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Evaluating DIY Air Cleaner Variability and Potential for Post-Construction Emission of Aromatic Vocs During Wildfire Events
Get PDFWhile do-it-yourself (DIY) air cleaners such as the Corsi-Rosenthal Box (CR Box) are an increasingly popular choice for low-cost, accessible air cleaning during a wildfire event, construction and performance variability remains a concern. Using the same set of instructions, materials, and location of assembly, seven CR Boxes are constructed by individuals with no prior DIY air cleaner experience and clean air delivery rates (CADRs) are experimentally determined for each of the devices. Against a challenge aerosol consisting of fresh smoke generated via pine needle combustion, average number-based, PM2.5 CR Box CADRs range from 313–396 m3/h (relative standard deviation = 7.6 %). Over this modest range of observed variability, constructed units outperform many higher-cost commercial air cleaners. A review of the literature demonstrates that across studies, substantial CADR variability is observed (285–1448 m3/h); differences in materials (including filter type) used during air cleaner construction, challenge aerosols tested, and evaluation protocol are major contributors to variability. To evaluate the potential for exposure to aromatic volatile organic compounds (VOCs) from CR Box materials, we place three devices in a large chamber for 24–72 hours immediately following construction. Toluene and C8 aromatics (ethylbenzene and xylenes) are emitted at 2289 and 89 μg/h, respectively, with emission rates decreasing by 94 % and 82 % after 12 hours. Using experimentally determined PM2.5 CADRs and VOC emission rates, a hypothetical wildfire event impacting the bedroom of a home is modeled at four outdoor air exchange rates (AERs) to assess tradeoffs between building airtightness, particle removal effectiveness, and VOC off-gassing from a newly built CR Box. PM2.5 effectiveness ranges from 0.88 to 0.95, depending on AER (0.1–1 h−1). While modeled maximum VOC concentrations remain orders of magnitude below short-term permissible exposure limits at all AERs considered, modeled and observed VOC dynamics imply that an off-gassing period of ∼6–12 hours would avoid episodic emission of VOCs at rates that may cause accumulation in excess of the lower-limit of toluene odor threshold estimates
How Does Herbicide Resistance Change Farmer’s Weed Management Decisions? Evidence from the Roundup Ready Experiment
Get PDFAdoption of diverse weed management practices is viewed as essential for slowing the spread of herbicide-resistant (HR) weeds. Yet, adoption of diverse tactics has remained low, while there has been explosive growth of resistant weeds. This study analyzes U.S.-farm-level data to identify factors affecting adoption of diverse weed management practices. This study uses directed acyclic graphs (DAGs) to consider how practice adoption is influenced by different causal pathways between farmer and farm characteristics and farmer awareness of and concern over HR weeds. This study then uses multiple regression analysis to estimate the direct and indirect pathways that influence practice adoption. Respondents relied more heavily on herbicide-based weed control methods than on mechanical or cultural methods. Concern over herbicide resistance increased the number of practices farmers adopted and the percentage of acres where farmers implemented these practices. Practice adoption was negatively associated with increasing levels of farmer risk aversion. Technological optimism—belief that new herbicides would soon be developed to counter HR weeds—discouraged diverse herbicide use practices that combat resistance, but encouraged use of some non-chemical weed control methods. Perceived weed dispersal externalities (from weed mobility) led to more diverse weed management, running counter to hypotheses that greater mobility reduces incentives for individual resistance management
Automation of Productive Machinery. Bases for an Innovative Business Model
Get PDFNowadays, some laboratories perform elastic properties tests for concrete or rock cores using equipment manufactured 50 years ago. The original data collection procedure uses analog and manual recordings, which can cause inaccuracies in the measurements taken during these trials The process is tedious and updated since each trial\u27s measurement data is recorded manually. In this context, this study systematizes the process and proposes an automated data acquisition and recording system for this type of equipment, followed by a case study presenting a rock compression test
Oregon State Rank Assessment for Wolverine (Gulo gulo)
Get PDFOregon state conservation status assessment for wolverine (Gulo gulo) using NatureServe methodology, 2024
From the Ocean to Our Kitchen Table: Anthropogenic Particles in the Edible Tissue of U.S.. West Coast Seafood Species
Get PDFMicroplastics (MPs) and other anthropogenic particles (APs) are pervasive environmental contaminants found throughout marine and aquatic environments. We quantified APs in the edible tissue of black rockfish, lingcod, Chinook salmon, Pacific herring, Pacific lamprey, and pink shrimp, comparing AP burdens across trophic levels and between vessel-retrieved and retail-purchased individuals. Edible tissue was digested and analyzed under a microscope, and a subset of suspected APs was identified using spectroscopy (μFTIR). Anthropogenic particles were found in 180 of 182 individuals. Finfish contained 0.02–1.08 AP/g of muscle tissue. In pink shrimp (Pandalus jordani), the average AP/g was 10.68 for vessel-retrieved and 7.63 for retail-purchased samples; however, APs/g of tissue were higher in retail-purchased lingcod than vessel-retrieved lingcod, signaling possible added contamination during processing from ocean to market. Riverine young adult Pacific lamprey contained higher concentrations of APs (1 AP/g ±0.59) than ocean phase adults (0.60 AP/ g ±0.80 and p = 0.08). Particle types identified were 82% fibers, 17% fragments, and 0.66% films. These findings suggest a need for further research into technologies and strategies to reduce microfiber pollution entering the environment
Why Is This Book (Elements and Relations) Different From All Other Books?
