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Full-Text Articles in Physical Sciences and Mathematics
Fouling Resistant Compact Hollow-Fiber Module With Spacer For Submerged Membrane Bioreactor Treating High Strength Industrial Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi, Fumiyuki Nakajima
Fouling Resistant Compact Hollow-Fiber Module With Spacer For Submerged Membrane Bioreactor Treating High Strength Industrial Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi, Fumiyuki Nakajima
Faisal I Hai
Long-term investigations carried out in a submerged membrane fungi reactor treating textile wastewater revealed the excellent fouling prevention capacity of spacer-filled hollow-fiber modules. The type and arrangement of the spacers governed the overall rigidity of the modules and played the critical role in avoidance of sludge intrusion and retrieval of the original state (cleaning). A hybrid module (fiber packing density = 61.5%, surface area = 1.07 m2) obtained by winding a rigid spacer (thickness = 1 mm, opening = 7 mm × 7 mm) on the surface of a module originally containing a flexible thin spacer (opening = 1 mm …
Performance Of Newly Developed Hollow Fiber Module With Spacer In Integrated Anaerobic–Aerobic Fungi Reactor Treating Textile Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Performance Of Newly Developed Hollow Fiber Module With Spacer In Integrated Anaerobic–Aerobic Fungi Reactor Treating Textile Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Faisal I Hai
A submerged microfiltration membrane bioreactor implementing the white-rot fungus Coriolus versicolor was developed for effective treatment of textile dye wastewater [1]. In that system membrane fouling was precluded by placing a bundle of hollow fibers within a pre-filtration assembly, so as to avoid direct deposition of sludge onto it, together with its periodic high-pressure back-washing and low-dose chemical back-flushing. However, the extreme vulnerability of the bare membrane used in that study to inter-fibral deposition of sludge leading to merging of fibers indicated necessity of development of an appropriate module so that the proposed system may enjoy more flexibility in terms …
Development Of A Submerged Membrane Fungi Reactor For Textile Wastewater Treatment, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Development Of A Submerged Membrane Fungi Reactor For Textile Wastewater Treatment, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Faisal I Hai
A submerged microfiltration membrane bioreactor implementing the white-rot fungus Coriolus versicolor was developed for the treatment of textile dye wastewater following explorations with different fouling-prevention techniques. The optimum combination ensuring permeate quality and precluding membrane fouling comprises of placing a bundle of hollow fibers within a non-woven coarse-pore (50–200 μm) mesh cage, so as to avoid direct deposition of sludge onto it, together with arrangements for its periodic high-pressure back-washing (3 s/10 min) and chemical back-flushing (100 ml/m2, every third day). Under controlled temperature (29±1°C) and pH (4.5±0.2), and applied HRT and an average flux of 15 h and 0.021 …
Hybrid Treatment Systems For Dye Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Hybrid Treatment Systems For Dye Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Faisal I Hai
Virtually all the known physico-chemical and biological techniques have been explored for treatment of extremely recalcitrant dye wastewater; none, however, has emerged as a panacea. A single universally applicable end-of-pipe solution appears to be unrealistic, and combination of appropriate techniques is deemed imperative to devise technically and economically feasible options. An in-depth evaluation of wide range of potential hybrid technologies delineated in literature along with plausible analyses of available cost information has been furnished. In addition to underscoring the indispensability of hybrid technologies, this paper also endorses the inclusion of energy and water reuse plan within the treatment scheme, and …
