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Full-Text Articles in Engineering

Tracking Trucks To Improve Performance, Mecit Cetin, Christopher M. Monsere Mar 2013

Tracking Trucks To Improve Performance, Mecit Cetin, Christopher M. Monsere

TREC Project Briefs

Freight transportation is an important part of Oregon’s economy, and the Oregon Department of Transportation, or ODOT, continually observes the highway system to make sure it is running as smoothly as possible. By monitoring the progress of individual trucks, ODOT can obtain performance metrics such as travel time, travel delays, and origin-destination flows. This information can help identify slow passages or bottlenecks in the highway system. Typical ways of obtaining these metrics, however, may involve purchasing expensive equipment, and may also raise privacy concerns if each truck is required to carry a tracking unit. To avoid these difficulties, Portland State …


Fast And Frugal Heuristics For New Product Screening - Is Managerial Judgment "Good Enough?", Antonie J. Jetter, Fatima M. Albar Mar 2013

Fast And Frugal Heuristics For New Product Screening - Is Managerial Judgment "Good Enough?", Antonie J. Jetter, Fatima M. Albar

Engineering and Technology Management Faculty Publications and Presentations

Project screening in the fuzzy front-end of product development is dominantly based on managerial judgment, yet little is known about the quality of heuristic screening decisions. This research models three commonly discussed fast and frugal (F&F)heuristics for project screening (take-the-best, tallying and elimination-by-aspect) and explores their performance. An illustrative dataset of 52 new product development projects is used to compare the performance of F&F heuristics against that of regression models, which reflect compensatory judgment behaviour. The findings uncover a 'less is more' effect that justifies the use of simple heuristics in early stage product screening; two out of the three …


Protecting Bridges From Earthquake Damage, Peter Dusicka Mar 2013

Protecting Bridges From Earthquake Damage, Peter Dusicka

TREC Project Briefs

Earthquake damage to bridges can have serious effects on a transportation network. When a bridge is out, the damage can go well beyond what is immediately visible: in addition to the cost of repairing it, the state must deal with short-term and long-term interruptions to traffic. These interruptions can delay repair and construction, as well as impacting post earthquake emergency response and causing the loss of valuable time for commuters and freight. To prevent this situation, older bridges (ones that are past an average construction life of about 50 years) should be retrofitted with stronger materials, especially in earthquake- prone …


Reliable Travel: Clearer Roads, Cleaner Air, Miguel Figliozzi Mar 2013

Reliable Travel: Clearer Roads, Cleaner Air, Miguel Figliozzi

TREC Project Briefs

A project explores the importance of travel-time reliability for evaluating the performance of a road network in terms of emissions, traffic and commuters’ route choices.


An In Situ Experimental Study Of Grain Growth In A Nanocrystalline Fe91ni8zr1 Alloy, Hasan Kotan, Kris A. Darling, Mostafa Saber, Ronald O. Scattergood, Carl C. Koch Mar 2013

An In Situ Experimental Study Of Grain Growth In A Nanocrystalline Fe91ni8zr1 Alloy, Hasan Kotan, Kris A. Darling, Mostafa Saber, Ronald O. Scattergood, Carl C. Koch

Mechanical and Materials Engineering Faculty Publications and Presentations

Grain growth and microstructural evolution of thermally stabilized Fe91Ni8Zr1 were investigated by in situ and ex situ studies. Our investigations suggest that the microstructural evolution is fairly slow and the microstructure shows stabilization up to about 700 °C. Above this temperature, a certain fraction of grains grow abnormally into the nanocrystalline matrix, resulting in a bimodal microstructure and causing the complete loss of thermal stability. The reason for abnormal grain growth and the loss of thermal stability is identified as the appearance of the fcc γ-phase and consequent reduction in the total area of grain boundaries and the overall stored …


Adaptation Of Classical Tidal Harmonic Analysis To Nonstationary Tides, With Application To River Tides, Pascal Matte, David A. Jay, Edward D. Zaron Mar 2013

Adaptation Of Classical Tidal Harmonic Analysis To Nonstationary Tides, With Application To River Tides, Pascal Matte, David A. Jay, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis tool has been developed, NS_TIDE, adapted to the study of nonstationary signals, in this case, river tides. It builds the nonstationary forcing directly into the tidal basis functions. It is implemented by modification of T_TIDE; however, certain concepts, particularly the meaning of a constituent and the Rayleigh criterion, are redefined to account for the smearing effects on the tidal spectral lines by nontidal energy. An error estimation procedure …


