WorldWideScience

Sample records for ptf weekly sn

  1. PTF weekly SN discovery report, July 1, 2011

    Science.gov (United States)

    Gal-Yam, A.; Ben-Ami, S.; Sternberg, A.; Polishuk, D.; Arcavi, I.; Nugent, P.; Silverman, J.; Cenk, S. B.

    2011-06-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 17 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  2. PTF weekly SN discovery report, January 21, 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Arcavi, I.; Nugent, Peter; Kasliwal, M.; Walker, E.; Cao, Y.; Levitan, D.

    2012-01-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 13 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  3. PTF weekly SN discovery report, July 28, 2011

    Science.gov (United States)

    Gal-Yam, A.; Nugent, P.; Maguire, K.; Pan, Y.-C.; Sullivan, M.; Howell, A.

    2011-07-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 8 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  4. PTF weekly SN discovery report, August 13, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Xu, Dong; Nugent, Peter; Horesh, Assaf; Cao, Yi; Walker, Emma

    2011-08-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 8 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  5. PTF weekly SN discovery report, March 9, 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Nugent, Peter; Levitan, D.; Silverman, J.; Morgan, A.; Nugent, P.; Miller, A.; Pan, Y.-C.

    2012-03-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 11 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  6. PTF weekly SN discovery report, Sep. 2, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Xu, D.; Ben-Ami, S.; Arcavi, I.; Sternberg, A.; Nugent, Peter; Cao, Y.; Konidaris, N.; Levitan, D.; Maguire, K.; Pan, Y.-C.; Cenko, S. B.; Silverman, J.; Kandrashoff, T.; Bloom, J. S.; Walker, E.; Groot, P.

    2011-09-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 21 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  7. PTF weekly SN discovery report, July 21, 2011

    Science.gov (United States)

    Gal-Yam, A.; Yaron, O.; Arcavi, I.; Howell, A.; Nugen, P.

    2011-07-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 2 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  8. PTF weekly SN discovery report, December 31, 2011

    Science.gov (United States)

    Gal-Yam, A.; Arcavi, I.; Yaron, O.; Xu, D.; Nugent, P.; Pan, Y.-C.

    2011-12-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 5 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  9. PTF weekly SN discovery report, October 21, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Nugent, Peter; Cao, M.; Kasliwal, Y.; Sesar, Branimir; Sesar; Ptf

    2011-10-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 7 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  10. PTF weekly SN discovery report, August 27, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Xu, D.; Ben-Ami, S.; Arcavi, I.; Sternberg, A.; Nugent, Peter; Cao, Y.; Konidaris, N.; Levitan, D.; Maguire, K.; Pan, Y.-C.; Cenko, S. B.; Silverman, J.; Kandrashoff, T.; Bloom, J. S.; Walker, E.; Groot, P.

    2011-09-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 11 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  11. PTF weekly SN discovery report, July 8, 2011

    Science.gov (United States)

    Gal-Yam, A.; Nugen, P.

    2011-07-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 11 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  12. PTF weekly SN discovery report, February 4, 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Arcavi, I.; Nugent, Peter; Levitan, D.; Cao, Y.; Horesh, A.; Bellm, E.; Matheson, T.

    2012-02-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 20 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  13. PTF weekly SN discovery report, November 6, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, S.; Yaron, O.; Nugent, P.; Kasliwal, M.; Cao, Y.; Levitan, D.; Sesar, B.; Tandulkar, S.; Groot, P.; Filippenko, A. V.; Cenko, S. B.; Silverman, D. Kasen. J.; Kandrashoff, M.; Blanchard, P.; Foley, R.

    2011-11-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 15 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  14. PTF weekly SN discovery report, Sep. 9, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Arcavi, I.; Polishook, D.; Cao, Y.; Nugen, Peter

    2011-09-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 10 new spectroscopically confirmed supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  15. PTF weekly SN discovery report, August 6, 2011

    Science.gov (United States)

    Gal-Yam, A.; Xu, D.; Nugent, P.; Hsiao, E.; Levitan, D.; Maguire, K.; Pan, Y.-C.; Sullivan, M.; Groot, P.

    2011-08-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 10 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  16. PTF weekly SN discovery report, November 18, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Nugent, Peter; Hook, Isobel; Pan, Yen-Chen

    2011-11-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 6 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  17. PTF weekly SN discovery report, December 8, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Yaron, O.; Ben-Ami, S.; Nugent, P. E.; Groot, P.; Tandulkar, S.; Horesh, E. Bellm. A.; Cao, Y.; Levitan, D.; Sesar, B.; Hook, I.; Pan, Y.-C.; Kandrashoff, M.; Blanchard, P.; Silverman, J.; Cenko, S. B.; Miller, A.; Filippenko, A. V.; Clubb, K. I.

    2011-12-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 25 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  18. PTF weekly SN discovery report, Sep. 23, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Nugent, Peter

    2011-09-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 2 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  19. PTF weekly SN discovery report, July 15, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Nugent, Peter; Hsiao, Eric; Graham, Melissa

    2011-07-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 2 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  20. PTF weekly SN discovery report, October 1, 2011

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Xu, Dong; Nugent, Peter; Sesar, Branimir; Pan, Y.-C.; Silverman, J.; Cenko, S. B.; Filippenko, A.

    2011-10-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 11 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org).

  1. PTF weekly SN discovery report, May 29, 2012 (part 1)

    Science.gov (United States)

    Gal-Yam, Avishay; Yaron, O.; Ben-Ami, S.; Arcavi, I.; Nugent, P.; Cao, Y.; Perley, D.; Kulkarni, S.; Hook, I.; Pan, Y.-C.; Walker, E.; Cenko, S. B.; Silverman, J.; Clubb, K. I.; Miller, A.; Filippenko, A. V.; Parrent, J.; Graham, M.

    2012-05-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 33 new supernovae (in this 2-part telegram). PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  2. PTF weekly SN discovery report, May 29, 2012 (Part 2)

    Science.gov (United States)

    Gal-Yam, Avishay; Yaron, O.; Ben-Ami, S.; Arcavi, I.; Nugent, P.; Cao, Y.; Perley, D.; Kulkarni, S.; Hook, I.; Pan, Y.-C.; Walker, E.; Cenko, S. B.; Silverman, J.; Clubb, K. I.; Miller, A.; Filippenko, A. V.; Parrent, J.; Graham, M.

    2012-05-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 33 new supernovae in this 2-part telegram. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  3. PTF SN discovery report, April 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Arcavi, I.; Ben-Ami, S.; Yaron, O.; Nugent, P.; Levitam, D.; Simonian, G.; Sesar, B.; Cao, Y.; Horesh, A.; Bellm, E.; Silverman, J.; Miller, A.; Cenko, S. B.; Clubb, K. I.; Filippenko, A. V.; Shivvers, I.; Kasliwal, M.; Parrent, J.; Maguire, K.; Pan, Y.-C.

    2012-05-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 19 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  4. PTF SN discovery report, August 2012

    Science.gov (United States)

    Arcavi, Iair; Gal-Yam, A.; Ben-Ami, S.; Yaron, O.; Horesh, P. Nugent A.; Cao, Y.; Bellm, E.; Fynbo, J.; Wiis, J.; Olesen, J.; Engedal, L.; Larsen, A.; Kasliwal, M.; Pan, Y.-C.; Graham, M.; Parrent, J.; Quimby, R.; PTF Team

    2012-08-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 12 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  5. PTF SN discovery report, September 8, 2012

    Science.gov (United States)

    Gal-Yam, A.; Nugent, P.; Walker, E.; Cenko, S. B.; Fox, O.

    2012-09-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 8 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  6. PTF SN discovery report, July 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Arcavi, I.; Yaron, O.; Nugent, Peter; Sesar, B.; Cao, Y.; Silverman, J.; Clubb, K.; Filippenko, A. V.; Cenko, S. B.; Parrent, J.; Maguire, K.; Sullivan, M.

    2012-08-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 14 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  7. PTF SN discovery report, March 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Arcavi, I.; Ben-Ami, S.; Yaron, O.; Nugent, P.; Levitam, D.; Simonian, G.; Sesar, B.; Cao, Y.; Horesh, A.; Bellm, E.; Silverman, J.; Miller, A.; Cenko, S. B.; Clubb, K. I.; Filippenko, A. V.; Shivvers, I.; Kasliwal, M.; Parrent, J.; Maguire, K.; Pan, Y.-C.

    2012-05-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 26 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  8. PTF SN discovery report, October 9, 2012

    Science.gov (United States)

    Gal-Yam, A.; Nugent, P.; Cao, Y.; Levitan, D.; Hallinan, G.; Kyne, G.; Silverman, J.; Clubb, K.; Miller, A.; Fox, O.; Suzuki, N.; Quimby, R.

    2012-10-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 9 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  9. PTF SN discovery report, May-June 2012

    Science.gov (United States)

    Gal-Yam, Avishay; Ben-Ami, Sagi; Yaron, O.; Arcavi, I.; Nugent, Peter; Levitan, D.; Perley, D.; Kulkarni, S. R.; Sesar, B.; Cao, Y.; Bellm, E.; Barlow, T.; Silverman, J.; Clubb, K.; Miller, A.; Fox, O.; Pan, Y.-C.; Maguire, K.; Sullivan, M.; Walker, E.; Kasliwal, M.; White, C. J.; Graham, M.; Parrent, J.

    2012-07-01

    The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf/ ; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of 27 new supernovae. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  10. PTF discovers a young type IIn SN in NGC 151

    Science.gov (United States)

    Parrent, J.; Levitan, D.; Howell, A.; Thomas, R. C.; Nugent, P.; Sullivan, M.; Kasliwal, M.; Ofek, E. O.; Quimby, R.; Ben-Ami, S.; Xu, D.; Arcavi, I.; Gal-Yam, A.; Cenko, C. B.; Li, W.; Filippenko, A. V.

    2011-07-01

    The PTF (ATEL #1964, #3253; www.astro.caltech.edu/ptf; Law et al. 2009, PASP, 121, 1395; Rau et al. 2009, PASP, 121, 1334) reports the discovery of a new supernova in NGC 151. PTF discoveries are made by autonomous PTF software (Bloom et al. 2011, http://adsabs.harvard.edu/abs/2011arXiv1106.5491B ), as well as by the Galaxy Zoo Supernova Project (Smith et al. 2011, MNRAS, 412, 1309; http://supernova.galaxyzoo.org ).

  11. Early Radio and X-Ray Observations of the Youngest nearby Type Ia Supernova PTF 11kly (SN 2011fe)

    NARCIS (Netherlands)

    Horesh, Assaf; Kulkarni, S. R.; Fox, Derek B.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O.; Quimby, Robert; Gal-Yam, Avishay; Cenko, Bradley; de Bruyn, A. G.; Kamble, Atish; Wijers, Ralph A. M. J.; van der Horst, Alexander J.; Kouveliotou, Chryssa; Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate; Howell, D. Andrew; Nugent, Peter E.; Gehrels, Neil; Law, Nicholas M.; Poznanski, Dovi; Shara, Michael

    2012-01-01

    On 2011 August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby Type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion

  12. SN2010jp (PTF10aaxi): A Jet-Driven Type II Supernova

    CERN Document Server

    Smith, Nathan; Butler, Nat; Bloom, Joshua S; Kasliwal, Mansi M; Horesh, Assaf; Kulkarni, Shrinivas R; Law, Nicholas M; Nugent, Peter E; Ofek, Eran O; Poznanski, Dovi; Quimby, Robert M; Sesar, Branimir; Ben-Ami, Sagi; Arcavi, Iair; Gal-Yam, Avishay; Polishook, David; Xu, Dong; Yaron, Ofer; Frail, Dale A; Sullivan, Mark

    2011-01-01

    We present photometry and spectroscopy of the peculiar TypeII supernova (SN) 2010jp, also named PTF10aaxi. The light curve exhibits a linear decline with a relatively low peak absolute magnitude of only -15.9, and a low radioactive decay luminosity at late times that suggests a nickel mass below 0.003 $M_{\\odot}$. Spectra of SN2010jp display an unprecedented triple-peaked H$\\alpha$ line profile, showing: (1) a narrow (800 km/s) central component that suggests shock interaction with dense CSM; (2) high-velocity blue and red emission features centered at -12600 and +15400 km/s; and (3) broad wings extending from -22000 to +25000 km/s. These features persist during 100 days after explosion. We propose that this line profile indicates a bipolar jet-driven explosion, with the central component produced by normal SN ejecta and CSM interaction at mid latitudes, while the high-velocity bumps and broad line wings arise in a nonrelativistic bipolar jet. Two variations of the jet interpretation seem plausible: (1) A fas...

  13. Early Radio and X-Ray Observations of the Youngest Nearby Type Ia Supernova PTF 11kly (SN 2011fe)

    Science.gov (United States)

    Horesh, Assaf; Kulkarni, S. R.; Fox, Derek B.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O.; Quimby, Robert; Gal-Yam, Avishay; Cenko, S. Bradley; deBruyn, A. G.; Kamble, Atish; Wijers, Ralph A. M. J.; vanderHorst, Alexander J.; Kouveliotou, Chryssa; Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate; Howell, D. Andrew; Nugent, Peter E.; Gehrels, Neil; Law, Nicolas M.; Poznanski, Dovi; Shara, Michael

    2012-01-01

    On August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of M(raised dot) less than or equal to 10(exp -8) (w /100 kilometers per second ) solar mass yr(exp -1) from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations we would have to wait for a long time (decade or longer) in order to more meaningfully probe the circumstellar matter of Ia supernovae.

  14. Early radio and X-ray observations of the youngest nearby type Ia supernova PTF11kly (SN 2011fe)

    CERN Document Server

    Horesh, Assaf; Fox, Derek B; Carpenter, John; Kasliwal, Mansi M; Ofek, Eran O; Quimby, Robert; Gal-Yam, Avishay; Cenko, S Bradley; de Bruyn, A G; Kamble, Atish; Wijers, Ralph A M J; van der Horst, Alexander J; Kouveliotou, Chryssa; Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate; Nugent, Peter E; Gehrels, Neil; Law, Nicholas M; Poznanski, Dovi; Shara, Michael

    2011-01-01

    On August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of dM/dt<10^-8 (w/100 km/s) [M_solar/yr] from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main-sequence or sub-giant stars, including the popular supersoft channel. In view of the...

  15. VizieR Online Data Catalog: Photometry of SN 2013gh and iPTF13dge (Ferretti+, 2016)

    Science.gov (United States)

    Ferretti, R.; Amanullah, R.; Goobar, A.; Johansson, J.; Vreeswijk, P.; Butler, R. P.; Cao, Y.; Cenko, S. B.; Doran, G.; Filippenko, A. V.; Freeland, E.; Hosseinzadeh, G.; Howell, D. A.; Lundqvist, P.; Mattila, S.; Nordin, J.; Nugent, P. E.; Petrushevska, T.; Valenti, S.; Vogt, S.; Wozniak, P.

    2016-06-01

    Measured photometry of type Ia supernovae 2013gh and iPTF13dge are presented. Furthermore, the effective light-curve-width-corrected phase and the natural magnitude in specified filters have been computed. Thereby, the corresponding Galactic absorption (Ax_MW) and the filter corrections (Kx) to the corresponding rest-frame filter for SN 2011fe as described by Amanullah et al. (2015MNRAS.453.3300A) are presented. The corrected magnitude can be obtained as X-AXMW-KX. All corrections have been calculated after the SN 2011fe template has been reddened with the best-fit Fitzpatrick (1999PASP..111...63F) law, for each SN. Furthermore, the V magnitude and corrections for each phase phase are included. The V magnitude was either measured (M) or calculated (D) using the SNooPy model. The V magnitude is only shown for data points used in the colour analysis, with phases between -10 and +35-days. The corrected colour can be obtained as (X-AXMW-KX)-(V-AVMW-KV) and can be compared with the corresponding colour of SN 2011fe in order to study the reddening laws of the SNe. (3 data files).

  16. Constraints on the Progenitor System of the Type Ia Supernova SN 2011fe/PTF11kly

    CERN Document Server

    Li, Weidong; Podsiadlowski, Philipp; Miller, Adam A; Cenko, S Bradley; Jha, Saurabh W; Sullivan, Mark; Howell, D Andrew; Nugent, Peter E; Butler, Nathaniel R; Ofek, Eran O; Kasliwal, Mansi M; Richards, Joseph W; Stockton, Alan; Shih, Hsin-Yi; Bildsten, Lars; Shara, Michael M; Bibby, Joanne; Filippenko, Alexei V; Ganeshalingam, Mohan; Silverman, Jeffrey M; Kulkarni, S R; Law, Nicholas M; Poznanski, Dovi; Quimby, Robert M; McCully, Curtis; Patel, Brandon; Maguire, Kate

    2011-01-01

    Type Ia supernovae (SNe) serve as a fundamental pillar of modern cosmology, owing to their large luminosity and a well-defined relationship between light-curve shape and peak brightness. The precision distance measurements enabled by SNe Ia first revealed the accelerating expansion of the universe, now widely believed (though hardly understood) to require the presence of a mysterious "dark" energy. General consensus holds that Type Ia SNe result from thermonuclear explosions of a white dwarf (WD) in a binary system; however, little is known of the precise nature of the companion star and the physical properties of the progenitor system. Here we make use of extensive historical imaging obtained at the location of SN 2011fe/PTF11kly, the closest SN Ia discovered in the digital imaging era, to constrain the visible-light luminosity of the progenitor to be 10-100 times fainter than previous limits on other SN Ia progenitors. This directly rules out luminous red giants and the vast majority of helium stars as the ...

  17. PTF11eon/SN2011dh: Discovery of a Type IIb Supernova From a Compact Progenitor in the Nearby Galaxy M51

    CERN Document Server

    Arcavi, Iair; Yaron, Ofer; Sternberg, Assaf; Rabinak, Itay; Waxman, Eli; Kasliwal, Mansi M; Quimby, Robert M; Ofek, Eran O; Horesh, Assaf; Kulkarni, Shrinivas R; Filippenko, Alexei V; Silverman, Jeffrey M; Cenko, S Bradley; Li, Weidong; Bloom, Joshua S; Sullivan, Mark; Fox, Derek B; Nugent, Peter E; Poznanski, Dovi; Gorbikov, Evgeny; Riou, Amedee; Lamotte-Bailey, Stephane; Griga, Thomas; Cohen, Judith G; Polishook, David; Xu, Dong; Ben-Ami, Sagi; Manulis, Ilan; Walker, Emma S; Mazzali, Paulo A; Pian, Elena; Matheson, Thomas; Maquire, Kate; Pan, Yen-Chen; Bersier, David; James, Philip; Marchant, Jonathan M; Smith, Robert J; Mottram, Chris J; Barnsley, Robert M; Kandrashoff, Michael T; Clubb, Kelsey I

    2011-01-01

    On May 31, 2011 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras, as well as by the Palomar Transient Factory (PTF) survey, and rapidly confirmed it to be a Type II supernova. Our early light curve and spectroscopy indicates that PTF11eon resulted from the explosion of a relatively compact progenitor star as evidenced by the rapid shock-breakout cooling seen in the light curve, the relatively low temperature in early-time spectra and the prompt appearance of low-ionization spectral features. The spectra of PTF11eon are dominated by H lines out to day 10 after explosion, but initial signs of He appear to be present. Assuming that He lines continue to develop in the near future, this SN is likely a member of the cIIb (compact IIb; Chevalier and Soderberg 2010) class, with progenitor radius larger than that of SN 2008ax and smaller than the eIIb (extended IIb) SN 1993J progenitor. Our data imply that the object...

  18. Progenitors of supernova Ibc: a single Wolf-Rayet star as the possible progenitor of the SN Ib iPTF13bvn

    CERN Document Server

    Groh, Jose H; Ekstrom, Sylvia

    2013-01-01

    Core-collapse supernova (SN) explosions mark the end of the tumultuous life of massive stars. Determining the nature of their progenitors is a crucial step towards understanding the properties of SNe. Until recently, no progenitor has been directly detected for SN of type Ibc, which are believed to come from massive stars that lose their Hydrogen envelope through stellar winds and from binary systems where the companion has stripped the H envelope from the primary. Here we analyze recently-reported observations of iPTF13bvn, which could possibly be the first detection of a SN Ib progenitor based on pre-explosion images. Very interestingly, the recently published Geneva models of single stars can reproduce the observed photometry of the progenitor candidate and its mass-loss rate, confirming the scenario from Cao et al 2013. We find that a single WR star with initial mass in the range 31-35 Msun fits the observed photometry of the progenitor of iPTF13bvn. The progenitor likely has a luminosity of log (L/Lsun)~...

  19. VizieR Online Data Catalog: Metallicity from Type II SN from (i)PTF (Taddia+, 2016)

    Science.gov (United States)

    Taddia, F.; Moquist, P.; Sollerman, J.; Rubin, A.; Leloudas, G.; Gal-Yam, A.; Arcavi, I.; Cao, Y.; Filippenko, A. V.; Graham, M. L.; Mazzali, P. A.; Nugent, P. E.; Pan, Y.-C.; Silverman, J. M.; Xu, D.; Yaron, O.

    2016-06-01

    We collected the optical spectra of the 57 SNe II presented by R15, as obtained by the (i)PTF collaboration. The selected spectra were obtained with many different telescopes and instruments, as summarized in Table A.1. For each spectrum where FeIIλ5018 was identified, we established the phase, based on the explosion date reported by Rubin et al. (2016ApJ...820...33R). (2 data files).

  20. PTF12os and iPTF13bvn. Two stripped-envelope supernovae from low-mass progenitors in NGC 5806

    CERN Document Server

    Fremling, C; Taddia, F; Ergon, M; Fraser, M; Karamehmetoglu, E; Valenti, S; Jerkstrand, A; Arcavi, I; Bufano, F; Rosa, N Elias; Filippenko, A V; Fox, D; Gal-Yam, A; Howell, D A; Kotak, R; Mazzali, P; Milisavljevic, D; Nugent, P E; Nyholm, A; Pian, E; Smartt, S

    2016-01-01

    We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (i)PTF. These SNe, designated PTF12os/SN 2012P and iPTF13bvn, exploded at a similar distance from the host-galaxy center. We classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified as Type Ib having a likely progenitor with zero age main sequence (ZAMS) mass below ~17 solar masses. Our main objective is to constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put constraints on the SN progenitors. We present comprehensive datasets on the SNe, and introduce a new reference-subtraction pipeline (FPipe) currently in use by the iPTF. We perform a detailed study of the light curves (LCs) and spectral evolution of the SNe. The bolometric LCs are modeled using the hydrodynamical code HYDE. We use nebular models and late-time spectra to constrain the ZAMS mass of the progenitors. We perform image registration of ground-based images of PTF12os to archiv...

  1. Patient Treatment File (PTF)

    Data.gov (United States)

    Department of Veterans Affairs — This database is part of the National Medical Information System (NMIS). The Patient Treatment File (PTF) contains a record for each inpatient care episode provided...

  2. Spectroscopy of SN 2016hnk (= ATLAS16dpc) with SOAR and SALT: A Peculiar Type-Ia Supernova Similar to PTF09dav

    Science.gov (United States)

    Pan, Y.-C.; Duarte, A. S.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.; Kniazev, A.

    2016-11-01

    We obtained spectroscopic observations of SN 2016hnk (= ATLAS16dpc) with the Goodman spectrograph on the Southern Astrophysical Research (SOAR) telescope on UT 2016 Oct 30.3 and with the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT) on UT 2016 Oct 31.0.

  3. PTF12os and iPTF13bvn. Two stripped-envelope supernovae from low-mass progenitors in NGC 5806

    Science.gov (United States)

    Fremling, C.; Sollerman, J.; Taddia, F.; Ergon, M.; Fraser, M.; Karamehmetoglu, E.; Valenti, S.; Jerkstrand, A.; Arcavi, I.; Bufano, F.; Elias Rosa, N.; Filippenko, A. V.; Fox, D.; Gal-Yam, A.; Howell, D. A.; Kotak, R.; Mazzali, P.; Milisavljevic, D.; Nugent, P. E.; Nyholm, A.; Pian, E.; Smartt, S.

    2016-09-01

    Context. We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (intermediate) Palomar Transient Factory [(i)PTF]. These SNe, designated PTF12os/SN 2012P and iPTF13bvn, exploded within ~520 days of one another at a similar distance from the host-galaxy center. We classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified as Type Ib having a likely progenitor with zero age main sequence (ZAMS) mass below ~17 M⊙. Because of the shared and nearby host, we are presented with a unique opportunity to compare these two SNe. Aims: Our main objective is to constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put constraints on the SN progenitors. We also aim to spatially map the metallicity in the host galaxy, and to investigate the presence of hydrogen in early-time spectra of both SNe. Methods: We present comprehensive datasets collected on PTF12os and iPTF13bvn, and introduce a new automatic reference-subtraction photometry pipeline (FPipe) currently in use by the iPTF. We perform a detailed study of the light curves (LCs) and spectral evolution of the SNe. The bolometric LCs are modeled using the hydrodynamical code hyde. We analyze early spectra of both SNe to investigate the presence of hydrogen; for iPTF13bvn we also investigate the regions of the Paschen lines in infrared spectra. We perform spectral line analysis of helium and iron lines to map the ejecta structure of both SNe. We use nebular models and late-time spectroscopy to constrain the ZAMS mass of the progenitors. We also perform image registration of ground-based images of PTF12os to archival HST images of NGC 5806 to identify a potential progenitor candidate. Results: We find that our nebular spectroscopy of iPTF13bvn remains consistent with a low-mass progenitor, likely having a ZAMS mass of ~12M⊙. Our late-time spectroscopy of PTF12os is consistent with a ZAMS mass of ~15M⊙. We

  4. Optical photometry and spectroscopy of the low-luminosity, broad-lined Ic supernova iPTF15dld

    DEFF Research Database (Denmark)

    Pian, E.; Tomasella, L.; Cappellaro, E.

    2017-01-01

    Core-collapse stripped-envelope supernova (SN) explosions reflect the diversity of physical parameters and evolutionary paths of their massive star progenitors. We have observed the Type Ic SN iPTF15dld (z = 0.047), reported by the Palomar Transient Factory. Spectra were taken starting 20 rest...

  5. The discovery of the multiply-imaged lensed Type Ia supernova iPTF16geu

    CERN Document Server

    Goobar, A; Kulkarni, S R; Nugent, P E; Johansson, J; Steidel, C; Law, D; Mortsell, E; Quimby, R; Blagorodnova, N; Brandeker, A; Cao, Y; Cooray, A; Ferretti, R; Fremling, C; Hangard, L; Kasliwal, M; Kupfer, T; Lunnan, R; Masci, F; Miller, A A; Nayyeri, H; Neill, J D; Ofek, E O; Papadogiannakis, S; Petrushevska, T; Ravi, V; Sollerman, J; Sullivan, M; Taddia, F; Walters, R; Wilson, D; Yan, L; Yaron, O

    2016-01-01

    We report the discovery of a gravitationally lensed Type Ia supernova (SN Ia) by the intermediate Palomar Transient Factor (iPTF). The light originating from SNIa iPTF16geu, at redshift $z_{SN}=0.409$, is magnified by an intervening galaxy at $z_{l}=0.216$, acting as a gravitational lens. Using Laser Guide Star Adaptive Optics (LGSAO) OSIRIS and NIRC2 observations at the Keck telescope, as well as measurements with the Hubble Space Telescope, we were able to detect the strong bending of the light path, both for iPTF16geu and its host galaxy. We detect four images of the supernova, approximately 0.3" from the center of the lensing galaxy. iPTF16geu is the first \\snia for which multiple images have been observed. From the fits of the multi-color lightcurve we derive a lensing magnification, $\\Delta m = 4.37 \\pm 0.15$ mag, corresponding to a total amplification of the supernova flux by a factor $\\mu \\sim 56$. The discovery of iPTF16geu suggests that lensing by sub-kpc structures may have been greatly underestima...

  6. Long-rising Type II supernovae from PTF and CCCP

    CERN Document Server

    Taddia, F; Fremling, C; Migotto, K; Gal-Yam, A; Armen, S; Duggan, G; Ergon, M; Filippenko, A V; Fransson, C; Hosseinzadeh, G; Kasliwal, M M; Laher, R R; Leloudas, G; Leonard, D C; Lunnan, R; Masci, F J; Moon, D -S; Silverman, J M; Wozniak, P R

    2016-01-01

    Supernova (SN) 1987A was a peculiar H-rich event with a long-rising (LR) light curve (LC), stemming from a compact blue supergiant star (BSG). Only a few similar events have been presented in the literature. We present new data for a sample of 6 LR Type II SNe (SNe II), 3 of which were discovered and observed by the Palomar Transient Factory (PTF) and 3 observed by the Caltech Core-Collapse Project (CCCP). Our aim is to enlarge the family of LR SNe II, characterizing their properties. Spectra, LCs, and host-galaxies (HG) of these SNe are presented. Comparisons with known SN 1987A-like events are shown, with emphasis on the absolute magnitudes, colors, expansion velocities, and HG metallicities. Bolometric properties are derived from the multiband LC. By modeling the early-time LCs with scaling relations derived from the SuperNova Explosion Code (SNEC) models of MESA progenitor stars, we estimate the progenitor radii of these SNe and other progenitor parameters. We present PTF12kso, a LR SN II with the largest...

  7. Metallicity from Type II Supernovae from the (i)PTF

    CERN Document Server

    Taddia, F; Sollerman, J; Rubin, A; Leloudas, G; Gal-Yam, A; Arcavi, I; Cao, Y; Filippenko, A V; Graham, M L; Mazzali, P A; Nugent, P E; Pan, Y -C; Silverman, J M; Xu, D; Yaron, O

    2016-01-01

    Type IIP supernovae (SNe IIP) have recently been proposed as metallicity ($Z$) probes. The spectral models of Dessart et al. (2014) showed that the pseudo-equivalent width of Fe II $\\lambda$5018 (pEW$_{5018}$) during the plateau phase depends on the primordial $Z$, but there was a paucity of SNe IIP exhibiting pEW$_{5018}$ compatible with $Z < 0.4 {\\rm Z}_{\\odot}$. This lack might be due to some physical property of the SN II population, or to the fact that those SNe were discovered in luminous, metal-rich targeted galaxies. Here we use SN II observations from the untargeted (intermediate) Palomar Transient Factory [(i)PTF] survey, aiming to investigate the pEW$_{5018}$ distribution of this SN population and in particular to look for the presence of SNe II at lower $Z$. We perform pEW$_{5018}$ measurements on the spectra of a sample of 39 (i)PTF SNe II, selected to have well-constrained explosion epochs and light-curve properties (Rubin et al. 2015). Based on the comparison with the pEW$_{5018}$ spectral m...

  8. PTF10ops - a subluminous, normal-width lightcurve Type Ia supernova in the middle of nowhere

    CERN Document Server

    Maguire, Kate; Thomas, Rollin C; Nugent, Peter E; Howell, D Andrew; Gal-Yam, Avishay; Arcavi, Iair; Ben-Ami, Sagi; Blake, Sarah; Botyanszki, Janos; Buton, Clement; Cooke, Jeffery; Ellis, Richard S; Hook, Isobel M; Kasliwal, Mansi M; Pan, Yen-Chen; Pereira, Rui; Podsiadlowski, Philipp; Sternberg, Assaf; Suzuki, Nao; Xu, Dong; Yaron, Ofer; Bloom, Joshua S; Cenko, S Bradley; Kulkarni, Shrinivas R; Law, Nicholas; Ofek, Eran O; Poznanski, Dovi; Quimby, Robert M

    2011-01-01

    PTF10ops is a Type Ia supernova (SN Ia), whose lightcurve and spectral properties place it outside the current SN Ia subtype classifications. Its spectra display the characteristic lines of subluminous SNe Ia, but it has a normal-width lightcurve with a long rise-time, typical of normal luminosity SNe Ia. The early-time optical spectra of PTF10ops were modelled using a spectral fitting code and found to have all the lines typically seen in subluminous SNe Ia, without the need to invoke more uncommon elements. The host galaxy environment of PTF10ops is also unusual with no galaxy detected at the position of the SN down to an absolute limiting magnitude of r \\geq -12.0 mag, but a very massive galaxy is present at a separation of ~148 kpc and at the same redshift as suggested by the SN spectral features. The progenitor of PTF10ops is most likely a very old star, possibly in a low metallicity environment, which affects its explosion mechanism and observational characteristics. PTF10ops does not easily fit into an...

  9. PTF discovery of PTF10abyy, a young Type II Supernova

    Science.gov (United States)

    Gal-Yam, A.; Yaron, O.; Ben-Ami, S.; Sternberg, A.; Green, Y.; Xu, D.; Arcavi, I.; Kasliwal, M. M.; Quimby, R. M.; Ofek, E. O.; Kulkarni, S. R.; Nugent, H. Ebeling P.; Howell, D. A.; Sullivan, M.; Bloom, J. S.; Law, N. M.

    2010-12-01

    The PTF (ATEL #1964; http://www.astro.caltech.edu/ptf/) reports the discovery of a new supernova, PTF10abyy. The supernova was discovered by Oarical, an autonomous software framework of the PTF collaboration, on December 8 UT at RA(J2000) = 05:16:40.52 and DEC(J2000) = +06:47:53.8 at a magnitude of 18.7 in R-band (calibrated with respect to the USNOB1 catalog). The supernova was not detected down to mag 21 in previous PTF images taken during Dec.

  10. PTF10fqs: A Luminous Red Nova in the Spiral Galaxy Messier 99

    CERN Document Server

    Kasliwal, Mansi M; Quimby, Robert M; Ofek, Eran O; Nugent, Peter; Jacobsen, Janet; Gal-Yam, Avishay; Green, Yoav; Arcavi, Iair; Yaron, Ofer; Howell, Jacob L; Fox, Derek B; Cenko, S Bradley; Kleiser, Io; Bloom, Joshua S; Miller, Adam; Poznanski, Dovi; Li, Weidong; Filippenko, Alexei V; Starr, Dan; Law, Nicholas M; Helou, George; Frail, Dale A; Neill, James D; Forster, Karl; Martin, D Christopher; Tendulkar, Shriharsh P; Gehrels, Neil; Kennea, Jamie; Sullivan, Mark; Dekany, Richard; Rahmer, Gustavo; Hale, David; Smith, Roger; Zolkower, Jeff; Velur, Viswa; Walters, Richard; Henning, John; Bui, Kahnh; McKenna, Dan; Blake, Cullen

    2010-01-01

    The Palomar Transient Factory (PTF) is systematically charting the optical transient and variable sky. A primary science driver of PTF is building a complete inventory of transients in the local Universe (distance less than 200 Mpc). Here, we report the discovery of PTF10fqs, a transient in the luminosity "gap" between novae and supernovae. Located in the spiral arm of Messier 99, PTF10fqs is red, slowly evolving and has a spectrum dominated by intermediate width Halpha and Calcium lines. The explosion signature is similar to M85OT2006-1, SN2008S and NGC300-OT. The origin of these events is shrouded in mystery, controversy (and in some cases, in dust). PTF10fqs shows some evidence of a broad feature (around 8600A) that may suggest very large velocities in this explosion (~10000 km/s). Ongoing surveys can be expected to find a few such events per year. Sensitive spectroscopy and statistics (disk versus bulge) will eventually make it possible for astronomers to unravel the nature of these mysterious explosions.

  11. Supernova PTF 09UJ: A Possible Shock Breakout from a Dense Circumstellar Wind

    Science.gov (United States)

    Ofek, E. O.; Rabinak, I.; Neill, J. D.; Arcavi, I.; Cenko, S. B.; Waxman, E.; Kulkarni, S. R.; Gal-Yam, A.; Nugent, P. E.; Bildsten, L.; Bloom, J. S.; Filippenko, A. V.; Forster, K.; Howell, D. A.; Jacobsen, J.; Kasliwal, M. M.; Law, N.; Martin, C.; Poznanski, D.; Quimby, R. M.; Shen, K. J.; Sullivan, M.; Dekany, R.; Rahmer, G.; Hale, D.; Smith, R.; Zolkower, J.; Velur, V.; Walters, R.; Henning, J.; Bui, K.; McKenna, D.

    2010-12-01

    Type-IIn supernovae (SNe IIn), which are characterized by strong interaction of their ejecta with the surrounding circumstellar matter (CSM), provide a unique opportunity to study the mass-loss history of massive stars shortly before their explosive death. We present the discovery and follow-up observations of an SN IIn, PTF 09uj, detected by the Palomar Transient Factory (PTF). Serendipitous observations by Galaxy Evolution Explorer (GALEX) at ultraviolet (UV) wavelengths detected the rise of the SN light curve prior to the PTF discovery. The UV light curve of the SN rose fast, with a timescale of a few days, to a UV absolute AB magnitude of about -19.5. Modeling our observations, we suggest that the fast rise of the UV light curve is due to the breakout of the SN shock through the dense CSM (n ≈ 1010 cm-3). Furthermore, we find that prior to the explosion the progenitor went through a phase of high mass-loss rate (~0.1 M sun yr-1) that lasted for a few years. The decay rate of this SN was fast relative to that of other SNe IIn.

  12. Supernova PTF 09uj: A possible shock breakout from a dense circumstellar wind

    CERN Document Server

    Ofek, E O; Neill, J D; Arcavi, I; Cenko, S B; Waxman, E; Kulkarni, S R; Yam, A Gal; Nugent, P E; Bildsten, L; Bloom, J S; Filippenko, A V; Forster, K; Howell, D A; Jacobsen, J; Kasliwal, M M; Law, N; Martin, C; Poznanski, D; Quimby, R M; Shen, K J; Sullivan, M; Dekany, R; Rahmer, G; Hale, D; Smith, R; Zolkower, J; Velur, V; Walters, R; Henning, J; Bui, K; McKenna, D

    2010-01-01

    Type-IIn supernovae (SNe), which are characterized by strong interaction of their ejecta with the surrounding circumstellar matter (CSM), provide a unique opportunity to study the mass-loss history of massive stars shortly before their explosive death. We present the discovery and follow-up observations of a Type IIn SN, PTF 09uj, detected by the Palomar Transient Factory (PTF). Serendipitous observations by GALEX at ultraviolet (UV) wavelengths detected the rise of the SN light curve prior to the PTF discovery. The UV light curve of the SN rose fast, with a time scale of a few days, to a UV absolute AB magnitude of about -19.5. Modeling our observations, we suggest that the fast rise of the UV light curve is due to the breakout of the SN shock through the dense CSM (n~10^10 cm^-3). Furthermore, we find that prior to the explosion the progenitor went through a phase of high mass-loss rate (~0.1 solar mass per year) that lasted for a few years. The decay rate of this SN was fast relative to that of other SNe I...

  13. Adaptive Optics and planned HST follow-up observations of the strongly lensed SNIa iPTF16geu

    Science.gov (United States)

    Goobar, Ariel; Amanullah, Rahman; Kulkarni, Shri; Steidel, Charles; Law, David

    2016-10-01

    Adaptive optics (AO) observations of iPTF16geu (ATel #9603) were carried out on October 11 with NACO in Natural Guide Star (NGS) mode on VLT. A bright star 30" SE of the SN position provided for the AO corrections.

  14. iPTF13beo: The Double-Peaked Light Curve of a Type Ibn Supernova Discovered Shortly after Explosion

    CERN Document Server

    Gorbikov, Evgeny; Ofek, Eran O; Vreeswijk, Paul M; Nugent, Peter E; Chotard, Nicolas; Kulkarni, Shrinivas R; Cao, Yi; De Cia, Annalisa; Yaron, Ofer; Tal, David; Arcavi, Iair; Kasliwal, Mansi M; Cenko, S Bradley; Sullivan, Mark

    2013-01-01

    We present optical photometric and spectroscopic observations of the Type Ibn (SN 2006jc-like) supernova iPTF13beo. Detected by the intermediate Palomar Transient Factory on 2013 May 19.39, ~3 hours after the estimated explosion time, iPTF13beo is the youngest and the most distant (430 Mpc) Type Ibn event ever observed. Type Ibn events are rare, and their early evolution, both photometric and spectroscopic, has not been studied yet. The iPTF13beo light curve is consistent with light curves of other Type Ibn SNe and with light curves of fast Type Ic events, but with a slightly faster rise-time of two days. In addition, the iPTF13beo light curve exhibits a double-peak structure separated by 9 days, not observed before in any Type Ibn SN. Low-resolution spectra were obtained during the two peaks of the iPTF13beo light curve. The spectrum taken during the rising stage (2.4 days after the estimated explosion time) is featureless and similar to early spectra of SNe Ic-BL. The spectrum obtained during the declining ...

  15. Analysis list: Ptf1a [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Ptf1a Embryo,Pancreas + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Ptf1...a.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Ptf1a.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/mm9/target/Ptf1a.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Ptf1a.Embryo.tsv,htt...p://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Ptf1a.Pancreas.tsv http://dbarch

  16. A multi-wavelength investigation of the radio-loud supernova PTF11qcj and its circumstellar environment

    Energy Technology Data Exchange (ETDEWEB)

    Corsi, A. [Department of Physics, The George Washington University, 725 21st St, NW, Washington, DC 20052 (United States); Ofek, E. O.; Gal-Yam, A.; Xu, D. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Frail, D. A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Kulkarni, S. R.; Horesh, A.; Carpenter, J.; Arcavi, I.; Cao, Y.; Mooley, K.; Sesar, B. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Fox, D. B. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Kasliwal, M. M. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sullivan, M.; Maguire, K.; Pan, Y.-C. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Cenko, S. B. [NASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771 (United States); Sternberg, A. [Max-Planck-Institut fur Astrophysik, D-85741 Garching (Germany); Bersier, D., E-mail: corsi@gwu.edu [Astrophysics Research Institute, Liverpool John Moores University, Liverpool (United Kingdom); and others

    2014-02-10

    We present the discovery, classification, and extensive panchromatic (from radio to X-ray) follow-up observations of PTF11qcj, a supernova (SN) discovered by the Palomar Transient Factory (PTF). Our observations with the Karl G. Jansky Very Large Array show that this event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to that of the famous gamma-ray-burst-associated SN 1998bw (L {sub 5} {sub GHz} ≈ 10{sup 29} erg s{sup –1} Hz{sup –1}). PTF11qcj is also detected in X-rays with the Chandra Observatory, and in the infrared band with Spitzer. Our multi-wavelength analysis probes the SN interaction with circumstellar material. The radio observations suggest a progenitor mass-loss rate of ∼10{sup –4} M {sub ☉} yr{sup –1} × (v{sub w} /1000 km s{sup –1}), and a velocity of ≈0.3-0.5 c for the fastest moving ejecta (at ≈10 days after explosion). However, these estimates are derived assuming the simplest model of SN ejecta interacting with a smooth circumstellar wind, and do not account for possible inhomogeneities in the medium and asphericity of the explosion. The radio data show deviations from such a simple model, as well as a late-time re-brightening. The X-ray flux from PTF11qcj is compatible with the high-frequency extrapolation of the radio synchrotron emission (within the large uncertainties). A light echo from pre-existing dust is in agreement with our infrared data. Our pre-explosion data from the PTF suggest that a precursor eruption of absolute magnitude M{sub r} ≈ –13 mag may have occurred ≈2.5 yr prior to the SN explosion. Overall, PTF11qcj fits the expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may be a feature characterizing the final pre-explosion evolution of such stars.

  17. iPTF15dtg: a double-peaked Type Ic supernova from a massive progenitor

    Science.gov (United States)

    Taddia, F.; Fremling, C.; Sollerman, J.; Corsi, A.; Gal-Yam, A.; Karamehmetoglu, E.; Lunnan, R.; Bue, B.; Ergon, M.; Kasliwal, M.; Vreeswijk, P. M.; Wozniak, P. R.

    2016-08-01

    Context. Type Ic supernovae (SNe Ic) arise from the core-collapse of H- (and He-) poor stars, which could either be single Wolf-Rayet (WR) stars or lower-mass stars stripped of their envelope by a companion. Their light curves are radioactively powered and usually show a fast rise to peak (~10-15 d), without any early (in the first few days) emission bumps (with the exception of broad-lined SNe Ic) as sometimes seen for other types of stripped-envelope SNe (e.g., Type IIb SN 1993J and Type Ib SN 2008D). Aims: We have studied iPTF15dtg, a spectroscopically normal SN Ic with an early excess in the optical light curves followed by a long (~30 d) rise to the main peak. It is the first spectroscopically-normal double-peaked SN Ic to be observed. Our aim is to determine the properties of this explosion and of its progenitor star. Methods: Optical photometry and spectroscopy of iPTF15dtg was obtained with multiple telescopes. The resulting light curves and spectral sequence are analyzed and modeled with hydrodynamical and analytical models, with particular focus on the early emission. Results: iPTF15dtg is a slow rising SN Ic, similar to SN 2011bm. Hydrodynamical modeling of the bolometric properties reveals a large ejecta mass (~10 M⊙) and strong 56Ni mixing. The luminous early emission can be reproduced if we account for the presence of an extended (≳500 R⊙), low-mass (≳0.045 M⊙) envelope around the progenitor star. Alternative scenarios for the early peak, such as the interaction with a companion, a shock-breakout (SBO) cooling tail from the progenitor surface, or a magnetar-driven SBO are not favored. Conclusions: The large ejecta mass and the presence of H- and He-free extended material around the star suggest that the progenitor of iPTF15dtg was a massive (≳35 M⊙) WR star that experienced strong mass loss.

  18. iPTF15dtg: a double-peaked Type Ic Supernova from a massive progenitor

    CERN Document Server

    Taddia, F; Sollerman, J; Corsi, A; Gal-Yam, A; Karamehmetoglu, E; Lunnan, R; Bue, B; Ergon, M; Kasliwal, M; Vreeswijk, P M; Wozniak, P R

    2016-01-01

    Type Ic supernovae (SNe Ic) arise from the core-collapse of H (and He) poor stars, which could be either single WR stars or lower-mass stars stripped of their envelope by a companion. Their light curves are radioactively powered and usually show a fast rise to peak ($\\sim$10-15 d), without any early (first few days) emission bumps (with the exception of broad-lined SNe Ic) as sometimes seen for other types of stripped-envelope SNe (e.g., Type IIb SN 1993J and Type Ib SN 2008D). We have studied iPTF15dtg, a spectroscopically normal SN Ic with an early excess in the optical light curves followed by a long ($\\sim$30 d) rise to the main peak. It is the first spectroscopically-normal double-peaked SN Ic observed. We aim to determine the properties of this explosion and of its progenitor star. Optical photometry and spectroscopy of iPTF15dtg was obtained with multiple telescopes. The resulting light curves and spectral sequence are analyzed and modelled with hydrodynamical and analytical models, with particular foc...

  19. Explaining the Type Ia Supernova PTF 11kx with the Core Degenerate Scenario

    CERN Document Server

    Soker, Noam; Garcia-Berro, Enrique; Torres, Santiago; Camacho, Judit

    2012-01-01

    We argue that the multiple shells of circumstellar material (CSM) and the supernovae (SN) ejecta interaction with the CSM starting 59 days after the explosion of the Type Ia SN (SN Ia) PTF 11kx, are best described by the core-degenerate (CD) scenario for SN Ia. In the CD scenario the super-Chandrasekhar mass white dwarf (WD) is formed at the termination of the common envelope phase from a merger of a WD companion with the hot core of a massive asymptotic giant branch (AGB) star. In most cases the WD is destructed and accreted onto the more massive core. However, in rare cases where mergers take place when the WD is denser than the core, the core will be destructed and accreted onto the cooler WD. In such cases the explosion might occur with no appreciable delay, i.e., months to years after the termination of the common envelope (CE) phase. This, we propose, is the evolutionary route that lead to the explosion of PTF 11kx. The CD scenario can account for the very massive CSM within ~1000 AU of the exploding PT...

  20. The bumpy light curve of Type IIn supernova iPTF13z over 3 years

    Science.gov (United States)

    Nyholm, A.; Sollerman, J.; Taddia, F.; Fremling, C.; Moriya, T. J.; Ofek, E. O.; Gal-Yam, A.; De Cia, A.; Roy, R.; Kasliwal, M. M.; Cao, Y.; Nugent, P. E.; Masci, F. J.

    2017-08-01

    A core-collapse (CC) supernova (SN) of Type IIn is dominated by the interaction of SN ejecta with the circumstellar medium (CSM). Some SNe IIn (e.g. SN 2006jd) have episodes of re-brightening ("bumps") in their light curves. We present iPTF13z, a Type IIn SN discovered on 2013 February 1 by the intermediate Palomar Transient Factory (iPTF). This SN showed at least five bumps in its declining light curve between 130 and 750 days after discovery. We analyse this peculiar behaviour and try to infer the properties of the CSM, of the SN explosion, and the nature of the progenitor star. We obtained multi-band optical photometry for over 1000 days after discovery with the P48 and P60 telescopes at Palomar Observatory. We obtained low-resolution optical spectra during the same period. We did an archival search for progenitor outbursts. We analyse the photometry and the spectra, and compare iPTF13z to other SNe IIn. In particular we derive absolute magnitudes, colours, a pseudo-bolometric light curve, and the velocities of the different components of the spectral lines. A simple analytical model is used to estimate the properties of the CSM. iPTF13z had a light curve peaking at Mr ≲ - 18.3 mag. The five bumps during its decline phase had amplitudes ranging from 0.4 to 0.9 mag and durations between 20 and 120 days. The most prominent bumps appeared in all the different optical bands, when covered. The spectra of this SN showed typical SN IIn characteristics, with emission lines of Hα (with broad component FWHM 103 - 104 km s-1 and narrow component FWHM 102 km s-1) and He i, but also with Fe ii, Ca ii, Na i D and Hβ P Cygni profiles (with velocities of 103km s-1). A pre-explosion outburst was identified lasting ≳ 50 days, with Mr ≈ - 15 mag around 210 days before discovery. Large, variable progenitor mass-loss rates (≳0.01M⊙ yr-1) and CSM densities (≳10-16 g cm-3) are derived. The SN was hosted by a metal-poor dwarf galaxy at redshift z = 0.0328. We suggest that

  1. SN2002es-like Supernovae From Different Viewing Angles

    CERN Document Server

    Cao, Yi; Gal-Yam, Avishay; Papadogiannakis, S; Nugent, P E; Masci, Frank J; Bue, Brian D

    2016-01-01

    In this letter, we compare optical light curves of two SN2002es-like Type Ia supernovae, iPTF14atg and iPTF14dpk, from the intermediate Palomar Transient Factory. Although the two light curves resemble each other around and after maximum, they show distinct early-phase rise behavior in the $\\textit{r}$-band. On the one hand, iPTF14atg revealed a slow and steady rise which lasted for 22 days with a mean rise rate of $0.2\\sim0.3\\,\\textrm{mag}\\,\\textrm{day}^{-1}$, before it reached the $R$-band peak ($-18.05\\,$mag). On the other hand, iPTF14dpk rose rapidly to $-17\\,$mag within a day of discovery with a rise rate $>1.8\\,\\textrm{mag}\\,\\textrm{day}^{-1}$, and then rose slowly to its peak ($-18.19\\,$mag) with a rise rate similar to iPTF14atg. The apparent total rise time of iPTF14dpk is therefore only 16 days. We show that emission from iPTF14atg before $-17\\,$days with respect to its maximum can be entirely attributed to radiation produced by collision between the SN and its companion star. Such emission is absent...

  2. PTF 11kx: a type Ia supernova with a symbiotic nova progenitor.

    Science.gov (United States)

    Dilday, B; Howell, D A; Cenko, S B; Silverman, J M; Nugent, P E; Sullivan, M; Ben-Ami, S; Bildsten, L; Bolte, M; Endl, M; Filippenko, A V; Gnat, O; Horesh, A; Hsiao, E; Kasliwal, M M; Kirkman, D; Maguire, K; Marcy, G W; Moore, K; Pan, Y; Parrent, J T; Podsiadlowski, P; Quimby, R M; Sternberg, A; Suzuki, N; Tytler, D R; Xu, D; Bloom, J S; Gal-Yam, A; Hook, I M; Kulkarni, S R; Law, N M; Ofek, E O; Polishook, D; Poznanski, D

    2012-08-24

    There is a consensus that type Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumstellar material are detected, and the SN ejecta are seen to interact with circumstellar material starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi.

  3. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    CERN Document Server

    Hsiao, E Y; Contreras, C; Höflich, P; Sand, D; Marion, G H; Phillips, M M; Stritzinger, M; González-Gaitán, S; Mason, R E; Folatelli, G; Parent, E; Gall, C; Amanullah, R; Anupama, G C; Arcavi, I; Banerjee, D P K; Beletsky, Y; Blanc, G A; Bloom, J S; Brown, P J; Campillay, A; Cao, Y; De Cia, A; Diamond, T; Freedman, W L; Gonzalez, C; Goobar, A; Holmbo, S; Howell, D A; Johansson, J; Kasliwal, M M; Kirshner, R P; Krisciunas, K; Kulkarni, S R; Maguire, K; Milne, P A; Morrell, N; Nugent, P E; Ofek, E O; Osip, D; Palunas, P; Perley, D A; Persson, S E; Piro, A L; Rabus, M; Roth, M; Schiefelbein, J M; Srivastav, S; Sullivan, M; Suntzeff, N B; Surace, J; Woźnia, P R; Yaron, O

    2015-01-01

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C I {\\lambda}1.0693 {\\mu}m line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though the optical spectroscopic time series began early and is densely-cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with {\\Delta}m15(B) = 1.79 $\\pm$ 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categ...

  4. EVLA Observations of an Extremely Young Type Ia Supernova PTF10ygu

    Science.gov (United States)

    Kasliwal, Mansi; Frail, Dale; Nugent, Peter; Howell, Andy; Sullivan, Mark; Gal-Yam, Avishay; Arcavi, Iair; Quimby, Robert; Ofek, Eran; Kulkarni, Shri; Yuan, Fang; Akerlof, Carl; McKay, Tim

    2010-10-01

    We triggered our NRAO Target Of Opportunity program "Exploring Transients in the Local Universe" and used the Expanded Very Large Array (EVLA) to observe PTF10ygu (ATEL#2934), an extremely young Type Ia supernova discovered by the Palomar Transient Factory. The EVLA observations were made on 2010 October 16.68 UT, when this Type Ia supernova was two weeks before maximum light (based on contemporaneous spectroscopy), one of the youngest supernovae to be observed in the radio.

  5. Interpreting the Strongly Lensed Supernova iPTF16geu: Time Delay Predictions, Microlensing, and Lensing Rates

    Science.gov (United States)

    More, Anupreeta; Suyu, Sherry H.; Oguri, Masamune; More, Surhud; Lee, Chien-Hsiu

    2017-02-01

    We present predictions for time delays between multiple images of the gravitationally lensed supernova, iPTF16geu, which was recently discovered from the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type Ia where the intrinsic luminosity is usually well known, accurately measured time delays of the multiple images could provide tight constraints on the Hubble constant. According to our lens mass models constrained by the Hubble Space Telescope F814W image, we expect the maximum relative time delay to be less than a day, which is consistent with the maximum of 100 hr reported by Goobar et al. but places a stringent upper limit. Furthermore, the fluxes of most of the supernova images depart from expected values suggesting that they are affected by microlensing. The microlensing timescales are small enough that they may pose significant problems to measure the time delays reliably. Our lensing rate calculation indicates that the occurrence of a lensed SN in iPTF is likely. However, the observed total magnification of iPTF16geu is larger than expected, given its redshift. This may be a further indication of ongoing microlensing in this system.

  6. Disappearance of the Progenitor of Supernova iPTF13bvn

    CERN Document Server

    Folatelli, Gastón; Kuncarayakti, Hanindyo; Maeda, Keiichi; Bersten, Melina C; Nomoto, Ken'ichi; Pignata, Giuliano; Hamuy, Mario; Quimby, Robert M; Zheng, Weikang; Filippenko, Alexei V; Clubb, Kelsey I; Smith, Nathan; Elias-Rosa, Nancy; Foley, Ryan J; Miller, Adam A

    2016-01-01

    Supernova (SN) iPTF13bvn in NGC 5806 was the first Type Ib SN to have been tentatively associated with a progenitor candidate in pre-explosion images. We performed deep ultraviolet (UV) and optical Hubble Space Telescope (HST) observations of the SN site ~740 days after explosion. We detect an object in the optical bands that is fainter than the pre-explosion object. This dimming is likely not produced by dust absorption in the ejecta; thus, our finding confirms the connection of the progenitor candidate with the SN. The object in our data is likely dominated by the fading SN, which implies that the pre-SN flux is mostly due to the progenitor. We compare our revised pre-SN photometry with previously proposed progenitor models. Although binary progenitors are favored, models need to be refined. In particular, to comply with our deep UV detection limit, any companion star must be less luminous than a late-O star or substantially obscured by newly formed dust. A definitive progenitor characterization will requir...

  7. Follow-up photometry of iPTF16geu

    Science.gov (United States)

    Lee, C.-H.

    2016-10-01

    We report follow-up photometry of the strongly lensed SNIa iPTF16geu (ATel #9603, #9626). We observed iPTF16geu on 2016/10/17 with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma, under ~0.9" seeing condition.

  8. THE DETECTION RATE OF EARLY UV EMISSION FROM SUPERNOVAE: A DEDICATED GALEX/PTF SURVEY AND CALIBRATED THEORETICAL ESTIMATES

    Energy Technology Data Exchange (ETDEWEB)

    Ganot, Noam; Gal-Yam, Avishay; Ofek, Eran O.; Sagiv, Ilan; Waxman, Eli; Lapid, Ofer [Department of Particle Physics and Astrophysics, Faculty of Physics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Kulkarni, Shrinivas R.; Kasliwal, Mansi M. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Ben-Ami, Sagi [Smithsonian Astrophysical Observatory, Harvard-Smithsonian Ctr. for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chelouche, Doron; Rafter, Stephen [Physics Department, Faculty of Natural Sciences, University of Haifa, 31905 Haifa (Israel); Behar, Ehud; Laor, Ari [Physics Department, Technion Israel Institute of Technology, 32000 Haifa (Israel); Poznanski, Dovi; Nakar, Ehud; Maoz, Dan [School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Trakhtenbrot, Benny [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27 Zurich 8093 (Switzerland); Neill, James D.; Barlow, Thomas A.; Martin, Christofer D., E-mail: noam.ganot@gmail.com [California Institute of Technology, 1200 East California Boulevard, MC 278-17, Pasadena, CA 91125 (United States); Collaboration: ULTRASAT Science Team; WTTH consortium; GALEX Science Team; Palomar Transient Factory; and others

    2016-03-20

    The radius and surface composition of an exploding massive star, as well as the explosion energy per unit mass, can be measured using early UV observations of core-collapse supernovae (SNe). We present the first results from a simultaneous GALEX/PTF search for early ultraviolet (UV) emission from SNe. Six SNe II and one Type II superluminous SN (SLSN-II) are clearly detected in the GALEX near-UV (NUV) data. We compare our detection rate with theoretical estimates based on early, shock-cooling UV light curves calculated from models that fit existing Swift and GALEX observations well, combined with volumetric SN rates. We find that our observations are in good agreement with calculated rates assuming that red supergiants (RSGs) explode with fiducial radii of 500 R{sub ⊙}, explosion energies of 10{sup 51} erg, and ejecta masses of 10 M{sub ⊙}. Exploding blue supergiants and Wolf–Rayet stars are poorly constrained. We describe how such observations can be used to derive the progenitor radius, surface composition, and explosion energy per unit mass of such SN events, and we demonstrate why UV observations are critical for such measurements. We use the fiducial RSG parameters to estimate the detection rate of SNe during the shock-cooling phase (<1 day after explosion) for several ground-based surveys (PTF, ZTF, and LSST). We show that the proposed wide-field UV explorer ULTRASAT mission is expected to find >85 SNe per year (∼0.5 SN per deg{sup 2}), independent of host galaxy extinction, down to an NUV detection limit of 21.5 mag AB. Our pilot GALEX/PTF project thus convincingly demonstrates that a dedicated, systematic SN survey at the NUV band is a compelling method to study how massive stars end their life.

  9. The Progenitor of Supernova 2011dh/PTF11eon in Messier 51

    CERN Document Server

    Van Dyk, Schuyler D; Cenko, S Bradley; Kasliwal, Mansi M; Horesh, Assaf; Ofek, Eran O; Kraus, Adam L; Silverman, Jeffrey M; Arcavi, Iair; Filippenko, Alexei V; Gal-Yam, Avishay; Quimby, Robert M; Kulkarni, Shrinivas R; Yaron, Ofer; Polishook, David

    2011-01-01

    We have identified the progenitor, or progenitor system, responsible for supernova (SN) 2011dh/PTF11eon, in the nearby, nearly face-on galaxy M51. The available early-time spectra and photometry indicate that it is a stripped-envelope core-collapse SN, of Type IIb or transitional Type II/Ib, possibly similar to the famous SN 1993J in M81. The star was identified in pre-SN archival, multi-band images obtained by the Hubble Space Telescope with the Advanced Camera for Surveys. This identification has been confirmed, to the highest available astrometric precision, using a Keck-II adaptive-optics image. We infer that the extinction to SN 2011dh and its progenitor arises from a low Galactic foreground contribution, and that the SN environment is of solar metallicity. We find that if single, the star is a luminous (absolute V \\approx -7.7 mag) supergiant of effective temperature ~6100 K, bluer than the red supergiants which explode as the more common Type II-Plateau SNe. This requires that the star's hydrogen-rich ...

  10. The Rise and Fall of the Type Ib Supernova iPTF13bvn Not a Massive Wolf-Rayet Star

    Science.gov (United States)

    Fremling, C.; Sollerman, J.; Taddia, F.; Ergon, M.; Valenti, S.; Arcavi, I.; Ben-Ami, S.; Cao, Y.; Cenko, S. B.; Filippenko, A. V.; Gal-Yam, A.; Howell, D. A.

    2014-01-01

    Context. We investigate iPTF13bvn, a core-collapse (CC) supernova (SN) in the nearby spiral galaxy NGC 5806. This object was discovered by the intermediate Palomar Transient Factory (iPTF) very close to the estimated explosion date and was classified as a stripped-envelope CC SN, likely of Type Ib. Furthermore, a possible progenitor detection in pre-explosion Hubble Space Telescope (HST) images was reported, making this the only SN Ib with such an identification. Based on the luminosity and color of the progenitor candidate, as well as on early-time spectra and photometry of the SN, it was argued that the progenitor candidate is consistent with a single, massive Wolf-Rayet (WR) star. Aims. We aim to confirm the progenitor detection, to robustly classify the SN using additional spectroscopy, and to investigate if our follow-up photometric and spectroscopic data on iPTF13bvn are consistent with a single-star WR progenitor scenario. Methods. We present a large set of observational data, consisting of multi-band light curves (UBVRI, g'r'i'z') and optical spectra. We perform standard spectral line analysis to track the evolution of the SN ejecta. We also construct a bolometric light curve and perform hydrodynamical calculations to model this light curve to constrain the synthesized radioactive nickel mass and the total ejecta mass of the SN. Late-time photometry is analyzed to constrain the amount of oxygen. Furthermore, image registration of pre- and post-explosion HST images is performed. Results. Our HST astrometry confirms the location of the progenitor candidate of iPTF13bvn, and follow-up spectra securely classify this as a SN Ib. We use our hydrodynamical model to fit the observed bolometric light curve, estimating the total ejecta mass to be 1.9 solar mass and the radioactive nickel mass to be 0.05 solar mass. The model fit requires the nickel synthesized in the explosion to be highly mixed out in the ejecta. We also find that the late-time nebular r

  11. Optical photometry and spectroscopy of the low-luminosity, broad-lined Ic supernova iPTF15dld

    Science.gov (United States)

    Pian, E.; Tomasella, L.; Cappellaro, E.; Benetti, S.; Mazzali, P. A.; Baltay, C.; Branchesi, M.; Brocato, E.; Campana, S.; Copperwheat, C.; Covino, S.; D'Avanzo, P.; Ellman, N.; Grado, A.; Melandri, A.; Palazzi, E.; Piascik, A.; Piranomonte, S.; Rabinowitz, D.; Raimondo, G.; Smartt, S. J.; Steele, I. A.; Stritzinger, M.; Yang, S.; Ascenzi, S.; Della Valle, M.; Gal-Yam, A.; Getman, F.; Greco, G.; Inserra, C.; Kankare, E.; Limatola, L.; Nicastro, L.; Pastorello, A.; Pulone, L.; Stamerra, A.; Stella, L.; Stratta, G.; Tartaglia, L.; Turatto, M.

