&lt;title&gt;Calibration of dispersive Raman process analyzers&lt;/title&gt;

Tedesco, James M.; Davis, Kevin L.

doi:10.1117/12.341033

Cited by 20 publications

(17 citation statements)

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“…A neon source was u sed for wavelength calibrati on and a calibrat ed tungst en l amp was used for int ensi ty cali bration. The laser wavel ength was checked by l ooking at the po sition of the 801 Δcm -1 Ram an lin e of cyclohexane (Tedesco and Davi s, 1999). The wavelen gth calibratio n of t he sp ectrom eter can b e affected b y changes in t emper ature (DORISS experien ced a t emperat ure drop of ~7°C duri ng the deployment).…”

Section: Instrumentationmentioning

confidence: 99%

Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

2006

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A new d eep-sea l aser Ram an spectrom eter (DORISS -Deep Ocean Raman In Situ Spectromet er) is used to ob serv e the preferenti al dissoluti on of CO 2 into seawater from a 50%-50% CO 2 -N 2 gas mi xture in a set of experimen ts that test a proposed met hod of CO 2 sequestrati on i n the deep ocean. In a fir st set of experiments performed at 300 m depth, an open-bott omed 1000 cm 3 cube was used to contai n the gas mixture; and in a second set of experiment s a 2.5 cm 3 funnel was used t o hold a bubbl e of t he gas mixtur e in front of the sampli ng optic. By ob servi ng th e ch anging ratios of the CO 2 and N 2 Raman bands we were abl e to determi ne the g as flux and the mass tran sfer co efficient at 300 m depth and com pare th em to t heoreti cal calcul ations for air-sea gas ex change. Although each exp eriment had a differ ent config uration, comparable result s were obt ained. As expected, th e ratio of CO 2 to N 2 drops off at an expon ential rate as CO 2 i s preferen tially di ssolved i n seawater. In fitting th e dat a with theoretical gas flux calculation s, the boundary layer thick ness was det ermined t o be ~42 µm for the gas cube, and ~165 µm for the gas funnel reflecting different boundary l ayer t urbulence. The mass tran sfer co efficient s for CO 2 are k L = 2.82 x 10 -5 m/s for the gas cube experiment, and k L = 7.98 x 10 -6 m/s for the gas funnel experim ent.

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Section: Instrumentationmentioning

confidence: 99%

Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

2006

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“…This is due to tolerances in the camera mounting holes. The calibration kit supplied by Kaiser Optical includes a neon source for wavelength calibration, a tungsten source for intensity calibration, and a cyclohexane standard to verify the laser wavelength (Tedesco and Davis, 1999).…”

Section: Calibrationmentioning

confidence: 99%

Final Progress Report: Direct Experiments on the Ocean Disposal of Fossil Fuel CO2.

Barry¹,

Brewer²

2004

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IntroductionFrom 2001 to early 2004, we performed field and laboratory experiments, and developed technology to investigate the feasibility and biological consequences of direct ocean CO2 injection as a sequestration strategy to mitigate rising levels of CO2 in the atmosphere. These activities were performed using support from the Monterey Bay Aquarium Research Institute (MBARI) and DoE, through the combined efforts of MBARI ships, ROVs, and science, engineering and operations personnel. DoE support included funding from NETL (Award DE-FC26-00NT40929 :Feasibility of large-scale ocean CO2 sequestration -Drs. Brewer and Barry) and DoE Office of Science Award DE-FG03-01DF63065 (Direct Experiments on the Ocean Disposal of Fossil Fuel CO 2 -Drs. Barry and Brewer). Activities supported by the Office of Science award were intertwined closely with those funded by NETL and MBARI, but were associated most closely studies by postdoctoral fellows. The major results of activities supported by the NETL award are listed in the attached technical progress report which includes several scholarly publications related to this research. Field ExperimentsSeveral deep-sea field experiments were performed off the California coast during 2001 to 2003. Each of these experiments involved a logistically complicated process of pressurizing and transporting small quantities (~20 to 150 l) of liquid CO2 to the seafloor using the ROV Tiburon, launched from the R/V Western Flyer, operated by MBARI. Five of these small-scale CO2 release experiments were used to evaluate the response of deep-sea organisms to changes in seawater chemistry caused by the addition of CO2 to the ocean. During each experiment, small pools of liquid CO2 were created on the seafloor, after which the CO2 would dissolve slowly into seawater, carrying a CO2-rich dissolution plume downstream over sediments inhabited by infaunal organisms and past small cages holding experimental animals. Changes in seawater chemistry were detected mainly by pH meters; the addition of CO2 to seawater elevates its CO2 levels, and reduces its pH (i.e. increases the acidity of seawater). We assessed the survival of various organisms (microbes, meiofauna [nematodes, amoebae, flagellates], macrofauna [sediment-dwelling worms and crustaceans], and megafauna [snails, sea urchins, sea cucumbers, octopus, fish] during month-long exposure to elevated CO2 levels in the dissolution plumes.The major results of these field experiments indicates that direct ocean injection of CO2 in the deep-sea will have variable, but generally negative effects on deep-sea ecosystems. Elevated CO2 levels cause physiological stress in many marine organisms, including respiratory stress, acidosis of intra-and inter-cellular spaces, and narcosis. The severity of effects on individual physiology vary among taxa, with echinoderms as the most sensitive taxon studies. The potential consequences for population and species level effects remain unknown. Effects will be most pronounced near sites of CO2 release, and the severity and...

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“…The laser wavelength was calibrated against the 801 ∆cm -1 Raman line of cyclohexane (22). A small diamond plate was placed inside the probe head in the laser beam path, so that the 1332 ∆cm -1 diamond Raman line is superimposed on all acquired spectra.…”

Section: Methodsmentioning

confidence: 99%

“…A neon source was used for wavelength calibration and a calibrated tungsten lamp was used for intensity calibration. The laser wavelength was checked by looking at the position of the 801 ∆cm -1 Raman line of cyclohexane (Tedesco and Davis, 1999 laser inside the probe head as a reference standard . The 1332 ∆cm -1 diamond Raman line is thus superimposed on all collected spectra as a calibration check.…”

Section: Raman Scatteringmentioning

confidence: 99%

Feasibility of Large-Scale Ocean CO2 Sequestration

Brewer¹,

Barry²

2005

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ABSTRACT:The project accomplishments in 2005 have been exceptional, and have seen radical new techniques successfully devised and implemented. At the outset the goal set was to create a system dubbed FOCE -Free Ocean CO 2 Enrichment -for investigating the impact of rapidly growing ocean CO 2 levels from passive absorption by the surface ocean. A paper describing progress in this area is included with this report. On June 29, 2005 the P.I. presented a seminar on this work at NETL, and after discussion with Program Officers it was suggested that a return to the original project focus of investigating direct disposal techniques, rather than passive disposal effects, should be undertaken. This suggestion was rapidly acted upon, and in November 2005 a major field breakthrough was accomplished in collaboration with colleagues from NETL, MIT, and AIST (Japan). In this effort the real time three-dimensional acoustic detection of a freely released small-scale CO 2 plume was accomplished. In addition we have successfully field tested the theoretical model of Zeebe and Wolf-Gladrow for CO 2 system kinetics at depth, thus leading to more accurate prediction of the local pH perturbations of a CO 2 plume. INTRODUCTION:This year has seen excellent progress in construction and testing of a new experimental array, FOCE -the Free Ocean CO 2 Experiment, systems both in the test tank and in field testing. A report prepared for a major engineering/science conference on the science enabled by the new generation of cabled sea floor systems is attached.The development of in situ laser Raman techniques, pioneered as novel technology under this award, has been completed, and major papers are listed in the appendix. The second generation system has proved exceptionally robust, and has been used at sea to explore the real time dissolution of liquid CO 2 source into sea water depth.With colleagues from Japan and Norway we have published the results of a difficult 4,000m deep CO 2 injection experiment designed to examine sensing of the plume emanating from a deep-sea CO 2 source. EXECUTIVE SUMMARY:We provide here documentation of progress in three critical areas relating to testing concepts of deep-ocean CO 2 disposal. i) Free Ocean CO 2 Enrichment (FOCE) Free air CO 2 enrichment experiments (FACE) are commonplace on land, and a large international network of experimental sites now exists. DoE takes credit for being the originator of such powerful and widely used technologies. But no ocean equivalent exists, in spite of the very large fossil fuel CO 2 changes taking place there -the ocean CO 2 invasion rate is now approximately 1 million tons per hour. We have designed and field tested a prototype system for carrying out such experiments (Fig. 1) Figure 1. The FOCE prototype system in the MBARI test tank. Opening and closing of the central valve assembly is guided by the vane. Acid flow is thus directed to the ring of soaker hose emitters, and feed-back is provided by a ring of pH sensors.The prototype system uses acid release to control ...

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<title>Calibration of dispersive Raman process analyzers</title>

Cited by 20 publications

References 0 publications

Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

Final Progress Report: Direct Experiments on the Ocean Disposal of Fossil Fuel CO2.

Feasibility of Large-Scale Ocean CO2 Sequestration

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