33 research outputs found
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Dynamic Load and Storage Integration
Modern technology combined with the desire to minimize the size and weight of a ship’s power system are leading to renewed interest in more electric or all electric ships. An important characteristic of the emerging ship power system is an increasing level of load variability, with some future pulsed loads requiring peak power in excess of the available steady– state power. This inevitably leads to the need for some additional energy storage beyond that inherent in the fuel. With the current and evolving technology, it appears that storage will be in the form of batteries, rotating machines, and capacitors. All of these are in use on ships today and all have enjoyed significant technological improvements over the last decade. Moreover all are expected to be further enhanced by today’s materials research. A key benefit of storage is that, when it can be justified for a given load, it can have additional beneficial uses such as ride-through capability to restart a gas turbine if there is an unanticipated power loss; alternatively, storage can be used to stabilize the power grid when switching large loads. Knowing when to stage gas turbine utilization versus energy storage is a key subject in this paper. The clear need for storage has raised the opportunity to design a comprehensive storage system, sometimes called an energy magazine, that can combine intermittent generation as well as any or all of the other storage technologies to provide a smaller, lighter and better performing system than would individual storage solutions for each potential application.Center for Electromechanic
Plant damage in urban agroecosystems varies with local and landscape factors
Biotic and abiotic factors at local to landscape scales influence insect pest and disease dynamics in agricultural systems. However, relative to studies focused on the importance of these drivers of crop plant damage in rural agricultural systems, few studies investigate plant damage from herbivore insects and plant diseases in urban agroecosystems, and consequently, most urban farmers lack knowledge on crop protection tactics. Here we use three common crop species within urban agroecosystems (community gardens) distributed across an urban landscape as a model system to ask how local, landscape, and microclimate factors relate to herbivore and disease plant damage. We hypothesized that plant damage would be lower in gardens with greater local vegetation complexity, landscape‐scale complexity, and less variable temperatures, but that the importance of factors is species‐ and damage‐specific. By measuring Brassica, cucurbit, and tomato insect pest and disease damage across the growing season, we confirmed that the importance of factors varies with crop species and by damage type. Both local complexity factors (e.g., number of trees and shrubs) and landscape complexity (percent natural cover in the landscape) relate to lower incidence of herbivore and disease damage on some crops, supporting our prediction that habitat heterogeneity at both local and landscape scales lowers plant damage. Greater temperature variability related to higher disease damage on tomatoes linking microclimate factors to disease prevalence. Yet, local complexity factors also related to higher incidence of plant damage for other crop species, indicating variable species‐level impacts of local management factors on plant damage. By measuring the abundance of fungus‐feeding lady beetles (Psyllobora) on cucurbits, we confirmed a strong association between natural enemies and powdery mildew. We provide a case study on how changes in local to landscape‐scale factors relate to plant damage in urban agroecosystems and suggest how urban farmers and gardeners can apply this ecological knowledge to improve sustainable urban food production.TU Berlin, Open-Access-Mittel - 202
Information sharing, scheduling, and awareness in community gardening collaboration
Community gardens are places where people, as a collaborative group, grow food for themselves and for others. There is a lack of studies in HCI regarding collaboration in community gardens and considering technologies to support such collaborations. This paper reports on a detailed study of collaboration in community gardens in Greater Vancouver, Canada. The goal of our study is to uncover the unique nature of such collaborative acts. As one might expect, we found considerable differences between community gardening collaboration and workplace collaboration. The contribution is the articulation of key considerations for designing technologies for community gardening collaboration. These include design considerations like volunteerism, competences and inclusion, synchronicity, and telepresence as unique aspects of community collaboration in community garden. We also articulate the complexities of community gardening collaboration, which raise ibues like control, shared language, and collective ownership that exist more as conditions within which to design than "problems" to solve through technologies
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ORNL/IAT ARMATURE DIAGNOSTICS DEMONSTRATION TEST REPORT: PART TWO: BENCH DEMONSTRATION
The purpose of the present effort was to demonstrate 'on the fly' temperature measurement of railgun armatures on a bench top railgun. The effort builds on the previous test that utilized a portable unit with armature speeds ranging from 50 to 90 m/s. The tests described here involved higher speeds, ranging from 300 to 500 m/s. The method to accomplish the measurement involves pulsed laser illumination of a phosphor-coated armature. The duration of the ensuing fluorescence indicates temperature. The measured temperatures, obtained both inside the muzzle and outside in free flight, ranged between 80 to 110 C. The required pulsed fluorescence was made possible by successfully sensing the position of the armature while traveling within the laser illumination and fluorescence sensing fields-of-view. A high-speed camera also captured images of the moving armatures after exiting the railgun. These images sometimes included the fluorescing region of the phosphor coating
