First-principles pseudopotential study of an aluminium grain boundary containing sulphur atoms

The electronic structure of an aluminium grain boundary with segregated sulphur impurity atoms has been calculated by a first-principles pseudo-potential method. It is found that a sulphur atom bonds to only one of the neighbouring aluminium atoms. This bond is a mixed-character metallic-covalent bond which is stronger than the metallic Al-Al bonds. Electrons that participate in forming this bond are 3p electrons of sulphur but not its 3s electrons. Other Al--S bonds in the boundary contain no covalent character. From the nature of Al--S bonds in the boundary it cannot be decided whether the embrittlement promotion mechanism by sulphur segregation should be classified as a 'bond mobility model' or a 'decohesion model'.     

Toward an understanding of aging in plutonium from direct measurements of stored energy

ABSTRACT

We present here the first direct measurement of the radiation-damage-induced energy stored in δ-phase plutonium. The primary mode of radioactive decay of ²³⁹Pu occurs with a time constant of τ=1.1?×?10¹²?s. Each decay imparts about 85?keV of recoil energy to the uranium byproduct, 5.2?Mev to the alpha particle, and a spectrum of mostly low energy gamma rays with the most probable at 51?keV [1]. Most of the decay energy is converted immediately to heat, releasing about 1.9?mW/g. However, some thermally-recoverable energy remains trapped. Reported here are measurements of that stored energy using differential scanning calorimetry (DSC) applied to ²³⁹Pu-2.0 at.%Ga δ-phase alloy. Retained energy of ～2 J/g saturates at about 5 months and is unchanged after 30 years. The magnitude of the stored energy agrees with a short-bond defect model that that we present here. This model treats radiation damage as a Pu impurity with shortened bond lengths. It explains the change in known properties with age and predicts that density increases with age, contrary to current thinking. The short-bond impurities proposed are expected to act like other impurities, affecting strength, phase transitions, grain boundaries and other metallurgical properties.     

Toxic Environment of war: Maternal prenatal heavy metal load predicts infant emotional development

BackgroundPeople in war zones are exposed to heavy metal contamination deriving from new-generation weapons, in addition to exposure to psychologically traumatizing war events. Pregnant women and their children-to-be are particularly vulnerable to both biological and psychological war effects.ObjectiveThe aim of the current study was to analyse the impact of maternal prenatal heavy metal contamination on infant emotional development and to examine the potential moderating role of maternal symptoms of post-traumatic stress disorder (PTSD) in the association between heavy metal load and infant emotional development.MethodsThe participants were 502 Palestinian mothers, pregnant in their first trimester during the 2014 War on Gaza. The mothers were recruited at their delivery (T1) and followed at the infants’ age of 6–7 months (T2; N = 392). The load of five weapon-related heavy metals (chromium, mercury, vanadium, strontium, and uranium) was analysed by Inductively Coupled Plasma Mass Spectrometry (ICP/MS) from mothers’ hair samples at childbirth (T1). Assessment of maternal PTSD symptoms was based on the Harvard Trauma Questionnaire (HTQ) and infant emotional development on the Infant Behavior Questionnaire (IBQ), both reported by mothers (T2).ResultsTwo of the analysed metals, chromium and uranium, adversely predicted children’s early emotional development, indicated by decreased positive affectivity, increased negative emotionality, and problems in early orientation and regulation. Mother’s PTSD did not moderate the impact of heavy metal contamination on children’s emotional development.ConclusionsAdverse impact of war is not limited to those who experience it directly, but is passed on to future generations through multiple mechanisms. International organizations are obliged to protect parents and infants from the modern weaponry in wars.     

Mechanical behaviour of an Al–matrix composite reinforced with nanocrystalline Al-coated B4C particulates

In metal–matrix composites (MMCs), interfacial bonding between the metal matrix and the ceramic reinforcement plays a crucial role in their mechanical performance. In the present study, B₄C particles were cryomilled with an Al alloy to produce a composite powder, in which the B₄C was uniformly distributed in nanocrystalline Al. The cryomilling developed a strong bond between the B₄C and the Al, allowing the nanocrystalline Al to act as a coating with a strong ceramic–metal interface. This cryomilled composite powder was then introduced, as a reinforcement, into a conventional Al alloy to strengthen the material. After consolidation, the result was a bulk Al–matrix composite reinforced with B₄C particles encapsulated in nanocrystalline Al. This composite exhibits greatly improved strength and stiffness.     

