Effect of Heating Rates and Composition on the Thermal Decomposition of Nitrate Based Molten Salts

AbstractA detailed analysis on the thermal degradation of nitrate based molten salts evaluating the influence of different impurities and heating rates in their maximum working temperature is presented. Determining the maximum operating temperature is of interest when searching for new heat transfer fluids (HTF) for high temperature solar thermal applications as it limits the thermodynamic efficiency of the power block. Thermogravimetric analysis is performed on potassium nitrate, sodium nitrate, sodium nitrite, the binary system Solar Salt, and the ternary Hitec. The kinetics of the thermal decomposition reactions are investigated through iso-conversional analysis. The effect of adding some common impurities such us NaCl and Na2CO3 on the multi-component nitrate salts is evaluated. It was found that impurities such as Na2CO3 can enhance the thermal stability of Hitec salt, leading to higher thermal decomposition temperatures. For solar salt, impurities such as NaCl can enhance the thermal stability of solar salt at 10K·min-1, while adding Na2CO3 can have the opposite effect. For nitrate based molten salts used in TES and HTF systems in CSP a reduction on the purity required for the materials can present some operational advantages besides cost reduction

CLASSIFICATIONS SYNDROMIQUES ET CLASSIFICATIONS PSYCHOPATHOLOGIQUES : MALADIE ET SUJET

International audienceSyndromic classifications and psychopathological classifications: illness and subject. Psychiatry and clinical psychology are confronted with the dual problem of describing illnesses and giving an account of the psychic functioning and evolution of a patient throughout his history and therapy. Syndromic classifications are essential for furnishing information on the nature, origin and development of disorders and can have a predictive value. Conversely, typological classifications often stemming from psychodynamic or phenomenological theories allow us to study more closely the subject's evolution; he is no longer referred to as suffering from a psychosis but as being psychotic. The opposition of these classifications and these languages must by discussed on epistemological, psychopathological and pragmatic levels.Psychiatrie et psychologie clinique sont confrontées au double problème de décrire des mala-dies et de rendre compte du fonctionnement psychique et de l'évolution d'un patient au cours de son histoire et de la thérapie. Les classifications syndromiques sont essentielles pour fournir des informations sur la nature, l'origine et le développement des troubles et peuvent posséder une valeur prédictive. A l'inverse, les classifications typologiques souvent issues des théories psychodynamiques ou phénoménologiques permettent de mieux étudier l'évolution d'un sujet dont on ne dira plus qu'il a une psychose mais qu'il est psychotique. L'opposition entre ces classifications et ces langages doit être discutée sur les plans épistémologique, psychopatholo-gique et pragmatiqu

Freeform Optical Surfaces: Report from OSA's First Incubator Meeting

Just as business incubator programs are designed to support the development of fledgling companies, OSA?s new incubator meeting series is structured to encourage the growth of exciting new areas within optics. The first one was devoted to the topic of freeform optics-a field that is actively evolving due to recent technological advances

K^0-\bar{K}^0 mixing in the Standard Model from Nf=2+1+1 Twisted Mass Lattice QCD

We present preliminary results at {\beta} = 1.95 (a = 0.077 fm) on the first unquenched N_f=2+1+1 lattice computation of the B_K parameter which controls the neutral kaon oscillations in the Standard Model. Using N_f=2+1+1 maximally twisted sea quarks and Osterwalder-Seiler valence quarks we achieve O(a) improvement and a continuum-like renormalization pattern for the four-fermion operator. Our results are extrapolated/interpolated to the physical light/strange quark mass but not yet to the continuum limit. The computation of the relevant renormalization constants is performed non perturbatively in the RI'-MOM scheme using dedicated simulations with N_f=4 degenerate sea quark flavours produced by the ETM collaboration. We get B_K^{RGI} (a = 0.077) = 0.747(18), which when compared to our previous unquenched N_f=2 determination and most of the existing results, suggests a rather weak B_K^{RGI} dependence on the number of dynamical flavours. We are at the moment analysing lattice data at two additional {\beta} values which will allow us to perform an extrapolation to the continuum limit.Comment: 7 pages, 8 figures, Proceedings of Lattice 2011, XXIX International Symposium on Lattice Field Theory, Squaw Valley, Lake Tahoe, Californi