No full textThis talk is a short description of the book, Elements and Relations, given in an informal setting -- a book party at home -- to a small gathering of family, friends, and colleagues.
A more formal description of the book from the publisher\u27s (Springer) site:
This book develops the core proposition that systems theory is an attempt to construct an “exact and scientific metaphysics,” a system of general ideas central to science that can be expressed mathematically. Collectively, these ideas would constitute a non-reductionist “theory of everything” unlike what is being sought in physics. Inherently transdisciplinary, systems theory offers ideas and methods that are relevant to all of the sciences and also to professional fields such as systems engineering, public policy, business, and social work. To demonstrate the generality and importance of the systems project, the book structures its content in three parts: Essay, Notes, and Commentary. The Essay section is a short distillation of systems ideas that illuminate the problems that many types of systems face. Commentary explains systems thinking, its value, and its relation to mainstream scientific knowledge. It shows how systems ideas revise our understanding of science and how they impact our views on religion, politics, and history. Finally, Notes contains all the mathematics in the book, as well as scientific, philosophical, and poetic content that is accessible to readers without a strong mathematical background
University Studies Annual Assessment 2023-2024
Get PDFAnnual in-depth examination and assessment of Portland State University\u27s general education model, the University Studies Program. The tools and methods used to assess student learning are faculty driven and developed
Coordinated Population Forecast for Clackamas County, its Urban Growth Boundaries (UGB), and Area Outside UGBs 2024-2074
Get PDFThis report for population forecasts for Clackamas County was made in compliance with Oregon House Bill 2253 relating to population forecasts for land use planning. Portland State University Population Research Center is tasked with creating population projections for all Oregon counties except Multnomah, Clackamas, and Washington as well as population forecasts for all Urban Growth Boundaries (UGBs), except for the Metro area UGB. These population forecasts are generated using standardized demographic methods with input and feedback from county, city, and other local stakeholders
Experimental and Modeled Assessment of Interventions to Reduce PM2.5 in a Residence during aWildfire Event
Get PDFIncreasingly large and frequent wildfires affect air quality even indoors by emitting and dispersing fine/ultrafine particulate matter known to pose health risks to residents. With this health threat, we are working to help the building science community develop simplified tools that may be used to estimate impacts to large numbers of homes based on high-level housing characteristics. In addition to reviewing literature sources, we performed an experiment to evaluate interventions to mitigate degraded indoor air quality. We instrumented one residence for one week during an extreme wildfire event in the Pacific Northwest. Outdoor ambient concentrations of PM2.5 reached historic levels, sustained at over 200 μg/m3 for multiple days. Outdoor and indoor PM2.5 were monitored, and data regarding building characteristics, infiltration, and mechanical system operation were gathered to be consistent with the type of information commonly known for residential energy models. Two conditions were studied: a high-capture minimum efficiency rated value (MERV 13) filter integrated into a central forced air (CFA) system, and a CFA with MERV 13 filtration operating with a portable air cleaner (PAC). With intermittent CFA operation and no PAC, indoor corrected concentrations of PM2.5 reached 280 μg/m3, and indoor/outdoor (I/O) ratios reached a mean of 0.55. The measured I/O ratio was reduced to a mean of 0.22 when both intermittent CFA and the PAC were in operation. Data gathered from the test home were used in a modeling exercise to assess expected I/O ratios from both interventions. The mean modeled I/O ratio for the CFA with an MERV 13 filter was 0.48, and 0.28 when the PAC was added. The model overpredicted the MERV 13 performance and underpredicted the CFA with an MERV 13 filter plus a PAC, though both conditions were predicted within 0.15 standard deviation. The results illustrate the ways that models can be used to estimate indoor PM2.5 concentrations in residences during extreme wildfire smoke events
From early Curiosity to space wide web: The emergence of the small satellite innovation ecosystem
Get PDFInnovation ecosystems have gained significant scholarly and managerial attention. Much of the literature focuses on established ecosystems, and the limited research that examines ecosystem emergence does not dig deeper into the dynamics and challenges during the process of emergence. With a focus on the transition from birth to growth of an ecosystem, this paper fills this important gap by systematically examining how a nascent ecosystem develops into a thriving one. Employing a conceptualized composition approach, we conduct an in-depth qualitative study on the emergence of the modern small satellite ecosystem from 1981 to 2017. Our case analysis demonstrates a dynamic process through which a seed innovation gradually grows into a thriving ecosystem without a centralized sponsor. We explicate how tensions arise within an evolving ecosystem and how forces hindering specialization delay the emergence process. We then develop a process model of ecosystem emergence to conceptualize how actors gradually become specialized, how their specialization decisions coevolve with the ecosystem value proposition, and how tensions get resolved through a complex and iterative process. We contribute to the literature by advancing an evolutionary view of ecosystem emergence with an in-depth analysis of the transition from birth to growth of an ecosystem