Corrosion protection of AA2024 sealed anodic layers using the hydrophobic properties of carboxylic acids

The present study investigates the use of carboxylic acids as a post-treatment for sealed AA2024 anodised in tartaric–sulphuric acid electrolyte. Four monocarboxylic acids with different carbon chain lengths were tested ((CH3–(CH2)n–COOH with n=4, 8, 12 and 16). Hydrophobic surface properties after the posttreatment were characterized by contact angle measurements. Electrochemical impedance spectroscopy (EIS) was performed to assess the ability of the four carboxylic acids to form protective films. It was shown that stearic acid (n=16) used in its pure molten state was the most efficient. The organic film formed very rapidly (under 5 min) and contributed to the enhancement of the protection in terms of corrosion resistance of the sealed anodic layers. EIS measurements showed the presence of the organic films on the specimen surface

FESEM and EIS Study of Sealed AA2024 T3 Anodized in Sulfuric Acid Electrolytes: Influence of Tartaric Acid

The present study investigates the effect of tartaric acid on anodic film morphology and on corrosion resistance of hydrothermally sealed anodized AA2024. Anodizing treatment was performed in dilute sulfuric acid electrolyte with or without addition of tartaric acid. Hydrothermal sealing was carried out in boiling water for each anodized specimen. The morphology of the sealed anodic films was examined using field-emission scanning electron microscopy (FESEM). Electrochemical impedance spectroscopy (EIS) was performed to assess sealing quality and corrosion resistance of the anodic films. It was shown that the sealing was more efficient in the case of anodic films formed in tartaric acid electrolyte mainly due to their lower porosity. It was also observed that the properties of the barrier layer were higher when sealing was performed on specimens anodized in the presence of tartaric acid. This suggests a specific role of the species on the barrier layer, which contributes to the enhancement of the performance in terms of corrosion resistance of the sealed anodic films. The present study clearly validates the beneficial role of tartaric acid in anodizing baths for the corrosion protection of AA2024

An examination of the construct validity of the Generalized Pliance Questionnaire

The Generalized Pliance Questionnaire (GPQ) was originally validated against measures of psychological flexibility and psychological distress. However, measures which have substantial conceptual overlap with the GPQ (e.g., the Need to Belong Scale [NTBS], Brief Fear of Negative Evaluation Scale [BFNE]) were not examined. The present study seeks to investigate the construct validity of the GPQ-9. As expected, data from a survey of 272 participants indicated significant large correlations between the GPQ-9 and NTBS and BFNE respectively. The results of a confirmatory factor analysis confirmed the unidimensional structure of the GPQ-9. A structural equation model revealed that the BFNE (and not the GPQ-9 or NTBS) was significantly associated with psychological flexibility and psychological distress. Implications of these tentative preliminary findings suggest that the GPQ may be a more sensitive measure than the BFNE for ACT research

Prevention of post-mastectomy neuropathic pain with memantine: study protocol for a randomized controlled trial

International audienceBackground: N-methyl-D-aspartate receptor antagonists are potential therapies for neuropathic pain, and memantine has a good tolerance profile. A preclinical study recently reported that presurgery memantine may prevent neuropathic pain development and cognition dysfunction. Considering the high prevalence of breast cancer and of post-mastectomy neuropathic pain, a clinical trial is carried out to evaluate if memantine may prevent neuropathic pain development and maintain cognitive function and quality of life in cancer patients. Methods/Design: A randomized clinical trial (NCT01536314) includes 40 women with breast cancer undergoing mastectomy at the Oncology Hospital, Clermont-Ferrand, France. Memantine (5 to 20 mg/day; n = 20) or placebo (n = 20) is administered for 4 weeks starting 2 weeks before surgery. Intensity of pain, cognitive function, quality of life and of sleep, anxiety and depression are evaluated with questionnaires. The primary endpoint is pain intensity on a 0 to 10) numerical scale at 3 months post-mastectomy. Data analysis is performed using mixed models and the tests are two-sided, with a type I error set at α = 0.05. Discussion: The hypothesis of this translational approach is to confirm in patients the beneficial prophylactic effect of memantine observed in animals. Such a protective action of memantine against neuropathic pain and cognitive dysfunction would greatly improve the quality of life of cancer patients. Trial registration: ClinicalTrials.gov: NCT01536314 on 16 February 201