    2017-04-01

    Core-collapse stripped-envelope supernova (SN) explosions reflect the diversity of physical parameters and evolutionary paths of their massive star progenitors. We have observed the Type Ic SN iPTF15dld (z = 0.047), reported by the Palomar Transient Factory. Spectra were taken starting 20 rest-frame days after maximum luminosity and are affected by a young stellar population background. Broad spectral absorption lines associated with the SN are detected over the continuum, similar to those measured for broad-lined, highly energetic SNe Ic. The light curve and maximum luminosity are instead more similar to those of low luminosity, narrow-lined Ic SNe. This suggests a behaviour whereby certain highly stripped-envelope SNe do not produce a large amount of 56Ni, but the explosion is sufficiently energetic that a large fraction of the ejecta is accelerated to higher than usual velocities. We estimate SN iPTF15dld had a main-sequence progenitor of 20-25 M⊙, produced a 56Ni mass of ∼0.1-0.2 M⊙, had an ejecta mass of [2-10] M⊙, and a kinetic energy of [1-18] × 1051 erg.

  12. PTF11iqb: Cool supergiant mass loss that bridges the gap between Type IIn and normal supernovae

    CERN Document Server

    Smith, Nathan; Cenko, S Bradley; Kasliwal, Mansi M; Silverman, Jeffrey M; Filippenko, Alexei V; Gal-Yam, Avishay; Clubb, Kelsey I; Graham, Melissa L; Leonard, Douglas C; Horst, J Chuck; Williams, G Grant; Andrews, Jennifer E; Kulkarni, Shrinivas R; Nugent, Peter; Sullivan, Mark; Maguire, Kate; Xu, Dong; Ben-Ami, Sagi

    2015-01-01

    PTF11iqb was initially classified as a TypeIIn event caught very early after explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2, but the narrow emission weakened quickly and the spectrum morphed to resemble those of Types II-L and II-P. At late times, Halpha emission exhibited a complex, multipeaked profile reminiscent of SN1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN~1998S, although with weaker interaction with circumstellar material (CSM) at early times, and stronger CSM interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for weak CSM interaction added to the light curve of a normal SN~II-P. This plateau requires that the progenitor had an extended H envelope like a red supergia...

  13. iPTF13bvn: The first evidence of a binary progenitor for a type Ib supernova

    Energy Technology Data Exchange (ETDEWEB)

    Bersten, Melina C.; Folatelli, Gastón; Nomoto, Ken' ichi; Quimby, Robert [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Benvenuto, Omar G. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA La Plata (Argentina); Kuncarayakti, Hanindyo [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Srivastav, Shubham; Anupama, G. C.; Sahu, Devendra K., E-mail: melina.bersten@ipmu.jp [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India)

    2014-10-01

    The recent detection in archival Hubble Space Telescope images of an object at the location of supernova (SN) iPTF13bvn may represent the first direct evidence of the progenitor of a Type Ib SN. The object's photometry was found to be compatible with a Wolf-Rayet pre-SN star mass of ≈11 M {sub ☉}. However, based on hydrodynamical models, we show that the progenitor had a pre-SN mass of ≈3.5 M {sub ☉} and that it could not be larger than ≈8 M {sub ☉}. We propose an interacting binary system as the SN progenitor and perform evolutionary calculations that are able to self-consistently explain the light curve shape, the absence of hydrogen, and the pre-SN photometry. We further discuss the range of allowed binary systems and predict that the remaining companion is a luminous O-type star of significantly lower flux in the optical than the pre-SN object. A future detection of such a star may be possible and would provide the first robust identification of a progenitor system for a Type Ib SN.

  14. iPTF 13bvn: The First Evidence of a Binary Progenitor for a Type Ib Supernova

    CERN Document Server

    Bersten, Melina C; Folatelli, Gaston; Nomoto, Ken'ichi; Kuncarayakti, Hanindyo; Srivastav, Shubham; Anupama, G C; Quimby, Robert; Sahu, Devendra K

    2014-01-01

    The recent detection in archival HST images of an object at the the location of supernova (SN) iPTF~13bvn may represent the first direct evidence of the progenitor of a Type~Ib SN. The object's photometry was found to be compatible with a Wolf-Rayet pre-SN star mass of ~11 Msun. However, based on hydrodynamical models we show that the progenitor had a pre-SN mass of ~3.5 Msun and that it could not be larger than ~8 Msun. We propose an interacting binary system as the SN progenitor and perform evolutionary calculations that are able to self-consistently explain the light-curve shape, the absence of hydrogen, and the pre-SN photometry. We further discuss the range of allowed binary systems and predict that the remaining companion is a luminous O-type star of significantly lower flux in the optical than the pre-SN object. A future detection of such star may be possible and would provide the first robust progenitor identification for a Type-Ib SN.

  15. Interpreting the strongly lensed supernova iPTF16geu: time delay predictions, microlensing, and lensing rates

    CERN Document Server

    More, Anupreeta; Oguri, Masamune; More, Surhud; Lee, Chien-Hsiu

    2016-01-01

    We present predictions for time delays between multiple images of the gravitationally lensed supernova, iPTF16geu, which was recently discovered from the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type Ia where the intrinsic luminosity is usually well-known, accurately measured time delays of the multiple images could provide tight constraints on the Hubble constant. According to our lens mass models constrained by the {\\it Hubble Space Telescope} F814W image, we expect the maximum relative time delay to be less than a day, which is consistent with the maximum of 100 hours reported by Goobar et al. but places a stringent upper limit. Furthermore, the fluxes of most of the supernova images depart from expected values suggesting that they are affected by microlensing. The microlensing timescales are small enough that they may pose significant problems to measure the time delays reliably. Our lensing rate calculation indicates that the occurrence of a lensed SN in iPTF is likely. Howev...

  16. PTF 13efv - An outburst 500 days prior to the SNHunt 275 explosion and its radiative efficiency

    CERN Document Server

    Ofek, E O; Shaviv, N J; Duggan, G; Strotjohann, N -L; Rubin, A; Kulkarni, S R; Gal-Yam, A; Sullivan, M; Cao, Y; Nugent, P E; Kasliwal, M M; Sollerman, J; Fransson, C; Filippenko, A V; Perley, D A; Yaron, O; Laher, R

    2016-01-01

    The progenitors of some supernovae (SNe) exhibit outbursts with super-Eddington luminosities prior to their final explosions. This behavior is common among Type IIn SNe, but the driving mechanisms of these precursors are not yet well understood. SNHunt 275 was announced as a possible new SN during May 2015. Here we report on pre-explosion observations of the location of this event by the Palomar Transient Factory (PTF) and report the detection of a precursor about 500 days prior to the 2015 May activity (PTF 13efv). The observed velocities in the 2015 transient and its 2013 precursor absorption spectra are low (1000-2000 km/s), so it is not clear yet if the recent activity indeed marks the final disruption of the progenitor. Regardless of the nature of this event, we use the PTF photometric and spectral observations, as well as Swift-UVOT observations, to constrain the efficiency of the radiated energy relative to the total kinetic energy of the precursor. We find that, using an order-of-magnitude estimate an...

  17. VizieR Online Data Catalog: PTF 12dam & iPTF 13dcc follow-up (Vreeswijk+, 2017)

    Science.gov (United States)

    Vreeswijk, P. M.; Leloudas, G.; Gal-Yam, A.; De Cia, A.; Perley, D. A.; Quimby, R. M.; Waldman, R.; Sullivan, M.; Yan, L.; Ofek, E. O.; Fremling, C.; Taddia, F.; Sollerman, J.; Valenti, S.; Arcavi, I.; Howell, D. A.; Filippenko, A. V.; Cenko, S. B.; Yaron, O.; Kasliwal, M. M.; Cao, Y.; Ben-Ami, S.; Horesh, A.; Rubin, A.; Lunnan, R.; Nugent, P. E.; Laher, R.; Rebbapragada, U. D.; Wozniak, P.; Kulkarni, S. R.

    2017-08-01

    Spectroscopic follow-up observations of PTF 12dam were performed with the Kast Spectrograph at the Lick 3m Shane telescope, and the Low Resolution Imaging Spectrograph (LRIS) at the Keck-I 10m telescope (on Mauna Kea, Hawaii) on 2012 May 20, 21, and 22. The full spectroscopic sequence of PTF 12dam will be presented by R. M. Quimby et al. (2016, in preparation). PTF 12dam was imaged with the Palomar Oschin 48 inch (P48) (i)PTF survey telescope in the Mould R filter, the Palomar 60 inch (P60) and CCD camera in Johnson B and Sloan Digital Sky Survey (SDSS) gri, the Las Cumbres Observatory Global Telescope Network (LCOGT) in SDSS r, and LRIS mounted on the 10m Keck-I telescope in Rs. iPTF 13dcc has not had any exposure in the literature yet. It was flagged as a transient source on 2013 August 29. Spectroscopic follow-up observations spanning 2013 Nov 26 to 2014 Jan 16 were performed with the Double Spectrograph (DBSP) at the Palomar 200 inch (P200), LRIS at Keck-I, and the Inamori-Magellan Areal Camera & Spectrograph (IMACS) at the Magellan Baade telescope, showing iPTF 13dcc to be an SLSN at z=0.4305. iPTF 13dcc was imaged with the P48 Oschin (i)PTF survey telescope in the Mould R filter, the P60 in SDSS gri, the 4.3m Discovery Channel Telescope (DCT, at Lowell Observatory, Arizona) with the Large Monolithic Imager (LMI) in SDSS ri, and finally with the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide-Field Camera using filter F625W (under program GO-13858; P.I. A. De Cia). (3 data files).

  18. THE PROGENITOR OF SUPERNOVA 2011dh/PTF11eon IN MESSIER 51

    Energy Technology Data Exchange (ETDEWEB)

    Van Dyk, Schuyler D. [Spitzer Science Center/Caltech, Pasadena CA 91125 (United States); Li, Weidong; Cenko, S. Bradley; Silverman, Jeffrey M.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Kasliwal, Mansi M.; Horesh, Assaf; Ofek, Eran O.; Quimby, Robert M.; Kulkarni, Shrinivas R. [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Kraus, Adam L. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Arcavi, Iair; Gal-Yam, Avishay; Yaron, Ofer; Polishook, David, E-mail: vandyk@ipac.caltech.edu [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel)

    2011-11-10

    We have identified a luminous star at the position of supernova (SN) 2011dh/PTF11eon, in pre-SN archival, multi-band images of the nearby, nearly face-on galaxy Messier 51 (M51) obtained by the Hubble Space Telescope with the Advanced Camera for Surveys. This identification has been confirmed, to the highest available astrometric precision, using a Keck-II adaptive-optics image. The available early-time spectra and photometry indicate that the SN is a stripped-envelope, core-collapse Type IIb, with a more compact progenitor (radius {approx} 10{sup 11} cm) than was the case for the well-studied SN IIb 1993J. We infer that the extinction to SN 2011dh and its progenitor arises from a low Galactic foreground contribution, and that the SN environment is of roughly solar metallicity. The detected object has absolute magnitude M{sup 0}{sub V} Almost-Equal-To -7.7 and effective temperature {approx}6000 K. The star's radius, {approx}10{sup 13} cm, is more extended than what has been inferred for the SN progenitor. We speculate that the detected star is either an unrelated star very near the position of the actual progenitor, or, more likely, the progenitor's companion in a mass-transfer binary system. The position of the detected star in a Hertzsprung-Russell diagram is consistent with an initial mass of 17-19 M{sub Sun }. The light of this star could easily conceal, even in the ultraviolet, the presence of a stripped, compact, very hot ({approx}10{sup 5} K), nitrogen-rich Wolf-Rayet star progenitor.

  19. Optical Variability of AGNs in the PTF/iPTF Survey

    Science.gov (United States)

    Caplar, Neven; Lilly, Simon J.; Trakhtenbrot, Benny

    2017-01-01

    We characterize the optical variability of quasars in the Palomar Transient Factory and intermediate Palomar Transient Factory (PTF/iPTF) surveys. We re-calibrate the r-band light curves for ∼28,000 luminous, broad-line active galactic nuclei from the SDSS, producing a total of ∼2.4 million photometric data points. We utilize both the structure function (SF) and power spectrum density (PSD) formalisms to search for links between the optical variability and the physical parameters of the accreting supermassive black holes that power the quasars. The excess variance (SF2) of the quasar sample tends to zero at very short time separations, validating our re-calibration of the time-series data. We find that the the amplitude of variability at a given time-interval, or equivalently the timescale of variability to reach a certain amplitude, is most strongly correlated with luminosity with weak or no dependence on black hole mass and redshift. For a variability level of SF(τ) = 0.07 mag, the timescale has a dependency of τ \\propto {L}0.4. This is broadly consistent with the expectation from a simple Keplerian accretion disk model, which provides τ \\propto {L}0.5. The PSD analysis also reveals that many quasar light curves are steeper than a damped random walk. We find a correlation between the steepness of the PSD slopes, specifically the fraction of slopes steeper than 2.5, and black hole mass, although we cannot exclude the possibility that luminosity or Eddington ratio are the drivers of this effect. This effect is also seen in the SF analysis of the (i)PTF data, and in a PSD analysis of quasars in the SDSS Stripe 82.

  20. Low-Cost Planar PTF Sensors for the Identity Verification of Smartcard Holders

    NARCIS (Netherlands)

    Henderson, N.J.; Papakostas, T.V.; White, N.M.; Hartel, P.H.

    2002-01-01

    The properties of mechanical flexibility, low-cost and planar geometry make polymer thick film (PTF) sensors attractive for embedded smartcard biometrics. PTF piezoelectric and piezoresistive pressure sensors are investigated for their potential to capture spatial human characteristics. However, it

  1. Optical variability of AGN in the PTF/iPTF survey

    CERN Document Server

    Caplar, Neven; Trakhtenbrot, Benny

    2016-01-01

    We characterize the optical variability of quasars in the intermediate Palomar Transient Factory (iPTF) and Palomar Transient Factory (PTF) surveys. We re-calibrate the $r$-band light curves for $\\sim$28,000 luminous, broad-line AGNs from the SDSS, producing a total of $\\sim$2.4 million photometric data points. We utilize both the structure function (SF) and power spectrum density (PSD) formalisms to search for links between the optical variability and the physical parameters of the accreting supermassive black holes that power the quasars. The excess variance (SF$^{2}$) of the quasar sample tends to zero at very short time separations, validating our re-calibration of the time-series data. We find that the the amplitude of variability at a given time-interval, or equivalently the time-scale of variability to reach a certain amplitude, is most strongly correlated with luminosity with weak or no dependence on black hole mass and redshift. For a variability level of SF($\\tau$)=0.07 mag, the time-scale has a dep...

  2. VizieR Online Data Catalog: BVRI LCs of type Ib supernova iPTF13bvn (Folatelli+, 2016)

    Science.gov (United States)

    Folatelli, G.; van Dyk, S. D.; Kuncarayakti, H.; Maeda, K.; Bersten, M. C.; Nomoto, K.; Pignata, G.; Hamuy, M.; Quimby, R. M.; Zheng, W.; Filippenko, A. V.; Clubb, K. I.; Smith, N.; Elias-Rosa, N.; Foley, R. J.; Miller, A. A.

    2016-09-01

    We obtained deep imaging of the field of iPTF13bvn ~740 days after explosion using HST through Cycle 22 programs GO-13684 and GO-13822. Program GO-13684 was executed between 2015 June 26.37 and 26.60 (UT dates are used herein) with the Wide Field Camera 3 (WFC3) UVIS channel. Program GO-13822 comprised observations obtained on 2015 June 30.63 with WFC3/UVIS (F225W filter) and on June 30.90 UT with the Advanced Camera for Surveys (ACS; F814W filter). The supernova (SN) location in the pre- and post-explosion images was found by aligning them relative to a F555W image obtained through program GO-12888 with WFC3/UVIS on 2013 September 2.37 when the SN was still very bright. We also obtained BVRI imaging of iPTF13bvn until ~280 days with the Katzman Automatic Imaging Telescope (KAIT) and the 1m Nickel telescope at Lick Observatory (see table 3). Apparent magnitudes were first measured in the KAIT4 natural system and then transformed to the standard system using local calibrators and color terms as given in Table 4 of Ganeshalingam et al. (2010, J/ApJS/190/418). (1 data file).

  3. The disappearance of the helium-giant progenitor of the type Ib supernova iPTF13bvn and constraints on its companion

    CERN Document Server

    Eldridge, J J

    2016-01-01

    We report and discuss post-explosion observations of supernova iPTF13bvn. We find that the brightness of the SN at +740 days is below the level of the pre-explosion source and thus confirm that the progenitor star has gone. We estimate that the late-time brightness is still dominated by the supernova, which constrains the magnitude and thus mass of a possible companion star to below approximately 10Msun. In turn this implies that the progenitor's initial mass is constrained to a narrow range of between 10 to 12Msun. The progenitor of iPTF13bvn would have been a helium giant rather than a Wolf-Rayet star. In addition, we suggest that sufficiently deep observations acquired in 2016 would now stand a chance to directly observe the companion star.

  4. Discovery of a Luminous Supernova, PTF10vqv

    Science.gov (United States)

    Quimby, R. M.; Kulkarni, S.; Ofek, E.; Kasliwal, M. M.; Gal-Yam, A.; Ben-Ami, S.; Badenes, C.; Sternberg, A.; Botyanszki, J.; Nugent, P. E.; Howell, D. A.

    2010-10-01

    We report the discovery of an optical transient, PTF10vqv, in R- band images obtained with the 1.2-m Oschin telescope at Palomar Observatory in the course of the Palomar Transient Factory survey (Law et al., 2009; Rau et al., 2009).

  5. Distinct enhancers of ptf1a mediate specification and expansion of ventral pancreas in zebrafish.

    Science.gov (United States)

    Pashos, Evanthia; Park, Joon Tae; Leach, Steven; Fisher, Shannon

    2013-09-15

    Development of the pancreas and cerebellum require Pancreas-specific transcription factor-1a (Ptf1a), which encodes a subunit of the transcription factor complex PTF1. Ptf1a is required in succession for specification of the pancreas, proper allocation of pancreatic progenitors to endocrine and exocrine fates, and the production of digestive enzymes from the exocrine acini. In several neuronal structures, including the cerebellum, hindbrain, retina and spinal cord, Ptf1a is transiently expressed and promotes inhibitory neuron fates at the expense of excitatory fates. Transcription of Ptf1a in mouse is maintained in part by PTF1 acting on an upstream autoregulatory enhancer. However, the transcription factors and enhancers that initially activate Ptf1a expression in the pancreas and in certain structures of the nervous system have not yet been identified. Here we describe a zebrafish autoregulatory element, conserved among teleosts, with activity similar to that described in mouse. In addition, we performed a comprehensive survey of all non-coding sequences in a 67kb interval encompassing zebrafish ptf1a, and identified several neuronal enhancers, and an enhancer active in the ventral pancreas prior to activation of the autoregulatory enhancer. To test the requirement for autoregulatory control during pancreatic development, we restored ptf1a function through BAC transgenesis in ptf1a morphants, either with an intact BAC or one lacking the autoregulatory enhancer. We find that ptf1a autoregulation is required for development of the exocrine pancreas and full rescue of the ptf1a morphant phenotype. Similarly, we demonstrate that a ptf1a locus lacking the early enhancer region is also capable of rescue, but only supports formation of a hypoplastic exocrine pancreas. Through our dissection of the complex regulatory control of ptf1a, we identified separate cis-regulatory elements that underlie different aspects of its expression and function, and further demonstrated

  6. Optical Follow-Up Observations of PTF10qts, a Luminous Broad-Lined Type Ic Supernova Found by the Palomar Transient Factory

    Science.gov (United States)

    Walker, E. S.; Mazzali, P. A.; Pian, E.; Hurley, K.; Arcavi, I.; Cenko, S. B.; Gal-Yam, A.; Horesh, A.; Kasliwal, M.; Poznanski, D.; Silverman, J. M.; Barthelmy, S.

    2014-01-01

    We present optical photometry and spectroscopy of the broad-lined Type Ic supernova (SN Ic-BL) PTF10qts, which was discovered as part of the Palomar Transient Factory. The supernova was located in a dwarf galaxy of magnitude r = 21.1 at a redshift z = 0.0907.We find that the R-band light curve is a poor proxy for bolometric data and use photometric and spectroscopic data to construct and constrain the bolometric light curve. The derived bolometric magnitude at maximum light is Mbol = -18.51 +/- 0.2 mag, comparable to that of SN1998bw (Mbol = -18.7 mag) which was associated with a gamma-ray burst (GRB). PTF10qts is one of the most luminous SN Ic-BL observed without an accompanying GRB. We estimate the physical parameters of the explosion using data from our programme of follow-up observations, finding that it produced a larger mass of radioactive nickel compared to other SNeIc-BL with similar inferred ejecta masses and kinetic energies. The progenitor of the event was likely a approximately 20 solar mass star.

  7. Discovery of a Super-Luminous Supernova, PTF12dam

    Science.gov (United States)

    Quimby, R. M.; Arcavi, I.; Sternberg, A.; Ben-Ami, S.; Yaron, O.; Gal-Yam, A.; Graham, M.; Cenko, S. B.; Filippenko, A. V.; Perley, D.; Cao, Y.; Kulkarni, S. R.

    2012-05-01

    The Palomar Transient Factory (harvard.edu/abs/2009PASP..121.1395L'>Law et al., 2009; harvard.edu/abs/2009PASP..121.1334R'>Rau et al., 2009) reports the discovery of an optical transient, PTF12dam. The source is located at RA = 14:24:46.20, Dec. = +46:13:48.3 (J2000), which is offset from a r=19.15 mag galaxy detected by the SDSS.

  8. Discovery of a Luminous Supernova, PTF11rks

    Science.gov (United States)

    Quimby, R. M.; Gal-Yam, A.; Arcavi, I.; Yaron, O.; Horesh, A.; Mooley, K.

    2011-12-01

    The Palomar Transient Factory (harvard.edu/abs/2009PASP..121.1395L'>Law et al., 2009; harvard.edu/abs/2009PASP..121.1334R'>Rau et al., 2009) reports the discovery of an optical transient, PTF11rks. The source is located at RA = 01:39:45.51, Dec. = +29:55:27.0 (J2000), which is offset from a faint (r~20.9 mag) galaxy detected by the SDSS.

  9. The PTF Orion Project: Eclipsing Binaries and Young Stellar Objects

    CERN Document Server

    van Eyken, Julian C; Rebull, Luisa M; Stauffer, John R; Akeson, Rachel L; Beichman, Charles A; Boden, Andrew F; von Braun, Kaspar; Gelino, Dawn M; Hoard, D W; Howell, Steve B; Kane, Stephen R; Plavchan, Peter; Ramírez, Solange V; Bloom, Joshua S; Cenko, S Bradley; Kasliwal, Mansi M; Kulkarni, Shrinivas R; Law, Nicholas M; Nugent, Peter E; Ofek, Eran O; Poznanski, Dovi; Quimby, Robert M; Grillmair, Carl J; Laher, Russ; Levitan, David; Mattingly, Sean; Surace, Jason A

    2011-01-01

    The Palomar Transient Factory (PTF) Orion project is an experiment within the broader PTF survey, a systematic automated exploration of the sky for optical transients. Taking advantage of the wide field of view available using the PTF camera at the Palomar 48" telescope, 40 nights were dedicated in December 2009-January 2010 to perform continuous high-cadence differential photometry on a single field containing the young (7-10Myr) 25 Ori association. The primary motivation for the project is to search for planets around young stars in this region. The unique data set also provides for much ancillary science. In this first paper we describe the survey and data reduction pipeline, and present initial results from an inspection of the most clearly varying stars relating to two of the ancillary science objectives: detection of eclipsing binaries and young stellar objects. We find 82 new eclipsing binary systems, 9 of which we are candidate 25 Ori- or Orion OB1a-association members. Of these, 2 are potential young...

  10. PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula

    CERN Document Server

    Covey, Kevin R; Miller, Adam A; Poznanski, Dovi; Cenko, S Bradley; Silverman, Jeffrey M; Bloom, Joshua S; Kasliwal, Mansi M; Fischer, William; Rayner, John; Rebull, Luisa M; Butler, Nathaniel R; Filippenko, Alexei V; Law, Nicholas M; Ofek, Eran O; Agueros, Marcel; Dekany, Richard G; Rahmer, Gustavo; Hale, David; Smith, Roger; Quimby, Robert M; Nugent, Peter; Jacobsen, Janet; Zolkower, Jeff; Velur, Viswa; Walters, Richard; Henning, John; Bui, Khanh; McKenna, Dan; Kulkarni, Shrinivas R; Klein, Christopher

    2010-01-01

    During a synoptic survey of the North American Nebula region, the Palomar Transient Factory (PTF) detected an optical outburst (dubbed PTF10nvg) associated with the previously unstudied flat or rising spectrum infrared source IRAS 20496+4354. The PTF R-band light curve reveals that PTF10nvg brightened by more than 5 mag during the current outburst, rising to a peak magnitude of R~13.5 in 2010 Sep. Follow-up observations indicate PTF10nvg has undergone a similar ~5 mag brightening in the K band, and possesses a rich emission-line spectrum, including numerous lines commonly assumed to trace mass accretion and outflows. Many of these lines are blueshifted by ~175 km/s from the North American Nebula's rest velocity, suggesting that PTF10nvg is driving an outflow. Optical spectra of PTF10nvg show several TiO/VO bandheads fully in emission, indicating the presence of an unusual amount of dense (> 10^10 cm^-3), warm (1500-4000 K) circumstellar material. Near-infrared spectra of PTF10nvg appear quite similar to a spe...

  11. FIRE Classification of iPTF13bvn

    Science.gov (United States)

    Kasliwal, M. M.; Degenaar, N.; Polishook, D.

    2013-06-01

    We observed iPTF13bvn (ATEL#5137) with the Folded-port InfraRed Echellette (FIRE; Simcoe et al. 2010) spectrograph on the Magellan Baade telescope on UT 2013 Jun 19.04. The spectrum covers 0.8 to 2.5um and shows prominent P Cygni profile of Helium I at 1.083 um at avelocity of 23000 km/s. We note that the 2um Helium I line is relatively weak. Confirming the tentative classification based on the optical spectrum (ATEL#5142), we conclude this is a supernova of Type Ib.

  12. SN Refsdal

    DEFF Research Database (Denmark)

    Kelly, P. L.; Brammer, G.; Selsing, J.;

    2015-01-01

    in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, SN Refsdal has a blue B-V color and a high luminosity for the assumed range of potential magnifications. If SN Refsdal can be modeled as a scaled version of SN...

  13. The detection rate of early UV emission from supernovae: A dedicated GALEX/PTF survey and calibrated theoretical estimates

    CERN Document Server

    Ganot, Noam; Ofek, Eran O; Sagiv, Ilan; Waxman, Eli; Lapid, Ofer; Kulkarni, Shrinivas R; Ben-Ami, Sagi; Kasliwal, Mansi M; Chelouche, Doron; Rafter, Stephen; Behar, Ehud; Laor, Ari; Poznanski, Dovi; Nakar, Udi; Maoz, Dan; Trakhtenbrot, Benny; Neill, James D; Barlow, Thomas A; Martin, Christofer D; Gezari, Suvi; Arcavi, Iair; Bloom, Joshua s; Nugent, Peter E; Sullivan, Mark

    2014-01-01

    The radius and surface composition of an exploding massive star, as well as the explosion energy per unit mass, can be measured using early UV observations of core collapse supernovae (SNe). We present the first results from a simultaneous GALEX/PTF search for early UV emission from SNe. Six Type II SNe and one Type II superluminous SN (SLSN-II) are clearly detected in the GALEX NUV data. We compare our detection rate with theoretical estimates based on early, shock-cooling UV light curves calculated from models that fit existing Swift and GALEX observations well, combined with volumetric SN rates. We find that our observations are in good agreement with calculated rates assuming that red supergiants (RSGs) explode with fiducial radii of 500 R_solar, explosion energies of 10^51 erg, and ejecta masses of 10 M_solar. Exploding blue supergiants and Wolf-Rayet stars are poorly constrained. We describe how such observations can be used to derive the progenitor radius, surface composition and explosion energy per u...

  14. The Detection of a SN IIn in Optical Follow-Up Observations of IceCube Neutrino Events

    OpenAIRE

    Aartsen, M. G.; Abraham, K; Arguelles, C.; Grant, D.; Gretskov, P.; Groh, J. C.; Gross, A.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansmann, B.; Arlen, T. C.; Hanson, K.

    2015-01-01

    The IceCube neutrino observatory pursues a follow-up program selecting interesting neutrino events in real-time and issuing alerts for electromagnetic follow-up observations. In 2012 March, the most significant neutrino alert during the first three years of operation was issued by IceCube. In the follow-up observations performed by the Palomar Transient Factory (PTF), a Type IIn supernova (SN IIn) PTF12csy was found 0.degrees 2 away from the neutrino alert direction, with an error radius of 0...

  15. A Turkish newborn infant with cerebellar agenesis/neonatal diabetes mellitus and PTF1A mutation.

    Science.gov (United States)

    Tutak, E; Satar, M; Yapicioğlu, H; Altintaş, A; Narli, N; Hergüner, O; Bayram, Y

    2009-01-01

    Classical neonatal diabetes mellitus is defined as hyperglycemia that occurs within the first month of life in term infants. It can be either permanent or transient. Cerebellar agenesis and permanent neonatal diabetes has been previously reported as a new autosomal recessive disorder. Pancreas Transcription Factor 1 Alpha (PTF1A) mutations have been related with this constellation of abnormalities. Here we report a new case of cerebellar agenesis and neonatal diabetes mellitus whose parents are PTF1A mutation carriers.

  16. Optical Follow-Up Observations of PTF10qts, a Luminous Broad-Lined Type Ic Supernova Found by the Palomar Transient Factory

    CERN Document Server

    Walker, E S; Pian, E; Hurley, K; Arcavi, I; Cenko, S B; Gal-Yam, A; Horesh, A; Kasliwal, M; Poznanski, D; Silverman, J M; Sullivan, M; Bloom, J S; Filippenko, A V; Kulkarni, S R; Nugent, P E; Ofek, E; Barthelmy, S; Boynton, W; Goldsten, J; Golenetskii, S; Ohno, M; Tashiro, M S; Yamaoka, K; Zhang, X L-

    2014-01-01

    We present optical photometry and spectroscopy of the broad-lined Type Ic supernova (SNIc-BL) PTF10qts, which was discovered as part of the Palomar Transient Factory. The supernova was located in a dwarf galaxy of magnitude $r=21.1$ at a redshift $z=0.0907$. We find that the $R$-band light curve is a poor proxy for bolometric data and use photometric and spectroscopic data to construct and constrain the bolometric light curve. The derived bolometric magnitude at maximum light is $M_{\\rm bol} = -18.51\\pm0.2$ mag, comparable to that of SN 1998bw ($M_{\\rm bol} = -18.7$ mag) which was associated with a gamma-ray burst (GRB). PTF10qts is one of the most luminous SNIc-BL observed without an accompanying GRB. We estimate the physical parameters of the explosion using data from our programme of follow-up observations, finding that it produced a larger mass of radioactive nickel compared to other SNeIc-BL with similar inferred ejecta masses and kinetic energies. The progenitor of the event was likely a $\\sim20$M$_{\\od...

  17. Correlation Study of PtfV1 with Heart-Qi Deficiency Syndrome in Patients with Hypertensive Left Ventricular Hypertrophy

    Institute of Scientific and Technical Information of China (English)

    杨传华; 陆峰

    2002-01-01

    @@ It is generally believed that the change of p-wave terminal force in lead V1 (PtfV1) is associated with the inner diameter of left atrium, left ventricular compliance,and ventricular diastolic function. The increase of negative value of PtfV1 in essential hypertensive (EH) patients with left ventricular hypertrophy (LVH) indicates the cardiac function may be damaged. In order to explore the relationship between Heart-Qi Deficiency Syndrome (HQDS) of TCM and PtfV1 level in hypertensive LVH patients, correlation analysis of scores of Heart-Qi Deficiency Syndrome and negative value of PtfV1 was made by the authors.

  18. Program Specificity for Ptf1a in Pancreas versus Neural Tube Development Correlates with Distinct Collaborating Cofactors and Chromatin Accessibility

    Science.gov (United States)

    Meredith, David M.; Borromeo, Mark D.; Deering, Tye G.; Casey, Bradford H.; Savage, Trisha K.; Mayer, Paul R.; Hoang, Chinh; Tung, Kuang-Chi; Kumar, Manonmani; Shen, Chengcheng; Swift, Galvin H.

    2013-01-01

    The lineage-specific basic helix-loop-helix transcription factor Ptf1a is a critical driver for development of both the pancreas and nervous system. How one transcription factor controls diverse programs of gene expression is a fundamental question in developmental biology. To uncover molecular strategies for the program-specific functions of Ptf1a, we identified bound genomic regions in vivo during development of both tissues. Most regions bound by Ptf1a are specific to each tissue, lie near genes needed for proper formation of each tissue, and coincide with regions of open chromatin. The specificity of Ptf1a binding is encoded in the DNA surrounding the Ptf1a-bound sites, because these regions are sufficient to direct tissue-restricted reporter expression in transgenic mice. Fox and Sox factors were identified as potential lineage-specific modifiers of Ptf1a binding, since binding motifs for these factors are enriched in Ptf1a-bound regions in pancreas and neural tube, respectively. Of the Fox factors expressed during pancreatic development, Foxa2 plays a major role. Indeed, Ptf1a and Foxa2 colocalize in embryonic pancreatic chromatin and can act synergistically in cell transfection assays. Together, these findings indicate that lineage-specific chromatin landscapes likely constrain the DNA binding of Ptf1a, and they identify Fox and Sox gene families as part of this process. PMID:23754747

  19. Physiochemical characterization and antimicrobial evaluation of phenylthiourea-formaldehyde polymer (PTF) based polymeric ligand and its polymer metal complexes

    Science.gov (United States)

    Ahamad, Tansir; Alshehri, Saad M.

    2013-05-01

    Phenylthiourea-formaldehyde polymer (PTF) has been synthesized via polycondensation of phenylthiourea and formaldehyde in basic medium and its corresponding metal complexes [PTF-M(II)] were prepared with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ions. The synthesized polymers have been characterized by elemental analysis, magnetic susceptibility, UV-visible, FT-IR, 1H NMR, 13C NMR, ESR spectroscopy and thermogravimetric analysis (TGA). Elemental analysis, electronic spectra and magnetic moment measurement indicate that PTF-Mn(II), PTF-Co(II) and PTF-Ni(II) show octahedral geometry, while PTF-Cu(II) and PTF-Zn(II) show square planar and tetrahedral geometry, respectively. The results of TGA ascribed that all the PTF-M(II) showed better heat-resistance properties than PTF resin. In vitro antimicrobial activities were performed against several bacteria and fungi using agar well diffusion method. The results of microbial activity were compared with Kanamycin and Miconazole as standard antibiotics for antibacterial and antifungal activities respectively.

  20. Ptf1a triggers GABAergic neuronal cell fates in the retina

    Directory of Open Access Journals (Sweden)

    Parain Karine

    2007-10-01

    Full Text Available Abstract Background In recent years, considerable knowledge has been gained on the molecular mechanisms underlying retinal cell fate specification. However, hitherto studies focused primarily on the six major retinal cell classes (five types of neurons of one type of glial cell, and paid little attention to the specification of different neuronal subtypes within the same cell class. In particular, the molecular machinery governing the specification of the two most abundant neurotransmitter phenotypes in the retina, GABAergic and glutamatergic, is largely unknown. In the spinal cord and cerebellum, the transcription factor Ptf1a is essential for GABAergic neuron production. In the mouse retina, Ptf1a has been shown to be involved in horizontal and most amacrine neurons differentiation. Results In this study, we examined the distribution of neurotransmitter subtypes following Ptf1a gain and loss of function in the Xenopus retina. We found cell-autonomous dramatic switches between GABAergic and glutamatergic neuron production, concomitant with profound defects in the genesis of amacrine and horizontal cells, which are mainly GABAergic. Therefore, we investigated whether Ptf1a promotes the fate of these two cell types or acts directly as a GABAergic subtype determination factor. In ectodermal explant assays, Ptf1a was found to be a potent inducer of the GABAergic subtype. Moreover, clonal analysis in the retina revealed that Ptf1a overexpression leads to an increased ratio of GABAergic subtypes among the whole amacrine and horizontal cell population, highlighting its instructive capacity to promote this specific subtype of inhibitory neurons. Finally, we also found that within bipolar cells, which are typically glutamatergic interneurons, Ptf1a is able to trigger a GABAergic fate. Conclusion Altogether, our results reveal for the first time in the retina a major player in the GABAergic versus glutamatergic cell specification genetic pathway.

  1. A DOUBLE NEUTRON STAR MERGER ORIGIN FOR THE COSMOLOGICAL RELATIVISTIC FADING SOURCE PTF11agg?

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xue-Feng; Gao, He; Ding, Xuan [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang, Bing [Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, NV 89154 (United States); Dai, Zi-Gao [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Wei, Jian-Yan, E-mail: xfwu@pmo.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-01-20

    The Palomar Transient Factory (PTF) team recently reported the discovery of a rapidly fading optical transient source, PTF11agg. A long-lived scintillating radio counterpart was identified, but the search for a high-energy counterpart showed negative results. The PTF team speculated that PTF11agg may represent a new class of relativistic outbursts. Here we suggest that a neutron star (NS)-NS merger system with a supra-massive magnetar central engine could be a possible source to power such a transient, if our line of sight is not on the jet axis direction of the system. These systems are also top candidates for gravitational wave sources to be detected in the advanced LIGO/Virgo era. We find that the PTF11agg data could be explained well with such a model, suggesting that at least some gravitational wave bursts due to NS-NS mergers may be associated with such a bright electromagnetic counterpart without a γ-ray trigger.

  2. A novel subset of enteric neurons revealed by ptf1a:GFP in the developing zebrafish enteric nervous system.

    Science.gov (United States)

    Uribe, Rosa A; Gu, Tiffany; Bronner, Marianne E

    2016-03-01

    The enteric nervous system, the largest division of the peripheral nervous system, is derived from vagal neural crest cells that invade and populate the entire length of the gut to form diverse neuronal subtypes. Here, we identify a novel population of neurons within the enteric nervous system of zebrafish larvae that express the transgenic marker ptf1a:GFP within the midgut. Genetic lineage analysis reveals that enteric ptf1a:GFP(+) cells are derived from the neural crest and that most ptf1a:GFP(+) neurons express the neurotransmitter 5HT, demonstrating that they are serotonergic. This transgenic line, Tg(ptf1a:GFP), provides a novel neuronal marker for a subpopulation of neurons within the enteric nervous system, and highlights the possibility that Ptf1a may act as an important transcription factor for enteric neuron development.

  3. SN Refsdal

    DEFF Research Database (Denmark)

    Kelly, P. L.; Brammer, G.; Selsing, J.;

    2016-01-01

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in Fall 2014. The HST light curve of SN Refsdal matches the distinctive, slowly rising light curves of SN 1987A-like supernovae...

  4. SN 2000cx and SN 2013bh: Extremely Rare, Nearly Twin Type Ia Supernovae

    CERN Document Server

    Silverman, Jeffrey M; Kasliwal, Mansi M; Fox, Ori D; Cao, Yi; Johansson, Joel; Perley, Daniel A; Tal, David; Wheeler, J Craig; Amanullah, Rahman; Arcavi, Iair; Bloom, Joshua S; Gal-Yam, Avishay; Goobar, Ariel; Kulkarni, Shrinivas R; Laher, Russ; Lee, William H; Marion, G H; Nugent, Peter E; Shivvers, Isaac

    2013-01-01

    The Type Ia supernova (SN Ia) SN 2000cx was one of the most peculiar transients ever discovered. While its rise to maximum brightness was typical for a SN Ia, its decline was slower, causing standard light curve fitting algorithms to fail; its spectra indicated a high photospheric temperature. Thirteen years later SN 2013bh (aka iPTF13abc), the first near identical twin of SN 2000cx, was discovered. We obtained optical and near-IR photometry and low-resolution optical spectroscopy of this object from discovery until about 1 month past r-band maximum brightness. The spectra of both objects indicate the presence of iron-group elements (Co II, Ni II, Fe II, Fe III, and high-velocity features [HVFs] of Ti II), intermediate-mass elements (Si II, Si III, and S II), in addition to separate normal velocity features (~12000 km/s) and HVFs (~24000 km/s) of Ca II. Persistent absorption from Fe III and Si III, along with the colour evolution, imply relatively high blackbody temperatures for SNe 2013bh and 2000cx (~12000 ...

  5. PTF, a new facility for pulse field testing of large scale superconducting cables and joints

    NARCIS (Netherlands)

    Smith, Bradford A.; Hale, J. Richard; Zhukovsky, Alex; Michael, Philip C.; Minervini, Joseph V.; Olmstead, Michael M.; Dekow, Gary L.; Rosati, James; Camille, Richard J.; Gung, Chen-yu; Gwinn, David; Silva, Frank; Fairfax, Stephen A.; Shen, Stewart; Knoopers, H.G.; Wessel, S.; Krooshoop, H.J.G.; Shevchenko, O.A.; Godeke, A.; Kate, ten H.H.J.

    1997-01-01

    A magnetic Pulse Test Facility (PTF), in which samples of CICC electrical joints from each ITER home team will be tested, has been fabricated at the MIT Plasma Fusion Center under an ITER task agreement. Construction of this facility has recently been completed, and an initial test phase on the firs

  6. A Triple-energy-source Model for Superluminous Supernova iPTF13ehe

    Science.gov (United States)

    Wang, S. Q.; Liu, L. D.; Dai, Z. G.; Wang, L. J.; Wu, X. F.

    2016-09-01

    Almost all superluminous supernovae (SLSNe) whose peak magnitudes are ≲ -21 mag can be explained by the 56Ni-powered model, the magnetar-powered (highly magnetized pulsar) model, or the ejecta-circumstellar medium (CSM) interaction model. Recently, iPTF13ehe challenged these energy-source models, because the spectral analysis shows that ˜ 2.5{M}⊙ of 56Ni have been synthesized, but are inadequate to power the peak bolometric emission of iPTF13ehe, while the rebrightening of the late-time light curve (LC) and the Hα emission lines indicate that the ejecta-CSM interaction must play a key role in powering the late-time LC. Here we propose a triple-energy-source model, in which a magnetar together with some amount (≲ 2.5{M}⊙ ) of 56Ni may power the early LC of iPTF13ehe, while the late-time rebrightening can be quantitatively explained by an ejecta-CSM interaction. Furthermore, we suggest that iPTF13ehe is a genuine core-collapse supernova rather than a pulsational pair-instability supernova candidate. Further studies on similar SLSNe in the future would eventually shed light on their explosion and energy-source mechanisms.

  7. PTF; a new facility for pulse field testing of large scale superconducting

    NARCIS (Netherlands)

    Smith, Bradford A.; Hale, J. Richard; Zhukovsky, Alex; Michael, Philip C.; Minervini, Joseph V.; Olmstead, Michael M.; Dekow, Gary L.; Rosati, James; Camille, Richard J.; Gung, Chen-yu; Gwinn, David; Silva, Frank; Fairfax, Stephen A.; Shen, Stewart; Knoopers, H.G.; Wessel, Wilhelm A.J.; Krooshoop, Hendrikus J.G.; Chevtchenko, O.A.; Godeke, A.; ten Kate, Herman H.J.

    1997-01-01

    A magnetic Pulse Test Facility (PTF), in which samples of CICC electrical joints from each ITER home team will be tested, has been fabricated at the MIT Plasma Fusion Center under an ITER task agreement. Construction of this facility has recently been completed, and an initial test phase on the

  8. iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar

    Science.gov (United States)

    Gezari, S.; Hung, T.; Cenko, S. B.; Blagorodnova, N.; Yan, Lin; Kulkarni, S. R.; Mooley, K.; Kong, A. K. H.; Cantwell, T. M.; Yu, P. C.; Cao, Y.; Fremling, C.; Neill, J. D.; Ngeow, C.-C.; Nugent, P. E.; Wozniak, P.

    2017-02-01

    We present a radio-quiet quasar at z = 0.237 discovered “turning on” by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucleus of a galaxy with an archival Sloan Digital Sky Survey spectrum with weak narrow-line emission characteristic of a low-ionization nuclear emission-line region (LINER). Our follow-up spectra show the dramatic appearance of broad Balmer lines and a power-law continuum characteristic of a luminous ({L}{bol}≈ {10}45 erg s‑1) type 1 quasar 12 yr later. Our photometric monitoring with PTF from 2009–2012 and serendipitous X-ray observations from the XMM-Newton Slew Survey in 2011 and 2015 constrain the change of state to have occurred less than 500 days before the iPTF detection. An enhanced broad Hα/[O iii] λ5007 line ratio in the type 1 state relative to other changing-look quasars also is suggestive of the most rapid change of state yet observed in a quasar. We argue that the >10 increase in Eddington ratio inferred from the brightening in UV and X-ray continuum flux is more likely due to an intrinsic change in the accretion rate of a preexisting accretion disk than an external mechanism such as variable obscuration, microlensing, or the tidal disruption of a star. However, further monitoring will be helpful in better constraining the mechanism driving this change of state. The rapid “turn-on” of the quasar is much shorter than the viscous infall timescale of an accretion disk and requires a disk instability that can develop around a ∼ {10}8 {M}ȯ black hole on timescales less than 1 yr.

  9. Ectopic Ptf1a expression in murine ESCs potentiates endocrine differentiation and models pancreas development in vitro.

    Science.gov (United States)

    Nair, Gopika G; Vincent, Robert K; Odorico, Jon S

    2014-05-01

    Besides its role in exocrine differentiation, pancreas-specific transcription factor 1a (PTF1a) is required for pancreas specification from the foregut endoderm and ultimately for endocrine cell formation. Examining the early role of PTF1a in pancreas development has been challenging due to limiting amounts of embryonic tissue material for study. Embryonic stem cells (ESCs) which can be differentiated in vitro, and without limit to the amount of experimental material, can serve as a model system to study these early developmental events. To this end, we derived and characterized a mouse ESC line with tetracycline-inducible expression of PTF1a (tet-Ptf1a mESCs). We found that transient ectopic expression of PTF1a initiated the pancreatic program in differentiating ESCs causing cells to activate PDX1 expression in bud-like structures resembling pancreatic primordia in vivo. These bud-like structures also expressed progenitor markers characteristic of a developing pancreatic epithelium. The epithelium differentiated to generate a wave of NGN3+ endocrine progenitors, and further formed cells of all three pancreatic lineages. Notably, the insulin+ cells in the cultures were monohormonal, and expressed PDX1 and NKX6.1. PTF1a-induced cultures differentiated into significantly more endocrine and exocrine cells and the ratio of endocrine-to-exocrine cell differentiation could be regulated by retinoic acid (RA) and nicotinamide (Nic) signaling. Moreover, induced cultures treated with RA and Nic exhibited a modest glucose response. Thus, this tet-Ptf1a ESC-based in vitro system is a valuable new tool for interrogating the role of PTF1a in pancreas development and in directing differentiation of ESCs to endocrine cells.

  10. Specification of spatial identities of cerebellar neuron progenitors by ptf1a and atoh1 for proper production of GABAergic and glutamatergic neurons.

    Science.gov (United States)

    Yamada, Mayumi; Seto, Yusuke; Taya, Shinichiro; Owa, Tomoo; Inoue, Yukiko U; Inoue, Takayoshi; Kawaguchi, Yoshiya; Nabeshima, Yo-Ichi; Hoshino, Mikio

    2014-04-01

    In the cerebellum, the bHLH transcription factors Ptf1a and Atoh1 are expressed in distinct neuroepithelial regions, the ventricular zone (VZ) and the rhombic lip (RL), and are required for producing GABAergic and glutamatergic neurons, respectively. However, it is unclear whether Ptf1a or Atoh1 is sufficient for specifying GABAergic or glutamatergic neuronal fates. To test this, we generated two novel knock-in mouse lines, Ptf1a(Atoh1) and Atoh1(Ptf1a), that are designed to express Atoh1 and Ptf1a ectopically in the VZ and RL, respectively. In Ptf1a(Atoh1) embryos, ectopically Atoh1-expressing VZ cells produced glutamatergic neurons, including granule cells and deep cerebellar nuclei neurons. Correspondingly, in Atoh1(Ptf1a) animals, ectopically Ptf1a-expressing RL cells produced GABAergic populations, such as Purkinje cells and GABAergic interneurons. Consistent results were also obtained from in utero electroporation of Ptf1a or Atoh1 into embryonic cerebella, suggesting that Ptf1a and Atoh1 are essential and sufficient for GABAergic versus glutamatergic specification in the neuroepithelium. Furthermore, birthdating analyses with BrdU in the knock-in mice or with electroporation studies showed that ectopically produced fate-changed neuronal types were generated at temporal schedules closely simulating those of the wild-type RL and VZ, suggesting that the VZ and RL share common temporal information. Observations of knock-in brains as well as electroporated brains revealed that Ptf1a and Atoh1 mutually negatively regulate their expression, probably contributing to formation of non-overlapping neuroepithelial domains. These findings suggest that Ptf1a and Atoh1 specify spatial identities of cerebellar neuron progenitors in the neuroepithelium, leading to appropriate production of GABAergic and glutamatergic neurons, respectively.

  11. VizieR Online Data Catalog: Light curves of four transients from PTF & SNLS (Arcavi+, 2016)

    Science.gov (United States)

    Arcavi, I.; Wolf, W. M.; Howell, D. A.; Bildsten, L.; Leloudas, G.; Hardin, D.; Prajs, S.; Perley, D. A.; Svirski, G.; Gal-Yam, A.; Katz, B.; McCully, C.; Cenko, S. B.; Lidman, C.; Sullivan, M.; Valenti, S.; Astier, P.; Balland, C.; Carlberg, R. G.; Conley, A.; Fouchez, D.; Guy, J.; Pain, R.; Palanque-Delabrouille, N.; Perrett, K.; Pritchet, C. J.; Regnault, N.; Rich, J.; Ruhlmann-Kleider, V.

    2016-05-01

    PTF10iam was discovered by the Palomar 48 inch Oschin Schmidt telescope (P48) as part of the PTF survey. The three Supernova Legacy Survey (SNLS; Astier et al. 2006A&A...447...31A) events (SNLS04D4ec, SNLS05D2bk and SNLS06D1hc) were discovered by the deep survey of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS 2002), using the CFHT 3.6m telescope. The SNLS host-galaxy magnitudes were obtained from the SNLS five-year imaging data set (D. Hardin et al. 2016, in preparation), following the general method described in Kronborg et al. (2010A&A...514A..44K). In short, photometry was performed on deep image stacks in the ugriz CFHT/Megacam filters. (2 data files).

  12. VizieR Online Data Catalog: Rotation periods of asteroids using iPTF (Chang+, 2016)

    Science.gov (United States)

    Chang, C.-K.; Lin, H.-W.; Ip, W.-H.; Prince, T. A.; Kulkarni, S. R.; Levitan, D.; Laher, R.; Surace, J.

    2017-01-01

    To explore the transient and variable sky synoptically, the PTF/iPTF employs the Palomar 48-inch Oschin Schmidt Telescope to create a field of view of ~7.26deg2 and a pixel scale of 1.01". The available filters include the Mould-R band, with which most exposures were taken, Gunn-g', and two different Hα-bands. The exposure time is fixed at 60 seconds, which can reach a median limiting magnitude of R~21mag at the 5σ level. In order to look for large super-fast rotators, we conducted five asteroid rotation-period surveys during 2014 October 29-31 and November 10-13, and 2015 January 18-19, February 20-21 and 25-26. Each survey continuously scanned six consecutive PTF fields over the ecliptic plane in the R-band, with a cadence of 10min. We ended up with a total sky coverage of ~188deg2. (3 data files).

  13. A Machine-learning Model to Separate Stars and Galaxies in iPTF Images

    Science.gov (United States)

    Miller, Adam; Kulkarni, Maya; Prince, Thomas A.; Intermediate Palomar Transient Factory

    2016-01-01

    The Intermediate Palomar Transient Factory (iPTF) is a dedicated time-domain survey optimized for the rapid characterization of fast transients. While significant efforts have been devoted to the development of software that quickly and reliably identifies new transients, there are currently no mechanisms to automatically classify these sources. The first component in deriving a classification is understanding whether or not the newly discovered transient is galactic or extragalactic in its origin. Here, we present our development of a new framework for classifying sources in iPTF reference images as either stars or galaxies. The framework utilizes the random forest algorithm and is trained with nearly 3 million sources that have Sloan Digital Sky Survey (SDSS) spectra. The final optimized model achieves a cross-validation accuracy of ~96%, which represents a significant improvement over the automated classification provided by the SExtractor algorithm. This accuracy, while slightly worse than that provided by the SDSS photometric classifier, can be extended over the entire iPTF footprint, which covers >5000 deg^2 that have not been imaged by SDSS. Associating transients with galactic or extragalactic origin is the first step in delivering automated classifications of newly discovered transients.

  14. iPTF14yb: The First Discovery of a GRB Afterglow Independent of a High-Energy Trigger

    CERN Document Server

    Cenko, S Bradley; Perley, Daniel A; Horesh, Assaf; Corsi, Alessandra; Fox, Derek B; Cao, Yi; Kasliwal, Mansi M; Lien, Amy; Arcavi, Iair; Bloom, Joshua S; Butler, Nat R; Cucchiara, Antonino; de Diego, Jose A; Filippenko, Alexei V; Gal-Yam, Avishay; Gehrels, Neil; Georgiev, Leonid; Gonzalez, J Jesus; Graham, John F; Greiner, Jochen; Kann, D Alexander; Klein, Christopher R; Knust, Fabian; Kulkarni, S R; Kutyrev, Alexander; Laher, Russ; Lee, William H; Nugent, Peter E; Prochaska, J Xavier; Ramirez-Ruiz, Enrico; Richer, Michael G; Rubin, Adam; Urata, Yuji; Varela, Karla; Watson, Alan M; Wozniak, Przemek R

    2015-01-01

    We report here the discovery by the Intermediate Palomar Transient Factory (iPTF) of iPTF14yb, a luminous ($M_{r}\\approx-27.8$ mag), cosmological (redshift 1.9733), rapidly fading optical transient. We demonstrate, based on probabilistic arguments and a comparison with the broader population, that iPTF14yb is the optical afterglow of the long-duration gamma-ray burst GRB 140226A. This marks the first unambiguous discovery of a GRB afterglow prior to (and thus entirely independent of) an associated high-energy trigger. We estimate the rate of iPTF14yb-like sources (i.e., cosmologically distant relativistic explosions) based on iPTF observations, inferring an all-sky value of $\\Re_{\\mathrm{rel}}=610$ yr$^{-1}$ (68% confidence interval of 110-2000 yr$^{-1}$). Our derived rate is consistent (within the large uncertainty) with the all-sky rate of on-axis GRBs derived by the Swift satellite. Finally, we briefly discuss the implications of the nondetection to date of bona fide "orphan" afterglows (i.e., those lackin...

  15. VizieR Online Data Catalog: PTF obs. of a precursor to SNHunt 275 2015 May event (Ofek+, 2016)

    Science.gov (United States)

    Ofek, E. O.; Cenko, S. B.; Shaviv, N. J.; Duggan, G.; Strotjohann, N.-L.; Rubin, A.; Kulkarni, S. R.; Gal-Yam, A.; Sullivan, M.; Cao, Y.; Nugent, P. E.; Kasliwal, M. M.; Sollerman, J.; Fransson, C.; Filippenko, A. V.; Perley, D. A.; Yaron, O.; Laher, R.

    2016-08-01

    The Palomar Transient Factory (PTF and iPTF; Law et al. 2009PASP..121.1395L; Rau et al. 2009PASP..121.1334R), using the 48inch Oschin Schmidt telescope, observed the field of SNHunt 275 starting in 2009 March. On 2013 December 12, PTF detected a new source at the location of the event, and the transient was named PTF 13efv (see Figure 1). Three images obtained between 2014 January 23 and April 25 were used as a reference. The PTF R-band photometry is listed in Table1. Most of the optical spectra were obtained with the Low Resolution Imaging Spectrometer (LRIS) on the Keck I 10m telescope, although a few spectra were also taken with the DEep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II 10m telescope, the Kast spectrograph on the Shane 3m telescope at Lick Observatory, and the Gemini-North Multiobject Spectrograph (GMOS) on the 8m Gemini-N telescope. The first spectrum was obtained during the 2013 December outburst. We used the Swift/UVOT observations of SNHunt 275, since 2008, to construct the bolometric light curve of the transient. The log of Swift-XRT observations, along with the source and background X-ray counts in the individual observations, is given in Table 5. (3 data files).

  16. Spectropolarimetry of the Type Ib Supernova iPTF 13bvn: Revealing the complex explosion geometry of a stripped-envelope core-collapse supernova

    CERN Document Server

    Reilly, Emma; Baade, Dietrich; Wheeler, J Craig; Silverman, Jeffrey M; Clocchiatti, Alejandro; Patat, Ferdinando; Höflich, Peter; Spyromilio, Jason; Wang, Lifan; Zelaya, Paula

    2015-01-01

    We present six epochs of spectropolarimetric observations and one epoch of spectroscopy of the Type Ib SN iPTF 13bvn. The epochs of these observations correspond to $-$10 to $+$61 days with respect to the {\\it r}-band light curve maximum. The continuum is intrinsically polarised to the $0.2-0.4\\%$ level throughout the observations, implying asphericities of $\\sim10\\%$ in the shape of the photosphere. We observe significant line polarisation associated with the spectral features of Ca II IR3, He I/Na I D, He I {\\lambda}{\\lambda}6678, 7065, Fe II {\\lambda}4924 and O I {\\lambda}7774. We propose that an absorption feature at $\\sim 6200\\mathrm{\\AA}$, usually identified as Si II $\\lambda 6355$, is most likely to be high velocity $\\mathrm{H\\alpha}$ at $-16,400$ $\\mathrm{km \\; s^{-1}}$. Two distinctly polarised components, separated in velocity, are detected for both He I/Na I D and Ca II IR3, indicating the presence of two discrete line forming regions in the ejecta in both radial velocity space and in the plane of ...

  17. Weekly Performance

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    There are many retired people living in Beijing. In order to amuse themselves and improve their health, some have formed yangko (folk dance) teams on a voluntary basis. Ordinarily they do the yangko individually and gather to perform on Sundays. Wearing traditional costumes and forming a circle, yangko teams’ members are enthusiastic about their activity, known as a "weekly performance."

  18. DISCOVERY, PROGENITOR AND EARLY EVOLUTION OF A STRIPPED ENVELOPE SUPERNOVA iPTF13bvn

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yi; Horesh, Assaf; Kulkarni, S. R. [Astronomy Department, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Kasliwal, Mansi M. [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Arcavi, Iair; Gal-Yam, Avishay; Gorbikov, Evgeny; Ofek, Eran O.; Yaron, Ofer [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Hancock, Paul [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Valenti, Stefano; Graham, Melissa; Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Sand, David [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States); Silverman, Jeffrey M.; Wheeler, J. Craig; Marion, G. H. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Walker, Emma S. [Department of Physics, Yale University, New Haven, CT 06511-8499 (United States); Mazzali, Paolo, E-mail: ycao@astro.caltech.edu [INAF-Padova Astronomical Observatory, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); and others

    2013-09-20

    The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue progenitor candidate in deep pre-explosion imaging within a 2σ error circle of 80 mas (8.7 pc). The candidate has an M{sub B} luminosity of –5.52 ± 0.39 mag and a B – I color of 0.25 ± 0.25 mag. If confirmed by future observations, this would be the first direct detection for a progenitor of a Type Ib. Fitting a power law to the early light curve, we find an extrapolated explosion date around 0.6 days before our first detection. We see no evidence of shock cooling. The pre-explosion detection limits constrain the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is also detected in centimeter and millimeter wavelengths. Fitting a synchrotron self-absorption model to our radio data, we find a mass-loading parameter of 1.3×10{sup 12} g cm{sup –1}. Assuming a wind velocity of 10{sup 3} km s{sup –1}, we derive a progenitor mass-loss rate of 3 × 10{sup –5} M {sub ☉} yr{sup –1}. Our observations, taken as a whole, are consistent with a Wolf-Rayet progenitor of the supernova iPTF13bvn.

  19. Simulation of herbicide degradation in different soils by use of Pedo-transfer functions (PTF) and non-linear kinetics.

    Science.gov (United States)

    von Götz, N; Richter, O

    1999-03-01

    The degradation behaviour of bentazone in 14 different soils was examined at constant temperature and moisture conditions. Two soils were examined at different temperatures. On the basis of these data the influence of soil properties and temperature on degradation was assessed and modelled. Pedo-transfer functions (PTF) in combination with a linear and a non-linear model were found suitable to describe the bentazone degradation in the laboratory as related to soil properties. The linear PTF can be combined with a rate related to the temperature to account for both soil property and temperature influence at the same time.

  20. Discovery, Progenitor & Early Evolution of a Stripped Envelope Supernova iPTF13bvn

    CERN Document Server

    Cao, Yi; Arcavi, Iair; Horesh, Assaf; Hancock, Paul; Valenti, Stefano; Cenko, S Bradley; Kulkarni, S R; Gal-Yam, Avishay; Gorbikov, Evgeny; Ofek, Eran O; Sand, David; Yaron, Ofer; Graham, Melissa; Silverman, Jeffrey M; Wheeler, J Craig; Marion, G H; Walker, Emma; Mazzali, Paolo; Howell, D Andrew; Bloom, Josh; Nugent, Peter E; Surace, Jason; Masci, Frank; Carpenter, John; Degenaar, Nathalie; Gelino, Christopher

    2013-01-01

    The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC5806 (22.5Mpc). Our spectral sequence in the optical and infrared suggests a likely Type Ib classification. We identify a single, blue progenitor candidate in deep pre-explosion imaging within a 2sigma error circle of 80 mas (8.7 pc). The candidate has a MB luminosity of -5.2+/-0.4 mag and a B-I color of 0.1+/-0.3 mag. If confirmed by future observations, this would be the first direct detection for a progenitor of a Type Ib. Fitting a power law to the early light curve, we find an extrapolated explosion date around 1.1 days before our first detection. We see no evidence of shock cooling. The pre-explosion detection limits constrain the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is also detected in cm and mm-wavelengths. Fitting a synchrotron self-absorption model to our radio data, we ?nd a mass loading parameter of 1.3*10^12 g/cm. Assuming a wind velocity o...

