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Civil and Environmental Engineering Commons™
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Articles 301 - 330 of 424
Full-Text Articles in Civil and Environmental Engineering
Multiuser Perspectives On Separated, On-Street Bicycle Infrastructure, Christopher Monsere, Nathan Mcneil, Jennifer Dill
Multiuser Perspectives On Separated, On-Street Bicycle Infrastructure, Christopher Monsere, Nathan Mcneil, Jennifer Dill
Civil and Environmental Engineering Faculty Publications and Presentations
In the early fall of 2009, the Bureau of Transportation in Portland, Oregon, installed a cycle track and a pair of buffered bike lanes in downtown Portland. A major objective was to test facilities that were thought to bring higher levels of comfort to bicycle riders through increased separation from motor vehicle traffic. After one year of use, an evaluation was conducted to determine how the facilities affected the experience of the various users. Intercept surveys of cyclists (n 5 248), motorists (n 5 262), pedestrians (n 5 198), and adjacent businesses (n 5 59) showed improved perceptions of safety …
Air Quality At Bus Stops: Empirical Analysis Of Exposure To Particulate Matter At Bus Stop Shelters, Miguel Figliozzi, Adam Moore, Christopher Monsere
Air Quality At Bus Stops: Empirical Analysis Of Exposure To Particulate Matter At Bus Stop Shelters, Miguel Figliozzi, Adam Moore, Christopher Monsere
Civil and Environmental Engineering Faculty Publications and Presentations
Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter (PM), because of their proximity to the roadway. Current guidelines for the location and the design of bus stops do not take into account air quality or exposure considerations. This study compared the exposure of transit riders waiting at three-sided bus stop shelters that either faced the roadway traffic or faced away from the roadway traffic. Shelters were instrumented with air quality monitoring equipment, …
Bottom Topography Mapping Via Nonlinear Data Assimilation, Edward D. Zaron, Marie-Aude Pradal, Patrick D. Miller, Alan F. Blumberg, Nickitas Georgas, Wei Li, Julia Muccino Cornuelle
Bottom Topography Mapping Via Nonlinear Data Assimilation, Edward D. Zaron, Marie-Aude Pradal, Patrick D. Miller, Alan F. Blumberg, Nickitas Georgas, Wei Li, Julia Muccino Cornuelle
Civil and Environmental Engineering Faculty Publications and Presentations
A variational data assimilation method is described for bottom topography mapping in rivers and estuaries using remotely sensed observations of water surface currents. The velocity field and bottom topography are related by the vertically integrated momentum and continuity equations, leading to a nonlinear inverse problem for bottom topography, which is solved using a Picard iteration strategy combined with a nonlinear line search. An illustration of the method is shown for Haverstraw Bay, in the Hudson River, where the known bottom topography is well reconstructed. Once the topography has been estimated, currents and water levels may be forecast. The method makes …
Calibration Of Highway Safety Manual: Predictive Models For Oregon State Highways, Fei Xie, Kristie Gladhill, Karen Dixon, Christopher Monsere
Calibration Of Highway Safety Manual: Predictive Models For Oregon State Highways, Fei Xie, Kristie Gladhill, Karen Dixon, Christopher Monsere
Civil and Environmental Engineering Faculty Publications and Presentations
The recently released "Highway Safety Manual" (HSM) published by AASHTO provides a comprehensive set of tools for evaluating and identifying opportunities to improve safety for highway facilities. Included in the HSM is a quantitative method for predicting crashes on the basis of recently developed scientific approaches. These predictive methods currently exist for three facility types: rural two-lane roads; rural multilane highways; and urban and suburban arterial highways. To enhance precision, each HSM predictive method should be calibrated for location conditions. This paper demonstrates the HSM calibration procedure for total crashes in Oregon. The research identified three critical data collection limitations …
Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi
Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi
Civil and Environmental Engineering Faculty Publications and Presentations
This report describes analysis undertaken to establish a method for incorporating traffic operations and ITS strategies into the GreenSTEP model. We first discuss operations impacts on fuel economy and delay from the literature. Then, an investigation of delay adjustments in GreenSTEP shows that different methods of representing delay changes lead to similar (and small) impacts on fuel economy. From this result we establish average speed adjustment by congestion level as the preferred method for incorporating delay effects from operations improvements. An investigation of aggregate traffic operations impacts produces estimates of base speeds without operations improvements, maximum speeds with full operational …
Maintaining Safe, Efficient And Sustainable Intermodal Transport Through The Port Of Portland, David A. Jay, Jiayi Pan
Maintaining Safe, Efficient And Sustainable Intermodal Transport Through The Port Of Portland, David A. Jay, Jiayi Pan
Civil and Environmental Engineering Faculty Publications and Presentations
