Nuclear research

J. B. EusseU ia Generic Techniques in System KeliahilityAssessment, Office of Nuclear Regulatory Research, Nuclear Regulatory Commission, Washiagton, D.C., 1976. 

All NAA experiments are conducted in two steps irradiation and counting as indicated in Figure 1. Samples are made radioactive by placing them in a neutron field. Typically a research nuclear reactor provides the necessary neutron flux. Elements present in the sample capture neutrons, and often become radioactive isotopes. This part of the experiment is known as irradiation. A typical irradiation in a reac-... 

Mass spectrometers Molecular beam apparatus Ion sources Particle accelerators Electron microscopes Electron diffraction apparatus Vacuum spectographs Low-temperature research Production of thin films Surface physics Plasma research Nuclear fusion apparatus Space simulation Material research Preparations for electron microscopy... 

The investigation of the physical properties of biologically important bilayer structures is one of the key items of current research. Nuclear magnetic relaxation work attempts to determine three different types of information in this field ... 

Research nuclear reactors use thermal neutrons to induce fission in a critical mass of to produce high-energy (fast, or hot) neutrons ... 

As shown above, neutrons are in particular important for studies of hydride materials. Neutrons can be produced either in nuclear reactors or by pulsed (spallation) neutron sources. In the research nuclear reactors neutrons are produced by fission processes based on U-235 (which is 0.7% in natural uranium, but usually emiched as fuel for reactors). Since the released neutrons from these processes are very energetic, the required chain reaction for continuous production of neutrons requires moderation (to reduce the energy)... 

This work was supported by the NSF Grants DEB-77-19273 and PHY-78-01684. Partial support for one of the authors was provided by the Director, OflSce of Energy Research, Nuclear Sciences of the Basic Energy Sciences Program of the U.S. Department of Energy under Contract W-7405-ENG-48. 

Two less commonly used techniques. X-ray fluorescence (XRF) and neutron activation analysis (NAA) have the advantage that as-received samples can be analyzed, glasses as well as solutions. Both are more expensive than the previously mentioned techniques, The NAA technique that produces the greatest sensitivity requires irradiation in a research nuclear reactor and hence is really practical only when detection of low levels of unusual cations is required. 

Gove, H., Kubik, R, Sharma, R, Datar, S., Fehn, U., Hossain,T, Koffer, X, Lavine, X, Lee, S., Ehnore, D. (1990) Applications of AMS to electronic and silver halide imaging research. Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms, 52,502-506. 

Production, utilization, and research nuclear facilities and activities were generally regulated for nuclear safety through the AEC Program or AEC Site Office. 

SPE Safety and Health with Plastics, National Technical Conference. Denver, Colorado, Nov. 1977 Indian Board of Research Nuclear Science India. Polymers and Radiation Symposium, Jugnrat, Feb. 1979 (see also refs. 2 and 3, and pp. 113, 299, 381 and 401 in ref. 79). 

Since many aliphatic PEMs were prepared from some new synthesized polymers in researches, nuclear magnetic resonance (NMR) is a useful tool to characterize the molecular structure of these polymers. In most cases, it was used to verify the coherence of the designed and actual structure of the new polymer [41,47]. Sometimes, it has also been used to identify a series of new polymers, when the researchers need to study on the effect of polymer structure on the properties of PEMs [65]. Confirmation of quaternization was also done by IH NMR spectroscopy (Figure 10.4), such as in cross-linked quaternized PVA (QPVA) [66] and cross-linked quaternized-CS [67] AEMs by observing the chemical shifts (ppm) of related functional groups (OH, CH, CH3) or increase in these peak intensities. 

M. Suzuki and H. Saitou, Light Water Reactor Fuel Analysis Code FEMAXI-6 (Ver.l) Detailed Structure and User s Manual, Department of Reactor Safety Research, Nuclear Safety Research Center, Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI)... 

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