Assistant Research Engineer


image002Kwangsam Na

Dr. Kwangsam Na is a research faculty member with the Cocker research group. His research has been related to the characterization of volatile organic compounds and fine particulate matter (PM2.5) in the atmosphere as well as engine exhaust. His research has been focused on secondary organic aerosol (SOA) formation from alkene-ozone reactions and photooxidation of aromatic hydrocarbon. This study provides an insight into the role of atmospheric chemistry in the change of ambient VOC and SOA concentrations. Measurement and chemical analysis of diesel engine exhaust are also his research topic of interest. Kwangsam obtained his Ph.D. in Chemical Engineering from Yonsei University, Seoul, South Korea in 2001. His dissertation was titled “Characteristics of Atmospheric Volatile Organic Compounds in Seoul: “Measurements and Chemical Mass Balance Receptor Modeling”.



Graduate Students


Ajay Kumar Chaudhary

Ajay Kumar Chaudhary is entering his fourth year as a Ph.D. student in the department of Chemical and Environmental Engineering. His research is centered around realtime particulate measurement of diesel exhaust and includes a detailed evaluation of the performance of the Dekati DMM and our own fast scanning mobility particle sizer.  He has applied these devices to obtain modal PM emissions measurements, which can be combined with engine operating parameters, to aid in the development of a PM module for CMEM.  Additional efforts include a chemical characterization of diesel exhaust from backup utility generators.  He received his Masters Degree from IIT-Bombay, Mumbai, India in Environmental Science and Engineering and Bachelors Degree from BIET-Jhansi, India in Mechanical Engineering. His Masters thesis was on modeling of particulate emissions from engine exhaust.


Kent Johnson

Mr. Johnson received his B.S Degree in Mechanical Engineering from California Polytechnic, San Luis Obispo in 1992, his M.S. Degree in Electrical Engineering Controls from California Polytechnic, Pomona in 2001, and is currently pursuing his PhD in Chemical and Environmental Engineering at UC Riverside. Mr. Johnson joined CE-CERT in January 1993 and was involved in CE-CERT’s solar hydrogen production facilities, was the lead CE-CERT engineer on the a biomass to fuels gasification pilot plant and since 2000 Mr. Johnson was the lead design engineer responsible for the development of the on-road mobile emissions laboratory (MEL). Since MEL’s design, he has been responsible for all technical and management details of emissions measurements such as interfacing research equipment, performing quality control, technical reporting, setting up tests, and processing all data from the laboratory. MEL meets the specifications of the CRF and has cross correlated with many other laboratories. MEL is considered a very reliable and accurate laboratory from regulators and industrial client’s perspective.

In addition to his normal CE-CERT work activities, he was involved in five student competition. The competitions involved solar energy and vehicle conversion to ethanol and propane fuels. Prior to CE-CERT his work experience included the Central Contra Costa Sanitary District (CCCSD), where he performed pilot tests to dry sludge indirectly with steam, designed the logic for a PLC controlled day bin purge valve, and reported on CCCSD's outfall toxicity level. Mr. Johnson also worked at BadischeStahl Werk GmbH (BSW) a German steel factory where he analyzed

steel properties and investigated methods for converting scrap metal into high quality steel.


image009Christopher Clark

Chris Clark is a 4th year Ph.D. student in the department of Chemical and Environmental Engineering.  Chris’s research interests include aerosol sizing and composition characterization using ion mobility spectrometry, reactor modeling using multiphysics software, and catalytic and non-catalytic reaction kinetics.  Chris received his B.S. and M.S. from West Virginia University in Chemical Engineering, in 2003 and 2005 respectively, with thesis research focusing on basic catalysis using molybdenum carbide.



image001Quentin Malloy

Quentin Malloy is a fifth a year graduate student in Dr. David Cocker's group. His research focuses on application of various mass spectrometry techniques to understanding the chemical composition of secondary organic aerosol. His primary focus is on understanding the atmospheric processes leading to uptake and incorporation of organic nitrogen in ambient aerosol. He has also applied mass spectrometry toward the understanding of aromatic and cyclic alkane chemistry in the atmosphere. As a secondary area of research he has examined the physical properties associated with secondary organic aerosol including density and hygroscopicity. He graduated in 2004 with a B.S in Chemical Engineering from the University of Missouri, Columbia.


image012Harshit Agrawal

Harshit Agrawal is a fourth year graduate student working under the guidance of Dr. David Cocker. His primary research focus is “Evaluation of Impacts of Marine Port Sources on Regional Air Quality”.

