148 research outputs found
Incorporating Precipitation-Induced Variation in Annual Forage Production Into Economic Analyses of Range Improvement Practices.
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Avaliação da integridade e da retenção de metais pesados em materiais estabilizados por solidificação
The type II-plateau supernova 2017eaw in NGC 6946 and its red supergiant progenitor
We present extensive optical photometric and spectroscopic observations, from 4 to 482 days after explosion, of the Type II-plateau (II-P) supernova (SN) 2017eaw in NGC 6946. SN 2017eaw is a normal SN II-P intermediate in properties between, for example, SN 1999em and SN 2012aw and the more luminous SN 2004et, also in NGC 6946. We have determined that the extinction to SN 2017eaw is primarily due to the Galactic foreground and that the SN site metallicity is likely subsolar. We have also independently confirmed a tip-of-the-red-giant-branch (TRGB) distance to NGC 6946 of 7.73 ± 0.78 Mpc. The distances to the SN that we have also estimated via both the standardized candle method and expanding photosphere method corroborate the TRGB distance. We confirm the SN progenitor identity in pre-explosion archival Hubble Space Telescope (HST) and Spitzer Space Telescope images, via imaging of the SN through our HST Target of Opportunity program. Detailed modeling of the progenitor's spectral energy distribution indicates that the star was a dusty, luminous red supergiant consistent with an initial mass of ~15 M ⊙
Cultural constructions of happiness: theory and emprical evidence
In a review of recent cross-cultural evidence on happiness and well-being, the authors identified substantial cultural variations in (1) cultural meanings of happiness, (2) motivations underlying happiness, and (3) predictors of happiness. Specifically, in North American cultural contexts, happiness tends to be defined in terms of personal achievement. Individuals engaging in these cultures are motivated to maximize the experience of positive affect. Moreover, happiness is best predicted by self-esteem. In contrast, in East Asian cultural contexts, happiness tends to be defined in terms of interpersonal connectedness. Individuals engaging in these cultures are motivated to maintain a balance between positive and negative affects. Moreover, happiness is best predicted by perceived embeddedness of the self in a social relationship. Directions for future research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43061/1/10902_2004_Article_5278785.pd
Efeito da adição de fontes de matéria orgânica como amenizantes do efeito tóxico de B, Zn, Cu, Mn e Pb no cultivo de Brassica juncea
Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment
The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate and low-photochemical activity), to investigate indoor pollution, and to study dispersion of pollution as affected by frequent temperature inversions. A number of the research goals were motivated by questions raised by residents of Fairbanks, Alaska, where the study was held. This paper describes the measurement strategies and the conditions encountered during the January and February 2022 field experiment, and reports early examples of how the measurements addressed research goals, particularly those of interest to the residents. Outdoor air measurements showed high concentrations of particulate matter and pollutant gases including volatile organic carbon species. During pollution events, low winds and extremely stable atmospheric conditions trapped pollution below 73 m, an extremely shallow vertical scale. Tethered-balloon-based measurements intercepted plumes aloft, which were associated with power plant point sources through transport modeling. Because cold climate residents spend much of their time indoors, the study included an indoor air quality component, where measurements were made inside and outside a house to study infiltration and indoor sources. In the absence of indoor activities such as cooking and/or heating with a pellet stove, indoor particulate matter concentrations were lower than outdoors; however, cooking and pellet stove burns often caused higher indoor particulate matter concentrations than outdoors. The mass-normalized particulate matter oxidative potential, a health-relevant property measured here by the reactivity with dithiothreiol, of indoor particles varied by source, with cooking particles having less oxidative potential per mass than pellet stove particles
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