Portland State University

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    34041 research outputs found

    Gen Z Loves Libraries

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    If you think that libraries are just for books and that kids today care only about digital media, then you should read a new report from the American Library Association. Related Report: Digital Public Library Ecosystem 202

    Proof of the Kresch-Tamvakis Conjecture

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    In this paper we resolve a conjecture of Kresch and Tamvakis

    A Genus in the Bacterial Phylum Aquificota appears to be endemic to Aotearoa-New Zealand

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    Allopatric speciation has been difficult to examine among microorganisms, with prior reports of endemism restricted to sub-genus level taxa. Previous microbial community analysis via 16S rRNA gene sequencing of 925 geothermal springs from the Taupō Volcanic Zone (TVZ), Aotearoa-New Zealand, revealed widespread distribution and abundance of a single bacterial genus across 686 of these ecosystems (pH 1.2-9.6 and 17.4-99.8 °C). Here, we present evidence to suggest that this genus, Venenivibrio (phylum Aquificota), is endemic to Aotearoa-New Zealand. A specific environmental niche that increases habitat isolation was identified, with maximal read abundance of Venenivibrio occurring at pH 4-6, 50-70 °C, and low oxidation-reduction potentials. This was further highlighted by genomic and culture-based analyses of the only characterised species for the genus, Venenivibrio stagnispumantis CP.B2T, which confirmed a chemolithoautotrophic metabolism dependent on hydrogen oxidation. While similarity between Venenivibrio populations illustrated that dispersal is not limited across the TVZ, extensive amplicon, metagenomic, and phylogenomic analyses of global microbial communities from DNA sequence databases indicates Venenivibrio is geographically restricted to the Aotearoa-New Zealand archipelago. We conclude that geographic isolation, complemented by physicochemical constraints, has resulted in the establishment of an endemic bacterial genus

    Shame and History

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    If history—our past, the sum of our thoughts, passions, and deeds—is so pervasive, influential, and meaningful, why then do we lose sight of it? Why do we not gain good values from it? And if it is part of our existential core, why then do we so often fail to ravel it into our deliberations? I propose that very often and to a great degree it is shame that separates us from history. Shame: garrulous, compulsive, intense, omnivorous. A shamed person pushes away the experiences that shame her, thus cutting off the past

    Implementation Profile: EGoT DERMS Server/Client System (DOE-PSU-0000922-2)

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    This implementation profile (IP) provides the scope and requirements necessary to implement a distributed energy resource management system (DERMS), which networks large numbers of DER within an energy grid of things (EGoT). This document originated as part of a U.S. DOE-funded project to develop a DERMS based on a set of rules known as the Energy Services Interface (ESI). The ESI serves as an umbrella, ensuring the information exchange between an aggregator and DER owners conforms to expectations: protect privacy, provide security, develop trustworthiness, and ensure interoperability. DERMS developers use the ESI to ensure that information exchange meets these expectations. This IP demonstrates how that was done using IEEE 2030.5 as the messaging protocol

    Non-native \u3cem\u3eRhizophora mangle\u3c/em\u3e as Sinks for Coastal Contamination on Moloka’i, Hawai’i

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    Coastal mangrove forests provide a suite of environmental services, including sequestration of anthropogenic contamination. Yet, research lags on the environmental fate and potential human health risks of mangrove-sequestered contaminants in the context of mangrove removal for development and range shifts due to climate change. To address this, we conducted a study on Moloka\u27i, Hawai\u27i, comparing microplastic and pesticide contamination in coastal compartments both at areas modified by non-native red mangroves (Rhizophora mangle) and unmodified, open coastline. Sediment, porewater, and mangrove plant tissues were collected to quantify microplastic and pesticide concentrations across ecosystem type. Average microplastics were similar between mangrove (8.89 items/kg) and non-mangrove areas (9.01 items/kg) in sediment and porewater, but mangrove roots were a substantial reservoir of microplastics (2004 items/kg). Additionally, there was a strong relationship between proximity to urban development and microplastics detected. Six pesticides were detected, most commonly the insecticide bifenthrin, found in most sediment samples (11.3 ng/g), all root samples (243.3 ng/g), and one propagule sample (8.60 ng/g). Other pesticides detected with appreciable concentrations include the neonicotinoid insecticide imidacloprid and the legacy insecticide transformation product, p,p’-DDE. The other detections, all at concentrations \u3c 1 ng/g, were p,p’-DDT, trifluralin, and permethrin. The high concentrations of bifenthrin in roots compared to lower concentrations detected in sediment suggest that mangrove roots strongly accumulate some pesticides, indicating mangrove roots as a sink for organic contaminants. Study methods could be applied to other Hawaiian Islands and other locations where mangroves have been introduced to further examine the observed trends. Additional information is needed to investigate the fate and cycling of pesticides and microplastics adhered to mangrove roots, to better inform non-native mangrove removal efforts on Moloka\u27i and elsewhere

