Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City (open access)

Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City

This study was part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in Mexico City Metropolitan Area during spring 2006. The physical and chemical transformations of particles aged in the outflow from Mexico City were investigated for the transport event of 22 March 2006. A detailed chemical analysis of individual particles was performed using a combination of complementary microscopy and micro-spectroscopy techniques. The applied techniques included scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure spectroscopy (NEXAFS) and computer controlled scanning electron microscopy with an energy dispersive X-ray analyzer (CCSEM/EDX). As the aerosol plume evolves from the city center, the organic mass per particle increases and the fraction of carbon-carbon double bonds (associated with elemental carbon) decreases. Organic functional groups enhanced with particle age include: carboxylic acids, alkyl groups, and oxygen bonded alkyl groups. At the city center (T0) the most prevalent aerosol type contained inorganic species (composed of sulfur, nitrogen, oxygen, and potassium) coated with organic material. At the T1 and T2 sites, located northeast of T0 (~;;29 km and ~;;65 km, respectively), the fraction of homogenously mixed organic particles increased in both size and number. These observations illustrate the …
Date: September 16, 2009
Creator: Moffet, R. C.; Henn, T. R.; Tivanski, A. V.; Hopkins, R. J.; Desyaterik, Y.; Kilcoyne, A. L. D. et al.
System: The UNT Digital Library
Elemental compositions of Spanish and Spanish-colonial majolica ceramics and their use in the identification of provenience (open access)

Elemental compositions of Spanish and Spanish-colonial majolica ceramics and their use in the identification of provenience

Neutron activation analysis, x-ray diffraction, and petrographic analysis were used to obtain evidence of the origin of pottery and ceramic sherds found in the New World and related to the Spanish empire. (GHT)
Date: January 1, 1977
Creator: Olin, Jacqueline S.; Harbottle, Garman & Sayre, Edward V.
System: The UNT Digital Library
Phytochemial Society of North America 50th Anniversary Meeting (open access)

Phytochemial Society of North America 50th Anniversary Meeting

The Phytochemical Society of North America will have its 50th anniversary meeting from December 10 through 15th, 2011, on the big island of Hawaii. The society has a long tradition in the study of plant biochemistry, chemistry, natural products (whether for commodity chemicals, food and fiber sources, renewable energy, pharmaceuticals, nutraceuticals and other bioactive substances). The meeting, being a very special celebration, is anticipated to attract a very broad range of researchers drawn from worldwide locations. This is also reflected in the international composition of our organizing and scientific program committees. We are now finalizing speakers for the PSNA 50 conference which has a variety of scientific themes, including biofuels/bioengineering, transcriptome profiling, metabolism and metabolomics, and new characterization technologies/methodologies. A most important part of our PSNA 50 conference is to provide opportunities for graduate students and postdoctoral fellows to present their research findings and exchange ideas with scientific colleagues. In this regard, the bulk of the funding in support of this conference is anticipated to come from sponsorships (industry, foundations, and so forth) and registrations which are currently underway. It is essential, however, that we strongly encourage the participation of both young graduate students and postdoctoral fellows at our historic …
Date: May 1, 2012
Creator: Lewis, Norman G.
System: The UNT Digital Library
First Biomass Conference of the Americas: Energy, environment, agriculture, and industry. Proceedings, Volume 2 (open access)

First Biomass Conference of the Americas: Energy, environment, agriculture, and industry. Proceedings, Volume 2

This conference was designed to provide a national and international forum to support the development of a viable biomass industry. Although papers on research activities and technologies under development that address industry problems comprised part of this conference, an effort was made to focus on scale-up and demonstration projects, technology transfer to end users, and commercial applications of biomass and wastes. The conference was divided into these major subject areas: Resource Base, Power Production, Transportation Fuels, Chemicals and Products, Environmental Issues, Commercializing Biomass Projects, Biomass Energy System Studies, and Biomass in Latin America. The papers in this second volume cover Transportation Fuels, and Chemicals and Products. Transportation Fuels topics include: Biodiesel, Pyrolytic Liquids, Ethanol, Methanol and Ethers, and Commercialization. The Chemicals and Products section includes specific topics in: Research, Technology Transfer, and Commercial Systems. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.
Date: October 1, 1993
Creator: unknown
System: The UNT Digital Library