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31 results on '"Wan, W. C."'

1. Spatially resolved density and ionization measurements of shocked foams using x-ray fluorescence.

Author

MacDonald, M. J., Keiter, P. A., Montgomery, D. S., Scott, H. A., Biener, M. M., Fein, J. R., Fournier, K. B., Gamboa, E. J., Kemp, G. E., Klein, S. R., Kuranz, C. C., LeFevre, H. J., Manuel, M. J.-E., Wan, W. C., and Drake, R. P.

Subjects
DENSITOMETERS, FOAM, X-ray fluorescence, SPECTROMETERS, PHOTOLUMINESCENCE, PROPERTIES of cathode rays
Abstract

We present experiments at the Trident laser facility demonstrating the use of x-ray fluorescence (XRF) to simultaneously measure density, ionization state populations, and electron temperature in shocked foams. An imaging x-ray spectrometer obtained spatially resolved measurements of Ti K-a emission. Density profiles were measured from K-a intensity. Ti ionization state distributions and electron temperatures were inferred by fitting K-a spectra to spectra from CRETIN simulations. This work shows that XRF provides a powerful tool to complement other diagnostics to make equation of state measurements of shocked materials containing a suitable tracer element. [ABSTRACT FROM AUTHOR]

Published
2016
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2. Experimental study of energy transfer in double shell implosions

Author

Merritt, E. C., primary, Sauppe, J. P., additional, Loomis, E. N., additional, Cardenas, T., additional, Montgomery, D. S., additional, Daughton, W. S., additional, Wilson, D. C., additional, Kline, J. L., additional, Khan, S. F., additional, Schoff, M., additional, Hoppe, M., additional, Fierro, F., additional, Randolph, R. B., additional, Patterson, B., additional, Kuettner, L., additional, Sacks, R. F., additional, Dodd, E. S., additional, Wan, W. C., additional, Palaniyappan, S., additional, Batha, S. H., additional, Keiter, P. A., additional, Rygg, J. R., additional, Smalyuk, V., additional, Ping, Y., additional, and Amendt, P., additional

Published
2019
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4. Ablative stabilization of Rayleigh-Taylor instabilities resulting from a laser-driven radiative shock

Author

Huntington, C. M., primary, Shimony, A., additional, Trantham, M., additional, Kuranz, C. C., additional, Shvarts, D., additional, Di Stefano, C. A., additional, Doss, F. W., additional, Drake, R. P., additional, Flippo, K. A., additional, Kalantar, D. H., additional, Klein, S. R., additional, Kline, J. L., additional, MacLaren, S. A., additional, Malamud, G., additional, Miles, A. R., additional, Prisbrey, S. T., additional, Raman, K. S., additional, Remington, B. A., additional, Robey, H. F., additional, Wan, W. C., additional, and Park, H.-S., additional

Published
2018
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5. How high energy fluxes may affect Rayleigh–Taylor instability growth in young supernova remnants

Author

Kuranz, C. C., primary, Park, H.-S., additional, Huntington, C. M., additional, Miles, A. R., additional, Remington, B. A., additional, Plewa, T., additional, Trantham, M. R., additional, Robey, H. F., additional, Shvarts, D., additional, Shimony, A., additional, Raman, K., additional, MacLaren, S., additional, Wan, W. C., additional, Doss, F. W., additional, Kline, J., additional, Flippo, K. A., additional, Malamud, G., additional, Handy, T. A., additional, Prisbrey, S., additional, Krauland, C. M., additional, Klein, S. R., additional, Harding, E. C., additional, Wallace, R., additional, Grosskopf, M. J., additional, Marion, D. C., additional, Kalantar, D., additional, Giraldez, E., additional, and Drake, R. P., additional

Published
2018
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6. Shock-driven discrete vortex evolution on a high-Atwood number oblique interface

Author

Rasmus, A. M., primary, Di Stefano, C. A., additional, Flippo, K. A., additional, Doss, F. W., additional, Kline, J. L., additional, Hager, J. D., additional, Merritt, E. C., additional, Desjardins, T. R., additional, Wan, W. C., additional, Cardenas, T., additional, Schmidt, D. W., additional, Donovan, P. M., additional, Fierro, F., additional, Martinez, J. I., additional, Zingale, J. S., additional, and Kuranz, C. C., additional

