Microstructure evolution of a 10Cr heat-resistant steel during high temperature creep

The microstructure evolution of a 10Cr ferritic/martensitic heat-resistant steel during creep at 600°C was investigated in this work. Creep tests demonstrated that the 10Cr steel had higher creep strength than conventional ASME-P92 steel at 600°C. The microstructure after creep was studied by transmission electron microscopy, scanning electron microscopy and electron probe microanalysis. It was revealed that the martensitic laths were coarsened with time and eventually developed into subgrains after 8354 h. Laves phase was observed to grow and cluster along the prior austenite grain boundaries during creep and caused the fluctuation of solution and precipitation strengthening effects, which was responsible for the two slope changes on the creep rupture strength vs rupture time curve. It was also revealed that the microstructure evolution could be accelerated by stress, which resulted in the lower hardness in the deformed part of the creep specimen, compared with the aging part.

Measuring inconsistency in network intrusion rules

In this preliminary case study, we investigate how inconsistency in a network intrusion detection rule set can be measured. To achieve this, we first examine the structure of these rules which incorporate regular expression (Regex) pattern matching. We then identify primitive elements in these rules in order to translate the rules into their (equivalent) logical forms and to establish connections between them. Additional rules from background knowledge are also introduced to make the correlations among rules more explicit. Finally, we measure the degree of inconsistency in formulae of such a rule set (using the Scoring function, Shapley inconsistency values and Blame measure for prioritized knowledge) and compare the informativeness of these measures. We conclude that such measures are useful for the network intrusion domain assuming that incorporating domain knowledge for correlation of rules is feasible.

A Spitzer space telescope study of Sn 2002hh: An infrared echo from a Type IIP supernova

We present late-time ( 590 - 994 days) mid-IR photometry of the normal but highly reddened Type IIP supernova SN 2002hh. Bright, cool, slowly fading emission is detected from the direction of the supernova. Most of this flux appears not to be driven by the supernova event but instead probably originates in a cool, obscured star formation region or molecular cloud along the line of sight. We also show, however, that the declining component of the flux is consistent with an SN-powered IR echo from a dusty progenitor CSM. Mid-IR emission could also be coming from newly condensed dust and/or an ejecta/CSM impact, but their contributions are likely to be small. For the case of a CSM-IR echo, we infer a dust mass of as little as 0.036 M-. with a corresponding CSM mass of 3.6(0.01/ r(dg)) M-., where rdg is the dust-to-gas mass ratio. Such a CSM would have resulted from episodic mass loss whose rate declined significantly about 28,000 years ago. Alternatively, an IR echo from a surrounding, dense, dusty molecular cloud might also have been responsible for the fading component. Either way, this is the first time that an IR echo has been clearly identified in a Type IIP supernova. We find no evidence for or against the proposal that Type IIP supernovae produce large amounts of dust via grain condensation in the ejecta. However, within the CSM-IR echo scenario, the mass of dust derived implies that the progenitors of the most common of core-collapse supernovae may make an important contribution to the universal dust content.

No evidence of morphine analgesia to noxious shock in the shore crab, Carcinus maenas

A number of criteria have been suggested for testing if pain occurs in animals, and these include an analgesic effect of opiates (Bateson, 1991). Morphine reduces responses to noxious stimuli in crustaceans but also reduces responsiveness in a non-pain context. Here we use a paradigm in which shore crabs receive a shock in a preferred dark shelter but not if they remain in an unpreferred light area. Analgesia should thus enhance movement to the preferred dark area because they should not experience 'pain'. However, morphine inhibits rather than enhances this movement even when no shock is given. Morphine produces a general effect of non-responsiveness rather than a specific analgesic effect and this could also explain previous studies claiming analgesia. However, we question the utility of this criterion of pain and suggest instead that behavioural criteria be employed. (C) 2011 Published by Elsevier B.V.

THE EFFECT OF RAPID NEUTRAL-NEUTRAL REACTIONS ON CHEMICAL-MODELS OF DENSE INTERSTELLAR CLOUDS

Recent experiments on rapid neutral-neutral reactions involving the radical CN at low temperature and the neutral C atom at room temperature suggest that atom-neutral and radical-neutral reactions may be generally more rapid at low temperature than hitherto thought. We have included a variety of rapid neutral-neutral reactions in our gas-phase chemical models of quiescent, dense interstellar clouds. We find the calculated abundances of many molecules to be greatly changed from previous values. In particular, the peak 'early-time' abundances of organic molecules are reduced.

