Pellet cladding interaction — Evaluation of lubrication by graphite

Graphite CANLUB interlayers between UO₂ pellets and Zircaloy cladding increase the tolerance of fuel pins to power ramping defects. This paper evaluates the effectiveness of graphite as a lubricant in dry, low oxygen potential environments such as exist at the UO₂ — Zircaloy interface of an operating fuel pin. Two types of laboratory tests were performed at 573 ± 5 K in moist air and also dry inert gas. In the first test series, graphite-coated Zircaloy cladding was expanded by the outward movement of a 4-segment bronze mandrel. Depleting the oxygen and water vapour reduced circumferential failure strains from about 19% to about 12%, but there remained a large margin of improvement over the 4% failure strain attained with bare Zircaloy. In the second series of laboratory tests a disc of UO₂ was clamped between Zircaloy plates, and the force required to cause it to slide was measured as a function of normal loading with and without graphite lubrication. The coefficient of friction μ for graphite lubricating a Zircaloy-UO₂ interface rose only slightly from 0.19 to 0.24 on changing the gaseous environment from laboratory air to dry deoxygenated helium. These values were low compared with μ ~ 0.9 for bare Zircaloy-UO₂ interfaces in air or inert gas. An indirect evaluation was made of whether or not graphite acts as a lubricant in-service by counting peripheral radial UO₂ cracks in metallographic cross-sections of irradiated fuel pins. The number of peripheral cracks in highly powered fuel depends on the interfacial shear stress at the pellet-clad interface, and hence on the friction coefficient. In fuel pins ramped to a linear power of 55 kW/m there were, on average, 17 peripheral UO₂ cracks in graphite lubricated CANLUB fuel compared with 30 in bare Zircaloy-clad fuel. We deduce that the ratio of friction coefficients in-service (CANLUB graphite : bare Zircaloy) had been 0.57 : 1.0. Finally, we discuss theoretical limitations of CAN-LUB coatings and their implications regarding fuel design and performance.     

An international quality assurance scheme for the quantitation of daidzein and genistein in food,urine and plasma

This quality assurance (proficiency testing) scheme was commissioned to enable the Food Standards Agency (FSA) to determine the quality of analytical results submitted by researchers measuring the concentrations of phytoestrogens in foods and biological fluids in FSA-funded research projects, and also, to demonstrate that FSA-funded laboratories are producing consistent and precise results. Non-FSA-funded laboratories from around the world were also invited to join in the scheme to increase the number participants. A secondary objective was to highlight the most successful methodologies used to analyse phytoestrogens.     

Amide proton exchange measurements as a probe of the stability and dynamics of the N-terminal domain of the ribosomal protein L9: comparison with the intact protein

Amide H/D exchange rates have been measured for the N-terminal domain of the ribosomal protein L9, residues 1-56. The rates were measured at pD 3.91, 5.03, and 5.37. At pD 5.37, 18 amides exchange slowly enough to give reliable rate measurements. At pD 3.91, seven additional residues could be followed. The exchange is shown to occur by the EX2 mechanism for all conditions studied. The rates for the N-terminal domain are very similar to those previously measured for the corresponding region in the full-length protein (Lillemoen J et al., 1997, J Mol Biol 268:482-493). In particular, the rates for the residues that we have shown to exchange via global unfolding in the N-terminal domain agree within the experimental error with the rates measured by Hoffman and coworkers, suggesting that the structure of the domain is preserved in isolation and that the stability of the isolated domain is comparable to the stability of this domain in intact L9.     

Health economics and cost implications of anxiety and other mental disorders in the United States

BACKGROUND: Mental disorders impose a multi-billion dollar burden on the economy each year; translating the burden into economic terms is important to facilitate formulating policies about the use of resources. METHODS: For direct costs, data were obtained from national household interview and provider surveys; for morbidity costs, a timing model was used that measures the lifetime effect on current income of individuals with mental disorders, taking into account the timing of onset and the duration of these disorders, based on regression analysis of Epidemiologic Catchment Area study data. RESULTS: The total economic costs of mental disorders amounted to US$147.8 billion in 1990. Anxiety disorders are the most costly, amounting to $46.6 billion, or 31.5% of the total; schizophrenic disorders accounted for $32.5 billion, affective disorders for $30.4 billion, and other mental disorders for $38.4 billion. CONCLUSIONS: Mental illnesses, especially anxiety disorders, are costly to society. Although anxiety disorders have a higher prevalence than affective disorders and schizophrenia, use of medical care services is lowest for anxiety disorders. Anxiety disorders appear to be under-recognised and untreated even though treatment interventions have been shown to be effective and can be delivered in a cost-efficient manner.     

