5,457 research outputs found

    A comprehensive and absolute corporate sustainability assessment and enhanced input output life cycle assessment

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    Stresses due to economic activity are threatening to exceed environmental and societal limits with the potential to jeopardize local communities and create global crises. This research proposes new methodologies and analytic techniques to comprehensively assess corporate sustainability and enhance the efficiency of estimating environmental and social impacts with Input Output Life Cycle Assessment (IOLCA). Sustainability assessments and management require consideration of both social and environmental impacts as outflows of economic activity. There are a number of assessment tools available to gain insight into environmental and social impacts; but in most cases, these approaches lack essential components for a comprehensive and absolute sustainability assessment. This dissertation proposes a new quantitative method for assessing sustainability across all the interrelationships within multiple domains of sustainability—economic, social, environmental, and potentially others. The comprehensive sustainability target method (CSTM) is a novel extension to an existing environmental burden sustainability technique. CSTM applies the science-based targets and concept of absolute sustainability to social burdensome and beneficial impacts, environmental beneficial impacts, and the interdependencies between the sustainability domains. CSTM is contrasted with an example of the relative assessments that appear in many sustainability disclosures. In addition to science-based targets for environmental burdens, companies should attempt to meet science-based targets for social and beneficial impacts. Another area of research is focused on IOLCA, a widely used method of estimating environmental impacts based on economic sector level data and analysis. These IOLCA models rely on sector averages and require practitioners to combine impact estimation models to describe specific companies or “custom products”. This research presents a novel extension to environmental input-output modeling that increases the usability and responsiveness of the technique to perform custom product-specific assessments. This enhancement models direct impacts from emissions (and other stressors) attributable to direct spending on commodities across the economy that cause those impacts. The proposed extension directly calculates the internal impact (II); hence, the model implemented is referred to as the IOLCA-II. The IOLCA-II extension directly produces impact estimates in the categories typically used to manage and report greenhouse gas (GHG) emissions: Scope 1, Scope 2, and Scope 3. In addition to the IOLCA-II enhancement for environmental assessment, selected social impacts are incorporated into the extended model to permit social impact estimation. IOLCA-II impacts are estimated for two scenarios: first, a solar energy application at a university; and second, driverless operation of a long-haul trucking company. The baseline and scenarios are modeled using IOLCA-II and compared to explore the impacts and consequences of the proposed scenarios. These case studies reveal the advantages of using the new methodology and the efficiency of the input-output model results compared to conventional IOLCA hybrid/custom product assessment

    Does measurement technique explain the mismatch between European head size and WHO charts?

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    Objective To test whether different measuring techniques produce systematic differences in head size that could explain the large head circumferences found in Northern European children compared with the WHO standard. Design: Cross-sectional observational study. Setting: Scotland, UK. Patients: Study 1: 68 healthy children aged 0.4–18 months from mother and baby groups and a medical students teaching session. Study 2: 81 children aged 0.4 to 25 months from hospital wards and neonatal follow-up clinics. Interventions: Study 1: heads measured with plastic tape using both the WHO tight and UK loose technique. Study 2: heads measured using WHO research technique and a metal measuring tape and compared with routinely acquired measurements. Main outcome measures: Mean difference in head z-scores using WHO standard between the two methods. Results: The tight technique resulted in a mean (95% CI) z-score difference of 0.41 (0.27 to 0.54, p<0.001) in study 1 and 0.44 (0.36 to 0.53, p<0.001) in study 2. However, the mean WHO measurements in the healthy infants still produced a mean z-score that was two-third of a centile space (0.54 SD (0.28 to 0.79) p<0.001) above the 50th centile. Conclusion: The WHO measurement techniques produced significantly lower measures of head size, but average healthy Scottish children still had larger heads than the WHO standard using this method

    Varying the Divergence of Multiple Parallel Laser Beams

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    A provision for controlled variation of the divergence of a laser beam or of multiple parallel laser beams has been incorporated into the design of a conceptual free-space optical-communication station from which the transmitted laser beam(s) would be launched via a telescope. The original purpose to be served by this provision was to enable optimization, under various atmospheric optical conditions, of the divergence of a laser beam or beams transmitted from a ground station to a spacecraft

    Asteroid Diameters and Albedos from NEOWISE Reactivation Mission Years 4 and 5

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    The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has been conducting a two-band thermal infrared survey to detect and characterize asteroids and comets since its reactivation in 2013 December. Using the observations collected during the fourth and fifth years of the survey, our automated pipeline detected candidate moving objects that were verified and reported to the Minor Planet Center. Using these detections, we perform thermal modeling of each object from the near-Earth object (NEO) and Main Belt asteroid (MBA) populations to constrain their sizes. We present thermal model fits of asteroid diameters for 189 NEOs and 5831 MBAs detected during the fourth year of the survey, and 185 NEOs and 5776 MBAs from the fifth year. To date, the NEOWISE Reactivation survey has provided thermal model characterization for 957 unique NEOs. Including all phases of the original Wide-field Infrared Survey Explorer survey brings the total to 1473 unique NEOs that have been characterized between 2010 and the present