About $15 billion of freight passes annually through the Lower Columbia River (LCR) navigation channel to reach Portland and Vancouver, where most of it connects with land transport. This commerce plays a vital role in sustaining the regional economy and connecting Oregon to the global economy. The timely connection of truck and rail transport with vessels is vital, especially for export traffic. This link is susceptible to disruption if water depths in the navigation channel are shallower than expected, leading to delays and/or draft limitations. Moreover, ship drafts have increased in recent decades, 25% of the vessels calling in the …
Non-Stationary Internal Tides Observed With Satellite Altimetry, Richard D. Ray, Edward D. Zaron
Non-Stationary Internal Tides Observed With Satellite Altimetry, Richard D. Ray, Edward D. Zaron
Civil and Environmental Engineering Faculty Publications and Presentations
Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-1 tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 cm2. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions …
Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet
Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet
Civil and Environmental Engineering Faculty Publications and Presentations
There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include …
Statistical Comparisons Of Watershed-Scale Response To Climate Change In Selected Basins Across The United States, John Risley, Hamid Moradkhani, Lauren Hay, Steve Markstrom
Statistical Comparisons Of Watershed-Scale Response To Climate Change In Selected Basins Across The United States, John Risley, Hamid Moradkhani, Lauren Hay, Steve Markstrom
Civil and Environmental Engineering Faculty Publications and Presentations
In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual …
Bayesian Models For Reidentification Of Trucks Over Long Distances On The Basis Of Axle Measurement Data, Mecit Cetin, Christopher Monsere, Andrew Nichols
Bayesian Models For Reidentification Of Trucks Over Long Distances On The Basis Of Axle Measurement Data, Mecit Cetin, Christopher Monsere, Andrew Nichols
Civil and Environmental Engineering Faculty Publications and Presentations
Vehicle reidentification methods can be used to anonymously match vehicles crossing 2 different locations on the basis of vehicle attribute data. In this article, reidentification methods are developed to match commercial vehicles that cross 2 weigh-in-motion sites in Oregon that are separated by 145 miles. Using vehicle length and axle data as attributes to characterize vehicles, a Bayesian model is developed that uses probability density functions obtained by fitting Gaussian mixture models to a sample data set of matched vehicles. The reidentification model when applied to a test data set (where each downstream vehicle also crosses the upstream site) matches …
Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup
Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup
Civil and Environmental Engineering Faculty Publications and Presentations
Thermal infrared (IR) based particle image velocimetry (PIV) is used to measure the evolution of velocity, turbulent kinetic energy (TKE), and the TKE dissipation rate at the water surface in the tidally influenced Snohomish River. Patterns of temperature variability in the IR imagery arise from disruption of the cool skin layer and are used to estimate the 2D velocity field. Comparisons of IR based PIV mean velocity made against a collocated acoustic velocimeter demonstrate high correlation (r2 > 0.9). Over a tidal period, surface TKE computed from the IR velocity varies from 10-4 J·kg-1 to 3x10-3 J·kg-1, with an average difference …
Key Factors Affecting The Accuracy Of Reidentification Of Trucks Over Long Distances Based On Axle Measurement Data, Mecit Cetin, Christopher Monsere, Andrew Nichols, Ilyas Ustun
Key Factors Affecting The Accuracy Of Reidentification Of Trucks Over Long Distances Based On Axle Measurement Data, Mecit Cetin, Christopher Monsere, Andrew Nichols, Ilyas Ustun
Civil and Environmental Engineering Faculty Publications and Presentations
Vehicle reidentification methods can be used to anonymously match vehicles crossing two locations based on vehicle attribute data. This paper investigates key factors that affect the accuracy of vehicle reidentification algorithms. The analyses are performed with reidentification algorithms to match commercial vehicles that cross upstream and down-stream pairs of weigh-in-motion (WIM) sites that are separated by long distances, ranging from 70 to 214 mi. The data to support this research come from 17 fixed WIM sites in Oregon. Data from 14 pairs of WIM sites are used to evaluate how various factors affect matching accuracy; factors include the distance between …
A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes
A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes
Civil and Environmental Engineering Faculty Publications and Presentations
The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained iteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where computer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic equations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by rotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the …
Improving The Characterization Of Initial Condition For Ensemble Streamflow Prediction Using Data Assimilation, Caleb Matthew Dechant, Hamid Moradkhani
Improving The Characterization Of Initial Condition For Ensemble Streamflow Prediction Using Data Assimilation, Caleb Matthew Dechant, Hamid Moradkhani
Civil and Environmental Engineering Faculty Publications and Presentations
