نتایج جستجو برای: 11 geochemical tracers including oc organic carbon

تعداد نتایج: 1735166  

2015
H. Cui P. Mao Y. Zhao C. P. Nielsen J. Zhang

China is experiencing severe carbonaceous aerosol pollution driven mainly by large emissions resulting from intensive use of solid fuels. To gain a better understanding of the levels and trends of carbonaceous aerosol emissions and the resulting ambient concentrations at the national scale, we update an emission inventory of anthropogenic organic carbon (OC) and elemental carbon (EC) and employ...

2014
J. Pavlovic J. S. Kinsey M. D. Hays

Thermal–optical analysis (TOA) is a widely used technique that fractionates carbonaceous aerosol particles into organic and elemental carbon (OC and EC), or carbonate. Thermal sub-fractions of evolved OC and EC are also used for source identification and apportionment; thus, oven temperature accuracy during TOA analysis is essential. Evidence now indicates that the “actual” sample (filter) temp...

2014
M. Abdollahi H. R. Karbalaei-Heidari

Using enrichment procedures, 45 organic solvent-tolerant lipase producer bacterial strains were screened from areas contaminated by oil and organic solvents. Among the strains, 15 isolates exhibited extreme stability toward organic solvents and high lipolytic activity. The NEB-1 isolate which was later identified as Pseudomonas sp. strain NEB-1 by biochemical tests and 16S rDNA gene sequence an...

2011
J. A. O’Donnell J. W. Harden A. D. McGuire V. E. Romanovsky

In the boreal region, soil organic carbon (OC) dynamics are strongly governed by the interaction between wildfire and permafrost. Using a combination of field measurements, numerical modeling of soil thermal dynamics, and mass-balance modeling of OC dynamics, we tested the sensitivity of soil OC storage to a suite of individual climate factors (air temperature, soil moisture, and snow depth) an...

Journal: :Clinical positron imaging : official journal of the Institute for Clinical P.E.T 1998
R M Quinlivan R O Robinson M N Maisey

Types of PET study There are three types of cardiac PET study: regional blood flow (which can be measured at rest and during pharmacological induced stress), substrate metabolism, and chemical recognition (including receptors and enzymes). Currently, the main clinical application of PET is in the diagnosis of coronary artery disease, in terms of the diVerentiation between infarcted and “stunned...

2016
Marttiina V. Rantala Tomi P. Luoto Liisa Nevalainen

Widespread ecological reorganizations and increases in organic carbon (OC) in lakes across the Northern Hemisphere have raised concerns about the impact of the ongoing climate warming on aquatic ecosystems and carbon cycling. We employed diverse biogeochemical techniques on a high-resolution sediment record from a subarctic lake in northern Finland (70°N) to examine the direction, magnitude and...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2012
Kumiko Tsuda Akihiro Takata Hidekado Shirai Katsutoshi Kozaki Nobuhide Fujitake

Aquatic humic substances (AHSs) are major constituents of dissolved organic matter (DOM) in freshwater, where they perform a number of important ecological and geochemical functions, yet no method exists for quantifying all AHSs. We have developed a method for the quantitative analysis of AHSs based on their carbon concentration. Our approach includes: (1) the development of techniques for cl...

Journal: :Ecology 2014
Patrick T Kelly Christopher T Solomon Brian C Weidel Stuart E Jones

Inputs of terrestrial organic carbon (t-OC) into lakes are often considered a resource subsidy for aquatic consumer production. Although there is evidence that terrestrial carbon can be incorporated into the tissues of aquatic consumers, its ability to enhance consumer production has been debated. Our research aims to evaluate the net effect of t-OC input on zooplankton. We used a survey of zoo...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Thomas S Bianchi

One of the major conundrums in oceanography for the past 20 y has been that, although the total flux of dissolved organic carbon (OC; DOC) discharged annually to the global ocean can account for the turnover time of all oceanic DOC (ca. 4,000-6,000 y), chemical biomarker and stable isotopic data indicate that there is very little terrestrially derived OC (TerrOC) in the global ocean. Similarly,...

Khadijeh Mahdavi, Maedeh Yousefian Mohammad Mahdavi, Reza Tamartash

Livestock grazing is one of the most important kinds of land usage that has a high potential to decrease or increase carbon storage in rangeland ecosystem. This research was investigated the effects of enclosure on soil carbon storage in a rangeland with dominant plants of Artemisia aucheri. Hence, two rangelands of enclosure (Shahtappeh-Chah Mahmood) and no enclosure (Chiro) were chosen in Sem...

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