scholarly journals H<sub>2</sub>S interference on CO<sub>2</sub> isotopic measurements using a Picarro G1101-i cavity ring-down spectrometer

2015 ◽  
Vol 8 (10) ◽  
pp. 4075-4082 ◽  
Author(s):  
K. Malowany ◽  
J. Stix ◽  
A. Van Pelt ◽  
G. Lucic
Keyword(s):  
Hydrogen Sulfide ◽  
Field Trials ◽  
Spectral Lines ◽  
Robust Method ◽  
Controlled Experiments ◽  
Δ13c Value ◽  
Future Work ◽  
Isotopic Measurements ◽  
Standard Gas ◽  
Cavity Ring Down

Abstract. Cavity ring-down spectrometers (CRDSs) have the capacity to make isotopic measurements of CO2 where concentrations range from atmospheric (~ 400 ppm) to 6000 ppm. Following field trials, it has come to light that the spectrographic lines used for CO2 have an interference with elevated (higher than ambient) amounts of hydrogen sulfide (H2S), which causes significant depletions in the δ13C measurement by the CRDSs. In order to deploy this instrument in environments with elevated H2S concentrations (i.e., active volcanoes), we require a robust method for eliminating this interference. Controlled experiments using a Picarro G1101-i optical spectrometer were done to characterize the H2S interference at varying CO2 and H2S concentrations. The addition of H2S to a CO2 standard gas reveals an increase in the 12CO2 concentration and a more significant decrease in the 13CO2 concentration, resulting in a depleted δ13C value. Reacting gas samples containing H2S with copper prior to analysis can eliminate this effect. Models post-dating the G1101-i carbon isotope analyzer have maintained the same spectral lines for CO2 and are likely to have a similar H2S response at elevated H2S concentrations. It is important for future work with CRDS, particularly in volcanic regions where H2S is abundant, to be aware of the H2S interference on the CO2 spectroscopic lines and to remove all H2S prior to analysis. We suggest employing a scrub composed of copper to remove H2S from all gas samples that have concentrations in excess of 1 ppb.

scholarly journals H<sub>2</sub>S interference on CO<sub>2</sub> isotopic measurements using a Picarro G1101-i cavity ring-down spectrometer

2015 ◽  
Vol 8 (6) ◽  
pp. 5651-5675 ◽  
Author(s):  
K. Malowany ◽  
J. Stix ◽  
A. Van Pelt ◽  
G. Lucic
Keyword(s):  
Carbonyl Sulfide ◽  
Co2 Concentration ◽  
Field Trials ◽  
Robust Method ◽  
Controlled Experiments ◽  
Δ13c Value ◽  
Future Work ◽  
Isotopic Measurements ◽  
Standard Gas ◽  
Cavity Ring Down

Abstract. Cavity ring-down spectrometers (CRDS) have the capacity to make isotopic measurements of CO2 where concentrations range from atmospheric (~ 400 ppm) to 6000 ppm. Following field trials, it has come to light that the spectrographic lines used for CO2 have an interference with elevated (higher than ambient) amounts of hydrogen sulfide (H2S), which causes significant depletions in the δ13C measurement by the CRDS. In order to deploy this instrument in environments with elevated H2S concentrations (i.e., active volcanoes), we require a robust method for eliminating this interference. Controlled experiments using a Picarro G1101-i optical spectrometer were done to characterize the H2S interference at varying CO2 and H2S concentrations. The addition of H2S to a CO2 standard gas reveals an increase in the 12CO2 concentration and a more significant decrease in the 13CO2 concentration, resulting in a depleted δ13C value. Reacting gas samples containing H2S with copper prior to analysis can eliminate this effect. However, experiments also revealed that the addition of H2S to CO2 results in the formation of carbonyl sulfide (OCS) and carbon disulfide (CS2), causing a decrease in the overall CO2 concentration without affecting the δ13C value. It is important for future work with CRDS, particularly in volcanic regions where H2S is abundant, to be aware of the H2S interference on the CO2 spectroscopic lines and to remove all H2S prior to analysis. We suggest employing a scrub composed of copper to remove H2S from all gas samples that have concentrations in excess of 1 ppb.

