Results 271 to 280 of about 248,597 (344)

Model of Nitrogen Source Allocations and Transformations Using Stable Nitrogen Isotopes

World Environmental and Water Resources Congress 2013, 2013
Stream restoration for water quality and nutrient management relies on effective assessment methods that measure the before-and-after improvement of water quality, or lack thereof, from implementation. We present a water quality and nutrient modeling tool for potential use in such applications.
W. I. Ford, J. F. Fox
openaire   +1 more source

INCORPORATING NITROGEN STABLE ISOTOPES INTO ATMOSPHERIC CHEMISTRY MODELS

2021
The nitrogen stable isotope composition (δ15N) of nitrogen oxides (NOx) may be an effective tool to evaluate the accuracy of the NOx emission inventories, which are based on different assumptions. In order to approach this goal, the understanding of (1) the δ15N(NOx) values of the major emission sources, (2) how atmospheric processes, such as mixing ...
openaire   +1 more source

Tracing nitrogen cycling in mining waters using stable nitrogen isotope analysis

Applied Geochemistry, 2017
Abstract We show how we used stable nitrogen and oxygen isotopes in ammonium and nitrate to identify and quantify nitrogen transformation and nitrogen sources at the LKAB mining site in northern Sweden. Stable nitrogen isotope analysis worked as an excellent tool for tracing nitrogen cycling in rapidly moving process waters.
Lino Nilsson, Anders Widerlund
openaire   +1 more source

USING STABLE ISOTOPES TO MONITOR ANTHROPOGENIC NITROGEN INPUTS TO ESTUARIES

Ecological Applications, 2008
Use of stable nitrogen isotope ratios is one method that has been proposed to indicate anthropogenic nutrient enrichment in estuarine systems. However, the role of stable isotopes as a tool in long-term ecosystem monitoring has not been fully developed.
Bannon, Rebecca O., Roman, Charles T.
openaire   +3 more sources

Stable carbon and nitrogen isotope analysis of avian uric acid

Rapid Communications in Mass Spectrometry, 2008
Abstract We report results obtained using a new technique developed to measure the stable‐isotope composition of uric acid isolated from bird excreta (guano). Results from a diet‐switch feeding trial using zebra finches suggest that the δ 13 C of uric ...
Bird, Michael I., Tait, Elaine, Wurster, Christopher M., Furness, Robert W.   +3 more
openaire   +3 more sources

Primary Consumer Stable Nitrogen Isotopes as Indicators of Nutrient Source

Environmental Science & Technology, 2005
Non-point source loading of nitrogen and phosphorus is a primary cause of eutrophication of inland waters, although the diffuse and variable nature of nutrient inputs makes it difficult to trace and identify nutrient pathways. Stable nitrogen isotope values (delta15N) in aquatic biota are thought to reflect anthropogenic nutrient inputs, and they may ...
Zanden, M. J. Vander, Vadeboncoeur, Yvonne, Diebel, Matthew W., Jeppesen, Erik   +3 more
openaire   +4 more sources

Identifying migratorySalmo trutta using carbon and nitrogen stable isotope ratios

Rapid Communications in Mass Spectrometry, 2000
Many Salmo trutta populations consist of non-anadromous (freshwater-resident) brown trout and anadromous (sea-run migratory) sea trout. Although adult brown trout and sea trout can usually be identified using differences in size and body colouration, it is not possible to easily identify eggs/alevins as the progeny of brown trout or sea trout.
I D, McCarthy, S, Waldron
openaire   +2 more sources

Assessment of stable nitrogen isotopes in fingerprinting surface water inorganic nitrogen sources

Water, Air, and Soil Pollution, 1989
In many coastal areas of Louisiana, surface water quality is deteriorating rapidly due to elevated nutrient input from agricultural, domestic and industrial sources. This study investigates the potential use of natural abundance variations in 15N/14N ratios for identification and tracing surface water inorganic N sources.
C. W. Lindau, R. D. Delaune, W. H. Patrick, E. N. Lambremont   +3 more
openaire   +1 more source

Improved Stable Nitrogen Isotope Ratio Measurements of Natural Gases

Analytical Chemistry, 1994
A system has been developed at BGR for rapid and precise nitrogen isotopic ratio measurements on natural gases in northern Germany using a gas chromatograph coupled with an isotope ratio mass spectrometer (GC/IRMS). The main advantage of the GC/IRMS system relative to conventional techniques is the analysis of gases with varying nitrogen concentrations
Eberhard. Sohns, Peter. Gerling, Eckhard. Faber   +2 more
openaire   +1 more source

Mapping Stable Nitrogen Isotopes Using Hyperspectral Imagery

2014
Virginia Tech.
Correll, Katie, Strahm, Brian D., Thomas, Valerie A.   +2 more
openaire   +1 more source