  1. A population of short-period variable quasars from PTF as supermassive black hole binary candidates

    Science.gov (United States)

    Charisi, M.; Bartos, I.; Haiman, Z.; Price-Whelan, A. M.; Graham, M. J.; Bellm, E. C.; Laher, R. R.; Márka, S.

    2016-12-01

    Supermassive black hole binaries (SMBHBs) at sub-parsec separations should be common in galactic nuclei, as a result of frequent galaxy mergers. Hydrodynamical simulations of circum-binary discs predict strong periodic modulation of the mass accretion rate on time-scales comparable to the orbital period of the binary. As a result, SMBHBs may be recognized by the periodic modulation of their brightness. We conducted a statistical search for periodic variability in a sample of 35 383 spectroscopically confirmed quasars in the photometric data base of the Palomar Transient Factory (PTF). We analysed Lomb-Scargle periodograms and assessed the significance of our findings by modelling each individual quasar's variability as a damped random walk (DRW). We identified 50 quasars with significant periodicity beyond the DRW model, typically with short periods of a few hundred days. We find 33 of these to remain significant after a re-analysis of their periodograms including additional optical data from the intermediate-PTF and the Catalina Real-Time Transient Survey. Assuming that the observed periods correspond to the redshifted orbital periods of SMBHBs, we conclude that our findings are consistent with a population of unequal-mass SMBHBs, with a typical mass ratio as low as q ≡ M2/M1 ≈ 0.01.

  2. Pulsational Pair-instability Model for Superluminous Supernova PTF12dam: Interaction and Radioactive Decay

    Science.gov (United States)

    Tolstov, Alexey; Nomoto, Ken’ichi; Blinnikov, Sergei; Sorokina, Elena; Quimby, Robert; Baklanov, Petr

    2017-02-01

    Being a superluminous supernova, PTF12dam can be explained by a 56Ni-powered model, a magnetar-powered model, or an interaction model. We propose that PTF12dam is a pulsational pair-instability supernova, where the outer envelope of a progenitor is ejected during the pulsations. Thus, it is powered by a double energy source: radioactive decay of 56Ni and a radiative shock in a dense circumstellar medium. To describe multicolor light curves and spectra, we use radiation-hydrodynamics calculations of the STELLA code. We found that light curves are well described in the model with 40 M⊙ ejecta and 20–40 M⊙ circumstellar medium. The ejected 56Ni mass is about 6 M⊙, which results from explosive nucleosynthesis with large explosion energy (2–3) × 1052 erg. In comparison with alternative scenarios of pair-instability supernova and magnetar-powered supernova, in the interaction model, all the observed main photometric characteristics are well reproduced: multicolor light curves, color temperatures, and photospheric velocities.

  3. The PTF Orion Project: a Possible Planet Transiting a T-Tauri Star

    CERN Document Server

    van Eyken, Julian C; von Braun, Kaspar; Kane, Stephen R; Plavchan, Peter; Bender, Chad F; Brown, Timothy M; Crepp, Justin; Fulton, Benjamin J; Howard, Andrew W; Howell, Steve B; Mahadevan, Suvrath; Marcy, Geoffrey W; Shporer, Avi; Szkody, Paula; Akeson, Rachel L; Beichman, Charles A; Boden, Andrew F; Gelino, Dawn M; Hoard, D W; Ramírez, Solange V; Rebull, Luisa M; Stauffer, John R; Bloom, Joshua S; Cenko, S Bradley; Kasliwal, Mansi M; Kulkarni, Shrinivas R; Law, Nicholas M; Nugent, Peter E; Ofek, Eran O; Poznanski, Dovi; Quimby, Robert M; Walters, Richard; Grillmair, Carl J; Laher, Russ; Levitan, David B; Sesar, Branimir; Surace, Jason A

    2012-01-01

    We report observations of a possible young transiting planet orbiting a previously known weak-lined T-Tauri star in the 7-10Myr-old Orion-OB1a/25-Ori region. The candidate was found as part of the Palomar Transient Factory (PTF) Orion project. It has a photometric transit period of 0.448413 \\pm 0.000040 days, and appears in both 2009 and 2010 PTF data. Follow-up low-precision radial velocity observations and adaptive-optics imaging suggest that the star is not an eclipsing binary, and that it is unlikely that a background source is blended with the target and mimicking the observed transit. Radial-velocity observations with the Hobby-Eberly and Keck telescopes yield a radial velocity that has the same period as the photometric event, but is offset in phase from the transit center by \\approx -0.22 periods. The amplitude (half range) of the radial velocity variations is 2.4 km/s and is comparable with the expected radial velocity amplitude that stellar spots could induce. The radial velocity curve is likely dom...

  4. VizieR Online Data Catalog: Imaging observations of iPTF 13ajg (Vreeswijk+, 2014)

    Science.gov (United States)

    Vreeswijk, P. M.; Savaglio, S.; Gal-Yam, A.; De Cia, A.; Quimby, R. M.; Sullivan, M.; Cenko, S. B.; Perley, D. A.; Filippenko, A. V.; Clubb, K. I.; Taddia, F.; Sollerman, J.; Leloudas, G.; Arcavi, I.; Rubin, A.; Kasliwal, M. M.; Cao, Y.; Yaron, O.; Tal, D.; Ofek, E. O.; Capone, J.; Kutyrev, A. S.; Toy, V.; Nugent, P. E.; Laher, R.; Surace, J.; Kulkarni, S. R.

    2017-08-01

    iPTF 13ajg was imaged with the Palomar 48 inch (P48) Oschin iPTF survey telescope equipped with a 12kx8k CCD mosaic camera (Rahmer et al. 2008SPIE.7014E..4YR) in the Mould R filter, the Palomar 60 inch and CCD camera (Cenko et al. 2006PASP..118.1396C) in Johnson B and Sloan Digital Sky Survey (SDSS) gri, the 2.56 m Nordic Optical Telescope (on La Palma, Canary Islands) with the Andalucia Faint Object Spectrograph and Camera (ALFOSC) in SDSS ugriz, the 4.3 m Discovery Channel Telescope (at Lowell Observatory, Arizona) with the Large Monolithic Imager (LMI) in SDSS r, and with LRIS (Oke et al. 1995PASP..107..375O) and the Multi-Object Spectrometer for Infrared Exploration (MOSFIRE; McLean et al. 2012SPIE.8446E..0JM), both mounted on the 10 m Keck-I telescope (on Mauna Kea, Hawaii), in g and Rs with LRIS and J and Ks with MOSFIRE. (1 data file).

  5. Rbms3, an RNA-binding protein, mediates the expression of Ptf1a by binding to its 3'UTR during mouse pancreas development.

    Science.gov (United States)

    Lu, Chung-Kuang; Lai, Yi-Chyi; Chen, Hau-Ren; Chiang, Ming-Ko

    2012-07-01

    The development of the pancreas is a complicated process that is regulated on several levels. Pancreas transcription factor 1, alpha subunit (Ptf1a), also known as p48, is a pancreas-specific basic helix-loop-helix transcription factor that is critical for both exocrine pancreas development and maintenance of acinar cell differentiation. Based on a differential screening assay, we identified Rbms3, a gene encoding a glycine-rich RNA-binding protein, to be specifically expressed in the neural tube and the pancreatic rudiment of e10.5 embryos. The presence of Rbms3 in the early developing pancreas suggests that specific post-transcriptional regulation mechanisms play an important role in controlling pancreas development. In this study, we show that Rbms3 binds to the 3'UTR of Ptf1a mRNA, but not the 3'UTR of Pdx1, which is another pancreatic transcription factor. The ectopic expression of Rbms3 stimulates the translation of a reporter gene carrying the Ptf1a 3'UTR. In addition, when Rbms3 expression is suppressed in the AR42J-B13 pancreatic exocrine cell line, the expression of Ptf1a is also down-regulated. These results suggest that binding of Rbms3 to the 3'UTR of Ptf1a regulates the production of the Ptf1a protein and, thereby, indirectly regulates the expression of the Ptf1a downstream target genes.

  6. A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates

    CERN Document Server

    Charisi, M; Haiman, Z; Price-Whelan, A M; Graham, M J; Bellm, E C; Laher, R R; Marka, S

    2016-01-01

    Supermassive black hole binaries (SMBHBs) at sub-parsec separations should be common in galactic nuclei, as a result of frequent galaxy mergers. Hydrodynamical simulations of circumbinary discs predict strong periodic modulation of the mass accretion rate on time-scales comparable to the orbital period of the binary. As a result, SMBHBs may be recognized by the periodic modulation of their brightness. We conducted a statistical search for periodic variability in a sample of 35,383 spectroscopically confirmed quasars in the photometric database of the Palomar Transient Factory (PTF). We analysed Lomb-Scargle periodograms and assessed the significance of our findings by modeling each individual quasar's variability as a damped random walk (DRW). We identified 50 quasars with significant periodicity beyond the DRW model, typically with short periods of a few hundred days. We find 33 of these to remain significant after a re-analysis of their periodograms including additional optical data from the intermediate-PT...

  7. PTF discovers and follows-up nearby, young, Type II supernova

    Science.gov (United States)

    Kasliwal, M. M.; Quimby, R. M.; Ofek, E. O.; Kulkarni, S. R.; Gal-Yam, A.; Arcavi, I.; Green, Y.; Walker, E.; Mazzali, P.; Nugent, P. E.; Poznanski, D.; Howell, D. A.; Dilday, B.; Fox, D. B.

    2010-09-01

    On UT 2010 Sep 15.243, the Palomar Transient Factory discovered an optical transient, PTF10vdl at RA(J2000) = 23:05:49.001 and DEC(J2000)=03:31:20.50 near NGC 7483. We obtained Target Of Opportunity spectra with Gemini-S/GMOS (PI Kasliwal) on Sep 16.29. The spectrum was extremely blue (f_nu proportional to nu^4.5) and nearly featureless. We further obtained a spectrum with the TNG/DOLORES (PI Walker) on Sep 17.40 and P-Cygni profiles of four Balmer lines were clearly visible, consistent with the redshift of NGC 7483, suggesting this is a Type II supernova.

  8. VLA and Swift XRT Observations of PTF12os in NGC 5806

    Science.gov (United States)

    Stockdale, C. J.; Immler, S.; Horesh, A.; Kasliwal, M.; Ryder, S. D.; Weiler, K. W.; Van Dyk, S. D.; Panagia, N.; Bauer, F. E.; Marcaide, J. M.; Pooley, D.; Sramek, R. A.; Williams, C. L.

    2012-01-01

    We report the detection of radio emission near the position of the type-IIb supernova PTF2012os (ATEL #3881) with the Karl G. Jansky Very Large Array radio telescope in the DnC configuration: A flux density of 0.44 ± 0.05 mJy was measured at 5.02 GHz (wavelength 6.0 cm) on 2012 Jan. 22.42 UT. The measured position of the radio emission of R.A. = 14h59m59.s12, Decl. = +01d53m23s.3, equinox 2000.0 is in good agreement with the measured optical position of (ending digits) R.A.

  9. PTF11agg AS THE FIRST EVIDENCE FOR REVERSE SHOCK EMISSION FROM A POST-MERGER MILLISECOND MAGNETAR

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lingjun; Dai Zigao, E-mail: dzg@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing (China)

    2013-09-10

    Based on the stiff equations of state of neutron stars (NS) and the discovery of high-mass NSs, it is highly probable that a NS-NS merger will result in a rapidly rotating massive magnetar. The central magnetar will dissipate its rotational energy to the outflow by injecting Poynting flux, which will become lepton-dominated so that a long-lasting reverse shock (RS) develops. We calculate the emission of the RS as well as the emission of forward shock (FS) and find that, in most cases, the RS emission is stronger than FS emission. It is found that the recently discovered transient, PTF11agg, can be neatly accounted for by the RS emission powered by a millisecond magnetar. Other alternative models have been considered and cannot explain the observed light curves well. We therefore suggest that PTF11agg is the first evidence for RS emission from a post-merger millisecond magnetar.

  10. The hydrogen-poor superluminous supernova iPTF13ajg and its host galaxy in absorption and emission

    CERN Document Server

    Vreeswijk, Paul M; Gal-Yam, Avishay; De Cia, Annalisa; Quimby, Robert M; Sullivan, Mark; Cenko, S Bradley; Perley, Daniel A; Filippenko, Alexei V; Clubb, Kelsey I; Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos; Arcavi, Iair; Rubin, Adam; Kasliwal, Mansi M; Cao, Yi; Yaron, Ofer; Tal, David; Ofek, Eran O; Capone, John; Kutyrev, Alexander S; Toy, Vicki; Nugent, Peter E; Laher, Russ; Surace, Jason; Kulkarni, Shrinivas R

    2014-01-01

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory: iPTF13ajg. At a redshift of z=0.7403, derived from narrow absorption lines, iPTF13ajg peaked at an absolute magnitude M(u,AB)=-22.5, one of the most luminous supernovae to date. The uBgRiz light curves, obtained with the P48, P60, NOT, DCT, and Keck telescopes, and the nine-epoch spectral sequence secured with the Keck and the VLT (covering 3 rest-frame months), are tied together photometrically to provide an estimate of the flux evolution as a function of time and wavelength. The observed bolometric peak luminosity of iPTF13ajg is 3.2x10^44 erg/s, while the estimated total radiated energy is 1.3x10^51 erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the VLT. From Voigt-profile fitting, we derive the column densities log N(Mg I)=11.94+-0.06, log ...

  11. PTF1 J071912.13+485834.0: An outbursting AM CVn system discovered by a synoptic survey

    CERN Document Server

    Levitan, David; Groot, Paul J; Kulkarni, Shrinivas R; Ofek, Eran O; Prince, Thomas A; Shporer, Avi; Bloom, Joshua S; Cenko, S Bradley; Kasliwal, Mansi M; Law, Nicholas M; Nugent, Peter E; Poznanski, Dovi; Quimby, Robert M; Horesh, Assaf; Sesar, Branimir; Sternberg, Assaf

    2011-01-01

    We present extensive photometric and spectroscopic observations of PTF1 J071912.13+485834.0, an outbursting AM CVn system discovered by the Palomar Transient Factory (PTF). AM CVn systems are stellar binaries with some of the smallest separations known and orbital periods ranging from 5 to 65 minutes. They are believed to be composed of a white dwarf accretor and a (semi)-degenerate He-rich donor and are considered to be the helium equivalents of Cataclysmic Variables. We have spectroscopically and photometrically identified an orbital period of 26.77 \\pm 0.02 minutes for PTF1 J071912.13+485834.0 and found a super-outburst recurrence time of greater than 65 days along with the presence of "normal" outbursts - rarely seen in AM CVn systems but well known in super-outbursting Cataclysmic Variables. We present a long-term light curve over two super-cycles as well as high cadence photometry of both outburst and quiescent stages, both of which show clear variability. We also compare both the outburst and quiescent...

  12. Discovery and redshift of an optical afterglow in 71 square degrees iPTF13bxl and GRB 130702A

    CERN Document Server

    Singer, Leo P; Kasliwal, Mansi M; Perley, Daniel A; Ofek, Eran O; Brown, Duncan A; Nugent, Peter E; Kulkarni, S R; Corsi, Alessandra; Frail, Dale A; Bellm, Eric; Mulchaey, John; Arcavi, Iair; Barlow, Tom; Bloom, Joshua S; Cao, Yi; Gehrels, Neil; Horesh, Assaf; Masci, Frank J; McEnery, Julie; Rau, Arne; Surace, Jason A; Yaron, Ofer

    2013-01-01

    We report the discovery of the optical afterglow of the gamma-ray burst (GRB) 130702A, identified upon searching 71 square degrees surrounding the Fermi Gamma-ray Burst Monitor (GBM) localization. Discovered and characterized by the intermediate Palomar Transient Factory (iPTF), iPTF13bxl is the first afterglow discovered solely based on a GBM localization. Real-time image subtraction, machine learning, human vetting, and rapid response multi-wavelength follow-up enabled us to quickly narrow a list of 27,004 optical transient candidates to a single afterglow-like source. Detection of a new, fading X-ray source by Swift and a radio counterpart by CARMA and the VLA confirmed the association between iPTF13bxl and GRB 130702A. Spectroscopy with the Magellan and Palomar 200-inch telescopes showed the afterglow to be at a redshift of z=0.145, placing GRB 130702A among the lowest redshift GRBs detected to date. The prompt gamma-ray energy release and afterglow luminosity are intermediate between typical cosmological...

  13. The hydrogen-poor superluminous supernova iPTF 13ajg and its host galaxy in absorption and emission

    Energy Technology Data Exchange (ETDEWEB)

    Vreeswijk, Paul M.; Gal-Yam, Avishay; De Cia, Annalisa; Rubin, Adam; Yaron, Ofer; Tal, David; Ofek, Eran O. [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Savaglio, Sandra [Max Planck Institute for Extraterrestrial Physics, D-85748 Garching bei München (Germany); Quimby, Robert M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Cenko, S. Bradley; Filippenko, Alexei V.; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Perley, Daniel A.; Cao, Yi [Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos [Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova 10691 Stockholm (Sweden); Arcavi, Iair [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Kasliwal, Mansi M., E-mail: paul.vreeswijk@weizmann.ac.il [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2014-12-10

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M {sub u,} {sub AB} = –22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 10{sup 44} erg s{sup –1}, while the estimated total radiated energy is 1.3 × 10{sup 51} erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s{sup –1}, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR{sub [O} {sub II]}<0.07M{sub ⊙}yr{sup −1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g {sub AB} ≈ 27.0 and R {sub AB} ≥ 26.0 mag, corresponding to M {sub B,} {sub Vega} ≳ –17.7 mag.

  14. iPTF Search for an Optical Counterpart to Gravitational Wave Trigger GW150914

    CERN Document Server

    Kasliwal, M M; Singer, L P; Corsi, A; Cao, Y; Barlow, T; Bhalerao, V; Bellm, E; Cook, D; Duggan, G E; Ferretti, R; Frail, D A; Horesh, A; Kendrick, R; Kulkarni, S R; Lunnan, R; Palliyaguru, N; Laher, R; Masci, F; Manulis, I; Miller, A A; Nugent, P E; Perley, D; Prince, T A; Rana, J; Rebbapragada, U; Sesar, B; Singhal, A; Surace, J; Van Sistine, A

    2016-01-01

    The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the Northern night sky, due both to sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 135 sq. deg., after extensive filtering, 8 candidates were deemed worthy of additional follow-up. Within two hours, all 8 were spectroscopically classified by the Keck II telescope. Curiously, even though such events are rare, one of our candidates was a superluminous supernova. We obtained radio data with the Very Large Array and X-ray follow-up with the Swift satellite for this transient. None of our candidates appear to be associated with the gravitational wave trigger, which is unsurprising given that GW...

  15. PTF10iya: A short-lived, luminous flare from the nuclear region of a star-forming galaxy

    CERN Document Server

    Cenko, S Bradley; Kulkarni, S R; Strubbe, Linda E; Miller, Adam A; Butler, Nathaniel R; Quimby, Robert M; Gal-Yam, Avishay; Ofek, Eran O; Quataert, Eliot; Bildsten, Lars; Poznanski, Dovi; Perley, Daniel A; Morgan, Adam N; Filippenko, Alexei V; Arcavi, Iair; Ben-Ami, Sagi; Cucchiara, Antonio; Fassnacht, Christopher D; Green, Yoav; Hook, Isobel M; Howell, D Andrew; Lagattuta, David J; Law, Nicholas M; Kasliwal, Mansi M; Nugent, Peter E; Silverman, Jeffrey M; Sullivan, Mark; Tendulkar, Shriharsh P; Yaron, Ofer

    2011-01-01

    We present the discovery and characterisation of PTF10iya, a short-lived (dt ~ 10 d, with an optical decay rate of ~ 0.3 mag per d), luminous (M_g ~ -21 mag) transient source found by the Palomar Transient Factory. The ultraviolet/optical spectral energy distribution is reasonably well fit by a blackbody with T ~ 1-2 x 10^4 K and peak bolometric luminosity L_BB ~ 10^44 -10^45 erg per s (depending on the details of the extinction correction). A comparable amount of energy is radiated in the X-ray band that appears to result from a distinct physical process. The location of PTF10iya is consistent with the nucleus of a star-forming galaxy (z = 0.22405 +/- 0.00006) to within 350 mas (99.7 per cent confidence radius), or a projected distance of less than 1.2 kpc. At first glance, these properties appear reminiscent of the characteristic "big blue bump" seen in the near-ultraviolet spectra of many active galactic nuclei (AGNs). However, emission-line diagnostics of the host galaxy, along with a historical light cur...

  16. The Rise of SN 2014J in the Nearby Galaxy M 82

    Science.gov (United States)

    A.Goobar; Johansson, J.; Amanullah, R.; Cao, Y.; Perley, D.A.; Kasliwal, M. M.; Ferreti, R.; Nugent, P. E.; Harris, C.; Cenko, S. B.

    2014-01-01

    We report on the discovery of SN 2014J in the nearby galaxy M 82. Given its proximity, it offers the best opportunity to date to study a thermonuclear supernova over a wide range of the electromagnetic spectrum. Optical, near-IR and mid-IR observations on the rising lightcurve, orchestrated by the intermediate Palomar Transient Factory (iPTF), show that SN 2014J is a spectroscopically normal Type Ia supernova, albeit exhibiting high-velocity features in its spectrum and heavily reddened by dust in the host galaxy. Our earliest detections start just hours after the fitted time of explosion. We use high-resolution optical spectroscopy to analyze the dense intervening material and do not detect any evolution in the resolved absorption features during the lightcurve rise. Similarly to other highly reddened Type Ia supernovae, a low value of total-to-selective extinction, R (sub V) less than or approximately equal to 2, provides the best match to our observations. We also study pre-explosion optical and near-IR images from HST with special emphasis on the sources nearest to the SN location.

  17. LRH-1 and PTF1-L coregulate an exocrine pancreas-specific transcriptional network for digestive function.

    Science.gov (United States)

    Holmstrom, Sam R; Deering, Tye; Swift, Galvin H; Poelwijk, Frank J; Mangelsdorf, David J; Kliewer, Steven A; MacDonald, Raymond J

    2011-08-15

    We have determined the cistrome and transcriptome for the nuclear receptor liver receptor homolog-1 (LRH-1) in exocrine pancreas. Chromatin immunoprecipitation (ChIP)-seq and RNA-seq analyses reveal that LRH-1 directly induces expression of genes encoding digestive enzymes and secretory and mitochondrial proteins. LRH-1 cooperates with the pancreas transcription factor 1-L complex (PTF1-L) in regulating exocrine pancreas-specific gene expression. Elimination of LRH-1 in adult mice reduced the concentration of several lipases and proteases in pancreatic fluid and impaired pancreatic fluid secretion in response to cholecystokinin. Thus, LRH-1 is a key regulator of the exocrine pancreas-specific transcriptional network required for the production and secretion of pancreatic fluid.

  18. PTF1 J191905.19+481506.2 - A Partially Eclipsing AM CVn System Discovered in the Palomar Transient Factory

    CERN Document Server

    Levitan, David; Groot, Paul J; Margon, Bruce; Prince, Thomas A; Kulkarni, Shrinivas R; Hallinan, Gregg; Harding, Leon K; Kyne, Gillian; Laher, Russ; Ofek, Eran O; Rutten, René G M; Sesar, Branimir; Surace, Jason

    2014-01-01

    We report on PTF1 J191905.19+481506.2, a newly discovered, partially eclipsing, outbursting AM CVn system found in the Palomar Transient Factory synoptic survey. This is only the second known eclipsing AM CVn system. We use high-speed photometric observations and phase-resolved spectroscopy to establish an orbital period of 22.4559(3) min. We also present a long-term light curve and report on the normal and super-outbursts regularly seen in this system, including a super-outburst recurrence time of 36.8(4) d. We use the presence of the eclipse to place upper and lower limits on the inclination of the system and discuss the number of known eclipsing AM CVn systems versus what would be expected.

  19. The Red Supergiant Progenitor of Supernova 2012aw (PTF12bvh) in Messier 95

    CERN Document Server

    Van Dyk, Schuyler D; Poznanski, Dovi; Arcavi, Iair; Gal-Yam, Avishay; Filippenko, Alexei V; Silverio, Kathryn; Stockton, Alan; Cuillandre, Jean-Charles; Marcy, Geoffrey W; Howard, Andrew W; Isaacson, Howard

    2012-01-01

    We report on the direct detection and characterization of the probable red supergiant progenitor of the intermediate-luminosity Type II-Plateau (II-P) supernova (SN) 2012aw in the nearby (10.0 Mpc) spiral galaxy Messier 95 (M95; NGC 3351). We have identified the star in both Hubble Space Telescope images of the host galaxy, obtained 17-18 yr prior to the explosion, and near-infrared ground-based images, obtained 6-12 yr prior to the SN. The luminous supergiant showed evidence for substantial circumstellar dust, manifested as excess line-of-sight extinction. The effective total-to-selective ratio of extinction to the star was R'_V \\approx 4.35, which is significantly different from that of diffuse interstellar dust (i.e., R_V=3.1), and the total extinction to the star was therefore, on average, A_V \\approx 3.1 mag. We find that the observed spectral energy distribution for the progenitor star is consistent with an effective temperature of 3600 K (spectral type M3), and that the star therefore had a bolometric ...

  20. SN 2002cx The Most Peculiar Known Type Ia Supernova

    CERN Document Server

    Li, W; Chornock, R; Berger, E; Berlind, P; Calkins, M L; Challis, P M; Fassnacht, C D; Jha, S; Kirshner, R P; Matheson, T; Sargent, W L W; Simcoe, R A; Smith, G H; Squires, G; Li, Weidong; Filippenko, Alexei V.; Chornock, Ryan; Berger, Edo; Berlind, Perry; Calkins, Michael L.; Challis, Peter; Fassnacht, Chris; Jha, Saurabh; Kirshner, Robert P.; Matheson, Thomas; Sargent, Wallace L. W.; Simcoe, Robert A.; Smith, Graeme H.; Squires, Gordon

    2003-01-01

    We present photometric and spectroscopic observations of supernova (SN) 2002cx, which reveal it to be unique among all observed type Ia supernovae (SNe Ia). SN 2002cx exhibits a SN 1991T-like premaximum spectrum, a SN 1991bg-like luminosity, and expansion velocities roughly half those of normal SNe Ia. Photometrically, SN 2002cx has a broad peak in the $R$ band and a plateau phase in the $I$ band, and slow late-time decline. The $(B - V)$ color evolution is nearly normal, but the $(V - R)$ and $(V - I)$ colors are very red. Early-time spectra of SN 2002cx evolve very quickly and are dominated by lines from Fe-group elements; features from intermediate-mass elements (Ca, S, Si) are weak or absent. Mysterious emission lines are observed around 7000 \\AA\\ at about 3 weeks after maximum brightness. The nebular spectrum of SN 2002cx is also unique, consisting of narrow iron and cobalt lines. The observations of SN 2002cx are inconsistent with the observed spectral/photometric sequence, and provide a major challenge...

  1. ptf1a+, ela3l− cells are developmentally maintained progenitors for exocrine regeneration following extreme loss of acinar cells in zebrafish larvae

    Science.gov (United States)

    Schmitner, Nicole; Kohno, Kenji

    2017-01-01

    ABSTRACT The exocrine pancreas displays a significant capacity for regeneration and renewal. In humans and mammalian model systems, the partial loss of exocrine tissue, such as after acute pancreatitis or partial pancreatectomy induces rapid recovery via expansion of surviving acinar cells. In mouse it was further found that an almost complete removal of acinar cells initiates regeneration from a currently not well-defined progenitor pool. Here, we used the zebrafish as an alternative model to study cellular mechanisms of exocrine regeneration following an almost complete removal of acinar cells. We introduced and validated two novel transgenic approaches for genetically encoded conditional cell ablation in the zebrafish, either by caspase-8-induced apoptosis or by rendering cells sensitive to diphtheria toxin. By using the ela3l promoter for exocrine-specific expression, we show that both approaches allowed cell-type-specific removal of >95% of acinar tissue in larval and adult zebrafish without causing any signs of unspecific side effects. We find that zebrafish larvae are able to recover from a virtually complete acinar tissue ablation within 2 weeks. Using short-term lineage-tracing experiments and EdU incorporation assays, we exclude duct-associated Notch-responsive cells as the source of regeneration. Rather, a rare population of slowly dividing ela3l-negative cells expressing ptf1a and CPA was identified as the origin of the newly forming exocrine cells. Cells are actively maintained, as revealed by a constant number of these cells at different larval stages and after repeated cell ablation. These cells establish ela3l expression about 4-6 days after ablation without signs of increased proliferation in between. With onset of ela3l expression, cells initiate rapid proliferation, leading to fast expansion of the ela3l-positive population. Finally, we show that this proliferation is blocked by overexpression of the Wnt-signaling antagonist dkk1b. In

  2. SN1987A's Twentieth Anniversary

    Science.gov (United States)

    2007-02-01

    provided further evidence for asymmetries in the explosion. The 'Bochum event' was a rapid change in the line profile observed with the Bochum telescope on La Silla. It is the signature of a radioactive blob rising from the inner ejecta to the surface. "The picture emerging from the observations of the first several weeks was certainly more complex than what had ever been assumed of supernovae before," says Bruno Leibundgut (ESO). ESO PR Photo 08f/07 ESO PR Photo 08f/07 A Ring Around SN1987A The 1-m telescope at La Silla was also extensively used in daytime observing the supernova in the near- and mid-infrared for more than one year after the explosion. A clear excess emission developed in the near-infrared already 10 days after the explosion, the origin of which is still not fully understood. It was most probably due to circumstellar material that was lighted up by the explosion. Dust condensation in the ejecta was discovered by spectroscopy about 500 days after the explosion. Macroscopic dust grains partially covered the ejecta, and most probably still do. They might explain why no compact object is seen at the location of the supernova. In 1989, when the NTT came into operation, it imaged for the first time the circumstellar ring around SN 1987A. And, about three years after the explosion, NTT images revealed a circumstellar structure around SN 1987A which resembled the triangular hat which Napoleon wore. Napoleon's hat gave the first opportunity for a 3-dimensional view of SN 1987A. "The existence of the ring presents an unsolved puzzle for SN 1987A," says Roberto Gilmozzi (ESO). "Even though it is not clear how to construct such a ring, it is likely that the star that exploded as SN 1987A had a companion." When ESO's Very Large Telescope came into operation, the interest in the supernova had not faded away. Far from it! Observations were done with the VLT's many instruments, including FORS, UVES, ISAAC, and VISIR, to probe in more detail the surroundings of the

  3. VizieR Online Data Catalog: Photometry of supernova iPTF13z (Nyholm+, 2017)

    Science.gov (United States)

    Nyholm, A.; Sollerman, J.; Taddia, F.; Fremling, C.; Moriya, T. J.; Ofek, E. O.; Gal-Yam, A.; De Cia, A.; Roy, R.; Kasliwal, M. M.; Cao, Y.; Nugent, P. E.; Masci, F. J.

    2017-06-01

    The 1.2m Samuel Oschin telescope (also called P48) was equipped with the CFH12K (12Kx8K pixel) CCD camera and a Mould R filter. The 1.52m telescope (also called P60) was equipped with a 2048x2048 pixel CCD camera and Sloan Digital Sky Survey (SDSS) gri and Johnson B filters. We present AB magnitudes from PSF photometry (relative photometry based on SDSS) on host subtracted images. The magnitudes are given along with their statistical errors (1 sigma). The photometry was done using the FPipe pipeline (2016A&A...593A..68F). The times of the measurements are given both as MJD and relative to time of SN discovery (JD 2456324.98). For the dates given in Table 3, measurements made within 1 day are considered to be simultaneous. The observations were made during 2013 Feb - 2016 Jan. (2 data files).

  4. DISCOVERY AND REDSHIFT OF AN OPTICAL AFTERGLOW IN 71 deg{sup 2}: iPTF13bxl AND GRB 130702A

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Leo P.; Brown, Duncan A. [LIGO Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Bradley Cenko, S.; Gehrels, Neil; McEnery, Julie [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kasliwal, Mansi M.; Mulchaey, John [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Perley, Daniel A.; Kulkarni, S. R.; Bellm, Eric; Barlow, Tom; Cao, Yi; Horesh, Assaf [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Ofek, Eran O.; Arcavi, Iair [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Nugent, Peter E.; Bloom, Joshua S. [Department of Astronomy, University of California Berkeley, B-20 Hearst Field Annex 3411, Berkeley, CA 94720-3411 (United States); Corsi, Alessandra [George Washington University, Corcoran Hall, Washington, DC 20052 (United States); Frail, Dale A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Masci, Frank J., E-mail: lsinger@caltech.edu [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); and others

    2013-10-20

    We report the discovery of the optical afterglow of the γ-ray burst (GRB) 130702A, identified upon searching 71 deg{sup 2} surrounding the Fermi Gamma-ray Burst Monitor (GBM) localization. Discovered and characterized by the intermediate Palomar Transient Factory, iPTF13bxl is the first afterglow discovered solely based on a GBM localization. Real-time image subtraction, machine learning, human vetting, and rapid response multi-wavelength follow-up enabled us to quickly narrow a list of 27,004 optical transient candidates to a single afterglow-like source. Detection of a new, fading X-ray source by Swift and a radio counterpart by CARMA and the Very Large Array confirmed the association between iPTF13bxl and GRB 130702A. Spectroscopy with the Magellan and Palomar 200 inch telescopes showed the afterglow to be at a redshift of z = 0.145, placing GRB 130702A among the lowest redshift GRBs detected to date. The prompt γ-ray energy release and afterglow luminosity are intermediate between typical cosmological GRBs and nearby sub-luminous events such as GRB 980425 and GRB 060218. The bright afterglow and emerging supernova offer an opportunity for extensive panchromatic follow-up. Our discovery of iPTF13bxl demonstrates the first observational proof-of-principle for ∼10 Fermi-iPTF localizations annually. Furthermore, it represents an important step toward overcoming the challenges inherent in uncovering faint optical counterparts to comparably localized gravitational wave events in the Advanced LIGO and Virgo era.

  5. SN 2005ap: A Most Brilliant Explosion

    CERN Document Server

    Quimby, Robert M; Wheeler, J Craig; Höflich, Peter; Akerlof, Carl W; Rykoff, Eli S

    2007-01-01

    We present unfiltered photometric observations with ROTSE-III and optical spectroscopic follow-up with the HET and Keck of the most luminous supernova yet identified, SN 2005ap. The spectra taken about 3 days before and 6 days after maximum light show narrow emission lines (likely originating in the dwarf host) and absorption lines at a redshift of z=0.2832, which puts the peak unfiltered magnitude at -22.7 +/- 0.1 absolute. Broad P-Cygni features corresponding to H-alpha, CIII, NIII, and OIII, are further detected with a photospheric velocity of ~20,000 km/s. Unlike other highly luminous supernovae such as 2006gy and 2006tf that show slow photometric evolution, the light curve of SN 2005ap indicates a 1-3 week rise to peak followed by a relatively rapid decay. The spectra also lack the distinct emission peaks from moderately broadened (FWHM ~ 2,000 km/s) Balmer lines seen in SN 2006gy and SN 2006tf. We briefly discuss the origin of the extraordinary luminosity from a strong interaction as may be expected fro...

  6. SN 2010jl: Optical to hard X-ray observations reveal an explosion embedded in a ten solar mass cocoon

    Energy Technology Data Exchange (ETDEWEB)

    Ofek, Eran O.; Gal-Yam, Avishay; Arcavi, Iair [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Zoglauer, Andreas; Boggs, Steven E.; Barriére, Nicolas M. [Space Sciences Laboratory, Department of Physics, University of California, 7 Gauss Way, Berkeley, CA 94720 (United States); Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Fryer, Chris L.; Even, Wesley [CCS Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Harrison, Fiona A.; Kulkarni, Shrinivas R.; Bellm, Eric; Grefenstette, Brian [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Cenko, S. Bradley; Bloom, Joshua S.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Christensen, Finn [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Craig, William W.; Hailey, Charles J. [Columbia Astrophysics Laboratory, 538 West 120th Street, New York, NY 10027 (United States); Laher, Russ [Spitzer Science Center, MS 314-6, California Institute of Technology, Pasadena, CA 91125 (United States); and others

    2014-01-20

    Some supernovae (SNe) may be powered by the interaction of the SN ejecta with a large amount of circumstellar matter (CSM). However, quantitative estimates of the CSM mass around such SNe are missing when the CSM material is optically thick. Specifically, current estimators are sensitive to uncertainties regarding the CSM density profile and the ejecta velocity. Here we outline a method to measure the mass of the optically thick CSM around such SNe. We present new visible-light and X-ray observations of SN 2010jl (PTF 10aaxf), including the first detection of an SN in the hard X-ray band using NuSTAR. The total radiated luminosity of SN 2010jl is extreme—at least 9 × 10{sup 50} erg. By modeling the visible-light data, we robustly show that the mass of the circumstellar material within ∼10{sup 16} cm of the progenitor of SN 2010jl was in excess of 10 M {sub ☉}. This mass was likely ejected tens of years prior to the SN explosion. Our modeling suggests that the shock velocity during shock breakout was ∼6000 km s{sup –1}, decelerating to ∼2600 km s{sup –1} about 2 yr after maximum light. Furthermore, our late-time NuSTAR and XMM spectra of the SN presumably provide the first direct measurement of SN shock velocity 2 yr after the SN maximum light—measured to be in the range of 2000-4500 km s{sup –1} if the ions and electrons are in equilibrium, and ≳ 2000 km s{sup –1} if they are not in equilibrium. This measurement is in agreement with the shock velocity predicted by our modeling of the visible-light data. Our observations also show that the average radial density distribution of the CSM roughly follows an r {sup –2} law. A possible explanation for the ≳ 10 M {sub ☉} of CSM and the wind-like profile is that they are the result of multiple pulsational pair instability events prior to the SN explosion, separated from each other by years.

  7. The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube.

    Science.gov (United States)

    Hanotel, Julie; Bessodes, Nathalie; Thélie, Aurore; Hedderich, Marie; Parain, Karine; Van Driessche, Benoit; Brandão, Karina De Oliveira; Kricha, Sadia; Jorgensen, Mette C; Grapin-Botton, Anne; Serup, Palle; Van Lint, Carine; Perron, Muriel; Pieler, Tomas; Henningfeld, Kristine A; Bellefroid, Eric J

    2014-02-15

    The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing genes encoding putative chromatin-remodeling zinc finger transcription factors in Xenopus embryos, we identified Prdm13 as a histone methyltransferase belonging to the Ptf1a synexpression group. Gain and loss of Ptf1a function analyses in both frog and mice indicates that Prdm13 is positively regulated by Ptf1a and likely constitutes a direct transcriptional target. We also showed that this regulation requires the formation of the Ptf1a-Rbp-j complex. Prdm13 knockdown in Xenopus embryos and in Ptf1a overexpressing ectodermal explants lead to an upregulation of Tlx3/Hox11L2, which specifies a glutamatergic lineage and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube.

  8. A Wolf-Rayet-like progenitor of supernova SN 2013cu from spectral observations of a wind

    CERN Document Server

    Gal-Yam, Avishay; Ofek, E O; Ben-Ami, S; Cenko, S B; Kasliwal, M M; Cao, Y; Yaron, O; Tal, D; Silverman, J M; Horesh, A; De Cia, A; Taddia, F; Sollerman, J; Perley, D; Vreeswijk, P M; Kulkarni, S R; Nugent, P E; Filippenko, A V; Wheeler, J C

    2014-01-01

    The explosive fate of massive stripped Wolf-Rayet (W-R) stars is a key open question in stellar physics. An appealing option is that hydrogen-deficient W-R stars are the progenitors of some H-poor supernova (SN) explosions of Types IIb, Ib, and Ic. A blue object, having luminosity and colors consistent with those of some W-R stars, has been recently identified at the location of a SN~Ib in pre-explosion images but has not yet been conclusively determined to have been the progenitor. Similar previous works have so far only resulted in nondetections. Comparison of early photometric observations of Type Ic supernovae with theoretical models suggests that the progenitor stars had radii <10^12 cm, as expected for some W-R stars. However, the hallmark signature of W-R stars, their emission-line spectra, cannot be probed by such studies. Here, we report the detection of strong emission lines in an early-time spectrum of SN 2013cu (iPTF13ast; Type IIb) obtained ~15.5 hr after explosion ("flash spectroscopy"). We i...

  9. Golden Week, Golden Effect

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The Golden Week Holiday System was established in 1999. Bv adding legal holidays and the time off from the previous and following weekends, China made three Golden Weeks (7-day holidays), for the Spring Festival, May Labor Day and National Day in October.Since it was introduced eight years ago,the Golden Weeks have added considerably to China's economic development.The significant role they have played in promoting economic development and changing the Chinese people's concept of consumption and way of living has been witnessed by everyone.

  10. Partial conservation of the sn-2 position of dietary glycerides in fasting plasma lipids in humans.

    NARCIS (Netherlands)

    Zock, P.L.; Gerritsen, J.; Katan, M.B.

    1996-01-01

    The authors investigated the effect of the position of fatty acids within dietary triglycerides on the composition of plasma lipids. Sixty volunteers consumed two diets of equal fatty acid compositions for 3 weeks each. In the palm oil diet 82% of palmitic acid was attached to the sn-1 and sn-3, and

  11. Partial conservation of the sn-2 position of dietary glycerides in fasting plasma lipids in humans.

    NARCIS (Netherlands)

    Zock, P.L.; Gerritsen, J.; Katan, M.B.

    1996-01-01

    The authors investigated the effect of the position of fatty acids within dietary triglycerides on the composition of plasma lipids. Sixty volunteers consumed two diets of equal fatty acid compositions for 3 weeks each. In the palm oil diet 82% of palmitic acid was attached to the sn-1 and sn-3, and

  12. Low-temperature processed SnO2 compact layer for efficient mesostructure perovskite solar cells

    Science.gov (United States)

    Duan, Jinxia; Xiong, Qiu; Feng, Bingjie; Xu, Yang; Zhang, Jun; Wang, Hao

    2017-01-01

    SnO2 nanoparticle film has been synthesized via low- temperature (∼180 °C) solution-processing and proposed as compact layer in mesostructure perovskite-type solar cell (PSC). Low-temperature processed SnO2 compact layer (cl-SnO2) brings perfect crystal-lattice and band-gap matching between electron selective layer and FTO substrate and close interface-contact between cl-SnO2 and mesoporous TiO2 layer (mp-TiO2), which contributes to suppressing carrier recombination and optimizing device performance. In varied thickness cells, 70 nm cl-SnO2 device exhibits maximum power conversion efficiency (PCE). In order to further restrain photoelectron recombination and improve the photovoltaic performance, the surface modification of cl-SnO2 by SnCl4 aqueous solution has been carried out. The recombination behavior in the cell interior is greatly retarded via SnCl4 treatment and champion PSC after SnCl4 treatment has acquire PCE of 15.07%, which is higher than PCE of cl-TiO2 based PSC fabricated with same mp-TiO2 and perovskite procedures (13.3%). The stability of cl-SnO2 PSC via SnCl4 treatment has also been measured and its PCE reduces to 13.0% after 2 weeks in air.

  13. Characteristics of Sn segregation in Ge/GeSn heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Chang, C.; Chen, T. P.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Shi, Z. W.; Chen, H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-10-13

    We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.

  14. Ascl1 as a novel player in the Ptf1a transcriptional network for GABAergic cell specification in the retina.

    Science.gov (United States)

    Mazurier, Nicolas; Parain, Karine; Parlier, Damien; Pretto, Silvia; Hamdache, Johanna; Vernier, Philippe; Locker, Morgane; Bellefroid, Eric; Perron, Muriel

    2014-01-01

    In contrast with the wealth of data involving bHLH and homeodomain transcription factors in retinal cell type determination, the molecular bases underlying neurotransmitter subtype specification is far less understood. Using both gain and loss of function analyses in Xenopus, we investigated the putative implication of the bHLH factor Ascl1 in this process. We found that in addition to its previously characterized proneural function, Ascl1 also contributes to the specification of the GABAergic phenotype. We showed that it is necessary for retinal GABAergic cell genesis and sufficient in overexpression experiments to bias a subset of retinal precursor cells towards a GABAergic fate. We also analysed the relationships between Ascl1 and a set of other bHLH factors using an in vivo ectopic neurogenic assay. We demonstrated that Ascl1 has unique features as a GABAergic inducer and is epistatic over factors endowed with glutamatergic potentialities such as Neurog2, NeuroD1 or Atoh7. This functional specificity is conferred by the basic DNA binding domain of Ascl1 and involves a specific genetic network, distinct from that underlying its previously demonstrated effects on catecholaminergic differentiation. Our data show that GABAergic inducing activity of Ascl1 requires the direct transcriptional regulation of Ptf1a, providing therefore a new piece of the network governing neurotransmitter subtype specification during retinogenesis.

  15. Nebular phase observations of the type-Ib supernova iPTF13bvn favour a binary progenitor

    CERN Document Server

    Kuncarayakti, H; Bersten, M C; Folatelli, G; Morrell, N; Hsiao, E Y; González-Gaitán, S; Anderson, J P; Hamuy, M; de Jaeger, T; Gutiérrez, C P; Kawabata, K S

    2015-01-01

    Aims. We present and analyse late-time observations of the type-Ib supernova with possible pre-supernova progenitor detection, iPTF13bvn, taken at $\\sim$300 days after the explosion, and discuss these in the context of constraints on the supernova's progenitor. Previous studies have proposed two possible natures for the progenitor of the supernova, i.e. a massive Wolf-Rayet star or a lower-mass star in close binary system. Methods. Our observations show that the supernova has entered the nebular phase, with the spectrum dominated by Mg~I]$\\lambda\\lambda$4571, [O~I]$\\lambda\\lambda$6300, 6364, and [Ca~II]$\\lambda\\lambda$7291, 7324 emission lines. We measured the emission line fluxes to estimate the core oxygen mass and compare the [O~I]/[Ca~II] line ratio with other supernovae. Results. The core oxygen mass of the supernova progenitor was estimated to be $\\lesssim$0.7 M$_\\odot$, which implies initial progenitor mass not exceeding $\\sim$15 -- 17 M$_\\odot$. Since the derived mass is too small for a single star to...

  16. Ascl1 as a novel player in the Ptf1a transcriptional network for GABAergic cell specification in the retina.

    Directory of Open Access Journals (Sweden)

    Nicolas Mazurier

    Full Text Available In contrast with the wealth of data involving bHLH and homeodomain transcription factors in retinal cell type determination, the molecular bases underlying neurotransmitter subtype specification is far less understood. Using both gain and loss of function analyses in Xenopus, we investigated the putative implication of the bHLH factor Ascl1 in this process. We found that in addition to its previously characterized proneural function, Ascl1 also contributes to the specification of the GABAergic phenotype. We showed that it is necessary for retinal GABAergic cell genesis and sufficient in overexpression experiments to bias a subset of retinal precursor cells towards a GABAergic fate. We also analysed the relationships between Ascl1 and a set of other bHLH factors using an in vivo ectopic neurogenic assay. We demonstrated that Ascl1 has unique features as a GABAergic inducer and is epistatic over factors endowed with glutamatergic potentialities such as Neurog2, NeuroD1 or Atoh7. This functional specificity is conferred by the basic DNA binding domain of Ascl1 and involves a specific genetic network, distinct from that underlying its previously demonstrated effects on catecholaminergic differentiation. Our data show that GABAergic inducing activity of Ascl1 requires the direct transcriptional regulation of Ptf1a, providing therefore a new piece of the network governing neurotransmitter subtype specification during retinogenesis.

  17. SnET2: clinical update

    Science.gov (United States)

    Razum, Nicholas J.; Snyder, Albert B.; Doiron, Daniel R.

    1996-04-01

    Tin Ethyl Etiopurpurin, SnET2, is a synthetic chlorin analog presently in Phase-II/III clinical trials for the treatment of cutaneous cancers. Trials to date include the treatment of basal cell carcinomas, squamous cell carcinomas, breast adenocarcinomas metastatic to the chest wall and cutaneous Kaposi's sarcomas in AIDS patients. Results to date have shown significant clinical responses for drug doses between 1.0 mg/kg and 1.6 mg/kg, with the threshold for Kaposi's sarcoma being slightly higher than in other indications. Light doses from 100 J/cm2 to 300 J/cm2 were delivered from 24 to 72 hours post SnET2 infusion. Induced transient skin photosensitivity at the lower therapeutic doses has been mild, lasting approximately a week. Results of the Phase I and II trials are presented.

  18. Partial conservation of the sn-2 position of dietary glycerides in fasting plasma lipids in humans.

    OpenAIRE

    Zock, P.L.; Gerritsen, J.; Katan, M. B.

    1996-01-01

    The authors investigated the effect of the position of fatty acids within dietary triglycerides on the composition of plasma lipids. Sixty volunteers consumed two diets of equal fatty acid compositions for 3 weeks each. In the palm oil diet 82% of palmitic acid was attached to the sn-1 and sn-3, and 18% to the sn-2 position of glycerol. In the diet rich in a palm oil analogue, Betapol, these figures were 35% and 65% respectively. Oleic and linoleic acid in palm oil were mainly in the sn-2 pos...

  19. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  20. A Week for Space

    Science.gov (United States)

    Comstock, Diane

    2008-01-01

    Space Week focuses on concepts that enable students to make concrete observations in the early grades (K-2) and move to concepts that help students develop their internet research and writing skills in middle and upper grades (Grades 3-5), and culminates with the development of science investigation design skills (Grade 6). To help launch your…

  1. RNA profiling and chromatin immunoprecipitation-sequencing reveal that PTF1a stabilizes pancreas progenitor identity via the control of MNX1/HLXB9 and a network of other transcription factors

    DEFF Research Database (Denmark)

    Thompson, Nancy; Gésina, Emilie; Scheinert, Peter;

    2012-01-01

    Pancreas development is initiated by the specification and expansion of a small group of endodermal cells. Several transcription factors are crucial for progenitor maintenance and expansion, but their interactions and the downstream targets mediating their activity are poorly understood. Among...... those factors, PTF1a, a basic helix-loop-helix (bHLH) transcription factor which controls pancreas exocrine cell differentiation, maintenance, and functionality, is also needed for the early specification of pancreas progenitors. We used RNA profiling and chromatin immunoprecipitation (ChIP) sequencing...... to identify a set of targets in pancreas progenitors. We demonstrate that Mnx1, a gene that is absolutely required in pancreas progenitors, is a major direct target of PTF1a and is regulated by a distant enhancer element. Pdx1, Nkx6.1, and Onecut1 are also direct PTF1a targets whose expression is promoted...

  2. Soft Robotics Week

    CERN Document Server

    Rossiter, Jonathan; Iida, Fumiya; Cianchetti, Matteo; Margheri, Laura

    2017-01-01

    This book offers a comprehensive, timely snapshot of current research, technologies and applications of soft robotics. The different chapters, written by international experts across multiple fields of soft robotics, cover innovative systems and technologies for soft robot legged locomotion, soft robot manipulation, underwater soft robotics, biomimetic soft robotic platforms, plant-inspired soft robots, flying soft robots, soft robotics in surgery, as well as methods for their modeling and control. Based on the results of the second edition of the Soft Robotics Week, held on April 25 – 30, 2016, in Livorno, Italy, the book reports on the major research lines and novel technologies presented and discussed during the event.

  3. CERN safety week

    CERN Multimedia

    DG Unit

    2009-01-01

    Following an increase in the number of accidents in 2008, the Safety Commission is organising a CERN safety week from 8 to 12 June for riders of bicycles, scooters and motorbikes. We invite you to take part in the programme, which will be held in the Main Building (Bldg. 500) and will consist of an exhibition, organised events and hands-on activities, including demonstrations of emergency braking, a driving simulator, simulation of what it feels like to drive under the influence of alcohol, demonstrations by the Fire Brigade, video projections, etc. There will also be a number of prizes to be won. Please sign up via your DSO.

  4. CERN safety week

    CERN Multimedia

    DG Unit

    2009-01-01

    Following an increase in the number of accidents in 2008, the Safety Commission is organising a CERN safety week from 8 to 12 June for riders of bicycles, scooters and motorbikes. We invite you to take part in the programme, which will be held in the Main Building (Bldg. 500) and will consist of an exhibition, organised events and hands-on activities, including demonstrations of emergency braking, a driving simulator, simulation of what it feels like to drive under the influence of alcohol, demonstrations by the Fire Brigade, video projections, etc. There will also be a number of prizes to be won. Please sign up via your DSO.

  5. a week in space

    Science.gov (United States)

    collette, christian

    2016-04-01

    COLLETTE Christian Institut Saint Laurent Liège Belgium. I am a science teacher at a technical high school. Generally, my students don't come from a privileged social background and are not particularly motivated for studies. For 10 years, I organize, for one of my sections, a spatial (and special) school year that ends in a spatial week. Throughout this year, with the help of my colleagues, I will introduce into all themes a lot of concepts relating to space. French, history, geography, English, mathematics, technical courses, sciences, and even gymnastics will be training actors in space culture. In spring, I will accompany my class in the Euro Space Center (Redu- Belgium) where we will live one week 24 hours on "like astronauts" One third of the time is dedicated to astronaut training (moonwalk, remote manipulator system, mission simulation, weightless wall, building rockets, satellites, etc.), One third to more intellectual activities on space (lectures, research, discovery of the outside run) the last one third of time in outside visits (museums, site of ESA-Redu) or in movies about space (October sky, Apollo 13, etc.) During this year, the profits, so educational as human, are considerable!

  6. ATLAS overview week highlights

    CERN Multimedia

    D. Froidevaux

    2005-01-01

    A warm and early October afternoon saw the beginning of the 2005 ATLAS overview week, which took place Rue de La Montagne Sainte-Geneviève in the heart of the Quartier Latin in Paris. All visitors had been warned many times by the ATLAS management and the organisers that the premises would be the subject of strict security clearance because of the "plan Vigipirate", which remains at some level of alert in all public buildings across France. The public building in question is now part of the Ministère de La Recherche, but used to host one of the so-called French "Grandes Ecoles", called l'Ecole Polytechnique (in France there is only one Ecole Polytechnique, whereas there are two in Switzerland) until the end of the seventies, a little while after it opened its doors also to women. In fact, the setting chosen for this ATLAS overview week by our hosts from LPNHE Paris has turned out to be ideal and the security was never an ordeal. For those seeing Paris for the first time, there we...

  7. Evaporation Mechanism of Sn and SnS from Liquid Fe: Part II: Residual Site and Evaporation Kinetics via Sn(g) and SnS(g)

    Science.gov (United States)

    Jung, Sung-Hoon; Kang, Youn-Bae; Seo, Jeong-Do; Park, Joong-Kil; Choi, Joo

    2015-02-01

    Evaporation of Sn from molten steel was experimentally investigated for Fe-Sn-S alloy with low initial S (0.0007 chemical reaction controlled the evaporation of Sn. The model equation is able to represent the evaporation of Sn in the forms of Sn(g) and SnS(g) simultaneously, from very low S melt (when there is no S) to very high S melt investigated in the present study up to ~0.9 mass pct. Gradual transition of major evaporation species from SnS(g) to Sn(g) was well accounted for by the developed model.

  8. SN 2010j1: Optical to Hard X-Ray Observations Reveal an Explosion Embedded in a Ten Solar Mass Cocoon

    Science.gov (United States)

    Ofek, Eran; Zoglauer, Andreas; Boggs, Steven E.; Barriere, Nicolas M.; Reynolds, Stephen P.; Fryer, Chris L.; Harrison, Fiona A.; Cenko, S. Bradley; Kulkarni, Shrinivas R.; Zhang, William W.; Kulkarni, Shrinivas R.; Gal-Yam, Avishay; Arcavi, Iair; Bellm, Eric; Bloom, Joshua S.; Christensen, Finn; Craig, William W.; Even, Wesley; Filippenko, Alexei V.; Grefenstette, Brian; Hailey, Charles J.; Laher, Russ; Madsen, Kristin; Nakar, Ehud; Nugent, Peter E.; Stern, Daniel; Sullivan, Mark; Surace, Jason; Zhang, William W.

    2014-01-01

    Some supernovae (SNe) may be powered by the interaction of the SN ejecta with a large amount of circumstellar matter (CSM). However, quantitative estimates of the CSM mass around such SNe are missing when the CSM material is optically thick. Specifically, current estimators are sensitive to uncertainties regarding the CSM density profile and the ejecta velocity. Here we outline a method to measure the mass of the optically thick CSM around such SNe. We present new visible-light and X-ray observations of SN 2010jl (PTF 10aaxf), including the first detection of an SN in the hard X-ray band using NuSTAR. The total radiated luminosity of SN 2010jl is extreme atleast 9 1050 erg. By modeling the visible-light data, we robustly show that the mass of the circumstellar material within 1016 cm of the progenitor of SN 2010jl was in excess of 10M_. This mass was likely ejected tens of years prior to the SN explosion. Our modeling suggests that the shock velocity during shock breakout was 6000 km s1, decelerating to 2600 km s1 about 2 yr after maximum light. Furthermore, our late-time NuSTAR and XMM spectra of the SN presumably provide the first direct measurement of SN shock velocity 2 yr after the SN maximum light measured to be in the range of 2000-4500 km s1 if the ions and electrons are in equilibrium, and_2000 km s1 if they are not in equilibrium. This measurement is in agreement with the shock velocity predicted by our modeling of the visible-light data. Our observations also show that the average radial density distribution of the CSM roughly follows an r2 law. A possible explanation for the _10M_ of CSM and the wind-like profile is that they are the result of multiple pulsational pair instability events prior to the SN explosion, separated from each other by years.

  9. Constraints on the origin of the first light from SN2014J

    CERN Document Server

    Goobar, A; Siverd, R; Stassun, K G; Pepper, J; Amanullah, R; Kasliwal, M; Sollerman, J; Taddia, F

    2014-01-01

    We study the very early lighcturves of supernova 2014J (SN2014J) using the high-cadence broad-band imaging data obtained by the Kilodegree Extremely Little Telescope (KELT), which fortuitously observed M82 around the time of the explosion, starting in November 2013 with up to 20 observations per night. These observations are complemented by observations in two narrow-band filters used in an H$\\alpha$ survey of nearby galaxies by the intermediate Palomar Transient Factory (iPTF) that also captured the first days of the brightening of the supernova. The evolution of the lightcurves is consistent with the expected signal from the cooling of shock heated material of large scale dimensions, $\\ge$ $1 R_{\\odot}$. This could be due to heated material of the progenitor, a companion star or pre-existing circumstellar environment, e.g., in the form of an accretion disk. Structure seen in the lightcurves during the first days after explosion could also originate from radioactive material in the outer parts of an explodin...

  10. A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova

    Science.gov (United States)

    Oates, Samantha; Holland, Stephen; Immler, Stefan; Brown, Peter J.; Dawson, Kyle S.; DePasquale, Massimiliano; Gronwall, Caryl; Kuin, Paul; Mazzali, Paolo; Miline, Peter; Siegel, Michael

    2012-01-01

    We present the earliest ultraviolet (UV) observations of the bright Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a distance of only 6.4 Mpc. It was discovered shortly after explosion by the Palomar Transient Factory and first observed by Swift/UVOT about a day after explosion. The early UV light is well-defined, with approx. 20 data points per filter in the 5 days after explosion. With these early UV observations, we extend the near-UV template of SNe Ia to earlier times for comparison with observations at low and high redshift and report fits from semiempirical models of the explosion. We find the early UV count rates to be well fit by the superposition of two parabolic curves. Finally, we use the early UV flux measurements to examine a possible shock interaction with a non-degenerate companion. We find that even a solar mass companion at a distance of a few solar radii is unlikely at more than 95% confidence.

  11. A memorable week

    CERN Document Server

    2012-01-01

    This has been a memorable week for CERN, starting with the award of a Special Fundamental Physics Prize and ending with the handover of the CERN Council Presidency from Michel Spiro to Agnieszka Zalewska. In between, the LHC team demonstrated its expertise with a successful pilot run with 25 nanosecond bunch spacing, a new application for Associate Membership was received, and we had good news on the budget.   The award of the Fundamental Physics Prize, and the manner in which it was divided between ATLAS, CMS and the LHC, is fitting recognition of the efforts of the thousands of people who have contributed over many years to the success of our flagship scientific endeavour. In making the award, the Milner Foundation aims to raise the profile of fundamental physics and its value to society. The Fundamental Physics Prize comes hot on the heels of the European Physical Society’s first Edison Volta Prize, which Sergio Bertolucci, Steve Myers and I were honoured to accept on behalf of t...

  12. Highly Variable Extinction and Accretion in the Jet-driving Class I Type Young Star PTF 10nvg (V2492 Cyg, IRAS 20496+4354)

    CERN Document Server

    Hillenbrand, Lynne A; Covey, Kevin R; Carpenter, John M; Cenko, S Bradley; Silverman, Jeffrey M; Muirhead, Philip; Fischer, William; Crepp, Justin R; Bloom, Joshua S; Filippenko, Alexei V

    2012-01-01

    [abbreviated] We report extensive photometry and spectroscopy of the highly variable young stellar object PTF 10nvg including optical, near-infrared, mid-infrared, and millimeter data. Following the 2010 maximum and subsequent fade, during 2011 and 2012 the source underwent additional episodes of brightening followed by several magnitude dimming events consistent with extinction variations. Further, a ~221 day period is derived; 2010 data taken when the source was near maximum brightness do not phase well to this period, however. Spectral evolution includes changes in slope and correlated changes in the prominence of TiO/VO/CO and atomic emission. These are anticorrelated with changes in forbidden emission which, along with H_2, dominate at faint epochs. Notably, night-to-night variations in several forbidden doublet strengths and ratios are observed. High-dispersion spectra in a variety of photometric states reveal line profiles for atomic species likely formed in an accretion flow and/or impact. The origin ...

  13. PTF1 J191905.19+481506.2—A partially eclipsing AM CVn system discovered in the Palomar transient factory

    Energy Technology Data Exchange (ETDEWEB)

    Levitan, David; Groot, Paul J.; Prince, Thomas A.; Kulkarni, Shrinivas R.; Hallinan, Gregg; Harding, Leon K.; Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Kupfer, Thomas [Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Margon, Bruce [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Kyne, Gillian [Centre for Astronomy, School of Physics, National University of Ireland, Galway (Ireland); Laher, Russ; Surace, Jason [Spitzer Science Center, MS 314-6, California Institute of Technology, Pasadena, CA 91125 (United States); Ofek, Eran O. [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Rutten, René G. M. [GRANTECAN S.A. Cuesta de San José, s/n, E-38712 Breña Baja, La Palma (Spain)

    2014-04-20

    We report on PTF1 J191905.19+481506.2, a newly discovered, partially eclipsing, outbursting AM CVn system found in the Palomar Transient Factory synoptic survey. This is only the second known eclipsing AM CVn system. We use high-speed photometric observations and phase-resolved spectroscopy to establish an orbital period of 22.4559(3) minutes. We also present a long-term light curve and report on the normal and super-outbursts regularly seen in this system, including a super-outburst recurrence time of 36.8(4) days. We use the presence of the eclipse to place upper and lower limits on the inclination of the system and discuss the number of known eclipsing AM CVn systems versus what would be expected.

