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Abstract  

Spent HTGR-fuel spheres were analysed chemically to determine their14C content.14C is mainly (∼96%) produced in the graphite matrix of the fuel. About 75% of the14C is derived from14N. More than 99% of14C is released as CO2 during the combustion of the fuel elements. Assuming no14C retention, the maximum body burden at the critical region of a 50000 MW HTGR reprocessing plant will be ∼ 70 mrem/a.

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Summary The properties and quality of silicate glasses strongly depend on the amount of residual dissolved gases. Thus, the knowledge of the quantitative content of different volatile components is of great relevance within the technical production line. Several applications exist for the detection and quantification of a single gas in glass. Up to now no available technique provides simultaneous and quantitative information on different gases in a single run. We have developed a new technique to detect the most common volatiles (H2O, CO2, SO2, O2 and N2) simultaneously and quantitatively in silicate glasses with the help of a modified Netzsch TG/MS system. One characteristic feature of this new method is the direct coupling of a thermo balance and a mass spectrometer without the use of any capillary or skimmer system.

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Abstract  

Differential scanning microcalorimetric measurements on phase transitions in water-oil-surfactant mixtures are presented, demonstrating that this method is highly sensitive towards small heat changes connected with structural transitions in the samples. The values for the latent heat of phase transitions are determined and the results are compared with predictions from mean field theory, emphasizing the role calorimetric experiments can play to identify the most important contributions to the free energy describing the mixtures. Doing this, the present status of the understanding of temperature dependent phase transitions in microemulsions is reviewed.

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Abstract  

A thermal neutron activation analysis technique has been developed for the analysis of terrestrial rocks and stony meteorites for trace elements. The main emphasis of the method is directed toward minimizing chemical procedures and maximizing the use of Ge(Li) gamma spectroscopy and computer data reduction. The validity of the technique is demonstrated by presenting data obtained for synthetic samples, U.S G.S. Standard Rocks and three ordinary chondrite meteorites for the following elements: As, Au, Co, Cs, Ga, Ge, Hg, Mo, Os, Re, Sb, Sc, Se, Te and Zn.

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Abstract  

The long-lived radionuclide 129I (T 1/2 = 15.7 My) occurs in the nature in very low concentrations. Since the middle of our century the environmental levels of 129I have been dramatically changed as a consequence of civil and military use of nuclear fission. Its investigation in environmental materials is of interest for environmental surveillance, retrospective dosimetry and for the use as a natural and man-made fracers of environmental processes. We are comparing two analytical methods which presently are capable of determining 129I in environmental materials, namely radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS). Emphasis is laid upon the quality control and detection capabilities for the analysis of 129I in environmental materials. Some applications are discussed.

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Cereal Research Communications
Authors:
P. Szakál
,
R. Schmidt
,
M. Barkóczi
,
R. Kalocsai
,
D. Beke
, and
O. Csatai
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Abstract

Peroral infection with Toxoplasma gondii results in a Th1-type immunopathology characterized by small intestinal necrosis and is dependent on IL-18. In the present study, we investigated whether treatment with IL-18 binding protein (IL-18bp) prevents ileal pathology. We observed increased expression of IL-18bp in intestinal biopsies of mice following infection. Whereas small intestines of control mice showed severe necrosis with complete destruction of the small intestinal architecture, mice treated with IL-18bp daily displayed only mild inflammatory changes including flattening of villi and edema in the space between the epithelium and lamina propria. Small intestinal parasite loads and concentrations of pro-inflammatory cytokines did not differ in control and IL-18bptreated mice. Binding of IL-18 to immobilized IL-18bp revealed a remarkably slow dissociation rate, indicating high affinity. Using chimeric mice we observed that bone marrow-derived rather than stromal cells were the primary source of IL-18 that resulted in small intestinal pathology following peroral infection with T. gondii. In conclusion, the results presented here suggest that IL-18bp may be an effective and safe treatment for small intestinal inflammation. Antigen-presenting rather than epithelial cells appear to be the main source of IL-18 in T. gondii-induced small intestinal inflammation.

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