Isotopic signature and impact of car catalysts on the anthropogenic osmium budget

Higher osmium concentrations and lower 187Os/188Os ratios in sediments from urban areas have been linked to anthropogenic osmium sources. Automobile catalytic converters that use platinum group metals (PGM) are a potential source for this Os pollution. We present the first direct Os concentrations and isotopic measurements of catalytic converters for major automobile brands to test the assumption that car catalysts release Os with a distinct signature in the environment. The analysis of four new catalytic converters yields similar low 187Os/188Os ratios (0.1-0.2), suggesting a similar source for the PGM. The Os concentrations measured are in the ppt range (6-228 ppt). From our results, the osmium contribution of the car catalysts to the environment through attrition (wearing and grinding down of the catalyst by friction) is predicted to be low, <0.2 pg Os/m2/year in highly urbanized environment. We show that Os loss from catalysts as volatile OsO4 is important at car catalyst operating temperatures. Moreover, we estimate that car catalysts may be responsible for up to approximately 120 pg Os/m2 deposited per year in urban areas and that part of it may be exported to sedimentary sinks. Car catalytic converters are thus an important anthropogenic osmium source in densely populated areas. The NIST car catalyst standard (SRM-2557, made from recycled used catalysts) yields higher concentrations (up to 721 ppt Os) and a more radiogenic isotopic composition (approximately 0.38), perhaps indicative of Os contamination during its preparation.     

Modelling of isothermal austenite grain growth in a Si‐Mn TRIP steel ‐ experimental and calculation

Using the theory described in the preliminary publication, the isothermal grain growth of a low carbon, silicon‐manganese bearing TRIP‐steel has been studied. The austenitic grain size was established through the measurement of the mean linear intercept distance, which has been transformed into the real mean austenite grain size. A general model of the form dⁿ=d₀ⁿ+K₁t exp(K₂/T) was used and the coefficients n, K₁ and K₂ have been statistically determined. It has been demonstrated that for low annealing temperatures the value of n is situated around 6, whereas at high temperatures n rapidly drops and adopts a value of 2. This behaviour was related to the dissolution of the precipitates present in the austenitic matrix during the soaking treatments. The model delivers very good predictions for soaking temperatures up to 1200 °C. For higher temperatures, the deviations between the predicted grain size and the really measured one are higher.     

Optimal utilisation level for lean product development in a multitasking context

Flow of information is of utmost importance during product development (PD) endeavours with timely feedback supporting the resolution of higher risk elements. PD task size, multitasking and resource utilisation levels of the PD system influence information flow and the value ultimately realised from the investment in PD. In this paper, a model incorporating a methodology developed using queuing theory, and in particular, results obtained for Jackson networks are extended to help engineering management to improve PD task flow and consequently become more ‘lean’. Considered factors include: optimal PD task size and multitasking (focus) level as well as the utilisation level of PD resources. Empirical data were collected from a case study company and compared to optimal values. The benefits of the proposed model and approaches are discussed.     

Prédiction de l'intention créatrice à l'aide du modèle du comportement plainifié d'Ajzen.

Employed I. Ajzen's (1988) planned behavior model to predict creative intent. 291 undergraduates filled out questionnaires regarding 3 prototypical creative behaviors: writing and directing a play, building furniture from waste materials, and developing an individual style of interpreting music. Intent, attitude, subjective standards, and perception of control were measured for each behavior. Hierarchical multiple regression analysis result show that all of the predictor variables, except attitude toward theater behavior, contributed significantly to the prediction of intent. In considering basic impacts, perception of control plays the most significant role of prediction of intent. Perception of control also interacts either with standards or with attitude to increase explained variance of intent by 1–3%. Results support the relevance of the planned behavior model in the prediction of intent to endorse prototypical creative behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attribution et vécu émotionnel post-divorce.

Examined the relationship between postdivorce adjustment, attachment to ex-partner, and attributions for marriage failure using 97 female and 30 male divorced or separated Ss. Questionnaire data revealed that Ss who attributed marriage breakup to themselves were significantly more attached to their ex-partners and less adjusted than Ss who attributed their breakup to their ex-partners or to interactional factors. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social networks and aggressive behavior: Peer support or peer rejection?

Studied social networks and aggressive behavior in school in 2 cohorts of boys and girls in the 4th and 7th grades (N?=?695). Measures of social networks yielded convergent findings. Highly aggressive subjects (both boys and girls) did not differ from matched control subjects in terms of social cluster membership or in being isolated or rejected within the social network. Peer cluster analysis and reciprocal "best friend" selections indicated that aggressive subjects tended to affiliate with aggressive peers. Even though highly aggressive children and adolescents were less popular than control subjects in the social network at large, they were equally often identified as being nuclear members of social clusters. Aggressive subjects did not differ from matched control subjects in the number of times they were named by peers as "best friend," nor did the two groups differ in the probability of having friendship choices reciprocated by peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NK cells can recognize different forms of class I MHC

NK recognition and lysis of targets are mediated by activation receptor(s) whose effects may be over-ridden by inhibitory receptors recognizing class I MHC on the target. Incubation of normal lymphoblasts with a peptide that can bind to their class I MHC renders them sensitive to lysis by syngeneic NK cells. By binding to class I MHC, the peptide alters or masks the target structure recognized by an inhibitory NK receptor(s). This target structure is most likely an "empty" dimer of class I heavy chain and beta2m as opposed to a "full" class I trimer formed by binding of specific peptide that is recognized by CTL.     

Les valeurs de travail et le style de gestion du personnel.

Investigated the relationship between certain aspects of a superior's personality and his or her behavioral style with regard to personnel management, using 86 female employees without any managerial responsibility. Results show that work values were related to the personnel management style Ss would have advocated if they had been in a management position. While the relationships were not very strong, it is suggested that a single personality aspect (work values) may explain up to 27% of the variance. It is argued that it is essential for researchers to consider the various aspects of the superior input microsystem (experience, personality, skills) concurrently with the other subordinate and situation input microsystems. Results suggest the possibility of using work values to partially predict the eventual personnel management style of candidates for management jobs. It is contended that training should be based on and work to improve the cognitive interpretation of realities and should be concerned, if necessary, with changing basic attitudes. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

élaboration et validation du Questionnaire de Soutien Conjugal (QSC).

Although partner support represents a significant source of help amongst people (Beach, Fincham, Katz, & Bradbury, 1996; Cutrona, 1996), few valid and reliable measures of couple support are available. The current study presents the elaboration and validation of the “Questionnaire de soutien conjugal” (QSC), a brief measure evaluating given and received support within conjugal relationship. A sample of 270 French-Canadian couples completed the QSC and a short version of the Dyadic Adjustment Scale (Spanier, 1976; Sabourin, Valois, & Lussier, 2005). One year later, 160 couples agreed to complete the same measures again. Exploratory Factor Analyses supported the two-factor structure of the measure (provided support and received support); those factors predicted current and future couple satisfaction. QSC scales also showed good internal consistency as well as good test–retest reliability after a 1-year period. These findings reveal satisfactory psychometric properties and justify the QSC's use in clinical settings and research protocols. Strengths, limitations, and recommendations for futures research are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)