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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Teco: Carbon Monoxide Consumption By Forest And Agroecosystem Soils, Gary M. King Dec 2001

Teco: Carbon Monoxide Consumption By Forest And Agroecosystem Soils, Gary M. King

University of Maine Office of Research Administration: Grant Reports

Carbon monoxide is a more dynamic component of the atmosphere than methane, occurring at a lower concentration but substantially higher flux. CO and hydroxyl radical interact rapidly, affecting a number of atmospheric parameters: the oxidative state of the troposphere; the fate and residence times of methane, non-methane organics and inorganics; tropospheric ozone; and the extent of thermal forcing. Soils consume atmospheric CO, accounting for 10-25% of the global carbon budget, depending on the source estimate. Some of the controls of soil CO uptake and production have been described generally, but much remains unknown. Details of CO uptake in agroecosystems are …


Collaborative Research: Chemical Equilibria Involving Iron And Hydrogen In Metapelites From Western Maine, Charles V. Guidotti Oct 2001

Collaborative Research: Chemical Equilibria Involving Iron And Hydrogen In Metapelites From Western Maine, Charles V. Guidotti

University of Maine Office of Research Administration: Grant Reports

The primary goal of this research is to evaluate the chemical equilibria involving ferrous and ferric iron and hydrogen in metapelitic rocks from western Maine and related rocks at Black Mountain, New Hampshire. We will study samples from graphite, magnetite, and hematite-bearing rocks at three different metamorphic grades: garnet, lower sillimanite, and staurolite zone. This will permit the determination of:

(1) in situ partition coefficients for Fe3+ and Fe2+ among all the Fe-bearing phases and for H among hydrous phases;
(2) the temperature and fO2 dependence of Fe3+/Fetotal and effects of Fe3+ substitution on other cation substitutions plus their implications …


The Origin Of A Polar Ice Sheet In East Antarctica, George H. Denton Oct 2001

The Origin Of A Polar Ice Sheet In East Antarctica, George H. Denton

University of Maine Office of Research Administration: Grant Reports

This award supports a study to determine the sequence and chronology of events that led to the development of the Antarctic ice sheet. A continental-scale ice sheet probably first developed in East Antarctica close to the Eocene-Oligocene boundary under temperate climatic conditions. The purpose of this project is to determine, from landscape analysis (with a numerical chronology), when (and why) these early temperate conditions gave way to a polar environment in Antarctica. From previous field work and recent photographic analysis, an extensive relict landscape (older than 17 million years) with landforms and erosional features characteristic of temperate glaciation has been …


Acquisition Of Ion Chromatographs And Related Glaciochemistry Equipment, Paul Andrew Mayewski Sep 2001

Acquisition Of Ion Chromatographs And Related Glaciochemistry Equipment, Paul Andrew Mayewski

University of Maine Office of Research Administration: Grant Reports

The goal of this project has been to upgrade the ice core processing and analytical equipment. This has been accomplished in three major areas: the design and construction of an ice core lathe, develpoment of a continuous melting system, and new ion chromatographs. The lathe is a unique ice core processing tool that operates similiar to a wood lathe. The lathe will reduce or eliminate the need for the cores to be hand scraped, the first cleaning step of core preparation.

Our continuous melting system is a modification of existing designs. Unlike other systems, we will collect discrete samples for …


Collaborative Research: Paleoclimate And Glaciological Recontructions In Central Asia, Karl J. Kreutz Sep 2001

Collaborative Research: Paleoclimate And Glaciological Recontructions In Central Asia, Karl J. Kreutz

University of Maine Office of Research Administration: Grant Reports

This project resulted in the collection of two intermediate-length (165 m) ice cores from the Inilchek Glacier, Central Tien Shan Mountains, Kyrgyzstan, during July/August 2000 with colleagues from UCSB, UNH, and the USGS. In addition, precipitation, fresh snow, surface snow, and aerosol samples were collected on the glacier and in the Inilchek Valley to assess atmospheric chemistry and deposition processes. The overall goal of the project (including a pending NSF/DOE proposal) is to develop high-resolution paleoclimatic records covering the last 1000-2000 years, which will be calibrated with meteorological data from the robust station network in the former Soviet Central Asian …


New And Export Productivity Regulation By Si And Fe In The Equatorial Pacific Ocean, Fei Chai Aug 2001

New And Export Productivity Regulation By Si And Fe In The Equatorial Pacific Ocean, Fei Chai

