Search Results - "Siefert, Ronald L"

Global distribution of atmospheric phosphorus sources, concentrations and deposition rates, and anthropogenic impacts by Mahowald, Natalie, Jickells, Timothy D., Baker, Alex R., Artaxo, Paulo, Benitez-Nelson, Claudia R., Bergametti, Gilles, Bond, Tami C., Chen, Ying, Cohen, David D., Herut, Barak, Kubilay, Nilgun, Losno, Remi, Luo, Chao, Maenhaut, Willy, McGee, Kenneth A., Okin, Gregory S., Siefert, Ronald L., Tsukuda, Seigen

“…A worldwide compilation of atmospheric total phosphorus (TP) and phosphate (PO4) concentration and deposition flux observations are combined with transport…”
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Atmospheric iron deposition: global distribution, variability, and human perturbations by Mahowald, Natalie M, Engelstaedter, Sebastian, Luo, Chao, Sealy, Andrea, Artaxo, Paulo, Benitez-Nelson, Claudia, Bonnet, Sophie, Chen, Ying, Chuang, Patrick Y, Cohen, David D, Dulac, Francois, Herut, Barak, Johansen, Anne M, Kubilay, Nilgun, Losno, Remi, Maenhaut, Willy, Paytan, Adina, Prospero, Joseph M, Shank, Lindsey M, Siefert, Ronald L

“…Atmospheric inputs of iron to the open ocean are hypothesized to modulate ocean biogeochemistry. This review presents an integration of available observations…”
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Micelle formation, structures, and metrology of functional metal nanoparticle compositions by Middleton, James M., Siefert, Ronald L., James, Markie'Sha H., Schrand, Amanda M., Kolel-Veetil, Manoj K.

“…Micelles are self-assembled aggregates that are formed, in many different structures, from surfactants and have a wide range of applications. The critical…”
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Chemical composition of aerosols collected over the tropical North Atlantic Ocean by Johansen, Anne M., Siefert, Ronald L., Hoffmann, Michael R.

“…Ambient aerosol samples were collected over the tropical northern Atlantic Ocean during the month of April 1996 onboard the R/V Seward Johnson. Dichotomous…”
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Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Labile-Fe(II) and other trace metals by Siefert, Ronald L., Johansen, Anne M., Hoffmann, Michael R.

“…Atmospheric deposition of iron (Fe) to certain regions of the oceans is an important nutrient source of Fe to the biota, and the ability of the biota to uptake…”
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Extraction of Perchlorate Using Porous Organosilicate Materials by Johnson, Brandy J, Leska, Iwona A, Melde, Brian J, Siefert, Ronald L, Malanoski, Anthony P, Moore, Martin H, Taft, Jenna R, Deschamps, Jeffrey R

“…Sorbent materials were developed utilizing two morphological structures, comprising either hexagonally packed pores (HX) or a disordered pore arrangement (CF)…”
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Electrochemical Detection with Preconcentration: Nitroenergetic Contaminants by Johnson, Brandy J, Nasir, Mansoor, Siefert, Ronald L, Leska, Iwona A, Erickson, Jeffrey S, Charles, Paul T, Melde, Brian J, Taft, Jenna R

“…This effort evaluated the potential of two prototype devices for enhanced electrochemical detection of 2,4,6-trinitrotoluene (TNT) and dinitrotoluene (DNT)…”
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Seasonal and spatial distributions and dry deposition fluxes of atmospheric total and labile iron over the tropical and subtropical North Atlantic Ocean by Chen, Ying, Siefert, Ronald L.

“…The tropical and subtropical region of the North Atlantic Ocean is under the influence of mineral dust plumes transported from North Africa, resulting in high…”
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Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Anions and cations by Johansen, Anne M., Siefert, Ronald L., Hoffmann, Michael R.