Membrane Coupled Fungi Reactor - An Innovative Approach To Bioremediation Of Hazardous Dye Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Membrane Coupled Fungi Reactor - An Innovative Approach To Bioremediation Of Hazardous Dye Wastewater, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Faisal I Hai
Virtually all the known physico-chemical and biological techniques have been explored for treatment of extremely recalcitrant dye wastewater; none, however, has emerged as a panacea. A single universally applicable end-of-pipe solution appears to be unrealistic, and combination of appropriate techniques is deemed imperative to devise technically and economically feasible options. An in-depth evaluation of wide range of potential hybrid technologies delineated in literature along with plausible analyses of available cost information has been furnished. In addition to underscoring the indispensability of hybrid technologies, this paper also endorses the inclusion of energy and water reuse plan within the treatment scheme, and …
Recalcitrant Industrial Wastewater Treatment By Membrane Bioreactor (Mbr), Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Recalcitrant Industrial Wastewater Treatment By Membrane Bioreactor (Mbr), Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Faisal I Hai
Membrane Bioreactor (MBR) process consists of a biological reactor integrated with membranes that combine clarification and filtration of an activated sludge process into a simplified, single step process. The membrane is an absolute barrier to suspended matter and microorganisms and it offers the possibility of operating the system at high mixed liquor suspended solids (MLSS) concentration. The implication of maintenance of high MLSS are— requirement of a smaller footprint and operation at high solids retention time (SRT) under low F/M ratio, hence, yielding reduced excess sludge. Operating as an MBR allows conventional activated sludge plants to become single step processes, …
Factors Governing Performance Of Continuous Fungal Reactor During Non-Sterile Operation - The Case Of A Membrane Bioreactor Treating Textile Wastewater, Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Factors Governing Performance Of Continuous Fungal Reactor During Non-Sterile Operation - The Case Of A Membrane Bioreactor Treating Textile Wastewater, Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Faisal I Hai
White-rot fungi, unlike bacteria in conventional activated sludge system, can degrade wide varieties of textile dyes. Their large scale implementation, however, has been impeded due to lack of appropriate reactor system that can sustain stable performance under non-sterile environment. In this study, contrary to virtually complete decoloration of an azo dye (Acid Orange II, 100 mg L−1) in pure culture batch test, a fungal membrane bioreactor (MBR) achieved 93% removal during long-term non-sterile operation at a hydraulic retention time (HRT) of 1 d. Through a set of novel observations made in MBR and parallel batch tests, the interrelated factors responsible …
Different Fouling Modes Of Submerged Hollow-Fiber And Flat-Sheet Membranes Induced By High Strength Wastewater With Concurrent Biofouling, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Different Fouling Modes Of Submerged Hollow-Fiber And Flat-Sheet Membranes Induced By High Strength Wastewater With Concurrent Biofouling, Faisal I. Hai, Kazuo Yamamoto, Kensuke Fukushi
Faisal I Hai
Exploration of two major commercialized flat-sheet and hollow-fiber membranes in a submerged membrane fungi reactor fed with a synthetic textile wastewater revealed striking differences in the extent and mechanism of fouling between the two types, indicating a case-specific scope of choice between the two for industrial wastewater treatment. The hollow-fiber membrane exhibited fouling with a cake layer composed of fungi and starch, intensity being proportional to the operating flux (0.05–0.3 m/d). Conversely, the flat-sheet membrane suffered from immediate internal pore blocking beyond a critical flux of 0.2 m/d. During the experiment with major constituents of the synthetic wastewater separately, while …