Boron impurities on a vicinal Si(100) surface: A study of structural properties and binding energies

The equilibrium locations of boron on the steps of the Si(100) surface have been studied using the Hartree-Fock method at the semiempirical level. The step is represented by a cluster of silicon atoms whose dangling bonds are saturated by hydrogen atoms. The boron impurity is moved in the step in substitutional and interstitial positions and the optimal configuration of the step containing the impurity is evaluated from a steepest-descent energy minimization. The study focuses on the dependence of the properties of the boron-step interaction on the shape of the step. These effects are analysed in the light of the features of boron absorbed on the flat surfaces and in the bulk, which have been widely studied.     

Structure of PbMnO2.75 determined by electron crystallography

The PbMnO_{3– x} system has a great number of phases with large unit cells for different values of x. In the present work, we study a PbMnO_2.75 phase that has proven too complex to be solved by X-ray powder diffraction. Using electron crystallography, we have determined the positions of all metal atoms without the necessity of using a model as a starting point. The results correspond, within experimental uncertainties, to those obtained by Bougerol et al. (J. Solid State Chem. 169 131 (2002)).     

Vocal mistuning reveals the origin of musical scales

ABSTRACT

Theories of the origin of tonality from the time of Pythagoras onward have assumed that the intervals used in musical scales are defined mathematically based on harmonic ratios. Virtually all such theories are predicated on tunable instruments (e.g. strings), whereas the voice is the most ancestral and universal instrument used to make music. In the present study, we analysed the tuning of sung musical intervals from a familiar song, doing so across both trained and untrained singers. Contrary to the predictions of traditional theories, we found that sung intervals (unlike those of instruments) showed marked overlap with neighbouring interval categories. Furthermore, we found that listeners of these sung productions did not base their aesthetic judgments of singing quality on the precision of tuning of sung intervals. We consolidate these results into a model of tonality based on both vocal and sensory factors that contribute to the formation of sung melodies.     

The contribution of role satisfaction,meaning in life and work–home conflict to explaining well-being among working grandparents

Background and objectives: The study aimed to examine the relationship of satisfaction with occupied roles as well as the sense of meaning in life and experience of work–home conflict to well-being among working grandparents in Israel.

Design and methods: The research sample consisted of 316 employed grandparents aged 50–80 (153 grandfathers and 163 grandmothers), who were employed in various types of organizations. Data were collected using structured questionnaires. Structural equation modeling was used for data analysis.

Results: The research findings indicate that the sense of meaning in life mediated the relationship between role satisfaction and the two types of work–home conflict. A significant relationship was found between “work interferes with family” conflict and negative affect. Higher personal resources were associated with higher meaning in life. Gender was not related to the experience of work–home conflict or to any of the outcome variables.

Conclusions: The centrality of meaning in life in the model that explains the experience of work–home conflict and its outcomes among working grandparents, derives from its mediating role in the relationship between the experience of role satisfaction and both types of role conflict, as well as from its direct impact on positive and negative affect.     

Determination of atomic structure of phason planes in the ξ′-Al–Pd–Mn phase

The atomic structures of specific types of linear defects (phason lines) and planar defects (phason planes) in the complex metallic alloy phase ξ′-Al–Pd–Mn have been determined by high-resolution electron microscopy (HREM) and theoretical HREM simulation. The results show that a representational atomic structural model for phason planes can be constructed by introducing a shift between two parts of the perfect crystalline structure using a translation vector of r ?=?(1/2) a ?+?(1/2τ) c . This typical phason plane is normally parallel to the (001) plane of the ξ′-Al–Pd–Mn phase and consists of phason lines, which are arranged side-by-side with their linear direction parallel to the [010] axis. HREM simulations, based on the structural model for both edge-on and inclined types of phason lines, agree well with the experimental results. Taking into account the fact that the structural difference between various curved phason planes arises from the variation in the arrangement of individual phason lines, the atomic structures of the edge-on and inclined phason lines can be used to explain the various curved phason planes frequently observed in the ξ′-Al–Pd–Mn phase.     

