1,568 research outputs found

    The radiation balance of the earth-atmosphere system from Nimbus 3 radiation measurements

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    The radiation balance of the earth-atmosphere system and its components was computed from global measurements of radiation reflected and emitted from the earth to space. These measurements were made from the meteorological satellite Nimbus 3 during the periods from April 16 to August 15, 1969; October 3 to 17, 1969; and January 21 to February 3, 1970. Primarily the method of evaluation, its inherent assumptions, and possible error sources were discussed. Results are presented by various methods: (1) global, hemispherical, and zonal averages obtained from measurements in all semimonthly periods and (2) global maps of the absorbed solar radiation, the albedo, the outgoing longwave radiation, and the radiation balance obtained from measurements during semimonthly periods in each season (May 1 to 15, July 16 to 31, and October 3 to 17, 1969, and January 21 to February 3, 1970). Annual global averages of the albedo and of the outgoing longwave radiation were determined. These values balance to within 1 percent the annual global energy input by solar radiation that was computed for a solar constant

    How accurate did GCMs compute the insolation at TOA for AMIP-2?

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    Monthly averages of solar radiation reaching the Top of the Atmosphere (TOA) as simulated by 20 General Circulation Models (GCMs) during the period 1985–1988 are compared. They were part of submissions to AMIP-2 (Atmospheric Model Intercomparison Project). Monthly averages of ISCCP-FD (International Satellite Cloud Climatology Project – Flux Data) are considered as reference. Considerable discrepancies are found: Most models reproduce the prescribed Total Solar Irradiance (TSI) value within ±0.7 Wm−2. Monthly zonal averages disagree between ±2 to ±7 Wm−2, depending on latitude and season. The largest model diversity occurs near polar regions. Some models display a zonally symmetric insolation, while others and ISCCP show longitudinal deviations of the order of ±1 Wm−2. With such differences in meridional gradients impacts in multi-annual simulations cannot be excluded. Sensitivity studies are recommended

    The Isolated Orbital Floor Fracture from a Transconjunctival or Subciliary Perspective-A Standardized Anthropometric Evaluation

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    Background: The influence of orbital fractures and their repair on the rate of deformities of the lower eyelid is an ongoing source of discussion in the literature. Most of the present studies include isolated blow-out as well as combined orbital fractures. Material and Methods: We present a retrospective evaluation of a series of 100 patients after isolated blow-out fracture repair using reference anthropometric data on standardized photographs. Analysis included eye fissure width and height, lid sulcus height, upper lid height, upper and lower iris coverage, position of cornea to palpebra inferior, canthal tilt, scleral show, ectropion and entropion. It was clearly distinguished between operated and contralateral eyelid, whether a transconjunctival or a subciliary approach was performed and amount of fracture. Our main interests were changes of the aforementioned parameters with regards to eyelid deformities. Results: Surgery per se did not significantly influence eyelid deformities. However, the surgical approach selected significantly affected eye fissure index, lower iris coverage and rate of scleral show, indicating retraction of the lower eyelid. Conclusions: The standardized measurements described here are accurate and objective to evaluate postoperative results. The subciliary approach included the highest risk of lower lid retraction as compared to transconjunctival approaches

    Quantum Monte Carlo calculations of H2_2 dissociation on Si(001)

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    We present quantum Monte Carlo calculations for various reaction pathways of H2_2 with Si(001), using large model clusters of the surface. We obtain reaction energies and energy barriers noticeably higher than those from approximate exchange-correlation functionals. In improvement over previous studies, our adsorption barriers closely agree with experimental data. For desorption, the calculations give barriers for conventional pathways in excess of the presently accepted experimental value, and pinpoint the role of coverage effects and desorption from steps.Comment: 4 pages, 1 figur

    Quality of Postoperative Pain Management after Midfacial Fracture Repair—An Outcome-oriented Study

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    Objectives There is a lack of literature regarding the procedure-specific quality of acute postoperative pain management after midfacial fracture repair. The purpose of the presented prospective clinical study was to evaluate postoperative pain management after surgical repair of midfacial fractures. Materials and methods Eighty-five adults were evaluated on the first postoperative day following midfacial repair using the questionnaire of the Quality Improvement in Postoperative Pain Management (QUIPS) project. The main outcome measures were patients’ characteristics and clinical- and patient-reported outcome parameters. Results Overall, pain on the first postoperative day was moderate. A significant correlation between process and outcome parameters could be shown. Duration of surgery above the calculated median was significantly associated with higher maximum pain intensity (p = 0.017). Patients requiring opioids in the recovery room presented significantly higher pain on activity (p = 0.029) and maximum pain (p = 0.035). Sleeping impairment (p = 0.001) and mood disturbance (p = 0.008) were significantly more prevalent in patients undergoing repair of a centrolateral midfacial fracture. Conclusions QUIPS is a simple and qualified tool to evaluate the procedure specific quality of acute postoperative pain management. Pain on the first postoperative day following midfacial fracture repair seems overall to be moderate. Nearly a third of the patients showed inadequate postoperative pain management. To prevent inadequate postoperative pain management, it is necessary to establish a continued procedure-specific outcome measurement

    Measuring degree-degree association in networks

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    The Pearson correlation coefficient is commonly used for quantifying the global level of degree-degree association in complex networks. Here, we use a probabilistic representation of the underlying network structure for assessing the applicability of different association measures to heavy-tailed degree distributions. Theoretical arguments together with our numerical study indicate that Pearson's coefficient often depends on the size of networks with equal association structure, impeding a systematic comparison of real-world networks. In contrast, Kendall-Gibbons' Ï„b\tau_{b} is a considerably more robust measure of the degree-degree association
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