Examining the utility of functional process models of distress tolerance in predicting psychopathology

Background: Distress tolerance is targeted as both a predictor and mechanism of psychopathology development and maintenance, treatment engagement and response, and relapse of psychological symptoms and problem behaviors. Empirical inconsistencies limit the utility of this construct, however, and distress tolerance has not been well investigated in nonclinical samples or in prospective study designs, making it difficult to determine its course of influence on psychopathology and to distinguish it from other psychological processes.Aims and Methods: The current study examined the operating characteristics of multi-method distress tolerance measures in the context of theoretically important psychological processes (i.e., experiential acceptance and mindfulness) in a nonclinical sample (N = 240) of 18-20 year old college students, a population at risk for emerging psychopathology. The unique and shared contributions of these variables were examined in multiple regression analyses at index assessment and in regression-based path analyses of models predicting changes in psychological functioning over one year. Results: No significant correlations were observed among the Distress Tolerance Scale, the PASAT, and the Breath Holding Task. Concurrent and future psychopathology in five domains was better predicted by models that included acceptance and mindfulness processes. All main effects of distress tolerance predicting psychopathology were moderated and/or mediated by acceptance and mindfulness. In every case, greater distress tolerance predicted both healthy and harmful psychological outcomes depending on its relationship to one or more acceptance and mindfulness process. Conclusions: As proposed, the conditional and indirect effects of acceptance and mindfulness often clarified seemingly incoherent main effects on psychopathology and often transformed distress tolerance into a significant predictor when main effects were absent. These results indicate that inconsistencies in the distress tolerance literature may be resolved by taking a functional contextual approach to conceptualizing and assessing the construct. However, it is not known whether distress tolerance measures improve the clinical utility of acceptance and mindfulness measures, which were independently strong predictors of psychological functioning in the present study. Further investigation of functional process models may increase the clinical utility and empirical progress of the distress tolerance construct

Correlates of Depression in First-Year College Students

This study aimed to identify and rank the personal, family-related, social, and academic correlates of depressive symptoms in first-year college students. A questionnaire that included the Beck Depression Inventory-II (BDI-II) was administered to 389 first-year college students (mean age = 18.9; SD = 3.38; 59.4% female). Eight variables contributed uniquely to the variance of depressive symptoms and were, in decreasing order of importance: (1) the absence of personal goals, (2) a high level of anxiety and (3) of dysfunctional thoughts regarding success, (4) a lack of emotional adjustment to college, (5) being female, (6) receiving little warmth and encouragement of autonomy from one’s mother and (7) from one’s father, and (8) being attracted to members of the opposite or both sexes. These results suggest that a multimodal intervention is required to support students’ mental health.  Cette étude visait à identifier et à hiérarchiser les corrélats personnels, familiaux, sociaux et académiques des symptômes de dépression chez des élèves en première année d’études collégiales. Ainsi, 389 étudiants inscrits en première année d’études collégiales (âge moyen : 18,9 ans; écart-type : 3,38 ans; 59,4 % de jeunes femmes) ont rempli un questionnaire comprenant l’Inventaire de dépression de BeckII. Huit facteurs ont contribué de façon unique à la variance des symptômes de dépression et sont, par ordre décroissant d’importance : (1) l’absence d’objectifs personnels, (2) un niveau d’anxiété élevé, (3) des pensées dysfonctionnelles à propos de la réussite, (4) un faible niveau d’adaptation émotionnelle au Cégep, (5) le fait d’être une femme, (6) le fait de recevoir peu d’affection et d’encouragement vers l’autonomie de la part de sa mère et (7) de son père, et (8) le fait être attiré par des personnes du sexe opposé ou des deux sexes. Ces résultats semblent indiquer qu’une intervention multimodale est requise pour soutenir la santé mentale des élèves

