Results 31 to 40 of about 255,270 (305)

Exploring the Origins of Deuterium Enrichments in Solar Nebular Organics [PDF]

, 2016
Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies have generally higher D/H ratios and show greater D/H variation when compared to
Alexander, Conel M. O'D., Bergin, Edwin A., Cleeves, L. Ilsedore, Du, Fujun, Graninger, Dawn, Harries, Tim J., Öberg, Karin I.   +6 more
core   +2 more sources

The provenance of selected heavy metals in soils near power plant of Hamedan: A pedological approach

مجله آب و خاک, 2014
To determine the origin of heavy metals, the effects of parent materials, soil genesis, and human activities on the content and distribution of selected metals in soils near Mofateh Martyr powerhouse, Hamedan, were assessed.
Sh. Nosratipoor, M. Nael, M. Sheklabadi, A.A. Sepahi Garo   +3 more
doaj   +1 more source

Deuterated Ammonia in Galactic Protostellar Cores [PDF]

, 2001
We report on a survey of \nh2d towards protostellar cores in low-mass star formation and quiescent regions in the Galaxy. Twenty-three out of thirty-two observed sources have significant ($\gsim 5\sigma$) \nh2d emission.
Alwyn Wootten, Bachiller R., Bachiller R., Batrla W., Bester M., Cesaroni R., de Boisanger C., Duley W. W., Jacq T., Krugel E., Lefloch B., Leger A., Marquette J. B., Martin-Pintado J., Martin-Pintado J., Mauersberger R., Millar T. J., Olberg M., Roberts H., Ronak Y. Shah, Scott G. B. I., Tielens A. G. G. M., Tine S., Walmsley C. M., Wootten A., Zeng Q.   +25 more
core   +2 more sources

Chemical Fractionation of Trace Elements in Arctic PM₁₀ Samples

Atmosphere, 2021
In this study, the information potential of a two-step sequential extraction procedure was evaluated. For this purpose, first of all the elemental composition of Arctic PM10 samples collected in Ny-Ålesund (Svalbard Islands) from 28 February 2015 to 21 ...
Eleonora Conca, Mery Malandrino, Agnese Giacomino, Paolo Inaudi, Annapaola Giordano, Francisco Ardini, Rita Traversi, Ornella Abollino   +7 more
doaj   +1 more source

Gas phase production of NHD2 in L134N [PDF]

, 2001
We show analytically that large abundances of NH2D and NHD2 can be produced by gas phase chemistry in the interiors of cold dense clouds. The calculated fractionation ratios are in good agreement with the values that have been previously determined in ...
Adams N. G., Brown P. D., Brown P. D., Ceccarelli C., Gerin M., Guelin M., Larsson M., Le Bourlot J., Le Bourlot J., Loinard L., Marquette J. B., Millar T. J., Olberg M., Opendak M., Roberts H., Rodgers S. D., Roueff E., S. B. Charnley, S. D. Rodgers, Sidhu K. S., Tielens A. G. G. M., Tine S., Ungerechts H., Vikor L.   +23 more
core   +2 more sources

How well does ramped thermal oxidation quantify the age distribution of soil carbon? Assessing thermal stability of physically and chemically fractionated soil organic matter [PDF]

Biogeosciences, 2023
Carbon (C) in soils persists on a range of timescales depending on physical, chemical, and biological processes that interact with soil organic matter (SOM) and affect its rate of decomposition.
S. W. Stoner, S. W. Stoner, M. Schrumpf, A. Hoyt, C. A. Sierra, C. A. Sierra, S. Doetterl, V. Galy, S. Trumbore   +8 more
doaj   +1 more source

Seasonal variations in the concentration and solubility of elements in atmospheric particulate matter: a case study in Northern Italy

E3S Web of Conferences, 2013
Atmospheric particulate matter is characterized by a variety of chemical components, generally produced by different sources. Chemical fractionation of elements, namely the determination of their extractable and residual fractions, may reliably increase ...
Canepari S., Astolfi M. L., Marcovecchio F., Maretto M., Perrino C.   +4 more
doaj   +1 more source

A biomimetic peptide has no effect on the isotopic fractionation during in vitro silica precipitation

Scientific Reports, 2021
The stable isotopic composition of diatom silica is used as a proxy for nutrient utilisation in natural waters. This approach provides essential insight into the current and historic links between biological production, carbon cycling and climate ...
Lucie Cassarino, Paul Curnow, Katharine R. Hendry   +2 more
doaj   +1 more source

Phosphorus concentrations in sediments from the equatorial Amazon estuary, Furo of Muriá, Pará State, Brazil

Acta Scientiarum: Technology, 2022
We characterized the spatial and seasonal distributions of different phosphorus fractions in surface sediments from the Furo of Muriá estuary by chemical fractionation.
Ana Carolina Santa Rosa de Sousa, Rosa Maria da Luz Mendes, Francianne Vieira Mourão, Maamar El Robrini, José Almir Rodrigues Pereira, Pedro Henrique Campos Sousa, Maria Lourdes de Souza Santos   +6 more
doaj   +1 more source

Chemical fractionation and abundances in coronal plasma [PDF]

Advances in Space Research, 2003
10 pages, 4 figures, to appear in Adv.Sp ...
openaire   +2 more sources