202 research outputs found
Applicability and Utility of the Astromaterials X-Ray Computed Tomography Laboratory at Johnson Space Center
The Astromaterials Acquisition and Curation Office at NASAs Johnson Space Center is responsible for curating all of NASAs astromaterial sample collections (i.e. Apollo samples, Luna Samples, Antarctic Meteorites, Cosmic Dust Particles, Microparticle Impact Collection, Genesis solar wind atoms, Stardust comet Wild-2 particles, Stardust interstellar particles, and Hayabusa asteroid Itokawa particles) [1-3]. To assist in sample curation and distribution, JSC Curation has recently installed an X-ray computed tomography (XCT) scanner to visualize and characterize samples in 3D. [3] describes the instrumental set-up and the utility of XCT to astromaterials curation. Here we describe some of the current and future projects and illustrate the usefulness of XCT in studying astromaterials
Air quality resolution for health impact assessment: influence of regional characteristics
We evaluate how regional characteristics of population and background pollution might impact the selection of optimal air quality model resolution when calculating the human health impacts of changes to air quality. Using an approach consistent with air quality policy evaluation, we use a regional chemical transport model (CAMx) and a health benefit mapping program (BenMAP) to calculate the human health impacts associated with changes in ozone and fine particulate matter resulting from an emission reduction scenario. We evaluate this same scenario at 36, 12 and 4 km resolution for nine regions in the eastern US representing varied characteristics. We find that the human health benefits associated with changes in ozone concentrations are sensitive to resolution. This finding is especially strong in urban areas where we estimate that benefits calculated using coarse resolution results are on average two times greater than benefits calculated using finer scale results. In three urban areas we analyzed, results calculated using 36 km resolution modeling fell outside the uncertainty range of results calculated using finer scale modeling. In rural areas the influence of resolution is less pronounced with only an 8% increase in the estimated health impacts when using 36 km resolution over finer scales. In contrast, health benefits associated with changes in PM[subscript 2.5] concentrations were not sensitive to resolution and did not follow a pattern based on any regional characteristics evaluated. The largest difference between the health impacts estimated using 36 km modeling results and either 12 or 4 km results was at most ±10% in any region. Several regions showed increases in estimated benefits as resolution increased (opposite the impact seen with ozone modeling), while some regions showed decreases in estimated benefits as resolution increased. In both cases, the dominant contribution was from secondary PM. Additionally, we found that the health impacts calculated using several individual concentrationâresponse functions varied by a larger amount than the impacts calculated using results modeled at different resolutions. Given that changes in PM[subscript 2.5] dominate the human health impacts, and given the uncertainty associated with human health response to changes in air pollution, we conclude that, when estimating the human health benefits associated with decreases in ozone and PM[subscript 2.5] together, the benefits calculated at 36 km resolution agree, within errors, with the benefits calculated using fine (12 km or finer) resolution modeling when using the current methodology for assessing policy decisions.United States. Environmental Protection Agency. Science to Achieve Results Program (Grant R834279)MIT Energy Initiative (Total Energy Fellowship)United States. Dept. of Energy. Office of Science (Grant DE-FG02-94ER61937)Massachusetts Institute of Technology. Joint Program on the Science & Policy of Global Chang
âOnce youâve been there, youâre always recoveringâ: exploring experiences, outcomes, and benefits of substance misuse recovery
Purpose â Recovery is a central component of UK substance misuse policy, however, relatively little is known about the views and meanings of recovery by those experiencing it. The purpose of this paper is to explore these factors, and understand how service user experiences align to current understandings of ârecovery capitalâ. Design/methodology/approach â This paper draws on qualitative interviews with 32 individuals from six UK recovery communities, including those commissioned by a statutory service (n=8) and a peer-led recovery community (n=24). Findings â Meanings of recovery differed between people in abstinence-based communities and those not; however, all had consistent views on their own recovery outcomes and the benefits they believed recovery brought. All viewed recovery as a process; a continuous journey with no end-point. Internal motivation, peer support, social networks and daily structure were integral to supporting individuals achieve and maintain recovery. Key benefits of recovery reflected recovery capital and included positive relationships, sense of belonging, increased self-worth and confidence, employment and