Increased Membrane Cholesterol in Lymphocytes Diverts T-Cells toward an Inflammatory Response
Cell signaling for T-cell growth, differentiation, and apoptosis is initiated in the cholesterol-rich microdomains of the plasma membrane known as lipid rafts. Herein, we investigated whether enrichment of membrane cholesterol in lipid rafts affects antigen-specific CD4 T-helper cell functions. Enrichment of membrane cholesterol by 40–50% following squalene administration in mice was paralleled by an increased number of resting CD4 T helper cells in periphery. We also observed sensitization of the Th1 differentiation machinery through co-localization of IL-2Rα, IL-4Rα, and IL-12Rβ2 subunits with GM1 positive lipid rafts, and increased STAT-4 and STAT-5 phosphorylation following membrane cholesterol enrichment. Antigen stimulation or CD3/CD28 polyclonal stimulation of membrane cholesterol-enriched, resting CD4 T-cells followed a path of Th1 differentiation, which was more vigorous in the presence of increased IL-12 secretion by APCs enriched in membrane cholesterol. Enrichment of membrane cholesterol in antigen-specific, autoimmune Th1 cells fostered their organ-specific reactivity, as confirmed in an autoimmune mouse model for diabetes. However, membrane cholesterol enrichment in CD4+
Foxp3+ T-reg cells did not alter their suppressogenic function. These findings revealed a differential regulatory effect of membrane cholesterol on the function of CD4 T-cell subsets. This first suggests that membrane cholesterol could be a new therapeutic target to modulate the immune functions, and second that increased membrane cholesterol in various physiopathological conditions may bias the immune system toward an inflammatory Th1 type response
Final purification and concentration of americium/curium separated from high-level reprocessing waste
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What difference does income make for Community Supported Agriculture (CSA) members in California? Comparing lower-income and higher-income households
In the U.S. there has been considerable interest in connecting low-income households to alternative food networks like Community Supported Agriculture (CSA). To learn more about this possibility we conducted a statewide survey of CSA members in California. A total of 1149 members from 41 CSAs responded. Here we answer the research question: How do CSA members’ (1) socioeconomic and demographic backgrounds, (2) household conditions potentially interfering with membership, and (3) CSA membership experiences vary between lower-income households (LIHHs) and higher-income households (HIHHs)? We divided members into LIHHs (making under 50,000 annually). We present comparisons of LIHHs’ and HIHHs’ (1) employment, race/ethnicity, household composition and education, use of food support, and enjoyment of food-related activities; (2) conditions interfering with membership and major life events; and (3) sources of information influencing decision to join, reasons for joining, ratings of importance of and satisfaction with various CSA attributes, gaps between importance of and satisfaction with various CSA attributes, valuing of the share and willingness to pay more, and impacts of membership. We find that LIHHs are committed CSA members, often more so than HIHHs, and that CSA members in California are disproportionately white, but that racial disproportionality decreases as incomes increase. We conclude by considering: (1) the economic risks that LIHHs face in CSA membership, (2) the intersection of economic risks with race/ethnicity and cultural coding in CSA; and (3) the possibilities of increasing participation of LIHH in CSA
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What difference does income make for Community Supported Agriculture (CSA) members in California? Comparing lower-income and higher-income households
In the U.S. there has been considerable interest in connecting low-income households to alternative food networks like Community Supported Agriculture (CSA). To learn more about this possibility we conducted a statewide survey of CSA members in California. A total of 1149 members from 41 CSAs responded. Here we answer the research question: How do CSA members’ (1) socioeconomic and demographic backgrounds, (2) household conditions potentially interfering with membership, and (3) CSA membership experiences vary between lower-income households (LIHHs) and higher-income households (HIHHs)? We divided members into LIHHs (making under 50,000 annually). We present comparisons of LIHHs’ and HIHHs’ (1) employment, race/ethnicity, household composition and education, use of food support, and enjoyment of food-related activities; (2) conditions interfering with membership and major life events; and (3) sources of information influencing decision to join, reasons for joining, ratings of importance of and satisfaction with various CSA attributes, gaps between importance of and satisfaction with various CSA attributes, valuing of the share and willingness to pay more, and impacts of membership. We find that LIHHs are committed CSA members, often more so than HIHHs, and that CSA members in California are disproportionately white, but that racial disproportionality decreases as incomes increase. We conclude by considering: (1) the economic risks that LIHHs face in CSA membership, (2) the intersection of economic risks with race/ethnicity and cultural coding in CSA; and (3) the possibilities of increasing participation of LIHH in CSA