Harshit completed his B.Tech. from Indian Institute of Technology (IIT) - Bombay in 2005. He joined University of California, Riverside with a Dean’s fellowship in September 2005. In past two and half years he has been working on physical and chemical characterization of emissions from aircraft engines, and slow and medium speed marine diesel engines. He has also been working on comparison of different sources of diesel emissions. Harshit received Ester F. Hays graduate fellowship in 2007


image025Qi Li

Qi is a third year Ph.D. student in the department of Chemical and Environmental Engineering.Her research focuses on gas-to-particle processes occurring within the atmosphere. She is the lead student on the groups of new Aerodyne W-ToF-AMS system, which is being used to investigate chemical composition of aerosol particles formed within the UCR/CE-CERT atmospheric simulation chamber. She also works with instruments to characterize physical properties such as density, hygroscopicity and volatility of particles. She graduated from Peking University,China with a M.S. in Environmental Science.



image016Varalakshmi Jayaram

Varalakshmi Jayaram is a third year graduate student in the department of Chemical and Environmental Engineering. Her dissertation focuses on the effect of emission control technologies - fuels, after treatment devices and engine technology - on emissions from port sources. Lakshmi is the 2008 recipient of the Esther Hays Graduate Fellowship. She obtained her M.S. in Mechanical Engineering from Ohio University, Athen, OH in 2005 and B.Tech in Chemical Engineering from Sri Venkateshwara College of Engineering, Sriperumbudur, India in 2003.



image018Shunsuke Nakao

Shunsuke Nakao is a second year Ph.D. student in the department of Chemical and Environmental Engineering. He is interested in physical property and chemical composition of secondary organic aerosol (SOA). He worked on development of a real-time measurement system for particle density, and he utilizes analytical techniques for chemical speciation of SOA. Shunsuke received a B.S. in Applied Chemistry from Keio University, Japan in 2007.




image020.jpgMr. Marmalade

Mr. Marmalade is the unofficial group mascot. He appeared approximately two years ago and hasn’t left since. His days consist mostly of waiting to be fed (8AM and 6PM sharp), sleeping in bushes, and catching rabbits and mice. He also is the group anti-stressing agent, allowing them to do something other than research. His area of research is on understanding the impact of cats on local rabbit and mice populations, preliminary results indicate a dramatic reduction in both rabbit and mice populations.




Post-Graduate Students


Bethany Warren (Ph.D completed 6/2008, currently at Pacific Air & Environment in Brisbane, Australia)

Ph.D Dissertation Title “Influence of Environmental Parameters on Secondary Organic Aerosol Formation”



Aniket Sawant (Ph.D. completed 6/2006, currently at Johnson-Matthey)

Ph.D. Dissertation Title “Analyses and Impacts of Selected Emission Sources”

M.S. Dissertation Title “Characterization of Indoor and Outdoor Gas- and Particle-Phase Compounds in Western  

                                  Riverside County, California”


Chen Song (Ph.D. completed 6/2006, currently at Pacific Northwest National Laboratory)

Ph.D. Dissertation Title “Secondary Organic Aerosol Formation from Aromatic Hydrocarbons”


Sandip Shah (Ph.D. completed 6/2005, currently at Ford Motor Co. Research Laboratories)

Ph.D. Dissertation Title “A Study of the Physical and Chemical Properties of Exhaust Emissions

       from Heavy-Duty Diesel Engines”


Abhilash Nigam (anticipated Ph.D. defense date 10/2007)



Undergraduate Students (in alphabetical order)


Julien Araiza

Kevin Nguyen

Richard Rojas

Dylan Switzer