Tracking Knee Joint Functional Axes Through Tikhonov Filtering And Plűcker Coordinates, Wangdo Kim, Yoon-Hyuk Kim, António P. Veloso, Sean S. Kohles Mar 2013

Tracking Knee Joint Functional Axes Through Tikhonov Filtering And Plűcker Coordinates, Wangdo Kim, Yoon-Hyuk Kim, António P. Veloso, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Researchers have reported several compensation methods to estimate bone and joint position from a cluster of skin-mounted markers as influenced by Soft Tissue Artifacts (STA). Tikhonov Regularization Filtering (TRF) as a means to estimate Instantaneous Screw Axes (ISA) was introduced here as a means to reduce the displacement of a rigid body to its simplest geometric form. Recent studies have suggested that the ISA of the knee, i.e., Knee Functional Axes (KFA), might be closely connected to the estimation of constraint forces such as those due to medial and lateral connective tissues. The estimations of ISAs were known to be …


Synthetic Array Processing Of Ocean Ambient Noise For Higher Resolution Seabed Bottom Loss Estimation, Martin Siderius, Lanfranco Muzi, Chris H. Harrison, Peter L. Nielsen Mar 2013

Synthetic Array Processing Of Ocean Ambient Noise For Higher Resolution Seabed Bottom Loss Estimation, Martin Siderius, Lanfranco Muzi, Chris H. Harrison, Peter L. Nielsen

Electrical and Computer Engineering Faculty Publications and Presentations

Predicting transmission loss in the ocean often strongly depends on the bottom loss. Bottom loss can be estimated using ocean noise and vertical array beam-forming [Harrison and Simons, J. Acoust. Soc. Am. 112, 1377–1389 (2002)]. With finite length arrays, the bottom loss estimate using this method can be smoothed due to beam widths. This paper describes how the noise coherence function can be synthetically expanded, which is similar to extending the length of an array. A full wave ocean noise model is used to demonstrate, in simulation, how this leads to improvements in the resolution of bottom loss estimates.


Predicting Landslides In Real Time, Michael J. Olsen Mar 2013

Predicting Landslides In Real Time, Michael J. Olsen

TREC Project Briefs

The Oregon Department of Transportation, or ODOT, has an ongoing struggle to maintain public highways against earth movements such as erosion, earthquakes and landslides. An earthquake or landslide can close down a road for days, while highway workers fight to keep supply lines open and repair the damage. Particularly along Oregon’s coastal roads with high sea cliffs, these natural processes are a constant threat to transportation infrastructure. The damage caused by gradual erosion is typically not detectable until there is a landslide or other disaster, costing the state considerable time and money to repair. New technology has the potential to …


A Quantitative Analysis Of Memory Controller Page Policies, Matthew Blackmore Feb 2013

A Quantitative Analysis Of Memory Controller Page Policies, Matthew Blackmore

Dissertations and Theses

Two common goals in computing system design are increasing performance and decreasing power consumption. DRAM-based memory subsystems are a major component of both system performance and power consumption. Memory controllers employ strategies to efficiently schedule DRAM operations to reduce latency and to utilize DRAM low power modes when possible. One of the most important of these is the page policy, which determines when to close pages in DRAM. An effective DRAM memory controller page policy is important to minimizing power consumption and increasing system performance. This thesis explores the impact memory controller page policy has on performance as measured by …


Joint Angle Tracking With Inertial Sensors, Mahmoud Ahmed El-Gohary Feb 2013

Joint Angle Tracking With Inertial Sensors, Mahmoud Ahmed El-Gohary

Dissertations and Theses

The need to characterize normal and pathological human movement has consistently driven researchers to develop new tracking devices and to improve movement analysis systems. Movement has traditionally been captured by either optical, magnetic, mechanical, structured light, or acoustic systems. All of these systems have inherent limitations. Optical systems are costly, require fixed cameras in a controlled environment, and suffer from problems of occlusion. Similarly, acoustic and structured light systems suffer from the occlusion problem. Magnetic and radio frequency systems suffer from electromagnetic disturbances, noise and multipath problems. Mechanical systems have physical constraints that limit the natural body movement. Recently, the …


