Stream drying drives microbial ammonia oxidation and first-flush nitrate export

Funded by Spanish National Research Council (CSIC). Grant Number: CGL2012-32747 MINECO. Grant Numbers: CGL2012-32747, CGL2011-30590-CO2-02 EU Commission. Grant Number: 244121 FP7

Short-term impact of soybean management on ammonia oxidizers in a Brazilian savanna under restoration as revealed by coupling different techniques

Acknowledgments The authors are very grateful to Mr. Fabiano Bielefeld Nardotto, owner of the Tabapuã dos Pireneus farm, for allowing our free movement around the farm and collection of soil samples, as well as providing information about soybean cultivation. The authors also thank Dr. Plínio de Camargo, who performed the isotopic analysis in the CENA laboratory at the University of São Paulo (USP). This work was supported by grants from the National Council of Technological and Scientific Development (CNPq), Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES), and Foundation for Research Support of Distrito Federal (FAP-DF).

Seawater carbonate chemistry and impacts of calcium and carbonate ion concentration on Mg and Sr incorporation in cultured benthic foraminifera (Ammonia tepida and Heterostegina depressa), 2011

Laboratory culture experiments were conducted to determine effects of seawater carbonate ion concentration ([CO32-]), and thereby calcite saturation state, on Mg and Sr incorporation into calcite of two species of shallow-water benthic foraminifera: Ammonia tepida and Heterostegina depressa. Impact on Mg and Sr incorporation by increased seawater [CO32-] and thereby higher calcite saturation state, is absent in either species. Comparison to results from a similar culturing experiment, in which calcite saturation state was varied as a function of [Ca2+], reveals that saturation state affects incorporation of Mg and Sr through calcium- rather than carbonate availability. The similarity in response by both species is surprising since the average Mg/Ca ratio is ~ 70 times higher in H. depressa than in A. tepida. Furthermore, these results suggest that the ions involved in biomineralization (i.e. Ca2+ and DIC) are processed by separate cellular transport mechanisms. The similar response of Mg and Sr incorporation in this study suggests that only differences in the Ca2+ transport mechanism affect divalent cation partitioning.

Seawater carbonate chemistry and benthic foraminifera Ammonia sp. mass, size, and growth rate during experiments, 2013

About 30% of the anthropogenically released CO2 is taken up by the oceans; such uptake causes surface ocean pH to decrease and is commonly referred to as ocean acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50 % of biogenic calcium carbonate in the open oceans. We have compiled the state of the art literature on OA effects on foraminifera, because the majority of OA research on this group was published within the last three years. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process-based understanding of OA effects on foraminifera. We cultured the benthic foraminifer Ammonia sp. under a range of carbonate chemistry manipulation treatments to identify the parameter of the carbonate system causing the observed effects. This parameter identification is the first step towards a process-based understanding. We argue that CO3 is the parameter affecting foraminiferal size-normalized weights (SNWs) and growth rates. Based on the presented data, we can confirm the strong potential of Ammonia sp. foraminiferal SNW as a CO3 proxy.

Seawater carbonate chemistry and processes during experiments with benthic foraminifera Ammonia tepida

Evidence of increasing concentrations of dissolved carbon dioxide, especially in the surface ocean and its associated impacts on calcifying organisms, is accumulating. Among these organisms, benthic and planktonic foraminifera are responsible for a large amount of the globally precipitated calcium carbonate. Hence, their response to an acidifying ocean may have important consequences for future inorganic carbon cycling. To assess the sensitivity of benthic foraminifera to changing carbon dioxide levels and subsequent alteration in seawater carbonate chemistry, we cultured specimens of the shallow water species Ammonia tepida at two concentrations of atmospheric CO2 (230 and 1900 ppmv) and two temperatures (10 °C and 15 °C). Shell weights and elemental compositions were determined. Impact of high and low pCO2 on elemental composition are compared with results of a previous experiment were specimens were grown under ambient conditions (380 ppvm, no shell weight measurements of specimen grown under ambient conditions are, however, available). Results indicate that shell weights decrease with decreasing [CO3], although calcification was observed even in the presence of calcium carbonate under-saturation, and also decrease with increasing temperature. Thus both warming and ocean acidification may act to decrease shell weights in the future. Changes in [CO3] or total dissolved inorganic carbon do not affect the Mg distribution coefficient. On the contrary, Sr incorporation is enhanced under increasing [CO3]. Implications of these results for the paleoceanographic application of foraminifera are discussed.