Deuteron and antideuteron production in Au+Au collisions at sqrt(s_NN)=200 GeV

The production of deuterons and antideuterons in the transverse momentum range 1.1 < p_T < 4.3 GeV/c at mid-rapidity in Au + Au collisions at sqrt(s_NN)=200 GeV has been studied by the PHENIX experiment at RHIC. A coalescence analysis comparing the deuteron and antideuteron spectra with those of protons and antiprotons, has been performed. The coalescence probability is equal for both deuterons and antideuterons and increases as a function of p_T, which is consistent with an expanding collision zone. Comparing (anti)proton yields p_bar/p = 0.73 +/- 0.01, with (anti)deuteron yields: d_bar/d = 0.47 +/- 0.03, we estimate that n_bar/n = 0.64 +/- 0.04.Comment: 326 authors, 6 pages text, 5 figures, 1 Table. Submitted to PRL. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Single Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV

The invariant differential cross section for inclusive electron production in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range $0.4 <= p_T <= 5.0 GeV/c at midrapidity (eta <= 0.35). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e. charm quarks or, at high p_T, bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined as sigma_(c c^bar) = 0.92 +/- 0.15 (stat.) +- 0.54 (sys.) mb.Comment: 329 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Suppressed pi^0 Production at Large Transverse Momentum in Central Au+Au Collisions at sqrt(s_NN) = 200 GeV

Transverse momentum spectra of neutral pions in the range 1 < p_T < 10 GeV/c have been measured at mid-rapidity by the PHENIX experiment at RHIC in Au+Au collisions at sqrt(s_NN) = 200 GeV. The pi^0 multiplicity in central reactions is significantly below the yields measured at the same sqrt(s_NN) in peripheral Au+Au and p+p reactions scaled by the number of nucleon-nucleon collisions. For the most central bin, the suppression factor is ~2.5 at p_T = 2 GeV/c and increases to ~4-5 at p_T ~= 4 GeV/c. At larger p_T, the suppression remains constant within errors. The deficit is already apparent in semi-peripheral reactions and increases smoothly with centrality.Comment: 326 authors, 6 pages text, RevTeX, 3 figures, 2 tables. Submitted to PRL. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

High transverse momentum eta meson production in p+p, d+Au and Au+Au collisions at sqrt(s_NN) = 200 GeV

Inclusive transverse momentum spectra of eta mesons in the range p_T~2-12 GeV/c have been measured at mid-rapidity (|\eta| < 0,35) by the PHENIX experiment at RHIC in p+p, d+Au and Au+Au collisions at sqrt(s_NN) = 200 GeV. The eta mesons are reconstructed through their eta--> \gamma\gamma channel for the three colliding systems as well as through the eta-->pi^0 pi+ pi- decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R_dAu(p_T~1.0-1.1, suggests at most only modest p_T broadening ("Cronin enhancement"). In central Au+Au reactions, the eta yields are significantly suppressed, with R_AuAu(pT)~0.2. The ratio of eta to pi^0 yields is approximately constant as a function of p_T for the three colliding systems in agreement with the high-p_T world average of R_eta/pi^0 \approx 0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies [sqrt(s_NN)~3-1800 GeV] as well as, for high scaled momentum x_p, in e+e- annihilations at sqrt(s)=91.2 GeV. These results are consistent with a scenario where high-p_T eta production in nuclear collisions at RHIC is largely unaffected by initial-state effects, but where light-quark mesons (pi^0;eta) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.Comment: 391 authors, NN pages text, RevTeX4, figures, tables. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm