Engineering Commons^™

Anomalous Lattice Thermal Conductivity Driven By All-Scale Electron-Phonon Scattering In Bulk Semiconductors, Z. Z. Zhou, Y. C. Yan, X. L. Yang, Yi Xia, G. Y. Wang, X. Lu, X. Y. Zhou

Mechanical and Materials Engineering Faculty Publications and Presentations

Electron-phonon coupling (EPC) has been broadly considered to govern the charge transport in solids, whereas its effect on thermal conductivity, especially for semiconductors at ambient temperatures, is a widely debated issue in condensed-matter physics. Employing state-of-the-art first-principles calculations to quantify all the possible scattering factors, we show the dominant role of EPC in phonon transport of n-doped GaSb, which yields an unprecedented reduction of lattice thermal conductivity and triggers anomalous temperature-independent behavior. The significant EPC impact hinges on the joint effect of multiple conduction pockets, large EPC strength, and bunched heat-carrying acoustic branches, provoking strong electron-phonon scattering to surpass the …

Additive Manufacturing Design For Affordable Housing Development, Courtney Wright, Lani Nguyen, Jordan Wearing

Engineering and Technology Management Student Projects

Recently, there has been an increasing lack of affordable homes. Since rent, prices, gas, and other utilities continue to rise, wages (especially for low-income individuals) have stayed constant throughout the country. This has caused numerous citizens to not be able to afford a home or even pay rent. This situation has caused a large surge in the homeless community, and it is estimated that approximately 37,500 individuals per day are in need of housing throughout the Pacific Northwest as of January 2020. [1] In response to this issue, our team has provided a goal to provide trendy and affordable homes …

A Review Of In-Situ And Remote Sensing Technologies To Monitor Water And Sanitation Interventions, Luis Andres, Kwasi Boateng, Christian Borja-Vega, Evan Thomas

Engineering and Technology Management Faculty Publications and Presentations

The United Nations Sustainable Development Goals (SDGs), announced in September 2015, present a vision of achieving a higher level of human health and well-being worldwide by the year 2030. The SDG targets specific to water and sanitation call for more detailed monitoring and response to understand the coverage and quality of safely managed sources. It is hoped that improved monitoring of water and sanitation interventions will reveal more cost-effective and efficient ways of meeting the SDGs. In this paper, we review the landscape of approaches that can be used to support and improve on the water and sanitation targets SDG …

Decision Support System For The Design And Planning Of Low-Impact Development Practices: The Case Of Seoul, Jae-Yeol Song, Eun-Sung Chung, Soo Hyun Kim

Civil and Environmental Engineering Faculty Publications and Presentations

This study presented the conceptual framework of the water-management analysis module (WMAM) to derive effective physical specifications for the design and planning of low-impact development (LID) practices using the storm-water management model (SWMM). This decision-support system can be used for six LID types and has the following key capabilities: determining relevant LID design parameters within the SWMM that critically influence the hydrological cycle components using a simple sensitivity analysis and determining the best hydrological values for LID planning specification. This study analyzed a highly urbanized university campus as a case study to determine the design and planning specifications for an …

Study Design Of A Cluster-Randomized Controlled Trial To Evaluate A Large-Scale Distribution Of Cook Stoves And Water Filters In Western Province, Rwanda, Corey L. Nagel, Miles Kirby, Laura D. Zambrano, Ghislaine Rosa, Christina K. Barstow, Evan A. Thomas, Thomas Clasen

Mechanical and Materials Engineering Faculty Publications and Presentations

Background: In Rwanda, pneumonia and diarrhea are the first and second leading causes of death, respectively, among children under five. Household air pollution (HAP) resultant from cooking indoors with biomass fuels on traditional stoves is a significant risk factor for pneumonia, while consumption of contaminated drinking water is a primary cause of diarrheal disease. To date, there have been no largescale effectiveness trials of programmatic efforts to provide either improved cookstoves or household water filters at scale in a low-income country. In this paper we describe the design of a clusterrandomized trial to evaluate the impact of a national-level program …

Process Evaluation And Assessment Of Use Of A Large Scale Water Filter And Cookstove Program In Rwanda, Christina K. Barstow, Corey Nagel, Thomas Clasen, Evan A. Thomas

OHSU-PSU School of Public Health Faculty Publications and Presentations

Background: In an effort to reduce the disease burden in rural Rwanda, decrease poverty associated with expenditures for fuel, and minimize the environmental impact on forests and greenhouse gases from inefficient combustion of biomass, the Rwanda Ministry of Health (MOH) partnered with DelAgua Health (DelAgua), a private social enterprise, to distribute and promote the use of improved cookstoves and advanced water filters to the poorest quarter of households (Ubudehe 1 and 2) nationally, beginning in Western Province under a program branded Tubeho Neza (“Live Well”). The project is privately financed and earns revenue from carbon credits under the United Nations …

