نتایج جستجو برای: 11 geochemical tracers including oc organic carbon

تعداد نتایج: 1735166  

2005
P. Fermo

Carbon analysis consists in the evaluation of the carbonaceous content of the aerosol (TC) but, more importantly, of its distribution between the two components EC (Elemental Carbon) and OC (Organic Carbon) that are characterized by different physical-chemical properties. In spite of the numerous studies focused on this topic, nowadays a universal methodology for the determination of the two co...

2017
K. R. Chandana Ravi Bhushan A. J. T. Jull

Multi-proxy approach for the reconstruction of paleo-redox conditions is attempted on a radiocarbon (14C) dated sediment core near the equatorial Indian Ocean. Based on the behavior and distribution of redox sensitive and productivity proxies, study demonstrates prevalence of anoxic bottom water conditions during LGM due to poorly ventilated bottom waters augmented by high surface productivity ...

Journal: :Journal of environmental monitoring : JEM 2012
Zhenchuan Niu Fuwang Zhang Xiangrui Kong Jinsheng Chen Liqian Yin Lingling Xu

To understand the influence of the urbanization process on the air quality in the urban neighbourhood area, the size distribution and seasonal variations of elemental and organic carbon in aerosols were studied at a coastal and suburban site in Xiamen City, China. A total of 87 samples were obtained during the one-year measurement campaign from June 2009 to May 2010. The results indicated that ...

2005
Jeomshik Hwang Ellen R. M. Druffel Tomoko Komada

[1] Surface sediments along a transect from an abyssal site in the northeastern Pacific (Station M, 34 500N, 123 000W) to a small mountainous river on the California coast (Santa Clara River) were studied to investigate the sources and cycling of organic matter on the continental margin. Sediment samples were separated into organic compound fractions (extractable lipids, amino acids (THAA), car...

2009
Rebecca B. Neumann Khandaker N. Ashfaque A. B. M. Badruzzaman M. Ashraf Ali Julie K. Shoemaker

The origin of dissolved arsenic in the Ganges Delta has puzzled researchers ever since the report of widespread arsenic poisoning two decades ago. Today, microbially mediated oxidation of organic carbon is thought to drive the geochemical transformations that release arsenic from sediments, but the source of the organic carbon that fuels these processes remains controversial. At a typical site ...

Journal: :Environmental science & technology 2008
Allison C Aiken Peter F Decarlo Jesse H Kroll Douglas R Worsnop J Alex Huffman Kenneth S Docherty Ingrid M Ulbrich Claudia Mohr Joel R Kimmel Donna Sueper Yele Sun Qi Zhang Achim Trimborn Megan Northway Paul J Ziemann Manjula R Canagaratna Timothy B Onasch M Rami Alfarra Andre S H Prevot Josef Dommen Jonathan Duplissy Axel Metzger Urs Baltensperger Jose L Jimenez

A recently developed method to rapidly quantify the elemental composition of bulk organic aerosols (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is improved and applied to ambient measurements. Atomic oxygen-to-carbon (O/C) ratios characterize the oxidation state of OA, and O/C from ambient urban OA ranges from 0.2 to 0.8 with a diurnal cycle that decreases ...

2012
William H. Robinson Laurence L. Sloss

Introduction Petroleum Generation and Migration from Source Rocks Organic Geochemical Analysis . . Sampling Techniques Sample Preparation Analytical Procedure Organic Carbon Content . . . Page Page 3 Benzene Extractable Organic 3 Matter 5 Activated Alumina Column 4 Chromatography 5 4 Results of Analyses 7 4 Comparison of Extracted Material to 5 Crude Oil 10

Journal: :Frontiers in Marine Science 2022

A new saltmarsh soil dataset comprising of geochemical and physical property data from 752 samples collected through a sampling program supported by citizen scientists has been brought together with existing to make the first national estimates surficial (top 10 cm) OC stock for Great British (GB) saltmarshes. To allow inclusion secondary in estimate bespoke organic matter carbon conversion GB ...

2017
A. E. Johnston P. R. Poulton K. Coleman A. J. Macdonald R. P. White

The sequestration in soil of organic carbon (SOC) derived from atmospheric carbon dioxide (CO2) by replacing arable crops with leys, has been measured over 70 years on a sandy loam soil. The experiment was designed initially to test the effect of leys on the yields of arable crops. A 3-year grazed grass with clover (grass + clover) ley in a 5-year rotation with arable crops increased percentage...

2005
R. O. Salonen

A series of 7-week sampling campaigns were conducted in urban background sites of six European cities as follows: Duisburg (autumn), Prague (winter), Amsterdam (winter), Helsinki (spring), Barcelona (spring) and Athens (summer). The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiologica...

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