Results 1 - 10 of 335
Results 1 - 10 of 335. Search took: 0.02 seconds
|Sort by: date | relevance|
[en] This standard gives guidance for application of the modernized metric system in the United States. The International System of Units, developed and maintained by the General Conference on Weights and Measures (abbreviated CGPM from the official French name Conference Generale des Poids et Measures) is intended as a basis for worldwide standardization of measurement units. The name International System of Units and the international abbreviation SI2 were adopted by the 11th CGPM in 1960. SI is a complete, coherent system that is being universally adopted
[en] Full text of publication follows: The international system of units (S.I.) enables dosimetry and activity measurements to be understood world-wide. The traceability of such measurements to the S.I. units of the gray, sievert and becquerel is assured through international comparisons at the primary level of measurement with the International Bureau of Weights and Measures (B.I.P.M.). Confidence in the dissemination of measurement standards to secondary levels and end users is assured through the calibration and measurement capabilities (C.M.C.) of the national metrology institutes (N.M.I.) and through their accredited laboratories. The International Committee of Weights and Measures (C.I.P.M.) set up an arrangement in 1999 for the mutual recognition of these calibration and measurement capabilities (C.I.P.M. M.R.A.) that now been signed by the officials of 62 countries and 2 international organizations, the International Atomic Energy Association (IAEA) and the Institute for Reference Materials and Measurements (I.R.M.M.). In the field of dosimetry, 49 international comparisons, 25 of which are for neutron measurements, are now registered in the key comparison database (K.C.D.B.). These comparisons support in part the 419 C.M.C. currently listed in Appendix C of the C.I.P.M. M.R.A. that is also maintained in the K.C.D.B.. In the field of activity measurements, there are 101 international comparisons, supporting the 1959 C.M.C. registered. These numbers are growing each year as more countries join the C.I.P.M. M.R.A. and more laboratories submit their C.M.C.. The C.M.C. are reviewed rigorously by international experts before being voted on and accepted for registration in the K.C.D.B.. The uncertainties associated with the C.M.C. are obviously related through the traceability chain to the N.M.I. standards. Examples of the results of various international comparisons of these national standards organized b y the B.I.P.M. are presented to indicate the level of measurement uncertainty that is achievable at the highest level. (authors)
[en] This book contains the DIN prescriptions for expressions of physical terms and SI units. In addition the physical terms of the International Electrotechnical Dictionary are presented. (HSI)
[de]Dieses Buch enthaelt die DIN-Vorschriften fuer Ausdruecke von physikalischen Begriffen und SI-Einheiten. Zusaetzlich werden die physikalischen Begriffe des internationalen elektrotechnischen Woerterbuchs vorgestellt. (HSI)
[en] A brief biography of the physicist, Antoine-Henri Becquerel, is given. This is the first in a series of three biographies of the men who have been honoured by the use of their names for the SI units for activity (Becquerel), absorbed dose (Gray) and dose equivalent (Sievert). (U.K.)
[en] It is shown how interconversion between SI and Gaussian systems in electromagnetism can be done efficiently and in a way that does not appear arbitrary. A short discussion is given of the advantages of being able to work in both systems in electromagnetism, and multiple unit systems more generally. (paper)
[en] This dictionary facilitates correct handling of technical terms in electrical engineering. The essential enlargement of vocabulary in this edition offers a well-founded basis of the electrotechnical terms for education as well as for everyday use. An appendix with frequently used phrases complements this dictionary together with the ''International System of Units''.
[de]Dieses Woerterbuch erleichtert den fachlich korrekten Umgang mit Fachausdruecken der Elektrotechnik. Die wesentliche Erweiterung des Wortschatzes in dieser Auflage bietet eine fundierte Basis der elektrotechnischen Begriffe sowohl fuer die Ausbildung, als auch die alltaegliche Anwendung. Ein Anhang mit haeufig benutzten Redewendungen ergaenzt zusammen mit dem ''International System of Units'' dieses Woerterbuch.
[en] The ability of irradiated tissue to support bony growth remains poorly defined, although there are anecdotal cases reported showing mixed results for the use of mandibular distraction osteogenesis after radiation for head and neck cancer. Many of these reports lack objective measures that would allow adequate analysis of outcomes or efficacy. The purpose of this experiment was to utilize a rat model of mandibular distraction osteogenesis after high dose and highly fractionated radiation therapy and to evaluate and quantify distracted bone formation under these conditions. Male Sprague–Dawley rats underwent 12 fractions of external beam radiation (48 Gray) of the left mandible. Following a two week recovery period, an external frame distractor was applied and gradual distraction of the mandible was performed. Tissue was harvested after a twenty-eight day consolidation period. Gross, radiologic and histological evaluations were undertaken. Those animals subjected to pre-operative radiation showed severe attenuation of bone formation including bone atrophy, incomplete bridging of the distraction gap, and gross bony defects or non-union. Although physical lengthening was achieved, the irradiated bone consistently demonstrated marked damaging effects on the normal process of distraction osteogenesis. This murine model has provided reliable evidence of the injurious effects of high dose radiation on bone repair and regeneration in distraction osteogenesis utilizing accurate and reproducible metrics. These results can now be used to assist in the development of therapies directed at mitigating the adverse consequences of radiation on the regeneration of bone and to optimize distraction osteogenesis so it can be successfully applied to post-oncologic reconstruction