  14. Galaxy Formation and SN Feedback

    CERN Document Server

    Tissera, P B; White, S D M; Springel, V

    2006-01-01

    We present a Supernova (SN) feedback model that succeeds at describing the chemical and energetic effects of SN explosions in galaxy formation simulations. This new SN model has been coupled to GADGET-2 and works within a new multiphase scheme which allows the description of a co-spatial mixture of cold and hot interstellar medium phases. No ad hoc scale-dependent parameters are associated to these SN and multiphase models making them particularly suited to studies of galaxy formation in a cosmological framework. Our SN model succeeds not only in setting a self-regulated star formation activity in galaxies but in triggering collimated chemical-enriched galactic winds. The effects of winds vary with the virial mass of the systems so that the smaller the galaxy, the larger the fraction of swept away gas and the stronger the decrease in its star formation activity. The fact that the fraction of ejected metals exceeds 60 per cent regardless of mass, suggests that SN feedback can be the responsible mechanism of th...

  15. PROTEUS-SN User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Shemon, Emily R. [Argonne National Lab. (ANL), Argonne, IL (United States); Smith, Micheal A. [Argonne National Lab. (ANL), Argonne, IL (United States); Lee, Changho [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-16

    PROTEUS-SN is a three-dimensional, highly scalable, high-fidelity neutron transport code developed at Argonne National Laboratory. The code is applicable to all spectrum reactor transport calculations, particularly those in which a high degree of fidelity is needed either to represent spatial detail or to resolve solution gradients. PROTEUS-SN solves the second order formulation of the transport equation using the continuous Galerkin finite element method in space, the discrete ordinates approximation in angle, and the multigroup approximation in energy. PROTEUS-SN’s parallel methodology permits the efficient decomposition of the problem by both space and angle, permitting large problems to run efficiently on hundreds of thousands of cores. PROTEUS-SN can also be used in serial or on smaller compute clusters (10’s to 100’s of cores) for smaller homogenized problems, although it is generally more computationally expensive than traditional homogenized methodology codes. PROTEUS-SN has been used to model partially homogenized systems, where regions of interest are represented explicitly and other regions are homogenized to reduce the problem size and required computational resources. PROTEUS-SN solves forward and adjoint eigenvalue problems and permits both neutron upscattering and downscattering. An adiabatic kinetics option has recently been included for performing simple time-dependent calculations in addition to standard steady state calculations. PROTEUS-SN handles void and reflective boundary conditions. Multigroup cross sections can be generated externally using the MC2-3 fast reactor multigroup cross section generation code or internally using the cross section application programming interface (API) which can treat the subgroup or resonance table libraries. PROTEUS-SN is written in Fortran 90 and also includes C preprocessor definitions. The code links against the PETSc, METIS, HDF5, and MPICH libraries. It optionally links against the MOAB library and

  16. Laser processing issues of nanosized intermetallic Fe-Sn and metallic Sn particles

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrescu, R., E-mail: ralexandrescu2001@yahoo.co.uk [National Institute for Lasers, Plasma and Radiation Physics Bucharest, POB MG-36, 077125 (Romania); Morjan, I.; Dumitrache, F.; Birjega, R.; Fleaca, C.; Morjan, Iuliana; Scarisoreanu, M.; Luculescu, C.R.; Dutu, E. [National Institute for Lasers, Plasma and Radiation Physics Bucharest, POB MG-36, 077125 (Romania); Kuncser, V.; Filoti, G. [National Institute of Materials Physics, POB MG-7, 077125 Bucharest-Magurele (Romania); Vasile, E. [Metav R and D, Rosetti 31, Bucharest (Romania); Ciupina, V. [Ovidius University of Constanta, Bd. Mamaia 124, Constanta (Romania)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Intermetallic Fe-Sn and metallic Sn nanoparticles synthesized by laser pyrolysis. Black-Right-Pointing-Pointer Fe(CO){sub 5} and Sn(CH{sub 3}){sub 4} were used as precursors. Black-Right-Pointing-Pointer FeSn{sub 2}, Sn and Fe{sub 3}SnC phases were identified by XRD. Black-Right-Pointing-Pointer Complex core-shell structural characteristics were found by HRTEM analysis. Black-Right-Pointing-Pointer Higher magnetization was found in samples with increased Fe/Sn atomic ratio. - Abstract: Intermetallic Fe-Sn and nanocrystalline metallic Sn nanoparticles have been successfully synthesized from organic precursors using the laser pyrolysis technique with ethylene as sensitizer. Nano-structured Sn (single phase) was prepared by the pyrolysis of Sn(CH{sub 3}){sub 4} (TMT) vapors. Controlled Fe/Sn atomic ratios, ranging from 0.69 to 1.64 were obtained for the prepared Fe-Sn nanopowders by the control of Fe(CO){sub 5} and TMT flows, respectively. XRD studies evidence three main phases: the tetragonal metallic Sn phase and the intermetallic FeSn{sub 2} phase and, to a much lesser extent, the cubic ternary carbide Fe{sub 3}SnC. Complex core-shell structural characteristics were found by HRTEM analysis. More complete information about the Fe phase distributions in the new intermetallic Fe-Sn nanomaterial is provided by temperature dependent {sup 57}Fe Moessbauer spectroscopy.

  17. Directed and Elliptic Flows in 112Sn+112Sn Collisions

    Institute of Scientific and Technical Information of China (English)

    张虎勇; 马余刚; 余礼平; 沈文庆; 蔡翔舟; 方德清; 钟晨; 韩定定

    2001-01-01

    The directed and elliptic flows in collisions of 112Sn+112Sn at energies from 35 to 90 MeV/nucleon are studied inan isospin-dependent quantum molecule dynamics model. With increasing incident energy, the directed flow risesfrom negative to positive. Its magnitude depends on the nuclear equation of state (EOS). However, the ellipticflow decreases with increasing incident energy and its magnitude is not very sensitive to EOS. Systematic studiesof the impact parameter dependence and the cluster mass dependence are also performed. The study of directedflow at intermediate energies thus provides a means of extracting the information on the nuclear equation of state.

  18. Elective caesarean section at 38 weeks versus 39 weeks

    DEFF Research Database (Denmark)

    Glavind, Julie; Kindberg, S F; Uldbjerg, N;

    2013-01-01

    To investigate whether elective caesarean section before 39 completed weeks of gestation increases the risk of adverse neonatal or maternal outcomes.......To investigate whether elective caesarean section before 39 completed weeks of gestation increases the risk of adverse neonatal or maternal outcomes....

  19. WBDOC Weekly Workload Status Report

    Data.gov (United States)

    Social Security Administration — Weekly reports of workloads processed in the Wilkes Barre Data Operation Center. Reports on quantities of work received, processed, pending and average processing...

  20. Thermodynamic description of Sn-Y and Mg-Sn-Y systems

    Institute of Scientific and Technical Information of China (English)

    吕东显; 郭翠萍; 李长荣; 杜振民

    2014-01-01

    The thermodynamic optimization of the Sn-Y and Mg-Sn-Y systems was critically carried out by means of the CALPHAD (CALculation of PHAse Diagram) technique. In the Sn-Y system, the solution phases (liquid, bcc, bct and hcp) were described by the substitutional solution model. The compound Sn3Y5, which has a homogeneity range, was treated as the formula (Sn, Y)3(Sn, Y)2Y3 by a three-sublattice model in accordance with the site occupancies. In the Mg-Sn-Y system, the liquid phase was treated as the for-mula (Mg, Sn, Y, Mg2Sn) using an associated solution model, and bcc, bct and hcp were treated as the formula (Mg, Sn, Y). The compound Sn3Y5 was treated as the formula (Sn, Y, Mg)3(Sn, Y, Mg)2Y3. The ternary compound MgSnY was treated as stoichiomet-ric compound. A set of self-consistent thermodynamic parameters of the Mg-Sn-Y system was obtained. The projection of the liq-uidus surfaces and the reaction scheme of the Mg-Sn-Y system were predicted.

  1. La5Zn2Sn

    Directory of Open Access Journals (Sweden)

    Igor Oshchapovsky

    2011-11-01

    Full Text Available A single crystal of pentalanthanum dizinc stannide, La5Zn2Sn, was obtained from the elements in a resistance furnace. It belongs to the Mo5SiB2 structure type, which is a ternary ordered variant of the Cr5B3 structure type. The space is filled by bicapped tetragonal antiprisms from lanthanum atoms around tin atoms sharing their vertices. Zinc atoms fill voids between these bicapped tetragonal antiprisms. All four atoms in the asymmetric unit reside on special positions with the following site symmetries: La1 (..m; La2 (4/m..; Zn (m.2m; Sn (422.

  2. Structural Characteristics of Liquid Sn

    Institute of Scientific and Technical Information of China (English)

    WU Ai-Qing; GUO Li-Jun; LIU Chang-Song; ZHU Zhen-Gang

    2005-01-01

    @@ We investigate the structural properties of liquid Sn. With the help of the internal friction (tan φ) method, it is found that a peak appears in the tan φ - T curve, suggesting that an anomalous discontinuous temperature induced structure change may take place in liquid Sn. From the experimental data of pair distribution functions, we calculate the viscosity η and the excess entropy S and it is found that there are a peak of viscosity in the η - T curve and a bend of excess entropy in the S - T curve, which give a positive support to the appearance of the internal-friction peak in the tan φ - T curve.

  3. SN 2009E: a faint clone of SN 1987A

    DEFF Research Database (Denmark)

    Pastorello, A.; Pumo, M. L.; Navasardyan, H.

    2012-01-01

    Context.1987A-like events form a rare sub-group of hydrogen-rich core-collapse supernovae that are thought to originate from the explosion of blue supergiant stars. Although SN 1987A is the best known supernova, very few objects of this group have been discovered and, hence, studied. Aims. In thi...

  4. Epitaxial growth of strained and unstrained GeSn alloys up to 25% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Oehme, Michael, E-mail: oehme@iht.uni-stuttgart.de; Kostecki, Konrad; Schmid, Marc; Oliveira, Filipe; Kasper, Erich; Schulze, Jörg

    2014-04-30

    Strained and unstrained GeSn layers on Si substrates were grown with Sn contents up to 20% and 25%, respectively. All metastable layer structures were fabricated by means of an ultra-low temperature molecular beam epitaxy process. The useful thickness of the metastable layers for a range of Sn contents, growth temperatures and two different strain values (unstrained, compressive strained) is explored. The epitaxial breakdown thickness which limits the useful thickness range decreases exponentially with increasing growth temperature and Sn concentration. - Highlights: • GeSn epitaxy • GeSn layers with Sn contents up to 25% • Limited layer thickness.

  5. Golden Week: A Holiday Revolution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ As one of the most important and far-reaching focal points in people's lives, the Golden-Week holiday, is much more than a year 21-day vacation. How did the Golden Week take shape over the past few years, gradually attracting people's attention, and having an increasingly important impact in China each year?

  6. Laser processing issues of nanosized intermetallic Fe-Sn and metallic Sn particles

    Science.gov (United States)

    Alexandrescu, R.; Morjan, I.; Dumitrache, F.; Birjega, R.; Fleaca, C.; Morjan, Iuliana; Scarisoreanu, M.; Luculescu, C. R.; Dutu, E.; Kuncser, V.; Filoti, G.; Vasile, E.; Ciupina, V.

    2012-09-01

    Intermetallic Fe-Sn and nanocrystalline metallic Sn nanoparticles have been successfully synthesized from organic precursors using the laser pyrolysis technique with ethylene as sensitizer. Nano-structured Sn (single phase) was prepared by the pyrolysis of Sn(CH3)4 (TMT) vapors. Controlled Fe/Sn atomic ratios, ranging from 0.69 to 1.64 were obtained for the prepared Fe-Sn nanopowders by the control of Fe(CO)5 and TMT flows, respectively. XRD studies evidence three main phases: the tetragonal metallic Sn phase and the intermetallic FeSn2 phase and, to a much lesser extent, the cubic ternary carbide Fe3SnC. Complex core-shell structural characteristics were found by HRTEM analysis. More complete information about the Fe phase distributions in the new intermetallic Fe-Sn nanomaterial is provided by temperature dependent 57Fe Mössbauer spectroscopy.

  7. Excellent Li-ion storage performances of hierarchical SnO-SnO2 composite powders and SnO nanoplates prepared by one-pot spray pyrolysis

    Science.gov (United States)

    Kim, Jung Hyun; Jeon, Kyung Min; Park, Jin-Sung; Kang, Yun Chan

    2017-08-01

    Hierarchical-structured SnO-SnO2 composite powders and SnO nanoplates with some SnO2 nanorods are prepared by one-pot spray pyrolysis. Dicyandiamide dissolved in the spray solution plays a key role in the preparation of the hierarchical-structured SnO-SnO2 composite powder and SnO nanoplates. The hierarchical-structured SnO-SnO2 composite powders, in which the SnO nanoplates are trapped in the porous SnO2 nanosphere, are prepared by spray pyrolysis at 800 °C. Sufficient conversion of the porous SnO2 nanospheres to SnO at 900 °C results in aggregation-free SnO2 nanoplates. SnO2 nanorods with a spherical nanodroplet at the tip are formed by Ostwald ripening. The hierarchical-structured SnO-SnO2 composite powder having high structural stability during repeated lithium alloying and dealloying reactions, shows superior discharge capacities and rate performances for lithium-ion storage compared to those of the dense-structured SnO2 powders. The discharge capacities of the hierarchical-structured SnO-SnO2 composite powders, SnO nanoplates with SnO2 nanorods, and dense-structured SnO2 powders at a current density of 1 A g-1 for the 300th cycle are 561, 504, and 416 mA h g-1, respectively. The SnO nanoplates with SnO2 nanorods and hierarchical-structured SnO-SnO2 powders deliver high reversible discharge capacities of 433 and 379 mA h g-1 at an extremely high current density of 10 A g-1, respectively.

  8. Structure and vibrational dynamics of interfacial Sn layers in Sn/Si multilayers

    Science.gov (United States)

    Cuenya, B. Roldan; Keune, W.; Sturhahn, W.; Toellner, T. S.; Hu, M. Y.

    2001-12-01

    The structure and vibrational dynamics of room-temperature-grown nanoscale Sn/amorphous (a-)Si multilayers have been studied by x-ray diffraction, Raman scattering, 119Sn Mössbauer spectroscopy, and 119Sn nuclear-resonant inelastic x-ray scattering (NRIXS) of synchrotron radiation. With increasing Sn-layer thickness, the formation of β-Sn was observed, except at the Sn/Si interfaces, where a 10-Å-thick metastable pure amorphous-α-Sn-like layer remains stabilized. By means of NRIXS we have measured the Sn-projected vibrational density of states (VDOS) in these multilayers (in particular, at the interfaces), and in 500-Å-thick epitaxial α-Sn films on InSb(001) as a reference. Further, the Sn-specific Lamb-Mössbauer factor (f factor), mean kinetic energy per atom, mean atomic force constant, and vibrational entropy per atom were obtained. The VDOS of the amorphous-α-Sn-like interface layer is observed to be distinctly different from that of (bulk) α-Sn and β-Sn, and its prominent vibrational energies are found to scale with those of amorphous Ge and Si. The observed small difference in vibrational entropy (ΔS/kB=+0.17+/-0.05 per atom) between α-Sn and interfacial amorphous-α-like Sn does not account for the stability of the latter phase.

  9. Influence of the Sn oxidation state in ferromagnetic Sn-doped In2O3 nanowires

    Science.gov (United States)

    Maloney, Francis Scott; Wang, Wenyong

    2016-12-01

    Sn-doped indium oxide nanowires were grown using a vapor-liquid-solid technique (VLS). The Sn content of the nanowires was tunable based on the source powder ratios used in the VLS process. The oxidation state of the Sn ions was examined using x-ray photoelectron spectroscopy. It was found that Sn2+ was the dominant ionic species in samples over 6% (atomic percentage) Sn. The nanowires were found to be ferromagnetic at room temperature, and their saturation magnetization increased with increasing Sn concentration, which could be associated with the spin-splitting of a defect band that was encouraged by the imbalance of Sn2+ to Sn4+ species at high Sn concentrations.

  10. AGN Luminosity and Stellar Age: Two Missing Ingredients for AGN Unification as Seen with iPTF Supernovae

    Science.gov (United States)

    Villarroel, Beatriz; Nyholm, Anders; Karlsson, Torgny; Comerón, Sébastien; Korn, Andreas J.; Sollerman, Jesper; Zackrisson, Erik

    2017-03-01

    Active galactic nuclei (AGNs) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo of AGN classes is divided into two major groups, with Type-1 AGNs displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that a Type-2 AGN is a Type-1 AGN viewed through a dusty kiloparsec-sized torus, but an emerging body of observations suggests more than just the viewing angle matters. Here we report significant differences in supernova (SN) counts and classes in the first study to date of SNe near Type-1 and Type-2 AGN host galaxies, using data from the intermediate Palomar Transient Factory, the Sloan Digital Sky Survey Data Release 7, and Galaxy Zoo. We detect many more SNe in Type-2 AGN hosts (size of effect ˜5.1σ) compared to Type-1 hosts, which shows that the two classes of AGN are located inside host galaxies with different properties. In addition, Type-1 and Type-2 AGNs that are dominated by star formation according to Wide-field Infrared Survey Explorer colors {m}W1-{m}W2< 0.5 and are matched in 22 μm absolute magnitude differ by a factor of ten in L[O iii] λ5007 luminosity, suggesting that when residing in similar types of host galaxies Type-1 AGNs are much more luminous. Our results demonstrate two more factors that play an important role in completing the current picture: the age of stellar populations and the AGN luminosity. This has immediate consequences for understanding the many AGN classes and galaxy evolution.

  11. La5Zn2Sn

    Science.gov (United States)

    Oshchapovsky, Igor; Pavlyuk, Volodymyr; Dmytriv, Grygoriy; Chumak, Igor; Ehrenberg, Helmut

    2011-01-01

    A single crystal of penta­lanthanum dizinc stannide, La5Zn2Sn, was obtained from the elements in a resistance furnace. It belongs to the Mo5SiB2 structure type, which is a ternary ordered variant of the Cr5B3 structure type. The space is filled by bicapped tetra­gonal anti­prisms from lanthanum atoms around tin atoms sharing their vertices. Zinc atoms fill voids between these bicapped tetra­gonal anti­prisms. All four atoms in the asymmetric unit reside on special positions with the following site symmetries: La1 (..m); La2 (4/m..); Zn (m.2m); Sn (422). PMID:22219730

  12. The ATLAS Glasgow Overview Week

    CERN Multimedia

    Richard Hawkings

    2007-01-01

    The ATLAS Overview Weeks always provide a good opportunity to see the status and progress throughout the experiment, and the July week at Glasgow University was no exception. The setting, amidst the traditional buildings of one of the UK's oldest universities, provided a nice counterpoint to all the cutting-edge research and technology being discussed. And despite predictions to the contrary, the weather at these northern latitudes was actually a great improvement on the previous few weeks in Geneva. The meeting sessions comprehensively covered the whole ATLAS project, from the subdetector and TDAQ systems and their commissioning, through to offline computing, analysis and physics. As a long-time ATLAS member who remembers plenary meetings in 1991 with 30 people drawing detector layouts on a whiteboard, the hardware and installation sessions were particularly impressive - to see how these dreams have been translated into 7000 tons of reality (and with attendant cabling, supports and services, which certainly...

  13. Controlling the antibacterial activity of CuSn thin films by varying the contents of Sn

    Science.gov (United States)

    Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol

    2016-12-01

    We investigated antibacterial activity of CuSn thin films against Gram positive Staphylococcus aureus (S. aureus). CuSn thin films with different Cu to Sn ratios were deposited on Si(100) by radio frequency (RF) magnetron sputtering method using Cu and Sn metal anodes. The film thickness was fixed at 200 nm by varying the sputtering time and RF power on the metal targets. The antibacterial test was conducted in various conditions such as different contact times and Cu to Sn ratios in the CuSn films. The antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time between the film and bacteria suspension increased execpt in the case of CuSn-83. The oxidation states of Cu and Sn and the chemical composition of CuSn thin films before and after the antibacterial test were investigated by X-ray photoelectron spectroscopy (XPS). When the contact time was fixed, the Cu species was further oxidized as the RF power on Cu target increased. The intensity of Sn 3d decreased with increasing Cu ratio. When the sample was fixed, the peak intensity of Sn 3d decreased as the contact time increased due to the permeation of Sn into the cell.

  14. Investigation of the Phase Equilibria of Sn-Cu-Au Ternary and Ag-Sn-Cu-Au Quaternary Systems and Interfacial Reactions in Sn-Cu/Au Couples

    Science.gov (United States)

    Yen, Yee-Wen; Jao, Chien-Chung; Hsiao, Hsien-Ming; Lin, Chung-Yung; Lee, Chiapyng

    2007-02-01

    The phase equilibria of the Sn-Cu-Au ternary, Ag-Sn-Cu-Au quaternary systems and interfacial reactions between Sn-Cu alloys and Au were experimentally investigated at specific temperatures in this study. The experimental results indicated that there existed three ternary intermetallic compounds (IMCs) and a complete solid solubility between AuSn and Cu6Sn5 phases in the Sn-Cu-Au ternary system at 200°C. No quaternary IMC was found in the isoplethal section of the Ag-Sn-Cu-Au quaternary system. Three IMCs, AuSn, AuSn2, and AuSn4, were found in all couples. The same three IMCs and (Au,Cu)Sn/(Cu,Au)6Sn5 phases were found in all Sn-Cu/Au couples. The thickness of these reaction layers increased with increasing temperature and time. The mechanism of IMC growth can be described by using the parabolic law. In addition, when the reaction time was extended and the Cu content of the alloy was increased, the AuSn4 phase disappeared gradually. The (Au, Cu)Sn and (Cu,Au)6Sn5 layers played roles as diffusion barriers against Sn in Sn-Cu/Au reaction couple systems.

  15. Partial conservation of the sn-2 position of dietary triglycerides in fasting plasma lipids in humans.

    Science.gov (United States)

    Zock, P L; Gerritsen, J; Katan, M B

    1996-02-01

    The authors investigated the effect of the position of fatty acids within dietary triglycerides on the composition of plasma lipids. Sixty volunteers consumed two diets of equal fatty acid compositions for 3 weeks each. In the palm oil diet 82% of palmitic acid was attached to the sn-1 and sn-3, and 18% to the sn-2 position of glycerol. In the diet rich in a palm oil analogue, Betapol, these figures were 35% and 65% respectively. Oleic and linoleic acid in palm oil were mainly in the sn-2 position, and in Betapol mainly in the sn-1 and sn-3 position. The proportion of palmitic acid in the 2 position of fasting plasma triglycerides was 10·2 g 100 g-1 on palm oil and 12·3 on Betapol; that of oleic acid was 46·dot 9 vs. 43·6 (P oil (P = 0·002). Betapol increased palmitic and palmitoleic acid in cholesteryl esters by 1 g 100 g-1 (P fat absorption and chylomicron clearance.

  16. Fashion Week Illumes Fashion Life

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Nine days, 46 domestic and overseas brands, 30 designers from China and abroad, 41 fashion shows, six professional fashion design competitions, as well as ten press conferences and fashion forums, this is the menu of Mercedes-Benz China Fashion Week (A/W 2012/2013) this March.

  17. Updated Physical Parameters of SN 2012cg

    Science.gov (United States)

    Marion, G. H.; Challis, P.; Hicken, M.; Mandel, K.; Meyer, S.; Kirshner, R. P.; Foley, R. J.; Friedman, A.; Irwin, J.; Wood-Vasey, W. M.; Wheeler, J. C.; Vinko, J.; Rines, K.; Wilhelmy, S.; Macri, L.

    2012-06-01

    The Harvard-Smithsonian Center for Astrophysics Supernova Group reports photometric and spectroscopic observations of SN 2012cg (ATEL #4115, #4159). We find that SN 2012cg has a slow decline rate and low expansion velocities. BayeSN fits to the data show that SN 2012cg has significant dust extinction (A_v ~ 0.67 mag). We find R_v = 2.7 +/- 0.5, which is consistent with the Milky Way value of 3.1 and mildly inconsistent with the extremely low values reported for some highly reddened SN (e.g., R_v = 1.59 +/- 0.07 for SN 2002cv; Elias-Rosa et al.

  18. Process modules for GeSn nanoelectronics with high Sn-contents

    Science.gov (United States)

    Schulte-Braucks, C.; Glass, S.; Hofmann, E.; Stange, D.; von den Driesch, N.; Hartmann, J. M.; Ikonic, Z.; Zhao, Q. T.; Buca, D.; Mantl, S.

    2017-02-01

    This paper systematically studies GeSn n-FETs, from individual process modules to a complete device. High-k gate stacks and NiGeSn metallic contacts for source and drain are characterized in independent experiments. To study both direct and indirect bandgap semiconductors, a range of 0-14.5 at.% Sn-content GeSn alloys are investigated. Special emphasis is placed on capacitance-voltage (C-V) characteristics and Schottky-barrier optimization. GeSn n-FET devices are presented including temperature dependent I-V characteristics. Finally, as an important step towards implementing GeSn in tunnel-FETs, negative differential resistance in Ge0.87Sn0.13 tunnel-diodes is demonstrated at cryogenic temperatures. The present work provides a base for further optimization of GeSn FETs and novel tunnel FET devices.

  19. Gamma-ray lines from SN2014J

    CERN Document Server

    Siegert, Thomas

    2015-01-01

    On 21 January 2014, SN2014J was discovered in M82 and found to be the closest type Ia supernova (SN Ia) in the last four decades. INTEGRAL observed SN2014J from the end of January until late June for a total exposure time of about 7 Ms. SNe Ia light curves are understood to be powered by the radioactive decay of iron peak elements of which $^{56}$Ni is dominantly synthesized during the thermonuclear disruption of a CO white dwarf (WD). The measurement of $\\gamma$-ray lines from the decay chain $^{56}$Ni$\\rightarrow$$^{56}$Co$\\rightarrow$$^{56}$Fe provides unique information about the explosion in supernovae. Canonical models assume $^{56}$Ni buried deeply in the supernova cloud, absorbing most of the early $\\gamma$-rays, and only the consecutive decay of $^{56}$Co should become directly observable through the overlaying material several weeks after the explosion when the supernova envelope dilutes as it expands. Surprisingly, with the spectrometer on INTEGRAL, SPI, we detected $^{56}$Ni $\\gamma$-ray lines at ...

  20. Efficacy of the LiSN & Learn auditory training software: randomized blinded controlled study

    Directory of Open Access Journals (Sweden)

    Sharon Cameron

    2012-09-01

    Full Text Available Children with a spatial processing disorder (SPD require a more favorable signal-to-noise ratio in the classroom because they have difficulty perceiving sound source location cues. Previous research has shown that a novel training program - LiSN & Learn - employing spatialized sound, overcomes this deficit. Here we investigate whether improvements in spatial processing ability are specific to the LiSN & Learn training program. Participants were ten children (aged between 6;0 [years;months] and 9;9 with normal peripheral hearing who were diagnosed as having SPD using the Listening in Spatialized Noise - Sentences test (LiSN-S. In a blinded controlled study, the participants were randomly allocated to train with either the LiSN & Learn or another auditory training program - Earobics - for approximately 15 min per day for twelve weeks. There was a significant improvement post-training on the conditions of the LiSN-S that evaluate spatial processing ability for the LiSN & Learn group (P=0.03 to 0.0008, η 2=0.75 to 0.95, n=5, but not for the Earobics group (P=0.5 to 0.7, η 2=0.1 to 0.04, n=5. Results from questionnaires completed by the participants and their parents and teachers revealed improvements in real-world listening performance post-training were greater in the LiSN & Learn group than the Earobics group. LiSN & Learn training improved binaural processing ability in children with SPD, enhancing their ability to understand speech in noise. Exposure to non-spatialized auditory training does not produce similar outcomes, emphasizing the importance of deficit-specific remediation.

  1. Pseudomorphic GeSn/Ge (001) heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Tonkikh, A. A., E-mail: tonkikh@mpi-halle.de [Max Planck Institute of Microstructure Physics (Germany); Talalaev, V. G. [Martin Luther University Halle-Wittenberg, ZIK SiLi-nano (Germany); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

    2013-11-15

    The synthesis of pseudomorphic GeSn heterostructures on a Ge (001) substrate by molecular-beam epitaxy is described. Investigations by transmission electron microscopy show that the GeSn layers are defect free and possess cubic diamondlike structure. Photoluminescence spectroscopy reveals interband radiative recombination in the GeSn quantum wells, which is identified as indirect transitions between the subbands of heavy electrons and heavy holes. On the basis of experimental data and modeling of the band structure of pseudomorphic GeSn compounds, the lower boundary of the bowing parameter for the indirect band gap is estimated as b{sub L} {>=} 1.47 eV.

  2. Topological crystalline insulator SnTe nanoribbons

    Science.gov (United States)

    Dahal, Bishnu R.; Dulal, Rajendra P.; Pegg, Ian L.; Philip, John

    2017-03-01

    Topological crystalline insulators are systems in which a band inversion that is protected by crystalline mirror symmetry gives rise to nontrivial topological surface states. SnTe is a topological crystalline insulator. It exhibits p-type conductivity due to Sn vacancies and Te antisites, which leads to high carrier density in the bulk. Thus growth of high quality SnTe is a prerequisite for understanding the topological crystalline insulating behavior. We have grown SnTe nanoribbons using a solution method. The width of the SnTe ribbons varies from 500 nm to 2 μm. They exhibit rock salt crystal structure with a lattice parameter of 6.32 Å. The solution method that we have adapted uses low temperature, so the Sn vacancies can be controlled. The solution grown SnTe nanoribbons exhibit strong semiconducting behavior with an activation energy of 240 meV. This activation energy matches with the calculated band gap for SnTe with a lattice parameter of 6.32 Å, which is higher than that reported for bulk SnTe. The higher activation energy makes the thermal excitation of bulk charges very difficult on the surface. As a result, the topological surfaces will be free from the disturbance caused by the thermal excitations

  3. The Double Peaked SN2013ge: a Type Ib/c SN with an Early Asymmetric Mass Ejection or an Extended Progenitor Envelope

    CERN Document Server

    Drout, M R; Parrent, J; Margutti, R; Kamble, A; Soderberg, A M; Challis, P; Chornock, R; Fong, W; Frank, S; Gehrels, N; Graham, M L; Hsiao, E; Itagaki, K; Kasliwal, M; Kirshner, R P; Macomb, D; Marion, G H; Norris, J; Phillips, M M

    2015-01-01

    We present extensive observations of the Type Ib/c SN2013ge from -13 to +457 days, including spectra and Swift UV-optical photometry beginning 2-4 days post explosion. This makes SN2013ge one of the best observed normal Type Ib/c SN at early times, when the light curve is particularly sensitive to the progenitor configuration and mixing of radioactive elements. These early observations reveal two distinct light curve components in the UV bands. The first component rises over 4-5 days and is visible for a week post-explosion. Spectra of the first component have a blue continuum and show a plethora of high velocity (~14,000 km/s) but narrow (~3500 km/s) features, indicating that the line forming region is restricted. The explosion parameters estimated for the bulk explosion are standard for Type Ib/c SN, while detailed analysis of optical and NIR spectra identify weak He features at early times, and nebular spectra show evidence for mixing and asymmetry in the bulk ejecta. In addition, SN2013ge exploded in a lo...

  4. The melting diagram of the Ti-Dy-Sn system below 40 at.% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Fartushna, Y.; Meleshevich, K.; Samelyuk, A.; Bulanova, M. [Frantsevich Inst. for Problems of Materials Science of NASU, Kiev (Ukraine)

    2010-10-15

    Phase equilibria in the Ti-Dy-Sn system below 40 at.% Sn were studied using differential thermal analysis, X-ray diffraction, metallography and electron microprobe. The partial liquidus and solidus projections and the melting diagram (liquidus + solidus) were constructed. A new ternary compound {tau} with composition Ti{sub 4.2-4.3}Dy{sub 0.8-0.7}Sn{sub {approx_lt}3}, found by us previously, melts congruently above 1543 C and coexists with all the phases based on the binary compounds of the boundary binaries in the concentration interval studied. The liquidus surface is characterized by primary crystallization regions of ({beta}Ti), ({beta}Dy), ({alpha}Dy), (Ti{sub 3}Sn), (Ti{sub 2}Sn), (Ti{sub 5}Sn{sub 3}), (Dy{sub 5}Sn{sub 3}) and {tau}. Five three-phase fields in the solidus surface result from three eutectic and two transition type invariant four-phase equilibria: L{sub E{sub 1}} {r_reversible} ({beta}Ti) + (Ti{sub 3}Sn) + (Dy{sub 5}Sn{sub 3}), L{sub E{sub 2}} {r_reversible} (Ti{sub 3}Sn) + {tau} + (Dy{sub 5}Sn{sub 3}), L{sub E{sub 3}} {r_reversible} ({beta}Ti) + ({alpha}Dy) + (Dy{sub 5}Sn{sub 3}), L{sub U{sub 1}} + (Ti{sub 2}Sn) {r_reversible} (Ti{sub 3}Sn) + {tau} and L{sub U{sub 2}} + (Ti{sub 2}Sn) {r_reversible} (Ti{sub 5}Sn{sub 3}) + {tau} at 1524, 1500, 1150, 1543 and 1498 C, respectively. In the two-phase areas ({beta}Ti) + (Dy{sub 5}Sn{sub 3}),(Ti{sub 3}Sn) + (Dy{sub 5}Sn{sub 3}), (Ti{sub 2}Sn) + {tau} and {tau} + (Dy{sub 5}Sn{sub 3}) the solidus surface has the temperature maxima at 1620, 1540, > 1543 and > 1500 C, respectively. (orig.)

  5. ATLAS Overview Week at Brookhaven

    CERN Multimedia

    Pilcher, J

    Over 200 ATLAS participants gathered at Brookhaven National Laboratory during the first week of June for our annual overview week. Some system communities arrived early and held meetings on Saturday and Sunday, and the detector interface group (DIG) and Technical Coordination also took advantage of the time to discuss issues of interest for all detector systems. Sunday was also marked by a workshop on the possibilities for heavy ion physics with ATLAS. Beginning on Monday, and for the rest of the week, sessions were held in common in the well equipped Berkner Hall auditorium complex. Laptop computers became the norm for presentations and a wireless network kept laptop owners well connected. Most lunches and dinners were held on the lawn outside Berkner Hall. The weather was very cooperative and it was an extremely pleasant setting. This picture shows most of the participants from a view on the roof of Berkner Hall. Technical Coordination and Integration issues started the reports on Monday and became a...

  6. A Luminous Peculiar Type Ia Supernova SN 2011hr: More Like SN 1991T or SN 2007if?

    CERN Document Server

    Zhang, Jujia; Sasdelli, Michele; Zhang, Tianmeng; Liu, Zhengweei; Mazzali, Paolo A; Meng, Xiangcun; Maeda, Keiichi; Chen, Juncheng; Huang, Fang; Zhao, Xulin; Zhang, Kaicheng; Zhai, Qian; Pian, Elena; Wang, Bo; Chang, Liang; Yi, Weimin; Wang, Chuan-Jun; Wang, Xueli; Xin, Yuxin; Wang, Jianguo; Lun, Baoli; Zheng, Xiangming; Zhang, Xiliang; Fan, Yufeng; Bai, Jinming

    2015-01-01

    Photometric and spectroscopic observations of a slowly declining, luminous type Ia supernova (SN Ia) 2011hr in the star-burst galaxy NGC 2691 are presented. SN~2011hr is found to peak at $M_{B}=-19.84 \\pm 0.40\\,\\rm{mag}$, with a post-maximum decline rate $\\Delta$m$_{15}$(B) = 0.92 $\\pm$ 0.03\\,$\\rm{mag}$. From the maximum-light bolometric luminosity, $L=(2.30 \\pm 0.90) \\times 10^{43}\\,\\rm{erg\\,s^{-1}}$, we estimate the mass of synthesized \\Nifs\\ in SN~2011hr to be $M(\\rm{^{56}Ni})=1.11 \\pm 0.43\\,M_{\\sun}$. SN 2011hr appears more luminous than SN 1991T at around maximum light, and the absorption features from its intermediate-mass elements (IMEs) are noticeably weaker than the latter at similar phases. Spectral modelling suggests that SN 2011hr has the IMEs of $\\sim$\\,0.07 M$_{\\sun}$ in the outer ejecta, which is much lower than the typical value of normal SNe Ia (i.e., 0.3 -- 0.4 M$_{\\sun}$) and is also lower than the value of SN 1991T (i.e., $\\sim$\\,0.18 M$_{\\sun}$). These results indicate that SN~2011hr may ...

  7. Process Modules for GeSn Nanoelectronics with high Sn-contents

    OpenAIRE

    Schulte-Braucks, C; Glass, S; Hofmann, E; Stange, D; Von Den Driesch, N; Hartmann, JM; Ikonic, Z; Zhao, GT; Buca, D.; Mantl, S

    2017-01-01

    This paper systematically studies GeSn n-FETs, from individual process modules to a complete device. High-k gate stacks and NiGeSn metallic contacts for source and drain are characterized in independent experiments. To study both direct and indirect bandgap semiconductors, a range of 0 at.% to 14.5 at.% Sn-content GeSn alloys are investigated. Special emphasis is placed on capacitance-voltage (C-V) characteristics and Schottky-barrier optimization. GeSn n-FET devices are presented including t...

  8. Effect of Sn Content in a CuSnZn Metal Precursor on Formation of MoSe2 Film during Selenization in Se+SnSe Vapor

    OpenAIRE

    Liyong Yao; Jianping Ao; Ming-Jer Jeng; Jinlian Bi; Shoushuai Gao; Guozhong Sun; Qing He; Zhiqiang Zhou; Yun Sun; Liann-Be Chang

    2016-01-01

    The preparation of Cu2ZnSnSe4 (CZTSe) thin films by the selenization of an electrodeposited copper–tin–zinc (CuSnZn) precursor with various Sn contents in low-pressure Se+SnSex vapor was studied. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) measurements revealed that the Sn content of the precursor that is used in selenization in a low-pressure Se+SnSex vapor atmosphere only slightly affects the elemental composition of the formed CZTSe films. However, the Sn co...

  9. GeSn/SiGeSn photonic devices for mid-infrared applications: experiments and calculations

    Science.gov (United States)

    Han, Genquan; Zhang, Qingfang; Liu, Yan; Zhang, Chunfu; Hao, Yue

    2016-11-01

    In this work, a fully strained GeSn photodetector with Sn atom percent of 8% is fabricated on Ge buffer on Si(001) substrate. The wavelength λ of light signals with obvious optical response for Ge0.92Sn0.08 photodetector is extended to 2 μm. The impacts of compressive strain introduced during the epitaxial growth of GeSn on Ge/Si are studied by simulation. Besides, the tensile strain engineering of GeSn photonic devices is also investigated. Lattice-matched GeSn/SiGeSn double heterostructure light emitting diodes (LEDs) with Si3N4 tensile liner stressor are designed to promote the further mid-infrared applications of GeSn photonic devices. With the releasing of the residual stress in Si3N4 liner, a large biaxial tensile strain is induced in GeSn active layer. Under biaxial tensile strain, the spontaneous emission rate rsp and internal quantum efficiency ηIQE for GeSn/SiGeSn LED are significantly improved.

  10. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  11. Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects

    Science.gov (United States)

    Lee, Tae-Kyu; Liu, Bo; Zhou, Bite; Bieler, Thomas; Liu, Kuo-Chuan

    2011-09-01

    The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.

  12. Effect of graphite content on electrochemical performance of Sn-SnSb/graphite composite powders

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sn-SnSb alloy was synthesized by reducing a aqueous solution containing Sn( Ⅱ ) and Sb(Ⅲ) salts with NaBH4 in the presence of sodium citrate. The product was characterized by X-ray diffractometry(XRD) and scanning electron microscopy(SEM).Sn-SnSb/graphite composite powders were prepared by mechanical milling and the mass fraction of graphite was increased from20% to 50%. The effect of graphite content on the electrochemical performance of Sn-SnSb/graphite composite electrode was investigated. The results show the increase of graphite content is in favor of enhancing the first charge-discharge efficiency and improving the cycle performance, but the capacity of the composite electrode decreases with increasing content of graphite.

  13. Laser spectroscopy of neutron deficient Sn isotopes

    CERN Multimedia

    We propose to study the ground state properties of neutron-deficient Sn isotopes towards the doubly-magic nucleus $^{100}$Sn. Nuclear spins, changes in the rms charge radii and electromagnetic moments of $^{101-121}$Sn will be measured by laser spectroscopy using the CRIS experimental beam line. These ground-state properties will help to clarify the evolution of nuclear structure properties approaching the $\\textit{N = Z =}$ 50 shell closures. The Sn isotopic chain is currently the frontier for the application of state-of-the-art ab-initio calculations. Our knowledge of the nuclear structure of the Sn isotopes will set a benchmark for the advances of many-body methods, and will provide an important test for modern descriptions of the nuclear force.

  14. Electrodeposition of nanostructured Sn-Zn coatings

    Science.gov (United States)

    Salhi, Y.; Cherrouf, S.; Cherkaoui, M.; Abdelouahdi, K.

    2016-03-01

    The electrodeposition of Sn-Zn coating at ambient temperature was investigated. The bath consists of metal salts SnCl2·2H2O and ZnSO4·7H2O and sodium citrate (NaC6H5Na3O7·2H2O) as complexing agent. To prevent precipitation, the pH is fixed at 5. Reducing tin and zinc through Sncit2- and ZnHcit- complex respectively is confirmed by the presence of two cathodic peaks on the voltammogram. The kinetic of tin (II) reduction process is limited by the SnCit2- dissociation. The SEM and TEM observations have showed that the coating consists of a uniform Sn-Zn layer composed of fine grains on which tin aggregates grow up. XRD revealed peaks corresponding to the hexagonal Zn phase and the tetragonal β-Sn phase.

  15. Application of 119Sn CPMG MAS NMR for Fast Characterization of Sn Sites in Zeolites with Natural 119Sn Isotope Abundance

    DEFF Research Database (Denmark)

    G. Kolyagin, Yury; V. Yakimo, Alexander; Tolborg, Søren

    2016-01-01

    119Sn CPMG MAS NMR is demonstrated to be a fast and efficient method for characterization of Sn-sites in Sn-containing zeolites. Tuning of the CPMG echo-train sequence decreases the experimental time by a factor of 5–40 in the case of as-synthesized and hydrated Sn-BEA samples and by 3 orders......-BEA zeolites with natural 119Sn isotope abundance using conventional MAS NMR equipment....

  16. Growth of a Au-Ni-Sn intermetallic compound on the solder-substrate interface after aging

    Energy Technology Data Exchange (ETDEWEB)

    Minor, Andrew M.; Morris, J.W., Jr.

    1999-12-16

    Au/Ni metallization has become increasingly common in microelectronic packaging when Cu pads are joined with Pb-Sn solder. The outermost Au layer serves to protect the pad from corrosion and oxidation and the Ni layer provides a diffusion barrier to inhibit detrimental growth of Cu-Sn intermetallics. As a result of reflowing eutectic Pb-Sn on top of Au/Ni metallization, the as-solidified joints have AuSn{sub 4} precipitates distributed throughout the bulk of the solder joint, and Ni{sub 3}Sn{sub 4} intermetallics at the interface. Recent work has shown that the Au-Sn redeposits onto the interface during aging, compromising the strength of the joint. The present work shows that the redeposited intermetallic layer is a ternary compound with stoichiometry Au{sub 0.5}Ni{sub 0.5}Sn{sub 4}. The growth of this intermetallic layer was investigated, and results show that the ternary compound is observed to grow after as little as 3 hours at 150 C and after 3 weeks at 150 C has grown to a thickness of 10 {micro}m. Additionally, methods for inhibiting the growth of the ternary layer were investigated and it was determined that multiple reflows, both with and without additional aging can substantially limit the thickness of the ternary layer.

  17. Growth of a Au-Ni-Sn intermetallic compound on the solder-substrate interface after aging

    Energy Technology Data Exchange (ETDEWEB)

    Minor, Andrew M. [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Au/Ni metallization has become increasingly common in microelectronic packaging when Cu pads are joined with Pb-Sn solder. The outermost Au layer serves to protect the pad from corrosion and oxidation and the Ni layer provides a diffusion barrier to inhibit detrimental growth of Cu-Sn intermetallics. As a result of reflowing eutectic Pb-Sn on top of Au/Ni metallization, the as-solidified joints have AuSn4 precipitates distributed throughout the bulk of the solder joint, and Ni3Sn4 intermetallics at the interface. Recent work has shown that the Au-Sn redeposits onto the interface during aging, compromising the strength of the joint. The present work shows that the redeposited intermetallic layer is a ternary compound with stoichiometry Au0.5Ni0.5Sn4. The growth of this intermetallic layer was investigated, and results show that the ternary compound is observed to grow after as little as 3 hours at 150°C and after 3 weeks at 150°C has grown to a thickness of 10 μm. Additionally, methods for inhibiting the growth of the ternary layer were investigated and it was determined that multiple reflows, both with and without additional aging can substantially limit the thickness of the ternary layer.

  18. Synthesis of Epitaxial Films Based on Ge-Si-Sn Materials with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn Heterojunctions

    Science.gov (United States)

    Timofeev, V. A.; Kokhanenko, A. P.; Nikiforov, A. I.; Mashanov, V. I.; Tuktamyshev, A. R.; Loshkarev, I. D.

    2015-11-01

    Results of investigations into the synthesis of heterostructures based on Ge-Si-Sn materials by the method of low-temperature molecular beam epitaxy are presented. The formation of epitaxial films during structure growth has been controlled by the reflection high-energy electron diffraction method. Films with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions are grown with Sn content changing from 2 to 10 % at temperatures in the interval 150-350°C. The stressed state, the composition, and the lattice parameter are studied by the x-ray diffraction method using Omega-scan curves and reciprocal space maps. A tensile strain in the Ge film during Ge/Ge0.9Sn0.1/Si structure growth has reached 0.86%.

  19. Direct observation of Sn crystal growth during the lithiation and delithiation processes of SnO(2) nanowires.

    Science.gov (United States)

    Zhang, Li Qiang; Liu, Xiao Hua; Perng, Ya-Chuan; Cho, Jea; Chang, Jane P; Mao, Scott X; Ye, Zhi Zhen; Huang, Jian Yu

    2012-11-01

    Tin (Sn) crystal growth on Sn-based anodes in lithium ion batteries is hazardous for reasons such as possible short-circuit failure by Sn whiskers and Sn-catalyzed electrolyte decomposition, but the growth mechanism of Sn crystals during battery cycling is not clear. Here we report different growth mechanisms of Sn crystal during the lithiation and delithiation processes of SnO(2) nanowires revealed by in situ transmission electron microscopy (TEM). Large spherical Sn nanoparticles with sizes of 20-200nm grew instantaneously upon lithiation of a single-crystalline SnO(2) nanowire at large current density (j>20A/cm(2)), which suppressed formation of the Li(x)Sn alloy but promoted agglomeration of Sn atoms. Control experiments of Joule-heating (j≈2400A/cm(2)) the pristine SnO(2) nanowires resulted in melting of the SnO(2) nanowires but not Sn particle growth, indicating that the abnormal Sn particle growth was induced by both chemical reduction (i.e., breaking the SnO(2) lattice to produce Sn atoms) and agglomeration of the Sn atoms assisted by Joule heating. Intriguingly, Sn crystals grew out of the nanowire surface via a different "squeeze-out" mechanism during delithiation of the lithiated SnO(2) nanowires coated with an ultra-thin solid electrolyte LiAlSiO(x) layer. It is attributed to the negative stress gradient generated by the fast Li extraction in the surface region through the Li(+)-conducting LiAlSiO(x) layer. Our previous studies showed that Sn precipitation does not occur in the carbon-coated SnO(2) nanowires, highlighting the effect of nanoengineering on tailoring the electrochemical reaction kinetics to suppress the hazardous Sn whiskers or nanoparticles formation in a lithium ion battery.

  20. Facile Routes to NiF(6)(2)(-), AgF(4)(-), AuF(6)(-), and PtF(6)(-) Salts Using O(2)(+) as a Source of O(2)F in Anhydrous HF.

    Science.gov (United States)

    Lucier, G. M.; Shen, C.; Elder, S. H.; Bartlett, N.

    1998-07-27

    O(2)(+) salts dissolved in liquid anhydrous hydrogen fluoride (aHF) at 20 degrees C or below oxidize aHF solutions of PtF(6)(2)(-) to PtF(6)(-). The parent base of O(2)(+) salts in aHF (O(2)F((solv))) generated with alkali fluoride is long-lived below -50 degrees C. An aHF solution of O(2)F((solv)) oxidizes Au(III) to Au(V) below -50 degrees C (2O(2)F((solv)) + AuF(4)(-)((solv)) --> AuF(6)(-)((solv)) +2O(2(g))). In situ generation of O(2)F((solv)) (O(2)(+)((solv)) + F(-)((solv)) --> O(2)F((solv))) with AgF(2) or NiF(2) in suspension in the aHF made basic with alkali fluoride gives AgF(4)(-) and NiF(6)(2)(-)salts. Low solubility of AAsF(6)(A = Cs, K) in aHF provides for the metathetical preparation of (O(2))(2)PdF(6) solutions in aHF. Removal of aHF, even at -60 degrees C, results in some O(2) and F(2) loss, to a composition approaching (O(2))PdF(5).

  1. The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube

    DEFF Research Database (Denmark)

    Hanotel, Julie; Bessodes, Nathalie; Thélie, Aurore

    2014-01-01

    The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing gene...... and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube....... and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural...... tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic...

  2. Plaque control evaluation of a stabilized stannous fluoride dentifrice compared to a triclosan dentifrice in a six-week trial.

    Science.gov (United States)

    Sharma, N; He, T; Barker, M L; Biesbrock, A R

    2013-01-01

    To compare the anti-plaque efficacy of a stabilized 0.454% stannous fluoride (referred to as SnF2) dentifrice versus a 0.3% triclosan dentifrice formulated with a copolymer and sodium fluoride (referred to as triclosan). The study had a randomized, double-blind, two-treatment, parallel-group design, and compared plaque reduction from baseline after both three and six weeks of treatment with either the SnF2 or triclosan dentifrices using a manual toothbrush. Subjects brushed their teeth using their assigned treatment dentifrices according to the manufacturer's instructions. Following overnight plaque accumulation, levels of plaque were assessed by an experienced examiner using the Rustogi, et al. Modified Navy Plaque Index at the start of the study (baseline), and after three and six weeks of regular brushing. Groups were compared using analysis of covariance separately for Weeks 3 and 6, and by repeated measures for Weeks 3 and 6 combined. One-hundred and twenty subjects were randomized to treatment and 114 subjects completed the study. Both treatment groups showed a statistically significant reduction from baseline in mean plaque values for all three tooth areas (whole mouth, gingival margin, interproximal) at both Weeks 3 and 6 (p dentifrices showed statistically significant reductions from baseline in whole mouth, gumline, and interproximal accumulated overnight plaque after three and six weeks of brushing, but the SnF2 dentifrice showed statistically significantly greater plaque reductions versus the triclosan dentifrice.

  3. Efficacy of the LiSN & Learn Auditory Training Software: randomized blinded controlled study

    Directory of Open Access Journals (Sweden)

    Sharon Cameron

    2012-01-01

    Full Text Available Background: Children with a spatial processing disorder (SPD require a more favorable signal-to-noise ratio in the classroom because they have difficulty perceiving sound source location cues. Previous research has shown that a novel training program - LiSN & Learn - employing spatialized sound, overcomes this deficit. Here we investigate whether improvements in spatial processing ability are specific to the LiSN & Learn training program. Materials and methods: Participants were ten children (aged between 6;0 [years;months] and 9;9 with normal peripheral hearing who were diagnosed as having SPD using the Listening in Spatialized Noise – Sentences Test (LISN-S. In a blinded controlled study, the participants were randomly allocated to train with either the LiSN & Learn or another auditory training program – Earobics - for approximately 15 minutes per day for twelve weeks. Results: There was a significant improvement post-training on the conditions of the LiSN-S that evaluate spatial processing ability for the LiSN & Learn group (p=0.03 to 0.0008, η2=0.75 to 0.95, n=5, but not for the Earobics group (p=0.5 to 0.7, η2=0.1 to 0.04, n=5. Results from questionnaires completed by the participants and their parents and teachers revealed improvements in real-world listening performance post-training were greater in the LiSN & Learn group than the Earobics group. Conclusions: LiSN & Learn training improved binaural processing ability in children with SPD, enhancing their ability to understand speech in noise. Exposure to non-spatialized auditory training does not produce similar outcomes, emphasizing the importance of deficit-specific remediation.

  4. Dynamic viscosities of pure tin and Sn-Ag, Sn-Cu, and Sn-Ag-Cu eutectic melts

    Science.gov (United States)

    Rozhitsina, E. V.; Gruner, S.; Kaban, I.; Hoyer, W.; Sidorov, V. E.; Popel', P. S.

    2011-02-01

    The dynamic viscosities of the melts of pure tin and eutectic Sn-Ag, Sn-Cu, and Sn-Ag-Cu alloys are studied in heating followed by cooling, and the maximum heating temperature was 1200°C. An irreversible decrease in the viscosity is found in the temperature range 800-1000°C in the polytherms of all melts. This finding is related to the loss of a local order in a melt and can be used to develop temperature regimes for the production of lead-free solders.

  5. 119Sn Mössbauer studies on ferromagnetic and photocatalytic Sn-TiO2 nanocrystals

    Science.gov (United States)

    Ganeshraja, Ayyakannu Sundaram; Nomura, Kiyoshi; Wang, Junhu

    2016-12-01

    Diluted Sn doped TiO2 nanocrystals (Sn/Ti ratio: x ≤ 1.37 %) were synthesized by a simple hydrothermal method using pure reagents without any surfactant and dispersant material. The XRD of these samples showed an anatase phase, anatase and rutile mixed phases, and a rutile phase of TiO2 and SnO2 with the increase of Sn dopant concentrations. 119Sn Mössbauer spectra gave the broad peaks, which were decomposed into doublets and sextets because almost all these samples showed magnetic hysteresis even at room temperature. The titanium oxides doped with x ≤ 0.12 % showed the relatively large magnetic hysteresis and high photocatalytic activity. Mössbauer spectra of samples doped with x > 0.3 % were analyzed by one doublet and two sextets although the samples showed weak ferromagnetism. Three kinds of Sn species may be distinguished as Sn 4+ substituted TiO2 and two different magnetic arrangements of Sn doped TiO2: one with more oxygen defects and other at the interface of TiO2 and precipitated SnO2 containing Ti atoms. The correlation between various amounts of Sn sites and photocatalytic activity and/ or magnetic property was discussed.

  6. Growth of highly textured SnS on mica using an SnSe buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C., E-mail: charles.surya@polyu.edu.hk

    2014-08-01

    We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer.

  7. SN 2004A: Another Type II-P Supernova with a Red Supergiant Progenitor

    CERN Document Server

    Hendry, M A; Cenko, S B; Crockett, R M; Fox, D W; Gal-Yam, A; Kudritzki, R P; Maund, J R; Moon, D S; Smartt, S J

    2006-01-01

    We present a monitoring study of SN 2004A and probable discovery of a progenitor star in pre-explosion HST images. The photometric and spectroscopic monitoring of SN 2004A show that it was a normal Type II-P which was discovered in NGC 6207 about two weeks after explosion. We compare SN 2004A to the similar Type II-P SN 1999em and estimate an explosion epoch of 2004 January 6. We also calculate three new distances to NGC 6207 of 21.0 +/-4.3, 21.4 +/-3.5 and 25.1 +/-1.7Mpc. The former was calculated using the Standard Candle Method (SCM) for SNe II-P, and the latter two from the Brightest Supergiants Method (BSM). We combine these three distances with existing kinematic distances, to derive a mean value of 20.3 +/-3.4Mpc. Using this distance we estimate that the ejected nickel mass in the explosion is 0.046(+0.031,-0.017) Msolar. The progenitor of SN 2004A is identified in pre-explosion WFPC2 F814W images with a magnitude of mF814W = 24.3 +/-0.3, but is below the detection limit of the F606W images. We show th...

  8. Beta decay of {sup 101}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O.; Kavatsyuk, M. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); National Taras Shevchenko Univ. of Kyiv (Ukraine); Mazzocchi, C. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Univ. of Tennessee, Knoxville (United States); Janas, Z.; Karny, M.; Miernik, K.; Plochocki, A.; Zylicz, J. [University of Warsaw (Poland); Banu, A.; Becker, F.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Klepper, O.; Kirchner, R.; Plettner, C.; Roeckl, E.; Schaedel, M. [Gesellschaft fuer Schwerionenforschung, Darmstadt, Darmstadt (Germany); Batist, L. [St. Petersburg Nuclear Physics Institute (Russian Federation); Blazhev, A. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Univ. of Sofia (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen (Germany); Jungclaus, A. [Instituto Estructura de la Materia, CSIC (Spain); Departamento de Fisica Teorica, UAM, Madrid (Spain); La Commara, M.; Romoli, M. [Universita ' ' Federico II' ' , Napoli (Italy); INFN, Napoli (Italy); Mukha, I. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Kurchatov Inst., Moscow (Russian Federation); Rykaczewski, K. [Oak Ridge National Laboratory, Oak Ridge (United States); Schmidt, K. [Continental Teves AG and Co., Frankfurt am Main (Germany); Schwengner, R. [Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany)

    2007-03-15

    The {beta} decay of the very neutron-deficient isotope {sup 101}Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors for {gamma}-ray spectroscopy. Based on the {beta}-delayed proton data the production cross-section of {sup 101}Sn in the {sup 50}Cr+{sup 58}Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of {sup 101}Sn was measured to be 1.9(3)s. For the first time {beta}-delayed {gamma}-rays of {sup 101}Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in {sup 101}In. The results for the {sup 101}Sn decay as well as those from previous work on the {sup 103}Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction in the {sup 88}Sr to {sup 132}Sn model space. (orig.)

  9. Axions and SN1987A

    Science.gov (United States)

    Burrows, Adam; Turner, Michael S.; Brinkmann, R. P.

    1988-01-01

    The effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN1987A is considered. It is found that for an axion mass of greater than approximately 10 to the -3 eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, the possibility has not been investigated that axion trapping (which should occur for masses greater than or equal to 0.02 eV) sufficiently reduces axion emission so that axion masses greater than approximately 2 eV would be consistent with the neutrino observations.

  10. Comparison of Catabolic Rates of sn-1, sn-2, and sn-3 Fatty Acids in Triacylglycerols Using (13)CO2 Breath Test in Mice.

    Science.gov (United States)

    Beppu, Fumiaki; Kawamatsu, Takashi; Yamatani, Yoshio; Nagai, Toshiharu; Yoshinaga, Kazuaki; Mizobe, Hoyo; Yoshida, Akihiko; Kubo, Atsushi; Kanda, Jota; Gotoh, Naohiro

    2017-01-01

    Fatty acids in triacylglycerols (TAGs) are catabolized after digestion. However, the catabolic rates of the fatty acids at the sn-1, sn-2, and sn-3 positions of TAGs have not been compared. To elucidate the differences, we studied the catabolic rates of (13)C-labeled palmitic acid, oleic acid, and capric acid at the sn-1, sn-2, or sn-3 position of TAGs using isotope-ratio mass spectrometry. Specifically, we measured the (13)C-to-(12)C ratio in CO2 (Δ(13)C (‰)) exhaled by mice. For all analyzed fatty acids, we observed significant differences between sn-2 and other binding positions. In contrast, no significant difference was detected between the sn-1 and sn-3 positions. These results indicated that the catabolic rates of fatty acids are strongly influenced by their positions in TAGs.

  11. Monodisperse and inorganically capped Sn and Sn/SnO2 nanocrystals for high-performance Li-ion battery anodes.

    Science.gov (United States)

    Kravchyk, Kostiantyn; Protesescu, Loredana; Bodnarchuk, Maryna I; Krumeich, Frank; Yarema, Maksym; Walter, Marc; Guntlin, Christoph; Kovalenko, Maksym V

    2013-03-20

    We report a facile synthesis of highly monodisperse colloidal Sn and Sn/SnO2 nanocrystals with mean sizes tunable over the range 9-23 nm and size distributions below 10%. For testing the utility of Sn/SnO2 nanocrystals as an active anode material in Li-ion batteries, a simple ligand-exchange procedure using inorganic capping ligands was applied to facilitate electronic connectivity within the components of the nanocrystalline electrode. Electrochemical measurements demonstrated that 10 nm Sn/SnO2 nanocrystals enable high Li insertion/removal cycling stability, in striking contrast to commercial 100-150 nm powders of Sn and SnO2. In particular, reversible Li-storage capacities above 700 mA h g(-1) were obtained after 100 cycles of deep charging (0.005-2 V) at a relatively high current of 1000 mA h g(-1).

  12. Effect of Sn Content in a CuSnZn Metal Precursor on Formation of MoSe2 Film during Selenization in Se+SnSe Vapor

    Directory of Open Access Journals (Sweden)

    Liyong Yao

    2016-03-01

    Full Text Available The preparation of Cu2ZnSnSe4 (CZTSe thin films by the selenization of an electrodeposited copper–tin–zinc (CuSnZn precursor with various Sn contents in low-pressure Se+SnSex vapor was studied. Scanning electron microscope (SEM and energy dispersive spectroscopy (EDS measurements revealed that the Sn content of the precursor that is used in selenization in a low-pressure Se+SnSex vapor atmosphere only slightly affects the elemental composition of the formed CZTSe films. However, the Sn content of the precursor significantly affects the grain size and surface morphology of CZTSe films. A metal precursor with a very Sn-poor composition produces CZTSe films with large grains and a rough surface, while a metal precursor with a very Sn-rich composition procures CZTSe films with small grains and a compact surface. X-ray diffraction (XRD and SEM revealed that the metal precursor with a Sn-rich composition can grow a thicker MoSe2 thin film at CZTSe/Mo interface than one with a Sn-poor composition, possibly because excess Sn in the precursor may catalyze the formation of MoSe2 thin film. A CZTSe solar cell with an efficiency of 7.94%was realized by using an electrodeposited metal precursor with a Sn/Cu ratio of 0.5 in selenization in a low-pressure Se+SnSex vapor.

  13. Single-Particle States in $^{133}$Sn

    CERN Multimedia

    Huck, A

    2002-01-01

    % IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.

  14. A busy week for Council

    CERN Multimedia

    2009-01-01

    This has been a busy week for the CERN Council, and there is much to report. Firstly, I’m pleased to say that Council approved the Organization’s Medium Term Plan, and with it the budget for financial year 2010. In a time of global recession, this is a strong vote of confidence from the Member States. This meeting of Council provided an opportunity for the working group on the scientific and geographical enlargement of CERN to set out a roadmap towards its final report, which is to be made at Council’s December session this year. One part of the process over the coming months is to bring the major players in particle physics from beyond the European region into the discussion, ensuring that the working group’s recommendations lead to an optimum position for CERN and European particle physics in the global context. An indicator of the continuing attractiveness of CERN is the fact that Council has received four new applications...