Donor identification and consent for deceased organ donation: summary of NICE guidance.

Organ donation plays a major role in the management of patients with single organ failure of the kidneys, liver, pancreas, heart, or lung, or with combined organ failure of heart and lung (such as in cystic fibrosis) or of kidney and pancreas (such as in diabetes). A shortage of transplant organs has resulted in long waits for transplantation. Currently about 500 people in the United Kingdom die each year because of a shortage of donated organs,1 and at 31 March 2011 almost 7000 patients were waiting for a kidney transplant1 and would be having costly dialysis with serious morbidity and impact on quality of life. This shortage of organs is partly the result of relatively low numbers of road traffic deaths (lower than in many countries) but is also the result of inefficiencies in the donor identification and consent processes. This article summarises the most recent recommendations from the National Institute for Health and Clinical Excellence (NICE) on improving donor identification and consent rates for deceased organ donation.2

Electron impact excitation of Kr XXVIII

Collision strengths (Ω ) are calculated for all 6328 transitions among the lowest 113 levels belonging to the 2s22p5,2s2p6,2s22p43ℓ,2s2p53ℓ, and 2p63ℓ configurations of fluorine-like krypton, Kr XXVIII, using the Dirac Atomic R -matrix Code. All partial waves with angular momentum J⩽40 are included, sufficient for the convergence of Ω for forbidden transitions. For allowed transitions a top-up is employed to obtain converged values of Ω up to an energy of 400 Ryd. Resonances in the thresholds region are resolved on a narrow energy mesh, and results for effective collision strengths (ϒ) are obtained after averaging the values of Ω over a Maxwellian distribution of electron velocities. Values of ϒ are reported over a wide temperature range below View the MathML source, and the accuracy of the results is assessed. In addition, effective collision strengths are listed for the temperature range View the MathML source, obtained from non-resonant collision strengths generated with the FAC code.

Nanocrystalline SnO2-based, UVB-activated, colourimetric oxygen indicator

Nanocrystalline SnO2, ncSnO(2), is used as a photosensitiser in a colourimetric O-2 indicator that comprises a sacrificial electron donor, glycerol, a redox dye, methylene blue (MB), and an encapsulating polymer, hydroxyethyl cellulose (HEC). Upon exposure to a burst of UVB light the indicator is activated (photo-bleached) as the MB is photoreduced by the ncSnO(2) particles. In the absence of oxygen, the film stays bleached, but recovers its original colour upon exposure to oxygen. Unlike its TiO2-based predecessor, the HEC/glycerol/MB/ncSnO(2) O-2 indicator is not activated by UVA light from white fluorescent lamps, but is by UVB light. This feature provides much greater control in the activation of the indicator. Other work shows the rate of activation depends upon I-0.75, where I is the UVB irradiance, indicating a partial dependence upon the electron-hole recombination process. The half-life of the recovery of the original colour of a UV-activated film, t(50), is directly proportional to the ambient level of oxygen. The advantages of using this indicator in modified atmosphere packaging as a possible quality assurance indicator are discussed briefly. (c) 2008 Elsevier B.V. All rights reserved.

Current and possible future methods of assessing the activities of photocatalyst films

The continuing interest in semiconductor photochemistry, SPC, and the emergence of commercial products that utilise films of photocatalyst materials, has created an urgent need to agree a set of methods for assessing photocatalytic activity and international committees are now meeting to address this issue. This article provides a brief overview of two of the most popular current methods employed by researchers for assessing SPC activity. and one which has been published just recently and might gain popularity in the future, given its ease of use. These tests are: the stearic acid (SA) test, the methylene blue (MB) test and the resazurin (Rz) ink test, respectively. The basic photochemical and chemical processes that underpin each of these tests are described, along with typical results for laboratory made sol-gel titania films and a commercial form of self-cleaning glass, Activ (TM). The pros and cons of their future use as possible standard assessment techniques are considered. (C) 2007 Elsevier B.V. All rights reserved.