Attachments,gender, and delinquency

The purpose of this study is to contribute to a gender‐integrated theory of delinquent behavior by testing the assumptions of gender specialized delinquent behavior and of sex typed bonds as inhibitors of deviance. Data from self‐administered questionnaires completed by a sample of teenagers in the 10th grade and one year later were used in the study. We found no clear evidence of gender specialization in the deviant behavior reported by the youth. Furthermore, the analysis did not lend support to traditional theories that link male and female delinquency to the weakening of different bonds. The testing of an inclusive model of bond theories produced very similar results for both genders.     

Age of initiation with different substances and relationships with resources and vulnerabilities: A cross-national study

Abstract

Although the topic of forgiveness has been studied extensively among adults, little is known about the factors that are associated with children’s forgiveness. The current research addressed the question whether a child’s social status in the classroom is related to the tendency to forgive offending peers. We particularly focused on two types of status: preference and popularity. We ran one study with two samples among 9–13 year-old children (n = 577) who completed a sociometric instrument and a self-reported forgiveness measure. We found some initial support that preference, but not popularity, is positively associated with forgiveness, even after accounting for transgression-specific characteristics, such as friendship bond with the offender and perceived offense severity. We discuss the theoretical implications among these findings for both understanding children’s forgiveness, and the differential role of preference and popularity as social status indicators.     

Évaluation de l’orthographe des élèves dysphasiques en situation de narration communicative : variations selon le type d’orthographe,lexicale versus morphologique

IntroductionThe overall goal of the study was to draw, in French language, a complete picture of spelling abilities in young students with SLI, enrolling in ordinary classes.ObjectiveThe main aim was to show how the developmental trajectories of lexical spelling and the morphological spelling are different when a large age span is observed (7 to 18 years old).MethodsThe spelling abilities were evaluated through a narrative communicative. Two groups of students with SLI (7–11 years and 12–18 years) were compared with two groups of typical students matched on chronological age.ResultsThe lexical spelling was acquired before the morphological spelling for SLI and typical participants. At 12–18 of age, the SLI participants did not produce more lexical errors than the typical group. For the lexical spelling, at 7–11 years, the SLI participants had a specific difficulty with the segmentation of the words: they produced words that do not exist in the language and which by definition have no morphological markers.ConclusionThe SLI participants need more time to learn than the typical participants. At 7–11 years, before learning of morphology, they must be able to control segmentation the segmentation of words. The low number of morphological errors in the school SLI group of 7–11 years is not necessarily a sign of difficulty. The increase in the number of errors at 12–18 years is the sign that this problem has been exceeded and that the learning of the written morphological markers can really begin.     

A novel method for constructing the mean field of grain-orientation-dependent residual stress

The heterogeneity of grain-orientation-dependent residual stress (ODRS) in polycrystalline materials has received a great deal of attention in the past few years. This letter describes a novel method, called the spherical harmonics approach (SHA), for analysing ODRS. The stress orientation distribution function (SODF) is defined to describe quantitatively the mean field of the residual stress as a function of grain orientation in the Euler space. This stress field can be expanded in terms of generalized spherical harmonics, and its series coefficients can be determined directly from lattice strain maps (strain pole figures). While solving the deconvolution problem of this stress field, the stress or strain equilibrium between neighbouring grains is considered simultaneously by implementing a self-consistent model in the iterative algorithm. The application of the SHA is illustrated by the construction of the SODF for a cold-rolled and annealed austenite stainless steel, using strain pole figures obtained by neutron diffraction.     

