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Articles 1 - 13 of 13
Full-Text Articles in Social and Behavioral Sciences
A Fourier Transform Infrared Trace Gas And Isotope Analyser For Atmospheric Applications, D W. T Griffith, N M. Deutscher, C Caldow, G Kettlewell, M Riggenbach, S Hammer
A Fourier Transform Infrared Trace Gas And Isotope Analyser For Atmospheric Applications, D W. T Griffith, N M. Deutscher, C Caldow, G Kettlewell, M Riggenbach, S Hammer
Faculty of Science - Papers (Archive)
Concern in recent decades about human impacts on Earth's climate has led to the need for improved and expanded measurement capabilities of greenhouse gases in the atmosphere. In this paper we describe in detail an in situ trace gas analyser based on Fourier Transform Infrared (FTIR) spectroscopy that is capable of simultaneous and continuous measurements of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), nitrous oxide (N2O) and 13C in CO2 in air with high precision. High accuracy is established by reference to measurements of standard reference gases. Stable water isotopes can …
Gas-Particle Partitioning Of Atmospheric Hg(Ii) And Its Effect On Global Mercury Deposition, H M. Amos, D J. Jacob, C D. Holmes, Jenny A. Fisher, Q Wang, R M. Yantosca, E S. Corbitt, E Galarneau, A P. Rutter, M S. Gustin, A Steffen, J J. Schauer, J A. Graydon, V L. St Louis, R W. Talbot, E S. Edgerton, Y Zhang, E N. Sunderland
Gas-Particle Partitioning Of Atmospheric Hg(Ii) And Its Effect On Global Mercury Deposition, H M. Amos, D J. Jacob, C D. Holmes, Jenny A. Fisher, Q Wang, R M. Yantosca, E S. Corbitt, E Galarneau, A P. Rutter, M S. Gustin, A Steffen, J J. Schauer, J A. Graydon, V L. St Louis, R W. Talbot, E S. Edgerton, Y Zhang, E N. Sunderland
Faculty of Science - Papers (Archive)
Atmospheric deposition represents a major input of mercury to surface environments. The phase of mercury (gas or particle) has important implications for its removal from the atmosphere. We use long-term observations of reactive gaseous mercury (RGM), particle-bound mercury (PBM), fine particulate matter (PM2.5), and temperature at five sites in North America to derive an empirical gas-particle partitioning relationship log10(K-1) = (10 ± 1) − (2500 ± 300)/T where K = (PBM/PM2.5)/RGM with PBM and RGM in common mixing ratio units, PM2.5 in μg m−3, and T in …
Remote Real-Time Monitoring Of Subsurface Landfill Gas Migration, Cormac Fay, Aiden R. Doherty, Stephen T. Beirne, F Collins, C Foley, John Healy, Breda M. Kiernan, Hyowon Lee, Damien Maher, D Orpen, Thomas Phelan, Zhengwei Qiu, Kirk Zhang, Cathal Gurrin, Brian Corcoran, Noel E. O'Connor, A F Smeaton, D Diamond
Remote Real-Time Monitoring Of Subsurface Landfill Gas Migration, Cormac Fay, Aiden R. Doherty, Stephen T. Beirne, F Collins, C Foley, John Healy, Breda M. Kiernan, Hyowon Lee, Damien Maher, D Orpen, Thomas Phelan, Zhengwei Qiu, Kirk Zhang, Cathal Gurrin, Brian Corcoran, Noel E. O'Connor, A F Smeaton, D Diamond
Faculty of Science - Papers (Archive)
The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a …
Reactions Of Simple And Peptidic Alpha-Carboxylate Radical Anions With Dioxygen In The Gas Phase, Tony Ly, Benjamin B. Kirk, Pramesh I. Hettiarachchi, Berwyck L. Poad, Adam J. Trevitt, Gabriel Da Silva, Stephen J. Blanksby
Reactions Of Simple And Peptidic Alpha-Carboxylate Radical Anions With Dioxygen In The Gas Phase, Tony Ly, Benjamin B. Kirk, Pramesh I. Hettiarachchi, Berwyck L. Poad, Adam J. Trevitt, Gabriel Da Silva, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
α-Carboxylate radical anions are potential reactive intermediates in the free radical oxidation of biological molecules (e.g., fatty acids, peptides and proteins). We have synthesised well-defined α-carboxylate radical anions in the gas phase by UV laser photolysis of halogenated precursors in an ion-trap mass spectrometer. Reactions of isolated acetate (CH2CO 2-) and 1-carboxylatobutyl (CH3CH 2CH2CHCO2-) radical anions with dioxygen yield carbonate (CO3-) radical anions and this chemistry is shown to be a hallmark of oxidation in simple and alkyl-substituted cross-conjugated species. Previous solution phase studies have shown that Cα-radicals in peptides, formed from free radical damage, combine with dioxygen to form …
Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard
Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard
Faculty of Science - Papers (Archive)
This work describes a fully printable polyaniline-copper (II) chloride sensor for the detection of hydrogen sulfide gas. The sensing device is composed of screen printed silver interdigitated electrode (IDE) on a flexible PET substrate with inkjet printed layers of polyaniline and copper (II) chloride. The sensor is employed as a chemiresistor with changes in measured current being correlated with concentration. On exposure to hydrogen sulfide, 2.5 ppmv (parts per million by volume) is clearly detectable with a linear relationship between measured current and concentration over the 10-100 ppmv region. The detection mechanism is discussed with respect to the hydrogen sulfide …
Laboratory Measurements Of Trace Gas Emissions From Biomass Burning Of Fuel Types From The Southeastern And Southwestern United States, I R. Burling, R J. Yokelson, David W. Griffith, T J. Johnson, P Veres, J.M. Roberts, Carsten Warneke, S P. Urbanski, J Reardon, D R. Weise, W M Hao, Joost A. De Gouw
