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- Faculty of Science - Papers (Archive) (26)
- Faculty of Science, Medicine and Health - Papers: part A (19)
- Faculty of Engineering and Information Sciences - Papers: Part A (12)
- Faculty of Engineering and Information Sciences - Papers: Part B (1)
- Faculty of Health and Behavioural Sciences - Papers (Archive) (1)
Articles 1 - 30 of 59
Full-Text Articles in Social and Behavioral Sciences
Analog Least Mean Square Loop For Self-Interference Cancellation: Implementation And Measurements, Anh Tuyen Le, Le Chung Tran, Xiaojing Huang, Y. Jay Guo
Analog Least Mean Square Loop For Self-Interference Cancellation: Implementation And Measurements, Anh Tuyen Le, Le Chung Tran, Xiaojing Huang, Y. Jay Guo
Faculty of Engineering and Information Sciences - Papers: Part B
Analog least mean square (ALMS) loop is a simple and efficient adaptive filter to cancel self-interference (SI) in in-band full-duplex (IBFD) radios. This paper proposes a practical structure and presents an implementation of the ALMS loop. By employing off-the-shelf components, a prototype of the ALMS loop including two taps is implemented. The prototype is evaluated in IBFD systems which have 20 MHz and 50 MHz bandwidths, respectively, with the carrier frequency of 2.4 GHz. The performance of the prototype with different roll-off factors of the transmit pulse shaping filter is also examined. Experimental results show that the ALMS loop can …
Comparisons Of The Orbiting Carbon Observatory-2 (Oco-2) XCo2 Measurements With Tccon, Debra Wunch, Paul O. Wennberg, Greg Osterman, B Fisher, Bret Naylor, Coleen M. Roehl, Christopher O'Dell, L Mandrake, C Viatte, Matthaus Kiel, David W. T Griffith, Nicholas M. Deutscher, Voltaire A. Velazco
Comparisons Of The Orbiting Carbon Observatory-2 (Oco-2) XCo2 Measurements With Tccon, Debra Wunch, Paul O. Wennberg, Greg Osterman, B Fisher, Bret Naylor, Coleen M. Roehl, Christopher O'Dell, L Mandrake, C Viatte, Matthaus Kiel, David W. T Griffith, Nicholas M. Deutscher, Voltaire A. Velazco
Faculty of Science, Medicine and Health - Papers: part A
NASA's Orbiting Carbon Observatory-2 (OCO-2) has been measuring carbon dioxide column-averaged dry-air mole fraction, XCO2, in the Earth's atmosphere for over 2 years. In this paper, we describe the comparisons between the first major release of the OCO-2 retrieval algorithm (B7r) and XCO2 from OCO-2's primary ground-based validation network: the Total Carbon Column Observing Network (TCCON). The OCO-2 XCO2 retrievals, after filtering and bias correction, agree well when aggregated around and coincident with TCCON data in nadir, glint, and target observation modes, with absolute median differences less than 0.4 ppm and RMS differences less than 1.5 …
High Intrinsic Sensitivity Etched Polymer Fiber Bragg Grating Pair For Simultaneous Strain And Temperature Measurements, Kishore Bhowmik, Gang-Ding Peng, Yanhua Luo, Eliathamby Ambikairajah, Vedran Lovric, William R. Walsh, Ginu Rajan
High Intrinsic Sensitivity Etched Polymer Fiber Bragg Grating Pair For Simultaneous Strain And Temperature Measurements, Kishore Bhowmik, Gang-Ding Peng, Yanhua Luo, Eliathamby Ambikairajah, Vedran Lovric, William R. Walsh, Ginu Rajan
Faculty of Engineering and Information Sciences - Papers: Part A
A sensing configuration for simultaneous measurement of strain and temperature with enhanced intrinsic sensitivity based on a fiber Bragg grating (FBG) pair with one grating inscribed in the etched and the other in unetched polymer fiber region is demonstrated. A poly (methyl methacrylate) based single-mode polymer fiber is etched to different diameters, and it is observed that etching can lead to change in the material properties of the fiber, such as Young's modulus and thermal expansion coefficient, which can play a vital role in improving its intrinsic sensing capabilities. Thus, exploiting the different strain and temperature sensitivities exhibited by etched …
Multi-View Indoor Scene Reconstruction From Compressed Through-Wall Radar Measurements Using A Joint Bayesian Sparse Representation, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive
Multi-View Indoor Scene Reconstruction From Compressed Through-Wall Radar Measurements Using A Joint Bayesian Sparse Representation, Van Ha Tang, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive
Faculty of Engineering and Information Sciences - Papers: Part A
