An analytical solution to the nonlinear evolutionary equations for nucleation and growth of particles

ABSTRACT

In this paper, we consider a mathematical model for the growing crystals in supersaturated or supercooled systems. An integro-differential equation of the Fokker-Planck type is analytically solved using the saddle point method for the Laplace integral. The solution describes an intermediate stage of the phase transition process with allowance for the power law of the growth rate of spherical particles and the nucleation mechanisms known as the Meirs and Weber-Volmer-Frenkel-Zeldovich kinetics. A dynamical dependencies for the supersaturation/supercooling and the distribution function of crystals by their size are obtained. The novelty of the theory is the use of a power law for the growth rate of crystals, which leads to new analytical solutions of the problem.     

Density evolution during the growth of disc-shaped aluminium nanoparticles on a liquid surface

Aluminium (Al) nanoparticles (NPs) have been successfully fabricated on a liquid surface by thermal evaporation at room temperature. The Al NPs exhibit a disc-shaped morphology with mean diameter and height in the ranges 20–35 and 1.3–3.7?nm, respectively. As the nominal film thickness increases from 0.02 to 0.18?nm, the mean diameter and height are nearly independent of the thickness, implying that the density of the NPs increases during their growth. An explanation for this phenomenon is presented.     

Burnout during a long-term rehabilitation: comparing low burnout,high burnout – benefited,and high burnout – not benefited trajectories

Abstract

To focus rehabilitation activities among burnout clients more effectively, it is important to investigate who benefits from burnout interventions. This study (N=85) aimed at identifying burnout trajectories in terms of benefit, that is, subgroups of clients who share similar mean levels and changes in burnout during a one-year rehabilitation intervention (17 days in total) with a six-month follow-up. After identifying the burnout trajectories, the relations of the trajectories with factors describing the clients, antecedents, and consequences of burnout during the one-year intervention were examined. Three burnout trajectories were identified by growth mixture modeling: (a) low burnout (n=39), (b) high burnout – benefited (n=29), and (c) high burnout – not benefited (n=17). Positive changes were detected in antecedents and consequences among the clients in the low burnout and high burnout – benefited trajectories. Recovery from burnout was associated with increased job resources and decreased job demands, as well as with increased job satisfaction and decreased depression. It seems that more precise targeting of rehabilitation is needed since the trajectories revealed not only clients with mild symptoms, but also clients who probably received this treatment too late.     

Predicting posttraumatic growth among Hurricane Katrina survivors living with HIV: the role of self-efficacy,social support,and PTSD symptoms

Abstract

The study tested the model of adaptation after trauma by Benight and Bandura (2004) indicating that posttraumatic recovery may be predicted directly by coping self-efficacy (CSE) and indirectly by social support. These relations were investigated in the context of posttraumatic growth (PTG) among Hurricane Katrina survivors living with HIV. Additionally, it was hypothesized that among individuals with more intensive Posttraumatic Stress Disorder (PTSD) symptoms, those with strong CSE would experience the strongest PTG. Cross-sectional data were collected among 90 patients with HIV who reinitiated care at the HIV outpatient clinic. Questionnaires were administered approximately 14 months after the hurricane. Higher CSE was related to higher PTG among the survivors who suffered from more intensive PTSD symptoms. Received social support was directly related to only one index of PTG, relating to others. Furthermore, although there was a significant relationship between social support and CSE, the indirect conditional effect of received social support on PTG was not confirmed. Similar results were obtained across the indices of PTG, controlling for the level of exposure to hurricane-related trauma. Cross-sectional design and convenience character of the sample warrants replications.     

Psychological Adjustment,Coping, and Emotion Regulation as Predictors of Posttraumatic Growth

Abstract

The present study examined factors contributing to reported benefits of traumatic experiences or posttraumatic growth (PTG) in a college sample. Specifically, we examined dimensions typically associated with trauma recovery (i.e., psychological functioning, coping, emotion regulation) and features of the trauma (i.e., number and recency of traumatic events, average, and maximal distress). Participants (N= 193) completed standardized questionnaires measuring these constructs. Results indicated that active coping and subjective well-being independently contributed to PTG, but social desirability and symptom distress were independent of growth. These results were consistent with study expectations. Although not specifically predicted, maximal trauma distress also uniquely predicted PTG. Contrary to expectations, effective emotion regulation did not contribute to PTG.     