Within the National Weather Service River Forecast System, water supply forecasting is performed through Ensemble Streamflow Prediction (ESP). ESP relies both on the estimation of initial conditions and historically resampled forcing data to produce seasonal volumetric forecasts. In the western US, the accuracy of initial condition estimation is particularly important due to the large quantities of water stored in mountain snowpack. In order to improve the estimation of snow quantities, this study explores the use of ensemble data assimilation. Rather than relying entirely on the model to create single deterministic initial snow water storage, as currently implemented in operational forecasting, …
Circulation, Sediment Concentration And Oxygen Depletion In The Tidal Ems River, Stefan A. Talke, Huib E. De Swart
Circulation, Sediment Concentration And Oxygen Depletion In The Tidal Ems River, Stefan A. Talke, Huib E. De Swart
Civil and Environmental Engineering Faculty Publications and Presentations
We present measurements which show that the tidal Ems River in Germ any is extremely muddy over a 30 km + turbid zone, with fluid mud o f 1-2 m thickness covering the bed with suspended sediment concentrations (SSC) o f greater than 50 kg.m-3. Moreover, we show that these elevated SSC contain large quantities of organic material which deplete dissolved oxygen (DO) and produce summertime hypoxic zones. Using mathematical modeling, we develop simplified representations o f the estuary physics that reproduce the tidally-averaged circulation, SSC distribution, and oxygen depletion. These models show that SSC and oxygen concentrations …
Freight Distribution Problems In Congested Urban Areas: Fast And Effective Solution Procedures To Time-Dependent Vehicle Routing Problems, Miguel A. Figliozzi
Freight Distribution Problems In Congested Urban Areas: Fast And Effective Solution Procedures To Time-Dependent Vehicle Routing Problems, Miguel A. Figliozzi
Civil and Environmental Engineering Faculty Publications and Presentations
Congestion is a common phenomenon in all medium to large cities of the world. Reliability of freight movement in urban areas is an important issue to manufacturing or service companies whose operation is based in just-in-time approaches. These companies tend to provide high value or time sensitive products/services. As congestion increases, carriers face increasing challenges to satisfy their time sensitive customers in an economical way. Route designs or schedules which require long computation times or ignore travel time variations will result in inefficient and suboptimal solutions. Poorly designed routes that lead freight vehicles into congested arteries and streets not only …
Low Flow Forecasting With A Lead Time Of 14 Days For Navigation And Energy Supply In The Rhine River, Mehmet C. Demirel, Martijn Booij
Low Flow Forecasting With A Lead Time Of 14 Days For Navigation And Energy Supply In The Rhine River, Mehmet C. Demirel, Martijn Booij
Civil and Environmental Engineering Faculty Publications and Presentations
Low flow forecasting, days or even months in advance, is particularly important to the efficient operation of power plants and freight shipment. This study presents a low flow forecasting model with a lead time of 14 days for the Rhine River. The forecasts inherit uncertainty sources mainly because of model parameterization. Therefore, a systematic uncertainty analysis is applied to indicate the major uncertainty sources in the results. Firstly, the Rhine basin is divided into 7 major sub-basins. Each sub-basin is modeled separately with a data-driven model and the output discharges are routed to Lobith after German-Dutch border with another data-driven …
Uncertainty Analysis Of A Low Flow Model For The Rhine River, Mehmet C. Demirel, Martijn Booij
Uncertainty Analysis Of A Low Flow Model For The Rhine River, Mehmet C. Demirel, Martijn Booij
Civil and Environmental Engineering Faculty Publications and Presentations
It is widely recognized that hydrological models are subject to parameter uncertainty. However, little attention has been paid so far to the uncertainty in parameters of the data-driven models like weights in neural networks. This study aims at applying a structured uncertainty analysis to a data-driven model for low flow forecasting with a lead time of 14 days in the Rhine River. In the modeling phase, the Rhine basin is divided into seven major sub-basins. Each sub-basin is modeled separately with a data-driven model and the output discharges were routed to Lobith with another data-driven model. Basin averaged precipitation, basin …
Highway Safety Investigation Manual For The Oregon Department Of Transportation, Karen Dixon, Christopher Monsere
Highway Safety Investigation Manual For The Oregon Department Of Transportation, Karen Dixon, Christopher Monsere
Civil and Environmental Engineering Faculty Publications and Presentations
Across the state, region, and nation highway safety investigators have developed a wide variety of tools and techniques for highway safety investigation procedures. Analysis techniques can range from systematic evaluation approaches such as the Oregon Department of Transportation’s (ODOT’s) Safety Priority Index System (SPIS) down to specific localized safety assessment strategies. It is important to develop consistent methods for safety evaluations across Oregon to ensure that safety investigations are conducted in a similar manner. It is also important to develop a screening process for proper highway safety investigations and document the procedures used for this assessment.