This paper addresses the problem of scene reconstruction, incorporating wall-clutter mitigation, for compressed multi-view through-the-wall radar imaging. We consider the problem where the scene is sensed using different reduced sets of frequencies at different antennas. A joint Bayesian sparse recovery framework is first employed to estimate the antenna signal coefficients simultaneously, by exploiting the sparsity and correlations between antenna signals. Following joint signal coefficient estimation, a subspace projection technique is applied to segregate the target coefficients from the wall contributions. Furthermore, a multitask linear model is developed to relate the target coefficients to the scene, and a composite scene image …
Grainscan: A Low Cost, Fast Method For Grain Size And Colour Measurements, Alex P. Whan, Alison Smith, C R. Cavanagh, Jean-Philippe F. Ral, Lindsay M. Shaw, Crispin A. Howitt, Leanne Bischof
Grainscan: A Low Cost, Fast Method For Grain Size And Colour Measurements, Alex P. Whan, Alison Smith, C R. Cavanagh, Jean-Philippe F. Ral, Lindsay M. Shaw, Crispin A. Howitt, Leanne Bischof
Faculty of Engineering and Information Sciences - Papers: Part A
Background: Measuring grain characteristics is an integral component of cereal breeding and research into genetic control of seed development. Measures such as thousand grain weight are fast, but do not give an indication of variation within a sample. Other methods exist for detailed analysis of grain size, but are generally costly and very low throughput. Grain colour analysis is generally difficult to perform with accuracy, and existing methods are expensive and involved. Results: We have developed a software method to measure grain size and colour from images captured with consumer level flatbed scanners, in a robust, standardised way. The accuracy …
Field Measurements Of Trace Gases Emitted By Prescribed Fires In Southeastern Us Pine Forests Using An Open-Path Ftir System, S K. Akagi, I R. Burling, A Mendoza, T J. Johnson, M Cameron, D W. T Griffith, C Paton-Walsh, D R. Weise, J Reardon, R J. Yokelson
Field Measurements Of Trace Gases Emitted By Prescribed Fires In Southeastern Us Pine Forests Using An Open-Path Ftir System, S K. Akagi, I R. Burling, A Mendoza, T J. Johnson, M Cameron, D W. T Griffith, C Paton-Walsh, D R. Weise, J Reardon, R J. Yokelson
Faculty of Science, Medicine and Health - Papers: part A
We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, US measured during the fall of 2011. The fires were more intense than many prescribed burns because the fuels included mature pine stands not subjected to prescribed fire in decades that were lit following an extended drought. Emission factors were measured with a fixed open-path Fourier transform infrared (OP-FTIR) system that was deployed on the fire control lines. We compare these emission factors to those measured with a roving, point sampling, land-based FTIR and an airborne FTIR deployed on the same fires. We also compare to emission …
Relating Rejection Of Trace Organic Contaminants To Membrane Properties In Forward Osmosis: Measurements, Modelling And Implications, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech
Relating Rejection Of Trace Organic Contaminants To Membrane Properties In Forward Osmosis: Measurements, Modelling And Implications, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech
Faculty of Engineering and Information Sciences - Papers: Part A
This study elucidates the relationship between membrane properties and the rejection of trace organic contaminants (TrOCs) in forward osmosis (FO). An asymmetric cellulose triacetate (CTA) and a thin-film composite (TFC) polyamide FO membrane were used for this investigation. The effective average pore radius (rp), selective barrier thickness over porosity parameter (l/ε), surface charge, support layer structural parameter (S), pure water permeability coefficient (A) and salt (NaCl) permeability coefficient (B) of the two membranes were systematically characterised. Results show that measured rejection of TrOCs as a function of permeate water flux can be well described by the pore hindrance transport model. …
Impact Of Aerosol And Thin Cirrus On Retrieving And Validating Xco2 From Gosat Shortwave Infrared Measurements, S Guerlet, A Butz, D Schepers, S Basu, O Hasekamp, A Kuze, T Yokota, J.-F Blavier, N M. Deutscher, D W.T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, A Galli, I Aben
