Vol.16,

The beam-based alignment system is given in HLS (Hefei Light Source), in which a switchable shunt resistor was installed on quadrupole to bypass a small percentage of the magnet current. The system can measure BPM-to-quadrupole offset which can be used to position the beam in the magnetic center of quadrupoles. In measurement, some methods ( linear fitting with single corrector, parabola fitting with single corrector, linear fitting with local bump, and parabola fitting with local bump ) are used. These measurement results are given, and compared among the methods mentioned above.

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The thermal neutron capture gamma ray facility at Pakistan Research Reactor (PARR-1) is being used for the re-estimation of various properties like capture cross-sections, resonance integral, absolute gamma intensities, etc. of different isotopes. The data for gamma ray transitions from the capture of thermal neutrons by ⁵⁵Mn are not in good agreement specifically below 2 MeV. So there is a need to re-estimate its intensities with better accuracy. Analytical grade MnCl₂ powder and high purity Mn metal pieces were used in this study. Standard ¹⁵²Eu and ⁶⁰Co radioactive sources as well as thermal neutron capture γ-rays in chlorine were chosen for efficiency calibration. The k₀ standardization technique was applied for these measurements to eliminate systematic errors in efficiencies. Chlorine also acted as a comparator in k₀- factor calculations. The results have been tabulated for the main gamma rays from ⁵⁶Mn in the low as well as in the medium energy regions. The absolute intensities are in good agreement with most of the reported values.

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In recent years, novel structure SOI materials have been fabricated successfully. Also, SiGeOI (SGOI) material, an ideal substrate for realizing strained-silicon structures, has been investigated by modified SIMOX technology. From 2002, the 100 mm, 125 mm and 150 mm SIMOX wafers have been successfully produced by Shanghai Simgui Technology Co. Ltd, a commercial spin-off of Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), and shipped to the semiconductor industry worldwide. This paper presents an outlook for R & D on SOI technologies, and the recent status and future prospect of SIMOX wafers in China.

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In order to reveal the reactivity of a functional group in an aromatic compound having two substituents in the aromatic ring, the hydrogen-isotope exchange reaction (T-H exchange reaction) between tritiated water vapor (HTO vapor) and 4-amino-2-methylbenzenesulfonic acid (and 5-amino-2-methylphenol) were dynamically observed at 50℃ (and 70℃) in a gas-solid system. Consequently, the fact that the specific activity of the acid increased with time was obtained, and the T-for-H exchange reaction occurred. By applying the A"-McKay plot method to the data observed, the rate constant of each functional group for the reaction was obtained. After the additive property of the Hammett's rule was applied to this work, the new substituent constants were obtained. From the above-mentioned, the following four items have been confirmed: (1) the reactivity of the functional groups can be dynamically analyzed, and the A"-McKay plot method is useful to analyze the reactivity; (2) the additive property of the Hammett's rule is applicable to quantitative comparison of the reactivity of the functional groups; (3) the reactivity of the functional groups can be simultaneously analyzed by using the A"-McKay plot method in the T-H exchange reaction; and (4) the method used in this work is also useful for analyzing the reactivity of a certain material having some kinds of functional groups.

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Complex energy and environment system, especially nuclear fuel cycle system recently raised social concerns about the issues of economic competitiveness, environmental effect and nuclear proliferation. Only under the condition that those conflicting issues are gotten a consensus between stakeholders with different knowledge background, can nuclear power industry be continuingly developed. In this paper, a new analysis platform has been developed to help stakeholders to recognize and analyze various socio-technical issues in the nuclear fuel cycle system based on the functional modeling method named Multilevel Flow Models (MFM) according to the cognition theory of human being. Its character is that MFM models define a set of mass, energy and information flow structures on multiple levels of abstraction to describe the functional structure of a process system and its graphical symbol representation and the means-end and part-whole hierarchical flow structure to make the represented process easy to be understood. Based upon this methodology, a micro-process and a macro-process of nuclear fuel cycle system were selected to be simulated and some analysis processes such as economics analysis, environmental analysis and energy balance analysis related to those flows were also integrated to help stakeholders to understand the process of decision-making with the introduction of some new functions for the improved Multilevel Flow Models Studio, and finally the simple simulation such as spent fuel management process simulation and money flow of nuclear fuel cycle and its levelised cost analysis will be represented as feasible examples.

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With many advantages, hydrogen is considered as the fuel of the future. But there is no natural resource of hydrogen and it must be produced by other kinds of energy. As for the primary energy, nuclear energy is a promising alternative. Using heat from nuclear reactor to produce hydrogen is receiving more and more concerns in recent years. This paper mainly emphasizes the study of the direct contact pyrolysis (DCP) of methane using heat from nuclear reactor. A facility was designed to investigate the efficiency of DCP process in certain conditions. The experimental results show that this process produces only hydrogen and carbon. The conversion efficiency increases with temperature and residence time, but decreases as flow rate increases. The highest efficiency of DCP obtained in this experiment is about 22%.

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Samples of cement manufactured in Egypt and the raw materials have been analyzed using gamma-spectroscopy, in order to determine the concentration of natural radionuclides and associated radiological hazard. The mean of specific activity due to radionuclides of ²²⁶Ra, ²³²Th and ⁴⁰K was found to be (20±4), (11± 2), (320±18) (gypsum), (41±8), (27±5), (410±27) (clay), (58±11), (18±3), (321±20) (iron ore)and (37.6±6), (11.8±3), (178.6±15) Bq•kg^-1 (Portland cement), respectively. ⁴⁰K concentration could not be detected in slag, limestone, sulphate resistant cement (S.R.C.), clinker and white cement, while the mean specific activities of ²²⁶Ra and ²³²Th are (239±16), (48.7±7); (31.5±5), (10±2); (47±7), (20±5); (23±5), (10.4±3) and (23±5), (11±3) Bq•kg^-1, respectively. The activities (concentrations) are in the same range as the data released in other countries. The calculated radiation hazard parameters for all the samples are still lower than the acceptable values in Egypt and other countries.

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