The objective of this …
Multiple Trophic Levels Fueled By Recirculation In The Columbia River Plume, Raphael M. Kudela, Alexander R. Horner-Devine, Neil S. Banas, Barbara M. Hickey, Tawnya D. Peterson, Ryan M. Mccabe, Evelyn J. Lessard, Elizabeth R. Frame, Kenneth W. Bruland, David A. Jay, Jay O. Peterson, William T. Peterson, P. Michael Kosro, Sherry L. Palacios, Maeve C. Lohan, Edward P. Dever
Multiple Trophic Levels Fueled By Recirculation In The Columbia River Plume, Raphael M. Kudela, Alexander R. Horner-Devine, Neil S. Banas, Barbara M. Hickey, Tawnya D. Peterson, Ryan M. Mccabe, Evelyn J. Lessard, Elizabeth R. Frame, Kenneth W. Bruland, David A. Jay, Jay O. Peterson, William T. Peterson, P. Michael Kosro, Sherry L. Palacios, Maeve C. Lohan, Edward P. Dever
Civil and Environmental Engineering Faculty Publications and Presentations
Large rivers represent gateways for the transport of terrigenous and anthropogenic material to the coastal ocean. Here we document a ?700 km2 recirculation or bulge associated with the Columbia River plume that retains recently discharged river water sufficiently to create a regional bioreactor. Fueled by a fluvial nitrate source, this feature stimulated growth across three trophic levels and may buffer this gateway system during periods of increased warming and stratification that lead to decreased ocean productivity, potentially enhancing production at multiple trophic levels and enriching surfacewaters far from the river mouth.
Mixing Layer Dynamics In Separated Flow Over An Estuarine Sill With Variable Stratification, Stefan A. Talke, Alexander R. Horner-Devine, C. Chris Chickadel
Mixing Layer Dynamics In Separated Flow Over An Estuarine Sill With Variable Stratification, Stefan A. Talke, Alexander R. Horner-Devine, C. Chris Chickadel
Civil and Environmental Engineering Faculty Publications and Presentations
We investigate the generation of a mixing layer in the separated flow behind an estuarine sill (height H ∼ 4 m) in the Snohomish River, Washington as part of a larger investigation of coherent structures using remote and in situ sensing. During increasing ebb flows the depth d and stratification decrease and a region of sheared flow characterized by elevated production of turbulent kinetic energy develops. Profiles of velocity and acoustic backscatter exhibit coherent fluctuations of order 0.1 Hz and are used to define the boundaries of the mixing layer. Variations in the mixing layer width and its embedded coherent …
The Effect Of Tidal Asymmetry And Temporal Settling Lag On Sediment Trapping In Tidal Estuaries, Alexander S. Chernetsky, Henk M. Schuttelaars, Stefan A. Talke
The Effect Of Tidal Asymmetry And Temporal Settling Lag On Sediment Trapping In Tidal Estuaries, Alexander S. Chernetsky, Henk M. Schuttelaars, Stefan A. Talke
Civil and Environmental Engineering Faculty Publications and Presentations
Over decades and centuries, the mean depth of estuaries changes due to sea-level rise, land subsidence, infilling, and dredging projects. These processes produce changes in relative roughness (friction) and mixing, resulting in fundamental changes in the characteristics of the horizontal (velocity) and vertical tides (sea surface elevation) and the dynamics of sediment trapping. To investigate such changes, a 2DV model is developed. The model equations consist of the width-averaged shallow water equations and a sediment balance equation. Together with the condition of morphodynamic equilibrium, these equations are solved analytically by making a regular expansion of the various physical variables in …
Characteristics Of Transitions In Freeway Traffic, Robert L. Bertini, Soyoung Ahn
Characteristics Of Transitions In Freeway Traffic, Robert L. Bertini, Soyoung Ahn
Civil and Environmental Engineering Faculty Publications and Presentations
This research seeks to understand the characteristics of transitions as freeway traffic changes from one state to another. This study addresses the features of two types of transitions; transitions near a merge and transitions along shock waves during the onsets and dissipations of queues at several freeway sites.