    Energy Services Interface (DOE-PSU-0000922-1)

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    This document defines a set of rules known as the Energy Services Interface (ESI), which “establish a bi-directional, service-oriented, logical interface to support secure, trustworthy information exchange between an aggregator and distributed energy resources (DERs). These exchanges facilitate energy interactions between the DERs and the aggregator, thereby allowing the aggregator to provide grid services through dispatch of the DERs.” The ESI serves as an umbrella, ensuring the information exchange between an aggregator and DER owners conforms to expectations: protect privacy, provide security, develop trustworthiness, and ensure interoperability. DERMS developers use the ESI to ensure that information exchange meets these expectations

    Engaging with Nature and Work: associations among the built and natural environment, experiences outside, and job engagement and creativity

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    Introduction: There is substantial evidence that contact with nature is related to positive health and well-being outcomes, but extensions of this research to work-related outcomes is sparse. Some organizations are redesigning workspaces to incorporate nature and adopting nature-related policies, warranting a need for empirical studies that test the influence of nature on employee outcomes. Methods: The present mixed-methods study tests and extends the biophilic work design model to examine associations among the built and natural environment at work and home, experiences of time spent outside (i.e., amount of time outside, enjoyment of time outside, outdoor activities), and motivational work outcomes (i.e., job engagement and creativity). Objective geographic data were combined with quantitative and qualitative survey responses from working adults (N = 803). Results: Our results broadly indicate that individuals who work and live in areas with greater natural amenities (i.e., access to water, topographic variation, temperate climates) spend more time outside and enjoy time outside to a greater degree, and these experiences are in turn associated with greater engagement and creativity at work. We did not find evidence that the surrounding built environment (i.e., urbanity) at work or home was associated with outdoor experiences or work-related outcomes. Additionally, six categories of outdoor activities were identified in the qualitative analyses – leisure activities, relaxation, physical activities, social interactions, tasks and errands, and travel. Discussion: The findings from this study provide evidence that the natural environment, particularly at home, can benefit work-related outcomes via greater time and enjoyment of time outside. This study has implications for employee time use and organizational effectiveness

    Path Instabilities and Drag in the Settling of Single spheres

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    The settling behavior of individual spheres in a quiescent fluid was studied experimentally. The dynamics of the spheres was analyzed in the parameter space of particle-to-fluid density ratio (Γ) and Galileo number (Ga), with Γ ∈ (1.1,7.9) and Ga ∈ (100,340). The experimental results showed for the first time that the mean trajectory angle with the vertical exhibits a complex behavior as Ga and Γ are varied. Numerically predicted regimes such as Vertical Periodic for low Γ values, and Planar Rotating for high Γ values were validated. In particular, for the denser spheres, a clear transition from planar to non-planar trajectories was observed, accompanied by the emergence of semi-helical trajectories corresponding to the Planar Rotating Regime. The spectra of trajectory oscillations were also quantified as a function of Ga, confirming the existence of oblique oscillating regimes at both low and high frequencies. The amplitudes of the perpendicular velocities in these regimes were also quantified and compared with numerical simulations in the literature. The terminal velocity and drag of the spheres were found to depend on the particle-to-fluid density ratio, and correlations between the drag coefficient and particle Reynolds number (Rep) as a function of Ga were established, allowing for the estimation of drag and settling velocity using Ga, a control parameter, rather than the response parameter Rep

    Product Specification: Distributed Trust Model System (DOE-PSU-0000922-4)

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    A Distributed Trust Model (DTM) System is a supervisory component within an energy grid of things. The role of a DTM System is to implement the trust aspects of an energy services interface. The DTM System augments existing security measures by monitoring the communication between the various EGoT System actors and quantifying metrics of trust of each actor


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