Removal Of Structurally Different Dyes In Submerged Membrane Fungi Reactor—Biosorption/Pac-Adsorption, Membrane Retention And Biodegradation, Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Removal Of Structurally Different Dyes In Submerged Membrane Fungi Reactor—Biosorption/Pac-Adsorption, Membrane Retention And Biodegradation, Faisal I. Hai, Kazuo Yamamoto, Fumiyuki Nakajima, Kensuke Fukushi
Faisal I Hai
The long-term performance of a submerged membrane fungi reactor was observed while a synthetic textile wastewater containing either or both of the two structurally different azo dyes was continuously fed. Compared to the Acid Orange II dye (simpler structure), higher biosorption but slower biodegradation of the polymeric dye (Poly S119) was observed in sterile batch tests. In the membrane bioreactor (MBR), although a relative abundance of fungi (66%) without any specific control of bacterial contamination could be maintained, unlike in pure fungus culture, enzymatic activity was below detection limit. Nevertheless, >99% removal of Poly S119 was consistently achieved under a …
Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom
Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom
Adam Trevitt
The Gn test sets(1) of accurate (uncertainty ≤ 1 kcal mol–1 ≈ 4 kJ mol–1) experimental data are widely employed in the development and assessment of quantum chemistry procedures. However, while all the data in the Gn sets nominally carry a sub-kcal mol–1 uncertainty, several of the experimental values show uncharacteristically large discrepancies when compared with values determined by high-level theoretical calculations. One of these questionable values is the adiabatic ionization energy (IE) of B2F4, for which the theoretical values calculated, for example, with the high-level G2 (1133.9, kJ mol–1),(1b) G3 (1135.4 kJ mol–1),(2) and G4 (1127.2 kJ mol–1)(3) procedures …
The Geomorphological Evolution Of A Wave-Dominated Barrier Estuary: Burrill Lake, New South Wales, Australia, Brian G. Jones, Craig R. Sloss, David M. Price, C.E. Mcclennen, John De Carli
The Geomorphological Evolution Of A Wave-Dominated Barrier Estuary: Burrill Lake, New South Wales, Australia, Brian G. Jones, Craig R. Sloss, David M. Price, C.E. Mcclennen, John De Carli
B. G. Jones
The geomorphological evolution of the Holocene wave-dominated barrier estuary at Burrill Lake on the New South Wales coast, Australia, has been delineated using a combination of seismic stratigraphy and the lithostratigraphic analysis of vibracores collected from the back-barrier estuarine environment. A combination of radiocarbon and aspartic acid racemisation-derived ages obtained on Holocene fossil molluscs, and the thermoluminescent signal in remnant Last Interglacial barrier sediments provides the chronological framework for this investigation. Results from this paper show that the barrier estuary occupies a relatively narrow (<1.5 km wide) and shallow (<40 m deep) incised bedrock valley formed during sea-level …
Cyclicity In The Nearshore Marine To Coastal, Lower Permian, Pebbley Beach Formation, Southern Sydney Basin, Australia: A Record Of Relative Sea-Level Fluctuations At The Close Of The Late Palaeozoic Gondwanan Ice Age, Brian G. Jones, Stuart C. Tye, James A. Maceachern, Kerrie L. Bann, Christopher R. Fielding
Cyclicity In The Nearshore Marine To Coastal, Lower Permian, Pebbley Beach Formation, Southern Sydney Basin, Australia: A Record Of Relative Sea-Level Fluctuations At The Close Of The Late Palaeozoic Gondwanan Ice Age, Brian G. Jones, Stuart C. Tye, James A. Maceachern, Kerrie L. Bann, Christopher R. Fielding
B. G. Jones