    Adverse childhood experiences and deleterious outcomes in adulthood: A consideration of the simultaneous role of genetic and environmental influences in two independent samples from the United States

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    Background Adverse childhood experiences (ACEs) are a potent risk factor. Despite these findings, studies have also recognized the importance of considering additional sources of genetic and environmental influence that cluster within families. Objective To properly control for latent sources of genetic and within-family environmental influences and isolate the association between ACEs and the following outcomes in adulthood: physical health, depressive symptoms, educational attainment, income attainment, alcohol problems, and antisocial behavior. Participants and Setting Two independent samples of twins and siblings from the United States: the Midlife Development in the United States (MIDUS) study (N = 862) and the National Longitudinal Study of Adolescent to Adult Health (Add Health; N = 3112). Methods Sibling comparison models, which control for latent sources of genetic and within-family environmental influences, were estimated to examine whether differential exposure to ACEs was associated with the examined outcomes. Results Families that experienced more adversity also experienced more deleterious outcomes. However, siblings that experienced more adversity were no more likely to experience deleterious outcomes than their co-siblings. However, greater exposure to ACEs was associated with increases in depressive symptoms (Add Health). Additional models revealed that the similarity between siblings from the same family stemmed from latent sources of within-family environmental influences not captured by traditional ACEs measures. Conclusions Considering genetic influences and additional latent sources of within-family influences is crucial in isolating the effects of ACEs. Currently employed ACEs measures may not adequately capture the full range of impactful sources of family-level environmental influence

    A SYSTEMATIC REVIEW OF METHODOLOGIES USED TO ASSESS “UNANTICIPATED” CUTTING MECHANICS

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    Biomechanical analysis of cutting mechanics is a popular approach to assessing risk factors for injuries such as anterior cruciate ligament ruptures. The purpose of this study was to systematically review the methodological approaches to assessing unanticipated cutting mechanics and provide a review of such approaches. A total of 93 articles where identified that had assessed unanticipated cutting. The most common methodological design was a 45° cutting task following a run-up where the direction of the cut was determined by a light-based stimulus. External light stimuli create a worst-case scenario by providing information about the task at the last moment meaning opportunity for preparatory mechanics is limited. However, light stimuli do not allow for perception-action to take place and may therefore not truly reflect an athlete’s cutting mechanics

    Star formation in the merging Galaxy NGC3256

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    The central 5 kpc of the ultra-luminous merging galaxy NGC 3256 was mapped at J, H, K, L, and 10 micrometer, and a 2 micrometer spectra of the nuclear region was obtained. This data was used to identify and characterize the super starburst which has apparently been triggered and fuelled by the merger of two gas rich galaxies. It is also shown that the old stellar population has relaxed into a single spheroidal system, and that a supernova driven wind might eventually drive any remaining gas from the system to leave a relic which will be indistinguishable from an elliptical galaxy

    NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos

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    The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 um and 4.6 um of solar system objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner solar system, and thus the sizes of these objects. In this paper we present thermal model fits of asteroid diameters for 170 NEOs and 6110 MBAs detected during the third year of the survey, as well as the associated optical geometric albedos. We compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1-sigma) of previously measured values. Diameters for the MBAs are within 17% (1-sigma). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.Comment: Accepted for publication in A

    Evidence for a Molecular Cloud Origin for Gamma-Ray Bursts: Implications for the Nature of Star Formation in the Universe

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    It appears that the majority of rapidly-, well-localized gamma-ray bursts with undetected, or dark, optical afterglows, or `dark bursts' for short, occur in clouds of size R > 10L_{49}^{1/2} pc and mass M > 3x10^5L_{49} M_{sun}, where L is the isotropic-equivalent peak luminosity of the optical flash. We show that clouds of this size and mass cannot be modeled as a gas that is bound by pressure equilibrium with a warm or hot phase of the interstellar medium (i.e., a diffuse cloud): Such a cloud would be unstable to gravitational collapse, resulting in the collapse and fragmentation of the cloud until a burst of star formation re-establishes pressure equilibrium within the fragments, and the fragments are bound by self-gravity (i.e., a molecular cloud). Consequently, dark bursts probably occur in molecular clouds, in which case dark bursts are probably a byproduct of this burst of star formation if the molecular cloud formed recently, and/or the result of lingering or latter generation star formation if the molecular cloud formed some time ago. We then show that if bursts occur in Galactic-like molecular clouds, the column densities of which might be universal, the number of dark bursts can be comparable to the number of bursts with detected optical afterglows: This is what is observed, which suggests that the bursts with detected optical afterglows might also occur in molecular clouds. We confirm this by modeling and constraining the distribution of column densities, measured from absorption of the X-ray afterglow, of the bursts with detected optical afterglows: We find that this distribution is consistent with the expectation for bursts that occur in molecular clouds, and is not consistent with the expectation for bursts that occur in diffuse clouds. More...Comment: Accepted to The Astrophysical Journal, 22 pages, 6 figures, LaTe
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