Structure images of unaged martensite containing a high carbon content

Abstract

A highly tetragonal (large c/a ratio) martensite in a Fe-4 wt% Al-1·6 wt% Mn-2 wt% Calloy, which is not aged and considered to be as ‘fresh’ as possible, has been observed by high-resolution electron microscope. From the arrangement of atom rows in the [010] structure image and the corresponding electron diffraction pattern, it is concluded that carbon atoms are clustered on the (305) plane. The unit structure of these carbon-clustered regions is similar to that of the modulated structure observed in Fe-C alloys, although a periodic layer distribution of carbon atoms is not observed.     

Quasi-two-dimensional or hcp palladium nanoparticles with host-guest interaction prepared at room temperature

Quasi-two-dimensional palladium nanoparticles with an average lateral dimension of 7 nm have been prepared by reduction of a PdCl₂ graphite intercalation compound precursor by lithium-diphenylide in tetrahydrofuran at room temperature. Selected-area electron diffraction patterns provide evidence that the palladium nanoparticles are hcp single-crystal particles. Owing to the template effect of the graphite lattice, the lattice parameter of palladium was found to have a strong relation with the graphite, and a 3a _graphite superstructure was inferred. The palladium structure is rotated by 30^o with regard to the carbon host lattice. Raman spectroscopy on this sample showed that a charge transfer between carbon and palladium occurs. The sample can be considered as a common Pd-graphite intercalation compound with palladium nanoparticles as guest. This behaviour is different from palladium nanoparticles prepared by hydrogen reduction at higher temperatures from the same precursor material. These particles may represent an early stage of nanoparticle formation.     

EELS analysis of vacuum arc-deposited diamond-like films

Abstract

Electron energy-loss spectroscopy measurements have been made on amorphous diamond-like carbon films produced by condensing the plasma stream from a filtered vacuum arc. The results are compared with spectra from diamond, graphitized carbon and amorphous carbon. Although the energy-loss spectra reveal the presence of a small quantity of sp²-bonded material in the diamond-like film, the high plasmon frequency and shape of the K-edge show that the material is essentially an amorphous form of diamond. The fraction of sp²- bonded carbon was quantified and found to be of the order of 15%. It was not possible to determine if the sp² carbon was on the surface or throughout the bulk.     

Intention to change activities that reduce carbon dioxide emissions related to worry about global climate change consequences

IntroductionMitigating the global climate change requires actions at different levels including that lay people change their consumption patterns, which cause emissions of greenhouse gases. Recent research suggests that inducing affects such as fear and worry may have positive effects.ObjectiveTo investigate whether worry in addition to personalized information about emissions of carbon dioxide would influence lay people's intentions to change consumption-related personal activities causing carbon-dioxide emissions.MethodA municipality-provided tool to calculate their annual carbon dioxide emissions was used by 135 university students who after being informed about negative consequences of global climate change stated their intentions to change a number of personal activities to reduce carbon dioxide emissions during the following 12 months. They also rated how worried they were about eight global climate change consequences.ResultsIntentions to change travel, energy use at home, food consumption, involvement in environmental organizations, and support of environmental policies increased with worry. An interaction was also observed such that high-emitters’ intentions to invest in energy-efficient infrastructure increased more with worry than did low- and medium-emitters’ intentions.ConclusionsIn line with recent research positing that affect increases preventive actions, the hypothesis was supported that intentions to change personal activities to reduce carbon dioxide emissions increased with participants’ worry about the consequences of global climate change.     

Atomic and electronic structure of a carbon nitride compound prepared by magnetron sputtering

The atomic structure, chemical composition and chemical bonding state of a carbon nitride compound, synthesized by rf magnetron sputtering, have been studied by high-resolution electron microscopy, nanobeam diffraction and electron energy loss spectroscopy. It is revealed that the grain sizes of a crystalline compound in an amorphous matrix lie in the range 5-10 nm, and that the compound has a hexagonal structure with a = 0.324 nm and c = 0.404 nm. The C and N K edges are observed in the high-energy region of the electron-energy-loss spectrum. Only features corresponding to C sigma* bonds are found in the C K edge spectrum, which provides evidence for sp³ hybridization of C orbitals in the compound. Quantifying the electron-energy-loss spectra suggests that the compound is C₇N₁₀.     

