937 research outputs found

    Stratospheric constituent distributions from balloon-based limb thermal emission measurements

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    This research task deals with an analysis of infrared thermal emission observations of the Earth's atmosphere for determination of trace constituent distributions. Infrared limb thermal emission spectra in the 700-2000 cm(exp -1) region were obtained with a liquid nitrogen cooled Michelson interferometer-spectrometer (SIRIS) on a balloon flight launched from Palestine, Texas, at nighttime on September 15-16, 1986. An important objective of this work is to obtain simultaneously measured vertical mixing ratio profiles of O3, H2O, N2O, NO2, N2O5, HNO3 and ClONO2 and compare with measurements made with a variety of techniques by other groups as well as with photochemical model calculations. A portion of the observed spectra obtained by SIRIS from the balloon flight on September 15-16, 1986, has been analyzed with a focus on calculation of the total nighttime odd nitrogen budget from the simultaneously measured profiles of important members of the NO(sub x) family. The measurements permit first direct determination of the nighttime total odd nitrogen concentrations NO(sub y) and the partitioning of the important elements of the NO(sub x) family

    Dispersion and lineshape of plasmon satellites in one, two and three dimensions

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    Using state-of-the-art many-body Green's function calculations based on the "GW plus cumulant" approach, we analyze the properties of plasmon satellites in the electron spectral function resulting from electron-plasmon interactions in one-, two- and three-dimensional systems. Specifically, we show how their dispersion relation, lineshape and linewidth are related to the properties of the constituent electrons and plasmons. To gain insight into the many-body processes giving rise to the formation of plasmon satellites, we connect the "GW plus cumulant" approach to a many-body wavefunction picture of electron-plasmon interactions and introduce the coupling-strength weighted electron-plasmon joint-density states as a powerful concept for understanding plasmon satellites.Comment: 6 papers, 2 figure

    Imaging Studies of photodamage and self-healing in disperse orange 11 dye-doped PMMA

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    We report on optical imaging studies of self-healing after laser-induced photodamage in disperse orange 11 dye doped into poly(methyl methacrylate) (PMMA) polymer. In particular, the high spatial-contrast image of the damage track made by a line focus pump laser allows the recovery rates to be measured as a function of burn dose using the relationship between transverse distance and pump intensity profile. The time evolution of the damaged population results in an intensity-independent time constant of {\tau} = 490\pm23 min, in agreement with independent measurements of the time evolution of amplified spontaneous emission. Also observed is a damage threshold above which the material does not fully recover.Comment: 5 pages, 8 figure

    Building on the Edge: A Dialogue Between the Past and the Present; the Re-excavation of History in our Modern Cities

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    The intent of this architectural thesis is to demonstrate that a new building intervention on the designated urban site will maintain the southern edge of the \u27modern\u27 twentieth century gridded city of Rome overlooking the \u27ancient\u27 city of the Forum. This edge, acting as a seam, will attempt to strengthen the relationship between these two urban conditions. The second half of this thesis will be to develop an articulated facade for this edge to create a modern building which responds not only to the buildings of the modern city, but also to the buildings of the ancient, or archaeological city of Rome

    Communications of the Lunar and Planetary Laboratory, volume 8, part 3

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    Infrared photography, mapping, and orbit calculation of natural satellites, comets, and planets in solar syste

    Effects of Acute Low-Intensity Cycling on Perceived Stress, Arousal, and Attention

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    Generally, acute bouts of aerobic exercise have been shown to enhance psychological measures of emotion, mood, and affect. Previous investigations suggest that perceived stress and arousal levels are especially influenced by exercise. Interestingly, very few studies have examined the influence of exercise on attention and whether changes in stress and arousal may augment adaptations in attentional orientation that are often required during exercise. Furthermore, very little is known about the timing of the effects of exercise on these psychological outcomes. PURPOSE: The primary purpose of this study was to examine the effects of low-intensity aerobic exercise on stress, arousal, and attention. A secondary aim was to evaluate the time-course effects of exercise on stress, arousal, and attention. METHODS: Twenty (Mage = 23.2 ± 3.1 years old) college-aged individuals were counterbalanced into low-intensity exercise (LI) and seated control (SC) conditions. During each condition, participants completed a 10-minute resting baseline period, 20 minutes of either sustained cycling or seated rest, and a 20-minute recovery period. Primary outcomes of stress, arousal, and attention were assessed at 10-minute intervals throughout each condition via a Visual Analog Scale for Stress (VAS-S), Felt Arousal Scale (FAS), and Attentional Focus Scale (AFS), respectively. RESULTS: For the VAS-S, a Time main effect was revealed, F(4,16) = 5.76, p = .005, suggesting general reductions in stress following both LI and SC conditions. A Time main effect was also found for the FAS, which was superseded by a Condition x Time interaction, F(4,16) = 3.08, p = .047, indicating a greater increase in arousal levels during the LI condition compared to the SC condition. Lastly, a Time main effect for the AFS was found, F(4,16) = 3.05, p = .049, indicating general shifts from internal to external focus during each condition. CONCLUSION: Taken together, the current results suggest that exercise at lower doses (i.e., low-intensity for 20 minutes) may have minimal influence on more complex psychological perceptions of stress and attention. These results may help us better understand the complicated interactions between common psychological measures used in exercise science research. Additionally, this study may aid in the development of appropriate exercise prescriptions for populations looking to specifically target stress, arousal, and attention
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