Dr. Guaciara M. dos Santos
 (Guaciara dos Santos Winston)
Research Project Scientist III

 
  


Earth System Science
University of California Irvine
B321 Croul Hall, Irvine, CA 92697-3100
(949) 824-9851 (office)
(949) 824-3674 (lab)
Fax: (949) 824-3874
e-mail: gdossant@uci.edu
Publications

 
PROFESSIONAL PREPARATION:
  • Ph.D in Physical Sciences specializing in Applied Nuclear Physics - March 1999
  • Masters in Physical Sciences specializing in Laser Spectroscopy - March 1995
  • General Physics Education: Undergrad. Teacher - 1995       
  • General Physics Science: Bachelor - 1992

APPOITMENTS:

Keck Carbon Cycle Accelerator Mass Spectrometry Facility, Earth System Science, UCI , USA :

  • Research Project Scientist III, KCCAMS Research Group, June 2011 - present
  • Research Project Scientist II, KCCAMS Research Group, June 2008 – 2011
  • Manager of the KCCAMS sample preparation laboratory, 2002 - present
  • Specialist I, KCCAMS Facility, 2006- 2008  
  • Associate Specialist III, KCCAMS Facility, 2004- 2006  
  • Associate Specialist I, KCCAMS Facility, 2002- 2004  
Responsibilities:
  • Carry on independent research on Biogeochemical cycle studies.
  • Help on operation and maintenance of a compact AMS system.
  • Train Postdocs, PhD candidates, undergrad students, research staff and outside visitors.
  • Deal with all aspects of sample preparation, measurement and analyses of samples in support of funded and collaborative research with UC and non-UC PIs.
  • Oversee day-to-day operation of laboratory.
  • Purchase equipment, replacement parts and consumables.
Research Focus:
  • 14C-AMS measurements on carbon occluded in phytoliths from soil and plant materials.
  • Study of source partitioning of soot-black carbon. 
  • Carbon in the oceans: Tracing natural processes with rare isotopes, Southern California coast.
  • Accelerator Mass Spectrometry (AMS) operation, developments and applications.
  • Ion-source development for AMS measurements.
  • Carbon cycle studies using radiocarbon and stable isotope measurements.
  • Quality control on graphite sample preparation for AMS measurements: background improvements, precision and reproducibility on regular and ultra-small graphite samples.

The Australian National University , ANU, Canberra , Australia : Post-doctoral Fellow, Accelerator Mass Spectrometry, April 1999 – until Nov 2001.

Research Focus:

  • Studies on ion-source principles and improvements, and target-pressing procedures and developments.
  • Design and build of graphitization systems.
  • Measurement set-ups and running, of a broad spectrum of isotopes (10Be, 14C, 26Al, 36Cl, 59Ni, 99Tc and Pu) for many applications on AMS.
  • Studies on conventional ionization chambers for heavy ion detection in AMS studies.
  • Design and testing of a complete detection system designated the Brazilian Bragg Curve Detector (BBCD) to be used on the Brazilian AMS program, originated in 1993 at the Universidade de São Paulo (USP), Brazil .
  • AMS sample preparation of the most important radioisotopes for the research community in Brazil (10Be, 14C and 36Cl).
  • Determination of the radiocarbon ages of Holocene fires in the Amazon rain forest, part of the Global Climate Change Program (collaborative work).
  • Graphite sample preparation techniques for samples beyond 50,000 years old.
INVITED TALKS AND DISCUSSION PANELS:
  • Invited speaker (lecture session) of the "International Workshop on Small Scale Radiocarbon Analysis, the Laboratory of Ion Beam Physics, ETH Zürich, Switzerland , September 2011
  • Invited speaker (plenary session) of the Ix Latin American Symposium on Nuclear Physics and Applications, Quito, Ecuador, July 18-22_2011.
  • Invited speaker, session convener and chair  for the 6th International Symposium "Radiocarbon and Archaeology", Paphos, Cyprus, April 10-15, 2011.
  • Member of the Scientific Advisory Panel (SAP) and chairman of the 12th Accelerator Mass Spectrometry Conference, Wellington, New Zealand, March 20-25, 2011.
  • 14C-AMS as a tool for archaeological investigation: Implications for Human Settlement in South America . Invited talk and paper for: "The peopling of the Americas " International Symposium, December 16 to 22, 2006 at the Capivara National Park , Piaui , Brazil
  • Graphitization Workshop organized by J. Turnbull & C. Prior, 20th International Radiocarbon Conference, Hawaii, May 03 to June 05, 2009 .
  • NOSAMS Compound Specific Radiocarbon Analyses (CSRA) Workshop, Woods Hole Oceanographic Institution, Sample Preparation, Ion Sources, Modern Accelerators—The Current State of the Art, June 29 and 30, 2010

AWARD AND HONORS:

  • May to November, 2001 - Bridging Post-doctoral Fellow - ANU, Canberra , Australia - granted by the Institute of Advanced Studies , Research School of Physical Sciences and Engineering, ANU. 1999-2001
  • Post-doctoral Fellow - ANU, Canberra, Australia - granted by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil.