  15. Web Lectures - ATLAS Overview Week

    CERN Multimedia

    Tushar Bhatnagar; Jeremy Herr; Mitch McLachlan; Homer A. Neal

    2007-01-01

    ATLAS Web Archives Web Archives of the ATLAS Overview Week in Glasgow are now available from the University of Michigan portal here. Archives of ATLAS Plenary Sessions, Workshops, Meetings, and Tutorials recorded over the past two years are available via the University of Michigan Lecture Portal. Other recent additions include the ROOT Workshop held at CERN on March 26-27, the Physics Analysis Tools Workshop held in Bergen, Norway on April 23-27, and the CTEQ Workshop: "Physics at the LHC: Early Challenges" held at Michigan State University on May 14-15. Viewing requires a standard Web browser with RealPlayer plug-in (included in most browsers automatically) and works on any major platform. Lectures can be viewed directly over the Web or downloaded locally. In addition, you will find access to a variety of general tutorials and events via the portal. Feedback & Suggestions Welcome Suggestions for events or tutorials to record in 2007, as well as feedback on existing archives, is always welcome...

  16. SN Hunt 248: a super-Eddington outburst from a massive cool hypergiant

    CERN Document Server

    Mauerhan, Jon C; Graham, Melissa L; Zheng, WeiKang; Clubb, Kelsey I; Filippenko, Alexei V; Valenti, Stefano; Brown, Peter J; Smith, Nathan; Howell, D Andrew; Arcavi, Iair

    2014-01-01

    We present photometric and spectroscopic observations of SN Hunt 248, a new supernova (SN) impostor in NGC 5806, which experienced a multi-stage outburst in May-June 2014. The initial "2014a" brightening that led to this object's discovery began with an absolute magnitude of -12, at which point the source exhibited the characteristics of a cool dense outflow, having a spectrum dominated by P-Cygni lines of Fe II, H I, and Na I, as well as strong line blanketing from metals (at the blue end). After two weeks of slow incline, the source rapidly climbed and peaked near M=-15 mag after two more weeks. During this bright "2014b" phase the source radiated a total energy of ~10^49 ergs, while the spectrum became dominated by Balmer emission and a stronger blue continuum, similar in appearance to the SN impostor SN 1997bs. Archival images of the host galaxy from the Hubble Space Telescope between 1997 and 2005 have revealed a luminous and variable precursor star. Its location on the HR diagram is consistent with a ma...

  17. Abnormal growth of Ag3Sn intermetallic compounds in Sn-Ag lead-free solder

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun; LIU Yongchang; GAO Houxiu

    2006-01-01

    The abnormal growth of Ag3Sn intermetallic compounds in eutectic Sn-3.5% Ag solder was investigated through high-temperature aging treatment. Microstructural evolutions of this solder before and after the aging treatment were observed by optical microscopy and scanning electron microscopy. Precise differential thermal analysis was made to study the changes in enthalpies of the solder under different conditions. The results reveal that the water-cooled solder is in metastable thermodynamic state due to the high free energy of Ag3Sn nanoparticles, which sporadically distribute in the matrix as second-phase. The second-phase Ag3Sn nanoparticles aggregate rapidly and grow to form bulk intermetallic compounds due to the migration of grain boundary between primary Sn-rich phase and the Ag3Sn nanoparticles during high temperature aging treatment.

  18. Influence of Solid Fraction on Gravity Segregation of Sn in Al-20Sn Alloy Casting

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of solid fraction of Al-20Sn alloy mushy on gravity segregation of Sn in casting was studied and, the relationship between solid fraction and the temperature of alloy mushy and that between solid fraction of alloy mushy and size of Sn particle in ingot were determined. The results show that the relationship between solid fraction and the temperature of alloy mushy was fs=1683-4.86t+0.0035t2. The extent of gravity segregation of Sn in casting reduced gradually with the increasing of solid fraction of alloy mushy. When solid fraction of alloy mushy was arger than 40%, the gravity segregation of Sn in casting could be removed basically, and the relationship between solid fraction of alloy mushy and size of Sn particle in ingot was s=-0.64fs+70.8.

  19. Thermodynamic and surface properties of Sb-Sn and In-Sn liquid alloys

    Indian Academy of Sciences (India)

    B C Anusionwu

    2006-08-01

    The thermodynamic properties of Sb-Sn and In-Sn liquid alloys have been studied using the quasi-chemical model for compound forming binary alloys and that for simple regular alloys. The concentration fluctuation cc(0) and the Warren-Cowley short-range order parameter (1) were determined for the whole concentration range at a temperature of 770 K. The surface tensions of these liquid alloys were determined for the whole concentration range by using energetics determined from thermodynamic calculations. In all calculations, In{Sn manifested properties very close to alloys of ideal mixing, while Sb-Sn showed properties that are asymmetric about equiatomic composition. Our results suggest that a weak complex of the form SbSn2 could be present in the Sb-Sn alloy at a temperature of about 770 K.

  20. Reactions in Electrodeposited Cu/Sn and Cu/Ni/Sn Nanoscale Multilayers for Interconnects

    Directory of Open Access Journals (Sweden)

    Pay Ying Chia

    2016-05-01

    Full Text Available Miniaturization of electronic devices has led to the development of 3D IC packages which require ultra-small-scale interconnections. Such small interconnects can be completely converted into Cu-Sn based intermetallic compounds (IMCs after reflow. In an effort to improve IMC based interconnects, an attempt is made to add Ni to Cu-Sn-based IMCs. Multilayer interconnects consisting of stacks of Cu/Sn/Cu/Sn/Cu or Cu/Ni/Sn/Ni/Sn/Cu/Ni/Sn/Ni/Cu with Ni = 35 nm, 70 nm, and 150 nm were electrodeposited sequentially using copper pyrophosphate, tin methanesulfonic, and nickel Watts baths, respectively. These multilayer interconnects were investigated under room temperature aging conditions and for solid-liquid reactions, where the samples were subjected to 250 °C reflow for 60 s and also 300 °C for 3600 s. The progress of the reaction in the multilayers was monitored by using X-ray Diffraction, Scanning Electron Microscope, and Energy dispersive X-ray Spectroscopy. FIB-milled samples were also prepared for investigation under room temperature aging conditions. Results show that by inserting a 70 nanometres thick Ni layer between copper and tin, premature reaction between Cu and Sn at room temperature can be avoided. During short reflow, the addition of Ni suppresses formation of Cu3Sn IMC. With increasing Ni thickness, Cu consumption is decreased and Ni starts acting as a barrier layer. On the other hand, during long reflow, two types of IMC were found in the Cu/Ni/Sn samples which are the (Cu,Ni6Sn5 and (Cu,Ni3Sn, respectively. Details of the reaction sequence and mechanisms are discussed.

  1. Dissolution and Interfacial Reactions of (Cu,Ni)6Sn5 Intermetallic Compound in Molten Sn-Cu-Ni Solders

    Science.gov (United States)

    Wang, Chao-hong; Lai, Wei-han; Chen, Sinn-wen

    2014-01-01

    (Cu,Ni)6Sn5 is an important intermetallic compound (IMC) in lead-free Sn-Ag-Cu solder joints on Ni substrate. The formation, growth, and microstructural evolution of (Cu,Ni)6Sn5 are closely correlated with the concentrations of Cu and Ni in the solder. This study reports the interfacial behaviors of (Cu,Ni)6Sn5 IMC (Sn-31 at.%Cu-24 at.%Ni) with various Sn-Cu, Sn-Ni, and Sn-Cu-Ni solders at 250°C. The (Cu,Ni)6Sn5 substrate remained intact for Sn-0.7 wt.%Cu solder. When the Cu concentration was decreased to 0.3 wt.%, (Cu,Ni)6Sn5 significantly dissolved into the molten solder. Moreover, (Cu,Ni)6Sn5 dissolution and (Ni,Cu)3Sn4 formation occurred simultaneously for the Sn-0.1 wt.%Ni solder. In Sn-0.5 wt.%Cu-0.2 wt.%Ni solder, many tiny (Cu,Ni)6Sn5 particulates were formed and dispersed in the solder matrix, while in Sn-0.3 wt.%Cu-0.2 wt.%Ni a lot of (Ni,Cu)3Sn4 grains were produced. Based on the local equilibrium hypothesis, these results are further discussed based on the liquid-(Cu, Ni)6Sn5-(Ni,Cu)3Sn4 tie-triangle, and the liquid apex is suggested to be very close to Sn-0.4 wt.%Cu-0.2 wt.%Ni.

  2. In situ{sup 119}Sn Moessbauer spectroscopy study of Sn-based electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Aboulaich, Abdelmaula, E-mail: abdelmaula.aboulaich@univ-mont2.fr; Robert, Florent; Lippens, Pierre Emmanuel; Aldon, Laurent; Olivier-Fourcade, Josette [Universite Montpellier II, Laboratoire des Agregats Moleculaires et Materiaux Inorganiques (UMR 5072-CNRS) (France); Willmann, Patrick [Centre National d' Etudes Spatiales (France); Jumas, Jean-Claude [Universite Montpellier II, Laboratoire des Agregats Moleculaires et Materiaux Inorganiques (UMR 5072-CNRS) (France)

    2006-01-15

    Sn-based composite materials were synthetized by a conventional melt-quenching method, and studied by X-ray diffraction, electrochemistry and in situ{sup 119}Sn Moesssbauer spectroscopy. Tin was dispersed ex situ into a matrix formed from B{sub 2}O{sub 3}:P{sub 2}O{sub 5}. XRD and {sup 119}Sn Moessbauer spectroscopy show the formation of an interface between the active species (Sn{sup 0}) and the matrix. This amorphous interface acts as a 'buffer-zone' which compensates volume changes during the tin-lithium alloy formation and avoids aggregation of tin particles.

  3. Electrochemical properties of Ti-Ni-Sn materials predicted by 119Sn Mössbauer spectroscopy

    Science.gov (United States)

    Ladam, A.; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C.; Cenac-Morthe, C.

    2016-12-01

    The electrochemical activity of TiNiSn, TiNi 2Sn and Ti 6Sn 5 compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti 6Sn 5 by ball milling. The 119Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e av]. The values of [e av] are in the region of Li-rich Li-Sn alloys for Ti 6Sn 5 and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e av] for Ti 6Sn 5 and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  4. Aperiodic SiSn/Si multilayers for thermoelectric applications

    Science.gov (United States)

    Tonkikh, A. A.; Zakharov, N. D.; Eisenschmidt, C.; Leipner, H. S.; Werner, P.

    2014-04-01

    We report on novel defect-free SiSn/Si heterostructures grown pseudomorphically on Si(001) substrates using temperature-modulated molecular beam epitaxy. This approach results in a sustainable epitaxial growth for SiSn/Si multilayers. Transmission electron microscopy and electron diffraction manifest that SiSn layers possess a diamond lattice structure. X-ray diffraction reveals up to 9.5 at% Sn in the crystal lattice of SiSn layers.

  5. Anomalous creep in Sn-rich solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon; Morris Jr., John W.; Hua, Fay

    2002-03-15

    This paper discusses the creep behavior of example Sn-rich solders that have become candidates for use in Pb-free solder joints. The specific solders discussed are Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-0.7Cu and Sn-10In-3.1Ag, used in thin joints between Cu and Ni-Au metallized pads.

  6. GRB 140606B / iPTF14bfu: Detection of shock-breakout emission from a cosmological gamma-ray burst?

    CERN Document Server

    Cano, Z; Perley, D; Kruhler, T; Margutti, R; Friis, M; Malesani, D; Jakobsson, P; Fynbo, J P U; Gorosabel, J; Hjorth, J; Sanchez-Ramirez, R; Schulze, S; Tanvir, N R; Thone, C C; Xu, D

    2015-01-01

    We present optical and near-infrared photometry of GRB 140606B ($z=0.384$), and optical photometry and spectroscopy of its associated supernova (SN). The bolometric properties of the SN are: a nickel mass of M$_{\\rm Ni}$=0.4$\\pm$0.2 M$_{\\odot}$, an ejecta mass of M$_{\\rm ej}$=5$\\pm$2 M$_{\\odot}$, and a kinetic energy of E$_{\\rm K}$=2$\\pm1\\times10^{52}$ erg. The uncertain value of M$_{\\rm Ni}$ is primarily due to the poorly constrained rest-frame extinction ($E(B-V)_{\\rm rest}$=0.16$\\pm$0.14 mag). The photospheric velocity of the SN near maximum light is $v_{\\rm ph}\\approx$20,000 km/s. The photospheric velocity and bolometric properties are fully consistent with the statistical averages determined for other GRB-SNe. However, in terms of its $\\gamma$-ray emission, GRB 140606B is an outlier of the Amati relation, and occupies the same region as low-luminosity ($ll$) and short GRBs. The $\\gamma$-ray emission in $ll$GRBs is thought to arise, at least in some events, from a shock-breakout (SBO), rather than from a ...

  7. Sn-inserted Al-induced layer exchange for large-grained GeSn thin films on insulator

    OpenAIRE

    Toko, Kaoru; Oya, Naoki; Nakata, Mitsuki; Suemasu, Takashi

    2016-01-01

    Large-grained polycrystalline GeSn layers on glass are achieved through the layer exchange between a-Ge and Sn-doped Al layers. The thicker Sn layers, inserted below Al layers, provided the faster growth velocity, resulting in the smaller grain size of the GeSn layer. Controlling the Sn thickness (10 nm) and the growth temperature (300 °C) allowed for approximately 80% (111)-oriented GeSn layer with grains having an average size of 40 μm. The lower growth temperature led to the higher Sn cont...

  8. Ag3Sn plate formation in the solidification of near-ternary eutectic Sn-Ag-Cu

    Science.gov (United States)

    Kang, Sung K.; Shih, Da-Yuan; Donald, Ny.; Henderson, W.; Gosselin, Timothy; Sarkhel, Amit; Charles Goldsmith, Ny.; Puttlitz, Karl J.; Choi, Won Kyoung

    2003-06-01

    Near-ternary eutectic Sn-Ag-Cu alloys are leading lead-free candidate solders for various applications. These alloys yield three phases upon solidification: β-Sn,Ag3Sn, and Cu6Sn5. Large, plate-like, pro-eutectic Ag3Sn structures can grow rapidly within the liquid phase, potentially adversely affecting the mechanical behavior and reducing the fatigue life of solder joints. This article reports on the formation of such plates in Sn-Ag-Cu solder balls and joints and demonstrates how large Ag3Sn plate formation can be minimized.

  9. On Mossbauer dynamics in Nb3Sn

    Indian Academy of Sciences (India)

    Ashok Razdan

    2000-06-01

    We compare the anharmonic Lamb Mossbauer factor and the -Lamb Mossbauer factor by studying the anharmonicity observed in the -factor data of Nb3Sn. We also show that this anharmonicity does not arise due to the presence of potential.

  10. The system SnSe-Bi

    Energy Technology Data Exchange (ETDEWEB)

    Alidzhanov, M.A.; Alizade, M.Z.; Aslanov, G.A.; Gurshumov, A.P.; Persakhova, A.Y.

    1986-10-01

    The authors study the system SnSe-Bi on annealed samples by methods of physicochemical analysis; x-ray phase, differential-thermal analysis, microstructural analysis, and measurements of the microhardness. It was established that the eutectic contains five mole % SnSe and melts at 260 C. A bounded region of the SnSe-based solid solutions exist, and the solubility of SnSe in bismuth was not observed. Anomalies in the temperature dependences of the thermo-emf and electrical conductivity of the solid solutions were determined by the phase transformations of tin monoselenide. The nature of the changes in the thermo-emf and the electrical conductivity as a function of the temperature is associated with the changes in the density and effective mass of the charge carriers.

  11. Theoretical study of projectile fragmentation in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at 1 GeV/nucleon

    CERN Document Server

    Imal, H; Buyukcizmeci, N; Ogul, R; Botvina, A S; Trautmann, W

    2014-01-01

    We analyze the production cross sections and isotopic distributions of projectile-like residues in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. Calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters determined previously for similar reactions at 600 MeV/nucleon. The obtained good agreement with the experiment establishes the universal properties of the excited spectator systems produced during the dynamical stage of the reaction. It is furthermore confirmed that a significant reduction of the symmetry-energy term at the freeze-out stage of reduced density and high temperature is necessary to reproduce the experimental isotope distributions. A trend of decreasing symmetry energy for large neutron-rich fragments of low excitation energy is interpreted as a nuclear-structure effect.

  12. MCNP6 Study of Fragmentation Products from 112Sn + 112Sn and 124Sn + 124Sn at 1 GeV/nucleon

    CERN Document Server

    Mashnik, Stepan G

    2013-01-01

    Isotope production cross sections from 112Sn + 112Sn and 124Sn + 124Sn reactions at 1 GeV/nucleon, which were measured recently at GSI using the heavy-ion accelerator SIS18 and the Fragment Separator (FRS), have been analyzed with the latest Los Alamos Monte-Carlo transport code MCNP6 using the LAQGSM03.03 event generator. MCNP6 reproduces reasonably well all the measured cross sections. Comparison of the MCNP6 results with the measured data and with calculations by a modification of the Los Alamos version of the Quark-Gluon String Model allowing for multifragmentation processes in the framework of the Statistical Multifragmentation Model (SMM) by Botvina and coauthors, as realized in the code LAQGSM03.S1, does not suggest unambiguous evidence of a multifragmentation signature.

  13. SN 1054: A pulsar-powered supernova?

    Science.gov (United States)

    Li, Shao-Ze; Yu, Yun-Wei; Huang, Yan

    2015-11-01

    The famous ancient supernova SN 1054 could have been too bright to be explained in the “standard” radioactive-powered supernova scenario. As an alternative attempt, we demonstrate that the spin-down of the newly born Crab pulsar could provide a sufficient energy supply to make SN 1054 visible at daytime for 23 days and at night for 653 days, where a one-zone semi-analytical model is employed. Our results indicate that SN 1054 could be a “normal” cousin of magnetar-powered superluminous supernovae. Therefore, SN 1054-like supernovae could be a probe to uncover the properties of newly born neutron stars, which provide initial conditions for studies on neutron star evolutions.

  14. Optical Characterization of Si-Based Ge1- x Sn x Alloys with Sn Compositions up to 12%

    Science.gov (United States)

    Al-Kabi, Sattar; Ghetmiri, Seyed Amir; Margetis, Joe; Du, Wei; Mosleh, Aboozar; Alher, Murtadha; Dou, Wei; Grant, Joshua M.; Sun, Greg; Soref, Richard A.; Tolle, John; Li, Baohua; Mortazavi, Mansour; Naseem, Hameed A.; Yu, Shui-Qing

    2016-04-01

    Optical properties of germanium tin (Ge1- x Sn x ) alloys have been comprehensively studied with Sn compositions from 0 (Ge) to 12%. Raman spectra of the GeSn samples with various Sn compositions were measured. The room temperature photoluminescence (PL) spectra show a gradual shift of emission peaks towards longer wavelength as Sn composition increases. Temperature dependent PL shows the PL intensity variation along with the temperature change, which reveals the indirectness or directness of the bandgap of the material. As temperature decreases, the PL intensity decreases with Sn composition less than 8%, indicating the indirect bandgap Ge1- x Sn x ; while the PL intensity increases with Sn composition higher than 10%, implying the direct bandgap Ge1- x Sn x . Moreover, the PL study of n-doped samples shows bandgap narrowing compared to the unintentionally (Boron) doped thin film with similar Sn compositions due to the doping.

  15. Advances in $Nb_{3}Sn$ performance

    CERN Document Server

    Godeke, A

    2009-01-01

    Nb3Sn wires with non-Cu critical current densities (Jc) that surpass 3 kAmm−2 at 12 T and 4.2 K are commercially available in piece lengths longer than 10 km. Acceleratortype magnets that utilize these conductors have achieved record magnetic fields. This article summarizes key developments in the last decade that have led to these significant improvements in the performance of Nb3Sn wires.

  16. Advances in Nb3Sn Performance

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, Arno

    2008-05-19

    Nb{sub 3}Sn wires with non-Cu critical current densities (J{sub c}) that surpass 3 kAmm{sup -2} at 12 T and 4.2 K are commercially available in piece lengths longer than 10 km. Accelerator-type magnets that utilize these conductors have achieved record magnetic fields. This article summarizes key developments in the last decade that have led to these significant improvements in the performance of Nb{sub 3}Sn wires.

  17. SALT spectroscopic classification of PS16atu (SN 2016atv) as a type-Ia supernova after maximum light

    Science.gov (United States)

    Jha, S. W.; Pan, Y.-C.; Foley, R. J.; Rest, A.; Scolnic, D.; Kotze, M.

    2016-03-01

    We obtained SALT (+RSS) spectroscopy of PS16atu (SN 2016atv) on 2016 Mar 10.1 UT, covering the wavelength range 350-920 nm. Cross-correlation of the spectrum with a template library using SNID (Blondin & Tonry 2007, ApJ, 666, 1024) shows PS16atu is a type-Ia supernova approximately a week past maximum light.

  18. Explosion Calculations of SN1087

    Science.gov (United States)

    Wooden, Diane H.; Morrison, David (Technical Monitor)

    1994-01-01

    Explosion calculations of SNT1987A generate pictures of Rayleigh-Taylor fingers of radioactive Ni-56 which are boosted to velocities of several thousand km/s. From the KAO observations of the mid-IR iron lines, a picture of the iron in the ejecta emerges which is consistent with the "frothy iron fingers" having expanded to fill about 50% of the metal-rich volume of the ejecta. The ratio of the nickel line intensities yields a high ionization fraction of greater than or equal to 0.9 in the volume associated with the iron-group elements at day 415, before dust condenses in the ejecta. From the KAO observations of the dust's thermal emission, it is deduced that when the grains condense their infrared radiation is trapped, their apparent opacity is gray, and they have a surface area filling factor of about 50%. The dust emission from SN1987A is featureless: no 9.7 micrometer silicate feature, nor PAH features, nor dust emission features of any kind are seen at any time. The total dust opacity increases with time even though the surface area filling factor and the dust/gas ratio remain constant. This suggests that the dust forms along coherent structures which can maintain their radial line-of-sight opacities, i.e., along fat fingers. The coincidence of the filling factor of the dust and the filling factor of the iron strongly suggests that the dust condenses within the iron, and therefore the dust is iron-rich. It only takes approximately 4 x 10(exp -4) solar mass of dust for the ejecta to be optically thick out to approximately 100 micrometers; a lower limit of 4 x 10(exp -4) solar mass of condensed grains exists in the metal-rich volume, but much more dust could be present. The episode of dust formation started at about 530 days and proceeded rapidly, so that by 600 days 45% of the bolometric luminosity was being emitted in the IR; by 775 days, 86% of the bolometric luminosity was being reradiated by the dust. Measurements of the bolometric luminosity of SN1987A from

  19. The Nature of SN 1961V

    CERN Document Server

    Chu, Y H; Stockdale, C J; Rupen, M P; Cowan, J J; Teare, S W; Chu, You-Hua; Gruendl, Robert A.; Stockdale, Christopher J.; Rupen, Michael P.; Cowan, John J.; Teare, Scott W.

    2004-01-01

    The nature of SN 1961V has been uncertain. Its peculiar optical light curve and slow expansion velocity are similar to those of super-outbursts of luminous blue variables (LBVs), but its nonthermal radio spectral index and declining radio luminosity are consistent with decades-old supernovae (SNe). We have obtained Hubble Space Telescope STIS images and spectra of the stars in the vicinity of SN 1961V, and find Object 7 identified by Filippenko et al. to be the closest to the optical and radio positions of SN 1961V. Object 7 is the only point source detected in our STIS spectra and only its H-alpha emission is detected; it cannot be the SN or its remnant because of the absence of forbidden lines. While the H-alpha line profile of Object 7 is remarkably similar to that of eta Car, the blue color (similar to an A2Ib supergiant) and lack of appreciable variability are unlike known post-outburst LBVs. We have also obtained Very Long Baseline Array (VLBA) observations of SN 1961V at 18 cm. The non-detection of SN ...

  20. DAO Spectroscopic classification of SN 2016bir in SDSS J131405.16+335510.1

    Science.gov (United States)

    Balam, D. D.; Graham, M. L.

    2016-04-01

    A noisy spectrum was obtained of SN 2016bir (ATEL #8857) on Apr. 10.36 UT using the 1.82-m Plaskett telescope (National Research Council of Canada) covering the range 405-710 nm (resolution 0.32 nm). Cross-correlation with a template library using SNID (Blondin & Tonry 2007, ApJ, 666, 1024) shows 2016bir to most resemble the spectrum of a type-Ib supernova approximately 1 week pre-maximum light.

  1. Supernova SN 1006 in two historic Yemeni reports

    CERN Document Server

    Rada, Wafiq

    2015-01-01

    We present two Arabic texts of historic observations of supernova SN 1006 from Yemen as reported by al-Yamani and Ibn al-Dayba (14th to 16th century AD). An English translation of the report by the latter was given before (Stephenson & Green 2002), but the original Arabic text was not yet published. In addition, we present for the first time the earlier report, also from Yemen, namely by al-Yamani in its original Arabic and with our English translation. It is quite obvious that the report by Ibn al-Dayba is based on the report by al-Yamani (or a common source), but the earlier report by al-Yamani is more detailed and in better (Arabic) language. We discuss in detail the dating of these observations. The most striking difference to other reports about SN 1006 is the apparent early discovery in Yemen in the evening of 15th of Rajab of the year 396h (i.e. AD 1006 Apr 17 \\pm 2 on the Julian calendar), as reported by both al-Yamani and Ibn al-Dayba. i.e. about 1.5 weeks earlier than the otherwise earliest know...

  2. SN 2009kn - The Twin of the Type IIn SN 1994W

    CERN Document Server

    Kankare, E; Bufano, F; Spyromilio, J; Mattila, S; Chugai, N N; Lundqvist, P; Pastorello, A; Kotak, R; Benetti, S; Botticella, M-T; Cumming, R J; Fransson, C; Fraser, M; Leloudas, G; Miluzio, M; Sollerman, J; Stritzinger, M; Turatto, M; Valenti, S

    2012-01-01

    We present an optical and near-infrared photometric and spectroscopic study of supernova (SN) 2009kn spanning ~1.5 yr from the discovery. The optical spectra are dominated by the narrow (FWHM ~1000 km s^-1) Balmer lines distinctive of a Type IIn SN with P-Cygni profiles. Contrarily the photometric evolution resembles more that of a Type IIP SN with a large drop in luminosity at the end of the plateau phase. These characteristics are similar to those of SN 1994W, whose nature has been explained with two different models with different approaches. The well-sampled dataset on SN 2009kn offers the possibility to test these models, both in the case of SN 2009kn and SN 1994W. We associate the narrow P-Cygni lines with a swept-up shell composed of circumstellar matter and SN ejecta. The broad emission line wings, seen during the plateau phase arise from internal electron scattering in this shell. The slope of the light curve after the post-plateau drop is fairly consistent with that expected from the radioactive dec...

  3. 2-weekly docetaxel: issues for clinical practice

    Science.gov (United States)

    Massari, F; Maines, F; Bria, E; Galligioni, E; Caffo, O; Tortora, G

    2015-01-01

    In the phase III trial comparing 2 docetaxel schedules (3-weekly versus 2-weekly) as first-line chemotherapy for CRPC, recently published in The Lancet Oncology, fewer serious adverse events, particularly hematologic toxicities, and longer times on treatment, in favor of the 2-weekly regimen are reported.1,2,3 PMID:25456569

  4. Understanding Infidelity: An Interview with Gerald Weeks

    Science.gov (United States)

    Smith, Travis

    2011-01-01

    In this interview, Gerald Weeks shares his expertise on the topic of infidelity and couples counseling. Dr. Weeks defines infidelity, presents assessment strategies for treating the issue of infidelity, and discusses an intersystemic model for infidelity treatment when counseling couples. Dr. Weeks also provides insight into common mistakes made…

  5. 75 FR 62307 - Fire Prevention Week, 2010

    Science.gov (United States)

    2010-10-08

    ... Documents#0;#0; ] Proclamation 8577 of October 1, 2010 Fire Prevention Week, 2010 By the President of the United States of America A Proclamation During Fire Prevention Week, we reaffirm the importance of fire... consequences. Fire Prevention Week also calls our attention to the lifesaving work our firefighters perform...

  6. Effect of Sn:Zn Ratio on Corrosion Behavior of Mg-aSn-bZn Extrusions

    Science.gov (United States)

    Yim, Chang Dong; Woo, Sang Kyu; You, Bong Sun

    The effect of Sn:Zn ratio on corrosion behavior of magnesium alloys containing Sn and Zn was evaluated systematically by potentiodynamic polarization and immersion tests. The hydrogen evolution rate during cathodic polarization and the average corrosion rate measured by immersion test increased with increasing Sn content and Sn:Zn ratio. The changes of fraction of second phase with more positive corrosion potential and solute contents in the matrix phase were responsible for the change of corrosion behavior according to Sn content and Sn:Zn ratio. Mg2Sn particle accelerated the corrosion by formation of micro-galvanic cell, which resulted in faster corrosion rates of Mg-5Sn-xZn alloys than those of Mg-2Sn-xZn alloys. The increase of Zn in the matrix was harmful to the corrosion resistance because Zn accelerated the hydrogen evolution although ZnO was beneficial to the passivity of surface film.

  7. Creep performance of Zr-1Nb-0.75Sn-0.1Fe cladding tubes with optimized Sn content

    Science.gov (United States)

    Kim, Won Nyeon; Choi, Yong; Hong, Sun Ig

    2014-12-01

    Creep properties of stress-relieved Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content were studied. Zr-1Nb-0.75Sn-0.1Fe alloy was found to have stress exponents of 6-7, independent of stress level, unlike Zr-1Nb-1Sn-0.1Fe alloy, in which the transition of stress exponent with increase of stress was observed. The constancy of stress exponent, without the transition observed in Zr-1Nb-0.75Sn-0.1Fe alloy with lower Sn content, is associated with the decrease of Sn atoms. The activation energies for creep deformation were calculated to be between 210 and 260 kJ/mol for the Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content. The slightly smaller creep activation energy in Zr-1Nb-0.75Sn-0.1Fe, compared with that of Zr-1Nb-1Sn-0.1Fe alloy, is thought to be attributed to the lower Sn content. The creep data obtained at different temperatures and stress fell close to a single line, suggesting the creep life of Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content is well expressed by the Larson-Miller Parameter.

  8. Chemistry, growth kinetics, and epitaxial stabilization of Sn2+ in Sn-doped SrTiO3 using (CH36Sn2 tin precursor

    Directory of Open Access Journals (Sweden)

    Tianqi Wang

    2016-12-01

    Full Text Available PbTiO3-based ferroelectrics have impressive electroactive properties, originating from the Pb2+ 6s2 electron lone-pair, which cause large elastic distortion and electric polarization due to cooperative pseudo Jahn-Teller effect. Recently, tin-based perovskite oxide (SnTiO3 containing Sn2+ and a chemistry similar to that of the 6s2 lone-pair has been identified as a thermally stable, environmentally friendly substitute for PbTiO3-based ferroelectrics. However experimental attempts to stabilize Sn2+ on the A-site of perovskite ATiO3 have so far failed. In this work, we report on the growth of atomically smooth, epitaxial, and coherent Sn-alloyed SrTiO3 films on SrTiO3 (001 substrates using a hybrid molecular beam epitaxy approach. With increasing Sn concentration, the out-of-plane lattice parameter first increases in accordance with the Vegard’s law and then decreases for Sn(Sr+Ti+Sn at. % ratio > 0.1 due to the incorporation of Sn2+ at the A-site. Using a combination of high-resolution X-ray photoelectron spectroscopy and density functional calculations, we show that while majority of Sn is on the B-site, there is a quantitatively unknown fraction of Sn being consistent with the A-site occupancy making SrTiO3 polar. A relaxor-like ferroelectric local distortion with monoclinic symmetry, induced by A-site Sn2+, was observed in Sn-doped SrTiO3 with Sn(Sr+Ti+Sn at. % ratio = 0.1 using optical second harmonic generation measurements. The role of growth kinetics on the stability of Sn2+ in SrTiO3 is discussed.

  9. Chemistry, growth kinetics, and epitaxial stabilization of Sn2+ in Sn-doped SrTiO3 using (CH3)6Sn2 tin precursor

    Science.gov (United States)

    Wang, Tianqi; Pitike, Krishna Chaitanya; Yuan, Yakun; Nakhmanson, Serge M.; Gopalan, Venkatraman; Jalan, Bharat

    2016-12-01

    PbTiO3-based ferroelectrics have impressive electroactive properties, originating from the Pb2+ 6s2 electron lone-pair, which cause large elastic distortion and electric polarization due to cooperative pseudo Jahn-Teller effect. Recently, tin-based perovskite oxide (SnTiO3) containing Sn2+ and a chemistry similar to that of the 6s2 lone-pair has been identified as a thermally stable, environmentally friendly substitute for PbTiO3-based ferroelectrics. However experimental attempts to stabilize Sn2+ on the A-site of perovskite ATiO3 have so far failed. In this work, we report on the growth of atomically smooth, epitaxial, and coherent Sn-alloyed SrTiO3 films on SrTiO3 (001) substrates using a hybrid molecular beam epitaxy approach. With increasing Sn concentration, the out-of-plane lattice parameter first increases in accordance with the Vegard's law and then decreases for Sn(Sr+Ti+Sn/) at. % ratio > 0.1 due to the incorporation of Sn2+ at the A-site. Using a combination of high-resolution X-ray photoelectron spectroscopy and density functional calculations, we show that while majority of Sn is on the B-site, there is a quantitatively unknown fraction of Sn being consistent with the A-site occupancy making SrTiO3 polar. A relaxor-like ferroelectric local distortion with monoclinic symmetry, induced by A-site Sn2+, was observed in Sn-doped SrTiO3 with Sn(Sr+Ti+Sn/) at. % ratio = 0.1 using optical second harmonic generation measurements. The role of growth kinetics on the stability of Sn2+ in SrTiO3 is discussed.

  10. GRB 080319b and SN1054 .

    Science.gov (United States)

    Martocchia, A.; Polcaro, V. F.

    A typical SN Type IIp model can fit the SN1054 explosion light curve when data coming from European sources are also considered. Though a detailed study of these texts reveals a number of problems in their precise datation, it is likely that they actually describe the observation of an unusual celestial event which occurred in a day near to the one of Pope Leo IX's death (19 April, 1054). In particular, they seem to show that a very bright transient celestial phenomenon, lasting about 30 min, was observed. We already suggested that this Medieval testimonies were due to a very short and bright light flash in the first phase of the SN precursor collapse. The discovery of a similar flash in GRB 080319b brought us to consider this hypothesis more deeply. We thus scaled the intensity of the GRB 080319b to a distance of 1.83 kpc, in order to evaluate the intensity of a similar flash in the SN1054. We then took this value as input of the atmospheric optical effects simulation code \\textit{HaloSim3}, using the point-like source option for the dates and sites reported in European texts connected with the SN1054 event, and in various atmospheric conditions. The results are remarkably similar to the effects reported in Medieval chronicles.

  11. Study of a SiGeSn/GeSn/SiGeSn structure toward direct bandgap type-I quantum well for all group-IV optoelectronics.

    Science.gov (United States)

    Ghetmiri, Seyed Amir; Zhou, Yiyin; Margetis, Joe; Al-Kabi, Sattar; Dou, Wei; Mosleh, Aboozar; Du, Wei; Kuchuk, Andrian; Liu, Jifeng; Sun, Greg; Soref, Richard A; Tolle, John; Naseem, Hameed A; Li, Baohua; Mortazavi, Mansour; Yu, Shui-Qing

    2017-02-01

    A SiGeSn/GeSn/SiGeSn single quantum well structure was grown using an industry standard chemical vapor deposition reactor with low-cost commercially available precursors. The material characterization revealed the precisely controlled material growth process. Temperature-dependent photoluminescence spectra were correlated with band structure calculation for a structure accurately determined by high-resolution x-ray diffraction and transmission electron microscopy. Based on the result, a systematic study of SiGeSn and GeSn bandgap energy separation and barrier heights versus material compositions and strain was conducted, leading to a practical design of a type-I direct bandgap quantum well.

  12. Experimental Investigation of the Ti-Nb-Sn Isothermal Section at 1173 K

    Directory of Open Access Journals (Sweden)

    Jianli Wang

    2016-03-01

    Full Text Available Isothermal section of Ti-Nb-Sn at 1173 K was experimentally studied by back-scattered electron, electron probe microanalysis and X-ray diffraction analysis. Solid solution phase β(Ti, Nb, liquid Sn and eight intermetallic compounds Ti3Sn, Ti2Sn, Ti5Sn3, Ti6Sn5, Nb6Sn5, Nb3Sn, Ti3Nb2Sn2 and Ti3NbSn coexisted. Four ternary phase regions Ti3Sn + Ti3NbSn + β(Ti, Nb, Ti3NbSn + Ti3Nb3Sn2 + Ti3Sn, Ti2Sn + Ti3Sn + Ti3Nb3Sn2 and Ti6Sn5 + Ti3Nb3Sn2 + Nb3Sn were experimented. In addition, the proper composition range of the single phase was suggested. All the detected Ti-Sn and Nb-Sn compounds have a remarkable solubility along the isoconcentration of Sn. β(Ti, Nb has a relatively large solution while liquid Sn has a little in the isothermal section.

  13. Raman spectral shift versus strain and composition in GeSn layers with: 6 to 15% Sn contents

    OpenAIRE

    Gassenq, A.; Milord, L.; Aubin, J.; Pauc, N.; Guilloy, K.; Rothman, J.; Rouchon, D.; Chelnokov, A.; Hartmann, J.M.; Reboud, V.; Calvo, V.

    2017-01-01

    GeSn alloys are the subject of intense research activities as these group IV semiconductors present direct bandgap behaviors for high Sn contents. Today, the control of strain becomes an important challenge to improve GeSn devices. Strain micro-measurements are usually performed by Raman spectroscopy. However, different relationships linking the Raman spectral shifts to the built-in strain can be found in the literature. They were deduced from studies on low Sn content GeSn layers (i.e. xSn

  14. Ultraviolet emission from low resistance Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires

    Directory of Open Access Journals (Sweden)

    E. Karageorgou

    2014-11-01

    Full Text Available SnO2 and Sn:In2O3 nanowires were grown on Si(001, and p-n junctions were fabricated in contact with p-type Cu2S which exhibited rectifying current–voltage characteristics. Core-shell Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires were obtained by depositing copper and post-growth processing under H2S between 100 and 500 °C. These consist mainly of tetragonal rutile SnO2 and cubic bixbyite In2O3. We observe photoluminescence at 3.65 eV corresponding to band edge emission from SnO2 quantum dots in the Cu2SnS3/SnO2 nanowires due to electrostatic confinement. The Cu2SnS3/SnO2 nanowires assemblies had resistances of 100 Ω similar to CuInS2/In2O3 nanowires which exhibited photoluminescence at 3.0 eV.

  15. Interplay between relaxation and Sn segregation during thermal annealing of GeSn strained layers

    Science.gov (United States)

    Comrie, C. M.; Mtshali, C. B.; Sechogela, P. T.; Santos, N. M.; van Stiphout, K.; Loo, R.; Vandervorst, W.; Vantomme, A.

    2016-10-01

    The effect of thermal annealing on epitaxial GeSn (6.5% Sn) strained layers grown on Ge-buffered Si(100) wafers has been investigated using Rutherford backscattering spectrometry and X-ray diffraction to unambiguously determine the Sn substitutional content as well as the elastic strain in the layers. Vacuum annealing at temperatures below 400 °C for 20 min has no noticeable effect on the strain in the epitaxial layers. Once the temperature was raised above 400 °C, however, relaxation of the layer sets in and the GeSn layer has essentially completely relaxed following a 20 min anneal at 650 °C. Using Rutherford backscattering and channelling spectrometry to provide compositional information as a function of depth enables one to monitor the effect of the thermal anneal on the Sn distribution throughout the layer, and also to directly extract their substitutional fraction (i.e., their solubility in the lattice). The results obtained show that when the relaxation initially sets in both the Ge and the Sn remain firmly bound in substitutional lattice sites and it is only around 600 °C, and after substantial relaxation has taken place, that Sn is finally expelled from lattice sites and diffuses to the surface of the sample.

  16. Primary solidification phases of the Sn-rich Sn-Ag-Cu-Ni quaternary system

    Science.gov (United States)

    Chang, Cheng-An; Chen, Sinn-Wen; Chiu, Chen-Nan; Huang, Yu-Chih

    2005-08-01

    The eutectic and near-eutectic Sn-Ag-Cu solders are the most promising lead-free solders, and nickel is frequently used as the barrier layer material. Nickel dissolves into the molten Sn-Ag-Ni alloy during the soldering process, and the ternary solder becomes a Sn-Ag-Cu-Ni quaternary melt near the nickel substrate. Liquidus projection is the projection of the liquidus trough and it delineates the boundaries of various primary solidification phases. Information of liquidus projection is helpful for understanding the alloys’ solidification behavior. This study prepared the Sn-Ag-Cu-Ni alloys of various compositions at the Sn-rich corner. The alloys were melted at higher temperatures and solidified in air. The solidified alloys were metallographically examined to determine the phases formed, especially the primary solidification phases. No ternary or quaternary compounds were found. The knowledge of the primary solidification phases, phase formation sequences, and reaction temperatures determined in this study were put together with all of the available liquidus projections of the constituent ternary systems to determine the primary solidification phases of the quaternary Sn-Ag-Cu-Ni system at the Sn-rich corner.

  17. SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova

    CERN Document Server

    Kelly, P L; Selsing, J; Foley, R J; Hjorth, J; Rodney, S A; Christensen, L; Strolger, L -G; Filippenko, A V; Treu, T; Steidel, C C; Strom, A; Riess, A G; Zitrin, A; Schmidt, K B; Bradac, M; Jha, S W; Graham, M L; McCully, C; Graur, O; Weiner, B J; Silverman, J M

    2015-01-01

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in Fall 2014. The HST light curve of SN Refsdal matches the distinctive, slowly rising light curves of SN 1987A-like supernovae (SNe), and we find strong evidence for a broad H-alpha P-Cygni profile in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H-alpha absorption. From the grism spectrum, we measure an H-alpha expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H-alpha emission of the WFC3 and X-shooter spectra, separated by ~2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other exam...

  18. The Supernova Impostor SN 2010da

    Science.gov (United States)

    Binder, Breanna A.; Williams, Benjamin F.; Kong, Albert K. H.; Plucinsky, Paul P.; Gaetz, Terrance J.; Skillman, Evan D.; Dolphin, Andrew E.

    2016-01-01

    Supernova impostors are optical transients that, despite being assigned a supernova designation, do not signal the death of a massive star or accreting white dwarf. Instead, many impostors are thought to be major eruptions from luminous blue variables. Although the physical cause of these eruptions is still debated, tidal interactions from a binary companion has recently gained traction as a possible explanation for observations of some supernova impostors. In this talk, I will discuss the particularly interesting impostor SN 2010da, which exhibits high-luminosity, variable X-ray emission. The X-ray emission is consistent with accretion onto a neutron star, making SN 2010da a likely high mass X-ray binary in addition to a supernova impostor. SN 2010da is a unique laboratory for understanding both binary interactions as drivers of massive star eruptions and the evolutionary processes that create high mass X-ray binaries.

  19. The Continuing Fall of SN 1987A

    Science.gov (United States)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Danziger, John; Frank, Kari; Gehrz, Robert; Park, Sangwook; Woodward, Charles

    2016-08-01

    We propose to use a total of 0.8 hr to obtain 3.6 and 4.5 micron photometry of SNR 1987A at four final epochs between 10900 and 11500 days after the explosion. SN 1987A has been monitored at approximately 6 month intervals throughout the Spitzer mission. The latest IRAC data clearly show that at 3.6 and 4.5 micron, the SN emission has peaked and is now in decline. Continued observation of SN 1987A will allow us to track the decline as the blast wave moves completely past the equatorial ring (ER). The rate at which new dust is swept up should be dropping to zero, and as the presently swept up dust is gradually destroyed (or cools) the emission should continue to fade. The dust traced at these wavelengths is thought to be collisionally-heated by the SN blast wave that also gives rise to the soft X-ray emission from the ER. Early in the mission, the intensity of the mid-IR emission (24 micron) was generally well correlated with that of the X-ray emission. However, the 3.6 and 4.5 micron emission are no longer tracking the brightness of the soft X-ray emission. These differences could stem from a variety of causes, including the sputtering of the dust or changes in the morphology of the ER. Ongoing X-ray observations of the remnant are taking place. Supplementing these with IR observations is essential for determining the spatial distribution, nature, and evolution of this hot dust component. Additionally, the observations may still reveal the appearance of a new emission component from the SN ejecta which is currently interacting with the reverse shock. These observations will complete the record of Spitzer's observations of SN 1987A, spanning more than 15 years from launch to end of mission.

  20. Origin of the SN2 benzylic effect.

    Science.gov (United States)

    Galabov, Boris; Nikolova, Valia; Wilke, Jeremiah J; Schaefer, Henry F; Allen, Wesley D

    2008-07-30

    The S N2 identity exchange reactions of the fluoride ion with benzyl fluoride and 10 para-substituted derivatives (RC6H 4CH 2F, R = CH3, OH, OCH 3, NH2, F, Cl, CCH, CN, COF, and NO2) have been investigated by both rigorous ab initio methods and carefully calibrated density functional theory. Groundbreaking focal-point computations were executed for the C6H5CH 2F + F (-) and C 6H 5CH2Cl + Cl (-) SN2 reactions at the highest possible levels of electronic structure theory, employing complete basis set (CBS) extrapolations of aug-cc-pV XZ (X = 2-5) Hartree-Fock and MP2 energies, and including higher-order electron correlation via CCSD/aug-cc-pVQZ and CCSD(T)/aug-cc-pVTZ coupled cluster wave functions. Strong linear dependences are found between the computed electrostatic potential at the reaction-center carbon atom and the effective SN2 activation energies within the series of para-substituted benzyl fluorides. An activation strain energy decomposition indicates that the SN2 reactivity of these benzylic compounds is governed by the intrinsic electrostatic interaction between the reacting fragments. The delocalization of nucleophilic charge into the aromatic ring in the SN2 transition states is quite limited and should not be considered the origin of benzylic acceleration of SN2 reactions. Our rigorous focal-point computations validate the benzylic effect by establishing SN2 barriers for (F (-), Cl (-)) identity exchange in (C6H5CH2F, C6H 5CH2Cl) that are lower than those of (CH3F, CH3Cl) by (3.8, 1.6) kcal mol (-1), in order.

  1. Microstructure evolution of directionally solidified Sn-16%Sb hyperperitectic alloy

    Institute of Scientific and Technical Information of China (English)

    Hu Xiaowu; Li Shuangming; Liu Lin; Fu Hengzhi

    2008-01-01

    The directionally solidified microstructure of Sn-16%Sb hyperperitectic alloy has been investigated at various solidification rates using a high-thermal gradient directional solidification apparatus. The results indicate that the solidification microstructure consists of hard primary intermetallic SnSb phase embedded in a matrix of soft peritectic β-Sn phase. The primary SnSb phase exhibits faceted growth with tetragonal or trigonal shapes. At the same time, the primary SnSb phase is refined with an increase in the solidification rate and dispersed more uniformly in the matrix of β-Sn phase. The volume fraction of the SnSb phase firstly decreases and then increases when the solidification rate increases in directional solidification of Sn-16%Sb hyperperitectic alloy.

  2. Electronic Structure, Oxidation State of Sn, and Chemical Stability of Photovoltaic Perovskite Variant Cs2SnI6

    CERN Document Server

    Xiao, Zewen; Zhang, Xiao; Zhou, Yuanyuan; Hosono, Hideo; Kamiya, Toshio

    2015-01-01

    Cs2SnI6, a variant of perovskite CsSnI3, is expected for a photovoltaic material. Based on a simple ionic model, it is expected that Cs2SnI6 is composed of Cs+, I-, and Sn4+ ions and that the band gap is primarily made of occupied I- 5p6 valence band maximum (VBM) and unoccupied Sn4+ 5s conduction band minimum (CBM) similar to SnO2. In this work, we performed density functional theory (DFT) calculations and revealed that the real charge state of the Sn ion in this compound is +2 similar to CsSnI3. This is due to strong covalent nature between the I ion and the Sn ion, the VBM consists of I 5p - I 5p antibonding states, and the CBM of I 5p - Sn 5s antibonding states. The +2 oxidation state of Sn is realized by the apparent charge state of I-2/3, because the I 5p - Sn 5s antibonding states form the unoccupied CBM and apparently 1/18 of the I 5p orbitals are unoccupied. These results are further supported by comparing chemical bonding analyses with those of related compounds. The chemical stability of the Cs2SnI...

  3. Aluminum-stabilized NB3SN superconductor

    Science.gov (United States)

    Scanlan, Ronald M.

    1988-01-01

    An aluminum-stabilized Nb.sub.3 Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb.sub.3 Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.

  4. SN 1987A - a linear polarimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, M.; Clocchiatti, A.; Benvenuto, O.G.; Feinstein, C.; Marraco, H.G.

    1988-11-01

    Multicolor linear polarimetric observations of SN 1987A have been obtained between February 28 and April 29, 1987. The intrinsic polarization was shown to decrease at a constant position angle of 27 deg during the first month after the explosion, and 30 days after the explosion the polarization began to grown in the V, R, and I filters at a different position angle. A model to interpret this behavior is proposed. Results are presented for the expansion of the outer layers of the SN and the evolution of the photospheric density. 28 references.

  5. Anomalous thermoelectric power behaviour in PrSn 3 and NdSn 3

    Science.gov (United States)

    Kletowski, Z.

    2006-03-01

    Results of the thermoelectric power (TEP) measurements done on monocrystalline samples of RESn 3 compounds (RE=La, Pr, Nd, and Gd) are presented for the temperature range of 5.5-300 K. It was found that the TEP is positive and weakly temperature dependent at temperatures T>100 K. For T<100 K pronounced anomalies have been observed for the PrSn 3 and the NdSn 3 compounds in the vicinity of 10 K.We argue that the Kondo and crystal field effects cause these anomalies. A shape of the TEP anomaly found for PrSn 3 resembles very much that observed in the electrical resistivity.

  6. Weierstrass Type Representation of Willmore Surfaces in Sn

    Institute of Scientific and Technical Information of China (English)

    Qiao Ling XIA; Yi Bing SHEN

    2004-01-01

    In this paper, we reformulate the Euler-Lagrange equations of Willmore surfaces in Sn as the flatness of a family of certain loop algebra-valued 1-forms. Therefore we can give the Weierstrass type representation of conformal Willmore surfaces. We also discuss the relations between conformal Willmore surfaces in Sn and minimal surfaces in constant curvature spaces Sn, Rn, Hn, and prove that some special Willmore surfaces can be derived from minimal surfaces in Sn, Rn, Hn.

  7. Tin (Sn) for enhancing performance in silicon CMOS

    KAUST Repository

    Hussain, Aftab M.

    2013-10-01

    We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

  8. OEO SRB Weekly Workload Status Report

    Data.gov (United States)

    Social Security Administration — Weekly reports of workloads processed in the Security Records Branch in Boyers, PA. Reports on quantities of work received, processed, pending and average processing...

  9. Gamma bandgap determination in pseudomorphic GeSn layers grown on Ge with up to 15% Sn content

    Science.gov (United States)

    Gassenq, A.; Milord, L.; Aubin, J.; Guilloy, K.; Tardif, S.; Pauc, N.; Rothman, J.; Chelnokov, A.; Hartmann, J. M.; Reboud, V.; Calvo, V.

    2016-12-01

    Adding Tin (Sn) to Germanium (Ge) can turn it into a direct bandgap group IV semiconductor emitting in the mid-infrared wavelength range. Several approaches are currently being investigated to improve the GeSn devices. It has been theoretically predicted that the strain can improve their optical properties. However, the impact of strain on band parameters has not yet been measured for really high Sn contents (i.e., above 11%). In this work, we have used the photocurrent and photoluminescence spectroscopy to measure the gamma bandgap in compressively strained GeSn layers grown on Ge buffers. A good agreement is found with the modeling and the literature. We show here that the conventional GeSn deformation potentials used in the literature for smaller Sn contents can be applied up to 15% Sn. This gives a better understanding of strained-GeSn for future laser designs.

  10. Sputtering deposition of P-type SnO films with SnO₂ target in hydrogen-containing atmosphere.

    Science.gov (United States)

    Hsu, Po-Ching; Hsu, Chao-Jui; Chang, Ching-Hsiang; Tsai, Shiao-Po; Chen, Wei-Chung; Hsieh, Hsing-Hung; Wu, Chung-Chih

    2014-08-27

    In this work, we had investigated sputtering deposition of p-type SnO using the widely used and robust SnO2 target in a hydrogen-containing reducing atmosphere. The effects of the hydrogen-containing sputtering gas on structures, compositions, optical, and electrical properties of deposited SnOx films were studied. Results show that polycrystalline and SnO-dominant films could be readily obtained by carefully controlling the hydrogen gas ratio in the sputtering gas and the extent of reduction reaction. P-type conductivity was unambiguously observed for SnO-dominant films with traceable Sn components, exhibiting a p-type Hall mobility of up to ∼3 cm(2) V(-1) s(-1). P-type SnO thin-film transistors using such SnO-dominant films were also demonstrated.

  11. Raman spectral shift versus strain and composition in GeSn layers with 6%-15% Sn content

    Science.gov (United States)

    Gassenq, A.; Milord, L.; Aubin, J.; Pauc, N.; Guilloy, K.; Rothman, J.; Rouchon, D.; Chelnokov, A.; Hartmann, J. M.; Reboud, V.; Calvo, V.

    2017-03-01

    GeSn alloys are the subject of intense research activities as these group IV semiconductors present direct bandgap behaviors for high Sn contents. Today, the control of strain becomes an important challenge to improve GeSn devices. Strain micro-measurements are usually performed by Raman spectroscopy. However, different relationships linking the Raman spectral shifts to the built-in strain can be found in the literature. They were deduced from studies on low Sn content GeSn layers (i.e., xSn contributions of strain and chemical composition on the Ge-Ge Raman spectral shift. We have shown that the GeSn Raman-strain coefficient for high Sn contents is higher compared with that for pure Ge.

  12. Highly ionized region surrounding SN Refsdal revealed by MUSE

    NARCIS (Netherlands)

    Karman, W.; Grillo, C.; Balestra, I.; Rosati, P.; Caputi, K. I.; Di Teodoro, E.; Fraternali, F.; Gavazzi, R.; Mercurio, A.; Prochaska, J. X.; Rodney, S.; Treu, T.

    2016-01-01

    Supernova (SN) Refsdal is the first multiply imaged, highly magnified, and spatially resolved SN ever observed. The SN exploded in a highly magnified spiral galaxy at z = 1.49 behind the Frontier Fields cluster MACS1149, and provides a unique opportunity to study the environment of SNe at high z. We

  13. Metallic Sn spheres and SnO2@C core-shells by anaerobic and aerobic catalytic ethanol and CO oxidation reactions over SnO2 nanoparticles.

    Science.gov (United States)

    Kim, Won Joo; Lee, Sung Woo; Sohn, Youngku

    2015-08-24

    SnO2 has been studied intensely for applications to sensors, Li-ion batteries and solar cells. Despite this, comparatively little attention has been paid to the changes in morphology and crystal phase that occur on the metal oxide surface during chemical reactions. This paper reports anaerobic and aerobic ethanol and CO oxidation reactions over SnO2 nanoparticles (NPs), as well as the subsequent changes in the nature of the NPs. Uniform SnO2@C core-shells (10 nm) were formed by an aerobic ethanol oxidation reaction over SnO2 NPs. On the other hand, metallic Sn spheres were produced by an anaerobic ethanol oxidation reaction at 450 °C, which is significantly lower than that (1200 °C) used in industrial Sn production. Anaerobic and aerobic CO oxidation reactions were also examined. The novelty of the methods for the production of metallic Sn and SnO2@C core-shells including other anaerobic and aerobic reactions will contribute significantly to Sn and SnO2-based applications.

  14. Photo and electroluminescence of ZnSe: Sn and ZnSe:(Sn, Pr) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2016-09-01

    We have prepared ZnSe (luminescent grade) phosphor doped with Sn and (Sn,Pr) with varying concentration in an inert atmosphere in a silica tubular furnace at temperature of (780 ± 20) °C for 1 hr to obtain ZnSe:Sn and ZnSe: (Sn,Pr) phosphors. The photo luminescence (PL) and electroluminescence (EL) spectra of these phosphors have been studied at room temperature and results were discussed in the light of existing models. Dependence of EL emission on the voltage frequency has also been carried out. It is found that the plot between the integrated light intensity versus 1/√Vrms is a straight line suggesting the existence of Mott-Schottky type barrier on the metal semiconductor interface.

  15. Spectroscopic classification of SN2017gvr as a peculiar type Ib SN

    Science.gov (United States)

    Martinez, Jorge; Galbany, L.; Gonzalez-Gaitan, S.; Forster, F.

    2017-09-01

    We report the spectroscopic classification of SN2017gvr as a peculiar type Ib supernova discovered by the OGLE-IV Real-time Transient Search (Wyrzykowski et al., 2014 arxiv:1409.1095; http://ogle.astrouw.edu.pl/).

  16. Valence modulations in CeRuSn

    NARCIS (Netherlands)

    Feyerherm, R.; Dudzik, E.; Prokeš, K.; Mydosh, J.A.; Huang, Y.K.; Pöttgen, R.

    2014-01-01

    CeRuSn exhibits an extraordinary room temperature structure at 300 K with the coexistence of two types of Ce ions, namely trivalent Ce3+ and intermediate-valent Ce(4−δ)+, in a metallic environment. The ordered arrangement of these two Ce types on specific crystallographic sites results in a doubling

  17. Beta decay of {sup 103}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O.; Kavatsyuk, M. [GSI, Darmstadt (Germany); National Taras Shevcjenko Univ. of Kyiv (Australia); Batist, L. [St. Petersburg Nuclear Physics Inst. (Russian Federation); Univ. di Napoli (Italy); INFN, Napoli (Italy); Banu, A.; Becker, F.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Kirchner, R.; Mandal, S.; Mazzocchi, C.; Plettner, C.; Roeckl, E.; Schaedel, M. [GSI, Darmstadt (Germany); Blazhev, A. [GSI, Darmstadt (Germany); Univ. Sofia (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen (Germany); Janas, Z.; Karny, M.; Plochocki, A.; Zylicz, J. [University of Warsaw (Poland); Jungclaus, A. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica (Spain); La Commara, M.; Romoli, M. [INFN, Napoli (Italy); Mukha, I. [GSI, Darmstadt (Germany); Kurchatov Inst. Moscow (Russian Federation); Muralithar, S. [GSI, Darmstadt (Germany); Forschungszentrum Rossendorf (Germany); Schwengner, R. [Forschungszentrum Rossendorf (Germany)

    2005-08-01

    The {beta} decay of {sup 103}Sn, a three-neutron-particle nucleus with respect to the {sup 100}Sn core, was investigated at the GSI on-line mass separator using an array of 17 germanium crystals and a total absorption spectrometer. A total of 31 {beta}-delayed {gamma}-rays (29 new) of the {sup 103}Sn{yields}{sup 103}In decay were observed and, on the basis of {beta}-{gamma}-{gamma} coincidences, the {sup 103}Sn decay scheme was established for the first time. By means of total absorption spectroscopy, {beta} intensities, the Gamow-Teller strength distribution and the summed Gamow-Teller strength value of 3.5{+-}0.5 were determined for this decay. Its half-life and Q{sub EC} value were found to be 7.0{+-}0.2 s and 7.64{+-}0.7 MeV, respectively. The {beta}-delayed proton branching ratio was measured to be 1.2{+-}0.1%. The results are discussed in comparison with shell-model predictions based on realistic and empirical interactions. (orig.)

  18. Reaction mechanisms: Stripping down SN2

    Science.gov (United States)

    Orr-Ewing, Andrew J.

    2012-07-01

    The mechanism of the SN2 reaction is fundamental to understanding and controlling the stereochemistry of organic reactions, but surrounding solvent molecules may complicate the textbook picture. Micro-solvation studies have now explored the stereochemical consequences of the presence of one or two solvent molecules.

  19. Atmospheric pressure chemical vapour deposition of SnSe and SnSe{sub 2} thin films on glass

    Energy Technology Data Exchange (ETDEWEB)

    Boscher, Nicolas D.; Carmalt, Claire J.; Palgrave, Robert G. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom); Parkin, Ivan P. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)], E-mail: i.p.parkin@ucl.ac.uk

    2008-06-02

    Atmospheric pressure chemical vapour deposition of tin monoselenide and tin diselenide films on glass substrate was achieved by reaction of diethyl selenide with tin tetrachloride at 350-650 {sup o}C. X-ray diffraction showed that all the films were crystalline and matched the reported pattern for SnSe and/or SnSe{sub 2}. Wavelength dispersive analysis by X-rays show a variable Sn:Se ratio from 1:1 to 1:2 depending on conditions. The deposition temperature, flow rates and position on the substrate determined whether mixed SnSe-SnSe{sub 2}, pure SnSe or pure SnSe{sub 2} thin films could be obtained. SnSe films were obtained at 650 {sup o}C with a SnCl{sub 4} to Et{sub 2}Se ratio greater than 10. The SnSe films were silver-black in appearance and adhesive. SnSe{sub 2} films were obtained at 600-650 {sup o}C they had a black appearance and were composed of 10 to 80 {mu}m sized adherent crystals. Films of SnSe only 100 nm thick showed complete absorbtion at 300-1100 nm.

  20. SN 2006oz: rise of a super-luminous supernova observed by the SDSS-II SN Survey

    DEFF Research Database (Denmark)

    Leloudas, Georgios; Chatzopoulos, E.; Dilday, B.;

    2012-01-01

    to contribute to a better understanding of these objects by studying SN 2006oz, a newly-recognized member of this class. Methods. We present multi-color light curves of SN 2006oz from the SDSS-II SN Survey that cover its rise time, as well as an optical spectrum that shows that the explosion occurred at z ~ 0...

  1. Spliceosomal small nuclear RNAs of Tetrahymena thermophila and some possible snRNA-snRNA base-pairing interactions

    DEFF Research Database (Denmark)

    Orum, H; Nielsen, Henrik; Engberg, J

    1991-01-01

    We have identified and characterized the full set of spliceosomal small nuclear RNAs (snRNAs; U1, U2, U4, U5 and U6) from the ciliated protozoan Tetrahymena thermophila. With the exception of U4 snRNA, the sizes of the T. thermophila snRNAs are closely similar to their metazoan homologues. The T...