Training and Mobilizing Volunteers for Emergency Response and Long-Term Support

Abstract

This article offers guidelines for the screening, assignment, and ongoing training of volunteers for active outreach, which are based on the experience of the Israel Crisis Management Center's countrywide volunteer network. Given ongoing support, volunteers can provide the vital immediate and long-term support that is particularly important to vulnerable populations. Issues in training include: (a) responding to loss and trauma, (b) collaboration, and (c) cultural sensitivity. Ways to minimize burnout through nurturing a sense of belonging, connectedness, and meaning are discussed. The unique contribution and need for special support of volunteer trauma survivors who are models of post-traumatic growth is described.     

Are Specific Emotion Regulation Strategies Differentially Associated with Posttraumatic Growth Versus Stress?

Extremely few studies have examined emotion regulation strategies as predictors of posttraumatic growth (PTG). This study aimed to examine several specific emotion regulation strategies, along with meaning making, as predictors of PTG, as opposed to posttraumatic distress. Participants were 107 adult women who had experienced a very stressful or traumatic event within the past 3 years and completed questionnaires measuring emotion regulation, meaning making, distress, and PTG. Emotion suppression positively predicted distress, but not PTG. Meaning making positively predicted PTG and negatively predicted distress. Bootstrapped mediation models showed that emotional processing has a significant indirect effect on PTG and distress through its effect on meaning making. Results indicate that researchers should pay closer attention to emotional processes involved in etiological models of PTG. It might also be helpful to examine specific emotion regulation strategies, as these can point to ways to help people navigate recovery from trauma.     

Event Centrality,Posttraumatic Cognitions,and the Experience of Posttraumatic Growth

This study tested the extent to which negative appraisals following traumatic events and the centrality of traumatic events predicted posttraumatic growth (PTG; Tedeschi &; Calhoun, 1996 Tedeschi, R. G. and Calhoun, L. G. 1996. The posttraumatic growth inventory: Measuring the positive legacy of trauma. Journal of Traumatic Stress, 9: 76–80. [Crossref] , [Google Scholar]). Participants were 405 undergraduates at a Midwestern university who reported experiencing at least one traumatic event. Regression analyses indicated that the centrality of the event was a significant predictor for all five domains of PTG. Negative appraisals of the world were related to some domains of growth, but neither negative cognitions about the self nor self-blame was a significant predictor of any of the growth domains. Interpretation of these results is considered in light of the consistencies with Janoff-Bulman's (2004) Janoff-Bulman, R. 2004. Posttraumatic growth: Three explanatory models. Psychological Inquiry, 15: 30–34. [Crossref], [Web of Science ®] , [Google Scholar] explanatory models of development of PTG.     

Tracking job performance trajectories over time: A six-year longitudinal study

There is considerable interest in moving beyond static investigations of job performance to studying the dynamics of job performance over relatively long periods of time. In the present research, we investigated the development of job performance using a large sample of 420 employees followed over a six-year period for which yearly job performance evaluations by managers were available. Latent growth models indicated the presence of a nonlinear trajectory, with alternating phases of stability, sharp increase, and abrupt decrease. Level of education, the perception of one’s direct supervisor, and self-efficacy significantly predicted individual job performance levels observed at Wave 2. Quadratic job tenure, level of education, the perception of one’s direct supervisor, and self-efficacy were found to be significant predictors of job performance development. Findings are discussed in the light of their implications for future studies examining job performance longitudinally.     

“There's a deeper level of meaning as to what suffering's all about”: experiences of religious and spiritual growth following trauma

Some survivors of trauma report experiencing beneficial changes in self-perception, relationships, and philosophy of life, and positive changes in the realm of existential, spiritual, or religious matters. The purpose of the present study was to examine participants’ phenomenological experiences of spiritual and religious posttraumatic growth (PTG). Transcribed data from semi-structured interviews with 10 women, self-identified as Christian, who had experienced spiritual or religious growth following various trauma were analysed using Interpretative Phenomenological Analysis. Results indicated how religion provided a framework that assisted participants to incorporate life changes, and to find meaning in their suffering. The most salient themes identified in relation to religious and spiritual PTG included: process of spiritual and religious growth, strengthening of religious and spiritual beliefs, and personal and spiritual growth and healing. Participants’ trauma and associated distress prompted a process of questioning and meaning-making that facilitated deeply experienced personal and spiritual growth, and was related to intrinsic religiosity.