Fourier transform infrared and Raman spectroscopy studies on a - and ß-C3N4 films

Crystalline carbon nitride films have been synthesized on Si(100) substrates by the microwave plasma chemical vapour deposition technique. In order to understand their structure, Raman and Fourier transform infrared spectra of aand b-C3N4 were calculated using a scale factor and the observed Raman and infrared spectra of a- and b-Si N . A scale factor (1.47) for the stretching 3 4 frequencies from the tetrahedral C-N to Si-N bonds was calculated through Hooke's law. Experimental Raman and infrared spectra conform to the calculated results: so we conclude that the film contain a-C3N4 and b-C3N4     

Transmission electron microscopy characterization of the high-Tc superconductor HgBa2Ca3Cu4O 10+ delta

The structures of HgBa3Ca4Cu4O10+ delta(Hg-1234) samples have been characterized by means of high-resolution electron microscopy, electron diffraction, X-ray energy-dispersive spectroscopy (XEDS) and electron-energy-loss spectroscopy (EELS) techniques. A modulated structure with a modulation vector of q = (0.036-0.048) b* + 0.5c* was found for Hg-1234. High-resolution electron microscopy on the modulated structure revealed slight displacements of atomic layers along the c direction. The anomalous contrast induced by the modulation was observed to be distributed asymmetrically between the HgOdelta layers, leading to the breakdown of the (001) mirror symmetry of the basic structure. XEDS compositional analyses showed a depletion of mercury for the modulated Hg1234 compared with the unmodulated Hg-1234, while EELS analysis suggested the presence of carbon in the modulated Hg-1234 phase. In addition, a sidecentred ordered (Cu, Hg)-1223 phase with low mercury content was identified as one of the major impurity phases in the Hg-1234 samples.     

The structure of DSM-5 posttraumatic stress disorder symptoms in war veterans

Background and Objectives: The present research examined the underlying factor structure of posttraumatic stress disorder (PTSD) as conceptualized in the recently published fifth edition of the Diagnostic and statistical manual of mental disorders (DSM-5). Design: Participants were 258 trauma-exposed Iraq/Afghanistan war veterans. Methods: A self-report measure of PTSD symptoms was administered to all participants and confirmatory factor analysis (CFA) was used to compare several different models of PTSD. Results: CFA revealed that the best-fitting model was a six-factor model in which symptoms loaded onto the factors of intrusion, avoidance, negative affect, anhedonia, dysphoric arousal, and anxious arousal. Conclusions: These findings have important implications for ongoing conceptualization of PTSD and suggest that additional modifications to the diagnostic criteria for PTSD may still be warranted to more accurately reflect the underlying structure of PTSD symptoms.     

ERICA– an instrument to measure individual and collective regulation of learning

IntroductionThis paper presents two studies that aimed at validating the Individual and Collective Regulation of Learning Scale – ERICA.ObjectiveThe scale was developed to measure learner perceptions of macro-level co-regulation strategies in conjunction with self-regulation strategies learners use.MethodStudies in two separate educational settings are presented. The first with undergraduate psychology students (n = 547) tested the factorial structure and reliability that confirmed its psychometric qualities. The second with undergraduate healthcare students (n = 191) provided for tests of convergent and discriminant validity.ResultsThe studies confirm a six-dimensional structure that stands up to tests of validity for structure, consistency and convergence.ConclusionThe scale is suitable for use in various educational contexts and environments with large cohorts to study perceptions learners have of the strategies learners use related to planning, monitoring, assessment and decision-making regulation phases.     