“…Ambient aerosol samples were collected over the northern Indian Ocean during two 1 month‐long research cruises (German R/V Meteor) that took place during the…”
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Kinetic and Equilibrium Constants of Phytic Acid and Ferric and Ferrous Phytate Derived from Nuclear Magnetic Resonance Spectroscopy by Heighton, Lynne, Schmidt, Walter F, Siefert, Ronald L

“…Inositol phosphates are metabolically derived organic phosphates (P) that increasingly appear to be an important sink and source of P in the environment. Salts…”
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Luxury uptake of aerosol iron by Trichodesmium in the western tropical North Atlantic by Chen, Ying, Tovar-Sanchez, Antonio, Siefert, Ronald L., Sañudo-Wilhelmy, Sergio A., Zhuang, Guoshun

“…Dust transported from North Africa carries micronutrient iron (Fe) to the western tropical North Atlantic (WTNA) which may significantly influence the…”
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Measurements of Trace Metal (Fe, Cu, Mn, Cr) Oxidation States in Fog and Stratus Clouds by Siefert, Ronald L., Johansen, Anne M., Hoffmann, Michael R., Pehkonen, Simo O.

“…The oxidation state of four transition metals (Fe, Mn, Cu, and Cr) in cloudwater has been investigated during several cloud events at Whiteface Mountain (NY),…”
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Infrared spectroscopic study of the deliquescence and efflorescence of ammonium sulfate aerosol as a function of temperature by Onasch, Timothy B., Siefert, Ronald L., Brooks, Sarah D., Prenni, Anthony J., Murray, Benjamin, Wilson, Margaret A., Tolbert, Margaret A.

“…The deliquescence and efflorescence phase transitions of ammonium sulfate aerosols have been studied as a function of relative humidity (RH) over the…”
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Determination of ammonia emission rates from a tunnel ventilated chicken house using passive samplers and a Gaussian dispersion model by Siefert, Ronald L., Scudlark, Joseph R.

“…Atmospheric deposition can provide a significant fraction of the nitrogen loading to coastal waters. The Delmarva Peninsula, on the eastern shore of the…”
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Characterization of Atmospheric Ammonia Emissions from a Commercial Chicken House on the Delmarva Peninsula by Siefert, Ronald L, Scudlark, Joseph R, Potter, Amelia G, Simonsen, Kirsten A, Savidge, Karen B

“…A three-dimensional sampling grid using passive collectors was used to characterize the downwind gas-phase ammonia plumes originating from a commercial chicken…”
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Composition-dependent freezing nucleation rates for HNO3/H2O aerosols resembling gravity-wave-perturbed stratospheric particles by Prenni, Anthony J., Onasch, Timothy B., Tisdale, Robert T., Siefert, Ronald L., Tolbert, Margaret A.

“…Laboratory measurements are presented for the freezing kinetics of H2O/HNO3 aerosols over the temperature range of 188–204 K. For 2:1 H2O:HNO3 aerosols…”
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Photoreduction of Iron Oxyhydroxides and the Photooxidation of Halogenated Acetic Acids by Pehkonen, Simo O, Siefert, Ronald L, Hoffmann, Michael R

“…A study examined the kinetics and mechanisms of the photolytic reduction of iron oxides by haloacetic acids, which are produced in the troposphere by HCFC…”
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Luxury uptake of aerosol iron by Trichodesmium in the western tropical North Atlantic: UPTAKE OF AEROSOL IRON BY TRICHODESMIUM by Chen, Ying, Tovar-Sanchez, Antonio, Siefert, Ronald L., Sañudo-Wilhelmy, Sergio A., Zhuang, Guoshun

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Seasonal and spatial distributions and dry deposition fluxes of atmospheric total and labile iron over the tropical and subtropical North Atlantic Ocean by YING CHEN, SIEFERT, Ronald L

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An extensive bloom of the N₂-fixing cyanobacterium Trichodesmium erythraeum in the central Arabian Sea by Capone, Douglas G., Subramaniam, Ajit, Montoya, Joseph P., Voss, Maren, Humborg, Christoph, Johansen, Anne M., Siefert, Ronald L., Carpenter, Edward J.

“…We encountered an extensive surface bloom of the N₂ fixing cyanobacterium Trichodesmium erythraeum in the central basin of the Arabian Sea during the spring…”
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