Impact Of Aerosol And Thin Cirrus On Retrieving And Validating Xco2 From Gosat Shortwave Infrared Measurements, S Guerlet, A Butz, D Schepers, S Basu, O Hasekamp, A Kuze, T Yokota, J.-F Blavier, N M. Deutscher, D W.T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, A Galli, I Aben
Faculty of Science, Medicine and Health - Papers: part A
Inadequate treatment of aerosol scattering can be a significant source of error when retrieving column-averaged dry-air mole fractions of CO2 (XCO2) from space-based measurements of backscattered solar shortwave radiation. We have developed a retrieval algorithm, RemoTeC, that retrieves three aerosol parameters (amount, size, and height) simultaneously with XCO2. Here we evaluate the ability of RemoTeC to account for light path modifications by clouds, subvisual cirrus, and aerosols when retrieving XCO2 from Greenhouse Gases Observing Satellite (GOSAT) Thermal and Near-infrared Sensor for carbon Observation (TANSO)-Fourier Transform Spectrometer (FTS) measurements. We first evaluate a cloud filter based on measurements from the Cloud …
Hox Measurements In The Summertime Upper Troposphere Over Europe: A Comparison Of Observations To A Box Model And A 3-D Model, E Regelin, H Harder, M Martinez, D Kubistin, C Tatum Ernest, H Bozem, T Klippel, Z Hosaynali-Beygi, H Fischer, R Sander, P Jockel, R Konigstedt, J Lelieveld
Hox Measurements In The Summertime Upper Troposphere Over Europe: A Comparison Of Observations To A Box Model And A 3-D Model, E Regelin, H Harder, M Martinez, D Kubistin, C Tatum Ernest, H Bozem, T Klippel, Z Hosaynali-Beygi, H Fischer, R Sander, P Jockel, R Konigstedt, J Lelieveld
Faculty of Science, Medicine and Health - Papers: part A
In situ airborne measurements of OH and HO2 with the HORUS (HydrOxyl Radical measurement Unit based on fluorescence Spectroscopy) instrument were performed in the summertime upper troposphere across Europe during the HOOVER 2 (HOx OVer EuRope) campaign in July 2007. Complementary measurements of trace gas species and photolysis frequencies were conducted to obtain a broad data set, which has been used to quantify the significant HOx sources and sinks. In this study we compare the in situ measurement of OH and HO2 with simulated mixing ratios from the constrained box model CAABA/MECCA (Chemistry As A Box Model Application/Module Efficiently Calculating …
Measurements Of Co, Hcn, And C2h6 Total Columns In Smoke Plumes Transported From The 2010 Russian Boreal Forest Fires To The Canadian High Arctic, C Viatte, K Strong, C Paton-Walsh, J Mendonca, N T. O'Neill, J R. Drummond
Measurements Of Co, Hcn, And C2h6 Total Columns In Smoke Plumes Transported From The 2010 Russian Boreal Forest Fires To The Canadian High Arctic, C Viatte, K Strong, C Paton-Walsh, J Mendonca, N T. O'Neill, J R. Drummond
Faculty of Science, Medicine and Health - Papers: part A
In August 2010, simultaneous enhancements of aerosol optical depth and total columns of carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C2H6) were observed at the Polar Environment Atmospheric Research Laboratory (PEARL, 80.05°N, −86.42°W, 0.61 km above sea level, Eureka, Nunavut, Canada). Moderate Resolution Imaging Spectroradiometer (MODIS) hot spots, Ozone Monitoring Instrument (OMI) aerosol index maps, and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectories were used to attribute these enhancements to an intense boreal fire event occurring in Russia. A ground-based Fourier Transform InfraRed (FTIR) spectrometer at PEARL provided vertically integrated measurements of trace gases transported in smoke plumes. …
Interlaboratory Study For Coral Sr/Ca And Other Element/Ca Ratio Measurements, Ed C. Hathorne, Alex Gagnon, Thomas Felis, Jess Adkins, Ryuji Asami, Wim Boer, Nicolas Caillon, David Case, Kim M. Cobb, Eric Douville, Peter Demenocal, Anton Eisenhauer, Dieter Garbe-Schonberg, Walter Geibert, Steven Goldstein, Konrad Hughen, Mayuri Inoue, Hodaka Kawahata, Martin Kolling, Florence L. Cornec, Braddock K. Linsley, Helen V. Mcgregor, Paolo Montagna, Intan S. Nurhati, Terrence M. Quinn, Jacek Raddatz, Helene Rebaubier, Laura Robinson, Aleksey Sadekov, Robert Sherrell, Dan Sinclair, Alexander W. Tudhope, Gangjian Wei, Henri Wong, Henry C. Wu, Chen-Feng You
Interlaboratory Study For Coral Sr/Ca And Other Element/Ca Ratio Measurements, Ed C. Hathorne, Alex Gagnon, Thomas Felis, Jess Adkins, Ryuji Asami, Wim Boer, Nicolas Caillon, David Case, Kim M. Cobb, Eric Douville, Peter Demenocal, Anton Eisenhauer, Dieter Garbe-Schonberg, Walter Geibert, Steven Goldstein, Konrad Hughen, Mayuri Inoue, Hodaka Kawahata, Martin Kolling, Florence L. Cornec, Braddock K. Linsley, Helen V. Mcgregor, Paolo Montagna, Intan S. Nurhati, Terrence M. Quinn, Jacek Raddatz, Helene Rebaubier, Laura Robinson, Aleksey Sadekov, Robert Sherrell, Dan Sinclair, Alexander W. Tudhope, Gangjian Wei, Henri Wong, Henry C. Wu, Chen-Feng You
