Physical Sciences and Mathematics Commons^™

Slides: Long-Term Augmentation Of The Water Supply Of The Colorado River System, Les Lampe

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Les Lampe, Colorado River Water Consultants, Las Vegas, Nevada

29 slides

A Study Of Carbon Features In Type Ia Supernova Spectra, Jerod T. Parrent, R. C. Thomas, Robert A. Fesen, G. H. Marion

Dartmouth Scholarship

One of the major differences between various explosion scenarios of Type Ia supernovae (SNe Ia) is the remaining amount of unburned (C+O) material and its velocity distribution within the expanding ejecta. While oxygen absorption features are not uncommon in the spectra of SNe Ia before maximum light, the presence of strong carbon absorption has been reported only in a minority of objects, typically during the pre-maximum phase. The reported low frequency of carbon detections may be due to low signal-to-noise data, low abundance of unburned material, line blending between C II 6580 and Si II 6355, ejecta temperature differences, asymmetrical …

Crop Updates 2011 - Farming Systems, Janette Drew, Rob Grima, Bob French, Raj Malik, Mark Seymour, Christine Zaicou-Kunesch, Glenn Mcdonald, Brendon Nicholas, Dennis Van Gool, James Fisher, Peter Tozer, Doug Abrecht, Michael Robertson, Cameron Weeks, Michael O'Conner, Peter Newman, Mike Clarke, Andrew Blake, Gordon Macaulay, Vijay Jayasena, Syed M. Nasar-Abbas, Larisa Cato, Robert Loughman, Ken Quail

Crop Updates

This session covers twelve papers from different authors:

1. Fallowing 50% of the farm each year – does it pay? Janette Drew and Rob Grima

Department of Agriculture and Food

2. How crop sequences affect the productivity and resilience of cropping systems in two Western Australian environments, Bob French, Raj Malik, Mark Seymour, Department of Agriculture and Food

3. When is continuous wheat or barley sustainable? Christine Zaicou-Kunesch and Rob Grima Department of Agriculture and Food

4. Identifying constraints to bridging the yield gap, Glenn McDonald, Department of Agriculture and Food

5. Land constraints limiting wheat yields in …

Forest Structure And Aboveground Biomass In The Southwestern United States From Modis And Misr, Mark Chopping, Crystal B. Schaaf, Feng Zhao, Anne W. Nolin, Gretchen G. Moisen, John V. Martonchik, Michael Bull

United States National Aeronautics and Space Administration: Publications

Red band bidirectional reflectance factor data from the NASA MODerate resolution Imaging Spectroradiometer (MODIS) acquired over the southwestern United States were interpreted through a simple geometric–optical (GO) canopy reflectance model to provide maps of fractional crown cover (dimensionless), mean canopy height (m), and aboveground woody biomass (Mg ha⁻¹) on a 250 m grid. Model adjustment was performed after dynamic injection of a background contribution predicted via the kernel weights of a bidirectional reflectance distribution function (BRDF) model. Accuracy was assessed with respect to similar maps obtained with data from the NASA Multiangle Imaging Spectroradiometer (MISR) and to contemporaneous …

Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana

Faculty of Informatics - Papers (Archive)

The discovery of carbon nanostructures, such as graphene and carbon nanotubes, has led to the creation of many novel nano-devices. In this paper, we consider an environmental application of carbon nanostructures for filtering and adsorbing polycyclic aromatic hydrocarbons (PAHs) which are environmental pollutants. We mathematically investigate the adsorption of PAHs onto a graphene sheet and determine the underlying mechanisms of suction of PAHs into a carbon nanotube. We adopt a continuum approach together with the semi-empirical Lennard-Jones potential to determine van der Waals interaction forces and energies. Results obtained here for certain PAHs are well in agreement with existing experimental …

Carbon Credits, Mary Finley-Brook, Curtis Thomas

Geography and the Environment Faculty Publications

A carbon credit is an allowance or offset equal to one metric ton of carbon dioxide (C02) or other greenhouse gas (GHG) equivalent calculated in tons of C02. Carbon markets allow individuals, companies, or states to finance emissions reductions in other locations, for example, through projects that create or promote renewable energy, energy efficiency, or reforestation, as a means to lower their own carbon footprint. Trade of carbon credits within compliance and voluntary markets is a multibillion-dollar enterprise that makes up a cornerstone of international efforts to combat climate change. Buying and selling emissions allowances often means that mitigation can …

Compact-Designed Supercapacitors Using Free-Standing Single-Walled Carbon Nanotube Films, Zhiqiang Niu, Weiya Zhou, Jun Chen, Guoxing Feng, Hong Li, Wenjun Ma, Jinzhu Li, Haibo Dong, Yan Ren, Duan Zhao, Sishen Xie

Australian Institute for Innovative Materials - Papers

We reported the realization of assembling compact-designed supercapacitors using large-scaled freestanding and flexible single-walled carbon nanotube (SWCNT) films as both anode and cathode. A prototype of the processing procedures was developed to obtain the uniform spreading of the SWCNT films onto the separators serving as both electrodes and charge collectors without metallic current collectors, leading to a simplified and lightweight architecture. The area of SWCNT film on a separator can be scaled up and its thickness can be extended. High energy and power densities (43.7 Wh kg^-1 and 197.3 kW kg^-1, respectively) were achieved from the prepared …

Show Us Your (Carbon Nanotube Artificial) Muscles!, Geoffrey M. Spinks

Australian Institute for Innovative Materials - Papers

The idea of doctors deploying miniscule robots in your body to diagnose and treat medical conditions is closer to reality today with the development of artificial muscles small and strong enough to push such tiny "nano-bots" along.

Sources Of Carbonaceous Aerosols And Deposited Black Carbon In The Arctic In Winter-Spring: Implications For Radiative Forcing, Q Wang, D J. Jacob, J A. Fisher, J Mao, E M. Leibensperger, C C. Carouge, P Le Sager, Y Kondo, J L. Jimenez, M J. Cubison, S J. Doherty

Faculty of Science - Papers (Archive)

We use a global chemical transport model (GEOS-Chem CTM) to interpret observations of black carbon (BC) and organic aerosol (OA) from the NASA ARCTAS aircraft campaign over the North American Arctic in April 2008, as well as longer-term records in surface air and in snow (2007-2009). BC emission inventories for North America, Europe, and Asia in the model are tested by comparison with surface air observations over these source regions. Russian open fires were the dominant source of OA in the Arctic troposphere during ARCTAS but we find that BC was of prevailingly anthropogenic (fossil fuel and biofuel) origin, particularly …

The Influence Of Sediment Particle Size And Organic Carbon On Toxicity Of Copper To Benthic Invertebrates In Oxic/Suboxic Surface Sediments, David Strom, Stuart L. Simpson, Graeme E. Batley, Dianne F. Jolley

Faculty of Science - Papers (Archive)

The use of sediment quality guidelines to predict the toxicity of metals in sediments is limited by an inadequate understanding of exposure pathways and by poor causal links between exposure and effects. For a 10-d exposure to Cu-spiked sediments, toxicity to the amphipod Melita plumulosa was demonstrated to occur through a combination of dissolved and dietary Cu exposure pathways, but for the bivalves Spisula trigonella and Tellina deltoidalis, toxicity occurred primarily by exposure to dissolved Cu. For relatively oxidized sediments that had moderate amounts of organic carbon (2.6-8.3% OC), silt (20-100%

Daily And 3-Hourly Variability In Global Fire Emissions And Consequences For Atmospheric Model Predictions Of Carbon Monoxide, M Mu, James Randerson, G R. Van Der Werf, L Giglio, Prasad Kasibhatla, D Morton, G J. Collatz, R S. Defries, E J. Hyer, E M. Prins, David W. Griffith, Debra Wunch, G C. Toon, V Sherlock, Paul O. Wennberg

Faculty of Science - Papers (Archive)

"Attribution of the causes of atmospheric trace gas and aerosol variability often requires the use of high resolution time series of anthropogenic and natural emissions inventories. Here we developed an approach for representing synoptic-and diurnal-scale temporal variability in fire emissions for the Global Fire Emissions Database version 3 (GFED3). We disaggregated monthly GFED3 emissions during 2003-2009 to a daily time step using Moderate Resolution Imaging Spectroradiometer (MODIS)-derived measurements of active fires from Terra and Aqua satellites. In parallel, mean diurnal cycles were constructed from Geostationary Operational Environmental Satellite (GOES) Wildfire Automated Biomass Burning Algorithm (WF_ABBA) active fire observations. Daily variability …

Preliminary Validation Of Column-Averaged Volume Mixing Ratios Of Carbon Dioxide And Methane Retrieved From Gosat Short-Wavelength Infrared Spectra, David W. Griffith, G C. Toon, B Connor, R Sussmann, Thorsten Warneke, Nicholas M. Deutscher, Paul O. Wennberg, Justus Notholt, V Sherlock, J Robinson, O Uchino, C M. Roehl, I Morino, Debra Wunch, Janina Messerschmidt, Y Yoshida, M Inoue, M Rettinger

Faculty of Science - Papers (Archive)

Column-averaged volume mixing ratios of carbon dioxide and methane retrieved from the Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed observation (GOSAT SWIR XCO2 and XCH4 ) were compared with the reference calibrated data obtained by ground-based high-resolution Fourier Transform Spectrometers (g-b FTSs) participating in the Total Carbon Column Observing Network (TCCON). Preliminary results are as follows: the GOSAT SWIR XCO2 and XCH4 (Version 01.xx) are biased low by 8.85 ±4.75 ppm (2.3±1.2 %) and 20.4±18.9 ppb (1.2±1.1 %), respectively. The standard deviation of the GOSAT SWIR XCO2 and XCH4 is about 1% after correcting the negative biases of XCO2 and …

Preparation And Characterisation Of Conducting Biopolymer-Carbon Nanotube Composite Materials, Ali Aldalbahi, Marc In Het Panhuis

Faculty of Science - Papers (Archive)

In this work, kappa-carrageenan (KC) is used to prepare composite dispersions consisting of single-walled (SWNTs) and multi-walled (MWNTs) carbon nanotubes. Free-standing composite films were prepared by evaporative casting and vacuum filtration of these dispersions.