18 research outputs found

    Creating a STEM Collaborative Learning Center: A Case Study

    Get PDF
    What happens when campus units come together to create both a shared physical space, and a shared mission space? This case study highlights a unique cross-campus partnership between the UCLA Science Libraries and two academic support programs to create a STEM Collaborative Learning Center. This space serves to help decrease achievement gaps in STEM courses through peer-to-peer active learning and collaborative study. The results of the collaboration have helped to promote student success, increase the value and visibility of the library, inform space design decisions, and innovate new ways campus partners can work together to achieve shared goals

    Environmental Life Cycle Assessment

    Get PDF
    Environmental Life Cycle Assessment is a pivotal guide to identifying environmental problems and reducing related impacts for companies and organizations in need of life cycle assessment (LCA). LCA, a unique sustainability tool, provides a framework that addresses a growing demand for practical technological solutions. Detailing each phase of the LCA methodology, this textbook covers the historical development of LCA, presents the general principles and characteristics of LCA, and outlines the corresponding standards for good practice determined by the International Organization for Standardization. It also explains how to identify the critical aspects of an LCA, provides detailed examples of LCA analysis and applications, and includes illustrated problems and solutions with concrete examples from water management, electronics, packaging, automotive, and other industries. In addition, readers will learn how to: Use consistent criteria to realize and evaluate an LCA independently of individual interests Understand the LCA methodology and become familiar with existing databases and methods based on the latest results of international research Analyze and critique a completed LCA Apply LCA methodology to simple case studies Geared toward graduate and undergraduate students studying environmental science and industrial ecology, as well as practicing environmental engineers, and sustainability professionals who want to teach themselves LCA good practices, Environmental Life Cycle Assessment demonstrates how to conduct environmental assessments for products throughout their life cycles. It presents existing methods and recent developments in the growing field of LCA and systematically covers goal and system definition, life cycle inventory, life cycle impact assessment, and interpretation

    Life Cycle Impact Assessment of chemicals: relevance and feasibility of spatial differentiation for ecotoxicity and human toxicity impact assessment

    Get PDF
    Environmental implications of the whole supply-chain of products, both goods and services, their use, and waste management, i.e. their entire life cycle from “cradle to grave” have to be considered to achieve more sustainable production and consumption patterns. Historically, Life Cycle Management (LCM), Assessment (LCA) and the related Impact Assessment (LCIA) methods have mostly relied on site-generic, not spatially resolved, models. In recent years, the relevance of accounting for spatial differentiation has been increasingly discussed in the context of LCA. Thus, several spatially distributed fate and transport models of chemicals, i.e. models allowing spatially explicit assessment of contaminants from a given spatial distribution of emission, were developed. The present paper presents an overview of these models, and discusses the relevance and feasibility of spatial differentiation of LCIA results in a Life Cycle Management perspective. Example of application of the models for human and ecotoxicity impact categories at various scales are presented.JRC.H.8-Sustainability Assessmen

    Spatial analysis of toxic emissions in LCA: A sub-continental nested USEtox model with freshwater archetypes

    Get PDF
    This paper develops continent-specific factors for the USEtox model and analyses the accuracy of different model architectures, spatial scales and archetypes in evaluating toxic impacts, with a focus on freshwater pathways. Inter-continental variation is analysed by comparing chemical fate and intake fractions between sub-continental zones of two life cycle impact assessment models: (1) the nested USEtox model parameterized with sub-continental zones and (2) the spatially differentiated IMPACTWorld model with 17 interconnected sub-continental regions. Substance residence time in water varies by up to two orders of magnitude among the 17 zones assessed with IMPACTWorld and USEtox, and intake fraction varies by up to three orders of magnitude. Despite this variation, the nested USEtox model succeeds in mimicking the results of the spatially differentiated model, with the exception of very persistent volatile pollutants that can be transported to polar regions. Intra- continental variation is analysed by comparing fate and intake fractions modelled with the a-spatial (one box) IMPACT Europe continental model vs. the spatially differentiated version of the same model. Results show that the one box model might overestimate chemical fate and characterisation factors for freshwater eco-toxicity of persistent pollutants by up to three orders of magnitude for point source emissions. Subdividing Europe into three archetypes, based on freshwater residence time (how long it takes water to reach the sea), improves the prediction of fate and intake fractions for point source emissions, bringing them within a factor five compared to the spatial model. We demonstrated that a sub-continental nested model such as USEtox, with continent-specific parameterization complemented with freshwater archetypes, can thus represent inter- and intra-continental spatial variations, whilst minimizing model complexity. (C) 2014 Elsevier Ltd. All rights reserved

    Education for a Future in Crisis: Developing a Humanities-Informed STEM Curriculum