PROFESSIONAL SOCIETIES:

Member of the Physical Society of Brazil (Sociedade Brasileira de Física)

Member of American Geophysical Union (AGU)

SUPERVISION AT KCCAMS FACILITY:

Postdoctoral and Undergrad Student Projects Mentored, Earth System Science Department, UCI , USA :

  • Co-advisor of Dr. Ben Fuller  (2011 - present).
  • Co-advisor of Dr. Simon Fahrni  (2011 - present).
  • Co-advisor of Dr. Julie Ferguson  (2010 - present).
  • Advisor of Shari Bush (May 2011 – present). Project Title: 14C-AMS carbonate samples screening.
  • Advisor of Hector Martinez (May 2011 – present). Project Title: 14C and Stable Isotope dietary Inferences in Modern Humans (fish intake).
  • Advisor of Kaelyn M. Ormsby (January 2010 – June). Project Title: 14C and Stable Isotope dietary Inferences in Modern Humans.
  • Co-advisor of Karla Acaylar (2009). Undergrad Senior Thesis Title: Time-Series Isotope Measurements (δ 13C and 14C) of Southern California Surface Seawater Dissolved Inorganic Carbon (DIC).
  • Advisor of Elise N. Hinger (2007 - 2009), Undergrad Project Title: Carbon Isotope Measurements of Surface Seawater from a Time-Series Site off Southern California . With this project Ms. Hinger received the Undergraduate Award in Research for 2008, and today she is at the Dept. Fish, Wildlife and Conservation Biology.
Technical personnel and lab students mentored (current):
  • Research Associate Specialist: Chanda Bertrand (December 2010 - present)
  • Student Lab Assistants: Dina Saleh (2011 - present), Shari Bush (May 2011 – present), Kimberly Padua (2010 - present), Hector Martinez De La Torre (2010 - present). 
  • Supervision of 14C-AMS sample preparation for numerous students, pos-docs and professionals from UCI and outside visitors.
  • Supervision and consultation on 14C-AMS sample preparation procedures and laboratory set up with numerous laboratories.
 Other technical personnel and lab students mentored (former):
  • Research Associate Specialist: Will Beaumont (2007 - 2010) 
  • Junior Associate Specialist: Robert K. Beverly (2006 - 2011)
  • Research Associate Specialist: Dr. Dachun Zhang (2005 -2007)
  • Student Lab Assistants: Kaelyn Orsmby (2009 - 2011), Jigna Patel (2009-2011), Nathan Yee (2009 - 2010), Shenil Patel (2008-2009), Kelly McKnight (2008), Denis Tauz (March 2007 - 2009),Christy Loo (March 2007 - 2009), Elise Hinger (2005 - 2009), Rachel B. Moore (2004 - 2008), Bita Hirsa (August of 2006 - January 2007), Robert K. Beverly (2004 - 2006), Sami Rifai (2004 - January of 2006), Diana Hsueh (2003 - 2004), Susana E. Gonzalez (summer of 2003), Maya Mazon (2002 - 2005), Kevin C. Druffel-Rodriguez (2002 - 2003), Shahla Ali (2002 - 2003) and Shaun Evola (2002).

BOOK CHAPTER (in preparation):

“The use of Radiocarbon combined with Stable Isotopes in Ecology and Earth System Science”, chapter 9 (Preparation for Radiocarbon Analysis), in Schuur and Trumbore Eds., in preparation.

INTERNAL TECHNICAL REPORTS (coauthored with laboratory assistants):

  • Swiping protocol - complete version (PDF file).
  • Acid/Base/Acid sample pre-treatment protocol (PDF file).
  • Combustion protocol (PDF file).
  • Graphitization protocol for organic and carbonate samples - Hydrogen reduction method (PDF file).
  • Pounding targets - UCI wheel and cathodes (PDF file).
  • Chemical Pretreatment for bone (PDF file).
  • Seawater Dissolved Inorganic Carbon Protocol (PDF file). Based on Sheila Griffin procedure.
 INTERNAL TECHNICAL REPORTS (principal author):
  • UCI KCCAMS Facility - AMS Settings to 14C measurements (PDF file).
  • Design and updates of the W. M. Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory web-page.

TEACHING EXPERIENCE:

2004 to 2011 - Associate in Instruction: UCI short course - "The use of 14C in Ecology and Earth System Science", Radiocarbon AMS sample preparation procedures of carbonaceous raw materials, AMS system operation, and data analyses.