No expectation bias in elite-level cricket umpires’ leg-before-wicket (LBW) decisions according to batting order position

ObjectivesPrevious studies have shown that sport officials’ decisions can be impacted by biases associated with expectations. The aim of this study was to determine whether elite cricket umpires’ decisions are also influenced by expectations associated with batter skill.MethodsLBW decisions (n = 5578) from actual elite level cricket matches in Australia between 2009 and 2016 were analysed in a multi-level binomial logistic regression paradigm. In our first model, we predicted the likelihood that an umpire will answer ‘out’ for batters in the top order (1–4), middle order (5–7), and low order (8-11). In our second model, we controlled for the correctness of a decision.ResultsUmpires were more likely to respond ‘out’ as the batting order progressed, however this did not appear to be due to biased decision-making. Instead, as batting order progressed, batters were more likely to actually be ‘out’.ConclusionsCricket umpires do not seem to be impacted by expectation bias associated with batting order. This study highlights the importance of controlling for the correctness of a decision when exploring bias in sport officials’ decisions.     

Emotion Regulation Questionnaire for use with athletes

ObjectivesThree studies examine the factorial validity, internal consistency, test–retest stability, and criterion validity of the Emotion Regulation Questionnaire (ERQ: Gross & John, 2003) for use with athletes.DesignFactorial validity, internal consistency, test–retest stability and criterion validity of the ERQ were examined over three stages, using three separate samples.MethodIn stage 1 the factorial validity and internal consistency of the ERQ subscales were examined based on responses from 433 sport participants. In stage 2, 176 sport participants completed the ERQ on two occasions separated by an interval of two weeks. In stage 3, the criterion validity of the ERQ was examined. Sport participants (n = 88) completed the ERQ and reported the intensity, frequency and direction of a range of emotions experienced when competing in sport.ResultsConfirmatory factor analysis results lend some support to a two-factor model when reappraisal and suppression are allowed to correlate. Alpha coefficients were acceptable. Test–retest stability analyses indicated poor agreement and a greater influence of situational, as opposed to trait factors, in the variance of item scores on the second test administration. In addition, results were partially consistent with findings of Gross and John (2003): reappraisal scores were associated with pleasant emotions, but suppression scores were not associated with unpleasant emotions.ConclusionResults provide mixed support for the validity of the ERQ in sport. Because the ERQ is intended to assess stable patterns of emotion regulation, the instability of items is a concern and reasons for this require further investigation.     

Psychosocial mediators of a lifestyle physical activity intervention in women

ObjectivesA lifestyle physical activity intervention in women based on the transtheoretical model and social–cognitive theory effectively increased physical activity. The aim of the present study was to examine possible mediators (perceived benefits and barriers of physical activity, self-efficacy, processes of change, and social support) of these physical activity changes.MethodsMembers of four units of a women's organization followed a six-month minimal-contact physical activity program. The intervention program included one group meeting, a self-help booklet and five monthly reminder letters. Members of two other units served as control group. Physical activity (accelerometer counts), and psychosocial constructs (self-report questionnaires) were assessed at baseline (pretest) and directly after the intervention (posttest). Women who completed all measurements (n = 101) were included in the mediation analyses.ResultsParticipants in the intervention group reported significantly greater increases in the use of behavioral processes from pretest to posttest than participants in the control group. None of the proposed psychosocial constructs showed a mediating effect on changes in physical activity.ConclusionsThe mechanisms proposed by the transtheoretical model and social–cognitive theory could not explain the positive effect of the intervention on physical activity. Identifying the working components of an intervention remains a challenging and necessary step in the development of effective low-cost and high-reach physical activity interventions.     

The role of emotion in bridging the intention–behaviour gap: The case of sports participation

ProblemPsychological models of sports participation frequently draw on the Theory of Planned Behaviour (TPB) in order to predict health-behaviour-related intentions. While these models commonly show high predictive power with respect to intention, they often fall short in the prediction of behaviour (the ‘intention–behaviour gap’). The present study contends that integrating emotional processes into TPB can substantially improve the model's predictive power over and above traditional cognitive predictors.MethodIn a longitudinal study structural equation modelling was employed to test a traditional model (based on TPB) and an extended model including emotion associated with the intention to exercise as a mediator variable. A community sample (N = 237) completed a questionnaire measuring the components of a traditional TPB model. Prior to each of 16 expected exercise sessions (over 8 weeks) intention to exercise and emotion associated with the intention were measured.ResultsResults confirmed a substantial increase of 17% in explained variance of exercise frequency and 20% in exercise duration for the extended model. Emotional appraisal of the intention to exercise thus appears to mediate the traditional intention–behaviour relationship, suggesting that emotionally based interventions aimed at increasing sports participation may be helpful.ConclusionIt is concluded that emotion variables should be added to traditional TPB models in order to predict health behaviour more fully.     