    Full text link
    In the popular imagination, science and technology are often seen as fields of knowledge production critical to social progress and a cooperative future. This optimistic portrayal of technological advancement also features prominently in internal discourses amongst scientists, industry leaders, and STEM students alike. Yet, an overwhelming body of research, investigation, and first-person accounts highlight the varying ways modern science, technology, and engineering industries contribute to the degradation of our changing environments and exploit and harm global low-income and marginalized populations. By and large, siloed higher-education STEM curricula provide inadequate opportunities for undergraduate and graduate students to critically analyze the historical and epistemological foundations of scientific knowledge production and even fewer tools to engage with and respond to modern community-based cases. Here, we describe the development of a humanities- and social sciences-informed curriculum designed to address the theory, content, and skill-based needs of traditional STEM students considering technoscientific careers. In essence, this course is designed to foster behavior change, de-center dominant ways of knowing in the sciences, and bolster self-reflection and critical-thinking skills to equip the developing STEM workforce with a more nuanced and accurate understanding of the social, political, and economic role of science and technology. This curriculum has the potential to empower STEM-educated professionals to contribute to a more promising, inclusive future. Our framework foregrounds key insights from science and technology studies, Black and Native feminisms, queer theory, and disability studies, alongside real-world case studies using critical pedagogies.Comment: 25 pages, 1 figure, 4 table

    The Variability of Seyfert 1.8 and 1.9 Galaxies at 1.6 microns

    Get PDF
    We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Hubble Space Telescope (HST) at 1.6 microns. We find that unresolved nuclear emission from 9 of 14 nuclei varies at the level of 10-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are non-stellar and associated with the central pc of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys, however high angular resolution infrared observations will provide a way to measure time delays in these galaxies.Comment: accepted by ApJLetters (emulateapj latex

    The Multitude of Unresolved Continuum Sources at 1.6 microns in Hubble Space Telescope images of Seyfert Galaxies

    Get PDF
    We examine 112 Seyfert galaxies observed by the Hubble Space Telescope (HST) at 1.6 microns. We find that ~50% of the Seyfert 2.0 galaxies which are part of the Revised Shapeley-Ames (RSA) Catalog or the CfA redshift sample contain unresolved continuum sources at 1.6 microns. All but a couple of the Seyfert 1.0-1.9 galaxies display unresolved continuum sources. The unresolved sources have fluxes of order a mJy, near-infrared luminosities of order 10^41 erg/s and absolute magnitudes M_H ~-16. Comparison non-Seyfert galaxies from the RSA Catalog display significantly fewer (~20%), somewhat lower luminosity nuclear sources, which could be due to compact star clusters. We find that the luminosities of the unresolved Seyfert 1.0-1.9 sources at 1.6 microns are correlated with [OIII] 5007A and hard X-ray luminosities, implying that these sources are non-stellar. Assuming a spectral energy distribution similar to that of a Seyfert 2 galaxy, we estimate that a few percent of local spiral galaxies contain black holes emitting as Seyferts at a moderate fraction, 10^-1 to 10^-4, of their Eddington luminosities. With increasing Seyfert type the fraction of unresolved sources detected at 1.6 microns and the ratio of 1.6 microns to [OIII] fluxes tend to decrease. These trends are consistent with the unification model for Seyfert 1 and 2 galaxies.Comment: accepted by Ap