Just-In-Time Power Gating Of Gasp Circuits, Prachi Gulab Padwal Feb 2013

Just-In-Time Power Gating Of Gasp Circuits, Prachi Gulab Padwal

Dissertations and Theses

In modern integrated circuits, one way to reduce power consumption is to turn off power to parts of the circuit when those are idle. This method is called power gating. This thesis presents a state-preserving technique to achieve power savings in GasP family of asynchronous circuits by turning off the power when the circuit is idle. The power control logic turns on the power in anticipation of the receiving data. The power control logic turns off the power when the stage is idle either because it is empty or because the pipeline is clogged. The low logical effort of GasP …


Picture Of A Chelate In Exchange: The Crystal Structure Of Nahodotma, A 'Semi'-Hydrated Chelate, Katherine M. Payne, Edward J. Valente, Silvio Aime, Mauro Botta, Mark Woods Feb 2013

Picture Of A Chelate In Exchange: The Crystal Structure Of Nahodotma, A 'Semi'-Hydrated Chelate, Katherine M. Payne, Edward J. Valente, Silvio Aime, Mauro Botta, Mark Woods

Chemistry Faculty Publications and Presentations

Crystallography generally only provides static structural information. This can render it an ineffective technique for probing dynamic solution state processes. A crystal of HoDOTMA affords unique structures that effectively represent that of a lanthanide tetra-acetate chelate mid-way through the water exchange process.


3-D Terahertz Synthetic-Aperture Imaging And Spectroscopy, Samuel C. Henry Feb 2013

3-D Terahertz Synthetic-Aperture Imaging And Spectroscopy, Samuel C. Henry

Dissertations and Theses

Terahertz (THz) wavelengths have attracted recent interest in multiple disciplines within engineering and science. Situated between the infrared and the microwave region of the electromagnetic spectrum, THz energy can propagate through non-polar materials such as clothing or packaging layers. Moreover, many chemical compounds, including explosives and many drugs, reveal strong absorption signatures in the THz range. For these reasons, THz wavelengths have great potential for non-destructive evaluation and explosive detection. Three-dimensional (3-D) reflection imaging with considerable depth resolution is also possible using pulsed THz systems. While THz imaging (especially 3-D) systems typically operate in transmission mode, reflection offers the most …


Driver Behavior In The Presence Of Pedestrians At Signalized Intersections Operating The Flashing Yellow Arrow, David Hurwitz, Christopher M. Monsere Feb 2013

Driver Behavior In The Presence Of Pedestrians At Signalized Intersections Operating The Flashing Yellow Arrow, David Hurwitz, Christopher M. Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

This presentation provides an overview of the research on driver behavior in response to the Flashing Yellow Arrow (FHA) in in the presence of pedestrians


Examining Consumer Behavior And Travel Choices, Kelly J. Clifton, Christopher Devlin Muhs, Sara Morrissey, Tomás Morrissey, Kristina Marie Currans, Chloe Ritter Feb 2013

Examining Consumer Behavior And Travel Choices, Kelly J. Clifton, Christopher Devlin Muhs, Sara Morrissey, Tomás Morrissey, Kristina Marie Currans, Chloe Ritter

Civil and Environmental Engineering Faculty Publications and Presentations

This study represents a first attempt to answer a few of the questions that have arisen concerning multimodal transportation investments and the impacts of mode shifts on the business community. This research aims to merge the long history of scholarly work that examines the impacts of the built environment on non-work travel with the relatively new interest in consumer spending by mode of travel. This empirical study of travel choices and consumer spending across 89 businesses in the Portland metropolitan area shows there are important differences between the amounts customers spend on average at various businesses by their mode of …


Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan Jan 2013

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O3), and nitrate radical (NO3), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …


Spectrum Regrowth For Ofdm-Based Lte And Wimax Systems, Bosi Chen Jan 2013

Spectrum Regrowth For Ofdm-Based Lte And Wimax Systems, Bosi Chen

Dissertations and Theses

An abstract of the thesis of Bosi Chen for the Master of Science in Electrical and Computer Engineering presented Aug 1st, 2012. Title: Spectrum Regrowth for OFDM-based LTE and WiMAX Systems. In OFDM-based (Orthogonal Frequency Dimension Multiplexing) LTE (Long Term Evolution) and WiMAX (Worldwide Interoperability for Microwave Access) Systems, one of the critical components is the RF power amplifier. With current technologies, RF power amplifiers are not perfectly linear. The nonlinearity of an RF power amplifier is one of the main concerns in RF power amplifier design. The nonlinearity control is described by the out-of-band power emission levels, and the …


A 40 Ghz Power Amplifier Using A Low Cost High Volume 0.15 Um Optical Lithography Phemt Process, Kenneth W. Mays Jan 2013

A 40 Ghz Power Amplifier Using A Low Cost High Volume 0.15 Um Optical Lithography Phemt Process, Kenneth W. Mays

Dissertations and Theses

The demand for higher frequency applications is largely driven by bandwidth. The evolution of circuits in the microwave and millimeter frequency ranges always demands higher performance and lower cost as the technology and specification requirements evolve. Thus the development of new processes addressing higher frequencies and bandwidth requirements is essential to the growth of any semiconductor company participating in these markets. There exist processes which can perform in the higher frequency design space from a technical perspective. However, a cost effective solution must complement the technical merits for deployment. Thus a new 0.15 um optical lithography pHEMT process was developed …


Capillary Phenomena: Investigations In Compressed Bubble Migration, Geometric Wetting, And Blade-Bound Droplet Stability, William Henry Blackmore Jan 2013

Capillary Phenomena: Investigations In Compressed Bubble Migration, Geometric Wetting, And Blade-Bound Droplet Stability, William Henry Blackmore

Dissertations and Theses

Capillary flows continue to be important in numerous spacecraft systems where the effective magnitude of the gravity vector is approximately one millionth that of normal Earth gravity. Due to the free fall state of orbiting spacecraft, the effects of capillarity on the fluid systems onboard can dominate the fluid behavior over large length scales. In this research three investigations are pursued where the unique interplay between surface tension forces, wetting characteristics, and system geometry control the fluid behavior, whether in large systems aboard spacecraft, or micro-scale systems on Earth. First, efforts in support of two International Space Station (ISS) experiments …


Online Learning In A Chemical Perceptron, Peter Banda, Christof Teuscher, Matthew R. Lakin Jan 2013

Online Learning In A Chemical Perceptron, Peter Banda, Christof Teuscher, Matthew R. Lakin

Computer Science Faculty Publications and Presentations

Autonomous learning implemented purely by means of a synthetic chemical system has not been previously realized. Learning promotes reusability and minimizes the system design to simple input-output specification. In this article we introduce a chemical perceptron, the first full-featured implementation of a perceptron in an artificial (simulated) chemistry. A perceptron is the simplest system capable of learning, inspired by the functioning of a biological neuron. Our artificial chemistry is deterministic and discrete-time, and follows Michaelis-Menten kinetics. We present two models, the weight-loop perceptron and the weight-race perceptron, which represent two possible strategies for a chemical implementation of linear integration and …


Applying Technology Forecasting To New Product Development Target Setting Of Lcd Panels, Dong-Joon Lim, Neil Runde, Timothy R. Anderson Jan 2013

Applying Technology Forecasting To New Product Development Target Setting Of Lcd Panels, Dong-Joon Lim, Neil Runde, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

This chapter illustrates the Technology Forecasting using Data Envelopment Analysis (TFDEA) process on Liquid Crystal Display (LCD) performance characteristics from 1997 to 2012. The objective of this study is to forecast future state-of-the-arts (SOAs) specifications as well as to diagnose past technological advancement of the LCD industry. Appropriate characteristics were determined from a group of LCD technologists. Data was gathered from public databases and outlying data points were cross-referenced as a validity check. The TFDEA process is defined and its application to the dataset is described in detail. The results not only provide information on how LCD industry has evolved …


Technology Forecasting Of Digital Single-Lens Reflex Camera Market: The Impact Of Segmentation In Tfdea, Byung Sung Yoon, Apisit Charoensupyanan, Nan Hu, Rachanida Koosawangsri, Mimie Abdulai, Xiaowen Wang Jan 2013

