6,496 research outputs found

    Angular Distribution of Bremsstrahlung Produced by 10-keV and 20-keV Electrons Incident on a Thick Au Target

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    The relative intensities of the thick-target bremsstrahlung produced by 10-keV and 20-keV electrons incident on Au at forward angles ranging from 0 degrees to 25 degrees are compared. Following corrections for photon absorption within the target, the detected radiation appears to be distributed anisotropically only for photon energies, k, that are approximately equal to the initial energy of the incident electrons, E. The results are compared to the theoretical angular distributions of Kissel et al. [At. Data Nucl. Data Tables 28, 381 (1983)]. The comparison suggests that when k/E is approximately equal to 1, the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the theoretical angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets.Comment: The following article has been accepted by AIP Conference Proceedings (Vol. 1525). After it is published, it will be found at http://proceedings.aip.org

    Automation and robotics for the Space Exploration Initiative: Results from Project Outreach

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    A total of 52 submissions were received in the Automation and Robotics (A&R) area during Project Outreach. About half of the submissions (24) contained concepts that were judged to have high utility for the Space Exploration Initiative (SEI) and were analyzed further by the robotics panel. These 24 submissions are analyzed here. Three types of robots were proposed in the high scoring submissions: structured task robots (STRs), teleoperated robots (TORs), and surface exploration robots. Several advanced TOR control interface technologies were proposed in the submissions. Many A&R concepts or potential standards were presented or alluded to by the submitters, but few specific technologies or systems were suggested

    A database/knowledge structure for a robotics vision system

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    Desirable properties of robotics vision database systems are given, and structures which possess properties appropriate for some aspects of such database systems are examined. Included in the structures discussed is a family of networks in which link membership is determined by measures of proximity between pairs of the entities stored in the database. This type of network is shown to have properties which guarantee that the search for a matching feature vector is monotonic. That is, the database can be searched with no backtracking, if there is a feature vector in the database which matches the feature vector of the external entity which is to be identified. The construction of the database is discussed, and the search procedure is presented. A section on the support provided by the database for description of the decision-making processes and the search path is also included

    Analysis of ZDDP content and thermal decomposition in motor oils using NAA and NMR

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    Zinc dialkyldithiophosphates (ZDDPs) are one of the most common anti-wear additives present in commercially-available motor oils. The ZDDP concentrations of motor oils are most commonly determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). As part of an undergraduate research project, we have determined the Zn concentrations of eight commercially-available motor oils and one oil additive using neutron activation analysis (NAA), which has potential for greater accuracy and less sensitivity to matrix effects as compared to ICP-AES. The 31P nuclear magnetic resonance (31P-NMR) spectra were also obtained for several oil additive samples which have been heated to various temperatures in order to study the thermal decomposition of ZDDPs.Comment: Manuscript has been accepted for publication in Physics Procedia as part of the proceedings of the 23rd International Conference on Application of Accelerators in Research and Industry (CAARI 2014

    History Lesson-Part II

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    Hunger

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    Space and surface power for the space exploration initiative: Results from project outreach

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    The analysis and evaluations of the Space and Surface Power panel, one of eight panels created by RAND to screen and analyze submissions to the Space Exploration Initiative (SEI) Outreach Program, is documented. In addition to managing and evaluating the responses, or submissions, to this public outreach program, RAND conducted its own analysis and evaluation relevent to SEI mission concepts, systems, and technologies. The Power panel screened and analyzed submissions for which a substantial portion of the concepts involved power generation sources, transmission, distribution, thermal management, and handling of power (including conditioning, conversion, packaging, and enhancements in system components). A background discussion of the areas the Power panel covered and the issues the reviewers considered pertinent to the analysis of power submissions are presented. An overview of each of the highest-ranked submissions and then a discussion of these submissions is presented. The results of the analysis is presented
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