2,593 research outputs found

    Downward shortwave surface irradiance from 17 sites for the FIRE/SRB Wisconsin experiment

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    A field experiment was conducted in Wisconsin during Oct. to Nov. 1986 for purposes of both intensive cirrus cloud measurments and SRB algorithm validation activities. The cirrus cloud measurements were part of the FIRE. Tables are presented which show data from 17 sites in the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment/Surface Radiation Budget (FIRE/SRB) Wisconsin experiment region. A discussion of intercomparison results and calibration inconsistencies is also included

    The Caries Phenomenon: A Timeline from Witchcraft and Superstition to Opinions of the 1500s to Today's Science

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    This historical treatise follows the documented timeline of tooth decay into today's understanding, treatment, and teaching of caries biology. Caries has been attributed to many different causes for several millennia, however, only since the late 1900s has research revealed its complex multifactorial nature. European writers of the 1600s to 1700s held views that general health, mechanical injuries, trauma, and sudden temperature changes all caused caries—holding a common belief that decay was due to chemical agents, faulty saliva, and food particles. Until the early 1800s most writers believed that caries was due to inflammation from surrounding diseased alveolar bone. Today's science has demonstrated that caries is caused by indigenous oral microorganisms becoming a dynamic biofilm, that in the presence of fermentable sugars produce organic acids capable of dissolving inorganic enamel and dentin followed by the proteolytic destruction of collagen leaving soft infected dentin. As bacteria enter the pulp, infection follows

    Cryptic photosynthesis, Extrasolar planetary oxygen without a surface biological signature

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    On the Earth, photosynthetic organisms are responsible for the production of virtually all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge that developed about 450 Myr ago and has been proposed as a biosignature for life on extrasolar planets. However, in many regions of the Earth, and particularly where surface conditions are extreme, for example in hot and cold deserts, photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature to indicate life. The same is true of the assemblages of photosynthetic organisms at more than a few metres depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We link geomicrobiology with observational astronomy by calculating the disk-averaged spectra of cryptic habitats and identifying detectable features on an exoplanet dominated by such a biota. The hypothetical cryptic photosynthesis worlds discussed here are Earth-analogs that show detectable atmospheric biomarkers like our own planet, but do not exhibit a discernable biological surface feature in the disc-averaged spectrum.Comment: 23 pages, 2 figures, Astrobiology (TBP) - updated Table 1, typo in detectable O2 correcte

    Specific Etiologies Associated With the Multiple Organ Dysfunction Syndrome in Children: Part 2

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    To describe a number of conditions and therapies associated with multiple organ dysfunction syndrome (MODS) presented as part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development MODS Workshop (March 26–27, 2015). In addition, the relationship between burn injuries and MODS is also included although it was not discussed at the Workshop

    Progress Letter Report on Bending Fatigue Test System Development for Spent Nuclear Fuel Vibration Integrity Study (Out-of-cell fatigue testing development - Task 2.4)

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    Vibration integrity of high burn-up spent nuclear fuel in transportation remains to be a critical component of US nuclear waste management system. The structural evaluation of package for spent fuel transportation eventually will need to see if the content or spent fuel is in a subcritical condition. However, a system for testing and characterizing such spent fuel is still lacking mainly due to the complication involved with dealing radioactive specimens in a hot cell environment. Apparently, the current state-of-the-art in spent fuel research and development is quite far away from the delivery of reliable mechanical property data for the assessment of spent fuels in the transport package evaluation. Under the sponsorship of US NRC, ORNL has taken the challenge in developing a robust testing system for spent fuel in hot cell. An extensive literature survey was carried out and unique requirements of such testing system were identified. The U-frame setup has come to the top among various designs examined for reverse bending fatigue test of spent fuel rod. The U-frame has many features that deserve mentioned here: Easy to install spent fuel rod in test; Less linkages than in conventional bending test setup such as three-point or four-point bending; Target the failure mode relevant to the fracture of spent fuel rod in transportation by focusing on pure bending; The continuous calibrations and modifications resulted in the third generation (3G) U-frame testing setup. Rigid arms are split along the LBB axis at rod sample ends. For each arm, this results in a large arm body and an end piece. Mating halves of bushings were modified into two V-shaped surfaces on which linear roller bearings (LRB) are embedded. The rod specimen is installed into the test fixture through opening and closing slide end-pieces. The 3G apparently has addressed major issues of setup identified in the previous stage and been proven to be eligible to be further pursued in this project. On the other hand, the purchase of universal testing machine or Bose dual LM2 TB was completed and the testing system was delivered to ORNL in August 2012. The preliminary confirmation of the system and on-site training were given by Bose field engineer and regional manager on 8/1-8/2/2012. The calibration of Bose testing system has been performed by ORNL because the integration of ORNL setup into the Bose TestBench occurred after the installation. Major challenge with this process arose from two aspects: 1) the load control involves two load cells, and 2) U-frame setup itself is a non-standard specimen. ORNL has been able to implement the load control through Cycle Indirect along with pinning the U-frame setup. Two meetings with ORNL hot-cell group (November 2012 and January 2013) were held to discuss the potential issues with both epoxy mounting of rigid sleeve and U-frame setup. Many suggestions were provided to make the procedure friendlier to the manipulator in hot cell. Addressing of these suggestions resulted in another cycle of modifications of both vise mold and setup. The initial meeting with ORNL I&C group occurred in November 2012 with regard to the Bose cable modification and design of central panel to integrate the cables and wires. The first round of cable modification and central panel fabrication was completed in February 2012. The testing with the modified cables exhibited substantial noises and the testing system was not shown to be stable. It was believed the cross talk was responsible to the noise, and a central panel with a better grounding and shielding was highly recommended. The central panel has been re-designed and fabricated in March 2013. In the subsequent period, the ORNL made substantial effort to debug the noises with the load cell channel, and to resolve the noises and nonlinearity with RDP LVDTs related to the integration of RDP LVDTs to Bose system. At the same time, ORNL has completed the verification tests of Bose test system, including cycle tests under reversal bending in load control, bending tests under monotonic load, and cycle tests under reversal bending in load control on MTS machine to verify the results of Bose machine. These results are shown to be consistent under equivalent loading conditions, especially for the cycle tests. Rad hardened LVDTs will be incorporated into the Bose system once received, and 10 Hz tests will be completed in the next step. The schedule for the final check of the Bose system is being finalized before the system delivered to the hot cell
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