The Lower Permian (Artinskian to Sakmarian) Pebbley Beach Formation of the southernmost Sydney Basin in New South Wales, Australia, records sediment accumulation in shallow marine to coastal environments at the close of the Late Palaeozoic Gondwanan ice age. This paper presents a sequence stratigraphic re-evaluation of the upper half of the unit based on the integration of sedimentology and ichnology. Ten facies are recognized, separated into two facies associations. Facies Association A (7 facies) comprises variably bioturbated siltstones and sandstones with marine body fossils, interpreted to record sediment accumulation in open marine environments ranging from lower offshore to middle shoreface …
Aeolian-Fluvial Interaction: Evidence For Late Quaternary Channel Change And Wind-Rift Linear Dune Formation In The Northwestern Simpson Desert, Australia, Gerald C. Nanson, Brian G. Jones, David M. Price, Tim Pietsch, C Bristow, Cameron B. Hollands
Aeolian-Fluvial Interaction: Evidence For Late Quaternary Channel Change And Wind-Rift Linear Dune Formation In The Northwestern Simpson Desert, Australia, Gerald C. Nanson, Brian G. Jones, David M. Price, Tim Pietsch, C Bristow, Cameron B. Hollands
B. G. Jones
In central Australia the most easterly extent of the MacDonnell Ranges borders the northwestern Simpson Desert where widely spaced strike ridges intercept the regional linear dunefield. Topographic basins have disrupted regional drainage lines and isolated dune sets from the main dunefield. In the western part of Camel Flat basin large, red coloured linear dunes of fine sand, ~ 74 ka and older, are oriented almost due north. Through gaps in the ranges the Todd River traversed the eastern part of the basin until ~25 ka when it apparently avulsed ~25 km eastwards to its present position. Subsequently, linear dunes, smaller, …
Assessing Soil Remobilisation In Catchments Using A 137 Cs-Sediment Hillslope Model, Ava D. Simms, Colin D. Woodroffe, Brian G. Jones, Henk Heijnis, Jennifer Harrison, Rob Mann
Assessing Soil Remobilisation In Catchments Using A 137 Cs-Sediment Hillslope Model, Ava D. Simms, Colin D. Woodroffe, Brian G. Jones, Henk Heijnis, Jennifer Harrison, Rob Mann
B. G. Jones
Soil redistribution studies are important, especially in water supply catchments, because the rate at which denudation is occurring has implications for offsite water quality. However, the extent to which soil is redistributed within the landscape can be difficult to determine. This challenge can be overcome using fallout caesium-137 (137Cs). This paper describes the rates of soil loss and remobilisation in two sub-catchments within the Sydney Basin region, namely Kembla and Kentish Creeks, which drain to the Cordeaux reservoir. The total inventories of 137Cs in catchment soils were determined, a 137Cs-regression equation and a theoretical diffusion and migration model were used …
Investigation Of Large-Scale Washover Of A Small Barrier System On The Southeast Australian Coast Using Ground Penetrating Radar, Brian G. Jones, C Bristow, Adam D. Switzer
Investigation Of Large-Scale Washover Of A Small Barrier System On The Southeast Australian Coast Using Ground Penetrating Radar, Brian G. Jones, C Bristow, Adam D. Switzer
B. G. Jones
Prehistoric depositional signatures for large-scale washover involving marine inundation events such as storm and tsunami have been the subject of considerable research over the last 15 years. Much of this research has focused on the identification of sand sheets in back-barrier environments as depositional records for extreme washover events. All these deposits must have a sediment source, and by their nature, the most likely source of sediment for washover into back-barrier environments is the barrier itself. This study identifies an erosional signature for large-scale washover from a small coastal barrier on the southeast Australian coast. A distinct lense of marine …
Climate Change In The Dead Heart Of Australia, Joshua Larsen, Gerald C. Nanson, Timothy J. Cohen, Brian G. Jones, John D. Jansen, Jan-Hendrik May
Climate Change In The Dead Heart Of Australia, Joshua Larsen, Gerald C. Nanson, Timothy J. Cohen, Brian G. Jones, John D. Jansen, Jan-Hendrik May