Faculty of Science, Medicine and Health - Papers: part A
The Sr/Ca ratio of coral aragonite is used to reconstruct past sea surface temperature (SST). Twenty-one laboratories took part in an interlaboratory study of coral Sr/Ca measurements. Results show interlaboratory bias can be significant, and in the extreme case could result in a range in SST estimates of 7°C. However, most of the data fall within a narrower range and the Porites coral reference material JCp-1 is now characterized well enough to have a certified Sr/Ca value of 8.838 mmol/mol with an expanded uncertainty of 0.089 mmol/mol following International Association of Geoanalysts (IAG) guidelines. This uncertainty, at the 95% confidence …
Simultaneous Retrieval Of Atmospheric Co2 And Light Path Modification From Space-Based Spectroscopic Observations Of Greenhouse Gases: Methodology And Application To Gosat Measurements Over Tccon Sites, Sergey Oshchepkov, Andrey Bril, Tatsuya Yokota, Yukio Yoshida, Thomas Blumenstock, Nicholas M. Deutscher, Susanne Dohe, Ronald Macatangay, Isamu Morino, Justus Notholt, Markus Rettinger, Christof Petri, Matthias Schneider, Ralf Sussmann, Osamu Uchino, Voltaire A. Velazco, Debra Wunch, Dmitry Belikov
Simultaneous Retrieval Of Atmospheric Co2 And Light Path Modification From Space-Based Spectroscopic Observations Of Greenhouse Gases: Methodology And Application To Gosat Measurements Over Tccon Sites, Sergey Oshchepkov, Andrey Bril, Tatsuya Yokota, Yukio Yoshida, Thomas Blumenstock, Nicholas M. Deutscher, Susanne Dohe, Ronald Macatangay, Isamu Morino, Justus Notholt, Markus Rettinger, Christof Petri, Matthias Schneider, Ralf Sussmann, Osamu Uchino, Voltaire A. Velazco, Debra Wunch, Dmitry Belikov
Faculty of Science, Medicine and Health - Papers: part A
This paper presents an improved photon path length probability density function method that permits simultaneous retrievals of column-average greenhouse gas mole fractions and light path modifications through the atmosphere when processing high-resolution radiance spectra acquired from space. We primarily describe the methodology and retrieval setup and then apply them to the processing of spectra measured by the Greenhouse gases Observing SATellite (GOSAT). We have demonstrated substantial improvements of the data processing with simultaneous carbon dioxide and light path retrievals and reasonable agreement of the satellite-based retrievals against ground-based Fourier transform spectrometer measurements provided by the Total Carbon Column Observing Network …
Coupling Field And Laboratory Measurements To Estimate The Emission Factors Of Identified And Unidentified Trace Gases For Prescribed Fires, R Yokelson, I Burling, J Gilman, C Warneke, C Stockwell, J De Gouw, S Akagi, S Urbanski, P Veres, J M. Roberts, W C. Kuster, J Reardon, D W.T Griffith, T J. Johnson, S Hosseini, J W. Miller, D Cocker, H Jung, D R. Weise
Coupling Field And Laboratory Measurements To Estimate The Emission Factors Of Identified And Unidentified Trace Gases For Prescribed Fires, R Yokelson, I Burling, J Gilman, C Warneke, C Stockwell, J De Gouw, S Akagi, S Urbanski, P Veres, J M. Roberts, W C. Kuster, J Reardon, D W.T Griffith, T J. Johnson, S Hosseini, J W. Miller, D Cocker, H Jung, D R. Weise
Faculty of Science, Medicine and Health - Papers: part A
An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer …
Improved Water Vapour Spectroscopy In The 4174-4300 Cm(-1) Region And Its Impact On Sciamachy Hdo/H2o Measurements, R A. Scheepmaker, C Frankenberg, A Galli, A Butz, H Schrijver, N M. Deutscher, D Wunch, T Warneke, S Fally, I Aben
Improved Water Vapour Spectroscopy In The 4174-4300 Cm(-1) Region And Its Impact On Sciamachy Hdo/H2o Measurements, R A. Scheepmaker, C Frankenberg, A Galli, A Butz, H Schrijver, N M. Deutscher, D Wunch, T Warneke, S Fally, I Aben
Faculty of Science, Medicine and Health - Papers: part A