Technology Forecasting Of Digital Single-Lens Reflex Camera Market: The Impact Of Segmentation In Tfdea, Byung Sung Yoon, Apisit Charoensupyanan, Nan Hu, Rachanida Koosawangsri, Mimie Abdulai, Xiaowen Wang

Engineering and Technology Management Faculty Publications and Presentations

With the advancement of digital image technology, the big change in the camera market is that digital single-lens reflex cameras (DSLRs) have replaced film type single-lens reflex cameras, which have seen very little development lately. This advancement is reflected in some core technologies of DSLRs such as digital image sensors and electronic shutter mechanisms, which have allowed taking photographs even in the toughest conditions. Therefore, as a disruptive technology, the developments in DSLR technologies are worthy of notice.

This paper utilizes technology forecast using data envelopment analysis (TFDEA), which is a quantitative forecasting method. In the study, we use input …


Forecasting Microprocessor Technology In The Multicore Era Using Tfdea, Saranya Durairajan, Maria Ibarra Prado, Noshad Rahimi, Shabnam Razeghian Jahromi Jan 2013

Forecasting Microprocessor Technology In The Multicore Era Using Tfdea, Saranya Durairajan, Maria Ibarra Prado, Noshad Rahimi, Shabnam Razeghian Jahromi

Engineering and Technology Management Faculty Publications and Presentations

Technological advancements in the microprocessor industry are benchmarked and gauged against a set of diverse criteria, specific to the fabrication process, usage as well as achieved performance. Changing trends in the appeal factor as well as wide variety of growing application of microprocessors in different industries also have a defining impact in the advancement of the technological features in future. This study improves the previous investigation in forecasting microprocessors? technology and uses Technology Forecasting using Data Envelopment Analysis (TFDEA) methodology for an enhanced model. The study takes advantage of the recent microprocessor dataset including multi core processors, from a variety …


Incorporating Value Judgment In Technology Forecasting Using Data Envelopment Analysis, Dong-Joon Lim, Timothy R. Anderson Jan 2013

Incorporating Value Judgment In Technology Forecasting Using Data Envelopment Analysis, Dong-Joon Lim, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

Technology Forecasting using Data Envelopment Analysis (TFDEA) has been employed to a wide range of applications because of its ability to model complex tradeoffs. The very name indicates that it is based on Data Envelopment Analysis (DEA) which has strength that it doesn?t require fixed a priori weighting scheme. Instead, it adopts dynamic weighting scheme that each data point can choose their best possible weights. However, it is well known that this flexibility may result in extreme weights that may be considered unrealistic in certain applications and has been one subject of DEA researches. This paper extends the standard TFDEA …


Forecasting Hybrid Electric Vehicles Using Tfdea, Shabnam Razeghian Jahromi, Anca-Alexandra Tudori, Timothy R. Anderson Jan 2013

Forecasting Hybrid Electric Vehicles Using Tfdea, Shabnam Razeghian Jahromi, Anca-Alexandra Tudori, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

The Toyota Prius was introduced in Japan fifteen years ago and over 60 additional hybrid electric vehicles automobiles and redesigns have been brought to the market around the world since that time. There is major interest in future of the electric cars as using ?the alternative fuel? can significantly decrease the environmental and fuel dependency concerns. This work has used data envelopment analysis to forecast the future of hybrid electric cars. It is based on a previous research on the same subject with an improvement in input-output model that has enhanced the outcomes to a great extent. The former study …


Model For Acid-Base Chemistry In Nanoparticle Growth (Mabnag), Taina Yli-Juuti, Kelley Barsanti, L. Hildebrandt Ruiz, Antti-Jussi Kieloaho, U. Makkonen, Tuukka Petäjä, Taina Ruuskanen, Markku Kulmala, Ilona Riipinen Jan 2013

Model For Acid-Base Chemistry In Nanoparticle Growth (Mabnag), Taina Yli-Juuti, Kelley Barsanti, L. Hildebrandt Ruiz, Antti-Jussi Kieloaho, U. Makkonen, Tuukka Petäjä, Taina Ruuskanen, Markku Kulmala, Ilona Riipinen