education. Research limitations/implications â This research shows that recovery experiences and outcomes are not centred entirely on the individual but are wider, more holistic. Maintaining recovery involves being connected to themselves and to the wider environment: family, friends, peers and society. Although the recovery capital model has many elements that were discussed by the participants of this research, the discourse they used does not align with the model. To validly measure and quantify recovery outcomes, individuals need to identify with the measures themselves. Practical implications â From policy and commissioning perspectives, these findings suggest benefits of recovery that were viewed by participants as indicators of success: demonstrate elements which support recovery; and highlight key social value outcomes which people attribute to recovery. Social implications â These âsofterâ, qualitative benefits should be considered by policy-makers, commissioners, statutory and non-statutory services in order to evidence outcomes. However, it should also be recognised that a temporally static approach to assessing recovery may be in contradiction to the meaning and perspectives held by those in recovery communities who conceptualise it as a long term and ongoing process. Originality/value â This paper adds to understandings of experiences and meanings of recovery, with a particular focus on the measurement of outcomes and their meanings, and the role of abstention and continued drug use within the recovery process. © 2016, Emerald Group Publishing Limited
Evaluation of Four Recovery Communities across England: Interim report for the Give it Up project
The Comic Relief: Give it Up Fund is a programme that aims to develop and build abstinence based recovery communities and learn more about their value. The Give it Up Fund supports the development of recovery communities in four geographical locations in England. It is
expected that the recovery communities will be sustainable and continue to operate after the two years of funding is complete. The aim of this research is to evaluate the operational processes of the pilot programmes and better understand how they might contribute to ambitions of improved and sustained recovery.
Abstinence-based recovery communities aim to ensure that people with addictions are supported to meet their personal, social and economic needs in order to enable long-term recovery and reintegration back into society. Abstinence-based recovery complements the UK Drug Strategy (2010) objective of supporting people to live abstinence-based, âdrug-freeâ lives.
The large grants programme element of the Give it Up Fund is supporting the development of recovery communities in Durham, Birmingham, Gloucester and London by creating partnerships offering collaborative working with approaches that aim to sustain recovery.
This work explores how each of the projects contribute to recovery outcomes over time, and aims to embed processes to ensure that projects are able to measure and evidence their outcomes once the commissioned evaluation has finished
The Impact of Laser Control on The Porosity And Microstructure of Selective Laser Melted Nickel Superalloy 718
Additively manufacturing high performance metals by laser processing represents an exciting opportunity to exploit localized properties by varying input parameters throughout the process. This work explores the solidification and microstructural properties of selectively laser melted (SLM) Inconel 718 (IN718) using unique processing parameters. By employing traditional pulsed laser physics techniques, samples were manufactured with a continuous wave laser to study a potential ubiquitous approach. While the overall power density was controlled, the power, speed, and hatch spacing were varied. The porosity and grain sizes of the samples were characterized by optical and scanning electron microscopes. The influence of processing parameters showed physical differences in the final samples. Sample degradation was observed in higher power processes with porosity up 10%, likely due to increased temperatures and more intense thermal gradients
Influence of Nano-Sized SiC on the Laser Powder Bed Fusion of Molybdenum
Consolidation of pure molybdenum through laser powder bed fusion and other additive manufacturing techniques is complicated by a high melting temperature, thermal conductivity and ductile-to-brittle transition temperature. Nano-sized SiC particles (0.1 wt%) were homogeneously mixed with molybdenum powder and the printing characteristics, chemical composition, microstructure, mechanical properties were compared to pure molybdenum for scan speeds of 100, 200, 400, and 800 mm/s. The addition of SiC improved the optically determined density and flexural strength at 400 mm/s by 92% and 80%, respectively. The oxygen content was reduced by an average of 52% over the four scan speeds analyzed. Two mechanisms of oxygen reduction were identified as responsible for the improvements: oxidation of free carbon and the creation of secondary phase nanoparticles. This study illustrates the promising influence of nanoparticle additions to refractory metals in laser powder bed fusion
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