Published
2018
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8. Study of shock waves and related phenomena motivated by astrophysics

Author

Drake, R P, primary, Keiter, P A, additional, Kuranz, C C, additional, Malamud, G, additional, Manuel, M, additional, Stefano, C A Di, additional, Gamboa, E J, additional, Krauland, C M, additional, MacDonald, M J, additional, Wan, W C, additional, Young, R P, additional, Montgomery, D S, additional, Stoeckl, C, additional, and Froula, D H, additional

Published
2016
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9. Measurements of the energy spectrum of electrons emanating from solid materials irradiated by a picosecond laser

Author

Di Stefano, C. A., Kuranz, C. C., Seely, J. F., Thomas, A. G. R., Drake, R. P., Keiter, P. A., Williams, G. J., Park, J., Chen, H., MacDonald, M. J., Rasmus, A. M., Wan, W. C., Pereira, N. R., Joglekar, A. S., McKelvey, A., Zhao, Z., Klein, S. R., Kemp, G. E., Jarrott, L. C., Krauland, C. M., Peebles, J., Westover, B., Di Stefano, C. A., Kuranz, C. C., Seely, J. F., Thomas, A. G. R., Drake, R. P., Keiter, P. A., Williams, G. J., Park, J., Chen, H., MacDonald, M. J., Rasmus, A. M., Wan, W. C., Pereira, N. R., Joglekar, A. S., McKelvey, A., Zhao, Z., Klein, S. R., Kemp, G. E., Jarrott, L. C., Krauland, C. M., Peebles, J., and Westover, B.

Abstract

In this work, we present the results of experiments observing the properties of the electron stream generated laterally when a laser irradiates a metal. We find that the directionality of the electrons is dependent upon their energies, with the higher-energy tail of the spectrum (similar to 1 MeV and higher) being more narrowly focused. This behavior is likely due to the coupling of the electrons to the electric field of the laser. The experiments are performed by using the Titan laser to irradiate a metal wire, creating the electron stream of interest. These electrons propagate to nearby spectator wires of differing metals, causing them to fluoresce at their characteristic K-shell energies. This fluorescence is recorded by a crystal spectrometer. By varying the distances between the wires, we are able to probe the divergence of the electron stream, while by varying the medium through which the electrons propagate (and hence the energy-dependence of electron attenuation), we are able to probe the energy spectrum of the stream. (C) 2015 AIP Publishing LLC.

Published
2015

11. Measurements of the energy spectrum of electrons emanating from solid materials irradiated by a picosecond laser

Author

Di Stefano, C. A., primary, Kuranz, C. C., additional, Seely, J. F., additional, Thomas, A. G. R., additional, Drake, R. P., additional, Keiter, P. A., additional, Williams, G. J., additional, Park, J., additional, Chen, H., additional, MacDonald, M. J., additional, Rasmus, A. M., additional, Wan, W. C., additional, Pereira, N. R., additional, Joglekar, A. S., additional, McKelvey, A., additional, Zhao, Z., additional, Klein, S. R., additional, Kemp, G. E., additional, Jarrott, L. C., additional, Krauland, C. M., additional, Peebles, J., additional, and Westover, B., additional

Published
2015
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12. Demonstration of x-ray fluorescence imaging of a high-energy-density plasma

Author

MacDonald, M. J., primary, Keiter, P. A., additional, Montgomery, D. S., additional, Biener, M. M., additional, Fein, J. R., additional, Fournier, K. B., additional, Gamboa, E. J., additional, Klein, S. R., additional, Kuranz, C. C., additional, LeFevre, H. J., additional, Manuel, M. J.-E., additional, Streit, J., additional, Wan, W. C., additional, and Drake, R. P., additional

Published
2014
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13. Turbulent amplification of magnetic fields in laboratory laser-produced shock waves

Author

Meinecke, J., primary, Doyle, H. W., additional, Miniati, F., additional, Bell, A. R., additional, Bingham, R., additional, Crowston, R., additional, Drake, R. P., additional, Fatenejad, M., additional, Koenig, M., additional, Kuramitsu, Y., additional, C. Kuranz, C., additional, Lamb, D. Q., additional, Lee, D., additional, MacDonald, M. J., additional, Murphy, C. D., additional, Park, H-S., additional, Pelka, A., additional, Ravasio, A., additional, Sakawa, Y., additional, Schekochihin, A. A., additional, Scopatz, A., additional, Tzeferacos, P., additional, Wan, W. C., additional, Woolsey, N. C., additional, Yurchak, R., additional, Reville, B., additional, and Gregori, G., additional

Published
2014
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14. Effect of Biochar on the Cracking of Tar from the Pyrolysis of a Pine Sawdust in a Fixed Bed Reactor.