The Conners Parent Rating Scale: Psychometric properties in typically developing 4- to 12-year-old Belgian French-speaking children

IntroductionThe Conners Parent Rating Scale – 48 items (CPRS) is one of the most widely used behavioral scales in clinical and research settings with children.ObjectiveThe principal aim of this study was to validate the five-factor structure of the French version of the CPRS in 4- to 12-year-old Belgian French-speaking children. Secondly, a sample of children with Attention Deficit and Hyperactivity Disorder (ADHD) was assessed and their ADHD CPRS profile was examined.MethodsA total of 382 typically developing children from 4 to 12 years old were included in this study. Furthermore, 15 children (aged 6 to 12 years old) diagnosed with ADHD participated in this study.ResultsConfirmatory factor analysis shows that the CPRS presents good psychometric properties and has a factor structure similar to the original version. Furthermore, the CPRS shows high rates of sensitivity and specificity when the ADHD and control group scores are compared.ConclusionsThis study confirms the original five-factor structure of the CPRS when used with French-speaking children. Our results highlight the fact that the CPRS is a reliable measure of parental perception of their children's disruptive behaviors, and encourage the use of culturally adapted normative data for 4- to 12-year-old children.     

Toward a three-dimensional conceptualization of performance anxiety: Rationale and initial measurement development

ObjectivesAn integrated three-dimensional model of performance anxiety was constructed to offer an alternative conceptualization that may contribute to understanding of the complex anxiety–performance relationship. In particular, the adaptive potential (producing positive effects) of anxiety was acknowledged explicitly by including a regulatory dimension. This model is characterized by five subcomponents, with worry and self-focused attention representing cognitive anxiety, autonomous hyperactivity and somatic tension representing physiological anxiety, and perceived control representing the regulatory dimension of anxiety. The overview of the conceptual framework and the underlying rationale are presented.DesignAs a necessary first step towards model testing, an initial measure was developed and the factorial validity of the model was investigated.MethodConfirmatory factor analysis was used in two independent samples (N = 286, 327) in a wide context of sports performance.ResultsA 25-item measure of performance anxiety was established. Findings of CFA revealed support for a three-dimensional first-order model.ConclusionsAlthough the present model of performance anxiety was best presented as a three-dimensional first-order structure, the integrity of the conceptual framework is considered intact as such a factor structure distinctly reflects the three major processes (i.e., cognitive, physiological and regulatory) that are proposed to be activated in the anxiety dynamics from a broad cognitive perspective.     

Latent structure and measurement invariance of the Hospital Anxiety and Depression Scale in cancer outpatients

Background/ObjectiveThe aim of the present study was to compare competing psychometric models and analyze measurement invariance of the Hospital Anxiety and Depression Scale (HADS) in cancer outpatients.MethodThe sample included 3,260 cancer outpatients. Latent structure of the HADS was analyzed using confirmatory factor analysis (CFA) with robust maximum likelihood estimation (MLR). Measurement invariance was tested for age, time of response, gender, and cancer type by comparing nested multigroup CFA models with parameter restrictions.ResultsExcept for the one-factor solutions, all models showed acceptable model fit and measurement invariance. The model with the best fit was the originally proposed two-factor model with exclusion of two items. The one-factor solutions showed inacceptable model fit and were not invariant for age and gender.ConclusionsThe HADS has a robust two-factor structure in cancer outpatients. We recommend excluding item 7 and 10 when screening for anxiety and depression.     

Analysis of a displacive superlattice in nickel arsenide

Abstract

The structural analysis by convergent-beam electron diffraction is described for a weak orthorhombic superlattice observed in both mineral and synthetic samples of NiAs. The three equivalent directions for the commensurate wavevector, q = ?(a? + b?), defined a domain structure within the hexagonal subcell. Within a single domain, the symmetry around the c axis was reduced from 6mm to 2mm. The internal structure of higher-order Laue-zone reflections in diffraction patterns recorded at 100 K was used to associate a specific phonon eigenvector or condensed soft mode with the atomic displacement pattern.     