Individual vehicle trajectory data were analyzed for studying the transitions near a merge. The length of a transition zone was measured by analyzing the spatial changes in flow, density and speed along kinematic waves near a merge. It was found that the length of transition in terms of flow, density and speed …
Improving Robustness Of Hydrologic Parameter Estimation By The Use Of Moving Block Bootstrap Resampling, Hamid Moradkhani, Mohammad Ebtehaj, Hoshin V. Gupta
Improving Robustness Of Hydrologic Parameter Estimation By The Use Of Moving Block Bootstrap Resampling, Hamid Moradkhani, Mohammad Ebtehaj, Hoshin V. Gupta
Civil and Environmental Engineering Faculty Publications and Presentations
Modeling of natural systems typically involves conceptualization and parameterization to simplify the representations of the underlying process. Objective methods for estimation of the model parameters then require optimization of a cost function, representing a measure of distance between the observations and the corresponding model predictions, typically by calibration in a static batch mode and/or via some dynamic recursive optimization approach. Recently, there has been a focus on the development of parameter estimation methods that appropriately account for different sources of uncertainty. In this context, we introduce an approach to sample the optimal parameter space that uses nonparametric block bootstrapping coupled …
The Surface Expression Of Semidiurnal Internal Tides Near A Strong Source At Hawaii. Part I: Observations And Numerical Predictions, Cedric Chavanne, P. Flament, Glenn S. Carter, M. Merrifield, D. Luther, Edward D. Zaron, K. W. Gurgel
The Surface Expression Of Semidiurnal Internal Tides Near A Strong Source At Hawaii. Part I: Observations And Numerical Predictions, Cedric Chavanne, P. Flament, Glenn S. Carter, M. Merrifield, D. Luther, Edward D. Zaron, K. W. Gurgel
Civil and Environmental Engineering Faculty Publications and Presentations
Observations of semidiurnal currents fromhigh-frequency radioDoppler currentmeters andmoored acoustic Doppler current profilers (ADCPs) in the Kauai Channel, Hawaii, are described and compared with two primitive equation numerical models of the tides. The Kauai Channel, separating the islands of Oahu and Kauai, is a site of strong internal tide generation by the barotropic tides flowing over Kaena Ridge, the subsurface extension of Oahu. The nature and impacts of internal tide generation in the Kauai Channel were intensively studied during the 2002–03 near-field component of the Hawaii Ocean Mixing Experiment. Comparisons of observed coherent (i.e., phase locked to the astronomical forcing)M2 …
Freight Performance Measures: Approach Analysis, B. Starr Mcmullen, Christopher M. Monsere
Freight Performance Measures: Approach Analysis, B. Starr Mcmullen, Christopher M. Monsere
Civil and Environmental Engineering Faculty Publications and Presentations
This report reviews the existing state of the art and also the state of the practice of freight performance measurement. Most performance measures at the state level have aimed at evaluating highway or transit infrastructure performance with an emphasis on passenger transportation. Freight performance measurement ultimately requires evaluation of performance of the entire freight transportation system, which includes highways, waterways, rail, air, and modal connections. This requires considerable expansion of thinking beyond the traditional focus of state Departments of Transportation (DOTs) on highway performance.