  2. Characteristics of Reactive Ni3Sn4 Formation and Growth in Ni-Sn Interlayer Systems

    Science.gov (United States)

    Lis, Adrian; Kenel, Christoph; Leinenbach, Christian

    2016-06-01

    The near-isothermal growth and formation of Ni3Sn4 intermetallic compounds (IMC) in Ni-Sn interlayer systems was studied in the solid state at 473 K (200 °C) and under solid-liquid conditions at 523 and 573 K (250 °C and 300 °C) from an initial state of a few seconds. Scalloped solid-state IMC formation was mainly driven by grain boundary diffusion of Ni through the IMC layer combined with the grain coarsening of the IMC layer. Under solid-liquid conditions, the formation of faceted and needle-shaped Ni3Sn4 grains as well as an atypical IMC growth behavior with similar parabolic growth constants for 523 K and 573 K (250 °C and 300 °C) was observed within the first 180 seconds of the holding time, and IMC growth occurred as an isothermal solidification from the Ni-saturated Sn melt. Due to the progressive densification of the IMC layer and the diffusion-controlled growth, the kinetics slowed down by approximately one order of magnitude after 180 seconds of annealing. The final stage was characterized by the formation of IMC islands ahead of the interfacial Ni3Sn4 layer. Needle-like IMC growth was effectively suppressed under combined solid-state and solid-liquid conditions. Textured Ni3Sn4 IMC formation at the Ni-Sn interface was approved with pole figure measurements. The activation energy Q for solid-liquid IMC formation was calculated as 43.3 kJ/mol, and processing maps for IMC growth and Sn consumption were derived as functions of temperature and time, respectively.

  3. 75 FR 28183 - World Trade Week, 2010

    Science.gov (United States)

    2010-05-20

    .... World Trade Week is an opportunity for us to reaffirm the importance of trade to our Nation's continued economic recovery and growth. Our Nation is still emerging from an unprecedented economic crisis. Millions...#0;#0; ] Proclamation 8521 of May 12, 2010 World Trade Week, 2010 By the President of the...

  4. A double Weekly Bulletin over Easter

    CERN Multimedia

    2004-01-01

    During the Easter period, the weeks of 12 and 19 April, there will be only one issue of the Weekly Bulletin (no. 16-17/2004). Announcements for publication in the next issue (no. 18/2004) should be sent on Tuesday 20 April midday at the latest. Publication Section Tel. 79971

  5. Just one week 'til GridWorld

    CERN Multimedia

    Harris, Derrick

    2006-01-01

    "Here we are, one week from GridWorld, and I can feel the pressure rising. Although the news has been a little slow recently, I know that won't last long, and between next week and mid-November, I have a feelling I'll have heard from just about every vendor and organization in the Grid space." (1 page)

  6. 77 FR 68045 - American Education Week, 2012

    Science.gov (United States)

    2012-11-15

    ... Documents#0;#0; ] Proclamation 8904 of November 9, 2012 American Education Week, 2012 By the President of the United States of America A Proclamation All children deserve access to a world-class education and... Nation's economic prosperity and civic life. This week, we reaffirm our national mission of educating...

  7. 76 FR 20215 - National Volunteer Week, 2011

    Science.gov (United States)

    2011-04-12

    ... real and lasting impact on the lives of millions of women and men across the globe. Last year, nearly... they see a need. During National Volunteer Week, we celebrate the profound impact of volunteers and... week by volunteering in service projects across our country and pledging to make service a part...

  8. 75 FR 70999 - National Entrepreneurship Week, 2010

    Science.gov (United States)

    2010-11-19

    ... Proclamation 8600--National Entrepreneurship Week, 2010 Proclamation 8601--America Recycles Day, 2010 #0; #0... 15, 2010 National Entrepreneurship Week, 2010 By the President of the United States of America A... and work hard enough, the American dream is within your reach. During National Entrepreneurship...

  9. National Poison Prevention Week Promotional Materials.

    Science.gov (United States)

    Poison Prevention Week Council, Washington, DC.

    This collection of materials for parents, early childhood workers, the elderly, and anyone in situations requiring safeguards against poisoning, spans the years 1993 and 1994 and is intended to promote National Poison Prevention Week. The materials included are: (1) the 31-page, illustrated report on National Poison Prevention Week for 1993,…

  10. Behind The Feast Reflection on Golden Week

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Eight years ago, the Golden Week holiday was born in China. Today, it has become an indispensable part of people's life. Every year when the Golden Week is approaching,the lines that form at the ticket windows at railway stations seem endless; shopping malls flood the market with various sales promotions; and people rush to the most scenic spots all over the country.

  11. 77 FR 69733 - National Family Week, 2012

    Science.gov (United States)

    2012-11-21

    ... Week, 2012 By the President of the United States of America A Proclamation The bonds that tie us to our... prosperity has always come from an economy that is built on a strong and growing middle class-- families who... opportunity for all who are working hard to get ahead. During National Family Week, let us recommit to keeping...

  12. SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cenko, S. B.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Jha, S. W.; McCully, C. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Anderson, J. P.; De Jaeger, T.; Forster, F. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Benetti, S. [INAF Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Bufano, F., E-mail: mjc@mso.anu.edu.au [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); and others

    2013-06-10

    We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II {lambda}6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II {lambda}6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of {approx}12,000 km s{sup -1} until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v Almost-Equal-To 12,000 km s{sup -1} with narrow line width and long velocity plateau, as well as an HVF beginning at v Almost-Equal-To 31,000 km s{sup -1} two weeks before maximum. SN 2012fr resides on the border between the ''shallow silicon'' and ''core-normal'' subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the ''low velocity gradient'' group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

  13. The melting diagram of the Ti-Zr-Sn system below 40 at.% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A.; Meleshevich, K.A.; Samelyuk, A.V. [I.N. Frantsevich Institute for Problems of Materials Science, Street Krzhyzhanovsky, 3, Kiev 03142 (Ukraine); Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Street Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: bulanova@lycos.com; Tedenac, J.C. [Institut de Chimie moleculaire et des materiaux-I.C.G., UMR-CNRS 5253-Universite Montpellier II, case 1504, Pl. Eugene Bataillon, 34095 Montpellier Cedex 5 (France)

    2009-04-03

    By the methods of DTA, X-ray diffraction, metallography and EPMA, phase equilibria in the Ti-Zr-Sn system at <40 at.% Sn were studied. The partial liquidus and solidus projections, and the melting diagram (solidus + liquidus) were constructed. The liquidus surface is characterized by the presence of primary crystallization regions of ({beta}Ti) ({beta}), (Ti{sub 3}Sn) ({alpha}{sub 2}) and (Ti,Zr){sub 5}Sn{sub 3} (5/3) phases. The solidus surface is characterized by the presence of two three-phase fields, {beta} + {alpha}{sub 2} + 5/3 and {alpha}{sub 2} + (Ti{sub 2}Sn)(2/1) + 5/3. The first one results from an invariant four-phase equilibrium L{sub U} + {alpha}{sub 2} {r_reversible} {beta} + 5/3 taking place at 1510 {+-} 10 deg. C. The invariant point U is located at the composition {approx}53Ti-30Zr-17Sn. The second three-phase region results from an equilibrium at 1515 deg. C with participation of L + {alpha}{sub 2} + 5/3 + 2/1 phases. The character of the equilibrium is not determined. Two invariant three-phase equilibria were found, L{sub e{sub 1}}{r_reversible}{alpha}{sub 2}+5/3 at 1600-1650 deg. C and L{sub e{sub 4}}{r_reversible}{beta}+5/3 at 1423 deg. C.

  14. On integrable deformations of superstring sigma models related to AdSn×Sn supercosets

    Directory of Open Access Journals (Sweden)

    B. Hoare

    2015-08-01

    Full Text Available We consider two integrable deformations of 2d sigma models on supercosets associated with AdSn×Sn. The first, the “η-deformation” (based on the Yang–Baxter sigma model, is a one-parameter generalization of the standard superstring action on AdSn×Sn, while the second, the “λ-deformation” (based on the deformed gauged WZW model, is a generalization of the non-abelian T-dual of the AdSn×Sn superstring. We show that the η-deformed model may be obtained from the λ-deformed one by a special scaling limit and analytic continuation in coordinates combined with a particular identification of the parameters of the two models. The relation between the couplings and deformation parameters is consistent with the interpretation of the first model as a real quantum deformation and the second as a root of unity quantum deformation. For the AdS2×S2 case we then explore the effect of this limit on the supergravity background associated with the λ-deformed model. We also suggest that the two models may form a dual Poisson–Lie pair and provide direct evidence for this in the case of the integrable deformations of the coset associated with S2.

  15. Selective increase of in vivo firing frequencies in DA SN neurons after proteasome inhibition in the ventral midbrain.

    Science.gov (United States)

    Subramaniam, Mahalakshmi; Kern, Beatrice; Vogel, Simone; Klose, Verena; Schneider, Gaby; Roeper, Jochen

    2014-09-01

    The impairment of protein degradation via the ubiquitin-proteasome system (UPS) is present in sporadic Parkinson's disease (PD), and might play a key role in selective degeneration of vulnerable dopamine (DA) neurons in the substantia nigra pars compacta (SN). Further evidence for a causal role of dysfunctional UPS in familial PD comes from mutations in parkin, which results in a loss of function of an E3-ubiquitin-ligase. In a mouse model, genetic inactivation of an essential component of the 26S proteasome lead to widespread neuronal degeneration including DA midbrain neurons and the formation of alpha-synuclein-positive inclusion bodies, another hallmark of PD. Studies using pharmacological UPS inhibition in vivo had more mixed results, varying from extensive degeneration to no loss of DA SN neurons. However, it is currently unknown whether UPS impairment will affect the neurophysiological functions of DA midbrain neurons. To answer this question, we infused a selective proteasome inhibitor into the ventral midbrain in vivo and recorded single DA midbrain neurons 2 weeks after the proteasome challenge. We found a selective increase in the mean in vivo firing frequencies of identified DA SN neurons in anesthetized mice, while those in the ventral tegmental area (VTA) were unaffected. Our results demonstrate that a single-hit UPS inhibition is sufficient to induce a stable and selective hyperexcitability phenotype in surviving DA SN neurons in vivo. This might imply that UPS dysfunction sensitizes DA SN neurons by enhancing 'stressful pacemaking'.

  16. 70 °C synthesis of high-Sn content (25%) GeSn on insulator by Sn-induced crystallization of amorphous Ge

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K., E-mail: toko@bk.tsukuba.ac.jp; Oya, N.; Suemasu, T. [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Saitoh, N.; Yoshizawa, N. [Electron Microscope Facility, TIA, AIST, 16-1 Onogawa, Tsukuba 305-8569 (Japan)

    2015-02-23

    Polycrystalline GeSn thin films are fabricated on insulating substrates at low temperatures by using Sn-induced crystallization of amorphous Ge (a-Ge). The Sn layer stacked on the a-Ge layer (100-nm thickness each) had two roles: lowering the crystallization temperature of a-Ge and composing GeSn. Slow annealing at an extremely low temperature of 70 °C allowed for a large-grained (350 nm) GeSn layer with a lattice constant of 0.590 nm, corresponding to a Sn composition exceeding 25%. The present investigation paves the way for advanced electronic optical devices integrated on a flexible plastic substrate as well as on a Si platform.

  17. Low Temperature Deposition of High-k/Metal Gate Stacks on High-Sn Content (Si)GeSn-Alloys.

    Science.gov (United States)

    Schulte-Braucks, C; von den Driesch, N; Glass, S; Tiedemann, A T; Breuer, U; Besmehn, A; Hartmann, J-M; Ikonic, Z; Zhao, Q T; Mantl, S; Buca, D

    2016-05-25

    (Si)GeSn is an emerging group IV alloy system offering new exciting properties, with great potential for low power electronics due to the fundamental direct band gap and prospects as high mobility material. In this Article, we present a systematic study of HfO2/TaN high-k/metal gate stacks on (Si)GeSn ternary alloys and low temperature processes for large scale integration of Sn based alloys. Our investigations indicate that SiGeSn ternaries show enhanced thermal stability compared to GeSn binaries, allowing the use of the existing Si technology. Despite the multielemental interface and large Sn content of up to 14 atom %, the HfO2/(Si)GeSn capacitors show small frequency dispersion and stretch-out. The formed TaN/HfO2/(Si)GeSn capacitors present a low leakage current of 2 × 10(-8) A/cm(2) at -1 V and a high breakdown field of ∼8 MV/cm. For large Sn content SiGeSn/GeSn direct band gap heterostructures, process temperatures below 350 °C are required for integration. We developed an atomic vapor deposition process for TaN metal gate on HfO2 high-k dielectric and validated it by resistivity as well as temperature and frequency dependent capacitance-voltage measurements of capacitors on SiGeSn and GeSn. The densities of interface traps are deduced to be in the low 10(12) cm(-2) eV(-1) range and do not depend on the Sn-concentration. The new processes developed here are compatible with (Si)GeSn integration in large scale applications.

  18. Diffusion couple studies of the Ni-Bi-Sn system

    Directory of Open Access Journals (Sweden)

    Vassilev G.

    2012-01-01

    Full Text Available Investigations of Ni-Bi-Sn system were performed in order to inquire the phase diagram and to assess some diffusion kinetic parameters. For this purpose diffusion couples consisting of solid nickel (preliminary electroplated with tin and liquid Bi-Sn phase were annealed at 370 °C. Three compositions (0.8, 0.6 and 0.4 mole fractions Sn of the Bi-Sn melts were chosen. Annealing times from 24 to 216 h were applied. The phase and chemical compositions of the contact zone were determined by means of electron scanning microscope. It was confirmed that the diffusion layers consist mainly of Ni3Sn4 but other intermetallic phases grow as well. For the first time metastable Ni-Sn phases as NiSn and NiSn8 (NiSn9 were observed in metallurgical alloys (i.e. not in electroplated samples. The existence of a ternary compound previously reported in the literature was confirmed. More than one ternary Ni-Bi-Sn compounds might possibly be admitted. A growth coefficient of (2.29 ± 0.02 x 10-15 m2 s-1 was obtained. It was found that the apparent activation energy for diffusion layers growth (18 ± 8 kJ mol-1 is inferior to that one assessed at growth from solid state Bi-Sn mixtures (88 ± 12 kJ mol-1.

  19. (Si)GeSn nanostructures for light emitters

    Science.gov (United States)

    Rainko, D.; Stange, D.; von den Driesch, N.; Schulte-Braucks, C.; Mussler, G.; Ikonic, Z.; Hartmann, J. M.; Luysberg, M.; Mantl, S.; Grützmacher, D.; Buca, D.

    2016-05-01

    Energy-efficient integrated circuits for on-chip or chip-to-chip data transfer via photons could be tackled by monolithically grown group IV photonic devices. The major goal here is the realization of fully integrated group IV room temperature electrically driven lasers. An approach beyond the already demonstrated optically-pumped lasers would be the introduction of GeSn/(Si)Ge(Sn) heterostructures and exploitation of quantum mechanical effects by reducing the dimensionality, which affects the density of states. In this contribution we present epitaxial growth, processing and characterization of GeSn/(Si)Ge(Sn) heterostructures, ranging from GeSn/Ge multi quantum wells (MQWs) to GeSn quantum dots (QDs) embedded in a Ge matrix. Light emitting diodes (LEDs) were fabricated based on the MQW structure and structurally analyzed via TEM, XRD and RBS. Moreover, EL measurements were performed to investigate quantum confinement effects in the wells. The GeSn QDs were formed via Sn diffusion /segregation upon thermal annealing of GeSn single quantum wells (SQW) embedded in Ge layers. The evaluation of the experimental results is supported by band structure calculations of GeSn/(Si)Ge(Sn) heterostructures to investigate their applicability for photonic devices.

  20. Beta Decay of 101Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mazzocchi, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Janas, Z. [University of Warsaw; Banu, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Batist, L. [St. Petersburg Nuclear Physics Institute; Becker, F. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Blazhev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Bruchle, W. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Faestermann, T. [Technische Universitat Munchen; Gorska, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Jungclaus, A. [Instituto Estructura de la Materia, Madrid; Karny, M. [University of Warsaw; Kavatsyuk, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Klepper, O. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; La Commara, M. [Universita Federico II and INFN Napoli; Miernik, K. [University of Warsaw; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plochocki, A. [University of Warsaw; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Romoli, M. [Universita Federico II and INFN Napoli; Rykaczewski, Krzysztof Piotr [ORNL; Schadel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schmidt, K. [Continental Teves AG & Co., Frankfurt am Main, Germany; Schwengner, R. [Forschungszentrum Rossendorf, Dresden, Germany; Zylicz, J. [University of Warsaw

    2007-01-01

    The {beta} decay of the very neutron-deficient isotope 101Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors for {gamma}-ray spectroscopy. Based on the {beta}-delayed proton data the production cross-section of 101Sn in the 50Cr + 58Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of 101Sn was measured to be 1.9(3)s. For the first time {beta}-delayed {gamma}-rays of 101Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in 101In. The results for the 101Sn decay as well as those from previous work on the 103Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction in the 88Sr to 132Sn model space.

  1. Martensitic Transformation in Ni-Mn-Sn-Co Heusler Alloys

    Directory of Open Access Journals (Sweden)

    Alexandre Deltell

    2015-04-01

    Full Text Available Thermal and structural austenite to martensite reversible transition was studied in melt spun ribbons of Ni50Mn40Sn5Co5, Ni50Mn37.5Sn7.5Co5 and Ni50Mn35Sn10Co5 (at. % alloys. Analysis of X-ray diffraction patterns confirms that all alloys have martensitic structure at room temperature: four layered orthorhombic 4O for Ni50Mn40Sn5Co5, four layered orthorhombic 4O and seven-layered monoclinic 14M for Ni50Mn37.5Sn7.5Co5 and seven-layered monoclinic 14M for Ni50Mn35Sn5Co5. Analysis of differential scanning calorimetry scans shows that higher enthalpy and entropy changes are obtained for alloy Ni50Mn37.5Sn7.5Co5, whereas transition temperatures increases as increasing valence electron density.

  2. Chemically Resolved Structure of the Sn/Ge(111) Surface

    Science.gov (United States)

    Lee, Tien-Lin; Warren, Samantha; Cowie, Bruce C. C.; Zegenhagen, Jörg

    2006-02-01

    The structure and chemical states of the Sn/Ge(111) surface are characterized by x-ray standing waves combined with photoemission. For the room temperature 3×3 phase two chemical components, approximately 0.4 eV apart, are observed for both Sn 3d and 4d core levels. Our model-independent, x-ray standing wave analysis shows unambiguously that the two components originate from Sn adatoms located at two different heights separated vertically by 0.23 Å, in favor of a model composed of a fluctuating Sn layer. Contrary to the most accepted scenario, the stronger Sn 3d and 4d components, which appear at the lower binding-energy sides and account for 2/3 of the Sn adatoms, are identified to be associated with the higher Sn position, manifesting their filled valence state character.

  3. Vehicle Technologies Fact of the Week 2015

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Stacy C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Diegel, Susan W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moore, Sheila A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boundy, Robert G. [Roltek, Inc., Clinton, TN (United States)

    2016-05-01

    Each week the U.S. Department of Energy s Vehicle Technology Office (VTO) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/ . These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current week s Fact is available on the VTO homepage, but older Facts (back to 2009) are archived and still available at: http://energy.gov/eere/vehicles/current-and-past-years-facts-week. Each Fact of the Week website page includes a link to an Excel file. That file contains the data from the Supporting Information section of the page so that researchers can easily use data from the Fact of the Week in their work. Beginning in August of 2015, a subscription list is available on the DOE website so that those interested can sign up for an email to be sent each Monday which includes the text and graphic from the current week s Fact. This report is a compilation of the Facts that were posted during calendar year 2015. The Facts were created, written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.

  4. Low Temperature Deposition of High-k/Metal Gate Stacks on High-Sn Content (Si)GeSn-Alloys

    OpenAIRE

    Schulte-Braucks, C; Von Den Driesch, N; Glass, S; Tiedemann, AT; Breuer, U; Besmehn, A; Hartmann, JM; Ikonic, Z; Zhao, QT; Mantl, S; Buca, D.

    2016-01-01

    (Si)GeSn is an emerging group IV alloy system offering new exciting properties, with great potential for low power electronics due to the fundamental direct band gap and prospects as high mobility material. In this Article, we present a systematic study of HfO2/TaN high-k/metal gate stacks on (Si)GeSn ternary alloys and low temperature processes for large scale integration of Sn based alloys. Our investigations indicate that SiGeSn ternaries show enhanced thermal stability compared to GeSn bi...

  5. Lattice Thermal Conductivity of the Binary and Ternary Group-IV Alloys Si-Sn, Ge-Sn, and Si-Ge-Sn

    Science.gov (United States)

    Khatami, S. N.; Aksamija, Z.

    2016-07-01

    Efficient thermoelectric (TE) energy conversion requires materials with low thermal conductivity and good electronic properties. Si-Ge alloys, and their nanostructures such as thin films and nanowires, have been extensively studied for TE applications; other group-IV alloys, including those containing Sn, have not been given as much attention as TEs, despite their increasing applications in other areas including optoelectronics. We study the lattice thermal conductivity of binary (Si-Sn and Ge-Sn) and ternary (Si-Ge-Sn) alloys and their thin films in the Boltzmann transport formalisms, including a full phonon dispersion and momentum-dependent boundary-roughness scattering. We show that Si-Sn alloys have the lowest conductivity (3 W /mK ) of all the bulk alloys, more than 2 times lower than Si-Ge, attributed to the larger difference in mass between the two constituents. In addition, we demonstrate that thin films offer an additional reduction in thermal conductivity, reaching around 1 W /mK in 20-nm-thick Si-Sn, Ge-Sn, and ternary Si-Ge-Sn films, which is near the conductivity of amorphous SiO2 . We conclude that group-IV alloys containing Sn have the potential for high-efficiency TE energy conversion.

  6. Synthesis of carbon-supported PdSn-SnO2 nanoparticles with different degrees of interfacial contact and enhanced catalytic activities for formic acid oxidation.

    Science.gov (United States)

    Wang, Hui; Liu, Ziyue; Ma, Yanjiao; Julian, Key; Ji, Shan; Linkov, Vladimir; Wang, Rongfang

    2013-09-07

    The conjunction of the PdSn alloy and SnO2 is of interest for improving catalytic activity in formic acid oxidation (FAO). Here, we report the synthesis of PdSn-SnO2 nanoparticles and a study of their catalytic FAO activity. Different degrees of interfacial contact between SnO2 and PdSn were obtained using two different stabilizers (sodium citrate and EDTA) during the reduction process in catalyst preparation. Compared to the PdSn alloy, PdSn-SnO2 supported on carbon black showed enhanced FAO catalytic activity due to the presence of SnO2 species. It was also found that interfacial contact between the PdSn alloy and the SnO2 phase has an impact on the activity towards CO oxidation and FAO.

  7. Demethylation restores SN38 sensitivity in cells with acquired resistance to SN38 derived from human cervical squamous cancer cells

    Science.gov (United States)

    TANAKA, TETSUJI; BAI, TAO; TOUJIMA, SAORI; UTSUNOMIYA, TOMOKO; MATSUOKA, TOSHIHIDE; KOBAYASHI, AYA; YAMAMOTO, MADOKA; SASAKI, NORIYUKI; TANIZAKI, YUKO; UTSUNOMIYA, HIROTOSHI; TANAKA, JUNKO; YUKAWA, KAZUNORI

    2012-01-01

    Using seven monoclonal SN38-resistant subclones established from ME180 human cervical squamous cell carcinoma cells, we examined the demethylation effects of 5-aza-2′-deoxycytidine (5-aza-CdR) on the SN38-sensitivity of the cells as well as the expression of death-associated protein kinase (DAPK) in the SN38-resistant cells. The DAPK expression levels were evaluated among parent ME180 cells, SN38-resistant ME180 cells and cisplatin-resistant ME180 cells by methylation-specific DAPK-PCR, quantitative RT-PCR and western blot analysis. The SN38-resistant cells co-treated with SN38 and 5-aza-CdR strongly exhibited enhanced SN38-sensitivities resembling those found in the parent cells. In the SN38-resistant subclones, no relationships were found between the restored SN38 sensitivity and hypermethylation of the DAPK promoter, DAPK mRNA expression, DAPK protein expression and induction of DAPK protein after 5-aza-CdR treatment, unlike the strong suppression of 5-aza-CdR-induced DAPK protein expression in the cisplatin-resistant subclones. These findings indicate that reversibly methylated molecules, but not DAPK, may regulate SN38 resistance, and that demethylating agents can be strong sensitizing anticancer chemotherapeutic drugs for SN38-resistant cancers. PMID:22246465

  8. Hyperfine field distributions in disordered Mn2CoSn and Mn2NiSn Heusler alloys

    Indian Academy of Sciences (India)

    N Lakshmi; Anil Pandey; K Venugopalan

    2002-08-01

    Heusler alloys, Mn2CoSn and Mn2NiSn, were prepared and characterized by X-ray studies. Mössbauer studies using Sn-119 were carried out to investigate the hyperfine fields present at the Sn site in these alloys. The hyperfine field distribution in these alloys as well as X-ray studies point to the chemical disorder present in both alloys. Co-existence of a paramagnetic portion along with the magnetic hyperfine part was observed in Mn2CoSn even at low temperatures, while this was not found in Mn2NiSn spectra. Hyperfine fields at Sn site were calculated using Blandin and Campbell model and compared with the experimental results.

  9. Sn migration control at high temperature due to high deposition speed for forming high-quality GeSn layer

    Science.gov (United States)

    Taoka, Noriyuki; Capellini, Giovanni; von den Driesch, Nils; Buca, Dan; Zaumseil, Peter; Schubert, Markus Andreas; Klesse, Wolfgang Matthias; Montanari, Michele; Schroeder, Thomas

    2016-03-01

    A key factor for controlling Sn migration during GeSn deposition at a high temperature of 400 °C was investigated. Calculated results with a simple model for the Sn migration and experimental results clarified that low-deposition-speed (vd) deposition with vd’s of 0.68 and 2.8 nm/min induces significant Sn precipitation, whereas high-deposition-speed (vd = 13 nm/min) deposition leads to high crystallinity and good photoluminescence spectrum of the GeSn layer. These results indicate that vd is a key parameter, and that control of Sn migration at a high temperature is possible. These results are of great relevance for the application of high-quality Sn-based alloys in future optoelectronics devices.

  10. Synthesis kinetics of Mg_2Sn in Mg-Sn powder mixture using non-isothermal differential scanning calorimetry

    Institute of Scientific and Technical Information of China (English)

    WU Yu-feng; DU Wen-bo; ZUO Tie-yong

    2009-01-01

    The non-isothermal heating process of Mg-Sn powder mixture was studied by differential scanning calorimetry(DSC) technique and the synthesis kinetics of Mg_2Sn was evaluated by the model-free and model-fitting methods. The activation energy and conversion function of Mg_2Sn synthesis reaction are calculated to be 281.7 kJ/mol and g(α)=[-ln(1-α)]~(1/4), respectively. The reaction mechanism of 2Mg+Sn→Mg_2Sn under non-isothermal condition is regarded as "nucleation and growth". During the non-isothermal heating process, the phase transformation occurred in the Mg-Sn powder mixture was analyzed by XRD and the microstructure evolution of Mg_2Sn was observed by optical microscopy, which is in good agreement with the reaction mechanism of 2Mg+Sn→Mg_2Sn deduced from the kinetic evaluation.

  11. Effect of Sn content on the properties of passive film on PbSn alloy in sulfuric acid solution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effect of Sn content on properties of anodic film formed on PbSn alloys in sulfuric acid solution was investigated using linear sweeping voltage (LSV), cyclic voltammetry (CV), and a.c. voltammetry (ACV), based on the Mott-Schottky analysis. The results revealed that the addition of Sn into lead alloys can promote the corrosion resistance property and could decrease the impedance of anodic film; these results were more remarkable with enhancing the Sn content. The over potential of oxygen evolution on lead alloys enhanced with the increase of Sn content. The Mott-Schottky analysis indicated that the passive film appeared an n-type semiconductor, and the donor density of passive film increased with increasing Sn content. The increased vacancies in the passive film with Sn content increasing could illustrate this trend.

  12. Bi-weekly waterfowl survey data entry

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data sheet for the entry of bi-weekly waterfowl survey data from the state of Kansas. This Excel file contains the data entry sheet and a chart displaying waterfowl...

  13. Moessbauer Investigation of Electrodeposited Sn-Zn, Sn-Cr, Sn-Cr-Zn and Fe-Ni-Cr Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, E.; Stichleutner, S. [Eoetvoes University, Department of Nuclear Chemistry and Research Group of Nuclear Methods in Structural Chemistry HAS (Hungary); El-Sharif, M.; Chisholm, C. U. [Glasgow Caledonian University (United Kingdom); Sziraki, L.; Homonnay, Z.; Vertes, A. [Eoetvoes University, Department of Nuclear Chemistry and Research Group of Nuclear Methods in Structural Chemistry HAS (Hungary)

    2002-06-15

    {sup 57}Fe and {sup 119}Sn CEMS, XRD and electrochemical measurements were used to investigate the effect of the preparation parameters and the components on the structure and phase composition of electrodeposited Fe-Ni-Cr alloys in connection with their corrosion behavior. XRD of the electrodeposits reflect an amorphous-like character. {sup 57}Fe CEM spectra of Fe-Ni-Cr electrodeposited samples, prepared in a continuous flow plating plastic circulation cell with variation of current density, electrolyte velocity and temperature, can be evaluated as a doublet associated with a highly disordered paramagnetic solid solution phase. This phase was identified earlier in Fe-Ni-Cr electrodeposits that were prepared by another plating method and contained both ferromagnetic and paramagnetic metastable phases. This is the first time that we have succeeded to prepare Fe-Ni-Cr alloys containing only the metastable paramagnetic phase. The effect of the plating parameters on the structure is also analysed by the quadrupole splitting distribution method. {sup 119}Sn CEM spectra of all Sn-containing plated alloys show a broad line envelop which can be decomposed at least into two components. One can be associated with {beta}-tin. The other one can be assigned to an alloy phase. The structure and distribution of microenvironments of these phases depends on the plating parameters especially on the parameters of the reverse pulse applied.

  14. Comparative gastrointestinal safety of weekly oral bisphosphonates

    Science.gov (United States)

    Katz, J. N.; Brookhart, M. A.; Stürmer, T.; Stedman, M. R.; Levin, R.; Solomon, D. H.

    2012-01-01

    Summary Weekly bisphosphonates are the primary agents used to treat osteoporosis. Although these agents are generally well tolerated, serious gastrointestinal adverse events, including hospitalization for gastrointestinal bleed, may arise. We compared the gastrointestinal safety between weekly alendronate and weekly risedronate and found no important difference between new users of these agents. Introduction Weekly bisphosphonates are the primary agents prescribed for osteoporosis. We examined the comparative gastrointestinal safety between weekly bisphosphonates. Methods We studied new users of weekly alendronate and weekly risedronate from June 2002 to August 2005 among enrollees in a state-wide pharmaceutical benefit program for seniors. Our primary outcome was hospitalization for upper gastrointestinal bleed. Secondary outcomes included outpatient diagnoses for upper gastrointestinal disease, symptoms, endoscopic procedures, use of gastroprotective agents, and switching between therapies. We used Cox proportional hazard models to compare outcomes between agents within 120 days of treatment initiation, adjusting for propensity score quintiles. We also examined composite safety outcomes and stratified results by age and prior gastrointestinal history. Results A total of 10,420 new users were studied, mean age=79 years (SD, 6.9), and 95% women. We observed 31 hospitalizations for upper gastrointestinal bleed (0.91 per 100 person-years) within 120 days of treatment initiation. Adjusting for covariates, there was no difference in hospitalization for upper gastrointestinal bleed among those treated with risedronate compared with alendronate (HR, 1.12; 95%CI, 0.55 to 2.28). Risedronate switching rates were lower; otherwise, no differences were observed for secondary or composite outcomes. Conclusions We found no important difference in gastrointestinal safety between weekly oral bisphosphonates. PMID:19266138

  15. A double Weekly Bulletin over Easter

    CERN Multimedia

    2004-01-01

    During the Easter period, the weeks of 12 and 19 April, there will be only one issue of the Weekly Bulletin (no. 16-17/2004). Items for publication in this double issue should reach the Publication section or Staff Association, as appropriate, before midday on Tuesday 6 April. Announcements for publication in the next issue (no. 18/2004) should be sent on Tuesday 20 April midday at the latest. Publication Section Tel. 79971

  16. SnO{sub 2} thin films grown by atomic layer deposition using a novel Sn precursor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Min-Jung [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Cho, Cheol Jin [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744 (Korea, Republic of); Kim, Kwang-Chon; Pyeon, Jung Joon [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Park, Hyung-Ho [Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Kim, Hyo-Suk; Han, Jeong Hwan; Kim, Chang Gyoun; Chung, Taek-Mo [Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 305-600 (Korea, Republic of); Park, Tae Joo [Department of Materials Science and Engineering, Hanyang University, Ansan, 426-791 (Korea, Republic of); Kwon, Beomjin [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Jeong, Doo Seok; Baek, Seung-Hyub [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Nanomaterials, Korea University of Science and Technology, Daejeon, 305-333 (Korea, Republic of); Kang, Chong-Yun; Kim, Jin-Sang [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Kim, Seong Keun, E-mail: s.k.kim@kist.re.kr [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Nanomaterials, Korea University of Science and Technology, Daejeon, 305-333 (Korea, Republic of)

    2014-11-30

    Highlights: • We developed a new ALD process for SnO{sub 2} films using dimethylamino-2-methyl-2-propoxy-tin(II) as a novel Sn precursor. • The SnO{sub 2} films grown from Sn(dmamp){sub 2} has negligible impurity contents. • Sn ions in the films had a single binding state corresponding to Sn{sup 4+} in SnO{sub 2}. - Abstract: SnO{sub 2} thin films were grown by atomic layer deposition (ALD) with dimethylamino-2-methyl-2-propoxy-tin(II) (Sn(dmamp){sub 2}) and O{sub 3} in a temperature range of 100–230 °C. The ALD window was found to be in the range of 100–200 °C. The growth per cycle of the films in the ALD window increased with temperature in the range from 0.018 to 0.042 nm/cycle. Above 230 °C, the self-limiting behavior which is a unique characteristic of ALD, was not observed in the growth because of the thermal decomposition of the Sn(dmamp){sub 2} precursor. The SnO{sub 2} films were amorphous in the ALD window and exhibited quite a smooth surface. Sn ions in all films had a single binding state corresponding to Sn{sup 4+} in SnO{sub 2}. The concentration of carbon and nitrogen in the all SnO{sub 2} films was below the detection limit of the auger electron spectroscopy technique and a very small amount of carbon, nitrogen, and hydrogen was detected by secondary ions mass spectroscopy only. The impurity contents decreased with increasing the growth temperature. This is consistent with the increase in the density of the SnO{sub 2} films with respect to the growth temperature. The ALD process with Sn(dmamp){sub 2} and O{sub 3} shows excellent conformality on a hole structure with an aspect ratio of ∼9. This demonstrates that the ALD process with Sn(dmamp){sub 2} and O{sub 3} is promising for growth of robust and highly pure SnO{sub 2} films.

  17. Phase equilibria of the Cu-Sn-Ti ternary system at 823K

    Directory of Open Access Journals (Sweden)

    Guo-jun Zhou

    2017-02-01

    Full Text Available The isothermal section in the Cu-Sn enrich part of the Cu-Sn-Ti ternary system at 823K was determined by using solid-solid-liquid diffusion triple approach. One ternary compound CuSnTi was found, and 12 three-phase fields were detected. The following 10 three-phase regions are well established: CuTi2+CuTi+Sn5Ti6, Sn5Ti6+Sn3Ti2+ CuSnTi, Liquid+Sn3Ti2+CuSnTi, Liquid+CuSnTi+Cu3Sn, CuTi+Cu4Ti3+Sn5Ti6, CuSnTi+Cu4Ti3+Sn5Ti6, CuSnTi+Cu3Sn+Cu41Sn11, CuSnTi+Cu41Sn11+Bcc_a2, CuSnTi+Cu4Ti+Cu, and CuSnTi+Bcc_a2+Cu. Phase relations in the Ti-enrich corner of this system require further investigation.

  18. Investigation of Sn surface segregation during GeSn epitaxial growth by Auger electron spectroscopy and energy dispersive x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Takahiro; Suda, Yoshiyuki [Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Hirose, Nobumitsu; Kasamatsu, Akifumi; Mimura, Takashi; Matsui, Toshiaki [National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)

    2015-02-02

    The mechanism of Sn surface segregation during the epitaxial growth of GeSn on Si (001) substrates was investigated by Auger electron spectroscopy and energy dispersive X-ray spectroscopy. Sn surface segregation depends on the growth temperature and Sn content of GeSn layers. During Sn surface segregation, Sn-rich nanoparticles form and move on the surface during the deposition, which results in a rough surface owing to facet formation. The Sn-rich nanoparticles moving on the surface during the deposition absorb Sn from the periphery and yield a lower Sn content, not on the surface but within the layer, because the Sn surface segregation and the GeSn deposition occur simultaneously. Sn surface segregation can occur at a lower temperature during the deposition compared with that during postannealing. This suggests that the Sn surface segregation during the deposition is strongly promoted by the migration of deposited Ge and Sn adatoms on the surface originating from the thermal effect of substrate temperature, which also suggests that limiting the migration of deposited Ge and Sn adatoms can reduce the Sn surface segregation and improve the crystallinity of GeSn layers.

  19. iPTF13ehe in the context of Quark-Novae in massive binaries: double-humped, hydrogen-poor, superluminous Supernovae as standard candles

    CERN Document Server

    Ouyed, Rachid; Koning, Nico

    2015-01-01

    A Quark-Nova (QN; the explosive transition of a Neutron star to a Quark star) occurring in the second common envelope (CE) phase of a massive binary, as described in Ouyed et al. (2015a&b), gives excellent fits to super-luminous, hydrogen-poor, Supernovae (SLSNe) with double-humped light curves including DES13S2cmm, SN 2006oz and LSQ14bdq (see {\\it http://www.quarknova.ca/LCGallery.html}). In our model, the hydrogen envelope of the less massive companion is ejected during the first CE phase while the QN explosion occurs deep inside the He-rich second CE phase after it has expanded to its equilibrium configuration at ~1200Rsun; this yields the first hump in our model. The subsequent merging of the quark star with the CO core leads to black hole formation and accretion explaining the second long-lasting hump in our model, while the collision of the QN-ejected He-rich CE with the H-rich (i.e. first) CE accounts for late emission. Here we show that our model provides an excellent fit to the recently discovere...

  20. Syntheses and structures of Sc2Nb(4–x)Sn5, YNb6Sn6, and ErNb6Sn5: exploratory studies in ternary rare-earth niobium stannides.

    Science.gov (United States)

    Yue, Cheng-Yang; Lei, Xiao-Wu

    2012-02-20

    Three new rare-earth (RE) niobium stannides, namely, Sc(2)Nb(4-x)Sn(5) (x = 0.37, 0.52), YNb(6)Sn(6), and ErNb(6)Sn(5), have been obtained by reacting the mixture of corresponding pure elements at high temperature and structurally characterized by single-crystal X-ray diffraction studies. Sc(2)Nb(4-x)Sn(5) crystallizes in the orthorhombic space group Ibam (No. 72) and belongs to the V(6)Si(5) type. Its structure features a three-dimensional (3D) network composed of two-dimensionally (2D) corrugated [Nb(2)Sn(2)] and [Nb(2)Sn(3)] layers interconnected via Nb-Sn bonds, forming one type of one-dimensional (1D) narrow tunnels along the c axis occupied by Sc atoms. YNb(6)Sn(6) crystallizes in the hexagonal space group P6/mmm (No. 191) and adopts the HfFe(6)Ge(6) type, and ErNb(6)Sn(5) crystallizes in the trigonal space group R3m (No. 166) and belongs to the LiFe(6)Ge(5) type. Their structures both feature 3D networks based on 2D [Nb(3)Sn], [Sn(2)], and [RESn(2)] layers (RE = Y, Er). In YNb(6)Sn(6), one type of [Nb(3)Sn] layer is interconnected by [Sn(2)] and [YSn(2)] layers via Nb-Sn bonds to form a 3D network. However, in ErNb(6)Sn(5), two types of [Nb(3)Sn] layers are interlinked by [Sn(2)] and [ErSn(2)] layers via Nb-Sn bonds into a 3D framework. Electronic structure calculations and magnetic property measurements for "Sc(2)Nb(4)Sn(5)" and YNb(6)Sn(6) indicate that both compounds show semimetallic and temperature-independent diamagnetic behavior.

  1. Temperature dependent electrical resistivity of liquid Sn

    Science.gov (United States)

    Prajapati, A. V.; Sonvane, Y. A.; Patel, H. P.; Thakor, P. B.

    2016-05-01

    The present paper deals with the effect of temperature variation on the electrical resistivity (ρ) of liquid Sn(Tin). We have used a new parameter free pseudopotential along with screening Taylor et al and Farid et al local field correction functions. The Percus-Yevick Hard Sphere (PYHS) reference system is used to describe structural information. Zeeman formula has been used for finding resistivity with the variation of temperature. The balanced harmonies between present data and experimental data have been achieved with a minimal deviation. So, we concluded that our newly constructed model potential is an effective one to produce the data of electrical resistivity of liquid Sn(Tin) as a function of temperature.

  2. LARP Long Nb3Sn Quadrupole Design.

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio,G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore, J.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmalzle, J.; Tartaglia, M.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A.V.

    2007-08-27

    A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.

  3. Mode-Specific SN2 Reaction Dynamics.

    Science.gov (United States)

    Wang, Yan; Song, Hongwei; Szabó, István; Czakó, Gábor; Guo, Hua; Yang, Minghui

    2016-09-01

    Despite its importance in chemistry, the microscopic dynamics of bimolecular nucleophilic substitution (SN2) reactions is still not completely elucidated. In this publication, the dynamics of a prototypical SN2 reaction (F(-) + CH3Cl → CH3F + Cl(-)) is investigated using a high-dimensional quantum mechanical model on an accurate potential energy surface (PES) and further analyzed by quasi-classical trajectories on the same PES. While the indirect mechanism dominates at low collision energies, the direct mechanism makes a significant contribution. The reactivity is found to depend on the specific reactant vibrational mode excitation. The mode specificity, which is more prevalent in the direct reaction, is rationalized by a transition-state-based model.

  4. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

    Science.gov (United States)

    Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

    2017-09-01

    This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

  5. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

    Science.gov (United States)

    Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

    2017-07-01

    This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

  6. A review and prospects for Nb3Sn superconductor development

    Science.gov (United States)

    Xu, Xingchen

    2017-09-01

    Nb3Sn superconductors have significant applications in constructing high-field (>10 T) magnets. This article briefly reviews development of Nb3Sn superconductor and proposes prospects for further improvement. It is shown that significant improvement of critical current density (J c) is needed for future accelerator magnets. After a brief review of the development of Nb3Sn superconductors, the factors controlling J c are summarized and correlated with their microstructure and chemistry. The non-matrix J c of Nb3Sn conductors is mainly determined by three factors: the fraction of current-carrying Nb3Sn phase in the non-matrix area, the upper critical field B c2, and the flux line pinning capacity. Then prospects to improve the three factors are discussed respectively. An analytic model was developed to show how the ratios of precursors determine the phase fractions after heat treatment, based on which it is predicted that the limit of current-carrying Nb3Sn fraction in subelements is ∼65%. Then, since B c2 is largely determined by the Nb3Sn stoichiometry, a thermodynamic/kinetic theory is presented to show what essentially determines the Sn content of Nb3Sn conductors. This theory explains the influences of Sn sources and Ti addition on stoichiometry and growth rate of Nb3Sn layers. Next, to improve flux pinning, previous efforts in this community to introduce additional pinning centers to Nb3Sn wires are reviewed, and an internal oxidation technique is described. Finally, prospects for further improvement of non-matrix J c of Nb3Sn conductors are discussed, and it is seen that the only opportunity for further significantly improving J c lies in improving flux pinning.

  7. Cluster radioactivity leading to doubly magic 100Sn and 132Sn daughters

    Indian Academy of Sciences (India)

    K P Santhosh

    2011-03-01

    Decay of neutron-deficient 128−137Gd parents emitting 4He to 32S clusters are studied within the Coulomb and proximity potential model. The predicted half-lives are compared with other models and most of the values are well within the present experimental limit for measurements (1/2 < 1030} ). The lowest 1/2 value for 28Si emission from 128Gd indicates the role of doubly magic 100Sn daughter in cluster decay process. It is also found that neutron excess in the parent nuclei slows down the cluster decay process. Geiger–Nuttal plots for all clusters are found to be linear with different slopes and intercepts. The -decay half-lives of 148−152Gd parents are computed and are in agreement with experimental data. The role of doubly magic 132Sn daughter in cluster decay process is also examined for various neutron-rich Ba, Ce, Nd, Sm and Gd parents emitting clusters ranging from 4He to 32Si. Alpha-like structures are most probable in the decays leading to 100Sn, while non--like structures are probable in the decays leading to 132Sn. The neutron–proton asymmetry in parent and daughter nuclei is responsible for the reduced decay rate in the decay leading to 132Sn.

  8. 119Sn CEMS study of Sb doped SnO2 film

    Science.gov (United States)

    Nomura, K.; Kuzmann, E.; Garg, V. K.; de Oliveira, A. C.; Stichleutner, S.; Homonnay, Z.

    2016-12-01

    Sb doped SnO2 films prepared by DC sputtering and heating were characterized by 119Sn conversion electron Mössbauer spectrometry (CEMS). An asymmetric doublet was observed in the Mössbauer spectra of 1 %, 3 %, and 10 % Sb doped SnO2 films. The peak ratios of doublets are considered to be due to the columnar crystal growth on the substrate. With the doping level of Sb, both the isomer shift ( δ) and the quadrupole splitting (Δ) increased. After annealing, δ increased and Δ decreased for each sample. These results suggest the followings. The electron doping of the SnO2 lattice by pentavalent Sb induces the increase of the electron density at the SnIV nucleus. The annealing process leads to more complete accommodation of the Sb dopant that results in more effective electron doping and therefore increasing isomer shift for tin. Simultaneously, the distortion of the lattice caused by Sb is relaxed and the quadrupole splitting decreases.

  9. Representation of A15 composition and TC in internal-Sn Nb3Sn superconducting strands

    Institute of Scientific and Technical Information of China (English)

    Andre; SULPICE; Jean-Louis; SOUBEYROUX; Christophe; VERWAERDE; Gia; Ky; HOANG

    2010-01-01

    Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite configurations and some third element alloying were arranged. All the strand samples underwent a 210°C/50 h + 340°C/25 h thermal duration for Cu-Sn alloying. After that A15 phase formation heat treatment (HT) was applied for which the ME samples were chosen at three reaction temperatures of 675°C, 700°C and 725°C for 100 h and 200 h while the MF samples at four temperatures of 650°C, 675°C, 700°C and 725°C for 128 h and 200 h. The heat-treated samples were examined for A15 phase composition distribution by X-ray EDS. SQUID magnetization measurement was used to determine critical temperature TC. The obtained results demonstrate that for fully-reacted internal-Sn Nb3Sn superconductors the A15 phase composition and the intrinsic property TC are determined by the diffusion and solid state reaction mechanism and are independent of the factors including HT temperature, strand composite component and configuration arrangement, and the third element addition within the experimental range.

  10. Constraining Modified Gravity with SN 1987A

    Science.gov (United States)

    Zukin, Phillip; Bertschinger, Edmund

    2009-05-01

    In the 1950's, Papapetrou found that extended bodies with spin, in general relativity, do not move along geodesics because of a spin-curvature coupling. Using an Eikonal approximation, we reproduce these results for Dirac and Majorana particles. We generalize these results to modified theories of gravity with a non-minimally coupled matter lagrangian and place constraints on the coupling field based on the arrival times of SN 1987A neutrinos.

  11. Linear polarimetric study of SN 1987A

    Science.gov (United States)

    Clocchiatti, A.; Mendez, M.; Benvenuto, O.; Feinstein, C.; Marraco, H.

    Linear polarization measurements of SN 1987A were made with 0.83-m and a 2.15-m telescopes. It is found that the polarization decreases with time (Benvenuto et al., 1987) Because the polarization produced by the interstellar matter is time independent and the wavelength dependence of the observed polarization is far from the interstellar relation (Serkowski et al., 1975) it is suggested that the time dependent characteristic is due to an intrinsic polarization vector.

  12. VERY LATE PHOTOMETRY OF SN 2011fe

    Energy Technology Data Exchange (ETDEWEB)

    Kerzendorf, W. E. [Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, ON M5S 3H4 (Canada); Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J., E-mail: wkerzendorf@gmail.com [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany)

    2014-12-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ≈930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of {sup 56}Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs.

  13. Proton-neutron correlations above 100Sn

    Science.gov (United States)

    Delion, Doru S.; Baran, Virgil V.

    2017-06-01

    Proton-neutron (pn) correlations in nuclei above the Z=50 shell closure are investigated in order to understand the peculiar behaviour of the 2+ and 4+ states in Te and Xe isotopes. It turns out that by increasing the pn pairing interaction, which becomes important for N ≈ Z nuclei, the collectivity decreases. We thus conclude that the ratio between the B(E2) value and 2+ energy is a "fingerprint" of pn collectivity. The available experimental data indeed indicate an enhanced pn pairing interaction by also approaching double magic Z=N=20 and Z=N=28 regions. It is known that the α-particle reduced width has the largest values in the region above 100Sn. In order to reproduce the reduced α-decay width we use an additional pocket-like surface potential in the single particle mean field, simulating four-body correlations. The strength of this interaction has a universal linear dependence on the experimental reduced width above the double magic nuclei 100Sn and 208Pb. Moreover, we demonstrate that pn pairing correlations have a small influence on this dependence and therefore cannot explain the larger reduced decay widths above 100Sn.

  14. Thermoelectric properties of SnSe compound

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Lu, Pengfei, E-mail: photon@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wu, Liyuan; Han, Lihong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Liu, Gang [School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Song, Yuxin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2015-09-15

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data.

  15. Very late photometry of SN 2011fe

    CERN Document Server

    Kerzendorf, W E; Seitenzahl, I R; Ruiter, A J

    2014-01-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (> 900 d) of thermonuclear supernovae. These late stages allow for a direct measurement of the decay processes of nuclei synthesized in the core of the explosion. In this paper, we present our photometric data of SN 2011fe taken at an unprecedentedly late epoch of ~ 930 d with GMOS-N mounted on the Gemini North telescope (g=23.37+/- 0.25, r=24.03 +/- 0.09, i=23.90 +/- 0.15, and z=23.74 +/- 0.16) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of 56Co. This is in spite of several theoretical predictions that advocate a substantial energy redistribution and/or loss via various processes wh...

  16. The Radio Evolution of SN 2001gd

    CERN Document Server

    Stockdale, Christopher J; Weiler, Kurt W; Panagia, Nino; Sramek, Richard A; Van Dyk, Schuyler D; Kelley, Matthew T

    2007-01-01

    We present the results of observations of the radio emission from Supernova 2001gd in NGC 5033 from 2002 February 8 through 2006 September 25. The data were obtained using the Very Large Array at wavelengths of 1.3 cm (22.4 GHz), 2 cm (14.9 GHz), 3.6 cm (8.4 GHz), 6 cm (4.9 GHz), and 20 cm (1.5 GHz), with one upper limit at 90 cm (0.3 GHz). In addition, one detection has been provided by the Giant Metrewave Radio Telescope at 21 cm (1.4 GHz). SN 2001gd was discovered in the optical well past maximum light, so that it was not possible to obtain many of the early radio "turn-on" measurements which are important for estimating the local circumstellar medium (CSM) properties. Only at 20 cm were turn-on data available. However, our analysis and fitting of the radio light curves, and the assumption that the Type IIb SN 2001gd resembles the much better studied Type IIb SN 1993J, enables us to describe the radio evolution as being very regular through day ~550 and consistent with a nonthermal-emitting model with a th...

  17. SALT spectroscopic classification of PS16efm (= SN 2016fxu) as a type-Ic supernova after maximum light

    Science.gov (United States)

    Jha, S. W.; Dettman, K.; Pan, Y.-C.; Foley, R. J.; Rest, A.; Scolnic, D.; Kotze, M.

    2016-09-01

    We obtained SALT (+RSS) spectroscopy of PS16efm (= SN 2016fxu) on 2016 Sep 8.0 UT, covering the wavelength range 350-920 nm. Cross-correlation of the spectrum with a template library using SNID (Blondin & Tonry 2007, ApJ, 666, 1024) shows PS16efm is a type-Ic supernova approximately two to three weeks past maximum light.

  18. A facile inexpensive route for SnS thin film solar cells with SnS{sub 2} buffer

    Energy Technology Data Exchange (ETDEWEB)

    Gedi, Sreedevi [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Minna Reddy, Vasudeva Reddy, E-mail: drmvasudr9@gmail.com [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Pejjai, Babu [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Park, Chinho, E-mail: chpark@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Ramakrishna Reddy, K.T., E-mail: ktrkreddy@gmail.com [Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India)

    2016-05-30

    Graphical abstract: PYS spectra of SnS/SnS{sub 2} interface and the related band diagram. - Highlights: • A low cost SnS solar cell is developed using chemical bath deposition. • We found E{sub I} & χ of SnS (5.3 eV & 4.0 eV) and SnS{sub 2} (6.9 eV & 4.1 eV) films from PYS. • Band offsets of 0.1 eV (E{sub c}) and 1.6 eV (E{sub v}) are estimated for SnS/SnS{sub 2} junction. • SnS based solar cell showed a conversion efficiency of 0.51%. - Abstract: Environment-friendly SnS based thin film solar cells with SnS{sub 2} as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS{sub 2} films were polycrystalline; (1 1 1)/(0 0 1) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS{sub 2} films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS{sub 2} films. The band alignment of SnS/SnS{sub 2} junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density–voltage (J–V) measurements of the cell showed open circuit voltage (V{sub oc}) of 0.12 V, short circuit current density (J{sub sc}) of 10.87 mA cm{sup −2}, fill factor (FF) of 39% and conversion efficiency of 0.51%.

  19. Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

    DEFF Research Database (Denmark)

    Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.;

    1998-01-01

    For microelectronics and especially for upcoming new packaging technologies in micromechanics and photonics fluxless, reliable and economic soldering technologies are needed. In this article, we consequently focus on the oxidation and reduction kinetics of three commonly used eutectic solder allo...... and reflowed AuSn(80/20) and SnPb(60/40) after the introduction of H2...

  20. Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

    Science.gov (United States)

    Takahashi, Junichi; Nakahara, Sumio; Hisada, Shigeyoshi; Fujita, Takeyoshi

    2004-10-01

    It has reported that a waste of an electronics substrate including lead and its compound such as 63Sn-37Pb has polluted the environment with acid rain. For that environment problem the development of lead-free solder alloys has been promoted in order to find out the substitute for Sn-Pb solders in the United States, Europe, and Japan. In a present electronics industry, typical alloys have narrowed down to Sn-Ag-Cu and Sn-Zn lead-free solder. In this study, solderability of Pb-free solder that are Sn-Ag-Cu and Sn-Zn-Bi alloy was studied on soldering using YAG (yttrium aluminum garnet) laser and diode laser. Experiments were peformed in order to determine the range of soldering parameters for obtaining an appropriate wettability based on a visual inspection. Joining strength of surface mounting chip components soldered on PCB (printed circuit board) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics of eutectic Sn-Pb alloy and under different power density were examined. As a result, solderability of Sn-Ag-Cu (Pb-free) solder paste are equivalent to that of coventional Sn-Pb solder paste, and are superior to that of Sn-Zn-Bi solder paste in the laser soldering method.

  1. Ultrasonic spray pyrolysis deposition of SnSe and SnSe2 using a single spray solution

    Institute of Scientific and Technical Information of China (English)

    Jorge Sergio Narro-Rios; Manoj Ramachandran; Dalia Martínez-Escobar; Aarón Sánchez-Juárez

    2013-01-01

    Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis (USP) technique.To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution.The use of a single spray solution for obtaining both a p-type material,SnSe,and an n-type material,SnSe2,simplifies the deposition technique.The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV.The Hall measurements were used to determine the resistivity of the thin films.The SnSe2 thin films show a resistivity of 36.73 Ω·cm and n-type conductivity while the SnSe thin films show a resistivity of 180 Ω·cm and p-type conductivity.

  2. Low-Temperature Solution-Processed SnO2 Nanoparticles as a Cathode Buffer Layer for Inverted Organic Solar Cells.

    Science.gov (United States)

    Tran, Van-Huong; Ambade, Rohan B; Ambade, Swapnil B; Lee, Soo-Hyoung; Lee, In-Hwan

    2017-01-18

    SnO2 recently has attracted particular attention as a powerful buffer layer for organic optoelectronic devices due to its outstanding properties such as high electron mobility, suitable band alignment, and high optical transparency. Here, we report on facile low-temperature solution-processed SnO2 nanoparticles (NPs) in applications for a cathode buffer layer (CBL) of inverted organic solar cells (iOSCs). The conduction band energy of SnO2 NPs estimated by ultraviolet photoelectron spectroscopy was 4.01 eV, a salient feature that is necessary for an appropriate CBL. Using SnO2 NPs as CBL derived from a 0.1 M precursor concentration, P3HT:PC60BM-based iOSCs showed the best power conversion efficiency (PCE) of 2.9%. The iOSC devices using SnO2 NPs as CBL revealed excellent long-term device stabilities, and the PCE was retained at ∼95% of its initial value after 10 weeks in ambient air. These solution-processed SnO2 NPs are considered to be suitable for the low-cost, high throughput roll-to-roll process on a flexible substrate for optoelectronic devices.

  3. Stearic acids at sn-1, 3 positions of TAG are more efficient at limiting fat deposition than palmitic and oleic acids in C57BL/6 mice.

    Science.gov (United States)

    Gouk, Shiou-Wah; Cheng, Sit-Foon; Ong, Augustine Soon-Hock; Chuah, Cheng-Hock

    2014-04-14

    In the present study, we investigated the effect of long-acyl chain SFA, namely palmitic acid (16:0) and stearic acid (18:0), at sn-1, 3 positions of TAG on obesity. Throughout the 15 weeks of the experimental period, C57BL/6 mice were fed diets fortified with cocoa butter, sal stearin (SAL), palm mid fraction (PMF) and high-oleic sunflower oil (HOS). The sn-1, 3 positions were varied by 16:0, 18:0 and 18:1, whilst the sn-2 position was preserved with 18:1. The HOS-enriched diet was found to lead to the highest fat deposition. This was in accordance with our previous postulation. Upon normalisation of total fat deposited with food intake to obtain the fat:feed ratio, interestingly, mice fed the SAL-enriched diet exhibited significantly lower visceral fat/feed and total fat/feed compared with those fed the PMF-enriched diet, despite their similarity in SFA-unsaturated fatty acid-SFA profile. That long-chain SFA at sn-1, 3 positions concomitantly with an unsaturated FA at the sn-2 position exert an obesity-reducing effect was further validated. The present study is the first of its kind to demonstrate that SFA of different chain lengths at sn-1, 3 positions exert profound effects on fat accretion.

  4. Magnetization study of ITER-type internal-Sn Nb3Sn superconducting wire

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao-Wu; Zhou Lian; Andre Sulpice; Jean-Louis Soubeyroux; Christophe Verwaerde; Gia Ky Hoang; Zhang Ping-Xiang; Lu Ya-Feng; Tang Xian-De

    2007-01-01

    Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor (ITER)-type internal-Sn Nb3Sn superconducting wire has been investigated. The irreversibility temperature T*(H), which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width △M(H) which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated samples show that the combination of T*(H) with △M(H) measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675 ℃/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.

  5. Intermediate-energy Coulomb excitation of 104Sn: Moderate E2 strength decrease approaching 100Sn

    CERN Document Server

    Doornenbal, P; Aoi, N; Matsushita, M; Obertelli, A; Steppenbeck, D; Wang, H; Audirac, L; Baba, H; Bednarczyk, P; Boissinot, S; Ciemala, M; Corsi, A; Furumoto, T; Isobe, T; Jungclaus, A; Lapoux, V; Lee, J; Matsui, K; Motobayashi, T; Nishimura, D; Ota, S; Pollacco, E C; Sakurai, H; Santamaria, C; Shiga, Y; Sohler, D; Taniuchi, R

    2013-01-01

    The reduced transition probability B(E2) of the first excited 2+ state in the nucleus 104Sn was measured via Coulomb excitation in inverse kinematics at intermediate energies. A value of 0.163(26) e^2b^2 was extracted from the absolute cross-section on a Pb target, while the method itself was verified with the stable 112Sn isotope. Our result deviates significantly from the earlier reported value of 0.10(4) e^2b^2 and corresponds to a moderate decrease of excitation strength relative to the almost constant values observed in the proton-rich, even-A 106-114Sn isotopes. Present state-of-the-art shell-model predictions, which include proton and neutron excitations across the N=Z=50 shell closures as well as standard polarization charges, underestimate the experimental findings

  6. Atomic transport properties of Ag xSn 1-x liquid binary alloys

    Science.gov (United States)

    Bhuiyan, E. H.; Ziauddin Ahmed, A. Z.; Bhuiyan, G. M.; Shahjahan, M.

    2008-05-01

    Atomic transport properties, in particular the shear viscosity and diffusion constants for Ag xSn 1-x less simple liquid binary alloys are theoretically studied from a statistical mechanical theory called the distribution function method. The essential ingredients of this theory are the interionic interaction and the pair distribution function for hard spheres. The interionic interaction are described from a local pseudopotential model and the effective hard sphere diameters are obtained from the thermodynamic perturbative method known as the linearized Weeks-Chandler-Andersen (LWCA). Results of calculations for shear viscosities agree well with the available experimental data.

  7. Parametrized dielectric functions of amorphous GeSn alloys

    Science.gov (United States)

    D'Costa, Vijay Richard; Wang, Wei; Schmidt, Daniel; Yeo, Yee-Chia

    2015-09-01

    We obtained the complex dielectric function of amorphous Ge1-xSnx (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge0.75Sn0.25 and Ge0.50Sn0.50 alloys from literature. The compositional dependence of band gap energy Eg and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  8. Weekly Fleet Assignment Model and Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHU Xing-hui; ZHU Jin-fu; GONG Zai-wu

    2007-01-01

    A 0-1 integer programming model for weekly fleet assignment was put forward based on linear network and weekly flight scheduling in China. In this model, the objective function is to maximize the total profit of fleet assignment, subject to the constraints of coverage, aircraft flow balance, fleet size, aircraft availability, aircraft usage, flight restriction, aircraft seat capacity,and stopover. Then the branch-and-bound algorithm based on special ordered set was applied to solve the model. At last, a realworld case study on an airline with 5 fleets, 48 aircrafts and 1 786 flight legs indicated that the profit increase was $1591276 one week and the running time was no more than 4 min, which shows that the model and algorithm are fairly good for domestic airline.

  9. Vehicle Technologies Fact of the Week 2013

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Stacy Cagle [ORNL; Williams, Susan E [ORNL; Moore, Sheila A [ORNL; Boundy, Robert Gary [ORNL

    2014-03-01

    Each week the U.S. Department of Energy s Vehicle Technology Office (VTO) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/ . These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current week s Fact is available on the VTO homepage, but older Facts are archived and still available at: http://www1.eere.energy.gov/vehiclesandfuels/facts/. This report is a compilation of the Facts that were posted during calendar year 2013. The Facts were written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.