Civil and Environmental Engineering Faculty Publications and Presentations

Climatic effects of newly-formed atmospheric secondary aerosol particles are to a large extent determined by their condensational growth rates. However, all the vapours condensing on atmospheric nanoparticles and growing them to climatically relevant sizes are not identified yet and the effects of particle phase processes on particle growth rates are poorly known. Besides sulfuric acid, organic compounds are known to contribute significantly to atmospheric nanoparticle growth. In this study a particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) was developed to study the effect of salt formation on nanoparticle growth, which has been proposed as a potential …


Positive Matrix Factorization Of Pm2.5 - Eliminating The Effects Of Gas/Particle Partitioning Of Semivolatile Organic Compounds, Mingjie Xie, Kelley Barsanti, Michael P. Hannigan, Steven J. Dutton, Sverre Vedal Jan 2013

Positive Matrix Factorization Of Pm2.5 - Eliminating The Effects Of Gas/Particle Partitioning Of Semivolatile Organic Compounds, Mingjie Xie, Kelley Barsanti, Michael P. Hannigan, Steven J. Dutton, Sverre Vedal

Civil and Environmental Engineering Faculty Publications and Presentations

Gas-phase concentrations of semi-volatile organic compounds (SVOCs) were calculated from gas/particle (G/P) partitioning theory using their measured particle-phase concentrations. The particle-phase data were obtained from an existing filter measurement campaign (27 January 2003-2 October 2005) as a part of the Denver Aerosol Sources and Health (DASH) study, including 970 observations of 71 SVOCs (Xie et al., 2013). In each compound class of SVOCs, the lighter species (e.g. docosane in n-alkanes, fluoranthene in PAHs) had higher total concentrations (gas + particle phase) and lower particle-phase fractions. The total SVOC concentrations were analyzed using positive matrix factorization (PMF). Then the results were …


Analyzing Experimental Data And Model Parameters: Implications For Predictions Of Soa Using Chemical Transport Models, Kelley Barsanti, Annmarie G. Carlton, Serena H. Chung Jan 2013

Analyzing Experimental Data And Model Parameters: Implications For Predictions Of Soa Using Chemical Transport Models, Kelley Barsanti, Annmarie G. Carlton, Serena H. Chung

Civil and Environmental Engineering Faculty Publications and Presentations

Despite critical importance for air quality and climate predictions, accurate representation of secondary organic aerosol (SOA) formation remains elusive. An essential addition to the ongoing discussion of improving model predictions is an acknowledgement of the linkages between experimental conditions, parameter optimization and model output, as well as the linkage between empirically-derived partitioning parameters and the physicochemical properties of SOA they represent in models. In this work, a "best available" set of SOA modeling parameters is selected by comparing predicted SOA yields and mass concentrations with observed yields and mass concentrations from a comprehensive list of published smog chamber studies. Evaluated …


Evolution Of Multispectral Aerosol Optical Properties In A Biogenically-Influenced Urban Environment During The Cares Campaign, Madhu Gyawali, W. Patrick Arnott, Rahul A. Zaveri, C. Song, Mikhail Pekour, B. Flowers, Manvendra K. Dubey, Ari Setyan, Qi Zhang, Joseph Harworth, James Gregory Radney, Dean B. Atkinson, S. China, Claudio Mazzoleni, Kyle Gorkowski, R. Subramanian, B. Tom Jobson, Hans Moosmüller Jan 2013

Evolution Of Multispectral Aerosol Optical Properties In A Biogenically-Influenced Urban Environment During The Cares Campaign, Madhu Gyawali, W. Patrick Arnott, Rahul A. Zaveri, C. Song, Mikhail Pekour, B. Flowers, Manvendra K. Dubey, Ari Setyan, Qi Zhang, Joseph Harworth, James Gregory Radney, Dean B. Atkinson, S. China, Claudio Mazzoleni, Kyle Gorkowski, R. Subramanian, B. Tom Jobson, Hans Moosmüller

Chemistry Faculty Publications and Presentations

Ground-based aerosol measurements made in June 2010 within Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area are used to investigate the evolution of multispectral optical properties as the urban aerosols aged and interacted with biogenic emissions. Along with black carbon and non-refractory aerosol mass and composition observations, spectral absorption (ᵝabs), scattering (ᵝsca), and extinction (ᵝext) coefficients for wavelengths ranging from 355 to 1064nm were measured at both sites using photoacoustic (PA) instruments with integrating nephelometers and using cavity ring-down (CRD) instruments. The …