This project builds upon past and current work in the area of freight performance measurement and …
River Influences On Shelf Ecosystems: Introduction And Synthesis, Barbara M. Hickey, Raphael M. Kudela, Jonathan Nash, Kenneth W. Bruland, William T. Peterson, P. Maccready, Evelyn J. Lessard, David A. Jay, Neil S. Banas, Antonio M. Baptista, Edward P. Dever, P. Michael Kosro, Levi Kilcher, Alexander R. Horner-Devine, Edward D. Zaron, Ryan M. Mccabe, Jay O. Peterson, Philip M. Orton, Jiayi Pan
River Influences On Shelf Ecosystems: Introduction And Synthesis, Barbara M. Hickey, Raphael M. Kudela, Jonathan Nash, Kenneth W. Bruland, William T. Peterson, P. Maccready, Evelyn J. Lessard, David A. Jay, Neil S. Banas, Antonio M. Baptista, Edward P. Dever, P. Michael Kosro, Levi Kilcher, Alexander R. Horner-Devine, Edward D. Zaron, Ryan M. Mccabe, Jay O. Peterson, Philip M. Orton, Jiayi Pan
Civil and Environmental Engineering Faculty Publications and Presentations
River Influences on Shelf Ecosystems (RISE) is the first comprehensive interdisciplinary study of the rates and dynamics governing the mixing of river and coastal waters in an eastern boundary current system, as well as the effects of the resultant plume on phytoplankton standing stocks, growth and grazing rates, and community structure. The RISE Special Volume presents results deduced from four field studies and two different numerical model applications, including an ecosystem model, on the buoyant plume originating from the Columbia River. This introductory paper provides background information on variability during RISE field efforts as well as a synthesis of results, …
Initial Expansion Of The Columbia River Tidal Plume: Theory And Remote Sensing Observations, David A. Jay, Edward D. Zaron, Jiayi Pan
Initial Expansion Of The Columbia River Tidal Plume: Theory And Remote Sensing Observations, David A. Jay, Edward D. Zaron, Jiayi Pan
Civil and Environmental Engineering Faculty Publications and Presentations
Analysis of the Columbia River tidal plume using Lagrangian frontal equations provides a concise description of the evolution of frontal depth H, velocity U, reduced gravity g', and frontal internal Froude number F (sub R) . Because the estuary mouth is narrow, the initial radial plume motion is supercritical (F (sub R) > 1) for up to 12 hours. Understanding this supercritical phase is vital, because plume properties change rapidly, with strong ecosystem impacts. To analyze this expansion, analytical and numerical models (the latter with three mixing formulations) were tested. Model results are compared to synthetic aperture radar images to verify …
Organic Particulate Matter Formation At Varying Relative Humidity Using Surrogate Secondary And Primary Organic Compounds With Activity Corrections In The Condensed Phase Obtained Using A Method Based On The Wilson Equation, James F. Pankow, E. I. Chang
Organic Particulate Matter Formation At Varying Relative Humidity Using Surrogate Secondary And Primary Organic Compounds With Activity Corrections In The Condensed Phase Obtained Using A Method Based On The Wilson Equation, James F. Pankow, E. I. Chang
Civil and Environmental Engineering Faculty Publications and Presentations
Secondary organic aerosol (SOA) formation in the atmosphere is currently often modeled using a multiple lumped "two-product" (N · 2p) approach. The N · 2p approach neglects: 1) variation of activity coefficient (i) values and mean molecular weight MW in the particulate matter (PM) phase; 2) water uptake into the PM; and 3) the possibility of phase separation in the PM. This study considers these effects by adopting an (N ·2p)pMW, approach (is a phase index). Specific chemical structures are assigned to 25 lumped SOA compounds and to 15 representative primary organic aerosol (POA) compounds to allow calculation of i …
A Survey Of China's Logistics Industry And The Impacts Of Transport Delays On Importers And Exporters, Zeyan Zhang, Miguel Andres Figliozzi
A Survey Of China's Logistics Industry And The Impacts Of Transport Delays On Importers And Exporters, Zeyan Zhang, Miguel Andres Figliozzi
Civil and Environmental Engineering Faculty Publications and Presentations
In the last decades, China?s booming economy has greatly benefited from globalization and trade liberalization. China has found a niche as the world?s manufacturing centre and it is playing a crucial role in a growing number of global supply chains. This research focuses on the performance of international and domestic transport and logistics systems as perceived by Chinese importers and exporters. A broad literature review of Chinese meteoric logistics industry development is provided. Results and analysis of in?depth interviews with Chinese importers and exporters are presented. These interviews provide significant information regarding international freight transport chains, the impact of delays …