The relative abundance of the heavy water isotopologue HDO provides a deeper insight into the atmospheric hydrological cycle. The SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) allows for global retrievals of the ratio HDO/H2O in the 2.3 micron wavelength range. However, the spectroscopy of water lines in this region remains a large source of uncertainty for these retrievals. We therefore evaluate and improve the water spectroscopy in the range 4174-4300 cm(-1) and test if this reduces systematic uncertainties in the SCIAMACHY retrievals of HDO/H2O. We use a laboratory spectrum of water vapour to fit line intensity, air broadening and …
Organ Point Dose Measurements In Clinical Multi Slice Computed Tomography (Msct) Examinations With The Moskin™ Radiation Dosimeter, C P. L Lian, A Young, D Cutajar, N Freeman, Anatoly B. Rosenfeld
Organ Point Dose Measurements In Clinical Multi Slice Computed Tomography (Msct) Examinations With The Moskin™ Radiation Dosimeter, C P. L Lian, A Young, D Cutajar, N Freeman, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part A
This study reports on the application of the MOSkin™ dosimeter in MSCT imaging for the real-time measurement of absorbed organ point doses in a tissue-equivalent female anthropomorphic phantom. MOSkin™ dosimeters were placed within the phantom to measure absorbed point organ doses for 2 commonly applied clinical scan protocols, namely the renal calculus scan and the pulmonary embolus scan. Measured organ doses in the imaged field of view were found to be in the dose range 4.7-9.5 mGy and 16.2-27.4 mGy for the renal calculus scan and pulmonary scan protocols respectively. For the derivation of effective dose, using the more recent …
Critical Current Density: Measurements Vs. Reality, Alexey V. Pan, Igor Golovchanskiy, Sergey Fedoseev
Critical Current Density: Measurements Vs. Reality, Alexey V. Pan, Igor Golovchanskiy, Sergey Fedoseev
Faculty of Engineering and Information Sciences - Papers: Part A
Different experimental techniques are employed to evaluate the critical current density (Jc), namely transport current measurements and two different magnetisation measurements forming quasi-equilibrium and dynamic critical states. Our technique-dependent results for superconducting YBa 2Cu3O7 (YBCO) film and MgB2 bulk samples show an extremely high sensitivity of Jc and associated interpretations, such as irreversibility fields and Kramer plots, which lose meaning without a universal approach. We propose such approach for YBCO films based on their unique pinning features. This approach allows us to accurately recalculate the magnetic-field-dependent Jc obtained by any technique into the Jc behaviour, which would have been measured …
Rectifying Differences In Transport, Dynamic, And Quasi-Equilibrium Measurements Of Critical Current Density, I A. Golovchanskiy, A V. Pan, O V. Shcherbakova, S A. Fedoseev
Rectifying Differences In Transport, Dynamic, And Quasi-Equilibrium Measurements Of Critical Current Density, I A. Golovchanskiy, A V. Pan, O V. Shcherbakova, S A. Fedoseev
Faculty of Engineering and Information Sciences - Papers: Part A
The dependence of the critical current density (Jc ) on electric field criteria (E cr) is studied for high-quality YBCO (YBa2Cu3O7) thin films over the entire applied magnetic field (Ba) range. The quantitative model describing the Jc(Ba) dependence is compared and explained for the critical current densities obtained by different measurement techniques. Transport current and quasi-equilibrium magnetization measurement data can successfully be fitted by the model with appropriate electric field criteria. The dependence of the irreversibility field on the E cr criterion can be obtained within …
Measurements Of Reactive Trace Gases And Variable O3 Formation Rates In Some South Carolina Biomass Burning Plumes, S K. Akagi, Robert J. Yokelson, I R. Burling, S Meinardi, I Simpson, D R. Blake, G R. Mcmeeking, A Sullivan, T Lee, S Kreidenweis, S Urbanski, J Reardon, D W.T Griffith, T J. Johnson, D R. Weise
Measurements Of Reactive Trace Gases And Variable O3 Formation Rates In Some South Carolina Biomass Burning Plumes, S K. Akagi, Robert J. Yokelson, I R. Burling, S Meinardi, I Simpson, D R. Blake, G R. Mcmeeking, A Sullivan, T Lee, S Kreidenweis, S Urbanski, J Reardon, D W.T Griffith, T J. Johnson, D R. Weise
Faculty of Science, Medicine and Health - Papers: part A
In October–November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with …
Some Influences On Wall Friction Measurements - A Preliminary Investigation, Wendy Halford, Cameron Lawler, Andrew P. Grima, Peter C. Arnold
Some Influences On Wall Friction Measurements - A Preliminary Investigation, Wendy Halford, Cameron Lawler, Andrew P. Grima, Peter C. Arnold
Faculty of Engineering and Information Sciences - Papers: Part A
The concept of measuring the friction between a bulk solid and a wall material is very simple. However, experience together with previous wall friction measurement research suggest that variables that influence wall friction values are difficult to quantify and, so far, are proving unreliable to predict with any degree of confidence. In this paper some preliminary test results are presented for different bulk solids on different wall plates where variables examined include particle size distribution, moisture content, test cell size and shear speed. The outcomes presented confirm the authors' belief that with the present state of knowledge about wall friction …
Ch4, Co, And H2o Spectroscopy For The Sentinel-5 Precursor Mission: An Assessment With The Total Carbon Column Observing Network Measurements, A Galli, A Butz, R A. Scheepmaker, O Hasekamp, J Landgraf, P Tol, D Wunch, N M. Deutscher, G C. Toon, P O. Wennberg, D W. T Griffith, I Aben
Ch4, Co, And H2o Spectroscopy For The Sentinel-5 Precursor Mission: An Assessment With The Total Carbon Column Observing Network Measurements, A Galli, A Butz, R A. Scheepmaker, O Hasekamp, J Landgraf, P Tol, D Wunch, N M. Deutscher, G C. Toon, P O. Wennberg, D W. T Griffith, I Aben
Faculty of Science - Papers (Archive)
The TROPOspheric Monitoring Instrument (TROPOMI) will be part of ESA’s Sentinel-5 Precursor (S5P) satellite platform scheduled for launch in 2015. TROPOMI will monitor methane and carbon monoxide concentrations in the Earth’s atmosphere by measuring spectra of back-scattered sunlight in the short-wave infrared (SWIR).
Atmospheric Greenhouse Gases Retrieved From Sciamachy: Comparison To Ground-Based Fts Measurements And Model Results, O Schneising, P Bergamaschi, H Bovensmann, M Buchwitz, J P. Burrows, N M. Deutscher, D W. T Griffith, J Heymann, R Macatangay, J Messerschmidt, J Notholt, M Rettinger, M Reuter, R Sussmann, Voltaire A. Velazco, T Warneke, P O. Wennberg, D Wunch
Atmospheric Greenhouse Gases Retrieved From Sciamachy: Comparison To Ground-Based Fts Measurements And Model Results, O Schneising, P Bergamaschi, H Bovensmann, M Buchwitz, J P. Burrows, N M. Deutscher, D W. T Griffith, J Heymann, R Macatangay, J Messerschmidt, J Notholt, M Rettinger, M Reuter, R Sussmann, Voltaire A. Velazco, T Warneke, P O. Wennberg, D Wunch
Faculty of Science - Papers (Archive)
SCIAMACHY onboard ENVISAT (launched in 2002) enables the retrieval of global long-term columnaveraged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO2 and XCH4). In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS) measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON) sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability …
Self-Mixing Interferometry Used For Instrumentations And Measurements(Invited), Silvano Donati, Zhao Wang, Yanguang Yu
Self-Mixing Interferometry Used For Instrumentations And Measurements(Invited), Silvano Donati, Zhao Wang, Yanguang Yu
Faculty of Engineering and Information Sciences - Papers: Part A
This paper reviews the development of a new configuration of interferometry, Self-mixing Interferometry(SMI). SMI is attractive because it doesn't require any optical part external to the laser and can be employed in a variety of measurements, ranging from the traditional measurements related to optical path length like displacements, small-amplitude vibrations, velocity; to sensing of weak optical echoes, like return loss and isolation factor measurements; and also to a special feature for the interaction with the medium, measurements of physical parameters, like laser line width, coherence length, and the alfa factor. Because it is also a coherent detection scheme, the SMI …
Methane Retrievals From Greenhouse Gases Observing Satellite (Gosat) Shortwave Infrared Measurements: Performance Comparison Of Proxy And Physics Retrieval Algorithms, D Schepers, S Guerlet, A Butz, J Landgraf, C Frankenberg, O Hasekamp, J-F Blavier, N M. Deutscher, D W. T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, I Aben
Methane Retrievals From Greenhouse Gases Observing Satellite (Gosat) Shortwave Infrared Measurements: Performance Comparison Of Proxy And Physics Retrieval Algorithms, D Schepers, S Guerlet, A Butz, J Landgraf, C Frankenberg, O Hasekamp, J-F Blavier, N M. Deutscher, D W. T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, I Aben
Faculty of Science - Papers (Archive)
We compare two conceptually different methods for determining methane column-averaged mixing ratios (XCH4) from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared (SWIR) measurements. These methods account differently for light scattering by aerosol and cirrus. The proxy method retrieves a CO2 column which, in conjunction with prior knowledge on CO2 acts as a proxy for scattering effects. The physics-based method accounts for scattering by retrieving three effective parameters of a scattering layer. Both retrievals are validated on a 19-month data set using ground-based XCH4 measurements at 12 stations of the Total Carbon Column Observing Network (TCCON), …
Retrieval Of Atmospheric Co2 With Enhanced Accuracy And Precision From Sciamachy: Validation With Fts Measurements And Comparison With Model Results, M Reuter, H Bovensmann, M Buchwitz, Jp Burrows, B Connor, Nicholas M. Deutscher, David W. Griffith, J Heymann, Gretchen Keppel-Aleks, Janina Messerschmidt, Justus Notholt, Christof Petri, J Robinson, O Schneising, V Sherlock, Voltaire A. Velazco, Thorsten Warneke, Paul O. Wennberg, Debra Wunch
Retrieval Of Atmospheric Co2 With Enhanced Accuracy And Precision From Sciamachy: Validation With Fts Measurements And Comparison With Model Results, M Reuter, H Bovensmann, M Buchwitz, Jp Burrows, B Connor, Nicholas M. Deutscher, David W. Griffith, J Heymann, Gretchen Keppel-Aleks, Janina Messerschmidt, Justus Notholt, Christof Petri, J Robinson, O Schneising, V Sherlock, Voltaire A. Velazco, Thorsten Warneke, Paul O. Wennberg, Debra Wunch
Faculty of Science - Papers (Archive)
The Bremen Optimal Estimation differential optical absorption spectroscopy (DOAS) (BESD) algorithm for satellite based retrievals of XCO 2 (the column-average dry-air mole fraction of atmospheric CO 2) has been applied to Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) data. It uses measurements in the O 2-A absorption band to correct for scattering of undetected clouds and aerosols. Comparisons with precise and accurate ground-based Fourier transform spectrometer (FTS) measurements at four Total Carbon Column Observing Network (TCCON) sites have been used to quantify the quality of the new SCIAMACHY XCO 2 data set. Additionally, the results have been compared to …
The Australian Methane Budget: Interpreting Surface And Train-Borne Measurements Using A Chemistry Transport Model, A Fraser, C C. Miller, Paul Palmer, Nicholas M. Deutscher, Nicholas B. Jones, David W. Griffith
The Australian Methane Budget: Interpreting Surface And Train-Borne Measurements Using A Chemistry Transport Model, A Fraser, C C. Miller, Paul Palmer, Nicholas M. Deutscher, Nicholas B. Jones, David W. Griffith
Faculty of Science - Papers (Archive)
We investigate the Australian methane budget from 2005-2008 using the GEOS-Chem 3D chemistry transport model, focusing on the relative contribution of emissions from different sectors and the influence of long-range transport. To evaluate the model, we use in situ surface measurements of methane, methane dry air column average (XCH 4) from ground-based Fourier transform spectrometers (FTSs), and train-borne surface concentration measurements from an in situ FTS along the north-south continental transect. We use gravity anomaly data from Gravity Recovery and Climate Experiment to describe the spatial and temporal distribution of wetland emissions and scale it to a prior emission estimate, …
Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise
Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise
Faculty of Science - Papers (Archive)
We have measured emission factors for 19 tracegas species and particulate matter (PM2.5) from 14 prescribedfires in chaparral and oak savanna in the southwesternUS, as well as conifer forest understory in the southeasternUS and Sierra Nevada mountains of California. These arelikely the most extensive emission factor field measurementsfor temperate biomass burning to date and the only publishedemission factors for temperate oak savanna fuels. This studyhelps to close the gap in emissions data available for temperatezone fires relative to tropical biomass burning. Wepresent the first field measurements of the biomass burningemissions of glycolaldehyde, a possible precursor for aqueousphase secondary organic aerosol …
Global Co(2) Fluxes Inferred From Surface Air-Sample Measurements And From Tccon Retrievals Of The Co(2) Total Column, Frederic Chevallier, Nicholas M. Deutscher, T J. Conway, P Ciais, L Ciattaglia, S Dohe, M Frohlich, A J. Gomez-Pelaez, David W. Griffith, F Hase, L Haszpra, Paul Krummel, E Kyro, C Labuschagne, R Lagenfelds, T Machidda, F Maignan, H Matsueda, I Morino, Justus Notholt, M Ramonet, Y Sawa, M Schmidt, V Sherlock, P Steele, K Strong, R Sussmann, Paul O. Wennberg, Steven C. Wofsy, D Worthy, Debra Wunch, M Zimnoch
Global Co(2) Fluxes Inferred From Surface Air-Sample Measurements And From Tccon Retrievals Of The Co(2) Total Column, Frederic Chevallier, Nicholas M. Deutscher, T J. Conway, P Ciais, L Ciattaglia, S Dohe, M Frohlich, A J. Gomez-Pelaez, David W. Griffith, F Hase, L Haszpra, Paul Krummel, E Kyro, C Labuschagne, R Lagenfelds, T Machidda, F Maignan, H Matsueda, I Morino, Justus Notholt, M Ramonet, Y Sawa, M Schmidt, V Sherlock, P Steele, K Strong, R Sussmann, Paul O. Wennberg, Steven C. Wofsy, D Worthy, Debra Wunch, M Zimnoch
Faculty of Science - Papers (Archive)
"We present the first estimate of the global distribution of CO(2) surface fluxes from 14 stations of the Total Carbon Column Observing Network (TCCON). The evaluation of this inversion is based on 1) comparison with the fluxes from a classical inversion of surface air-sample-measurements, and 2) comparison of CO(2) mixing ratios calculated from the inverted fluxes with independent aircraft measurements made during the two years analyzed here, 2009 and 2010. The former test shows similar seasonal cycles in the northern hemisphere and consistent regional carbon budgets between inversions from the two datasets, even though the TCCON inversion appears to be …
Infrared Stimulated Luminescence Measurements Of Single Grains Of K-Rich Feldspar For Isochron Dating, Bo Li, Sheng-Hua Li, Geoffrey A. T Duller, Ann G. Wintle
Infrared Stimulated Luminescence Measurements Of Single Grains Of K-Rich Feldspar For Isochron Dating, Bo Li, Sheng-Hua Li, Geoffrey A. T Duller, Ann G. Wintle
Faculty of Science, Medicine and Health - Papers: part A
This paper explores the use of single grain luminescence measurements in isochron dating of K-rich feldspars. The thermal stability of individual feldspar grains was investigated using pulse annealing methods, which appears to distinguish between K-rich and Na-rich feldspars. A good isochron fit was obtained using synthetic aliquots produced from the single grain data set and the age obtained based on an assumed K content of 13 ± 1% was in good agreement with that obtained using single aliquot measurements (and with other age control).
Anomalous Fading: A Reply To The Comment By Huntley On "Isochron Measurements Of Naturally Irradiated K-Feldspar Grains", Bo Li, Sheng-Hua Li, Ann G. Wintle, Hui Zhao
Anomalous Fading: A Reply To The Comment By Huntley On "Isochron Measurements Of Naturally Irradiated K-Feldspar Grains", Bo Li, Sheng-Hua Li, Ann G. Wintle, Hui Zhao
Faculty of Science, Medicine and Health - Papers: part A
We are pleased that Huntley (this issue) has put forward another explanation for the data that we obtained when we measured the equivalent doses (De) of potassium (K) feldspar grains of different diameters using their infrared stimulated luminescence (IRSL) signals (Li et al., 2007). We also measured the fading rates for the IRSL signals from grains of different size and concluded that the fading rates were independent of grain size. Huntley is concerned that the fading rates (g-values) that we obtained had relatively large errors and that these could have masked any minor differences in the g-values; a small systematic …
Quantitative Characterization Of Emissions From Biomass Burning Using Remote Sensing Measurements, Clare Paton-Walsh, Emma Young, David Griffith
Quantitative Characterization Of Emissions From Biomass Burning Using Remote Sensing Measurements, Clare Paton-Walsh, Emma Young, David Griffith
Faculty of Science, Medicine and Health - Papers: part A
We present a new method for deriving total emissions estimates from large vegetation fires using satellite-based measurements of aerosol optical depth. This method is based upon simultaneous measurements of total column amounts of trace gases and aerosol optical depth of the atmosphere through smoke plumes from Australian fires. These measurements were derived from ground-based solar remote sensing spectrometers in the infrared and UV-visible spectral regions and also provide emission ratios that may be used in more conventional bottom-up estimates of total emissions. Measurements of emissions from Australian forest fires are relatively sparse given the significance of this source to the …