Author

Zhang, Z. Z., Zhu, M. M., Liu, P. F., Wan, W. C., Zhou, W. X., Chan, Y. L., and Zhang, D. K.

Abstract

The effect of biochar on the cracking of the tar from pyrolysis of a pine sawdust was experimentally studied. The pine sawdust was pyrolyzed in a fixed bed reactor at 1123K with and without a pine sawdust biochar placed downstream of the pyrolysis process to crack the pyrolysis tar. The cracking temperatures tested were 923, 1023 and 1123K and the vapour residence times of the tar passing through the biochar studied were 0, 1.2, 2.3 and 3.8s. The pyrolysis liquid yield decreased and pyrolysis gas yield increased with increasing biochar cracking temperature and the vapour residence time. The main pyrolysis gases were H2, CO, CH4 and CO2. As the cracking temperature increased, the H2 yield increased while CH4 yield decreased. The CO concentration decreased when the cracking temperature increased from 973K to 1023K but then increased when the temperature continued to increase. The trend of the change of CO2 concentration as a function of the cracking temperature was opposite to that of CO. As the vapour residence time increased, the yields of H2 and CO2 increased while CH4 and CO yields decreased. [ABSTRACT FROM AUTHOR]

Published
2015
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18. Aggregation Quenching of Luminescence in Electroluminescent Conjugated Polymers

Author

Jakubiak, R., Collison, C. J., Wan, W. C., Rothberg, L. J., and Hsieh, B. R.

Abstract

We report measurements of photoluminescence from films of a soluble phenylenevinylene polymer that has prospective importance as the emissive material in light-emitting diodes. We show unambiguously that there is long-lived emission in this material due to excimers and estimate that the quantum yield for excimer formation is as high as 50%. Since excimers in this polymer largely decay nonradiatively at ambient temperature, their prominence serves to drastically reduce the possible efficiency of electroluminescent conjugated polymer devices.

Published
1999

19. Synthesis of Highly Phenylated Poly(p-phenylenevinylenes) via a Chlorine Precursor Route

Author

Hsieh, B. R., Wan, W. C., Yu, Y., Gao, Y., Goodwin, T. E., Gonzalez, S. A., and Feld, W. A.

Abstract

The synthesis of several highly phenylated poly(p-phenylenevinylene) (PPV) derivatives by a chlorine precursor route was investigated in order to understand its scope. Three 1,4-bis(chloromethyl)benzene monomers were prepared via a robust and versatile synthetic procedure involving the Diels−Alder reaction. In the presence of 1.1 equiv of potassium tert-butoxide, the monomers underwent 1,6-dehydrochlorination to form the respective xylylenes which underwent 1,6-polymerization to give the corresponding chlorine precursor polymers. The 1,6-polymerization mechanism of the highly phenylated monomers is discussed. Only one monomer gave a soluble precursor polymer while the other two gave insoluble precursor polymers. The soluble precursor polymer was deposited as thin films and then converted to the corresponding PPV derivative, which showed green photoluminesence and electroluminesence.

Published
1998

20. Halogen Precursor Route to Poly[(2,3-diphenyl-p-phenylene)vinylene] (DP-PPV):  Synthesis, Photoluminescence, Electroluminescence, and Photoconductivity

Author

Wan, W. C., Antoniadis, H., Choong, V. E., Razafitrimo, H., Gao, Y., Feld, W. A., and Hsieh, B. R.