Laboratory Measurements Of Trace Gas Emissions From Biomass Burning Of Fuel Types From The Southeastern And Southwestern United States, I R. Burling, R J. Yokelson, David W. Griffith, T J. Johnson, P Veres, J.M. Roberts, Carsten Warneke, S P. Urbanski, J Reardon, D R. Weise, W M Hao, Joost A. De Gouw
Faculty of Science - Papers (Archive)
Vegetation commonly managed by prescribed burning was collected from five southeastern and southwestern US military bases and burned under controlled conditions at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The smoke emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP-FTIR) spectrometer for measurement of gas-phase species. The OP-FTIR detected and quantified 19 gas-phase species in these fires: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. Emission factors for these species are presented for each vegetation type burned. …
Autonomous Greenhouse Gas Measurement System For Analysis Of Gas Migration On Landfill Sites, Stephen Beirne, Breda M. Kierman, Cormac Fay, Colum Foley, Brian Corcoran, Alan F. Smeaton, Dermot Diamond
Autonomous Greenhouse Gas Measurement System For Analysis Of Gas Migration On Landfill Sites, Stephen Beirne, Breda M. Kierman, Cormac Fay, Colum Foley, Brian Corcoran, Alan F. Smeaton, Dermot Diamond
Faculty of Science - Papers (Archive)
This paper describes the design, development and validation of an autonomous gas sensing platform prototype for monitoring of the greenhouse gases, methane (CH4) and carbon dioxide (CO2). The deployment undertaken for validation of the developed prototype monitored landfill gas migration to perimeter borehole wells on a landfill site. Target gas concentrations were captured via infrared gas sensors tuned for each target gas and data reported to an offsite data collection point at 12 hour intervals. This bespoke platform and the accompanying data recording and interface software provide a flexible alternative to the presently employed labor intensive, …
The Major Toxin From The Australian Common Brown Snake Is A Hexamer With Unusual Gas-Phase Dissociation Properties, Andrew Aquilina
The Major Toxin From The Australian Common Brown Snake Is A Hexamer With Unusual Gas-Phase Dissociation Properties, Andrew Aquilina
Faculty of Science - Papers (Archive)
Asymmetric dissociation of multiply charged proteins assemblies has been frequently reported. This phenomenon, which relies on the dissociation of one or more highly charged monomers, has been shown to provide insights into the structure and organization of large monodisperse and polydisperse assemblies. Here, the process of asymmetric dissociation is investigated using the multi-subunit protein, textilotoxin, which has unusually high structural constraints on its monomers due to multiple disulfide linkages. Initially, it is shown that, contrary to previous reports, textilotoxin is made up of 6, rather than 5 subunits. Furthermore, the hexamer exists as two isoforms, one of which is substantially …
Fragmentation Pathways Of 2,3-Dimethyl-2,3-Dinitrobutane Cations In The Gas Phase, Martin Paine, Benjamin Kirk, Simon Ellis-Steinborner, Stephen J. Blanksby
Fragmentation Pathways Of 2,3-Dimethyl-2,3-Dinitrobutane Cations In The Gas Phase, Martin Paine, Benjamin Kirk, Simon Ellis-Steinborner, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
2,3-Dimethyl-2,3-dinitrobutane (DMNB) is an explosive taggant added to plastic explosives during manufacture making them more susceptible to vapour-phase detection systems. In this study, the formation and detection of gas-phase [M+H](+), [M+Li](+), [M+NH4](+) and [M+Na](+) adducts of DMNB was achieved using electrospray ionisation on a triple quadrupole mass spectrometer. The [M+H](+) ion abundance was found to have a strong dependence on ion source temperature, decreasing markedly at source temperatures above 50 degrees C. In contrast, the [M+Na](+) ion demonstrated increasing ion abundance at source temperatures up to 105 degrees C. The relative susceptibility of DMNB adduct ions toward dissociation was investigated …
Fabrication Of Chemical Sensors Using Inkjet Printing And Application To Gas Detection, Karl H. Crowley, Aoife Morrin, Malcolm R. Smyth, Anthony J. Killard, Roderick Shepherd, Marc In Het Panhuis, Gordon G. Wallace
Fabrication Of Chemical Sensors Using Inkjet Printing And Application To Gas Detection, Karl H. Crowley, Aoife Morrin, Malcolm R. Smyth, Anthony J. Killard, Roderick Shepherd, Marc In Het Panhuis, Gordon G. Wallace
Faculty of Science - Papers (Archive)
This work describes the fabrication of gas sensors using inkjet printing. Sensors were constructed by building up a film of sensing material, such as polyaniline, from aqueous nanoparticulate dispersions. These films were printed over patterned silver interdigitated array designs for the purposes of conductimetric analysis. Unlike screen printing or lithography, inkjet printing does not require stencils or masks, therefore allowing rapid design and prototyping. For this study, polyaniline and modified polyaniline sensors were inkjet printed and assessed for the purposes of gas sensing applications, specifically hydrogen sulfide monitoring.