Uncovering personality structure with the Inventory of Personality Organization: An exploration of factor structure with a Portuguese sample

IntroductionThe Inventory of Personality Organization (IPO) is a self-report measure intended to assess the severity of personality disturbance according to Otto F. Kernberg's model.ObjectiveTo study factor structure and psychometric properties of the Portuguese version of IPO (IPO-Pt).MethodTwo independent samples of 586 individuals each were used for exploratory and confirmatory factor analyses. Different models were compared in terms of reliability and validity.ResultsA three-factor solution resulted, comprising dimensions labeled as Instability of Self, Instability of Others, and Psychosis. Internal consistency and temporal stability yielded acceptable to excellent results. Correlations with measures of self-concept coherence, emotion dysregulation, psychoticism, symptom severity, and personality disturbance were as expected, and sensitivity to clinical status was confirmed.ConclusionIPO-Pt shows encouraging psychometric qualities and its latent structure resonates with important aspects of Kernberg's model, previous findings, and the DSM-5 level of personality functioning scale.     

Psychometric item evaluations of the Recovery-Stress Questionnaire for athletes

ObjectivesUsing an item-based analysis, the factor structure of the Recovery-Stress Questionnaire for Athletes (RESTQ-Sport) [Kellmann, M., & Kallus, K.W. (2001). Recovery-Stress Questionnaire for Athletes: User manual. Champaign, IL: Human Kinetics] was assessed as a test of its validity. The RESTQ-Sport is a 76-item questionnaire that was developed to assess the physical and mental impact of training stress and to facilitate the formulation of strategies for the enhancement of recovery. According to [Kellmann, M., & Kallus, K.W. (2001). Recovery-Stress Questionnaire for Athletes: User manual. Champaign, IL: Human Kinetics], two factors: Recovery and Stress, comprised the 12 General subscales and seven Sport subscales of the RESTQ-Sport.MethodsA total of 585 male and female athletes who train at a Canadian national sport center were recruited to complete the RESTQ-Sport. Maximum likelihood factor analyses were performed.ResultsThe results confirmed the two-factor structure proposed by Kellmann and Kallus for the Sport-Recovery/Stress Scale but disconfirmed this structure for the General-Recovery/Stress Scale. Item analysis further disconfirmed the two-factor structure for the General Scale and failed to confirm the 19 Subscales proposed by the authors on both of the General and Sport Scales.ConclusionsThese results are interpreted to suggest that while the questionnaire should not be considered to be a diagnostic tool for under-recovery states, the RESTQ-Sport does, nonetheless, still measure general parameters of training stress which can be tracked in recovery planning.     

Mental representation and learning: The influence of practice on the development of mental representation structure in complex action

ObjectivesRecent research has elicited distinct differences in mental representations between athletes of different skill levels. Such differences suggest that the structure of mental representations changes as a function of skill level. However, research examining how such mental representation structures develop over the course of learning is lacking. In the present study, we examine the effects of practice on the development of one's mental representation of a complex action during early skill acquisition.DesignFor this purpose, we created a controllable learning situation, using a repeated-measures design with a control group. More specifically, novice golfers were randomly assigned to either a practice group (n = 12) or a control group (n = 12). Both groups were tested before and after an acquisition phase of three days as well as after a three day retention interval.MethodsMental representation structures of the putt were recorded, employing the structural dimensional analysis of mental representation (SDA-M), which provides psychometric data on the structure and grouping of action concepts in long-term memory. In addition, outcome performance of the practice group was measured, using two-dimensional error scores of the putt.ResultsFindings revealed a significant improvement in task performance, as well as functional changes in the structure of the practice group's mental representation. In contrast, no functional adaptations were evident in the mental representation of the control group.ConclusionOur findings suggest that motor skill acquisition is associated with functional adaptations of action-related knowledge in long-term memory.     