Psychopathologie des conduites à risques

International audienceDescription of risk-taking behaviours (repeated suicide attempts, addictions with or without drugs, some sports activities, some forms of car driving, some games as " russian rulet ") shows two possibilities: risk denial (non recognition of risk) and risk challenge (recognition of risk). From a clinical point of view, the description of those behaviours needs the recognition of difference between post-modern cultural activities and pathological behaviours. Concept of " risk " was not regarded as a good principle of classification before, and the class of " risk taking behaviours " is a new category of diseases. In the past, risk-taking behaviours have been considered as indirect self-destructive behaviours or as addictions. Now, that class of pathological behaviours is autonomous and requires, as characteristic, the active search of danger without precaution. Generally, risk-taking behaviours begin with an " initiation experience " , which is keeping a high psychical importance, patients trying to obtain the same satisfaction by repetition of acts. Psychopathological interpretation leads to different patterns: 1/ sensation seeking, and opposition between sensations and emotions, 2/ mastery of libidinal excitation, 3/ " ordalic " behaviour, and 4/ new libidinal economy and repetition. The first conception is based on Zuckerman theory (" sensation seeking theory "). Some patients may experience a low level of cortical arousal and risk-taking behaviours may help them in producing excitation. This theory could explain some parts of those behaviours. But an additional factor is necessary: the opposition between sensations (physiological) and emotions (psychical, affects, feelings). The main problem is that taking risk patients suffer from experiencing emotions, which threaten them and try to avoid them in producing high sensations. The theory of mastery of libidinal excitation develops the idea that object relationship are threatening the subject who seems unconsciously depending on the libidinal object. Jeammet, Marcelli insist on the default of " narcissic seating " or on the fragility of primary narcissism among those patients. In front of the excitation induced by libidinal objects, a psychical working out is impossible. So the patient tries to control or to avoid the excitation by some acts (acting out). Pleasure of risk-taking behaviours derives from the physical sensations and, above all, from the victory on the power of the libidinal object. Secondary, the pleasure is depending from the attitude of the others: fascination, connection with a group of initiate persons. The theory of ordalic behaviour insists on the problem of identity. Ordalic behaviours are considered as repeated.La clinique des conduites à risques (tentatives de suicide répétées, addictions avec ou sans produit, certaines conduites sexuelles, certains sports, certaines conduites automobiles, jeux, roulette russe...) montre qu'à côté de situations de méconnaissance (déni du risque), existent bien des comportements dans lesquels le défi du risque est une condition nécessaire. L'interprétation psychopathologique fait appel à quatre modèles différents mais complémentaires : recherche de sensations en maintenant une opposition entre sensations (physiques) et émotions (élaborées psychiquement), tentative de maîtrise de l'excitation provoquée par l'objet libidinal, conduite ordalique permettant un « auto-engendrement » et addiction (économie parallèle de réduction du désir au besoin). Ces modèles ont en commun l'existence de troubles identitaires, la promotion d'une coïncidence avec le Moi-idéal, et de tenter d'éviter l'assujettissement à l'objet

K^0-\bar{K}^0 Mixing Beyond the SM from Nf=2 tmQCD

We present preliminary results on the of neutral kaon oscillations in extensions of the Standard Model. Using Nf=2 maximally twisted sea quarks and Osterwalder-Seiler valence quarks, we achieve both O(a)-improvement and continuum-like renormalization pattern for the relevant four-fermion operators. We perform simulations at three values of the lattice spacing and extrapolate/interpolate our results to the continuum limit and physical light/strange quark mass. The calculation of the renormalization constants of the complete operator basis is performed non- perturbatively in the RI-MOM scheme.Comment: 7 pages, 2 figures; presented at the XXVIII International Symposium on Lattice Field Theory Villasimius, Sardinia, Ital

Kaon oscillations in the Standard Model and Beyond using Nf=2 dynamical quarks

We compute non-perturbatively the B-parameters of the complete basis of four-fermion operators needed to study the Kaon oscillations in the SM and in its supersymmetric extension. We perform numerical simulations with two dynamical maximally twisted sea quarks at three values of the lattice spacing on configurations generated by the ETMC. Unwanted operator mixings and O(a) discretization effects are removed by discretizing the valence quarks with a suitable Osterwalder-Seiler variant of the Twisted Mass action. Operators are renormalized non-perturbatively in the RI/MOM scheme. Our preliminary result for BK(RGI) is 0.73(3)(3).Comment: 7 pages, 3 figures, 1 table, proceedings of the XXVII Int'l Symposyum on Lattice Field Theory (LAT2009), July 26-31 2009, Peking University, Beijing (China

The Receptor-Like Kinase SERK3/BAK1 Is Required for Basal Resistance against the Late Blight Pathogen Phytophthora infestans in Nicotiana benthamiana

BACKGROUND The filamentous oomycete plant pathogen Phytophthora infestans causes late blight, an economically important disease, on members of the nightshade family (Solanaceae), such as the crop plants potato and tomato. The related plant Nicotiana benthamiana is a model system to study plant-pathogen interactions, and the susceptibility of N. benthamiana to Phytophthora species varies from susceptible to resistant. Little is known about the extent to which plant basal immunity, mediated by membrane receptors that recognise conserved pathogen-associated molecular patterns (PAMPs), contributes to P. infestans resistance. PRINCIPAL FINDINGS We found that different species of Phytophthora have varying degrees of virulence on N. benthamiana ranging from avirulence (incompatible interaction) to moderate virulence through to full aggressiveness. The leucine-rich repeat receptor-like kinase (LRR-RLK) BAK1/SERK3 is a major modulator of PAMP-triggered immunity (PTI) in Arabidopsis thaliana and N. benthamiana. We cloned two NbSerk3 homologs, NbSerk3A and NbSerk3B, from N. benthamiana based on sequence similarity to the A. thaliana gene. N. benthamiana plants silenced for NbSerk3 showed markedly enhanced susceptibility to P. infestans infection but were not altered in resistance to Phytophthora mirabilis, a sister species of P. infestans that specializes on a different host plant. Furthermore, silencing of NbSerk3 reduced the cell death response triggered by the INF1, a secreted P. infestans protein with features of PAMPs. CONCLUSIONS/SIGNIFICANCE We demonstrated that N. benthamiana NbSERK3 significantly contributes to resistance to P. infestans and regulates the immune responses triggered by the P. infestans PAMP protein INF1. In the future, the identification of novel surface receptors that associate with NbSERK3A and/or NbSERK3B should lead to the identification of new receptors that mediate recognition of oomycete PAMPs, such as INF1.This work was supported by the Gatsby Charitable Foundation, BBSRC, Nuffield Foundation and the German Research Foundation (DFG). SS was supported by a personal research fellowship (SCHO1347/1-1). JPR is an Australian Research Council Future Fellow (FT0992129). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript