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Michigan Technological University

Michigan Tech Publications

2013

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li Dec 2013

Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li

Michigan Tech Publications

In situ measurements of carbon monoxide (CO) and ozone (O3) at the Pico Mountain Observatory (PMO) located in the Azores, Portugal, are analyzed together with results from an atmospheric chemical transport model (GEOS-Chem) and satellite remote sensing data (AIRS (Atmospheric Infrared Sounder) for CO, and TES (Tropospheric Emission Spectrometer) for O3) to examine the evolution of free-troposphere CO and O3 over the North Atlantic for 2001-2011. GEOS-Chem captured the seasonal cycles for CO and O3 well but significantly underestimated the mixing ratios of CO, particularly in spring. Statistically significant (using a significance level of 0.05) decreasing trends were found for …

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Performances Evaluation Of Cecabase® Rt In Warm Mix Asphalt Technology, Shu Wei Goh, Mohd Rosli Mohd Hasan, Zhanping You Nov 2013

Performances Evaluation Of Cecabase® Rt In Warm Mix Asphalt Technology, Shu Wei Goh, Mohd Rosli Mohd Hasan, Zhanping You

Michigan Tech Publications

The purpose of this study was to evaluate the performance of warm mix asphalt (WMA) mixtures containing different percentages of Cecabase® RT using dynamic modulus (|E*|), tensile strength ratio (TSR), four point beam fatigue, flow number and asphalt pavement analyzer (APA) rutting tests. In this study, 0.2%, 0.35% and 0.5% Cecabase® RT were incorporated in the 5E3 Superpave mixtures prepared at three different temperatures, 100 °C, 115 °C and 130 °C. A Hot Mix Asphalt (HMA) mixture was used as the control mixture. All the mixture samples were prepared using PG 58-34 binder and compacted at 86 gyrations under different …

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Rheological Evaluation Of Foamed Wma Modified With Nano Hydrated Lime, Aboelkasim Diab, Zhanping You, Hainian Wang Nov 2013

Rheological Evaluation Of Foamed Wma Modified With Nano Hydrated Lime, Aboelkasim Diab, Zhanping You, Hainian Wang

Michigan Tech Publications

Although the Warm Mix Asphalt (WMA) is gaining popularity very rapidly and becoming a mainstream technique for producing asphalt mixtures, there are many concerns regarding its long-term performance. Over the years, the Regular Hydrated Lime (RHL) has gained considerable recognition as a common additive to bituminous pavements. However, the Nano Hydrated Lime (NHL) (particle sizes 100 nanometer (nm) or less) has not been used as an additive to the asphalt mixtures before. The rheology properties of foamed WMA were studied since the pavement performance is primarily controlled by the rheological properties of asphalt cement. NHL materials with particle sizes of …

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Optimal Via Placement In Under Filled Embedded Multimode Waveguides, Nicholas J. Riegel, Matthew Howard, Christopher Middlebrook Sep 2013

Optimal Via Placement In Under Filled Embedded Multimode Waveguides, Nicholas J. Riegel, Matthew Howard, Christopher Middlebrook

Michigan Tech Publications

The self-imaging property of multimode waveguides creates a challenging problem when finding the optimal placement position of an out-of-plane coupler for embedded waveguides. This problem is compounded when the waveguides are coupled using a small input such as a vertical cavity surface emitting laser (VCSEL) or a single mode fiber where only some of the modes are generated. When the waveguide system is under filled, the coupling efficiency for the optical vertical interconnect assembly (VIA) can vary by as much as 6.2 dB depending on the length of the proceeding waveguide due to different output fields from the self-imaging property. …

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Projected Effect Of 2000-2050 Changes In Climate And Emissions On Aerosol Levels In China And Associated Transboundary Transport, H. Jiang, H. Liao, H. O.T. Pye, S. Wu, L. J. Mickley, J. H. Seinfeld, X. Y. Zhang Sep 2013

Projected Effect Of 2000-2050 Changes In Climate And Emissions On Aerosol Levels In China And Associated Transboundary Transport, H. Jiang, H. Liao, H. O.T. Pye, S. Wu, L. J. Mickley, J. H. Seinfeld, X. Y. Zhang

Michigan Tech Publications

We investigate projected 2000-2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × 5° resolution. Future changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together through sensitivity simulations. Accounting for sulfate, nitrate, ammonium, black carbon (BC), and organic carbon (OC) aerosols, concentrations of individual aerosol species change by -1.5 to +0.8 μg m-3, and PM2.5 levels are projected to change by about 10-20% in eastern …

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Reconstruction Of Long Horizontal-Path Images Under Anisoplanatic Conditions Using Multiframe Blind Deconvolution, Glen E. Archer, Jeremy P. Bos, Michael Roggemann Aug 2013

Reconstruction Of Long Horizontal-Path Images Under Anisoplanatic Conditions Using Multiframe Blind Deconvolution, Glen E. Archer, Jeremy P. Bos, Michael Roggemann

Michigan Tech Publications

All optical systems that operate in or through the atmosphere suffer from turbulence induced image blur. Both military and civilian surveillance, gun sighting, and target identification systems are interested in terrestrial imaging over very long horizontal paths, but atmospheric turbulence can blur the resulting images beyond usefulness. This work explores the mean square error (MSE) performance of a multiframe blind deconvolution (MFBD) technique applied under anisoplanatic conditions for both Gaussian and Poisson noise model assumptions. The technique is evaluated for use in reconstructing images of scenes corrupted by turbulence in long horizontal-path imaging scenarios. Performance is evaluated via the reconstruction …

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Impact Of Aging Mechanism On Model Simulated Carbonaceous Aerosols, Y. Huang, S. Wu, M. K. Dubey, N. H.F. French Aug 2013

Impact Of Aging Mechanism On Model Simulated Carbonaceous Aerosols, Y. Huang, S. Wu, M. K. Dubey, N. H.F. French

Michigan Tech Publications

Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport models, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed aging scheme for carbonaceous aerosols in a chemical transport model (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and …

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Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al. Jul 2013

Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al.

Michigan Tech Publications

We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned …

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Modeling Of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation Of Omi So < Inf> 2 Plume Height Data And Comparison With Modis And Caliop Observations, J. Wang, S. Park, J. Zeng, C. Ge, K. Yang, S. Carn, N. Krotkov, A. H. Omar Feb 2013

Modeling Of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation Of Omi So < Inf> 2 Plume Height Data And Comparison With Modis And Caliop Observations, J. Wang, S. Park, J. Zeng, C. Ge, K. Yang, S. Carn, N. Krotkov, A. H. Omar

Michigan Tech Publications

Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI) with the Extended Iterative Spectral Fitting (EISF) technique are used to initialize a global chemistry transport model (GEOS-Chem) to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a) good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate …

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Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte Feb 2013

Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte

Michigan Tech Publications

The 2008 Chaitén Volcano eruption began on 2 May 2008 with an explosive phase that injected large amounts of tephra into the atmosphere. During the first week of the eruption, volcanic ash clouds were transported for hundreds of kilometres over Argentina by the prevailing westerly winds. Tephra deposition extended to the Atlantic Ocean and severely affected the Argentinean Patagonia. Impacts included air and water quality degradation, disruption of ground transportation systems and cancellation of flights at airports more than 1,500 km apart. We use the FALL3D tephra transport model coupled with the Weather Research and Forecasting-Advanced Research Weather (WRF-ARW) meteorological …

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