  10. VizieR Online Data Catalog: SN 2009dc BVRI light curves (Silverman+, 2011)

    Science.gov (United States)

    Silverman, J. M.; Ganeshalingam, M.; Li, W.; Filippenko, A. V.; Miller, A. A.; Poznanski, D.

    2011-08-01

    Observations of SN 2009dc began on 2009 Apr. 17, about one week before maximum B-band brightness, in BVRI filters using the 0.76-m Katzman Automatic Imaging Telescope (KAIT) and the 1-m Nickel telescope, both at Lick Observatory. We continued to follow SN 2009dc for over 5 months until 2009 Sept. 26, when it reached the western limit of both telescopes in the early evening. We obtained late-time gVRI images of SN 2009dc using the dual-arm Low-Resolution Imaging Spectrometer (LRIS) with the 10-m Keck I telescope on 2010 Feb. 6 (281d past maximum), BRI images using the DEIMOS spectrograph (Faber et al. 2003) mounted on the 10-m Keck II telescope on 2010 Jun. 12 (403d past maximum) and V-band images again using LRIS on 2010 Jun. 13. Our optical photometry is complemented with data taken from the UltraViolet Optical Telescope (UVOT) on the Swift Observatory in the U, B, V, UVW1, UVM2 and UVW2 filters. We downloaded seven epochs of observations from the Swift archives. (2 data files).

  11. SN 2013ab : A normal type IIP supernova in NGC 5669

    CERN Document Server

    Bose, Subhash; Misra, Kuntal; Pumo, Maria Letizia; Zampieri, Luca; Sand, David; Kumar, Brijesh; Pastorello, Andrea; Sutaria, Firoza; Maccarone, Thomas J; Kumar, Brajesh; Graham, M L; Howell, D Andy; Ochner, Paolo; Chandola, H C; Pandey, Shashi B

    2015-01-01

    We present densely-sampled ultraviolet/optical photometric and low-resolution optical spectroscopic observations of the type IIP supernova 2013ab in the nearby ($\\sim$24 Mpc) galaxy NGC 5669, from 2 to 190d after explosion. Continuous photometric observations, with the cadence of typically a day to one week, were acquired with the 1-2m class telescopes in the LCOGT network, ARIES telescopes in India and various other telescopes around the globe. The light curve and spectra suggest that the SN is a normal type IIP event with a plateau duration of $ \\sim80 $ days with mid plateau absolute visual magnitude of -16.7, although with a steeper decline during the plateau (0.92 mag 100 d$ ^{-1} $ in $ V $ band) relative to other archetypal SNe of similar brightness. The velocity profile of SN 2013ab shows striking resemblance with those of SNe 1999em and 2012aw. Following the Rabinak & Waxman (2011) prescription, the initial temperature evolution of the SN emission allows us to estimate the progenitor radius to be...

  12. MGMT 520 FINAL EXAM Week 8

    OpenAIRE

    Laynebaril

    2017-01-01

    MGMT 520 FINAL EXAM Week 8       Click Link Below To Buy:     http://hwcampus.com/shop/mgmt-520-final-exam-week-8/             (TCOs G and I) In the 1930s, after immigrating to the U.S. from a region in central Europe threatened by the onset of World War II, Luigi and Maria Spongee opened a bakery in Chicago. They specialized in snack cakes. Spongee Cup Cakes became so popular in the area that the family stopped being actual bakers and becam...

  13. EDU 382 Week 5 Final Paper Requirements

    OpenAIRE

    Laynebaril

    2017-01-01

    EDU 382 Week 5 Final Paper Requirements Click Link Below To Buy:   http://hwcampus.com/shop/edu-382-week-5-final-paper/ Or Visit www.hwcampus.com   Lesson Plan Revision and Analysis [CLOs: 1, 2, 3, 4]. Due by Day 7. For the final assignment, you will select among one of three lesson plans where you will differentiate the given lesson plan based on student readiness, student interest, and student learning profile for content, process, and product. You will then evaluate...

  14. Ordered CoSn-type ternary phases in Co3Sn3-xGex

    DEFF Research Database (Denmark)

    Allred, Jared M.; Jia, Shuang; Bremholm, Martin;

    2012-01-01

    CoSn is the prototype compound of the B35 structure, which has long been of interest due to its rarity and unusually low packing density. We report the synthesis and properties of the solid solution Co3Sn3-xGex for 0 ⩽ x ⩽ 2, in order to clarify the conditions necessary to stabilize such a phase...... some ambiguities about the stabilizing forces in this crystal structure. All compounds are normal metals with room temperature conductivities ranging from 5 to 50 μΩ cm and are weakly paramagnetic....

  15. Bulk and surface properties of demixing liquid Al-Sn and Sn-Tl alloys

    Science.gov (United States)

    Odusote, Y. A.; Popoola, A. I.; Oluyamo, S. S.

    2016-02-01

    The energetics of mixing in Al-Sn and Sn-Tl-segregating binary alloys has been explained through the study of surface properties (surface concentrations and surface tension) and various concentration-dependent thermodynamic (free energy of mixing, entropy of mixing and enthalpy of mixing) and transport (chemical diffusion) properties as well as the microscopic functions (concentration fluctuations in the long-wavelength limits and chemical short-range order parameter) using a statistical mechanical theory in conjunction with the self-association model (SAM). The theoretical property values obtained by the SAM were compared to the corresponding experimental values available in literature.

  16. MERLIN radio observations of two recent supernovae in Arp299: SN2010O & SN2010P

    Science.gov (United States)

    Beswick, R. J.; Perez-Torres, M. A.; Mattila, S.; Garrington, S. T.; Kankare, E.; Ryder, S.; Alberdi, A.; Romero-Canizales, C.

    2010-02-01

    We report MERLIN radio observations of the two recent supernovae in Arp299; SN2010P and SN2010O (CBET #2145 and CBET #2144, respectively). Observations of Arp299 were made between 1900UT 29th Jan 2010 and 0150UT 1st Feb 2010 at 4994MHz. The previously known compact radio structure of Arp299, including the nuclear starburst components associated with A=IC694 and B1=the southernmost nucleus of NGC3690 are detected (Neff, Ulvestad & Teng 2004, ApJ, 611, 186; Ulvestad 2009 AJ, 138, 152; Perez-Torres et al 2009, A&A 507, 17).

  17. Structural properties and hyperfine characterization of Sn-substituted goethites

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, A.L. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Ramos, C.P. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Arcondo, B. [Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Bs. As. (Argentina); Tufo, A.E. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Saragovi, C. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Sileo, E.E., E-mail: sileo@qi.fcen.uba.ar [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Pure and tin-doped goethites were synthesized from Sn(II) solutions at ambient pressure and 70 Degree-Sign C. Black-Right-Pointing-Pointer The Rietveld refinement of PXRD data indicated that Sn partially substituted the Fe(III) ions. Black-Right-Pointing-Pointer The substitution provoked unit cell expansion, and a distortion of the coordination polyhedron. Black-Right-Pointing-Pointer {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV). Black-Right-Pointing-Pointer {sup 57}Fe Moessbauer spectroscopy showed a lower magnetic coupling as tin concentration increased. - Abstract: Tin-doped goethites obtained by a simple method at ambient pressure and 70 Degree-Sign C were characterized by inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, Rietveld refinement of powder X-ray diffraction data, and {sup 57}Fe and {sup 119}Sn Moessbauer spectroscopy. The particles size and the length to width ratios decreased with tin-doping. Sn partially substituted the Fe(III) ions provoking unit cell expansion and increasing the crystallinity of the particles with enlarged domains that grow in the perpendicular and parallel directions to the anisotropic broadening (1 1 1) axis. Intermetallic E, E Prime and DC distances also change although the variations are not monotonous, indicating different variations in the coordination polyhedron. In general, the Sn-substituted samples present larger intermetallic distances than pure goethite, and the greatest change is shown in the E Prime distance which coincides with the c-parameter. {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV) in the samples. On the other hand, Fe(II) presence was not detected by {sup 57}Fe Moessbauer spectroscopy, suggesting the existence of vacancies in the Sn-doped samples. A lower magnetic coupling is also evidenced from the average magnetic hyperfine field values obtained as tin

  18. Expression of the System N transporter (SNAT5/SN2) during development indicates its plausible role in glutamatergic neurotransmission.

    Science.gov (United States)

    Rodríguez, Angelina; Ortega, Arturo; Berumen, Laura C; García-Alcocer, María G; Giménez, Cecilio; Zafra, Francisco

    2014-07-01

    Solute neutral amino acid transporter 5 (SNAT5/SN2) is a member of the System N family, expressed in glial cells in the adult brain, able to transport glutamine, histidine or glycine among other substrates. Its tight association with synapses and its electroneutral mode of operation that allows the bidirectional movement of substrates, supports the idea that this transporter participates in the function of the glutamine-glutamate cycle between neurons and glia. Moreover, SNAT5/SN2 might contribute to the regulation of glycine concentration in glutamatergic synapses and, therefore, to the functioning of the N-methyl-d-aspartate (NMDA) subtype of glutamate receptors. Ontogenic maturation of these synapses occurs postnatally through the coordinate expression of a large number of receptors, transporters, structural and regulatory proteins that ensure the correct operation of the excitatory pathways in the central nervous system. Since the temporal pattern of expression of SNAT5/SN2 is unknown, we analyzed it by immunoblot and immunohistochemical techniques. Results indicate that the expression of SNAT5/SN2 is triggered between the second and third postnatal week in the cerebral cortex, in parallel to the expression of the vesicular glutamate transporter vGLUT1 and the glial glutamate transporter GLT1/EAAT2. In the cerebellum, this process occurs about one week later than in the cerebral cortex. Immunohistochemical staining of cortical sections shows that from postnatal day 14 to adulthood the transporter was expressed exclusively in glial cells. Our results are consistent with the idea that SNAT5/SN2 expression is coordinated with that of other proteins necessary for the operation of glutamatergic synapses and reinforce the existence of a regulatory cross-talk between neurons and glia that orchestrates the building up of these synapses.

  19. VizieR Online Data Catalog: Optical and UV photometry of SN 2013dy (Zhai+, 2016)

    Science.gov (United States)

    Zhai, Q.; Zhang, J.-J.; Wang, X.-F.; Zhang, T.-M.; Liu, Z.-W.; Brown, P. J.; Huang, F.; Zhao, X.-L.; Chang, L.; Yi, W.-M.; Wang, C.-J.; Xin, Y.-X.; Wang, J.-G.; Lun, B.-L.; Zhang, X.-L.; Fan, Y.-F.; Zheng, X.-M.; Bai, J.-M.

    2016-08-01

    SN2013dy, an Type Ia supernova (SNIa), was discovered at roughly a magnitude of ~17.2mag on UT July 10.45 2013 (Universal Time) in an unfiltered image of the galaxy NGC7250 by the Lick observatory supernova search (Casper et al., 2013CBET.3588....1C). Our first observation of SN 2013dy is in spectroscopy on 2013 July 14 (Zhang & Wang 2013CBET.3394....1Z; 4.76days after the first light and published in Zheng et al. 2013ApJ...778L..15Z) with the Yunnan Faint Object Spectrograph and Camera (YFOSC) mounted at the Li-Jiang 2.4m Telescope (LJT) of Yunnan Observatories (YNAO), China. About two weeks later, we started to monitor this transient intensively at LJT in both ground-based UBVRI photometry and spectroscopy spanning from t~+0 to t~+180days. Ten local standard stars (see Table1 in the paper) in the field of SN2013dy are used to transform the instrumental magnitudes of SN2013dy to the standard Johnson UBV and Kron-Cousins RI system, as listed in Table2. Optical photometry data are also collected with the Tsinghua-NAOC 0.8m telescope (TNT) at Xing-Long Observation of National Astronomical Observatories (NAOC), China, from t~-2days to t~+150days. Additionally, three spectra were obtained at the Xing-Long 2.16 m telescope (hereafter XLT) with the Bei-Jing Faint Object Spectrograph and Camera (BFOSC). Furthermore, this target was also observed by the Ultra-Violet/Optical Telescope (UVOT) on board the Swift satellite. The Swift observatory began observing SN 2013dy on 2013 July 17.09, about 10days (t~-10days) before the B band maximum, and continued for approximately 26days (t~+15days). These photometric observations are performed in three UV filters (uvw2, uvm2, and uvw1) and three broadband optical filters (uu, bb, and vv). Table3 lists the final UVOT UV/optical magnitudes of SN2013dy. (2 data files).

  20. Real-time study of electromigration in Sn Blech structure

    Science.gov (United States)

    Ho, C. E.; Hsieh, W. Z.; Yang, C. H.; Lee, P. T.

    2016-12-01

    Electromigration has become a critical issue for reliability in Sn-based conducting materials that are used in advanced microelectronic packages with micro-joint integration. In this study, a Blech structure was used to characterize the Sn electromigration behavior of various strip lengths (L0 = 10-100 μm). We established a mathematical model based on the fundamental electromigration theory to describe the correlation between the residual strip length (L) and the current stressing time (t). A three-stage mechanism was proposed to rationalize the Sn electromigration in the Blech structure. A good agreement between the mathematical model and experimental data was obtained, advancing our understanding of Sn electromigration.

  1. GeSn/Ge multiquantum well photodetectors on Si substrates.

    Science.gov (United States)

    Oehme, M; Widmann, D; Kostecki, K; Zaumseil, P; Schwartz, B; Gollhofer, M; Koerner, R; Bechler, S; Kittler, M; Kasper, E; Schulze, J

    2014-08-15

    Vertical incidence GeSn/Ge multiquantum well (MQW) pin photodetectors on Si substrates were fabricated with a Sn concentration of 7%. The epitaxial structure was grown with a special low temperature molecular beam epitaxy process. The Ge barrier in the GeSn/Ge MQW was kept constant at 10 nm. The well width was varied between 6 and 12 nm. The GeSn/Ge MQW structures were grown pseudomorphically with the in-plane lattice constant of the Ge virtual substrate. The absorption edge shifts to longer wavelengths with thicker QWs in agreement with expectations from smaller quantization energies for the thicker QWs.

  2. The high-temperature modification of LuAgSn and high-pressure high-temperature experiments on DyAgSn, HoAgSn, and YbAgSn

    Energy Technology Data Exchange (ETDEWEB)

    Heying, B.; Rodewald, U.C.; Hermes, W.; Schappacher, F.M.; Riecken, J.F.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Muenchen Univ. (Germany). Dept. fuer Chemie und Biochemie; Sebastian, C.P. [Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany)

    2008-02-15

    The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P6{sub 3}mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F{sup 2}, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag{sub 3}Sn{sub 3}] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag{sub 3}Sn{sub 3}] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F{sup 2}, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F{sup 2}, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with {mu}{sub eff} = 7.53(1) {mu}{sub B}/Tm atom and {theta}P = -15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature {sup 119}Sn Moessbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively. (orig.)

  3. Cajal bodies and snRNPs - friends with benefits.

    Science.gov (United States)

    Staněk, David

    2016-09-14

    Spliceosomal snRNPs are complex particles that proceed through a fascinating maturation pathway. Several steps of this pathway are closely linked to nuclear non-membrane structures called Cajal bodies. In this review, I summarize the last 20 y of research in this field. I primarily focus on snRNP biogenesis, specifically on the steps that involve Cajal bodies. I also evaluate the contribution of the Cajal body in snRNP quality control and discuss the role of snRNPs in Cajal body formation.

  4. Elastic anisotropy in multifilament Nb$_3$Sn superconducting wires

    CERN Document Server

    Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

    2015-01-01

    The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

  5. Effect of pressure on the Curie temperature of Mn2RuSn and Mn2PdSn

    Science.gov (United States)

    Adachi, Y.; Watanabe, T.; Kanomata, T.; Hayasaka, M.; Endo, K.; Nishihara, H.; Xu, X.; Kainuma, R.

    2017-04-01

    Effect of pressure on the Curie temperature TC of the Mn-rich Heusler alloys Mn2RuSn and Mn2PdSn has been investigated by measuring the temperature dependence of initial permeability at various pressures up to 10 kbar. It was found that the Curie temperatures of Mn2RuSn and Mn2PdSn decrease with increasing pressure. The pressure derivatives of TC were estimated to be -0.59 K/kbar for Mn2RuSn and -0.80 K/kbar for Mn2PdSn. On the basis of the experimental results, the relationship between the magnetic transition temperature and the Mn-Mn distance is discussed.

  6. The attack initiation of Al-Zn-In-Sn anode by the segregation concentrating Zn,Sn and In

    Energy Technology Data Exchange (ETDEWEB)

    Qi, G.T.; Qiu, Y.B.; Cai, Q.Z. [Department of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan (China); Zhao, Y.N. [Department of Biological and Chemical Engineering, Nanyang Institute of Technology, Nanyang (China)

    2009-03-15

    The microstructure of Al-5%Zn-0.025%In-0.15%Sn anode was investigated by EPMA, and EDAX. The result showed that the microstructure at the Al-Zn-In-Sn anode can be categorized into two different types, namely the catenulate segregation enriched in Zn, Fe, Si, and the elliptical or rounded segregation where Zn, Sn, In concentrated. In order to explain the initial dissolution of the aluminum anode, the electrochemical behavior in 3% NaCl solution of the Al-Zn-In-Sn anode and its simulated segregation concentrating Zn, Sn, In were tested using potentiodynamic polarization and electrochemical impedance spectroscopy. The result showed that the simulated segregation concentrating Zn,Sn, In would preferentially be dissolved into the solution as the anode of galvanic cell. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  7. Effect of Pt:Sn atomic ratio on the preparation of PtSn/C electrocatalysts using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V., E-mail: dfsilva@ipen.b, E-mail: espinace@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    PtSn/C electrocatalysts were prepared with Pt:Sn atomic ratios of 3:1, 1:1 and 1:3 in water/2-propanol using electron beam irradiation. The obtained materials were characterized by EDX, XRD and cyclic voltammetry. The ethanol electro-oxidation was studied by chronoamperometry. The XRD diffractograms of the PtSn/C electrocatalysts showed typical face-centered cubic (fcc) structure of platinum and the presence of a SnO{sub 2} phase (cassiterite). The mean crystallite sizes of Pt fcc phase was in the range of 3.0-3.5 nm. The PtSn/C electrocatalysts were active for ethanol electro-oxidation at room temperature and the material prepared with Pt:Sn atomic ratio of 1:1 showed the best activity. (author)

  8. 78 FR 62305 - Fire Prevention Week, 2013

    Science.gov (United States)

    2013-10-16

    ... safeguard their homes by clearing flammable vegetation, and they should plan for emergencies by building a... rapidly and poisonous, disorienting smoke moves even quicker, families should design plans that allow for... themselves in the paths of unpredictable wildfires, and rush into houses on the verge of collapse. This week...

  9. 76 FR 72601 - National Family Week, 2011

    Science.gov (United States)

    2011-11-23

    ... dreams. This week, we celebrate the threads of compassion and unity that tie our families together... excel in the global economy. And by taking executive action to lighten financial burdens on many middle... two hundred and thirty-sixth. (Presidential Sig.) [FR Doc. 2011-30454 Filed 11-22-11; 11:15...

  10. Beijing International Fashion Brand Promotion Week Opened

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Under the support of China National Garment Association,Beijing Municipal Bureau of Industrial Development, France Advanced Fashion Institute, Fashion Beijing Expo Organizing Committee and Beijing Fashion Textile Industry Association organized 2006 Autumn & Winter Beijing International Fashion Brand Promotion Week in Beijing Asia Hotel from September 20 to 23.

  11. [Seventh National Population Week in Rwanda, 1993].

    Science.gov (United States)

    Munyanziza, B

    1993-08-01

    The 1993 National Population Week opened in the commune of Rutare on August 2 and ended in Gikongoro in the commune of Rwamiko on August 6. Its goal was to sensitize all levels of the population to Rwanda's demographic problems through an IEC (information, education, communication) program while respecting the individual liberty, and the moral and religious beliefs of couples. On the first day of the population education campaign, the mayors of each commune along with its elite presided over a meeting to discuss implementation of the campaign, the sociodemographic situation at the commune level (especially at the household level), and the importance of family planning in family health. During August 2-5 at the commune level, the communal elite and the abakangurambagas presided over sensitization meetings, conference-debates, educational discussions, home visits, theatrical sessions, songs and dances, orientation to health centers, and recruitment of family planning acceptors. On the last day, development technicians working in the commune, teachers, students, religious leaders, abakangurambagas, political party leaders, and mass media journalists, all of whom took part in the week's activities, met at the communal office to evaluate the week's activities and to amass resolutions and recommendations. The mayor closed the 1993 edition of the National Population Week after the evaluation.

  12. What to Do in Week One?

    Science.gov (United States)

    Wormeli, Rick

    2016-01-01

    Although teachers can build positive relationships with students throughout the school year, the first weeks are crucial, writes Wormeli. They set the tone and conditions for the year ahead, creating a more effective teaching and learning enterprise for everyone. Wormeli tells how, as a middle school teacher, he set a goal of learning the names of…

  13. 77 FR 62133 - Fire Prevention Week, 2012

    Science.gov (United States)

    2012-10-12

    ... Documents#0;#0; #0; #0;Title 3-- #0;The President ] Proclamation 8881 of October 5, 2012 Fire Prevention... Prevention Week, we resolve to protect ourselves, our families, and our communities from fires, and we honor... fire prevention and preparedness. Those who live in regions prone to wildfire can take action...

  14. Interfacial Reactions in the Ni/Sn- xZn/Cu Sandwich Couples

    Science.gov (United States)

    Yen, Yee-Wen; Lin, Chung-Yung; Lai, Mei-Ting; Chen, Wan-Ching

    2016-01-01

    The interfacial reactions in Ni/Sn- xZn/Cu sandwich couples which were reflowed at 270°C for 1 h and then aged at 160°C for 1-1000 h were investigated. When the 1000- μm-thick Sn-Zn alloy reacted with Ni and Cu in this couple, the results indicated that the (Ni, Cu)3Sn4, (Ni, Cu)5Zn21, and Ni5Zn21 phases were formed at Sn-1Zn/Ni, Sn-5Zn/Ni, and Sn-9Zn/Ni interfaces for 1 h reflowing, respectively. After 1000 h aging, each intermetallic compound (IMC) was converted to (Cu, Ni, Zn)6Sn5, (Ni, Cu, Sn)5Zn21/Ni5Zn21, and Ni5Zn21 (two layers) phases in the related couples. On the Cu side, the Cu6Sn5 phase in the Sn-1Zn/Cu interface and the Cu5Zn8 phase in the Sn-5Zn/Cu and Sn-9Zn/Cu interfaces were observed when the couple was reflowed at 270°C for 1 h. After 100 h aging, the (Cu, Ni, Zn)6Sn5, Cu5Zn8/(Cu, Zn)6Sn5, and Cu5Zn8 phases were formed at the Sn-1Zn/Cu, Sn-5Zn/Cu and Sn-9Zn/Cu interfaces. When the Sn-Zn alloy thickness was decreased to 500 μm, the (Cu, Ni, Zn)6Sn5 phase at the Sn-1Zn/Ni interface and the (Ni, Cu, Sn)5Zn21 phase at the Sn-5Zn/Ni and Sn-9Zn/Ni interfaces were observed after 1 h reflowing. When the couple was aged at 160°C for 1000 h, each IMC was converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Ni, Sn)Zn/Ni5Zn21 phases at the Sn-1Zn/Ni and Sn-(5, 9)Zn/Ni interfaces. (Cu, Ni, Zn)6Sn5 and Cu5Zn8 were, respectively, formed at the Sn-1Zn/Cu and Sn-(5, 9)Zn/Cu interfaces for 1 h reflowing. After 100 h aging, the IMCs were converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Zn)6Sn5 phases. This current study reveals that the IMC formation in Ni/(Sn- xZn)/Cu sandwich couples are very sensitive to the Zn concentration and thickness in Sn- xZn alloys.

  15. TREATMENT OF IRON DEFICIENCY ANEMIA IN CHILDREN BY IRON SUPPLEMENTATION TWICE WEEKLY AND WEEKLY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective The effect of intermittent iron supplementation weekly and twice weekly was studied in children with iron deficiency anemia(IDA). Methods Subjects were 58 children who were randomly divided into two groups. One group received a dosage of 2mg/kg Fe every 3d for 9 weeks. The other group received the same dose Fe once a week for 12 weeks. Results Hemoglobin and serum ferritin increased significantly after treatment in both groups (P <0.05), and zinc protoporphyrin decreased significantly (P <0. 05). But serum ferritin of both groups was different after 6 weeks of treatment (P <0. 01). The side effect of the group supplemented once every 3d was higher than that of the group once a week, but there was no statistically significant difference. Conclusion Iron sup plementation every 3d has a similar effect to once a week for treatment of IDA. The former should be used for the se rious patients for 6 weeks. The later should be used for infants and the patients whose resistance of intestines and stomach are not good.

  16. Influence of Sn concentration on the physical properties of CdO:Sn thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Galan, O.; Ruiz, C.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Sanchez-Gonzalez, Y. [EMPROTEL, Copextel, Carretera Prensa Latina km 111/2, Marianao, La Habana (Cuba); Arias-Carbajal, A. [Facultad de Quimica-IMRE, Universidad de La Habana, 10400 La Habana (Cuba); Contreras-Puente, G.; Tufino-Velazquez, M. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, 07738 Mexico, D.F. (Mexico)

    2006-12-15

    Sn doped cadmium oxide thin films were prepared on glass substrates by the spray pyrolysis (SP) method from a cadmium acetate aqueous solution. The Sn (IV) concentration in the solution was varied up to 2 wt%, keeping constant the other growth parameters. The structural, electrical and optical properties of the films were studied as a function of Sn concentration. The best results were obtained for CdO films doped with 1% Sn nominal concentration. The properties of these films are influenced by the air annealing performed at 450 C for 30-120 min. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Simultaneous polarization monitoring of SN2007uy and the axisymmetric SN2008D/XRF080109: isolating geometry from dust

    CERN Document Server

    Gorosabel, J; Castro-Tirado, A J; Agudo, I; Jelinek, M; Leon, S; Augusteijn, T; Fynbo, J P U; Hjorth, J; Michalowski, M J; Xu, D; Ferrero, P; Kann, D A; Klose, S; Rossi, A; Madrid, J P; LLorente, A; Bremer, M; Winters, J -M

    2008-01-01

    We report the results of an optical linear polarization monitoring carried out simultaneously for SN2007uy and SN2008D. The observations span 74.9 days, starting 3.6 days after the X-ray outburst of SN2008D and are distributed in 11 visits. For both SNe the polarization is dominated by the host galaxy interstellar polarization (HGIP), especially for SN2007uy. This fact is supported by 1.2 millimeter (mm) observations of NGC2770, carried out at and around the SN2008D position. The 1.2 mm data are consistent with no intrinsic emission from SN2008D and can be entirely explained by the NGC2770 dust emission. Comparing spectroscopic extinction values reported in the literature with the extinction derived from the 1.2 mm data, we conclude that the NGC2770 extinction distribution is heterogeneous. We report also a 3.3 mm flux detection at the SN2008D position, possibly due to the intrinsic SN emission, and not due to the dust. Despite the dominant HGIP, a statistical analysis of the distribution of the SN2008D Stoke...

  18. Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

    Science.gov (United States)

    Hart, John; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James

    2016-03-01

    Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

  19. Electrochemical properties of Ti-Ni-Sn materials predicted by {sup 119}Sn Mössbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ladam, A., E-mail: alix.ladam@univ-montp2.fr; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C. [Université de Montpellier, Institut Charles Gerhardt, UMR 5253 CNRS (France); Cenac-Morthe, C. [CNES, Service DCT/TV/El (France)

    2016-12-15

    The electrochemical activity of TiNiSn, TiNi {sub 2}Sn and Ti {sub 6}Sn {sub 5} compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti {sub 6}Sn {sub 5} by ball milling. The {sup 119}Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e {sub av}]. The values of [e {sub av}] are in the region of Li-rich Li-Sn alloys for Ti {sub 6}Sn {sub 5} and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e {sub av}] for Ti {sub 6}Sn {sub 5} and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  20. Creep and Mechanical Properties of Cu6Sn5 and (Cu,Ni)6Sn5 at Elevated Temperatures

    Science.gov (United States)

    Mu, Dekui; Huang, Han; McDonald, Stuart D.; Nogita, Kazuhiro

    2013-02-01

    Cu6Sn5 is the most common and important intermetallic compound (IMC) formed between Sn-based solders and Cu substrates during soldering. The Cu6Sn5 IMC exhibits significantly different thermomechanical properties from the solder alloys and the substrate. The progress of high-density three-dimensional (3D) electrical packaging technologies has led to increased operating temperatures, and interfacial Cu6Sn5 accounts for a larger volume fraction of the fine-pitch solder joints in these packages. Knowledge of creep and the mechanical behavior of Cu6Sn5 at elevated temperatures is therefore essential to understanding the deformation of a lead-free solder joint in service. In this work, the effects of temperature and Ni solubility on creep and mechanical properties of Cu6Sn5 were investigated using energy-dispersive x-ray spectroscopy and nanoindentation. The reduced modulus and hardness of Cu6Sn5 were found to decrease as temperature increased from 25°C to 150°C. The addition of Ni increased the reduced modulus and hardness of Cu6Sn5 and had different effects on the creep of Cu6Sn5 at room and elevated temperatures.

  1. Wettability of Sn-Zn, Sn-Ag-Cu and Sn-Bi-Cu Lead-free Solder Alloys with Copper Substrate%Sn-Zn,Sn-Ag-Cu和Sn-Bi-Cu无铅焊锡合金与铜的润湿性

    Institute of Scientific and Technical Information of China (English)

    张晓瑞; 汪春雷; 赵宏欣; 李建强; 袁章福

    2009-01-01

    采用静滴法对Sn-Zn,Sn-Ag-Cu Sn-Bi-Cu锡基合金在铜基板上的润湿性进行了研究.结果表明,Sn-Bi-Cu合金的润湿性良好,Sn-30Bi-0.5Cu合金在530 K时的接触角为26°,熔融的Sn-3Ag-0.5Cu共晶合金的接触角几乎不存在滞后性.锡基合金中添加Bi元素可提高合金的润湿性,添加Cu元素可有效防止溶铜发生.研究结果为无铅焊锡合金的应用提供了一定的理论依据.

  2. 'Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31.

    Science.gov (United States)

    Klein, Wilhelm; Jin, Hanpeng; Hlukhyy, Viktor; Fässler, Thomas F

    2015-07-01

    The crystal structure of the title compound was previously reported with composition 'Pd20Sn13' [Sarah et al. (1981 ▸). Z. Metallkd, 72, 517-520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6 were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtained via a solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2 type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3):0.62 (3). One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3a and 3b).

  3. `Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31

    Directory of Open Access Journals (Sweden)

    Wilhelm Klein

    2015-07-01

    Full Text Available The crystal structure of the title compound was previously reported with composition `Pd20Sn13' [Sarah et al. (1981. Z. Metallkd, 72, 517–520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6 were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtained via a solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2 type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3:0.62 (3. One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3a and 3b.

  4. THIRTY SEVEN WEEKS AND BEYOND MATERNAL AND FOETAL OUTCOME BY WEEK OF GESTATION

    Directory of Open Access Journals (Sweden)

    Geeta Jagannath

    2016-04-01

    Full Text Available BACKGROUND It was noted in 1951 that although pregnancies persisting beyond 300 days occurred less than 5% of the time, they accounted for 30% of perinatal deaths. In the most recent Technical Bulletin on post-term pregnancy, the American College of Obstetricians and Gynaecologists reiterated the threshold of 42 weeks of gestation as the definition of post-term pregnancy. Their continued use of 42 weeks is particularly surprising in the face of an abundance of research demonstrating that induction of labour at 41 weeks of gestation and beyond leads to lower rates of neonatal morbidity and lower rates of caesarean deliveries. Our study is to find out the prevalence of spontaneous onset of labour and prevalence of maternal and perinatal morbidity beyond 37 weeks of gestation up to 41 weeks. AIM OF THE STUDY Our study is to find out the prevalence of spontaneous onset of labour in full term pregnancy and prevalence of morbidity by week of gestation. SETTINGS AND DESIGN It is an observational study conducted in low risk full-term pregnant women to find out the prevalence of spontaneous onset of labour and their morbidity. METHODS AND MATERIALS The study was conducted during the period 1st of January 2014 to 31st December 2014 in the Department of OBG. The low risk pregnant women going into spontaneous labour between 37 weeks to 41 weeks were considered for the study. They were divided into 37-38 weeks, 39-40 weeks and 41 weeks. Statistical Analysis used was chi square test on SPSS 15. RESULTS There were 1098 women delivered during the study period, out of which 116 low risk pregnancy women who had spontaneous onset of labour from 37 weeks to 41 weeks were considered for the study. Sixty four percent had spontaneous onset of labour were at 39 to 40 weeks of gestation. Fifty three percent of patients were at the age of 26-30 years. Sixty nine percent of deliveries were multigravida. Fifty eight percent of labours were seen with the BMI of 19

  5. Thermodynamic understanding of Sn whisker growth on the Cu surface in Cu(top)-Sn(bottom) bilayer system upon room temperature aging

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lin; Jian, Wei; Lin, Bing; Wang, Jiangyong, E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China); Wen, Yuren [School of Materials Science and Engineering, Nanchang University, Nanchang, 330031 Jiangxi (China); Institute of Physics, Chinese Academy of Sciences, 100190 Beijing (China); Gu, Lin [Institute of Physics, Chinese Academy of Sciences, 100190 Beijing (China)

    2015-06-07

    Sn whiskers are observed by scanning electron microscope on the Cu surface in Cu(top)-Sn(bottom) bilayer system upon room temperature aging. Only Cu{sub 6}Sn{sub 5} phase appears in the X-ray diffraction patterns and no Sn element is detected in the Cu sublayer by scanning transmission electron microscopy. Based on the interfacial thermodynamics, the intermetallic Cu{sub 6}Sn{sub 5} compound phase may form directly at the Sn grain boundary. Driven by the stress gradient during the formation of Cu{sub 6}Sn{sub 5} compound at Sn grain boundaries, Sn atoms segregate onto the Cu surface and accumulate to form Sn whisker.

  6. Swift Observations of SN 2007aa

    Science.gov (United States)

    Immler, S.; Brown, P. J.; Milne, P.

    2007-03-01

    Swift Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) observed the type II SN 2007aa (CBET #850, IAUC #8814) on 2007-02-24.63 UT. The following UVOT magnitudes were measured: V = 15.8 (322 s exposure time), B = 16.4 (367 s), U = 16.9 (367 s), UVW1 [181-321nm] = 18.6 (737 s), UVM2 [166-268 nm] > 19.5 (3-sigma upper limit; 236 s), and UVW2 [112-264 nm] = 19.7 (725 s). The magnitudes have not been corrected for extinction.

  7. Spectroscopic observation of 5 SN candidates

    Science.gov (United States)

    Elias-Rosa, N.; Pursimo, T.; Korhonen, H.; Pastorello, A.; Derlopa, the NEON school PhD students S.; Marian, V.; Scognamiglio, D.; Szigeti, L.; Cabezas, M.; Fernandes, C. S.; McWhirter, P. R.; Zervas, K.

    2017-09-01

    We report the spectroscopic classification of SNe 2017gla, 2017glz, 2017gop, and 2017gqq, and the verification of SN2017gmr. The targets were supplied by the following surveys: ATLAS survey, see Tonry et al. (2011, PASP, 123, 58) and Tonry et al. (ATel #8680); Pan-STARRS Survey for Transients (Chambers et al. 2016, arXiv:1612.05560, and http://pswww.ifa.hawaii.edu ), the PMO-Tsinghua Supernova Survey (PTSS, http://www.cneost.org/ptss/ ); and the D The observations were performed with the 2.56 m Nordic Optical Telescope equipped with ALFOSC (range 350-950 nm; resolution 1.4 nm FWHM).

  8. Dose dense 1 week on/1 week off temozolomide in recurrent glioma: A retrospective study

    NARCIS (Netherlands)

    W. Taal (Walter); J.M.W. Segers-Van Rijn (Joyce M.); J.M. Kros (Johan); I. van Heuvel (Irene); C.C.D. van der Rijt (Carin); J.E.C. Bromberg (Jacolien); P.A.E. Sillevis Smitt (Peter); M.J. van den Bent (Martin)

    2012-01-01

    textabstractAlternative temozolomide regimens have been proposed to overcome O 6-methylguanine-DNA methyltransferase mediated resistance. We investigated the efficacy and tolerability of 1 week on/1 week off temozolomide (ddTMZ) regimen in a cohort of patients treated with ddTMZ between 2005 and 201

  9. Intracorneal blood removal six weeks after canaloplasty

    Directory of Open Access Journals (Sweden)

    Alberto Rossetti

    2013-01-01

    Full Text Available In a 71-year-old patient with bilateral open-angle glaucoma, intracorneal blood was found after a canaloplasty procedure in the right eye. Six weeks after surgery on ultrasound biomicroscopy examination, liquified blood and blood clots could be observed nasally in the deep corneal stroma close to the Descemet′s membrane. The intracorneal blood was washed out with balanced saline solution following deep corneal incision and lamellar dissection. Descemet′s membrane was reattached with air injection into the anterior chamber. Two months later, visual acuity improved to 20/50, intraocular pressure was 16 mm Hg without medication and confocal microscopy showed deep stromal folds and limited endothelial cell loss. Viscoelastic entering the cornea at Schwalbe′s line and reflux of blood from the collector channels to Schlemm′s canal can account for corneal hematoma. Even six weeks after canaloplasty, successful blood removal could be fulfilled without rupturing the Descemet′s membrane.

  10. Vehicle Technologies’ Fact of the Week 2013

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Stacy Cagle [ORNL; Diegel, Susan W. [ORNL; Moore, Sheila A. [ORNL; Boundy, Robert Gary [Roltek, Inc.

    2014-04-01

    Each week the U.S. Department of Energy’s Vehicle Technology Office (VTO) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/ . These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current week’s Fact is available on the VTO homepage, but older Facts are archived and still available at: http://www1.eere.energy.gov/vehiclesandfuels/facts/. This report is a compilation of the Facts that were posted during calendar year 2013. The Facts were written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.

  11. Oral 4-week and 13-week toxicity studies of polyvinyl acetate vinyl laurate copolymer in rats.

    Science.gov (United States)

    Messinger, Horst; Bär, Albert

    2014-10-01

    Polyvinyl acetate vinyl laurate copolymer (PVAcVL) is a useful component of gum base for chewing gum production. The safety of PVAcVL was examined in a 4-week and a 13-week oral toxicity study in rats. Finely powdered PVAcVL was administered with the diet at levels of 1.25%, 2.0% and 5% in the 4-week study and 1.25%, 2.5% and 5% in the 13-week study. There were no treatment related effects on mortality, bodyweight gains feed efficiency, ophthalmoscopic findings, hematological and clinical chemical parameters, neurobehavioral observations as well as gross and histopathological changes of standard organs and tissues. The highest dose tested in the 13-week study (3783 and 4396mg/kgbw/d for males and females, respectively) proved to be a NOAEL.

  12. Weekly petroleum status report. Data for week ended, October 21, 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-11-01

    The Weekly Petroleum Status Report (WPSR) provides timely information on the petroleum supply situation in the context of historical information, selected prices, and forecasts. The WPSR is intended to provide up-to-date information to the industry, the press, planners, policymakers, consumers, analysts, and State and local governments. It is published each Thursday by the Energy Information Administration (EIA) and excerpts of the data are available electronically after 9:00 a.m. Wednesday. The data contained in this report are based on company submissions for the week ending 7:00 a.m. the preceding Friday. For some weeks which include holidays, publication of the WPSR is delayed by 1 day. The WPSR is not published during 1 of the last 2 weeks of the year depending upon which day of the week Christmas occurs.

  13. A busy week for Arts@CERN

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    Last week, Semiconductor – the winners of the Collide@CERN Ars Electronica award for 2015 – and artists Francesco Mariotti and José­-Carlos Mariátegui visited CERN and met the scientists.   Ruth Jarman (left) and Joe Gerhardt (right) of Semiconductor with Peter Jenni, one of the scientists they met during their visit to ATLAS.   Just a few weeks ago, Ruth Jarman and Joe Gerhardt, two English artists collaborating under the name Semiconductor, were awarded the Collide@CERN Ars Electronica prize for 2015. Last week, they came on their first visit to CERN to meet the scientists and select their scientific partner in preparation for their residency. They will soon begin a two-month residency at CERN before going to Linz (Austria), where they will spend a month at the Ars Electronica Futurelab. During their residency, the artists aim to create a digital artwork elaborating on the n...

  14. Electronic topological transition in LaSn3 under pressure

    DEFF Research Database (Denmark)

    Ram, Swetarekha; Kanchana, V.; Vaitheeswaran, G.

    2012-01-01

    The electronic structure, Fermi surface, and elastic properties of the isostructural and isoelectronic LaSn3 and YSn3 intermetallic compounds are studied under pressure within the framework of density functional theory including spin-orbit coupling. The LaSn3 Fermi surface consists of two sheets...

  15. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  16. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  17. Spectropolarimetry of the Type IIb SN 2008aq

    CERN Document Server

    Stevance, H F; Baade, D; Hoflich, P; Patat, F; Spyromilio, J; Wheeler, J C; Clocchiatti, A; Wang, L; Yang, Y; Zelaya, P

    2016-01-01

    We present optical spectroscopy and spectropolarimetry of the Type IIb SN 2008aq 16 days and 27 days post-explosion. The spectrum of SN 2008aq remained dominated by Halpha P Cygni profile at both epochs, but showed a significant increase in the strength of the helium features, which is characteristic of the transition undergone by supernovae between Type IIb and Type Ib. Comparison of the spectra of SN 2008aq to other Type IIb SNe (SN 1993J, SN 2011dh, and SN 2008ax) at similar epochs revealed that the helium lines in SN 2008aq are much weaker, suggesting that its progenitor was stripped to a lesser degree. SN 2008aq also showed significant levels of continuum polarisation at p_cont = 0.70 (+/- 0.22) % in the first epoch, increasing to p_cont = 1.21 (+/- 0.33) % by the second epoch. Moreover, the presence of loops in the q-u planes of Halpha and He I in the second epoch suggests a departure from axial symmetry.

  18. Wafer bonding using Cu-Sn intermetallic bonding layers

    NARCIS (Netherlands)

    Flötgen, C.; Pawlak, M.; Pabo, E.; Wiel, H.J. van de; Hayes, G.R.; Dragoi, V.

    2014-01-01

    Wafer-level Cu-Sn intermetallic bonding is an interesting process for advanced applications in the area of MEMS and 3D interconnects. The existence of two intermetallic phases for Cu-Sn system makes the wafer bonding process challenging. The impact of process parameters on final bonding layer

  19. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  20. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  1. Do π-conjugative effects facilitate SN2 reactions?

    Science.gov (United States)

    Wu, Chia-Hua; Galabov, Boris; Wu, Judy I-Chia; Ilieva, Sonia; Schleyer, Paul von R; Allen, Wesley D

    2014-02-26

    Rigorous quantum chemical investigations of the SN2 identity exchange reactions of methyl, ethyl, propyl, allyl, benzyl, propargyl, and acetonitrile halides (X = F(-), Cl(-)) refute the traditional view that the acceleration of SN2 reactions for substrates with a multiple bond at Cβ (carbon adjacent to the reacting Cα center) is primarily due to π-conjugation in the SN2 transition state (TS). Instead, substrate-nucleophile electrostatic interactions dictate SN2 reaction rate trends. Regardless of the presence or absence of a Cβ multiple bond in the SN2 reactant in a series of analogues, attractive Cβ(δ(+))···X(δ(-)) interactions in the SN2 TS lower net activation barriers (E(b)) and enhance reaction rates, whereas repulsive Cβ(δ(-))···X(δ(-)) interactions increase E(b) barriers and retard SN2 rates. Block-localized wave function (BLW) computations confirm that π-conjugation lowers the net activation barriers of SN2 allyl (1t, coplanar), benzyl, propargyl, and acetonitrile halide identity exchange reactions, but does so to nearly the same extent. Therefore, such orbital interactions cannot account for the large range of E(b) values in these systems.

  2. Optical and Infrared Spectroscopy of the type IIn SN 1998S Days 3-127

    CERN Document Server

    Fassia, A; Chugai, N N; Geballe, T R; Lundqvist, P; Walton, N A; Pollacco, D L; Veilleux, S; Wright, G; Pettini, M; Kerr, T H; Puchnarewicz, E M; Puxley, P J; Irwin, M; Packham, C; Smartt, S J; Harmer, D

    2000-01-01

    We present contemporary infrared and optical spectroscopic observations of the type IIn SN 1998S for the period between 3 and 127 days after discovery. In the first week the spectra are characterised by prominent broad emission lines with narrow peaks superimposed on a very blue continuum(T~24000K). In the following two weeks broad, blueshifted absorption components appeared in the spectra and the temperature dropped. By day 44, broad emission components in H and He reappeared in the spectra. These persisted to 100-130d, becoming increasingly asymmetric. We agree with Leonard et al. (2000) that the broad emission lines indicate interaction between the ejecta and circumstellar material (CSM) and deduce that progenitor of SN 1998S appears to have gone through at least two phases of mass loss, giving rise to two CSM zones. Examination of the spectra indicates that the inner zone extended to 2x10^{-5}M_{\\odot}/yr corresponding to a mass loss of at least 0.003M_{\\odot} and suggesting a massive progenitor. We also ...

  3. Detection of the Sn(III) intermediate and the mechanism of the Sn(IV)/Sn(II) electroreduction reaction in bromide media by cyclic voltammetry and scanning electrochemical microscopy.

    Science.gov (United States)

    Chang, Jinho; Bard, Allen J

    2014-01-08

    Fast-scan cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM) were used to investigate the reduction of Sn(IV) as the hexabromo complex ion in a 2 M HBr-4 M NaBr medium. CV at scan rates to 100 V/s and SECM indicated the reaction pathway involves ligand-coupled electron transfer via an ECEC-DISP process: (1) one-electron reduction of Sn(IV)Br6(2-) to Sn(III)Br6(3-); (2) bromide dissociation of the reduced Sn(III)Br6(3-) to Sn(III)Br5(2-); (3) disproportionation of the reduced 2Sn(III)Br5(2-) to Sn(IV)Br5(-) and Sn(II)Br5(3-); (4) one-electron reduction of Sn(III)Br5(2-) to Sn(II)Br5(3-); (5) bromide dissociation from Sn(II)Br5 to Sn(II)Br4(2-). The intermediate Sn(III) species was confirmed by SECM(3-), where the Sn(III) generated at the Au tip was collected on a Au substrate in the tip generation/substrate collection mode when the distance between the tip and substrate was a few hundred nanometers.

  4. Synthesis and lithium storage properties of Zn, Co and Mg doped SnO2 Nano materials

    CSIR Research Space (South Africa)

    Palaniyandy, Nithyadharseni

    2017-09-01

    Full Text Available In this paper, we show that magnesium and cobalt doped SnO2 (Mg-SnO2 and Co-SnO2) nanostructures have profound influence on the discharge capacity and coulombic efficiency of lithium ion batteries (LIBs) employing pure SnO2 and zinc doped SnO2 (Zn-Sn...

  5. SiSn diodes: Theoretical analysis and experimental verification

    KAUST Repository

    Hussain, Aftab M.

    2015-08-24

    We report a theoretical analysis and experimental verification of change in band gap of silicon lattice due to the incorporation of tin (Sn). We formed SiSn ultra-thin film on the top surface of a 4 in. silicon wafer using thermal diffusion of Sn. We report a reduction of 0.1 V in the average built-in potential, and a reduction of 0.2 V in the average reverse bias breakdown voltage, as measured across the substrate. These reductions indicate that the band gap of the silicon lattice has been reduced due to the incorporation of Sn, as expected from the theoretical analysis. We report the experimentally calculated band gap of SiSn to be 1.11 ± 0.09 eV. This low-cost, CMOS compatible, and scalable process offers a unique opportunity to tune the band gap of silicon for specific applications.

  6. Process of electroless plating Cu-Sn-Zn ternary alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  7. Polymer-SnO2 composite membranes

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Skou, Eivind Morten

    When designing sulfonic acid based ionomers, high ion exchange capacity (IEC) comes at the expense of the mechanical properties. With too high IEC, the membrane will excessively swell or even dissolve in water. Therefore a suitable compromise must be found between high charge carrier concentration...... and adequate mechanical properties. It has been demonstrated that this compromise can be found at higher IEC when the mechanical properties are improved by increasing crystallinity, increasing molecular weight, crosslinking or reinforcement of the membrane by dispersion of interacting particles therein....... This work utilizes the latter approach and makes use of particles of tin dioxide (SnO2). Polymer-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into membranes by ion-exchange in solutions of SnCl2 ∙ 2 H2O in methanol, followed by oxidation to SnO2...

  8. The structure of 100Sn and neighbouring nuclei

    Science.gov (United States)

    Faestermann, T.; Górska, M.; Grawe, H.

    2013-03-01

    The nuclear structure in the 100Sn region is reviewed. State-of-the-art experimental techniques involving stable and radioactive beam facilities have enabled access to exotic nuclei in its next neighbourhood. The analysis of experimental data has established the shell structure and its evolution towards N=Z=50, seniority conservation and proton-neutron interaction in the g9/2 orbit, the super-allowed Gamow-Teller decay of 100Sn, masses and half lives along the rp-path, and super-allowed α decay beyond 100Sn. The status of theoretical approaches in shell model and mean-field investigations is described and their predictive power assessed. Structure features of 100Sn and its doubly-magic neighbours 56Ni at N=Z, 132Sn and 78Ni at N≫Z are compared. An outlook is given on future developments of experimental and theoretical methods.

  9. U7 snRNAs: A Computational Survey

    Institute of Scientific and Technical Information of China (English)

    Mania; Marz; Axel; Mosig; B(a)rbel; M.R.; Stadler; Peter; F.; Stadler

    2007-01-01

    U7 small nuclear RNA (snRNA) sequences have been described only for a handful of animal species in the past. Here we describe a computational search for func- tional U7 snRNA genes throughout vertebrates including the upstream sequence elements characteristic for snRNAs transcribed by polymerase Ⅱ. Based on the results of this search, we discuss the high variability of U7 snRNAs in both se- quence and structure, and report on an attempt to find U7 snRNA sequences in basal deuterostomes and non-drosophilids insect genomes based on a combination of sequence, structure, and promoter features. Due to the extremely short se- quence and the high variability in both sequence and structure, no unambiguous candidates were found. These results cast doubt on putative U7 homologs in even more distant organisms that are reported in the most recent release of the Rfam database.

  10. Intermetallic compound formation in Sn-Co-Cu, Sn-Ag-Cu and eutectic Sn-Cu solder joints on electroless Ni(P) immersion Au surface finish after reflow soldering

    Energy Technology Data Exchange (ETDEWEB)

    Sun Peng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China) and Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)]. E-mail: peng.sun@mc2.chalmers.se; Andersson, Cristina [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Wei Xicheng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Cheng Zhaonian [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Shangguan Dongkai [Flextronics International, San Jose, CA (United States); Liu Johan [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)

    2006-11-25

    The interfacial reactions between Sn-0.4Co-0.7Cu eutectic alloy and immersion Au/electroless Ni(P)/Cu substrate were investigated after reflow soldering at 260 deg. C for 2 min. Common Sn-4.0Ag-0.5Cu and eutectic Sn-0.7Cu solders were used as reference. Two types of intermetallic compounds (IMC) were found in the solder matrix of the Sn-0.4Co-0.7Cu alloy, namely coarser CoSn{sub 2} and finer Cu{sub 6}Sn{sub 5} particles, while only one ternary (Cu, Ni){sub 6}Sn{sub 5} interfacial compound was detected between the solder alloy and the electroless nickel and immersion gold (ENIG) coated substrate. The same trend was also observed for the Sn-Ag-Cu and Sn-Cu solder joints. Compared with the CoSn{sub 2} particles found in the Sn-Co-Cu solder and the Ag{sub 3}Sn particles found in the Sn-Ag-Cu solder, the Cu{sub 6}Sn{sub 5} particles found in both solder systems exhibited finer structure and more uniform distribution. It was noted that the thickness of the interfacial IMCs for the Sn-Co-Cu, Sn-Ag-Cu and Sn-Cu alloys was 3.5 {mu}m, 4.3 {mu}m and 4.1 {mu}m, respectively, as a result of longer reflow time above the alloy's melting temperature since the Sn-Ag-Cu solder alloy has the lowest melting point.

  11. Ternary Phases (Heusler) in the System Ti-Co-Sn

    Science.gov (United States)

    Kosinskiy, Andrey; Karlsen, Ole Bjørn; Sørby, Magnus H.; Prytz, Øystein

    2016-09-01

    Some of the Heusler-phases (XY 2 Z and XYZ) are known to have large homogeneity ranges which can be useful for tuning material properties. In this work, we have revised the isothermal section of the Ti-Co-Sn system at 973 K (700 °C). A total of 29 ternary compositions, mostly in the regions TiCo2-x Sn for 0 ≤ x ≤ 1 and Ti1+y Co2Sn1-y for 0 ≤ y ≤ 1, were prepared by arc-melting, then ball-milled and annealed. The resulting annealed powder samples were studied by applying the Rietveld method to X-ray and neutron powder diffraction data. Half-Heusler TiCoSn was not observed. The Heusler phase observed in TiCo2-x Sn has compositions ranging from TiCo1.52Sn to TiCo2Sn and has the half-Heusler structure where the excess of Co is located on the semi-filled tetrahedral site 4d (¾, ¾, ¾) in the space group F-43m. At 1273 K (1000 °C), this solid solubility is expanded from TiCo2Sn to TiCo with full solid solubility where Ti is gradually replacing Sn (Ti1+y Co2Sn1-y for 0 ≤ y ≤ 1), while at 973 K (700 °C) there is a small solubility gap for 0.0 ≤ y ≤ 0.2.

  12. Sn-doped hematite nanostructures for photoelectrochemical water splitting.

    Science.gov (United States)

    Ling, Yichuan; Wang, Gongming; Wheeler, Damon A; Zhang, Jin Z; Li, Yat

    2011-05-11

    We report on the synthesis and characterization of Sn-doped hematite nanowires and nanocorals as well as their implementation as photoanodes for photoelectrochemical water splitting. The hematite nanowires were prepared on a fluorine-doped tin oxide (FTO) substrate by a hydrothermal method, followed by high temperature sintering in air to incorporate Sn, diffused from the FTO substrate, as a dopant. Sn-doped hematite nanocorals were prepared by the same method, by adding tin(IV) chloride as the Sn precursor. X-ray photoelectron spectroscopy analysis confirms Sn(4+) substitution at Fe(3+) sites in hematite, and Sn-dopant levels increase with sintering temperature. Sn dopant serves as an electron donor and increases the carrier density of hematite nanostructures. The hematite nanowires sintered at 800 °C yielded a pronounced photocurrent density of 1.24 mA/cm(2) at 1.23 V vs RHE, which is the highest value observed for hematite nanowires. In comparison to nanowires, Sn-doped hematite nanocorals exhibit smaller feature sizes and increased surface areas. Significantly, they showed a remarkable photocurrent density of 1.86 mA/cm(2) at 1.23 V vs RHE, which is approximately 1.5 times higher than that of the nanowires. Ultrafast spectroscopy studies revealed that there is significant electron-hole recombination within the first few picoseconds, while Sn doping and the change of surface morphology have no major effect on the ultrafast dynamics of the charge carriers on the picosecond time scales. The enhanced photoactivity in Sn-doped hematite nanostructures should be due to the improved electrical conductivity and increased surface area.

  13. Structural and electronic properties of SnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Physics Department, Nigde University, 51240 Nigde (Turkey); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gumus, Cebrail, E-mail: cgumus@cu.edu.tr [Physics Department, Cukurova University, 01330 Adana (Turkey); Er, Ali O. [Department of Chemistry, University of California, Irvine, CA 92612 (United States); Farha, Ashraf H. [Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529 (United States); Physics Department, Ain Shams University, Cairo 11566 (Egypt); Akgul, Guvenc [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Ufuktepe, Yuksel [Physics Department, Cukurova University, 01330 Adana (Turkey); Liu, Zhi [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2013-12-05

    Highlights: •Structural and electronic properties of SnO{sub 2} films were determined. •Oxidation states of the SnO{sub 2} thin films were confirmed by XPS analysis. •Chemical component is non-stoichiometric and ratio of oxygen to tin was 1.85. -- Abstract: Highly transparent polycrystalline thin film of SnO{sub 2} (tin dioxide) was deposited using a simple and low cost spray pyrolysis method. The film was prepared from an aqueous solution of tin tetrachloride (stannic chloride) onto glass substrates at 400 °C. A range of diagnostic techniques including X-ray diffraction (XRD), UV–visible absorption, atomic force microscopy (AFM), scanning electron microscopy (SEM), and synchrotron-based X-ray photoelectron spectroscopy (XPS) were used to investigate structural, optical, and electronic properties of the resulting film. Deposited film was found to be polycrystalline. A mixture of SnO and SnO{sub 2} phases was observed. The average crystallite size of ∼21.3 nm for SnO{sub 2} was calculated by Rietveld method using XRD data. The oxidation states of the SnO{sub 2} thin film were confirmed by the shape analysis of corresponding XPS O 1s, Sn 3d, and Sn 4d peaks using the decomposition procedure. The analysis of the XPS core level peaks showed that the chemical component is non-stoichiometric and the ratio of oxygen to tin (O/Sn) is 1.85 which is slightly under stoichiometry.

  14. Endohedrally filled [Ni@Sn9](4-) and [Co@Sn9](5-) clusters in the neat solids Na12Ni(1-x)Sn17 and K(13-x)Co(1-x)Sn17: crystal structure and 119Sn solid-state NMR spectroscopy.

    Science.gov (United States)

    Hlukhyy, Viktor; Stegmaier, Saskia; van Wüllen, Leo; Fässler, Thomas F

    2014-09-15

    A systematic approach to the formation of endohedrally filled atom clusters by a high-temperature route instead of the more frequent multistep syntheses in solution is presented. Zintl phases Na12Ni(1-x)Sn17 and K(13-x)Co(1-x)Sn17, containing endohedrally filled intermetalloid clusters [Ni@Sn9](4-) or [Co@Sn9](5-) beside [Sn4](4-), are obtained from high-temperature reactions. The arrangement of [Ni@Sn9](4-) or [Co@Sn9](5-) and [Sn4](4-) clusters, which are present in the ratio 1:2, can be regarded as a hierarchical replacement variant of the hexagonal Laves phase MgZn2 on the Mg and Zn positions, respectively. The alkali-metal positions are considered for the first time in the hierarchical relationship, which leads to a comprehensive topological parallel and a better understanding of the composition of these compounds. The positions of the alkali-metal atoms in the title compounds are related to the known inclusion of hydrogen atoms in the voids of Laves phases. The inclusion of Co atoms in the {Sn9} cages correlates strongly with the number of K vacancies in K(13-x)Co(1-x)Sn17 and K(5-x)Co(1-x)Sn9, and consequently, all compounds correspond to diamagnetic valence compounds. Owing to their diamagnetism, K(13-x)Co(1-x)Sn17, and K(5-x)Co(1-x)Sn9, as well as the d-block metal free binary compounds K12Sn17 and K4Sn9, were characterized for the first time by (119)Sn solid-state NMR spectroscopy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. bus660 full course  all discussions and all week assignments but no week 8

    OpenAIRE

    Laynebaril

    2017-01-01

    bus660 full course  all discussions and all week assignments but no week 8   Click Link Below To Buy:   http://hwcampus.com/shop/bus660-full-course/   week 1 Present an example of a business situation that you believe would lend itself to the use of a quantitative business model. Clearly explain how the model could be used in this situation. grand canyon 2 Multiple models are often used in supporting business decision making. Why might this be the case and ...

  16. Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Modibedi, RM

    2011-04-01

    Full Text Available the coverage of the adsorbed ethoxy (CH3COads) species on the nanocatalyst surface, thus yielding an increase in current density. Pd-Sn/C displayed better electrocatalytic activity and stability towards poisoning than Pd-Ru-Sn/C and Pt-Ru/C (E-TEK Inc...

  17. Pulse number controlled laser annealing for GeSn on insulator structure with high substitutional Sn concentration

    Science.gov (United States)

    Moto, Kenta; Matsumura, Ryo; Sadoh, Taizoh; Ikenoue, Hiroshi; Miyao, Masanobu

    2016-06-01

    Crystalline GeSn-on-insulator structures with high Sn concentration (>8%), which exceeds thermal equilibrium solid-solubility (˜2%) of Sn in Ge, are essential to achieve high-speed thin film transistors and high-efficiency optical devices. We investigate non-thermal equilibrium growth of Ge1-xSnx (0 ≤ x ≤ 0.2) on quartz substrates by using pulsed laser annealing (PLA). The window of laser fluence enabling complete crystallization without film ablation is drastically expanded (˜5 times) by Sn doping above 5% into Ge. Substitutional Sn concentration in grown layers is found to be increased with decreasing irradiation pulse number. This phenomenon can be explained on the basis of significant thermal non-equilibrium growth achieved by higher cooling rate after PLA with a lower pulse number. As a result, GeSn crystals with substitutional Sn concentration of ˜12% are realized at pulse irradiation of single shot for the samples with the initial Sn concentration of 15%. Raman spectroscopy and electron microscopy measurements reveal the high quality of the grown layer. This technique will be useful to fabricate high-speed thin film transistors and high-efficiency optical devices on insulating substrates.

  18. Insight into the Effect of Sn on CO and Formic Acid Oxidation at PtSn Catalysts

    DEFF Research Database (Denmark)

    Stevanović, S.; Tripković, D.; Tripkovic, Vladimir

    2014-01-01

    The role of Sn on the catalytic activity for CO and formic acid oxidation is studied by comparing the activities of differently treated PtSn/C and Pt/C catalysts. The catalysts are prepared by a microwave-assisted polyol synthesis method. As revealed by scanning tunneling and transmission electron...... is present only in the subsurface layers. The subsurface Sn has a mild effect on the CO activity, and hence the onset potential is only marginally shifted to cathodic potentials by ∼50 mV compared to that on Pt/C. The formic acid oxidation is enhanced at any of the PtSn/C surfaces with Sn in the surface...... alloying degree and is mainly composed of Pt and Pt3Sn phases. The remaining Sn is present in the form of very small tin oxide particles. Different surfaces are obtained by double-layer, oxide, and CO annealing of the Pt/C and PtSn/C catalysts and by modifying the CO-annealed surfaces with irreversibly...

  19. Unexpected, spontaneous and selective formation of colloidal Pt 3Sn nanoparticles using organometallic Pt and Sn complexes

    KAUST Repository

    Boualleg, Malika

    2010-01-01

    The facile and selective synthesis of small crystalline Pt3Sn alloy nanoparticles was performed at room temperature under H2, using a colloidal approach without the use of extra-stabilizing ligands. The Pt 3Sn alloy was found to be obtained spontaneously as the unique phase regardless of the number of tin equivalents introduced. © 2010 The Royal Society of Chemistry.