B. G. Jones
Despite the absence of large-scale glaciation, the Australian continent has experienced substantial environmental change throughout the Quaternary period. This is especially pronounced in central Australia, where one seventh of the continent is drained internally to the depocentre, and lowest point in Australia, Lake Eyre (Figure 1). Research has shown that at one time, large sandy braided and meandering rivers carried water through dunefields to a large freshwater lake system. Today, the rivers are hostage to the dunefield, and floodwaters might only reach Lake Eyre once every ten years or so. In order to understand the development of this arid desert …
Response Of Coral Reefs To Climate Change: Expansion And Demise Of The Southernmost Pacific Coral Reef, Colin D. Woodroffe, Brendan P. Brooke, Michelle Linklater, David M. Kennedy, Brian G. Jones, Cameron Buchanan, Richard Mleczko, Quan Hua, Jian-Xin Zhao
Response Of Coral Reefs To Climate Change: Expansion And Demise Of The Southernmost Pacific Coral Reef, Colin D. Woodroffe, Brendan P. Brooke, Michelle Linklater, David M. Kennedy, Brian G. Jones, Cameron Buchanan, Richard Mleczko, Quan Hua, Jian-Xin Zhao
B. G. Jones
Coral reefs track sea level and are particularly sensitive to changes in climate. Reefs are threatened by global warming, with many experiencing increased coral bleaching. Warmer sea surface temperatures might enable reef expansion into mid latitudes. Here we report multibeam sonar and coring that reveal an extensive relict coral reef around Lord Howe Island, which is fringed by the southernmost reef in the Pacific Ocean. The relict reef, in water depths of 25-50 m, flourished in early Holocene and covered an area more than 20 times larger than the modern reef. Radiocarbon and uranium-series dating indicates that corals grew between …
Continental Aridification And The Vanishing Of Australia's Megalakes, Timothy J. Cohen, Gerald C. Nanson, John D. Jansen, B. G. Jones, Zenobia Jacobs, P Treble, David M. Price, Jan-Hendrik May, A Smith, Linda K. Ayliffe, John C. Hellstrom
Continental Aridification And The Vanishing Of Australia's Megalakes, Timothy J. Cohen, Gerald C. Nanson, John D. Jansen, B. G. Jones, Zenobia Jacobs, P Treble, David M. Price, Jan-Hendrik May, A Smith, Linda K. Ayliffe, John C. Hellstrom
B. G. Jones
The nature of the Australian climate at about the time of rapid megafaunal extinctions and humans arriving in Australia is poorly understood and is an important element in the contentious debate as to whether humans or climate caused the extinctions. Here we present a new paleoshoreline chronology that extends over the past 100 k.y. for Lake Mega-Frome, the coalescence of Lakes Frome, Blanche, Callabonna and Gregory, in the southern latitudes of central Australia. We show that Lake Mega-Frome was connected for the last time to adjacent Lake Eyre at 50-47 ka, forming the largest remaining interconnected system of paleolakes on …
Alluvial Evidence For Major Climate And Flow Regime Changes During The Middle And Late Quaternary For Eastern Central Australia, Gerald C. Nanson, David M. Price, B. G. Jones, Jerry C. Maroulis, Maria Coleman, Hugo Bowman, Timothy J. Cohen, Tim Pietsch, Joshua R. Larsen
Alluvial Evidence For Major Climate And Flow Regime Changes During The Middle And Late Quaternary For Eastern Central Australia, Gerald C. Nanson, David M. Price, B. G. Jones, Jerry C. Maroulis, Maria Coleman, Hugo Bowman, Timothy J. Cohen, Tim Pietsch, Joshua R. Larsen
B. G. Jones
As a low-gradient arid region spanning the tropics to the temperate zone, the Lake Eyre basin has undergone gentle late Cenozoic crustal warping leading to substantial alluvial deposition, thereby forming repositories of evidence for palaeoclimatic and palaeohydrological changes from the Late Tertiary to the Holocene. Auger holes and bank exposures at five locations along the lower 500 km of Cooper Creek, a major contributor to Lake Eyre in the eastern part of the basin, yielded 85 luminescence dates (TL and OSL) that, combined wit a further 142 luminescence dates from northeastern Australia, have established a chronology of multiple episodes of …
