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Portland State University

2012

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Articles 61 - 67 of 67

Full-Text Articles in Engineering

Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith Jan 2012

Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

The probability that freshly nucleated nanoparticles can survive to become cloud condensation nuclei is highly sensitive to particle growth rates. Much of the growth of newly formed ambient nanoparticles can be attributed to oxidized organic vapors originating from biogenic precursor gases. In this study we investigated the chemical composition of size-selected biogenic nanoparticles in the size range from 10 to 40 nm. Particles were formed in a flow tube reactor by ozonolysis ofα-pinene and analyzed with a Thermal Desorption Chemical Ionization Mass Spectrometer. While we found similar composition in 10 and 20 nm particles, the relative amounts of …


Climate Change Impact Assessment For Surface Transportation In The Pacific Northwest And Alaska, John Macarthur, Philip Mote, Miguel A. Figliozzi, Jason Ideker, Ming Lee Jan 2012

Climate Change Impact Assessment For Surface Transportation In The Pacific Northwest And Alaska, John Macarthur, Philip Mote, Miguel A. Figliozzi, Jason Ideker, Ming Lee

Civil and Environmental Engineering Faculty Publications and Presentations

The states in the Pacific Northwest and Alaska region share interconnected transportation networks for people, goods, and services that support the regional economy, mobility, and human safety. Regional weather has and will continue to affect the physical condition and serviceability of these networks, yet the nature of climate changes and their potential impacts on the regional transportation system and its use are very poorly understood. The world’s leading climate scientists, such as the Intergovernmental Panel for Climate Change, have reached consensus that global climate changes are being observed and will continue into the future, particularly increasing temperatures. Given this fact, …


Plasma Levels Of Polychlorinated Biphenyls, Non-Hodgkin Lymphoma, And Causation, Michael D. Freeman, Sean S. Kohles Jan 2012

Plasma Levels Of Polychlorinated Biphenyls, Non-Hodgkin Lymphoma, And Causation, Michael D. Freeman, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Polychlorinated biphenyls (PCBs) are synthetic chlorinated hydrocarbons that have extensively polluted the environment and bioaccumulated in the food chain. PCBs have been deemed to be probable carcinogens by the Environmental Protection Agency, and exposure to high levels of PCBs has been consistently linked to increased risk of non-Hodgkin lymphoma (NHL). In the present article we present a forensic epidemiologic evaluation of the causal relationship between NHL and elevated PCB levels via application of the Bradford-Hill criteria. Included in the evaluation is a meta-analysis of the results of previously published case-control studies in order to assess the strength of association between …


An Introduction To Technology Forecasting With A Tfdea Excel Add-In, Dong-Joon Lim, Timothy R. Anderson Jan 2012

An Introduction To Technology Forecasting With A Tfdea Excel Add-In, Dong-Joon Lim, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

This paper describes an Excel add-in program that can run TFDEA (Technology Forecasting using Data Envelopment Anlaysis) within the spreadsheet. It utilizes freely available statistical software R and its packages developed by Statconn. This add-in allows access to both user-friendly tools for data manipulation in spreadsheet available and the power and precision of the results via R.


R&D Target-Setting Difficulties Addressed Through Emergent Method: Technology Forecasting Using Data Envelopment Analysis, Ann-Marie Lamb, Timothy R. Anderson, Tugrul Unsal Daim Jan 2012

R&D Target-Setting Difficulties Addressed Through Emergent Method: Technology Forecasting Using Data Envelopment Analysis, Ann-Marie Lamb, Timothy R. Anderson, Tugrul Unsal Daim

Engineering and Technology Management Faculty Publications and Presentations

The aim of this study is to provide a foundation for researchers and managers to further discuss and resolve difficulties associated with R&D target-setting. While multiple studies mention the difficulty of R&D target-setting, few studies exist which compile reasons for these difficulties; nor do they address this issue in any detail. This paper provides what appears to be one of the first studies outlining reasons for R&D target-setting difficulties through a literature review; then also provides an initial set of analyses and results after applying an emerging quantitative method, Technology Forecasting Using Data Envelopment Analysis (TFDEA) addressing these difficulties, step-by-step …


Fuzzy Cognitive Maps To Implement Corporate Social Responsibility In Product Planning: A Novel Approach, Richard Sperry, Antonie J. Jetter Jan 2012

Fuzzy Cognitive Maps To Implement Corporate Social Responsibility In Product Planning: A Novel Approach, Richard Sperry, Antonie J. Jetter

Engineering and Technology Management Faculty Publications and Presentations

Product development can support proactive CSR strategies by changing product features, materials, and processes in order to reduce or even eliminate negative environmental and social impacts. However, the CSR literature provides little practical guidance for new product development, but promotes general principles for responding to environmental and social issues. One of these guiding principles is the concept of stakeholder engagement, but to date, few practical approaches for integrating stakeholder views and needs into product development exist. To address this gap, the paper discusses the use of Fuzzy Cognitive Map Modeling. The method, which has been applied in participatory stakeholder studies …


Ultrasonic Wave Propagation Assessment Of Native Cartilage Explants And Hydrogel Scaffolds For Tissue Engineering, Sean S. Kohles, Shelley S. Mason, Anya P. Adams, Robert J. Berg, Jessica Blank, Fay Gibson, Johnathan Righetti, Lesha S. Washington, Asit K. Saha Jan 2012

Ultrasonic Wave Propagation Assessment Of Native Cartilage Explants And Hydrogel Scaffolds For Tissue Engineering, Sean S. Kohles, Shelley S. Mason, Anya P. Adams, Robert J. Berg, Jessica Blank, Fay Gibson, Johnathan Righetti, Lesha S. Washington, Asit K. Saha

Mechanical and Materials Engineering Faculty Publications and Presentations

Non-destructive techniques characterising the mechanical properties of cells, tissues, and biomaterials provide baseline metrics for tissue engineering design. Ultrasonic wave propagation and attenuation has previously demonstrated the dynamics of extracellular matrix synthesis in chondrocyte-seeded hydrogel constructs. In this paper, we describe an ultrasonic method to analyse two of the construct elements used to engineer articular cartilage in real-time, native cartilage explants and an agarose biomaterial. Results indicated a similarity in wave propagation velocity ranges for both longitudinal (1500-1745 m/s) and transverse (350-950 m/s) waveforms. Future work will apply an acoustoelastic analysis to distinguish between the fluid and solid properties including …