Sustainable Drainage Systems: Helping People Live With Water, Glyn Everett, Jessica Lamond, Anita T. Morzillo, Faith Ka Shun Chan, Annie Marissa Matsler

Urban Studies and Planning Faculty Publications and Presentations

Sustainable drainage systems or ‘Suds’ are increasingly accepted as an effective means of ‘making space for water’, adapting to possible climate change and helping communities become more flood and drought resilient. This study explores potential shifts in perception and attitude through Suds installation, development and habituation. Attitudes and awareness in communities in the USA and UK, where Suds have been in place for some time, were compared and contrasted, examining any evolution of beliefs and practices and wider community resilience. The principal finding was that there existed a lack of understanding about the existence and function of Suds. The paper …

Ozone Reaction With Interior Building Materials: Influence Of Diurnal Ozone Variation, Temperature And Humidity, Donghyun Rim, Elliott T. Gall, Randy L. Maddalena, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect health and comfort. Reactive uptake of ozone has been characterized for many building materials; however, scant information is available on how diurnal variation of ambient ozone influences ozone reaction with indoor surfaces. The primary objective of this study is to investigate ozone-surface reactions in response to a diurnally varying ozone exposure for three common building materials: ceiling tile, painted drywall, and carpet tile. A secondary objective is to examine the effects of air …

Research On Coupled Human And Natural Systems (Chans): Approach, Challenges, And Strategies, Marina Alberti, Heidi Asbjornsen, Lawrence A. Baker, Nicholas Brozović, Laurie E. Drinkwater, Scott A. Drzyzga, Claire A. Jantz, José Fragoso, Daniel S. Holland, Timothy A. Kohler, Jianguo Liu, William J. Mcconnell, Herbert D. G. Maschner, James D. A. Millington, Michael Monticino, Guillermo Podestá, Robert Gilmore Pontius Jr., Charles L. Redman, Nicholas J. Reo, David J. Sailor, Gerald Urquhart

Mechanical and Materials Engineering Faculty Publications and Presentations

Understanding the complexity of human–nature interactions is central to the quest for both human well-being and global sustainability. To build an understanding of these interactions, scientists, planners, resource managers, policy makers, and communities increasingly are collaborating across wide-ranging disciplines and knowledge domains. Scientists and others are generating new integrated knowledge on top of their requisite specialized knowledge to understand complex systems in order to solve pressing environmental and social problems (e.g., Carpenter et al. 2009). One approach to this sort of integration, bringing together detailed knowledge of various disciplines (e.g., social, economic, biological, and geophysical), has become known as the …

Presentation: Proving Sustainability: The International Development Monitoring Initiative, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Presentation detailing the activities and products of the Sustainable Water, Energy and Environmental Technologies Laboratory at Portland State University (SWEETLab). The lab also works to develop standards to help evaluate and compare projects and outcomes around the world. Water treatment and sanitation practices, as well as newly designed cookstoves, are highlighted.

A Model For Sustainable Humanitarian Engineering Projects, Evan A. Thomas, Bernard Amadei, Robyn Sandekian

Mechanical and Materials Engineering Faculty Publications and Presentations

The engineering profession should embrace a new mission statement?to contribute to the building of a more sustainable, stable, and equitable world. Recently, engineering students and professionals in the United States have shown strong interest in directly addressing the needs of developing communities worldwide. That interest has taken the form of short-and medium-term international trips through Engineers Without Borders?USA and similar organizations. There are also several instances where this kind of outreach work has been integrated into engineering education at various US institutions such as the University of Colorado at Boulder. This paper addresses the challenges and opportunities associated with balancing …

The Urban Heat Island Mitigation Impact Screening Tool (Mist), David J. Sailor, Nikolaas Dietsch

Mechanical and Materials Engineering Faculty Publications and Presentations

A web-based software tool has been developed to assist urban planners and air quality management officials in assessing the potential of urban heat island mitigation strategies to affect the urban climate, air quality, and energy consumption within their cities. The user of the tool can select from over 170 US cities for which to conduct the analysis, and can specify city-wide changes in surface reflectivity and/or vegetative cover. The Mitigation Impact Screening Tool (MIST) then extrapolates results from a suite of simulations for 20 cities to estimate air temperature changes associated with the specified changes in surface characteristics for the …

A Market-Based Framework For Semiconductor Industry Growth The Reduced Ecological Impart, Dawood Sulieman Abugharbieh

Dissertations and Theses

Reducing the ecological impact of industrial development is an emerging trend that affords companies the opportunity to gain competitive advantage. Semiconductor manufacturers have specifically identified ecological impact as a strategic variable that presents a long-term challenge. The socioeconomic nature of the ecological impact construct increases decision-making complexity in a manner that is not typical in business-to-business contexts. To account for social and economic aspects, this study utilized a cognitive structure-based model. Such models have been successfully utilized in consumer and industrial markets as adaptable frameworks that can encompass social and economic constructs.

This research focuses on linking two ecological constructs …