    IMPACT World+: a globally regionalized life cycle impact assessment method

    Get PDF
    Purpose This paper addresses the need for a globally regionalized method for life cycle impact assessment (LCIA), integrating multiple state-of-the-art developments as well as damages on water and carbon areas of concern within a consistent LCIA framework. This method, named IMPACT World+, is the update of the IMPACT 2002+, LUCAS, and EDIP methods. This paper first presents the IMPACT World+ novelties and results and then analyzes the spatial variability for each regionalized impact category. Methods With IMPACT World+, we propose a midpoint-damage framework with four distinct complementary viewpoints to present an LCIA profile: (1) midpoint impacts, (2) damage impacts, (3) damages on human health, ecosystem quality, and resources & ecosystem service areas of protection, and (4) damages on water and carbon areas of concerns. Most of the regional impact categories have been spatially resolved and all the long-term impact categories have been subdivided between shorterterm damages (over the 100 years after the emission) and long-term damages. The IMPACT World+ method integrates developments in the following categories, all structured according to fate (or competition/scarcity), exposure, exposure response, and severity: (a) Complementary to the global warming potential (GWP100), the IPCC Global Temperature Potentials (GTP100) are used as a proxy for climate change long-term impacts at midpoint. At damage level, shorter-term damages (over the first 100 years after emission) are also differentiated from long-term damages. (b) Marine acidification impact is based on the same fate model as climate change, combined with the H+ concentration affecting 50% of the exposed species. (c) For mineral resources depletion impact, the material competition scarcity index is applied as a midpoint indicator. (d) Terrestrial and freshwater acidification impact assessment combines, at a resolution of 2° × 2.5° (latitude × longitude), global atmospheric source-deposition relationships with soil and water ecosystems’sensitivity. (e) Freshwater eutrophication impact is spatially assessed at a resolution grid of 0.5° × 0.5°, based on a global hydrological dataset. (f) Ecotoxicity and human toxicity impact are based on the parameterized version of USEtox for continents. We consider indoor emissions and differentiate the impacts of metals and persistent organic pollutants for the first 100 years from longer-term impacts. (g) Impacts on human health related to particulate matter formation are modeled using the USEtox regional archetypes to calculate intake fractions and epidemiologically derived exposure response factors. (h) Water consumption impacts are modeled using the consensus-based scarcity indicator AWARE as a proxy midpoint, whereas damages account for competition and adaptation capacity. (i) Impacts on ecosystem quality from land transformation and occupation are empirically characterized at the biome level. Results and discussion We analyze the magnitude of global potential damages for each impact indicator, based on an estimation of the total annual anthropogenic emissions and extractions at the global scale (i.e., Bdoing the LCA of the world^). Similarly with ReCiPe and IMPACT 2002+, IMPACT World+ finds that (a) climate change and impacts of particulate matter formation have a dominant contribution to global human health impacts whereas ionizing radiation, ozone layer depletion, and photochemical oxidant formation have a low contribution and (b) climate change and land use have a dominant contribution to global ecosystem quality impact. (c) New impact indicators introduced in IMPACT World+ and not considered in ReCiPe or IMPACT 2002+, in particular water consumption impacts on human health and the long-term impacts of marine acidification on ecosystem quality, are significant contributors to the overall global potential damage. According to the areas of concern version of IMPACT World+ applied to the total annual world emissions and extractions, damages on the water area of concern, carbon area of concern, and the remaining damages (not considered in those two areas of concern) are of the same order of magnitude, highlighting the need to consider all the impact categories. The spatial variability of human health impacts related to exposure to toxic substances and particulate matter is well reflected by using outdoor rural, outdoor urban, and indoor environment archetypes. For Bhuman toxicity cancer^ impact of substances emitted to continental air, the variability between continents is of two orders of magnitude, which is substantially lower than the 13 orders of magnitude total variability across substances. For impacts of water consumption on human health, the spatial variability across extraction locations is substantially higher than the variations between different water qualities. For regionalized impact categories affecting ecosystem quality (acidification, eutrophication, and land use), the characterization factors of half of the regions (25th to 75th percentiles) are within one to two orders of magnitude and the 95th percentile within three to four orders of magnitude, which is higher than the variability between substances, highlighting the relevance of regionalizing. Conclusions IMPACT World+ provides characterization factors within a consistent impact assessment framework for all regionalized impacts at four complementary resolutions: global default, continental, country, and native (i.e., original and non-aggregated) resolutions. IMPACT World+ enables the practitioner to parsimoniously account for spatial variability and to identify the elementary flows to be regionalized in priority to increase the discriminating power of LCA

    Multi-Continental Multimedia Model of Pollutant Intake and Application to Impacts of Global Emissions and Globally Traded Goods.

    Full text link
    Decision-makers seeking to more comprehensively assess and mitigate the environmental health impacts of products and chemicals require a tool to quantify the impacts associated with global emissions, global supply chains, and global food trade. To be effective, this tool needs to include pollutant fate in multiple environmental media, cover multiple exposure pathways accounting for trade of pollutant through food, and account for high exposure intensity areas and transboundary transport, all while minimizing computational needs. This thesis thus develops IMPACTWorld, the adaptation of a multimedia model to a global scale that accounts for trans-boundary transport and urban exposure. I use IMPACTWorld to calculate the regional intakes of ingestion-dominant polychlorinated biphenyl-118 (PCB-118) and inhalation-dominant fine particulate matter (PM2.5). I then analyze spatial differences in the intake fraction (iF), which is the fractional population intake of each regional emission. PM2.5 iFs are dominated by local urban exposure, whereas transboundary transport of the more persistent PCB-118 leads to substantial portions of the pollutant ingested outside the region of emission. This model helps to further bridge the fields of life cycle assessment and risk assessment by calculating impacts from both the emitter and receiver perspectives. I then add a component to IMPACTWorld that accounts for pollutant economic fate through trade of food and feed. By applying the expanded model to two pollutants that bioconcentrate differently in food and have different global emissions patterns, I find that food exports can substantially alter the absolute pollutant regional intake Finally, IMPACTWorld is combined with an economic model of global trade to yield the first spatially-explicit integrated model describing the full causal chain from consumption to impacts. The results for PM2.5 suggest that the majority of the PM-related health impacts induced by consumption in developed countries occur outside their borders, mainly in Asia. In summary, this thesis reveals new insights into impacts associated with environmental pollutant transport, pollutant transport through food, and “virtual” export of pollution through global trade. It thus provides a motivation and foundation for further exploration of the significance and contribution of these impact mechanisms in the assessment of a product or emission.Ph.D.Applied PhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/84578/1/shaked_1.pd
    corecore