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1.
Decomposition of dichlorodifluoromethane in thermal plasma was investigated theoretically by computing the equilibrium composition of the gas mixtures involving carbon, chlorine and fluorine in presence of argon (which is assumed to be the main plasma gas) and/or in addition of hydrogen and calcium together with hydrogen. The calculations were carried out for the temperature range between 500 and 6000 K and for the total pressure of the system of 1 bar. Use is made of the fact that a thermal plasma is a plasma in (local) thermal equilibrium, which makes possible the theoretical determination of its equilibrium composition at definite temperature by employing Gibbs free energy data for the compounds present in the system and assuming that the equilibrium of the system corresponds to its minimum energy state. The results of calculations show that toxic molecules and radicals can be, under convenient conditions (appropriate temperature and amount of added substances), converted into stable non-toxic species like CaF2 and CaCl2.  相似文献   

2.
Summary The International Data Centre of the Comprehensive Nuclear-Test-Ban Treaty Organisation receives atmospheric radioactivity data from the monitoring stations of the International Monitoring System. The Centre is a processing hub through which raw data and analysis results flow to Treaty Member States. Data are processed automatically upon receipt, and then interactively reviewed and screened for detection of CTBT-relevant radionuclides. Atmospheric back-tracking for source location is included in the IDC functions. This paper describes the role of the IDC in this verification effort, the types of radionuclide monitoring data received, the automatic and interactive processing, and the products distributed to Member States.  相似文献   

3.
Summary {\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\f0\fs20 Principle and technical development of low temperature calorimetry are described. Typical experimental results obtained by our group at Osaka University over the four decades are given. These include phase transitions in equilibrium crystals and glass transitions in non-equilibrium frozen-in disordered solids including crystals. It can be concluded that the glass transitions observed exclusively in liquids so far are just one example of transitions that must be of wide occurrence in solids arising from freezing of relevant degrees of freedom. Interplay between the phase and glass transitions in crystals is discussed in relation to useful dopant that may accelerate some molecular motions that had failed to maintain equilibrium at low temperatures. \par }  相似文献   

4.
A novel method for the determination of the point of micellar saturation has been developed. To exemplify the theory a model system was considered, this being the saturation of two aqueous micellar solvents with dimethyl phthalate ester (DMP). Upon addition of a hydrophobic compound to an aqueous micellar system partitioning will occur. On further addition, the inner hydrophobic regions will eventually be unable to accommodate any more DMP and, at this specific concentration, the micelle is saturated. With a comparatively large enthalpy change upon partitioning the point of saturation can be determined by a corresponding significant reduction in enthalpy change.  相似文献   

5.
Summary {\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\f0\fs24 We have developed a method for analyzing neutron activated sample data by using Microsoft Excel as the analysis engine. A simple technique for inputting data is based on report files generated by Canberra’s Genie-2000 spectroscopy system but could be easily modified to support other vendors having report formats with consistent text placement. A batch program handles operating an automatic sample changer, acquiring the data, and analyzing the spectrum to create a report of the peak locations and net area. The entire report is then transferred to within an Excel spreadsheet as the source data for neutron activation analysis. Unique Excel templates have been designed, for example, to accommodate short-lived and long-lived isotopes. This process provides us with a largely integrated solution to NAA while providing the results in an industry standard spreadsheet format. This software is ideally suited for teaching and training purposes. \par }  相似文献   

6.
Summary {\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\f0\fs24 Multi-pass pebble bed reactors are loaded with spherical fuel pebbles that are circulated through the core until they reach a proposed burnup limit (~100,000 MWD/MTU). An HPGe detector can be used to assay the fuel on-line to ensure that the burnup limit is not breached. The potential exists for using a relative burnup indicator, which would allow the use of a relative self-calibrating approach for efficiency determination. The utilization of several fission products as built-in on-line relative calibration standards is explored using the computer codes ORIGEN2.1, MCNP4C, and SYNTH to produce simulated gamma-ray spectra of the fuel pebbles at various levels of burnup. \par }  相似文献   

7.
Summary A pseudo-isothermal method for the kinetic analysis was applied to the recrystallisation of to nickel sulphide based on the Ozawa model for non-isothermal crystallisation in the presence of pre-existing nuclei. The aim of the analysis was to determine the number of steps involved in the recrystallisation and, hence, determine the applicability of the kinetic equation based on a single step mechanism, as is commonly applied in the kinetic analysis of solid-state processes using thermal methods. The kinetic analysis yielded evidence of at least two processes indicating that physical and mechanistic significance should not be drawn from the use of a single step approximation of the rate equation.  相似文献   

8.
Summary {\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\f0\fs24 The Center for Engineering Applications of Radioisotopes (CEAR) has been working for about ten years on the Monte Carlo - Library Least-Squares (MCLLS) approach for treating the nonlinear inverse analysis problem for PGNAA bulk analysis. This approach consists essentially of using Monte Carlo simulation to generate the libraries of all the elements to be analyzed plus any other required libraries. These libraries are then used in the linear Library Least-Squares (LLS) approach with unknown sample spectra to analyze for all elements in the sample. The other libraries include all sources of background which includes: (1) gamma-rays emitted by the neutron source, (2) prompt gamma-rays produced in the analyzer construction materials, (3) natural gamma-rays from K-40 and the uranium and thorium decay chains, and (4) prompt and decay gamma-rays produced in the NaI detector by neutron activation. A number of unforeseen problems have arisen in pursuing this approach including: (1) the neutron activation of the most common detector (NaI) used in bulk analysis PGNAA systems, (2) the nonlinearity of this detector, and (3) difficulties in obtaining detector response functions for this (and other) detectors. These problems have been addressed by CEAR recently and have either been solved or are almost solved at the present time. We have now finished the development of Monte Carlo simulation for all of the libraries except the prompt gamma-ray library from the activation of the NaI detector. We must first determine a treatment for the coincidence schemes for Na and particularly I to complete the Monte Carlo simulation of this last library. \par }  相似文献   

9.
Summary {\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\lang2057\f0\fs24 In many laboratories the number of measured routine gamma-spectra can be significant and the labour work to review all the data is time consuming and expensive task. In many cases the routine sample does not normally contain radiation above a detectable level, and still the review of the spectra has to be performed. By introducing simple rules for emerging conditions, the review work can be significantly reduced. In one case the need to review the environmental measurement spectra was reduced to less than 1% compared to the original need, which in turn made the review personnel available for more useful functions. Using the \scaps UniSampo\scaps0 analysis system, the analysis results of spectra that are causing alarming conditions can be transmitted via e-mail to any address. Some systems are even equipped with the capability to forward these results to hand-portable telephones or pagers. This is a very practical solution for automated environmental monitoring, when the sample spectra are collected automatically and transmitted to central computer for further analysis. The paper describes how to set up an automatic analysis system, rules for the emerging conditions, technical solutions for an automated alarming system and a generic hypothesis test for the alarming system developed for \scaps UniSampo\scaps0 analysis software. \par }  相似文献   

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