University of Maine Office of Research Administration: Grant Reports

To identify and quantify the principal processes that control the partitioning of carbon among oceanic reservoirs and between the ocean and atmosphere on focal and regional scales, with a view towards synthesis and prediction on a global scale, is a specific goal of the U.S. JGOFS Synthesis and Modeling Project. As a contribution towards achieving this goal, Drs. Barber, Peng, Chai and Dugdale will develop an ecosystem model for the equatorial Pacific Ocean, with a focus on how silicate and iron affect new and export productivity and the partitioning of carbon between the atmosphere, surface ocean and deep ocean. The …


Emersion Stress In Intertidal Seaweeds: Role Of Active Oxygen, Ian R. Davison Aug 2001

Emersion Stress In Intertidal Seaweeds: Role Of Active Oxygen, Ian R. Davison

University of Maine Office of Research Administration: Grant Reports

The study will examine stress-tolerance in two major groups of perennial intertidal macroalgae, the red and brown seaweeds. The research will test the hypothesis that active oxygen is involved in emersion stress of intertidal seaweeds. Damage due to active oxygen will be determined in stress-tolerant and stress- susceptible species exposed to emersion stress by measuring the peroxidation of membrane lipids. Plants will be grown in laboratory culture under conditions that increase their ability to withstand emersion stress. If the research hypothesis is correct, increases in stress tolerance should be associated with increased levels of antioxidants and/or protective enzymes. The proposed …


School Of Marine Sciences / Darling Marine Center, Kevin J. Eckelbarger Jul 2001

School Of Marine Sciences / Darling Marine Center, Kevin J. Eckelbarger

University of Maine Office of Research Administration: Grant Reports

Over the last six years, the University of Maine has made an unprecedented investment in its marine laboratory, the Darling Marine Center to benefit both University faculty and visiting researchers and their students. Facility improvements include many new laboratory and offices spaces, more research instrumentation, and basic support facilities such as a dining hall and new classrooms. The inauguration of a Visiting Investigation Program in 1991, the expansion of educational offerings, and the growth of a large undergraduate internship program, have resulted in a population explosion that shows no sign of abating. To set priorities for improvements, the University has …


A Theory Of Global Climate Change On Millennial Time Scales, Kirk A. Maasch Jul 2001

A Theory Of Global Climate Change On Millennial Time Scales, Kirk A. Maasch

University of Maine Office of Research Administration: Grant Reports

A Theory of Global Climate Change on Millennial Time Scales In the northern hemisphere, large and rapid shifts in environmental conditions have occurred repeatedly over the last glacial- interglacial cycle. Indications are that climate change occurs on two characteristic time scales, roughly 1 - 3,000 years and 5 - 10,000 years. Evidence for millennial-scale climate variability has been found in ice cores drilled through the Greenland ice sheet, sediment cores from the North Atlantic Ocean, pollen records from both North America and Europe, and glacial deposits in North America. Paleoclimate records from the southern hemisphere also show climatic variability on …


Hierarchical Modeling For Integrated Environmental Assessments, Raymond O'Connor, Deidre Mageean Jun 2001

Hierarchical Modeling For Integrated Environmental Assessments, Raymond O'Connor, Deidre Mageean

University of Maine Office of Research Administration: Grant Reports

The distribution of biotic resources over large spatial extents is often a function of climate, of land-use, and of the demographics of the human population but these different classes of independent variables have different spatial scales for their action. One approach to the integration of these effects across scales is to use hierarchical models that incorporate contingencies and constraints in effects. This project seeks to develop such a modeling paradigm by use of classification and regression trees (CART). The hexagonal grid of the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program is used as the spatial grid, with about …


Computer Simulations Of Confined Systems, Jayendran C. Rasaiah May 2001

Computer Simulations Of Confined Systems, Jayendran C. Rasaiah

University of Maine Office of Research Administration: Grant Reports

Jayendran Rasaiah of the University of Maine is supported by an award from the Theoretical and Computational Chemistry program with partial funding provided by the Experimental Program to Stimulate Competitive Research for the development of computational methods to simulate water and other solvents in confined systems, such as carbon nanotubes and the interior of proteins. Other systems which are being studied include capillary evaporation of water between hydrophobic plates, water near surfaces and water between charged membranes. The development of better water potentials for a variety of applications is a major goal of the research. Rasaiah is also developing efficient …