NIDA technical review: nitrite inhalants

Nitrite inhalants are commonly abused substances in the US and Europe. "Nitrite inhalants and AIDS" was a popular topic in the early 1980s when the cause of AIDS was not known. With the discovery of HIV, concern about nitrite use wained. However, nitrite inhalant use is associated with behavioral relapse and HIV transmission among gay men, with decreased lymphocyte counts and natural killer cell activity in laboratory studies, and remains a candidate "cofactor" in the pathogenesis of AIDS-related Karposi sarcoma. Discouraging nitrite use continues to be a worthwhile public health goal. Participants recommend specific research efforts.     

"Snatching defeat from the jaws of victory: Self-esteem differences in the experience and anticipation of success": Correction to Wood et al (2005).

Reports an error in "Snatching Defeat From the Jaws of Victory: Self-Esteem Differences in the Experience and Anticipation of Success" by Joanne V. Wood, Sara A. Heimpel, Ian R. Newby-Clark and Michael Ross (Journal of Personality and Social Psychology, 2005[Nov], Vol 89[5], 764-780). There are typographical errors in Table 2 (certain values should not have been in bold face). The corrected table is provided in the erratum. (The following abstract of the original article appeared in record 2005-15658-009.) Successes--defined broadly as meeting important standards or receiving positive evaluations--are widely assumed to be enjoyed equally by people with high self-esteem (HSEs) and low self-esteem (LSEs). Three studies examined the contradictory hypothesis that HSEs react more favorably to success than do LSEs and that success brings about certain unfavorable consequences for LSEs. Undergraduate participants reacted to a laboratory-manipulated success (Studies 1 and 2) or imagined highly positive events in the future (Study 3). Self-esteem differences emerged in anxiety, thoughts about the self, and (in Study 3) thoughts about non-self-related aspects of the event. LSEs were more anxious than HSEs after succeeding, success improved HSEs' self-relevant thoughts but not LSEs', and LSEs focused more on success's negative aspects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of nickel in the high-temperature oxidation of Fe-Cr-Ni alloys in oxygen

The oxidation of several largely austenitic Fe-Cr-Ni alloys in 1 atm oxygen at 800–1200°C has been studied thermogravimetrically, metallographically, and in detail by electron probe micro analysis. Fe-Cr-Ni alloys of this type are protected by Cr₂O₃-healed scale, which thickens slower than on the corresponding binary Fe-Cr and Ni-Cr alloys, presumably because nickel and iron ions dope the Cr₂O₃ more effectively together than singly and/or because the alloy composition and ability to absorb cation vacancies are such as to produce a smaller vacancy activity gradient or level in the scale, or voids within it. The scale adhesion, as on Ni-Cr alloys, is generally good after long times, at least partly due to the convoluted alloy-oxide interface, in some cases to large intergranular Cr₂O₃-rich stringers, and possibly to the general specimen mechanical properties. Nonprotective stratified scale development is relatively unusual and often produces nickel-rich, alloy-particle-containing nodules, as on Fe-Ni alloys. Careful selection of ternary and more complex alloys with appropriate alloy interdiffusion coefficients and oxygen solubilities and diffusivities should permit development of materials with the best compromise between ease of Cr₂O₃ establishment, avoidance of breakaway, and readiness of scale healing.     

Acetophenone as an Anti-attractant for the Western Pine Beetle, <Emphasis Type="Italic">Dendroctonus Brevicomis</Emphasis> LeConte (Coleoptera: Scolytidae)

Host location and colonization by bark beetles is dependent upon the relative and absolute amounts of attractant and antiattractant compounds available. Many investigations have lead to use of antiattractants for the management of these pests and have been especially focused on verbenone. However, recent studies have identified new antiattractants for several species of bark beetles. We report results of recent investigations of the response of western pine beetle, Dendroctonus brevicomis LeConte, to two recently identified antiattractants, acetophenone, and fenchyl alcohol, with verbenone as a standard of comparison, in northern California. Release of both acetophenone and verbenone resulted in significantly lower trap catches of D. brevicomis in aggregation pheromone-baited traps, while fenchyl alcohol was inactive. Acetophenone was the only antiattractant that did not reduce numbers of the most abundant predator of D. brevicomis, Temnochila chlorodia (Mannerheim), responding to the attractant pheromone of its prey. Aggregation pheromone-baited traps with acetophenone also had the highest predator/prey ratio. Our results suggest that acetophenone may be part of the intra- and interspecific interactions among sympatric species of bark beetles and may have application in their control.