Attachment Of Molecular Hydrogen To An Isolated Boron Cation: An Infrared And Ab Initio Study, Viktoras Dryza, Berwyck L. J Poad, Evan J. Bieske
Attachment Of Molecular Hydrogen To An Isolated Boron Cation: An Infrared And Ab Initio Study, Viktoras Dryza, Berwyck L. J Poad, Evan J. Bieske
Berwyck L. J. Poad
Structural properties of the B+−H2 electrostatic complex are investigated through its rotationally resolved infrared spectrum in the H−H stretch region (3905−3975 cm−1). The spectrum, which was obtained by monitoring B+ photofragments while the IR wavelength was scanned, is consistent with the complex having a T-shaped structure and a vibrationally averaged intermolecular separation of 2.26 Å, which decreases by 0.04 Å when the H2 subunit is vibrationally excited. The H−H stretch transition of B+−H2 is red-shifted by 220.6 ± 1.5 cm−1 from that of the free H2 molecule, much more than for other dihydrogen complexes with comparable binding energies. Properties of …
Interactions Between The Chloride Anion And Aromatic Molecules: Infrared Spectra Of The Cl-_C6h5ch3, Cl-_C6h5nh2 And Cl-_C6h5oh Complexes, Corinna Emmeluth, Berwyck L. J Poad, Christopher D. Thompson, Evan J. Bieske
Interactions Between The Chloride Anion And Aromatic Molecules: Infrared Spectra Of The Cl-_C6h5ch3, Cl-_C6h5nh2 And Cl-_C6h5oh Complexes, Corinna Emmeluth, Berwyck L. J Poad, Christopher D. Thompson, Evan J. Bieske
Berwyck L. J. Poad
The Cl-−C6H5CH3·Ar, Cl-−C6H5NH2·Ar, and Cl-−C6H5OH·Ar anion complexes are investigated using infrared photodissociation spectroscopy and ab initio calculations at the MP2/aug-cc-pVDZ level. The results indicate that for Cl-−C6H5NH2 and Cl-−C6H5OH, the Cl- anion is attached to the substituent group by a single near-linear hydrogen bond. For Cl-−C6H5CH3, the Cl- is attached to an ortho-hydrogen atom on the aromatic ring and to a hydrogen atom on the methyl group by a weaker hydrogen bond. The principal spectroscopic consequence of the hydrogen-bonding interaction in the three complexes is a red-shift and intensity increase for the CH, NH, and OH stretching modes. Complexities in …
Electron Affinities, Well Depths, And Vibrational Spectroscopy Of Cis- And Trans-Hoco, Christopher J. Johnson, Michael E. Harding, Berwyck L. J Poad, John F. Stanton, Robert E. Continetti
Electron Affinities, Well Depths, And Vibrational Spectroscopy Of Cis- And Trans-Hoco, Christopher J. Johnson, Michael E. Harding, Berwyck L. J Poad, John F. Stanton, Robert E. Continetti
Berwyck L. J. Poad
We report vibrationally resolved photoelectron spectra of internally cold HOCO– and DOCO– anions at wavelengths near and well above the detachment threshold. These spectra are dominated by a strong Franck–Condon progression of three low-energy modes of the cis isomer, the first gas-phase measurement of these vibrations. Using highly resolved, near-threshold spectra we are able to reassign the electron affinities (EAs) of cis- and trans-HOCO to 1.51 ± 0.01 and 1.37 ± 0.01 eV, respectively. Using these EAs, well depths with respect to OH + CO are determined to be 1.07 ± 0.02 eV for trans-HOCO and 0.99 ± 0.02 eV …
Rotationally Resolved Infrared Spectrum Of The Na+-D2 Complex: An Experimental And Theoretical Study, Berwyck L. Poad, V Dryza, J Klos, A A. Buchachenko, E J. Bieske
Rotationally Resolved Infrared Spectrum Of The Na+-D2 Complex: An Experimental And Theoretical Study, Berwyck L. Poad, V Dryza, J Klos, A A. Buchachenko, E J. Bieske
Berwyck L. J. Poad
The infrared spectrum of mass-selected Na+-D2 complexes is recorded in the D-D stretch vibration region (2915-2972 cm−1) by detecting Na+ photofragments resulting from photo-excitation of the complexes. Analysis of the rotationally resolved spectrum confirms a T-shaped equilibrium geometry for the complex and a vibrationally averaged intermolecular bond length of 2.461 Å. The D-D stretch band centre occurs at 2944.04 cm−1, representing a −49.6 cm−1 shift from the Q1(0) transition of the free D2 molecule. Variational rovibrational energy level calculations are performed for Na+-D2 utilising an ab initio potential energy surface developed previously for investigating the Na+-H2 complex [B. L. J. …
