Technological systems and momentum change: American electric utilities, restructuring, and distributed generation

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Wind turbines and invisible technology: unarticulated reasons for local opposition to wind energy

Local opposition to wind turbines stems from concerns about environmental and economic damage, as well as conflicts between rural and urban residents. This essay goes beyond these considerations to explore the often-unarticulated explanations for animosity toward this energy technology. Originally, it posits that opposition to visually obvious turbines arises from the successful history of an electric utility system that made its product largely invisible in its manufacture and physical manifestation. The existence of conspicuous turbines, however, reminds observers that power generation requires difficult choices in a technology-based society. The system’s previous achievement in hiding infrastructural elements, in other words, sometimes works ironically to spur objections to wind turbines. Receiving little historical study, the concealed features of a system’s infrastructure often influence assessments of technologies. By revealing the previously invisible, this essay, which draws on research in history, landscape architecture, geography, and psychology, therefore provides insights for social scientists and policymakers

Assessing U.S. energy policy

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Reviews and syntheses: Spatial and temporal patterns in seagrass metabolic fluxes

Seagrass meadow metabolism has been measured for decades to gain insight into ecosystem energy, biomass production, food web dynamics, and, more recently, to inform its potential in ameliorating ocean acidification (OA). This extensive body of literature can be used to infer trends and drivers of seagrass meadow metabolism. Here, we synthesize the results from 56 studies reporting in situ rates of seagrass gross primary productivity, respiration, and/or net community productivity to highlight spatial and temporal variability in oxygen (O2) fluxes. We illustrate that daytime net community production (NCP) is positive overall and similar across seasons and geographies. Full-day NCP rates, which illustrate the potential cumulative effect of seagrass beds on seawater biogeochemistry integrated over day and night, were also positive overall but were higher in summer months in both tropical and temperate ecosystems. Although our analyses suggest seagrass meadows are generally autotrophic, the effects on seawater oxygen are relatively small in magnitude. We also find positive correlations between gross primary production and temperature, although this effect may vary between temperate and tropical geographies and may change under future climate scenarios if seagrasses approach thermal tolerance thresholds. In addition, we illustrate that periods when full-day NCP is highest could be associated with lower nighttime O2 and increased diurnal variability in seawater O2. These results can serve as first-order estimates of when and where OA amelioration by seagrasses may be likely. However, improved understanding of variations in NCPdic:NCPO2 ratios and increased work directly measuring metabolically driven alterations in seawater pH will further inform the potential for seagrass meadows to serve in this context

Shovels and Swords: How realistic and fantastical themes affect children's word learning

Cataloged from PDF version of article.Research has shown that storybooks and play sessions help preschool children learn vocabulary, thereby benefiting their language and school readiness skills. But the kind of content that leads to optimal vocabulary learning – realistic or fantastical – remains largely unexplored. We investigate this issue as part of a large-scale study of vocabulary learning in low-income classrooms. Preschoolers (N = 154) learned 20 new words over the course of a two-week intervention. These words were taught using either realistic (e.g., farms) or fantastical (e.g., dragons) storybooks and toys. Children learned the new words in both conditions, and their comprehension knowledge did not differ across conditions. However, children who engaged in stories and play with a fantastical theme showed significantly greater gains in their production knowledge. Reasons for and implications of this result are discussed

Makerspaces in Libraries at U.S. Public Colleges and Universities: A Census

Makerspaces continue to grow in popularity in library ecosystems, yet no one has done a census on important data points, such as total active makerspaces, planned makerspaces, and types of makerspaces in public colleges and universities in the United States. The objective of this report is to gather baseline data on makerspaces, the majority of which are in academic libraries. Using an audit of websites, the researchers conducted a census of makerspaces at colleges and universities, collecting such data as makerspace status, location, and departmental affiliation. The researchers identified 284 active makerspaces and 35 planned makerspaces across 214 institutions; of these, 110 were affiliated with their institution’s library. This census offers a helpful baseline, but more data collection will provide a fuller representation of makerspaces in the United States

New measurement on photon yields from air and the application to the energy estimation of primary cosmic rays

The air fluorescence technique is used to detect ultra-high energy cosmic rays (UHECR), and to estimate their energy. Of fundamental importance is the photon yield due to excitation by electrons, in air of various densities and temperatures. After our previous report, the experiment has been continued using a Sr90 $\beta$ source to study the pressure dependence of photon yields for radiation in nitrogen and dry air. The photon yields in 15 wave bands between 300 nm and 430 nm have been determined. The total photon yield between 300 nm and 406 nm (used in most experiments) in air excited by a 0.85 MeV electron is 3.81+-0.13 (+-13 % systematics) photons per meter at 1013 hPa and 20 $^{\circ}$C. The air density and temperature dependencies of 15 wave bands are given for application to UHECR observations.Comment: 23 pages, 8 figures, LaTeX with elsart.cls, accepted by Astroparticle Physic

Modeling Operating Speed and Deceleration on Two-Lane Rural Roads with Global Positioning System Data

[EN] In the road design process, speed variation along the road segment is an important issue to consider in adapting road geometry to drivers' expectations. To achieve this objective, speed criteria are used to evaluate road consistency. Being able to estimate the operating speed in the design phase can lead to safer road alignment. With this objective, several researchers have developed operating speed models. Most of these models are based on collected spot speed data. They assume constant speed on curves and, therefore, deceleration that occurs entirely on the approach tangent. According to these assumptions, spot speed data are collected at the center of the horizontal curve and at the midpoint of the preceding tangent to obtain operating speed models. This paper presents a new methodology based on the use of Global Positioning System devices that allow continuous collecting and processing of speed data. With this new methodology, not only can new and more accurate operating speed models he developed, but cited hypotheses can also be checked. Observed speed continuous profiles allow studies that previously could not be done, especially as related to deceleration and speed variations. This study calibrated new speed models, including three for horizontal curves with a radius curve and the curvature change rate of a single curve as explanatory variables, and one for tangents that incorporates the curve speed model. Tangent-curve speed variations are evaluated, with comparison of Delta(85)V and Delta V(85), analysis of the deceleration length occurring on a curve, and development of two deceleration models.The authors thank the Center for Studies and Experimentation of Public Works of the Spanish Ministry of Public Works, which partially subsidized the research. The authors also thank the Infrastructure and Transportation Department, General Directorate of Public Works, Valencian Government, Spain; the Valencian Provincial Council; and the Ministry of the Interior, General Directorate of Traffic, Spain, for their cooperation in field data gathering.Pérez Zuriaga, AM.; García García, A.; Camacho-Torregrosa, FJ.; D'attoma, P. (2010). Modeling Operating Speed and Deceleration on Two-Lane Rural Roads with Global Positioning System Data. Transportation Research Record. 2171:11-20. doi:10.3141/2171-02S1120217