Microstructural evolution of single-walled carbon nanotubes under electron irradiation

A sample containing single-wall carbon nanotubes (SWCNTs) has been annealed at 900°C and then irradiated by high-energy electrons in an ultrahigh-vacuum transmission electron microscope. Sequential high-resolution images showed that the structures of SWCNT bundles and individual SWCNT segments first collapsed into disordered and fullerene-like carbon materials and then reorganized into graphitic particles under continuous electron irradiation. The speed of structural evolution is dependent on the flux density of the electron irradiation.     

The influence of attentional focus on the development of skill representation in a complex action

ObjectivesRecent research has indicated that performers' mental representation of a motor skill changes over the course of learning. In the present study, we sought to ascertain whether the type of instructions (instructions that emphasize either an internal or external focus of attention) influences the development of skill representation during motor learning.DesignParticipants without golf experience were recruited to practice a golf putting task over the course of three training days. Participants were randomly assigned to either an internal focus (focus on the swing of the arms; n = 10) or external focus (focus on the speed of the ball roll; n = 10) learning group. Changes in putting performance and mental representation structure were assessed over the course of learning, as well as during a follow-up retention test two days after practice.MethodsMental representation structure was measured employing the structural dimensional analysis of mental representations (SDA-M), which provided psychometric data on the structure of the mental representation in long-term memory. Additionally, the change in putting accuracy and consistency was recorded over the course of learning.ResultsFindings indicated that the external focus group performed with greater accuracy and consistency during training, and revealed a larger degree of development in their mental representation of the putting task.ConclusionsOverall, our findings suggest that facilitating the link between an action and its effect by means of an external focus is crucial for motor performance as well as the development of skill representation.     

French translation of the Flow State Scale-2: Factor structure,cross-cultural invariance,and associations with goal attainment

ObjectivesThe goal of this paper was to assess the cross-cultural invariance of the factor structure of the French and English versions of the Flow State Scale-2 (FSS-2) [Jackson, S. A., & Eklund, R. C. (2002). Assessing flow in physical activity: The Flow State Scale-2 and Dispositional Flow State Scale-2. Journal of Sport and Exercise Psychology, 24, 133–115] and to assess the relationships between athletes’ flow state and perceived goal attainment.DesignCross-sectional with self-reported questionnaires.MethodTwo samples of sport participants completed the FSS-2 immediately after an event and within a few days after the event, respectively. Data were analyzed with reliability and confirmatory factor analyses as well as with correlational and regression analyses.ResultsResults of confirmatory factor analyses on the French FSS-2 replicated the factor structure of the original FSS-2 with the first-order 9-factor and the hierarchical models both displaying adequate level of goodness-of-fit. Results of multi-sample analyses indicated that most parameters of the FSS-2 were invariant across languages. As expected, flow state correlated significantly with goal attainment during a sport competition. The relationship between flow and goal attainment was invariant across levels of competition.ConclusionsThis study provided support for the factor structure of the French version of the FSS-2 and for the invariance of the flow construct across languages. Flow state is significantly associated with goal attainment and the relationship is equivalent across athletes’ levels of competition.     

Validation française du School Burnout Inventory

IntroductionFirst studied in adults, the concept of burnout was recently extended to adolescents in order to evaluate the impact of school requirements on their health.ObjectiveThis study aim at assessing construct validity, reliability and concurrent validity of a French version of the School Burnout Inventory (Salmela-Aro, Kiuru, Leskinen, & Nurmi, 2009) that characterize school burnout by exhaustion linked to school demands, cynicism toward school and feelings of inadequacy as a student.MethodThree hundred and eighty-seven adolescents have filled the translated questionnaire and a confirmatory factor analysis was performed on the data.ResultsThe analysis confirmed the tridimensional structure of the scale and mainly show satisfactory psychometric qualities.ConclusionThis measurement scale should provide clinicians with a rapid and simple assessment of school burnout in adolescents. Researchers could also benefit from it in order to extend theoretical knowledge about this trouble.