Mixing behaviour of side injection of air jets and gaseous fuel jets into the axial flow of tunnel kilns

Otto-von-Guericke-Universität Magdeburg, Fakultät für Verfahrens- und Systemtechnik, Dissertation, 2016

Production of Gaseous Radiotracers Ch3i and I2 Through Na123i Salt

The objective of the present work was to develop, separately, methodology for production of two gaseous tracers through the sodium iodide NaI marked with 123I. Found in the nature in form different, the iodine has been used in diverse works in the area of the industry and health. These two forms of the gaseous iodine, the methyl iodide, CH3I, and molecular iodine, I2, are very unstable and volatile in the ambient temperature and presents different problems in clean-up and monitoring systems. The syntheses were processed with sodium iodide (NaI) 1M aqueous solution marked with 123I. The production of gas I2 was realized with in chlorine acid (HCl) and sodium iodate salt (NaIO3) and the CH3I was used, the salt of NaI and the reagent (CH3)2SO4. The production of gases was initially realized through in unit in glass with an inert material and the purpose was to study the kinetic of reaction and to determine the efficiency of production. The two synthesis occurs in the reaction bottle and after of produced, the gas is stored in the collect bottle that contains a starch solution for fixed the I2, and in syntheses of CH3I contains a silver nitrate solution for your fixation. To determine the efficiency of production of gases, analytic tests were realized, where the consumption of iodide ions of the bottle of reaction are measured. The optimization of production of the each gaseous tracer was studied varying parameter as: concentration of iodide, concentration of acid and temperature. After, the syntheses of the radiotracers were realized in the compact unit, having been used as main reagent the salt radiated of sodium iodide, Na123I. The transportation of elementary iodine and methyl iodine was studied by a scintillation detector NaI (2 x 2)” positioned in the reaction bottle.

Evaluation of Gaseous Fluid Dispersion Through Packed Bed Using Radiotracers Technique

In this study, it was developed a methodology for the determination of the dispersion of a gaseous tracer in porous media using the radiotracer technique. In order to evaluate several porous media, a cylindrical filter was constructed in PVC and connected to a system with constant flow. Inside this unit silica crystals (16-20) mesh was used as porous media and CH3Br (Methyl Bromide) marked with 82Br was used as radiotracer. An instantaneous pulse of tracer was applied in the system entrance and registered by two NaI (3x3)” scintillation detectors located one before and the other after the filter. The curves produced by the radioactive cloud and recorded by the detector were analyzed statistically using the weighted moment method. The mathematical model one considered as great dispersion of tracer was used to evaluate the flow conditions inside the filter system. The results show us that the weight moment method associated with radiotracer techniques is useful to evaluated an industrial filter and allows to measure the residence time distribution, τ, and the axial dispersion, DAB, gas in a porous medium.

Production of Gaseous Tracer I2 from the Sodiumiodide Salt

Found in the nature in form different, the iodine has been used in diverse works in the area of the industry and health. The iodine is very unstable and volatile in the ambient temperature and the I2 is one of the diverse gaseous forms found. In this work was developed methodology for production of gaseous tracer from the sodium iodide (NaI) 0,1 M marked with 123I. The synthesis was processed with in chlorine acid (HCl) 1M and sodium iodate salt (NaIO3). The production of gas I2 initially was carried through in unit of glass with the inert material and the purpose was to study the kinetic of reaction. The synthesis occurs in the reaction bottle and the produced gas is stored in the collect bottle that contains a starch solution (5 g/100 mL water). To determine the efficiency of production of gas I2, analytic tests had been carried through, where the consumption of iodide ions of the bottle of reaction is measured. The optimization of production of the gaseous tracer was studied varying parameters as: concentration of iodide and iodate, concentration of acid and temperature. Then, the synthesis of the radiotracer was realized in the compact unit, being utilized as main reagent the salt radiated of sodium iodide, Na123I. The transportation of elementary iodine was studied by a scintillation detector NaI (2 x 2)” placed in the reaction bottle. To acquire the data, the detector use a set of electronic modules for the acquisition of signals generated.