Base-Induced Decomposition Of Alkyl Hydroperoxides In The Gas Phase. Part 3. Kinetics And Dynamics In Ho + Ch3ooh, C2h5ooh, And Tert-C4h9ooh Reactions, Shuji Kato, G Barney Ellison, Veronica Bierbaum, Stephen J. Blanksby
Base-Induced Decomposition Of Alkyl Hydroperoxides In The Gas Phase. Part 3. Kinetics And Dynamics In Ho + Ch3ooh, C2h5ooh, And Tert-C4h9ooh Reactions, Shuji Kato, G Barney Ellison, Veronica Bierbaum, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
The ECO2 elimination reactions of alkyl hydroperoxides proceed via abstraction of an α-hydrogen by a base: X− + R1R2HCOOH → HX + R1R2CO + HO−. Efficiencies and product distributions for the reactions of the hydroxide anion with methyl, ethyl, and tert-butyl hydroperoxides are studied in the gas phase. On the basis of experiments using three isotopic analogues, HO− + CH3OOH, HO− + CD3OOH, and H18O− + CH3OOH, the overall intrinsic reaction efficiency is determined to …
Reactions Of The Hydroperoxide Anion With Dimethyl Methylphosphonate In An Ion Trap Mass Spectrometer: Evidence For A Gas Phase A-Effect, Andrew M Mcanoy, Martin Paine, Stephen J. Blanksby
Reactions Of The Hydroperoxide Anion With Dimethyl Methylphosphonate In An Ion Trap Mass Spectrometer: Evidence For A Gas Phase A-Effect, Andrew M Mcanoy, Martin Paine, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
The gas phase degradation reactions of the chemical warfare agent (CWA) simulant, dimethyl methylphosphonate (DMMP), with the hydroperoxide anion (HOO–) were investigated using a modified quadrupole ion trap mass spectrometer. The HOO– anion reacts readily with neutral DMMP forming two significant product ions at m/z 109 and m/z 123. The major reaction pathways correspond to (i) the nucleophilic substitution at carbon to form [CH3P(O)(OCH3)O]– (m/z 109) in a highly exothermic process and (ii) exothermic proton transfer. The branching ratios of the two reaction pathways, 89% and 11% respectively, indicate that the …
The Loss Of Carbon Dioxide From Activated Perbenzoate Anions In The Gas Phase: Unimolecular Rearrangement Via Epoxidation Of The Benzene Ring, David G. Harman, Aravind Ramachandran, Michelle Gracanin, Stephen J. Blanksby
The Loss Of Carbon Dioxide From Activated Perbenzoate Anions In The Gas Phase: Unimolecular Rearrangement Via Epoxidation Of The Benzene Ring, David G. Harman, Aravind Ramachandran, Michelle Gracanin, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
The unimolecular reactivities of a range of perbenzoate anions (X−C6H5CO3-), including the perbenzoate anion itself (X = H), nitroperbenzoates (X = para-, meta-, ortho-NO2), and methoxyperbenzoates (X = para-, meta-OCH3) were investigated in the gas phase by electrospray ionization tandem mass spectrometry. The collision-induced dissociation mass spectra of these compounds reveal product ions consistent with a major loss of carbon dioxide requiring unimolecular rearrangement of the perbenzoate anion prior to fragmentation. Isotopic labeling of the perbenzoate anion supports rearrangement via an initial nucleophilic aromatic …