Interrole conflict and self-efficacy to manage work and family demands mediate the relationships of job and family demands with stress in the job and family domains

Background and objectives: This study derives from Work–Home Resources model (ten Brummelhuis, L. L., & Bakker, A. B. (2012). A resource perspective on the work–home interface: The work–home resources model. American Psychologist, 67(7), 545–556. doi:10.1037/a0027974) and Social Cognitive Theory (Bandura, A. (1986). Social foundations of thought and action: A social cognitive theory. Englewood Cliffs, NJ, US: Prentice-Hall, Inc.) to investigate mechanisms responsible for the effect of job and family demands on work- and family-related perceived stress. We hypothesized that interrole conflict and self-efficacy to manage work and family demands operate either independently or sequentially transmitting the effects of demands on perceived stress. Design: A sample of 100 employees of various occupations participated in the study conducted online in two waves: Time 1 (T1) and Time 2 (T2) with a three-month interval. Method: Regression analysis with bootstrapping was applied. Results: Interrole conflict (T1) did not mediate the relationships between demands (T1) and perceived stress (T2), whereas self-efficacy (T1) mediated only those between family demands (T1) and stress (T2). However, data supported the sequential mediation hypotheses: Demands (T1) were associated with increased interrole conflict (T1) which in turn decreased self-efficacy (T1) and ultimately resulted in the elevated perceived stress at work and in the family (T2). Conclusions: Demands originating in one domain can impact stress both in the same and other life areas through the sequence of interrole conflict and context-specific self-efficacy.     

Does Bullying Affect Work-to-Private-Life Interference? Testing the Mediating Role of Resilience

Objectives. The present study, using the conservation of resources theory as a theoretical framework, aims to establish whether work-related bullying is associated with the development of two different types of work-to-private-life interference, i.e., time based and strain based. The study also aims to test whether these relationships are mediated by resilience. Method. In total, 333 nurses filled out a self-report questionnaire. Data analyses were performed by using structural equation model. Results. Results confirmed the hypothesized model: work-related bullying is associated with both strain-based and time-based work-to-private-life interferences. The bootstrap test indicated the presence of an indirect effect of bullying on both types of work-to-private-life interference via resilience. Originality/Value. The present study contributes to improve the understanding on the mechanisms linking work-related bullying and worker well-being, by providing evidence for the mediating role of resilience between bullying and both time-based and strain-based work–life interferences. Practical implications. The present study suggests that the intervention programs, in order to be effectiveness in sustaining work–life balance among nurses, should take into great account the social climate in the organizational context, e.g., the quality of the social climate with particular reference to the bullying prevention.     

Perfectionistic concerns predict increases in adolescents’ anxiety symptoms: a three-wave longitudinal study

Background and Objectives: Although perfectionism has been proposed to be a risk factor for the development of anxiety, research on perfectionism and anxiety symptoms in adolescents is scarce and inconclusive. The aim of the present study was to investigate whether the two higher-order dimensions of perfectionism – perfectionistic strivings and perfectionistic concerns – predict the development and maintenance of anxiety symptoms. An additional aim of the present study was to examine potential reciprocal effects of anxiety symptoms predicting increases in perfectionism.

Design: The study used a longitudinal design with three waves spaced 4–5 months apart.

Methods: A non-clinical sample of 489 adolescents aged 12–19 years completed a paper-and-pencil questionnaire.

Results: As expected, results showed a positive effect from perfectionistic concerns to anxiety symptoms, but the effect was restricted to middle-to-late adolescents (16–19 years old): Perfectionistic concerns predicted longitudinal increases in adolescents’ anxiety symptoms, whereas perfectionistic strivings did not. Furthermore, anxiety symptoms did not predict increases in perfectionism.

Conclusions: Implications for the understanding of the relationship between perfectionism and anxiety symptoms are discussed.