Sterically stabilized self-assembling reversibly cross-linked polyelectrolyte complexes with nucleic acids for environmental and medical applications

2009 ◽  
Vol 37 (4) ◽  
pp. 713-716 ◽  
Author(s):  
Martin C. Garnett ◽  
Paolo Ferruti ◽  
Elisabetta Ranucci ◽  
Marco A. Suardi ◽  
Mieke Heyde ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Field Trials ◽  
Cross Linking ◽  
Medical Applications ◽  
Nucleic Acid Delivery ◽  
Poly Ethylene Glycol ◽  
Polyelectrolyte Complexes ◽  
Self Assembling ◽  
Poly Ethylene ◽  
Future Work

One of the principal problems facing nucleic acid delivery systems using polyplexes is the instability of the complexes in the presence of proteins and high salt concentrations. We have used a cross-linking polymer to overcome this problem. Pendant thiol moieties have been incorporated into a PAA (polyamidoamine) homopolymer and a PEG [poly(ethylene glycol)]–PAA–PEG copolymer reported previously as a self-assembling system. When mixed with DNA, small monodisperse sterically stabilized particles are formed in quantitative yields. Optimization of the formulation resulted in nanoparticles which are stable in seawater. This cross-linked formulation has been successfully tested in both freshwater and estuarine field trials as a water tracer. Future work will develop these particles as a groundwater tracer and also for therapeutic applications of nucleic acid delivery.

Effect of Florpyrauxifen-benzyl Formulation and Rate for Waterhyacinth Control in a Mesocosm Setting

2021 ◽  
pp. 1-17
Author(s):  
Christopher R. Mudge ◽  
Gray Turnage ◽  
Michael D. Netherland
Keyword(s):  
Eichhornia Crassipes ◽  
Field Trials ◽  
Effective Control ◽  
Control Methods ◽  
Limited Information ◽  
National Legislation ◽  
Plant Recovery ◽  
Synthetic Auxin ◽  
Future Work ◽  
The U.S

Abstract Waterhyacinth (Eichhornia crassipes) has been the focus of national legislation efforts and has been listed as noxious, invasive, potentially invasive, or prohibited by at least seven U.S. states. Auxinic herbicides are one of the most effective control methods labeled for use in aquatic sites. In the U.S., florpyrauxifen-benzyl, a synthetic auxin, was recently (2018) registered for use in aquatic sites, but limited information has been published on efficacy, especially differences between the two formulations. Therefore, the purpose of this work was to evaluate two formulations of florpyrauxifen-benzyl – suspension concentrate (SC) and emulsifiable concentrate (EC) – at three rates each (5.9, 11.8, and 23.6 g a.i. ha-1) for control of waterhyacinth under outdoor and greenhouse conditions. All rates of each florpyrauxifen-benzyl formulation reduced waterhyacinth biomass by 90 to 100% when compared to non-treated plants at five weeks after treatment (WAT). Based on plant recovery in the outdoor trial, there was some evidence that the lowest rate (5.9 g a.i. ha-1) of florpyrauxifen-benzyl SC and EC may not be as efficacious at reducing waterhyacinth biomass as the SC and EC formulations when applied at 11.8 and 23.6 g a.i. ha-1. Future work should evaluate the florpyrauxifen-benzyl rates tested in this research against waterhyacinth in field trials and/or an operational setting to confirm findings.

scholarly journals A Robust Method to Measure Centroids of Spectral Lines

2018 ◽  
Vol 2 (3) ◽  
pp. 173 ◽  
Author(s):  
Richard Teague ◽  
Daniel Foreman-Mackey
Keyword(s):  
Spectral Lines ◽  
Robust Method

Challenge and Review of Hydrogen Sulfide Corrosion Resistance Steels for Oil Country Tubular Goods

2020 ◽  
Vol 993 ◽  
pp. 1203-1208
Author(s):  
Ya Cong Song ◽  
Chun Feng ◽  
Li Juan Zhu ◽  
Ya Qiong Cao ◽  
Hong Jiang Ge
Keyword(s):  
Corrosion Resistance ◽  
Hydrogen Sulfide ◽  
Oil And Gas ◽  
Economic Loss ◽  
Research Progress ◽  
Corrosion Performance ◽  
Corrosion Failure ◽  
Sulfide Corrosion ◽  
Future Work ◽  
Hydrogen Sulfide Corrosion

Corrosion of oil country tubular goods not only causes huge economic loss, but also brings serious environmental pollution. Stress corrosion cracking of oil country tubular goods in the sulfur-containing environment is the principal corrosion failure form in the exploitation of oil and gas process. Therefore, extensive investigations on hydrogen sulfide corrosion of steels for oil country tubular goods have been carried out. The aim of this work is to review the research progress on the hydrogen sulfide corrosion performance of steels for oil country tubular goods. The influence of alloy elements, defects, environmental factors and mechanical factors on hydrogen sulfide corrosion resistance of steels for oil country tubular goods were discussed. The future work in hydrogen sulfide corrosion performance of oil country tubular good and new sulfur-resistant steels for oil country tubular goods development were prospected.

scholarly journals Systematic Modification of Zingerone Reveals Structural Requirements for Attraction of Jarvis’s Fruit Fly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Benjamin L. Hanssen ◽  
Soo Jean Park ◽  
Jane E. Royer ◽  
Joanne F. Jamie ◽  
Phillip W. Taylor ◽  
...  
Keyword(s):  
Fruit Fly ◽  
Field Trials ◽  
Fruit Flies ◽  
Monitoring And Control ◽  
Structural Modifications ◽  
Phenolic Esters ◽  
Key Sites ◽  
And Control ◽  
Future Work ◽  
Tephritid Fruit Flies

AbstractTephritid fruit flies are amongst the most significant horticultural pests globally and male chemical lures are important for monitoring and control. Zingerone has emerged as a unique male fruit fly lure that can attract dacine fruit flies that are weakly or non-responsive to methyl eugenol and cuelure. However, the key features of zingerone that mediate this attraction are unknown. As Jarvis’s fruit fly, Bactrocera jarvisi (Tryon), is strongly attracted to zingerone, we evaluated the response of B. jarvisi to 37 zingerone analogues in a series of field trials to elucidate the functional groups involved in attraction. The most attractive analogues were alkoxy derivatives, with isopropoxy being the most attractive, followed by ethoxy and trifluoromethoxy analogues. All of the phenolic esters tested were also attractive with the response typically decreasing with increasing size of the ester. Results indicate that the carbonyl group, methoxy group, and phenol of zingerone are key sites for the attraction of B. jarvisi and identify some constraints on the range of structural modifications that can be made to zingerone without compromising attraction. These findings are important for future work in developing and optimising novel male chemical lures for fruit flies.

scholarly journals Removal of Hydrogen Sulfide From Various Industrial Gases: A Review of The Most Promising Adsorbing Materials

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 521 ◽  
Author(s):  
Amvrosios Georgiadis ◽  
Nikolaos Charisiou ◽  
Maria Goula
Keyword(s):  
Hydrogen Sulfide ◽  
Metal Oxides ◽  
Oil And Gas ◽  
Activated Carbons ◽  
Regeneration Time ◽  
Adsorption Capacities ◽  
H2s Adsorption ◽  
Industrial Gases ◽  
And Performance ◽  
Future Work

The separation of hydrogen sulfide (H2S) from gas streams has significant economic and environmental repercussions for the oil and gas industries. The present work reviews H2S separation via nonreactive and reactive adsorption from various industrial gases, focusing on the most commonly used materials i.e., natural or synthetic zeolites, activated carbons, and metal oxides. In respect to cation-exchanged zeolites, attention should also be paid to parameters such as structural and performance regenerability, low adsorption temperatures, and thermal conductivities, in order to create more efficient materials in terms of H2S adsorption. Although in the literature it is reported that activated carbons can generally achieve higher adsorption capacities than zeolites and metal oxides, they exhibit poor regeneration potential. Future work should mainly focus on finding the optimum temperature, solvent concentration, and regeneration time in order to increase regeneration efficiency. Metal oxides have also been extensively used as adsorbents for hydrogen sulfide capture. Among these materials, ZnO and Cu–Zn–O have been studied the most, as they seem to offer improved H2S adsorption capacities. However, there is a clear lack of understanding in relation to the basic sulfidation mechanisms. The elucidation of these reaction mechanisms will be a toilsome but necessary undertaking in order to design materials with high regenerative capacity and structural reversibility.

Parametric Roll: Highly Controlled Experiments for an Innovative Ship Design

2008 ◽  
Author(s):  
A. Olivieri ◽  
A. Francescutto ◽  
E. F. Campana ◽  
F. Stern
Keyword(s):  
Theoretical Models ◽  
Ship Design ◽  
Controlled Experiments ◽  
Cooperative Research ◽  
Parametric Roll ◽  
Head Waves ◽  
Optical Motion ◽  
The Subject ◽  
Decay Tests ◽  
Future Work

The present work is focused on ship’s parametric roll. In particular, a series of controlled experiments have been performed in order to obtain repeatable results both for the inception and the roll amplitude in parametric roll condition. The experiments have been performed for an innovative ship design (a tumblehome shape) in a towing tank provided by a flap-type wave maker. The model was tested in 3 DoF conditions, being roll, pitch and heave motions free and surge, sway and yaw restrained. The experimental work, which is the subject of the present paper, is part of cooperative research project between the IIHR (Iowa Institute of Hydraulic Research), the University of Trieste and the Italian ship model basin (INSEAN) (1, 2). All the experiments have been carried out in head waves at the INSEAN basin n. 2. The model motions were measured both by an optical motion tracker (Krypton) and a gyroscopic platform (MOTAN). Tests were carried out for three different metacentric heights in a range of speeds. Roll decay tests as a function of forward speed were performed before every experiment in waves in order to determine the natural roll frequency and the roll decay rate. The head waves experiments showed parametric roll excitation for different metacentric heights, wave steepness and Froude number. The repeatability of the obtained results, allows to use them as a benchmark for both CFD codes and theoretical models. This will be the subject of a future work, which is at present in preparation and involves other international collaborations beyond the ones listed here.

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