Abstract

Thin films of poly[(2,3-diphenyl-p-phenylene)vinylene] (DP-PPV) have been prepared via a chlorine precursor route (CPR). This involves the polymerization of 1,4-bis(chloromethyl)-2,3-diphenylbenzene with 1.0 equiv of potassium tert-butoxide to give the chlorine precursor polymer of DP-PPV. The chlorine precursor was thermally converted at different temperatures to give DP-PPV with different degrees of conversion. The conversion process was monitored by in situ photoluminescent (PL) spectroscopy. The onset of conversion was about 150 °C, and full conversion could be achieved at 170−250 °C. The degree of conversion was a function of the heating temperature rather than the duration of heating. The fully converted DP-PPV showed lower photoconductivity and higher PL intensity than PPV. Although partially converted DP-PPV showed bright PL, we have not been able to observe its EL. The electroluminescence (EL) of the single layer ITO/DP-PPV/Mg and the bilayer ITO/DP-PPV/Alq3/Mg LED devices is also reported. A significant improvement in the quantum efficiency (up to 0.7% ph/el) and a reduction in the turn-on voltage of the device were found upon incorporation of the Alq3 layer. These observations suggest that Alq3 enhances the injection of electrons and also participates in the recombination process.

Published
1997

21. HOW EXPRESSIONS OF CLAUDIN-1 AND MMP-2 IN RETINOBLASTOMA CORRELATE WITH HISTOLOGICAL DIFFERENTIATION AND OPTIC NERVE INVASION.

Author

Wan WC, Jin XM, Zheng GY, Zhang FY, Lv Y, and Zhu Y

Subjects
Cell Differentiation, Child, Preschool, Claudin-1 physiology, Eye Neoplasms chemistry, Eye Proteins physiology, Female, Humans, Infant, Male, Matrix Metalloproteinase 2 physiology, Neoplasm Invasiveness, Neoplasm Proteins physiology, Optic Nerve pathology, Retinoblastoma chemistry, Claudin-1 analysis, Eye Neoplasms pathology, Eye Proteins analysis, Matrix Metalloproteinase 2 analysis, Neoplasm Proteins analysis, Optic Nerve chemistry, Retinoblastoma pathology
Abstract

Retinoblastoma is a commonly seen and dangerous intraocular malignant tumor in infants. Studies have found that Claudin-1 and MMP-2, whose expressions may be connected, play roles in tissues of retinoblastoma. In this study we analyze and discuss changes of Claudin-1 and MMP-2 expressions, and the correlation between the expressions and retinoblastoma histological differentiation and optic nerve invasion. MaxVisionTM was applied to detect expressions of Claudin-1 and MMP-2 in 45 samples of retinoblastoma and 15 paraffin-embedded samples of normal retina. The correlation between Claudin-1 expression and MMP-2 expression was analyzed based on chi-squared test and Spearman’s correlation test. Positive expressions of Claudin-1 in retinoblastoma were fewer than those in retina; higher positive expressions were found in differentiated tissues than in undifferentiated tissues; while compared to expressions in invasive optic nerves, Claudin-1 expressed more positively in optic nerves without invasion. As for MMP-2, its expressions were higher in retinoblastoma than in normal retina; undifferentiated tissues had higher positive expressions than differentiated tissues, which were not statistically significant; higher positive expressions were detected in invasive optic nerves. Thus, it could be concluded that the correlation between Claudin-1 expression and MMP-2 expression in retinoblastoma was negative. Expressions of Claudin-1 were positively related to histological differentiation and optic nerve invasion of retinoblastoma; while MMp-2 expression had negative correlation with histological differentiation and optic nerve invasion of retinoblastoma. Claudin-1 and MMP-2 played a negative role in the optic nerve invasion and tumor development of retinoblastoma.

Published
2015

22. Glandular odontogenic cyst: a case report.

Author

Lin CC, Chen CH, Lai S, Chen YK, Wan WC, Lu SY, Hong JM, and Lin LM

Subjects
Humans, Immunohistochemistry, Keratins analysis, Male, Middle Aged, Mandibular Neoplasms pathology, Odontogenic Cysts pathology
Abstract

Glandular odontogenic cyst (GOC) is an extremely rare lesion occurring in the jawbones. Sialo-odontogenic cyst was first described as a multicystic lesion resembling a botryoid odontogenic cyst (BOC) or a central mucoepidermoid carcinoma by Padayachee in 1987. In 1988, Gardner used the term "glandular odontogenic cyst" and considered it as a histologic variant of BOC. Most authors agreed that GOC was odontogenic because of the concurrent ball-like epithelial structure, ameloblastoma, squamous odontogenic tumor-like proliferation in its wall, or hyaline bodies in the epithelium lining. Recently, immunohistochemical studies of the cytokeratin profiles have also supported this concept. Its aggressive behavior and the recurrent tendency make it important. A new case of GOC in a 59-year-old male presented as a multilocular radiolucency in the anterior region of the mandible, invading the marrow space by epithelial islands is described with other clinicopathologic features and the literature is briefly discussed.

Published
2000

23. Existence of a gonadotropin-releasing hormone-like factor in the grass shrimp (black tiger prawn, Penaeus monodon)

Author

Fann MC, Wan WC, and Wang PS

Subjects
Acids, Animals, Chromatography, Gel, Ethanol, Hot Temperature, Liver metabolism, Pancreas metabolism, Penaeidae analysis, Peptide Hydrolases metabolism, Radioimmunoassay, Tissue Extracts metabolism, Gonadotropin-Releasing Hormone metabolism, Penaeidae metabolism
Abstract

The immunological and biological gonadotropin-releasing hormone (GnRH)-like activities in the acid extract of shrimp hepatopancreas (SHE) were studied. The immunological activity determined by a GnRH radioimmunoassay was 22.3 +/- 2.7 ng per ml of SHE. SHE increased luteinizing hormone (LH) release from rat anterior pituitary glands (APs) in vitro, and its biological activity was 42.9 +/- 28.5 ng per ml. No immunological activity was found in the acid extracts of eye ball, eye stalk, nerve and heart. These results suggest that the shrimp hepatopancreas has both immunological and biological GnRH-like activity.

Published
1990

24. The presence of a thyrotropin-releasing hormone-like factor in the grass shrimp (black tiger prawn, Penaeus monodon)

Author

Hsieh YS, Fann MC, Wan WC, and Wang PS

Subjects
Acids, Animals, Chromatography, Liver metabolism, Pancreas metabolism, Peptide Hydrolases metabolism, Radioimmunoassay, Tissue Extracts metabolism, Penaeidae metabolism, Thyrotropin-Releasing Hormone metabolism
Abstract

Immunoreactive (TRH) has been detected in acid and methanol extracts of hepatopancreas, in grass shrimp (black tiger prawn, Penaeus monodon). The evidence provided by the stimulation of thyrotropin (TSH) release from perfused rat anterior pituitary glands in vitro following the application of hepatopancreas extracts (SHE) reflected the presence of TRH-like substance in the shrimp. However, the molecular weight of the TRH-like substance estimated by gel filtration in SHE was greater than that of the synthetic TRH. Furthermore, other differences are also noted, e.g. TRH-like activity in SHE could not be completely neutralized by anti-TRH antiserum nor degraded in normal rat serum.

Published
1990

30. Simulatory hypothyroidism pituitary function in vitro: dynamics of TSH release after TRH stimulation in perifused rat hemipituitaries.

Author

Wan WC, Jang YC, Huang LY, Liao CF, and Yu JY

Subjects
Animals, Feedback, Male, Rats, Rats, Inbred Strains, Secretory Rate drug effects, Hypothyroidism physiopathology, Pituitary Gland, Anterior metabolism, Thyrotropin metabolism, Thyrotropin-Releasing Hormone pharmacology
Abstract

The production of immunoreactive TSH by hemipituitaries (Hps) to the stimulation of TRH in perifusion with negligible influence of the feedback of secretogogues and hormones was analysed. The stimulations were of long term continuous (3 hrs) and short term (15 min), with the dose levels of 1, 10 and 100 ng per ml of medium (for 3 hrs) or in 2 ml (for 15 min). The largest amount in production and the fastest rate in release of TSH found in present report is at 10 ng level. Only total TSH, in tissue plus in medium, after continuous TRH stimulation were dose-related, but not in release alone. We present herein an analysis of pituitary TSH production, in a perifusion system under steady TRH stimulation. This arrangement is believed to be a condition simulating hypothyroidism in pituitary level and suitable for study of the functions of the pituitary with hyperactivated thyrotrophs.

Published
1984

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