRIC emptying, *GASTRIC diseases, *GASTRIC mucosa, *PYLORUS, *GASTROINTESTINAL motility
Abstract

Equine squamous gastric disease (ESGD), pyloric outflow obstruction and delayed gastric empty... Squamous gastric disease in horses is attributable to increased exposure of the squamous mucosa to acid and is comparable to gastric ulceration of the I pars oesophagea i in pigs and gastro-oesophageal reflux disease (GERD) in people. Affected horses do not appear to have difficulty emptying liquids from their stomach, and therefore, they rarely present with fluid distention of the stomach and do not develop secondary squamous gastric disease or gastro-oesophageal reflux. Keywords: horse; delayed gastric emptying; ESGD; EGGD; gastric dysmotility; gastroparesis EN horse delayed gastric emptying ESGD EGGD gastric dysmotility gastroparesis 460 466 7 08/04/22 20220901 NES 220901 The case report by Witt et al. (2022) in this issue of I Equine Veterinary Education i describes delayed gastric emptying in a foal secondary to squamous gastric disease. In man, gastric diverticula are classified as true diverticula which are congenital; and acquired "traction" diverticula which are thought to be caused by perigastric adhesions from concurrent diseases, such as peptic ulcer disease (Marano et al., 2013). gl Secondary squamous gastric disease is less common and occurs as a direct consequence of delayed gastric emptying. [Extracted from the article]

Published
2022
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