  20. X-ray powder diffraction and EXAFS studies on SnAPO-5 and Cu : SnAPO-5

    DEFF Research Database (Denmark)

    Flavell, W. R.; Nicholson, D. G.; Nilsen, M. H.;

    2001-01-01

    SnAPO-5 was synthesised and calcined at 800 degreesC. Copper was introduced into the calcined material by the incipient wetness method. The as-synthesised, calcined and copper-incorporated SnAPO-5 have been studied using X-ray powder diffraction and EXAFS. Rietveld refinements show that the overa...

  1. Type Ibn Supernovae Show Photometric Homogeneity and Spectral Diversity at Maximum Light

    OpenAIRE

    Hosseinzadeh, Griffin; Arcavi, Iair; Valenti, Stefano; McCully, Curtis; Howell, D. Andrew; Johansson, Joel; Sollerman, Jesper; Pastorello, Andrea; Benetti, Stefano; Cao, Yi; Cenko, S Bradley; Clubb, Kelsey; Corsi, Alessandra; Duggan, Gina; Elias-Rosa, Nancy

    2016-01-01

    Type Ibn supernovae (SNe) are a small yet intriguing class of explosions whose spectra are characterized by low-velocity helium emission lines with little to no evidence for hydrogen. The prevailing theory has been that these are the core-collapse explosions of very massive stars embedded in helium-rich circumstellar material (CSM). We report optical observations of six new SNe Ibn: PTF11rfh, PTF12ldy, iPTF14aki, iPTF15ul, SN 2015G, and iPTF15akq. This brings the sample size of such objects i...

  2. Future Circular Collider study week 2017

    CERN Document Server

    2017-01-01

    The annual meetings of the worldwide Future Circular Collider study (FCC) are major international events that review the progress in every domain which is relevant to develop feasible concepts for a next generation frontier particle accelerate based high-energy physics research infrastructure. This 3rd meeting is jointly organised by CERN and DESY. It is also the annual meeting of the EuroCirCol EC Horizon 2020 Research and Innovation Action project. Previous events took place in Washington and Rome. In 2017 the FCC Week will take place in Berlin, Germany between May 29 and June 2.

  3. Teaching Crossroads: 10th IPB Erasmus Week

    OpenAIRE

    2015-01-01

    This is the fourth number of a project which started in 2011 when the idea of publishing the lectures delivered by guest teachers in our Erasmus Week came up. This annual event is organised by the Polytechnic Institute of Bragança (IPB) and takes place normally in the beginning of May. The title was not difficult to find as the main purpose with this publication was to include every research and teaching areas fitting a multidisciplinary journal with a very specific European ap...

  4. Closing a temporary ileostomy within two weeks

    DEFF Research Database (Denmark)

    Hindenburg, Tommy; Rosenberg, J.

    2010-01-01

    Temporary ileostomy is frequently constructed to relieve a rectal anastomosis and avoid peritonitis if the anastomosis is leaking. Ostomy is a burden for both the patient and society and early closure is therefore desirable to counteract increased morbidity. Several prospective studies and a single...... randomized controlled trial have shown that closure in less than two weeks was associated with lower or equal morbidity compared with later closure. Thus, current data support early closure of temporary ileostomy performed to cover rectal anastomosis in routine clinical practice...

  5. Synthesis and characterization of highly conductive Sn-Ag bimetallic nanoparticles for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Yun Hwan; Jung, Inyu; Kim, Na Rae; Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [KAIST, Department of Materials Science and Engineering (Korea, Republic of)

    2012-03-15

    To synthesize low-cost, highly conductive metal nanoparticles for inkjet printing materials, we synthesized Sn-Ag bimetallic nanoparticles using a polyol process with poly(vinyl pyrrolidone). Because a surface oxidation layer forms on Sn nanoparticles, various compositions of Sn-xAg [x = 0, 20, 40, 60, 80, 100 (wt%)] nanoparticles were synthesized and characterized for the purpose of removing the {beta}-Sn phase. The results of XPS, TEM, and XRD analyses confirm that the formation of a bimetallic phase, such as Ag{sub 4}Sn or Ag{sub 3}Sn, hinders the {beta}-Sn phase and, consequently, leads to the removal of the surface oxidation layer. To measure the sheet resistance of various compositions of Sn-Ag nanoparticles, we made the ink that contains Sn-Ag by dispersing 10 wt% of Sn-Ag nanoparticles in methanol. The sheet resistance is decreased by the conductive Sn-Ag phases, such as the fcc, Ag{sub 4}Sn, and Ag{sub 3}Sn phases, but sharply increased by the low-conductive Sn nanoparticles and the surface oxidation layer on the Sn nanoparticles. The sheet resistance results confirm that 80Ag20Sn and 60Ag40Sn bimetallic nanoparticles are suitable candidates for inkjet printing materials.

  6. Effect of plasma etching on photoluminescence of SnO(x)/Sn nanoparticles deposited on DOPC lipid membrane.

    Science.gov (United States)

    An, Hyeun Hwan; Lee, Seung Jae; Baek, Seung Ha; Han, Won Bae; Kim, Young Ho; Yoon, Chong Seung; Suh, Sang Hee

    2012-02-15

    The photoluminescence characteristic of the SnO(x)/Sn nanoparticles deposited on a solid supported liquid-crystalline phospholipid (1,2-dioleoyl-sn-glycero-3-phosphocholine) membrane was probed after plasma etching the nanoparticle monolayer. It was shown that the plasma etching of the nanoparticle surface greatly altered the particle morphology and enhanced the PL effect, especially when the particle size was below 10 nm in spite of strong presence of surrounding carbon. The enhancement mainly stemmed from the growth of a new PL peak due to the additional defect states produced on the nanoparticle surface by the plasma etching. It was also shown that hydrating the SnO(x)/Sn nanoparticles similarly improved the PL response of the nanoparticles as the hydration produced an additional oxygen-rich oxide layer on the particle surface. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Research on structure of Cu2ZnSn(S, Se)4 thin films with high Sn-related phases

    Science.gov (United States)

    Li, Peng-yu; Xue, Yu-ming; Liu, Hao; Xia, Dan; Song, Dian-you; Feng, Shao-jun; Sun, Hai-tao; Yu, Bing-bing; Qiao, Zai-xiang

    2016-11-01

    Cu2ZnSn(S, Se)4 (CZTSSe) thin films were deposited on flexible substrates by three evaporation processes at high temperature. The chemical compositions, microstructures and crystal phases of the CZTSSe thin films were respectively characterized by inductively coupled plasma optical emission spectrometer (ICP-OES), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman scattering spectrum. The results show that the single-step evaporation method at high temperature yields CZTSSe thin films with nearly pure phase and high Sn-related phases. The elemental ratios of Cu/(Zn+Sn)=1.00 and Zn/Sn=1.03 are close to the characteristics of stoichiometric CZTSSe. There is the smooth and uniform crystalline at the surface and large grain size at the cross section for the films, and no other phases exist in the film by XRD and Raman shift measurement. The films are no more with the Sn-related phase deficiency.

  8. Sn powder as reducing agents and SnO2 precursors for the synthesis of SnO2-reduced graphene oxide hybrid nanoparticles.

    Science.gov (United States)

    Chen, Mingxi; Zhang, Congcong; Li, Lingzhi; Liu, Yu; Li, Xichuan; Xu, Xiaoyang; Xia, Fengling; Wang, Wei; Gao, Jianping

    2013-12-26

    A facile approach to prepare SnO2/rGO (reduced graphene oxide) hybrid nanoparticles by a direct redox reaction between graphene oxide (GO) and tin powder was developed. Since no acid was used, it is an environmentally friendly green method. The SnO2/rGO hybrid nanoparticles were characterized by ultraviolet-visible spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The microstructure of the SnO2/rGO was observed with scanning electron microscopy and transmission electron microscopy. The tin powder efficiently reduced GO to rGO, and the Sn was transformed to SnO2 nanoparticles (∼45 nm) that were evenly distributed on the rGO sheets. The SnO2/rGO hybrid nanoparticles were then coated on an interdigital electrode to fabricate a humidity sensor, which have an especially good linear impedance response from 11% to 85% relative humidity.

  9. THIRTY SEVEN WEEKS AND BEYOND MATERNAL AND FOETAL OUTCOME BY WEEK OF GESTATION

    OpenAIRE

    Geeta Jagannath; Ravikanth Onkarappa; Ruma

    2016-01-01

    BACKGROUND It was noted in 1951 that although pregnancies persisting beyond 300 days occurred less than 5% of the time, they accounted for 30% of perinatal deaths. In the most recent Technical Bulletin on post-term pregnancy, the American College of Obstetricians and Gynaecologists reiterated the threshold of 42 weeks of gestation as the definition of post-term pregnancy. Their continued use of 42 weeks is particularly surprising in the face of an abundance of research demonstr...

  10. Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

    KAUST Repository

    Zhu, Haibo

    2014-12-01

    A new one pot, surfactant-free, synthetic route based on the surface organometallic chemistry (SOMC) concept has been developed for the synthesis of Sn surface-enriched Pt-Sn nanoparticles. Bu3SnH selectively reacts with [Pt]-H formed in situ at the surface of Pt nanoparticles, Pt NPs, obtained by reduction of K2PtCl4 by LiB(C2H5)3H. Chemical analysis, 1H MAS and 13C CP/MAS solid-state NMR as well as two-dimensional double-quantum (DQ) and triple-quantum (TQ) experiments show that organo-tin moieties Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as-synthesized Pt-Sn NPs, enabling the bimetallic NPs to be well dispersed in THF. Additionally, the Pt-Sn nanoparticles can be supported on MgAl2O4 during the synthesis of the nanoparticles. Some of the Pt-Sn/MgAl2O4 catalyst thus prepared exhibits high activity in PROX of CO and an extremely high selectivity and stability in propane dehydrogenation to propylene. The enhanced activity in propane dehydrogenation is associated with the high concentration of inactive Sn at the surface of Pt nanoparticles which ”isolates” the active Pt atoms. This conclusion is confirmed by XRD, NMR, TEM, and XPS analysis.

  11. Preparation of porous SnO{sub 2} helical nanotubes and SnO{sub 2} sheets

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Ling; Xu, Yun [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States); Chen, Zheng [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States); Yuan, Bin; Wu, Xiaofei; Hill, Joshua; Lin, Qianglu; Deng, Shuguang; Andersen, Paul [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States); Lu, Yunfeng [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States); Luo, Hongmei, E-mail: hluo@nmsu.edu [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States)

    2013-06-15

    We report a surfactant-free chemical solution route for synthesizing one-dimensional porous SnO{sub 2} helical nanotubes templated by helical carbon nanotubes and two-dimensional SnO{sub 2} sheets templated by graphite sheets. Transmission electron microscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic discharge–charge analysis are used to characterize the SnO{sub 2} samples. The unique nanostructure and morphology make them promising anode materials for lithium-ion batteries. Both the SnO{sub 2} with the tubular structure and the sheet structure shows small initial irreversible capacity loss of 3.2% and 2.2%, respectively. The SnO{sub 2} helical nanotubes show a specific discharge capacity of above 800 mAh g{sup −1} after 10 charge and discharge cycles, exceeding the theoretical capacity of 781 mAh g{sup −1} for SnO{sub 2}. The nanotubes remain a specific discharge capacity of 439 mAh g{sup −1} after 30 cycles, which is better than that of SnO{sub 2} sheets (323 mAh g{sup −1}). - Highlights: • Synthesized porous SnO{sub 2} helical nanotubes with diameters of 100–120 nm. • Synthesized porous SnO{sub 2} sheets template by graphite sheets. • The tubular and sheet SnO{sub 2} have small initial irreversible capacity loss of 3.2 and 2.2%. • The tubular structure shows better discharge capacity than the sheet structure.

  12. Influence of hydrogen surface passivation on Sn segregation, aggregation, and distribution in GeSn/Ge(001) materials

    Science.gov (United States)

    Johll, Harman; Samuel, Milla; Koo, Ruey Yi; Kang, Hway Chuan; Yeo, Yee-Chia; Tok, Eng Soon

    2015-05-01

    Plane-wave density functional theory is used to investigate the impact of hydrogen passivation of the p(2×2) reconstructed Ge1-xSnx surface on Sn segregation, aggregation, and distribution. On a clean surface, Sn preferentially segregates to the surface layer, with surface coverages of 25%, 50%, and 100% for total Sn concentrations of 2.5%, 5.0%, and 10.0%, respectively. In contrast, a hydrogen passivated surface increases interlayer migration of Sn to subsurface layers, in particular, to the third layer from the surface, and results in surface coverages of 0%, 0%, and 50% corresponding to Sn concentrations of 2.5%, 5.0%, and 10.0%, respectively. Hydrogen transfer from a Ge-capped surface to the one enriched with increasing Sn surface coverage is also an unfavorable process. The presence of hydrogen therefore reduces the surface energy by passivating the reactive dangling bonds and enhancing Sn interlayer migration to the subsurface layers. For both clean and hydrogenated surfaces, aggregation of Sn at the surface layer is also not favored. We explain these results by considering bond enthalpies and the enthalpies of hydrogenation for various surface reactions. Our results thus point to reduced Sn segregation to the surface in a Ge1-xSnx epitaxial thin film if CVD growth, using hydride precursors in the hydrogen limited growth regime, is used. This would lead to a more abrupt interface and is consistent with recent experimental observation. Hydrogenation is therefore a promising method for controlling and manipulating elemental population of Sn in a Ge1-xSnx epitaxial thin film.

  13. The impact of bowel cancer awareness week.

    Science.gov (United States)

    Pullyblank, A M; Dixon, N; Dixon, A R

    2002-11-01

    To assess knowledge of Bowel Cancer Awareness Week (BCAW) amongst patients attending their general practice surgery and to identify whether BCAW could increase knowledge of colorectal cancer symptoms. Questionnaire study with ethics committee approval. Patients attending non-emergency clinics in a single general practice during the week following BCAW were given a questionnaire. Respondents were asked for knowledge of colorectal cancer symptoms, sources of this information and awareness of BCAW compared to similar knowledge of breast cancer. Seventy-seven patients responded (96% response rate, median age 42, 40% male). Eighty-five percent could name a breast cancer symptom compared to only 44% who could name a colorectal cancer symptom (McNemar's chi2, P breast than colorectal cancer. Only 21% had heard of BCAW and none could name any symbol for bowel cancer awareness whereas 69% were aware of Breast Cancer Awareness Month and 28% could name its symbol (McNemar's chi2, P aware of BCAW were 4.6 times more likely to have knowledge of colorectal cancer symptoms (95% CI 1.25-17.1). Despite their similar incidence, knowledge of colorectal cancer is much less than breast cancer. In part this may be due to the greater publicity given to breast cancer. BCAW can increase knowledge of colorectal cancer symptoms but currently, too few people are aware of it.

  14. Development and properties of surfactant-free water-dispersible Cu2ZnSnS4 nanocrystals: a material for low-cost photovoltaics.

    Science.gov (United States)

    Kush, Priya; Ujjain, Sanjeev Kumar; Mehra, Navin Chand; Jha, Pika; Sharma, Raj Kishore; Deka, Sasanka

    2013-08-26

    A simple, yet novel hydrothermal method has been developed to synthesize surfactant-free Cu2ZnSnS4 nanocrystal ink in water. The environmentally friendly, 2-4 nm ultrafine particles are stable in water for several weeks. Detailed X-ray diffraction (XRD) and high-resolution transmission electron microscopy revealed the formation of single-crystalline-kesterite-phase Cu2ZnSnS4. Elemental mapping by scanning electron microscopy/energy dispersive spectrometry corroborated the presence of all four elements in a stoichiometric ratio with minor sulfur deficiency. Finally, Raman spectroscopy ruled out the possible presence of impurities of ZnS, Cu2SnS3, SnS, SnS2, Cu(2-x)S, or Sn2S3, which often interfere with the XRD and optical spectra of Cu2ZnSnS4. X-ray photoelectron spectroscopic studies of the as-synthesized samples confirmed that the oxidation states of the four elements match those of the bulk sample. Optical absorption analyses of thin film and solution samples showed high absorption efficiency (>10(4) cm(-1)) across the visible and near-infrared spectral regions and a band gap E(g) of 1.75 eV for the as-synthesized sample. A non-ohmic asymmetric rectifying response was observed in the I-V measurement at room temperature. The nonlinearity was more pronounced for this p-type semiconductor when the resistance was measured against temperature in the range 180-400 K, which was detected in the hot-point probe measurement.

  15. Development and evaluation of the LiSN & learn auditory training software for deficit-specific remediation of binaural processing deficits in children: preliminary findings.

    Science.gov (United States)

    Cameron, Sharon; Dillon, Harvey

    2011-01-01

    The LiSN & Learn auditory training software was developed specifically to improve binaural processing skills in children with suspected central auditory processing disorder who were diagnosed as having a spatial processing disorder (SPD). SPD is defined here as a condition whereby individuals are deficient in their ability to use binaural cues to selectively attend to sounds arriving from one direction while simultaneously suppressing sounds arriving from another. As a result, children with SPD have difficulty understanding speech in noisy environments, such as in the classroom. To develop and evaluate the LiSN & Learn auditory training software for children diagnosed with the Listening in Spatialized Noise-Sentences Test (LiSN-S) as having an SPD. The LiSN-S is an adaptive speech-in-noise test designed to differentially diagnose spatial and pitch-processing deficits in children with suspected central auditory processing disorder. Participants were nine children (aged between 6 yr, 9 mo, and 11 yr, 4 mo) who performed outside normal limits on the LiSN-S. In a pre-post study of treatment outcomes, participants trained on the LiSN & Learn for 15 min per day for 12 weeks. Participants acted as their own control. Participants were assessed on the LiSN-S, as well as tests of attention and memory and a self-report questionnaire of listening ability. Performance on all tasks was reassessed after 3 mo where no further training occurred. The LiSN & Learn produces a three-dimensional auditory environment under headphones on the user's home computer. The child's task was to identify a word from a target sentence presented in background noise. A weighted up-down adaptive procedure was used to adjust the signal level of the target based on the participant's response. On average, speech reception thresholds on the LiSN & Learn improved by 10 dB over the course of training. As hypothesized, there were significant improvements in posttraining performance on the LiSN-S conditions

  16. Host Galaxy Spectra and Consequences for SN Typing from the SDSS SN Survey

    Energy Technology Data Exchange (ETDEWEB)

    Olmstead, Matthew D.; Brown, Peter J.; Sako, Masao; Bassett, Bruce; Bizyaev, Dmitry; Brinkmann, J.; Brownstein, Joel R.; Brewington, Howard; Campbell, Heather; D’Andrea, Chris B.; Dawson, Kyle S.; Ebelke, Garrett L.; Frieman, Joshua A.; Galbany, Lluís; Garnavich, Peter; Gupta, Ravi R.; Hlozek, Renee; Jha, Saurabh W.; Kunz, Martin; Lampeitl, Hubert; Malanushenko, Elena; Malanushenko, Viktor; Marriner, John; Miquel, Ramon; Montero-Dorta, Antonio D.; Nichol, Robert C.; Oravetz, Daniel J.; Pan, Kaike; Schneider, Donald P.; Simmons, Audrey E.; Smith, Mathew; Snedden, Stephanie A.

    2014-03-06

    We present the spectroscopy from 5254 galaxies that hosted supernovae (SNe) or other transient events in the Sloan Digital Sky Survey II (SDSS-II). Obtained during SDSS-I, SDSS-II, and the Baryon Oscillation Spectroscopic Survey (BOSS), this sample represents the largest systematic, unbiased, magnitude limited spectroscopic survey of supernova (SN) host galaxies. Using the host galaxy redshifts, we test the impact of photometric SN classification based on SDSS imaging data with and without using spectroscopic redshifts of the host galaxies. Following our suggested scheme, there are a total of 1166 photometrically classified SNe Ia when using a flat redshift prior and 1126 SNe Ia when the host spectroscopic redshift is assumed. For 1024 (87.8%) candidates classified as likely SNe Ia without redshift information, we find that the classification is unchanged when adding the host galaxy redshift. Using photometry from SDSS imaging data and the host galaxy spectra, we also report host galaxy properties for use in future nalysis of SN astrophysics. Finally, we investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. When using the SALT2 light curve fitter, we find a 21% increase in the number of fits that converge when using the spectroscopic redshift. Without host galaxy redshifts, we find that SALT2 light curve fits are systematically biased towards lower photometric redshift estimates and redder colors in the limit of low signal-to-noise data. The general improvements in performance of the light curve fitter and the increased diversity of the host galaxy sample highlights the importance of host galaxy spectroscopy for current photometric SN surveys such as the Dark Energy Survey and future surveys such as the Large Synoptic Survey Telescope.

  17. SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

    Science.gov (United States)

    Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2008-11-25

    Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

  18. $Nb_{3}Sn macrostructure, microstructure, and property comparisons for bronze and internal Sn process strands

    CERN Document Server

    Lee, P J; Larbalestier, D C

    2000-01-01

    The variation in irreversibility field, B*(T), with temperature has been measured for Nb/sub 3/Sn superconducting strands manufactured for ITER using vibrating sample and SQUID magnetometers. The high performance strands were developed for both high transport critical current density, J/sub c/, and low hysteresis loss. Despite a wide variety of designs and components, the strands could be split into two distinctive groups, based on the extrapolated irreversibility fields, which lie about 10% lower than the upper critical field. "Bronze-process" strands exhibited consistently higher B*(T) (28 T to 31 T) compared with "internal Sn" process (24 T to 26 T) conductors. The intrinsic critical current density of the superconductor, J/sub c (sc)/, and the specific pinning force of the grain boundaries, Q/sub gb/, were evaluated using the measured J/sub c/, and image analysis of the macro- and micro-structures. A bronze-processed Nb(-Ta)/sub 3 /Sn was found to have a higher J/sub c(sc)/ but lower Q/sub gb/ than Nb/sub...

  19. SnS Thin Film Solar Cells: Perspectives and Limitations

    Directory of Open Access Journals (Sweden)

    Simone Di Mare

    2017-02-01

    Full Text Available Thin film solar cells have reached commercial maturity and extraordinarily high efficiency that make them competitive even with the cheaper Chinese crystalline silicon modules. However, some issues (connected with presence of toxic and/or rare elements are still limiting their market diffusion. For this reason new thin film materials, such as Cu2ZnSnS4 or SnS, have been introduced so that expensive In and Te, and toxic elements Se and Cd, are substituted, respectively, in CuInGaSe2 and CdTe. To overcome the abundance limitation of Te and In, in recent times new thin film materials, such as Cu2ZnSnS4 or SnS, have been investigated. In this paper we analyze the limitations of SnS deposition in terms of reproducibility and reliability. SnS deposited by thermal evaporation is analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The raw material is also analyzed and a different composition is observed according to the different number of evaporation (runs. The sulfur loss represents one of the major challenges of SnS solar cell technology.

  20. Parametrized dielectric functions of amorphous GeSn alloys

    Energy Technology Data Exchange (ETDEWEB)

    D' Costa, Vijay Richard, E-mail: elevrd@nus.edu.sg; Wang, Wei; Yeo, Yee-Chia, E-mail: eleyeoyc@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Schmidt, Daniel [Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603 (Singapore)

    2015-09-28

    We obtained the complex dielectric function of amorphous Ge{sub 1−x}Sn{sub x} (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge{sub 0.75}Sn{sub 0.25} and Ge{sub 0.50}Sn{sub 0.50} alloys from literature. The compositional dependence of band gap energy E{sub g} and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  1. Facile route to SnS nanocrystals and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Koktysh, Dmitry S., E-mail: dmitry.koktysh@vanderbilt.edu [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); McBride, James R. [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Geil, Robert D. [Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Schmidt, Benjamin W. [Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Rogers, Bridget R. [Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Rosenthal, Sandra J. [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Department of Physics and Astronomy, Vanderbilt University, 1807 Station B, Nashville, TN 37235 (United States); Department of Pharmacology, Vanderbilt University, 1211 Medical Center Drive, Nashville, TN 37232 (United States)

    2010-06-15

    SnS nanocrystals (NCs) were synthesized in oleylamine using the hot-injection technique from tin(II) chloride and diethylammonium diethyldithiocarbamate in the presence of dodecanethiol. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis revealed the formation of single crystalline SnS NCs with sizes finely controlled by synthetic conditions. Rutherford backscattering spectrometry (RBS) and X-ray photoelectron spectroscopy (XPS) investigation confirmed the formation of SnS in a nearly stoichiometric ratio with additional evidence of the SnS NCs surface oxidation when NCs were stored in the air. Optical absorption measurements showed a shift in band gap energy of SnS NCs towards larger values with decreasing particle sizes. SnS NCs were successfully transferred into water using cetyltrimethylammonium bromide and Vitamin E as surfactants. These VIS/NIR absorbing SnS NCs should have widespread applications in the construction of efficient photoelectronic devices and probes in bioimaging due to their unique optoelectronic properties and low toxicity.

  2. Mechanothermal synthesis of SrSnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Berbenni, Vittorio; Milanese, Chiara; Bruni, Giovanna; Girella, Alessandro; Marini, Amedeo [Pavia Univ. (Italy). Sezione di Chimica Fisica

    2014-03-15

    The synthesis of strontium metastannate (SrSnO{sub 3}) has been performed by coupling mechanical activation with thermal activation of SnC{sub 2}O{sub 4}-SrCO{sub 3} mixtures. The solid-state reaction has been studied by TG-DSC analysis and powder X-ray diffraction. By annealing experiments performed on physical mixtures (no mechanical activation) it has been assessed that the formation of SrSnO{sub 3} occurs through the intermediate Sr{sub 2}SnO{sub 4} and is complete only after annealing at 1400 C. By performing the annealing experiments on activated mixtures it has been established that the formation of SrSnO{sub 3} takes place directly at temperatures between 800 and 1000 C. The SrSnO{sub 3} samples obtained at 800 and 900 C show, by TG analysis, mass loss processes that suggest that SrSnO{sub 3} obtained at these temperatures absorbs H{sub 2}O and CO{sub 2} from the air so that its use as gas sensor can be envisaged. This is no longer true for the sample obtained at 1000 C or above.

  3. 136Sn and three-body forces

    Indian Academy of Sciences (India)

    M Saha Sarkar; S Sarkar

    2015-09-01

    New experimental data on 2+ energies of 136,138Sn confirm the trend of lower 2+ excitation energies of even–even tin isotopes with > 82 compared to those with N < 82. However, none of the theoretical predictions using both realistic and empirical interactions can reproduce experimental data on excitation energies as well as the transition probabilities ((2; 6+ → 4+)) of these nuclei, simultaneously, apart from the ones whose matrix elements have been changed empirically to produce mixed seniority states by weakening the pairing. We have shown that the experimental result also shows good agreement with the theory in which three-body forces have been included in a realistic interaction. The new theoretical results on transition probabilities are discussed to identify the experimental quantities which will clearly distinguish between different views.

  4. Axions and SN 1987A: Axion trapping

    Science.gov (United States)

    Burrows, Adam; Ressell, M. Ted; Turner, Michael S.

    1990-01-01

    If an axion of mass between about 10(exp -3) and 10 eV exists, axion emission would have significantly affected the cooling of the nascent neutron star associated with SN 1987A. For an axion of mass greater than about 10(exp -2) eV axions would, like neutrinos, have a mean-free path that is smaller than the size of a neutron star, and thus would become trapped and radiated from an axion sphere. The trapping regime is treated by using numerical models of the initial cooling of a hot neutron star that incorporate a diffusion approximation for axion-energy transport. The axion opacity due to inverse nucleon-nucleon, axion bremsstrahlung is computed; and then the numerical models are used to calculate the integrated axion luminosity, the temperature of the axion sphere, and the effect of axion emission on the neutrino bursts detected by the Kamiokande II (KII) and Irvine-Michigan-Brookhaven (IMB) water-Cherenkov detectors. The larger the axion mass, the stronger the trapping and the smaller the axion luminosity. The estimate of the axion mass is confirmed above which trapping is so strong that axion emission does not significantly affect the neutrino burst. Based upon the neutrino-burst duration - the most sensitive barometer of axion cooling - it is concluded that for an axion mass greater than about 3 eV axion emission would not have had a significant effect on the neutrino bursts detected by KII and IMB. It is strongly suggested that an axion with mass in the interval 10(exp -3) to 3 eV is excluded by the observation of neutrinos from SN 1987A.

  5. Microwave study of superconducting Sn films above and below percolation

    Science.gov (United States)

    Beutel, Manfred H.; Ebensperger, Nikolaj G.; Thiemann, Markus; Untereiner, Gabriele; Fritz, Vincent; Javaheri, Mojtaba; Nägele, Jonathan; Rösslhuber, Roland; Dressel, Martin; Scheffler, Marc

    2016-08-01

    The electronic properties of superconducting Sn films ({T}{{c}}≈ 3.8 {{K}}) change significantly when reducing the film thickness down to a few {nm}, in particular close to the percolation threshold. The low-energy electrodynamics of such Sn samples can be probed via microwave spectroscopy, e.g. with superconducting stripline resonators. Here we study Sn thin films, deposited via thermal evaporation—ranging in thickness between 38 and 842 {nm}—which encompasses the percolation transition. We use superconducting Pb stripline resonators to probe the microwave response of these Sn films in a frequency range between 4 and 20 {GHz} at temperatures from 7.2 down to 1.5 {{K}}. The measured quality factor of the resonators decreases with rising temperature due to enhanced losses. As a function of the sample thickness we observe three regimes with significantly different properties: samples below percolation, i.e. ensembles of disconnected superconducting islands, exhibit dielectric properties with negligible losses, demonstrating that macroscopic current paths are required for appreciable dynamical conductivity of Sn at GHz frequencies. Thick Sn films, as the other limit, lead to low-loss resonances both above and below T c of Sn, as expected for bulk conductors. But in an intermediate thickness regime, just above percolation and with labyrinth-like morphology of the Sn, we observe a quite different behavior: the superconducting state has a microwave response similar to the thicker, completely covering films with low microwave losses; but the metallic state of these Sn films is so lossy that resonator operation is suppressed completely.

  6. 关于柯西sn-对称空间的一个注记%A Note on Cauchy sn-Symmetric Spaces

    Institute of Scientific and Technical Information of China (English)

    陈内萍

    2013-01-01

    It is proved that a space is a Cauchy sn-symmetric space if and only if it has a sn-devel-opment consisting of cs-covers ( or sn-covers) if and only if it is a sequence-covering π-image of a metric space .%证明了一个空间是柯西sn-对称空间当且仅当它有一个由cs-复盖或sn-复盖组成sn-展开当且仅当它是度量空间的序列复盖π映射。

  7. Bike to work week 2001 : final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The 2001 seventh annual bike to work week in Greater Victoria was a success, as more than 3000 cyclist participated, up 50 per cent from year 2000 and double that of 1999. The event earned Greater Victoria the title of Cycling Capital of Canada for 2001. Participants were rewarded with the realization of the many benefits of riding a bicycle for transportation, including: improved sense of well-being, reduced employee illness, reduced financial costs of the automobile to users, employers and taxpayers, and reduced traffic congestion and danger. The environmental benefit is the reduced environmental impact of automobile commuting including: reduced air and noise pollution, no need for road and parking space, and reduced depletion of non-renewable resources. The promotion of safe and responsible cycling was an essential part of the bike to work cycling campaign. Traffic safety problems were addressed through education, enforcement, engineering and policy. figs.

  8. Medical image of the week: DAH

    Directory of Open Access Journals (Sweden)

    Whitmore SP

    2013-03-01

    Full Text Available A 59 year old female was admitted to the ICU with hypoxemic respiratory failure and a clinical picture of ARDS (Figure 1, requiring intubation and mechanical ventilation. She underwent bone marrow and renal transplantation several years prior for multiple myeloma and myeloma kidney, respectively. She had been restarted on lenalidomide one month prior to presentation. She was also taking tacrolimus, mycophenolate, prophylactic antimicrobials, warfarin for deep venous thrombosis, and aspirin for coronary artery disease. Emergent bronchoscopy with bronchoalveolar lavage revealed progressively bloodier specimens (Figure 2 consistent with diffuse alveolar hemorrhage (DAH. Further work-up was negative for vasculitis. Her lenalidomide, anticoagulation, and trimethoprim/sulfamethoxazole was stopped. She was started on high dose steroids and improved over 2 weeks.

  9. Spark plasma-sintered Sn-based intermetallic alloys and their Li-storage studies

    CSIR Research Space (South Africa)

    Nithyadharseni, P

    2016-06-01

    Full Text Available In the present study, SnSb, SnSb/Fe, SnSb/Co, and SnSb/Ni alloy powders processed by co-precipitation were subjected to spark plasma-sintering (SPS) at 400 °C for 5 min. The compacts were structurally and morphologically characterized by X...

  10. Shell Model Description of Neutron-Deficient Sn Isotopes

    Institute of Scientific and Technical Information of China (English)

    Erdal Dikmen

    2009-01-01

    The shell model calculations in the sdgh major shell for the neutron-deficient 106,107,108,109Sn isotopes have been carried out by using CD-Bonn and Nijmegenl two-body effective nucleon-nucleon interactions. The single-shell states and the corresponding matrix elements needed for describing Sn isotopes are reconstructed to calculate the coefficient of fractional parantage by reducing the calculation requirements. This reconstruction allows us to do the shell model calculations of the neutron deficient Sn isotopes in very reasonable time. The results are compared to the recent high-resolution experimental data and found to be in good agreement with experiments.

  11. Cs5Sn9(OH·4NH3

    Directory of Open Access Journals (Sweden)

    Ute Friedrich

    2014-06-01

    Full Text Available The title compound, pentacaesium nonastannide hydroxide tetraammonia, crystallized from a solution of CsSnBi in liquid ammonia. The Sn94− unit forms a monocapped quadratic antiprism. The hydroxide ion is surrounded by five caesium cations, which form a distorted quadratic pyramidal polyhedron. A three-dimensional network is formed by Cs—Sn [3.8881 (7 Å to 4.5284 (7 Å] and Cs—NH3 [3.276 (7–3.636 (7 Å] contacts.

  12. Thermodynamic Properties of Liquid Ag-Bi-Sn Alloys

    Science.gov (United States)

    Li, Zuoan; Knott, Sabine; Mikula, Adolf

    2007-01-01

    As a promising lead-free solder, the thermodynamic properties of the liquid ternary Ag-Bi-Sn system were investigated. Using an appropriate galvanic cell, the partial free energies of Sn in liquid Ag-Bi-Sn alloys were determined as a function of concentration and temperature. Thermodynamic properties were obtained for 27 alloys. Their composition was situated on three cross sections with the constant ratios of Ag:Bi = 2:1, 1:1, and 1:2. The integral Gibbs free energy and the integral enthalpy for the ternary system at 900 K were calculated by Gibbs Duhem integration.

  13. GeSn/Si Avalanche Photodetectors on Si substrates

    Science.gov (United States)

    2016-09-16

    Photodetectors on Si substrates Report Title In this project, firstly, the material growth of GeSn by chemical vapor deposition (CVD) system has been...between GeSn and other market dominating IR detectors in short-IR wavelength (First time reported the D* of a GeSn detector in the world). The D* of...Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 Final Report W911NF-13-1-0196 64461-EL-DRP.43 479-575-7265 a. REPORT 14. ABSTRACT 16

  14. How is really decelerating the expansion of SN1993J?

    CERN Document Server

    Marcaide, J M; Pérez-Torres, M A; Guirado, J C; Lara, L; Ros, E; Diamond, P J; Mantovani, F; Shapiro, I I; Weiler, K W; Preston, R A; Schilizzi, R T; Sramek, R A; Trigilio, C; Van Dyk, S D; Whitney, A R

    2002-01-01

    SN1993J is to date the radio supernova whose evolution has been monitored in greatest detail and the one which holds best promise for a comprehensive theoretical-observational analysis. The shell-like radio structure of SN1993J has expanded in general accord with models of shock excited emission, showing almost circular symmetry for over 8 years, except for a bright feature at the south-eastern region of the shell that has been observed at every epoch. The spectrum of SN1993J has flattened from alpha =-1 to alpha =-0.67 (S_(\

  15. Simple Preparation of the Photocatalyst of Sn2+-doped Titania

    Institute of Scientific and Technical Information of China (English)

    Dao Rong LI; Ling Na SUN; Chang Wen HU

    2006-01-01

    Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn2+-doped titania photocatalyst was studied in this paper. The as-prepared samples were studied by UV-Vis, XRD, XPS, TEM. The particles of Sn2+-doped TiO2 photocatalyst, calcined from 150 to 600 ℃ for 5 h, possesses narrow particle size distribution and the sample was composed of anatase phase. Its photocatalytic efficiency was investigated by UV irradiation.

  16. The rotational spectra, potential function, Born-Oppenheimer breakdown, and magnetic shielding of SnSe and SnTe.

    Science.gov (United States)

    Bizzocchi, Luca; Giuliano, Barbara M; Hess, Mareike; Grabow, Jens-Uwe

    2007-03-21

    The pure rotational spectra of 27 isotopic species of SnSe and SnTe have been measured in the frequency range of 5-24 GHz using a Fabry-Perot-type resonator pulsed-jet Fourier-transform microwave spectrometer. Gaseous samples of both chalcogenides were prepared by laser ablation of suitable target rods and were stabilized in supersonic jets of Ar. Global multi-isotopolog analyses of all available high-resolution data produced spectroscopic Dunham parameters Y01, Y11, Y21, Y31, Y02, and Y12 for both species, as well as Born-Oppenheimer breakdown (BOB) coefficients delta01 for Sn, Se, and Te. A direct fit of the same data sets to an appropriate radial Hamiltonian yielded analytic potential energy functions and BOB radial functions for the X 1Sigma+ electronic state of both SnSe and SnTe. Additionally, the magnetic hyperfine interaction produced by the dipolar nuclei 119Sn, 117Sn, 77Se, and 125Te was observed, yielding first determinations of the corresponding spin-rotation coupling constants.

  17. Gap states in the electronic structure of SnO2 single crystals and amorphous SnOx thin films

    Science.gov (United States)

    Haeberle, J.; Machulik, S.; Janowitz, C.; Manzke, R.; Gaspar, D.; Barquinha, P.; Schmeißer, D.

    2016-09-01

    The electronic structure of a SnO2 single crystal is determined by employing resonant photoelectron spectroscopy. We determine the core level, valence band, and X-ray absorption (XAS) data and compare these with those of amorphous SnOx thin films. We find similar properties concerning the data of the core levels, the valence band features, and the absorption data at the O1s edge. We find strong signals arising from intrinsic in-gap states and discuss their origin in terms of polaronic and charge-transfer defects. We deduce from the XAS data recorded at the Sn3d edge that the Sn4d10 ground state has contributions of 4d9 and 4d8 states due to configuration interaction. We identify localized electronic states depending on the strength of the 4d-5s5p interaction and of the O2p-to-Sn4d charge-transfer processes, both appear separated from the extended band-like states of the conduction band. For the amorphous SnOx thin films, significant differences are found only in the absorption data at the Sn3d-edge due to a stronger localization of the in-gap states.

  18. Phase Transformations during the Reaction Heat Treatment of Internal Tin Nb$_{3}$Sn Strands with High Sn Content

    CERN Document Server

    Scheuerlein, C; Arnau-Izquierdo, G; Buta, F

    2008-01-01

    The phase transformations that occur during the reaction heat treatment of Nb3Sn superconductors depend on the overall elemental composition of the strand sub-elements. In the case of modern high Jc strands with a relatively low Cu content, liquid phases are present during large temperature intervals and phases that can be detrimental for the microstructural and microchemical homogeneity of the fully reacted strand are formed. We report synchrotron x-ray diffraction measurements during in-situ reaction heat treatment of a state-of-the-art high Jc Nb3Sn Internal Tin (IT) strand. In this strand Cu3Sn is formed upon Cu6Sn5 decomposition at 415 °C, a Sn-rich ternary Cu-Nb-Sn phase is detected in the approximate temperature interval 345-575°C and NbSn2 is present in the temperature interval 545-630°C. The formation of voids in the strand sub-elements has been monitored by synchrotron micro-tomography during in-situ reaction heat treatment.

  19. Band alignments at strained Ge1‑x Sn x /relaxed Ge1‑y Sn y heterointerfaces

    Science.gov (United States)

    Lan, H.-S.; Liu, C. W.

    2017-04-01

    Type-I, type-II, reverse type-I, and reverse type-II band alignments are found theoretically in strained Ge1‑x Sn x (0  ⩽  x  ⩽  0.3) grown on relaxed Ge1‑y Sn y substrates (0  ⩽  y  ⩽  0.3) using the model-solid theory. The prerequisite bandgaps, and energy difference between the top valence band edge and the average valence band position of GeSn are obtained by the nonlocal empirical pseudopotential method. For the indirect-gap (L valleys) Ge1‑x Sn x on relaxed Ge1‑y Sn y , the band alignments are type-I and reverse type-I under biaxial compressive strain (x  >  y) and biaxial tensile strain (x  <  y), respectively. For the direct-gap (Γ valley) Ge1‑x Sn x on relaxed Ge1‑y Sn y , the biaxial compressive strain yields type-I and type-II alignment, while the biaxial tensile strain yields reverse type-I and reverse type-II alignments.

  20. Structural Behavior of Pt-Sn Supported on MgO

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N. [Instituto Mexicano del Petroleo, Simulacion Molecular (Mexico); Morales, M. A.; Vanoni, W. [Centro Brasileiro de Pesquisas Fisicas (Brazil); Toledo, J. A. [Instituto Mexicano del Petroleo, Simulacion Molecular (Mexico); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fisicas (Brazil); Viveros, T. [Universidad Autonoma Metropolitana-Iztapalapa, area de Ingenieria Quimica (Mexico)

    2001-05-15

    Pt-Sn supported on magnesia and alumina were characterized, before and after treatment with hydrogen, by Moessbauer spectroscopy and X-ray diffraction. For the calcined samples on both supports tin is present as SnO{sub 2} and platinum as metal. After reduction with hydrogen, platinum and tin diffuse into the magnesia lattice to form a solid solution. On alumina Sn(IV), Sn(II), Sn(0), Pt, Pt{sub 3}Sn, PtSn and PtSn{sub 2} alloys are formed. The SnO interacts strongly with the alumina support. The catalytic activity of both Pt-Sn catalysts is strongly affected by the support. On alumina the dehydrogenation of cyclohexane is very high, whereas that on magnesia is almost non-active.

  1. Isothermal section at 1400 deg. C of the Ti-Zr-Sn system

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: ssaltykov@ipms.kiev.ua; Meleshevich, K.A.; Samelyuk, A.V.; Verbytska, O.M.; Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)

    2008-07-14

    By the methods of X-ray diffraction, metallography and microprobe examinations the character of phase equilibria at 1400 deg. C is studied for the Ti-(Ti,Zr){sub 5}Sn{sub 3}-Zr region of the Ti-Zr-Sn system. The isothermal section at 1400 deg. C is constructed. This is similar to the solidus surface and is characterized by two 3-phase regions: <{beta}Ti,Zr> + Ti{sub 3}Sn + (Ti,Zr){sub 5}Sn{sub 3} and Ti{sub 3}Sn + Ti{sub 2}Sn + (Ti,Zr){sub 5}Sn{sub 3}. Solubility of Sn in <{beta}Ti,Zr> solid solution is between 10 and 15 at.% Sn. Solubility of zirconium in Ti{sub 3}Sn is about 12 at.%.

  2. Defect-free high Sn-content GeSn on insulator grown by rapid melting growth

    Science.gov (United States)

    Liu, Zhi; Cong, Hui; Yang, Fan; Li, Chuanbo; Zheng, Jun; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

    2016-12-01

    GeSn is an attractive semiconductor material for Si-based photonics. However, large lattice mismatch between GeSn and Si and the low solubility of Sn in Ge limit its development. In order to obtain high Sn-content GeSn on Si, it is normally grown at low temperature, which would lead to inevitable dislocations. Here, we reported a single-crystal defect-free graded GeSn on insulator (GSOI) stripes laterally grown by rapid melting growth (RMG). The Sn-content reaches to 14.2% at the end of the GSOI stripe. Transmission electron microscopy observation shows the GSOI stripe without stacking fault and dislocations. P-channel pseudo metal-oxide-semiconductor field effect transistors (MOSFETs) and metal-semiconductor-metal (MSM) Schottky junction photodetectors were fabricated on these GSOIs. Good transistor performance with a low field peak hole mobility of 402 cm2/Vs is obtained, which indicates a high-quality of this GSOI structure. Strong near-infrared and short-wave infrared optical absorption of the MSM photodetectors at 1550 nm and 2000 nm were observed. Owing to high Sn-content and defect-free, responsivity of 236 mA/W@-1.5 V is achieved at 1550 nm wavelength. In addition, responsivity reaches 154 mA/W@-1.5 V at 2000 nm with the optical absorption layer only 200 nm-thick, which is the highest value reported for GeSn junction photodetectors until now.

  3. Evaporation Mechanism of Sn and SnS from Liquid Fe: Part I: Experiment and Adsorption of S on Reaction Site

    Science.gov (United States)

    Jung, Sung-Hoon; Kang, Youn-Bae; Seo, Jeong-Do; Park, Joong-Kil; Choi, Joo

    2015-02-01

    In order to evaluate feasibility of Sn-containing ferrous scrap recycling by evaporation of Sn, a number of liquid-gas experiments were carried out using an electromagnetic levitation melting technique. Rate of decrease of Sn concentration in liquid steel droplets by evaporation in Ar-H2 gas mixture was determined at 1873 K (1600 °C). Evaporation rate of the Sn under various conditions (various flow rates of the gas mixture, initial S concentration, [pct Sn]0) was examined using previously reported rate equations. Increasing flow rate increased the evaporation rate of Sn initially, but the rate became constant at higher flow rate, which indicates that the rate-controlling step is the chemical reaction at the liquid/gas interface. Increasing initial S concentration significantly increased the evaporation rate of Sn, which is in good agreement with previous understanding that Sn could be evaporated as SnS(g). It was found in the present study that neither a simple first-order reaction (rate proportional to [pct Sn]) nor a second-order reaction (rate proportional to [pct Sn] × [pct S]) could account for the Sn evaporation under a chemical-reaction-controlled regime. It is proposed in the present study that surface adsorption of S should be taken into account in order to interpret the evaporation rate of Sn in such a way that S blocks available sites for SnS evaporation on the liquid steel. The ideal Langmuir isotherm was applied in order to better represent evaporation rate constant k SnS as a function of [pct S] (0.06 reaction Sn i + S i = SnSi(g), , is 2.57 × 10-8 m4 mol-1 s-1.

  4. Comparative study of SnS recrystallization in molten CdI{sub 2}, SnCl{sub 2}and KI

    Energy Technology Data Exchange (ETDEWEB)

    Timmo, Kristi; Kauk-Kuusik, Marit; Pilvet, Maris; Mikli, Valdek; Kaerber, Erki; Raadik, Taavi; Leinemann, Inga; Altosaar, Mare; Raudoja, Jaan [Department of Materials Science, Tallinn University of Technology, Tallinn (Estonia)

    2016-01-15

    In the present study, the recrystallization of polycrystalline SnS in different molten salts CdI{sub 2}, SnCl{sub 2} and KI as flux materials are presented. The recrystallization and growth of polycrystalline material in molten salts produces unique SnS monograin powders usable in monograin layer solar cells. XRD and Raman analysis revealed that single phase SnS powder can be obtained in KI at 740 C and in SnCl{sub 2} at 500 C. Long time heating of SnS in molten CdI{sub 2} was accompanied by chemical interaction between SnS and CdI{sub 2} that resulted in a mixture of CdS and Sn{sub 2}S{sub 3} crystals. SEM images showed that morphology of crystals can be controlled by the nature of the flux materials: needle-like Sn{sub 2}S{sub 3} together with round edged crystals of CdS in CdI{sub 2}, flat crystals of SnS with smooth surfaces in SnCl{sub 2} and well-formed SnS crystals with rounded edges in KI had been formed. The temperatures of phase transitions and/or the interactions of SnS and flux materials were determined by differential thermal analysis. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

    Science.gov (United States)

    Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

    2017-05-01

    The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

  6. High-pressure / High-temperature studies on the stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd)

    Energy Technology Data Exchange (ETDEWEB)

    Riecken, J.F.; Hermes, W.; Rodewald, U.C.; Hoffmann, R.D.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2008-06-15

    The normal-pressure (NP) orthorhombic TiNiSi-type (space group Pnma) stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd) were transformed into the corresponding hexagonal ZrNiAl-type (space group P anti 62m) high-pressure (HP) modifications under multianvil high-pressure (7.5 - 11.5 GPa) high-temperature (1100 - 1200 C) conditions. The structures of NP-CeNiSn, HP-PrNiSn, NP-NdNiSn, HP-LaPdSn, HP-PrPdSn, and HP-NdPdSn were refined from single crystal X-ray diffractometer data. Structural data for HP-SmNiSn were obtained from a Rietveld powder refinement. The high-pressure phase transition significantly changes the rare earth coordination, i. e. 4 RE + 6 Ni(Pd) + 6 Sn atoms for the NP-phases and 6 RE + 5 Ni(Pd) + 6 Sn atoms for the HP-phases. Susceptibility measurements of HP-PrPdSn and HP-NdPdSn reveal paramagnetic behavior with experimental magnetic moments of 3.61(1) {mu}{sub B}/Pr atom and 3.66(1) {mu}{sub B}/Nd atom, respectively. Low-temperature susceptibility and specific heat data point to inhomogeneous magnetism and spin-glass behavior, respectively. (orig.)

  7. SN 2009ip and SN 2010mc: Early and late-time behavior consistent with core-collapse Type IIn supernovae

    CERN Document Server

    Smith, Nathan; Prieto, Jose

    2013-01-01

    The recent supernova (SN) 2009ip had pre-SN eruptions followed by a final explosion in 2012. Its pre-SN observations make 2009ip the best observed SN progenitor in history, but the unprecedented data on the pre-SN activity has fueled debate about the nature of the 2012 explosion, whether it was a true SN or some extreme non-terminal event. In principle, both types of events could power shock interaction with circumstellar material (CSM), but here we argue that only a core-collapse SN provides a self-consistent explanation. Previously, we demonstrated that the light curves of SN 2009ip and another Type IIn, SN 2010mc, were nearly identical. Here we expand that comparison to their spectra as well, demonstrating that they are both consistent with known Type IIn events. The late-time spectra of SN 2009ip resemble those of the super-luminous SN 2006tf, and the underlying broad component in SN 2009ip's spectra resembles Type II-P events. The recent claim that the late-time spectrum of SN 2009ip is returning to its ...

  8. Weekly and Twice-Weekly Yoga Classes Offer Similar Low-Back Pain Relief in Low-Income Minority Populations

    Science.gov (United States)

    ... W X Y Z Weekly and Twice-Weekly Yoga Classes Offer Similar Low-Back Pain Relief in ... an NCCAM-funded study found that once-weekly yoga classes relieved pain, improved function, and reduced the ...

  9. Investigation by Mössbauer spectroscopy of Sn redox transformations during H2/O2 titration on Pt/Al2O3Sn-Cl and Pt/Al2O3SnIn-Cl naphtha reforming catalysts

    Science.gov (United States)

    Jahel, Ali; Avenier, Priscilla; Lacombe, Sylvie; Olivier-Fourcade, Josette; Jumas, Jean-Claude

    2010-03-01

    Bimetallic Pt/Al2O3Sn-Cl and trimetallic Pt/Al2O3SnIn-Cl catalysts were characterized by H2/O2 double titration and 119Sn Mössbauer spectroscopy. The addition of Sn or both Sn and In to the monometallic Pt/Al2O3-Cl catalyst leads to an increase in the volume of chemisorbed O2 at each titration. For bimetallic and trimetallic catalysts the increase in the Pt dispersion, calculated from the second oxygen titre, abnormally surpasses the barrier of 100%. Characterization of samples obtained after each step of the H2/O2 titration sequence using 119Sn Mössbauer spectroscopy allowed to follow the redox transformations of Sn species suspected of contributing to O2 consumption. 119Sn Mössbauer spectra show that after reduction unalloyed metalic Sn and PtSn alloy phases are formed in bi- and trimetallic catalysts respectively. These metallic phases are oxidized upon the first oxygen titre into the so-called PtxSn(O) oxometalic phases. The index calculated from this titre thus expresses the Pt-Sn bimetallic character and is called the bimetallicity index (BMI). These latter phases further undergo reduction and regeneration (oxidation) upon the second O2 titre and thus contribute to the calculated Pt dispersion as well.

  10. Microstructural investigation and SnO nanodefects in spray-pyrolyzed SnO2 thin films

    DEFF Research Database (Denmark)

    Thanachayanont, Chanchana; Yordsri, Visittapong; Boothroyd, Chris

    2011-01-01

    Spray pyrolysis is one of the most cost-effective methods to prepare SnO2 films due to its ability to deposit large uniform area, low fabrication cost, simplicity and low deposition temperature. Conventionally, scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) are routinely used...... to investigate microstructure and crystal structure of the SnO2 films. In the present study, the SnO2 films were deposited by spray pyrolysis at 300, 400 and 500°C and the microstructure of the 500°C film was further examined by using transmission electron microscopy (TEM) and convergent beam electron...

  11. Mercedes-Benz Fashion Week light lifestyle Fashion Week achieved new breakthroughs

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    March 24,Mercedes-Benz China International Fashion Week(2012/2013 autumn and winter series) opened in Beijing.During the nine days Fashion Week,more than 60 activities were held, of which 46 brands and institutions from home and abroad,more than 30 Chinese and foreign designers and nearly 400 designs and models rookie participated in 41 fashion publishings and entered 6 professional contest finals.Compare with the event last year,the size of the current China Inter-

  12. Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh

    CERN Document Server

    Jerkstrand, A; Smartt, S J; Fransson, C; Sollerman, J; Taubenberger, S; Bersten, M; Spyromilio, J

    2014-01-01

    We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modeling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modeling of the [O I] 6300, 6364 lines constrains the progenitors of these three SNe to the M_ZAMS=12-16 M_sun range (ejected oxygen masses 0.3-0.9 M_sun), with SN 2011dh towards the lower end and SN 1993J towards the upper end of the range. The high ejecta masses from M_ZAMS >= 17 M_sun progenitors give rise to brighter nebular phase emission lines than observed. Nucleosynthesis analysis thus supports a scenario of low/moderate mass progenitors for Type IIb SNe, and by implication an origin in binary syste...

  13. Franz-Keldysh effect in GeSn pin photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Oehme, M., E-mail: oehme@iht.uni-stuttgart.de; Kostecki, K.; Schmid, M.; Kaschel, M.; Gollhofer, M.; Ye, K.; Widmann, D.; Koerner, R.; Bechler, S.; Kasper, E.; Schulze, J. [Institut für Halbleitertechnik, Universität Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)

    2014-04-21

    The optical properties and the Franz-Keldysh effect at the direct band gap of GeSn alloys with Sn concentrations up to 4.2% at room temperature were investigated. The GeSn material was embedded in the intrinsic region of a Ge heterojunction photodetector on Si substrates. The layer structure was grown by means of ultra-low temperature molecular beam epitaxy. The absorption coefficient as function of photon energy and the direct bandgap energies were determined. In all investigated samples, the Franz-Keldysh effect can be observed. A maximum absorption ratio of 1.5 was determined for 2% Sn for a voltage swing of 3 V.

  14. Beta-decay studies near {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Karny, M.; Janas, Z.; Miernik, K.; Plochocki, A.; Zylicz, J. [University of Warsaw, Institute of Experimental Physics, Warsaw (Poland); Batist, L. [St. Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Banu, A.; Becker, F.; Burkard, K.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Kirchner, R.; Mandal, S.; Mazzocchi, C.; Mukha, I.; Plettner, C.; Roeckl, E.; Schaedel, M. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany); Blazhev, A. [GSI, Darmstadt (Germany); Sofia Univ. (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen, Muenchen (Germany); Jungclaus, A. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Kavatsyuk, M.; Kavatsyuk, O. [GSI, Darmstadft (Germany); Taras Shevchenko Kiev National University, Kiev (Ukraine); La Commara, M.; Romoli, M. [Universita ' ' Federico II' ' and INFN Napoli, Dipartimento Scienze Fisiche, Napoli (Italy); Muralithar, S. [GSI, Darmstadt (Germany); Nuclear Science Center, New Delhi (India); Rykaczewski, K. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Schmidt, K. [Continental Teves AG and Co., Frankfurt am Main (Germany); Schwengner, R. [Forschungszentrum Rossendorf, Dresden (Germany)

    2005-09-01

    The {beta}-decay of {sup 102}Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the {gamma}-{gamma} coincidence data. The total experimental Gamow-Teller strength B{sub GT}{sup exp} of {sup 102}Sn was deduced from the TAS data to be 4.2(9). A search for {beta}-delayed {gamma}-rays of {sup 100}Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of {sup 100}Sn in fusion-evaporation reaction between {sup 58}Ni beam and {sup 50}Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei. (orig.)

  15. The Competitive Relationships of SN2, SN1, E2, E1 Reactions in Organic Chemistry%有机化学中SN2,SN1,E2,E1反应的相互竞争关系

    Institute of Scientific and Technical Information of China (English)

    颜志明; 潘英明

    2014-01-01

    有机化学中的SN2,SN1,E2,E1反应在学习中有着重要的作用,同时也是学习中易混淆的知识点.通过总结它们的反应机理、反应影响因素和反应相互竞争关系图,并利用竞争关系图解答了一些典型考研真题,方便读者理解和掌握SN2,SN1,E2,E1反应的相互竞争关系.

  16. Medical image of the week: aspergilloma

    Directory of Open Access Journals (Sweden)

    Hsu W

    2014-05-01

    Full Text Available No abstract available. Article truncated after 150 words. A 69-year-old woman, a current smoker, with very severe chronic obstructive pulmonary disease and prior atypical mycobacterium, was found unresponsive by her family and intubated in the field by emergency medical services for respiratory distress. Her CT thorax showed severe emphysematous disease, apical bullous disease, and a large left upper lobe cavitation with debris (Figure 1. She was treated with broad-spectrum antibiotics and anti-fungal medications. Hemoptysis was never seen. Sputum cultures over a span of two weeks repeatedly showed Aspergillus fumigatus and outside medical records confirmed the patient had a known history of stable aspergilloma not requiring therapy. Aspergillomas usually arises in cavitary areas of the lung damaged by previous infections. The fungus ball is a combination of colonization by Aspergillus hyphae and cellular debris. Individuals with aspergillomas are usually asymptomatic or have mild symptoms (chronic cough and do not require treatment unless it begins to invade into the cavity ...

  17. The new Bulletin arrives in two weeks

    CERN Multimedia

    2006-01-01

    In May, you will discover a redesigned CERN Bulletin. Starting with the first May issue (No. 19-20/2006), the format of the CERN Bulletin will change completely. The page layout will be more attractive, reminiscent of a proper newspaper, with pictograms to identify the different sections. The information provided will also be more visible. The Bulletin was much in need of a makeover as its current layout dates back to 1976! The introduction of the new format will coincide with the introduction of a new means of distribution. You will still receive the elctronic version of the Bulletin every week directly on your computer. However, in order to avoid the waste from the dozens of copies that linger unread in people's mailboxes, the paper version will be available at a series of distribution points around the Laboratory. You will find the Bulletin along with the Staff Association newsletter at the cafeteria closest to your office. The Bulletin will be available from the following distribution points: On the M...

  18. Effect of Sn on methane decomposition over Fe supported catalysts to produce carbon

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Patricia F.; Ribeiro, Leandro P.; Rosmaninho, Marcelo G. [ICEx. Universidade Federal de Minas Gerais (UFMG), Departamento de Quimica (Brazil); Ardisson, Jose D. [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN), Laboratorio de Fisica Aplicada (Brazil); Dias, Anderson [Universidade Federal de Ouro Preto (UFOP), Departamento de Quimica (Brazil); Lago, Rochel M., E-mail: rochel@qui.ufmg.br [ICEx. Universidade Federal de Minas Gerais (UFMG), Departamento de Quimica (Brazil)

    2011-11-15

    In this work, alumina-supported Sn containing Fe catalysts were investigated in CVD reactions (Chemical Vapor Deposition) using methane for carbon production. The catalysts were prepared with 10 wt.% of Fe (as Fe{sub 2}O{sub 3}) and 3, 6 and 12 wt.% of Sn (as SnO{sub 2}) supported on Al{sub 2}O{sub 3} named hereon Fe10Sn3A, Fe5Sn6A and Fe10Sn12A, respectively. These catalysts were characterized by SEM, TPCVD, TPR, TG, Raman, XRD and {sup 57}Fe and {sup 119}Sn Moessbauer spectroscopy. Methane reacts with Fe10A catalyst (without Sn) in the temperature range 680-900 Degree-Sign C to produce mainly Fe{sup 0}, Fe{sub 3}C and 20 wt.% of carbon deposition. TPR and TPCVD clearly showed that Sn strongly hinders the CH{sub 4} reaction over Fe catalyst. {sup 57}Fe Moessbauer suggested that in the presence of Sn the reduction of Fe{sup + 3} by methane becomes very difficult. {sup 119}Sn Moessbauer showed Sn{sup + 4} species strongly interact with metallic iron after CVD, producing iron-tin phases such as Fe{sub 3}SnC and FeSn{sub 2}. This interaction Sn-Fe increases the CVD temperatures and decreases the carbon yield leading to the production of more organized forms of carbon such as carbon nanotubes, nanofibers and graphite.

  19. Effect of Sn on methane decomposition over Fe supported catalysts to produce carbon

    Science.gov (United States)

    Oliveira, Patrícia F.; Ribeiro, Leandro P.; Rosmaninho, Marcelo G.; Ardisson, José D.; Dias, Anderson; Lago, Rochel M.

    2011-11-01

    In this work, alumina-supported Sn containing Fe catalysts were investigated in CVD reactions (Chemical Vapor Deposition) using methane for carbon production. The catalysts were prepared with 10 wt.% of Fe (as Fe2O3) and 3, 6 and 12 wt.% of Sn (as SnO2) supported on Al2O3 named hereon Fe10Sn3A, Fe5Sn6A and Fe10Sn12A, respectively. These catalysts were characterized by SEM, TPCVD, TPR, TG, Raman, XRD and 57Fe and 119Sn Mössbauer spectroscopy. Methane reacts with Fe10A catalyst (without Sn) in the temperature range 680-900°C to produce mainly Fe0, Fe3C and 20 wt.% of carbon deposition. TPR and TPCVD clearly showed that Sn strongly hinders the CH4 reaction over Fe catalyst. 57Fe Mössbauer suggested that in the presence of Sn the reduction of Fe + 3 by methane becomes very difficult. 119Sn Mössbauer showed Sn + 4 species strongly interact with metallic iron after CVD, producing iron-tin phases such as Fe3SnC and FeSn2. This interaction Sn-Fe increases the CVD temperatures and decreases the carbon yield leading to the production of more organized forms of carbon such as carbon nanotubes, nanofibers and graphite.

  20. Lattice Dynamic of Ag8SnSe6 Crystal

    Directory of Open Access Journals (Sweden)

    I.V. Semkiv

    2016-10-01

    Full Text Available The synthesis and structure properties of Ag8SnSe6 argyrodite are described. Argyrodite belongs to the orthorhombic space group Pmn21 with 15 atoms per primitive cell. Classification of the main phonon modes of crystal carried out. First-principles phonon-dispersion curves for argyrodite Ag8SnSe6 are calculated. Peak position in Raman spectra and IR-spectra was clarified.