4,165 research outputs found

    A LEED determination of the structures of Ru(001) and of CO/Ru(001)−(√3 × √3)R30°

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    The structures of Ru(001) and of the √3 × √3 R30° overlayer of CO on Ru(001) have been determined by LEED I–V measurements and comparison to calculations. Special attention was paid to accurate angular alignment, selection of a well-ordered portion of the surface, and avoidance of beam-induced changes of the CO layer. Five orders of reflexes over a range of 300 eV each were used for the clean surface and 7 orders over 200 eV each for the CO superstructure. For the clean surface, a slight contraction of the first layer spacing (by 2%) was found which gave r-factors of 0.04 (Zanazzi-Jona) and 0.16 (Pendry) for 5 non-degenerate beams. For the CO structure the most probable geometry is the on-top site with spacings d(Ru---C) = 2.0 ± 0.1 Åandd(C---O) = 1.10 ± 0.1 Å (rZJ = 0.21; rP = 0.51). The two threefold hollow and the bridge sites can be clearly excluded

    Radiation quality and radiation risks - some current problems

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    Antioxidant requirements of rats exposed to 100 % oxygen. Part 2 - Effects of dietary ascorbic acid

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    Dietary ascorbic acid effects as antioxidants in rats exposed to 100 percent oxyge

    Radiation Protection Group: Annual Report 2003

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    The RP Annual Report summarises the activities carried out by CERN’s Radiation Protection Group in the year 2003. It includes contribution from the EN section of the TIS/IE Group on environmental monitoring. Chapter 1 reports on the measurements and estimations of the impact on the environment and public exposure due to the Organisation’s activities. Chapter 2 provides the results of the monitoring of CERN’s staff, users and contractors to occupational exposure. Chapter 3 deals with operational radiation protection around the accelerators and in the experimental areas. Chapter 4 reports on RP design studies for the LHC and CNGS projects. Chapter 5 addresses the various services provided by the RP Group to other Groups and Divisions at CERN, which include managing radioactive waste, high-level dosimetry, lending radioactive test sources and shipping radioactive materials. Chapter 6 describes activities other than the routine and service tasks, i.e. development work in the field of instrumentation and research and support activities for future CERN projects or in RP-related domains

    Intellectual property as complex innovation projects component

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    The materials presented the possibilities development of intellectual property complex innovation projects modern highly effective science-based problems of improving the use of wastes of different industries on a complex enterprise that can provide all its energy needs alone. Some features of the possibilities of solving evidence-based problems of development of mechanisms for identifying syner-gistic processes, their scientific justification improving the use of wastes of different industries on a complex enterprise. The problem of wastes utilization and recycling is present as complex synergetic processes research and analysis of energy- and resource saving process-es for treatment of polymer wastes of various origin. The research focused on the study of issues such as the development of models of waste-modifying polymer. The investigation are focused in researching such problems as selection of scientific based methods of wastes to be utilized or recycled; the development of appropriated process flow sheets and choice of modifications additives and equipment for polymers waste recycling. The choice of appropriate plants with selected energy resources is very important for projects realization

    Proposal of a BEPU-FSAR

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    The accident analysis performance consists of a fundamental part of the licensing of the Nuclear Power Plants (NPP). There are conservative and best estimated methods to perform this analysis. Although Best Estimated Plus Uncertainty (BEPU) is used for qualified computational tools and methods of the accident analysis, it can be used in other parts of the Final Safety Analysis Report (FSAR), which require Analytical Techniques (AT). The need for uncertainty quantification and harmonization of the approaches to use the computer codes is an important issue constituting the background to perform a BEPU-FSAR. The objective of this paper is to present the BEPU-FSAR concept and discuss how-to and why-to perform it

    Relationships of low back outcomes to internal spinal load: a prospective cohort study of professional drivers

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    Purpose \u2013 To investigate the relationships between low back symptoms and alternative measures of external dose and internal spinal dose in professional drivers exposed to whole body vibration (WBV). Methods \u2013 The occurrence of low back symptoms were investigated in a cohort of 537 drivers over a two-year follow up period. Low back pain (LBP), individual characteristics, and work-related risk factors were investigated with a structured questionnaire. Exposure to WBV was evaluated by means of measures of external dose (daily vibration exposure in terms of either equivalent continuous acceleration over an eight-hour period (A(8)) or vibration dose value according to the EU Directive on mechanical vibration) and measures of internal lumbar load (daily compressive dose Sed and risk factor R according to ISO/CD 2631-5 2014). Results \u2013 In the drivers\u2019 cohort, the cumulative incidence of 12-month low back outcomes was 16.8% for LBP, 9.3% for chronic LBP, and 21.8% for sciatic pain. The measures of internal spinal load were better predictors of the occurrence of low back symptoms than the measures of daily vibration exposure. A two-fold increase in the risk estimates for low back outcomes was found in the upper quartile of the R factor (0.41-0.72 units) compared to the lower one (0.07-0.19 units). Conclusions \u2013 In this prospective cohort study, measures of internal spinal dose performed better than measures of daily vibration exposure (external dose) for the prediction of low back outcomes in professional drivers. The ISO boundary values of the risk factor R for low and high probabilities of adverse health effects on the lumbar spine tend to underestimate the health risk in professional drivers
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