Photoelectron-Photofragment Coincidence Spectroscopy In A Cryogenically Cooled Linear Electrostatic Ion Beam Trap, Christopher J. Johnson, Ben B. Shen, Berwyck L. J Poad, Robert E. Continetti
Photoelectron-Photofragment Coincidence Spectroscopy In A Cryogenically Cooled Linear Electrostatic Ion Beam Trap, Christopher J. Johnson, Ben B. Shen, Berwyck L. J Poad, Robert E. Continetti
Berwyck L. J. Poad
A cryogenically cooled linear electrostatic ion beam trap for use in photoelectron-photofragment coincidence (PPC) spectroscopy is described. Using this instrument, anions created in cold, low-dutycycle sources can be stored for many seconds in a ∼20 K environment to cool radiatively, removing energetic uncertainties due to vibrationally excited precursor anions. This apparatus maintains a well-collimated beam necessary for high-resolution fragment imaging and the high experimental duty cycle needed for coincidence experiments. Ion oscillation is bunched and phase-locked to a modelocked laser, ensuring temporal overlap between ion bunches and laser pulses and that ions are intersected by the laser only when travelling …
Infrared Spectra Of Mass-Selected Mg+-H2 And Mg +-D2 Complexes, Viktoras Dryza, Berwyck L. Poad, Evan J. Bieske
Infrared Spectra Of Mass-Selected Mg+-H2 And Mg +-D2 Complexes, Viktoras Dryza, Berwyck L. Poad, Evan J. Bieske
Berwyck L. J. Poad
Rotationally resolved infrared spectra of Mg(+)-H(2) and Mg(+)-D(2) are recorded in the H-H (4025-4080 cm(-1)) and D-D (2895-2945 cm(-1)) stretch regions by monitoring Mg(+) photofragments. The nu(HH) and nu(DD) transitions of Mg(+)-H(2) and Mg(+)-D(2) are red-shifted by 106.2 +/- 1.5 and 76.0 +/- 0.1 cm(-1) respectively from the fundamental vibrational transitions of the free H(2) and D(2) molecules. The spectra are consistent with a T-shaped equilibrium structure in which the Mg(+) ion interacts with a slightly perturbed H(2) or D(2) molecule. From the spectroscopic constants, a vibrationally averaged intermolecular separation of 2.716 A (2.687 A) is deduced for the ground …
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
Berwyck L. J. Poad
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 …
Spectroscopic Study Of The Benchmark Mn+-H2 Complex, Viktoras Dryza, Berwyck L. J Poad, Evan J. Bieske
Spectroscopic Study Of The Benchmark Mn+-H2 Complex, Viktoras Dryza, Berwyck L. J Poad, Evan J. Bieske
Berwyck L. J. Poad
We have recorded the rotationally resolved infrared spectrum of the weakly bound Mn+-H2 complex in the H-H stretch region (4022-4078 cm(-1)) by monitoring Mn+ photodissociation products. The band center of Mn+-H2, the H-H stretch transition, is shifted by -111.8 cm(-1) from the transition of the free H2 molecule. The spectroscopic data suggest that the Mn+-H2 complex consists of a slightly perturbed H2 molecule attached to the Mn+ ion in a T-shaped configuration with a vibrationally averaged intermolecular separation of 2.73 A. Together with the measured Mn+...H2 binding energy of 7.9 kJ/mol (Weis, P.; et al. J. Phys. Chem. A 1997, …
Ten Trenches: A Scienceart Collaboration, Timothy J. Cohen, Martin Cohen, Stephanie Kermode, Michael G. Leggett
Ten Trenches: A Scienceart Collaboration, Timothy J. Cohen, Martin Cohen, Stephanie Kermode, Michael G. Leggett
Faculty of Science - Papers (Archive)
Collaborative and cross-disciplinary research by a group of artists and scientists in an Australian rural setting generates data and ideas that form the basis of a wider understanding of the ramifications of global warming and cooling within the local, regional and national community. The work is viewed as an initial educational platform that will allow the public to see and understand the complexities of climate-based research.